1947～2007年上海中心城区居住空间分异变化——基于居住用地类型视角

采用4种分异度测度模型,在街坊尺度和乡镇尺度下,对上海中心城区1947～2007年11个时相的各类居住用地空间分异程度进行计算。发现1949年后各类居住用地分异度呈现不同的波动过程。不同时期居住用地总体分异程度的计算表明,1949年前空间分异严重,计划经济时期有所降低,转型期则又明显上升。不同时期居住用地等级高低与其分异度大小呈现不同的结构特征,1949年前高等级居住用地分异度高、中低等级居住用地分异度较低,形成"一高两低"结构;计划经济时期则是居住用地等级越高,分异度越大的"正相关"结构;90年代后则是最高和最低等级的居住用地分异度高,而中等居住用地分异度最低的"V"型结构。不同时期居住用地空间分异结构特征间的演进,直接原因是新式住宅的建设和旧城的改造,深层次原因则是土地使用制度的变迁和城市空间组织模式的转变。

Evolution of residential differentiation in Central Shanghai City(1947-2007):A view of residential land-use types

Based on long-term residential land-use data,this paper makes a calculation on the dissimilarity of diverse residential lands,which might be used as reference in the perspective of physical changes of residential spaces.(1)This study classifies residential land use of downtown Shanghai into 6 types:garden house and villa(coded as R1),high-rise apartment before 1949and workers'community after 1949(R2),commercial residential building(R2N),li-nong residential building(R3),shanty town(R4)and rural house(E6).Then,calculations are made on the spatial differentiation,i.e.the index of dissimilarity(D),spatial-modified dissimilarity index(D(s)),multi-group dissimilarity index(D(m))and spatial-modified multi-group dissimilarity index(SD(m))of various land-use types on the spatial scale of blocks and towns.(2)The result shows that the changing of residential spatial differentiation in different time series is not affected by scale effects or whether the dissimilarity index is spatial-modified or not.(3)From 1947 to 2007,in the type of garden house and villa,the dissimilarity maintains high,while the dissimilarity of commercial residential building keeps decreasing.In other types,however,the dissimilarity has a wave change.(4)D(m)of residential land-use shows that residential segregation might be notable in 1947,and decreases obviously from 1947 to 1979,while D(m)of residential space decreases obviously,and increases significantly from 1979 to 2007.(5)The relation between the hierarchy and the dissimilarity of residential land differs in various periods.Before 1949,the dissimilarity is high within high-rank residential land,whereas the index is quite low in medium and low rank residential land.During the socialist period,the rank and the dissimilarity have a positive correlation.In the transitional period,a"Vshaped"pattern can be found,which means that the dissimilarity of high rank and low rank residential land is high,and low dissimilarity can be seen in medium rank residential land.This indicates that the residential space of Shanghai has been polarized in terms of physical environment.