The performance of this equation was verified, Results of that validation showed that the finite water-content vadose zone flux calculation method performed comparably to the numerical solution of Richards'equation.
32.
One of the main complications which arises in studying the vadose zone, is the fact that the unsaturated hydraulic conductivity is a function of the water content of the material.
33.
This greatly reduces the rate of infiltration and subsequent recharge, but also isolates the aquifer from the vadose zone, subsequent surface-associated losses due to evaporation and evapotranspiration, and potential contamination.
34.
The codes generally use climate and soil data to arrive at a recharge estimate and use the Richards equation in some form to model groundwater flow in the vadose zone.
35.
The water content is very important in vadose zone hydrology, where the hydraulic conductivity is a strongly nonlinear function of water content; this complicates the solution of the unsaturated groundwater flow equation.
36.
The lower boundary of the vadose zone ( the top of the phreatic zone ) is at an elevation of about at low flow, which suggests a low overall hydraulic gradient of 0.007-0.008.
37.
Research conducted at the Angelo Coast Range Reserve in northern California is comparing the membership and functioning of microbial communities involved in cycling of carbon and other compounds in soils and the vadose zone.
38.
Water in the vadose zone has a pressure head less than atmospheric pressure, and is retained by a combination of adhesion ( " funiculary groundwater " ), and capillary action ( " capillary groundwater " ).
39.
This work led to the development of two-and three-dimensional root water uptake models, and was one of the first vadose zone modeling inverse modeling studies that used a three-dimensional description of the subsurface for parameter estimation using distributed computing.
40.
Fundamental and applied aspects of the field address vadose zone functions, septic drain field site assessment and function, land treatment of wastewater, stormwater, erosion control, soil contamination with metals and pesticides, remediation of contaminated soils, restoration of wetlands, soil degradation, and environmental nutrient management.
