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| Titel |
A rapid method to identify the potential of debris flow development induced by rainfall in catchments of the Wenchuan earthquake area |
| VerfasserIn |
Wei Zhou, Chuan Tang, Th. W. J. van Asch, Ming Chang |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250086452
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| Publikation (Nr.) |
 EGU/EGU2014-321.pdf |
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| Zusammenfassung |
| E-mail: chouvw@gmail.com; chouvw@163.com
Abstract: In many mountainous areas, the limited space in the valley floors has created a
need to construct the temporary settlements in zones potentially exposed to debris
flow hazards after a strong earthquake. In these zones, a rapid identification of
catchments with a high hazard level for debris flows is then necessary, to provide
information for future risk management. This paper presents an empirical model to
identify debris flow prone catchments at a regional scale. Sixty-nine debris flow
catchments in the Wenchuan earthquake area were selected and investigated using
high-resolution aerial photography to estimate the area of loose materials in the
debris-flow catchments The statistical results show that debris flow prone catchments,
have areas lower than 5 km2, and channel gradients which vary between 364 and
1192oand an internal relief lower than 2 km. But the level of debris flow hazard in these
catchments is more closely related to the area of loose materials than basin relief and
channel gradient. So basin area and area of loose materials were selected as the key
factor to establish an applicable identification model. A mathematical model was
constructed to estimate the thresholds of areas of loose materials for debris-flow prone
catchments. The validation showed that the established model was suitable and
met the requirements for identification of potential debris flows in the Wenchuan
earthquake area. The results of the study will help the local government to select
safe sites for rehabilitation and relocation in the future and can also be used as an
important basis for debris-flow risk management. The approach may be applied to other
earthquake areas, when adapting the threshold parameters according to new local
conditions.
Key words: Wenchuan earthquake; statistical model; debris flow thresholds |
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