Articles | Volume 20, issue 12
Research article 08 Dec 2020
Research article | 08 Dec 2020
What controls the coarse sediment yield to a Mediterranean delta? The case of the Llobregat River (NE Iberian Peninsula)
Juan P. Martín-Vide et al.
No articles found.
Chenge An, Marwan A. Hassan, Carles Ferrer-Boix, and Xudong Fu
Earth Surf. Dynam., 9, 333–350,Short summary
Mountain rivers are characterized by fluctuations of water flow, including both flood and inter-flood low flow. Recently, increasing attention has been paid to how inter-flood low flow affects the sediment transport in subsequent floods. Here we present a series of flume experiments. Results show that the existence of inter-flood low flow can reduce the sediment transport at the beginning of the subsequent flood. However, such an effect is gradually erased with the increase of flow intensity.
Related subject area
Hydrological HazardsThe uncertainty of flood frequency analyses in hydrodynamic model simulationsFlood risk assessment of the European road networkThe impact of hydrological model structure on the simulation of extreme runoff eventsHydrometeorological analysis and forecasting of a 3 d flash-flood-triggering desert rainstormLand subsidence due to groundwater pumping: hazard probability assessment through the combination of Bayesian model and fuzzy set theoryQuantification of continuous flood hazard using random forest classification and flood insurance claims at large spatial scales: a pilot study in southeast TexasAssessing Chinese flood protection and its social divergenceTyphoon rainstorm simulations with radar data assimilation on the southeast coast of ChinaSimulating historical flood events at the continental scale: observational validation of a large-scale hydrodynamic modelA dynamic bidirectional coupled surface flow model for flood inundation simulationA revision of the Combined Drought Indicator (CDI) used in the European Drought Observatory (EDO)Drought propagation and its impact on groundwater hydrology of wetlands: a case study on the Doode Bemde nature reserve (Belgium)Modelling the Brumadinho tailings dam failure, the subsequent loss of life and how it could have been reducedAssessment of probability distributions and analysis of the minimum storage draft rate in the equatorial regionDownsizing parameter ensembles for simulations of rare floodsDynamic maps of human exposure to floods based on mobile phone dataOpen check dams and large wood: head losses and release conditionsForecasting flood hazards in real time: a surrogate model for hydrometeorological events in an Andean watershedComparison of estimates of global flood models for flood hazard and exposed gross domestic product: a China case studyEvaluation of EURO-CORDEX (Coordinated Regional Climate Downscaling Experiment for the Euro-Mediterranean area) historical simulations by high-quality observational datasets in southern Italy: insights on drought assessmentA multidisciplinary drought catalogue for southwestern Germany dating back to 1801Simulation of extreme rainfall and streamflow events in small Mediterranean watersheds with a one-way-coupled atmospheric–hydrologic modelling systemAssessing Climate Change-Induced Flood Risk in the Conasauga River Watershed: An Application of Ensemble Hydrodynamic Inundation ModelingAnnual flood damage influenced by El Niño in the Kan River basin, IranMultivariate statistical modelling of the drivers of compound flood events in south FloridaBuilding hazard maps with differentiated risk perception for flood impact assessmentChallenges in flood modeling over data-scarce regions: how to exploit globally available soil moisture products to estimate antecedent soil wetness conditions in MoroccoA risk-based network analysis of distributed in-stream leaky barriers for flood risk managementTesting the impact of direct and indirect flood warnings on population behaviour using an agent-based modelSoil moisture and streamflow deficit anomaly index: An approach to quantify drought hazards by combining deficit and anomalyHydrogeomorphological analysis and modelling for a comprehensive understanding of flash-flood damage processes: the 9 October 2018 event in northeastern MallorcaHydrological impacts of climate change on small ungauged catchments – results from a global climate model–regional climate model–hydrologic model chainEvaluating the efficacy of bivariate extreme modelling approaches for multi-hazard scenariosIntegrated evaluation of water-related disasters using the analytical hierarchy process under land use change and climate change issues in LaosEvent generation for probabilistic flood risk modelling: multi-site peak flow dependence model