Integrated coastal flood design strategies: changing paradigm in flood risk management

The relation between the design of the flood protection infrastructure and the design of the urbanscape is the focus of this paper with the question on how these two types of design can consciously affect each other. The text presents the preliminary result of an interdisciplinary research conducted by a team of urban designers and hydraulic engineers on two pilot projects of coastal adaptation to extreme sea level rise on the North Sea: Vlissingen (NL) and Southend-on-Sea (UK). Spatial measures to accept the flood, land use change, water-proof housing developments and the use of nature-based solutions are described in relation to the urban fabric. The aim is to discuss models of flood risk reduction which are alternatives to the more conventional coastal flood protection strategies. A different designerly way of thinking and a great effort of description and analysis of the two cases have been enacted to enlighten the spatial qualities of the urban form and its long-term adaptability.Environmental Technology and Desig

Integrated urban flood design in the United States and the Netherlands

Spatial design integrates social, cultural, economic, and political perspectives with natural site conditions and man-made construction to plan for sustainable urban development. The current flood-risk-related challenges induced by climate change place pressure on designing cities in which both natural and man-made conditions can be imbalanced. Creating a purely engineered line of flood defense to restore this balance does not always work. The idea of living more closely with water includes the discipline of spatial design more into flood risk management than the current dominant paradigm. Following the probability approach defined as risk = probability × consequences, the current Dutch paradigm is focused on reducing the probability with dikes; the United States focuses on reduction of consequences by evacuation and recovery. This chapter focuses on urban design and planning strategies for reducing flood risk not just by a flood defense line such as a dike, but also reducing risk by means of urban development behind the dike. Integrated urban flood design must integrate site-built environment characteristics and natural systems, and simultaneously solve challenges posed by hazards. Effective design, therefore, must be conducted on the basis of hydraulic engineering knowledge, leading to spatial designs that introduce resilient urban qualities. Two cases for this approach are presented and compared: Vlissingen, the Netherlands and Galveston, Texas, United States.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Environmental Technology and DesignSpatial Planning and Strateg

Design & assessing the flood risk management paradigm shift: an interdisciplinary study of Vlissingen, the Netherlands

Mean sea level rise (SLR) could increase up to 2m by 2100, which would see damage caused by coastal flooding in Europe increase from €1.25bn per annum currently to €961bn in just over 80 years. Urban areas situated along the North Sea coastline are particularly vulnerable to extreme sea level rise (a combination of SLR, tide and storm surges). The main goal of this study is to assess the paradigm shift in flood risk management from reducing probability of the flood event to reducing its consequences in the city of Vlissingen, in the Netherlands. Two spatial adaptation strategies are modeled and compared by using spatial, climatic, and socioeconomic projections for the year 2100: the “Vlissings Model” and the “Spuikom Model”. The Vlissings Model is about increased coastal protection through the heightening of existing grey infrastructure by 3 m, which includes the dike and buildings constructed on top of it. The Spuikom Model is accepting and rerouting overtopping water towards an existing former backshore water basin. The study brings forth an interdisciplinary "Design & Assess" framework that brings together design strategies with flood damage models and cost/benefit analyses to compare the effectiveness of two paradigms in dealing with extreme SLR. Results show that raising the dike would ensure full protection from extreme events against an initial investment and maintenance cost of €215 mil. Accepting and rerouting overtopping water would, on the contrary, reduce the impact of the flood to €8,6 million damage and less than a hundred affected inhabitants, without requiring the construction of major infrastructure but of a flood retention basin integrated to the new urban development. On the other hand, the comparison between the two strategies remains complex in quantitative terms given the different cost-benefit assessment models for such interventions.Environmental Technology and DesignHydraulic Structures and Flood Ris