Physics-based morphodynamic modeling is essential for advancing river management science and understanding Earth's geomorphological evolution processes. However, their computational demands and long processing times hinder long-term applications. This paper introduces and tests a robust Deep Learning (DL) framework that opens the door to overcoming these challenges through integrating convolutional neural networks (CNNs) with long short-term memory (LSTM) architectures, trained using outputs from the physics-based HEC-RAS model. This framework facilitates rapid and continuous spatiotemporal predictions of hydrodynamic parameters and morphodynamic responses of flood events. Hydrodynamic predictions showed strong performance across the testing dataset, with mean RMSEs of 0.15 m and 0.04 m s−1R2
Wave-abrasion terraces are geomorphic marker horizons that provide information of past water levels, in marine and lacustrine environments. By integrating elevation measurements and age constraints, they serve as strain markers to assess vertical deformation rates associated with tectonic and/or climatic processes. As most geomorphic markers, wave-abrasion terraces are ephemeral features, and their topographic signature has variable levels of noise. Therefore, accurate and precise estimates of marine terrace morphology are essential to obtain significant uplift/subsidence rates. The open source TerraceM-3 enables operators to reduce non-systematic and systematic errors in terrace mapping by integrating machine learning techniques to replicate human mapping criteria, and standardized and reproducible workflows to handle systematic errors. In many regions, the availability of high-resolution topographic data remains relatively scarce limiting precision in geomorphic marker mapping. TerraceM-3 introduces a new module for downloading, filtering, and processing centimeter-resolution topographic data from the ICESat-2 satellite at global scale. The TerraceM-ICESat module produces vegetation-free profiles ready for assisted machine-learning mapping into a graphical user interface. Shallow bathymetry may be also extracted to extend the mapping of drowned terraces offshore. The new functionalities of TerraceM-3 were tested along tectonically active coasts in Peru and Algeria, revealing detailed deformation histories controlled by subducted seamounts and crustal faults. TerraceM-3 is designed to support research in tectonic geomorphology and paleoclimate studies by enhancing the precision and accuracy of wave-abrasion terrace mapping with applications in the assessment of coastal hazards.
Asymmetric tidal dunes with intermediate (10–17°) to low-angle slopes (< 10°), usually with an irregularly-shaped lee side, are often found in natural, constrained tidal environments such as tidal rivers, estuaries and tidal channels. However, previous studies on bedform flow dynamics have largely focused on high-angle dunes with a simple (straight) lee side, generally found in flume studies or small rivers. This study provides a detailed characterisation of the flow and turbulence over asymmetric tidal dunes under an idealised tidal flow condition based on laboratory measurements. Specifically, we aim to address how tidal dune shape, especially the lee side geometry, controls the properties of flow separation and resulting turbulence structures. Furthermore, we address how flow bidirectionality changes flow and turbulence over the same tidal dune geometry. To achieve this, we conducted large-scale, high-resolution flume experiments over two idealised dune morphologies which represent natural asymmetric tidal dunes with intermediate- to low-angle slopes. The flow condition was an idealised representation of tidal flow for which the same unidirectional steady currents were imposed first in one direction, then in the opposite direction. Our results show that for the case of an intermediate-angle tidal dune and when the flow was directed from the gentle stoss to the steep lee slope, a downward expanding turbulent wake and a small, near-bed permanent flow separation were detected. A small flow separation was also detected for the case of low-angle tidal dune. When the flow was reversed and directed from the steep stoss to the gentle lee slope, flow direction significantly altered the flow dynamics for both dunes as no permanent flow separation was observed and turbulence structure was similar to that over a flat bed. Interestingly, we demonstrated that a small intermittent flow separation can still form even for tidal dunes with very gentle slope (4°) provided that a short steep portion is present. This implies that low-angle dunes can generate flow resistance and can potentially contribute to sediment mobilisation above low-angle dunes. Overall, our study highlights the significant impact of dune morphology, particularly the lee side slopes, and flow direction on the flow and turbulence dynamics above asymmetric tidal dunes. Our findings can have further implications on the parameterisation of hydraulic roughness, estimation of sediment transport and the resulting morphodynamics in natural shallow water environments.
