Preprints
Filtering by Subject: Geomorphology
SCI-DEM: A Method for Generating Digital Beach Surfaces from Tide and Waterline Timeseries
Published: 2026-10-27
Subjects: Environmental Monitoring, Geomorphology, Oceanography
We present SCI-DEM, a method for deriving Digital Elevation Models (DEMs) of intertidal beach surfaces, profiles and beach widths from time-series waterlines using low-cost coastal CCTV cameras and modelled water levels. SCI-DEM builds on two established components: a waterline extraction method built on a semantic segmentation model, and a camera-pose-estimated homography, used to georeference [...]
Erosion-induced momentum production and system acceleration govern landslide mobility
Published: 2026-10-26
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Engineering, Environmental Sciences, Geology, Geomorphology, Geotechnical Engineering, Glaciology, Hydraulic Engineering, Hydrology, Physical Sciences and Mathematics, Risk Analysis, Sedimentology, Social and Behavioral Sciences
Erosion can fundamentally alter landslide acceleration through the produced momentum. However, existing analytical landslide velocity models do not account for the energy dissipation associated with erosion-induced system acceleration. Here, I present a novel, complete dynamical velocity model for erosive landslides that incorporates two intrinsically coupled mechanically essential processes: [...]
NepalDTM: A National 8-Metre Bare-Earth Digital Terrain Model of Nepal from Multi-Source Satellite Data Fusion
Published: 2026-10-24
Subjects: Earth Sciences, Geomorphology, Hydrology, Physical Sciences and Mathematics
NepalDTM is an open bare-earth elevation model of Nepal stored on an 8 m grid. Where the NASA High Mountain Asia 8 m stereo mosaic has a usable height, that mosaic is the surface. Elsewhere the surface is Copernicus GLO-30. A histogram gradient-boosting model, trained on 6,230,548 ICESat-2 points and 7,035,904 GEDI points, predicts how far the surface sits above the ground and subtracts that [...]
Post-event information in calendar-year satellite products inflates landslide susceptibility assessments
Published: 2026-10-20
Subjects: Geomorphology
Annual satellite products, such as the AlphaEarth Foundations and TESSERA embeddings, summarize a calendar year, so the product of a landslide's event year also contains post-event observations. We audited this post-event information in 18 dated events (7 earthquakes, 11 rainstorms; 61,402 landslides), changing only the input year within each event and keeping the points, spatial folds, models [...]
A steadily flowing glacier and no detectable precursor before the 11 October 2026 Budhi Gandaki rock–ice avalanche and flood, Nepal
Published: 2026-10-15
Subjects: Earth Sciences, Geomorphology
On 11 October 2026 at about 04:20 local time, a rock–ice avalanche at the head of the Ungilung Khola, on the southern slopes of Chamar (7,165 m) in Gorkha District, Nepal, became a debris flow and flood that travelled down the Syar Khola and the Budhi Gandaki. I reconstruct the event from free satellite data (Sentinel-1, Sentinel-2, Landsat 8/9, ITS_LIVE and NISAR), official records and my own [...]
Active hazardous slow faults drive drainage evolution in the Atacama Desert
Published: 2026-10-14
Subjects: Earth Sciences, Geology, Geomorphology, Hydrology, Tectonics and Structure
The Atacama Desert of the Central Andean forearc is the driest non-polar region on Earth, where extremely low erosion rates preserve geomorphic markers over Myr timescales. Between 19°S and 20°S, subtle Quaternary east-vergent reverse faults deform the west-sloping landscape and disrupt drainage development. This setting provides a unique opportunity to investigate fault evolution, uplift [...]
Quantifying volumetric erosion from symbolic expression of landslide morphology
Published: 2026-10-11
Subjects: Earth Sciences, Geomorphology, Mathematics, Physical Sciences and Mathematics
Landslide volumetric erosion is fundamental to regional sediment budgets and downstream hazard assessment, yet accurately constraining material mobilization remains a primary bottleneck in Earth-system research. Legacy area–volume relations introduce substantial uncertainty when applied across heterogeneous landslide populations. Here, we examine whether the erosional and accumulation (i.e., [...]
What constitutes fine-scale geodiversity? Taxonomic geodiversity mapping across environmental gradients in a sub-Arctic mountain environment
Published: 2026-09-24
Subjects: Geomorphology, Hydrology, Natural Resources and Conservation, Soil Science
The integration of geodiversity information, i.e., the diversity of abiotic features in the Earth surface and subsurface, into assessments of the sustainability and resilience of natural environments and ecosystems is increasingly considered important. However, geodiversity data is highly scale-dependent and there is an urgent need to find optimal ways on how geodiversity should be quantified and [...]
