ALBERT

Description: Preparation of reliable landslide hazard and risk maps is crucial for hazard mitigation and risk management. In recent years, various approaches have been developed for quantitative assessment of landslide hazard and risk. However, possibly due to the lack of new data, very few of these hazard and risk maps were updated after their first generation. In this study, aiming at an ongoing assessment, a novel approach for updating landslide hazard and risk maps based on Persistent Scatterer Interferometry (PSI) is introduced. The study was performed in the Arno River basin (central Italy) where most mass movements are slow-moving landslides which are properly within the detection precision of PSI point targets. In the Arno River basin, the preliminary hazard and risk assessment was performed by Catani et al. (Landslides 2:329–342, 2005) using datasets prior to 2002. In this study, the previous hazard and risk maps were updated using PSI point targets processed from 4 years (2003–2006) of RADARSAT images. Landslide hazard and risk maps for five temporal predictions of 2, 5, 10, 20 and 30 years were updated with the exposure of losses estimated in Euro (€). In particular, the result shows that in 30 years a potential loss of approximate €3.22 billion is expected due to these slow-moving landslides detected by PSI point targets.

Description: Modelling the design and implementation of urban water infrastructure (particularly decentralised systems) for strategic planning and policymaking requires detailed information of the spatial environment and quantitative knowledge of social preferences. Currently available models, however, mostly use land use, population and impervious cover data without much regard for detailed urban form or society. This study develops an algorithm for determining urban form from minimal spatial data input by incorporating local planning regulations. The interaction between urban form and implementation of lot-scale infiltration systems under different social, biophysical and climate constraints is then investigated, firstly by looking at how this varies in different residential land uses and subsequently in a case study of a typical Melbourne residential subdivision of mixed land uses. Feasibility of infiltration and its downstream impact (runoff volume, frequency and pollution) were assessed for a range of social preferences (quantified as allowable garden space) and climate scenarios (30 % increase/decrease in rainfall and evapotranspiration). Performance indicators were determined through long-term simulation with the MUSIC software. Results show how different biophysical, planning, social and climate conditions affect infiltration feasibility as well as system performance. High infiltrating soils, for example, allow smaller, well-performing and socially less-imposing systems. Low infiltrating soils lead to larger system sizes, occupy much of the allotment’s garden space, but nevertheless provide the benefit of runoff frequency reduction. Overall, climate impact was not significant except for areas with poorly infiltrating soils. Joint consideration of social, planning, climate and water management aspects potentially allows more efficient policymaking, as an array of system configurations can be tested against different multi-faceted scenarios. Such models can help facilitate better participatory planning and policymaking.

Description: Cities in developed countries have increasingly adopted rainwater tanks as an alternative water source over the last 15 years. The rapid uptake of rainwater tanks has been driven by the need to reduce demand for centralised water services that are under pressure to adapt to population growth and climate change impacts. Rainwater tanks are part of integrated urban water management approach that considers the whole water cycle to provide water services on a fit for purpose basis that minimises the impact on the local environment and receiving waters. Rainwater tanks are typically applied at the household scale for non-potable water source uses such as toilet flushing and garden irrigation. However, this paper reports on a communal approach to rainwater harvesting, where the water is treated for potable use. A communal approach to rainwater harvesting can offer benefits, such as: economies of scale for capital costs, reduced land footprint, centralised disinfection and flexibility in matching supply and demand for different households. The analysis showed that the communal approach could provide a reliable potable water source to a small urban development. However, there was an energy penalty associated with this water source compared to centralised systems that could be addressed through more appropriate pump sizing. The outputs from this monitoring and modelling study demonstrated rainwater harvesting can be expanded beyond the current mainstream practices of household systems for non-potable use in certain development contexts. The analysis contained in this paper can be used for the improved planning and design of communal approaches to rainwater harvesting.

Description: The main purpose of this paper is to evaluate the global performance and to assess the current trends in research of water resource management. The methods of informetric analysis were used to survey water resource management related articles in the Science Citation Index (SCI) and Social Science Citation Index (SSCI) during the past decades. The publication records, subjects, journals, countries, institutes, authors, citations and keywords were analyzed respectively for each paper. The number of papers related to water resource management in 2012 was approximately 8 times that of the year 2000 and hundreds of times more than early 1990s. Water resource management related papers were distributed unevenly by countries. The USA, P.R. China, Australia and UK were the top contributing countries, also present normalized by dividing with population that published most SCI papers as well as SSCI papers. The largest water resource management research center is located in the USA according to the number of publications and citations, with P.R. China becoming more proficient in water resource management according to the data from country and institute. In addition, the quality of papers produced by developed countries is more advanced than developing countries. All these efforts contributed to the indication in trends of water resource management research on a global scale. Earlier water resource management research appeared and was originally concentrated on engineering, irrigation and geography. Issues gradually transferred to management, economics and regime recently.

Description: A remote sensing-based approach to estimate actual evapotranspiration ( ET ) was tested in an area covered by olive trees and characterized by Mediterranean climate. The methodology is a modified version of the standard FAO-56 dual crop coefficient procedure, in which the crop potential transpiration, T p, is obtained by directly applying the Penman-Monteith (PM) equation with actual canopy characteristics (i.e., leaf area index, albedo and canopy height) derived from optical remote sensing data. Due to the minimum requirement of in-situ ancillary inputs, the methodology is suitable also for applications on large areas where the use of tabled crop coefficient values become problematic, due to the need of corrections for specific crop parameters, i.e., percentage of ground cover, crop height, phenological cycles, etc. The methodology was applied using seven airborne remote sensing images acquired during spring-autumn 2008. The estimates based on PM approach always outperforms the ones obtained using simple crop coefficient constant values. Additionally, the comparison of simulated daily evapotranspiration and transpiration with the values observed by eddy correlation and sap flow techniques, respectively, shows a substantial agreement during both dry and wet days with an accuracy in the order of 0.5 and 0.3 mm d −1 , respectively. The obtained results suggest the capability of the proposed approach to correctly partition evaporation and transpiration components during both the irrigation season and rainy period also under conditions of significant reduction of actual ET from the potential one.

Description: Seasonality characteristics and spatio-temporal trends of 7-day low flows were investigated for the 41,470 km 2 semi-arid Karkheh watershed (western Iran), representing 12 stations with record length of 51 years (1958–2008). Hierarchical Cluster Analysis (HCA) was used to identify low-flow seasonality (clusters of low flow seasons). Monotonic trends were detected by the Mann-Kendall test. Breaks in low flow trends were detected by the Lombard’s change point test. Breaks in short-term trends were detected by the Lepage test. According to results seasonal clusters were different in most of the stations, indicating uniqueness in station low flow behaviour. Among the 12 stations studied, four stations showed seasonal monotonic trend and change points, some with abrupt change (change point in consecutive years). Two stations near watershed outlet with no monotonic trend showed abrupt change. Most seasonal change points (dates) compared well with documented droughts, highlighting drought impacts on low flow trends at affected stations. The Lepage test detected change point in seasonal low flow trends of most stations during 5- and 10-year periods. This research has shown that in semi-arid environments low flow seasonality characteristics may vary among stations, an indication that low flow trends should be evaluated individually for each station.

Description: With the transformation of water conservancy from traditional to eco-hydraulic aiming at sustainable development, the study on eco-efficiency of the water system has attracted a great deal of attention. This study aims to develop a methodology for evaluating the eco-efficiency of water systems of 31 administrative regions in China. Considering the multiple attributes of water systems and a piecewise linear technological frontier, the Rough Set Theory (RST) and Data Envelopment Analysis model (DEA) are combined to analyze the eco-efficiency of water systems. An input-and-output index system is established based on RST. The eco-efficiency for the water system of 31 administrative regions in China is calculated by DEA, and the characteristics of its spatial differences are discussed. The results show that there is a significant difference in the eco-efficiency of water systems: (1) On the whole, the efficiency value of north China is slightly higher than the south; (2) In the eight sub-regions of China, the north coastal area gains the highest efficiency score and the middle reaches of the Yangtze River obtains the lowest value; (3) There are 11 out of 31 regions at the best practice frontier. The spatial difference in eco-efficiency of the water system is a common phenomenon, which reflects the direct or indirect influence by economical, political, legislative, historical, cultural factors and other social development. Based on the above findings, some suggestions are made to improve the eco-efficiency of the water systems in China.

Description: Drought severity and duration are usually modelled independently. However, these two characteristics are known to be related. To model this relationship, a joint distribution of drought severity and duration using a bivariate copula model is proposed and applied to daily rainfall data (1976–2007) of 30 rain gauge stations in Peninsular Malaysia. The drought characteristics are classified using the standardized precipitation index (SPI) and their univariate marginal distributions are further identified by fitting exponential, gamma, generalized extreme value, generalized gamma, generalized logistics, generalized pareto, gumbel max, gumbel min, log-logistic, log-pearson3, log-normal, normal, pearson 5, pearson 6 and weibull distributions. The three-parameter log-normal distribution is identified as the best fitting distribution for drought severity while the generalized pareto distribution is determined as the most appropriate distribution for drought duration with respect to the application of the Anderson-Darling procedure. The dependency among the drought properties is analysed using Kendall’s τ method. The maximum likelihood estimation of the univariate marginal distributions and the maximisation of the bivariate likelihood are employed to compute the Akaike Information Criterion (AIC) values in verifying the best fitting copula distribution. The Galambos distribution is recognised as the most appropriate copula distribution for describing the relationship between drought severity and duration. The conditional drought probability and drought return period are further described to explain the drought properties comprehensively. The probabilities of drought occurrences under certain circumstances with a specific seriousness or duration can be determined in order to verify the possibility of drought episodes. The return period of a recurrent drought has also been investigated to identify the time-interval for repeated drought occurrences under similar situation.

Description: Model-supported real-time flood control requires the development of effective and efficient hydraulic models. As large numbers of iterations are to be executed in optimization procedures, the hydraulic model needs to be computationally efficient. At the same time, it is also required to generate high-accuracy results. Therefore, an identification and calibration procedure was developed for the purpose of having this conceptual model built up and calibrated based on a limited number of simulations with a more detailed full hydrodynamic model. The performance of the conceptual model was evaluated for historical events under different regulation conditions. Robustness test results show close agreement, with Nash-Sutcliffe Efficiency values higher than 0.90. In addition, it is found that the conceptual model is capable of accomplishing simulation of historical flood events within few seconds. That is much faster than the detailed full hydrodynamic model, which enables the conceptual model to be applied for real-time flood control.

Description: In this study, the performance of M5 model tree and conventional method for converting pan evaporation data (E p ) to reference evapotranspiration (ET 0 ) were assessed in semi-arid regions. Conventional method uses pan coefficient (K p ) as a factor to convert E p to ET 0 . Two common K p equations for pans with dry fetch (Allen et al. 1998 ; Abdel-Wahed and Snyder in J Irrig Drain Eng 134(4):425–429, 2008 ) were considered for the comparison. The values of ET 0 derived using these three methods were compared to those estimated using the reference FAO Penmane Monteith (FAO-PM) method under semi-arid conditions of the Khuzestan plain (Southwest Iran). The results showed that the M5 model is the best one to estimate ET 0 over test sites (0.5 mm d −1 of root mean square error (RMSE) and 0.98 of coefficient of determination ( R 2 ). Conversely, the performance of the two K p equations was poor.

