Causes of river rejuvenation

River rejuvenation is the renewal of the erosive activity of the river within its old valley.

• Heavy rainfall (climate change) in the catchment areas causes increase in volume of water in the river. This increases the erosive activity resulting into rejuvenation.
• River capture/piracy: As the river cuts back, it breaks into the adjacent valley and captures a nearby stream. This increases the volume of water in the pirate river channel leading to rejuvenation
• Regional uplift along the river course e.g. through faulting causes a gradual steepening of the river’s gradient. This increases its velocity (speed) and its erosive activity leading to rejuvenation.
• Isostatic and Eustatic re-adjustments. Negative changes in the sea level (fall in sea level) create a knick point close to the coast resulting into increase in the river gradient, increased speed and its erosive activity.
• Glaciation in the ice caps and ice sheets. This reduces the amount of water reaching oceans such as the Indian Ocean. This results into a fall in the sea – level and lowering of the base-level of rivers. A steep gradient is produced and therefore, the velocity of the river and erosive load leads to an increase in the energy and erosive activity