Articles | Volume 28, issue 12
https://doi.org/10.5194/hess-28-2603-2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Special issue:
https://doi.org/10.5194/hess-28-2603-2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Opinion article
| 
19 Jun 2024
Opinion article |
| 19 Jun 2024
| 19 Jun 2024
HESS Opinions: The sword of Damocles of the impossible flood
Alberto Montanari
CORRESPONDING AUTHOR
Department of Civil, Chemical, Environmental and Materials Engineering, University of Bologna, Bologna, Italy
Bruno Merz
Section Hydrology, GFZ German Research Centre for Geosciences, Potsdam, Germany
Institute for Environmental Sciences and Geography, University Potsdam, Potsdam, Germany
Günter Blöschl
Institute of Hydraulic Engineering and Water Resources Management, Technical University Vienna, Vienna, Austria
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Alonso Pizarro, Demetris Koutsoyiannis, and Alberto Montanari
Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hess-2024-389, https://doi.org/10.5194/hess-2024-389, 2025
Revised manuscript accepted for HESS
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We introduce RUMI, a new metric to improve rainfall-runoff simulations. RUMI better captures the link between observed and simulated stream flows by considering uncertainty at a core computation step. Tested on 99 catchments and with the GR4J model, it outperforms traditional metrics by providing more reliable and consistent results. RUMI paves the way for more accurate hydrological predictions.
Rui Guo and Alberto Montanari
Hydrol. Earth Syst. Sci., 27, 2847–2863, https://doi.org/10.5194/hess-27-2847-2023, https://doi.org/10.5194/hess-27-2847-2023, 2023
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The present study refers to the region of Bologna, where the availability of a 209-year-long daily rainfall series allows us to make a unique assessment of global climate models' reliability and their predicted changes in rainfall and multiyear droughts. Our results suggest carefully considering the impact of uncertainty when designing climate change adaptation policies for droughts. Rigorous use and comprehensive interpretation of the available information are needed to avoid mismanagement.
Xiaoxiang Guan, Viet Dung Nguyen, Paul Voit, Bruno Merz, Maik Heistermann, and Sergiy Vorogushyn
Nat. Hazards Earth Syst. Sci., 25, 3075–3086, https://doi.org/10.5194/nhess-25-3075-2025, https://doi.org/10.5194/nhess-25-3075-2025, 2025
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We evaluated a multi-site stochastic regional weather generator (nsRWG) for its ability to capture the cross-scale extremity of heavy-precipitation events (HPEs) in Germany. We generated 100 realizations of 72 years of daily synthetic precipitation data. The performance was assessed using WEI and xWEI indices, which measure event extremity across spatiotemporal scales. The results show that nsRWG simulates the extremity patterns of HPEs well, although it overestimates short-duration small-extent events.
Adrian Flores Orozco, Jakob Gallistl, Benjamin Gilfedder, Timea Katona, Sven Frei, Peter Strauss, and Gunter Blöschl
EGUsphere, https://doi.org/10.5194/egusphere-2025-4015, https://doi.org/10.5194/egusphere-2025-4015, 2025
This preprint is open for discussion and under review for Biogeosciences (BG).
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Understanding the role of soil in the storage of organic carbon is critical for a large number of environmental processes. Current practices rely on the drilling and analysis of samples, which is expensive, time consuming and destructive. Here we present a technique able to map soil organic carbon measuring the electrical properties of the subsurface without the necessity of drilling. Our results could permit to advance soil management strategies to enhance carbon sequestration and storage.
Hatice Türk, Christine Stumpp, Markus Hrachowitz, Karsten Schulz, Peter Strauss, Günter Blöschl, and Michael Stockinger
Hydrol. Earth Syst. Sci., 29, 3935–3956, https://doi.org/10.5194/hess-29-3935-2025, https://doi.org/10.5194/hess-29-3935-2025, 2025
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Using advances in transit time estimation and tracer data, we tested if fast-flow transit times are controlled solely by soil moisture or if they are also controlled by precipitation intensity. We used soil-moisture-dependent and precipitation-intensity-conditional transfer functions. We showed that a significant portion of event water bypasses the soil matrix through fast flow paths (overland flow, tile drains, preferential-flow paths) in dry soil conditions for both low- and high-intensity precipitation.
Hatice Türk, Christine Stumpp, Markus Hrachowitz, Peter Strauss, Günter Blöschl, and Michael Stockinger
EGUsphere, https://doi.org/10.5194/egusphere-2025-2597, https://doi.org/10.5194/egusphere-2025-2597, 2025
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This study shows that stream flow isotope data (δ2H) were inadequate for distinguishing preferential groundwater flow. Large passive groundwater storage dampened δ2H variations, obscuring signals of fast groundwater flow and complicating the estimation of older water fractions in the streams. Further, weekly-resolution δ2H sampling yielded deceptively high model performance, highlighting the need for complementary and groundwater-level data to improve catchment-scale transit-time estimates.
Sergiy Vorogushyn, Li Han, Heiko Apel, Viet Dung Nguyen, Björn Guse, Xiaoxiang Guan, Oldrich Rakovec, Husain Najafi, Luis Samaniego, and Bruno Merz
Nat. Hazards Earth Syst. Sci., 25, 2007–2029, https://doi.org/10.5194/nhess-25-2007-2025, https://doi.org/10.5194/nhess-25-2007-2025, 2025
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The July 2021 flood in central Europe was one of the deadliest floods in Europe in the recent decades and the most expensive flood in Germany. In this paper, we show that the hydrological impact of this event in the Ahr valley could have been even worse if the rainfall footprint trajectory had been only slightly different. The presented methodology of spatial counterfactuals generates plausible unprecedented events and helps to better prepare for future extreme floods.
