Spatial distribution of water reservoirs in the Sota catchment (Benin, West Africa) and implications for local development

Water is an indispensable resource for human being and the environment. This study analyses spatial distribution of water reservoirs in the Sota catchment with regards to livestock density, population density, rainfall distribution and geological structure of the Sota catchment, and assessed the state of these reservoirs. To this end, the geographic coordinates of water reservoirs were collected and the updated database of reservoirs census in Benin, was used. In addition, livestock and population census database, rainfall data from 1980 to 2016 of twelve (12) stations and geological database were processed in ArcGIS for generating respectively the spatial layers of livestock, population, rainfall and geological map of the catchment. The reservoirs' state has been appreciated by documents exploration and in situ observations. Single factor Regression analysis was conducted to understand the relation of each of the factors with the spatial distribution of the reservoirs in the Sota catchment. The results reveal that Sota catchment contains 35 small water reservoirs mostly concentrated in its central western and south western part. The reservoir density is 0.0026 km−2. Most of the reservoirs are located within areas where livestock density, population density and rainfall amount is high: 51%, 46% and 86% respectively. However, no significant relation was found between reservoirs distribution and livestock density, population density, and rainfall respectively in the catchment. The basement geological structures of the Sota catchment are associated with 71% of the reservoirs' location. The reservoirs are threatened by siltation, lack of pastoral facilities, poor maintenance and management. In fact, 100%, 86%, 74%, 71%, 40%, and 34% of reservoirs are respectively subjected to the issues of: absence of waterers, siltation, deteriorated dyke, eutrophication, inexistent management committee, and drying up in dry season. For sustainable local development purposes, more attention should be paid to basin management planning for construction of new reservoirs and to reservoirs ‘maintenance. Future research on the reservoirs’ sustainability and monitoring surveillance are recommended.