Aquifer productivity and groundwater flow in the Western Dabus River catchment, Ethiopia

Abstract

This study aims to comprehensively characterize aquifer systems and unravel groundwater flow dynamics within the Dabus River catchment of western Ethiopia to support sustainable groundwater management in the region. Geographically, the study area is situated between 9°55’0” N to 10°25’0” N latitude and 34°36’0” E to 35°12’0” E longitude. An integrated methods incorporating lithostratigraphic mapping, structural-lineament analysis, pumping-test data interpretation, and groundwater-contour mapping were conducted. Key parameters such as transmissivity, hydraulic conductivity, and groundwater flow direction were analyzed. The results reveal significant spatial variability in aquifer productivity, primarily controlled by lithology, degree of fracturing, and geomorphology. Three principal hydrogeological units were identified in the region: moderately productive fissured aquifer hosted in Tertiary basalt (mean transmissivity T ≈ 44.3 m² d⁻¹; hydraulic conductivity K ≈ 1.54 m d⁻¹; Borehole yields 2–15 L s⁻¹, low-productivity fissured aquifer hosted in Precambrian basement rocks (mean T ≈ 9.92 m² d⁻¹; K ≈ 0.112 m d⁻¹), and aquitard units composed of Meta-Diorite and Serpentinite with very low permeability (mean T ≈ 0.174 m² d⁻¹; K ≈ 0.0055 m d⁻¹). The fractured volcanic rocks and alluvial deposits show relatively high groundwater potential; however, the less fractured formations reveal aquifer productivity. Groundwater flow patterns of the region are mainly controlled by topography and structural lineaments trending northwest to southeast and Northeast to southwest, with flow directed from the southwestern, and western highlands toward the northeastern lowlands following the topographic gradient. The western-central and northeastern parts of the catchment is characterized by recharge and discharge zones respectively. The results reveal that geology and geological structures principally influence aquifer productivity and groundwater flow in the region. Groundwater flow dynamics in the catchment coincide with surface topography toward the main drainage network. The study provides site-specific insights while offering a transferable methodological framework applicable to similar hydrogeological environments globally. The findings support Sustainable Development Goal (Clean Water and Sanitation) and (Climate Action) and align with the Ethiopian National Policy by providing a structural framework to optimize water resource management.