The Research Of Urban Ecosystem Health Assessment In Songyuan City

With the accelerated pace of urbanization, environment pollution and ecology destruction have led to an endangered ecosystem in urban areas, which constrains the development of the city. A healthy urban ecosystem is the foundation of a livable city, so for the environment management policies’implementation, maintenance of a healthy ecosystem is the ultimate goal.Our research efforts focus on the health assessment of the ecosystem in urban planning area of Songyuan city. Through a comprehensive study of the concept and characteristic of the ecosystem health assessment and in combination with the practical situation of Songyuan, we chose ecosystem vigor, organizational structure, maintenance of its service and health status of local citizens as the five main assessment factors, which were further subdivided into22indicators, and based on these indicators the index assessment system was built. Then weights of elements in factor and indicator level were determined respectively by a combination application of Analytical Hierarchical Process and Principle Component Analysis. Meanwhile, evaluation criterion and evaluation scale (sick, unhealthy, sub-healthy, healthy and very healthy) as to urban ecosystem health were also established by referring to both domestic and foreign relevant criterion.Urban ecosystem health assessment of Songyuan from2001to2011was conducted through fuzzy mathematical evaluation model and improvements of both overall healthy degree and healthy level of each element were found. These improvements are attributed to the economic growth of local area. Evaluation results show that the overall health degree of Songyuan from2001to2011were sub-healthy from2001to2011, and the health indexes were0.462、0.513、0.550、0.538、0.569、0.612、0.688、0.653、0.708、0.719、0.723respectively. According to the results of forecast models and fitting curves facilitated by MINITAB, urban ecosystem health index will experience a steady rise and the index will be more than0.8, which means very healthy, for most of years from2012to2020.The health assessment of Songyuan’s urban ecosystem can not only reveal what exist in the city’s ecosystem and the reasons that may lead to the situation, but also forward some management polices to maintain the urban ecosystem health of the city and promote a virtuous cycle and healthy development of the urban ecosystem and achieve the city’s sustainable development.