Deadline for Abstract Submission: January 15th, 2026

Conveners:

Stefan Haun, Graz University of Technology, Austria

Daniela Molinari, Politecnico di Milano, Italy

Luigia Brandimarte, KTH Royal Institute of Technology, Stockholm, Sweden

Flood risk is rising globally due to a complex interplay of factors, including among others climate change, population dynamics, land use changes, and aging infrastructure. These dynamics are placing increasing pressure on river basins and coastal zones where more people and assets are concentrated in flood-prone areas. Managing flood risk is a critical challenge for public authorities, especially in regions where scientific, technical, and institutional capacities are limited. Effective and sustainable mitigation strategies require an interdisciplinary approach that brings together academic researchers, engineering practitioners, decision-makers, and community stakeholders. Such collaborations must integrate knowledge of natural processes with the socio-technical systems needed to implement effective countermeasures in an integrated risk management framework.

However, in practice, this integration remains challenging. The transfer of scientific knowledge into operational practice is often hindered by fragmented information flows, economic constraints, institutional silos, limited public awareness, and short-term political priorities. Furthermore, while technological advances in flood modelling, high-resolution sensing, and new digital communication tools have proven to be promising in supporting real-time monitoring and improved early warning systems, they are still underutilized. Recognizing the reasons for this lack of implementation can help close improve both emergency responses and long-term resilience planning.

This session aims to strengthen the link between scientific research, practical application, and flood management. We invite contributions that:

1. Present successful and unsuccessful case studies on the implementation of flood risk management tools (e.g., hydrodynamic models, risk assessment software);
2. Discuss barriers to technology adoption in flood defence and management;
3. Provide examples of rapid, remote, and sensor-based data collection during flood events;
4. Highlight multidisciplinary and participatory approaches in flood risk assessment and management.

Deadline for Abstract Submission: January 1st, 2026

Conveners:

Gordon Gilja, University of Zagreb, Croatia

Dong Sop Rhee, Korea Institute of Civil Engineering and Building Technology, South Korea

Earth Observation (EO) provides massive amounts of data about land and water surfaces, leading to a paradigm shift in observing and measuring ecosystem dynamics across multiple spatiotemporal scales. As the availability of EO data increases, cutting-edge monitoring tools are developed, often based on the integration of EO with other remote sensing technologies, providing new informative products to support research, modelling, land planning and decision-making.

This special session, promoted by the newly formed IAHR Remote Sensing Working Group, will focus on recent advances in EO for the monitoring of land and water ecosystems, offering a short overview of the state-of-the-art, addressing current challenges, and discussing future developments. We invite abstracts that deal with this topic from different perspectives, including but not limited to: EO integration with in-situ measurements, generation of new monitoring service, use of new sensors, knowledge disclosed by EO-based monitoring, use of EO data for numerical modelling, and impacts on policy and management.

Deadline for Abstract Submission: January 16th, 2026

Convener: Md Salauddin, University College Dublin, Ireland

This special session on “Building Coastal Resilience with Nature-based and Eco-Engineered Coastal Protections” aims to provide a platform for the diverse community of researchers, practitioners, and stakeholders in the coastal engineering field to explore the applications and potential of Nature-based and Eco-Engineered solutions in coastal management. As sea levels rise and storm surges increase due to climate change, the pressures on coastal defences and surrounding properties are intensifying. While conventional sea defences offer essential protection, their long-term sustainability is questioned due to their ecological impacts and inability to adapt to extreme weather events. The need for research that provides evidence to promote the broader adoption of ecological interventions in both existing and new coastal defences is increasingly recognized.

This session aims to connect academic researchers and industry experts to explore potential pathways for sustainable coastal protection through interdisciplinary collaboration. Such a collision of expertise may promote the maturity of adopting experimental analysis, numerical simulation, AI technologies, and case studies in identifying and quantifying key parameters, and further foster the development of a comprehensive evaluation framework for nature-based solutions and eco-engineering interventions. The outcomes and collaborations of this workshop will advance our coastal protection management towards sustainable and climate-resilient practices.

