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1.
Snow avalanche hazards in mountainous areas of developing countries have received scant attention in the scientific literature. The purpose of this paper is to describe this hazard and mitigative measures in Kaghan Valley, Pakistan Himalaya, and to review alternatives for future reduction of this hazard. Snow avalanches have long posed a hazard and risk to indigenous populations of the Himalaya and Trans-Himalaya mountains. Land use intensification due to population growth, new transportation routes, military activity and tourism is raising levels of risk. The history of land use in the study area is such that investigations of avalanche hazard must rely on different theoretical bases and data than in most industrialised countries. Despite the intensive use of valley-bottom land which is affected by avalanches, a number of simple measures are currently employed by the indigenous population to mitigate the hazard. Out-migration during the winter months is the most important one. During the intensive use period of summer avalanche-transported snow provides numerous resources for the population. In Kaghan the avalanche hazard is increasing primarily as a result of poorly located new buildings and other construction projects. The large scale of avalanche activity there rules out any significant improvement or protection of the currently difficult winter access. Instead, future mitigation of the hazard should focus on protecting the small number of winter inhabitants and minimising property damage. 相似文献
2.
Peter Höller 《Natural Hazards》2007,43(1):81-101
At all times natural hazards like torrents or avalanches pose a threat to settlements and infrastructures in the Austrian
Alps. Since 1950 more than 1,600 persons have been killed by avalanches in Austria, which is on average approximately 30 fatalities
per year. In particular, the winter periods 1950/1951 and 1953/1954 stand out with more than 100 fatalities. Those events
led to an increase of avalanche control programmes in the following decades. While from the 1950s to the 1970s emphasis was
placed on permanent measures (technical structures, afforestations, hazard zoning ...) additional programmes such as avalanche
warning and forecasting have supplemented avalanche control measures in the last decades. Current research is focused on avalanche
simulation, risk management and the influence of the forest on avalanche formation. An important area of future research is
to develop improved methods for avalanche forecasting and to intensify the investigation of the dynamics of avalanches. 相似文献
3.
The occurrence of wet-snow avalanches is, in general, poorly understood. For 20 years (winters of 1975–1976 to 1994–1995),
the avalanche activity has been observed in the Dischma valley near Davos (Eastern Swiss Alps). The study area comprises a
large starting zone of north-easterly aspect (2,300 m a.s.l.) with several avalanche paths. We have analyzed the occurrence
data in combination with meteorological and snowpack data collected at an elevation of 2,090 m a.s.l. During the 20-year observation
period, almost 800 wet-snow avalanches were observed, about 4.5 times more loose snow avalanches than slab avalanches. Considering
both types of avalanches jointly, snow depth, precipitation and air temperature showed the highest correlation with avalanche
activity. Most loose snow avalanches occurred when air temperature was high and/or after a precipitation period. Slab avalanches
occurrence was primarily related to warm air temperatures and snowpack properties such as the isothermal state and the existence
of capillary barriers. Radiation did not show up as a significant variable. The results suggest that in a transitional snow
climate wet-snow avalanches are, as dry snow avalanches, often related to precipitation events, and that wet slab instability
strongly depends on snowpack properties in relation to warming of the snowpack and melt water production. 相似文献
4.
Nesibe Köse Abdurrahim Aydın Ünal Akkemik Hüseyin Yurtseven Tuncay Güner 《Natural Hazards》2010,54(2):435-449
Many parts of our planet are exposed to natural disasters such as snow avalanches, floods and earthquakes. Detailed knowledge
on these natural disasters is crucial for human safety. On December 25–26, 1992, two avalanches occurred at Kayaarkası-Kastamonu
in northern Turkey. The first avalanche took place at night of 25–26 December and caused no damage. The second avalanche took
place at morning of 26 December, killed four people and did damage to properties. The purpose of the present study is to determine
the effects of the snow avalanches on tree rings and to investigate the boundaries and velocities of the avalanches using
a numerical simulation model and the tree-ring data. Increment cores from 71 trees in the avalanche-impacted area and the
control site were sampled to obtain individual standard chronologies. In the analyses, trees were grouped as (1) heavily damaged
by the avalanche, showing a decrease in tree-ring widths since the event, (2) trees heavily damaged by the avalanche, showing
an increase in tree-ring widths a couple of years later the event and (3) trees that were not damaged by the avalanche. In
this study, one of the most important results is the precise determination of the temporal and spatial patterns of the undocumented
avalanche (the first avalanche) event. Avalanches were numerically simulated using dynamical avalanche simulation software
ELBA+. Comparison of the simulation model with tree-ring analysis revealed valuable results about the boundaries of the zone
of influence of the avalanches. 相似文献
5.
