Coasts Flashcards

Question

How is wind moved/created?

Answer 1

Wind moves from areas of high pressure to a low pressure.

Answer 2

As air moves across the water, frictional drag disturbs the surface water, forming ripples this begins to create an orbital motion of water particles - as the water nears the coast and more energy is built horizontal movement of water occurs as waves are driven onshore to the beach.

Answer 3

Spring tide | Neap tide.

Answer 4

Spring tides.

Answer 5

During a spring tide, the sun and moon are in alignment and as a result the strength of gravity from both the sun and moon that are both in line works together to create a larger tidal range (there is a bigger high tide and smaller low tide).

Answer 6

In a neap tide, the moon is at a right angle to the sun, so the gravitational pull of the celestial bodies act against each other to create a smaller tidal range (low tides aren't that low and high tides aren't that high)

Answer 7

A greater tidal range caused by a spring tide, tidal currents will be greater and have greater energy, this affects the amount of transpiration, erosion as well as the height and length of the waves.

Answer 8

Day 1: Sun and moon in line to create spring tide Day 7 and a half: Sun and moon are 90 degrees out of place creating a neap tide Day 15: Spring tide occurs when moon is behind earth and sun is in front Day 22 and a half: sun and moon become 90 degrees out of place again creating a neap tide Day 30: Same as day 1.

Answer 9

Rip currents are powerful underwater currents occurring in areas close to the shoreline on some beaches when plunging waves cause a build-up of water at the top of the beach The backwash is forced under the surface due to resistance from breaking waves , forming an underwater current This flows away from the shore more quickly due to beach features, such as a gap in a sandbar, creating a rip current.

Answer 10

Breaker zone -> Surf zone -> Swash zone (and foreshore) -> Backshore (sometimes containing berms).

Answer 11

``` Strong swash Weak backwash More deposition than erosion Low height (under a meter) Long length Low frequency 6 - 9 per minute Low energy Creates gently sloped beaches. ```

Answer 12

``` Weak swash strong backwash Main process is erosion High wave height (more than a meter) Short length High frequency 11 - 16 per minute High energy Creates steeply sloped beaches. ```

Answer 13

In summer, constructive waves dominate but destructive waves dominate in winter Constructive waves may become destructive waves if a storm begins Climate change may increase the storm frequency within the UK Coastal management may affect the type of waves that occur.

Answer 14

The presence of constructive waves causes deposition on the beach, which in turn leads to the beach profile becoming steeper Steeper beaches favour the formation of destructive waves which are then more likely to occur The destructive waves erode the beach , reducing the beach profile and leading to the formation of constructive waves As constructive waves occur more frequently in summer when there are fewer storms, this means that the beach profile is more gentle in summer and steeper during the winter months when destructive waves are more common This should lead to a state of dynamic equilibrium though in reality this may not occur due to external factors such as the wind strength and direction.

Answer 15

Stretches of the Atlantic coast see high energy where the rate of erosion exceeds the rate of deposition, as a result erosional landforms are found in these environments.

Answer 16

These tend to be sandy and estuarine, here the rate of deposition exceeds the rate of erosion, and as a result depositional landforms like beaches, spits and costal plains tend to be found there.

Answer 17

Rivers and estuaries Cliff erosion Offshore sand Bank Biological material

Answer 18

All coasts are divided into natural components called littoral cells (a sub section of the 11 major UK sediment cells) Each cell contains a complete cycle of sedimentation

Answer 19

A costal management tool used to analyse and describe the different sediment inputs and outputs on the coast and is used to predict morphological changes in a coast over time, it is the balance between inputs and outputs of sediment on a stretch of coastline.

Answer 20

Beach erodes during storm that is in equilibrium Sediment forms an offshore bar forcing waves to break over it early, Waves lose energy and dissipate sooner, reducing erosion When storm calms the bar is slowly reworked back into the beach.

Answer 21

Storm breaches a beach that is not in equilibrium A vulnerable area is formed Beach becomes susceptible to blowout and vegetation is removed from beach More erosion occurs because there is less vegetation and more and more vegetation is removed as vegetation becomes more sparse.

Answer 22

``` Cliff retreat Headlands Bays Cliffs Arches Stacks Stumps Wave cut notches Wave cut platforms. ```

Answer 23

``` Cusps Barrier islands Drift aligned beaches Sand dunes Beaches Tombolo's Spits Bars Barrier beaches. ```

Answer 24

``` The weather The type of erosion Type of rock (Googology) Weathering and its extent Arrangement of the rock (the lithology). ```

Answer 25

Hydraulic action and abrasion/corrasion are the most significant types of erosion and bothy of these are exacerbated in storm conditions.

Answer 26

Hard rocks like granite resist erosion much longer than softer sediments like chalk or limestone.

Answer 27

Lithology can include the layering of rock both horizontally and vertically, discordant and concordant, if soft rock is in front of the hard rock it will erode quicker.

Answer 28

When the sediment in waves erodes and scours rock along the tide.

Answer 29

process occurring on, or due to the effect of, the sea.

Answer 30

Marine erosion Marine transportation Marine and aeolian deposition.

Answer 31

``` hydraulic action; Wave quarrying; abrasion/corrasion; attrition; contribution of solution/corrosion cavitation. ```

Answer 32

Hydraulic action = A form of erosion in which air becomes trapped and compressed in joints in the rock or between the breaking wave and the cliff The high pressure causes the cracks to force apart and widen when the wave retreats and the air expands. Over time this causes the rock to fracture At the same time bubbles found within the water may implode under the high pressure creating tiny jets of water that over time erode the rock This erosive process is cavitation.

Answer 33

* wave cut notches/platforms * cracks, caves, arches, stack, stumps * bays and headlands

Answer 34

- when winds are higher, waves have more energy and therefore increasing the rate of hydraulic action - When the tide comes in (high tide) waves have more energy and the speed of erosion by hydraulic action will be increased.

