Coasts

Question 1

What is a system?

Answer 1

A system is a set of interrelated components working together towards some kind of process

Question 2

How is the coastline a system?

Answer 2

The coastline is an open system. It has a range of inputs, components, stores, flows, transfers and outputs that combine to form distinctive landscapes

Question 3

What is a dynamic equilibrium?

Answer 3

When there is a balance between the inputs and outputs then the system is in a state of dynamic equilibrium. If one of the elements of the system changes, then the beach features may change and the equilibrium is upset, the dynamic equilibrium is upset by extreme events such as storms, humans can also cause disruption to it for example by removing beach material

Question 4

What is positive feedback?

Answer 4

Where the effects of an action are amplified or multiplied by subsequent knock -on effects (normally done by people)

Question 5

What is negative feedback?

Answer 5

Where the effects of an action are nullified by its subsequent knock-on effects (normally through natural processes)

Question 6

Output

Answer 6

Material or energy moving in from the system to the outside e.g. ocean currents, rip tides, sediment transfer, evaporation

Question 7

Input

Answer 7

Material or energy moving in to the system from the outside e.g. precipitation or wind

Question 8

Energy

Answer 8

Power or driving force e.g. energy associated with flowing water, the effects of gravity on cliffs and moving air

Question 9

Stores/components

Answer 9

The individual elements or parts of a system e.g. beach, sand dunes, nearshore sediment

Question 10

Flows/transfers

Answer 10

The links or relations between the components e.g. wind-blown sand, mass movement processes, LSD

Question 11

Positive feedback examples

Answer 11

Coastal management can inadvertently lead to an increase in erosion elsewhere along the coast. Groynes trap sediment, depriving ares further down of beach replenishment, this can increase erosion. Sea walls have the same effect by transferring high energy waves elsewhere along the coast

Question 12

Negative feedback examples

Answer 12

When the rate of weathering and mass movement exceeds the rate of cliff-foot erosion a screw is formed. Over time, this material extends up the cliff face protecting the cliff face from subaerial processes. This leads to a reduction in the effectiveness of weathering and mass movement

Question 13

Dynamic equilibrium

Answer 13

A state of balance within a constantly changing system e.g. constructive waves build up a breach, asking it steeper, this encourages the formation of destructive waves that plunge rather than surge. Redistribution of sediment offshore by destructive waves reduces the beach gradient. This encourages waves to become more constructive

Question 14

Backshore

Answer 14

Area between the high water mark and landward limit of marine activity. Changes take place during storm activity

Question 15

Foreshore

Answer 15

Area between the high water mark and the low water mark. Most important zone for marine processes that are not influenced by storm activity

Question 16

Inshore

Answer 16

Area between the low water mark and the point where waves cease to have any influence on the land beneath them

Question 17

Offshore

Answer 17

Area beyond the point where waves cease to impact upon the seabed. Activity is limited to deposition of sediments

Question 18

Wind

Answer 18

Wind is a vital input into the coastal system as it is the primary source of energy for other processes. It is also and important agent of erosion and transportation

Question 19

4 Features of wind as an input into the coastal system

Answer 19

Prevailing wind
Fetch
Formation of waves
Agent of erosion

Question 20

Prevailing wind

Answer 20

Most coastlines have a direction that the wind comes from most often. This influences the amount of wave energy. Our prevailing wind is from the South

Question 21

Fetch

Answer 21

This is the distance of open water over which a wind blows interrupted. The length of fetch determines the magnitude of energy of the waves

Question 22

Formation of waves

Answer 22

Waves are created by the transfer of energy from the wind blowing over the sea surface. The energy acquired by the waves depends on the stretch of the wind

Question 23

Agent of erosion

Answer 23

Wind can pick up and move sediment from the coast, and also use it to erode other features

Question 24

Waves

Answer 24

Once created and driven by the wind, they are the primary agent of shaping the coast

Question 25

Characteristics of constructive waves

Answer 25

Wave height- low, under 1 metre
Wavelength- long
Frequency- 8-10 waves per minute
Smash- strong smash
Backwash- weak backwash
Beach profile- gentle/flat

Question 26

Characteristics of destructive waves

Answer 26

Wave height- over 1 metre
Wavelength- short
Frequency- 10-14 waves per minute
Swash- weak swash
Backwash- very strong backwash
Beach profile- Steep

Question 27

Wave refraction

Answer 27

The shape of the coastline can cause waves to bend and change direction
- As each wave approaches the coast, it drags in the shallow water at the headland. This increases the wave height and shortens the wavelength and results in increased erosion at the headland. Lower energy waves spill into the bays either side, resulting in increased deposition

Question 28

What is a current?

Answer 28

The term current refers to the permanent of seasonal movement of surface water in the seas and oceans

Question 29

There are three main types of current:

Answer 29

Longshore currents (littoral drift) – most waves do not approach the headline ‘head on’, but rather at an angle to the shoreline. This generates a current running parallel to the shoreline.
Rip currents- these are strong currents moving away from the shoreline.
They develop when seawater is piled up along the coastline by incoming waves. The current may run parallel to the coast before flowing out through the breaker zone.
Upwelling – this is the movement of cold water from deep oceans towards the surface. The denser cold water replaces the warmer surface water and creates nutrient rich cold Ocean currents.

