Critical infrastructure, including bridges, dams, levees, flow regulation and river training structures, is inevitably related to the morphodynamics of rivers, estuaries, and coastal areas. While large-scale morphological changes are widely recognized, they are primarily driven by local processes such as flow variability, turbulent structures, sediment entrainment, and continuous water-bed interactions. When infrastructure is introduced into dynamic water environments, it often leads to significant and frequently unintended morphological consequences. Understanding these drivers and responses, including infrastructure-related disturbances, is essential for sustainable water management, risk reduction, and long-term resilience in the context of climate change.
This session explores river response to disturbances of all scales throughout time and space. We welcome field-based research, numerical modeling, theoretical approaches, physical experimentation, and hybrid approaches. We particularly encourage contributions on:
• River management and restoration approaches that utilize geomorphic processes and geomorphic history
• Impacts of built and hybrid structures on flow, sediment transport, and morphology
• Flow-structure interactions and morphodynamic responses to infrastructure under changing conditions
• Advances in remote sensing, monitoring, and AI-based modeling for morphology quantification
• Climate change adaptation, resilience, and risk management in riverine, estuarine, and coastal environments
Orals: Tue, 5 May, 14:00–15:45 | Room G1
Large braided rivers pose persistent challenges for the protection of major river training works, as rapid channel migration, evolving char formations, and highly localized scour can compromise structures within short timescales. The Jamuna River in Bangladesh is one of the most morphodynamically active systems of this kind, making it an ideal but demanding environment for operational forecasting and adaptive management.
Since 2014, a morphological model of the Jamuna River has been progressively developed using detailed survey data and MIKE 21C simulations. This model underpins annual monsoon-season morphological forecasts, predicting planform adjustments and potential scour depths for the upcoming monsoon. The 2025 forecast report which was submitted on 30 April, identified elevated scour risk between CH 1300–2500, with maximum predicted depths ranging from -31.51 mPWD under a 1 in 100 year flood to -37.16 mPWD under a 1-in-2.33-year flood. These predictions guided initial preparedness and monitoring plans for the monsoon season.
In recent years, the framework has been extended to provide near-real-time scour forecasts for all major river training works, integrating short-term hydrological forecasts with high-frequency bathymetric observations. During the 2025 monsoon, the near-real-time hydro-morphodynamic modelling system was continuously updated using the latest 5-day water level forecasts from the Flood Forecasting and Warning Centre (FFWC) and validated through frequent single-beam and multibeam bathymetry surveys. This approach enabled timely detection of rapid scour intensification near CH 2600-2700. Based on combined survey and model results for August, a targeted dumping plan along CH 2470-2780 was formulated and executed. This represents an adaptive intervention strategy, where protective measures are triggered in response to evolving river dynamics indicated by both predictive simulations and real-time observations. By late August, measured scour reached -33.34 mPWD exceeding the design threshold by more than 6 m. Yet timely adaptive interventions maintained apron stability and prevented wider structural exposure.
This study demonstrates that operational morphodynamic forecasting integrating annual monsoon-season predictions with near real time model updates and survey observations, can significantly enhance the resilience of major river training works in highly dynamic sand bed rivers. It represents one of the first operational applications of an integrated multi-horizon and near real time morphodynamic forecasting framework for guiding adaptive river training interventions providing a practical and scalable blueprint for infrastructure risk management under increasing hydrological variability and climate-driven extremes.
How to cite: Khan, I., Billah, M., Salim, M. A., Musfequzzaman, M., Saadat, M. A., and Jahan, S.: A Multi-Horizon Morphodynamic Forecasting and Near Real-Time Scour Monitoring Framework for the Jamuna River, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-402, https://doi.org/10.5194/egusphere-egu26-402, 2026.
Unregulated sand mining has become a major global sustainability challenge, yet managers still lack clear tools to determine where sand can be extracted and how much can be removed without damaging river systems. This study presents a new, practical framework called Sustainable Mining Zones (SMZ) that combines high-resolution sediment mapping with ecological and geomorphic sensitivity analysis to support science-based sand mining decisions. The Vietnamese Mekong Delta, one of the world’s most intensively mined river systems, is used as a test case. Using a high-resolution Delft3D-FM model initialized with a 2017 riverbed survey and validated against 2020 observations, we simulated hydrodynamics, sediment transport, salinity intrusion, and riverbed evolution from 2017–2021. Results indicate a cumulative sediment loss of approximately 250 Mm³, with severe reach-scale deficits reaching ~−79.5 Mm³ yr⁻¹ in the Tien River and a median incision rate of ~0.30 m yr⁻¹, strongly coinciding with observed dredging hotspots. Although the delta contains substantial sediment resources (~10.59 Bm³ above a conservative thickness threshold), sustainability screening reduces the effective resource to ~4.91 Bm³ once geomorphic stability and ecological constraints are applied through the Suitability-Weighted Reserve (SWR). Scenario simulations show that an equilibrium extraction benchmark of approximately ~4.9 Mm³ per year produces minimal morphological impact, while a practical upper operational limit of about 9.8-9.9 Mm³ per year can meet moderate construction demand if extraction is confined to high-suitability mid-channel and point-bar zones. The SMZ framework provides a transferable, map-based tool for regulators to balance development needs with long-term river resilience in sediment-stressed river basins worldwide.
Keywords: Sand mining; Mekong Delta; sediment dynamics; sustainable management; river morphology; decision support
How to cite: Kumar, S., Park, E., Tran, D. D., and Switzer, A. D.: Sustainable Mining Zones: A Multi-Criteria Framework for Balancing Sand Extraction and River Integrity in the Mekong Delta, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-2077, https://doi.org/10.5194/egusphere-egu26-2077, 2026.
Large-scale infrastructure represents one of the most pervasive anthropogenic disturbances to fluvial systems, yet the cascading interactions between reservoir operations and alpine land-surface processes remain elusive. This study targets the Lancang–Mekong River Basin, a critical transboundary hotspot originating from the Qinghai-Tibet Plateau, to quantify how hydrological regulation mediates the coupling between local microclimates and vegetation phenology (including the start of the growing season (SOS) and the end of the growing season (EOS)). We developed an analytical framework integrating long-term multi-source remote sensing observations with structural equation modeling and interpretable machine learning to disentangle the cumulative, spatially heterogeneous responses to damming. Our results reveal a fundamental regime shift: over the past 24 years, the vegetation growing season in dam-concentrated reaches has extended by over 30 days, characterized by a 22-day advance in SOS and a 9-day delay in EOS. While natural climatic drivers typically dominate alpine phenology, reservoir-induced impoundment has perturbed the local hydrothermal equilibrium and alleviated water stress in dry-hot valleys. Attribution analysis reveals that reservoir-regulated soil moisture dynamics account for 42.7% of vegetation variability, representing a mechanistic transition from climatic dominance to a coupled human-environment regulation regime. This mechanistic shift provides essential geomorphic and eco-hydrological insights for the adaptive management and ecological restoration of disturbed river systems in high-altitude hotspots.
