淮河流域洪涝时空分布规律

Spatial and Temporal Distribution of Flood Disaster in Huaihe Basin

基于淮河流域18个分区1953～2007年主汛期(6～8月)降水资料,采用Z指数法、数理统计方法和经验正交函数分解(EOF)研究了淮河流域洪涝的时间分布规律及空间分布特征。结果表明,淮河流域汛期各月发生洪涝几率的趋势变化不显著,但6、7月发生洪涝的几率比8月大;6月在1988后发生重涝、大涝频率较1988年前明显增加;6、8月发生洪涝事件主周期较长,分别为11、10年,7月较短为3年,7月需注意旱涝急转;淮河流域洪涝类型主要为流域一致型,即梅雨型洪涝,洪涝中心在润河集至蚌埠区间;淮河流域洪涝空间分布特征受地形、地貌的影响,西南山区汛期发生洪涝的可能性比西北平原大,西南部洪涝中心位于大别山的腹地横排头附近。

The analysis of spatial and temporal distribution of flood disaster in the Huaihe Basin is carried out based on the Z index and empirical orthogonal function decomposition （EOF）, which is supported by the precipitation data at the main flood season （June-August） and observed in 18 zonings of Huaihe Basin during 1953-2007. The result shows the flood risk trend of each month in the main flood season is not significant, the risk in June and July is higher than August; the probability of extreme flood disaster in June has increased significantly after 1988; the duration period of flood disaster in June and August is long while in July is short, which are 11 years, 10 years and 3 years respectively; therefore, sudden changing from drought to flood should be concerned in July; the flood disaster in Huaihe Basin is mainly caused by Meiyu and occurred basin-wide in range, whose center is between Runheji and Bengbu; the spatial distribution of flood disaster is influenced by topography; as a result, the flood risk of southwestern mountain area is higher than that of northwestern plaing the center of flood disaster in southwestern area is near Hengpaitou, which is the hinterland of Dabie mountain.