1. Groundwater Modeling – 2: Computer Implementation
Groundwater Hydraulics
Daene C. McKinney

2. 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)
MODFLOW has no Graphic User Interface (GUI)

3. Groundwater Vistas Installation
Download file: gv5final.zip from
Unzip gv5final.zip to get
gv5final.exe (a “setup” file)
Run gv5final.exe to install
Groundwater Vistas version 5
Answer “yes” or “OK” to everything
Groundwater Vistas manuals installed in
C:\gwv5\manuals

4. Unit System Use a consistent set of units for all data
Select a unit of length and time
Hydraulic conductivity (K) in m/s
Pumping rates (Q) in m3/s
Length units in m
Elevations in m

5. Example Boundaries Layer 1 – unconfined (13 m)
Pumping Well
Layer 1
Layer 2 5 13
10 m
-3 m
-8 m
Boundaries
North & South: No-flow
East & West: Constant-head
Layer 1 – unconfined (13 m)
Kh = 5x10-3 m/s
Kv = 5x10-4 m/s
Layer 2 – confined (5 m)
Kh = 1x10-3 m/s; Kv = 1x10-4 m/s
No-flow Boundary
Constant Head Boundary (h = 9 m)
Constant Head Boundary (h = 8 m)
Pumping Well
600 m N
Adapted from Chiang, W-H and W. Kinzelbach, Processing Modflow: A Simulation System For Modeling Groundwater Flow and Pollution, 1996

6. Create a New Model
Start the GV program
Select File  New

7. Create a New Model 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
Press

8. Model Grid
Elevation = +10 m
Elevation = -3 m
Elevation = -8

9. 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 m
Press OK
Constant Head
Boundary Cells
(h = 9 m)
Top Layer - 1

10. 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

11. 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

12. Add Hydraulic Conductivity
Select: Props  Hydraulic Conductivity
Select: Property Values  Database
Set up 2 zones:
Layer 1
Kx = 5x10-3 m/s
Ky = 5x10-3 m/s
Kz = 5x10-4 m/s
Layer 2
Kx= 1x10-3 m/s
Ky = 1x10-3 m/s
Kz = 1x10-4 m/s
Click OK

13. 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

14. 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

15. Add Multi-Layer Well Well penetrates all layers
Pumping Well
Layer 1
Layer 2
Add Multi-Layer Well
Well penetrates all layers
Total pumping rate for multilayer well is sum of pumping from layers
Pumping for each layer (Qk) is proportional to layer transmissivity (bK)
For a total pumping rate of Qtotal = 0.02 m3/s
Q1 = m3/s
Q2 = m3/s

16. 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” = m3/s
Select: OK
Row 15, Column 25
Note
Top Layer - 1

17. 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” = m3/s
Select: OK
Row 15, Column 25
Note
Top Layer - 1

18. Create MODFLOW Dataset
Select: Model  MODFLOW  Package Options
Select: Time Units = seconds
Select: Length Units = meters

19. Create MODFLOW Dataset
Select: Model  MODFLOW  Package Options
Select: Tab  Initial Heads
Enter: 0 ft for both Layers

20. Create MODFLOW Dataset
Select: Model  MODFLOW  Package Options
Select: Tab  BCF-LPF
Select: Layer 1 as “Unconfined”
Select: Layer 2 as “Confined”

21. Create MODFLOW Dataset
Select: Model  MODFLOW  Package Options
Select: Tab  Recharge - ET
Select: Top Layer Only
Select: OK

22. Run Simulation
Select: Calculator button
Select: Yes, Yes, Yes!

23. Process Results
Select: Cell-by-cell flows

24. Results Select: Plot  Contour  Parameters (Plan)
Set parameters to achieve the display you like

25. Set Display Options Select: Plot  What to display
Select: Display Color Flood of Head
Select: Display Legend
Select: OK

26. 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

27. Results

28. 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