Question 30

Tides:

Answer 30

The Sun and moon both have an influence on the tides, but the moons influence is stronger, as it is closer
The moon pulls water towards it, creating a high tide in that part of the world, and there’s a compensatory high tide on the opposite side of the world. In the areas between this, the tides is at its lowest
There is a high tide every 12.25 hours on average
The tidal range is the vertical distance between high tide and low tide. Low tile range tends to produce a narrower beach, which is prone to higher rates of erosion

Question 31

Two types of tides:

Answer 31

Spring tides – as the moon orbits the Earth the high tide follow it. Twice in a lunar month, when the moon, sun and earth are in a straight line, the tidal force is amplified. This produces the highest monthly tides (spring tides)
Neap tides – also twice a month, the moon and the Sun are positioned at right angles to one another in relation to the Earth. This alignment gives the lowest monthly tidal range (neap tides)

Question 32

Characteristics of high energy coasts

Answer 32

Energy level – high energy waves
Deposition vs erosion – the rate of erosion is greater than the rate of deposition
Landforms – headlands, cliffs, wave cut platforms
Examples – Atlantic coast of northern Europe and Northern America
North Cornish coast in Southwest England

Question 33

What are tidal surges?

Answer 33

Also known as storm surges
They are occasions when meteorological conditions give rise to strong winds which can produce much higher water levels than those at high tide
The east coast of Britain and the north Sea are affected by this
Depressions (intense low pressure weather systems) over the north sea produce low pressure conditions that have the effect of raising sea levels
Sea levels can rise by 1 cm for every 1 millibar drop in pressure
Strong winds drive waves ahead of the storm, pushing the sea water towards the coastline
This has the effect of piling up water against the coast
The shape of the north Sea means that often water is increasingly concentrated into a space that is decreasing in size (tunnelling)
High tides, especially those of spring tide, intensify the effect
The north Sea was affected by a title surge in 1953
Storms and surges of December 2013 and January 2014 brought some places along the east coast of England higher water levels than 60 years earlier

Question 34

Characteristics of low energy coasts

Answer 34

Energy level – low energy waves
Deposition vs erosion – rate of deposition often exceeds the rate of erosion of sediment
Landforms – beaches, spits, estuaries, inlets, sheltered bays, Examples – Baltic Sea is an example (has sheltered waters and low tidal rage)

Question 35

Sediment sources

Answer 35

Sediments comes from a variety of sources, including:
Streams or rivers flowing into the sea
Estuaries
Cliff erosion
Offshore sand banks
Material from biological origin (shells or coral fragments)

Question 36

What are sediment cells?

Answer 36

A sediment cell is a length of coastline and it’s associated near shore area within which the movement of coarse sediment (Sand and shingle) is largely self-contained.
Interruptions to the movement of sand and shingle within one cell should not affect beaches in a neighbouring sediment cell
The English and Welsh coastlines are divided into 11 cells which are then divided into sub-cells or management units
Sediment cell theory is a key component of shoreline management plans (SMP) which determine future strategies
Sediment cells are distinct areas of coastline separated from other areas by well-defined boundaries such as headlands and stretches of deep water
Sediment cells can be regarded as closed systems (from which nothing is gained or lost)

Question 37

Sediment cell characteristics

Answer 37

They are discreet and function separately from each other
Within the cell sediment is sourced transferred and stored. Coarse sediments are not exchanged between cells, but finer sediment in suspension can be
Overtime, sub-sinks (temporary stores) will erode, and the sediment will re-enter the cell system
The sentiment in the sink is away from wave action and longshore drift. It becomes essentially an output as it is no longer being worked by the processes within the cell.

Question 38

What is a sediment budget?

Answer 38

The amount of sediment available to the sediment cell
The sediment cell will produce depositional features which are in equilibrium with the amount of sediments available. If the budget is decreased, then the waves will continue to move sediment, causing erosion in some areas. if the budget increases, then deposition is more likely. More material ADDED to the cell than removed- a net accretion of material, this is a positive budget, or a surplus of sediment, the shoreline builds towards the sea.
More material REMOVED from the cell than is added, this is a negative budget, or a deficit in sediment supply, the shoreline retreats landward

Question 39

Examples of inputs, transfers and stores

Answer 39

Inputs (sources of sediment) – fluvial sediment, cliff erosion, erosion of wave cut platforms, eroding depositional features e.g. beaches, dunes
Transfers (transportation) – longshore drift, current, saltation
Stores (sinks) – sinks/permanent storage = estuary, offshore bar, dredging (removal of sediment), submarine canyon
Sub-sinks /temporary stores = sedimentary features e.g. Beaches, dunes, spits, bars

Question 40

What is longshore drift?

