HW#12 - Pilot Point Calibration

Note: You may work in pairs on this assignment.

In this exercise we will start with the same project we used in the previous assignment:

However, this time we will use the pilot point approach to calibrate the model. The pilot points will be associated with the hydraulic conductivity parameter for layer 1. For the other two parameters, we will once again use a simple zonal approach. Before you begin, download the following zip archive:


You will need to unzip the files after you download them. Then do the following:

1) Create a new 2D scatter point set called ppts.

2) Go to the Preferences dialog and set the default scatter point value to 1.0.

3) Use the Create Point tool to create a set of pilot points. Follow the placement guidelines we discussed in class. 30-50 points should be plenty. NOTE: You are welcome to use the grid-based distribution technique if you like.

4) Go to the Map Module and enter key values for the following parameters:

Kh in layer 1
Kh in layer 2
Recharge (big polygon - don't worry about landfill)

Be sure to select the Map -> MODFLOW command.

5) Go to the Global Options dialog and change the run mode to Parameter Estimation.

6) Go to the Parameters dialog in the MODFLOW menu and set up your list of parameters. Mark the Solve toggle for each of the three parameters. For the parameter corresponding to Kh in layer 1, turn on the pilot point option and select the ppts scatter point set. Enter a starting value for the other two parameters. Turn on the log transform option.

7) Save and run the model. Read in the solution and view your results. Compare to your manual solution and your first PEST solution.


Submittal Instructions

Save the GMS project with the completed solution. Zip up all files associated with the project.

Upload your zip archive via Learning Suite.