Groundwater Recharge Estimation in Relation to Land Use Type and Soil: The Case of Hormat-Golina Sub-Basin, Northern Ethiopia

- Comprehending the spatial variability of groundwater recharge, influenced by factors such as land use, soil texture, topography, groundwater levels, and hydrometeorological parameters, is essential for sustainable groundwater resource development. Thus, this study endeavors to estimate groundwater recharge in the Hormat-Golina sub-basin, northern Ethiopia, employing the WetSpass (Water and Energy Transfer between Soil, Plants, and Atmosphere under quasi-Steady State) hydrological model. The model inputs, consisting of 30m grid size maps and attribute tables, are meticulously prepared, drawing upon expert knowledge and scientific literature. Validation of the model against observed data reveals a robust agreement, with an R2 value of 0.94 and NSE of 0.85 for simulated surface runoff. Analysis of the long-term temporal and spatial average annual rainfall, totaling 828.5 mm, delineates its distribution: 156.4 mm (19%) as surface runoff, 616.7 mm (73%) evaporating through evapotranspiration, and 55.4 mm (8%) contributing to recharge. This recharge volume amounts to 4.2*105 cubic meters (m3) for the Hormat-Golina sub-basin, spanning approximately 698.25 km2, with 83% occurring during the summer season and the remainder during the winter (dry) season. Notably, forested areas with sandy soil exhibit the highest recharge rates