Rheology of a Debris Slide From the Joint Analysis of UAVSAR and LiDAR Data

Landslide rheology governs the deformation and flow behavior of sliding masses. As rheology strongly varies as a function of the composition and environment of landslides, a wide range of viscosities have been suggested based on very limited experimental or observational constraints. Here, we introduce a novel method to quantify the landslide rheology from remote sensing data. We focus on an ideal natural laboratory, the Slumgullion landslide, Colorado, which has moved at tens of millimeters per day for centuries. A joint analysis of Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) Interferometric Synthetic Aperture Radar (InSAR)-derived surface displacements and Light Detection and Ranging (LiDAR) Digital Elevation Model (DEM)-derived landslide thickness at its frontal toe allows us to invert for the intrinsic viscosity (10(9)-10(11.5) Pa center dot s under different degrees of plasticity) based on the Bingham plastic model. Detailed displacement measurements also elucidate local variations in magnitude and orientation. Our method presents the capability of remote sensing data to understand the rheology of quasi-static debris slides in general.