Assessing the impact of land use scenarios on groundwater quality in Bahir Dar City, Ethiopia: a GIS, remote sensing, and WQI approach

Groundwater is an essential source of drinking water, yet its quality is increasingly affected by land use changes. This study assessed the spatial variability of groundwater quality and examined the impacts of different land use scenarios in Bahir Dar City, Ethiopia. Geographic Information Systems (GIS), remote sensing, and physicochemical analyses were integrated, including major parameters such as total dissolved solids, hardness, sulphate, conductivity, pH, turbidity, nitrate, iron, manganese, and nitrite. Ordinary Kriging was applied to map groundwater quality, and a Water Quality Index (WQI) was used for classification. WQI values ranged from 16.78 to 71.97, indicating excellent quality in 28.96% of the area, good quality in 64.64%, and poor quality in 6.40%. Scenario analysis showed that agricultural expansion and urbanization increased the extent of poor-quality groundwater, whereas reforestation significantly reduced it. These findings confirmed that land use patterns strongly influence groundwater quality and emphasize the importance of sustainable land management.