Desertification monitoring by LANDSAT TM satellite imagery

The desertification tendency of the Qubqi Desert in China for 10 years was investigated using vegetation and soil change indices extracted from seven LANDSAT TM images. To identify the desertification tendency, two methods were applied. In the first, the desertification extent and tendency were determined by classifying the land cover into the following four categories using the Normalized Difference Vegetation Index (NDVI): floating desert area, half-fixed sand area, fixed sand area, and grassland. In the second, the degree of desertification was classified using the Modified Soil Adjusted Vegetation Index (MSAVI): primitive state, latent state, slight desertification, medium desertification, and high-degree desertification. The study results demonstrated that expansion of desertification was mostly clear in the eastern Qubqi and the neighboring farming land area.