Analysis on karst rocky desertification in Guizhou based on "3S"

Rocky desertification is the result of unreasonable human activities on the fragile karst environment.The present state of rocky desertification in Guizhou province is analyzed according to remote sensing image and karst rocky desertification map is obtained through "3S" platform.The result shows there is 41 091 km2 rocky desertification land out of the total 113 158km2 karst area in Guizhou province,and it is the most severe rocky desertification area in Southwest China.The spatial distribution has the feature of more severe in west and south Guizhou but lighter in east and north area.By assaying the data of present and 2000 year's,it is found that the annual rate of karst rocky desertification change in Guizhou province is 2.88 percent,rocky desertification has continuously broaden and become more and more severe in the last five years.