Ch16 Flashcards
Channeled movement of water along a valley bottom.
Stream flow
the unchanneled movement of surface water down a slope
Overland flow
That portion of the total terrain in which a drainage system is clearly established.
Valley
The higher land above the valley sides that separates adjacent valleys
Interfluve
An area that contributes overland flow & groundwater to a specific stream (also called a watershed or catchment) terminates at drainage divide
Drainage basin
The line of separation between runoff that descends into two different drainage basins
Drainage divide
When something is transferred to another location and set down
Deposition
- involve running water
- running water is earths most important external agent
- it is ubiquitous (everywhere except Antarctica) frozen glaciers not water.
Impact of
FLUVIAL PROCESSES
- also involves running water & FLUVIAL processes
- CHANNELED movement of watt along valley bottom. Wether tiny creek or enormous river.
Stream flow
UNCHANNELED downslope movement of water along surface water.
Overland flow
This is a drainage system of channeled (stream) flow. The portion of terrain where the drainage system is clearly established. partially or totally occupied by a channel of stream. ““Bottom and ““walls that rise above “” bottom in both sides.
Valley
No clearly established channeled flow. Higher land area between valleys. Overland flow. Higher land above valley walls that separated adjacent valleys. anything in the terrain not part of the valley is an?
Interfluve
Valley bottoms, valley sides, interfluves that drain toward the valley are the divide sub basins of
The drainage basin
Line of separation between runoff that discards in the direction of one drainage basin,
Drainage divides
the hierarchy of smaller tributary sub basins are part of the “”
Main stream basin.
1st order stream is the smallest stream, has no tributaries.
2nd order behind at the confluence of 1st order streams.
3rd order begins at the confluence of the 2nd order streams.
Stream orders.
Divide of main drainage basin.
Load
Types of load
Competence/capacity.
Transportation
Amount of loads water can carry depends on 2 things
Speed/velocity
And volume.
(And slope)
Load
When volume and speed /velocity decreases, this happens
Transportation deposition
This begins when rain falls over the lithosphere
Erosion
- Particles move downhill on slope
2. Across surface as a thin sheet
Splash erosion
Sheet erosion
- Turbulence breaks up into tiny channels.
2. fewer larger gullies. Goes from land flow to stream flow.
Rills erosion
Gully erosion
Bed load
Saltation
Traction
Dissolved (pushing)& suspended (bouncing/jumping)load.
Types of load
- Minerals mostly salts, dissolved -load
- Fine particles of clay & silt carried in suspension very slow settling speed-suspended load
- sand/gravel & large rocks- bed load.
Types of loads defined
Stream deposited sediment””. When smooth, sorted rounded particles become stratified deposits. That cause a decrease in flow speed. Usually reduced to 1.2.3.4.5.6 what are they in order?
ALLUVIUM.
- boulders.
- cobblers.
- pebbles.
- sand.
- silt.
- clay.
Periods of peak stream flow, -erode upper portions of valleys -form vast flood plains in lower parts of valleys.
Floods
Stream that flows w/water 12months of the year.
Streams that flow during rain, “intermittent stream” seasonal. water only in wet season.
Perennial
Ephemeral
Tightly curved loops.
Abandoned channels.
“Mississippi river”
Where land is flat, like in large flood plains.
Meandering channels
Erosion occurs ““of the curves.
Deposition occurs “” of the curves.
Outside
Inside
Erosion takes place here because water moves faster. Outer curve also called “”
Outer-bank
Inside bank, inside curve, also called “” where deposition takes place and water moves slow
Point bar
When a river cuts across a “” of a meander, the river bend becomes an “” lake. And then an”” swamp and then a “ scar.
Neck
Oxbow
Oxbow
Meander
A measure of the particle size a steam can transport, expressed by the diameter of the largest particle that can e moved. Depends on flow and speed.
Competence
Measure of amount of solid material a stream has the potential to transport, normally expressed as volume of material passing a given time interval.
Capacity
A type of stream drainage pattern that reflects the underlying geologic structure or topography. It is the most common drainage “tree like” pattern and numerous. Random merging of streams, tributaries joining larger streams irregularly but always at an angle of 90 or less. whose underlying structure does not control the pattern evolution.
Dendritic drainage pattern
This team pattern develops in response to underlying structure containing alternating bands of tilted hard and soft rocks, long parallel streams cut into soft rocks and parallel stream jointed by short right angle 90 degree segments
Trellis drainage pattern
Water follows digging deeper in entrenched “”
Meanders
Down Cutting and V shaped heads to the upper ends of a valley, rapid speed and volume. Area.
Valley deepening .
Lateral erosion by a meandering stream. Area.
Valley widening
Headward erosion. (Lower end lengthens valley.) delta formation (deposition happens seaward in quiet waters) (linear)
Valley lengthening.
William Davis theory of landform formation. (geomorphology cycle) “cycle of erosion” stages.
Youth
Maturity
Old age
Rejuvenation
Surface is uplifted rapidly, erosion has little time till uplift is completely flat land far above sea level. What stage is this?
- Youth.
Equilibrium condition, smooth profiles, stream meanders. Extensive drainage. System. Absence of initial surface. what stage?
2nd maturity
Slopes absent. Extensive floodplains. Flat features. Landscape “peneplain” almost plain. Why stage? Entrenched Meanders.
3rd old age
Raise land, interrupt cycle at any stage. Reenergize system initiates period of down cutting and cycle restarts. What stage?
Rejuvenation
Flat surface is uplifted, incised by fluvial erosion into slopes and valleys then denuded till its flat surface if low elevation again.
Geomorphic cycle -William Davis
