Post on 11-May-2017
Groundwater ModelingComputer Implementation
Groundwater Vistas
• Groundwater Modeling Environment– Graphic User Interface (GUI) for MODFLOW and
other models
– Imports a wide variety of files• MODFLOW data sets
• ArcView shapefiles
• Digitized map files (AutoCAD DXF, Shapefiles, and SURFER)
• GroundwaterVistas is not MODFLOW (but includes it)
Installation
• Open the folder “Models” located in your CD
• Unzip gv6.zip to get
– gv6.exe (a “setup” file)
• Run gv6.exe to install
– Groundwater Vistas version 6, the last one
– Answer “yes” or “OK” to everything
• Groundwater Vistas manuals installed in
C:\gwv6\Documentation
www.groundwatermodels.com
Unit System
• Use a consistent set of units for all data
• Select a unit of length and time
– Hydraulic conductivity (K) in m/s or ft/s
– Pumping rates (Q) in m3/s ft3/s
– Length units in m or ft
– Elevations in m or ft
Coordinate Systems
• Model coordinates
– relative to lower left corner of grid
• Origin (0,0) lower left corner of grid
• Opposite to grid numbering
• Grid origin = row #1, column #1
• Map coordinates
– Define base map
– Used well locations, etc.
Example• Boundaries
– North & South: No-flow
– East & West: Constant-head
• Layer 1 – unconfined (13 m)– Kh = 5x10-3 m/s; Kv = 5x10-4 m/s
– Porosity = 0.25
• Layer 2 – confined (5 m)– Kh = 1x10-3 m/s; Kv = 1x10-4 m/s
– Porosity = 0.25
No-flow Boundary
No-flow Boundary
Con
sta
nt H
ea
d B
ou
ndary
(h =
9 m
)
Con
sta
nt H
ea
d B
ou
ndary
(h =
8 m
)
Pumping Well
60
0 m
600 mAdapted from Chiang, W-H and W. Kinzelbach, Processing Modflow: A
Simulation System For Modeling Groundwater Flow and Pollution, 1996
Pumping Well
Layer 1
Layer 2
51
3
10 m
-3 m
-8 m
N
Create a New Model
• Start the GV program
• Select File New
• Enter basic information– 30 rows & 30 columns
– Row spacing = 20 m
– Column spacing = 20 m
– Top of Layer 1 = 10 m
– Bottom of Layer 1 = -3 m
– Bottom of Layer 2 = -8 m
Model Grid
Elevation = +10 m
Elevation = -3 m
Elevation = -8
Add Constant Head Boundary Conditions• Select: Layer 1
• Select: BCs Constant Head Boundary
• Select: BCs Insert Window
• Hold left Mouse button and Drag cursor through cells in Column 1
• Set value to 9 mConstant Head
Boundary Cells
(h = 9 m)
Top Layer - 1
Press OK
Repeat for Boundary in Column 30• Select: Layer 1
• Select: BCs Constant Head Boundary
• Select: BCs Insert Window
• Hold left Mouse button and Drag cursor through cells in Column 30
• Set value to 8 m Constant Head
Boundary Cells
(h = 8 m)
Top Layer - 1
Repeat for Layer 2
• Select: Layer 2
• Select: BCs Constant Head Boundary
• Select: BCs Insert Window
• Hold left Mouse button and Drag cursor through cells in Columns 1 and 30
• Set values to 9 and 8 m
Constant Head
Boundary Cells
(h = 8 m)
Bottom Layer - 2
Add Hydraulic Conductivity
• Select: Props Hydraulic Conductivity
• Select: Property Values Database
• Set up 2 zones:
– Layer 1
• Kx= Ky = 5x10-3 m/s
• Kz = 5x10-4 m/s
– Layer 2
• Kx= Ky = 1x10-3 m/s
• Kz = 1x10-4 m/s
• Click OK
Assign K to Layer 1• Select: Layer 1
• Select: Props Hydraulic Conductivity
• Select: Props Set Value or Zone Window
• Start in upper right-hand corner and drag to select all cells in grid
• Select: OK
• Select: Zone Number 1
• Select: OK
Assign K to Layer 2• Select: Layer 2
• Select: Props Hydraulic Conductivity
• Select: Props Set Value or Zone Window
• Start in upper right-hand corner and drag to select all cells in grid
• Select: OK
• Select: Zone Number 2
• Select: OK
Add Multi-Layer Well
• Well penetrates full thickness of cells• Well penetrates more than one layer • Total pumping rate for multilayer well is sum of pumping
from layers• Pumping for each layer (Qk) is proportional to layer
transmissivity
• For a total pumping rate of Qtotal = 0.02 m3/s– Q1 = 0.0185 m3/s – Q2 = 0.0015 m3/s
2211KbKb
KbQQ kk
totalk
Add Well in Layer 1• Select: Layer 1
• Select: BCs Well
• Select: BCs Insert Single Cell
• Use cursor to click on cell at Row 15, Col. 25
• Enter “Flow Rate in Well” = - 0.0185 m3/s
• Select: OK
Row 15, Column 25
Note Top Layer - 1
Add Well in Layer 2• Select: Layer 2
• Select: BCs Well
• Select: BCs Insert Single Cell
• Use cursor to click on cell at Row 15, Col. 25
• Enter “Flow Rate in Well” = - 0.0015 m3/s
• Select: OK
Row 15, Column 25
Note Top Layer - 1
Create MODFLOW Dataset (1)
• Select: Model MODFLOW Packages
• Change: Root File = Ex1
• Select: OK
Create MODFLOW Dataset (2)• Select: Model MODFLOW Package Options
• Select: Time Units = seconds
• Select: Length Units = meters
• Select: OK
Create MODFLOW Dataset (3)• Select: Model MODFLOW Package Options
• Select: Tab Initial Heads
• Enter: 0 ft for both Layers
• Select: OK
Create MODFLOW Dataset (3)
• Select: Model MODFLOW Package Options
• Select: Tab BCF-LPF
• Select: Layer 1 as “Unconfined”
• Select: Layer 2 as “Confined”
• Select: OK
Create MODFLOW Dataset (4)
• Select: Model MODFLOW Package Options
• Select: Tab Recharge - ET
• Select: Top Layer Only
• Select: OK
Run Simulation
• Select: Calculator button
• Select: Yes
Process Results
• Select: Cell-by-cell flows
Results
• Select: Plot Contour Parameters (Plan)
• Set parameters to achieve the display you like
Set Display Options• Select: Plot What to display
• Select: Display Color Flood of Head
• Select: Display Legend
• Select: OK
Set Legend Options
• Select: Plot Legend Options
• Select: Contents
• Select: Color Flood Scale
• Select: Dry Cells
• Select: Title
• Select: Title Font = 10 bold
• Select: Text Font = 10
• Select: OK
Results
Results• Look for the file ‘Ex1.lst” in the directory that you specified for the “working
directory” (e.g., C:\gv5\models).
• Look for the following table and make sure you get the same (or close) numbers