How can I split Census blocks?

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We do not recommend altering the block geography provided by the Census Bureau.

However, you can follow these steps if you must do so.

  1. Open a map* that includes Caliper’s Census block layer (ccBlock.cdf).
    You can open the Census block layer on its own, but we recommend having other reference layers available to help you make more accurate splits.
  2. Make the census block layer the working layer by right clicking on it in the Display Manager and selecting Make Working Layer.
  3. Export the layer as a standard geographic file via File>Export>Geography. This will allow you to make changes to the Census Block layer.
  4. Select Standard Geographic File in the To drop down.
  5. Rename the layer as Census Block Temp and check the Add Layer to Map checkbox.
  6. Save the layer as Temp Blocks.dbd.
  7. Refer to Chapter 8 of the Maptitude for Redistricting User’s Guide (Help>Maptitude for Redistricting User’s Guide) on how to edit the new Census Block Temp layer.
  8. When you are done making changes, right click on the Census Block Temp layer and selecting Make Working Layer
  9. Then select File>Export>Geography.
  10. Select Compact Geographic File in the To drop down.
  11. Rename the layer as Census Block Edited but do NOT check the Add Layer to Map checkbox.
  12. Save the layer as Blocks Edited.cdf.
  13. Close everything via File>Close All and do not save any changes to the map.
  14. Open a map that you would like to use as a base map for your plan by going to File>Open and changing the file type to Map, Workspace.
  15. Remove the old Census Block layer by right clicking on it in the Display Manager and selecting Remove.
  16. Add the new Census Block Edited layer created in step 11 by going to Map>Layers>Add Layer.
  17. Save the current map via File>Save As and save it as Basemap.map.

When creating new plans, you can use the newly created Basemap.map with the edited Census block layer.

**Do not follow these steps on an open plan. Hierarchical features (blocks, block groups, voting districts, tracts, counties) used in a Maptitude for Redistricting plan cannot be changed after a plan has been created.

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