The aim of the study is to estimate the hydraulic characteristics of the aquifer units based on geostatistical parameters from surface geophysics. A total of seventeen (17) Vertical Electrical Sounding data were acquired to identify groundwater development priority zones in Owerri and some selected towns in Imo State. Five key factors that affect and control groundwater potential and vulnerability were utilized in the development of the geostatistical models which are groundwater potential index (GWPI), groundwater vulnerability index (GWVI) and groundwater development index (GWDI). These factors are depth to water (d), aquifer thickness (h), Mean Resistivity of aquifer (ρm), Transverse unit Resistance (RT) and Protective capacity (PC) of the overburden units of the aquifers. The geostatistical parameters estimated values for the study area are GWPI, 14 to 34, GWVI, 19 to 36 and GWDI 0.48 to 1.60. The rating of the study area based on the geostatistical parameters of GWDI revealed that the study area can be classified into six groundwater development priority zones: excellent (GWDI ≥ 1.60), very high (1. 60 < GWDI ≥ 1.28), high ( 1.28 < GWDI ≥ 0.96), intermediate ( 0.96 < GWDI ≥ 0.64), low ( 0.64 < GWDI ≥ 0. 32), very low (0. 32 < GWDI ≥ 0.10), negligible (GWDI < 0. 10) designations. The geostatistical parameters would help to reduce the additional expenditures of carrying out pumping tests and offer an alternative approach for estimating hydraulic parameters, as it would give the estimation of the yield and quality/protective capacity of a prospective borehole in the area.

Keywords : Groundwater Potential; Groundwater Vulnerability; Groundwater Development; Transmissivity and Hydraulic Conductivity.