Answer 40

The movement of material caused by the approach of swash at an angle to the shore and the subsequent perpendicular backwash down the steepest beach gradient which moves the material laterally downdrift. Aided by wave refraction

Question 41

Geomorphological processes

Answer 41

There are two types:
Marine – processes that operate on the coastline that are connected with the sea, such as tides, longshore drift and waves e.g. Transport by waves, deposition by waves, processes of marine erosion
Sub aerial – these operate on land but also affect the shape of the coastline such as mass movement, weathering and run-off. These processes break down the coastline, weaken underlying rocks and allow sudden movements or erosion to happen more easily. Material is broken down IN SITU meaning it remains in its original position e.g. all types of weathering and mass movement, deposition by wind and transport by wind

Question 42

Processes of marine erosion

Answer 42

Attrition – rocks in the water crash into each other, becoming smaller rounder
Abrasion – material in the water thrown against cliff faces and wears them away
Solution – dissolving of rocks in water such as calcium and based rocks like limestone
Wave quarrying – force of air getting into cracks in rock, creating pressure and forcing rocks apart
Hydraulic action – force of water getting into cracks in rock, creating pressure and forcing rocks apart

Question 43

Factors affecting erosion at the coast

Answer 43

Wave steepness – steeper waves are high energy waves and have greater erosive power than low energy waves
Breaking point – waves that break at the foot of the cliff release more energy than those that break some distance from the shore
Fetch- (the distance travelled by wind or waves across open water) a wave that has travelled further have more energy than one that has not travelled as far
Sea depth- a steeply shelving seabed at the coast will create higher and steeper waves
Beach presence- beaches absorb wave energy and can therefore provide protection against marine erosion
Human activity – if protective material such as sand and shingle are removed from beaches it may lead to more erosion. Construction of groynes will reduce erosion where they are built but may increase erosion somewhere else along the same coastline
Geology

Question 44

Geology is a very important factor in rates of erosion at the coast: Geomorphological processes

Answer 44

Lithology: refers to the characteristics of rocks, such as resistance to erosion and permeability e.g. very resistant rocks such as granite tend to be eroded less than weaker rocks such as clay. The variation in rates at which rocks wear away is known as DIFFERENTIAL EROSION
Structure: the structure and layout of rocks can affect erosion. Rocks that live parallel to the coast (concordant) creates very different types of coastline then those right angles (discordant)

Question 45

Discordant coastlines

Answer 45

Rocks run at right angles to the coast, allowing the sea to erode weaker clays and sandstones to create large bays e.g. Swanage Bay in Dorset
The harder rock either side is eroded more slowly and creates headlands e.g. Peveril point in Dorset

Question 46

Concordant coastlines

Answer 46

Rocks run parallel to the coast. If the rock closest to the sea is made of limestone e.g.
Portland limestone in Dorset, then Cliffs form as they are more resistant. In a few places, the sea is able to erode through the limestone and a road the week of rock behind it e.g. Lulworth cove

Question 47

Examples of hard and soft rock

Answer 47

Hard rock – chalk, Purbeck limestone, Portland limestone, granite
Soft rock – Kimmeridge clay, Bagshot beds, Wealdon clays and green Sands

Question 48

What is a dip?

Answer 48

The steepest cliffs form in rocks that have horizontal strata (lines) or which dip gently inland. Rocks that dip towards the coast tend to produce much more gently sloping features.

Question 49

Strata

Answer 49

The direction of the layers of the geology

Question 50

Situations where (marine) deposition occurs

Answer 50

When sand and shingle accumulate faster than they are removed
As water slows following breaking
As water pauses at the top of the swash before the backwash begins
When water percolates (travels through the ground) into the beach material As backwash takes it back down the beach

Question 51

What is aeolian deposition?

Answer 51

Aeolian processes refer to transport and deposition of sediment BY WIND
Wind plays an important role in shaping many coastlines
At the coast, when there is a large tidal range, large amounts of sand may be exposed at low tide providing a supply of sediment to be picked up by the wind
Sand is transported by the wind in two ways (dependent on how dry or moist the source of sand is)
Soil creep- a process like traction, where wind rolls or slides sand grains along the surface
Saltation – Where the wind is strong enough to temporarily lift the grains up to 1 meter

Question 52

Sub-aerial processes: weathering

Answer 52

Sub-aerial weathering includes processes that slowly breakdown the coastline, weaken the underlying rocks and allow sudden movements or erosion to happen more easily
Material is broken down in situ, remaining in its original place, it is then moved by mass movement
Sub- aerial weathering at the coast can be categorised as:
Mechanical/physical weathering
Biological weathering
Chemical weathering

Question 53

Mechanical/ physical weathering

Answer 53

Examples:
Freeze-thaw: Water that enters cracks in the rocks freezes as temperatures remain below 0C. As it freezes, the water expands by almost 10 per cent, meaning the ice occupies more space and so exerts pressure on the surrounding rock. As the process repeats and continues, the crack widens and eventually pieces of rock break off
Pressure release: where processes of erosion, weathering and mass movement remove overlying material

Question 54

Biological weathering

Answer 54

These are processes that lead to the breakdown of rocks by the action of vegetation and coastal organisms, biological weathering is quite active in coastlines.
Examples:
Some marine organisms, e.g. piddock, have specially adapted shells that enable them to drill into solid rock
Seaweed attaches itself to rocks and the action of the sea can be enough to cause swaying seaweed to prise away loose rocks from the sea floor
Some organisms e.g. algae, secrete chemicals capable of promoting solution
Animals can weaken cliffs as they burrow or dig into them e.g. rabbits

