长江三角洲生态用地破碎度及其城市化关联

破碎化是当今地表自然景观演化的重要形式。基于县(区) 行政单元，利用GIS 技术和景观生态方法，定量探讨了长江三角洲生态用地破碎分区及其城市化关联，研究结论有：① 建立了生态用地破碎度综合模型，并与城市化规模和空间构型等参数聚类，将全区划为2 个 高破碎区、3 个中等破碎区和2 个低破碎区；② 基于区县尺度和30 m 分辨率影像的生态用 地破碎度是城市化、生态用地特征及其他干扰源的综合表现，与城镇化水平和城镇用地比例 等规模参数相关性不明显，相关系数分别为0.303、0.432，但与城镇用地聚合度呈现明显的负相关，相关系数为-0.807；③ 破碎分区及破碎度的城市化关联为不同生态用地空间战略的选择提供依据，对面向生态保护的城市化空间引导和规划具有指导意义。

Ecological Land Fr agmentation and Its Connectivity with Urbanization in the Yangtze River Delta

Rapid fragmentation of natural ecosystems by anthropogenic activity is the important form of natural landscape evolution on earth surface today. In an ecological sense, fragmentation involves dividing up contiguous ecosystems into smaller areas called 'patches'. The development of fragmentation indices mostly parallels the development of landscape ecology. This review examines landscape indices and their usefulness in reflecting the effects of ecosystem fragmentation. Then on the basis of Geographic Information System technology and landscape ecological method, the paper defines the concept of ecological land and measurement indices of fragmentation and urbanization size and spatial configuration, and then quantitatively explores fragmentation properties of ecological land and their relationship with urbanization in the Yangtze River Delta area. Our findings are summarized into three points of view in the end of the paper. (1) Ten fragmentation indices such as MPS, LPI, CAI, NP, PD, FD, SI, MNN, AI and CO based on landscape ecology are firstly handled by selecting the method of Principal Component Analysis of SPSS, and then there are three principal components extracted. The first principal component is defined as size component highly loaded by indices of MPS, LPI, CAI, FD, SI, and the second principal component defined as numeral component highly loaded by NP and PD, and the third component defined as spatial configuration component highly loaded by MNN, AI and CO. According to three principal components the general fragmentation model of ecological land F has been set up. Then the Cluster Analysis is selected to analyze the relationship between F and urbanization level U, urban land ratio UA and Aggregation Index of urban land UI. Lastly there are seven categories areas to be clustered for fragmentation of ecological land in the Yangtze River Delta area, which include two high fragmentation areas (F1, F2), three moderate fragmentation areas (F3, F4, F5) and two low fragmentation areas (F6, F7). (2) Based on the spatial scale of county area and the remote sensing image of a 30-metre resolution, fragmentations of ecological land are the combined representation of urbanization, ecological land properties and the other disturbance resources. The general mode of ecological land fragmentation F has no evident relationship with urbanization level and urban land ratio, whose relative coefficients respectively are 0.303 and 0.432, but has a very clearly negative relationship with urban land Aggregation Index, whose relative coefficient is-0.807. (3) The conclusions of ecological land fragmentation areas and their connectivities with urbanization provide scientific basis for selecting spatial strategies of ecological land safety patterns. At the same time it is very meaningful to guide scientifically urban spatial development direction. The following researches about this topic mainly are from three aspects:exploring influencing factors for ecological land fragmentation by use of high-revolution image data in typical areas;analyzing fragmentation and its connectivity with urbanization based on the buffer zone around urban area;and revealing the dynamical process of ecological land fragmentation caused by urbanization.