When building applications that deal with multiple sources of data there is often a need to find relationships between the data sources. Often this occurs when geographical data sources are merged.

Example use cases would be:

• Which areas are contained within / touch / overlap with another given area?

• Is this point within any other spatial area?

• What is within this area of interest that I have defined?

• Can I generalise a larger area from these smaller?

• Enhancement of sameAs type service to manage other kinds of relationship

  containment / touches / overlaps / etc

• Proximity / near to (on what scale?)

• Some relationships may be asymmetric (small place near large place, but not other way)

• Bounding box is a particular issue in SPARQL stores, which often don’t index literals efficiently and make things very slow

• Consider additional bounding box service?

• Could be extension to Linked Data API or in similar style if using that