THE MAPBOARD, REIMAGINED DIGITALLY — BUILDING A USER-INTERFACE TAILORED FOR FIELD GEOLOGICAL MAPPING

Abstract

The reliance of field geology on hand-drawn maps seems anachronistic. But, the complexities of physical media aside, manual drawing remains a highly optimized user interface for geologic mapping. Quick capture of detailed shapes, immediate visual assessment, and rapid revision enable high-confidence rendering of complex map patterns; these features support experimentation and rapid learning by trainee geologists. With recent innovations in high-precision stylus input, many modern iPad digital mapping packages (e.g. ESRI Field Maps, StraboSpot, and TouchGIS) have added tools to capture drawn features. However, these packages retain two major shortcomings of traditional geospatial information systems (GIS) for geological mapping: 1. their editing and deletion tools are geared towards precision over simplicity, and 2. they provide no tools to manage topology. A fully defined geologic map is a planar graph with space-filling units bounded by contacts. On a paper field map, unit relationships are represented by applying color pencil between contacts; the corresponding GIS workflow requires unit boundaries to be finalized before polygons can be created. This multistep workflow precludes iterative map production. The Mapboard GIS iPad app (https://davenquinn.com/projects/mapboard-gis) attempts to bring the strengths of analog tools to the digital-mapping realm. The editing interface elevates simple and intuitive drawing and erasing over complex GIS operations. An iterative, real-time topological solver automatically expands contacts into space-filling unit polygons. In addition to untethered field operation, Mapboard GIS can stream features over a network into a robust, open-source database backend (https://github.com/davenquinn/postgis-geologic-map), enabling integration with desktop GIS software and real-time collaborative mapping. Focused backends can also be created to support specific integrations, such as applying editing workflows to the Macrostrat multiscale geologic map compilation. Mapboard GIS has been in development since 2018 and will be publicly released in fall 2020; prototypes have enabled rapid production of detailed geologic maps of several locales. The simple map-creation interface is approachable for relative novices. The app presents a strong design vision for a key digital field tool, tailored to closely align with the legacy of its analog predecessors.