The Bagnold Medal Lectures from the medallists from 2020 and 2021 will be presented in this flagship GM session. The session will be introduced by the GM President, Daniel R. Parsons and citations given for each of the Medallists.

Landscapes, and how they change over time, provide the foundations of life and affect the ecosystems and human activities that can exist on Earth. Yet, there appears to be no single axis of causality between landscape and Earth surface processes, but rather, each entity can exert a simultaneous influence on the other over a wide range of temporal and spatial scales. We are just starting to realise and explore the modes, trajectories and effects of these coupled systems, and to trace and infer the often non-linear feedback mechanisms.
Geomorphology inevitably stands in the center of an emerging science devoted to the Earth's surface, where strong couplings link human dynamics, biology, biochemistry, geochemistry, geology, hydrology, geomorphology, soil science, and atmospheric dynamics, including past and ongoing climate changes.
Motivated by the importance of understanding Earth surface interactions, couplings and feedbacks on a rapidly changing globe, this session will bring together a series of invited speakers to provide insights and perspectives on this hot topic from across the field of geomorphology.

Biogeomorphology addresses the two-way interaction between biotic and abiotic elements that shape landscapes at various spatio-temporal scales. Yet, developing theory, methods and quantifying processes at the abiotic/biotic interface remains challenging due to the interdisciplinarity of biogeomorphology, integrating concepts from ecology, evolutionary biology, engineering, geomorphology, geology and Quaternary science. On the other side, there is an urgent need to understand the interactions among abiotic and biotic processes in natural and managed systems to adapt to for instance climate change.
Consequently, a wide range of interdisciplinary projects in fields related to biogeomorphology have emerged. Such projects have included field, computational, and laboratory studies across a wide range of scales to understand the effects of underlying physical and ecological processes on biogeomorphic interactions.
This session focuses on the lessons learned from such approaches: advantages, limitations, best practices, and the future of the discipline of biogeomorphology. Research topics include, but are not limited to: 1) Biogeomorphic processes, rates and feedbacks, 2) Organism-Habitat interaction, 3) Biota as ecosystem engineers, 4) Effects of biogeomorphic interactions on nutrient and pollutant transport, 5) Biogeomorphology for the development of nature-based-solutions.

Almost 30 years of developing the concept of geodiversity in geosciences provides a robust foundation for moving to the issue of synthesizing the existing knowledge and methods of assessing geodiversity and to disseminate the achievements of this concept.
1. The spatial and temporal scales. On what cartographic scale should the source materials be useful for determining the degree of geodiversity? Can geodiversity be considered on a local, regional, national, continental and global scale? Having in place geodiversity (stationary, at a given time of observation/assessment) and dynamic geodiversity at your disposal - how deep, how far can you reach the past and the future in geodiversity assessments of any area? Can geodiversity be determined in a palaeogeographic/geological context? How can you use geodiversity to describe geosites, geoparks, landscapes, and other forms of geoconservation? How to translate geodiversity values into geoheritage measures?
2. The lack of a standard for geodiversity assessment. Is the quality or quantity (number) of assessed geodiversity features important? How to transform qualitative assessments into quantitative assessments, so that you can easily compare different areas in terms of their substantive value, not to mention independence from the spatial and temporal scale? These issues are related to the problem of uncertainty in geodiversity assessments. This problem affects applied geodiversity studies as well, limiting further qualitative/qualitative assessment of abiotic ecosystem services. So what should be the standards of this geodiversity assessment to minimize errors in assessments?
3. If we find a consensus in establishing a standard for geodiversity assessment, how to apply the developed standard at geoconservation and geoheritage? How to consider such a standard universally acceptable? What forms of activity should best promote the idea of geodiversity? How to implement geodiversity assessments by professionals for different forms of geoconservation and geoheritage? Which ecosystem services should be taken into account in determining the importance of geodiversity for human life? How to make the society aware of the importance of geodiversity in their everyday life? How to extend the geodiversity values to preserve the state of the environment for future generations? How to link the idea of geodiversity with 17 UN SDG? Finally, how should geodiversity values be compared with biodiversity values?

Geomorphic processes (e.g fluvial, erosion, slope, aeolian, glacial) shape landscape and affect sediment fluxes in a variety of environments across different spatial and temporal scales. Quantifying processes requires understanding both the effect of landscape components (natural and anthropic) and dynamics responsible for sediment/soil mobilization, storage and delivery (sources-pathways-sinks).
We welcome contributions using traditional methods and/or innovative techniques (e.g. field-based measurements, compositional analysis, GIS-based morphometry, remote sensing, sediment tracing or fingerprinting, cosmogenic and fallout radionuclides, statistical tools, modelling approaches…) for quantifying morphodynamic and sedimentary processes.
The session seeks contributions from any discipline investigating:
(i) topographic, lithologic, climatic and tectonic controls on sediment production and transport from source to sink;
(ii) connectivity and links among geomorphic components;
(iii) quantification of erosion/sedimentation/weathering rates and their variability in space and time;
(iv) environmental signal propagation in Sediment Routing Systems;
(v) redistribution processes through soil, sediment tracing and particle trajectory;
(vi) autogenic processes regulating sediment transport, temporary storage, and deposition;
(vii) interplay between geo-environmental and anthropic processes in geomorphic and sedimentary dynamics;
(viii) compositional analysis of the erosional products;
(ix) forward modelling of sedimentary and geomorphic response to climate change.
Multi- and inter-disciplinary studies are particularly encouraged. We hope to use the session to discuss different perspectives in the viewpoint of an integrated framework, filling the gaps among disciplines.

Two significant flow hazard cascades have been captured with unprecedented detail, with events in Elliot Creek and Bute Inlet (Canada) and the Chamoli and Uttarakhand (India) both occurring with the past few months. These events both have a suite of background observations and baseline datasets on which to contextually place and explore these flows end events in a depth and breadth of detail that is unprecedented, potentially unlocking new understanding of hazard cascades from source to sink.
We welcome contributions that (i) investigate the processes of production, mobilisation, transport, and deposition of sediment in these two events, (ii) explore the feedbacks between erosion and deposition of the flows through these systems, (iii) consider how these flows shape new understanding of hazards cascades through the source to sink linkages. We invite papers that are observational, analytical or modelling based in their approach, across a variety of temporal and spatial scales. We particularly welcome new and innovative methodologies that show potential to unlock new understanding.

Age models are applied in paleoclimatological, paleogeographic and geomorphologic studies to understand the timing of climatic and environmental change. Multiple independent geochronological dating methods are available to generate robust age models. For example, different kinds of radio isotopic dating, magneto-, bio-, cyclostratigraphy and sedimentological relationships along stratigraphic successions or in different landscape contexts. The integration of these different kinds of geochronological information often poses challenges.
Age-depth or chronological landscape models are the ultimate result of the integration of different geochronological techniques and range from linear interpolation to more complex Bayesian techniques. Invited speakers, Sebastian Breitenbach from CL division and Rachel Smedley from the GM division, will share their experience in several modelling concepts and their application in a range of Quaternary paleoenvironmental and geomorphologic records. The Short Course will provide an overview of age models and the problems one encounters in climate science and geomorphology. Case studies and practical examples are given to present solutions for these challenges. It will prepare the participants from CL, GM and other divisions for independent application of suitable age-depth models to their climate or geomorphologic data. For registration please send a request via this email address (ecs-cl@egu.eu) prior to 15th April.

Water is our planet’s most vital resource, and the primary agent in some of the biggest hazards facing society and nature. The twin pressures of population growth and a rapidly changing global climate act as multipliers of water’s value and of water-related hazards.

River streamflow is one of the most crucial hydrological variables for ecology, for people and industry, for flood risk management and for understanding long term changes to the hydrological regime. However, despite significant efforts, long-term, spatially dense monitoring networks remain scarce, and even the best monitoring networks can fail to perform when faced with extreme conditions, and lack the precision and spatial coverage to fully represent crucial aspects of the hydrological cycle.

