Flood statistics with seasonal differentiated mixed distributions

季节差异混合分布的洪水统计

基本信息

批准号：
260442043
负责人：
Professor Dr. Andreas H. Schumann
金额：
--
依托单位：
Lehrstuhl für Ingenieurhydrologie und Wasserwirtschaft
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2014
资助国家：
德国
起止时间：
2013-12-31 至 2018-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/260442043?language=en
关键词：
Flood statistics seasonal differentiated mixed

项目摘要

In the last decades the estimation of flood probabilities by extreme value statistics for annual maximum flows was largely standardized in Germany by rules such as the DWA M -552. However the basic conditions for the application of extreme value statistics to the annual maximum values which were already emphasized by Gumbel in 1941 (the sample is homogeneous, i.e. each value of the sample is subject to the same distribution, and the causes of the events are the same) are not satisfied. The causes of the observed flood events are complex and varied. E.g. floods, caused by rain and snowmelt are mixed within series of annual maximum flows. It can be shown that winter and summer floods have different frequencies, which can be described by different distribution functions. The seasonal differences in the flood genesis, which is reflected in the seasonal variability of the occurrence of flood events of different sizes, are an important feature of the flood regime of a catchment. An inclusion of this feature in flood statistical analyzes can reduce their uncertainty and improves the estimation of probabilities for extremely rare flood events. As part of the planned work the seasonality of floods in different German regions will be analyzed. The results will be taken into account in the probabilistic assessment of extremely large events by mixed distributions. It is assumed that distribution functions of flood events, which differ in their origins can be determined with the help of seasonal differentiated analyzes. The different seasons will be separated by hydrological indicators which are derived from analyses of observed flood events. The seasonal flood probabilities can be described by different statistical approaches and finally combined to distributions of annual maximum values . Several mathematical options for calculating seasonal differentiated flood statistics will be compared. By considering a larger number of catchments in Bavaria, Thuringia and Saxony the generality of the newly developed approaches for generation of mixed distributions will be demonstrated. A significant improvement of flood statistical analyzes is expected as a result of the planned research work. The results of this basic research will be widely applicable for practice.

在过去的几十年中，通过诸如DWA M -552之类的规则，在德国对年度最大流量的极端价值统计数据的估计概率在很大程度上标准化。但是，将极值统计量应用于年度最大值的基本条件，而Gumbel在1941年已经强调了（样品是均匀的，即样本的每个值都遵守相同的分布，并且事件的原因是相同的）。观察到的洪水事件的原因是复杂而多样的。例如。雨水和融雪引起的洪水混合在一系列年度最大流动中。可以表明，冬季和夏季洪水具有不同的频率，可以通过不同的分布功能来描述。洪水创世纪的季节性差异反映在不同尺寸的洪水事件发生的季节性变化中，是集水区洪水制度的重要特征。将此功能纳入洪水统计分析可以减少其不确定性，并提高极少数洪水事件的概率的估计。作为计划工作的一部分，将分析不同德国地区洪水的季节性。结果将在混合分布的概率评估中考虑到极大的事件的概率评估。假定洪水事件的分布功能在其起源上有所不同，可以在季节性差异化的帮助下确定。不同的季节将通过从观察到的洪水事件的分析中得出的水文指标分开。季节性洪水概率可以通过不同的统计方法来描述，最后合并到年度最大值的分布中。将比较几种计算季节分化洪水统计的数学选择。通过考虑巴伐利亚州的大量集水区，将展示新开发的混合分布生成方法的通用性。由于计划的研究工作，预计洪水统计分析将大大改善。这项基础研究的结果将广泛适用于实践。