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Contents

Introduction v

The natural environment (Section A) Chapter 1: River environments 1 Chapter 2: Coastal environments 11 Chapter 3: Hazardous environments 21

People and their environments (Section B) Chapter 4: Economic activity and energy 31 Chapter 5: Ecosystems and rural environments 41 Chapter 6: Urban environments 50

Global issues (Section D) Chapter 7: Fragile environments 60 Chapter 8: Globalisation and migration 71 Chapter 9: Development and human welfare 81 Contents Preparing for the exam 91 Glossary  Sample 95 Index 99

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Geog_Rev_Guide-5thProof.indb 3 22/01/2013 13:29 Chapter 2: Coastal environments The as a system The coast is an open system. For example, sediment comes into the system (input) from a . Waves transport the sediment or it is stored in or . Sediment may be lost to the coastal system if it moves into the open sea (output).

Coastal processes are divided into marine processes (waves) and sub-aerial processes ( and mass movement).

Waves and and deposition

Constructive waves Destructive waves weak tall waves with short long wavelength strong swash shallow wavelength gradient steep gradient waves waves

h sh as wa ackw ack d) ak b g b de we ron ero st ach built up by (be deposition of material brought up in wash

Figure 2.1 Constructive and destructive waves

Constructive waves build the beach by deposition. Destructive waves erode the beach. Their backwash Their swash is stronger than their backwash so they is stronger than their swash, so they drag material carry material up the beach and deposit it there. down the beach and into the sea.

Destructive waves are responsible for most of the erosion along a coast. Four processes are involved: 1. hydraulic action – the power of the waves hitting the coast

2. abrasion – waves pick up stones and hurl them at the coast (Section A) environment The natural 3. corrosion – sea water gradually dissolves some rock components 4. attrition – material carried by waves bumps against other material and is worn smaller and smoother. • Erosion at the coast is speeded upSample by weathering: physical, chemical and biological. • Mass movement also provides material for wave erosion – rock falls, slumps and land slides. Waves and transportation

beach backwash

swash

t n o fr ve sea TOP TIP ✓ a w wind direction Make sure you can draw and annotate your own version of a longshore drift diagram Figure 2.2 Waves move material along the by longshore drift Copyright Pearson Education 11

Geog_Rev_Guide-5thProof.indb 11 22/01/2013 13:29 Coastal : erosional landforms TOP TIP ✓ and bays Make sure you know a case study of two geologically N contrasting coastlines. A soft rock – clays, common choice is between a , where the rock outcrops run parallel to the sea, and a where the rocks hard rock – chalk outcrop at right angles to the sea, forming headlands and Less resistant bays. rocks are worn away to form bays soft rock – clays, sands TOP TIP ✓ Resistant rocks Make sure you know how the stand out as following erosional landforms headlands hard rock – are formed: headlands and bays, cliffs, wave-cut platforms, 0 2 km , , stacks and stumps. Figure 2.3 Headlands and bays result when a coastline has bands of more and less resistant rock Cliffs and wave-cut platforms

overhang original cli line cli overhang high tide high tide water level low tide low tide sea sea

wave-cut notch wave-cut notch rocky wave-cut

(Section A) environment The natural platform Figure 2.4 The formation of cliffs and wave-cut platforms Caves, arches, stacks and stumps PRACTICAL SKILLS 1. Large crack, opened up by hydraulic action You can revise and practise Sampleyour skills at the same time 3. The becomes larger by drawing annotated 5. The is eroded and collapses sketches based on photos of coastal erosional landforms.

7. The is eroded forming a stump Direction of retreat

2. The crack grows into a 4. The cave breaks through 6. This leaves a tall cave by hydraulic action the headland forming a rock stack and abrasion 12 Figure 2.5 How caves, arches,Copyright stacks and stumps are formed Pearson Education

Geog_Rev_Guide-5thProof.indb 12 22/01/2013 13:29 Coastal landforms: depositional landforms TOP TIP ✓ Depositional landforms are produced on coastlines where mud, sand and Make sure you know how the following depositional shingle accumulate faster than they can be moved away by waves. landforms are formed: beaches, spits and bars. Beaches Beaches are accumulations of sand and shingle formed by deposition and shaped by erosion, transportation and deposition.

Ridges in a beach parallel to the sea are called berms and the one highest up the beach shows where the highest tide reaches.

Figure 2.6 Beaches can be straight or curved. Curved beaches are Figure 2.7 Beaches can be sandy or pebbly (shingle). Shingle formed by waves refracting as they enter a beaches are usually found where cliffs are being eroded and where waves are powerful

FIELDWORK INVESTIGATION You may have investigated beach profi les and sediment characteristics in your fi eldwork.

