Physical Case Studies Geography

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Arid environments

AustraliaMining

Once rich in gold, now mines and exports uranium, manganese, opal, nickel

Positiveso Provides jobs local people Olympic Dam employed 3000 people 2005.o Company operating mine pay royalties to government. Goes towards benefiting and

developing area regionally. $45million to South Australian government

o Roxby Drowns benefited improvements to increase in services and multiplier effect mineshave.

Negativeso House prices increase, people cannot afford to buy.o Mine create visible eyesore for miles due to the low relief of the desert landscape. Scars land

with dust, spoil heaps scar the land. Prominent Hill, 1km wide, 50m deep.

o Construction of roads pipelines and processing facilities damage the soil and desertecosystem.

o Uranium and copper ores once crushed treated with chemicals in order to concentratemineral content. Liquid waste (facilities and seepage form dumps) make way into water

supply.

Aborigineso Roads built can be used by aborigines for gathering and going hunting.o Get paid an annual rent.o Sometimes dispute over legal ownership of the minerals. Opposition of new mines as

damages land their land.

Managemento Environmental assessmentso Reduce visual effect mining has on land.o Height of dumps and waste piles.o Re-landscaping land to make it look more attractive.o Water is recycled water from waste water ponds and spray weeds to control spread so they

dont destroy ecosystems.

o Controlled burning of vegetation to encourage spread of native eucalypts.


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Sustainability in Arid environments

Khushab Project

Less than 400mm rainfall a year. Land depends on irrigation but over irrigation lead to reduction incrop yield, land quality and income.

High cost scheme reduce water logging and salinizationo Tackled by installing field under drainage by installing PVC pipeso Constructing new surface water drainso Lining irrigation canals to reduce water losses through seepage.o Education centres for farmers on sustainable water management.

Impacto Thanks to effective drainage groundwater levels have falling, lowering soil salinity and water

logging. Water logged area halved in the first 2 years.

o Per capita incomes increased from $46 in 1989 to $195 in 2005. Means incomes for anaverage family are now 34% above poverty level.

o Improvement in land quality which has increased production of crops e.g. rice and sugar.o Improved drainage has decreased amount of waterborne disease and less damage to homes

through land collapsing.

Chinas Great Green Wall

A wall of 350000km2 of forest to protect farmland and settlements from wind and water erosion,improve land management and to stabilise sand dunes and to reclaim degraded lands.

Korqin Sandy lands (north western China)o 300-550mm of rain a year. Wind + temp means evaporation is 3xs higher than precipitation.o Worsened by preamble soil.o Some of the worst land, desertification worsened by population pressure, over grazing,

clearing of land for agriculture and the removal of trees for timber.

The great green wall project in Korqin aims too Protect cultivated lando Restore soil fertilityo Improve economic well-being of areas inhabitantso Provide populace with a sustainable source of timber


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Arid Erosional Landforms

Aeolian erosion and landforms

Yardangs (Gobi Desert, China)o Wind eroded ridges. Less than 10m high but over 100m often. Wind erosion, possibly harder

rock. Abrasion, they have undercutting at the base.

Ventifactso Cobbles and pebbles abraded or shaped by wind-blown sediment. One side gets abraded.

Desert pavemento As small particles are blown away, big ones stay there and so you get surfaces of coarse

rocky particles that protect the underlying surface from abrasion.

Aeolian deposition features

Rippleso Succession of crests and troughs, right angles to the wind.

Dunes (Great Sand sea, Egypt)o Adequate supply of sando Strong enough wind to transport sedimento Sand accumulates in surfaces of increased roughness, the sand then builds up and hence

traps more sand.

o Often dunes have a steep, slip face. As it gets too steep, you get sand avalanches and itcauses the dune to migrate.

