Last name meaning Ferris: This is an Anglicization of the Old Gaelic name O' Fearghusa - a compound of the Gaelic O (meaning grandson or male descendant) and the personal name Fergus, composed of the elements fear - a man and gus - vigour or force...
At other times, a confluence can be the location where two smaller streams or rivers merge to become the source for a new river. This is the case in Pittsburgh, Pennsylvania, where the Monongahela River and Allegheny River merge to create the Ohio River.
RE: Definition of perched water. Here's a simple explanation. Sometimes there's a clay layer or some rock or some sort of barrier between the surface and way down where the groundwater is. So when it rains, the water leaks down and pools on top of that barrier, instead of making it down to the groundwater, making a falsely high layer of groundwater.