How to cite: Zhang, Y., Xu, M., Zhang, Y., and Xue, Y.: Vegetation Phenology Shifts Driven by Cascade Reservoir Operations in the Lancang–Mekong River Basin, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-2171, https://doi.org/10.5194/egusphere-egu26-2171, 2026.
Water resources are being heavily affected by armed conflicts, which worldwide have greatly increased in numbers. Rivers and floodplains are used as frontlines, while waters of reservoirs as weapons of war. Military actions on the territory of Ukraine have unprecedent effects on freshwaters and water infrastructure of the country caused by pollution, physical damage and placing of mines along river courses. Since 2022, several dams were destroyed along the Irpen, Oskil, and Inhulets rivers. The most dramatic, however, was a collapse of the Kakhovka dam on the Dnieper river on the 6th of June 2023. This war-induced dam destruction caused drainage of one of the Europe’s largest reservoirs, resulting in catastrophic flooding and pollution of the river, estuarine and Black Sea environments. Understanding impacts of such dam destructions during the war time is challenging due to restricted access to affected territories and limited field assessments.
Here I will introduce an innovative framework to assess short and long-term environmental and human-health related impacts of sudden dam destructions using the case of the Kakhovka Dam. Our framework combines results of pre- and post-destruction field surveys, numerical modelling and remote-sensing to outline spatial-temporal scales of the disaster and predicts trends in re-establishment of altered ecosystems. We highlight previously overlooked risks imposed by accumulations of heavy metals in exposed sediments of the former reservoir. Assessment of scenarios to mitigate the pollution and possible solutions are provided. Sudden dam destructions caused by warfare or extreme weather events can be well assessed by our framework, to effectively mitigate risks posed by aging dams around the world.
How to cite: Shumilova, O.: Understanding impacts of military dam destructions on river ecosystems: the case of Ukraine, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-10142, https://doi.org/10.5194/egusphere-egu26-10142, 2026.
River management and restoration increasingly aim to create resilient rivers capable of adjusting to future environmental uncertainty. However, centuries of channel modification and floodplain disconnection have severely reduced river resilience. Valley-floor reset is a novel restoration approach that involves infilling existing channels and regrading the floodplain to re-establish hydrogeomorphic processes across the valley floor. By effectively resetting river–floodplain morphology, this approach is hypothesised to restore the capacity of rivers to evolve and adapt to changing input drivers. This study investigates the geomorphic and hydrologic responses of rivers to valley-floor reset restoration, focusing on the River Aller (UK), one of the first valley-floor reset restoration schemes implemented in Europe. Restoration transformed an incised, single-thread river into a wide, multi-thread river–wetland corridor by reconnecting channels to floodplains at low flows. Water storage increased by 1,156%, while the water table elevation rose across the valley floor by an average of 0.8 m. Subsequent geomorphic evolution has included channel development and sediment sorting, creating a mosaic of river and wetland habitats. The results demonstrate that reconnecting rivers to their floodplains at low flows can fundamentally alter the functioning of heavily modified rivers, shifting them from efficient linear drainage systems to laterally connected river-wetlandscapes, and offering a promising strategy for adapting rivers to a changing climate.
How to cite: Mason, R.: Adapting rivers to a changing world: Can restoration ‘reset’ riverscapes and increase resilience?, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-21427, https://doi.org/10.5194/egusphere-egu26-21427, 2026.
Rivers across the world are responding to natural and anthropogenic disturbances including post-glacial landscape evolution, land-use changes, and climate change. Beaver Dam Analogs (BDAs) have emerged as a low-tech, process-based restoration tool designed to mimic the geomorphic and hydrological functions of natural beaver dams and increase water retention, sediment storage, flood attenuation, and habitat creation. Despite the adoption of BDAs in selective areas in North America uncertainties remain regarding their effect on fish habitat and potential flood risks under failure scenarios. These uncertainties continue to constrain permitting, implementation, and acceptance of BDAs as a widely accepted restoration method. This research integrates machine learning, field observations, and controlled physical experimentation to evaluate how BDAs influence fluvial processes across spatial and temporal scales. A province-wide habitat suitability model is being developed using satellite imagery, environmental variables, and a database of mapped beaver dam locations. This model identifies stream conditions most conducive to successful BDA implementation and highlights areas where environmental characterstics may limit suitability. Second, controlled experiments in the University of British Columbia’s river flume laboratory test how variations in BDA design affect channel morphology, sediment transport, and flow dynamics. These experiments simulate incised channel conditions typical of many degraded systems and quantify geomorphic responses under varying discharge regimes and dam configurations. Third, field data from ongoing restoration projects combined with flume-derived relationships will inform the development of a flood risk model. This component assesses hydraulic impacts and potential dam failure scenarios, addressing key management concerns related to downstream infrastructure and fish passage. The results will directly support the British Columbia Wildlife Federation, and the Lheidli T’enneh First Nation in refining restoration strategies and developing evidence-based guidelines for BDA design and implementation.
How to cite: Matechuk, L.: Evaluating Geomorphic and Hydrological Responses to Beaver Dam Analogs: Integrating Machine Learning, Field Data, and Flume Experiments to Inform River Restoration, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-265, https://doi.org/10.5194/egusphere-egu26-265, 2026.
Large wood (LW) has become an essential tool in river restoration due to its ability to enhance habitat heterogeneity and restore natural processes disrupted by human activities such as channelisation. This work presents findings from 2-year field monitoring across 4 restoration sites in the UK, aimed at quantifying the effects of various LW interventions on geomorphic changes and hydraulic complexity.
The sites including in our monitoring have been selected for the diverse type of interventions, catchment type (ranging from stream orders 3rd to 6th), and LW complexity that has been used for restoration, for example, Stage-0 (Holnicote, Somerset, UK and Tattiscombe, Devon, UK), complex dams and deflectors (Magdalen Farm, Somerset, UK), simple deflectors (Mosterton, Somerset). The monitoring process encompassed the quantification of surface velocity variations around LW installations through a drone-based large scale particle image velocimetry (LSPIV) method coupled with the structural complexity and type of LW, and measurement of LW-induced geomorphic changes using high-resolution RTK drone surveys and walk-overs using Leica GNSS unite. To identify the impact of LW on restoration, we employed a control (unwooded) versus impact (restored) design for Magdalen and Mosterton farms combined with a before‑and‑after monitoring approach for Holnicote and Tattiscombe.
