Search Results (461)

Natural hazards and their negative impacts on assets are increasing because of a variety of causes, including climate change, population expansion, and urbanization. Moreover, several areas are susceptible to multiple hazards that interact spatially and/or temporally, necessitating a multi-hazard assessment to adequately mitigate their effects. The goal of this study is to investigate the direct monetary losses produced by the simultaneous interaction of two independent hazards in Lisbon’s city centre, i.e., earthquake and pluvial flood. Seismic hazard has been assessed in terms of macro-seismic intensity, while flood scenario allows for the prediction of water depth for different return periods through a hydrologic-hydraulic model in HEC-RAS software. The seismic and flood vulnerability of the urban investigated compound was evaluated through MCDM methodology—specifically, AHP and TOPSIS methods. A framework for multi-hazard analysis was subsequently developed, explicitly accounting for the interaction between the two hazards and their joint occurrence probabilities based on historical data from the case study area. The results demonstrate that multi-hazard losses are 108 M€ for a 2-year return period and 232 M€ for a 475/500-year scenario, emphasizing that floods contribute more across all return periods in the research area; however, for longer return periods, the earthquake contribution increases significantly. Full article

This study investigates the seismic behaviour of the Hüsrev Pasha Minaret, a historical masonry structure located in Diyarbakır, Türkiye, characterized by two distinct transition segments and material variation along its height. The dynamic features of the minaret were identified through ambient vibration tests, while material properties were estimated using non-destructive testing methods. A three-dimensional numerical model was then generated and calibrated based on the experimentally identified natural frequencies, achieving an average frequency difference of 2.04%. Nonlinear dynamic analyses were conducted using six earthquake time series scaled to three seismic hazard levels (DD-1, DD-2, and DD-3) defined in the Turkish Building Earthquake Code (TBEC-2018). The results indicate that the second transition segment is the most critical region in terms of damage concentration. Ground motions corresponding to the DD-1 level led to exceedance of the Collapse Prevention (CP) displacement limits, while DD-2 and DD-3 levels resulted in limited or near-limit responses. In addition, compression-only support conditions were found to influence the base shear response, whereas material transitions between basalt and limestone did not significantly affect the overall seismic behaviour of the minaret. Full article

Reliable forecasting of seismic activity trends is essential for regional seismic hazard analysis. Based on earthquake catalogs from 1500 to 2026, this study investigates the spatiotemporal evolution of seismic activity in the North-South Seismic Belt using a hybrid framework that integrates Wiener filtering and artificial neural networks. Seismic activity is modeled as a discrete-time stochastic process, and a time series of earthquakes with magnitudes ≥ 6.0 is constructed. Wiener filtering is applied to establish an optimal linear relationship between input and output under the minimum mean square error criterion, and multi-origin extrapolation is employed to predict earthquakes with magnitudes ≥ 7.0 over the next century. The results reveal several stable peaks or peak clusters that agree well with historical strong earthquakes, with prediction errors generally within approximately three years. Sensitivity analyses indicate that longer time series (∼500 years) and higher threshold magnitudes (≥6.0) enhance prediction stability, although the method shows limitations in spatial prediction. To address this issue, a 16–8–4 artificial neural network model is developed, and seismic sequence features are extracted using a sliding time window approach to perform both temporal and spatial forecasting. The artificial neural network achieves high accuracy in temporal prediction (maximum error ≈ 0.5) and outperforms Wiener filtering in spatial prediction, capturing the migration characteristics of seismic activity. The results further suggest that earthquakes with magnitudes ≥ 7.0 are more likely to occur within the latitude range of 30.5–33.0° N in the near future. Full article

