Articles | Volume 22, issue 1
https://doi.org/10.5194/nhess-22-187-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/nhess-22-187-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
28 Jan 2022
Research article |
| 28 Jan 2022
| 28 Jan 2022
Investigating the interaction of waves and river discharge during compound flooding at Breede Estuary, South Africa
Sunna Kupfer
CORRESPONDING AUTHOR
Coastal Risks and Sea-Level Rise Research Group, Department of Geography, Christian-Albrechts University, Kiel, Germany
Sara Santamaria-Aguilar
Coastal Risks and Sea-Level Rise Research Group, Department of Geography, Christian-Albrechts University, Kiel, Germany
Lara van Niekerk
Coastal Systems Research Group, Council for Scientific and Industrial Research CSIR, Stellenbosch, 7600, South Africa
Institute for Coastal and Marine Research, Nelson Mandela University, P.O. Box 77000, Port Elizabeth, 6031, South Africa
Melanie Lück-Vogel
Coastal Systems Research Group, Council for Scientific and Industrial Research CSIR, Stellenbosch, 7600, South Africa
Department for Geography and Environmental Studies, Stellenbosch University, Stellenbosch, 7600, South Africa
Athanasios T. Vafeidis
Coastal Risks and Sea-Level Rise Research Group, Department of Geography, Christian-Albrechts University, Kiel, Germany
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Pravin Maduwantha, Thomas Wahl, Sara Santamaria-Aguilar, Robert Jane, James F. Booth, Hanbeen Kim, and Gabriele Villarini
Nat. Hazards Earth Syst. Sci., 24, 4091–4107, https://doi.org/10.5194/nhess-24-4091-2024, https://doi.org/10.5194/nhess-24-4091-2024, 2024
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When assessing the likelihood of compound flooding, most studies ignore that it can arise from different storm types with distinct statistical characteristics. Here, we present a new statistical framework that accounts for these differences and shows how neglecting these can impact the likelihood of compound flood potential.
Giulia Galluccio, Jochen Hinkel, Elisa Fiorini Beckhauser, Alexander Bisaro, Rebeca Biancardi Aleu, Pierpaolo Campostrini, Maria Florencia Casas, Océane Espin, and Athanasios T. Vafeidis
State Planet, 3-slre1, 6, https://doi.org/10.5194/sp-3-slre1-6-2024, https://doi.org/10.5194/sp-3-slre1-6-2024, 2024
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The paper synthesises knowledge of European sea level rise (SLR), guiding evidence-based policy. SLR poses challenges for coastal decision-making addressed through hard and soft strategies across sea basins: incorporation of SLR projections into spatial planning, focus on adaptation plans and nature-based solutions and priorisation of early-warning systems. The study stresses key coastal adaptation considerations, e.g. flexibility, integration of SLR information and iterative decision-making.
Joshua Kiesel, Marvin Lorenz, Marcel König, Ulf Gräwe, and Athanasios T. Vafeidis
Nat. Hazards Earth Syst. Sci., 23, 2961–2985, https://doi.org/10.5194/nhess-23-2961-2023, https://doi.org/10.5194/nhess-23-2961-2023, 2023
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Among the Baltic Sea littoral states, Germany is anticipated to experience considerable damage as a result of increased coastal flooding due to sea-level rise (SLR). Here we apply a new modelling framework to simulate how flooding along the German Baltic Sea coast may change until 2100 if dikes are not upgraded. We find that the study region is highly exposed to flooding, and we emphasise the importance of current plans to update coastal protection in the future.
Athanasios T. Vafeidis, Mark Schuerch, Claudia Wolff, Tom Spencer, Jan L. Merkens, Jochen Hinkel, Daniel Lincke, Sally Brown, and Robert J. Nicholls
Nat. Hazards Earth Syst. Sci., 19, 973–984, https://doi.org/10.5194/nhess-19-973-2019, https://doi.org/10.5194/nhess-19-973-2019, 2019
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This paper evaluates the effect of surge water level reduction due to land surface characteristics when assessing flood impacts at global scales. Our results show that uncertainties due to not accounting for water attenuation are of similar magnitude to the uncertainties regarding the total amount of sea-level rise expected by 2100, thus highlighting the need for better understanding of the spatial and temporal variation of water levels across floodplains.
