| A new approach to modeling reactive contaminant transport in groundwater is developed and evaluated. The approach is unique in that it uses a grid- or mesh-independent representation of model input parameters, including continuous velocities, dispersion coefficients, and saturated thickness values obtained directly from analytic element groundwater flow solutions.; The approach is realized within a suite of revised finite element, finite difference, and characteristic methods that are designed to improve the accuracy and reduce the computational costs of complex reactive vertically-averaged transport simulations in surficial aquifers. These methods are implemented in a fully object-oriented parallel-friendly software framework, benchmarked against existing analytic and numerical solutions, tested against traditional discrete methods, and applied to a set of difficult field-scale test problems.; It was found that the majority of the methods benefited from continuous representation, and that the use of the analytic element method can facilitate the development of computationally efficient multi-scale reactive transport models.; Importantly, this work represents the first thorough implementation of a linkage between reactive contaminant transport models and the analytic element method for modeling groundwater flow, and the first detailed analysis of such a linkage. |
