ALBERT

Beschreibung: 〈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.

Beschreibung: 〈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.

Beschreibung: 〈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.

Beschreibung: 〈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.

Beschreibung: 〈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.

Beschreibung: 〈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.

Beschreibung: 〈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.

Beschreibung: 〈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.

Beschreibung: 〈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.

Beschreibung: 〈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.

Beschreibung: 〈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.

Beschreibung: 〈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.

Beschreibung: 〈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.

Beschreibung: 〈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.

Beschreibung: 〈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.

Beschreibung: 〈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.

Beschreibung: 〈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.

Beschreibung: 〈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.

Beschreibung: 〈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).

Beschreibung: 〈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.

Beschreibung: 〈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.

Beschreibung: 〈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.

Beschreibung: 〈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.

Beschreibung: 〈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.

Beschreibung: 〈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.

Beschreibung: 〈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.

Beschreibung: 〈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〉

Beschreibung: 〈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.

Beschreibung: 〈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.

Beschreibung: 〈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.

Beschreibung: 〈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.

Beschreibung: 〈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〉

Beschreibung: 〈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.

Beschreibung: 〈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〉

Beschreibung: 〈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.

Beschreibung: 〈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.

Beschreibung: 〈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.

Beschreibung: 〈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.

Beschreibung: 〈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.

Beschreibung: 〈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.

Beschreibung: 〈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〉

Beschreibung: 〈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.

Beschreibung: 〈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.

Beschreibung: 〈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〉

Beschreibung: 〈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.

Beschreibung: 〈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.

Beschreibung: 〈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.

Beschreibung: 〈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.

Beschreibung: 〈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.

Beschreibung: 〈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.

Beschreibung: 〈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.

Beschreibung: 〈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〉

Beschreibung: 〈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.

Beschreibung: 〈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.

Beschreibung: 〈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〉.

Beschreibung: 〈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.

Beschreibung: 〈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.

Beschreibung: 〈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.

Beschreibung: 〈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.

Beschreibung: 〈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〉

Beschreibung: The estimate of an individual wave run-up is especially important for tsunami warning and risk assessment, as it allows for evaluating the inundation area. Here, as a model of tsunamis, we use the long single wave of positive polarity. The period of such a wave is rather long, which makes it different from the famous Korteweg–de Vries soliton. This wave nonlinearly deforms during its propagation in the ocean, which results in a steep wave front formation. Situations in which waves approach the coast with a steep front are often observed during large tsunamis, e.g. the 2004 Indian Ocean and 2011 Tohoku tsunamis. Here we study the nonlinear deformation and run-up of long single waves of positive polarity in the conjoined water basin, which consists of the constant depth section and a plane beach. The work is performed numerically and analytically in the framework of the nonlinear shallow-water theory. Analytically, wave propagation along the constant depth section and its run up on a beach are considered independently without taking into account wave interaction with the toe of the bottom slope. The propagation along the bottom of constant depth is described by the Riemann wave, while the wave run-up on a plane beach is calculated using rigorous analytical solutions of the nonlinear shallow-water theory following the Carrier–Greenspan approach. Numerically, we use the finite-volume method with the second-order UNO2 reconstruction in space and the third-order Runge–Kutta scheme with locally adaptive time steps. During wave propagation along the constant depth section, the wave becomes asymmetric with a steep wave front. It is shown that the maximum run-up height depends on the front steepness of the incoming wave approaching the toe of the bottom slope. The corresponding formula for maximum run-up height, which takes into account the wave front steepness, is proposed.

Beschreibung: The Italian Tsunami Alert Centre of the Istituto Nazionale di Geofisica e Vulcanologia (Centro di Allerta Tsunami, hereinafter CAT-INGV) supported a computer-assisted telephone interview (CATI) survey to investigate tsunami risk perception in two pilot regions of southern Italy. The survey was carried out on a stratified sample of 1021 interviewees representing about 3.2 million people living in 183 coastal municipalities of the two regions, namely Calabria and Apulia. The main goal of this research is to verify whether and how people's perception of tsunami hazard compares to the results of (PTHA) – probabilistic tsunami hazard assessment (TSUMAPS-NEAM project; Basili et al., 2018). As shown by the results of this project, both investigated regions are characterised by high tsunami hazard. Nonetheless, the long return time of such events could lead people to consider the occurrence of a tsunami in the Mediterranean Sea to be very unlikely. The survey results reveal that people's risk perception is low: for almost half of the whole sample the occurrence of a tsunami in the Mediterranean Sea is considered quite unlikely, with a clear difference between Apulia and Calabria. In the latter region the risk perception is much higher than in the former, probably due to the shorter time elapsed since the last event. Also, belonging to different coastal areas1 appears to have a significant influence on the way tsunami hazard is conceived, having a stronger effect on risk characterisation: the interviewees of Tyrrhenian Calabria are indeed more likely to associate tsunami risk with volcanoes than the Ionian citizens. This is coherent considering the presence of active volcanoes and related tsunami precedents in the Tyrrhenian. Television emerged as the most relevant source of knowledge for almost 90 % of the sample, and the influence of media also results in the way tsunami risk is characterised. In particular, the survey showed that people's perception and understanding of tsunamis are affected by media accounts of large events, such as the 2004 Sumatra and the 2011 Japan tsunamis. At the same time, it is evident that the risk posed by smaller events is underrated. Furthermore, the survey's results show that the word “tsunami” occupies a different semantic space in comparison to the Italian traditional headword maremoto, with differences among sample strata. In other words, the same physical phenomenon would be understood in two different ways by younger, educated people and elders with a low education level. The results of this study, although limited to two regions, provide a first assessment of tsunami risk perception in Italy, also entailing important consequences for both risk communication practice and mitigation policies.

Beschreibung: 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 growth 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.

