Landslides -- Latest Articles

2012 Recipient of the ICL Varnes Medal: Dr. Rajendra Kumar Bhandari (Landslides)

Fri, 17 May 2013 22:00:00 GMT

World Landslide Forum 3 (Landslides)

Thu, 16 May 2013 22:00:00 GMT

Probabilistic landslide hazard assessment using Copula modeling technique (Landslides)

Sat, 04 May 2013 22:00:00 GMT

Abstract A new probabilistic methodology for landslide hazard assessment in regional scale using Copula modeling technique is presented. The current probabilistic landslide hazard analyses are performed under the assumption that landslide hazard elements, such as magnitude, frequency, and location, are independent. In this paper, a general approach is proposed to consider the possible dependence among hazard elements. Part of the Seattle, WA area was selected to evaluate the competence of the presented method. A total of 357 slope failure events and their corresponding topography and geology data were included in the study to develop and test the model. Based on the results, the mean success rates of the presented model in predicting landslide occurrence are 90 % in hazardous area and 12 % in safe locations on average, while these success rates are 63 and 44 % when these hazard elements were treated as mutually independent.

Three (nearly) complete inventories of landslides triggered by the May 12, 2008 Wenchuan Mw 7.9 earthquake of China and their spatial distribution statistical analysis (Landslides)

Thu, 02 May 2013 22:00:00 GMT

Abstract The May 12, 2008 Wenchuan earthquake of China (Mw 7.9 or Ms 8.0) triggered hundreds of thousands of landslides. Mapping such a large number of landslides is a major task, considering the large size of the affected area and the availability of pre- and post-earthquake remote sensing images. This paper compares three (nearly) complete landslide inventories that were compiled from visual image interpretation. The three inventories differ in the manner in which the landslides are represented, either as polygons, centroid points, or top points. Landslides in the three inventories use one-to-one correspondence. Each of the three inventories includes a large proportion of the 197,481 landslides triggered by the earthquake. These landslides were delineated as individual solid polygons and points using visual interpretation of high-resolution aerial photographs and satellite images acquired following the earthquake and verified by selected field checking throughout a broad area of approximately 110,000 km2. These landslides cover a total area of approximately 1,160 km2. Based on the inventories of landslide polygons and landslide centroid points, two types of density maps were constructed. Correlations of landslide occurrence with seismic, geologic, and topographic parameters were analyzed using the three landslide inventories. Statistical analysis of their spatial distribution was performed using both the landslide area percentage (LAP), defined as the percentage of the area affected by the landslides and the landslide number density (LND), defined as the number of landslides per square kilometer. There are two types of LNDs: the LND-centroid (based on the centroid point of the landslide) and the LND-top (based on the top point of the landslide). We used the three indexes to determine how the occurrence of the landslides correlates with elevation, slope angle, slope aspect, slope position, slope curvature, lithology, distance from the epicenter, seismic intensity, distance from the Yingxiu-Beichuan surface fault rupture, peak ground acceleration (PGA), and coseismic surface displacements (including horizontal, vertical, and total displacements). Both the LAP and the two types of LND values were observed to have continuous positive or negative correlations with the slope angle, slope curvature, distance from the epicenter and from the Yingxiu-Beichuan surface fault rupture, seismic intensity, and coseismic surface displacement. In addition, the highest values of the LAP and LND values appear at ranges from 1,200 to 3,000 m in elevation. Moreover, the landslides have preferred orientations, dominated by the eastern, southeastern, and southern directions. In addition, the sandstone, siltstone (Z), and granitic rocks experienced more concentrated landslides. No obvious correlations were observed between the LAP and LND values and slope position. Finally, we studied the orders of eight earthquake-triggered landslide impact factor effect on landslide occurrence. Highlights The 197,481 landslides triggered by the 2008 Wenchuan earthquake were delineated. Three landslide inventories were constructed: polygon, centroid, and top point inventories. The landslides were spatially analyzed with topographic, lithology, and seismic parameters.

Formation, failure, and consequences of the Xiaolin landslide dam, triggered by extreme rainfall from Typhoon Morakot, Taiwan (Landslides)

Thu, 02 May 2013 22:00:00 GMT

Abstract An extreme rainfall event on August 9, 2009, which was close to setting a world record for 48-h accumulated rainfall, induced the Xiaolin deep-seated landslide, which was located in southwestern Taiwan and had volume of 27.6 × 106 m3, and caused the formation of a landslide dam. The landslide dam burst in a very short time, and little information remained afterward. We reconstructed the process of formation and failure of the Xiaolin landslide dam and also inferred the area of the impoundment and topographic changes. A 5 × 5-m digital elevation model, the recorded water stage of the Qishan River, and data from field investigation were used for analysis. The spectral magnitude of the seismic signals induced by the Xiaolin landslide and flooding due to failure of the landslide dam were analyzed to estimate the timing of the dam breach and the peak discharge of the subsequent flood. The Xiaolin landslide dam failure resulted from overtopping. We verified the longevity of the Xiaolin landslide dam at about 2 h relying on seismic signals and water level records. In addition, the inundated area, volume of the impoundment behind the Xiaolin landslide dam, and peak discharge of the flood were estimated at 92.3 ha, 19.5 × 106 m3, and 17 × 103 m3/s, respectively. The mean velocity of the flood-recession wave front due to the dam blockage was estimated at 28 km/h, and the peak flooding velocity after failure of the dam was estimated at 23 km/h. The Xiaolin landslide provides an invaluable opportunity for understanding the mechanism of deep-seated landslides and flooding processes following a landslide dam failure.

Delineating and defining the boundaries of an active landslide in the rainforest of Puerto Rico using a combination of airborne and terrestrial LIDAR data (Landslides)

Thu, 02 May 2013 22:00:00 GMT

Abstract Light detection and ranging (LIDAR) is a remote sensing technique that uses light, often using pulses from a laser to measure the distance to a target. Both terrestrial- and airborne-based LIDAR techniques have been frequently used to map landslides. Airborne LIDAR has the advantage of identifying large scarps of landslides covered by tree canopies and is widely applied in identifying historical and current active landslides hidden in forested areas. However, because landslides naturally have relatively small vertical surface deformation in the foot area, it is practically difficult to identify the margins of landslide foot area with the limited spatial resolution (few decimeters) of airborne LIDAR. Alternatively, ground-based LIDAR can achieve resolution of several centimeters and also has the advantages of being portable, repeatable, and less costly. Thus, ground-based LIDAR can be used to identify small deformations in landslide foot areas by differencing repeated terrestrial laser scanning surveys. This study demonstrates a method of identifying the superficial boundaries as well as the bottom boundary (sliding plane) of an active landslide in National Rainforest Park, Puerto Rico, USA, using the combination of ground-based and airborne LIDAR data. The method of combining terrestrial and airborne LIDAR data can be used to study landslides in other regions. This study also indicates that intensity and density of laser point clouds are remarkably useful in identifying superficial boundaries of landslides.

First results derived from a drop-tower testing system for granular flow in a microgravity environment (Landslides)

Sat, 20 Apr 2013 22:00:00 GMT

Abstract Because of the low-gravity on the Moon and Mars, landslides there have characteristics that are very different from those observed in a conventional gravity environment. These include highly marked dynamic characteristics, evidence of fierce movement at high speed and on a large scale. One of the key problems in extra-planetary exploration is understanding the behavior of granular material flows under the influence of low gravity. A drop-tower testing system situated in Beijing has been developed and used to investigate granular flow in a microgravity environment. A set of granular flow tests was performed in both normal and microgravity environments, during which the configurations of sand flows were captured by the monitoring system. Preliminary results provide fundamental information for the future exploration of planetary landscapes.

Application of analytical hierarchy process and least-squares method for landslide susceptibility assessment along the Zhong-Wu natural gas pipeline, China (Landslides)

Sat, 20 Apr 2013 22:00:00 GMT

Abstract As one of the major problems of geo-engineering, landslides often influence the safety of linear engineering projects that cross mountainous areas. Therefore, when selecting suitable routes for such projects, it is important to assess their susceptibility to landslides. In this paper, we used a natural gas pipeline in the northeast of the Yunnan-Guizhou Plateau of China as a case study to analyze landslide susceptibility. Based on engineering geological analogy, the analytical hierarchy process, and the least-squares method, a regional landslide susceptibility assessment model was developed and was programmed using GIS ArcEngine components under the Visual Studio.NET environment. The landslide susceptibility along the Zhong-Wu natural gas pipeline from Zhongxian County to Wuhan was assessed based on this model and classified into five levels: very safe, safe, moderate, susceptible, and very susceptible. The high accuracy and prediction capability of the model were confirmed by comparing the model results with past landslide data and performing a prediction test. The results indicated that the assessment model used in this study is reliable and can be used for landslide susceptibility assessment and route selection in other areas.

ICL/IPL activities in West Africa: landslide risk assessment and hazard mapping approach (Landslides)

Tue, 16 Apr 2013 22:00:00 GMT

Abstract The ICL/IPL Project achieved results in capacity building, investigation of landslides in West Africa and also evaluated some other slope movements in the region. These include the catastrophic rock–debris avalanche at the Cameroon–Nigeria border and the Iva Valley landslides in Enugu. During the avalanche, an estimated 100 M m3 of rock and debris was moved more than 2 km from the source of the slide at 600 m above sea level to the toe in the valley in a few minutes. The materials range from mud and soil debris to blocks of rocks up to 20 m in diameter. The grain size of moved material tended to increase upslope and closer to the head scarp though it tended to decrease again close to and at the source area. Nature and composition of the basement bedrock with foliation planes dipping in the direction of slope, dominant joint sets oriented perpendicularly to the foliation, the nature of weathered material and high relief were strong factors in the avalanche. Field studies identified 43 landslides at the Iva Valley area of Enugu state, which were shallow, short run-out movements with slip-surface depth less than 2 m. The shallow slides and the avalanche are triggered by water infiltration in slopes with high topographic gradient. The soil saturation leads to a reduction of the shear strength of the soil because of a rise in pore water pressure. These landslides are known to occur during or after intense rainfalls at the beginning or at the tail end of rainy season.

Slope stabilization in difficult conditions: the case study of a debris slide in NW Italian Alps (Landslides)

Sat, 13 Apr 2013 22:00:00 GMT

Abstract A case study of a debris slide (estimated volume of about 35,000 m3) is described in this paper. This slide occurred in April 2009 in the North Western Italian Alps (Aosta valley) and damaged the SR25 road along the Valgrisenche valley. Ground investigations started with severe safety and logistic issues being posed. Given the need to open as soon as possible the road, the design of the landslide stabilization works was carried out using a “design as you go” approach. The stabilization measures were conceived to be flexible in order to allow for changes and integration during construction, in line with the progressive refinement of the geological–geotechnical slope model being developed. Back analysis by means of the limit equilibrium method (LEM) and the finite element method (FEM) was used. Groundwater level rise following heavy rainfall and spring snow melting was found to be the main cause of the debris slide. The stabilization works were designed by using both the LEM and FEM methods. The stability conditions of the engineered slope were assessed based on the available performance monitoring data.

Assessing landslide exposure in areas with limited landslide information (Landslides)

Fri, 12 Apr 2013 22:00:00 GMT

Abstract Landslide risk assessment is often a difficult task due to the lack of temporal data on landslides and triggering events (frequency), run-out distance, landslide magnitude and vulnerability. The probability of occurrence of landslides is often very difficult to predict, as well as the expected magnitude of events, due to the limited data availability on past landslide activity. In this paper, a qualitative procedure for assessing the exposure of elements at risk is presented for an area of the Apulia region (Italy) where no temporal information on landslide occurrence is available. Given these limitations in data availability, it was not possible to produce a reliable landslide hazard map and, consequently, a risk map. The qualitative analysis was carried out using the spatial multi-criteria evaluation method in a global information system. A landslide susceptibility composite index map and four asset index maps (physical, social, economic and environmental) were generated separately through a hierarchical procedure of standardising and weighting. The four asset index maps were combined in order to obtain a qualitative weighted assets map, which, combined with the landslide susceptibility composite index map, has provided the final qualitative landslide exposure map. The resulting map represents the spatial distribution of the exposure level in the study area; this information could be used in a preliminary stage of regional planning. In order to demonstrate how such an exposure map could be used in a basic risk assessment, a quantification of the economic losses at municipal level was carried out, and the temporal probability of landslides was estimated, on the basis of the expert knowledge. Although the proposed methodology for the exposure assessment did not consider the landslide run-out and vulnerability quantification, the results obtained allow to rank the municipalities in terms of increasing exposure and risk level and, consequently, to identify the priorities for designing appropriate landslide risk mitigation plans.

Spatial quick-clay predictions using multi-criteria evaluation in SW Sweden (Landslides)

Fri, 12 Apr 2013 22:00:00 GMT

Abstract The transformation of marine and glaciomarine clay deposits into high sensitive and quick clays is largely dependent on the influence of local and regional geologic history and the resulting stratigraphy. The general conditions that facilitate quick-clay development are well known from numerous laboratory investigations during the last century, but their local and regional in-field variation is less understood. In this study, the geographic distribution of quick clay in SW Sweden is predicted using a multicriteria evaluation model that incorporates both qualitative information (established theory and expert judgment concerning the influences on both quick-clay development and the stratigraphic and geomorphologic distribution of sediment types) and observational data (maps of surficial deposits, geotechnical records and digital elevation data). This information duality cannot be avoided if knowledge from different disciplines is utilized. Considering this, model transparency is important for improvements and for characterizing its reliability for risk analysis. The model was constructed stepwise by an initial parameterization with subsequent hierarchical structuring, weighting and standardization of criteria, before running the full analysis. Comparisons between regional model results and geotechnically documented localities have yielded promising results concerning the model’s ability to predict general trends. However, the large natural and site-specific variability of clay sensitivities is not always captured by the model. These deviations are examined and suggestions are given for minimizing their effect. Applications of model methodology and results are briefly discussed.

Centrifuge model test study on pile reinforcement behavior of cohesive soil slopes under earthquake conditions (Landslides)

Fri, 12 Apr 2013 22:00:00 GMT

Abstract In this study, dynamic centrifuge model tests were conducted to investigate the dynamic response of cohesive soil slopes with the use of stabilizing piles during an earthquake. The behavior of the pile reinforcement was analyzed based on the obtained deformation over the entire slope through image-based measurement, and the behavior of the slope was compared to that of an unreinforced slope. The piles significantly increased the stability of the slope and reduced its deformation during an earthquake. The bending moment of the piles exhibited a nearly triangular distribution due to the earthquake. The acceleration response of the slope increased with increasing elevation, and the displacement accumulated apparently irreversibly over the course of the earthquake. The piles significantly affected the deformation of the slope in a certain area, the boundary of which was defined using a continuous surface. A strain analysis of the slope demonstrated that the piles had a significant effect on the reduction in the deformation of the slope in their vicinities, and this effect expanded upward along the slope and arrested the possible slip surface that would have occurred in an unreinforced slope. Several influencing factors were simulated in the tests, and observation of these factors demonstrated that the dynamic response of the pile-reinforced slope was affected by the pile spacing, pile location, slope gradient, and input earthquake to varying extent.

Improving mass-wasting inventories by incorporating debris flow topographic signatures (Landslides)

Thu, 11 Apr 2013 22:00:00 GMT

Abstract Debris flows are a prevalent and destructive mass-wasting type in many mountainous regions throughout the world, yet the recent identification of a debris flow topographic signature has not been incorporated into landslide inventories. We have detected this signature in a digital elevation model of the mountainous Oconaluftee River basin of the southern Appalachians, USA, where we have conducted mass-wasting inventories. We evaluate the applicability of this topographic signature in debris flow mapping efforts using inventories created by semiautomated classification of topographic derivative and vegetation index maps. Debris flow detection was increased by 12 % when the inventory was limited to the portion of the landscape that exhibits the debris flow topographic signature. The extent of drainages with this topographic signature, which have areas of 6 to 35 km2, is corroborated by analyses of channel form, knickpoint and bedrock distributions, and hypsometry. This mass-wasting inventory technique provides a more focused approach to statistically characterize the land surface, which resulted in increased inventory proficiency across a landscape with an extensive and relatively well-documented debris flow history.

Seasonal effects of rainfall on the shallow pyroclastic deposits of the Campania region (southern Italy) (Landslides)

Tue, 09 Apr 2013 22:00:00 GMT

Abstract The shallow deposits of unsaturated pyroclastic soils covering the slopes in the Campania region (southern Italy) are systematically affected by various rainfall-induced slope instabilities. The type and triggering of these instabilities depend on several factors, among which in situ soil suction—as an initial condition—and rainfall—as a boundary condition—play a fundamental role. Based on the available database—which includes a comprehensive catalogue of historical data, in situ soil suction measurements and soil laboratory tests along with the results of geomechanical analyses—this paper discusses the relationships among in situ soil suction and rainfall conditions and induced slope instability types. The goal is to reach a better understanding of past events and gain further insight into the analysis and forecasting of future events. In particular, the paper outlines how the season strongly affects the spatial distribution and the type of slope instability likely to develop. For example, erosion phenomena essentially occur at the end of the dry season and originate hyperconcentrated flows while first-time shallow slides prevail in the rainy season and later propagate as debris flows or as debris avalanches.

A new theoretical method for analyzing confined dry granular flows (Landslides)

Tue, 09 Apr 2013 22:00:00 GMT

Abstract A granular body may deform in a continuous fashion such that the solid particles remain in close contact. Previous research works have always used the frictional Coulomb-like continuum treatment for analyzing granular bodies. However, this approach is only applicable for quasi-static conditions and cannot capture the complicated granular contact behavior of solid particles inside a failing granular body. This paper applies a revised Savage–Hutter equation to model granular flows moving down a confined, sloping channel. The Coulomb contact friction law is modified to consider the effect of the shear rate inside a granular body. This new method also considers the confinement effect of a sloping channel on granular flow mobility. The derived depth-averaged equations of motion bear a resemblance to nonlinear shallow-water wave equations. Results computed using the derived equations are compared with measurements from flume model tests, and consistency is found between the two.

