Geography rivers

Source: where a river starts

Upper Course: the steep fast flowing beginning section

Middle course: where the gradient becomes a bit gentler and the wider gets wider

Lower course: the stage near sea level where the river is wide and deeper, where oxbow lakes/ levees/floodplains/ etc form

Mouth: the end of the river where it empties to a larger body of water

Tributary: a smaller stream or river joining a larger one

Confluence: the exact spot where the Tributary joins the main river.

Drainage Basin: the area of land where the surface water has been drained into that specific tiver