P1 Section C (Coastal Systems and Landscapes) Flashcards
What is a System
A system is a set of interrupted components working together towards some kind of process.
Closed System
a closed system is a system that transfers energy, but not matter, across its boundary to the surroundings like our planet
Open system
an open system it a system that transfers both matter and energy across its boundary to the surroundings like most ecosystems
What is an Input
An input is an addition of matter, energy or information to a system
What is an output
an output is the movement of matter, energy or information out of a system
What is a store
a store is a place where matter, energy or information is stored in a system.
what is a sediment cell (area, transfers)
a sediment cell is an area of shoreline that encompass the intertidal and nearshore movement of sediment, it basically consists of zones of erosion (e.g. shoreline bluffs), transport (e.g. beaches), and deposition (e.g. spit) and is a closed system
what is dynamic equilibrium in sediment cells
dynamic equilibrium in sediment cells refers to the maintenance of balance in sediment, with both outputs and inputs counteracting change to keep balance.
what happens if sediment budget decreases?
when sediment budget decreases, waves will move sediment and cause erosion
what happens if sediment budget increases
when sediment budget increases, deposition will occur as a way to remove excess material.
what type of systems are sediment cells?
sediment cells are usually closed systems as they do not transfer sediment to one another
what are examples of coastal inputs
examples of coastal inputs include waves, tides, sun, pollution and wind speed.
what are examples of coastal outputs
examples of coastal outputs include evaporation, riptides and currents.
what are examples of coastal stores
examples of coastal stores include beaches, sand dunes, caves and arch’s
what are transfers
transfers are the processes that link inputs stores and outputs
examples of transfers
examples of transfers include erosion (abrasion and hydraulic action), transportation (solution and traction) and deposition (flocculation and gravity settling)
what is positive feedback and example in sand dunes
positive feedback is when a system is taken away from dynamic equilibrium such as people walking over sand dunes will damage plants, which makes the dunes more erosive as less stable and they become eroded even further.
what is negative feedback and example
negative feedback is lessening a change that has occurred in the system such as if a cliff is eroded, the material forms a wave cut platform below and prevents further erosion of the cliff.
sources of sediment at the coast
sources of sediment at the coat include rivers (fluvial flow), wind blowing sand (aeolian flow), cliff erosion and longshore drift.
littoral zone
the littoral zone is the area between the cliffs or dunes of a coast and the offshore area that is beyond the influence of waves and so is covered by the sea at some times.
what factors change the littoral zone?
factors that change the littoral zone can be short term like storms and long term factors like changes in sea level.
how do waves form (frictional, small,
waves form by wind passing over water creating frictional drag causing small ripples which produces a orbital movement of particles so waves move horizontally in shallower waters. more horizontally moving of waves causes them to gain height, but when height increases, wavelength and wave velocity decrease causing the wave to break and surge up the beach.
factors affecting the energy of waves
factors affecting the energy of waves include strength of wind, duration of wind (long time means more energy build up) and fetch (fetch is the distance the wind blows over)
characteristics of a constructive wave
characteristics of a constructive wave include formed by weathers in the open ocean, have long wavelength, low frequency, low wave height, strong swash and weak backwash and constructive waves occur on gently sloping coasts
characteristics of destructive wave
characteristics of destructive waves include happen by storms close to the coast, destructive waves have short wavelength, long frequency, higher waveheight and they have weak swash and strong backwash and they occur on steep sided coasts.
what is tidal energy at the coast
tidal energy at the coast is energy caused by gravity of the moon pulling water and causes a high tide and if the earths surface is far from the moon then there is low tide.
what are spring tides
spring tides are times of the year when the gravitational pull from the moon is strongest and gives highest tides
what are neap tides
neap tides are the time of the year when the gravitational pull of the moon is weakest and the tides are at the lowest.