For the first objective, LSPIV was employed to acquire spatially continuous velocity fields across selected rivers reaches within the sites, mitigating the methodological limitations of traditional point-measurement techniques near complex LW structures. LSPIV surveys were conducted during contrasting low (Q90-Q99) and high (Q10-Q4) flow conditions at intervention and upstream control reaches. Velocity analyses quantified spatial heterogeneity using coefficient of variation in velocity, revealing consistent formation of distinct wake zones (reduced velocity) and acceleration zones near wood features. For example, in LW jams in Mosterton, a cross-section with 33.34% wood cover exhibited a velocity coefficient of variation 195.82% higher than the control reach (unwooded), with P value equal to 3.9×10⁻⁴⁴ (Wilcoxon test) confirming that LW significantly drives flow variability. The observed hydraulic heterogeneity defines three functional zones: high‑energy, erosion‑ or scour‑prone reaches; low‑energy, depositional zones; and intermediate turbulent‑mixing areas. By overlaying these flow‑zone maps onto concurrent drone‑derived orthophotos, we can relate flow patterns to specific geomorphic responses such as pool development, bar migration, or bank erosion. This will allow us to predict where erosional and depositional processes are most likely to occur under different LW configurations and flow conditions.
How to cite: Nassaji Matin, G., Panici, D., Bennett, G., and Brazier, R.: Evidence Based Hydraulic and Geomorphic Complexity of Large Wood Interventions for Habitat Creation, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-1298, https://doi.org/10.5194/egusphere-egu26-1298, 2026.
Channel realignment and floodplain reconnection are increasingly used as nature-based solutions for flood management, yet their hydraulic effects remain poorly quantified in field settings. This study examines the impact of such interventions on hydraulic response in a headwater catchment, Goldrill Beck, Cumbria, UK. Here, 1-km of a historically engineered and confined single-thread channel was restored to a more geomorphically complex system. Using a combination of hydrological observational data spanning pre- and post-realignment conditions and two-dimensional hydraulic modeling (LISFLOOD-FP), changes in key hydraulic metrics (flood wave transmission and celerity, reach-scale hysteresis, and peak flow attenuation) were assessed. Results indicate that realignment increased flood wave travel time (median transmission time increased from 15 to 40 min), reduced flow celerity, and altered hysteresis patterns, suggesting enhanced in-channel and floodplain storage under low to intermediate flow conditions. Realignment also improved the diversity of flow biotopes and aquatic habitats, whilst increasing the wetted area by 47%. However, during more extreme events, transmission times decreased, and peak discharge was slightly elevated, highlighting limitations in attenuation potential for large floods. The findings contribute to the evidence base for renaturalisation of watercourses for flood mitigation, emphasizing the role of valley morphometry, channel morphology, and floodplain roughness in influencing hydraulic responses.
How to cite: Perks, M., Barber, N., Heritage, G., Knaggs, J., Reaney, S., Runeckles, H., Williams, N., Wishart, D., and Powell, R.: Hydraulic effects of channel realignment and floodplain reconnection in a headwater stream, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-19914, https://doi.org/10.5194/egusphere-egu26-19914, 2026.
The Danube's discharge in the National Park is highly variable, influenced by Alpine snow and glacier melt as well as regional rainfall. Average flow typically ranges between 1,500 and 1,900 m³/s. Low flow levels can drop to 600–900 m³/s, while 100-year flood events can reach 8,500 – 11,000 m³/s. Due to climate change, there is an overall decreasing trend in growing season (April–September) streamflow, while winter volumes are slightly increasing due to changing precipitation patterns. Snowmelt-driven spring floods are occurring earlier, and often more pronounced, in the year due to reduced mountain snow storage. While major floods are rare due to regulation, extreme precipitation (like the 2002, 2013 or 2024 events) can cause rapid regional flooding with significant geomorphic effects.
The National Park contains the last major “free-flowing” stretch of the Danube in Austria (36 km), yet it faces significant structural and ecological challenges. A major deficit in bedload sediment from upstream dams causes the riverbed to deepen progressively. Management combats this by dumping gravel to stabilize the bed. Paradoxically, while the main bed level sinks, the floodplains (incl. present side arms) are rising due to overbank sedimentation, fragmenting vital floodplain habitats and increasing terrestrialization trends. Projects like "Dynamic Life Lines Danube" aim to foster complete side-arm reconnections to reactivate “natural” erosion and the renewal of aquatic habitats in the adjacent floodplains.
Within the EU-funded “DANube SEdiment Restoration (DANSER): Towards deployment and upscaling of sustainable sediment management across the Danube River basin” project, the Danube Floodplain National Park section comprises an important pilot site in the “Upper Danube DEMO” region. One essential project task is to model the long-term hydro-geomorphic effects of different types of river(scape) management and restoration efforts, such as the reconnection of side-arms. In this presentation, we will highlight the results of different scenario runs using the 2D landscape evolution model CAESAR-Lisflood. We will focus on complex hydro-geomorphic responses to various external (incl. management) and internal perturbations, with a particular focus on the effects of flooding and side-arm reconnections and related long-term consequences for lateral connectivity and riverscape evolution.
This research acknowledges support from the EU Projects HEU DANSER (grant agreement No 101157942)
How to cite: Recinos, S. and Pöppl, R.: Modelling riverscape evolution in the Danube Floodplain National Park (Austria) - Effects of flooding and side-arm reconnections on lateral connectivity and geomorphic change, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-16333, https://doi.org/10.5194/egusphere-egu26-16333, 2026.
As climate change drives the world toward a warmer and more unpredictable future, it presents significant challenges for geographers and geomorphologists: how will Earth's surface evolve? While landscapes may never be in perfect equilibrium with their formative processes, there is no doubt that climate change—and the shifting frequencies, magnitudes, and intensities of geomorphic events—is creating widespread disequilibrium. Rapid, real-time landscape transformation is evident in phenomena such as sea level rise, glacial retreat, mega-wildfires, and permafrost melting. Fundamental questions for current and future generations of earth scientists include: Can we predict the trajectory of these landscapes? How long will the transformations take, and what will the resulting landscapes look like? What will the consequences be for humans and other species, and is our science adequate for the task of prediction?
Southeast Alaska, a vast and dramatic region, serves as a natural laboratory for exploring these questions. Subject to the aforementioned climate drivers, as well as the world’s highest rates of isostatic rebound, frequent tectonic uplift, and exceptional precipitation intensities, the landscape is transforming before our eyes, acting as a global bellwether for geographic change.
