Abstract: In this paper, we used Morlet wavelet transform method to analyze the relationship between annual runoff in the mainstream of the Tarim River and sunspots activity dring 1957-2011. Results indicated that both annual runoff of the mainstream of Tarim River and number of sunspots were decreased dring 1957-2011. There were main periods of 4 a, 8 a, 18 a, and 21 a in annual runoff. On the scales of 8~9 a and 18~21 a, the annual runoff and number of sunspots had similar primary cycles. Sunspots activity had almost no effect on the characteristics of annual runoff change of the 4 a cycle, but the characteristics of the 18~21 a cycle were mainly influenced by sunspots activity. The annual runoff change of 8 a primary cycle was once closely related to sunspots activity, but the correlation was disrupted after 1980 due to strong interferences of human activities. This paper forecasts that 2012-2020 may be a withered water period for annual runoff in the mainstream of Tarim Riverin, and the average annual runoff may be about 35×10⁸~40×10⁸ m³．

Key words: annual runoff, mainstream of the Tarim River, sunspots number, wavelet analysis