Happily, a number of new technologies and techniques are emerging which show great potential to meet these challenges. In this context, this session focuses on:
1) Innovative methodologies for measuring/modelling/estimating river stream flows;
2) Real-time acquisition of hydrological variables;
3) Remote sensing for hydrological & morphological monitoring;
4) Measuring extreme conditions associated with a changing climate;
5) Measurement of sudden-onset extreme flows associated with catastrophic events;
6) Strategies to quantify and describe hydro-morphological evolution of rivers;
7) New methods to cope with data-scarce environments;
8) Inter-comparison of innovative & classical models and approaches;
9) Evolution and refinement of existing methods;
10) Guidelines and standards for hydro-morphological streamflow monitoring;
11) Quantification of uncertainties;
12) Development of expert networks to advance methods.

Contributions are welcome with an emphasis on innovation, efficiency, operator safety, and meeting the growing challenges associated with the changing climate, and with natural and anthropogenically driven disasters such as dam failures and flash floods.

Additionally, presentations will be welcomed which explore options for greater collaboration in advancing riverflow methods and which link innovative research to operational monitoring.

This session is sponsored by the COST Action CA16219, Harmonisation of UAS techniques for agricultural and natural ecosystems monitoring (HARMONIOUS).

Sedimentary processes in aquatic environments, including entrainment, transport and deposition of sediment by hydrodynamic mechanisms, are key features for various research disciplines, e.g. geomorphology and paleoclimatology or hydraulics and river engineering. An accurate evaluation of entrainment, transport and deposition rates, conditioning river channel morphology and bed composition, is fundamental for an adequate development of conceptual sediment budget models and for the calibration and validation of numerical tools.
The main goal of this session is to bring together the community of scientists, scholars and engineers, investigating, teaching and applying novel measurement techniques and monitoring concepts, which are crucial to determine sedimentary and hydro-morphological processes in rivers, lakes and reservoirs, estuaries as well as in coastal and maritime environments. Within the focus of this session are the evaluation and quantification of bed load and suspended load, flocculation, settling, and re-suspension of such processes relevant to morphological channel changes as bed form development, horizontal channel migration, bed armouring and colmation.
Contributions are welcome with a particular focus on single and combined measurement techniques, on post-processing methods as well as on innovative and advanced monitoring concepts for field applications. Furthermore, we welcome contributions containing recent results in a temporal and spatial scale on sediment budgets as well as on sedimentary and morphodynamics processes in open water environments.
Contributions may refer, but are not restricted, to:
- measurements of suspended sediment transport in open water environments, e.g. with optical, acoustical, traditional sampling methods or others;
- measurements of bed load transport, e.g. with bed load samplers, sediment traps, tracers or acoustic and optical methods;
- determination of sediment characteristics, e.g. with mechanical bed material samplers or freeze core technique;
- measurements of critical bed shear stress of cohesive sediments, e.g. with benthic flumes or miscellaneous devices;
- monitoring of morphological changes like lake and reservoir sedimentation, bank erosion or bed armouring, meandering migration, river bends evolution;
- measuring networks / multiple point datasets;
- monitoring concepts including case studies;
- in-situ as well as laboratory calibration of measurement data;

Smart monitoring and observation systems for hazards, including satellites, seismometers, global networks, uncrewed vehicles (e.g., UAV), and other linked devices, have become increasingly abundant. With these data, we observe our Earth’s restless nature and work towards improving our understanding of hazard processes such as landslides, debris flows, earthquakes, floods, storms, volcanic eruptions, and tsunamis. The large amount of data we have now accumulated with diverse measurements presents an opportunity for earth scientists to employ statistically driven approaches that speed up data processing, improve model forecasts, and give insights into the underlying physical processes. Such big-data approaches are supported by the wider scientific, computational, and statistical research communities who are constantly developing data science and machine learning techniques and software. Hence, data science and machine learning methods are rapidly impacting the fields of geohazards. In this session, we will see research into hazards spanning a broad range of time and spatial scales.

Geomorphometry and geomorphological mapping are important tools used for understanding landscape processes and dynamics on Earth and other planetary bodies. The recent rapid advances in technology and data collection methods has made available vast quantities of geospatial data for such morphometric analysis and mapping, with the geospatial data offering unprecedented spatio-temporal range, density, and resolution, but it also created new challenges in terms of data processing and analysis.

This inter-disciplinary session on geomorphometry and landform mapping aims to bridge the gap between process-focused research fields and the technical domain where geospatial products and analytical methods are developed. The increasing availability of a wide range of geospatial datasets requires the continued development of new tools and analytical approaches as well as landform/landscape classifications. However, a potential lack of communication across disciplines results in efforts to be mainly focused on problems within individual fields. We aim to foster collaboration and the sharing of ideas across subject-boundaries, between technique developers and users, enabling us as a community to fully exploit the wealth of geospatial data that is now available.

We welcome perspectives on geomorphometry and landform mapping from ANY discipline (e.g. geomorphology, planetary science, natural hazard assessment, computer science, remote sensing). This session aims to showcase both technical and applied studies, and we welcome contributions that present (a) new techniques for collecting or deriving geospatial data products, (b) novel tools for analysing geospatial data and extracting innovative geomorphometric variables, (c) mapping and/or morphometric analysis of specific landforms as well as whole landscapes, and (d) mapping and/or morphometric analysis of newly available geospatial datasets. Contributions that demonstrate multi-method or inter-disciplinary approaches are particularly encouraged. We also actively encourage contributors to present tools/methods that are “in development”.

Seismic techniques are becoming widely used to detect and quantitatively characterise a wide variety of natural processes occurring at the Earth’s surface. These processes include mass movements such as landslides, rock falls, debris flows and lahars; glacial phenomena such as icequakes, glacier calving/serac falls, glacier melt and supra- to sub-glacial hydrology; snow avalanches; water storage and water dynamics phenomena such as water table changes, river flow turbulence and fluvial sediment transport. Where other methods often provide limited spatial and temporal coverage, seismic observations allow recovering sequences of events with high temporal resolution and over large areas. These observational capabilities allow establishing connections with meteorological drivers, and give unprecedented insights on the underlying physics of the various Earth’s surface processes as well as on their interactions (chains of events). These capabilities are also of first interest for real time hazards monitoring and early warning purposes. In particular, seismic monitoring techniques can provide relevant information on the dynamics of flows and unstable slopes, and thus allow for the identification of precursory patterns of hazardous events and timely warning.

This session aims at bringing together scientists who use seismic methods to study Earth surface dynamics. We invite contributions from the field of geomorphology, cryospheric sciences, seismology, natural hazards, volcanology, soil system sciences and hydrology. Theoretical, field based and experimental approaches are highly welcome.

Solicited presenter: Kate Allstadt - USGS Geologic Hazards Science Center, Golden, CO, USA

Numerical frameworks are essential for understanding and interpreting landscape evolution. Over recent decades, geochronological techniques such as luminescence dating, cosmogenic nuclides and thermochronology have improved in accuracy, precision and temporal range. Developments in geochronological methods, data treatment and landscape evolution models have provided new insights into the timing, duration and intensity of landscape evolution processes. This combination of temporal constraints and numerical models has enormous potential to improve our understanding of landscape evolution. The session aims to bring together new research in using geochronology and data science to investigate Quaternary landscape change.

This session includes studies of erosional rates and processes, sediment provenance, burial and transport times, bedrock exposure or cooling histories, landscape dynamics, and the examination of potential biases and discordances in geochronological data and model-data comparisons. We welcome contributions that apply novel geochronological techniques, combine different geochronological techniques, combine numerical age constraints with landscape evolution models to determine rates and timing of landscape change as well as stochastic events, or that highlight the latest developments and open questions in the application of geochronometers to landscape evolution problems.

A key goal within geomorphic research is understanding the processes linking topographic form, erosion rates, sediment production, transport and deposition, and external forcings such as tectonics, biotic or climatic. Numerical modelling, by allowing the creation of controlled analogues of natural systems, provides exciting opportunities to explore landscape evolution and generate testable predictions.

In this session, we invite contributions that use numerical modelling to investigate landscape evolution in a broad sense, and over a range of spatial and temporal scales. We welcome studies using models to constrain one or more of: erosion rates and processes, sediment production, transport and deposition, and biotic, climatic or tectonic forcings. We also particularly wish to highlight studies that combine numerical modelling with direct Earth surface process monitoring techniques, such as topographic, field, stratigraphic, geophysical or geochronological data. Contributions using numerical models to unravel the interaction between deep processes, such as mantle dynamics, or biotic processes with topographic patterns are further encouraged. There is no geographical restriction: studies may be focused on mountain environments or sedimentary basins, or they may establish links between the two.

