The Simulation And Analysis On Evaporation-dynamic Of Groundwater In Arid Zone Riverside

One third of world lands are located in arid and semi-arid areas, and nearly half of the countries in the world are obsessed with the drought and water shortage problems. Besides China, the drought and water shortage problems seem like outstanding in the Northwest Region.The Ejina Basin which is located at the Lower Reaches of the Heihe River is?the typical Inland River Basin in Arid Regions and fragile ecological environment Regions. Because the Ejina Basin is located in Hinterland of the Northwestern China, and it is belong to continental monsoon climate area, which is rare precipitation and strong evaporation.? So most of the groundwater is lost invalidly by the evapotranspiration. But the groundwater is the recharge sources for maintaining the Ejin oasis,producting and living by people in the lower reaches of Heihe River. So maintaining the Ejin oasis at the Lower Reaches of the Heihe River and the local social and economic development are obsessed with the most of the evapotranspiration loss.?The groundwater in lower Heihe River region is recharged by the seasonal leakage of the Heihe. In recent decades, as the area of Zhangye Oasis in the middle reaches of the expansion, overgrazing and water consumption increasing every year make the upper and middle reaching downstream of the vent water decrease, and result in the lack of water downstream, shrinking oasis, lakes dried up, vegetation degradation and desertification and a series of ecological and environmental problems.Therefore, under the typical climate characteristics of the Rare precipitation, strong evaporation at the Lower Reaches of the Heihe River and the typical relationship between the recharge and discharge, this paper points out the question that The simulation and analysis on evaporation-dynamic of groundwater in Arid zone riverside .But this did not take the general conduct of large-scale dynamic simulation of groundwater level, it takes small-scale, micro-dynamics of the groundwater level simulation and analysis for the two typical profiles which are selected in Ejina basin. Firstly, this paper describes the natural geographical of the Ejina Basin systemly on a large scale, hydrogeological conditions, groundwater recharge and discharge conditions and the relationship between groundwater and vegetation. Then according to the natural geographical features, aquifer structure and occurrence of groundwater of the study area, we determine the mathematical model of the study area which is one-dimensional diving flow model including evapotranspiration; and to solve and calculate the steady-model and the transient-model, to get the analytical solutions of the one-dimensional steady-model under the linear and nonlinear evaporation. Finally, simulate the groundwater-dynamic of the typical profile, discuss and analysis the recognition results; obtain the curves of the amplitude versus level with the distance from the river and the amplitude of topography on the impact of water.