When ArcGIS starts up, you will see themes running down the left in a column and a map of the world in the view window. If there is no map displayed click on the small gray box in the upper left hand corner of a theme. Figure AII.1 shows the Inquiries in Global Change data frame.
View in ArcGIS
For each theme that we work with (e.g. population, energy), there will be a database file (.mdb). The database files are spreadsheets that associate spatial data with map features (in this case, countries of the world). They can be opened in spreadsheet applications like Excel.
When you create and analyze maps in ArcGIS, you will want to save ArcMap files (.mxd) to your directory. Project files do not actually contain data or geographic references. They are simply links to various themes, and instructions for how to display them. A project file may contain views, tables, charts, and layouts.
When you first start ArcGIS, a new untitled ArcMap window is opened. You may either begin a new project (the default option) or open an existing ArcMap project file.
To view one or more themes select the Data Frame icon in the project window to make it active. A data frame (as in data frame Figure AII.1) displays a collection of themes and your world map. You change your map to your specifications in a view. A table is a database file that can be edited, queried or joined with other tables. A chart is a pie graph, histogram or other type of graph representation of a table. A layout is a map presentation, complete with a compass arrow, scale bar and legends. You may either print a layout or save it as a graphics file.
After a theme is activated, you will generally want to change the display so that the map is colored in a way that represents the data of interest. This is done by editing the map’s layer properties. You have the option of saving your legend to a legend file (.avl), and should do so if you plan to use the same legend again, or if it took a long time to create.
· The Manual classification method allows the user to choose where each break occurs manually.
· The default classification method is Natural breaks (Jenks), which finds groupings and patterns inherent in your data.
· The Equal Interval method divides the range of attribute values into equal sized sub-ranges.
· The Defined Interval method divides the range of attribute values into an interval that you select.
· In the Quantile classification method, each class contains the same number of features. Quantiles are best suited for data that does not have disproportionate numbers of features with similar values.
· With Equal Area classification, data are grouped such that the total area of the polygons in each class is approximately the same.
· The Standard Deviation classification method divides the attribute values by the standard deviation for the data.
Symbol Selector window
The Symbol Selector allows you to choose a pattern or color for polygon shading. Choose Hollow for transparent symbol shading. Patterns are useful when overlaying two or more themes. Select Properties to look at the fills in more detail.
ArcGIS data can often be manipulated by right-clicking on the theme name (Figure AII.6), symbol of interest (Figure AII.7) or within the attribute table (Figure AII.8).
Window of options available from right-clicking on the theme name
Window of options available from right-clicking on the symbols within the layer properties window
Window of options available from right-clicking on the category name within the attribute table
The ArcGIS toolbar contains a set of tools that are used to view and manipulate data frames, layouts and charts. Toolbars can be customized by selecting View à Toolbars.
ArcGIS toolbar example
By hovering over each symbol with the mouse, a box will appear that tells the user what each tool is used for. Examples of selected tools are below:
Identify tool is used to display the attribute values of a feature shown in a view, table or chart. With the WRI maps, you can use it to click on a country and find out its name and associated data.
Pointer tool is used to select, move and resize graphics. It is the default tool option, but you will use it most for editing layouts.
Zoom in tool is used to zoom in on an area of a view or layout that you define by clicking on a point, or dragging a box with the mouse.
Zoom out tool is used to zoom out on a view or layout, centered on a position you choose by clicking on a point.
Pan tool lets you pan a view or layout by dragging the display in any direction with the mouse.
Measure tool measures distance on a view. After clicking on the tool button, click on a point, drag the mouse, and release on the second point. The distance is indicated on the bottom of the screen, in the distance units you set in the view properties dialogue box.
Zoom to Full Extent: Zooms to the full extent (size) of all themes in a view.
Zoom In: Zooms in on the center of a view or layout by a factor of two.
Zoom Out: Zooms out from the center of a view or layout by a factor of two.
Querying allows you to limit the global data set to only those elements you select. For example, you may want to select a certain continent.
Within the Layer Properties window, click on the Definition
Query tab and then click on the Query Builder button. In the Query Builder
window (Figure AII.10), double-click on Continent. Then click on the Get Unique Values button. This should bring up the different continents
of the world. Use the query tool button to define the Theme by the
countries located in a particular continent with the following syntax:
"CONTINENT" = '
Query Builder window
You can avoid typing this in 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 access and edit the data associated with your themes, you need to work with tables.
Right-click on the theme name of interest and select open attribute table.
The join command allows you to merge two tables within your project. The database files will not be changed, but whenever that particular project is opened, the tables will be joined.
Joining data tables
For any field in a table, you can obtain the following statistics: sum, count, mean, maximum, minimum, range, variance and standard deviation. These statistics can be helpful in determining what type of classification to use in a legend.
To edit the data in the attribute table, or to add new data (i.e) replace a null value in the dataset.
Layouts can be used to prepare views, charts, tables, and other graphics for output from ArcGIS. Select View à Layout View to change from the Data View to the Layout View.
For presentation purposes, you may want to create a JPEG map of your layout. A layout JPEG typically may include a title and legend.
Example of a JPEG layout
Layout edits are generally performed with the same set of tools that you would modify the data view. Use the Insert button to add titles, graphics, charts and text to your layout. When you are satisfied with your layout go to File à Export Map. Save your file as a JPEG. Navigate to your new JPEG view and print it. These JPEGs can be used in PowerPoint presentations or any word document.
To do this, open the layer properties window of the theme of interest. Create a Definition Query for the particular region of interest. Next, open the Attribute table of the queried theme. You should only see countries in the table that are present in that region. At the bottom of the attribute table, click on the Options button and select Create Graph (Figure 8.b.3).
Select a column graph and choose next. Uncheck all categories in the middle lower box, then check the box next the emissions category that you would like to graph (Figure 8.b.4). Click on the next button.
Selecting the category to graph
Click on next button and choose an appropriate title for the graph. Check all three boxes on the left side below the title and subtitle. Next, click on the Advanced Options button and insert appropriate axes labels (Figure 8.b.5) and click on Apply Now. Next, click on the trends tab and insert a mean line on the graph and hit OK.
Selecting the category to graph
Lastly, make sure that the three buttons are checked underneath the title and subtitle. In addition, make sure that the Show Graph on Layout button is checked (Figure 8.b.5). Click on the Finish button. The chart should be visible on the layout. Resize the chart to fit in the bottom layout box.
The final step to inserting a graph in the layout
When you are finished with your layout, you can export your layout map as a JPEG under File à Export Map. Make sure to save your map as a JPEG.
Example JPEG Layout
ArcGIS's help system is very user-friendly. To find out more information about any ArcGIS feature, simply click on the help button and then the toolbar button or menu item of interest. To search for help on a particular subject, go to the searchable help index by selecting Help and then Help Topics from any menu.