利用夜间灯光数据的武汉城市空间格局演化

Urban Spatial Pattern Evolution of Wuhan City Based on Nighttime Light

鉴于夜间灯光数据在市级尺度精度不足等问题,提出了一种基于NDVI修正的阈值提取法。在此基础上,采用空间扩展模式分析、景观格局指数、重心迁移模型方法,系统性分析近16年武汉市城市扩张时空特征,以期为武汉未来城镇建设用地布局及相关政策制定提供决策依据。研究结果表明,基于NDVI修正的阈值提取法,可用于地级市建成区提取及城市扩展研究;武汉城市扩张模式表现为以主城区为中心的面状发展为主,点状城镇发展所占比例相对较小,主要受黄陂区、新洲区的牵引;城镇发展经历了高度破碎化时期之后不断趋于集约化发展,破碎度逐步减小;武汉建成区重心移动幅度越来越大,城市化过程总体处于较快发展状态。

In view of the nighttime light data lack of precision in the municipal scale,this paper presents a threshold extraction based on normalized difference vegetation index（NDVI）.It systematically analyzes Wuhan urban expansion of spacetime characteristics nearly sixteen years to provide decision-making of future urban construction and the related policies by the method of space expansion pattern analysis,landscape pattern index,and the gravity model.Research conclusions of the article show that：The threshold extraction method based on NDVI correction can be used for the extraction of urban built-up area and urban expansion;the urban expansion pattern of Wuhan is mainly represented by the planar development of the main city area,and the proportion of the town development is relatively small,which is mainly affected by the traction of Huangpi district and Xinzhou District;the development of the city has experienced a high degree of fragmentation after the continuous intensive development,while fragmentation gradually reduced;the Wuhan center of gravity moves at a faster pace recently,and the urbanization process is in the rapid development state.