Drawing on examples from this dynamic environment, this presentation will explore the prospects for predicting geomorphic change, anticipating its consequences, and extracting lessons applicable to other regions. Specifically we will identify regions where rapidly melting and thinning glaciers are likely to cause dramatic landscape changes, including drainage captures, fluvial redirection, landslide acceleration, and delta abandonment. We will elaborate on the consequences of these plausible changes to ecosystems, human infrastructure, and natural hazards, and suggest the roles that models and scientists might play in anticipating these changes and communicating them to broader audiences.
How to cite: Grant, G., Higman, B. (., and Fasth, B.: Future Geographies: The Shapes of Things to Come, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-4561, https://doi.org/10.5194/egusphere-egu26-4561, 2026.
River processes and its morphodynamics are shaped by a combination of geological, climatic, and human-driven factors. Recently, increasing population pressures, rapid urbanization, and related stresses, such as large-scale water diversions by dams and sediment mining activities, have begun to disrupt riverine systems, raising concerns about their long-term sustainability.
This study investigates the impact of human activities and geological controls on geomorphic change in the Yamuna River, a major Himalayan system that originates from the Yamunotri Glacier at an elevation of 6,387 m and drains a basin of 3.66x105 km² over a distance of 1,376 km. The river flows through the Delhi megacity, which is home to approximately 11 million people. Besides the pressure from the megacity, the presence of the dams and sand mining from the channel bed causes intense anthropogenic stress, making it an ideal system for assessing human impacts on the channel form of a major Himalayan river. Downstream of Delhi, the river is further influenced by three major tributary confluences, which introduce significantly more water and sediment flux into the Yamuna River channel, making it a suitable location to study the natural reference stage of the river.
To evaluate these driving factors, we extracted the active floodplain using the Global Surface Water maximum water extent dataset (1984–2021) and applied the Fluvial Corridor Toolbox to segment the river into discrete geomorphic objects. Using Landsat and Sentinel-2 imagery (1984–2024), we quantified object-based geomorphic parameters, including active channel width, water width, braiding index, and vegetation width, for a 1100 km long part of the river.
Results indicate that human activities, such as dam construction, sand mining, and urban expansion, have significantly altered channel structure across multiple scales, particularly in upstream reaches and within the Delhi region. In the detailed analysis, it was found that the impact of sand mining and the pressure exerted by the Delhi megacity were more prominent than that of the dam. In contrast, the downstream reaches of Delhi reflect a dominant tributary contribution, where these tributaries drive the geomorphic recovery and reorganization of channel form. Together, these patterns demonstrate that the Yamuna is shaped by a complex interplay between human-induced disturbances and natural fluxes from tributaries. Recognizing this dual influence is essential for designing reach-specific, sustainable river management strategies that address both immediate anthropogenic pressures and longer-term geomorphic controls.
How to cite: Singh, S., Rey, L., Karnatak, N., Belletti, B., Piegay, H., and Jain, V.: Disentangling anthropogenic and geological drivers of morphodynamics change in a Himalayan river: The Yamuna River, India, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-985, https://doi.org/10.5194/egusphere-egu26-985, 2026.
Long profiles of alluvial rivers are sensitive to changes in water discharge (Qw) and sediment supply (Qs), both of which depend on local climatic and tectonic conditions. Consequently, changes in prevailing environmental boundary conditions impact the adjustment of river long profiles. Rivers respond through modifications in channel slope, either by steepening via sediment deposition supplied from upstream or by lowering through bed incision driven by sediment entrainment. The time of river long-profile adjustment is commonly estimated using a range of equations derived from models of river evolution. While these formulations are widely applied, they do not distinguish between incision and aggradation and hence predict similar response times, despite these adjustments being governed by different physical processes. As a result, it remains unclear whether incision and aggradation operate on different characteristic timescales of slope adjustment. Given the increasing number of rivers with artificially fixed channel width due to anthropogenic activities, we focus here on the response of fixed-width rivers to changes in boundary conditions. Based data from analogue flume experiments, we investigate how the type of adjustment, i.e., incision or aggradation, affects the response time of slope adjustment of fixed-width rivers to changes in water discharge (Qw) and sediment supply (Qs). Across the experiments, we systematically vary water discharge (Qw), sediment supply (Qs) and grain size, while continuously recording the evolution of the channel slope. Response times are quantified using e-folding fits. We further explore the potential of estimating response times using an Ornstein—Uhlenbeck framework. While both approaches assume exponentially fast adjustment towards new boundary conditions, the Ornstein--Uhlenbeck formulation explicitly incorporates stochastic variability, accounting for model uncertainty and natural slope fluctuations. This makes it a robust alternative for characterizing slope adjustment dynamics. Preliminary results indicate a power-law relationship between steady-state channel slope in and the Qs/Qw ratio, consistent with previous studies. Moreover, the time of slope adjustments increases with the volume of material that has to be eroded or deposited to reach the new long profile. Furthermore, both water discharge (Qw) and sediment supply (Qs) seem to act as catalyst, exerting a primary control on the rate of the slope adjustment in the sense that for fixed Qs/Qw ratio the rate scales positively with an increase in (Qw), implying an increase in (Qs) to retain the ratio Qs/Qw, and vice versa an increase in (Qs). Fluvial systems shape our landscapes. Consequently, characterizing the time of river long-profile adjustment allows for accurate predictions of landscape evolutions, and we expect our results to provide new meaningful insights in that regard.
How to cite: Tiepner, A.: Response times of fixed-width rivers to changes in boundary conditions: Incision vs Aggradation, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-20733, https://doi.org/10.5194/egusphere-egu26-20733, 2026.
The Whitewater River and its tributaries, located in southeastern Minnesota, USA, received intensive geomorphic study starting in 1939. By this point, up to 4.5 meters of sediment buried the prior channel and floodplain. The culprit was agricultural intensification starting with Euro-American settlement around the year 1855. By converting forest and deep-rooted prairie into row crops and grazing land, these settler–farmers set the stage for gullying, erosion, and eventual infilling of the valley floor. Nearly 2000 probes down to the pre-settlement soil provide a ca. 1855 floodplain surface along 94 transect lines. Topographic surveys in 1939, 1965, and 1994 extend this record to about 140 years and the number of total transects to 107. We digitized primary historical sources, many of which existed only as paper records, and built a geospatially registered data set of valley-bottom topography. This data set reveals migrating waves of erosion and deposition over time scales long enough to observe how Earth's surface responds to human disturbance and shape our thinking about river dynamics in fluvial geomorphology.