Description: Infiltration is the only way water enters soil on the cultivated slopes of the China’s Loess Plateau, so infiltration plays an important role in conserving soil moisture. The objective of this study was to investigate how a soil wetting front created by simulated rainfall migrated in soil with different types of surface roughness. The three types of soil surface treatments studied included surfaces of smooth, medium rough and rough soil. The results showed that, 1) compared with a smooth surface texture, medium rough and rough surface textures have a higher infiltration capacity; 2) the infiltration rate gradually decreases as the wetting front deepens and the rate tends stabilize over time. This change could be described by a logarithmic function; 3) at the early stage of rainfall, the wetting front of medium rough and rough surface textures varied greatly, while the variability of the wetting front decreases markedly after the infiltration rate stabilizes; 4) with increasing depth of the wetting front, the similarity between the wetting front and soil surface profile decreased significantly for the medium rough and rough surface textures. These results indicate that the process of infiltration on cultivated slopes on the Loess Plateau changed from a non-uniform pattern to a uniform pattern as time passed during a rainfall event. Overall, soils with rougher soil surfaces experienced a larger effect of roughness on the process of infiltration.

Description: Optimum reservoir operation is a challenging problem in water resources systems. In this paper, Intelligent Water Drops (IWD) algorithm is applied in a reservoir operation problem. IWD is a population based algorithm and is initially proposed for solving combinatorial problems. The algorithm mimics the dynamics of river system and the behavior of water drops in the rivers. For this purpose data from Dez reservoir, located in southwestern Iran, has been used to examine the performance of the model. Moreover, due to similarities between IWD and the Ant Colony Optimization (ACO) algorithms, the results are compared with those of the ACO algorithm. Comparison of the results shows that while the IWD algorithm finds relatively better solutions, it is able to overcome the computational time consumption deficiencies inherited in the ACO methods. This is very important in large models with too many decision variables where run time becomes a limiting factor for optimization model applications.

Description: Understanding temporal variability in water quality in the Three Gorges Reservoir (TGR) is crucial for evaluating environmental effects of damming and protecting China’s largest freshwater resource. This study examined water quality changes in the main channel of the Yangtze River after dam completion as well as its relationship with water level fluctuation (WLF), controlled by annual impoundment operations and conditioned by flooding. Finally, the mass balance budget and integrative water quality indexing (WQI) methods were applied to elucidate the status of overall water quality since dam completion. Results showed that TGR outlet water (Yichang) exhibited higher pH and COD Mn values and lower concentrations of dissolved oxygen (DO) and ammonia nitrogen (NH 3 -N) than inlet water (Zhutuo). Temporal variations in water quality parameters displayed similar trends for the outlet and inlet. Water quality parameters all showed negative correlations to water level, revealing the different effects of damming on water quality. It was estimated that reservoir impoundment led to a DO depletion of 1495.5 (±1482.0) × 10 3 tons/yr and a COD Mn increase of 564.0 (±405.0) × 10 3 tons/yr, likely deriving from various internal pollutant loads from the WLF zone and tributary watersheds. According to WQI, TGR water quality remained at healthy levels. However, WQI linear regression showed that water quality at the outlet significantly decreased over time, indicating that the construction of the Three Gorges Dam generally caused water quality deterioration. Further investigation is required to determine the spatial distribution of point and non-point pollution sources and to identify major factors that influence TGR water quality.

Description: Concern continues to grow over unreliable water access at the household level in many developing countries. A contingent valuation survey was designed to elicit willingness-to-pay for safe and reliable drinking water in León, Nicaragua. In addition, split-sample treatments were used to investigate preferences for two forms of service governance: the current, centralized water supplier and a decentralized service implemented at the municipal level. Results show that households are willing to pay a substantial increase in their water bills for reliable water supply. Findings also indicate that households hold greater confidence in the current, centralized provider rather than a localized service based on several characteristics such as overall service, awareness of water issues, interest in solving water problems, capacity, accountability, and potential investment.

Description: 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.

Description: 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.

Description: 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.

Description: 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.

Description: 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.

Description: 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.

Description: 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.

Description: 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.

Description: 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 .

Description: The western part of the Argentera–Mercantour massif (French Alps) hosts very large currently active landslides responsible of many disorders and risks to the highly touristic valleys of the Mercantour National Park and skiing resorts. A regional scale mapping of gravitational deformations has been compared to the main geo-structures of the massif. A relative chronology of the events has been established and locally compared to absolute 10 Be dating obtained from previous studies. Two types of large slope destabilisations were identified as follows: deep-seated landslides (DSL) that correspond to rock volumes bounded by a failure surface, and deep-seated gravitational slope deformations (DSGSD) defined as large sagging zones including gravitation landforms such as trenches and scarps or counterscarps. Gravitational landforms are mainly collinear to major N140°E and N020°E tectonic faults, and the most developed DSGSD are located in areas where the slope direction is comparable to the orientation of faults. DSL are mostly included within DSGSD zones and located at the slopes foot. Most of DSL followed a similar failure evolution process according to postglacial over steepened topographies and resulting from a progressive failure growing from the foot to the top of the DSGSD that lasts over a 10 ky time period. This massif-scale approach shows that large-scale DSGSD had a peak of activity from the end of the last deglaciation, to approximately 7000 years bp . Both morphologic and tectonic controls can be invoked to explain the gravitational behaviour of the massif slopes.

Description: This study focused on the landslide case at Su-Hua Highway 115.9k, Taiwan. A preliminary investigation was conducted on geomorphologic features change and landslide mechanisms using digital elevation models, geographical maps, and remote sensing images at different times in conjunction with geological surveys and analysis results. Using the results of geological surveys and physical model experiments, we constructed a discrete element method to simulate the process of landslide movement. The results revealed deformation in the metamorphic rock slopes upstream of 115.9k. The slopes around the erosion gully upstream presented visible slope toes cutting and tension cracks at the crest as well as unstable rock masses. According to the results of numerical simulation for typhoon Megi event, intense rains could induce slippage in the rock debris/masses in the source area, initially at a speed of 5–20 m/s. Subsequently, steeper terrain could cause the rock debris/masses to accelerate to form a high-speed (〉30 m/s) debris slide quickly moving downstream to form an alluvial fan downstream by the sea.

Description: Waterlogging and secondary salinization have become a serious problem in the canal irrigated areas of arid and semi–arid regions worldwide. In this study, a unique and simple technique was evolved in which a linear programming (LP) optimization model was first developed that allocates available land and water resources in order to maximize net annual returns by mitigating the waterlogging problems. A finite–difference two–dimensional simulation model was then used to evaluate the long–term impacts of various water management strategies on the groundwater table with the optimal land and water use parameters which were obtained through the optimization model. The model was used to combat the waterlogging and salinity problem of an area located in Haryana State of India. The calibration, validation, sensitivity analysis, and error analysis of the model was performed before it was used to study the impact of various water management scenarios on the long-term groundwater level. Based on the model results a change in cropping pattern with reduced rice area is suggested. Groundwater withdrawal should be increased by 1–7 % in the various nodes. It is concluded from the analysis of various scenarios that implementing multiple approaches simultaneously are more effective in controlling waterlogging problems as compared to individual interventions.

Description: Groundwater overexploitation is threatening our ecosystems and even the life of future generations. Once happens, elimination of the bad influence will be a long-term process. It should be a feasible approach to take the environmental recovery as a whole by the way of the groundwater management. A case study of water resources management in Huaibei city, within semiarid region of north Anhui province, China, was illustrated, especially on the issues of groundwater over-extraction drawdown funnel recovery. Taking into account the water demand for satisfying the urban development in the next 15 years, three target years of water resources planning were postulated as the present (2005), the short-term (2010) and the long-term (2020), respectively. Four hydrological years: wet year, mean year, dry year and extremely dry year, were also defined by the rainfall data for many years. A groundwater management model which could deal with twelve possible scenarios (3 target years of water resources planning ×4 hydrological years) was established based on simulation and optimization. The groundwater management model could optimize the strategies of water resources development, integrate various kinds of water sources, e.g. groundwater, surface water and additive water sources, and meet the water demand for the urban development within an area of Huaibei city. Importantly, in accordance with the groundwater management model solutions, the issues of groundwater over-extraction drawdown funnel, which has formed within the Huaibei downtown area for many years and lead to some environmental and social problems, would be solved over the whole planning period.

Description: This study discusses the effects of water abstractions from two alternative sources on the available water volume around Lake Naivasha, Kenya: the lake itself and a connected aquifer. An estimation of the water abstraction pattern for the period 1999–2010 is made and its effect on the available water volume in Lake Naivasha and its connected aquifer is evaluated using a simple water balance modeling approach. This study shows that accurate estimates of annual volume changes of Lake Naivasha can be made using a simple monthly water balance approach that takes into account the exchange of water between the lake and its connected aquifer. The amount of water that is used for irrigation in the area around Lake Naivasha has a substantial adverse effect on the availability of water. Simulation results of our simple water balance model suggests that abstractions from groundwater affect the lake volume less than direct abstractions from the lake. Groundwater volumes, in contrast, are much more affected by groundwater abstractions and therefore lead to much lower groundwater levels. Moreover, when groundwater is used instead of surface water, evaporation losses from the lake are potentially higher due to a larger lake surface area. If that would be the case then the overall water availability in the area is more strongly affected by the abstraction of groundwater than by the abstraction of surface water. Therefore water managers should be cautious when using lake levels as the only indicator of water availability for restricting water abstractions.

Description: This paper considers the retail water provider’s purchasing decision of a portfolio of permanent contracts from wholesalers with multiple volatile water sources. We consider the reliability of two contract types: (1) fixed annual quantities, and (2) an inflow harvest function with storage. Our four-reservoir case in Sydney (Australia) has cross-correlated inflow data. To accommodate multi-reservoir cross-correlation we adapt Portfolio Theory from finance to lognormal reservoir inflows, re-framing traditional storage theory from the wholesaler’s optimal operating policy to the retailer’s optimal purchasing policy. We find that Reliability improves with access to a source pool (cf. fixed quantities from separate sources), demonstrating the ‘insurance effect’, and the portfolio that minimises lognormal variance also minimises harvest (and thus environmental impact). Reform direction in Australian (and other international) water markets is towards multi-provider vertical disintegration, which may reduce pool opportunities and negate the insurance effect. We consider diminishing reliability returns as reservoir harvesting increases, and conclude a retail portfolio of permanent contracts from reservoirs, plus short-term contracts from alternative sources (either independently or negatively cross-correlated) efficiently secures high reliability. The challenge in incomplete water markets remains in encouraging and sustaining supply diversification that may only be needed aperiodically during extreme droughts.

Description: The initiation of loess landslides is a common engineering problem during the construction of the expressway or other engineering works in the Loess Plateau of China. The engineers and researchers should devote themselves to the prevention of the initiation of loess landslides. This study focused on a loess landslide which was induced during the construction of an expressway in Shanxi Province of China. The stabilities of the loess hillside slope before and after excavation were analyzed using limit equilibrium analysis method and the strength reduction finite element method, respectively. The analysis results indicated that the loess hillside slope, before excavation, was stable under both natural state and rainfall conditions. The collapse of the loess hillside slope, or the initiation of loess landslides, after having been excavated, was induced by excavation and rainfall. The integrated stabilization method including four parts was used to stabilize the loess landslide. The four parts were a reinforced concrete piles row, a rubble concrete retaining wall, alteration of slope geometry, and interception and drainage of water. The initiation of the loess landslide might be evitable if it was given enough attention before excavation; thus, the problem of loess landslides should be paid big attention during the survey and design of the engineering works, not only during the construction.

Description: Earthquakes in mountainous areas may produce many landslides that involve abundant snow, but few observations have been made of these hazardous phenomena. The 12 March 2011 north Nagano Prefecture earthquake (M JMA 6.7) occurred in a mountainous part of Japan that typically has an annual snow cover of more than 2 m, and it induced many snowy landslides. Some of these traveled relatively long distances. We examined the snowy Tatsunokuchi landslide to reconstruct the landsliding processes over deep snow. We infer that the Tatsunokuchi landslide occurred by collapse of a rock debris mass of 5 × 10 4  m 3 that plunged into the abundant snow, forming a mixture of snow and rock debris, which then traveled on top of the snow. Later, the displaced mass included a large amount of snow which was pushed forward at the front and to the sides. The velocity of the landslide was estimated to be approximately 14 m/s. It appears that the displaced mass, having only a small proportion of rock debris, had a low enough density to travel easily on top of the snow. Our observations suggest that there was much liquid water at the base of the displaced mass shortly after the event. Our results suggest that landslides may damage wider areas than expected if they travel over deep snow.

