Mapping D.C. Tract Level Population Data

Exercise: Create a map of the District of Columbia at the 2000 census tract level illustrating particular population variables.  This will be accomplished using GeoLytics, a census data and map layer product, and ArcGIS 9, a GIS (Geographic Information System) mapping software package.

Part 1.  GeoLytics

Step 1.  Creating a census map layer using GeoLytics.

Insert the appropriate CensusCD 2000 Long Form SF3 CD for your state, in the drive.

Under Start, Programs, scroll down to Census CD. Choose Census CD 2000 Long Form.

 

Step 2.  Choose File, New Request File. Enter a unique name for your file. OK.

Step 3.  Choose Area, Geographic Area, States, Click on District of Columbia and then click the done button.                                                                                                                                                                                                                                                 

Step 4.  Choose Subarea, Tracts.        

Step 5.  Choose Counts, Population 1 and Housing 1 contains data from the national to the block group level. Population 2 and Housing 2, have data from the national to the tract level.  Scroll down the list of variables and choose one for your project. Example: Family Income. A specific breakdown of the data appears in the window below.  Choose the range or ranges that are needed. Example: Income under $20.000.00. The choices appear in the Selected window. Click the done button.

Step 6.  Choose Run.  Click Map. A state map of census tracts will be created. The window on the right contains the variables that wre chosen and the codes used to identify them.  A code key list is saved with the map and can be printed out with Word for later reference.

Step 7.  Choose File in the map window. Choose Export to ArcView’s Shape.  The map is saved to:  C:/SF3200.

Close the GeoLytics windows.                                                                                                                                                                         

Part 2. 

ArcGIS 8.3

Step 1.  Open the ArcMap program by clicking on the ArcGIS 8.3 icon on the desktop.

Choose A new empty map from the opening screen. Ok.

   

Step 2.  Choose the yellow Add Data button located right under Help on the screen.

Step 3.   From C:/, scroll through the folders to the SF32000 folder and choose the .shp file that you created in GeoLytics. Click Add.  Click in the small white box to the left of the layer name to open the map.

Step 4.  Double click on the layer to open the Layer Properties. Click on the Symbology tab.  In the Show: window on the left, choose Quantities. Click Graduated colors.

In the Fields box click in the Value: window and choose the field that you want to display.  In this case the field is P052002, the code for income under $10,000.

In the Classification box on the upper right, you can change the number of classes from the default of 5 to any number. You may also press the Classify…button and modify how the classes are arranged. When done, click Apply. You now have a map displaying the variables that were created in GeoLytics.  In this example, the map shows D.C. tracts with a breakdown of households with less than $10,000.00 income.