经济转型背景下长三角城市用地扩张及影响因素的时空差异

研究全球化、市场化和分权化等因素对长三角城市用地扩张的影响,对于在经济转型背景下促进长三角区域协调发展具有重要意义。利用城市用地扩张差异指数和强度指数分析了2001—2015年长三角城市用地扩张的热点区域及各城市的城市用地扩张时序变化,并通过时空加权回归模型对不同驱动力作用的时空差异进行研究。结果表明：（1）长三角城市用地扩张具有空间集中性及阶段性特征,苏锡常等都市圈是城市用地扩张的热点地区,随着协同水平的提升,区域内城市发展状态差距逐渐缩小。（2）研究期间长三角城市用地扩张强度在整体和个体上均呈上升趋势,扩张强度平均值大致呈以上海为中心向外围递减的圈层分布,外围城市的扩张强度以更为稳定和快速的状态在提升。（3）全球化、市场化和分权化均能较好地解释长三角城市用地的扩张,全球化是长三角城市发展的重要推动力,且存在明显的区域差异;上海、苏南和浙北地区市场化的发展对城市发展的推动显著,而后发地区需进一步激发市场改革红利;财政赤字是地方政府实行城市扩张策略的重要因素,但发展模式会随着发展水平的提升而改变。（4）控制变量上,经济发展的影响显著且较为平稳,人口也具有显著的推动作用且部分城市有加深趋势,固定资产投资的作用较为集中。

The spatio-temporal differentiation of urban land expansion and influencing factors in the Yangtze River Delta in the economic transition context

In order to promote the coordinated development of the Yangtze River Delta region in the economic transition context, it is of great significance to study the influence of globalization, marketization and decentralization on the expansion of urban land. In this paper, the difference index and the intensity index of urban land expansion are used to analyze the hot spots and each city's sequential variation of urban land expansion in the delta from 2001 to 2015, and the spatio-temporal differentiation of different driving forces' influence is studied by using geographically and temporally weighted regression model. The results show that: (1) In the study area, the urban land expansion has characteristics of spatial concentration in periods, and some areas such as Suzhou-Wuxi-Changzhou are the hot spots of urban land expansion. At the same time, the gap of developmental state of each city will be narrowed with the improvement of regional coordination level. (2) The urban land expansion intensity in the delta showed an upward trend on the whole and on the individual level during the study period, and the average urban land expansion intensity was roughly in line with the circle layer distribution with Shanghai as the center decreasing to the periphery, while the expansion intensity of the peripheral cities increased in a more stable and rapid state. (3) Globalization, marketization and decentralization can well explain the urban land expansion in the region. Globalization is an important driving force for urban development in the delta, and there are obvious regional differences. The development of marketization has significantly promoted the urban development in in Shanghai, South Jiangsu and North Zhejiang, while the developing regions need to further stimulate the dividends of market reform. The fiscal deficit is an important factor for the local governments to implement the strategy of urban expansion, but the development modes will change with the improvement of development level. (4) Among the control variables, the influence of economic development is significant and relatively stable; the population density also plays a significant role in promoting urban land expansion and its influence enhanced in some cities, while the effect of fixed asset investment is more concentrated.