干旱区生态环境知识资源中心

Ten-day series of the Normalized Difference Vegetation Index (NDVI) derived from multi-temporal satellite imagery (1998-2008) was employed as a surrogate for the surface vegetation cover to investigate synchronization of the climatic determinants and its spatial patterns in China. The results, both of the spatiotemporal patterns of joint probability of recurrence (JPR) index and lag time of maximal JPR, clearly suggest that the synchronous relationships of NDVI-climate are site specific and spatially heterogeneous. Higher JPR values of NDVI-temperature are found in Northern China, indicating stronger synchronization in these areas, while higher JPR values of NDVI-precipitation are found in semi-arid and semi-humid regions, which suggest that the moisture factor has a significant influence on NDVI in these areas. Whether lagged or advanced relationship, the phase difference of NDVI-temperature is smaller in Southern China, while is bigger in Northern China. In contrast, the phase difference of NDVI-precipitation is smaller in the semi-arid and sub-humid areas, which means that precipitation has a significant and immediate influence on vegetation in these areas. Overall, the JPR values for NDVI-temperature are higher than those for NDVI-precipitation, suggest that the synchronization between NDVI and temperature is stronger than that between NDVI and precipitation in most areas of China. The results indicate that joint recurrence quantification analysis is a good candidate method for identifying the synchronization between NDVI and climatic determinants.