Natural Hazards and Earth System Sciences

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Combined list of the recent articles of the journal Natural Hazards and Earth System Sciences and the recent discussion forum Natural Hazards and Earth System Sciences Discussions
Updated: 2 weeks 3 days ago

What's streamflow got to do with it? A probabilistic simulation of the competing oceanographic and fluvial processes driving extreme along-river water levels

Tue, 07/16/2019 - 17:41
What's streamflow got to do with it? A probabilistic simulation of the competing oceanographic and fluvial processes driving extreme along-river water levels
Katherine A. Serafin, Peter Ruggiero, Kai Parker, and David F. Hill
Nat. Hazards Earth Syst. Sci., 19, 1415-1431, https://doi.org/10.5194/nhess-19-1415-2019, 2019
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.

Improving sub-seasonal forecast skill of meteorological drought: a weather pattern approach

Tue, 07/16/2019 - 17:41
Improving sub-seasonal forecast skill of meteorological drought: a weather pattern approach
Doug Richardson, Hayley J. Fowler, Chris G. Kilsby, Robert Neal, and Rutger Dankers
Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2019-221,2019
Manuscript under review for NHESS (discussion: open, 0 comments)
Models are not particularly skilful at forecasting rainfall more than 15 days in advance. However, they are often better at predicting atmospheric variables such as mean sea level pressure (MSLP). Comparing a range of models, we show that UK winter and autumn rainfall and drought prediction skill can be improved by utilising forecasts of MSLP-based weather patterns (WPs) and subsequently estimating rainfall using the historical WP-precipitation relationships.

Towards early warning of gravitational slope failure with co-detection of microseismic activity: the case of an active rock glacier

Mon, 07/15/2019 - 17:41
Towards early warning of gravitational slope failure with co-detection of microseismic activity: the case of an active rock glacier
Jérome Faillettaz, Martin Funk, Jan Beutel, and Andreas Vieli
Nat. Hazards Earth Syst. Sci., 19, 1399-1413, https://doi.org/10.5194/nhess-19-1399-2019, 2019
We developed a new strategy for real-time early warning of gravity-driven slope failures (such as landslides, rockfalls, glacier break-off, etc.). This method enables us to investigate natural slope stability based on continuous monitoring and interpretation of seismic waves generated by the potential instability. Thanks to a pilot experiment, we detected typical patterns of precursory events prior to slide events, demonstrating the potential of this method for real-word applications.

High-frequency glacial lake mapping using time series of Sentinel-1A/1B SAR imagery: An assessment for southeastern Tibetan Plateau

Mon, 07/15/2019 - 17:41
High-frequency glacial lake mapping using time series of Sentinel-1A/1B SAR imagery: An assessment for southeastern Tibetan Plateau
Meimei Zhang, Fang Chen, Bangsen Tian, Dong Liang, and Aqiang Yang
Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2019-219,2019
Manuscript under review for NHESS (discussion: open, 1 comment)

Glacial lakes are important component of the cryosphere in the Tibetan Plateau. In response to climate warming, they threaten the downstream lives, ecological environment and public infrastructures through outburst floods in a short time. Although most of the efforts have been made to extract glacial lake outlines and detect their changes with remotely sensed images, the temporal frequency and spatial resolution of glacial lake datasets are generally not fine enough to reflect the detailed process of glacial lake dynamics, especially for potentially dangerous glacial lakes with high-frequency variability. By using a full time-series Sentinel-1A/1B imagery during a year, this study presents a new systematic method to extract the glacial lake outlines with fast variability in southeastern Tibetan Plateau at the time interval of six days. Our approach was based on the level-set segmentation, combined with a median pixel compositing of SAR backscattering coefficients stacks as regularization term, to robustly estimate the lake extent across the observed time range. The mapping results were validated against with manually digitized lake outlines derived from GF-2 PMS imagery, with the overall accuracy and Kappa coefficient of 96.54 % and 0.95, respectively. In comparison with results from classical supervised SVM and unsupervised ISODATA methods, the proposed method proves to be much more robust and effective to detect glacial lakes with irregular boundaries and that have similar backscattering with surroundings. This study also demonstrates the feasibility of time-series Sentinel-1A/1B SAR data in continuous monitoring of glacial lake outline dynamics.

