Investigating rainwater harvesting potential for water sustainability in Tigray, Ethiopia

In the Tigray region of Ethiopia, water scarcity is common due to climate change, population growth and an uneven rainfall distribution, resulting in crop damage. Although several rainwater harvesting structures have been implemented in the area, their application has been site-specific, lacking systematic, technology-specific spatial frameworks. In this study, a geographic information system integrated with multi-criteria decision making was used for developing separate, context-calibrated suitability models for dams, check dams and percolation ponds, validated against 38 existing structures. Both biophysical and socio-economic criteria were selected through expert consultations and Delphi surveys. The results identified four dams, 17 check dams and 18 percolation pond sites, with validation accuracies of 76.92–100%. Stream order was found to be the most influential factor for check dams and percolation ponds, while soil texture was the most influential for dams. The central and eastern regions of Tigray were found to be the most suitable for dams, while western and northern regions are not suitable. Two identified dam sites should be prioritised based on their suitable topographic conditions, sufficient storage capacity and availability of irrigable command area. The results of this study can be directly applied by the Ethiopian government, Tigray Water Bureau, Abergele Woreda Agriculture Office and non-governmental organisations.