F. Banfi, E. Bevacqua, P. Rivoire, Sérgio C. Oliveira, Joaquim G. Pinto, A. M. Ramos, C. De michele
{"title":"Temporal clustering of precipitation for detection of potential landslides","authors":"F. Banfi, E. Bevacqua, P. Rivoire, Sérgio C. Oliveira, Joaquim G. Pinto, A. M. Ramos, C. De michele","doi":"10.5194/nhess-24-2689-2024","DOIUrl":"https://doi.org/10.5194/nhess-24-2689-2024","url":null,"abstract":"Abstract. Landslides are complex phenomena that cause important impacts in vulnerable areas, including the destruction of infrastructure, environmental damage, and loss of life. The occurrence of landslide events is often triggered by rainfall episodes, single and intense ones or multiple ones occurring in sequence, i.e., clustered in time. Landslide prediction is typically obtained via process-based or empirical thresholds. Here, we develop a new approach that uses information on the temporal clustering of rainfall to detect landslide events and compare it with the use of classical empirical rainfall thresholds. In addition, we evaluate the performance of the two approaches combined together as a case study in the region of Lisbon in Portugal. We consider a dataset that categorizes landslides into shallow and deep events and a review of empirical rainfall thresholds that makes a good benchmark for testing our novel method. We show that the new approach based on temporal clustering overall has a good power of detecting landslide events but has a skill comparable with the classic rainfall threshold method. While there is no clear outperformance of one method, the novel clustering-based method has a higher sensitivity despite a lower precision than the threshold-based method. For all approaches, the potential detection is better for deep landslides than for shallow ones. The results of this study could help to improve the prediction of rainfall-triggered landslides.\u0000","PeriodicalId":18922,"journal":{"name":"Natural Hazards and Earth System Sciences","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141923502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hugo Rosero‐Velásquez, Mauricio Monsalve, Juan Camilo Gomez- Zapata, Elisa Ferrario, A. Poulos, J. C. de la Llera, Daniel Straub
{"title":"Risk-informed representative earthquake scenarios for Valparaíso and Viña del Mar, Chile","authors":"Hugo Rosero‐Velásquez, Mauricio Monsalve, Juan Camilo Gomez- Zapata, Elisa Ferrario, A. Poulos, J. C. de la Llera, Daniel Straub","doi":"10.5194/nhess-24-2667-2024","DOIUrl":"https://doi.org/10.5194/nhess-24-2667-2024","url":null,"abstract":"Abstract. Different risk management activities, such as land-use planning, preparedness, and emergency response, utilize scenarios of earthquake events. A systematic selection of such scenarios should aim at finding those that are representative of a certain severity, which can be measured by consequences to the exposed assets. For this reason, defining a representative scenario as the most likely one leading to a loss with a specific return period, e.g., the 100-year loss, has been proposed. We adopt this definition and develop enhanced algorithms for determining such scenarios for multiple return periods. With this approach, we identify representative earthquake scenarios for the return periods of 50, 100, 500, and 1000 years in the Chilean communes of Valparaíso and Viña del Mar, based on a synthetic earthquake catalog of 20 000 scenarios on the subduction zone with a magnitude of Mw≥5.0. We separately consider the residential-building stock and the electrical-power network and identify and compare earthquake scenarios that are representative of these systems. Because the representative earthquake scenarios are defined in terms of the annual loss exceedance rates, they vary in function of the exposed system. The identified representative scenarios for the building stock have epicenters located not further than 30 km from the two communes, with magnitudes ranging between 6.0 and 7.0. The epicenter locations of the earthquake scenarios representative of the electrical-power network are more spread out but not further than 100 km away from the two communes, with magnitudes ranging between 7.0 and 9.0. For risk management activities, we recommend considering the identified scenarios together with historical events.\u0000","PeriodicalId":18922,"journal":{"name":"Natural Hazards and Earth System Sciences","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141929495","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. Svennevig, Julian Koch, M. Keiding, G. Luetzenburg
