摘要
提出了量化影响河流水质的随机不确定性与灰色不确定性的水质超标灰色随机风险率概念 ,建立了水质超标灰色随机风险率评价模型。在水质单项参数评价模型中 ,将河流污染物浓度变量的分布处理成灰色概率分布 ,将污染物浓度超过水质类别标准值的风险率处理成灰色概率 ,即水质超标灰色随机风险率。在水质综合评价模型中 ,河流水环境系统被考虑为担任某一使用功能的可靠性系统 ,而任意一种水质参数超标意味着河流水体使用功能已不能得到应有的保证 ,也即表明水体综合评价超标 ,最后借鉴系统可靠性分析的理论和方法计算水质综合超标率。该方法应用于黄河花园口断面重金属污染风险评价。
The river water environment system is a system with many uncertainties. The risk assessment quantifying the influence of uncertainties on river water quality have been paid attention to widely. However, the most of research on risk assessment for river water quality confined to quantify stochastic uncertainty of the river water environmental system using the method of statistics. The research on quantifying the risk due to grey uncertainty of the river water environmental system is done less. Based on the theory of probability and grey system approach, the concepts of grey probability, grey probability distribution, grey probability density, grey expectation and grey variance are defined in this paper. The concept of grey stochastic risk for water quality concentrations exceeding the standard values is presented to quantify the influence of stochastic uncertainty and grey uncertainty on river water quality. The assessment models of grey stochastic risk for water quality concentrations exceeding the standard values are established. In the assessment model for the individual parameter, the contaminant concentration is modeled as a random variable with a grey probability distribution and the risk for contaminant concentration exceeding the standard value is expressed with grey probability-the grey stochastic risk for water quality concentrations exceeding the standard values. In the model of comprehensive assessment for multiple parameters, the river water environmental system is considered as the reliability system to undertake useful function, and the result that the concentration of anyone of water quality parameters exceeds the standard value shows that the useful function of river water environmental system cannot be guaranteed. Lastly, the comprehensive risks for water quality concentrations exceeding the standard values are computed by using the approach of reliability system. An example of application to evaluate the grey stochastic risks for heavy metals concentrations exceeding the standard values in the Yellow River at the Huayuankou section is given. The results provide more information and are satisfactory.
出处
《地理科学》
CSCD
北大核心
2002年第2期249-252,共4页
Scientia Geographica Sinica
关键词
水质
灰色不确定性
灰色概率
灰色概率分布
水质超标灰色-随机风险率
风险评价
Water quality
Grey uncertainty
Grey probability
Grey probability distribution
Grey stochastic risk for water quality concentrations exceeding the standard values
Risk assessment
