The Status, Dynamic Characteristics And Causes Of Sandy Desertification In Inner Mongolia Autonomous Region During2000～2010

Sandy desertification is very serious in Inner Mongolia Autonomous Region, which spreads all over temperate desert regions and temperate grassland areas, located in northern China. In this study, the NDVI, vegetation coverage and net primary productivity of the Inner Mongolia from MODIS images are analysed for the desertification status and the dynamic between2000and2010. Moreover, influencing factors on the process, such as precipitation, the inter-annual variation of the surface temperature, population growth, the amount of pasturage and land use change, were also analyzed. Results of this study will provide scientific basis for desertification control and vegetation restoration in the future. The main conclusions are as follows:(1) The area of sandy desertification in Inner Mongolia is355826.94km2in2010. Among them, the area of desert and gobi is141458.06km2, extremely severe desertification is86194.13km2,severe desertification is121709.69km2,moderate desertification is4199.63km2,while light desertification is255.44km2. Desert,Gobi and extremely severe desertification are mainly distributed in Alex League and the core zones of other desert, meanwhile desertification degree decrease in areas far away from the core zones.(2) The total area of desertification in Inner Mongolia dropped by79792.50km2during2000-2010, with all different kinds of decrease for different degrees of desertification. The area of desert and gobi reduced by39924.50km2, and extremely severe desertification reduced by5353.38km2,28209.94km2for the severe desertification. Furthermore, the area of moderate desertification reduced by5936.44km2,and light desertification reduced by378.25km2. The vegetation situation of desertification area improved overall during these years, with a rise trend for49.57percent of the land in terms of vegetation coverage and62.53percent of the land in terms of net primary productivity.(3) There is an apparent improvement in the juncture of badain jaran desert, ulan buh desert and tengger desert, and their southeast edge. The vegetation significantly improved in the east of KuBuJi desert and in the middle of Mu Us Sandy land. Otindag Sandy Land has an slight improvement while the Horqin sandy land has an slight deterioration, overall. Besides, Hulun Buir Sandy land grow worse during2000～2005, then grow significantly better during2005-2010.(4) Precipitation presents an upward trend in the growing season during2000～2010covering94.66percent of Inner Mongolia desertification zone while land surface temperature presents a downward trend covering84.56percent of the zone, which has an positive effect on the vegetation recovery and environmental improvement.(5) Population and livestock production increased gradually from2000to2010in Inner Mongolia, and the population growth rate accelerated while livestock production decelerated. Desertification is apparently related to livestock production. With the growth of livestock production, desertification increased. On the contrary, desertification decreased in areas with the livestock production reduced.(6) Grassland degradation of the Inner Mongolia covers an area of10522.69km2, with35.68percent transforming into farmland and21.48percent into cities and towns. Increased farmland covers an area of3570.02km2and more than half of them are transformed by grassland. Increased urban land covers an area of3958.42km2and more than half of them are transformed by grassland, more than half of the rest is transformed by farmland. All of these land use changes caused the deterioration of desertification.