ALBERT

Description: 〈b〉The Lituya Bay landslide-generated mega-tsunami – numerical simulation and sensitivity analysis〈/b〉〈br〉 José Manuel González-Vida, Jorge Macías, Manuel Jesús Castro, Carlos Sánchez-Linares, Marc de la Asunción, Sergio Ortega-Acosta, and Diego Arcas〈br〉 Nat. Hazards Earth Syst. Sci., 19, 369-388, https://doi.org/10.5194/nhess-19-369-2019, 2019〈br〉 In 1958, at Lituya Bay in Alaska, the largest tsunami wave ever recorded took place. Since then, its numerical simulation has been a challenge and no numerical model has been able to reproduce, in the real geometry of the bay, the more than 200 m wave and the extreme run-up (climbing of the water up on land) of 524 m. The aim of our research, in the framework of a collaboration between the University of Malága (Spain) and NOAA (US), was to fulfil this gap at the same time as verifying our model.

Description: 〈b〉Reanalysis of the 1761 transatlantic tsunami〈/b〉〈br〉 Martin Wronna, Maria Ana Baptista, and Jorge Miguel Miranda〈br〉 Nat. Hazards Earth Syst. Sci., 19, 337-352, https://doi.org/10.5194/nhess-19-337-2019, 2019〈br〉 We investigate the source of the 1761 earthquake and tsunami. The reanalysis of the tsunami travel times agrees with an earlier suggested source area. We check the geodynamic setting of the area and place a fault as an extension to an identified fault and use numerical modelling to distinguish between two candidate sources. One of our theories is compatible with the geodynamic setting and reproduces well the observed tsunami parameters.

Description: 〈b〉Landslides Data Assimilation Using TRIGRS Based on Particle Filtering〈/b〉〈br〉 Changhu Xue, Guigen Nie, Jie Dong, Shuguang Wu, Jing Wang, Xiuzhen Li, and Xiaogang Zhang〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2019-16,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 This paper provides an approach to apply data assimilation method to stability analysis and parameter update and feedback in a landslide. The experiment is implemented by particle filter algorithm. The result FS sequence of TRIGRS output decreases continuously with time and the assimilation can effectively correct the FS of the model output. The RMSD of FS indicates the assimilation results can correct the estimation of TRIGRS output close to actual observations.

Description: 〈b〉The impact of topography on seismic amplification during the 2005 Kashmir Earthquake〈/b〉〈br〉 Saad Khan, Mark van der Meijde, Harald van der Werff, and Muhammad Shafique〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2019-13,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 In 2005, northern Pakistan was hit by a 7.6 magnitude earthquake. The epicenter was located near capital of the Pakistani territory of Azad Kashmir and also affected Pakistan's Khyber Pakhtunkhwa province and Indian-administered Jammu and Kashmir region. It was believed that the local topography might have significant role in direct and indirect damage in the region. This study shows that the local topography played significant role in the earthquake induced damage in the region.

Description: 〈b〉Brief communication: Remotely piloted aircraft systems for rapid emergency response: road exposure to rockfall in Villanova di Accumoli (central Italy)〈/b〉〈br〉 Michele Santangelo, Massimiliano Alvioli, Marco Baldo, Mauro Cardinali, Daniele Giordan, Fausto Guzzetti, Ivan Marchesini, and Paola Reichenbach〈br〉 Nat. Hazards Earth Syst. Sci., 19, 325-335, https://doi.org/10.5194/nhess-19-325-2019, 2019〈br〉 The paper discusses the use of rockfall modelling software and photogrammetry applied to images acquired by RPAS to provide support to civil protection agencies during emergency response. The paper focuses on a procedure that was applied to define the residual rockfall risk for a road that was hit by an earthquake-triggered rockfall that occurred during the seismic sequence that hit central Italy on 24 August 2016. Road reopening conditions were decided based on the results of this study.

Description: 〈b〉Study on Site Amplification Factor Correction for Earthquake Early Warning System〈/b〉〈br〉 Quancai Xie, Qiang Ma, Jingfa Zhang, and Haiying Yu〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-400,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 This paper make deep evluation of a new mthod for modelling site amplification factor. Though implement this method and make simulation for different cases, we can find that this method show better performance than the previous method and JMA Report. We will better understanding the advantage and disadvantage of this method, although there are some problems needed to consider carefully and to be solved, it shows good potential to be used in the future earthquake early waring system in the world.

Description: 〈b〉Communicating disaster risk? An evaluation of the availability and quality of flood maps〈/b〉〈br〉 Daniel Henstra, Andrea Minano, and Jason Thistlethwaite〈br〉 Nat. Hazards Earth Syst. Sci., 19, 313-323, https://doi.org/10.5194/nhess-19-313-2019, 2019〈br〉 Flood maps can help stakeholders and the public understand their flood risk. We evaluated the quality of publicly accessible flood maps in Canadian communities designated as flood risk areas. We found that most maps (62 %) are low quality (meeting less than half of the criteria) and the highest score was 78 % (seven of nine criteria met). Canada must make a more concerted effort to produce high-quality flood maps to support its international commitment to disaster risk reduction.

Description: 〈b〉Coastal vulnerability assessment: through regional to local downscaling of wave characteristics along the Bay of Lalzit (Albania)〈/b〉〈br〉 Francesco De Leo, Giovanni Besio, Guido Zolezzi, and Marco Bezzi〈br〉 Nat. Hazards Earth Syst. Sci., 19, 287-298, https://doi.org/10.5194/nhess-19-287-2019, 2019〈br〉 This paper reviews the computation of vulnerability levels (VLs) of a coast to inundation with a known model. We refer to the original proposal, detailing the VL computation through an accurate investigation of the local wave climate. We prove that the resulting vulnerability is very sensitive due to the wave features taken into account, which have to be properly assessed. The research is the follow-up of a wider project set along the Bay of Lalzit (Albania).

Description: 〈b〉From examination of natural events a proposal for risk mitigation of lahars by a cellular automata methodology: a case study for Vascún valley, Ecuador〈/b〉〈br〉 Valeria Lupiano, Francesco Chidichimo, Guillermo Machado, Paolo Catelan, Lorena Molina, Salvatore Straface, Gino M. Crisci, and Salvatore Di Gregorio〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-406,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 A method for risk mitigation of secondary lahars, triggered by violent rainfalls, is proposed as alternative to works for their containment or deviation, that could cause future disasters. It is based on the controlled generation of small lahars as a result of collapse of frail dams by backfill, forming momentary ponds as in natural cases. LLUNPIY verifies by simulation path, velocity, thickness, erosion of lahars, that could be produced; a complex case study for Vascún Valley, Ecuador is shown.

Description: 〈b〉A method of deriving operation-specific ski run classes for avalanche risk management decisions in mechanized skiing〈/b〉〈br〉 Reto Sterchi and Pascal Haegeli〈br〉 Nat. Hazards Earth Syst. Sci., 19, 269-285, https://doi.org/10.5194/nhess-19-269-2019, 2019〈br〉 We used a revealed preference approach and identified patterns in risk management decisions of mechanized skiing operations. Our results show that terrain choices of experienced guides depend on a much broader set of factors beyond just the avalanche hazard, including skiing experience or accessibility due to weather. The identified high-resolution ski run hierarchies provide new opportunities for examining professional avalanche risk management practices and developing meaningful decision aids.

Description: 〈b〉Response time to flood events using a social vulnerability index (ReTSVI)〈/b〉〈br〉 Alvaro Hofflinger, Marcelo A. Somos-Valenzuela, and Arturo Vallejos-Romero〈br〉 Nat. Hazards Earth Syst. Sci., 19, 251-267, https://doi.org/10.5194/nhess-19-251-2019, 2019〈br〉 In this work, we propose a novel methodology (ReTSVI) to integrate a social vulnerability index into flood hazard methodologies. ReTSVI combines a series of modules that are pieces of information that interact during an evacuation, such as evacuation rate curves, mobilization, inundation models, and social vulnerability indexes, to create an integrated map of the evacuation rate in a given location.

Description: 〈b〉Comparing the efficiency of hypoxia mitigation strategies in an urban, turbid tidal river, using a coupled hydro sedimentary–biogeochemical model〈/b〉〈br〉 Katixa Lajaunie-Salla, Aldo Sottolichio, Sabine Schmidt, Xavier Litrico, Guillaume Binet, and Gwenaël Abril〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-381,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 〈p〉In view of future coastal hypoxia widespreading, it is essential to define management solutions to preserve a good quality of coastal ecosystems. The lower Tidal Garonne River (TGR, SW France), characterized by the seasonal presence of a turbidity maximum zone and urban water discharges, is subject to episodic hypoxia events during summer low river flow periods. The future climatic conditions (higher temperature; summer droughts) but also an increasing urbanization could enhance hypoxia risks near the city of Bordeaux in the next decades. A 3D model of dissolved oxygen (DO), which couples hydrodynamics, sediment transport and biogeochemical processes, is used to assess the efficiency of different management solutions on TGR oxygenation during summer low-discharge periods. We have runned different scenarios of reduction of urban sewage overflows, displacement of urban discharges downstream from Bordeaux, and/or temporary river flow support during summer period. The model shows that each option limits hypoxia, but with variable efficiency over time and space. Sewage overflow reduction improves DO levels only locally near the city of Bordeaux. Downstream relocation of wastewater discharges allows to reach better oxygenation level in the lower TGR. The support of low river flow limits the upstream TMZ propagation and dilutes TGR waters with well-oxygenated river waters. Scenarios combining wastewater network management and low water replenishment indicate an improvement in water quality over the entire TGR. These modelling outcomes constitute important tools for local water authorities to develop the most appropriate strategies to limit hypoxia in TGR.〈/p〉

Description: 〈b〉The effect of cyclones crossing the Mediterranean region on sea level anomalies at the Mediterranean Sea coast〈/b〉〈br〉 Piero Lionello, Dario Conte, and Marco Reale〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2019-6,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 Large positive and negative sea level anomalies at the coast of the Mediterranean Sea are produced by cyclones moving along the Mediterranean storm track, which are mostly generated in the western Mediterranean. The wind around the cyclone center is the main cause of sea level anomalies when a shallow water fetch is present. The inverse barometer effect produces a positive anomaly near the cyclone pressure minimum and a negative anomaly at the opposite side of the Mediterranean Sea.

Description: 〈b〉The selection of directional sectors for the analysis of extreme wind speed〈/b〉〈br〉 Pedro Folgueras, Sebastián Solari, and Miguel Ángel Losada〈br〉 Nat. Hazards Earth Syst. Sci., 19, 221-236, https://doi.org/10.5194/nhess-19-221-2019, 2019〈br〉 Directional effects are often relevant when studying the extreme values of natural agents, such as wind, waves, or currents. The use of a priori defined divisions is a common but subjective way to address the problem and may not fit data well in certain cases. In this work, a rational method is presented for the selection of directional sectors that, taking into account statistical indicators of the data, leads to the definition of independent and statistically homogeneous sectors.

Description: 〈b〉Delimitation of flood areas based on a calibrated a DEM and geoprocessing: case study on the Uruguay River, Itaqui, southern Brazil〈/b〉〈br〉 Paulo Victor N. Araújo, Venerando E. Amaro, Robert M. Silva, and Alexandre B. Lopes〈br〉 Nat. Hazards Earth Syst. Sci., 19, 237-250, https://doi.org/10.5194/nhess-19-237-2019, 2019〈br〉 This paper aims to map flood hazard areas under the influence of the Uruguay River, Itaqui (southern Brazil), using a calibrated digital elevation model (DEM), historic river level data and geoprocessing techniques. Assessment of the areas that can potentially be flooded can help to reduce the negative impact of flood events by supporting the process of land-use planning in areas exposed to flood hazards.

