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

Sliding through Time—Seeing Changes in Features at Intervals

____ 23. Bring up a new map in ArcMap. Add as data Lex_Roads_2002 from

IGIS-Arc_YourInitials\Historical_Data\Roads.mdb\Lexington_SP_North_83_Feet

____ 24. Right-click the Lex_Roads_2002 name in the T/C and open its attribute table. Find the field Repaved_Year. Run Statistics on that column.14 What is the earliest year? ________. The latest year? _________.

____ 25. Using Select By Attributes, display the roads that were repaved in 1995. How many were there? __________. How about 1999? ________. 2000? _________. Clear selections. Close the table.

____ 26. Open the layer Properties window of Lex_Roads_2002. Click the Time tab. Enable time features in the layer. Pick the Time Field: Repaved_Year. Apply. OK.

____ 27. Click the Time Slider button on the Tools toolbar. Click the far left icon until it doesn’t say Time is disabled on this map. Click the Options button on the Time Slider window and set the Time step interval to 1 year. Click the Playback tab. Press the radio button that lets you specify a duration in seconds. Put in 30. OK.

____ 28. Press the Play button and watch the map for half a minute. You will see the repaving history of the roads. When the process finishes you can manipulate the slider bar to see any particular year. Close ArcMap.

This data set is particularly course grained (yearly jumps), but you can see the potential here for time stamped data (like hourly runs of emergency vehicles). Or you ...