Beschreibung: A magnitude 7.5 earthquake occurred on 28 September 2018 at 10:02:43 UTC near the city of Palu on the Indonesian island of Sulawesi. It was a shallow, strike-slip earthquake with a rupture extending to a length of about 150 km and reaching the surface. Moreover, this earthquake was identified as one of very few events having a super-shear rupture speed. Clear and long-lasting infrasound signatures related to this event were observed by four infrasound arrays of the International Monitoring System of the Comprehensive Nuclear-Test-Ban Treaty Organization as well as by one national infrasound station in Singapore. Although these infrasound stations SING (Singapore), I39PW (Palau), I07AU (Australia), I40PG (Papua New Guinea) and I30JP (Japan) are located at large distances of between 1800 and 4500 km from the earthquake's epicentral region, the observed infrasound signals associated with this event were intense, including both seismic and acoustic arrivals. A detailed study of the event-related infrasound observations and the potential infrasound generation mechanisms is presented, covering range-dependent infrasound transmission loss and propagation modeling and characterization of the atmospheric background conditions, as well as identification of the regions of seismoacoustic activity by applying a back-projection method from the infrasound receivers to potential source regions. This back projection of infrasonic arrivals allows one to estimate that the main infrasound source region for the Sulawesi earthquake is related to the extended rupture zone and the nearby topography. This estimation and a comparison to other super-shear as well as large regional earthquakes identify no clear connection between the earthquake's super-shear nature and the strong infrasound emission.

Beschreibung: The site amplification factor was usually considered to be scalar values, such as amplification of peak ground acceleration or peak ground velocity, or increments of seismic intensity in the earthquake early warning (EEW) system or seismic-intensity repaid report system. This paper focuses on evaluating an infinite impulse recursive filter method that could produce frequency-dependent site amplification and compare the performance of the scalar-value method with the infinite impulse recursive filter method. A large number of strong motion data of IBRH10 and IBRH19 of the Kiban Kyoshin network (KiK-net) triggered in more than 1000 earthquakes from 2004 to 2012 were selected carefully and used to obtain the relative site amplification ratio; we model the relative site amplification factor with a casual filter. Then we make a simulation from the borehole to the surface and also simulate from the front-detection station to the far-field station. Compared to different simulation cases, it can easily be found that this method could produce different amplification factors for different earthquakes and could reflect the frequency-dependent nature of site amplification. Through these simulations between two stations, we can find that the frequency-dependent correction for site amplification shows better performance than the amplification factor relative to velocity (ARV) method and station correction method. It also shows better performance than the average level and the highest level of the Japan Meteorological Agency (JMA) earthquake early warning system in ground motion prediction. Some cases in which simulation did not work very well were also found; possible reasons and problems were analyzed and addressed. This method pays attention to the amplitude and ignores the phase characteristics; this problem may be improved by the seismic-interferometry method. Frequency-dependent correction for site amplification in the time domain highly improves the accuracy of predicting ground motion in real time.

Beschreibung: Flooding is one of the main natural hazards in the world and causes huge economic and human impacts. Assessing the flood damage in the Mediterranean region is of great importance, especially because of 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 global warming of 1.5, 2 and 3 ∘C above pre-industrial 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 (RCM) simulations spanning the period 1976–2100 to evaluate precipitation changes and to drive a logistic model that links precipitation and flood-damage estimates, thus deriving statistics under present and future climates. Furthermore, we incorporate population projections based on five 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 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.

Beschreibung: This research studied the spatiotemporal variation in methane in the middle to 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 5.12×10-8, compared to the average increase of 1.18×10-8 in the previous 5 years. The absolute local index of change of the environment (ALICE) and differential value (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 8 d 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 that the value was positive. The gradient value is negative during coseismic or post-seismic 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 micro-fracture 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.

Beschreibung: Extreme weather events, such as droughts, have been increasingly affecting the agricultural sector, causing several socio-economic consequences. The growing economy requires improved assessments of drought-related impacts in agriculture, particularly under a climate that is getting drier and warmer. This work proposes a probabilistic model that is intended to contribute to the agricultural drought risk management in rainfed cropping systems. Our methodology is based on a bivariate copula approach using elliptical and Archimedean copulas, the application of which is quite recent in agrometeorological studies. In this work we use copulas to model joint probability distributions describing the amount of dependence between drought conditions and crop yield anomalies. Afterwards, we use the established copula models to simulate pairs of yield anomalies and drought hazard, preserving their dependence structure to further estimate the probability of crop loss. In the first step, we analyse the probability of crop loss without distinguishing the class of drought, and in the second step we compare the probability of crop loss under drought and non-drought conditions. The results indicate that, in general, Archimedean copulas provide the best statistical fits of the joint probability distributions, suggesting a dependence among extreme values of rainfed cereal yield anomalies and drought indicators. Moreover, the estimated conditional probabilities suggest that when drought conditions are below moderate thresholds, the risk of crop loss increases between 32.53 % (cluster 1) and 32.6 % (cluster 2) in the case of wheat and between 31.63 % (cluster 2) and 55.55 % (cluster 2) in the case of barley. From an operational point of view, the results aim to contribute to the decision-making process in agricultural practices.

Beschreibung: An earthquake with a magnitude of Mw=7.5 that occurred in Sulawesi, Indonesia, on 28 September 2018 triggered liquefaction and tsunamis that caused severe damage and many casualties. This paper reports the results of a post-tsunami field survey conducted by a team with members from Indonesia and Taiwan that began 13 d after the earthquake. The main purpose of this survey was to measure the run-up of tsunami waves and inundation and observe the damage caused by the tsunami. Measurements were made in 18 selected sites, most in Palu Bay. The survey results show that the run-up height and inundation distance reached 10.7 m in Tondo and 488 m in Layana. Inundation depths of 2 to 4 m were common at most sites and the highest was 8.4 m in Taipa. The arrival times of the tsunami waves were quite short and different for each site, typically about 3–8 min from the time of the main earthquake event. This study also describes the damage to buildings and infrastructure and coastal landslides.

