Download the ArcView 3.x Import Extension [Zip, 4 KB]. This file has been compressed as a self-extracting zip file so that it can be downloaded more easily from the Internet. [Need help with compressed files?]

Save the file aloha.avx in your ArcView extensions directory. This directory is called EXT32 and is located inside the ESRI/AV_GIS30/ARCVIEW directory.

The import extension requires that you use a threat zone file with a .PAS suffix; the file must have no spaces in its name or pathway. The manner in which you obtain this file depends on which version of ALOHA you are using.

• ALOHA 5.4.2 or later: Use the Export Threat Zones option (in ALOHA's File menu) to save the threat zone displayed in ALOHA as a .PAS file. ALOHA will prompt you to select a name and location for the file.
• Earlier versions of ALOHA: Display a threat zone in ALOHA, then browse to the ALOHA program folder on your computer. A temporary "aloha_ftp.pas" file should be visible in this folder while the threat zone is displayed in ALOHA; if you don't see the file, make sure that you have write permissions for the ALOHA folder. It is recommended that you make a copy of the .PAS file and rename it. ALOHA deletes the "aloha_ftp.pas" file when it closes, but if you've saved the .PAS file with a different name, then you can import the threat zone into ArcView even after ALOHA is closed.

From inside ArcView, go to "File" and select "Extensions..." This will open a window with a scrollable list of available extensions. Check the "ALOHA Extension" box (near the top). If you also check the "Make Default" check box, the ALOHA icon will show up in all occurrences of ArcView. After you have made your selections, click "OK." The ALOHA application icon should now be available on the tool button bar on the view window.

Prepare the themes you want to view with the ALOHA threat zone. Make sure they are all in decimal degrees, as this is how the threat zone file will be interpreted.

Click on the ALOHA icon. A file menu window will appear, asking you to navigate to the directory where the threat zone .PAS file is stored. Double click on the .PAS file to select it. You will then be asked to indicate the theme on which you wish to place the threat zone. Scroll to the appropriate theme and click OK.

You will then be asked to name the theme for the ALOHA threat zone. You may put this into whichever directory you choose. It is advisable to maintain the .shp suffix, as the theme will also be converted to shapefiles.

Now comes the tricky part! You are asked to click on the origin of the chemical release. What is really returned to the avenue script is the current position of the mouse. So, move the mouse to the release point. You need not click. Once you are satisfied with the mouse location, press Enter on the keyboard to accept that mouse position. During this part of the process, you may move the Return Mouse Click dialog window as needed to access the point on your map where the release occurred.

The ALOHA threat zone is now drawn as its own theme in the view window. The legend shows the wind direction confidence lines, as well as the threat zone itself.

A map layout is also created. This layout provides the information fed into ALOHA regarding the type of chemical, the atmospheric conditions, the level(s) of concern, and more. You may zoom in or out of the view window to see more or less of the map in the layout window. The text and legend information are objects that can be selected, moved and/or modified as you find necessary.

Now that the threat zone has been imported, it can be treated just like any other ArcView theme. You may choose to query what parts of other themes are overlaid by the threat zone, areas within the wind direction confidence lines, and so on.

ALOHA: Visit the ALOHA overview page to learn more about this program for emergency responders and planners.
 

Questions: Contact us with questions, comments, or suggestions about ALOHA.