Science streams and rivers
What does a rivers speed a affect?
it affects its ability to wear away or erode the land.
Does the river deposit heavier sediment particles first, then lighter ones?
yes
What are three factors that affect runoff?
1. the nature of the ground surface 2.the amount rainfall 3.whether the land is flat or hilly.
what is the largest divide in North America?
Continental divide
At 18 kilometers an hour what can a river move?
a boulder the size of an arm chair,
levees
a long ridge formed by deposits of sediment along side a river.
How do rivers begin?
a river begins when trickles of water run over the ground and join together in larger streams.
How big is a water shed of a stream that flows down a hill into a river?
a square kilometer or two.
What are tributaries?
are the smaller streams and rivers that feed into a main river.
How does whether the land is flat or hilly affect runoff?
because if there is a steep slope water flows faster down. If it flows faster down some of its runs off instead of soaking into the ground.
Why do tributaries flow toward the main river following a path down hill?
because of the pull of gravity
Why is the soil in a delta very fertile for farming?
because the sediment deposits are rich in nutrients and minerals
Why does the nature of the ground surface affect runoff?
because water soaks into some types of ground coverings more easily than others.
What are water sheds also called?
drainage basins
How does rainfall affect runoff?
during a heavy down pour a lot of rain falls in a short amount of time that is cant all be absorbed in the ground, this causes some of it to become runoff.
The faster the water flow the more ___ it has.
energy
What is a divide?
is a ridge of land that separates when water shed from another.
mouth
is the point where a river flows into another body of water.
erosion
is the process by which fragments of soil and rocks are broken off from the ground surface and carried away.
Deposition
is the process by which soil and rock are left behind.
What is a third factor that affects how fast a river flows?
is the shape of a channel through which a river flows. As water in a river rubs against the side of its channel, it creates friction. this friction slows down the waters movement.
What is one factor that affects how fast a river flows?
is the steepness of a slope
What is a second factor that affects how fast a river flows?
is the volume of water in a river. An increase in the amount of water in a river causes the river to flow faster.
How many square kilometers does the water shed of the mississippi river cover?
more than 3 million
What are the mississippi's largest tributaries?
ohio river and missouri river
What factors are most likely to be seen in the headwaters?
rapids and waterfalls
What causes there to be a bend in a river
small obstacles in the river's channel cause the water to flow slightly from one side to another.
What happens when rivers join another river system?
the areas they drain become part of the largest river's water shed.
flood plain
the broad flat valley through which a river flows
oxbow lake
the crescent- shaped cutoff body of water that remains.
delta
the deposits of sediment at a rivers mouth.
what is a water-shed?
the land area that supplies water to a river system.
headwaters
the many small streams that come together at the source of a river.
sediments
the particles of rock or soil that are moved by water or wind resulting in erosion or deposition
what happens to the fragments that are broken off by erosion?
they are carried along by the moving water until they are deposited in a new location
where does water flow between the rocky and appalachian mountains?
toward the mississippi river or directly in the Gulf of Mexico.
West of the continental divide where does the water flow?
toward the pacific ocean or into the dry great basin, where the water usually evaporates.
True or false Rivers wear away land forms through erosion and build new landforms through deposition.
true
True or false the streams on each side of the divide flow in different directions.
true
runoff
water that flows over the ground surface rather than soaking into the ground.
How does a channel become deeper?
when erosion wears away the sides and cuts deeper into the bottom of the channel.
How do oxbow lakes form?
when the river breaks through the ends of the meander, carving a new channel
How do meanders form?
when the river deposits sediments along the inner edge, where it flows slower.
Why does a flood occur?
when the volume of water in a river increases so much that river over flows its channel.
Does water move faster in a broad deep channel than it does in a shallow narrow channel?
yes because most of the water can flow without any friction.
