北京地区林木可燃性研究

利用GIS空间分析技术和知识发现技术研究了北京房山地区林木可燃性.通过将历史林火数据进行去噪处理、分类处理,建立房山林火数据库;用知识发现算法和GIS空间分析方法,研究不同林木的可燃性,并用传统方法获取了林分生物量.实验表明,林分的生物量与林木可燃性并无必然的联系,林分的燃烧是一种复杂现象,受到社会、经济等因素的影响.该结论对林火研究及林火应用管理具有一定的指导作用.     

The flammability of shrubs and trees in anAcacia mangium plantation based on silica-free ash content

Preliminary research to understand the flammability of 14 species of shrubs and 8 species of trees based on silica-free ash content was done in order to recognize which shrubs or trees are more flammable. The results show that the silica-free ash content of shrubs and trees leaves was greater than the stems ranging between 1.7% and 11.4% for leaf and 0.4% and 7.8% for the stems. The shrubsDicranopteris linearis, Imperata cylindrica, Eupatorium pubescens, Lantana camara, Eugenia sp.,Cliforia laurifolia, Pterospermum sp.,Hibiscus similis, Clidemia hirta andTrema orientalis must be considered when fire invades the plantation as well as the treeParaserianthes falcataria, Eucalyptus urophylla, Calliandra callothyrsus, andPeronema canescens.     

阻燃处理竹篾层积材的性能分析

采用M1和M2两种阻燃剂,通过冷热槽法,浸渍处理竹篾后制备竹篾层积材,测定其氧指数、热释放速率、发烟总量等燃烧性能,以及静曲强度、弹性模量等物理力学性能.结果表明:经2种阻燃剂处理,竹篾层积材的耐火性能大幅提高,尤其是M2处理的层积材,综合燃烧性能好;虽板材的力学性能都有一定程度的下降,但仍能满足LY/T 1072-2002的要求.     

Southeast Tibet Forest Fuel Types and Flammability

Southeast Tibet forest is in east subtropical zone. This region natural environment is unique, influenced by the southwest monsoon, so forest fires are very easy to occur in the dry season. Forest in this region is over mature forest, and accounts for much proportion. Fire season in this area is winter and spring. But in the special year, forest fires can also occur in the hot summer. Fire season lasts from October to next February,but to April in an individual arid year. Most of the fires in this area are surface fires, crown fire, can occur after long time drought. Ground fires do not occur in the region.     

应用卫星遥感技术监测林火燃料可燃性研究现状与发展趋势

遥感可以提供燃料和其可燃性空间分布的信息,准确地了解燃料属性的时空动态,特别是空间分辨率高、覆盖范围大的燃料类型和燃料可燃性的遥感图像可以大大提高火险预报精度并有效地采取措施控制火燃烧的行为。本文通过文献综述,分析了应用卫星遥感技术监测林火燃料可燃性的国内外进展和未来发展趋势。     

Effects of vegetation type and fire regime on flammability of undisturbed litter in Southeastern France

To assess the effect of vegetation types and of fire regime on the flammability of dead fuels, samples of litter were collected undisturbed (i.e. keeping the structure of litter layers) in 29 study sites spread over the limestone-derived soils of Provence. The sampling plan comprised the most representative ecosystems of the study area: pure Pinus halepensis stands, mixed pine-oak stands and shrublands. Three classes of litter depth were studied (low, medium and high) to account for the variability existing in the field. Sampling also included the number of fires in each site since 1960 (no fire, 1 or 2 fires and ≥3 fires) and the time interval since the last fire (≤15 years, 15-45 years and >45 years). Flammability experiments were carried out in laboratory using a glowing firebrand and a 10 km h⁻¹ wind. The main variables recorded were: ignition frequency, time-to-ignition, flaming duration, flame rate of spread, flame propagation, mean flame temperature, maximum flame height and rate of consumption.Results showed that the ignition frequency was higher in mixed stands than in pure pine stands whereas the time-to ignition, flaming duration and rate of consumption were the highest in pure pine stands. The maximum flame height and the flame propagation decreased with the increase of the number of fires and the time-to-ignition was the highest when the interval since the last fire was the shortest. Increases in litter depth resulted in increased mean flame temperature, maximum flame height and flame propagation. These results can be explained, in part, by the proportions of the different litter components.     

我国人工林森林可燃物特点及管理技术研究进展

在全球变暖背景下森林火灾发生的危险性持续增加,可燃物是唯一可人为调控的火环境因子。与天然林相比,人工林结构简单,且以富含油脂的纯林为主,同时多为中幼龄林,易发生森林火灾。文中从人工林可燃物特点及其与林火引燃和火行为的角度出发,综述了人工林可燃物管理技术,对管理中存在的问题进行了分析,建议今后人工林可燃物管理在降低森林易燃性和燃烧性的同时,还须充分考虑管理技术对生态系统和林木生长的影响,优先选择对生态环境友好且促进林木生长的技术和措施。     

北京地区主要树种理化性质研究及易燃性初步分析

森林燃烧所释放的热量、火种类、火行为等各种林火属性与树种易燃性密切相关,而树种的理化性质在一定程度上制约着易燃性,因此对树种理化性质和易燃性的研究是必要的。基于20种树种的实验分析,确定了可燃物热值、抽提物含量、灰分含量、含水量、密度的相关性,并建立相应的回归模型;基于树种理化性质的分析,比较了20种树种的易燃性,进行排序并划分等级。     

Flammability Properties of Composites of Wood Fiber and Recycled Plastic

Flammability properties of composites of wood fiber and recycled plastic were evaluated by the cone calorimeter and oxygen index chamber. Results were shown as follows: 1) Wood-PVC composite showed worse thermal stability on time to ignition (TTI) and mean heat release rate (MHRR), but better performance on heat release rate (HRR) and mean efficient heat of combustion (MEHC); wood-PP composite had better thermal stability properties, but was worse on other fire performance; 2) Compared with wood-PVC composi...     

Properties and flammability of major tree species in the Beijing area

In order to examine correlations among the properties of tree species and to quantify the relationships between these properties and flammability, the properties of 20 tree species, consisting of heat of combustion, extractive contents, ash content, moisture content and basic density, were measured via experimental methods. In the first instance, the results show that, there are significant correlations between heat of combustion and extractive contents, ash content and basic density. Second, heat of combustion can be presented effectively in terms of linear regression models with extractive contents and ash content as independent variables. Third, a flammable model was developed based on four properties of tree species as independent variables, i.e., heat of combustion, extractive contents, ash content and moisture content. Finally, the flammability of 20 tree species is compared, ordered and ranked based on this flammable model. The conclusion is that flammability can be predicted from properties of tree species, which are significantly correlated among themselves. __________ Translated from Forest Resources Management, 2008, 4: 83–88 [译自:林业资源管理]