Temporal Topology Density Map

Spatiotemporal data visualization is of paramount importance in several applications, especially for analyzing urban mobility data encoded on topologies. This paper introduces a novel solution, called Temporal Topology Density Map (TTDM), to represent 2D discrete spatial data with temporal variations into a 2D continuous spatial space constrained by a topology. The proposed approach combines topological density maps with Change Frequency Heatmap (CFH) to convey visual information regarding temporal changes, leading to a new visualization method. Two case studies related to the analysis of response time associated with emergency services and walkability changes over time in specific areas of interest demonstrated the effectiveness of TTDM in challenging scenarios. The proposed solution provides an intuitive visualization for supporting the accurate analysis of spatiotemporal data changes over time using topology density maps.