Assessing the interaction between mountain forests and snow avalanches at Nevados de Chillán, Chile and its implications for ecosystem-based disaster risk reduction

Abstract

Abstract. Gravitational natural hazards such as snow avalanches, rockfalls, shallow landslides and volcanic activity represent a risk to mountain communities around the world. In particular, where documentary records about these processes are rare, decisions on risk management and land-use planning have to be based on a variety of other sources including vegetation, tree-ring data and natural hazard process models. We used a combination of these methods in order to evaluate dynamics of natural hazards with a focus on snow avalanches at Valle Las Trancas, in the Biobío region in Chile. Along this valley, natural hazards threaten not only the local human population, but also the numerous tourists attracted by outdoor recreational activities. Given the regional scarcity of documentary records, tree-ring methods were applied in order to reconstruct the local history of snow avalanches and debris flow events, which are the most important weather-related processes at respective tracks. A recent version of the model Rapid Mass MovementS (RAMMS), which includes influences of forest structure, was used to calculate different avalanche parameters such as runout distances and maximum pressures, taking into consideration the presence or absence of forest along the tracks as well as different modeled return periods. Our results show that local Nothofagus broadleaf forests contribute to a reduction of avalanche runout distances as well as impact pressure on present infrastructure, thus constituting a valuable ecosystem disaster risk reduction measure that can substitute or complement other traditional measures such as snow sheds.

Spatial Modeling of Snow Avalanche Using Machine Learning Models and Geo-Environmental Factors: Comparison of Effectiveness in Two Mountain Regions

“…However, these methods are expert opinion-based and subjective. Some researchers have used numerical methods and dynamic models to analyze the snow avalanche hazard [18][19][20][21], however a lot of uncertainty is involved in all the modeling parameters when applying to large regions at smaller scales. Other research methods are based upon remote-sensing techniques [14,[22][23][24][25].…”

The influence of abiotic and biotic disturbances on the protective effect of alpine forests against avalanches and rockfalls

“…Smaller avalanches that flow through forest can break, uproot and overturn trees, while large avalanches can even destroy large tracts of mountain for-est (Takeuchi et al, 2011;Feistl et al, 2014;Casteller et al, 2018). The damage potential of avalanches that have larger amounts of tree debris (e.g.…”

Platform Dedicated to Nature-Based Solutions for Risk Reduction and Environmental Issues in Hilly and Mountainous Lands

“…Thus, NBSs concerning natural risks and ecosystem services in hilly and mountainous areas (landslides, floods…) have been extracted. In addition, a literature review has been done in order to find others NBS cases study not referenced in platforms and databases [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34].…”