Channel Types Flashcards
1
Q
What is sinuosity?
A
- measurement of how meandering/sinuous a river is
2
Q
What are the 3 types of channels?
A
- straight
- meandering
- braided
3
Q
What are the characteristics of islands + bars?
A
Islands:
- vegetated
- long-lived
Bars:
- unvegetated
- less stable
- short-lived
4
Q
What factors form braided channels?
A
- steep channel gradient
- large proportion of coarse material
- easily eroded bank material
- v. variable discharge
5
Q
What are the 3 main factors the wavelength of a meander is dependent upon?
A
- channel width
- discharge
- nature of bed + banks
6
Q
What are meander + channel characteristics?
A
- meander belt + 14x channel width
- pools + riffles occur 6x channel width apart
- meander wavelength 6-10x channel width + discharge
7
Q
How do meanders change over time?
A
- may migrate downstream + erode river cliffs
- may migrate laterally + erode floodplain
- may exaggerate + become ox-bow lakes
- may become intrenched or ingrown
8
Q
What is a straight channel?
A
- channel w a sinuosity of < 1.5
9
Q
What is a meandering channel?
A
- channel w a sinuosity of > 1.5
10
Q
What are braided channels?
A
- channels divided by islands + bars
