城市化过程中聚落规模与路网密度的动态变化

Dynamic changes of settlement scale and road density in urbanization:A case stud in Nanjing City

基于Landsat TM影像和相应时期的道路数据,对1988-2006年南京市聚落占地率和路网密度的变化及相互关系进行了研究。结果表明:1988-2006年研究区聚落规模和道路系统均快速增长,但相对增长速度均随其规模增大而减小,且聚落规模的相对增长速度快于道路;当聚落占地率较小时,聚落占地率和路网密度之比随聚落占地率的增加而迅速上升,当聚落占地率增加至约30%后,比值渐趋稳定,路网密度与聚落占地率将同比增长;聚落占地率及路网密度均随距中心城区距离的增加而下降,但其年均相对增长率在不同区位间及不同时期的差异性,路网密度均小于聚落规模,聚落动态更易受小尺度区位条件的影响。

Based on the 1988,1998,and 2006 Landsat TM images and road maps of Nanjing metropolitan region,this paper studied the dynamic changes of settlement percentage coverage （SPC）,road density （RD）,and their relationships during Nanjing in 1988-2006.In the study period,the settlements and road systems in the city expanded dramatically,but the relative growth rate （RGR） of SPC and RD decreased with their increasing processes.Comparatively,SPC increased faster than RD.The SPC/RD ratio increased rapidly with increasing SPC,but tended to be stable when the SPC increased to about 30%.SPC and RD all declined with increasing distance from the urban center,but the annual mean RGR of RD changed less with the location and the time period.Comparing with road systems,settlement scale was more easily affected by local factors.