Programs aimed at reducing the CO₂e footprint associated with the residential building stock should be informed by several key elements, including the expected evolution of the occupied housing stock, projected population dynamics driven by socio-economic and cultural factors, available implementation budgets, and the specific costs of intervention measures. However, in regions characterized by high seismic hazard, the occurrence of a major earthquake may substantially alter the projected outcomes of emission-reduction programs, as seismically vulnerable buildings may experience severe structural damage. This paper presents the results obtained by applying an integrated methodology for assessing the CO₂e footprint associated with residential buildings. The methodology accounts for emissions related to building operation (space heating), energy-renovation interventions, and seismic retrofitting works. While the proposed approach is applicable to other seismically exposed regions, the results presented herein refer specifically to the residential building stock in Romania and its local seismic conditions. The methodology integrates information on the existing building stock, the projected evolution of population and the built environment, energy consumption associated with building operation, changes in the energy fuel mix, construction practices across different historical periods with respect to energy efficiency and seismic protection, and the CO₂e footprint associated with energy renovation and seismic retrofitting. In addition, the analysis explicitly considers the potentially negative effects of a major earthquake, particularly the disruption of greenhouse-gas emission-reduction programs. The assessment is conducted at the building stock level and is based on combining building stock evolution with average, representative CO₂e intensity values for heating, energy renovation, and seismic retrofitting. The results demonstrate that when the sole objective is to reduce the CO₂e footprint associated with space heating, renovation of the energy fuel mix represents the most effective measure. At the same time, the analysis shows that the CO₂e footprint generated by construction works for energy renovation and/or seismic retrofitting represents only a small fraction of the emissions associated with building operation. The occurrence of a major earthquake is likely to jeopardize overall environmental objectives by increasing emissions related to building operation, energy renovation, reactive seismic retrofitting, and replacement of severely damaged buildings. Conversely, systematic preventive seismic retrofitting of the building stock does not lead to an increase in cumulative CO₂e emissions over the program implementation period. Full article

A key component of research on disaster risk in modern-age society in the inland areas of the Campania Region, southern Italy, was discovered in parish registers. Ecclesiastical archives, containing thousands of largely unpublished pages, served as a rich source of information on disruption and casualties. The parish registers preserved in these archives from the 16th century provide demographic records as well as notes on the most terrible events that affected society at the time. They include the catastrophic effects of seismic events recorded in this sector of the southern Apennines, an area characterised by high seismicity due to the complex dynamics of the convergence zone between the African and Eurasian plates. New findings reveal a more precise number and previously unreported deaths in several villages, confirming and suggesting some macroseismic intensities for the 1694 seismic event; moreover, further evidence was found for the hypothesised 1692 seismic event. A greater number of deaths was observed in some villages during the 1702 and 1732 events. Parish documents provided details about local construction techniques adopted after the well-known earthquake of 1732, including the use of more resilient materials and design modifications. Full article

This systematic literature review examines the growing relationship between resilience and sustainability within the built environment, specifically how climate change-induced hazards affect building and infrastructure performance requirements. To find conceptual similarities, differences, and complementarities between the two paradigms, the review integrates results from peer-reviewed research. The latest research indicates that even highly sustainable buildings may still be vulnerable to climate extremes, such as floods, heatwaves, earthquakes, and heavy rainfall, despite sustainability frameworks historically prioritizing reductions in environmental impacts, including carbon emissions, resource consumption, and waste. This review utilized the SPAR-4-SLR framework to analyze a total of 83 peer-reviewed publications. The findings suggest that resilience is concerned with a system’s ability to absorb, adjust, and recover from disruptions, whereas sustainability is mainly linked with long-term environmental impacts. Significantly, the literature shows a growing trend toward integrated S+R models, in which resilience parameters like structural robustness, redundancy, flexibility, and adaptive capacity are added to sustainability strategies. The review indicates that integrating comprehensive frameworks that equally handle environmental performance and hazard resistance is necessary to achieve climate-proof built environments. The paper contributes by identifying and integrating these two concepts, which improves the long-term sustainability of buildings and infrastructure while also ensuring long-term reliability. Full article

