Contribution of satellite imagery to the mapping of potentially water-bearing fracture networks in the commune of tanghin dassouri (central Burkina Faso)

The groundwater resources of crystalline bedrock regions are primarily located within lithostructural discontinuities. While traditional methods of photo-interpretation of satellite imagery are widely employed, they are often constrained by factors such as cloud cover, dense vegetation, and the subjectivity of the interpreter. To mitigate these biases, an automated approach employing the PCI LINE module of PCI Geomatica has been adopted to extract lineaments from Landsat-7 ETM+ imagery, aiming to enhance the reliability of fracture network mapping. The study area, which encompasses the municipality of Tanghin Dassouri, is situated in the central region of Burkina Faso and is dominated by granitoids. It is traversed by a complex network of tectonic structures (faults and shear zones) that may facilitate the presence of groundwater reservoirs. The automated extraction of lineaments has identified a total of 427 fractures, with lengths ranging from 16 meters to 4814 meters, and has revealed three primary directional classes: NW-SE, N-E, and E-W, corresponding to major orogenic phases. These findings were validated by electrical resistivity profiles, which confirmed the presence of conductive structures interpreted as shear zones, likely to contain groundwater. The results of this study indicate that remote sensing, when combined with automated lineament extraction and field verification, is an effective tool for identifying aquifer fractures and optimizing the location of high-yield boreholes in crystalline areas. The integration of these techniques can significantly improve groundwater resource management strategies in the Tanghin Dassouri region and beyond.