Recent advances in image collection, e.g. using uncrewed aerial vehicles (UAVs), and topographic measurements, e.g. using terrestrial or airborne LiDAR, are providing an unprecedented insight into landscape and process characterization in geosciences. In parallel, historical data including terrestrial, aerial, and satellite photos as well as historical digital elevation models (DEMs), can extend high-resolution time series and offer exciting potential to distinguish anthropogenic from natural causes of environmental change and to reconstruct the long-term evolution of the surface from local to landscape scale.

For both historic and contemporary scenarios, the rise of techniques with ‘structure from motion’ (SfM) processing has democratized data access and offers a new measurement paradigm to geoscientists. Photogrammetric and remote sensing data are now available on spatial scales from millimetres to kilometres and over durations of single events to lasting time series (e.g. from sub-second to decadal-duration time-lapse), allowing the evaluation of event magnitude and frequency interrelationships.

The session welcomes contributions from a broad range of geoscience disciplines such as geomorphology, cryosphere, volcanology, hydrology, bio-geosciences, and geology, addressing methodological and applied studies. Our goal is to create a diversified and interdisciplinary session to explore the potential, limitations, and challenges of topographic datasets for the reconstruction and interpretation of past and present 2D and 3D changes in different environments and processes. We further encourage contributions describing workflows that optimize data acquisition and processing to guarantee acceptable accuracies and to automate data application (e.g. geomorphic feature detection and tracking), and field-based experimental studies using novel multi-instrument and multi-scale methodologies. This session invites contributions on the state of the art and the latest developments in i) modern photogrammetric and topographic measurements, ii) remote sensing techniques as well as applications, iii) modelling technologies, and iv) data processing tools, for instance, using machine learning approaches.

The introduction of terrestrial cosmogenic nuclides as a geochronology technique provided an important quantitative tool that spurred large developments in geomorphology and it continues to be an essential tool in this field. Cosmogenic nuclides are produced primarily in the top two meters of Earth’s surface, meaning they can be used to provide important information on the exposure ages of features at the surface, like river terraces, fault scarps or glacial moraines, burial ages of deep deposits, as well as quantitative information on the rates of surface processes, like erosion or weathering. Continued technique development and creative applications both continue to expand the ways we can use cosmogenic nuclides.

This session explores both technique developments and novel applications of cosmogenic nuclides, inviting projects at any stage from early development to well-established methods applied to novel situations. We invite any type of cosmogenic nuclide technique developments, including new measurement methods, laboratory techniques, modelling, or theoretical advancements. All cosmogenic nuclide applications in any field are welcome, but we especially encourage contributions using multiple nuclides, combinations with other geochronology techniques, and other creative applications.

The Quaternary Period (last 2.6 million years) is characterized by frequent and abrupt climate swings that were accompanied by rapid environmental change. Studying these changes requires accurate and precise dating methods that can be effectively applied to environmental archives. A range of different methods or a combination of various dating techniques can be used, depending on the archive, time range, and research question. Varve counting and dendrochronology allow for the construction of high-resolution chronologies, whereas radiometric methods (radiocarbon, cosmogenic in-situ, U-Th) and luminescence dating provide independent anchors for chronologies that span over longer timescales. We particularly welcome contributions that aim to (1) reduce, quantify and express dating uncertainties in any dating method, including high-resolution radiocarbon approaches; (2) use established geochronological methods to answer new questions; (3) use new methods to address longstanding issues, or; (4) combine different chronometric techniques for improved results, including the analysis of chronological datasets with novel methods, e.g. Bayesian age-depth modeling. Applications may aim to understand long-term landscape evolution, quantify rates of geomorphological processes, or provide chronologies for records of climate change.

Debris flows are among the most dangerous natural hazards that threaten people and infrastructures in both mountainous and volcanic areas. The study of the initiation and dynamics of debris flows, along with the characterization of the associated erosion/deposition processes, is of paramount importance for hazard assessment, land-use planning and design of mitigation measures, including early warning systems. In addition, the impacts of climate change on debris-flow activity must be considered and carefully analysed, as the number of mountain areas prone to these events may increase in future.
A growing number of scientists with diverse backgrounds are studying debris flows and lahars. The difficulties in measuring parameters related to their initiation and propagation have progressively prompted research into a wide variety of laboratory experiments and monitoring studies. However, there is a need of improving the quality of instrumental observations that would provide knowledge for more accurate hazards maps and modeling. Nowadays, the combination of distributed sensor networks and remote sensing techniques represents a unique opportunity to gather direct observations of debris flows to better constrain their physical properties.
Scientists working in the field of debris flows are invited to present their recent advancements. In addition, contributions from practitioners and decision makers are also welcome. Topics of the session include: field studies and documentation, mechanics of debris-flow initiation and propagation, laboratory experiments, modeling, monitoring, impacts of climate change on debris-flow activity, hazard and risk assessment and mapping, early warning, and alarm systems.

Rockfalls, rockslides and rock avalanches are among the primary hazards in steep terrain. To better understand the processes driving rock slope degradation, mechanisms contributing to the triggering, transport, and deposition of resulting rock slope instabilities, and mitigation measures for associated hazards, we must develop insight into both the physics of intact and rock mass failure and the dynamics of transport processes.

This session aims to bring together state-of-the-art methods for predicting, assessing, quantifying, and protecting against rock slope hazards. We seek innovative contributions from investigators dealing with all stages of rock slope hazards, from weathering and/or damage accumulation, through detachment, transport and deposition, and finally to the development of protection and mitigation measures. In particular, we seek studies presenting new theoretical, numerical or probabilistic modelling approaches, novel data sets derived from laboratory, in situ, or remote sensing applications, and state-of-the-art approaches to social, structural, or natural protection measures.

The global increase in damaging landslide events is raising the attention of governments, practitioners and scientists to develop functional, reliable and (when possible) low cost monitoring strategies. Several case studies have demonstrated how a well-planned monitoring system of landslides is of fundamental importance for long and short-term risk reduction.
Today, the temporal evolution of a landslide is addressed in several ways, encompassing classical and more complex in situ measurements or remotely sensed data acquired from satellite and aerial platforms. All these techniques are adopted for the same final scope: measure landslide motion over time, trying to forecast its future evolution or at least to reconstruct its recent past. Real time, near-real time and deferred time strategies can be profitably used for landslide monitoring, depending on the type of phenomenon, the selected monitoring tool, and the acceptable level of risk.
The session follows the general objectives of the International Consortium on Landslides, namely: (i) promote landslide research for the benefit of society, (ii) integrate geosciences and technology within the cultural and social contexts to evaluate landslide risk, and (iii) combine and coordinate international expertise.
Considering these key conceptual drivers, we aim to present successful monitoring experiences worldwide based on both in situ and/or remotely sensed data. The integration and synergic use of different techniques is welcome, as well as newly developed tools or data analysis approaches (focusing on big data management). We expect case studies in which multi-temporal and multi-platform monitoring data are exploited for risk management and Civil Protection aims with positive effects in social and economic terms.

This session covers both new scientific approaches and state-of-the-art techniques for investigating landslides, including Earth Observation (EO), Geophysical Surveying (GS) and close-range Remote Sensing techniques (RS).

A series of remarkable technological progresses are driven new scientific opportunities to better understand landslide dynamics worldwide, including integrated information about rheological properties, water content, rate of deformation and time-varying changes of these parameters through seasonal changes and/or progressive slope damage.

This session welcomes innovative contributions and lessons learned from significant case studies and/or original methods aiming to increase our capability to detect, model and predict landslide processes at different scales, from site specific to regional studies, and over multiple dimensions (e.g. 2D, 3D and 4D).

A special emphasis is expected not only on the particularities of data collection from different platforms (e.g. satellite, aerial, UAV, Ground Based...) and locations (e.g. surface- and borehole-based geophysics) but also on new solutions for digesting and interpreting datasets of high spatiotemporal resolution, landslide characterization, monitoring, modelling, as well as their integration on real-time EWS, rapid mapping and other prevention and protection initiatives. Examples of previous submissions include using one or more of the following techniques: optical and radar sensors, new satellite constellations (including the emergence of the Sentinel-1A and 1B), Remotely Piloted Aircraft Systems (RPAS) / Unpiloted Aerial Vehicles (UAVs) / drones, high spatial resolution airborne LiDAR missions, terrestrial LIDAR, Structure-from-Motion (SfM) photogrammetry, time-lapse cameras, multi-temporal DInSAR, GPS surveying, Seismic Reflection, Surface Waves Analysis, Geophysical Tomography (seismic and electrical), Seismic Ambient Vibrations, Acoustic Emissions, Electro-Magnetic surveys, low-cost sensors, commercial use of small satellites, Multi-Spectral images, etc. Other pioneering applications using big data treatment techniques, data-driven approaches and/or open code initiatives for investigating mass movements using the above-described techniques will also be very welcomed.

