U.S. Department of the InteriorU.S. Geological Survey

Geospatial Semantic Vocabulary for The National Map

Dalia Varanka, Lynn Usery, and David Mattli

GeoVoCamp

Washington D.C.

June 3-4, 2011

Some Challenges

Great many types of topographic features Sets of spatial relation terms and logical

axioms for topographic features do not exist The vocabulary must serve a wide range of

expert and non-expert users

Parameters for Topographic Terms

Topography means the observation and experience of the landscape environment within a proximity

Topographic data represents natural and built features on the surface of the earth Easily learned basic feature Features that don’t require a lot of abstract

thinking

Scientific applications

Example Query

General Query: Find all other features that cross a given feature

Specific Example: Find all tributaries of West Hunter Creek from the The National Map

Data Conversion

Automated conversion of sample data from The National Map reuses feature codes from digital GIS data models

Topography Semantics

5 .owl/.n3 files by themes

Each term includes:

•Definition•On-line source•Plain English label•URI•(start of) Axiom list

Open Geospatial Consortium Draft GeoSPARQL Specification

OGC Simple Features standard spatial relations based on M. Egenhofer 9-intersection model

Simple Features RCC8 Egenhofer

equals EQ equal

disjoint DC disjoint

intersects ¬ DC ¬ disjoint

touches EC meet

within NTPP + TPP inside + coveredBy

contains NTPPi + TPPi contains + covers

overlaps overlap

Topological Relations

Regional Connection Calculus: relations based on interior, boundary, and exterior contact between two features

*disconnected (DC) *externally connected (EC) *equal (EQ) *partially overlapping (PO) *tangential proper part (TPP) *tangential proper part inverse (TPPi) *non-tangential proper part (NTPP) *non-tangential proper part inverse (NTPPi)

Topographic Spatial Relations

Relations from USGS/partner standards

FLOW Water flowTHROUGH Arroyo (Watercourse or

channel) water flowTHROUGH Channel (Linear deep part of a

body of water) Underground water flowTO The surface of the Earth CAUSED Crater (Circular-shaped depression at the summit of a volcanic cone or one on the surface of the land)

causedBY the impact of a meteorite

Crater (a manmade depression) causedBY an explosion FORM Crossing (A place where two or more routes of transportation)

form a junction or intersection (overpass, underpass)

REMOVED Mine (place where commercial minerals)

removedFROM Earth

Oilfield (area where petroleum is/was)

removedFROM Earth

Spatial Analysis of Relations

For any given feature, Cartographic ‘thumbprint’ of 3 real-world

examples List relations and observations Compare with verb/preposition pairs

Compile for spatial relation vocabulary

Hypothesis

Topological relations (GeoSPARQL)

Mereological (part-whole) relations .owl, skos extensions, and others

Study of spatial cognition embedded in prepositions and their match to spatial relation operators