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Chapter 6 Using GIS for Spatial Analysis
2. Bring up the Select By Attributes dialog box. Choose lakes as the Layer
to select from. You’ll see that three fields are available to you – FID,
AREA, and NAME. Select ‘‘NAME’’ and press the Get Unique Values
button.
3. You’ll want to build a query that looks for the name of each of the five
Great Lakes as follows: (NAME = ‘Lake Erie’ OR NAME = ‘Lake Huron’
OR NAME = ‘Lake Michigan’ OR NAME = ‘Lake Ontario’ OR NAME =
‘Lake Superior’).
(Source: Esri® ArcGIS ArcMap ArcInfo graphical user interface
Copyright © Esri.)
4. Answer Question 6.8, and then click OK. All five Great Lakes will now be
selected. Close the Select By Attributes dialog box.
Question 6.8 Why is the “OR” operator used in this expression rather than
the “AND” operator? What would the same query give you back is you used
“AND” rather than “OR” in each instance?
5. Use the Select By Location tool to find out how many rivers are within
5 miles of the Great Lakes. Note that even if part of the river is within the
5-mile distance, the entire river system will be selected.