Armenia is located within the central segment of the Arabia–Eurasia continental collision zone and is exposed to significant seismic hazard. This study presents an updated probabilistic seismic hazard assessment (PSHA) for Armenia based on an integrated seismotectonic framework incorporating active fault data, paleoseismological evidence, and historical and instrumental seismicity. A hybrid seismic source model was developed by combining fault-based characteristic earthquake sources with distributed background seismicity. Hazard calculations were performed using the OpenQuake engine within a logic-tree framework to account for epistemic uncertainties in earthquake occurrence and ground-motion prediction. Ground motion was estimated using a weighted set of ground motion prediction equations (GMPEs). Peak ground acceleration (PGA) hazard maps were computed for several return periods, with emphasis on the 475-year return period (10% probability of exceedance in 50 years). The results indicate PGA values across Armenia ranging from approximately 0.2 g to 0.5 g, with the highest hazard levels in northwestern Armenia along the Pambak–Sevan–Syunik Fault System. Hazard deaggregation shows that seismic hazard in major Armenian cities is primarily controlled by shallow earthquakes with magnitudes Mw 6.8–7.4 occurring within ~30 km of urban centers. The results provide a scientific basis for seismic hazard assessment, zonation, and earthquake risk mitigation in Armenia. Full article

To investigate the influence of ambient temperature variations on the natural vibration characteristics and seismic responses of suspen-dome structures, a 1:20 geometric similarity dynamic scale model was designed using the symmetric suspen-dome roof of the Lanzhou Olympic Sports Center Gymnasium as the prototype. First, white noise excitation tests and seismic simulation tests were performed on the model, and the indoor ambient temperature was measured simultaneously. Subsequently, a corresponding numerical scaled model was developed using the ABAQUS 2024 finite element software, and its temperature was set according to the shaking table test measurements. Modal analysis and seismic time–history analysis were then performed, and the model’s natural frequencies and seismic responses (such as acceleration, displacement, and internal force) were compared with the shaking table test results, thereby validating the accuracy of the numerical model and confirming that the modeling approach reliably reproduces the natural frequencies and seismic responses measured in the tests. Finally, the ambient temperature of the numerical model was set according to the historical temperature data for Lanzhou. A comparative analysis was performed to examine the variations in the natural vibration characteristics and seismic responses of the suspen-dome structure under different temperature conditions. The result shows that, as the ambient temperature increases from −30 °C to 60 °C, the natural frequencies of the suspen-dome structure decrease by up to 21.8% (e.g., the third-order frequency drops from 9.423 Hz to 7.734 Hz), with low-order natural frequencies being the most significantly affected. Furthermore, under both unidirectional and three-dimensional earthquake excitations, the peak seismic responses increase markedly: acceleration increases by up to 35.5%, displacement increases by up to 88.3%, and internal force in critical members increases by up to 68.9%. Notably, structural members experiencing higher internal force responses demonstrate greater sensitivity to ambient temperature changes. These findings indicate that ambient temperature variation significantly reduces structural stiffness and amplifies seismic responses, providing a valuable reference for the seismic performance evaluation and safety design of suspen-dome structures in regions with large annual temperature fluctuations. Full article

To address load–energy dynamic coupling in heterogeneous unmanned aerial vehicle (UAV) emergency rescue, this paper proposes an energy-coupled heterogeneous UAV task allocation (EC-HUTA) model that explicitly characterizes nonlinear interdependencies among payload, velocity, and power consumption, minimizing aggregate mission costs subject to physical and temporal constraints. To tackle the resulting high-dimensional, nonconvex problem, we introduce a multi-strategy improved stellar oscillation optimizer (MISOO), establishing a closed-loop synergistic system through three coupled stages: (i) evolutionary game-theoretic strategy competition via replicator dynamics for adaptive exploration–exploitation balance; (ii) intuitionistic fuzzy entropy (IFE)-driven dimension-wise parameter control, where IFE calibrates global exploration intensity while dimension-specific crossover probabilities accommodate heterogeneous convergence; and (iii) memory-driven differential escape mechanisms modulated by historical memory parameters to evade local optima. Cross-stage coupling through IFE ensures state information flows across the “strategy selection-refined search-dynamic escape” pipeline. Coupled with a dual-layer encoding scheme, this framework ensures efficient feasible search. Ablation studies validate each mechanism’s contribution. Evaluations on CEC2017 benchmarks demonstrate MISOO’s superior convergence against six metaheuristics. Large-scale earthquake rescue simulations confirm that EC-HUTA/MISOO strictly adheres to nonlinear energy constraints while enhancing task completion and temporal compliance. These results validate the framework’s efficacy for time-critical emergency resource allocation. Full article

