The impacts of climate change on hydrological processes of Gilgel Gibe catchment, southwest Ethiopia

for the streamflow (m3/s), �O is the mean of observed streamflow for the entire evaluation time period (m3/s), and �P is the mean of model predicted stream flow for the entire evaluation time period (m3/s), and n is the total number of observations. The propagation of uncertainties in model outputs in SUFI-2, expressed as the 95% proba- bility distribution, calculated by the 2.5% and 97.5% levels of the cumulative distributions of output variable is considered as 95PPU [49]. P-factor and R-factor statistics are considered quantifying, the fit between the result expressed as 95PPU and observation. P-factor, the per- centage of observations covered by the 95PPU varies from 0 to 1 with the ideal value of 1 while for R-factor, the thickness of the 95PPU optimal value is around 1 3. Results and discussion 3.1 Hydrological model performance 3.1.1 Sensitivity analysis, calibration and validation. Sensitivity analysis for the simu- lated streamflow was performed using a monthly observed flow to identify the most sensitive parameter with strong influence on model outputs. Initially, parameters related to surface run- off, groundwater, geomorphology, evaporation and soil water were considered and 9 parame- ters were identified as the most sensitive parameters for calibration. The given ranks are shown in Table 2. The calibration was carried outfitting the model to the streamflow record of Fig 9. Gilgel Gibe catchment river discharge gauging stations. https://doi.org/10.1371/journal.pone.0287314.g009 PLOS ONE

The impacts of climate change on hydrological processes of gilgel gibe catchment PLOS ONE | https://doi.org/10.1371/journal.pone.0287314 June 28, 2023 13 / 28