黄河流域寒潮天气与凌情关系分析

Relation between Cold Wave Weather and Ice Regime in Yellow River Basin

利用1951～2008年冬季(11月至翌年3月)各月气温资料,统计分析了近50年黄河流域的寒潮天气过程,阐述了寒潮时空分布规律、变化特点、强度和影响范围。分析了寒潮天气与黄河凌情的关系及对凌情的影响,得出黄河流域寒潮天气在时间和空间上的分布是不均匀的,位于高纬度地区的宁蒙河段寒潮发生频率高于黄河下游,寒潮的强度也强于黄河下游,寒潮覆盖的范围也大于黄河下游;黄河流域以一般性寒潮天气最多,历史上强寒潮发生的次数非常少,除了磴口站发生过3次外,流域其他站均未发生过;20世纪80年代中期以后寒潮的活动呈现出逐步减少的趋势,冬季寒潮发生趋于平静;黄河流域50%的封河是寒潮天气造成的;冬季寒潮天气多封河天数也多;冬季寒潮过程次数多、降温幅度大、持续时间长、最低气温低时,黄河下游封河长度将较常年明显偏长。

Using the winter monthly air temperature data （November of this year to March of next year） from 1951 to 2008, this paper statistically analyzed the cold wave weather process in the Yellow River Basin during the last 50 years, and described the temporal and spatial distribution, variation characteristics, intensity and influence scope of the cold wave. This paper also analyzed the cold wave weather with the relation of the ice regime and its influence on the Yellow River. The results show that the spatial and temporal distribution of the cold wave for the Yellow River is uneven, and the cold wave occurrence frequency of the Ning- Meng reach is higher than that of the lower Yellow River, and also for cold wave intensity and influence area. In the Yellow River Basin, the ordinary cold wave weather process often occur while the strong intensity cold wave seldom occur. Since 1980, the number of cold wave activities has the tendency of decrease, the winter cold wave occurrences tend to quiet. Almost 50% of the freeze-up of the Yellow River caused by cold wave weather, the more cold wave processes and the longer freeze-up.