About Geographic Selection

The first step in generating an AirData report or map is selecting a geographic area. You may select a geographic area by clicking on a map or by choosing from a list. This Web page explains how to do that.

An AirData report or map can include only one type of geographic area at a time. For example, you may produce a report for several states or for several counties, but you may not select both states and counties. To make geographic selections you first choose a type of geographic area, and then select one or more areas of that type.

These geographic area types are available for AirData reports and maps:

United States - includes District of Columbia, Puerto Rico, and U.S. Virgin Islands
EPA Region
State
County - or equivalent (parish, independent city, etc.)
Metropolitan Statistical Area (MSA)
Consolidated Metropolitan Statistical Area (CMSA)
ZIP Code

Most reports and maps are compatible with the first four area types. A few reports and maps offer MSA and ZIP code area types. No reports or maps are available for CMSA area type, but it may be converted to the equivalent collection of counties with the "amend selection" option, as described in Using Lists below.

Using the Map

Near the top of the Geographic Selection Web page is an interactive U.S. map. You may click on the map with your mouse to select geographic areas.

Thumbnail image of AirData geographic selection map

If your browser displays a frame containing only the text "Click here to get the plugin," then the Adobe Flash™ Player software necessary for using the map is not installed on your computer. You will need to select a geographic area from the lists displayed at the bottom of the page, or install the free Flash Player software, which you may obtain from Adobe's Web site.

1 Select Geographic Area Type

With the interactive map, you may select four geographic area types: United States, EPA region, state, or county. These area types are listed above the map, beside the words Select By. To choose an area type, click on its name or radio button. A filled radio button indicates which area type is selected. The default geographic area type is State -- clicking on the map will select a state.

The part of the AirData selection map used to choose geographic area type

After you select a geographic area type, the map changes to show areas of that type. (If you have a slow Internet connection, it may take a few seconds for the new map to load.) For example, if you select EPA Region as the area type, the map shows states grouped by region. If you select County, the map shows states. Click on a state to get a map of counties for that state.

2 Select Geographic Areas

A state is highlighted as mouse pointer moves over it After picking a geographic area type, move your mouse pointer over the map. The area under the mouse pointer changes to a yellow highlight color and its name displays next to the mouse pointer.

County shape in map is highlighted when mouse moves over county name in list Alternatively, you may move your mouse pointer over the names of geographic areas, displayed in the Available Areas list beside the map. As you move over a name, the name and the corresponding area in the map are highlighted. Names are listed alphabetically. You may scroll the Available Areas list up or down by clicking on the red arrows displayed under the list.

Selected counties have red dots and their names are listed To select an area, highlight it and click your primary mouse button once. A red dot appears on the map to indicate the area is selected, and its name is added to the Selected Areas list beside the map. To deselect an area, click on the map or the name a second time. Each click switches an area between selected and not selected.

You may select multiple areas: up to 10 states or counties, up to 4 EPA regions. You can select counties in more than one state by repeating these steps for each state:

Click on County geographic area type above the map.
Choose a state by clicking on the map or the list of state names.
Select one or more counties in that state.

You may zoom (enlarge) the map to facilitate choosing small geographic areas. To enlarge the map, click on the large + (plus) symbol in the top right corner of the interactive map, next to the word Zoom. To reduce the map size, click on the large - (minus) symbol. To return to the original map size, click on the word Reset. To move an enlarged map within the viewing window, use keyboard arrow keys.

The part of the geographic selection map used to enlarge image size

3 Conclude Geographic Selection

The GO button concludes geographic selection When you have finished selecting geographic areas, click the Go! button in the lower right corner, below the Selected Areas list. (This step is omitted when selecting the United States.)

Next, your browser displays a list of AirData reports and maps that are available for the type of geographic area you selected. Choose a report or map by clicking on its name.

Using Lists of Geographic Areas

The AirData Geographic Selection Web page includes lists that you may use to select geographic areas, instead of using the interactive map. To learn how to use selection lists, please see How to Select...

To select geographic areas from a list:

1. Click the radio button beside the type of geographic area you want to select. The default area type is State.

2. Choose one or more of the geographic area names listed. The How to Select... page explains how to select multiple choices from a list.

3. Click the Go button below the lists.

After you complete these steps, your browser will display a list of AirData reports and maps available for the geographic area type you selected, except when you are selecting a county.

County selection is a two-step process. First you pick the state(s) in which the desired counties are located, using the steps described above. Then your browser displays the names of all counties in the selected state(s). Choose the names of the desired counties, and activate (click) the Select County button, which is below the county names list.

A MSA or CMSA selection may be amended by omitting counties within or adding counties around the metropolitan area. The amend selection option enables and disables this feature. It is enabled (checked) by default. After you click the Go button, your browser displays a Web page with which you choose counties in and around the MSA or CMSA you selected.

Using the amend selection option changes the geographic area type from MSA/CMSA to county. That change affects which reports and maps are available. No AirData reports or maps are available for CMSA geographic area type, so if you select a CMSA you must enable the amend selection option. An AQI Chart is compatible only with a single MSA or a single county. If you want to produce an AQI Chart for an MSA, you must disable the amend selection option. Most other AirData reports and maps are compatible with county geographic area type, which results from amending a MSA/CMSA selection. This means you can generate most AirData reports and maps for an MSA or CMSA, even though the reports/maps will identify the geographic area as a collection of counties rather than the original MSA or CMSA.