Daniel Lincke (Germany) 1; Claudia Wolff (Germany) 2; Athanasios Vafeidis (Germany) 2; Jochen Hinkel (Germany) 1; Lukas Blickensdörfer (Germany) 3; Daria Povh Skugor (Croatia) 4
1 - Global Climate Forum; 2 - Christian-Albrechts-Universität Kiel; 3 - Humboldt Universität Berlin; 4 - UN Environment Mediterranean Action Plan Priority Actions Programme Regional Activity Centre (PAP/RAC)
The Mediterranean coastal zone is particular vulnerable to climate-induced sea-level rise due to a rapidly growing coastal development, leading to increased flood exposure in coastal areas. In Croatia, the share of developed coastline is still lower than in other Mediterranean countries, but with ongoing development of undeveloped areas. Available assessments of future coastal flood risk take into account adaptation by hard structural protection measures, but ignore other options like retreat from exposed areas or restricting future development. In this study we provide the first assessment of the effects of setback zones on future coastal flooding on national scale. We extend the flood impact and adaptation module of the DIVA modelling framework with models of restricted future development and slow retreat (managed realignment) in the form of setback zones, and apply this model to a downscaled database of coastal segments of the coastline of Croatia.
We find that setback zones are an effective and efficient measure for coastal adaptation. Both, construction restriction and managed realignment reduce future sea flood cost significantly, especially in combination with protection. If protection and construction restriction by setback zones are combined, future sea flood cost can be reduced by up to 39 percent. Combining protection and managed realignment by setback zones can reduce future sea flood cost by up to 93 percent.