Groundwater Investigation Using Geoelectrical Method: A Case Study of the Western Region of Cameroon

Abstract

A geoelectrical survey using the electrical resistivity method was carried out in some villages in the western region of Cameroon to investigate the sub-surface layers and evaluate the characteristics of aquifers. The direct current electrical resistivity method was utilized for the present study. Applying the Schlumberger array, a total of twenty four (24) Vertical Electrical Soundings (VES) were conducted. Quantitative and qualitative interpretations of data were carried out to determine the nature and thickness of the aquifer zone combined with existing litho-logs aided correlation of geoelectric sections to litho-logs. Four to five geoelectric layers were delineated from the survey area. The first layer which is the topsoil has resistivity values ranging from 6 -949 Ωm and the thickness is between 0.2 -4.2 m. The second layer which is made up of clay and laterite has resistivity values ranging between 9 -1862 Ωm and thickness range from 1.0 -16.4 m. The third and fourth geoelectric layers are made up of clay and granite/basalts with thickness varying from 2.2 -39.5 m which corresponds to an aquifer horizon. Resistivity values of the aquifer ranges from 10 to 70,506 Ωm. The resistivity map drawn from these measurements shows the presence of a low resistivity zone which indicates the reflection in the direction of ground water from northeast to southwest with the recharge concentrated to the south of the study area. This study has revealed for this area, an average depth of the aquifer of 32 m with the average thickness of the aquifer being 22 m. The geoelectric sections of some VES stations demarcated corroborate very well with the geological description of the area.

Assessment of Hydrogeoelectrical Characteristics of Crystalline Aquifers and Groundwaters Quality in Adamawa Plateau: Case of Mbakaou (Adamawa - Cameroon)

“…The different observations made show that the shape of a VES curve does not depend essentially on the lithological nature, but on the structure of the ground (thickness and number of layers, degree of alteration and presence or absence of fractures). This observation is consistent with the observations of many authors [23,24,29]; both in the basement area and in the sedimentary area. In addition to these two main factors, there is the topography which, according to [30], is the main factor which would influence the shape of the VES curves, especially within a terrain whose lithological nature is homogeneous.…”

“…The frequency and length of fractures in these granitoids constitute the vulnerability points in which water infiltrations occur, and then favour the productivity of the aquifers in the area. The curves shape obtained are similar to the anomalies identified in volcanic and cristalline area in Cameroon [23,24] and on the basement area made of granitoï ds in Ivory Coast [25][26][27] and Nigeria [28]. This suggested that shape of the curves is influenced by the topography and the structure of the field [24].…”

Morpho-Structural Mapping Constraints from Geophysical and Test Pit Investigations: Case Study of the Bomkoul Locality in Douala Sedimentary Basin, Cameroon, Central Africa

“…The fifth studied layer located between 15 and 19 m depth shows a significant variation of the resistivity (Figure 3(f)) throughout the study area which reflects the presence of clay and sandy clays. Keleko et al; reveal in west-cameroon four to five electric layers which corroborate with the present study. The difference between the both results situated on the variation of resistivities values is due to the fact that the present is made in the sedimentary zone which is not the case for their study.…”

“…Resistivity is the reciprocal electrical current. In most porous rock systems, ionic conduction by interstitial fluids and surface conduction at the interface between solid rock matrices and electrolytic solution are responsible for a major part of the electric current flowing through a formation (Keleko et al, 2013). Electrical Journal of Geoscience and Environment Protection This method involves the supply of direct current into the grown through a pair of current electrodes and the measurement of the resulting potential through another pair of electrodes called potential electrodes.…”

Assessment of groundwater quality in Bamenda–Cameroon for suitable applications

“…The study area is characterized by fractured phreatic aquiferous formations found within the hard rock system, and the aquifer types are defined as being superimposed or isolated [15]. The weathered basement (regolith) and alkali-rich fluvial sediments constitute the aquiferous materials in the area.…”