The dynamic change and effect of rainfall induced groundwater flow

Abstract

This study aims to analyze the groundwater flow changes caused by rainfall and its influence on slope stability. Taking the slope in Dingjiafen, Chuxiong, Yunnan, China as the study area, the study monitored the data of rainfall and drew upon the calculation module of ArcGIS to predict the change of the groundwater flow and water level fluctuation in the soil. In this way, the visual simulation of groundwater flow distribution of the slope was realized; and the influence of groundwater flow distribution caused by rainfall seepage on the slope’s stability was also analyzed. The results indicate that: (1) the rainfall recharge rate is affected by the thickness of the soil layer, the slope, the rainfall intensity, and the initial water content of the soil; (2) the seepage flow of rainfall in per unit time is positively correlated with the soil layer thickness of the slope; (3) the groundwater is repeatedly raised, maintained, and dissipated by periodic rainfall which destroys the structure of the soil; and (4) the rainfall reduces the cohesion and internal friction angle of the soil resulting in the “muddy water softening effect” in the weak zone.