Spatial and temporal analysis of natural hazard mortality in Nepal

The impacts of natural hazards are typically measured in terms of loss of human lives and economic damage, and recent studies demonstrate that deaths attributed to natural hazards have increased. Using the publicly available DesInventar database, we examined spatial and temporal patterns of natural hazard mortality from 1971 to 2011 at the district and village levels of Nepal and identified natural hazards that contributed most to mortality. Spatial clusters of mortality at the district and village levels were detected using local and global spatial autocorrelation measures (Moran's I). Landslides (41.91%) and floods (32.52%) accounted for approximately three quarters of natural hazard mortalities over the study period. A Global Moran's I test positively confirmed clustering at both the district (0.199, p?p?相似文献   

近场地震下评估单层网壳响应的地震动强度参数分析

为了选取近场地震动作用下适于评估单层网壳结构响应的地震动强度参数,以3个矢跨比不同的单层球面网壳和5个矢跨比、长宽比不同的单层柱面网壳为模型,从相关性、有效性及充分性3个方面对多个地震动强度参数进行分析评价。结果表明,对于单层球面网壳结构,水平向的相关系数大于竖向的相关系数.加速度反应谱值S_a(T_1)和S_a(T_2)为近场地震动作用下适于评估单层球面网壳结构响应的地震动强度参数;对于单层柱面网壳结构,跨度方向的相关系数大于长度方向和竖向的相关系数,近场地震动作用下适于评估单层柱面网壳结构响应的地震动强度参数为S_a(T)、速度反应谱值S_v(T)和位移反应谱值S_d(T),当单层柱面网壳的长宽比和矢跨比较大时,T应取第一阶振型的自振周期T_1,当单层柱面网壳的长宽比和矢跨比较小时,T应取第二、三阶振型的自振周期T_2和T_3。     

Understanding recovery of small enterprises from natural disaster

This study, carried out among 251 small-scale firm owners by means of a cross-sectional survey, attempted to identify the factors affecting business recovery from disaster in a flood-prone area of Bangladesh. We selected the participants by using a convenience sampling technique, taking into consideration the characteristics of the firms, and the various enabling- and disaster-impact factors needed to identify those factors significant to business recovery from natural disaster. Results demonstrated that more than three-quarters (87.3%) of owners recovered their firms after disaster. Multivariate logistic regression analyses revealed that a total of six variables had a significant impact on business recovery: two variables pertaining to the firms’ characteristics, namely, retail firms (OR?=?0.147, P?<?0.05) and the number of employees >4 (OR?=?0.094, P?<?0.01); two variables pertaining to enabling factors, namely, receiving loans (OR?=?0.232, P?<?0.01) and the perception of recovery (OR?=?16.178, P?<?0.01); and two variables pertaining to disaster-impact factors, namely, an income loss amounting to >BDT 2000 (OR?=?7.395, P?<?0.05) and permanent or temporary relocation of the market (OR?=?9.252, P?<?0.001). Results further demonstrated that almost equally half of the owners recovered their firms immediately or within 7 days after disaster (50.9%); the remaining 49.1% took longer. Multivariate analyses, on the other hand, significantly identified three characteristics, namely, 6–10 years of business operation (OR?=?0.267, P?<?0.01), 2–4 employees (OR?=?0.1.822, P?<?0.01), and a monthly income of BDT 5001–7500 (OR?=?4.167, P?<?0.01); two enabling factors, namely, institutional education (OR?=?0.400, P?<?0.05) and awareness of disaster assistance (OR?=?0.607, P?<?0.05); and two disaster-impact factors, namely, loss of human resources (OR?=?6.293, P?<?0.05) and interrupted supply of raw materials (OR?=?4.741, P?<?0.05). We concluded the study with discussions of a few policy implications.     

