Research article
09 Jun 2022
Research article
| 09 Jun 2022
On the correlation between a sub-level qualifier refining the danger level with observations and models relating to the contributing factors of avalanche danger
Frank Techel et al.
Related authors
Stephanie Mayer, Alec van Herwijnen, Frank Techel, and Jürg Schweizer
The Cryosphere, 16, 4593–4615, https://doi.org/10.5194/tc-16-4593-2022, https://doi.org/10.5194/tc-16-4593-2022, 2022
Short summary
Short summary
Information on snow instability is crucial for avalanche forecasting. We introduce a novel machine-learning-based method to assess snow instability from snow stratigraphy simulated with the snow cover model SNOWPACK. To develop the model, we compared observed and simulated snow profiles. Our model provides a probability of instability for every layer of a simulated snow profile, which allows detection of the weakest layer and assessment of its degree of instability with one single index.
Cristina Pérez-Guillén, Frank Techel, Martin Hendrick, Michele Volpi, Alec van Herwijnen, Tasko Olevski, Guillaume Obozinski, Fernando Pérez-Cruz, and Jürg Schweizer
Nat. Hazards Earth Syst. Sci., 22, 2031–2056, https://doi.org/10.5194/nhess-22-2031-2022, https://doi.org/10.5194/nhess-22-2031-2022, 2022
Short summary
Short summary
A fully data-driven approach to predicting the danger level for dry-snow avalanche conditions in Switzerland was developed. Two classifiers were trained using a large database of meteorological data, snow cover simulations, and danger levels. The models performed well throughout the Swiss Alps, reaching a performance similar to the current experience-based avalanche forecasts. This approach shows the potential to be a valuable supplementary decision support tool for assessing avalanche hazard.
Veronika Hutter, Frank Techel, and Ross S. Purves
Nat. Hazards Earth Syst. Sci., 21, 3879–3897, https://doi.org/10.5194/nhess-21-3879-2021, https://doi.org/10.5194/nhess-21-3879-2021, 2021
Short summary
Short summary
How is avalanche danger described in public avalanche forecasts? We analyzed 6000 textual descriptions of avalanche danger in Switzerland, taking the perspective of the forecaster. Avalanche danger was described rather consistently, although the results highlight the difficulty of communicating conditions that are neither rare nor frequent, neither small nor large. The study may help to refine the ways in which avalanche danger could be communicated to the public.
Jürg Schweizer, Christoph Mitterer, Benjamin Reuter, and Frank Techel
The Cryosphere, 15, 3293–3315, https://doi.org/10.5194/tc-15-3293-2021, https://doi.org/10.5194/tc-15-3293-2021, 2021
Short summary
Short summary
Snow avalanches threaten people and infrastructure in snow-covered mountain regions. To mitigate the effects of avalanches, warnings are issued by public forecasting services. Presently, the five danger levels are described in qualitative terms. We aim to characterize the avalanche danger levels based on expert field observations of snow instability. Our findings contribute to an evidence-based description of danger levels and to improve consistency and accuracy of avalanche forecasts.
Elisabeth D. Hafner, Frank Techel, Silvan Leinss, and Yves Bühler
The Cryosphere, 15, 983–1004, https://doi.org/10.5194/tc-15-983-2021, https://doi.org/10.5194/tc-15-983-2021, 2021
Short summary
Short summary
Satellites prove to be very valuable for documentation of large-scale avalanche periods. To test reliability and completeness, which has not been satisfactorily verified before, we attempt a full validation of avalanches mapped from two optical sensors and one radar sensor. Our results demonstrate the reliability of high-spatial-resolution optical data for avalanche mapping, the suitability of radar for mapping of larger avalanches and the unsuitability of medium-spatial-resolution optical data.
Frank Techel, Karsten Müller, and Jürg Schweizer
The Cryosphere, 14, 3503–3521, https://doi.org/10.5194/tc-14-3503-2020, https://doi.org/10.5194/tc-14-3503-2020, 2020
Short summary
Short summary
Exploring a large data set of snow stability tests and avalanche observations, we quantitatively describe the three key elements that characterize avalanche danger: snowpack stability, the frequency distribution of snowpack stability, and avalanche size. The findings will aid in refining the definitions of the avalanche danger scale and in fostering its consistent usage.
Frank Techel, Kurt Winkler, Matthias Walcher, Alec van Herwijnen, and Jürg Schweizer
Nat. Hazards Earth Syst. Sci., 20, 1941–1953, https://doi.org/10.5194/nhess-20-1941-2020, https://doi.org/10.5194/nhess-20-1941-2020, 2020
Short summary
Short summary
Snow instability tests, like the extended column test (ECT), provide valuable information regarding point snow instability. A large data set of ECT – together with information on slope instability – was explored. The findings clearly show that combining information regarding propagation propensity and fracture initiation provided the best correlation with slope instability. A new four-class stability interpretation scheme is proposed for ECT results.
Jürg Schweizer, Christoph Mitterer, Frank Techel, Andreas Stoffel, and Benjamin Reuter
The Cryosphere, 14, 737–750, https://doi.org/10.5194/tc-14-737-2020, https://doi.org/10.5194/tc-14-737-2020, 2020
Short summary
Short summary
Snow avalanches represent a major natural hazard in seasonally snow-covered mountain regions around the world. To avoid periods and locations of high hazard, avalanche warnings are issued by public authorities. In these bulletins, the hazard is characterized by a danger level. Since the danger levels are not well defined, we analyzed a large data set of avalanches to improve the description. Our findings show discrepancies in present usage of the danger scale and show ways to improve the scale.
Frank Techel, Christoph Mitterer, Elisabetta Ceaglio, Cécile Coléou, Samuel Morin, Francesca Rastelli, and Ross S. Purves
Nat. Hazards Earth Syst. Sci., 18, 2697–2716, https://doi.org/10.5194/nhess-18-2697-2018, https://doi.org/10.5194/nhess-18-2697-2018, 2018
Short summary
Short summary
In 1993, the European Avalanche Warning Services agreed upon a common danger scale to describe the regional avalanche hazard: the European Avalanche Danger Scale. Using published avalanche forecasts, we explored whether forecasters use the scale consistently. We noted differences in the use of the danger levels, some of which could be linked to the size of the regions a regional danger level is issued for. We recommend further harmonizing the avalanche forecast products in the Alps.
Alexandre Badoux, Norina Andres, Frank Techel, and Christoph Hegg
Nat. Hazards Earth Syst. Sci., 16, 2747–2768, https://doi.org/10.5194/nhess-16-2747-2016, https://doi.org/10.5194/nhess-16-2747-2016, 2016
Short summary
Short summary
A database of fatalities caused by natural hazards in Switzerland was compiled for the period from 1946 to 2015: in 70 years, 635 events occurred causing 1023 fatalities. The most common causes of death were snow avalanches (37 %), followed by lightning (16 %), floods (12 %), windstorms (10 %), rockfalls (8 %) and landslides (7 %). The annual number of victims showed a distinct decrease over time. In comparison to other countries, the natural hazard mortality rate in Switzerland is quite low.
Frank Techel, Frédéric Jarry, Georg Kronthaler, Susanna Mitterer, Patrick Nairz, Miha Pavšek, Mauro Valt, and Gian Darms
Geogr. Helv., 71, 147–159, https://doi.org/10.5194/gh-71-147-2016, https://doi.org/10.5194/gh-71-147-2016, 2016
Short summary
Short summary
During the last 45 years, about 100 people lost their lives in avalanches in the European Alps each year. Avalanche fatalities in settlements and on transportation corridors have considerably decreased since the 1970s. In contrast, the number of avalanche fatalities during recreational activities away from avalanche-secured terrain doubled between the 1960s and 1980s and has remained relatively stable since, despite a continuing strong increase in winter backcountry recreational activities.
F. Techel, B. Zweifel, and K. Winkler
Nat. Hazards Earth Syst. Sci., 15, 1985–1997, https://doi.org/10.5194/nhess-15-1985-2015, https://doi.org/10.5194/nhess-15-1985-2015, 2015
Short summary
Short summary
We present a spatiotemporal picture of winter backcountry usage in the Swiss Alps and compare this with the distribution of avalanche accidents.
Critical avalanche danger conditions and an unfavorable snowpack (old snow problem) strongly increase the risk of winter backcountry recreationists to be involved in a severe avalanche accident. This explains why there are comparably more accidents in the inneralpine regions with less activity.
F. Techel and C. Pielmeier
Nat. Hazards Earth Syst. Sci., 14, 779–787, https://doi.org/10.5194/nhess-14-779-2014, https://doi.org/10.5194/nhess-14-779-2014, 2014
Stephanie Mayer, Alec van Herwijnen, Frank Techel, and Jürg Schweizer
The Cryosphere, 16, 4593–4615, https://doi.org/10.5194/tc-16-4593-2022, https://doi.org/10.5194/tc-16-4593-2022, 2022
Short summary
Short summary
Information on snow instability is crucial for avalanche forecasting. We introduce a novel machine-learning-based method to assess snow instability from snow stratigraphy simulated with the snow cover model SNOWPACK. To develop the model, we compared observed and simulated snow profiles. Our model provides a probability of instability for every layer of a simulated snow profile, which allows detection of the weakest layer and assessment of its degree of instability with one single index.
