| 引用本文: | 江聪,刘章君,温天福.上游干支流洪水相关性对下游洪水频率分布的影响——以鄱阳湖抚河为例.湖泊科学,2024,36(4):1232-1240. DOI:10.18307/2024.0453 |
| Jiang Cong,Liu Zhangjun,Wen Tianfu.Impact of the correlation between the flood of upstream tributaries on the frequency distribution of downstream flood—A case study in Fuhe River of Lake Poyang. J. Lake Sci.2024,36(4):1232-1240. DOI:10.18307/2024.0453 |
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| 摘要: |
| 较大流域下游的洪水往往是由上游干支流洪水叠加形成,而上游洪水变量一般会存在一定的空间相关性。为揭示流域不同来源洪水相关性对下游洪水频率分布特征的影响,本文选取江西省抚河流域作为研究实例,通过广义回归模型构建下游洪水变量对上游干支流洪水变量的条件分布,以此刻画上下游洪水变量之间的关系,然后基于二维Copula函数建立上游干支流洪水变量的联合概率分布,最后由全概率公式推导出下游洪水频率分布,在此基础上,进一步探讨上游洪水变量相关性对下游洪水频率分布特征的影响。结果表明,本文提出的洪水频率分布推导法对抚河李家渡站的洪水频率分布具有较好的拟合效果;上游洪水变量相关性是影响下游洪水频率分布的重要因素,具体来说,相关性的强度与尾部相关性对下游洪水频率分布的均值没有影响,但均对偏态系数Cv与峰度系数Cs等高阶统计特征有较为明显的影响,下游洪水频率分布的Cv值会随上游洪水变量相关性的增强呈现增加趋势,上尾相关性越强,Cv和Cs越大;流域上游洪水变量相关性强度及上尾相关性的增强都会导致下游极端洪水风险升高,此外,重现期较长的极端水文设计值对上游洪水变量相关性的变化更加敏感。 |
| 关键词: 洪水频率分布 洪水变量相关性 全概率公式 Copula函数 抚河 |
| DOI：10.18307/2024.0453 |
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| 基金项目:国家自然科学基金项目(52269003)、江西省鄱阳湖水资源与环境重点实验室开放研究基金项目(2020GPSYS06)和江西省主要学科学术和技术带头人培养计划青年人才项目(20212BCJ23016)联合资助。 |
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| Impact of the correlation between the flood of upstream tributaries on the frequency distribution of downstream flood—A case study in Fuhe River of Lake Poyang |
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Jiang Cong1,2, Liu Zhangjun1,3, Wen Tianfu1,3
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1.Jiangxi Provincial Key Laboratory of Water Resources and Environment of Poyang Lake, Nanchang 330029, P. R. China;2.School of Environmental Studies, China University of Geosciences, Wuhan 430074, P. R. China;3.Jiangxi Provincial Institute of Water Sciences, Nanchang 330029, P. R. China
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| Abstract: |
| Downstream flood in a large basin is generally caused by the superposition of upstream floods from different tributaries. There is certain correlation between the flood from upstream tributaries. To investigate the impact of the correlation between upstream flood on the frequency distribution characteristics of downstream flood, the frequency distribution of downstream flood was derived using the law of total probability based on the construction of conditional distributions of floods for both upstream and downstream conditions, as well as the joint probability distribution of flood variables in upstream tributaries. This study took the Fuhe River Basin in Jiangxi Province as the study area, and derived the flood frequency distribution at the Lijiadu hydrological station downstream from the Fuhe River using the joint probability distribution of flood variables from the Liaojiawan and Loujiacun stations in the upstream tributaries. The influence of the correlation of upstream flood variables on the downstream flood distribution was investigated. The results showed that the proposed method has a good fit for the flood frequency distribution at the Lijiadu Station. The correlation of the upstream flood variables was found to be an important factor determining the downstream flood frequency distribution. Specifically, the strength of correlation and tail correlation had no impact on the mean of flood frequency distribution, but had significant impact on higher-order statistical features such as skewness coefficient (Cv) and kurtosis coefficient (Cs). The Cv value of the downstream flood frequency distribution increased with the enhancement of the spatial correlation of upstream flood variables. A stronger upper-tail correlation resulted in larger values of both Cv and Cs. The increase in the strength of the correlation or upper-tail correlation of upstream flood variables led to a high flood risk of the basin. Extreme hydrological designs were more sensitive to changes in the correlation of upstream flood variables. |
| Key words: Flood frequency distribution dependence of flood variables total probability formula copula Fuhe River |
