Creating a Census Data Map

This is a step by step tutorial on how to use online census data to show the population distribution of elderly 65+ aged people in Fairfax County. It will also show two different

ways to label features and how to use the ArcMap 9.2 Layout view to create printable maps like the one shown below.

Files you will need for this exercise. Please download these from the infoguide.

• streets.shp • fairfaxcounty.shp • ELDERPOP.dbf (census data for total population of people age 65 and up.

This is created with the “Acquiring Census Data” tutorial)

Step 1: Joining Census data to fairfaxcounty.shp • Run ArcGIS 9x and open a new empty and select “A new empty map” and click ‘OK’

• Click the “Add Data” button located on your toolbar. • Add your copy of fairfaxcounty.shp to the map. Click ‘OK’ to any prompt that may

appear. Your screen should now show a map of Fairfax County.

• Now use the “Add Data” button again to add the ELDERPOP.dbf to your map.

• In the “table of contents” on the left side of the screen, right click on the “fairfaxcounty” layer, select “Joins and Relates” then click “Join…”.

• In the drop down window for “Choose the field in this layer that the join will be based on:” select “STFID”.

• In the drop down window for “Choose the field in the table to base the join on:” select “GEO_ID2”.

• Click ‘OK’

• Open the attribute table for fairfaxcounty.shp by right-clicking on the “fairfaxcounty” layer and selecting “Open Attribute Table”. You will notice that all the data from the ELDERPOP.dbf is now joined with the fairfaxcounty.shp file.

We will now add a new field to fairfaxcounty.shp for the elderly population count.

• In the attribute table for fairfaxcounty.shp, click on “Options” then “Add Field…”

• Name the field something related to population such as “Elder_pop” then click on the drop down window for “Type:” Select “Double” and put “10” for the Precision. Click ‘OK’.

• Scroll through the attribute table until you find the newly added field. Right click on the field’s name “fairfaxcounty.Elder_pop” and select “Field calculator” or “Calculate Values” (different for ArcMap 9.1 and 9.2). Select “Yes” if a warning appears.

• In the “Field Calculator” window we are going to add up the values of all the census

data fields with population data for people of age 65+ and store that number in our new “Elder.pop” field. In the first box (top left) you will see a list of all the fields in this table.

• The lower left box (fairfaxcounty.Elder_pop =) is where we will add up the fields we want. In the first box, double click the first field labeled “ELDERPOP.P00xxxx”.

Then click the add button. Repeat this step until all the fields labeled “ELDERPOP.P00xxxx” are shown in the lower box.

• Click ‘OK’. • Now right click on the “fairfaxcounty” layer. Select “Joins and Relates” > “Remove

Join(s)” > “ELDERPOP”. Your attribute table for fairfaxcounty.shp should now have a new field that you just created containing the population values of people ages 65 and up in Fairfax County.

Step 2: Displaying the newly collected census data for elderly population. Warning: Please save your work now and regularly throughout this exercise to avoid data loss in the event of a system crash. ArcMap has no option available for file recovery if you did not save.

• Right click on “Layers” in the table of contents and select “Properties.” • Go to the “Coordinate System” tab. • In the “Select a coordinate system:” box, go to Predefined > Geographic Coordinate

Systems > North America and select North American Datum 1983. Then click ‘Apply’ and ‘OK’. This should define the coordinate system of the map. This is important to prevent errors.

• Right click on the “fairfaxcounty” layer and select “Properties”. • Go to the “Symbology” tab. • On the left side, under “Show:”, select “Quantities” and “Graduated colors”. • In the drop down window for “Value:” select “Elder_pop” (the name of the field we

created above). • Then click ‘Apply’ and ‘OK’.

Your map should now show a representation of elderly population such as the one at the beginning of this tutorial. The darker regions represent areas with 905 – 1488 residents of the age 65+ while the lighter regions represent areas with 0 – 233 residents of the age 65+, etc.

Step 3: Adding and displaying major highways.

• Go to “Add Data” and add “streetsr.shp.” This should display all of the roads in Fairfax County.

• We only want to show I-66 and I-495. To do this go to the “Properties” of “streetsr” and go to the “Definition Query” tab.

