Risk Information Sources for Snow Disaster Risk Preparedness in Scotland

Heavy snow disruptions are common and costly occurrences in the UK, including Scotland. Yet, heavy snow remains an underresearched aspect of disaster risks in Scotland. This study critically examined the 2018 heavy snow event in Scotland referred to as the “Beast from the East” (BfE) in order to explore the different sources of information used by the public in preparation for and response to heavy snow emergencies. Our study also examined the effectiveness of BfE risk communication between authorities and the public and sought to determine if there is a relationship between risk information received and the intention to mitigate risk. Data were collected through a semistructured survey from (n = 180) residents of the Annandale and Eskdale region of Dumfries and Galloway, Scotland. Our analysis shows that public authority information sources were the most sought-after information sources, followed by online and web sources. We found statistically significant differences between groups (such as age, gender, and mobility/disability) in terms of using risk information sources. Further analysis shows that the relationship between information received and the intention to mitigate risks is not linear but influenced by intervening variables such as work pressures, financial commitment, and stakeholders’ expectations. We argue that where full adherence to official risk advice is required, policymakers should carefully consider issues around these three factors.

Reliability of Noninvasive Sonic Tomography for the Detection of Internal Defects in Old, Large Trees of Abies holophylla Maxim

Internal decay and cavities in wood are known to reduce the structural functionality of trees. Such damage may lead to detrimental effects not only on the wood, but also on humans. This is especially the case with old, large trees that are more vulnerable to heavy snow and strong wind. Thus, preventative management (e.g., detecting internal wood defects) is essential. The present study investigated the reliability of noninvasive measurements using sonic tomography (SoT) to detect internal defects in Abies holophylla Maxim. trees and compared the results with measurements using the invasive method of resistance microdrilling (RM). The tomograms were visually compared with tree cross-section images. The results of SoT and RM showed no significant differences, while the explanatory power, as determined by a regression analysis, were considerably high at 67% with a positive correlation between the two methods. In comparison to the cross-section images, the tomograms were found to reflect the size and position of internal decay, although the detected size tended to be larger than the actual decay area. Our findings indicate SoT as a promising noninvasive technique for detecting internal defects in A. holophylla trees.

Characteristics of mountain glaciers in the northern Japanese Alps

In 2012, three perennial snow patches in the northern Japanese Alps were determined to be very small glaciers (VSGs: < 0.5 km2). These were soon followed by four more nearby. However, it had not been determined how such glaciers could be maintained in such a warm climate. In this study, we calculate annual and seasonal mass balances of five of these VSGs, covering 2015–2019 for four of them (2017–2019 for the fifth) using multi-period digital surface models (DSMs) based on structure from motion–multi-view stereo (SfM–MVS) technology and images taken from a small airplane. The results indicate that, due to mass acquired from avalanches, these VSGs are maintained by acquiring a winter balance that is more than double that from the snowfall amount, thereby exceeding the summer balance. Therefore, we classify them as topographically controlled VSGs. We find almost no annual fluctuation in their summer balance; however, their winter balance, and annual balance, have large annual fluctuations. The annual balance, which mainly depends on the winter balance, showed accumulation throughout each glacier during heavy snow years and ablation throughout each glacier during light snow years. This characteristic differs from the upper accumulation area and lower ablation area that exists on most glaciers. These VSGs had negative annual balance gradients, which suggests that they did not have an equilibrium line during the observation period. Moreover, comparing to other glaciers worldwide, we find the mass balance amplitude of glaciers in the northern Japanese Alps to be the highest measured to date.

A Climatological Study of National Weat her Service Watches, Warnings, and Advisories and Landfalling Atmospheric Rivers in the Western U.S. 2006–2018

Atmospheric rivers (ARs) are synoptic-scale phenomena associated with long, narrow corridors of enhanced low-level water vapor transport. Landfalling ARs may produce numerous beneficial (e.g. drought amelioration and watershed recharge) and hazardous (e.g. flash flooding and heavy snow) impacts that may require the National Weather Service (NWS) to issue watches, warnings, and advisories (WWAs) for hazardous weather. Prior research on WWAs and ARs in California found that 50–70% of days with flood-related and 60–80% of days with winter weather-related WWAs occurred on days with landfalling ARs in California. The present study further investigates this relationship for landfalling ARs and WWAs during the cool seasons of 2006–2018 across the entire western U.S. and considers additional dimensions of AR intensity and duration. Across the western U.S., regional maxima of 70–90% of days with WWAs issued for any hazard type were associated with landfalling ARs. In the Pacific Northwest and Central regions, flood-related and wind-related WWAs were also more frequently associated with more intense and longer duration ARs. While a large majority of days with WWAs were associated with landfalling ARs, not all landfalling ARs were necessarily associated with WWAs (i.e., not all ARs are hazardous). For example, regional maxima of only 50–70% of AR days were associated with WWAs issued for any hazard type. However, as landfalling AR intensity and duration increased, the association with a WWA and the “hazard footprint” of WWAs increased quasi-exponentially across the western U.S.

Mapping the probability of forest snow disturbances in Finland

The changing forest disturbance regimes emphasize the need for improved damage risk information. In this study, our aim was to improve the current understanding of snow damage risks by assessing the importance of abiotic factors, particularly the modelled snow load on tree crowns, versus forest properties in predicting the probability of snow damage, producing a snow damage probability map for Finland and test its performance, and comparing the results for winters with typical snow load conditions and a winter with exceptionally heavy snow loads. To do this, we used damage observations from the Finnish national forest inventory (NFI) to create a statistical snow damage occurrence model, spatial data layers from different sources to use the model to predict the damage probability for the whole country in 16 × 16 m resolution. Snow damage reports in forest use declarations were used for testing the final map. Our results showed that best results were obtained when both abiotic and forest variables were included in the model. However, in the case of the high snow load winter, the model with only abiotic predictors performed nearly as well as the full model. The statistical models were also able to identify the snow damage stands more accurately for the heavy snow load winter. The two tested statistical modelling methods. The snow damage model and the derived wall-to-wall probability map were able to discriminate between the damage and no-damage cases on a good level. The model and the damage probability mapping approach identifies the drivers of and susceptibility factors to snow damage across forest landscapes. Moreover, it can be used to estimate the concurrent and future snow damage risks in forests, which informs practical forestry and decision-making regarding climate change mitigation and adaptation of forestry.

Snow and Avalanches in a Climate Warming Context

We first show why current climate forecasting techniques, based on continuous extrapolations, are unreliable in the case of complex arrangements of interacting entities like the atmosphere–ocean system. By contrast, according to the well-established theory of dynamical systems, the observed present increase of fluctuations (as heat waves, droughts, tornadoes, forest fires) is a warning signal for an impending discontinuous climate tipping. A comparison with paleoclimatic events suggests that the atmospheric temperature would be likely to increase in this case by 6–9 °C in the next few years. In the transient period, the succession of heavy snow-falls and thawing episodes would favor spontaneous full-depth avalanches with larger run-out distances. After tipping into a new equilibrium, significantly warmer temperatures would shift snow-covered areas towards higher altitudes, probably by more than 1000 m, resulting in closure of a number of ski resorts. Glacier retreat and permafrost thawing would also enhance both ice and rock-fall frequency.