Assessing Coastal Dynamics of Ashtamudi Wetland using PlanetScope Imageries

Ashtamudi Wetland is highly vulnerable to threats such as land degradation, saline water intrusion, sea level rise, subsidence of structures, and decline in agricultural productivity. This study assessed shoreline and land use changes in the region from 2016 to 2024 using PlanetScope imagery at 3 m resolution. Satellite altimetry data was used for sea level information, and field surveys were conducted to validate the remote sensing results. During the study period, the region experienced maximum change in Munroe Island area and Ashtamudi mouth. The western margin of Munroe Island showed (showed as location A) an erosion of 2.5-26 m/year within 0.47 km length. Additionally, Munroe Island lost 0.16 sq. km mangroves during the study period. On the other hand, the Ashtamudi mouth experienced accretion at $7.9 \mathrm{~m} /$ year rate due to breakwater construction near Neendakara Harbour. The results are crucial for effective coastal management strategies and implementing sustainable land use practices.