Groundwater prospecting using remote sensing and geoelectrical methods in the North Cameroon (Central Africa) metamorphic formations

Abstract

Remote sensing imagery and geoelectrical surveys used in this study help to evaluate the groundwater potentiality in the metamorphic formations of the North Cameroon. The methodology of the work is then mainly based on the extraction and identification of lineaments or fracture zones which acts as the passageway for groundwater. Manual and automatic extraction technics applied on the Landsat-8 images made it possible to find sixty one (61) lineaments. The main directions of these lineaments are N-S and N22°E (NNE-SSW) and the secondary directions are N10°E, NE-SW, then W-E to N100°E. According to the lineament density map, high density values are located at the centre and at the western part of the study area. The lineament density contrasts show the level of fracturing in the area. This fracturing is also evidenced by the geoelectrical survey. Indeed, results of the electrical resistivity profiling and 2D electrical imaging around or near lineaments, reveal the existence of fractures and shear zones characterized by the conductive discontinuities in the electrical current responses. Usually, the discontinuities sus-evocated above form potential groundwater targets. So, based on the combined results from remote sensing and geoelectrical method, the present study thus demonstrates the effectiveness of using this approach for assessing the availability of potential groundwater zones in the metamorphic formations. However, methods used in this study should be supported by the drill hole methods for the validity of results.