Geophysical mapping of buried river channels and other shallow structures recharging major aquifers in the lake Nakuru basin, Kenya rift: case study from Kabatini aquifer.

Abstract

The project covered the geophysical mapping of buried river channels and other shallow structures recharging major aquifers in the upper Nakuru basin of Kenya rift and in particular the Kabatini area. The project aimed at unveiling scientific knowledge of the subsurface geology using resistivity and magnetic geophysical methods. It also aims at solving water shortages and improvement of livelihood of the people of Nakuru and its neighbor hood through proper and more precise geophysical ground water exploration methods. The ultimate goal of the report is to provide guidance to policy makers in decision making especially for ground water extraction in Kabatini aquifer. Geology and hydrogeology of the area have been discussed in the report. The methods used in the research and the expected outputs have also been mentioned in the report. These field methods include vertical electrical sounding, electrical resistivity tomography and magnetic survey. Data processing was done using Earth imager software, RES2DINV, and Euler. The findings of the research ascertain that Kabatini area has underground river channel that flows in the north – south direction. The research also shows that the area has some shallow structures which contain low resistivity materials in different locations. It has also been ascertained that the thickness of kabatini aquifer is more than 150 m.