We review the basic mathematical concepts of random walk particle tracking (RWPT) and its
advantages and limitations. Three different numerical approaches to overcome the local …

Since the first attempts some 20 yr ago in the field of hydrology, random walk (RW) particle
tracking as applied to solute transport has experienced profound changes. Concepts and …

A complete treatment of the theory and practice of groundwater engineering, The Handbook
of Groundwater Engineering, Second Edition provides a current and detailed review of how …

Interpretation of groundwater ages typically rests on assumptions of minimal mixing of
different water ages in the water samples. The effects of three‐dimensional, geologic …

Fractional derivatives can be viewed either as handy extensions of classical calculus or,
more deeply, as mathematical operators defined by natural phenomena. This follows the …

We extend the particle-tracking method to simulate general multi-rate mass transfer (MRMT)
equations. Previous methods for single-rate equations used two-state Markov chains and …

Gradients in contaminant concentrations and isotopic compositions commonly are used to
derive reaction parameters for natural attenuation in aquifers. Differences between field …

It is now widely recognized that contaminant release from low permeability zones can
sustain plumes long after primary sources are depleted, particularly for chlorinated solvents …

We use a particle-tracking method to simulate several one-dimensional bimolecular reactive
transport experiments. In our numerical scheme, the reactants are represented by particles …

The solution of space-fractional advection-dispersion equations (fADE) by random walks
depends on the analogy between the fADE and the forward equation for the associated …