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| Titel |
Assessment and Survey of Potential Catastrophic Landslides by Using Geomorphometric Analysis |
| VerfasserIn |
Yu-Chung Hsieh, Chin-Shyong Hou, Jyr-Ching Hu, Yu-Chang Chan, Li-Yuan Fei, Hung-Jen Chen, Cheng-Lung Chiu |
| 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 |
250078083
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| Zusammenfassung |
| In recent years, extreme weather events have induced more frequent geological hazards in
Taiwan. The heavy rainfall brought by the Typhoon Morakot has triggered a large
amount of landslides. The most unfortunate case occurred in the Hsiaolin village
which was totally demolished by a catastrophic landslide in less than a minute. The
study of such catastrophic landslides is urgently needed to mitigate loss of lives and
properties in the future. Traditionally, the study of landslides usually includes shallow
landslides, rockslide, and debris flow etc. and is commonly made use of satellite
images, aerial photos, coupled with field surveys. It is considered that the creep
phase of a landslide is a progressive stage of failure and gives sufficient signals
before turning into a catastrophic landslide. Due to lack of high quality terrain data,
however, the research of catastrophic landslides has been time consuming with often
unsatisfactory results. This study used high-resolution airborne LiDAR-derived
DEM data from the Central Geological Survey, MOEA. Different geomorphometric
analyses were applied to process the high resolution and high accuracy DEM data
including the hillshade, aspect, slope, eigenvalue ratio (ER) & openness. Among the
geomorphometric analyses, combining the characteristics of openness, slope and
hillshade gives a clear advantage to distinguish and analyze regions of potential
catastrophic landslides in many cases. Statistical and image processing techniques to
quantify morphological and other aspects of the terrain surface are also employed. Our
results indicate that over hundreds of potential catastrophic landslides may present
in southern Taiwan after the Typhoon Morakot event. The quantitative methods
used in this study highlight the terrain features of the creep phase of catastrophic
landslides and is helpful for landslide feature interpretation and hazard assessment. |
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