When do longshore currents occur
longshore currents occur when a wave releases a burst of energy parallel to the coastline
how is longshore current energy determined?
longshore current energy is determined by height of wave break and angle of beach slope. So if wave breaks at a tall height at a steep beach angle, then longshore current energy and velocity increases
characteristics of a high energy coastline
characteristics of a high energy coastline include destructive waves, rocky headlands and landforms and faster rate of erosion than deposition.
characteristics of a low energy coastline
low energy coastlines have constructive waves, sandy areas and there are depositional landforms like bars and spits and rate of deposition exceeds rate of erosion
when does wave refraction occur
wave refraction occurs when the coast is discordant so waves move faster and slower due to more and less friction and waves refract away from the headland as they have low energy and diverge into bays
What is attrition
attrition is wave action causing rocks to hit against each other and become small and round
what is corrasion
corrasion is when rocks are picked up by waves and hurled at the cliffs
abrasion
abrasion is when sediment scrapes along the shoreline and worn down
hydraulic action
hydraulic action is when waves crash into a crack in cliff, high pressure causes air to expand and further crack the rocks
corrOsion
CorrOsion is when acidic water can erode alkaline rocks like limestone
What is wave quarrying
wave quarrying is when waves break against cliffs and erode it from shear force
What are factors affecting erosion
factors affecting erosion are waves (strength and velocity), size of littoral zone (can absorb energy), rock type (sedimentary rocks like sandstone are weaker) and rock faults (faults, cracks and joints can weaken rocks before erosion).
What is traction
traction is when large heavy sediment is rolled along the sea bed.
saltation
saltation is when small sediment bounces along the sea bed
What is suspension
suspension is when fine sediments are held up and carried by the flow of the water
What is solution
solution is when dissolved material is carried within the water
what is weathering
weathering is the breakdown of rocks over time leading to the transfer of the material into the littoral zone, where it becomes an input to sediment cells.
what is freeze thaw weathering
freeze thaw is a mechanical weathering is when water goes into cracks, freezes, expands and causes an increase of pressure which erode the rock
what is carbonation weathering
carbonation weathering is a chemical weathering when rain absorbs carbon dioxide from air which forms a weak carbonic acid that then reacts with calcium carbonate in rocks to make it easier to dissolve.
what is plant root weathering
plant root is biological weathering when roots grow into cracks, faults and joints which exerts pressure and eventually splits the rock
formation of wave-cut notch and platform
a wave-cut notch forms when hydraulic action and corrasion concentrates at the high-tide and creates a notch in the cliff which is weakened by sub-aerial weathering like plant roots and so eventually it collapses through mass movement leaving behind a platform, and this process repeats and creates a wave-cut platform.
What is a swash aligned coast
A swash aligned coast is when the wave travels straight to the beach and so there is limited longshore drift.
What is a drift aligned coast
A drift aligned coast is when waves approach at a significant angle so there is more longshore drift
how does a spit form
spits form when the coast changes angle and increases turbidity so more deposition happens by longshore drift and salt marshes will form behind the spit as it is sheltered.
what is a tombolo
a tombolo is a spit that connects to an island offshore.
what is a bar
a bar is when a spit joins two headlands and traps water and forms of a lagoon
halophytes
halophytes are plants that grow in saltwater
humus
humus is decomposed matter that is added to sediment naturally
stages of plant succession
stages of plant succession start with pioneer stage, where pioneer plants grow, the 2nd stage is establishment and then stabilisation until finally climatic climax, where in the UK large plants grow like oak trees.
What is plagio-climax (plant succession)
plagio-climax is when vegetation is artificially induced in pastures and farmland.
what happens to pH as distance from sea increases
as distance from sea increases, pH decreases as there is less alkaline sea water and also humus will decrease pH as organic materials adds acidity.
what is needed to start a sand dune
to start a sand dune a large inter-tidal zone and large sediment budget (so the prevailing winds can blow the sand towards the back of the beach) and strong onshore winds are necessary.
what is short-term sea level change caused by
Short-term sea level change is caused by high tides and low tides, wind strength and wind direction
reasons for increase in biodiversity further into the dunes
biodiversity increases further into the dunes as there is less environmental stressors (like shelter from wind), there is lower pH, less salinity, more humus (so rich, fertile soils) and also the dunes are more stabilised so lichens and various grasses grow.
what is eustatic change (sea level)
eustatic change is a change in global sea level, usually due to a change in the volume of water in the oceans.
what causes eustatic change?
eustatic change is typically caused by thermal expansion/contraction (when heat causes water particles to expand) or changes in glacial processes.
what is isostatic change (sea level)
isostatic change a localised change, of land level - when land rises or falls, relative to the sea level.
what causes isostatic rise in land level and therefore fall in sea level?
an isostatic rise in land level (causing fall in sea level) may be caused by post-glacial adjustment, tectonics and accretion (sediment cells experiencing more deposition so land builds up and sea level falls)
what causes isostatic fall in land level, therefore rise in sea level?