Beschreibung: Aridity indices have been widely used in climate classification. However, there is not enough evidence for their ability in identifying the multiple climate types in areas with complex topography and landscape, especially in those areas with a transition climate. This study compares a traditional meteorological aridity index (AI), defined as the ratio of precipitation (P) to potential evapotranspiration (PET), with a hydrological aridity index, the evaporative stress index (ESI) defined as the ratio of actual evapotranspiration (AET) to PET in the Heihe River Basin (HRB) of arid northwestern China. PET was estimated using the Penman–Monteith and Hamon methods. The aridity indices were calculated using the high-resolution climate data simulated with a regional climate model for the period of 1980–2010. The climate classified by AI shows a climate type for the upper basin and a second type for the middle and lower basin, while three different climate types are found using ESI, each for one river basin, indicating that only ESI is able to identify a transition climate zone in the middle basin. The difference between the two indices is also seen in the interannual variability and extreme dry/wet events. The magnitude of variability in the middle basin is close to that in the lower basin for AI, but different for ESI. AI had a larger magnitude of the relative interannual variability and a greater decreasing rate from 1980 to 2010 than ESI, suggesting the role of local hydrological processes in moderating extreme climate events. Thus, the hydrological aridity index is better than the meteorological aridity index for climate classification in the arid Heihe River Basin.

Beschreibung: Hurricanes, as one of the most devastating natural hazards, have posed a great threat to people in coastal areas. A better understanding of the spatiotemporal dynamics of human settlement in hurricane-prone areas largely benefits sustainable development. This study uses the nighttime light (NTL) data from the Defense Meteorological Satellite Program's Operational Linescan System (DMSP/OLS) to examine human settlement development in areas with different levels of hurricane proneness from 1992 to 2013. The DMSP/OLS NTL data from six satellites were intercalibrated and desaturated with the Advanced Very High Resolution Radiometer (AVHRR) and Moderate Resolution Imaging Spectroradiometer (MODIS) optical imagery to derive the Vegetation Adjusted NTL Urban Index (VANUI), a popular index that quantifies human settlement intensity. The derived VANUI time series was examined with the Mann–Kendall test and Theil–Sen test to identify significant spatiotemporal trends. To link the VANUI product to hurricane impacts, four hurricane-prone zones were extracted to represent different levels of hurricane proneness. Aside from geographic division, a wind-speed-weighted track density function was developed and applied to historical storm tracks which originated in the North Atlantic Basin to better categorize the four levels of hurricane proneness. Spatiotemporal patterns of human settlement in the four zones were finally analyzed. The results clearly exhibit a north–south and inland–coastal discrepancy of human settlement dynamics. This study also reveals that both the zonal extent and zonal increase rate of human settlement positively correlate with hurricane proneness levels. The intensified human settlement in high hurricane-exposure zones deserves further attention for coastal resilience.

Beschreibung: Dam safety is increasingly subjected to the influence of climate change. Its impacts must be assessed through the integration of the various effects acting on each aspect, considering their interdependencies, rather than just a simple accumulation of separate impacts. This serves as a dam safety management supporting tool to assess the vulnerability of the dam to climate change and to define adaptation strategies under an evolutive dam failure risk management framework. This article presents a comprehensive quantitative assessment of the impacts of climate change on the safety of a Spanish dam under hydrological scenarios, integrating the various projected effects acting on each component of the risk, from the input hydrology to the consequences of the outflow hydrograph. In particular, the results of 21 regional climate models encompassing three Representative Concentration Pathways (RCP2.6, RCP4.5 and RCP8.5) have been used to calculate the risk evolution of the dam until the end of the 21st century. Results show a progressive deterioration of the dam failure risk, for most of the cases contemplated, especially for the RCP2.6 and RCP4.5 scenarios. Moreover, the individual analysis of each risk component shows that the alteration of the expected inflows has the greater influence on the final risk. The approach followed in this paper can serve as a useful guidebook for dam owners and dam safety practitioners in the analysis of other study cases.

Beschreibung: Remote sensing analysis is routinely used to map flooding extent either retrospectively or in near-real time. For flood emergency response, remote-sensing-based flood mapping is highly valuable as it can offer continued observational information about the flood extent over large geographical domains. Information about the floodwater depth across the inundated domain is important for damage assessment, rescue, and prioritizing of relief resource allocation, but cannot be readily estimated from remote sensing analysis. The Floodwater Depth Estimation Tool (FwDET) was developed to augment remote sensing analysis by calculating water depth based solely on an inundation map with an associated digital elevation model (DEM). The tool was shown to be accurate and was used in flood response activations by the Global Flood Partnership. Here we present a new version of the tool, FwDET v2.0, which enables water depth estimation for coastal flooding. FwDET v2.0 features a new flood boundary identification scheme which accounts for the lack of confinement of coastal flood domains at the shoreline. A new algorithm is used to calculate the local floodwater elevation for each cell, which improves the tool's runtime by a factor of 15 and alleviates inaccurate local boundary assignment across permanent water bodies. FwDET v2.0 is evaluated against physically based hydrodynamic simulations in both riverine and coastal case studies. The results show good correspondence, with an average difference of 0.18 and 0.31 m for the coastal (using a 1 m DEM) and riverine (using a 10 m DEM) case studies, respectively. A FwDET v2.0 application of using remote-sensing-derived flood maps is presented for three case studies. These case studies showcase FwDET v2.0 ability to efficiently provide a synoptic assessment of floodwater. Limitations include challenges in obtaining high-resolution DEMs and increases in uncertainty when applied for highly fragmented flood inundation domains.

Beschreibung: Rockfall is a complex natural process that can present risks to the effective operation of infrastructure in mountainous terrain. Remote sensing tools and techniques are rapidly becoming the state of the practice in the characterization, monitoring and management of these geohazards. The aim of this study is to address the methods and implications of how the dimensions of three-dimensional rockfall objects, derived from sequential terrestrial laser scans (TLSs), are measured. Previous approaches are reviewed, and two new methods are introduced in an attempt to standardize the process. The approaches are applied to a set of synthetic rockfall objects generated in the open-source software package Blender. Fifty rockfall events derived from sequential TLS monitoring in the White Canyon, British Columbia, Canada, are used to demonstrate the application of the proposed algorithms. This study illustrates that the method used to calculate the rockfall dimensions has a significant impact on how the shape of a rockfall object is classified. This has implications for rockfall modelling as the block shape is known to influence rockfall runout.