Snow avalanches are a major natural hazard for road users and infrastructure in northern Gaspésie. Over the past 11 years, the occurrence of nearly 500 snow avalanches on the two major roads servicing the area was reported. No management program is currently operational. In this study, we analyze the weather patterns promoting snow avalanche initiation and use logistic regression (LR) to calculate the probability of avalanche occurrence on a daily basis. We then test the best LR models over the 2012–2013 season in an operational forecasting perspective: Each day, the probability of occurrence (0–100%) determined by the model was classified into five classes avalanche danger scale. Our results show that avalanche occurrence along the coast is best predicted by 2 days of accrued snowfall [in water equivalent (WE)], daily rainfall, and wind speed. In the valley, the most significant predictive variables are 3 days of accrued snowfall (WE), daily rainfall, and the preceding 2 days of thermal amplitude. The large scree slopes located along the coast and exposed to strong winds tend to be more reactive to direct snow accumulation than the inner-valley slopes. Therefore, the probability of avalanche occurrence increases rapidly during a snowfall. The slopes located in the valley are less responsive to snow loading. The LR models developed prove to be an efficient tool to forecast days with high levels of snow avalanche activity. Finally, we discuss how road maintenance managers can use this forecasting tool to improve decision making and risk rendering on a daily basis. 相似文献
6.
冰-岩碎屑流是高寒山区陡峭山体斜坡区冰崩、岩崩或滑坡解体后形成的冰屑、岩块和土颗粒混合体高速流动现象.由于裹挟了冰屑,冰-岩碎屑流具有超强的运动性,屡屡引发震惊世人的灾难性事件,是全球气候变暖大背景下地质灾害研究的热点与前沿问题.通过对近40余年来的研究进展进行梳理和评述,指出了冰-岩碎屑流的概念由来和主流定义方法,阐述了其成因机制的气候敏感性,结合典型实例论述了区域发育特征,重点分析了运动特征、减阻机理和冰屑影响机制.冰-岩碎屑流的超强运动性被认为与低摩擦冰减阻机理、摩擦热融减阻机理、侧限约束减阻机理密切相关.冰屑作为材料组分和融水来源,能够降低界面摩擦、改变冰-水-岩相互作用,进而形成复杂的热-水-力耦合作用.今后应加强研究冰-岩碎屑流事件的成因机制和时空分布规律、运动特性和冰屑影响机制、过程演化观测与预警评估技术,以期揭示冰-岩碎屑流运动机理,为冰-岩碎屑流及链生灾害的科学减灾提供有力支撑. 相似文献
7.
雪崩是冰冻圈内主要的自然灾害之一,严重威胁高寒山区内的交通廊道、能源输送和通信干线、矿区、牧区、旅游区等安全并造成基础设施毁坏和人畜死伤,阻碍山区社会经济的可持续发展。随着气候变化和人类活动不断向高寒山区扩展,暴露在雪崩危险之下的人口及基础设施日趋增多,雪崩的风险显著增强。为保障山区的社会经济可持续发展,对雪崩灾害防治管理需求不断增加。在梳理我国1960年以来主要雪崩研究进展基础上,结合世界各地雪崩研究成果,总结了雪崩的影响因素和区域规律、雪崩的形成与运动机理、雪崩监测预警、雪崩风险评估和雪崩工程防治等方面的进展和亟须研究的前沿问题以及科学难点。同时本文论述了气候变化对雪崩活动的影响,以及人类活动与雪崩活动之间的相互影响,展望了未来雪崩防灾减灾的需求并提出对策,推动雪崩防灾减灾研究。 相似文献
8.
