无锡城市用地扩展的时空特征与趋势分析

通过计算土地扩展集中指数和扩展强度，分析了无锡市土地扩展的数量特征，从横向和纵向比较、地类扩展、时段分析等方面刻划了城市土地扩展速度。认为无锡市土地扩展总体上属于快速增长类型，90年代建成区用地增长了50%。90年代中期以来，城市土地扩展强度以原锡山市最为突出，扩展区域集中于无锡市区；从时间序列分析，历年扩展强度相对均衡。从横向比较来看属于缓慢增长类型；从纵向比较看，80年代以来土地扩展弹性系数达3.3以上，属较快增长类型；从扩展地类来看，90年代以来工业用地和公共设施用地的增幅最大，其中工业用地疏于引导型用地类型；从异速增长类型分析，无锡市属于正异速增长型。在此基础上，采用时空相关性方法进一步揭示了城市、开发区、土地扩展参数的时空变化规律性。最后，文章对无锡市用地扩展趋势和方向进行了分析和总结，并提出了分区指导意见，指出无锡市拓展的方向以南部为最佳。

URBAN LAND EXPANSION IN WUXI CITY: SPACE-TIME FEATURES AND NEW TRENDS

By calculating concentration index of land expansion and intensity, the space time features of land expansion of Wuxi city are described in this paper. It indicates that the built up area has increased by 50 percent since 1990s. From 1990 to 1998, construction land have a net increase of 20 2 km 2, among them 38 52 percent are industrial land, which means industrial land increased at the speed of 4 82 percent each year. It also indicates that expansion is mostly occurred in city proper of Wuxi city since the middle of 1990s. Taking city proper as an example, built up area has increased from 65 4 km 2 to 97 8 km 2 from 1990 to 1999, having a net increase of 32 4 km 2 in 9 years. Analyzed in terms of time, expansion rate in each year is comparatively balanced. While with respect to city proper of Wuxi, land expansion fluctuates since the middle of 1980s, which has two heights, namely, in 1985 and in 1990, when the elastic coefficient of land expansion is over 3 3. Thus it is argued that the land expansion of Wuxi is a highly increased type. In terms of allomertry, this type can be called a positive allomertric type, that is, the expansion rate of built up areas is much bigger than that of non agricultural population in city proper. Therefore, the main time space features of land expansion in Wuxi city are explored and its developmental trend is estimated. Finally, it is suggested the south be the feasible direction for land expansion in Wuxi city, based upon the comprehensive research within this region.