How to cite: Wickert, A., Wood, J., Larson, P., and Svien, L.: 140 years of river aggradation and incision following Euro-American settlement, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-8932, https://doi.org/10.5194/egusphere-egu26-8932, 2026.
Tropical regions cover 19% of the world's landmass and account for more than 40% of the world's population. Rivers in these zones exhibit significant hydrological and geomorphic dynamism, primarily due to the enormous variability in rainfall and the associated energy regimes, while also supporting some of the world's most productive biological systems. Furthermore, tropical rivers remain among the most heavily regulated, with flow modification, dam construction, and floodplain encroachment all causing significant deviations from natural channel behaviour. The downstream geomorphic consequences of these regulatory pressures are yet poorly constrained, emphasizing the need for large-scale, process-based studies of river variability and its governing mechanisms.
To address this research gap, the present study applies the River Styles Framework, a process-based approach and reach-scale geomorphic classification method, to the Narmada River basin (98,796 km²; 1,312 km), the largest west-flowing system in Peninsular India. The study aims to: (i) classify geomorphically distinct river styles; (ii) identify hydrological, geological, and morphological controls governing transitions along the longitudinal profile; and (iii) formulate reach-specific insights to support sustainable river-management strategies. Geomorphic characterization integrates multi-source remote-sensing datasets, SAR-based floodplain delineation, and field validation of key geomorphic units, including floodplains, riffles, pools, barforms, and planform metrics such as sinuosity. Hydrological variability is quantified through Gumbel flood-frequency analysis of four decades of discharge records to determine spatial and temporal patterns in stream power. Sedimentological assessments combine AI-assisted photogrammetry for coarse fractions with laboratory-based particle-size analysis of finer sediments.
The results show 17 distinct River Styles along the Narmada River continuum. Excluding segments affected by reservoir backwater, approximately 64% of the channel length occurs within confined valley settings, 31% within partly confined reaches, and only 5% within laterally unconfined valley environments. Valley slopes, stream power distribution, tributary confluences, and anthropogenic activities, such as dam construction, emerge as the primary controls on spatial variations in channel form and process.
Overall, the study offers a comprehensive, process-based understanding of geomorphic variation along the Narmada River and identifies reaches with high geomorphic sensitivity that require priority management intervention. By combining geomorphic, hydrological, and sedimentological assessments, the findings provide a robust scientific basis for designing economically viable and sustainable management strategies. Narmada's diverse landscapes, geological discontinuities, and significant climatic gradients make it an ideal natural laboratory for developing approaches applicable to major tropical and monsoon-dominated river systems worldwide.
How to cite: Jha, S. K. and Jain, V.: Tracing Geomorphic Variability and Forcing Mechanisms of a Highly Regulated Tropical River System in India, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-1997, https://doi.org/10.5194/egusphere-egu26-1997, 2026.
The Badlands of the Lower Chambal Valley (LCV) continue to evolve under the combined influence of overland flow, seepage-induced piping, and land-use interventions such as widespread land levelling. Recent work in the region has shown that slope–area (SA) relationships, when combined with width–depth ratios, can differentiate dominant erosion processes and reveal the strong role of soil piping in gully initiation. However, several key research gaps limit the ability to predict where gullies will form—and reform—under changing land management. This contribution outlines emerging research prospects in the LCV. First, the sustainability of land-levelling remains poorly understood: recurrence of gullies on reclaimed parcels suggests that the original erosional thresholds persist in the subsurface, yet the conditions that trigger renewed incision remain unquantified. Second, integrating SA thresholds can offer a new understanding to link surface thresholds with subsurface susceptibility to piping. Third, multi-season monitoring of newly levelled and marginal lands is needed to establish recurrence intervals and identify early-warning indicators of gully reactivation. Finally, combining SA relationship with continuous monitoring of gully recurrence and soil characteristics may allow better understanding of processes that dominate in pristine Badlands and remodelled slopes (land levelling). By framing these prospects, a future direction may be adopted to better understand and possibly check recurrence of gullies in the remodelled slopes.
How to cite: Ranga, V.: Future Directions in understanding gully initiation and recurrence in the Lower Chambal valley, India, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-1059, https://doi.org/10.5194/egusphere-egu26-1059, 2026.
Sand and gravel are mined from rivers globally at unprecedented scales, yet the full extent and impacts of this extraction remain underrecognized relative to other environmental crises. Here we present a comprehensive review of riverine sand and gravel mining (SGM), synthesizing 279 studies published over the last five decades within a novel Driver-to-Management Pathway for Sustainable Mining (DMPSM) framework. This framework links the drivers of SGM, the spatial extent of extraction, and the resulting hydrogeomorphic impacts to inform sustainable management strategies. Our synthesis reveals pronounced spatial and scalar mismatches among the scales of drivers, extraction, and impacts: the socioeconomic drivers of sand demand often act at regional to global levels, whereas extraction extents are poorly quantified at local scales, and impacts can propagate far beyond mining sites, complicating effective governance. Excessive sand removal disrupts sediment budgets, triggering riverbed incision, bank erosion, and channel instability. These geomorphic changes steepen hydraulic gradients, lower alluvial water tables, and reduce hyporheic exchange, collectively degrading riverine habitats and water resources. We further find that SGM impacts are compounded by multiple anthropogenic stressors: upstream dams trap sediment, land‐use changes increase sediment demand, and climate change alters flow regimes, creating compounding feedbacks that accelerate channel degradation. Our global synthesis underscores the urgent need for improved monitoring across scales and integrated management and governance strategies to bridge these disconnects. Aligning extraction with natural sediment replenishment, strengthening regulatory frameworks and enforcement, and enhancing stakeholder engagement are critical steps to mitigate SGM’s cumulative impacts and ensure sustainable river basin management.
How to cite: Park, E., Hackney, C., Bendixen, M., Best, J., Tran, D. D., and Kumar, S.: River sand and gravel mining: A global synthesis of drivers, extents and impacts for sustainable management, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-3729, https://doi.org/10.5194/egusphere-egu26-3729, 2026.
River management is often driven by energy production, irrigation crops, and flood mitigation, largely enabled by widespread dam construction. However, river damming has brought severe environmental consequences for river dynamics, including morphological changes, hydrological regime, and interruption of the sediment cascade. These physical changes have profound impacts on the ecology of numerous fish species, particularly highly migratory ones, which, together with parallel drivers, led to an 85% reduction in world freshwater species populations since 1970. This work aims to provide a methodological framework for identifying priority rivers within the Portuguese strategy for improving river connectivity affected by obsolete dams and weirs under the European Nature Restoration Law.
