Seismic fragility curves for greek bridges: methodology and case studies   总被引：2，自引：1，他引：1  

Ioannis F. Moschonas  Andreas J. Kappos  Panagiotis Panetsos  Vissarion Papadopoulos  Triantafyllos Makarios  Pavlos Thanopoulos 《Bulletin of Earthquake Engineering》2009,7(2):439-468

This study focusses on the estimation of seismic fragility curves for all common bridge types found in modern greek motorways. At first a classification scheme is developed in order to classify the existing bridges into a sufficient number of classes. A total of 11 representative bridge classes resulted, based on the type of piers, deck, and pier-to-deck connection. Then an analytical methodology for deriving fragility curves is proposed and applied to the representative bridge models. This procedure is based on pushover analysis of the entire bridge and definition of damage states in terms of parameters of the bridge pushover curves. The procedure differentiates the way of defining damage according to the seismic energy dissipation mechanism in each bridge, i.e. bridges with yielding piers of the column type and bridges with bearings (with or without seismic links) and non-yielding piers of the wall type. The activation of the abutment-backfill system due to closure of the gap between the deck and the abutments is also taken into account. The derived fragility curves are subjected to a first calibration against empirical curves based on damage data from the US and Japan.  相似文献   

人类活动胁迫下岩溶含水层脆弱性分析   总被引：3，自引：0，他引：3  

路洪海 《热带地理》2004,24(3):212-215

从水文地质本身的内部要素分析岩溶含水层高度脆弱的原因,详细论述了农业活动、工业和城市化以及矿山开采等对岩溶含水层脆弱性的影响,认为人类活动的叠加无疑加剧了岩溶含水层的脆弱性,并在很大程度上影响着地下水的水质、水量.因此,合理规范人类活动,减少人类活动对环境的污染,是岩溶地下水资源可持续利用的保证.  相似文献   

GNSS安全——网络空间安全的新战场          下载免费PDF全文

刘畅  丁凡  田淼清 《全球定位系统》2019,44(1):48-53

网络安全是当代网络社会面临的重要问题.全球卫星导航系统(GNSS)是网络空间的重要组成部分,GNSS提供的时空信息不仅是万物互联实现所需的时空参考基准,其本身也是网络传输的重要数据内容之一.易损性是引起GNSS安全性风险的重要因素,GNSS受干扰影响可失去定位授时能力或产生虚假信息,造成GNSS安全性风险并进而影响整个网络空间的安全.应从思想认识,系统建设,技术发展,法律法规等方面入手应对GNSS造成的网络安全性风险.  相似文献   

Use of alternative conceptual models to assess the impact of a buried valley on groundwater vulnerability   总被引：2，自引：1，他引：1  

Dorte Seifert  Torben O. Sonnenborg  Peter Scharling  Klaus Hinsby 《Hydrogeology Journal》2008,16(4):659-674

A buried valley incised into a sequence of pre-Quaternary sediments is shown to seriously affect the vulnerability of groundwater. Often the existence of buried valleys is not known or is not described explicitly in a hydrogeological model. In the present study, two numerical groundwater models, representing two alternative conceptual models, were produced to help quantify the effect of the valley on groundwater vulnerability. One model included the buried valley and the other did not. Both models were subjected to calibration and were found to describe hydraulic head and river discharge equally well. Even though the two models showed similar calibration statistics; fluxes, travel paths and travel times were affected by the inclusion of the buried valley. The recharge area and the groundwater age of potential abstraction wells placed in the pre-Quaternary deep aquifers surrounding the buried valley were different for the two models, with significantly higher vulnerability when the valley was included in the model. Based on the results of the present study, it is concluded that a buried valley may not always be detectable when calibrating a wrong conceptual model. If reliable results should be obtained a good geological model has to be constructed.  相似文献   

Flood risk management in Central Viet Nam: challenges and potentials     

Phong Tran  Fausto Marincioni  Rajib Shaw  Massimo Sarti  Le Van An 《Natural Hazards》2008,46(1):119-138

This article explores the impacts of floods on the economy, environment, and society and tries to clarify the rural community’s coping mechanism to flood disasters in Central Viet Nam. It focuses on the social aspects of flood risk perception that shapes the responses to floods. The research findings revealed that flooding is an essential element for a coastal population, whose livelihood depend on productive functions of cyclical floods. The findings also revealed that floods, causing losses and damages, often inhibited economic development. The surveyed communities appeared to have evolved coping mechanisms to reduce the negative impacts of the floods, yet these coping mechanisms are under pressure due to environmental degradation. Integrated flood risk management is considered as a suitable paradigm for coping with flood disasters.

