Assessing the Impact of Urban Expansion on Groundwater Recharge Potential Using GIS-based Multi-criteria Analysis: A Case Study of Kahramanmaras¸, Türkiye (2000–2025)

Urban expansion threatens groundwater sustainability, yet regional-scale assessments can mask localized impacts. This study presents a GIS-based multi-criteria framework to quantify this ‘paradox of scale’, assessing the conflict between urban growth and the potential of groundwater recharge at Kahramanmaras¸, Türkiye, during the period 2000–2025. Using open-source datasets (GHSL, CHIRPS and SoilGrids), natural recharge potential was modelled, and annual loss attributable to urbanization was quantified. Although the regional mean groundwater recharge potential index (GRPI) declined only marginally (0.449→0.447) during this period, spatial analysis revealed a disproportionate, effectively irreversible loss within the most critical recharge zones. In total, 10.7 km² (3.55%) of top-priority ‘hotspot’ areas were converted to urban land, with losses unevenly distributed; the faster-urbanizing district forfeited a larger share of its hotspots. These findings indicate that reliance on regional averages is inadequate for sustainable planning. The resulting hotspot map provides a decision-ready tool to prioritize conservation of strategic recharge zones and strengthen long-term water security in rapidly urbanizing regions.