Isostatic fall in land level (making a rise in sea level) is caused by post-glacial adjustment, tectonics and subsidence (excessive amount of deposition causes land to sink).
emergent landforms
emergent landforms appear when sea level falls and land rises, they are features like arch’s, stacks and stumps that are preserved
When do submergent landforms appear
submergent landforms appear when land level sinks and sea level rises.
examples of submergent coastal landforms
examples of submergent coastal landforms are rias, fjords and dalmatian costs
what is a shoreline management plan? (SMP)
A shoreline management plan is a policy for managing a particular sediment cell.
hold the line (example of SMP)
hold the line is management by using defences to maintain the current position of the coast
What does managed retreat do (example of SMP
managed retreat allows the coast to advance inland and it buys time to build nature defences like salt marshes
What is advance the line (example of SMP)
advance the line is when defences are built to move the shoreline seawards mainly to protect a population centre or tourist amenity
What is integrated coastal zone management (ICZM)
integrated coastal zone management is a sustainable management of the coast within one strategy, taking into consideration stakeholders and the nearby population .
pro of SMP
a pro of SMP is that it reduces human intervention by allowing natural change of the coastline by working with nature
con of SMP
a con of SMP is that risks may not be correctly examined and incorrect precautions may be taken
pro of ICZM
a pro of ICZM is that it incorporates stakeholders and local organisations and also considers the full coastal process recognising one defence in this place may increase erosion in another
con of ICZM
a con ICZM is that local authorities can be overruled by a higher-governance level.
where is the maldives located (case study for sea level rise)
the maldives is located in the indian ocean, south west of sri lanka
how much of the land lie below 1 metre in maldives
80% of the land lies below 1 metre in maldives
how many airports and harbours does the maldives have
the maldives has 5 airports and 128 harbours, all near the coastlines
in 2007, how many people were evacuated from their homes and why and how many home were damaged in maldives
In 2007, more than 1600 people were evacuated from their homes as a result of numerous swells, the swells also damaged over 500 houses in maldives
how is the maldives threatened by the sea?
the maldives is threatened by the sea as increasing sea temperature will destroy reefs and the sea level rise is rising over the land
by how many mm does the sea level rise by in the maldives?
the maldives is experiencing a 3mm rise per year, so in 300 years, most of the island will be underwater
population of the maldives
population of the maldives is 360,000 people
how close are the 2 international airports to the coastline in Maldives
the 2 international airports are within 50 metres of the coastline in maldives
political issue of rising sea levels in the maldives
a political issue of rising sea levels in the maldives is that 300,000 maldivians could become environmental refugees, which would rise dependency ratio and increase the economic pressure on the workforce.
what is a social issue of rising sea levels in the maldives
a social issue of rising sea levels in the maldives is islanders infrastructure are in danger of being flooded or eroded - losing communal areas, areas of tradition and culture etc.
economic issue of rising sea levels in Maldives
an economic issue of rising sea levels in the Maldives is that tourism makes up nearly 30% of the Maldives GDP showing the government is over-reliant on one source of economy.
What is an environmental issue of rising sea level in Maldives
An environmental issue of rising sea levels in the Maldives is land will become infertile due to saltwater inundation and beaches will constantly be in need of replenishment as they are destroyed
What is the Sundarbans?
The sundarbans is a 10,000km^2 delta in Southwestern Bangladesh and East India
What is the Sundarbans topography
The Sundarbans topography is very flat and low-lying
What is the Sundarbans intersected by?
The Sundarbans is intersected by thousands of channels containing sandy or silty islands.