Beschreibung: In the context of sustainable agricultural management, drought monitoring plays a crucial role in 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 in frequency of these extreme events are expected in a very near future. Therefore, the quantitative assessment of the natural-ecosystem 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 adaptive 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 indices and soil characterization variables. A comparison between the PCA-based method and a variance 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 in certain vulnerability classes. However, the PCA method has some advantages over the variance method, namely the ability to identify the sign of the indicators, not having to use the indicator–component subjective relationship, and not needing to calculate weights. Furthermore, the PCA method is fully statistical and presents results according to prior knowledge of the region and the data used.

Beschreibung: This study aimed to develop a risk-based approach for determining control areas to manage non-point source pollution, developing a framework to prioritize catchments by considering the characteristics of polluted runoff from non-point sources. The best management, decision-making, and scientific approaches, such as the technique for order of preference by similarity to ideal solution (TOPSIS) and the Delphi technique, are required for the designation of control areas and the application of the best management practices to the control areas. Multi-criteria decision-making (MCDM) methods can handle the diversity and complexity of non-point source pollution. The Delphi technique was employed for selecting the assessment criteria/sub-criteria and determining their weights. Sub-criteria for each catchment unit were scored with either a quantitative or qualitative scale. All non-point pollution sources in mainland Republic of Korea were included, with the exception of a few islands, with catchment prioritization and pollution vulnerability evaluations shown as thematic maps. This study contributes to the field by developing a new risk-based approach for ranking and prioritizing catchments; this provides valuable information for the Ministry of Environment to use to identify control areas and manage non-point source pollution.

Beschreibung: Flood maps are needed for emergency response, research, and planning. The Height Above Nearest Drainage (HAND) technique is a low-complexity, terrain-based approach for inundation mapping using elevation data, discharge–height relationships, and streamflow inputs. The recent operational capacities of the NOAA National Water Model (NWM) and preprocessed HAND products from the University of Texas offer an operational framework for real-time and forecast flood guidance across the US. In this study, we evaluate the integrated National Water Model –Height Above Nearest Drainage (NWM–HAND) flood mapping approach using 28 remotely sensed inundation maps and 54 reach-level catchments. The results show the NWM–HAND method tends to underpredict inundated cells in 4th-order and lower-order reaches but does better with a slight tendency to overpredict in high-order reaches. An evaluation of the roughness coefficient used in the production of synthetic rating curves suggests it is the most important parameter for correcting these errors. Persistent inaccuracies do occur when NWM streamflow predictions are substantially biased (〉60 % mean absolute error between NWM and observed streamflow) and in regions of low relief. Overall, the NWM–HAND method does not accurately capture inundated cells but is quite capable of highlighting regions likely to be at risk in 4th-order streams and higher. While NWM–HAND should be used with caution when identifying flood boundaries or making decisions of whether a cell is dry or wet, its applicability as a high-level guidance tool along larger rivers is noteworthy.

Beschreibung: Parametric wind profiles are commonly applied in a number of engineering applications for the generation of tropical cyclone (TC) wind and pressure fields. Nevertheless, existing formulations for computing wind fields often lack the required accuracy when the TC geometry is not known. This may affect the accuracy of the computed impacts generated by these winds. In this paper, empirical stochastic relationships are derived to describe two important parameters affecting the TC geometry: radius of maximum winds (RMW) and the radius of gale-force winds (ΔAR35). These relationships are formulated using best-track data (BTD) for all seven ocean basins (Atlantic; S, NW, and NE Pacific; and N, SW, and SE Indian oceans). This makes it possible to (a) estimate RMW and ΔAR35 when these properties are not known and (b) generate improved parametric wind fields for all oceanic basins. Validation results show how the proposed relationships allow the TC geometry to be represented with higher accuracy than when using relationships available from literature. Outer wind speeds can be reproduced well by the commonly used Holland wind profile when calibrated using information either from best-track data or from the proposed relationships. The scripts to compute the TC geometry and the outer wind speed are freely available via the following URL: https://bit.ly/2k9py1J (last access: October 2019).

Beschreibung: Rockfall presents an ongoing challenge to the safe operation of transportation infrastructure, creating hazardous conditions which can result in damage to roads and railways, as well as loss of life. Rockfall risk assessment frameworks often involve the determination of rockfall runout in an attempt to understand the likelihood that rockfall debris will reach an element at risk. Rockfall modelling programs which simulate the trajectory of rockfall material are one method commonly used to assess potential runout. This study aims to demonstrate the effectiveness of a rockfall simulation prototype which uses the Unity 3D game engine. The technique is capable of simulating rockfall events comprised of many mobile fragments, a limitation of many industry standard rockfall modelling programs. Five fragmental rockfalls were simulated using the technique, with slope and rockfall geometries constructed from high-resolution terrestrial laser scans. Simulated change detection was produced for each of the events and compared to the actual change detection results for each rockfall as a basis for testing model performance. In each case the simulated change detection results aligned well with the actual observed change in terms of location and magnitude. An example of how the technique could be used to support the design of rockfall catchment ditches is shown. Suggestions are made for future development of the simulation technique with a focus on better informing simulated rockfall fragment size and the timing of fragmentation.

