A novel grid generation method based on multi-resolution data fusion for 2D shallow water models

Aiming at resolving the grid problems caused by the inconsistent resolution requirements when simulating overland flows using the 2D shallow water equations, a novel grid generation method based on multi-resolution data fusion is developed in this work. This method is able to not only reduce the computational burden associated with uniform structured grids but also ensure the simulation accuracy of the hydrodynamic model by reproducing the so-called small-scale effect. The efficiency of the method is assessed using different cases. Theoretical and laboratory cases demonstrate that fused non-uniform structured grids can reproduce hydrographs without appreciable accuracy losses. In addition, a high simulation accuracy (NRMSE ≤ 10.40 %, R² ≥ 0.87) is achieved in the simulation of a real flood event. The performance of this method is very promising in terms of the large-scale flood simulation accuracy, and it significantly reduces the data requirements and computational burden with globally fine uniform grids.