南京中心市区居住用地水系可达性分析

为探讨水系可达性对城市居住用地分布的影响,基于交通可达性的概念和最短路径分析法,在GIS平台上构建了城市居住用地水系可达性模型.借助ArcGIS9.2软件,计算了不同交通等级的最小时间成本,分析了南京中心市区1990年和2008年居住用地的水系可达性时距圈和新增居住用地分布的变化特征.研究表明:从1990年到2008年,南京中心市区水系可达性在5 min以内的居住用地的比例约降10%,在5～10 min之间的增加5.8%,在10～20 min之间的增加5.4,在20～30 min之问的没有明显变化;约80%的新增居住用地分布在10 min水系可达范围内,说明近20 a来,南京中心市区近距离水系可达性居住用地的比例呈下降趋势,但新增居住用地具有明显的亲水性特征.

Analysis of Residential Accessibility of Stream Systems in Downtown Area of Nanjing

To research the effect of the accessibility of stream systems on the distribution of residential areas, an accessibility analysis model was built in the module of GIS (geographic information system)software based on the shortest distance analysis method and the transport accessibility theory.ArcGIS9.2, a software, was used to determine the least time cost of different-class transportation and analyze the time-distance circle of the residential accessibility of stream systems and the distribution of newly-buih residential areas in the downtown area of Nanjing, as an example, in the years 1990 and 2008. The analysis results show that from 1990 to 2008, residential areas within 5-min accessibility of stream systems decreased by about 10% in the downtown, those between 5- and 10-min accessibility and between 10- and 20-min accessibility increased respectively by about 5.8% and 5.4%, whileresidential areas with over 20-min accessibility did not change basically. About 80% of the newly-built residential areas in the downtown area were located within 10-min accessibility. It can be concluded that the proportion of residential areas within 5-min accessibility of stream systems has decreased in the downtown in the past 20 a, but the newly-buih residential areas have displayed an obvious tendency towards water areas.