Study on Dynamic Changes of Desertification in the Farming-pastoral Zone of the Northern Shaanxi Province

Integrating remote sensing (RS) with geographic information system (GIS), distribution digital maps of land desertification, spatial database and their statistics in the year of 1986, 1993 and 2000 were obtained by correcting, amplifying and auto classifying the RS images of interlaced zone for agriculture and animal husbandry in northern Shaanxi. The results showed that in the last 15 years desertified land area expanded and desertification degree reduced. The area of land desertification increased 5.09% which was worsened. While the land of serious desertification was diminished by a big margin which decreased 26.48%. Moderate and light desertification was increased. The spatial and temporal changes of desertification were complicated due to cultivated land desertification, which contributed 55.36% of total changed area, and forest land degradation, which contributed 25.72% of total changed area. Fundamental farmland constriction and ecological natural recovery reversed the land of desertification. Although the regional land desertification has been under control, but the land ecosystem is so fragile that desertification is liable to occur. The rising number of people and livestock and social economic development has been the primary elements that cause desertification.