Study On The Frameworks,the Functions And The Landscape Ecology Planning Methods Of Urban Green Corridors

As an important aspect of landscape ecology, the studies on corridors are permeating urban ecology and urban landscape planning. Green corridor is a key landscape type. This paper communicates clearly about the definition and the classification of green corridor. Additionally, it analyses urban green corridor's structure, pattern and function. Applying the method for landscape ecology planning to urban green corridor planning, this study notes five steps of green corridor planning, which are as follows, first, investigating basic data, secondly confirming targets and functions, thirdly ecology planning, fourthly implementing plans and designs and last, managing planning projects, and the former three stages are analyzed clearly. The four scales of green corridor planning and the methods for data analyzing, confirming functions, targets, width of various kinds of urban green corridors are studied.This paper notes that according to the model of vehicle emission dispersion and the model of noises dispersion, the width of green road-side corridor can be confirmedexactly. The results show that when downwind distance is meters, the surfacepollution concentration is the max. Arranging green road-side corridor before this distance can effectively decrease the max concentration and the concentrations at different distance. When there isn't enough room to arrange dividing strips, we can assume thepollution origin as the midline of road. If the half width of road is shorter than meters, the sum of green road-side corridor width and half road width ought to be equal toor greater than meters, and the greater the green road-side corridor width is, thebetter effect is. If the half width of road is greater than meters, green road-sidecorridor should be arranged from roadside and the greater the green road-side corridor width is, the better effect is. If roads have dividing strips, and there is enough room to arrange diving strips, green road-side corridor should be arranged according to the above principles regarding each slab as a road. Considering its function of reducing traffic noises, green road-side corridor should cling to the roadside, and the wider the greenroad-side corridor is, the better effect is.The environments along the roads comprise six categories. The first category is shopping center, the second one is culture and education, habitation, the third one is heavy industry, the fourth is water area, the fifth is farmland and the last one is natural vegetation, mountain and park. The methods for planning green road-side corridors along different roads with different environments are studied exhaustively.This paper applies the above principles and methods to Wuhan's green corridor planning, points out the problems of its green corridors by analyzing its corridors' form, network, the relationship between green focuses and green corridors, the relationship between heat island effects and green corridors. The results show that Wuhan's all kind of green corridors in each district, especially the green belts, are very scanty. The connectivity of green corridor network is so low, the width is so narrow, and inside environments can not be formed. Some of green focuses don't be connected each other by green corridors.Considering Wuhan's natural resources, regional status and the problems of its green corridors, the targets and the functions of Wuhan's green corridors planning are pointed out and confirmed, which are as follows, building ecological network connecting each urban green focuses, urban and rural green focuses; conserving and improving the diversity of species and habitats, the quality of atmosphere, the productivity of agricultural and horticultural acts adjacent to green corridors; development controlling and urban containment; improving urban microclimate, reducing heat island effects.Lastly, this paper plans and confirms the width, the direction and the pattern of Wuhan's green corridors. It points out that green network should be uninterrupted on the region scale, the urban scale and the district scale. When green corridors go through the thermal area, and their trends parallel the dominant wind direction, heat island effects can be alleviated greatly.