Rivers transport microplastic pollution from its source to its eventual marine sink. Rivers are not simple conveyor belts of this pollution. Microplastic will become entrained within the sediments, becoming part of the river catchment environment. We develop a reduced complexity model to capture the transport and deposition of microplastic. By comparing our model to observations from the Têt River, France, we find that large quantities of microplastic must be stored within the river sediments.

The Bohemian Massif is one of several low mountain ranges in Europe that rises more than 1 km above the surrounding lowlands. Landscape characteristics indicate relief rejuvenation due to recent surface uplift. To constrain the pace of relief formation, we determined erosion rates of 20 catchments that range from 22 to 51 m Myr^-1. Correlating these rates with topographic properties reveals that contrasts in bedrock erodibility represent a critical control of landscape evolution.

We try to understand how the sediment supply from the upstream river reach affects the downstream river morphology using a numerical model. If the supplied sediment is composed of a variety of size classes of particles, a small bed wave that is composed of mainly fine particles (sorting wave) can propagate to downstream for a very long distance. However, the presence of bars suppresses the effect of the sorting wave greatly, and thus the sediment supply has a limited role in the downstream river morphology.

This study presents a novel AI-based method for tracking and analysing the movement of rock glaciers and landslides, key landforms in high mountain regions. By utilising time-lapse images, our approach generates detailed velocity data, uncovering movement patterns often missed by traditional methods. This cost-effective tool enhances geohazard monitoring, providing insights into environmental drivers, improving process understanding, and contributing to better safety in alpine areas.

We studied how erosion and tectonic forces can affect the exposure and preservation of copper deposits formed in subduction zones in the past 65 Myr. We used a global model that simulates landscape changes over time based on climate and elevation changes. Our findings show that climate is more important in preserving or exposing copper deposits than previously described. We help improve methods for locating copper deposits, offering new insights for mineral exploration.

Debris flows are fundamental components of the hazard in mountain regions, and numerical models must be used for the related risk computation. Most existing commercial software strongly conceptualizes the main characteristics of the flow, leading to an inevitable calibration process, which is time-consuming and difficult to accomplish. This contribution offers some physically based solutions to confine the calibration process and to better understand the implications of the selected choice.

Leaky wooden dams are a popular form of natural flood management used to slow the flow of water by increasing floodplain connectivity whilst decreasing connectivity along the river profile. By monitoring two leaky wooden dams in North Yorkshire, UK, we present the geomorphological response to their installation, highlighting that the structures significantly increase channel complexity in response to different river flow conditions.

The Armorican region (NW France) is marked by several old coastal and marine markers that are today located several tens of meters above sea level. This fact is commonly explained by sea-level variations and complex tectonic processes (e.g., mantle dynamics). In this study, we test the role of the erosion and the associated flexural (lithospheric bending) response. We show that this simple model of flexural adjustment is to be taken into account to explain the regional evolution.

This paper presents a novel model that predicts how gravel riverbeds may evolve in response to differences in the frequency and severity of flood events. We test our model using a 23-year-long record of river flow and gravel transport from the Swiss Prealps. We find that our model reliably captures yearly patterns in gravel transport in this setting. Our new model is a major advance towards better predictions of river erosion that account for the flood history of a gravel-bed river.

This work presents a protocol and a model to obtain the sizes of the pebbles in mountain rivers from uncrewed aerial vehicle images. A total of 12 rivers located in southeastern France were photographed to build the model. The results show that the model has little error and should be usable for similar rivers. The grain size of mountain rivers is an important parameter for environmental diagnostics by mapping the aquatic habitats and for flood management by estimating the pebble fluxes during floods.

This study reports chemical weathering, physical erosion, and denudation rates from river load data in the Swabian Alb, southwestern Germany. Tributaries to the Neckar River draining to the north show higher rates than tributaries draining to the southeast into the Danube River, causing a retreat of the Swabian Alb escarpment. Observations are discussed in light of anthropogenic impact, lithology, and topography. The data are further compared to other rates over space and time and to global data.

The use of new artificial intelligence (AI) techniques to learn how landscapes evolve is demonstrated. A few “snapshots” of an eroding landscape at different stages of its history provide enough information for AI to ascertain rules governing its evolution. Once the rules are known, predicting landscape evolution is extremely rapid and efficient, providing new tools to understand landscape change.

In many ways, the surface of the planet Mars is similar to that of Earth. However, Mars's lower gravity has an effect on the settling and transport of sediment particles moving in water. Using specific experimental equipment to measure settling velocity aboard a parabolic flight, it was possible to observe how sediments settled in Martian gravity. These experiments served to illustrate that parabolic flights can be used as analogue environments for surface processes on Mars.

We develop a novel approach based on satellite radar images to quantify millimetre-scale sedimentation during monsoon floods over a 15 km stretch of four rivers, from the Himalayan mountain front to the gravel–sand transition. The results show how sediment accumulates more rapidly near the mountain front and decreases downstream, while the floodplain sinks. This method can improve river monitoring, enhance flood prediction, and benefit communities at risk of flooding in Nepal and India. 

At the evocation of icy landscapes, Africa is not the first place that comes to mind. The modern relief of Southern Africa is generally considered to be a result of uplift and counteracting erosion. We show that some of the modern relief of this region is due to fossil glacial landscapes – striated pavements, valleys, and fjords – tied to an ice age that occurred ca. 300 Myr ago. We focus on how these landscapes have escaped being erased for hundreds of millions of years.

The summertime thaw depth of permanently frozen ground (active layer thickness, ALT) is of critical importance for natural hazard management (e.g., rock avalanches) and construction (foundation stability) in mountain permafrost regions. We report the first analytical heat transport model for simulating ALT based on near-surface temperature in permafrost rock walls. Our results show that the ALT will likely increase by more than 50 % by 2050 at 3000 m a.s.l. in the European Alps.

River deltas evolve due to natural forces and human activities, posing challenges for communities relying on stable water flow. This study examines how different flow distributions shape delta channels. Using a new theoretical model, we identify branch length as the key factor influencing stability. Applying this to Italy's Po River Delta, we highlight areas at risk of change, providing insights for better management and planning.

A channel may be aggraded by overloaded sediment. In this study we realize an aggradation experiment and determine the celerity at which an aggradation wave, due to sediment overloading, migrates. We also investigate the celerity of small perturbations, as quantified by mathematical formulations. The celerities of the two kinds are correlated with each other. However, the celerity of small perturbations is larger than the other one, which is less than a few percent of the water velocity.