Current and Future Assessment of Soil Erosion in Minab Esteglal Dam Watershed Using RUSLE 3D and Climate Change Scenarios

The purpose of this study was to evaluate soil erosion in the present period and to predict soil erosion potential under the impact of climate change over time horizon of 2030. Daily rainfall data and NCEP data during 1985-2015 were used. The future climate was projected using the second generation earth system model (CanESM2) and downscaled using the SDSM model under RCP2.6, RCP4.5, and RCP8.5 scenarios. Rainfall erosivity (R-factor) was estimated for different scenarios and soil erosion were simulated using RUSLE 3D. Results showed that rainfall increases from 146.7 to 178.61 mm in the future and R-factor increases from 28.7 to 34.33 MJ mm ha-1 y-1, respectively. However, due to increasing rainfall intensity in all scenarios and stations, the amount of rainfall erosivity in the future is more than the baseline period. The amount of soil erosion is estimated 10.16 ton ha-1 y-1 at baseline period. Considering the constant assumption of other variables in the RUSLE 3D model and the increase in future rainfall erosivity, the erosion rate under RCP2.6 scenarios increased to 15%, RCP4.5 to 10% and RCP8.5 to 3%, respectively.. Accordingly, the increase of rainfall increases the rainfall erosivity factor and consequently increases the erosion rate. Therefore, assessing the present and predicting future soil erosion in the Minab Esteglal dam watershed, provides useful information for environmental and soil conservation.