气候变化背景下湖北省水稻高温热害变化规律研究   总被引：8，自引：0，他引：8       下载免费PDF全文

陈升孛 《气象与减灾研究》2013,36(2):51-56

利用历年气象资料,运用数理统计方法,分析了湖北省1951—2010年水稻高温热害的动态变化,探讨了气候变化背景下高温热害的演变趋势与规律。结果表明,鄂东部、江汉平原部分地区水稻高温热害发生趋于频繁,且除西南部地区外的湖北省其他地区水稻高温热害最大概率出现的时间均有明显的提前,甚至每10a提前1d以上。最后,利用ArcGIS对湖北省的水稻高温热害变化趋势和风险程度进行了区划。  相似文献   

The A.D. 79 eruption as a future explosive scenario in the Vesuvian area: evaluation of associated risk     

Lucio Lirer  Rosalba Munno  Immacolata Postiglione  Anna Vinci  Livia Vitelli 《Bulletin of Volcanology》1997,59(2):112-124

 Due to the lack of an effective policy of planning and prevention, over the past decades the area around Mt. Vesuvio has undergone a steady increase in population and uncontrolled housing development. Consequently, it has become one of the most hazardous volcanic areas in the world. In order to mitigate the damage that the impact of an explosive event would cause in the area, the Department of Civil Defense has worked out an Emergency Management Plan using the A.D. 1631 subplinian eruption as the most probable short-term event. However, from 25 000 years B.P. to present, the activity of the Somma-Vesuvio volcano has shown a sequence of eight eruptive cycles, which always began with a strong plinian eruption. In this paper we utilize the A.D. 79 eruption as an example of a potential large explosive eruption that might occur again at Vesuvio. A detailed tephrostratigraphic analysis of the eruption products was processed by a multivariate statistical analysis. This analysis proved useful for identifying marker layers in the sequences, thus allowing the recognition of some major phases of synchronous deposition and hence the definition of the chronological and spatial evolution of the eruption. By combining this reconstruction with land-use maps, a scenario is proposed with time intervals in the eruptive sequence similar to those reported in Pliny's letter. Thus, it was calculated that, after 7 h from the start of the eruption, a total area of approximately 300 km² would be covered with the eruption products. In the following 11 h, a total area of approximately 500 km² would be involved. The third and last phase of deposition would not cause significant variation in the total area involved, but it would bring about an increase in the thickness of the pyroclastic deposits in the perivolcanic area. Received: 30 November 1996 / Accepted: 29 May 1997  相似文献   

Volcanic risk ranking for Auckland, New Zealand. I: Methodology and hazard investigation     

Christina Magill  Russell Blong 《Bulletin of Volcanology》2005,67(4):331-339

Volcanic eruptions typically produce a number of hazards, and many regions are at risk from more than one volcano or volcanic field. So that detailed risk assessments can be carried out, it is necessary to rank potential volcanic hazards and events in terms of risk. As it is often difficult to make accurate predictions regarding the characteristics of future eruptions, a method for ranking hazards and events has been developed that does not rely on precise values. Risk is calculated individually for each hazard from each source as the product of likelihood, extent and effect, based on the parameters order of magnitude. So that multiple events and outcomes can be considered, risk is further multiplied by the relative probability of the event occurring (probability_e) and the relative importance of the outcome (importance_o). By adding the values obtained, total risk is calculated and a ranking can be carried out.This method was used to rank volcanic hazards and events that may impact the Auckland Region, New Zealand. Auckland is at risk from the Auckland volcanic field, Okataina volcanic centre, Taupo volcano, Tuhua volcano, Tongariro volcanic centre, and Mt. Taranaki volcano. Relative probabilities were determined for each event, with the highest given to Mt. Taranaki. Hazards considered were, for local events: tephra fall, scoria fall and ballistic impacts, lava flow, base surge and associated shock waves, tsunami, volcanic gases and acid rain, earthquakes and ground deformation, mudflows and mudfills, lightning and flooding; and for distal events: tephra fall, pyroclastic flows, poisonous gases and acid rain, mudflows and mudfills, climate variations and earthquakes. Hazards from each source were assigned values for likelihood, with the largest for tephra fall from all sources, earthquakes and ground deformation, lava flows, scoria fall and base surge for an Auckland eruption on land, and earthquakes and ground deformation from an Auckland eruption in the ocean. The largest values for extent were for tephra fall and climate variation from each of the distal centres. However, these parameters do not give a true indication of risk. In a companion paper the effect of each hazard is fully investigated and the risk ranking completed.  相似文献   