Movement of deep-seated rainfall-induced landslide at Hsiaolin Village during Typhoon Morakot (Landslides)

Tue, 09 Apr 2013 22:00:00 GMT

Effect assessment of debris flow mitigation works based on numerical simulation by using Kanako 2D (Landslides)

Tue, 09 Apr 2013 22:00:00 GMT

Abstract Mitigation works are very essential for mitigation of debris-flow hazards in mountainous areas. Usually, it is difficult to assess the effectiveness of existing mitigation works in a catchment. This paper presented a method for quantitative assessment of debris flow mitigation measures by using Kanako system, a user-friendly GUI-equipped debris flow simulator that allows good visualization and easy interpretation. Kanako 2D (Ver. 2.04) was applied to a case study at Caijia Gully, Sichuan Province, China. Mitigation works including check dams, drainage channel, and deposition basin were constructed in the gully in 2001 and 2006. Kanako 2D can simulate debris flow from steep area to alluvial fan. 1D simulation was applied for assessing the effect of the check dams at the lower part of the gully, and 2D simulation was applied for the effect of the drainage channel and deposition basin on the alluvial fan. The simulation results indicate that debris flow will cause great damage to residential area on the alluvial fan if mitigation measures were not implemented in the gully. For old dams which have been filled up with deposits of previous debris flows, the results show that they still have the function for controlling debris flow due to the gradient reduction of the channel bed in front of the dams by the trapped debris flow deposition. After the comprehensive control of debris flow including trapping, drainage, and deposition in the gully, the simulation results indicate that the risk on the alluvial fan can be reduced to an acceptable level.

The application of an innovative inverse model for understanding and predicting landslide movements (Salazie cirque landslides, Reunion Island) (Landslides)

Tue, 09 Apr 2013 22:00:00 GMT

Abstract The prediction of landslide movement acceleration is a complex problem, among others identified for deep-seated landslides, and represents a crucial step for risk assessment. Within the scope of this problem, the objective of this paper is to explore a modelling method that enables the study of landslide function and facilitates displacement predictions based on a limited data set. An inverse modelling approach is proposed for predicting the temporal evolution of landslide movement based on rainfall and displacement velocities. Initially, the hydrogeology of the studied landslides was conceptualised based on correlative analyses. Subsequently, we applied an inverse model with a Gaussian-exponential transfer function to reproduce the displacements. This method was tested on the Grand Ilet (GI) and Mare-à-Poule-d’Eau (HB) landslides on Reunion Island in the Indian Ocean. We show that the behaviour of landslides can be modelled by inverse models with a bimodal transfer function using a Gaussian-exponential impulse response. The cumulative displacements over 7 years of modelling (2 years of calibration period for GI, and 4 years for HB) were reproduced with an RMSE above 0.9. The characteristics of the bimodal transfer function are directly related to the hydrogeological functioning demonstrated by the correlative analyses: the rapid reaction of a landslide can be associated with the effect of a preferential flow path on groundwater level variations. Thus, this study shows that the inverse model using a Gaussian-exponential transfer function is a powerful tool for predicting deep-seated landslide movements and for studying how they function. Beyond modelling displacements, our approach effectively demonstrates its ability to contribute relevant data for conceptualising the sliding mechanisms and hydrogeology of landslides.

Application of expert rules in indirect approaches for landslide susceptibility assessment (Landslides)

Tue, 09 Apr 2013 22:00:00 GMT

Abstract Landslide susceptibility (LS) assessment by indirect approaches presents some limitations due to (1) the tendency to simplify the environmental factors (i.e., variables) and (2) the assumptions that landslides occur under the same combination of variables for a study site. Recently, some authors have discussed the interest to introduce expert knowledge in the indirect approaches in order to improve the quality of indirect LS maps. However, if the results are reliable, the procedures used seem fastidious and a very good knowledge of the study site is essential. The objectives of this paper are to discuss a methodology to introduce the expert knowledge in the indirect mapping process. After the definition of the expert rules associated to three landslide types, several indirect LS maps are produced by two indirect exploratory approaches, based on fuzzy set theory and on a modification of a bivariate method called expert weight of evidence. Then, the indirect LS maps are confronted to a landslide inventory and a LS map produced by a direct approach. The analyses indicate that the methodology used to introduce the expert rules in the mapping process increases the predictive power of indirect LS map. Finally, some indications about advantages and drawbacks of each approach are given to help the geoscientist to introduce his expert knowledge in the landslide susceptibility mapping process.

World Landslide Forum 3 (Landslides)

Tue, 09 Apr 2013 22:00:00 GMT

The ICL Adriatic-Balkan Network: analysis of current state and planned activities (Landslides)

Tue, 09 Apr 2013 22:00:00 GMT

Rainfall-triggered large landslides on 15 December 2005 in Van Canh District, Binh Dinh Province, Vietnam (Landslides)

Tue, 09 Apr 2013 22:00:00 GMT

Abstract Landslides are one of the most dangerous hazards in Vietnam. Most landslides occur at excavated slopes, and natural slope failures are rare in the country. However, the volume of natural slope failures can be very significant and can badly affect large areas. After a long period of heavy rainfall in the fourth quarter of 2005 in Van Canh district, a series of landslides with volumes of 20,000–195,000 m3 occurred on 15 December 2005. The travel distances for the landslides reached over 300–400 m, and the landslides caused some remarkable loud booming noises. The failures took place on natural slopes with unfavorable geological settings and slope angles of 28–31°. The rainfall in the fourth quarter of 2005 is estimated to have a return period of 100 years and was the main triggering factor. Because of the large affected area and low population density, resettling people from the dangerous landslide-prone residential areas to safer sites was the most appropriate solution. In order to do so, a map of landslide susceptibility was produced that took into account slope angle, distance to faults, and slope aspect. The map includes four levels from low to very high susceptibility to landslides.

Satellite remote sensing-based detection of the deformation of a reservoir bank slope in Laxiwa Hydropower Station, China (Landslides)

Tue, 09 Apr 2013 22:00:00 GMT

Abstract Laxiwa Hydropower Station is the largest among those hydropower stations in the upper reaches of the Yellow River. The construction started in October 2001, diversion tunnel was finished in January 2004, and impoundment started in March 2009. However, from May 2009, the right-bank slope of the reservoir about 700 m high and 1,000 m wide located 500 m far from the dam was found to be deforming greatly and continuously. Although this slope had been identified as an old landslide, the survey before the construction of the dam concluded that this slope being composed of granite is stable and would be stable even after the impoundment, and thus no detailed monitoring of the slope deformation had been performed before the visible deformation occurred after the impoundment. To indentify the relationship between the deformation of the slope and impoundment, we utilized differential synthetic aperture radar interferometry and Advanced Land Observing Satellite Prism data to analyze the slope deformation before and after impoundment. We found that no identifiable deformation took place before the impoundment, while during the period of 3 April 2009 to 22 May 2010, after impoundment, maximum horizontal displacement reached approximately 7.5 m. This slope is still deforming even after a total horizontal displacement of several tens of meters being reached, showing high risk of catastrophic failure.

Development of a new translational and rotational slides prediction model in Langhe hills (north-western Italy) and its application to the 2011 March landslide event (Landslides)

Tue, 09 Apr 2013 22:00:00 GMT

Abstract This study outlines the relationship between antecedent precipitations and activation of the translational rock-block slides (TRBSs). This type of landslide has the peculiarity to involve wide sectors of the sedimentary bedrock, and it is emblematic in the Langhe area, in the southern hilly part of Piemonte in the Tertiary Piemonte Basin. The Langhe hills are particularly renowned for the cultivation of valuable vineyards, and therefore, constitute a place of important economic and tourist interest. Furthermore, the high density of structures and infrastructures in this area exposes a number of elements to the activity of these large landslides. In order to minimize human and economic losses, it is particularly important to establish a warning system capable of providing announcement of activation of TRBSs with sufficient advance. In this direction, the Environmental Protection Agency of Piemonte (ARPA Piemonte) developed a precipitation–threshold-based model. The model is set up on an extensive collection of historical data about the landslides movements (since 1917) and the related complete meteorological dataset. The regional weather gauge network and the forecasted precipitation amount, including snow melt’s contribution, provide input data to the model. Output model can be tested by observations derived by the regional landslides monitoring network consisting of inclinometers and groundwater gauges managed by ARPA Piemonte.

Mapping landslide susceptibility with logistic regression, multiple adaptive regression splines, classification and regression trees, and maximum entropy methods: a comparative study (Landslides)

Tue, 09 Apr 2013 22:00:00 GMT

Abstract Four statistical techniques for modelling landslide susceptibility were compared: multiple logistic regression (MLR), multivariate adaptive regression splines (MARS), classification and regression trees (CART), and maximum entropy (MAXENT). According to the literature, MARS and MAXENT have never been used in landslide susceptibility modelling, and CART has been used only twice. Twenty independent variables were used as predictors, including lithology as a categorical variable. Two sets of random samples were used, for a total of 90 model replicates (with and without lithology, and with different proportions of positive and negative data). The model performance was evaluated using the area under the receiver operating characteristic curve (AUC) statistic. The main results are (a) the inclusion of lithology improves the model performance; (b) the best AUC values for single models are MLR (0.76), MARS (0.76), CART (0.77), and MAXENT (0.78); (c) a smaller amount of negative data provides better results; (d) the models with the highest prediction capability are obtained with MAXENT and CART; and (e) the combination of different models is a way to evaluate the model reliability. We further discuss some key issues in landslide modelling, including the influence of the various methods that we used, the sample size, and the random replicate procedures.

Displacement prediction in colluvial landslides, Three Gorges Reservoir, China (Landslides)

Tue, 09 Apr 2013 22:00:00 GMT

Abstract The prediction of active landslide displacement is a critical component of an early warning system and helps prevent property damage and loss of human lives. For the colluvial landslides in the Three Gorges Reservoir, the monitored displacement, precipitation, and reservoir level indicated that the characteristics of the deformations were closely related to the seasonal fluctuation of rainfall and reservoir level and that the displacement curve versus time showed a stepwise pattern. Besides the geological conditions, landslide displacement also depended on the variation in the influencing factors. Two typical colluvial landslides, the Baishuihe landslide and the Bazimen landslide, were selected for case studies. To analyze the different response components of the total displacement, the accumulated displacement was divided into a trend and a periodic component using a time series model. For the prediction of the periodic displacement, a back-propagation neural network model was adopted with selected factors including (1) the accumulated precipitation during the last 1-month period, (2) the accumulated precipitation over a 2-month period, (3) change of reservoir level during the last 1 month, (4) the average elevation of the reservoir level in the current month, and (5) the accumulated displacement increment during 1 year. The prediction of the displacement showed a periodic response in the displacement as a function of the variation of the influencing factors. The prediction model provided a good representation of the measured slide displacement behavior at the Baishuihe and the Bazimen sites, which can be adopted for displacement prediction and early warning of colluvial landslides in the Three Gorges Reservoir.

Kinematics and internal deformation of granular slopes: insights from discrete element modeling (Landslides)

Tue, 09 Apr 2013 22:00:00 GMT

Abstract The kinematics and internal deformation of a failure mass during the flow-like moving off a slope were monitored and quantified with the particle flow method in this study. Two kinds of cases were investigated, noncohesive and cohesive granular slopes. Three different internal friction angles and cohesive strengths were considered to systematically investigate their effect on the kinematics and internal deformation of the failure mass. We analyzed the movement within the failure mass and concluded that the mass moves downwards in an undulating pattern. The slope surface topography changes from a straight line to curved lines with slope breaks in a convex geometry. In addition, dilatation within the failure mass, which deforms internally and heterogeneously, is strongly dependent on its mechanical properties. A larger mass moves downslope, and the mass moves faster and further in the model with lower internal friction and cohesion. The internal friction and cohesion have a positive impact on porosity and two-dimensional (or volumetric in 3D) strain within the failure mass.

Effect of anisotropic conductivity on suction and reliability index of unsaturated slope exposed to uniform antecedent rainfall (Landslides)

Tue, 09 Apr 2013 22:00:00 GMT

Abstract The authors discuss the effect of anisotropic conductivity on the suction and reliability index of an unsaturated embankment for uniform rainfall whose intensity is lower than the saturated hydraulic conductivity. The analysis is performed on good-drainage soil of a specific horizontal conductivity and various anisotropic ratios such that the vertical conductivity is reduced. The initial suction profile for the unsaturated zone is 15 kPa. The effect of the shear strength caused by matric suction in the unsaturated zone is explained by the modified Mohr–Coulomb failure criteria. The uncoupled approach of finite element method and limit equilibrium method is used to evaluate the reliability index at different elapsed time of an antecedent rainfall. The anisotropic conductivity ratios affect the volumetric water content and the suction profile. The reliability index remains practically unchanged at high anisotropic ratios but decreases noticeably at low ratios when the wetting front reaches and elevates the water table level.

Regional landslide susceptibility zoning with considering the aggregation of landslide points and the weights of factors (Landslides)

Tue, 09 Apr 2013 22:00:00 GMT

Abstract In this paper, we propose a methodology for landslide susceptibility assessment at a regional scale in Yunnan, southwestern province of China. A landslide inventory map including 3,242 landslide points was prepared for the study area. Five factors recognized as correlated to landslide (namely, lithology, relative relief, tectonic fault density, rainfall, and road density) were analyzed and mapped in geographic information system. An index expressing the correlation between each factor and landslides [called class landslide susceptibility index (CLSI)] was proposed in the study. While analyzing landslide distribution in a large area, point aggregation might be expected. To quantify the uncertainty caused by aggregation, class landslide aggregation index was proposed. To account for the importance of each of the factors in the landslide susceptibility assessment, some weights were calculated by means of analytic hierarchy process. We propose a weighted class landslide susceptibility model (WCLSM), obtained by the combination of CLSI values of each factor with the correspondent weight. WCLSM performance in the study area was evaluated comparing the results obtained by first modeling all landslides and then by performing a time partition. The model was run including only landslides that occurred before 2009 and then validated with respect to landslides that occurred after 2009. The prediction–rate curve shows that the WCLSM model provides a good prediction for the study area. Of the study area, 21.4 % shows very high and high susceptibility and includes the 87.7 % of the number of landslides that occurred after 2009.

Landslide susceptibility mapping using GIS-based multi-criteria decision analysis, support vector machines, and logistic regression (Landslides)

Tue, 09 Apr 2013 22:00:00 GMT

Abstract Identification of landslides and production of landslide susceptibility maps are crucial steps that can help planners, local administrations, and decision makers in disaster planning. Accuracy of the landslide susceptibility maps is important for reducing the losses of life and property. Models used for landslide susceptibility mapping require a combination of various factors describing features of the terrain and meteorological conditions. Many algorithms have been developed and applied in the literature to increase the accuracy of landslide susceptibility maps. In recent years, geographic information system-based multi-criteria decision analyses (MCDA) and support vector regression (SVR) have been successfully applied in the production of landslide susceptibility maps. In this study, the MCDA and SVR methods were employed to assess the shallow landslide susceptibility of Trabzon province (NE Turkey) using lithology, slope, land cover, aspect, topographic wetness index, drainage density, slope length, elevation, and distance to road as input data. Performances of the methods were compared with that of widely used logistic regression model using ROC and success rate curves. Results showed that the MCDA and SVR outperformed the conventional logistic regression method in the mapping of shallow landslides. Therefore, multi-criteria decision method and support vector regression were employed to determine potential landslide zones in the study area.

The First Meeting of ICL Landslides in Cold Regions Network, Harbin, 2012 (Landslides)

Tue, 09 Apr 2013 22:00:00 GMT

The Cascade rock avalanche: implications of a very large Alpine Fault-triggered failure, New Zealand (Landslides)

Tue, 09 Apr 2013 22:00:00 GMT

Abstract Catastrophic deep-seated rock slope failures (RSFs; e.g., rock avalanches) can be particularly useful proxies for fault rupture and strong ground motion, and currently represent an underappreciated hazard of earthquakes in New Zealand. This study presents observations of the previously undescribed Cascade rock avalanche (CRA), a c. 0.75 km3 single-event, long-runout, catastrophic failure interpreted to have been coseismically triggered by a large to great earthquake c. 660 AD on the Alpine Fault. Despite its size and remarkable preservation, the CRA deposit has been previously identified as a terminal moraine and fault-damaged outcrop, highlighting the common misinterpretation of similar rock avalanche deposits. Comparisons are drawn between the CRA and other Alpine Fault-attributed rock avalanches, such as the better-studied c. 860 AD Round Top rock avalanche, to re-assess coseismic rock avalanche hazard. Structural relationships indicate the rock mass comprising the CRA may have formerly been a portion of a larger (c. 3 km3) RSF, before its catastrophic collapse on a deep-seated gravitational collapse structure (sackung). Sackungen and RSFs are common throughout the Southern Alps and other mountainous regions worldwide; in many cases, they should be considered potential precursors to catastrophic failure events. Two masses of rock in the Cascade River Valley show precursory signs of potential catastrophic failures of up to c. 2 km3; a similar mass may threaten the town of Franz Josef.

