Time-series analysis of landcover dynamics and their relation with coastline migration along Kuakata coast, Bangladesh using remote sensing techniques

Time-series analysis of satellite imageries is useful in studying changes in coastlines and the nature of the landcover dynamics in coastal environments. This study aimed to investigate the relationship between coastal erosion-accretion and landcover changes in Kuakata. Landsat TM and Landsat OLI/TIRS satellite imageries at a nearly 5-year interval between the years 1989 and 2020 were used to compare changes within five major landcover classes in the study area – 1) mangrove vegetation, 2) settlements, 3) agricultural land, 4) waterbody and 5) beach. Net land loss over the past 31 years was estimated to be 1.73 km2 within the 93.05 km2 study area. Linear regression rates were calculated to identify the area most prone to erosion. The average erosion rate along the coastline was estimated to be 2.09 m/year. Most erosion occurred along the western part of the coast while the highest accretion was limited to an area in the east. Study findings also suggested that changes in beach and mangrove vegetation classes have a significant spatial and statistical correlation with coastal erosion-accretion processes. These findings can help the policymakers implement coastal zonation, and preventive and rehabilitative measures to save the tourism industry and agriculture in Kuakata.