Operation Of The Coast As A System Flashcards
Inputs of a coastal system
Energy from wind waves and tides
Sediment from weathering and erosion processes
Outputs of a coastal system
Sediment removed by longshore drift and sediments deposited as landforms eg dunes
Transfers of a coastal system
Processes of erosion and transportation that can move sediment around the system
Stores of a coastal system
Sediment deposited in landforms
Is the coast open or closed system and why?
Open system. Energy and sediment can move from the boundaries to the environment around it
How doe the coastal sediment budget change?
Through natural and anthropogenic causes.
Human- land claim, dredging, beach mining
Natural- beach feeding, dune building, from cliffs and rivers
When is the sediment budget balanced?
When input = output (equilibrium)
How many sediment cells are there for England and Wales
11 major cells divided into smaller sub cells
Is a sediment cell an open or closed system and why?
Sediment cell is an open system as sediment can be lost and gained
What is a sediment cell?
A sediment cell is a stretch of coast line where sediment budget is self contained. Aka littoral cell
Where does sediment input come from?
90% from rivers. Up to 5% from coastal erosion
What are the 3 types of coastal equilibrium?
Steady state equilibrium
Metastable equilibrium
Dynamic equilibrium
Definition and example of steady state equilibrium
Changes in energy and the resulting change in coastlines do not vary much from the long term average conditions.
Eg beach profile adjusts in summer and winter as wave energy changes but average gradient stays the same
Definition and example of metastable equilibrium
The coastal zone changes from one state of equilibrium to another due to an event causing a change in conditions.
Eg sediment removal, due to dredging changes the beach profile or it disappears, there is a new equilibrium with a reduced beach.
Definition and example of dynamic equilibrium
The state of equilibrium changes over a longer time scale than metastable equilibrium
Climate change causing rising sea level allows new areas of land to be influenced by wave attack, resulting in a change in cliff profile
