Search

Southwestern British Columbia in Canada has a high likelihood of facing significant earthquake threats in the future. It is exposed to significant seismic and tsunami hazards, originating from the Cascadia subduction zone and shallow crustal and deep inslab earthquakes. This study presents a new probabilistic earthquake-tsunami loss model for the Cascadia subduction zone by focusing on the District of Tofino, British Columbia. The earthquake occurrence and rupture models for the Cascadia subduction zone are developed by incorporating the time-dependency of earthquake occurrence and by adopting a stochastic source modelling approach, which allows for consideration of heterogeneous earthquake slip distributions. The results produce single-hazard and multi-hazard exceedance probability loss curves for earthquakes and tsunamis from the Cascadia subduction zone. In addition, earthquake risks due to other seismic sources are integrated with the multi-hazard loss curves due to the Cascadia events. In this way, a complete financial exposure from all major seismic and tsunami sources is evaluated. These loss curves can be used for determining the insurance rates for multi-hazard and multi-source risk coverage. The results are beneficial for providing more risk financing options via insurance against the future Cascadia and other seismic events. [ABSTRACT FROM AUTHOR]

The intensity of typhoons affecting the Korean Peninsula has been rapidly increasing, resulting in significant damage. Notably, this intensification correlates with the rise in Sea Surface Temperature (SST) in the western Pacific Ocean and surrounding sea areas, where typhoons that impact the Korean Peninsula originate and develop. The SST in these regions is increasing at a faster rate than the global average. Typhoon-related meteorological disasters are not isolated events, such as strong winds, heavy rains, or storm surges, but rather multi-hazard occurrences that can affect different areas simultaneously. As a result, preparation and evaluation must address multi-hazard disasters, rather than focusing on individual weather phenomena. This study develops the Typhoon Ready System (TRS) to improve impact-based forecasting in Korea, in response to the growing threat of multi-hazard weather disasters. By providing region-specific pre-disaster information, the TRS enables local governments and individuals to better prepare for and mitigate the impacts of typhoons. The system will be continuously refined in collaboration with the U.S. Weather-Ready Nation (WRN), which possesses advanced impact forecasting capabilities. The findings of this study offer a crucial framework for enhancing Korea's ability to forecast and respond to the escalating threats posed by typhoons. By utilizing the TRS, it will be possible to assess the risks of various multi-hazard weather disasters specific to each region during the typhoon forecast period, and the relevant data can be efficiently applied at both the individual and local government levels for typhoon prevention efforts. The system will be continuously improved through cooperation with the U.S. WRN, leveraging their advanced impact forecasting systems. It is expected that the TRS will enhance the accuracy of typhoon impact forecasts, which have been responsible for significant damage in Korea. [ABSTRACT FROM AUTHOR]

Concepts, approaches and frameworks for assessing the impacts of climate change are evolving quickly. Due to their particular geographic location, proximity to oceans, concentration of populated regions, and infrastructure, coastal communities are particularly sensitive to the effects of climate change. The present study aims to develop a thematic map based on the CID (climatic impact-drivers) framework proposed in the assessment report-6 of the Intergovernmental Panel on Climate Change (IPCC) to evaluate the climate change’s physical hazards in the coastal districts of India. The study points out that West Bengal and Odisha are the two states with the highest cyclone hazard index values making them most vulnerable to cyclones. At the same time, Kerala, Andhra Pradesh and West Bengal respectively fall in the extremely severe category of flood, heatwave and shoreline change hazards. The maritime state of Gujarat along with Diu and Daman experiences maximum severity for the sea level rise hazard. The multi-hazards index developed in the study by considering 14 threshold-based CID indices showed that the coastal state of Andhra Pradesh has the highest proneness to the physical hazards due to climate change [ABSTRACT FROM AUTHOR]

Drawing on a case study from Ternate Island, a densely populated volcanic island in Eastern Indonesia, this research illustrates how multi-hazards and extreme weather events are likely to compound and cascade, with serious consequences for sustainable development in small island context. At the heart of Ternate Island sits the active Gamalama volcano, posing a constant eruption threat. Its location within the Ring of Fire further exposes the island to the risks of tsunamis and earthquakes. Additionally, the island's physical features make it highly susceptible to flooding, landslides, and windstorms. Rapid urbanization has led to significant coastal alterations, increasing exposure to hazards. Ternate's small-island characteristics include limited resources, few evacuation options, vulnerable infrastructure, and inadequate resilience planning. Combining GIS multi-hazard mapping with a structured survey in 60 villages in Ternate, this case study investigates the multi-hazard exposure faced by the local population and land coverage. The findings suggest significant gaps between village chiefs' perceptions of the types of hazards and the multi-hazard assessment in each village. Out of 60 village chiefs surveyed, 42 (70%) are aware of earthquake risks, 17 (28%) recognize tsunami threats, and 39 see volcanoes as a danger. GIS assessments show that earthquakes could impact all villages, tsunamis could affect 46 villages (77%), and volcanoes could threaten 39 villages. The hazard map indicates that 32 villages are at risk of flash floods and 37 are at risk of landslides, and extreme weather could affect all villages. Additionally, 42 coastal villages on Ternate Island face potential extreme wave and abrasion disasters, but only 18 chiefs acknowledge extreme weather as a threat. The paper argues that addressing the cognitive biases reflected in the perceptions of community leaders requires transdisciplinary dialogue and engagement. [ABSTRACT FROM AUTHOR]

Considering the increasing impact of natural hazard-related disasters in Malaysia, understanding and evaluating integrated disaster risk must consider multi-hazard and multidimensional vulnerability at the local level, particularly in developing industrial nations like Malaysia. Therefore, this study proposes an improved methodology for conducting an integrated disaster risk assessment index (IDRI) mapping to measure disaster risk within local administrative boundaries in Malaysia. In this study, multi-hazard spatial overlapping combined two common hazards in Malaysia, which are floods and landslides. This study used multidimensional vulnerability, which encompasses six dimensions, 16 subdimensions, and 54 indicators. Researchers applied this approach in three urban districts of Selangor, Malaysia: Sepang, Kuala Langat, and Hulu Langat, which are located within the Langat River catchment and consist of 17 subdistricts. Overall, 32.9% of the total study area was found to be at risk, with 4.3% in the very high-risk area. In comparison with the latest flood events in 2021, the IDRI components were highly correlated with disaster impact. In conclusion, the contribution of this study provides a novel perspective on disaster risk assessment by addressing several types of hazards and multidimensional vulnerability, as compared to the previous methodology focusing on a single hazard and a physical vulnerability factor.

