Groundwater
Modeling System (GMS)
Description:
GMS among the most sophisticated and comprehensive groundwater
modeling programs available. GMS provides tools for every
phase of a groundwater simulation including site characterization,
model development, calibration, post-processing, and visualization.
Rather than being limited to one main model, GMS supports
both finite-difference and finite-element models in 2D and
3D with eleven model options: MODFLOW 2000, MODPATH, MT3DMS/RT3D,
SEAM3D, ART3D, UTCHEM, FEMWATER, PEST, UCODE, MODAEM and SEEP2D.
Capabilities:
GMS has a variety of groundwater flow and transport modeling
capabilities. These include:
• 2-D Flow: Using the SEEP2D model you can
perform 2-D finite-element seepage modeling. This is an excellent
tool for modeling such things as dams, levees, and cutoff
trenches.
• 3-D Flow: MODFLOW 2000 allows the user to
perform 3-D finite difference modeling (in in the saturated
zone). FEMWATER allows for 3-D finite-element modeling in
both the saturated and unsaturated zones. These are excellent
tools for modeling the effects of pumping stations on groundwater
flows, desigining contaminated site remediation systems, or
modeling plume flow direction.
• Solute Transport: ART3D allows for simple
analytical transport modeling. MT3D, MODPATH, and FEMWATER
will each perform simple 3-D transport modeling. Reactive
3-D transport modeling can be done with RT3D AND SEAM3D, and
multi-phase reactive transport can be simulated using UTCHEM.
• Unsaturated Zone Flow and Transport: Both
FEMWATER and UTCHEM support fully 3-D flow and unsaturated
and saturated zone flow and transport modeling.
Limitations:
• GMS is a numerical model that simulates natural conditions,
but cannot dupilcate them. It is intended to show what would
likely happen if the modeled scenario were reproduced under
real-world conditions, but it cannot do so exactly. Keep this
in mind when preparing reports.
• Under some circumstances when tracing particles' paths
the number of particles can overwhelm the model. If the model
cannot simulate the paths of 20 particles, try a smaller number,
but one that is large enough to still yield useful results
• Placing pumping wells in ajacent cells or very near
one another can cause the model to slow down or crash
• While GMS is capable of very advanced calculations
and renderings, by keeping your simulations simple and not
overwhelming the model with data, you stand a better chance
of getting useful results.
Basic Inputs:
• Grid/ mesh cell sizes and soil characteristics (porosity,
hydraulic conductivity, hydraulic head, etc). You can view
your site from a variety of different angles or layouts (plan
view, 3-D oblique, etc)
• Locations of water bodies, roads, buildings, and topography
(if appropriate)
• Well locations and characterisics (injection or extraction,
pumping rates, etc)
• Contaminant species, species information (half life,
solubility, etc)
• Data or model parameters for interpolation, calibration,
or predictive analysis
Basic Output:
Depending on the inputs and model used, outputs may include:
• Site visualization: 3-D renderings of sites, including
stratigraphy, groundwater flow direction, contaminant plume
locations, aquifer locations, etc.
• Pumping well capture zones and particle flow paths
• Graphics for risk assessment with color-coded areas
of high/ low risk
• Site conditions' changes over given time intervals
• Solutions to parameter estimation problems
• Decay and transport results for groundwater contaminants
How to Run the Model:
The modeling capabilities of GMS can be easily explored by
following a few simple steps:
• Define a site and its characteristics (soil porosity,
conductivity, hydraulic head, etc). The site can be 2- or
3-D.
• Select the model you would like to run and input necessary
conditions. (number of particles to simulate, time period
over which to run the model, output resolution, etc)
• Run the model
• Save your results and run the model again under different
conditions to compare simulations.
Developer: Groundwater Modeling System (GMS) was developed by Environmental Modeling Systems, Inc. (ems-i), South Jordan, UT.
Faculty Contact: Gavin Gong
Application: Groundwater capture zone for remediation system design case study (E3250 - Hydrosystems Engineering)
