A Mesh Reduced Method for Speeding Up Structured Grid-Based Water Quantity and Quality Models in Large-Scale River Networks

High-precision and efficiently distributed discrete element models for water environment simulation are urgently needed in large-scale river network areas, but most distributed discrete element models are serially computed and need performance improving. Parallel computing and other common methods for models’ high performance have large labor costs and are complicated. We put forward a new mesh reduced method for promoting computational efficiency with grid re-organization according to the structure and algorithm characteristics of 2D and 3D numerical models. This simple and cheap method was adapted to a classical three-dimensional hydrodynamic and sediment model (ECOMSED) for model improvement and effective evaluation. Six schemes with different grids were made to investigate the performance of this method in the river network area of the Three Gorges Reservoir Basin. It showed good characteristics of simulation performance and model speed-up. We concluded that the method is viable and efficient for optimizing distributed discrete element models.