Geophysical evaluation of geohydrokinetic properties of aquifer units in parts of Enugu state, Nigeria

Abstract

Vertical electrical sounding employing Schlumberger electrode configuration was carried out in thirty locations across some parts of Enugu state, to investigate the hydrokinetic properties of hydrogeologic units of the study area. The result shows that resistivity and thickness of aquifer ranges from 27.3 to 59,569.0 Ωm and 23.3 to 242.1 m respectively. Permeability and fractional porosity values range from 4,531.254 to 74,006.76 mD and 0.026 to 0.159. AQI having a mean value of 13.5451 μm range from 6.809 to 52.976 μm. FZI and HFU values range from 37.582 to 1,962.074 μm and 18 to 26 respectively. Contour maps were generated from the results to visualize the variations of the hydrokinetic properties across the study area. From the contour maps, the southern part of the study area was identified to be characterized with high AQI, FZI and HFU with the northwestern part and a small proportion along the southwestern part identified as areas with low AQI, FZI and HFU. HFU along the study area was observed to be fractionated into nine distinct properties (HFU 18, HFU 19, HFU 20, HFU 21, HFU 22, HFU 23, HFU 24, HFU 25, and HFU 26) with HFU 19 and HFU 20 dominating the area. The results from the nine hydraulic flow units based on flow zone indicator cut off values (Log FZI>0.25) show that the reservoir quality is very high. HIGHLIGHTS Groundwater repository was characterized using geohydrodynamic properties.; The results revealed the dependency of AQI on tortuosity.; The groundwater repository was classified into nine hydraulic flow units.; The results show very high reservoir quality.; The results revealed variations and interrelations of the parameters.;

Keywords

• aquifer
• hydraulic
• hydrokinetic
• permeability
• tortuosity