滨湖地区城市生态网络构建的完整性与优化对策——以西洞庭湖区常德市为例

SUPERIOR STRATEGIES AND ANALYSIS ON INTEGRITY OF URBAN ECO-NETWORK CONSTRUCTION IN THE REGIONS AROUND LAKE——TAKE CHANGDE CITY OF WEST DONGTING LAKE REGION AS AN EXAMPLE

城市生态网络是城市生态系统中物质流、人口流和信息流在空间分布上所形成的网络结构。滨湖地区城市生态网络由森林、农田、城镇和湿地生态系统网络构成,它们各自的或相互的连接性和通达性直接影响着城市生态网络的完整性。利用MapInfo Professional6.5 SCP软件、GIS查询功能和网络空间结构分析法,以西洞庭湖区常德市为个案,分析了其完整性。结果表明:①森林、农田和城镇生态系统网络中节点间的连接性差,α、β、γ指数都很低,其中α指数出现负值;湿地的连接性要好,但是指数也偏低;就整个区域而言,城市生态网络中交通线较多,等级较高,连接性处于中上水平。②市域内各城市生态功能区的可进入性较大,交通网络相对较发达,尤其是生态农业区的可进入性大。③在森林、湿地、农田三大生态系统17处生态功能区中,有5处节点的通达性最好,有3处节点的通达性最差。最后对城市生态网络完整性的优化提出了相应的对策与建议。

The urban eco-network is the network structure in the urban eco-system that the flowing of the substance, the population and the information have been formed in the spatial distribution. The urban eco-network in the regions around lake is made up of the eco-system of forest, farmland, town and wetland, whether respective or mutual, their characters of connection and smooth directly influence the integrity of urban eco-network. Using GIS, MapInfo Professional6.5 and the network analytical method, taking Chang de city of West Dong ting Lake as an example, the paper analyses the integrity of urban eco-network. The results show that （1） The characters of connection in the eco-system of forest, farmland and town are very poor between spots, the indexes of alpha, beta and gamma are very low, and the index of alpha appears negative; By comparison, the character of connection of the wetland is a little better, but its index is also low; With regards to the region, its character of connection is much better. （2） The characters of entrance in the eco-function districts is much better, transformational network is relative convenient, especially in the eco-agriculture district. （3） As to the characters of smooth in the eco-system of forest, wetland and farmland, 5 eco-function districts are the best, and 3 eco-function districts are the worst in the 17 eco-function districts. Based on the above analysis, the superior strategies on integrity of urban eco-network construction are put forward.