Solute transport models in karst groundwater must consider variable and complex flow regimes. Within fissures less than 2 mm in aperture, during unsaturated flow events, seeping flow may flow as films or under capillary tension as a capillary rivulet. This project focuses on exploring the mass transport characteristics of seeping...
Vadose zone fractures and soil cracks exposed to the atmosphere have an impact on gas exchange processes at the Earth-atmosphere interface. In this study we explored and quantified the role of ground-surface winds on fracture ventilation. While the governing physical mechanisms that cause ventilation are relatively well understood, this is...
Evaporation of saline solutions from porous media, common in arid areas, involves complex interactions between mass transport, energy exchange and phase transitions. We quantified evaporation of saline solutions from heterogeneous sand columns under constant hydraulic boundary conditions to focus on effects of salt precipitation on evaporation dynamics. Mass loss measurements...
Colloids, particles smaller than ten microns in diameter, are ubiquitous in the subsurface. Colloids have an effect on the transport of contaminants that bind to their surfaces, and can reduce the permeability of aquifer materials through deposition. Some microorganisms, including pathogens, are also transported in the subsurface as colloids. The...
Surface tensions of high-salinity solutions are significantly different from those of pure water. Our objective was to develop and test a methodology to determine whether these surface tension effects predictably alter imbibition into dry and moist porous media. Static and dynamic experiments were performed using four grades of quartz sand...
Though many arid and contaminated sites have high salinity, prediction of effects of salinity on water movement in soils has been based on dilute solution approximations. Here a sensitivity analysis compares predicted liquid and vapor pressure in variably saturated porous media found using both the dilute approximations and a more...
Non-dilute salt strength solutions occur in many near surface geologic environments. In order to better understand the occurrence and movement of the water and salt, mathematical models for this non-ideal fluid need to be developed. Initial boundary value problems may then be solved to predict behavior for comparison with observations....
Evaporation from bare soil was investigated using a numeric model In one set of simulations, texture and evaporative demand were analyzed as they impacted short and long term evaporation. The effect of these factors on water redistribution was also analyzed. A second set of simulations was run to determine the...
Using thermodynamic principles, the general relationship describing the equilibrium vapor content in the gas phase above a saline liquid and across a curved liquid-gas interface is developed. Since high salt concentration also affects the intensive and extensive liquid properties, it is also necessary to account for these effects in liquid...
Water vapor transport in the vicinity of imbibing saline solutions was investigated in two-dimensional (2-D) chambers using a light transmission technique. Concentrated NaNO3 solutions (brines) were applied as point sources to the surface of homogenous packs of prewetted silica sand for four different sand grades. The same solutions were applied...