Enhancing Flood Analysis with a Lagrangian Transport Modeling and SERGHEI

Flooding is a devastating natural disaster, and numerical simulations play a crucial role in understanding and preventing such hazards, enabling risk assessment under various scenarios. Natural geophysical flows, such as those caused by river and rain floods, often involve complex multi-physics models. To enhance flood risk estimation, processes like sediment and debris transport (including wood, vehicles, or rocks) should be considered, as they can obstruct infrastructure and exacerbate flooding. This work introduces a study on debris transport during flash floods using a Lagrangian model, where materials are moved by hydrodynamic forces. This model is combined with the Shallow Water Equations in the SERGHEI framework, aiming to create an open-source, high-performance computing (HPC) modeling tool for free surface hydrodynamics. By integrating the Lagrangian Particle Tracking module into SERGHEI, researchers and practitioners gain a powerful tool to analyze the spatial and temporal evolution of debris transport during flash floods, thus facilitating flood management and mitigation efforts. In this work, a specific flooding event that took place in Central Europe in July 2021 is computed. This event tragically led to the loss of more than 180 lives in Germany alone and inflicted significant economic damage on the order of billions of euros. By leveraging the Lagrangian model within this context, a comprehensive investigation of the event can be conducted, contributing to a deeper understanding of its dynamics and consequences.