Answer 35

high energy, tall waves hitting the cliff face have the power to enlarge joints and remove large chunks of unconsolidated rock from a cliff in one go, acting like a large digger on the cliff face.

Answer 36

* wave cut notches/platforms * cracks, caves, arches, stack, stumps * bays and headlands.

Answer 37

- when winds are higher, waves have more energy and therefore waves have greater energy increasing the rate of hydraulic action - When the tide comes in (high tide) waves have more energy and the speed of erosion by hydraulic action will be increased.

Answer 38

the process where sediment is moved along the shoreline, causing it to be worn down over time, creating round and smooth surfaces over time.

Answer 39

• wave cut notches/platforms

Answer 40

When tides move in, they pick up bits of sediment from the seabed (a temporary sediment store/sink hurled against the cliffs at high tide, causing the cliffs to be eroded The shape, size, weight and quantity of sediment picked up, as well as the wave speed, affect the erosive power of this process.

Answer 41

* wave cut notches/platforms * cracks, caves, arches, stack, stumps * bays and headlands

Answer 42

Wave action cause rocks and pebbles to hit against each other, wearing each other down and so becoming round and eventually smaller. Attrition is an erosive process within the coastal environment, but has little to no effect on erosion of the coastline itself.

Answer 43

The mildly acidic seawater can cause alkaline rock such as limestone to be eroded and is very similar to the process of carbonation weathering This is a potential link between the carbon cycle, because as global warming leads to increased sea water acidity, the rates of corrosion related erosion could increase.

Answer 44

Traction Saltation Suspension solution?

Answer 45

Large, heavy sediment rolls along the sea bed pushed by currents.

Answer 46

Smaller sediment bounces along the sea bed, being pushed by currents.

Answer 47

Small sediment is carried within the flow of the water.

Answer 48

Dissolved material is carried within the water.

Answer 49

Waves hit the beach at an angle in the direction of the prevailing wind (south westerly winds in the UK). The waves push sediment in this direction and up the beach in the swash Due to gravity, the wave then carries sediment back down the beach in the backwash at a 90 degree angle. This pushes sediment along the beach over time in a zig zag motion.

Answer 50

Deposition occurs when sediment becomes too heavy for the water to carry, or if the wave loses energy High-energy coastlines continue to transport smaller sediment, so larger rocks and shingle are deposited in these environments Low-energy coastlines have much smaller sediment, which is only deposited in these areas where there is a much lower water velocity. Deposition includes gravity settling and flocculation.

Answer 51

A type of deposition in which the waters velocity decreases and subsequently sediment is deposited.

Answer 52

This is an important process in salt and tidal marshes | Clay particles clump together due to chemical attraction and then sink due to their high density.

Answer 53

Deposition that occurs as a result of the wind on the surface of the earth.

Answer 54

Deposition that occurs due to any sea related processes.

Answer 55

Processes occurring the open air or on the earth's surface, including mass movement and weathering.

Answer 56

Biological Physical/mechanical Chemical.

Answer 57

the breakdown or disintegration of rock in situ, leading to the transfer or sediment into the littoral zone, acting as an input most of the time.

Answer 58

any weathering that does not involve any chemical changes.

Answer 59

Salt crystallisation Freeze thaw Wetting and drying

Answer 60

When water enters a crack in a fault due to rain, it freezes in cold weather, when this happens it expands in volume by about 10% The expansion exerts pressure on the rock, causing the crack to widen With continuous freeze thaw, fragments of rock break away over time, collecting at the bottom of the cliff as scree The fragments created here can often be used in costal processes to further increase erosion. For example in 2001, following a cold winter the south coast of England saw serious cliff falls from freeze thaw, mainly affecting porous rocks like chalk at the white cliffs of dover.

Answer 61

When saltwater evaporates, it leaves crystals behind. These grow over time and exert stress onto the rock, similarly to ice The salt can also corrode some rocks, particularly if they contain a high amount of iron.

Answer 62

Rocks undergo series of wetting and drying phases, and many rocks that are high in clay (such as shale) expand when they get wet and contract when they get dry, this can cause them to crack and break up.

Answer 63

the breakdown of rocks that comes as a result of organic activity.

