Département des Sciences et Techniques de l'Eau et du Génie de l'Environnement, U.F.R des Sciences de la Terre et des Ressources Minières (STRM), Université Felix Houphouët Boigny de Cocody, 22 B.P. 582 Abidjan 22, Côte d'Ivoire
Prospecting for groundwater resources is a problem in the Donga Department (North-West Benin) to satisfy people's water needs. Remote sensing remains essential for the mapping of water presence indicators, which are linear structures. The present study proposes to map the major fractures of North-West Benin from Landsat-8 OLI images and to use field data to characterize them. The use of spatio-directionnel filtering methods of Sobel and gradient and the techniques of Selective Principal Components Analysis allowed the creation of the major lineaments map. The validation of these last ones was carried out by several field works (geology, hydrogeology, geomorphology and botany). These data were superimposed in a GIS. After treatment, the obtained card counts 745 major fractures. This approach allowed to discriminate three major types of fractures. Fractures marked by vegetation alignments (type A) are the most abundant and occupy 60% of the area of the Donga Department. Fractures related to geological formations (type B) occupy 20% of the area of the study area and correspond to strike-out and shearing structures. The fractures indicated by the rectilinear cornices of lateritic cuirass (type C) correspond to late faults. The study of the directional distribution of outcrop fractures shows that the major directions are N-S (27%) and NE-SO (24%). This map will serve as a background document for future hydrogeological surveys in the region.
The mining industry is a main sector for economic and social development of a country. However, this industry generates many negative impacts on human and biophysical environments. Located south-east of C
This study realized at Bondoukou region in north-eastern of Cote d'Ivoire. It aims to analyze hydrodynamic properties of fissured aquifers with a view to improve drinking water supply at this region. Methodology applied for this study started by mapping of fractures networks from treatment of Landsat 7 satellite images with directional filters. After that, it was established relationship among the parameters of groundwater capture and their relation with fracturing and nature of rock formation. Geostatistical analysis of specific capacity of wells from corrected last step drawdown closed the methodology. Use of remote sensing led to map 5000 fractures responsible of water-bearing-layers inside bedrocks. Productive fractures are met between 30 and 60 meters under the ground with these principals directions: NE-SW, NW-SE and E-W. Great yields are also met at weathering between 15 to 45 meters. Approximately 83, 41% of arrival water occurred in the first 30 meters of the basement. Porphyroid granodiorit produced water more than other rocks formations. Variogram structuring of Log (Q/s) revealed that this hydrodynamic parameter can be considered as a regionalized variable with a range equals to 7,36 km. This is a proof of best connectivity of fractures networks identified. Estimation of specific capacities at the whole studied area was made by kriging. All results obtained through this study contribute to best comprehension of hydrodynamic properties of aquifer at North-east of C