IDENTIFYING SUITABILE RAINWATER HARVESTING SITES USING GIS AND MULTI CRITERIA DECISION APPROACH IN RAYA KOBO WOREDA, NORTHERN ETHIOPIA

In Ethiopia, extreme rainfall variability is a primary driver of famine and environmental degradation, underscoring an urgent need for sustainable water management solutions like rainwater harvesting (RWH). This study aimed to identify optimal RWH sites in the water-scarce Raya Kobo Woreda using an integrated approach of Geographic Information Systems (GIS) and Multi-Criteria Decision Analysis (MCDA). The methodology involved generating a potential runoff map and applying the Analytical Hierarchy Process (AHP) to assign weights to key suitability factors: soil texture, slope, land use/cover, drainage density, and runoff depth. The study using AHP generated a detailed suitability map by weighing key factors like soil type, slope, and land cover. The study findings suitability map reveals that only a small fraction of the area is highly (0.05%) or moderately (2.68%) suitable for RWH, while the majority is classified as marginally (43.03%) or less suitable (53.8%). This research demonstrates the efficacy of GIS-MCDA for RWH planning and provides a valuable spatial decision-support tool for resource managers and government agencies to strategically implement RWH interventions, offering a supplemental water source to bolster community resilience and ecosystem services.