Coastal Landscapes
Erosion is the wearing away of rocks and subsequent transport from that location.
Weathering is the breakdown of rock in-situ.
4 types of coastal erosion are:
Hydraulic Action (Power) – This is when the waves crash against the cliffs and force of the waves
weakens the structure.
Abrasion (Throw) – This is when fragments of rocks are picked up by the waves and thrown
against the cliffs.
Solution (Dissolve) – This happens when weak acid in the sea water chemically attacks the rock,
this only happens when they cliffs are made of limestone and chalk.
Attrition (Bang) – This is when waves carry fragments of rock, known as load, and they bang into
each other. As this happens they become smaller and more rounded. This contrasts the other
processes as it does not break down the coast.
There are three types of weathering processes which are mechanical, biological and chemical.
Freeze thaw weathering is mechanical, animal burrowing is biological, acid rain is chemical, tree root
growth is biological, and animal faeces is biological.
Mass movement is the downward movement of rocks/ sediment under the influence of gravity.
Slumping is what happens after long rainfall and is when rain seeps through permeable rock such as
sandstone. When the permeable rock meets the impermeable rock such as clay, the soil weakens
and the weaker rocks slumps and slides rotationally against the curved surface.
Sliding is the movement of material along a flat surface rather than a curved one. This causes a lot
of damage as large amounts of rock and soil can move very quickly.
Transportation processes:
Traction – the largest particles are rolled along the seabed and waves don’t have enough energy to
pick them up.
Saltation – Bouncing of particles along the sea bed
Suspension – Particles are held up between seabed and water
Solution – Dissolved particles are carried by the waves
Deposition – The dropping of the river load when it has no more energy or power to carry it.
,There are two types of waves – constructive and destructive.
Constructive waves has a stronger swash than backwash so the waves have less energy. These are
low in height and widely spread. 6-9 waves per min.
Destructive waves have stronger backwash than swash and are very powerful waves with a lot of
energy. These waves creates narrow steep beaches and the waves the waves are tall and closely
spaced. 11-15 wave breaks min.
Examples of hard rock are chalk and limestone.
Clay is a soft rock.
There are two types of coastlines. Discordant and Concordant.
Discordant coastlines have bands of resistant and less resistant rock which are perpendicular to
the coastline.
Concordant coastlines have rock parallel to the coastline.
Headland and bays are formed on discordant coastlines.
It happens when the weaker sections of rock are eroded more easily as they are softer as form bays.
The harder rock erodes much slower leaving the rock to protrude out to sea causing a headland.
Erosion is now concentrated on the headland and deposition occurs on the bay.
Wave cut platforms are formed when waves erode against the cliff. It attacks the bottom rock face
to cause a feature called a wave cut notch. The notch is eroded deeper and it can’t support the cliff
above leading it to collapse. This process repeats itself and the cliff line gradually retreats and leave
a rocky feature called a wave cut platform.
Formation of caves, arches and stacks:
1. The headland contains crack and these cracks will be attacked by abrasion and
hydraulic action causing them to deepen over time.
2. Eventually these cracks deepen enough to form caves. These caves will get larger at the
base and weathering at the top will expand it.
3. The cave will eventually break through the headland to form an arch.
4. The arch is widened due to the wave energy.
5. The arch becomes so large that the it cannot hold its weight so collapses.
6. The remaining feature is called a stack which is an isolated column of rock.
7. The stack will eventually collapse to form a stump will be often submerged in the
water.
Longshore Drift:
• Longshore drift is the process of transportation which moves sand along the coast
• Waves approach the sand at angle which is controlled by the prevailing wind (most common
wind direction)
• The swash carries pebbles up the beach and an angle and backwash sends sediment down
the beach at a right angle.
• This results in a zig-zag movement.
,There are two types of beach which are swash aligned and drift aligned.
In swash aligned beaches the waves approach at 90 degrees so there is not longshore drift.
In drift aligned beaches the process of longshore drift will occur.
A spit is a long, narrow finer of sand jutting out from the land.
Formation of a spit:
1. When there is a change is direction of a coast, longshore drift cannot go around the
bend. It loses energy so therefore deposits material.
2. This process repeats and more sediment is dropped.
3. As the sediment builds up it will form a small land which will go to sea. This creates a
spit.
4. It will continue to grow out but strong winds and change in direction of wind will cause
to spit to curve on its tip.
5. The spit is connected to the land but cannot go to the side of the land as the river has
a strong current.
6. Behind the spit calm water develops creating a salt marsh.
Bars
Similar to the development of the spit, longshore drift may cause the spit to go right across the bay
and connecting to headlands trapping a lagoon behind it. This is called a coastal bar.
A bar is formed by a spit growing across a bay of two headlands.
River Landscapes and Processes
Drainage Basin – A drainage basin is an area of land which drains into a river and its tributaries. As the
rain falls, the water will slowly make its way to the main river. This can occur through various ways
within the hydrological cycle.
Watershed – This is the boundary between a drainage basin and the next drainage basin. This is usually
high land such as hills or ridges. Therefore, rain can fall on one side of a hill and drain into a completely
different river to rain on the other side of a hill.
