基于灯光数据的中国县域城市规模时空格局分析

为掌握城市规模时空格局演化规律,促进区域协调发展,以平均灯光强度表征城市规模,采取探索性时空数据分析(exploratory time-space data analysis,ESTDA)的研究框架对我国1992～2015年的县域城市规模时空格局进行分析。结果发现:(1)中国县域城市规模的核心-边缘结构与局部空间关联格局较为稳定但趋向动荡,城市规模变化呈现出"稳步增长"、"逐级递增"的特点,城市局部关联较弱,缺乏共同向上跃迁的动力;(2)京汕断裂带、110°E与100°E三条LL断裂带将城市规模空间格局割裂,阻碍了区域协调发展,但城市规模空间格局有可能突破胡焕庸线;(3) 2003年后城市规模的局部空间动态性、增长波动性与局部依赖性增强。东部的局部空间动态性趋于稳定,中西部局部空间动态性开始增强,城市规模增长波动性与局部依赖性重心向南方与东北方向转移;(4)自然因素、交通状况、城市行政级别、政策导向、经济发展水平、人口规模与空间临近效应是影响县域城市规模时空格局的主要因素。研究表明利用灯光数据进行城市规模研究具有科学性与可行性,未来应该着力构筑东中西部互联互动的网络通道,实现区域协调发展。

Study on Spatial-temporal Pattern and Dynamic Evolution of City Scale at County Level in China Based on Night-time Light Data

It is necessary to research the city scale, especially the change of spatial-temporal pattern and the dynamic evolution of which is the key to promote regional coordinated development. Based on the night-time light data, this paper calculated the city scale at county level in China during the 1992-2015 by average night light index, then analyzed it by ESTDA framework. The result shows: First, the core-periphery structure and the local spatial pattern of city scale is stable, but was becoming fluctuating. The city scale was growing slowly, but the city local correction is weak, and lacks the force of common motivation to jump upward. Second, the spatial pattern of city scale was separated by Jing-Shan economic trough belt, 110°E belt, and 100°E belt, however the Hu Line may be broken in the future. Third, the local spatial dynamics, growth volatility and local dependence of the city scale after 2003 was increased, and the local dynamics of city scale becomed stable in east, but unstable in west. Meanwhile the center of growth volatility and local dependence shifted to the south and northeast; Forth, the main factors affecting the spatial-temporal pattern and dynamic evolution of city scale at county level were the natural factors, traffic conditions, urban administrative levels, spatial effects, policy orientation and economic development level, and so on. Finally, this research has proved that it is scientific to use the night-time light data to calculate the city scale, and it is important to establish a network for different regions to achieve coordinated development.