Modeling spatio-temporal shoreline and areal dynamics of coastal island using geospatial technique

Abstract

This study aimed at assessing the changes in the shoreline and the area of Sandwip Island, Bangladesh using multi-temporal satellite image and geospatial techniques. The study results (1980–2014) indicate that the island has gained approximately 25 km2 land areas and has lost about 64 km2 of its original land area during this time. The net loss of the shore-length was approximately 3.1 km or 0.1 km/year and the net loss of 38.84 km2 or 1.14 km2/year areas. The erosion process has been taken place along the western, south-western, and southern banks of the island. In these areas, the landward movement and rate of the shoreline were higher with a highest value of the net shoreline movement (NSM) around 3.8 km and the end point rate (EPR) more than 100 m/year in some parts. The accretion, on the other hand, has been taken place along the northern and north-eastern banks of the island at relatively slower rates with the NSM <2.8 km and the EPR <100 m/year.