Kristian Kumbier, Rafael C. Carvalho, Athanasios T. Vafeidis, and Colin D. Woodroffe
Nat. Hazards Earth Syst. Sci., 18, 463–477, https://doi.org/10.5194/nhess-18-463-2018, https://doi.org/10.5194/nhess-18-463-2018, 2018
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This study investigates compound flooding in an estuary by quantifying horizontal (flood extent) and vertical differences (inundation depth) in flood risk estimates resulting from a separation of storm surge and river flooding. Results demonstrated large underestimation of flood risk when river discharge was excluded. We recommend considering storm surge and river flooding processes jointly in estuaries with large catchment areas which are known to have a quick response time to extreme rainfall.
Athanasios T. Vafeidis, Mark Schuerch, Claudia Wolff, Tom Spencer, Jan L. Merkens, Jochen Hinkel, Daniel Lincke, Sally Brown, and Robert J. Nicholls
Nat. Hazards Earth Syst. Sci. Discuss., https://doi.org/10.5194/nhess-2017-199, https://doi.org/10.5194/nhess-2017-199, 2017
Manuscript not accepted for further review
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Global assessments of coastal flooding are based on the assumption that water propagation follows a
bathtubpattern across the floodplain. Using a global model we find that this assumption can lead to overestimation of impacts, with an uncertainty range that can be of equal magnitude to uncertainties related to future sea-level rise. Our results highlight the importance of improving the representation of the spatial/temporal variation of water levels across floodplains of different landcover.
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Nat. Hazards Earth Syst. Sci., 24, 4049–4074, https://doi.org/10.5194/nhess-24-4049-2024, https://doi.org/10.5194/nhess-24-4049-2024, 2024
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Robert McCall, Curt Storlazzi, Floortje Roelvink, Stuart G. Pearson, Roel de Goede, and José A. Á. Antolínez
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Jean H. M. Roger and Bernard Pelletier
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Kévin Dubois, Morten Andreas Dahl Larsen, Martin Drews, Erik Nilsson, and Anna Rutgersson
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Sergio Padilla, Íñigo Aniel-Quiroga, Rachid Omira, Mauricio González, Jihwan Kim, and Maria A. Baptista
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The eruption of the Hunga Tonga–Hunga Ha'apai volcano in January 2022 triggered a global phenomenon, including an atmospheric wave and a volcano-meteorological tsunami (VMT). The tsunami, reaching as far as Callao, Peru, 10 000 km away, caused significant coastal impacts. This study delves into understanding these effects, particularly on vessel mooring safety. The findings underscore the importance of enhancing early warning systems and preparing port authorities for managing such rare events.
Alice Abbate, José M. González Vida, Manuel J. Castro Díaz, Fabrizio Romano, Hafize Başak Bayraktar, Andrey Babeyko, and Stefano Lorito
Nat. Hazards Earth Syst. Sci., 24, 2773–2791, https://doi.org/10.5194/nhess-24-2773-2024, https://doi.org/10.5194/nhess-24-2773-2024, 2024
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Modelling tsunami generation due to a rapid submarine earthquake is a complex problem. Under a variety of realistic conditions in a subduction zone, we propose and test an efficient solution to this problem: a tool that can compute the generation of any potential tsunami in any ocean in the world. In the future, we will explore solutions that would also allow us to model tsunami generation by slower (time-dependent) seafloor displacement.
Joshua Green, Ivan Haigh, Niall Quinn, Jeff Neal, Thomas Wahl, Melissa Wood, Dirk Eilander, Marleen de Ruiter, Philip Ward, and Paula Camus
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Compound flooding, involving the combination or successive occurrence of two or more flood drivers, can amplify flood impacts in coastal/estuarine regions. This paper reviews the practices, trends, methodologies, applications, and findings of coastal compound flooding literature at regional to global scales. We explore the types of compound flood events, their mechanistic processes, and the range of terminology. Lastly, this review highlights knowledge gaps and implications for future practices.
Mithun Deb, James J. Benedict, Ning Sun, Zhaoqing Yang, Robert D. Hetland, David Judi, and Taiping Wang
Nat. Hazards Earth Syst. Sci., 24, 2461–2479, https://doi.org/10.5194/nhess-24-2461-2024, https://doi.org/10.5194/nhess-24-2461-2024, 2024
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We coupled earth system, hydrology, and hydrodynamic models to generate plausible and physically consistent ensembles of hurricane events and their associated water levels from the open coast to tidal rivers of Delaware Bay and River. Our results show that the hurricane landfall locations and the estuarine wind can significantly amplify the extreme surge in a shallow and converging system, especially when the wind direction aligns with the surge propagation direction.