The official fish dataset of the Portuguese Institute for Nature Conservation and Forests was first used, which included >20,000 occurrences for 61 fish species between 2010 and 2020. Each species was classified according to the following variables: species origin (native, exotic), conservation status (Critically Endangered, Endangered, Vulnerable, Near Threatened, Least Concern, Data Deficient, Not Evaluated), phenology (diadromous, potamodromous, resident), socioeconomic importance (very high, high, low significance), and endemism degree (Iberian or Lusitanian endemism). A score was attributed to each criterion, and the species index was calculated using Equation 1. Finally, to ensure functional connectivity to the ocean, we have included the lowermost segment of the main rivers up to the first insurmountable dam.
Equation 1: R = a · (0,25 · Xi + 0,40 · Xii + 0,20 · Xiii + 0,15 · Xiv)
Where the species index (R) resulted from the multiplication of the origin coefficient (α: species origin) with the weighted mean of the variables (Xi: conservation status; Xii: phenology; Xiii: socioeconomic importance; Xiv: endemism degree).
In parallel, hydrographic modelling was carried out using the Strahler model to ensure full representation of the Portuguese river network and a hierarchy adjusted to the sub-basin scale. The sub-basins were selected based on the 4th, 5th, 6th, and 7th Strahler hierarchies, and the excluded areas in the main river margins were included using the 8th hierarchy. For each sub-basin, the arithmetic mean of the species index was calculated within the Geographical Information System environment. The prioritization for river restoration was based on the upper quartile means for each hydrological region independently.
All rivers within the prioritized sub-basins were divided into segments according to the 3rd cycle of River Basin Management Plans and the Water Framework Directive, as provided by the Portuguese Environmental Agency. Each segment was classified according to water quality (chemical status and ecological quality), and segments were excluded if these criteria were simultaneously negative. At this stage, the Strahler 3rd-order streams connected to selected segments were included to guarantee ecological coherence in fluvial connectivity. The presence of a protected area (Natura 2000) and the density of transversal barriers were also evaluated. Finally, the national barrier dataset was updated using satellite imagery to identify new barriers.
In total, 77 rivers, encompassing ca. 6500 km at the sub-basin scale, were prioritized within the Portuguese strategy to improve river connectivity affected by obsolete dams and weirs.
How to cite: Fernandes, M., Alexandre, C., Boavida-Portugal, J., Quintela, B., Pedro, S., Carona, S., Ramalho, M., Pereira, E., Rato, A., and Raposo de Almeida, P.: A GIS-based multi-criteria method for prioritizing river restoration in Portugal, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-10435, https://doi.org/10.5194/egusphere-egu26-10435, 2026.
Geoinformation tools (GIT) allow for the identification of historical and current riverbeds and previous anthropogenic interventions to river systems. Due to the decreasing costs of high-precision data acquisition and the necessary hardware, GIT has become a standard tool for monitoring the fluvial dynamics of watercourses.
Czech rivers have long been influenced by human activity. The most significant engineering interventions were carried out during the 20th century, driven by efforts to maximize agricultural land use and ensure flood protection. Over the past two decades, efforts to remediate these impacts have emerged on a small portion of Czech rivers, primarily in the form of "revitalization". This involves constructing new channels using more natural materials, such as stone instead of concrete
The Nature Restoration Regulation (NRR, adopted in June 2024) requires that by 2030, at least 25,000 kilometres of free-flowing rivers be restored in EU countries compared to 2020 levels. This requires identifying and removing artificial structures to restore the natural functions of watercourses and enhance sediment erosion and deposition. Most modifications to Czech rivers have focused on stabilizing flows and river banks, preventing flooding, enabling farming, and ensuring sustainable water use for human needs. However, those aims are not compatible with NRR's concept of free-flowing rivers. Recently, some "renaturation" projects have attempted to restore river dynamics and functions in the Czech Republic. These projects remain in the minority due to the societal inertia of over a century of engineering approaches and restrictions on river dynamics.
This contribution presents several examples of recent renaturation projects in the Czech Republic. The first examples are innovative projects on three-kilometre-long sections of two headwater streams in the Ore Mountains. From 2009 to 2010, the previously channelized stream was reconstructed in a meandering pattern following former revitalisation strategy. The recent renaturation project in this area began in August 2023 and ended in April 2024. It began with the decommissioning and backfilling former, deeply incised, artificial channels to allow the water to create its own paths and to support of a self-evolving channel - an approach fully compatible with NRR objectives. Another project was implemented on a five-kilometre section of a Czech lowland river. There, an embankment was transformed into near-natural banks with artificial channel bars and side arms.
We used a LiDAR-equipped drone to generate digital terrain models (DTMs) and a full-frame camera to produce high-resolution orthomosaics to monitor the restoration of channel dynamics. We subsequently used this data for morphological and hydrological analyses by the ArcGIS (Esri) software. Field surveys were also conducted. To evaluate the restoration of channel dynamics, the headwater streams were monitored four times a year for two years, and the lowland river was monitored three times a year for two years. The monitoring demonstrated success with renaturation of the headwater streams. However, the modifications to the lowland river were more robust, so significant channel dynamics did not manifest within the two-year evaluation period. The results show viable pathways to meet the NRR requirements.
How to cite: Elznicová, J., Brétt, D., Matys Grygar, T., Rous, J., Rous, V., Weber, O., and Tačovský, Z.: Geoinformation Tools in the Evaluation of River Renaturation Projects in the Czech Republic, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-16644, https://doi.org/10.5194/egusphere-egu26-16644, 2026.
Large wood (LW; >10 cm in diameter and >1 m in length) within river corridors – including channels and adjacent floodplains – plays a key role in shaping hydraulic conditions, sediment deposition and erosion, nutrient cycling, and habitat availability for aquatic and terrestrial species. Thus, to fully understand how a river system functions, we must understand when, how, and why LW is stored or transported. Most previous work on understanding LW dynamics in river systems has focused on LW behavior in channels, overlooking the possible importance of floodplains on how LW moves through these systems. Leveraging video datasets from a series of flume experiments on LW behavior in forested river corridors, we tracked LW piece movement to understand controls on LW trajectories and deposition patterns.