P. Höller 《Natural Hazards》2014,71(3):1259-1288
Snow gliding is a downhill motion of snow on the ground; it is able to affect afforestation (uprooting of plants) and to cause soil erosion. Once the glide motion turns into an avalanche movement, the process is called a glide avalanche. Winters with continuing snow gliding and a high activity of glide avalanches might be called ‘glide winters’. The most recent ‘glide winter’ in the European Alps was 2011/2012. Glide avalanches have the ability to cause damage to buildings and infrastructure. This review describes the progress in research, from basic snow glide measurements via the design of sophisticated models through to comprehensive investigations concerning glide avalanche formation. However, despite the great progress made in this field of research, there are still some unsolved problems, such as the influence of soil conditions on snow gliding or the prediction of glide avalanches. 相似文献
9.
Sven Fuchs Magdalena Thöni Maria Christina McAlpin Urs Gruber Michael Bründl 《Natural Hazards》2007,41(1):113-129
This paper demonstrates the application of cost effectiveness analysis and cost benefit analysis to alternative avalanche
risk reduction strategies in Davos, Switzerland. The advantages as well as limitations of such analysis for natural hazards
planning are discussed with respect to 16 avalanche risk reduction strategies. Scenarios include risk reduction measures that
represent the main approaches to natural hazards planning in Switzerland, such as technical, organisational, and land use
planning measures. The methodologies used outline how concepts and techniques from risk analysis, hazard mapping, Geographic
Information System, and economics can be interdisciplinary combined. The results suggest important considerations, such as
possible sources of uncertainty due to different choices in the calculation of cost effectiveness ratio and net present value.
Given the parameters and assumptions, it seems as if the current approach to avalanche risk reduction in the study area approximates
to economic and cost efficiency and serves the aim of reducing risk to human fatalities. 相似文献
10.
Snow avalanches are a major natural hazard in the cryosphere. It seriously threatens transportation corridors, energy transmission and communication lines, mining and touristic areas in the cold mountainous regions and often causes the destruction of infrastructure and human casualties, hindering the sustainable development of society and economy in mountainous areas. Under climate change and the expansion of human activities to alpine mountains, more population and infrastructure will expose to the risk of avalanches. In order to ensure the sustainable development in mountainous areas, the demand for the prevention and management of avalanche disasters is increasing. Based on the review of the main avalanche research progress in China since 1960 and the avalanche research results all over the world, this paper summarized the progress on the influencing factors and regional distribution of avalanche activities, avalanche formation and movement mechanism, avalanche monitoring and early warning, avalanche risk assessment and engineering prevention, as well as the frontier problems and scientific difficulties that need to be studied. In addition, the impact of climate change on avalanche activities and the interaction between human activities and avalanche activities are discussed. By looking forward to the future needs of avalanche disaster prevention and reduction, including the countermeasures, the research on avalanche in China is promoted. © 2022 by the Author(s). 相似文献
11.
梅里雪山雪崩多发,但缺乏系统监测和研究。1991年1月3日梅里雪山发生了造成中日联合登山队17名队员遇难的巨大雪崩事件。2019年安装在明永冰川末端附近的物候相机拍摄到临近梅里雪山明永冰川的一次雪崩事件。两次事件类型不同,这对我们进行雪崩预测预警有良好的指示作用。本研究以RAMMS(Rapid Mass Movement System)模型为手段,利用经验值和经验公式确定影响模拟结果的主要模型参数和积雪可能断裂深度,在优化分析的基础上,对两次雪崩事件进行重建,定量分析雪崩堆积量、堆积范围等。结果显示:1991年雪崩共持续了192s,雪崩体从海拔5730m处断裂,沿坡面崩塌而下最终堆积在海拔约5000m的冰川粒雪盆地区,形成面积为0.6km^(2),体积约67×10^(4)m^(3)的堆积体。2019年雪崩共持续了158s,雪崩流最大高度35.91m,最大速度79.34m·s,堆积量76.2×10^(4)m^(3),雪崩堆积范围与野外观测到的一致。两次雪崩事件发生地位于雪崩极高危险区和高危险区,在一定程度上验证了风险评估的准确性。研究结果可为梅里雪山地区未来潜在雪崩灾害的风险评估提供依据,为雪崩预测预警提供良好的参考。 相似文献
12.
