Setback zones can effectively reduce exposure to sea-level rise in Europe

Abstract

Coastal space is one of the most valuable assets of the EU coastal member states, as the coast is highly urbanized. Hard engineering has traditionally been employed to protect communities in coastal lowlands, but as this alternative becomes less sustainable and more costly, coastal managers are increasingly turning to landuse planning strategies, such as setback zones or managed retreat. To explore the efficiency of these planning tools in reducing future urban exposure to sea-level rise and associated hazards, we developed spatially explicit projections of urban extent that account for different socio-economic futures and various types of setback zones. We find that the establishment of coastal setback zones can reduce the exposure of new urban development by at least 50% in the majority of EU countries by 2100. Our results emphasize that future urban exposure to sea-level rise will be significantly influenced by the ways in which we plan, design, and develop urban space in the EU coastal lowlands.

Spatially interactive modeling of land change identifies location-specific adaptations most likely to lower future flood risk

“…First, for simplicity, we did not simulate restricting development in areas with high flood hazard, i.e., to proactively prevent construction that might require protection or be abandoned in the future. Restricting future development in FUTURES 3.0, however, is possible (e.g., using a spatial protection layer [see 56 for an example using FUTURES 2.0], or with a flood response function that uses managed retreat) and may be useful for planning 26 or scenario development that focuses on conservation of wetlands and other open spaces that provide flood protection services. Second, we used historical migration trends (1990–2015) to anticipate where displaced residents migrate, but it is also possible to incorporate “climate-aware” migration trends that anticipate how migration is influenced by climate 57 and climate change 1 , 18 , 20 .…”

“…Additionally, methods that focus on individual-level adaptive behavior tend to be computationally demanding, applicable only to specific locations, and challenging to scale up for broader contexts (e.g., agent-based models 2 , 20 , 21 or dynamic systems models 25 ). Important recent contributions have investigated the combined impact of urban expansion and global adaptation policies (e.g., coastal setback scenarios 26 ) in response to future flood hazard. However, it is crucial to acknowledge that communities vary in their vulnerability to flood hazard and their capacity to adapt 27 .…”