GUEST SPEAKER (to be confirmed). Previous guest speakers include prof. J. Chambers (British Geological Survey - UK) and prof. D. Jongmans (Isterre, Université Grenoble Alpes - France).

Large rock slope instabilities have been recognised under very different geological and environmental conditions, lithological and geological domains, and on other planets. Slow to extremely fast moving, complex mass movements have been recognized, sometimes described as interrelated or as evolution stages of a same phenomenon. Many types of slope instabilities can be grouped within this broad class, presenting different types of hazard and risk. This phenomena, triggered by earthquakes, rainfall, snowmelt or deglaciation can originate relevant cascade events (e.g. tsunamis, landslide dams and overtopping, flooding).
Major aspects of these instabilities are still debated:
- distribution both on Earth and other planets;
- triggering and controlling factors and events;
- dating of initial movements and reactivation episodes;
- style and state of past and present activity;
- passive and/or active control of structural features;
- possible displacement evolution and modelling;
- hazard assessment inclusive of cascade events;
- influence of anthropogenic factors and effects on structures;
- role on the erosional and sediment yield regime;
- technologies for monitoring and warning systems, and the interpretation of monitoring data.
Study of these instabilities is interdisciplinar and multidisciplinar. Site investigation, geophysical survey and dating techniques can support geometrical and geomechanical characterization, recognition of activity episodes, monitoring data interpretation for warning thresholds. Different hydrologic boundary conditions and hydrochemistry are involved, both at failure and during reactivations. Modelling is a key element for understanding and evaluating instability and failure (initiation, propagation), triggering (rainfall, seismicity, volcanic eruption, deglaciation), collapse, and secondary failures as well as the effect on the local and regional geomorphological evolution (e.g. sediment yield). Cascade-like events are definitively a possible result and advanced modeling techniques are requested for studying these phenomena and for reliable and robust hazard zonation. Size and evolution of large instabilities require major efforts when assessing the potential impacts on structures and infrastructures, and human activities enforcing a deep understanding and modeling. On the other hand, instabilities on other planets can support indirect environmental and geomechanical characterization.

Many natural hazards can interact with each other and lead to or exacerbate the effects of additional catastrophic events, such as landslides following earthquakes, floods following snow-avalanches or landslides and floods induced simultaneously by heavy rainfall. According to the 2019 IPCC special report, the frequency and magnitude of mountain hazards, i.e. snow avalanches, floods due to glacier lake outburst (GLOF), flash-floods, rockfalls and landslides, are projected to increase in a scale never seen, potentially impacting new locations and/or occurring in different seasons than previously. In combination with growth in the population and economy, this changing landscape of mountain hazards will dramatically increase the risk to local populations, leading to growing economic damages in mountainous regions. Prediction of the areas threatened by such processes are a key part of hazard assessment in mountainous regions. Whatever the material transported (debris, snow, etc.), the mass wasting process involves determining the initiation mechanisms, initial volume, physical transport, and probable entrainment processes and as well as deposition mechanisms. Because of the number of scientific disciplines needed to solve it, there is a substantial benefit from inter- and transdisciplinary research. This session aims to serve as a forum, allowing discussion and debate on the future development of the field. In particular, we encourage presentations ranging from innovative monitoring and documentation methods related to hazard processes in mountain settings to studies focusing on an improved mechanical understanding of the physical processes involved, including modelling, laboratory research, and theoretical studies.

Many regions worldwide are coping with the climatic global change, which is modifying the water cycle and is increasing the occurrence of extreme hydro-meteorological events. Floods and landslides across a territory could increase significantly respect to actual and past scenarios, causing a modification of the susceptibility of a region and of the frequency of natural hazards.
The use of techniques able to monitor and to improve the prediction of these phenomena at different scales and in scarcely instrumented regions is fundamental. Soil moisture and rainfall estimates measured through remote sensing techniques can furnish reliable and widespread data at different scales. For satellite rainfall measures, state-of-the-art products cover time series of tens of years (e.g., TRMM Multisatellite Precipitation Analysis, Global Precipitation Measurement, EUMETSAT). Regarding soil moisture, different products can bring reliable measurements from a local/landscape to continental scales (e.g., SMMR, AMSR2, SMOS, SMAP, Metop/ASCAT, Sentinel). Innovative products, as soil moisture derived rainfall, allow to retrieve rainfall from different satellite soil moisture products or integrating field measurements of precipitation. Thanks to the improvement of the spatial and temporal resolutions of all of these products, they could become a fundamental tool also for early warning system strategies.
This session aims to collect and present researches concerning the most recent progress on the use of soil moisture and rainfall data from remote sensing for the monitoring and the prediction of landslides and floods. Those phenomena can cause hazards and risks towards population and anthropic elements. We encourage presentations related to:
• inter-comparison and inter-validation between land surface models, remote sensing approaches and in-situ validation networks;
• evaluation and trend analysis of soil moisture or rainfall satellite time series for monitoring landslides or floods and for identifying their possible triggering conditions;
• implementation of satellite measures of rainfall and soil moisture in physically-based or data-driven methods for the prediction of landslides and floods;
• use of remote sensing products of soil moisture and rainfall in early warning system tools;
• use of remote sensing products for investigating the effects of climatic global changes on the susceptibility and hazards towards landslides and floods.

Soil is the largest carbon (C) reservoir in terrestrial ecosystems with twice the amount of atmospheric C and three times the amount in terrestrial vegetation. Carbon related ecosystem services include retention of water and nutrients, promoting soil fertility and productivity and soil resistance to erosion. In addition, changes in the soil C can have strong implications for greenhouse gas emissions from soil with implications in environmental health.

Drivers controlling C pools and its dynamics are multiple (e.g. land use/vegetation cover, climate, texture and bedrock, topography, soil microbial community, soil erosion rates, soil and other environment management practices, etc. ) and some of them are mutually interacting. Also, rate of net soil C loss can be high in some environments due to both climatic constrains or management. Thus, investigation of C dynamics should be addressed with regards to the climate change and climatic extreme events to provide a better understanding of carbon stabilization processes and thus support decision making in soil management and climate adaptation strategies.

The present session highlights the importance of soil C changes, and the interaction among the mechanisms affecting C concentration and stocks in soil. Discussion about the proxies to measure and model C stocks, with special emphasis to cropping systems and natural/semi-natural areas, is encouraged. These proxies should be approached at varying the availability of soil and environment information, including, e.g., soil texture, rainfall, temperature, bulk density, land use and land management, or proximal and remote sensing properties. Studies presented in this session can aim to a wealth of aims, including soil fertility, provision of ecosystem services, and their changes, and the implication for economy, policy, and decision making.

Types of contribution appreciated include, but are not limited to, definitive and intermediate results; project outcomes; proposal of methods or sampling and modelling strategies, and the assessment of their effectiveness; projection of previous results at the light of climate change and climatic extremes; literature surveys, reviews, and meta-analysis. These works will be evaluated at the light of the organisation of a special issue in an impacted journal

Well-designed experiments, measurement and modelling approaches are crucial methodologies in Soil Science, Geomorphology and Hydrology.

Depending on the specific research topic, a great variety of tempo-spatial scales is addressed. From raindrop impact and dust emission on field scale to the shaping of landscapes.

This virtual PICO-Session presents experiments, measurements and modelling approaches in the laboratory and the field investigating processes and quantities of soil detachment by wind, splash erosion and subsurface particle transport highlighting the role of vegetation, land use and harmonisation of experiments.

