Abstract
The inhabitants of Akure Metropolis, south-western Nigeria, depend solely on groundwater for their domestic, industrial and irrigation purposes. There is a need to delineate recharge and discharge areas for assessment and management of groundwater in these areas. One hundred and ninety (190) dug wells were selected for this assessment. Elevation and water table data aided accurate delineation of recharge, discharge and groundwater divide areas. Thirty-six wells representative of recharge and discharge areas were subjected to pollution assessment [DRASTIC, water quality index (WQI) and runoff potential]. The results revealed that the recharge areas have higher pollution potential and runoff amount than the discharge areas. This implied that groundwater sourced from recharge areas was more pollution prone than that sourced from discharge areas. WQI results revealed that the waters from recharge and discharge areas fall within excellent, good, poor, and unsuitable quality categories. Hydrogeochemical results revealed that concentrations of cations and anions are in order of Ca2+ > Mg2+ > K+ > Na+ and HCO3− > Cl− > SO42− with a predominant Ca–HCO3 facies typifying water from a basement complex environment. Gibbs plot and chloro-alkaline index affirmed the rock dominance and existence of imprints of ion-exchange processes influencing the groundwater quality. Intense weathering activities aided with long resident time spent by the water in the voids of the aquifer media are characteristic in this terrain. Recharge of precipitating water through infiltration into the weathered basement aquifers is a pointer to the greater yield of water in the wells. The possibility that precipitation-weathering process has led to the increase in concentrations of all ionic species and possible pollution of the groundwaters from the recharge and discharge areas cannot be ruled out at all.
Highlights
It has been projected that by the year 2030, the world population will have geometrically risen to 8.5 billion, of which 60% of this population will reside in urban areas (UNDESAPD 2015)
The recharge areas are designated as R1–R6, while the discharge areas are designated as D1–D6 (Fig. 3)
The topographical highs areas were regarded as the recharge areas, while the relatively plains/lowland areas with shallowest water table were regarded as the discharge areas
Summary
It has been projected that by the year 2030, the world population will have geometrically risen to 8.5 billion, of which 60% of this population will reside in urban areas (UNDESAPD 2015). Marine Science and Technology, The Federal University of Technology, Akure, Nigeria residential areas, etc.) with its consequential effects. There is high demand for water from these increasing urban populace. This is due to their economic activities and commercial enterprises (MacDonald et al 2005), and total reliance on groundwater for varied purposes. This high demand has been sourced from several hand-dug wells and borehole systems which were mostly or sometimes ill-designed, ill-constructed and non-maintained water systems leading to groundwater pollution and groundwater scarcity in recharge and discharge areas (Ocheri 2006; Ocheri and Mile 2010). Several works have attributed the increased records of groundwater contamination and pollution in the urban cities to several urban human activities
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
