Earthquake Casualties 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.

Earthquake Damage Forms of Multi-Story Brick Masonry Structure and their Mechanical Analysis

In order to know seismic damage characteristics of multi-story brick masonry structure and improve its seismic capability, five kinds of earthquake damage or collapse forms of multi-story masonry brick structure are summed up based on earthquake disaster survey, each of which is analyzed with mechanics. And the failure mechanism of each seismic damage form of multi-story brick masonry structure are proposed, which provides effective engineering experience for the seismic or anti-collapse design of multi-story masonry brick structure. The research has the important significance in improving the seismic capacity of multi-story brick masonry structure and reducing the earthquake casualties.

Application and prospect of a high-resolution remote sensing and geo-information system in estimating earthquake casualties

Abstract. An accurate estimation of a casualty rate is critical in response to earthquake disasters, and could allow an increase in the survival rate. Building damage is considered to be a major cause of earthquake casualties in developing countries. High-resolution satellite imagery (HRSI) can be used to detect the building damage in a period of a short time. This makes it possible to use a model to estimate earthquake casualties immediately after the occurrence of an earthquake. With respect to the capability of HRSI, this study built a new model for estimating the casualty rate in an earthquake disaster based on remote sensing and a geographical information system. Three groups of earthquake data, the 2003 Bam earthquake, the 2008 Wenchuan earthquake, and the 2010 Yushu earthquake, were used to evaluate this model. The results indicated that our new model significantly improved the accuracy in predicting the casualty rate. The parameters used in the model vary between developed and developing countries. This study could provide valuable information for a more efficient rescue operation in response to earthquakes.

Damage potential and vulnerability functions of strategic buildings in the city of Algiers

The estimation of losses resulting from an earthquake requires that for each building class, the relationship between the intensity of ground shaking and damage degree must be known or developed. Potential earthquake damage to structures, human beings and personal property have been the scope of numerous studies. Different approaches have been employed so far to estimate earthquake casualties and damage. This paper describe the basic concept for development of analytical vulnerability functions based essentially on so called damage model which was performed from probabilistic studies on seismic capacity of existing buildings in the city of Algiers (Algeria). Regarding the developed model for assessing the seismic damage, vulnerability functions of specific losses (potential losses for a specific urban area in terms of meter square area of building slabs which may involve causalities) were developed in order to predict the expected seismic risk for a given ground motion scenario.

Mathematical models for estimating earthquake casualties and damage cost through regression analysis using matrices

The aim of this study was to develop mathematical models for estimating earthquake casualties such as death, number of injured persons, affected families and total cost of damage. To quantify the direct damages from earthquakes to human beings and properties given the magnitude, intensity, depth of focus, location of epicentre and time duration, the regression models were made. The researchers formulated models through regression analysis using matrices and used α = 0.01.The study considered thirty destructive earthquakes that hit the Philippines from the inclusive years 1968 to 2012. Relevant data about these said earthquakes were obtained from Philippine Institute of Volcanology and Seismology. Data on damages and casualties were gathered from the records of National Disaster Risk Reduction and Management Council.The mathematical models made are as follows:This study will be of great value in emergency planning, initiating and updating programs for earthquake hazard reductionin the Philippines, which is an earthquake-prone country.

Selection and Prediction of Earthquake Casualties Related Factors Based on BP Neural Network Analysis

To reduce the prediction error rate of earthquake casualties, the paper proposed a prediction model with two steps: (1) screening of the earthquake casualties correlation factors; (2) improving the predictive veracity of general BP(Back Propagation) neural network model.By the analysis of 9 kinds of correlation factors, the paper established the MIV(Mean Impact Value) model based on BP neural network to screen the final correlation factors, and the paper got 6 main correlation factors according to the size of output weights of the factors. Finally, the paper verified the accuracy and practicability of the model through the validation of the model and the solving of prediction error of relevant factors hasn't been selected.

