An Evaluation of the Groundwater Potential and Its Implications on Climate: Case Study of Ilorin and Its Adjoining Areas, Central Nigeria

Groundwater Potential and Implications on Climate

Abstract

Borehole lithologic logs, Schlumberger Vertical Electrical Soundings (VES) as well as pumping test data been used to investigate the aquifer parameters of the underground system in Ilorin and adjoining areas. The aim is to ascertain the groundwater potential of the area. The static water levels were control correlated with the depth to basement contour. Five boreholes located at random within the area were pump tested. The aquifer system consists of two major aquifers and the overburden thickness ranges from about 4m to 35m. The yield of the boreholes were determined and found to be between 4325 ltrs/hr- 21600 litrs/hr, transmissivity using Jacob’s analysis range between 18m2/day, the permeability or hydraulic conductivity (k) found to be between 1.07 x 10-5 and 6.9 x 10-1. These values are reasonably high and consistent with a large group discharge. Preliminary geochemical analysis shows that although CaCO3- and HCO3- ions occur in higher concentrations compared with the Na+, K+, C1-, Fe+ and S04-- but are still relatively lower than expected values from WHO standard. Generally, the water is of basement type with low storativity and transit time. The yield and depths to basement have been correlated, the correlation coefficient is 0.10. The correlation coefficient of the yield with static water level is 0.2. The two correlation coefficients are low which show a weak relationship. Climate change becomes of ever greater concern and although this issue is getting a great deal of attention, its effects on groundwater is still underexposed. By combining the yield and static water level correlation (0.0), with yield and depth to basement correlation (0.4) the study introduces an integrated perspective that has not previously been documented for this area. The results generate new understanding that can support groundwater resource development and management.