Physical geography

Question 1

Define a natural hazard. Define a hazard risk and what factors can affect the risk?

Answer 1

Natural hazard:
— Sudden, severe events that make the natural environment hard to manage.

Hazard risk:
— The chance of being affected by a natural hazard. The factors that affect this are urbanisation, poverty, climate change and farming.

Question 2

What happens at the tectonic plate margins?

Answer 2

Constructive: plates move apart from each other and magma forces its way to the surface
Destructive: the plates move towards each other and the thin, dense oceanic crust moves under the less dense, thicker continental crust
Conservative: the two plates move past each other and the friction builds up to cause earthquakes

Question 3

Using named examples, compare the effects and responses of a tectonic hazard in places of contrasting wealth (Chile)

Answer 3

Chile earthquake, February 2010, magnitude 8.8:

Primary effects:

• – 500 killed, 12 000 injured and 800 000 affected
• – Destruction of infrastructure
• – Power, water and communications cut
• – US $30 billion damage

Secondary effects:

• – Landslide
• –Tsunami

Immediate response:

• – Aid sent in
• – Roads repaired in 24 hours
• – Power and water restored in 10 days

Long term response:

• – Foreign aid needed
• – Full recovery in 4 years

Question 4

Using named examples, compare the effects and responses of a tectonic hazard in places of contrasting wealth (Nepal)

Answer 4

Nepal earthquake, April 2015, magnitude 7.9:

Primary effects:

• – 9000 killed, 20 000 injured, 8 000 000 affected
• – Infrastructure destroyed
• – Power, water, communications cut
• – US $5 billion damage

Secondary effects:

• – 19 people were killed by an avalanche on Mount Everest
• – Flooding blocked rivers

Immediate responses:

• – Overseas aid sent in (e.g. Oxfam)
• – Search and rescue helicopters sent in
• — 300 000 migrated from Kathmandu for shelter

Long term responses:
— Infrastructure repaired and roads cleared

Question 5

What are some reasons people continue to live in areas at risk of tectonic hazards?

Answer 5

• – Fertile soil
• – Quality of life is cheaper
• – Little education on tectonic hazards
• – Not enough money to move abroad
• – Family
• – Tectonic hazards are very rare
• – Earthquake resistant buildings
• – Effective monitoring of tectonic hazards

Question 6

What are the four management strategies to reduce the risk of tectonic hazards?

(HINT: 3 P’s and 1 M)

Answer 6

• –Monitoring
• – Planning
• – Prediction
• – Protection

Question 7

What are the three cells associated with global atmospheric circulation from the equator outwards?

Answer 7

• – Hadley cell (0-30 degrees)
• – Ferell cell (30-60 degrees)
• – Polar cell (60-90 degrees)

NOTE: refer to another source for more on global atmospheric circulation

Question 8

What conditions are required for a tropical storm to form?

Answer 8

• – 5-15 degrees North and South of the equator
• – ocean temperatures above 26.5 degrees
• – intense heat and humidity

Question 9

How do tropical storms form?

Answer 9

• – Rising air draws evaporated water vapour up from the ocean surface which cools and condenses to form thunder clouds
• – The condensation release more heat which pulls up more water vapour
• – Multiple thunderstorms gather to form a massive storm
• – Coriolis forces spin the storm at over 75 mph.
• – Prevailing winds drift the storm over the ocean surface and gather energy and strength so it gets faster
• – When the tropical storm reaches land, it loses energy and the storm weakens due to the friction with land.

Question 10

Use a named example of a tropical storm to show its effects and responses.

