*Article* **Heterogeneous Parallel Implementation of Large-Scale Numerical Simulation of Saint-Venant Equations**

**Yongmeng Qi 1, Qiang Li 1,\*, Zhigang Zhao 1, Jiahua Zhang 1, Lingyun Gao 2, Wu Yuan 2, Zhonghua Lu 2, Ningming Nie 2, Xiaomin Shang <sup>1</sup> and Shunan Tao <sup>1</sup>**


**Abstract:** Large-scale floods are one of the major events that impact the national economy and people's livelihood every year during the flood season. Predicting the factors of flood evolution is a worldwide problem. We use the two-dimensional Saint-Venant equations as an example and for high-performance computing in modelling the flood behavior. Discretization of the two-dimensional Saint-Venant equations with initial and boundary conditions with the finite difference method in the explicit leapfrog scheme is carried out. Afterwards, we employed a large-scale heterogeneous parallel solution on the "SunRising-1" supercomputer system using MPI, OpenMP, Pthread, and OpenCL runtime libraries. On this basis, we applied communication/calculation overlapping and the local memory acceleration to optimize the performance. Finally, various performance tests of the parallel scheme are carried out from different perspectives. We have found this method is efficient and recommend this approach be used in solving systems of partial differential equations similar to the Saint-Venant equations.

**Keywords:** Saint-Venant equations; finite difference method; parallel computing; heterogeneous computing
