メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((131.4000000 31.8791667, 131.4062500 31.8791667, 131.4062500 31.8833333, 131.4000000 31.8833333, 131.4000000 31.8791667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral