Characteristics of Vegetation Cover Change in Xinjiang Based on NDVI

The vegetation ecosystem in Xinjiang is fragile,which is the key area for long-term protection and attention.With the help of GEE platform,the normalized vegetation index（NDVI）data provided by NASA were obtained,and the spatial-temporal changes and future trends of vegetation cover in Xinjiang during the growing season（April to October）from 2000to 2021were studied by means of means method,difference method,trend analysis method,stability analysis method,Hurst index and other methods.The results showed that,1)the vegetation coverage in Xinjiang showed a slight increase at the rate of 0.001 4each year in the past 22years,with a higher spatial distribution in the north and northwest and a lower spatial distribution in the south and southeast.2)In Xinjiang,85.2%of the vegetation cover increased,while 14.8%of the vegetation cover decreased.The vegetation cover increased significantly in Tacheng Area,Yili Kazak Autonomous Prefecture,northern Bayingolin Mongolian Autonomous Prefecture and the oases around the basin.The significant decrease was found in Shihezi,Urumqi,Kashgar,Hotan,etc.3)In recent 22years,the vegetation coverage in Xinjiang fluctuates significantly.The average hurst index is 0.44,indicating strong reverse persistence.Therefore,ecological restoration and protection of vegetation should be further strengthened in the future.