Beschreibung: Empirical evidence of the relationship between social support and post-disaster mental health provides support for a general beneficial effect of social support (main-effect model; Wheaton, 1985). From a theoretical perspective, a buffering effect of social support on the negative relationship between disaster-related stress and mental health also seems plausible (stress-buffering model; Wheaton, 1985). Previous studies, however, (a) have paid less attention to the buffering effect of social support and (b) have mainly relied on interpersonal support (but not collective-level support such as community resilience) when investigating this issue. This previous work might have underestimated the effect of support on post-disaster mental health. Building on a sample of residents in Germany recently affected by flooding (N=118), we show that community resilience to flooding (but not general interpersonal social support) buffered against the negative effects of flooding on post-disaster mental health. The results support the stress-buffering model and call for a more detailed look at the relationship between support and resilience and post-disaster adjustment, including collective-level variables.

Beschreibung: This paper presents a discrete-element-based elastoplastic-adhesive model which is adapted and tested for producing hillslope debris flows. The numerical model produces three phases of particle contacts: elastic, plastic and adhesive. A parametric study was conducted investigating the effect of model parameters and inclination angle on flow height, velocity and pressure, in order to define the most sensitive parameters to calibrate. The model capabilities of simulating different types of cohesive granular flows were tested with different ranges of flow velocities and heights. The basic model parameters, the microscopic basal friction (ϕb) and ratio between stiffness parameters k1/k2, were calibrated using field experiments of hillslope debris flows impacting a pressure-measuring sensor. Simulations of 50 m3 of material were carried out on a channelized surface that is 41 m long and 8 m wide. The calibration process was based on measurements of flow height, flow velocity and the pressure applied to a sensor. Results of the numerical model matched those of the field data in terms of pressure and flow velocity well while less agreement was observed for flow height. Those discrepancies in results were due in part to the deposition of material in the field test, which is not reproducible in the model. Results of best-fit model parameters against selected experimental tests suggested that a link might exist between the model parameters ϕb and k1/k2 and the initial conditions of the tested granular material (bulk density and water and fine contents). The good performance of the model against the full-scale field experiments encourages further investigation by conducting lab-scale experiments with detailed variation in water and fine content to better understand their link to the model's parameters.

Beschreibung: The characterization of triggering dynamics and remobilized volumes is crucial to the assessment of associated lahar hazards. We propose an innovative treatment of the cascading effect between tephra fallout and lahar hazards based on probabilistic modelling that also accounts for a detailed description of source sediments. As an example, we have estimated the volumes of tephra fallout deposit that could be remobilized by rainfall-triggered lahars in association with two eruptive scenarios that have characterized the activity of the La Fossa cone (Vulcano, Italy) in the last 1000 years: a long-lasting Vulcanian cycle and a subplinian eruption. The spatial distribution and volume of deposits that could potentially trigger lahars were analysed based on a combination of tephra fallout probabilistic modelling (with TEPHRA2), slope-stability modelling (with TRIGRS), field observations, and geotechnical tests. Model input data were obtained from both geotechnical tests and field measurements (e.g. hydraulic conductivity, friction angle, cohesion, total unit weight of the soil, and saturated and residual water content). TRIGRS simulations show how shallow landsliding is an effective process for eroding pyroclastic deposits on Vulcano. Nonetheless, the remobilized volumes and the deposit thickness threshold for lahar initiation strongly depend on slope angle, rainfall intensity, grain size, friction angle, hydraulic conductivity, and the cohesion of the source deposit.

Beschreibung: Community-based disaster preparedness is an important component of disaster management. Knowledge of interventions that communities utilize in response to hazards is important to develop local-level capacity and increase community resilience. This paper systematically examines empirical information about local-level responses to hazards based on peer-reviewed, published case studies. We developed a data set based on 188 articles providing information from 318 communities from all regions of the world. We classified response examples to address four key questions: (i) what kinds of responses are used by communities all over the world? (ii) Do communities in different parts of the world use different kinds of responses? (iii) Are communities using hazard-specific responses? (iv) Are communities using a multi-hazard approach? We found that within an extensive literature on hazards, there is relatively little empirical information about community-based responses to hazards. Across the world, responses aiming at securing basic human needs are the most frequently reported kinds of responses. Although the notion of community-based disaster preparedness is gaining importance, very few examples of responses that draw on the social fabric of communities are reported. Specific regions of the world are lacking in their use of certain hazard responses classes. Although an all-hazard approach for disaster preparedness is increasingly recommended, there is a lack of multi-hazard response approaches on the local level.

Beschreibung: A total of 2.7 billion people live in areas where earthquakes causing at least slight damage have to be expected regularly. Providing information can potentially save lives and improve the resilience of a society. Maps are an established way to illustrate natural hazards. Despite being mainly tailored to the requirements of professional users, they are often the only accessible information to help the public in deciding about mitigation measures. There is evidence that hazard maps are frequently misconceived. Visual and textual characteristics as well as the manner of presentation have been shown to influence their comprehensibility. Using a real case reflecting current practices, the material to communicate the updated seismic hazard model for Switzerland was analyzed in a representative online survey of the population (N=491) and in two workshops involving architects and engineers not specializing in seismic retrofitting (N=23). Although many best-practice recommendations have been followed, the understanding of seismic hazard information remains challenging. Whereas most participants were able to distinguish hazardous from less hazardous areas, correctly interpreting detailed results and identifying the most suitable set of information for answering a given question proved demanding. We suggest scrutinizing current natural-hazard communication strategies, empirically testing new products, and exploring alternatives to raise awareness and enhance preparedness.

Beschreibung: Seismically induced ground motion at a site is generally influenced by the seismic source, the propagation path and the local site conditions. Over the last several decades, researchers have consistently asserted that for near-site attenuation, the spectral parameter κ is subject primarily to the site conditions. In this research, we estimated the parameter κ based on the acceleration amplitude spectrum of shear waves from local earthquakes recorded by seismological stations situated in the western part of Croatia from the slope of the high-frequency part. The spatial distribution of κ values is comparable with seismological, geophysical and geological features, with the published coda-Q values for each station as well as with the isoseismal maps for selected stronger earthquakes in the study area. The complex pattern of longitudinal and transversal major late-orogenic fault zones dissecting early-orogenic thin-skinned tectonic cover in the Kvarner area and the shallow depth to the Moho (Mohorovičić discontinuity) in the Adriatic foreland (southern Istria) are probably responsible for a significant part of wave attenuation and for the anisotropy of attenuation. Regional near-surface attenuation distribution and modelled macroseismic fields point to the conclusion that attenuation properties of rocks in the northwestern External Dinarides are far from isotropic, and the most likely anisotropy sources are the preferential orientations of cracks and fractures under the local tectonic stress field, trapping of waves along major faults (waveguides), and/or attenuation within the fault zones. These results are important for gaining further insight into the attenuation of near-surface crust layers in the northwestern External Dinarides and the associated Adriatic foreland as well as in similar geotectonic settings.

