Coasts As A System

Question 1

What are the inputs of coasts as a system?

Answer 1

1. Energy from the wind
2. Waves and tides
3. Sediment from weathering and erosion processes

Question 2

What are the stores in a coastal system ?

Answer 2

Sediment deposited in Land forms

E.g beaches

Question 3

What are the transfers in a coastal system?

Answer 3

Processes of erosion

Processes of transportation that can move Sediment around the system

Question 4

What are the outputs in a coastal system

Answer 4

Sediment is removed by long shore drift

Sediments are deposited as landforms such as dunes

Question 5

Define the coast as a system

Answer 5

The coast is an open system. Energy and Sediment can move from the boundary of the system into the environment around it.

Question 6

What is the sediment budget?

Answer 6

The balance between the input, store and outputs of sediment.

Question 7

What does anthropogenic mean?

Answer 7

Activity originating from humans

Question 8

Natural inputs of coastal sediment budget

Answer 8

Sediment from anything below:

Coastal stores ( marshes/dunes )
Cliffs
Rivers
Offshore

Question 9

Natural outputs of the coastal sediment budget

Answer 9

Sediment deposited in any of the following:

Coastal stores ( marshes/dunes )
Offshore during storms
Estuarine sedimentation

Question 10

Process that transfers sediment in the coastal sediment budget

Answer 10

Long shore drift ( transfers in and out of the budget )

Question 11

What are the anthropogenic inputs of the coastal sediment budget ?

Answer 11

Beach nourishment - humans depositing sand or other sediment into beaches from other sources - helps prevent erosion

Dune building - the process of building artificial sand dunes to provide coastal erosion defences

Question 12

What are the anthropogenic outputs of the coastal sediment budget?

Answer 12

Land claim -A land claim is a legal declaration of desired control over areas of property, including bodies of water

Dredging - Humans removing sediment from the seabed for industrial use

Beach mining - The extraction of sand from beaches for industrial use for things like glass and concrete

Question 13

If something was out of balance in the sediment budget what would be the impact?

Answer 13

It could increase erosion further along the coastline

Question 14

Describe the sediment budget when input sediment = output sediment

Answer 14

The sediment budget is in a steady-state equilibrium

Question 15

What is a sediment cell?

Answer 15

A sediment cell is a stretch of coastline where the sediment budget is self contained. It is also know as a littoral cell

Question 16

There are 11 major sediment cells for England and Wales.

The sediment cells can be described as an open system. Why is this ?

Answer 16

Because Sediment can be lost from the cells which makes it an open system

Question 17

Coasts are constantly changing due to variations in the energy conditions, such as storms.

When is a coast in equilibrium?

Answer 17

When both the inputs and the outputs of the system are equal

Question 18

Describe steady state equilibrium

Answer 18

When changes in energy and resulting change in coastlines do not vary much from the long-term average conditions

For example when the beach profile adjusts in summer and winter due to the wave energy changes but the average gradient stays the same

Question 19

Describe Metastable equilibrium

Answer 19

The coastal zone changes from one state of equilibrium to another due to an event causing a change in conditions

For example Sediment removed due to dredging changes the beach profile of it disappears. There is a new equilibrium with a reduced beach

Question 20

Describe dynamic equilibrium

Answer 20

The state of equilibrium changes over a longer timescale than metastable equilibrium

For example climate change. Causing rising sea levels allows new areas of land to be influenced by wave attack, resulting in a change in cliff profile

Question 21

What is feedback?

Answer 21

Feedback occurs as a result of a change in the coastal system, helping the system adjust

Question 22

What is positive feedback?

Answer 22

Increases the initial change that occurred

Question 23

What is negative feedback?

Answer 23

Reduces the effect of the change, helping the coast return to its original condition