Integrated BWM–GIS assessment of managed aquifer recharge potential in the transboundary Hari River Basin

Identifying suitable sites for managed aquifer recharge (MAR) is essential for enhancing groundwater sustainability in arid regions. This study integrates GIS-based spatial analysis with the Best–Worst Method (BWM) to delineate MAR potential across the transboundary Hari River Basin. Eight key hydrogeological and geomorphological criteria—lithology, soil texture, slope, curvature, drainage density, land cover, distance to faults, and fault density—were evaluated. Expert-based weighting using BWM yielded a strong consistency ratio (0.056), ensuring reliable prioritization of criteria. The weighted factors were combined using the Weighted Linear Combination (WLC) method to generate the recharge suitability map. The results show that lithology is the most influential parameter, followed by soil texture and distance to faults. Approximately 58.6% of the basin falls within high and very high suitability zones, mainly in central and western areas characterized by permeable sandstone, coarse soils, gentle slopes, and low drainage density. Conversely, shale-dominated and steep mountainous regions exhibit low recharge potential. The developed BWM–GIS framework offers a robust and transferable approach for MAR site selection and provides valuable guidance for groundwater management and transboundary water planning in the Hari River Basin.