Hydromorphological processes in aquatic environments such as rivers, estuaries as well as lakes and reservoirs, include entrainment, transport, deposition and sorting processes which 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 transport rates as well as limited supply processes like e.g. scouring or grain sorting, effecting 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. With improved algorithms as well as an increasing computational power, it became feasible to simulate the interaction of water, sediments and air (multiphase flows) with high resolution in space and time. In addition, with an increasing quantity and quality of validation and verification data, both from laboratory experiments and field studies, numerical models become more accurate and it is possible to gain new insight in complex physical processes, e.g. dune development, river bed armoring or density driven transport.

The main goal of this session is to bring together the community of scientists, scholars and engineers, investigating, teaching and applying novel measurement techniques, monitoring concepts and numerical models, 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, quantification and modelling of bed load and suspended load, flocculation, settling, and re-suspension/erosion of such processes relevant to morphological channel changes as bed form development, horizontal channel migration, bed armouring and colmation.

Public information:
Welcome to our EGU online session
HS9.3/GM2.11 Measurements, monitoring and modelling of hydro-morphological processes in open-water environments.

As the format of presenting our research content in a chat is quite new to all of us, we would like to provide some brief information which will be updated on Tuesday evening, according to the response of the authors we got until then.

Our chat session is divided into two sections ( Wed, 06 May, 10:45–12:30 and Wed, 06 May, 14:00–15:45).
There are already many presentations uploaded, some are also open for discussion already. Please feel free to use this option and also check out the presentations prior to the chat session. If possible, prepare your questions in advance so that you can quickly copy / paste them when it is time to do so.

Every author who is interested to participate in the chat will be given a slot where she / he can briefly introduce the work and then answer questions.
The Displays will be presented in the same order as their numbering. Based on the feedback from the authors we set up a rough schedule, which you can find in the document "session material". Please be aware that some spontaneous adaptions might be needed.

Regarding the chat itself:
• All authors have the possibility to introduce their work in 3-4 sentences first. Then we will ask the participants to start with their questions.
• If possible, attendees should prepare their questions in advance so that you can copy / paste them
• For questions: please start your answer by @authorname. If it is related to the display, please indicate the slide's number. That will help to keep track of the discussion.
• When the timeslot is over there is still the possibility to ask / answer questions in the general EGU chat (instead of the session chat).
• The session chat is NOT recorded / stored anywhere.
• Do not forget to use the comment 's function on EGU2020 website .
• Please keep polite and patient, as we might face some technical issues, this procedure is quite new to al

Please find here also an information video from the EGU (https://www.youtube.com/watch?v=xTCPKDmgSVw)

Thanks a lot for your interest and hope to chat with you on Wednesday
the convener team
Kordula, Stefan, Gabi, Axel, Sandor, Stefan, Nils and Bernhard

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.

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.

Soil erosion has been traditionally divided into surface (sheet, rill, and gully erosion) and subsurface erosion (soil piping). Rills and gullies concentrate overland flow, whereas soil pipes concentrate subsurface flow, leading to a significantly increased flow erosivity. These forms of concentrated flow erosion, both above and below ground, represent an important sediment source within watersheds and produce sizeable economic losses (e.g. reduced crop yields, reservoir sedimentation, mass failures including landslides and embankment failures). These processes occur in almost all climatic zones, soil types, and land use conditions suggesting a great variability of controlling factors. Moreover, soil pipes, rills and gullies are effective links for transferring water, sediment and pollutants. Despite their relevance, the physical mechanisms that constitute concentrated flow erosion remain poorly understood.
This session aims to address this research gap and will focus on recent studies aiming to better understand the process of rill, piping and gully erosion, with the ultimate aim of developing predictive tools and effective management strategies. As such we welcome contributions on: monitoring and measurement techniques; the factors and processes controlling rill, piping and gully erosion; modelling approaches; prevention, restoration and control measuress; and the role of soil pipes, rills and gullies in hydrological and sediment connectivity.

Biota affect hydrology, sediment transport, weathering, soil formation over variable temporal and spatial scales and thereby influence, hillslope, fluvial, coastal, and aeolian landscape form and dynamics. In turn, geomorphological processes have large impacts on ecological processes and biogeochemical fluxes by shaping topography and affecting water availability, which determines biological diversity and succession.

Understanding these feedbacks between biological and geomorphological processes is becoming increasingly important as new ‘building with nature’ projects emerge and also increasingly find its way into management (i.e. restoration projects, nature based solutions). Despite some advances, the conceptualisation and quantification of the processes, rates and feedbacks between geomorphology and ecology are still limited, particularly in systems that are sensitive to human-induced or natural environmental change (e.g. high-mountain and polar environments, deserts, hillslopes, rivers and wetlands, salt marshes and deltas). Furthermore, biogeomorphic feedbacks influence important environmental fluxes, and this connection remains poorly understood.

This session firstly seeks contributions that are investigating biogeomorphology on all spatial and temporal scales, including experimental, field and computational/numerical modelling studies. Secondly, the focus lies on studies investigating spatial and temporal variations in biogeomorphic systems controlled by complex feedbacks or heterogeneity in ecosystems which influence physical (e.g. sediment cohesion), biogeochemical (e.g. nutrient and carbon cycling) and ecological processes (e.g. biodiversity). This heterogeneity results in alterations to environmental fluxes (e.g. sediments, water, biogeochemical), the overall functioning of the systems, as well as any potential benefits from ecosystem services. By bringing together scientists from the fields of Geomorphology, Hydrology, Biogeosciences, and Soil Science, in this trans-disciplinary session we aim to stimulate discussion regarding the effects of ecosystem heterogeneity and complexity originating from biogeomorphic systems on environmental processes and feedbacks across varying spatial and temporal scales.