The First Meeting of ICL Landslides in Cold Regions Network, Harbin, 2012 (Landslides)

Fri, 30 Nov 2012 23:00:00 GMT

Abstract The First Meeting of ICL Landslides in Cold Regions Network and First Symposium on Landslides in Cold Regions were held in Harbin, China on 23–27 July 2012. The main goal of the network is to promote cooperation of scientists studying landslides in the permafrost regions and regions with extreme weather conditions. It will support joint comprehensive investigations carried out by geographers, geologists, geocryologists, and meteorologists from different countries and regions, landslide mechanisms study, distinguishing of landforms, provision of landslide hazard assessment, and elaboration of early warning systems. Such cooperation will enhance our understanding of hazardous phenomena in cold regions and the safety of people living there, their property, and infrastructure. This meeting included an international symposium “Landslide in Cold Regions,” 2-day field trip, discussion, and approval of the “Constitution of ICL Landslides in Cold Regions Network,” “2012–2016 Action Plan of ICL Landslides in Cold Regions Network,” and “Declaration of the First Meeting of ICL Landslides in Cold Regions Network.” Content Type Journal Article Category ICL/IPL Activities Pages 1-4 DOI 10.1007/s10346-012-0369-x Authors Ying Guo, Northeast Forestry University, No. 26, Hexing Road, Harbin, 150040 China Paolo Canuti, ICL & University of Firenze, Via La Pira, 4 Firenze, 50121 Italy Alexander Strom, Geodynamic Research Center - branch of JSC “Hydroproject Institute”, Volokolamskoe Shosse 2, Moscow, 125993 Russia Marui Hideaki, Research Institute for Natural Hazards and Disaster Recovery, Niigata University, 8050 Ikarashi-Ninocho, nishi-ku, Niigata, 950-2181 Japan Wei Shan, Northeast Forestry University, No. 26, Hexing Road, Harbin, 150040 China Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

Hummocks: how they form and how they evolve in rockslide-debris avalanches (Landslides)

Sun, 18 Nov 2012 23:00:00 GMT

Abstract Hummocks are topographic features of large landslides and rockslide-debris avalanches common in volcanic settings. We use scaled analog models to study hummock formation and explore their importance in understanding landslide kinematics and dynamics. The models are designed to replicate large-scale volcanic collapses but are relevant also to non-volcanic settings. We characterize hummocks in terms of their evolution, spatial distribution, and internal structure from slide initiation to final arrest. Hummocks initially form by extensional faulting as a landslide begins to move. During motion, individual large blocks develop and spread, creating an initial distribution, with small hummocks at the landslide front and larger ones at the back. As the mass spreads, hummocks can get wider but may decrease in height, break up, or merge to form bigger and long anticlinal hummocks when confined. Hummock size depends on their position in the initial mass, modified by subsequent breakup or coalescence. A hummock has normal faults that flatten into low-angle detachments and merge with a basal shear zone. In areas of transverse movement within a landslide, elongate hummocks develop between strike–slip flower structures. All the model structures are consistent with field observations and suggest a general brittle-slide emplacement for most landslide avalanches. Absence of hummocks and fault-like features in the deposit may imply a more fluidal flow of emplacement or very low cohesion of lithologies. Hummocks can be used as kinematic indicators to indicate landslide evolution and reconstruct initial failures and provide a framework with which to study emplacement dynamics. Content Type Journal Article Category Original Paper Pages 1-14 DOI 10.1007/s10346-012-0368-y Authors E. M. R. Paguican, Laboratoire Magmas et Volcans, Université Blaise Pascal, Clermont Université, 5 rue Kessler, 63038, BP 10448, 63000 Clermont-Ferrand, France B. van Wyk de Vries, Laboratoire Magmas et Volcans, Université Blaise Pascal, Clermont Université, 5 rue Kessler, 63038, BP 10448, 63000 Clermont-Ferrand, France A. M. F. Lagmay, National Institute of Geological Sciences, College of Science, University of the Philippines, Diliman, Quezon, 1101 Philippines Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

Debris-flow simulations on Cheekye River, British Columbia (Landslides)

Tue, 13 Nov 2012 23:00:00 GMT

Abstract Cheekye River fan is the best-studied fan complex in Canada. The desire to develop portions of the fan with urban housing triggered a series of studies to estimate debris-flow risk to future residents. A recent study (Jakob and Friele 2010) provided debris-flow frequency-volume and frequency-discharge data, spanning 20-year to 10,000-year return periods that form the basis for modeling of debris flows on Cheekye River. The numerical computer model FLO-2D was chosen as a modelling tool to predict likely flow paths and to estimate debris-flow intensities for a spectrum of debris-flow return periods. The model is calibrated with the so-called Garbage Dump debris flow that occurred some 900 years ago. Field evidence suggests that the Garbage Dump debris flow has a viscous flow phase that deposited a steep-sided debris plug high in organics in centre fan, which then deflected a low-viscosity afterflow that travelled to Squamish River with slowly diminishing flow depths. The realization of a two-phase flow led to a modelling approach in which the debris-flow hydrograph was split into a high viscosity and low viscosity phase that were modelled in chronologic sequence as two separate and independent modelling runs. A perfect simulation of the Garbage Dump debris flow with modelling is not possible because the exact topography at the time of the event is, to some degree, speculative. However, runout distance, debris deposition and deposit thickness are well known and serve as a good basis for calibration. Predictive analyses using the calibrated model parameters suggest that, under existing conditions, debris flows exceeding a 50-year return period are likely to avulse onto the southern fan sector, thereby damaging existing development and infrastructure. Debris flows of several thousand years return period would inundate large portions of the fan, sever Highway 99, CN Rail, and the Squamish Valley road and would impact existing housing development on the fan. These observations suggest a need for debris-flow mitigation for existing and future development alike. Content Type Journal Article Category Original Paper Pages 1-15 DOI 10.1007/s10346-012-0365-1 Authors Matthias Jakob, Matthias Jakob, BGC Engineering Inc., 1045 Howe Street, Vancouver, BC, Canada Scott McDougall, Matthias Jakob, BGC Engineering Inc., 1045 Howe Street, Vancouver, BC, Canada Hamish Weatherly, Matthias Jakob, BGC Engineering Inc., 1045 Howe Street, Vancouver, BC, Canada Neil Ripley, Matthias Jakob, BGC Engineering Inc., 1045 Howe Street, Vancouver, BC, Canada Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

Application of infrared thermography for mapping open fractures in deep-seated rockslides and unstable cliffs (Landslides)

Fri, 09 Nov 2012 23:00:00 GMT

Abstract We present a new approach for mapping open cracks and tension fractures within rock slope instabilities and rock cliffs, which resides in high-resolution ground-based and airborne infrared thermography (IRT). The method is restricted to cold seasons, and its utility is demonstrated through three examples from the Flysch Belt of the Outer West Carpathians (rockslides at Kopce Hill and Mt. Kněhyně) and from the Northern Calcareous Alps (deep-seated gravitational slope deformations in Gschliefgraben/Mt. Traunstein). The approach is based on a contrast between temperatures deep within the rock mass, which at a depth of few meters represent local mean annual values, and winter-time temperatures of the ground surface. In winter, warmer, buoyant air from depth rises to the ground surface through open cracks and joints, and the temperature contrast can be detected by IRT. Our test survey was conducted in the beginning of February 2012, in order to achieve the best contrast between temperatures around open tension cracks and the adjacent ground. For temperature sensing, we used a FLIR B360 thermal camera; for airborne surveys in the ambient air, temperatures at the time of our surveys ranged from approximately −19 to −7 °C. IRT results conclusively revealed the presence of open cracks, loosened rock zones, and pseudo-karst caves over a distance sometimes greater than 1 km. The IRT approach proved useful for rapidly assessing the distribution of open cracks and tension fractures, key information required for assessing rockfall and rockslide hazard. Content Type Journal Article Category Original Paper Pages 1-13 DOI 10.1007/s10346-012-0367-z Authors Ivo Baroň, Geological Survey of Austria, Neulinggasse 38, 1030 Vienna, Austria David Bečkovský, Centre AdMaS, Faculty of Civil Engineering, Technical University Brno, Veveří 95, 602 00 Brno, Czech Republic Lumír Míča, Centre AdMaS, Faculty of Civil Engineering, Technical University Brno, Veveří 95, 602 00 Brno, Czech Republic Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

Inception of debris avalanches: remarks on geomechanical modelling (Landslides)

Fri, 09 Nov 2012 23:00:00 GMT

Abstract Debris avalanches are complex phenomena due to the variety of mechanisms that control the failure stage and the avalanche formation. Regarding these issues, in the literature, either field evidence or qualitative interpretations can be found while few experimental laboratory tests and rare examples of geomechanical modelling are available for technical and/or scientific purposes. As a contribution to the topic, the paper firstly highlights as the problem can be analysed referring to a unique mathematical framework from which different modelling approaches can be derived based on limit equilibrium method (LEM), finite element method (FEM), or smooth particle hydrodynamics (SPH). Potentialities and limitations of these approaches are then tested for a large study area where huge debris avalanches affected shallow deposits of pyroclastic soils (Sarno-Quindici, Southern Italy). The numerical results show that LEM as well as uncoupled and coupled stress–strain FEM analyses are able to individuate the major triggering mechanisms. On the other hand, coupled SPH analyses outline the relevance of erosion phenomena, which can modify the kinematic features of debris avalanches in their source areas, i.e. velocity, propagation patterns and later spreading of the unstable mass. As a whole, the obtained results encourage the application of the introduced approaches to further analyse real cases in order to enhance the current capability to forecast the inception of these dangerous phenomena. Content Type Journal Article Category Original Paper Pages 1-11 DOI 10.1007/s10346-012-0366-0 Authors L. Cascini, University of Salerno, Salerno, Italy S. Cuomo, University of Salerno, Salerno, Italy M. Pastor, Universidad Politecnica de Madrid, Madrid, Spain Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

The ICL Adriatic-Balkan Network: analysis of current state and planned activities (Landslides)

Mon, 29 Oct 2012 23:00:00 GMT

Abstract International Consortium on Landslides (ICL) Adriatic-Balkan Network was established in January 2012 as one of eight regional and thematic ICL networks to promote activities of the International Consortium on Landslides and the International Programme on Landslides. This paper presents the annual report of the ICL Adriatic-Balkan Network for the year 2012. The main activity of the regional network was to complete an overview of publicly available data and sources about landslides in the region, scientific and professional practices related to evaluation and mitigation of landslide hazard, as well as related legislative framework. Recommendations for the discussion and endorsement in the course of the ICL Adriatic-Balkan Network activities will be derived from the analysis of strengths, weaknesses, opportunities, and threats related to landslide issues which are present at the national level in Croatia, Slovenia, and Serbia and at the regional level. Discussion and endorsement of the recommendations are planned as a further activity which will be held in March 2013 in Zagreb (Croatia), during the planned first regional symposium on landslides in the Adriatic-Balkan Region. Content Type Journal Article Category ICL/IPL Activities Pages 1-7 DOI 10.1007/s10346-012-0364-2 Authors Snježana Mihalić Arbanas, Faculty of Mining, Geology and Petroleum Engineering, University of Zagreb, Pierottijeva 6, Zagreb, Croatia Željko Arbanas, Faculty of Civil Engineering, University of Rijeka, Radmile Matejčić 3, Rijeka, Croatia Biljana Abolmasov, Faculty of Mining and Geology, University of Belgrade, Đušina 7, Belgrade, Serbia Matjaž Mikoš, Faculty of Civil and Geodetic Engineering, University of Ljubljana, Jamova c. 2, Ljubljana, Slovenia Marko Komac, Geological Survey of Slovenia, Dimičeva 14, Ljubljana, Slovenia Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

Geomechanical interpretation of the Downie Slide considering field data and three-dimensional numerical modelling (Landslides)

Sun, 28 Oct 2012 23:00:00 GMT

Abstract Downie Slide has been interpreted as a massive, composite rockslide, and a number of landslide zones have been defined based on the interpretation of morphological features and a detailed assessment of spatially discriminated slope behaviour. Key factors controlling the mechanics of massive slow-moving landslides can be interpreted through the observation and detailed study of the slope behaviour and physical characteristics. Once identified, key components influencing slope deformation can be tested using three-dimensional numerical models. Two series of numerical simulations have been developed to test how explicitly defined internal shear zones, and the interaction between landslide morphological regions, influence global landslide behaviour. Results from these numerical simulations, when compared to field monitoring data, indicate that internal shear zones have little influence on Downie Slide deformation, while the interaction between morphological zones plays a larger role in slope kinematics. Content Type Journal Article Category Original Paper Pages 1-20 DOI 10.1007/s10346-012-0363-3 Authors K. S. Kalenchuk, Department of Geological Sciences and Geological Engineering, Queen’s University, Kingston, Ontario, Canada D. J. Hutchinson, Department of Geological Sciences and Geological Engineering, Queen’s University, Kingston, Ontario, Canada M. S. Diederichs, Department of Geological Sciences and Geological Engineering, Queen’s University, Kingston, Ontario, Canada Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

Advanced seismic slope stability analysis (Landslides)

Sun, 21 Oct 2012 22:00:00 GMT

Abstract The objective of this study was to present an advanced methodology for assessing seismic slope stability by taking into account the uncertainties related to the main input parameters. The methodology was applied on a real landslide in order to show the advantages of using the proposed procedure and establish the baseline trends of dynamic response and calculated permanent seismic displacements. It involves the following steps: preliminary analysis, probabilistic static and seismic factor of safety analysis, and permanent seismic displacement analysis. Estimating post-failure maximum seismic deformation of landslide mass and sounding properties is the most important part of this study. It involves both Newmark sliding block method and continuum mechanics approach, applied for characteristic set of input values in order to have more accurate assessment of slope performance and determine the relative importance of input parameters. The results of the analysis showed the benefits of using the proposed step-by-step methodology. The obtained difference in the results between the two methods depends strongly on the set input data for a particular analysis. Content Type Journal Article Category Original Paper Pages 1-8 DOI 10.1007/s10346-012-0360-6 Authors Mihail Garevski, Institute of Earthquake Engineering and Engineering Seismology, IZIIS, University “Ss. Cyril and Methodius”, 73, Salvador Aljende Str., P.O. Box 101, 1000 Skopje, Macedonia Zeljko Zugic, Institute of Earthquake Engineering and Engineering Seismology, IZIIS, University “Ss. Cyril and Methodius”, 73, Salvador Aljende Str., P.O. Box 101, 1000 Skopje, Macedonia Vlatko Sesov, Institute of Earthquake Engineering and Engineering Seismology, IZIIS, University “Ss. Cyril and Methodius”, 73, Salvador Aljende Str., P.O. Box 101, 1000 Skopje, Macedonia Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

Evaluation of the consistency of landslide susceptibility mapping: a case study from the Kankai watershed in east Nepal (Landslides)

Fri, 19 Oct 2012 22:00:00 GMT

Abstract GIS-based landslide susceptibility maps for the Kankai watershed in east Nepal are developed using the frequency ratio method and the multiple linear regression technique. The maps are derived from comparing observed landslides with possible causative factors: slope angle, slope aspect, slope curvature, relative relief, distance from drainage, land use, geology, distance from faults and mean annual rainfall. The consistency of the maps is evaluated using landslide density analysis, success rate analysis and spatially agreed area approach. The first two analyses produce almost identical quantitative results, whereas the last approach is able to reveal spatial differences between the maps and also to improve predictions in the agreed high landslide-susceptible area. Content Type Journal Article Category Original Paper Pages 1-15 DOI 10.1007/s10346-012-0361-5 Authors Prabin Kayastha, Department of Hydrology and Hydraulic Engineering, Vrije Universiteit Brussel, 1050 Brussels, Belgium Megh Raj Dhital, Mountain Risk Engineering Unit, Tribhuvan University, Kirtipur, Kathmandu, Nepal Florimond De Smedt, Department of Hydrology and Hydraulic Engineering, Vrije Universiteit Brussel, 1050 Brussels, Belgium Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

Rainfall-triggered large landslides on 15 December 2005 in Van Canh District, Binh Dinh Province, Vietnam (Landslides)

Fri, 19 Oct 2012 22:00:00 GMT

The ICL landslide monitoring and warning thematic network (Landslides)

Sat, 06 Oct 2012 22:00:00 GMT

Abstract The International Consortium on Landslides (ICL) was established in 2002 and soon became an important world player in the field of landslide risk mitigation; in 2012, it has more than 50 member organizations throughout the world. As a part of the activities to celebrate ICL’s tenth anniversary, a strategic document for the second decade called the ICL Strategic Plan 2012–2021 with the motto “to create a safer geo-environment” was adopted in Kyoto in January 2012. An important part of this document was a clear dedication to broaden the scope and societal impact in a thematic, institutional, and geographic manner. Thus, thematic and regional networks for landslide risk reduction were recognized to be an important form of ICL activities in the decade to come. In this paper, one of the eight newly established thematic and regional ICL networks is presented: the ICL Landslide Monitoring and Warning Thematic Network, a joint effort of ten ICL member organizations and two ICL supporters from eight countries, five of them are active ICL World Centres of Excellence in Landslide Risk Reduction in the period 2011–2014. The general objective of this thematic network is to compare experiences in the field of landslide monitoring and existing/installed (early) warning systems for active landslides in different regions of the world. Content Type Journal Article Category ICL/IPL Activities Pages 1-5 DOI 10.1007/s10346-012-0359-z Authors Matjaž Mikoš, Faculty of Civil and Geodetic Engineering, University of Ljubljana, Jamova cesta 2, 1000 Ljubljana, Slovenia Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

A hypothesis of the Senoumi submarine megaslide in Suruga Bay in Japan—based on the undrained dynamic-loading ring shear tests and computer simulation (Landslides)

Mon, 17 Sep 2012 22:00:00 GMT

Abstract The distinctive bathymetric feature exists in the Suruga Bay, Japan. It has been called as Senoumi (Stone flower sea) from old times. Senoumi is a 30 km wide and 20 km long concave feature. Its origin has not been explained yet; however, the feature might be a combined consequence of intensive tectonic activity in the plate border, landslides, and a submarine flow coming from the Oi River. If the Senoumi was caused by a landslide, the latter would be larger than any on-land landslide in Japan. The downshelf “exit” from this feature is much narrower than its central part. This is not usual shape of landslides, but it is similar to the liquefied landslides such as those in quick clays which mobilize great strength reduction after failure. To study Senoumi as a landslide, the shear behaviors of the following three soil samples were investigated by the cyclic and seismic undrained stress control ring shear tests. One sample is volcanic ash taken from the base of landslide deposits (mass transport deposits), from 130 to 190 m deep layer below the submarine floor which was drilled and cored by the Integrated Ocean Drilling Program Expedition 333. Another two samples are the Neogene silty–sand and silt taken from the Omaezaki hill adjacent to the Senoumi, because the shear zone might have been formed in Neogene layers extending from on-land to the continental shelf. The largest strength reduction from peak to steady-state shear resistance in the undrained cyclic loading test was found in volcanic ash. The strength reduction in Neogene silty–sand was smaller than volcanic ash, while the Neogene silt mobilized the least post-failure strength reduction. An integrated model simulating the initiation and motion of earthquake-induced rapid landslides (landslide simulation (LS)-RAPID, Sassa et al. Landslides 7–3:219–236, 2010) was applied to this study. The steady-state shear resistance and other geotechnical parameters measured by the undrained ring shear tests and the greatest strong motion record in the 2011 off-the-Pacific Coast of Tohoku earthquake (M w 9.0), also known as “2011 Tohoku Earthquake” at the observation point MYG004 (2,933 gal) were input to this model. As the result, it was found that landslides would be triggered by 0.30–1.0 times of MYG004 in volcanic ash, 0.4–1.0 times of MYG004 in Neogene silty–sand and Neogene silt, though the depth and area of triggered landslides were different in soils and intensity of shaking. Feature, created by LS-RAPID using the parameters of volcanic ash, was most similar to the Senoumi in depth and extent. The result obtained from this study includes a hypothesis to be proved, but presents the strong need to investigate the risk of the large-scale submarine landslides which could enhance tsunami wave and possibly enlarge the submarine landslide retrogressively into the adjacent coastal plain by the upcoming mega earthquake in the Nankai Trough. Content Type Journal Article Category Original Paper Pages 1-17 DOI 10.1007/s10346-012-0356-2 Authors K. Sassa, International Consortium on Landslides, Uji, Japan B. He, Disaster Prevention Research Institute, Kyoto University, Uji, Japan T. Miyagi, Tohoku Gakuin University, Sendai, Japan M. Strasser, Geological Institute of ETH Zurich, Zurich, Switzerland K. Konagai, Institute of Industrial Science, The University of Tokyo, Tokyo, Japan M. Ostric, Disaster Prevention Research Institute, Kyoto University, Uji, Japan H. Setiawan, Disaster Prevention Research Institute, Kyoto University, Uji, Japan K. Takara, Disaster Prevention Research Institute, Kyoto University, Uji, Japan O. Nagai, International Consortium on Landslides, Uji, Japan Y. Yamashiki, Disaster Prevention Research Institute, Kyoto University, Uji, Japan S. Tutumi, Shizuoka, Japan Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

