A Geostatistical Inverse Method for Variably Saturated Flow in the Vadose Zone

An iterative geostatistical inverse method for steady flow in the vadose zone

An iterative geostatistical inverse approach is developed to estimate conditional effective unsaturated hydraulic conductivity parameters, soil-water pressure head, and degree of saturation in heterogeneous vadose zones. This approach is similar to the classical cokriging technique, and it uses a linear estimator that depends on covariances and cross covariances of unsaturated hydraulic paramet...

Implementation of variably saturated flow into PHREEQC for the simulation of biogeochemical reactions in the vadose zone

A Finite-element Collocation Method for Variably Saturated Flow in Two Space Dimensions

1. INTRODUCTION This paper presents a finite-element collocation scheme for simulating variably saturated flows in two space dimensions. The scheme is an extension of a mass conserving one-dimensional formulation presented earlier [Allen and Murphy, 1985). The present exposition gives a complete description of work reported more briefly in the work by Murphy and Allen [1986]. Among the key feat...

A generalized Ross method for two- and three-dimensional variably saturated flow

Preconditioning Newton- Krylov Methods for Variably Saturated Flow

In this paper, we compare the effectiveness of three preconditioning strategies in simulations of variably saturated flow. Using Richards’ equation as our model, we solve the nonlinear system using a Newton-Krylov method. Since Krylov solvers can stagnate, resulting in slow convergence, we investigate different strategies of preconditioning the Jacobian system. Our work uses a multigrid method ...