Description: 〈b〉On the nexus between landslide susceptibility and transport infrastructure – an agent-based approach〈/b〉〈br〉 Matthias Schlögl, Gerald Richter, Michael Avian, Thomas Thaler, Gerhard Heiss, Gernot Lenz, and Sven Fuchs〈br〉 Nat. Hazards Earth Syst. Sci., 19, 201-219, https://doi.org/10.5194/nhess-19-201-2019, 2019〈br〉 Landslides are destructive events, threatening the integrity of land transport systems. This paper presents how road networks are vulnerable to landslides, with emphasis on the consequences for affected road users. Results show the merits of using agent-based traffic modelling to assess the impacts of road network interruptions on rural communities by providing insights into the characteristics of the population affected and the effects on its daily routine in terms of detour costs.

Description: 〈b〉Global detection of rainfall triggered landslide clusters〈/b〉〈br〉 Susanne A. Benz and Philipp Blum〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-391,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 This study aims to identify clusters of landslide events within a global database that are triggered by the same rainfall event. Results show that 14 % of all studied landslide events are actually part of a landslide cluster consisting of at least 10 events. However, in a more regional analysis this number ranges from 30 % for the West Coast of North America to 3 % in the Himalaya Region. These findings provide an improved understanding for managing landslide mitigations on a larger scale.

Description: 〈b〉Flood risk assessment due to cyclone-induced dike breaching in coastal areas of Bangladesh〈/b〉〈br〉 Md Feroz Islam, Biswa Bhattacharya, and Ioana Popescu〈br〉 Nat. Hazards Earth Syst. Sci., 19, 353-368, https://doi.org/10.5194/nhess-19-353-2019, 2019〈br〉 Bangladesh, one of the most disaster-prone countries in the world, has a dynamic delta with 123 polders. Cyclone-induced storm surges cause severe damage to these polders. This paper presents an investigation of the inundation pattern in a polder due to dike failure caused by storm surges and identifies possible critical locations of dike breaches. Moreover, the risk of flooding was assessed and probabilistic flood maps were generated for the breaching of dikes.

Description: 〈b〉Speeding up and boosting tsunami warning in Chile〈/b〉〈br〉 Mauricio Fuentes, Sebastian Arriola, Sebastian Riquelme, and Bertrand Delouis〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2019-9,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 This works provides a simple and fast approach to improve tsunami warning systems in the near field. A color-coded warning map is produced almost instantaneously after the seismic information is received. Time is crucial in the near field case, for instance, the tsunami waves generated in the chilean trench arrives at the coastline around 10–15 minutes. Seismic information takes 3–5 minutes to be ready, we produece a first warning map after 6 minutes of the earthquake origin time.

Description: 〈b〉Annual Characterization of Regional Hydrological Drought using Auxiliary Information under Global Warming Scenario〈/b〉〈br〉 Zulfiqar Ali, Ijaz Hussain, and Muhammad Faisal〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-373,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 Climate change and global warming scenario increase the odds of worsening drought. Therefore, precise characterization and regional monitoring of drought are the major challenge. In this paper, we provide a new way to formulate and improve temporal data of precipitation for the Standardized Drought Index (SDI) type tools. Results show that improved estimates are good candidates for modelling and monitoring hydrological drought with more precision.

Description: 〈b〉California earthquake insurance unpopularity: the issue is the price, not the risk perception〈/b〉〈br〉 Adrien Pothon, Philippe Gueguen, Sylvain Buisine, and Pierre-Yves Bard〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2019-29,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 This paper investigates why earthquake insurance in California is so unpopular despite a significant risk. For that, homeowners’ behavior has been investigated based on the evolution of the earthquake insurance industry in California since its premises. This study shows that most of homeowners disregard earthquake insurance because the premium amount is too high and not because they underestimate the risk. We conclude that new insurance solutions must be designed to fill this protection gap.

Description: 〈b〉Multicriterion assessment framework of flood events simulated with the vertically mixed runoff model in semiarid catchments in the middle Yellow River〈/b〉〈br〉 Dayang Li, Zhongmin Liang, Yan Zhou, Binquan Li, and Yupeng Fu〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-402,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 Flood forecasting and simulation in semiarid regions are always poor, and a single criterion assessment provides limited information for decision making. Here, we propose a multicriterion assessment framework combining the absolute relative error, the flow partitioning and the confidence interval to assess the most striking feature of an event-based flood––the peak flow. Our results show that the accepted rates of flood events improve a lot under the multicriterion assessment framework.

Description: 〈b〉Assessing the tsunami mitigation effectiveness of the planned Banda Aceh Outer Ring Road (BORR), Indonesia〈/b〉〈br〉 Syamsidik, Tursina, Anawat Suppasri, Musa Al'ala, Mumtaz Luthfi, and Louise K. Comfort〈br〉 Nat. Hazards Earth Syst. Sci., 19, 299-312, https://doi.org/10.5194/nhess-19-299-2019, 2019〈br〉 This research aimed to assess the tsunami flow velocity and height reduction produced by a planned elevated road parallel to the coast of Banda Aceh called the Banda Aceh Outer Ring Road (BORR). The Cornell Multi-Grid Coupled Tsunami Model (COMCOT) was used to simulate eight scenarios of the tsunami. One of them was based on the 2004 Indian Ocean tsunami. Two magnitudes of earthquake were used, that is, 8.5 and 9.15 〈i〉M〈/i〉〈sub〉w〈/sub〉. The elevated road can potentially mitigate the impacts of future tsunamis.

Description: 〈b〉Significance of substrate soil moisture content for rockfall hazard assessment〈/b〉〈br〉 Louise M. Vick, Valerie Zimmer, Christopher White, Chris Massey, and Tim Davies〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2019-11,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 Rockfall boulders can travel long distances down slope and it is important to predict how far to prevent fatalities. A comparison of earthquake data from New Zealand during summer and full-scale rockfall experiments in the same soil during winter shows that during dry seasons boulders travel further downslope because the soil is harder. When using predictive tools, engineers and geologists should take soil conditions (and seasonal variations thereof) in to account.

Description: 〈b〉Simultaneous state-parameter estimation of rainfall-induced landslide displacement using data assimilation〈/b〉〈br〉 Jing Wang, Guigen Nie, Shengjun Gao, and Changhu Xue〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2019-24,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 It is necessary to do some prevention study of landslide hazard like the early warning and deformation prediction. This research proposes a new strategy to predict displacement of the landslide. Results confirm the accuracy and effectiveness of this method in displacement prediction, which can provide assistance in early risk assessment and landslide forecasting.

Description: 〈b〉Characteristics of a Hailstorm over the Andean La Paz Valley〈/b〉〈br〉 Marcelo Zamuriano, Andrey Martynov, Luca Panziera, and Stefan Brönnimann〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2019-27,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 This work investigates the formation of a hailstorm over the Tropical Bolivian Andes. Using the WRF atmospheric model, we are able to numerically reconstruct it and we assess the main factors (mountains, lake and surface heating) in the storm formation. We propose physical mechanisms that have the potential to improve the forecasting of similar events; which are known to have a big impact over the Bolivian Altiplano, especially the region near Titicaca lake.

Description: 〈b〉Reducing uncertainty bounds of two-dimensional hydrodynamic model output by constraining model roughness〈/b〉〈br〉 Punit Kumar Bhola, Jorge Leandro, and Markus Disse〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-369,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 The paper study investigates the use of measured water levels to reduce uncertainties bounds of a two-dimensional hydrodynamic model output. Uncertainty assessment generally is not reported in practice due to the lack of best practices and too wide uncertainty bounds. Hence, a novel method to reduce the bounds by constraining the model parameter, mainly roughness, is presented. The operational practitioners as well as researchers benefits from the study in the field of flood risk management.

Description: 〈b〉Culture matters: Factors influencing natural hazard risk preparedness – a survey of Swiss households〈/b〉〈br〉 Elisabeth Maidl, David N. Bresch, and Matthias Buchecker〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-393,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 Natural hazard risk management today aims to involve all actors possibly affected by damage. Citizens are regarded as responsible actors in risk mitigation. Practitioners therefore face the challenge of building social capacity towards such a culture of risk. Research on capacity building in Alpine countries, however, so far lacks empirical evidence on individual preparedness in the common population. This study for the first time provides insights for research and practice.

Description: 〈b〉Impacts of Horizontal Resolution and Air–Sea Flux Parameterization on the Intensity and Structure of simulated Typhoon Haiyan (2013)〈/b〉〈br〉 Mien-Tze Kueh, Wen-Mei Chen, Yang-Fan Sheng, Simon C. Lin, Tso-Ren Wu, Eric Yen, Yu-Lin Tsai, and Chuan-Yao Lin〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-333,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 In this study, we show that both the model horizontal resolution and air-sea flux parameterization can exert large influence on tropical cyclone intensity simulation but with different impacts on wind structures. We highlight the intensification and contraction of TC eyewall in response to the reduction of grid spacing. We also suggest that a well-developed eyewall is more conducive to the positive effect of flux formulas on TC development.

Description: 〈b〉Probabilistic seismic hazard analysis using logic tree approach – Patna District (India)〈/b〉〈br〉 Panjamani Anbazhagan, Ketan Bajaj, Karanpreet Matharu, Sayed S. R. Moustafa, and Nassir S. N. Al-Arifi〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-328,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 〈p〉PGA and SA distribution for Patna district is presented considering both classical and zoneless approach through logic tree frame work to capture the epistemic uncertainty. Seismicity parameters are calculated by considering completed and mixed earthquake data. Maximum magnitude was calculated using three methods namely incremental method, Kijko method and regional rupture characteristics approach. Best suitable GMPE was selected by carrying out 〈q〉efficacy test〈/q〉 using log likelihood. Uniform hazard response spectra have been compared with Indian standard BIS 1893. PGA varies from 0.38 g to 0.30 g from southern to northern periphery considering 2 % probability of exceedence in 50 years.〈/p〉

Description: 〈b〉Efficacy of using Radar Induced Factors in Landslide Susceptibility Analysis: case study of Koslanda, Sri Lanka〈/b〉〈br〉 Ahangama Kankanamge Rasika Nishamanie Ranasinghe, Ranmalee Bandara, Udeni Gnanapriya Anuruddha Puswewala, and Thilantha Lakmal Dammalage〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-335,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 Through the developments of radar and optical remote sensing in temporal, spectral, spatial, and global coverage, availability of images either at low cost or free of charge, large variety of applications are possible. This study assessed efficacy of Radar Induced Factors in identifying landslide susceptibility regions by considering the significance of radar inherent characteristics for disaster studies. With integration of radar factors, high and very low susceptibility regions are increased.

Description: 〈b〉Study on the combined threshold for gully-type debris flow early warning〈/b〉〈br〉 Jian Huang, Theodoor Wouterus Johannes van Asch, Changming Wang, and Qiao Li〈br〉 Nat. Hazards Earth Syst. Sci., 19, 41-51, https://doi.org/10.5194/nhess-19-41-2019, 2019〈br〉 Wenjia gully is a typical gully-type debris flow, which has a large-scale catchment and great hazard risk to the local people. Based on the monitoring data for almost 6 years until now, the characteristics of debris-flow-triggering parameters (pore pressure and rainfall) have been analyzed, especially the relationship with debris flow occurrences. Then, a combined threshold has been presented and tested in order to provide a method for safeguarding the population in the region.

