珠三角县域城市潜力的时空关联结构演变

基于1990、1994、2000、2005 和2009年公路网数据和经因子分析得到的县域城市综合实力指数，采用扩展的潜力模型测度县域潜力指数，运用时空自相关方法探讨珠三角县域潜力的时空关联格局及其演变，并与空间关联格局对比及与交叉相关函数比较检验其准确性。结果表明：① 珠三角县域潜力总体上具正时空关联性，但关联程度不高，1994-2005年缓慢加强而2005-2009年趋于减弱。大多县域潜力的局部时空关联特征相对稳定，且以正相关为主，但部分县市时空关联类型发生了明显转化。② 县域潜力的局部时空关联类型分布差异及其变化明显，时空HH区分布于中部地带和东部的深圳—东莞地带，2000年后中部的时空HH区范围收缩至广—佛核心都市区；西部时空LL区连片分布格局相对稳定，中南部2005年开始出现新的时空LL区，东部时空LL区范围1994-2000年扩大而后逐步收缩，2009年零星分布于东部边缘；时空异质区变化较剧烈。③ 三大地带县域潜力的局部时空关联特征反差鲜明，东部与中部差异趋于缩小，而西部与中、东部的差异进一步扩大。④ 时空自相关方法能有效挖掘县域潜力的时空关联模式，比仅考虑空间效应的ESDA方法更能准确客观揭示县域潜力间的时空交互关系。

Evolution of spatio-temporal association structure of urban potential at county level in the Pearl River Delta

Based on the road network data of 1990, 1994, 2000, 2005 and 2009 and urban integrated power index measured by factor analysis in the Pearl River Delta, this paper estimates county potential index using expanded potential model, and explores the spatio-temporal association structure and evolution of county potential using spatio-temporal autocorrelation techniques, and the validity of spatio-temporal association structure is verified in comparison of spatial association pattern and cross correlation function. The main results are obtained as follows: (1) The global spatio-temporal association of county potential showed a positive effect. But this positive effect was not strong, and it increased slowly from 1994 to 2005 and presented a decreasing trend from 2005 to 2009. The local spatio-temporal association characteristics of most counties' potential kept relatively stable and focused on a positive autocorrelation, however, there were obvious transformations in some counties among four types of local spatio-temporal association which are HH, LL, HL and LH. (2) The distribution difference and its change of local spatio-temporal association types of county potential were obvious. Spatio-temporal HH type units were located in the central zone and Shenzhen-Dongguan region of the eastern zone, but the coverage of the spatio-temporal HH area of the central zone shrunk to the Guangzhou-Foshan core metropolitan region only after 2000; the spatio-temporal LL area in the western zone kept relatively stable with a surface-shaped continuous distribution pattern, new LL type units began to emerge in the central and southern zones in 2005, the LL area in the eastern zone expanded from 1994 to 2000, and then gradually shrunk and scattered at the eastern edge in 2009; the spatiotemporal heterogeneity (HL and LH) area changed significantly. (3) The diversity of local spatiotemporal association of county potential among the three zones showed significant imbalance. The difference between the eastern and central zones tended to decrease, whereas that between the western zone and the central and eastern zones further expanded. (4) Spatio-temporal autocorrelation methods can efficiently mine the spatio-temporal association patterns of county potential, and can better reveal the complicated spatio-temporal interaction between counties than ESDA methods.