Researching the Relationship between Vegetation Cover Change and Debris Flow Activity Based on GIS and RS

To investigate the relationship between vegetation cover change and debris flow activity, we conducted an experiment in the Minjiang River from 2000 to 2008 year. Researching time was divided into 4 periods and image acquisition time as the division point. The vegetation index change rate of the vegetation cover and the frequency of debris flow activity were acquired respectively for the four periods. The inverse law was found that the frequency of debris flow activity and the change rate of the vegetation index. When vegetation cover increases, the frequency of debris flow activity reduces; when the vegetation index reduces, the frequency of debris flow activity increases.