Probabilistic sensitivity analysis for one-dimensional solute transport

Transport of solute through soils is an important topic of current interest in groundwater hydrology and environmental geotechnics. Laboratory column test is usually conducted to determine transport parameters that are key to analytical solution of the advection-dispersion equation. Significant unce rtainty often exists in the solute transport parameters, as they are obtain ed empirically through nonlinear curve-fitting of column lest data. In the present study, a series of probabilistic sensitivity analysis is carried ou t to investigate the effects of transport parameter uncertainties on the ef fluent concentration ina column test. The probabilistic sensitivity analyse s are performed using @Risk, a macro running on Excel, a popular spreadshee t program. @Risk allows the user to place a random variable in any spreadsh eet cell. The simulation analysis in @Risk is based on Monte Carlo or Latin Hypercube sampling technique. Various issues on the effect of transport pa rameter uncertainties are investigated. Based on the findings of the probab ilistic sensitivity analyses, an improved method for more accurate and cons istent determination of the transport parameters from the column test is de veloped. A column test is conducted and analyzed using the traditional meth od and the proposed method and a comparison of the two methods is made. The advantages of the proposed method are demonstrated.