[01] Christopher Chukwudi Ezeh, Department of Geology and Mining, Enugu State University of Science and Technology, Enugu, Nigeria. [02] Austin Chukwuemeka Okonkwo, Department of Geology and Mining, Enugu State University of Science and Technology, Enugu, Nigeria. [03] Emeka Udeze, Anambra State Rural Water and Sanitation Agency (ANARUWASA), Awka, Nigeria.

Spatial distributions of aquifer hydraulic properties were carried out from direct pumping test data in Anambra State, Southeastern Nigeria. The study area lies within longitudes 06° 38^I and 007° 15^IE and latitudes 05°42^I and 006°45^IN within an area extent of about 4844sqkm (1870sqmi), underlain by four main geological formations. Pump testing was carried out in over one hundred (100) locations in the study area. The single-well test approach was used, employing the constant discharge and recovery methods. The Cooper-Jacob’s straight-line method was used to analyze the pump test results. This enabled the computing of the aquifer hydraulic properties. Correlated borehole logs show total depth range of 80meters to 250meters, with lithologic sequence of top sandy clay – medium to coarse grained sand – clay/shale – sand/sandstone, with the medium to coarse grained sand thickly underlying the central part of the study area. Static water level ranges from 100meters to 260meters at the central part and 10meters to 90meters at the adjoining areas. Aquifer transmissivity values range from 5m²/day to 80m²/day, indicating variable transmissivity potentials, while hydraulic conductivity values range from 0.5m/day to 6.0m/day. Various 2D maps of aquifer transmissivity, hydraulic conductivity, static water level, drawdown, aquifer yield, specific capacity, aquifer depth, hydraulic head and storativity were constructed to show their spatial distributions in the study area. These maps could serve as a better exploration model for groundwater production in future.

Aquifer Hydraulic Properties, Pumping Test, Single-well Test, Cooper-Jacob

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