山火引发输电线路跳闸事故的统计与分析

通过对部分引发输电线路跳闸的火灾事故进行统计以及对典型火烧迹地的跳闸事故进行考察,分析山火发生的次数、跳闸率、地理位置、过火区域地形地貌等,探讨引发线路跳闸的潜在山火类型、形成过程、影响因素和特性参数以及跳闸输电线路的放电特性参数。结果表明:易引发跳闸的山火类型依次为中高速中高强度的地表火、树冠火、冲冠火和地表火转化的树冠火;火灾基本为上山火,易形成高火焰、高热量、高温度、高浓度(烟尘粒子和带电质点)的易导致线路跳闸的环境条件;发生跳闸时输电线路主要放电部位为子导线,放电方式依次为对树、相间和对地;在中高强度火灾条件下放电距离突破了输电线路正常运行所需安全间隙,产生流注而发生跳闸。     

大范围电网山火灾害“星地空”立体防控体系建设及应用

山火是危及电网安全运行的严重灾害。电网发生山火时,处置时限性要求极高,为提升电网山火的处置效率,构建“预测提前部署—卫星广域、空中机载巡查及时发现—空地联动灭火”的山火立体防治体系：研制直升机监测、通讯和灭火一体化装置,实现直升机监测、应急会商与灭火快速联动,携带直升机灭火装备巡查山火,发现山火快速灭火。实践中,该体系已扑灭现场危及电网安全运行的山火80余处,应用表明：直升机灭火装备40 min内灭火距离达100 km。     

A Prevalence Study Of The Sick Building Syndrome (SBS) And Facial Skin Symptoms In Office Workers

The prevalence of symptoms compatible with the Sick Building Syndrome (SBS) was measured in a questionnaire study among 4 943 office workers. An assessment of the relation between SBS symptoms and personal, physical and psychosocial exposure factors was made. In contrast to males, the majority of females were lower-grade staff Females reported annoyance from physical climate factors more often, both at work and at home. Males reported a better psychosocial situation than females. Female gender, asthmalrhinitis, paper and VDT work were related to an increased prevalence of SBS symptoms. The prevalence of facial skin symptoms increased markedly with the amount of VDT work. Psychosocial workload intensifid this relation. Inequalities in physical climate and psychosocial conditions associated with different positions held in the offices can be of importance for the increased occurrence of symptoms among females.     

Householders’ safety-related decisions,plans, actions and outcomes during the 7 February 2009 Victorian (Australia) wildfires

This study examined decisions made by householders under wildfire threat. Data were obtained from interviews with survivors of severe wildfires in Victoria (Australia) on 7 February 2009 which killed 172 civilians and destroyed more than 2000 homes. Prior to this, Australian fire agency community wildfire safety policy was that residents should: ‘Prepare, stay and defend or leave early’. Most of the 223 interviewees who stayed and defended did so because this was their wildfire safety plan, and they believed that they would be successful despite the predicted extreme fire danger weather. In 79% of cases, defence was successful; for the remaining 21% the house was destroyed and several lives were imperilled. Of the 216 who left for a safer location only 39% said that this was their wildfire safety plan; for most, the action of leaving was triggered by realisation of the imminent threat posed by the fire; 36% self-evacuated under hazardous conditions. The findings suggest that community wildfire safety programs should emphasize: (a) the risks associated with staying to defend a property; and (b) how householders should prepare in order to leave safely if a fire threatens.     

Indoor air pollution from biomass combustion and respiratory symptoms of women and children in a Zimbabwean village

Rural areas of developing countries are particularly reliant on biomass for cooking and heating. Women and children in these areas are often exposed to high levels of pollutants from biomass combustion that is associated with a range of respiratory symptoms. Domestic exposure to carbon monoxide (CO) and respirable particles (RSPs) in association with respiratory symptoms among women and children in Zimbabwe was investigated in 48 households. Health status and household characteristics were also recorded. In this study, indoor levels of CO and RSPs exceeded World Health Organization (WHO) air quality guidelines in over 95% of kitchens. The level of indoor air pollutants was associated with the area of kitchen windows and the length of cooking time combined with the level of fire combustion. Prevalence of respiratory symptoms was 94% for women and 77% for children. In addition, women reporting respiratory symptoms were exposed to higher levels of RSPs when compared with those reporting no respiratory symptoms. The study results indicated that levels of indoor air pollutants in rural Zimbabwe may contribute to respiratory symptoms in both women and children. PRACTICAL IMPLICATIONS: Levels of respirable particles and carbon monoxide in kitchens in rural Zimbabwe are unacceptably high and measures to reduce levels should be undertaken. Based on the study findings, recommendations for increasing the area of kitchen windows may be considered as a practical method of reducing indoor air pollutants in rural Zimbabwe.     

