**2. Study area**

The coastline along Sundarban area, unlike adjacent areas, is not restricted by embankments, making it a preferred study area to observe the impact of sea level rise and coastal erosion on the shoreline. Anthropogenic activities, such as fishing, hunting, and resource harvesting, occurs inside the inland river channel and their subsidiaries and inland forest area. Excessive humidity prevails throughout the year. The monsoon occurs in the months of June to September with 2500 to 3000 mm of rain fall annually. In the summer temperature ranges between 25 to 35°C, while winter has a temperature range of 12 to 24°C.

Tidal levels in the area exhibit seasonal variations, ranging from 4 to 6.5 meters. Additionally, the pH of the water fluctuates between 7.2 to 7.9 [12]. These environmental factors, including humidity, rainfall, temperature, tidal levels, and water pH, collectively contribute to the unique and dynamic ecosystem of the mangrove forest. Therefore, the study is focused on the coastline that is affected.
