Dolvan Tchoumgna Kamleu, MSc

Contribution of Remote Sensing and Geoelectricity to the Characterization of Basement Aquifers in Adamawa, Cameroon

D Tchoumgna Kamleu1, J. J. Nguimbous Kouoh2, B. Ngounou Ngatcha3
1Harquail School of Earth Sciences, Laurentian University, Sudbury, Ontario, Canada
 2Mine, Petroleum, Gas and Water Resource Exploration, University of Maroua, Kaele, Far North, Cameroon
3Earth Sciences, Laboratoire Mixte International en Science de l’Eau (LAMISE): University of Ngaoundere, Ngaoundere, Adamawa, Cameroon

Adamawa is called Cameroon's water tower because many of the country's rivers originate from there. Despite this supply, accessibility to drinking water is still an important issue. In the Adamawa, this problem pushes the population of the urban and peri-urban localities of the region to extract underground water resources from the cracked and/or fractured basement. However, the complexity of this basement and the lack of preliminary studies by the companies that install water wells mean that the flows generally have a low exploitation potential. In this study, satellite remote sensing and geoelectricity are an important contribution in determining the characteristic signature of productive saturated zones. Remote sensing can be used to identify the structural lineaments that might case fractures in the basement. Geoelectricity surveys have helped to characterize the deep horizons likely to constitute aquifers. Analysis of the satellite images revealed major lineaments in the following directions N49°E, N60°E, N70°E, N78°E, N108°E and N120°E. The analysis of twenty-six (26) electrical sounding that are calibrated with fourteen (14) geological borehole logs revealed that the ranges of resistivities corresponding to the saturated zone are in the flowing three ranges [528 - 7118 Ω m], [190 - 31818 Ω m] and [108 - 78037 Ω m]; and that the sounding curves have a typology that ends with H or are the more likely to have good flow or production rates. Thus, remote sensing and geoelectricity have provided conceptual models of the aquifers of the subsoil that comprise lateritic formations, alterities and fractured and/or fissured formations. This study was able to identify structural and geoelectric signatures of the saturated zone in the basement aquifers of the region, making it possible to better guide future prospecting or investigations.