Types of duneso Crescentic dunes

(barchans and transverse dunes) wider than they are long, with a slip face on thedunes concave side. Form when wind mainly blows from one side.

o Linear dunes Straight or slightly curved in plane form Normally more than 100km long, with slip faces on alternate sides. Can be a series

of ridges or isolated ridges.

o Star Dunes Pyramidal sand mounts with slip faces on three or more arms that radiate from the

high centre of the dune. Form in areas of multi-directional wind.

o Parabolic dunes U shaped planforms with convex noses trailed by elongated arms. The arms are

fixed by vegetation.

Fluvial landforms

Alluvial fans and bajadaso Cones of sediment that is deposited by a river as it leaves a steep-walled valley.

Playaso Streams drain to shallow inland basins, where they form, temporary lakes.o These are playas, and when they evaporate they leave behind accumulated salt in

the low lying ground and waters.


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Pediments (Monument Valley, Utah)o Gently sloping, concave slopes forming at the bottom of receding mountain fronts.o Often covered in thin soil and alluvium.o Formed by the parallel retreat of slopes of a plateau or mountain front.o Weathering leads to rock fall, and the rock is removed by water and wind.o They surround mesas, buttes and spires.

Canyons (Grand Canyon, SW USA)o Narrow river valleyso Vertical erosion by streams and river beds due to erosion.o Intense downpours create great energy, to make canyonso Sparse vegetation means a lot of loose rock debris is fed into the streams and rivers during

rainfall. Tools of abrasion.

o Uplift can make the downwards erosion more


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Arches National Park and MOAB

High altitude, 1245m to 1700m. 230mm of rain a year. Winters are cold and summer temps regularly exceed

40.

Opportunitieso Small, just 300km2 and highest concentration of natural arches.o 833000 visitorso Activities like sightseeing, hiking, biking, climbing and camping.o Moab is the base of many activities

Challengeso Overcrowding and congestion, cars queuing to see attractions like delicate arch or garden

wall.

o Cars parked along the side of the road can damage cryptobiotic soil.o Park wants to add a new transport strategy to reserve parking at key attractions, closing pull-

off areas and controlling illegal parking.

Conclusiono Valuable economic resourceo Lots of tourist attractionso Numerous smaller conservation areaso Has wildness, wildlife, guaranteed sunshine and a unique landscape.


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Ecosystems

Plants that have altered their physical structure to survive drought are called xerophytes.o Succulents like cacti, which store water in their tissueso Phreatophytes have long roots to tap watero Many perennial plants are dormant until it rains, and then they spring to life.o Annuals are drought evading, their seeds germinate after rain and the plants complete their

life cycle with a few weeks.

Prickly pearo A cactus, stores water in its fleshy stems, spines are thin leaves to reduce water loss and

protect from animals. Originated in SW USA.

Joshua treeo Native to the Mojave Desert, SW USA. Needle leaves reduce water loss, leaf cells store

water, leaves covered in a waxy layer to reduce water loss.

Tamarisko Extremely long roots, salt tolernet.

Animals need to cope with extreme heat and lack of watero Jack rabbits in North America have evolved enormous ears to dissipate heat.o Pale fur to reduce heat absorption, like the desert fox.o Some animals obtain all their moisture through food, like the desert tortoise.o Kangaroo rats reduce water loss from urine and water loss from breathing by having special

nasal cavities.


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Cold environments

Antarctica

Tourism

Positiveso Over forty thousand people visited Antarctica last year with dozens of tours that occur every

year visit Palmer Station to learn about marine biology, ozone depletion, and the effect of

global warming on Antarctic ice and fauna.

o This then creates a positive economic and social effect for Antarctica.o This desire for people to learn means that every year more and more tourists are allowed to

travel to Antarctica.

o As in order to exploit that boat companies could have numerous trips that could take place inorder to take as many tourists as possible to increase cash flow.

o Tourists guides well trained and help educate people plus provides jobs boat drivers andtour guides.

o Money can help fun scientific research

Negativeso The sheer number of people can disrupt wildlife breeding and reduce populations.o One problem is that most tours land at the same points along the 800-mile-long (1,300-

kilometer-long) Antarctic Peninsula, this can cause wearing of that actual part plus other

factors as it may causes damage to animals habitats.