vs. weather-generator-based approachBrief communication: Seasonal prediction of salinity intrusion in the Mekong DeltaSkill of large-scale seasonal drought impact forecastsBrief communication: Comparing hydrological and hydrogeomorphic paradigms for global flood hazard mappingImproving early warning of drought-driven food insecurity in southern Africa using operational hydrological monitoring and forecasting productsInvited perspectives: How machine learning will change flood risk and impact assessmentThe role of spatial dependence for large-scale flood risk estimationA method to use proxy data of runoff-related impacts for the evaluation of a model mapping intense storm runoff hazard: application to the railway contextPredictive skill for atmospheric rivers in the western Iberian PeninsulaEstimation of evapotranspiration by the Food and Agricultural Organization of the United Nations (FAO) Penman–Monteith temperature (PMT) and Hargreaves–Samani (HS) models under temporal and spatial criteria – a case study in Duero basin (Spain)Ensemble flood simulation for a small dam catchment in Japan using nonhydrostatic model rainfalls – Part 2: Flood forecasting using 1600-member 4D-EnVar-predicted rainfallsImproved accuracy and efficiency of flood inundation mapping of low-, medium-, and high-flow events using the AutoRoute modelMeasuring compound flood potential from river discharge and storm surge extremes at the global scaleA joint probabilistic index for objective drought identification: the case study of HaitiEvaluation of two hydrometeorological ensemble strategies for flash-flood forecasting over a catchment of the eastern PyreneesModeling the effects of sediment concentration on the propagation of flash floods in an Andean watershed
Xudong Zhou, Wenchao Ma, Wataru Echizenya, and Dai Yamazaki
Nat. Hazards Earth Syst. Sci., 21, 1071–1085,Short summary
This article assesses different uncertainties in the analysis of flood risk and found the runoff generated before the river routing is the primary uncertainty source. This calls for attention to be focused on selecting an appropriate runoff for the flood analysis. The uncertainties are reflected in the flood water depth, inundation area and the exposure of the population and economy to the floods.
Kees C. H. van Ginkel, Francesco Dottori, Lorenzo Alfieri, Luc Feyen, and Elco E. Koks
Nat. Hazards Earth Syst. Sci., 21, 1011–1027,Short summary
This study presents a state-of-the-art approach to assess flood damage for each unique road segment in Europe. We find a mean total flood risk of EUR 230 million per year for all individual road segments combined. We identify flood hotspots in the Alps, along the Sava River, and on the Scandinavian Peninsula. To achieve this, we propose a new set of damage curves for roads and challenge the community to validate and improve these. Analysis of network effects can be easily added to our analysis.
Gijs van Kempen, Karin van der Wiel, and Lieke Anna Melsen
Nat. Hazards Earth Syst. Sci., 21, 961–976,Short summary
In this study, we combine climate model results with a hydrological model to investigate uncertainties in flood and drought risk. With the climate model, 2000 years of
current climatewas created. The hydrological model consisted of several building blocks that we could adapt. In this way, we could investigate the effect of these hydrological building blocks on high- and low-flow risk in four different climate zones with return periods of up to 500 years.
Yair Rinat, Francesco Marra, Moshe Armon, Asher Metzger, Yoav Levi, Pavel Khain, Elyakom Vadislavsky, Marcelo Rosensaft, and Efrat Morin
Nat. Hazards Earth Syst. Sci., 21, 917–939,Short summary
Flash floods are among the most devastating and lethal natural hazards worldwide. The study of such events is important as flash floods are poorly understood and documented processes, especially in deserts. A small portion of the studied basin (1 %–20 %) experienced extreme rainfall intensities resulting in local flash floods of high magnitudes. Flash floods started and reached their peak within tens of minutes. Forecasts poorly predicted the flash floods mostly due to location inaccuracy.
Huijun Li, Lin Zhu, Gaoxuan Guo, Yan Zhang, Zhenxue Dai, Xiaojuan Li, Linzhen Chang, and Pietro Teatini
Nat. Hazards Earth Syst. Sci., 21, 823–835,Short summary
We propose a method that integrates fuzzy set theory and a weighted Bayesian model to evaluate the hazard probability of land subsidence based on Interferometric Synthetic Aperture Radar technology. The proposed model can represent the uncertainty and ambiguity in the evaluation process, and results can be compared to traditional qualitative methods.
