Small dams/reservoirs site location analysis in a semi-arid region of Mozambique

The water crisis is one of the biggest human problems in developing countries, especially in semi-arid regions where it can form an obstacle to irrigation and cultivation, cattle raising and people's survival. The construction of small dams/reservoirs are a possible solution to remediate this problem. These infrastructures must be located in suitable areas to be successful. This study aimed to find the most suitable locations for small dams/reservoirs in the Tete province region, Mozambique, which has a pronounced water deficit. A Geographical Information System (GIS) based approach was used to implement a multicriteria evaluation (MCE) analysis through an Analytic Hierarchical Process (AHP), which included local experts' consultation. Three main categories of suitability were identified: Not suitable (15% of total area), Modestly suitable (78%), and Suitable (7%). We found that 35 of the 38 (92%) abandoned small dams/reservoirs were in areas classified as Modestly suitable confirming the robustness of our model. We also found that most of the dams/reservoirs currently operating (78%) and planned (73%) are in modestly suitable areas. This finding suggests that the decision to construct dams/reservoirs may not have considered the most critical suitability factors identified in this study. More data and/or additional criteria are required for the full understanding of finding out why so many dams/reservoirs failed before building new ones to address the population's water needs in the region. (C) 2021 International Research and Training Center on Erosion and Sedimentation, China Water & Power Press. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co. Ltd.

Automated summary

Using GIS and AHP method, this study identified the most suitable locations for small dams/reservoirs in the Tete province region of Mozambique. Results showed that most abandoned small dams/reservoirs were in areas classified as modestly suitable, while currently operating and planned dams/reservoirs were mainly located in similar areas, indicating that construction decisions may not have fully considered suitability factors.