メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((143.6375000 44.1708334, 143.6437500 44.1708334, 143.6437500 44.1750000, 143.6375000 44.1750000, 143.6375000 44.1708334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral