大城市边缘区景观破碎化空间异质性——以北京市顺义区为例

探索大城市边缘区景观破碎化格局及其空间异质性特征,有助于把握景观动态的变化机制及其生态问题.以北京市顺义区这一典型大城市边缘区为例,基于土地利用分类数据,采用有效粒度尺寸方法,对1992年、1999年和2009年景观破碎化空间变异进行了地统计学分析,主要包括尺度依赖性、空间异质性、空间格局及其生态过程的分析.研究结果表明:1)景观破碎化空间变异具有明显的尺度依赖性特征,由空间自相关部分引起的空间异质性较高；1992年和1999年景观破碎化空间总变异相对缓和,2009年空间总变异强烈；通过不同尺度上的异质性对比,选取1000m幅度作为研究区景观破碎化的空间异质性分析较为适宜.2)景观破碎化空间异质性表现出明显的上升趋势,土地利用斑块破碎化不断加剧,其中1999-2009年间的表现尤为强烈.3)景观破碎化高值区呈现出由东部向西部转移的态势,并且其空间布局具有集聚性与分散性的显著特征,空间上相似属性聚集与相异属性聚集的空间格局十分突出.4)景观破碎化空间自相关作用主要来自高强度社会经济活动的影响,并表现出明显的区位特征.该研究结果可为土地、城镇规划以及景观生态建设提供参考.

Analysis on spatial-temporal heterogeneities of landscape fragmentation in urban fringe area: a case study in Shunyi district of Beijing

In the rapid urbanization process, land use of the urban fringe changes dramatically, and the landscape fragmentation is particularly outstanding. Hence, exploration of landscape fragmentation pattern and its spatial heterogeneity of urban fringe area are helpful to grasp the change mechanism of landscape dynamic as well as its ecological problems. In this study, on the basis of the interpreted land use maps from TM imagery, we utilized a series of moving window analysis and geo-statistic methods combined with effective mesh size to investigate the spatial heterogeneity of landscape fragmentation in Shunyi district, Beijing. The study contents mainly include the scale dependency of spatial heterogeneity, spatial variation character of several typical scale, spatial patterns and its ecological processes on 1000m scale for landscape fragmentation. The results show that, 1) the landscape fragmentation of urban fringe area has obvious characters of scale dependency for spatial heterogeneity, which mainly caused by the spatial autocorrelation; the total spatial variation of landscape fragmentation is not obvious in 1992 and 1999, but in 2009 is very strong. According to the analyses of spatial variance characters at different scales and based on the land use structure of county-wide urban fringe area, we choose 1000 meters as a relatively appropriate scale for analyzing the spatial heterogeneity of landscape fragmentation. 2) During the research period, the spatial heterogeneity of landscape fragmentation shows an obvious upward tendency, and the fragmentation of land use patch is getting more and more serious, especially the fragmentation of arable land in the period of 1999-2009. 3) The high value area of landscape fragmentation shows the momentum of transferring from the east to the west, meanwhile its spatial pattern presents a remarkable feature of the agglomeration and dispersion, which similar attributes gather and otherness attributes gather, and this pattern presents a trend of aggravating. 4) The spatial autocorrelation effect of landscape fragmentation comes from high strength social economic activities, and it exhibits obvious location characteristics, which the radiation effect of the central city is strong and the transport network plays a very important promoting role. These research results can provide a reference for land planning, urban planning and landscape ecological construction. In addition, the multi-view research of landscape pattern and its ecological processes are still necessary to be deepened.