Answer 10

Typhoon Haiyan, November 2013, Category 5 storm, Tacloban in the Philippines:

Primary effects:

• – 5m storm surge
• – 90% Tacloban ruined
• – 6300 killed
• – Over 600 000 displaced
• – 40 000 homes destroyed

Secondary effects:

• – Power, water and sanitation cut off
• – 14 million affected, 6 million jobs lost
• – Infrastructure destroyed
• – Violence in Tacloban

Immediate responses:

• – Over 1200 evacuation centres set up
• – International aid

Long term responses:

• – Infrastructure rebuilt
• – Improve local economy
• – Cash for work programme

Question 11

Define weather in comparison to the definition of climate

Answer 11

Weather:
— The daily conditions of the atmosphere

Climate:
— The average weather conditions over a long period of time

Question 12

Give an overview of the weather hazards experienced in the UK.

Answer 12

2003 - heatwave
2007/08 - floods
2009 - heavy snow
2009 - floods
2010 - heavy snow
2013/14 - floods
2015/16 - floods

Question 13

What is a recent example of the UK extreme weather with causes, impacts etc?

Answer 13

Somerset Levels Flood, 2014, south-west England

Causes:

• – Low lying land
• – Prolonged rainfall
• – Clogged rivers not dredged for 20 years

Impacts:

• – Over 600 houses flooded
• – 16 farms evacuated
• – Villages cut off
• – £10 million damage
• – Infrastructure destroyed
• – Massive debris clearance required

Immediate responses:

• – Boats as transport
• – Support from the community

Long term responses:

• – Roads raised
• – Riverbanks raised and strengthened
• – £20 million Flood Action Plan launched by Somerset County Council and Environment Agency to reduce future risk

Question 14

What are some recent evidence for climate change?

Answer 14

• – Shrinking ice glaciers
• – Melting ice
• – Rising sea levels
• – Seasonal changes
• – Temperature changes

Question 15

What are the three main natural causes of climate change in detail?

Answer 15

Orbital changes - the Milankovitch cycle:

• – Eccentricity: every 100 000 years the orbit changes from circular to elliptical
• – Axial tilt: the Earth’s axis moves back and forth
• – Precession: the axis wobbles

Solar activity:
— The dark patches on the sun are called sunspots and indicate short term reduced temperatures. They are accompanied by solar flares to increase temperature. Over 11 years, sunspots increase from a minimum to maximum.

Volcanic activity:
— Volcanic ash blocks out the sun which reduces temperatures.

Question 16

What are the human causes of climate change in detail?

Answer 16

• – Deforestation which increases carbon dioxide levels so contributes to global warming
• – Burning of fossil fuels
• – Agriculture

Question 17

How can we manage climate change?

Answer 17

Mitigation strategies (reducing risks):

• – Alternative energy sources
• – Carbon capture
• – Planting trees
• – international agreements: Paris agreement

Adaptation strategies (responding to change):

• – Change in agriculture
• – Reducing risk from rising sea levels

Question 18

Give an overview of the description and characteristics of large scale global ecosystems.

Answer 18

• –Tundra: 60-70 degrees north, cold, windy and dry conditions
• –Deciduous forests: 20-60 degrees north
• –Temperature grassland: 30-40 degrees north and south of the equator, warm and dry summers
• – Mediterranean: hot, sunny, dry summers and mild winters
• – Desert: hot in the daytime, cold in the nighttime, very low rainfall
• – Tropical rainforest: high temperatures, heavy rainfall
• – Tropical grassland: 15-30 degrees north and south of the equator
• – Polar: north and south poles, low temperatures and dry conditions

Question 19

Where are tropical rainforests found?

Answer 19

Between the Tropic of Cancer and the Tropic of Capricorn

Question 20

What are the layers of the rainforest?

Answer 20

• – Shrub layer
• – Understory
• – Canopy
• – Emergent

Question 21

What are the causes/ threats and impacts of deforestation in Malaysia?

Answer 21

Causes/ threats:

• – Mineral extraction
• – Selective logging
• – Road building
• – Commercial farming (palm oil)
• – Subsistence farming (slash and burn)
• – Population growth
• – Energy development

Impacts:

• – Reduced biodiversity
• – Contribution to climate change
• – Soil erosion

Question 22

What are some distinctive characteristics of a tropical rainforest?