Spits

material moved along beach in a coastline changes zig-zag way by longshore drift direction (Section A) environment The natural

Samplespit curved with change of wind direction

prevailing winds bring waves in material deposited at an angle in shallow, calm water, to form a spit

Figure 2.8 Spits are long narrow beaches of sand or shingle that are attached to the land at one end. They extend across a bay or or where the coastline changes direction. They are formed by longshore drift powered by a strongly prevailing wind Bars If a spit develops in a bay, it may build across it and link the two headlands to form a bar. This requires a gently sloping beach and no sizeable river entering the bay. Water trapped on the landward side of the bar forms a . 13 Copyright Pearson Education

Geog_Rev_Guide-5thProof.indb 13 22/01/2013 13:29 Factors affecting As well as marine and sub-aerial processes (see page 11), there are a range of other factors that affect coasts, in particular: • geology • sea-level changes • vegetation • human activities. Geology Where a coastline is made up of more and less resistant rocks, the less resistant rocks are eroded more than the resistant rocks. This can lead to a coastline of headlands and bays (see page 12). Geology also affects the shape of cliffs. Hard rocks form high, rugged, steep cliffs. Softer rocks are generally less high and less steep and usually have evidence of slumping.

Vegetation Vegetation helps to protect and preserve coastal landforms. Over time, features such as sand dunes will be colonised and ‘fixed’ by vegetation.

Sea-level changes • Rising sea levels produce submergent coastlines, with (drowned river valleys) and (drowned glacial valleys). • Falling sea levels produce emergent coastlines, with raised beaches (old wave-cut platforms and beaches now above sea level) and relict cliffs. Sea levels have fallen and risen many times in the past. Sea-level rises linked to global warming in the modern era would have a significant effect: many major cities are on low-lying coasts.

Human activities Miami in the US state of Human activities can transform the is an example of a major city (Section A) environment The natural landscapes and features of the coast. A that is vulnerable to sea level rise. The city is built at sea level. wide range of human activities affect the coast. The three main ones are: 1. settlement – many of the world’s most densely populated areas areSample on the coast 2. economic development – for example, fishing, farming, trade, tourism, energy production 3. – controlling the coastline to protect human interests.

Figure 2.9 Downtown Miami 14 Copyright Pearson Education

Geog_Rev_Guide-5thProof.indb 14 22/01/2013 13:29 Coastal ecosystems 1: coral reefs TOP TIP ✓ Make sure you know about Distribution four coastal ecosystems: coral reefs, mangroves, sand dunes and salt marshes. You need to know the physical factors that affect their distributions, their value to people and how they are

Tropic of Cancer under threat. Make sure you know a

Equator case study of one coastal ecosystem.

Tropic of Capricorn

Figure 2.10 The global distribution of coral reefs Coral reefs are huge deposits of calcium carbonate built up entirely by marine organisms. Key factors control their distribution:

Minimum water Sea less than 25 m deep Salt water Clear, clean water – temperature of 18°C – plenty of light sediment blocks light ✓ ✓ ✓ ✓

Value • Biodiversity – the Great Barrier , for example, has 700 species of coral, 1500 species of fi sh, 4000 species of mollusc. • Coral reefs soak up wave energy and so help to protect low-lying coasts from tropical storms. • Fishing – coral reefs support many people in LICs. (Section A) environment The natural • Tourism – more than 150 million people a year visit areas with coral reefs. Threats SampleAny water pollution that blocks A survey in 2012 showed that only 8% of reefs in the Caribbean had live coral light threatens corals, for cover, compared with more than 50% in the 1970s. example from land clearance, algal blooms caused by fertiliser Coral reefs are delicately balanced ecosystems and are easily stressed by run off, increased sediment from sewage outfl ows. Tourist human activities. The following activities pose particular threats: developments near coral reefs pollution can damage the very thing • tourists have come to see. • overfi shing • quarrying of coral for building stone St Lucia in the Caribbean is a good example of how coral reefs • warming sea temperatures – this causes coral bleaching. have been protected by coastal management zoning.

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Geog_Rev_Guide-5thProof.indb 15 22/01/2013 13:29 Coastal ecosystems 2: mangroves TOP TIP ✓ Distribution Make sure you know a case study of one coastal ecosystem. The Sundarbans in Bangladesh is a good example of a mangrove ecosystem.