Ming-Huei Chang, Yen-Chen Huang, Yu-Hsin Cheng, Chuen-Teyr Terng, Jinyi Chen, and Jyh Cherng Jan
Nat. Hazards Earth Syst. Sci., 24, 2481–2494, https://doi.org/10.5194/nhess-24-2481-2024, https://doi.org/10.5194/nhess-24-2481-2024, 2024
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Monitoring the long-term trends in sea surface warming is crucial for informed decision-making and adaptation. This study offers a comprehensive examination of prevalent trend extraction methods. We identify the least-squares regression as suitable for general tasks yet highlight the need to address seasonal signal-induced bias, i.e., the phase–distance imbalance. Our developed method, evaluated using simulated and real data, is unbiased and better than the conventional SST anomaly method.
Thomas P. Collings, Niall D. Quinn, Ivan D. Haigh, Joshua Green, Izzy Probyn, Hamish Wilkinson, Sanne Muis, William V. Sweet, and Paul D. Bates
Nat. Hazards Earth Syst. Sci., 24, 2403–2423, https://doi.org/10.5194/nhess-24-2403-2024, https://doi.org/10.5194/nhess-24-2403-2024, 2024
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Coastal areas are at risk of flooding from rising sea levels and extreme weather events. This study applies a new approach to estimating the likelihood of coastal flooding around the world. The method uses data from observations and computer models to create a detailed map of where these coastal floods might occur. The approach can predict flooding in areas for which there are few or no data available. The results can be used to help prepare for and prevent this type of flooding.
Guangsheng Zhao and Xiaojing Niu
Nat. Hazards Earth Syst. Sci., 24, 2303–2313, https://doi.org/10.5194/nhess-24-2303-2024, https://doi.org/10.5194/nhess-24-2303-2024, 2024
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The purpose of this study is to estimate the spatial distribution of the tsunami hazard in the South China Sea from the Manila subduction zone. The plate motion data are used to invert the degree of locking on the fault plane. The degree of locking is used to estimate the maximum possible magnitude of earthquakes and describe the slip distribution. A spatial distribution map of the 1000-year return period tsunami wave height in the South China Sea was obtained by tsunami hazard assessment.
Mandana Ghanavati, Ian R. Young, Ebru Kirezci, and Jin Liu
Nat. Hazards Earth Syst. Sci., 24, 2175–2190, https://doi.org/10.5194/nhess-24-2175-2024, https://doi.org/10.5194/nhess-24-2175-2024, 2024
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The paper examines the changes in shoreline position of the coast of south-east Australia over a 26-year period to determine whether changes are consistent with observed changes in ocean wave and storm surge climate. The results show that in regions where there have been significant changes in wave energy flux or wave direction, there have also been changes in shoreline position consistent with non-equilibrium longshore drift.
Ina Teutsch, Ralf Weisse, and Sander Wahls
Nat. Hazards Earth Syst. Sci., 24, 2065–2069, https://doi.org/10.5194/nhess-24-2065-2024, https://doi.org/10.5194/nhess-24-2065-2024, 2024
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We investigate buoy and radar measurement data from shallow depths in the southern North Sea. We analyze the role of solitons for the occurrence of rogue waves. This is done by computing the nonlinear soliton spectrum of each time series. In a previous study that considered a single measurement site, we found a connection between the shape of the soliton spectrum and the occurrence of rogue waves. In this study, results for two additional sites are reported.
Marc Igigabel, Marissa Yates, Michalis Vousdoukas, and Youssef Diab
Nat. Hazards Earth Syst. Sci., 24, 1951–1974, https://doi.org/10.5194/nhess-24-1951-2024, https://doi.org/10.5194/nhess-24-1951-2024, 2024
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Changes in sea levels alone do not determine the evolution of coastal hazards. Coastal hazard changes should be assessed using additional factors describing geomorphological configurations, metocean event types (storms, cyclones, long swells, and tsunamis), and the marine environment (e.g., coral reef state and sea ice extent). The assessment completed here, at regional scale including the coasts of mainland and overseas France, highlights significant differences in hazard changes.
Jani Särkkä, Jani Räihä, Mika Rantanen, and Matti Kämäräinen
Nat. Hazards Earth Syst. Sci., 24, 1835–1842, https://doi.org/10.5194/nhess-24-1835-2024, https://doi.org/10.5194/nhess-24-1835-2024, 2024
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We study the relationship between tracks of low-pressure systems and related sea level extremes. We perform the studies by introducing a method to simulate sea levels using synthetic low-pressure systems. We test the method using sites located along the Baltic Sea coast. We find high extremes, where the sea level extreme reaches up to 3.5 m. In addition, we add the maximal value of the mean level of the Baltic Sea (1 m), leading to a sea level of 4.5 m.
