Research On Rainfall Recharge In Desert Plateau Of Erdos Basin

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. So it is very important to research the mechanism of precipitation deeply and calculate the supply amount of groundwater precisely.The vadose zone is the joint between rainfall and groundwater. Directed by dynamics of soil water and aimed to quantify the supply quantity of groundwater, this paper acquires the hydrulic parameters of different lithology in the field test area and analyzes the effect factors of precipitation. Farther more, on the base of rainfall and lithologic character, the author calculate the supply quantity of groundwater using the hydraulic parameters from field research. The results show as follows:(1) The water migrating law of vadose zone is analyzed in area of field testThe 29,610 negative pressure data are acquired by field test, on the basis of this, following recognitions are got: when there exists sandy zone in upper vadose zone, the total water potential is big-end-up; when there is sandrock or clay-zone in upper vadose zone, the ZFP is formed approximate at 0.4m and 1.5m under surface separately.(2) Hydrulic parameters for different lithologic character are determined in the area Numerical simulation result shows that the relative error less percent 15 betweencalculation and observation value. Therefore the hydraulic parameters which determined by numerical simulation are credible.(3) Factors that affect transfer quantity from precipitation to groundwater are discussedRecharge quantity from precipitation to groundwater is determined mainly by the rainfall, structure and water content of vadose zone and groundwater burial depth. Numerical simulation based on hydraulic parameters and meteorological data in field test area conformed the following opinions: ?the more rainfall, the more supply quantity that groundwater gain, for instance, when yearly precipitation is 376...