Cristina Pérez-Guillén, Frank Techel, Martin Hendrick, Michele Volpi, Alec van Herwijnen, Tasko Olevski, Guillaume Obozinski, Fernando Pérez-Cruz, and Jürg Schweizer
Nat. Hazards Earth Syst. Sci., 22, 2031–2056, https://doi.org/10.5194/nhess-22-2031-2022, https://doi.org/10.5194/nhess-22-2031-2022, 2022
Short summary
Short summary
A fully data-driven approach to predicting the danger level for dry-snow avalanche conditions in Switzerland was developed. Two classifiers were trained using a large database of meteorological data, snow cover simulations, and danger levels. The models performed well throughout the Swiss Alps, reaching a performance similar to the current experience-based avalanche forecasts. This approach shows the potential to be a valuable supplementary decision support tool for assessing avalanche hazard.
Antoine Guillemot, Alec van Herwijnen, Eric Larose, Stephanie Mayer, and Laurent Baillet
The Cryosphere, 15, 5805–5817, https://doi.org/10.5194/tc-15-5805-2021, https://doi.org/10.5194/tc-15-5805-2021, 2021
Short summary
Short summary
Ambient noise correlation is a broadly used method in seismology to monitor tiny changes in subsurface properties. Some environmental forcings may influence this method, including snow. During one winter season, we studied this snow effect on seismic velocity of the medium, recorded by a pair of seismic sensors. We detected and modeled a measurable effect during early snowfalls: the fresh new snow layer modifies rigidity and density of the medium, thus decreasing the recorded seismic velocity.
Veronika Hutter, Frank Techel, and Ross S. Purves
Nat. Hazards Earth Syst. Sci., 21, 3879–3897, https://doi.org/10.5194/nhess-21-3879-2021, https://doi.org/10.5194/nhess-21-3879-2021, 2021
Short summary
Short summary
How is avalanche danger described in public avalanche forecasts? We analyzed 6000 textual descriptions of avalanche danger in Switzerland, taking the perspective of the forecaster. Avalanche danger was described rather consistently, although the results highlight the difficulty of communicating conditions that are neither rare nor frequent, neither small nor large. The study may help to refine the ways in which avalanche danger could be communicated to the public.
Jürg Schweizer, Christoph Mitterer, Benjamin Reuter, and Frank Techel
The Cryosphere, 15, 3293–3315, https://doi.org/10.5194/tc-15-3293-2021, https://doi.org/10.5194/tc-15-3293-2021, 2021
Short summary
Short summary
Snow avalanches threaten people and infrastructure in snow-covered mountain regions. To mitigate the effects of avalanches, warnings are issued by public forecasting services. Presently, the five danger levels are described in qualitative terms. We aim to characterize the avalanche danger levels based on expert field observations of snow instability. Our findings contribute to an evidence-based description of danger levels and to improve consistency and accuracy of avalanche forecasts.
Elisabeth D. Hafner, Frank Techel, Silvan Leinss, and Yves Bühler
The Cryosphere, 15, 983–1004, https://doi.org/10.5194/tc-15-983-2021, https://doi.org/10.5194/tc-15-983-2021, 2021
Short summary
Short summary
Satellites prove to be very valuable for documentation of large-scale avalanche periods. To test reliability and completeness, which has not been satisfactorily verified before, we attempt a full validation of avalanches mapped from two optical sensors and one radar sensor. Our results demonstrate the reliability of high-spatial-resolution optical data for avalanche mapping, the suitability of radar for mapping of larger avalanches and the unsuitability of medium-spatial-resolution optical data.
Frank Techel, Karsten Müller, and Jürg Schweizer
The Cryosphere, 14, 3503–3521, https://doi.org/10.5194/tc-14-3503-2020, https://doi.org/10.5194/tc-14-3503-2020, 2020
Short summary
Short summary
Exploring a large data set of snow stability tests and avalanche observations, we quantitatively describe the three key elements that characterize avalanche danger: snowpack stability, the frequency distribution of snowpack stability, and avalanche size. The findings will aid in refining the definitions of the avalanche danger scale and in fostering its consistent usage.
Frank Techel, Kurt Winkler, Matthias Walcher, Alec van Herwijnen, and Jürg Schweizer
Nat. Hazards Earth Syst. Sci., 20, 1941–1953, https://doi.org/10.5194/nhess-20-1941-2020, https://doi.org/10.5194/nhess-20-1941-2020, 2020
Short summary
Short summary
Snow instability tests, like the extended column test (ECT), provide valuable information regarding point snow instability. A large data set of ECT – together with information on slope instability – was explored. The findings clearly show that combining information regarding propagation propensity and fracture initiation provided the best correlation with slope instability. A new four-class stability interpretation scheme is proposed for ECT results.
Jürg Schweizer, Christoph Mitterer, Frank Techel, Andreas Stoffel, and Benjamin Reuter
The Cryosphere, 14, 737–750, https://doi.org/10.5194/tc-14-737-2020, https://doi.org/10.5194/tc-14-737-2020, 2020
Short summary
Short summary
Snow avalanches represent a major natural hazard in seasonally snow-covered mountain regions around the world. To avoid periods and locations of high hazard, avalanche warnings are issued by public authorities. In these bulletins, the hazard is characterized by a danger level. Since the danger levels are not well defined, we analyzed a large data set of avalanches to improve the description. Our findings show discrepancies in present usage of the danger scale and show ways to improve the scale.
Cristina Pérez-Guillén, Kae Tsunematsu, Kouichi Nishimura, and Dieter Issler
Earth Surf. Dynam., 7, 989–1007, https://doi.org/10.5194/esurf-7-989-2019, https://doi.org/10.5194/esurf-7-989-2019, 2019
Short summary
Short summary
Avalanches and slush flows from Mt. Fuji are a major natural hazard as they may attain run-out distances of up to 4 km and destroy parts of the forest and infrastructure. We located and tracked them for the first time using seismic data. Numerical simulations were conducted to assess the precision of the seismic tracking. We also inferred dynamical properties characterizing these hazardous mass movements. This information is indispensable for assessing avalanche risk in the Mt. Fuji region.
Frank Techel, Christoph Mitterer, Elisabetta Ceaglio, Cécile Coléou, Samuel Morin, Francesca Rastelli, and Ross S. Purves
Nat. Hazards Earth Syst. Sci., 18, 2697–2716, https://doi.org/10.5194/nhess-18-2697-2018, https://doi.org/10.5194/nhess-18-2697-2018, 2018
Short summary
Short summary
In 1993, the European Avalanche Warning Services agreed upon a common danger scale to describe the regional avalanche hazard: the European Avalanche Danger Scale. Using published avalanche forecasts, we explored whether forecasters use the scale consistently. We noted differences in the use of the danger levels, some of which could be linked to the size of the regions a regional danger level is issued for. We recommend further harmonizing the avalanche forecast products in the Alps.
Alexandre Badoux, Norina Andres, Frank Techel, and Christoph Hegg
Nat. Hazards Earth Syst. Sci., 16, 2747–2768, https://doi.org/10.5194/nhess-16-2747-2016, https://doi.org/10.5194/nhess-16-2747-2016, 2016
Short summary
Short summary
A database of fatalities caused by natural hazards in Switzerland was compiled for the period from 1946 to 2015: in 70 years, 635 events occurred causing 1023 fatalities. The most common causes of death were snow avalanches (37 %), followed by lightning (16 %), floods (12 %), windstorms (10 %), rockfalls (8 %) and landslides (7 %). The annual number of victims showed a distinct decrease over time. In comparison to other countries, the natural hazard mortality rate in Switzerland is quite low.
Frank Techel, Frédéric Jarry, Georg Kronthaler, Susanna Mitterer, Patrick Nairz, Miha Pavšek, Mauro Valt, and Gian Darms
Geogr. Helv., 71, 147–159, https://doi.org/10.5194/gh-71-147-2016, https://doi.org/10.5194/gh-71-147-2016, 2016
Short summary
Short summary
During the last 45 years, about 100 people lost their lives in avalanches in the European Alps each year. Avalanche fatalities in settlements and on transportation corridors have considerably decreased since the 1970s. In contrast, the number of avalanche fatalities during recreational activities away from avalanche-secured terrain doubled between the 1960s and 1980s and has remained relatively stable since, despite a continuing strong increase in winter backcountry recreational activities.
F. Techel, B. Zweifel, and K. Winkler
Nat. Hazards Earth Syst. Sci., 15, 1985–1997, https://doi.org/10.5194/nhess-15-1985-2015, https://doi.org/10.5194/nhess-15-1985-2015, 2015
Short summary
Short summary
We present a spatiotemporal picture of winter backcountry usage in the Swiss Alps and compare this with the distribution of avalanche accidents.
