Extracting impervious surface area and discussing urban expansion of Guangzhou (1990-2003) based on V-I-S model by using linear spectral mixture analysis method

In China, urban expansion experiences different periods during the last two decades with a rapid development rate and with different patterns among the interior and exterior of a city. The object of this paper is to discuss the changes of impervious surface in Guangzhou from 1990 to 2003 by using the V-I-S model under the support of technique of sub-pixel. Two Landsat image data (TM, 1990 and ETM+, 2003) are used to demonstrate the usefulness of the V-I-S model. And the impervious surface (IS) data is extracting using the linear un-mixing analysis model. Base on these two IS data, the spatial expansion pattern of Guangzhou city is discussed. This paper gives a case study to understand urban expansion with the view of IS not a traditional view of land use. The results showed that the V-I-S model could express the information of urban expansion, and is useful to discuss the transformed information of impervious surface of interior urban. From 1990 to 2003, Guangzhou had experiencing a rapid urbanization and development, especially the developing direction has changed obviously in past 15 years. Based on the data of IS of Guangzhou in 1990 and 2003, the change results are shown as followed: (1) the mean value of IS increases one times from 0.21 to 0.67; (2) the direction of urban expansion is multidimensional, almost reflecting North and East direction;(3) the density of IS in inner city increases during this periods with the fast economic development.