Topographic precursors and geological structures of deep-seated catastrophic landslides caused by Typhoon Talas

Chigira, Masahiro; Tsou, Ching-Ying; Matsushi, Yuki; Hiraishi, Narumi; Matsuzawa, Makoto

doi:10.1016/j.geomorph.2013.07.020

Cited by 119 publications

(113 citation statements)

References 31 publications

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“…The precipitation for 72 hours in the study area registered more than 1000 mm. The heavy rainfall triggered more than 70 deep-seated landslides in the study area [19]. It is found from Figure 2 that the dominant scattering process in those landslides is the surface scattering, while the non-landslide (vegetated) area shows "green" corresponding to the dominance of the volume scattering.…”

Section: Model-based Scattering Power Decompositionmentioning

confidence: 92%

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Polarimetric Scattering Properties of Landslides in Forested Areas and the Dependence on the Local Incidence Angle

2015

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This paper addresses the local incidence angle dependence of several polarimetric indices corresponding to landslides in forested areas. Landslide is deeply related to the loss of human lives and their property. Various kinds of remote sensing techniques, including aerial photography, high-resolution optical satellite imagery, LiDAR and SAR interferometry (InSAR), have been available for landslide investigations. SAR polarimetry is potentially an effective measure to investigate landslides because fully-polarimetric SAR (PolSAR) data contain more information compared to conventional single-or dual-polarization SAR data. However, research on landslide recognition utilizing polarimetric SAR (PolSAR) is quite limited. Polarimetric properties of landslides have not been examined quantitatively so far. Accordingly, we examined the polarimetric scattering properties of landslides by an assessment of how the decomposed scattering power components and the polarimetric correlation coefficient change with the local incidence angle. In the assessment, PolSAR data acquired from different directions with both spaceborne and airborne SARs were utilized. It was found that the surface scattering power and the polarimetric correlation coefficient of landslides significantly decrease with the local incidence angle, while these indices of surrounding forest do not. This fact leads to establishing a method of effective detection of landslide area by polarimetric information. OPEN ACCESSRemote Sens. 2015, 7 15425

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Section: Model-based Scattering Power Decompositionmentioning

confidence: 92%

“…A typical deep-seated landslide in the study area is shown in Figure 3. The area of the landslide is 437,500 m 2 [19]. …”

Section: Model-based Scattering Power Decompositionmentioning

confidence: 99%

Polarimetric Scattering Properties of Landslides in Forested Areas and the Dependence on the Local Incidence Angle

2015

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“…These landslide signatures are also the major indicators that are used for field investigations and aerial photo interpretations. Chigira et al [24] illustrated that some large, catastrophic landslides that were induced by Typhoon Talas in 2011 were preceded by deep-seated gravitational slope deformation. The series of deep-seated landslides identified from the LiDAR DEM are documented in the eastern part of the study area [50] (see Figure 1).…”

Section: Interpretation Of Deep-seated Landslidesmentioning

confidence: 99%

“…The presence of dense vegetation and topographic complexities reduced the number of ground laser strikes, thereby generating low-density ground data that failed to capture subtle geomorphic features. Chigira et al [24] analyzed LiDAR-derived high-resolution DEMs captured before and after Typhoon Talas in 2011 and found that 10 large catastrophic landslides were preceded by gravitational slope deformation. In the LiDAR-derived DEMs that was generated before the typhoon, small scarps can be detected near their future crowns prior to the slide.…”

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confidence: 99%

Detecting and Characterizing Active Thrust Fault and Deep-Seated Landslides in Dense Forest Areas of Southern Taiwan Using Airborne LiDAR DEM

et al. 2015

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Steep topographic reliefs and heavy vegetation severely limit visibility when examining geological structures and surface deformations in the field or when detecting these features with traditional approaches, such as aerial photography and satellite imagery. However, a light detection and ranging (LiDAR)-derived digital elevation model (DEM), which is directly related to the bare ground surface, is successfully employed to map topographic signatures with an appropriate scale and accuracy and facilitates measurements of fine topographic features. This study demonstrates the efficient use of 1-m-resolution LiDAR for tectonic geomorphology in forested areas and to identify a fault, a deep-seated landslide, and the regional cleavage attitude in southern Taiwan. Integrated approaches that use grayscale slope images, openness with a tint color slope visualization, the three-dimensional (3D) perspective of a red relief image map, and a field investigation are employed to identify the aforementioned features. In this study, the previously inferred Meilongshan Fault is confirmed as a NE-SW-trending, eastern dipping thrust with at least a 750 m-wide deformation zone. The site where future paleoseismological studies should be performed has been identified, and someone needs to work further on this site. Signatures of deep-seated landslides, such as double ridges, trenches, main escarpments, and extension cracks, are successfully differentiated in LiDAR DEM images through the use of different

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“…Reference [5] states that debris flow in Xiaojiagou, Sichuan Province has two (2) types, namely the hill-slope debris flow and channelised debris flow. The characteristics of the landslide are based on geological, geotechnical and geomorphological study as conducted by researchers [6], [7], [8], and [9]. Reference [7] investigates gully erosion.…”

Section: Introductionmentioning

confidence: 99%

Mechanism and Characteristics of the Landslides in Bone Bolango Regency, Gorontalo Province, Indonesia

Patuti¹

2017

geomate

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ABSTRACT:One of the regencies in Gorontalo Province, Indonesia, Bone Bolango is an area in which landslides occur frequently. This study was at identifying the mechanism and characteristics of landslides in Bone Bolango Regency. This study is important to minimize hazards caused by this disaster. Data were obtained from the results of site survey, surface geological survey and geotechnical investigation. Cohesion during the dry season ranged between 0-15kPa, and the angle of internal friction ranged between 30 o -44 o . The topography of this area indicates a steep slope (>40°), with weathered rock and discontinuity. These internal factors made the slopes prone to landslide. Meanwhile, external factors that trigger landslides are high precipitation (>100mm), the absence of vegetation covering the slopes, as well as land use on the slopes. In general, the types of the landslide in the study area were debris flows, rotational slides, and rock falls. At the period of high precipitation, the rate of infiltration of rainwater into the soil was slower than the rate of the increase in the volume of rainwater deposited and flowing into the slope surface, resulting in the debris flow. Slope-forming material became soft due to the rise of groundwater levels. This caused a decrease in shear strength and pore water pressure that turned into positive. In the rock slope, rainwater filled the crack of slope discontinuity area so that rock got loose and fell freely. Therefore, a further research is necessary to conduct in order to determine the most accurate and efficient method for slope stability.

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Topographic precursors and geological structures of deep-seated catastrophic landslides caused by Typhoon Talas

Cited by 119 publications

References 31 publications

Polarimetric Scattering Properties of Landslides in Forested Areas and the Dependence on the Local Incidence Angle

Polarimetric Scattering Properties of Landslides in Forested Areas and the Dependence on the Local Incidence Angle

Detecting and Characterizing Active Thrust Fault and Deep-Seated Landslides in Dense Forest Areas of Southern Taiwan Using Airborne LiDAR DEM

Mechanism and Characteristics of the Landslides in Bone Bolango Regency, Gorontalo Province, Indonesia

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