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森林可燃物分类与模型研究的现状与展望 总被引:7,自引:0,他引:7
森林可燃物是森林燃烧的物质基础,是林火管理的基本依据.文中评述了森林可燃物分类、可燃物模型及其预测研究的现状,并简述了我国森林可燃物研究存在的问题与发展趋势. 相似文献
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本文通过建立林火控制指标,分析和研究影响林火控制的因素,提出了一种评价林火控制能力的方法,采用这种方法对小兴安岭伊春林区网络化前后的林火控制能力进行了实例分析与评价。一、林火控制指标目前世界各国衡量森林火灾指标有以下几个:一是森林火灾发生率(单位时间、单位面积土地上森林火灾的发生次数(次/万公顷·年);二是森林燃烧率(单位时间某地区烧掉的森林面积与该地区森林总面积之比);三是以年平均每次火灾所烧掉的森林面积作为森林火灾控制指标。这些指标不仅反映每次火灾面积大小,同时反映森林火灾次数的多少。因此,我们称其为林火控制综合指标,它可直接反映一个地区对森林火灾的控制能力。 相似文献
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论山东森林燃烧环网构建 总被引:4,自引:0,他引:4
从生态学观点出发,根据山东森林实际情况和森林防火工作特点,应用森林燃烧环网理论,提高了山东森林燃烧环网的框架结构。重点分析了可燃物类型、立地条件和天气要素在环网结构中的分布;论证和森林防火期和森林防火戒严期;探讨了区域性森林燃烧环网及综合森林防火体系等问题。采用叠加分析法,分析了《山东森林分布图》等图件,划分了环网区域。为应用环网理论,深入研究林火特点及规律,加强林火管理,建立区域性森林防火体系, 相似文献
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林火碳排放模型研究进展 总被引:1,自引:1,他引:0
林火作为干扰因子, 影响着森林演替、森林生物量和生产力以及生物地球化学循环。森林燃烧所释放的含碳温室气体对全球气候变化具有重要影响。对森林火灾释放的含碳气体进行有效估算, 可以弄清林火产生的含碳气体对全球碳循环的影响。文中介绍了2种林火碳排放模型, 即基于有效可燃物模型和火干扰下碳循环模型。通过对这2种估算方法的比较, 指出未来林火碳排放估算方法的发展趋势。 相似文献
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以2017 年8 月23 日珠海市遭受强台风“天鸽”的正面袭击后凤凰山森林可燃物调查和2017
年12 月20 日发生在凤凰山森林火灾火行为变化为基础,根据台风灾害前后森林可燃物载量的变化状况,
分析了的台风灾害后林火特点,比较了不同灭火方法对灭火效果的差异。结果表明,随着台风灾害后林
火燃烧环境的改变,导致灭火的难度增加,采取以水灭火和直升机吊桶洒水灭火,能有效扑灭可燃物大
幅度增加后的森林火灾,灭火效果较好。研究发现,台风灾害后导致的森林可燃物大量增加,影响林火
燃烧环境和林火行为,对于此类的森林火灾,应根据林火环境特征采取针对性灭火措施,从而提高灭火
效果,有效保护森林资源。 相似文献
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北方森林林火发生驱动因子及其变化趋势研究进展 总被引:1,自引:1,他引:0
北方森林作为气候变化最敏感的陆地生态系统之一,近些年来随着林区气候变暖,林火发生的数量和过火面积都呈显著的增加趋势,因此研究北方森林林火发生驱动因子及其变化趋势对维护其生态系统的稳定具有重要意义。文中主要从北方森林林火发生的主要控制因子和未来气候变暖条件下林火发生的预测方法及变化趋势进行综述。研究结果表明,林火的驱动因子既包括在大尺度上气候的作用,也包含植被、地形、可燃物和人类活动等局部尺度的影响。近几年来对气候变暖下林火状况趋势预测更倾向综合考虑气候和局部控制因子的作用。对我国而言,需要在更大的区域尺度上开展林火发生预测的研究。研究认为,北方森林林火变化趋势及预测研究的关键问题在于如何在不同空间尺度上确立林火发生的关键控制因子以及完善现有的林火预测方法。 相似文献
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森林火灾是一种突发性强、随机性高、扑救极为困难的自然灾害,在森林燃烧过程中可释放出高浓度PM2.5颗粒物。PM2.5是除直接烧伤和窒息外,对森林火灾扑救人员生命安全造成巨大威胁的重要污染物之一,也会给林区居民身心健康带来严重危害。文中结合国内外以森林火灾、计划烧除、室内模拟燃烧等为实验手段的森林燃烧研究,总结森林燃烧释放PM2.5的采样方法、成分分析、扩散研究、控制方法等研究进展,分析影响森林燃烧释放PM2.5的气象因素、可燃物特征、林火行为等因素,以期为提高森林火灾扑救效率、降低火灾扑救过程中的伤亡事故以及后续相关研究提供参考。 相似文献
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近年来,我国已逐步认识并接受森林健康经营理念,重视培育多功能、多目标、生物多样性丰富的健康森林。内蒙古大青山地区通过多年的大规模封育保护和植树造林活动,森林面积迅速增加,森林覆盖率不断提高。但是仍有相当部分存在森林生态系统稳定性差、生物多样性程度较低、森林火险等级较高、病虫害时有发生等的现象,致使现有森林的生态服务功能远远不能满足生态建设的需求。为此,在内蒙古大青山地区开展森林健康经营研究,具有重要的现实意义。 相似文献
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Forest managers use prescribed fire to reduce wildfire risk and to provide resource benefits, yet little information is available on whether prescribed fires can function as ecological surrogates for wildfire in fire-prone landscapes. Information on impacts and benefits of this management tool on stream and riparian ecosystems is particularly lacking. We used a beyond-BACI (Before, After, Control, Impact) design to investigate the effects of a prescribed fire on a stream ecosystem and compared these findings to similar data collected after wildfire. For 3 years after prescribed fire treatment, we found no detectable changes in periphyton, macroinvertebrates, amphibians, fish, and riparian and stream habitats compared to data collected over the same time period in four unburned