淮河流域旱涝急转气候特征研究

Climate Characteristics of Drought-flood Abrupt Change Events in Huaihe River Basin

利用标准化旱涝指数和灾情资料挑选出了1960～2009年淮河流域各水资源二级分区的旱涝急转事件,在此基础上分析了旱涝急转事件的时空分布、水位特征和大气环流特征,结果表明,淮河流域在这50年中共有13年出现了旱涝急转,约4年一遇,其频次和降水强度的大值区都位于流域上游和南部;与长江中下游地区相比,淮河流域的旱涝急转事件更频繁、平均强度更大。旱涝急转具有先减少后增加的年代际演变特征,就年内分布来看,主要集中在6月下旬～7月上旬;干流各水文控制站的水位对旱涝急转的响应具有一定差异,其中王家坝站水位涨幅最大,对强降水的响应时间最短。从环流成因来看,三种典型的大气环流形势可以引发旱涝急转。

Using SPI drought-flood index and historical data of disasters, drought-flood abrupt change events from 1960 to 2009 were chosen. And their temporal and spatial distribution, water features and circulation were analyzed. The results show there is drought-flood abrupt change events happening in 13 years from 1960 to 2009, the frequency is about 4 years. High frequency and precipitation intensity areas are all located in upstream and north regions. Comparing with those in the Yangtze River Basin, the drought-flood abrupt change events are more frequent and stronger in the Huaihe River Basin. The events have the decadal characteristics of first decreasing and later increasing. And the events mainly distribute mainly from late June to early July during a year. The water levels at the various control stations have different response to the events. There is highest raising of water level at the Wangjiaba station with most rapid response to heavy rainfall. As for the cause of circulation, three kinds of typical atmospheric circulation situation can cause drought-flood abrupt change.