The maximum possible earthquake magnitude is Mw 8.15 with an average slip of 8.25 m in the southernmost portion of the Ryukyu Trench. One hundred slip distributions of the seismic rupture surface were generated by a stochastic slip model. The simulated results demonstrate that the complexity of the rupture plane has a significant influence on the near field for local tsunamis. The propagation of tsunami waves and the peak wave heights largely vary in response to the slip distribution.
Natural hazard events affecting the Swiss transportation networks during the 5-year time period 2012–2016 were collected in a database with a significant effort for small events (< 10 m−3) that are generally not radar screened. Of 848 collected events, 95 % are small events for which annual direct cost was estimated at EUR 2.5 million. Analysis of the 172 attributes by event allows us to highlight their spatial, temporal, and damage trends as well as their impacts on road and railway traffic.
One of the main volcanic processes affecting road bridges are lahars, which are flows of water and volcanic material running down the slopes of a volcano. In this paper, bridge failure models due to lahars are proposed and, based on these, fragility curves are developed. Fragility curves are parameterized by maximum likelihood estimation, assuming a cumulative log-normal distribution. Bridge failure models are empirically evaluated using data of 15 bridges that were affected by lahars.
We examine sources of epistemic uncertainty in coastal flood risk models. We find that uncertainty from sea level estimations can be higher than that related to greenhouse gas emissions or climate prediction errors. Of comparable importance is information on coastal protection levels and the topography. In the absence of large datasets with sufficient resolution and accuracy, the last two factors are the main bottlenecks in terms of estimating coastal flood risks at large scales.
The present research applies a methodology to estimate tsunami damage in a city in northern Chile which was recently affected by a tsunami and is now under reconstruction. The results are in good agreement with other results from plains in Japan, where low damage was observed at relatively high inundation depths. In addition, the damage assessment showed a significant impact in the city in the case of a new tsunami event if the city is rebuilt with the same type of structures.
Landslides are a hazard in terrestrial environments with slopes. This paper presents global analysis on patterns of fatal landsliding between 2004 and 2016, using a database collated from media reporting. The data show ~ 56 000 people were killed in 4862 landslide events. Active landslide years coincide with patterns of regional rainfall: most landslides were rainfall triggered. For the first time, analysis shows the number of landslides triggered by human activity increased with time.
Regional-scale landslide forecasting traditionally strongly relies on empirical approaches and landslide-triggering rainfall thresholds. Today, probabilistic methods utilizing ensemble predictions are frequently used for flood forecasting. In our study, we specify how such an approach could also be applied for landslide forecasts and for operational landslide forecasting and early warning systems. To this end, we implemented a physically based landslide model in a probabilistic framework.
We study the sedimentary record of past tsunamis along the coastal area west of Alexandria (northwestern Egypt), taking into account the occurrence of major historical earthquakes in the eastern Mediterranean. Dated charcoal and shell in sedimentary units allow the correlation with the 1870 (Mw 7.5), 1303 (Mw ~8) and 365 (Mw ~8) large tsunamigenic earthquakes. Our results point out the size and recurrence of past tsunamis and related hazards on the Egyptian coastline and eastern Mediterranean.
The objective of this research is to improve an index originally developed to assess physical consequences of a considered hazard, by including socio-economic characteristics of population information. Data from the French census and a survey on risk perception (questionnaires) were used to propose an index taking into account the three main phases of risk management: preparedness, crisis management and recovery.
Tsunamis are natural phenomena that may cause great destruction when they reach coastal areas. This study focuses on establishing a connection between technical and scientific tsunami risk assessment and disaster risk reduction. The ultimate goal is to reduce the consequences that a tsunami may have in tsunami prone communities, focusing on prevention and preparedness strategies, through the generation and application of useful tsunami-risk management tools. The work has focused on Oman.
The number of occurrences of ground subsidence induced by a leakage of aged pipelines for water and sewage in urban areas resulting in various sizes of cavity near the urban railway in South Korea has increased and it may cause roadbed settlement to exceed the allowable value. In this study, a three-dimensional numerical analysis is carried out to estimate roadbed stability and its risk level associated with various groundwater levels and sizes of cavities in simulated ground conditions.
This paper introduces a methodology to support network managers in the quantification of the risk related to their networks. The method emphasizes the integration of the spatial and temporal attributes of the events that need to be modeled to estimate the risk. This work then demonstrates the usefulness of the methodology through its application to design and implement a risk assessment to estimate the potential impact of flood and mudflow events on a road network located in Switzerland.
Rockfalls present a hazard to railways in mountainous terrain. 3-D remote monitoring data can be used to identify events that occurred between data collections. Using a case study from British Columbia, we present a method combining 3-D rockfall event data with spatial rockfall simulations to provide a refined estimate of the frequency of rockfalls presenting a direct hazard to passing trains and railway infrastructure, which is often less than the total number of rockfalls that occurred.