Geomorphology Flashcards
1
Q
Catch meant area
A
The drainage area that supplies water to the river
2
Q
Drainage Basin
A
Area drained by a river system
3
Q
Source
A
Place where’s a river begins
4
Q
Mouth
A
Where the river flows into a sea or lake
5
Q
Surface runoff
A
Rainwater flowing over the surface
6
Q
Watershed
A
High ground separating one drainage basin from adjacent drainage basin
7
Q
Stream or river network
A
Single streams and rivers that are connected
8
Q
Tributaries
A
Single river channel forming the stream network
9
Q
Confluence
A
Point where one river in the network joins another
10
Q
Interfluves
A
Ridges of high ground between individual channels
11
Q
Overland flow
A
Rainwater flowing over the surface
12
Q
Channel flow
A
Water flowing in a river channel
13
Q
Throughflow
A
Water flowing through the soil
14
Q
Permeable rocks
A
Rocks that allow water to seep in
15
Q
Groundwater
A
Underground water
16
Q
Groundwater flow
A
Water flowing through underground rocks
17
Q
Impermeable rock
A
Rock without pore spaces or cracks through which water is able to pass
18
Q
Water table
A
Upper surface of the groundwater
19
Q
Base flow
A
Groundwater that seeps into a river
20
Q
Geology
A
Rock structure
21
Q
Topography
A
Relief
22
Q
Radial pattern
A
Develops on a fine where streams flow outwards and downhill
23
Q
Trellis pattern
A
Forms on inclines strata that are unequal resistant to erosion
24
Q
Strata
A
Rock layers
25
Rectangular pattern
Forms on igneous rock that has joints and cracks, stream develops right angle bends where joints meet
26
Centripetal pattern
Streams flow into a central pan or low lying area
27
Dendritic pattern
Tree like appearance, forms on rocks with similar hardness in an are with a similar gradient
28
Parallel pattern
On a surface that slopes uniformly but is fairly steep
29
Deranged pattern
No apparent drainage pattern
30
Stream order
The category of a stream in a network determined by the order of the streams feeding into it
31
Discharge
The amount of water flowing in a river channel past a point in a given time
32
Laminar flow
Water flowing in sheets
33
Turbulent flow
Water flowing in a bubbling motion
34
Longitudinal profile
Visual representation of the gradient down which the river flows
35
Transverse profile
Section drawn transversely across the valley at right angles to the river
36
Upstream
Towards the source
37
Downstream
Towards the mouth
38
Temporary base levels
Changes in gradient along the course of a river where vertical erosion of the river is slowed
39
Vertical erosion
Erosion downwards
40
Permanent base level or ultimate base level
Lowest level to which a river will erode the land
41
Gorge
Deep, steep sided valley
42
Erosion
The wearing away and removal of weathered rock material from the river channel
43
Fluvial landforms
Landforms created by a river
44
Spurs
Ridges of high ground between individual channels
45
Rapids
A resistant layer of rock causes slight changes in gradient and turbulent flow
46
Waterfalls
River crosses a horizontal layer of resistant rock
47
Headward erosion
River lengthens it’s course by cutting back upstream above its original course
48
Hydraulic action
Force of flying water loosening pebbles, stones, sand and silt from the sides and bed of channel
49
Abrasion
Particles of sand and salt that are carried by the river scratch and where away the bed and sides of the channel
50
Traction
Boulders in large rocks are pushed and rolled along the river bed
51
Saltation
Smaller rocks and stones are bounced along the river bed
52
Suspension
Salts and very small particles are carried within the flow of the water
53
Sheet flow
Water flowing down slope in thin sheets
54
Mass movement
Movement down slope of weathered material
55
Meander’s
Bends in the river channel
56
Alluvial fans
Deposition as the river flows off the mountains on to the flatter plains
57
Flood plain
Flat valley floor
58
Alluvium
Fertile silt deposited by a river
59
Levees
Raised banks of a river
60
Braided streams
Deposits of alluvium form islands in the middle of the channel, splitting the river into separate channels
61
Oxbow lakes
A meander that is cut off when the river takes a new course across the neck of a meander loop
62
Meander scars
Dried up oxbow lakes
63
Distributaries
A single channel divides into a number of smaller channels that do not re-join; In other words, opposite of a tributary
64
Velocity
Speed of a river
65
Graded river
A river that has achieved equilibrium between its gradient, volume and channel shape, so that the river has just sufficient energy to flow, with erosion rates in balance with the deposition rates
66
Over graded rivers
Rivers that have excess energy and therefore erode their channels
67
Under graded rivers
Rivers that do not have enough energy to flow and to transport their load; they will deposit some of their load
68
Rejuvenated river
A river receives additional energy and begins to the road vertically
69
Isostatic uplift
Rising of the land
70
Knickpoint
Sharp change in gradient a long the course of a river located at the old sea level after isostatic uplift or a drop in sea level has occurred
71
Carrying capacity
Amount of material the river has the energy to transport
72
Valley within the valley
Rejuvenated river begins to erode a new Valley within the old one
73
River terraces
Steps that show the level of the valley floor prior to rejuvenation
74
Knickpoint waterfall
A waterfall created by a sharp change in gradient
75
Entrenched or incised meanders
A rejuvenated river maintains its meandering course, but vertical erosion leads to meanders between steep valley sides
76
Ingrown meanders
A meander that cuts sideways into the bank so that there is a slight overhang above the stream
77
Captor stream
More energetic river that eroded through the watershed and captured another river
78
Captive stream
Less energetic river that was captured by the captor
79
Misfit
Part of the river has lost its head waters
80
Elbow of capture
Point where capture occurred; the captive changes direction and flows into the captor
81
Windgap
The part of the original Rivervalley, between the alba and misfit, now dry and filled with gravel
82
Abstraction
Process whereby the watershed becomes lower and its position shifts
83
Superimposed drainage pattern
A river develops a pattern on a surface that’s has eroded overtime, so now the river is flowing on the older rocks or structures that have been uncovered
84
Antecedent drainage pattern
After the river formed, folding or faulting occurred, but the river maintained it’s pattern, cutting a gorge through the land that has been uplifted
85
Lag time
The period between maximum precipitation and peak discharge