Answer 64

``` Plant roots birds rock boring seaweed acids decaying vegetation. ```

Answer 65

Roots of plants growing into the cracks of rocks, which exerts pressure, Eventually splitting the rocks

Answer 66

Some birds such as Puffins dig burrows into cliffs weakening them.

Answer 67

Many species of clams secrete chemicals that dissolve rocks | many animals also burrow into the ground to make nests

Answer 68

Kelp contains sulphuric acid, which dissolves rock minerals.

Answer 69

Water flows through decaying plants and becomes acidic.

Answer 70

Weathering that involves a chemical reaction or chemical change.

Answer 71

Carbonation Oxidation Solution.

Answer 72

Rainwater absorbs CO2 from the air to create a weak carbonic acid rain reacts with limestone to form calcium bicarbonate, which is then easily dissolved allowing erosion

Answer 73

Rainwater absorbs CO2 from the air to create a weak carbonic acid rain reacts with limestone to form calcium bicarbonate, which is then easily dissolved allowing erosion The cooler the temperature, the more carbon dioxide rainwater absorbs, making carbonation more effective in winter.

Answer 74

The reaction of rock materials with oxygen, when exposed to air, some rocks will become oxidised which in turn increase its volume causing the rock to crack Most common with iron minerals

Answer 75

When rock minerals like rock salt (halite) is dissolved.

Answer 76

movement of material down a slope under the influence of gravity

Answer 77

* Soil creep * Mudflow * Landslide * Rock fall * Slumping/rotational slip/landslip * Runoff * Soilfluction.

Answer 78

a slow form of movement of soil particles downhill, it involves soil particles rising to the surface during wetting or freezing (moving downhill) and then returning back into the surface when it is wetted or frozen once again Soil creep forms shallow terracettes and can be seen occurring through the build-up of soil on walls and the bending of tree trunks (Terracettes = a ridge on a hillside, like the ones at white horses).

Answer 79

An increase in the water content of soil can reduce friction, leading to earth and mud to flow over underlying bedrock , or slippery materials such as clay Mudflows represent a serious threat to life as they can be very fast flowing Water gets trapped within the rock, increasing pore water pressure, which in turn forces water particles apart and leads to slope failure.

Answer 80

Heavy rainfall can reduce friction in cliffs and lead to a landslide It occurs when a block of intact rock moves down the cliff face very quickly along a planar surface (a slide plane) unlike mudflows the moving block of material stays intact and can lead to the build-up` of scree toward the bottom of a slope.

Answer 81

It involves the sudden breaking away of rock fragments at a cliff face It usually occurs on steep cliffs made of resistant rock and often comes as a result of mechanical weathering (mainly freeze thaw weathering) or an earthquake Once broken away the rocks form scree at the bottom of the coast, acting as a temporary store at a costal system.

Answer 82

occurs on surfaces that are curved rather than flat or steep They commonly occur on areas of weak clays or sands, often when permeable rocks overtop impermeable rock which causes a build-up of pore water pressure The land collapses under its own weight, due to increased PWP (Pore water pressure) This creates a terraced appearance.

Answer 83

when overland flow occurs down a slope or cliff face, small particles are moved downslope into the littoral zone, potentially creating an input into the sediment cell Runoff can also be responsible for increasing pollution in coastal areas.

Answer 84

Soilfluction is specific to cold, periglacial environments, where, in the summer the surface layer of the soil thaws out, becoming extremely saturated as the permafrost beneath it cannot be infiltrated As a result the active layer (sodden surface layer) is moved slowly downhill as a result of heave and flow This process can lead to the formation of Soilfluction lobes.

Answer 85

Temperature and climate can influence the prominence of weathering In colder climates, mechanical weathering is more common, whereas in warmer climates, chemical weathering is more common.

Answer 86

There is more of U (Eustatic) than than there is of I (Isotatic)

Answer 87

Sea level change that occurs globally, coming as a result of changes in the shape of the ocean basin, changes in the volume of water or the size of water itself.

Answer 88

Due to increased volumes of water as a result of accumulation of water in ice or the release of it during an interglacial period Increases in temperature outside cause thermal expansion, which increases the size of water particles themselves (particles move around faster and exert more pressure within the water If there is tectonic uplift in the oceans the capacity of the worlds ocean basins will increase or decrease.

Answer 89

Isostatic sea level change is always local and comes as a result of land rising and falling - rather than the sea.

Answer 90

Isostatic sea level change could be due to post-glacial adjustment glaciers weigh down the land beneath known as glacial compression, when the ice melts the land slowly rises back upwards over a long period of time known as post glacial or isostatic rebound For example, post-glacial adjustment for the UK after the Ice Age has caused Southern England to subside around 1mm per year and Scotland to rebound and increase around 1.55mm per year ``` Tectonic activity (such as earthquakes and volcanic eruptions) may cause land subsidence, therefore causing isostatic sea level increase. Landslides and avalanches can also cause additional sediment to enter a costal system, adding sediment to the sea floor. ```

Answer 91

2004 Boxing day Tsunami.

Answer 92

On December 26 2004, a magnitude 9.0-9.3 occurred in the Indian ocean Epicentre was west of northern Sumatra, Indonesia 300,000 people died Part of the earths crust by the city of banda aceh sunk permanently flooding parts of it.

Answer 93

caused 1600km of fault line to slip 15m along the subduction zone of the burma plate 30km3 of water was displaced, causing the Tsunami Realised the seabed of the Indian ocean causing a global sea level rise increase of 0.01 mm Tectonic uplift by the epicentre in Sumatra caused the seabed to rise several meters, causing the city of Banda Aceh and other nearby places to flood.

Answer 94

The sea level has risen by about 130m since the last glacial maximum 21,000 years ago

Answer 95

Sea level plateaued around 7,000 years ago only increasing very slowly, only rising by about 4m to where it is today.

Answer 96

a coast where landforms have been revealed due to falling sea levels (the landforms are merging out of the water).

Answer 97

Wave beaches Former wave cut platforms relic cliffs, stacks and arches.

Answer 98

In the North where post glacial rebound has meant sea level has fallen leading to relic features emerging out of the sea Particularly on the Scottish Isle of Arran on the west coast of Scotland.

Answer 99

Coastlines of submergence as a result of flooding in the area (landforms are submerged underwater) mostly due to Eustatic (but sometimes isostatic) sea level change where land is submerged underwater.

Answer 100

Rias Fjords Dalmatian coasts

Answer 101

A river valley that is v shaped that has become flooded due to sea level rise on the coast, these are predominantly found in south west England.

Answer 102

The Kingsbridge estuary In south Hams, Devon which is 8.6km in length where the town of Salcombe has been built.

Answer 103

A submerged U shaped valley that are formed when deep glacial troughs that are long and steep sided are flooded, Fjords tend to be much deeper inland than Rias, They are found in Norway, Chile and new Zealand.

Answer 104

Milford sound in the south west of New Zealand's south island, the highest mountain Mitre peak is 1683m tall and the Fjord has a depth of 291m

Answer 105

Occur when ridges and valleys that run parallel to the coast are submerged due to sea level rise that create a series of offshore islands that runs parallel to the coast.

Answer 106

They are only found in Croatia in Dalmatia, from which they derive their name from.

Answer 107

Kings cave beach on the Isle of Arran on the west coast of Scotland near the village of blackwater foot The raised beach is 8m high and formed around 6,000 years ago

Answer 108

The old man of Hoy on the Orkney islands, found in rackwick bay. It is 449ft high, 137m

Answer 109

Around 3,000 years ago.

Answer 110

Between 1900 and 1990 studies show that sea level rose between 1.2 millimeters and 1.7 1993-2000 average yearly sea level rise was around 3.2 mm

Answer 111

Around 0.85%

Answer 112

Anywhere from 30cm to 1m varying from place to place.

Answer 113

45% associated with melting glaciers (21% glacier, 16% Greenland, 8% Antarctica) 38% associated with thermal expansion.

Answer 114

It is located at the point where the international date line and equator meet, it is a pacific island nation far east of the Solomon islands.

Answer 115

It is made up of 33 low lying islands, with low lying sand and mangrove atolls making up lots of the islands, Most islands are less than a metre above sea level with many of its islands at risk of disappearing in the next fifty years. average elevation of 2m

Answer 116

1.2 cm, more than 4 x the global average.

Answer 117

- President Anote Tong was forced to purchase 20km2 of land from the nearby Fiji - the rising sea level contaminated the ground water (salinization) affecting its ability to grow crops and freshwater drinking sources (created a positive feedback cycle with the mangroves which were protecting them from flooding - The land purchased from Fiji will be used for agricultural and fishing practices to supply the nations dwindling food supplies - The government has launched a 'migration with dignity scheme' with residents being given the choice to migrate to nearby countries like NZ - If the islands become fully submerged Kiribati's population will become some of the first environmental refugees.

Answer 118

Since 1880 and the industrial revolution, sea levels have increased by around 2.35 meters.

Answer 119

Sea level is measured by two main methods: tide gauges and satellite altimeters.