Modeling destructive earthquake casualties based on a comparative study for Turkey

The statistical modeling of destructive earthquakes is an indispensable tool for extracting information for prevention and risk reduction casualties after destructive earthquakes in a seismic region. The linear regression (LR) model can reveal the relation between casualty rate and related covariates based on earthquake catalog. However, if some covariates affect the casualty rate parametrically and some of them nonparametrically, the LR model may entail serious bias and loss of power when estimating or making inference about the effect of parameters. We suggest that semi-parametric beta regression (SBR), semi-parametric additive regression (SAR), and beta regression (BR) models could provide a more suitable description than the LR model to analyze the observed casualties after destructive earthquakes. We support this argument using destructive earthquakes occurred in Turkey between 1900 and 2012 having surface wave magnitudes five or more. The LR, SAR, BR, and SBR models are compared within the context of this data. The data strongly support that the SBR and SAR models can lead to more precise results than the BR and LR models. Furthermore, the SBR is the best model for the earthquake data since the beta distribution provides a flexible model that can be used to analyze the data involving proportions or rates. The results from this model suggest that the casualty rate depends on energy, damaged buildings, and the number of aftershocks of a destructive earthquake.

국가 지진재난 관리를 위한 시설물의 내진성능목표 설정방안

일반적으로 시설물의 내진성능목표는 시설물의 붕괴를 방지하여 인명피해를 최소화하는 것이다. 이러한 내진성능 덕분에 내진선진국은 과거 지진 시 인명피해를 최소화하였지만 시설물에 발생한 심대한 경제적 피해로 사회기능을 회복하는데 큰 어려움을 겪었다. 이를 계기로 현행 붕괴방지성능을 손상제어 성능으로 변경할 필요가 있음을 인식하기 시작하였다. 우리나라 시설물의 내진성능도 이와 동일하여 지진 시 큰 경제적 피해가 예상되며 이는 사회기능을 회복하는데 걸림돌이 된다. 국가차원에서 지진리스크를 관리하기 위해서는 지진피해는 관리 가능한 수준이어야 하며 시설물의 내진성능목표도 이에 부합되도록 설정되어야 한다. 본 연구에서는 국가내진성능목표를 설정하고 이에 부합되도록 시설물의 내진성능목표를 설정하는 방안 및 구체적 절차를 제안하였다. Generally, seismic performance objective of facilities is to minimize casualties by preventing collapse. Thanks to this performance the casualties in the past earthquakes were minimized in the advanced seismic engineering countries. However, they suffered from a great effort of recovering a social function because of heavy economical damage, which led a new seismic design paradigm to expand the current No-Collapse performance into Damage-controlled one. Because the seismic performance of our facilities is similar a severe damage will be led in earthquakes, which should be an obstacle in a rapid recovery of social system. The damage level should be restricted under a controlling level for a national earthquake-risk management and the performance of facilities should be assigned to meet this purpose. In this study the establishment scheme of seismic performance of facilities has been proposed to satisfy national seismic performance objective established in advance.

Estimation of earthquake casualties using high-resolution remote sensing: a case study of Dujiangyan city in the May 2008 Wenchuan earthquake

From a disaster relief perspective, an immediate and efficient rescue operation after an earthquake can greatly increase the number of survivors. An effective rescue operation depends on two key elements: localisation of the affected areas and estimation of the number of casualties in these areas. Many more studies have been conducted on the localisation of affected areas than on casualty estimation. Consequently, this study develops a model for rapidly estimating the number of casualties using satellite remote sensing (SRS). The model is based on the attributes of damaged buildings, as these buildings cause the greatest harm to inhabitants and they can be detected by SRS. The model uses the damage index (DI) of buildings computed by a numerical damage model derived from SRS images to assess the extent of damage. The DI is then combined with the building’s materials and structure index, which is calculated using information from the local geographic information system, to compute the joint casualty index (JCI). Finally, the number of casualties is estimated by the product of the JCI multiplied by the number of people inside the damaged buildings at the time of the earthquake. The model is then applied to three towns in Dujiangyan City, as these were the areas that most severely affected by the Wenchuan earthquake. Preliminary results showed that there was little difference between the actual and estimated number of casualties. It is recommended that more casualty data should be included in the model to improve the accuracy of estimation.