Question 55

Chemical weathering

Answer 55

This occurs where rocks are exposed to air and moisture so chemical processes can break down the rocks.
Examples: Oxidation- causes rocks to disintegrate when the oxygen dissolved in water reacts with some rock minerals, forming oxides and hydroxides
Solution- the main chemical process
Hydrolysis- where mildly acidic water reacts or combines with minerals in the rock to create clays and dissolvable salts; this itself degrades the rock

Question 56

Sub aerial processes: mass movement

Answer 56

Mass movements are generally either rapid sudden failures of the slope or the effects of processes that develop over some time. No mass movement is possible without the influence of gravity
Types of mass movement:
Rock fall
Landslide
Soil creep
Mud slide
Slumping
Run-off

Question 57

Depositional landforms : beaches

Answer 57

Ripples- features formed as the tide goes out, only visible in low tide, waves retreat creating ripples
Runnels – a dip filled with water (between ridges/berms)
Ridges – when the tide goes in or out, the waves will deposit the sediment when the gradient changes, creating ridges, the beach is not flat
Cusps- naturally formed semi- circular patterns, when wave refraction occurs on a headland, the wave energy is spread out into the bay, therefore the swash divides creating a stronger backwash creating cusps
Offshore bars- typically happen during winter due to disruptive storms/waves. The beaches are eroded, transported and deposited offshore, can’t see offshore bars as they are below the low tide mark
Berms- like a ridge that is further inland, nearer the backshore (inland), it’s only affected during storms or high tide

Question 58

Depositional landforms: mudflats

Answer 58

Mudflats:
Often located in estuaries or on the landward side of a spit
Low lying areas of the shore that are submerged at high tide
Composed of silt and clay
In estuaries, fresh water from the river mixes with the salty sea water at high tide, then process of flocculation occurs
At low tide the inter-tidal area of mud is left exposed
They are not necessarily permanent and are susceptible to changes in sea level, wave action, amount of waste from the river and tides

Question 59

What is flocculation?

Answer 59

Flocculation is a depositional process by which clay particles clump together through electrical or chemical attraction, and become large enough to sink

Question 60

Swash vs drift aligned beaches

Answer 60

The angle at which waves generally approach a coastline will determine the nature of the kind of beach features that develop
Swash aligned beaches:
e.g. Hell’s Mouth
They are produced where the waves break in line (parallel) with the coast. Swash aligned beaches are smoothly curved, concave beaches
The Beach face is orientated parallel to the front of the dominant waves
Beaches which face the waves are termed SWASH ALINGED
Drift aligned beaches:
They are produced where waves break at an angle to the coast
The swash therefore occurs as an angle, but the backwash runs perpendicular to the beach
As a result, material is transported along the beach via longshore drift

Question 61

What does pioneer mean?

Answer 61

The first species
e.g. marram grass are the first species of vegetation to colonise sand dunes

Question 62

Several key conditions are necessary for sand dunes to form:

Answer 62

Sand dunes e.g. Studland Bay Dorset need:
A supply of sand- this can be brought onshore by the waves and positive on large sandy beaches or spits
A large inter-tidal beach area- where sand can be dried out at low tide
Strong onshore prevailing winds- to pick up the dry sand and blow it inland
Obstacles- such as plants, driftwood, or rocks to trap the sand
A large, flat, low lying area- of land behind the beach where the dunes evolve over time

Question 63

What is a psammosere?

Answer 63

The vegetation succession and development of the sand dune

Question 64

What is a bar?

Answer 64

A long stretch of sand stretches across a bay leaving a lagoon behind, if a spit develops across a bay where there is no strong flow of water from the landward side, it’s possible for the sediment to reach across to the other side, forming a bar e.g. Slapton Ley in Devon

Question 65

Simple vs Compound spits

Answer 65

Simple spits- straight or recurved
Do not have minor spits, or recurved edges
Compound spits- may have similar features to simple spits
Have several recurved ridges (ends) or minor spits, possibly marking where they terminated in the past

Question 66

How are spits formed?

Answer 66

Prevailing wins and maximum fetch are from the south-west, so material is carried west to east by longshore drift
The change in coastline to a north-south angle causes a buildup of sand and shingle in the more sheltered water in the lee of the headland
Find a material is carried Eastwards into the deeper water of the estuary and is deposited as the water loses its capacity to transport it
The end of the spit begins to curve round as wave refraction carried material round into the more sheltered area, the fetch may also contribute to this. Behind the spit is now sheltered which encourages more deposition of sediment, and a salt marsh can form over time

Question 67

What is a tombolo?

Answer 67

A long stretch of sand joining an island to the mainland, a spit that joins an island to the mainland is Tombolo e.g. Chesil beach on the South Coast of the UK, which joins the Isle of Portland to the mainland

Question 68

What is brackish water?

Answer 68

Water found in salt marshes
Salt and freshwater

Question 69

Eustatic change

Answer 69

A global change in sea level resulting from an actual fall or rise in the level of the sea itself

Question 70

Isostatic change

Answer 70

Local changes in sea level resulting from land rising or falling relative to the sea

Question 71

Causes of eustatic sea level change

Answer 71

-Switching between ice age and interglacial periods
-The density of the water increases (thermal expansion) or decreases as the temperature rises or falls
-Changes in the global ocean volume due to plate tectonic movement

Question 72

Eustatic rise

Answer 72

Sea levels rise in relation to the land

Question 73

Eustatic fall

Answer 73

Sea levels decrease in relation to the land

Question 74

Why does eustatic fall occur?

