Theory question 204
Rivers and River Landforms(a) With the aid of annotated diagrams, describe the various stages of a river course (b) Mention four ways in which rivers are of importance to man
Show the model answer
(a) Long-profile diagram labelled upper, middle and lower course with cross-sections.
Upper (youthful) course: steep gradient, fast flow; vertical erosion forms narrow V-shaped valleys, gorges, waterfalls, rapids, potholes and interlocking spurs.
Middle (mature) course: gentler gradient; lateral erosion widens the valley; meanders, river cliffs and slip-off slopes; some deposition.
Lower (old) course: very gentle gradient; deposition dominant; wide flood plain, levees, large meanders, ox-bow lakes, braiding, delta or estuary.
(b) Water for domestic, industrial and farm use (irrigation); transport; fishing; HEP; tourism and recreation; boundaries; fertile flood plains.
Draw both the long profile and valley cross-sections.