WHI UnSat Suite DESCRIPTION

WHI UnSat Suite for Windows 95/98/NT

1-D Unsaturated Zone Groundwater Flow and Transport Modeling Using VLEACH, PESTAN,
VS2DT and HELP

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Introduction to the WHI UnSat Suite

The WHI UnSat Suite combines VLEACH, PESTAN, VS2DT and HELP in a revolutionary graphical environment specifically designed for simulating one-dimensional groundwater flow and contaminant transport through the unsaturated zone. All four of these models are compiled and optimized to run as native Windows applications and are seamlessly integrated within the WHI UnSat Suite modeling environment.

Professional Applications of the WHI UnSat Suite

  • Predict vertical migration of volatile hydrocarbons through the vadose zone using VLEACH
  • Estimate agricultural pesticide migration through the unsaturated zone using PESTAN.
  • Simulate groundwater flow and transport processes through heterogeneous, unsaturated soil using VS2DT.
  • Evaluate and optimize the hydrologic design of a landfill using the HELP model.

About the Interface

The WHI UnSat Suite utilizes a unique interface design that accommodates the specialized features and analysis capabilities of each model while maintaining a consistent look and feel for each data set. The familiar design and functionality of the interface makes it extremely easy to learn and facilitates rapid development of multiple model profiles. The interactive graphical tools allow you to quickly and easily create a model profile, modify the layer design, and customize the model properties and boundary conditions. In addition, the WHI UnSat Suite supports a teamwork environment where project files can be run over a networked system.

About the Models

VLEACH (Vadose zone LEACHing model)

VLEACH is a one-dimensional finite difference model for simulating the vertical mobilization and migration of dissolved organic contaminants through the vadose zone. This model is commonly used to evaluate potential groundwater impacts and predict volatilization or VOCs.

Model Details

  • One layer profile
  • Homogeneous soil properties
  • Depth-dependent initial soil concentrations
  • Constant recharge rate
  • Includes a database of soil and chemical properties

Simulated Processes

  • Steady-state flow and transport of volatile organic contaminants through the unsaturated zone
  • Leaching of soil contaminants to infiltrating groundwater, sorption of dissolved contaminants on soil, volatilization and diffusion of contaminants to the atmosphere

Simulation Results

  • Graphical and tabular reports of soil concentration vs. time for selected profile depths
  • Graphical and tabular reports of groundwater concentration vs. time for selected profile depths
  • Graphical and tabular reports of vapor phase concentration vs. time for selected profile depths
  • Profile mass balances for soil, groundwater and vapor phase

PESTAN (PESTticide ANalytical model)

PESTAN is a one-dimensional analytical model for predicting the transport and degradation of dissolved pesticides through the unsaturated zone. PESTAN is commonly used for initial screening assessments to evaluate the potential for groundwater contamination by pesticides used in agriculture.

Model Details

  • One layer profile
  • Homogeneous soil properties
  • Multiple initial pesticide applications
  • Constant recharge rate
  • Includes a database of soil and chemical properties

Simulated Processes

  • Steady-state flow and transport of pesticides through the unsaturated zone
  • Leaching of pesticides to infiltrating groundwater, sorption of dissolved pesticides on soil, and first-order decay of pesticides

Simulation Results

  • Graphical and tabular reports of soil concentration vs. time for selected profile depths
  • Graphical and tabular reports of groundwater concentration vs. time for selected profile depths
  • Graphical and tabular reports of vapor phase concentration vs. time for selected profile depths
  • Profile mass balances for soil, groundwater and vapor phase
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VS2DT (Variably-Saturated 2-D flow and solute Transport model)

VS2DT is a finite difference numerical model for simulating steady-state or transient unsaturated flow and transport. Typical applications of the VS2DT model include determining the fate of agricultural chemicals, landfill leachate, UST leaks, and accidental chemical spills as they migrate through the unsaturated zone towards the water table.

Model Details

  • Multi-layer profile
  • Heterogeneous soil properties
  • Depth variable initial conditions for flow and chemistry
  • Transient boundary conditions for flow (specified head, pressure and flux)
  • Transient boundary conditions for contaminant transport (specified concentration or mass flux)
  • Includes a database of soil and chemical properties

Simulated Processes

  • Transient groundwater flow and contaminant transport through the unsaturated zone
  • Leaching of contaminants to infiltrating groundwater, sorption of dissolved contaminants on soil, and first-order decay of contaminants

Simulation Results

VS2DT produces detailed graphical and tabular summaries of both time-series and depth series information including:

  • Groundwater concentrations
  • Total head and pressure head
  • Flow velocity and flow rate
  • Contaminant flux rate
  • Soil moisture content and saturation
  • Accumulated flow balance and mass flux balance
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HELP (Hydrologic Evaluation of Landfill Performance)

The HELP model is a finite difference model used to evaluated the hydrologic performance of landfills containing multiple layers and different layer combinations.  The model is used to predict the seasonal generation, percolation and drainage of landfill leachate due to precipitation and infiltration.

Model Details

  • Multi-layer profile
  • Heterogeneous soil properties
  • Transient boundary conditions for flow (specified head, pressure and flux)
  • International weather generator
  • Includes a database of soil properties

Simulated Processes

  • Transient groundwater flow

Simulation Results

The hydrological results generated by the HELP model include time series information such as:

  • Precipitation, evapotranspiration and runoff
  • Lateral drainage from specific layer types
  • Percolation/leakage through specific layer types, and
  • Average head values specific layers

Click here for a more detailed description of Visual HELP.

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Model Output Features

The WHI UnSat Suite comes with a complete selection of graphical reporting tools for analyzing, interpreting and printing the simulation results. A specialized plotting component has been specifically developed for graphically representing the time-series and/or depth-series information obtained from each of the models.  Tabulated summaries of selected modeling results can also be produced.

An automated report generator creates a detailed document file describing the model profile properties and the simulation results together with supporting graphs.  The report document is created in rich text format using a powerful word processing component and is fully-customizeable.

Documentation

The WHI UnSat Suite contains detailed on-line help and is accompanied by a comprehensive user's manual containing easy-to-follow instructions and a step-by-step tutorial. Free technical support is provided by phone, fax and e-mail.

Hardware Requirements

  • PC Pentium
  • 32 MB RAM
  • 25 MB free disk space
  • VGA display and mouse
  • Windows 95/98 or Windows NT