Flow module soil model

The above two modules form the soil quality model. The flow module drives the solute module. It is important to note that the moisture module can be absent from the model and in this case a model user has to input to the solute module information that would have been either produced by a moisture module, or would have been obtained from observed data at a site. 

SCRAM (28) is a TDE dynamic, numerical finite difference soil model, with a TDE flow module and a TDE solute module. It can handle moisture behavior, surface runoff, organic pollutant advection, dispersion, adsorption, and is designed to handle (i.e., no computer code has been developed) volatilization and degradation. This model may not have received great attention by users because of the large number of input data required. 

At this point it is important to note that the flow model (a hydrologic cycle model) can be absent from the overall model. In this case the user has to input to the solute module [i.e., equation (1)] the temporal (t) and spatial (x,y,z) resolution of both the flow (i.e., soil moisture) velocity (v) and the soil moisture content (0) of the soil matrix. This approach is employed by Enfield et al. (12) and other researchers. If the flow (moisture) module is not absent from the model formulation (e.g., 14). then the users are concerned with input parameters, that may be frequently difficult to obtain. The approach to be undertaken depends on site specificity and available monitoring data. 

Saturated soil zone (or groundwater) modeling is formulated almost exclusively via a TDE system, consisting of two modules, the flow and the solute module. The two modules are written as (9) ... 

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