Modeling Surface Runoff Response to Soil and Water Conservation Measures using QSWAT+ in the Northeastern Highlands of Ethiopia

Watershed management in the developing world rarely includes detailed hydrological components. However, the hydrological cycle has many interconnected components, such as precipitation, evapotranspiration, surface runoff, infiltration, and groundwater flow. A common challenge in hydrological studies is estimating runoff in watersheds where precipitation records exist, but runoff data is unavailable. Thus, there has been a lack of long-term quantitative assessment. The QSWAT+ model was used to analyze hydrologic phenomena and assess how watershed changes impact the hydrological cycle. 17 years of meteorological input data were used to run the QSWAT+ and model hydrological responses to soil and water conservation measures on paired micro-watersheds, called Amanuel and Degnu, in the northeastern highlands of Ethiopia. The results indicate that QSWAT+ successfully models surface runoff at a daily time step, achieving Nash-Sutcliffe Efficiency (NSE) values of 0.826 and 0.945, and Coefficient of Determination (R²) values of 0.944 and 0.741 for Amanuel and Degnu, respectively. The model results can help policymakers, land-use planners, and water resource managers effectively allocate water resources and implement sustainable watershed management practices based on flow conditions.