What are large areas of the Sundarbans protected by
Large areas of the Sundarbans are protected by a National Park or Forestry Reserve
How does the Sundarbans sediment store stay the same
The Sundarbans sediment store stays the same as material is deposited by rivers and eroded by the seas
How many people live in the Sundarbans
4 million people live in the Sundarbans
What are opportunities brought by natural resources in the Sundarbans
Opportunities brought by natural resources in the Sundarbans include flat and fertile land for crops like rice, a rich ecosystem providing fish, crabs and honey, and forests providing Nipa Palm leaves and timber for infrastructure and furniture.
What are the opportunities brought by mangroves in the Sundarbans
The opportunities brought by the mangroves in Sundarbans include natural flood barriers and protection from coastal erosion as roots bind soils together
What are the opportunities brought by development in the Sundarbans
Opportunities brought by development in the Sundarbans include tourism and dredging of channels to allow passage for cargo ships and power plants north of the region
What is mitigation
Mitigation is reducing the severity of hazards and other problems
What is adaptation
Adaptation is adjusting behaviour to fit the environment
What is resilience
Resilience is being able to cope with the challenges of the environment
How to people overcome the risks of the Sundarbans
People overcome the risks of the Sundarbans by mitigation, resilience and adaptation.
What are developmental and occupational risks of the Sundarbans
Developmental and occupational risks of the Sundarbans are a lack of fresh water, mangroves removed for population (which increases flooding), flooding leads to salinisation so crops can’t grow, lack of communication so no flood warnings and lack of employment and income.
Examples of adaptation in Sundarbans
Examples of mitigation in Sundarbans are USAID training 30,000 locals in sustainable fishing and farming, planting rice which is more salt-tolerant and building storage tanks for access to freshwater during coastal floods
Examples of resilience in Sundarbans
Examples of resilience in Sundarbans are the Livelihoods Fund planting 16 million man gives since 2011 and it is hoped these 16 million mangroves with capture 617,000 tonnes of carbon over 20 years and increase protection and provide resources
Examples of mitigation in Sundarbans
Examples of mitigation in Sundarbans are 3500km of embankments built to prevent floods and investing in multi-purpose buildings for schools and cyclone shelters
What is a disadvantage of the 3500km^2 of embankments in the Sundarbans
A disadvantage of the 3500km^2 embankments is that 800km of them are vulnerable to storms so will be eroded
What do coastal management projects aim to do for mitigation with mangroves in the Sundarbans
Coastal management projects in the Sundarbans aim to protect existing areas of mangroves and replant areas that have been removed in order to protect against flooding
What is a challenge of coastal management projects
A challenge of coastal management projects is that it is difficult to prevent illegal forest clearance
How much did 3500km embankments cost the Sundarbans
The 3500km of embankments in the Sundarbans coat £28 million
Where is Holderness
Holderness is on the East coast of Yorkshire, England.
How did the government use mitagation strategies to prevent erosion in Easington and Mappleton of Holderness.
The government used mitigation strategies such as £2 million worth of revetments in Easington and Mappleton to prevent erosion.
How did Skipsea Holiday Park suffer as a result of the Government’s investment elsewhere
Skipsea Holiday Park suffered as a results of the governments investment elsewhere as they needed to build their own Gabions as the government did not invest.
Why did the Government not invest in the coastal defence of Skipsea Holiday Park
The Government didn’t invest in the Skipsea Holiday Parks coastal defence as it is not considered to be beneficial the the economy, unlike Easington and Mappleton in Holderness.
How do Dalmatian coasts form
Dalmatian costa form by rising sea level invading low level land areas to make it appear there are islands from the coast
How do fjords form
Fjords form when melting glaciers bring rock down with them creating U-shaped valleys filled with melted glacial ice
How do rias form
Rias form by river valleys submerging by rising seal levels
Aeolian process
Aeolian process is anything caused by wind like aeolian deposition
How is coastal management sustainable in West Sussex
coastal management is sustainable in West Sussex as when groynes are broken, they’re recycled and the timber is used by local people such as for commercial kitchens and raised herb gardens