The multidisciplinary approach outlined in this paper aims to assess the correlation between geophysical and social vulnerability for disaster risk reduction. To achieve this, two multi-criteria methods based on Geographic Information Systems (GIS) techniques have been integrated to assess the risk to natural hazards in the North-East Development Region. The Analytical Hierarchy Process (AHP) was utilized to conduct a comprehensive hazard analysis, including floods, landslides, and earthquakes. The Principal Component Analysis (PCA) method was applied to examine the spatial distribution of social vulnerability at the Local Administrative Unit (LAU level), utilizing 24 variables to generate 6 principal components. Based on these results a Regional Risk Index (RRI) was developed using the bivariate method, combining the multi-hazard distribution with social vulnerability. The results showed that the north-eastern part of the region presents the highest risk, encompassing 10.68% of administrative units. These results can contribute to the design of risk reduction programs and policies.

Natural disasters are becoming increasingly regional, frequent, and complex. Semi-quantitative risk assessments based on risk indices or relative risk levels lack quantitative parameters to characterize losses adequately. This study focuses on earthquakes and geological disasters, quantitatively assessing the risk of probable maximum loss (PML) from multi-hazard on the Tibet Plateau (TP) in terms of both absolute and relative values. The results indicate that total PML from multi-hazard on the TP is estimated at 465.5 billion CNY, with a relative value of 5.3%. The total loss value of towns with very high absolute PML is estimated at 254.8 billion CNY, while the relative loss value of towns with very high relative PML is 25.1%. Towns with high absolute value of PML for multi-hazard may have higher fixed asset values, while those with high relative value imply higher vulnerability. Adjusting building structures and reducing the vulnerability of buildings could effectively mitigate the risk of disaster losses caused by multiple hazards.

An improved understanding of tunnel fire dynamics is crucial for fire and life safety. This work highlights the significance of Computational Fluid Dynamics (CFD) techniques in addressing the interaction between tunnel fires and rainfall. The discrete phase model based on the Lagrangian approach is applied to simulate raindrops, while the species transport model is used to simulate fuel combustion. A numerical model is established to investigate the impact of rainfall on tunnel fires, and the correctness of the model is verified by comparing the results to model-scale tunnel experiments. Results show that the raindrops increase the local pressure in the rainfall area, creating a pressure difference between the rainfall tunnel portal and the no-rain portal, which leads to longitudinal airflow inside the tunnel. This rain-induced airflow prevents smoke from moving toward the rainfall tunnel portal and decreases the smoke height near the no-rainfall portal. Correlations between the local increased pressure, induced-airflow velocity, and rainfall parameters are proposed. Besides, the model is scaled up to full-size, and real-scale tunnel fires under the influence of rainfall are evaluated. Findings draw attention to tunnel fire dynamics under extreme weather conditions for improved fire safety and evacuation strategies.

Volcanoes produce a wide variety of hazards across varying spatial and temporal scales. When data are scarce on past eruptions and hazards, it can falsely imply low hazard recurrence and create challenges for robust hazard and risk assessment. Data quality and quantity vary considerably across different regions, volcanoes, and eruptions. Yet, there is a need for regional to global scale information on volcanic hazard and risk, where consistent and reproducible methods are applied. Such information is used by international stakeholders to inform funding priorities, risk reduction policies, and to highlight data and knowledge gaps, contributing towards the Sendai Framework's Sustainable Development Goals. Challenges in gathering this information can be most problematic where large populations are exposed to potential volcanic hazards but there are few comprehensive eruptive histories, as in sub-Saharan Africa. Here, we present a unique study to evaluate hazard and exposure for nine volcanoes in Ethiopia, Kenya and Cabo Verde, as part of an international project to develop multi-hazard Disaster Risk Country Profiles. We applied a two-stage expert elicitation process to volcanoes for the first time, and coupled the results with vent mapping, numerical hazard modelling, and GIS analysis of eight exposure categories to identify where high volcanic hazard and exposure coincide. Testing the sensitivity of our findings to input assumptions, to better understand where uncertainties lay, showed that improving our knowledge of past eruption volumes, frequencies, and dates was key to reducing uncertainty. Expert elicitations proposed that Fogo, Cabo Verde, is the most likely to erupt (eruption on average every 25 years), while Fentale (Ethiopia), Longonot and Suswa (Kenya) were elicited to have the greatest probability for a large explosive (VEI ≥ 4) eruption (on average every 400 years). Menengai and Longonot produce the larger exposure values across most VEI scenarios and categories of exposure, but population and GDP exposure was also large for more distal tephra fall and flows at Corbetti and Suswa, with order of magnitude increases expected between 2010 estimates and 2050 projections. Potentially high impact scenarios include tephra being dispersed across large cities (e.g. Nairobi, 55 km from Suswa) and key infrastructure (e.g. geothermal power station ∼2.5 km from Aluto), as well as important tourist destinations, seats of government and emergency management operations (e.g. islands east of Fogo). This study provided the first hazard and exposure assessment of its kind for these volcanoes and drew attention to volcanic risk at the levels required to inform policy and future in-country funding opportunities.

