Introducing Geographic Information Systems with ArcGIS: A Workbook Approach to Learning GIS, 3rd Edition

Some Geological Data

____ 8. Also in the Quadrangle_Data feature dataset you will find cole_rock_polygon, which shows the classification of the surface geology. Add it as a polygon layer, just as you previously added the soils feature class.

____ 9. Run through the same exercises with cole_rock_polygon as you did with cole_soil_polygon, looking at different levels of zoom:

• Summarize (on the NAME field) calling the resulting table Summary_NAME
• Identify some polygons
• Label polygons (use the NAME field)
• Display the polygons with different colors

Using the Identify tool, indicate what sort of rock the river bed is made of __________.

____ 10. In the Layer Properties window for cole_rock_polygon, click the Labels tab and change the size of the labels to 10 points. Experiment with different scales by typing into the text box on the Standard toolbar. (You only need to type the denominator of the scale fraction—the software will understand the scale you mean.) Notice that with scales smaller than about 1:30,000 (like 1:50,000), the labels are pretty much useless. And annoying! Select the Labels tab from Layer Properties, and then click the Scale Range button. Activate the radio button for “Don’t Show Labels When Zoomed. In the Out Beyond text box, type 30000. Click OK, Apply, and OK. Now notice that a zoom level of 1:30000, you see labels. At 1:30001, you don’t.

The concept of showing details of layers only between specified scale levels applies to feature as well as labels. Suppose ...