Velocity

• Theory:

  Differences in velocity can be linked to differences in friction in the upper and lower courses of the river.
• Upper Course:

  Erosion processes like hydraulic action and abrasion are not very effective here. There is a small CSA of 0.14m^2. This means proportionally more water is in contact with the channel.

  The channel is also rough in nature. This results in higher levels of friction and lower velocities (0.2m/s)
• Lower Course:

  Erosion processes like hydraulic action and abrasion are very effective here.

  There is a large CSA of 0.314m^2. This means proportionally less water is in contact with the channel.

  The channel is also smoother in nature. This results in lower levels of friction and higher velocities (1.2m/s)