Critical avalanche danger conditions and an unfavorable snowpack (old snow problem) strongly increase the risk of winter backcountry recreationists to be involved in a severe avalanche accident. This explains why there are comparably more accidents in the inneralpine regions with less activity.
F. Techel and C. Pielmeier
Nat. Hazards Earth Syst. Sci., 14, 779–787, https://doi.org/10.5194/nhess-14-779-2014, https://doi.org/10.5194/nhess-14-779-2014, 2014
Related subject area
Other Hazards (e.g., Glacial and Snow Hazards, Karst, Wildfires Hazards, and Medical Geo-Hazards)
Equivalent hazard magnitude scale
Statistical modelling of air quality impacts from individual forest fires in New South Wales, Australia
Drivers of extreme burnt area in Portugal: fire weather and vegetation
Coupling wildfire spread simulations and connectivity analysis for hazard assessment: a case study in Serra da Cabreira, Portugal
Glacial lake outburst flood hazard under current and future conditions: worst-case scenarios in a transboundary Himalayan basin
What weather variables are important for wet and slab avalanches under a changing climate in a low-altitude mountain range in Czechia?
Modelling ignition probability for human- and lightning-caused wildfires in Victoria, Australia
Automated snow avalanche release area delineation in data-sparse, remote, and forested regions
The 2017 Split wildfire in Croatia: evolution and the role of meteorological conditions
Progress and challenges in glacial lake outburst flood research (2017–2021): a research community perspective
Global assessment and mapping of ecological vulnerability to wildfires
The impact of terrain model source and resolution on snow avalanche modeling
Temporal evolution of crack propagation characteristics in a weak snowpack layer: conditions of crack arrest and sustained propagation
Travel and terrain advice statements in public avalanche bulletins: a quantitative analysis of who uses this information, what makes it useful, and how it can be improved for users
Data-driven automated predictions of the avalanche danger level for dry-snow conditions in Switzerland
Automated avalanche hazard indication mapping on a statewide scale
Forecasting the regional fire radiative power for regularly ignited vegetation fires
Environmental factors affecting wildfire-burned areas in southeastern France, 1970–2019
Detrainment and braking of snow avalanches interacting with forests
Characterizing the Rate of Spread of Wildfires in Emerging Fire Environments of Northwestern Europe
Past and future trends in fire weather for the UK
Methodological and conceptual challenges in rare and severe event forecast verification
Multi-method monitoring of rockfall activity along the classic route up Mont Blanc (4809 m a.s.l.) to encourage adaptation by mountaineers
Wildfire–atmosphere interaction index for extreme-fire behaviour
How is avalanche danger described in textual descriptions in avalanche forecasts in Switzerland? Consistency between forecasters and avalanche danger
A data-driven prediction model for Fennoscandian wildfires
Data-based wildfire risk model for Mediterranean ecosystems – case study of the Concepción metropolitan area in central Chile
The mud volcanoes at Santa Barbara and Aragona (Sicily, Italy): a contribution to risk assessment
Impact of information presentation on interpretability of spatial hazard information: lessons from a study in avalanche safety
ABWiSE v1.0: toward an agent-based approach to simulating wildfire spread
Multi-decadal geomorphic changes of a low-angle valley glacier in the East Kunlun Mountains: remote sensing observations and detachment hazard assessment
Spatial and temporal subsidence characteristics in Wuhan (China), during 2015–2019, inferred from Sentinel-1 synthetic aperture radar (SAR) interferometry
Formation, evolution, and drainage of short-lived glacial lakes in permafrost environments of the northern Teskey Range, Central Asia
Towards a compound-event-oriented climate model evaluation: a decomposition of the underlying biases in multivariate fire and heat stress hazards
Assessing the effect of lithological setting, block characteristics and slope topography on the runout length of rockfalls in the Alps and on the island of La Réunion
Evolution of surface deformation related to salt-extraction-caused sinkholes in Solotvyno (Ukraine) revealed by Sentinel-1 radar interferometry
Attribution of the Australian bushfire risk to anthropogenic climate change
Synoptic atmospheric circulation patterns associated with deep persistent slab avalanches in the western United States
A regional spatiotemporal analysis of large magnitude snow avalanches using tree rings
Examining the operational use of avalanche problems with decision trees and model-generated weather and snowpack variables
A classification scheme to determine wildfires from the satellite record in the cool grasslands of southern Canada: considerations for fire occurrence modelling and warning criteria
Assessments of land subsidence along the Rizhao–Lankao high-speed railway at Heze, China, between 2015 and 2019 with Sentinel-1 data
Tailings-flow runout analysis: examining the applicability of a semi-physical area–volume relationship using a novel database
Experimental assessment of the relationship between rainfall intensity and sinkholes caused by damaged sewer pipes
Non-stationary extreme value analysis of ground snow loads in the French Alps: a comparison with building standards
Sensitivity of modeled snow stability data to meteorological input uncertainty
Fire Weather Index: the skill provided by the European Centre for Medium-Range Weather Forecasts ensemble prediction system
The 1958 Lituya Bay tsunami – pre-event bathymetry reconstruction and 3D numerical modelling utilising the computational fluid dynamics software Flow-3D
On snow stability interpretation of extended column test results
Snow avalanche detection and mapping in multitemporal and multiorbital radar images from TerraSAR-X and Sentinel-1
Yi Victor Wang and Antonia Sebastian
Nat. Hazards Earth Syst. Sci., 22, 4103–4118, https://doi.org/10.5194/nhess-22-4103-2022, https://doi.org/10.5194/nhess-22-4103-2022, 2022
Short summary
Short summary
In this article, we propose an equivalent hazard magnitude scale and a method to evaluate and compare the strengths of natural hazard events across different hazard types, including earthquakes, tsunamis, floods, droughts, forest fires, tornadoes, cold waves, heat waves, and tropical cyclones. With our method, we determine that both the February 2021 North American cold wave event and Hurricane Harvey in 2017 were equivalent to a magnitude 7.5 earthquake in hazard strength.
Michael A. Storey and Owen F. Price
Nat. Hazards Earth Syst. Sci., 22, 4039–4062, https://doi.org/10.5194/nhess-22-4039-2022, https://doi.org/10.5194/nhess-22-4039-2022, 2022
Short summary
Short summary
Models are needed to understand and predict pollutant output from forest fires so fire agencies can reduce smoke-related risks to human health. We modelled air quality (PM2.5) based on fire area and weather variables. We found fire area and boundary layer height were influential on predictions, with distance, temperature, wind speed and relative humidity also important. The models predicted reasonably accurately in comparison to other existing methods but would benefit from further development.
Tomás Calheiros, Akli Benali, Mário Pereira, João Silva, and João Nunes
Nat. Hazards Earth Syst. Sci., 22, 4019–4037, https://doi.org/10.5194/nhess-22-4019-2022, https://doi.org/10.5194/nhess-22-4019-2022, 2022
Short summary
Short summary
Fire weather indices are used to assess the effect of weather on wildfires. Fire weather risk was computed and combined with large wildfires in Portugal. Results revealed the influence of vegetation cover: municipalities with a prevalence of shrublands, located in eastern parts, burnt under less extreme conditions than those with higher forested areas, situated in coastal regions. These findings are a novelty for fire science in Portugal and should be considered for fire management.
Ana C. L. Sá, Bruno Aparicio, Akli Benali, Chiara Bruni, Michele Salis, Fábio Silva, Martinho Marta-Almeida, Susana Pereira, Alfredo Rocha, and José Pereira
Nat. Hazards Earth Syst. Sci., 22, 3917–3938, https://doi.org/10.5194/nhess-22-3917-2022, https://doi.org/10.5194/nhess-22-3917-2022, 2022
Short summary
Short summary
Assessing landscape wildfire connectivity supported by wildfire spread simulations can improve fire hazard assessment and fuel management plans. Weather severity determines the degree of fuel patch connectivity and thus the potential to spread large and intense wildfires. Mapping highly connected patches in the landscape highlights patch candidates for prior fuel treatments, which ultimately will contribute to creating fire-resilient Mediterranean landscapes.
Simon K. Allen, Ashim Sattar, Owen King, Guoqing Zhang, Atanu Bhattacharya, Tandong Yao, and Tobias Bolch
Nat. Hazards Earth Syst. Sci., 22, 3765–3785, https://doi.org/10.5194/nhess-22-3765-2022, https://doi.org/10.5194/nhess-22-3765-2022, 2022
Short summary
Short summary
This study demonstrates how the threat of a very large outburst from a future lake can be feasibly assessed alongside that from current lakes to inform disaster risk management within a transboundary basin between Tibet and Nepal. Results show that engineering measures and early warning systems would need to be coupled with effective land use zoning and programmes to strengthen local response capacities in order to effectively reduce the risk associated with current and future outburst events.
