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.

在过去的几十年里，通过年度最大流量的极值统计来估计洪水概率在德国基本上已按照 DWA M -552 等规则进行了标准化。然而，Gumbel 在 1941 年就已经强调了极值统计应用于年度最大值的基本条件（样本是同质的，即样本的每个值服从相同的分布，并且事件的原因为一样）不满意。观察到的洪水事件的原因复杂多样。例如。由降雨和融雪引起的洪水混合在一系列年度最大流量中。可以看出，冬季和夏季洪水有不同的频率，可以用不同的分布函数来描述。洪水成因的季节差异，表现为不同规模洪水事件发生的季节变化，是流域洪水情态的重要特征。在洪水统计分析中包含此功能可以减少其不确定性，并改进对极其罕见的洪水事件概率的估计。作为计划工作的一部分，将对德国不同地区洪水的季节性进行分析。通过混合分布对特大事件进行概率评估时将考虑结果。假设可以借助季节差异分析来确定起源不同的洪水事件的分布函数。不同的季节将通过对观测到的洪水事件进行分析得出的水文指标来划分。季节性洪水概率可以通过不同的统计方法来描述，并最终组合成年最大值的分布。将比较计算季节性差异洪水统计数据的几种数学选项。通过考虑巴伐利亚州、图林根州和萨克森州的大量流域，将证明新开发的混合分布生成方法的通用性。计划中的研究工作预计将显着改善洪水统计分析。这项基础研究成果将广泛应用于实践。