Assessing erosion of sandy beaches due to sea-level rise

Abstract

Abstract The prospect of accelerated sea-level rise in the coming century makes beach erosion more likely. Given the concentration of human habitation and infrastructure adjacent to sandy beaches, it is prudent to consider the implications of such changes. To select the most appropriate approach to evaluate this problem, three levels of increasingly complex assessment can be distinguished: (1) screening assessment (SA); (2) vulnerability assessment (VA); and (3) planning assessment (PA). SA and VA are amenable to analysis with a Bruun rule-based approach. SA can be quickly and effectively accomplished using a simple proportionality approach that shoreline recession is in the range of 100 to 200 times the sea-level rise scenario. For VA, a range of shoreline response scenarios can be estimated by selecting appropriate low and high offshore boundary conditions. PA ideally requires a comprehensive sediment budget approach. SA may trigger VA, which may in turn, trigger PA, depending on the results. The limitations of this structured approach are discussed.