Description: 〈b〉Study of the threshold for the POT method based on hindcasted significant wave heights of tropical cyclone waves in the South China Sea〈/b〉〈br〉 Zhuxiao Shao, Bingchen Liang, Huajun Li, Ping Li, and Dongyoung Lee〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-349,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 〈p〉An assessment of extreme significant wave heights is performed in the South China Sea (SCS), which is crucial for the coastal and offshore engineering in this area. Two significant factors influencing the assessment are the initial database and the assessing method. The initial database is a basic for assessment, and the assessing method is used to extrapolate appropriate return significant wave heights based on this database during a period. In this study, a 40-year (1975–2014) hindcasted significant wave height of tropical cyclone waves is adopted as the initial database. Based on this database, the peak significant wave height of every tropical cyclone wave is directly extracted as the initial sample; the independent and identically distributed assumption is satisfied; and the interference for the selection of the sample is avoided. The peak over threshold (POT) method with the generalized Pareto distribution (GPD) model is employed to extract the sufficiently large and high sample for model estimation. The peak excesses over a sufficiently high value (i.e., threshold) are fitted; thus, the return significant wave heights are highly dependent on the threshold. To determine the unique threshold for the POT method, characteristics of tropical cyclone waves are researched. The research results reveal that the separation value shown in the distribution of the initial sample is suitable for sampling in the SCS. Because the separation value is within the stable threshold range and the asymptotic tail approximation and estimation uncertainty are reasonable, the selected threshold is suitable and the corresponding return significant wave height is reliable.〈/p〉

Description: 〈b〉Ensemble flood simulation for a small dam catchment in Japan using nonhydrostatic model rainfalls. Part 2: Flood forecasting using 1600 member 4D-EnVAR predicted rainfalls〈/b〉〈br〉 Kenichiro Kobayashi, Apip, Le Duc, Tsutao Oizumi, and Kazuo Saito〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-343,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 1 comment)〈br〉 Feasibility of flood forecasting with 1600 rainfall forecasts was investigated. The rainfall forecasts were obtained from an advanced data assimilation system. The high probability of flood occurrence was predicted, which could not be possible by the operational forecast. The necessity of emergency flood operation was shown with a long leading time. This suggests it is worth to invest on increasing numbers of meteorological ensembles to improve flood forecasting.

Description: 〈b〉What's streamflow got to do with it? A probabilistic simulation of the competing oceanographic and fluvial processes driving extreme along-river water levels〈/b〉〈br〉 Katherine A. Serafin, Peter Ruggiero, Kai A. Parker, and David F. Hill〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-347,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 In coastal environments, extreme water levels driving flooding are often generated by many individual processes like storm surge, streamflow, and tides. To estimate flood drivers along a coastal river, we merge statistical simulations of ocean and river forcing with a hydraulic model to produce water levels. We find both ocean and river forcing are necessary for producing extreme flood levels like the 100-yr event, highlighting the need for considering compound events in flood risk assessments.

Description: 〈b〉The impact of drought on the productivity of two rainfed crops in Spain〈/b〉〈br〉 Marina Peña-Gallardo, Sergio Martín Vicente-Serrano, Fernando Domínguez-Castro, and Santiago Beguería〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2019-1,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 Drought events are of great importance in most Mediterranean climate regions and the impacts caused on rainfed crops are particularly evident. In this study the impacts of drought on two representative rainfed crops in Spain (wheat and barley) are assessed by testing various worldwide drought indices and two datasets at different spatial resolution.

Description: 〈b〉Ensemble flood forecasting considering dominant runoff processes – Part 1: Set-up and application to nested basins (Emme, Switzerland)〈/b〉〈br〉 Manuel Antonetti, Christoph Horat, Ioannis V. Sideris, and Massimiliano Zappa〈br〉 Nat. Hazards Earth Syst. Sci., 19, 19-40, https://doi.org/10.5194/nhess-19-19-2019, 2019〈br〉 To predict timing and magnitude peak run-off, meteorological and calibrated hydrological models are commonly coupled. A flash-flood forecasting chain is presented based on a process-based run-off generation module with no need for calibration. This chain has been evaluated using data for the Emme catchment (Switzerland). The outcomes of this study show that operational flash predictions in ungauged basins can benefit from the use of information on run-off processes.

Description: 〈b〉The Effects of Changing Climate on Estuarine Water Levels: A United States Pacific Northwest Case Study〈/b〉〈br〉 Kai Parker, David Hill, Gabriel García-Medina, and Jordan Beamer〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-383,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 Our ability to manage estuaries is currently limited by a poor understanding of how they will evolve into the future. This study explores flooding conditions at two U.S. Pacific estuaries as controlled by changing climate. The hazard is characterized using a variety of models that track oceanic, atmospheric, and hydrologic forcing at decadal scales. It is found that flood surface height varies significantly across estuaries and can be expected to change in complex ways moving into the future.

Description: 〈b〉A stochastic event-based approach for flood estimation in catchments with mixed rainfall and snowmelt flood regimes〈/b〉〈br〉 Valeriya Filipova, Deborah Lawrence, and Thomas Skaugen〈br〉 Nat. Hazards Earth Syst. Sci., 19, 1-18, https://doi.org/10.5194/nhess-19-1-2019, 2019〈br〉 This paper presents a stochastic event-based method for analysis of extreme floods, which uses a Monte Carlo procedure to sample initial conditions, snowmelt and rainfall. A study of 20 catchments in Norway shows that this method gives flood estimates that are closer to those obtained using statistical flood frequency analysis than a deterministic event-based model based on a single design storm.

Description: 〈b〉GIS-based earthquake-triggered landslide susceptibility mapping with an integrated weighted index model in Jiuzhaigou region of Sichuan Province, China〈/b〉〈br〉 Yaning Yi, Zhijie Zhang, Wanchang Zhang, Qi Xu, Cai Deng, and Qilun Li〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2019-8,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 1 comment)〈br〉 On 8 August 2017, a Ms 7.0 earthquake struck the Jiuzhaigou region of Sichuan Province which triggered numerous landslides. In this study, a landslide susceptibility map was generated by using an integrated weighted index model. Results indicated that the integrated model has superior fitting performance and predictive capability. We expect that the generated landslide susceptibility map can be served as the scientific basis to mitigate hazards of the earthquake-triggered landslides.

Description: 〈b〉Economic damage and spillovers from a tropical cyclone〈/b〉〈br〉 Manfred Lenzen, Arunima Malik, Steven Kenway, Peter Daniels, Ka Leung Lam, and Arne Geschke〈br〉 Nat. Hazards Earth Syst. Sci., 19, 137-151, https://doi.org/10.5194/nhess-19-137-2019, 2019〈br〉 We use the Industrial Ecology Virtual Laboratory to analyse the impacts of Tropical Cyclone Debbie on the Australian economy. We show that industries and regions that were not directly affected by storm and flood damage suffered significant job and income losses, highlighting that producers in modern economies are strongly interconnected - initially localised production shortfalls can ripple through entire upstream supply-chain networks and severely affect regional and national economies.

Description: 〈b〉SMC-Floods database: A high resolution press database on floods for the Spanish Mediterranean Coast (1960–2015)〈/b〉〈br〉 Salvador Gil-Guirado, Alfredo Pérez-Morales, and Francisco Lopez-Martinez〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2019-10,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 In this study the SMC-Flood Database for the municipalities of the Mediterranean coast of mainland Spain is presented. This database has enabled the reconstruction of 3008 cases of flooding on a municipal scale between 1960 and 2015. The data analysis reveals a growing trend in the frequency and area affected by floods. The main novelty lies in the fact that we have detected a clear latitudinal gradient of growing intensity and severity of floods with a north–south direction.

Description: 〈b〉Chilling accumulation in temperate fruit trees in Spain under climate change〈/b〉〈br〉 Alfredo Rodríguez, David Pérez-López, Enrique Sánchez, Ana Centeno, Iñigo Gómara, Alessandro Dosio, and Margarita Ruiz-Ramos〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-392,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 Temperate fruit trees account for almost half of the global fruit production. Fruit trees stop their growth during the coldest months of the year until meeting a required cold accumulation. Under future global warming scenarios, a reduction in cold accumulation in Spain is projected. This threatens the viability of some actual tree crops and varieties in some areas, but other varieties with less requirements can be used. Our results allow adapting future tree plantations under climate change.

Description: 〈b〉A spatial multicriteria prioritizing approach for geo-hydrological risk mitigation planning in small and densely urbanized Mediterranean basins〈/b〉〈br〉 Guido Paliaga, Francesco Faccini, Fabio Luino, and Laura Turconi〈br〉 Nat. Hazards Earth Syst. Sci., 19, 53-69, https://doi.org/10.5194/nhess-19-53-2019, 2019〈br〉 Planning geo-hydrological risk mitigation strategies is crucial in contexts of strong urbanization, high population density and great morphological heterogeneity. The paper addresses possible support in comparing small catchments on a quantitative basis and realizing a ranking among them: pointing out the more urgent situations and the relative factors may result in optimizing economic investments in prevention works.

Description: 〈b〉Formation of a multi-translational reactivated ancient landslide in the Three Gorges Reservoir, China〈/b〉〈br〉 Shilin Luo, Xiaoguang Jin, Da Huang, and Tantan Zhu〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-399,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 The field survey and laboratory tests were conducted and analyzed in detail. A conceptual model was proposed to elaborate the formation process and mechanism of this instability. The structural characteristic of mobilized material, rupture surface, topography saltation, and seasonal variation of groundwater exposure could be regarded as valid proofs in identifying ancient landslides. Long-term monitoring and emergency civil protection actions are necessary.

Description: 〈b〉Landslides near Enguri dam (Caucasus, Georgia) and possible seismotectonic effects〈/b〉〈br〉 Alessandro Tibaldi, Paolo Oppizzi, John Gierke, Thomas Oommen, Nino Tsereteli, and Zurab Gogoladze〈br〉 Nat. Hazards Earth Syst. Sci., 19, 71-91, https://doi.org/10.5194/nhess-19-71-2019, 2019〈br〉 In the framework of the NATO Science for Peace and Security Program, we have increased the knowledge on the geohazards affecting the Enguri hydroelectrical plant (Caucasus, Georgia). 2 km from the dam, active deformation (2–5 cm yr〈sup〉−1〈/sup〉) affects a slope facing the water reservoir. Our field, seismological and numerical analyses show that the worst scenario is represented by seismic shaking with a local peak ground acceleration capable of generating an unstable rock volume of up to 48 ± 12 × 10〈sup〉6〈/sup〉 m〈sup〉3〈/sup〉.

Description: 〈b〉Simulation of Fragmental Rockfalls Detected Using Terrestrial Laser Scans from Rock Slopes in South-Central British Columbia, Canada〈/b〉〈br〉 Zac Sala, D. Jean Hutchinson, and Rob Harrap〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-321,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 The work carried out for this study is part of a collaborative research program studying the impact of ground hazards on transportation infrastructure in Canada. The focus of the paper is the testing and application of a new simulation technique which can model the movement of falling rock material. These initial tests show that our simulation technique is capable of re-producing material accumulations from rockfall events which occurred above a section of railway in British Columbia, Canada.

Description: 〈b〉Using cellular automata to simulate wildfire propagation and to assist in fire management〈/b〉〈br〉 Joana Gouveia Freire and Carlos Castro DaCamara〈br〉 Nat. Hazards Earth Syst. Sci., 19, 169-179, https://doi.org/10.5194/nhess-19-169-2019, 2019〈br〉 Cellular automata are useful tools to simulate wildfire propagation. We design a cellular automaton to simulate a severe wildfire that took place in Portugal in 2012 and resulted in almost 25 000 ha burned. The explosive stage is adequately modeled when refining the role played by the wind in fire spreading. Results show a probability of ignition out of the limits of the observed scar, information that may help choose where to allocate resources for firefighting.

Description: 〈b〉Laboratory and field tests and distinct element analysis of dry granular flows and segregation processes〈/b〉〈br〉 Yung Ming Cheng, Wing Hong Ivan Fung, Liang Li, and Na Li〈br〉 Nat. Hazards Earth Syst. Sci., 19, 181-199, https://doi.org/10.5194/nhess-19-181-2019, 2019〈br〉 The work in this paper can be useful for government engineers who need to make a decision on which debris flow barrier to use and assess the consequences of debris flow. Although the experiments in this paper are relatively simple, a deeper understanding of the debris flow process can be enhanced with the results in the present study.

