ANALYSIS OF WATER MOVEMENT LAW IN SHALLOW LOESS SLOPE BASED ON IN-SITU MONITORING

Rainfall-induced shallow loess landslide is one of the major geohazards in Loess Plateau. The spatial distribution and variation trend of moisture in slope are important factors leading to slope instability, but there are few section monitoring data based on the above factors. Relying on the loess geological hazards field observation base in Yan'an City, the study selects a typical loess slope to lay out two 5-meter-deep vertical sections for moisture detection, and observes the spatial characteristics of slope moisture during rainfall. The monitoring results indicate that the variation of rainfall-induced soil moisture content is limited to depth and positively correlated with rainfall; The soil moisture content shows periodicity with time and the period gradually lengthens with increasing depth; The slope moisture shows obvious anisotropy in spatial distribution, uneven and periodic vertically, while the water content in slope top, midslope and slope toe generally show a decreasing trend under the influence of rainfall, among which the water content fluctuates the most at the top and foot of slope, with the largest infiltration depth at the slope toe.