Spectral Mixture Analysis of Impervious Surface in Changchun, China Based on Normalized Image

Vegetation-Impervious surface-Soil (V-I-S) model is a widely used model in analyzing the urban surface composition. Impervious surface which is a major component of V-I-S model is one of the important factors affecting urban ecological environment and residential quality. In this paper, taking Land sat TM image as data source, the distribution information of impervious surface of Changchun, China was obtained by spectral unmixing analysis. In the process of study, it was discovered that the spectra of different impervious surfaces had great differences, and the shade and shadow also significantly influenced estimation accuracy. In order to solve these problems, the method of spectrum brightness normalization was utilized. As a result, the differences within impervious surfaces had decreased obviously, while the differences between impervious surface and other land cover types had increased. It is more convenient to extract the impervious surface information. Then the impervious surface fraction image together with vegetation and soil fraction image was gained by using linear spectral unmixing analysis. Accuracy validation shows that the result is reasonable. Finally, post analysis was carried out on the basis of zonal statistics method and the potential residential areas data got from urban master planning map of Changchun (1996-2020).