海河流域暴雨的气候特征与环流分型

选用海河流域1961~2012年132站逐日降水资料,通过趋势分析、M-K检验、EOF和REOF等方法分析了50余年海河流域暴雨的气候统计特征。利用NCEP/NCAR再分析资料和历史天气图资料,研究了海河流域14个典型强致灾暴雨过程的大气环流特征。结果表明:(1)海河流域夏季暴雨日站数和暴雨量的时空分布相近,暴雨日站数下降趋势较为显著;(2)海河流域夏季暴雨的空间分布可划分为3个分布型态:西南型、东北型和东南型;(3)海河流域暴雨在20世纪70年代末至80年代初存在一次突变现象;(4)海河流域强致灾暴雨过程可归纳为5类主要环流型,即高空低槽型、高空冷涡型、副高外围切变线型、低空低涡型和台风北上型。

Climatic Characteristics of Rainstorms and Circulation Types in Haihe River Basin

Using the historical daily precipitation data from the 132 stations in the Haihe River Basin over the period of 1961-2012, the statistical characteristics of the rainstorms in the Haihe River Basin in 52 years were analyzed. The NCEP/NCAR reanalysis data and historical weather charts were also applied to investigate the circulation features of the 14 typical disaster-causing rainstorm events in the basin. Frequency of the summer rainstorms in the basin has the same spatial distribution with the precipitation, while the frequency shows more significant descending trend. Three types of spatial distribution of summer rainstorms in the basin were defined, namely south-west type, north-east type and south-east type. An abrupt change of the rainstorms in the basin happened during the period from late 1970s to early 1980s. Sever rainstorms in the basin are usually caused by 5 types of circulations, namely upper level trough, lower level trough, upper level cold vortex, shear line around the fringe of subtropical high and north moving typhoon.