Earthquake loss estimation of residential buildings in Pakistan

Pakistan is an earthquake-prone region due to its tectonic setting resulting in high hazard with moderate-to-strong ground motions and vulnerability of structures and infrastructures, leading to the loss of lives and livelihood, property damage and economic losses. Earthquake-related disaster in Pakistan is a regular and serious threat to the community; however, the country lack tools for earthquake risk reduction through early warning (pre-earthquake planning), rapid response (prompt response at locations of high risk) and pre-financing earthquake risk (property insurance against disaster). This paper presents models for physical damageability assessment and socioeconomic loss estimation of structures in Pakistan for earthquake-induced ground motions, derived using state-of-the-art earthquake loss estimation methodologies. The methodologies are being calibrated with the site-specific materials and structures response, whereas the derived models are tested and validated against recent observed earthquakes in the region. The models can be used to develop damage scenario for earthquakes (assess damaged and collapsed structures, casualties and homeless) and estimate economic losses, i.e., cost of repair and reconstruction (for a single earthquake event as well as all possible earthquakes). The models can provide help on policy- and decision-making toward earthquake risk mitigation and disaster risk reduction in Pakistan.     

Experimental vulnerability curves for the residential buildings of Iran

Iran is one of the most seismically active countries of the world located on the Alpine-Himalayan earthquake belt. More than 180,000 people were killed due to earthquakes in Iran during the last five decades. Considering the fact that most Iranians live in masonry and non-engineered houses, having a comprehensive program for decreasing the vulnerability of society holds considerable importance. For this reason, loss estimation should be done before an earthquake strikes to prepare proper information for designing and selection of emergency plans and the retrofitting strategies prior to occurrence of earthquake. The loss estimation process consists of two principal steps of hazard analysis and vulnerability assessment. After identifying the earthquake hazard, the first step is to evaluate the vulnerability of residential buildings and lifelines and also the social and economic impacts of the earthquake scenarios. Among these, residential buildings have specific importance, because their destruction will disturb the daily life and result in casualties. Consequently, the vulnerability assessment of the buildings in Iran is important to identify the weak points in the built environment structure. The aim of this research is to prepare vulnerability curves for the residential buildings of Iran to provide a proper base for estimating probable damage features by future earthquakes. The estimation may contribute fundamentally for better seismic performance of Iranian societies. After a brief review of the vulnerability assessment methods in Iran and other countries, through the use of the European Macroseismic method, a model for evaluating the vulnerability of the Iranian buildings is proposed. This method allows the vulnerability assessment for numerous sets of buildings by defining the vulnerability curves for each building type based on the damage observations of previous earthquakes. For defining the vulnerability curves, a building typology classification is presented in this article, which is representative of Iranian building characteristics. The hazard is described in terms of the macroseismic intensity and the EMS-98 damage grades have been considered for classifying the physical damage to the buildings. The calculated vulnerability indexes and vulnerability curves show that for engineered houses there is not any notable difference between the vulnerability of Iranian and Risk-UE building types. For the non-engineered houses, the vulnerability index of brick and steel structures is less than the corresponding values of the other unreinforced masonry buildings of Iran. The vulnerability index of unreinforced and masonry buildings of Iran are larger than the values of the similar types in Risk-UE and so the Iranian buildings are more vulnerable in this regard.     

地震灾害经济损失严重性的宏观估算法

对未来发生地震可能造成的经济损失进行预测,是各个地区政府部门进行经济建设规划的一项必不可少的基础性工作。本文着重分析了影响地震灾害损失的因素,提出了定量计算地震灾害经济损失严重性的数学模式。     