Description: 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.

Description: 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.

Description: 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.”

Description: 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.

Description: The paper is the introduction to the special issue Water Engineering and Management in a Changing Environment which presents a set of the most innovative contributions at the EWRA Symposium, held in Catania, Italy on 2011.

Description: The Soil Conservation Service Curve Number (SCS-CN) method is widely used for predicting direct runoff volume for a given rainfall event. However, previous results indicated that when the CN value is determined from measured rainfall-runoff data in a natural watershed it is not possible to attribute a single CN value to the watershed, but actually the calculated CN values vary systematically with the rainfall depth. In a previous study, the authors investigated the hypothesis that the observed correlation between the calculated CN value and the rainfall depth in a watershed reflects the effect of the inevitable presence of soil-cover complex spatial variability along watersheds. In this study, a method to determine SCS-CN parameter values from rainfall-runoff data in heterogeneous watersheds is proposed. This method exploits the observed correlation between the calculated CN values and the rainfall depths in order to identify the spatial distribution of CN values along the watershed taking in to account the specific characteristics of the watershed. The proposed method utilizes the available rainfall-runoff data, remote sensing data and GIS techniques in order to provide information on spatial watershed characteristics that drive hydrological behavior. Furthermore, it allows the estimation of CN values for specific soil-land cover complexes in more complex watersheds. The proposed method was tested in a small experimental watershed in Greece. The watershed is equipped with a dense hydro-meteorological network, which together with a detailed land cover and soil survey using remote sensing and GIS techniques provided the detailed data required for this analysis.

Description: This paper presents a study for finding the optimal management plan of an overexploited aquifer under global climate change. The study area is the aquifer of the basin of Lake Karla, located in the eastern part of Thessaly in Greece. An optimization method has been used to evaluate the optimum volume of water that can be extracted from the aquifer and the optimum position of the wells with the objective of water table rise to a desirable sustainable level, taking into consideration the climate change forcing. The modelling system consists of a series of interlinked models: a hydrological, a lake-aquifer, a reservoir operation, a groundwater, and an optimization model. The climate change forcing on precipitation and temperature has been evaluated using the outputs of Canadian Centre for Climate Model Analysis General Circulation Model (CGCMa2) and a hybrid downscaling method which combines a multiple regression (MLR) model and a timeseries model for two socioeconomic emissions scenarios. The results of this study show that climate change plays an important role, as it affects the optimum volume of the extracted groundwater and the position of the irrigation wells.

Description: Regional frequency analysis is a useful tool for accurate estimation of precipitation quantiles than at-site frequency analysis, especially in the case of regions with a short rainfall time series. The use of meteorological information, combined with rainfall data analysis, could improve the selection of homogeneous regions. Starting from 1958, 198 meteorological configurations, related to extreme events, have been identified throughout the national territory of Italy. The reanalyzed meteorological data of the 40 Year Re-analysis Archive (ERA-40) of the European Centre for Medium-Range Weather Forecast (ECMWF) have been analyzed to identify homogeneous regions with respect to the Convective Available Potential Energy (CAPE), the Q vector Divergence (QD) and the Vertically Integrated Moisture Flux (VIMF). The latter index appears to be the better candidate for finding regional homogeneity inside areas where high frequency values of CAPE or QD are present. The paper presents an application based on the delimitation of homogeneous regions using climatic indexes for the island of Sicily. By applying the proposed methodology, seven homogeneous areas over Sicily were found. The consistency of the final results has been validated by using a coupled approach based on the Valuation of Floods in Italy procedure (VAPI) and on the heterogeneity test of Hosking and Wallis (Water Resour Res 29:271–281, 1993 , 1997 ).

Description: 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.

Description: 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.

Description: 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.

Description: 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 km 3 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 km 3 ) 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 km 3 ; a similar mass may threaten the town of Franz Josef.

Description: Assessing in situ microbial abilities of soils to degrade pesticides is of great interest giving insight in soil filtering capability, which is a key ecosystem function limiting pollution of groundwater. Quantification of pesticide-degrading gene expression by reverse transcription quantitative PCR (RT-qPCR) was tested as a suitable indicator to monitor pesticide biodegradation performances in soil. RNA extraction protocol was optimized to enhance the yield and quality of RNA recovered from soil samples to perform RT-qPCR assays. As a model, the activity of atrazine-degrading communities was monitored using RT-qPCRs to estimate the level of expression of atzD in five agricultural soils showing different atrazine mineralization abilities. Interestingly, the relative abundance of atzD mRNA copy numbers was positively correlated to the maximum rate and to the maximal amount of atrazine mineralized. Our findings indicate that the quantification of pesticide-degrading gene expression may be suitable to assess biodegradation performance in soil and monitor natural attenuation of pesticide.

Description: This unique study describes how Aspergillus japonicus , Penicillium brocae and Purpureocillium lilacinum , three novel isolates of our laboratory from heavily plastics-contaminated soil completely utilized the plasticizer di(2-ethylhexyl)phthalate (DEHP) bound to PVC blood storage bags (BB) in simple basal salt medium (BSM) by static submerged growth (28 °C). Initial quantification as well as percentage utilization of DEHP blended to BB were estimated periodically by extracting it into n -hexane. A two-stage cultivation strategy was employed for the complete mycoremediation of DEHP from BB in situ. During the first growth stage, about two-third parts of total (33.5 % w/w) DEHP bound to BB were utilized in two weeks, accompanied by increased fungal biomass (~0.15–0.32 g per g BB) and sharp declining (to ~3) of initial pH (7.2). At this stagnant growth state (low pH), spent medium was replaced by fresh BSM (pH, 7.2), and thus in the second stage the remaining DEHP (one-third) in BB was utilized completely. The ditches and furrows seen from the topology of the BB as seen by the 3D AFM image further confirmed the bioremediation of DEHP physically bound to BB in situ. Of the three mycelial fungi employed, P. lilacinum independently showed highest efficiency for the complete utilization of DEHP bound to BB, whose activity was comparable to that of the consortium comprising all the three fungi described herein. To sum up, the two-stage cultivation strategy demonstrated in this study shows that a batch process would efficiently remediate the phthalic acid esters blended in plastics on a large scale, and thus it offers potentials for the management of plastics wastes.

Description: A comprehensive study on the effects of different carbon sources during the bacterial enrichment on the removal performances of benzene, toluene, ethylbenzene, and xylenes (BTEX) compounds when present as a mixture was conducted. Batch BTEX removal kinetic experiments were performed using cultures enriched with individual BTEX compounds or BTEX as a mixture or benzoate alone or benzoate–BTEX mixture. An integrated Monod-type non-linear model was developed and a ratio between maximum growth rate ( μ max ) and half saturation constant (K s ) was used to fit the non-linear model. A higher μ max /K s indicates a higher affinity to degrade BTEX compounds. Complete removal of BTEX mixture was observed by all the enriched cultures; however, the removal rates for individual compounds varied. Degradation rate and the type of removal kinetics were found to be dependent on the type of carbon source during the enrichment. Cultures enriched on toluene and those enriched on BTEX mixture were found to have the greatest μ max /K s and cultures enriched on benzoate had the least μ max /K s . Removal performances of the cultures enriched on all different carbon sources, including the ones enriched on benzoate or benzoate–BTEX mixture were also improved during a second exposure to BTEX. A molecular analysis showed that after each exposure to the BTEX mixture, the cultures enriched on benzoate and those enriched on benzoate–BTEX mixture had increased similarities to the culture enriched on BTEX mixture.

Description: 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.

Description: 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.

Description: Each single phase of a water supply network, from water adduction to distribution to end-users, is exposed to many diverse potential sources of intentional contamination (or malicious attacks). One of the most dangerous threats is a backflow attack that occurs when a pump system, easily available on the market, is utilized to overcome the pressure gradient of network pipes. In this work, a simple backflow attack with cyanide being introduced into a real-water system is modeled and the most dangerous introduction points for a contaminant incident are defined. Moreover, the network vulnerability has been analyzed by computing the lethal dose of cyanide ingested by users and the total length of the contaminated water system. Eventually the effects of network partitioning and district isolation to protect water supply systems have been investigated. The results show how district closing - by network sectorization techniques used to improve leakage search and reduction - can significantly decrease contaminant diffusion and protect part of the users from cyanide uptake. Network sectorization can also reduce the risk of simple malicious attacks because several introduction points are necessary to have a massive negative impact on the network. Simulation results also show that in some cases water network partitioning may worsen water network protection and further studies are necessary to design water districts for network security and safety.

Description: This article examines available methods for assessing all types of drought costs, including both damage costs and costs arising from adopting policy measures to encourage mitigation of, and adaptation to, droughts. It first discusses damage costs, distinguishing between direct, indirect and non-market costs. Then it examines the suitability of existing methods for estimating drought costs in different economic sectors, their underlying theoretical assumptions, complementarity between different methods, and conditions relevant for their application. The latter include precision, ability to deal with future climate change risks, data needs and availability, and required financial and human resources. The article further considers potential policies for drought mitigation and adaptation and different cost types associated with them. It ends with providing recommendations for good practices regarding the use of methods as well as drought mitigation and adaptation policies.

Description: Dependency of reservoir operation on the climate variation occurs especially in regions, where agricultural demand has a significant share of the total water demands. The variability between demands that are based on annual climate conditions may be larger than the uncertainty associated with other explanatory variables in long-term operation of an irrigation dam. This paper proposed a rule curves to the water managers of the Zayandeh-rud reservoir in Iran in long-lead reservoir operation. A regional optimal allocation of water among different crops and irrigation units is developed. The optimal allocation model is coupled with a reservoir operating model, which is developed based on the certain hedging that deals with the available water and the water demands mutually. This coupled model is able to activate restrictions on allocating water to agricultural demands considering variation of inflow to the reservoir, variation of demands and the economic value of allocating water among different crops and irrigation units. The resulted rule curve is presented with a number of tables for more details and accuracy and a simple curve, which is more useful for operational purpose.

Description: A genetically engineered microorganism (GEM) capable of simultaneously degrading organophosphate and organochlorine pesticides was constructed for the first time by display of organophosphorus hydrolase (OPH) on the cell surface of a hexachlorocyclohexane (HCH)-degrading Sphingobium japonicum UT26. The GEM could potentially be used for removing the two classes of pesticides that may be present in mixtures at contaminated sites. A surface anchor system derived from the truncated ice nucleation protein (INPNC) from Pseudomonas syringae was used to target OPH onto the cell surface of UT26, reducing the potential substrate uptake limitation. The surface localization of INPNC–OPH fusion was verified by cell fractionation, western blot, proteinase accessibility, and immunofluorescence microscopy. Furthermore, the functionality of the surface-exposed OPH was demonstrated by OPH activity assays. Surface display of INPNC–OPH fusion (82 kDa) neither inhibited cell growth nor affected cell viability. The engineered UT26 could degrade parathion as well as γ-HCH rapidly in minimal salt medium. The removal of parathion and γ-HCH by engineered UT26 in sterile and non-sterile soil was also studied. In both soil samples, a mixture of parathion (100 mg kg −1 ) and γ-HCH (10 mg kg −1 ) could be degraded completely within 15 days. Soil treatment results indicated that the engineered UT26 is a promising multifunctional bacterium that could be used for the bioremediation of multiple pesticide-contaminated environments.