William Mobley, Antonia Sebastian, Russell Blessing, Wesley E. Highfield, Laura Stearns, and Samuel D. Brody
Nat. Hazards Earth Syst. Sci., 21, 807–822,Short summary
In southeast Texas, flood impacts are exacerbated by increases in impervious surfaces, human inaction, outdated FEMA-defined floodplains and modeling assumptions, and changing environmental conditions. The current flood maps are inadequate indicators of flood risk, especially in urban areas. This study proposes a novel method to model flood hazard and impact in urban areas. Specifically, we used novel flood risk modeling techniques to produce annualized flood hazard maps.
Dan Wang, Paolo Scussolini, and Shiqiang Du
Nat. Hazards Earth Syst. Sci., 21, 743–755,Short summary
Flood protection level (FPL) is vital for risk analysis and management but scarce in realty particularly for developing countries. This paper develops a policy-based FPL dataset for China and validates it using local FPL designs. The FPLs are much higher than that in a global database, suggesting Chinese flood risk could be lower with the policy-required FPLs. Moreover, the FPLs are lower for western China and vulnerable people, implying a spatial and social divergence of the FPLs.
Jiyang Tian, Ronghua Liu, Liuqian Ding, Liang Guo, and Bingyu Zhang
Nat. Hazards Earth Syst. Sci., 21, 723–742,Short summary
A typhoon always comes with heavy rainfall which leads to great loss. The aim of this study is to explore the reasonable use of Doppler radar data assimilation to correct the initial and lateral boundary conditions of the numerical weather prediction (NWP) systems for typhoon rainstorm forecasts at catchment scale. The results show that assimilating radial velocity at a time interval of 1 h can significantly improve the rainfall simulations and outperform the other assimilation modes.
Oliver E. J. Wing, Andrew M. Smith, Michael L. Marston, Jeremy R. Porter, Mike F. Amodeo, Christopher C. Sampson, and Paul D. Bates
Nat. Hazards Earth Syst. Sci., 21, 559–575,Short summary
Global flood models are difficult to validate. They generally output theoretical flood events of a given probability rather than an observed event that they can be tested against. Here, we adapt a US-wide flood model to enable the rapid simulation of historical flood events in order to more robustly understand model biases. For 35 flood events, we highlight the challenges of model validation amidst observational data errors yet evidence the increasing skill of large-scale models.
Chunbo Jiang, Qi Zhou, Wangyang Yu, Chen Yang, and Binliang Lin
Nat. Hazards Earth Syst. Sci., 21, 497–515,Short summary
We proposed a new dynamic coupling model for flood simulation and prediction. The model can dynamically alter the coupling boundary position based on the characteristic theory to determine the non-inundation and inundation regions, taking into account both mass and momentum exchange. Then the model was validated by several classic numerical test cases as well as experiment data and implemented in a real study case. Results show its capability for flood simulation and risk assessments.
Carmelo Cammalleri, Carolina Arias-Muñoz, Paulo Barbosa, Alfred de Jager, Diego Magni, Dario Masante, Marco Mazzeschi, Niall McCormick, Gustavo Naumann, Jonathan Spinoni, and Jürgen Vogt
Nat. Hazards Earth Syst. Sci., 21, 481–495,Short summary
Building on almost ten years of expertise and operational application of the Combined Drought Indicator (CDI) for the monitoring of agricultural droughts in Europe within the European Commission's European Drought Observatory (EDO), this paper proposes a revised version of the index. This paper shows that the proposed revised CDI reliably reproduces the evolution of major droughts, outperforming the current version of the indicator, especially for long-lasting events.
Buruk Kitachew Wossenyeleh, Kaleb Asnake Worku, Boud Verbeiren, and Marijke Huysmans
Nat. Hazards Earth Syst. Sci., 21, 39–51,Short summary
Droughts are mainly caused by a reduction of precipitation, and they affect both surface and groundwater resources. Drought propagates through the hydrological cycle and may impact vulnerable ecosystems. We investigated drought propagation in the hydrological cycle, focusing on assessing its impact on a groundwater-fed wetland ecosystem in the Doode Bemde wetland in central Belgium. We used a method combining meteorological drought indices, water balance models and groundwater models.