Answer 74

As the climate begins to get cooler, marking the onset of a new glacial period, an increasing amount of precipitation falls as snow. Eventually, the snow turns into glacier ice. Snow and ice act as a store for water, so the hydrological cycle slows down. So water cycled from the sea to the land does not return to the sea. Therefore, sea levels fall and this affects the whole planet.

Question 75

Why does eustatic rise occur?

Answer 75

As we enter an inter-glacial period, the ice masses on the land begin to melt. This causes sea levels to rise worldwide.

Question 76

Isostatic change in a localised change and may be due to:

Answer 76

Post glacial adjustment- during a period of glaciation, extremely heavy ice sheets weigh land down. When the glacial period ends and the ice melts, the land will rebound to a higher level, lowering the sea level in a process known as Isostatic recovery or readjustment.
Accretion- Within the sediment cell, there are areas of net deposition causing land to build up.
Subsidence- Caused by the lowering of the water table or increased deposition weighing down the sediment.
Tectonics- The folding of the sedimentary rock. Lava and ash from volcanoes increase the height of the land relative to the sea level.

Question 77

Isostatic recovery stats:

Answer 77

The UK is still experiencing Isostatic recovery from the end of the last ice age:
Land in the North in Scotland is still rebounding and rising by approximately 1.5mm a year.
Land’s End in Cornwall is sinking by 1mm each year.

Question 78

Eustatic sea level change: Temporal Variations

Answer 78

Sea level varies daily due to tides. Onshore winds and low atmospheric pressure systems can cause sea levels to rise temporarily.
On a much longer timescale, global sea level has changed by a much larger amount. Around 21,000 years ago, sea level was about 130m lower than present day.

Question 79

Sea level change causes two distinct features:

Answer 79

Submergent features and Emergent features

Question 80

Submergent features:

Answer 80

Features that have been submerged by rising sea levels or Isostatic depression

Question 81

Emergent features:

Answer 81

Features that have formed due to decreasing sea levels or Isostatic recovery

Question 82

What are Rias?
(Submergent)

Answer 82

Flooded river valleys.
As sea levels rise, the floodplain of a river will vanish beneath the rising waters. Rising sea levels drown the valleys or rivers.
e.g. Fowey Estuary in Cornwall and Kingsbridge estuary in South Devon

Question 83

What are Fjords?
(Submergent)

Answer 83

Drowned glacial valleys typically found on the coasts of Norway, Southwestern New Zealand and Greenland. They were formed when the sea drowned the lower part of glacial valleys that were cut to a much lower sea level.
They have steep valley sides, a typical U shaped cross section with hanging valleys on either side. Unlike rias, they are not deepest at the mouth, but generally consist of a glacial rock basin with a shallower section at the end (the threshold). The threshold is thought to be due to reduced glacial erosion as the glacier met the sea and the ice became thinner.E.g. Sogne Fjord in Norway, which is nearly 200km long and Milford Sound in New Zealand.

Question 84

What is a Dalmatian coast?
(Submergent)

Answer 84

A Dalmatian coast is formed where the topography of the land runs parallel to the coastline (concordant) and becomes flooded by sea level rise, causing there to be flooded river valleys. (They run parallel to the coast instead of at right angles to it (rias and fjords) E.g. The Dalmatian Coast in Croatia

Question 85

Raised beaches
(Emergent)

Answer 85

Also known as marine terraces. They are area of former wave-cut platforms and their beaches, which are at a level higher than the present sea level. E.g. Common on the Isle of Arran in Scotland.
At the back of a raised beach is a relic cliff and often caves
It can be referred to as a marine platform if a greater expanse of gently sloping formerly submerged has been exposed by uplift or the lowering of sea levels

Question 86

What are two sustainable approaches to Coastal Flood Erosion Management?

Answer 86

SMPs and ICZMs

Question 87

Shoreline Management Plans (SMPs)

Answer 87

There are 22 SMPs around the coast of England and Wales corresponding to sediment cells and sub-cells. SMPs are designed to identify the most sustainable approach to managing the flood and coastal erosion risks to the coastline.

Question 88

SMPs aim to plan for the:

Answer 88

Short term (0-20 years)
Medium term (20-50 years)
Long term (50-100 years)

Question 89

There are four defence options within an SMP:

Answer 89

Hold the line- retain existing coastline by maintaining current defences or building new ones
Advance the line- build new defences seaward of the existing line
Retreat the line- actively manage the rate and process by which the coast retreats
Do nothing- where it is not economically or environmentally viable to build defences (HARD)

Question 90

SMP key features:

Answer 90

Address risks in a sustainable way
Aim to be environmentally acceptable and economically viable
Comply with international and natural nature conservation and biodiversity legislation
Provide a foundation for future research and development of new coastal management strategies in the future
They are ‘live’ working documents that are continually reviewed and updated

Question 91

Integrated Coastal Zone Management (IZCM)

Answer 91

The term IZCM originated from the UN Earth Summit in 1992.
It aims for coordinated application of the different polices affecting the coast and related activities such as nature protection, aquaculture, fisheries, agriculture, tourism and offshore wind energy.
It is sustainable as it is an approach that respects the limits of natural resources and ecosystems (ecosystem - based approach).
ICZM covers the full cycle of information collection, planning, decision-making, management and monitoring of implementation. All stakeholders are involved to ensure broad support for the implementation of management strategies.
In the past, coastal management was often viewed as having a sectoral approach, where the local authorities made decisions for their stretch of the coastline, however at the same time, other agencies and interest groups tried to manage their environment, cause or social group.
This led to decisions that undermined each other, an inefficient use of resources and failure to meet sustainability objectives. This is why ICZMs are designed to integrate the interests of all stakeholders to avoid such problems.

