Hydrology and Climatology, Institute for Earth and Environmental Sciences, University of Potsdam, Germany.
Hydrology and Climatology, Institute for Earth and Environmental Sciences, University of Potsdam, Germany; Research Domain Transdisciplinary Concepts and Methods, Potsdam-Institute for Climate Impact Research, Potsdam, Germany.
Sci Total Environ. 2018 Jul 15;630:977-991. doi: 10.1016/j.scitotenv.2018.02.241. Epub 2018 Mar 7.
The flash-flood in Braunsbach in the north-eastern part of Baden-Wuerttemberg/Germany was a particularly strong and concise event which took place during the floods in southern Germany at the end of May/early June 2016. This article presents a detailed analysis of the hydro-meteorological forcing and the hydrological consequences of this event. A specific approach, the "forensic hydrological analysis" was followed in order to include and combine retrospectively a variety of data from different disciplines. Such an approach investigates the origins, mechanisms and course of such natural events if possible in a "near real time" mode, in order to follow the most recent traces of the event. The results show that it was a very rare rainfall event with extreme intensities which, in combination with catchment properties, led to extreme runoff plus severe geomorphological hazards, i.e. great debris flows, which together resulted in immense damage in this small rural town Braunsbach. It was definitely a record-breaking event and greatly exceeded existing design guidelines for extreme flood discharge for this region, i.e. by a factor of about 10. Being such a rare or even unique event, it is not reliably feasible to put it into a crisp probabilistic context. However, one can conclude that a return period clearly above 100years can be assigned for all event components: rainfall, peak discharge and sediment transport. Due to the complex and interacting processes, no single flood cause or reason for the very high damage can be identified, since only the interplay and the cascading characteristics of those led to such an event. The roles of different human activities on the origin and/or intensification of such an extreme event are finally discussed.
德国巴登-符腾堡州东北部的布劳恩斯巴赫的山洪暴发是 2016 年 5 月底至 6 月初德国南部洪水中发生的一次特别强烈和集中的事件。本文对此次事件的水文气象成因和水文后果进行了详细分析。采用了一种特定的方法，即“法医水文学分析”，以便回顾性地纳入和综合来自不同学科的多种数据。这种方法如果可能的话，以“近实时”模式调查此类自然事件的起源、机制和过程，以便跟踪事件的最新痕迹。结果表明，这是一次非常罕见的极端强度降雨事件，与流域特性相结合，导致了极端径流量加上严重的地貌危害，即大量的泥石流，这在这个小农村城镇布劳恩斯巴赫造成了巨大的破坏。这绝对是一个破纪录的事件，大大超过了该地区极端洪水排放的现有设计准则，即大约 10 倍。由于这种事件非常罕见，甚至是独一无二的，因此将其纳入明确的概率背景是不可靠的。然而，可以得出结论，所有事件组成部分的重现期（降雨、峰值流量和泥沙输移）都明显超过 100 年。由于复杂的相互作用过程，不能确定导致如此高破坏的单一洪水成因或原因，因为只有这些相互作用和级联特征导致了这样的事件。最后讨论了不同人类活动在这种极端事件的起源和/或加剧中的作用。
