基于夜光影像数据的合肥市城市空间格局演变与空间关联测度研究

Evolution of Urban Spatial Pattern and Spatial Correlation Measurement of Hefei Based on Luminous Image Data

利用NPP/VIIRS夜光遥感影像构建合肥市2012—2020年长时间序列灯光影像集,结合动态阈值法提取各年度合肥市区内城市建成区,有效剥离出活跃度不足的城市空间,采用空间演变规模相关指数和城市重心迁移模型,探索合肥市城市空间格局演变的时空特征;并结合引力模型系统性分析合肥市都市圈内各城市社会经济区位度的时空变化趋势与合肥市空间格局演变的关系,为合肥未来城镇建设用地布局及合肥都市圈八大合作一体化建设提供定量化决策参考。结果表明:合肥市以主城区为中心向四周呈面状扩展,并结合主要交通干线向外延伸,点状城镇区域面积呈点状稳定增加;合肥市城市重心为往返迁移型,反映出不同时期城市发展建设侧重点的差异;合肥市年度新增城镇建成区与城市引力之间空间耦合关系基本较强;结合城市综合引力值,合肥都市圈的极化现象有所改善。

NPP/VIIRS noctilucent remote sensing image was used to construct the long time series light image set of Hefei from 2012 to 2020. Combined with the dynamic threshold method to extract the urban built-up areas in Hefei in each year, the urban space with insufficient activity is peeled off effectively, and the temporal and spatial characteristics of the evolution of urban spatial pattern in Hefei is explored by using the spatial evolution scale correlation index analysis and the urban center of gravity migration model;combined with the gravity model, the relationship between the spatial-temporal variation trend of social and economic location of each city in Hefei metropolitan area and the evolution of spatial pattern of Hefei is systematically analyzed, which provides quantitative decision-making reference for the future urban construction land layout of Hefei and the eight cooperative integrated construction of Hefei metropolitan area. The results show that Hefei expands in a polygonal shape on all sides with the main urban area as the center, and extends outward in combination with the main traffic arteries, and the point-like urban area develops steadily;the urban center of Hefei is round-trip migration, which reflects the focus of urban development and construction in different periods;the spatial coupling relationship between the annual newly added urban built-up areas and urban gravity in Hefei is basically strong;combined with the comprehensive gravity value of the city, the polarization phenomenon of Hefei metropolitan area has been improved.