Temporal vulnerability in hazardscapes: Flood memory-networks and referentiality along the North Carolina Neuse River (USA)     

Daniel H. de Vries   《Global Environmental Change》2011,21(1):154-164

Social models of population vulnerability to disasters increasingly include the notion that vulnerability has a strong temporal component. While this temporality is typically conceptualized as objective (making vulnerability “dynamic,” “multiscalar,” and/or “historical”), it consistently fails to acknowledge that among stakeholders managing hazardscapes temporality is also a social process in which subjective experience of time may play a role in creating situations of population vulnerability. This paper proposes that the temporal situatedness of a population relative to past hazard events and the quality with which stakeholders engage hazard memory-chains combine to significantly influences its vulnerability to natural hazards. It is proposed that this temporal vulnerability is characterized by shared, population level potential for surprise and can be evaluated by exploration of time-series depth and temporal reference points in historical ecological narratives and documents. Based on ethnohistoric research conducted from 2002 to 2006 in flood-prone eastern North Carolina (USA), it is illustrated how temporal vulnerability was relatively higher in the Neuse River watershed located at the City of Kinston than surrounding watersheds. Due to the combination of factors including the damming of the Neuse River in the 1980s, outdated official floodplain maps, relatively unmonitored floodplain development, the stochastic timing of flood events (placing the last major flood more than a generation away), technological optimism, and turnover of floodplain officials and residents, local stakeholders were seriously misinformed about the space-time risks involved both before and after the disaster of Hurricane Floyd (1999) happened. To deal with this inconsistency, the temporal rarity of Hurricane Floyd as a “500-year event” has been motivated and embraced by many in an effort to continue life-as-is. The paper proposes that the concept of temporal vulnerability is further explored and used as key dimension in the vulnerability sciences.  相似文献   

Systems for Hazards Identification in High Mountain Areas： An Example from the Kullu District, Western Himalaya   总被引：2，自引：1，他引：1  

JamesS.Gardner EricSaczuk 《山地科学学报》2004,1(2):115-127

Methods and techniques for the identification, monitoring and management of natural hazards in high mountain areas are enumerated and described. A case study from the western Himalayan Kullu District in Himachal Pradesh, India is used to illustrate some of the methods. Research on the general topic has been conducted over three decades and that in the Kullu District has been carried out since 1994. Early methods of hazards identification in high mountain areas involved intensive and lengthy fieldwork and mapping with primary reliance on interpretation of landforms, sediments and vegetation thought to be indicative of slope fail ures, rock falls, debris flows, floods and accelerated soil surface erosion. Augmented by the use of airphotos and ad hoc observations of specific events over time, these methods resulted in the gradual accumulation of information on hazardous sites and the beginnings of a chronology of occurrences in an area. The use of historical methods applied to written and photographic material, often held in archives and libraries, further improved the resolution of hazards information. In the past two decades, both the need for, and the ability to, accurately identify potential hazards have increased. The need for accurate information and monitoring comes about as a result of rapid growth in population, settlements, transportation infrastructure and intensified land uses and, therefore, risk and vulnerability in mountain areas. Ability has improved as the traditional methods of gathering and manipulating data have been supplemented by the use of remotesensing, automated terrain modeling, global positioning systems and geographical information systems. This paper focuses on the development and application of the latter methods and techniques to characterize and monitor hazards in high mountain areas.  相似文献   

People and community as constituent parts of hazards: the significance of societal dimensions in hazards analysis     

C. Emdad Haque  David Etkin 《Natural Hazards》2007,41(2):271-282

Nature-triggered hazards and disasters have traditionally been treated only from the lens of geophysical and biophysical processes, implying that the root cause of large-scale death and destruction lies in the natural domain rather than in a coupled human–environment system. Conceptually, the physical domain has been seen as discrete and separate from human entities, and solutions were sought in the technological intervention and control of the physical environment—solutions that often ended up being less effective than hoped for and sometimes even counter productive. At all levels, institutions have directed and redirected most of their financial and logistical resources into the search for scientific and engineering solutions without allocating due attention and resources towards the assessment of effects and effectiveness of the applications of such technological outcomes. However, over the last two decades, forceful criticisms of the ‘dominant’ technocratic approach to hazards analysis have appeared in the literature and consequently there has not only been a shift in thinking of causation of disaster loss in terms of human vulnerability, but also newer questions have arisen regarding distinguishing between the ‘physical exposure’ of people to threats and societal vulnerability, and linking them with propensity to hazards loss. Though the vulnerability/resilience paradigm has largely replaced the hazards paradigm within the social sciences and much of the professional emergency and disaster management communities, this shift of thinking has not progressed to much of the physical science community, decision-makers and the public, who have not yet accepted the idea that understanding and using human and societal dimensions is equally or more important than trying to deal and control nature through the use of technology. This special issue is intended to further the idea that the aspects of community and peoples’ power to mitigate, to improve coping mechanisms, to respond effectively, and recover with vigor against the environmental extremes are of paramount conceptual and policy importance.  相似文献   

