Coastal Systems And Landscapes Flashcards
Abrasion
A form of erosion where loose material ‘sandpaper’s’ the walls and floors of a river, cliff or glacier.
Back shore
The upper beach, closest to land
Beach morphology
The surface shape of the beach
Coastal recession
The retreat of a coastline due to erosion, sea level rise or submergence
Concordant coastline
A coastline where bands of alternate geology run parallel to the coast
Corrasion
A form of erosion when breaking waves fling material at a cliff face, physically knocking off material
Corrosion
The acid in sea water and some types of sea weed attacks particular rock minerals, causing erosion and weakening
Dalmatian coast
A concordant coastline with several river valleys running perpendicular to the coast. They become flooded to produce parallel long islands
DEFRA’s 1:1 cost benefit analysis
The evaluation of a coastal town’s economic value compared to the cost of the management required. Costs are tangible and intangible, could be money or visual impact
Discordant coastline
A coastline where alternate geology run perpendicular to the shore
Dynamic equilibrium
Where a natural system tries to achieve balance by making constant changes in response to a constantly changing system
Emergent coast
A coastline that is advancing relative to the sea level at the time
Eustatic
Global changes to sea level
Fetch
The distance the wave travels before it reaches the shoreline.
Fjord
Long narrow inlet deeper in the middle section than at the mouth, created when sea levels rise relative to the land, flooding coastal glacial valleys
Foreshore
The lower part of the beach covered twice a day at high tide, receives the most regular wave action
Freeze thaw
A fork of physical sub aerial weathering where water freezes in the cracks of a rock, expands and enlarges the crack, therefore weakens the rock
Geology
The structure and arrangement of a rock
Glacial erosion
The removal of loose material by glacier ice, involving plucking, abrasion, crushing and basal melt water
High energy environment
A coastline where wave action is predominantly large destructive waves, causing erosion
Hydraulic action
The pressure of compressed air forced into cracks in a rock face will cause the rock the weaken and break apart
Integrated coastal zone management (ICZM)
Large sections of coastline are managed with one integrated strategy and management occurred between different political boundaries
Impermeable
A rock that does not allow rainwater to pass through
Isostatic
A change in the height of the coastline relative to the sea
Littoral cell
A section of the coast, within which involves much sediment movement. A littoral cell is not a closed system
Longshore drift
The transportation of sediment along a beach. Determined by direction of prevailing wind
Low energy environment
A coastline where wave action is predominantly small contrastive waves, causing deposition
Beach accretion
Process of coastal sediment returning to visible portion of beach or foreshore
Mass movement
The falling or movement of rock
Nearshore
The area before the shore where wave steepness and breaks before they reach the shore and then reform before breaking on the beach. Extremes from low tide zone then out to sea
Permeable
A rock that allows rainwater to pass through it
Plant succession
Change to a plant community due to growing conditions adapting (e.g. salt marsh)
Ria
Narrow winding inlet which is deepest at the mouth, formed when sea levels rise causing coastal valleys to flood
Saltation
Smaller sediment bounces along the sea bed, being pushed by currents, as it’s too heavy to be picked up by flow of water
Sediment cell
Section of the coast bordered by prominent headlands. Within these sections, the movement of sediment of almost contained and the flows of sediment should act in dynamic equilibrium
Sediment budget
Use data of inputs, outputs, stores and transfers to asses the gains and losses of sediment within a cell
SMP
Identifies all of the activities, both natural and human, which occur within the coastline area of each cell and then recommends a combination of 4 actions for each stretch of that coastline
Hold the line
Coastal defences are maintained to protect a coastline from the impacts of rising sea levels and erosion, no new ones are built
Advance the line
New defences are built further into sea in an attempt to revise the stress on current defences and possibly extend the coastline
Managed retreat
Move people and allow coastal processes to occur
Do nothing
The area is no of any value, coastal processes are ignored
Sub aerial processes
The combination of mass movement and weathering thats affects coastal land above the sea
Submergent coast
A coast that is sinking relative to the sea level
Till
Deposits of angular rocks fragments in a finer medium
Wave quarrying
When the air is trapped and compressed against a cliff which causes rock fragments to break off the cliff over time
Hard engineering
Construction of physical structures to protect coasts
Soft engineering
The natural environment is used to help reduce coastal erosion, it uses sustainable ecological practice to restore shoreline stabilisation