While research on natural hazards in Nepal has primarily focused on the consequences of individual hazards within an area, it is also essential to analyze the probable occurrence of several types of natural hazards and their interaction, i.e., Multi-hazard assessment. In light of this, the study conducted a Multi-Hazard Risk Assessment of the proposed capital city of Lumbini province, which covers 14 wards from three municipalities. The four prevalent hazards in the area, i.e., flood, landslide, debris flow, and forest fire, have been considered in the study, which includes generating individual susceptibility maps using different geospatial and modeling techniques. The vulnerability and risk assessment was done on a ward level and considered physical, social, economic, and environmental vulnerability indicators. The results on the multi-hazard susceptibility map show that 29.36% of the area was at low susceptibility, while the medium and high zones comprised 46.16% and 24.46% of the total area, respectively. Wards 2, 3, and 7 of Rapti are highly vulnerable, while Ward 8 of Sitganga and Ward 9 of Rapti are the least vulnerable. Moreover, wards 1, 2, and 3 are at high risk to the vulnerability parameters, while ward 8 of Sitganga is at the least risk. The high-risk areas are on the foothills of the Siwalik range, which are prone to landslide, debris flow, and forest fire hazards, as well as are on the bank of West Rapti River, which marks them as potential flood hazard zones. The capital city of Lumbini province is fast developing. Therefore, the results derived from this study assist in identifying potential risk zones to consider while creating a master plan for the area.

Compound flooding (CF) events, driven by coincident/concurrent and mutually reinforcing factors such as heavy rainfall, storm surges, and river discharge, pose severe threats to coastal communities around the Globe. Moreover, the exacerbating influence of climate change and sea-level rise further amplifies these risks. This study delves into the complex and multifaceted issue of compound coastal flooding in two freshwater-influenced systems on the Gulf Coast of the United States - Southeast Texas and South Alabama. We first conduct a robust statistical analysis to evaluate the significance of nonstationarity, multi-dimensionality, and non-linearity of interactions among various drivers of CF. Second, to assess the extent to which current flood resilience policies and guidelines account for these characteristics of CF events, we perform a critical review of existing policy documents. The results of the statistical analysis reveal significant compounding and shifts in the statistics of flood drivers that emphasize the pressing need for a multi-mechanism, nonstationary approach to flood hazard assessment. We also found an evident lack of appropriate language/recommendation in policy documents of solid tools that systematically take non-stationarity, multi-dimensionality, and non-linearity of CF into account. By identifying the gaps between current policy measures and the detected complexities of CF, we seek to provide insights that can inform more effective flood resilience policies and design guidelines. Through this robust analysis, we aspire to bridge the divide between research and policy. [ABSTRACT FROM AUTHOR]

Safety and resilience of learning facilities are critical issues in disaster-prone areas, in which natural hazards can pose significant risks to students, staff, and infrastructures. To address these issues, the SPRINT-Lab researchers at the University of Udine, under the UNESCO umbrella, conceived and developed the Visual Inspections for defining Safety Upgrading Strategies (VISUS) methodology. VISUS consists of visual inspections of school facilities, with the aim of providing decision-makers with evidence-based recommendations for upgrading safety and resilience in learning environments. This paper summarises the key features of the VISUS methodology and illustrates the progression of its application in the last decade, achieved through its implementation in pilot projects promoted by the UNESCO Unit on disaster risk reduction (DRR). In particular, the paper showcases the results achieved from the application of VISUS in various projects worldwide, and provides examples on how these results can be used to support decision-makers in formulating plans and strategies to improve school safety. Furthermore, the paper highlights the knowledge acquired and conclusions drawn from the various VISUS projects and provides insights into the practical implications of its implementation within the UN DRR policies, so as to improve the safety of learning facilities. [ABSTRACT FROM AUTHOR]

Floods and landslides cause continuous damage to ecosystems, infrastructures, and populations. Particularly, the occurrence and the existence of different natural hazards in the same territory highlight the need to improve risk mitigation strategies for local authorities and community resilience solutions for inhabitants. Analyzing and mapping social vulnerability provides information about the main features of a specific community to deal with natural events. Specifically, the interaction between multi-hazards and the socio-economic environment suggests multidisciplinary assessments that merge the physical and the socio-economic features of the affected territories, providing a useful approach to support multi-risk reduction planning. In this context, the article focuses on integrating landslide and flood hazard scenarios with social vulnerability in the Basilicata Region (southern Italy) at the census tract level. Thirteen municipalities were chosen as multi-hazard hot spots, while open-source platforms were selected for hazard and social vulnerability data collection and analyses. A geographic information system (GIS)-based approach was applied to combine different hazard scenarios with social vulnerability distribution among 1331 census tracts to detect the most vulnerable sub-municipality areas that need special attention in multi-risk reduction strategies. The results are presented in the form of maps, which provide a relevant suitable tool in local emergency planning. [ABSTRACT FROM AUTHOR]

Human-induced climate change has profound effects on extreme events, particularly those linked to global warming, such as heatwaves, droughts, and wildfires. These events disrupt ecosystems, emphasizing the imperative to understand the interactions among them to gauge the risks faced by vulnerable communities. Vulnerability levels vary primarily based on a community's resources. Rural areas, especially in the Mediterranean region of Europe, are experiencing acute depopulation, creating a complex situation affecting various aspects of society, from economic declines to cultural heritage loss. Population decline in rural regions weakens resources, leading to the abandonment of built environments, fostering desertification, and elevating the risk of wildfires. Communities undergoing this deterioration process become exceptionally vulnerable, especially when dealing with and recovering from extreme natural phenomena. This review offers insights into the dynamics of these hazards and the predominant challenges in rural areas. By focusing on a topic that has received limited attention, the aim is to inform future research initiatives, ultimately improving risk assessment and mitigation strategies for these vulnerable communities. [ABSTRACT FROM AUTHOR]

