Institute for Environmental Studies, VU University Amsterdam, The Netherlands.
Institute for Environmental Studies, VU University Amsterdam, The Netherlands; Deltares, Delft, The Netherlands.
Sci Total Environ. 2014 Mar 1;473-474:224-34. doi: 10.1016/j.scitotenv.2013.12.015. Epub 2013 Dec 25.
A central tool in risk management is the exceedance-probability loss (EPL) curve, which denotes the probabilities of damages being exceeded or equalled. These curves are used for a number of purposes, including the calculation of the expected annual damage (EAD), a common indicator for risk. The model calculations that are used to create such a curve contain uncertainties that accumulate in the end result. As a result, EPL curves and EAD calculations are also surrounded by uncertainties. Knowledge of the magnitude and source of these uncertainties helps to improve assessments and leads to better informed decisions. This study, therefore, performs uncertainty and sensitivity analyses for a dike-ring area in the Netherlands, on the south bank of the river Meuse. In this study, a Monte Carlo framework is used that combines hydraulic boundary conditions, a breach growth model, an inundation model, and a damage model. It encompasses the modelling of thirteen potential breach locations and uncertainties related to probability, duration of the flood wave, height of the flood wave, erodibility of the embankment, damage curves, and the value of assets at risk. The assessment includes uncertainty and sensitivity of risk estimates for each individual location, as well as the dike-ring area as a whole. The results show that for the dike ring in question, EAD estimates exhibit a 90% percentile range from about 8 times lower than the median, up to 4.5 times higher than the median. This level of uncertainty can mainly be attributed to uncertainty in depth-damage curves, uncertainty in the probability of a flood event and the duration of the flood wave. There are considerable differences between breach locations, both in the magnitude of the uncertainty, and in its source. This indicates that local characteristics have a considerable impact on uncertainty and sensitivity of flood damage and risk calculations.
风险管理的一个核心工具是超越概率损失（EPL）曲线，它表示损害超过或等于的概率。这些曲线用于多种目的，包括计算预期年损失（EAD），这是风险的常用指标。用于创建此类曲线的模型计算包含在最终结果中累积的不确定性。因此，EPL 曲线和 EAD 计算也存在不确定性。了解这些不确定性的大小和来源有助于改进评估并做出更明智的决策。因此，本研究对荷兰默兹河南岸的一个堤坝环区域进行了不确定性和敏感性分析。在本研究中，使用了一种蒙特卡罗框架，该框架结合了水力边界条件、溃口增长模型、淹没模型和损害模型。它涵盖了十三个潜在溃口位置的建模以及与概率、洪水波持续时间、洪水波高度、堤坝可侵蚀性、损害曲线和风险资产价值相关的不确定性。该评估包括对每个单独位置以及整个堤坝环区域的风险估计的不确定性和敏感性。结果表明，对于所讨论的堤坝环，EAD 估计值的第 90 个百分位数范围从比中位数低约 8 倍到高 4.5 倍不等。这种不确定性水平主要归因于深度损害曲线的不确定性、洪水事件的概率和洪水波持续时间的不确定性。溃口位置之间存在相当大的差异，无论是在不确定性的大小还是其来源方面。这表明，局部特征对洪水损害和风险计算的不确定性和敏感性有相当大的影响。