Description: Stimulation of native microbial populations in soil by the addition of small amounts of secondary carbon sources (cosubstrates) and its effect on the degradation and theoretical mineralization of DDT [l,l,l-trichloro-2,2-bis( p -chlorophenyl)ethane] and its main metabolites, DDD and DDE, were evaluated. Microbial activity in soil polluted with DDT, DDE and DDD was increased by the presence of phenol, hexane and toluene as cosubstrates. The consumption of DDT was increased from 23 % in a control (without cosubstrate) to 67, 59 and 56 % in the presence of phenol, hexane and toluene, respectively. DDE was completely removed in all cases, and DDD removal was enhanced from 67 % in the control to ~86 % with all substrates tested, except for acetic acid and glucose substrates. In the latter cases, DDD removal was either inhibited or unchanged from the control. The optimal amount of added cosubstrate was observed to be between 0.64 and 2.6 mg C $ {\text{g}}^{ - 1}_{\text{dry soil}} $ . The CO 2 produced was higher than the theoretical amount for complete cosubstrate mineralization indicating possible mineralization of DDT and its metabolites. Bacterial communities were evaluated by denaturing gradient gel electrophoresis, which indicated that native soil and the untreated control presented a low bacterial diversity. The detected bacteria were related to soil microorganisms and microorganisms with known biodegradative potential. In the presence of toluene a bacterium related to Azoarcus , a genus that includes species capable of growing at the expense of aromatic compounds such as toluene and halobenzoates under denitrifying conditions, was detected.

Description: Because benzene, toluene, ethylbenzene, and xylenes (BTEX) and ethanol are important contaminants present in Brazilian gasoline, it is essential to develop technology that can be used in the bioremediation of gasoline-contaminated aquifers. This paper evaluates the performance of a horizontal-flow anaerobic immobilized biomass (HAIB) reactor fed with water containing gasoline constituents under denitrifying conditions. Two HAIB reactors filled with polyurethane foam matrices (5 mm cubes, 23 kg/m 3 density and 95 % porosity) for biomass attachment were assayed. The reactor fed with synthetic substrate containing protein, carbohydrates, sodium bicarbonate and BTEX solution in ethanol, at an Hydraulic retention time (HRT) of 13.5 h, presented hydrocarbon removal efficiencies of 99 % at the following initial concentrations: benzene 6.7 mg/L, toluene 4.9 mg/L, m -xylene and p -xylene 7.2 mg/L, ethylbenzene 3.7 mg/L, and nitrate 60 mg N/L. The HAIB reactor fed with gasoline-contaminated water at an HRT of 20 h showed hydrocarbon removal efficiencies of 96 % at the following initial concentrations: benzene, 4.9 mg/L; toluene, 7.2 mg/L; m -xylene, 3.7 mg/L; and nitrate 400 mg N/L. Microbiological observations along the length of the HAIB reactor fed with gasoline-contaminated water confirmed that in the first segment of the reactor, denitrifying metabolism predominated, whereas from the first sampling port on, the metabolism observed was predominantly methanogenic.

Description: Burkholderia sp. C3, an efficient polycyclic aromatic hydrocarbon degrader, can utilize nine of the ten N -methylcarbamate insecticides including carbaryl as a sole source of carbon. Rapid hydrolysis of carbaryl in C3 is followed by slow catabolism of the resulting 1-naphthol. This study focused on metabolomes and proteomes in C3 cells utilizing carbaryl in comparison to those using glucose or nutrient broth. Sixty of the 867 detected proteins were involved in primary metabolism, adaptive sensing and regulation, transport, stress response, and detoxification. Among the 41 proteins expressed in response to carbaryl were formate dehydrogenase, aldehyde-alcohol dehydrogenase and ethanolamine utilization protein involved in one carbon metabolism. Acetate kinase and phasin were 2 of the 19 proteins that were not detected in carbaryl-supported C3 cells, but detected in glucose-supported C3 cells. Down-production of phasin and polyhydroxyalkanoates in carbaryl-supported C3 cells suggests insufficient carbon sources and lower levels of primary metabolites to maintain an ordinary level of metabolism. Differential metabolomes (~196 identified polar metabolites) showed up-production of metabolites in pentose phosphate pathways and metabolisms of cysteine, cystine and some other amino acids, disaccharides and nicotinate, in contract to down-production of most of the other amino acids and hexoses. The proteomic and metabolomic analyses showed that carbaryl-supported C3 cells experienced strong toxic effects, oxidative stresses, DNA/RNA damages and carbon nutrient deficiency.

Description: Species of the genus Variovorax are often isolated from nitrile or amide-containing organic compound-contaminated soil. However, there have been few biological characterizations of Variovorax and their contaminant-degrading enzymes. Previously, we reported a new soil isolate, Variovorax boronicumulans CGMCC 4969, and its nitrile hydratase that transforms the neonicotinoid insecticide thiacloprid into an amide metabolite. In this study, we showed that CGMCC 4969 is able to degrade acrylamide, a neurotoxicant and carcinogen in animals, during cell growth in a mineral salt medium as well as in its resting state. Resting cells rapidly hydrolyzed 600 mg/L acrylamide to acrylic acid with a half-life of 2.5 min. In in vitro tests, CGMCC 4969 showed plant growth-promoting properties; it produced a siderophore, ammonia, hydrogen cyanide, and the phytohormone salicylic acid. Interestingly, in soil inoculated with this strain, 200 mg/L acrylamide was completely degraded in 4 days. Gene cloning and overexpression in the Escherichia coli strain Rosetta (DE3) pLysS resulted in the production of an aliphatic amidase of 345 amino acids that hydrolyzed acrylamide into acrylic acid. The amidase contained a conserved catalytic triad, Glu59, Lys 134, and Cys166, and an “MRHGDISSS” amino acid sequence at the N-terminal region. Variovorax boronicumulans CGMCC 4969, which is able to use acrylamide for cell growth and rapidly degrade acrylamide in soil, shows promising plant growth-promoting properties. As such, it has the potential to be developed into an effective Bioaugmentation strategy to promote growth of field crops in acrylamide-contaminated soil.

Description: Organic and metallic pollutants are ubiquitous in the environment. Many metals are reported to be toxic to microorganisms and to inhibit biodegradation. The effect of the metals iron, copper and silver on the metabolism of Labrys portucalensis F11 and on fluorobenzene (FB) biodegradation was examined. The results indicate that the addition of 1 mM of Fe 2+ to the culture medium has a positive effect on bacterial growth and has no impact in the biodegradation of 1 and 2 mM of FB. The presence of 1 mM of Cu 2+ was found to strongly inhibit the growth of F11 cultures and to reduce the biodegradation of 1 and 2 mM of FB to ca. 50 %, with 80 % of stoichiometrically expected fluoride released. In the experiments with resting cells, the FB degraded (from 2 mM supplied) was reduced ca. 20 % whereas the fluoride released was reduced to 45 % of that stoichiometrically expected. Ag + was the most potent inhibitor of FB degradation. In experiments with growing cells, the addition of 1 mM of Ag + to the culture medium containing 1 and 2 mM of FB resulted in no fluoride release, whereas FB degradation was only one third of that observed in control cultures. In the experiments with resting cells, the addition of Ag + resulted in 25 % reduction in substrate degradation and fluoride release was only 20 % of that stoichiometrically expected. The accumulation of catechol and 4-fluorocatechol in cultures supplemented with Cu 2+ or Ag + suggest inhibition of the key enzyme of FB metabolism—catechol 1,2-dioxygenase.

Description: In the present study, the influence of kaolinite and goethite on microbial degradation of methyl parathion was investigated. We observed that the biodegradation process was improved by kaolinite and depressed by goethite. Calorimetric data further showed that the metabolic activities of degrading cells ( Pseudomonas putida ) were enhanced by the presence of kaolinite and depressed by the presence of goethite. A semipermeable membrane experiment was performed and results supported the above observations: the promotive effect of kaolinite and the inhibition of goethite for microbial degradation was not found when the bacteria was enclosed by semipermeable membrane and had no direct contact with these minerals, suggesting the important function of the contact of cellular surfaces with mineral particles. The relative larger particles of kaolinite were loosely attached to the bacteria. This attachment made the cells easy to use the sorbed substrate and then stimulated biodegradation. For goethite, small particles were tightly bound to bacterial cells and limited the acquisition of substrate and nutrients, thereby inhibiting biodegradation. These results indicated that interfacial interaction between bacterial cells and minerals significantly affected the biodegradation of pesticides.

Description: Although 4- tert -butylphenol (4- t -BP) is a serious aquatic pollutant, its biodegradation in aquatic environments has not been well documented. In this study, 4- t -BP was obviously and repeatedly removed from water from four different environments in the presence of Spirodela polyrrhiza , giant duckweed, but 4- t -BP persisted in the environmental waters in the absence of S. polyrrhiza . Also, 4- t -BP was not removed from autoclaved pond water with sterilized S. polyrrhiza . These results suggest that the 4- t -BP removal from the environmental waters was caused by biodegradation stimulated by the presence of S. polyrrhiza rather than by uptake by the plant. Moreover, Sphingobium fuliginis OMI capable of utilizing 4- t -BP as a sole carbon and energy source was isolated from the S. polyrrhiza rhizosphere. Strain OMI degraded 4- t -BP via a meta -cleavage pathway, and also degraded a broad range of alkylphenols with linear or branched alkyl side chains containing two to nine carbon atoms. Root exudates of S. polyrrhiza stimulated 4- t -BP degradation and cell growth of strain OMI. Thus, the stimulating effects of S. polyrrhiza root exudates on 4- t -BP-degrading bacteria might have contributed to 4- t -BP removal in the environmental waters with S. polyrrhiza . These results demonstrate that the S. polyrrhiza –bacteria association may be applicable to the removal of highly persistent 4- t -BP from wastewaters or polluted aquatic environments.

Description: The biodegradation of heptadecane in five sand columns was modeled using a multiplicative Monod approach. Each column contained 1.0 kg of sand and 2 g of heptadecane, and was supplied with an artificial seawater solution containing nutrients at a flow rate that resulted in unsaturated flow through the column. All nutrients were provided in excess with the exception of nitrate whose influent concentration was 0.1, 0.5, 1.0, 2.5, or 5.0 mg N/L. The experiment was run around 912 h until no measurable oxygen consumption or CO 2 production was observed. The residual mass of heptadecane was measured at the end of the experiments and the biodegradation was monitored based on oxygen consumption and CO 2 production. Biodegradation kinetic parameters were estimated by fitting the model to experimental data of oxygen, CO 2 , and residual mass of heptadecane obtained from the two columns having influent nitrate–N concentration of 0.5 and 2.5 mg/L. Noting that the oxygen and CO 2 measurements leveled off at around 450 h, we fitted the model to these data for that range. The estimated parameters fell in within the range reported in the literature. In particular, the half-saturation constant for nitrate utilization,  $ K_{\text{N}} $ , was estimated to be 0.45 mg N/L, and the yield coefficient was found to be 0.15 mg biomass/mg heptadecane. Using these values, the rest of experimental data from the five columns was predicted, and the model agreed with the observations. There were some consistent discrepancies at large times between the model simulation and observed data in the cases with higher nitrate concentration. One plausible explanation for these differences could be limitation of biodegradation by reduction of the heptadecane–water interfacial area in these columns while the model uses a constant interfacial area.

Description: This paper addresses the problem of the localization of contamination sources after deliberate contaminations in drinking water distribution systems (DWDS). The proposed methodology is based on the information given by successive positive readings of sensors. Thus, it is possible to estimate the localization of the contamination sources based on only the first sensor that detected a contamination, and then update the results when more information is available. From the tests performed on a real drinking water distribution system, it was possible to observe that as new sensors detect changes in contaminant concentration, other possible contaminations may be detected and the location of contamination sources may be more restricted. The results achieved for the two set of sensors considered in the study contained the correct locations and the instants of contaminations previously simulated. Two case studies were also analysed to study the effect of the occurrence of false positives. It was concluded that it is not always possible to verify the occurrence of those anomalies and when it is verified, it is not possible to distinguish between a false positive and a false negative. The occurrence of false positives did not affect also the results related with the real detections.

