2000～2014年武汉市城市扩展时空特征分析

ANALYSIS OF SPATIAL AND TEMPORAL CHARACTERISTICS OF URBAN EXPANSION ABOUT WUHAN CITY IN THE YEAR OF 2000–2014

基于不同时相的高分辨率遥感影像,采用面向对象的解译方法提取了武汉市2000、2005、2010和2014年的土地覆被信息,从城市扩展强度指数,城市中心坐标迁移和分形维数等方面分析了武汉市2000～2014年城市扩展时空特征。结果表明：2000～2014年间,武汉市城市扩展强度指数为1.41,各主城区城市扩展强度不一,洪山区建设用地的增加对主城区城市扩展的贡献最大;在扩展过程中,武汉市城市分形维数增加,城市空间形态变复杂;其扩展呈现核心-放射扩展模式,并逐渐转向圈层式;自然条件、经济、人口、交通、政策和城市规划是武汉市城市扩展的主要驱动力,但随着交通的发展,自然条件和经济对武汉市城市扩展的驱动作用正逐渐减弱。

Wuhan city has developed rapidly since the 21 st century, and the urban area is increasing. With high-resolution remote sensing images at different phases and object-oriented methods of interpretation, we derived the land cover map of Wuhan city in 2000, 2005, 2010 and 2014. And the spatial and temporal characteristics of Wuhan urban expansion have been analyzed in terms of urban expansion intensity index（UII）, the city center coordinates and fractal dimension. It showed that the UII of Wuhan city was 1.41 in 2000–2014, and the annual growth rate of construction land reached 10.7%; The annual growth rate of non-core urban construction land was 20.3%, much larger than the main city; And each central district had different UII in 2000–2014, the UII of Qiaokou District was 2.01 while that of Wuchang District was only 0.54.The construction land area of Hongshan District increased 112 km2 which was significantly higher than other main city in2000–2014 years, its urban expansion area accounted for 59.2% in urban expansion area of the main city, so the largest contribution to urban expansion of the main city was the growth of construction land in Hongshan District; With the expansion of Wuhan city, the fractal dimension of Wuhan City increased in 2000–2014, suggesting that urban spatial morphology became complicated, and the impact on urban form of urban interior renovation was greater than the city extended outward in 2010–2014, but the urban form of Wuhan city is still in instability; In 2000–2005 years, the form of urban expansion in Wuhan city was ＂cone-shaped＂, and the form of urban expansion in Wuhan city was ＂plume＂ in2005–2010 years while the form of urban expansion in Wuhan city was ＂massive＂ in 2010–2014 years; The gap in different directions of urban expansion intensity in Wuhan city became smaller in 2000–2014, and the extended mode of Wuhan city was core-radial in general, but it is gradually turning circle formula expanded configuration and Wuchang District and Jianghan District are turning content-type. At last, natural conditions, economic development, population growth,transportation facilities, policy and urban planning were the main driving forces of Wuhan city＇s expansion in 2000–2014years, and transportation facilities had the largest driving forces while the population growth had a greater impact on urban expansion than the economic development. With the construction of transport facilities, the effect of natural conditions and economic development to urban expansion in Wuhan city is gradually weakened, but the policy and urban planning still determine the general direction of urban expansion of Wuhan city.