Alexey Androsov, Sven Harig, Natalia Zamora, Kim Knauer, and Natalja Rakowsky
Nat. Hazards Earth Syst. Sci., 24, 1635–1656, https://doi.org/10.5194/nhess-24-1635-2024, https://doi.org/10.5194/nhess-24-1635-2024, 2024
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Two numerical codes are used in a comparative analysis of the calculation of the tsunami wave due to an earthquake along the Peruvian coast. The comparison primarily evaluates the flow velocity fields in flooded areas. The relative importance of the various parts of the equations is determined, focusing on the nonlinear terms. The influence of the nonlinearity on the degree and volume of flooding, flow velocity, and small-scale fluctuations is determined.
Eric Mortensen, Timothy Tiggeloven, Toon Haer, Bas van Bemmel, Dewi Le Bars, Sanne Muis, Dirk Eilander, Frederiek Sperna Weiland, Arno Bouwman, Willem Ligtvoet, and Philip J. Ward
Nat. Hazards Earth Syst. Sci., 24, 1381–1400, https://doi.org/10.5194/nhess-24-1381-2024, https://doi.org/10.5194/nhess-24-1381-2024, 2024
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Current levels of coastal flood risk are projected to increase in coming decades due to various reasons, e.g. sea-level rise, land subsidence, and coastal urbanization: action is needed to minimize this future risk. We evaluate dykes and coastal levees, foreshore vegetation, zoning restrictions, and dry-proofing on a global scale to estimate what levels of risk reductions are possible. We demonstrate that there are several potential adaptation pathways forward for certain areas of the world.
Charlotte Lyddon, Nguyen Chien, Grigorios Vasilopoulos, Michael Ridgill, Sogol Moradian, Agnieszka Olbert, Thomas Coulthard, Andrew Barkwith, and Peter Robins
Nat. Hazards Earth Syst. Sci., 24, 973–997, https://doi.org/10.5194/nhess-24-973-2024, https://doi.org/10.5194/nhess-24-973-2024, 2024
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Recent storms in the UK, like Storm Ciara in 2020, show how vulnerable estuaries are to the combined effect of sea level and river discharge. We show the combinations of sea levels and river discharges that cause flooding in the Conwy estuary, N Wales. The results showed flooding was amplified under moderate conditions in the middle estuary and elsewhere sea state or river flow dominated the hazard. Combined sea and river thresholds can improve prediction and early warning of compound flooding.
Shuaib Rasheed, Simon C. Warder, Yves Plancherel, and Matthew D. Piggott
Nat. Hazards Earth Syst. Sci., 24, 737–755, https://doi.org/10.5194/nhess-24-737-2024, https://doi.org/10.5194/nhess-24-737-2024, 2024
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Here we use a high-resolution bathymetry dataset of the Maldives archipelago, as well as corresponding high numerical model resolution, to carry out a scenario-based tsunami hazard assessment for the entire Maldives archipelago to investigate the potential impact of plausible far-field tsunamis across the Indian Ocean at the island scale. The results indicate that several factors contribute to mitigating and amplifying tsunami waves at the island scale.
Niels J. Korsgaard, Kristian Svennevig, Anne S. Søndergaard, Gregor Luetzenburg, Mimmi Oksman, and Nicolaj K. Larsen
Nat. Hazards Earth Syst. Sci., 24, 757–772, https://doi.org/10.5194/nhess-24-757-2024, https://doi.org/10.5194/nhess-24-757-2024, 2024
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A tsunami wave will leave evidence of erosion and deposition in coastal lakes, making it possible to determine the runup height and when it occurred. Here, we use four lakes now located at elevations of 19–91 m a.s.l. close to the settlement of Saqqaq, West Greenland, to show that at least two giant tsunamis occurred 7300–7600 years ago with runup heights larger than 40 m. We infer that any tsunamis from at least nine giga-scale landslides must have happened 8500–10 000 years ago.
