Based on the runoff, air temperature and precipitation data from 1961 to 2015 at the major stations on the upper Jinsha River, the annual and monthly variation characteristics and correlations among temperature, precipitation and runoff were analyzed. The results show a temperature rising trend which is gradually weakening from upstream to downstream. Most of the sudden changes in temperature occurred between 2002 and 2005, and the changes upstream are earlier than those downstream. The annual precipitation shows an increasing trend which is obvious in the upper and lower river sections, and not significant in the middle. The precipitation increase in the upper and middle sections from November to April is greater than that in summer and autumn months, and is significantly increased from March to May. In the lower river section, the precipitation shows a trend of slight increase from March to May, and in the other months there exist no obvious trends of decrease or increase. The sudden change points of precipitation occurred between 1997 and 1999. The trend of change in annual runoff is not obvious. The runoff increases significantly in the upper section from November to April, but not obviously in the remaining months. In the middle section, the increase from November to April is greater than that in summer and autumn, but the increase is not obvious. The runoff in the middle section shows trend of insignificant increase from February to May, and increases or decreases alternately in the other months. The sudden change points of runoff were between 2002~2003. On the upper Jinsha River, the closer the area to the source of the Yangtze River, the closer the relationship between precipitation and temperature. The increase of runoff is caused jointly by rising temperature and the precipitation, and is mainly affected by the change of precipitation in the lower section.
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