Markéta Součková, Roman Juras, Kryštof Dytrt, Vojtěch Moravec, Johanna Ruth Blöcher, and Martin Hanel
Nat. Hazards Earth Syst. Sci., 22, 3501–3525, https://doi.org/10.5194/nhess-22-3501-2022, https://doi.org/10.5194/nhess-22-3501-2022, 2022
Short summary
Short summary
Avalanches are natural hazards that threaten people and infrastructure. With climate change, avalanche activity is changing. We analysed the change in frequency and size of avalanches in the Krkonoše Mountains, Czechia, and detected important variables with machine learning tools from 1979–2020. Wet avalanches in February and March have increased, and slab avalanches have decreased and become smaller. The identified variables and their threshold levels may help in avalanche decision-making.
Annalie Dorph, Erica Marshall, Kate A. Parkins, and Trent D. Penman
Nat. Hazards Earth Syst. Sci., 22, 3487–3499, https://doi.org/10.5194/nhess-22-3487-2022, https://doi.org/10.5194/nhess-22-3487-2022, 2022
Short summary
Short summary
Wildfire spatial patterns are determined by fire ignition sources and vegetation fuel moisture. Fire ignitions can be mediated by humans (owing to proximity to human infrastructure) or caused by lightning (owing to fuel moisture, average annual rainfall and local weather). When moisture in dead vegetation is below 20 % the probability of a wildfire increases. The results of this research enable accurate spatial mapping of ignition probability to aid fire suppression efforts and future research.
John Sykes, Pascal Haegeli, and Yves Bühler
Nat. Hazards Earth Syst. Sci., 22, 3247–3270, https://doi.org/10.5194/nhess-22-3247-2022, https://doi.org/10.5194/nhess-22-3247-2022, 2022
Short summary
Short summary
Automated snow avalanche terrain mapping provides an efficient method for large-scale assessment of avalanche hazards, which informs risk management decisions for transportation and recreation. This research reduces the cost of developing avalanche terrain maps by using satellite imagery and open-source software as well as improving performance in forested terrain. The research relies on local expertise to evaluate accuracy, so the methods are broadly applicable in mountainous regions worldwide.
Ivana Čavlina Tomašević, Kevin K. W. Cheung, Višnjica Vučetić, Paul Fox-Hughes, Kristian Horvath, Maja Telišman Prtenjak, Paul J. Beggs, Barbara Malečić, and Velimir Milić
Nat. Hazards Earth Syst. Sci., 22, 3143–3165, https://doi.org/10.5194/nhess-22-3143-2022, https://doi.org/10.5194/nhess-22-3143-2022, 2022
Short summary
Short summary
One of the most severe and impactful urban wildfire events in Croatian history has been reconstructed and analyzed. The study identified some important meteorological influences related to the event: the synoptic conditions of the Azores anticyclone, cold front, and upper-level shortwave trough all led to the highest fire weather index in 2017. A low-level jet, locally known as bura wind that can be explained by hydraulic jump theory, was the dynamic trigger of the event.
Adam Emmer, Simon K. Allen, Mark Carey, Holger Frey, Christian Huggel, Oliver Korup, Martin Mergili, Ashim Sattar, Georg Veh, Thomas Y. Chen, Simon J. Cook, Mariana Correas-Gonzalez, Soumik Das, Alejandro Diaz Moreno, Fabian Drenkhan, Melanie Fischer, Walter W. Immerzeel, Eñaut Izagirre, Ramesh Chandra Joshi, Ioannis Kougkoulos, Riamsara Kuyakanon Knapp, Dongfeng Li, Ulfat Majeed, Stephanie Matti, Holly Moulton, Faezeh Nick, Valentine Piroton, Irfan Rashid, Masoom Reza, Anderson Ribeiro de Figueiredo, Christian Riveros, Finu Shrestha, Milan Shrestha, Jakob Steiner, Noah Walker-Crawford, Joanne L. Wood, and Jacob C. Yde
Nat. Hazards Earth Syst. Sci., 22, 3041–3061, https://doi.org/10.5194/nhess-22-3041-2022, https://doi.org/10.5194/nhess-22-3041-2022, 2022
Short summary
Short summary
Glacial lake outburst floods (GLOFs) have attracted increased research attention recently. In this work, we review GLOF research papers published between 2017 and 2021 and complement the analysis with research community insights gained from the 2021 GLOF conference we organized. The transdisciplinary character of the conference together with broad geographical coverage allowed us to identify progress, trends and challenges in GLOF research and outline future research needs and directions.
Fátima Arrogante-Funes, Inmaculada Aguado, and Emilio Chuvieco
Nat. Hazards Earth Syst. Sci., 22, 2981–3003, https://doi.org/10.5194/nhess-22-2981-2022, https://doi.org/10.5194/nhess-22-2981-2022, 2022
Short summary
Short summary
We show that ecological value might be reduced by 50 % due to fire perturbation in ecosystems that have not developed in the presence of fire and/or that present changes in the fire regime. The biomes most affected are tropical and subtropical forests, tundra, and mangroves. Integration of biotic and abiotic fire regime and regeneration factors resulted in a powerful way to map ecological vulnerability to fire and develop assessments to generate adaptation plans of management in forest masses.
Aubrey Miller, Pascal Sirguey, Simon Morris, Perry Bartelt, Nicolas Cullen, Todd Redpath, Kevin Thompson, and Yves Bühler
Nat. Hazards Earth Syst. Sci., 22, 2673–2701, https://doi.org/10.5194/nhess-22-2673-2022, https://doi.org/10.5194/nhess-22-2673-2022, 2022
Short summary
Short summary
Natural hazard modelers simulate mass movements to better anticipate the risk to people and infrastructure. These simulations require accurate digital elevation models. We test the sensitivity of a well-established snow avalanche model (RAMMS) to the source and spatial resolution of the elevation model. We find key differences in the digital representation of terrain greatly affect the simulated avalanche results, with implications for hazard planning.
Bastian Bergfeld, Alec van Herwijnen, Grégoire Bobillier, Philipp L. Rosendahl, Philipp Weißgraeber, Valentin Adam, Jürg Dual, and Jürg Schweizer
Nat. Hazards Earth Syst. Sci. Discuss., https://doi.org/10.5194/nhess-2022-161, https://doi.org/10.5194/nhess-2022-161, 2022
Revised manuscript accepted for NHESS
Short summary
Short summary
For a slab avalanche to release, the snowpack must facilitate crack propagation over large distances. Field measurements on crack propagation at this scale are very scarce. We performed a series experiments, up to ten meters long, over a period of 10 weeks. Beside the temporal evolution of the mechanical properties of the snowpack, measured crack speeds were highest for PSTs resulting in full propagation. Based on these findings, an index for self-sustained crack propagation is proposed.
Kathryn C. Fisher, Pascal Haegeli, and Patrick Mair
Nat. Hazards Earth Syst. Sci., 22, 1973–2000, https://doi.org/10.5194/nhess-22-1973-2022, https://doi.org/10.5194/nhess-22-1973-2022, 2022
Short summary
Short summary
Avalanche bulletins include travel and terrain statements to provide recreationists with tangible guidance about how to apply the hazard information. We examined which bulletin users pay attention to these statements, what determines their usefulness, and how they could be improved. Our study shows that reducing jargon and adding simple explanations can significantly improve the usefulness of the statements for users with lower levels of avalanche awareness education who depend on this advice.
Cristina Pérez-Guillén, Frank Techel, Martin Hendrick, Michele Volpi, Alec van Herwijnen, Tasko Olevski, Guillaume Obozinski, Fernando Pérez-Cruz, and Jürg Schweizer
Nat. Hazards Earth Syst. Sci., 22, 2031–2056, https://doi.org/10.5194/nhess-22-2031-2022, https://doi.org/10.5194/nhess-22-2031-2022, 2022
Short summary
Short summary
A fully data-driven approach to predicting the danger level for dry-snow avalanche conditions in Switzerland was developed. Two classifiers were trained using a large database of meteorological data, snow cover simulations, and danger levels. The models performed well throughout the Swiss Alps, reaching a performance similar to the current experience-based avalanche forecasts. This approach shows the potential to be a valuable supplementary decision support tool for assessing avalanche hazard.
Yves Bühler, Peter Bebi, Marc Christen, Stefan Margreth, Lukas Stoffel, Andreas Stoffel, Christoph Marty, Gregor Schmucki, Andrin Caviezel, Roderick Kühne, Stephan Wohlwend, and Perry Bartelt
Nat. Hazards Earth Syst. Sci., 22, 1825–1843, https://doi.org/10.5194/nhess-22-1825-2022, https://doi.org/10.5194/nhess-22-1825-2022, 2022
Short summary
Short summary
To calculate and visualize the potential avalanche hazard, we develop a method that automatically and efficiently pinpoints avalanche starting zones and simulate their runout for the entire canton of Grisons. The maps produced in this way highlight areas that could be endangered by avalanches and are extremely useful in multiple applications for the cantonal authorities, including the planning of new infrastructure, making alpine regions more safe.
