Arid And Semi-arid Region Of NDVI And Influecing Factors Analysis Based On Remoting Sensing Data

Arid and semi-arid regions, mainly in the three north areas of northern China, is located in the inland, less rainfall, the regional ecological system type is complicated, complex structure and function, fragile ecological environment, is also affected by climate change that the most significant area. It determines the ecological environment of our country, even the national and global climate change and ecological environmental impact of a very important influence. In the west of Jilin province is a typical arid and semi-arid areas, which position is in the well-kown horqin desert belt east edge in China.The desertification land area is large and wide, covering and extension speed rapidly, is the worst area affected by desertification hazard. At the same time,in the west of Jilin province is China’s important commodity grain base with small grains, the change of the ecological environment in Jilin province and even the whole country has an important influence.Vegetation occupying the dominant position of ecosystem, is the foundation of the ecological system.It is a natural coupling of atmosphere, soil and water, that can be used as an important index to measure the degree of changes in the regional ecological environment, and the impact of climate change and human activities. In recent years, the rapid development of remote sensing technology, provides new means for monitoring vegetation dynamics, especially according to the long time serial remote sensing image monitoring vegetation dynamics becoming the focus of the vegetation ecosystem research problems. To the end, the paper choose the moderate resolution imaging spectroradiometer (MODIS) provided by the spatial resolution of 250 m,16 days in the synthesis of vegetation index (NDVI) data, analysis of the western region of Jilin province in 2000-2014 vegetation index change trend, what’s more,combining with the 18 countries in the west of Jilin province and its surrounding temperature and precipitation data of meteorological datum station, through a variety of time and space analysis method, analysis under different vegetation, climate and land which use zoning, vegetation index change trend of space and time for many years, the region and discusses arid and spatio-temporal coupling relationship between vegetation and climate change in arid areas, and human activities on the quantitative evaluation of the effect of changes in vegetation index in the region. Based on the analysis of above, the following results are obtained.From the vegetation index in the international change rule is summarized in west Jilin province vegetation growth cycle. In a recent decade, vegetation index, although the volatility but overall showed a trend of increase. From the trend of the four seasons change of vegetation index, vegetation in the activities of the spring and autumn in enhancement,calculation of each grid vegetation index and the correlation coefficient of time, which get the space variation of the vegetation index, found that vegetation index falling areas mainly concentrated in the expansion of desertification land areas. The trend of the analysis of the temperature and precipitation interannual variability and correlation between climatic data and NDVI, temperature and precipitation has certain influence to changes in vegetation index, but is not the only factor. From the relationship between climate and vegetation index data distribution, the positive correlation between vegetation index and regional climate data is "normal" phenomenon, instead present negative correlation area, show that the area is the human activity influenced factors more. Residual method is used to quantitatively estimate the influence of human activities on the changes in vegetation found that human activities on vegetation index in the region, which have a significant role in promoting regional area accounted for 37% of total area. All in all, under the effect of both climate and human activity, in Jilin province in the western region the vegetation index as a whole increased, vegetation showed a trend of better development.