Rivers

• Source


  The place where a river starts, usually in an area of highland.

  
• Mouth


  The place where the river ends, where it meets the sea.

  
• Watershed


  An area of highland which forms a barrier between 2 drainage basins.

  
• Tributary


  A smaller river which joins a larger river.

  
• Confluence


  The point at which 2 rivers meet.

  
• Catchment


  The area where water drains into a drainage basin.

  
• Drainage basin


  The area of land drained by a river.

  
• Condensation


  When a gas cools and turns into a liquid. This forms clouds at high altitudes.

  
• Transpiration


  When plants release water vapour from their bodies.

  
• Precipitation


  The fancy word for rain, sleet, snow, hail etc

  
• Evaporation


  When a liquid turns to a gas and rises.

  
• The Hydrological (Water) Cycle

  This cycle shows how water moves between the land, seas and atmosphere via precipitation, evaporation etc

  
• Upper course


  This is the name given to the start of a river's journey, here it is small, youthful and full of energy.

  
• V-Shaped valleys


  These are formed in the upper course of a river due to vertical erosion.

  
• Interlocking spurs


  These are formed in the upper course of the river as it flows downhill and winds its way between harder and softer rock.

  
• Waterfalls


  These are formed in the upper course of a river when it flows over hard and soft rock. The soft rock is cut back more quickly than the hard rock and a plunge pool is formed. This creates overhangs which collapse due to gravity.

  
• Plunge pool


  This is a feature formed at the bottom of a waterfall, it is created by the force of the water hitting the riverbed. It is deepened by corrasion between the boulders.

  
• Steep-sided gorge


  This is a feature left behind when a waterfall retreats upstream.

  
• Vertical erosion


  This is the type of erosion that occurs mostly in the upper course of a river, after it has used most of its energy to overcome the force of friction.

  
• Lateral erosion


  This is the type of erosion that occurs mainly in the lower course of a river, it is erosion in a sideways direction.

  
• Middle course


  This is the middle section of the river's journey.

  
• Meanders


  Bends in the river that occur in the middle course.

  
• River beach/slip-off slope


  This is a feature formed on the inside bend of a meander due to deposition (due to low velocity and high friction).

  
• River cliff


  This is a feature formed on the outside of a meander where the river erodes the banks through hydraulic action and corrasion.

  
• Meander migration


  This is the name of the process in which a meander moves and becomes more curvy due to constant erosion and deposition.

  
• Erosion


  This is the destructive action of the water in the river which wears away land.

  
• Ox bow lakes


  This is a feature formed when the neck of a meander narrows so much that the river simply cuts through.

  
• Lower course


  This is the last section of a river's journey, here it is large and fast flowing.

  
• Levees


  These are natural barriers formed by the continuous flooding onto the flood plain. The river deposits heavier materials at the front and lighter materials further away.

  
• Floodplain


  This is a feature formed when the river floods and deposits sediment. These are usually very fertile.