Open Geospatial Consortium Environmental Linked Features Interoperability Experiment. report 
Two core functional goals motivated the engineering described in this report:
1) The need to encode relationships between and among environmental features, and
2) the need to link observational data to the features they describe.
Given that relationships in the absence of context are of little value, a third goal was the need for an ultimately general preview of a feature to provide just enough context in a ubiquitous form.
These three functional goals coupled with a non-functional goal of using highly-adoptable technologies provided more than enough problem space for the interoperability experiment to take on.
See The Hydro Network-Linked Data Index. page