Value Of Urban Green Space And Its Assessment

Urban green space is the tract where the natural landscape is kept or recovered in city. It is the comprehensive reflection of urban natural and cultural landscape, and is the important part of urban landscape and the ecological space that reflects ecology best. With the acceleration of urbanization and the increase of urban population, urban green space plays a more and more important role in improving the urban ecological environment and advancing the sustainable and healthy development of urban economy. However, we have ignored the value of green space for a long period as affected by the traditional economic theory. Because the land was used without being paid under planned economy system especially, the value of urban green space cannot be reasonably reflected, and the characteristic and use of it cannot to be stabilized. Besides, due to the absence of value, the urban green space is hard to be allocated by the market, the consequence of which is that green space becomes the subordinate of city planning or land use planning, and is unable to form a reasonable systematic structure and exert its ecological value. At the same time, as a public goods, urban green space cannot form a demand market, and its tremendous ecological effect, economic effect and social effect can not be embodied, so the investment of green space construction lacks internal benefit driving, which will ultimately affect the sustainable development and industrialization of urban green space construction. Therefore, the research on the value of urban green space and its assessment technology is an urgent task in the preservation, planning and construction of urban green space. It has great theoretical and practical significance either to the improvement of environment resource value theory, or to the increasing of public environment protection consciousness, or to the perfection of urban land price system and the regulation of green space management. Just based on such a background and practical needs, this paper makes systematic research on the value of urban green space. The main content and conclusion are as following: 1. Using the theory of eco-economics, the paper studied the connotation, characteristics andstructure of urban green space eco-economic system. Based on this, three service functions119(ecological function, economic function and social function) of urban green space were pointed out, and their meaning was analyzed.2. Using the theory of utility value, theory of labor value, theory of value engineering and theory of ecological environment value, the paper analyzed the value of urban green space. And form that pointed out the nature of urban green space is a kind of ecological environmental value. Contrasted with the value components of biodiversity, land resource and environment resource, the author confirmed the value of urban green space includes the following type: direct using value, direct service value, indirect functional value, option value, bequest value and existence value. And the connotation and characteristics of each value type were analyzed.3. From macro and spatial-temporal aspects, developing stage index, environment pressure index, landscape pattern index and accessibility index, which affect the value of urban green space were brought forward. Developing stage index is a relative value indicating the impact of city economic and social developing level on urban green space value. This paper established a model of developing stage index, which demonstrated the change of urban green space value, and calculated the developing stage index of Hangzhou city from 1990 to 2000, which revealed the features of temporal change of urban green space value. The environment pressure index indicates the burthen degree of urban green space toward the outside environment. An index system used to analyze the environment pressure of urban green space was put forward, and a method to assess the environment pressure of urban green space with GIS technology was designed. Landscape pattern index reflects th...