im PublikationsserverTitelangaben
Rom, Jakob ; Haas, Florian
; Heckmann, Tobias ; Betz-Nutz, Sarah ; Altmann, Moritz ; Fleischer, Fabian ; Becht, Michael:
Slope-type debris flow record since the end of the Little Ice Age using aerial photographs and lichenometric methods in the Grastal and Zwieselbachtal, Austria.
2022
Veranstaltung: International Mountain Conference (IMC), 11.-15. Sep. 2022, Innsbruck, Austria.
(Veranstaltungsbeitrag: Kongress/Konferenz/Symposium/Tagung, Präsentation)
Kurzfassung/Abstract
Debris flows play a big role in the morphodynamic systems of high
mountain regions as well as in the interaction with other geosystems
(e.g. biosphere). To get a better understanding of the future
development of debris flow dynamic, it is crucial to gain a good
understanding of the development of the dynamic in the past. However,
it is difficult to obtain a sufficient debris flow record in high mountain
areas, as for example historical text chronicles do often not provide
detailed information for high altitude regions above settlement places
and dendromorphological studies are only possible in forested areas.
Within this study, we establish a record of slope-type debris flows since
the end of the Little Ice Age for the Grastal and the Zwieselbachtal, two
side valleys of the Horlachtal, which is located within the Stubai Alps in
Tyrol, Austria. Here, aerial and terrestrial photographs are limited to the
period since 1947. Therefore, a detailed debris flow record for the
timespan between 1947 and 2020 could be established based on a
multitemporal analysis of available aerial photographs of twelve different
time steps. For the timeframe between the end of the Little Ice Age and
the first area-wide aerial photographs in 1947, we used lichenometric
methods to date old debris flow deposits. Lichenometry is based on the
even and consistent growth rate of the thalli of the lichen Rhizocarpon
geographicum, which is a widespread species within the High Alps.
During an extended field survey in summer 2021, we measured the
diameter of lichen thalli at 105 different sites in the study areas. With
the help of the collected data, we established a calibration curve using
the thalli of 52 lichen sites from known historical glacier extents as well
as debris flow deposits, which could be dated by the comparison of aerial
photographs. Using this calibration curve, we were able to date 53
different debris flow deposits in the study area using the
Five-Largest-Lichen approach and therefore extent the debris flow
record to the period prior to 1947.
Forschungsprojekte
Research Unit SEHAG - Sensitivity of high Alpine geosystems to climate change since 1850 (SEHAG)
Weitere Angaben
| Publikationsform: | Veranstaltungsbeitrag (unveröffentlicht): Kongress/Konferenz/Symposium/Tagung, Präsentation |
|---|---|
| Sprache des Eintrags: | Englisch |
| Institutionen der Universität: | Mathematisch-Geographische Fakultät > Geographie > Lehrstuhl für Physische Geographie |
| Titel an der KU entstanden: | Ja |
| KU.edoc-ID: | 30861 |
Letzte Änderung: 19. Okt 2022 13:59
URL zu dieser Anzeige: https://edoc.ku.de/id/eprint/30861/