模糊神经网络在矿震预测中的应用

矿震同天然地震一样会给矿山生产及人身安全等带来重大灾难。也是目前尚不能准确预测的矿山灾害现象之一。根据现有的研究成果可知，矿震是一个多输入、多干扰、单输出的复杂系统。由于干扰项的存在，使利用建模、神经网络等手段对系统进行预测时会导致很大误差。模糊神经网络系统在建立对象输入、输出关系时与传统数学方法不同。即可以建立在无模型基础上，并利用其较强的学习训练特性，自动获取对象的输入、输出关系表达；可以将专家的评价语言作为系统的干扰项引入。这在一定程度上缓解了人为因素对预测结果的影响，且平滑了观测数据的随机性。文章利用改进的模糊神经网络及抚顺老虎台矿的矿震资料，对矿震最大震级的预测方法进行了探索。‘初步探讨了改进的模糊神经网络在矿震预测中的应用。得出在运用模糊神经网络进行预测时，为减小预测误差，应综合多种因素并提高专家评判语言的精确度的结论。指出在建立矿震系统预测模型时，利用干扰项将人为因素引入系统是必需的。通过实际应用证明其可行性。     

Rapid estimation of ground-shaking maps for seismic emergency management in the Campania Region of southern Italy

Strong ground-shaking mapping soon after a moderate-to-large earthquake is crucial to recognize the areas that have suffered the largest damage and losses. These maps have a fundamental role for emergency services, loss estimation and planning of emergency actions by the Civil Protection Authorities. This is particularly important for areas with high seismic risk levels, such as the Campania-Lucania Region in southern Italy. Taking advantage of the Irpinia Seismic Network (ISNet), a recently installed dense and wide dynamic seismic network, we have developed a procedure for rapid estimation of ground-shaking maps after moderate-to-large earthquakes (GRSmap). This uses an optimal data gridding scheme designed to account for bi-dimensional features of strong ground-motion fields, such as directivity, radiation patterns and focal mechanisms, to which most damage can be correlated. The basis of the mapping technique is a triangulation procedure to locally correct predicted data at the triangle barycentres where their vertices correspond to seismic stations. The method has been tested off-line using a simulated M 6.6 earthquake located at the centre of ISNet and applied to data of the 23 November 1980 Irpina M 6.9 earthquake recorded by a sparse network. This has highlighted its ability to predict peak ground-motion parameters of large magnitude earthquakes with respect to the attenuation relationships.     

Using Bayesian networks in analyzing powerful earthquake disaster chains

Substantial economic losses, building damage, and loss of life have been caused by secondary disasters that result from strong earthquakes. Earthquake disaster chains occur when secondary disasters take place in sequence. In this paper, we summarize 23 common earthquake disaster chains, whose structures include the serial, parallel, and parallel–serial (dendroid disaster chain) types. Evaluating the probability of powerful earthquake disaster chains is urgently needed for effective disaster prediction and emergency management. To this end, we introduce Bayesian networks (BNs) to assess powerful earthquake disaster chains. The structural graph of a powerful earthquake disaster chain is presented, and the proposed BN modeling method is provided and discussed. BN model of the earthquake–landslides–barrier lakes–floods disaster chain is established. The use of BN shows that such a model enables the effective analysis of earthquake disaster chains. Probability inference reveals that population density, loose debris volume, flooded areas, and landslide dam stability are the most critical links that lead to loss of life in earthquake disaster chains.     

Overview of Taiwan Earthquake Loss Estimation System

The National Science Council (NSC) of Taiwan started the HAZ-Taiwan project in 1998 to promote researches on seismic hazard analysis, structural damage assessment, and socio-economic loss estimation. The associated application software, “Taiwan Earthquake Loss Estimation System (TELES)”, integrates various inventory data and analysis modules to fulfill three objectives. First, it helps to obtain reliable estimates of seismic hazards and losses soon after occurrence of large earthquakes. Second, it helps to simulate earthquake scenarios and to provide useful estimates for local governments or public services to propose their seismic disaster mitigation plans. Third, it helps to provide catastrophic risk management tools, such as proposing the seismic insurance policy for residential buildings. This paper focuses on the development and application of analysis modules used in early loss estimation system. These modules include assessments of ground motion intensity, soil liquefaction potential, building damage and casualty.     