reference streams. Based on changes in fuels, plant and litter cover, and tree scorching, this prescribed fire was typical of those being implemented in ponderosa pine forests throughout the western U.S. However, we found that the extent and severity of riparian vegetation burned was substantially lower after prescribed fire compared to nearby wildfires. The early-season prescribed fire did not mimic the riparian or in-stream ecological effects observed following a nearby wildfire, even in catchments with burn extents similar to the prescribed fire. Little information exists on the effects of long-term fire exclusion from riparian forests, but a “prescribed fire regime” of repeatedly burning upland forests while excluding fire in adjacent riparian forests may eliminate an important natural disturbance from riparian and stream habitats. 相似文献
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随着林业的发展,南方森林资源得到有效保护,其林下可燃物也不断增加,森林火灾增多;分析南方林区的特点,提出营建林火阻隔网络,将森林有效地进行分隔、保护,降低森林火灾发生的几率和受损率。 相似文献
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Elizabeth D. Reinhardt Robert E. KeaneDavid E. Calkin Jack D. Cohen 《Forest Ecology and Management》2008
Many natural resource agencies and organizations recognize the importance of fuel treatments as tools for reducing fire hazards and restoring ecosystems. However, there continues to be confusion and misconception about fuel treatments and their implementation and effects in fire-prone landscapes across the United States. This paper (1) summarizes objectives, methods, and expected outcomes of fuel treatments in forests of the Interior West, (2) highlights common misunderstandings and areas of disagreement, and (3) synthesizes relevant literature to establish a common ground for future discussion and planning. It is important to understand the strengths and limitations of fuel treatments to evaluate their potential to achieve an objective, develop sensible fire management policies, and plan for their effective use. We suggest that, while the potential of fuel treatment to reduce wildfire occurrence or enhance suppression capability is uncertain, it has an important role in mitigating negative wildfire effects, increasing ecosystem resilience and making wildfire more acceptable. 相似文献
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We simulated fuel reduction treatments on a 16,000 ha study area in Oregon, US, to examine tradeoffs between placing fuel treatments near residential structures within an urban interface, versus treating stands in the adjacent wildlands to meet forest health and ecological restoration goals. The treatment strategies were evaluated by simulating 10,000 wildfires with random ignition locations and calculating burn probabilities by 0.5 m flame length categories for each 30 m × 30 m pixel in the study area. The burn conditions for the wildfires were chosen to replicate severe fire events based on 97th percentile historic weather conditions. The burn probabilities were used to calculate wildfire risk profiles for each of the 170 residential structures within the urban interface, and to estimate the expected (probabilistic) wildfire mortality of large trees (>53.3 cm) that are a key indicator of stand restoration objectives. Expected wildfire mortality for large trees was