Waterfall Formation

• What is the main topic discussed in the study material?

  Waterfall formation
• Why are there fewer waterfalls near the speaker's location?

  Because they live near the lower course of the river
• How many stages are there in waterfall formation?

  Four stages
• What are the two types of rock mentioned in waterfall formation?

  • More resistant rock (M R)
  • Less resistant rock (L R)
• What does M R stand for in the context of rock types?

  More resistant rock
• What does L R stand for in the context of rock types?

  Less resistant rock
• What type of erosion occurs in the upper course of the river?

  Vertical erosion
• What is the process called that erodes less resistant rock?

  Hydraulic action
• What does hydraulic action refer to?

  The force of water breaking down rock
• How does the velocity of water change as it flows over a step in a waterfall?

  The velocity increases
• What is a plunge pool?

  A deep pool formed at the base of a waterfall
• What happens to the less resistant rock as the waterfall flows over the step?

  It gets eroded away
• What is the result of the erosion of the less resistant rock?

  It creates a plunge pool
• What happens to the more resistant rock over time?

  It becomes overhanging and eventually breaks away
• What is the term for the backward movement of a waterfall?

  Retreat
• What formation is left behind after a waterfall retreats?

  A gorge
• What happens to the collapsed material at the bottom of the plunge pool?

  It gets eroded over time
• What are the four stages of waterfall formation?

  1. Initial vertical erosion in the upper course
  2. Erosion of less resistant rock by hydraulic action
  3. Formation of a plunge pool
  4. Retreat of the waterfall and formation of a gorge
• What processes contribute to the erosion of rocks in waterfall formation?

  • Hydraulic action
  • Abrasion
• What color is used to represent more resistant rock in the drawing?

  Dark brown
• What color is used to represent less resistant rock in the drawing?

  Orange
• Why is the plunge pool considered the most dangerous section of a waterfall?

  Because of its depth and fast-moving water
• What is the relationship between the speed of water and hydraulic action?

  Faster water increases hydraulic action
• What happens to the rocks in the plunge pool over time?

  They get worn down by abrasion
• What is the significance of the term "long profile" in relation to rivers?

  It describes the gradient of the river from source to mouth
• How does the presence of boulders in the plunge pool affect erosion?

  They contribute to abrasion and further erosion
• How does the process of waterfall formation illustrate the concept of erosion?

  It shows how different rock types erode at different rates