Comparison of debris-flow volumes from burned and unburned areas (Landslides)

Wed, 12 Sep 2012 22:00:00 GMT

Abstract The goals of this work are to show the range of debris-flow volumes and watershed characteristics for several locations, and the differences in flow volumes for events triggered soon after wildfire. A dataset of 929 events was divided into groups based on location and burn status. The three unburned locations show significant differences: debris flows from the Italian Alps are larger and generate more debris per unit basin area or unit channel length than flows in the Western USA or in the Pacific Northwest. However, some of the observed differences may be attributed to the skew of the Italian Alps dataset towards larger events, and the small size and limited range of the Pacific Northwest data. For burned watersheds in the Western U.S. events, there is a clear progression in decreasing volume in debris flows as basins recover from the wildfire: it takes approximately 1 year, or at a few locations, as much as 3 years, for debris production to return to pre-fire rates. The difference is most apparent when the data are normalized for basin area (the area yield, which is 2× larger for burned basins) or for channel length (the length yield, which is 1.6× larger for burned basins). When normalized simultaneously for basin area, channel length, and channel gradient, burned areas produce significantly more debris (2.7–5.4 times as much). Burned areas in the Western USA are more sensitive to wildfire and produce larger debris flows than burned areas in more humid climates such as the Pacific Northwest. Content Type Journal Article Category Original Paper Pages 1-13 DOI 10.1007/s10346-012-0354-4 Authors Paul M. Santi, Department of Geology and Geological Engineering, Colorado School of Mines, 1500 Illinois Street, Golden, CO 80401, USA Luca Morandi, Department of Geology and Geological Engineering, Colorado School of Mines, 1500 Illinois Street, Golden, CO 80401, USA Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

A recent, retrogressive, complex earthflow–earth slide at Cenes de la Vega, southern Spain (Landslides)

Mon, 10 Sep 2012 22:00:00 GMT

Abstract An earthflow near Cenes de la Vega (southern Spain) was first observed after a heavy rain in January 2010 in an area where a spring had existed. Initially, the landslide affected only the lower part of the slope. Displaced materials accumulated over terraces and the river course, damming it. A year later, a new rainy period reactivated (or increased the activity of) the instability. It progressed in two ways: by sliding and involving progressively higher parts of the slope with the head scarp approaching the top of the slope, and by widening in the central part of the body. Near the top of the slope, there is a pipeline that supplies water to the city of Granada. The most probable triggering factor of the landslide seems to be a combination of persistent water leakage from the pipe, which has saturated the materials, and intense rainfall. Content Type Journal Article Category Recent Landslides Pages 1-7 DOI 10.1007/s10346-012-0358-0 Authors Jesús Garrido, Departamento de Ingeniería Civil, Universidad de Granada, Campus de Fuentenueva s/n, 18071 Granada, Spain José Delgado, Departamento de Ciencias de la Tierra, Universidad de Alicante, P.O. Box 99, Alicante, 03080 Spain Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

Deterministic estimation of hydrological thresholds for shallow landslide initiation and slope stability models: case study from the Somma-Vesuvius area of southern Italy (Landslides)

Sun, 02 Sep 2012 22:00:00 GMT

Abstract Rainfall-induced debris flows involving ash-fall pyroclastic deposits that cover steep mountain slopes surrounding the Somma-Vesuvius volcano are natural events and a source of risk for urban settlements located at footslopes in the area. This paper describes experimental methods and modelling results of shallow landslides that occurred on 5–6 May 1998 in selected areas of the Sarno Mountain Range. Stratigraphical surveys carried out in initiation areas show that ash-fall pyroclastic deposits are discontinuously distributed along slopes, with total thicknesses that vary from a maximum value on slopes inclined less than 30° to near zero thickness on slopes inclined greater than 50°. This distribution of cover thickness influences the stratigraphical setting and leads to downward thinning and the pinching out of pyroclastic horizons. Three engineering geological settings were identified, in which most of the initial landslides that triggered debris flows occurred in May 1998 can be classified as (1) knickpoints, characterised by a downward progressive thinning of the pyroclastic mantle; (2) rocky scarps that abruptly interrupt the pyroclastic mantle; and (3) road cuts in the pyroclastic mantle that occur in a critical range of slope angle. Detailed topographic and stratigraphical surveys coupled with field and laboratory tests were conducted to define geometric, hydraulic and mechanical features of pyroclastic soil horizons in the source areas and to carry out hydrological numerical modelling of hillslopes under different rainfall conditions. The slope stability for three representative cases was calculated considering the real sliding surface of the initial landslides and the pore pressures during the infiltration process. The hydrological modelling of hillslopes demonstrated localised increase of pore pressure, up to saturation, where pyroclastic horizons with higher hydraulic conductivity pinch out and the thickness of pyroclastic mantle reduces or is interrupted. These results lead to the identification of a comprehensive hydrogeomorphological model of susceptibility to initial landslides that links morphological, stratigraphical and hydrological conditions. The calculation of intensities and durations of rainfall necessary for slope instability allowed the identification of deterministic hydrological thresholds that account for uncertainty in properties and observed rainfall intensities. Content Type Journal Article Category Original Paper Pages 1-16 DOI 10.1007/s10346-012-0348-2 Authors P. De Vita, University of Naples “Federico II”, Naples, Italy E. Napolitano, University of Naples “Federico II”, Naples, Italy J. W. Godt, U.S. Geological Survey, Denver, CO 80225, USA R. L. Baum, U.S. Geological Survey, Denver, CO 80225, USA Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

GIS-based statistical analysis of the spatial distribution of earthquake-induced landslides in the island of Lefkada, Ionian Islands, Greece (Landslides)

Sun, 02 Sep 2012 22:00:00 GMT

Abstract This is the first landslide inventory map in the island of Lefkada integrating satellite imagery and reports from field surveys. In particular, satellite imagery acquired before and after the 2003 earthquake were collected and interpreted with the results of the field survey that took place 1 week after this strong (Mw = 6.3) event. The developed inventory map indicates that the density of landslides decreases from west to east. Furthermore, the spatial distribution of landslides was statistically analyzed in relation to the geology and topography for investigating their influence to landsliding. This was accomplished by overlaying these causal factors as thematic layers with landslide distribution data. Afterwards, weight values of each factor were calculated using the landslide index method and a landslide susceptibility map was developed. The susceptibility map indicates that the highest susceptibility class accounts for 38 % of the total landslide activity, while the three highest classes that cover the 10 % of the surface area, accounting for almost the 85 % of the active landslides. Our model was validated by applying the approaches of success and prediction rate to the dataset of landslides that was previously divided into two groups based on temporal criteria, estimation and validation group. The outcome of the validation dataset was that the highest susceptibility class concentrates 18 % of the total landslide activity. However, taking into account the frequency of landslides within the three highest susceptibility classes, more than 85 %, the model is characterized as reliable for a regional assessment of earthquake-induced landslides hazard. Content Type Journal Article Category Original Paper Pages 1-13 DOI 10.1007/s10346-012-0357-1 Authors George Papathanassiou, Department of Geology, Aristotle University of Thessaloniki, Thessaloniki, Greece Sotiris Valkaniotis, Department of Geology, Aristotle University of Thessaloniki, Thessaloniki, Greece Athanassios Ganas, Institute of Geodynamics, National Observatory of Athens, Athens, Greece Spyros Pavlides, Department of Geology, Aristotle University of Thessaloniki, Thessaloniki, Greece Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

Precursors and triggers of an alpine rockslide in Japan: the 2004 partial collapse during a snow-melting period (Landslides)

Sun, 02 Sep 2012 22:00:00 GMT

Abstract The Aresawa rockslide in the Japanese Alps encountered a deep, partial collapse during an early snow-melting period in May 2004, followed by further progressive movement of the headscarp area. This paper reconstructs the pre-failure topography of the Aresawa rockslide based on the analysis of aerial photographs taken in multiple periods, and analyzes the factors controlling the threshold for the 2004 collapse. At least seven months before the collapse, new tension cracks emerged about 25 m behind the headscarp as a result of downslope movement of an unstable rock slab 5–10 × 105 m3 in volume, accompanied by the development of a slip plane below a pre-existing shallow trough (sackung feature). The collapse finally occurred when progressive weakening of the rock mass was combined with water infiltration into the ground during rapid snow melting. Content Type Journal Article Category Recent Landslides Pages 1-8 DOI 10.1007/s10346-012-0353-5 Authors Ryoko Nishii, Faculty of Life and Environmental Sciences (Ikawa University Forest), University of Tsukuba, Shizuoka, Japan Norikazu Matsuoka, University of Tsukuba, Ibaraki, Japan Hiromu Daimaru, Forestry and Forest Products Research Institute, Ibaraki, Japan Masatsugu Yasuda, Chiba University, Chiba, Japan Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

A deep, stratigraphically and structurally controlled landslide: the case of Mount La Civita (Molise, Italy) (Landslides)

Sun, 02 Sep 2012 22:00:00 GMT

Abstract The present paper illustrates the results of an integrated study of a large landslide located on the southern slope of Mount la Civita (Molise, Southern Apennine), an E–W elongated, SSE dipping and 890-m-high monocline carbonate ridge. The upper part of the slope affected by the landslide is largely controlled by strata attitude while its basal part is marked by a strike–slip fault causing the tectonic juxtaposition of the carbonate successions against predominantly clayey flysch units. An integrated study, including geological, geomorphological and geotechnical investigations, was carried out to determine the features of the landslide and to plan further investigation and monitoring. In particular, from 2002 to 2004, Differential Global Positioning System monitoring and core drillings, coupled with inclinometer measurements, were carried out to determine the landslide’s kinematics, extent, depth to the surface of rupture and rates of movement. Inclinometer data revealed the presence of the rupture surface at a depth of about 20 m. DGPS monitoring allowed rates of movement up to several tens of centimetres per year to be recorded. The nearby village of Civitanova del Sannio can still be considered at risk due to the landslide, as recent remedial works, consisting mainly of very shallow re-shaping of the slope by blasting and partial filling of trenches, did not succeed in stopping its movement. Content Type Journal Article Category Original Paper Pages 1-12 DOI 10.1007/s10346-012-0351-7 Authors Pietro P. C. Aucelli, Department of Sciences for the Environment, University of Naples Parthenope, Centro Direzionale C/4, 80143 Naples, Italy Emilio Casciello, Institute of Earth Sciences “Jaume Almera”, Consejo Superior de Investigaciones Cientificas - CSIC, Barcelona, Spain Massimo Cesarano, Department of Biosciences and Territory, University of Molise, C.da Fonte Lappone, 86090 Pesche (IS), Italy Sebastiano Perriello Zampelli, Department of Architectural and Environmental Design, University of Naples Federico II, via Forno Vecchio 36, 80134 Naples, Italy Carmen M. Rosskopf, Department of Biosciences and Territory, University of Molise, C.da Fonte Lappone, 86090 Pesche (IS), Italy Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

Numerical runout simulation of debris avalanches in the Faroe Islands, North Atlantic Ocean (Landslides)

Sun, 02 Sep 2012 22:00:00 GMT

Abstract The Faroe Islands in the North Atlantic Ocean are susceptible to flow-type landslides in coarse-grained highly organic colluvium. Following several hazardous debris avalanche events, research work has been initiated to quantify landslide risk. A central task in this work is to predict landslide runout behavior. From numerical simulation of four debris avalanches, this study provides a first screening of which rheology and appertaining input parameters best predict runout behavior of debris avalanches in the Faroe Islands. Three rheologies (frictional, Voellmy, and Bingham) are selected and used for individual back analysis of the events in the numerical models BING and DAN3D. A best fit rheology is selected from comparing predicted and observed landslide runout behavior. General back analysis to identify the optimal input parameters for the chosen rheology is performed by cross validation, where each debris avalanche is modeled with input parameters from the three other events. Optimal input parameters are found from the model run producing the most accurate runout length and velocity. The Bingham is selected as the best fit rheology, a result differing from similar studies of coarse-grained landslides. A reason for why particularly the frictional rheology proves unsuitable is its tendency to produce too long runout lengths of the low-weight runout material, a result showing important limitations for using the frictional rheology in DAN3D. Optimal Bingham input parameters are τ y = 980 Pa and μ b = 117 Pa/s. However, future studies performed in 2D models are needed for precise parameterization before results can be used for landslide risk assessment. Content Type Journal Article Category Original Paper Pages 1-9 DOI 10.1007/s10346-012-0355-3 Authors Mads-Peter J Dahl, Norwegian Water Resources and Energy Directorate, Middelthunsgate 29, Majorstua, Postbox 5091, 0301 Oslo, Norway Peter Gauer, Norwegian Geotechnical Institute, Postbox 3930,, Ullevaal Stadion, 0806 Oslo, Norway Bjørn G Kalsnes, Norwegian Geotechnical Institute, Postbox 3930,, Ullevaal Stadion, 0806 Oslo, Norway Lis E Mortensen, Jarðfeingi (Faroese Earth and Energy Directorate), Brekkutún 1, Postbox 3059, 0110 Tórshavn, Faroe Islands Niels H Jensen, Department of Environmental, Social and Spatial Change, Roskilde University, Universitetsvej 1, Postbox 260, 4000 Roskilde, Denmark Anita Veihe, Department of Environmental, Social and Spatial Change, Roskilde University, Universitetsvej 1, Postbox 260, 4000 Roskilde, Denmark Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

Tier-based approaches for landslide susceptibility assessment in Europe (Landslides)

Fri, 24 Aug 2012 22:00:00 GMT

Abstract In the framework of the European Soil Thematic Strategy and the associated proposal of a Framework Directive on the protection and sustainable use of soil, landslides were recognised as a soil threat requiring specific strategies for priority area identification, spatial hazard assessment and management. This contribution outlines the general specifications for nested, Tier-based geographical landslide zonings at small spatial scales to identify priority areas susceptible to landslides (Tier 1) and to perform quantitative susceptibility evaluations within these (Tier 2). A heuristic, synoptic-scale Tier 1 assessment exploiting a reduced set of geoenvironmental factors derived from common pan-European data sources is proposed for the European Union and adjacent countries. Evaluation of the susceptibility estimate with national-level landslide inventory data suggests that a zonation of Europe according to, e.g. morphology and climate, and performing separate susceptibility assessments per zone could give more reliable results. To improve the Tier 1 assessment, a geomorphological terrain zoning and landslide typology differentiation are then applied for France. A multivariate landslide susceptibility assessment using additional information on landslide conditioning and triggering factors, together with a historical catalogue of landslides, is proposed for Tier 2 analysis. An approach is tested for priority areas in Italy using small administrative mapping units, allowing for relating socioeconomic census data with landslide susceptibility, which is mandatory for decision making regarding the adoption of landslide prevention and mitigation measures. The paper concludes with recommendations on further work to harmonise European landslide susceptibility assessments in the context of the European Soil Thematic Strategy. Content Type Journal Article Category Original Paper Pages 1-18 DOI 10.1007/s10346-012-0349-1 Authors Andreas Günther, Federal Institute for Geosciences and Natural Resources, Stilleweg 2, 30655 Hannover, Germany Paola Reichenbach, Consiglio Nazionale delle Ricerche, Istituto di Ricerca per la Protezione Idrogeologica, Perugia, Italy Jean-Philippe Malet, Institut de Physique du Globe de Strasbourg (CNRS UMR 7516), Université de Strasbourg/EOST, Strasbourg, France Miet Van Den Eeckhaut, Institute for Environment and Sustainability, Joint Research Centre, European Commission, Ispra, Varese, Italy Javier Hervás, Institute for Environment and Sustainability, Joint Research Centre, European Commission, Ispra, Varese, Italy Claire Dashwood, British Geological Survey, Nottingham, UK Fausto Guzzetti, Consiglio Nazionale delle Ricerche, Istituto di Ricerca per la Protezione Idrogeologica, Perugia, Italy Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

Experimental study on cascading landslide dam failures by upstream flows (Landslides)

Fri, 24 Aug 2012 22:00:00 GMT

Abstract Landslide dams in mountainous areas are quite common. Typically, intense rainfalls can induce upstream flows along the sloping channel, which greatly affects the stability and failure modes of landslide dams. If a series of landslide dams are sequentially collapsed by an incoming mountain torrent (induced by intense rainfall), large debris flows can be formed in a short period of time. This also amplifies the magnitude of the debris flows along the flow direction. The catastrophic debris flows, which occurred in Zhouqu, China on August 8, 2010, were indeed caused by intense rainfall and the upstream cascading failure of landslide dams along the gullies. Experimental tests were conducted in a sloping channel to understand the dynamic process of cascading landslide dam failures and their effect on flow scale amplification. Similar to the Zhouqu conditions, the modeled landslide dams were distributed along a sloping channel and breached by different upstream flows. For each experiment, the front flows were sampled, the entrained grain sizes were analyzed, and the front discharge along the channel was measured. The results of these experiments show that landslide dams occurring along the channel can be destroyed by both high and low discharge flows, although the mechanisms are quite different for the two flow types. Regardless of flow type, the magnitude of the flows significantly increases after a cascading failure of landslide dams, resulting in an increase in both the diameter and the entrained coarse particles percentage. Content Type Journal Article Category Original Paper Pages 1-11 DOI 10.1007/s10346-012-0352-6 Authors Gordon G. D. Zhou, Key Laboratory of Mountain Hazards and Earth Surface Processes, Chinese Academy of Sciences, Chengdu, China P. Cui, Key Laboratory of Mountain Hazards and Earth Surface Processes, Chinese Academy of Sciences, Chengdu, China H. Y. Chen, Key Laboratory of Mountain Hazards and Earth Surface Processes, Chinese Academy of Sciences, Chengdu, China X. H. Zhu, Key Laboratory of Mountain Hazards and Earth Surface Processes, Chinese Academy of Sciences, Chengdu, China J. B. Tang, Key Laboratory of Mountain Hazards and Earth Surface Processes, Chinese Academy of Sciences, Chengdu, China Q. C. Sun, State Key Laboratory for Hydroscience and Engineering, Tsinghua University, Beijing, China Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

Landslide management in the UK—the problem of managing hazards in a ‘low-risk’ environment (Landslides)

