The process of Rejuvenation & its landforms

Question 1

Explain the process of Rejuvenation and its landforms.

Answer 1

The process:

Rejuvenation allows a river to resume vertical erosion:

A river is said to be rejuvenated if its base level is lowered. This can be caused by either the ground level rising (crustal uplift) or by a drop in sea level.

The drop in base level gives the river greater potential energy, increasing its vertical erosion potential.

The long profile of the river is extended and a knickpoint (a sharp change in gradient, often a waterfall) will form and mark the junction between the original long profile and the new one.

The landforms:

There are distinctive landforms associated with rejuvenation:

• River terraces are former flood plains which have been left above the level of present-day flooding following increased vertical erosion.
• Incised meanders are formed when a river keeps its meandering course as vertical erosion increases. The result is a deep, winding valley with steep sides. The river is left far below the level of the former flood plain.