Delineation of groundwater potential zones in Logbadjeck, Cameroun: an integrated geophysical and geospatial study approach

Abstract

The locality of Logbadjeck, located in the littoral region of Cameroon, has been investigated using the vertical electrical soundings with a Schlumberger configuration. Eighty vertical electric soundings have been carried out along fourteen profiles oriented in the southwest-northeast direction. The lateral and vertical variations of resistivity in the area were mapping and made it possible to infer the internal structure and determine the presence of aquifers in order to solve the problem of drinking water in the study area. Resistivity maps highlighted the conducting properties of the subsoil. This zone is made up of 3 to 5 layers and the Vertical Electrical Sounding curves obtained were of the KH, K, H, AK and Q types. The resistivity generally varied between 11 Ω.m and 8131 Ω.m and decrease with increasing depth. In addition, areas with discontinuities which can be associated to a fracture, a zone of water infiltration or a very conducting body were also identified and could be potential zones for groundwater prospecting. The very resistive bodies observed in the study area suggest the presence of gneiss. The subsoil of the study area, in turn, highlights the presence of two principal aquifers: shallow aquifers at depths of approximately 6 m and deep aquifers lying between 28 and 56 m of depth. Hydraulic conductivity ranges from 0.1 m/day to 16 m/day while transmissivity ranges from 5 $$m^{2} /day$$ to 600 $$m^{2} /day$$ . The transmissivity results obtained show that the study area is rated low to moderate groundwater potentials. The longitudinal conductance ranging from 0.2 $$\Omega^{ - 1}$$ to 1.24 $$\Omega^{ - 1}$$ enabled the protective capacity of the aquifer to be classified as moderate to good. The estimated aquifer, protective capacity and the various constructed contour maps, will serve as a useful guide for groundwater exploration and development in the study area.