Darren Lumbroso, Mark Davison, Richard Body, and Gregor Petkovšek
Nat. Hazards Earth Syst. Sci., 21, 21–37,Short summary
A tailings dam is an earth embankment used to store the waste from mines, known as tailings. In 2019, the Brumadinho tailings dam in Brazil failed, releasing a mudflow which killed ~ 300 people. This paper details the use of an agent-based model to estimate the risk to people downstream of this dam. The agent-based model represents each individual person. The modelling indicated that if a warning had been issued as the dam failed, the number of fatalities could have been reduced.
Hasrul Hazman Hasan, Siti Fatin Mohd Razali, Nur Shazwani Muhammad, and Firdaus Mohamad Hamzah
Nat. Hazards Earth Syst. Sci., 21, 1–19,Short summary
This study aims to understand the concept of low-flow drought characteristics and the predictive significance of river storage draft rates in managing sustainable water catchment. This study consists of four types of analyses: streamflow trend analysis, low-flow frequency analysis, determination of the minimum storage draft rates and hydrological-drought characteristics. The results are useful for developing measures to maintain flow variability and can be used to develop water policies.
Anna E. Sikorska-Senoner, Bettina Schaefli, and Jan Seibert
Nat. Hazards Earth Syst. Sci., 20, 3521–3549,Short summary
This work proposes methods for reducing the computational requirements of hydrological simulations for the estimation of very rare floods that occur on average less than once in 1000 years. These methods enable the analysis of long streamflow time series (here for example 10 000 years) at low computational costs and with modelling uncertainty. They are to be used within continuous simulation frameworks with long input time series and are readily transferable to similar simulation tasks.
Matteo Balistrocchi, Rodolfo Metulini, Maurizio Carpita, and Roberto Ranzi
Nat. Hazards Earth Syst. Sci., 20, 3485–3500,Short summary
Flood risk is an increasing threat to urban communities and their strategical assets worldwide. Non-structural practices, such as emergency management plans, can be effective in order to decrease the flood risk in strongly urbanized areas. Mobile phone data provide reliable estimates of the spatiotemporal variability in people exposed to flooding, thus enhancing the preparedness of stakeholders involved in flood risk management. Further, practical advantages emerge with respect to crowdsourcing.
Guillaume Piton, Toshiyuki Horiguchi, Lise Marchal, and Stéphane Lambert
Nat. Hazards Earth Syst. Sci., 20, 3293–3314,Short summary
Open check dams are flood protection structures trapping sediment and large wood. Large wood obstructs openings of dams, thus increasing flow levels. If flow levels become higher than the dam crest, the trapped large wood may overtop the structure and be suddenly released downstream, which may also eventually obstruct downstream bridges. This paper is based on experiments on small-scale models. It shows how to compute the increase in flow level and conditions leading to sudden overtopping.
María Teresa Contreras, Jorge Gironás, and Cristián Escauriaza
Nat. Hazards Earth Syst. Sci., 20, 3261–3277,Short summary
The prediction of multiple scenarios of flood hazard in mountain regions is typically based on expensive high-resolution models that simulate the flood propagation using significant computational resources. In this investigation we develop a surrogate model that provides a rapid evaluation of the flood hazard using a statistical approach and precomputed scenarios. This surrogate model is an advanced tool that can be used for early warning systems and to help decision makers and city planners.
Jerom P. M. Aerts, Steffi Uhlemann-Elmer, Dirk Eilander, and Philip J. Ward
Nat. Hazards Earth Syst. Sci., 20, 3245–3260,Short summary
We compare and analyse flood hazard maps from eight global flood models that represent the current state of the global flood modelling community. We apply our comparison to China as a case study, and for the first time, we include industry models, pluvial flooding, and flood protection standards. We find substantial variability between the flood hazard maps in the modelled inundated area and exposed gross domestic product (GDP) across multiple return periods and in expected annual exposed GDP.
David J. Peres, Alfonso Senatore, Paola Nanni, Antonino Cancelliere, Giuseppe Mendicino, and Brunella Bonaccorso
Nat. Hazards Earth Syst. Sci., 20, 3057–3082,Short summary
Regional climate models (RCMs) are commonly used for high-resolution assessment of climate change impacts. This research assesses the reliability of several RCMs in a Mediterranean area (southern Italy), comparing historic climate and drought characteristics with high-density and high-quality ground-based observational datasets. We propose a general methodology and identify the more skilful models able to reproduce precipitation and temperature variability as well as drought characteristics.
