1.1. How can coastal landscapes be viewed as systems?
1c. Coastal sediment is supplied from a variety of sources
Various sources of coastal sediment: Human
Terrestrial In order to achieve sediment equilibrium beach
nourishment is used as a human management
Sediment budget = the balance of the sediment volume entering and exiting a particular technique to restore this
section of the coast However, wind, waves and LSD movements can
Rivers are major sources of sediment input to the coastal sediment budget (90% of remove sediment from the beach
all sediment comes from there), especially steep gradient coastlines (fluvial By doing: amount of sediment gained – amount
deposition) – directly deposit sediment at coast of sediment lost = it can be determined if the
This sediment originates from erosion of inland areas by water, wind and ice & sub- sediment budget is in surplus, deficit or
aerial processes – weathering & mass movement equilibrium
Marine/wave erosion is a source of large amounts of sediment which contribute to
coastal sediment budgets
Such as cliff erosion (mass movement) - can increase due to rising sea levels,
contributes up to 70% of overall material supplied to beaches
Aeolian deposition also contributes largely to coastal sediment, sediment is blown
and travels large distances, deposited on the coast
LSD also supplies sediment from one coastal area by moving it along the coast to
adjacent areas
Offshore
Marine deposition – constructive waves, tides & currents bring sediment to the
shore from offshore locations & deposit it adding to sediment budget
Wind transports fine sediment e.g. from exposed sand bars/dunes to other locations
on the coast, as it has less energy than wave energy so cannot transport very large
particles
1c. Coastal sediment is supplied from a variety of sources
Various sources of coastal sediment: Human
Terrestrial In order to achieve sediment equilibrium beach
nourishment is used as a human management
Sediment budget = the balance of the sediment volume entering and exiting a particular technique to restore this
section of the coast However, wind, waves and LSD movements can
Rivers are major sources of sediment input to the coastal sediment budget (90% of remove sediment from the beach
all sediment comes from there), especially steep gradient coastlines (fluvial By doing: amount of sediment gained – amount
deposition) – directly deposit sediment at coast of sediment lost = it can be determined if the
This sediment originates from erosion of inland areas by water, wind and ice & sub- sediment budget is in surplus, deficit or
aerial processes – weathering & mass movement equilibrium
Marine/wave erosion is a source of large amounts of sediment which contribute to
coastal sediment budgets
Such as cliff erosion (mass movement) - can increase due to rising sea levels,
contributes up to 70% of overall material supplied to beaches
Aeolian deposition also contributes largely to coastal sediment, sediment is blown
and travels large distances, deposited on the coast
LSD also supplies sediment from one coastal area by moving it along the coast to
adjacent areas
Offshore
Marine deposition – constructive waves, tides & currents bring sediment to the
shore from offshore locations & deposit it adding to sediment budget
Wind transports fine sediment e.g. from exposed sand bars/dunes to other locations
on the coast, as it has less energy than wave energy so cannot transport very large
particles