Dissolution, precipitation and chemical reactions between infiltrating fluid and rock matrix alter the composition and structure of the rock, either creating or destroying flow paths. Strong, nonlinear couplings between the chemical reactions at mineral surfaces and fluid motion in the pores often leads to the formation of intricate patterns: networks of caves and sinkholes in karst area, wormholes induced by the acidization of petroleum wells, porous channels created during the ascent of magma through peridotite rocks. Dissolution and precipitation processes are also relevant in many industrial applications: dissolution of carbonate rocks by CO2-saturated water can reduce the efficiency of CO2 sequestration, mineral scaling reduces the effectiveness of heat extraction from thermal reservoirs, acid rain degrades carbonate-stone monuments and building materials.

With the advent of modern experimental techniques, these processes can now be studied at the microscale, with a direct visualization of the evolving pore geometry. On the other hand, the increase of computational power and algorithmic improvements now make it possible to simulate laboratory-scale flows while still resolving the flow and transport processes at the pore-scale.

We invite contributions that seek a deeper understanding of reactive flow processes through interdisciplinary work combining experiments or field observations with theoretical or computational modeling. We seek submissions covering a wide range of spatial and temporal scales: from table-top experiments and pore-scale numerical models to the hydrological and geomorphological modelling at the field scale. We also invite contributions from related fields, including the processes involving coupling of the flow with phase transitions (evaporation, sublimation, melting and solidification).

The transfer of sediments and associated contaminants play an important role in catchment ecosystems as they directly influence water quality, habitat conditions and biogeochemical cycles. Contaminants may include heavy metals, pesticides, nutrients, radionuclides, and various organic, as well as organometallic compounds. The environmental risk posed by sediment-bound contaminants is largely determined by the sources and rate at which sediments are delivered to surface water bodies, the residence time in catchments, lakes and river systems as well as biogeochemical transformation processes. However, the dynamics of sediment and contaminant redistribution is highly variable in space and time due to the complex non-linear processes involved. This session thus focuses on sources, transport pathways, storage and re-mobilization, and travel times of sediments and contaminants across temporal and spatial scales as well as their impact on catchment and freshwater ecosystems.

This session particularly addresses the following issues:
- Delivery rates of sediments and contaminants from various sources (i.e. agriculture, urban areas, mining, industry or natural areas);
- Transport, retention and remobilization of sediments and contaminants in catchments and river reaches;
- Modelling of sediment and contaminant transport on various temporal and spatial scales;
- Biogeochemical controls on contaminant transport and transformation;
- Studies on sedimentary processes and morphodynamics, particularly sediment budgets;
- Linkages between catchment systems and lakes, including reservoirs;
- Analysis of sediment archives to appraise landscape scale variations in sediment and contaminant yield over medium to long time-scales;
- Impacts of sediments and contaminants on floodplain, riparian, hyporheic and other in-stream ecosystems;
- Response of sediment and contaminant dynamics in catchments, lakes and rivers to changing boundary conditions and human actions.

Water and sediments interact at different spatial and temporal scales in freshwaters promoting the development of highly dynamic systems. Erosion, transport and sedimentation are vital processes that shape river morphology. These dynamic processes, in turn, are essential to provide a mosaic of diverse habitat patches for aquatic species and to freshwater ecosystems functioning.
Anthropogenic activities such as flow regulations or dams lead to fragmentation and ecosystem degradation, interfering with natural hydro-morphodynamics and affecting aquatic ecology. In Europe, large efforts are set to restore disturbed river sections to meet the goals of a good ecological status, set by the Water Framework Directive. Experience to date indicates that integrating both physical and ecological processes in river restoration efforts is critical to freshwater ecosystems conservation. In this context, the interdisciplinary field of Ecohydraulics represents the link between abiotic components (e.g. hydrology, hydraulics, geomorphology) and riverine biota (e.g. vegetation, fish, macroinvertebrates). Advances in this field of research are therefore paramount to make future management decisions in freshwater systems.
This session aims at integrating the core research disciplines forming Ecohydraulics, from hydrology, hydraulics, fluvial geomorphology, and biology, but also social aspects to ensure a holistic assessment of rivers, lakes and reservoirs, and to enable the implementation of sustainable restoration measures.
We welcome both fundamental and applied research, presenting approaches at different spatio-temporal scales. They may include holistic tools and methods to improve the assessment, prediction and management of restoration and mitigation measures in aquatic systems, with a focus on the hydrological, fluvial geomorphological, and biological interactions.
Contributions may refer, but are not restricted, to:
- sediment transport, fluvial dynamics and sediment budgets in rivers
- risk analysis and mitigation in fluvial systems
- reservoir sedimentation: processes and management
- large wood and microplastic in aquatic systems
- nature-compatible river engineering and river development
- nature based solutions
- revitalization of river systems (from successful studies to failures in restoration)
- tools and methods (concepts, measurements, monitoring, modelling) to understand the interactions between fluvial processes and their biological responses

Complex hydro-morphological processes, such as sediment erosion, transport, deposition or fan development, affect open water environments, including rivers, estuaries as well as lakes and reservoirs. Consequently, many research tasks as well as practical applications rely on the correct prediction of these processes. During the last decades, numerical models have become a powerful tool in the research fields of hydraulic engineering and geosciences to simulate these hydro-morphological processes. With improved algorithms as well as an ever growing computational power, it became feasible to simulate the interaction of water, sediments and air with high resolution in space and time. In addition, with an increasing quantity and quality of validation data from laboratory experiments and field studies, numerical models are continuously enhanced so that many good examples of sediment transport modelling offer new insights in multiphase processes, e.g. dune development, river bed armoring or density driven transport. Hence, new generations of numerical modelling techniques open up the possibility to explore numerous outstanding research questions related to hydro-morphologic processes.
The main goal of this session is to bring together scientists and engineers, who develop, improve, and apply numerical models of multiphase flows for sediment transport in open water environments. We invite contributions that deal with numerical modelling from small-scale, such as bed structure development, to large-scale interactions, such as long-term development of hydro-morphological processes in rivers, lakes, reservoirs and estuaries.
Contributions may refer, but are not restricted, to:
• Entrainment processes of sediments (from cohesive sediments to armoured river beds)
• Bed load and suspended sediment transport processes (including flocculation processes)
• Simulation of sediment management including planning, operation and maintenance of hydro power plants
• Design and evaluation of restoration measures to revitalize rivers
• Navigation issues, such as sediment replenishment, dredging and erosion induced by ship generated waves
• Flood related issues of long term effects of morphological bed changes on flood security
• Eco-hydraulics such as flow – sediment – vegetation interaction
• Density driven transport

The production, transport, and deposition of sediment govern the fluxes and distribution of solid mass on the surface of the Earth. The frequency, magnitude, and physical and chemical properties of these fluxes are initially controlled by external forcing (climate and tectonics) before being modulated by the complex interplay of surface processes. Understanding the interplay of these processes and how they are affected by external forcing is vital to understanding how sediment fluxes have changed through time.
A growing body of studies continues to develop a process-based understanding of the coupling between climate, tectonics, and the production and transport of solids across catchments. Important insights into sediment recycling and residence time have been provided by recent advances in geochemical and geophysical techniques, highlighting the dynamic nature of sediment transport. However, many challenges remain including; (1) fully quantifying the temporal- and spatial scales of sediment transport, (2) assessing the importance of large and infrequent events in controlling erosion and sediment transport and, (3) bridging the gap between short- and long-term or small- and large-scale records of sediment production and fluxes.
In this session we welcome field-based, experimental, and modelling studies, that (1) constrain mechanisms, rates, and scales of erosion, transport, and deposition processes, (2) analyse the influence of internal and external forcing on these processes, (3) investigate the propagation of geochemical or physical signals across the earth surface (such as changes in sedimentary fluxes, grain size distributions, cosmogenic nuclide concentrations).
Contributions across all temporal and spatial scales are welcome.

Invited presentation : Sebastien Carretier - Delayed sedimentary grains

Soil erosion is a major global soil degradation threat to land, freshwater and oceans. Scientific understanding of all erosional physical processes controlling soil detachment, transportation, and deposition is vital when developing methods and conservation alternatives to minimize the impacts associated with soil degradation.

This session will discuss the State-of-the-Art of the latest soil erosion measurements, monitoring and modelling techniques in agriculture, forest and rangelands. Our main objective is to scientifically discuss soil erosion but also to explore/present solutions that may help farmers and policy makers; supporting the ongoing activities aiming at achieving the SDG Target 15.3 land degradation neutral world by 2030 and the upcoming UN Decade on Ecosystem Restoration (2021-2030). This session will also discuss recent studies supporting improved understanding of gully and rill erosional physical processes, their impact locally, their off-site effects on sedimentation, and subsequent development of mitigation strategies.

