基于贝叶斯推断的溃坝概率模型
Development of probabilistic dam breach model using Bayesian inference
摘要：
溃坝模型常用于预测潜在溃坝的出流过程线，是评估洪水风险的关键因素。本文介绍了一种新的溃坝模型框架，它将提高均质土坝过程线预测的可靠性。力求少数的参数，简化的物理模型描述的过程中失败的堤坝决口扩大，由渐进的表面侵蚀驱动。其中坝料的侵蚀速率由经验输沙公式模拟。将该模型嵌入到贝叶斯多层次框架中，可以对不同类别的不确定性进行定量分析。为此，在文献中的观测峰值流量和历史溃坝的最终决口宽度的数据被用来进行模型反演，通过应用马尔可夫链蒙特卡罗模拟。先验知识主要基于无信息的分布函数。由此产生的后验分布表明，不确定性的主要来源是相关参数子集，由剩余误差项和量化违约侵蚀率的认识项组成。洪峰流量和最终溃口宽度的预测区间与文献中已知值一致。为了最终预测出流过程线的实际应用，制定了一个替代的残差模型，假设完美的数据和完美的模型。全概率的水文预测方式有可能改善下游洪水的充分风险管理。
英文摘要：
Dam breach models are commonly used to predict outflow hydrographs of potentially failing dams and are key ingredients for evaluating flood risk. In this paper a new dam breach modeling framework is introduced that shall improve the reliability of hydrograph predictions of homogeneous earthen embankment dams. Striving for a small number of parameters, the simplified physics-based model describes the processes of failing embankment dams by breach enlargement, driven by progressive surface erosion. Therein the erosion rate of dam material is modeled by empirical sediment transport formulations. Embedding the model into a Bayesian multilevel framework allows for quantitative analysis of different categories of uncertainties. To this end, data available in literature of observed peak discharge and final breach width of historical dam failures was used to perform model inversion by applying Markov Chain Monte Carlo simulation. Prior knowledge is mainly based on non-informative distribution functions. The resulting posterior distribution shows that the main source of uncertainty is a correlated subset of parameters, consisting of the residual error term and the epistemic term quantifying the breach erosion rate. The prediction intervals of peak discharge and final breach width are congruent with values known from literature. To finally predict the outflow hydrograph for real case applications, an alternative residual model was formulated that assumes perfect data and a perfect model. The fully probabilistic fashion of hydrograph prediction has the potential to improve the adequate risk management of downstream flooding.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
