SERGHEI (SERGHEI-SWE) v1.0: a performance-portable high-performance parallel-computing shallow-water solver for hydrology and environmental hydraulics

Abstract. The Simulation EnviRonment for Geomorphology, Hydrodynamics, and Ecohydrology in Integrated form (SERGHEI) is a multi-dimensional, multi-domain, multi-physics model framework environmental landscape simulation, designed with an outlook towards Earth system modelling. At the core of SERGHEI's innovation its performance-portable high-performance parallel-computing (HPC) implementation, built from scratch on Kokkos portability layer, allowing SERGHEI to be deployed, fashion, graphics processing unit (GPU)-based heterogeneous systems. In this work, we explore combinations MPI using OpenMP CUDA backends. contribution, introduce present detail first operational module solving shallow-water equations (SERGHEI-SWE) HPC implementation. This applicable hydrological problems including flooding runoff generation, Its applicability demonstrated by testing several well-known benchmarks large-scale problems, which SERGHEI-SWE achieves excellent results different types problems. Finally, scalability performance evaluated TOP500 systems, very good scaling range over 20 000 CPUs up 256 state-of-the art GPUs.