Tero M. Partanen and Mikhail Sofiev
Nat. Hazards Earth Syst. Sci., 22, 1335–1346, https://doi.org/10.5194/nhess-22-1335-2022, https://doi.org/10.5194/nhess-22-1335-2022, 2022
Short summary
Short summary
The presented method aims to forecast regional wildfire-emitted radiative power in a time-dependent manner several days in advance. The temporal fire radiative power can be converted to an emission production rate, which can be implemented in air quality forecasting simulations. It is shown that in areas with a high incidence of wildfires, the fire radiative power is quite predictable, but otherwise it is not.
Christos Bountzouklis, Dennis M. Fox, and Elena Di Bernardino
Nat. Hazards Earth Syst. Sci., 22, 1181–1200, https://doi.org/10.5194/nhess-22-1181-2022, https://doi.org/10.5194/nhess-22-1181-2022, 2022
Short summary
Short summary
The study addresses the evolution of burned areas in southeastern France from 1970 to 2019 through the scope of a firefighting policy shift in 1994 that resulted in a significant decrease in the burned area. Regions with large fires were particularly impacted, whereas, in other areas, the fires remained frequent and occurred closer to built-up zones. Environmental characteristics such as south-facing slopes and low vegetation (bushes) are increasingly associated with burned areas.
Louis Védrine, Xingyue Li, and Johan Gaume
Nat. Hazards Earth Syst. Sci., 22, 1015–1028, https://doi.org/10.5194/nhess-22-1015-2022, https://doi.org/10.5194/nhess-22-1015-2022, 2022
Short summary
Short summary
This study investigates how forests affect the behaviour of snow avalanches through the evaluation of the amount of snow stopped by the trees and the analysis of energy dissipation mechanisms. Different avalanche features and tree configurations have been examined, leading to the proposal of a unified law for the detrained snow mass. Outcomes from this study can be directly implemented in operational models for avalanche risk assessment and contribute to improved forest management strategy.
Victor Mario Tapia, Santiago Monedero, Kerryn Little, Sergio de-Miguel, Cathelijne Stoof, and Adrián Cardíl
Nat. Hazards Earth Syst. Sci. Discuss., https://doi.org/10.5194/nhess-2022-47, https://doi.org/10.5194/nhess-2022-47, 2022
Revised manuscript accepted for NHESS
Short summary
Short summary
This study aims to better understand fire behavior in northwest Europe, a temperate region with a projected increase in wildfire risk. We propose a new method to identify wildfire rate of spread from satellites. Results indicate that there is a peak in the area burned and rate of spread in the months of April and May. Knowledge of wildfire rate of spread is important for evaluating periods of elevated fire risk, available suppression methods, as well as land management strategies.
Matthew C. Perry, Emilie Vanvyve, Richard A. Betts, and Erika J. Palin
Nat. Hazards Earth Syst. Sci., 22, 559–575, https://doi.org/10.5194/nhess-22-559-2022, https://doi.org/10.5194/nhess-22-559-2022, 2022
Short summary
Short summary
In the past, wildfires in the UK have occurred mainly in spring, with occasional events during hot, dry summers. Climate models predict a large future increase in hazardous fire weather conditions in summer. Wildfire can be considered an
emergent riskfor the UK, as past events have not had widespread major impacts, but this could change. The large increase in risk between the 2 °C and 4 °C levels of global warming highlights the importance of global efforts to keep warming below 2 °C.
Philip A. Ebert and Peter Milne
Nat. Hazards Earth Syst. Sci., 22, 539–557, https://doi.org/10.5194/nhess-22-539-2022, https://doi.org/10.5194/nhess-22-539-2022, 2022
Short summary
Short summary
There is no consensus about how to assess the quality of binary (yes or no) rare and severe event forecasts, i.e. forecasts involving natural hazards like tornadoes or avalanches. We offer a comprehensive overview of the challenges we face when making such an assessment and provide a critical review of existing solutions. We argue against all but one existing solution to assess the quality of such forecasts and present practical consequences to improve forecasting services.
Jacques Mourey, Pascal Lacroix, Pierre-Allain Duvillard, Guilhem Marsy, Marco Marcer, Emmanuel Malet, and Ludovic Ravanel
Nat. Hazards Earth Syst. Sci., 22, 445–460, https://doi.org/10.5194/nhess-22-445-2022, https://doi.org/10.5194/nhess-22-445-2022, 2022
Short summary
Short summary
More frequent rockfalls in high alpine environments due to climate change are a growing threat to mountaineers. This hazard is particularly important on the classic route up Mont Blanc. Our results show that rockfalls are most frequent during snowmelt periods and the warmest hours of the day, and that mountaineers do not adapt to the local rockfall hazard when planning their ascent. Disseminating the knowledge acquired from our study caused management measures to be implemented for the route.
Tomàs Artés, Marc Castellnou, Tracy Houston Durrant, and Jesús San-Miguel
Nat. Hazards Earth Syst. Sci., 22, 509–522, https://doi.org/10.5194/nhess-22-509-2022, https://doi.org/10.5194/nhess-22-509-2022, 2022
Short summary
Short summary
During the last 20 years extreme wildfires have challenged firefighting capabilities. Several fire danger indices are routinely used by firefighting services but are not suited to forecast convective extreme wildfire behaviour at the global scale. This article proposes a new fire danger index for deep moist convection, the extreme-fire behaviour index (EFBI), based on the analysis of the vertical profiles of the atmosphere above wildfires to use along with traditional fire danger indices.
Veronika Hutter, Frank Techel, and Ross S. Purves
Nat. Hazards Earth Syst. Sci., 21, 3879–3897, https://doi.org/10.5194/nhess-21-3879-2021, https://doi.org/10.5194/nhess-21-3879-2021, 2021
Short summary
Short summary
How is avalanche danger described in public avalanche forecasts? We analyzed 6000 textual descriptions of avalanche danger in Switzerland, taking the perspective of the forecaster. Avalanche danger was described rather consistently, although the results highlight the difficulty of communicating conditions that are neither rare nor frequent, neither small nor large. The study may help to refine the ways in which avalanche danger could be communicated to the public.
Sigrid Jørgensen Bakke, Niko Wanders, Karin van der Wiel, and Lena Merete Tallaksen
Nat. Hazards Earth Syst. Sci. Discuss., https://doi.org/10.5194/nhess-2021-384, https://doi.org/10.5194/nhess-2021-384, 2021
Revised manuscript accepted for NHESS
Short summary
Short summary
In this study, we developed a machine learning model to identify dominant controls of wildfire in Fennoscandia, and produce monthly fire danger probability maps. The dominant control was shallow soil water anomaly, followed by air temperature and deep soil water. The model proved skilful with a similar performance as the existing Canadian Fire Weather Index. We highlight the benefit of using data-driven models jointly with other fire models to improve fire monitoring and prediction.
Edilia Jaque Castillo, Alfonso Fernández, Rodrigo Fuentes Robles, and Carolina G. Ojeda
Nat. Hazards Earth Syst. Sci., 21, 3663–3678, https://doi.org/10.5194/nhess-21-3663-2021, https://doi.org/10.5194/nhess-21-3663-2021, 2021
Short summary
Short summary
Wildfires pose risks to lives and livelihoods in many regions of the world. Particularly in Chile's central-south region, climate change, widespread land use change, and urban growth tend to increase the likelihood of fire occurrence. Our work focused on the Concepción metropolitan area, where we developed a model using machine learning in order to map wildfire risks. We found that the interface between urban areas and forestry plantations presents the highest risks.
Alessandro Gattuso, Francesco Italiano, Giorgio Capasso, Antonino D'Alessandro, Fausto Grassa, Antonino Fabio Pisciotta, and Davide Romano
Nat. Hazards Earth Syst. Sci., 21, 3407–3419, https://doi.org/10.5194/nhess-21-3407-2021, https://doi.org/10.5194/nhess-21-3407-2021, 2021
Short summary
Short summary
Santa Barbara and Aragona are affected by mud volcanism with episodic hazardous paroxysm events. Two potentially hazardous paroxysm exposed surfaces of 0.12 and 0.20 km2 were elaborated with DSMs and with historical information on the paroxysms that occurred in the past. This paper, in the end, could be a useful tool for civil protection authorities in order to take appropriate risk mitigation measurements for exposed people and for monitoring activities.
Kathryn C. Fisher, Pascal Haegeli, and Patrick Mair
Nat. Hazards Earth Syst. Sci., 21, 3219–3242, https://doi.org/10.5194/nhess-21-3219-2021, https://doi.org/10.5194/nhess-21-3219-2021, 2021
Short summary
Short summary
Avalanche warning services publish condition reports to help backcountry recreationists make informed decisions about when and where to travel in avalanche terrain. We tested how different graphic representations of terrain information can affect users’ ability to interpret and apply the provided information. Our study shows that a combined presentation of aspect and elevation information is the most effective. These results can be used to improve avalanche risk communication products.