Hydro-meteorological reconstruction and geomorphological impact assessment of the October, 2018 catastrophic flash flood at Sant Llorenç, Mallorca (Spain)

Thu, 07/11/2019 - 18:45
Hydro-meteorological reconstruction and geomorphological impact assessment of the October, 2018 catastrophic flash flood at Sant Llorenç, Mallorca (Spain)
Jorge Lorenzo-Lacruz, Celso Garcia, Enrique Morán-Tejeda, Arnau Amengual, Víctor Homar, Aina Maimó-Far, Alejandro Hermoso, Climent Ramis, and Romualdo Romero
Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2019-226,2019
Manuscript under review for NHESS (discussion: open, 0 comments)
On October 9, 2018, an extreme convective storm (> 300 mm accumulated in 6 h.) generated a flash flood (307 m3/s) in the Ses Planes torrent that devastated the town of Sant Llorenç (Mallorca, Spain). Water reached a depth of 3 m in the most affected areas, and there was greatly increased flow velocity at bridges crossing the town. The floodwaters were very powerful and modified the channel morphology: more than 5000 metric tonnes of sediment were deposited in the 2 km reach upstream of the town.

From rapid visual survey to multi-hazard risk prioritisation and numerical fragility of school buildings

Thu, 07/11/2019 - 17:41
From rapid visual survey to multi-hazard risk prioritisation and numerical fragility of school buildings
Roberto Gentile, Carmine Galasso, Yunita Idris, Ibnu Rusydy, and Ella Meilianda
Nat. Hazards Earth Syst. Sci., 19, 1365-1386, https://doi.org/10.5194/nhess-19-1365-2019, 2019
This paper introduces the INSPIRE index, which quantifies the relative seismic risk of reinforced concrete buildings. A rapid visual survey form is proposed, which allows us to (1) calculate the INSPIRE index, (2) calculate a tsunami risk index, and (3) define archetype buildings to be analysed in more detail. The effectiveness of such tools is demonstrated with an application to 85 school buildings in Indonesia, also providing detailed numerical simulations for an archetype building.

Simultaneous state–parameter estimation of rainfall-induced landslide displacement using data assimilation

Thu, 07/11/2019 - 16:59
Simultaneous state–parameter estimation of rainfall-induced landslide displacement using data assimilation
Jing Wang, Guigen Nie, Shengjun Gao, and Changhu Xue
Nat. Hazards Earth Syst. Sci., 19, 1387-1398, https://doi.org/10.5194/nhess-19-1387-2019, 2019
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.

Evaluation of a model for mapping intense pluvial runoff hazard using proxy data of runoff-related impacts. Application to the railway context

Wed, 07/10/2019 - 19:01
Evaluation of a model for mapping intense pluvial runoff hazard using proxy data of runoff-related impacts. Application to the railway context
Isabelle Braud, Lilly-Rose Lagadec, Loïc Moulin, Blandine Chazelle, and Pascal Breil
Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2019-208,2019
Manuscript under review for NHESS (discussion: open, 0 comments)
A method for the evaluation of a model that maps the susceptibility of a territory to surface runoff is presented. It is based on proxy data of localized impacts related to runoff. It accounts for the hazard level, the vulnerability of the study area and possible mitigation actions taken to reduce the risk. The evaluation is made on a 80 km railway line in Normandy (North of France), where a comprehensive database of runoff-related impacts on the railway has been gathered over the 20th century.

