研究报告

  • 张彦,窦明,李桂秋.基于Copula函数的水体富营养化联合风险概率研究[J].环境科学学报,2018,38(10):4204-4213

  • 基于Copula函数的水体富营养化联合风险概率研究
  • The analysis of joint risk probability of eutrophication based on copula function
  • 基金项目:国家自然科学基金(No.51679218,51879239);河南省高校科技创新人才支持计划项目(No.17HASTIT031);郑州大学优秀青年教师发展基金(No.1521323001)
  • 作者
  • 单位
  • 张彦
  • 1. 郑州大学水利与环境学院, 郑州 450001;2. 中国农业科学院农田灌溉研究所, 新乡 453002
  • 窦明
  • 郑州大学水利与环境学院, 郑州 450001
  • 李桂秋
  • 郑州大学水利与环境学院, 郑州 450001
  • 摘要:为了分析小型人工湖水体富营养化指标联合风险发生的概率,基于Copula函数的基本原理,结合眉湖水体富营养化模型模拟结果,建立了水体富营养化指标的边缘分布及Copula函数联合概率分布.通过Copula函数拟合检验和拟合优度评价筛选出不同组合方式下最优的Copula函数,并根据最优的Copula函数计算出水体富营养化指标的二维和三维联合风险概率.结果表明,不同组合方式下水体富营养化指标达到不同富营养化状态时的联合风险概率区别较大;当Chl-a和COD都为轻度富营养时,二维联合风险概率最大为62.29%,说明这种组合方式下眉湖水体极易发生轻度富营养;当Chl-a和COD都为轻度富营养、TN为中度富营养时,三维联合风险概率最大为45.46%,说明这种组合方式下眉湖水体极易发生中度富营养;由于受到水体富营养化指标监测系列的影响,部分二维和三维联合风险概率较小甚至为零.
  • Abstract:In order to analyze the joint risk probability of eutrophication indexes in a small artificial lake, a marginal distribution of eutrophication indexes and a joint probability distribution of the copula function are established based on the basic principle of the copula function combined with the simulation results of a eutrophication model in Meihu Lake. The optimal copula functions were selected under different combinations by the fit test of copula function and the goodness of fit evaluation. The two-dimensional and three-dimensional joint risk probability of eutrophication indexes were calculated using the optimal copula functions. Results show that the joint risk probability varies substantially when the eutrophication indexes reach different states of eutrophication under different combinations; the maximum two-dimensional joint risk probability is 62.29% when the chlorophyll a and chemical oxygen demand (COD) reached the light eutropher, which indicates that this combination is likely to cause light eutropher in the Meihu Lake; the maximum three-dimensional joint risk probability is 45.46% when the chlorophyll a and COD reached the light eutropher, and the total nitrogen reached the middle eutropher, which indicates that this combination is likely to cause middle eutropher in the Meihu Lake; some two-dimensional and three-dimensional joint risk probability are small or even zero due to the impact of the monitoring series of the eutrophication indexes.

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