Download The variations of channel geometry

Study of Stream Channel
The variations of channel
geometry
Group 4
Discussion Topic
1. Summarize and describe
the main findings the
variations of channel
geometry.
River
Upper
course
(Area A1&2)
Middle
course
(Area B3&4)
Lower
course
(Area C5&6)
Channel geometry
e.g. the width, depth, length, gradient
and wetted perimeter
Upper
course
Middle
course
Lower
course
Area A2
Area B4
Area C5
Compare of the channel Geometry
Area A2
Area B4
Area C5
Average
depth(cm)
17.1
13.347
12.45
Width(cm)
386
760
2060
Wetted perimeter
(m)
8.2
7.6
20.6
Average
gradient
4 degrees
45 min
0 degrees 3 degrees
50 min
10 min
Upper Course (Area A2)
Middle course
Area B4
Lower course (Area C5)
Factors affecting geometry

Upper course
Width: less lateral erosion
narrow
Depth: serious vertical erosion
deep
Length: straight river course
short
Gradient: serious erosion
steep slope
Wetted perimeter: narrow

Middle course
Width: more lateral erosion than upper
course
Depth: less vertical erosion than the upper
course
Length: meanders exist
longer than upper course
Gradient: less erosion
less steep slope
Wetted perimeter: wide

Lower course
Width: serious lateral erosion
wide
Depth: less vertical erosion and
deposition
shallow
Length: ** more meanders exist
longest
Gradient : deposition
gentle slope
Wetted perimeter :very wide
Conclusion
Description of channel geometry
gradient
Velocity Depth / Width / Length
A
Steep
Rapid
B
Less
steep
Slow
C
Gentle
Rapid
Deep (vertical erosion)
/ Narrow / Short
Medium / Medium /
Medium
Shallow / Wide / Long
The End~~ Thank you!