DETERMINING SEASONAL SEAFLOOR DEPTH CHANGES AROUND OFFSHORE ISLANDS OF VIETNAM USING SENTINEL-2 AND GOOGLE EARTH ENGINE

This study focuses on determining bathymetric changes around offshore islands of Vietnam using remote sensing data available on the Google Earth Engine (GEE) cloud platform. Sentinel-2 multispectral satellite imagery was collected over three time periods, January 14, 2020, June 5, 2020 and June 15, 2021, coinciding with the wind season to analyze and calculate bathymetric changes. The results of the bathymetry compared to the field measurement points have coefficients of determination (R2) ranging from 0.83 to 0.94. The RMSE (Relative Mean Square Error) results obtained were 0.066 m, 0.048 m and 0.079 m, initially providing a map of seasonal bathymetry changes consistent with reality. This method demonstrates the efficiency and automation potential for tracking depth changes in the Vietnamese coastal region, especially around offshore islands. Moreover, it highlights the importance of continuous monitoring for environmental protection, navigation, and resource management.