Tributary – This is a smaller stream or river that joins a larger stream or river.
Source – This is the starting point of a stream or river. Often these are springs or lakes found in
mountainous areas where rainfall totals are higher.
Confluence – This is the point at which two streams or rivers meet.
Mouth – This is the point at which a river leaves its drainage basin and flows into the sea. This is also
known as an estuary.
Interception – When part of rainfall is intercepted by Earth’s surface and subsequently evaporated.
Trees, branches, houses: slow down water moving into river.
, Infiltration – The movement of water into the soil from the surface.
Throughflow – Moving of water horizontally beneath land surface until water is saturated. Quite quick
process. If saturated, surface run off occurs.
Percolation – Movement of water past the soil going deep into groundwater and flow into rocks. Slow
process.
Groundwater Flow (Base Flow) – Deeper movement of water through underlying permeable rock
below water table. Very slow movement of water.
Surface Run Off – Water that does not infiltrate will move across the ground as surface run off. This
often happens in urban areas where water hits tarmac. This is a rapid flow of water. Increased by
urbanisation and flooding.
River (Channel) Flow – Water flowing along the river, finally to the sea or another lake or river. Fastest
flow of water in the drainage basin.
Factors impacting rate of infiltration:
• The amount saturation level of the ground. If infiltration capacity of the soil has been reached,
then no infiltration will occur. This will mean the rate will be slow.
• If the gradient of the ground is steep, then infiltration will occur more slowly as the water will
be more likely to move downslope through surface run off.
• If the rock is permeable, this will allow for more infiltration. Whereas if the rock is
impermeable, less infiltration will occur as the soil will be able to hold less moisture and this
will slow the rate of infiltration.
• If there is vegetation in the area, this will break up the soil and allow more infiltration.
Freeze Thaw Weathering:
• Water gets into cracks on the river bank.
• When temperature drops below 0 degrees, water freezes and expands by 9%.
• This puts pressure on the rack and may break it apart.
• This is most common in upland areas in the river’s upper course.
Acid Rain:
• Rainwater contains weak acids.
• When this rain falls on rock such as chalk and limestone it will weaken and break down by
dissolving the rock.
Trees root:
• Seeds fall into cracks.
• When water is present, plants force out and grow.
• Over time, this breaks up rocks or cliff faces.
• Animals, such as burrowing rabbits also do the same.
Factors impacting rate of weathering:
• Hardness of rocks.
• Number of cracks in the rocks.
• Available water.
Erosion is the wearing away of rocks and subsequent transport from that location.
Weathering is the breakdown of rock in-situ.
4 types of coastal erosion are:
Hydraulic Action (Power) – This is when the waves crash against the cliffs and force of the waves
weakens the structure.
Abrasion (Throw) – This is when fragments of rocks are picked up by the waves and thrown
against the cliffs.
Solution (Dissolve) – This happens when weak acid in the sea water chemically attacks the rock,
this only happens when they cliffs are made of limestone and chalk.
Attrition (Bang) – This is when waves carry fragments of rock, known as load, and they bang into
each other. As this happens they become smaller and more rounded. This contrasts the other
processes as it does not break down the coast.
There are three types of weathering processes which are mechanical, biological and chemical.
Freeze thaw weathering is mechanical, animal burrowing is biological, acid rain is chemical, tree root
growth is biological, and animal faeces is biological.
Mass movement is the downward movement of rocks/ sediment under the influence of gravity.
Slumping is what happens after long rainfall and is when rain seeps through permeable rock such as
sandstone. When the permeable rock meets the impermeable rock such as clay, the soil weakens
and the weaker rocks slumps and slides rotationally against the curved surface.
Sliding is the movement of material along a flat surface rather than a curved one. This causes a lot
of damage as large amounts of rock and soil can move very quickly.
Transportation processes:
Traction – the largest particles are rolled along the seabed and waves don’t have enough energy to
pick them up.
Saltation – Bouncing of particles along the sea bed
Suspension – Particles are held up between seabed and water
Solution – Dissolved particles are carried by the waves
Deposition – The dropping of the river load when it has no more energy or power to carry it.
,There are two types of waves – constructive and destructive.
Constructive waves has a stronger swash than backwash so the waves have less energy. These are
low in height and widely spread. 6-9 waves per min.
Destructive waves have stronger backwash than swash and are very powerful waves with a lot of
energy. These waves creates narrow steep beaches and the waves the waves are tall and closely
spaced. 11-15 wave breaks min.
Examples of hard rock are chalk and limestone.
Clay is a soft rock.
There are two types of coastlines. Discordant and Concordant.
Discordant coastlines have bands of resistant and less resistant rock which are perpendicular to
the coastline.
Concordant coastlines have rock parallel to the coastline.
Headland and bays are formed on discordant coastlines.
It happens when the weaker sections of rock are eroded more easily as they are softer as form bays.
The harder rock erodes much slower leaving the rock to protrude out to sea causing a headland.
