Fatal non-seismic rockfalls in Spain

Abstract Rockfalls are the slope instability processes that cause the greatest number of victims in Spain, as well as considerable economic losses. This paper quantifies the impact of fatal rockfalls obtained from the documentary collection, mainly written press. We compiled 1,118 events that occurred between 1803 and 2021 and caused casualties (1,550 deaths and around 2,184 injuries). From this set, we analyzed the seasonal distribution and multiannual evolution of 1,018 rockfalls events for the period 1872–2021 (150 years) in which the daily written press was available. The inventoried cases were divided according to the context in which they occurred: dwellings and villages, quarries and excavations, railways, roads and outdoor activities (mountain trails and coastal areas). Diverging trends are observed. While the consequences and risk have decreased as stabilization and prevention actions accumulate around threatened dwellings, quarries and railroads, the number of fatal incidents has increased on roads and in natural spaces. This is due to the increase in roads and traffic, and especially, the greater presence of people in the natural environment (increased exposure). We present a first quantitative estimate of the investments made by administrations to stabilize artificial cuts and natural cliffs in order to reduce the risk of rockfalls.