RIVER STUDIES

1. RIVER STUDIES Channel processes and features Valley slope processes and landforms

2. Satellite view of river drainage, Middle East

3. Microscale drainage basin

4. Upper valley characteristics

5. Upper valley characteristics

6. Upper valley characteristics “V”shape valley, vertical erosion dominant

7. Upper valley characteristics “V”shape valley, vertical erosion dominant Interlocking spurs

8. Upper valley characteristics “V”shape valley, vertical erosion dominant Interlocking spurs Slumping and landslides - very active hillslopes

9. Upper valley characteristics “V”shape valley, vertical erosion dominant Terracettes formed by soil creep Interlocking spurs Slumping and landslides - very active hillslopes

10. Upper valley characteristics “V”shape valley, vertical erosion dominant Terracettes formed by soil creep Narrow, shallow channel, low velocity and discharge Interlocking spurs Slumping and landslides - very active hillslopes

11. Upper valley characteristics “V”shape valley, vertical erosion dominant Terracettes formed by soil creep Narrow, shallow channel, low velocity and discharge Interlocking spurs Slumping and landslides - very active hillslopes Large bedload derived from upstream and from valley sides

12. Interlocking spurs, Robinson, Lake District A typical upper course valley with interlocking spurs, steep valley sides and active slope processes

13. Choked runnel, N. Pennines Ephemeral stream or runnel - water present only during high rainfall events

14. Choked runnel, N. Pennines Ephemeral stream or runnel - water present only during high rainfall events Debris brought downslope towards channel - dropped when water disappears after storm

15. Choked runnel, N. Pennines Vertical erosion creating steep, bare slopes vulnerable to further erosion - an example of positive feedback in a slope system Ephemeral stream or runnel- water present only during high rainfall events Debris brought downslope towards channel - dropped when water disappears after storm

16. River load in upper course Load is dumped in summer due to the low discharge unable to carry the c________and c__________of load at higher flow levels

17. River load in upper course Load is dumped in summer due to the low discharge unable to carry the capacity and competence of load at higher flow levels

18. River load in upper course Load is dumped in summer due to the low discharge unable to carry the capacity and competence of load at higher flow levels

19. River load in upper course Boulders are large and semi-rounded, due to attrition within the loadand abrasion with the stream bed and banks Load is dumped in summer due to the low discharge unable to carry the capacity and competence of load at higher flow levels

20. Rapids in the Upper Tees Valley

21. Rapids in the Upper Tees Valley Rapids are mini-waterfalls Protruding bands of more resistant strata create steps over which rapids fall - the river bed is ungraded

22. Rapids in the Upper Tees Valley Rapids are mini-waterfalls Shallow, slow flowing river due to large amount of friction. Protruding bands of more resistant strata create steps over which rapids fall - the river bed is ungraded

23. Rapids in the Upper Tees Valley Rapids are mini-waterfalls Shallow, slow flowing river due to large amount of friction. Wetted perimeter is large compared to cross sectional area of water - resulting in a low ???????????? Protruding bands of more resistant strata create steps over which rapids fall - the river bed is ungraded

24. Rapids in the Upper Tees Valley Rapids are mini-waterfalls Shallow, slow flowing river due to large amount of friction. Wetted perimeter is large compared to cross sectional area of water - resulting in a low hydraulic radius(low efficiency) Protruding bands of more resistant strata create steps over which rapids fall - the river bed is ungraded

25. High Force waterfall, R. Tees

26. High Force waterfall, R. Tees Huge step in river bed due to igneous intrusion of dolerite into the limestone.

27. High Force waterfall, R. Tees Huge step in river bed due to igneous intrusion of dolerite into the limestone. Plunge pool where the dolerite wall is undercut, causing rockfalls and recession of the waterfall upstream

28. High Force waterfall, R. Tees Huge step in river bed due to igneous intrusion of dolerite into the limestone. Waterfall creates gorge as it recedes upstream by eroding the base and neck Plunge pool where the dolerite wall is undercut, causing rockfalls and recession of the waterfall upstream

29. High Force waterfall, R. Tees The long profile will be graded over time Huge step in river bed due to igneous intrusion of dolerite into the limestone. Waterfall creates gorge as it recedes upstream by eroding the base and neck Plunge pool where the dolerite wall is undercut, causing rockfalls and recession of the waterfall upstream

30. Headward erosion, Offa’s Dyke This is amazing!!

31. Headward erosion, Offa’s Dyke Spring erodes ground over which it flows and lubricates base of cliff, causing slumping and headward erosion

32. Headward erosion, R. Colorado

33. Headward erosion, R. Colorado River seeps out from spring at base and undermines steep cliff, causing rockfalls and headwall recession

34. Headward erosion, R. Colorado Rivers erode in a headward direction, eating back into plateau River seeps out from spring at base and undermines steep cliff, causing rockfalls and headwall recession

35. Potholes in R. Wharfe Smooth sculpturing of rock by abrasion, showing evidence of water levels during high discharge events Vertical erosion is dominant

36. Close-up of potholes

37. Close-up of potholes

38. Close-up of potholes Circular potholes due to eddying motion when river energy is high

39. Close-up of potholes Circular potholes due to eddying motion when river energy is high Potholes will join together by abrasion, and deepen by verticalerosion

40. Close-up of potholes Circular potholes due to eddying motion when river energy is high Potholes will join together by abrasion, and deepen by verticalerosion Load is picked up and used to scour or abrade pothole. Load itself becomes rounded by attrition

41. Potholes, human scale!!

42. Middle course, R. Tees

43. Middle course, R. Tees Valley opens out, more gentle slopes, wider valley bottom

44. Middle course, R. Tees Valley opens out, more gentle slopes, wider valley bottom First signs of meanders

45. Middle course, R. Tees Valley opens out, more gentle slopes, wider valley bottom First signs of meanders Floodplain

46. Middle course, R. Tees Valley opens out, more gentle slopes, wider valley bottom First signs of meanders Floodplain River channel wider, deeper, greater velocity and discharge

47. Meander, R. Lavant, Chichester

48. Meander, R. Lavant, Chichester Floodplain

49. Meander, R. Lavant, Chichester Floodplain Point bar deposits on the inner meander bend where there is low energy

50. Meander, R. Lavant, Chichester Floodplain Point bar deposits on the inner meander bend where there is low energy Steep bank known as the river bluff or cliff, caused by concentrated erosion due to the