Hydrogeophysical Assessment and Protective Capacity of Groundwater Resources in Kingsley Ozumba Mbadiwe University Ideato and Environs, Southeastern Nigeria

Geoelectrical investigations were carried out to determine the aquifer potentials and protective capacity of Kingsley Ozumba Mbadiwe University Ideato and environs, Imo State, Southeastern Nigeria. A total of twenty-five (25) Vertical Electrical Sounding survey was conducted using the Schlumberger array to evaluate the characteristics of the aquifers in the studied locations. Geoelectric sections derived from the modeling of the sounding data reveal 7 to 9 subsurface layers and characterized by four main sounding curve types-KH-type, HA-type, HK-type and KA-type. The study area is underlain by alternating layers of shale, sand/sandstone and clay. The aquifer is delineated within the sand/sandstone Formation. The aquifer resistivity ranges from 390 to 450000 Ωm, while the aquifer thickness and depth range from 4.7 to 168.6m and 6.5 to 109m respectively. The Dar Zarrouk parameters of longitudinal conductance ranges from 0.000227 to 0.12134 mhos, whereas the transverse resistance ranges from 1833 to 54223904Ωm<sup>2</sup>. The transmissivity in the study area has its highest value of 684.57 m<sup>2</sup>/day at Amaikpa Ogboko and its lowest value of 19.08m<sup>2</sup>/day at Ogume. Overall, the transmissivity of the study area indicates a relatively high to moderate ability of the aquifer to transmit water, with an exception of Ogume. Furthermore, the aquifer potentials of the study area were shown to differ with aquifer size, structure and characteristics and are influenced by the underlying geology generally. The study area has an overall poor aquifer protective capacity. This suggests that the aquifer is very susceptible to surface contaminants and the groundwater is at risk of pollution. Proper environmental and waste monitoring management is therefore strongly suggested in the study area to protect the groundwater resources.