Answer 120

Tide gauge stations from around the world have measured the daily high and low tides for more than a century, using a variety of manual and automatic sensors Using data from scores of stations around the world, scientists can calculate a global average and adjust it for seasonal differences.

Answer 121

Satellite altimeters measure the ocean surface height (sea level) by measuring the time it takes a radar pulse to make a round-trip from the satellite to the sea surface and back This data can act as proof of sea level rise.

Answer 122

- Sea level rise depends on human activity, it is reliant on how much co2 and other greenhouse gasses are released into the atmosphere, and that in itself is currently uncertain - The climate is highly complex and it is not certain how much of an effect more climate change will cause as well as the significance of many positive feedback loops on the speed at which sea level rise occurs - As the technology improves and sea level rise is understood, sea level rise forecasts become more accurate and will change over time based on human GHG emissions - Sea level rise is different in many parts of the world, so different groups may be using data from different locations that will all experience a different level of sea rise, due to local – isostatic – sea level rise factors.

Answer 123

: In Europe the sea level is expected to rise the most in the Mediterranean, specifically the North African and Turkish coast – here it is expected to rise by around 5-10mm per year compared to the rest of the continent which should see sea level rise by around 2mm per year The greatest sea level rise is likely to occur in the south China sea around Indonesia, Malaysia and other nearby countries like Thailand Here sea level could rise by more than 20mm a year which would have devastating impacts on the costal agricultural plains in the region Much of the South Asian coast as well is believed to see sea level rise of 5-10mm per year, all the way from the Pakistan coast to North Korea and the North of Japan All parts of Southern Mainland Asia will see a rise like this with the exception of the area around Laos, Cambodia, Thailand and Vietnam which will see sea levels increased by more than 20mm a year This could have massive ramifications as it’s believed 157 million people here live below 2m above sea level it is also a highly important agriculturally intensive land, that is crucial for the worlds food supply.

Answer 124

This Rapid rise is associated to (according to the IPCC) the fact that the Indian ocean is warming faster than any other ocean, this means that thermal expansion is occurring there at a rate greater than anywhere else and subsequently the sea is rising fastest The sunda shelf in south East Asia (Sundaland is a term for the region of South-eastern Asia which encompasses these areas of the Asian continental shelf that were exposed during the last ice age) is another reason for rapid sea level rise in south East Asia The sea above the Sunda shelf is warm due to its shallow depth and position along the equator and as a result thermal expansion has caused sea levels there to rise faster than anywhere else.

Answer 125

The both thermal expansion and the melting of glaciers can be mitigated to an extent if Humans cut back on Carbon emissions so the greenhouse effect creates less of an impact. Tectonic changes to the oceans drainage basin cannot be changed as tectonic activity is completely out of human control.

Answer 126

The Sundarbans is a coastal zone occupying the world's largest delta that extends over 10,000 km2 of southern Bangladesh and India on the Bay of Bengal.

Answer 127

The delta is formed from the sediment deposited by three of the world's great rivers, the Ganges, Brahmaputra and Meghna.

Answer 128

The key natural ecosystems of the Sundarbans are mangrove forests and swamps.

Answer 129

A dense, well-developed, network of interconnecting river channels flows across the clay and silt deposits Traditionally the location of the network of main channels remained relatively static due to the silts and clays being quite resistant to erosion The larger channels are generally straight and can become up to two or more kilometres wide, flowing generally north to south due to the strong tidal currents.

Answer 130

The non-cohesive sediments like sand are washed out of the delta and deposited on banks, where the strong south-westerly monsoon winds then blow them into large ranges of sand dunes With the protection of the dunes, finer silts washed into the bay are deposited, where wave action then adds and shapes further deposits of sand to form new islands Vegetation establishes itself and eventually, if the natural vegetation succession can occur, the dense mangrove forests, where species like the endangered Royal Bengal Tiger can develop However, the equilibrium of the natural processes that exist here is very delicate and further human activity it may be jeopardising its very existence.

Answer 131

The mangrove forests of the Sundarbans are crucial for the wildlife and people living there, providing economic and environmental opportunities, only if managed sustainably Despite the wealth and service potential many outside and inside Bangladesh view this area as uninhabitable.

Answer 132

Despite the variety of processes at the Sundarbans, costal erosion is not the main threat due to the strength of the clays and silts (they are resistant to erosion).

Answer 133

* Fuel – Charcoal and firewood * Construction materials – timber, poles, thatch * Fishing materials – poison and floats * Household items – furniture, glue and wax * Food and drink – leaves, fruits honey, cooking oil, alcohol, vinegar and fish * Textiles – furs and skins, synthetic fibres and tannins and dyes * Medicines * Paper.

Answer 134

* Protection services – flooding, erosion, cyclones * Provision of: nursery grounds, breeding grounds, fishing grounds and costal livelihoods * Maintenance of the environment * Value to: culture, spiritual, religion, education and science, recreation and leisure and heritage.

Answer 135

- Coastal flooding - Cyclones - High salinity levels in soils - Instability of the islands - Accessibility and remoteness - Deadly wildlife (Tigers) - Over exploitation of valuable resources from vulnerable costal habitats - Conversion of wetlands into intensive agriculture and settlements - Destructive fishing techniques - Lack of knowledge on the environmental and economic significance of the region - Resource – use conflicts - Lack of awareness on costal issues by decision makers.

Answer 136

Despite the plethora of challenges many live successful lives in the Sundarbans by working with nature rather than against it Mitigation Resilience.

Answer 137

The wealth of local goods in the area have allowed local populations to survive, the mangrove forests and dunes themselves offer protection from: storm winds, floods, tsunamis and costal erosion.

Answer 138

It’s believed 30 trees per 0.01 hectares can reduce the severity of a tsunami by 90% It’s also thought that one hectare of mangrove forest is worth $12,000 per year and as a result (unlike many parts of Bangladesh) it offers resilience against poverty and provides sustainable development for those looking to move there.

Answer 139

- The ever present threat of natural disaster in the Sundarbans has meant there has been significant investment in the area (roads, telecommunications, schools, hospitals, cyclone shelters, flood protection and tube wells) which mitigate the risks they face - Many communities of the Sundarbans also have good levels of social capital from the legal frameworks and services provided by a number of formal government and NGO organisations, alongside traditional laws, tenets and social sanctions that communities have used for generations to manage their use of the region - There is also economic value to the resources of the area and together with financial resources like access to micro-credit; most Sundarbans communities have a greater economic safety net than other vulnerable groups in Bangladesh.

Answer 140

In recent decades the level of resilience provided by these livelihood assets may be decreasing as poverty and marginalisation of some coastal communities increases due to: - shrinking of the open access resources - increasing deaths by tigers (if wives are widowed they can often face very limited opportunities in this male-dominated society, especially as many marry very young before completing their formal education) - Degradation of ecosystems - Conflicts over land usage - corruption of both local and national political institutions However, it is almost certain that Climate change will be the most significant threat the people of the Sundarbans face.

Answer 141

* Increased frequency and intensity of floods - * Flood waters remaining for longer - * Permeant embankments built by the shrimping industry are encouraging the deposition of silt which is raising water levels in the rivers – * Rising temperatures are leading to the increased salinity of soil - * Increased fertiliser and pesticide usage is worsening soil quality * Changes to seasonal patterns of rainfall.

Answer 142

• Grassroots NGOs run education programmes to encourage farmers to return to more traditional ecologically-friendly methods • NGOs provide education and training about community level preparation for natural disasters — planning and preparation can significantly mitigate the impacts of natural disasters • USAID is training communities to become more resilient to future climate shocks, 30,000 have been taught improved agricultural techniques • Relaunch of the policy to build multipurpose cyclone shelters equipped with communication equipment and megaphones, which also serve as primary school facilities (this comes after many were built in the 1970’s and many have been neglected since) • New salt resistant rice varieties that can survive being submerged in sea water for up to 2 weeks • NGO’s building latrines on higher grounds and the education of communities on waterborne diseases and sanitation • Installing storage tanks for rainwater in areas that are most at risk of inundation from salt water • Distributing water tight containers to store important belongings and papers during floods .

Answer 143

