River Rejuvenation

River Rejuvenation

When a river receives ADDITIONAL ENERGY and begins to erode vertically again.

Knick Point (rejuvenation)

A sharp break/change in the river's gradient at the OLD BASE LEVEL (old sea level), formed after the land is uplifted or sea level drops. A waterfall often forms here. Example: Uvongo Falls, KZN.

Valley within a valley

A rejuvenation landform: a new, narrower, deeper valley cut within the original wider valley. The old valley sides form terraces above the new valley.

River Terraces

Step-like flat surfaces along the sides of a river valley, formed as the rejuvenated river cuts downward through its own floodplain. The old floodplain becomes the terrace.

Incised Meanders

Deep, steep-sided meanders cut into the landscape when a rejuvenated river cuts downward through its existing meanders. The meander pattern is preserved but is now deeply entrenched.

What three landforms result from rejuvenation?

1. Knick point (waterfall),

2. Valley within a valley / River terraces,

3. Incised meanders.

Reasons for River Rejuvenation

Uplift of the land

Drop in the sea level

Dramatic rise in amount of rainfall

Stream piracy

What is Isostatic uplift?

Rising of the land