Wed, 22 Aug 2012 22:00:00 GMT

Abstract The UK is a country with limited direct experience of natural disasters. Whilst landslide losses are not negligible and fatalities are rare, accounts are under-reported. Financial losses from landslides are poorly understood but likely to be considerably in excess of £10 million per year. As a result, a strategic management framework has evolved based upon small, low-impact events punctuated by occasional larger events or larger landslides affecting urban areas. We present an overview of the different landslide management mechanisms in the UK and discuss them in context of cases studies to explore their effectiveness. We conclude with three issues that may have implications for landslide management in the UK and other ‘low-risk’ countries. Firstly, the evidence base by which landslide hazards and risks are measured is insufficient and limitations in existing information need to be better understood. Secondly, existing guidance on strategic and responsive management needs to be assessed for its fitness for purpose. Thirdly, we encourage debate about the importance of near misses. Content Type Journal Article Category Original Paper Pages 1-12 DOI 10.1007/s10346-012-0346-4 Authors A. D. Gibson, School of Earth and Environmental Sciences, University of Portsmouth, Portsmouth, UK M. G. Culshaw, School of Civil Engineering, University of Birmingham, Birmingham, UK C. Dashwood, British Geological Survey, Nottingham, UK C. V. L. Pennington, British Geological Survey, Nottingham, UK Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

Regression analysis for seismic slope instability based on a double phase viscoplastic sliding model of the rigid block (Landslides)

Wed, 22 Aug 2012 22:00:00 GMT

Abstract Semi-empirical models based on Newmark’s sliding block permit the estimation of expected co-seismic displacements in relation to one or more parameters which characterize the ground motion that theoretically caused them. Taking this into consideration, a regression analysis, based on a double-phase viscoplastic (DPV) model, was developed using 96 Italian ground motion accelerograms for a total of 1,448 combinations obtained for different parametric conditions of the indefinite slope model. Repeated stability analysis, performed by means of the DPV model, allows for the assessment of the seismic instability of a slope in relation to different reached behaviour levels, as well as seismically induced permanent displacements. At these behaviour levels, co-seismic increases and possible subsequent decreases of viscoplastic shear strengths are associated. This implies that the post-seismic persistent mobility (collapse) of the slope can be obtained from the computation. On the other hand, coherently with the increasing of shear resistances during fast sliding displacements in clay soils, the seismic-forced displacements result substantially lower than corresponding values obtained by means of the rigorous Newmark’s sliding block. In addition, in relation to some seismic ground motion parameters, regression and functional border and separation curves were obtained with the aim of providing an expeditious seismic slope stability evaluation in reference to the co-seismic and post-seismic behaviour of clayey slopes. Regarding this, the real behaviour of two historical landslide events is discussed in the light of the results of the regression analysis outlined in this work. Content Type Journal Article Category Original Paper Pages 1-15 DOI 10.1007/s10346-012-0350-8 Authors G. Grelle, University of Sannio, Benevento, Italy F. M. Guadagno, University of Sannio, Benevento, Italy Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

A multidisciplinary approach for rock spreading and block sliding investigation in the north-western coast of Malta (Landslides)

Wed, 01 Aug 2012 22:00:00 GMT

Abstract Landslides are widespread along the north-western coast of the Island of Malta and are strictly linked to the structural setting. Exemplary cases of rock spreading and block sliding phenomena characterise this stretch of coast. They are favoured by the overposition of two different geological units widely outcropping there, the Blue Clay Formation and the Upper Coralline Limestone Formation. The latter forms a wide plateau, bordered by vertical cliffs. At the foot of the cliffs, clayey terrains crop out and develop gentle slopes covered by large blocks detached and moved by rock spreading and block sliding phenomena. These mass movements are favoured by the fragile behaviour of limestones, which cap clays, otherwise characterised by visco-plastic properties. In order to investigate the kinematics and the evolution of these types of coastal landslides, a multidisciplinary and multitechnical approach was applied on a study site, named Il-Prajjet, which provides a spectacular case of rock spreading evolving into block sliding. This paper illustrates the results achieved by means of different engineering geological and geophysical techniques allied with traditional detailed geomorphological survey and mapping. In particular, the surface displacements of the landslides were determined using long-term GPS observations, acquired approximately every 6 months, over a 4.5-year period. A network of GPS benchmarks were distributed on the edge of a limestone plateau affected by rock spreading and on a series of displaced blocks making up a large block slide, finally enabling the definition of the state of activity and the rates of movement to be performed. In addition, the results deriving from two continuous fissurimeters more recently installed at the edge of two persistent joints over the block sliding area are outlined, with reference to the correlation between variations of crack apertures and precipitation input. In order to identify main structural discontinuities and to reconstruct variability of underground surface contact between clays and overlying limestones, Resistivity Tomography profiles and GPR investigations were carried out. Finally, the results obtained by combining the outputs of geophysical surveys and different field monitoring activities can be considered a first step on which numerical models can be developed and validated, in order to assess landslide hazard and risk of this stretch of Maltese coastline. Content Type Journal Article Category Original Paper Pages 1-12 DOI 10.1007/s10346-012-0347-3 Authors Matteo Mantovani, Research Institute for Geo-hydrological Protection, CNR-IRPI. National Research Council of Italy, Corso Stati Uniti 4, 35127 Padua, Italy Stefano Devoto, Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia, Largo S. Eufemia 19, 41121 Modena, Italy Emanuele Forte, Department of Mathematics and Geosciences, University of Trieste, Via E. Weiss 1, 34128 Trieste, Italy Arianna Mocnik, Department of Mathematics and Geosciences, University of Trieste, Via E. Weiss 1, 34128 Trieste, Italy Alessandro Pasuto, Research Institute for Geo-hydrological Protection, CNR-IRPI. National Research Council of Italy, Corso Stati Uniti 4, 35127 Padua, Italy Daniela Piacentini, Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia, Largo S. Eufemia 19, 41121 Modena, Italy Mauro Soldati, Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia, Largo S. Eufemia 19, 41121 Modena, Italy Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

Vulnerability assessment of reinforced concrete buildings subjected to seismically triggered slow-moving earth slides (Landslides)

Fri, 13 Jul 2012 22:00:00 GMT

Abstract The objective of this paper is to develop an efficient analytical method for assessing the vulnerability of low-rise reinforced concrete buildings subjected to seismically induced slow-moving earth slides. Vulnerability is defined in terms of probabilistic fragility curves, which describe the probability of exceeding a certain limit state of the building, on a given slope, versus the Peak Horizontal Ground Acceleration (PHGA) at the assumed “seismic bedrock”, allowing for the quantification of various sources of uncertainty. The proposed method is based on a two-step, uncoupled approach. In the first step, the differential permanent landslide displacements at the building’s foundation level are estimated using a dynamic non-linear finite difference slope model. In the second step, the calculated differential permanent displacements are statically imposed at the foundation level to assess the building’s response to differing permanent seismic ground displacements using a finite element code. Structural limit states are defined in terms of threshold values of strains for the reinforced concrete structural components. The method is applied to typical low-rise reinforced concrete frame buildings on shallow foundations with varying strength and stiffness characteristics (isolated footings and continuous slab foundation), standing near the crest of a relatively slow-moving earth slide. Two different slope models are selected representing a cohesive and a purely frictional soil material. The paper describes the method and the derived fragility curves for the selected building and slope typologies that could be used in quantitative risk assessment studies at site-specific and local scales. Content Type Journal Article Category Original Paper Pages 1-20 DOI 10.1007/s10346-012-0345-5 Authors S D Fotopoulou, Department of Civil Engineering, Laboratory of Soil Mechanics, Foundations and Geotechnical Earthquake Engineering, Aristotle University, Thessaloniki, Greece K D Pitilakis, Department of Civil Engineering, Laboratory of Soil Mechanics, Foundations and Geotechnical Earthquake Engineering, Aristotle University, Thessaloniki, Greece Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

Characteristics of earthquake-induced landslides in a heavy snowfall region—landslides triggered by the northern Nagano prefecture earthquake, March 12, 2011, Japan (Landslides)

Sun, 08 Jul 2012 22:00:00 GMT

Abstract The northern Nagano Prefecture earthquake, MJMA 6.7 (Mw 6.2), which is inferred to have been triggered by the huge (Mw 9.0) March 11, 2011 Tohoku earthquake, occurred on March 12, 2011, in northern Nagano Prefecture, an area in Japan famous for heavy snowfall. A large number of landslides were triggered by the 12 March earthquake, and it caused building damage in the area of the epicenter. To clarify characteristics of the distribution and dynamic behavior of these landslides, we analyzed aerial photographs and conducted field surveys in and around the epicentral area. Large-scale landslides with long distance run-outs are a remarkable characteristic of the landslides induced by this earthquake. The long travel distance is considered to be related to the thick snowpack at the time the earthquake occurred. Moderate scale deep-seated landslides and shallow landslides were also observed in the study area. Based on an analysis of landslides with the active fault on which the earthquake is believed to have occurred, most of these landslides were distributed on the hanging wall of the active fault, within a distance of 12 km from the fault. Content Type Journal Article Category Recent Landslides Pages 1-8 DOI 10.1007/s10346-012-0344-6 Authors Baator Has, Asia Air Survey, Co., Ltd, Kawasaki, Japan Tomoyuki Noro, Snow Avalanche and Landslide Research Center, PWRI, Myoko, Japan Kiyoteru Maruyama, Snow Avalanche and Landslide Research Center, PWRI, Myoko, Japan Akira Nakamura, Snow Avalanche and Landslide Research Center, PWRI, Myoko, Japan Kiichiro Ogawa, Asia Air Survey, Co., Ltd, Kawasaki, Japan Satoshi Onoda, Asia Air Survey, Co., Ltd, Kawasaki, Japan Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

Objective definition of rainfall intensity–duration thresholds for the initiation of post-fire debris flows in southern California (Landslides)

Fri, 29 Jun 2012 22:00:00 GMT

Abstract Rainfall intensity–duration (ID) thresholds are commonly used to predict the temporal occurrence of debris flows and shallow landslides. Typically, thresholds are subjectively defined as the upper limit of peak rainstorm intensities that do not produce debris flows and landslides, or as the lower limit of peak rainstorm intensities that initiate debris flows and landslides. In addition, peak rainstorm intensities are often used to define thresholds, as data regarding the precise timing of debris flows and associated rainfall intensities are usually not available, and rainfall characteristics are often estimated from distant gauging locations. Here, we attempt to improve the performance of existing threshold-based predictions of post-fire debris-flow occurrence by utilizing data on the precise timing of debris flows relative to rainfall intensity, and develop an objective method to define the threshold intensities. We objectively defined the thresholds by maximizing the number of correct predictions of debris flow occurrence while minimizing the rate of both Type I (false positive) and Type II (false negative) errors. We identified that (1) there were statistically significant differences between peak storm and triggering intensities, (2) the objectively defined threshold model presents a better balance between predictive success, false alarms and failed alarms than previous subjectively defined thresholds, (3) thresholds based on measurements of rainfall intensity over shorter duration (≤60 min) are better predictors of post-fire debris-flow initiation than longer duration thresholds, and (4) the objectively defined thresholds were exceeded prior to the recorded time of debris flow at frequencies similar to or better than subjective thresholds. Our findings highlight the need to better constrain the timing and processes of initiation of landslides and debris flows for future threshold studies. In addition, the methods used to define rainfall thresholds in this study represent a computationally simple means of deriving critical values for other studies of nonlinear phenomena characterized by thresholds. Content Type Journal Article Category Original Paper Pages 1-16 DOI 10.1007/s10346-012-0341-9 Authors Dennis M. Staley, U.S. Geological Survey, Box 25046, MS966 DFC, Denver, CO 80225, USA Jason W. Kean, U.S. Geological Survey, Box 25046, MS966 DFC, Denver, CO 80225, USA Susan H. Cannon, U.S. Geological Survey, Box 25046, MS966 DFC, Denver, CO 80225, USA Kevin M. Schmidt, U.S. Geological Survey, Menlo Park, CA, USA Jayme L. Laber, National Oceanic and Atmospheric Administration, National Weather Service, Oxnard, CA, USA Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

Influence of seismic acceleration on landslide susceptibility maps: a case study from NE Turkey (the Kelkit Valley) (Landslides)

Fri, 29 Jun 2012 22:00:00 GMT

Abstract Particularly in the last decade, landslide susceptibility and hazard maps have been used for urban planning and site selection of infrastructures. Most of the procedures for preparing of landslide susceptibility maps need high-quality landslide inventory map. Although the rainfall and seismic activities are accepted as triggering factor for landslides, designation of the triggering factor for each landslide in the inventory is almost impossible when well-documented records are unavailable. Therefore, during preparation of landslide susceptibility map, whole landslide records in the inventory map are used together without classifying based on the triggering factors. Although seismic activity is accepted as a triggering factor, possible effect of the use of seismic activity on production of landslide susceptibility map was investigated in this study, and the subject is open to discussion. For this purpose, a series of stability analyses based on circular failure and infinite slope model were performed considering different pseudostatic conditions. The results of analyses show that gentle slopes have higher susceptibility to failure than steeper ones, even if their stability conditions (susceptibilities) are similar for static condition. The seismic forces acting on failure surfaces may not be sufficiently taken into consideration in the conventionally prepared landslide susceptibility maps. Employing the general decreasing trend in stability condition based on slope face angle and the seismic acceleration, a new procedure was introduced for preparing of the landslide susceptibility map for a scenario earthquake. The prediction performance of occurring landslides increased after the procedure was applied to the conventionally prepared landslide susceptibility map. According to the threshold independent spatial performance analyses of the proposed methodology and the produced landslide susceptibility maps, the area under ROC curve values were calculated as 0.801, 0.933, and 0.947 for the maps prepared by considering conventional method and scenario earthquakes having M w values of 5.5 and 7.5, respectively. Content Type Journal Article Category Original Paper Pages 1-22 DOI 10.1007/s10346-012-0342-8 Authors H. O. Das, General Directorate of the Bank Provinces, Ankara, Turkey H. Sonmez, Department of Geological Engineering, Applied Geology Division, Hacettepe University, 06800 Ankara, Turkey C. Gokceoglu, Department of Geological Engineering, Applied Geology Division, Hacettepe University, 06800 Ankara, Turkey H. A. Nefeslioglu, Department of Geological Engineering, Faculty of Engineering, Cumhuriyet University, 58140 Sivas, Turkey Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

Seasonal movement and groundwater flow mechanism in an unsaturated saprolitic hillslope (Landslides)

Fri, 29 Jun 2012 22:00:00 GMT

Abstract Numerous field monitoring programs have been conducted to investigate the performance of an unsaturated soil slope subjected to rainfalls in wet seasons. Most case histories focus on the response of matric suction, which is one of the two stress-state variables governing unsaturated soil behaviour. However, effects due to another variable, net normal stress, are often ignored. Also, slope performance under alternative wet and dry seasons is rarely reported and analysed. In this study, a saprolitic hillslope situated in Hong Kong was instrumented heavily to investigate its seasonal movement due to changes of the two variables and also groundwater flow mechanism. Two-year seasonal variations of matric suction and net normal stress were monitored by tensiometers together with heat dissipation matric water potential sensors and earth pressure cells, respectively. During heavy rainstorms in wet season, there was a substantial recharge of the main groundwater table, causing a significant increase of positive pore-water pressure in deeper depths. Rupture surface likely developed at depths between 5.5 and 6 m, hence resulting in a “deep-seated” mode of downslope movement. The downslope movement resulted in a peak increase of horizontal stress. In dry seasons, matric suction of up to 190 kPa was recorded, and the associated soil shrinkage led to substantial upslope rebounds. The stress built up in wet seasons hence reduced. After monitoring period of 2 years, downslope ratcheting is identified. Up to 40 % of the downslope displacements were recovered by the upslope rebounds. Content Type Journal Article Category Original Paper Pages 1-13 DOI 10.1007/s10346-012-0343-7 Authors Anthony Kwan Leung, Department of Civil and Environmental Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China Charles Wang Wai Ng, Department of Civil and Environmental Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

Dynamics and mass balance of the 2007 Cima Una rockfall (Eastern Alps, Italy) (Landslides)

Sun, 24 Jun 2012 22:00:00 GMT

Abstract On October 12th, 2007 about 40,000 m3 of dolomitic rock detached from the northern wall of the peak known as “Cima Una” (Val Fiscalina, Sesto Dolomites, Bolzano, Italy), and fell 900 m to Fiscalina Valley below. The event generated a dense dust cloud, which traveled up to 4 km from the source area. The failure surface was formed by two near-vertical surfaces, almost perpendicular to each other. The orientation of these surfaces is consistent with two of the main regional tectonic sets. Only a small portion of the fallen material appeared to be preserved as blocks deposited at the base of the rock wall. About a fifth of the fallen mass was deposited on a colluvial cone. The missing mass, estimated to be about 80 %, may be represented by highly fragmented rock in part deposited as sand on the valley floor and in part dispersed as a dense dust cloud generated during the rockfall. There appears to be a deficit of deposited material, which could lead underestimation in the calculation of rock–cliff recession rates. The dynamics of the rockfall, strongly conditioned by the local topography, partially explains the intense rock breakage and the generation of the dust cloud. The rockfall was not caused by an external trigger, such as an earthquake or heavy rainfall; the failure was most likely progressive due to mechanical and physical degradation along highly stressed failure surfaces, possibly promoted by permafrost degradation and freeze and thaw processes. Content Type Journal Article Category Original Paper Pages 1-16 DOI 10.1007/s10346-012-0338-4 Authors Alessia Viero, Dipartimento di Geoscienze, Università degli Studi di Padova, Padova, Italy Sandro Furlanis, Dipartimento di Scienze della Terra, Università degli Studi di Ferrara, Ferrara, Italy Cristina Squarzoni, Dipartimento di Geoscienze, Università degli Studi di Padova, Padova, Italy Giordano Teza, Dipartimento di Geoscienze, Università degli Studi di Padova, Padova, Italy Antonio Galgaro, Dipartimento di Geoscienze, Università degli Studi di Padova, Padova, Italy Piero Gianolla, Dipartimento di Scienze della Terra, Università degli Studi di Ferrara, Ferrara, Italy Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

ICL strategic plan 2012–2021—To create a safer geo-environment (Landslides)

Sun, 24 Jun 2012 22:00:00 GMT

Abstract The International Consortium on Landslides (ICL) was founded on 21 January 2002, during the United Nations Educational, Scientific and Cultural Organization–Kyoto University Joint Symposium on Landslide Risk Mitigation and Protection of Cultural and Natural Heritage, as an activity of IGCP-425. In its first decade, ICL established the first scientific full-color journal Landslides, a new International Programme on Landslides, organized and held the First World Landslide Forum in 2008 and the Second World Landslide Forum in 2011, and recognized 15 World Centres of Excellence on Landslide Risk Reduction. A 10th anniversary conference was held on 17–20 January at the facility in which ICL’s founding meeting had been held. This conference was jointly organized by ICL and ICL-supporting organizations. During the conference, the ICL Strategic Plan 2012–2021: to create a safer geo-environment—was developed and adopted. This strategic plan accompanies this preface. Content Type Journal Article Category Preface Pages 1-10 DOI 10.1007/s10346-012-0334-8 Authors Kyoji Sassa, ICL, UNITWIN Headquarters Building, Kyoto University Uji-Campus, Uji, Kyoto 611-0011, Japan Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

