rivers

• What is a confluence?

  Where a tributary joins the larger river.
• What is deposition?

  When the river drops the material it carries.
• What is a tributary?

  A small stream that joins a larger river.
• What is a drainage basin?

  Area of land drained by a river and its tributaries.
• What is the river source?

  The start of a river.
• What is a river mouth?

  Where a river enters the sea.
• What are the 3 stages of a river?

  Upper course, middle course, lower course.
• What is the long profile of a river?

  The gradient of a river from source to mouth.
• How does the long profile change?

  It goes from steep to flat from upper to lower course.
• What is the cross profile of the river?

  The side to side cross-section of a river channel.
• What is erosion?

  Wearing away and removing rock and soil.
• What is lateral erosion?

  Erosion that goes side to side.
• What is vertical erosion?

  Erosion that goes downwards.
• What is hydraulic action?

  Erosion from the force of water hitting beds and banks.
• What is abrasion?

  The load hitting against the beds and banks dislodging material.
• What is solution?

  Soluble particles dissolved into the river.
• What is attrition?

  Rocks smashing together and breaking into smaller particles.
• What is transportation?

  The movement of sediment by the river.
• What are the 4 types of river transport?

  Solution, suspension, saltation, traction.
• What is suspension?

  Fine solid material held in water while moving.
• What is saltation?

  Particles bouncing down the river bed.
• What is traction?

  The rolling of boulders and pebbles along the river bed.
• What sediment size is associated with suspension?

  Smallest sediments, called alluvium.
• What sediment size is associated with traction?

  Largest sediments, often pebbles and boulders.
• What is a waterfall?

  Sudden descent of a river over a steep slope.
• How does a waterfall form?

  Hard rock on top of soft rock erodes, creating a drop.
• What happens on the outside bend of a meander?

  Lateral erosion takes place, forming a river cliff.
• What happens on the inside bend of a meander?

  Deposition takes place, forming a slip-off slope.
• What is a plunge pool?

  A deep pool at the bottom of the waterfall.
• How is a plunge pool created?

  Through vertical erosion, hydraulic action, and abrasion.
• What is a gorge?

  A narrow, steep-sided valley.
• What landforms are formed by deposition?

  Floodplains, levees, and estuaries.
• What is a floodplain?

  Large flat areas of land beside a river.
• How does a floodplain form?

  Silt and alluvium are deposited during floods.
• What is a levee?

  Embankment of sediment along the bank of a river.
• How does a levee form?

  Heavy material is deposited at the river's edge during floods.
• What landforms form by erosion and deposition?

  Meanders and oxbow lakes in the middle course.
• What is a meander?

  A pronounced bend in a river.
• What is a thalweg?

  The line of the fastest river flow.
• Where is a thalweg located?

  It swings to the outside bend of a river.