Earthquake disaster risk assessment and evaluation for Turkey

Turkey is the one country in which 90% of the buildings are subject to the risk of earthquake disaster. Recent earthquakes revealed that Turkey’s present residential reinforced-concrete constructions are insufficient in earthquake resistance. Many of the buildings which collapsed or were severely damaged have been rehabilitated by applying simple methods, whose adequacy is questionable. As in Japan and the United States, Turkey’s earthquake assessment studies have increased, especially after earthquakes in 1999, In US, several methodologies and standards, such as Hazard-US (HAZUS) and Applied Technology Council (ATC) 13-20-21 and 156, provide comprehensive earthquake loss estimation methodology for post-earthquake assessment. This paper provides post-earthquake assessment and disaster management for Turkey. The main aim of the post-earthquake assessment discussed is to evaluate loss and estimate damage through disaster management approach. Classification criteria for damage are essential to determine the situation after an earthquake in both the short and long terms. The methodology includes probabilistic-based analysis, which considers the magnitude of Ms ≥ 5.0 earthquakes between 1900 and 2005, for determining the probabilistic seismic hazard for Turkey.     

Earthquake losses due to ground failure

Ground shaking is widely considered to be the primary cause of damage to structures, loss of life and injuries due to earthquakes. Nonetheless, there are numerous examples of earthquakes where the losses due to earthquake-induced ground failure have been significant. Whereas ground shaking causes structural and non-structural damage, with associated loss of function and income, ground failure is less likely to cause spectacular structural collapses, but is frequently the cause of major disruptions, particularly to lifelines, which can lead to prolonged loss of function and income, even for undamaged areas.Those involved in earthquake loss modelling are currently presented with three choices with respect to the incorporation of ground failure: they can choose to ignore it, assuming that any estimation of losses caused by shaking would effectively subsume the impact of these secondary hazards; they can include ground failure in a simple manner, using published approaches based upon qualitative data and a large degree of judgement; or, they can opt for a detailed site- or region-specific assessment of damage due to ground failure, with the associated time and expense.This paper presents a summary of the principal features of earthquake losses incurred in damaging earthquakes over the last 15 years. Survey data are impartially analysed, considering both ground failure and ground shaking as sources of damage, and their relative contribution to overall damage in each section of the regional infrastructure is presented. There are many other variables influencing these contributions, including the size of the earthquake, the economic status of the affected region, local geology and terrain and the building stock, which have been considered.The findings of the study are discussed from the point of view of loss modelling and which components of a model should merit the most time and resource allocation. The general assumption that ground shaking is the principal cause of damage and loss is strongly supported by the study. However, there are a number of scenarios identified where the failure to appropriately include the effects of ground failure would lead to unrealistic loss projections. Such scenarios include the assessment of building losses in small zones rather than on a regional basis, and the incorporation of lifeline damage or disruption and indirect losses into a model.     

1996～2005年中国大陆震害情况与减灾建议

地震是典型的突发性地质灾害,破坏性极大.本文首先对1996～2005年这10年间的大陆地震发生情况以及地震灾害情况进行了统计分析,列举了直接经济损失超过1亿元的重大地震灾害,指出大陆防震减灾要有地域特点;然后提出了一些防震减灾建议,如注意防范地震引发的次生灾害,加强建筑抗震设计和加固,推广使用现代信息技术,积极开展防震减灾能力评价,通过合理的城市规划和土地利用规划来减轻地震灾害.     