Bedrock river incision is a fundamental process driving the evolution of mountainous landscapes. Bedrock strength is often considered a primary control on incision rates and river profile morphology, with laboratory experiments showing a strong correlation between erosion rate and tensile strength. However, in natural settings, lithological boundaries frequently do not correspond to changes in the channel gradient. This study addresses this apparent paradox by integrating field observations with numerical experiments in the tributaries of the Abukuma River basin, northeastern Japan. Field surveys were conducted to measure bedrock tensile strength, riverbed gravel grain size, and the spatial distribution of lithologies. Despite more than an order-of-magnitude variation in bedrock tensile strength across the study area, the channel slopes remained nearly uniform. Numerical experiments were performed using three models of bedrock river erosion to investigate the underlying mechanisms. Among them, the sediment-flux-dependent model, which explicitly incorporates sediment cover and tool effects, most accurately reproduced the observed longitudinal profiles. The results reveal that the local lithology does not directly influence channel slope due to a negative feedback between sediment cover and river gradient. Higher bedrock erodibility reduces channel slope and sediment transport capacity, promoting sediment cover. The resulting sediment cover suppresses further erosion and offsets the effect of bedrock strength. These findings highlight the limited role of bedrock strength in controlling channel gradients and underscore the importance of sediment dynamics, particularly sediment supply and grain size, in shaping fluvial topography. Future research should explore how lithology-dependent variations in sediment characteristics influence river profile development.
The Normalized Difference Vegetation Index (NDVI) can be effectively used for monitoring the spatial and temporal dynamics of riparian vegetation. However, quantitative and efficient evaluations of the links between NDVI and bio-hydromorphological processes remain limited, particularly in river management contexts where dense in-channel vegetation can obstruct flow and reduce conveyance capacity. Using 200 cloud-free Sentinel-2 images (2015–2024) covering a 20-km reach of the Chikuma River (Japan), we evaluated the utility of high temporal resolution NDVI and greenness index (defined as NDVI > 0.2) as quantitative indicators of bio-hydromorphological dynamics and its implications for riverine management. The analysis focused on the relationships between NDVI dynamics, flood magnitude, relative elevation along lateral channel morphology, and seasonal vegetation variability within a frequently disturbed channel. The results show that NDVI fluctuations strongly correspond to flood disturbances at lower relative elevations, whereas vegetation at higher elevations remains relatively stable. The annual maximum greenness ratio was well described by a logistic model along the cross-sectional transects. Annual greenness ratio exhibited clear seasonal patterns, showing a late-summer (August–September) greenness peak. These spatiotemporal and seasonal NDVI characteristics demonstrate the potential of Sentinel-2 imagery to operationalize both the “when” (timing) of vegetation management and the “where” (priority zones defined by relative elevation), providing a transferable, remotely sensed basis for flood-risk mitigation in frequently disturbed riverine environments.
Recent recognition of a new type of fluvial system – fluvial fans – introduces a fan-shaped channel network that appears similar to that of river-dominated deltas. Deltas form where rivers enter lakes and oceans, while fluvial fans are terrestrial landforms. However, fluvial fans can reach the shorelines of oceans or lakes, and in such cases the distinction between fluvial fan and river-dominated delta channel networks becomes ambiguous. We currently lack fundamental understanding of these two landforms' morphometric differences, despite their high socioeconomic significance, vulnerability to natural hazards, and key differences in how these landforms respond to global climate change and urbanization. Here we review the relevant conceptual differences in delta and fluvial fan network morphodynamics, propose a set of quantitative morphometric criteria to distinguish fluvial fan and delta channel networks, and test these criteria on 40 deltas and 40 fluvial fans from across the world. This initial attempt to contrast and distinguish deltas and fluvial fans based on their channel network morphometrics demonstrates that quantifying channel network angles (mean of 74.0° for deltas and 55.0° for fluvial fans) and trends in normalized channel widths and lengths provide efficient criteria, but some ambiguities remain that need to be resolved in future work. This research advances our mechanistic understanding of fluvial fan and delta channel networks and the recognition of modern and ancient landforms on Earth and other planetary bodies, such as Mars and Saturn's moon Titan.