Potential effects of incoming climate changes on the behaviour of slow active landslides in clay (Landslides)

Mon, 18 Jun 2012 22:00:00 GMT

Abstract Today, a stimulating debate involves the scientific community about the impact of presumable future climate changes on the human life. One of the main question marks concerns their effects on hydrological hazards. Unfortunately, often such a debate is not based on reliable data. The paper proposes a methodology based on the coupling of climatic scenarios and geotechnical analyses accounting for the potential changes in climate parameters. Some analyses have been carried out to forecast the future behaviour of a slow landslide in clay. According to the adopted model, local climate effects should cause a slow decrease in the displacement rate. Content Type Journal Article Category Original Paper Pages 1-19 DOI 10.1007/s10346-012-0339-3 Authors Luca Comegna, Department of Civil Engineering, Seconda Università degli Studi di Napoli, Via Roma 29, 81031 Aversa, Italy Luciano Picarelli, Department of Civil Engineering, Seconda Università degli Studi di Napoli, Via Roma 29, 81031 Aversa, Italy Edoardo Bucchignani, Italian Aerospace Research Center, CIRA, Capua, Italy Paola Mercogliano, Italian Aerospace Research Center, CIRA, Capua, Italy Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

Landslides triggered by slipping-fault-generated earthquake on a plateau: an example of the 14 April 2010, Ms 7.1, Yushu, China earthquake (Landslides)

Mon, 18 Jun 2012 22:00:00 GMT

Abstract On 14 April 2010 at 07:49 (Beijing time), a catastrophic earthquake with Ms 7.1 struck Yushu County, Qinghai Province, China. A total of 2,036 landslides were interpreted from aerial photographs and satellite images, verified by selected field checking. These landslides cover about a total area of 1.194 km2. The characteristics and failure mechanisms of these landslides are presented in this paper. The spatial distribution of the landslides is evidently strongly controlled by the locations of the main co-seismic surface fault ruptures. The landslides commonly occurred close together. Most of the landslides are small; there were only 275 individual landslide (13.5 % of the total number) surface areas larger than 1,000 m2. The landslides are of various types. They are mainly shallow, disrupted landslides, but also include rock falls, deep-seated landslides, liquefaction-induced landslides, and compound landslides. Four types of factors are identified as contributing to failure along with the strong ground shaking: natural excavation of the toes of slopes, which mean erosion of the base of the slope, surface water infiltration into slopes, co-seismic fault slipping at landslide sites, and delayed occurrence of landslides due to snow melt or rainfall infiltration at sites where slopes were weakened by the co-seismic ground shaking. To analyze the spatial distribution of the landslides, the landslide area percentage (LAP) and landslide number density (LND) were compared with peak ground acceleration (PGA), distance from co-seismic main surface fault ruptures, elevation, slope gradient, slope aspect, and lithology. The results show landslide occurrence is strongly controlled by proximity to the main surface fault ruptures, with most landslides occurring within 2.5 km of such ruptures. There is no evident correlation between landslide occurrences and PGA. Both LAP and LND have strongly positive correlations with slope gradient, and additionally, sites at elevations between 3,800 and 4,000 m are relatively susceptible to landslide occurrence; as are slopes with northeast, east, and southeast slope aspects. Q4 al-pl, N, and T3 kn 1 have more concentrated landslide activity than others. This paper provides a detailed inventory map of landslides triggered by the 2010 Yushu earthquake for future seismic landslide hazard analysis and also provides a study case of characteristics, failure mechanisms, and spatial distribution of landslides triggered by slipping-fault generated earthquake on a plateau. Content Type Journal Article Category Original Paper Pages 1-11 DOI 10.1007/s10346-012-0340-x Authors Chong Xu, Key Laboratory of Active Tectonics and Volcano, Institute of Geology, Chinese Earthquake Administration, Qijiahuozi, Deshengmenwai, P.O. Box 9803, Beijing, 100029 People’s Republic of China Xiwei Xu, Key Laboratory of Active Tectonics and Volcano, Institute of Geology, Chinese Earthquake Administration, Qijiahuozi, Deshengmenwai, P.O. Box 9803, Beijing, 100029 People’s Republic of China Guihua Yu, Key Laboratory of Active Tectonics and Volcano, Institute of Geology, Chinese Earthquake Administration, Qijiahuozi, Deshengmenwai, P.O. Box 9803, Beijing, 100029 People’s Republic of China Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

The Second World Landslide Forum, Rome, 2011 and the Third World Landslide Forum, Beijing, 2014 (Landslides)

Sun, 10 Jun 2012 22:00:00 GMT

Abstract The Second World Landslide Forum was held at the headquarters of Food and Agriculture Organization of the United Nations on 3–9 October 2011 in Rome, Italy. The Third World Landslide Forum (WLF3) is to be held at the China National Convention Center in Beijing, China from 2 to 6 June 2014. This article first outlines the aims and background of the World Landslide Forums, reports on the Second World Landslide Forum in Rome, and then announces the plans for the Third World Landslide Forum in Beijing. Finally, it calls for contributions for the organization of WLF3 and participation in the International Consortium on Landslides (ICL) and the International Programme on Landslides. Content Type Journal Article Category ICL/IPL Activities Pages 1-13 DOI 10.1007/s10346-012-0328-6 Authors Kyoji Sassa, International Consortium on Landslides, UNITWIN Headquarters Building, Kyoto University Uji-Campus, Uji, Kyoto, 611-0011 Japan Paolo Canuti, International Consortium on Landslides, Via La Pira 4, 50121 Florence, Italy Claudio Margottini, ISPRA-Institute for Environmental Protection & Research, Geological Survey of Italy, Vitaliano Brancati 60, 00144 Rome, Italy Yueping Yin, China Institute of Geo-Environment Monitoring, China Geological Survey, Dahuist 20#, Haidian, Beijing, China Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

Prediction of piezometric surfaces and drain spacing for horizontal drain design (Landslides)

Sun, 03 Jun 2012 22:00:00 GMT

Abstract Horizontal drains, used independently or as part of a more complex remediation scheme, are frequently installed to mitigate the effects of increased groundwater in slope stabilization projects. Due to a general trial and error approach to their design, the need for improved design practices has been recognized. The procedures established by Crenshaw and Santi in 2004 made some advances in this direction, but did not account for slopes with drains that were not horizontal or for sloping low-permeability layers underneath the slide mass. Furthermore, the method outlined by Crenshaw and Santi is time-consuming and requires some trial and error calculations to achieve convergence. Therefore, the method has been modified to account for nonhorizontal elements, and a horizontal drain spreadsheet has been developed to streamline the design for projects where horizontal drains will be installed. The horizontal drain spreadsheet may be used to: (1) predict a conservative piezometric profile in a drained slope for use in slope stability analyses, (2) predict piezometric heads in any single piezometer in a drainage field, and (3) predict drain spacing for design purposes. This document explains the revisions to Crenshaw and Santi’s procedures and provides instructions for applying the method. The instructions may be used for hand calculations, but are specifically intended for use with the horizontal drain spreadsheet. The spreadsheet may be used for slopes composed of silty or clayey sands, silts, and silty or sandy clays. Content Type Journal Article Category Technical Note Pages 1-10 DOI 10.1007/s10346-012-0337-5 Authors Diana I. Cook, Tetra Tech, 350 Indiana Street, Suite 500, Golden, CO 80401, USA Paul M. Santi, Department of Geology and Geological Engineering, Colorado School of Mines, 1516 Illinois Street, Golden, CO 80401, USA Jerry D. Higgins, Department of Geology and Geological Engineering, Colorado School of Mines, 1516 Illinois Street, Golden, CO 80401, USA Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

How to assess landslide activity and intensity with Persistent Scatterer Interferometry (PSI): the PSI-based matrix approach (Landslides)

Fri, 25 May 2012 22:00:00 GMT

Abstract We provide a step-by-step analysis and discussion of the ‘PSI-based matrix approach’, a methodology employing ground deformation velocities derived through Persistent Scatterer Interferometry (PSI) for the assessment of the state of activity and intensity of extremely to very slow landslides. Two matrices based on PSI data are designed respectively for landslides already mapped in preexisting inventories and for newly identified phenomena. Conversely, a unique intensity scale is proposed indiscriminately for both. Major influencing factors of the approach are brought to light by the application in the 14 km2 area of Verbicaro, in Northern Calabria (Italy). These include lack of PSI data within the landslide boundaries, temporal coverage of the available estimates, and need of field checks as well as the operative procedures to set the activity and intensity thresholds. For the area of Verbicaro, we exploit 1992–2011 PSI data from ERS1/2 and RADARSAT1/2 satellites, projecting them along the maximum slope directions. An activity threshold of ±5 mm/year is determined by applying the average projection factor of local slopes to the PSI data precision. The intensity threshold between extremely and very slow phenomena (16 mm/year) is reduced by ~20 % to account for temporal and spatial averages being applied to attribute representative velocities to each landslide. The methodology allows assessing the state of activity and the intensity for 13 of the 24 landslides premapped in the 2007 inventory and for two newly identified phenomena. Current limitations due to characteristics and spatial coverage of PSI data are critically tackled within the discussion, jointly with respective implications. Content Type Journal Article Category Original Paper Pages 1-17 DOI 10.1007/s10346-012-0335-7 Authors Francesca Cigna, Department of Earth Sciences, University of Firenze, Via La Pira 4, 50121 Firenze, Italy Silvia Bianchini, Department of Earth Sciences, University of Firenze, Via La Pira 4, 50121 Firenze, Italy Nicola Casagli, Department of Earth Sciences, University of Firenze, Via La Pira 4, 50121 Firenze, Italy Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

Terrestrial laser scanning for rockfall stability analysis in the cultural heritage site of Pitigliano (Italy) (Landslides)

Fri, 25 May 2012 22:00:00 GMT

Abstract Traditional surveying methods are often not sufficient to achieve a complete geomechanical characterization of the rock mass, to analyze the instability mechanisms threatening the cultural heritage of hilltop historic towns. In Pitigliano (Tuscany, Central Italy), terrestrial laser scanning was employed complementarily to conventional geomechanical techniques. The overall 3D survey of the exposed surfaces was combined with scanlines of the inner walls of the subterranean cavities running underneath the historic centre. The rock mass discontinuities geometry was extracted, and the most critical instability mechanisms were mapped, with particular interest in the potential impacts on the ancient buildings located along the cliff edge. The geomechanical analysis of the surveyed joint sets confirmed a structural control on the cliff morphology by two main joint sets. Thanks to the laser scanner-based kinematic analysis, flexural toppling and wedge failure were found as the main hazardous instability mechanisms in Pitigliano. Finally, the conservation criticalities were identified and a pilot monitoring system was installed in a sector highly susceptible to block detachment. Content Type Journal Article Category Original Paper Pages 1-12 DOI 10.1007/s10346-012-0329-5 Authors Riccardo Fanti, Department of Earth Sciences, University of Firenze, Via La Pira 4, 50121 Florence, Italy Giovanni Gigli, Department of Earth Sciences, University of Firenze, Via La Pira 4, 50121 Florence, Italy Luca Lombardi, Department of Earth Sciences, University of Firenze, Via La Pira 4, 50121 Florence, Italy Deodato Tapete, Department of Earth Sciences, University of Firenze, Via La Pira 4, 50121 Florence, Italy Paolo Canuti, Department of Earth Sciences, University of Firenze, Via La Pira 4, 50121 Florence, Italy Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

The draining of Matthieu landslide-dam lake, Dominica, West Indies (Landslides)

Mon, 21 May 2012 22:00:00 GMT

Abstract Shortly before midnight on Wednesday, July 27, 2011, the landslide dam forming a lake on the Matthieu River, Dominica, West Indies rapidly breached. The complete draining of the lake caused major flooding along the lower Layou River Valley. No fatalities or injuries resulted despite significant property and infrastructure damage. Government estimates place the cost for immediate cleanup and long-term repairs between ECD9 million and ECD18 million. The lake created by the landslide dam was unusual for having persisted nearly 14 years. Formation of the Matthieu landslide dam was associated with formation and breaching of two smaller landslide dams on the Layou River in 1997. Available evidence is consistent with breaching due to landsliding on the face of the landslide dam. Landslides removed sufficient material to permit the lake to flow over the dam and erode the dam to about the level of the pre-existing channel of the Matthieu River. Content Type Journal Article Category Recent Landslides Pages 1-9 DOI 10.1007/s10346-012-0333-9 Authors Arlington James, Forestry, Wildlife and Parks Division, Windsor Park Link Road, Roseau, Dominica, West Indies Jerome V. De Graff, USDA Forest Service, 1600 Tollhouse Road, Clovis, CA 93611, USA Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

Erratum to: Effect of rock weathering, clay mineralogy, and geological structures in the formation of large landslide, a case study from Dumre Besi landslide, Lesser Himalaya Nepal (Landslides)

Mon, 21 May 2012 22:00:00 GMT

Erratum to: Effect of rock weathering, clay mineralogy, and geological structures in the formation of large landslide, a case study from Dumre Besi landslide, Lesser Himalaya Nepal Content Type Journal Article Category Erratum Pages 1-3 DOI 10.1007/s10346-012-0336-6 Authors Amar Deep Regmi, Shinshu University, Matsumoto, Nagano, Japan Kohki Yoshida, Shinshu University, Matsumoto, Nagano, Japan Megh Raj Dhital, Tribhuvan University, Kritipur, Nepal Krishna Devkota, Kyungpook National University, Deagu, South Korea Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

Towards hydrological triggering mechanisms of large deep-seated landslides (Landslides)

Mon, 21 May 2012 22:00:00 GMT

Abstract It is a widely accepted idea that hydrologically triggered deep-seated landslides are initiated by an increase in pore-water pressure on potential slip surface induced by rising groundwater level after prolonged period of intense rainfall although the process is not fully understood. In order to contribute to better understanding, the rainfall–groundwater relationships, hydrogeological monitoring and repeated geoelectrical imaging were carried out from March 2007 to April 2011 in large deep-seated landslide near Ľubietová (Western Carpathians) catastrophically reactivated at the end of February 1977. Based on our observations, groundwater level (GWL) response to precipitation differs considerably with respect to both overall hydrological conditions and GWL mean depth. While the rate of GWL increase up to 25 cm/day were measured after some rainfall events during wet periods, noticeably lower recharge rate (up to 1–2 cm/day) and delayed GWL response to rainfall (usually from 2 weeks to 2–4 months) were observed at the beginning of the wet season after considerable depression of GWLs due to previous effective rainfall deficit. Likewise, slow GWL fluctuations without short-term oscillations are typical for deeper GWLs. Thus, long-term (several seasons to several years) hydrological conditions affect markedly groundwater response to rainfall events in the studied landslide and can be crucial for its behaviour. Comparison of hydrological conditions characterising the analysed period with those that accompanied the landslide reactivation in 1977 allow us to assume that slightly above-average rainy season following the prolonged wet period can be far more responsible for movement acceleration (and possibly failure initiation) in deep landslides than the isolated season of extreme precipitation following a longer dry period. This is true especially for landslides in regions with significant seasonal temperature changes where potential effective precipitation (PEP), calculated as excess of precipitation (P) over potential evapotranspiration (PET), may be efficiently used for estimation of slope saturation condition. Content Type Journal Article Category Original Paper Pages 1-16 DOI 10.1007/s10346-012-0330-z Authors Roberta Prokešová, Landscape Research Institute, Faculty of Natural Sciences, Matej Bel University, Cesta na amfiteáter 1, 974 01 Banská Bystrica, Slovakia Alžbeta Medveďová, Department of Geography, Geology and Landscape Ecology, Faculty of Natural Sciences, Matej Bel University, Tajovského 40, 974 01 Banská Bystrica, Slovakia Petr Tábořík, Department of Physical Geography and Geoecology, Faculty of Science, University of Ostrava, Chittussiho 10, 710 00 Ostrava, Czech Republic Zora Snopková, Slovak Hydrometeorological Institute, Zelená 5, 974 04 Banská Bystrica, Slovakia Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

Investigation of the 20 August 2005 fatal landslide at Fu Yung Shan Tsuen, Hong Kong (Landslides)

Mon, 14 May 2012 22:00:00 GMT

Abstract On 20 August 2005, a landslide with a volume of about 400 m3 occurred at Fu Yung Shan Tsuen, Tsuen Wan in Hong Kong during a severe rainstorm with a return period of about 100 years on a hillside that has been disturbed locally by past human activities. The incident resulted in one fatality and permanent evacuation of residents of four squatter structures in the vicinity. A forensic investigation into the landslide was carried out to review the mechanism and probable causes of the landslide. The key contributory factors in the landslide were diagnosed. The investigation concluded that the landslide was probably caused by the loss of soil suction and transient build-up of groundwater pressure in the near-surface soil materials following prolonged and intense rainfall. The paper presents the methodology adopted for the landslide study, findings of the investigation and the lessons learnt from this fatal landslide. Content Type Journal Article Category Original Paper Pages 1-13 DOI 10.1007/s10346-012-0332-x Authors K. K. S. Ho, Geotechnical Engineering Office, Civil Engineering and Development Department, Government of the Hong Kong SAR, 101 Princess Margaret Road, Homantin, Kowloon, Hong Kong P. A. Chao, AECOM Asia Company Limited, 20/F Grand Central Plaza, 138 Shatin Rural Committee Road, Shatin, Hong Kong T. M. F. Lau, Geotechnical Engineering Office, Civil Engineering and Development Department, Government of the Hong Kong SAR, 101 Princess Margaret Road, Homantin, Kowloon, Hong Kong S. De Silva, AECOM Asia Company Limited, 20/F Grand Central Plaza, 138 Shatin Rural Committee Road, Shatin, Hong Kong Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

A new slope mass rating in mountainous terrain, Jammu and Kashmir Himalayas: application of geophysical technique in slope stability studies (Landslides)

