Sand Dam Suitability Assessment Using Integrated Geospatial and Multi-Criteria Decision Analysis to Strengthen Water Security in Arid and Semi-Arid Regions: A Case of the Lower Awash Basin, Ethiopia

Water security is a critical issue in Ethiopia’s arid Lower Awash Basin due to increasing population and economic pressures on limited water resources. This study assesses the suitability of sand dam sites using a multi-criteria evaluation approach integrated with geospatial tools. Key biophysical factors slope, stream order, soil type, land use/land cover, runoff depth, and distance from roads were analyzed and weighted based on their influence on sand dam feasibility. Runoff in the basin ranges from 682 to 934 mm annually, with 69% of the area receiving between 820 and 930 mm. About 47.4% of the land features gentle slopes favorable for dam construction. Despite this, only 4.78% of the basin shows moderate to high suitability for sand dams. Soil analysis identified Fluvisols and Regosols as favorable, while Leptosols—covering 43% of the area—were unsuitable. Rangelands, covering 71.6%, showed moderate potential, while water bodies and flooded vegetation (2.3%) were highly favorable. Locations more than 4 km from roads, representing 79.6% of the area, were deemed safer for dam sites. Overall, just 1.2% of the basin is highly suitable for sand dams. These findings highlight the need for localized, data-driven planning to strengthen water security in arid regions.