River erosion is a fundamental process that impacts, among others, mountain landscape evolution. Mountain rock lithologies often exhibit bedding, joints, and fractures that are thought to alter the incision efficiency of rivers compared to intact, massive rocks. The presence of close enough planar mechanical discontinuities allows the creation and entrainment of large blocks through plucking, a process that adds to abrasion, and potentially macroabrasion, by the transported sediment. Despite preliminary attempts to include shallow fracturing in theoretical models of bedrock incision and a couple of studies that quantified the relative importance of abrasion and plucking processes in situ, we are still lacking ways to systematically probe the role of fractures on bedrock erosion rates and processes. Due to the complex interactions at play, here we investigate this question via an experimental approach, using a new erosion mill designed to erode a fractured concrete disk with a diameter of 17 cm. We simulate vertical or dipping fractures by embedding a 3D-printed plastic mesh in the concrete, using BVOH – a plastic that softens in cold water – creating mechanical weaknesses with a controlled pattern. We explore 10 different geometries and run 4 additional experiments without fractures for control. We record the topographic evolution every 2 min by photogrammetry and derive erosion maps by measuring elevation changes between successive scans. Our results show that fractures influence the morphodynamical evolution of the disks and the relative contributions of abrasion and plucking. However, abrasion systematically remains the dominant erosion mechanism, with plucking contributing at most to 29 % of the total erosion for vertical fractures spaced by 20×20 mm2, 40 % for one specific dip angle (67°), and less than 10 % for most experiments. Average erosion rates show a modest (20 %) increase with the fraction of plucking, but do not show a clear relationship with fracture density and the presence of fractures. We suggest that the rate of erosion by plucking is limited by the depth and slow rate of horizontal fracture propagation between pre-existing vertical fractures, such that in our experimental setup, abrasion is systematically a dominant component. These findings emphasize the critical role of block preparation and loosening for plucking to be an effective process compared to abrasion. This new setup allows abrasion, macroabrasion, and plucking driven by bedload impacts to be studied in controlled situations, albeit with the well-known limits of abrasion mills and without the variety of natural processes that can drive fracture propagation. Further experiments should expand the parameter space of the erosion efficiency problem (i.e., sediment mass, grain size, flow velocity, intact rock mass strength, 3D fracture patterns) to help in developing mechanistic models applicable in natural environments.
The Outdoor Experimental River Facility (OERF) is a new large-scale, semi-natural research facility designed to study river dynamics at scales that bridge small laboratory models and natural rivers. The facility comprises a 50 m long, 20 m wide floodplain corridor and is designed to sustain discharges up to 800 L s−1, allowing subcritical, fully rough flow with field-like Reynolds numbers approaching 105h∼ 14 d) straight-channel run without upstream sediment supply, a bi-modal gravel–sand bed (initial median diameter = 10 mm) progressively armoured to ∼ 22 mm, and reach-scale planform change remained modest despite a width-to-depth ratio of 12 and near-threshold mobility. A three-phase, mathematically designed inlet bar–pool perturbation increased local velocities by 8 %–27 % and produced limited lateral bank erosion (∼ 2.5–7.5 cm). The results delineate a narrow operational window for sustained bar growth and migration, long adjustment times, practical constraints of outdoor operation, and the moderating role of bank-material strength and toe armouring. Together, these findings show that field-like hydraulics are achievable within the facility while clarifying what limits mobility at this scale, and they motivate future experiments that couple hydrodynamic similarity with controlled sediment recirculation/feed and refined boundary controls to advance understanding of controls on bank erosion and planform evolution.
Duricrusts form near the top of or within the regolith. Once exhumed, they are resistant to erosion and are often observed capping hilltops. Two hypotheses have been proposed to explain their formation. One calls upon seasonal fluctuations in water table height causing cycles of dissolution and precipitation that concentrate hardening species transported from distant sources. The other assumes that hardening is the ultimate phase of laterisation of the regolith by progressive leaching of the soluble elements that leads to in situ concentration of the hardening species. Here we propose a numerical model for the formation of duricrusts following the latter hypothesis, which we will term the in situ or laterisation (LAT) model. In Fenske et al.2025), we developed a similar model representing the other model (named here the transport or Water Table Fluctuation (WTF) model).The LAT model we present here assumes that the rate of hardening is a self-limiting process that takes place at a rate determined by a laterisation time scale, τl, and is linearly proportional to precipitation rate. Laterisation is accompanied by mass loss, at a rate set by a mass loss time scale, τm, that can potentially be different from τl(Braun et al., 2016).Here we present results obtained from the new LAT model by varying both the model parameters and the external forcing functions, namely, UP, the precipitation rate. We show that duricrust formation by laterisation is favored by a small uplift rate as well as a strong precipitation rate. The smaller the laterisation time scale and the mass loss time scale, the thicker the duricrust, but if the ratio between the two time scales, τm 
This study investigates spatial and temporal variability of bedload transport in four Swiss mountain streams using continuous Swiss Plate Geophone (SPG) monitoring. This surrogate measuring system had been calibrated in previous studies to produce reliable estimates of bedload transport rates. The measurements were analysed at two different time scales: short-term transport events typically covering a duration of a few weeks and multi-year annual transport totals. Power-law relations between dimensionless transport intensity and shear stress were derived to evaluate the temporal variability in the steepness of transport relations and in the reference shear stress. Results were compared with predictive equations developed for mountain streams. Findings show substantial variability both within and across sites, likely reflecting the influence of sediment availability, stream slope, streambed texture and flow history. Overall, continuous monitoring highlights the strong role of temporal spatial variability on bedload transport levels, possibly due to changing sediment availability and bed surface composition, and with implications for predictive modelling and river management.
