LESSON 4: Finding a Suitable Reserve Site

In this lesson you will be finding the best location for a new reserve. There are certain criteria that you must follow to find a new site. First, you will want your reserve to be fairly close to a road for access, so your reserve will be within 50 miles of a road. Since the majority of animals in Africa do not live in the "uninhabitable" desert, the reserve will be located outside of any deserts. The animals will need to have water nearby, so you will want the reserve to be within 200 miles of a river. Lastly, the precipitation levels on your reserve should be greater than 200 mm.

Key Terms:

Buffer: a zone of specified distance around features. It is useful for proximity analysis.
Intersect: the intersect operation preseves features only falling within two themes.

Step 1: Open ArcView: Double click the ArcView icon using the left mouse button. A new window Welcome to ArcView GIS will appear asking whether you would like to create a new project with a new View, as a blank project, or Open an existing view. Click the CANCEL button.

Step 2: Add a New View: You will notice a menu bar along the top of the ArcView window and an Untitled project window containing Views, Tables, Charts, Layouts, and Scripts. These are documents and you will use them to create a new Project. To add a new view to the project, click the Views icon once with your mouse and then click the New button.

Step 3: Set the Working Directory: The working directory designates where your files will be saved. Ask your teacher which pathname to use. Click on File in the working menu bar. A drop down menu will appear. Click Set Working Directory. The Work Directory window will appear. Type in the pathname that you will be using and click OK. This directory must be designated before you begin this project.

Step 4: Create a Project: Click on the bar at the top of the Untitled window to make it active. Click on File in the menu bar and then click Save Project As. Check to make sure that you are in the proper working directory. If the path is incorrect, return to Step 2. Replace the proj1.apr with africa4.apr and click OK. Africa4.apr should appear at the top of the project window.

Step 5: Add themes to the View and Turn Them On: Make the View1 window active and click once on the Addtheme button with your mouse. The Add Theme window will appear. Select the africa.shp file, hold the shift button down, and select precipyr.shp, riv_arc.shp, roads_rr.shp, veg2.shp, and reserve.shp. This allows you to select more than one shapefile at a time. Now click OK. These themes will be added to your view, but you will not be able to see them until you click on the box to the left of each theme. This turns them on. The colors can be changed in the legend editor if they do not show up well on your computer. Refer to Lesson 1 for instructions on the legend editor. Change the names of these themes to the following:

africa.shp = Africa
riv_arc.shp = Rivers
roads_rr.shp = Roads
veg2.shp = Vegetation
precipyr.shp = Precipitation
reserve.shp = Reserves

If you forget how to do this, refer to Lesson 1, Step 9.

Step 6: Turn on the Geoprocessing Wizard: The Geoprocessing wizard allows the program to perform spatial analysis on the themes. For more on spatial analysis, please refer to Lesson 5. To turn on the Geoprocessing Wizard, go to File and select Extensions from the drop down menu. An Extensions box will appear. Scroll down the menu until you find the Geoprocessing Wizard. Check the box to the left of this selection, and then click OK

Step 7: Creating Shapefiles: The first step to creating the new reserve will be to select all vegetation zones other than desert and precipitation greater than 200 mm. Open the attribute table for vegetation and peruse the fields. Click the query button. Double click [Zone] under Fields, then double click the not equals sign (<>). Under Values, double click "Desert" then click the "and" sign. You will also be including the "semidesert and desert" category and the "Semidesert" category.

Click New Set. The new vegetation selection will be highlighted in yellow. Make sure the view is active. Under the Theme drop down menu, choose Convert to Shapefile. A Convert Vegetation box will appear. Rename the file name newvegetation.shp, and click OK. Turn on the newvegetation theme and make it active. Double click on the colored box to bring up the Legend Editor. Under the drop down menu for Legend Type, select Unique Value. Under the drop down menu for Values Field, select Zone, and then click Apply. There are now eight categories for vegetation type. Make the Attributes of Vegetation theme active, and hit the clear selection button. Now you can turn on the new theme. Make sure the theme is active, and select Properties from the Theme drop down menu. Rename the theme newvegetation. Now open the attribute table for precipitation and peruse the fields. Click the query button. Double click [Low_p] under Fields, then double click the greater than sign (>). Under Values, double click "200", then click New Set. The precipitation greater than 200 mm selection will be highlighted in yellow. Make sure the view is active. Under the Theme drop down menu, choose Convert to Shapefile. A Convert Precipitation box will appear. Rename the file name newprecipitation.shp, and click OK. Make the Attributes of Precipitation theme active, and hit the clear selection button. Now you can turn on the new theme. Make sure the theme is active, and select Properties from the Theme drop down menu. Rename the theme newprecipitation.

Step 8: Creating Buffers: A buffer is a zone of a specified distance around features, and is useful for proximity analysis. You will need to buffer the rivers and the roads themes. First you will buffer the rivers theme.

Make sure the cities theme is active. Click Theme on the menu bar and choose Create Buffers from the drop down menu. A Create Buffers box will appear asking if you want to buffer the cities theme. Click Next. You will set a specified distance of 200 miles. Click Next. The program will ask if you want to dissolve barriers between buffers. Click Yes. Save the buffers in a new theme, and click Finish. A new theme Buffer1 of Rivers will appear. Rename the theme River buffer.

Next you will be buffering roads. Make sure the Roads theme is active. Click Theme on the menu bar and choose Create Buffers from the drop down menu. A Create Buffers box will appear asking if you want to buffer the roads theme. Click Next. You will set a specified distance of 50 miles. Click Next. The program will ask if you want to dissolve barriers between buffers. Click Yes. Save the buffers in a new theme, and click Finish. A new theme Buffer1 of Roads will appear. Rename the theme Road Buffer.

