Post-disaster assessment of 2017 catastrophic Xinmo landslide (China) by spaceborne SAR interferometry

Abstract

Timely and effective post-disaster assessment is of significance for the 14 design of rescue plan, taking disaster mitigation measures and disaster analysis. Field 15 investigation and remote sensing methods are the common way to perform post-disaster 16 assessment, which are usually limited by dense cloud coverage, potential risk and tough 17 transportation etc. in the mountainous area. In this paper, we employ the 2017 18 catastrophic Xinmo landslide (Sichuan, China) to demonstrate the feasibility of using 19 spaceborne synthetic aperture radar (SAR) data to perform timely and effective post-20 disaster assessment. With C-band Sentinel-1 data, we propose to combine 21 interferometric coherence to recognize the stable area, which helps us successfully 22 identify landslide source area and boundaries in a space-based remote sensing way. 23Complementarily, X-band TanDEM-X SAR data allow us to generate a precise pre-24 failure high-resolution digital elevation model (DEM), which provides us the ability to 25 accurately estimate the depletion volume and accumulated volume of Xinmo landslide. 26The results prove that spaceborne SAR can provide a quick, valuable and unique 27 assistance for post-disaster assessment of landslides from a space remote sensing way. 28 This paper has to be cited as:

Diagnosis of Xinmo (China) Landslide Based on Interferometric Synthetic Aperture Radar Observation and Modeling

“…In order to answer these questions, we utilized InSAR analysis and the modeling of the deformation based on an elastic dislocation model. [1] and Dai et al [15]).…”

“…Then, the position and size (length: 420 m; width: 330 m; strike: 86 • clockwise from the North) of an Okada rectangle was given based on the failure boundary and the deformation region. The difference in the landslide topography before and after the collapse mostly ranged between 40 and 80 m [15,31]. Therefore, we set 60 m for the depth of the slip surface, which could be regarded as the average depth of the slip surface.…”

“…Based on Sentinel-1 data, Intrieri et al [14] recovered the pre-collapse time-series deformation of the Xinmo landslide. Dai et al [15] evaluated the disaster after the collapse based on Sentinel-1 SAR intensity data and estimated the terrain changes of the landslide source area. However, there are still some questions that have not been answered.…”

Pre-Event Deformation and Failure Mechanism Analysis of the Pusa Landslide, China with Multi-Sensor SAR Imagery

“…Yun et al [6] acquired damage proxy maps through changes in coherence maps, which were generated by pre-and post-event SAR images. Dai et al [7] combined interferograms and their corresponding coherence maps to identify the source region and boundary of the landslide.…”

Numerical Simulation of the 2017 Xinmo Catastrophic Landslide Considering Entrainment Effect

“…The elevation of the rear edge of the slip body is 3460 m a.s.l, the elevation of the shear opening location is about 3100 m a.s.l., and the average slope of the slip surface is about 47 • . The length and width of the collapsed rock mass are about 260 and 370 m, respectively, with a maximum thickness of about 66 m. Due to the different accuracies and sources of the pre-failure terrain data, several organizations and researchers had carried out volume estimations of the source mass, and the volume range of the landslide source mass is between 3.0 × 10 6 m 3 and 6.3 × 10 6 m 3 (Dai et al, 2019). The outcropping strata in this area is part of the Middle Triassic Zagunao Formation (T 2 z), mainly consisting of metamorphic sandstone intercalated with slate (Figure 4).…”