Study on Wind Erosion and Changes of Sandy Land in Tibet

Based on the data of soil wind erosion intensity and the soil wind erosion dynamic index, the spatial analysis of soil wind erosion of Tibet is carried out. Using landsatTM images, the land use changes from 1990 to 2000 are studied. The result shows there is no obvious expansion of sandy land. The sandy land is shrinking, as is reflected with the expansion of forest. Human activities such planting the trees dedicate to the reduction of sandy land. To the geomorphological analysis of the wind erosion caused sandy desertification in Tibet, three kinds of process exist corresponding to three typical areas that have varied driving factors and different spatial distribution. Using the meteorological data, the climatic factor of sandy desertification is calculated and its spatialtemporal change is analyzed. The result shows that the northwest part of Tibet experiences more intensified wind erosion. From about 1970s to 1990s, the value of climatic factor in most part of the Tibet is decreasing sharply.