new sediment or energy entering the coastal system
e.g, energy from waves, wind, gravity or tectonics
sediment from erosion of cliffs or seabed
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what is a flow on the coast?
the movement of sediment or energy along the coast
e.g, mass movements,erosion, LSD, tides, currents, aeolian transportation(wind)
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What is a store on the coast?
Places where sediment is stored ( sand, shingle, pebbles)
e.g, beaches, sand dunes, spits
depositional land forms
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What is an output on the coast?
Sediment or energy leaving the system
e.g, sediment carried offshore, evaporation, loss of wave energy
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What is dynamic equilibrium?
When there is a balance between the inputs and outputs within a system
natural systems left undisturbed will often attain dynamic equilibrium// if one element changes, such as an increase in an input the equilibrium is upset- feedback
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What is positive feedback?
A series of events which amplifies or increases change
These loops excacerbate (make worse) the outputs and promote environmental instability
e.g, an increase in Co2
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What does a positive feedback cycle look like?
Starting point is different each time, as effects have been maintained-> A process occurs inflicting change-> A knock on change happens>A further process occurs
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Positive feedback on a coast?
High wave energy conditions develop->Sand dune system breached-> Binding vegetation stabalising the sediment is washed away->More sand dune is now unstable allowing further erosion of sediment
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What is negative feedback?
A series of events which nullifies (cancels out) the effects of a system, promoting environmental stability and dynamic equilibrium
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What does a negative feedback cycle look like?
The starting point is the same each time round, as effects have been nullified-> A process occurs inflicting change-> a knock on change happens->A further process occurs which cancels out and reverses the previous change
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Negative feedback on a coast?
Constructive waves move sediment up the beach during low energy conditions->Sediment accumulates and forms a beach with a steep profile->Conditions become higher energy with destructive waves dominating and sediment is removed-> original beach profile ret
Stretches of coastline usually bounded by major headlands or bays within which inputs and outputs are balanced
Boundaries are formed where there is a change in LSD direction
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What type of systems are sediment cells?
Closed systems
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Where are the sediment cells in the UK?
- St Abb's head
- Flambrough head
- River Thames
- The wash
-Sesley bill
- Portland Bill
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.......
- Solway firth
- great orme
- St davids head
- Lands end
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What is the sediment budget?
The balance between sediment being added and removed from a sediment cell
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What does the sediment budget entail?
Waves and tides can bring sediment from offshore locations and desposit it but they can also remove sediment from beaches and transport it
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What is a budget surplus?
If more sediment is added to the cell than is removed a net accretiation (net gain) of material occurs and the beach builds out seaward
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What is a budget deficit?
If more sediment is lost from the cell than is added
Management methods are employed in order to combat this
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How does the sediment cell system operate?
There are constant inputs, outputs, flows and stores operating//As some sediment is deposited in a location (sink)some is taken away (source) Nothing is permanent these are ever changing (dynamic)//
Some stores are long term such as, beaches or sand dune
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Other cards in this set
Card 2
Front
what is a flow on the coast?
Back
the movement of sediment or energy along the coast
e.g, mass movements,erosion, LSD, tides, currents, aeolian transportation(wind)
The coast can be seen as a system in order to help to understand the processes and interactions involved. In theory, the inputs, processes and outputs work. It's interesting things I know with diggy
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