Application of multiple two-dimensional interpolation methods to bathymetric data on the FVCOM unstructured triangular grid

In general, the ocean bathymetric dataset is defined on a uniform rectangular grid, whereas FVCOM employs an unstructured triangular grid. Consequently, it is necessary to interpolate the data from the nodes of the rectangular grid onto those of the triangular grid. The nearest neighbor method, bilinear method, and inverse distance weighting (IDW) method are three commonly utilized two-dimensional interpolation techniques, and inverse distance weighted regression (IDWR) represents a more recent interpolation approach. In this study, these methods were applied to interpolate the bathymetric data of the Hormuz Strait and the North Indian Ocean onto the FVCOM triangular grid. The experimental results demonstrate that a very small error in the interpolation of bathymetric data was achieved. Additionally, these methods were compared with the interpolation techniques provided by the MATLAB system. The comparative analysis reveals that the bilinear method can achieve a superior interpolation effect compared to the other three methods.