基于Ap/Vp的双薄壁高墩刚构桥抗震性能研究

为了研究地震频谱特性对柔性桥梁抗震性能的影响,以正弦波为例推导了地震动能量与A_p/V_p的关系,基于能力需求比提出了桥梁抗震性能评估方法及计算公式。以某典型高墩连续刚构桥为工程背景,采用地震动参数A_p=0.4g的22条正弦波和7条实际地震记录,对比研究了桥梁纵、横向抗震性能随A_p/V_p的变化规律。结果表明:在地震动参数A_p相同的情况下,桥梁关键截面抗震能力需求比在纵、横桥向均随A_p/V_p的增大而呈现增长的规律,最大增幅超过12.92倍(正弦波)和2.31倍(实际波);按正弦波得到能力需求比普遍大于实际波,且随A_p/V_p增大而增大的规律更明显。研究发现将地震动参数A_p作为单一的抗震设计指标会导致桥梁抗震性能离散性很大,A_p/V_p可作为柔性桥梁抗震设计的补充指标。     

多类型地震动作用下高层结构的易损性分析

以低频成分为主的长周期地震动容易引起中、长周期结构的破坏,针对这类特殊的地震动,现行抗震规范没有相应的条文,且有关单独考虑长周期地震动作用下结构动力响应的研究成果很少。以一个30层框架剪力墙高层结构为例,利用Perform-3D三维有限元软件进行建模,选取10条远场长周期地震动、10条近场长周期地震动以及10条普通地震动,将最大层间位移角作为工程需求参数,S_a(T₁,5%)作为地震强度指标。基于增量动力分析方法对该结构进行动力时程分析,并定义了4个结构性能水平,然后统计不同地震强度下的结构需求,获取地震易损性曲线,最终对比评价了三类地震动作用下结构的易损性。     

冷却塔塔筒荷载效应和简化设计方法——各荷载单独作用分析

为简化冷却塔塔筒配筋设计中的多风向计算问题,应明确塔筒在各荷载单独作用下的内力特征。以某冷却塔为例并配以代表性的荷载取值,对其自重、风、冬温和夏温、水平和竖向地震这6类荷载的内力状态进行了单独分析和系统对比,着眼于各自的主要内力和各内力环向分布特征。结果表明,自重、冬温和竖向地震作用下内力的环向均匀分布使其无碍于荷载效应的方向组合;夏温和水平地震的最不利内力固定在某一子午线上且各自分别以弯矩和轴力为主,两者方向一致时即自然形成最不利组合;风荷载方向的任意性、复杂的内力分布特征和轴弯联合作用使常规荷载效应组合中必须进行多风向计算,但其内力分布特征依然给荷载效应组合的简化提供了可能。     

SF6设备中分解产物分析研究

针对SF₆设备运行中出现的问题,对SF₆气体分解产物的含量情况进行分析研究,为SF₆设备的在线诊断分析提供可靠数据。结果表明:SF₆气体分解产物的含量分析结果可作为设备故障分析和状态检修的参考依据。     

深厚第四纪沉积土非线性性能对地表地震动特性的影响∗

土体非线性性能对地表地震动的影响主要体现在其频谱成分和强度的改变上。采用修正Matasovic本构模型描述土的动力非线性特性,利用专业软件DeepSoil对深厚场地的50个钻孔剖面土柱模型进行了场地地震反应分析。采用加速度反应谱卓越周期T_p、平均谱周期T_avg及加速度傅氏谱平均周期T_m表征地表地震动频谱特性;以Arias强度I_a和地表峰值加速度PGA表征地表地震动强度。结果表明：(1) 特定场地条件下,T_p不能反映土体非线性对地震动从基岩传播至地表时频谱成分变化的影响;T_avg和T_m在表征地震动频谱成分特性时具有较高的一致性;(2) 基岩地震动高频丰富时,T_avg和T_m随着基岩地震动峰值加速度的增大而呈现出线性增长的趋势;而基岩地震动低频较发育时,T_avg和T_m的增长趋势线存在明显的拐点;（3）PGA与I_a值随基岩地震动峰值加速度的增大呈现出基本一致的非线性增长趋势,且其离散性均随基岩峰值加速度的增大而增大。     

