Mutual increases in flood extents and magnitudes intensify flood hazard in Central and Western Europe

Author(s):  
Matthias Kemter ◽  
Bruno Merz ◽  
Norbert Marwan ◽  
Sergiy Vorogushyn ◽  
Günter Blöschl

<p>Climate change has led to changing flood synchrony scales (extents) and flood magnitudes across Europe. We discovered a tight alignment between extents and magnitudes and found the drivers of their joint trends. We analyzed the annual maximum floods of 3872 hydrometric stations across Europe from 1960-2010 and classified all floods in terms of their generating processes based on antecedent weather conditions. There is a positive correlation between flood extents and magnitudes for 95% of the stations. While both parameters increased in Central and Western Europe, they jointly decreased in the East. This widespread magnitude extent correlation is caused by similar correlations for precipitation, soil moisture and snowmelt. We found trends in the relevance of the different flood generation processes, which explain the regional flood trends. The aligned increases of flood extents and magnitudes emphasize the growing importance of transnational flood risk management.</p>

2020 ◽  
Author(s):  
Mattia Galizzi ◽  
Renzo Rosso ◽  
Daniele Bocchiola

<p>Flood risk in Italy is a wide-spread and never-ending issue. Traditional flood defense focused on making the river system “resistant” to flood events, possibly by flood-control structures including floodwalls, levees, dams and channels. These actions reduce the frequency of inundations, but they do not affect flooding effects, and associated impacts once the flood plain is inundated. In facts, structural flood defenses are designed and operated to accommodate floods not exceeding a given magnitude, as fixed by the original design. Thus, these engineering works are highly inefficient to cope with capacity-exceeding floods, the magnitude of which was fixed many years ago using poor data sets, and it is expected to increase with climate changes.</p><p>FLORIMAP (Smart FLOod RIsk MAnagement Policies), a project funded by Fondazione CARIPLO aims to revalue extreme floods distribution in the different homogeneous areas of northern Italy using regional approaches based upon recent data form the last three decades.</p><p>FLORIMAP will first cover open issues associated with the quantification of flood hazard and inundation risk, then it will assess human exposure and vulnerability, and combine these issues with strategies of communication and risk management, because risk communication is an important activity that can influence the flood risk management. Communication is the bridge between the technical and professional community, decision makers, elected officials, funding sources, and the public at large. The literature on risk communication and perception has highlighted that the understanding of the psychological perception of environmental risk is a crucial factor in order to foster the community resilience and to promote adaptive attitudes and behaviors.</p><p>Here, we present a preliminary assessment of updated extreme values distribution for the case study of Northern Italy hydrologically homogeneous regions. The results will be then compared against those obtained with previous dataset dating until 1970, to study the evolution of flood hazard and inundation risk under recent climate change. We then provide application of flood hazard, and risk for a case study area, and demonstrate modified hazard under recent climate change.</p><p>We then discuss implications for risk communication in the target areas, and provide suggestions for prosecution of the FLORIMAP project. </p>


2018 ◽  
Vol 94 (1) ◽  
pp. 1-18 ◽  
Author(s):  
Haixing Liu ◽  
Yuntao Wang ◽  
Chi Zhang ◽  
Albert S. Chen ◽  
Guangtao Fu

2021 ◽  
Author(s):  
◽  
Toni Kekez

Many river basins are experiencing frequent flooding events with significant economic and other losses due to intensive precipitation as well as other atmospheric and hydrological conditions. European Flood Directive defined flood risk as a combination of flooding probability and possible adverse consequences on people, assets, cultural heritage and environment. Flood risk management considers implementation of different measures for mitigation and prevention of possible negative consequences related to flooding. Uncertainty can strongly affect the flood risk management process, especially near and during the flood event. A framework is proposed for implementation of uncertainty related to behavior of the endangered system in the flood risk assessment, in order to improve the decision-making process during the flood emergency response. The proposed framework is validated on the City of Slavonski Brod pilot site, where the results demonstrated that there is a significant flood hazard still present due to possible weir failure, despite the improvement of flood defense measures. Furthermore, the results demonstrated how flood risk value can significantly decrease by properly evacuating the affected population. Flood risk management on a strategic level requires a monetary quantification of possible flood risk, which is performed by calculating expected annual damage (EAD) based on the combination of flooding event probability and corresponding damages. A semi-analytic methodology is presented for estimation of expected annual damage based on the factor graph model, which enables integration of entire probability space as well as flexibility in defining input data. Furthermore, a novel approach is presented for definition of annual damage distribution based on first and second statistical moment and by employing Beta distribution. By analyzing the annual damage distribution as well as impact of different sources of uncertainty, the results demonstrated that there is a significant impact of extreme events with low occurrence probability on the expected annual damage.