Topics of Interest: This special session will consider papers on the following topics of interest (but not limited to):

• Quantifying the wave attenuation capacity of natural habitats, including seagrass, mangrove, salt marshes, oyster reefs, and coral reefs;
• Exploring the wave attenuation performance of hybrid solutions that combine natural habitats and built structures;
• Applying numerical models and AI technologies in quantifying the wave attenuation of nature-based solutions;
• Temporal and spatial heterogeneity of natural habitats and its influence on wave attenuation;
• Evaluating the coastal resilience of nature-based solutions under extreme weather events;
• Evaluating the cost-effectiveness of nature-based solutions;
• Climate change impacts on natural habitats and their wave attenuation capacity;
• Improving the existing coastal defenses with eco-engineering interventions to enhance biodiversity;
• Case studies and best practices in implementing nature-based solutions.

Convener: W. Ludwig Kuhn, Norwegian University of Science and Technology, Norway

The main objective of this session to present results enabling an environmentally sustainable hydropower production under a changing climate, optimize the use of water resources to adopt to a changing electricity market, find the optimal trade-offs between the operational regime of regulated watershed to produce hydropower, secure landscapes and biodiversity, and protect the society from flood and draught. Hence, the session will focus on the assessment of water resources, the mitigation of environmental impacts, and the adaptation to future climate change impacts.

Deadline for Abstract Submission: January 31, 2026

Conveners:

Slaven Conevski, Norwegian University of Science and Technology & Multiconsult, Norway

Massimo Guerrero, University of Bologna, Italy

Kamal El Kadi Abderrezzak, Centre for Hydraulic Flows and Structures Monitoring and Engineering (CESAME), France

This Special Session brings together advances in reservoir sedimentation management, numerical modelling, and cutting-edge surrogate techniques for measuring sediment transport processes. We aim to share knowledge, tools, and practical experiences that support the design and implementation of effective, technically sound, and economically viable strategies to counter reservoir sedimentation and related morphological and environmental impacts. A particular focus is placed on integrated monitoring–modelling frameworks, where surrogate measurements (e.g. acoustic backscatter, multibeam bathymetry, image-based velocimetry, remote sensing) support hydro-morphodynamic numerical models of reservoir infilling, delta evolution, and sediment routing.

We welcome contributions from scientists, consultants, dam operators, technology developers, and decision makers on topics including:

• Methods and technologies for monitoring and predicting reservoir sedimentation and associated morphological changes, from catchment to reservoir scale, including process-based and data-driven models constrained by bathymetric surveys and sediment influx monitoring;
• Application and critical assessment of surrogate monitoring techniques – acoustic (e.g. ADCPs, multibeam systems), optical, imaging (e.g. PTV/PIV), and remote-sensing methods – for suspended- and bedload transport;
• Evaluation, calibration, and validation of numerical models, including uncertainty analysis or data-driven approaches;
• Case studies documenting successful and unsuccessful sediment management strategies, with focus on catchments or case studies with reservoirs.

By connecting measurement innovation, numerical modelling, and practical reservoir management, this Special Session seeks to foster cross-disciplinary dialogue and highlight pathways toward resilient and sustainable sediment management worldwide.

Convener: Janek Laanearu, Talinn University of Technology, Estonia

The session is open to contributions on all types of air–water stratified flows that are present in pipes and river channels. Some example areas include (but not exclusive to): water collection system in the urban environment, low-head dams in the river basin, etc. The gravity-flow pipe is a covered channel in which water and air can only move in the direction of conduit walls. This is unlike a river, in which water flows in an open channel and there are no restrictions for air movements. Developments of hydraulic formulae for air-water stratified flow processes are very needed for numerical schemes used in engineering software. Achieving reliability of a hydraulic flow systems, both differential and integral solutions are necessary. Therefore, experimental, more empirical approaches, and numerical modelling studies are welcome to gain better understanding of the air-water stratified flow solutions in any engineering applications of pipelines and riverbeds. Research focusing on air-water interactions in the built environment, which are related to water quality and air pollution are strongly related topics. These contributions can be either on fundamental or applied research topics in these or related areas and can present findings from field studies. Some example areas include (but not limited to): pipeline operations for maintenance and cleaning, point source emissions in the densely populated areas, breaking waves impact etc.

