Assertion: river's confluence | /r/AtLocation | several configurations
Facets:
value: at the point
type: TEMPORAL
value: rejoin at the downstream end
type: LOCATION
Source sentences:
text: A confluence can occur in several configurations: at the point where a tributary joins a larger river (main stem); or where two streams meet to become the source of a river of a new name (such as the confluence of the Monongahela and Allegheny rivers at Pittsburgh, forming the Ohio); or where two separated channels of a river (forming a river island) rejoin at the downstream end.