Earthquake Vulnerability Research Articles

Assessing the Cascading Post-Earthquake Fire-Risk Scenario in Urban Centres

The frequency of urban fires has grown in recent years everywhere, especially in historic districts, including in Portugal, due to the existence of sensitive igniting materials, the proximity of buildings, the complex urban layout, and the presence of many people. The current study proposes a technique, applied in the Baixa Pombalina (downtown) area in Lisbon, to undertake an appropriate evaluation of the post-earthquake fire cascading effect, which may cause major damage. The earthquake vulnerability and damage scenario were carried out using the Risk-UE method. An empirical fire ignition model was then applied to determine the quantity and location of fire ignitions for different return periods. Furthermore, the simple fire spread Hamada’s model was applied to both the equally spaced grid buildings, as in the original Hamada procedure, and the current study area layout for different time thresholds. Finally, the risk assessment for both models was carried out, allowing for the estimation of earthquake and fire losses, respectively. The results demonstrated that the models are comparable, showing that the Hamada model might be a useful tool for large-scale evaluations aimed at disaster-risk reduction and management since it gives useful information for managing and reducing natural and anthropogenic hazards.

Edy App: Earthquake Mitigation Innovation Using GIS for Disaster Response in Pariaman, Indonesia

Pariaman City, located along the Semangko fault line and the subduction zone of the Indo-Australian and Eurasian plates, is highly vulnerable to earthquakes and tsunamis. The region's susceptibility to large earthquakes, followed by vertical deformations, highlights the need for effective disaster mitigation. In response, this study proposes the development of the Earthquake Buddy Application (EDY App), designed to assist with earthquake mitigation efforts. The EDY App leverages Geographic Information System (GIS) technology to map earthquake-prone areas, provide early warnings, suggest evacuation routes and Temporary Evacuation Sites (TES), and facilitate aid distribution. This Android-based mobile application focuses on four key aspects: education, mitigation, evacuation, and donation. Key features include an Earthquake Vulnerability Map, real-time early warnings, mitigation instructions, TES recommendations with distance and time estimations, emergency contact options, and donation channels. Built with React Native, PHP, and MySQL, and integrated with Google Maps API, the app is designed to be user-friendly and accessible to the public. The EDY App’s contribution to earthquake mitigation lies in its ability to create a disaster-aware community. By offering comprehensive information and support during critical moments, the app can potentially reduce casualties and enhance community preparedness in earthquake-prone regions like Pariaman. Through this innovation, it is expected that residents will be better equipped to respond to natural disasters, promoting a culture of safety and resilience.

Smart Green Concrete: Innovation of Concrete Materials from Fly ash Waste and Lapindo Mud Integrated Smart E. crassipes Coir Geotextile to Realize Indonesia's Sustainable Infrastructure

Pariaman City, situated near the Semangko fault and the Indo-Australian plate subduction zone, is highly prone to earthquakes and tsunamis. To address this, the Earthquake Buddy Application (EDY App) was developed as an innovative solution for disaster mitigation. EDY App utilizes Geographic Information Systems (GIS) to provide real-time earthquake vulnerability maps, early warnings, and evacuation route suggestions to Temporary Evacuation Sites (TES). It also offers education on earthquake preparedness and facilitates donations for relief efforts. The application’s main contribution lies in its integration of comprehensive disaster management tools into one platform. By providing critical information during emergencies, the app empowers users to make informed decisions, which can reduce casualties in high-risk areas. The app also encourages community preparedness by offering accessible education on earthquake mitigation. EDY App is designed to create a disaster-resilient society in Pariaman, ensuring that residents are better equipped to respond to natural disasters through real-time alerts and evacuation support, ultimately enhancing local preparedness and reducing the potential impact of future earthquakes.

