基于OBIA的武汉城市圈1990年～2015年建设用地变化检测及时空特征分析

武汉城市圈是国家中部崛起战略和“两型社会”建设的重要支撑点，研究其建设用地扩张规律对区域城市规划及国家和区域经济发展政策的制定实施具有重要意义.该文以1990年～2015年的Landsat TM/OLI遥感影像为数据源，采用面向对象的影像分析 (Object-Based Image Analysis， OBIA) 方法提取了武汉城市圈的建设用地信息，并用扩张面积、速度、强度以及紧凑度等指数分析了建设用地扩张的时空特征.结果显示：1)利用多种指数及SPM自动确定分类阈值，能较好地提取建设用地，分类总精度为94.3%；2)武汉城市圈建设用地呈逐步增加趋势，总扩张面积约251 893.96 hm2，前10 a(1990年～2000年)扩张缓慢，后15 a(2000年～2015年)的扩张面积、速度、强度分别是前10 a的6.98、4.08和4.65倍；3)各城市建设用地面积在1990年～2015年均呈上升发展趋势，各城市的空间形态呈现由北向南、由西向东趋于紧凑型的发展态势.

Object-based image analysis change detection and temporal-spatial variation on construction land of Wuhan Metropolitan Area from 1990 to 2015

Wuhan Metropolitan Area is an important point of the strategy of the rise of Central China and one of the earliest comprehensive reform testing areas for national resource-saving and environment-friendly society building. The study of the rule of construction land sprawl in Wuhan Metropolitan Area is of great significance for regional urban planning and policy implementation on national and regional economic development. With the Landsat TM/OLI Remote Sensing Images in 1990-2015 as data source， construction land information is extracted by object-based image analysis method. The temporal-spatial differentiation characteristics on construction land are analyzed by using expansion area， expansion speed index， expansion intensity index and compactness index. The results are as follows. 1) The useage of multiple index and automatically classification threshold by Salford Predictive Modeler is able to better extract the construction land information， with the overall accuracy of 94.3%. 2) The construction land expansion area in Wuhan Metropolitan Area has been gradually increased from 1990 to 2015， with the total expansion area of 251 893.96 hm2. The expansion of the earlier 10 years (1990－2000) is slow， and the expansion area， speed and intensity of the later 15 years (2000－2015) are 6.98， 4.08 and 4.65 times of that of the earlier 10 years， respectively. 3) The construction land sprawl area in every city showed an ascendant trend from 1990 to 2015. From north to south and west to east， the space form in every city changed to be more and more compact.