Geoelectric Delineation of Aquifer Units in Bayelsa State, Nigeria: A Review of Case Studies and Groundwater Management Implication

Groundwater is Bayelsa State's principal dependable water source, but development is complicated by heterogeneous Niger Delta sediments, shallow water tables, flooding, contamination and possible saline influence.

This structured narrative review synthesises geoelectric aquifer studies published from 2010 to 2026 and evaluates their management implications.

Publications were identified, screened and compared by survey design, curve type, layer sequence, aquifer resistivity, depth, thickness, hydraulic properties, protective capacity, vulnerability and validation.

Evidence is concentrated in Yenagoa, Ogbia, Otuoke, Opolo-Epie and Elebele and consistently indicates multilayer aquifers of fine- to coarse-grained sand separated locally by discontinuous clay, silty-clay and sandy-clay units.

Schlumberger vertical electrical sounding has delineated productive horizons, guided drilling depth, assessed overburden protection and extended sparse pumping-test information.

Reported parameters vary because of genuine facies changes and differences in electrode spread, sounding density, inversion, classification thresholds and calibration.

Resistivity alone cannot uniquely distinguish clay, freshwater sand, saline groundwater or contamination; borehole logs, pumping tests, hydrochemistry and microbiological analyses remain essential.

The review recommends locally calibrated interpretation, integrated VES-ERT investigations, systematic monitoring and abstraction control, a unified state groundwater database, wider coastal coverage and regional aquifer correlation to support sustainable development and protection.