Article Sidebar
Published:
Feb 17, 2026Keywords:
Article Details
This work is licensed under a Creative Commons Attribution 4.0 International License.
As an open access journal, copyright on Anchor University Journal of Science and Technology (AUJST) is retained by the author(s). Authors grant AUJST a license to publish the article and identify itself as the original publisher. Authors also grant any third party the right to use the article freely as long as its integrity is maintained and its original authors, citation details and publisher are identified.
Main Article Content
Determination of Groundwater Vulnerability to Surface Contamination Using Dar-Zarrouk Parameters Within Olujoda and Environs
Abstract
Electrical resistivity investigation was carried out at Olujoda Environ, Ekiti state, Southwestern Nigeria. The aim of this study is to determine the geoelectrical parameters presenting the lithological units and depth to the shallow aquifer, and also to calculate the Dar-zarrouk parameters so as to delineate the hydraulic characteristics of each aquifer from the surface geophysics. Sixteen (16) VES were conducted using Schlumberger array with a maximum half current electrode (AB/2) of 50m. Data were interpreted using partial curve matching technique and assisted 1-D forward modeling with WINRESIST software. The qualitative interpretation revealed AH curves (ℓ1> ℓ2< ℓ3< ℓ4), KH curves (ρ1 < ρ2 > ρ3 < ρ4), QH curves (ℓ1> ℓ2< ℓ3< ℓ4) and QK curves (ℓ1< ℓ2< ℓ3< ℓ4). The geoelectric section generated from the results of the VES revealed four geo-electric layers; these include lateritic topsoil with resistivity ranging from 58-230Ωm, sand clay formation with resistivity values vary from 38 to 514Ωm, weathered basement with resistivity varying from 54 to 455Ωm and fresh basement with resistivity valued between 115 and 1797Ωm. Overburden thickness ranges from 8 to 17m. The hydraulic characteristics of the aquifer estimated from the geoelectric parameters reveal that the aquifer has protective capacities values between 0.0226 and 0.3054 mhos, transverse resistivity ranges from 54.2927-432.843Ωm2, transmissivity values vary from 8.382 to 136.91m 2/day, reflection coefficient values ranges between 0.270 to 0.472 and hydraulic conductivity ranges from 1.28-9.36 m/day. The results show that the aquifer is characterized by high porosity having weak protective capacities (Fatoba, et al., 2014) of overburden layers indicating that it is highly vulnerable to surface contamination. The area has low to intermediate transmissivity values except for VES 2 with moderate value according to the standard for transmissivity classification by Kransy 1993, and moderate hydraulic conductivity values indicating that the aquifer can transmit water at a rate that will suffice for the need of the community in the study area. This study helps in the determination of the hydraulic properties of the aquifer in the study area and its vulnerability to surface contamination.
