Abstract: Changes of climate factors in the Qaidam Basin during 1981-2010 were analyzed based on the monthly temperature and precipitation data from meteorological stations. Rate of linear tendency and Mann-Kendall test were used to illustrate the change trends and detect abrupt changes of meteorological elements respectively. In addition, lake area changes and vegetation activity changes in the Qaidam Basin in response to climate changes were discussed using Landsat TM/ETM+ images, NOAA/AVHRR-NDVI and EOS/MODIS-NDVI products. The results showed that (1) The Qaidam Basin experienced an overall rise in temperature, especially in autumn and winter during 1981-2010. Temperature changed abruptly from low to high in 1987 and the increase has become more rapid since 1998. (2) The annual available precipitation showed a "decrease-increase-decrease-increase" change in recent 30 years, but the inter-annual trend of annual available precipitation was similar to annual mean temperature at a rate of 5.65 mm/10a. Available precipitations were low in 1981-1985, 1990-2001, but high in 1985-1990, 2001-2010. An abrupt change to warm-wet happened in the mid-late 1980s. However, an overall trend of warm-dry was detected from the mid-1990s to the end of the 20th century. A significant warm-wet trend of climate has arrived once again since the early 21th century. (3) Variations of lake area and vegetation growth were significantly affected by the change of wet and dry climate. The "expansion-atrophy-expansion" pattern in lake areas correlated with summer available precipitations which happened in 1985-1990, 1990-2001, 2001-2010 respectively. (4) The "degradation-amelioration-degradation-amelioration" pattern in vegetation growth was closely related with growing season available precipitation which happened in 1981-1985, 1985-1990, 1990-2001, 2001-2010.

Key words: climatic factors, lake area, the Qaidam Basin, vegetation growth