Mercury distribution in two Sierran forest and one desert sagebrush steppe ecosystems and the effects of fire

Mercury (Hg) concentration, reservoir mass, and Hg reservoir size were determined for vegetation components, litter, and mineral soil for two Sierran forest sites and one desert sagebrush steppe site. Mercury was found to be held primarily in the mineral soil (maximum depth of 60 to 100 cm), which contained more than 90% of the total ecosystem reservoir. However, Hg in foliage, bark, and litter plays a more dominant role in Hg cycling than the mineral soil. Mercury partitioning into ecosystem components at the Sierran forest sites was similar to that observed for other US forest sites. Vegetation and litter Hg reservoirs were significantly smaller in the sagebrush steppe system because of lower biomass. Data collected from these ecosystems after wildfire and prescribed burns showed a significant decrease in the Hg pool from certain reservoirs. No loss from mineral soil was observed for the study areas but data from fire severity points suggested that Hg in the upper few millimeters of surface soil may be volatilized due to exposure to elevated temperatures. Comparison of data from burned and unburned plots suggested that the only significant source of atmospheric Hg from the prescribed burn was combustion of litter. Differences in unburned versus burned Hg reservoirs at the forest wildfire site demonstrated that drastic reduction in the litter and above ground live biomass Hg reservoirs after burning had occurred. Sagebrush and litter were absent in the burned plots after a wildfire suggesting that both reservoirs were released during the fire. Mercury emissions due to fire from the forest prescribed burn, forest wildfire, and sagebrush steppe wildfire sites were roughly estimated at 2.0 to 5.1, 2.2 to 4.9, and 0.36+/-0.13 g ha(-1), respectively, with litter and vegetation being the most important sources.     

Computer vision for wildfire research: An evolving image dataset for processing and analysis

The last decade has witnessed the use of computer vision for wildfire detection and measurement. The first and most important step for computer vision analysis is the fire pixel detection because it determines the accuracy of the following processing. The evaluation and the comparison of the wildfire detection algorithms of the literature and the development of new ones needs open datasets with a large number of annotated images and their ground truth. We address this issue by presenting a publicly evolving wildfire annotated image database with ground truth data with examples of use. Currently, it contains 500 visible images and, in a more limited number, multimodal images and videos with frame by frame annotations. This is currently the largest dataset released in this research field.     

Planning and Planning Education under Conditions of Globalization

The flow of amenity-based migrants to fire-prone areas of the US Rocky Mountain West has brought increasing attention to wildfire hazard mitigation management. This paper attempts to build agent-based models which link natural amenity driven exurban growth to wildfire mitigation regimes to provide a framework for assessing cumulative effects of hazard mitigation policy under alternative policy structures. Three simulations were built to demonstrate how agent-based models (ABM) can be used to examine and compare people's choices of residential location in response to natural amenities and wildfire policies. This paper investigates the ways in which policy effects are incorporated dynamically into the land development decision-making process at an individual level in a case study area. Our results show that individual location choices with respect to wildfire risk are sensitive to wildfire mitigation policies.     

Human symptom responses to bioeffluents,short‐chain carbonyls/acids,and long‐chain carbonyls in a simulated aircraft cabin environment

Occupants of aircraft have reported an array of symptoms related to general discomfort and irritation. Volatile organic compounds (VOCs) have been suggested to contribute to the reported symptoms. VOCs are from products used, bioeffluents from people and oxidation reaction products. Thirty‐six healthy, young female subjects rated symptoms and environmental quality during an eight‐hour exposure to groups of compounds often present in aircraft: (i) long‐chain carbonyls, (ii) simulated bioeffluents, and (iii) short‐chain carbonyls/organic acids. Statistically more symptoms were identified for the simulated bioeffluents and, to a lesser extent, short‐chain carbonyls/organic acids compared to a control condition, although they remained in the acceptable range. There were three temporal patterns in the environmental quality and symptom reports: (i) an adaptive response (immediate increases followed by a decline); (ii) an apparent physiological effect (increases one to three hours into the exposure that remained elevated); and (iii) no statistical differences in reported environmental quality or symptom severity compared to the control air conditions. Typical concentrations found in aircraft can cause transitory symptoms in healthy individuals questioning the adequacy of current standards. Understanding the effects on individuals sensitive to air pollutants and methods to remove the compounds causing the greatest symptom responses are needed.     