Description: 〈b〉Tsunamigenic potential of a Holocene submarine landslide along the North Anatolian Fault (northern Aegean Sea, off Thasos island): insights from numerical modelling 〈/b〉〈br〉 Alexandre Janin, Mathieu Rodriguez, Dimitris Sakellariou, Vasilis Lykousis, and Christian Gorini〈br〉 Nat. Hazards Earth Syst. Sci., 19, 121-136, https://doi.org/10.5194/nhess-19-121-2019, 2019〈br〉 Here we present new numerical simulations showing that Holocene submarine landslides along the North Anatolian Fault in the Aegean Sea may have triggered tsunamis higher than the ones expected for earthquake sources. During the Holocene, the shore facing the city of Alexandroupoli may have been impacted by tsunami up to 1.65 m at the coastline.

Description: 〈b〉Flash floods versus river floods – a comparison of psychological impacts and implications for precautionary behaviour〈/b〉〈br〉 Jonas Laudan, Gert Zöller, and Annegret H. Thieken〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-407,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 The paper focuses on psychological impacts of river floods and flash floods on affected individuals. Since the connection between psychological characteristics and protection motivation is not yet fully understood, potential coherences are investigated with regard to both flood types. As a main result, the frequency of remembering an event seems to be positively connected to a greater willingness to protect oneself, especially if affected by a weaker flood event.

Description: 〈b〉Characteristics and influencing factors of rainfall-induced landslide and debris flow hazards in Shaanxi Province, China〈/b〉〈br〉 Ke Zhang, Sheng Wang, Hongjun Bao, and Xiaomeng Zhao〈br〉 Nat. Hazards Earth Syst. Sci., 19, 93-105, https://doi.org/10.5194/nhess-19-93-2019, 2019〈br〉 We investigated the spatiotemporal characteristics of landslide and debris flow hazards in Shaanxi Province and quantified the relationships between the occurrence rates of the two hazards and their influencing factors, including antecedent rainfall amount, rainfall duration, rainfall intensity, terrain slope, land cover type and soil type. Rainfall amount, duration, and intensity and slope are the dominant factors controlling slope stability across this region.

Description: 〈b〉Atmospheric conditions of extreme precipitation events in western Turkey for the period 2006–2015〈/b〉〈br〉 Bulent Oktay Akkoyunlu, Hakki Baltaci, and Mete Tayanc〈br〉 Nat. Hazards Earth Syst. Sci., 19, 107-119, https://doi.org/10.5194/nhess-19-107-2019, 2019〈br〉 〈p〉This paper investigates the precipitation types and background physical mechanisms of extreme precipitation events (EPEs) over western Turkey during the period 2006–2015. The EPEs are described as the precipitation values above the 90th percentile obtained from the hourly precipitation dataset, which has high spatial resolution. Precipitation types associated with EPEs are identified by using radar outputs and the Lamb weather type (LWT) approach. It is found that EPEs occurred more frequently in the Marmara and Aegean regions during autumn and winter months. In Marmara, mainly 21 %, 17 %, and 15 % of total autumn EPEs show convective, cyclonic, and sea-effect precipitation characteristics, respectively. While convective EPEs are seen more commonly in the southern portions, cyclonic and sea-effect-originated EPEs mainly affect the southwest and northeastern parts of Marmara. Among these three precipitation types, convective mechanisms generally produce more intense daily precipitation (66.1 mm on average) in the Marmara Region under the proper synoptic conditions (high-pressure center over the Balkan Peninsula and low-pressure center over the eastern Mediterranean). Based on the hourly observations, convective types of extreme precipitation (EP) show two peak values during afternoon and evening times of the day and are linked to diurnal heating. In terms of the Aegean Region, cyclone-originated EP, which includes 65 % of the total winter EPEs, is more common in the whole territory and reaches its peak value during the early hours of the day.〈/p〉

Description: 〈b〉〈q〉We can help us〈/q〉: Does Community Resilience Buffer Against the Negative Impact of Flooding on Mental Health?〈/b〉〈br〉 Torsten Masson, Sebastian Bamberg, Michael Stricker, and Anna Heidenreich〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-389,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 In the current study (〈i〉N〈/i〉 = 118), we found evidence for a buffering effect of community resilience (as a form of social support) on post-disaster mental health and life satisfaction. Our work shows that previous work might has underestimated the effect of social support on post-disaster adjustment. Applying (statistical) moderator analysis, the current work contributes to the discussion on the role of social factors for mental health outcomes of flooding.

Description: 〈b〉Real-time monitoring and FEMLIP simulation of a rainfall-induced rockslide〈/b〉〈br〉 Zhaohua Li, Zhigang Tao, Yuanjun Jiang, Qian Lv, Felix Darve, and Manchao He〈br〉 Nat. Hazards Earth Syst. Sci., 19, 153-168, https://doi.org/10.5194/nhess-19-153-2019, 2019〈br〉 〈p〉Rockslides are a common and devastating problem affecting mining and other engineering activities all over the world; consequently, there have been many studies into their prediction and prevention. This study focused on a recent rockslide in an open-pit mine in Liaoning Province, China. The stability of the rock slope under excavation and rainfall conditions was monitored using an efficient real-time monitoring system. A further numerical analysis was performed using the finite element method with Lagrangian integration points (FEMLIP), and two forms of the normalized global second-order work were calculated to analyze the stability of the rock slope. In fact for the future it would be very interesting to compare measurements and simulations in real time, and not only to develop back computations after failure. The numerical results indicate that the rock slope remained stable during excavation, yet lost stability after subsequent rainfall. Water infiltration, along with a major geological discontinuity, degraded the strength of the weak zone and induced the rockslide. The monitoring approach presented its robustness and generality, and was worth being generalized. The numerical approach proposed the evolution of the safety factor, the monitoring data were compared, and the mechanism of the rockslide was determined. It could be used as an assistant tool for disaster prediction.〈/p〉

Description: 〈b〉LES Modeling of Tsunami-like Solitary Wave Processes over Fringing Reefs〈/b〉〈br〉 Yu Yao, Tiancheng He, Zhengzhi Deng, Long Chen, and Huiqun Guo〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-376,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 Tsunami can be destructive when it inundates the coastal areas. In recent years, the positive role of coral reefs in mitigating the tsunami waves has aroused the attentions among the scholars. We therefore investigate the tsunami wave interaction with a reef profile via a sophisticated numerical model. We find that the low-lying coastal areas, fringed by coral reefs with milder back-reef beaches and smaller lagoons, are less susceptible to the coastal inundation during a tsunami event.

Description: 〈b〉From rapid visual survey to multi-hazard risk prioritisation and numerical fragility of school buildings in Banda Aceh, Indonesia〈/b〉〈br〉 Roberto Gentile and Carmine Galasso〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-397,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 1 comment)〈br〉 This paper introduces the INSPIRE index, which quantifies seismic risk of reinforced concrete buildings relatively to a portfolio. A rapid visual survey form is also proposed, which allows to (1) calculate the INSPIRE index, (2) calculate a tsunami risk index, (3) define archetype buildings to be analysed in more detail. The effectiveness of such instruments is demonstrated with an application to 85 school buildings in Indonesia, also comparing the results with more detailed computer simulations.

Description: 〈b〉Analysis of Spatiotemporal variations in mid-upper tropospheric methane during the Wenchuan Ms8.0 earthquake by three indices〈/b〉〈br〉 Jing Cui and Xuhui Shen〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-342,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 〈p〉This research studied the spatiotemporal variation in methane in the mid-upper troposphere during the Wenchuan earthquake (12 May, 2008) using AIRS retrieval data and discussed the methane anomaly mechanism. Three indices were proposed and used for analysis. Our results show that the methane concentration increased significantly in 2008, with an average increase of 5.12 * 10〈sup〉−8〈/sup〉, compared to the average increase of 1.18 * 10〈sup〉−8〈/sup〉 in the previous five years. The Alice and Diff indices can be used to identify methane concentration anomalies. The two indices showed that the methane concentration distribution before and after the earthquake broke the distribution features of the background field. As the earthquake approached, areas of high methane concentration gradually converged towards the west side of the epicenter from both ends of the Longmenshan fault zone. Moreover, a large anomalous area was centered at the epicenter eight days before the earthquake occurred, and a trend of strengthening, weakening and strengthening appeared over time. The Gradient index showed that the vertical direction obviously increased before the main earthquake, and the value was positive. The gradient value is negative during coseismic or postseismic events. The gradient index reflects the gas emission characteristics to some extent. We also determined that the methane release was connected with the deep crust-mantle stress state, as well as microfracture generation and expansion. However, due to the lack of any technical means to accurately identify the source and content of methane in the atmosphere before the earthquake, an in-depth discussion has not been conducted, and further studies on this issue may be needed.〈/p〉

Description: 〈b〉Brief communication: Rethinking the 1998 China flood to prepare for a nonstationary future〈/b〉〈br〉 Shiqiang Du, Xiaotao Cheng, Qingxu Huang, Ruishan Chen, Philip Ward, and Jeroen C. J. H. Aerts〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-394,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 A mega-flood in 1998 caused tremendous losses in China, and triggered large investments in flood risk management. However, flood memory change over time while rapid urbanization and climate change pose new challenges. Novel flood risk management approaches are thus required in addition to reinforcing structural protection, such as levees. These include a risk-based urban planning and a coordinated water governance system with public participation.

Description: 〈b〉Assessing road segment impact on accessibility to critical services in case of a hazard〈/b〉〈br〉 Sophie Mossoux, Matthieu Kervyn, and Frank Canters〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-379,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 〈p〉Development of hazard maps is one of the measures promoted by the international community to reduce risk. Hazard maps provide information about the probability of given areas to be affected by one or several hazards. As such they are useful tools to evaluate risk and support the development of safe policies. So far studies combining hazard mapping with accessibility to services are few. In hazardous environments, accessibility of the population to strategic infrastructure is important because emergency services and goods will principally be offered at or provided from these locations. If a road segment is blocked by a hazard, accessibility to services may be affected, or worse, people may be completely disconnected from specific services. The importance of each road segment in the transport network as a connecting element enabling access to relevant services is therefore critical information for the authorities. In this study, we propose a new application of hazard mapping which aims to define the importance of each road segment in the accessibility to services, taking in account the probability of being affected by a hazard. By iteratively removing one segment after the other from the road network, changes in accessibility to critical infrastructure are evaluated. Two metrics of road segment importance considering the population affected and the hazard probability are calculated for each segment: a road accessibility risk metric and a users' path vulnerability metric. Visualization of these road metrics is a useful way of valuing hazard maps and may help to support discussions about the development of new infrastructure, road capacity increase and maintenance of existing infrastructures, and evacuation procedures.〈/p〉

Description: In this paper, we present a new source assessment of the La Palma collapse scenario previously described and studied in Abadie et al. (2012). Three scenarios (i.e., slide volumes of 20, 40 and 80 km3) are considered, from the initiation of the slide to the water waves generation, using THETIS, a 3D Navier–Stokes model. The slide is considered as a Newtonian fluid whose viscosity is adjusted to approximate a granular behavior. After 5 minutes of propagation with THETIS, the generated water wave is transferred into FUNWAVE-TVD for 15 minutes of Boussinesq model simulation. Then, four different depth-averaged codes are used to propagate the wave to the Guadeloupe area, Europe and French coasts. Finally, the wave impact in terms of run-up is evaluated through direct computations in specific areas or using theoretical formulas. Although the wave source appears reduced due to the rheology used compared to former works, the wave impact is still significant for the maximum slide volume considered on surrounding islands and coasts, as well as on remote most exposed coasts such as Guadeloupe. In Europe and in France, the wave impact is moderate (for specific areas in Spain and Portugal) to weak (Atlantic French coast). The comparison between the different wave models in overlapping computational regions shows an overall agreement in terms of first wave amplitude and time of arrival, but differences appear in the trailing waves.