Beschreibung: Flash floods are a recurrent hazard for many developing Latin American regions due to their complex mountainous terrain and the rainfall characteristics in the tropics. These regions often lack the timely and high-quality information needed to assess, in real time, the threats to the vulnerable communities due to extreme hydrometeorological events. The systematic assessment of past extreme events allows us to improve our prediction capabilities of flash floods. In May 2015, a flash flood in the La Liboriana basin, municipality of Salgar, Colombia, caused more than 100 casualties and significant infrastructure damage. Despite the data scarcity, the climatological aspects, meteorological conditions, and first-order hydrometeorological mechanisms associated with the La Liboriana flash flood, including orographic intensification and the spatial distribution of the rainfall intensity relative to the basin's geomorphological features, are studied using precipitation information obtained using a weather radar quantitative precipitation estimation (QPE) technique, as well as from satellite products, in situ rain gauges from neighboring basins, quantitative precipitation forecasts (QPFs) from an operational Weather Research and Forecasting Model (WRF) application, and data from reanalysis products. The La Liboriana flash flood took place during a period with negative precipitation anomalies over most of the country as a result of an El Niño event. However, during May 2015, moist easterly flow towards the upper part of La Liboriana caused significant orographic rainfall enhancement. The overall evidence shows an important role of successive precipitation events in a relatively short period and of orography in the spatial distribution of rainfall and its intensification as convective cores approached the steepest topography. There were three consecutive events generating significant rainfall within the La Liboriana basin, and no single precipitation event was exceptionally large enough to generate the flash flood, but rather the combined role of precedent rainfall and the extreme hourly precipitation triggered the event. The results point to key lessons for improving local risk reduction strategies in vulnerable regions with complex terrain.

Beschreibung: It is necessary to evaluate aggregate damage probability to multiple buildings when performing probabilistic risk assessment for the buildings. The purpose of this study is to demonstrate a method of tsunami hazard and risk assessment for two buildings far away from each other, using copulas of tsunami hazards that consider the nonlinear spatial correlation of tsunami wave heights. First, we simulated the wave heights considering uncertainty by varying the slip amount and fault depths. The frequency distributions of the wave heights were evaluated via the response surface method. Based on the distributions and numerically simulated wave heights, we estimated the optimal copula via maximum likelihood estimation. Subsequently, we evaluated the joint distributions of the wave heights and the aggregate damage probabilities via the marginal distributions and the estimated copulas. As a result, the aggregate damage probability of the 99th percentile value was approximately 1.0 % higher and the maximum value was approximately 3.0 % higher while considering the wave height correlation. We clearly showed the usefulness of copula modeling considering the wave height correlation in evaluating the probabilistic risk of multiple buildings. We only demonstrated the risk evaluation method for two buildings, but the effect of the wave height correlation on the results is expected to increase if more points are targeted.

Beschreibung: We report on the first recorded case of thunderstorm asthma in Israel, which occurred during an exceptionally strong eastern Mediterranean multicell thunderstorm on 25 October 2015. The storms were accompanied by intensive lightning activity, severe hail, downbursts and strong winds followed by intense rain. It was the strongest lightning-producing storm ever recorded by the Israeli Lightning Detection Network (ILDN) since it began operations in 1997. After the passage of the gust front and the ensuing increase in particle concentrations, documented by air-quality sensors, the hospital emergency room (ER) presentation records from three hospitals – two in the direct route of the storm (Meir Medical Center in Kfar Saba and Ha'Emek in Afula) and the other just west of its ground track (Rambam Medical Center in Haifa) – showed that the amount of presentation of patients with respiratory problems in the hours immediately following the storm increased compared with the average numbers in the days before. This pattern is in line with that reported by Thien et al. (2018) for the massive thunderstorm asthma epidemic in Melbourne, Australia. The increase in patient presentations to the emergency rooms persisted for an additional 48–72 h before going back to normal values, indicating that it was likely related to the multi-cell outflow. We discuss how the likelihood of incidence of such public health events associated with thunderstorms will be affected by global trends in lightning occurrence.

Beschreibung: To limit the losses due to floods, public authorities can try to foster the adoption of private measures aimed at reducing the vulnerability of dwellings. However, the efficacy and cost-efficiency of such measures to reduce material losses are not well-known. In particular, the influence of building and flood characteristics on these variables has not been thoroughly studied. A better understanding of this topic would help identify the measures that are relevant to implement in specific contexts. To address this gap, we examined the effect of building and flood characteristics on the cost, efficacy, and cost-efficiency of three groups of measures taken for existing dwellings: one consists of elevating the dwelling, one of dry proofing it, and one of using construction materials that are resistant to water or cheap to repair or replace. We combined expert judgement and computer modelling to assess their cost, efficacy, and cost-efficiency for a wide range of flood depths and durations, building characteristics, and levels of exposure. We found that the value of the building components has a positive effect on the efficacy of dry proofing and elevating a dwelling. Both the efficacy and cost of these two groups of measures increase with the size of the dwelling. Moreover, according to our results, dry proofing and elevating a dwelling are unlikely to be cost-efficient for dwellings that are not exposed to floods with a return period lower than 100 and 30 years, respectively. Our findings also highlight that it is often less expensive to use the adapted than the original materials when rebuilding a damaged dwelling. Moreover, adapting the materials of an intact dwelling is unlikely to be cost-efficient for dwellings that are not exposed to floods with a return period lower than 20 years. Our results apply to France because the damage and the installation costs of the measures are specific to France and the geometry of the dwellings considered to perform our analyses is based on French dwellings.

