Health Assessment On Coastline Wetland Ecosystem Around The Yangtze River Delta

Ecosystem health and Pressure-State-Response(PSR) framework is applied as research method in this article. According to the characteristics of coastline wetland ecosystem, a set of coastline wetland ecosystem health oriented assessment index system has been designed. Assessments, which aim at Chongming Dongtan, Jiuduansha and Nanhui coastline wetlands, were conducted not only with one single factor but on comprehensive scale as well. In the assessments, index on health state(HSI), pressure(PI) and response(RI) were calculated respectively. Results of this research disclosed the special distribution of health state three wetland areas and the related cause. Meanwhile, suggestions on conservation and sustainable utilization are provided.Following are the detailed results of the research1. Health State Index (HSI) of Dongtan is 0.72, health stated considerable ; HSI of Jiuduansha is 0.79, very close to satisfied health state; HSI of Nanhui is only 0.39, the health state not so satisfied and with initial characteristics of wetland morbidity.2. PI of Dongtan is 0.64, in the safety scale; PI of Jiuduansha is 0.81, with little pressure on ecosystem; PI of Nanhui is 0.40, far more beyond the safety limit.3. As state sanctuaries, RI of Chongming Dongtan and Jiuduansha are 0.79 and 0.74 respectively, which indicated that the governmental conservative consciousness and policy are quite satisfied. While take Nanhui as a comparison, RI is only 0.29, indicating that both the consciousness and the policy on wetland conservation of local government is ineligible.4. The sources of wetland pressure were originated mainly from utilization of the land, in another word, under local circumstance, is inning. While the inning level of Chongming Dongtan and Nanhui are both considerable, the scenery and health state are much better in Chongming Dongtan than in Nanhui, which is caused by the natural and manual alluvial speed.It is considered that, health state is affected both by the pressure of wetland and conservative response of human being. The three wetlands, under different jamming manner, jamming intensity and conservative response, respect three typical ecosystem health states of wetland,Scientific management and conservation of Chongming Dongtan wetland is enhanced under appropriate development, such as substituting extensive mode with intensive mode in economic system, avoiding over-utilization of Non-renewable resources and following sustainable development.Jiuduansha, the last virgin soil of Shanghai, suffers from nearly no jamming because the absence of development. The opportunity costs of keeping the wetland under pure natural health state are economic profits from developing and inning. However, paying these costs is quite valuable as the last natural land of Shanghai could be conserved.Caused by over-development, also with the absence of effective management and protection, coastline wetland in Nanhui is suffering from severe degeneration and poor health state. The seemingly huge economic profits are obtained under the cost of wetland lose. Actually, the rejuvenation of Nanhui wetland is infeasible from the perspective of science and finance.