Answer 22

• – Biodiversity
• – Iron-rich soil however is infertile
• – Hot and humid with lots of rainfall

Question 23

What percentage of Malaysia is tropical rainforests?

Answer 23

67%

Question 24

What are some economic gains and losses of deforestation in Malaysia?

Answer 24

Economic gains:

• – Job creation
• – Improved transport and infrastructure benefits development and tourism
• – Hydroelectric power is plentiful

Economic losses:

• – Increased water pollution in dry climates limits supplies
• – Forest fires pollute the environment and destroy habitats
• – Plants for basic medicines could potentially become extinct
• – Rainforest tourism would decrease

Question 25

Why should rainforests be protected?

Answer 25

• – Lots of biodiversity
• – Plants take in carbon dioxide for photosynthesis which decreases global warming and climate change
• – Benefits to medicine
• – Valuable resources
• – Tribes live in the rainforest so if not protected then they would lose their homes

Question 26

How can rainforests be managed?

Answer 26

• – Selective logging and replanting: avoid destructive clear felling
• – Conservation and education: preservation of rainforests for scientific research and tourism
• – International agreements: recognising the global importance of rainforests
• – Ecotourism: introduces people to the idea of the rainforest and tourism to provide a long-term income for them

Question 27

What are the characteristics of cold environments?

Answer 27

Polar:

• – Extreme temperatures, winter can drop below -50 degrees
• – Permafrost covered in ice
• – Few mosses on the ice
• – Polar bears have thick fur and large paws

Tundra:

• – Extreme temperatures, winter can drop below -20 degrees
• – Warm brief summers
• –Surface permafrost melts in summer which causes water logging
• – Low growing so protected from strong winds, covered hairy stems for insulation
• – Lots of species as more food options
• – Less extreme climate

Question 28

What are the opportunities for development in Svalbard?

Answer 28

• – Tourism: more cruise passengers
• – Fishing: over 150 species of fish, fishing is managed sustainably with fishing nets and quotas
• – Mineral extraction: rich reserves of coal
• – Energy development: coal-fired power station, and geothermal energy is most likely the future energy source

Question 29

What are the challenges for development in Svalbard?

Answer 29

• –Extreme temperatures: the temperatures can drop below -30 degrees, and there is a risk of frostbite therefore several layers of clothing are required.
• – Construction: permafrost can melt, they build in the brief summer period
• – Accessibility: Svalbard is only accessible by sea or air, no roads outside Longyearbyen
• – Services: limited services, pipes have to be insulated or heated and raised above the ground

Question 30

How are cold environments fragile and why should they be protected?

Answer 30

These environments take a while to be established and are easily ruined by human activities

Should be protected because:

• – Indigenous people depend on wildlife and habitats to survive
• – Lots of biodiversity
• – Can be used for scientific research

Question 31

What strategies can be used to balance the risks of economic development and the conservation of cold environments?

Answer 31

• – Trans-Alaskan pipeline: using technology to prevent ice tankers moving in winter, raised and insulated to prevent hot oil melting the permafrost below while allowing caribou to migrate underneath
• – Government actions: laws put in place to protect Alaska’s environment e.g. Antarctic Treaty which prevents economic development, promotes scientific research and controls tourism
• – Conservation groups work with companies to create sustainable plans for fragile environments

Question 32

What is the fetch of a wave?

Answer 32

Fetch:

— The distance the wave has travelled. The longer the fetch, the bigger the wave.

Question 33

What is the swash and backwash?

Answer 33

Swash:
— The water that moves up the beach.

Backwash:
— The water that flows back towards the sea

Question 34

What are the types of waves and their characteristics?

Answer 34

Destructive:

• – Strong backwash erodes the sand and pebbles on the beach and removes sediment from the beach
• – Weak swash
• – Short wavelength
• – Steep waves

Constructive:

• – Weak backwash
• – Strong swash which deposits material onto the beach and helps with the construction of a beach
• – Long wavelength
• – Low waves

Question 35

Explain the weathering processes.

