Assessment of Shoreline Changes and the Groundwater Quality along the Coast of Kuakata, Patuakhali, Bangladesh

Abstract

Shoreline changes and groundwater quality monitoring have become pressing issues for the coastal region of Bangladesh. This study investigated the shoreline changes from 2000 to 2020 and evaluated the groundwater quality, as well as SWI in the Kuakata coastal area. While analyzing satellite images, the temporal shoreline changes were assessed through the Digital Shoreline Analysis System (DSAS) in ArcGIS 10.4.1. Higher erosion rates (>2 m/year) were found in the southernmost part and the SE part of the studied area. Twenty-five groundwater samples were collected, and the physicochemical parameters were measured to assess the groundwater quality. The geographic information system (GIS) was used to assess the spatial variation of the EC, pH, and Cl⁻ contents through the inverse distance weighted (IDW) interpolation method. The EC, Cl⁻, and pH values of the studied groundwater ranged from (1.2 mS/cm to 19.5 mS/cm), (79.88 mg/L to 11241.67 mg/L), and (7.9 to 8.7), repectively. The analysis revealed that the majority of the groundwater samples were unsuitable for drinking purpose due to higher EC and Cl⁻ values. Saline water intrusion (SWI) was determined by using the alternative EC vs Cl⁻ method in the southern part of the Kuakata beach area, which was closest to the sea.