HR: 0800h
AN: B41B-0450    [Abstracts]
TI: Simulation and verification for the expansion of the wildfire in the boreal forest
AU: * Kimura, K
EM: kimura@ssi.ist.hokudai.ac.jp
AF: Graduate School of Information Science and Technology, Hokkaido University, Kita 14, Nishi 9, Kita-ku, Sapporo, 060-0814, Japan
AU: Honma, T
EM: honma@ist.hokudai.ac.jp
AF: Graduate School of Information Science and Technology, Hokkaido University, Kita 14, Nishi 9, Kita-ku, Sapporo, 060-0814, Japan
AU: Fukuda, M
EM: mfukuda@iarc.uaf.edu
AF: International Arctic Research Center, UAF, 930 Koyukuk Drive, Fairbanks, AK 75734, United States
AB: 1. Background Frequent occurrence of wildland fires in boreal area is considered as one of major resources of greenhouse gases: by not only biomass burning but also continuing to melt the frozen soil and accelerating the resolution of the peat etc. For example, there area lot of wildland fires in Alaska. Now, the satellites of NOAA and Terra/Aqua are watching the earth and the fires are detected easily. Of course the fire detection is very important, but the influence on inhabitants is more important. Our purpose is to make the numerical simulation of the wildland fire spread in the large area. We think this is very useful to help fire fighting and reduction for the bad effects on the inhabitants and global environment such as the replace of CO2. 2. Numerical Wildfire Spread Simulation There are many type of the numerical simulation of wildfire spread. In our simulation, the wildfire velocity is based on the Rhothermel equation and other parts are made of the cell automata. The area of the wildfire is the uniform vegetation consisted of the boreal forest (Picea mariana) then the fuel factor is also uniform, we think. The origin point and the real spread of the Boundary Fire are observed by Alaska Fire Service. In this study, the comparison of the all field and the simulation is only about this fire. 3. Stop Line of the Forest Fire Spread If the forest fire simulation continue for many steps, all the forest in the simulation area is burned out because the stop lines have not been considered yet. Now we think about the stop lines with the topology and the wind direction. (Of course the rain is the best way to distinguish the forest fire. But that is neglected.) It has been proven that as a tendency in the forest fire in a past, the fire does not spread in the place like the following, and that the burn stops: (1) Windward side and down slope (2) Lee side We analyzed the coupling of them. The best parameter of the burn stop probability is the proportion of the wind speed. The proportion constant is calculated by the generic algorism. 4. Weather Condition Weather condition is very important for the wildland fire spread. When wind speed is strong, wildland fire spreads very fast, and sometimes fire leaps across a road and even a river. Usually, the weather condition was considered as the observation point data in the town near the fire. But it is not enough because the area is sometimes far away and the observation interval is loose. In our study, the mesoscale weather simulation model (MM5) is taken in the wildfire spread simulation. 5. The Simulation Results We are now validating our numerical simulation of the wildland fire. Boundary Fire is the bigger forest fire near Fairbanks, Alaska in 2004. We show the examples of the results in the poster. 6. Conclusion We constructed the numerical simulation model of wildfire spread in boreal forest. It was made of the cellular automata. The result of simulation was verified by the real data of the Boundary Fire near Fairbanks in 2004 and it is very good re-create except for fire leaps.
DE: 0466 Modeling
DE: 0468 Natural hazards
SC: Biogeosciences [B]
MN: 2007 Fall Meeting