Coupling Of Urbanization And Ecological Environment In Ecologically Fragile Areas

As a system with very high degree of openness and strong dependence, city interacts with its surrounding environment and economic community. Urbanization is not only a process of population movements, changes in the landscape, industrial clustering, ecological improvement, but also a process of urban development and the surrounding ecological environment interaction. For the coercion and restraint mechanisms in the interactive coupling of urbanization and ecological environment, eco-environment urban coupling is defined as the interaction phenomenon of elements in respective coupling system between cities and the ecological environment.Northern Shaanxi, locating at the Loess Plateau hinterland, whose ecologicalenvironment is fragile, is China's important chemical and energy industry base. Withrapid industrialization and the construction and development of the chemical industrybase, rapid development of urbanization in northern Shaanxi takes greater pressure tothe fragile ecological environment. Based on deeply studying the mutual interactionof urbanization process in northern Shaanxi and its fragile ecological environment, thecoupling mechanism and law between urbanization phenomenon and ecologicalenvironment are confirmed in this paper. And then, to provide guidance for the healthy,stable, sustainable and efficient development of urbanization and ecologicalenvironment, response measures to solve contradictions between the process ofurbanization and regional ecological environment, to advance the process ofurbanization and to achieve the sustainable development of the ecologicalenvironment in northern Shaanxi are put forward.Through systematic research, following main conclusions are concluded:(1) The measure index system of fragile ecological environment in northern Shaanxiis constructed, the ecological vulnerability of northern Shaanxi is identified andthe overall ecological environment of Yan'an areas is better than that of Yulinareas. At present, the conties with the most vulnerable ecological environment innorthern Shaanxi are Suide County, Wubao County, Qingjian County.And the counties with relatively good ecological environment are Baota District, Huanglong County, Huangling County, Yuyanggou, Fuxian etc.(2) Based on the evaluation studies of the ecological vulnerability, ecological footprint, ecological carrying capacity and ecological deficit from 2001 to 2006 in northern Shaanxi are counted. The fact that the regional ecological carrying capacity in northern Shaanxi in recent years can not meet the needs of the ecological footprint, with a growing trend, is pointed out. For the development of the two cities in northern Shaanxi has gone beyond the scope of the ecological carrying capacity, this model is not sustainable, and the ecological environment in an unsafe state.(3) In the analysis of the main driver mechanism of urbanization process in northern Shaanxi, as well as the migration from rural areas to urban areas and the industrial development, it also includes the constraints mechanism from the ecological environment, water resources, and system innovation. At the same time, a GM (1,1) model for the urban population scale and the urbanization level in northern Shaanxi, considering a combination of factors in the actual situation, is used which forecasts that the sizes of population in northern Shaanxi in 2010 and 2020 will be about 5.9 million and 6.66 million, with 2,225,000 and 2,505,000 in Yan'an city and respectively 3,698,000 and 4,107,000 in Yulin city. The urbanization level in northern Shaanxi in 2010 and 2020 will be 50% and 68%.(4) Evaluation indicators of the coupling of urbanization and environmental in northern Shaanxi are identified and are evaluated by factor analysis and coordination model. Then, the quantitative models of urbanization rate, the environment index, coordination and development coordination are constructed to quantitatively analyze the coupling measurement between urbanization and the environment, and to reveal the interactive coupling degree and type between urbanization and the environment of northern Shaanxi and the law of environment quality change in the urbanization progress.(5) By calculating the water poverty index (WPI), the water pressure index (WSI) in northern Shaanxi, a preliminary analysis of the security situation in the area is made, the requirements of life, production and eco-environmental water in 2010 and 2020 in northern Shaanxi are forecasted. Combined the water resources available in 2010 and 2020 in northern Shaanxi, the balance index of water supply and demand (IWSD) in northern Shaanxi in 2020 is forecasted to be -0.13 and -0.16, stating that the socio-economic system of water resources will be not a carrier in 2010 and 2020 in present utilization conditions in northern Shaanxi. At the same time, based on the forecast of the urbanization level in 2010 and 2020 and reasonable estimates on the per capita GDP in northern Shaanxi (an increase of 10%), the water quantity of city life will increases by 0.3793 billion cubic meters in Northern Shaanxi, containing 0.1422 billion in Yan'an and 0.2371 billion in Yulin, when the level of urbanization increases by 1%.(6) Based on the analysis of the urbanization development pattern in northern Shaanxi, the sustainable development strategies in northern Shaanxi and the protection measures for coordinated development between urbanization and ecological environment in northern Shaanxi are pointed out.