Author(s): Daniel Caviedes-Voullieme; Mario Morales-Hernandez; Maria Gonzalez-Sanchis; Sergio Martinez-Aranda; Shahin Khosh Bin Ghomash
Linked Author(s):
Keywords: Flash floods; High-performance computing; Early warning; Rainfall-runoff
Abstract: Flash floods are a growing hazard, both in the regions where they have traditionally been an issue, as well as in areas where they are an emerging concern due to climate change. Semi-arid and Mediterranean regions are known to experience flash flood phenomena, with varying degrees of severity, but relatively high frequency. One example of this is the recent catastrophic flash flood in the Rambla del Poyo catchment (Valencia, Spain) in October 2024 resulting in massive loss of lives. Despite this being a flash flood prone region, early warning and first response was deficient. In contrast, in more temperate climate zones, flash floods are usually much more limited to specific regions, and have been far less frequent. The Ahr catchment in the Eifel region in western Germany is an example of this. In 2021 a catastrophic flash flood affected the Eifel, resulting in 134 deaths in the Ahr catchment alone. Here too, early warning and response was deficient. Part of the reason for this is that operational flash flood simulation technology for early warning systems (EWS) still does not rely on high resolution, physically-based 2D models. In turn, arguably the main barrier for uptake of 2D shallow water solvers by EWS is the computational effort required, and until recently, the unavailability of scalable shallow water solvers for catchment scale flash floods (Khosh bin Ghomash et al., 2024). The goal of this study is to explore the use of the SERGHEI model (Caviedes-Voullieme et al., 2023) as a proof-of-concept for simulations informing EWS. The concept is straightforward: generate high resolution models of catchments prone to flash floods, with minimal modeller intervention, and explore both model skill and computational cost and efficiency of rainfall-runoff simulations at high resolution, all within HPC environments.
Year: 2025