非塑性细粒粒径与含量对饱和砂类土强度的影响∗

松散状态下的饱和砂类土受剪切后出现静态液化现象,且受到细粒含量、颗粒级配、固结围压等因素的影响。而目前对于中密状态下砂类土的相关研究鲜有报道,特别对于细粒粒径的影响研究尚少。采用福建标准砂与三种不同粒径的石英粉进行混合,开展了一系列三轴不排水压缩试验。试验中保持所有土样的相对密度相同,相对密度控制为 50%,同时还考虑了细粒含量(FC = 10%,20%,30%)、围压(50,100,200 kPa)等因素的影响。试验结果表明:相同细粒含量下随着标准砂平均粒径与石英粉平均粒径比 R_d的增大(Rd = 10~65.76),最大孔隙比和最小孔隙比均有增大趋势;在细粒含量较低时(FC = 10% 和 20%),峰值偏应力随着 R_d的增大呈现近似线性递减关系,而在细粒含量较高时(FC =30%),峰值偏应力在 R_d达到某个临界值迅速下降,而后基本保持不变或者缓慢下降;中等密实状态的砂类土在高细粒含量的情况下可发生静态液化,且平均粒径比 R_d越大静态液化越容易发生,因此,评估饱和砂类土的强度需要考虑非塑性细粒粒径的不利影响。     

Evaluation of Two Kurdish Refugee Camps in Iran, May 1991: The Value of Cluster Sampling in Producing Priorities and Policy

Following the end of the Gulf war in March 1991, Kurdish refugees from Iraq crossed the border into Western Iran. To plan public health interventions and to assist in priority setting for scarce resources, a rapid epidemiological assessment of two camps, Hafez and Kaliche, was conducted in May 1991. A 30 cluster sampling method was used to determine the demographics of the camp population, the morbidity and mortality from certain diseases, and the nutritional status of the children <5 years of age. The estimated population of the camps at the time of the survey was 28,500 and 22,500 for Hafez and Kaliche respectively; children < 5 years of age accounted for approximately 25 per cent of both camp populations. The mortality rate was highest in Hafez and estimated to be 2.5/10,000 per day (95%CI:0.3–5) for adults (> 14 years of age) and 4.9/10,000 per day (95%CI:2.4–7.4) for children. Diarrhoeal and respiratory diseases accounted for major morbidity in both camps with diarrhoea the commonest stated cause of death. Little malnutrition was found but it was greater in Hafez where 6 per cent (19/327) of the children between 1 and 5 years of age had a mid upper arm circumference (MUAC) <12 cm and eleven (5.2 per cent) of the 211 children measured for height and weight were below 80 per cent of the median (95%CI:2.6%;7.8%). The survey identified that morbidity and mortality were less severe than in the Kurdish camps on the Turkish border and provided information for camp authorities to plan appropriate relief interventions.     

Environmental equity in a sunbelt city: the spatial distribution of toxic hazards in Phoenix,Arizona

Abstract

This paper examines the spatial distributions of industrial facilities emitting toxic substances in the Phoenix, Arizona metropolitan region. The analysis relies on geographic information system mapping of hazardous facilities listed in the Environmental Protection Agency's Toxic Release Inventory (TRI) to assess the spatial distribution of polluting industries in relation to the demographic composition of host neighborhoods. The research addresses four questions: (1) Are there differences between the socioeconomic characteristics of neighborhoods with and without polluting industrial facilities? (2) Is there a relationship between the volume of toxic chemicals released from industrial facilities and the socioeconomic characteristics of host neighborhoods? (3) Is there a relationship between the toxicity of the chemicals released from industrial facilities and the socioeconomic characteristics of those living in proximity? (4) Do alternative methods for determining the distribution of potentially affected populations produce different observed patterns of environmental inequities? The study concludes that there is a clear pattern of environmental inequity in Phoenix based on the location and volume of emissions of TRI facilities. Analysis of the toxicity of emissions found a more equal distribution of risk, reflecting the suburbanization of high-technology industries into predominantly white middle-class communities.     