A case study of coping strategies and landslides in two villages of Central-Eastern Nepal     

Karen Sudmeier-Rieux  Stephanie Jaquet 《Applied geography (Sevenoaks, England)》2012,32(2):680-690

Landslides are an increasing problem in Nepal’s Middle Hills due to both natural and human phenomena: mainly increasingly intense monsoon rains and a boom in rural road construction. This problem has largely been neglected due to underreporting of losses and the dispersed nature of landslides. Understanding how populations cope with landslides is a first step toward developing more effective landslide risk management programs. The present research focuses on two villages in Central-Eastern Nepal, both affected by active landslides but with different coping strategies. Research methods are interdisciplinary, based on a geological assessment of landslide risk and a socio-economic study of the villages using household questionnaires, focus group discussions and transect walks. Community risk maps are compared with geological landslide risk maps to better understand and communicate community risk perceptions, priorities and coping strategies. A modified typology of coping strategies is presented, based on previous work by Burton, Kates, and White (1993) that is useful for decision-makers for designing more effective programs for landslide mitigation. Main findings underscore that coping strategies, mainly seeking external assistance and outmigration, are closely linked to access to resources, ethnicity/social status and levels of community organization. Conclusions include the importance of investing in organizational skills, while building on local knowledge about landslide mitigation for reducing landslide risk. There is great potential to increase coping strategies by incorporating skills training on landslide mitigation in existing agricultural outreach and community forest user group training.  相似文献   

雷击风险评估中L_o损失因子在多线路系统下的细化和改进     

植耀玲  冯民学  樊荣 《气象科学》2012,32(3):298-303

2008年推广施行的新国标GB/T 21714.2已广泛应用于各地雷击风险评估业务中。但在实际应用过程中人们也发现用其建立评估模型时,标准的一些简约化约定,使得其计算结果不够精准,特别是描述和处理也显得越来越困难,影响和制约了它的应用范围和前景。为此,本文针对带有多种电气和电子系统的复杂结构建筑,提出按其进线分布特点,对Lo损失因子取值方法进行改进(下文均称"Lo优化取值法"),为多线路进线建筑物的雷击风险管理提供更细化的依据和算法,并举例证实。结果表明:细化考虑不同线路的Lo对于建筑物雷击风险评估更为切近真实。  相似文献   

Droughts and famines: The underlying factors and the causal links among agro-pastoral households in semi-arid Makueni district, Kenya   总被引：4，自引：0，他引：4  

Chinwe Ifejika Speranza  Boniface Kiteme  Urs Wiesmann 《Global Environmental Change》2008,18(1):220-233

Famines are often linked to drought in semi-arid areas of Sub-Saharan Africa where not only pastoralists, but also increasingly agro-pastoralists are affected. This study addresses the interplay between drought and famine in the rural semi-arid areas of Makueni district, Kenya, by examining whether, and how crop production conditions and agro-pastoral strategies predispose smallholder households to drought-triggered food insecurity. If this hypothesis holds, then approaches to deal with drought and famine have to target factors causing household food insecurity during non-drought periods. Data from a longitudinal survey of 127 households, interviews, workshops, and daily rainfall records (1961–2003) were analysed using quantitative and qualitative methods. This integrated approach confirms the above hypothesis and reveals that factors other than rainfall, like asset and labour constraints, inadequate policy enforcement, as well as the poverty-driven inability to adopt risk-averse production systems play a key role. When linking these factors to the high rainfall variability, farmer-relevant definitions and forecasts of drought have to be applied.  相似文献   

Risk analysis for clustered check dams due to heavy rainfall   总被引：7，自引：1，他引：6  

Zuyu Chen  Xieping Huang  Shu Yu  Wei Cao  Weiqin Dang  Yangqiang Wang 《国际泥沙研究》2021,36(2):291-305