The Status Of Lone And Partnered Women Seeking State Housing Assistance In Two New Zealand Cities

Women householders living alone or with children have been identified as one of a number of marginalised groups within the housing markets of Western cities. An extensive literature suggests that many such women are likely to experience discrimination, poverty and inadequate housing. In this paper we review the status of lone women parents in New Zealand housing policy as a prelude to reporting on the housing experiences of a sample of applicants seeking state housing assistance in Auckland and Christchurch. The samples, drawn from the waiting lists of the (former) Housing Corporation of New Zealand (1989-90), included both women with partners (n=50) and women living alone or with children (n=119). The lone women were slightly poorer, they had less access to private transport, and they reported higher levels of residential mobility. However, these women reported that the physical condition of their housing was significantly better, and characteristics of the neighbourhood such as safety and proximity to friends were more important influences on their housing satisfaction than for partnered women. We conclude that lone women appear to make more demands on their neighbourhood, and more often seek housing assistance from the state for reasons of refuge than is the case for partnered women.     

A comparison between occupants’ and inspectors’ reports on home dampness and their association with the health of children: The ALLHOME study

There is some discussion concerning the methodology to be used in order to obtain health-relevant information regarding moisture-related problems in homes (dampness). Occupants’ reports, inspectors’ observations and physical measurements are often used methods. In the current study, data on dwelling dampness and characteristics as reported by parents of 216 pre-school children (the cross-sectional questionnaire study ALLHOME-1) was compared with the information collected by non-professional dwelling inspectors in a nested case–control study (the ALLHOME-2 study). The study took place in the cities of Burgas and Sofia in Bulgaria. The inspectors reported less visible mould, but more damp stains and a mouldy odour than the parents. Exposure to dampness, as reported by parents, was significantly associated with airways, nose and/or skin symptoms (case status) among children, while no association was found between inspectors’ observations on dampness and children's health. Parental reports on housing characteristics such as type of house, residential situation, and type of flooring material matched with those identified by the inspectors and therefore can be used as a reliable source of information in studies on indoor environmental exposure and health. With regard to dampness, parental reports seem to be more health relevant than inspectors reports.     

Wildland fire spot ignition by sparks and firebrands

Wildland and Wildland Urban Interface (WUI) fires are an important problem in many areas of the world and may have major consequences in terms of safety, air quality, and damage to buildings, infrastructure, and the ecosystem. It is expected that with climate changes the wildland fire and WUI fire problem will only intensify. The spot fire ignition of a wildland fire by hot (solid, molten or burning) metal fragments/sparks and firebrands (flaming or glowing embers) is an important fire ignition pathway by which wildfires, WUI fires, and fires in industrial settings are started and may propagate. There are numerous cases reported of wildfires started by hot metal particles from clashing power-lines, or generated by machines, grinding and welding. Once the wildfire or structural fire has been ignited and grows, it can spread rapidly through ember spotting, where pieces of burning material (e.g. branches, bark, building materials, etc.) are lofted by the plume of the fire and then transported forward by the wind landing where they can start spot fires downwind. The spot fire problem can be separated in several individual processes: the generation of the particles (metal or firebrand) and their thermochemical state; their flight by plume lofting and wind drag and the particle thermo-chemical change during the flight; the onset of ignition (smoldering or flaming) of the fuel after the particle lands on the fuel; and finally, the sustained ignition and burning of the combustible material. Here an attempt has been made to summarize the state of the art of the wildfire spotting problem by describing the distinct individual processes involved in the problem and by discussing their know-how status. Emphasis is given to those areas that the author is more familiar with, due to his work on the subject. By characterizing these distinct individual processes, it is possible to attain the required information to develop predictive, physics-base wildfire spotting models. Such spotting models, together with topographical maps and wind models, could be added to existing flame spread models to improve the predictive capabilities of landscape-scale wildland fire spread models. These enhanced wildland fire spread models would provide land managers and government agencies with better tools to prescribe preventive measures and fuels treatments before a fire, and allocate suppression resources and issue evacuation orders during a fire.     

