Geoelectrical Investigation of Aquifer Systems in Toro and Environs, Northeast Nigeria

Abstract

Aquifers in Toro and the surrounding area of northeastern Nigeria were characterized using fourteen (14) Vertical Electrical Resistivity Sounding (VES). The study's goal is to use Schlumberger configuration to describe the local aquifer system. The study is warranted due to the numerous unsuccessful wells and boreholes in the area. A maximum electrode spacing of 120 meters was used for the vertical electrical sounding (VES). These three-layer earth models (H, Q, and A) were used to derive the sounding curves. The following lithologies were identified in the area: surface soil having resistivity between 91Ωm - 154.21Ωm with thickness of 0.88m - 4.77m; fractured basement having resistivity of 11.52Ωm - 578Ωm with thickness of 4m – to depth infinite; and the fresh basement having resistivity of 1121.21Ωm - 1401Ωm with a thickness of 8m to depth infinite in thickness. The region's groundwater supply potentials were evaluated using the resistivity contrast (FC), transverse resistance (T), and longitudinal conductance (S). The area's groundwater potentials were classified as high to medium, and its aquifer protection capacity was rated as moderate to excellent. The results of the evaluated parameters indicate that the groundwater potential in the region is mainly high to moderate. Bad quality data, in proper expertise, poor drilled-hole development, and erroneous point selection that are very rampant Basement terrains might be the cause of the most failed/aborted wells incidents in the area. Clean water is essential in human for drinking, and its contamination or lack can have serious negative effects on public health, from disease to epidemics.