三江源区近50年降水量变化特征分析

利用三江源同德地区1961—2010年的逐月降水资料，采用线性回归、滑动平均、距平分析等方法，分析了该地区降水的变化特征。结果表明:三江源同德地区年降水量总体呈不显著减少趋势，具体表现为20世纪60—80年代和21世纪10年代降水量偏多，80年代明显偏高，2000年以后显著增多；从季节变化来看，秋、冬季降水量呈不显著增多趋势，春、夏季降水量呈不显著减少趋势。降水量年内分配十分不均，主要集中在5—9月。年降水量在1985年发生了由多到少的一个跃变；春季在1970年附近，夏季在1990年附近，秋季在1983年附近发生了由多到少转折；冬季降水量在1962年发生了由少到多的突变。

Analysis of Precipitation Variation Characteristics in Three-River Headwaters Region of China in Recent 50 Years

Based on the precipitation data form Tongde meteorological station in the Three-River headwaters region during the period from 1961 to 2010, and using the methods of climatic linear regression, 5-year moving average, anomaly analysis, we analyzed the change characteristics of precipitation. The results showed that the annual precipitation in this region presented an overall decreasing trend, which was higher during the period from 1960s to 1980s, and in the 2010s, and which was much higher in the 1980s, and significantly increased after 2000.The precipitation in autumn, and winter did not significantly increase, precipitation trend of spring and summer did not significantly reduce. Annual distribution of precipitation in Tongde area was very uneventful, the precipitation mainly occurred from May to September; annual precipitation had an obvious abrupt change point in 1985, from then on, the annual precipitation began to decline evidently. The abrupt change time occurred in spring is early 1970, and in summer in early 1990, and in autumn in early 1983; winter precipitation abrupt change occurred in 1962.