Erosion is now concentrated on the headland and deposition occurs on the bay.
Wave cut platforms are formed when waves erode against the cliff. It attacks the bottom rock face
to cause a feature called a wave cut notch. The notch is eroded deeper and it can’t support the cliff
above leading it to collapse. This process repeats itself and the cliff line gradually retreats and leave
a rocky feature called a wave cut platform.
Formation of caves, arches and stacks:
1. The headland contains crack and these cracks will be attacked by abrasion and
hydraulic action causing them to deepen over time.
2. Eventually these cracks deepen enough to form caves. These caves will get larger at the
base and weathering at the top will expand it.
3. The cave will eventually break through the headland to form an arch.
4. The arch is widened due to the wave energy.
5. The arch becomes so large that the it cannot hold its weight so collapses.
6. The remaining feature is called a stack which is an isolated column of rock.
7. The stack will eventually collapse to form a stump will be often submerged in the
water.
Longshore Drift:
• Longshore drift is the process of transportation which moves sand along the coast
• Waves approach the sand at angle which is controlled by the prevailing wind (most common
wind direction)
• The swash carries pebbles up the beach and an angle and backwash sends sediment down
the beach at a right angle.
• This results in a zig-zag movement.
,There are two types of beach which are swash aligned and drift aligned.
In swash aligned beaches the waves approach at 90 degrees so there is not longshore drift.
In drift aligned beaches the process of longshore drift will occur.
A spit is a long, narrow finer of sand jutting out from the land.
Formation of a spit:
1. When there is a change is direction of a coast, longshore drift cannot go around the
bend. It loses energy so therefore deposits material.
2. This process repeats and more sediment is dropped.
3. As the sediment builds up it will form a small land which will go to sea. This creates a
spit.
4. It will continue to grow out but strong winds and change in direction of wind will cause
to spit to curve on its tip.
5. The spit is connected to the land but cannot go to the side of the land as the river has
a strong current.
6. Behind the spit calm water develops creating a salt marsh.
Bars
Similar to the development of the spit, longshore drift may cause the spit to go right across the bay
and connecting to headlands trapping a lagoon behind it. This is called a coastal bar.
A bar is formed by a spit growing across a bay of two headlands.
River Landscapes and Processes
Drainage Basin – A drainage basin is an area of land which drains into a river and its tributaries. As the
rain falls, the water will slowly make its way to the main river. This can occur through various ways
within the hydrological cycle.
Watershed – This is the boundary between a drainage basin and the next drainage basin. This is usually
high land such as hills or ridges. Therefore, rain can fall on one side of a hill and drain into a completely
different river to rain on the other side of a hill.
Tributary – This is a smaller stream or river that joins a larger stream or river.
Source – This is the starting point of a stream or river. Often these are springs or lakes found in
mountainous areas where rainfall totals are higher.
Confluence – This is the point at which two streams or rivers meet.
Mouth – This is the point at which a river leaves its drainage basin and flows into the sea. This is also
known as an estuary.
Interception – When part of rainfall is intercepted by Earth’s surface and subsequently evaporated.
Trees, branches, houses: slow down water moving into river.
, Infiltration – The movement of water into the soil from the surface.
Throughflow – Moving of water horizontally beneath land surface until water is saturated. Quite quick
process. If saturated, surface run off occurs.
Percolation – Movement of water past the soil going deep into groundwater and flow into rocks. Slow
process.
Groundwater Flow (Base Flow) – Deeper movement of water through underlying permeable rock
below water table. Very slow movement of water.
Surface Run Off – Water that does not infiltrate will move across the ground as surface run off. This
often happens in urban areas where water hits tarmac. This is a rapid flow of water. Increased by
urbanisation and flooding.
River (Channel) Flow – Water flowing along the river, finally to the sea or another lake or river. Fastest
flow of water in the drainage basin.
Factors impacting rate of infiltration:
• The amount saturation level of the ground. If infiltration capacity of the soil has been reached,
then no infiltration will occur. This will mean the rate will be slow.
• If the gradient of the ground is steep, then infiltration will occur more slowly as the water will
be more likely to move downslope through surface run off.
• If the rock is permeable, this will allow for more infiltration. Whereas if the rock is
impermeable, less infiltration will occur as the soil will be able to hold less moisture and this
will slow the rate of infiltration.
• If there is vegetation in the area, this will break up the soil and allow more infiltration.
Freeze Thaw Weathering:
• Water gets into cracks on the river bank.
• When temperature drops below 0 degrees, water freezes and expands by 9%.
• This puts pressure on the rack and may break it apart.
• This is most common in upland areas in the river’s upper course.
Acid Rain:
• Rainwater contains weak acids.
• When this rain falls on rock such as chalk and limestone it will weaken and break down by
dissolving the rock.
Trees root:
• Seeds fall into cracks.
• When water is present, plants force out and grow.
• Over time, this breaks up rocks or cliff faces.
• Animals, such as burrowing rabbits also do the same.
Factors impacting rate of weathering:
• Hardness of rocks.
• Number of cracks in the rocks.
• Available water.
