THE SATELLITE DERIVATION OF DEPTH AND TOTAL SUSPENDED SOLIDS ASSESSMENT FOR ESTUARINE EROSION MONITORING WITHIN NARROW STRAIT USING SENTINEL-2A SATELLITE IMAGES

Abstract

Estuaries are crucial marine areas for important hydrodynamics processes, such as sediment transport for supporting other marine ecosystems like mangrove forests. This study explores the relationship between total suspended solids (TSS) and water depth within a narrow strait area with Sentinel-2A satellite images. The gravimetric method and Normalize Suspended Material Index (NSMI) were used for TSS analysis and estimations. In contrast, the bathymetric survey and Stumpf ratio transform were used to validate and estimate the water depth from the satellite images. The estimation process begins with an assessment using 2018 in-situ data and further analysed for their differences between 2018 and 2020 using Sentinel-2A images comparison. This study found a relatively moderate estimation between water depth and satellite imagery at 53%, and the TSS estimation results show a stronger relationship of up to 80% as they were both analysed separately. The relationship between TSS and water depth shows a solid connection, which explains the correlation of 75–82% between them by the satellite images. The strong connection of estimation for depth and TSS within the narrow strait suggests continuous monitoring is reliable to support decisions for immediate action at estuarine areas.