A Novel Method to Detect Short-Term Erosion and Deposition Within the Intertidal Zones and its Application to the Large Radial Sand Ridges in China

This study proposes a novel method to detect short-term erosion and deposition within the intertidal zones based solely on waterlines extracted from high-resolution satellite images. The judgment of erosion or deposition is based on the intersection of waterlines, which can reflect topographic changes. The procedures of the method have been demonstrated by its application to the large Radial Sand Ridges in China, where erosion and deposition are drastic due to the strong tidal currents. The intertidal zones were divided into four elevation zones, and the Sentinel-2 satellite images were used to obtain the spatial distribution of erosion and deposition at each sub-zone. The results show that the drastic erosion and deposition detected are greatly linked with tidal creeks. The results had been further used for preliminary risk assessment of wind power structures within the study area. It is found that the southern wind power structures are more possible at risk. The method is an inexpensive way to preliminarily monitor large intertidal zones.