 |
| Titel |
Rainfall-induced landslides in Laolung River watershed, Southern Taiwan |
| VerfasserIn |
C.-W. Lin, C.-H. Chen, W.-S. Chang, S.-H. Liu |
| Konferenz |
EGU General Assembly 2009
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250026913
|
|
|
|
|
|
| Zusammenfassung |
| The Laolung River watershed in southern Taiwan which covered 1367 Km2 is chosen to
study the characteristics of rainfall induced landslide and to evaluate the impact of the
Chi-Chi earthquake on landslides. The study area has suffered slight to moderate horizontal
ground motion 50-300 PGA and only a few coseismic landslides occurred in the earthquake.
To evaluate the impact of the earthquake, the PGA of the earthquake was correlated to the
occurrence of landslides, the landslide intensity, and the corresponding rainfall data of each
typhoon.
The landslides of the study area were identified through 8 SPOT and 8 FORMOSAT 2
images that covered 15 typhoons from 1996 to 2007. The corresponding rainfall information
in places where landslides occurred is interpolated from one hour interval rainfall data by
using Kriging method.
The study results show the landslide intensity obtained from images is well correlate to
the corresponding cumulative precipitation of typhoons except for those occurred in typhoon
Billis in 2000, Toraji in 2001, and 0609 event in 2003. In Billis, Toraji, and 0609
events, landslide intensity in area with PGA over 150 gal is larger than that obtained
form area with PGA under 150 gal without regarding the cumulative rainfall and
rainfall intensity. In addition, most of landslides distributed in areas with slopes of
30o–40o which is typical for rainfall induced landslides except for those occurred in
area with PGA over 150 gal during Billis, Toraji, and 0609 event which mainly
distributed in places with slopes between 40o-50o. Therefore, we conclude that the
influence of the Chi-Chi earthquake on rainfall induced landslides in the Laolung River
watershed is only seen in area with PGA over 150 gal and it sustains only 3-4 years. |
|
|
|
|
|
|