Description: The importance of simulation models to assess the impacts of droughts and the effects of mitigation options on water supply systems is well known. However a common procedure about the exploitation of model results is not established yet. Vulnerability is used to characterize the performance of the system, and it can be a helpful indicator in the evaluation of the most likely failures. In this paper a water allocation model is applied to the water supply system of the upper Tiber Basin (Central Italy) in which both surface waters (rivers, reservoirs) and ground waters (wells, springs) are exploited to feed mainly irrigation and civil users. Drought vulnerability indices are calculated to analyze the performance of the supply system under different climate and management conditions. Water shortage scenarios are simulated as a progressive reduction of mean precipitation, an increase in its standard deviation or a combination of both. The model shows that the safety of the water supply system mainly relies on the reservoirs and that the foreseen increased exploitation of the springs to replace contaminated wells, could be seriously limited by discharge decrease during fall. The vulnerability reduction obtained by a hypothetical augmentation of the storage capacity through additional small reservoirs was positively tested by the model. In conclusion vulnerability indices and synoptic risk maps demonstrated to be useful tools to analyze the model outputs. They provide easy-to-read scenarios to be used in a decision making framework considering negotiating among the main users.

Description: The work presented herein addresses the problem of sensor placement optimization in urban water distribution networks by use of an entropy-based approach, for the purpose of efficient and economically viable waterloss incident detection. The proposed method is applicable to longitudinal rather than spatial sensing, thus to devices such as acoustic, pressure, or flow sensors acting on pipe segments. The method utilizes the maximality, subadditivity and equivocation properties of entropy, coupled with a statistical definition of the probability of sensing within a pipe segment, to assign an entropy metric to each pipe segment and subsequently optimize the location of sensors in the network based on maximizing the total entropy in the network. The method proposed is a greedy-search heuristic.

Description: With the worldwide depletion of groundwater and the intensified use around the world, particularly in many arid and semi-arid regions for irrigation and municipal use, there is no satisfactory approach to groundwater sustainability. The lack of and miss-management of this valuable resource has not only created serious groundwater pollution problems but has created present and/or future water supply problems. This paper does not present a solution, but instead examines economic ideas such as exhaustible resource theory (over exploitation), and optimization methodologies that can incorporate new ideas of groundwater sustainability, population growth constraints, include both short term and long term consequences, and consider multi-objectives. Concepts of groundwater footprint, recharge, and safe yield are discarded as concepts for measuring groundwater sustainability. The concept of developing a sustainability index that could also be used within the context of optimization is introduced. Also the concepts of traditional knowledge are discussed with the emphasis on the use of these methodologies for both developed and developing regions of the world to achieve groundwater sustainability.

Description: Reservoir operation cannot be carried out without due heed to surface water and groundwater resources, since neglecting either will have irreversible consequences. Optimal operation of the Zayandehrood Dam which supplies water into the Zayandehrood River basin in the central plateau of Iran is a case in point which warrants due consideration paid to both dam operation and the climate conditions in the region suffering from a history of successive droughts. The main objective of the present research is to develop operation rules for the Zayandehrood reservoir through a combined perspective of both surface and ground water resources using the fuzzy inference system, and adaptive neuro-fuzzy inference system. The objective is to determine the share of the Zayandehrood reservoir in meeting downstream water demands. For this purpose, the water shortage and the dramatic groundwater drawdown in the Zayandehrood River basin faced with in recent years have been studied in an attempt to develop operation models capable of controlling groundwater drawdown. The models indicate that not only can groundwater drawdown be controlled, but that it is also possible to establish a greater sustainability. Different operation models have been compared in terms of their operation criteria. Results show that the ANFIS model composed of optimal data enjoys a higher sustainability compared to others.

Description: Genetic algorithms (GA) are optimization techniques that are widely used in the design of water distribution networks. One of the main disadvantages of GA is positional bias, which degrades the quality of the solution. In this study, a modified pseudo-genetic algorithm (PGA) is presented. In a PGA, the coding of chromosomes is performed using integer coding; in a traditional GA, binary coding is utilized. Each decision variable is represented by only one gene. This variation entails a series of special characteristics in the definition of mutation and crossover operations. Some benchmark networks have been used to test the suitability of a PGA for designing water distribution networks. More than 50,000 simulations were conducted with different sets of parameters. A statistical analysis of the obtained solutions was also performed. Through this analysis, more suitable values of mutation and crossover probabilities were discovered for each case. The results demonstrate the validity of the method. Optimum solutions are not guaranteed in any heuristic method. Hence, the concept of a “good solution” is introduced. A good solution is a design solution that does not substantially exceed the optimal solution that is obtained from the simulations. This concept may be useful when the computational cost is critical. The main conclusion derived from this study is that a proper combination of population and crossover and mutation probabilities leads to a high probability that good solutions will be obtained.

Description: Calabria is one of the Italian regions mostly affected by mass movements. The case study of a densely populated neighborhood (Ianò) located in the central-western sector of Calabria is presented. The several landslides triggered in February 2010 caused heavy damages to the built area, infrastructures and productions of this neighborhood, and increased the risk for the inhabitants. The results obtained through field surveys, photo interpretation, analyses of rainfall data and of the urban fabric evolution, historical survey on the reports of the damages caused by landslides, have enabled to formulate hypotheses on the potential causes that triggered landslide events and produced severe consequences on the area. These results have revealed that almost all landslides of February 2010 are partial reactivations of pre-existing landslide deposits. Moreover, the analyses have indicated a critical role of cumulative rainfalls over an interval of 15 days. However, the severe damage framework is explained through an unplanned urbanization which took place across the years on an area characterized by a high level of instability per se. Some buildings have been erected in proximity of or within pre-existing landslide scarps; in other cases, buildings have been constructed even inside the landslide bodies.

Description: Public utilities could improve their efficiency by pursuing specific strategies, such as growth, diversification of investments, or serving mainly high densely areas. For example, in the water sector, economies of scope and scale both appear possible, but extant literature does not offer clear or consensual findings. To address this lack of clarity, this article investigates the potential for efficiency improvement in the diverse Italian water sector, which comprises utilities of various sizes, operating in areas with various population densities and organized as mono- or multi-utilities. Technical and financial data from 64 different utilities were collected and then analyzed with a two-stage data envelopment analysis approach to reveal the impacts of different operational and exogenous variables on efficiency, including firm size, the degree of investment diversification, and customer density. The results obtained confirm the existence of all three types of economies (scale, scope and density), albeit with different impacts for each DEA score.

Description: Green roofs are increasingly used as sustainable urban drainage systems due to their retention and detention capacity; however, the impact of green roofs in term of water quality is still a debated issue among researchers. A monitoring programme was carried out at the University of Genoa on a full-scale experimental site to assess the quality of storm water outflows. As for rainfall, the bulk deposition (dry and wet fractions) is collected to evaluate the role of the overall atmospheric deposition in altering storm water quality. The pollutant load observed in the green roof outflow is limited; concentration values for solids and metals are lower than those generally observed in storm water runoff from impervious surfaces. Suspended solids and Chemical Oxygen Demand (COD) are below respectively 10 and 20 mg/l, on average; as for heavy metals, copper and zinc are equal to 30 μg/l on average, while iron is equal to 120 μg/l. The Event Mean Concentration (EMC) statistics of the pollutant loads associated with the rainfall and outflow have been compared and discussed. The observed green roof behaviour as a sink/source of pollutants with respect to the atmospheric deposition is also investigated based on both concentration and mass. Results demonstrate that: green roof behaves as a source with respect to solids, COD and potassium while zinc and mainly copper are retained within the green roof stratigraphy. The resulting mass delivery behaviour reveals that no significant first flush occurs for pollutant constituents irrespective of the hydrologic characteristics and pollutant sources.

Description: Consequence analysis is, together with hazard evaluation, one of the major steps of landslide risk assessment. However, a significant discrepancy exists between the number of published landslide hazard and landslide consequence studies. While various methodologies for regional-scale hazard assessment have been developed during the last decade, studies for estimating and visualising possible landslide consequences are still limited, and those existing are often difficult to apply in practice mainly because of the lack of data on the historical damage or on landslide damage functions. In this paper, an indicator-based GIS-aided methodology is proposed with an application to regional-scale consequence analysis. The index, called Potential Damage Index, allows describing, quantifying, valuing, totalizing and visualising different types of consequences. The method allows estimating the possible damage caused by landslides by combining weighted indicators reflecting the exposure of the elements at risk. Direct (physical injury, and structural and functional damage) and indirect (socio-economic impacts) consequences are individually analysed and subsequently combined to obtain a map of total consequences due to landsliding. Geographic visualisation of the index allows the delineation of the areas exposed to any type of possible impacts that could be combined with a corresponding map displaying landslide probability of occurrence. The method has been successfully applied to analyse the present consequences in the Barcelonnette Basin (South French Alps). These maps contribute to development of adequate land use and evacuation plans, and thus are important tools for local authorities and insurance companies.

Description: This paper describes a new multi-objective evolutionary optimization approach to the simultaneous layout and pipe size design of water distribution systems. Pressure-deficient and topologically infeasible solutions are fully incorporated in the genetic algorithm without recourse to constraint violation penalties or tournaments. The proposed approach is demonstrated by solving three benchmark problems taken from the literature. New optimal layouts and/or new feasible solutions that are cheaper than the best solutions in the literature were found for both branched and looped network configurations. Specifically, a new best solution was generated for each of the above-mentioned benchmark problems. In addition, the case of the looped design of a hitherto branched network in the literature was considered. Detailed results are included that show that the proposed approach achieves good solutions efficiently and consistently.

Description: There is no doubt that groundwater is an important and vital source of water supply in arid and semi-arid areas. Therefore, prediction of groundwater level fluctuations is necessary for planning conjunctive use in these areas. This research was aimed to predict groundwater levels in the Neishaboor plain using N eural N etwork – A uto R egressive e X tra input (NN-ARX) and Static-NN models. The NN-ARX model determines a nonlinear ARX model of a dynamic system by training a hidden layer neural network with the Levenberg-Marquardt algorithm. In this model the current outputs depend not only on the current inputs, but also on the inputs and outputs at the pervious time periods. The available observation wells in the study area were clustered according to their fluctuation behavior using the “Ward” method, which resulted in six areal zones. Then, for each cluster, an observation well was selected as its representative, and for each zone, values of monthly precipitation, temperature and groundwater extraction were estimated. The best input of the Static-NN model was identified using combination of Gamma Test and Genetic Algorithm. Also, Gamma Test is applied to identify the length of the training dataset. The results showed that the NN-ARX model was suitable and more practical. The performance indicators ( R 2  = 0.97, RMSE = 0.03 m, ME = --0.07 m and R 2  = 0.81, RMSE = 0.35 m, ME = 0.60 m, respectively for the best and worst performance of model) reveals the effectiveness of this model. Moreover, these results were compared with the results of a static-NN model using t-test , which showed the superiority of the NN-ARX over the static-NN.

