Estimation of Hydraulic Parameters from Dar-zarrouk Parametersudfor Aquiferous Zone Characterization in Iyesi Axis, Ota, OgunudState Nigeria

摘要

The cost of estimating hydraulic parameters from slug test, pumping test, soil sample analysisudetc is expensive. However, these parameters such as transverse resistance and longitudinaludconductance can be estimated from geophysical parameters which are cost effective, noninvasiveudand inexpensive. In this present study, twenty (20) geoelectric sounding were carriedudout in Iyesi- Jackross axis with the use of ABEM 1000 series terrameter using schlumbergerudarray and AB/2 ranges from 240m to 420m. The result revealed that there are six lithologicaludlayers in the study area namely; topsoil, lateritic clay, clayey sand, kaolitic clay, clayeyudsand (low yield aquifer) and sand (Main aquifer). The aquifer’s depth ranges from 45.1m toud114.7 m with resistivity values ranges from 19.5 Ωm to 850.8 Ωm. Furthermore, transverseudresistance and longitudinal conductance were estimated from geophysical parameters and itudwas observed that longitudinal conductance is low which ranges from 0.0127 Ω−1udto 0.0941udΩud−1ud. Consequently, the aquiferous unit is characterized with high transmissivity and hydraulicudconductivity. Transverse resistance ranges from 12246.00 Ωm2udto 124878.61 Ωm2 and increaseudin transverse resistance that was observed generally indicating high transmissivity and highudyield of the aquiferous units. It is therefore signifies that the study area is characterizedudwith good groundwater potential. Further study can be carried out to estimate the boundaryudof aquifer thickness and the possible intrusion of Basement complex using magnetic technique.