Groundwater quality evaluation for irrigation using irrigation water quality indexes under GIS framework in Aksum Area, Northern Ethiopia

This study evaluates the suitability of irrigation water in the semi-arid region of Aksum, northern Ethiopia. An integrated approach combining the Irrigation Water Quality Index (IWQI) and ArcGIS-based spatial analysis was applied to assess the spatial variability of irrigation water quality. Twenty-five groundwater samples were collected and analyzed for key physicochemical parameters and heavy metals using standard laboratory techniques. Exceedances of recommended irrigation water limits were recorded for magnesium (16%), nitrate (32%), salinity hazard (12%), total dissolved solids (20%), total hardness (60%), residual sodium carbonate (16%), kelly index (4%), and magnesium ratio (32%). Based on the Irrigation Water Quality Index (IWQI), 36% of the samples fell under high restriction, 32% under moderate restriction, 24% under severe restriction, and 8% under low restriction for irrigation use. Although most of groundwater sources are suitable based on individual water quality parameters, the IWQI indicates that a significant portion of samples requires restricted use for irrigation. This highlights the need for targeted groundwater management strategies to mitigate localized risks associated with salinity and sodicity. The integrated IWQI-GIS approach demonstrated in this study is readily transferable to other arid and semi-arid regions, providing a robust tool for sustainable irrigation management and climate-resilient agricultural planning.