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| Titel |
A study of large scaled landslide susceptibility by using Weight-of-Evidence method: A case study from the Laonung River Watershed, Southern Taiwan |
| VerfasserIn |
Chih-Hao Chen, 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 |
250075425
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| Zusammenfassung |
| The Laonung River watershed which covered an area 1367 km2 is selected as the study area
to construct large scaled landslides susceptibility model by using Weight-of-Evidence
method. Within the study area, 950 landslides with an area more than 10 ha are identified
from FORMOSAT 2 images, aerial photos, and LiDAR derived 1 m high resolution
Digital-Elevation-Model (DEM) taken after typhoon Moratko in 2009. Among these, 271
landslides occurred recently and they show bare ground in aerial photos and satellite images.
318 landslides are vegetation recovery, and they are inferred from their topographic
characteristics by using aerial photos with topographic map. Additionally, 361 landslides with
topographic features of deep seated landslide such as crown main escarpment, down slop
scarp, up slop scarp, and transverse cracks are identified from 1m resolution LiDAR derived
DEM.
Weight-of-Evidence method is a bivariate statistical approach which uses the concept of
Bayes’ theorem and odds ratio to calculate the weighting of each evaluation parameter. In this
study, ten parameters including slope gradient, slope aspect, landform, elevation, lithology,
dip-slope, undercut slope, normalized difference vegetation index (NDVI), the distance from
geological structure and the distance from stream are selected as evaluation factors. For
each parameter, the weighting for landslide susceptibility is calculated, and the
weighting of all parameters are then summed to generate the landslide susceptibility
map.
The study results show the area under the success rate curves reaching 80%, and
70% of large scaled landslides falls within top 30% susceptibility index. It implies
that the susceptibility model constructed by this study can effectively predict the
location of large scaled landslides in the study area. The results can benefit to the
management of mitigation plan of the large scaled landslides in southern Taiwan. |
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