GLOBAL INVENTORY OF BEACHES BACKED BY ARTIFICIAL STRUCTURES

Sandy beaches, which account for about 31percent of the world’s coastline (Luijendijk et al., 2018), have a high socioeconomic value (Cooley et al., 2022). Vousdouskas et al., (2020) projected that on a global scale, 50percent of the sandy beaches are under serious threat of erosion under the high emission RCP8.5 scenario by 2100. The projected shoreline retreat does not automatically translate into complete beach area loss since sandy beaches can translate landward as long as there is enough accommodation space. Only when sandy beaches have been “hardened”, by having artificial structures such as sea walls, or revetments on the back beach, they lose their natural adaptability to future sea level rise. This situation may lead to the complete loss of the sandy beach in front of the structure (Nordstrom 2014, Schonees et al., 2019). To date, the global quantity of “hardened” sandy beaches is still unknown. The global amount of hardened sandy beaches is an important knowledge gap to further disclose the information of sandy beaches that could face severe loss in the presence of chronic shoreline retreat.