Introduction to Spatial Data Analysis with ArcGIS
Objective
ArcGIS is used in the Inquiries text
to examine global and regional patterns using a large geographic information
dataset. Students explore the state of the world using a global dataset, which
includes information on the social and political climate that populations experience, as well as the environmental and geologic
factors that shape their country. Students will examine patterns such as the
level of civil liberties countries posses, to rates of urbanization, to the
distribution of geologic hazards such as volcanoes and earthquakes.
This exercise is intended to acquaint you with the basic
features of ArcGIS, using data on population growth
and various environmental indicators. ArcGIS is
the most commonly used software for working with geographic data sets. That
dataset that you will be working with was compiled from data from the World
Resources Institute, United States Geological Survey, United Nations Population
and Urbanization Data, the World Wildlife Federation and the CIA World Factbook.
We want you to be mindful not only of the power of map
tools, but the powerful ways in which data can be misrepresented or used to
mislead. As you create and analyze your maps, always be critical of both the
data you are using and the ways in which you are using it. This should be most
apparent to you as you create legends, which you will learn about in this
exercise.
While we will primarily use ArcGIS
to examine global and regional patterns, you may want to focus on a specific
developing country that is of interest to you.
Introduction
In this exercise you will examine the relationship between
population growth and the country’s female literacy rate. Before you
begin, it will be helpful to hypothesize what you think the relationship
between the two will be.
- Open
ArcMap 10
- Open
the Inquiries ArcGIS File
Before proceeding further, save your project. Under File, choose Save As…. Make sure the
appropriate drive is selected in the bottom right pull-down menu before you
click OK. Name the file
something that will help you remember what it is in the future (intro_ArcGIS, etc). Save each lab as a different name to
ensure that your original ArcGIS dataset is not
altered for subsequent labs. Also, it is a fact of life that computers crash
so, save intermittently as you are
working!
Below is an image indicating where a Theme/Layer is in your ArcMap window (in ArcMap 10 this is now called the Table of Contents but fuctions in the same way).
Click on the check box next to population demographics to see
a world map. It should look like Figure 1 (your colors may vary from those shown below, they are assigned randomly at first).
Figure 1
ArcGIS
interface with map of global population
Next, open the attribute table for population demographics by
right-clicking on the layer name from the layer menu and selecting open
attribute table. The attribute table associated with a given layer stores all
of the raw data used to create and normalize the maps we make and manipulate.
By scrolling through the table you can see all of the categories of data that are
available and all of the countries that the map represents. Cells that have
<Null> are categories where data is unavailable. Close the attribute
table when you are finished examining the data.
Now we want to customize the map. Copy the population demographics layer by right-clicking on it. Go to Edit --> Paste. Paste two copies of the population demographics layer at the top of the layer column. Unclick your original population demographics layer. By making copies of layers, we can always go back to the original layer if a mistake is made.
Hit "save."
Of
your two new layers at the top of the layer column, double-click on the bottom population demographics
layer. The Layer Properties window should now appear (Figure 2).
Figure 2
Layer Properties
We want to start by creating a map, which compares the
countries by the percentage of women who are literate. First click on the
General tab of the Layer Properties window and rename your layer Female Literacy Rate. Click Apply. Then
click on the Symbology tab. To illustrate the
percentage of females who are literate, on the left side of the Layer
Properties window, under Quantities, choose Graduated Color. Then choose
Female Adult Literacy Rate (percent of adult females that are literate in
2002) as the fields value.
Set your Classification to five classes. Then press the Classify button a window should appear that looks like Figure 3. In the future this is where you will change category sizes by altering the Classification Method or the Break Values in the box to the right of the histogram, for now simply click OK to return to the Layer Properties dialog box.
Figure 3
Classification
Note that it is possible to change the colors by altering the Color Ramp.
Alternatively, you can right-click on each of the symbols. Then select Properties for Selected
Symbol(s). Next, choose the fill color of your choice and select OK. When you are satisfied with the colors in
your classification field, click on OK. Note that in this dataset, the Country layer shows the outline of each
country and those countries that are colored white are in the no data class
(null data); i.e. there is no data for that country. Close the Layer Properties Window by clicking OK.
Hit "save."
Figure 4
Female Literacy Rate fields
You should now see a map of the countries of the world
where each country is coded by the percent of adult women in each country that
are literate (be sure that the top population demographics
layer is un-checked to see Female
Literacy Rate. Your map should look like Figure 5.
Figure 5
Global map of literate adult
females
For the second population demographics layer, we are
interested in looking at the population change over time. Double-click on this
layer and in the layer properties, general tab, change the name of this layer
to Population Change 2000-2005
and press Apply. Then under the Symbology tab,
classify a graduated color legend with 2000-2005 Total Average Annual
Population Change as the value field. Make sure that you have selected
three Natural Break (jenks) classes, then press the
classify button. Natural Breaks asks ArcMap to find
gaps in the data values and clump the data according to its naturally occurring
groups of values.
Next, type in 0 as the top value in the Break Values box
next to the histogram. Your Break Values should be 0, 1.9 and 4.9. Click OK.
