Storylines of the impacts in the Netherlands of alternative realizations of the Western Europe July 2021 floods

The 2021 summer flooding was an extremely rare event, driven by precipitation extremes that exceed Dutch design levels for flood protection of relatively small rivers and waterways. However, similar events in neighboring locations cannot be ruled out in the near future. The implications of such extreme rainfall amounts will vary by region,...

Large-scale stochastic flood hazard analysis applied to the Po River

Reliable hazard analysis is crucial in the flood risk management of river basins. For the floodplains of large, developed rivers, flood hazard analysis often needs to account for the complex hydrology of multiple tributaries and the potential failure of dikes. Estimating this hazard using deterministic methods ignores two major aspects of...

Accounting for the uncertain effects of hydraulic interactions in optimising embankments heights: Proof of principle for the IJssel River

Most alluvial plains in the world are protected by flood defences, for example, embankments, whose primary aim is to reduce the probability of flooding of the protected areas. At the same time, however, the presence of embankments at one area influences hydraulic conditions of downstream areas located on the same river. These hydraulic...

Impact of including interdependencies between multiple riverine flood defences on the economically optimal flood safety levels

In risk analysis of riverine flood defence systems, sections of flood defences are often considered separately, herewith ignoring their interdependence, e.g. due to the hydraulic response following dike breaches in the system. In previous studies it has been found that such interdependence can have a significant influence on flood risk estimates...

Large scale flood hazard analysis by including defence failures on the Dutch river system

To make informed flood risk management (FRM) decisions in large protected river systems, flood risk and hazard analyses should include the potential for dike breaching. 'Load interdependency' analyses attempt to include the system-wide effects of dike breaching while accounting for the uncertainty of both river loads and dike fragility. The...

Real time floodrisk management

The central issue for authorities (as well as the public) is how and when to respond to forecasted extreme water levels on rivers, lakes and along the coast and large-scale flooding is an actual risk. The decision-making process is influenced by contradicting information, overloads and gaps in information, rumours, uncertainties in forecasts,...

Influence of load interdependencies of flood defences on probabilities and risks at the Bovenrijn/IJssel area, The Netherlands

In the Netherlands, flood risk analysis is usually carried out for a location, without considering potential flood defence failures in upstream areas. This may result in significant over- or underestimation of flood risks. The effect of upstream failures on failure probabilities and flood risks in other areas is called load interdependence of...

Long-term strategies for flood risk management: Scenario definition and strategic alternative design

Flood risk management requires policy making for a relatively far and largely unknown future. Task 14 of Theme 2 in FLOODsite aims to provide methodological guidance on how to perform the design/development of long term strategic alternatives for flood risk management and how to assess their performance in different future scenarios. To begin...

Effects of river system behaviour on flood risk