文章基本信息

标题：A new map of global urban extent from MODIS satellite data
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作者：A Schneider ; M A Friedl ; D Potere 等
期刊名称：Environmental Research Letters
印刷版ISSN：1748-9326
电子版ISSN：1748-9326
出版年度：2009
卷号：4
期号：4
页码：044003
DOI：10.1088/1748-9326/4/4/044003
语种：English
出版社：IOP Publishing Ltd
摘要：Although only a small percentage of global land cover, urban areas significantly alter climate, biogeochemistry, and hydrology at local, regional, and global scales. To understand the impact of urban areas on these processes, high quality, regularly updated information on the urban environment—including maps that monitor location and extent—is essential. Here we present results from efforts to map the global distribution of urban land use at 500 m spatial resolution using remotely sensed data from the Moderate Resolution Imaging Spectroradiometer (MODIS). Our approach uses a supervised decision tree classification algorithm that we process using region-specific parameters. An accuracy assessment based on sites from a stratified random sample of 140 cities shows that the new map has an overall accuracy of 93% (k = 0.65) at the pixel level and a high level of agreement at the city scale (R² = 0.90). Our results (available at http://sage.wisc.edu/urbanenvironment.html ) also reveal that the land footprint of cities occupies less than 0.5% of the Earth's total land area.