Peter Höller 《Natural Hazards》2009,48(3):399-424
During the last 50 years, an average of 30 persons per year was killed by avalanches in Austria. About one-third of all avalanche
fatalities occurred as a result of so-called ‘catastrophic avalanches’. ‘Catastrophic avalanches’ are spontaneously released
avalanches that affect villages and cause damage to property (buildings, roads and other infrastructure). The biggest avalanche
events in Austria were in 1950/1951 (135 fatalities), in 1953/1954 (143 fatalities) and in February 1999, when 38 persons
were killed in Galtür and Valzur. This article deals with an analysis of nine major avalanche cycles in the last 55 years.
An avalanche cycle in this article is defined as 50 recorded avalanches of at least size 3 in two days and/or 5 persons killed
in villages within two days. The basis of this study are the well-documented records from Fliri (1998), who analysed natural
disasters in the western part of Austria and the Trentino, including floods, mudflows, earthquakes and avalanches. The meteorological
data were taken from two relevant observation sites in the northern part of the Austrian Alps, from two sites in an intermediate
and continental region, respectively and from one site in the southern part of the Austrian Alps. Atmospheric patterns were
analysed by using weather charts for the relevant periods. Both the meteorological data and the weather charts were provided
by the Central Institute for Meteorology and Geodynamics (ZAMG). It was found that there was a major cycle every 6 years (on
average). Two-thirds of all investigated cycles were characterised by a continuous increase of snow depth over a period of
at least three days. In only three periods (1975, 1986, 1988), daily extreme values could be observed. More than 40% of all
the cycles occurred in January. In two-thirds, a north-westerly oriented frontal zone was responsible for the formation of
a major cycle. The remaining cycles were released by low-pressure areas over Central Europe and the Mediterranean Sea, respectively. 相似文献
13.
Bangladesh is one of the most natural hazard-prone countries in the world with the greatest negative consequences being associated with cyclones, devastating floods, riverbank erosion, drought, earthquake, and arsenic contamination, etc. One way or other, these natural hazards engulfed every corner of Bangladesh. The main aim of this research paper is to carry out a multi-hazards risk and vulnerability assessment for the coastal Matlab municipality in Bangladesh and to recommend possible mitigation measures. To this aim, hazards are prioritized by integrating SMUG and FEMA models, and a participation process is implemented so as to involve community both in the risk assessment and in the identification of adaptation strategies. The Matlab municipality is highly vulnerable to several natural hazards such as cyclones, floods, and riverbank erosion. The SMUG is a qualitative assessment, while FEMA is a quantitative assessment of hazards. The FEMA model suggests a threshold of highest 100 points. All hazards that total more than 100 points may receive higher priority in emergency preparedness and mitigation measures. The FEMA model, because it judges each hazard individually in a numerical manner, may provide more satisfying results than the SMUG system. The spatial distributions of hazard, risk, social institutions, land use, and other resources indicate that the flood disaster is the top environmental problem of Matlab municipality. Hazard-specific probable mitigation measures are recommended with the discussion of local community. Finally, this study tries to provide insights into the way field research combining scientific assessments tools such as SMUG and FEMA could feed evidence-based decision-making processes for mitigation in vulnerable communities. 相似文献
14.
