~ FREE ZOOM WEBINAR ~
2nd Flood Risk Management Webinar - Wading into Floods from Dam and Dike Failures

October 28, 2025, Tuesday
16:00 UTC | 17:00 Madrid | 24:00 Beijing | 09:00 Los Angeles | 12:00 New York

Registration

The second webinar of the IAHR Technical Committee on Flood Risk Management will focuses on the critical topic of dam and levee failures and the resulting floods. Participants will explore the challenges posed by such failures and the urgent need for advanced tools for numerical simulation. The session will highlight innovative modeling approaches that help predict dike failure and resulting flood dynamics, assess risks, and support effective flood risk management.

Speakers

Chairs

Program

Opening address (20 mins)

• Kamal El Kadi Abderrezzak | Compagnie Nationale du Rhône (CNR), Direction Exploitation, CESAME

• Stefan Haun | Chair of Committee on Flood Risk Management IAHR, Head of Institute of Hydraulic Engineering and Water Resources Management, Graz University of Technology

• Daniela Molinari | Politecnico di Milano

• Cesar Alvarado Ancieta | Academic Leader Postgraduate Flood Risk Management, University of Technology and Engineering, Lima-Peru

Presenters

• Introduction to DLBreach – A simplified physically-based model of dam/levee/barrier breaching in inland and coastal waters (30 mins)
  Weiming WU | Civil and Environmental Engineering Department, Clarkson University Potsdam, NY, USA

• Large-scale simulations of dam- and levee-breach induced flooding: challenges and applications (30 mins)
  Renato VACONDIO | Department of Engineering and Architecture, University of Parma, Italy
  Susanna DAZZI | Department of Engineering and Architecture, University of Parma, Italy

• Numerical simulation of internal dam-break in the reservoir with analysis of potential effects: study case of Stare Miasto reservoir in Poland (15 mins)
  Tomasz DYSARZ | Hydraulic and Sanitary Engineering, Poznan University of Life Sciences, Poland

Open Discussion (25 minutes)

Closing Remarks (5 mins)

• Kamal El Kadi Abderrezzak | Compagnie Nationale du Rhône (CNR), Direction Exploitation, CESAME

• Stefan Haun | Chair of Committee on Flood Risk Management IAHR, Head of Institute of Hydraulic Engineering and Water Resources Management, Graz University of Technology

• Daniela Molinari | Politecnico di Milano

• Cesar Alvarado Ancieta | Academic Leader Postgraduate Flood Risk Management, University of Technology and Engineering, Lima-Peru

Abstracts of the Presentations

Introduction to DLBreach – A simplified physically-based model of dam/levee/barrier breaching in inland and coastal waters (by Weiming WU): The DLBreach model simulates the breaching processes of homogenous and composite earthen embankments due to overtopping and piping in inland and coastal contexts. It approximates the overtopping breach cross-section as a trapezoid, and the breach longitudinal section as a flat top connected with a headcut (vertical drop) or a straight slope for cohesive and non-cohesive homogeneous embankments, respectively. The piping breach is approximated as a flat pipe with a rectangular cross-section until the pipe top collapses, and then overtopping takes place. DLBreach divides the overtopping breaching process into two stages. The first stage is the intensive breaching or erosion stage, in which the breach flow is supercritical, controlled by upstream. The second stage is the general breach or inlet evolution stage, in which the flow is subcritical, controlled by downstream or both upstream and downstream. The breach flow is calculated using the weir flow equation in the first stage, and using the Keulegan equation in the second stage. A non-equilibrium total-load transport model and a cohesive sediment erosion model are adopted for non-cohesive and cohesive embankment erosion, respectively. The time-averaged headcut migration rate is determined using the energy-based formula of Temple (1992). The model allows subbase erosion and incomplete breach. It can consider breaching at one side or in the middle of embankment length. It also considers the breaching due to overflow and wave overtopping on coastal dikes and barriers, as well as the influence of longshore sediment on the breach development. DLBreach has been extensively tested by using more than 50 sets of dam breach data and 4 sets of levee/barrier breach data from laboratory experiments and field case studies. The calculated peak breach discharges, breach widths, and breach characteristic times agree generally well with the measured data.

Large-scale simulations of dam- and levee-breach induced flooding: challenges and applications (by Renato Vacondio & Susanna Dazzi): Dam and levee breaches can generate severe floods, especially in urban areas characterized by complex topography and infrastructures. This presentation addresses challenges of large-scale simulations based on two-dimensional shallow water models, focusing on high-resolution finite volume schemes, robust wet/dry interfaces, and computational efficiency. Special attention is given to coupling breach evolution with flood propagation, supporting improved hazard assessment and emergency planning.

