Understand space–time accessibility using a visual metaphor: a case study in Hong Kong–Zhuhai–Macao Belt

Space–time accessibility among spatial elements has been widely studied, but fewer interactive visualization products have been delivered. The concept of space–time accessibility is hard to be displayed, and most methods lack capabilities of handling relevant space–time attribute information in a cartographic form. To tackle this issue, our research presents a visual metaphor method to demonstrate space–time accessibility in a terrain-like form. We first employ a water flow model to analyze the space–time accessibility and further build a terrain-like visual metaphor for effectively displaying the analytical results in a three-dimensional frame. Compared to previous studies, the visual metaphor is used to map the high dimensional space to a lower dimension virtual terrain space with the spatial cognition to comprehensively understand the space–time accessibility of the Hong Kong–Zhuhai–Macao Belt.