Answer 35

Mechanical:

• – Freeze thaw
• – Water is collected in cracks in the rocks. It then freezes up and expands at night which makes the cracks larger. As temperature rises, the ice thaws and water seeps deeper into the rocks. The repeated freezing and thawing make rock fragments break off.

Chemical:

• – Carbonation
• – Rainwater absorbs carbon dioxide which makes the water slightly acidic. It then comes in contact with the alkaline rocks such as limestone or chalk and dissolves over time

Question 36

What are the four mass movements?

Answer 36

Mass movements:

• – Rotational slip: slumping of saturated soil and weak rocks along a curved surface
• – Rockfall: rocks break away and fall down
• – Landslide: blocks of rock slide downhill
• – Mudflow: saturated soil and weak rocks slide downhill

Question 37

What are the four erosion processes?

Answer 37

Erosion:

• – hydraulic action: waves hit cliff then water enters the rocks and crack
• – abrasion: grinding
• – attrition: rocks hit against each other and become more rounded
• – solution: dissolving

Question 38

How is sediment transported?

Answer 38

Transportation;

• – saltation: bouncing
• – solution: dissolving
• – traction: large pebbles roll
• – suspension: particles carried in water

Question 39

What is longshore drift?

Answer 39

Longshore drift:
— How sediment moves along the beach. Waves approach the beach at an angle due to the direction of the prevailing winds. The sediment is then carried back down the coast in a zigzag motion and this is known as longshore drift.

Question 40

Why is sediment deposited in coastal areas?

Answer 40

When the water slows down and waves lose their energy, sediment is deposited on the coast. This is how beaches are often formed.

Question 41

What factors influence coastal landforms?

Answer 41

Factors:

• – Rock type: softer and less resistant rock is eroded more easily whereas tougher, more resistant rocks don’t erode as easily.
• – Geological structure: includes the way rocks have been folded or tilted. Faults in the rocks form weaknesses.

Question 42

What are the characteristics and formation of coastal landforms resulting from erosion?

Answer 42

Headlands and bays:
— Tougher, more resistant rock is eroded to form headlands then softer rock erodes more easily to form sheltered bays which is where beaches form by deposition.

Cliffs and wave-cut platforms:
— Waves break against the base of a cliff and erode via hydraulic action and abrasion. This forms a wave-cut notch. Over time the notch deepens and the base of the cliff continues to erode then the overlying cliff becomes unstable and collapses. This causes the cliff to retreat then the backwash then carries away this material forming a wave-cut platform and this process retreats.

Caves, arches, stacks and stumps:
— Faults in the rocks widen due to due to hydraulic action and abrasion forming a cave. As the cave gets wider, it breaks through the headland to form an arch. Erosion continues and the base of the arch eventually gets wider causing the roof of the arch to collapse due to weathering processes. This leaves an isolated stack which eventually erodes and collapses to leave a stump.

Question 43

What are the characteristics and formation of coastal landforms resulting from deposition?

Answer 43

Beaches:
— Beaches are created by constructive waves as they have a strong swash and weak backwash. Sandy beaches are found in sheltered bays. Pebble beaches are found where there is lots of erosion from cliffs. Beaches are formed when low energy coastlines enter a bay then refract due to shallow water and lose energy therefore depositing sediment to build up a beach.

Sand dunes:
— Sand blown inland forms dunes. Embryo dunes form around obstacles such as rocks then develop and are stabilised by vegetation to form foredunes and yellow dunes. The decomposition of vegetation makes the sand more fertile which grows more plants.

