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"Natural conditions that explain the triggering of snow avalanches are becoming better-known, but our understanding of how socio-environmental changes can influence the occurrence of damaging avalanches is still limited.This study analyses the evolution of snow avalanche damage in the Asturian Massif (NW Spain) between 1800 and 2015, paying special attention to changes in land-use and land-cover patterns. A damage index has been performed using historical sources, photointerpretation and fieldwork-based data, which were introduced in a GIS and processed by means of statistical analysis. Mapping allowed connecting spatiotemporal variations of damage and changes in human-environment interactions. The total number of victims was 342 (192 dead and 150 injured).Results show stability in the number of avalanches during the study period, but a progressive decrease in the damage per avalanche. Changes in land use explain the evolution of damage and its spatial/temporal behaviour. The role played by vegetation cover is at the root of this process: damage was the highest during the late 19th and early 20th centuries, when a massive deforestation process affected the protective forest.This deforestation was the result of demographic growth and intensive grazing, disentailment laws and emerging coal mining. Since the mid-20th century, the transformation of a traditional land-management system based on overexploitation into a system based on land marginalization and reforestation, together with the decline of deforestation due to industrial and legal causes, resulted in the decrease of avalanches that affected settlements (mostly those released below the potential timberline). "
"The deceleration of a more intense deforestation, in parallel to a more successful process of natural vegetation recovery, favoured by the existence of deeper soils, resulted in a sharper and earlier decline of damage in the Western sector of the Asturian Massif. Since the 1960s, the damage per avalanche started an evident decrease in the whole territory, but the Eastern sector gained relative importance by absorbing the majority of damage caused by avalanches related to recreation and sports in mountain environments, and the relative importance of the Central sector remained stable since it contained most of the infrastructures.The effects of the revegetation process are currently being highly discussed by the scientific community.The results of this study highlight one of its possible positive consequences: the reduction of avalanche damage. Nevertheless, taking into account other effects of this process (which may increase the potential for fires and has been widely considered negative from the cultural point of view), planning is imperative. Plans must be carried out to preserve protective forests, but these actions can be combined with controlled grazing in forests assessing potential release areas, so we can get all the advantages of those clearing actions without sacrificing the existence of the protective effects of the forest against snow avalanches."
The Asturian Massif makes up the western area of the Cantabrian Mountains, located in the NW of the Iberian Peninsula.