Estimating shaking-induced casualties and building damage for global earthquake events: a proposed modelling approach

Recent earthquakes such as the Haiti earthquake of 12 January 2010 and the Qinghai earthquake on 14 April 2010 have highlighted the importance of rapid estimation of casualties after the event for humanitarian response. Both of these events resulted in surprisingly high death tolls, casualties and survivors made homeless. In the Mw = 7.0 Haiti earthquake, over 200,000 people perished with more than 300,000 reported injuries and 2 million made homeless. The Mw = 6.9 earthquake in Qinghai resulted in over 2,000 deaths with a further 11,000 people with serious or moderate injuries and 100,000 people have been left homeless in this mountainous region of China. In such events relief efforts can be significantly benefitted by the availability of rapid estimation and mapping of expected casualties. This paper contributes to ongoing global efforts to estimate probable earthquake casualties very rapidly after an earthquake has taken place. The analysis uses the assembled empirical damage and casualty data in the Cambridge Earthquake Impacts Database (CEQID) and explores data by event and across events to test the relationships of building and fatality distributions to the main explanatory variables of building type, building damage level and earthquake intensity. The prototype global casualty estimation model described here uses a semi-empirical approach that estimates damage rates for different classes of buildings present in the local building stock, and then relates fatality rates to the damage rates of each class of buildings. This approach accounts for the effect of the very different types of buildings (by climatic zone, urban or rural location, culture, income level etc), on casualties. The resulting casualty parameters were tested against the overall casualty data from several historical earthquakes in CEQID; a reasonable fit was found.

Seismic retrofitting of non-engineered masonry in rural Nepal

One of the greatest causes of casualties in major earthquakes around the world is the collapse of non-engineered masonry buildings (those built without engineering input). Yet by definition non-engineered structures remain largely outside of the scope of modern engineering research, meaning that the majority of those at risk often remain so. A further barrier to realising research in this field is the significant social and economic challenge of implementation in low-income communities, where non-engineered housing is prevalent. This paper introduces a retrofitting technique aimed at preventing or prolonging the collapse of adobe (mud brick) houses under strong earthquakes. This technique uses common polypropylene packaging straps to form a mesh, which is then used to encase structural walls. The aim of this paper is to give an overview of the retrofitting technique's development and implementation. The key development stages of static, dynamic and numerical testing are presented, showing that the proposed technique effectively prevents brittle masonry collapse and the loss of debris. An implementation project is then discussed, involving a training programme for rural masons in Nepal, a public shake-table demonstration and the retrofit of a real house. The implementation project proved effective at reaching rural communities but highlighted that government subsidies are required to incentivise the safeguarding of homes among low-income communities.

Prediction of Seismic Casualties Based on Urban Land Types

A probability model based on urban land types and probability reliability was put forward to predict seismic casualties. The casualty probabilities of different urban land types were got by classifying the urban land types, combining with the historical earthquake casualty statistics and statistic residence status in the architecture of different urban land types, and then the upper value of earthquake casualties in certain probability might be estimated. Meanwhile, an example was analyzed with the proposed method. Results show the feasibility of the proposed method.

Case Study of Ground Fissures Generated by Liquefaction Following the Wenchan Earthquake

Ground failure caused by liquefaction is a major cause of earthquake damage and casualties during many history earthquakes. The gravels liquefaction extensively occurred following the 2008 Wenchuan Ms8.0 Earthquake, and 70-80% liquefied sites generated lots of 100 meter to hundreds kilometer long and 5 centimeter to 50 centimeter wide ground fissures, which intersected house, farmland, etc. and caused serous damage. The mechanism of the building damage and ground fissures were investigated by borehole drilling and Multi-Channels Electricity Resistance Test. The detailed in-situ tests and comparison show that: (1) The building, whose foundation intersected by liquefaction, suffered more severe damages than its surrounding buildings; (2) The abundant ground fissures were generated by gravels liquefaction rather than the raptures or secondary faults; (3)The fundamental conditions for the generation of ground fissures by liquefaction are: flat ground surface (slop less than 3%), horizontal non uniform distribution of liquefiable soils.

