DYNAMIC CHANGES OF SOIL MOISTURE IN HILLY AND GULLY REGIONS OF LOESS PLATEAU

The interflow is extremely difficult come into being in Loess Plateau, and our group bring the gully control and land reclamation projects into force, the interflow has been found. In order to study interflow in gully control and land reclamation projects, TR1ME - TDR sensor has been used to monitoring soil moisture changes with depth and time in Nanni-wan, Yan'an, to analysis the dynamic change of soil moisture. The results show that with the height decrease the soil moisture increases as the same depth of soil layer; soil moisture content in hillside slope toe is higher than that which are on the hillside; as well as, the cultivated land has highest and more stable soil moisture content; soil moisture changes over time for seasonal precipitation variability. And there are some conclusions: 1. With the elevation higher the soil moisture content is lower, on the contrary, the elevation lower the soil moisture content higher; 2. soil moisture from up to down in the vertical direction : the soil moisture content decreases, and then increases, is different from the existing growth and reduce type; 3. soil moisture content changing in the time scale is depending on seasonal rainfall and the local crop planting situation; 4. the interflow may exists in this region which inferred with soil moisture variation tendency at 40 to 60 cm depth. This article as a preliminary research result of gully control and land reclamation on soil moisture in hilly and gully regions of Loess Plateau.