Study on the Influence of Rainfall Intensity on the Response of Shallow Soil Moisture to Rainfall in Loess High-Fill Slope

Abstract

Rainfall-induced soil moisture dynamic is a key factor that can trigger slope failures and geological disasters on the Loess Plateau. According to long-term, multi-point, and multi-depth on-site monitoring, this study conducts time series analysis to explore the response of soil moisture to rainfall events in loess high-fill slope and the influence of topographic conditions and rainfall intensity on soil moisture dynamics. The findings reveal that topographic conditions significantly influence soil moisture variability. The coefficient of variation (CV) follows a decreasing order as slope surface > slope step > flat terrain. The spatial variability of soil moisture has a negative correlation with depth in the vertical direction. Besides, under similar rainfall amounts, higher rainfall intensity can reduce the optimal lag time by about 50% at all positions except the slope step. The findings of this study can provide valuable insights into the soil moisture dynamics on high-fill slopes and offer a scientific basis for optimizing the soil-water relationship