长沙市城市生态用地的定量分析及优化

构建了适用于突变级数法的层次结构指标体系,对长沙市2007年生态用地建设的现状进行了综合分析与评价,基于现状评价结果,探讨了长沙市城市生态用地分布格局的不合理之处,在GIS的支持下,利用最小耗费距离模型构建了生态用地的生态廊道,并结合冲突分析,提出了城市生态用地的优化方案,形成了一套完整的城市生态用地评价系统.结果表明:长沙市2007年城市生态用地现状评价值为0.9416,生态效能一般,其中,数量指标相对较高,而协调指标相对较低;优化后的突变值为0.9618,生态效能处于较高水平.通过Fragstats软件对优化后的生态用地多样性(SHDI)和聚集度(CONTAG)指数等进行验证的结果表明,与优化前相比,优化后的数值均有所提高,提高了生态用地的生态效能.

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.