Description: In western Victoria, Australia the water table and lake level in the Glenelg-Hopkins catchment have been declining for the last 15 years, and this is attributed to either the low rainfall over this time and/or a substantial change in land use. Stream flow modelling was carried out using monthly empirical water balance model (modified tanh function together with double mass curve analysis), on 37 stream gauges to assess whether the impact of land use change could be detected by a change in the magnitude of the resulting runoff. The empirical hydrological model was able to distinguish impact of land use change on stream flow from the climatic variables. There were substantial decreases in stream flow in the 1970s–1980s, probably related to increasing livestock densities in the region. Furthermore, the methodology can be a powerful tool to monitor and evaluate the possible impacts of future land use changes. It can be concluded that the use of such empirical hydrological modelling greatly improves the ability to analyse the impact of land use on catchment runoff. The model is a practical tool that can be readily used for identifying and quantifying the effect of landuse changes on catchment for water resource decision-making, which could be hardly possible using the time consuming, data hungry and expensive physical process models available.

Description: Few studies have focused on the relationship between the various causes of groundwater level fluctuations and the seawater intrusion process, due to the complexity of this relationship, being the aim of this paper. Piezometric fluctuations in coastal aquifers are determined by a number of processes and their characterization depends on the complexity of the aquifer stratigraphy, as well as many other hydrodynamic factors. The precipitation regime, tides, wave setup and storm surges, as well as atmospheric pressure are the most relevant of these processes. By means of a series of observations made at an experimental site in south-eastern Spain, this study demonstrates the complexity of water table fluctuations in coastal zones. The study employed two piezometers situated very close to the shoreline, excavated in detritic deposits with highly variable hydraulic conductivity (semi-confined aquifer). Continuous measurements were taken of hydraulic head, tide height, electrical conductivity and water temperature. The study concludes that precipitation has the greatest effect on piezometric level, followed by atmospheric pressure and wave action, while the semi-diurnal and fortnightly tidal cycles caused variations of smaller amplitude in the piezometric logs. All these oscillations affect the position of the fresh water-seawater interface. The attenuation of the tidal amplitude observed at the two monitoring points was lower than the value calculated using analytical solutions, and this is due to the semi-confined nature of the aquifer. The calculated tidal efficiency is around 0.4-0.5, giving a t lag of about 3 h, with a 10–15 min delay between monitoring boreholes, P-II and PI. We also identified that the response of water conductivity and temperature to tidal cycles is not synchronized with the variations in the piezometric level influenced by tidal fluctuations.

Description: The authors propose a measurement method that divides the depth of the soil sample in discrete regions to investigate soil water propagation dynamics using soil impedance measurements. Experiments were conducted on a cylindrical phantom using a clay loam soil sample (60 % clay, 21 % loam and 19 % sand). The resulting impedance changes represent the wetting front (WF) propagation process at the different measurement depths. The measured impedance data is used to A) show graphically the wetting front propagation process, obtain B) a 1st order model, C) an ARX1821 model of the impedance change as a function of the irrigation volume applied and D) estimating changes in water content using a neural network. The results indicate that the proposed measurement technique can be used to detect and predict the movement of liquid trough the soil sample. The neural network permits inferring the water content from impedance and soil-water mixture temperature values. Changes in soil impedance in each segment, due to the water propagating downwards through the soil sample, can be used to study the dynamics of the wetting front, irrigation scheduling and model improvement from physical data.

Description: The paper presents an approach to the modelling of watercourses or their sections according to and in order to determine their suitability for hydropower water use on a large scale. The method is based on a multi-criteria analysis approach which in addition to existing guidelines defines and describes in detail the main stages for model establishment and hydropower suitability analysis. Since hydropower planning stands in direct conflict with other ecological water-related objectives, evaluation of suitability is based on two main criteria, which are supported with the belonging criteria. The first main criterion is based on evaluation of watercourses by their attractiveness for hydropower water use; the second one on evaluation of watercourses according to their ecological state or value. To support proper determination of unknown model parameters (e.g. weights of selected criteria) the paper also presents an upgrade of general multi-criteria analysis process with a calibration stage, which can efficiently upgrade in cases when calibration data is available. The proposed method was tested and discussed on a real case study with three dislocated Slovenian Alpine watercourses, where weights of preselected criteria and some thresholds of performance functions were selected as model variables and calibrated.

Description: Various scientific and technological based solutions such as virtual water trading, desalination, groundwater extraction and wastewater reuse have been proposed and implemented in many parts of Asia and Africa to relieve water scarcity. This paper applies SWOT (strengths, weaknesses, opportunities and threats) analysis to examine the suitability of these alternative water solutions to alleviate water scarcity. SWOT analysis proves to be a useful decision making tool as it provides a qualitative approach to simplify multilayer and interdisciplinary problems. The main input for the SWOT analysis consists of knowledge gathered from seven experts in the field of water and environmental sciences. The results show that compared to other solutions, wastewater reuse offers the most desirable qualities as a viable water solution for sustainable water management in Asia and Africa.

Description: Groundwater withdrawals can reduce aquifer-to-stream flow and induce stream-to-aquifer flow. These effects involve potential threats over surface water and groundwater quantity and quality. As a result, the description of stream-aquifer flow in space and time is of high interest for water managers. In this study, the EauDyssée platform, an integrated groundwater/surface water model is extended to provide the distribution of stream-aquifer flow at the regional scale. The methodology is implemented over long periods (17 years) in the Seine river basin (76 375 km 2 , France) with a 6 481 km long simulated river network. The study scale is compatible with the scale of interest of water authorities, which is often larger than study scales of research projects. Net and gross stream-aquifer exchange flow are computed at the daily time step over the whole river network at a resolution of 1 km. Simulation results highlight that a major proportion of the main stream network (82 %) is supplied by groundwater. Groundwater withdrawals induce a reduction of net aquifer-to-stream flow (−19 %) at the basin scale and flow reversals in the vicinity of pumping locations. Such an integrated model provided at the appropriate regional scale is an essential tool provided to water managers for the implementation of the EU Water Framework Directive.

Description: This paper presents the comparison of two hybrid methodologies for the two-objective (cost and resilience) design of water distribution systems. The first method is a low-level hybrid algorithm (LLHA), in which a main controller (the non-dominated sorting genetic algorithm II, NSGA-II) coordinates various subordinate algorithms. The second method is a high-level hybrid algorithm (HLHA), in which various sub-algorithms collaborate in parallel. Applications to four case studies of increasing complexity enable the performances of the hybrid algorithms to be compared with each other and with the performance of the NSGA-II. In the case study featuring low/intermediate complexity, the hybrid algorithms (especially the HLHA) successfully capture a more diversified Pareto front, although the NSGA-II shows the best convergence. When network complexity increases, instead, the hybrid algorithms (especially the LLHA) turn out to be superior in terms of both convergence and diversity. With respect to both the HLHA and the NSGA-II, the LLHA is capable of detecting the final front in a single run with a lower computation burden. In contrast, the HLHA and the NSGA-II, which are more affected by the initial random seed, require numerous runs with an attempt to reach the definitive Pareto front. On the other hand, a drawback of the LLHA lies in its reduced ability to deal with general problem formulations, i.e., those not relating to water distribution optimal design.

Description: Intensification of heavy precipitation as discussed in climate change studies has become a public concern, but it has not yet been examined well with observed data, particularly with data at short temporal scale like hourly and sub-hourly data. The original data set was retrieved by using an automated recovery approach. We chose four stations, namely, Vercelli (since 1927), Bra (since 1933), Lombriasco (since 1939) and Pallanza (since 1950) which are located in the northwest of Italy. We assessed trends for durations from 5 min to 12 h in seasonal, annual maxima, and number and magnitude of exceedances of the 95th percentile. Split sample tests have been undertaken to assess differences in quantile estimates derived using a Generalised Pareto distribution fitted to Peaks-Over-Threshold series. The statistical analyses performed include parametric and non-parametric tests. Mostly, we cannot reject the trend stationarity hypothesis. There is no uniform trend on extreme events in the whole area. However, some trends are evident and significant for specific stations and specific indices. Specifically, it is obvious that extreme rainfall events have risen in the last 20 years only for short durations.

Description: A novel quantitative risk assessment for residential properties at risk of pluvial flooding in Eindhoven, The Netherlands, is presented. A hydraulic model belonging to Eindhoven was forced with low return period rainfall events (2, 5 and 10-year design rainfalls). Three scenarios were analysed for each event: a baseline and two risk-reduction scenarios. GIS analysis identified areas where risk-reduction measures had the greatest impact. Financial loss calculations were carried out using fixed-threshold and probabilistic approaches. Under fixed-threshold assessment, per-event Expected Annual Damage (EAD) reached €38.2 m, with reductions of up to €454,000 resulting from risk-reduction measures. Present costs of flooding reach €1.43bn when calculated over a 50-year period. All net-present value figures for the risk-reduction measures are negative. Probabilistic assessment yielded EAD values up to more than double those of the fixed-threshold analysis which suggested positive net-present value. To the best of our knowledge, the probabilistic method based on the distribution of doorstep heights has never before been introduced for pluvial flood risk assessment. Although this work suggests poor net-present value of risk-reduction measures, indirect impacts of flooding, damage to infrastructure and the potential impacts of climate change were omitted. This work represents a useful first step in helping Eindhoven prepare for future pluvial flooding. The analysis is based on software and tools already available at the municipality, eliminating the need for software upgrading or training. The approach is generally applicable to similar cities.

Description: The use of inverse modeling techniques has greatly increased during the past several years because the advances in numerical modeling and increased computing power. Most of these methods require an a priori definition of the stochastic structure of conductivity ( K ) fields that is inferred only from K measurements. Therefore, the additional conditioning data, that implicitly integrate information not captured by K data, might lead to changes in the a priori model. Different inverse methods allow different degrees of structure adaptation to the whole set of data during the conditioning procedure. This paper illustrates the application of a powerful stochastic inverse method, the Gradual Conditioning (GC) method, to two different sets of data, both non-multiGaussian. One is based on a 2D synthetic aquifer and another on a real-complex case study, the Macrodispersion Experiment (MADE-2), site on Columbus Air Force Base in Mississippi (USA). We have analyzed how additional data change the a priori model on account of the perturbations performed when constraining stochastic simulations to data. Results show how the GC method tends to honour the a priori model in the synthetic case, showing fluctuations around it for the different simulated fields. However, in the 3D real case study, it is shown how the a priori structure is slightly modified not obeying just to fluctuations but possibly to the effect of the additional information on K, implicit in piezometric and concentration data. We conclude that implementing inversion methods able to yield a posteriori structure that incorporate more data might be of great importance in real cases in order to reduce uncertainty and to deal with risk assessment projects.

Description: The fluctuation of the water level in a reservoir may induce various types of slope movements. Some of these movements are new, whereas others are old but reactivated. Many ancient landslide accumulations are distributed in the deep valleys of the eastern Qinghai–Tibet Plateau margin in China and will likely be reactivated after the completion of reservoirs and pose a risk to reservoirs, dams, facilities, and towns near mountainous areas. The Shuangjiaping ancient landslide, located in the Dadu River, Sichuan Province, China, is an example of this case. Since August 2010, the western part of the accumulation body has seen the gradual appearance of deformations. The Pubugou reservoir water level rises and inundates the front edge of the accumulation body, thus threatening the safety of the national highway G108 and 37 houses on it. This study is based on field work investigation, drilling work, aerial photography, and profile survey. The site-scale investigation shows that the deformation area is only a part of an ancient landslide accumulation, with an area of approximately 50.4 × 10 4  m 2 and a volume of ca. 956 × 10 4  m 3 . Boundary and deposit characteristics of landslide accumulation are specified, which could be divided into four zones, namely, zones A and C, which are an avalanche accumulation area mainly composed of large blocks with diameter ranging from 1 to 3 m (some blocks have a diameter ranging from 5 to 10 m), zone B, a residual integrated rock mass accumulation area with “fake bedrock,” and zone D, a fine material accumulation area. A conceptual model is proposed to explain the mechanism and sliding process of this ancient landslide. The model includes translational sliding, stopping and hanging in air, avalanche accumulating, and transforming. The saltation of topography, material structure, and kinematic characteristics is the evidence used to identify the ancient landslide in deeply incised mountain areas. The current activity is found to be a surficial deposit displacement, and the whole landslide accumulation is stable or quasi-stable.

