Flood Impact on Mangrove Health Dynamics in Sagar Island of West Bengal: A Geoinformatics Based Approach

Mangroves are considered to be one of the unique ecosystems of the world. They are known for providing protection against the disastrous cyclones that originate in the Bay of Bengal during every pre-monsoon and post-monsoon cyclone season. Hence, they act as the lifeline of the people residing in the coastal areas and in its close proximity. However, mangroves are being destroyed rapidly due to climate change, cyclone-induced flooding, and large-scale anthropogenic interference. The present research makes an attempt to gained insight into the changing nature of the mangroves of the Sagar Island in the South 24 Parganas district of West Bengal both on a qualitative and quantitative basis. The study has used GIS and remote sensing technology and satellite images in both Landsat and Sentinel 2A for the years 2023 for this purpose and employed the Fuzzy Analytical Hierarchy Process (FAHP) to generate the mangrove health diversity model. The study has also computed MABAC for the detection of moisture status within the mangroves and land surface emissivity rate from the mangrove dominated soil. The results reveal a significant decline in the health as well as quantity and density of mangrove forests of Sagar Island with time, and hence, there is an urgent need to take preventive measures to save the coastal lifeguards. The study also states that the involvement of local people and utilization of their ecological knowledge will be the most effective tool to save the mangroves.