EGU2016-11515.pdf

Historical flood analysis of the Eistlenbach and Farnigraben torrents in the Hasli Valley (Bernese Alps) was conducted using sedimentary records, historical maps, and remote sensing. The study aimed to reconstruct historical floods and changes in the geomorphology of the distal areas of the torrents. Results show distinct flood layers related to debris flow and flood events over the last 700 years, with peaks of Log (Zr/Ti) and Ca/Ti correlating with coarse-grained flood layers. Spatial analysis identified geomorphological dynamics and changes in the alluvial fan, including channel shifts and land cover changes. The study provides information on landform and land cover changes, and may help estimate the recurrence interval of tipping points of the oscillating shifts of the Eistlenbach torrent, informing hydrological risk assessment in the area.