Disaster Risk Management (DRM) is complex due to interacting climate risks from interacting hazards and sectors. We develop a synthetic multi‐risk test case to explore the effects of these interactions on decision‐making under deep uncertainty. The test case accounts for changes in hazard impacts and occurrence frequency due to interactions between floods and droughts. Interactions between the shipping, housing and agricultural sectors are considered as well. We use this test case to explore the utility of the Dynamic Adaptive Policy Pathways for Multi‐Risk (DAPP‐MR) framework. DAPP‐MR has been introduced to assess DRM policies' effectiveness under deep uncertainties and to develop integrated adaptive strategies considering interactions across hazards, sectors and time. With the test case, we show that the stage‐wise approach of DAPP‐MR, which gradually increases the complexity of the analysis, can facilitate the evaluation process. Earlier stages of the analysis can be used to establish the direct cause‐effect relations, later stages allow us to identify whether additional interacting factors have a significant effect on the direct cause‐effect relations. As a result, decision‐makers can gain insights into dependencies and their relevance for developing short‐to long‐term strategies under deep uncertainty. We show that multi‐risk interactions can lead to non‐linear effects that influence the outcome of the policy analysis, for example, the indirect influence of a decision in one sector on another. Future work could investigate further improving the operationalization of this staged approach as well as extending the set of uncertainties, dynamics and decision‐rules accounted for in the multi‐risk test case. Plain Language Summary: This paper addresses the complex challenge that many regions face when dealing with multiple interconnected disasters, like floods, droughts and earthquakes. Traditional Disaster Risk Management methods often fall short, particularly in long‐term planning that considers factors such as climate change. We apply a step‐by‐step approach known as "Dynamic Adaptive Policy Pathways for Multi‐Risk (DAPP‐MR)" to assist decision‐makers in better understanding and planning for these intertwined risks over time. This paper employs a hypothetical test case where different sectors (e.g., agricultural sector) seek effective ways to prepare for and respond to flood and drought risks. The DAPP‐MR method facilitates this by breaking down the process into smaller, more manageable steps. This approach allows for an easier understanding of the direct effects of disasters and gradually incorporates more complex interactions between different risks. Our findings suggest that this step‐by‐step method can aid decision‐makers in grasping the connections between various factors and their significance in formulating both short‐ and long‐term strategies. The study also reveals that interactions between different risks can produce unexpected, nonlinear effects, adding complexity to the interpretation of policy outcomes. Key Points: A multi‐risk modeling case with interacting hazards and sectors is created to explore effects for decision‐making under deep uncertaintyDynamic Adaptive Policy Pathways for Multi‐Risk has proven effective for pathway analysis to grasp interactions and their relevance through a structured, stage‐by‐stage approachMulti‐risk interactions can alter the decision‐making outcome because of changes in performance or timings of potential pathways [ABSTRACT FROM AUTHOR]

Global climate change poses an increasingly dire threat to habitats, livelihoods, and communities worldwide. This cross-sectional study has tried to examine the state of improved shelter facilities in India, utilizing the comprehensive methodology outlined by UN-Habitat and NFHS-5 data. The findings of our research alarm that 39.3% of India's population lacks access to improved shelter. Moreover, a significant disparity in the availability of improved shelter facilities is observed across various states in India. In regions prone to hazards such as floods and earthquakes, there is a considerable lag in terms of improved shelter provisions. On the other hand, non-hazardous areas demonstrate relatively higher rates of access to improved shelter. Our study reveals a marked distinction between improved shelter and hazard-free improved shelter estimates. In India, only 40.6% of the population can be considered safe from the perils of floods, landslides, and earthquakes. However, the situation is considerably worse in rural areas, where both improved shelter and hazard-free improved shelter are scarce. This highlights the urgent need to adopt hazard-free improved shelter as a more refined metric for housing, as it can prove instrumental in guiding effective planning and policymaking initiatives. To ensure a risk-free living environment for future generations, it is imperative to undertake micro-level vulnerability mapping and conduct comprehensive risk assessments for various hazards. Furthermore, the government must take proactive measures to promote resilient housing infrastructure as a crucial component of sustainable development. [ABSTRACT FROM AUTHOR]

Potential losses and damages caused by natural hazards in the future are essential information that the public and stakeholders need to understand. Banyuwangi Regency, located at the eastern most tip of Java Island, borders the Indian Sea on the south and the Bali Strait on the east. These areas are hazardous because they are at increased risks of severe weather with frequent occurrences of volcanic eruptions and tsunamis. The hazards and possibilities of the future can be detected through a geomorphological map. This map provides several details about the regional characteristics of Banyuwangi and information on the geomorphological configuration related to natural hazards and disaster-prone areas. Such information can be of use to the people, the government and stakeholders alike. Following the geomorphological approach in this study, we classified landforms using four aspects, such as (1) morphology; (2) morphogenesis; (3) morpho-arrangement and (4) morpho-chronology. The data sources used are geological maps, DEM Alos Palsar and Google Satellite imagery for interpretative analysis. In this study area, the landform mapping identified 15 different landforms. There are eight landforms with landslide hazards and three with tsunami hazards. The landform with a landslide hazard has a common morphological condition which is hilly morphology. The landform with tsunami hazards as the main triggering factor has a plain morphology and an elevation below 50 m above sea level. Those conditions allow the tsunami surge to run up to reach further areas until it reaches an undulating or hilly morphology. Contribution: The results of this research are expected to inform the multi-hazards sources based on the geomorphological conditions in the Banyuwangi Regency. With such information, the government and the people can increase their ability to cope with disaster strikes in the future.

Multi-hazard events have received attention globally due to their increasing frequency and severity in recent years. The coastal region of Bangladesh is particularly vulnerable to multi-hazard events induced by tropical cyclones (TC), including coastal flooding, extreme precipitation, extreme winds, and salinity intrusion. These events inflict substantial damage on human lives and property, yet there has been limited effort to quantitatively assess the associated risks. This study aims to investigate the spatial distribution of multi-hazard risks stemming from TC events, employing a Fuzzy Analytic Hierarchy Process (FAHP) approach. Risk is assessed in relation to hazard, exposure, vulnerability, and mitigation capacities in the study area. Various indicators are selected to define each of these four risk components, with weights determined through expert input for FAHP modeling. The results indicate that more than 50% of the area faces multi-hazard risks, with the hazard component exhibiting the highest degree of risk association, followed by exposure, vulnerability, and adaptive capacity. Storm surge-induced flooding is identified as the most prominent hazard during TC events, followed by intense precipitation, extreme winds, and salinity intrusion. Areas characterized by high population density, a large number of vulnerable populations (e.g., those under 15 years or over 65 years), low elevation, and underdevelopment are found to be the most risk prone. Notably, the presence of hospitals, cyclone centers, and effective warning systems in proximity to an area enhances its potential to withstand multi-hazard impacts. Among the 19 coastal districts, Cox's Bazar and Feni are identified as the most risk prone. The framework and findings presented in this study offer valuable insights for the development and prioritization of multi-hazard risk mitigation policies by identifying the most vulnerable zones and the associated risk factors.