calculated by building flame length mortality functions using the Forest Vegetation Simulator, and subsequently applying these functions to the burn probability outputs. Results suggested that treatments on a relatively minor percentage of the landscape (10%) resulted in a roughly 70% reduction in the expected wildfire loss of large trees for the restoration scenario. Treating stands near residential structures resulted in a higher expected loss of large trees, but relatively lower burn probability and flame length within structure buffers. Substantial reduction in burn probability and flame length around structures was also observed in the restoration scenario where fuel treatments were located 5–10 km distant. These findings quantify off-site fuel treatment effects that are not analyzed in previous landscape fuel management studies. The study highlights tradeoffs between ecological management objectives on wildlands and the protection of residential structures in the urban interface. We also advance the application of quantitative risk analysis to the problem of wildfire threat assessment. 相似文献
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森林防火隔离带技术的变革与优势 总被引:2,自引:0,他引:2
以消减可燃物的方式预防和阻隔森林火灾是林火管理工作的核心。传统阻隔技术向遮荫型防隔火技术的演变已成为近10余年西方多林国家林火管理工作的重要走向。从林火的特点和蔓延基本规律出发, 遮荫型防火隔离带技术通过局部消减可燃物载量和规则化可燃物分布, 显著降低其可能形成的林火强度, 使大多数火灾自行熄灭。该项技术的实施不受区域和气候条件限制; 与传统全光式防火隔离带和生物防火林带相比, 不但工作量较小, 对林分植被和生态环境的干扰也较小。该项技术实现了偶发性林火的防控、森林健康及生态维护的有机结合, 以此替代传统防火隔离带技术效益显著。针对遮荫型防隔火技术的进一步研究工作应包括不同稀化程度林带潜在火行为和其防隔火效能的量化评估、林地局部可燃物稀化的高效作业机具以及伴随该项技术实施产生的大量生物质副产品的有效利用问题。 相似文献
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澳大利亚草地火研究进展 总被引:1,自引:1,他引:0
随着全球气候变化,尤其变暖明显,干旱天气常现,草地火频繁发生,给全球生态环境带来了巨大影响。文中从草地火形成机制、火对草地生态系统的影响、草地火时空格局及规律、草地火监测预警及预测预报、草地火管理、草地火风险评估、引燃草地火的火源等方面来阐述澳大利亚草地火研究进展,总结草地火研究存在的问题,并展望草地火未来研究的方向。研究结果能为我国草地火的预防与扑救提供参考,为我国及时调整现行草地火管理政策、改进草地火防控措施以及草地火生态、可持续经营管理提供借鉴。 相似文献
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Non-industrial private forests (NIPFs) and public forests in the United States generate many non-market benefits for landholders
and society generally. These values can be both enhanced and diminished by wildfire management. This paper considers the challenges
of supporting economically efficient allocation of wildfire suppression resources in a social cost-benefit analysis framework
when non-market values are important. These challenges include substantial gaps in scientific understanding about how the
spatial and temporal provision of non-market values are affected by wildfire, the limited utility of benefit transfer in wildfire
assessment, a lack of studies that have estimated marginal willingness-to-pay to conserve non-market values, violation of
consumer budget constraints, and the infeasibility of valuing indigenous cultural heritage. These challenges present serious
impediments to adapting price-based decision-support tools to accommodate non-market values and support decision-making consistent
with contemporary federal wildfire policy. Departure from the historic range and variability of ecological conditions is proposed
as a complementary framework to support wildfire management decisions when non-market values are important on NIPF and public
forestland.
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Tyron J. VennEmail: |