We analyzed of a set of 36 experiments conducted in a 4m wide by 10m long fixed bed flume at St. Anthony Falls Laboratory at the University of Minnesota. The flume represented a river corridor for a relatively steep, headwater stream in the central Rocky Mountains. These experiments explored variations in LW transport and deposition across a range of 4 floodplain forest stand densities, 2 overbank flood magnitudes and 2 LW transport regimes (the amount of LW added at one time). For each experiment, we dropped a total of 870 pieces into the channel at the head of the flume and observed where they were deposited. Using video data from the experiments, we developed a dataset of wood piece trajectories under different conditions. The videos were collected using four nadir-oriented GoPro cameras mounted above the flume surface. We orthomosaiced the video streams and stitched them together to form a single video covering the entire experimental surface at a resolution of 2mm/pixel and 24 frames/second. We then retrained and tested a python-based convolutional neural network (CNN) for real-time object detection and tracking called YOLO (You Only Look Once) v11 (Redmon et al., 2016) on 2000 images of LW in the flume (70/30 train/test split). We ran this object detection model for each experiment, resulting in a dataset of LW trajectories for hundreds of LW pieces for each of the 36 experiments. We performed survival analysis on distances traveled by each piece using the Kaplan-Meier method to statistically assess how far LW pieces tended to travel in each experiment.
We present results of the survival analysis for each experiment compared across forest stand densities, flood magnitudes and transport regimes. We found that sparser forests and larger overbank floods increased transport distances. Additionally, as each experiment progressed, there were changes in the distance traveled by pieces, likely due to the formation of jams that promoted wood deposition in specific locations. These analyses advance our understanding of how LW moves in forested river corridors by providing information at the wood piece level – something rare among LW studies. Additionally, these results will support future efforts to use IberWood (a 2D numerical model of river flow and LW transport) to connected channel-floodplain systems, improving tools used to inform river restoration and management.
How to cite: Welsh, J., Lininger, K., and Ruiz-Villanueva, V.: How does wood move on forested floodplains? Wood tracking in flume experiments of a forested river corridor, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-7646, https://doi.org/10.5194/egusphere-egu26-7646, 2026.
Stream-road crossings arise when natural fluvial networks (emerging over geological timescales) intersect built transportation networks (which are designed). Such conflicting intersections are resolved by installing conveyance infrastructure, such as culverts and bridges, which mitigate flood risk to adjacent communities and prevent disruptions to the transportation networks. Studying the spatial distribution of stream-road crossings across large, geographically diverse spatial scales can shed light on how the density of these crossings depends on topographic, geomorphic, hydrologic, and urban controls. In this research, we address these questions by performing a large-scale analysis of the stream-road crossings of New York State (~141,000 sq. kilometers). We use a grid–based scheme at several spatial resolutions (initially 10×10 km and 5×5 km), which allows us to study the effect of the spatial resolution on the observed distributional patterns. Looking beyond the primary effect of stream and road densities, this study focuses on identifying dependence on second–order drivers that characterize the stream–road crossing distribution. For this analysis, we employ large remotely-sensed geospatial datasets as features. Given the high dimensionality of the feature space and the strong presence of multicollinearity, dimensionality reduction techniques are used to identify latent structures and dominant modes of variability, while clustering methods are applied to separate regions with internally consistent geospatial characteristics. We finally compare outcomes across spatial resolutions to generate insights on how inferred relationships depend on various hydrologic, geomorphic, and land-use features.
How to cite: Ponce-Pacheco, M. A., Karpagamala, S., Emamjomehzadeh, O., Kilicarslan, B. M., and Wani, O.: What controls the spatial distribution of stream-road crossings? , EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-15047, https://doi.org/10.5194/egusphere-egu26-15047, 2026.
Sediment accumulation at river confluences can severely compromise fairway stability and navigation safety. To provide a non-invasive alternative to dredging, a novel low-water training concept based on “flexible infrastructure” has recently been introduced, using temporarily anchored, ballasted barges to locally modify flow conditions and induce targeted bed erosion. This study evaluates the morphodynamic influence of barge location at the confluence and identifies hydraulic conditions under which this approach is most effective. A three-dimensional numerical model was developed in FLOW-3D, to evaluate scour and deposition patterns around deployed barge. Hydraulic and sediment transport calibration was performed using in situ ADCP velocity measurements and bathymetric surveys collected over a 10-day low-flow period. A series of numerical experiments was conducted using identical geometric configurations while varying boundary conditions (flow velocity and water depth) over low, mean, and high flow conditions. This study analyze the relative influence of flow velocity, water depth, and flow contraction on the maximum local scour beneath the barge. Results indicate that flow contraction and velocity are the dominant controls on barge performance, while barge effectiveness becomes negligible under high-flow conditions associated with large water depths. These findings demonstrate that barges can serve as adaptable and environmentally low-impact infrastructure elements for localized sediment management.
Acknowledgements
This work has been funded in part by the iNNO SED project. This project has received funding from the European Union’s Horizon Europe research and innovation programme under grant agreement No. 101157360.
This publication uses information and/or outputs developed within the FAIRway Danube II project. The authors acknowledge the FAIRway Danube II consortium for making relevant datasets, methodologies, and results available
How to cite: Harasti, A. and Gilja, G.: Impacts of Barge as Flexible Infrastructure on Riverbed Morphology, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-9544, https://doi.org/10.5194/egusphere-egu26-9544, 2026.
Posters virtual: Tue, 5 May, 14:00–18:00 | vPoster spot 3
EGU26-7986 | Posters virtual | VPS26
Hydrologic-hydraulic modelling and flood hazard mapping for infrastructure resilience in a small mountainous catchment on Northern GreeceTue, 05 May, 14:09–14:12 (CEST) vPoster spot 3
Flood-prone small mountainous catchments hosting critical infrastructure, such as bridges and transport networks, require integrated hydrologic–hydraulic analyses to ensure long-term resilience under changing climatic and land-use conditions. This study develops a coupled HEC-HMS–HEC-RAS modelling framework to quantify design discharges, inundation patterns and local hydraulic controls for the torrential stream crossing the settlement of Kato Nevrokopi in Northern Greece. Using high-resolution topographic data (DEM), GIS-based basin delineation and long-term rainfall records, design storms for multiple return periods are derived and transformed into flood hydrographs at the catchment outlet. These hydrographs force 1D steady-flow simulations in HEC-RAS, explicitly representing bridges, piers and local constrictions that act as morphodynamic bottlenecks and potential failure points under extreme flows. Model results are used to generate flood extent and water-depth maps for events up to the 1,000-year return period, identify critical cross-sections where afflux and backwater effects are most pronounced, and assess the effectiveness of alternative layout and channel-training configurations. The analysis is framed within the current EU Floods Directive 2007/60/EC and Greek legislation for stream delineation, linking quantitative hazard metrics to planning constraints and infrastructure design requirements. The work highlights how relatively simple, openly available tools, when combined with detailed geometric representation of bridges and channel morphology, can support evidence-based decisions on flood protection works, minimise over-engineering, and improve the adaptive management of critical infrastructure in steep, data-scarce basins.