Check dams are commonly constructed around the world for alleviating soil erosion and preventing sedimentation of downstream rivers and reservoirs.Check dams are more vulnerable to failure due to their less stringent flood control standards compared to other dams.Determining the critical precipitation that will result in overtopping of a dam is a useful approach to assessing the risk of failure on a probabilistic basis and for providing early warning in case of an emergency.However,many check dams are built in groups,spreading in several tributaries in cascade forms,comprising a complex network.Determining the critical precipitation for dam overtopping requires a knowledge of its upstream dams on whether they survived or were overtopped during the same storm,while these upstream dams in turn need the information for their upstream dams.The current paper presents an approach of decomposing the dam cluster into(1)the heading dam,(2)border dams,and(3)intermediate dams.The algorithm begins with the border dams that have no upstream dams and proceeds with upgraded maps without the previous border dams until all the dams have been checked.It is believed that this approach is applicable for small-scale check dam systems where the time lag of flood routing can be neglected.As a pilot study,the current paper presents the analytical results for the Wangmaogou Check Dam System that has 22 dams connected in series and parallel.The algorithm clearly identified 7 surviving dams,with the remaining ones being overtopped for a storm of 179.6 mm in 12 h,which is associated with a return period of one in 200 years.  相似文献   

Making risk real: Urban trees and the ontological politics of risk     

《Geoforum》2014

Over the past several decades, risk has become a distinct field of social inquiry as scholars in a variety of disciplines have developed theories about the ‘nature’ of risk and the role it plays in contemporary society. Collectively, these theories enrich our understanding of the politics of risk, the dynamics of risk perception, and the way risk shapes and is shaped by space, culture, social change, and modes of governing in the neoliberal era. In this paper, however, we argue these theories are helpful but not entirely suited to understanding risk when it becomes the subject of something Whatmore (2009, p. 587, 2013) calls “environmental knowledge controversies”. These controversies are generative events where more-than-human agencies and the political and knowledge making practices of heterogeneous actors reshape our sense of the real. To address this issue, we draw on the concepts of enactment, multiplicity, and ontological politics to explore how different kinds of risk and tree were made more or less real during a contentious debate over the risk posed by a group of urban trees in Newcastle, Australia. This case study suggests we can think of risk and hazardous entities like trees as effects that also affect because they elicit interventions that transform bodies and spaces in more or less enduring ways. Attending to the enactment, multiplicity, and ontological politics of risk, we argue, provides an alternative way to navigate moments of political contestation over the assessment and management of risk that has implications for how these processes are conceived and conducted in the future.  相似文献   

A multi-level perspective on climate risks and drivers of entrepreneurial robustness – Findings from sectoral comparison in alpine Austria     

《Global Environmental Change》2017

Recent works on organizational adaptation to climate change have repeatedly stressed that – despite concerns about large-scale impacts of climate change on supply chain networks – studies on climate change adaptation in manufacturing industries are still surprisingly scarce. The following study develops a systemic analytical framework based on which climate risks for manufacturing industries are reviewed and drivers (defined as supportive factors) of entrepreneurial robustness are examined. The analysis builds upon a case study in the alpine Austrian state of Tyrol where an intense regional rise of average temperatures occurs, going along with increased risks of natural mountain hazards and exposed settlement structures. In this climate-sensitive setting the authors conducted a survey on risk perceptions among 102 managers from manufacturing firms. Based on a comparison of the sectors metal and engineering, timber products, and construction, the authors argue that drivers of entrepreneurial robustness can be subsumed under five major strategic principles: (a) the deployment of slack resources, (b) vertical supply chain integration, (c) manufacturing flexibility, (d) material efficiency, and (e) technological risk prevention. Departing from the empirical results, the authors argue that across these principles the development of drivers depends on an interplay of structural prerequisites and human decisions on the levels of the focal firm, the supply chain network, and the political, economic, and geographic environment. In this sense, the authors conceptualize different forms of contingencies – thus effects influencing the development of drivers – within an ontology which may support further system-oriented analysis of climate change adaptation in industry.  相似文献   

Understanding scientists’ computational modeling decisions about climate risk management strategies using values-informed mental models     

《Global Environmental Change》2017

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