Description: The initiation of debris flows is commonly attributed either to fluidization as a result of rainfall-induced landslides or to gully erosion induced by concentrated runoffs. A series of flume tests have been performed to show how the initial soil moisture influences the initiation of debris flows. At the start of each experiment, surface runoff was generated over loose granular deposits, triggering debris flows. These experimental debris flows enacted different scenarios according to the small variations among the initial soil moistures. In the loose granular deposits with initial soil moistures ranging from 1 to 5 %, most runoff water could infiltrate and trigger a landslide, which accelerated within 1 s to speed over 1 ms −1 and then transformed into a debris flow. In the same soil deposits with initial moistures 〉5 or 〈1 %, the debris flow was initiated by slow gully erosion with episodic events of damming and breaching due to small-scale landslides occurring on the side-slopes of the erosion valley. The slope failures were not triggered by positive pore pressure but by a decrease in suction due to the wetting of the soil. This suction decrease in initially unsaturated slopes explains why the transformation of these slope failures into debris flows are due not only to an increase of pore pressure leading to soil liquefaction, which is one of the expected triggering mechanisms, but also to a loss of the cohesive strength of the soil.

Description: This paper presents a methodology for constructing fragility functions to characterise slope stability under a range of catastrophic earthquakes and rainfalls. The procedures for creating fragility functions, including the first-order reliability method (FORM) and the copula-based sampling method (CBSM), are demonstrated using a selection of typical slopes. The most common failure modes are included, such as the shallow sliding of an infinite slope, circular slip surface of a homogeneous slope, and tetrahedral wedge failure in a rock slope. Owing to the proposed approach, the fragility function can be applied to quantify the failure probabilities over a range of loading conditions with ease, as these are attributed to a function, rather than a design point. The advantage of these definitions is that the uncertainties of correlated soil shear strengths can be incorporated into the reliability models. The established procedure can provide a basis for describing vulnerable behaviour of a slope under various loading conditions and geometries.

Description: Early warning systems (EWSs) rely on the capacity to forecast a dangerous event with a certain amount of advance by defining warning criteria on which the safety of the population will depend. Monitoring of landslides is facilitated by new technologies, decreasing prices and easier data processing. At the same time, predicting the onset of a rapid failure or the sudden transition from slow to rapid failure and subsequent collapse, and its consequences is challenging for scientists that must deal with uncertainties and have limited tools to do so. Furthermore, EWS and warning criteria are becoming more and more a subject of concern between technical experts, researchers, stakeholders and decision makers responsible for the activation, enforcement and approval of civil protection actions. EWSs imply also a sharing of responsibilities which is often averted by technical staff, managers of technical offices and governing institutions. We organized the First International Workshop on Warning Criteria for Active Slides (IWWCAS) to promote sharing and networking among members from specialized institutions and relevant experts of EWS. In this paper, we summarize the event to stimulate discussion and collaboration between organizations dealing with the complex task of managing hazard and risk related to active slides.

Description: Desalination has proven to be a reliable and efficient water supply option in many countries, especially in times of water scarcity. However, high desalination costs and high prices for desalinated water (twice or three times higher than those from traditional water sources) have been hindering an uptake and the development of desalination in many countries. Applied desalination technology, capital and operational costs, production capacity, water salinity are just a few factors determining the final cost of desalinated water that varies considerably between $1.7–9.5/kgal ($0.45–2.51/m 3 ). The final prices for desalinated water and the related costs for local municipalities are among the most crucial determinants of the overall short- and long-term effectiveness of desalination processes. This paper provides an in-depth analysis on economics of desalination with country specific examples. It depicts a comprehensive picture of cost variability of desalinated water and points out challenges for cost-effective desalination in the future.

Description: Drought situations can have significant impacts, affecting large areas and imposing relevant restrictions on multiple economic activities. The severity of those impacts is, normally, assessed through meteorological, agricultural and/or hydrological indices or even through estimation of water deficits or reduction of production yields (for agriculture). However, those assessments usually do not represent the socioeconomic importance of the impacts and the results are not comparable for different types of impacts or distinct regions. In this context, the present work enunciates the main principles to be considered and a methodological approach for socioeconomic evaluation of drought effects, regarding the main supply and demand characteristics of a region (water sources and associated uses), and the hydrological interlinked effects of drought situations. Moreover it describes the methodology process application to Portuguese reality and existing data as the basis of drought’s severity assessment, focusing on two drought prone areas in Portugal: the Guadiana and the Ribeiras do Algarve river basin case studies. Regarding the main specificities of the referred case studies, the economic activities (and water dependent sectors) considered for this methodology were the agricultural and the urban water supply sectors. For each of those sectors, specific assessment procedures where developed in order to estimate the respective economic impacts caused by the drought situation in the area of analysis. A global assessment of the socioeconomic relevance of drought impacts in a region is ensured through comparison of the estimated total economic impacts to the region’s annual average of the Gross Domestic Product (GDP), that enabling the comparison of results for different regions of analysis. The methodology may be applicable to any region with common hydrological and water use data and was developed to be of support for drought management and application on a drought early warning system.

Description:    White-rot fungi are a group of microorganisms capable of degrading xenobiotic compounds, such as polycyclic aromatic hydrocarbons or synthetic dyes, by means of the action of extracellular oxidative enzymes secreted during secondary metabolism. In this study, the transformation of three anti-inflammatory drugs: diclofenac, ibuprofen and naproxen were carried out by pellets of Phanerochaete chrysosporium in fed-batch bioreactors operating under continuous air supply or periodic pulsation of oxygen. The performance of the fungal reactors was steady over a 30-day treatment and the effect of oxygen pulses on the pellet morphology was evidenced. Complete elimination of diclofenac was achieved in the aerated and the oxygenated reactors, even with a fast oxidation rate in the presence of oxygen (77% after 2 h), reaching a total removal after 23 h. In the case of ibuprofen, this compound was completely oxidized under air and oxygen supply. Finally, naproxen was oxidized in the range of 77 up to 99% under both aeration conditions. These findings demonstrate that the oxidative capability of this microorganism for the anti-inflammatory drugs is not restricted to an oxygen environment, as generally accepted, since the fungal reactor was able to remove these compounds under aerated and oxygenated conditions. This result is very interesting in terms of developing viable reactors for the oxidation of target compounds as the cost of aeration can be significantly reduced. Content Type Journal Article Pages 1-12 DOI 10.1007/s10532-011-9494-9 Authors A. I. Rodarte-Morales, Department of Chemical Engineering, School of Engineering, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain G. Feijoo, Department of Chemical Engineering, School of Engineering, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain M. T. Moreira, Department of Chemical Engineering, School of Engineering, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain J. M. Lema, Department of Chemical Engineering, School of Engineering, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    In this work, two novel iron oxidizing bacteria (IOB), namely Gordonia sp. MZ-89 and Enterobacter sp . M01101, were isolated from sewage treatment plants and identified by biochemical and molecular methods. Then, microbially influenced corrosion (MIC) of carbon steel in the presence of these bacteria was investigated. The electrochemical techniques such as potentiodynamic polarization measurements and electrochemical impedance spectroscopy (EIS) were used to measure the corrosion rate and observe the corrosion mechanism. The results showed that the existence of these microorganisms decreased the corrosion potential and enhanced the corrosion rate. Scanning electron microscopy (SEM) images revealed the ground boundary attacks and pitting on carbon steel samples in the presence of these bacteria after polarization. Corrosion scales were identified with X-ray diffraction (XRD). It was demonstrated that these bacteria can greatly affect the crystalline phase of corrosion products that also confirmed by SEM results. It was inferred that these bacteria were responsible for the corrosion of carbon steel, especially in the form of localized corrosion. Content Type Journal Article Pages 1-11 DOI 10.1007/s10532-011-9487-8 Authors H. Ashassi-Sorkhabi, Electrochemistry Research Laboratory, Physical Chemistry Department, Faculty of Chemistry, University of Tabriz, Tabriz, Iran M. Moradi-Haghighi, Electrochemistry Research Laboratory, Physical Chemistry Department, Faculty of Chemistry, University of Tabriz, Tabriz, Iran G. Zarrini, Microbiology Laboratory, Biology Department, Science Faculty, University of Tabriz, Tabriz, Iran R. Javaherdashti, Department of Civil Engineering, Curtin University of Technology, Perth, WA, Australia Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    The common grass Calamagrostis epigeions produces a large amount of dead biomass, which remain above the soil surface for many months. In this study, we determined how exposure of dead biomass above the soil affects its subsequent decomposition in soil. Collected dead standing biomass was divided in two parts, the first one (initial litter) was stored in a dark, dry place. The other part was placed in litterbags in the field. The litterbags were located in soil, on the soil surface, or hanging in the air without contact with soil but exposed to the sun and rain. After 1 year of field exposure, litter mass loss and C and N content were measured, and changes in litter chemistry were explored using NMR and thermochemolysis-GC–MS. The potential decomposability of the litter was quantified by burying the litter from the litterbags and the initial litter in soil microcosms and measuring soil respiration. Soil respiration was greater with litter that had been hanging in air than with all other kinds of litter. These finding could not be explained by changes in litter mass or C:N ratio. NMR indicated a decrease in polysaccharides relative to lignin in litter that was buried in soil but not in litter that was placed on soil surface or that was hanging in the air. Thermochemolysis indicated that the syringyl units of the litter lignin were decomposed when the litter was exposed to light. We postulate that photochemical decay of lignin increase decomposability of dead standing biomass. Content Type Journal Article Pages 1-8 DOI 10.1007/s10532-011-9479-8 Authors Jan Frouz, Faculty of Science, Institute for Environmental Studies, Charles University, Benátská 2, 12800 Praha, Czech Republic Tomáš Cajthaml, Faculty of Science, Institute for Environmental Studies, Charles University, Benátská 2, 12800 Praha, Czech Republic Ondřej Mudrák, Institute of soil biology, Biology Center, AS CR, Na Sádkách 7, 37005 České Budějovice, Czech Republic Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    Arsenic is a carcinogenic compound widely distributed in the groundwater around the world. The fate of arsenic in groundwater depends on the activity of microorganisms either by oxidizing arsenite (As III ), or by reducing arsenate (As V ). Because of the higher toxicity and mobility of As III compared to As V , microbial-catalyzed oxidation of As III to As V can lower the environmental impact of arsenic. Although aerobic As III -oxidizing bacteria are well known, anoxic oxidation of As III with nitrate as electron acceptor has also been shown to occur. In this study, three As III -oxidizing bacterial strains, Azoarcus sp. strain EC1-pb1, Azoarcus sp. strain EC3-pb1 and Diaphorobacter sp. strain MC-pb1, have been characterized. Each strain was tested for its ability to oxidize As III with four different electron acceptors, nitrate, nitrite, chlorate and oxygen. Complete As III oxidation was achieved with both nitrate and oxygen, demonstrating the novel ability of these bacterial strains to oxidize As III in either anoxic or aerobic conditions. Nitrate was only reduced to nitrite. Different electron donors were used to study their suitability in supporting nitrate reduction. Hydrogen and acetate were readily utilized by all the cultures. The flexibility of these As III -oxidizing bacteria to use oxygen and nitrate to oxidize As III as well as organic and inorganic substrates as alternative electron donors explains their presence in non-arsenic-contaminated environments. The findings suggest that at least some As III -oxidizing bacteria are flexible with respect to electron-acceptors and electron-donors and that they are potentially widespread in low arsenic concentration environments. Content Type Journal Article Pages 1-11 DOI 10.1007/s10532-011-9493-x Authors Lucía Rodríguez-Freire, Department of Chemical and Environmental Engineering, University of Arizona, P.O. Box 210011, Tucson, AZ, USA Wenjie Sun, Department of Chemical and Environmental Engineering, University of Arizona, P.O. Box 210011, Tucson, AZ, USA Reyes Sierra-Alvarez, Department of Chemical and Environmental Engineering, University of Arizona, P.O. Box 210011, Tucson, AZ, USA Jim A. Field, Department of Chemical and Environmental Engineering, University of Arizona, P.O. Box 210011, Tucson, AZ, USA Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    To reduce the volume of seaweed wastes and extract polysaccharides, seaweed-degrading bacteria were isolated from drifting macroalgae harvested along the coast of Toyama Bay, Japan. Sixty-four bacterial isolates were capable of degrading “Wakame” ( Undaria pinnatifida ) thallus fragments into single cell detritus (SCD) particles. Amongst these, strain 6532A was the most active degrader of thallus fragments, and was capable of degrading thallus fragments to SCD particles within a day. Although the sequence similarity of the 16S rRNA gene of strain 6532A was 100% similar to that of Microbulbifer elongatus JAMB-A7, several distinct differences were observed between strains, including motility, morphology, and utilization of d -arabinose and gelatin. Consequently, strain 6532A was classified as a new Microbulbifer strain, and was designated Microbulbifer sp. 6532A. Strain 6532A was capable of degrading both alginate and cellulose in the culture medium, zymogram analysis of which revealed the presence of multiple alginate lyases and cellulases. To the best of our knowledge, this is the first study to directly demonstrate the existence of these enzymes in Microbulbifer species. Shotgun cloning and sequencing of the alginate lyase gene in 6532A revealed a 1,074-bp open reading frame, which was designated algMsp . The reading frame encoded a PL family seven enzyme composed of 358 amino acids (38,181 Da). With a similarity of 74.2%, the deduced amino acid sequence was most similar to a Saccharophagus enzyme ( alg 7C ). These findings suggest that algMsp in strain 6532A is a novel alginate lyase gene. Content Type Journal Article Pages 1-13 DOI 10.1007/s10532-011-9489-6 Authors Masayuki Wakabayashi, Graduate School of Science and Engineering, University of Toyama, Toyama, 930-8555 Japan Akihiro Sakatoku, Graduate School of Science and Engineering, University of Toyama, Toyama, 930-8555 Japan Fumio Noda, Sugiyo Co. Ltd, Nanao, Ishikawa 926-8603, Japan Minoru Noda, Sugiyo Co. Ltd, Nanao, Ishikawa 926-8603, Japan Daisuke Tanaka, Graduate School of Science and Engineering, University of Toyama, Toyama, 930-8555 Japan Shogo Nakamura, Graduate School of Science and Engineering, University of Toyama, Toyama, 930-8555 Japan Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description:    The performance of an Arthrobacter viscosus culture to remove diethylketone from aqueous solutions was evaluated. The effect of initial concentration of diethylketone on the growth of the bacteria was evaluated for the range of concentration between 0 and 4.8 g/l, aiming to evaluate a possible toxicological effect. The maximum specific growth rate achieved is 0.221 h −1 at 1.6 g/l of initial diethylketone concentration, suggesting that for higher concentrations an inhibitory effect on the growth occurs. The removal percentages obtained were approximately 88%, for all the initial concentrations tested. The kinetic parameters were estimated using four growth kinetic models for biodegradation of organic compounds available in the literature. The experimental data found is well fitted by the Haldane model ( R 2  = 1) as compared to Monod model ( R 2  = 0.99), Powell ( R 2  = 0.82) and Loung model ( R 2  = 0.95). The biodegradation of diethylketone using concentrated biomass was studied for an initial diethylketone concentration ranging from 0.8–3.9 g/l in a batch with recirculation mode of operation. The biodegradation rate found followed the pseudo-second order kinetics and the resulting kinetic parameters are reported. The removal percentages obtained were approximately 100%, for all the initial concentrations tested, suggesting that the increment on the biomass concentration allows better results in terms of removal of diethylketone. This study showed that these bacteria are very effective for the removal of diethylketone from aqueous solutions. Content Type Journal Article Pages 1-12 DOI 10.1007/s10532-011-9488-7 Authors Filomena Costa, IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal Cristina Quintelas, IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal Teresa Tavares, IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820

