Delineation of groundwater potential zones in Chalan Beel (inland wetland) for sustainable ecosystem in Lower Atrai River Basin NW Bangladesh

Groundwater plays a critical role in sustaining the ecological integrity and water security of the Chalan Beel, the largest inland wetland (5097 km2) in the Lower Atrai River Basin of northwestern Bangladesh. This study delineates groundwater potential zones (GWPZs) using an integrated Geographic Information System (GIS), Remote Sensing (RS), and Analytical Hierarchy Process (AHP) approach. Seventeen hydrogeological, topographic, climatic, and environmental thematic layers, including rainfall, soil type, soil permeability, groundwater level, aquifer depth, land use/land cover, geomorphology, drainage density, NDVI, and NDWI, were analyzed to evaluate groundwater recharge and storage potential. The AHP results indicate that rainfall (20%), soil type (16%), and soil permeability (13%) are the most influential factors controlling groundwater occurrence and recharge. The generated GWPZ map classified the study area into three categories: very high (65 km2, 1%), medium (3933 km2, 77%), and low (1099 km2, 22%) potential zones. Temporal NDVI analysis (1990–2024) revealed substantial changes in vegetation and moisture conditions, with the moderate NDVI class increasing from 45 to 67%, indicating improved vegetation cover and its strong association with groundwater recharge potential. The identified high- and moderate-potential zones provide important information for groundwater development, irrigation planning, and ecosystem conservation. The study offers a scientific basis for sustainable groundwater-dependent ecosystem (SGDE) management and supports informed decision-making for water-resource planning under increasing climatic variability and anthropogenic pressures in northwestern Bangladesh.