Geography coastal landscapes

Causality

The relationship between cause and effect

Linked with important idea of power

Linking processes to landforms & landscapes

Equilibrium

A state in which forces or influences are balanced

Dynamic equilibrium

The system responds to disturbances but is overall still in equilibrium

Feedback

The process by which the coastal system responds to changing inputs and outputs

Interdependence

The relationship between human activity and coastal landscape systems

Mitigation

Action to reduce/decrease damage before it has happened

Related to coastal management

Adaptation

Action to change to accommodate damage after it has already happened

Related to shoreline plan

Risk

The potential to cause damage

In the context of the extreme weather events associated with anthropogenic climate change on coastal processes and landforms

Resilience

The ability to adapt/recover from adverse events

Related to coastal management in the context of people living in coastal areas

Systems

A group of parts that work together

An example of a system is the cliff sub-system

Thresholds

A factor that complicates the self-regulation of the coastal system- when crossed, it sets irreversible changes in motion

Dynamic open system

A system that has inputs & outputs that is constantly changing

In a state of dynamic equilibrium

Coastal system- inputs

• Sediment supply

• Tides

• Wind

• Beach nourishment

Coastal system- stores/transfers

• Longshore drift

• Transportation methods

• Erosion all compounds

• Depositional components

Coastal system- outputs

• Sediment removed by LSD

• Accumulation of sediment above the tidal limit

• Dissipation of wave energy

• Undersea sinks

Cliff sub-system

The subsystem above the high-tide level (relating to the shoreline)

Inputs of subaerial processes/wind erosion

Transfers of mass movement

Output of sediment at the base of the cliff which is either deposited or is transported by marine processes

Beach sub-system

The subsystem on the shore face

Has an input of sediment from LDS, the cliff and off shore

Transfer of longshore drift

An output of LSD and destructive waves carrying sediment offshore

Process response method

Used when discussing coastal systems

States that the morphology of any coastal landform is a product of the processes operating in the system

Balanced sediment budget equation

Volume of sediment in = volume of sediment store + volume of sediment out

Littoral cells

Units of coastal management where the dominant processes influencing the sediment budget are uniform within a stretch of coastline

Key features of sediment/littoral cells

• Discreet and function separately from each other

• Geographically bounded by significant changes in the coastline

• Sediment is sources, transferred and stored

• Over time sub-sinks will erode, and the sediment will re-enter the cell’s system

• The amount of sediment available to the sediment cell is called the sediment budget

Sediment cells in England and Wales

11 large cells, which are split up into many smaller sub-cells

South Downs sediment cell- statistics

• Drift/transport/flood direction west to east

• 5000m3 gravel and sand lost round beach head

• 8km out of 22km of cliff are protected

• Ouse and Cuckmere rivers provide 5000m3 of sediment to the east

• Adur & Arun rivers provide 2800m3of fluvial sediments to the west

• Wave cut platform erosion provides 400m3 of sediment

• Dredging causes 32000m3 of loss in Shorham Harbour, and 5000m3 of loss in Brighton Marina

South Downs sediment cell- information

• Occupies sub-cell 4D along the Sussex coast of England

• Between the cliff headlands of Selsey Bill and Beachy Head

• Split in half to the east and west of Brighton Marina, which forms two further sub-cells

• Heavily defences beaches

• Pebble and fossil beaches with sand exposed at low tide