Question 92

What is soft engineering?

Answer 92

Uses natural systems for coastal defence such as beaches, dunes and salt marshes. It involves manipulating and maintaining these systems without changing their structures.

Question 93

Soft engineering: Beach nourishment

Answer 93

Replaces material that has been lost through longshore drift. This may happen especially before the start of the tourist season.
Disadvantages: higher costs overtime and repeated disturbance of the ecosystem. E.g. Meers bank

Question 94

Soft engineering:
Dune regeneration

Answer 94

Dunes are replanted with marram grass to stabilise the surface.
Disadvantages:
Can be easily damaged by storm waves
Protection is limited to a small area so not much of the beach is protected
Areas have to be fenced/zoned off from the public while they grow so during this time, the beach can’t be used for recreational purposes. E.g. Newborough Warren

Question 95

Soft engineering: Managed retreat

Answer 95

Current sea defences are abandoned and the exposed land is developed in some way (e.g. with salt marshes to reduce wave power) and this new area cam act as a defence against rising sea levels
Disadvantages:
Land is lost as it is reclaimed by the sea
Landowners need to be compensated for this which can cost between £5000-£10000 per hectare
E.g. California

Question 96

Soft engineering: Land-use management

Answer 96

This involves addressing people’s behaviour and educating the local community. Landowners can be encouraged to think about how they can continue to use the land that is at risk.
Disadvantages:
Only works if the local population agree to having their use of land limited
Cannot remedy damage that has already be done
E.g. New Forest National Park

Question 97

Soft engineering:
Do nothing

Answer 97

It is debatable whether the coast should be protected as hundreds of millions of pounds are spent annually in the UK on coastal protection. It might be cheaper to just let nature take its course and pay compensation to those affected.
Disadvantages:
Storms can accelerate erosion with strong winds and waves E.g. Devon

Question 98

What is soft engineering?

Answer 98

Making a physical change to the coastal landscape using resistant materials, like concrete, wood, boulders and metal

Question 99

Hard engineering:
Sea wall

Answer 99

Aim to dissipate wave energy. A recurved structure throws waves back out to sea into the path of the next incoming wave, reducing the impact. They provide a physical barrier to flooding by raising the height of the coastline.
Disadvantages:
It can cause erosion of the beach seaward of the structure
E.g. Scarborough/ Heysham and Morecambe

Question 100

Hard engineering:
Rock armour

Answer 100

Large boulders placed in front of a cliff or sea wall to take full force of the waves. The boulders are deliberately left angular in appearance to present a large surface area to the waves and create gaps for water to filter through.
Disadvantages:
Strong waves can cause the rocks to look more natural than a concrete wall
E.g. West Wittering

Question 101

Hard engineering:
Gabions

Answer 101

They are small boulders contained in steel wire mesh cages, each of which can be joined together to form larger structures or walls.
Disadvantages:
They are dangerous if damaged- sharp wire mesh is hazardous
E.g. Heysham and Morecambe

Question 102

Hard engineering:
Revetments

Answer 102

Concrete or wooden structures placed across a beach or coastline to take the full force of wave energy, preventing further erosion of the coast.
Disadvantages:
Erosion at the base of the structure can cause structure failure
E.g. Heysham and Morecambe

Question 103

Hard engineering:
Groynes

Answer 103

Wooden, stone or steel structures built at right angles to the waves. They are built to control longshore drift by trapping sediment to create higher and wider beaches which will then also dissipate wave energy. They help to break up waves as they hit the coast.
Disadvantages:
Starve areas further down the beach or sediment
E.g. Heysham and Morecambe

Question 104

Hard engineering:
Cliff fixing

Answer 104

Often done by driving metal bars into the cliff face, both to stabilise it and to absorb some wave power.
Disadvantages:
It affects the biodiversity of an area i.e. sharp wire for birds
E.g. Scarborough

Question 105

Hard engineering:
Barrages

Answer 105

Large structures built to prevent flooding on major estuaries and other large sea inlets. They act as a dam across an estuary.
Disadvantages:
They have very high civil infrastructure costs
E.g. The Rance Tidal Power Station in Brittany, France

Question 105

Hard engineering:
Offshore reefs

Answer 105

These force the waves to break offshore, which reduces their impact on the base of cliffs . Sometimes redundant ships have been deliberately sunk parallel to the shore to both slow down approaching waves and to act as a substructure for reef material to colonise.
Disadvantages:
May be removed by heavy storms
Difficult to install

Question 106

Background of the Holderness Coast:

Answer 106

The coastline is 61km long (Flamborough Head in North to Spurn Head in South).
It is one of Europes fastest eroding coastlines with an average annual erosion rate of around 2 metres per year. The main reason for this is because the coastline is made up of unconsolidated glacial till (very soft clay) . This material was deposited by glaciers around 12,000 years ago.
The coastline stretches along the coast of the East Riding of Yorkshire, known as Holderness.
Since Roman Times, the Holderness Coast has retreated 4km- at least 29 villages have been lost to the sea

Question 107

What makes the Holderness coast so vulnerable to erosion?

