メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((131.0250000 31.5708334, 131.0312500 31.5708334, 131.0312500 31.5750000, 131.0250000 31.5750000, 131.0250000 31.5708334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral