Abstract
Abstract. It is not uncommon for a flood defence to be combined with other societal uses as a multifunctional flood defence, from housing in urban areas to nature conservation in rural areas. The assessment of the safety of multifunctional flood defences is often done using conservative estimates. This study synthesizes new probabilistic approaches to evaluate the safety of multifunctional flood defences employed in the Netherlands and explores the results of these approaches. In this paper a case representing a typical Dutch river dike combining a flood safety function with a nature and housing function is assessed by its probability of failure for multiple reinforcement strategies considering multiple relevant failure mechanisms. Results show how the conservative estimates of multifunctional flood defences lead to a systematic underestimation of the reliability of these dikes. Furthermore, in a probabilistic assessment uncertainties introduced by multifunctional elements affect the level of safety of the dike proportional to the reliability of the dike itself. Hence, dikes with higher protection levels are more suitable to be combined with potentially harmful uses for safety, whereas dikes with low protection levels can benefit most from uses that contribute to safety.
Highlights
1.1 Evolution of the flood risk approachWith rising sea level and an expected rise in extreme rainfall events due to climate change, many regions in the world are faced with increasing flood risk (Bouwer et al, 2010; Hirabayashi et al, 2013)
Both the probabilistic assessment of the additional multifunctional uses and the monofunctional assessment yield a lower probability of failure for each dike profile (Fig. 5)
The reliability increases by a factor of 10 in the probabilistic assessment compared to a monofunctional dike due to a favourable position of the structure in the critical slip circle
Summary
1.1 Evolution of the flood risk approachWith rising sea level and an expected rise in extreme rainfall events due to climate change, many regions in the world are faced with increasing flood risk (Bouwer et al, 2010; Hirabayashi et al, 2013). As of January 2017 the water-level exceedance-based national risk standards were replaced by a more complex full probabilistic approach to more effectively adapt to social and economic developments and climate change (Kok et al, 2016). The Dutch Water Act is the first to require the implementation of these principles on a nationwide scale While these approaches were developed for dikes that serve as flood protection only, in practice many dikes have features serving other functions than flood protection. It is still unclear how such multifunctional aspects of a flood defence must be included in probabilistic safety assessments
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