Elke Magda Inge Meyer and Lidia Gaslikova
Nat. Hazards Earth Syst. Sci., 24, 481–499, https://doi.org/10.5194/nhess-24-481-2024, https://doi.org/10.5194/nhess-24-481-2024, 2024
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Storm tides for eight extreme historical storms in the German Bight are modelled using sets of slightly varying atmospheric conditions from the century reanalyses. Comparisons with the water level observations from the gauges Norderney, Cuxhaven and Husum show that single members of the reanalyses are suitable for the reconstruction of extreme storms. Storms with more northerly tracks show less variability within a set and have more potential for accurate reconstruction of extreme water levels.
Clare Lewis, Tim Smyth, Jess Neumann, and Hannah Cloke
Nat. Hazards Earth Syst. Sci., 24, 121–131, https://doi.org/10.5194/nhess-24-121-2024, https://doi.org/10.5194/nhess-24-121-2024, 2024
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Meteotsunami are the result of atmospheric disturbances and can impact coastlines causing injury, loss of life, and damage to assets. This paper introduces a novel intensity index to allow for the quantification of these events at the shoreline. This has the potential to assist in the field of natural hazard assessment. It was trialled in the UK but designed for global applicability and to become a widely accepted standard in coastal planning, meteotsunami forecasting, and early warning systems.
Wiwin Windupranata, Muhammad Wahyu Al Ghifari, Candida Aulia De Silva Nusantara, Marsyanisa Shafa, Intan Hayatiningsih, Iyan Eka Mulia, and Alqinthara Nuraghnia
EGUsphere, https://doi.org/10.5194/egusphere-2023-2860, https://doi.org/10.5194/egusphere-2023-2860, 2024
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Batukaras Village is a village on the southern coast of Java Island which is prone to tsunami hazards. To assess the potential tsunami hazard in the area, PTHA method was employed. It resulted in tsunami heights of 0.84 m, 1.63 m, 2.97 m, and 5.7 m for each earthquake return period of 250 years, 500 years, 1000 years, and 2500 years, respectively. The largest contribution of earthquake sources comes from the West Java-Central Java megathrust segment.
Chu-En Hsu, Katherine A. Serafin, Xiao Yu, Christie A. Hegermiller, John C. Warner, and Maitane Olabarrieta
Nat. Hazards Earth Syst. Sci., 23, 3895–3912, https://doi.org/10.5194/nhess-23-3895-2023, https://doi.org/10.5194/nhess-23-3895-2023, 2023
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Total water levels (TWLs) induced by tropical cyclones (TCs) are among the leading hazards faced by coastal communities. Using numerical models, we examined how TWL components (surge and wave runup) along the South Atlantic Bight varied during hurricanes Matthew (2016), Dorian (2019), and Isaias (2020). Peak surge and peak wave runup were dominated by wind speeds and relative positions to TCs. The exceedance time of TWLs was controlled by normalized distances to TC and TC translation speeds.
Enrico Duo, Juan Montes, Marine Le Gal, Tomás Fernández-Montblanc, Paolo Ciavola, and Clara Armaroli
Nat. Hazards Earth Syst. Sci. Discuss., https://doi.org/10.5194/nhess-2023-197, https://doi.org/10.5194/nhess-2023-197, 2023
Revised manuscript accepted for NHESS
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The present work, developed within the EU H2020 European Coastal Flood Awareness System ECFAS project, presents an approach used to estimate coastal flood direct impacts on population, buildings, and roads along the European coasts. The findings demonstrate that the ECFAS Impact approach offers valuable estimates for affected populations, reliable damage assessments for buildings and roads, and improved accuracy compared to traditional grid-based approaches.
Maude Biguenet, Eric Chaumillon, Pierre Sabatier, Antoine Bastien, Emeline Geba, Fabien Arnaud, Thibault Coulombier, and Nathalie Feuillet
Nat. Hazards Earth Syst. Sci., 23, 3761–3788, https://doi.org/10.5194/nhess-23-3761-2023, https://doi.org/10.5194/nhess-23-3761-2023, 2023
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This work documents the impact of Hurricane Irma (2017) on the Codrington barrier and lagoon on Barbuda Island. Irma caused two wide breaches in the sandy barrier, which remained unopened for 250 years. The thick and extensive sand sheet at the top of the lagoon fill was attributed to Irma. This unique deposit in a 3700-year record confirms Irma's exceptional character. This case study illustrates the consequences of high-intensity hurricanes in low-lying islands in a global warming context.
