Temporal and spatial variation of normalized difference vegetation index and its influencing factors in Beijing

In this paper, we analyzed the spatio\|temporal variations of normalized difference vegetation index (NDVI) based on the 250 m MODIS data from 2001 to 2010 in Beijing. We also examined the drivers of such variations, mainly climate change and human activities. Vegetation cover changes had experienced two stages in Beijing: a declining phase with small fluctuations during 20012003 and an increasing phase during 20042010 There were some significant spatial differences of vegetation cover changes. The vegetation cover had obviously increased in north of Huairou, Miyun and the northeast of Yanqing districts. NDVI of forest also increased in Mentougou and Fangshan districts. However, the vegetation cover evidently decreased in Changping, Yanqing, Shunyi, Daxing and the east of Fangshan districts, around the center of the city. The results showed that the spatio\|temporal variations of vegetation cover were the results of climate change and human activities. The temperature and precipitation were increasing at a rate of 0409 ℃/10 years and 156 mm/year during the past 10 years in Beijing. The correlation between NDVI and precipitation was more obvious than temperature. The relationship between monthly NDVI and monthly climate factors was obvious during the study period. Human activities also played an important role in vegetation cover changes. There were some different impacts in vegetation cover changes by land cover change, improved agricultural production and vegetation construction.