中文摘要：

采用滑动平均、累积距平、线性倾向估计法分析陕西渭河流域1961年-2013年降水变化特征;采用滑动t检验、有序聚类、双累积曲线分析法分析径流突变性.结果显示：渭河流域降水量整体呈减少趋势,平均年降水日数为86 d;降水季节分配不均,集中在夏、秋两季;春、秋两季降水量呈现明显减小趋势;大雨日数与年平均降水量显著正相关,年平均降水量越大,年平均大雨日数出现频次的越高;流域西部和北部暴雨强度呈现增大趋势,东部和南部暴雨强度呈现微弱减小趋势.渭河华县站径流的突变点出现在20世纪70年代初和90年代初,降水量的变化与径流变化的趋势基本吻合.

英文摘要：

Using the moving average,cumulative departure,and linear tendency estimate methods,this paper investigated the precipitation characteristics of Weihe River basin during 1961-2013.The abrupt runoff changes were analyzed using the smoothing t test,orderly clustering,and double mass curve methods.The results showed that the precipitation in the Weihe River basin was generally decreasing,with 86 rainy days in an average year.The precipitation varied in different seasons,and was mainly concentrated in summer and autumn;it obviously decreased in spring and autumn.The number of heavy rainy days was significantly correlated with the annual average precipitation;the larger the annual average precipitation,the more frequent the heavy rainy days in an average year.Rainstorm intensity was increasing in the west and north of Weihe River basin,but was slightly decreasing in the east and south.The runoff in Huaxian had an abrupt change in the early 1970s and early 1990s.The precipitation variation was basically consistent with the runoff variation trend.