Hydrometeorological Conditions Leading to the 2015 Salgar Flash Flood: Lessons for Vulnerable Regions in Tropical Complex Terrain

Wed, 07/10/2019 - 17:46
Hydrometeorological Conditions Leading to the 2015 Salgar Flash Flood: Lessons for Vulnerable Regions in Tropical Complex Terrain
Carlos D. Hoyos, Lina I. Ceballos, Jhayron S. Pérez, Julián Sepúlveda, Silvana M. López, Manuel D. Zuluaga, Nicolás Velásquez, Laura Herrera, Olver Hernández, Gisel Guzmán, and Mauricio Zapata
Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2019-171,2019
Manuscript under review for NHESS (discussion: open, 0 comments)
On the morning of May 18, 2015, a flash flood in La Liboriana river basin inundated the town of Salgar, killing more than one hundred people. The ultimate goal of science, regarding risk management, is to be able to reduce the number of people affected by severe storms. Our goal is to identify the meteorological conditions that led to the flood, assessing the characteristics of the rainfall events before the disaster, and identifying lessons for vulnerable regions settled in complex terrain.

Spatial Seismic Hazard Variation and Adaptive Sampling of Portfolio Location Uncertainty in Probabilistic Seismic Risk Analysis

Wed, 07/10/2019 - 17:46
Spatial Seismic Hazard Variation and Adaptive Sampling of Portfolio Location Uncertainty in Probabilistic Seismic Risk Analysis
Christoph Scheingraber and Martin Käser
Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2019-110,2019
Manuscript under review for NHESS (discussion: open, 0 comments)
Probabilistic Seismic Risk Analysis is widely used in the insurance industry to model losses to insured portfolios by earthquake events. Risk items are often only known to be located within an administrative geographical zone, but precise coordinates remain unknown to the modeler. We analyze spatial seismic hazard and loss rate variation inside administrative zones in western Indonesia. Building upon this, we present a novel framework for efficient treatment of portfolio location uncertainty.

Integrated sea storm management strategy: the 29 October 2018 event in the Adriatic Sea

Tue, 07/09/2019 - 19:01
Integrated sea storm management strategy: the 29 October 2018 event in the Adriatic Sea
Christian Ferrarin, Andrea Valentini, Martin Vodopivec, Dijana Klaric, Giovanni Massaro, Marco Bajo, Francesca De Pascalis, Amedeo Fadini, Michol Ghezzo, Stefano Menegon, Lidia Bressan, Silvia Unguendoli, Anja Fettich, Jure Jerman, Matjaž Licer, Lidija Fustar, Alvise Papa, and Enrico Carraro
Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2019-212,2019
Manuscript under review for NHESS (discussion: open, 0 comments)

Addressing coastal risks related to sea storms requires an integrative approach which combines monitoring stations, forecasting models, early warning systems and coastal management and planning. Such great effort is sometimes possible only through transnational cooperation, which becomes thus vital to face effectively and promptly these marine events which are responsible for several damages impacting on the environment and citizens' life. Here we present a shared and interoperable system to allow a better exchange and elaboration of information related to sea storms among countries. The proposed Integrated Web System (IWS) is a combination of a common data system for sharing ocean observations and forecasts, a multi-model ensemble system, a geoportal and interactive geo-visualization tools to make results available to the general public. Multi-model ensemble mean and spread for sea level height and wave characteristics are used to describe three different sea condition scenarios. IWS is designed to provide sea state information required for issuing coastal risk alerts over the analysed region, as well as for being easily integrated into existing local early warning systems. This study describes the application of the developed system to the exceptional storm event of 29th of October 2018, that caused severe flooding and damages to coastal infrastructures in the Adriatic Sea. The forecasted ensemble products were successfully compared with in situ observations. The hazards estimated by integrating IWS results into existing early warning systems were confirmed by documented storm impacts along the coast of Slovenia, Emilia-Romagna and the City of Venice. For the investigated event, the most severe simulated scenario resulted to provide a realistic and conservative estimation of the peak storm conditions to be used in coastal risk management.

