Study On Supergene Ecological Effect And Evaluate Excited By Groundwater Level

The north side of Tianshan is located in the south of the Junggar Basin, it has low precipitation and strong evaporation, its water resources is unevenly distributed in time and space, and its ecological environment is fragile. The area is the most developed region of industry and agriculture in Xinjiang, so the Industrial production, agricultural production, human activities and ecological environment have significant dependence on groundwater. As the urbanization process is speeding up in the region, human exploited and utilized underground water heavily, which have caused the degradation of the eco-environmental problems seriously restrict the sustainable development of the area.This paper lined with ecological environment change caused by groundwater exploitation as the main line, aimed at development and utilization of groundwater resources and the virtuous cycle of the eco-environment. The north side of Tianshan as an example, the author constructed the evaluating index system of supergene eco-environmental effect caused by groundwater exploitation, used the coupling of groundwater flow Numerical Simulation Model and eco-environmental evaluation model and made ArcGIS as the platform, evaluated the present eco-environmental situation and eco-environmental status in 6 different mining schemes of groundwater exploitation in 2020. The prediction and evaluation provide the base of sustainable utilization of water resources and optimized configuration, and eco-environmental coordinated development. The following are the results of the study:1. Through the field investigation of groundwater and eco-environment and the analysis of influent factors of the eco-environment, the author constructed the evaluating index system and evaluating criteria of eco-environmental effect caused by changes of water table in the middle of the northern region in Tianshan.2.Trough the evaluating index system and evaluating criteria, the author fixed evaluating factors weight with AHP method, made ArcGIS as the platform and evaluated eco-environment in 2003 by synthetical index method. The result shows:eco-environmental areas that are good predominantly are in the north of Fukang-Hutubi-150 farms, the piedmont overflow areas and upper region of fine soil plain in northern Manasi-Kuitun-Gu'ertu's farms. The fairly good areas predominantly are around Fukang, Wulumuqi, Hutubi, Shihezi, Kuitun, peripheral foreland Gobi desert, the north of Gu'ertu's farm, lower region of fine soil plain in southern Ganjia Lake-The 129 Farms-Fort Ranch. The region of poor eco-environmental mainly in the desert of northern study area and its fringe zones. The results consistent with the actual situation, indicating that the establishment of evaluating index system is objective and reasonable.3.By the coupling of groundwater flow Numerical Simulation Model (distributed parameter model) and evaluating model of eco-environmental synthetical index, the author evaluated the supergene eco-environmental effect caused by changes of water table in 6 different mining schemes of groundwater exploitation in 2020. The evaluation results show that:(1) Before the implementation of the "500 Project"(cited E to WU), Al program was maintained to mine groundwater to 2020, ecological environment situation will deteriorate markedly, especially in the spill belt of the piedmont plain and the upper part in fine soil plain, the area of good ecological environment has a sharp decline, which indicates that the layout of development and utilization of water resources at this stage is not reasonable, it needs to be optimized. If mining groundwater adopting A2 program to 2020, except the area of poor ecological environment of the northern area of Gu Ertu pasture has somewhat expanded, ecological environment of other regions has improved comparing with Al program. If mining groundwater adopting A3 program to 2020, the area of good ecological environment is significantly increased comparing with A1 program, the area of poor ecological environment is obviously decreased. (2) After the implementation of the "500 Project", mining groundwater follows the B1 program to 2020, the area of good ecological environment is significantly increased, and the area of poor ecological environment is obviously decreased comparing with A3 program. If mining groundwater follows the B2 program to 2020, ecological environment in the circum of Caijia Lake and Xinhu farm and the northwestward of Sawan has obviously improved compared with B1. If mining groundwater follows the B3 program to 2020, ecological environment has improved compared with B2, especially surrounding the 150 round field. So, it is an urgent need to implement the "500 Project "to realize coordinated development of social economic and ecological environment.These research results provide the base of utilization and configuration of water resources, and eco-environmental coordinated development. in the middle of the northern region in Tianshan, and have certain reference values of the exploitation and utilization of water resources and eco-environmental protection in arid areas.