Probabilistic modelling of flood events using the entropy copula
Probabilistic modelling of flood events using the entropy copula
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DOI：
10.1016/j.advwatres.2016.09.016
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发表时间：
2016-11-01
影响因子：
4.7
通讯作者：
Zheng, Qian
中科院分区：
文献类型：
--
作者：
Li, Fan;Zheng, Qian
洪水频率的估算对于防洪策略和水工结构设计至关重要。根据观测的统计特性生成合成洪水事件是分析洪水频率的可行方法之一。由于洪水事件变量（即洪峰、洪水量和持续时间）之间存在统计依赖性，需要进行多维联合概率估计。近年来，Copula方法被广泛用于多变量相关结构的构建，然而，在应用之前需要选择Copula族，并且选择过程有时相当主观。本研究采用的新的copula家族——熵copula，结合copula和熵的理论，提出了一种避免相对主观过程的方法。分析表明了熵 copula 对两个水文仪表洪水事件概率建模的有效性，并与流行的 copula 进行了精度比较。采用吉布斯采样技术进行三变量洪水事件模拟，以减轻直接扩展到三维的计算困难。模拟结果表明，熵连接函数是一种简单有效的三变量洪水模拟连接函数族。 (C) 2016 Elsevier Ltd. 保留所有权利。
The estimation of flood frequency is vital for the flood control strategies and hydraulic structure design. Generating synthetic flood events according to statistical properties of observations is one of plausible methods to analyze the flood frequency. Due to the statistical dependence among the flood event variables (i.e. the flood peak, volume and duration), a multidimensional joint probability estimation is required. Recently, the copula method is widely used for multivariable dependent structure construction, however, the copula family should be chosen before application and the choice process is sometimes rather subjective. The entropy copula, a new copula family, employed in this research proposed a way to avoid the relatively subjective process by combining the theories of copula and entropy. The analysis shows the effectiveness of the entropy copula for probabilistic modelling the flood events of two hydrological gauges, and a comparison of accuracy with the popular copulas was made. The Gibbs sampling technique was applied for trivariate flood events simulation in order to mitigate the calculation difficulties of extending to three dimension directly. The simulation results indicate that the entropy copula is a simple and effective copula family for trivariate flood simulation. (C) 2016 Elsevier Ltd. All rights reserved.