A hybrid movement grid system with coarse mesh and fine mesh for simulation of storm surge is proposed. The governing equations are approximated by a second-order accurate finite-difference algorithm on a space staggered grid system. The proposed method can give better prediction of surge levels at Hong Kong, Gangkou and Shanwei than only using coarse mesh.
The prediction of the rise in water level during the passage of typhoons is· a prerequisite for the design of reclamation formation levels. Although three-dimensional finite-difference models have been used extensively in the last twenty years to simulate, the proposed method in this paper shows that the two-dimensional model can be used to get the same good results as 3-D models. A single storm surge model for the northern South China Sea is too coarse to be able to predict the variation in surge levels at Hong Kong waters. In this paper, a hybrid movement grid system with coarse and fine mesh is proposed. The fine mesh moving with the typhoon center is employed to simulate the rapid changes of storm induced current around typhoon center. The computation results on the hybrid movement grid system and field records show excellent agreement.
The movement of typhoon concerns large coastal area, so the" numerical modeling concerns large computational region. In using FDM, if the mesh is coarse, excellent accuracy cannot be obtained; if the mesh is fine, the large times of computation will be taken and may be beyond the capability of computers. A hybrid non-movement grid system (Li and Zhan) was proposed to simulate storm surge. In this paper, a hybrid movement grid system for the simulation of storm surge is proposed. The grid system consists of coarse mesh and fine mesh.
