Hydrostratigraphic characterization using geoelectrostratigraphic information and hydraulic flow unit analysis for high-resolution aquifer mapping in heterogeneous systems

• Aquifer behavior within river channels and tributaries in a coastal milieu. • Hydraulic flow units were analyzed using stratigraphic modified Lorenz plots. • Detection of internal variations within a homogeneous aquifer unit. • Validation by correlation of geophysical anomalies with hydrostratigraphic features. Accurate characterization of aquifers requires a comprehensive understanding of groundwater hydraulic properties. Traditional aquifer assessment techniques are usually insufficient in characterizing hydrostratigraphic variability, leading to inaccurate prediction of aquifer flow dynamics. To address these limitations, this work integrated geoelectrical stratigraphy with hydraulic flow unit, flow zone indicator, and stratigraphic modified Lorenz plot strategies, the goal being to enhance the resolution of aquifer characterization along river channels and tributaries in Southern Nigeria. Unlike conventional approaches, the stratigraphic modified Lorenz plot (SMLP) provided a more precise strategy for quantifying permeability distribution within the heterogeneous aquifer system, enabling enhanced prediction of aquifer performance. Furthermore, SMLP delineated flow efficiency across the distinct hydrostratigraphic units. Results indicated the presence of four hydraulic flow units, with individual units exhibiting distinctive transmissivity properties. Computed inclination angles of the four flow units were 34°, 29°, 49°, and 33°, respectively, and these indicated the extent of hydraulic efficiency. Hydraulic flow units 1, 3, and 4 had higher transmissivity and were key conduits for groundwater flow. Hydraulic flow unit 2, on the other hand, had reduced transmissivity, indicating restricted fluid migration. The techniques employed in this study enhanced subsurface characterization and generated a high-resolution and cost-effective technique for delineating high-yield aquifer zones within river channels and tributaries with better accuracy than traditional hydrogeological models. These findings are important for optimizing groundwater resource management in the study area and analogous hydrogeological settings worldwide.