Masonry minarets constitute an important component of Islamic architectural heritage. Beyond their religious function, they stand as social and cultural landmarks reflecting the diversity of architectural styles and building techniques of the regions in which they are located. Historical minarets have demonstrated remarkable resilience against environmental degradation and aging; however, in seismically active regions, earthquakes pose a major threat to their integrity. Due to their slender geometry and material characteristics, these structures are particularly vulnerable to seismic effects. Many historical records document that minarets have suffered severe damage and collapse during earthquakes. This study presents a state-of-the-art review of seismic vulnerability assessments of masonry minarets. It concentrates on Southwest Asia and the Mediterranean, regions that are characterized by high seismic risk and a rich inventory of this structural typology. Currently employed approaches to the seismic analysis of minarets typically require substantial computational resources and expertise. Recognizing the need for rapid and accessible methodologies in place of them, this study proposes a Kinematic Limit Analysis framework that is suitable for fast vulnerability assessment of large-scale building stocks. This allows for the most critical structures to be identified for further scrutiny using more sophisticated approaches. Full article

Malawi lies within the southern segment of the East African Rift System and is exposed to infrequent but potentially damaging earthquakes. While recent advances in fault mapping, seismic monitoring, and hazard modelling have substantially improved scientific understanding of earthquake hazard in the Malawi Rift Zone, the practical reduction in seismic risk remains limited. This Perspective paper argues that earthquake resilience in Malawi is constrained less by scientific uncertainty than by challenges in integrating existing hazard knowledge into governance, planning, and preparedness. Drawing exclusively on published geological, geophysical, engineering, and policy literature, the paper synthesises evidence on seismic hazard, historical earthquake impacts, institutional preparedness, and barriers to the operational use of scientific risk assessments. An integrated, multi-pillar framework is proposed to support improved coordination between science, governance, infrastructure practice, and community preparedness. The framework is conceptual in nature and is intended to inform policy dialogue, prioritisation, and future empirical research rather than to provide a validated operational model. While grounded in the Malawian context, the insights presented are relevant to other low-income, rift-hosted regions facing similar challenges in translating earthquake science into effective disaster risk reduction. Full article

This study aims to determine the current seismic resistance of two masonry minarets that were severely damaged during the 6 February 2023 Kahramanmaraş earthquakes, while also evaluating whether a model-updating approach based on experimental dynamic characteristics can reliably capture the actual seismic behavior and collapse mechanism of such structures under real earthquake conditions. The dynamic characteristics of the minarets were identified using Operational Modal Analysis (OMA) based on previous in-situ vibration measurements. These characteristics were used to calibrate finite element models through a model-updating process employing Multi-Criteria Decision-Making (MCDM) methods. The initial modal analyses revealed discrepancies of up to 13.7% in natural frequencies and 9.7% in mode shapes. After applying MCDM methods to a wide set of model variants, these differences were reduced to 2.0% and 9.2%, respectively, improving the agreement between numerical and experimental results. Once the most representative models were obtained, nonlinear seismic analyses were performed using actual ground motion records from the earthquake. The results included evaluations of peak displacements, base shear forces, and principal stresses. The concentration of principal stresses near the transition zone showed good qualitative agreement with the observed collapse locations, indicating a reasonable consistency between numerical results and observed damage patterns. These findings demonstrate the value of integrating OMA-based model updating with MCDM methods and support a data-driven framework for assessing the seismic performance of historical masonry structures. Full article

