Time for Large-Scale Modeling? Results of SRH-2D Parallelization Effort

Two-dimensional (2D) river flow simulation has been routinely carried out in recent years for project applications due to the availability of stable and reliable general-purpose 2D hydraulic models. However, 2D modeling is generally limited to applications with small- to medium-scale problems due mainly to prohibitively long computer run time. In this study, an effort to significantly speed up model runs, conducted at the Bureau of Reclamation (USBR), is reported. Both MPI and GPU parallel computing techniques are explored with the SRH-2D model. The objective is to achieve large-scale 2D hydraulic modeling on standard personal computers (PCs) within a reasonable run time. The parallelization techniques adopted with SRH-2D are described herein, and two test cases from past USBR large-scale river projects are used to demonstrate parallel performance. The results are presented to verify that the parallel implementation has been carried out correctly and successfully and to document the speed up performance with both MPI and GPU technologies. It is found that significant speedup has been achieved, so the time is ripe for performing large-scale 2D hydraulic simulation using the parallel model and standard PCs.