ALOHA ArcView 3.x Import Extension

The ALOHA ArcView 3.x Import Extension allows you to import ALOHA threat zones into ArcView 3.x. This tool is no longer being updated, but it will continue to be available for download in its current version.

Note: In versions of ALOHA prior to 5.4, the term footprint was used instead of threat zone. This extension uses the older footprint terminology.

Downloading the Import Extension

To download the ArcView 3.x Import Extension, click on the download link at right. This file is in zipped (compressed) format so that it can be downloaded quickly. Uncompress the alohaavx.zip file and save the file aloha.avx in your ArcView extensions directory. (You can use WinZip or StuffIt Expander to uncompress this file if your browser doesn't do that automatically.)

Using the Import Extension

When a threat zone (footprint) is displayed in ALOHA, a file called alo_ftp.pas is created and placed in the ALOHA directory. This file will be deleted when ALOHA is shut down, so it is best to rename the file in case you want to import the threat zone into ArcView after ALOHA is off. Be sure, however, to retain the .pas suffix so ArcView will recognize the file as an ALOHA threat zone.

To use the ALOHA extension in ArcView, put aloha.avx in your ArcView extensions directory. Launch ArcView from the File menu on the Project window, and select the Extensions option. The ALOHA Extension should appear in the scrollable list. Check the checkbox to add the extension to your current project. When the extension is added, an ALOHA hula girl icon will be added to the button bar of 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 shape files.

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.