This study focuses on the 1718 Tongwei earthquake (magnitude 7.5) and investigates the four counties of Tongwei, Gangu, Wushan, and Qin’an. By combining field surveys of earthquake damage and historical landslide data, we employed statistical analysis models to select ten influencing factors related to topography, geology, and seismic activity in the study area. We utilized kernel density analysis tools to statistically assess the number, area, and density of landslide points within different ranges of each influencing factor, identifying the most susceptible factor ranges for loess landslides triggered by the earthquake. The spatial distribution of these landslides under varying influences was visualized. Principal component analysis was conducted to explore the dominant factors affecting the spatial distribution of loess landslides, focusing on strongly correlated factors such as elevation, slope, and distance to rivers to further investigate their coupling effects. The results indicate that loess landslides are concentrated at elevations of 1300–1900 m, slopes of 10–20°, with a terrain fluctuation of 0–30 m, distances to rivers of 1200–1600 m, and proximity to active faults of 2–8 km, predominantly in grassland and farmland areas on south-facing slopes. Full article

Historic masonry towers are all around the world and play a significant role in shaping our built environment. Due to their slender shape, these towers are particularly vulnerable, as recent earthquakes have demonstrated. Many researchers have studied how these structures behave dynamically, with the aim of preserving their cultural value against the risks of damage or collapse. Lately, considerable attention has been paid to develop empirical formulas that estimate their fundamental frequency by considering geometric factors such as total height, reference base length, and effective height for constrained towers. These formulas are usually obtained using regression analysis on data from the technical literature, and so their reliability depends heavily on both the quantity and precision of available data. The variables chosen for calibrating these correlations are mainly determined by the information present in the literature; as a result, missing data can lead to underestimating the influence of some geometric aspects. To address this issue, the paper describes parametric analyses with a simplified model of masonry towers, i.e., the Euler–Bernoulli beam, aiming to show how sensitive the fundamental frequency is to different geometric and mechanical properties. These analyses show the importance of some parameters with respect to others and support the planning of experimental investigation needed for accurate predictions of a tower’s fundamental frequency. Full article

The Kahramanmaraş-centered earthquakes of 6 February 2023 (M_w = 7.7 and M_w = 7.6) caused widespread damage to historical masonry minarets across 11 provinces (Kahramanmaraş, Hatay, Adıyaman, Malatya, Gaziantep, Kilis, Şanlıurfa, Adana, Osmaniye, Diyarbakır, and Elazığ) in southeastern Türkiye. This study evaluates the seismic performance of a representative masonry minaret model using site-specific design response spectra derived from the current national seismic hazard map for each province. Finite element analyses were performed under various earthquake load combinations, and stress distributions and displacement responses were comparatively assessed. The results reveal pronounced regional variations in seismic demand. For instance, the design spectral acceleration (S_DS) and corresponding shear stress (S12) values in Gaziantep are approximately four times higher than those in Kilis, indicating a substantially greater seismic demand. Similarly, maximum tensile and compressive stresses consistently reach their highest levels in Gaziantep, Elazığ, and Hatay, whereas Kilis and Şanlıurfa exhibit the lowest stress values across all load combinations. In addition to numerical analyses, post-earthquake field observations from 29 historical minarets were evaluated, and typical damage patterns were identified. A strong correlation was observed between analytically predicted stress concentration zones, particularly at the transition segment, balcony level, and upper body, and the actual damage documented in the field. The study demonstrates that site-specific seismic parameters play a decisive role in the structural response of masonry minarets and that regional differences must be explicitly considered in seismic assessment and conservation strategies. These findings provide a quantitative basis for prioritizing strengthening interventions and improving the resilience of historical structures against future earthquakes. Full article