Integrating the geographic information system and predictive data mining techniques to model effects of compound disasters in Taipei

Located in the circum-Pacific seismic zone, Taiwan is continually threatened by such natural disasters as typhoons, floods, landslides, and earthquakes, which increase risk of property loss and severely endanger public safety. Taipei City, the political and economic capital of Taiwan, must address disaster prevention and relief operations for compound disasters and extreme climatic events in addition to existing metropolitan disaster prevention operations. This study formulates 48 compound-disaster scenarios based on threats to Taipei City due to heavy rainfall and surrounding faults. Hydrology and flood analysis results and the Taiwan earthquake loss estimation system are utilized to assess the potential for compound disasters and the number of people they would displace in Taipei’s administrative districts. Analytical results can be used to create a pre-disaster static potential diagram and a refuge or shelter capacity assessment table. The disaster potential diagram is adopted to conduct geographic information system spatial and data analysis, and temporary refuges or shelters planned by the city government are integrated for shelter capacity comparison. Furthermore, a dynamic assessment curve for the number of displaced people during a disaster is plotted using data mining and attribute filtering. Subsequently, a cross table is obtained and employed to predict the number of refugees in the various administrative districts. Finally, conclusions and recommendations are provided for making disaster prevention and relief decisions simultaneously concerning earthquakes and flooding.     

青藏高原东南缘活动断裂地质灾害效应研究现状

青藏高原东南缘不同性质、不同类型、不同特点活动断裂发育且较为活跃,自2008年汶川地震发生以来,相继发生了玉树地震、庐山地震、鲁甸地震等。地震引发、触发、诱发产生了大量地质灾害,造成了惨重的生命财产损失。通过收集与分析相关资料,对青藏高原东南缘活动断裂地质灾害效应研究进展与取得成果进行了归纳总结,从活动断裂地质灾害主要控制因素,地质灾害发育特征、空间分布规律、演化模式、形成机制,不同性质断裂控制效应、断裂两盘差异效应、地震动参数效应、地形地貌效应等地质环境效应和地质灾害力学效应等方面进行了综述。在此基础上,对活动断裂地质灾害效应研究中存在的如不同类型活动断裂和不同震级地震与地震地质灾害相关性、以及地震地质灾害监测与风险评估等问题或重点研究方向进行了探讨,其研究结果为地震地质灾害致灾机理、风险评估、防灾减灾等研究提供参考。      

The 27 August 2010 Mw 5.7 Kuh-Zar earthquake (Iran): field investigation and strong-motion evidence

In this study, seismological aspects and field observation of the 2010 Kuh-Zar earthquake has been investigated. The Kuh-Zar earthquake, of magnitude 5.7 (Mw), occurred in northeastern Iran on August 27, 2010. The area is surrounded by branches of the active faults which are coated by the quaternary alluvium. During the past several decades, this area has been struck by a number of earthquakes. This earthquake with a moderate magnitude caused a higher rate of damage contrasted with previous earthquakes of the same magnitude range in Iran. Fortunately, the source of the Kuh-Zar earthquake was in a sparsely populated area, and therefore, it caused a few loss of life with the highest observed intensity of shaking VII (modified Mercalli intensity) in the Kuh-Zar village. The shock killed 4 people, injured 40, and destroyed more than 12 villages. According to the field observation, the mechanism of this shock is defined as a left-lateral strike slip. We also checked out the properties of strong ground motions in this earthquake using the records availed by Iranian strong motion network. At KUZ station, about 7 km east of the epicenter, the recorded PGA and PGV in both horizontal and vertical components were remarkably large for an event of this size, and visual inspection of the velocity time history reveals a pulse-like shape. Unfortunately no other recording stations were located close enough to the fault to capture a directivity pulse. Finally, according to the strong-motion properties and observed information, ShakeMaps of the earthquake have been generated by the native intensity observations and the recorded strong motions.     