Leigh Richard MacPherson, Arne Arns, Svenja Fischer, Fernando Javier Méndez, and Jürgen Jensen
Nat. Hazards Earth Syst. Sci., 23, 3685–3701, https://doi.org/10.5194/nhess-23-3685-2023, https://doi.org/10.5194/nhess-23-3685-2023, 2023
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Efficient adaptation planning for coastal flooding caused by extreme sea levels requires accurate assessments of the underlying hazard. Tide-gauge data alone are often insufficient for providing the desired accuracy but may be supplemented with historical information. We estimate extreme sea levels along the German Baltic coast and show that relying solely on tide-gauge data leads to underestimations. Incorporating historical information leads to improved estimates with reduced uncertainties.
Anne Margaret H. Smiley, Suzanne P. Thompson, Nathan S. Hall, and Michael F. Piehler
Nat. Hazards Earth Syst. Sci., 23, 3635–3649, https://doi.org/10.5194/nhess-23-3635-2023, https://doi.org/10.5194/nhess-23-3635-2023, 2023
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Floodwaters can deliver reactive nitrogen to sensitive aquatic systems and diminish water quality. We assessed the nitrogen removal capabilities of flooded habitats and urban landscapes. Differences in processing rates across land cover treatments and between nutrient treatments suggest that abundance and spatial distributions of habitats, as well as storm characteristics, influence landscape-scale nitrogen removal. Results have important implications for coastal development and climate change.
Marine Le Gal, Tomás Fernández-Montblanc, Enrico Duo, Juan Montes Perez, Paulo Cabrita, Paola Souto Ceccon, Véra Gastal, Paolo Ciavola, and Clara Armaroli
Nat. Hazards Earth Syst. Sci., 23, 3585–3602, https://doi.org/10.5194/nhess-23-3585-2023, https://doi.org/10.5194/nhess-23-3585-2023, 2023
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Assessing coastal hazards is crucial to mitigate flooding disasters. In this regard, coastal flood databases are valuable tools. This paper describes a new coastal flood map catalogue covering the entire European coastline, as well as the methodology to build it and its accuracy. The catalogue focuses on frequent extreme events and relies on synthetic scenarios estimated from local storm conditions. Flood-prone areas and regions sensitive to storm duration and water level peak were identified.
Neng-Ti Yu, Cheng-Hao Lu, I-Chin Yen, Jia-Hong Chen, Jiun-Yee Yen, and Shyh-Jeng Chyi
Nat. Hazards Earth Syst. Sci., 23, 3525–3542, https://doi.org/10.5194/nhess-23-3525-2023, https://doi.org/10.5194/nhess-23-3525-2023, 2023
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A paleotsunami deposit of cliff-top basalt debris was identified on the Penghu Islands in the southern Taiwan Strait and related to the 1661 earthquake in southwest Taiwan. A minimum wave height of 3.2 m is estimated to have rotated the biggest boulder for over 30 m landwards onto the cliff top at 2.5 m a.s.l. The event must have been huge compared to the 1994 M 6.4 earthquake with the ensuing 0.4 m high tsunami in the same area, validating the intimidating tsunami risks in the South China Sea.
Ye Yuan, Huaiwei Yang, Fujiang Yu, Yi Gao, Benxia Li, and Chuang Xing
Nat. Hazards Earth Syst. Sci., 23, 3487–3507, https://doi.org/10.5194/nhess-23-3487-2023, https://doi.org/10.5194/nhess-23-3487-2023, 2023
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Rip currents are narrow jets of offshore-directed flow that originated in the surf zone, which can take swimmers of all ability levels into deeper water unawares. In this study, a 1 m fine-resolution wave-resolving model was configured to study rip current variability and the optimal swimmer escape strategies. Multiple factors contribute to the survival of swimmers. However, for weak-to-moderate rip and longshore currents, swimming onshore consistently seems to be the most successful strategy.
Benedikt Mester, Thomas Vogt, Seth Bryant, Christian Otto, Katja Frieler, and Jacob Schewe
Nat. Hazards Earth Syst. Sci., 23, 3467–3485, https://doi.org/10.5194/nhess-23-3467-2023, https://doi.org/10.5194/nhess-23-3467-2023, 2023
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In 2019, Cyclone Idai displaced more than 478 000 people in Mozambique. In our study, we use coastal flood modeling and satellite imagery to construct a counterfactual cyclone event without the effects of climate change. We show that 12 600–14 900 displacements can be attributed to sea level rise and the intensification of storm wind speeds due to global warming. Our impact attribution study is the first one on human displacement and one of very few for a low-income country.
