Abstract: In this work, we conduct a laboratory experiment to simulate continuous rainfall based on four designed soil tanks to clarify the interaction effects of different rainfall intensities, soil layer thickness distribution, and soil base permeability on runoff generation and sediment erosion on hillslopes. The results show that the surface runoff rate takes an increasing trend with significant fluctuations during continuous rainfall, and the average erosion rate shows a trend of increasing first and then decreasing. The surface runoff rate is influenced mainly by rainfall intensity, with a variance contribution rate of 88.85%; the erosion rate is affected primarily by rainfall intensity and its interaction with soil layer thickness distribution, with variance contribution rates of 46.13% and 20.64%, respectively. And the interaction between soil layer thickness distribution and soil base permeability also has a certain impact on the erosion rate, with a variance contribution rate of 9.21%. Therefore, besides rainfall intensity, we should consider the factors of soil layer thickness, soil base permeability, and their interactive effects on the runoff and sediment yield process. This study would lay a basis for understanding the mechanisms of runoff generation and sediment erosion on hillslopes under complex underlying conditions.

Key words: rainfall, runoff yield, sediment erosion, soil thickness distribution, soil base permeability, interactive influence