基于夜间灯光数据的长株潭都市区建成空间演化
Built-Up Spatial Evolution of Changsha-Zhuzhou-Xiangtan Metro Area Based on Nighttime Light Data

长株潭都市区是长株潭城市群的核心区域，是国内较成熟的都市连绵区。研究利用1993~2017年夜间灯光数据进行建成空间扩张动态度、空间分布、重心变动、景观格局变化分析，揭示长株潭都市区建成空间扩张时空演变特征。结果表明：1) 长株潭都市区建成空间在1993~2017年间扩张整体呈现“减慢–加快–减慢”波动式增长发展，空间扩张从中心向外围扩散。2) 建成空间规模增长演化离散度表现为“向心–离散–向心”波动中保持稳定的态势。3) 长沙城市建设总体发展程度远超于株洲和湘潭，都市区建成空间分布整体呈现“南–北”格局，空间重心整体向西北方向转移。4) 都市区外围建成空间斑块形状不断复杂化，斑块数量不断增加，破碎化发展趋势明显；内部用地斑块相互融合，连通性增强。
Changsha-Zhuzhou-Xiangtan metro area is the core area of Changsha-Zhuzhou-Xiangtan urban agglomeration, which is a relatively mature urban continuous area in China. The study used the night light data from 1993 to 2017 to analyze the expansion dynamics, spatial distribution, center of gravity change, landscape pattern change of built-up space. It revealed the spatial-temporal evolution characteristics of the expansion of built-up space in the Changsha-Zhuzhou-Xiangtan metro area. The research finds that: 1) The expansion of built-up space in the Changsha-Zhuzhou- Xiangtan metro area showed a fluctuating growth pattern of “slowing-quickly-slowing down” during the period from 1993 to 2017, and the spatial expansion spread from the center to the periphery. 2) The spatial evolution dispersion of the scale growth of built-up space in the metropolitan area showed a stable trend in the fluctuation of “centripetal-discrete-centripetal”. 3) The overall development degree of urban construction in Changsha is much higher than that in Zhuzhou and Xiangtan. The spatial distribution of built-up space in the metropolitan area presents a “south-north” pattern. The overall spatial center of gravity shifted to the northwest. 4) The patch shape of built-up space in the periphery of the metropolitan area is becoming increasingly complex, the number of patches is increasing, and the fragmentation development trend is obvious; the internal patches of land merge with each other and the connectivity is enhanced.