Block:
Namei
Date:
EARTH SCIENCE 11
9.
Describe three factors that can cause a rive/s speed and discharge to decrease, leading to
deposition?
a.
b.
c.
(BONUS)
d.
10. How does a delta form?
tt. Some rivers do not form deltas although they carry lots of sediment. Why? (2 marks)
a.
b.
Amazon River:
Columbia River:
72. How is an alluvialfan formed?
73. How are alluvial fans different from deltas? (3 marks) Alluvial fans:
a.
b.
c.
L4. How do natural levees form?
15. Why are flood plains so fertile?
15. What causes floods on large rivers?
17. Explain how each of the followin8 can help prevent floods?
a. Reforestation:
b. Building of dams:
c. Artificial levees:
d. Spillways:
18. Label the diagram with levee, back swamp, river, oxbow lake, river bank (5 marks)
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