城市土地利用空间结构分析的尺度效应

Scaling Effect in Analysis of Urban Land Use Spatial Pattern

以蛇口工业区为例,采用土地利用信息图的方法、引入均质度的概念研究了城市土地利用空间结构,分五种网格尺度讨论了均质度随网格大小变化的规律.研究表明,土地利用的均质度随着划分的网格尺度的变化而相应变化,信息单元的尺度越小,土地利用的均质度也越小.其原因是网格越大,越能掩盖零散分布的细小土地斑块,强化了区域内主要的土地利用类型;相反,随着网格的缩小,小地块的信息就可以逐渐提取出来,提取的土地利用信息变得复杂.

The urban land use spatial pattern in terms of land use evenness obtained from land use information map is studied. Taking Shekou industrial district of Shenzhen City as an example, the industrial clusters and residential clusters are defined in the map. The land use evenness was calculated for the two kinds of clusters on 5 different spatial scales that were denoted by 5 different grid sizes in obtaining the land use information maps. The results showed that the values of land use evenness change with the grid size. The bigger is the grid size, the greater is the value of evenness. Because big grid sizes tend to smooth the fine land use patterns while make the dominating land use patterns to stand out. On the contrary, as the grid size is getting small, the information of fine land use patches is extracted and structure within a grid becomes more complicated. Thus, in order to reflect the true evenness of a given urban area and to assess the land use efficiency, a proper scale should be selected.