In Lesson 2 you made a map showing patterns of population density in Africa, which gave you an idea of what population densities are like now. How do you think  population density patterns will change in the future?  The first step in to answering this question is to examine population growth rates.
 
 

Step 1: Join Attribute Tables

Open the Growth view and turn on the Growth Rate theme. Open the Growth Rate attribute table and scroll through the data.  As you can see, there is no attribute data for growth rates.  Fortunately, you found another source of growth rate data that can be linked to your attribute table.  This will allow you to compare current growth rates throughout Africa.

Go to the Population project window and click on  .  Select the growth.dbf file, click , and the Growth.dbf table will open automatically.

Now that you have both attribute tables open, you can link them. Make the Growth.dbf table active and click on the fips_code field (the field heading will turn gray when activated).  Then, make the Growth Rate attribute table active and click on the fips_code column to make it active (the fips_code column is now active in both attribute tables).  Move the mouse to the ArcView Toolbar and click on the  button to join the two tables. The growth.dbf table will automatically disappear leaving only the Growth Rate attribute table.* Check to make sure that the tables were successfully joined by scrolling all the way to the right in the Growth Rate attribute table. The three new growth rate fields should be the last columns in the table.  Close the table when you are finished.

*Trouble Shoot: Pay attention to the order in which the fields are selected above.  If your tables join, but Growth Rate disappears instead of growth.dbf, then you have accidentally switched the order. Go to Table in the ArcView menu, Remove All Joins,  and try again.

Step 2: Make a Map Showing Growth Rates

Now that you have data concerning growth rate patterns in Africa you will have to edit your legend to show this attribute.  Double click on the Growth Rate theme to open the Legend Editor.  Click on the  button next to Legend Type and select Graduated Color.  Move the mouse to Classification Field, click on the  button, and select Grw2000.  This tells ArcView that you want to make a map showing current growth rates.

Notice that the number of classes and the colors are automatically set for you.  Since you only want 4 classes,  click on the  button, set the number of classes to 4, and click .  If you would like to edit the colors,  move the mouse down to Color Ramps, click on the  button, and select a new color scheme.
 
 

Sometimes it helps to view the Statistics for the attribute before you set the range of values.  To view the statistics for growth rate, click on .

What is the maximum growth rate?_________________

What is the minimum growth rate?_________________

Now that you have looked at the Statistics for Grwrate, you know what the range of values is.  Click  to close the Statistics window.  To edit the Values, move the mouse to the first box under  and click once to place the cursor in the box.  Now you can change each of the values.  When you are finished your Legend Editor should look similar to this, although the colors may be different.

Click  and close the Legend Editor.  Turn on the Pop Density theme and move it to the top of the Legend.  Your map should look something like this.

Close the Growth view.

If you have time, go to the  Student Information   page and click on the  icon.  This will take you to an interactive U.S. Census Bureau web site that constructs population pyramids for most of the countries in the world. Look at some of the population pyramids for African countries.

Key Terms
Lesson 1: Introduction to ArcView
Lesson 2: Population Density
Lesson 4: Population Distribution
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