摘要
The study area, located in the Liptako basement of Niger, faces a serious problem of drinking water supply in recent decades. This is linked to exponential population growth and reduced rainfall. The purpose of this study is to map fracture networks from Landsat 7 satellite imagery to identify major subterranean flow corridors in the area. The methodological approach based on the collection of data (Landsat 7 images, DEM/SRTM, flow, transmissivity, static level) and the geological and hydrogeological field reconnaissance and the processing of these data with the following software (ArcGis, Envi, Surfer and RStudio) The results of this study yielded that the number of satellite lineaments is 995, the preferred directions of these satellite lineament are: N0°-10° (13%) and N90°-100° (12%). On the hydrographic network, in situ, the most frequent fracture, vein and dike directions are: N90°-100° (12%), N130°-150° (11%), and N50°-60° (10%). The structural domains identified probably correspond to the main corridors and reservoirs of underground flows. The values of the induced permeability are between 0.05 × 10-8 and 3.4 × 10-7 m/s. The permeability induced by satellite lineaments, which is strongly related to high fracturing densities and major water stream is involved in the hydrodynamic functioning of discontinuous aquifers in the study area.
The study area, located in the Liptako basement of Niger, faces a serious problem of drinking water supply in recent decades. This is linked to exponential population growth and reduced rainfall. The purpose of this study is to map fracture networks from Landsat 7 satellite imagery to identify major subterranean flow corridors in the area. The methodological approach based on the collection of data (Landsat 7 images, DEM/SRTM, flow, transmissivity, static level) and the geological and hydrogeological field reconnaissance and the processing of these data with the following software (ArcGis, Envi, Surfer and RStudio) The results of this study yielded that the number of satellite lineaments is 995, the preferred directions of these satellite lineament are: N0°-10° (13%) and N90°-100° (12%). On the hydrographic network, in situ, the most frequent fracture, vein and dike directions are: N90°-100° (12%), N130°-150° (11%), and N50°-60° (10%). The structural domains identified probably correspond to the main corridors and reservoirs of underground flows. The values of the induced permeability are between 0.05 × 10-8 and 3.4 × 10-7 m/s. The permeability induced by satellite lineaments, which is strongly related to high fracturing densities and major water stream is involved in the hydrodynamic functioning of discontinuous aquifers in the study area.
