Starter What has happened to Pablo now Whereabouts

Starter: What has happened to Pablo now? Whereabouts on the River Tees do you think he is? Pablo © Copyright peter robinson The River Tees Darlington Just north of a sharp river bend with the opposite bank in North Yorkshire Grid Reference: NZ 257130

Learning Objectives • To know what the middle course of the River Tees is like. • To understand how meanders develop.

Spot the difference! How has the river landscape changed from the upper to the middle course? The River Tees, Milburn The infant river in the vicinity of Fall Crag. © Copyright Andrew Smith watch this clip from 12: 31 to 14: 10 © Copyright Bill Henderson Piercebridge

Task 1: Describe what the river is like in the middle course: © Copyright Bill Henderson Piercebridge

What is a meander? How do they develop? watch this clip from 6: 30 to 7: 53

How do you think Pablo helped to shape this meander?

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Tasks: 2. Draw a cross section diagram to show what happens at a meander. Make sure you include the following labels: • River cliff • Slip-off slope • Area of deposition • • Undercutting Inner bend Outer bend Fastest velocity 3. Challenge: Can you add labels to explain how Pablo the pebble has helped to create the meander?

Tasks: 2. Draw a cross section diagram to show what happens at a meander. Make sure you include the following labels: • River cliff • Slip-off slope • Area of deposition • • Undercutting Inner bend Outer bend Fastest velocity 3. Challenge: Can you add labels to explain how Pablo the pebble has helped to create the meander? 3. Complete the activity on worksheet / firefly to show an ox-bow lake forms.

Oxbow lakes

Draw the following four diagrams in the correct order of oxbow lake formation. Match 3 of the diagrams with the most appropriate explanation from ‘A’, ‘B’ and ‘C’. 1. 2. XX 3. XX 4. X X= erosion on the outside of the meander bend A. The river floods and erodes through the thin meander neck. The river now takes the easier, straight course. The meander loop is left as an oxbow lake. B. The river meanders. The fastest flow is therefore on the outside of the bend. This fast current erodes the meander neck through the processes of erosion. C. The meander neck is further eroded until only a thin piece of land separates the two channels.

Plenary: River racing! On your i. Pad, plot the route of your dinghy along the river channel. Remember you must stay in the river!