Research Plan (2013-2018)
Presentations and Publications from CEGIS
Archive (Past and completed projects)
Current CEGIS Projects
Geospatial Semantics and Ontology
High-performance Computing (HPC)
Spatiotemporal Data Modeling
Volunteered Geographic Information (VGI)
The National Map
The goal of the project "Building Ontology for The National Map" is to specify geospatial feature semantics for richer data models. New data models and associated knowledge organization systems for The National Map can translate traditional topographic information into a flexible spatiotemporal knowledge base that can serve many different application areas.
A USGS Open-File Report, titled "Introduction to Geospatial Semantics and Technology Workshop Handbook", is an introductory tutorial on geospatial semantics with hands-on exercises using standard Web browsers. The workshop is divided into two major sections: general semantics on the Web, and specific examples of geospatial semantics using data from The National Map of the USGS. Additional resources are included.
Constructing Ontologies from The National Map Triples
Guide for Creating and Using National Map RDF Data
Data downloaded from The National Map can be converted into RDF triples by following the steps outlined here.
USGS Created Ontologies
- An ontology outlining the National Hydrography Dataset is available here: NHD Ontology
- An ontology of topographic feature data is available here: US Topographic
The Topographic Feature Vocabularies
A controlled vocabulary provides a way to specify triple data semantics. Formal specifications provide a cohesive basis for a topographic feature type vocabulary for triple data. The feature list is based on standards for the various themes of The National Map, the Digital Line Graph (DLG) feature list derived from field-surveyed 20th-century maps, the Geographic Names Information System (GNIS), and the Spatial Data Transfer Standard (SDTS).
(Note: The files linked below are formatted in Notation 3, but can be manipulated with any text editor)
Built Up Areas
The vocabulary is not meant to be a comprehensive inventory of all available scientific terms. The terms were selected for the original standards based on whether the USGS would produce digital data for those feature types or whether they are recognized in other data sets. The feature list vocabularies will continue to be reviewed and updated.
Links to USGS Feature Lists
Spatial Data Transfer Standard (SDTS) Part 2, Spatial Features
Geographic Names Information System (GNIS)
USGS Digial Line Graph (DLG) and quadrangle map standards
USGS Enhanced Digital Line Graph (DLG-E) (feature list begins on page 30)
SPARQL Endpoint and Sample Data
Selected data sets from The National Map are now available in the data model of the Semantic Web, Resource Description Framework (RDF) triples. These triples can be downloaded and used as linked data for Web 2.0 and Web 3.0 applications. A SPARQL endpoint is available for querying and saving subsets of the data.
Papers and Posters
A collection of publications, posters, and reports are available for specific information about geospatial semantics and ontology.
Abstracts, Presentations and Activities
Our involvement in related events, presentations, and abstracts are included here.
Dalia Varanka, Project Lead
E. Lynn Usery