標題: Conditional expectation for evaluation of risk groundwater flow and solute transport: one-dimensional analysis
作者: Liou, TS
Yeh, HD
環境工程研究所
Institute of Environmental Engineering
關鍵字: ground water;Monte Carlo analysis;risk assessment;sensitivity analysis;solute transport
公開日期: 10-十二月-1997
摘要: A one-dimensional groundwater transport equation with two uncertain parameters, groundwater velocity and longitudinal dispersivity, is investigated in this paper. The analytical uncertainty of the predicted contaminant concentration is derived by the first-order mean-centered uncertainty analysis. The risk of the contaminant transport is defined as the probability that the concentration exceeds a maximum acceptable upper limit. Five probability density functions including the normal, lognormal, gamma, Gumbel, and Weibull distributions are chosen as the models for predicting the concentration distribution. The risk for each distribution is derived analytically based on the conditional probability. The mean risk and confidence interval are then computed by Monte Carlo simulation where the groundwater velocity and longitudinal dispersivity are assumed to be lognormally and normally distributed, respectively. Results from the conditional expectation of an assumed damage function show that the unconditional expectation generally underestimates the damage for low risk events. It is found from the sensitivity analysis that the mean longitudinal dispersivity is the most sensitive parameter and the variance of longitudinal dispersivity is the least sensitive one among those distribution models except the gamma and Weibull distributions. (C) 1997 Elsevier Science B.V.
URI: http://dx.doi.org/10.1016/S0022-1694(97)00025-5
http://hdl.handle.net/11536/146
ISSN: 0022-1694
DOI: 10.1016/S0022-1694(97)00025-5
期刊: JOURNAL OF HYDROLOGY
Volume: 199
Issue: 3-4
起始頁: 378
結束頁: 402
顯示於類別:期刊論文


文件中的檔案:

  1. A1997YF31000010.pdf