SF6气体密度继电器校验工作常见问题分析及处理

针对SF₆气体密度继电器检验工作中常见的气体泄漏、误动作以及因阀门问题导致难以校验等问题,对产生原因进行分析,提出相应的对策。分析结果表明:SF₆气体密度继电器校验工作中出现的问题涉及诸多因素,应遵守相关的规程、规定,准确分析故障原因,制定切实可行的解决方案和步骤加以解决,以确保校验工作的正确和设备的安全。     

BOOK REVIEWS

Book reviewed in this article: Hunger and Public Action, by Jean Drèze and Amartya Sen Global Warming: Are We Entering the Greenhouse Century?, by Stephen H. Schneider Climate Change and World Agriculture, by Martin Parry The Poor Die Young: Housing and Health in Third World Cities, edited by Jorge E. Hardoy     

Characterizing the urban heat island in current and future climates in New Jersey

Climate change caused by increased anthropogenic emissions of carbon dioxide (CO₂) and other greenhouse gases is a long-term climate hazard with the potential to alter the intensity, temporal pattern, and spatial extent of the urban heat island (UHI) in metropolitan regions. Particular meteorological conditions—including high temperature, low cloud cover, and low average wind speed—tend to intensify the heat island effect. Analyses of existing archived climate data for the vicinities of Newark and Camden, New Jersey indicate urban to suburban/rural temperature differences over the previous half-century. Surface temperatures derived from a Landsat thermal image for each site were also analyzed for spatial patterns of heat islands. Potential interactions between the UHI effect and projected changes in temperature, wind speed, and cloud cover are then examined under a range of climate change scenarios, encompassing different greenhouse gas emissions trajectories. The scenarios include those utilized in the Metropolitan East Coast Regional Assessment of Climate Variability and Change and the A2 and B2 scenarios of the Intergovernmental Panel on Climate Change (IPCC) Special Report on Emissions Scenarios (SRES).

The UHI effect was detected in Newark and Camden in both satellite surface-temperature and meteorological station airtemperature records. The average difference in urban—nonurban minimum temperatures was 3.0 °C for the Newark area and 1.5 °C for Camden. Extrapolation of current trends and the selected global climate models (GCMs) project that temperatures in the case study areas will continue to warm in the current century, as they have over the past half-century. An initial analysis of global climate scenarios shows that wind speed may decline, and that cloud cover may increase in the coming decades. These generally small countervailing tendencies suggest that urban—nonurban temperature differences may be maintained under climate change.

Overall warmer conditions throughout the year may extend the spatial and temporal dimensions of the urban-suburban heat complex. The incidence of heat-related morbidity and mortality are likely to increase with interactions between the increased frequency and duration of heat waves and the UHI effect. Camden and Newark will likely be subjected to higher temperatures, and areas experiencing UHI-like conditions and temperature extremes will expand. Thus, urban heat island-related hazard potential is likely to increase in a warmer climate.     

