rivers

• What happens to rainwater after it infiltrates the soil?


  It can move down through the soil due to gravity.
• What is through flow in the context of water movement?

  Through flow is when water moves around the top of the rock because it cannot penetrate it.
• What is percolation?


  Percolation is when water moves into the rock due to gravity and can be stored in an aquifer.
• What type of rock is a good aquifer?


  Soft rock, such as chalk, is a very good aquifer.
• What is groundwater flow?


  Groundwater flow is when some water flows through the rock.
• What is vegetation interception?


  Vegetation interception is when rainwater is blocked by trees before it reaches the soil.
• How does vegetation interception help prevent flooding?


  It slows down the process of water reaching the soil, reducing the risk of flooding.
• What is surface runoff?


  Surface runoff occurs when water collects on the surface due to impermeable or saturated ground.
• What is the source of a river?


  The source is the beginning of the river, usually found in the mountains.
• What is the mouth of a river?


  The mouth is the end of the river where it meets the sea.
• What is a tributary?


  A tributary is a smaller river that joins a larger river.
• What is a confluence?


  A confluence is the meeting point of two rivers, such as where a tributary joins a larger river.
• What is a meander?


  A meander is a bend in the river, mostly found in the lower course.
• What are the lower and upper courses of a river?

  The lower course is the downstream section, while the upper course is the upstream section of the river system.
• What is a watershed?


  A watershed is the area surrounding a river system, often marked by a line of mountains.
• What is a drainage basin?


  A drainage basin is the part of land inside the watershed where rainwater will flow into that river.
• What is a V-shaped valley?


  A V-shaped valley is formed in a river's upper course due to downward erosion from freeze-thaw weathering.
• How is a waterfall formed?


  A waterfall forms when a river flows over layers of hard and soft rock, creating a step due to differences in geology.
• What is a plunge pool?


  A plunge pool is formed at the base of a waterfall due to the force of falling water and undercut hard rock eroding the soft rock at the bottom of the plunge pool through abrasion.
• What happens to the hard rock above a waterfall over time?


  The hard rock is undercut and eventually collapses into the plunge pool.
• How does a gorge form?

  A gorge is formed as a waterfall retreats upstream, leaving behind a deep, narrow valley.
• How is a meander formed?


  A meander is formed in a river's lower course due to irregularities in the river that create bends.
• What is an oxbow lake?


  An oxbow lake is formed from a well-developed meander that has been cut off from the river.
• What is a floodplain?


  A floodplain is a flat area found in the lower course of the river, formed by sediment deposition during floods.
• Why is the floodplain good for farming?


  The floodplain is fertile due to the nutrients from sediment deposited during floods.
• What are levees?


  Levees are embankments on the sides of the river formed from sediment deposited during past flood events.
• How do levees form?


  Levees form as sediment is deposited next to the river during flooding events, creating walls at the river's edge.
• Why are levees beneficial?


  Levees help prevent flooding by requiring more water for the river to overflow.
• What are the main river landforms and their definitions?

  • Source: Beginning of the river, usually in the mountains.
  • Mouth: End of the river where it meets the sea.
  • Tributary: Smaller rivers that join a larger river.
  • Confluence: Meeting point of two rivers.
  • Meander: Bend in the river, mostly in the lower course.
  • Watershed: Area surrounding the river system.
  • Drainage basin: Land that drains into a specific river.
• What processes contribute to the formation of waterfalls and gorges?


  • Water flows over hard and soft rock.
  • Erosion of soft rock forms a step.
  • Formation of a plunge pool at the base.
  • Undercutting of hard rock creates an overhang.
  • Retreat of the waterfall creates a gorge.
• What are the characteristics of meanders and oxbow lakes?


  • Meanders: Formed by irregularities in the river, creating bends.
  • Oxbow lakes: Formed from well-developed meanders that are cut off from the river.
• What are the features of a floodplain and levees?


  • Floodplain: Flat area in the lower course, fertile due to sediment deposition.
  • Levees: Embankments formed from sediment during floods, help prevent flooding.