Chris Stethem Bruce Jamieson Peter Schaerer David Liverman Daniel Germain Simon Walker 《Natural Hazards》2003,28(2-3):487-515
Snow avalanches affect recreation, transportation, resource industries and property. During the 1990s an average of 12.5 persons per year were killed in avalanches in Canada. The snow avalanche hazard has affected people and facilities in B.C, Alberta, Yukon, NWT, Nunavut, Ontario, Quebec and Newfoundland. Avalanche risk may be voluntary, for example skiing and snowmobiling, or involuntary, for example public transportation corridors. A worst-case avalanche scenario is most likely to occur in the Western Cordillera, resulting from a single large-scale weather pattern, where a cold period resulting in the development of a weak layer in the snowpack is followed by a series of major mid-winter storms. Emergency preparedness for avalanches is most advanced in western Canada. New education and information initiatives in Quebec and Newfoundland are aimed at improving preparedness there. Current research is focused on avalanche forecasting, weather forecasting for avalanche prediction, avalanche failure characteristics, forestry and avalanches and geomorphology and avalanches. An important area of future research is the impact of climate change on avalanches, particularly in northern Canada. 相似文献
15.
This article is intended to explain the snow avalanche occurrence, as a natural phenomenon directly influenced by the local natural conditions, for the well-delimited area represented by the Piatra Mica massif, belonging to the Piatra Craiului mountain range (southern Carpathians). In this respect, depending on the factors that may trigger or encourage the avalanches, some vulnerable areas with avalanche occurring conditions have been identified, based on the analysis of the relationships among the factors controlling the avalanche vulnerability in the study area. These factors are mainly represented by the slope aspect, which induces from the very beginning some specific features for each type of slope (north-, east-, south and west-facing slopes), the geological structure, slope gradient and topography. At the same time, the general climatic and biological features have been taken into account, from the point of view of their importance for avalanche occurrence and distribution. Depending on the microrelief exhibited by the avalanche chutes, one can establish distinct dynamical features for each of the four major slopes of the massif. It is worth mentioning that for this study area, this is the first paper dealing with avalanche phenomenon, vulnerable space, control factors and landscape dynamics. In accomplishing this demarche, we used detailed mappings in the field in several stages, the processing of satellite images, analytical (declivities, the exposure of slopes, etc.) and synthetic maps from which the dynamic of sectors with avalanches resulted. The findings of this investigation may further be employed for solving the problems raised by avalanche-prone areas, as well as for devising a better strategy for the effective management of the mountain realm. 相似文献
16.
Automated detection of snow avalanches is an important tool for avalanche forecasting and for assessing the effectiveness of avalanche control measures at bad visibility. Avalanche detection systems are usually based on infrasound, seismic, or radar signals. Within this study, we compared three different types of avalanche detection systems: one avalanche radar, one infrasound array system consisting of four infrasound sensors, and a newly developed single sensor infrasound system. A special focus is given to the new single sensor system, which is a low cost, easy to install system, originally designed for the detection of debris flows and debris floods. Within this work, we analysed how this single sensor system could be adapted to detect also snow avalanches. All three systems were installed close to a road near Ischgl (Tyrol, Austria) at the avalanche-exposed Paznaun Valley. The valley is endangered by two avalanche paths which are controlled by several avalanche towers. The radar system detected avalanches accurately and reliably but was limited to the particular avalanche path towards which the radar beam was directed. The infrasound array could detect avalanches from all surrounding avalanche paths, however, with a higher effort for installation. The newly tested single infrasound sensor system was significantly cheaper and easier to install than the other two systems. It could also detect avalanches form all directions, although without information about the direction. In summary, each of the three different systems was able to successfully detect avalanches and had its particular strengths and weaknesses, which should be considered according to the specific requirements of a particular practical application. 相似文献
17.
D. M. McClung 《Natural Hazards》2014,72(2):1139-1158
Since human triggering is responsible for about 90 % of deaths from slab avalanches in Europe and North America, risk analysis is very important for skier triggering of avalanches. The depth to the weak layer and the slope angle are two key measureable quantities prior to dry slab avalanche release. Both are important in risk analysis. The probability of avalanche release dramatically increases as the slope angle increases above 25°. As the slab depth increases, the consequences increase rapidly if an avalanche releases. Simple risk analyses for skier triggering were done for both slope angle and slab depth. The slab depth analysis showed there is a range of about 0.6–1.0 m for which the risk of death is highest. For slope angles, the range with highest risk was shown to be 33°–45° within the known range (25°–55°) for skier-triggered avalanches. 相似文献
18.
