Coasts as Natural Systems

Question 1

What type of system is a coastal environment

Answer 1

Open system

Question 2

inputs in coastal environments

Answer 2

Energy from waves, wind, tides and sea currents
Sediment
Geology of coastline
Sea level change

Question 3

Stores in the coastal environment from erosion processes

Answer 3

Erosional landforms and landscapes

Question 4

What kind of environment is a coast

Answer 4

Dynamic environment where land meets sea

Question 5

Stores in a coastal environment from wind and water transport

Answer 5

Depositional landforms and landscapes

Question 6

What outputs are there in a coastal environment from wind and water transport

Answer 6

Dissipation of wave energy
Accumulation of sediment above tidal limit
Sediment removed beyond local sediment cells

Question 7

What is an example of negative feedback in the coastal system

Answer 7

A beach is eroded, the cliffs behind it are exposed to wave attach. Sediment eroded from the cliffs is deposited on the beach , causing it to grow in size again. The negative feedback restores the balance of the system

Question 8

What is an example of positive feedback in the coastal system

Answer 8

As a beach starts to form it slows down waves, which can cause more sediment to be deposited, increasing the size of the beach. The new equilibrium is reached when long term growth of the beach stops

Question 9

Why is the coastal system in a state of dynamic equilibrium

Answer 9

If one of the elements of the system changes, e.g. there is increased deposition on a beach but there is no corresponding change in the amount of sediment removed from the beach, then the beach features may change and The equilibrium is upset

Question 10

What does using a systems approach help to explain

Answer 10

Variations and changes that occur along a coastline
Helps to predict the possible consequences of natural processes or proposed human interventions, helps us plan for positive or negative impacts

Question 11

How many sediment cells are there in England and Wales

Answer 11

11

Question 12

What type of systems are sediment cells

Answer 12

Closed sediment systems

Question 13

What happens if inputs exceed outputs

Answer 13

Then the beach will extend in height, length and/ or width = positive sediment budget

Question 14

What happens if outputs exceed inputs

Answer 14

The beach with become smaller over time = negative sediment budget

Question 15

What percentage of the world’s population live on coastal plains

Answer 15

Over 50% of population living within 150km of the sea

Question 16

What is a sediment cell

Answer 16

A distinct area of coastline separated from other areas by well defined boundaries, e.g. headlands and stretches of deep water

Question 17

What are the 4 different zones of a coastline

Answer 17

Backshore
Foreshore
Offshore
Nearshore

Question 18

What is backshore

Answer 18

Area between the high water mark and the landward limit of marine activity. Changes normally take place here only during storm activity

Question 19

What is foreshore

Answer 19

The area lying between the high water mark and the low water mark. Most important zone for marine processes in times that are not influenced by storm activity

Question 20

What is offshore

Answer 20

Area beyond the point where waves cease to impact upon the seabed and in which activity is limited to deposition

Question 21

What is nearshore

Answer 21

Area extending seaward form the high water mark to the area where waves begin to break.

Question 22

What 3 zones are there in the nearshore zone

Answer 22

Swash zone
Surf zone
Breaker zone

Question 23

What is the swash zone

Answer 23

Area where a turbulent layer of water washes up the beach following the breaking of a wave

Question 24

What is the surf zone

Answer 24

Area between the point where waves break, forming a foamy, bubbly surface

Question 25

What is the breaker zone

Answer 25

Area where waves approaching the coastline begin break usually where the water depth is 5 to 10m

Question 26

Why might sediment cells lose sediment to outputs beyond the system even though it’s a closed system

Answer 26

If wave energy is very high or currents very strong, then sediment may be transferred to neighbouring cells, be lost to deeper sea areas offshore or be transferred to stores beyond the active coastal zone e.g. upper beaches