INTEROPERABILITY BETWEEN THE STRABO SYSTEM AND ARC/GIS AND QGIS

The Strabo Data System is under development to serve the structural geology and tectonics communities. The system is built on a graph rather than relational database structure, and allows for rich and complex data entry as well as incorporation of images (photos, sketches, or other) for documentation or using for a base layer for mapping. Entries in the data system can have complex and numerous relationships to any number of other entries.

Because the Strabo Data System is new and intended to work on mobile devices, it is not a GIS and does not have capabilities to do such tasks as topology or feature generation. We have been working on making the system interoperable with standard GIS programs such as ArcGIS and QGIS. Work is complete on a plugin for ArcGIS and progressing on one for QGIS. There were several development issues in the implementation. First, we had to convert from a graph to a relational/flat data structure. Because entries can have multiple values of the same kind (e.g., multiple strikes and dips) we converted these to multiple features that share the same Strabo ID, but have unique GIS IDs. Second, because we transfer data using JSON and ArcGIS has its own version of this protocol, we wrote custom scripts to interpret information. Third, while images are well integrated in Strabo, the coordinates of information on them (pixel coordinates) do not translate well into GIS. For this aspect we developed custom geometry information for images and data on images. Fourth, datasets in Strabo may contain any combination of geometries (point, line, polygon), but a GIS can only accommodate one geometry per feature dataset. We mediate this by dividing datasets into single geometries during the download process. Finally, we are developing upload protocols for creating or replacing entire datasets or individual data entries in Strabo from within a GIS.