Description: Residual shear strength of soils is an important soil parameter for assessing the stability of landslides. To investigate the effect of the shear rate on the residual shear strength of loessic soils, a series of ring shear tests were carried out on loess from three landslides at two shear rates (0.1 mm/min and 1 mm/min). Naturally drained ring shear tests results showed that the shear displacement to achieve the residual stage for specimens with higher shear rate was greater than that of the lower rate; both the peak and residual friction coefficient became smaller with increase of shear rate for each sample; at two shear rates, the residual friction coefficients for all specimens under the lower normal stress were greater than that under the higher normal stress. The tests results revealed that the difference in the residual friction angle фr at the two shear rates, фr (1)–фr (0.1), under each normal stress level were either positive or negative values. However, the difference фr(1)–фr (0.1) under all normal stresses was negative, which indicates that the residual shear parameters reduced with the increasing of the shear rate in loess area. Such negative shear rate effect on loess could be attributed to a greater ability of clay particles in specimen to restore broken bonds at low shear rates.

Description: The objective of this paper is the assessment of bioclimatic conditions in Sebia. A special emphasis has been given to the heat budget bioclimatic Universal Thermal Climate Index (UTCI) whose purpose is to evaluate degree of thermal stress that human body is exposed to during the last twenty years. In addition, the thresholds of daily maximum temperatures are analysed in order to identify increase and frequency of heat waves in Serbia. For this research, daily and hourly (07 h and 14 h) meteorological data from 3 weather station (Mt. Zlatibor, Novi Sad, Niš) are collected for the period 1998–2017. The results show that the most frequent UTCI heat stress categories are strong heat stress and very strong heat stress. The most extreme heat waves events are occurred in 2007, 2012, 2015 and 2017. Moreover, there were three Heat wave events (HWE) in Niš occurred in July, 2007 lasting 3, 10 and 4 days in row. Heat wave events (HWE) In July 2007 (10 days) and July 2012 (9 days) in Niš are occurrences with maximum number of days in row recorded.

Description: Post-event damage assessments are essential to document the effects of high-impact weather events such as floods or strong wind events. Moreover, evaluating the damage and characterizing its extension and intensity can be helpful for further analysis such as completing a diagnostic meteorological case study. This paper presents a methodology to perform field surveys of damage caused by strong winds of convective origin, i.e. tornado, downburst and other types of convective winds. It is based on previous studies and also on 136 fieldworks performed by the authors in Spain from 2004 to 2018. The methodology includes the systematic collection of pictures and records of damages on man-made structures and on vegetation, as well as collection of any available Automatic Weather Station data, witness reports and images of the phenomenon and their location and orientation. Three final deliverables are proposed to synthesize the data recorded: (i) A summary of the fieldwork; (ii) A table consisting of detailed geolocated information about each damage, and (iii) A map or a .kml file containing the previous information ready for graphical display and further analysis. This methodology has been applied by the authors in the past, sometimes only a few hours after the event occurrence and, in many occasions, when the type of convective phenomenon (e.g. tornado, downburst) was uncertain. In the latter case the information resulting from this methodology has proofed very useful to discern the phenomenon type, based on the damage patterns particularly if no witness reports were available. The application of systematic methodologies as the one presented here is necessary in order to build homogeneous databases of severe weather cases and high impact weather events.

Description: Since drought is a multifaceted phenomenon, more than one variable should be considered for a proper understanding of such extreme event in order to implement adequate risk mitigation strategies such as weather or agricultural indices insurance programs, or disaster risk financing tools. This paper proposes a new composite drought index that accounts for both meteorological and agricultural drought conditions, by combining in a probabilistic framework two consolidated drought indices: the Standardized Precipitation Index (SPI) and the Vegetation Health Index (VHI). The new index, called Probabilistic Precipitation Vegetation Index (PPVI), is scalable, transferable all over the globe and can be updated in near-real time. Furthermore, it is a remote-sensing product, since precipitation are retrieved from satellite and the VHI is a remote-sensing index. In addition, a set of rules to objectively identify drought events is developed and implemented. Both the index and the set of rules have been applied to Haiti. The performance of PPVI has been evaluated by means of the Receiver Operating Characteristics curve and compared to the ones of SPI and VHI considered separately. The new index outperformed SPI and VHI both in drought identification and characterization, thus revealing potential for an effective implementation within drought early warning systems.

Description: Combined with the spatial data processing capability of geographic information systems (GIS), a three-dimensional (3D) landslide surge height calculation method is proposed based on grid column units. First, the data related to the landslide are rasterized to form grid columns, and a force analysis model of 3D landslides is established. Combining the vertical strip method with Newton's laws of motion, dynamic equilibrium equations are established to solve for the surge height. Moreover, a 3D landslide surge height calculation expansion module is developed in the GIS environment, and the results are compared with those of the two-dimensional Pan Jiazheng method. Comparisons show that the maximum surge height obtained by the proposed method is 24.6 % larger than that based on the Pan Jiazheng method. Compared with the traditional two-dimensional method, the 3D method proposed in this paper better represents the actual spatial state of the landslide and is more suitable for risk assessment.

Description: This study aims to test the capacity of Flow-3D regarding the simulation of a rockslide impacting a water body by evaluating the influence of the extent of the computational domain, the grid resolution, the corresponding computation times and the accuracy of modelling results. A detailed analysis of the Lituya Bay event (1958, Alaska, maximum recorded run-up of 524 m a.s.l.) is presented. A focus on the tsunami formation and run-up in the impact area is accomplished with the numerical model. Several simulations with a simplified bay geometry are accomplished in order to test the concept of a denser fluid for the impacting rockslide material compared to the water in the bay. Further, a real topography and bathymetry of the impact area are set up. The observed maximum run-up in the impact area can be reproduced using a uniform grid resolution of 5 m, where the wave overtops the hill crest on the opposite side of the impact area, then flowing diagonally along the slopes. The model is enlarged along the entire bay to simulate the propagation of the wave. The tsunami trimline is best reproduced when using a mesh size of 15 x 15 x 10 m. The trimline mainly results from the primary wave, but in some locations also from reflected waves. The dense fluid is a suitable, simple concept to recreate a sliding mass impacting a water body, in this case with impact velocities of 94 ms−1. The tsunami event and the related trimline are well reproduced using the 3D-modelling approach with the density evaluation model available in Flow-3D.

Description: For many geotechnical purposes, the proper estimation of shapes and dimensions of landslide rupture zones is of significant importance. Very often this exact delineation is difficult due to the lack of information on rupture zone extents in 3D. Based on a global landslide inventory, this study presents a refined statistical analysis correlating dimension-related and shape-related parameters characterizing a rupture zone in 3D to its volume. Dimension-parameters are approximated by linear regressions increasing with greater volumes, whereas shape-related parameters appear stable throughout the entire range of volumes. Revealing themselves as very stable, these correlations can be used, hence, to extrapolate from a distinct parameter to the volume of a landslide rupture zone. In a second stage, ratios of dimension-related parameters are correlated with rupture zone volumes. Also, this type of correlation delivers very stable results showing that ratios are constant throughout the entire range of volumes. Making use of this ratio consistency, it is possible to deduce one of the two parameters when the other one is given. This latter aspect seems to be promising for remote sensing surveys when initial rupture areas or rupture volumes should be delineated.

Description: A tailings dam accident can cause serious ecological disaster and property loss. Simulation of a tailings dam accident in advance is useful for understanding the tailings flow characteristics and assessing the possible extension of the impact area. In this paper, a three-dimensional (3-D) computational fluid dynamics (CFD) approach was proposed for reasonably and quickly predicting the flow routing and impact area of mud flow from a dam failure across 3-D terrain. The Navier–Stokes equations and the Bingham-Papanastasiou rheology model were employed as the governing equations and the constitutive model, respectively, and solved numerically in the finite volume method (FVM) scheme. The volume of fluid (VOF) method was used to track the interface between the tailings and air. The accuracy of the CFD model and the chosen numerical algorithm were validated using an analytical solution of the channel flow problem and a laboratory experiment on the dam break problem reported in the literature. In each issue, the obtained results were very close to the analytical solutions or experimental values. The proposed approach was then applied to simulate two scenarios of tailings dam failures, one of which was the Feijão tailings dam that failed on 25 January 2019, and the simulated routing coincided well with the in situ investigation. Therefore, the proposed approach does well in simulating the flow phenomenon of tailings after a dam break, and the numerical results can be used for early warning of disasters and emergency response.

Description: Recovering from major earthquakes is a challenge, especially in mountainous environments where post-earthquake mass movements and floods may cause substantial impacts. We monitored the reconstruction of Longchi town in Sichuan, China, over a period of 11 years, following the 2008 Wenchuan earthquake. Seven inventories of buildings, land use, roads and mitigation measures were made by using remote sensing image interpretation and field surveys. Most of the buildings were rebuild by 2010 and reconstruction was completed by 2012. The total economic value of the new buildings in 2010 was much more than the pre-earthquake situation in 2007. Unfortunately, post-seismic hazards were not sufficiently taken into consideration in the recovery planning before the catastrophic debris flow disaster in 2010. As a result, the direct economic loss from post-seismic disasters was more than the loss caused by the earthquake itself. The society showed an impact – adapt pattern, taking losses from disasters and then gaining resistance.

Description: In this study, time-dependent probabilistic tsunami hazard analysis (PTHA) is performed for Tuzla, Istanbul in the Sea of Marmara, Turkey, using various earthquake scenarios of Prince Island Fault within next 50 and 100 years. Monte Carlo (MC) simulation technique is used to generate a synthetic earthquake catalogue which includes earthquakes having magnitudes between Mw 6.5 and 7.1. This interval defines the minimum and maximum magnitudes for the fault in the case of entire fault rupture which depends on the characteristic fault model. Based on this catalogue, probability of occurrence and associated tsunami wave heights are calculated for each event. The study associates the probabilistic approach with tsunami numerical modelling. Tsunami numerical code NAMI DANCE was used for tsunami simulations. According to the results of the analysis, distribution of probability of occurrence corresponding to tsunami hydrodynamic parameters are represented. Maximum positive and negative wave amplitudes show that tsunami wave heights up to 1 m have 65 % probability of exceedance for next 50 years and this value increases by 85 % in Tuzla region for next 100 years. Inundation depth also exceeds 1 m in the region with probabilities of occurrence of 60 % and 80 % for next 50 and 100 years, respectively. Moreover, Probabilistic inundations maps are generated to investigate inundated zones and the amount of water penetrated inland. Probability of exceedance of 0.3 m wave height, ranges between 10 % and 75 % according to these probabilistic inundation maps and the maximum inundation distance calculated among entire earthquake catalogue is 60 m in this test site. Furthermore, at synthetic gauge points which are selected along the western coast of the Istanbul by including Tuzla coasts. Tuzla is one of the area that shows high probability exceedance of 0.3 m wave height, which is around 90 %, for the next 50 years while this probability reaches up to more than 95 % for the next 100 years.

Description: Derechos are high-impact convective wind events that can cause fatalities and widespread losses. In this study, 40 derechos affecting Germany between 1997 and 2014 are analysed to estimate the derecho risk. Similar to the United States, Germany is affected by two derecho types. The first derecho type forms in south-westerly 500-hPa flow downstream of intense west-European troughs and accounts for 22 of the 40 derechos. These derechos are named warm-season type due to their peak occurrence in June and July. Warm-season type derechos frequently start over southwestern Germany in the afternoon and move either eastward along the Alpine forelands or north-eastward across southern central Germany. Only one warm-season derecho moved across the North Sea and one moved across the Baltic Sea in the 18-year period. Proximity soundings of German warm-season type derechos indicate strong deep-layer vertical wind shear with a median of 20 m s−1 0–6-km shear and mixed-layer Convective Available Potential Energy (mixed-layer CAPE) between 20 and 2600 J kg−1 with a median around 500 J kg−1. The second derecho type forms in north-westerly 500-hPa flow and accounts for 18 of the 40 derechos. These derechos form in strong north-westerly flow, frequently in association with mid-tropospheric PV intrusions. They are named cold-season type because they are associated with a secondary peak from December to February. Cold-season type derechos start over or close to the North Sea and primarily affect north and central Germany; their start time is not strongly related to the peak of diurnal heating. Proximity soundings indicate high-shear–low-CAPE environments with a median 0–6-km shear of 35 m s−1 and a median mixed-layer CAPE of 3 J kg−1. Environmental CAPE is zero in almost half of cold-season type proximity soundings. Fifteen warm-season type and nine cold-season type derechos had wind gusts reaching 33 m s−1 in at least at three locations. Although warm-season derechos are more frequent, the path length of cold-season type derechos is on average 1.4 times longer. Thus, these two types of German derechos are likely to have similar impacts.