The intensity of typhoons affecting the Korean Peninsula has been rapidly increasing, resulting in significant damage. Notably, this intensification correlates with the rise in Sea Surface Temperature (SST) in the western Pacific Ocean and surrounding sea areas, where typhoons that impact the Korean Peninsula originate and develop. The SST in these regions is increasing at a faster rate than the global average. Typhoon-related meteorological disasters are not isolated events, such as strong winds, heavy rains, or storm surges, but rather multi-hazard occurrences that can affect different areas simultaneously. As a result, preparation and evaluation must address multi-hazard disasters, rather than focusing on individual weather phenomena. This study develops the Typhoon Ready System (TRS) to improve impact-based forecasting in Korea, in response to the growing threat of multi-hazard weather disasters. By providing region-specific pre-disaster information, the TRS enables local governments and individuals to better prepare for and mitigate the impacts of typhoons. The system will be continuously refined in collaboration with the U.S. Weather-Ready Nation (WRN), which possesses advanced impact forecasting capabilities. The findings of this study offer a crucial framework for enhancing Korea’s ability to forecast and respond to the escalating threats posed by typhoons. By utilizing the TRS, it will be possible to assess the risks of various multi-hazard weather disasters specific to each region during the typhoon forecast period, and the relevant data can be efficiently applied at both the individual and local government levels for typhoon prevention efforts. The system will be continuously improved through cooperation with the U.S. WRN, leveraging their advanced impact forecasting systems. It is expected that the TRS will enhance the accuracy of typhoon impact forecasts, which have been responsible for significant damage in Korea.

The stochastic response of multi-story buildings isolated by laminated rubber bearing (LRB), lead-rubber bearing (N-Z system), friction pendulum system (FPS), and resilient-friction base isolator (R-FBI) is investigated under the independent multi-hazard scenario of earthquake ground motion (EQGM), wind load (WL), and blast-induced ground motion (BIGM), which are considered as uncertain inputs. A polynomial regression-based Monte Carlo simulation (PRBMCS) is proposed to enable computationally efficient fragility assessment of base-isolated buildings. The suitability of the PRBMCS for stochastic assessment of the base-isolated buildings is compared with the conventional Monte Carlo simulation (MCS), response surface method (RSM) and Cloud analysis. The fragility curves obtained using the PRBMCS are in good agreement with that of the MCS relatively. The study includes: the effects of the characteristic parameters of the four base isolators on the fragility of the base-isolated buildings under the three hazards; influence of the extent of uncertainty in the excitations; and comparison of fragilities of the base-isolated and fixed-base buildings. Notably, the influences of characteristic parameters of the isolators on the fragility of the base-isolated buildings are different under the three hazards. The differences in the stochastic behaviour under the different hazards could have contradictory influences on the selection of isolation parameters. [ABSTRACT FROM AUTHOR]

Purpose: This study is an attempt to illustrate and discuss multi-hazard interactions in vibration control of long-span bridges subjected to wind and seismic loads. Such bridges, being flexible structures, are inherently vulnerable to wind loads. However, some response parameters of such bridges, for example, tower and deck acceleration, can be significant during large earthquakes which produce ground motions with low-frequency content. Methods: To illustrate this problem, a case study of the Runyang Suspension Bridge (RSB) is used. A finite element model of the bridge is created and verified against published literature. A set of ground motions from large worldwide earthquakes and spatially varying wind velocity time series, simulated as a realization of a random field, are used to evaluate the bridge's dynamic response with and without control devices. The control devices applied in this study are passive-tuned mass dampers (TMDs). Careful investigation of the uncontrolled response of the bridge shows that while wind load is mainly important for the displacement of the bridge deck, seismic loads can induce significant acceleration of the tower and the deck. Since the response of the tower and the deck are coupled at some higher modes of vibration, seismic action, although most critical for the tower, is also relevant for deck acceleration. These observations indicate the need for a multi-performance-based control strategy. Results: It is found that TMDs optimal for reducing seismic-induced deck acceleration can lead to amplification of wind-induced deck displacement. At the same time, TMDs optimal for reducing wind-induced displacement response are, in some cases, harmful to seismic-induced deck acceleration. These results clearly show multi-hazard interaction in control performance. Conclusions: To account for this problem, a control strategy for the deck and tower's seismic and wind responses is investigated. This consists of TMDs placed at the top of each tower and 4 TMDs placed on the deck. By tuning the TMDs to different vibration modes of the bridge, the system is shown to be effective for both seismic and wind actions. [ABSTRACT FROM AUTHOR]

Unbonded fibre-reinforced elastomeric isolator (UFREI) as laminated elastomeric isolator is a relatively new approach to base-isolation devices with improved efficiency, cost-effectiveness and ease. Base-isolated structures become more susceptible to wind loads due to an increase in the period of the structure, and UFREIs have been found to be effective in mitigating occasional wind loads on isolated structures with the help of supplemental devices. This study investigates the multi-hazard response of benchmark structures isolated using UFREIs and subjected to several hazards over a period of time. Hazard timelines consisting of probable prominent seismic and long-term wind events are generated for the analysis. Since fibre layers in UFREI are flexible in bending, the bond strength demand between elastomer and fibre layer decreases by a huge margin, which delays any delamination failure. Thus, fatigue losses in the elastomer layers are used to characterise the damage induced in the UFREI due to multiple hazards throughout the timeline. Maximum principal strain in elastomer layers at various displacement amplitudes is calculated using finite-element modelling, and it is further used to characterise the fatigue damage in elastomer layers. The final fatigue life of the designed UFREI is predicted using the obtained damage indices. [ABSTRACT FROM AUTHOR]

River-crossing bridges in seismically active regions are typically susceptible to two natural hazards – earthquakes and floods. For such bridges, design parameters related to piers may play major roles in bridge multi-hazard performance. In this study, the same was explored for key bridge design parameters – the aspect ratio and longitudinal reinforcement ratio of piers and the differential ground elevation between multiple bents. The multi-hazard condition in the southeast of Nepal was considered as the test-bed hazard condition. The regional seismic hazard was represented using a suite of earthquakes generated based on regional seismic design spectra. Due to the flood hazard in the region, expected pier scour of investigated bridges was estimated from 100-year flood discharge (including climate change projection) in the Koshi River, Nepal. Three-dimensional finite-element models of the chosen bridges, with and without scour and with ±10% variations in the stated design parameters, were developed. Fragility and risk curves of the bridges were developed and compared in order to assess the relative influence of the design parameters on bridge performance. It was found that the aspect ratio and longitudinal reinforcement ratio of piers can significantly influence the multi-hazard performance of riverine bridges. The findings also demonstrate how design parameters may be revised to perform risk-targeted multi-hazard design of bridges. [ABSTRACT FROM AUTHOR]