``` South Hallsands (submerged) North Hallsands Beesands Sunny dale Torcross ```

Answer 144

South Hallsands = Lost to the sea after removal of sediment from scerries bank, built on a wave cut platform North Hallsands = Rip Rap and rock armour, prospect house

Answer 145

South Hallsands = Lost to the sea after removal of sediment from scerries bank, built on a wave cut platform North Hallsands = Rip Rap and rock armour, prospect house Beesands = Rock armour and sea wall Sunny Dale = Gabions that are privately owned that have led to Coastal squeeze Torcross = Recurved sea wall and rock armour as well as beach nourshment schemes by Operation tiger monument to protect important A379 transport link

Answer 146

At GCSE we do Hard vs Soft engineering at A level we look at Traditional vs holistic management techniques.

Answer 147

Half the world lives withtin 60km of the coast 75% of large cities are on the coast Coastal areas are under huge and increasing pressure for development ((Costal squeeze (population type)) Leading to environmental damage and habitat destruction.

Answer 148

Sustainable development goals - by 2030, strengthen resillience and adaptive capacity to climate related disasters and natural disasters in all countries.

Answer 149

Direct action on preventing erosion or flooding on a short section of a coast, focusing on one limited stretch of coast rather than looking at the coastal system as a whole.

Answer 150

Sustainable, long term approaches considering the entire coastal zone, with the goal being to finding a balance between ecological and human needs, with adaptation being a viable option.

Answer 151

Almost 4 million.

Answer 152

the process by which waves turn and lose energy around a headland on uneven coastlines The wave energy is focussed on the headlands, creating erosive features in these areas The energy is dissipated in bays leading to the formation of features associated with lower energy environments such as beaches.

Answer 153

Beaches that run at an angle to the approaching wave front, here drift aligned sediment is deposited along the coast within the process of longshore drift This can often lead to the formation of a spit.

Answer 154

Sediment size will decrease the further down the beach we go, as finer particles are more likely to be carried further and become more rounded as they go.