Spits and bars:
— A spit is a long finger of sand or shingle that juts out into the sea and curves. A bar is formed when longshore drift causes the spits to grow across a bay. A spit is formed when longshore drift carries material along the coast and then is deposited due to a change in the shape of the coastline. It then curves due to a change in wind direction then the water behind the spit is sheltered and silt deposits build up forming a salt marsh. To form a bar, a spit grows across a bay due to longshore drift, joining two headlands together. Shallow lakes are trapped behind forming a lagoon

Question 44

Give an example of a coastline in the UK and identify its major landforms and erosion and deposition.

Answer 44

• – Swanage: south coast of England on the Jurassic coast
• – One of the surrounding coastal areas is Poole Harbour where two spits have formed at the mouth
• – Hard rock: chalk, limestone
• – Soft rock: clay and sands
• – Erosional landforms: Old harry stack, arches and cliffs, Ballard point (headland), Durlston head (headland), Swanage bay
• – Deposition landforms: Swanage bay (broad sandy beach), Studland bay (lagoons, salt marshes, sand dunes and beaches)

Question 45

What are the two types of coastlines?

Answer 45

Concordant:
— Form where rock types run parallel to the coast so it erodes in one line

Disconcordant:
— Form when there are alternating bands of harder and softer rock. This creates headlands and bays.

Question 46

Evaluate soft engineering management strategies of coastal areas

Answer 46

Beach nourishment:

• – This is the replacement of the beach or cliff material removed by erosion or longshore drift.
• – The beach is a natural defence against erosion and flooding.
• – The beach attracts tourists.
• – Cheap
• – Requires constant maintenance as the material is washed away

Reprofiling:

• – Redistribution of sediment from the lower part of the beach to the upper part.
• – Cheap and simple
• – Reduces wave energy
• – Only works when the wave is low
• – Constant maintenance

Managed retreat:

• – Allowing coastal areas to erode or flood generating low-value areas so places not used for housing or agriculture
• – Cheap
• – Encourages beach development
• – People can lose houses or farmland so will need compensation

Dune nourishment:

• – Planting marram grass on sand dunes to stabilise dunes and trap sand to build them up
• – Cheap
• – Natural-looking coastline
• – Easily damaged by storm waves
• – Areas to be zoned off from public

Question 47

Evaluate hard engineering management strategies of coastal areas

Answer 47

Sea walls:

• – Concrete walls are built at the cliff edge to prevent erosion and are curved to reflect energy into the sea
• – Very effective at protecting the cliff base
• – Have promenades for people to walk across
• – Expensive, costs about £2000 per metre
• – Powerful waves can break and erode the wall

Groins:

• – Wooden or rock structures built perpendicular to the sea
• – Builds up the beach to attract tourists
• – Traps sediment carried by longshore drift
• – However, trapping sediment starves beaches further down so there is increased erosion elsewhere
• – Unattractive

Gabions:

• – Rocks held in mesh cages and then are placed in areas prone to erosion
• – Cheap, about £100 per metre
• – Absorbs wave energy
• – Unnatural
• – Not very strong

Rock armour:

• – Large boulders are placed at foot of the cliff to break waves and absorb their energy
• – Cheaper than the sea wall
• – Easy maintenance
• – Rocks are imported so don’t fit local geology
• – Expensive to transport

Question 48

Evaluate the management scheme put in place at Medmerry.

Answer 48

Medmerry managed retreat:

• – Flat low-lying land at Medmerry, near Chichester in southern England
• – Previously protected by sea wall up until 2013 when it was allowed to be breached so some of the farmland could flood
• – Cost £28 million
• – Creates large natural salt marsh
• – Protects surrounding farmland and caravan parks from flooding
• – Establishes wildlife habitat and encourages visitors
• – Embankments were built to protect farmland, roads and settlement. This is known as coastal realignment.

Question 49

Evaluate the coastal management scheme in Lyme Regis.

