A GIS-based multi-criteria evaluation for rainwater harvesting suitability in Awi Zone, Northwestern Ethiopia

Water scarcity remains a major challenge in rural Ethiopia, where over 85% of the population depends on rain-feed agriculture and rainfall is highly seasonal and unevenly distributed. Although annual precipitation in the Awi Zone can exceed 1800 mm, poor retention and runoff lead to recurring water shortages. This study presents a spatially explicit suitability assessment for rainwater harvesting implementation in the Awi Zone, Northwestern Ethiopia, using a GIS-based Multi-Criteria Decision Analysis framework integrated with the Analytic Hierarchy Process. Five biophysical parameters rainfall, slope, drainage density, soil texture, and land use/land cover were standardized and weighted to generate a composite rainwater harvesting suitability map. The results showed that about 91% of the area falls under moderate to very high suitability classes, with nearly 50% categorized as highly suitable. Validation against 35 existing RWH structures confirmed an overall accuracy of 87% and a Kappa coefficient of 0.81, further supporting the reliability of the analysis. The limitation of this study is exclusion of socio economic factors like land tenure, population density and implementation cost. Nevertheless, the findings provide crucial spatial guidance for prioritizing rainwater harvesting investments and contribute to sustainable water management planning in topographically complex and rain-dependent regions. By highlighting priority zones, the study offer policy makers and development agencies a decision support tool to design effective and local adapted interventions.