How much does Environmental Tobacco Smoke Contribute to the Building Symptom Index?

Environmental tobacco smoke (ETS) has been identified as one of the factors associated with the symptoms of the sick building syndrome (SBS). We investigated the role of ETS in an office building during the phased introduction of a smoking ban. Over a two-year period we measured symptoms using a validated questionnaire, environmental nicotine levels and salivary cotinine as a biological marker of nicotine absorption in a stratified systemic sample of 375 office employees (91% response rate). In addition, 26 persons from a non-smoking office were studied as a control group. This report describes the findings derived from a cross-sectional analysis of the initial baseline data. Amongst the validated nonsmokers, symptoms increased with increasing nicotine exposure from ETS (r= 0.165 p < 0. 01), supporting the role of ETS in the SBS. Smokers reported significantly fewer symptoms than non-smokers, as has been found before, but were exposed to higher levels of airborne nicotine as expected. We suggest that this factor, along with the misclassification of smoking status, may have obscured an association between ETS exposure and the SBS in previous studies. An analysis of the findings after implementation of the smoking ban should provide further information on how much of the SBS is attributable to ETS in this study population.     

Symptoms and Perceived Indoor Air Quality among Occupants of Houses and Apartments with Different Ventilation Systems

The purpose of the study was to evaluate the occurrence of symptoms and the perception of poor indoor air quality among the occupants of houses and apartments with different ventilation systems. The study population consisted of the 473 occupants of 242 dwellings in the Helsinki metropolitan area who responded to a self-administered questionnaire (response rate 93.1%) after a two-week period of indoor air quality measurements. The symptoms of interest were those often related to poor indoor air quality including dryness or itching of the skin; dryness, irritation or itching of the eyes; nasal congestion (“blocked nose”) nasal dry-ness; nasal discharge (“runny nose”); sneezing; cough; breathlessness; headache or migraine; and lethargy, weakness or nausea. Perception of coldness; warm-ness; draught; dryness; stuffiness; and sufficiency of air exchange was also requested. The age-standardized period prevalences of the symptoms and complaints were systematically more common among the occupants of the apartments than those of the houses. The occupants of the houses with natural ventilation seemed to have more symptoms and complaints than those with balanced ventilation. However, in the apartments with balanced ventilation the occupants reported, in general, more symptoms and complaints than those with natural ventilation.     

输电线路山火无人机监测与灭火技术研究

应用无人机搭载三维激光,识别输电线路、杆塔及下方植被,进行山火风险评估。无人机搭载YCbCr颜色空间检测分析模块进行山火识别。提出了无人机弹道发射、投掷灭火球以及小流量防蒸发喷射等输电线路初发山火的灭火方法,可快速扑灭初发山火。     

江西省洪涝灾害后灾民心理健康状况的调查

目的了解江西省洪涝灾害后灾民的心理健康状况,探讨其发生和发展规律,并对重点人群进行心理干预。方法采用分层整群抽样方法,同时对江西省2010年洪涝灾害后1周4 666名18~69岁的灾民采用症状自评量表（SCL-90）和事件影响量表（IES-R）进行心理健康测评。结果 4 666名灾民中有腰痛者2 363人,占50.6%;忘记性大者2 169人,占46.5%;容易烦恼和激动者1 913人,占41.0%;头痛者1 672人,占35.8%;醒得太早者1 573人,占33.7%。江西北部地区灾民躯体化、焦虑、恐怖评分值均明显低于江西中部、江西南部地区（均P〈0.01）,江西中部地区灾民强迫评分值明显低于江西北部、江西南部地区（P〈0.05）。男性躯体化、焦虑、恐怖评分值均明显低于女性（P〈0.05或P〈0.01）,女性偏执评分值明显低于男性（P〈0.01）。大学本科及以上学历的灾民躯体化评分值明显低于大专、高中及中专、初中、小学（P〈0.05或P〈0.01）,大学本科及以上学历的灾民强迫评分值明显高于小学（P〈0.01）,大专、高中及中专学历的灾民人际关系敏感评分值明显高于小学、文盲（P〈0.01）。4 666名灾民中难以保持熟睡者1 668人,占35.7%;常因其他事情想起此事者1 427人,占30.6%;难以入睡者1 402人,占30.0%;容易愤怒或生气者1 358人,占29.1%;不愿意、但还是想起此事者1 323人,占28.4%。结论江西省应以焦虑、强迫、躯体化及江西南部地区、女性、高学历的灾民为重点开展心理干预工作。     

