Spatial Statistical Modeling of Rockfall Hazard in a Mountainous Road in Cantabria (Spain)

Abstract

Rockfall events are one of the most frequent types of mass wasting in mountainous areas, causing service and traffic disruption, as well as infrastructure and human damage. Hence, having accurate tools to model these hazards becomes crucial to prevent fatalities, especially in a context of Climate Change whereby the effects of these phenomena might be exacerbated. Under this premise, this research concerned the development of a framework for assessing rockfall hazard in mountainous areas. First, a set of factors expected to favour rockfalls were processed and aggregated using spatial analysis tools, yielding a series of hazard maps with which to fit observed data through statistical modelling. The validation process was undertaken with the support of a database containing the number of rocks removed from a mountainous road section located in Cantabria, northern Spain. The results achieved, which demonstrated the accuracy of the proposed approach to reproduce rockfall hazard using frequency data, highlighted the primary role played by factors such as slope, runoff threshold and precipitation to explain the occurrence of these events. The effects of Climate Change were considerably influenced by the fluctuations in the projections of precipitation, which limited the variations in the spatial distribution and magnitude of rockfall hazard.