Bridges are key parts of transportation networks and hence, their post-hazard condition is vital for the recovery of the regions affected by natural hazards. However, the fact that they are often subjected to more than one destructive natural hazard during their life span resulting in accumulated damage that may influence their capacity has attracted relatively little research interest, while almost no design standards take it into consideration. The multiple hazard events may be successive single events, separated by considerable time intervals (e.g. an earthquake followed by a flood event), combined or cascading multiple-hazard events (e.g, landslide after an earthquake), or even simultaneous events. The main objective of this study is to propose an effective framework for the development of multiple-hazard fragility curves of bridges considering the effect of subsequent events and taking into account different possible damage scenarios of the bridge critical components, i.e. piers, bearings and the abutment-backfill systems. In this framework, the effect of the damage level of the critical components and their interdependence on the fragility assessment for multiple events is examined and compared with the bridge fragility for single events. A pilot case study is also included in the present work, aiming to highlight the effect of the initial damage state on the final fragility estimate of a typical riverine bridge. [ABSTRACT FROM AUTHOR]

This work aims to describe, classify, and analyze the occurrence of selected natural multi-hazards, specifically pluvial floods and sinkholes, affecting a district in the urban area of Rome, Italy. The procedure is based on a robust geological, geomorphological, and hydrogeological analysis performed using data collected and archived for the scope. The susceptibility is calculated based on geo-hydrological and geomorphological factors, as well as the occurrence of flooding and sinkholes. The areas prone to each single hazard were combined and put into the context of multi-hazard assessment by overlaying the susceptibility with buildings and population data. The resulting map shows that 50% of buildings (6215 inhabitants) are in an area of multi-hazard susceptibility; among these, 25% are in the highest multi-hazard classes (4 and 5). These areas are named "multi-hazard hotspots" because they are affected by many hazards with associated higher impacts. This study demonstrates that a comprehensive approach that combines the examination of geology, hydrogeology, modifications to historical morphology, and the occurrence of geological disasters is effective for mapping geohazards in urban areas and identifying locations with multiple hazards. A multi-hazard hotspot map can be used as a tool for planning actions aimed at reducing the vulnerability and exposure level of the urban population. [ABSTRACT FROM AUTHOR]

Landslide dams, forming when a landslide blocks a watercourse, are significant components of slope-river systems. Dams can fail suddenly and catastrophically, threatening downstream populations and structures. So it is important to understand where they could form, how long they persist in the landscape, and the extent of downstream inundation once they fail. To investigate dam formation, longevity, and stability effectively in Aotearoa New Zealand, we present version 1.0 of the New Zealand Landslide Dam Database (NZLDD). The database includes compilation, mapping, and/or remapping of 1036 dams, including those generated by the 2016 Kaikōura Earthquake. A representative subset of 265 dams was selected to analyse dam stability and breaching in detail (ongoing work). The database architecture, description of datasets included, attribute definitions, and some summary statistics are presented here. Many dams in the database have formed in greywacke bedrock terrain, by earthquake-triggered rock avalanches, falls, and slides. Most are small (Dam Type I—small dam that does not reach opposite valley side), and have since failed and no longer impede or impound water. The NZLDD represents a significant increase in catalogued landslide dams—almost doubling the existing number of known and studied dams worldwide. [ABSTRACT FROM AUTHOR]

Different approaches exist to describe the seismic triggering of rockfalls. Statistical approaches rely on the analysis of local terrain properties and their empirical correlation with observed rockfalls. Conversely, deterministic, or physically based approaches, rely on the modeling of individual trajectories of boulders set in motion by seismic shaking. They require different data and allow various interpretations and applications of their results. Here, we present a new method for earthquake-triggered rockfall scenario assessment adopting ground shaking estimates, produced in near real-time by a seismological monitoring network. Its key inputs are the locations of likely initiation points of rockfall trajectories, namely, rockfall sources, obtained by statistical analysis of digital topography. In the model, ground shaking maps corresponding to a specific earthquake suppress the probability of activation of sources at locations with low ground shaking while enhancing that in areas close to the epicenter. Rockfall trajectories are calculated from the probabilistic source map by three-dimensional kinematic modeling using the software STONE. We apply the method to the 1976 MI = 6.5 Friuli earthquake, for which an inventory of seismically-triggered rockfalls exists. We suggest that using peak ground acceleration as a modulating parameter to suppress/enhance rockfall source probability, the model reasonably reproduces observations. Results allow a preliminary impact evaluation before field observations become available. We suggest that the framework may be suitable for rapid rockfall impact assessment as soon as ground-shaking estimates (empirical or numerical models) are available after a seismic event. [ABSTRACT FROM AUTHOR]

Potential losses and damages caused by natural hazards in the future are essential information that the public and stakeholders need to understand. Banyuwangi Regency, located at the eastern most tip of Java Island, borders the Indian Sea on the south and the Bali Strait on the east. These areas are hazardous because they are at increased risks of severe weather with frequent occurrences of volcanic eruptions and tsunamis. The hazards and possibilities of the future can be detected through a geomorphological map. This map provides several details about the regional characteristics of Banyuwangi and information on the geomorphological configuration related to natural hazards and disaster-prone areas. Such information can be of use to the people, the government and stakeholders alike. Following the geomorphological approach in this study, we classified landforms using four aspects, such as (1) morphology; (2) morphogenesis; (3) morpho-arrangement and (4) morpho-chronology. The data sources used are geological maps, DEM Alos Palsar and Google Satellite imagery for interpretative analysis. In this study area, the landform mapping identified 15 different landforms. There are eight landforms with landslide hazards and three with tsunami hazards. The landform with a landslide hazard has a common morphological condition which is hilly morphology. The landform with tsunami hazards as the main triggering factor has a plain morphology and an elevation below 50 m above sea level. Those conditions allow the tsunami surge to run up to reach further areas until it reaches an undulating or hilly morphology. Contribution: The results of this research are expected to inform the multi-hazards sources based on the geomorphological conditions in the Banyuwangi Regency. With such information, the government and the people can increase their ability to cope with disaster strikes in the future. [ABSTRACT FROM AUTHOR]

