Study On The Impact Of Irrigation On Groundwater And Its Ecological Response Of Xiangride Oasis In Qaidum Basin

The changing of environment arosed by water resource development is a usual problem in arid inland basin. With the economic stratagem moving to West China, the pressure of water resources will aggravate and the environment issue will standout more and more seriously in West Chian. The Xiangride oasis exploitation in the southeast of Qaidum is an example. The entironment there is frail. Along with the increase of oasis exploitation range and the impact of global warming on water resources, the maladjustment of water require and supply is becoming worse and worse. The exploitation of soil and water in out-of order arose many entironment problems, such as water reducing, river and lake shrinking, vegetation destroying, land desertification expediting and soil salinization. It is necessary to analyze main problems of soil and water resources and its exploitation in arid areas through developing interrelated eco-hydrologicl models and put forward the proposal and strategy.This paper give a case study of Xiangride oasis in Qaidum basin. We make use of FEFLOW groud water modeling softwater to set up the groundwater simulation model to simulate and forecast the change of water table under different scenarios of irrigation water division from Xiangride River. We evaluate the exploit project of water resources based on the relation between water table and natural vegetation, and the protection aims of natural vegetation. The study shows that, water table and the phreatic discharge belt will change very little when the water division from Xiangride River controlled between 1-1.5 hundred million m~3 . It is indicated that, this amount of water division can hold the ground water burial depth in reason, and ensure ecologicall water demand of vegetations in this area. But if the water division exceed 2 hundred million m~3, the water table will drop 2m or more, and the area of ground water burial depth lessed than 2 meters will run to zero, the phreatic discharge belt will drop between 2-3m, the swamp area will drop and may bring irreversible affect to the vegetation that only rely on groundwater such as Tamarix spp and Loess plateau.