{"title":"Assessing the impact of climate change on landslides near Vejle, Denmark, using public data","authors":"K. Svennevig, Julian Koch, M. Keiding, G. Luetzenburg","doi":"10.5194/nhess-24-1897-2024","DOIUrl":"https://doi.org/10.5194/nhess-24-1897-2024","url":null,"abstract":"Abstract. The possibility of increased landslide activity as a result of climate change has often been suggested, but few studies quantify this connection. Here, we present and utilize a workflow for the first time solely using publicly available data to assess the impact of future changes in landslide dynamic conditioning factors on landslide movement. In our case we apply the workflow to three slow-moving coastal landslides near Vejle, presenting the first study of its kind on Danish landslides. We examine modelled water table depth (WTD) as a dynamic conditioning factor using the DK-HIP model (Danish Hydrological Information and Prognosis system) that simulates historic and future WTD. The data show a clear correlation with landslide movement as recorded by the interferometric synthetic aperture radar (InSAR) time series for the period from 2015 to 2019. Movement of up to 84 mm yr−1 occurs during wet winter months when normalized WTD exceeds +0.5 m. During dry winters, no, or very little, seasonal landslide movement is observed. The DK-HIP model predicts an increase of up to 0.7 m in WTD at the study area by 2100 CE under the RCP8.5 (Representative Concentration Pathway) scenario (95 % confidence), which exceeds the levels this area has experienced in recent decades (mean increase of 0.2 m with a standard deviation of 0.25 m). This is likely to result in increased landslide activity and acceleration of movement. In a previous episode of increased landslide activity linked to extreme precipitation in the early 1980s, one of the examined landslides accelerated, causing damage to infrastructure and buildings. Our study clearly shows that these landslides are sensitive to climate change and highlights the potential of utilizing high-quality, publicly available data to address these complex scientific questions. The quality and quantity of such data are ever increasing, and so is the potential of this kind of approach.\u0000","PeriodicalId":18922,"journal":{"name":"Natural Hazards and Earth System Sciences","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141272685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Werthmann, M. Sapena, Marlene Kühnl, John Singer, Carolina Garcia, Tamara Breuninger, Moritz Gamperl, Bettina Menschik, Heike Schäfer, Sebastian Schröck, Lisa Y. Seiler, K. Thuro, Hannes Taubenböck
{"title":"Insights into the development of a landslide early warning system prototype in an informal settlement: the case of Bello Oriente in Medellín, Colombia","authors":"C. Werthmann, M. Sapena, Marlene Kühnl, John Singer, Carolina Garcia, Tamara Breuninger, Moritz Gamperl, Bettina Menschik, Heike Schäfer, Sebastian Schröck, Lisa Y. Seiler, K. Thuro, Hannes Taubenböck","doi":"10.5194/nhess-24-1843-2024","DOIUrl":"https://doi.org/10.5194/nhess-24-1843-2024","url":null,"abstract":"Abstract. The global number of vulnerable citizens in areas of landslide risk is expected to increase due to the twin forces of climate change and growing urbanization. Self-constructed or informal settlements are frequently built in hazardous terrain such as on landslide-prone slopes. They are characterized by high dynamics of growth, simple construction methods and strong social dynamics and are exposed to unsteady political approaches. Landslide early warning systems (LEWSs) can contribute to decreasing their vulnerability, but precise, affordable and culturally integrated LEWSs need to be further developed. In this paper, we present a 4-year living-lab research project called Inform@Risk that aimed to develop a LEWS prototype in the neighborhood of Bello Oriente, located on the urban–rural border of Medellín, Colombia. Its research team is composed of landscape architects, geo-engineers, and remote sensing and geo-informatics experts. The research team collaborated with a multitude of stakeholders: civil society, private enterprises, non-governmental agencies and various branches of government. A preliminary LEWS with the last functionalities still to be developed has been designed, implemented and handed over to the government. It has entered a test and calibration phase (i.e., warning-threshold development, procedures for warning and alert dissemination through the sensor system), which is on hold due to legal constraints. Our first findings indicate that the integrative development of technical aspects of a LEWS in informal settlements can be challenging, albeit manageable, whereas the level of social and political support is beyond the control of the designer. Steady political will is needed to increase technical capacities and funding of the operation and maintenance of an increased amount of monitoring equipment. Social outreach has to be continuous in order to inform, train, maintain the trust and increase the self-help capacities of the often rapidly changing population of an informal settlement. Legal requirements for a transfer of academic research projects to municipal authorities have to be clear from the start. Satisfying replacement housing options for the case of evacuation have to be in place in order to not lose the overall acceptance of the LEWS. As political will and municipal budgets can vary, a resilient LEWS for informal settlements has to achieve sufficient social and technical redundancy to maintain basic functionality even in a reduced-governmental-support scenario.\u0000","PeriodicalId":18922,"journal":{"name":"Natural Hazards and Earth System Sciences","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141101113","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Särkkä, Jani Räihä, Mika Rantanen, Matti Kämäräinen
