Climate change driven shoreline change at Hasaki Beach Japan: A novel application of the Probabilistic Coastline Recession (PCR) model

Low elevation coastal zones around the world are increasingly threatened by the effects of climate change, and adaptation in these areas is becoming urgent. One of these threats, especially to sandy beaches, is the slow chronic landward movement of the coastline, known as coastal recession. The Probabilistic Coastline Recession (PCR) Model is a physics-based approach that is specifically designed to support modern day risk informed coastal zone management. Here, the PCR model is applied at the highly monitored Hasaki Beach in Japan, which presents challenges that have hitherto not been experienced in previous applications of the model elsewhere in the world (e.g. lack of a clear correlation between high wave events and beach erosion, no storm erosion of dunes but only of the beach strong seasonal variation in erosion events). Therefore, the model is here applied following a novel approach to derive projections of coastal recession (here indicated by shoreline retreat) at Hasaki, under the two end-member IPCC scenarios (RCP 2.6, RCP 8.5.)