Optimal land identification for surface irrigation in lower and middle Awash sub-basin, Ethiopia: a multi-criteria decision analysis

Abstract

Agriculture is a vital sector of Ethiopia’s economy, yet the country frequently experiences recurring droughts in various regions. Despite possessing substantial water resources and land suitable for irrigation, Ethiopia utilizes only a fraction of its irrigation potential. This study employs Geographic Information Systems (GIS) and Multi-Criteria Decision Analysis (MCDA) to identify suitable areas for surface irrigation in the Lower and Middle Awash sub-basin. Key factors—such as slope, soil texture, soil salinity, soil depth, land use/land cover, and proximity to the Awash River—were analyzed using the weighted overlay tool in ArcGIS. The results indicate that 6.4% of the study area ishighly suitable for surface irrigation, while approximately 78.2% is moderately suitable. Additionally, about 5.3% of the land is classified as marginally suitable, and 10.1% is deemed not suitable for surface irrigation. Despite this potential, only around 0.96% of the study area is currently under surface irrigation, primarily within the highly and moderately suitable zones. The study concludes that approximately 83.3% of the area holds significant potential for surface irrigation, which could enhance agricultural productivity, reduce the impact of drought, and improve local livelihoods. This finding offers a valuable foundation for policymakers and stakeholders to design and implement sustainable irrigation projects in the study area and its surrounding environment. Future research should incorporate groundwater potential as a critical factor in identifying suitable areas for irrigation.