Visual HELP is the most advanced hydrological modeling environment available for designing landfills, predicting leachate mounding and evaluating potential leachate seepage to the groundwater table. Visual HELP combines the latest version of the HELP model (v.3.07) with an easy-to use interface and powerful graphical features for designing the model and evaluating the modeling results. This latest version of the HELP model addresses many of the limitations and bugs from earlier versions, and also includes several new analysis features.
Visual HELP uses the latest technologies in software engineering to introduce many new methods for visualizing and managing your projects, generating input data, presenting modeling results, and sharing data between models.?The result is a powerful and easy-to-use modeling tool that makes hydrologic landfill modeling more practical and accessible than ever before!
This completely-integrated modeling environment allows the user to:
Graphically create several profiles representing different parts of a landfill
Automatically generate statistically reliable weather data for virtually any location in the world (or create your own)
Run complex model simulations
Visualize full-color, high-resolution results
Prepare a summary document (tables and graphs) for your report
For professional applications in landfill design, Visual HELP is the only software package you will ever need!
Visual HELP applications
Landfill design and optimization:
Simulate multiple landfill profiles to find the most suitable design
Evaluate leachate mounding or leakage problems with current landfills
Determine the effectiveness of landfill caps for reducing leachate mounding
Design and optimize leachate collection systems
Groundwater recharge estimation:
Visual HELP has also proven to be an extremely valuable tool for accurately predicting seasonal groundwater recharge for periods of up to 100 years for use in MODFLOW models.? This seasonal recharge data has proven to significantly influence the vertical migration of contaminants through the unsaturated zone.
About the HELP model
The HELP model is a quasi-two-dimensional, deterministic, water-routing model for determining water balances.?The following is a description of the HELP model as derived from the HELP program reference manual:
The HELP program was developed by the U.S. Army Engineer Waterways Experiment Station (WES), Vicksburg, MS for the U.S. Environmental Protection Agency (EPA), Risk Reduction Engineering Laboratory, Cincinnati, OH, in response to needs in the Resource Conservation and Recovery Act (RCRA) and the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA, better known as Superfund) as identified by the EPA Office of Solid Waste, Washington, D.C.?The primary purpose of the model is to assist in the comparison of landfill design alternatives as judged by their water balances.
The Hydrologic Evaluation of Landfill Performance (HELP) model was developed to help hazardous waste landfill designers and regulators evaluate the hydrologic performance of proposed landfill designs.? The model accepts weather, soil and design data and uses solution techniques that account for the effects of surface storage, snowmelt, runoff, infiltration, evapotranspiration, vegetative growth, soil moisture storage, lateral subsurface drainage, leachate recirculation, unsaturated vertical drainage, and leakage through soil, geomembrane or composite liners.?Landfill system including various combinations of vegetation, cover soils, waste cells, lateral drain layers, low permeability barrier soils, and synthetic geomembrane liners may be modelled.? Results are expressed as daily, monthly, annual and long-term average water budgets.
The original version of the HELP model was first developed at WES in 1984 (Schroeder et al., 1984a and 1984b).?Since then there have been many advances in the technology and scope of the model and many of the defects in the code have been corrected.?The latest version of the HELP model is version 3.07 which contains many significant improvements and enhancements over the previous versions.?The following is a brief outline of the enhancements that have been made since Version 2 of the HELP model (Schroeder et al., 1988a and 1988b).
The number of layers that can be modeled has been increased
The default soil material texture list has been expanded to contain additional waste materials, geomembranes, geosynthetic drainage nets and compacted soils
The model now permits the use of customized soil textures
Computations of leachate recirculation and groundwater drainage into the landfill have been added
Leakage through the geomembranes due to manufacturing defects (pinholes) and installation mishaps (tears and punctures) is accounted for.
Estimation of surface runoff has been improved to account for large landfill surface slopes and slope lengths
The snow-melt model has been replaced with an energy-based model
The Priestly-Taylor potential evapotranspiration model has been replaced with a Penman method that incorporates wind and humidity effects as well as long-wave radiation heat losses
A frozen soil model has been added to improve infiltration and evapotranspiration predictions in cold regions
The unsaturated vertical drainage model has also been improved to aid in storage computations