coastal landscapes

• what is a constructive wave?

  a wave which has a stronger swash than backwash so constructs the beach, occurs in calm conditions, low wave height long wave length
• what is a destructive wave?

  it has a stronger backwash than swash which erodes the beach, it has a higher frequency of heat waves that are higher but smaller length.
• what is hydraulic action?

  The sheer power of waves crashing against the cliff pushing air into the cracks. This then causes cliffs to break apart.
• what is attrition ?

  when rocks knock against each other becoming rounder and smaller
• what is abrasion?


  when pebbles grind along the river bank acting like sand-paper
• what is solution?

  when the water dissolves certain types of rock e.g limestone
• What is traction

  large, heavy pebbles are rolled along the river bed.
• what is saltation ?

  pebbles are bounced along the river bed.
• what is suspension?

  when lighter sediment is carried within the water.
• what is solution (transportation)

  the transport of dissolved chemicals.
• what is deposition?

  rivers dropping the sediment it is carrying.
• factors leading to deposition?

  • shallow water
  • volume of water decreasing
  • river loosing energy
• what is a drainage basin ?

  A drainage basin is the area of land around the river that is drained by the river and its tributaries
• definitions ?

  • Watershed - the area of high land forming the edge of a river basin
  • Confluence - the point at which two rivers meet
  • Tributary - a small river or stream that joins a larger river
  • Channel - where the river flows
• what’s the difference between a rivers long profile and cross profile ?

  Long profile shows the change over the course of the river, cross profile shows the cross section of a rivers channel and valley.
• what is the upper course of the river like?

  1. steeper gradient
  2. shallow and narrow channel
  3. there’s an increase in lateral erosion
• what happens in the middle course?

  1. There is some vertical erosion but more lateral erosion
  2. channel becomes wider and deeper
• what happens in the lower course of the river ?

  channel is at its widest and deepest, there is more deposition as river looses energy
• how is a waterfall formed?

  1. soft rock erodes faster creating a step in the soft rock.
  2. as erosion continues, the hard rock is undercut forming a waterfall.
  3. abrasion and hydraulic action create a plunge pool.
  4. overtime the overhang is no longer supported and collapses.
• what’s a gorge ?

  when waterfalls continue to erode they retreats up stream leaving a steep sided gorge.
• what are interlocking spurs?

  when the river has to wind around harder rock in the v-shaped valley.
• how is a meander formed ?

  erosion forming river cliffs on the outside and deposition forming slip off slopes on the inside and the water travels faster on the outside.
• how is an oxbow lake formed ?

  1. the process of deposition and erosion continues.
  2. The erosion narrows the neck and the meander.
  3. during a flood water takes the fastest course, cutting across to form a straighter course,
  4. deposition fills old meander to leave an oxbow lake.
• how does a floodplain form?

  due to erosion and deposition