基于DMSP-OLS夜间灯光数据的长江经济带城镇体系空间格局演变（1992～2013）

研究长江经济带城镇体系空间格局演变，对于透视长江经济带城镇体系空间格局演变特征和规律以及促进长江经济带城镇体系空间格局优化发展有着重要意义。利用多时相同期Landsat卫星数据以及运用聚类分析方法对长江经济带夜间灯光数据进行校正，并采用其他辅助数据法对比分析获取城镇建成区面积的阈值，在此阈值基础之上选取景观总面积、总斑块数量和聚集度指数等总共8个典型景观格局指标, 继而使用FRAG-STATS 4.2 软件对1992~2013年间长江经济带城镇发展的空间格局变化进行计算分析。研究结果表明：(1）1992~2013年间，长江经济带城镇化快速扩展，城镇建成区面积增加了9.68倍，斑块数量增加了2.39倍，斑块密度也得到较大的增加，反映出长江经济带城镇数量不断增加和城镇建成区面积不断扩大；（2）景观斑块形状复杂度逐渐上升，中小城市不断壮大，同时出现了较多的新兴小城镇，总边界长度和平均边界密度的年均增长速度分别为21.56%和21.58%，体现了长江经济带城镇间聚集度越来越高，相互影响也越来越大；(3）最大斑块指数和聚集度指数两个指标在整体上呈现出逐年下降的态势，但是景观总面积、总斑块数量和斑块密度等8个指标在演变过程中均存在一定的波动和无序化，反映出长江经济带在城镇化过程中呈现出不规则和无序化的特征。

Spatial Pattern Evolution of Urban System in Yangtze River Economic Belt Based on DMSP-OLS Night Light Data (1992-2013)

Study on the spatial pattern evolution of the urban system in the Yangtze River economic belt could be important to understand the characteristics and laws of the spatial structure of the Yangtze River economic belt, and to promote the optimal development of the urban system in the Yangtze River economic zone. In this paper, the night light data of the Yangtze River economic zone are corrected by using the Landsat satellite data and the clustering analysis method. The threshold of the urban built area is obtained by the comparison of auxiliary data. A total of eight typical landscape pattern indicators, such as the total area of the landscape, the total patch number and the aggregation index, are selected based on this threshold. Thereafter, the spatial pattern of urban development in Yangtze River economic zone from 1992 to 2013 are analyzed by using the FRAG-STATS 4.2 software. The results show that:（1）During the period from 1992 to 2013, the urbanization of the Yangtze River economic zone was rapid. The area of urban built-up area increased by 9.68 times, the number of patches increased by 2.39 times, and the patch density increased greatly. These revealed that the number of towns continue to increase and the urban areas continue to expand in the Yangtze River economic zone. (2）The complexity of the landscape patch shape gradually increased, and the small and medium-sized cities continue to grow. More small towns emerged, and the total length of the border and the average density of the average annual growth rate of 21.56% and 21.58%. Thesereflected that the degree of aggregation in Yangtze River Economic Zone was getting higher, and the mutual influence was getting bigger. （3）The two indexes of maximum plaque index and aggregation index show a declining trend on the whole. However, there are some fluctuations and disorder in the process of evolution, such as total area of landscape, total patch number and patch density. These reflect the irregular and disorder characteristics in the Yangtze River economic zone.