Show:
How Rivers Form
Deposition
Floods
Vocabulary
Where on Earth?
100
Where do rivers typically begin?
high in the mountains
100
What do rivers usually drop somewhere along their course?
sediment
100
Why do most floodings occur?
Because of seasonal changes in rainfall or snowfall
100
what are tributaries?
rivers or streams feeding into a major river
100
What is the longest river in California?
Sacramento River
200
All rivers ultimately empty into what?
large bodies of water such as lakes and oceans.
200
Deposition of sediment cuts off the loop in a river, forming a what?
oxbow lake
200
What is a flash flood?
a sudden flood after a storm
200
what is deposition?
the process of dropping sediments
200
Which river delta is called a "bird's foot" delta?
Mississippi River
300
What is a powerful force in changing Earth's landscape?
water running downhill
300
Deposition helps create a variety of what?
surface features
300
What are the damaging effects of receding floodwaters?
ruin homes, businesses and crops. Overflowing sewers can cause health hazards
300
what is an alluvial fan?
fan shaped landmass that forms after water rushes down a steep slope, then slows over a flat plain.
300
In 1996 and 1997, what state received 98 inches of snow from 8 blizzards?
North Dakota
400
rain water or melting snow that flows over the ground is known as what?
runoff
400
When the river gets closer to the ocean, what gradually happens to the land?
it levels out (becomes flatter)
400
What are leeves?
mounds built to hold back reservoirs, rivers, or other bodies of water.
400
What is a meander? and why do they occur?
a bend in the river formed when the river moves across wide, flat regions. Meanders occur because the flow of the river slows down on the inside and speeds up on the outside of each curve.
400
In what location on Earth are alluvial fans common?
Death Valley, California
500
What do rivers do in a continuous pattern? (4 things)
erode, move sediment, change course and flood their banks
500
How do meanders increase in size?
Meanders increase in size as water erodes the outside of each curve and deposits sediment on the inside.
500
In the U.S., seasonal flooding usually occurs when? Name at least three factors of flooding.
very snowy winters or sudden warm spell - large amount of melt water enters the river, severe storms, broken dams and leeves, seasonal changes in rainfall or snowfall.
500
What is a delta, what shape do they take, and what river has a vast delta?
a delta is a low plain that forms where a river enters the ocean. Deltas take the shape of a triangle. The Mississippi River has a vast delta.
500
In 2005, Lake Pontchartrain burst through part of its levee, sending floodwaters in to what city? What caused the levee to burst?
New Orleans; Hurricane Katrina