Quantitative Analysis And Optimization Research Of The Urban Ecological Land In Changsha

Urban ecological land, including forests, farmland, grassland, wetland, water area, and so on, plays an important role in ecosystem services, while the city extension is gradually making the ecological land into the residential areas, building areas,etc, which do not make any ecological efficiency. In order to achieve the city's sustainable development and sustainable land use, and ultimately the social, economic, ecological and environmental development, how to protect the essential ecological land ecosystem for the maintenance of the city's own health, to improve the urban quality of life and urban sustainable development are of great significance. Meantime, how to take the most advantage of ecological land becomes the key matter in city sustainable development. Now, there are lots of researches in ecological land. However, most researches remained in the qualitative analysis and the analysis of ecological land classification, not in the landscape pattern correlation analysis. Therefore, according to this urban feature, this research changed the distribution pattern of ecological land in order to optimize their ecological efficiency, without changing the total ecological land.As a case study in Changsha, this research explored an evaluation index system and an optimization method, with the help of catastrophe progression method, remote sensing, GIS and Fragstats software. The research identified and estimated the status of ecological land use of Changsha, and constructed the ecological corridors. The research focused on eco-regional processes on basis of RS and GIS technology, and completed the optimization.The results show that:Changsha urban ecological land evaluation in 2007 is 0.9379 by quantitative evaluation of catastrophe progression method. The quantitative index of which is 0.8912, the structural index of which is 0.8399, the coordination index of which is 0.7740. On the whole, Changsha urban ecological land is at a general level and its ecological efficiency is general. The indexes have big difference and develop unevenly, especially the coordination index is much lower than the other two indexes. To this point, this research makes an optimization study in the coordination index.Before the optimization, this research made an analysis in the landscape of ecological land. And the corresponding indexes of ecological land types were comparatively low on the whole. The map of conflict analysis is superposed by the status map of ecological land use and the ecological function regionalization map. And the ecological corridor distribution map is produced by using 'Least-cost'modeling. The research optimized urban ecological land through changing the areas of conflict with changing the total. The ecological efficiency is higher after optimization, with the value of 0.9618. And the Shannon diversity index, the Simpson diversity index, the aggregation index and the interspersion and juxtaposition index respectively increased to 0.9384,0.530,66.8823,59.6985. Eventually the coordination index was increased and then the more ecological efficiency was made.