Numerical simulation of internal dam-break in the reservoir with analysis of potential effects: study case of Stare Miasto reservoir in Poland (by Tomasz Dysarz): The purpose of the presented research is to analyze the internal dam-break in a specific two-stage reservoir called Stare Miasto (Poland). The reservoir consists of a primary dam and an internal dam that separates the upper zone from the rest of the reservoir. Additionally, the main part is split by the large abutments of a highway bridge that crosses the reservoir. In 2014 a large flood wave propagated through the reservoir with an estimated peak discharge exceeding several times the mean flow in the Powa River. The conditions were so extreme during the flood and the crest of the internal dam was shifted generating a potential risk of failure. The consequences of such a potential dam break were analyzed using the numerical tool Iber. Different scenarios of the dam-break were analyzed considering three historical bathymetries. Wave propagation in the reservoir is focused on the threat to the bridge piers and main dam. The results obtained prove that the dam-break is the primary cause of the shear stress increase in the cases of lower flows. In case of moderate discharges, the dam-break significantly increased the maximum shear stresses. In cases with greater values of peak flow, the impact of the break is smaller. The presented study may be a basis for the assessment of risk related to reservoir management or plans of prevention against dam-break.

About the Speakers

Weiming WU is a Chair Professor at Clarkson University, USA. He has developed a series of 1-D, 2-D and 3-D models for flow and sediment transport in riverine and coastal waters, as well as dam/levee breach models. He authored 2 books “Computational River Dynamics” and “Sediment Transport Dynamics” in 2007 and 2023, respectively. In addition, he has published more than 150 articles on journals and conferences. He received a best paper award in 2007 from World Association for Sedimentation and Erosion Research (WASER). He is a Fellow of ASCE and IAHR. He served as Associate Editor for International Journal of Sediment Research in 2008-2010 and for Journal of Hydraulic Engineering in 2010-2019, as well as Chair for ASCE Computational Hydraulics Committee (2010-2012), Task Committee on Dam/Levee Breaching (2009-2012), and Sedimentation Committee (2016-2018). He currently serves as Vice President for WASER.

Renato VACONDIO is an Associate Professor at the University of Parma, specializing in hydraulic engineering with a focus on flood risk assessment and mitigation. He leads advanced numerical simulations to analyze flood dynamics. Renato serves also as Chair of the SPHERIC organization, which promotes research and collaboration in the field of Smoothed Particle Hydrodynamics (SPH) for environmental and engineering applications. In 2015, he was awarded the prestigious SIR (Scientific Independence of Young Researchers) grant for the project titled “FLOOD risk management based on PARallel numerical simulations”, supporting his research on parallel computing techniques for largescale flood modeling. Throughout his career, Renato has contributed to both fundamental research and applied studies in flood modeling, using advanced numerical techniques to support hazard mitigation and infrastructure resilience planning

Susanna DAZZI is currently an Assistant Professor at the Department of Engineering and Architecture of the University of Parma (Italy), where she got her PhD in 2016. Her main research interest is the development and application of numerical models for flood simulation, focusing both on the implementation of 2D shallow-water codes with enhanced computational efficiency thanks to GPU parallelization, and on field-scale engineering applications of flood simulations (e.g., river flood propagation, urban inundations, levee-breach and dam-break flows, hydraulic hazard assessments). Additional research fields include machinelearning methods for flood forecasting, local time stepping algorithms, numerical modelling of unsteady mixed flows.

Tomasz DYSARZ is a scientist from Poznan University of Life Sciences in Poland. His professional activity is related to flood management, river and reservoir flow, and sediment transport in water systems. These interests were essential in his work for several research institutions in Poland. In periods 2013-2015 and 2017-2020, he was participating in the implementation of the EU Flood Directive as an employee of the Institute of Meteorology and Water Management in Poland. It given him unique experience and insight into the problems of flood risk management. Since 2023 he is an Associate Editor in the International Journal of River Basin Management (Taylor & Francis). He also cooperates as a member of editorial and advisory boards with Journal of Flood Risk Management (Wiley). In his professional work, Mr. Tomasz Dysarz is implementing hydraulic and hydrologic modeling, GIS software, and programming tools.

How to Participate

This webinar will be held via ZOOM Webinar, please click here to register the Zoom Webinar.

About the Technical Committee

The IAHR Technical Committee on Flood Risk Management is dedicated to providing a platform within IAHR to promote and support discussion and research on flood risk management, with focuses on prevention, protection, preparedness, emergency response, recovery and lessons learned, and resilience. Find out more details and join this committee:

» IAHR Technical Committee on Flood Risk Management

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