Vegetation Coverage Change In Mu Us Sandy Land And Its Response To Climate Change

Climate change has become one of the world’s most serious environmental problems, and regional vegetation coverage changes can indicate climate change regularity. Therefore this study using remote sensing and GIS as spatial analysis technology, SPOT-VGT NDVI remote sensing data as the main information source, based on the pixel binary model extracts the information of vegetation coverage change. Also studies the process of vegetation coverage change using difference method and the trend analysis method in Mu Us sandy land in 2000-2013. Depending on this, makes the spatial correlation analysis between vegetation coverage change and the precipitation, temperature and aridity index, so as to discuss the variation characteristics of vegetation coverage in Mu Us sandy land and its response to climate change.The main results are as follows:(1) Most of the MU Us sandy land is in low coverage area and middle cover area, accounted for 33.6% and 37.5% of total area respectively; Followed by middle high coverage, extreme low coverage and high coverage, accounted for 21.2%,5.1%,2.5% of total area respectively. The main cover types in MU Us sandy land are typical steppe, farmland, desert, desert steppe, meadow, bush fallow and forests, accounted for 51.79%, 17.61%,10.01%,9.29%,6.31%,3.94%,0.89% of the total area respectively.(2) The Mu Us sandy land showed increasing trend of vegetation coverage as a whole during 2000-2013. From the perspective of the changing trend of vegetation coverage, improved area of vegetation coverage in Mu Us sandy land is larger than the degraded area of vegetation coverage, accounted for 37.9% and 35.39% of the total area respectively. The moderate improvement districts with the climbing speed of 0.016-0.021, and obviously improve area with of 0.021-0.046 in all accounted for 17.86% of total area. They distributed mainly in Hengshan cuouty, Jia cuonty, the northeast of Jingbian cuonty, and the east of Fugu county, Shenmu county,Yuyang county. And the area of moderate degradation and severe degradation are not very large, accounting for 11.53% of the total area. From the perspective of the change of seasons, the change of vegetation coverage in four seasons is obviously, especially the vegetation coverage in summer, it fluctuated between 25% and 40%. Followed by autumn and spring, and the vegetation in winter is the lowest. From the point of vegetation types, expect for forests, the rest of coverage types were increasing as the change of time, and the vegetation coverage of farmland and bush fallow are larger, and the increasing speed of bush fallow is most quick.(3) The temperature, precipitation and aridity index in Mu Us sandy land rise gradually during 2000-2013. But most closely correlation with precipitation. In different seasons, the vegetation coverage is different on the response to the temperature and precipitation. In the spring, the change of vegetation coverage is greatly influenced by the temperature, increasing with temperatures rising. And for summer and autumn, the precipitation is the restriction factor to vegetation coverage. With the precipitation increasing, the vegetation coverage can significantly increase. In winter, vegetation coverage has significant negatively correlation with precipitation, and significant positive correlation with temperature. For different types of coverage, the response of vegetation coverage to rainfall and temperature was different, and the typical grassland are in significant positive correlation between the precipitation and temperature.