Dynamic variation of grassland area and meteorological influence analysis in Barkol

Using consecutive 10 years EOS/MODIS data with 250 m resolution from 2003 to 2012 in Barkol, NDVI was calculated with Maximum Value Composite approach after pre-processing, geometry emendation. Based on the GIS, 10 years NDVI information was distilled using the Land type classification map of Barkol with the scale of 1∶250 000 and the dynamic variety of NDVI was achieved during this consecutive 10 years with 2003 as background. The results showed that the area of high vegetation coverage grassland was relatively stable in Barkol and the annual amplitude area of middle vegetation coverage grassland varied obviously. If the area of low vegetation coverage grassland rise and that of the desertification grassland will fall and vice versa which showed that there was conversion relationship between them. If there was enough water, desertification grassland will transform to low vegetation coverage grassland and vice versa. Precipitation and temperature were two key factors for grass growth in Barkol, especially the precipitation from April to June.