Assessing the dynamics of land cover and shoreline changes of Nijhum Dwip (Island) of Bangladesh using remote sensing and GIS techniques

Abstract

Land cover alteration is an important driver of ongoing global environmental change. Developing countries with a fast-growing population have not been able to control a sustainable land-use transition that simultaneously increases both forest cover and agricultural production. Coastal regions of these countries are vulnerable to natural hazards. The present study aims to detect the land cover changes with shoreline shifting in Nijhum Dwip of Bangladesh. A supervised classification method is used for the Landsat images of 1998, 2008 and 2018 based on eight significant land covers. A field survey also facilitates the locational accuracy of the classification. According to the study, about 285 hectares of mangrove forest has disappeared between 1998 to 2018. Agricultural lands reduce to 14.89% from 23.13%, whereas settlement cover has increased rapidly from 3.73% to 11.93%. About 1153 hectares of land area is added, as accretion rate is higher than erosion. Water cover climbed to 7.04% from 0.69% because of sea level rise. Shoreline is expanding towards north-western and south-eastern direction. The major causes of such changes are population pressure, expansion of settlement area, and sea level rise. The findings of the study will help the policy makers to formulate planning for sustainable coastal management in coastal region of Bangladesh.