1961—2013年内蒙古地区极端降水时空变化分析

Analysis on the Temporal and Spatial Change of Extreme Precipitation in Inner Mongolia from 1961 to 2013

选取内蒙古具有代表性的71个地面气象站1961—2013年逐日降水及平均降水量资料,计算各等级降水日数,分析不同时间尺度及等级极端降水时空变化分布特征。结果表明:近53a内蒙古地区降水日数和小雨日数均呈减少趋势,但暴雨、大雨和中雨出现的概率略增;日和小时短时降水强度增大。20世纪80年代和90年代是中雨、大雨和暴雨多发期,也是日和小时降水强度最大时期,进入21世纪后,强降水发生频次减少。

This article selected daily precipitation and annual average precipitation data of 71 representative meteorological stations from 1961 to 2013 in Inner Mongolia, the precipitation days of each level was calculated, and the temporal and spatial distribution characteristics of extreme precipitation in different time scale and degree was analyzed. The results showed that the precipitation days and light rain days both showed a decreasing trend during recent 53 years in Inner Mongolia, but the chance of rainstorm, heavy rain and moderate rain was slightly increased; the intensity of one day and one hour precipitation was increased. Rainstorm, heavy rain and moderate rain occurred frequently in 1980s and 1990s, when the intensity of one day and one hour precipitation was the largest. While the frequency of heavy precipitation significantly reduced in the 21st century.