メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((131.1875000 31.8208334, 131.1937500 31.8208334, 131.1937500 31.8250000, 131.1875000 31.8250000, 131.1875000 31.8208334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral