Abstract: Topology analysis method of feature-based visualization can show quickly the overall structure of flow field, and is of a greater superiority in focusing on the special structure of the flow field. However, in many cases, it is not enough to only show the structure of the flow field, we also want to know the topological region in detail. Traditional methods to determine the topological region are based on the imaginary part of feature vector, but these approaches are too general, and, because the area size is only relative, it doesn’t consider the impact of the near critical points to the surrounding fluid. In order to show truly the impact of the critical points to around flow movement, Voronoi diagram is proposed to divide the topological region, and the method has been applied to ocean flow fields. Compared to the traditional feature vectors method and proved through experiments, it can achieve better results.

Key words: feature-based visualization, ocean flow field, topological region, Voronoi diagram