Modelling land susceptibility to erosion in the coastal area of Bangladesh: A geospatial approach

This research aimed to develop a widely applicable raster GIS-based model for analysing susceptibility of coastal lands to erosion. The model, Land Susceptibility to Coastal Erosion (LSCE), was applied for the coastal area of Bangladesh as a case study. This study included three coastal zones (western, central and eastern) that cover the entire coastal area of the country. The outputs of the model comprised physical susceptibility of the coastal lands to erosion according to five susceptibility classes. The overall results demonstrate that out of the entire coastal area about 0.59% (266.32  km²) and 0.02% (10.01  km²) of the coastal lands exhibit high and very high susceptibility to erosion, respectively. These make 276.33 km² in total as being highly susceptible to erosion, which is noteworthy for the densely populated coastal area of the country. The remaining 5.49%, 20.56% and 73.34% of lands were identified as having moderate, low and very low susceptibility to erosion, respectively. The developed model is highly suitable for addressing the impacts of hydro-climatic parameters on susceptibility to coastal erosion. Hence, this study identified and mapped the influence of hydro-climatic parameters on the coast by assessing seasonal variations of susceptibility to erosion. The outputs were then validated by developing an inventory map and analysing independent historical observations by using ‘degree of fit’ curves. The LSCE model could be useful for coastal researchers in assessing erosion susceptibility of dynamic coastal lands around the world.