近21a来京津冀城市发展空间特征及其与宏观地貌的关系分析

Spatial Characteristics of Urban Development and Its Correlation with Macro Geomorphology in Beijing-Tianjin-Hebei Region for Recent 21 Years

基于全国1:100万数字地貌数据库和1992-2012年的DMSP/OLS夜间灯光数据,从城市重心迁移变化、城市内部变异度和城市相对发展速率3方面,对近21 a来京津冀城市发展的空间特征,以及不同宏观地貌下城市发展的差异性进行了对比分析。结果表明:1992-2012年京津冀重心迁移方向大致经历西南-东北-西南3个阶段,不同城市重心迁移的轨迹和方向不同;京津冀整体发展水平不断提高,各城市间的差距呈减小趋势;不同地貌类型城市,其城市内部各辖区间的差异随时间变化的规律不同,平原型城市基本稳定不变,山地-平原型或平原-山地型城市有所下降,山地型城市各辖区间的差异随时间大幅减小;山地型城市相比其他地貌类型城市,城市重心偏移明显,城市整体发展水平较低。最后讨论了长时间序列下,城市发展与地貌间存在关联性。

Confirming the existence of spatial differences among different parts of urban areas, based on the 1：1million digital geomorphic database and DMSP/OLS nighttime light data from 1992 to 2012, we explored the spatial characteristics of urban development in Beijing- Tianjin- Hebei region for recent 21 years, including the change of urban barycenter migration, the development difference of internal urban area and the relative development rate. Besides, we compared the development difference of urban areas among different macro- scale geomorphologies. The results show that： the barycenter of Beijing- Tianjin- Hebei region has moved south- west,north-east and south-west in sequence, and different cities have different barycenter migration routes and directions; the development level of Beijing- Tianjin- Hebei region has been steadily increasing, while the disparities between cities in this region have been reduced; for cities with different types of geomorphologies, the disparities between their own municipal districts have different changing patterns over time. For plain cities, the disparity basically keeps stable; for mountainous-plain or plain-mountainous cities, an implicit downtrend is indicated;and for mountainous cities, the disparity between their municipal districts declines gradually. The migration of mountainous cities＇ urban barycenter is more obvious than cities dominated by other geomorphologic types, but these cities have an overall low development level. At last, we discussed the advantages of using DMSP/OLS nighttime light data, with the premise that heterogeneity exists in each city. We also pointed out that with regard to a long time series, there is evident relevance between urban development and urban geomorphology. A deep investigation into the relevance between the spatial characteristics of urban development and urban geomorphology is significant to understand the nationwide changes of urban development.