• Click on “Query Builder…” • Use the list at the top and the “Get Unique Values” option to put “"FNAME" = 'I-495'

OR "FNAME" = 'I-66'” in the lower box.

• Click ‘OK’, then ‘Apply’. • Go to the “Symbology” tab. On the left side of the window, click “Categories” then

“Unique values”. • In the drop down window for “Value Field” select “FNAME”. • Click on “Add Values…” and click “Complete List”. Add both I-66 and I-495 to the

list. Change their appearance to something more visible then click ‘Apply’.

Step 5: Displaying labels as annotations. • Right click on streetsr and go to the properties. • Go to the “Labels” tab. This is where you are going to create the labels for this layer. • Check the “Label features in this layer” box. • In the drop down box for “Label Field” select “FNAME”. • Click “Symbol” and select “U.S. Interstate HWY” from the list as shown below. • Click ‘OK’, ‘Apply’ and ‘OK’.

• Right click on streetsr in the table of contents and select “Convert Labels to

Annotations…” • A new window should appear. Select “In the map” and “Features in current extent”

then click “Convert”.

• You should now be able to select and edit each label on the screen for “streetsR”. • Resize and move the labels to the desired locations.

Step 6: Using the Layout View The Layout View in ArcMap is much like using a drawing software such as Photoshop. You can add texts, boxes, lines etc. and fit them on different sized pages. For example you can make your layout for a small 8.5”x11” paper or for a huge 3’x4’ poster and print it directly from ArcMap through a normal printer or a large plotter.

• To access the Layout View, click the small icon at the bottom of the screen, or go

to “View” at the top of your screen and click “Layout View”. • Go the “File” at the top of your screen and click “Page and Print Setup…” • Change the Orientation to Landscape and click ‘OK’. • Click once on the map and resize it to better fit the page. • At the bottom of your screen you should see a Drawing toolbar. If you do not see one,

right click somewhere on your toolbar and check the “Draw” tool.

• While you have the map selected, go to the “Fill Color” icon and change it to gray. The background of your map will change to gray.

• In the draw toolbar select the “Draw Rectangle” tool . • Create a box along the left side of the page for the title and set its background color to

a light yellow.

• Now select the “New Text” tool and make a text that reads “Fairfax County Elderly Population”

• Go to the properties of this text by either double-clicking or right-click > properties. From here you can edit the font and position of the text.

• Click on “Change Symbol” and change the font size to 36 and click ‘OK’. Then change the angle to 90 and click ‘OK’.

• Move your title to fit the yellow box on the left side of the screen.

• You can repeat this process to create as much text as you want to fill the page. For a

map, you may want text stating the source of your data, the date the map was created and by whom, the purpose of the map etc.

• To insert a north arrow and scale bar, click on “Insert” at the top menu and then select “North Arrow…”. Choose the style on the left and click ‘OK’. Then move this arrow to the desired location on your map and change the size if needed. For the scale bar, do the exact same.

• For the legend, go to “Insert” then “Legend”. Click ‘Next’ and ‘Next’ again until you reach the window for the “Legend Frame”. Make the background yellow and the border 1.0 point.

• Click ‘Next’ and then ‘Finish’. • Right click on the legend and select “Properties”. In the “Legend items” window

select “streetsR” and click “Style”. A new window should appear. • On the left select “Horizontal Single Symbol Label Only” and click ‘OK’ (see below)

• In the “Legend items:” box select “fairfaxcounty” and check the box on the right labeled “Place in new column”.

• Click “Style” for “fairfaxcounty” and select “Horizontal Single Symbol Layer Name and Label” then click ‘OK’, ‘Apply’ and ‘OK’.

• Resize the Legend to fit the bottom of your page. • Go to the properties of the “fairfaxcounty” then go the the “General” tab and change the

name of this layer to “Elderly Population”. Click ‘Apply’ and ‘OK’. That should have also changed the name in your legend automatically.

• If you have a logo, (you can copy and paste one from online), go to “Insert” then “Picture…” and browse for the logo you want to add. Move it to where you want on the page.

If you have any questions on this tutorial, please contact Joy Suh, hsuh1@gmu.edu

Created February 2008