Reviews

Alex de Waal Famine Crimes: Politics and the Disaster Relief Industry in Africa Keith Smith Environmental Hazards: Assessing Risk and Reducing Disaster Kenneth Hewitt Regions of Risk: A Geographical Introduction to Disasters John Seaman The Public Health Consequences of Disasters John Prendergast Frontline Diplomacy. Humanitarian Aid and Conflict in Africa John Prendergast Crisis Response. Humanitarian Band-Aids in Sudan and Somalia Christopher Hood and David K.C. Jones Accident and Design: Contemporary Debates on Risk Management D. Hulme and M. Edwards NGOs, States and Donors. Too Close for Comfort? James C. Hathaway Reconceiving International Refugee Law Rhona Flin Sitting in the Hot Seat Donald Meichenbaum On Treating Post-Traumatic Stress Disorder: A Handbook and Practice Manual for Therapy R. Scarpa and R.I. Tilling Monitoring and Mitigation of Volcano Hazards Hanna Schmuck-Widmann Living with Floods: Survival Strategies of Char-dwellers in Bangladesh     

BOOK REVIEWS

Book reviewed in this article: Free at last? US Policy Toward Africa and the End of the Cold War by Michael Clough. Grasshoppers and Locusts: The Plague of the Sahel. Panos Dossier 5, Panos Publications Ltd. Evil Days: Thirty Years of War and Famine in Ethiopia. An Africa Watch Report. Human Rights Watch, New York, September 1991. Ban Vinai: The Refugee Camp by Lynellyn D. Long.     

The effectiveness of forecast-based humanitarian assistance in anticipation of extreme winters: a case study of vulnerable herders in Mongolia

This paper presents evidence relating to a forecast-based cash and non-food item distribution among vulnerable herder households during the 2017–18 dzud (extreme winter) season in Mongolia, and analyses the results of a quasi-experimental study evaluating its impacts. An innovative approach in disaster risk reduction, forecast-based financing (FbF) can have short- and long-term benefits to vulnerable households but remains understudied. The paper contributes information on a multimodal FbF programme offering one-off cash grants and in-kind veterinary kits. The data found significant effects of reduced mortality and increased offspring survival in some types of livestock, and that the timing of FbF assistance is crucial, as reported early assistance correlated to positive outcomes in terms of reduced animal mortality. These findings can be used to design more effective FbF interventions, to understand better the appropriateness of FbF designs, and to use early warnings and early actions to help people prepare and withstand disasters such as dzuds.     

BOOK REVIEWS

Book reviewed in this article: Famine and Food Security in Africa and Asia: Indigenous Response and External Intervention to Avoid Hunger, edited by Hans G. Bohle, Terry Cannon, Graeme Hugo and Fouad N. Ibrahim. When the Grass is Gone: Development Interventions in African Arid Lands, edited by P.T.W. Baxter. Survival Strategies and External Interventions in a Semi-arid Region at the Kenya/Uganda Border: Western Pokot, 1900–86, by Ton Dietz. Global Warming: Who is Taking the Heat?, by G. Foley     

双尺度低氮燃烧技术在国产330MW机组的应用

为了达到宁夏地区要求现役330 MW级别火电机组NOx排放值100 mg/Nm³以下和改善环境的目的,青铜峡铝业发电有限责任公司对1号锅炉的燃烧器进行技术改造。结果表明:改造后锅炉在330 MW负荷下NOx排放平均值为240 mg/Nm³,比改造前降低45%;锅炉效率达到93.39%(高于设计值0.01%)、飞灰含碳量2.98%(低于设计值0.02%)、过热器减温水量和再热器减温水量均小于设计值;有效解决了锅炉改造前的结焦和超温现象。     

云南极端霜冻气候事件的气候特征及环流背景分析

利用云南124个气象站逐日最低气温和天气现象(霜)资料,计算最低气温低于-5℃的站点数占全省总站数的比例,定义站点比例超出25%的霜冻事件为云南极端霜冻气候事件。分析了云南极端霜冻气候事件的气候特征及环流背景。结果表明,云南极端霜冻事件发生前气温偏低,云量偏多;霜冻发生时夜间晴朗,辐射散热强烈,气温再度下降。这种霜冻属于混合霜冻或称为平流辐射霜冻。极端霜冻气候事件发生的主要原因之一是高空冷平流与底层冷高压控制下夜间晴空辐射冷却降温。发生时空气湿度较发生前小,空气相对干燥。