Description: Urban development models typically provide simulated building areas in an aggregated form. When using such outputs to parametrize pluvial flood risk simulations in an urban setting, we need to identify ways to characterize imperviousness and flood exposure. We develop data-driven approaches for establishing this link, and we focus on the data resolutions and spatial scales that should be considered. We use regression models linking aggregated building areas to total imperviousness, and models that link aggregated building areas and simulated flood areas to flood damages. The data-resolutions used for training regression models are demonstrated to have a strong impact on identifiability, with too fine data resolutions preventing the identification of the link between building areas and hydrology, and too coarse resolutions leading to uncertain parameter estimates. The optimal data resolution for modelling imperviousness was identified to be 400 m in our case study, while an aggregation of the data to at least 1000 m resolution is required when modelling flood damages. In addition, regression models for flood damages are more robust when considering building data with coarser resolutions of 200 m than for finer resolutions. The results suggest that aggregated building data can be used to derive realistic estimations of flood risk in screening simulations. Future work needs to focus on training regression approaches where different degrees of flood-awareness in landuse management can be considered.

Description: The 2004 Indian Ocean Tsunami and the 2011 Great East Japan earthquake and tsunami caused large-scale topographic changes in coastal areas. Whereas much research has focused on coastlines that have or had large human populations, little focus has been paid on coastlines that have little or no infrastructure. The importance of examining erosional and depositional mechanisms of tsunami events lies in the rapid reorganisation that coastlines must undertake immediately after an event. Through understanding the precursor conditions to this reorganisation is paramount to the reconstruction of the coastal environment. This study examines the locations of sediment erosion and deposition during the 2004 Indian Ocean Tsunami event on the relatively pristine Phra Thong Island, Thailand. Coupled with satellite imagery, we use numerical simulations and sediment transportation models to determine the locations of significant erosion and the areas where much of that sediment was redeposited during the tsunami inundation and backwash processes. Our modelling approach confirms that beaches on Phra Thong Island were significantly eroded by the 2004 tsunami, predominantly during the backwash phase of the first and largest wave to strike the island. Although 2004 tsunami sediment deposits are found on the island, we demonstrate that most of the sediment was deposited in the shallow coastal area, facilitating quick recovery of the beach when normal coastal processes resume.

Description: Small communities living in high mountainous terrains, in Hubei Province are often impacted by landslide hazard. Past work by China Geology Survey focused only on hazard assessment at 1 : 100 000 scales. In this study, we conducted a more-detailed semiquantitative landslide and risk assessment at a community level and scale of 1 : 10 000. We applied the probabilistic method to assess the landslide spatial, temporal and size probabilities while the landslide hazard and risk assessment were considered for four return periods (5, 10, 20 and 50 years) and two size scenarios (landslide volume). The spatial probability by susceptibility mapping with an accuracy of 84 % indicates that Quaternary deposits and weathered eluvium from Ordovician limestone are the two major controlling factors. Most building areas in hazard maps are located at the foot of major slopes where hazard probabilities are very high. We computed the loss of lives and properties for each slope. The result shows that 1530 people and 126 million RMB economics were at risk of being affected by landslides with a 50-year return period and a landslide volume of fifty thousand cubic meters. Meanwhile, the longer the return period, the higher the hazard probability is. Compared with the function by ordinary least square method, classic inverse gamma and power law distribution of landslide magnitude and frequency are not suitable for landslide size probability analysis in the study area. The proposed procedure is proved to be more useful to complement risk assessment on the small scale of 100 000 in west Hubei, China.

Description: The evaluation of the seismic fragility of buildings is one key task of earthquake safety and loss assessment. Many research reports and papers have been published over the past four decades that deal with the vulnerability of buildings to ground motion caused by earthquakes in China. We first scrutinized 69 papers and theses studying building damage for earthquakes occurred in densely populated areas. They represent observations where macro-seismic intensities have been determined according to the Chinese Official Seismic Intensity Scale. From these many studies we derived the median fragility functions (dependent on intensity) for four damage limit states of two most widely distributed building types: masonry and reinforced concrete. We also inspected 18 publications that provide analytical fragility functions (dependent on PGA) for the same damage classes and building categories. Thus, a solid fragility database based on both intensity and PGA is established for seismic prone areas in mainland China. A comprehensive view of the problems posed by the evaluation of fragility for different building types is given. Necessary comparison with international projects with similar focus is conducted. Based on the newly collected fragility database, we propose a new approach in deriving intensity-PGA relation by using fragility as the bridge and reasonable intensity-PGA relations are developed. This novel approach may shed light on new thought in decreasing the scatter in traditional intensity-PGA relation development, i.e., by further classifying observed macro-seismic intensities and instrumental ground motions based on difference in building seismic resistance capability.

Description: In the context of sustainable agricultural management, drought monitoring plays a crucial role assessing the vulnerability of agriculture to drought occurrence. Drought events are very frequent in the Iberian Peninsula (and in Portugal in particular) and an increase of frequency of these extreme events are expected in a very near future. Therefore, the quantitative assessment of the natural ecosystems vulnerability to drought is still very challenging, mainly due to the difficulties of having a common definition of vulnerability. Consequently, several methods have been proposed to assess agricultural vulnerability. In this work, a principal component analysis (PCA) was performed based on the components which characterize the Exposure, Sensitivity and Adaptative Capacity of the agricultural system to drought events with the aim of generating maps of vulnerability of agriculture to drought in Portugal. Several datasets were used to describe these components, namely drought indicators, vegetation indexes and soil characterization variables. A comparison between the PCA-based method and a subjective non-automatic categorical method using the same indicators was performed. Results show that both methods identify Minho and Alentejo as regions of low and extreme vulnerability, respectively. The results are very similar between the two methods, with small differences on certain vulnerability class. However, the PCA method has some advantages over the categorical method, namely the ability to identify the sign of the indicators, not having to use the indicator-component subjective relationship, nor calculating weights. Furthermore, the PCA method is fully statistical and presents results according to a prior knowledge of the region and the data used.

Description: The Italian Tsunami Effects Database (ITED), consists of an ensemble of records reporting tsunami effects observed at several Observation Points (OP) along the Italian coasts from historical times. ITED was compiled starting from the Euro Mediterranean Tsunami Catalogue (EMTC) and it focuses on the propagation effects observed along the Italian coasts, providing information on how each locality was interested by tsunami effects over time. The effects reported in ITED are related to tsunamis occurred within the Italian territory and contained in the EMTC; these events were excerpt, analyzed and updated according to recent studies published in literature. The database can be accessed through a web GIS application, that displays the location of the OPs indicating for each of them the description of tsunami effects found in literature and the corresponding bibliographic references as well as the metrics related to the observed event. Based on those descriptions, the estimate value of the tsunami intensity has been assigned to each OP, according to both the Sieberg-Ambraseys and the Papadopoulos-Imamura scales. All the ITED data, including quantitative data such as runup, inundation, withdrawal, can be retrieved by accessing online the database through the WebApp that was expressly designed and built for this purpose. ITED contains 300 observations of tsunami effects at 225 OPs referred to 186 Italian main localities, hereafter called Place Name (PN) related to 72 Italian tsunamis. The database provides also the tsunami-history for each PN, allowing the end user to have a complete picture of how the PN is prone to tsunami effects.The realization of ITED was also the occasion to update Italian tsunamis contained in the EMTC, leading to the release of a new version of the EMTC catalogue, named EMTC2.0. ITED was specifically built to meet the needs of the tsunami hazard community, thus providing useful information that can improve the knowledge on how much the national territory is exposed to tsunami risk.

Description: On 22 December 2018, a tsunami was generated from the Mount Anak Krakatau area that was caused by volcanic flank failures. The tsunami had severe impacts on the western coast of Banten and the southern coasts of Lampung in Indonesia. A series of surveys to measure the impacts of the tsunami was started three days after the tsunami and lasted ten days. Immediate investigations allowed the collection of relatively authentic images of the tsunami impacts before the clearing process started. This article investigates the impacts of the 2018 Sunda Strait tsunami on the affected areas and presents an analysis of the impacts of pure hydrodynamic tsunami forces on buildings. Impacts of the tsunami were expected to exhibit different characteristics than those found following the 2004 Indian Ocean tsunami in Aceh. Data was collected from 117 flow depths along the Banten and Lampung coasts. Furthermore, 98 buildings or houses were assessed for damage. Results of this study revealed that the flow depths were higher in Banten than in Lampung. Directions of the tsunami arrays created by the complex bathymetry around the strait caused these differences. Tsunami-induced damage to buildings was mostly the result of impact forces and drag forces. Damping forces could not be associated with the damages. The tsunami warning system in Indonesia should be extended to anticipate non-seismic tsunamis, such as landslides and volcanic processes driven by tsunamis. Lack of a tsunami warning during the first few minutes after the generation of the first wave led to a significant number of human casualties at both of the affected areas.

Description: In some seaside communities in northern Norway the vulnerability to weather induced access disruptions is high, due to frequent high impact weather in the region and the dependency on one or few roads particularly exposed to avalanches, wind and rockfall. In this paper we study changes in typical winter weather indices known to potentially cause such access disruptions in the region. A gridded observation-based dataset is used to analyse changes in present climate (1958–2017), while an ensemble of 10 EURO-CORDEX climate model simulations are used to assess expected future changes in the same indices, towards the end of this century. We focus on weather indices associated with snow avalanches, such as maximum snow amount and snowfall intensity and frequency, but also freeze-thaw cycles in terms of temperatures crossing zero degrees Celsius (zero-crossings), total water supply and the frequency of high wind speed are studied. Our results show that there are large climate gradients in Troms county and also in detected changes. In both focus areas, however, we find an increase in studied snow indices in present climate, while a strong decrease is expected in near and far future, particularly in low elevations where snow during winter might become a rarity by 2100. Heavy water supply is rather infrequent in the present climate of Troms, but we show that these events are likely to occur more often in all inland areas in the future. Although the risk of dry snow-related access disruptions might decrease, a warmer and wetter winter climate may increase the risk of wet-snow avalaches and slushflows. We find that zero-crossings, known to destabilize the snow pack and cause rockfall, have increased in most parts of Troms during the last decades, and a further increase is expected for inland regions in the future, while coastal regions can expect less zero-crossings. The higher risk of water and rainfall-induced hazards and more frequent freeze-thaw conditions calls for careful coordination of climate adaptation, cooperation between different sectors, as well as guidance and training of local authorities, especially in exposed and remote regions.

Description: This study presents an analysis of TROPOMI cloud heights as a proxy for volcanic plume heights in the presence of absorbing aerosols and sulfur dioxide for the 19 February 2018 eruption plume of the Sinabung volcano on Sumatra, Indonesia. Comparison with CALIPSO satellite data shows that all three TROPOMI cloud height data products based on oxygen absorption which are considered here (FRESCO, ROCINN, O22CLD) provide volcanic ash heights comparable to heights measured by CALIPSO for optically thick volcanic ash clouds. FRESCO and ROCINN heights are very similar with only differences for FRESCO cloud top heights above 14 km altitude. O22CLD cloud top heights unsurprisingly fall below those of FRESCO and ROCINN, as the O22CLD retrieval is less sensitive to cloud top heights above 10 km altitude. For optically thin volcanic ash clouds, i.e. when Earth’s surface or clouds at lower altitudes shine through the volcanic ash cloud, retrieved heights fall below the volcanic ash heights derived from CALIPSO data. Evaluation of corresponding Himawari geostationary volcanic ash height retrievals based on InfraRed (IR) brightness temperature differences (ΔBT) reveals that for this particular eruption the ΔBT volcanic ash signature – widely used for detection of volcanic ash in geostationary satellite data – changes to a ΔBT ice crystal signature for the part of the ash plume reaching the upper troposphere beyond 10 km altitude several hours after the start of the eruption and which TROPOMI clearly characterizes as volcanic (SO2 〉 1 DU and AAI 〉 4 or more conservatively SO2 〉 10). The presence of ice in volcanic ash clouds is known to prevent the detection of volcanic ash based on broadband geostationary satellite data. TROPOMI does not suffer from this effect, and can provide valuable and accurate information about volcanic ash clouds and ash top heights in cases where commonly used geostationary IR measurements of volcanic ash fail.