How to cite: Pavlidis, K. and Valyrakis, M.: Hydrologic-hydraulic modelling and flood hazard mapping for infrastructure resilience in a small mountainous catchment on Northern Greece, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-7986, https://doi.org/10.5194/egusphere-egu26-7986, 2026.
EGU26-8868 | ECS | Posters virtual | VPS26
Natural Riverbed Stability in a Small-to-Medium-Sized Mountainous River: A Baseline Investigation of the Qin River Prior to the Pinglu Canal ConstructionTue, 05 May, 14:12–14:15 (CEST) vPoster spot 3
The construction of mega-canals necessitates a profound understanding of the pre-existing fluvial equilibrium to mitigate adverse geomorphic consequences, particularly in rivers with limited channel capacity. This study focuses on the intrinsic stability mechanisms of the Qin River, a typical small-to-medium-sized mountainous river in South China, prior to the implementation of the Pinglu Canal project. Field surveys and sediment analyses were conducted to characterise the natural bed state, with a focus on a morphologically representative reach. The findings indicate that the riverbed has historically maintained a strong dynamic equilibrium, supported by lateral confinement from riparian vegetation and natural armor processes unique to mountainous fluvial regimes, which are derived from tributary inputs. The analysis reveals that specific hydrodynamic thresholds and sediment connectivity are essential for maintaining this stability. Therefore, rather than hydraulic stress alone, the system's main vulnerability is determined to be the possible disruption of these established equilibrium conditions, particularly with regard to geological substrate constraints and longitudinal continuity. These results establish a scientific standard for assessing the potential disturbance risks of canalization in delicate mountainous river systems by providing a critical morphodynamic baseline.
How to cite: Zhu, S., Sun, J., Liu, C., Chen, L., and Chen, W.: Natural Riverbed Stability in a Small-to-Medium-Sized Mountainous River: A Baseline Investigation of the Qin River Prior to the Pinglu Canal Construction, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-8868, https://doi.org/10.5194/egusphere-egu26-8868, 2026.
EGU26-21498 | Posters virtual | VPS26
Integrating Google Earth Engine Cloud Computing and Fluvial Surveys to Quantify Vegetation–Hydrology–Sediment Coupling in Contrasting Braided River SystemsTue, 05 May, 14:18–14:21 (CEST) vPoster spot 3
The non-linear feedback mechanisms and interactions between discharge-sediment supply and instream (riparian) vegetation cover generate spatio-temporal heterogeneity in braided channel forms. The present study examines such relationships among three contrasting braided rivers of India: the Brahmaputra (highly braided), the Brahmani (weakly braided) and the Netravathi (meandering-braided). Long term JRC Surface water layer, vegetation-water remote sensing indices, numerical model derived hydrological datasets and periodic field visits have been integrated to understand the vegetation–hydrology–sediment coupling across these braided river systems. The results show that the channel forming discharges in the Brahmaputra shows a hierarchical level and extreme events dominate over the effect of sparse vegetated landforms. In weakly braided reaches, channel-in-channel form oscillates between two extreme nodes depending upon the intensity of disturbing events. For rivers with meandering-braided transition form, channels are relatively stable and riparian vegetation cover generate a stable geometry and absence of floodplain sediment storage.
How to cite: Pradhan, C.: Integrating Google Earth Engine Cloud Computing and Fluvial Surveys to Quantify Vegetation–Hydrology–Sediment Coupling in Contrasting Braided River Systems, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-21498, https://doi.org/10.5194/egusphere-egu26-21498, 2026.
EGU26-2250 | ECS | Posters virtual | VPS26
Feasibility of Action Camera-Based Videogrammetry for Multi-Temporal 3D Monitoring of Rubble-Mound BreakwatersTue, 05 May, 14:21–14:24 (CEST) vPoster spot 3
Coastal protection infrastructures such as rubble-mound breakwaters (RMBs) demand frequent geometric inspection to quantify armor-layer dynamics and support reproducible structural monitoring. While UAV-based photogrammetry and LiDAR are established reference techniques for rapid 3D mapping, high revisit rates remain operationally constrained by wind sensitivity, sensor payload limits, and regulatory flight restrictions. Videogrammetry complements these approaches by increasing inter-frame overlap and mitigating missed-trigger acquisitions, especially useful in complex coastal scenes (e.g., those affected by occlusions between armor units and block interstices). As in conventional photogrammetry, videogrammetry relies on image redundancy and self-calibration rather than highly sophisticated instrumentation. Despite this potential, consumer-grade action cameras remain scarcely validated for multi-epoch 3D monitoring in coastal engineering, mainly due to wide-angle lens distortion and coarse onboard GNSS geotag precision.
This study assesses pole-mounted GoPro videogrammetry for multi-temporal 3D relative change detection in the emerged portions of a detached rubble-mound breakwater at Cabedelo do Douro (PT). Two survey epochs were acquired in July 2024 and November 2024 to characterize the above-water zone, inspecting the seaward slope, the landward armor-toe transition, and the horizontal crest platform segment at one of the heads of the RMB. Frames were extracted at 1 Hz and processed in Metashape using an SfM-MVS (Structure-from-Motion Multi-View Stereo) self-calibrating camera model. Multi-epoch point clouds were coregistered in CloudCompare with ICP (Iterative Closest Point) refinement over stable crest and toe areas, and 3D changes were quantified using M3C2 (Multiscale Model-to-Model Cloud Comparison), generating signed distance maps and detection histograms. A concurrent UAV-RTK survey, supported by additional GNSS-measured ground control points (GCPs), served as a geometric benchmark.
Mean ActionCam-to-UAV sensor offsets were +0.06 m, confirming that, despite potentially unstable absolute georeferencing in GoPro-derived reconstructions, the resulting point clouds preserve sufficient geometric and scale consistency to support relative multi-temporal 3D change detection and the identification of concrete armor-unit displacements. Results confirm that pole-mounted videogrammetry supports rapid, repeatable, low-cost SHM (Structural Health Monitoring) observations, providing defensible detection thresholds and reproducible change-detection limits for engineering interpretation and maintenance support.
How to cite: Martínez Olmedo, V., Bento, A. M., Arza-García, M., and Gonçalves, J. A.: Feasibility of Action Camera-Based Videogrammetry for Multi-Temporal 3D Monitoring of Rubble-Mound Breakwaters, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-2250, https://doi.org/10.5194/egusphere-egu26-2250, 2026.