Probabilistic Seismic Hazard Assessment of India

Online material : Data files for seismogenic source zones (polygons), smoothed-gridded seismicity models, and hazard curves at 0.2° regular grid spacing over the study region. Earthquake disasters occur mainly due to the collapse of buildings and structures triggered by ground motions. It is, therefore, important to predict ground-shaking levels in order to determine appropriate building code provisions for earthquake-resistant design of structures. This involves extensive analyses and development of appropriate seismological models; namely, seismogenic sources, seismic site conditions, and ground motion predictions. The hazard products, viz . data and maps, constitute important tools for framing public policies toward land-use planning, building regulations, insurance, and emergency preparedness. View this table: Table 1 Major Earthquake Casualties during 1900–2008 in India and Adjoining Regions In India, several events during the last 100 years, as listed in Table 1, indicate that even moderate earthquakes ( MW < 7.0) can cause significant devastation. On one hand, ongoing urbanization and unprecedented population growth have considerably aggravated the prevailing seismic risk. On the other hand, the available seismic hazard maps covering the entire country are about a decade old. Consequently an updated seismic hazard model for the country is imperative and necessitated by new data, recent findings, and methodological improvements. In the present study, we make a case for new probabilistic seismic hazard analysis (PSHA) of India. The fundamental studies have been carried out to deliver the hazard components, including seismogenic source zonation and seismicity modeling in the Indian subcontinent (Thingbaijam and Nath 2011), assessment of site conditions across the country (Nath, Thingbaijam, Adhikari et al. 2011), and a suitability test for the ground-motion prediction equations in the regional context (Nath and Thingbaijam 2011). These components are integrated to deliver a preliminary model consisting of spatial distributions of peak ground acceleration (PGA) and 5%-damped pseudo spectral acceleration (PSA). Initial attempts at …

Rock fall hazard along the railway corridor to Jerusalem, Israel, in the Soreq and Refaim valleys

We evaluate rock fall hazard along the railway corridor to Jerusalem, Israel, in the Soreq and Refaim valleys. For the purpose, we use a combination of historical information on past rock fall events, field surveys aided by the interpretation of aerial photographs, and numerical rock fall modeling. Historical information indicates that on July 11, 1927 an mL 6.2 Dead-Sea transform earthquake caused rock falls in the studied area. The seismically induced rock falls damaged the railway tracks. Field observations revealed that the source area for the 1927 failures was located in the Aminadav formation, at the contact with the Moza formation. At the stratigraphic contact, rock blocks 100–101 m3 in size are formed as a result of tensile stresses and associated fracturing in the dolomite of the Aminadav formation, combined with continuous creep of the blocks on the marl of the underlying Moza formation. We use topographical, geological, and geomorphological information to calibrate a three-dimensional numerical simulation of rock falls in the studied area. We use the results of the numerical modeling, and additional independent information, to assess rock fall hazard and the associated risk in the Soreq and Refaim valleys. Results indicate that in the studied area, rock fall risk to the railway line to Jerusalem is due primarily to Dead-Sea transform earthquakes, with mL > 6. We identify nine sections of the railway line where rock fall risk exists, for a total length of 2.5 km. We further note that seismically induced rock falls can produce damage to the road network in the studied area, make it difficult or impossible for earthquake casualties to reach hospitals in Jerusalem. We conclude offering recommendations on how to mitigate the risk posed by earthquake-induced rock falls in the studied area.

Estimating the number of casualties in earthquakes from early field reports and improving the estimate with time

We investigate the time dependence of the number of deaths reported through Internet after earthquakes and/or earthquake-generated tsunami. An approximate relation N(t) = N0 [1 − exp(−αt)] is used to describe such temporal variation, in which N(t) is the number of deaths reported at time t, N0 is the final number of deaths, and α is the coefficient reflecting the rescue process. We considered 12 earthquake cases since 2001 using the information from the web, which shows that the N-t relation approximates the data, and the logarithm of α is reversely proportional to the magnitude of earthquake, albeit with significant uncertainties. Quick and rough estimate of the final death toll can be made using this simple and approximate relation, with the empirical α-M relation as a reference. For the 12 cases under consideration, quick and rough estimate of fatalities can be obtained 2 days after the earthquake, fitting the real situation in the order of magnitudes. Although being very rough, this estimate can assist the emergency decision-making and can be revised as time lapses. When more and more data becomes available, curve fitting can provide both N0 and α at the same time. The method is tested against the data of the recent Yushu earthquake on April 14, 2010.

