Remote sensing survey of surface water environment in urban areas: cases in Beijing, Kunming, and Wuhan

The TM data of Beijing areas acquired on October 31, 2000 has been selected and the ETM data acquired on February 18, 2003. We take the images of Beijing city and the surrounding area in 2000 for example to compare the single band threshold method with Spectral Relations method and the Water Index for measuring surface water. The result shows that the Spectral Relations method is more effective than the other two methods in removing false water information in urban areas. And we use the same method to extract water information from the data of 2003, then obtain water dynamic change information in these three years. Using the density segmentation of water depth in Guanting Reservoir to estimate the Reservoir storage capacity. The Water pollution situation of the Dianchi Lake in Kunming and the Donghu in Wuhan has analyzed by using ETM data.