Hydraulic modeling of water flow in the thick vadose zone under precipitation

An Integrated Approach for Modeling Water Flow and Solute Transport in the Vadose Zone

As geographical information systems (GIS) are increasingly being applied to surface and subsurface flow and transport modeling issues, it becomes important to more clearly define potential advantages and achievable objectives with this technology. This chapter describes an integrated conceptual framework for predicting basin-scale solute loading rates through and from the vadose zone. The appro...

An Improved Dual-Permeability Model of Water Flow and Solute Transport in the Vadose Zone

onstrated under field conditions (e.g., Flury, 1996; Jarvis, 2002). We introduce an improved, one-dimensional, non-steady-state dualIn recent years, our knowledge of the mechanisms that permeability model (MACRO 5.1). The model simulates water flow generate and sustain preferential movement of water and solute transport in the vadose zone of structured soils by coupling and solutes has been inc...

Vadose zone influences on aquifer parameter estimates of saturated-zone hydraulic theory

Aquifer drainage was numerically simulated by a coupled, unsaturated-saturated flow equation. The effect of the vadose zone on aquifer parameter predictions of classical hydraulic theory was investigated. Saturated-zone hydraulic theory was shown to be fairly robust in estimating the saturated hydraulic conductivity but less so in estimating drainable porosity, mainly because of the much tighte...

Biodegradation in the Vadose Zone

Preferential Flow and Transport of Cryptosporidium parvum Oocysts through the Vadose Zone: Experiments and Modeling

in the form of 4to 6m-long ovoid-shaped oocysts, with a double wall that is resistant to most oxidation As a result of Cryptosporidium parvum in drinking water, several processes such as ozonation and chlorination (Current, outbreaks of cryptosporidiosis have occurred in the last 10 yr. Al1986; Atwill et al., 1997). though it is generally believed that movement of pathogens through the soil is ...