The grain sizes of sediments in channels have been linked to landscape characteristics, such as flow distance from headwaters, topographic relief, lithology and climate, in landscapes with little past or present glacial influence. Few studies have explored the controls on sediment characteristics in formerly glaciated landscapes. In this study, we document river surface grain sizes at 279 localities across Scotland. We collect photographs of gravel bars through a citizen science survey, Scotland's Big Sediment Survey. Grain sizes distributions are extracted from the photographs using both manual and automated techniques. We investigate whether grain sizes can be correlated and predicted from environmental variables (e.g., basin slope, flow distance from headwaters) through Spearman's correlation statistics and random forest regression modelling. In contrast to other studies that have primarily focused on non-glaciated landscapes, we find no apparent controls on surface grain sizes in channels across Scotland. Specifically, we find no significant Spearman's relationships between d84 and environmental variables; the strongest relationship was found between d84 and average basin aridity with a weak r2
Geomorphologists have more data and computational resources available than ever before. Collaboration between researchers specializing in different modes of inquiry (e.g. numerical, experimental, and field-based) often accelerates impactful scientific insights, but tools to facilitate these collaborations are lacking. In this article, we present four challenges to collaboration in the geomorphology community, and provide a framework that addresses these challenges to enable research utilizing the full extent of data and computational resources available today. We report a component of this framework, a newly developed specification for a shareable data schema called sandsuet. The schema is designed to accommodate most kinds of rasterized geomorphology data, and makes it easy to package, publish, and share those data. Finally, we present possibilities for community development of resources to address other challenges to collaboration in geomorphology.
Using grain-resolved LES-DEM simulations, Zhang et al. (2025) aimed to validate a grain-shape-corrected bedload transport equation proposed earlier by the same group. It states that grain shape effects are captured through a modified Shields number that depends, among others, on the drag coefficient,
The predictive capacity for rockfall has significantly increased in the last decades, but complementary combinations of observation methods accounting for the wide range of processes preparing and triggering rockfall are still challenging, especially at sensitive sites like World Heritage monuments. In this study, we combine Terrestrial Laser Scanning (TLS), Interferometric Synthetic Aperture Radar (InSAR), ambient vibration analyses, and rockfall runout modelling at the 3500-year-old Mortuary Temple of Hatshepsut, a key World Cultural Heritage Site and among the best-preserved temples in Ancient Thebes, Egypt. The temple is exposed to a 100 m vertical, layered, Eocene Thebes Limestone cliff. Here, a major historic rock slope failure buried the neighbouring temple of Thutmose III, and behind the temple frequent fragmental rockfall occurs. The project “High-Energy Rockfall ImpacT Anticipation in a German-Egyptian cooperation (HERITAGE)” aims to combine TLS and InSAR to constrain pre-failure deformation, potential detachment scenarios, and rockfall runout modelling for singular blocks and granular flows from rock tower collapses towards an integrative analysis. Based on TLS and InSAR, we could measure volumes of small failures between 2022–2023 and map potential detachment zones of interest for larger failures. Only the combination of InSAR and TLS can unequivocally delineate rockfall-active areas without the ambiguity of single techniques. Based on this, we modelled the runout of small single-block failures of the observed size spectrum (0.01–25 m3) and constrained frictional parameters for large (i.e. > 103 m3) granular flows from collapsing towers using historic failures. The applicability of ambient vibration analysis to detect preparatory destabilisation of rock towers prior to deformation by frequency shifts is successfully tested. This study shows the potential of combining non-invasive rockfall observation and modelling techniques for various magnitudes towards an integrative observation approach for cultural heritage such as Egyptian World Heritage Sites. We demonstrate the capabilities of our integrated approach in a challenging hyper-arid climatic, geomorphological and archaeologically sensitive environment, and produce the first event and impact analysis of gravitational mass movements at the Temple of Hatshepsut, providing vital data for future risk assessments.