Sun, 13 May 2012 22:00:00 GMT

Abstract The slopes of western Lesser Himalaya (at Sangaldhan Block of Udhampur near Ramban, Jammu and Kashmir India) are being severely affected by tectonic and erosional activities. These activities result in deposit of a thick cover of rock fragments and overburden just above the hard rock. The thickness of overburden cover has directly affected the stability of slope in the study area, though the traditional stability estimation techniques, rock mass rating and slope mass rating, rate this area as moderately stable which does not represent the real stability condition. In this research work, the geotechnical and geophysical surveys have been carried out to reckon the slope stability conditions more accurately as compared to traditional slope stability estimation techniques. A new rating, new slope mass rating, is developed, which gives a better picture of the stability of slopes. It incorporates a new parameter of overburden thickness profile, along with slope angle and other associated factors on the slopes of the mountainous terrains. The vertical electrical sounding surveys were conducted for the demarcation of rock–overburden interface and for determining the overburden cover. This new classification depicts an increase of 12.84 % in unstable slope areas giving a better assessment and factual picture of slope stability in our study area. This study also enumerates the importance of geophysical applications in slope stability studies. The research work is applicable in mountainous terrains such as Himalaya, and the major component of the application is the orientation of overburden or the profile of thickness in relation with slope of surface. Content Type Journal Article Category Original Paper Pages 1-11 DOI 10.1007/s10346-012-0323-y Authors R. P. Singh, Department of Geology, Centre for Advanced Studies (Environment and Neotectonic Group), University of Delhi, Delhi, 110 007, India C. S. Dubey, Department of Geology, Centre for Advanced Studies (Environment and Neotectonic Group), University of Delhi, Delhi, 110 007, India S. K. Singh, Department of Geology, Centre for Advanced Studies (Environment and Neotectonic Group), University of Delhi, Delhi, 110 007, India D. P. Shukla, Department of Geology, Centre for Advanced Studies (Environment and Neotectonic Group), University of Delhi, Delhi, 110 007, India B. K. Mishra, Department of Geology, Centre for Advanced Studies (Environment and Neotectonic Group), University of Delhi, Delhi, 110 007, India M. Tajbakhsh, Department of Watershed Management, Birjand University, Birjand, Iran P. S. Ningthoujam, Department of Geology, Centre for Advanced Studies (Environment and Neotectonic Group), University of Delhi, Delhi, 110 007, India M. Sharma, Department of Geology, HPU Regional Centre, Dharamshala, Himachal Pradesh, India N. Singh, Department of Geology, Centre for Advanced Studies (Environment and Neotectonic Group), University of Delhi, Delhi, 110 007, India Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

Retraction Note to: Real-time slope water table forecasting by multi-tank model combined with dual ensemble Kalman filter (Landslides)

Sun, 06 May 2012 22:00:00 GMT

Retraction Note to: Real-time slope water table forecasting by multi-tank model combined with dual ensemble Kalman filter Content Type Journal Article Category Retraction Note Pages 1-1 DOI 10.1007/s10346-012-0321-0 Authors Jun Xiong, Department of Urban and Environmental Engineering, Kyoto University, Kyoto, 615-8540 Japan Tomofumi Koyama, Department of Urban and Environmental Engineering, Kyoto University, Kyoto, 615-8540 Japan Satoshi Nisiyama, Department of Urban and Environmental Engineering, Kyoto University, Kyoto, 615-8540 Japan Yuzo Ohnishi, Department of Urban and Environmental Engineering, Kyoto University, Kyoto, 615-8540 Japan Kenji Takahashi, Department of Urban and Environmental Engineering, Kyoto University, Kyoto, 615-8540 Japan Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

Analysis of waves generated by Gongjiafang landslide in Wu Gorge, three Gorges reservoir, on November 23, 2008 (Landslides)

Sun, 06 May 2012 22:00:00 GMT

Abstract At 4:40p.m. on November 23, 2008, the Gongjiafang slope collapsed on the north bank of Yangtze River in Wu Gorge of Three Gorges Reservoir. The 380,000-m3 sliding mass consisted mainly of cataclastic rock. A video record of the major sliding incident was analyzed using the general laws of physical motion. The analysis indicated that the maximum speed and maximum acceleration of the sliding mass were 11.65 m/s and 2.23 m/s2, respectively, and that the maximum amplitude and the propagation velocity of the water wave near the landslide were 31.8 m and 18.36 m/s, respectively. Wave run-up investigation indicated that the maximum run-up on shore was 13.1 m, which declined to 1.1 m at Wushan dock 4 km away. The incident causes no casualties, but did result in economic losses of RMB five million. The numerical simulation model GEOWAVE was used to simulate and reproduced the impulse wave generated by the landslide; the results were in good agreement with the observed incident. The numerical simulation data were then applied to analyze the decay and amplification effects of the landslide wave in the river course. The field investigations and witness information provide valuable materials for the studies of landslide kinematics and impulse waves generated by landslides. In addition, the research results provide a useful reference for future similar waves generated by landslides in reservoirs. Content Type Journal Article Category Recent Landslides Pages 1-11 DOI 10.1007/s10346-012-0331-y Authors Bolin Huang, China University of Geosciences, Wuhan, China 430074 Yueping Yin, China Institute for Geo-Environment Monitoring, Beijing, China 100081 Guangning Liu, Wuhan Centre of China Geological Survey, Wuhan, China 430223 Shichang Wang, Wuhan Centre of China Geological Survey, Wuhan, China 430223 Xiaoting Chen, Wuhan Centre of China Geological Survey, Wuhan, China 430223 Zhitao Huo, Wuhan Centre of China Geological Survey, Wuhan, China 430223 Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

Landslides: A state-of-the art on the current position in the landslide research community (Landslides)

Mon, 16 Apr 2012 22:00:00 GMT

Abstract The international journal Landslides (ISSN 1612-510X), launched in 2004 and published by Springer Verlag, soon gained international recognition as the only specialized scientific journal in the world dedicated to different aspects of landslides, and as one of the leading world journals in the field of geological engineering. After 7 years, seven published volumes with 28 issues and 290 published papers on 2,794 pages, there is time to make a comparison with other related journals that also cover the field of landslide risk mitigation. The critical review of these seven publishing years was done using ISI Journal Citation Reports produced by Thomson Reuters, and available scientometric data from the ISI Web of Knowledge and SCOPUS. The data presented in this paper and the analysis shown may help the Editorial Board to further improve the journal into the direction of a high quality scientific journal with even higher impact on the international research community in the field of landslide risk mitigation. Content Type Journal Article Category Technical Note Pages 541-551 DOI 10.1007/s10346-011-0297-1 Authors Matjaž Mikoš, Faculty of Civil and Geodetic Engineering, University of Ljubljana, Jamova cesta 2, SI-1000 Ljubljana, Slovenia Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X Journal Volume Volume 8 Journal Issue Volume 8, Number 4

Discussion to the paper “Expected damage from displacement of slow-moving slides” by M.F. Mansour, N.R. Morgenstern and C.D. Martin (Landslides)

Mon, 16 Apr 2012 22:00:00 GMT

Discussion to the paper “Expected damage from displacement of slow-moving slides” by M.F. Mansour, N.R. Morgenstern and C.D. Martin Content Type Journal Article Category Discussion Pages 553-555 DOI 10.1007/s10346-011-0292-6 Authors Luciano Picarelli, Department of Civil Engineering, Seconda Universita di Napoli, Aversa, Italy Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X Journal Volume Volume 8 Journal Issue Volume 8, Number 4

ICL-CGS Seminar on Geo-hazards in Xi’an (Landslides)

Mon, 16 Apr 2012 22:00:00 GMT

ICL-CGS Seminar on Geo-hazards in Xi’an Content Type Journal Article Category ICL/IPL Activities Pages 405-405 DOI 10.1007/s10346-011-0289-1 Authors Yueping Yin, China Geological Survey, Xicheng, Huangsidajie No.45, Beijing, 100037 China Xiaochuan Li, China Geological Survey, Xicheng, Huangsidajie No.45, Beijing, 100037 China Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X Journal Volume Volume 8 Journal Issue Volume 8, Number 3

2010 Recipient of the ICL Varnes Medal: Dr. Zaiguan Lin (Landslides)

Mon, 16 Apr 2012 22:00:00 GMT

2010 Recipient of the ICL Varnes Medal: Dr. Zaiguan Lin Content Type Journal Article Category ICL/IPL Activities Pages 403-404 DOI 10.1007/s10346-011-0288-2 Authors Kyoji Sassa, UNITWIN Headquarters Building, Professor Emeritus, Kyoto University, Uji Campus, Uji, Kyoto 611-0011, Japan Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X Journal Volume Volume 8 Journal Issue Volume 8, Number 3

Reconnaissance report on landslide disasters in northeast Japan following the M 9 Tōhoku earthquake (Landslides)

Mon, 16 Apr 2012 22:00:00 GMT

Abstract An earthquake of Mw 9.0 struck the Pacific coast in northeast Japan on March 11, 2011 and was followed by a hugely damaging tsunami along 500 km of the Japanese coastline. An inland aftershock of M. 7.0 occurred on April 11; during which, surface fault ruptures appeared on land. A large variety of landslide disasters resulted from these earthquakes in various parts of northeastern Honshu, Japan. The full extent of the landslides is still being determined. This brief report introduces some of the landslide phenomena so far investigated by the Japanese Landslide Society. These are (1) failure of a water reservoir embankment dam in Sukagawa, Fukushima prefecture, (2) landslides and surface seismic fault rupture from the April 11 aftershock in Iwaki, Fukushima, (3) a concentration of surface failures at Matsushima Bay in Miyagi prefecture, and (4) small landslides on modified slopes in residential areas around Sendai city. Content Type Journal Article Category Recent Landslides Pages 339-342 DOI 10.1007/s10346-011-0281-9 Authors Toyohiko Miyagi, Tōhoku Gakuin University, Tōhoku, Japan Daisuke Higaki, Tōhoku Gakuin University, Tōhoku, Japan Hiroshi Yagi, Tōhoku Gakuin University, Tōhoku, Japan Shoji Doshida, Tōhoku Gakuin University, Tōhoku, Japan Noriyuki Chiba, Tōhoku Gakuin University, Tōhoku, Japan Jun Umemura, Tōhoku Gakuin University, Tōhoku, Japan Go Satoh, Tōhoku Gakuin University, Tōhoku, Japan Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X Journal Volume Volume 8 Journal Issue Volume 8, Number 3

Strong ground motions from the 2011 off-the Pacific-Coast-of-Tohoku, Japan (Mw = 9.0) earthquake obtained from a dense nationwide seismic network (Landslides)

Mon, 16 Apr 2012 22:00:00 GMT

Abstract The dense recordings of the K-NET and KiK-net nationwide strong motion network of 1,189 accelerometers show clearly the radiation and propagation properties of the strong ground motions associated with the 2011 off-the-Pacific Coast-of-Tohoku, Japan (Mw = 9.0) earthquake. The snapshots of seismic wave propagation reveal strong ground motions from this earthquake that originate from three large slips; the first two slips occurred over the plate interface of off-Miyagi at the southwest and the east of the hypocenter, and the third one just beneath the northern end of Ibaraki over the plate interface or in the crust. Such multiple shocks of this event caused large accelerations (maximum 1–2 G) and prolonged ground shaking lasting several minutes with dominant high-frequency (T < 1 s) signals over the entire area of northern Japan. On the other hand, ground motions of relatively longer–period band (T = 1–2 s), which caused significant damage to wooden-frame houses, were about 1/2–1/3 of those observed near the source area of the destructive 1995 Kobe, Japan (M = 7.3) earthquake. Also, the long-period (T = 6–8 s) ground motion in the Kanto (Tokyo) sedimentary basin was at an almost comparable level of those observed during the recent Mw = 7 inland earthquakes, but not as large as that from the former M = 8 earthquakes. Therefore, the impact of the strong ground motion from the present M = 9 earthquake was not as large as expected from the previously M = 7–8 earthquakes and caused strong motion damage only to short-scale construction and according to instruments inside the buildings, both have a shorter (T < 1 s) natural period. Content Type Journal Article Category Recent Landslides Pages 333-338 DOI 10.1007/s10346-011-0279-3 Authors Takashi Furumura, Center for Integrated Disaster Information Research, Interfaculty Initiative in Information Studies, The University of Tokyo, Tokyo, Japan Shunsuke Takemura, The Earthquake Research Institute, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-0032 Japan Shinako Noguchi, Center for Integrated Disaster Information Research, Interfaculty Initiative in Information Studies, The University of Tokyo, Tokyo, Japan Teito Takemoto, The Earthquake Research Institute, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-0032 Japan Takuto Maeda, Center for Integrated Disaster Information Research, Interfaculty Initiative in Information Studies, The University of Tokyo, Tokyo, Japan Kazuhisa Iwai, Center for Integrated Disaster Information Research, Interfaculty Initiative in Information Studies, The University of Tokyo, Tokyo, Japan Simanchal Padhy, Center for Integrated Disaster Information Research, Interfaculty Initiative in Information Studies, The University of Tokyo, Tokyo, Japan Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X Journal Volume Volume 8 Journal Issue Volume 8, Number 3

Glacial hazards in the Rolwaling valley of Nepal and numerical approach to predict potential outburst flood from glacial lake (Landslides)

Sun, 15 Apr 2012 22:00:00 GMT

Abstract In recent years, climate change and retreating glaciers constitute a major hazard in the Himalaya of South Asia. Glacial lakes are rapidly developing or increasing due to climate change. The rapid development of the lake may cause outburst of the lake. The outburst discharge from the glacial lake can cause catastrophic flooding and disaster in downstream area. Therefore, it is necessary to investigate the impact of climate change on glacial lakes and to understand the characteristics of the glacial lake outburst. In this study, the field assessment of Tsho Rolpa Glacial Lake in the Himalaya of Nepal has been presented and the impact of climate change on this glacial lake has been discussed. The Tsho Rolpa Glacial Lake is the largest and most potentially dangerous glacial lake in Nepal. In addition, a numerical model has been also developed for computing the characteristics of glacial lake outburst due to moraine dam failure by seepage and water overtopping. The numerical model is tested for the flume experimental cases. The simulated results of the outburst discharge, the dam surface erosion, and the temporal variation of the moisture movement in the dam are compared with those obtained from the hydraulic model experiments. The moisture profile calculated by numerical model was agreeable with the experimental moisture profile. The simulated failure surface of the dam due to seepage by considering the suction in slope stability analysis gave more agreeable results than the Janbu's simplified method. The results of the outburst discharge and dam surface erosion also agreed with the experimental results. Content Type Journal Article Category Original Paper Pages 1-15 DOI 10.1007/s10346-012-0327-7 Authors Badri Bhakta Shrestha, International Centre for Water Hazard and Risk Management (ICHARM), Public Works Research Institute (PWRI), Tsukuba, Japan Hajime Nakagawa, Disaster Prevention Research Institute (DPRI), Kyoto University, Kyoto, Japan Kenji Kawaike, Disaster Prevention Research Institute (DPRI), Kyoto University, Kyoto, Japan Yasuyuki Baba, Disaster Prevention Research Institute (DPRI), Kyoto University, Kyoto, Japan Hao Zhang, Disaster Prevention Research Institute (DPRI), Kyoto University, Kyoto, Japan Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

Displacement prediction in colluvial landslides, Three Gorges Reservoir, China (Landslides)

Sun, 01 Apr 2012 22:00:00 GMT

ICL/IPL regional activities in West Africa (Landslides)

Wed, 28 Mar 2012 22:00:00 GMT

Abstract Landslides account for huge amount of property damage in virtually every part of the world. The 2011 Iva Valley debris flow in Enugu, Nigeria; the 2010 landslide in Bududa region, 275 km east of Kampala, Uganda; the 2010 debris avalanche in Benue state, Nigeria; the 2008 landslide in Congo; and the 2007 landslide in western Cameroon with a combined human death of over 4,000 remain a modern day illustration of the degree of threat to public safety catastrophic landslides symbolize. Landslides do not only destroy lives and resources, they also deface and devalue historical, cultural, and entertainment facilities critical to the survival of man. Taming their aggression and ruinous impacts, thereby rescuing the environment from potential crisis, should, in point of fact, become a priority. In West Africa, landslides cause losses worth several millions of dollars annually. Nigeria remains one of the most vulnerable places. In both the southern and northern divide of the country, there is a mix of sedimentary, igneous, and metamorphic rocks which provide a good basis for the application of geology to urban development and hazard zonation in Nigeria. Quite often, similar engineering geologic problems including landslides and rockfalls, foundation problems in montmorilonite-rich clayey soils and problems associated with abandoned mines have been observed in both divides. The ICL/IPL program attempts to evaluate the engineering geologic problems in these two zones and provide case histories as illustrations. Experience gained in one area may be applied regionally to tackle problems in any other area with similar geology. Content Type Journal Article Category ICL/IPL Activities Pages 1-5 DOI 10.1007/s10346-012-0324-x Authors Ogbonnaya Igwe, Department of Geology, University of Nigeria, Nsukka, Enugu State, Nigeria Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

Effect of anisotropic conductivity on suction and reliability index of unsaturated slope exposed to uniform antecedent rainfall (Landslides)

Sun, 25 Mar 2012 22:00:00 GMT

Movement of deep-seated rainfall-induced landslide at Hsiaolin Village during Typhoon Morakot (Landslides)

Sun, 25 Mar 2012 22:00:00 GMT

Abstract This study analyzes the mechanism of the landslide event at Hsiaolin Village during Typhoon Morakot in 2009. This landslide event resulted in 400 deaths. The extremely high intensity and accumulative rainfall events may cause large-scale and complex landslide disasters. To study and understand a landslide event, a combination of field investigations and numerical models is used. The landslide area is determined by comparing topographic information from before and after the event. Physiographic parameters are determined from field investigations. These parameters are applied to a numerical model to simulate the landslide process. Due to the high intensity of the rainfall event, 1,675 mm during the 80 h before the landslide event, the water content of soil was rapidly increased causing a landslide to occur. According to the survivors, the total duration of the landslide run out was less than 3 min. Simulation results indicated that the total duration was about 150 s. After the landslide occurrence, the landslide mass separated into two parts by a spur at EL 590 in about 30 to 50 s. One part passed the spur in about 30 to 60 s. One part inundated the Hsiaolin Village and the other deposited at a local river channel and formed a landslide dam. The landslide dam had height between 50 and 60 m and length between 800 and 900 m. The simulation result shows that the proposed model can be used to evaluate the potential areas of landslides induced by extremely high intensity rainfall events. Content Type Journal Article Category Original Paper Pages 1-12 DOI 10.1007/s10346-012-0315-y Authors Yu-Shu Kuo, Department of Hydraulic and Ocean Engineering, National Cheng-Kung University, Tainan, Taiwan, Republic of China Yuan-Jung Tsai, Department of Hydraulic and Ocean Engineering, National Cheng-Kung University, Tainan, Taiwan, Republic of China Yu-Shiu Chen, Disaster Prevention Research Center, National Cheng-Kung University, Tainan, Taiwan, Republic of China Chjeng-Lun Shieh, Department of Hydraulic and Ocean Engineering, National Cheng-Kung University, Tainan, Taiwan, Republic of China Kuniaki Miyamoto, Graduate School of Life and Environmental Sciences, University of Tsukuba, Ibaraki, Japan Takahiro Itoh, Research and Development Center, NIPPON KOEI CO., LTD., Ibaraki, Japan Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

