Authors: AJ Bengoa, Philip Ethington, Jennifer Swift and Robert Vos
This presentation highlights the journey of how a theory about historical development (historical inscription) was tested with a GIS process (Ethington Transections), and then how this process was automated to create a program utilizing Esri’s ArcGIS ModelBuilder. The particulars of the translation at each stage will be discussed, highlighting the major decisions and compromises necessary to complete this iteration of the program. The final result streamlines the process of turning common polygon-distributed data inputs into transections, which are a new technique for visualizing the act of moving through the landscape over time, “Ethington Transections” are defined as a cross-sectional sample of data from polygons to simulate a single, directional line of transit. Historian Phillip Ethington has invented these hybrid charts/maps to visualize social change in space and time. As featured in forthcoming book, Ghost Metropolis: A Global History of Los Angeles since 13,000, transections allow the viewer to take journeys along major Los Angeles boulevards with real-time depiction of historical change. The program is shared via a custom toolbox in Esri’s ArcGIS ModelBuilder with seven custom models. The toolbox was heavily documented and supplemented with contextual help, readme files and video walkthroughs to aid users with both the technical aspects of using the program and the theoretical basis for the analyses. The toolbox models create an editable map and graph layout and an organized geodatabase of intermediate outputs that can be reused for additional analyses or presentations. The entire work was then shared on GitHub to allow for open-sourcing further development of the toolbox and its possible additional translation into an ArcGIS Python Add-In. This work would greatly benefit from DevSummit colleagues’ insights into further developing it as part of Esri’s suite of visual analysis tools.