Seismic vulnerability analysis of hospitals and school buildings considering the Gaussian regression algorithm

This study combines the Gaussian regression algorithm to propose a nonlinear regression model that can be used to evaluate the seismic vulnerability of regional hospitals and school buildings. The failure features and disaster mechanisms of hospital and school buildings affected by the Jishishan (JSS) earthquake on December 18, 2023, and the Wenchuan (WC) earthquake on May 12, 2008, were reported. The samples of 252 damaged buildings (37 hospitals and 215 schools) in Dujiangyan city affected by the Wenchuan earthquake for which the author participated in the survey were collected and counted. Hospitals and school buildings were classified according to the types of reinforced concrete (RC) and masonry structures, and earthquake vulnerability probability matrices for hospital and school building clusters were established considering the actual failure probabilities. A total of 2103,213 acceleration records (from the Wenchuan earthquake) monitored by 12 real stations were selected. Using dynamic time history and response spectrum analysis methods, time history and spectrum curves were generated, considering the influence of different seismic directions. Using the developed Gaussian regression model, vulnerability comparison curves and parameter matrices considering multiple regression algorithms were generated. This paper considers the effects of the construction year and number of floors on the seismic vulnerability of hospital and school buildings. Seismic vulnerability curves and failure probability matrices were generated and established on the basis of actual structural failure probabilities. According to regression and vulnerability surface analysis, the evaluation results of the proposed model are highly consistent with actual field observations.

Micro Zonation to Earthquake Vulnerability in West Semarang Coastal Indonesia Area Based on HVSR (Horizontal to Vertical Spectral Ratio) Microtremor Method

Micro Zonation to Earthquake Vulnerability in West Semarang Coastal Indonesia Area Based on HVSR (Horizontal to Vertical Spectral Ratio) Microtremor Method

Integration of Microtremor and PS-INSAR Analysis to Investigate the Susceptible Area in the Pronojiwo District (Indonesia) Following the 2021 East Java M6.1 Earthquake

The East Java M = 6.1 Earthquake struck on April 10, 2021, at the bottom of the Indian Ocean, about 96 km south of Kepanjen District, Malang Regency, Indonesia. The neighbouring Pronojiwo District in Lumajang Regency suffered significant damages and loss of lives. The earthquake aftermath underscored the necessity of examining susceptibility factors in the Pronojiwo area for future mitigation efforts. This research focuses on assessing earthquake vulnerability in Pronojiwo District using two methodologies: microtremor analysis and PS-InSAR. Microtremor data were directly collected, while PS-InSAR data were acquired from the Sentinel-1 satellite and processed using the ranging from 0.579 × 10 to 24.840 × 10 s /cm, in Pronojiwo District, with notably higher values found in areas with Semeru deposits, characterized by soft sediments. PS-InSAR analysis indicates concentrated negative shifts in residential zones, signaling structural damage. Regions with elevated vulnerability index values and negative PS points are considered more prone to earthquakes and subsequent building damages.

Eigenvector spatial filtering enhancing natural hazards vulnerability assessment in a susceptible urban environment: A case study of Izmir earthquake in Turkey

The increasing risk of earthquakes in urban areas has made it crucial to develop accurate vulnerability models for city infrastructure and systems. We aimed to assess and compare the effectiveness of different models and vulnerability analysis techniques in predicting earthquake vulnerability in the specific context of Izmir, Turkey. One central hypothesis in this research aimed to determine whether integrating Eigenvector Spatial Filtering (ESF) into both regression models and machine learning algorithms would yield a comparable enhancement in model performance. We performed earthquake vulnerability modeling (EVM) by considering (ⅰ) only seismic-related variables (SRV) and (ⅱ) integrating ESF by using Moran's eigenvector maps (MEMs). For each approach, we evaluated the predictive performance of two simple regression-based models; generalized linear model (GLM) and generalized additive model (GAM), and two complex machine learning ones; generalized boosting model (GBM), and random forest (RF). The study utilized five primary indicators encompassing geotechnical, physical, structural, social, and facilities data. The predictive performance of the models was assessed using evaluation metrics including Root Mean Square Error (RMSE), Mean Absolute Error (MAE), and adjusted R2. The results indicated that the optimal candidate model consisted of five key variables: altitude, building height, distance to safety gathering places, Peak Ground Acceleration (PGA), and population density. We found that decision-tree-based methods performed better than regression-based methods for both modeling schemes. RF exhibited the highest predictive performance for the training data (RMSE = 0.59, adjusted R2 = 0.71), while GBM outperformed other models for the test data (RMSE = 0.79, adjusted R2 = 0.78). However, incorporating ESF to the EVM analysis revealed that regression-based methods, particularly the GLM, obtained highest improvement in accuracy (RMSE 0.94 vs 0.76 and adjusted R2 0.56 vs 0.71 for the SRV and SRV + MEMs modeling approach). Significant differences were observed between GLM-GBM and GLM-RF comparisons, as well as GAM-GBM and GAM-RF comparisons. The findings of this research are expected to be helpful for informed decision-making, targeted risk reduction, and the development of effective policies and strategies to enhance preparedness and resilience in the face of seismic events in highly susceptible urban systems.

