メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((131.4500000 31.8041667, 131.4562500 31.8041667, 131.4562500 31.8083333, 131.4500000 31.8083333, 131.4500000 31.8041667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral