Streams and rivers {river, water} receive water directly from rain and indirectly from water runoff from land. Streams are usually wider than they are deep, and erosion sediments can fill them within years. Stream first erodes into valley. Then tributaries enter valley and join first stream. Then valley sides wear down to make wide valley or wear back to make deep valley.
Undertows pull sediment from rivers out to sea. River mouths have sediment triangles {delta}|. Mississippi River makes 600,000,000 tons each year. In sea, corals use minerals, or minerals precipitate out, as at Hudson-River mouth and in Baltic Sea.
circular river current {eddy}|.
shallow river area {ford}|, where people or horses can cross.
Stream can enter salt water, or stream can have sudden flow {freshet}|.
river beginning {headwaters}|.
Rivers curve many times {meander}| if banks are soft, because river cuts away outer bank, deposits soil on inner bank, and widens all curves. Rivers run straight and cut through rock if banks are hard, to make canyons.
rivulet {rill}|.
stream {rivulet}|.
Rivers {tributary}| can flow into larger river.
In stream, hard rock plate {falls}| can persist after lower rock has eroded.
waterfall series {cascade}|.
big waterfall {cataract, water}|.
Stream or river shallow parts can have rocks resistant to erosion, where water flows faster {rapids}|.
rapids {white water}|.
5-Earth Science-Water-Fresh-Areas
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Date Modified: 2022.0225