Figure 2.11 The global distribution of mangroves Mangroves are most common in South-East Asia, and most are now found within 30° latitude of the Equator. Mangroves grow in the so they need to be able to cope with a very dynamic environment: • mangroves have a fi ltration system to cope with salt water • some species have snorkel-like roots so they can take in air when submerged by mud, the tide or by coastal fl ooding • some species have prop roots or buttress roots that keep them stable in the soft mud of the intertidal zone • mangroves have fl oating seeds, which are transported by the waves to start new mangroves. Value • Biodiversity – mangroves are rich in wildlife and act as nurseries for many fi sh species. • The complex root systems of mangroves trap sediment and eventually build up the intertidal zone into

(Section A) environment The natural land. • They soak up wave energy so help protect low-lying coasts from tropical storms. • Mangroves provide fuel and building material. Death tolls from the 2004 tsunami wereSample often higher in coastal areas that had cleared mangroves than those that still had mangroves along their coast.

Threats Bangladesh’s Coastal Zone Policy involves planting mangroves to Mangroves are most threatened by economic development. protect the low-lying country from storm surges and also to Shrimp and fi sh aquaculture is a boom industry in much of coastal • reclaim land. 1,290,000 hectares South-East Asia and has involved large-scale clearance of mangroves. of new land have been reclaimed Mangroves are felled for timber and fuel, and their deforestation clears by using mangroves to trap • sediments and stabilise . land for development.

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Geog_Rev_Guide-5thProof.indb 16 22/01/2013 13:29 Coastal ecosystems 3: salt marshes and TOP TIP ✓ sand dunes Make sure you know a case study of one coastal ash alder ecosystem. Salt marshes rushes/reeds sea lavender make a good case study of an sea couch grass spring high tide carr woodland ecosystem based on tolerance neap high tide upper sea purslane low tide to submergence and salinity. marshes salt marshesthrift sea meadow grass Sand dunes are a good case upper sea manna grass study of colonisation. decreasing frequency of tidal submergence/decreasingcreek salt tolerancemarshes spartina salicornia (pioneer) eelgrass lower algae marshes

mud ats

estuary

Figure 2.12 zones: the frequency of tidal submergence and the level of salinity determine which plants and animals are found in each zone

climax oak, pine, main ridge xed dunes heath birch marram grass on (grey dunes) gorse, bracken, foredunes yellow dunes marram, red broom, heather, sea couch grass, fescue, sea buckthorne marram grass spurge, herbs, heather

embryo dunes Colonising plants in a sand lyme grass, sea couch grass dune ecosystem need to be able Sea to deal with salinity, a lack of water table dune slack moisture because sand drains reeds, rushes, willows quickly, wind, and being covered Figure 2.13 A cross-section through a typical sand dune ecosystem. Over time, the ridges of by windblown sand. dunes are colonised and ‘fi xed’ by vegetation

Value Salt marsh is often drained and reclaimed for farmland or for development but its greatest value is now recognised as a means of coastal defence: the creeks and vegetation slow waves down and reduce the impact of coastal fl ooding, as well as providing a buffer against . Salt marshes are also a key habitat (Section A) environment The natural for wildlife, especially wading birds. Sand dunes are involved in the colonisation of land from the intertidal zone and they also have great recreational value. Threats Sample • Salt marsh is threatened by development, but also by agricultural and industrial pollution and, most of all, by rising sea levels. • Sand dunes are not really under threat. But there are issues with over-use of dunes for recreation, causing a loss of vegetation and the ‘blow out’ of the dune.

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Geog_Rev_Guide-5thProof.indb 17 22/01/2013 13:29 Coastal conflicts

Conflicts between coastal users are referred to as conflicts betweenstakeholders : people with different interests in the coast.

local residents fishermen want clean want harbours, environment, unpolluted waters, jobs, affordable protection from housing competition

employers want farmers want space to build well-drained land, shops, offices, shelter from sea factories winds

developers want government new sites by the wants to build sea for tourist offshore wind developments farms

transport tourists want companies want beaches, hotels, well-connected entertainment, ports and holiday homes, terminals marinas

Figure 2.14 Coastal stakeholders

As Figure 2.15 shows, it is very difficult to reconcile both conservation FIELDWORK INVESTIGATION and development of the coastal environment. Coastal managers often seek You may have investigated the to separate the two, but the impacts of development are often far-reaching. conflicts between development The needs of different coastal stakeholders can often conflict with one and conservation on a stretch of coastline as part of a another as they all compete for the same resources. A conflict matrix is a fieldwork investigation. good way of analysing these conflicts.

