ASSESSMENT OF HYDROGEOLOGICAL CONDITIONS IN BASEMENT AQUIFERS OF THE PRECAMBRIAN OBAN MASSIF, SOUTHEASTERN NIGERIA

A combined analysis of lineament length density from radar imagery and surface resistivity data is used to assess the hydrogeological condit ions in the Oban massif, Nigeria. The results show that the data guide d the qualitative and quantitative estimation of some aquifer paramete rs. These include resistivity of the water bearing formations (280-740 Omega m), thickness (5-140 m), limited hydraulic conductivity (8.53-1 3.18 m/day) and transmissivity (410.65-725.88 m(2)/day) data. In addit ion, the lineament length density for the area ranged between less tha n 0.2 to slightly more than 0.4. Site evaluation for the location of p roductive boreholes/wells using a groundwater potential index (GWPI) i ndicates that areas with a GWPI of greater than 35 are consistent with relatively high yield.