Response of the snowmelt and glacier runoff to the climate warming-up in the last 40 years in Xinjiang Autonomous Region, China

Some analytical results of the measured runoff during 1950s to 1980s at out let hydrological stations of 33 main rivers and climatic data collected fro m 84 meteorological stations in Xinjiang Autonomous Region are presented. C omparison of hydrological and climatic parameters before and after 1980 sho ws that the spring runoff for most rivers after 1980s increased obviously a t a rate of about 10%, though the spring air;temperature did not rise very much. Especially, an increment by 20% for alpine runoff is observed during May when intensive snow melting occurred in the alpine region. To the contr ary, the runoff in June decreased about 5%. When the summer or annual runof f is taken into account, direct relationship can be found between the chang e in runoff and the ratio of glacier-coverage, except the runoff in August when the glacier melting is strong, indicating that climatic warming has an obvious effect on the contribution of glacier melting to the runoff increa se.