Vegetation Cover Variation And Its Relation With Meteorological Factors In Northern Part Of Xinjiang

It is very important and practical to study the theory of regional surface processto enhance the ecological environment development under the background of globalwarming. As a significant climate unit, Northern Xinjiang has independent climateand natural geographical conditions, consequently is a unique natural geographicalsystem different from other areas. It is efficient using the all-weather andmulti-temporal remote sensing data, and integrating spatial analysis techniques ofGIS to analyze the temporal and spatial characteristics of NDVI in northern Xinjiang,so as to understand the basic facts and the features of the variation of NDVI,whilethe coupling analysis with NDVI and regional climate is to take a step forward toexplore under the background of the climate change in northern Xinjiang.Forthese,the article mainly study the NDVI and temperature,precipitation in northernXinjiang,analyze the temporal and spatial characteristics of NDVI and the couplingfeatures from1982to2006based on GIS and RS. Vegetation index responding toclimate change, reveals the tendency of the global environmental change in northernXinjiang. Several conclusions were drawn from this paper as follows:(1) The inter-annual variation of NDVI in north part of Xinjiang during1999~2010: the linear trend of NDVI values is0.01/10a, which indicates that NDVIvalues have been increasing since21Century.(2) During1999~2010,the region that has NDVI values between0.1~0.2accounts for36.69%of the total area which takes up the largest area; the region withNDVI values between0.4-0.5, which are the greatest NDVI values, accounts for2.47%of the total area. NDVI value of the cultivated land had an increasing trend,while the NDVI of natural grassland, forest presented a declining trend. The regionswith significant decreasing trend in vegetation coverage are the grassland of Fuyun,Zhaosu, Nileke and part of the forest in Tianshan Mountain and Altai Mountain.(3) Since1999to2010，the precipitation and temperature in the northern part ofXinjiang had been fluctuating with an upward trend. The rate of the rising trend is 14mm/10a、0.6℃/10a, respectively. Among the four seasons, precipitation in springincreased most significantly and temperature in fall rose the fastest. In a word, theclimatic variation of these12years is characterized by warmness and moisture.(4) The response of vegetation index NDVI to climate variation in northern partof Xinjiang: both precipitation and temperature have positive correlation with NDVI.The correlation between precipitation and NDVI of northern part of Xinjiang isgreater, with a biased correlation coefficient of0.65, which has passed the test ofsignificance. The biased correlation coefficient between temperature and NDVI is0.3with a insignificant correlation.