Quantifying erosion across spatial and temporal scales is essential for assessing different controlling mechanisms and their contribution to long-term sediment production. However, the episodic supply of material through landsliding complicates quantifying the impact of the individual erosional mechanisms at the catchment scale. To address this, we combine the results of geomorphic mapping with measurements of cosmogenic 10Be, 26Al, and 14C concentrations in detrital quartz. The sediments were collected in a dense network of nested sub-catchments within the 12 km2-large Gürbe basin that is situated at the northern margin of the Central European Alps of Switzerland. The goal is to quantify the denudation rates, disentangle the contributions of the different erosional mechanisms (landsliding versus overland flow erosion) to the sedimentary budget of the study basin, and to trace the sedimentary material from source to sink. In the Gürbe basin, spatial erosion patterns derived from 10Be and 26Al concentrations indicate two distinct zones: the headwater zone with moderately steep hillslopes dominated by overland flow erosion, with high nuclide concentrations and low denudation rates (∼ 0.1 mm yr−1), and the steeper lower zone shaped by deep-seated landslides. Here lower concentrations correspond to higher denudation rates (up to 0.3 mm yr−1). In addition, 26Al 
Viscous flow features known as glacier-like forms on Mars have been observed emerging from alcoves that resemble cirques on Earth. However, many alcoves exist without associated glacier-like forms, and these features have never been studied or categorized at a regional population scale. On Earth, cirques form when depressions on mountain slopes accumulate snow, which gradually compacts into glacial ice. As the glacier flows downhill, it deepens the depression through erosion. Most of this erosion is driven by wet-based glaciers, although cold-based glaciers can also contribute to some headward and sidewall retreat. Here, we present evidence that cirque-like alcoves on Mars, similar to terrestrial cirques, are shaped by glacial erosion. To assess which alcoves on Mars are most “cirque-like”, we mapped a regional population of ∼ 2000 alcoves in Deuteronilus Mensae (40–48° N, 16–35° E), a region in the mid-latitudes of Mars characterized by mesas surrounded by glacial remnants. Based on visual characteristics and morphometrics, we refined our dataset to 434 “cirque-like alcoves” – nearly six times the amount of glacier-like forms in the region – and used this to better understand the potential contribution of glaciation to landscape evolution in Deuteronilus Mensae, Mars. High-resolution imagery reveals geomorphic evidence for past glacial occupation of these cirque-like alcoves, including flow features, linear terrain, moraine-like ridges, mound-and-tail terrain, polygonal terrain, rectilinear-ridge terrain, and washboard terrain, as well as an ice-rich mantling unit. Most cirque-like alcoves face south to southeast, similar to gullies poleward of 40°. One possibility to explain this trend is that southward facing cirque-like alcoves in the northern mid-latitudes formed when conditions were more favorable for ice accumulation during periods of high obliquity. Using wet-based glacial erosion rates, assuming a mean annual temperature of 0 °C (compared to present-day temperatures of
Values representing grain size distributions of stream reaches are essential for estimating sediment transport at the reach scale. Various modeling frameworks exist that attempt to simulate reach-scale sediment transport across entire drainage basins to characterize sediment dynamics at a watershed scale. Such frameworks require estimates of grain size at each reach. Because obtaining direct measurements at this scale is impractical and logistically difficult, methods to estimate or extrapolate grain size measurements are needed, however, few currently exist. Here I present an extrapolation algorithm that uses one or more pebble counts to extrapolate full grain size distributions to each reach of a drainage network. In addition to the pebble count measurements, the tool requires a stream network geospatial feature class, attributed with values for reach-averaged slope and some consistent measure of relative flow magnitude (or a proxy for flow). I tested the tool in a set of sub-watersheds in the Bitterroot River basin of western Montana, US, with varying valley morphologies, and compared predictions to measurements at 16 sites. When using multiple measurements for calibration, mean absolute percent error averaged 5.8 % of the measured grain sizes in the phi scale. When using a single measurement for calibration, error averaged 8.4 %.
