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| Titel |
Deep seated landslides along the Meilungshan fault in Laonung River Waterdhed, southern Taiwan |
| VerfasserIn |
Dia-Jie Ho, Ching-Weei Lin, Chih-Ming Tseng |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250075801
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| Zusammenfassung |
| Landslides in Taiwan represent one of most relevant natural hazards for the society. In
particular, the large scaled deep-seated landslides deserve attention, because they can be
reactivated during intense events and can evolve into destructive failures. For example, one
deep seated landslide, the Hsiaolin landslide, with an area of about 250 ha, buried
the entire village of Hsiaolin in Kaohsiung County causing 397 causalities, the
disappearance of 53 others, and buried over 100 houses during the Typhoon Morakot in
2009.
The Laonung River watershed which covered 1367 km2 is selected as our study area. The
study area is mainly compose of Miocene slate and sedimentary rocks that are separated by a
major fault, the Meilungshan fault. The Meilungshan fault is part of the boundary fault
separating the Central Range and Western Foothill in southern Taiwan. The fault is a west
verging, high angle NNE trending thrust. Some outcrops show the fault zone is over one
hundred and fifty meters thick, and it is mainly composed of gouge and fault breccias of
slate.
Within the study area, 361 sites with an area greater than 10 ha and with sliding
topographic features of deep seated landslide such as crown main escarpment, down slope
scarp, up slope scarps, and lateral cracks are recognized from LiDAR derived 1 m resolution
DEM. Among these, 16 sites are selected for field investigation and all of them are confirmed
as deep seated landslides. This implies the reliability of interpretation results from LiDAR
derived DEM even in heavy forest region such as Taiwan. In order to know the influence
of the Meilungshan fault in the development of deep seated landslides, landslide
density are calculated. The landslide density is 7.7% when whole watershed is
considered. However, the landslide density significantly increases to 19.3% when
only an area 223km2 that contains the Meilungshan fault with a 2km buffer zone
is in the calculation. This result indicates that deformation zone associated with
major fault is crucial in the development of deep seated landslides in the study area. |
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