Multi Hazard Research Articles

Multi hazard vulnerability analysis: The casualty model and its implementation

The frequent occurrence of damaging natural and technological hazards clearly demonstrates the urgent need of study of multi-hazards vulnerability assessment methods to effectively reduce the impact of multi hazards in the built envirenment. This study presents the Multi Hazard Casualty Model (MHCM). Two types of hazards will be assessed, namely earthquake and fire following earthquake. Our objective in this paper is to present the casualty model, to analyse the applicability of casualty model for the assessment of multi-hazards vulnerability of building and human with a GIS-based Analysis. Methods used in this paper are based on theoretical approach and documentation. The approach used for casualty model is based on semi-quantitative and quantitative analysis. The analytical vulnerability model use building damage and consequential triggering hazard (e. g. fire) for the evaluation of human casualties. An attempt to develop casualty model based on interactions among hazards and/or domino effects. To this task is to correlate second hazard casualties directly with triggering hazard. The focus is on indicating hazard relations to understand how potential hazards of various degrees and magnitudes might result in MHCM. It incorporated considerations for multiple and cumulative hazards occurrences into the overall assessment framework and methodology. Triggering (domino) effects, and building vulnerability are two major factors that can lead to effected casualties in MHCM. The model is implicated with data collected in a part of Shiraz City. The casualty model shows that structural failure is the primary cause of earthquake built environment casualties and that physical damage potential should be the foundation of estimation fire followind earthquake casualty. Other factors should also be integrated. In the present study has been done to present the casualty model and to analyse the applicability of casualty model for the assessment of multi-hazards vulnerability of building and human.

Multi-hazard risk assessment of highway bridges subjected to earthquake and hurricane hazards

This paper presents a Parameterized Fragility based Multi Hazard Risk Assessment (PF-MHRA) procedure risk for assessment of a portfolio of highway bridges subjected to earthquake and hurricane events. As a part of this approach, parametric bridge fragility functions are generated for the two hazards, which are an advance over conventional fragility curves as they can be used for bridges with different geometric and structural properties given exposure to different hazard types. The parametric bridge fragility functions are derived using metamodels and stepwise logistic regression with a non-linear logit function. The relative change in hurricane and earthquake fragilities of the bridges is captured by the parametric fragility functions given variation in design details or geometric parameters of the bridges. These fragility functions are combined with regional hazard data to evaluate annual risk, which is measured as the annual probability of damage. For this purpose, hazard input parameters are identified for earthquakes and hurricane events and a new risk assessment procedure for bridges subjected to hurricane wave and surge loading is also developed. Furthermore, coupling of the risk assessment procedure with parameterized fragilities enables a comparative assessment of the contributions of different hazards to the total risk as the bridge details differ in a portfolio. The proposed framework is applied to multi-span simply supported concrete girder bridges located in South Carolina. The application demonstrates the identification and derivation of input models for the multi-hazard risk assessment for earthquakes and hurricane induced storm surge and wave loading. By applying the proposed method, insights are gained on the influence of different bridge geometries and hazard exposure conditions to the risk of bridge damage. The potential of the proposed procedure to serve as an aid to risk based design of bridges is also highlighted.

Multi Hazard Scenarios in the Mendoza/San Juan Provinces, Cuyo Region Argentina

This paper exposes major natural hazards inventory encountered in the two San Juan and Mendoza provinces, such as climatic, seismic, gravitational, and social/anthropic ones. The contrast between the high altitude of the region and low one is addressed in order to manage the inhomogeneity of prevention plans. The international road to Chile is greatly affected by gravitational hazards that proceed in out of run period and commercial traffic interruption, and large economic waste more than people vulnerability, as the urban areas are more affected by seismicity scenarios. But as gravitational hazard is affected by the seismicity it is proposed to analyze some co-hazard effect in a multi-scenarios approach from geology geography and mechanical modelling of events to explore the co-effects on the scenarios. Moreover, some similarities with the Rhone-Alpes region of France are evocated and may be of interest.

Probabilistic Assessment of Earthquake Damage and Loss for the City of Tehran, Iran

Article history: Received: 16 February 2013 Accepted: 30 May 2013 Tehran is one of the densely populated metropolises located in earthquake-prone regions. Tehran, the population of which surpasses 8 million people, is the most populated area in Iran. There are historical evidences confirming that catastrophic earthquakes have destroyed the city in past years. In the present paper, our study covers all parts of Tehran because there is the potential of significant earthquake damage and loss for the entire city. In other words, the development of high-rise building construction in the northern part, the high density of population in the southern area including old masonry buildings, and the existence of important structures in central regions, prevent us from omitting any particular part of the city from damage assessment process. We have used two sets of last available formal data published in 1996 and 2006. To consider the influence of soil conditions, Tehran has been divided into 1246 sub regions; however, in our study the results have been presented using municipality regions and in cumulative manner. Since there is no acceptable statistical data involving estimation of non-structural damage, only structural damages have been assessed. The open source software SELENA is applied to perform probabilistic loss estimates. Due to the lack of studies providing required information from structural point of view in our country, and the existence of similarity between structural codes of Iran and that of United States, HAZUS-MH (Hazard Us – Multi Hazard Loss) structures coefficients are used. According to the results, from 1996 to 2006, the mean damage ratio and number of casualties have been reduced, while the economic loss has been increased.

