TY - JOUR
T1 - Extracting region-specific runout behavior and rainfall thresholds for massive landslides using seismic records
T2 - a case study in southern Taiwan
AU - Hung, Ching
AU - Lin, Guan Wei
AU - Leshchinsky, Ben
AU - Kuo, Hsien Li
N1 - Funding Information:
This work was generously supported by the Ministry of Science and Technology, Taiwan. The authors are grateful to Academic Sinica and Central Weather Bureau, Taiwan for providing seismic records of the broadband array of Taiwan system. We also would like to thank Aerial Survey Office, Forestry Bureau, Taiwan, which provided the remote sensing images and digital terrain model for this study.
Publisher Copyright:
© 2018, Springer-Verlag GmbH Germany, part of Springer Nature.
PY - 2019/9/1
Y1 - 2019/9/1
N2 - Typhoon Morakot struck Taiwan on 7 August 2009, bringing severe rainfall and landslides. Of the many landslides caused by the storm, 12 large-scale landslides were discovered based on seismic signals recorded from broadband seismic stations. Landslides inventoried from both seismic records and satellite imagery are used as baseline data to evaluate region-specific forensic analyses of landslide features, e.g. disturbed area, width and runout distance (Drunout), associated with landslide-induced seismic signals and signal durations (Δt). The results of these analyses show that (i) the landslide-disturbed area correlated well with signal duration when Δt was over 60 s; (ii) the landslide-disturbed area correlated well with the ratio of the landslide width to runout distance when Δt was under 40 s; (iii) the runout distance of sliding mass exhibited a positive relation with Δt2, satisfying the energy conserved during mass movement. This case study presents a region-specific examination of the Δt-Drunout relationship based on 12 large-scale landslides that occurred during Typhoon Morakot, providing insight into the sliding processes. In addition, the time of landslide initiation was extracted from seismic signals in order to better understand region-specific, large-scale, landslide rainfall thresholds. These relationships indicate that (a) long-duration rainstorms with high cumulative rainfall tend to dictate the occurrence of large-scale landslides; (b) the rainfall threshold for large-scale landslides is found to be higher than in previous studies that also include smaller landslides, defined in this region as I = 60D−0.31, where I is the rainfall intensity (mm/h) and D is the duration (h) of the rainstorm.
AB - Typhoon Morakot struck Taiwan on 7 August 2009, bringing severe rainfall and landslides. Of the many landslides caused by the storm, 12 large-scale landslides were discovered based on seismic signals recorded from broadband seismic stations. Landslides inventoried from both seismic records and satellite imagery are used as baseline data to evaluate region-specific forensic analyses of landslide features, e.g. disturbed area, width and runout distance (Drunout), associated with landslide-induced seismic signals and signal durations (Δt). The results of these analyses show that (i) the landslide-disturbed area correlated well with signal duration when Δt was over 60 s; (ii) the landslide-disturbed area correlated well with the ratio of the landslide width to runout distance when Δt was under 40 s; (iii) the runout distance of sliding mass exhibited a positive relation with Δt2, satisfying the energy conserved during mass movement. This case study presents a region-specific examination of the Δt-Drunout relationship based on 12 large-scale landslides that occurred during Typhoon Morakot, providing insight into the sliding processes. In addition, the time of landslide initiation was extracted from seismic signals in order to better understand region-specific, large-scale, landslide rainfall thresholds. These relationships indicate that (a) long-duration rainstorms with high cumulative rainfall tend to dictate the occurrence of large-scale landslides; (b) the rainfall threshold for large-scale landslides is found to be higher than in previous studies that also include smaller landslides, defined in this region as I = 60D−0.31, where I is the rainfall intensity (mm/h) and D is the duration (h) of the rainstorm.
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U2 - 10.1007/s10064-018-1384-5
DO - 10.1007/s10064-018-1384-5
M3 - Article
AN - SCOPUS:85053500434
SN - 1435-9529
VL - 78
SP - 4095
EP - 4105
JO - Bulletin of Engineering Geology and the Environment
JF - Bulletin of Engineering Geology and the Environment
IS - 6
ER -