Study On The Evaluation Of Hydro-environment Value Loss And Ecological Demand In The Chuanhu Lake In Changchun City

The demand for water has been increasing with the rapid development of Changchun's total industrial and agricultural output, city scale and population in recent years, meanwhile the development of the city construction also brings serious pollution problems. ChuanHu Lake, the main framework of the water system, locating in the northwest of Changchun, serves the function of flood control, drainage, irrigation, farming and landscape. However, with the expansion of industry, commercial and residential land, the water body is now being occupied and invaded,the original ecological environment is seriously damaged, the condition of the watercourse and ecological environmental problems of the costal area is more obvious, this seriously affected the city image and costal residents'daily life, destroyed the rivers ecological landscape, restricted the construction of northwest water system and the exploitation of the costal land.This paper is based on the participation of the project"Research on the Effect of Pollution Control and Ecological Restoration in ChangChun ChuanHu Artifical Wetland"proposed by Bureau of ChangChun Scientific Techniques. In light of data collection, field investigation, analysis of sample collection and testing, this paper appraised the present water quality, and launched a series of water pollution damage assessment and ecological environment preliminary study on water demand.In order to get a better understanding of the current hydro-environment situation in the study area, the section statistics acquired from ChangChun Environmental Monitoring Center and the field investigation and testing data are combined to give an assessment of the groundwater of YanMing Lake and XinYue reservior in the ChuanHu water system.Referring to the present value of hydro-environment, the quantitative assessment on the loss and calculation method, combining the natural, social and basin status with water prices and local economic and social development level, the water value is calculated. Based on the importance of capacity of the environment in the pollution prevention and control, value of the lake environment capacity is calculated by effectiveness evaluation model. According to the ChuanHu water quality statistics, with the help of L.D James'pollution-loss concentration model, loss rate of pollution under different utilization conditions is calculated, thus the capacity value loss caused by water pollution is also calculated. The researches above show that ChuanHu's pollution has already caused great economic loss.In order to maintain the rationally regional ecological environment, ChuanHu's ecological quantity of water demand is in the process, water balance method is used to measure the minimum ecological environmental water demand, the resulting quantity is 120.054×104m3, to meet the minimum water demand, 120.054×104m3 surface runoff is needed to maintain the existence of ChuanHu water body.Management and protection on ChuanHu water area and its surrounding environment should be enhanced, it's crucial to reconstruct the ChuanHu system.