空间场能是区域中心城市借助区域联系通道带动腹地发展而产生的"势能差"的抽象表达,可有效刻画区域发展格局与空间差异。采用主成分分析法与指标体系计算城市结节性指数,借助ArcGIS软件平台,采用累积耗费距离法、K阶数据场和ESDA等方法,综合测度了中国287个地级以上城市可达性与空间场能,并分别从省域、市域、县域等单元探讨了中国东中西三大地带与南北场能差异的空间格局与演变特征。结果表明:中国地级以上城市的可达性条件不断改善,平均可达性时间从1991年的246.98min缩短为2010年的193.43min。空间场能显著增长且空间分异性显著,分布结构由单核向多极网络状形态转变。县域场能存在显著的空间极化现象,场能热点区域的分布呈现显著的热点-次热点-次冷点-冷点自东向西带状分布的格局。依据场能分析结果,将全国划分为3个一级经济区和26个二级城市经济区。

Spatial filed is an abstract concept to define the potential difference came from the process of the growth pole of regional economy driving the economic development of periphery areas through transport corridors. In this paper, complex components for calculating the urban nodality index are selected, with consideration to the following five specific aspects, i.e., economic development, social progress, science & education, resources & infrastructure and ecological environment conditions. With the application of raster cost weighted distance method,k-order data fields and EADA(Exploratory Spatial Data Analysis),this paper attempts to comprehensively measure the regional accessibility and the spatial field of cities at prefecture level or above in China,and to reveal the spatio-temporal characteristics of macro disparities,the three zones and the economic disparities in the Northern-Southern China from inter-province,inter-city,inter-county. The results indicate that the accessibility condition continues to be improved and the average accessibility is min and 193.43 in 1991 and 2010 respectively,increase by 53.55min. Moreover,spatial filed have been increasing significantly from 1991 to 2010,while the economic disparities are different at different research scales. The distribution pattern of spatial field appears to be single-core form in 1991,while that in 2010 tends to be "multi-polar" network form. The differences between the Southern and Northern China evolves from "South and North are in balance" to "South is stronger than North".. On the basis of measurement and analysis for urban spatial filed,a two-level zoning project of urban economic regions of the whole country is put forward.