Biostabilization and erodibility of cohesive sediment deposits in wildfire-affected streams

The erosion characteristics and bed stability of wildfire-affected stream sediment were measured in an annular flume. Biofilms were grown in the flume on cohesive streambed sediments collected from a wildfire affected stream and a reference undisturbed stream in southern Alberta, Canada. Examined factors that influence sediment erosion, settling and bed stability included applied shear stress, geochemical and physical properties of the sediment, floc structural characteristics and consolidation period (2, 7, 14 days). Erosion characteristics and sediment properties were strongly influenced by wildfire, consolidation period and bed biostabilization. The fire-modified sediment was more resistant to erosion than the reference unburned sediment. Settling velocities were lower in the burned sediment due to higher organic content and porosity. The critical shear stresses for erosion were 1.6 and 1.8 times higher for the burn-associated sediment after 7 and 14 days of consolidation. The differences are related to the greater degree and spatial extent (depth) of biofilm attachment in the burned sediment. Erosion depths were 4-8 times higher in burned sediment as a result of wildfire-associated biostabilization.     

三光集成型精确山火定位监测仪

描述了该山火监测设备的硬件组成、火光和烟雾自动识别算法和高精度定位方法,通过真型电力线路故障引发山火的试验和历史山火烟雾图像验证了该设备的指标和性能。实际试验表明,该设备在传统的可见光红外监测摄像头的基础上,增加火光和烟雾自动识别算法和高精度定位方法,能够在山火发生初始阶段有效监测识别,对于电力线路防山火有较大实际意义。     

Nasal hyperreactivity in allergic and non-allergic rhinitis: a potential risk factor for non-specific building-related illness

Self-reported non-allergic nasal symptom triggers in non-allergic ('vasomotor') rhinitis overlap with commonly identified environmental exposures in non-specific building-related illness. These include extremes of temperature and humidity, cleaning products, fragrances, and tobacco smoke. Some individuals with allergic rhinitis also report non-allergic triggers. We wished to explore the phenotypic overlap between allergic and non-allergic rhinitis by ascertaining self-reported non-allergic nasal symptom triggers among allergic rhinitics. Sixty subjects without work-related respiratory exposures or symptoms, aged 19-68 years, stratified by age, gender and (skin test-proven) allergic rhinitis status, were queried with regard to self-reported non-allergic nasal symptom triggers (aggregate score 0-8). In this sample, the number of self-reported non-allergic triggers was bimodal, with peaks at 1 and 5. Forty-two percent of seasonal allergic rhinitic subjects reported more than three non-allergic triggers, compared with only 3% of non-allergic non-rhinitics (P < 0.01). Subjects over 35 years were more likely to report one or more non-allergic triggers, particularly tobacco smoke (P < 0.05). Allergic rhinitics reported more non-allergic symptom triggers than did non-allergic, non-rhinitics. As indexed by self-reported reactivity to non-specific physical and chemical triggers, both non-allergic rhinitics and a subset of allergic rhinitics may constitute susceptible populations for non-specific building-related illness. PRACTICAL IMPLICATIONS: Judging by self-report, a substantial subset of individuals with allergic rhinitis--along with all individuals with nonallergic rhinitis (by definition)--are hyperreactive to non-allergic triggers. There is overlap between these triggers (elicited in the process of obtaining a clinical diagnosis) and environmental characteristics associated with 'problem buildings.' Since individuals with self-identified rhinitis report an excess of symptoms in most epidemiologic studies of problem buildings (even in the absence of unusual aeroallergen levels), rhintics may be acting as a 'sentinel' subgroup when indoor air quality is suboptimal. Together, non-allergic rhinitics plus allergic rhinitics with prominent non-allergic triggers, are thought to constitute approximately one-sixth of the US population.