Rainfall erosivity and flooding risk assessment in different climate zones of Iran

Abstract

Abstract Rainfall is a major contributor to soil erosion, which its erosive force is measured by rainfall erosivity. This takes into account the amount and intensity of rainfall and is commonly expressed as the R-factor in RUSLE model. The goal of this study is to evaluate rainfall erosivity in Iran using available data sets. Data have been collected from 2,241,924 precipitation grid points in Iran at 1 km resolution. Thirty years precipitation time series ranged from 1991 to 2020. The mean precipitation values varied between 111.46 (BWh) to 1404.15 (Csa) mm. The mean R-factor ranged from 72.66 (BWk) to 3300.71 (Cfa) MJ mm ha−1 h−1 yr−1. The mean erosivity density varied between 0.33 (Dsa) and 2.35 (Cfa) MJ ha−1 h−1. It was exhibited that the arid BSh, and BSk climate zones focused mainly in the northeast, northwest, west and southwest of the country with total 8.88% of the study area exposed from extreme low to low flooding risk. The arid BWh and BWk climate zones with 86.46% of the surface area in the center of Iran, east, south, and some scattered parts in southwest and west of the country exposed from medium high to extreme high flooding risk.