Jeffrey Katan and Liliana Perez
Nat. Hazards Earth Syst. Sci., 21, 3141–3160, https://doi.org/10.5194/nhess-21-3141-2021, https://doi.org/10.5194/nhess-21-3141-2021, 2021
Short summary
Short summary
Wildfires are an integral part of ecosystems worldwide, but they also pose a serious risk to human life and property. To further our understanding of wildfires and allow experimentation without recourse to live fires, this study presents an agent-based modelling approach to combine the complexity possible with physical models with the ease of computation of empirical models. Model calibration and validation show bottom-up simulation tracks the core elements of complexity of fire across scales.
Xiaowen Wang, Lin Liu, Yan Hu, Tonghua Wu, Lin Zhao, Qiao Liu, Rui Zhang, Bo Zhang, and Guoxiang Liu
Nat. Hazards Earth Syst. Sci., 21, 2791–2810, https://doi.org/10.5194/nhess-21-2791-2021, https://doi.org/10.5194/nhess-21-2791-2021, 2021
Short summary
Short summary
We characterized the multi-decadal geomorphic changes of a low-angle valley glacier in the East Kunlun Mountains and assessed the detachment hazard influence. The observations reveal a slow surge-like dynamic pattern of the glacier tongue. The maximum runout distances of two endmember avalanche scenarios were presented. This study provides a reference to evaluate the runout hazards of low-angle mountain glaciers prone to detachment.
Xuguo Shi, Shaocheng Zhang, Mi Jiang, Yuanyuan Pei, Tengteng Qu, Jinhu Xu, and Chen Yang
Nat. Hazards Earth Syst. Sci., 21, 2285–2297, https://doi.org/10.5194/nhess-21-2285-2021, https://doi.org/10.5194/nhess-21-2285-2021, 2021
Short summary
Short summary
We mapped the subsidence of Wuhan using Sentinel-1 synthetic aperture radar (SAR) images acquired during 2015–2019. Overall subsidence coincides with the distribution of engineered geological regions with soft soils, while the subsidence centers shifted with urban construction activities. Correlation between karst subsidence and concentrated rainfall was identified in Qingling–Jiangdi. Results indicate that interferometric SAR can be employed to routinely monitor and identify geohazards.
Mirlan Daiyrov and Chiyuki Narama
Nat. Hazards Earth Syst. Sci., 21, 2245–2256, https://doi.org/10.5194/nhess-21-2245-2021, https://doi.org/10.5194/nhess-21-2245-2021, 2021
Short summary
Short summary
In the Teskey Range of the Tien Shan (Kyrgyz Republic), four outburst flood disasters from short-lived glacial lakes in 2006, 2008, 2013, and 2014 caused severe damages in the downstream part. Short-lived glacial lakes grow rapidly and drain within a few months, due to closure and opening of an outlet ice tunnel in an ice-cored moraine complex at the glacier front. We investigated how short-lived glacial lakes store and drain water over short periods based on field survey and satellite data.
Roberto Villalobos-Herrera, Emanuele Bevacqua, Andreia F. S. Ribeiro, Graeme Auld, Laura Crocetti, Bilyana Mircheva, Minh Ha, Jakob Zscheischler, and Carlo De Michele
Nat. Hazards Earth Syst. Sci., 21, 1867–1885, https://doi.org/10.5194/nhess-21-1867-2021, https://doi.org/10.5194/nhess-21-1867-2021, 2021
Short summary
Short summary
Climate hazards may be caused by events which have multiple drivers. Here we present a method to break down climate model biases in hazard indicators down to the bias caused by each driving variable. Using simplified fire and heat stress indicators driven by temperature and relative humidity as examples, we show how multivariate indicators may have complex biases and that the relationship between driving variables is a source of bias that must be considered in climate model bias corrections.
Kerstin Wegner, Florian Haas, Tobias Heckmann, Anne Mangeney, Virginie Durand, Nicolas Villeneuve, Philippe Kowalski, Aline Peltier, and Michael Becht
Nat. Hazards Earth Syst. Sci., 21, 1159–1177, https://doi.org/10.5194/nhess-21-1159-2021, https://doi.org/10.5194/nhess-21-1159-2021, 2021
Short summary
Short summary
In mountainous regions rockfall is a common geomorphic process. We selected four study sites that feature different rock types. High-resolution terrestrial laser scanning data were acquired to measure the block size and block shape (axial ratio) of rockfall particles on the scree deposits. Laser scanning data were also used to characterize the morphology of these landforms. Our results show that hill slope and rock particle properties govern rock particle runout in a complex manner.
Eszter Szűcs, Sándor Gönczy, István Bozsó, László Bányai, Alexandru Szakacs, Csilla Szárnya, and Viktor Wesztergom
Nat. Hazards Earth Syst. Sci., 21, 977–993, https://doi.org/10.5194/nhess-21-977-2021, https://doi.org/10.5194/nhess-21-977-2021, 2021
Short summary
Short summary
Sinkhole formation and post-collapse deformation in the Solotvyno salt mining area was studied where the salt dissolution due to water intrusion poses a significant risk. Based on a Sentinel-1 data set, remarkable surface deformation with a maximum rate of 5 cm/yr was revealed, and it was demonstrated that the deformation process has a linear characteristic although the mining activity was ended more than 10 years ago.
Geert Jan van Oldenborgh, Folmer Krikken, Sophie Lewis, Nicholas J. Leach, Flavio Lehner, Kate R. Saunders, Michiel van Weele, Karsten Haustein, Sihan Li, David Wallom, Sarah Sparrow, Julie Arrighi, Roop K. Singh, Maarten K. van Aalst, Sjoukje Y. Philip, Robert Vautard, and Friederike E. L. Otto
Nat. Hazards Earth Syst. Sci., 21, 941–960, https://doi.org/10.5194/nhess-21-941-2021, https://doi.org/10.5194/nhess-21-941-2021, 2021
Short summary
Short summary
Southeastern Australia suffered from disastrous bushfires during the 2019/20 fire season, raising the question whether these have become more likely due to climate change. We found no attributable trend in extreme annual or monthly low precipitation but a clear shift towards more extreme heat. However, this shift is underestimated by the models. Analysing fire weather directly, we found that the chance has increased by at least 30 %, but due to the underestimation it could well be higher.
Andrew R. Schauer, Jordy Hendrikx, Karl W. Birkeland, and Cary J. Mock
Nat. Hazards Earth Syst. Sci., 21, 757–774, https://doi.org/10.5194/nhess-21-757-2021, https://doi.org/10.5194/nhess-21-757-2021, 2021
Short summary
Short summary
Our research links upper atmospheric circulation patterns to a destructive and difficult-to-predict type of snow avalanche in the western United States. At each of our study sites, we find unique circulation patterns that tend to occur at the beginning of the winter season during years with major avalanche activity. We also find specific patterns that occur frequently in the days leading to major avalanche events. This work will enable practitioners to better anticipate these challenging events.
Erich Peitzsch, Jordy Hendrikx, Daniel Stahle, Gregory Pederson, Karl Birkeland, and Daniel Fagre
Nat. Hazards Earth Syst. Sci., 21, 533–557, https://doi.org/10.5194/nhess-21-533-2021, https://doi.org/10.5194/nhess-21-533-2021, 2021
Short summary
Short summary
We sampled 647 trees from 12 avalanche paths to investigate large snow avalanches over the past 400 years in the northern Rocky Mountains, USA. Sizable avalanches occur approximately every 3 years across the region. Our results emphasize the importance of sample size, scale, and spatial extent when reconstructing avalanche occurrence across a region. This work can be used for infrastructure planning and avalanche forecasting operations.
Simon Horton, Moses Towell, and Pascal Haegeli
Nat. Hazards Earth Syst. Sci., 20, 3551–3576, https://doi.org/10.5194/nhess-20-3551-2020, https://doi.org/10.5194/nhess-20-3551-2020, 2020
Short summary
Short summary
We investigate patterns in how avalanche forecasters characterize snow avalanche hazard with avalanche problem types. Decision tree analysis was used to investigate both physical influences based on weather and on snowpack variables and operational practices. The results highlight challenges with developing decision aids based on previous hazard assessments.
Dan K. Thompson and Kimberly Morrison
Nat. Hazards Earth Syst. Sci., 20, 3439–3454, https://doi.org/10.5194/nhess-20-3439-2020, https://doi.org/10.5194/nhess-20-3439-2020, 2020
Short summary
Short summary
We describe critically low relative humidity and high wind speeds above which only documented wildfires were seen to occur and where no agricultural fires were documented in southern Canada. We then applied these thresholds to the much larger satellite record from 2002–2018 to quantify regional differences in both the rate of observed burning and the number of days with critical weather conditions to sustain a wildfire in this grassland and agricultural region.
Chuanguang Zhu, Wenhao Wu, Mahdi Motagh, Liya Zhang, Zongli Jiang, and Sichun Long
Nat. Hazards Earth Syst. Sci., 20, 3399–3411, https://doi.org/10.5194/nhess-20-3399-2020, https://doi.org/10.5194/nhess-20-3399-2020, 2020
Short summary
Short summary
We investigate the contemporary ground deformation along the RLHR-HZ using Sentinel-1 data and find that the RLHR-HZ runs through two main subsidence areas. A total length of 35 km of the RLSR-HZ is affected by the two subsidence basins. Considering the previous investigation coupled with information on human activities, we conclude that the subsidence is mainly caused by extraction of groundwater and underground mining.
