A Study of Spatio-temporal Variation Of Vegetation by Using SPOT NDVI Images in Aba, China

In this paper, SPOT NDVI images from 1998 to 2013 were used to estimate the spatial-temporal variation of the vegetation in Aba, China. The results showed that the average value was 0.383 and monthly changed from 0.222 to 0.623 during recent 15 years, and the value of NDVI reached a peak in August. The total vegetation coverage was increasing year by year in the study area, and the 56.83% of the research area was improved. The degradation regions were located in the southern areas. The vegetations of Xiaojin and Wenchuan were seriously degraded and the wetland in Zoigê plateau presented some degradation, which might result from grazing.