Adapting beaches to sea level rise: A sediment-based strategy for protecting coastal tourism in Catalonia (NW Mediterranean)

Coastal tourism is a vital economic sector in Mediterranean regions; however it is increasingly threatened by the loss of beaches. Ensuring the economic sustainability of these tourist destinations requires maintaining beaches as functional recreational spaces. This study examines the maintenance of the beach carrying capacity (BCC) as a long-term adaptation strategy for managing beaches along the Catalan coast (NW Mediterranean) under the impact of sea level rise (SLR) throughout the 21st century. It presents a methodological framework that integrates beach surface changes, BCC evolution, regional economic impacts, and adaptation costs by applying updated coastal evolution data and IPCC AR6 SLR scenarios. The results reveal significant vulnerability in Catalonia's tourism sector, particularly under high-emission scenarios (SSP5-8.5), with BCC levels potentially declining by 70 % and regional gross domestic product (GDP) dropping by 6.1 %. This study analyzes three beach nourishment-based adaptation strategies to maintain the BCC, assessing the required sediment resources and costs for each. Adaptation priorities can be determined based on the avoided GDP losses relative to nourishment costs, with the strategy being the most economically viable in areas with intensive sun-and-beach tourism. This study highlights the importance of economically informed adaptation strategies to mitigate the long-term effects of SLR on Catalonia's beach tourism and economy.