EVALUATION OF AQUIFER PROTECTIVE CAPACITY OF GROUND WATER RESOURCES IN BOGORO LOCAL GOVERNMENT AREA OF BAUCHI STATE, NORTHEASTERN NIGERIA

Abstract

The study focuses on the evaluation of aquifer protective capacity of ground water resources in
Bogoro area. Forty-four (44) Vertical Electrical Soundings (VES) were carried out using the
Schlumberger electrode array configuration, with half-current electrode separation (AB/2) varying
from 1 to 125 m using Allied Ohmega terrameter and its accessories. The curve types obtained
include: A, H, K, QH, HK, KH and HKH types. The geoelectric sections indicate that the
subsurface is characterized into four geoelectric layers namely: topsoil, clayey layer, fractured
basement and fresh basement. The longitudinal conductance (S) values ranged from 0.006383 to
1.295251 mhos; hence, the area is classified into poor (< 0.1mhos), weak (0.1-0.19 mhos),
moderate (0.2-0.69 mhos) and good (> 0.7 mhos) protective capacity. The total transverse
resistance ranges from 259.6 to 24354.6Ω m2 and the electric anisotropy ranges from 0.557592 to
3.069103. The overburden thickness varies from 1.7 to 41.6 m and the map of the overburden
thickness with secondary geoelectric (Dar-Zarrouk) parameters revealed that the delineated areas
have productive aquiferous groundwater potentials. The major aquifer delineated in the area is the
fractured basement and characterized by thick overburden with high value of longitudinal
conductance (S) of moderate to good protective capacity. The aquifers exhibit moderate to
relatively low value of coefficients of electrical anisotropy with high value transverse unit
resistance. This attests to thick aquifer with thick clay materials above the aquifer that act as seal
and high transmissivity’s while areas with poor to weak protective capacity are susceptible to
infiltrating contaminating fluid.