Christopher Thoma, Borbala Szeles, Miriam Bertola, Elmar Schmaltz, Carmen Krammer, Peter Strauss, and Günter Blöschl
EGUsphere, https://doi.org/10.5194/egusphere-2025-2541, https://doi.org/10.5194/egusphere-2025-2541, 2025
This preprint is open for discussion and under review for Hydrology and Earth System Sciences (HESS).
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We studied how farming practices affect soil and sediment movement in a small Austrian catchment. By monitoring water and sediment during 55 rain events, we found that erosion control worked well in flat fields near the stream, but not in steep or distant fields. Our results show that reducing soil loss requires strategies that consider slope, distance to streams, and how water flows through the landscape.
Xiaoxiang Guan, Baoying Shan, Viet Dung Nguyen, and Bruno Merz
EGUsphere, https://doi.org/10.5194/egusphere-2025-1509, https://doi.org/10.5194/egusphere-2025-1509, 2025
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Understanding and predicting extreme floods is crucial for reducing disaster risks, yet existing models struggle with unprecedented events. We tested multiple modeling approaches across 400+ river catchments in Central Europe and found that deep learning models outperform traditional methods but still underestimate extreme floods. Our findings suggest that combining data-driven models with physical knowledge can improve flood predictions, helping communities better prepare for future extremes.
Paolo Nasta, Günter Blöschl, Heye R. Bogena, Steffen Zacharias, Roland Baatz, Gabriëlle De Lannoy, Karsten H. Jensen, Salvatore Manfreda, Laurent Pfister, Ana M. Tarquis, Ilja van Meerveld, Marc Voltz, Yijian Zeng, William Kustas, Xin Li, Harry Vereecken, and Nunzio Romano
Hydrol. Earth Syst. Sci., 29, 465–483, https://doi.org/10.5194/hess-29-465-2025, https://doi.org/10.5194/hess-29-465-2025, 2025
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The Unsolved Problems in Hydrology (UPH) initiative has emphasized the need to establish networks of multi-decadal hydrological observatories to tackle catchment-scale challenges on a global scale. This opinion paper provocatively discusses two endmembers of possible future hydrological observatory (HO) networks for a given hypothesized community budget: a comprehensive set of moderately instrumented observatories or, alternatively, a small number of highly instrumented supersites.
Elena Macdonald, Bruno Merz, Viet Dung Nguyen, and Sergiy Vorogushyn
Hydrol. Earth Syst. Sci., 29, 447–463, https://doi.org/10.5194/hess-29-447-2025, https://doi.org/10.5194/hess-29-447-2025, 2025
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Flood peak distributions indicate how likely the occurrence of an extreme flood is at a certain river. If the distribution has a so-called heavy tail, extreme floods are more likely than might be anticipated. We find heavier tails in small catchments compared to large catchments, and spatially variable rainfall leads to a lower occurrence probability of extreme floods. Spatially variable runoff does not show effects. The results can improve estimations of probabilities of extreme floods.
Alonso Pizarro, Demetris Koutsoyiannis, and Alberto Montanari
Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hess-2024-389, https://doi.org/10.5194/hess-2024-389, 2025
Revised manuscript accepted for HESS
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We introduce RUMI, a new metric to improve rainfall-runoff simulations. RUMI better captures the link between observed and simulated stream flows by considering uncertainty at a core computation step. Tested on 99 catchments and with the GR4J model, it outperforms traditional metrics by providing more reliable and consistent results. RUMI paves the way for more accurate hydrological predictions.
Bruno Merz, Günter Blöschl, Robert Jüpner, Heidi Kreibich, Kai Schröter, and Sergiy Vorogushyn
Nat. Hazards Earth Syst. Sci., 24, 4015–4030, https://doi.org/10.5194/nhess-24-4015-2024, https://doi.org/10.5194/nhess-24-4015-2024, 2024
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Flood risk assessments help us decide how to reduce the risk of flooding. Since these assessments are based on probabilities, it is hard to check their accuracy by comparing them to past data. We suggest a new way to validate these assessments, making sure they are practical for real-life decisions. This approach looks at both the technical details and the real-world situations where decisions are made. We demonstrate its practicality by applying it to flood emergency planning.
Viet Dung Nguyen, Sergiy Vorogushyn, Katrin Nissen, Lukas Brunner, and Bruno Merz
Adv. Stat. Clim. Meteorol. Oceanogr., 10, 195–216, https://doi.org/10.5194/ascmo-10-195-2024, https://doi.org/10.5194/ascmo-10-195-2024, 2024
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We present a novel stochastic weather generator conditioned on circulation patterns and regional temperature, accounting for dynamic and thermodynamic atmospheric changes. We extensively evaluate the model for the central European region. It statistically downscales precipitation for future periods, generating long, spatially and temporally consistent series. Results suggest an increase in extreme precipitation over the region, offering key benefits for hydrological impact studies.
Viet Dung Nguyen, Jeroen Aerts, Max Tesselaar, Wouter Botzen, Heidi Kreibich, Lorenzo Alfieri, and Bruno Merz
Nat. Hazards Earth Syst. Sci., 24, 2923–2937, https://doi.org/10.5194/nhess-24-2923-2024, https://doi.org/10.5194/nhess-24-2923-2024, 2024
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Our study explored how seasonal flood forecasts could enhance insurance premium accuracy. Insurers traditionally rely on historical data, yet climate fluctuations influence flood risk. We employed a method that predicts seasonal floods to adjust premiums accordingly. Our findings showed significant year-to-year variations in flood risk and premiums, underscoring the importance of adaptability. Despite limitations, this research aids insurers in preparing for evolving risks.