Answer 155

The wave front approaches parallel to coast so there is limited longshore drift and Sediment doesn’t travel up the beach far

Answer 156

``` Spits (Simple and compound) Bars Tombolo Beaches Barrier islands Barrier Beaches Sand dunes Estuarine mudflats and saltmarshes. ```

Answer 157

Cliffs Wave cut notches Wave cut platforms Caves, arches, stacks, stumps.

Answer 158

Spits - A spit is a long narrow strip of land which is formed due to deposition Longshore drift occurs along the coast line but as the waves lose energy (normally due to going into a sheltered area such as behind a headland) they deposit their sediment Over time this creates a spit Periodically, the prevailing wind will change direction and tidal power causing a recurved hook to appear Over time, the sheltered area behind means that a saltmarsh as energy there is low, as a result a mudflat is formed Then, alluvium dries creating a salt marsh where vegetation can begin to grow Plant succession can begin to occur stabilising the spit and forming a more developed salt marsh The length of a spit is influenced by surrounding currents or rivers.

Answer 159

A spit that has multiple barbs along the spit.

Answer 160

Bars - A spit which, over time, crosses a bay and links up two sections of coast.

Answer 161

When a spit connects with an island off the coast, it may be submerged at high tide.

Answer 162

``` The curvature of the beach Wave energy type of wave Direction of prevailing wind Currents (Longitudinal current) ```

Answer 163

Hurst castle spit in Hampshire

Answer 164

Chesil beach spit, linking mainland Dorset to the isle of Portland.

Answer 165

The Arabat spit in the sea of Azov, Crimea - it is the worlds longest spit at 70 miles long.

Answer 166

When waves approach a gently sloping coast friction between waves and the sea bed cause the waves to break up at a distance from the coast, Over time more material is deposited and built up away from the coast, forming the offshore bar which is a ridge of sand The offshore bar can partially or completely cut off a piece of land to form a lagoon Offshore bars are sediment sinks but can sometimes be sediment sources as the waves don’t have enough energy to carry the sediment to shore. They can be formed as the wave breaks early, scouring the seabed and instantly depositing its sediment as a loose-sediment offshore bar.

Answer 167

When a spit becomes a bar when it creates a barrier beach Barrier beaches can trap water behind them to form lagoons or freshwater lakes (Like at Slapton Ley) Barrier beaches on the south coast of England have formed as a result of rising sea level after the last glacial period Sediment that was in the English channel has been deposited on barrier beaches to build them up.

Answer 168

Slapton Ley 5km long (Freshwater lake) | Chesil beach Weymouth 18 miles long

Answer 169

Concordant coastlines are where the rock strata run parallel to the coast.

Answer 170

This is where the rock strata run perpendicular to the sea, which can create successions of headlands and bays; less resistant rocks are eroded faster than the more resistant rocks, which leads to the formation of bays.

Answer 171

Where a beach becomes separated from the mainland, common in areas with low tidal ranges and gently sloping coastlines, found in the Netherlands, and the south Texas coast.

Answer 172

Dry sand is blown onshore during low tide and sand is initially trapped as the back of the beach by debris, and over hundreds of years vegetation or dune succession takes place Small embryo dunes form and as they stabilise (allowing pioneer species to develop on them) their pH decreases and Hummus level increases The pioneer species that grown on the fore dunes like sea rocket and couch grass have become adapted to cope with very dry and salty conditions, not only do they bind the soil together with their roots, but when they die they they add organic matter to the developing dunes As pioneer species evolve, they bind the soil together creating larger fore dunes where marram grass - a plant with very long roots to reach water - grows which further binds the dune together, Depressions and slacks form between dunes form just above the water table where aquatic plants can grow As the environment changes over time, low shrubs begin to form on grey dunes, and on the mature (fully matured dunes) Oak and pine trees and gorse grows, here pH is at is lowest and hummus is at its highest this is known as the climactic climax community.

Answer 173

Sand dunes occur when prevailing winds blow sediment to the back of the beach and therefore the formation of dunes requires large quantities of sand and a large tidal range This allows the sand to dry, so that it is light enough to be picked up and carried by the wind to the back of the beach Frequent and strong onshore winds are also necessary

Answer 174

``` Embryo dune Fore dune Yellow dune Grey dunes Dune slacks Mature dunes ```

Answer 175

Soil pH decreases (it is highest near the sea as sea water is alkaline) Hummus levels increase the further back you go (because amount of organic matter is greatest away from the sea.

Answer 176

Humus is dark, organic material that forms in soil when plant and animal matter decays.

Answer 177

Sand dunes at Studland bay Dorset, with more than 75 hectares, Studland is the largest area of dune heath on the South Coast

Answer 178

Beaches are made up from eroded material that has been transported from elsewhere and then deposited by the sea For this to occur, waves must have limited energy, so beaches often form in sheltered areas like bays Constructive waves build up beaches as they have a strong swash and a weak backwash Sandy beaches are usually found in bays where the water is shallow and the waves have less energy Pebble beaches often form where cliffs are being eroded, and where there are higher energy waves.

Answer 179

at a coastline where the lithology is layered vertically and directed to the sea, the sea attacks the base of the cliff with hydraulic action causing a wave cut notch, over time the notch grows and grows causing the cliff to become a large overhang At the same time the top of the cliff is weakened through sub aerial weathering over time the cliff can no longer remain an overhang and collapses The backwash carries the collapsed sediment out to see leaving behind a sloping rocky platform behind as the cliff retreats usually visible at low tide the cliff collapses time and time again, extending the size of the wave cut platform.

Answer 180

Geology - The substance of rock affects the rate of erosion, the lithology does as well (it will determine if a wave cut notch will form or whole cliff erosion) Wave energy - Whether there are constructive or constructive waves, as wave cut notches and platforms only occur at high energy coastlines Tides - High tidal ranges could lead to tidal scour.

Answer 181

Headlands from on a discordant coastline where alternating bands of hard and soft rock perpendicular to the ocean erode and form bays and headlands Because of wave refraction, destructive waves focus their energy all on the sides of the coast, causing the headland to slowly erode over time In doing so cracks and faults within the inter tidal zone become exposed through hydraulic action which causes the crack to widen They are further widened by weathering and crystallisation and further erosion through abrasion and hydraulic action is focused on the sides of the fault due to wave refraction, causing the crack to widen to form a cave eventually the waves break through the cave forming an arch Biological weathering occurs at the top of the arch combined with the forces of gravity and further weakening and expansion of the arch mean that the arch collapses forming a single isolated stack Hydraulic action weakens the base of the stack before it too collapses into the sea causing a stump which may only be visible at low tide.

Answer 182

Dancing ledge, Dorset near the village of Langton Matravers.

Answer 183

Geology Lithology Wave energy / type of wave.

Answer 184

