A spatial data model for urban spatial-temporal accessibility analysis

J Geogr Syst. 2020;22(4):447-468. doi: 10.1007/s10109-020-00330-6. Epub 2020 Jun 29.

Abstract

Time geography represents the uncertainty of the space-time position of moving objects through two basic structures, the space-time path and space-time prism, which are subject to the speed allowed in the travel environment. Thus, any attempt at a quantitative time-geographic analysis must consider the actual velocity with respect to space. In a trip, individuals tend to pass through structurally varying spaces, such as linear traffic networks and planar walking surfaces, which are not suitable for use in a single GIS spatial data model (i.e., network, raster) that is only applicable to a single spatial structure (i.e., point, line, polygon). In this study, a velocity model is developed for a traffic network and walking surface-constrained travel environment through the divide-and-conquer principle. The construction of this model can be divided into three basic steps: the spatial layering of the dual-constrained travel environment; independent modelling of each layer using different spatial data models; and generation of layer-based time-geographic framework by merging models of each layer. We demonstrate the usefulness of the model for studying the space-time accessibility of a moving object over a study area with varying spatial structures. Finally, an example is given to analyse the effectiveness of the proposed model.

Keywords: Accessibility; Layer; Spatial data model; Time geography; Velocity.