Answer 107

Holderness is exposed to wind and waves from the north-east, with a fetch of 500-800k, across the North Sea. Others factors increase the size of the waves as well:
Currents(or swell)- they move northwards around the UK from the Atlantic and into the North Sea. The Atlantics fetch is 5000km so its currents add even more energy to waves, causing powerful destructive waves.
Weather systems- these, as well as winter storms in the North Sea are often intense. The low pressure raises the sea level, producing higher tides than normal and the storms add energy to the waves, especially in storms.
The sea floor is deep in the North Sea- this means that waves hit the coast relatively fast and are not slowed down by friction.
(Material)- The Holderness coastline is made up of soft boulder clays (tills) left after the retreat of the Devensian ice sheets about 12,000 years ago. The soft boulder clay is easily eroded by wave action. E.g. In Great Cowden, the rate of erosion has been over 10m/year.
The boulder clay is also prone to mass movement such as slumping, water makes the clay heavier and acts as a lubricant between particles which makes it unstable. The erosion of this boulder clays produces very small, fine clay particles, which are easily transported by LD out to the sea and along the coast. Due to this, there is little sediment accumulation in front of the cliffs to form a layer of protection from the cliffs.
Beach shape- the beaches are narrow and fail to absorb the wave energy, and during high tide there is not enough beach and waves hit the base of the cliffs.
Prevailing winds- These winds from the northeast transport material southwards through longshore drift. These winds also create an ocean current and transport material south. Where the ocean current meets the outflow of the River Humber, the flow becomes turbulent and sediment is deposited.

Question 108

The distinctive coastal landscape of Holderness:

Answer 108

Flamborough Head- the geology here consists of chalk, this has created headlands, wave-cut platforms, cages, arches and stacks. The area to the South of FH is sheltered from wind and waves.
Bridlington Bay-
A wide sand ans pebble beach has formed near here. There are frequent slumps due to the boulder clay, making the cliff tiered e.g. around Atwick Sands.
Spurn Head- Sand dunes have formed around SH due to material being transported and deposited by the wind. Erosion and longshore drift have created a spit with a recurved end across the mouth of the Humber Estuary (called Spurn Head). To the landward side of the spit, mudflats and saltmarshes have formed.

Question 109

Why does the Holderness coastline need management?

Answer 109

Socio-economic reasons:
The numbers of visitors to areas along this coastline has dropped.
Money has to be spent on coastal management and protection.
The Gas Terminal in Easington, which supplies 25% of Britain’s gas is at risk.
80000m2 of farmland is lost each year, this has a huge affect on farmer’s livelihoods.
Some settlements are unable to maintain a viable population to warrant shops.
Properties under threat of erosion lose their value leaving owners with negative equity. There is no financial help to aid people as no compensation is paid out for the loss of private property or land caused by coastal erosion in England.
It’s predicted that 200 homes and several roads will fall into the sea by 2100.
Many of the settlements rely heavily on tourism, as facilities close down, the settlements are unable to maintain a good population.
Around 30 villages have been lost since Roman times, meaning homes and businesses have been lost.
Environmental reasons:
Potential of increased pollution from infrastructure falling into the sea.
Some SSSIs (sites of special scientific interest) are threatened by erosion.
Wildlife behind Spurn Head is losing diversity as the environment cannot support many species due to the lack of sediment.

Question 110

Current Hard engineering on the Holderness Coast:

Answer 110

11.4km of the 61km coastline has hard engineering.
Bridlington- 4.7km long sea wall and wooden groynes
Skipsea- gabions in front of a caravan park
Hornsea- concrete sea wall, wooden groynes and rock armour
Mappleton- two rock groynes and a 500m long revetment
Withernsea- groynes, sea wall, rock armour
Easington- has a rock revetment
Spurn head- groynes, rock armour on the eastern side
There are higher rates of erosion directly south of these defences that is due to the flow of beach material by longshore drift being stopped by protection methods such as groynes, sea walls and rock armour.
Hornsea may well be protected but places like Mappleton, directly south are starved of material and are eroding at excessive rates, this is called TERMINAL GROYNES SYNDROME

Question 111

Why are the current hard engineering strategies at Holderness not sustainable?

Answer 111

Groynes trap sediment, increasing the width of beaches. This protects the local area by increases erosion of the cliffs to the south.
The sediment produced from the erosion of the Holderness coastline is normally washed into the Humber Estuary and down the Lincolnshire coast. Reduction in this sediment increases the risk of flooding along the Humber Estuary and increases erosion along the Lincolnshire coast.
The protection of local areas is leading to the formation of bays between those areas. As bays develop, pressure on headlands will increase due to wave refraction, and eventually, the cost of maintaining the sea defences become too high.