Beschreibung: Rip currents and other surf hazards are an emerging public health issue globally. Lifeguards, warning flags, and signs are important, and to varying degrees they are effective strategies to minimize risk to beach users. In the United States and other jurisdictions around the world, lifeguards use coloured flags (green, yellow, and red) to indicate whether the danger posed by the surf and rip hazard is low, moderate, or high respectively. The choice of flag depends on the lifeguard(s) monitoring the changing surf conditions along the beach and over the course of the day using both regional surf forecasts and careful observation. There is a potential that the chosen flag is not consistent with the beach user perception of the risk, which may increase the potential for rescues or drownings. In this study, machine learning is used to determine the potential for error in the flags used at Pensacola Beach and the impact of that error on the number of rescues. Results of a decision tree analysis indicate that the colour flag chosen by the lifeguards was different from what the model predicted for 35 % of days between 2004 and 2008 (n=396/1125). Days when there is a difference between the predicted and posted flag colour represent only 17 % of all rescue days, but those days are associated with ∼60 % of all rescues between 2004 and 2008. Further analysis reveals that the largest number of rescue days and total number of rescues are associated with days where the flag deployed over-estimated the surf and hazard risk, such as a red or yellow flag flying when the model predicted a green flag would be more appropriate based on the wind and wave forcing alone. While it is possible that the lifeguards were overly cautious, it is argued that they most likely identified a rip forced by a transverse-bar and rip morphology common at the study site. Regardless, the results suggest that beach users may be discounting lifeguard warnings if the flag colour is not consistent with how they perceive the surf hazard or the regional forecast. Results suggest that machine learning techniques have the potential to support lifeguards and thereby reduce the number of rescues and drownings.

Beschreibung: Coastal-water hypoxia is increasing globally due to global warming and urbanization, and the need to define management solutions to improve the water quality of coastal ecosystems has become important. The lower tidal Garonne River (TGR; southwestern France), characterized by the seasonal presence of a turbidity maximum zone (TMZ) and urban water discharge, is subject to episodic hypoxia events during low river flow periods in the summer. Future climatic conditions (higher temperature and summer droughts) and increasing urbanization could enhance hypoxia risks near the city of Bordeaux in the coming decades. A 3-D model of dissolved oxygen (DO) that couples hydrodynamics, sediment transport and biogeochemical processes was used to assess the efficiency of different management solutions for oxygenation of the TGR during summer low-discharge periods. We ran different scenarios of reductions in urban sewage overflows, displacement of urban discharges downstream from Bordeaux and/or temporary river flow support during the summer period. The model shows that each option mitigates 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 for better oxygenation levels in the lower TGR. The support of low river flow limits the upstream TMZ propagation and dilutes the TGR water with well-oxygenated river water. 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 the TGR.Highlights. A 3-D model shows different efficiencies of management actions to limit hypoxia. Downstream relocation of wastewater discharge totally mitigates hypoxia. Sewage overflow reduction improves DO levels but only locally. Water replenishment improves DO in the upper estuary.

Beschreibung: We developed a new approach for mapping landslide hazards by combining probabilities of landslide impacts derived from a data-driven statistical approach and a physically based model of shallow landsliding. Our statistical approach integrates the influence of seven site attributes (SAs) on observed landslides using a frequency ratio (FR) method. Influential attributes and resulting susceptibility maps depend on the observations of landslides considered: all types of landslides, debris avalanches only, or source areas of debris avalanches. These observational datasets reflect the detection of different landslide processes or components, which relate to different landslide-inducing factors. For each landslide dataset, a stability index (SI) is calculated as a multiplicative result of the frequency ratios for all attributes and is mapped across our study domain in the North Cascades National Park Complex (NOCA), Washington, USA. A continuous function is developed to relate local SI values to landslide probability based on a ratio of landslide and non-landslide grid cells. The empirical model probability derived from the debris avalanche source area dataset is combined probabilistically with a previously developed physically based probabilistic model. A two-dimensional binning method employs empirical and physically based probabilities as indices and calculates a joint probability of landsliding at the intersections of probability bins. A ratio of the joint probability and the physically based model bin probability is used as a weight to adjust the original physically based probability at each grid cell given empirical evidence. The resulting integrated probability of landslide initiation hazard includes mechanisms not captured by the infinite-slope stability model alone. Improvements in distinguishing potentially unstable areas with the proposed integrated model are statistically quantified. We provide multiple landslide hazard maps that land managers can use for planning and decision-making, as well as for educating the public about hazards from landslides in this remote high-relief terrain.

Beschreibung: Despite interventions intended to reduce impacts of coastal hazards, the risk of damage along the US Atlantic coast continues to rise. This reflects a long-standing paradox in disaster science: even as physical and social insights into disaster events improve, the economic costs of disasters keep growing. Risk can be expressed as a function of three components: hazard, exposure, and vulnerability. Risk may be driven up by coastal hazards intensifying with climate change, or by increased exposure of people and infrastructure in hazard zones. But risk may also increase because of interactions, or feedbacks, between hazard, exposure, and vulnerability. Using empirical records of shoreline change, valuation of owner-occupied housing, and beach-nourishment projects to represent hazard, exposure, and vulnerability, here we present a data-driven model that describes trajectories of risk at the county scale along the US Atlantic coast over the past 5 decades. We also investigate quantitative relationships between risk components that help explain these trajectories. We find higher property exposure in counties where hazard from shoreline change has appeared to reverse from high historical rates of shoreline erosion to low rates in recent decades. Moreover, exposure has increased more in counties that have practised beach nourishment intensively. The spatio-temporal relationships that we show between exposure and hazard, and between exposure and vulnerability, indicate a feedback between coastal development and beach nourishment that exemplifies the “safe development paradox”, in which hazard protections encourage further development in places prone to hazard impacts. Our findings suggest that spatially explicit modelling efforts to predict future coastal risk need to address feedbacks between hazard, exposure, and vulnerability to capture emergent patterns of risk in space and time.