Analysis of Employment Change in Response to Hurricane Landfalls

Tue, 07/09/2019 - 19:01
Analysis of Employment Change in Response to Hurricane Landfalls
Yuepeng Cui, Daan Liang, and Bradley Ewing
Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2019-201,2019
Manuscript under review for NHESS (discussion: open, 1 comment)
The methodology presented in this paper is considered as an important entry point to addressing the complex problems related to disaster resilience. Regardless of storms, hurricane impact on local employment is found to be either temporary or permanent in nature.Relating the concept of resilience to observable socioeconomic activities helps us gaining a deeper understanding of the drivers and the processes of of post-storm recovery. Studies play a major role in bridging the knowledge gaps.

Case Study: Risk Analysis by Overtopping During an Upstream Landslide in Peñitas Dam, Mexico

Tue, 07/09/2019 - 19:01
Case Study: Risk Analysis by Overtopping During an Upstream Landslide in Peñitas Dam, Mexico
Humberto J. F. Marengo and Alvaro A. Aldama
Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2019-191,2019
Manuscript under review for NHESS (discussion: open, 0 comments)
In this paper is made a risk analysis by overtopping of existing Peñitas dam that could be caused by a flood produced by the failure of an upstream natural dam product of a landslide: is showed a real case and its solution; innovative mathematical approach analysis is presented. Risk model analysis developed is applicable to similar cases could happen in any site of the world. Uncertainty analysis of variables that have their own hypotheses, limitations, advantages and disadvantages is made.

Exposure of properties to the 2018 Hurricane Florence flooding: an expanding bull's-eye perspective

Mon, 07/08/2019 - 17:50
Exposure of properties to the 2018 Hurricane Florence flooding: an expanding bull's-eye perspective
Marco Tedesco, Steven McAlpine, and Jeremy Porter
Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2019-209,2019
Manuscript under review for NHESS (discussion: open, 0 comments)
Quantifying the exposure of house property to extreme weather events is crucial to study their impact on our economy. Here, we show that property value exposed to Hurricane Florence in September 2018 was 52$B vs. 10$B that would have occurred at the beginning of the 19th century. This is due to the urban expansion that increased after 1950s and to the increasing number of houses built nearby water, showing the importance of accounting for the distribution of new buildings on risk and exposure.

Tectonic Origin Tsunami Scenario Database for the Marmara Region

Mon, 07/08/2019 - 17:50
Tectonic Origin Tsunami Scenario Database for the Marmara Region
Ceren Ozer Sozdinler, Ocal Necmioglu, H. Basak Bayraktar, and Nurcan M. Ozel
Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2019-186,2019
Manuscript under review for NHESS (discussion: open, 0 comments)
We are presenting the first tsunami scenario database in the sea of Marmara, Turkey with comprehensive compilation of historical and empirical seismic data and numerical modeilng using NAMIDANCE in the frame of FP-7 MARSite project. Our main aim is to correlate with the operations of Tsunami Service Provider in KOERI. The results show that hazardous historical tsunamis in Marmara Sea cannot be explained by only earthquakes and submarine landslides should be considered as the primary component.

Back-calculation of the 2017 Piz Cengalo-Bondo landslide cascade with r.avaflow

Mon, 07/08/2019 - 17:50
Back-calculation of the 2017 Piz Cengalo-Bondo landslide cascade with r.avaflow
Martin Mergili, Michel Jaboyedoff, José Pullarello, and Shiva P. Pudasaini
Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2019-204,2019
Manuscript under review for NHESS (discussion: open, 0 comments)