Time-clustering of natural hazards   总被引：1，自引：0，他引：1  

Luciano Telesca 《Natural Hazards》2007,40(3):593-601

Natural hazards can be represented as point processes that are characterized by the occurrence times of the events and their intensities. It is crucial to investigate the correlation properties of these processes in order to gain a deep knowledge of the dynamical mechanisms which underlie hazardous phenomena. To this end, suitable methodologies must be developed to perform these correlation analyses on processes, which are described as point-like processes. The concept of time-clustering implies a time-structured organization of these processes, and is in direct opposition to the pure randomness typical of Poissonian processes in which the events are uncorrelated. This article reports several examples of natural hazards within the framework of time-clustering.  相似文献   

Electrification of volcanic plumes     

T. A. Mather  R. G. Harrison 《Surveys in Geophysics》2006,27(4):387-432

Volcanic lightning, perhaps the most spectacular consequence of the electrification of volcanic plumes, has been implicated in the origin of life on Earth, and may also exist in other planetary atmospheres. Recent years have seen volcanic lightning detection used as part of a portfolio of developing techniques to monitor volcanic eruptions. Remote sensing measurement techniques have been used to monitor volcanic lightning, but surface observations of the atmospheric electric Potential Gradient (PG) and the charge carried on volcanic ash also show that many volcanic plumes, whilst not sufficiently electrified to produce lightning, have detectable electrification exceeding that of their surrounding environment. Electrification has only been observed associated with ash-rich explosive plumes, but there is little evidence that the composition of the ash is critical to its occurrence. Different conceptual theories for charge generation and separation in volcanic plumes have been developed to explain the disparate observations obtained, but the ash fragmentation mechanism appears to be a key parameter. It is unclear which mechanisms or combinations of electrification mechanisms dominate in different circumstances. Electrostatic forces play an important role in modulating the dry fall-out of ash from a volcanic plume. Beyond the local electrification of plumes, the higher stratospheric particle concentrations following a large explosive eruption may affect the global atmospheric electrical circuit. It is possible that this might present another, if minor, way by which large volcanic eruptions affect global climate. The direct hazard of volcanic lightning to communities is generally low compared to other aspects of volcanic activity.  相似文献   

滚石灾害防治方法浅析   总被引：2，自引：0，他引：2  

张中俭  张路青 《工程地质学报》2007,15(5):712-717

随着人类活动的广度和力度不断加大,多山地带的滚石问题越来越突出,致使有关滚石灾害及其防治方法的研究也逐步得到重视。总体而言,滚石灾害的防治方法可分为主动防护和被动防护两大类,可应用于不同的滚石灾害环境。对各类滚石灾害防治方法进行简单介绍之后,作者分析了各方法的应用范围和适用条件。  相似文献   

Oil-spill disasters and the rural hazardscape of Eastern Nigeria     

Innocent M. Aprioku 《Geoforum》2003,34(1):99-112

The objective of the paper is to investigate the links between the patterns of incidents, the amount of hazardous materials locally present and capability of local emergency preparedness in rural local government councils. Four states Abia, Akwa Ibom, Bayelsa and Rivers State were used to examine the nature and pattern of oil-spill disasters in rural Nigeria. It is argued that oil-spill hazards are more than isolated engineering malfunctions. They can be alternatively understood as reflections of the social, economic and political contexts in which they occur. Discriminant analysis is used to examine the relationship between 71 country risk-related and preparedness variables and incident frequency. The findings illustrate the usefulness of contextual analysis in examining the restructuring of rural life and the capacity of fiscally and socially stressed rural communities to respond to environmental change.  相似文献   

Prediction of tension crack location and riverbank erosion hazards along destabilized channels     

