Long-Term Satellite Monitoring of the Slumgullion Landslide Using Space-Borne Synthetic Aperture Radar Sub-Pixel Offset Tracking

Donato Amitrano,Raffaella Guida,Gerardo Di Martino,Domenico Dell’Aglio,Federico Minati,Antonio Iodice,Mario Costantini,Diego Di Martire,Fabio Malvarosa

doi:10.3390/rs11030369

Abstract

Kinematic characterization of a landslide at large, small, and detailed scale is today still rare and challenging, especially for long periods, due to the difficulty in implementing demanding ground surveys with adequate spatiotemporal coverage. In this work, the suitability of space-borne synthetic aperture radar sub-pixel offset tracking for the long-term monitoring of the Slumgullion landslide in Colorado (US) is investigated. This landslide is classified as a debris slide and has so far been monitored through ground surveys and, more recently, airborne remote sensing, while satellite images are scarcely exploited. The peculiarity of this landslide is that it is subject to displacements of several meters per year. Therefore, it cannot be monitored with traditional synthetic aperture radar differential interferometry, as this technique has limitations related to the loss of interferometric coherence and to the maximum observable displacement gradient/rate. In order to overcome these limitations, space-borne synthetic aperture radar sub-pixel offset tracking is applied to pairs of images acquired with a time span of one year between August 2011 and August 2013. The obtained results are compared with those available in the literature, both at landslide scale, retrieved through field surveys, and at point scale, using airborne synthetic aperture radar imaging and GPS. The comparison showed full congruence with the past literature. A consistency check covering the full observation period is also implemented to confirm the reliability of the technique, which results in a cheap and effective methodology for the long-term monitoring of large landslide-induced movements.

Highlights

The kinematic estimation of landslide deformation is an important task for investigating the mechanisms affecting their evolution
All the results presented here have been obtained after re-projection of synthetic aperture radar (SAR) images into a cartographic system using the National Center for Airborne Laser Mapping (NCALM) LIDAR Digital Elevation Model (DEM)
Satellite technologies have widely demonstrated their potential in environmental monitoring and forecasting, response, and recovery of natural hazards

Summary

Introduction

The kinematic estimation of landslide deformation is an important task for investigating the mechanisms affecting their evolution. Recent years have been characterized by a rising interest in and exploitation of satellite technologies for the monitoring of active ground deformation, including landslide motion and hillslope creep, allowing for the overcoming of the insufficient spatiotemporal coverage achievable through traditional monitoring methods In this sense, Differential Synthetic Aperture Radar Interferometry (DInSAR) techniques have largely demonstrated their effectiveness in measuring surface motion and deformation at different scales [2,3,4,5,6]. Differential Synthetic Aperture Radar Interferometry (DInSAR) techniques have largely demonstrated their effectiveness in measuring surface motion and deformation at different scales [2,3,4,5,6] The spread of this methodology is mainly related to Permanent Scatterers (PS) [7] and Small BAseline Subset (SBAS) [3] approaches, and their combination (known as SqueeSAR) [8,9,10]. These methods are subject to some restrictions, such as the presence of vegetation (causing temporal decorrelation even within very short time intervals) and the 1-D line of sight (LOS) measurement sensitivity, which is constrained by the adopted wavelength relatively to the maximum measurable displacement rate [11,12]

Methods

Results

Discussion

Conclusion