We present a discrete-element-based model which is adapted and used to produce hillslope debris flows. The model parameters were calibrated using field experiments, and a very good agreement was found in terms of pressure and flow velocity. Calibration results suggested that a link might exist between the model parameters and the initial conditions of the granular material. However, to better understand this link, further investigations are required by conducting detailed lab-scale experiments.
Tropical cyclone wind models are often used in engineering applications. However, these models lack the required accuracy when the size of the tropical cyclone is not known. In this paper, new relationships are derived to describe parameters affecting the size. These relationships are formulated using observed data and make it possible to estimate tropical cyclone size and to use this information in tropical cyclone wind models to obtain more reliable estimates of the tropical cyclone winds.
In the current study (N = 118), we found evidence for a buffering effect of community resilience (as a form of social support) on post-disaster mental health and life satisfaction. Our work shows that previous work might have underestimated the effect of social support on post-disaster adjustment. Applying (statistical) moderator analysis, the current work contributes to the discussion of the role of social factors for mental health outcomes of flooding.
The work carried out for this study is part of a collaborative research program studying the impact of ground hazards on transportation infrastructure in Canada. The focus of the paper is the testing and application of a new simulation technique which can model the movement of falling rock material. These initial tests show that our simulation technique is capable of reproducing material accumulations from rockfall events which occurred above a section of railway in British Columbia, Canada.
The coupled National Water Model (NWM)–Height Above Nearest Drainage flood mapping methodology provides the basis for operational flood forecasting across the continental United States. This paper evaluates how the method performs for 28 case studies using a historic archive of flood extents and a retrospective run of the NWM. We provide a summary of the results and discuss where the method is performing reliably, the general reasons for poor forecasts, and how the method might be improved.
Lahars are fast-moving mixtures of volcanic debris and water propagating downslope on volcanoes that can be very dangerous for people and property. Identification of lahar source areas and initiation mechanisms is crucial to comprehensive lahar hazard assessment. We present the first rain-triggered lahar susceptibility map for La Fossa volcano (Vulcano, Italy) combining probabilistic tephra modelling, slope-stability modelling, precipitation data, field characterizations, and geotechnical tests.
The first version of the Pan-European Indoor Radon Map is presented in this article. The map has been developed using summary statistics estimated from 1.2 million samples. It represents an average radon concentration per 10 km x 10 km grid cell under the assumption that there are dwellings in the grid cell. It is a major contribution to the understanding of the exposure to ionizing radiation of Europeans and a first step towards a European radon exposure and, in the future, radon dose map.
Communities need to be prepared to deal with increasing exposure to natural hazards. We compared and categorized hazard responses reported in over 300 community case studies. A global overview of local response actions can help local communities, policymakers and funding agencies to develop effective strategies to prepare for and manage natural disasters. We found that actions are typically hazard specific and most directed at individual and material well-being.
Identifying landslide hazards is challenging but important for understanding risks to people and both built and natural resources. We use models to identify landslide hazards based on observed landslides and local site traits such as slope and on physical mechanisms such as soil moisture. Integrating both approaches improves hazard detection by accounting for processes not captured in the physically based model. Hazard maps are made for the North Cascades National Park Complex (Washington, USA).
This work examines relationships between coastal hazard, exposure, and vulnerability to describe trajectories of risk at the county scale along the US Atlantic coast over the past 5 decades. Our findings suggest that modelling efforts to predict future coastal risk need to address feedbacks between hazard, exposure, and vulnerability to capture emergent patterns of risk in space and time.
We developed a novel approach in using Bayesian networks (BNs) for ensemble flood forecasting in a case study in Iran. This allows fast early warning without the need for hydrological modelling. We recommend to combine precipitation ensembles with hydrological initial conditions in the BN. The number of observed flood events is low by nature. Under the limited amount of data, BN outperformed artificial neural networks with good results. Future work will validate the concept further.
To limit the losses due to floods, people can adopt measures to protect their dwellings. We assessed the cost and efficacy of such measures using computer modelling. We found that the benefits of most of the measures studied are unlikely to exceed their cost when they are taken in dwellings that are not exposed to frequent floods (probability of occurrence of less than 1 / 100 per year). It is also often less expensive to use building materials adapted to floods than other common materials.
On many beaches, lifeguards set out flags to warn beach users of the surf and rip hazard based on the regional surf forecast and careful observation. There is a potential that the chosen flag does not accurately reflect the potential risk. Results of a machine learning analysis suggest that the greatest number of rescues occurred on days when the lifeguard flew a more cautious flag than the model predicted. It is argued that that beach users may be discounting lifeguard warnings.
The paper presents AGRIDE-c: a conceptual model for the estimation of flood damage to crops. The model estimates both the physical damage on the plants and its economic consequences on the income of the farmers. This allows AGRIDE-c to support effective damage mitigation strategies, at both public and individual farmer levels. The model can be adapted to different geographical and economic contexts, as exemplified by its implementation for the context of northern Italy.
An early-warning system (EWS) for flood prediction was developed in the upper reach of the Miño River and the city of Lugo (NW Spain). This EWS can provide accurate results in less than 1 h, for a forecast horizon of 3 d, and report an alert situation to decision makers in order to mitigate the consequences of floods. In addition, this EWS can be easily adapted for any area of the world since the required input data and software are freely available.
On 9 October 2018, an extreme convective storm (> 300 mm accumulated in 6 h) generated a flash flood (305 m3 s−1) in the Ses Planes torrent that devastated the town of Sant Llorenç (Mallorca, Spain). Water reached a depth of 3 m in the most affected areas, and there was greatly increased flow velocity at bridges crossing the town. The floodwaters were very powerful and modified the channel morphology: more than 5000 t of sediment was deposited in the 2 km reach upstream of the town.
We demonstrate a method of tsunami risk assessment for two buildings using copulas of tsunami hazards that can consider the nonlinear spatial correlation of wave heights. As a result, the maximum value of the expected aggregate damage probability was approximately 3.0 % higher in the case considering the wave height correlation. We clearly showed the importance of considering wave height correlation and the usefulness of copula modeling in evaluating the tsunami risk of a building portfolio.
Carlos D. Hoyos, Lina I. Ceballos, Jhayron S. Pérez-Carrasquilla, Julián Sepúlveda, Silvana M. López-Zapata, Manuel D. Zuluaga, Nicolás Velásquez, Laura Herrera-Mejía, Olver Hernández, Gisel Guzmán-Echavarría, and Mauricio Zapata
On the morning of 18 May 2015, a flash flood in the La Liboriana river basin inundated the town of Salgar, killing more than 100 people. The ultimate goal of science, regarding risk management, is to be able to reduce the number of people affected by severe storms. Our goal is to identify the meteorological conditions that led to the flood, assess the characteristics of the rainfall events before the disaster, and identify lessons for vulnerable regions settled in complex terrains.