Abstract Disaster Risk Management (DRM) is complex due to interacting climate risks from interacting hazards and sectors. We develop a synthetic multi‐risk test case to explore the effects of these interactions on decision‐making under deep uncertainty. The test case accounts for changes in hazard impacts and occurrence frequency due to interactions between floods and droughts. Interactions between the shipping, housing and agricultural sectors are considered as well. We use this test case to explore the utility of the Dynamic Adaptive Policy Pathways for Multi‐Risk (DAPP‐MR) framework. DAPP‐MR has been introduced to assess DRM policies' effectiveness under deep uncertainties and to develop integrated adaptive strategies considering interactions across hazards, sectors and time. With the test case, we show that the stage‐wise approach of DAPP‐MR, which gradually increases the complexity of the analysis, can facilitate the evaluation process. Earlier stages of the analysis can be used to establish the direct cause‐effect relations, later stages allow us to identify whether additional interacting factors have a significant effect on the direct cause‐effect relations. As a result, decision‐makers can gain insights into dependencies and their relevance for developing short‐to long‐term strategies under deep uncertainty. We show that multi‐risk interactions can lead to non‐linear effects that influence the outcome of the policy analysis, for example, the indirect influence of a decision in one sector on another. Future work could investigate further improving the operationalization of this staged approach as well as extending the set of uncertainties, dynamics and decision‐rules accounted for in the multi‐risk test case.

Compound flooding (CF) events, driven by coincident/concurrent and mutually reinforcing factors such as heavy rainfall, storm surges, and river discharge, pose severe threats to coastal communities around the Globe. Moreover, the exacerbating influence of climate change and sea-level rise further amplifies these risks. This study delves into the complex and multifaceted issue of compound coastal flooding in two freshwater-influenced systems on the Gulf Coast of the United States – Southeast Texas and South Alabama. We first conduct a robust statistical analysis to evaluate the significance of non-stationarity, multi-dimensionality, and non-linearity of interactions among various drivers of CF. Second, to assess the extent to which current flood resilience policies and guidelines account for these characteristics of CF events, we perform a critical review of existing policy documents. The results of the statistical analysis reveal significant compounding and shifts in the statistics of flood drivers that emphasize the pressing need for a multi-mechanism, non-stationary approach to flood hazard assessment. We also found an evident lack of appropriate language/recommendation in policy documents of solid tools that systematically take non-stationarity, multi-dimensionality, and non-linearity of CF into account. By identifying the gaps between current policy measures and the detected complexities of CF, we seek to provide insights that can inform more effective flood resilience policies and design guidelines. Through this robust analysis, we aspire to bridge the divide between research and policy.

A hazard is a natural occurrence that might harm humans, animals or the environment. It may cause loss of life, illness or other health consequences, property damage, social and economic crisis or environmental degradation. Many places of the world are at risk from one or more disasters. Although many studies have concentrated on single hazards, there is a need for integrated evaluations of multi-hazards for more effective land management. A selection of datasets and methods, such as meteorological data, satellite images, and GIS, were used to create the risk assessment maps. The parameters for multi-hazard assessment are mainly considered as rainfall, slope, elevation, and land use/land cover and create a map in a GIS environment. For a particular region, multi-hazards can be produced by integrating maps of several hazard assessments. The objective of this study is an integration of geospatial and fuzzy-logic techniques for multi-hazard mapping. Extensive parts of Gujarat state (India) experience a wide range of natural hazards: floods, soil erosion, drought, and earthquakes. This research creates and evaluates individual and group multi-hazard maps to visualize the spatial variation of hazards in Gujarat state, India. The calculated four individual hazard maps have been categorised into five classes: very-low, low, moderate, high, and very high. The multi hazard map has been classified into sixteen classes using the GIS unsupervised. This study aims to improve disaster preparedness, enhance land management, or guide decision-making for disaster risk reduction. This study can be helpful in the future to engineers, planners, and local governments in the field of spatial planning and natural disaster management.

Floods and landslides cause continuous damage to ecosystems, infrastructures, and populations. Particularly, the occurrence and the existence of different natural hazards in the same territory highlight the need to improve risk mitigation strategies for local authorities and community resilience solutions for inhabitants. Analyzing and mapping social vulnerability provides information about the main features of a specific community to deal with natural events. Specifically, the interaction between multi-hazards and the socio-economic environment suggests multidisciplinary assessments that merge the physical and the socio-economic features of the affected territories, providing a useful approach to support multi-risk reduction planning. In this context, the article focuses on integrating landslide and flood hazard scenarios with social vulnerability in the Basilicata Region (southern Italy) at the census tract level. Thirteen municipalities were chosen as multi-hazard hot spots, while open-source platforms were selected for hazard and social vulnerability data collection and analyses. A geographic information system (GIS)-based approach was applied to combine different hazard scenarios with social vulnerability distribution among 1331 census tracts to detect the most vulnerable sub-municipality areas that need special attention in multi-risk reduction strategies. The results are presented in the form of maps, which provide a relevant suitable tool in local emergency planning.

Human-induced climate change has profound effects on extreme events, particularly those linked to global warming, such as heatwaves, droughts, and wildfires. These events disrupt ecosystems, emphasizing the imperative to understand the interactions among them to gauge the risks faced by vulnerable communities. Vulnerability levels vary primarily based on a community’s resources. Rural areas, especially in the Mediterranean region of Europe, are experiencing acute depopulation, creating a complex situation affecting various aspects of society, from economic declines to cultural heritage loss. Population decline in rural regions weakens resources, leading to the abandonment of built environments, fostering desertification, and elevating the risk of wildfires. Communities undergoing this deterioration process become exceptionally vulnerable, especially when dealing with and recovering from extreme natural phenomena. This review offers insights into the dynamics of these hazards and the predominant challenges in rural areas. By focusing on a topic that has received limited attention, the aim is to inform future research initiatives, ultimately improving risk assessment and mitigation strategies for these vulnerable communities.

