Abstract

Hydro-meteorological trigger conditions, which are expected to alter in a future climate, have a significant impact on debris flow activity. In order to evaluate changes in the frequency of critical trigger conditions for various trigger typeslong-lasting rainfall, short-duration storm, snow-melt, and rain-on-snow-in six regions of the Austrian Alps, we connect a regional hydro-meteorological susceptibility model for debris flows with climate projections until 2100. When the number of days necessary for debris-flow initiation is averaged across all regions, there are few annual changes, but there are distinct changes when hydro-meteorological trigger types and the study region are separated. At the monthly and seasonal scales, changes become more apparent, with a general pattern of critical debris-flow trigger conditions earlier in the year. The findings of this study can be used as a foundation for future risk management adaptation strategies.