{"title":"Simulating sea level extremes from synthetic low-pressure systems","authors":"J. Särkkä, Jani Räihä, Mika Rantanen, Matti Kämäräinen","doi":"10.5194/nhess-24-1835-2024","DOIUrl":"https://doi.org/10.5194/nhess-24-1835-2024","url":null,"abstract":"Abstract. In this article we present a method for numerical simulations of extreme sea levels using synthetic low-pressure systems as atmospheric forcing. Our simulations can be considered to be estimates of the high sea levels that may be reached when a low-pressure system of high intensity and optimal track passes the studied region. We test the method using sites located along the Baltic Sea coast and simulate synthetic cyclones with various tracks. To model the effects of the cyclone properties on sea level, we simulate internal Baltic Sea water level variations with a numerical two-dimensional hydrodynamic model, forced by an ensemble of time-dependent wind and air-pressure fields from synthetic cyclones. The storm surges caused by the synthetic cyclones come on top of the mean water level of the Baltic Sea, for which we used a fixed upper estimate of 100 cm. We find high extremes in the northern Bothnian Bay and in the eastern Gulf of Finland, where the sea level extreme due to the synthetic cyclone reaches up to 3.5 m. In the event that the mean water level of the Baltic Sea has a maximal value (1 m) during the cyclone, the highest sea levels of 4.5 m could thus be reached. We find our method to be suitable for use in further studies of sea level extremes.\u0000","PeriodicalId":18922,"journal":{"name":"Natural Hazards and Earth System Sciences","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141107461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Weatherill, S. Kotha, L. Danciu, Susana Vilanova, Fabrice Cotton
{"title":"Modelling seismic ground motion and its uncertainty in different tectonic contexts: challenges and application to the 2020 European Seismic Hazard Model (ESHM20)","authors":"G. Weatherill, S. Kotha, L. Danciu, Susana Vilanova, Fabrice Cotton","doi":"10.5194/nhess-24-1795-2024","DOIUrl":"https://doi.org/10.5194/nhess-24-1795-2024","url":null,"abstract":"Abstract. Current practice in strong ground motion modelling for probabilistic seismic hazard analysis (PSHA) requires the identification and calibration of empirical models appropriate to the tectonic regimes within the region of application, along with quantification of both their aleatory and epistemic uncertainties. For the development of the 2020 European Seismic Hazard Model (ESHM20) a novel approach for ground motion characterisation was adopted based on the concept of a regionalised scaled-backbone model, wherein a single appropriate ground motion model (GMM) is identified for use in PSHA, to which adjustments or scaling factors are then applied to account for epistemic uncertainty in the underlying seismological properties of the region of interest. While the theory and development of the regionalised scaled-backbone GMM concept have been discussed in earlier publications, implementation in the final ESHM20 required further refinements to the shallow-seismicity GMM in three regions, which were undertaken considering new data and insights gained from the feedback provided by experts in several regions of Europe: France, Portugal and Iceland. Exploration of the geophysical characteristics of these regions and analysis of additional ground motion records prompted recalibrations of the GMM logic tree and/or modifications to the proposed regionalisation. These modifications illustrate how the ESHM20 GMM logic tree can still be refined and adapted to different regions based on new ground motion data and/or expert judgement, without diverging from the proposed regionalised scaled-backbone GMM framework. In addition to the regions of crustal seismicity, the scaled-backbone approach needed to be adapted to earthquakes occurring in Europe's subduction zones and to the Vrancea deep seismogenic source region. Using a novel fuzzy methodology to classify earthquakes according to different seismic regimes within the subduction system, we compare ground motion records from non-crustal earthquakes to existing subduction GMMs and identify a suitable-backbone GMM for application to subduction and deep seismic sources in Europe. The observed ground motion records from moderate- and small-magnitude earthquakes allow us to calibrate the anelastic attenuation of the backbone GMM specifically for the eastern Mediterranean region. Epistemic uncertainty is then calibrated based on the global variability in source and attenuation characteristics of subduction GMMs. With the ESHM20 now completed, we reflect on the lessons learned from implementing this new approach in regional-scale PSHA and highlight where we hope to see new developments and improvements to the characterisation of ground motion in future generations of the European Seismic Hazard Model.\u0000","PeriodicalId":18922,"journal":{"name":"Natural Hazards and Earth System Sciences","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141107354","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Håvard Toft, John Sykes, Andrew R. Schauer, J. Hendrikx, Audun Hetland