2012 ◽  
Vol 22 (3) ◽  
pp. 518-536 ◽  
Author(s):  
P. J. Ward ◽  
W. P. Pauw ◽  
M. W. van Buuren ◽  
M. A. Marfai

2020 ◽  
Author(s):  
B. Thanga Gurusamy ◽  
Avinash D Vasudeo ◽  
Aniruddha Dattatraya Ghare

<p><strong>Abstract: </strong>Because of the uncertainty and high cost involved, the Absolute Flood Protection has not been considered as a rational decision. Hence the trend is to replace Absolute Flood Protection strategy by Flood Risk Management Strategy. This Paper focus on the development of Multiple Criteria Decision Making (MCDM) model towards Flood Risk Management (FRM) across Godavari Lower Sub-Basin of India using GIS based methodologies for Flood Hazard Zonation in order to achieve global minimum of the Flood predicted Risk level.  Flood Hazard Zone Map for the historical flood events obtained with the use of GIS based Digital Elevation Models across the study area have been presented and used for the estimation of Hazard Risk. Uncertainty (or Control) Risk levels of each Flood estimated using various Flood Forecasting methodologies have been compared for the selected locations of the study area. Effectiveness of Passive Flood Protection Measures in the form of Flood Levees has been quantitatively analyzed for the increase in the Opportunity Risk and corresponding reduction in the Flood Hazard Risk. Various types of Multi-Objective Evolutionary Algorithms (MOEAs) have been used  to determine a Compromise solution with conflicting criteria between Hazard Risk and Opportunity (or Investment) Risk and the results were compared for each of the selected levels of Flood estimated with corresponding uncertainty. Traditional optimization method in the form of Pareto-Optimal Front have also been graphically depicted for the minimization of both Hazard Risk Objective function and Opportunity Risk Objective Function and compared with those obtained using MOEAs. Watershed wise distribution of optimized Flood Risk variation across the Sub-basin has been presented graphically for both the cases of with and without active Flood Routing Measures. <strong>Keywords:  </strong>Flood Risk Management; GIS based Flood Hazard Zonation; Multi-Criteria Decision Making; Multi-Objective Evolutionary Algorithms; Godavari Lower Sub-Basin of India;</p>


2017 ◽  
Vol 41 (2) ◽  
pp. 222-237 ◽  
Author(s):  
Nicholas S Reynard ◽  
Alison L Kay ◽  
Molly Anderson ◽  
Bill Donovan ◽  
Caroline Duckworth

Floods are one of the biggest natural hazards to society, and there is increasing concern about the potential impacts of climate change on flood occurrence and magnitude. Furthermore, flood risk is likely to increase in the future not just through increased flood occurrence, but also through socio-economic changes, such as increasing population. The extent to which adaptation measures can offset this increased risk will depend on the level of future climate change, but there exists an urgent need for information on the potential impacts of climate change on floods, so that these can be accounted for by flood management authorities and local planners aiming to reduce flood risk. Agencies across the UK have been pro-active in providing such guidance for many years and in refining it as the science of climate change and hydrological impacts has developed. The history of this guidance for fluvial flood risk in England is presented and discussed here, including the recent adoption of a regional risk-based approach. Such an approach could be developed and applied to flood risk management in other countries, and to other sectors affected by climate change.


