What is river rejuvenation and what landforms does it create?

Rejuvenation, often caused by a fall in sea level or uplift of land, increases a river's potential energy and erosive power. Downstream from the point of rejuvenation, the river begins to cut downwards more vigorously into its own floodplain. This renewed vertical erosion leads to the formation of knickpoints, which are sharp breaks in the river's longitudinal profile, often seen as waterfalls or rapids, that migrate upstream. Existing meanders become incised meanders or entrenched meanders, where the river cuts deeply into the bedrock while maintaining its sinuous course. Furthermore, the old floodplain is left standing as elevated river terraces on either side of the newly deepened valley. The overall effect is a deepening of the river valley and the creation of a younger, more energetic landscape within an older one.