Abstract: This paper studied the spatiotemporal variations of normalized difference vegetation index (NDVI) in Zhejiang Province in 1982-2006, and their relations to the dominant eco-climatic factors in the Province. In the study period, the vegetation cover in the Province had a slowly decreasing trend, and the area with a significant decrease of NDVI occupied 30.71% of the total. There were significant relationships between the eco-climatic indices and the NDVI of the following year. The NDVI was significantly positively correlated with biological aridity/humidity index, and significantly negatively correlated with biological warmth index, suggesting that the increase of humidity could promote vegetation growth, while excessive heat could inhibit the vegetation growth in the study area.

Key words: normalized difference vegetation index, biological warmth index, biological aridity/humidity index, time-lag effect, soil wetting pattern, soil temperature, soil matrix suction, root distribution, root water consumption, cotton., drip irrigation