Debris-flow chronology in Calimani Mountains (Eastern Carpathians, Romania) reconstructed with dendrogeomorphic methods

Debris flows (DFs) occur in the high areas of the Carpathians, being efficient sediment transfer processes from slopes to river channels. They often damage transportation infrastructure and forested areas and threaten rec- reational activities. Gathering knowledge about the past DF activity is crucial to minimize the negative impact of present-day hydrogeomorphic activity. Understanding past DFs behaviour helps to predict the future trends of this potential natural hazard in the context of documented climate change. In this context, information on long-term DF activity needs to be known. In the Carpathians, as in most mountain areas worldwide, the lack of historical records of past hydrogeomorphic process activity in terms of temporal frequency and spatial extent hampers the possibility of having a good knowledge of the past DF activity. Reconstructing methods using various biomarkers, e.g., tree rings, may be applied to document past DF activity with annual resolution. This study aims to reconstruct past DF activity along an active track in the central Calimani Mountains using dendrogeomorphic methods. Results of the dendrogeomorphic study that investigated the DF track reveal a minimum chronology of 14 events reconstructed spanning the 1930-2019 period, which corresponds with an average return period of 6.3 years.