1.A - how can coastal landscapes be viewed as a system?

Question 1

what is a coastline?

Answer 1

where the land and the sea meet

Question 2

what are the 5 inputs of a coastal system?

Answer 2

1. marine sediment deposited by waves
2. sunshine (thermal energy)
3. wave/wind (kinetic) energy
4. fluvial (river) sediment
5. weathered material from cliffs

Question 3

what are the 2 flows of a coastal system?

Answer 3

1. wave movement on and off the beach
2. wave movement along the beach (longshore drift)

Question 4

what is an input?

Answer 4

something added to the system

Question 5

what is a flow?

Answer 5

something inside the system

Question 6

what is a store?

Answer 6

something inside the system

Question 7

what is an output?

Answer 7

something that leaves the system

Question 8

what are the 3 stores of a coastal system?

Answer 8

1. the beach
2. sand dunes
3. offshore bars

Question 9

what are the 3 outputs of a coastal system?

Answer 9

1. sediment taken away by wind
2. evaporation of water
3. marine sediment eroded by waves

Question 10

what is meant by a system in equilibrium?

Answer 10

• when a system’s inputs and outputs are equal, a state of equilibrium exists within it.
• in a coastal landscape, this could happen when the rate at which sediment is being added to a beach equals the rate at which sediment is being removed from the beach
• the beach with therefore remain the same size.

Question 11

what is meant by negative feedback and when does it occur in a coastal system?

Answer 11

• when coastal equilibrium is disturbed, the system undergoes self-regulation and changes its form in order to restore the equilibrium (DYNAMIC EQUILIBRIUM)
• the system produces its own response to the disturbance, which is NEGATIVE FEEDBACK

Question 12

what is an open system?

Answer 12

• a type of system whose boundaries are open to both inputs and outputs of energy and matter
• energy fluxes (moves) across its boundaries

Question 13

what is a closed system?

Answer 13

• a system with inputs and outputs of energy, but without any movement of materials across system boundaries
• only energy can flow across its boundaries

Question 14

how is a coastline made?

Answer 14

• solar energy is the predominant input of energy when it comes to natural systems.
• this solar energy contributes to the uneven pattern of heating our planet which in turn creates an atmospheric circulation, and surface air movements or wind.
• wind energy can get converted into wave energy (both kinetic)
• the waves, in turn, can move sand from bars along the coast to deposit it on the beach.
• the wave energy may also move sediment along the littoral zone
• thermal energy from the sun can dry the sand out and this can be moved by the wind in aeolian processes.
• the coastline may also be subject to tectonic processes and hence geothermal energy as well as gravitational energy from the moon and sun, which leads to tides.

Question 15

why are coastal landscapes recognised as “open?”

Answer 15

• coastal landscapes are recognised as being an open system because the inputs and outputs can be transferred from neighbouring systems.
• for example rivers will bring in fluvial material (rocks and sediment eroded and transported by the river), and this material can be transferred in and out of the system

Question 16

how many sediment cells are there?

Answer 16

11 across England and Wales

Question 17

what is the definition of a sediment cell?

Answer 17

• a length of coastline and its associated nearshore area within which the movement of coarse sediment (sand and shingle) is largely SELF-CONTAINED.
• interruptions to the movement of sand and shingle within 1 cell should not affect beaches in neighbouring sediment cells.

Question 18

what are 3 key characteristics of sediment cells?

Answer 18

1. cells function separately from each other. they are geographically bounded by significant disruptions to the coastline (e.g. headlands/estuaries)
2. within the cell, sediment is SOURCED, TRANSFERRED and STORED. coarse sediment is not exchanged between cells but finer sediment in suspension is.
3. the amount of sediment available to the cell is the sediment budget. the cell produces depositional feature which are in equilibrium with the amount of sediment available.

Question 19

what is the sediment budget?

Answer 19

• the amount of sediment available to the cell is the sediment budget. the cell produces depositional feature which are in equilibrium with the amount of sediment available.
• if the budget is decreased then the waves will continue to move sediment, causing erosion in some areas.
• if the budget increases then more deposition is likely.