Research On The Mechanism Of Water Migration Of Rainfall Infiltration Process In Vadose Zone

Erdos Basin, with abundant mineral resource, is one of the energy bases of china in the 21 century. The Basin is divided into two typical geomorphy by Baiyu Mountain which are loess plateau in the south and desert plateau in the north. In the desert plateau, water shortage is the vital factor to restraint the local economic development because of the scare rainfall, strong evaporation and vulnerable ecological environment. The preliminary research shows that vertical exchange is the chief way of water cycle in the area and the groundwater is mainly recharged by precipitation which takes up 78.5 percent of total supply quantity. Therefore, further study on the mechanism of water migration of rainfall infiltration process in vadose zone in the field is of great significance.This paper was oriented to study the mechanism of water migration of rainfall infiltration process in vadose zone. Based on the soil water dynamics theory, numerical analysis and mathematical statistics methods, research and laboratory simulation experiments were employed to determine soil water of the parameters, to analyze the impact of rainfall infiltration and to reproduce the actual process of the water infiltration under rainfall condition .Following were the results of the research:1. Through laboratory evaporation-infiltration barrel experiments, revealed the changes in rainfall infiltration process, advanced the one-dimensional mathematical model of the unsaturated seepage under rainfall condition. On the basis of laboratory simulation, and illuminated the basic law of unsaturated seepage.2. Adopt hydrus-1D software put up ask explain and account about the one-dimensional mathematical model of the unsaturated seepage under rainfall condition. From the overall perspective of model recognition, this model could simulate the change of process soil moisture content, and the error was around 10percent.3. Discussed the impact of rainfall infiltration factors.â‘ rainfall was intenser , the more conducive to rainfall infiltration and the greater the rate of infiltration and groundwater recharge accessed to the greater volume. For example, if the intensity of rainfall was 3 mm / min, and it lasted 19min, at 94 min when water transported 70cm under the surface,while rainfall intensity for the 6.92 mm / min then transported over 90 cm, and rainfall intensity as 11.7 mm / min, it had been transported over 120 cm. Accessed to the volume of underground water supplies were 4.99 cm, 7.08cm, 15.7cm.â‘¡The bigger of the vadose zone water content was ,the more favorable rainfall infiltration and groundwater received more recharge.