洞庭湖区旱涝灾害加剧的气象成因

The Weather Causes of the Aggravated Drought and Flood Disaster in Dongting Lake Region

利用洞庭湖区及湖南四水流域、长江上游地区气象观测资料和各类指标资料,基于统计方法,开展洞庭湖区旱涝加剧气象成因分析,得出如下结论:我国主雨带位置的年代际变化直接影响到洞庭湖区雨水资源的丰枯变化,进而影响到旱涝趋势的变化;东亚夏季风和赤道中东太平洋地区海表温度异常通过对我国主雨带位置的影响来影响洞庭湖区水资源的丰枯;气候变暖背景下洞庭湖各流域雨水资源向丰枯同步转变,易使洞庭湖洪水形成顶托之势或水资源来源枯竭,导致旱涝灾害加重;洞庭湖各流域枯水季节雨水资源减少加重洞庭湖区枯水季节缺水程度。

The result of analysis of the weather causes of the aggravated of drought and flood disaster in Dongting Lake Region based on statistic analysis of some indices and the meteorological observation data of Dongting Lake Region,the Four River basin in Hunan,the upper reaches of the Yangtze River show that the wet and dry of rainwater resources in Dongting Lake Region is directly influenced by interdecadal variations of the location of mainbelt in China. Further it influenced the tendency of waterlogging-drought variation. Then it influenced the tendency of waterlogging-drought variation. The East Asian summer monsoon and sea surface temperature in the central and eastern equatorial Pacific effected the location of main-belt in China then influence the wet and dry of rainwater resources in Dongting Lake Region. Rainwater resources in Dongting Lake basin synchronously wet or dry under the background of climate warming,which trend to result the flood pile up in Dongting Lake or lead to the origin of water resources exhausted. The increased of the water resources of Dongting Lake Basin at the dry season aggravated the water shortage level.