Description: Droughts continue to affect ecosystems, communities, and entire economies. Agriculture bears much of the impact, and in many countries it is the most heavily affected sector. Over the past decades, efforts have been made to assess drought risk at different spatial scales. Here, we present for the first time an integrated assessment of drought risk for both irrigated and rain-fed agricultural systems at the global scale. Composite hazard indicators were calculated for irrigated and rain-fed systems separately using different drought indices based on historical climate conditions (1980–2016). Exposure was analyzed for irrigated and non-irrigated crops. Vulnerability was assessed through a social-ecological systems perspective, using social-ecological susceptibility and lack of coping capacity indicators that were weighted by drought experts from around the world. The analysis shows that drought risk of rain-fed and irrigated agricultural systems displays heterogeneous pattern at the global level with higher risk for southeastern Europe, as well as northern and southern Africa. By providing information on the drivers and spatial patterns of drought risk in all dimensions of hazard, exposure, and vulnerability, the presented analysis can support the identification of tailored measures to reduce drought risk and increase the resilience of agricultural systems.

Description: Flooding is one of the main natural hazard in the world and causes huge economic and human impacts. Assessing the flood damage in the Mediterranean region is of great importance, especially because its large vulnerability to climate change. Most past floods affecting the region were caused by intense precipitation events, thus the analysis of the links between precipitation and flood damage is crucial. The main objective of this paper is to estimate changes in the probability of damaging flood events with a global warming of 1.5, 2 and 3 °C above preindustrial levels and taking into account different socioeconomic scenarios in two western Mediterranean regions, namely Catalonia and the Valencian Community. To do this, we analyse the relationship between heavy precipitation and flood damage estimates from insurance datasets in those two regions. We consider an ensemble of seven regional climate model simulations spanning the period 1976–2100 to evaluate precipitation changes and to drive a logistic model that links precipitation and flood damage estimates, and thus to derive statistics under present and future climates. Furthermore, we incorporate population projections based on 5 different socioeconomic scenarios. The results show a general increase in the probability of a damaging event for most of the cases and in both regions of study, with larger increments when higher warming is considered. Moreover, this increase is higher when both climate and population change are included. When population is considered, all the periods and models show a clearly higher increase in the probability of damaging events, which is statistically significant for most of the cases. Our findings highlight the need for limiting the global warming as much as possible, as well as the importance of including variables that consider change in both climate and socioeconomic conditions in the analysis of flood damage.

Description: Although many studies have explored the effect of teleconnection indicators on flood, few investigations have focused on the assessment of the expected damages resulted by flood under the El-Niño or La-Niña condition. Therefore, this study’s aim was to determine the effect of El-Niño on the expected flood damage in the Kan River basin, Iran. To determine the flood damage costs, first, the precipitation enhancement during El-Niño condition was estimated then using a probabilistic approach the inundation area was determined under 5, 10 and 50 year return periods. The results showed that El-Niño increases the precipitation amount up to 8.2 % and 31 % with 60 % and 90 % confidence level, respectively. Flood damage assessment using damage-elevation curves showed that the expected increase percentile in flood damage for smaller return periods, which is more frequent, is much more than that for larger return periods. In general, for the return periods of 5- and 10-year, 31 % increase in the precipitation would result in 2416 % and 239 % damage increase, respectively. However, for the 50-year rainfall this increase amount will be about 74 %. These results indicate the importance of small flood events in flood management planning during El-Niño.

Description: Comprehensive and sustainable landslide management, including identification of landslide susceptible areas, requires a lot of organisations and people to collaborate efficiently. Often, landslide management efforts are made after major triggering events only, such as hazard mitigations that applied after the 2015 Gorkha earthquake in Nepal. Next, to a lack of efficiency and continuity, there is also a lack of sharing of information and cooperation among stakeholders to cope with significant disaster events. There should be a system to allow easy update of landslide information after an event. For a variety of users of landslide information in Nepal, the availability and extraction of landslide data from the database are a vital requirement. In this study, we investigate the requirements to and propose a concept for a web-based Nepalese landslide information system (NELIS) that provides users with a platform to share the location of landslide events for the further collaborations. The system will be defined as a web-based geographic information system (GIS) that supports responsible organisations to address and manage different user requirements of people working with landslides, thereby improving the current state of landslide management in Nepal. The overall aim of this research is to propose a conceptual design of NELIS and to show the current status of the cooperation between involved stakeholders. A system like NELIS could benefit stakeholders involved in data collection and landslide management in their efforts to report and provide landslide information. Moreover, such a system would allow for detailed and structured landslide documentation and consequently provide valuable information for susceptibility, hazard, and risk mapping. For the reporting of landslides directly to the system, a web portal is proposed. Stakeholders who can contribute to the reporting of landslides are mostly local communities and schools. Based on field investigations, literature reviews and user interviews, the practical structure of the landslide database and a conceptual design for the NELIS platform is proposed.

Description: We have calculated a mean erosion of 1.3 mm caused by an individual storm event in March 2015 that impacted a large mountainous area of the southernmost Atacama Desert. The calculated erosion agrees with millennial erosion rates and with return time of high sediment discharge events previously reported in the study area. Here, we quantify for the first time the contribution of an individual extreme storm event to long-term erosion rates in the Atacama Desert. This is significant because erosion rates, related to high sediment discharge events in arid fluvial systems, are hard to measure with sediment load due the destruction of gauges by devastating flashfloods and thus have not been directly measured yet. During the March 2015 storm, debris flows were reported as the main sediment transport process. Erosion of gullies and channels are the main source of sediments that finally generate debris flows that reach the tributary junctions and the trunk valleys. The sediment yield to the tributary outlets strongly depends on the hydraulic capacity of catchments to store sediments in the drainage network between storms. Larger tributary catchments, high hydrological hierarchy, low topographic gradient and gentle slopes are the most susceptible catchments to generate debris flows that reach alluvial fans at any storm event from large debris volumes stored in the drainage network. Our findings better assess debris flow susceptibility of arid catchments, which is significant for the southernmost Atacama Desert valleys because human settlements and industries are mostly established in alluvial fans.

Description: Volcanic eruptions comprise one of the most important airborne hazards for aviation. Although significant events are rare, they have a very high impact. The current state of tools and abilities to mitigate aviation hazards associated with an assumed volcanic cloud was tested within an international demonstration exercise. Experts in the field assembled at the Schwarzenberg barracks in Salzburg, Austria, in order to simulate the sequence of procedures for the volcanic case scenario of an artificial eruption of Etna volcano in Italy. The scope of the exercise ranged from the detection of the assumed event to the issuance of early warnings. Volcanic emission concentration charts were generated applying modern ensemble techniques. The exercise products provided an important basis for decision making for aviation traffic management during a volcanic eruption crisis. By integrating the available wealth of data, observations and modelling results directly into a widely used flight planning software, it was demonstrated that route optimization measures could be implemented effectively. With timely and rather precise warnings available, the new tools and processes tested during the exercise demonstrated vividly that a vast majority of flights could be conducted despite a volcanic plume widely dispersed within a high-traffic airspace over Europe. The resulting number of flight cancellations was minimal.

Description: Using new high accuracy Light Detection and Ranging elevation data we generate coastal flooding maps for Norway. Thus far, we have mapped ~ 80 % of the coast, for which we currently have data of sufficient accuracy to perform our analysis. Although Norway is generally at low risk from sea-level rise largely owing to its steep topography, the maps presented here show that on local scales, many parts of the coast are potentially vulnerable to flooding. There is a considerable amount of infrastructure at risk along the relatively long and complicated coastline. Nationwide we identify a total area of 400 km2, 105,000 buildings, and 510 km of roads that are at risk of flooding from a 200 year storm-surge event at present. These numbers will increase to 610 km2, 137,000, and 1340 km with projected sea-level rise to 2090 (95th percentile of RCP8.5 as recommended in planning). We find that some of our results are likely biased high owing to erroneous mapping (at least for lower water levels close to the tidal datum which delineates the coastline). A comparison of control points from different terrain types indicates that the elevation model has a root mean square error of 0.26 m and is the largest source of uncertainty in our mapping method. The coastal flooding maps and associated statistics are freely available, and alongside the development of coastal climate services, will help communicate the risks of sea-level rise and storm surge to stakeholders. This will in turn aid coastal management and climate adaption work in Norway.

Description: Use of the Evapotranspiration based scheduling method is the most common one for irrigation programming in agriculture. There is no doubt that the estimation of the reference evapotranspiration (ETo) is a key factor in irrigated agriculture. However, the high cost and maintenance of agrometeorological stations and high number of sensors required to estimate it creates a non-plausible situation especially in rural areas. For this reason the estimation of ETo using air temperature, in places where wind speed, solar radiation and air humidity data are not readily available, is particularly attractive. Daily data record of 49 stations distributed over Duero basin (Spain), for the period 2000–2018, were used for estimation of ETo based on seven models against Penman–Monteith FAO 56 with temporal (annual or seasonal) and spatial perspective. Two Hargreaves–Samani models (HS), with and without calibration, and five Penman–Monteith temperature models (PMT) were used in this study. The results show that the models' performance changes considerably depending on whether the scale is annual or seasonal. The performance of the seven models was acceptable from an annual perspective (R2 〉 0.91, NSE 〉 0.88, MAE 

Description: In the Eastern Alps no previous research focused on the impact of wildfires on the occurrence of rockfalls. The investigation of wildfires and post-wildfire rockfalls gains new importance with respect to changes in weather extremes and rapid social developments such as population growths and tourism. The present work describes a wildfire that occurred in August 2018 in a famous world-heritage site in Austria. Indicators of fire severity and rockfall occurrence during and after the fire are described.

Description: This study aims at evaluating the performances of flash flood forecasts issued from deterministic and ensemble meteorological prognostic systems. The hydro-meteorological modeling chain includes the Weather Research and Forecasting model (WRF) forcing the rainfall-runoff model MARINE dedicated to flash flood. Two distinct ensemble prediction systems accounting for (i) perturbed initial and lateral boundary conditions of the meteorological state and (ii) mesoscale model physical parameterizations, have been implemented on the Agly catchment of the Eastern Pyrenees with three sub-catchments exhibiting different rainfall regimes. Different evaluations of the performance of the hydrometeorological strategies have been performed: (i) verification of short-range ensemble prediction systems and corresponding stream flow forecasts, for a better understanding of how forecasts behave, (ii) usual measures derived from a contingency table approach, to test an alert threshold exceedance, and (iii) overall evaluation of the hydro-meteorological chain using the Continuous Rank Probability Score, for a general quantification of the ensemble performances. Results show that the overall discharge forecast is improved by both ensemble strategies with respect to the deterministic forecast. Threshold exceedance detections for flood warning also benefit from large hydro-meteorological ensemble spread. There are no substantial differences between both ensemble strategies on these test cases in terms both of the issuance of flood warnings and the overall performances, suggesting that both sources of external-scale uncertainty are important to take into account.