Constructing a social vulnerability index to earthquake hazards using a hybrid factor analysis and analytic network process (F’ANP) model

Iran is a seismic prone country and has been host to a long series of devastating earthquakes which have resulted in heavy casualties and damages. In order to assess social vulnerability (SV) to earthquake hazards, this paper presents the development of a hybrid factor analysis and analytic network process model for aggregating vulnerability indicators into a composite index of SV to earthquake hazards. The proposed model is then applied in Iran as a case study. The proposed model uses factor analysis (FA) to extract the underlying dimensions of SV. The identified dimensions of SV and their primary variables are then entered into a network model in Analytic Network Process (ANP). The ANP is used to calculate the relative importance of different SV variables, taking into consideration the results obtained from FA and the possible interdependence between variables of the individual dimensions of SV. These weights are then used to compute the factor scores for the individual dimensions of SV and also the composite social vulnerability index (SOVI). The application of the proposed model to a real world case study and its validation show that it is a robust approach for constructing a composite SOVI. Its application to counties in Iran indicates that there exist severe regional differences in terms of SV to earthquake hazards. The pronounced regional variations in SV warrant special attention by both local authorities and the national government to reconsider current natural disaster management strategies.     

Regional economic impact analysis of earthquakes in northern Taiwan and its implications for disaster reduction policies

The direct damage caused by earthquakes, such as impaired buildings, may interfere with normal business operations and disrupt the function of the industrial chain. Such economic impacts can be evaluated using the input–output analysis developed by Leontief. In this paper, two scenario earthquakes in northern Taiwan both with a return period of 475 years—the Hsinchu Hsincheng and the Yilan Nan-ao earthquakes—are simulated. The results show that the economic impact caused by the Hsincheng earthquake is greater than that resulting from the Nan-ao earthquake, which should be the major scenario considered for the disaster reduction plan. The industries affected the most are the manufacturing, food services and entertainment, storage and retail trade, and public and construction industries. The Nan-ao earthquake causes relatively more losses in the food services and entertainment industries. Most of the repercussion effects of these industries are in the central and southern parts of Taiwan. The loss to the manufacturing sector and its repercussion effects are enormous. Therefore, the government should make it a first priority to encourage the manufacturing sector to implement earthquake mitigations, such as a seismic retrofit, or to provide a seismic evaluation, which can enable firms to engage in mitigation voluntarily. The measure needed to reduce the loss in agriculture is that the government can purchase agricultural products in central and southern Taiwan following the disaster and offer them to survivors in northern Taiwan.     

Earthquake prediction activities and Damavand earthquake precursor test site in Iran

Iran has long been known as one of the most seismically active areas of the world, and it frequently suffers destructive and catastrophic earthquakes that cause heavy loss of human life and widespread damage. The Alborz region in the northern part of Iran is an active EW trending mountain belt of 100 km wide and 600 km long. The Alborz range is bounded by the Talesh Mountains to the west and the Kopet Dagh Mountains to the east and consists of several sedimentary and volcanic layers of Cambrian to Eocene ages that were deformed during the late Cenozoic collision. Several active faults affect the central Alborz. The main active faults are the North Tehran and Mosha faults. The Mosha fault is one of the major active faults in the central Alborz as shown by its strong historical seismicity and its clear morphological signature. Situated in the vicinity of Tehran city, this 150-km-long N100° E trending fault represents an important potential seismic source. For earthquake monitoring and possible future prediction/precursory purposes, a test site has been established in the Alborz mountain region. The proximity to the capital of Iran with its high population density, low frequency but high magnitude earthquake occurrence, and active faults with their historical earthquake events have been considered as the main criteria for this selection. In addition, within the test site, there are hot springs and deep water wells that can be used for physico-chemical and radon gas analysis for earthquake precursory studies. The present activities include magnetic measurements; application of methodology for identification of seismogenic nodes for earthquakes of M ≥ 6.0 in the Alborz region developed by International Institute of Earthquake Prediction Theory and Mathematical Geophysics, IIEPT RAS, Russian Academy of Science, Moscow (IIEPT&MG RAS); a feasibility study using a dense seismic network for identification of future locations of seismic monitoring stations and application of short-term prediction of medium- and large-size earthquakes is based on Markov and extended self-similarity analysis of seismic data. The establishment of the test site is ongoing, and the methodology has been selected based on the IASPEI evaluation report on the most important precursors with installation of (i) a local dense seismic network consisting of 25 short-period seismometers, (ii) a GPS network consisting of eight instruments with 70 stations, (iii) magnetic network with four instruments, and (iv) radon gas and a physico-chemical study on the springs and deep water wells.     

