5 Click the Definition Query tab. The Definition Query window allows you to restrict what is displayed in a map layer. In this case, we used the POP2007 attribute to limit the cities displayed to those that had a population of 250,000 or more in the year 2007. This window changes only the display and does not remove the records from the source data.
6 Click the Labels tab. The Labels window allows you to label features using an attribute from the feature attribute table. We used NAME, which is the name of cities, in a purple font and a white halo mask. We also turned labeling on by selecting the check box at the top of the form.
7 Close Layer Properties.
YOUR TURN
Examine the properties of a few more layers, but do not make any changes. When you are finished, close ArcMap but do not save any changes.
Tutorial 1-4
Using and exporting a map
Fundamentally, when you use GIS for analysis, you are observing spatial patterns related to a problem, phenomenon, or issue of interest. In this case, the phenomenon is mortality of white males from lung cancer.
In this tutorial, you will clearly see strong spatial patterns and concentrations of mortality along the southeastern coast of the United States and other locations. You can recognize some correlations on the map, based on spatial arrangement alone. For example, the band of high mortality along the eastern border of Kentucky is in that state’s coal mining belt. Perhaps the white males succumbing to lung cancer in that area tend to be coal miners.
Some of the southeastern peak areas for mortality correspond to tobacco-growing areas of Virginia, the Carolinas, and Georgia, but high-mortality areas run beyond the tobacco fields. Perhaps being near tobacco-growing areas increases the likelihood of smoking and, therefore, lung cancer. The question then becomes, how far beyond the immediate tobacco-growing areas could such an influence exist? Regardless, it cannot account for the high mortality observed along the Mississippi River.
An additional correlation is poverty, which contributes to many health problems and perhaps increases exposure to factors leading to lung cancer. A strong indicator of poverty, and the only poverty indicator available in the working US counties data, is the percentage of female-headed households with children. As an example of the effectiveness of this indicator, in Pittsburgh at the tract level, the simple correlation between percentage of female-headed households with children and the percentage of total population below the poverty line is 0.67. Now you can see if there is any visual evidence of a positive correlation between this poverty indicator and white male lung cancer incidence.
For this poverty indicator, we used a size-graduated point marker and a dichromatic color scale. We used an equal-interval numeric scale of 4 percent width, where the darker shade of green signifies the lowest-value interval and the darker shade of orange signifies the highest-value interval. Also, the larger the diameter of circular point marker used, the higher the interval of the indicator variable.
Find and export a map
1 Start ArcMap and open Tutorial1-4.mxd. Select the check box to the left of the Percentage Female-Headed Households with Children map layer in the table of contents to turn that layer on. Immediately, you can see that this variable is promising as a correlation to the male lung cancer deaths because it is high in many of the same areas where lung cancer mortality is high. The current map, however, is zoomed out too far. You need a closer look at the southeastern United States. We have built a spatial bookmark for this purpose, which you will use next, to get an uncluttered, zoomed-in view of the map. Notice that the map scale in the figure is 1:20,000,000 for the entire United States. It will be different on your screen, because your screen is likely a different physical size from ours. Make a note of your scale.
2 On the Menu bar, click Bookmarks > Southeast. Using this bookmark helps considerably. There is a visual correlation between the variables, with both tending to be high in the same areas. Clearly, further examination would require a multivariate model. We have identified some promising variables: coal production, tobacco crops, adjacency to tobacco-growing areas, and poverty. For the present, however, you need a professional-quality map that could be used in a Microsoft Word document or a Microsoft PowerPoint presentation. We have built a map layout for this purpose, which you will view next. Note that the map scale is much larger when zoomed in to 1:9,000,000, as shown in the figure.
3 On the Menu bar, click View > Layout View. The resulting map, which you will learn how to export for use in a document in chapter 3, is in layout view. ArcMap provides two general views: data view and layout view. Typically, you use data view to interact with your map data by browsing, symbolizing, and editing. You can also interact with your data in layout view, but its primary purpose is to finalize a map composition. In layout view, you can add a north arrow, a scale bar, a legend, and other map elements.
4 On the Menu bar, click File > Export Map.
5 Browse to \EsriPress\GISTHealth\MyExercises\Chapter1\ and save the map as a JPEG file, resolution 150 dpi, called Tutorial1-4YourName.jpg.
6 On the Menu bar, click Bookmarks > U.S.
7 Close ArcMap. Do not save your changes.
Learning about GIS websites
Esri offers a website for sharing maps and map layers: ArcGIS Online (http://www.arcgis.com).
ArcGIS Online is a cloud-based system for sharing your data with others and accessing shared data that others have posted. One thing you can do with ArcGIS Online is share your symbolized data with others. If you create a map in ArcMap showing the results of an analysis, you can make a layer of that data in ArcMap, then post it to the Internet on ArcGIS Online, and share it with the public or selected colleagues.
A second thing you can do with ArcGIS Online is make a web-based map, using data available on ArcGIS Online that others have posted or Esri has made available. You can share that map with the public or selected colleagues.
In the following tutorials, you will be trying out these capabilities of ArcGIS Online. First you will be posting a layer file from ArcMap. Then you will be creating and saving a webmap.
Tutorial 1-5
Creating and sharing map layers
You can use ArcGIS Online to publish maps you create in ArcGIS for Desktop on the Internet. To do so, you’ll need to create layer packages for your map layers. Here are the major steps:
1. Create a map document in ArcMap.
2. After the map is symbolized and labeled, and each layer is documented in Layer Properties using the General tab, right-click the layer and click Create Layer Package. Then choose a storage location and file name on your computer.
A layer package is an .lpk file you save locally that encapsulates both data and symbolization. Layer packages can be used in ArcMap, ArcGIS Online and ArcGIS Explorer Desktop.
Note: If you have a group layer in ArcMap, you can save the entire group layer (and all its map layers and layer symbolization) in a single layer