Research on the Features of Rainfall Regime and Its Influence on Surface Runoff and Soil Erosion in the Small Watershed, the Lower Yellow River

Rainfall has a significant impact on surface runoff and erosion in a watershed, and there is a lack of information about the features of rainfall regimes and how they affect runoff and soil erosion. In the paper, based on 59 rainfall events from 2021 to 2022 in the lower Yellow River Culai Mountain sub-watershed, various statistical analysis methods were used to preliminarily explore the rainfall regime features and their influence on surface runoff and soil erosion. The results showed that the rainfall in the watershed was divided into three regimes: Rainfall Regime I had the highest frequency of occurrence, reaching 74.58%, and Rainfall Regime III was the main power source for surface runoff and soil erosion. The paper filtered out three indicators (P, I, and I30) to analyze the degree of influence of rainfall features on surface runoff and erosion, and the results show that precipitation is the main influencing factor affecting the variation in surface runoff, and the maximum 30 min rainfall intensity is the main factor impacting the variation in sediment yield. The results can provide a theoretical basis for soil conservation, hydrological forecasting, and non-point source pollution management.