Multi-Stage Performance of Seismically Isolated Bridge Using Triple Pendulum Bearings

Triple pendulum isolator (TPI) represent a new generation of adaptive friction isolation system to control super-structure demand in different hazard levels. This isolator incorporates four concave surfaces and three independent pendulum mechanisms. Pendulum stages can be set to address specific response criteria for moderate, severe and very severe events. Herein after mathematical formulation of typical elevated highway bridge using TPI, series of nonlinear dynamic analysis were performed with different friction coefficients, pendulum radius and slider displacement capacities. Effects of variation of these parameters were investigated on key bridge demand parameters under multi hazard level excitations by using probabilistic description.

Towards an Integrated Information Logistics for Multi Hazard Early Warning Systems

The delivery of user-tailored warning messages for heterogeneous user groups is a challenge rarely covered by hazard monitoring and Early Warning Systems (EWS) even though it is one of the four key elements of early warning systems identified by the United Nations International Strategy for Disaster Reduction (UN/ISDR). This article describes the concepts of generic information logistics developed for the distant early warning system (DEWS). It is not limited to specific hazard types, languages or other deployment specifics. Instead, it enables the generation of user-tailored warning messages that account for specific needs, individual requirements, different levels of understanding, distinct perceptions and varying personal abilities and it provides several filter mechanisms to avoid unintentional message flooding in emergency situations. This novel approach is completed by a reusable graphical user interface component, which provides functionality to generate warning messages in compliance with the Common Alerting Protocol (CAP) standard to leverage inter-operability among early warning systems.

Risk Based Decision Making for Bridge under Multi Hazard

The bridges are of much importance to the transportation network system, as they connect key highways at crucial nodes. This paper reviews and discussed risk-based methodologies to assess the risk acceptability and cost-effectiveness of protective measures for bridge under multiple manmade or natural hazards. Three risk acceptance criteria based on fatality risks, failure probabilities and net benefit assessment were described and discussed. The decision support framework accompanying these risk acceptance criteria considers hazard probabilities, value of human life, physical and indirect damages, risk reduction and protective measure costs were studied and an illustrative example was presented.

Theory and Practice in Reducing the Vulnerability of Residential Buildings Subjected to Extreme Loads - a Multi Hazard Perspective

The spread of terror and war threats aimed against built up urban areas has extended considerably and attracts the attention and concern of many countries. The severity and potential danger of these extreme events was demonstrated most severely in several past events. Many countries, including Israel, are facing different threats of terror and war. Therefore, Israel is continuously engaged in theoretical and experimental research activities, related to response of civilian buildings to various war threats. Some of the experience gained in recent years, in relation to the structural response of RC residential buildings subjected to blast loads, can be very helpful in the development of improved design requirements of such buildings, aimed mainly at localization and reduction of the damage and prevention of the progressive collapse of buildings. Earthquake loading is another extreme loading that may cause large scale destruction to many buildings that had not been properly designed to withstand the strong ground shaking effects. Many countries in seismic areas have developed throughout the years their standards and codes for seismic design, and recently built buildings in these areas are designed according to these codes. Nevertheless, many older buildings, that had been designed and constructed prior to the development of the modern seismic codes, are still more vulnerable. Although the earthquake response and blast protection are entirely different disciplines, there exist many places where both types of extreme loads are potential threats to existing buildings. Therefore a multi hazard approach should be adopted to design the new buildings and to retrofit the existing buildings, to ensure that they will withstand these threats. This paper aims at over-viewing some aspects of these extreme load threats and address the resistance, performance, protection and strengthening of the structures that are subjected to these loads. It aims at generalizing the professional view and providing a better solution to an envelope of different possible extreme events.