Deadline for Abstract Submissions: January 20, 2026

Convener: Annelie Hedström, Luleå University of Technology, Sweden

The aim of this session is to highlight the challenges and explore future strategies for the built water infrastructure, such as pipe networks and water treatment facilities, in relation to the impacts of climate change and other emerging risks.

Convener: Athanassios Dimas, SEDIMARE Coordinator

The Doctoral Network SEDIMARE is part of the EU Program Marie-Sklodowska-Curie-Actions. In the special session Doctoral Candidates from the Network will present their work (numerical and experimental) on coastal sediment transport and morphodynamics.

Conveners:

Monika Kalinowska, Institute of Geophysics Polish Academy of Sciences, Poland

Kaisa Västilä, Finnish Environment Institute and Aalto University School of Engineering, Finland

Ian Guymer, University of Sheffield, UK

Vegetation strongly affects hydrodynamics, turbulence, and mixing processes in rivers and channels, influencing water quality, sediment transport, and ecosystem functioning. The interactions between flow and vegetation are complex and not fully understood despite their importance. A particular challenge is the up-scaling/transferability of the findings from controlled laboratory conditions to natural environments.

This session brings together researchers working on the influence of aquatic and riparian vegetation on flow and mixing — from small-scale laboratory experiments to vegetated channels and wetlands. Presentations will focus on recent studies addressing physical processes, modelling approaches, tracer-based field investigations, and data-driven analyses, with special emphasis on flow–vegetation interactions, longitudinal dispersion, and vegetation management.

The main goal is to deepen our understanding of these interactions, identify the key scientific questions that still need to be addressed, and discuss how insights from ongoing research projects can support water management strategies.

Convener: Pekka Rossi, University of Oulu, Finland

Rural areas in Arctic and Sub-arctic regions face unique challenges in providing sustainable and resilient sanitation services. Low population density, harsh climatic conditions, limited infrastructure, and emerging environmental concerns require innovative approaches that differ from those applied in urban or temperate settings. This session explores strategies and technologies for wastewater management in sparsely populated and cold regions, focusing on small-scale treatment systems, nature-based solutions, and locally adapted designs. Drawing on experiences from the ArcticSewlutions project funded by the Interreg Northen Periphery and Arctic Programme, which brings together partners from Finland, Sweden, Iceland, and Greenland, the session highlights practical cases, pilot systems, and cross-border collaboration aiming to enhance environmental protection, resource efficiency, and community health. Discussions will emphasize technical feasibility, social acceptability, and long-term sustainability in the context of Arctic development.

Conveners: Mark Langley, WRG Europe

Research on pumped-storage in existing hydropower facilities is the topic of an on-going Horizon-RIA project “Store2Hydro” Jan 2024-Dec 2027. In this session relevant results from this project are presented. Europe and the world are facing an unprecedented change towards sustainably derived sources of electricity, driven by the Paris Agreement and geopolitical energy security concerns, which requires far less reliance on fossil fuels. Storage capacity of electricity is emerging as one major bottleneck due to an increasing amount of variable energy sources like wind and solar as stated in a recent recommendation by the EU. Relatively small adjustments to existing hydropower facilities would allow the electricity storage capacity to increase by 22TWh/y or more in Europe. This can be compared to predictions of total world-wide electricity storage in batteries of 0.55TWh/y by 2025 & thermal storage of 0.88TWh/y by 2030. Hence, while our aim is ambitious, it is achievable since 22TWh/y is only 10% of the EU 28 + Switzerland + Norway, hydropower energy storage capacity.

Convener: Eduard Doujak, TU Wien, Austria

The COST Action CA21104 – PEN@Hydropower has been established in 2022 and builds now a Hydropower community with more than 400 members. The aim of this network is to collaborate and organize knowledge exchange among the different working groups. In this session, the organization will provide several up to date research projects of the different working groups in order to show the magnitude of this network.

The main approach of this network is the holistic approach in assessing hydropower topics. Even sustainability definition is weaker than the definition of a holistic approach in hydropower topics.

We welcome every participant to join this session and to get an overview about the topics, discussions and outputs of COST Action CA21104.