GORS 14 - 2 Sensitivity of Normalized Difference Vegetation Index (NDVI) to Seasonal and Interannual Climate Conditions in China

Abstract

Abstract: Lagged correlation analysis and statistical analysis were used to investigate the relationships between NDVI and climate factors (temperature and precipitation) in six climatic zones of China, and also investigate the relationships between NDVI and climate conditions in different sub-regions. The results show that there are positive correlations between NDVI and climatic factors in most zones of China; and the more significant correlations occur in three zones (Plateau climate zone, Warm-temperate zone and Mid-temperate zone). Both of the temperature and precipitation are important to the vegetation change in all zones, but the temperature influence is slightly larger than the precipitation; while precipitation plays key role in Plateau climate zone. The highest correlation between NDVI and temperature with value 0.929 occurs in subtropical zone; while the highest correlation between NDVI and precipitation with value 0.889 occurs in Mid-temperate zone, which indicates the sensitivity of vegetation cover to precipitation in the arid and semi-arid zones of north China. In different sub-regions, temperature and precipitation play an important role to the changes of vegetation cover especially in low mountain area (200-1000m). The temperature dominates in most of sub-regions while precipitation plays a more important role in high mountainous area (>3000m) as in Plateau climate zone. Furthermore, the time series of NDVI demonstrate a positive trend from 1982 to 2001, which means that the vegetation biomass present on land surface is increasing. This trend is strongly correlated to increased precipitation and temperature from 1982 to 2001.