Abstract: To unveil the rainfall infiltration patterns at a loess deep filled site, a monitoring station was established in Yan’an to continuously monitor the soil moisture content within a 28 m depth over 31 months under natural rainfall conditions. The water migration within compacted loess was scrutinized based on rainfall, evaporation, and temperature data. Results indicate that atmospheric influence extends to a depth of 3.5 m. With the change of rainfall and evaporation, soil water content exhibits obvious peaks and troughs and annual trend. At 1.0 m depth, atmospheric influence is more pronounced. Soil moisture content shows slight fluctuations below 29 mm/d daily rainfall, followed by sharp increases beyond this threshold. Greater rainfall intensity and duration lead to deeper water migration and infiltration, with a maximum depth observed between 6.0-7.0 m during the monitoring period.

Key words: loess, deep filled ground, moisture content, rainfall, water migration