气候变化领域集成服务门户(CCPortal): The temporally varying roles of rainfall; snowmelt and soil moisture for debris flow initiation in a snow-dominated system

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DOI	10.5194/hess-22-3493-2018
	The temporally varying roles of rainfall; snowmelt and soil moisture for debris flow initiation in a snow-dominated system
	Mostbauer K.; Kaitna R.; Prenner D.; Hrachowitz M.
发表日期	2018
ISSN	1027-5606
起始页码	3493
结束页码	3513
卷号	22 期号:6
英文摘要	Debris flows represent frequent hazards in mountain regions. Though significant effort has been made to predict such events, the trigger conditions as well as the hydrologic disposition of a watershed at the time of debris flow occurrence are not well understood. Traditional intensity-duration threshold techniques to establish trigger conditions generally do not account for distinct influences of rainfall, snowmelt, and antecedent moisture. To improve our knowledge on the connection between debris flow initiation and the hydrologic system at a regional scale, this study explores the use of a semi-distributed conceptual rainfall-runoff model, linking different system variables such as soil moisture, snowmelt, or runoff with documented debris flow events in the inner Pitztal watershed, Austria. The model was run on a daily basis between 1953 and 2012. Analysing a range of modelled system state and flux variables at days on which debris flows occurred, three distinct dominant trigger mechanisms could be clearly identified. While the results suggest that for 68% (17 out of 25) of the observed debris flow events during the study period high-intensity rainfall was the dominant trigger, snowmelt was identified as the dominant trigger for 24% (6 out of 25) of the observed debris flow events. In addition, 8% (2 out of 25) of the debris flow events could be attributed to the combined effects of low-intensity, long-lasting rainfall and transient storage of this water, causing elevated antecedent soil moisture conditions. The results also suggest a relatively clear temporal separation between the distinct trigger mechanisms, with high-intensity rainfall as a trigger being limited to mid- A nd late summer. The dominant trigger in late spring/early summer is snowmelt. Based on the discrimination between different modelled system states and fluxes and, more specifically, their temporally varying importance relative to each other, this exploratory study demonstrates that already the use of a relatively simple hydrological model can prove useful to gain some more insight into the importance of distinct debris flow trigger mechanisms. This highlights in particular the relevance of snowmelt contributions and the switch between mechanisms during early to mid-summer in snow-dominated systems. © 2018 Author(s).
语种	英语
scopus关键词	Debris; Runoff; Snow; Snow melting systems; Soil moisture; Watersheds; Antecedent moisture; Antecedent soil moisture; Debris flow occurrences; High intensity rainfall; Hydrological modeling; Rainfall-runoff modeling; Temporal separation; Threshold techniques; Rain; debris flow; flux measurement; hydrological modeling; mountain region; precipitation intensity; rainfall; rainfall-runoff modeling; snow; snowmelt; soil moisture; temporal variation; trigger mechanism; watershed; Austria
来源期刊	Hydrology and Earth System Sciences
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/159991
作者单位	Mostbauer, K., Institute of Mountain Risk Engineering, University of Natural Resources and Life Sciences, Vienna, Austria; Kaitna, R., Institute of Mountain Risk Engineering, University of Natural Resources and Life Sciences, Vienna, Austria; Prenner, D., Institute of Mountain Risk Engineering, University of Natural Resources and Life Sciences, Vienna, Austria; Hrachowitz, M., Water Resources Section, Faculty of Civil Engineering and Geosciences, Delft University of Technology, Delft, Netherlands
推荐引用方式 GB/T 7714	Mostbauer K.,Kaitna R.,Prenner D.,et al. The temporally varying roles of rainfall; snowmelt and soil moisture for debris flow initiation in a snow-dominated system[J],2018,22(6).
APA	Mostbauer K.,Kaitna R.,Prenner D.,&Hrachowitz M..(2018).The temporally varying roles of rainfall; snowmelt and soil moisture for debris flow initiation in a snow-dominated system.Hydrology and Earth System Sciences,22(6).
MLA	Mostbauer K.,et al."The temporally varying roles of rainfall; snowmelt and soil moisture for debris flow initiation in a snow-dominated system".Hydrology and Earth System Sciences 22.6(2018).