Landslide Activity Assessment of a Subtropical Area by Integrating InSAR, Landslide Inventory, Airborne LiDAR, and UAV Investigations: A Case Study in Northern Taiwan

Abstract. Several remote sensing techniques, namely traditional aerial photographs, an unmanned aircraft system (UAS), and airborne lidar, were used in this study to decipher the morphological features of obscure landslides in volcanic regions and how the observed features may be used for understanding landslide occurrence and potential hazard. A morphological reconstruction method was proposed to assess landslide morphology based on the dome-shaped topography of the volcanic edifice and the nature of its morphological evolution. Two large-scale landslides in the Tatun volcano group in northern Taiwan were targeted to more accurately characterize the landslide morphology through airborne lidar and UAS-derived digital terrain models and images. With the proposed reconstruction method, the depleted volume of the two landslides was estimated to be at least 820 ± 20  ×  106 m3. Normal faulting in the region likely played a role in triggering the two landslides, because there are extensive geological and historical records of an active normal fault in this region. The subsequent geomorphological evolution of the two landslides is thus inferred to account for the observed morphological and tectonic features that are indicative of resulting in large and life-threatening landslides, as characterized using the recent remote sensing techniques.

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Generating Substantially Complete Landslide Inventory using Multiple Data Sources: A Case Study in Northwest Himalayas, India

Journal of the Geological Society of India ◽

10.1007/s12594-020-1385-4 ◽

2020 ◽

Vol 95 (1) ◽

pp. 45-58 ◽

Cited By ~ 1

Author(s):

T. Ghosh ◽

S. Bhowmik ◽

P. Jaiswal ◽

S. Ghosh ◽

D. Kumar

Keyword(s):

Data Sources ◽

Landslide Inventory ◽

Multiple Data Sources ◽

Multiple Data ◽

Northwest Himalayas

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Using kites for 3-D mapping of gullies at decimetre-resolution over several square kilometres: a case study on the Kamech catchment, Tunisia

Natural Hazards and Earth System Science ◽

10.5194/nhess-18-1567-2018 ◽

2018 ◽

Vol 18 (6) ◽

pp. 1567-1582 ◽

Cited By ~ 9

Author(s):

Denis Feurer ◽

Olivier Planchon ◽

Mohamed Amine El Maaoui ◽

Abir Ben Slimane ◽

Mohamed Rached Boussema ◽

...

Keyword(s):

High Resolution ◽

Aerial Photography ◽

Airborne Lidar ◽

Data Set ◽

Topographic Data ◽

Independent Field ◽

Wide Range ◽

Laser Systems ◽

High Level

Abstract. Monitoring agricultural areas threatened by soil erosion often requires decimetre topographic information over areas of several square kilometres. Airborne lidar and remotely piloted aircraft system (RPAS) imagery have the ability to provide repeated decimetre-resolution and -accuracy digital elevation models (DEMs) covering these extents, which is unrealistic with ground surveys. However, various factors hamper the dissemination of these technologies in a wide range of situations, including local regulations for RPAS and the cost for airborne laser systems and medium-format RPAS imagery. The goal of this study is to investigate the ability of low-tech kite aerial photography to obtain DEMs with decimetre resolution and accuracy that permit 3-D descriptions of active gullying in cultivated areas of several square kilometres. To this end, we developed and assessed a two-step workflow. First, we used both heuristic experimental approaches in field and numerical simulations to determine the conditions that make a photogrammetric flight possible and effective over several square kilometres with a kite and a consumer-grade camera. Second, we mapped and characterised the entire gully system of a test catchment in 3-D. We showed numerically and experimentally that using a thin and light line for the kite is key for a complete 3-D coverage over several square kilometres. We thus obtained a decimetre-resolution DEM covering 3.18 km2 with a mean error and standard deviation of the error of +7 and 22 cm respectively, hence achieving decimetre accuracy. With this data set, we showed that high-resolution topographic data permit both the detection and characterisation of an entire gully system with a high level of detail and an overall accuracy of 74 % compared to an independent field survey. Kite aerial photography with simple but appropriate equipment is hence an alternative tool that has been proven to be valuable for surveying gullies with sub-metric details in a square-kilometre-scale catchment. This case study suggests that access to high-resolution topographic data on these scales can be given to the community, which may help facilitate a better understanding of gullying processes within a broader spectrum of conditions.

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