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Titel |
Post-disaster assessment of landslides in southern Taiwan after 2009 Typhoon Morakot using remote sensing and spatial analysis |
VerfasserIn |
F. Tsai, J.-H. Hwang, L.-C. Chen, T.-H. Lin |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1561-8633
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Digitales Dokument |
URL |
Erschienen |
In: Natural Hazards and Earth System Science ; 10, no. 10 ; Nr. 10, no. 10 (2010-10-19), S.2179-2190 |
Datensatznummer |
250008450
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Publikation (Nr.) |
copernicus.org/nhess-10-2179-2010.pdf |
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Zusammenfassung |
On 8 August 2009, the extreme rainfall of Typhoon Morakot triggered enormous
landslides in mountainous regions of southern Taiwan, causing catastrophic
infrastructure and property damages and human casualties. A comprehensive
evaluation of the landslides is essential for the post-disaster
reconstruction and should be helpful for future hazard mitigation. This paper
presents a systematic approach to utilize multi-temporal satellite images and
other geo-spatial data for the post-disaster assessment of landslides on a
regional scale. Rigorous orthorectification and radiometric correction
procedures were applied to the satellite images. Landslides were identified
with NDVI filtering, change detection analysis and interactive post-analysis
editing to produce an accurate landslide map. Spatial analysis was performed
to obtain statistical characteristics of the identified landslides and their
relationship with topographical factors. A total of 9333 landslides
(22 590 ha) was detected from change detection analysis of satellite
images. Most of the detected landslides are smaller than 10 ha. Less than
5% of them are larger than 10 ha but together they constitute more than
45% of the total landslide area. Spatial analysis of the detected landslides
indicates that most of them have average elevations between 500 m to 2000 m
and with average slope gradients between 20° and 40°. In
addition, a particularly devastating landslide whose debris flow destroyed a
riverside village was examined in depth for detailed investigation. The
volume of this slide is estimated to be more than 2.6 million m3 with an
average depth of 40 m. |
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