What is a tributary river characterized for?

The Columbia River's tributaries originate in mountainous areas characterized by subalpine forest. Here, the gradient is steep and stream velocity is high. As the Columbia's tributaries flow into the interior of the basin, pine and fir trees dominate the forest. read more

Not being a geography expert as my son is, I can only say that to my best knowledge, a tributary of a river is a more minor river that can be single, or have sub-branches, emanating from a catchment area, and eventually feeds into a main or primary river. read more

A river is characterized by continuously flowing water from an upland source into lakes, wetlands or the sea. Rivers are fed by tributary streams or springs, and they include a river channel, shoreline and a floodplain. read more

A tributary or affluent is a stream or river that flows into a larger stream or main stem (or parent) river or a lake. A tributary does not flow directly into a sea or ocean. Tributaries and the main stem river drain the surrounding drainage basin of its surface water and groundwater, leading the water out into an ocean. read more