Beschreibung: The purpose of this study is to propose the Bayesian network (BN) model to estimate flood peaks from atmospheric ensemble forecasts (AEFs). The Weather Research and Forecasting (WRF) model was used to simulate historic storms using five cumulus parameterization schemes. The BN model was trained to compute flood peak forecasts from AEFs and hydrological pre-conditions. The mean absolute relative error was calculated as 0.076 for validation data. An artificial neural network (ANN) was applied for the same problem but showed inferior performance with a mean absolute relative error of 0.39. It seems that BN is less sensitive to small data sets, thus it is more suited for flood peak forecasting than ANN.

Beschreibung: An extraordinary convective rainfall event, unforeseen by most numerical weather prediction models, generated a devastating flash flood (305 m3 s−1) in the town of Sant Llorenç des Cardassar, Mallorca, on 9 October 2018. Four people died inside this village, while casualties were up to 13 over the entire affected area. This extreme event has been reconstructed by implementing an integrated flash flood modelling approach in the Ses Planes catchment up to Sant Llorenç (23.4 km2), based on three components: (i) generation of radar-derived precipitation estimates, (ii) modelling of accurate discharge hydrographs yielded by the catchment (using FEST and KLEM models), and (iii) hydraulic simulation of the event and mapping of affected areas (using HEC-RAS). Radar-derived rainfall estimates show very high agreement with rain gauge data (R2=0.98). Modelled flooding extent is in close agreement with the observed extension by the Copernicus Emergency Management Service, based on Sentinel-1 imagery, and both far exceed the extension for a 500-year return period flood. Hydraulic simulation revealed that water reached a depth of 3 m at some points, and modelled water depths highly correlate (R2=0.91) with in situ after-event measurements. The 9 October flash flood eroded and transported woody and abundant sediment debris, changing channel geomorphology. Water velocity greatly increased at bridge locations crossing the river channel, especially at those closer to the Sant Llorenç town centre. This study highlights how the very low predictability of this type of extreme convective rainfall events and the very short hydrological response times typical of small Mediterranean catchments continue to challenge the implementation of early warning systems, which effectively reduce people's exposure to flash flood risk in the region.

Beschreibung: This paper presents AGRIDE-c, a conceptual model for the assessment of flood damage to crops, in favour of more comprehensive flood damage assessments. Available knowledge on damage mechanisms triggered by inundation phenomena is systematised in a usable and consistent tool, with the main strength represented by the integration of physical damage assessment into the evaluation of its economic consequences on the income of the farmers. This allows AGRIDE-c to be used to guide the flood damage assessment process in different geographical and economic contexts, as demonstrated by the example provided in this study for the Po Plain (north of Italy). The development and implementation of the model highlighted that a thorough understanding and modelling of mechanisms causing damage to crops is a powerful tool to support more effective damage mitigation strategies, both at public and at private (i.e. farmers) levels.

Beschreibung: An early warning system for flood prediction based on precipitation forecast is presented. The system uses rainfall forecast provided by MeteoGalicia in combination with a hydrologic (Hydrologic Modeling System, HEC-HMS) and a hydraulic (Iber+) model. The upper reach of the Miño River and the city of Lugo (NW Spain) are used as a study area. Starting from rainfall forecast, HEC-HMS calculates the streamflow and Iber+ is automatically executed for some previously defined risk areas when a certain threshold is exceeded. The analysis based on historical extreme events shows that the system can provide accurate results in less than 1 h for a forecast horizon of 3 d and report an alert situation to decision makers.

Beschreibung: Snow gliding and glide-snow avalanches are gaining importance among scientists as global warming might induce conditions favourable to those phenomena. Our aim is to analyse such processes with a particular focus on the potential driving factors associated with the soil conditions. We equipped two experimental test sites in the Aosta Valley region (NW Italy) with glide-snow shoes, temperature and volumetric liquid water content (VLWC) sensors in the soil and in the basal snowpack layer; snow and weather parameters were also collected by automatic weather stations and at manual snow measuring sites. In the two monitoring seasons 2013–2014 and 2014–2015 we registered nine glide-snow avalanches, two cold and seven warm events, which were characterized by different snow and soil conditions. In the only warm glide-snow avalanche event, which presented a continuous gliding before, the daily glide rate showed a significant exponential relationship with the soil VLWC. We also found, though without a general trend, that gliding and non-gliding periods (either considering warm and cold periods separately or together) were characterized by significantly different predisposing factors. This study contributes to the assessment of the importance of soil VLWC, which seems to be one of the most important driving factors for gliding processes. Therefore, it supports the need, already suggested by other scientists, for analysing such processes with an interdisciplinary approach which integrates snow and soil sciences.

Beschreibung: A hypothetical Pan-European Indoor Radon Map has been developed using summary statistics estimated from 1.2 million indoor radon samples. In this study we have used the arithmetic mean (AM) over grid cells of 10 km × 10 km to predict a mean indoor radon concentration at ground-floor level of buildings in the grid cells where no or few data (N

Beschreibung: Peak ground acceleration (PGA) and study area (SA) distribution for the Patna district are presented considering both the classical and zoneless approaches through a logic tree framework to capture the epistemic uncertainty. Seismicity parameters are calculated by considering completed and mixed earthquake data. Maximum magnitude is calculated using three methods, namely the incremental method, Kijko method, and regional rupture characteristics approach. The best suitable ground motion prediction equations (GMPEs) are selected by carrying out an “efficacy test” using log likelihood. Uniform hazard response spectra have been compared with Indian standard BIS 1893. PGA varies from 0.38 to 0.30 g from the southern to northern periphery considering 2 % probability of exceedance in 50 years.