Constructing intertidal topography for sandy beaches by combining Sentinel-2 imagery and water level data

Abstract

Sandy beaches are the most wide distributed coastal type worldwide, serving as a crucial transitional zone between land and sea. However, accurately mapping the intertidal zone of sandy beaches poses challenges due to water-level fluctuations and limited in-situ measurements in sparsely populated areas. Leveraging free-access Sentinel-2 optical imagery and station-based water-level data in coastal zones, we explored the integration of Sentinel-2 satellite imagery and water-level data to derive the intertidal topography of sandy beaches. Our study conducted in Texas, USA, demonstrates the generation of a detailed Digital Elevation Model (DEM) with an accuracy of 0.42 m. This satellite-derived intertidal topography offers valuable insights for mapping coastal lowlands and estimating coastal slopes of sandy beaches. In the future, our method holds significant potential for global-scale applications in generating intertidal topography, coastal slopes, and lowland areas for sandy beaches. Furthermore, our method can enhance our understanding of these important coastal environments and support decision-making for conservation and management efforts.