Spatiotemporal dynamics of mangrove forests in the Andaman and Nicobar Islands (India)

Abstract

Mangrove forests provide multiple ecosystem services, such as primary production, coastal area protection, carbon fixation, and function as habitat for various plant and animal species. Despite the fact that these plant communities have proven effective in coastal area protection against typhoons and tsunamis, the 2004 Indian Ocean Tsunami caused the destruction of a large areas of mangrove forests in the Andaman and Nicobar islands in the Bay of Bengal. In this study, we investigated the decadal changes in mangrove forests in this region, including the decline in the mangrove areas before and after the 2004 Tsunami and the recent changes in the tsunami devastated mangrove areas since then, using Landsat series and Sentinel 2 data. In order to understand how these mangrove forests survive under the sea level rising scenarios, we estimated the possible changes in the land cover when a 1m rise in the current sea level occurs. It is estimated that 15% of the mangrove areas in this region were lost between 1988 and 2018. Even though the overall mangrove areas were shrinking, its causes are relatively different from the north to the south of the Andaman Islands. While the mangrove forests in the southern regions can be affected by natural phenomena such as tsunamis and sea level rise, those in the northern region are being depleted due to logging and land use changes. It is estimated that a 1m rise in the current sea level will result in the loss of 17% (117 km2) of the mangrove areas (the inward migration of mangrove vegetation was not considered).