Author(s):  
O. M. Kozytskyi ◽  
S. A. Shevchuk ◽  
I. A. Shevchenko

Background of the study. Due to the increasing intensity and frequency of catastrophic floods occurrence, one of the most important tasks of the water management of Ukraine is to increase the efficiency of the existing system of flood protection due to the implementation of integrated flood risk management methods based on the assessment of flood hazard levels requirements according to Directive 2007/60/EC. The development of scientific and methodological bases for the assessment and mapping of flood hazard and risk levels, as well as the development of integrated flood risk management plans based on them, is an important and urgent task in Ukraine as an associated EU member. The purpose of the work is to highlight the main works results, performed at the Institute on the study of patterns of riverbed transformations, the development of strategies for flood risk management and scientific and methodological support of the assessment and mapping of flood hazard and risk, taking into account the nature and the intensity of river bed transformation and exogenous processes in river basins of Ukraine. Outline of the main material. Systematic research on flood protection issues and river bed evolution in IWPaLR has been conducted since the middle of the last century. The problems of the dynamics of river bed’s evolutions, ensuring the stability of dams, erosion of the tail water of dam, development of active hydraulic structures and their arrangement in river beds, forecasting river bed evolution, runoffs, development study of permissible (nondestructive) flow velocities for alluvial soils, taking into account the phenomenon of self-patching of the river bed, the dynamic equilibrium of the beds, the typing of the beds of mountain rivers, etc., were studied and solved under the natural conditions and in the hydraulic laboratory of the Institute. Based on the results of theoretical and experimental studies of river bed evolution, a number of methodological provisions on the complex regulation of channel deformations and safe passage of high floods were formulated and published a number of regulatory and methodological documents on the calculation and forecasting of river bed transformations, designing of dams and protection structures. An important role was given to the issues of regulation and redistribution of floodwater by the system of river reservoirs and replenishment of groundwater reserves. The methodological recommendations for sampling of river bed deposits and sediments, on the base of the international ISO standards’ requirements and recommendations of have been developed at the Institute, as well as the method of estimation of the river bed transformation’s dynamics, for the discrete and quantitative assessments of river bed deformations and their intensity. The paper also highlights the main results of work on the implementation of the Flood Directive 2007/60/EC in Ukraine, in particular, the development of a Flood Risk Management Strategy in the Ukrainian Carpathian River basins. In the Strategy declared the latest approaches to flood response, which foresee the abandonment of the current paradigm of "flood protection" to favor integrated flood risk management. It defines national mechanisms of strategic management in the field of flood risk reduction, directions of transboundary cooperation, coordination of works within river basins. For the future development of this Strategy, the paper presents the scientific and methodological bases for a comprehensive assessment of the total levels of flood hazard and flood risk and their mapping on a GIS basis. Conclusion. In the future, scientific research on integrated flood risk management should focus on the study of patterns of evolution of river bed and development of mathematical models of regulation of channel deformations, improvement of the flood forecasting and prevention methodology based on simulation modeling, as well as the development new management schemes for runoff ‘s regulation.


Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2643
Author(s):  
Flavia Simona Cosoveanu ◽  
Jean-Marie Buijs ◽  
Marloes Bakker ◽  
Teun Terpstra

Diversification of flood risk management strategies (FRMS) in response to climate change relies on the adaptive capacities of institutions. Although adaptive capacities enable flexibility and adjustment, more empirical research is needed to better grasp the role of adaptive capacities to accommodate expected climate change effects. This paper presents an analytical framework based on the Adaptive Capacity Wheel (ACW) and Triple-loop Learning. The framework is applied to evaluate the adaptive capacities that were missing, employed, and developed throughout the ‘Alblasserwaard-Vijfheerenlanden’ (The Netherlands) and the ‘Wesermarsch’ (Germany) pilot projects. Evaluations were performed using questionnaires, interviews, and focus groups. From the 22 capacities of ACW, three capacities were identified important for diversifying the current FRMS; the capacity to develop a greater variety of solutions, continuous access to information about diversified FRMS, and collaborative leadership. Hardly any capacities related to ‘learning’ and ‘governance’ were mentioned by the stakeholders. From a further reflection on the data, we inferred that the pilot projects performed single-loop learning (incremental learning: ‘are we doing what we do right?’), rather than double-loop learning (reframing: ‘are we doing the right things?’). As the development of the framework is part of ongoing research, some directions for improvement are highlighted.


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