Are heavy-rainfall events a major trigger of associated natural hazards along the German rail network?

Abstract

Heavy-rainfall events and associated natural hazards pose a major threat to rail transport and infrastructure. In this study, the correlation between heavy-rainfall events and three associated natural hazards was investigated using geographic information system (GIS) analyses and random-effects logistic models. The spatiotemporal linkage of a damage database from Deutsche Bahn (DB) Netz AG and the catalogue of radar-based heavy-rainfall events (CatRaRE) from the German Weather Service (DWD) revealed that almost every part of the German rail network was affected by at least one heavy-rainfall event between 2011 and 2021, with 23 % of the flood events, 14 % of the gravitational mass movements, and 2 % of the tree fall events occurring after a heavy-rainfall event. The random-effects logistic regression models showed that a heavy-rainfall event significantly increases the odds of occurrence of a flood (tree fall) by a factor of 22.7 (3.62). We find no evidence of an effect on gravitational mass movements. The heavy-rainfall index and the 21 d antecedent precipitation index were determined to be the characteristics of the heavy-rainfall events with the strongest impact on all three natural hazards. The results underline the importance of gaining more precise knowledge about the impact of climate triggers on natural hazard-related disturbances in order to make rail transport more resilient.