Field Reconnaissance and Earthquake Vulnerability of the RC Buildings in Adıyaman during 2023 Türkiye Earthquakes

The 6th February 2023 Pazarcık and Elbistan earthquakes (Mw = 7.7 and Mw = 7.6) caused great destruction in many cities and were the disaster of the century for Türkiye. The greatest destruction was caused in the provinces of Hatay, Kahramanmaraş, and Adıyaman during these earthquakes, which were independent of each other and occurred on the same day. Information about earthquakes and strong ground motion records is given within the scope of this study. Reinforced concrete (RC) structures which constitute a large part of the urban building stock in the earthquake region were exposed to structural damage at different levels. The structural damage in the RC structures in the city center, Gölbaşı, and Kahta districts of the province of Adıyaman was evaluated within the scope of earthquake and civil engineering after field investigations. Insufficient RC, low-strength concrete reinforcement problems, RC frame failure, heavy overhang, short columns, soft story, and pounding effect are the main causes of the earthquake damage. The presence of these factors that reduce the earthquake resistance of RC structures increased the damage level. In addition, the fact that the earthquakes occurred nine hours apart and the continuation of aftershocks during that period negatively affected the damage levels. It has been observed that structures that receive the necessary engineering services during the construction and project phases ensure the safety of life and property, even if the structure is slightly damaged. In this study, we also tried to reveal whether the target displacements were satisfactorily represented by numerical analysis for a sample RC structure.

MICROZONATION ANALYSIS IN MANNA CITY & PASAR MANNA SUBDISTRICTS UTILIZING MICROTREMOR DATA, SOUTH BENGKULU REGENCY

South Bengkulu is prone to earthquakes because it is located on the Great Sumatran Fault. Apart from that, it is also influenced by the activity of the Musi and Manna segments, so that besides being influenced by the two active tectonic plates it is also influenced by the local segment. This research is located in Manna City and Manna Market, which is mostly inhabited by people and is the capital of South Bengkulu. In connection with infrastructure development, it is necessary to know the condition of the soil layers to minimize the risk of building damage due to earthquakes. This research aims to analyze earthquake-prone areas based on dominant frequency parameters, soil amplification, seismic vulnerability index and sediment layer thickness (h). Research data comes from microtremor measurements at 60 measuring station points in Manna City and Manna Market. The tool used is a Short Period Portable Seismometer Model Gemini 2 SN-1405. This microtremor data is processed using the Horizontal to Vertical Spectral Ratio (HVSR) method. The results of data processing show that the research area has the lowest dominant frequency of 3.95 Hz and the highest of 49.71 Hz. The ground vibration amplification value is classified as small to medium, the lowest is 1.3 and the highest is 5.19. The lowest earthquake vulnerability index was 0.18 cm2/s and the highest was 2.24 cm2/s. The smallest sediment thickness was 3.77 meters and the thickest was 47.48 meters. From the results of the calculation of the seismic vulnerability index in Kota Manna and Pasar Manna Districts, the seismic vulnerability index value is relatively small, in accordance with the amplification factor and the thickness of the sediment layer. Based on this research, although Manna City and Manna Market are often shaken by earthquakes, the earthquake vibrations experience small amplification.

