When image correlation is needed: Unravelling the complex dynamics of a slow-moving landslide in the tropics with dense radar and optical time series
Authors
Dille, A.
Kervyn, F.
Handwerger, A.
d Oreye, N.
Derauw, D.
Mugaruka Bibentyo, T.
Samsonov, S.
Malet, J.-P.
Kervyn, M.
Dewitte, O.
Discipline
Earth and related Environmental sciences
Subject
Natural hazards
Audience
Scientific
Date
2021Metadata
Show full item recordDescription
Slow-moving landslides exhibit persistent but non-uniform motion at low rates which makes them exceptional natural laboratories to study the mechanisms that control the dynamics of unstable hillslopes. Here we leverage 4.5+ years of satellite-based radar and optical remote sensing data to quantify the kinematics of a slow-moving landslide in the tropical rural environment of the Kivu Rift, with unprecedented high spatial and temporal resolution. We measure landslide motion using sub-pixel image correlation methods and invert these data into dense time series that capture weekly to multi-year changes in landslide kinematics. We cross-validate and compare our satellite-based results with very-high-resolution Unoccupied Aircraft System topographic datasets, and explore how rainfall, simulated pore-water pressure, and nearby earthquakes control the overall landslide behaviour. The landslide exhibited seasonal and multi-year velocity variations that varied across the landslide kinematic units. While rainfall-induced changes in pore-water pressure exerts a primary control on the landslide motion, these alone cannot explain the observed variability in landslide behaviour. We suggest instead that the observed landslide kinematics result from internal landslide dynamics, such as extension, compression, material redistribution, and interactions within and between kinematic units. Our study provides, a rare, detailed overview of the deformation pattern of a landslide located in a tropical environment. In addition, our work highlights the viability of sub-pixel image correlation with long time series of radar-amplitude data to quantify surface deformation in tropical environments where optical data is limited by persistent cloud cover and emphasize the importance of exploiting synergies between multiple types of data to capture the complex kinematic pattern of landslides.
Citation
Dille, A.; Kervyn, F.; Handwerger, A.; d Oreye, N.; Derauw, D.; Mugaruka Bibentyo, T.; Samsonov, S.; Malet, J.-P.; Kervyn, M.; Dewitte, O. (2021). When image correlation is needed: Unravelling the complex dynamics of a slow-moving landslide in the tropics with dense radar and optical time series. , Remote Sensing of Environment, Vol. 258, 112402, DOI: https://doi.org/10.1016/j.rse.2021.112402.Identifiers
Type
Article
Peer-Review
Yes
Language
eng