COASTAL LANDSCAPES
How can coastal landscapes be viewed as systems?
The components of coastal landscape systems including energy flows
Coast= open system
Inputs: kinetic energy (waves&wind), thermal energy (sun), potential energy
(material on slopes) & from weathering, mass movement, tides, sea currents,
erosion & deposition
Outputs: dispensation of wave energy, accumulation of sediment above tidal limit,
sediment removed beyond local sediment cells
Throughputs: stores (beach sediment) & flows (movement of sediment along beach
via LSD)
Components: erosional/ depositional landforms
Inputs = outputs
Equilibrium
//
Coasts dynamic & changing in state of dynamic equilibrium
Positive feedback loops= change escalates
Negative feedback loops=system returned to normal functioning
Sediment cells
Sediment cells=stretch of coastline within which the movement of sediment, sand & shingle
is largely self-contained
e.g. Land’s End - River Severn cell
,Coastal landscapes are influenced by a range of physical factors
Factors:
Wind:
- Created by diff in air pressure
- Source of energy for erosion & deposition
Waves:
Wave formation:
Height: diff between the crest (highest part) & trough (lowest part.)
Length: distance between crests
Wave period: times between crests
Frequency: how many crests pass certain point in certain period of time
- Formed by frictional drag of wind over ocean surface
- Higher wind speed & longer fetch=larger&more powerful waves
- Many coastlines have prevailing wind direction
Wave development & breaking:
Wave enters shallow water
Friction w/ sea bed increases
Wave slows as it drags along bottom
Wave length decreases & successive waves start to bunch up
Wave increases in height
Wave plunges/ breaks onto shore
, Constructive and destructive waves
Constructive:
- Low
- Long length (up to 100m)
- Low frequency (6-8 per min)
- Gentle spill onto shore
- Swash>backwash
How can coastal landscapes be viewed as systems?
The components of coastal landscape systems including energy flows
Coast= open system
Inputs: kinetic energy (waves&wind), thermal energy (sun), potential energy
(material on slopes) & from weathering, mass movement, tides, sea currents,
erosion & deposition
Outputs: dispensation of wave energy, accumulation of sediment above tidal limit,
sediment removed beyond local sediment cells
Throughputs: stores (beach sediment) & flows (movement of sediment along beach
via LSD)
Components: erosional/ depositional landforms
Inputs = outputs
Equilibrium
//
Coasts dynamic & changing in state of dynamic equilibrium
Positive feedback loops= change escalates
Negative feedback loops=system returned to normal functioning
Sediment cells
Sediment cells=stretch of coastline within which the movement of sediment, sand & shingle
is largely self-contained
e.g. Land’s End - River Severn cell
,Coastal landscapes are influenced by a range of physical factors
Factors:
Wind:
- Created by diff in air pressure
- Source of energy for erosion & deposition
Waves:
Wave formation:
Height: diff between the crest (highest part) & trough (lowest part.)
Length: distance between crests
Wave period: times between crests
Frequency: how many crests pass certain point in certain period of time
- Formed by frictional drag of wind over ocean surface
- Higher wind speed & longer fetch=larger&more powerful waves
- Many coastlines have prevailing wind direction
Wave development & breaking:
Wave enters shallow water
Friction w/ sea bed increases
Wave slows as it drags along bottom
Wave length decreases & successive waves start to bunch up
Wave increases in height
Wave plunges/ breaks onto shore
, Constructive and destructive waves
Constructive:
- Low
- Long length (up to 100m)
- Low frequency (6-8 per min)
- Gentle spill onto shore
- Swash>backwash
