Info 3: Measuring the speed of flow

The graph indicates that at stream order 1 the velocity is higher than at order 2. The additional water in the channel should indicate a greater speed but the slope of the stream channel is steeper near the source and therefore has more gravitational potential energy. The presence of rock pools and boulders in order 2 sections would also influence the average readings that were taken.

At order 3 the volume of water has increased and this would be a reflection in the greater discharge in the channel and reduction in the friction across the wetted perimeter. At order 4 the reduction in discharge and low gradient influence the speed of flow. Additionally at Bossington Beach the river seeps through the boulder ridge, which slows the discharge rate into the sea.