In the morning of 23 August 2017, around 3 million m3 of granitoid rock broke off from the east face of Piz Cengalo, SE Switzerland. The initial rock slide-rock fall entrained 0.6 million m3 of a glacier and continued as a rock(-ice) avalanche, before evolving into a channelized debris flow that reached the village of Bondo at a distance of 6.5 km after a couple of minutes. Subsequent debris flow surges followed in the next hours and days. The event resulted in eight fatalities along its path and severely damaged Bondo. The most likely candidates for the water causing the transformation of the rock avalanche into a long-runout debris flow are the entrained glacier ice and water originating from the debris beneath the rock avalanche. In the present work we try to reconstruct conceptually and numerically the cascade from the initial rock slide-rock fall to the first debris flow surge and thereby consider two scenarios in terms of qualitative conceptual process models: (i) entrainment of most of the glacier ice by the frontal part of the initial rock slide-rock fall and/or injection of water from the basal sediments due to sudden rise in pore pressure, leading to a frontal debris flow, with the rear part largely remaining dry and depositing mid-valley; and (ii) most of the entrained glacier ice remaining beneath/behind the frontal rock avalanche, and developing into an avalanching flow of ice and water, part of which overtops and partially entrains the rock avalanche deposit, resulting in a debris flow. Both scenarios can be numerically reproduced with the two-phase mass flow model implemented with the simulation software r.avaflow, based on plausible assumptions of the model parameters. However, these simulation results do not allow to conclude on which of the two scenarios is the more likely one. Future work will be directed towards the application of a three-phase flow model (rock, ice, fluid) including phase transitions, in order to better represent the melting of glacier ice, and a more appropriate consideration of deposition of debris flow material along the channel.

Statistical theory of probabilistic hazard maps: a probability distribution for the hazard boundary location

Mon, 07/08/2019 - 17:32
Statistical theory of probabilistic hazard maps: a probability distribution for the hazard boundary location
David M. Hyman, Andrea Bevilacqua, and Marcus I. Bursik
Nat. Hazards Earth Syst. Sci., 19, 1347-1363, https://doi.org/10.5194/nhess-19-1347-2019, 2019
In this work, we present new methods for calculating the mean, standard deviation, median, and modal locations of the boundaries of volcanic hazards. These calculations are based on a new, mathematically rigorous definition of probabilistic hazard maps – a way to map the probabilities of inundation by a given hazard. We apply this analysis to several models of volcanic flows: simple models of viscous flows, complex models of a tabletop granular flow, and a complex model of a volcanic mud flow.

Extremeness of recent drought events in Switzerland: dependence on variable and return period choice

Mon, 07/08/2019 - 17:32
Extremeness of recent drought events in Switzerland: dependence on variable and return period choice
Manuela I. Brunner, Katharina Liechti, and Massimiliano Zappa
Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2019-216,2019
Manuscript under review for NHESS (discussion: open, 0 comments)
The 2018 drought event had severe ecological, economic, and social impacts. How extreme was it in Switzerland? We addressed this question by looking at different types of drought, including meteorological, hydrological, agricultural, and groundwater drought, and at the two characteristics deficit and deficit duration. The return period estimates depended on the region, variable, and return period considered.

Contribution of the Sensitivity Analysis in Groundwater Vulnerability Assessing Using the DRASTIC and Composite DRASTIC Indexes

Mon, 07/08/2019 - 17:32
Contribution of the Sensitivity Analysis in Groundwater Vulnerability Assessing Using the DRASTIC and Composite DRASTIC Indexes
Mohammad Malakootian and Majid Nozari
Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2019-181,2019
Manuscript under review for NHESS (discussion: open, 0 comments)
The present study estimates aquifer vulnerability by applying the DRASTIC and composite DRASTIC indexes. The factors affecting the transfer of contamination were ranked, weighted, and integrated using a geographical information system (GIS). Agricultural and industrial activities are found to be a major threat in the zones with high and very high vulnerability. This study results could be utilized by private and government agencies as a guide for groundwater contamination assessment.

Spatiotemporal analysis of flash flooding events in mountainous area of China during 1950–2015

Mon, 07/08/2019 - 17:32
Spatiotemporal analysis of flash flooding events in mountainous area of China during 1950–2015
Nan Wang, Weiming Cheng, Min Zhao, Qiangyi Liu, Jing Wang, and Dongcheng Liu
Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2019-150,2019
Manuscript under review for NHESS (discussion: open, 0 comments)
Flash flooding is one of the most destructive natural disasters that occur in mountainous areas. Understanding the spatiotemporal characteristics of flash flooding across China is important for enabling better disaster estimation and prevention on the national scale. To bridge the gap in the research of the spatiotemporal characteristics of flash flooding events (FFEs), this paper detected the temporal variation, temporal periodic and temporal clustering of FFEs in China.

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