Abstract

Nijhum Dwip is a southern island of Bangladesh isolated from the mainland in the convergence of the Meghna River and the Bay of Bengal This island has studied through overlay analysis and supervised classification by geospatial and remote sensing technique over 38 years 1980-2018 using multitemporal Landsat MSS TM OLI and TIRS satellite images with identification of historical changes This landform is facing frequent shifting of its coastline and leading to sequential changes on the land surface Analysis revealed substantial growth of settlement and agricultural land whereas significant lessening on vegetation cover and open space In 1990 agricultural land was 4 47 km2 13 29 and improved to 9 16 km2 19 17 in 2018 Similarly settlement also increased from 1 92 km2 4 79 in 1999 to 5 72 km2 11 97 in 2018 Conversely vegetation was primarily 8 02 km2 27 71 18 70 km2 55 61 20 97 km2 52 29 18 47 km2 36 28 and 15 28 km2 31 98 in 1980 1990 1999 2010 and 2018 indicating declination As well water bodies and open space also fluctuated through the period because of geomorphological processes and human intervention Besides the least and highest unstable char land was 1 15 km2 3 42 and 1 68 km2 5 80 in 1990 and 1980