Phong TranEmail:

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Too hot to handle: Depoliticisation and the discourse of ecological modernisation in fire management debates     

《Geoforum》2016

The management of fire within landscapes is a topic of increasing contestation. This is particularly the case in relation to the practice of ‘prescribed burning’, which aims to exercise a form of control of wild fires through the application of science-based techniques that putatively reconcile the conservation of biodiversity with the protection of human life and property in particular places. The belief in possibilities to solve environmental problems by scientific approaches and in outcomes that do not involve harm or vulnerabilities is an element of a trend called “Ecological Modernisation” (EM). Various studies have shown how discourses of EM have come to dominate the ways in which many contemporary environmental problems are approached. We argue that highlighting the presentation of such discourses as neutral and non-politicised precludes a critical examination of the ways in which the knowledge claims upon which they rest can be seen to reinforce only particular sets of constructions of the relationship between humans and the natural world. Through an analysis of knowledge claims made in relation to recurring topics such as the use of fire by Indigenous Australians and the adaptation of species to fire, we illustrate that behind the discourse of ecological modernisation sit deeply engrained variations in terms of where people locate vulnerability in relation to the pressing problem of wildfire and fire management. We argue that the depoliticisation of the topic sustains specific types of relationships between people and nature while delegitimising others and obscures the fundamentally different notions about relationships between humans and non-human nature upon which the debate ultimately pivots.  相似文献   

A social justice framing of climate change discourse and policy: Adaptation,resilience and vulnerability in a Jamaican agricultural landscape     

《Geoforum》2016

It is now widely recognized that climate change is likely to have detrimental impacts across the Caribbean region, with the burden likely to fall disproportionately on the most vulnerable segments of society. It is therefore an appropriate time to ask whether the frameworks that lie behind climate change discourse and policy are consistent with the demands of social and environmental justice. In this paper, we use climate justice as a lens for evaluating three prominent frameworks for addressing climate change, those of adaptation, resilience, and vulnerability. Each of these discursive frameworks, we argue, can contribute to our understanding of climate change, but they do not all incorporate justice concerns to the same degree. In order to illustrate this, we examine the justice implications of using each of the three frameworks to assess a case study of agricultural transformation in Southwestern Jamaica. Farmers in this region have adapted to changing climate conditions in a variety of ways, including the use of new agricultural technology. The ability of many farmers to take advantage of such innovations, however, is constrained by the underlying landscape of vulnerability within the region. After interpreting this example from the perspectives of adaptation, resilience and vulnerability, we conclude that all three paradigms are capable of calling attention to climate justice issues, but only in the vulnerability perspective are such issues intrinsic. We believe, therefore, that a greater attention to vulnerability within Caribbean climate policy holds the potential to advance the goals of climate justice within the region.  相似文献   

Means,meanings, and contexts: A framework for integrating detailed ethnographic data into assessments of fishing community vulnerability     

《Marine Policy》2016

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Maladaptive outcomes of climate insurance in agriculture     

《Global Environmental Change》2017

Agricultural insurance programs are currently being championed by international donors in many developing countries. They are acclaimed as promising instruments for coping with climate risk. However, research on their impacts has mainly focused on economic considerations. Studies on broader social and ecological consequences are sparse and have produced ambiguous and inconclusive results. We address this knowledge deficit by (a) advocating for a holistic view of social-ecological systems and vulnerability when considering insurance impacts; (b) offering a systematic overview highlighting the potential beneficial and adverse effects of ‘climate insurance’ in agriculture, particularly where programs target intensifying agricultural production; and (c) suggesting preliminary principles for avoiding maladaptive outcomes, including specific recommendations for designing appropriate impact studies and insurance programs. Our synopsis brings together scientific knowledge generated in both developing and developed countries, demonstrating that agricultural insurance programs shape land-use decisions and may generate serious economic, social, and ecological consequences. If insurance is to be an appropriate tool for mitigating the impacts of climate change, it needs to be carefully developed with specific local social-ecological contexts and existing risk coping strategies in mind. Otherwise, it is liable to create long-term maladaptive outcomes and undermine the ability of these systems to reduce vulnerability.  相似文献   

Operationalizing longitudinal approaches to climate change vulnerability assessment     

《Global Environmental Change》2017

The past decade has seen a proliferation of community-scale climate change vulnerability assessments globally. Much of this work has employed frameworks informed by scholarship in the vulnerability field, which draws upon interviews with community members to identify and characterize climatic risks and adaptive responses. This scholarship has developed a baseline understanding of vulnerability in specific places and industries at particular times. However, given the dynamic nature of vulnerability new methodologies are needed to generate insights on how climate change is experienced and responded to over time. Longitudinal approaches have long been used in sociology and the health sciences to capture the dynamism of human processes, but their penetration into vulnerability research has been limited. In this article, we describe the application of two longitudinal approaches, cohort and trend studies, in climate change vulnerability assessment by analyzing three case studies from the Arctic where the authors applied these approaches. These case studies highlight how longitudinal approaches can be operationalized to capture the dynamism of vulnerability by identifying climate anomalies and trends, and how adaptations develop over time, including insights on themes such as social learning and adaptive pathways.  相似文献