Recent natural hazards have exposed the dire consequence of damage and impact upon the built environment. It appears that one of the biggest challenges to the natural hazard mitigation community is how to improve the performance of older building and infrastructure to enhance their ability to withstand natural hazards. By improving their performance, the risk associated with buildings and infrastructure against natural hazards can be mitigated. Within the context of risk management of buildings against earthquakes, the general practice is to follow a three-step process, namely screening, evaluation and mitigation. Screening constitutes a preliminary evaluation process and sets priority for detailed evaluation. Evaluation compares a built environment with code requirements for new construction and sets priority for mitigation. Mitigation can be achieved by means of retrofit or replacement. Retrofit is intended to improve the performance of built environment as required. Replacement may be the only viable solution when economical, technical and environmental considerations are account for. 相似文献
19.
Ibrahim Gürer Harun Tunçel Ö. Murat Yavaş Tarhan Erenbılge Ayhan Sayin 《Natural Hazards》1995,11(1):1-16
Snow avalanches take place in the mountainous regions of Turkey mostly in the eastern Anatolia Region with an average annual death toll of 23 people and much damage to property. However, in the mountainous areas of the Kastamonu and Sinop provinces in the western part of the Black Sea Region of Turkey between 25 and 30 December 1992, blizzards with heavy snowfall caused roof collapses and major avalanche events whereby 16 people were killed and 2 injured. When past records were investigated, there was no evidence that avalanche accidents had been encountered in the region where the dominant precipitation type is rain in the coastal zones and snow over the mountains. Moreover, avalanche prevention measures are so limited that the resettlement of villages or hamlets located in risk zones is common practice. In this article, avalanche formation associated with the meteorological conditions and geomorphologic features is discussed.This study was partially supported by Tübitak (Scientific and Technical Research Council of Turkey) with Project No. YBAG-0067. 相似文献
20.
The physical risk from snow avalanches poses a serious threat to mountain backcountry travelers. Avalanche risk is primarily managed by (1) assessing avalanche hazard through analysis of the local weather, snowpack, and recent avalanche activity and (2) selecting terrain that limits exposure to the identified hazard. Professional ski guides have a tremendous wealth of knowledge about using terrain to manage avalanche risk, but their expertise is tacit, which makes it difficult for them to explicitly articulate the underlying decision rules. To make this existing expertise more broadly accessible, this study examines whether it is possible to derive quantitative measures for avalanche terrain severity and condition-dependent terrain guidance directly from observed terrain selection of professional guides. We equipped lead guides at Mike Wiegele Helicopter Skiing with GPS tracking units during the 2014/2015 and 2015/2016 winters creating a dataset of 10,592 high-resolution tracked ski runs. We used four characteristics—incline, vegetation, down-slope curvature (convexities/concavities), and cross-slope curvature (gullies/ridges)—to describe the skied terrain and employed a mixed-effects ordered logistic regression model to examine the relationship between the character of most severe avalanche terrain skied on a day and the associated field-validated avalanche hazard ratings. Patterns in the regression parameter estimates reflected the existing understanding of how terrain is selected to manage avalanche risk well: the guides skied steeper, less dense vegetation, and more convoluted slopes during times of lower avalanche hazard. Avalanche terrain severity scores derived from the parameter estimates compared well to terrain previously zoned according to the Avalanche Terrain Exposure Scale. Using a GIS implementation of the regression analysis, we created avalanche condition-dependent maps that provide insights into what type of terrain guides deemed acceptable for skiing under different avalanche hazard conditions. These promising results highlight the potential of tracking guides’ terrain selection decisions as they manage avalanche hazard for the development of evidence-based avalanche terrain ratings and decision aids for professional and recreational backcountry travelers. 相似文献