How extreme was the October 2015 flood in the Carolinas? An assessment of flood frequency analysis and distribution tails
How extreme was the October 2015 flood in the Carolinas? An assessment of flood frequency analysis and distribution tails
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2015 年 10 月卡罗莱纳州发生的洪水有多严重？
DOI：
10.1016/j.jhydrol.2018.05.035
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发表时间：
2018
影响因子：
6.4
通讯作者：
M. Meadows
中科院分区：
文献类型：
--
作者：
R. Phillips;S. Samadi;M. Meadows
本文以2015年10月发生在美国北卡罗来纳州（NC）和南卡罗来纳州（SC）的洪水为中心，分析了极端洪水的频率、分布尾和超阈值峰值（POT）。2015年10月的洪水最显著的特点是达到峰值的时间很短（Tp）和持续数小时的洪峰，对人类生命、财产和基础设施造成了严重和广泛的破坏。2015年的洪水是由一系列强降雨事件造成的，这些降雨事件源于4级飓风华金（Joaquin），持续4天。这里，概率分布和分布参数（即，通过比较年最大洪水（AMF）和POT经验分布的上半部分，研究了洪水的位置、规模和形状，其中具有轻到重的理论尾部：Fréchet、Pareto、Gumbel、Weibull、Beta和Exponential。具体而言，使用了四组美国地质调查局（USGS）的测量数据，这些数据来自于记录长度约为65-125年的中央大陆。分析表明，双尾分布与POT和AMF数据的一致性更好，而不是更常用的指数（轻）尾概率分布。此外，阈值选择和记录长度影响尾部的沉重程度和父分布的波动。形状参数和它的演变在记录期间起着关键的和知之甚少的作用，在确定的规模洪水响应强降雨。
This paper examines the frequency, distribution tails, and peak-over-threshold (POT) of extreme floods through analysis that centers on the October 2015 flooding in North Carolina (NC) and South Carolina (SC), United States (US). The most striking features of the October 2015 flooding were a short time to peak (Tp) and a multi-hour continuous flood peak which caused intensive and widespread damages to human lives, properties, and infrastructure. The 2015 flooding was produced by a sequence of intense rainfall events which originated from category 4 hurricane Joaquin over a period of four days. Here, the probability distribution and distribution parameters (i.e., location, scale, and shape) of floods were investigated by comparing the upper part of empirical distributions of the annual maximum flood (AMF) and POT with light- to heavy- theoretical tails: Fréchet, Pareto, Gumbel, Weibull, Beta, and Exponential. Specifically, four sets of U.S. Geological Survey (USGS) gauging data from the central Carolinas with record lengths from approximately 65–125 years were used. Analysis suggests that heavier-tailed distributions are in better agreement with the POT and somewhat AMF data than more often used exponential (light) tailed probability distributions. Further, the threshold selection and record length affect the heaviness of the tail and fluctuations of the parent distributions. The shape parameter and its evolution in the period of record play a critical and poorly understood role in determining the scaling of flood response to intense rainfall.