Landslides are ubiquitous geomorphological phenomena with potentially catastrophic consequences. In several countries, landslide mortality can be higher than that of any other natural hazard. Predicting landslides is a difficult task that is of both scientific interest and societal relevance that may help save lives and protect individual properties and collective resources. The session focuses on innovative methods and techniques to predict landslide occurrence, including the location, time, size, destructiveness of individual and multiple slope failures. All landslide types are considered, from fast rockfalls to rapid debris flows, from slow slides to very rapid rock avalanches. All geographical scales are considered, from the local to the global scale. Of interest are contributions investigating theoretical aspects of natural hazard prediction, with emphasis on landslide forecasting, including conceptual, mathematical, physical, statistical, numerical and computational problems, and applied contributions demonstrating, with examples, the possibility or the lack of a possibility to predict individual or multiple landslides, or specific landslide characteristics. Of particular interest are contributions aimed at: the evaluation of the quality of landslide forecasts; the comparison of the performance of different forecasting models; the use of landslide forecasts in operational systems; and investigations of the potential for the exploitation of new or emerging technologies e.g., monitoring, computational, Earth observation technologies, in order to improve our ability to predict landslides. We anticipate that the most relevant contributions will be collected in the special issue of an international journal.

The present context of accelerated changes in both climate and land use imposes an unprecedent pressure on a number of vulnerable ecosystems including wetlands, forests and rangelands, in which vegetation closely interacts and coevolves with soils and landforms. Complex interactions between climate, soils and biotic factors are involved in the development of landform-soil-vegetation feedbacks and play an important role in making ecosystems resilient to disturbances. In addition, large shifts in the distribution of vegetation and soils are associated with losses of ecosystem services (including carbon capture), frequently involving thresholds of ecosystem stability and nonlinear responses to both human and climatic pressures. This session will focus on ecogeomorphological and ecohydrological aspects of landscapes (including their connectivity), conservation of soil resources, and the restoration of ecosystem services and functions. We welcome theoretical, modelling, and empirical studies addressing the distribution of vegetation and coevolving soils and landforms, and particularly, contributions with a wide appreciation of the soil erosion-vegetation relationships that rule the formation of landscape-level spatial organization. We also welcome studies describing the implications of these spatial patterns of soils and vegetation for the resilience and stability of ecosystems under the pressure of climate change and/or human disturbances.

Wildfires are a global phenomenon responsible for tremendous environmental, social and economic losses, which combined with land abandonment, absence of appropriate land management, and urban planning, are expected to exacerbate land degradation and deteriorate the ecosystem services.
But now, wildfires are becoming a persistent threat as shown by the fire risk increase as a consequence of a warmer and drier climate, demanding from the scientific community novel tools for integrated post-fire land management and impact mitigation. This research urges the attention of researchers, stakeholders and decision-makers all over the world since wildfire impacts on soils and ecosystems are severely affecting ecosystem services supply such as raw material and water provisioning, carbon storage, erosion and flood control, and habitat support, which are essential for human life on earth.
The aim of this session is to join researchers that study the effects of wildfires on ecosystems from wildfire prevention to post-fire mitigation. We warmly invite studies that approach by means of laboratory, field experiments, and/or numerical modeling, the following subjects:
i. prescribed and/or experimental fires;
ii. fire severity and burn severity;
iii. fire effects on vegetation, soils and water;
iv. post-fire hydrological and erosive response;
v. post-fire management and mitigation;
vi. , and socio-economic studies on post-fire land management.

Obtaining quantitative information on the spatial pattern of soil redistribution during storms and on the spatial sources supplying sediment to rivers is required to improve our understanding of the processes controlling these transfers and to design effective control measures. It is also crucial to quantify the transfer or the residence times of material transiting rivers along the sediment cascade, and to reconstruct the potential changes in sources that may have occurred at various temporal scales. During the last few decades, several sediment tracing or fingerprinting techniques have contributed to provide this information, in association with other methods (including soil erosion modelling and sediment budgeting). However, their widespread application is limited by several challenges that the community should address as priorities.
We invite specific contributions to this session that address any aspects of the following:
• Developments of innovative field measurement and sediment sampling techniques;
• Soil and sediment tracing techniques for quantifying soil erosion and redistribution;
• Sediment source tracing or fingerprinting studies, using conventional (e.g. elemental/isotopic geochemistry, fallout radionuclides, organic matter) or alternative (e.g. colour, infrared, particle morphometry) approaches;
• Investigations of the current limitations associated with sediment tracing studies (e.g. tracer conservativeness, uncertainty analysis, particle size and organic matter corrections);
• Applications of radioisotope tracers to quantify sediment transit times over a broad range of timescales (from the flood to the century);
• The association of conventional techniques with remote sensing and emerging technologies (e.g. LiDAR);
• Integrated approaches to developing catchment sediment budgets: linking different measurement techniques and/or models to understand sediment delivery processes.

Denudation and land cover change are of high relevance for Earth surface and landscape dynamics and the transfer of solutes and sediments from headwater systems through main stem of drainage basin systems to the world oceans. Denudational hillslope and fluvial processes, associated source-to-sink fluxes and sedimentary budgets are controlled by a range of environmental drivers and anthropogenic activities, exacerbated by the consequences of climate change.
The better understanding of possible effects of ongoing and accelerated environmental changes on present-day denudation requires systematic and quantitative studies on the actual drivers of denudational and land cover processes. Only if we have an improved quantitative knowledge of drivers and rates of contemporary denudational hillslope and fluvial processes as well as of the sediment and hydrological connectivity across a range of different spatio-temporal scales and selected climatic zones, the possible effects of anthropogenic impacts and natural disturbances on terrestrial landscape systems could be detected and better assessed. Scientific focus is on the geomorphic effects and consequences of increased frequencies, durations and intensities of dry spells, droughts, fires, storms, extreme rainfall events and floods, of accelerated permafrost thawing, glacier retreat, earthquakes, and of mineral exploration, mining exploitation and infrastructure constructions.
Special attention should be given to selected cold climate, temperate, arid and tropical regions that are expected to react particularly sensitive to ongoing and accelerated environmental changes.
This session includes contributions from geomorphology, hydrology, agricultural science, soil science, geotechnics and environmental engineering. The presentations cover a wide range of different spatial scales, from hillslope and small headwater systems to large drainage basin systems. The session brings together and discusses a wide range of advanced techniques and methods of data collection and generation, including field-based, laboratory-based, remotely-sensed and dating techniques together with various approaches and methods of data analysis and geomorphologic modelling.
This session is co-organized by the IAG Working Group on Denudation and Environmental Changes in Different Morphoclimatic Zones (DENUCHANGE).

Mountain belts are characterized by the fastest rates of physical erosion and chemical weathering around the world, making them one of the best places to observe sediment production (e.g. erosion, weathering) and transport processes. In these settings, varied processes such as rockfall, debris flow, hillslope failure, glacial and periglacial erosion, fluvial erosion, transport and deposition, and chemical weathering operate, often simultaneously, over a wide range of temporal and spatial scales.

As a result, tracking the interactions between denudation, climatic forcing, tectonic activity, vegetation and land use is complex. However, these feedbacks affect both long- and short-term natural surface processes, landscape development, and human interactions with the environment. Many of these processes also pose serious threats to the biosphere, mountain settlements and infrastructure. Therefore, understanding and quantifying rates of erosion, weathering, and deposition within mountain landscapes is a challenging, but crucial research topic in Earth surface processes.

We welcome contributions that (1) investigate the processes of production, mobilisation, transport, and deposition of sediment in mountain landscapes, (2) explore feedbacks between erosion and weathering due to natural and anthropogenic forcings, and (3) consider how these processes contribute to natural hazards specific to mountain landscapes. We invite presentations that employ observational, analytical or modeling approaches in mountain environments across a variety of temporal and spatial scales. We particularly encourage early career scientists to apply for this session.

