No upward trends in the occurrence of extreme floods in central Europe
No upward trends in the occurrence of extreme floods in central Europe
复制标题
DOI：
10.1038/nature01928
复制
发表时间：
2003-09-11
期刊：
影响因子：
64.8
通讯作者：
Grünewald, U
中科院分区：
文献类型：
--
作者：
Mudelsee, M;Börngen, M;Grünewald, U
在过去的几个世纪里，极端的河流洪水一直是欧洲的一个重大自然灾害（1），最近人为造成的大气成分变化的辐射效应预计会导致气候变化，特别是水文循环的增强（2），导致洪水风险增加（3，4）。然而，在过去的几十年里，来自欧洲的观测（1，5 -7）并未显示洪水发生率的明显增加。在这里，我们提出了长期记录的冬季和夏季洪水在两个最大的河流在中欧，易北河和奥得河。在过去的80至150年，我们发现在这两条河流的冬季洪水发生减少，而夏季洪水没有显示出任何趋势，极端降水发生的趋势一致。冬季洪水发生率的降低部分归因于强冰冻事件的减少，在这些事件之后，在冬季结束时打破河冰可能会起到水屏障的作用，并严重增加洪水。此外，我们发现显着的长期变化，洪水发生率在16至19世纪，并得出结论，减少河流长度，水库建设和森林砍伐对洪水频率的影响很小。
Extreme river floods have been a substantial natural hazard in Europe over the past centuries(1), and radiative effects of recent anthropogenic changes in atmospheric composition are expected to cause climate changes, especially enhancement of the hydrological cycle(2), leading to an increased flood risk(3,4). For the past few decades, however, observations from Europe(1,5-7) do not show a clear increase in flood occurrence rate. Here we present longer-term records of winter and summer floods in two of the largest rivers in central Europe, the Elbe and Oder rivers. For the past 80 to 150 yr, we find a decrease in winter flood occurrence in both rivers, while summer floods show no trend, consistent with trends in extreme precipitation occurrence. The reduction in winter flood occurrence can partly be attributed to fewer events of strong freezing-following such events, breaking river ice at the end of the winter may function as a water barrier and enhance floods severely. Additionally, we detect significant long-term changes in flood occurrence rates in the sixteenth to nineteenth centuries, and conclude that reductions in river length, construction of reservoirs and deforestation have had minor effects on flood frequency.