Download Groundwater Modeling System GMS v3.0 TUTORIALS

7-4
GMS Tutorials
image was imported to GMS, registered, and a GMS project file was saved.
To read in the image, we will open the project file. Once the image is
imported to GMS, it can be displayed in the background as a guide for on
screen digitizing and placement of model features.
7.4.1
Reading the Image
To import the image:
1. Select the Open command from the File menu.
2. Locate and open the directory entitled tutorial\modfmap.
3. Select the file entitled start.gpr.
4. Choose the Open button.
You should see a message indicating that the image is being resampled.
Eventually the image should appear. Now that the image is imported, it will
appear each time the screen is refreshed. All other objects are drawn on top of
the image. The image only appears in plan view.
You are actually viewing only a portion of the complete TIFF image. It is
possible to pan and zoom and resample the TIFF image to view a different
region or to view at a different resolution. More information on manipulating
TIFF images can be found in the GMS Reference Manual.
7.4.2
Image File vs. TIFF File
The project you just opened included a file called an "image" file. It is not the
file containing the TIFF image. The TIFF file is called "easttex.tif" and is
located in the same directory as the image file. When a TIFF file is first
imported it must be registered. Registering a TIFF file involves selecting three
points on the image and entering the real world coordinates of those points.
These points are used to stretch and position the image when it is drawn on the
screen so that it is drawn in the correct location. Once a TIFF image is
registered, the registration data and the name of the TIFF file are saved to an
image file. From that point on, the TIFF image can be imported and registered
in one easy step by opening the image file. The image we are using in this
tutorial was registered previously and the registration data were saved to a file
named "start.img" when the project was saved.
7.5
Feature Objects
We are now ready to begin constructing the conceptual model. Conceptual
models are constructed using feature objects in the Map module. Feature