We develop a discontinuous ®nite element method for advection±di€usion equations arising in contaminant transport problems, based on the Local Discontinuous Galerkin (LDG) method of Cockburn B and Shu CW. (The local discontinuous Garlerkin method for time-dependent convection±di€usion systems. SIAM J Numer Anal 1998;35:2440±63). This method is de®ned locally over each element, thus allowing for...

In this paper, I explore the solution of the contaminant transport problem over a random conductivity field. First, I generate a random, correlated conductivity field by convolving independent, uniformly distributed random variables with the identity function. I use finite differences to discretize the diffusion equation to solve for the steady-state pressure gradient using Backward Euler. This...

We analyze a set of observations from a recently published, field-scale tracer test in a fractured till. These observations demonstrate a dominant, underlying non-Fickian behavior, which cannot be quantified using traditional modeling approaches. We use a continuous time random walk (CTRW) approach which thoroughly accounts for the measurements, and which is based on a physical picture of conta...

This paper presents the development of a real-time microsensor-based monitoring system that can be used to detect and characterize volatile organic compounds in soil and groundwater. The system employs an array of polymer-based microsensors (chemiresistors) packaged in a waterproof housing that is designed to protect the sensor from harsh subsurface environments, including completely water-satu...

In this study, SEDDEER (Sediment Deposition and Erosion), a stand-alone sediment and contaminant model which simulates one water box and the underlying multiple sediment bed layers, was incorporated into Water Quality Analysis Simulation Program (WASP7.4). WASP7.4 toxic module (TOXI7) was modified to include SEDDEER to develop WASP_SEDDEER model. Tests were designed to ensure that the coupling ...

Purely stochastic methods can yield useful prediction models of contaminant arrival-time distributions derived from advective-dispersive transport in a variety of one-dimensional environments. Two different models are considered, both relating to dispersion of a brief pulse of conservative contaminant in a steady flow system. The first model considers the arrival-time of a contaminant pulse in ...

Field studies at well-instrumented research sites have provided extensive data sets and important insights essential for development and testing of transport theories and mathematical models. This paper provides an overview of over 25 years of research and lessons learned at one of such field research sites on the Columbus Air Force Base in Mississippi, commonly known as the Macrodispersion Exp...

Key words: soil-water transport, van Genuchten model, petroleum hydrocarbons In modeling a phytoremediation strategy, the transport and fate processes of soil water are influenced by subsurface groundwater flow, precipitation events, microbial activity, and transpiring vegetation. This transport is modeled in a variably saturated environment in a vertical dimension and is represented by a Richa...

There has been a surge of work on models for coupling surface-water with groundwater flows which is at its core the Stokes-Darcy problem. The resulting (Stokes-Darcy) fluid velocity is important because the flow transports contaminants. The analysis of models including the transport of contaminants has, however, focused on a quasi-static Stokes-Darcy model. Herein we consider the fully evolutio...