基于替代模型的地下水溶质运移不确定性分析

为分析参数的不确定性对地下水溶质运移数值模型的影响,采用蒙特卡罗(Monte Carlo)模拟对一算例进行分析,并从风险评估的角度对不确定性分析的结果进行了阐释.为减小计算负荷,利用Sobol'法对模型参数进行了灵敏度分析,筛选出较为敏感的参数作为随机变量,建立了模拟模型的克里格(Kriging)替代模型,进而实现Monte Carlo模拟.结果表明:置信度为80%时,井1,2,3浓度值的置信区间分别为23.46~42.06,47.99~66.73,69.54~82.94mg/L;结合风险评估,计算出地下水受污染的风险为0.54,可为地下水污染物防控与修复提供科学依据.

Uncertainty analysis of groundwater solute transport based on surrogate model

In order to analyze the influence that parameter uncertainty has on groundwater solute transport numerical simulation, this study adopted Monte Carlo simulation to conduct an uncertainty analysis on an example and illustrated its results from the perspective of risk assessment. For the purpose of reducing computation load, Sobol' method was used to analyze the sensitivity of model parameters, which helped to select the more sensitive parameters as random variables and to construct the Kriging surrogate model of the simulation model. This surrogate model provided further help in achieving the Monte Carlo simulation. Results showed:when the confidence was 80%, the confidence intervals of well 1, 2, 3 were 23.46~42.06, 47.99~66.73, 69.54~82.94mg/L, respectively. Combined with risk assessment, the risk of groundwater contamination was calculated as 0.54, which could serve as a scientific guide for the prevention and control of groundwater pollution.