Study On Forest Fuel And Forest Fire Danger Rating Predication

In this paper,the auther viewed the research status quo and developing tendency of forest fuel and forest fire danger predication.By the means of quality and quantity ,the forest fuel and fire danger rating in Qilian Mountains were researched.The 22 forest farms were zoned according to the fire danger in Qilian Mountains. 1.According to the measurement of present quantity of withered things of Picea crassifolia, Sabina przewalskii , shrub and grassland, the quantity of combustible fuel and the time of maximum fuel quantity were obtained .The present combustible fuel quantity in Picea crassifolia was 39.566t/hm2, 6.899 t/hm2 in Sabina przewalskii, 20.223t/hm2 in shrub and 3.725t/hm2 in grassland.The total combustible fuel quantity in Qilian Mountains was 2147.4t.The quantity will be maximum in March when the forest fire was easy to occur. 2.According to the measurement of quantity of withered things monthly in 4 forest ,the annual quantity of withered things were obtained .The annual quantity of withered things in Picea crassifolia was 3.507 t/hm2, 3.676 t/hm2 in Sabina przewalskii, 0.8492 t/hm2 in shrub .The maximum component of withered things was leaves which were combustible . 3.According to the measurement of dead and dynamic fuel moistures of different fuel type, the changing patterns of fuel moistures were obtained. The fuel moistures were influenced by bioecological characteristics, physical and chemical characterictics and meterological factors. The moistures of different plant and different growth periods were different. Dynamic fuel moisture was mainly determinded by their physiological factors. The moistures of Picea crassifolia branches and leaves were higher than Sabina przewalskii and shrub, the grassland's was lowest . The dead fuel moistures were determinded by meterological factors.The lowest period of dead fuel moisture occurred from January to April. The highest period occurred from May to September . 4.According to the measurement of dead fuel moistures and meterological factors in field, by the means of multi-factors statistics, the models of dead fuel moisture were developed. The fitting effect of the models were satisfactory and the differences between the predication and the measurement was small, so the model can be used to predicate the fuel moisture. 5.Based on the field ignition experiment, the initial ignition moisture of different fuel type was obtained . 6.Five fire danger ratings of fuel types were classified on the basis of initial ignition moisture.With meterological factors and developed moisture models, the fuel moistures could be predicated and the fire danger rating could be predicated . 7.Based on the theory of forest burning circle ,fire danger factors were found and the principle of fire danger zoning was made, the 22 forest farms were zoned into 3 regions expressing different fire danger ratings .The first region was high fire danger region including 11 forest farms ,they were Sidalong, Dongdashan, Longshoushan, Qifeng, Longchanghe, Kangle, Xishui, Mati, Xiyinghe, Dahekou, Junmachang, amounting for 50%., the fire danger is high. The second region was middle fire danger region including 7 forest farms, they were Dahuangshan, Dongdahe, Shibalipu, Qilian, Changlingshan, Hualong, Gucheng, amounting for 31%; The third region was low fire danger region including 4 forest farm,they were Shangfangsi, Haxi, Wushaoling, Xiama.the fire danger in this region was lowest. The result of zoning was similar with the pattern of forest distribution and forest management expressing the characters and patterns of forest fire . 8.The map of forest fire danger was drawed. It can be served as fire danger predication and supplying an excellent fire saving scheme.