Schima superba is widely used for shaded fuelbreaks in southern China. Experiments were done in the laboratory and wild for testing the effects of the shaded fuelbreaks. The cone calorimeter test results indicated tha...Schima superba is widely used for shaded fuelbreaks in southern China. Experiments were done in the laboratory and wild for testing the effects of the shaded fuelbreaks. The cone calorimeter test results indicated that China red pine (Pinus massoniana) needles are easy to burn under the condition of the incident radiant flux at 75 kW/m^2 and ignition source, the peak value of heat release rate of pine needles appears earlier (22 s) and higher (146 kW/m^2). S. superba leaves burnt slowly and had a lower total heat release. The mass loss curves present that the peak value of pine needle is higher than that of S.superba leaves, which is 0.14 g/s versus S.superba 0.08 g/s. A fire experiment has been done in a suburb of Guangzhou City. It was measured that the fuel loads and their distribution of the stand of pine and fuelbreak before and after the fire experiment. There was almost no grass and litter on the ground of the fuelbreak due to clearing litter every year at the beginning of fire season. In the pine forest, there were shrubs, grasses and litter under the story.During the burning experiment, most of the pine forest has swept by surface fire at a spread speed of 2.2 m/min and fire intensity of 168-2961 kW/m. But in some area along the outside fire line, there occurred crown fire due to the high fuel load on the ground. The flame got 8.0-8.5 m high and fire intensity 24 881～28 379 kW/m. Part crown of several trees of the fuelbreak burnt because the crown fire spread. But the fire had not across the fuelbreak and no spotting fire happened. The fire experiment results indicated that the fuelbreak has effects on mitigating fire intensity and depress fire spread in some degree. The shaded fuelbreak has the ability of fire resistance and its dense crown can block spotting fire resources.展开更多
文摘Schima superba is widely used for shaded fuelbreaks in southern China. Experiments were done in the laboratory and wild for testing the effects of the shaded fuelbreaks. The cone calorimeter test results indicated that China red pine (Pinus massoniana) needles are easy to burn under the condition of the incident radiant flux at 75 kW/m^2 and ignition source, the peak value of heat release rate of pine needles appears earlier (22 s) and higher (146 kW/m^2). S. superba leaves burnt slowly and had a lower total heat release. The mass loss curves present that the peak value of pine needle is higher than that of S.superba leaves, which is 0.14 g/s versus S.superba 0.08 g/s. A fire experiment has been done in a suburb of Guangzhou City. It was measured that the fuel loads and their distribution of the stand of pine and fuelbreak before and after the fire experiment. There was almost no grass and litter on the ground of the fuelbreak due to clearing litter every year at the beginning of fire season. In the pine forest, there were shrubs, grasses and litter under the story.During the burning experiment, most of the pine forest has swept by surface fire at a spread speed of 2.2 m/min and fire intensity of 168-2961 kW/m. But in some area along the outside fire line, there occurred crown fire due to the high fuel load on the ground. The flame got 8.0-8.5 m high and fire intensity 24 881～28 379 kW/m. Part crown of several trees of the fuelbreak burnt because the crown fire spread. But the fire had not across the fuelbreak and no spotting fire happened. The fire experiment results indicated that the fuelbreak has effects on mitigating fire intensity and depress fire spread in some degree. The shaded fuelbreak has the ability of fire resistance and its dense crown can block spotting fire resources.
