Both landslide mapping and volume estimation accuracy are crucial to quantify landscape evolution and to manage such natural hazard. We developed a consistent method to robustly detect Landslides and measure volume directly from repeat 3D point cloud LiDAR data. This method allows to detect more landslides than classical 2D inventories and resolve known issues of indirect volume measurement. Our results also suggest that the number of small landslides classically detected is underestimated.

Mountain rivers are characterized by large fluctuations of water flow, including both flood and inter-flood low flow. Recently, increasing attention has been paid on how inter-flood low flow affects the sediment transport in subsequent flood. Here we present a series of flume experiments. Results show that the existence of inter-flood low flow can reduce the sediment transport at the beginning of the subsequent flood. However, such effect is gradually erased with the increase of flow intensity.

Soil erosion and suspended sediment transport understanding is an important issue in terms of soil and water resources management. This study analyzes the impact of choices made during numerical model set-up on the modelled suspended sediment dynamics at the outlet of two meso scale watersheds. While the modelled liquid and solid discharges were found to be sensitive to these choices, the actual location of sediment sources in each catchment was the most important feature.

Plate tectonics drives the formation of mountain ranges. Yet when tectonic forces cease, mountain ranges persist for hundreds of millions of years, forming major Earth surface features. Our contribution presents denudation rate estimates from one such ancient mountain range that show that denudation is strongly tied to rock type. Resistant rocks are denuding more slowly despite having much steeper topography and contrasts in rock type cause increasing relief in the absence of active tectonics.

The cooling climate of the last few million years leading into the ice ages has been linked to increasing erosion rates by glaciers. One of the ways to measure this is through mineral cooling ages. In this paper, we investigate potential bias in these data and the methods used to analyse them. We find that the data are not themselves biased, but that appropriate methods must be used. Past studies have used appropriate methods, and are sound in methodology.

This paper explores how the geometry of rill networks contributes to observed nonlinear relationships between soil loss and hillslope length. This work develops probability functions of geometrical quantities of the networks and then extends the theory to hydraulic variables by relying on well-known relationships. Theory is complemented by numerical modeling on numerical and natural surfaces. Results suggest that the particular arrangement of rill networks contributes to nonlinear relationships.

This study demonstrates an innovative methodology to estimate the formative discharge of alluvial rivers from remote sensing images. We have developed an automated algorithm in python-3 to extract the width of a river channel from satellite images. Finally, this channel width is translated into to discharge by using a semi-empirical regime equation developed from field measurements and threshold channel theory, that explains the first-order geometry of alluvial channels.

Wave-transported boulders are important records for storm and tsunami impact over geological timescales. Their use for hazard assessment requires chronological information. We investigated the potential of a new dating technique, luminescence rock surface exposure dating, for estimating transport ages of wave-emplaced boulders. Our results show that the new approach may provide chronological information over decadal to millennial timescales for boulders not datable by any other method so far.

This paper presents a novel method of estimating the relative contribution of different physical scales of river bed topography to the total drag, expressed as k_s. The approach requires only a longitudinal profile with sufficient resolution and spatial coverage to include the important roughness elements. The estimates of k_s may be used in conventional flow resistance equations, in place of representative roughness metrics such as grain size or the standard deviation of elevations.

In this study, we comprehensively test a method to derive soil densities under fieldwork conditions. The method is mainly based on images taken from consumer-grade cameras. The obtained soil/sediment densities reflect true values by generally > 95 %, even if a smartphone is used for imaging. All computing steps can be conducted using freeware programs. Soil density is an important variable in the analysis of terrestrial cosmogenic nuclides, e.g. to infer long-term soil production rates.

In this work, we use 3D point clouds to detect topographic changes across the surface of a rock glacier. These changes are presented as the relative contribution of surface change during a three-week period of snow-free conditions to the annual surface change. By comparing these different time periods and looking at change in different directions, we show that different directions of surface change are dominant at different times of the year. This demonstrates the benefit of freguent monitoring.

We measured the shear strength of marsh soils along an estuarine salinity gradient to determine salinity's influence on marsh erodibility. Our work is one of the first studies to directly examine the relationship between salinity and marsh erodibility. We find that an increase in salinity correlates to higher soil shear strength values, indicating that salt marshes may be more resistant to erosion. We also show that both belowground biomass and soil properties drive shear strength differences.

We collected soil surface samples and depth profiles every 5 cm (up to 30 cm) from eleven ice-free areas along the Shackleton Glacier, a major outlet glacier of the East Antarctic Ice Sheet (EAIS) and measured meteoric beryllium-10 and nitrate concentrations to calculate and estimate surface exposure ages. We show that the Shackleton Glacier has the greatest fluctuations near the terminus while tributary glaciers are more stable, reflecting the sensitivity of the EAIS to climate shifts.

River behavior depends on the size of rocks they carry. Rocks are born on hillslopes where erosion removes fragments from solid bedrock. To understand what controls the size of rock fragments, we measured the spacing between cracks exposed in 15 bare-rock cliffs, and the size of rocks on the ground below. We found that, for each site, the average rock size could be predicted from the average distance between cracks, which varied with rock type. This shows how rock type can influence rivers.

Coastal marshes are valuable natural habitats with normally dense vegetation. The presence of bare patches is a symptom of habitat degradation. We found that the occurrence of bare patches and regrowth of vegetation, is related to spatial variations in soil surface elevation, and to distance and connectivity to tidal creeks. These relations are similar in three marshes at very different geographical locations. Our results may help nature managers to conserve and restore coastal marshes.

The magnitude of cooling in tropical high mountains during the last glacial period is controversially debated. Here, we report on enigmatic large sorted stone polygons and stripes from the ~ 4000 m high Sanetti Plateau in Ethiopia. Geomorphological features of that size are associated with seasonal or permanent frost and have yet only been described for few locations in the mid and high latitudes. The presence of these features implies a strong tropical cooling at high elevations in the past.

Arid ecosystem health is a complex interaction between vegetation and climate and with impacts from grazing can result in quick changes in vegetation cover. We present a wind erosion and vegetation health model with active grazers over 100-year long tests to find the limits of arid environments for different levels of vegetation, rainfall, windspeed, and grazing. The model shows the resilience of grassy landscapes to grazing and its role as an improved tool for managing arid landscapes.