Evaluation of water harvesting structures on agricultural productivity: the case of Tigray Region, Ethiopia

摘要

The regional government of Tigray in collaboration with NGOs and donors has implemented many water harvesting technologies to improve the livelihood of the people. However, there is limited research that evaluates the productivity of water harvesting structures considering socio-economic, institutional and technical aspects. Thus, this study aims at filling the gaps in evaluating the impact of water harvesting technologies on agricultural productivity using socio-economic, institutional and technical criteria in the region. For the socio-economic evaluation cross-sectional data collected from a survey of 781 households were used and analyzed using mean separation tests and propensity score matching analysis. Institutional aspect was evaluated using qualitative information from focus group and key informant discussions. Performance indicators like irrigation efficiency, output per unit command, cost per hectare and environmental effects were used for technical evaluation. Probit estimation result indicated the members of water users association and cooperatives as well as access to institutional services have positive influence on adoption of water harvesting technologies. The average treatment effect results also showed that all water harvesting technologies except wells have positive and significant effect on improving agricultural productivity. Institutional evaluation results showed that water user associations are neither well established nor functioning properly. Technical evaluation results showed that irrigation efficiency ranges from 25 to 74% for spate and river diversion, respectively. Furthermore, output and investment cost per hectare are the highest for dam while they are low for hand dug wells and spate irrigation. Considering overall technical criteria river diversion is the most productive technology in the region.