Chaning Channel Characteristics

Question 1

What is the channel cross profile?

Answer 1

is a view of the river bed and banks from one side to the other at any one point on it course.

Question 2

Upper course

Answer 2

narrow and uneven, due to presence of deposted boulders.

Where both banks are being eroded channels tend to be broadly rectangular in shape.

Question 3

Middle course

Answer 3

starts to meander,

channel becomes asymmetrical on the river bends but mainly smooth and symmetrical on the straight stretches.

Question 4

Lower course

Answer 4

widens and deepens further

banks of deposition and eyots (islands of deposition) can disrupt the shape of the channel cross-section, leading to a braided channel.

Sometimes embankments called levees can be seen on either side of the channel.

Levees can also be man-made.

Question 5

Bradshaws model

Answer 5

The Bradshaw Model is a geographical model which describes how a river’s characteristics vary between the upper course and lower course of a river.

Question 6

What increases according to Bradshaw?

Answer 6

Discharge
Occupied channel width
Channel Depth
Average Velocity
Load capacity
Hydraulic Radius

Question 7

What decreases according to Bradshaw?

Answer 7

Load Particle size
Channel bed roughness
Slope
Turbulence and friction

Question 8

What is Discharge?

Answer 8

Total volume of water flowing through a channel at any given point and is measured in cubic metres per second (cumecs).