中国城市规模体系及其空间格局Zipf-PLE模型的评价

近30 a来,中国城市规模体系发生了重大变化,突出表现在人口城市化、用地城市化和经济城市化方面。利用GIS平台,综合城市常住人口、建成区面积和经济总量等因素构建Zipf-PLE模型,以全国县级以上城市为研究对象,对中国城市规模体系的空间格局进行了深入研究。结果显示：（1）2010年,中国城市规模体系等级健全且成熟,呈现“中间略大、底端偏小”的较为合理的金字塔格局。其中,西部地区城市规模体系结构最为合理,呈现出“底端大,顶端小”的金字塔格局;东部地区城市体系等级比较健全,中等城市最多,呈现“中间大,两端小”的金字塔格局;中部地区城市体系等级不全,超大城市缺失,呈现“中底端大,顶端小”的金字塔格局。（2）中国省域城市规模体系是合理的,中等合理以上的省份占90.32%。除直辖市外,全国27个省份中有8个省份城市规模体系趋于分散,19个省份趋于集中。（3）对全国省域城市规模体系进行合理度分区,京、沪、津、渝、新、黑、桂、陕、甘、闽、吉11省市为高合理区;粤、晋、云、湘、贵、辽、赣、苏、浙、川、冀、豫12个省（区）为较高合理区;鄂、鲁、皖为中等合理区;琼、蒙、宁为低合理省区;青、藏为不合理省（区）。

Evaluation of China's Urban Scale Structure and Spatial Pattern Based on Zipf-PLE Model

Great changes have taken place in China's urban scale system during the last 30 years. The driving forces that cannot be ignored include following factors: the population urbanization propelled by its aggregation, the land urbanization driven by its revenue, and the economic urbanization promoted by GDP. Using the analytical tools of GIS integrating three factors of resident population, built-up area and economic output, we constructed Zipf-PLE model for a in-depth research on the spatial pattern of China's urban scale system. The result shows that: (1) in 2010, China's urban scale system is matured with completed levels of hierarchy, which is reflected by a relatively rational pyramid-shaped pattern with larger scale locates in the middle while smaller scale stays at the bottom. The urban scale system structure in the western region has the highest rationality, which presents a pyramid-shaped pattern with larger scale at the bottom and smaller scale at the top. The urban scale system structure in the eastern regions is relatively sound and contains the largest quantity of medium-sized cities, indicating a pyramid-shaped pattern with larger scale in the middle and smaller scale at both ends. The urban scale system structure in the central regions is featured by its incomplete urban system hierarchy, which lacks megacities especially, and presents a pattern with larger scale in both the middle and the bottom, while having smaller scale at the top. (2) The overall urban scale system in China at the provincial level is rational, with 90.32% of the provinces being moderately rational. Among all 27 provinces, except 4 municipalities, the urban scale system patterns of 8 provinces are inclined to disperse and the other 19 tend to concentrate. (3) Furthermore, we allocate the provincial urban scale systems in China into different categories according to their rationality rankings, which are: the high-level (with 11 provinces and municipalities including Beijing, Shanghai, Tianjin, Chongqing, Xinjiang, Heilongjiang, Guangxi, Gansu, Fujian and Jilin), the relatively high-level (with 12 provinces of Guangdong, Shanxi, Yunnan, Hunan, Guizhou, Liaoning, Jiangxi, Jiangsu, Zhejiang, Sichuan, Hebei and Henan), the medium-level (provinces of Hubei, Shandong and Anhui), the low-level (provinces of Hainan, Mongolia and Ningxia), and the irrational areas (provinces of Qinghai and Tibet).