Wildfires are uncontrolled fires in the wilderness and forests, that can create widespread destruction and havoc because of their ability to jump gaps, rivers and firebreaks. In recent years, wildfires have become issues of national concern due to the extensive damage caused in urban areas close to wilderness. Moreover various other atmospheric and environmental effects have also been perceived in recent times, that are of grave concern to scientists worldwide. So wildfires are being studied for occurrence patterns to devise strategies for detection, prevention and supression.
In layman terms, wildfire modeling is the study of wildfire behavioural patterns and how they influence the atmosphere, using computer simulation or mathematical modelling. From examining the ’cause and effect’ principle to complex physical and computational variables, wildfire modelling helps in predicting the incidence, spread and intensity of wildfires. This enables to take precautionary measures for safeguarding of human life, property, ecosystems, watershed and air quality. For a wildfre’s shape essentially starts out the same everywhere in the world.
Wildfire modeling uses statistical methods for analysis of wildfire bahaviour. This helps to know the speed and direction of fires, the heat generated, fire whirls and fire transitions from surface to tree crowns. Recently, wildfire modelling is also being used to gauge the effects on the ecology and hydrology, as well as tree mortality and degree of pollution.
Wildfire modeling involves two chief modelling methods, namely EMPERICAL and PHYSICAL.
WILDFIRE MODELING : EMPERICAL MODELS
The emperical models draw from past experiences and proven gut feelings to incorporate the same in future predictions. Thus, the first-hand experience and analysis, as well as the acumen of local forest range officers, firefighters, weather offices and fire analysts are taken into account in this method of wildfire modeling. While this model relies upon subjective data, the same is embedded in computational form.
Both two-dimensional and sophisticated three-dimensional applications are used for developing quick estimates of vital information like flame length, fireline intensity and fire-spread rate. Two-dimensional models like the FARSITE and Prometheus, using the Huygens principle of wave propagation, help to apply semi-emperical fire-spread equations to arrive at conclusive data.
WILDFIRE MODELING : PHYSICALLY BASED MODELS
Some physically based two-dimensional fire-spread models make use of conservation laws, while other complex physical models combine computational fluid dynamics to wildfire components for a better understanding of wildlife behaviour. These models are based on physical principles and distinguish between physical mechanisms for heat transfer.
WILDFIRE MODELING : USE OF GIS (Geographic Information System)
Also known as Wildfire information system, this type of wildfire modeling uses the three domains of semantics, time and space. It is a GIS data model, that supports both spatial and temporal query, analysis and modeling. These are Wildfire conseptual modeling using space-time basis.
HOW IS WILDFIRE MODELING USEFUL
Wildfires are here to stay. Understanding them and creating models that predict how they interact with the atmosphere can help us live more safely with wildfires. Models can be used to plan prescribed burns that reduce fuel buildups, and thus help to prevent flames from escaping onto adjoining lands and smoke from drifting into populated areas. Models can also be used to predict where a fire will go and when terrain, weather, and fuel conditions can combine to produce dangerous fire behavior.
Wildfire modeling serves a dual purpose
* of prediction and possible prevention
* and of suppression
Just like computer models assist meteorologists and climatologists to forecast weather and predict possible climate changes, wildfire models thus help scientists, climatologists, fire analysts and local administrators to study the erratic fire beahviours and use them to balance both the threat and benefits to wildfire. At NCAR (National Centre for Atmospheric Research, U.S.A.), wildfire models have being used successfully created for such prediction and policy implementation.