Mathilde Erfurt, Georgios Skiadaresis, Erik Tijdeman, Veit Blauhut, Jürgen Bauhus, Rüdiger Glaser, Julia Schwarz, Willy Tegel, and Kerstin Stahl
Nat. Hazards Earth Syst. Sci., 20, 2979–2995,Short summary
Droughts are multifaceted hazards with widespread negative consequences for the environment and society. This study explores different perspectives on drought and determines the added value of multidisciplinary datasets for a comprehensive understanding of past drought events in southwestern Germany. A long-term evaluation of drought frequency since 1801 revealed that events occurred in all decades, but a particular clustering was found in the mid-19th century and the most recent decade.
Corrado Camera, Adriana Bruggeman, George Zittis, Ioannis Sofokleous, and Joël Arnault
Nat. Hazards Earth Syst. Sci., 20, 2791–2810,Short summary
Can numerical models simulate intense rainfall events and consequent streamflow in a mountainous area with small watersheds well? We applied state-of-the-art one-way-coupled atmospheric–hydrologic models and we found that, despite rainfall events simulated with low errors, large discrepancies between the observed and simulated streamflow were observed. Shifts in time and space of the modelled rainfall peak are the main reason. Still, the models can be applied for climate change impact studies.
Tigstu T. Dullo, Sudershan Gangrade, Mario Morales-Hernández, Md Bulbul Sharif, Alfred J. Kalyanapu, Shih-Chieh Kao, Sheikh Ghafoor, and Moetasim Ashfaq
Nat. Hazards Earth Syst. Sci. Discuss.,
Revised manuscript accepted for NHESS
Farhad Hooshyaripor, Sanaz Faraji-Ashkavar, Farshad Koohyian, Qiuhong Tang, and Roohollah Noori
Nat. Hazards Earth Syst. Sci., 20, 2739–2751,Short summary
The effect of El Niño on flood damage was investigated. The methodology was based on the calculation of increasing rainfall amount during El Niño events compared to normal conditions. With the southern oscillation index equal to −1.0 as the threshold of El Niño, the annual percentage of increased rainfall is 12.2 %. The annual change factor may not necessarily be transferred to extreme values. Nonetheless, the change factor was applied for generating simulated storms of different return periods.
Robert Jane, Luis Cadavid, Jayantha Obeysekera, and Thomas Wahl
Nat. Hazards Earth Syst. Sci., 20, 2681–2699,Short summary
Full dependence is assumed between drivers in flood protection assessments of coastal water control structures in south Florida. A 2-D analysis of rainfall and coastal water level showed that the magnitude of the conservative assumption in the original design is highly sensitive to the regional sea level rise projection considered. The vine copula and HT04 model outperformed five higher-dimensional copulas in capturing the dependence between rainfall, coastal water level, and groundwater level.
Punit K. Bhola, Jorge Leandro, and Markus Disse
Nat. Hazards Earth Syst. Sci., 20, 2647–2663,Short summary
In operational flood risk management, a single best model is used to assess the impact of flooding, which might misrepresent uncertainties in the modelling process. We have used quantified uncertainties in flood forecasting to generate flood hazard maps that were combined based on different exceedance probability scenarios with the purpose to differentiate impacts of flooding and to account for uncertainties in flood hazard maps that can be used by decision makers.
El Mahdi El Khalki, Yves Tramblay, Christian Massari, Luca Brocca, Vincent Simonneaux, Simon Gascoin, and Mohamed El Mehdi Saidi
Nat. Hazards Earth Syst. Sci., 20, 2591–2607,Short summary
In North Africa, the vulnerability to floods is high, and there is a need to improve the flood-forecasting systems. Remote-sensing and reanalysis data can palliate the lack of in situ measurements, in particular for soil moisture, which is a crucial parameter to consider when modeling floods. In this study we provide an evaluation of recent globally available soil moisture products for flood modeling in Morocco.
Barry Hankin, Ian Hewitt, Graham Sander, Federico Danieli, Giuseppe Formetta, Alissa Kamilova, Ann Kretzschmar, Kris Kiradjiev, Clint Wong, Sam Pegler, and Rob Lamb
Nat. Hazards Earth Syst. Sci., 20, 2567–2584,Short summary
With growing support for nature-based solutions to reduce flooding by local communities, government authorities and international organisations, it is still important to improve how we assess risk reduction. We demonstrate an efficient, simplified 1D network model that allows us to explore the
whole-systemresponse of numerous leaky barriers placed in different stream networks, whilst considering utilisation, synchronisation effects and cascade failure, and we provide advice on their siting.