Challenges for rear hospital care of Wenchuan Earthquake casualties: experience from West China Hospital

To review the challenges and counter-measures in the hospital care for Wenchuan earthquake casualties and draw lessons for the protective response in the future. Medical records and laboratory findings of the victims admitted in West China Hospital (WCH) were retrospectively analyzed. Related data were compared between beforemath and aftermath of the earthquake and between WCH and frontier county hospitals. One thousand and thirty-one earthquake survivors were hospitalized, 1358 victims underwent surgery and 142 victims were transferred to intensive care unit. The incidence of infection, crush syndrome and multiple organ dysfunction syndrome (MODS) was 39.6%, 20.7% and 2.3% respectively. Wound classification showed that the incidence of extremity damage was 72%, while the incidence of chest trauma, abdominal trauma and brain trauma was less than 10% respectively. Isolating rates of environmental pathogens were increased in the aftermath of earthquake, and the spectrum of the pathogens and related antibiotic sensitivities were quite different from those in the beforemath of earthquake. The social economic and population conditions in the earthquake-stricken areas affected the composition of the victims and the geographic features restricted the efficiency of rescue. Trauma-induced MODS, crush syndrome and severe infections all constituted the dilemma for the hospital care, to resolve whether the multidiscipline team work was proved to be an optimizing choice. For a more effective disaster protective response in the future, the study on rescue plan and the ladder therapies for massive casualties should be potentiated.

Earthquake Casualties in Italy: The Blame Game

This note focuses on the true and perceived responsibilities for the recent earthquake losses in central Italy and on the status of seismic zoning in our country. The 6 April 2009, Mw 6.3 earthquake near L'Aquila (central Italy) was a standard Apenninic event: its magnitude, depth, and focal mechanism are consistent with the seismotectonic features of the area; historical earthquakes occurred in the same area with comparable characteristics, including a long-lasting sequence of foreshocks and aftershocks; strong ground motions seem to match well with existing predictive relationships; and the seismic hazard reaches the highest levels for Italy both on conventional and on time-dependent probabilistic maps. Despite the fact that a seismic building code was adopted in this area as early as 1927, the unacceptable death toll of the earthquake (around 300 victims) is largely to be blamed on the poor quality of construction. As with past earthquakes, severe damage and collapse mainly affected old buildings (unreinforced masonry or stone buildings); but surprisingly, a number of multistory buildings of relatively new construction (reinforced concrete frame buildings with brick infill) were destroyed too: among these, L'Aquila's main hospital (finished in 2000) and the university's dormitory (built in the late 1970s). As with past earthquakes, severe damage and collapse mainly affected old buildings (unreinforced masonry or stone buildings); but surprisingly, a number of multistory buildings of relatively new construction (reinforced concrete frame …

Blood transfusion therapy for 41 earthquake casualties

Background We aimed to analyze the efficacy of blood transfusions given to Wen Chuan earthquake casualties. Materials and methods Forty-one blood transfusions were administered. Laboratory indexes including routine blood tests, electrolyte tests, and blood coagulation functions were recorded. Results Between 400–6400 mL of whole blood and/or erythrocyte suspensions were given to the casualties. The mean volume was 1233 mL. The plasma volume infused in 22 cases (1550 mL) differed from 200 mL to 9600 mL. There was no occurrence of transfusion reaction. Erythrocyte and Hct levels increased significantly after transfusion, while electrolyte levels remained the same. Conclusion Blood transfusion was an effective therapy for the earthquake casualties.

Global earthquake casualties due to secondary effects: a quantitative analysis for improving rapid loss analyses

This study presents a quantitative and geospatial description of global losses due to earthquake-induced secondary effects, including landslide, liquefaction, tsunami, and fire for events during the past 40 years. These processes are of great importance to the US Geological Survey’s (USGS) Prompt Assessment of Global Earthquakes for Response (PAGER) system, which is currently being developed to deliver rapid earthquake impact and loss assessments following large/significant global earthquakes. An important question is how dominant are losses due to secondary effects (and under what conditions, and in which regions)? Thus, which of these effects should receive higher priority research efforts in order to enhance PAGER’s overall assessment of earthquakes losses and alerting for the likelihood of secondary impacts? We find that while 21.5% of fatal earthquakes have deaths due to secondary (non-shaking) causes, only rarely are secondary effects the main cause of fatalities. The recent 2004 Great Sumatra–Andaman Islands earthquake is a notable exception, with extraordinary losses due to tsunami. The potential for secondary hazards varies greatly, and systematically, due to regional geologic and geomorphic conditions. Based on our findings, we have built country-specific disclaimers for PAGER that address potential for each hazard (Earle et al., Proceedings of the 14th World Conference of the Earthquake Engineering, Beijing, China, 2008). We will now focus on ways to model casualties from secondary effects based on their relative importance as well as their general predictability.