Günter Blöschl, Andreas Buttinger-Kreuzhuber, Daniel Cornel, Julia Eisl, Michael Hofer, Markus Hollaus, Zsolt Horváth, Jürgen Komma, Artem Konev, Juraj Parajka, Norbert Pfeifer, Andreas Reithofer, José Salinas, Peter Valent, Roman Výleta, Jürgen Waser, Michael H. Wimmer, and Heinz Stiefelmeyer
Nat. Hazards Earth Syst. Sci., 24, 2071–2091, https://doi.org/10.5194/nhess-24-2071-2024, https://doi.org/10.5194/nhess-24-2071-2024, 2024
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A methodology of regional flood hazard mapping is proposed, based on data in Austria, which combines automatic methods with manual interventions to maximise efficiency and to obtain estimation accuracy similar to that of local studies. Flood discharge records from 781 stations are used to estimate flood hazard patterns of a given return period at a resolution of 2 m over a total stream length of 38 000 km. The hazard maps are used for civil protection, risk awareness and insurance purposes.
Seth Bryant, Heidi Kreibich, and Bruno Merz
Proc. IAHS, 386, 181–187, https://doi.org/10.5194/piahs-386-181-2024, https://doi.org/10.5194/piahs-386-181-2024, 2024
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Our study found that simplifying data in flood risk models can introduce errors. We tested 344 damage functions and found errors up to 40 % of the total asset value. This means large-scale flood risk assessments may have significant errors due to the modelling approach. Our research highlights the need for more attention to data aggregation in flood risk models.
Elena Macdonald, Bruno Merz, Björn Guse, Viet Dung Nguyen, Xiaoxiang Guan, and Sergiy Vorogushyn
Hydrol. Earth Syst. Sci., 28, 833–850, https://doi.org/10.5194/hess-28-833-2024, https://doi.org/10.5194/hess-28-833-2024, 2024
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In some rivers, the occurrence of extreme flood events is more likely than in other rivers – they have heavy-tailed distributions. We find that threshold processes in the runoff generation lead to such a relatively high occurrence probability of extremes. Further, we find that beyond a certain return period, i.e. for rare events, rainfall is often the dominant control compared to runoff generation. Our results can help to improve the estimation of the occurrence probability of extreme floods.
Seth Bryant, Guy Schumann, Heiko Apel, Heidi Kreibich, and Bruno Merz
Hydrol. Earth Syst. Sci., 28, 575–588, https://doi.org/10.5194/hess-28-575-2024, https://doi.org/10.5194/hess-28-575-2024, 2024
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A new algorithm has been developed to quickly produce high-resolution flood maps. It is faster and more accurate than current methods and is available as open-source scripts. This can help communities better prepare for and mitigate flood damages without expensive modelling.
Rui Guo and Alberto Montanari
Hydrol. Earth Syst. Sci., 27, 2847–2863, https://doi.org/10.5194/hess-27-2847-2023, https://doi.org/10.5194/hess-27-2847-2023, 2023
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The present study refers to the region of Bologna, where the availability of a 209-year-long daily rainfall series allows us to make a unique assessment of global climate models' reliability and their predicted changes in rainfall and multiyear droughts. Our results suggest carefully considering the impact of uncertainty when designing climate change adaptation policies for droughts. Rigorous use and comprehensive interpretation of the available information are needed to avoid mismanagement.
Mohammad Ghoreishi, Amin Elshorbagy, Saman Razavi, Günter Blöschl, Murugesu Sivapalan, and Ahmed Abdelkader
Hydrol. Earth Syst. Sci., 27, 1201–1219, https://doi.org/10.5194/hess-27-1201-2023, https://doi.org/10.5194/hess-27-1201-2023, 2023
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The study proposes a quantitative model of the willingness to cooperate in the Eastern Nile River basin. Our results suggest that the 2008 food crisis may account for Sudan recovering its willingness to cooperate with Ethiopia. Long-term lack of trust among the riparian countries may have reduced basin-wide cooperation. The model can be used to explore the effects of changes in future dam operations and other management decisions on the emergence of basin cooperation.
Enrico Bonanno, Günter Blöschl, and Julian Klaus
Hydrol. Earth Syst. Sci., 26, 6003–6028, https://doi.org/10.5194/hess-26-6003-2022, https://doi.org/10.5194/hess-26-6003-2022, 2022
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There is an unclear understanding of which processes regulate the transport of water, solutes, and pollutants in streams. This is crucial since these processes control water quality in river networks. Compared to other approaches, we obtained clearer insights into the processes controlling solute transport in the investigated reach. This work highlights the risks of using uncertain results for interpreting the processes controlling water movement in streams.
Günter Blöschl
Hydrol. Earth Syst. Sci., 26, 5015–5033, https://doi.org/10.5194/hess-26-5015-2022, https://doi.org/10.5194/hess-26-5015-2022, 2022
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There is serious concern that river floods are increasing. Starting from explanations discussed in public, the article addresses three hypotheses: land-use change, hydraulic structures, and climate change increase floods. This review finds that all three changes have the potential to not only increase floods, but also to reduce them. It is crucial to consider all three factors of change in flood risk management and communicate them to the general public in a nuanced way.
Heiko Apel, Sergiy Vorogushyn, and Bruno Merz
Nat. Hazards Earth Syst. Sci., 22, 3005–3014, https://doi.org/10.5194/nhess-22-3005-2022, https://doi.org/10.5194/nhess-22-3005-2022, 2022
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The paper presents a fast 2D hydraulic simulation model for flood propagation that enables operational forecasts of spatially distributed inundation depths, flood extent, flow velocities, and other flood impacts. The detailed spatial forecast of floods and flood impacts is a large step forward from the currently operational forecasts of discharges at selected gauges, thus enabling a more targeted flood management and early warning.
