1. Systems In Physcical Geography Flashcards
What is the coastal system?
A set of interrelated events of components working together
Consists of inputs, outputs, stores with flows, and transfers between them
What makes the coast an open system?
It has inputs, stores/components, flows/transfers and outputs of energy and matter which can cross the boundary of the system to the surrounding environment
What is the result of the combination of all the factors in an open system?
Distinctive landscapes
Made up of erosional and depositional landforms
Reflect human activity
Define dynamic.
Constantly changing
What is dynamic equilibrium?
Balance between inputs and outputs
If changes do occur, feedbacks will allow for correction
Give examples of what could upset the balance of dynamic equilibrium?
Mass movement (landslides)
Storms
Weathering
Human activity
What is positive feedback?
Progressively greater change from the original condition of the system
What is negative feedback?
The system is returned to its original condition
What are the inputs in a coastal system?
Energy (waves, wind, tides, sea currents)
Sediment
Geology of coastline
Sea level change
What converts inputs into the components that make up the coastal system?
Erosional processes Depositional processes (wind and water transport)
What are the two main components in a coastal system?
Erosional landforms and landscapes
Depositional landforms and landscapes
What are the main outputs in a coastal system?
Dissipation in wave energy
Accumulation of sediment above the tidal limit
Sediment removed beyond local sediment cells
Give an example of a negative feedback system.
Storm results in an increase in weathering and mass movement
Erosion of the slope becomes tester than transportation power of the waves
A scree slope is formed at the base of the cliff
The slope acts to protect the cliff from further weathering and erosion
Give an example of a positive feedback system.
Deposition occurs to form a spit across a river estuary
Further river velocity reduction
Leads to an increase in spit head material accumulation
Velocity of the river is further reduced due to increased friction with the deposited sand
(Back to beginning)
What is a closed system?
One with inputs and outputs of energy but not matter
Eg the earth, energy flows in from the sun but matter remains within the boundaries of the atmosphere
What is an isolated system?
One that has no inputs or outputs of either energy or matter
What is a feedback mechanism?
A process that uses the conduction of one component to regulate the other
(change in one part of the system leads to change in another part)
Give an example of dynamic equilibrium.
Constructive waves build up a beach, making it steeper
This encourages waves to plunge to become more destructive
The destructive waves remove material which is redistributed to the sea
This reduces the angle of the beach which encourages more constructive waves
(Back to beginning)
What is the backshore?
Area between the high water mark and the landward limit of marine activity
Changes usually only take place here during storms
What is the foreshore?
Area between the high water mark and the low water mark
Location of most marine processes
What is the inshore?
Area between the low water mark and the point where waves cease to have any influence in the land beneath them
What is the offshore?
Area beyond the point where waves cease to impact the land beneath
Activity is limited to deposition of sediments
What is the nearshore?
Area extending seaward from the high water mark to where waves begin to break
Comprised of the swash zone, surf zone and breaker zone
Describe the three zones of the nearshore.
Swash zone- area where a turbulent layer of water washes up the beach following the breaking of a wave
Surf zone- area between the point where waves break, forming a bubbly surface, and where waves move up the beach as swash
Breaker zone- area where waves approaching the coastline begin to break, around 5 to 10 m water depth
