Abstract: Abstract: Based on the every 3-hour precipitation data from ERA-Interim dataset of European Centre for Medium-Range Weather Forecast (ECMWF) during 1979-2017, the spatial and temporal variation characteristics of precipitation in Qilian Mountain and its surrounding areas in the past 39 years were analyzed. The results show that the average annual precipitation in the study area was 232.4 mm, the precipitation had an increasing trend with a climate trend rate of 24.7 mm·(10 a)-1, and precipitation increased obviously in the semi-humid area, with a climate trend rate of 45.9 mm·(10 a)-1. The precipitation had a mutation between 1996 and 1997, and then increased significantly after 2000. The precipitation in the study area was largest in summer, accounting for 54.08% of the annual precipitation, while it was smallest in winter, accounting for 3.88% of the annual precipitation. The maximum monthly precipitation was 45.1 mm in July, while the minimum was 2.7 mm in December. The diurnal variation of precipitation had two peaks, the maximum peak value occurred during 14:00-20:00, and the second peak vaule occurred during 05:00-08:00. Both of the annual precipitation and climate trend rate in the study area had a good correspondence with the altitude. The higher the altitude was, the greater the precipitation would be, and the maximum precipitation was in the high altitude area in the central part of Qilian Mountains. The distribution of annual precipitation was mostly from northwest to southeast, and precipitation in the central and eastern parts of the Qilian Mountains was relatively larger.

Key words: Key words: Qilian Mountain, precipitation, ERA-Interim reanalysis data

摘要： 摘要：利用欧洲中期数值预报中心ERA-Interim再分析数据集1979—2017年3 h降水资料，分析祁连山及其周边地区降水量时空分布特征。结果表明：研究区平均年降水量为232.4 mm，年降水量有增加趋势，气候倾向率为24.7 mm·（10 a）-1，其中半湿润区增加最为明显，气候倾向率达45.9 mm·（10 a）-1；研究区降水量于1996—1997年之间发生突变，年降水量在2000年后显著增多；季节降水量夏季最大，占年降水的54.08%，冬季最小，占年降水的3.88%；月降水量7月最大，为45.1 mm，12月最小，仅为2.7 mm；日降水量有2个峰值，最大峰值出现在14:00—20:00，次峰值出现在05:00—08:00。年降水量及其气候倾向率均与地形高度有较好的对应关系，海拔越高降水量越大，最大值出现在祁连山中部的高海拔地区；年降水量场多呈西北—东南向分布，中部和东部地区降水量较大。

关键词: 关键词：祁连山, 降水量, ERA-Interim