Assessment of Shoreline Changes and its Impact on the Groundwater Quality Along the Coast of Kuakata, Patuakhali

Abstract

Most of the coastal aquifers in Bangladesh are adversely affected by shoreline changes and saline water intrusion (SWI) due to climate change, which currently, poses an immense threat to the quality of groundwater resources. This study investigates shoreline changes from 2000 to 2020 and evaluated the groundwater quality as well as SWI in the Kuakata coastal area. Analyzing satellite images the temporal shoreline changes were assessed through the Digital Shoreline Analysis System (DSAS) in ArcGIS 10.4.1. Higher erosion rates 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 EC, pH, and Cl⁻ content through the inverse distance weighted (IDW) interpolation method. Saline water intrusion (SWI) was determined by the alternative EC vs Cl⁻ method. The southern part of the Kuakata beach area, which is closest to the sea, had higher EC and Cl⁻ values where the erosion rate was higher. The samples collected from this part also showed higher salinity, which is not suitable for portable purposes compared to the northern part of the study area.