Olivier Cavalié, Frédéric Cappa, and Béatrice Pinel-Puysségur
Nat. Hazards Earth Syst. Sci., 23, 3235–3246, https://doi.org/10.5194/nhess-23-3235-2023, https://doi.org/10.5194/nhess-23-3235-2023, 2023
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Coastal areas are fragile ecosystems that face multiple hazards. In this study, we measured the downward motion of the Nice Côte d'Azur Airport (France) that was built on reclaimed area and found that it has subsided from 16 mm yr-1 in the 1990s to 8 mm yr-1 today. A continuous remote monitoring of the platform will provide key data for a detailed investigation of future subsidence maps, and this contribution will help to evaluate the potential failure of part of the airport platform.
Wagner L. L. Costa, Karin R. Bryan, and Giovanni Coco
Nat. Hazards Earth Syst. Sci., 23, 3125–3146, https://doi.org/10.5194/nhess-23-3125-2023, https://doi.org/10.5194/nhess-23-3125-2023, 2023
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For predicting flooding events at the coast, topo-bathymetric data are essential. However, elevation data can be unavailable. To tackle this issue, recent efforts have centred on the use of satellite-derived topography (SDT) and bathymetry (SDB). This work is aimed at evaluating their accuracy and use for flooding prediction in enclosed estuaries. Results show that the use of SDT and SDB in numerical modelling can produce similar predictions when compared to the surveyed elevation data.
Joshua Kiesel, Marvin Lorenz, Marcel König, Ulf Gräwe, and Athanasios T. Vafeidis
Nat. Hazards Earth Syst. Sci., 23, 2961–2985, https://doi.org/10.5194/nhess-23-2961-2023, https://doi.org/10.5194/nhess-23-2961-2023, 2023
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Among the Baltic Sea littoral states, Germany is anticipated to experience considerable damage as a result of increased coastal flooding due to sea-level rise (SLR). Here we apply a new modelling framework to simulate how flooding along the German Baltic Sea coast may change until 2100 if dikes are not upgraded. We find that the study region is highly exposed to flooding, and we emphasise the importance of current plans to update coastal protection in the future.
Zhang Haixia, Cheng Meng, and Fang Weihua
Nat. Hazards Earth Syst. Sci., 23, 2697–2717, https://doi.org/10.5194/nhess-23-2697-2023, https://doi.org/10.5194/nhess-23-2697-2023, 2023
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Simultaneous storm surge and waves can cause great damage due to cascading effects. Quantitative joint probability analysis is critical to determine their optimal protection design values. The joint probability of the surge and wave for the eastern coasts of Leizhou Peninsula and Hainan are estimated with a Gumbel copula based on 62 years of numerically simulated data, and the optimal design values under various joint return periods are derived using the non-linear programming method.
Clare Lewis, Tim Smyth, David Williams, Jess Neumann, and Hannah Cloke
Nat. Hazards Earth Syst. Sci., 23, 2531–2546, https://doi.org/10.5194/nhess-23-2531-2023, https://doi.org/10.5194/nhess-23-2531-2023, 2023
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Meteotsunami are globally occurring water waves initiated by atmospheric disturbances. Previous research has suggested that in the UK, meteotsunami are a rare phenomenon and tend to occur in the summer months. This article presents a revised and updated catalogue of 98 meteotsunami that occurred between 1750 and 2022. Results also demonstrate a larger percentage of winter events and a geographical pattern highlighting the
hotspotregions that experience these events.
Melissa Wood, Ivan D. Haigh, Quan Quan Le, Hung Nghia Nguyen, Hoang Ba Tran, Stephen E. Darby, Robert Marsh, Nikolaos Skliris, Joël J.-M. Hirschi, Robert J. Nicholls, and Nadia Bloemendaal
Nat. Hazards Earth Syst. Sci., 23, 2475–2504, https://doi.org/10.5194/nhess-23-2475-2023, https://doi.org/10.5194/nhess-23-2475-2023, 2023
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We used a novel database of simulated tropical cyclone tracks to explore whether typhoon-induced storm surges present a future flood risk to low-lying coastal communities around the South China Sea. We found that future climate change is likely to change tropical cyclone behaviour to an extent that this increases the severity and frequency of storm surges to Vietnam, southern China, and Thailand. Consequently, coastal flood defences need to be reviewed for resilience against this future hazard.