Negar Ghahramani, Andrew Mitchell, Nahyan M. Rana, Scott McDougall, Stephen G. Evans, and W. Andy Take
Nat. Hazards Earth Syst. Sci., 20, 3425–3438, https://doi.org/10.5194/nhess-20-3425-2020, https://doi.org/10.5194/nhess-20-3425-2020, 2020
Short summary
Short summary
Tailings flows result from the breach of tailings dams. These flows contain waste products of the mineral processing operations and can travel substantial distances, causing significant loss of life, environmental damage, and economic costs. This paper establishes a new tailings-flow runout classification system, describes a new database of events that have been mapped in detail using the new system, and examines the applicability of a semi-physical area–volume relationship using the new data.
Tae-Young Kwak, Sang-Inn Woo, Choong-Ki Chung, and Joonyoung Kim
Nat. Hazards Earth Syst. Sci., 20, 3343–3359, https://doi.org/10.5194/nhess-20-3343-2020, https://doi.org/10.5194/nhess-20-3343-2020, 2020
Short summary
Short summary
In this study, model tests were used to analyze the effects of rainfall intensity on the formation of the eroded zone and the occurrence of sinkholes due to groundwater infiltration through pipe defects. The model tests were conducted to simulate the actual site conditions considering the soil used around sewer pipe networks and the sewer pipe landfill standards. The groundwater level was applied to the model tests by setting three hydraulic heads based on heavy-rainfall characteristics.
Erwan Le Roux, Guillaume Evin, Nicolas Eckert, Juliette Blanchet, and Samuel Morin
Nat. Hazards Earth Syst. Sci., 20, 2961–2977, https://doi.org/10.5194/nhess-20-2961-2020, https://doi.org/10.5194/nhess-20-2961-2020, 2020
Short summary
Short summary
To minimize the risk of structure collapse due to extreme snow loads, structure standards rely on 50-year return levels of ground snow load (GSL), i.e. levels exceeded once every 50 years on average, that do not account for climate change. We study GSL data in the French Alps massifs from 1959 and 2019 and find that these 50-year return levels are decreasing with time between 900 and 4800 m of altitude, but they still exceed return levels of structure standards for half of the massifs at 1800 m.
Bettina Richter, Alec van Herwijnen, Mathias W. Rotach, and Jürg Schweizer
Nat. Hazards Earth Syst. Sci., 20, 2873–2888, https://doi.org/10.5194/nhess-20-2873-2020, https://doi.org/10.5194/nhess-20-2873-2020, 2020
Short summary
Short summary
We investigated the sensitivity of modeled snow instability to uncertainties in meteorological input, typically found in complex terrain. The formation of the weak layer was very robust due to the long dry period, indicated by a widespread avalanche problem. Once a weak layer has formed, precipitation mostly determined slab and weak layer properties and hence snow instability. When spatially assessing snow instability for avalanche forecasting, accurate precipitation patterns have to be known.
Francesca Di Giuseppe, Claudia Vitolo, Blazej Krzeminski, Christopher Barnard, Pedro Maciel, and Jesús San-Miguel
Nat. Hazards Earth Syst. Sci., 20, 2365–2378, https://doi.org/10.5194/nhess-20-2365-2020, https://doi.org/10.5194/nhess-20-2365-2020, 2020
Short summary
Short summary
Forecasting of daily fire weather indices driven by the ECMWF ensemble prediction system is shown to have a good skill up to 10 d ahead in predicting flammable conditions in most regions of the world. The availability of these forecasts through the Copernicus Emergency Management Service can extend early warnings by up to 1–2 weeks, allowing for greater proactive coordination of resource-sharing and mobilization within and across countries.
Andrea Franco, Jasper Moernaut, Barbara Schneider-Muntau, Michael Strasser, and Bernhard Gems
Nat. Hazards Earth Syst. Sci., 20, 2255–2279, https://doi.org/10.5194/nhess-20-2255-2020, https://doi.org/10.5194/nhess-20-2255-2020, 2020
Short summary
Short summary
This study highlights the use of the software Flow-3D in reproducing landslide-generated impulse waves. Due to the available data and the possibility of comparing the results with other previous works, a numerical modelling investigation on the 1958 Lituya Bay tsunami event is proposed. It is noted that the rockslide impact into the waterbody has a key role in the wave initiation and thus its propagation. The concept used in this work can be applied to prevent such phenomena in future.
Frank Techel, Kurt Winkler, Matthias Walcher, Alec van Herwijnen, and Jürg Schweizer
Nat. Hazards Earth Syst. Sci., 20, 1941–1953, https://doi.org/10.5194/nhess-20-1941-2020, https://doi.org/10.5194/nhess-20-1941-2020, 2020
Short summary
Short summary
Snow instability tests, like the extended column test (ECT), provide valuable information regarding point snow instability. A large data set of ECT – together with information on slope instability – was explored. The findings clearly show that combining information regarding propagation propensity and fracture initiation provided the best correlation with slope instability. A new four-class stability interpretation scheme is proposed for ECT results.
Silvan Leinss, Raphael Wicki, Sämi Holenstein, Simone Baffelli, and Yves Bühler
Nat. Hazards Earth Syst. Sci., 20, 1783–1803, https://doi.org/10.5194/nhess-20-1783-2020, https://doi.org/10.5194/nhess-20-1783-2020, 2020
Short summary
Short summary
To assess snow avalanche mapping with radar satellites in Switzerland, we compare 2 m resolution TerraSAR-X images, 10 m resolution Sentinel-1 images, and optical 1.5 m resolution SPOT-6 images. We found that radar satellites provide a valuable option to map at least larger avalanches, though avalanches are mapped only partially. By combining multiple orbits and polarizations from S1, we achieved mapping results of quality almost comparable to single high-resolution TerraSAR-X images.
Cited articles
Birkeland, K.: Spatial patterns of snow stability through a small mountain
range, J. Glaciol., 47, 176–186, https://doi.org/10.3189/172756501781832250,
2001. a
Breiman, L.: Random forests, Mach. Learn., 45, 5–32,
https://doi.org/10.1023/A:1010933404324, 2001. a
Bühler, Y., von Rickenbach, D., Stoffel, A., Margreth, S., Stoffel, L., and Christen, M.: Automated snow avalanche release area delineation – validation of existing algorithms and proposition of a new object-based approach for large-scale hazard indication mapping, Nat. Hazards Earth Syst. Sci., 18, 3235–3251, https://doi.org/10.5194/nhess-18-3235-2018, 2018. a, b, c
EAWS: Standards: avalanche size,
https://www.avalanches.org/standards/avalanche-size/ (last
access: 13 May 2022), 2019. a
EAWS: Standards: Avalanche danger scale,
https://www.avalanches.org/standards/avalanche-danger-scale/,
last access: 3 November 2020. a
EAWS: Definition of avalanche danger, avalanche danger level and their
contributing factors; presented at EAWS General Assembly, Davos, Switzerland,
2021, EAWS working group Matrix and Scale (working group members: Müller,
K., Bellido, G., Bertrando, L., Feistl, T., Mitterer, C., Palmgren, P.,
Sofia, S., and Techel, F.). presented at: EAWS General Assembly, Davos,
Switzerland, June 2021, 2021. a, b, c
Efron, B.: Bootstrap methods: another look at the jackknife, Ann.
Stat., 7, 1–26,
1979. a
Engeset, R. V., Pfuhl, G., Landrø, M., Mannberg, A., and Hetland, A.: Communicating public avalanche warnings – what works?, Nat. Hazards Earth Syst. Sci., 18, 2537–2559, https://doi.org/10.5194/nhess-18-2537-2018, 2018. a
Floyer, J., Klassen, K., Horton, S., and Haegeli, P.: Looking to the 20's:
computer-assisted avalanche forecasting in Canada, in: Proceedings ISSW 2016.
International Snow Science Workshop, 2–7 October 2016, Breckenridge, Co.,
1245–1249, 2016. a
Goffin, R. and Olson, J.: Is it all relative? Comparative judgments and the
possible improvement of self-ratings and ratings of others, Perspect.
Psychol. Sci., 6, 48–60, 2011. a
Hollander, M. and Wolfe, D.: Nonparametric Statistical Methods, New York, John
Wiley and Sons, 528 p., 1973. a
Hutter, V., Techel, F., and Purves, R. S.: How is avalanche danger described in textual descriptions in avalanche forecasts in Switzerland? Consistency between forecasters and avalanche danger, Nat. Hazards Earth Syst. Sci., 21, 3879–3897, https://doi.org/10.5194/nhess-21-3879-2021, 2021. a, b, c, d
Kuter, K.: Essential probability theory for data science (DSCI 500B), Saint
Mary's College, https://stats.libretexts.org/Courses/Saint_Mary's_College_Notre_Dame/DSCI_500B_Essential_Probability_Theory_for_Data_Science_(Kuter) (last access: 8 February 2022), 2020. a
LaChapelle, E.: The fundamental process in conventional avalanche
forecasting, J. Glaciol., 26, 75–84,
https://doi.org/10.3189/S0022143000010601, 1980. a, b
Lehning, M., Bartelt, P., Brown, B., Russi, T., Stöckli, U., and Zimmerli,
M.: Snowpack model calculations for avalanche warning based upon a new
network of weather and snow stations, Cold Reg. Sci. Technol., 30, 145–157, https://doi.org/10.1016/S0165-232X(99)00022-1, 1999. a
Logan, S. and Greene, E.: Patterns in avalanche events and regional scale
avalanche forecasts in Colorado, USA, in: Proceedings ISSW 2018.