Hydro-geomorphic connectivity has emerged as a significant conceptual framework for understanding the transfer of surface water and materials (e.g., sediment, plant propagules, and nutrients) through landscapes. The concept has had particular success in the field of catchment hydrology and fluvial geomorphology, but has also been employed in, for example, studies of soil erosion and hydrochory, and in neurosciences and social sciences. Connectivity as applied in various disciplines can be a transformative concept in understanding complex systems, allowing analyses of how such systems behave in terms of scaling, catastrophic/phase transitions, critical nodes, emergence and self-organization. However, recent research also highlights the widespread nature of natural longitudinal disconnectivity in river systems, such as beaver dams, log jams, lakes and wetlands. These and other forms of natural disconnectivity can have large spatial and temporal implications on ecological, geomorphic, hydrological and biogeochemical processes through buffering water and material fluxes. We aim to create a diverse interdisciplinary session that reflects a broad range of research seeking to illustrate the role of connectivity on various spatial scales as well as implications of and temporal and spatial variability of disconnectivity. We hope to use the session to develop a discussion of the dual roles of connectivity and disconnectivity to generate a basis for an integrated framework to be applied across the sciences in hydro-geomorphic systems and for managing complex systems and guiding river restoration.

Terrestrially derived sediments in sedimentary archives are regularly used to reconstruct past climatic or tectonic conditions. Sediments are generally produced in mountainous areas and transported via sediment routing systems (SRS) to a zone of final deposition. Environmental reconstructions are based on the assumption that perturbations in climatic or tectonic conditions generate signals within the transported sediment. However, experimental and numerical studies have shown that not all signals are faithfully transmitted, but can be modified, buffered or even lost during transport along the SRS. Oftentimes, it is stated that signals can only be faithfully transmitted if the response time of the SRS is short relative to the period of the forcing. However, individual signals in response to a perturbation can already be generated early during the transient response phase. Hence, signals can be transported through and stored within the SRS as a measurable change of a sedimentary parameter (or ‘proxy’) even before the SRS has returned to steady state conditions, i.e. before the characteristic response time has passed. Therefore, it is important to gain quantitative insight into the time scales required for a portion of sediment, which carries a change in proxy information, to travel to the sedimentary archive.
We seek to bring together new concepts and results on sedimentary proxy generation during environmental changes, as well as proxy transport and archiving during the transient state of the SRS. We welcome studies addressing, but not limited to, the following themes:

• Numerical & analog modeling of proxy generation, transport and deposition along sediment routing systems
• Field studies of proxy generation, transport and deposition along sediment routing systems
• Comparison of proxy propagation measured on different grain-size ranges
• Tracing of environmental signals through a system
• Novel proxy methodologies
• The connectivity of sediment routing systems and proxy transport

This session will be supported by a special issue in Frontiers in Earth Sciences.

Fluvial systems cover much of the Earth’s surface; they convey water, sediments, and essential nutrients from the uplands to the sea, intermittently transferring these materials from the river channel to the adjacent floodplain. The routing of sediment and water through the channel network initiates complex process-form interactions as the river bed and banks adjust to changes in flow conditions. Despite their ubiquity, little is known about the landform-driven morphodynamic interactions taking place within the channel that ultimately determine patterns of sedimentation and changes of channel form. Furthermore, an understanding of how these process-form interactions scale with the size of the fluvial system is also currently lacking. Recent technological and methodological advances now afford us the opportunity to study and to quantify these process-form interactions in detail across a range of spatial and temporal scales.

This session aims to bring together interdisciplinary researchers working across field, experimental, and numerical modelling approaches who are advancing methods and providing new insights into: (i) sediment transport and morphodynamic functioning of fluvial systems, (ii) evaluating morphological change at variable spatial and temporal scales, such as at event vs. seasonal scales, and (iii) investigating the sedimentology of these river systems. We particularly welcome applications which investigate the morphodynamic response of fluvial systems in all types and sizes and we specifically would like to encourage submissions from early career researchers and students.

Rivers in most parts of the world are experiencing ever strong disturbances of humans, which, in combination with climate change, have made river systems adjust their morphologies and boundaries significantly, resulting in a wide range of degradation in aquatic habitats, extinction of fish species, loss of flood-retaining areas etc. To minimize these negative effects, it is necessary to provide convincing predictions of the adjustments of river systems to the public and decision makers. However, rivers are dynamic systems that are too variable and behave in very complex manners. A lot of theoretical and numerical modelling frameworks have been proposed and practiced for quantitatively predicting the self-adjustments of river morphologies over the last several decades, and it is necessary to evaluate the physical/empirical bases and practical applicabilities of available theoretical and modelling frameworks so as to advance theory and modelling of river systems. This session aims to explore advances in modelling of river systems responding to environmental change, and identify possible links between simulated or projected changes, and the erosion mechanics that are in part responsible for these changes.

Transport of sediments in geophysical flows occurs in mountainous, fluvial, estuarine, coastal, aeolian and other natural or man-made environments on Earth and has been shown to play important formative roles in planets and satellites such as Mars, Titan, and Venus. Understanding the motion of sediments is still one of the most fundamental problems in hydrological and geophysical sciences. Such processes can vary across a wide range of scales - from the particle to the landscape - which can directly impact both the form (geomorphology) and, on Earth, the function (ecology and biology) of natural systems and the built infrastructure surrounding them. In particular, feedback between flow and sediment transport as well as interparticle interactions including size sorting are a key processes in surface dynamics, finding a range of important applications, from hydraulic engineering and natural hazard mitigation to landscape evolution and river ecology.

Specific topics of interest include (but are not restricted to):

A) particle-scale interactions and transport processes:
-mechanics of entrainment and disentrainment (for fluvial and aeolian flows)
-momentum (turbulent impulses) and energy transfer between turbulent flows and particles
-upscaling and averaging techniques for stochastic transport processes
-interaction among grain sizes in poorly sorted mixtures, including particle segregation

B) reach-scale sediment transport and geomorphic processes
-bedform generation, evolution and disintegration dynamics (e.g. for dunes and other formations)
-discrete element modelling of transport processes and upscaling into continuum frameworks
-derivation and solution of equations for multiphase flows (including fluvial and aeolian flows)
-shallow water hydro-sediment-morphodynamic processes

C) large-scale, highly unsteady and complex water-sediment flows:
-flash floods, debris flows and landslides due to extreme rainfall
-natural and build dam failures and compound disasters (due to landslides, debris flow intrusion and downstream flooding)
-reservoir operation schemes and corresponding fluvial processes
-design of hydraulic structures such as fish passages, dam spillways, also considering the impact of sediment
-dredging, maintenance and regulation for large rivers and navigational waterways

Tsunamis and storm surges pose significant hazards to coastal communities around the world. Geological investigations, including both field studies and modelling approaches, significantly enhance our understanding of these events. Past extreme wave events may be reconstructed based on sedimentary and geomorphological evidence from low and high energy environments, from low and high latitude regions and from coastal and offshore areas. The development of novel approaches to identifying, characterising and dating evidence for these events supplements a range of established methods. Nevertheless, the differentiation between evidence for tsunamis and storms still remains a significant question for the community. Numerical and experimental modelling studies complement and enhance field observations and are crucial to improving deterministic and probabilistic approaches to hazard assessment. This session welcomes contributions on all aspects of paleo-tsunami and paleo-storm surge research, including studies that use established methods or recent interdisciplinary advances to reconstruct records of past events, or forecast the probability of future events.

The ocean floor hosts a tremendous variety of forms that reflect the action of a range of tectonic, sedimentary, oceanographic and biological processes at multiple spatio-temporal scales. Many such processes are hazards to coastal populations and offshore installations, and their understanding constitutes a key objective of national and international research programmes and IODP expeditions. High quality bathymetry, especially when combined with sub-seafloor and/or seabed measurements, provides an exciting opportunity to integrate the approaches of geomorphology and geophysics, and to extend quantitative geomorphology offshore. 3D seismic reflection data has also given birth to the discipline of seismic geomorphology, which has provided a 4D perspective to continental margin evolution.

This interdisciplinary session aims to examine the causes and consequences of geomorphic processes shaping underwater landscapes, including submarine erosion and depositional processes, submarine landslides and canyons, sediment transfer and deformation, volcanic activity, fluid migration and escape, faulting and folding, and other processes acting at the seafloor. The general goal of the session is to bring together researchers who characterise the shape of past and present seafloor features, seek to understand the sub-surface and surface processes at work and their impacts, or use bathymetry and/or 3D seismic data as a model input. Contributions to this session can include work from any depth or physiographic region, e.g. oceanic plateaus, abyssal hills, mid-ocean ridges, accretionary wedges, and continental margins (from continental shelves to abyss plains). Datasets of any scale, from satellite-predicted depth to ultra high-resolution swath bathymetry, sub-surface imaging and sampling, are anticipated.