{"title":"AutoATES v2.0: Automated Avalanche Terrain Exposure Scale mapping","authors":"Håvard Toft, John Sykes, Andrew R. Schauer, J. Hendrikx, Audun Hetland","doi":"10.5194/nhess-24-1779-2024","DOIUrl":"https://doi.org/10.5194/nhess-24-1779-2024","url":null,"abstract":"Abstract. Avalanche risk assessment is complex and challenging, with terrain assessment as one of the most fundamental factors. To aid people's terrain assessment, Parks Canada developed the Avalanche Terrain Exposure Scale (ATES), a system that classifies the severity of avalanche terrain into five classes from non-avalanche terrain to extreme terrain. Manual classification is laborious and dependent on expert's assessments. To ease the process Larsen et al. (2020) developed an automated ATES model (AutoATES v1.0). Although the model allowed large-scale mapping, it had some significant limitations. This paper presents an improved AutoATES v2.0 model improving the potential release area (PRA) model, utilizing the new Flow-Py runout simulation package. Furthermore, it incorporates forest density data in the PRA, in Flow-Py, and in a newly developed post-forest-classification step. AutoATES v2.0 has also been rewritten in open-source software, making it more widely available. The paper includes a validation of the model measured against two consensus maps made by three experts at two different locations in western Canada. For Bow Summit, the F1 score (a measure of how well the model performs) improved from 64 % to 77 %. For Connaught Creek, the F1 score improved from 40 % to 71 %. The main challenge limiting large-scale ATES classification is the determination of optimal input parameters for different regions and climates. In areas where AutoATES v2.0 is applied, it can be a valuable tool for avalanche risk assessment and decision-making. Ultimately, our goal is for AutoATES v2.0 to enable efficient, regional-scale, and potentially global ATES mapping in a standardized manner rather than based solely on expert judgment.\u0000","PeriodicalId":18922,"journal":{"name":"Natural Hazards and Earth System Sciences","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141118184","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wilson C. H. Chan, Nigel W. Arnell, G. Darch, Katie Facer-Childs, Theodore G. Shepherd, Maliko Tanguy
{"title":"Added value of seasonal hindcasts to create UK hydrological drought storylines","authors":"Wilson C. H. Chan, Nigel W. Arnell, G. Darch, Katie Facer-Childs, Theodore G. Shepherd, Maliko Tanguy","doi":"10.5194/nhess-24-1065-2024","DOIUrl":"https://doi.org/10.5194/nhess-24-1065-2024","url":null,"abstract":"Abstract. The UK has experienced recurring periods of hydrological droughts in the past, including the drought declared in summer 2022. Seasonal hindcasts, consisting of a large sample of plausible weather sequences, can be used to create drought storylines and add value to existing approaches to water resources planning. In this study, the drivers of winter rainfall in the Anglian region in England are investigated using the ECMWF SEAS5 hindcast dataset, which includes 2850 plausible winters across 25 ensemble members and 3 lead times. Four winter clusters are defined using the hindcast winters based on possible combinations of various atmospheric circulation indices (such as the North Atlantic Oscillation, NAO; East Atlantic, EA, pattern; and El Niño–Southern Oscillation). Using the 2022 drought as a case study, we demonstrate how storylines representing alternative ways the event could have unfolded can be used to explore plausible worst-case scenarios over winter 2022/23 and beyond. The winter clusters span a range of temperature and rainfall response in the study region and represent circulation storylines that could have happened over winter 2022/23. River flow and groundwater level simulations with the large sample of plausible hindcast winters show that drier-than-average winters characterised by predominantly NAO−/EA− and NAO+/EA− circulation patterns could have resulted in the continuation of the drought with a high likelihood of below-normal to low river flows across all selected catchments and boreholes by spring and summer 2023. Catchments in Norfolk were particularly vulnerable to a dry summer in 2023 as river flows were not estimated to recover to normal levels even with wet winters characterised predominantly by NAO−/EA+ and NAO+/EA+ circulation patterns, due to insufficient rainfall to overcome previous dry conditions and the slow response nature of groundwater-dominated catchments. Through this analysis, we aim to demonstrate the added value of this approach to create drought storylines during an ongoing event. Storylines constructed in this way supplement traditional weather forecasts and hydrological outlooks, in order to explore a wider range of plausible outcomes.