Coastal Landscape Development and Dynamics: A GIS-Based Case Study on Char Kasem, Patuakhali, Bangladesh

Bangladesh is a riverine country carrying a massive load of sediment and water, which forms many coastal charlands in the southern part of the country where these rivers drain into the Bay of Bengal. Considering this state, the coastal charlands of Bangladesh are highly dynamic as these change their size, shape, orientation, and other physical attributes frequently. Focusing on one of these chars, which is Char Kasem, an isolated coastal char of the Patuakhali district of Bangladesh, spatio-temporal dynamism, stability, shoreline shifting, digital elevation model (DEM), processes shaping the landform, land useland cover (LULC) change, and overall landscape development of the char is being assessed and evaluated from the year 1984 to 2024. The stability and shoreline shifting of the char are being analyzed by Google Earth Pro data and QGIS 3.16 software, which resulted in the char’s stable land declining, as does the shoreline. Elevation models are created using Google Earth Pro software’s elevation data, which GPS Visualizer later converts. These elevation models uncover that the higher the elevation, the higher the chance of stability of the charland and vice versa. The major geomorphic processes shaping the char are being identified through field surveys and quantified by Google Earth Pro software, which indicates that the erosion process outweighs the process of accretion in terms of significance, as 271 hectares of landmass are being eroded while only 46 hectares of landmass is being accreted in forty years (1984-2024). Google Earth Pro, ArcMap 10.5, and QGIS 3.16 visualize the LULC change and landscape development. The analysis implies that landforms of the char are maturing with significant changes as more people settle down, which impacts land use. The size of the char is decreasing steadily, and its ability to thrive is at risk if the present condition continues for an extended period of time.