This work aims to describe, classify, and analyze the occurrence of selected natural multi-hazards, specifically pluvial floods and sinkholes, affecting a district in the urban area of Rome, Italy. The procedure is based on a robust geological, geomorphological, and hydrogeological analysis performed using data collected and archived for the scope. The susceptibility is calculated based on geo-hydrological and geomorphological factors, as well as the occurrence of flooding and sinkholes. The areas prone to each single hazard were combined and put into the context of multi-hazard assessment by overlaying the susceptibility with buildings and population data. The resulting map shows that 50% of buildings (6215 inhabitants) are in an area of multi-hazard susceptibility; among these, 25% are in the highest multi-hazard classes (4 and 5). These areas are named “multi-hazard hotspots” because they are affected by many hazards with associated higher impacts. This study demonstrates that a comprehensive approach that combines the examination of geology, hydrogeology, modifications to historical morphology, and the occurrence of geological disasters is effective for mapping geohazards in urban areas and identifying locations with multiple hazards. A multi-hazard hotspot map can be used as a tool for planning actions aimed at reducing the vulnerability and exposure level of the urban population.

This study aims to assess the global reliability of coupled transmission tower-insulator-line systems considering soil-structure interaction (CTTILSs-SSI) subjected to multi-hazard of wind and ice. Firstly, two simplified models of CTTILSs-SSI under stochastic wind and ice loads are established, and their governing equations are derived through the Lagrange equation. On this basis, a global reliability assessment framework of CTTILSs-SSI is proposed based on the improved maximum entropy method, in which the global performance function of CTTILSs-SSI is defined via the state variable description method. Finally, a practical ultra-high voltage overhead transmission line located on the icing zone is chosen to illustrate the proposed framework. Moreover, to investigate the influence of soil-structure interaction (SSI) and soil types on the global reliability of transmission tower-insulator-line systems (TTILSs), the global reliability of CTTILSs-SSI with various soil types is compared with that of a fixed base system. The results indicate that under the in-plane wind and ice loads, the global failure probability of TTILSs is almost zero, and it is essentially not affected by the SSI effect and soil types. However, under the out-of-plane wind and ice loads, the global failure probability of CTTILSs-SSI is higher than that of the fixed base system, and the global failure probability of CTTILSs-SSI increases as the soil stiffness decreases. Accordingly, it may be more reasonable to consider the SSI effect into the global reliability analysis of TTILSs subjected to ice and out-of-plane wind loads, particularly when the soil is soft. • The in-plane and out-of-plane simplified models of CTTILSs-SSI under stochastic wind and ice loads are derived. • A global reliability analysis framework for CTTILSs-SSI is proposed based on the improved maximum entropy method. • The randomness of the wind load, ice load, and soil parameters is considered into the proposed global reliability analysis framework for CTTILSs-SSI. • The effects of SSI and soil types on the global reliability of transmission tower-insulator-line systems are explored. [ABSTRACT FROM AUTHOR]

Considering the potential severity of losses caused by post-earthquake fires compared to earthquakes alone, this study employed a three-dimensional Finite Element (FE) model established in ABAQUS to investigate the response of partially encased composite (PEC) steel and concrete columns under post-earthquake fire, serving as preliminary analysis for subsequent experimental studies. The validity of the FE model was verified using results from existing seismic and fire loading tests. In simulating the hysteresis behavior of PEC columns, this study evaluated the impacts of concrete discrete cracking and mechanical models on the simulation outcomes, thereby refining the modeling technique. A typical PEC column was selected as the focus of this investigation. Sequential earthquake-fire simulations were conducted using a data transfer technique to assess the fire resistance performance of different seismic damaged columns with different axial compression load ratios. The results indicate that the behavior of damaged PEC columns evolves based on initial damage, and the failure exhibits overall bending accompanied by local buckling of the steel flange. As the axial load ratio increases, the fire resistance time of seismic-damaged PEC columns significantly decreases. When the axial compression ratio is increased from 0.2 to 0.5, the fire resistance time of columns with damage factor D within 0.6 decreases by 59.07% on average. This sensitivity to axial pressure is particularly pronounced when earthquake damage is severe. Moreover, it finds that the lateral drift ratio under seismic action should be controlled within 2% to ensure that the post-earthquake fire resistance will not be significantly reduced. • The modeling technique is calibrated by physical tests of cyclic loads and fire loads. • Macro discrete cracks and a modified confined concrete model are introduced into the PEC model. • Three-dimensional high-fidelity numerical models of PEC columns under post-earthquake fire are established. • The effects of axial compression ratio and seismic damage on post-earthquake fire performance are analyzed. • The fire resistance of PEC columns with severe seismic damage is more sensitive to axial pressure. [ABSTRACT FROM AUTHOR]

• A multi-hazard approach is developed to coherently compare the structural performance under wind and earthquake. • A true multi-hazard method for preliminary probabilistic structural design is presented for mid-rise buildings. • The method leads to a uniform risks design solution for the structure under the considered design hazards. Focusing on natural hazards as wind and earthquake, the goal of this work is to understand if interference occurs in the design choices for steel buildings of a certain height, thus determining which design requirement and hazard is predominant, between Ultimate Limit State (ULS) requirements under earthquakes, or comfort of the occupants and the Serviceability Limit State (SLS) of the structure under wind. Thus, in order to compare structural responses, both in linear (i.e., SLSs) and non-linear field (i.e., ULS) a simplified analysis procedure that could be also implemented in Standards and in design practice (so-called SAC-FEMA method, originally introduced in the seismic field by Cornell in the early 2000s and more recently extended to the wind) is adapted, leading to a true optimal Performance-Based Multi-Hazard Design (PB-MH-D) of the structure considering the two hazards. The procedure is applied to two case-study steel buildings, 17 and 60 floor heigh; the approach is shown to efficiently lead to a design solution who consistently tackles with the same level of reliability with the two hazards. [ABSTRACT FROM AUTHOR]