Recent satellite-based radar and optical monitoring of the activity of retrogressive slow-moving landslides in Nepal during monsoon
Abstract
The steep Himalayan slopes are highly susceptible to landslides, primarily triggered by earthquakes and intense monsoon precipitation. Along the southern flank of the Himalayas, a specific type of landslide affects old, destabilized hillslopes characterized by intense internal fracturing and prone to rapid retrogressive erosion through deep gully incision, ultimately leading to the catastrophic collapse of secondary slides. Understanding these mechanisms requires identifying potential spatiotemporal relationships between landslide units and triggering factors such as rainfall, increased groundwater pressure, and gully erosion. In this study, high-resolution optical and radar satellite remote sensing data were integrated to characterize the dynamics of three retrogressive, slow-moving landslides located in the Marsyangdi and Khudi valleys of central Nepal. The combination of digital surface model (DSM) differencing and optical pixel-tracking from very high resolution Pléiades imagery provides a comprehensive view of the three-dimensional surface displacement fields across the landslides, offers insights into their internal kinematics, and highlights how gully downcutting drives landslide activity through basal destabilization. Our dataset also demonstrates that high-temporal-resolution displacement measurements derived from SAR amplitude imagery enable tracking of landslide dynamics during slow- to moderate-activity phases (displacement >= 0.5 m). In the specific case of the retrogressive landslides studied here in central Nepal, we identify various nonlinear responses to changes in groundwater table level: either involving strain hardening effects, or early destabilization of a lower unit followed by large displacements in the main landslide body.
Related
- Initiation mechanism of irrigation-induced retrogressive loess landslides on the South Jingyang Tableland, China
- R&D activity in INAF on light instrumentation for continuous optical turbulence monitoring
- Monitoring Carbon Hotspots in Patchy Landscapes from Sparse Lidar and Dense Satellite Time Series
- Active and passive satellite observations coupled with carbon–nitrogen synergy for urban fossil fuel CO 2 emissions monitoring
- Training-Free Monitoring of Kenya with Pre-computed Satellite Embeddings: Lake Expansion, Construction Dating and Crop Retrieval with TESSERA
BibTeX
@article{leder2026recent,
title = {{Recent satellite-based radar and optical monitoring of the activity of retrogressive slow-moving landslides in Nepal during monsoon}},
author = {Florian Leder and Simon Daout and Jérôme Lavé and Pascal Lacroix and Nicolas D’oreye de Lantremange},
journal = {Geomorphology},
year = {2026},
month = oct,
doi = {10.1016/j.geomorph.2026.110561},
url = {https://hal.science/hal-05829401v1},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Recent satellite-based radar and optical monitoring of the activity of retrogressive slow-moving landslides in Nepal during monsoon
AU - Florian Leder
AU - Simon Daout
AU - Jérôme Lavé
AU - Pascal Lacroix
AU - Nicolas D’oreye de Lantremange
PY - 2026
DA - 2026/10/26
JO - Geomorphology
DO - 10.1016/j.geomorph.2026.110561
UR - https://hal.science/hal-05829401v1
AB - The steep Himalayan slopes are highly susceptible to landslides, primarily triggered by earthquakes and intense monsoon precipitation. Along the southern flank of the Himalayas, a specific type of landslide affects old, destabilized hillslopes characterized by intense internal fracturing and prone to rapid retrogressive erosion through deep gully incision, ultimately leading to the catastrophic collapse of secondary slides. Understanding these mechanisms requires identifying potential spatiotemporal relationships between landslide units and triggering factors such as rainfall, increased groundwater pressure, and gully erosion. In this study, high-resolution optical and radar satellite remote sensing data were integrated to characterize the dynamics of three retrogressive, slow-moving landslides located in the Marsyangdi and Khudi valleys of central Nepal. The combination of digital surface model (DSM) differencing and optical pixel-tracking from very high resolution Pléiades imagery provides a comprehensive view of the three-dimensional surface displacement fields across the landslides, offers insights into their internal kinematics, and highlights how gully downcutting drives landslide activity through basal destabilization. Our dataset also demonstrates that high-temporal-resolution displacement measurements derived from SAR amplitude imagery enable tracking of landslide dynamics during slow- to moderate-activity phases (displacement >= 0.5 m). In the specific case of the retrogressive landslides studied here in central Nepal, we identify various nonlinear responses to changes in groundwater table level: either involving strain hardening effects, or early destabilization of a lower unit followed by large displacements in the main landslide body.
SN - 0169-555X
SN - 0169-555X
ER -