Thomas O'Shea, Paul Bates, and Jeffrey Neal
Nat. Hazards Earth Syst. Sci., 20, 2281–2305,Short summary
Outlined here is a multi-disciplinary framework for analysing and evaluating the nature of vulnerability to, and capacity for, flood hazard within a complex urban society. It provides scope beyond the current, reified, descriptors of
flood riskand models the role of affected individuals within flooded areas. Using agent-based modelling coupled with the LISFLOOD-FP hydrodynamic model, potentially influential behaviours that give rise to the flood hazard system are identified and discussed.
Eklavyya Popat and Petra Döll
Nat. Hazards Earth Syst. Sci. Discuss.,
Revised manuscript accepted for NHESSShort summary
Two drought hazard indices are presented that combine the drought deficit and anomaly aspects: one for soil moisture drought (SMDAI), where we simplified the DSI and the other for streamflow drought (QDAI), to our knowledge, is the first-ever deficit-anomaly drought index including surface water demand. Both indices are tested at the global scale with WaterGAP 2.2d outputs, provides more differentiated, spatial and temporal patterns distinguishing the actual degree of respective drought hazards.
Joan Estrany, Maurici Ruiz-Pérez, Raphael Mutzner, Josep Fortesa, Beatriz Nácher-Rodríguez, Miquel Tomàs-Burguera, Julián García-Comendador, Xavier Peña, Adolfo Calvo-Cases, and Francisco J. Vallés-Morán
Nat. Hazards Earth Syst. Sci., 20, 2195–2220,Short summary
A catastrophic flash-flood event hit the northeastern part of Mallorca in 2018, causing 13 casualties and impacting on the international opinion in one of the most important tourist resorts. The analysis of the rainfall–runoff processes illustrated an unprecedented flashy behaviour in Europe triggering the natural disaster. UAVs and hydrogeomorphological precision techniques were used as a rapid post-catastrophe decision-making tool, playing a key role during the rescue searching tasks.
Aynalem T. Tsegaw, Marie Pontoppidan, Erle Kristvik, Knut Alfredsen, and Tone M. Muthanna
Nat. Hazards Earth Syst. Sci., 20, 2133–2155,Short summary
Hydrological impacts of climate change are generally performed by following steps from global to regional climate modeling through data tailoring and hydrological modeling. Usually, the climate–hydrology chain primary focuses on medium to large catchments. To study impacts of climate change on small catchments, a high-resolution regional climate model and hydrological model are required. The results from high-resolution models help in proposing specific adaptation strategies for impacts.
Aloïs Tilloy, Bruce D. Malamud, Hugo Winter, and Amélie Joly-Laugel
Nat. Hazards Earth Syst. Sci., 20, 2091–2117,Short summary
Estimating risks induced by interacting natural hazards remains a challenge for practitioners. An approach to tackle this challenge is to use multivariate statistical models. Here we evaluate the efficacy of six models. The models are compared against synthetic data which are comparable to time series of environmental variables. We find which models are more appropriate to estimate relations between hazards in a range of cases. We highlight the benefits of this approach with two examples.
Sengphrachanh Phrakonkham, So Kazama, and Komori Daisuke
Nat. Hazards Earth Syst. Sci. Discuss.,
Revised manuscript accepted for NHESSShort summary
The main objective of this study was to propose a new approach to integrating hazard maps to detect hazardous areas on a national scale, for which area-limited data are available. The analytical hierarchy process (AHP) was used as a tool to combine the different hazard maps into an integrated hazard map. The results from integrated hazard maps can identify dangerous areas from both individual and integrated hazards.
Benjamin Winter, Klaus Schneeberger, Kristian Förster, and Sergiy Vorogushyn
Nat. Hazards Earth Syst. Sci., 20, 1689–1703,Short summary
In this paper two different methods to generate spatially coherent flood events for probabilistic flood risk modelling are compared: on the one hand, a semi-conditional multi-variate dependence model applied to discharge observations and, on the other hand, a continuous hydrological modelling of synthetic meteorological fields generated by a multi-site weather generator. The results of the two approaches are compared in terms of simulated spatial patterns and overall flood risk estimates.
