CONTAMINANT TRANSPORT IN HETEROGENEOUS POROUS-MEDIA - A CASE-STUDY .2. STOCHASTIC MODELING

A stochastic modelling approach has been used to assess the uncertaint y in predictions of contaminant migration in geological media surround ing a hypothetical buried waste repository in Bedfordshire, UK. In Par t 1 of this two-part paper, the physical setting and the development o f the conceptual and numerical models for groundwater flow and transpo rt are described. In this part, the development of the stochastic mode lling approach and the analysis of the set of Monte Carlo experiments used to characterise the uncertainty in the migration pathways are pre sented. Eleven Monte Carlo experiments have been performed. Nine have been undertaken to evaluate the effect of uncertainty in the parameter s of the geostatistical model of hydraulic conductivity of the princip al aquifer, and two have been performed to examine the influence of th e location of the repository release zone. The study has demonstrated the use of the stochastic modelling approach in probabilistic risk ass essments bf the potential hazards arising from the burial of wastes.