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Chapter 10: Chapter 10: Streams: Transport to the oceanStreams: Transport to the ocean
1. Hydrological cycle
2. Stream profile and erosion
3. Sediment transport and deposition
4. Meanders
5. Deltas
1) The hydrological cycleStreamsStreams
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
The hydrological cycleThe hydrological cycle
oceansoceans damsdams
rivers
rivers
soilsoil
lakeslakes
plantsplants
snowsnow
mountainsmountains
rainrain
evaporationevaporation
10 elements that are10 elements that areinterrelated in the hydrological cycleinterrelated in the hydrological cycle
2) Stream profile and erosion2) Stream profile and erosionStreamsStreams
longitudinal profile:Steep gradient at head and almost flat at mouth.
Base level:The downward limit to which a stream can cut/erode host rock (“bottom of the hill”).
See Figs 14.13,14,15
2) Stream profile and erosion2) Stream profile and erosionStreamsStreams
Over time streams can erode rock just like sandpaper
3) Sediment transport & deposition3) Sediment transport & depositionStreamsStreams
Stream transport mechanisms:Stream transport mechanisms: in solution (dissolved in water) in suspension bed load (along bottom)
See Fig. 14.2
3) Sediment transport & deposition3) Sediment transport & depositionStreamsStreams
Stream transport mechanisms:Stream transport mechanisms:
in solution (dissolved in water) in suspension bed load (along bottom)
3) Sediment transport & deposition3) Sediment transport & depositionStreamsStreams
Sediment deposition:Sediment deposition: channel deposits floodplain deposits alluvial fans & deltas Alluvial Fan (Death Valley, CA)
Fig. 14.17
4) Meanders4) Meanders
Floodplain:
Stream channel deposits left by meandering rivers.
Fig. 14.9
Oxbow lake
4) Meanders4) Meanders
5) Deltas5) DeltasStreamsStreams
Delta:Delta: depositional platform that forms at the mouth of a river
Distributaries:Distributaries: smaller streams that branch off downstream
Fig. 14.23
Salt marshes:Salt marshes: shallow bays between distributary channels
Multiple choiceMultiple choiceStreamsStreams
Which of the following terms describes a curved, coarse-grained deposit that forms on the inside curve of a stream?
A. duneB. meanderC. oxbowD. point bar
Multiple choiceMultiple choiceStreamsStreams
Curves and bends in a stream channel are called ______.
A. alluvial fansB. braidsC. deltasD. meanders
Multiple choiceMultiple choiceStreamsStreams
At a bend in a river, ______ occurs on the outside of the bend and ______ occurs on the inside of the bend.
A. deposition. . . depositionB. deposition . . . erosionC. erosion . . . deposition D. erosion . . . erosion
Multiple choiceMultiple choiceStreamsStreams
Which of the following would be the most fertile area for crops?
A. a stream channelB. a floodplainC. a natural leveeD. an uplands area away from the stream
Multiple choiceMultiple choiceStreamsStreams
Large, cone-shaped deposits of sediment at a mountain front are called ______.
A. alluvial fansB. deltasC. natural leveesD. terraces