| The meteorological data collected in 19612004 was used to analyze annual and seasonal patterns and characteristics of the climatic changes in east Haixi and the regions around Qingghai Lake. The results showed that in recent forty years, the average seasonal temperature had increased by 0.20.6℃ with its highest and lowest values increasing in a asymmetric manner in most cases, and remarkable temperature increase took place in all the four seasons in 1990's; The rainfall had slightly increased in summer and winter but generally tended to decline in the transforming seasons. The annual, autumn, winter and spring and summer temperatures all had varied with their positive tendency rates at 0.48,0.57,0.629,0.337,0.373℃/10a. The winter and summer rainfalls had varied with the tendency rates at 0.442 and 4.672 mm/10a but the autumn and spring rainfalls had changed with their tendency rates at -2.304 and -0.022 mm/10a. The slow increases of rainfall and snow in winter were very liable to lead to snow accumulation on ground surface and then snow damage or low temperature and freezing damages. in spring, the drought frequency increased because the temperature rose and the rainfall declined,; the big increases in temperature were beneficial for insects and pathogens to overwinter and reproduce thereby intensifying their damage to farming and animal raising. |