哈长城市群城镇用地扩展进程及其驱动因素研究

以Landsat TM/ETM+/OLI遥感影像为主要数据源,提取哈长城市群1990、2000、2010、2015 年4 个年份的建设用地信息,采用年均扩展指数、景观扩展指数、多距离空间聚类函数、空间分维度等对城镇用地扩展进程进行分析。结果表明,1990~2015年间,哈长城市群城镇用地增加57 321.47 hm²,增长率为21.05%,整体扩展强度呈上升趋势;空间扩展表现出以中心城市为核心的扩展模式,边缘式增长在各个时期均为主导增长方式;空间扩展聚集性总体表现出“先增强、后减弱”趋势,整体空间结构相对稳定。国家宏观政策、非农业GDP增量和第三产业GDP增量是影响哈长城市群城镇用地扩展的重要因素。GDP增量、非农业人口增量、第二产业GDP增量对城镇用地的扩展起阶段性作用;人均GDP增量与城市用地扩展相关性不显著。

Process and Driving Factors of Urban Land Expansion in Harbin-Changchun City Cluster

Harbin-Changchun city cluster plays a very important role in the implementation of the New Urbanization Plan of China (2014-2020). Development of Harbin-Changchun city cluster is an important step to implement the strategy of revitalizing Northeast China and promote the integration of regional economy. Based on Landsat TM/ETM+/OLI remote sensing imagery, information of urban land in Harbin-Changchun city cluster were extracted in 1990, 2000, 2010 and 2015 by object-oriented classification method. A variety of spatial analysis methods, including Expansion Intensity Index, Landscape Expansion Index, Multi-distance Spatial Clustering function, and Fractal Dimension were used to analyze the expansions of urban land in study area. Furthermore, combing with statistical data, we analyzed the driving factors influenced the expansion of Harbin-Changchun city cluster. 1) Total area of urban land increased by 57 321.47 hm² with growth rate of 21.05% from 1990 to 2015. Expansion intensity of urban land showed an upward trend in the last 25 years. Because the marginal growth was the dominant growth model, expansions intensity index of central cities were larger than that of secondary central cities, which led to an expansion pattern with the central city as the core. 2) The characteristics of urban land agglomeration showed the process of “increasing first then decreasing” according to analysis of Ripley’s function. Structure of Harbin-Changchun city cluster was stable relatively since 1990 according to the result of Fractal Dimension. 3) The analysis of driving factors showed that national macro policies played very import role in the expansion process of Harbin-Changchun city cluster during last 25 years. Effect bought by socio economic factors were also analyzed by Pearson Correlation Method, results indicating that non-agricultural GDP increments and third industry increments were important factors that affected the urban land expansion of Harbin-Changchun city cluster. Function on urban land expansion played by GDP increments, non-agricultural population increment, second industry increments has the stage characteristic. There is no significant correlation between per capita GDP increment and urban land expansion. For Harbin-Changchun city cluster, to optimize the overall structure of the city group, enhance the functions of key cities in the region, exert the role of the northern open door of Urban Agglomeration, and follow a more “smart” growth route were highlighted in the future development planning. In addition, the contradiction between the smaller population scale and faster economic development, the coordination between urban development and cultivated land protection, the optimization of the second industry and the third industry structure are all the problems that should be resolved to guarantee a stable and healthy development of Harbin- Changchun city cluster in the future.