Contribution of vertical electrical soundings, Landsat 8 and SRTM images to the comparative study of the hydrogeological characteristics of the Foto, Keleng and Foreké areas, West Cameroon

The study area is located in the town of Dschang, West-Cameroon, on the southern flank of the Bambouto Mountains. The acute shortage of drinking water supply points due to lack of structural knowledge on existing aquifers. The present work allows the establishment of a hydrogeological map of the study area. The data from the vertical electrical soundings carried out on 64 points, show 12 electrical anomalies: A, H, K, Q, AK, HA, HK, HQ, KQ, KA, KH and Q; divided into two domains: a resistive domain with resistivities between 2892.63 and 27 323.56 Ω m and a conductive domain with resistivities between 0.43 and 2892.63 Ω m. The conductive domain is more represented in the basaltic zone while the most resistant domain is represented by the gneissic and the granitic zones. Hydraulic conductivity in the study area ranges from 0.004 to 44.852 m/day, porosity from 0.192% to 42.615%, longitudinal conductance from 0.001 to 1.101 Ω(−1) and transmissivity values from 0.019 to 504.023 m(2)/day. The area includes two types of aquifers; saprolite aquifer from 1.6 to 16.26 m with a roof varying between 1.5 and 16 m and aquifers on thick fractures from 16.26 to 38.34 m with a thickness varying between 16 and 36 m. The major and minor fracturing directions are respectively N 60° to N 70° E and N 0° to N 30° E. According to the hydrogeological potentials, Foto which is made up of basaltic formation is very favourable, Foreké on granitic formation is moderately favourable and Keleng on gneissic formation is not very favourable.