Shengping Wang, Borbala Szeles, Carmen Krammer, Elmar Schmaltz, Kepeng Song, Yifan Li, Zhiqiang Zhang, Günter Blöschl, and Peter Strauss
Hydrol. Earth Syst. Sci., 26, 3021–3036, https://doi.org/10.5194/hess-26-3021-2022, https://doi.org/10.5194/hess-26-3021-2022, 2022
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This study explored the quantitative contribution of agricultural intensification and climate change to the sediment load of a small agricultural watershed. Rather than a change in climatic conditions, changes in the land structure notably altered sediment concentrations under high-flow conditions, thereby contributing most to the increase in annual sediment loads. More consideration of land structure improvement is required when combating the transfer of soil from land to water.
Günter Blöschl
Hydrol. Earth Syst. Sci., 26, 2469–2480, https://doi.org/10.5194/hess-26-2469-2022, https://doi.org/10.5194/hess-26-2469-2022, 2022
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Sound understanding of how floods come about allows for the development of more reliable flood management tools that assist in mitigating their negative impacts. This article reviews river flood generation processes and flow paths across space scales, starting from water movement in the soil pores and moving up to hillslopes, catchments, regions and entire continents. To assist model development, there is a need to learn from observed patterns of flood generation processes at all spatial scales.
Rui Tong, Juraj Parajka, Borbála Széles, Isabella Greimeister-Pfeil, Mariette Vreugdenhil, Jürgen Komma, Peter Valent, and Günter Blöschl
Hydrol. Earth Syst. Sci., 26, 1779–1799, https://doi.org/10.5194/hess-26-1779-2022, https://doi.org/10.5194/hess-26-1779-2022, 2022
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The role and impact of using additional data (other than runoff) for the prediction of daily hydrographs in ungauged basins are not well understood. In this study, we assessed the model performance in terms of runoff, soil moisture, and snow cover predictions with the existing regionalization approaches. Results show that the best transfer methods are the similarity and the kriging approaches. The performance of the transfer methods differs between lowland and alpine catchments.
Wouter Dorigo, Irene Himmelbauer, Daniel Aberer, Lukas Schremmer, Ivana Petrakovic, Luca Zappa, Wolfgang Preimesberger, Angelika Xaver, Frank Annor, Jonas Ardö, Dennis Baldocchi, Marco Bitelli, Günter Blöschl, Heye Bogena, Luca Brocca, Jean-Christophe Calvet, J. Julio Camarero, Giorgio Capello, Minha Choi, Michael C. Cosh, Nick van de Giesen, Istvan Hajdu, Jaakko Ikonen, Karsten H. Jensen, Kasturi Devi Kanniah, Ileen de Kat, Gottfried Kirchengast, Pankaj Kumar Rai, Jenni Kyrouac, Kristine Larson, Suxia Liu, Alexander Loew, Mahta Moghaddam, José Martínez Fernández, Cristian Mattar Bader, Renato Morbidelli, Jan P. Musial, Elise Osenga, Michael A. Palecki, Thierry Pellarin, George P. Petropoulos, Isabella Pfeil, Jarrett Powers, Alan Robock, Christoph Rüdiger, Udo Rummel, Michael Strobel, Zhongbo Su, Ryan Sullivan, Torbern Tagesson, Andrej Varlagin, Mariette Vreugdenhil, Jeffrey Walker, Jun Wen, Fred Wenger, Jean Pierre Wigneron, Mel Woods, Kun Yang, Yijian Zeng, Xiang Zhang, Marek Zreda, Stephan Dietrich, Alexander Gruber, Peter van Oevelen, Wolfgang Wagner, Klaus Scipal, Matthias Drusch, and Roberto Sabia
Hydrol. Earth Syst. Sci., 25, 5749–5804, https://doi.org/10.5194/hess-25-5749-2021, https://doi.org/10.5194/hess-25-5749-2021, 2021
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The International Soil Moisture Network (ISMN) is a community-based open-access data portal for soil water measurements taken at the ground and is accessible at https://ismn.earth. Over 1000 scientific publications and thousands of users have made use of the ISMN. The scope of this paper is to inform readers about the data and functionality of the ISMN and to provide a review of the scientific progress facilitated through the ISMN with the scope to shape future research and operations.
David Lun, Alberto Viglione, Miriam Bertola, Jürgen Komma, Juraj Parajka, Peter Valent, and Günter Blöschl
Hydrol. Earth Syst. Sci., 25, 5535–5560, https://doi.org/10.5194/hess-25-5535-2021, https://doi.org/10.5194/hess-25-5535-2021, 2021
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We investigate statistical properties of observed flood series on a European scale. There are pronounced regional patterns, for instance: regions with strong Atlantic influence show less year-to-year variability in the magnitude of observed floods when compared with more arid regions of Europe. The hydrological controls on the patterns are quantified and discussed. On the European scale, climate seems to be the dominant driver for the observed patterns.
Concetta Di Mauro, Renaud Hostache, Patrick Matgen, Ramona Pelich, Marco Chini, Peter Jan van Leeuwen, Nancy K. Nichols, and Günter Blöschl
Hydrol. Earth Syst. Sci., 25, 4081–4097, https://doi.org/10.5194/hess-25-4081-2021, https://doi.org/10.5194/hess-25-4081-2021, 2021
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This study evaluates how the sequential assimilation of flood extent derived from synthetic aperture radar data can help improve flood forecasting. In particular, we carried out twin experiments based on a synthetically generated dataset with controlled uncertainty. Our empirical results demonstrate the efficiency of the proposed data assimilation framework, as forecasting errors are substantially reduced as a result of the assimilation.
