关键词: 伊犁地区, 气候特征, 干-湿变化

Abstract: This paper has analyzed the characteristics of the climatic changes based on the current meteorology data in the recent 40 years of 9 meteorological stations in Yili area. Through 5 tree ring chronology series, the 314 year precipitation was well reconstructed and its explain variance was 75%. The paper also has com pared th e features of climatic changes in Yili with the neighboring areas(the other area s of Xinjiang, Gansu, Qinhai provinces, China and Central Asia), and obtained some beneficial results as follows: (1) Maximum entropy spectrum analysis showed that annual temperature change had 2, 4.25 and 10~11 years significant periodicity in recent 35 years. The re was an evident warming tendency from 1953 to 1995, and the rising rate of mean annual temperature was 0.28℃/10a. Contrast to the annual temperature, the magnitude of winter temperature increase was larger in recent 25 years. Th e rising rate reached 1.6℃/10a that is as 4.7 times as that of th e annual. The change is consistent with those of other areas of China and Northern Hemisphere in rec ent decades. That is the temperature of Yili area responded to the global change better. (2) The precipitation of annual and seasons in Yili area has better correlation to that in the other areas of Northern Xinjiang and Central Asia, but is not related to that in the other areas of Northwest China, Qinzhang Plateau and East China. This suggests that the difference of precipitation between monsoon and westerly belt is bigger than that of temperature. (3) In the past 314 years, the series of reconstructed precipitation had 4 w et periods above its mean and 4 dry periods bellow the mean. The wet periods were getting short and dry ones changed conversely. It is obvious that the climate changes toward warm and dry, which is related to the global change since beginning of this century. (4) The climatic patterns that cold match wet and warm match dry are predominant in the past 314 years, which is similar to the change of modern climate.

Key words: Yili region, Climatic characteristics, Dry-wet fluctuation