Now manually change the graduated color legend to a patterned legend by editing each individual symbol. Right-click on each Symbol, then select Properties for Selected Symbol(s)... scroll down to the stippling. Set the 0.1 - 1.9 change to 10% Simple Hatch, and the 2.0 - 4.9 category 10% to Crosshatch as in Figure 6. Choose 10% Ordered Stipple for negative population change, make sure that the background for Ordered Stipple is transparent by clicking on the Edit Symbol... button then choosing No Color for the Background Colol. Press OK to return to the symbol Selector box, OK again to return to Layer Properties, and OK one more time to save apply your changes and return to the Map Window.
Hit "save."
Figure 6
Population change layer
Make sure the Population
Change 2000-2005 layer appears above the women’s literacy layer in the view
window. If it doesn't, click and drag the legend for Population Change
2000-2005 up to the top. Click on the "+" to the left of Population Change
2000-2005 and Female Literacy Rate to display the legends for these layers. Examine the resulting map overlay.
Question
1
What is the apparent
relationship between population change and female literacy rate? Explain how
this relationship works. Incorporate Figure 7
to help answer this question.
Figure 7
Women's
Education and Family Size in Selected Countries, 1990s
Hit "save."
Another way to explore this relationship is by
looking at the fertility rate or the number of births per woman in her lifetime
with female literacy rate. Copy the layer Female Literacy
Rate (Right-click --> Copy) and paste it at the top of the column of layers
(Edit --> Paste). Rename your layer Fertility 2005 by altering the layer name under
general tab in layer properties. Under the Symbology
tab, change the value field to Total Fertility Rate 2000-05. Next, right-click on the symbols and select Flip Symbols.
Click OK. Your map should now look like Figure 8.
Figure 8
Map of global female fertility
in 2005
Hit "save."
Since Africa stands out in this map, as well as for rates
of female literacy, explore
Within the layer properties of your two new layers, limit
the coverage to
Figure 9
Query Builder window
You can avoid typing this in (and associated typos) by double-clicking the
Continent field in the Fields window (it should appear in the formula box
below), then clicking the equal sign, and then double clicking on your
continent of choice in the Values window. All parts of the map except for
to obtain the same sized map as in Figure
10. Zoom in ArcMap by either using the maginfying glass tool, or right-clicking on the layer of interest (i.e. African Fertility 2005) and select Zoom to Layer.
Figure 10
Map of query for
When you have completed queries for both African Female Literacy and African Fertility 2005, click back and
forth between the two maps to examine whether there is a relationship between
female literacy and fertility.
Another option to examine data is to create a second data frame so you can examine two maps concurrently.
Hit "save."
First, click on the layout view
icon (
) in the
lower left of the display area to switch from the data view to the layout
view. Alternatively, go to view on the
menu bar and select Layout view. Also on the menu bar, choose Insert and select
New Data Frame. Double-click on the new data frame and rename it
The new data frame should appear with a set size in the
middle of the layout page. It should be highlighted with blue handles,
indicting that it is the active frame. The active frame is also shown in
boldface type in the layer column or table of contents. Resize both frames so
they are the same size and do not overlap on the page. Use the Zoom tool to
enlarge the African Continent inside the layout frame box without cropping any
of the continent edges. To zoom in on a map click on the zoom magnifying glass,
then draw a box around the continent you want to zoom in on.
Next, click on the African
Fertility 2005 layer on the layer column and drag it down into the Africa data frame (this is the line
saying “
To do this, right-click on the
In your final maps you must include an informative title, a legend, your name and date, a scale bar, and a north arrow, and data source citation (Important: All of these features should be included in every map you make in this class). Select View --> Zoom layout to increase the size of your maps. You can add relevant features to the map by selecting Insert --> Title, Legend etc from the menu bar. Note that you can only insert a legend for the selected data frame. To select either data frame, right click on its title in the Table of Contents and click Activate. See figure 11 for an example comparing two data views.
Hit "save."
Figure
11
Comparing data frames
Saving maps as Jpeg (.jpg) files: Before inserting your maps into a word document, it is best to export them as jpeg (.jpg) files.
Directions to do this:
- In layout view, go to File --> Export Map…
- Find your desired saving location (i.e. IFS Space), designate a file name, scroll through the ‘save as type’ options until you find the ‘JPEG (*.jpg)’ option
- Hit ‘Save’
Question 1 (find above)
Now choose one country in 
) and
clicking on the country of interest.
Question
2
Is there a general relationship
between African female literacy rate and total fertility rate? Name the African
country that you selected to examine. What are the rates of female fertility
and literacy for that country?
Question
3
Go to the CIA World Factbook (http://www.cia.gov/cia/publications/factbook/)
and look up more information about the African country you selected. Use this
information to determine some of the reasons behind the country’s fertility and
literacy rates. Write a paragraph about the country you selected examining
these relationships.
Turn In:
A word document (named Lab2_uniquename.doc) including:
- Your answers to the 3 questions in 3-5 sentences each
- A jpg image of your map of African fertility and literacy rates.
Summary of ArcGIS
In this exercise we have developed skills to create and
navigate views, create and edit legends, choose data classification types and
create data queries. This information will be important for other ArcGIS exercises.
Sources
http://www.prb.org/Content/NavigationMenu/PRB/Educators/Human_Population/Women/The_Status_of_Women1.htm