International Snow Science Workshop, 7–12 October 2018, Innsbruck, Austria,
1059–1062, 2018. a
MacGregor, D.: Principles of forecasting: a handbook for researchers and
practitioners, vol. 30 of International Series in Operations Research &
Management Science, chap. Decomposition for judgmental forecasting and
estimation, 107–123, Springer, Boston, MA,
https://doi.org/10.1007/978-0-306-47630-3_6, 2001. a
McClung, D.: The elements of applied avalanche forecasting, part I: The human
issues, Nat. Hazard., 26, 111–129, https://doi.org/10.1023/A:1015665432221, 2002. a
McClung, D. and Schaerer, P.: The Avalanche Handbook, The Mountaineers,
Seattle, WA., 3rd Edn., 2006. a
MeteoSwiss: COSMO forecasting system,
https://www.meteoswiss.admin.ch/home/measurement-and-forecasting-systems/warning-and-forecasting-systems/cosmo-forecasting-system.html,
last access: 6 January 2022. a
Miller, G.: The magical number seven, plus or minus two: Some limits on our
capacity for processing information, Psychol. Rev., 63, 81–97,
https://doi.org/10.1037/h0043158, 1956. a
Morin, S., Horton, S., Techel, F., Bavay, M., Coléou, C., Fierz, C., Gobiet,
A., Hagenmuller, P., Lafaysse, M., Ližar, M., Mitterer, C., Monti, F.,
Müller, K., Olefs, M., Snook, J. S., van Herwijnen, A., and Vionnet, V.:
Application of physical snowpack models in support of operational avalanche
hazard forecasting: A status report on current implementations and prospects
for the future, Cold Reg. Sci. Technol., 170, p. 102910,
https://doi.org/10.1016/j.coldregions.2019.102910, 2019. a, b
Murphy, A. H.: What is a good forecast? An essay on the nature of goodness in
weather forecasting, Weather Forecast., 8, 281–293,
https://doi.org/10.1175/1520-0434(1993)008<0281:WIAGFA>2.0.CO;2, 1993. a
Newcombe, R. G.: Interval estimation for the difference between independent
proportions: comparison of eleven methods, Stat. Med., 8,
873–890,
https://doi.org/10.1002/(sici)1097-0258(19980430)17:8<873::aid-sim779>3.0.co;2-i, 1998. a
Pérez-Guillén, C., Techel, F., Hendrick, M., Volpi, M., van Herwijnen, A., Olevski, T., Obozinski, G., Pérez-Cruz, F., and Schweizer, J.: Data-driven automated predictions of the avalanche danger level for dry-snow conditions in Switzerland, Nat. Hazards Earth Syst. Sci. Discuss. [preprint], https://doi.org/10.5194/nhess-2021-341, in review, 2021. a, b, c, d, e
R Core Team: R: A Language and Environment for Statistical Computing, R
Foundation for Statistical Computing, Vienna, Austria, https://www.R-project.org/ (last access: 2 June 2022), 2020. a
Ramachandran, K. M. and Tsokos, C. P.: Mathematical Statistics with
Applications in R, Chap. 13 – Empirical methods, 531–568,
Academic Press, 3rd edn., https://doi.org/10.1016/B978-0-12-817815-7.00013-0, 2021. a, b
Ridout, M., Demetrio, C., and Hinde, J.: Models for count data with many zeros,
in: International Biometric Conference, Cape Town, Dec 1998, p. 13,
https://www.semanticscholar.org/paper/Models-for-count-data-with-many-zeros-Ridout-Dem%C3%A9trio/6a99f29a84a90284dabc3396296ab6cea806aa37 (last access: 2 June 2022),
1998. a
Schmudlach, G.: Skitourenguru, https://www.skitourenguru.ch,
last access: 6 January 2022. a
Schmudlach, G. and Köhler, J.: Automated avalanche risk rating of backcountry
ski routes, in: Proceedings ISSW 2016. International Snow Science Workshop,
2–7 October 2016, Breckenridge, Co., 2016, pp. 450–456, 2016. a
Schmudlach, G., Harvey, S., and Dürr, L.: How do experts interpret avalanche
terrain from a map?, in: Proceedings ISSW 2018. International Snow Science
Workshop, 7–12 Oct 2018, Innsbruck, Austria, 1674–1680, 2018. a
Schweizer, J.: The Rutschblock test – procedure and application in
Switzerland, The Avalanche Review, 20, 14–15, 2002. a
Schweizer, J. and Jamieson, B.: Snowpack tests for assessing snow-slope
instability, Ann. Glaciol., 51, 187–194,
https://doi.org/10.3189/172756410791386652, 2010. a, b
Schweizer, J., Kronholm, K., and Wiesinger, T.: Verification of regional
snowpack stability and avalanche danger, Cold Reg. Sci. Technol., 37,
277–288, https://doi.org/10.1016/S0165-232X(03)00070-3, 2003. a
Schweizer, J., Mitterer, C., Techel, F., Stoffel, A., and Reuter, B.: On the relation between avalanche occurrence and avalanche danger level, The Cryosphere, 14, 737–750, https://doi.org/10.5194/tc-14-737-2020, 2020. a
Schweizer, J., Mitterer, C., Reuter, B., and Techel, F.: Avalanche danger level characteristics from field observations of snow instability, The Cryosphere, 15, 3293–3315, https://doi.org/10.5194/tc-15-3293-2021, 2021. a
Simenhois, R. and Birkeland, K.: The Extended Column Test: Test effectiveness,
spatial variability, and comparison with the Propagation Saw Test, Cold
Reg. Sci. Technol., 59, 210–216,
https://doi.org/10.1016/j.coldregions.2009.04.001, 2009. a, b
SLF: Description of automated stations,
https://www.slf.ch/en/avalanche-bulletin-and-snow-situation/measured-values/description-of-automated-stations.html,
last access: 6 January 2022. a
St. Clair, A., Finn, H., and Hageli, P.: Where the rubber of the RISP model
meets the road: Contextualizing risk information seeking and processing with
an avalanche bulletin user typology, Int. J. Disaster Risk
Red., 66, 102626, https://doi.org/10.1016/j.ijdrr.2021.102626, 2021. a
Statham, G., Holeczi, S., and Shandro, B.: Consistency and accuracy of public
avalanche forecasts in Western Canada, in: Proceedings ISSW 2018,
International Snow Science Workshop, 7–12 October 2018, Innsbruck, Austria,
1491–1496, 2018b. a
Techel, F. and Schweizer, J.: On using local avalanche danger level estimates
for regional forecast verification, Cold Reg. Sci. Technol., 144,
52–62, https://doi.org/10.1016/j.coldregions.2017.07.012, 2017. a, b
Techel, F., Winkler, K., Walcher, M., van Herwijnen, A., and Schweizer, J.: On snow stability interpretation of extended column test results, Nat. Hazards Earth Syst. Sci., 20, 1941–1953, https://doi.org/10.5194/nhess-20-1941-2020, 2020c.
a, b, c
Techel, F.: Observational data: avalanche observations, danger signs and stability test results, Switzerland (2016/2017 to 2020/2021), https://doi.org/10.16904/envidat.329, 2022. a
Walcher, M., Mitterer, C., and Lanzanasto, N.: A concept of harmonizing
regional avalanche forecasting, in: Proceedings ISSW 2018, International Snow
Science Workshop, 7–12 October 2018, Innsbruck, Austria, 1166–1171, 2018. a
Wilks, D.: Statistical methods in the atmospheric sciences, vol. 100 of International Geophysics Series, Academic Press, San Diego CA, USA, 3rd
edn., 2011. a
Winkler, K. and Schweizer, J.: Comparison of snow stability tests: Extended
Column Test, Rutschblock test and Compression Test, Cold Reg. Sci.
Technol., 59, 217–226, https://doi.org/10.1016/j.coldregions.2009.05.003, 2009. a, b
Short summary
Can the resolution of forecasts of avalanche danger be increased by using a combination of absolute and comparative judgments? Using 5 years of Swiss avalanche forecasts, we show that, on average, sub-levels assigned to a danger level reflect the expected increase in the number of locations with poor snow stability and in the number and size of avalanches with increasing forecast sub-level.
Can the resolution of forecasts of avalanche danger be increased by using a combination of...
Altmetrics
Final-revised paper
Preprint