Heiko Apel, Mai Khiem, Nguyen Hong Quan, and To Quang Toan
Nat. Hazards Earth Syst. Sci., 20, 1609–1616,Short summary
This study deals with salinity intrusion in the Mekong Delta, a pressing issue in the third-largest river delta on Earth. It presents a simple, efficient, and cross-validated seasonal forecast model for salinity intrusion during the dry season based on logistic regression using ENSO34 or standardized streamflow indexes as predictors. The model performs exceptionally well, enabling a reliable forecast of critical salinity threshold exceedance up to 9 months prior to the dry season.
Samuel J. Sutanto, Melati van der Weert, Veit Blauhut, and Henny A. J. Van Lanen
Nat. Hazards Earth Syst. Sci., 20, 1595–1608,Short summary
Present-day drought early warning systems only provide information on drought hazard forecasts. Here, we have developed drought impact functions to forecast drought impacts up to 7 months ahead using machine learning techniques, logistic regression, and random forest. Our results show that random forest produces a higher-impact forecasting skill than logistic regression. For German county levels, drought impacts can be forecasted up to 4 months ahead using random forest.
Giuliano Di Baldassarre, Fernando Nardi, Antonio Annis, Vincent Odongo, Maria Rusca, and Salvatore Grimaldi
Nat. Hazards Earth Syst. Sci., 20, 1415–1419,Short summary
Global floodplain mapping has rapidly progressed over the past few years. Different methods have been proposed to identify areas prone to river flooding, resulting in a plethora of available products. Here we assess the potential and limitations of two main paradigms and provide guidance on the use of these global products in assessing flood risk in data-poor regions.
Shraddhanand Shukla, Kristi R. Arsenault, Abheera Hazra, Christa Peters-Lidard, Randal D. Koster, Frank Davenport, Tamuka Magadzire, Chris Funk, Sujay Kumar, Amy McNally, Augusto Getirana, Greg Husak, Ben Zaitchik, Jim Verdin, Faka Dieudonne Nsadisa, and Inbal Becker-Reshef
Nat. Hazards Earth Syst. Sci., 20, 1187–1201,Short summary
The region of southern Africa is prone to climate-driven food insecurity events, as demonstrated by the major drought event in 2015–2016. This study demonstrates that recently developed NASA Hydrological Forecasting and Analysis System-based root-zone soil moisture monitoring and forecasting products are well correlated with interannual regional crop yield, can identify below-normal crop yield events and provide skillful crop yield forecasts, and hence support early warning of food insecurity.
Dennis Wagenaar, Alex Curran, Mariano Balbi, Alok Bhardwaj, Robert Soden, Emir Hartato, Gizem Mestav Sarica, Laddaporn Ruangpan, Giuseppe Molinario, and David Lallemant
Nat. Hazards Earth Syst. Sci., 20, 1149–1161,Short summary
This invited perspective paper addresses how machine learning may change flood risk and impact assessments. It goes through different modelling components and provides an analysis of how current assessments are done without machine learning, current applications of machine learning and potential future improvements. It is based on a 2-week-long intensive collaboration among experts from around the world during the Understanding Risk Field lab on urban flooding in June 2019.
Ayse Duha Metin, Nguyen Viet Dung, Kai Schröter, Sergiy Vorogushyn, Björn Guse, Heidi Kreibich, and Bruno Merz
Nat. Hazards Earth Syst. Sci., 20, 967–979,Short summary
For effective risk management, flood risk should be properly assessed. Traditionally, risk is assessed by making the assumption of invariant flow or loss probabilities (the chance that a given discharge or loss is exceeded) within the river catchment during a single flood event. However, in reality, flooding is more severe in some regions than others. This study indicates the importance of representing the spatial dependence of flood peaks and damage for risk assessments.
Isabelle Braud, Lilly-Rose Lagadec, Loïc Moulin, Blandine Chazelle, and Pascal Breil
Nat. Hazards Earth Syst. Sci., 20, 947–966,Short summary
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.