Activity Conservation Port and Extracting Fishing Economic Shipping Wind and Beach (Section A) environment The natural of the natural harbour gravel from development wave farms recreation environment operation sea bed Conservation of the natural environment Port and harbour operation Sample Extracting gravel from sea bed

Fishing

Economic development

Shipping

Wind and wave farms

Beach recreation

Key: No conflict or little conflict Some conflict Strong conflict Very strong conflict

Figure 2.15 An example of a conflict matrix for coastal users 18 Copyright Pearson Education

Geog_Rev_Guide-5thProof.indb 18 22/01/2013 13:29 Coastal management TOP TIP ✓ Make sure you know a Coastal management is fundamentally concerned with managing the risks case study of a retreating associated with coastal erosion and/or the risks associated with coastal coastline – causes, impacts and fl ooding. Rising sea levels signifi cantly increase the risks of both. management. A popular UK example is the Holderness coast (see Key fact, left). The village of The northeast coastline of Britain has coastal erosion rates of between 1 m Mappleton on the Holderness and 10 m per year. This is due to the combination of soft rocks exposed to coast has a population of powerful destructive waves. around 100, and has been protected from rapid erosion by two rock and a Coastal management strategies stretch of rip-rap, at the cost of £2 million. While Mappleton Hard engineering methods involve building some type of sea defence. • has been protected, erosion • Soft engineering methods try to work with natural processes to may have been made worse reduce the impact of erosion or fl ooding. elsewhere down the coast.

Strategy Description Advantages Disadvantages Hard engineering Sea wall A wall, often made of Prevents both erosion and Very expensive to build and concrete, which protects flooding (if high enough) to maintain. Obtrusive to the coast from waves look at Groynes Wood or steel piling built at Slows beach erosion, Starves beaches right angles to the beach creates wide beach downstream of sediment, that traps beach material increasing erosion being moved by longshore drift Rip-rap Large piled up to Cheaper to construct than Boulders can be undercut protect a stretch of coast sea walls and does similar and be dislodged in heavy job of absorbing wave storms energy Soft engineering Beach replenishment Pumping or dumping sand Beaches absorb wave Has to be repeated often, (Section A) environment The natural and shingle back onto a energy and help protect which is expensive beach to replace eroded against coastal erosion material Fencing, hedging and Helps stabilise sand dunes A relatively cheap way to Hard to protect larger areas replacing vegetation or beachesSample and reduces protect against flooding and of coastline this way wind erosion erosion Cliff regrading The angle of a cliff is Prevents sudden loss of Doesn’t prevent wave reduced to reduce mass large sections of cliff erosion of the cliffs movement Managed retreat Managed retreat Abandoning existing coastal No expensive construction Often very unpopular with defences and allowing the costs; creates salt marsh – a people threatened by sea to flood inland until it valuable habitat coastal erosion or flooding reaches higher land or a new line of sea defences

There are confl icting views about the value of hard engineering or soft engineering approaches. Most coastal managers aim to use a range of methods depending on the value of what is being protected. Copyright Pearson Education 19

Geog_Rev_Guide-5thProof.indb 19 22/01/2013 13:29 Exam-Style Questions

1 Study Figure 2.16, a map of the Holderness coast, 2 What is managed retreat? (2) . 3 Name two of the four main wave erosion 0 20 km processes. (2) North Flamborough Y York Head 4 Name two landforms formed by coastal erosion. (2) Moors Bridlington Auburn N 5 Name two landforms formed by coastal North sea deposition. (2) Hyde Barmston 6 Explain the difference between swash and backwash. (2) Hornsea Hornsea Beck 7 Use an annotated sketch or sketches to describe Mappleton Old Aldborough how a destructive wave erodes a beach. (4) Great Conden Monkwell 8 Use an annotated sketch to show how longshore drift transports material along the coastline. (4) Old Withernsea Withernsea 9 Describe two ways in which human activity can Out Newton harm a ecosystem. (4)

R Easington iv e Dimlington r H 10 Explain the difference between hard engineering um be and soft engineering methods of coastal r Scunthorpe Ravenser management. (4) Z Odd Grimsby 11 Describe the advantages and disadvantages of using a ‘do nothing’ approach to coastal erosion. (6) Land over 200 metres Towns and villages Coastline 2,000 years ago Lost villages 12 Describe the value to humans of either coral reefs Area ooded in 1906 or mangroves. (6)

Figure 2.16 13 Using a named example, describe the impacts that a retreating coastline can have on people’s lives. (9) a) What marine process is responsible for the retreat of the Holderness coast? (1) Exam Section C question b) What is the coastal at point Y: a bay, a headland or a concordant coast? (1) 14 Briefly describe how a quadrat could be used to collect measurements in a vertical transect c) What is the name of the coastal landform at (Section A) environment The natural up a beach. (3) point Z: a spit, a bar or a stack?Sample (1)

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Geog_Rev_Guide-5thProof.indb 20 22/01/2013 13:29