北京门头沟区主要林分类型地表火行为模拟研究  

Simulation study on surface fire behavior of main forest types in Mentougou District, Beijing

作　　者：李炳怡 刘冠宏 舒立福[1] Li Bingyi;Liu Guanhong;Shu Lifu(Key Laboratory of Forest Protection of National Forestry and Grassland Administration,Research Institute of Forest Ecology,Environment and Protection,Chinese Academy of Forestry,Beijing 100091,China;School of Ecology and Nature Reserves,Beijing Forestry University,Beijing 100083,China)

机构地区：[1]中国林业科学研究院森林生态环境与保护研究所,国家林业和草原局森林保护学重点实验室,北京100091 [2]北京林业大学生态与自然保护学院,北京100083

出　　处：《北京林业大学学报》2022年第6期96-105,共10页Journal of Beijing Forestry University

基　　金：国家自然科学基金面上项目(31770696)。

摘　　要：【目的】地表火是最常见的林火类型,直接影响植被更新和生态系统的养分配置与循环。反映林火行为的常见指标有火蔓延速度、单位面积发热量、火强度和火焰高度。根据实际林分和立地条件进行火行为模拟,可以揭示林火发生条件,并有效判断树冠火发生的可能性,为林火的预防和扑救决策工作提供科学依据。【方法】选取北京市门头沟典型林分(刺槐林、油松林、侧柏林)为调查对象,每个林分设置5块样地,共计15块样地。通过野外调查获取可燃物载量(灌木可燃物、草本可燃物、1时滞可燃物、10时滞可燃物、100时滞可燃物)、林分因子(第一活枝下高、第一死枝下高、树高、胸径、郁闭度)和立地因子(海拔、坡度、坡向、坡位)数据,使用BehavePlus6软件,基于气象参数和可燃物参数,模拟不同燃烧条件下不同林分类型的火行为指标,分别为地表火蔓延速度、单位面积发热量、火线强度和火焰长度;使用R语言进行主成分分析,根据贡献率探讨林分因子、立地因子和可燃物因子对火行为的潜在影响。【结果】侧柏林、刺槐林和油松林的可燃物总载量分别为15.35、17.59、15.28 t/hm^(2),其中易燃可燃物载量(即上层枯叶、易燃草本、1时滞可燃物)分别是4.55、4.41、6.18 t/hm^(2),分别占林分总可燃物载量的29.6%、25.1%、40.4%。防火期内门头沟区的平均风速为2.2 m/s(7.9 km/h),地表火蔓延速度油松林>侧柏林>刺槐林,速度分别达11.5、11.1、8.0 m/min。单位面积发热量油松林>侧柏林>刺槐林,分别为23 091、21 155、18 413 kJ/m;火强度油松林>侧柏林>刺槐林,分别为4 426、3 882、2 468kW/m;油松林火焰高度变化范围分别是0.89~3.40 m、1.34~2.91 m、1.78~3.88 m,同等条件下火焰高度油松林>侧柏林>刺槐林;8级大风天气下(风速17.9 m/s,64.4 km/h),地表火行为的模拟结果会略有改变,侧柏林的火蔓延速度更快、火强度[Objective] Surface fire is the most common type of forest fire, which directly affects vegetation regeneration and nutrient allocation and circulation of ecosystem. The common indexes reflecting forest fire behavior are fire spreading speed, calorific value per unit area, fire intensity and flame height. The fire behavior simulation based on the actual stand and site conditions can reveal the conditions of forest fire occurrence, effectively judge the possibility of crown fire occurrence, and provide a scientific basis for forest fire prevention and firefighting decision-making. [Method] Typical forest stands(Robinia pseudoacacia forest, Pinus tabuliformis forest and Platycladus orientalis forest) in Mentougou District of Beijing were selected as the survey objects. 5 sample plots were set for each stand, a total of 15 sample plots. Through field investigation, the data of fuel load(shrub fuel, herb fuel, 1 h fuel load, 10 h fuel load, 100 h fuel load),stand factors(height of the first living branch, height under dead branches, tree height, DBH, canopy density) and site factors(altitude, slope gradient, slope aspect, slope position) were obtained. The BehavePlus6 software was used to simulate the fire behavior indicators of different stand types under varied fuel conditions based on meteorological parameters and fuel parameters, they are the spreading speed of surface fire, the calorific value per unit area, the intensity of fire line and the length of flame. Principal component analysis was conducted with R language, and the potential effects of stand factors, site factors and fuel factors on fire behavior were discussed according to the contribution rate. [Result] The total fuel loads of Platycladus orientalis forest(POF), Robinia pseudoacacia forest(RPF) and Pinus tabuliformis forest(PTF) were respectively 15.35, 17.59, 15.28 t/ha, in which, the inflammable fuel loads(up-layer leaf,flammable herb, 1 h fuel) were respectively 4.55, 4.41, and 6.18 t/ha, accounting for 29.6%, 25.1% and 40.4% of the total fuel lo

关 键 词：可燃物载量 细小可燃物 地表火行为 火强度 Rothermel地表火蔓延模型 

分 类 号：S762.3[农业科学—森林保护学]