Step 9: Intersecting the New Themes: In this step you will be intersecting all of the themes together. The intersect operation preserves features falling only within both themes. You will be intersecting the newvegetation, newprecipitation, road buffer, and river buffer themes. Only two themes can be intersected at once.

The first themes to be intersected are the newvegetation and newprecipitation themes. In the View drop down menu, select Geoprocessing Wizard. A Geoprocessing box will appear. Six processing options are available. Select Intersect two themes, then click Next. You will be asked which themes to intersect. From the input theme drop down menu, select Newprecipitation. From the overlay theme drop down menu, select Newvegetation. Make sure to specify the path to the directory you are working in. Click Finish.

Turn on the new intersection theme, and rename it Precveg. This new theme contains only features shared by both Newprecipitation and Newvegetation.

The next themes to be intersected are the Road Buffer and River Buffer themes. In the View drop down menu, select Geoprocessing Wizard. A Geoprocessing box will appear. Six processing options are available. Select Intersect two themes, then click Next. You will be asked which themes to intersect. From the input theme drop down menu, select Road Buffer. From the overlay theme drop down menu, select River Buffer. Make sure to specify the path to the directory you are working in. Click Finish.Turn on the new intersection theme, and rename it Rdriv. This new theme contains only features shared by both Road Buffer and River Buffer.

The final themes to be intersected are the Precveg and the Rdriv themes. In the View drop down menu, select Geoprocessing Wizard. A Geoprocessing box will appear. Six processing options are available. Select Intersect two themes, then click Next. You will be asked which themes to intersect. From the input theme drop down menu, select Rdriv. From the overlay theme drop down menu, select Precveg. Make sure to specify the path to the directory you are working in. Click Finish. Turn on the new intersection theme, and rename it Newreserves. This new theme contains only features shared by both Rdriv and Precveg. You are not finished yet. Notice that the new theme contains lots of smaller polygons. You will dissolve some of these polygons in the next step.

Step 10: Dissolving Polygons: The dissolve function decreases the number of features in a theme by merging adjacent selected features that have some common attribute. You will be dissolving areas.

In the View drop down menu, select Geoprocessing Wizard. A Geoprocessing box will appear. Six processing options are available. Select Dissolve features based on an attribute, then click Next. You will be asked which theme to dissolve. Select Newreserves from the drop down menu. From the Select an attribute to dissolve menu, select Area. Make sure to specify the path to the directory you are working in. Click Next. You will now be asked to choose one or more additional fields and operations to be included in the output file. Select Area by Average, and click Finish. Turn on the newly intersected theme, and rename it Reserve2. Notice the difference in the amount of polygons contained in the Newreserves and Reserve2 themes.

Look at the theme tables to confirm that Reserve2 contains less polygons than Newreserves.

Step 11: Reserve Sites

Bring the Reserves theme to the top of the view and turn it on. Also turn on the Reserve2 theme. Notice which reserves fall in the area you selected for reserve sites.

Getting Familiar with Some Reserves: Many reserves fell outside the area deemed "suitable" for a potential reserve. To become familiar with some of the reserves, first label them with the label tool. Refer to Lesson 2. Let's first look at a reserve on the coast of Africa.

The Banc d'Arguin National Reserve is located in Mauritania. Half of the park is terrestrial, while the other half occurs in the maritime zone. The terrestrial portion shows similarities to the Sahara Desert. It is sparsely vegetated, and rain occurs rarely. The reserve is home to a dozen Dorcas gazelles, the jackal, fox, the sand cat, and the hyena. Desertification has caused the disappearance in this region of the leopard, Dama gazelle, Sctimitar-horned oryx, and the ostrich.

In the maritime zone, winds blow constantly. This area is home to five species of dolphin, the killer whale, the common porpoise, 4 turtle species, and the monk seal. In addition, 2 million species of bird pass through this area per year.

The Air and Tenere National Park is located in Niger. This is the largest protected area in Africa, covering 7.7 million hectares. Threats to this park include military conflict and civil disturbance. There is no permanent water in this area, but the scant rain allows 350 species of plants to survive, as well as 40 species of mammal. The mammals include several hyenas, desert ungulates, 15-20 cheetas, jackal, fox, the sand cat, olive baboons, Patas monkeys, and rodents. The panther, African wild dog, elephant, and giraffe are no longer present in this area. However, the park also hosts 165 different bird species, 1 amphibian and 18 differnt reptiles, including the monitor lizard, sand vipor, boa species, and gecko.

The Kalahari National Reserve also does not fall within the specified locations for potential reserve sites. This area contains the largest continual stretch of sand in the world. There is no standing water in this reserve. Mammals include the eland, gemsbok, springbok, hartebeest, steenbok, duiker, giraffe, kudu, warthog, hyena, jackal, and the bat-eared fox.

One national park that does fall within the potential reserve sites is the Manovo-Gounda-St Floris National Park. This park is located in the Central African Republic. The climate is tropical and semi-humid, and the vegetation falls in the savannah category (sparsely forested plains). Animals found in this park include the rhinoceros (10), elephant (2000-3000), leopard, cheetah, wild dog, shoebill, crocodile, lion, giraffe, eland, and the golden cat. Ungulates found in the park include the hartebeest, warthog, duiker, waterbuck, reedbuck, oribi, topi, hippopotamus, and the antelope.

Why did this lesson locate reserves in non-desert areas?

Step 12: Save the Project: Make the africa4.apr window active. Go to File in the ArcView menu and click Save Project in the drop down menu. Then click on File again and click on Close Project. Now you can continue on to the next lesson or exit ArcView by clicking File and then Exit.

Go Back To Home Page
Introduction
Lesson 1
Lesson 2
Lesson 3
Lesson 5
Answers
Metadata