Description: As more and more large reservoirs been built, competitive impoundment problem of cascade reservoirs becomes a serious matter in the flood recession. Combining the impounding principle with K value discriminant method, a novel impounding strategy of cascade reservoirs is proposed for determining the impoundment sequence and opportunity of each reservoir in premise of the flood control safety. At the same time, the impounding water level control lines of different frequency runoff are drawn according to the flood routing simulation, and then the Impounding Operation Chart (IOC) is manufactured. On this basis, a model of impoundment dispatching in advance based on the IOC is developed. Then the proposed method can be obviously accelerated by using Self-adaptive Electromagnetism-like Mechanism algorithm (SEM). Compared with the original design of impounding scheme, the result indicates that the optimal scheme can improve the fill storage ratio of cascade reservoirs and ease the contradiction between supply and demand of water resources as well with guaranteeing the safety of flood control in the watershed.

Description: The ability of water managers to maintain adequate supplies in coming decades depends, in part, on future weather conditions, as climate change has the potential to alter river flows from their current values, possibly rendering them unable to meet demand. Reliable climate projections are therefore critical to predicting the future water supply for the United States, but the resolution of the global climate models (GCMs) often used for climate forecasting is too coarse to resolve the changes that can affect hydrology, and hence water supply, at regional to local scales. We therefore apply a statistical downscaling technique that involves a correction of the cumulative distribution functions of the GCM-derived temperature and precipitation for the 20th century, and the application of the same correction to 21st century GCM projections. This is done for three meteorological stations located within the Coosa River basin in northern Georgia, and is used with a surface hydrology model to calculate future river flow statistics for the upper Coosa River. Results are compared to historical Coosa River flow and to flows calculated with the original, unscaled GCM results to determine the impact of potential changes in meteorology on future flows.

Description: Applications of the Soil and Water Assessment Tool (SWAT) require a large amount of input data to perform model simulations. Consequently, uncertainty in input data tends to influence the accuracy of SWAT hydrologic and water quality outputs. It has been shown that input uncertainty can be quantified explicitly during model calibration with latent variables. In this study, latent variables were explored to examine their sensitivity to SWAT outputs and further the potential impact of input uncertainty to model predictions. Results show that the increases in the range of latent variables pose a significant influence to streamflow and ammonia predictions while the impact was less significant in sediment responses. The performance of SWAT in predicting streamflow and ammonia declined with wider ranges of latent variables. In addition, the increase in the range of latent variables did not present noticeable effect on the corresponding predictive uncertainty in sediment predictions. In this study, the calibration results did not improve significantly with the applications of wider ranges of latent variables which are different from the findings in previous research work. The use of latent variables to incorporate input uncertainty may not be the proper alternative choice in terms of generating better results and should be carefully evaluated in the implementations of complex watershed simulation models.

Description: In this study, an iterative framework for robust reclaimed wastewater allocation (IFRWA) was developed to consider multiple climate change scenarios using multi-criteria decision making (MCDM) methods. Each iteration begins with the assumption that an additional unit of water quantity is allocated to reclaimed wastewater (RWW) sites. Based on these allocation conditions, hydrologic simulations are performed and evaluated using the incremental alternative evaluation index (IAEI) to rank the best sites for each unit water quantity. The minimax regret strategy is employed to consider the uncertainty inherent in the climate change scenarios. The consequent robust ranking of the IAEIs is applied to determine the final allocation of the unit water quantity in a given iteration. This iteration continues until the total allocated water quantity satisfies the maximum available capacity of RWW for use in the studied watershed. Our results show that this incremental and robust framework can be used to determine the reasonable capacities of RWW at multiple sites within the watershed by considering various aspects of RWW use, including the water quantity and the socio-economic aspects of decision making. A choice and concentration strategy based on IAEIs should be employed to achieve the maximum utility considering the physical constraints (capacity and cost). If economic considerations, such as the cost of construction and management, are included, this framework can be applied to real problems.

Description:    This study examines biophysical and socio-demographic factors potentially affecting water use patterns of households with mandatory rainwater tanks in South East Queensland (SEQ). The Queensland Development Code (QDC) MP 4.2 promotes the use of rainwater tanks at the domestic level to reduce direct reliance on mains water supply. A sample of 1,134 mandated rainwater tank households were surveyed across SEQ. Results indicated that the majority of participants (78%) had tanks of 5 kL in capacity or larger, with 35% of householders having at least half of roof catchment area connected to their tanks. Also, the majority of participants utilised their rainwater for toilet flushing (97%), clothes washing (94%) and garden irrigation (77%). These biophysical findings indicate a high level of compliance with the QDC MP 4.2 code. Social factors affecting potential yields from mandated rainwater tanks were also examined, to complement the biophysical data obtained. It was found that the majority of tank users were happy to use rainwater as an alternative water supply option for non-potable uses. However, most participants reported being unaware of past or present water restrictions to their water supply, highlighting important social implications for total mains water savings. In conclusion, this study presents important biophysical and social descriptions about mandated water users in urban SEQ, as well as providing a foundation for future modelling of actual yields from mandated rainwater tanks to facilitate improved assessment of mains water savings due to the implementation of mandated rainwater tanks. Content Type Journal Article Pages 1-16 DOI 10.1007/s11269-012-0003-7 Authors Aditi Mankad, CSIRO Ecosystem Sciences, GPO Box 2583, Brisbane, QLD 4001, Australia Meng Nan Chong, CSIRO Land and Water, 41 Boggo Road, Dutton Park, Brisbane, QLD 4102, Australia Ted Gardner, CSIRO Land and Water, 41 Boggo Road, Dutton Park, Brisbane, QLD 4102, Australia Ashok Sharma, CSIRO Land and Water, Highett, VIC 3109, Australia Journal Water Resources Management Online ISSN 1573-1650 Print ISSN 0920-4741

Description:    Monitoring the temporal variations of reference evapotranspiration (ET o ) and quantifying any trends offer valuable information for regional hydrology, agricultural water requirements and water resources management. This study aimed to examine the temporal trends in the Penman–Monteith ET o in the west and southwest of Iran by using the Kendall and Spearman tests after eliminating the influence of significant lag-1 serial correlation from the ET o time series. The magnitudes and starting years of significant ET o trends were determined by the Mann-Kendall rank statistic and the Theil–Sen’s estimator, respectively. For the study period of 1966–2005, a significant positive lag-1 serial correlation coefficient was observed at almost all the stations. The existence of the positive serial correlation in the ET o series increased the possibility of the Kendall and Spearman tests to reject the null hypothesis of no trend while it is true. It was found that the Kendall test was more sensitive than the Spearman test to the existence of the positive serial correlation in the ET o series. After removing the serial correlation effect with pre-whitening method, only three significant increasing ET o trends were obtained at Khorram-Abad, Shahrekord and Zanjan stations at the rates of 0.16, 0.06 and 0.06 mm/day per decade, respectively. The significant increasing ET o trends of Khorram-Abad, Zanjan and Shahrekord stations started in 1997, 1994 and 1998, respectively. The stepwise regression method showed that wind speed was the most dominating variable affecting on the significant changes of ET o . Content Type Journal Article Pages 1-14 DOI 10.1007/s11269-012-0011-7 Authors Hossein Tabari, Department of Water Engineering, Ayatollah Amoli Branch, Islamic Azad University, Amol, Iran Jaefar Nikbakht, Department of Water Engineering, Zanjan University, Zanjan, Iran P. Hosseinzadeh Talaee, Young Researchers Club, Hamedan Branch, Islamic Azad University, Hamedan, Iran Journal Water Resources Management Online ISSN 1573-1650 Print ISSN 0920-4741