GEOSCIML PORTRAYAL – A PATH TO INTEROPERABLE WEB MAP SERVICES

GeoSciML-Portrayal is an OGC GML simple-feature application schema that has been developed to provide a schema for presentation of geologic map unit, contact, and shear displacement structure (fault and ductile shear zone) descriptions in web map services. The schema establishes naming conventions for fields used in symbolization schemes. Use of standard vocabulary for geologic ages and lithology to populate these fields enables map portrayal using shared legends to achieve visual harmonization of maps provided by different services. The IUGS CGI Interoperability Working Group has developed vocabularies for classification of contacts and faults, and lithology of geologic units (see http://resource.geosciml.org ). Terms for the age of geologic units and faults are defined by the International Commission on Stratigraphy (ICS) Stratigraphic Chart (2009). In addition, the scheme includes text information for human users when browsing a geologic map, a link to a full GeoSciML feature element (if available), and a symbol identifier field to enable a user-defined symbolization scheme in each map service. Most WMS implementations make deployment of a WFS service using the same schema as a WMS service a simple thing, and binding the simple feature WMS and WFS allows clients to acquire basic text geologic feature descriptions that can be used in web-mapping applications to construct custom legends. Binding with full GeoSciML features allows the portrayal scheme to be used in a map browsing and query interface to identify and select features for further processing that can be acquired as highly structured, information-rich, complex GML features.