Stephen E. Darby  Colin R. Thorne 《地球表面变化过程与地形》1994,19(3):233-245

Riverbank erosion, associated sedimentation and land loss hazards are a land management problem of global significance and many attempts to predict the onset of riverbank instability have been made. Recently, Osman and Thorne (1988) have presented a Culmann-type analysis of the stability of steep, cohesive riverbanks; this has the potential to be a considerable improvement over previous bank stability theories, which do not account for bank geometry changes due to toe scour and lateral erosion. However, in this paper it is shown that the existing Osman-Thorne model does not properly incorporate the influence of tension cracking on bank stability since the location of the tension crack on the floodplain is indirectly determined via calculation or arbitrary specification of the tension crack depth. Furthermore, accurate determination of tension crack location is essential to the calculation of the geometry of riverbank failure blocks and hence prediction of land loss and bank sediment yield associated with riverbank instability and channel widening. In this paper, a rational, physically based method to predict the location of tension cracks on the floodplain behind the eroding bank face is presented and tested. A case study is used to illustrate the computational procedure required to apply the model. Improved estimates of failure block geometry using the new method may potentially be applied to improve predictions of bank retreat and floodplain land loss along river channels destabilized as a result of environmental change.  相似文献   

Development of site-specific design ground motions in Western and Eastern North America     

Walter Silva  Carl Costantino   《Soil Dynamics and Earthquake Engineering》2002,22(9-12):755-764

This paper presents results recently obtained for generating site-specific ground motions needed for design of critical facilities. The general approach followed in developing these ground motions using either deterministic or probabilistic criteria is specification of motions for rock outcrop or very firm soil conditions followed by adjustments for site-specific conditions. Central issues in this process include development of appropriate attenuation relations and their uncertainties, differences in expected motions between Western and Eastern North America, and incorporation of site-specific adjustments that maintain the same hazard level as the control motions, while incorporating uncertainties in local dynamic material properties. For tectonically active regions, such as the Western United States (WUS), sufficient strong motion data exist to constrain empirical attenuation relations for M up to about 7 and for distances greater than about 10–15 km. Motions for larger magnitudes and closer distances are largely driven by extrapolations of empirical relations and uncertainties need to be substantially increased for these cases.

For the Eastern United States (CEUS), due to the paucity of strong motion data for cratonic regions worldwide, estimation of strong ground motions for engineering design is based entirely on calibrated models. The models are usually calibrated and validated in the WUS where sufficient strong motion data are available and then recalibrated for applications to the CEUS. Recalibration generally entails revising parameters based on available CEUS ground motion data as well as indirect inferences through intensity observations. Known differences in model parameters such as crustal structure between WUS and CEUS are generally accommodated as well. These procedures are examined and discussed.  相似文献   

Estimating silicic lava vesicularity with thermal remote sensing: a new technique for volcanic mapping and monitoring   总被引：2，自引：0，他引：2  

Michael S. Ramsey  Jonathan H. Fink 《Bulletin of Volcanology》1999,61(1-2):32-39

 Remote monitoring of active lava domes provides insights into the duration of continued lava extrusion and detection of potentially associated explosive activity. On inactive flows, variations in surface texture ranging from dense glass to highly vesicular pumice can be related to emplacement time, volatile content, and internal structure. Pumiceous surface textures also produce changes in thermal emission spectra that are clearly distinguishable using remote sensing. Spectrally, the textures describe a continuum consisting of two pure end members, obsidian and vesicles. The distinct spectral features of obsidian are commonly muted in pumice due to overprinting by the vesicles, which mimic spectrally neutral blackbody emitters. Assuming that this energy combines linearly in direct proportion to the percentage of vesicles, the surface vesicularity can be estimated by modeling the pumice spectrum as a linear combination of the glass and blackbody spectra. Based on this discovery, a linear retrieval model using a least-squares fitting approach was applied to airborne thermal infrared data of the Little Glass Mountain and Crater Glass rhyolite flows at Medicine Lake Volcano (California) as a case study. The model produced a vesicularity image of the flow with values from 0 to ∼70%, which can be grouped into three broad textural classes: dense obsidian, finely vesicular pumice, and coarsely vesicular pumice. Values extracted from the image compare well with those derived from SEM analysis of collected samples as well as with previously reported results. This technique provides the means to accurately map the areal distributions of these textures, resulting in significantly different values from those derived using aerial photographs. If applied to actively deforming domes, this technique will provide volcanologists with an opportunity to monitor dome-wide degassing and eruptive potential in near-real-time. In July 1999 such an effort will be possible for the first time when repetitive, global, multispectral thermal infrared data become available with the launch of the Advanced Spaceborne Thermal Emission and Reflectance Radiometer (ASTER) instrument aboard the Earth Observing System satellite. Received: 25 June 1998 / Accepted: 14 December 1998  相似文献