干旱区生态环境知识资源中心

The northwest China, typical and and semi-arid regions, is the first or second-degree sensitivity zones for global change. Monitoring vegetation change is an important method to study the impacts of global climate change. Time-series satellite remote sensing data make it possible to monitor vegetation at different spatial and temporal resolutions globally. A long time series of Advanced Very High Resolution Radiometer (AVHRR) Normalized Difference Vegetation Index (NDVI) data with 8x8 km(2) spatial resolution and during 1982 to 2003 were used to monitor the vegetation cover in the northwest China. The monitoring results indicate an obvious greening trend exists. The precipitation and relative humidity have high correlations with the SINDVI. So the water condition is the most important factors for the spatial distribution of the SINDVI levels. The precipitation and temperature are the primary driving factors for inter-annual vegetation changes.