Assessment of groundwater recharge potential zones in four villages of Bumbaire Sub-County, Uganda using GIS and the analytic hierarchy process
摘要
Groundwater is a critical resource for domestic and agricultural sustenance in Bumbaire Sub-County, Uganda, yet its availability is threatened by climate change and increasing demand in all sectors because of population growth. This study addresses the urgent need for sustainable management by delineating potential groundwater recharge zones in four selected villages (Kihunda, Bumbaire, Rwencence, and Kamutazya) using a GIS-based weighted overlay analysis. Thematic layers influencing recharge including slope, drainage density, rainfall, land use/land cover (LULC), soil type, and geology were developed from satellite imagery and publicly available data sources from both Uganda government and International Organizations websites like FAO and UMA. The relative significance of each factor was rigorously determined using the Analytic Hierarchy Process (AHP), which assigned the highest weights to slope (36.55%) and rainfall (29.67%), identifying them as the most critical determinants. These weighted layers were integrated to produce a comprehensive groundwater recharge potential map. The results successfully classify the area into very good zones of 15.33%, good areas of 30.73%, and low potential recharge zones of 53.94%. Very good areas were predominantly identified in eastern Bumbaire and northern Kamutazya, characterized by gentle slopes, favorable soil types like Humic Nitisols, and natural land cover that promotes infiltration. This map provides a vital scientific tool for integrated water resource management, guiding strategies for artificial recharge, land use planning, and the protection of vulnerable aquifers. The study demonstrates the efficacy of GIS and AHP as cost-effective and powerful techniques for groundwater exploration and sustainable planning in data-scarce regions, offering a replicable model for similar localities in Uganda and beyond.