GEOG 4/575 Lab 8:
Dynamic Segmentation and Network Analysis
Due Dec 1 (Tuesday) before class.
The full score for this lab is 15.
The exercise comprises two parts related to two themes in linear feature analysis in GIS: dynamic segmentation and network analysis. The former focuses on applications that require location information on linear features. The latter emphasizes more on the connectivity of linear features than on the locations.
For the first part, finish all but
the 1st task in Chang’s Chapter 16. If you have not done geocoding (i.e., address matching) before, you should do
Task 1 on your own. For the second part, finish Tasks 3, 4, 5 and 6 in Chang’s
Chapter 17. Answer and submit all
questions listed at the end of this instruction. Lab exercise data are available in: I:\Students\Instructors\Geoffrey_Duh\GEOG4575\Chang_5e\chap16
and 17 (or on the textbook CD). Please copy all these folders to your
working directory in c:\Users before you start.
Part I (Chapter 16)
Additional notes:
Part I Questions:
1) What is the data source information in the properties dialog window of the “SpeedLimitsDecAll Events” layer that you created in Task 2? Is “SpeedLimitsDecAll Events” a polyline feature class? If it’s a feature class you should be able to find it in a geodatabase or as a shapefile.
2) In Task 3, how many rest areas are located in forested areas?
3) The identity tool in “Analysis Tools, Overlay” toolset can associate polygon attributes to linear features, a task very similar to the procedures you did in Task 4. The only difference is that identity tool won’t generate linear referencing measures. Describe one application that you need to use the procedures that you did in Task 4 instead of the identity tool.
4) The Route5_cities.dbf event table you created in Task 5 contains a new field call distance. What does a negative distance value, such as -1439, mean? Use ArcGIS online help to locate the help on “Locate Features Along Routes” and look up the definition of this distance field. You can use Distance field as the Offset field in the Add Route Events tool to verify the distance values.
Part II (Chapter 17)
Additional note:
Critical bug work-around:
In tasks 5 and 6, when trying to
right-click and bring out the context menus of the Network Analyst (on Step 3
in Task 5 and Step 2 in Task 6), ArcMap will stop
responding to user’s interaction. The
only way to work-around this problem is to not right-click the items in the
Network Analyst window. Here are additional instructions to complete
the tasks without using the context menu. This bug probably is fixed by one of
the patches (or service packs) of 9.3.1. My desktop computer doesn’t have this
problem. Make sure to download and update your ArcMap
with the latest patches.
Task 5. Step 3.
1)
Select Option from the
Network Analyst menu. Click on the Location Snap Option tab and select the Snap
to Position Along Network and unselect the Offset
check box. Click OK to continue.
2)
Use the Create Network
Location Tool on the Network Analyst toolbar with the firestat
layer as a reference to create two Facilities locations on the two firestat points. The show network analyst window will show
the two new Facilities as Graphic Pick (1) and Graphic Pick(2).
3)
Click on the Incidents
item in the Network Analyst window and then follow the instructions in Step 4
to complete the exercise.
Task 6. Step 2. – Use Steps 1 and 2
instructions above to replace Step 2 in the textbook. Then continue with
textbook’s Step 3 instructions.
Part II Questions:
1) What is the data source information in the properties dialog window of interstates_ND that you created in Task 3? If you rename interstates.shp to something else, will you still be able to see the interstates_ND network?
2) Insert maps (screenshots) of the shortest path you generated in Task 3 step 7, Task 5 step 4 and Task 6 step 4. Make sure you clearly label each map.