华南地区森林地表可燃物火蔓延速度特性的实验研究

Experimental study on fire spread rate characteristics of forest surface fuels in South China

华南地区植被丰富,人类活动频繁,一旦发生森林火灾,后果严重。为探究华南地区森林地表可燃物种类和燃料床特性对火蔓延速度的影响规律,给扑救森林火灾提供参考数据,通过实地采样与室内燃料床火蔓延速度测量实验,定量分析了森林地表可燃物火蔓延速度特性。实验结果表明,桉树叶燃料床在5种燃料床中蔓延速度最快,加上其在该地区的种植情况,具有较高的火灾危险性。得到了桉树叶燃料床特性对火蔓延速度影响的规律,发现含水率开始增加阶段,蔓延速度衰减很少,含水率超过14%后,蔓延速度快速衰减,到18%后蔓延速度衰减再次减少;蔓延速度与厚度成幂函数关系,厚度增加使蔓延速度增加;堆积密度、宽度对火蔓延速度影响不大。

South China is rich in vegetation and the human activities are frequent. Once the forest fires occur, the consequences are serious. In order to explore the influence law of forest surface fuel kinds and fuel bed characteristics on fire spread rate in South China and provide reference data for forest fire fighting,the paper quantitatively analyzed the fire spread rate characteristics of forest surface fuels through field sampling and indoor fuel bed fire spread rate measurement experiments. The experimental results showed that the spread rate of Eucalyptus robusta Smith leaf bed was the largest among the five fuel beds. Combined with its planting in this region, it had a high fire risk. The influence law of Eucalyptus robusta Smith leaf bed characteristics on the fire spread rate was obtained. It was found that in the stage when the moisture content began to increase, the spread rate decreased slightly. When the moisture content exceeded14%, the spread rate decreased rapidly, and then the spread rate decreased slightly again when the moisture content reached18%;The spread rate was a power function of thickness, and the increase of thickness would contribute to the increase of the spread rate;The bulk density and width had little effect on the fire spread rate.