International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B-YF. Istanbul 2004
This information is displayed in the report pages which can be
viewed based on year or by management district. Any fire that
is currently burning can be selected from within the fire reports
and a fire status page will be displayed containing the real-time
information relevant to that fire.
The fire status page shows the real-time location of the center
of a fire or hotspot. In addition, the location of the fires can be
viewed on a reference map of Alberta, shown on the same
screen. Other information such as fire status, fire management
district and most up to date aerial photos are also shown on this
screen.
3.2.2 Trajectory Tool: The second tool that is currently
available on the WMMS is the Trajectory Tool. This tool is
capable of reporting the real-time trajectories of a spotter
aircraft’s flight path and displaying on the webpage the
locations of any spotted fires or hotspots along that flight path.
Points along the plane's trajectory are collected using the
WADGPS receiver that is mounted on the spotter aircraft and
transferred to the system in the same manner used by the
Fire/Hotspot Reporting Tool. The trajectories are then
displayed on the base map. Fires and hotspots are also recorded
during this process and any incoming fire coordinates are
uploaded to the website and marked on the base map with a fire
icon. If the fire has been extinguished but is still smoldering,
the locations of hotspots within the smoldering area will also be
automatically uploaded to the web site as the spotter aircraft
passes over.
3.2.3 Prometheus Tool: The third tool that is available on the
WMMS is the Prometheus Tool. This tool allows fire
managers to determine how a current or hypothetical fire will
propagate across the terrain. Prometheus is a wildfire modeling
program which is the result of a national interagency project
endorsed and administered by the Canadian Interagency Forest
Fire Center (Prometheus, 2004). Alberta Sustainable Resource
Development is the lead agency for this project and has
permitted the Geomatics department of the University of
Calgary to use Prometheus as a tool in its wildfire prediction
system. Prometheus is currently able to model wildfire
behavior based on topography, the Canadian standard fuel types
and the Canadian standard weather index system from the
Canadian Forest Fire Danger Rating System (CFFDRS)
(Prometheus, 2004).
Prometheus was chosen for this system since it possesses three
key advantages that no other available model has. The first
advantage is that Prometheus provides an intuitive pictorial
view of the spread of fire though the landscape. This enables
users to quickly view how the fire is spreading instead of
having to interpret textual values of rate of spread and fire
intensity. The second advantage is that Prometheus uses the
two working sub-systems of the CFFDRS in its prediction
model. This helps standardize the model since the CFFDRS is
a national system for rating the risk of forest fires in Canada.
Finally, Prometheus can be integrated into the WMMS using its
Microsoft COM (Component Object Model) interface. . The
COM interface allows easier integration of Prometheus with
other Microsoft applications, permits additions to be made to
the model and allows the model to work seamlessly through a
web browser. The CFFDRS and Prometheus COM will be
discussed in more detail in the following sections.
CFFDRS: The CFFDRS is the Canadian standard for predicting
wildfires, which was initially developed in 1968 (Hirsch, 1996).
Since then, two sub-systems have been developed to handle
fuel types, topography and weather. A third sub-system is
being developed to include risk of lightning and human caused
fires but is not operational yet. Currently, only the Fire
Weather Index (FWI) and Fire Behavior Prediction (FBP)
Systems are being used by the Prometheus COM.
The FWI system is composed of six components that model fire
behavior based on daily fuel moisture and wind effects. The
first three components deal with the moisture content of the
different layers of fuels on the forest floor. The layers are
defined as scattered litter and other fine fuels, loosely
compacted organic layers at moderate depth and deep,
compacted layers. The three remaining components of the FWI
system include predicted rate of fire spread, fuel available for
combustion and predicted head fire intensity. These six
components are calculated using the equations from (Van
Wagner, 1985) to produce qualitative FWI grid maps.
The FBP system uses fuel types and topography to calculate
quantitative predictions for select characteristics of fire
behavior (Hirsh, 1996). To use this model, input from the
following five sources is required:
1. Fueltype
o Determined using a list of sixteen general fuel types
that are some of the major fuel types in Canada
2. Weather
o Encapsulated using output from the FWI system, plus
hourly data on wind speed and direction
Topography
o Defined by percent slope and aspect
4. Foliar moisture content
o Determined using elevation, latitude, longitude and
date
5. Type and duration of prediction
o Determined using the elapsed time since the fire
began and whether it began by a point or line
ignition.
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Once these parameters are entered into the FBP system, the
system produces the primary outputs of rate of fire spread, fuel
consumption, head fire intensity and fire type. From these
parameters two dimensional views can be produced to illustrate
the fire spreading as a function of time. Once the results of
both the FWI and FBP systems are obtained they can be
combined to create a complete view of predicted fire
propagation.
Prometheus’ Component Object Model: | To create the
Prometheus COM, the Prometheus application has been
programmed into various components where each component is
capable of performing a certain task. Components are reusable
pieces of software in binary form that can be plugged into other
components from other vendors with relatively little effort.
Software components must therefore adhere to a binary external
standard. A COM builds a foundation that enables the creation
and use of reusable components by making them “component
objects". An object is a piece of software that contains the
functions that represent what the object can do and state
associated information for those functions. Objects are made
up of a data structure and some functions to manipulate that
structure. These mechanisms are independent of the other
applications that use object services and of the programming
languages used to create other objects. The COM also provides
methods for code reusability without the problems of traditional
language style implementation inheritance. To use the COM
the client must tell an object when they are using it and when
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