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Exploring Africa's Physical and Cultural Geography Using ArcGIS

Activity 1: Physical Geography

Instructions for Students

Goal: In this lesson, you will create 4 maps in ArcGIS using relief, climate, precipitation, and vegetation data. These maps will be used to answer questions about the characteristics of the physical environment of Africa.

GIS Skills Involved: Adding, displaying, and labeling data layers, and creating maps within a GIS.

Materials: To complete this lesson you will need ArcGIS software and the Africa Lesson data (Download the Data for Activities 1-3).

Africa map

Step 1. Let’s make a map in ArcGIS and analyze it using relief data. Open ArcGIS and click "OK" to open a new empty map. Use the Add Data tool Add Data icon to add the following shapefiles (navigate to the folder where you saved the Africa Lesson data and hold down the Ctrl key to add more than one shapefile at a time): lakes.shp, country.shp, relief.shp, and rivers.shp. (You may get a message saying the data is missing spatial reference information. Click "OK").

Step 2.Some of your layers might be hidden underneath other layers. Move the layers by clicking and dragging them up or down so they are in the following order – lakes, rivers, country, and relief.

Step 3.Make the country shapefile transparent so the relief shapefile is visible underneath. Access the Layers Properties by double-clicking on the country layer. Click the "Symbology" tab and click on the colored box to access the "Symbol Selector". Choose "Hollow" and click "OK". Click "OK" one more time to close the Layer Properties box.

Step 4. We will now display the relief values. Double-click on the relief layer to access the Layer Properties. Click on the "Symbology" tab and click "Categories" —> "Unique Values". Click the drop down arrow next to "Values Field" and select "Relief" (not "Relief_"). Click "Add All Values" and "OK" to close the Layer Properties box. Notice the colors on the map have changed and now represent the different relief types (high mountains, low plains, etc).

Image of Layer Properties window

Step 5. The Rivers are hard to see so make them bright blue with thicker lines. Double-click the Rivers layer to access the Layer Properties. Click the Symbology tab and click in the symbol box with the line to access the "Symbol Selector". Change the color to a bright blue and change the width to 2 and click "OK". Click "OK" one more time to close the Layer Properties window.

Step 6. The Lakes are also hard to see. Double-click the Lakes layer to access the Layer Properties. Change the lakes to solid dark blue the same way you did with the rivers.

Step 7. Answer the following questions using this map setup.

A) In which countries are the high mountains of the African continent located (to see the country name click on the Identify tool Identify tool icon and then click on the country)?

B) Describe the path the following rivers take to their ocean outlet (north, southwest, etc). For this step you will need to turn the river labels on. Double click on the Rivers layer and click the "Labels" tab. Put a check mark in the box next to "Label features in this layer" and select "Name" for the label field. Click "OK". Use your zoom tools zoom tool icon to zoom in and out of the map to see the rivers better.

   1. Zambezi

   2. Nile

Step 8.Save this map and name it "Relief". Go to the File menu and click "Save As". Name your map Relief and click "Save".

Step 9. Now let’s make a map and analyze it using Climate belt data. From the File menu click "New"—>"OK" to open a new document. Use the Add Data tool Add Data icon to add the following shapefiles: belt.shp, lakes.shp, rivers.shp, and country.shp.

Step 10. Repeat Steps 2-6 (using belt instead of relief).

Step 11. Answer the following questions using this map setup:

   C) In which belt do the fewest rivers begin (ex: equatorial, intrazonal, etc)?

 

   D) In which belt do the most rivers begin?

 

Step 12.Save this map and name it "Climate". Go to the File menu and click "Save As". Name your map Climate and click "Save".

Step 13.Now let’s make a map and analyze it using Precipitation data. From the File menu click "New"—>"OK" to open a new document. Use the Add Data tool to add the following shapefiles: precipyr.shp, lakes.shp, rivers.shp, and country.shp.

Step 14. Repeat Steps 2, 3, 5 and 6 (using precipyr instead of relief).

Step 15. To display the precipitation data, double-click on precipyr to access the Layer Properties. Click on the "Symbology" tab and click "Quantities" —> "Graduated Color". Pull down the value field and select "low_p." Click "OK" to close the Layer Properties box.

Step 16. Answer the following questions using this map setup.

E) Using the parameters detailed below, list countries with low precipitation (desert areas). For this step you will need to use the Identify tool (see Step 7 Question A) or turn the country labels on (see Step 7 Question B).

   1. List 2 countries in the northern section of the continent.

 

   2. List 2 countries in the eastern section of the continent.

 

F) In which precipitation belt do most rivers begin (ex: 0-200, 201-600, etc)?

 

Step 17. Save this map and name it "Precipitation". Go to the File menu and click "Save As". Name your map Precipitation and click "Save".

Step 18.Now let’s make a map and analyze it using Vegetation and Relief data. Open the relief map you created in Steps 1-6 by going to File —>"Open" —>"Relief.mxd". Use the Add Data tool Add Data icon to add veget.shp to the map.

Step 19. To display the vegetation data, double click on the layer to access the Layer Properties. Click on the "Symbology" tab and click "Categories" —> "Unique Values". Click the drop down arrow next to "Values Field" and select "vegtype". Click "Add All Values" and "OK" to close the Layer Properties box.

Step 20. Arrange the layers so the vegetation layer is below the relief layer. By checking and unchecking the box next to the relief layer, we can compare the layers to answer the following questions:

G) Use the Zoom Tools zoom tool icon to zoom in on North Africa. What are the vegetation types in the northern most section of the country (Algeria and Morocco)? Hint - You may need to turn the country labels on (See Step 7 Question B).

 

H) What is the dominant relief feature of the grasslands?

 

Step 21. Go to the File menu and click "Save As". Name your map Vegetation and click "Save". Exit ArcGIS.

*** End of Africa Activity 1 for ArcGIS ***

 

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