Mapping landslide susceptibility with logistic regression, multiple adaptive regression splines, classification and regression trees, and maximum entropy methods: a comparative study (Landslides)

Fri, 09 Mar 2012 23:00:00 GMT

Locating, monitoring, and characterizing typhoon-linduced landslides with real-time seismic signals (Landslides)

Wed, 07 Mar 2012 23:00:00 GMT

Abstract Landslides induced by typhoon Morakot during its passage across Taiwan on 7–9 Aug 2009 claimed more than 700 lives and caused heavy economic loss. Unlike earthquake monitoring, precise locations of landslides could not be determined in near-real time because their seismic phases are difficult to identify. Here, we show that large, damaging landslide events are characterized seismically by a distinct waveform pattern of frequent intermixes of P and S waves over a time window of several tens of seconds. The predominant frequency band during these time windows ranges from 0.5 to 5 Hz. The high-frequency content is clearly deficient relative to that of local earthquakes by about one to two orders. We also demonstrate that large landslide events can be located and monitored with algorithms specifically designed for real-time seismic applications. This near-real-time monitoring capability would be particularly useful for emergency responders and government organizations to coordinate effective relief-and-rescue operations. Content Type Journal Article Category Technical Note Pages 1-7 DOI 10.1007/s10346-012-0322-z Authors Honn Kao, Geological Survey of Canada, Pacific Geoscience Centre, 9860 West Saanich Road, Sideny, BC V8L 4B2 Canada Chih-Wen Kan, Central Weather Bureau, 64, Gongyuan Road, Taipei, 10048 Taiwan Rong-Yuh Chen, Central Weather Bureau, 64, Gongyuan Road, Taipei, 10048 Taiwan Chien-Hsin Chang, Central Weather Bureau, 64, Gongyuan Road, Taipei, 10048 Taiwan Andreas Rosenberger, Geological Survey of Canada, Pacific Geoscience Centre, 9860 West Saanich Road, Sideny, BC V8L 4B2 Canada Tzay-Chyn Shin, Central Weather Bureau, 64, Gongyuan Road, Taipei, 10048 Taiwan Pei-Ling Leu, Central Weather Bureau, 64, Gongyuan Road, Taipei, 10048 Taiwan Kai-Wen Kuo, Central Weather Bureau, 64, Gongyuan Road, Taipei, 10048 Taiwan Wen-Tzong Liang, Institute of Earth Sciences, Academia Sinica, 128, Sec. 2, Academia Road, Nangang, Taipei 11529 Taiwan Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

Development of a new translational and rotational slides prediction model in Langhe hills (north-western Italy) and its application to the 2011 March landslide event (Landslides)

Fri, 02 Mar 2012 23:00:00 GMT

Effect assessment of debris flow mitigation works based on numerical simulation by using Kanako 2D (Landslides)

Fri, 17 Feb 2012 23:00:00 GMT

Kinematics and internal deformation of granular slopes: insights from discrete element modeling (Landslides)

Fri, 17 Feb 2012 23:00:00 GMT

A regional scale quantitative risk assessment for landslides: case of Kumluca watershed in Bartin, Turkey (Landslides)

Wed, 15 Feb 2012 23:00:00 GMT

Abstract The paper proposes a methodology for quantitative landslide risk assessment for regional-scale analysis. Each component of risk, i.e., hazard, vulnerability, and consequence analysis, is quantitatively assessed. The developed landslide risk assessment methodology is tested in Kumluca watershed, in Bartın, Turkey. Geographic information systems and remote sensing techniques are used to create landslide factor maps, to obtain susceptibility maps, hazard maps, elements at risk, and risk maps. Susceptibility maps are obtained by using a logistic regression model while adopting a grid-based mapping unit. In addition to spatial probability of occurrence of damaging events, landslide hazard calculation requires the determination of the temporal probability. Precipitation triggers the majority of landslides in the study region. The critical rainfall thresholds were estimated by using antecedent rainfalls and landslide occurrence dates based on Gumble Distribution approach. The elements at risk are extracted from existing digital cadastral databases and the vulnerabilities are obtained by adopting some generalization approaches. To conclude, quantitative risk maps were produced on a continuous scale where numerical values indicate the distribution of risk including the annual probability of expected losses in TL per pixel and the annual probability of life loss per pixel for property and life, respectively. For the considered case study, it is found that the annual probability of property loss is the highest for the provincial highway and the provincial road. The property loss map highlights that the annual expected loss to power network is medium. The annual probability of life loss map illustrates that the region surrounded by Kumluca town, Kızıllar, and Zafer villages have medium and high annual expected loss of population values, respectively. Content Type Journal Article Category Original Paper Pages 1-19 DOI 10.1007/s10346-012-0317-9 Authors Arzu Erener, Department of Geomatics Engineering, Faculty of Engineering and Architecture, Selcuk University, Konya, Turkey H. B. Sebnem Düzgün, Department of Mining Engineering, Middle East Technical University (METU), Ankara, Turkey Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

Empirical and analytical analyses of laboratory granular flows to investigate rock avalanche propagation (Landslides)

Mon, 30 Jan 2012 23:00:00 GMT

Abstract Laboratory experiments which consist of releasing dry rigid non-cohesive grains or small bricks on an unconfined chute have been designed to investigate rock avalanche propagation mechanisms and to identify parameters influencing their deposit characteristics. Factors such as volume, fall height, basal friction angle, material used, structure of the material before release, i.e. bricks randomly poured into the reservoir before failure or piled orderly one on top of the other, and type of slope break, i.e. curved or sharp angular, are considered and their influence on apparent friction angle, travel angle of the centre of mass, deposit length and runout is analysed. Results highlight the influence of the structure of the material before release and of the type of transition at the toe of the slope on the mobility of granular avalanches. The more angular and sharp is the slope break, the more shearing (friction) and collisions will develop within the sliding mass as it changes its flow direction, the larger will be the energy dissipation and the shorter will be the travel distance. Shorter runout is also observed when bricks are randomly poured into the reservoir before release compared to when they are piled one on top of the other. In the first case, more energy is dissipated all along the flow through friction and collisions within the mass. Back analysis with a sled block model of experiments with a curved slope break underlines the importance of accounting centripetal acceleration in the modelling of the distance travelled by the centre of mass of a granular mass. This type of model though is not able to assess the spreading of the mass and its total runout because it does not take into account the internal deformation and the transfer of momentum within the mass which, as highlighted by the experimental results, play an important role in the mobility of rock avalanches. Content Type Journal Article Category Original Paper Pages 1-14 DOI 10.1007/s10346-011-0313-5 Authors Irene Manzella, Rock Mechanics Laboratory, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland Vincent Labiouse, Rock Mechanics Laboratory, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

Effect of rock weathering, clay mineralogy, and geological structures in the formation of large landslide, a case study from Dumre Besei landslide, Lesser Himalaya Nepal (Landslides)

Fri, 20 Jan 2012 23:00:00 GMT

Abstract The Dumre Besi landslide is one of the largest and most problematic failures on the Mugling–Narayanghat Highway in central Nepal. Though it was triggered by the monsoon rain of 2003, geological structures and rock weathering have played a key role in its initiation and further aggravation. The slide is also controlled to some extent by the groundwater and rugged topography with high slope angles. The landslide zone comprises thinly laminated light grey siltstone with numerous crosscutting quartz veins, grey metasandstone (quartzite), bluish grey to white phyllite, black carbonaceous slate, and dolomite. A thrust fault passes through the centre of the landslide, creating a thick deposit of loose, weathered rock material, and the fault has developed a very thick shattered zone where weathering is very intense. Using field and laboratory analyses, the rocks in the landslide zone can be divided into five zones based on the severity of weathering: none, slight, moderate, severe, and complete. Laboratory analyses showed that the chemically weathered rocks are significantly rich in smectite and vermiculite. Out of these, smectite is the most critical one, as it swells when wet. The formation mechanism of the clay minerals was analysed by various techniques, including X-ray diffraction, X-ray fluorescence, and thin-section analysis, and it was found that most of them were derived from weathering of rock. The clay minerals significantly reduced the rock strength and facilitated the extensive failure of Dumre Besi. The wide fault zone with deeply weathered and clay-rich debris is also responsible for the formation of debris flows in the monsoon season. Content Type Journal Article Category Original Paper Pages 1-13 DOI 10.1007/s10346-011-0311-7 Authors Amar Deep Regmi, Shinshu University, Matsumoto, Nagano, Japan Kohki Yoshida, Shinshu University, Matsumoto, Nagano, Japan Megh Raj Dhital, Tribhuvan University, Kritipur, Nepal Krishna Devkota, Kung Puk National University, Degu, South Korea Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

Rockfalls detached from a lateral moraine during spring season. 2010 and 2011 events observed at the Rebaixader debris-flow monitoring site (Central Pyrenees, Spain) (Landslides)

Tue, 17 Jan 2012 23:00:00 GMT

Abstract Instability processes at glacial deposits represent an important hazard in mountainous areas. During the spring seasons of 2010 and 2011, two falls of large boulders (18 and 55 m3) initiated in a lateral moraine in the Rebaixader catchment (Central Pyrenees, Spain). Detailed information was gathered due to the debris-flow monitoring system installed along the torrent. Meteorological data showed that the two rockfalls were triggered without important rainfall amounts. Field surveys, ground vibration acquired at geophones and the movie recorded with a video camera provided unique information on the rockfall occurrence and dynamics. In addition, the information gave an excellent opportunity to show the importance of monitored data for the calibration of model parameters for runout simulations. The analysis focussed on the 2011 event and showed that the boulder passed rolling and bouncing through the monitored torrent reach. The velocity estimates in this reach range from 3 to 9 m/s. The 2011 rockfall was also back-analysed by a two-dimensional physically based model, which was fitted by the monitored and field data. The results of the simulation coincided well with recorded measurements, although the output could be improved by the application of a three-dimensional model. Content Type Journal Article Category Recent Landslides Pages 1-9 DOI 10.1007/s10346-011-0314-4 Authors Marcel Hürlimann, Department of Geotechnical Engineering and Geosciences, Technical University of Catalonia (UPC), Jordi Girona 1-3 (D2), 08034 Barcelona, Spain Clàudia Abancó, Department of Geotechnical Engineering and Geosciences, Technical University of Catalonia (UPC), Jordi Girona 1-3 (D2), 08034 Barcelona, Spain José Moya, Department of Geotechnical Engineering and Geosciences, Technical University of Catalonia (UPC), Jordi Girona 1-3 (D2), 08034 Barcelona, Spain Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

Experimental studies of groundwater pipe flow network characteristics in gravelly soil slopes (Landslides)

Tue, 17 Jan 2012 23:00:00 GMT

Abstract Piping flow networks have often been identified in hydrogeological field studies of gravelly soil slopes in the southern part of China. The present experimental studies have shown that under long-term groundwater seepage, piping flow networks gradually develop in the slope. Factors affecting the development of flow pipe seepage network included the grain size distribution, the degree of soil compaction, and soil depth. Piping seepage networks favorably form if the content of the gravel was high, the soil cohesion was low, the degree of the soil compaction was low, or the soil depth was shallow. Due to the enhanced permeability associated with the presence of flow pipe seepage network in gravelly soil slopes, groundwater can be effectively drained away. This can beneficially prevent the rise of groundwater level in the slope during raining seasons, hence reducing pore water pressure along the potential failure surface and increasing slope stability. Once the flow pipe seepage network was disturbed or damaged, the water level in the upper portion of the slope experienced a great rise, hence reducing the slope stability. Therefore, slope toe excavation and excessive loading at the slope crest should be avoided for slopes with well-developed flow pipe seepage network in order to preserve it. Content Type Journal Article Category Original Paper Pages 1-9 DOI 10.1007/s10346-011-0312-6 Authors Hong-yue Sun, Department of Ocean Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310058, China Louis Ngai Yuen Wong, School of Civil and Environmental Engineering, Nanyang Technological University, Singapore, 639798 Singapore Yue-quan Shang, College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, Zhejiang 310058, China Bo-ting Yu, College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, Zhejiang 310058, China Zhi-lei Wang, College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, Zhejiang 310058, China Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

Control of landslide retrogression by discontinuities: evidence by the integration of airborne- and ground-based geophysical information (Landslides)

Thu, 05 Jan 2012 23:00:00 GMT

Abstract The objective of this work is to present a multitechnique approach to define the geometry, the kinematics, and the failure mechanism of a retrogressive large landslide (upper part of the La Valette landslide, South French Alps) by the combination of airborne and terrestrial laser scanning data and ground-based seismic tomography data. The advantage of combining different methods is to constrain the geometrical and failure mechanism models by integrating different sources of information. Because of an important point density at the ground surface (4. 1 points m−2), a small laser footprint (0.09 m) and an accurate three-dimensional positioning (0.07 m), airborne laser scanning data are adapted as a source of information to analyze morphological structures at the surface. Seismic tomography surveys (P-wave and S-wave velocities) may highlight the presence of low-seismic-velocity zones that characterize the presence of dense fracture networks at the subsurface. The surface displacements measured from the terrestrial laser scanning data over a period of 2 years (May 2008–May 2010) allow one to quantify the landslide activity at the direct vicinity of the identified discontinuities. An important subsidence of the crown area with an average subsidence rate of 3.07 m year–1 is determined. The displacement directions indicate that the retrogression is controlled structurally by the preexisting discontinuities. A conceptual structural model is proposed to explain the failure mechanism and the retrogressive evolution of the main scarp. Uphill, the crown area is affected by planar sliding included in a deeper wedge failure system constrained by two preexisting fractures. Downhill, the landslide body acts as a buttress for the upper part. Consequently, the progression of the landslide body downhill allows the development of dip-slope failures, and coherent blocks start sliding along planar discontinuities. The volume of the failed mass in the crown area is estimated at 500,000 m3 with the sloping local base level method. Content Type Journal Article Category Original Paper Pages 1-18 DOI 10.1007/s10346-011-0310-8 Authors J. Travelletti, Institut de Physique du Globe de Strasbourg, CNRS UMR 7516, University of Strasbourg (EOST), 5 rue René Descartes, 67084 Strasbourg Cedex, France J.-P. Malet, Institut de Physique du Globe de Strasbourg, CNRS UMR 7516, University of Strasbourg (EOST), 5 rue René Descartes, 67084 Strasbourg Cedex, France K. Samyn, Bureau des Recherches Géologiques et Minières (BRGM), 3 Avenue Guillemin, Orléans, France G. Grandjean, Bureau des Recherches Géologiques et Minières (BRGM), 3 Avenue Guillemin, Orléans, France M. Jaboyedoff, Institute of Geomatics and Analysis of Risk (IGAR), University of Lausanne, Lausanne, Switzerland Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X

The monitoring of slow-moving landslides and assessment of stabilisation measures using an optical–mechanical crack gauge (Landslides)

Thu, 05 Jan 2012 23:00:00 GMT

Abstract It is possible to monitor slow-moving landslides and assess landslide stabilisation measures over protracted periods using an optical–mechanical crack gauge called a TM-71. This technical note outlines the theoretical background to the gauge and illustrates its practical application through a number of case studies. These studies are drawn from a range of landslide types and stabilisation measures. In terms of monitoring slow-moving landslides, three studies of deep-seated deformations are presented. The Taukliman coastal landslide on the Black Sea Coast is characterised by vertical and horizontal displacements of up to 0.2 mm year−1 and sudden earthquake-induced dilations of up to 6 mm. The Parohy ridge spreading landslide in the Malá Fatra Mountains is characterised by gravitationally induced vertical displacements of 0.7 mm year−1. The slope deformation that formed Cyrilka Cave in the Beskydy Mountains is characterised by very slow sinistral strike–slip movements of 0.8 mm year−1. In terms of assessing landslide stabilisation measures, two studies are presented from Orava Castle in Slovakia and Tetín in the Czech Republic. The data recorded at these sites demonstrate that the constructed stabilisation measures have successfully alleviated the potential landslide hazard in both localities. These case studies clearly demonstrate that the gauge represents an important tool with which to monitor slow-moving landslides and assess landslide stabilisation measures. It is able to provide a precise three-dimensional record of deformation, withstand harsh environmental conditions, and record reliable data over protracted periods. Content Type Journal Article Category Technical Note Pages 1-9 DOI 10.1007/s10346-011-0306-4 Authors J. Klimeš, Department of Engineering Geology, Institute of Rock Structure and Mechanics, Academy of Sciences of the Czech Republic, V Holešovičkách 41, 182 09 Prague 8, Czech Republic M. D. Rowberry, Department of Engineering Geology, Institute of Rock Structure and Mechanics, Academy of Sciences of the Czech Republic, V Holešovičkách 41, 182 09 Prague 8, Czech Republic J. Blahůt, Department of Engineering Geology, Institute of Rock Structure and Mechanics, Academy of Sciences of the Czech Republic, V Holešovičkách 41, 182 09 Prague 8, Czech Republic M. Briestenský, Department of Engineering Geology, Institute of Rock Structure and Mechanics, Academy of Sciences of the Czech Republic, V Holešovičkách 41, 182 09 Prague 8, Czech Republic F. Hartvich, Department of Engineering Geology, Institute of Rock Structure and Mechanics, Academy of Sciences of the Czech Republic, V Holešovičkách 41, 182 09 Prague 8, Czech Republic B. Košťák, Department of Engineering Geology, Institute of Rock Structure and Mechanics, Academy of Sciences of the Czech Republic, V Holešovičkách 41, 182 09 Prague 8, Czech Republic J. Rybář, Department of Engineering Geology, Institute of Rock Structure and Mechanics, Academy of Sciences of the Czech Republic, V Holešovičkách 41, 182 09 Prague 8, Czech Republic J. Stemberk, Department of Engineering Geology, Institute of Rock Structure and Mechanics, Academy of Sciences of the Czech Republic, V Holešovičkách 41, 182 09 Prague 8, Czech Republic P. Štěpančíková, Department of Engineering Geology, Institute of Rock Structure and Mechanics, Academy of Sciences of the Czech Republic, V Holešovičkách 41, 182 09 Prague 8, Czech Republic Journal Landslides Online ISSN 1612-5118 Print ISSN 1612-510X