The Uncertain Certainty of a Nightmare: What If Another Destructive Earthquake Strikes Izmir (Türkiye)?

On 6 February 2023, near Kahramanmaraş in south-central Türkiye, an event underscored the vulnerability of cities to seismic activity, revealing a lack of preparedness for substantial shocks. The contributing factors are manifold, yet fundamentally, the collapse of buildings and infrastructure can be attributed to an underestimated capacity for meticulous settlement planning (location) and the adoption of advanced techniques for resilient construction (structure). Regrettably, as has been investigated by many research works, ordinary urban planning in Türkiye hardly finds ways to integrate the vulnerability analysis for settlement expansion, which includes the full integration of geological characteristics with the analysis of building sensitivity. With this work, we wanted to build a composite risk index based on earthquake vulnerability, hazard amplification map, and exposure. We designed the composite index in Izmir’s basin, Türkiye’s third most populated city, to answer the question: What if a destructive earthquake strikes this densely settled area? The results illustrates how the coupled integration of digital data on geology with settlements and infrastructure in a Geographic Information System environment can be used to produce risk maps and plan the anthropic system’s adaptation carefully. Findings demonstrate the city is highly vulnerable to earthquakes and identify priority areas for planning intervention, relocation, and renovation of buildings.

DBDM: Dominance Based Decision Making and GIS Integrated Earthquake Vulnerability Assessment of Elaziğ/Türkiye

DBDM: Dominance Based Decision Making and GIS Integrated Earthquake Vulnerability Assessment of Elaziğ/Türkiye

Assessing Earthquake-Induced Housing Damage: A Fuzzy Ahp Approach Incorporating Local Parameters and Pga Zoning in the Bantul District, Indonesia

Earthquakes used to cause significant harm, including loss of life and damage to buildings and infrastructure. For example, the 2006 Yogyakarta earthquake in Indonesia resulted in widespread devastation, injuries, and extensive damage. In the past, people relied on Seismic Risk Assessment (SRA) to estimate the chances of earthquake-related damage to buildings and infrastructure and the economic losses involved. SRA used vulnerability functions to understand how susceptible buildings were to earthquake damage. Many places and situations used the Hazard United States (HAZUS) system, which had categories like slight, moderate, extensive, and complete damage, to classify building damage. However, there used to be differences in expert opinions about earthquake vulnerability due to variations in their knowledge and experience. Experts often used words like “very high” or “low irregularity” to express their understanding, and they evaluated these factors using qualitative logic. Different approaches were explored in the past to tackle the complexity and uncertainty in the assessment process, including fuzzy logic. The methodology presented in this paper introduced a framework called Fuzzy Analytic Hierarchy Process (FAHP). This framework aimed to assist decision-makers, engineers, and policymakers in choosing the most appropriate category for assessing earthquake-induced housing damage. Four experts with over twenty years of experience in disaster management, earthquake-affected residential housing, and related fields were involved in the research. The goal was to present a method for estimating the Best Nonfuzzy Performance value (BNP) weight based on differences in Peak Ground Acceleration (PGA) zoning (green, yellow, and red zones) in the Bantul district. The results showed that slight damage had the highest score in the green zone, while complete damage had the lowest score. Similarly, in the yellow zone, slight damage maintained the highest score, while complete damage received the lowest score. Lastly, moderate damage was identified as the most critical in the red zone, and complete damage had the lowest score. These findings had implications for decision-makers, engineers, and policymakers: 1). Decision-makers could use this information to allocate budgets efficiently for safety measures. 2). Engineers were able to focus on strengthening structures in the green zone for slight damage and allocate more resources to address moderate damage in the red zone. 3). Policymakers had the opportunity to tailor disaster response plans based on the predominant damage state in each zone, allowing them to prioritize evacuations and resource deployment accordingly. This paper provides an overview that needs to be developed by researchers in order to improve the results and offer more effective education.

