Delineation of groundwater potential zones in Gazipur district using fuzzy logic techniques and GIS-remote sensing

The escalating global water crisis underscores the urgent need to evaluate groundwater potential, particularly in regions like Bangladesh where safe drinking water is increasingly constrained. This study delineates groundwater potential zones (GPZ) in the Gazipur District by integrating fuzzy logic techniques with Geographic Information System (GIS) analysis. Twelve thematic layers such as slope gradient, drainage density, roughness, profile curvature, plan curvature, topographic wetness index (TWI), geology, lithology, rainfall, soil texture, land use/land cover, and aspect were utilized to generate a composite groundwater potential model. Each parameter was converted into a fuzzy membership value, and the layers were subsequently combined using a fuzzy overlay approach. The final GPZ map indicates that 44.29% (785.31 km2) of the district falls within the very high potential zone, 51.79% (918.26 km2) within the high zone, 3.47% (61.57 km2) within the moderate zone, 0.23% (4.09 km2) within the low zone, and 0.001% (0.0045 km2) within the very low zone. Model validation using 19 Bangladesh Water Development Board (BWDB) observation wells demonstrated an accuracy of 89.47%, confirming strong agreement between predicted groundwater potential and observed water level conditions. Overall, the study demonstrates that integrating fuzzy logic and GIS provides an effective and reliable approach for groundwater potential zone assessment. The resulting GPZ map offers valuable guidance for sustainable groundwater management, artificial recharge planning, and land-use decision-making in rapidly urbanizing regions such as Gazipur.