[Urban ecological land in Changsha City: its quantitative analysis and optimization].

In this paper, a hierarchy index system suitable for catastrophe progression method was constructed to comprehensively analyze and evaluate the status of ecological land construction in Changsha City in 2007. Based on the evaluation results, the irrationalities of the distribution pattern of Changsha urban ecological land were discussed. With the support of geographic information system (GIS), the ecological corridors of the urban ecological land were constructed by using the 'least-cost' modeling, and, in combining with conflict analysis, the optimum project of the urban ecological land was put forward, forming an integrated evaluation system. The results indicated that the ecological efficiency of urban ecological land in Changsha in 2007 was at medium level, with an evaluation value being 0.9416, and the quantitative index being relatively high but the coordination index being relatively low. The analysis and verification with software Fragstats showed that the ecological efficiency of the urban ecological land after optimization was higher, with the evaluation value being 0.9618, and the SHDI, CONTAG, and other indices also enhanced.