Identifying slow-moving landslides using LiDAR DEM and SAR interferometry: An Example of 2006 Meinong Earthquake
Abstract
The February 6 Meinong Earthquake of 2016 (ML=6.4; at 23.85ºN, 120.81ºE), with a focal depth of 16.7 km, was triggered by an unknown blind thrust in southern Taiwan. The earthquake not only induced coseismic crustal deformation, but also triggered slow-moving landslides nearby the Longchuan active fault. In this study, high-resolution LiDAR derived DEM of 2010 is used to recognize locations of previous slow-moving landslides according to their topographic signatures, such as main escarpment, trench, double ridge, and crown cracks. Within an area of 4.5 km x 1.8 km along Longchuan fault near the ridge of Longchuan mountain, over 50 sites with landslide signatures are recognized, and three of them are over 10 ha. These earthquake-induced landslide deformations are detected from InSAR (synthetic aperture radar interferometry) images using Advanced Land Observing Satellite ALOS2/Phased-array L band and Sentinel 1 C-band SAR (PALSAR) data taken before and after the earthquake; some significant landslide deformation are even overlapped with areas where previous slow moving landslides were identified on the LiDAR DEM. Additionally, field investigation right after the earthquake in the study area also support that these previously identified landslides reactivated in the earthquake. Although these landslides do not cause serious damage due to their minor displacement in the Meinong Earthquake, the study results prove that LiDAR DEM is a powerful tool to identify and continuously monitor slow-motion landslides for preventing catastrophic failures that may be caused by hazardous earthquake or heavy rainfall.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2017
- Bibcode:
- 2017AGUFMNH43A0199C
- Keywords:
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- 1826 Geomorphology: hillslope;
- HYDROLOGY;
- 4319 Spatial modeling;
- NATURAL HAZARDS;
- 4333 Disaster risk analysis and assessment;
- NATURAL HAZARDS;
- 4337 Remote sensing and disasters;
- NATURAL HAZARDS