Question 112

The SMP of Holderness:

Answer 112

For the next 50 years, the SMP recommends holding the line at some settlements and doing nothing along the less populated stretches. However, this is unpopular with owners of land or property along the stretches where nothing is being done.
Managed realignment has been suggested which is more sustainable than other strategies, but there are issues around how much compensation businesses will get for relocating. Relocating also isn’t always possible if there is no land for sale to relocate buildings to.
In 1995, the Holderness Borough Council decided to stop trying to protect Spurn Head from erosion- do nothing became the new strategy which saves money and allows the spit to function materially, but over-washing may damage the marsh environments behind the spit.
Easington Gas Terminal is currently protected by rock revetments, and the SMP recommends that these are maintained for as long as the gas terminal is operating. However, the defences only span about 1km in front of the terminal, meaning that the village of Easington (population 7000) isn’t protected. The defences also may increased erosion at SSSIs to the south.

Question 113

Opportunities in the Sundarbans:

Answer 113

Social:
The Sundarbans region is home to around 4.5 million people.
The mangrove ecosystem provides local people with fish, crabs, honey and nipa palm leaves.
There are opportunities for tourism- visitors are attracted by the mangroves and wildlife.
The Rampal Power station has been built just north of the Sundarbans national park, providing energy for people in the region.
Economic:
The mangroves provide people with timber for construction, firewood and furniture.
Since 2011, cargo ships transporting goods such as oil and food inland have been allowed to use the waterways, so channels have been dredged to make passage easier for the ships.
Environmental:
The flat, fertile land is perfect for growing crops, particularly rice
Mangrove forests also provide a natural defence against flooding, and their roots help to protect against coastal erosion, by binding the soil together.

Question 114

Challenges in the Sundarbans:

Answer 114

Natural challenges:
Coastal flooding from rising sea levels
Cyclones
Lack of freshwater
Dangerous predators
Instability of the islands
High levels of salinity (amount of salt) in the soil
Accessibility and remoteness

Human challenges:
Lack of income and employment opportunities
Over-exploitation of coastal resources from vulnerable habitats (growing population needing more fuel)
Resource-use conflicts
Lack of awareness of environmental and economic importance of the region
Conservation of wetlands to intensive agriculture and settlements
Lack of awareness of coastal issues by decision makers
Destructive fishing techniques

Question 115

The Sundarbans background:

Answer 115

The Sundarbans is a coastal zone occupying the world’s largest delta, that extends over 10,000km2 of Southern Bangladesh and India in the Bay of Bengal.
The delta is formed from the sediment deposited by three of the world’s great rivers, the Ganges, Brahmaputra and the Meghna.
The natural ecosystems of the Sundarbans are mangrove forests and swamps.

Question 116

Coastal processes in the Sundarbans:

Answer 116

Tidal action is the primary natural process that shapes this landscape.
There are many clay and silt deposits that are quite resistant to erosion, causing the network of main channels to remain static. The larger channels are 1-2km wide and flow from north to south due to strong tidal currents.
The extensive network of interconnecting smaller channels (khals) drains the land with each powerful ebb tide.
The non-cohesive sediments like sand are washed out of the delta and deposited on banks at the river mouth, where the strong south-westerly monsoon winds then blow them into large ranges of sand dunes, protecting them.
Vegetation establishes itself and eventually, the natural succession of mangroves are created, which are home to the Royal Bengal Tiger.
These diverse mangrove forests have sustained local population for generations. However, the equilibrium of the natural processes that exist here is very delicate and the increasing pressures that are placed on it may be jeopardising its existence.

Question 117

Sundarbans facts:

Answer 117

28 species of mangroves
Mangrove biome
Mangroves are adapted to survive bc they have roots to anchor them and they are tolerant to brackish water
Mangroves live in the coastal intertidal zone
Mangroves lock away carbon as they grow
Nutrient rich sediment alongside high temperatures help mangroves become one of the most productive ecosystems on the planet
Net primary productivity- The net carbon gain by vegetation over a particular time period- typically a year
Without carbon in the mangroves, the royal bengal tiger wouldn’t be there
Otters, mudskippers, saltwater crocodile, gengetic dolphins all live in the Sundarbans
50000-80000 spotted deer are supported by the mangroves
300 species of birds e.g. kingfisher, whistling duck

Question 118

What is resilience?

Answer 118

Resilience means being able to cope with the challenges the environment presents

Question 118

Sundarbans as a biodiversity hotspot:

Answer 118

The carbon rich sediment has created fossil fuels and carbon sequestration in the water
Over 4.5 million people live near the banks of the Sundarbans
British rulers cleared the Sundarbans for forest, agriculture and colonial control
Authorities use permits or quotas to limit how much product is taken out from the Sundarbans due to illegal activity and poverty
Local people collect honey, fish and crabs
You are allowed to cut down trees
There is big demand for fuel and construction in surrounding villages
The cyclone Aila occurred in 2009 and caused flooding, a loss of livelihood, and freshwater contamination which was a struggle for the local people

Question 119

What is mitigation?

Answer 119

Mitigation means reducing the severity of hazards or other problems

Question 120

What is adaptation?

Answer 120

Adaptation means adjusting behaviour to fit the environment. As the environment of the Sundarbans changes (due to climate change and sea level rise), people will need to adapt to it to reduce risks and increase benefits.