This session is organised by the IAG Submarine Geomorphology Working Group.

Coastal wetland ecosystems, such as salt marshes, mangroves, seagrass beds and tidal flats, are under increasing pressure from natural and anthropogenic processes shifting climatic conditions, and are declining in area and habitat quality globally. These environments provide numerous ecosystem services, including flood risk mediation, biodiversity provision and climate change mitigation through carbon storage. Hence, the need to get a deeper understanding of processes and interactions in these environments, and how these may be altered by climate change has never been greater. This is the case for ‘managed’, restored wetlands and natural systems alike.
This session will bring together studies of coastal wetland ecosystems across climates and geomorphic settings, to enhance the understanding of ecosystem service provisioning, interactions between hydrodynamics, sediment and ecology, and identify best future management practices. Studies of all processes occurring within coastal wetlands are invited. This includes, but is not exclusive to, sediment dynamics, hydrology, hydrodynamics, biogeochemistry, morphological characterisation, geotechnical analysis, bio-morphodynamics, ecological change and evolution, impact of climate change, sea level rise, anthropogenic and management implications. Multidisciplinary approaches across spatial and temporal scales are encouraged, especially in relation to global climate change. This session aims to enhance our understanding of basic processes governing coastal wetland dynamics and to propose sustainable management solutions for contemporary environmental pressures.

Low-lying coastal areas can be an early casualty to the acceleration of sea-level rise, especially where enhanced by land subsidence. An ever increasing number of studies indicates that land subsidence due to natural and anthropogenic causes has induced damage to wetland ecosystems in many countries worldwide, and increased flooding hazard and risk. Coastal subsidence causes include excessive groundwater extraction from aquifers, peat oxidation due to surface water drainage through land reclamation, urbanization and agricultural use, as well as sediment starvation due to construction of dams and artificial levees. Contrary to the global processes behind sea-level rise, natural and anthropogenic coastal subsidence is primarily a local phenomenon, and causes and severity may vary substantially from place to place.

The combination of geological and historical measurements with remote sensing data is required to understand all drivers of coastal vertical land motion and the contributions to past, present, and future subsidence. Understanding coastal subsidence requires multidisciplinary expertise, including measuring and modeling techniques from geology, geodesy, natural hazards, oceanography, hydrogeology, and geomechanics. In this session, we aim to bring together all the involved disciplines. We invite contributions on all aspects of coastal subsidence research and applications, including recent advances on: i) measurement through ground-based, aerial and satellite remote sensing techniques, ii) numerical models and future projections, iii) their applicability to distinguish between the different drivers contributing to land subsidence, and iv) quantification of coastal hazards associated with relative sea-level rise. In particular, efforts towards characterizing human intervention on coastal vertical land motion are welcomed.

Coasts worldwide face a great variety of environmental impacts as well as increased anthropogenic pressures of coastal zone urbanization and rapid population growth. Over the last decade coastal erosion has emerged as a widespread problem that causes shoreline retreat and irreversible land losses. The attempts of managers and other stakeholders to cope with erosion using different types of hard engineering methods may often aggravate this problem, damaging natural landscape and coastal ecosystems in unexpected and unpredicted ways. Other negative impacts of human activities on littoral environments are chronic and punctual pollution of beach and coastal sediments with associated health risks for human beings. Chronic pollution is often observed in coastal areas close to factories, industries and human settlements - because of waste water discharges, punctual contamination is often linked to beach oiling.
The session gives priority to the subjects of coastal geomorphology: evolution of coastal landforms, coastal morphodynamics, coastline alterations and various associated processes in the coastal zone, e.g. waves and sediment drift, which shape coastal features and cause morphological changes. Contributions to this session will focus on the mechanisms responsible for coastal erosion and shoreline behaviour (advance or retreat) and will address the many natural and human factors involved. The topics may include work on predictions of shoreline change and discussions on the effects of human activities and their continuing contribution to coastal changes. The session will also cover submissions on coastal vulnerability to the combined effects of natural and human-related hazards, any type of coastal and environmental sensitivity classifications, and risk assessments. Globally, coastal dunes are seriously threatened as people tend to modify landforms and habitats through their actions and regulations, and the session invites also studies on natural and human-induced geomorphological changes of sand dunes, and recent projects and examples of dune eco-restoration and re-building.
Last, but not the least, studies related to Marine Spatial Planning (MSP), including Integrated Coastal Management (ICM), are also welcome. For any MSP and ICM, it is essential to consider the dynamics across the land-sea interface, i.e. the Land-Sea Interactions (LSI) that involve both natural processes and the impact of human activities.

Under the umbrella of the INQUA Coastal and Marine Processes Commission, (www.inqua.org/commissions/cmp) the Neptune project was launched early 2020 as a working group for Early Career Scientists aiming to develop multidisciplinary techniques to analyze and reconstruct past landscapes.
Special attention is paid to the technological content, considering that the recent technological innovation applied to geo-acoustic and remote sensing methods opened numerous new possibilities of high-resolution mapping of wide coastal areas, seabed morphologies, and underwater archaeological structures.
The project is placed in the context of regional and local scale studies on coastal landscape changes both on- and offshore, from the back-shore zone to the continental shelf.
Furthermore, such information is crucial to assess the potential impact of relative sea-level rise and to prepare the adaptation of coastal communities threatened by climate change. We focus our attention on the Mediterranean basin, but we are open to researchers working in other geographic areas to provide a broader perspective on the open questions.
In this session at the EGU 2021, we call for contributions applying modern methodological approaches in the coastal zone investigating shifting shorelines, sea-level changes, and aiming at reconstructing landscapes.

Detailed maps of the seabed, portraying the spatial distribution of geomorphic features, substrates, and habitats, are used for a wide range of environmental, scientific, and economic maritime applications. These maps are the scientific basis for informed ocean and coastal management at local to regional scales, and thereby provide cornerstones to national and international nature-conservation policies. Fundamental to seabed mapping are acoustic remote-sensing technologies, which include singlebeam and multibeam echosounders, along with sidescan, interferometric, and synthetic-aperture sonars. These are deployed on various platforms including crewed and uncrewed surface and underwater vessels. In relatively shallow and transparent waters, optical methods such as aircraft and satellite-based remote sensing and LiDAR are employed with increasing success. Innovative processing and classification software, image analysis, machine and deep-learning applications are advancing developments in seabed-recognition techniques, the application of which is increasing the resolution and confidence in the maps produced. We welcome submissions that provide insights into new developments, methods, and results in the field of seabed mapping and classification. This session also aims to showcase a range of applications for these datasets.

Worldwide over 500 million people live in low-lying coastal deltaic areas, existential to global food security, economic activities and biodiversity. Despite climate change severity at global scale, in many densely populated deltas its effect is currently evidently dwarfed by anthropogenic pressures in the river basin such as river flow modifications, damming and the overexploitation of the natural resources groundwater or sand, as well as profound land use changes and process such as urbanisation. As a result, many major deltas rapidly sink and shrink because of accelerated land subsidence and erosion rates. This increases relative sea-level rise and vulnerability to floods and storms, increases salinization of surface and groundwater and reduces freshwater availability, leading to significant losses in biodiversity, habitat degradation, reduced agricultural and economic productivity. A fundamental change in management approach is required to address these trends and challenges to sustain deltas environments, economies and populations through the 21st Century.

The processes resulting in sinking, shrinking and saltier deltas are interconnected and developing sustainable and inclusive management requires a multidisciplinary system approach. For this, we need to understand the full range of interrelated disciplines, including, amongst others, geology, river and estuarine dynamics, sediment dynamics, hydrology, hydrogeology, geomechanics, bio-morphodynamics as well as the human dimension of delta demography, economy and land use. This session aims to bring together contributions from the full range of scientific disciplines involved in understanding and managing the combined integrated environmental threats that our world’s deltas face. These includes recent advancements in measuring, modeling and projecting environmental dynamics, especially focused on distinguishing (quantifying) anthropogenic and climate change impacts on observed natural dynamics. In particular, inter- and multidisciplinary contributions on the interactions between different environmental processes and efforts towards developing integrated management and development strategies for our sinking, shrinking and saltier deltas are warmly welcomed.