Answer 49

Lyme Regis:

• – Small town in Dorset, popular with tourists
• – Issues are unstable cliffs, powerful waves cause rapid erosion, sea walls have been breached many times
• – Set up in the early 1990s for long term coastal protection, completed in 2015
• – Population of 4000 normally but beach attracts tourists so the population grows to about 16,000

Phase 1:

• – 250-year-old sea wall reaching failure so new sea wall built
• – Rock armour was put in place to stabilise the cliff
• – New promenade constructed to the east of the mouth of River Lim
• – Completed in 1995
• – Cost £10 million

Phase 2 (2005-2007):

• – Cost over £22 million
• – Expected landslide within 5 years so slope put in place to stabilise it
• – Reprofiling beach to absorb wave energy
• – New rock armour installed around Cobb gate to absorb wave energy
• – Sea wall extended at Cart gate

Phase 3 (not completed as costs outweighed benefits)

Phase 4 (2013-2015):

• – New sea wall east of Lyme Regis that cost £20 million
• – Risk of landslide
• – Groynes were in disrepair
• – Extensive nailing, piling and drainage for stabilisation
• – Secured 390 metres of construction for 50 years
• – Completed June 2015

Total cost: over £43 million

Question 50

What is a drainage basin?

Answer 50

Drainage basin:

— The area of land drained by a river and its tributaries

Question 51

How does the river’s long profile and cross profile change downstream?

Answer 51

Long profile:
— Steep gradient and high altitude in the upper course. Downstream, the gradient and altitude decrease as it gets closer to the sea.

Cross profile:
— The river is very narrow in the upper course and seems to get wider as you go downstream towards the mouth of the sea. In the upper course, the valley is steep-sided and v-shaped. The river flow is very fast and the water is shallow. In the middle course, the river gets wider, deeper and slower. The valley is flatter and wider. In the lower course, the river is at its deepest, widest and slowest. It has large sediment load. The valley is at its widest and flattest.

Question 52

What are the two types of erosion and the four erosion processes in rivers?

Answer 52

Types of erosion:
— Vertical and lateral

Erosion processes:

• – Hydraulic action: the force of water hitting against river beds and banks then air becomes trapped in the cracks causing the rocks to break
• – Attrition: stones knocking against each other and becoming smaller and rounder
• – Abrasion: grinding of rocks after hitting beds or banks
• – Solution: dissolving of rocks

Question 53

What are the transportation processes in rivers?

Answer 53

Transportation:

• – Solution: dissolved load
• – Suspension: small sediment carried in the river
• – Traction: large particles/boulders rolling along the riverbed
• – Saltation: bouncing of pebbles

Question 54

Why does a river deposit material?

Answer 54

As the river slows down it loses energy and deposits its materials.

Question 55

Where do erosion, transportation and deposition mainly happen in the river?

Answer 55

• – Erosion normally takes place in the upper course and sometimes in the middle course.
• – Transportation normally happens in the middle course
• – Deposition tends to happen in the middle and lower course

Question 56

What are the characteristics and formations of landforms resulting from erosion?

Answer 56

Interlocking spurs:
— A river cuts down into the valley and erodes vertically. Where there are areas of harder rock, the river bends around it which creates the interlocking spurs.

Waterfalls and gorges:
— Hard rock sits on top of soft rock. As the river flows over the hard rock, it forms undercutting due to hydraulic action and abrasion of the soft, less resistant rock and a plunge pool is formed. This creates an overhang of hard rock which eventually collapses due to weight and gravity and the waterfall retreats. As the waterfall continuously retreats, a gorge is formed.

Question 57

What are the characteristics and formation of landforms resulting from erosion and deposition?

Answer 57

Meanders and ox-bow lakes:

• – Meanders are bends in the river found typically in the middle course of the river. Thalweg (the line of fastest flow) causes erosion on the outside bend of the river which creates a river cliff (undercutting of the bank) and deposition on the inside bend which creates a slip-off slope (a build-up of sediment).
• – Constant erosion on the outside bends narrow the neck of the meander which causes the meanders to move closer together. During a flood, the river takes the shorter and straighter route so its cuts through the neck. Deposition then happens and cuts off the meander leaving an oxbow lake.