Update on Government Relations Activities through December 2009

The Seismological Society of America and its Government Relations Committee has been very active in Washington, DC, over the past several months, raising the profile of the SSA and calling attention to the importance and need for earthquake science research and outreach. In July, SSA co-sponsored a congressional briefing on the Great Southern California ShakeOut 2008. The panelists were Lucile Jones, chief scientist, Multi Hazards Project, U.S. Geological Survey; Gary Sturdivan, Emergency Manager, East Valley Water District, San Bernardino, California; and Steven Sellers, Assistant Secretary for Prevention, Operations and Recovery, California Emergency Management Agency (CalEMA). They highlighted the science behind the ShakeOut and the implementation of lessons learned from the ShakeOut to strengthen infrastructure and improve emergency response. Some of the keys to success included a broad-based outreach program, media engagement, and public advocacy by hundreds of partners. A comprehensive science-based earthquake scenario helped make the hazard real to people, and communication approaches that applied decades of social science research helped get people to be better prepared. The panel also focused on the interdependency of utilities and infrastructure resilience and the tangential losses to the nation that would be associated with California being offline following a large earthquake in Southern California. Dr. Jones also commented on the success of the 2008 event and her hopes for even bigger events in 2009 and 2010. The event was well attended by congressional staff from the House, Senate, and select committees, as well as interested members from the seismic community. Feedback from the …

Urban Seismic Risk Evaluation: A Holistic Approach

Risk has been defined, for management purposes, as the potential economic, social and environmental consequences of hazardous events that may occur in a specified period of time. However, in the past, the concept of risk has been defined in a fragmentary way in many cases, according to each scientific discipline involved in its appraisal. From the perspective of this article, risk requires a multidisciplinary evaluation that takes into account not only the expected physical damage, the number and type of casualties or economic losses, but also the conditions related to social fragility and lack of resilience conditions, which favour the second order effects (indirect effects) when a hazard event strikes an urban centre. The proposed general method of urban risk evaluation is multi hazard and holistic, that is, an integrated and comprehensive approach to guide decision-making. The evaluation of the potential physical damage (hard approach) as the result of the convolution of hazard and physical vulnerability of buildings and infrastructure is the first step of this method. Subsequently, a set of social context conditions that aggravate the physical effects are also considered (soft approach). In the method here proposed, the holistic risk evaluation is based on urban risk indicators. According to this procedure, a physical risk index is obtained, for each unit of analysis, from existing loss scenarios, whereas the total risk index is obtained by factoring the former index by an impact factor or aggravating coefficient, based on variables associated with the socio-economic conditions of each unit of analysis. Finally, the proposed method is applied in its single hazard form to the holistic seismic risk evaluation for the cities of Bogota (Colombia) and Barcelona (Spain).

Roadblocks to return to work after electrical trauma

Electrical trauma in the US is the fifth leading cause of death on the job [2]; during 1992–1998, data show 2,268 fatal electrical injuries [13]. In the same period, 32,309 non-fatal lost time electrical injuries were recorded by the US Bureau of Labor Statistics [9]. The complexity in patients’ clinical presentation reflects the fundamental nature of electrical injury events: these are typically high speed, multi hazard incidents [10– 12]. The clinical spectrum of electrical injury ranges from the absence of any external physical signs to severe multiple trauma requiring extensive surgical care [4,8]. Peripheral nerve disorders as described by Wilbourn [16] can complicate rehabilitation, in addition to traumatic sequella. Research suggests electrical trauma survival can be associated with significant functional impairment. In their landmark retrospective study of employees of a national electrical energy company, Gourbiere et al. reviewed the electrical trauma survival experience during 1970–1989 for a workforce between 100,000–120,000. Electrical burns affected 2080 workers. Of these, 515 patients or 25% were noted to have post-injury complications, including: 63% burn related, with amputations in 5%; 18% neuropsychiatric; 12% sensory; 5% orthopedic; and 1% cardiovascular. Sense organ disorders included vision related changes due to conjunctivitis, keratitis, and cataracts; auditory sequella, with conductive or sensorineural hearing loss, tinnitus, and vertigo; and anosmia. In 59 of the 515 patients, disability was considered serious, with impairment rating from 31–100% [7]. Return to work success of electrical trauma patients is variable, as suggested in the report by Pliskin et al. [14]. In this series study, all patients had peripheral electrical contacts, with no evidence on history or examination of direct mechanical electrical contact with the head. (Facial injuries from electrical arc flash burns were not a basis for excluding a patient for this series study. However, two patients were excluded: one patient was excluded based on his report of repeated stray voltage exposure which could not be verified. A second patient was excluded because of a high suspicion of malingering.) A total 45 males and 8 females were included in the final analysis. These individuals had a mean age of 38.5 years (+ 11.0; 22 to 70) and a mean educational level of 13.1 years (+1.9; 8–18). Twentyone of the 53 patients were injured by voltage sources less than 1000 V (39.6%) and 27 patients sustained voltage exposures greater than 1000 V (50.9%). Fortyfour patients were hospitalized for observation or to receive initial treatment for their injuries (83.0%), while 9 patients were released after initial evaluation. Twenty patients underwent surgery for their injuries (37.7%), 32 patients received either non-surgical treatment or no treatment, and the treatment history for 1 patient was unknown. Sixteen of the 53 patients sustained a loss of consciousness as a result of their electrical accident (30.2%) and 4 patients experienced cardiac arrest (7.5%). Twenty of the 53 patients were employed as electricians or line operators at the time of injury.