Periglacial debris flows in alpine mountains are influenced by strong earthquakes or climatic warming and play a crucial role in delivering sediment from hillslopes and downslope channels into rivers. Rapid and massive sediment supply to rivers by the debris flows has profoundly influenced the evolution of the alpine landscape. Nonetheless, there is a dearth of knowledge concerning the roles tectonic and climatic factors played in the intensified sediment erosion and transport. In order to increase our awareness of the mass wasting processes and glacier changes, five debris flows that occurred at the Zelunglung catchment of the eastern Himalayan syntaxis since the 1950 Assam earthquake were investigated in detail by field surveys and long-term remote sensing interpretation. Long-term seismic and meteorological data indicate that the four events of 1950–1984 were the legacies of the earthquake, and recent warming events drove the 2020 event. The transported sediment volume indexed with a non-vegetated area on the alluvial fan has reduced by 91 % to a stable low level nearly 40 years after 1950. It is reasonable to hypothesize that tectonic and climatic factors alternately drive the sediment supplies caused by the debris flows. High concentrations of coarse grains, intense erosion, and extreme impact force of the 2020 debris flow raised concerns about the impacts of such excess sediment inputs on the downstream river evolution and infrastructure safety. In regard to the hydrometeorological conditions of the main river, the time to evacuate the transported coarse sediments is approximately 2 orders of magnitude longer than the recurrence period of periglacial debris flows.
We simulate landscape evolution using a diffusion-advection equation with a source term, where the advection velocity is derived from the classical parametrization of the Stream Power Law. This formulation allows for forward modeling of uplift, hillslope and fluvial erosion within a finite-element framework, and enables the use of adjoint methods for sensitivity analysis and parameter inversion. When considered individually, model parameters such as the diffusion coefficient, fluvial erodibility, initial topography, and time-dependent uplift can be inverted using constraints from final topography, sediment flux, or cumulative denudation at specific locations. Sensitivity analysis on a real landscape reveals that sensitivity to erosion parameters is higher in steep, high-relief areas and that hillslope diffusion and fluvial incision affect the model differently. After a series of tests on synthetic topographies, we apply the adjoint model to two natural cases: (1) reconstructing the pre-incision topography of the southeastern French Massif Central, which appears as a smooth, flat footwall bounded by a linear escarpment along a major lithological boundary; and (2) estimating the Quaternary uplift rate along the Wasatch Range, USA, where our model suggests a significant increase in uplift from 0.2 to 1 mm yr−1∼ 2 million years.
Modelling sediment transport is important to understand how fluvial systems respond to climatic change or other transient conditions such as catastrophic sediment release. In natural rivers, heterogeneity of sediment properties and variability of the flow regime result in different modes of transport that all contribute to the total sediment load. Le Minor et al. (2022) presented a sediment transport law for rivers that extends from bed load to suspended load while being relevant for a wide range of grain sizes but not specifically addressing the case of a distribution of grain sizes, which must also consider the interactions between grain classes that are mainly important during the sediment erosion phase. If these interactions are not properly considered, the model overestimates transport rates compared to measured ones. We present a new formalism for the reference shear stress of multiple-size sediments, a parameter governing the onset of transport. We show that using a reference shear stress standardized across datasets improves transport rate predictions made with the model of Le Minor et al. (2022). We show that considering the bed roughness length as a reference transport height for single- and multiple-size sediments significantly improves transport rate predictions. We also suggest that, for multiple-size sediments where the bed surface is not fully mobile, the entrainment coefficient should include a dependency on the fraction of mobile grain sizes at the bed surface, although data are insufficient to add this effect in a definite parameterization. Therefore, a standardized reference shear stress and a transport length adjusted with a common reference height across all sizes appear to be two critical ingredients of a fully functional multi-grain-size total sediment load model based on the disequilibrium length. This adjusted model offers the potential to quantify grain-size-specific sediment fluxes when different modes of transport may be observed simultaneously, paving the way for more informed numerical modelling of fluvial morphodynamics and sediment transfers.