Natural hazards and disasters in Latin America

Natural hazards and disasters occur widely throughout the world. Disasters can be costly both in terms of human lives and property and ecosystem disruption. Higher death tolls in developing nations may be the result of poverty, rapid population growth, urbanization, and inadequate communication facilities. The purpose of this study is to show patterns of major catastrophic events in Latin America so that their impacts can be evaluated and compared.Latin America was selected because of the variety of recent events commanding wide attention: earthquakes in Mexico, volcanic eruptions in Colombia, hurricanes and floods in Haiti, and drought and mudflows in Brazil. Spatial and temporal aspects of natural disasters are presented in nine tables and 21 maps. The tables give selected disaster data by country for volcanic eruptions, earthquakes, landslides, and atmospheric disturbances from the 16th century to 1989. Most data is derived from disasters occurring during the 20th century and include number of events, people killed, people affected, and U.S.$ damage. Maps show environmental settings for disasters and allow detailed comparison among countries. Floods account for the greatest number of major events in the most countries, earthquakes cause the most deaths and damage, while droughts affect the most people. Peru surpasses all others in susceptibility to major disasters. Assessment of vulnerability to hazards, improved economic opportunities, and an increased social and political concern for poor people should help reduce future losses from natural disasters in Latin America.     

Verification of a new method for evaluation of liquefaction potential analysis

The seismic response of existing earth dams in Iran is important after an earthquake both to provide emergency supplies and to society as well as to ensure structural safety in engineering terms. Better seismic capacity of earth dam results in less structural damage and reduced impacts following an earthquake disaster. Indirect as well as direct costs following earthquakes have gained much attention from both the engineering and socioec onomic research communities in the last few decades. This study is a valuable tool used to study the response of geotechnical structures to infrequent or extreme events such as earthquakes. The Avaj earthquake (2002, Iran) was applied to a series of model tests which was conducted to study the response of soil profiles under seismic loading. The acceleration records at different locations within the soil bed and at its surface along with the settlement records at the surface were used to analyze the soil seismic response. A combination of several software packages with a generated visual user interface computer code by authors named as “Abbas Converter” were employed to evaluate the variation of shear modulus and damping ratio with shear strain amplitude to assess their effects on site response. The proposed method was applied to the Korzan earth dam of Hamedan province in Iran. Site response analysis using the measured shear wave velocity, estimated modulus reduction, and damping ratio as input parameters produced good agreement with the computed site response in this study.     

Earthquake preparedness: the case of Eastern UAE

During the last 30 years, UAE witnessed earthquakes that ranged from minor to moderate, with maximum magnitude of 5.1 that occurred in the Masafi area (eastern UAE, on March 11, 2002). Recent earthquakes that hit Iran such as on May 11, 2013, caused tremors and mild shaking of buildings in some UAE cities. Although the tremors are small in magnitude, their sequences apparently become an important research topic and deserve more assessment from different perspectives such as geographical, geological, engineering, and social. This is because low risk does not equal no risk. This study is concerned with public perceptions of earthquake preparedness (reduction of disaster impact) that can be measured by various variables such as developing an emergency plan, preparation of disaster supply kits, and training. The methodology consists of a survey of 470 people who live around the Masafi area, near Fujairah city, UAE. GIS and GPS were used for site selection in conducting the survey, and remote sensing was used as an aid in identification of buildings’ ages. Results show that around 90% of the people surveyed have water tanks that can support them up to 3 days, and 60% of them normally buy food that can support them up to 2 days. Thirty percent of the respondents were familiar with storing first-aid kits and tools such as flashlights. The findings point to a need for more research regarding public awareness about earthquakes. The findings of this study may be useful for people who are involved in the four cornerstones of disaster risk reduction: community participation, public policy actions, safer construction and urban development, and development of a culture of prevention.