湖泊水体富营养化评价的随机模拟与三角模糊数耦合模型

根据湖泊水环境系统的不确定性,建立了基于随机模拟和三角模糊数的湖泊水体富营养化评价耦合模型,采用三角模糊数表征各营养因子监测值,运用随机模拟方法模拟三角模糊数,得到各变量的随机模拟序列,由综合营养状态指数法确定湖泊的营养等级概率水平。以宁夏沙湖为例,运用此耦合模型对水体的富营养化程度进行评价。结果表明:该方法将水体富营养评价中水环境状态的不确定性以确定性方法融入评价模型,直观表征了水体在各营养状态隶属度的复杂性,评价结果更加全面、合理。

COMPREHENSIVE ASSESSMENT OF EUTROPHICATION STATUS BASED ON STOCHASTIC SIMULATION AND TRIANGULAR FUZZY NUMBERS APPROACH FOR LAKES

In order to address the uncertainties in lake environment,a methodology for assessing eutrophication status was developed by coupling stochastic simulation and triangular fuzzy numbers approaches.In the present study,the concentrations of trophic variables were described as triangular fuzzy numbers.The probability values for different degrees of eutrophication were calculated using synthesized trophic state index approach through extensive simulation experiments.The eutrophication assessment model based on stochastic simulation and triangular fuzzy numbers approaches was illustrated by a case study of evaluating the eutrophication status of Shahu Lake.The results showed that this deterministic model could better describe the uncertainties in water quality monitoring and in water environmental status.It was also helpful to indicate the complexities of membership for different trophic status.More reliable and valuable information could be provided to the decision makers.All the findings indicated that this model could provide new insights into eutrophication assessment.