Question 58

What are the characteristics and formation of landforms resulting from deposition?

Answer 58

Floodplains and levees:

• – A floodplain is the wide, flat area of land covered in water when a river bursts its banks. They are created by floods depositing layers of silt to form alluvium. This causes the floodplain land to often be very fertile.
• –When a river floods, it loses its energy which results in the deposition of coarser material first then smaller material like fine sand and mud. This increases the height of land over time as the river keeps flooding. Levees act as a method to prevent flooding in the future.

Estuaries:
— This is where the river meets the sea. When the tides rise, the river can’t flow into the sea meaning the velocity falls and it loses its energy. This causes the river to deposit sediment forming mudflats which become salt marshes

Question 59

Give an example of a river valley in the UK and identify its major landforms of erosion and deposition.

Answer 59

River Tees:

• – Northeast England
• – Source in the Pennine Hills and flows east towards the North Sea
• – Source is 893m above sea level
• – High Force waterfall drops 20m
• – Waterfall is made up of hard igneous rock called whinstone and soft rock called limestone
• – Flows near Barnard Castle in the middle course where there are loads of meanders
• – Passes Yarm in the lower course where there are even more meanders and oxbow lakes
• – Has levees and estuary mud which supports the wildlife in the area
• – Reaches sea at Middlesborough

Question 60

What are the human and physical factors affecting flood risk?

Answer 60

• – Heavy rainfall - less chance of water being soaked up = increased flood risk
• – Prolonged rainfall - soil becomes saturated = surface run off = increased flood risk
• – Land use - more building = more impermeable surfaces = increased flood risk
• – Geology - impermeable rocks do not allow water to pass through cracks = increasing flood risk
• – Relief - a steep valley = increased flood risk as water runs off into water more
• – Deforestation - less trees = less water soaked up = increased flood risk

Question 61

What is the use of a hydrograph? What is the lag time?

Answer 61

Hydrograph:
— Shows the discharge of rainfall over some time. Lag time is the time between peak rainfall and peak discharge. Shorter lag time = increased flood risk

Question 62

What is hard engineering? Give the costs and benefits of the hard engineering management strategies.

Answer 62

Hard engineering: using artificial structures to manage flooding.

Dams and reservoirs:

• – Can produce HEP
• – Reservoirs can attract tourists
• – Expensive to build
• – People are displaced
• – Habitats can be flooded which leads to rotting vegetation and contributes to greenhouse gases

Channel straightening:

• – Cutting through meanders so there is a straighter path
• – Increases flood risk downstream as water flows faster
• – Expensive
• – Can be unattractive and damages wildlife habitats

Embankments:

• – Raising the river banks to hold more water
• – Relatively cheap, sustainable and looks natural

Question 63

What is soft engineering? Give the costs and benefits of the soft engineering management strategies.

Answer 63

Soft engineering: using sustainable and natural methods to manage flooding.

Afforestation:

• – Building trees to soak up water
• – Cheap and makes habitat look nice

Floodplain zoning:

• – Restricting different land uses to certain areas of the floodplain
• – Difficult to implement on developed land

Warnings and preparation:

• – People have time to protect property
• – Not as effective as flash floods can happen
• – Does not actually stop flooding

River restoration:

• – Restoring a river back to its natural shape after being artificially changed
• – Slows down water flow so flood risk is reduced

Question 64

Give an example of a flood management scheme in the UK.

Answer 64

Banbury management scheme:

• – 30 km north of Oxford
• – Most of the town is on the floodplain of River Cherwell
• – In 1998, Banbury was flooded which cost £12.5 million in damage
• – Flooded again in 2007
• – The A361 was raised so that during floods, it avoids disruption
• – Embankments and flood walls built
• – Floodwater storage was built to control the rate of flow towards Banbury when there is high rainfall
• – New footpaths and parks built around the river which improves quality of life
• – Overall scheme cost an additional £18.5 million