Study On The Landscape Ecological Planning Of Urban Greenland System Of Yong'an City

As one of the urban landscape elements, the urban green-land system is the only close-to-nature ecosystem, and it plays a greatly irreplaceable part in bettering the ecological quality of urban region, in guaranteeing the sustainable urban environment and in forming the city image and urban landscape etc.. With a combination of the hot issue in the current study of the urban green-land system and its construction reality in Yong'an city, the urban green-land system in Yong'an was studied preliminarily in the paper by trying to combine the principles and methods of landscape ecology with the characteristics of urban landscape green-land system study, through which the ecological landscape planning of the urban green-land system was conducted in Yong'an. The results as follows:(1)According to the classification principles of landscape ecology, the urban green-land landscapes in Yong'an were divided into five types, namely, park green-land, production green-land, protective green-land, attached green-land and other green-land. Take Year 2006 as an example, the area of park green-land, production green-land, protective green-land, attached green-land and other green-land in Yong'an was respectively 115 hm2,35.58 hm2,9.65 hm2, 222.87 hm2, and 119.67hm2. Obviously, attached green-land and other green-land in Yong'an dominated, which was in accord with the reality that tourism was the backbone industry of Yong'an. The proportion of the protective green-land accounted for was a little, but it still played an ecological role in preventing natural disasters and city pollutions. While the numbers of the park green-land increased with the enhancement of city living quality. And the production green-land has been relatively stable since 2001.(2)The spatial pattern change of urban landscape during 1995～2006 was analyzed and evaluated by using landscape pattern indexes like landscape diversity index, landscape evenness index and dominance index etc., and the results showed that:in 1995, the total area of green-land was 429hm2, its coverage was 32.2%, and the area per capita was 39.36m2. While in 2006, they were respectively 502.77hm2,38.7%, and 37.68m2, obviously, the total area and the coverage of green-land increased by 17.19% and 20.17% in comparison with that in 1995, while the area per capita decreased by 4.27%, which showed that though the city afforestation level was improved, yet the area per capita of green-land decreased due to the explosion of the city population. During the twelve years, landscape pattern indexes such as landscape diversity index, landscape evenness and dominance index of the green-land system in Yong' an have changed, and increased respectively from 0.4962,0.7099, and 0.6237 in 1995 to 0.5659,0.8092, and 0.6892 in 2006. The diversity indexes increased, which indicated that the difference in proportion among each kind of green-lands reduced, and then caused the increase in evenness index. While it was likely that the increase in dominance had something to do with the extensive increase in total area.(3)With the priority that afforestation could improve the ecological environment of the city, and could satisfy the double objectives of the tour and appreciation as well, the main issues in the ecological landscape planning of the urban green-land system in city districts in Yong'an, such as the planning principles, indexes and green-land structure pattern were emphasized and studied. On the basis of the evaluation results, the ecological landscape planning of the urban green-land system in city districts in Yong'an was discussed. According to the planning, the park green-land along Yanjiang coast which was inside the built-up district, including Xiahe garden, Yangdingshan Park, North Tower, Mount Turtle Park, Waterfront Park, North Bridge Park, South Bridge Park, Dazhoudun, and the district from Xingping Park to Taoyuandong Scenery District, formed a large-scale Mount Turtle Park with an area of 180hm2, which formed a big green pistil. Then, with the blue axis made of three main rivers, the frame formed by mountain green-land, and the green axis composed of avenue and protective green-land, the green pistil was lengthened and expanded, and all the green-lands inside the urban district were connected to each other, through which the urban green-land system with the structure of long cane bearing melons was formed in Yong'an, thus the theoretical reference was provided for the city construction and development.