Estimating the probability of widespread flood events
Estimating the probability of widespread flood events
复制标题
估计大范围洪水事件的概率
DOI：
10.1002/env.2190
复制
发表时间：
2013
期刊：
影响因子：
1.7
通讯作者：
R. Lamb
中科院分区：
文献类型：
--
作者：
C. Keef;J. Tawn;R. Lamb
洪灾是一种自然现象，经常在世界各地造成金融和人类破坏。在许多国家，洪灾风险由社会通过政府机构和保险业相结合的方式进行管理。对于这两种类型的组织来说，对可能发生的最大或最广泛的事件进行估计是有用的。这些估计可用来帮助准备或协调洪灾缓解活动，以及被保险和再保险行业用来评估金融风险。在本文中，我们发展了一种方法来模拟一组合成洪水事件，可以用来估计大范围洪水发生的可能性。我们使用一组英国河流流量计的数据来演示这种方法。此模拟过程中使用的模型基于Heffernan和Tawn的条件超越模型，该模型被扩展为包含极端河流洪水数据中的典型特征。文中还提出了一种改进的模型参数估计方法，并通过仿真研究验证了该方法的优越性。与以前使用的模型相比，该方法的好处是它为外推提供了理论基础，并且足够灵活地考虑到洪水数据中观察到的不同强度的极端相关性。版权所有©2012 John Wiley&Sons，Ltd.
Flooding is a natural phenomenon that regularly causes financial and human devastation around the world. In many countries the risk of flooding is managed by society through a combination of governmental agencies and the insurance industry. For both these types of organisation an estimate of the largest, or most widespread, events that can be expected to occur is useful. Such estimates can be used to help in preparing or co‐ordinating flood mitigation activities and by the insurance and re‐insurance industries to assess financial risk. In this paper we develop a method to simulate a set of synthetic flood events that can be used to estimate the probability of widespread floods. We demonstrate this method using data from a set of UK river flow gauges. The model used in this simulation process is based on the conditional exceedance model of Heffernan and Tawn, extended to incorporate features typically found in the data for extreme river floods. We also present an improved estimation method for the model parameters and demonstrate its advantages through the results of a simulation study. The benefits of the method over previous models used are that it provides a theoretical basis for extrapolation and is flexible enough to account for varying strengths of extremal dependence that are observed in flood data. Copyright © 2012 John Wiley & Sons, Ltd.