1980-2015年珠三角城市群城市扩张的时空特征分析

以珠三角城市群9座城市为研究对象，基于1980-2015年3期遥感影像提取的土地利用数据，通过扩张强度、扩张速率以及景观格局指数定量分析珠三角城市群尺度上城市扩张的时空变化特征。结果表明：（1）城市群扩张数量特征：1980-2015年珠三角城市群建设用地面积扩张约3倍，1980-2000和2000-2015期间分别扩张1513.1、3043.8 km²；扩张强度不断增强，扩张速率明显加快。（2）城市群扩张空间特征：珠三角城市群中扩张迅速的城市主要分布在研究区中部的城镇密集带及沿海地区；扩张较慢的城市主要分布在靠内陆的周边地带。（3）基于时间尺度发现珠三角城市群结构的演变呈现出由单核模式（广州，1980年）-双核模式（广州、深圳，2000年）-多中心、网络化模式演化的特征（东莞、中山等相邻城市，2015年）。（4）基于景观格局特征，珠三角区域扩张快速的城市形状复杂，结构趋于分散；扩张较慢的城市形状更规则，分布更聚集。（5）天然的人文联系与优越的地理位置、社会经济、政府政策以及基础设施的建设等因素共同驱动珠三角城市群的发展。该研究对提高城市群规划管理水平具有参考价值。

Spatial and temporal characteristics of urban expansion in Pearl River Delta urban agglomeration from 1980 to 2015

This study takes 9 cities in the Pearl River Delta as the research object. Based on the land use data extracted from three remote sensing images from 1980 to 2015, the spatial and temporal variation characteristics of urban expansion on the Pearl River Delta urban agglomeration scale are quantitatively analyzed by the expansion intensity, expansion rate and landscape pattern index. The research results show that:(1) in terms of the characteristics of urban agglomeration expansion, it is found that the area of urban land in the Pearl River Delta continues to increase. From 1980 to 2015, the urban land area expanded nearly three times. During 1980-2000 and 2000-2015, it expanded by 1513.1 km² and 3043.8 km² respectively; the expansion rate of urban land was significantly accelerated, and the expansion intensity continued to increase. (2) Based on the time scale:in 1980, the Pearl River Delta Urban Agglomeration in Guangzhou as the center of the single core model; after 20 years of Reform and Opening-up, Shenzhen rose in 2000 and formed a dual core development mode with Guangzhou; after 15 years, by 2015, it gradually evolved from the dual core mode to the network and multi center mode, that is, Shenzhen and Dongguan, Guangzhou, and Foshan, Zhongshan and other cities developed together. (3) Through the comparative study on the expansion rate and expansion intensity of the urban built-up areas in the Pearl River Delta, it is found that:Based on the quantitative analysis, the expansion rate of other cities increased except Shenzhen and Zhuhai in 1980-2000 and 2000-2015; The characteristics of spatial distribution show that the cities with rapid expansion are mostly concentrated in the coastal areas where land resources are relatively scarce; the cities with relatively slow expansion are mostly concentrated in the inland areas where land resources are relatively abundant. (4) The analysis of landscape pattern shows that the urban land fragmentation is obvious, the spatial structure tends to be scattered, and the shape tends to be complex. At the same time, it is found that the rapidly expanding cities are more complex in shape and more dispersed in structure, while the slowly expanding cities are more regular in shape and more concentrated in distribution.In a word, the urbanization level can be reflected by studying the characteristics of urban expansion in the Pearl River Delta. Firstly, its natural factors determine the macro pattern of urban expansion. Secondly, policy factors (such as Reform and Opening-up and administrative division), and social-economic development factors (such as high overall level of export-oriented economy and reasonable industrial structure) jointly influence the expansion speed and direction of urban land. This is the main reason for the spatial-temporal difference of urban land expansion in the Pearl River Delta region, but it cannot completely control the development direction of urban land. On the whole, the development model of Pearl River Delta urban agglomeration is the result of many factors such as social, economic, policy and natural traffic conditions. This study provides reference value for improving the planning and management level of urban agglomeration.