Abhirup Banerjee, Bedartha Goswami, Yoshito Hirata, Deniz Eroglu, Bruno Merz, Jürgen Kurths, and Norbert Marwan
Nonlin. Processes Geophys., 28, 213–229, https://doi.org/10.5194/npg-28-213-2021, https://doi.org/10.5194/npg-28-213-2021, 2021
Lovrenc Pavlin, Borbála Széles, Peter Strauss, Alfred Paul Blaschke, and Günter Blöschl
Hydrol. Earth Syst. Sci., 25, 2327–2352, https://doi.org/10.5194/hess-25-2327-2021, https://doi.org/10.5194/hess-25-2327-2021, 2021
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We compared the dynamics of streamflow, groundwater and soil moisture to investigate how different parts of an agricultural catchment in Lower Austria are connected. Groundwater is best connected around the stream and worse uphill, where groundwater is deeper. Soil moisture connectivity increases with increasing catchment wetness but is not influenced by spatial position in the catchment. Groundwater is more connected to the stream on the seasonal scale compared to the event scale.
Rui Tong, Juraj Parajka, Andreas Salentinig, Isabella Pfeil, Jürgen Komma, Borbála Széles, Martin Kubáň, Peter Valent, Mariette Vreugdenhil, Wolfgang Wagner, and Günter Blöschl
Hydrol. Earth Syst. Sci., 25, 1389–1410, https://doi.org/10.5194/hess-25-1389-2021, https://doi.org/10.5194/hess-25-1389-2021, 2021
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We used a new and experimental version of the Advanced Scatterometer (ASCAT) soil water index data set and Moderate Resolution Imaging Spectroradiometer (MODIS) C6 snow cover products for multiple objective calibrations of the TUWmodel in 213 catchments of Austria. Combined calibration to runoff, satellite soil moisture, and snow cover improves runoff (40 % catchments), soil moisture (80 % catchments), and snow (~ 100 % catchments) simulation compared to traditional calibration to runoff only.
Miriam Bertola, Alberto Viglione, Sergiy Vorogushyn, David Lun, Bruno Merz, and Günter Blöschl
Hydrol. Earth Syst. Sci., 25, 1347–1364, https://doi.org/10.5194/hess-25-1347-2021, https://doi.org/10.5194/hess-25-1347-2021, 2021
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We estimate the contribution of extreme precipitation, antecedent soil moisture and snowmelt to changes in small and large floods across Europe.
In northwestern and eastern Europe, changes in small and large floods are driven mainly by one single driver (i.e. extreme precipitation and snowmelt, respectively). In southern Europe both antecedent soil moisture and extreme precipitation significantly contribute to flood changes, and their relative importance depends on flood magnitude.
Gustavo Andrei Speckhann, Heidi Kreibich, and Bruno Merz
Earth Syst. Sci. Data, 13, 731–740, https://doi.org/10.5194/essd-13-731-2021, https://doi.org/10.5194/essd-13-731-2021, 2021
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Dams are an important element of water resources management. Data about dams are crucial for practitioners, scientists, and policymakers. We present the most comprehensive open-access dam inventory for Germany to date. The inventory combines multiple sources of information. It comprises 530 dams with information on name, location, river, start year of construction and operation, crest length, dam height, lake area, lake volume, purpose, dam structure, and building characteristics.
Cited articles
Aerts, J. C., Botzen, W. J., Clarke, K. C., Cutter, S. L., Hall, J. W., Merz, B., Michel-Kerjan, E., Mysiak, J., Surminski, S., and Kunreuther, H.: Integrating human behaviour dynamics into flood disaster risk assessment, Nat. Clim. Change, 8, 193–199, 2018.
Albano, C. M., Dettinger, M. D., McCarthy, M. I., Schaller, K. D., Welborn, T. L., and Cox, D. A.: Application of an extreme winter storm scenario to identify vulnerabilities, mitigation options, and science needs in the Sierra Nevada mountains, USA, Nat. Hazards, 80, 879–900, https://doi.org/10.1007/s11069-015-2003-4, 2016.
Alexander, M.: Aging, bioavailability, and overestimation of risk from environmental pollutants, Environ. Sci. Technol., 34, 4259–4265, 2000.
Alkema, D. and Middelkoop, H.: The Influence of Floodplain Compartmentalization on Flood Risk within the Rhine-Meuse Delta, Nat. Hazards, 36, 125–145, 2005.
Apel, H., Vorogushyn, S., and Merz, B.: Brief communication: Impact forecasting could substantially improve the emergency management of deadly floods: case study July 2021 floods in Germany, Nat. Hazards Earth Syst. Sci., 22, 3005–3014, https://doi.org/10.5194/nhess-22-3005-2022, 2022.
Blöschl, G.: Three hypotheses on changing river flood hazards, Hydrol. Earth Syst. Sci., 26, 5015–5033, https://doi.org/10.5194/hess-26-5015-2022, 2022.
Blöschl, G., Viglione, A., and Montanari, A.: Emerging approaches to hydrological risk management in a changing world, in: Climate Vulnerability: Understanding and Addressing Threats to Essential Resources, Elsevier Inc., Academic Press, 3–10, ISBN 9780123847041, 2013.
Blöschl, G., Hall, J., Viglione, A., Perdigão, R. A. P., Parajka, J., Merz, B., Lun, D., Arheimer, B., Aronica, G. T., Bilibashi, A., Boháč, M., Bonacci, O., Borga, M., Čanjevac, I., Castellarin, A., Chirico, G. B., Claps, P., Frolova, N., Ganora, D., Gorbachova, L., Gül, A., Hannaford, J., Harrigan, S., Kireeva, M., Kiss, A., Kjeldsen, T. R., Kohnová, S., Koskela, J. J., Ledvinka, O., Macdonald, N., Mavrova-Guirguinova, M., Mediero, L., Merz, R., Molnar, P., Montanari, A., Murphy, C., Osuch, M., Ovcharuk, V., Radevski, I., Salinas, J. L., Sauquet, E., Šraj, M., Szolgay, J., Volpi, E., Wilson, D., Zaimi, K., and Živković, N.: Changing climate both increases and decreases European river floods, Nature, 573, 108–111, https://doi.org/10.1038/s41586-019-1495-6, 2019.
