Geospatial Discovery of Promising Groundwater Abstraction Zones through Weighted Linear Combination and Probabilistic AHP Approaches

Abstract

Abstract Global water shortages are getting worse due to the effects resulting from climate change and rising groundwater abstraction. The current study's objective is to evaluate groundwater possibility zones for abstraction (GPZ) in the Dhaka division employing Remote Sensing (RS) and Geographic Information System (GIS) methods. A combination of Linear weight (WLC) along with the Analytical Hierarchy Process (AHP) was employed, integrated with Arc-GIS, to discover Groundwater Possibility Zones for abstraction of a region that spanned from the district's boundaries to 6 kilometers outside. The rate of groundwater abstraction, precipitation, LULC sequence, roughness of the earth's surface, drainage patterning, recuperate stipulation, geomorphology, and the possibility of evapotranspiration (PET) are several variables that affect the area's declining groundwater levels. The settlement area's density of water drainage and penetration region were altered to mitigate the adverse impact on the findings, and seven thematic layers were employed to determine the GPZ for abstraction. The GP estimate found that "shallow" groundwater potential zones covered 6018 km2 (24%) and that "low," "average," "high," and "extremely high" potential zones covered 5143 km2 (19%), 2150 km2, 3138 km2, and 4154 km2 correspondingly. Drainage density was discovered to be the most delicate factor. Based on seven physiographic, geomorphologic, and hydrological characteristics (i.e., precipitation, use of land and vegetation cover, concentration of drainage, contour density, and gradient), both WLC and AHP assessments have been carried out in this instance. The estimated net replenishment quantity for the years 1992 to 2022 was assessed utilizing the concept of the Water Table Fluctuation method.