Research Of Driving Factors To Vegetation Dynamics Of Loess Plateau From 2000 To 2013

The vegetation coverage can partly show the structure and function of ecological system. The vegetation cover change are influenced by climate change, human activity and atmospheric fertilization, explore the mechanism of vegetation cover with three facto rs as an important part of the ecological system. That is so important for recovering a nd protecting of ecological environment, and improving the relationship between human and nature. The Loess Plateau is an important area for protection of soil erosion and v egetation recovery. The study on the future of ecological environment construction is gr eat significant for Loess Plateau. This paper mainly used EOS MODIS NDVI 250m data set and weather data which got from the 189 weather stations in the surrounding are a of Loess Plateau and included of the temperature and precipitation. Analysing of ch aracteristics of temporal and spatial variation for vegetation cover and climate factors i n the Loess Plateau. And then using the M_RESTREND method to distinguish the co ntribution rate of human activities, climate change and atmospheric fertilization on the vegetation cover change. M_RESTREND method is based on RESTREND method and considering the effect of vegetation cover change which is affected by the atmospheri c fertilization. And then distinguishing the human activities and atmospheric fertilizatio n from non-effect of climate which should make quantitative analysis, the main conclu sions are as followed:(1)The NDVI of vegetation in Loess Plateau region showed a decreasing trend from southeast to northwest, and the difference of spatial distribution.(2)The annual NDVI showed an overall upward trend and the volatility during the research period, and the rising degree was smaller. The spatial difference of NDVI change trend was significant, and was not the same in different regions.(3)Precipitation showed increasing trend in the whole study period, but the significance was not strong, and there was a certain volatility. The precipitation also showed a decreasing trend from southeast to northwest, and showed the typical ladder like distribution, the annual variation was not same in difference region. The region’s precipitation and vegetation cover change as a positive correlation, negative correlation exists in some local areas.(4)Under the background of global warming, the Loess Plateau temperature decreased from southeast to northwest, the spatial distribution of temperature and annual variation of temperature were difference, and the correlation with vegetation cover change was not high, and had negative correlation, that meant the temperature didn’t limit the growth of vegetation.(5) The rate of vegetation cover change caused by driving factors and human activity had similar spatial distribution, it means the human activity controlled the spatial pattern of vegetation cover change in the Loess Plateau.(6) The vegetation growth area of human activity contribution rate closed to 50%, further explained the positive effect of human activity in the vegetation growth area was stronger, and the conversion of cropland to forest, soil and water conservation and other related to the implementation of major ecological engineering that related to the implementation of major ecological engineering, such as restore the reclaimed land to forests and conservation of water and soil...