Contribution of Spatial Techniques to the Identification of Discontinuous Basement Aquifers in Semi-Arid Zones: The Case of the Precambrian Basement of Damagaram-Mounio, Centre-East-Niger

The study area, the Damagaram basement, located in the central south of the Zinder region, has a discontinuous aquifer characterized by a very high failure rate of hydraulic structures (wells and boreholes) and a very low flow rate. In order to improve knowledge of these aquifers and provide access to drinking water for the population of this area, satellite imagery (landsat and aeromagnetic) and field measurement data were used to map fractures. Several techniques, including spatial and directional filtering, were applied to these satellite images to identify, extract and classify the lineaments. The results were validated by previous work and outcrop measurements. Analysis of the spatial distribution shows fractures in the directions N20°-30°; N30°-40°; N40°-50°; N50°-60°; N60°-70°; N70°-80°; N90°-100°; N100°-110°; N110°-120°; N120°-130°; N130°-140°; N140°-150°; N150°-160°; N160°-170° with varying numbers and cumulative lengths. Thus, five major fracture families characterized by directions that are : N40°-60°; N140°.