Web-based mapping applications in response to wildland fire
Some common misconceptions about GeoMAC are that: 1) GeoMAC can tell you if your
house has burned. This is false because the site uses small-scale data, there is not enough
detail to determine whether individual structures have been affected by a fire. 2) GeoMAC is
used by incident commanders to fight fires. Again this is false, it is used to provide a strategic
overview of where large fires are located. 3) GeoMAC is a USGS project. GeoMAC is a NIFC
project; it is housed at the Rocky Mountain Mapping Center in Denver, CO.
Figure 2: GeoMAC overview
Once in the application, the large fires are displayed across the landscape (figure 2). This data
is from the NIFC database in Kansas City. This screen provides a wealth of information
showing fires in relation to other fires across the continental US and how they are dispersed.
The size of the triangle is relational to the size of the fire. The public never before had access
to this type of visual interpretation of a wildland fire season. The information about the
location of fires was in textual reports; fire managers kept track of fire locations with stickpins
or magnets on maps on office walls. A regional manager would have an idea of the fire
situation in his region but perhaps not in the adjoining region.
GeoMAC has a set of tools used to navigate the information available on the site. Access to a
particular fire can be done by using the ‘Zoom In’ tool and dragging a box on the screen. The
‘Jump to Fire’ tool allows users to choose the fire of interest from a drop-down list and center
the chosen fire within the display screen. Other tools for navigating the site include ‘Zoom
Out’ and ‘Pan’. The site also allows access to textual information (attributes) about features.
Using the identify or hyperlink tools will display this information.
The power of a web-mapping application lies in the data integration and display. The
GeoMAC data is stored in ArcSDE locally at RMMC. More layers of information are
available as you ‘Zoom’ into a location. Zooming into larger scale, immediately more
information is available. These layers can now be made visible in any combination the user
wants. In Figure 3, the fire perimeter, Remote Access Weather stations (RAWS), road shields
and cities have been made visible. The Active layer is the situation fire. Only one layer can be
active at a time, the only layer upon which the ‘Identity’ tool can be used. In the lower middle
of the page is the result of clicking on identity and then clicking on the green triangle. The
information displayed is the cause, acres, and location of the Hayman fire. Scrolling to the
right will reveal more information. The view shows the RAWS stations at the north and south
ends of the fire. The names of the stations are immediately available, but instead of having to
access another website to find out the weather information the user can use the hyperlink tool
and directly access the data. The weather data is updated every hour and, now because of the
integration of the data and links to databases, the user has direct access to critical weather
information. The Sit Report data works the same way, with a direct link to NIFC’s database
for more information.
Figure 3: GeoMAC with additional layers visible
One of the outstanding components of the GeoMAC site is its display of dynamic data layers.
The Thermal Advanced Very High Resolution Radiometer (AVHRR) and the Moderate
Resolution Imaging Spectroradiometer (MODIS) are thermal images used to depict fire
locations. The data is symbolized with red being the most recent to orange to yellow. Due to
download schedules and processing times the ‘most recent’ data is usually 12 hours old. This
data is used to predict fire movement. The AVHRR and MODIS data are uploaded daily using
batch processes. The batch processes retrieve and load information from remote sites as new
information becomes available. The Urban Interface layer is derived from the Defense
Meteorological Satellite Program (DMSP) which detects faint sources of visible-near infrared
emissions including cities and towns.
A perimeter upload form is available on the site for field personnel to upload fire perimeters.
This form is a mechanism to standardize and streamline accessing the data. The fire perimeter
layer is still processed manually, due to standardization issues. An additional benefit of having
the fire perimeters displayed on the site is that the site is now a central location for fire
perimeters. After fire season there are numerous requests for the fire perimeter data from the
media, scientists, and students for their projects. Another layer in the application is the
inactive fire layer. This is a record of all the fires that burned during a season, the inactive fires
are color coded as to cause with black indicating lightening and red indicating human causes.
This is another data layer in high demand at the end of a fire season.
Conclusion
The use of web-based mapping applications, GeoMAC in particular, as a wildland fire
management tool for evaluating and assessing resources at risk has shown great success. The
public has shown a tremendous interest in GeoMAC as a source of wildland fire information.
The GeoMAC website experienced over 50 million requests during the 2002 fire season. By
integrating various data sets into a single source and making the information available via the
world-wide web people are able to obtain more information than ever before about the
potential risks posed by wildland fires to lives and property.
