中国近代城市体系的位序规模特征——基于1936年《中华民国邮政舆图》的分析

Rank-size distribution of the modern China urban system based on the China Postal Atlas in 1936

以往的中国历史时期城市体系的研究,受限于系统城市人口数据的缺失,无法进行定量化的城市体系位序规模分析。本文通过数字化1936年《中华民国邮政舆图》,在其13240个邮政网点和40余万km邮路的基础之上,分析得到了邮政网点和邮路核密度空间分布,利用泰森多边形和分区统计等GIS工具给近代中国城市的邮政能力T赋值。以T值作为城市规模的代用指标,进行城市体系的位序规模分析。结论显示:(1)基于T值的近代中国城市位序规模分布符合齐普夫法则;(2) 1936年存在京津冀、长三角、珠三角、武汉和成都—巴县5个邮政聚集区;(3) 1936年邮政网点和邮路空间分布存在"胡焕庸线"两侧的巨大空间分野,其西北半壁网点占比略少于人口占比,但高等级网点和邮路里程占比远高于人口占比;(4)本文将近代中国城市体系研究的样本量从以往的200左右(城市人口)提高到2360(T值),第一次发现了1936年中国城市位序规模曲线独特的"中段凹陷"而导致的曲线整体"三段式"分布,迥异于同时期的美国和当下之中国,近代约50个左右城市的开埠通商是造成"头部"城市在城市规模上与中等规模城市拉开差距的关键因素;(5)邮政能力T值可视为近代中国城市规模的一个优秀代用指标。

The lack of governmental and systematic urban population data limit the study progress in urban systems in China’s historical period, which has great negative effect on quantitative analysis of urban system rank-size distribution. This paper digitized the "China Postal Atlas" in 1936, based on its 13240 postal points and more than 40000 km postal routes,and examined the spatial distribution of the kernel density of postal points and routes, using the Thiessen Polygon, Zonal Statistics and other GIS tools to give value to the postal capacity T of modern Chinese cities. T-value is used as a proxy for city size in modern China to analyze the rank-size rule. The conclusions are as follows.(1) The distribution of rank-size of cities in modern China based on the T-value was in accordance with Zipf’s law.(2) In 1936, there were five postal aggregation areas in China: Beijing-Tianjin-Hebei region, the Yangtze River Delta,the Pearl River Delta, Wuhan and Chengdu-Baxian region, which is highly consistent with the current distribution of China’s urban agglomerations.(3) In 1936, the spatial distribution of postal points and routes was very different on both sides of the "Hu Huangyong Line". The northwestern half to the line had a slightly smaller proportion of points than that of population,but a much higher proportion of high-grade points and routes than that of population.(4) In this paper, the sample size of urban system in modern China increased from about 200(urban population) to 2360(T-value). For the first time, the "three-stage" distribution caused by the unique "depression in the middle section" of the city size curve was found, which was quite different from that of the United States and China today.(5) The postal capacity T-value can be considered as a proxy for city size in urban geography studies in modern China.