242 A dispersion are considered to be the dominant mechanisms of solute transport in the vadose zone, i.e., the variably saturated layer of soils and sediments between the soil surface and groundwater table (Jury and Flühler, 1992). Advection is associated with the average water fl ux or velocity, whereas hydrodynamic dispersion is modeled using an analog of Fick’s law corresponding to the Brow...

We describe our experiences running PFLOTRAN—a code for simulation of coupled hydro-thermal-chemical processes in variably saturated, non-isothermal, porous media—on the Cray XT series of computers, including initial experiences running on the petaflop incarnation of Jaguar, the Cray XT5 at the National Center for Computational Sciences at Oak Ridge National Laboratory. PFLOTRAN utilizes fully ...

Abstract Lagrangian methods, such as the random‐walk particle‐tracking (RWPT), are often qualified a potentially valuable alternative to error‐prone Eulerian methods for simulating solute transport in unsaturated porous media. Yet, RWPT method has not yet been validated against ‐ and compared currently used solutions under range of typical conditions. This paper presents new implementation appr...

Abstract Future increases in the frequency of tidal flooding due to sea level rise (SLR) are likely affect pore water salinities coastal aquifers. In this study, we investigate impact increased on salinity and flow dynamics aquifers using numerical variable‐density variably‐saturated groundwater salt transport models. Short (sub‐daily) long (decadal) period tides combined with SLR projections d...

Understanding how changes in volumetric water content (theta) affect bacterial adsorption could help reduce transport of pathogenic and indicator bacteria that may be present in infiltrating wastewater. Three flow regimes that simulated infiltration from a household septic system were evaluated: saturated, unsaturated with a constant volumetric water content theta (constant unsaturated flow), a...

Abstract. In water-stressed regions of the world, managed aquifer recharge (MAR), process intentionally recharging depleted aquifers, is an essential tool for combating groundwater depletion. Many groundwater-dependent regions, including Central Valley in California, USA, are underlain by thick unsaturated zones (ca. 10 to 40 m thick), nested within complex valley-fill deposits that can hinder ...

Extreme rainfall events are the major driver of shallow landslide occurrences in mountainous and steep terrain regions around the world. Subsurface hydrology has a dominant role on the initiation of rainfall-induced shallow landslides, since changes in the soil water content affect significantly the soil shear strength. Rainfall infiltration produces an increase of soil water potential, which i...