Brunner, M. I. and Slater, L. J.: Extreme floods in Europe: going beyond observations using reforecast ensemble pooling, Hydrol. Earth Syst. Sci., 26, 469–482, https://doi.org/10.5194/hess-26-469-2022, 2022.
Commission of the European Communities: Directive 2007/60/EC of the European Parliament and of the Council of 23 October 2007 on the assessment and management of flood risks, Official Journal of the European Union, L 288, 27–34, https://eur-lex.europa.eu/legal-content/EN/ALL/?uri=celex:32007L0060 (last access: 28 May 2024) 2007.
CRED: The psychology of climate change communication, Center for Research on Environmental Decisions at Columbia University, http://cred.columbia.edu/guide/ (last access: 28 May 2024), 2009.
D'Angelo, C., Fiori, A., and Volpi, E.: Structural, dynamic and anthropic conditions that trigger the emergence of the levee effect: insight from a simplified risk-based framework, Hydrolog. Sci. J., 65, 914–927, 2020.
Delle Rose, M.: Decision-making errors and socio-political disputes over the Vajont dam disaster, Disaster Adv., 5, 144–152, 2012.
Di Baldassarre, G., Castellarin, A., and Brath, A.: Analysis of the effects of levee heightening on flood propagation: example of the River Po, Italy, Hydrolog. Sci. J., 54, 1007–1017, 2009.
DWA: Estimation of flood probabilities [Ermittlung von Hochwasserwahrscheinlichkeiten], Guideline DWA-M 552, German Association for Water, Wastewater and Waste (DWA) Hennef, Germany, ISBN 978-3-942964-25-8, 2012 (in German).
European Commission: Adapting to climate change: towards a European framework for action, White Paper, Brussels, COM (2009), 147, 16 pp., https://eur-lex.europa.eu/legal-content/EN/ALL/?uri=CELEX%3A52009DC0147 (last access: 28 May 2024), 2009.
Fiori, A., Mancini, C. P., Annis, A., Lollai, S., Volpi, E., Nardi, F., and Grimaldi, S.: The role of residual risk on flood damage assessment: A continuous hydrologic-hydraulic modelling approach for the historical city of Rome, Italy, J. Hydrol., 49, 101506, https://doi.org/10.1016/j.ejrh.2023.101506, 2023.
FONDEN: Mexico's Natural Disaster Fund – A Review, The International Bank for Reconstruction and Development/The World Bank, Washington DC, 74 pp., 2012.
GACGC (German Advisory Council on Global Change): World in Transition: Strategies for managing global environmental risks, Annual report of the German Advisory Council on Global Change, Springer, Berlin, Heidelberg, ISBN 3-9806309-3-5, 2000.
Galloway, G., Seminara, G., Blöschl, G., Garcia, M., Montanari, A., and Solari L.: Reducing the flood risk of art cities: the case of Florence, J. Hydraul. Eng., 146, 02520001, https://doi.org/10.1061/(ASCE)HY.1943-7900.0001741, 2020.
Haer, T., Botzen, W. J. W., and Aerts, J. C. J. H.: Advancing disaster policies by integrating dynamic adaptive behaviour in risk assessments using an agent-based modelling approach, Environ. Res. Lett., 14, 044022, https://doi.org/10.1088/1748-9326/ab0770, 2019.
Hammitt, J. K. and Shlyakhter, A. I.: The expected value of information and the probability of surprise, Risk Anal., 19, 135–152, 1999.
Hollins, L. X., Eisenberg, D. A., and Seager, T. P.: Risk and resilience at the Oroville Dam, Infrastructures, 3, 49, https://doi.org/10.3390/infrastructures3040049, 2018.
Kasperson, R. E., Renn, O., Slovic, P., Brown, H. S., Emel, J., Goble, R., Kasperson, J. X., and Ratick, S.: The Social Amplification of Risk: A Conceptual Framework, Risk Anal., 8, 177–187, 1988.
Kelder, T., Müller, M., Slater, L. J., Marjoribanks, T. I., Wilby, R. L., Prudhomme, C., Bohlinger, P., Ferranti, L., and Nipen, T.: Using UNSEEN trends to detect decadal changes in 100-year precipitation extremes, Clim. Atmos. Sci., 3, 47, https://doi.org/10.1038/s41612-020-00149-4, 2020.
Kellert, S. R.: The value of life: biological diversity and human society, Island press, ISBN 9781559633185, 1996.
Kemter, M., Fischer, M., Luna, L. V., Schönfeldt, E., Vogel, J., Banerjee, A., Korup, O., and Thonicke, K.: Cascading Hazards in the Aftermath of Australia's 2019/2020 Black Summer Wildfires, Earth's Future, 9, e2020EF001884, https://doi.org/10.1029/2020EF001884, 2021.
Kind, J., Wouter Botzen, W. J. W. and Aerts, J. C. J. H.: Accounting for risk aversion, income distribution and social welfare in cost–benefit analysis for flood risk management, WIREs Clim. Change, 8, e446, https://doi.org/10.1002/wcc.446, 2017.
Klijn, F., Kreibich, H., De Moel, H., and Penning-Rowsell, E.: Adaptive flood risk management planning based on a comprehensive flood risk conceptualisation, Mitig. Adapt. Strat. Gl., 20, 845–864, 2015.
