メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.1812500 36.8125000, 138.1875000 36.8125000, 138.1875000 36.8166667, 138.1812500 36.8166667, 138.1812500 36.8125000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral