Landslide inventories for climate impacts research in the European Alps

Abstract

Landslides present a geomorphological hazard in Alpine regions, threatening life, infrastructure and property. Here we present the development of a new regional landslide inventory (RI) for the European Alps. This database provides a substantial temporal and spatial picture of landsliding in the Alps, with particular focus on the Swiss and French Alps. We use segmented models to evaluate recording bias in the temporal record. We use scaling relationships to calculate landslide area based on a given volume for similar types of landslide; with the result of this being that 9.5% of the landslides recorded in the RI now have area data recorded. These landslide area data are then used to examine the log-linear trend, which exists between landslide area and frequency in inventories. We show that this relationship is present for this historical dataset; however, none of the individual databases, nor a unification of these, contain a complete record with the small and larger landslides being recorded more consistently. The use of segmented models on the temporal distribution of landslides in the RI shows that the post-1970 portion of the database is more reliable, highlighted through an improved power-law relationship, although the frequency of medium sized landslides is still underestimated. We show that creating a unified database (RI) can increase the reliability of datasets and consistency in recording for the use by researchers for attribution and detection studies.