Knittel, N., Tesselaar, M., Wouter Botzen, W. J., Bachner, G., and Tiggeloven, T.: Who bears the indirect costs of flood risk? An economy-wide assessment of different insurance systems in Europe under climate change, Econ. Syst. Res., 36, 1–30, https://doi.org/10.1080/09535314.2023.2272211, 2023.
Koks, E. E., Jongman, B., Husby, T. G., and Botzen, W. J. W.: Combining hazard, exposure and social vulnerability to provide lessons for flood risk management, Environ. Sci. Policy, 47, 42–52, 2015.
Kreibich, H., Hudson, P., and Merz, B.: Knowing What to Do Substantially Improves the Effectiveness of Flood Early Warning, B. Am. Meteor. Soc., 102, E1450–E1463, https://doi.org/10.1175/bams-d-20-0262.1, 2021.
Kuchyňa, P.: Problems associated with value of life, Proc. Econ. Financ., 25, 378–385, 2015.
Kuhlicke, C., Seebauer, S., Hudson, P., Begg, C., Bubeck, P., Dittmer, C., Grothmann, T., Heidenreich, A., Kreibich, H., Lorenz, D. F., Masson, T., Reiter, J., Thaler, T., Thieken, A. H., and Bamberg, S.: The behavioral turn in flood risk management, its assumptions and potential implications, WIREs Water, 7, e1418, https://doi.org/10.1002/wat2.1418, 2020.
Landtag RLP: https://www.landtag.rlp.de/de/parlament/ausschuesse-und-gremien/fachausschuesse/untersuchungsausschuss-181-flutkatastrophe/ (last access: 19 February 2023), 2023.
Merz, R. and Blöschl, G.: Flood frequency hydrology: 1. Temporal, spatial, and causal expansion of information, Water Resour. Res., 44, W08432, https://doi.org/10.1029/2007WR006744, 2008a.
Merz R. and Blöschl G.: Flood frequency hydrology: 2. Combining data evidence, Water Resour. Res., 44, W08433, https://doi.org/10.1029/2007WR006745, 2008b.
Merz, B., Elmer, F., and Thieken, A. H.: Significance of “high probability/low damage” versus “low probability/high damage” flood events, Nat. Hazards Earth Syst. Sci., 9, 1033–1046, https://doi.org/10.5194/nhess-9-1033-2009, 2009.
Merz, B., Vorogushyn, S., Lall, U., Viglione, A., and Blöschl, G.: Charting unknown waters – On the role of surprise in flood risk assessment and management, Water Resour. Res., 51, 6399–6416, 2015.
Merz, B., Basso, S., Fischer, S., Lun, D., Blöschl, G., Merz, R., Guse, B., Viglione, A., Vorogushyn, S., Macdonald, E., and Wietzke, L.: Understanding heavy tails of flood peak distributions, Water Resour. Res., 58, e2021WR030506, https://doi.org/10.1029/2021WR030506, 2022.
Mohr, S., Ehret, U., Kunz, M., Ludwig, P., Caldas-Alvarez, A., Daniell, J. E., Ehmele, F., Feldmann, H., Franca, M. J., Gattke, C., Hundhausen, M., Knippertz, P., Küpfer, K., Mühr, B., Pinto, J. G., Quinting, J., Schäfer, A. M., Scheibel, M., Seidel, F., and Wisotzky, C.: A multi-disciplinary analysis of the exceptional flood event of July 2021 in central Europe – Part 1: Event description and analysis, Nat. Hazards Earth Syst. Sci., 23, 525–551, https://doi.org/10.5194/nhess-23-525-2023, 2023.
Montanari, A., Rosso, R., and Taqqu, M. S.: Fractionally differenced ARIMA models applied to hydrologic time series: Identification, estimation, and simulation, Water Resour. Res., 33, 1035–1044, 1997.
Munich Re: http://www.munichre.com/en/risks/natural-disasters-losses-are-trending-upwards/floods-and-flash-floods-underestimated-natural-hazards.html (last access: 19 February 2023), 2022.
Nguyen, H. D., Dang, D. K., Nguyen, N. Y., Pham Van, C., Van Nguyen, T. T., Nguyen, Q. H., Nguyen, X. L., Pham, L. T., Pham, V. T., and Bui, Q. T.: Integration of machine learning and hydrodynamic modeling to solve the extrapolation problem in flood depth estimation, J. Water Clim. Change, 15, 284–304, 2024.
Oost, J. and Hoekstra, A. Y.: Flood damage reduction by compartmentalization of a dike ring: comparing the effectiveness of three strategies, J. Flood Risk Manage., 2, 315–321, https://doi.org/10.1111/j.1753-318X.2009.01050.x, 2009.
ÖWAV: Rainfall-runoff modelling [Niederschlag-Abfluss-Modellierung], Guideline 220 Austrian Water and Waste Management Association (ÖWAV), Vienna, Austria, https://www.oewav.at/Publikationen?current=372330&mode=form (last access: 3 September 2023), 2019 (in German).
Papalexiou, S. M., Serinaldi, F., and Porcu, E.: Advancing space-time simulation of random fields: From storms to cyclones and beyond, Water Resour. Res., 57, e2020WR029466, https://doi.org/10.1029/2020WR029466, 2021.
Paté-Cornell, E.: On “Black Swans” and “Perfect Storms”: Risk Analysis and Management When Statistics Are Not Enough, Risk Anal., 32, 1823–1833, https://doi.org/10.1111/j.1539-6924.2011.01787.x, 2012.
Porter, K., Wein, A., Alpers, C. N., Baez, A., Barnard, P. L., Carter, J., Corsi, A., Costner, J., Cox, D., Das, T., and Dettinger, M.: Overview of the ARkStorm scenario (No. 2010-1312), US Geological Survey, https://doi.org/10.3133/ofr20101312, 2011.
