Author(s): Florian Cordier; Emmanuel Ah-Woane; Mohammed Assaba; Samer Majdalani; Moussa Roger; Olivier Delestre
Linked Author(s): Florian Cordier
Keywords: Flash Flood modelling Hydraulic Structures TELEMAC-2D HPC Scalability
Abstract: The Brague river (South-east France) often encounters flash floods, notably recently in the last decade in 2011,2015 and 2019. The event of 2015 led to consequent damages, resulting in human loss and significant damage accounting for several hundred million euros. This flood event was previously studied both using hydrological and hydraulic approaches. In this work, we restart from a previous existing numerical model built with TELEMAC-2D, which simulates the flood event of 2015 in the downstream area of the Brague river, based on a 2D approach on an unstructured mesh. The present analysis focus on the main course and its tributaries. Several hydraulic structures cross the river, which can hinder the river flow during extreme flood events. The objectives of this work are multiple: i) assess the influence of hydraulic structures representation within the domain on hydraulic discharge, particularly beneath roadways and bridges, to examine the resultant variations in flood extents and water depth both upstream and downstream, ii) study the influence of physical and numerical parameters on simulated flood characteristics and iii) evaluate HPC performance to solve this problem by assessing main computational indicators. Numerical results are analyzed and compared to field observations. The findings could help in guiding management policies and practices, offering a scientific foundation for decision making in the context of flood events under such configurations.
Year: 2025