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以NCEP/NCAR所发布的1950~1979年全球海平面温度(SST)数据为基础,得到了1980~2006年ENSO事件的3个典型阶段,即冷阶段、中性阶段和暖阶段。通过分析1982~2005年的NOAA-AVHRR NDVI影像数据,得到了在不同ENSO阶段青藏高原生长季(5~9月)和冬季(12~2月)的NDVI平均值和离差图。结果表明:在生长季,冷阶段的NDVI高于其他两个阶段;在冬季,高原上的NDVI在正常阶段最好,其次为暖阶段,在冷阶段生长状况最低。此外还发现,不同阶段的青藏高原北部和南部植被变化也存在明显差异。
Based on the data of global sea level temperature (SST) from 1950 to 1979 published by NCEP / NCAR, three typical phases of ENSO events from 1980 to 2006 were obtained: cold stage, neutral stage and warm stage. By analyzing the NOAA-AVHRR NDVI image data from 1982 to 2005, the NDVI mean and variance plots of the Tibetan Plateau during the growing season (May-September) and winter (December-February) at different ENSO stages were obtained. The results showed that in the growing season, the NDVI in the cold stage was higher than that in the other two stages. In winter, the NDVI in the plateau was the best in the normal stage, followed by the warm stage and lowest in the cold stage. In addition, there are also significant differences in the vegetation changes in the northern and southern parts of the Qinghai-Tibet Plateau in different stages.