Many studies of water flow and solute transport in the vadose zone require estimates of the unsaturated soil hydraulic properties, including the soil water retention curve ~WRC! describing the relationship between soil suction and water content. An artificial neural network ~ANN! approach was developed to describe the WRC using observed data from several soils. The ANN approach was found to pro...

We present a simple analytical solution for one-dimensional steady heat transfer with convection and conduction through a multilayer system such as a vadose zone. We assume that each layer is homogeneous and has a constant thermal diffusivity. The mass/heat flow direction is perpendicular to the layers, and the mass flow rate is a constant. The analytical solution presented in this study also a...

restrict communication to the atmosphere. As a result, gas pressures in the vadose zone will change more slowly Barometric pressure fluctuations may influence measured water and to a lesser extent than barometric pressure. Conlevels in wells where thick vadose zones or low permeability materials versely, gas pressure in an unsealed well will equilibrate overlie unconfined aquifers. Here, we pre...

in recent years, there has been increased concern over pollution of groundwater by NOj-, yet little is known about microbial N transformations below the crop rooting zone. This study investigated the importance of microbial denitrification below the crop rooting zone of conventional and no-till corn plots. The soil was a well-drained Matapeake silt loam located in the Atlantic Coastal Plain. Pl...

[1] The unsteady state drainage of water from a vertical sand column with and without a finer layer on the top was studied theoretically and experimentally to investigate the airflow generated by the finer layer. The sand column, saturated at its lower portion and initially in the condition of hydrostatic equilibrium, is drained at its bottom at constant head. The results show that significant ...

Water movement in soils is a key process that aff ects water quantity and quality in the environment. Movement of contaminants in soils is closely linked with the soil water fl ux and it is very important to properly evaluate these processes that occur in vadose zone. With development of new technologies more attention is dedicated to the use of numerical models to assess water fl ow behavior a...

The accidental overfilling of waste liquid from tank BX-102 at the Hanford Site in 1951 put about 10 t of U(VI) into the vadose zone. In order to understand the dominant geochemical reactions and transport processes that occurred during the initial infiltration and to help understand current spatial distribution, we simulated the waste liquid spilling event in laboratory sediment columns using ...