Large-Scale Evaluation of Beach Morphodynamic Evolution and Environmental Drivers Along China's Eastern Coast Through Long-Term Landsat Analysis

Abstract

Beach evolution severely impacts the economy and social well-being of coastal communities, posing a threat to the safety of coastal infrastructure. Under the influence of rising sea levels and other various environmental variables, the coastal morphology of Eastern China has undergone significant changes, particularly in the low-lying beach areas. It is crucial to gain an in-depth understanding of how environmental variables drive the dynamics of beach morphology, to predict the evolution of coastlines, and to devise effective climate adaptation strategies. However, little is known about the environmental drivers of beach morphodynamic evolution. In this study, we employ automated spectral analysis to detect the morphodynamic evolution of China's eastern beaches from multi-decadal Landsat satellite imagery. We conduct large-scale quantitative processing of four environmental drivers—waves, sea-level rise, typhoons, and sediment concentration. A multi-drivers stepwise regression method that considers interactions between factors is employed to quantify the effects of environmental drivers on beach morphodynamic evolution, yielding standardized coefficients for sea-level rise, typhoons, sediment concentration and wave-typhoon interaction of −0.184, −0.295, 0.891, and −0.230, respectively. Finally, we conduct large-scale and high-resolution regional coastal morphology prediction along China's eastern coast. Based on the prediction results and in combination with the distribution of ports and aquaculture industries, we conduct the risk zone classification. This study provides decision support for the rational development and scientific management of coastlines, contributing to the formulation of prevention and mitigation strategies for coastal erosion and evolution.