Description: Landslides triggered by rainfall are very common phenomena in complex tropical environments such as the Colombian Andes, one of the regions most affected by landslides every year. Currently in Colombia, physically based methods for landslide hazard mapping are mandatory for land use planning in urban areas. In this work, we perform probabilistic analyses with r.slope.stability, a spatially distributed, physically based model for landslide susceptibility analysis, available as an open-source tool coupled to GRASS GIS. This model considers alternatively the infinite slope stability model or the 2.5D geometry of shallow planar and deep-seated landslides with ellipsoidal or truncated failure surfaces. We test the model in the La Arenosa catchment, northern Colombian Andes. The results are compared to those yielded with the corresponding deterministic analyses and with other physically based models applied in the same catchment. Finally, the model results are evaluated against a landslide inventory using a confusion matrix and Receiver Operating Characteristic (ROC) analysis. The model performs reasonably well, the infinite slope stability model showing a better performance. The outcomes are, however, rather conservative, pointing to possible challenges with regard to the geotechnical and geo-hydraulic parameterization. The results also highlight the importance to perform probabilistic instead of – or in addition to – deterministic slope stability analyses.

Description: After confirming that impoundment of large reservoirs could cause earthquakes worldwide, studies on reservoir-triggered seismicity (RTS) have had a considerable scientific incentive. Most of the studies determined that the vertical load increase due to reservoir load, and the reduction of effective effort due to the increase in pore pressure, can modify the stress regime in the reservoir region, possibly triggering earthquakes. In addition, the RTS is conditioned by several factors such as pre-existing tectonic stresses, reservoir size/weight, area-specific geological and hydromechanical conditions, constructive interaction between the orientation of seismotectonic forces, and additional load caused by the reservoir. One of the major challenges for studying RTS is to identify and correlate the factors in the area of influence of the reservoir, capable of influencing the RTS process itself. To assist the research, it was created a spatial seismicity-triggered reservoir database (BDSDR) based on the specifications of the national spatial data infrastructure (INDE), for gathering data pertinent to the RTS study in the area of reservoirs. In this context, this work presents the procedures and results found in the data processing of seismotectonic factors (dam height, reservoir volume, geology, and seismicity level) and compared with the dams that triggered earthquakes and the Brazilian dam catalog, which was then updated from 26 to 30 cases. The results indicate that the occurrence of RTS increases significantly with dam height since dams less than 50 m high cause only 2 % of earthquakes while those higher than 100 m cause about 54 %. The reservoir volume also plays a role and it was estimated that RTS occurrence requires a limiting minimum value of 1 × 10−4 km3. There was no clear correlation between the geology and geological provinces with RTS. The delayed response time of the reservoirs represents 43 % of the total, that is, almost half of them have hydraulic behavior. The highest magnitude, 4.2, was observed for an event that occurred in a reservoir with a volume greater than 10−3 km3. As a practical result to assist the analysis by the general community, the web viewer RISBRA (Reservoir Induced Seismicity in Brazil) was developed to serve as an interactive platform for BDSDR data.

Description: This study discusses the correlation between the fractal of spatial epicentre distribution of aftershock (D2) and active fault (D0) in the Sumatra region. We identified 15 earthquakes in this region that were followed by aftershock cluster and related to the Sumatra Fault Zone or Southern Andaman West Fault. The spatial epicentre distribution of the aftershock was estimated by using two-point correlation integral and the D2 values found were varying from 1.03 ± 0.03 to 1.68 ± 0.08. We estimated the fractal dimension of the active fault by using Box–Counting Method and found that the variation of D0 values in the range of 0.95 ± 0.03 to 1.16 ± 0.01. Positive correlation was found in this study and two patterns were identified that had similar slope with different intercept. However, there was also a correlation that had steeper slope. The steeper slope was related to earthquake doublet mechanism that could generate more random spatial distribution of the aftershock in the fault system.

Description: A fundamental feature of any Earthquake Early Warning System is the ability of rapidly broadcast earthquake information to a wide audience of potential end users and stakeholders, in an intuitive, customizable way. Smartphones and other mobile devices are nowadays continuously connected to the internet and represent the ideal tools for earthquake alerts dissemination, to inform a large number of users about the potential damaging shaking of an impending earthquake. Here we present a mobile App (named ISNet EWApp) for Android devices which can receive the alerts generated by a network-based Early Warning system. Specifically, the app receives the earthquake alerts generated by the PRESTo EWS, which is currently running on the accelerometric stations of the Irpinia Seismic Network (ISNet) in Southern Italy. In the absence of alerts, the EWApp displays the standard bulletin of seismic events occurred within the network. In the event of a relevant earthquake, instead, the app has a dedicated module to predict the expected ground shaking intensity and the available lead-time at the user position and to provide customized messages to inform the user about the proper reaction during the alert. We first present the architecture of both network-based system and EWApp, and then and describe its essential operational modes. The app is designed in a way that is easily exportable to any other network-based early warning system.

Description: The region of southern Africa (SA) has a fragile food economy and is vulnerable to frequent droughts. In 2015–2016, an El Niño-driven drought resulted in major maize production shortfalls, food price increases, and livelihood disruptions that pushed 29 million people into severe food insecurity. Interventions to mitigate food insecurity impacts require early warning of droughts – preferably as early as possible before the harvest season (typically, starting in April) and lean season (typically, starting in November). Hydrologic monitoring and forecasting systems provide a unique opportunity to support early warning efforts, since they can provide regular updates on available rootzone soil moisture (RZSM), a critical variable for crop yield, and provide forecasts of RZSM by combining the estimates of antecedent soil moisture conditions with climate forecasts. For SA, this study documents the predictive capabilities of a recently developed NASA Hydrological Forecasting and Analysis System (NHyFAS). The NHyFAS system's ability to forecast and monitor the 2015/2016 drought event is evaluated. The system's capacity to explain interannual variations in regional crop yield and identify below-normal crop yield events is also evaluated. Results show that the NHyFAS products would have identified the regional severe drought event, which peaked during December–February of 2015/2016, at least as early as 1 November 2015. Next, it is shown that February RZSM forecasts produced as early as 1 November (4–5 months before the start of harvest and about a year before the start of the next lean season) correlate fairly well with regional crop yields (r = 0.49). The February RZSM monitoring product, available in early March, correlates with the regional crop yield with higher skill (r = 0.79). It is also found that when the February RZSM forecast produced on November 1 is indicated to be in the lowest tercile, the detrended regional crop yield is below normal about two-thirds (significance level ~ 86 %) of the time. Furthermore, when the February RZSM monitoring product (available in early March) indicates a lowest tercile value, the crop yield is always below normal, at least over the sample years considered. These results indicate that the NHyFAS products can effectively support food insecurity early warning in the SA region.

Description: Impact databases development and application for risk analysis and management promotes the usage of self-learning computer systems with elements of artificial intelligence. Such systems learning could be successful when the databases store the complete information about each event, parameters of the simulation models, the range of its application and residual errors. Each new description included in the database could increase the reliability of the results obtained with application of simulation models. The calibration of mathematical models is the first step to self-learning of automated systems. The article describes the events' database structure, and examples of calibrated computer models as applied to the impact of expected emergencies and risk indicators assessment. Examples of database statistics usage in order to rank the subjects of the Russian Federation by the frequency of emergencies of different character, as well as risk indicators are given.

Description: In this study we analyse the role of climate change in the forest fires that raged through large parts of Sweden in the summer of 2018 from a meteorological perspective. This is done by studying the Canadian Fire Weather Index (FWI) based on sub-daily data, both in reanalysis datasets (ERA-Interim, ERA5, JMA55 and MERRA2) and three large ensemble climate models (EC-Earth, W@H and CESM) simulations. The FWI based on reanalysis correlates well with observed area burned in summer (r = 0.6 to 0.8). We find that the maximum forest fire risk in July 2018 had return times of ∼ 24 years for Southern and Northern Sweden. Further, we find a negative trend of the FWI for Southern Sweden over the 1979 to 2017 time period, yielding a decreasing risk of such an event solely based on reanalysis data. However, given the short observational record, large uncertainty between the reanalysis products and large natural variability of the FWI we cannot draw robust conclusions from reanalysis data. The 3 large-ensembles with climate models on the other hand point to a roughly 1.1 times increased risk for such events in the current climate relative to pre-industrial climate. For a future climate (2C warming) we find a roughly 2 times increased risk for such events relative to pre-industrial climate. The increased fire weather risk is mainly attributed to the increase in temperature. The other main factor, precipitation during summer months, is projected to increase for Northern Sweden, and decrease for Southern Sweden. We however do not find a clear change of prolonged dry periods in summer months that could explain the increased fire weather risk. In summary, we find a small but positive role of global warming up to now in the 2018 forest fires in Sweden, but a more robust increase in the risk for such events in the future.

Description: After an earthquake, efficiently and accurately acquiring information about damaged buildings can help reduce casualties. Earth observation data have been widely used to map affected areas after earthquakes. However, accurate post-earthquake assessment results are needed to manage recovery and reconstruction and estimate economic losses. In this paper, for quantification and precision purposes, information on earthquake-induced building damage is extracted using multi-source remote sensing images collected after an earthquake. The multi-source remote sensing data include optical data, synthetic aperture radar (SAR) data, and digital surface model (DSM) data generated by interpolating light detection and ranging (LiDAR) point cloud data. Features that describe texture, colour, and geometry are included in our analysis. The feature analysis is carried out according to the rough set theory to further determine the feature parameters. A logistic regression model (LRM) is employed to find the optimal fitting function to describe the relationship between the occurrence and absence of destroyed buildings within an individual object. In our experiment, old Beichuan County, China, the area most devastated by the Wenchuan earthquake on May 12, 2008, is used to test the proposed hypothesis. Through comparison with a ground survey, the experimental results show that the detection accuracy of the proposed method is 94.2 %; the area under the receiver operating characteristic (ROC) curve is 0.827. The efficiency of the proposed method is demonstrated using 6 modes of data combination acquired from the same area in old Beichuan County. The approach is one of the first attempts to extract damaged buildings through the fusion of three types of data with different features. The approach addresses multivariate regression methodologies and compares the potentials of different features for application in the field of damage detection.

Description: The two primary causes of surf zone injuries (SZIs) worldwide, including fatal drowning and severe spinal injuries, are rip currents (rips) and shore-break waves. SZIs also result from surfing and body boarding activity. In this paper we address the primary environmental controls on SZIs along the high-energy meso-macrotidal surf beach coast of SW France. A total of 2523 SZIs recorded by lifeguards over 186 sample days during the summers of 2007, 2009 and 2015 were combined with measured and/or hindcast weather, wave, tide and beach morphology data. All SZIs occurred disproportionately on warm sunny days with low wind likely because of increased beachgoer numbers and hazard exposure. Relationships were strongest for shore break and rip related SZIs and weakest for surfing related SZIs, the latter being also unaffected by tidal stage or range. Therefore the analysis focussed on bathers. Shore-break related SZIs disproportionately occur during shore-normal incident waves with average to below-average wave height (significant wave height Hs = 0.75–1.5 m) and around higher water levels and large tide range when waves break on the steepest section of the beach. In contrast, rip related drownings occur disproportionally near neap low tide, coinciding with maximized channel rip flow activity, under shore-normal incident waves with Hs 〉 1.25 m and periods mean wave period longer than 5 s. Additional drowning incidents occurred at spring high tide, presumably due to small-scale swash rips. The composite wave and tide parameters proposed by Scott et al. (2014) are key controlling factors determining SZI occurrence, although the risk ranges are not necessarily transferable to all sites. Summer beach and surf zone morphology is highly interannually variable, which is critical to SZI patterns. The upper beach slope can vary from 0.06 to 0.18 between summers, resulting in low and high shore-break related SZIs, respectively. Summers with coast-wide highly (weakly) developed rip channels also result in widespread (scarce) rip related drowning incidents. With life risk defined in terms of the number of people exposed to life threatening hazards at a beach, the ability of morphodynamic models to simulate primary beach morphology characteristics a few weeks/months in advance is therefore of paramount importance to predict the primary surf-zone life risks along this coast.