The Use Of A Digital Resistivity Tool For Investigating Variations In Depths To Aquifer At Amachree Area In Buguma, Rivers State

Abstract

This study investigates the subsurface hydrogeological conditions of Buguma in the Niger Delta, with a focus on identifying zones of iron-rich water and saltwater intrusion that threaten groundwater quality. Electrical Resistivity Tomography (ERT) was applied to characterize the subsurface and delineate conductive zones that reflect different contamination sources. The resistivity tomogram reveals a shallow conductive layer interpreted as an iron-water formation zone, likely resulting from the mobilization of ferruginous minerals under changing redox conditions. This zone shows a progressive downward extension, indicating infiltration into deeper aquifer units. At greater depths, a distinct low-resistivity zone was identified, consistent with saltwater intrusion extending laterally and vertically through the subsurface. The continuous conductive signature from shallow to deep levels suggests a vulnerable aquifer system with direct hydraulic connectivity, allowing contaminant mixing and reduced freshwater quality. The geological framework, dominated by unconsolidated sands and interbedded clays of the Benin Formation, enhances permeability and further supports the downward and lateral migration of contaminants. The results highlight a dual contamination scenario: ferruginous enrichment at shallow depths and saline intrusion at greater depths. This poses a serious threat to sustainable groundwater use in Buguma. Immediate mitigation measures such as controlled abstraction, monitoring, and aquifer protection are recommended to preserve groundwater resources.