Three-Dimensional Numerical Modeling of Glacier Flow and U-Shaped Valley Evolution in Subtropical Taiwan
Published: 2026-09-24
Subjects: Earth Sciences, Geomorphology, Glaciology, Physical Sciences and Mathematics
Glacial erosion plays a critical role in shaping alpine topography,yet the coupled effects of ice deformation, basal sliding, andbedrock erosion on millennial-scale valley morphodynamics remainchallenging to quantify. This study presents three-dimensionalsimulations of glacier dynamics and bed evolution in Xue MountainGlacial Cirque No.~2, Taiwan, over an effective glaciation timescaleof 9~ka. [...]
Topology-Aware Quality Control of Triangulated Terrain Models Using Local Euler Curvature and Elevation-Filtration Curves
Published: 2026-09-19
Subjects: Earth Sciences, Environmental Sciences, Geomorphology, Mathematics, Physical Sciences and Mathematics
Triangulated irregular networks (TINs) are widely used to represent topography and bathymetry, but their quali-ty control is usually dominated by geometric criteria such as minimum angle and aspect ratio, which do not test whether connectivity errors have changed the topology of the mesh. We present a topology-aware quali-ty-control framework based on a local Euler-curvature identity and on [...]
Was the Pre-Event SWIR Anomaly at Tsangbu Ri a Genuine Glacier-Collapse Precursor? A Calibrated Multi-Glacier Test of the 2026 Case
Published: 2026-09-19
Subjects: Applied Statistics, Geographic Information Sciences, Geology, Geomorphology, Glaciology, Hydrology, Planetary Geology, Planetary Glaciology, Remote Sensing, Spatial Science, Tectonics and Structure
On 26 August 2026 a compound bedrock-and-glacier failure on the northern flank of the Langtang Lirung–Tsangbu Ri (Kimshung) massif, Nepal–China border, generated a rock–ice avalanche and a catastrophic downstream flood along the Bhotekoshi–Trishuli river system. A pre-event Sentinel-2 shortwave-infrared (SWIR2–NIR–Red) composite (12 August 2026) shows a sharply bounded, strongly saturated [...]
The single-pair unwrapping ceiling is a property of the track, not of the radar: Sentinel-1 evidence from rock–ice avalanches at Langtang Lirung and Ronti Peak
Published: 2026-09-18
Subjects: Earth Sciences, Geomorphology
This study asks what single-pair satellite data can detect before rock–ice avalanches, such as the Langtang Lirung (Nepal) and Ronti Peak (Chamoli, India) failures. The single-pair line-of-sight limit of 0.42 m yr⁻¹ for 12-day Sentinel-1 pairs is treated as a property of the radar, but the downslope ceiling depends on the track. I measure sensitivity to downslope motion f across Copernicus GLO-30 [...]
Very-high-resolution optical imagery reveals key clues to the Langtang Lirung ice–rock avalanche
Published: 2026-09-14
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics
Ice–rock avalanches and resulting cascading processes are increasingly recognized to pose an exceptional risk to high-mountain systems. Once initiated, they often transition from dense multiphase mixtures to water-saturated debris flows and even hyper-concentrated floods, thus attaining sufficient runout potential to move from highly remote to populated regions. The event that originated from the [...]
Bounded at both ends: the detection window of routine 12-day C-band InSAR at rock–ice avalanche sources
Published: 2026-09-14
Subjects: Earth Sciences, Geomorphology
A negative result from satellite radar — "no precursory deformation was detected" — carries no information unless the range of signals the measurement could have detected is reported alongside it. We measure that range at two rock–ice avalanche sources, Langtang Lirung, Nepal (2026) and Ronti Peak, India (2021), using a single procedure, and identify four determinants of it that are site-specific [...]
Calibrated detection limits in routine Sentinel-1 products 50.6 hours before the Langtang Lirung rock–ice avalanche, Nepal
Published: 2026-09-09
Subjects: Earth Sciences, Geomorphology
On 26 August 2026 a rock–ice avalanche detached from Langtang Lirung, Nepal, and released a debris flood that crossed the Nepal–China border. Deformation preceding the failure has since been reported from a multi-month Sentinel-1 stack, and pre-event indications have been identified in commercial optical imagery. Both analyses began from a known failure location. This paper asks a different [...]