Roggenkamp, T. and Herget, J.: Reconstructing peak discharges of historic floods in the River Ahr, Germany, Erdkunde, 68, 49–59, 2014.
Rogger, M., Viglione, A., Derx, J., and Blöschl, G.: Quantifying effects of catchments storage thresholds on step changes in the flood frequency curve, Water Resour. Res., 49, 6946–6958, https://doi.org/10.1002/wrcr.20553, 2013.
Sivapalan, M. and Blöschl, G.,: Time scale interactions and the coevolution of humans and water, Water Resources Research, 51, 6988–7022, https://doi.org/10.1002/2015WR017896, 2015.
Sivapalan, M., Savenije, H. H., and Blöschl, G.: Socio-hydrology: A new science of people and water, Hydrol. Process., 26, 1270–1276, 2012.
Sofia, G., Roder, G., Dalla Fontana, G., and Tarolli, P.: Flood dynamics in urbanised landscapes: 100 years of climate and humans' interaction, Sci. Rep., 7, 40527, https://doi.org/10.1038/srep40527, 2017.
Sorg, L., Medina, N., Feldmeyer, D., Sanchez, A., Vojinovic, Z., Birkmann, J., and Marchese, A.: Capturing the multifaceted phenomena of socioeconomic vulnerability, Nat. Hazards, 92, 257–282, https://doi.org/10.1007/s11069-018-3207-1, 2018.
Spielman, S. E., Tuccillo, J., Folch, D. C., Schweikert, A., Davies, R., Wood, N., and Tate, E.: Evaluating social vulnerability indicators: criteria and their application to the Social Vulnerability Index, Nat. Hazards, 100, 417–436, https://doi.org/10.1007/s11069-019-03820-z, 2020.
Tate, E., Rahman, M. A., Emrich, C. T., and Sampson, C. C.: Flood exposure and social vulnerability in the United States, Nat. Hazards, 106, 435–457, 2021.
Thieken, A. H., Bubeck, P., Heidenreich, A., von Keyserlingk, J., Dillenardt, L., and Otto, A.: Performance of the flood warning system in Germany in July 2021 – insights from affected residents, Nat. Hazards Earth Syst. Sci., 23, 973–990, https://doi.org/10.5194/nhess-23-973-2023, 2023.
UNISDR: Terminology on disaster risk reduction, United Nations Office for Disaster Risk Reduction, Geneva, https://unisdr.org/files/7817_UNISDRTerminologyEnglish.pdf (last access: 12 June 2024), 2009.
Vahedifard, F., AghaKouchak, A., Ragno, E., Shahrokhabadi, S., and Mallakpour, I.: Lessons from the Oroville dam, Science, 355, 1139–1140, 2017.
van Pelt, S. C. and Swart, R. J.: Climate Change Risk Management in Transnational River Basins: The Rhine, Water Resour. Manage., 25, 3837–386, 2011.
Vasileiadou, E. and Botzen, W. J.: Communicating adaptation with emotions: the role of intense experiences in raising concern about extreme weather, Ecol. Soc., 19, 36, https://doi.org/10.5751/ES-06474-190236, 2014.
Viglione, A., Merz, R., and Blöschl, G.: On the role of the runoff coefficient in the mapping of rainfall to flood return periods, Hydrol. Earth Syst. Sci., 13, 577–593, https://doi.org/10.5194/hess-13-577-2009, 2009.
Viglione, A., Merz, R., Salinas, J. L., and Blöschl, G.: Flood frequency hydrology: 3. A Bayesian analysis, Water Resour. Res., 49, 675–692, https://doi.org/10.1029/2011WR010782, 2013.
Villarini, G. and Smith, J. A.: Flood peak distributions for the eastern United States, Water Resour. Res., 46, W06504, https://doi.org/10.1029/2009wr008395, 2010.
Vorogushyn, S., Apel, H., Kemter, M., and Thieken, A. H.: Analyse der Hochwassergefährdung im Ahrtal unter Berücksichtigung historischer Hochwasser, Hydrol. Wasserbewirts., 66, 244–254, https://doi.org/10.5675/HyWa_2022.5_2, 2022.
Vreugdenhil, M., Széles, B., Salinas, J. L., Strauß, P., Oismueller, M., and Hogan, P.: Non-linearity in event runoff generation in a small agricultural catchment, Hydrol. Process., 36, e14667, https://doi.org/10.1002/hyp.14667, 2022.
Wang, W., Yang, S., Stanley, H. E., and Gao, J.: Local floods induce large-scale abrupt failures of road networks, Nat. Commun., 10, 2114, https://doi.org/10.1038/s41467-019-10063-w, 2019.
Wilby, R. L. and Dessai, S.: Robust adaptation to climate change, Weather, 65, 180–185, 2010.
Woo, G.: Downward Counterfactual Search for Extreme Events. Front. Earth Sci., 7, 340, https://doi.org/10.3389/feart.2019.00340, 2019.
Xu, Z., Zhang, Y., Blöschl, G., and Piao, S.: Mega forest fires intensify flood magnitudes in southeast Australia, Geophys. Res. Lett., 50, e2023GL103812, https://doi.org/10.1029/2023GL103812, 2023.
Short summary
Floods often take communities by surprise, as they are often considered virtually
impossibleyet are an ever-present threat similar to the sword suspended over the head of Damocles in the classical Greek anecdote. We discuss four reasons why extremely large floods carry a risk that is often larger than expected. We provide suggestions for managing the risk of megafloods by calling for a creative exploration of hazard scenarios and communicating the unknown corners of the reality of floods.
Floods often take communities by surprise, as they are often considered virtually
impossibleyet...
Special issue