EVALUATION OF HYDRAULIC PROPERTIES AND WATER TABLE FLUCTUATION OF GBAKO AQUIFER, NIGER STATE, NIGERIA

Abstract

Water table fluctuation of selected hand dug wells, and hydraulic properties were determined. The methods of investigation included water level measurements, laboratory tests and analysis. The results indicated that the water level values for 16 wells under study ranged from 6.30 – 7.10 m (Minimum) and 25.40 – 26.30 m (Maximum) during rainy season, while the average during the dry season was 7.60 – 8.90 m (Minimum) and 27.10 – 28.00 m (Maximum). The depth of the wells investigated were between 11 to 30 m, and diameter of the wells ranges between 0.8 and 1.3 m. The aquifer Hydraulic properties were determined from pumping test (recovery test) method. Results showed that transmissibility magnitude ranged from 7.48 to 26.94 m2/day. The hydraulic conductivity ranged from 1.4 to 8. 2 m/day, while specific yield average was 14.5%. The results showed that the aquifer potential of the wells in the study location is generally low which conform to the general phenomena for basement complex terrain on which Gbako drainage Basin is located. The data and results from this investigation are applicable in assessing and the management of groundwater storage, upward flux, water table configuration as well as groundwater exploration and exploitation. There was no significant differences (P>0.05) in the water level of the representative wells indicating they are located within the same geological formation.