Study On Compound Suppression Technique And Emergency Eafety Measure In Forest Fire Fighting

Forest fire is one of the disasters, which happened broadly, destroyed tremendously, were rescued extremely difficultly all over the world. It didn't result forest area reduced sharply, environment deterioration, land desertification, but also has brought serious destruction to human being and natural ecosystems in the world. It is a very important subject to control and extinguish forest-fire effectively, improve the security level of forest-fire, make army officers' and soldiers' life safe. Study on the measures of emergency safety measure can be guidance for fire-fighting safely, can improve the officers' and soldiers' safety ability and reduce the number of casualty greatly.The basic data were collected from the fire information of important forest fire risk areas like Sichuan province, Great Xing 'an Mountain, and Small Xing' an Mountain, from which were picked out 168 fire cases classified into three types with great influence and serious loss from 1991-2006. These data also were investigated on the spot. In this paper, the author researched the different forest fire behaviors, computed the fire scene data on the spot with the computer simulation system, contrasted with the traditional single fire-fighting technique, analyzed the technique and relevant efficiencies in the representative significant forest fire systematically, and the summarized the compound suppression techniques and emergency safety measure scientifically and reasonably.By researching and analyzing the information, according to the characteristic of three forest fire behaviors, compound suppression technique in surface fire and emergency safety measure. The author classified the surface fire into high-speed surface fire and low-speed surface fire. High-speed surface fire develops very fast and has great fire intensity so that it's hard to approach its edge. It's usually used indirect attack to stop fire head and direct attack to extinguish fire flank and heel. When stopping the fire head, if there are natural barriers (roads, railways, rivers), the method is processing by burning next to the natural barriers; if not, using extinguishing bombing ring and man-made control line to stop the fire head. When extinguishing the fire flank, it's necessary to compose forest fire vehicle, power pump and light tools to control the fire. When extinguishing the fire heel, it's necessary to use the light tools. Extinguishing high-speed surface fire should compose the aerial technique, forest fire vehicle, power pump, extinguishing bombing ring, light tools and the emergency safety measure is that people should choose the safe place to move towards the side wind; or set the fire along the wind if time is limited; or run through the line in the weak fire place. Then the expenditure would reduce to 1/2 compared with the single suppression technique, and the number of casualty would reduce 90%. And low-speed is that people should avoid the dangerous fire scene or run out the weak fire spot facing fire.The compound technique of ground fire and emergency safety measure: ground fire is burning in roots and the duff layer, and the suppression principle is to isolate the fuel and spoiling the burning circle. Compound suppression technique composed of bulldozer, forest fire vehicle should be used; if there are covered with viscosity fuel place, the better way is to use extinguishing bombing ring. Emergency safety measure is to burn a close control line and stop the fire spreading. The forbidden thing is to get into the burning area, which had people burned and crashed.The crown fire and emergency safety measure: crown fire is classified into successive crown fire and intermittent crown fire. The fuel is distributed successively in successive crown fire. And it's easy to form spot fire, when the wind is strong. For the fire intensity is great, firefighters can't approach the burning edge. This type of fire is dangerous when wind direction is changeable. Thus compound suppression techniques consisted with aerial extinguishment, extinguishing bombing ring, forest fire vehicle, power pump and hand tools are the best method for extinguishing the fire efficiently. Fire fighters are quickly descent to look for natural barriers by parachute or descent rope from helicopter, and extinguish fire by control line. Forest fire vehicle, water pump, heli-bucketing are applied to extinguish the fire when the fire scene is close to water source and there is no natural barriers ahead of the fire scene. 50m width of control line should be set by fire fighters or by forest extinguishing bombing ring, and then sprayed fire extinguishing chemicals to the barriers when without water source and natural barriers. The methods of emergency safety measure for the type of fire are to set safety area when fire intensity rages or there are spot fires. By using the compound suppression technique and emergency safety measure, the suppression expenditure reduces to 40%, the number of casualty reduces to 20%. For the fuel are distributed uncontinously in the burning process, the surface fire and the crown fire happen alternatively in the intermittent crown fire. In this case, setting the surface fire or when crown fire turns to surface face, it's also using the surface suppression technique. The ways of intermittent crown fire urgent avoid danger is take the combustible character of uncontinous distribution , lie in advantaged terrain or rush to fire line in weak surface fire. For the objective reason, the author studied the common character problem of three forest fires suppression. It's limited that the author didn't work out the countermeasure on the vegetation feature, fuel load and combustibility. And this limitation also points out the further research direction.The research result showed that, according to the fire behavior character, take forest fire fighting synthetic extinguishment technology can offset the shortage of single fire fighting method, reached the aim of high effective extinguish fire ; It can improved extinguish fire technology level, achieved better effect that with computer simulated the happen and development of fire scene ,set up system model; aimed to different kinds of forest fire characters, proposed the urgently avoid danger measure, realized safety and highly effective.