Author(s): Yexuan Sun; Peng Hu

Linked Author(s):

Keywords: Rainfall-runoff simulation; Drainage network; 1D-2D model coupling; GPU acceleration; LTS method

Abstract: Urban flood prediction and risk assessment require advanced modeling techniques to efficiently simulate surface runoff and drainage processes. This study develops a novel 1D-2D coupled hydrodynamic model featuring bidirectional coupling between surface flow and drainage network modules. The surface module employs a GPU-accelerated shallow water model with local time-stepping (LTS) algorithm. The drainage network module integrates 1D two-component pressure approach (TPA) pipes model with a 2D junction solver enabling dynamic flow exchange at manholes. An important innovation is the implementation of LTS method, which enhances computational efficiency by allowing cell-specific time step updates, demonstrating computational speedup factors of 2.5–5.12x compared to GPU-accelerated models using global minimum time steps. The model demonstrates satisfactory performance in the laboratory benchmarks, with the majority of Nash-Sutcliffe coefficients exceeding 0.85.

DOI: https://doi.org/10.64697/978-90-835589-7-4_41WC-P1969-cd

Year: 2025