``` Cave = Merlin's cave in tintagel, Cornwall Arch = durdle door, Lulworth, Dorset Stack = Old oman of hoy, orkney islands, Rackwick bay Stump = Old harry rocks, swanage bay, Dorset. ```

Answer 185

- Sheltered areas where deposition occurs - Where saline and freshwater meet, the rising tides create a buffer to river flow leading to deposition - Where there are no strong tides and currents, low velocities mean the sediment deposited is mud

Answer 186

- Mud is deposited close to the high tide line on a low energy beach, here flocculation occurs and tiny sediments stick together and their combined mass makes them sink to the seabed - Pioneer plants such as Eelgrass and Cordgrass start to form in the transition zone, these can tolerate the inundation of saline water as well as supporting the deposition of more sediment - Gradually mud levels rise above high tide and and a more developed saltmarsh, with plants that no longer need to be adapted to saline conditions Soil conditions improve and vegetation succession continues to form a meadow, the ecosystem in a salt marsh is often known as a halosere

Answer 187

Beach nourishment = The addition of sand or pebbles to an existing beach to make it higher and/or wider The sediment involved in Beach nourishment is typically dredged from a nearby seabed or nearby beach It helps rebuild a beach, reducing the rate of erosion on the cliffs, acting as a natural defence to both erosion and flooding as well as opening the possibility to bring in increased numbers of tourists. Beach nourishment aims to minimise the impacts of longshore drift band the rate at which the coast is eroded and flooded by creating a natural barrier by removing sediment from one area of a sediment cell and putting it in a more vulnerable/critical location.

Answer 188

Slapton sands outside the operation tiger war memorial. | Swanage bay

Answer 189

Costs around £3000/m2

Answer 190

Relatively cheap and easy to maintain Looks natural and blends in (usually) to the surrounding area Increasing tourist potential by creating a beach

Answer 191

Needs constant maintenance and looking after Can disrupt other costal processes (could be similar consequences to the removal of sediment in skerries bank in start bay) If sediment is taken from other beaches, those beaches become weakened and vulnerable ; it does not mitigate the problem entirely it can just move it elsewhere

Answer 192

Cliff regrading and drainage = Cliff regrading involves reducing the angle of a beach/cliff to help stabilise it. A steep cliff is typically more vulnerable to collapse, therefore the lower the gradient of a cliff the less vulnerable it is to erosion. Drainage involves the removal of water from an area to prevent landslides and slumping – it also involves the re vegetation of areas. By reducing the angle of a cliff, the slope is more structurally strong, making it less vulnerable to the processes of hydraulic action and corrosion. By draining the cliff, the slope becomes less heavy and lubricated, reducing the risk of mass movement and freeze thaw weathering. Cliff regrading and drainage reduces the frequency of mass movement on the coast and slows processes like hydraulic action.

Answer 193

Highcliffe in east Dorset (near Christchurch, Bournemouth) where the cliffs have been regraded and drained to reduce erosion to prevent the nearby Highcliffe castle from falling into the sea.

Answer 194

Can cost as much as £1 million per every 100m. But this figure can vary greatly depending on the size and type of rock and size of coast.

Answer 195

Can be very effective on clay and other loose rock where many other strategies may not be effective Drainage is usually cost effective Reduces the level of water content in cliffs which most other techniques do not do (prevents cliffs from oversaturating and collapsing.)

Answer 196

May look unnatural Cliff may collapse during the process, or because the cliff is drier it could lead to rockfalls, creating an additional hazard. Regrading involves the retreat of a cliff, effectively eroding it (carrying out what it is supposed to prevent) Can be very disruptive and loud during construction.

Answer 197

Dune stabilisation = the planting of Marram grass on dunes to help bind them and protect the land behind them. Areas are also often fenced off to keep people off the Newley planted dunes. Stabilisation increases the dunes' ability to prevent erosion from wind and water by making them more bound by roots The strategy can somewhat prevent longshore drift, but mainly absorbs wave energy, preventing it from eroding the cost (also can act as a natural flood defence)

Answer 198

Port Einon, Pembrokeshire

Answer 199

Costs around £2 to £20 per meter

Answer 200

The coast retains a natural look Provides important costal wildlife habitats for many different species Relatively cheap Sustainable Requires little long-term maintenance once plants are planted and grown

Answer 201

The planting of marram grass is time consuming The plants themselves (and roots) need time to grow and therefore won't noticeably affect costal rates of erosion quickly. People may respond negatively from being barred away from certain area if some are fenced off

Answer 202

Timber rock structures built at right angles to the coast. They trap sediment being moved along the coast by littoral drift – building up the beach. It works with natural processes to build up the beach and protects the land behind it.

Answer 203

it does starve the beaches further up the coast of fresh sediment because they interrupt littoral drift, often leading to increased erosion elsewhere. They can look unattractive as they are unnatural.

Answer 204

Swanage bay, Dorset

Answer 205

£5000 to £10,000 each (at 200 metre intervals) 30-50 years Wooden groynes may be less like 10-25 years

Answer 206

A sea wall is a protective shield to the coast made of steel, concrete and stone. Sea walls prevent the erosion of the coast by reflecting waves or blocking the movement of sediment along the coastline. Sea walls prevent the erosion of cliffs and movement of sediment that would occur as a result of erosion.

Answer 207

Ugly Unnatural Expensive Large disruption during construction

Answer 208

Materials like old tyres/ cement can be placed on the floor of the ocean in the intertidal zone.If this is parallel to the coast then it causes waves to break offshore, and therefore reduces the amount of energy the wave has when it reaches the coastline, therefore there is less erosion. By stopping storm waves reaching the coastline it allows the wider beach to develop.

