Definitions Flashcards
Abrasion
A form of erosion where loose sediment and material ‘sandpaper’s walls and floors of a cliff or river
Attrition
Rocks bang against each other, chipping away to become smaller and rounder
Backshore
Upper beach closest to the land, including any cliffs or sand dunes
Beach nourishment
Addition of sand and sediment to an eroding beach by humans
Biological weathering
Rocks are broken apart by vegetation and roots, or chemical reactions from animal faeces erodes the rock face
Concordant coast
A coastline where bands of alternate geology run parallel to the coast
Corrasion
A form of mechanical erosion where material and sediment in the sea is flung at cliff-faces by waves
Chemical weathering
The weak acid in rainwater dissolves chemical compounds in rocks
Discordant coast
A coastline where bands of alternate geology run perpendicular to the shore
Drainage basin
The area of land drained by a river and its tributaries
Dredging
Removing rubbish and sediment from the bottom of a river
Embankments
Banks of a river are built up in brick or concrete to increase the channel capacity
Estuary
The point where the river meets the ocean, often muddy or silty.
Sometimes estuaries become exposed at low tide
Fetch
The length of water over which the wind has travelled
Floodplain
The low lying and wide floor of a river valley. Found in the lower course and tend to act as overspill for when the river channel is full
Floodplain zoning
Controlling where houses and buildings are built relative to the river to reduce the risk of flooding
Freeze thaw
A form of physical weathering where water freezes in the cracks of a rock, expands and enlarges the crack
Geology
The physical structure and arrangement of a rock
Groyne
A form of hard engineering that encourage the trapping of sediment to reduce erosion caused by longshore drift
Hard management
The use of concrete structures to reduce or halt the recession of a coastline
Highland
An area of land that is at a high elevation and tends to have a larger relief
Hydraulic action
Pressure of compressed air forced into cracks in a rock face causes the rock to weaken and break apart
Igneous rock
Formed from volcanic activity, often cooled magma on the Earth’s surface
Impermeable
A rock that does not allow water to pass through it
Levee
The banks of a river
Longshore drift
The transportation of sediment along a beach, determined by the direction of the prevailing wind
Lowlands
An area of land that has a small relief, so tends to be flat and at low elevation
Mass movement
When there is a large downhill movement of material usually from a cliff face, where the rock is soft due to erosion and movement is caused by gravity
Mechanical weathering
Breakdown of rocks due to forces, not chemical reactions
Metamorphic rock
Rock formed under intense pressure and heat, often close to tectonic plate boundaries
Permeable
A rock that allows water to pass through it
Relief
The difference in the height of land for a particular region
Rock armour
Large rocks used as barricades to reduce marine erosion at the base of cliffs
Saltation
A form of transportation where smaller sediment bounces along the sea bed
Salt marsh
In sheltered bays or behind spits, salts and minerals will build up. Vegetation may establish, further stabilising the marsh
Sand dune
A depositional landform, where sand and sediment build up around driftwood and accumulate over time
Sea wall
A hard management coastal defence, where a concrete wall is built parallel to the seafront to redirect the energy of waves away
Sedimentary rock
Rock that has formed as sediment and rocks become cemented and compressed together over thousands of years
Soft management
The use of natural materials and environmentally sustainable approaches to reduce coastal recession
Solution
Acidic water dissolves chemicals from a rock face into the water
Storm hydrograph
A graph to show the variation of river discharge over a short period of time
Suspension
Small rocks that are light enough to float are carried in the water
Spit
A long depositional landform, formed from sand and shingle
Thalweg
The path of fastest water flow in a river
Traction
Large rocks and boulders are rolled along the bed of the river or sea
