中文摘要：

利用黄河流域1960—2012年76个气象台站53a的逐日降水资料，应用趋势分析法、小波分析法、Mann—Kendall突变分析法、反距离加权法，研究极端降水时空变化。结果表明：①时间上，极端降水量、降水频数、降水强度倾向率分别为-0．64mm／10a、-0．0079d／10a和-0．078mm·d-2／10a，仅有极端降水比率表现为增长趋势，倾向率为0．49％／10a。极端降水量、降水频数、降水比率的突变时间不明显，而极端降水强度在1967年存在明显突变。极端降水指数均存在有28a和17a两个主振荡周期。上、中和下游极端降水量趋势变化发生转折的时间分别为1982年、2000年和1974年，UF与UB曲线均存在有多个交点，但都不是突变时间点；②空间上，黄河流域极端降水量由西北至东南呈阶梯式增多趋势，极端降水频数由流域北部向南部逐渐增大，极端降水强度和降水比率呈由西向东逐渐递增的规律。53a来，黄河流域极端降水量在流域西部、北部和西安周边地区呈不断增加趋势，极端降水频数在流域西部和北部地区具有增加态势，极端降水强度增加的区域主要分布在西宁和兰州周边以及银川一西安一带，极端降水比率整体呈增加趋势。

英文摘要：

Variation and trends in extreme climate events are receiving greater attention. Based on daily precipitation data recorded at 76 meteorological stations in the Yellow River Basin from 1960 to 2012, trends analysis, wavelet analysis, Mann-Kendall abrupt change analysis, and inverse distance weighting methods were employed to analyze the spatial distribution and temporal trends of extreme precipitation events. We found that in time, extreme precipitation, precipitation frequency and precipitation intensity displayed a decreasing trend at the rate of-0.64mm/ 10a, -0.007 9（t/10a and -0.078mm ~ dl/10a, respectively, while extreme precipitation ratio repre- sented an increasing trend at a rate of 0.49%/10a. An abrupt change was not obvious for extreme precipitation, extreme precipitation frequency and extreme precipitation ratio, but extreme precipitation intensity did abruptly＇ change in 1967. In addition, all extreme precipitation indices had two main oscillation cycles in common at 28a and 17a. A turning point of extreme precipitation occurred in 1982, 2000 and 1974 in the upper, middle and lower basins of the Yellow River, respectively. There were many intersection points of the UF and UB curve line, but they were not mutations. In space, extreme precipitation increased from northwest to southeast across the Basin. Extreme precipitation frequency tended to increase gradually from north to the south; extreme precipitation and precipitation ratio increased gradually from west to east. Extreme precipitation in the western and northern Basin and surrounding areas of Xi＇an showed an increasing trend; extreme precipitation frequency in western and northern regions of the Yellow River Basin also increased. An increasing trend of extreme precipitation intensity was mainly at Xining and Lanzhou, Yinchuan and surroundin~ areas of Xi＇an.