Answer 209

Natural ecosystem is only partially disturbed Dunes can stabilise onshore New habitats could be made Relatively cheap compared to other strategies

Answer 210

Hazards in navigation If visible at low tide can look ugly Disrupt some uses of the beach like jet skis Difficult to install

Answer 211

Sea Palling in Norfolk has offshore reefs, it is one of the only coastlines that does

Answer 212

Tidal barrages are dam like structure however instead of stopping the movement of water, the water can infact move in and out of the river or bay. These tidal barrages can be found in the form of roads or bridges, the purpose is to control and reduce the tidal force. They are also a source of power as they generate hydro power.

Answer 213

- can help prevent low level flooding in certain areas - a road can be installed and therefore these can have multiple benefits - produce a reliable source of energy

Answer 214

- very costly - lengthen periods of high and low tides, this has a great effect on the eustarine systems - shorten tidal range

Answer 215

La Rance Tidal Barrage in France was built 1963, it is one of the most successful barrages in the world.

Answer 216

Tidal barrages generate a reliable source of energy that is essentially carbon free. They are also very long lasting compared to lots of other strategies.

Answer 217

Total cost of the barrage in France was roughly 620 million Francs which is roughly 94.5 million Euros.

Answer 218

This is where very large boulders are placed on a shoreline interlocking one another, as it is allowing for protection against erosion, specifically in-front of property. However, it can be on the more expensive side. Rock Armour works by absorbing and deflecting wave impact and energy before they are able to reach any coastline structure. The main processes that it aims to prevent/slow down are scouring, wave and ice erosion processes. Mainly the breakdown of natural defences such as sand dunes, would mean that Rock armour may have to be implemented to protect a specifically important section of the coast. The main source of energy that this method aims to dissipate, or reduce its impact is wave energy, as the rocks disperse the initial impact of the waves.

Answer 219

A disadvantage of rock armour would be the price, and it’s aesthetic due to the very large size and quantity required for it to be effective.

Answer 220

A location within the UK that has rock armour in place would be Slapton sands (Torcross).

Answer 221

``` They are cost effective. They are highly durable to weathering. They dissipate energy very well. They can come in a range of sizes, which means they can be put in at almost any coastline. They are easy to install. ```

Answer 222

They are sloping structures built on embankments and shorelines or in front of sea walls to help to dissipate wave energy and reduce coastal erosion They are often constructed as permeable structures; this allows them to absorb the maximum amount of both wave energy and minimising wave run up. There main functions are to protect the shoreline from erosion and storm surge flooding events. The main issue with revetments is that they have a high tendency to degrade the beach, and therefore are only put in at points that are hyper-exposed to erosion along the coastline. The primary sources of energy that they look to prevent are wave energy, and tidal energy, as higher tides can often create more destructive waves/ hit higher areas within the rocks. There are two specific types of revetments, exposed and buried. Buried are usually used as a part of soft engineering strategies to add more protection against erosion without appearing man-made and out of place.

Answer 223

Happisburgh, Norfolk

Answer 224

A coastal ecosystem found between land and open salt water that is regularly flooded by tides. Created when mud and silt are deposited along a sheltered part of the coastline such as the inside of a spit. This is because rates of deposition are greater than transpiration due to lack of energy in waves. The marshland also limits the area in which waves can reach preventing flooding. The marshlands can be created by encouraging the growth of marshland vegetation such as glassworts.

Answer 225

Holderness Louisiana coast Along the Bristol channel

Answer 226

Look natural Provide a biological ecosystem Sequester climate change therefore helping the climate crisis

Answer 227

Very expensive to maintain and create

Answer 228

Offshore breakwaters are shore-parallel lines of rocks and boulders designed to reduce the wave energy that reaches the beach. The rocks break the waves early causing them to lose energy which reduces the erosion on the beach as well as preventing littoral drift. The waves don’t carry sediment up the beach as far, therefore preventing littoral drift. Low energy waves causes increased deposition and for a larger beach to form. This is effective if the waves aren't taller than the defence and so strong winds, high tide and wave energy will decrease the effectiveness of the defence.

Answer 229

Wallasey has the first offshore breakwater in Britain constructed for coastal defence (1981), in Merseyside, Liverpool

Answer 230

They protect the shoreline by absorbing wave energy, which reduces erosion, and by changing wave direction, which reduces longshore drift.

Answer 231

Low littoral drift may negatively affect other places down the coast. Can be a problem for small boats which may break on land just below the water. Can create currents behind the breakwater which is a hazard for swimmers

Answer 232

Creates saltmarsh which can provide a habitat for animals No construction cost Natural defence against erosion and flooding

Answer 233

Initial construction cost is nothing to the local authorities Landowners need to be compensated - this can cost between £5,000 - €10,000 per hectare Is against the point of coatal management

Answer 234

Abbot Hall Farm, Essex First retreat site 8,000 square metres

Answer 235

Gabions are metal cages containing rocks, usually constructed at the base of a cliff to absorb wave energy and reduce erosion. They reduce the speed and energy of the water by forcing the water through the small gaps in the cage. This reduces erosion to the slope behind it whilst providing good drainage and permeability to water. The effectiveness will be reduced by wind speed and fetch which will in turn increase the waves energy and erosion potential. Tides will make the biggest difference as if low tide doesn’t reach the gabions, then the cliff won't be affected.

Answer 236

Found in many parts of the English coastline such as Seaton and Slapton Sands in South Devon

Answer 237

Cheap at only £100 per square metre | Reduces wave energy and prevents erosion at the top of the beach

Answer 238

``` Short lifespan of only 5 to 10 years Easily destroyed in storms When destroyed metal wires can become dangerous and so need constant management. Looks unnatural, especially when rusted. Can't prevent against flooding. ```

Answer 239

The cooler the temperature, the more carbon dioxide rainwater absorbs, making carbonation more effective in winter.

Answer 240

Mitigation can restrict impacts of something and therefore can reduce the level of adaptations required by communities and nations, but there is a significant lag time between mitigation activities and their effects, so it may be many years before adaptational requirements are reduced.