Seismic Hazard Assessment in Maluku Province Using PSHA

On 10 January 2023, a strong earthquake with a moment magnitude (Mw) of 7.5 occurred in Banda Sea, Maluku Province. This earthquake caused casualties around the epicentre due to the building collapse which was not an earthquake-resistant structure. A high level of seismic vulnerability and non-standard infrastructure often result in large losses when earthquakes occur. Therefore, mapping of earthquake-prone areas needs to be carried out to optimize the mitigation efforts based on Peak Ground Acceleration (PGA) and Spectrum Acceleration (SA) values. In this paper, mitigation efforts are carried out by mapping earthquake-prone areas using Probabilistic Seismic Hazard Analysis (PSHA) which considers the potential of each complex earthquake source in Maluku Province. Input data was obtained from several earthquake catalogues such as Advanced National Seismic System (ANSS), International Seismological Center (ISC), and United States Geological Survey (USGS) which were processed and analyzed using the Matlab, ZMap, and R-CRISIS programs and mapped using the ArcMap program. The results of PSHA show that Maluku Province is a region with varying levels of earthquake vulnerability. The research results show that the distribution hazard value on PGA in Maluku Province reaches 0.02g to 0.48g for a return period of 500 years and 0.04g to 0.79g for a return period of 2,500 years and on SA for periods of 0.20 seconds and 1.00 second reaches 0.04g to 0.89g and 0.01g to 0.22g for a return period of 500 years and 0.07g to 1.48g and 0.02g to 0.35g for a return period of 2,500 years, respectively. The highest level of vulnerability is in the northern region including Seram Island, Way Apu Island and Ambon Island and the lowest level of vulnerability is in the eastern region including Aru Island.

Comparison of earthquake risk for masonry and RC buildings in Barcelona using existing sets of vulnerability functions

Barcelona is in an area of low- to medium-seismicity and its earthquake vulnerability and risk has been assessed in different studies over the last 20 years. Most of these works have developed vulnerability models for the representative building classes of the city, trying to capture their main characteristics, and have been mostly represented through fragility curves. However, due to the lack of data for historical earthquake losses in the city, it has not been possible to validate, nor calibrate, any of these vulnerability models. In the absence of earthquake loss data, the objective of this paper is to compare the earthquake risk results of Barcelona, using common hazard and exposure datasets and different sets of vulnerability functions from previous studies to see how they rank compared with other locations with similar studies but more complete historical loss data. The results show large differences between the analysed vulnerability datasets, with some results that in our view tend to overestimate earthquake risk in Barcelona, and also allow identifying critical aspects that require future research.

Determination of the seismic vulnerability of infilled RC buildings according to the Quadrants assessment method

The earthquake vulnerability of the buildings has become more important after significant structural damages due to seismic events. The Quadrants assessment method is one of the effective procedures for the determination of the earthquake performance of the buildings. In this study, the impact of the infill walls on the structural vulnerability of reinforced concrete (RC) buildings was investigated using this method. Five different building models are designed such as bare RC frame, RC frame with strut infill as per field test (open ground story), RC frame with strut infill as per ASCE-41-06 (open ground story), full RC frame with strut infill as per field test (fully infilled), and full RC frame with strut infill as per ASCE-41-06 (fully infilled). All structural analyses were performed using an adaptive pushover analysis in the SeismoStruct software. The infills in the studied RC buildings were modeled as an equivalent strut as per field test or ASCE-41-06 code. The influence of different building models on the performance point, overstrength factor, response reduction factor, and ductility reduction factor was evaluated. The performance point is calculated as per the ASCE-41-06 code which is based on the “displacement coefficient method” and the application of the performance point is used to decide on the intervention/retrofit of RC structures through the “Quadrants assessment method”. In this study, the results depict that the strut width of the infill as per ASCE-41-06 is underestimated as compared to field test. Thus, the impact of the strut width is quantified on the seismic design parameters. It is concluded that there is a need for intervention/retrofit of the bare frame and open ground story RC infilled frame based on the “Quadrants assessment method” due to the absence of infills and the calculated values of the response reduction factor (R) obtained for the infilled RC building models are higher than the bare frame structure due to presence of infills.