Sang-Guk Yum, Moon-Soo Song, and Manik Das Adhikari
Nat. Hazards Earth Syst. Sci., 23, 2449–2474, https://doi.org/10.5194/nhess-23-2449-2023, https://doi.org/10.5194/nhess-23-2449-2023, 2023
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This study performed analysis on typhoon-induced coastal morphodynamics for the Mokpo coast. Wetland vegetation was severely impacted by Typhoon Soulik, with 87.35 % of shoreline transects experiencing seaward migration. This result highlights the fact that sediment resuspension controls the land alteration process over the typhoon period. The land accretion process dominated during the pre- to post-typhoon periods.
Olle Räty, Marko Laine, Ulpu Leijala, Jani Särkkä, and Milla M. Johansson
Nat. Hazards Earth Syst. Sci., 23, 2403–2418, https://doi.org/10.5194/nhess-23-2403-2023, https://doi.org/10.5194/nhess-23-2403-2023, 2023
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We studied annual maximum sea levels in the Finnish coastal region. Our aim was to better quantify the uncertainty in them compared to previous studies. Using four statistical models, we found out that hierarchical models, which shared information on sea-level extremes across Finnish tide gauges, had lower uncertainty in their results in comparison with tide-gauge-specific fits. These models also suggested that the shape of the distribution for extreme sea levels is similar on the Finnish coast.
Christian Ferrarin, Florian Pantillon, Silvio Davolio, Marco Bajo, Mario Marcello Miglietta, Elenio Avolio, Diego S. Carrió, Ioannis Pytharoulis, Claudio Sanchez, Platon Patlakas, Juan Jesús González-Alemán, and Emmanouil Flaounas
Nat. Hazards Earth Syst. Sci., 23, 2273–2287, https://doi.org/10.5194/nhess-23-2273-2023, https://doi.org/10.5194/nhess-23-2273-2023, 2023
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The combined use of meteorological and ocean models enabled the analysis of extreme sea conditions driven by Medicane Ianos, which hit the western coast of Greece on 18 September 2020, flooding and damaging the coast. The large spread associated with the ensemble highlighted the high model uncertainty in simulating such an extreme weather event. The different simulations have been used for outlining hazard scenarios that represent a fundamental component of the coastal risk assessment.
Charline Dalinghaus, Giovanni Coco, and Pablo Higuera
Nat. Hazards Earth Syst. Sci., 23, 2157–2169, https://doi.org/10.5194/nhess-23-2157-2023, https://doi.org/10.5194/nhess-23-2157-2023, 2023
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Wave setup is a critical component of coastal flooding. Consequently, understanding and being able to predict wave setup is vital to protect coastal resources and the population living near the shore. Here, we applied machine learning to improve the accuracy of present predictors of wave setup. The results show that the new predictors outperform existing formulas demonstrating the capability of machine learning models to provide a physically sound description of wave setup.
Ina Teutsch, Markus Brühl, Ralf Weisse, and Sander Wahls
Nat. Hazards Earth Syst. Sci., 23, 2053–2073, https://doi.org/10.5194/nhess-23-2053-2023, https://doi.org/10.5194/nhess-23-2053-2023, 2023
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Rogue waves exceed twice the significant wave height. They occur more often than expected in the shallow waters off Norderney. When applying a nonlinear Fourier transform for the Korteweg–de Vries equation to wave data from Norderney, we found differences in the soliton spectra of time series with and without rogue waves. A strongly outstanding soliton in the spectrum indicated an enhanced probability for rogue waves. We could attribute spectral solitons to the measured rogue waves.
Philipp Heinrich, Stefan Hagemann, Ralf Weisse, Corinna Schrum, Ute Daewel, and Lidia Gaslikova
Nat. Hazards Earth Syst. Sci., 23, 1967–1985, https://doi.org/10.5194/nhess-23-1967-2023, https://doi.org/10.5194/nhess-23-1967-2023, 2023
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High seawater levels co-occurring with high river discharges have the potential to cause destructive flooding. For the past decades, the number of such compound events was larger than expected by pure chance for most of the west-facing coasts in Europe. Additionally rivers with smaller catchments showed higher numbers. In most cases, such events were associated with a large-scale weather pattern characterized by westerly winds and strong rainfall.
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Short summary
In coastal regions, flooding can occur from combined tides, storms, river discharge, and waves. Effects of waves are commonly neglected when assessing flooding, although these may strongly contribute to extreme water levels. We find that waves combined with tides and river discharge at Breede Estuary, South Africa, increased flood extent and depth and caused earlier flooding than when waves were neglected. This highlights the need to consider all major flood drivers in future flood assessments.
In coastal regions, flooding can occur from combined tides, storms, river discharge, and waves....
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