关键词: 建成区空间扩展, 夜间灯光影像, 中心城市, 动力因子, 灰色关联分析, 黄河流域

Abstract:

The study on the expansion characteristics of built-up area of central cities in the Yellow River Basin is helpful to deeply understand the effect of land development and carry out the high-quality development planning of the central cities. Based on the night-time light images and statistical data in 1992， 1997， 2002， 2007， 2012 and 2018， the built-up area is extracted， and the expansion intensity index， compactness index， coordinated development coefficient and grey correlation analysis are used to explore the spatio-temporal pattern， quality and dynamic factors of the expansion of 8 central cities in the Yellow River Basin from 1992 to 2018. The results show that： （1） The built-up area of the central cities in the Yellow River Basin is different obviously， the expansion scale and intensity of cities in the middle and lower reaches are large， and the extended form presents a general downward trend of compactness. （2） The comprehensive level of Xi'an built-up area depicted by night-time light data is high， the level of Xining is low， the comprehensive development speed of Yinchuan is fast， and the speed of Lanzhou is slow. Except Xining， Hohhot and Taiyuan， the average night-time light index of other central cities shows a downward trend from 1997 to 2018， reflecting the decline of urban expansion level. （3） The coordinated development coefficients of population-land in central cities all showed a fluctuating and downward trend， with the exception of Hohhot， Taiyuan and Jinan， and most of them changed from the basic coordination type of population-land to the type of over-rapid expansion of land. The coordinated development coefficient of economy-land in the central cities shows a fluctuating downward trend， the average annual economic growth rate decreases， and the average annual expansion rate of built-up area increases， which basically changes from excessive economic growth to economic-land coordinated development. （4） The spatial expansion of the central cities is mainly affected by economic development. From the perspective of the central cities as a whole， the influence of administrative power and endogenous force is higher in the whole period （1996-2018）， the influence coefficient of administrative power is higher in three stages （1996-2002， 2002-2012 and 2012-2018）， and the influence degree of market power and export-oriented force increase obviously with time. In future， the central cities in the Yellow River Basin should be concerned about internal quality improvement and efficiency， strengthen the efficiency of construction land use， and promote high-quality urban development.

Key words: spatial expansion of built-up area, night-time light images, central cities, power factor, grey relational analysis, Yellow River Basin