Seismic vulnerability and inventory of at-risk elements in the wine industry: Auckland region case study

Seismic vulnerability is a major threat to New Zealand's winery industry. Many studies have assessed the vulnerability of New Zealand wineries, especially in high seismic regions. However, few studies have been conducted to assess the earthquake susceptibility of wineries in low seismic regions, such as Auckland. This study investigated the earthquake vulnerability of wineries in the Auckland region by (i) creating an inventory of the elements at risk in the wineries and (ii) assessing the level of vulnerability of these elements. As case studies, twenty-one wineries from various parts of the Auckland region were chosen. The research findings identified key elements at risk of seismic hazard in Auckland wineries using a field survey, including buildings, storage tanks, catwalks, and barrel racks. Furthermore, the findings revealed that at-risk elements are vulnerable to moderate to high levels, emphasising the need for resilience strategies to reduce potential earthquake losses. This study concluded that low seismic risk does not imply low vulnerability, and that Auckland winery owners should reconsider their views on seismic risk mitigation. The study's findings benefit both winery owners and industry professionals by providing insights into the Auckland winery's vulnerability level and recommending approaches to improving the winery's organisational resilience.

Predictive modeling of earthquake vulnerability using geospatial data: a focus on Pakistan

Predictive modeling of earthquake vulnerability using geospatial data: a focus on Pakistan

Urban Earthquake Vulnerability Assessment and Mapping at the Microscale Based on the Catastrophe Progression Method

Vulnerability assessment and mapping play a crucial role in disaster risk reduction and planning for adaptation to a future earthquake. Turkey is one of the most at-risk countries for earthquake disasters worldwide. Therefore, it is imperative to develop effective earthquake vulnerability assessment and mapping at practically relevant scales. In this study, a holistic earthquake vulnerability index that addresses the multidimensional nature of earthquake vulnerability was constructed. With the aim of representing the vulnerability as a continuum across space, buildings were set as the smallest unit of analysis. The study area is in İzmit City of Turkey, with the exposed human and structural elements falling inside the most hazardous zone of seismicity. The index was represented by the building vulnerability, socioeconomic vulnerability, and vulnerability of the built environment. To minimize the subjectivity and uncertainty that the vulnerability indices based on expert knowledge are suffering from, an extension of the catastrophe progression method for the objective weighing of indicators was proposed. Earthquake vulnerability index and components were mapped, a local spatial autocorrelation metric was employed where the hotspot maps demarcated the earthquake vulnerability, and the study quantitatively revealed an estimate of people at risk. With its objectivity and straightforward implementation, the method can aid decision support for disaster risk reduction and emergency management.

Post-2015 earthquake vulnerability of typical RC buildings in Kathmandu Valley

Continuous assessment of the existing conditions of the buildings and performance expectations for future earthquakes is quite crucial for a high-seismic-risk city like Kathmandu. This study aimed to understand the impact of the 2015 Gorkha earthquake on the reinforced concrete (RC) buildings in Kathmandu Valley. The primary objective of this research is to compare the performance of RC buildings in pre-2015 and post-2015 mainshock-aftershocks-damaged conditions. In a nonlinear model of typical RC representative buildings in Kathmandu, incremental dynamic analysis (IDA) was carried out using a real suite of ground motion records, and the Park-Ang damage index was used to classify the damage. Fragility curves were constructed using the probabilistic seismic demand model (PSDM) from the IDA analysis, and comparisons were made between pre-2015 conditions and post-2015 conditions. The findings indicate that the most recent buildings were not significantly harmed by the Gorkha earthquake, and the performance anticipated for future earthquakes reveals that the code principles for design-level earthquakes do not adequately concur with the performance expected. Additionally, the expected seismic performance of the buildings is shown for several future earthquake scenarios.

Evaluating earthquake vulnerability of 2023 Kayseri, Türkiye via BWM-ABAC method

Evaluating earthquake vulnerability of 2023 Kayseri, Türkiye via BWM-ABAC method