Study On Ecology-Oriented Groundwater Resource Assessment In Arid Area

In arid areas, the limited water resources, groundwater resources for the maintenance and development of human life and ecological environment has an important role. Southern edge of Junggar Basin in Xinjiang is located in the Tianshan Mountains in northwest China,a typical arid, dry climate, scarce rainfall, strong evaporation, uneven temporal and spatial distribution, lack of surface water, groundwater is the main supply of local water sources. Arid and semi-arid ecological environment is fragile, groundwater resources are largely dependent. Groundwater is not only resources, but also a very important ecological function.Water shortage and the fragile ecological environment has become a bottleneck restricting the development of the region.Studies by the complement of groundwater discharge characteristics and distribution of diameter, and surface characteristics of the ecological environment, caused by groundwater surface of environmental effects, analysis of the ecological environment in arid regions groundwater features to determine the impact of eco-environmental effects of groundwater in arid areas The main factor is the groundwater level, the study area obtained optimal ecological water depth of 3 to 5 meters, for the evaluation of groundwater resources and ecological constraints.In considering the groundwater resources in arid and semi arid areas and ecological attributes of the property, based on the sustainable use of groundwater and the ecological environment in harmony as the goal, through the establishment of hydrogeological conceptual model, lumped parameter models and distributed parameter model based on three models groundwater environment changes in ecological constraints for regional groundwater resource evaluation model, evaluation of groundwater.Parameter model by focusing on the evaluation showed that the total recharge in the study area is 340274.05×104m3/a, the total discharge amount of 354902.61×104m3/a, calculation of groundwater allowable withdrawal is 257714.94×104m3/a. Through the numerical simulation of groundwater flow model calibration and improvement, according to status of groundwater development in the region and ecological constraints, the design development of groundwater of different programs, simulation and prediction of groundwater system is the state after excitation, hydrodynamic field and so on.Under the programⅡ, in considering the constraints of geo-ecological environment, based on the exploitation of the layout by adjusting the calculated volume of groundwater allowable withdrawal 23.92×108m3/a, and basically in balance. ProgramⅢ, through the use of water saving measures and improve the canal system utilization factor, so that infiltration and drainage seepage field reduced by nearly half the cases, the adjustment of mining layout, reducing the total groundwater recharge 6.01×108m3/a, groundwater allowable withdrawal was 18.37×108m3/a. The diving program is invalidⅢevaporation win the most, about 2.0×108m3/a, and take full account of groundwater and surface water utilization principles for the best interests of ecological and geological environment.Objective of the study can correctly evaluate the regional groundwater resources, the ecological environment in the region of surface protection and the rational development of groundwater management and protection provides the basis and guarantee.