\u0000","PeriodicalId":18922,"journal":{"name":"Natural Hazards and Earth System Sciences","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140368638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Comparison of debris flow observations, including fine-sediment grain size and composition and runout model results, at Illgraben, Swiss Alps","authors":"Daniel Bolliger, F. Schlunegger, B. McArdell","doi":"10.5194/nhess-24-1035-2024","DOIUrl":"https://doi.org/10.5194/nhess-24-1035-2024","url":null,"abstract":"Abstract. Debris flows are important processes for the assessment of natural hazards due to their damage potential. To assess the impact of a potential debris flow, parameters such as the flow velocity, flow depth, maximum discharge, and volume are of great importance. This study uses data from the Illgraben observation station in the central Alps of Switzerland to explore the relationships between these flow parameters and the debris flow dynamics. To this end, we simulated previous debris flow events with the RAMMS::Debrisflow (Rapid Mass Movement Simulation::Debrisflow) runout model, which is based on a numerical solution of the shallow water equations for granular flows using the Voellmy friction relation. Here, the events were modelled in an effort to explore possible controls on the friction parameters μ and ξ, which describe the Coulomb friction and the turbulent friction, respectively, in the model. Additionally, sediment samples from levee deposits were analysed for their grain size distributions (14 events) and their mineralogical properties (4 events) to explore if the properties of the fine-grained matrix have an influence on the debris flow dynamics. Finally, field data from various debris flows such as the flow velocities and depths were statistically compared with the grain size distributions, the mineralogical properties, and the simulation results to identify the key variables controlling the kinematics of these flows. The simulation results point to several ideal solutions, which depend on the Coulomb and turbulent friction parameters (μ and ξ, respectively). In addition, the modelling results show that the Coulomb and turbulent frictions of a flow are related to the Froude number if the flow velocity is < 6–7 m s−1. It is also shown that the fine-sediment grain size or clay-particle mineralogy of a flow neither correlates with the flow's velocity and depth, nor can it be used to quantify the friction in the Voellmy friction relation. This suggests that the frictional behaviour of a flow may be controlled by other properties such as the friction generated by the partially fluidised coarse granular sediment. Yet, the flow properties are well-correlated with the flow volume, from which most other parameters can be derived, which is consistent with common engineering practice.\u0000","PeriodicalId":18922,"journal":{"name":"Natural Hazards and Earth System Sciences","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140371329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The influence of aftershocks on seismic hazard analysis: a case study from Xichang and the surrounding areas","authors":"Qing Wu, Guijuan Lai, Jian Wu, Jinmeng Bi","doi":"10.5194/nhess-24-1017-2024","DOIUrl":"https://doi.org/10.5194/nhess-24-1017-2024","url":null,"abstract":"Abstract. In some instances, a strong aftershock can cause more damage than the mainshock. Ignoring the influence of aftershocks may lead to the underestimation of the seismic hazard of some areas. Taking Xichang and its surrounding areas as an example and based on the Seismic ground motion parameters zonation map of China (GB 18306-2015), this study used the Monte Carlo method to simulate synthetic mainshock sequences. Additionally, the Omi–Reasenberg–Jones (Omi–R–J) aftershock activity model is used to simulate the aftershock sequences that follow mainshocks above a certain magnitude threshold. Then, the mainshock and the aftershocks are combined to calculate the regional seismic hazard using ground motion prediction equations (GMPEs). Finally, the influence of aftershocks on seismic hazard analysis is examined and considered. The results show that in areas with moderate to strong seismic backgrounds, the influence of aftershocks on probabilistic seismic hazard analysis can exceed 50 %. These results suggest that the impact of aftershocks should be properly considered for future probabilistic seismic hazard analyses, especially in areas with moderate to strong seismic activity backgrounds and in areas prone to secondary disasters such as landslides and mudslides.\u0000","PeriodicalId":18922,"journal":{"name":"Natural Hazards and Earth System Sciences","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140372086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}