Parameter Estimation and Uncertainty Analysis for Rainfall Infiltration inUnsaturated Soils using a Bayesian Approach

摘要

In this study, a probabilistic method is proposed for estimating soil propertyand model uncertainty of a rainfall infiltration model in unsaturated soils using fieldobservation of pore-water pressures. The proposed method is formulated based on theBayesian framework and solved using the Markov Chain Monte Carlo simulationmethod. A case study of a field test of rainfall-induced slope failure is presented toillustrate the proposed method. It is found that all the parameters except q2 are wellidentified within a small region. The posterior distributions of k_s and α show a normalshape and two parameters are positively correlated. Before the rain period, the 95%total prediction uncertainty bounds indicate a relatively good model performance.During the rain period, the results are less accurate.