Alexandre M. Ramos, Pedro M. Sousa, Emanuel Dutra, and Ricardo M. Trigo
Nat. Hazards Earth Syst. Sci., 20, 877–888,
Rubén Moratiel, Raquel Bravo, Antonio Saa, Ana M. Tarquis, and Javier Almorox
Nat. Hazards Earth Syst. Sci., 20, 859–875,Short summary
The estimation of ETo using temperature is particularly attractive in places where air humidity, wind speed and solar radiation data are not readily available. In this study we used, for the estimation of ETo, seven models against Penman–Monteith FAO 56 with temporal (annual and seasonal) and spatial perspective over Duero basin (Spain). The results of the tested models can be useful for adopting appropriate measures for efficient water management under the limitation of agrometeorological data.
Kenichiro Kobayashi, Le Duc, Apip, Tsutao Oizumi, and Kazuo Saito
Nat. Hazards Earth Syst. Sci., 20, 755–770,Short summary
The 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 is not possible by the single deterministic forecast. The necessity of emergency flood operation was shown with a long leading time. This suggests that it is worth investing in increasing numbers of meteorological ensembles to improve flood forecasting.
Michael L. Follum, Ricardo Vera, Ahmad A. Tavakoly, and Joseph L. Gutenson
Nat. Hazards Earth Syst. Sci., 20, 625–641,Short summary
AutoRoute is one of the tools used by the US Military to create high-resolution flood inundation maps at regional to continental scales. Although proven to be useful in simulating floods in remote regions of the world, the accuracy of the model has had only limited testing for nonextreme flood cases. This paper presents improvements to AutoRoute to accurately simulate both extreme and nonextreme flood cases while improving the applicability in a production setting.
Anaïs Couasnon, Dirk Eilander, Sanne Muis, Ted I. E. Veldkamp, Ivan D. Haigh, Thomas Wahl, Hessel C. Winsemius, and Philip J. Ward
Nat. Hazards Earth Syst. Sci., 20, 489–504,Short summary
When a high river discharge coincides with a high storm surge level, this can exarcebate flood level, depth, and duration, resulting in a so-called compound flood event. These events are not currently included in global flood models. In this research, we analyse the timing and correlation between modelled discharge and storm surge level time series in deltas and estuaries. Our results provide a first indication of regions along the global coastline with a high compound flooding potential.
Beatrice Monteleone, Brunella Bonaccorso, and Mario Martina
Nat. Hazards Earth Syst. Sci., 20, 471–487,Short summary
This study proposes a new drought index that combines meteorological and agricultural drought aspects. The index is scalable, transferable all over the globe, can be updated in near real time and is a remote-sensing product, since only satellite-based datasets were employed. A set of rules to objectively identify drought events is also implemented. We found that the set of rules, applied together with the new index, outperformed conventional drought indices in identifying droughts in Haiti.
Hélène Roux, Arnau Amengual, Romu Romero, Ernest Bladé, and Marcos Sanz-Ramos
Nat. Hazards Earth Syst. Sci., 20, 425–450,Short summary
The performances of flash-flood forecasts are evaluated using a meteorological model forcing a rainfall-runoff model. Both deterministic (single forecast of the most likely weather) and ensemble forecasts (set or ensemble of forecasts) have been produced on three subcatchments of the eastern Pyrenees exhibiting different rainfall regimes. Results show that both overall discharge forecast and flood warning are improved by the ensemble strategies with respect to the deterministic forecast.
María Teresa Contreras and Cristián Escauriaza
Nat. Hazards Earth Syst. Sci., 20, 221–241,Short summary
In this investigation we study the effects of high sediment concentrations on the dynamics of flash floods in mountain regions, with an application to a river in the Andes that has produced catastrophic events in the city of Santiago, Chile. We develop an advanced computational model to understand the effects of floods with high sediment loads on steep channels. These new insights can be used to design early warning systems and contribute to urban planning in cities near mountain rivers.
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An alluvial Mediterranean river changed its riverine and deltaic landscape. The delta has been heavily retreating (up to 800 m) for more than a century. We focus on the river, channelized in the last 50 years, trying to link its sandy sediment yield to the delta evolution. Sediment availability in the last 30 km of the river channel is deemed responsible for the decrease in the sediment yield to the delta. Sediment supply reduction to the coast jeopardizes the future of the delta and beaches.
An alluvial Mediterranean river changed its riverine and deltaic landscape. The delta has been...