Study On Water Environmental Carrying Capacity Of Yulin City

Water is commonly considered as not only a strategically basic resource that supported the coordinated and healthily development of regional social economy, but also a controlled factor that kept the sustainable benign circulation of the regional eco-environment system. In recent years, Yulin city makes use of region advantage, developing the heavy chemical industry strongly and constructing the energy industry base actively. The area's industrial structure is simple, the economy growth mode is extensive, the three-discard exhausting and increment of the population make the Yulin's water pollution and ecosystem environment worsen, threatening the city's development increasingly and seriously. Therefore, how to deal with the relationship between water environment and social economy had become the important issue need to be solved urgently. This dissertation had studied on water environment carrying capacity (simplified as WECC) in Yulin city, which could offer scientific basis to the implementation of the sustainable development strategy.Based on water resource and water environment, this paper studies the WECC of Yulin city, in order to assort with the development of environment and economy. Firstly the paper builds the index system of WECC by means of the carrying object, starting from the carrying media of WECC. Secondly the paper builds the Yulin's ecological and environmental water demand, starting from the concept of the ecological and environmental water demand of city. Finally it builds the WECC model by system dynamics to study the WECC of Yulin city, the study has some realistic value. The main achievements obtained are as follows:(1)On the basis of analyzing the WECC s connotation, characteristic, carrying mechanism, index system etc. combining the fact of Yulin, the paper builds the index system of WECC and calculates the weight of each index and subsystem by the method AHP.(2)On the basis of discussing the city's ecological and environmental water demand, it builds the model of Yulin's ecological and environmental water demand. It includes rivers ecological and environmental water demand—Wuding river, Tuwei river and Kuye river, Hongjiannao's ecological and environmental water demand and city's ecological and environmental water demand.(3)Because of the influence of Yuxi River, the paper calculates the river's empower sewage-hold capacity.(4) The paper analyzes the relation of main factor and coupling relation of each system by system dynamics, on that base it builds the WECC model of system dynamics. After the test of effectiveness, the paper designs the 10 different schemes, such as economizing water, fathering pollution etc. it analyzes the WECC of each schemes by simulating. Finally it confirms the optimization scheme.(5) Finally, operable and specific measures to advance the WECC of Yulin were put forward, aiming at optimization scheme.