Streams: Transport to the ocean

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Chapter 10 Streams Transport to the ocean

1. Hydrological cycle
2. Stream profile and erosion
3. Sediment transport and deposition
4. Meanders
5. Deltas

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1) The hydrological cycle
Streams
hydrological cycle
Continuous cycling of water between the
atmosphere, oceans and land, due to gravity and
energy from the Sun
Some factors

• amount of rainfall
• rate of evaporation
• runoff

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soil
oceans
dams
rivers
evaporation
mountains
plants
lakes
snow
rain
The hydrological cycle
10 elements that are interrelated in the
hydrological cycle
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2) Stream profile and erosion
Streams
longitudinal profile
Steep gradient at head and almost flat at mouth.
See Figs 14.13,14,15
Base level
The downward limit to which a stream can
cut/erode host rock (bottom of the hill).
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2) Stream profile and erosion
Streams
Over time streams can erode rock just like
sandpaper
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3) Sediment transport deposition
Streams
Stream transport mechanisms

• in solution (dissolved in water)
• in suspension
• bed load (along bottom)

See Fig. 14.2
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3) Sediment transport deposition
Streams
Stream transport mechanisms

• in solution (dissolved in water)
• in suspension
• bed load (along bottom)

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3) Sediment transport deposition
Streams
Sediment deposition

• channel deposits
• floodplain deposits
• alluvial fans deltas

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4) Meanders
Floodplain Stream channel deposits left by
meandering rivers.
Fig. 14.17
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4) Meanders
Oxbow lake
Fig. 14.9
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5) Deltas
Streams
Delta

• depositional platform that forms at the mouth of
  a river

Distributaries

• smaller streams that branch off downstream

Salt marshes

• shallow bays between distributary channels

Fig. 14.23
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Streams
Multiple choice
  Which of the following terms describes a
curved, coarse-grained deposit that forms on the
inside curve of a stream? A. dune B.
meander C. oxbow D. point bar
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Streams
Multiple choice
Curves and bends in a stream channel are called
______. A. alluvial fans B. braids C.
deltas D. meanders
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Streams
Multiple choice
  At a bend in a river, ______ occurs on the
outside of the bend and ______ occurs on the
inside of the bend. A. deposition. . .
deposition B. deposition . . . erosion C.
erosion . . . deposition D. erosion . . .
erosion
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Streams
Multiple choice
    Which of the following would be the most
fertile area for crops? A. a stream channel B.
a floodplain C. a natural levee D. an uplands
area away from the stream
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Streams
Multiple choice
  Large, cone-shaped deposits of sediment at a
mountain front are called ______. A. alluvial
fans B. deltas C. natural levees D. terraces