Hydrogeological mapping from Landsat 8, SRTM images, vertical electrical soundings and hydraulic parameters of aquifers: Case study of the South Western part of Baleng Watershed

Abstract

The main aim of this study is to carry out a hydrogeological assessment to reveal suitable sites for the implantation of hydraulic structures like water boreholes. Petrographic studies put into place granitic rocks with numerous biotite in the Northern part of the map and basaltic rocks with phenocryst of olivine in the South. Lineaments extracted from satellite images revealed two major trends of N50–60°E and N70–80°E. A total of sixty-four Vertical Electrical Sounding (VES) data were acquired using Schlumberger configuration array, 2-D sections and hydraulic parameters of aquifers were deduced. The geoelectric sections characterize the subsurface into four geoelectric layers namely: topsoil with (resistivity values lower than 300 Ω m), weathered basement with (resistivity values ranging between 300 and 600 Ω m), fractured basement (resistivity ranging between 600 and 800 Ω m) and a more or less fresh bed rock with resistivity value up to 4000 Ω m. The hydraulic assessment of aquifers revealed a high conductivity value of 34 m/day, porosity of 41% and a high transmissivity of 429 m²/day indicating a highly interconnected fractured basement of the study area. Groundwater potential map revealed Toungang, Lafé and Ndionkou villages as suitable sites for water boreholes implantation with an average aquifers roof depth ranging between 1to 31 m.