Sediment Cells Flashcards
Define Sediment Cell
A sediment cell is a stretch of coastline which is littorally divided, usually bordered by two prominent headlands, where the movement of sediment tends to be contained
How many sediment cells are there in the UK?
11
What is each sediment cell divided into?
Each major sediment cell is divided into a number of sub-cells
Describe Sediment Cell
A sediment cell is a closed system usually bounded by headlands or a change in longshore drift
Within a sediment cell, there is erosion, transportation and deposition of sediment within a long-term cycle
The only inputs come from erosion from the sea bed or land
There is little or no movement between cells
Human activity such as beach management can interrupt the natural system, creating Imbalance within the cell, leaving some areas at risk of erosion
Define Sediment Sources
- where Sediment inside the cell comes from
- a sediment source is an input
- e.g. Currents bring in materials from the sea bed
- e.g. Rivers ring Sediment downstream
Define Sediment Transfers
This is how the sediment is moved around inside the sediment cell
E.g. Tides, currents, wind, waves/longshore drift
Define Sediment Sinks
- this is where the sediment inside the cell is deposited
- this means that it is a store/component
E.g. Beaches, bays, saltmarshes (landforms of deposition)
What is the Sediment Budget
Describes the balance between the sediment being added to part of the sediment cell and the sediment being taken away from the sediment cell
What is the Sediment Surplus?
If more sediment is added to the beach, it is a surplus
So the coast is extended and the beach gets bigger
What is the Sediment Deficit?
This is when Sediment is taken away from the beach , so it is a deficit
So the coast retreats, and the beach retreats
What does each sediment cell have?
Each sediment cell sub-cell has a shoreline management plan
In this way the coast can be managed in a practical and sustainable way.
4 types:
1. Hold the Line
2. Advance the Line
3. Managed Retreat
4. Do Nothing
What shoreline management plan is occurring in Sheringham and West-East Runton? And the consequences of this?
Sheringham = Hold the Line
West-East Runton = Managed Retreat
This will cause the promontory effect as Sheringham Is protected and West Runton is not.
So Sheringham becomes an artificial headland and over time, may have to adopt managed Retreat to return the natural state back to normal
Example of Sediment Cell
The Wash
Covers: Suffolk - Norfolk - Bit of London
