A groundbreaking study led by Francisco Vallés Morán, a researcher at the Institute of Water and Environmental Engineering (IIAMA) at the Universitat Politècnica de València, has provided new insights into the devastating flooding caused by the DANA on October 29, 2024, in l’Horta Sud, Valencia. Utilizing advanced two-dimensional hydraulic modelling techniques, the research offers a detailed analysis of the event, capturing the dynamics, extent, and impact of the flooding.
The study, published in the Cuadernos de Geografía of the University of Valencia, accurately reproduces the event’s dynamics, revealing the extent of the flooding and the overflowing flows that resulted in significant material and human damage. By leveraging public information and open-access tools, the research reconstructs the hydraulic behaviour of the Poyo–Torrent and Poçalet–Saleta ravine systems, highlighting extreme flow velocities, arrival times at affected towns, and water depths exceeding four metres in certain urban areas.
Revealing the Speed and Violence of the Flood
The findings underscore the extraordinary speed and intensity of the flooding, with velocities reaching up to 8 m/s and response times of less than an hour between the headwaters and the most densely populated areas. According to IIAMA Research,
‘The results show the extraordinary speed and violence of the episode.’
The study confirms the reliability of hydraulic modelling in replicating the real-world conditions observed during the storm, both in terms of flooding extent and water levels, as well as the temporal evolution of the process. A significant finding is the role of transport infrastructures, such as the V-31 motorway, which exacerbated the flooding upstream by generating backwater effects.
Innovation in Emergency Response
One of the study’s most innovative contributions is the development of a tool that uses the hydraulic power of the current as an indicator of its carrying capacity. This approach allows for the identification of the most energetic overtopping flow trajectories, pinpointing areas where this energy dissipates and where people or objects swept away by the flood are likely to accumulate.
Professor Vallés highlights the practical application of this methodology:
“This methodology was applied during the October 2024 episode and proved useful to the emergency services, facilitating the search for missing people.”
The tool, exportable in georeferenced formats, marks a significant advancement in applying hydraulic knowledge to emergency management.
Implications for Future Flood Management
The study’s results provide valuable insights for assessing existing infrastructure and developing adaptation strategies in response to the increasingly frequent and intense events associated with climate change. The work demonstrates the potential of applied hydraulic science to enhance flood risk planning and prevention, as well as operational response during emergencies.
Professor Vallés concludes,
‘The possibility of having reliable simulations in near real time opens up new avenues for improving decision-making, optimising the search for missing persons and, potentially, saving human lives in future extreme events.’
This research represents a critical step forward in understanding and mitigating the impacts of severe weather events, offering hope for more effective management of future crises.