o Boat crashed Hard clean up. Very remote area to clean up can leave a lot of area damagedand affect fragile ecosystems.

o Tourists often take souvenirs and destroy fauna. Management

o Global warming have considerable effect on destroying environment so restrictions all roundworld prevent global warming.

o Tourism only allowed special parts islands so rest remain preserved for environmental andscientific conservation and studying.

o Arctic Treaty Mineral exploitation, not allowed to be exploited as economic, technical andenvironmental difficulties destroy environment. Been in operation for nearly 50 years. No

activities are allowed that damage the condition of Antarctica and its ecosystem.


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Alaska

Want to exploit oil underneath it.

Positiveso Oil is a finite resource meaning it will run out so as less and less becomes available its price

will increase so more income.

o Provides jobs all parts oil refinery e.g. transport, extraction, exporting etc. Increase GDP percapita and increase quality regional area.

o New roads, transport facilities for oil can be benefited by the locals improving infrastructure. Negatives

o Drilling creates about 40,000m3 of waste per year. This has to be disposed of in pits dug insand. However this is bad as the overall effect is that dumping the waste in a pit is not a

solution as it does not get rid of the waste.

Also some of the waste may seep through the sand into water supplies, as well askilling local fish and birds.

o Oil spills on land are very hard to clean up and can stain the plant and animal life on the land.Oil spills on water are a much more delicate matter.

o Exxon Valdez oil spill Spilt 260,000 to 750,000 barrels 11,000 square miles (28,000 km2) of ocean. Immediate effects included the deaths of, at the best estimates, 100,000 to as many

as 250,000 seabirds, at least 2,800 sea otters, approximately 12 river otters,

300 harbor seals, 247 Bald Eagles, and 22 orcas, as well as the destruction of billions

of salmon and herring eggs.

oThey are extremely difficult to clean up, therefore staying on the sea for a long timedamaging/ destroying delicate ecosystems; such as those concerning the Beluga Whales.

o Finite resource so it will run out and areas jobs are heavily dependent on oil industry so lotsof jobs will be lost when it does run out.
http://en.wikipedia.org/wiki/Common_Sealhttp://en.wikipedia.org/wiki/Common_Seal


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Cold Environments

Glacial Erosional landforms

Glacial Trough ( U shaped valleys)- e.g Yosemite Valley, California

Begins as V shaped valley, end as U shape Freeze thaw weakens valley floor and sides- more easily eroded. Weathering ( e.g Freeze thaw) creates debris for the glacier, carried as subglacial debris (at the

bottom of glacier) or debris along the sides of the glacier

Glacier occupies the whole valley, the debris causing abrasion along the valley sides and base Plucking also removes rock material- speeds up erosion. Result- the valley deepens and sides become more vertical, creating the U shape.

Hanging Valleys

Tributary valleys which join up to the main valley Are smaller and are at a higher level because the glaciers that occupied them were much smaller so

less erosion happened.

Can get waterfalls in themTruncated Spurs

Ridges of land between the tributary valleys which have been eroded away by the ice.Ribbon Lakes (need another example)

Long thin lakes formed after the ice age

Occupy the bottom of some glacial troughs

Striations

scratches or gouges cut into bedrock by abrasion.

Fjord- e.g Geiranger, Norway

Its a glacial trough thats been flooded with sea water Valley eroded deeply, below sea level When it reaches the coast, it floods with sea water.

Cirque- e.g Blea Water, Lake District UK

Snow collects in a hollow/ depression in the rock, turns to ice. Freeze thaw on the rock above glacier provides debris for abrasion. Debris causes abrasion downwards. Plucking steepens the back wall and adds to debris. Glacier has a rotational movement which causes abrasion and deepens its base, creates the armchair

shape.

Freeze thaw steepens the back wall and causes it to retreat.


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Tarn

Melt water from glacier forms a little lake in the cirque called a tarnArete Ridge

At the back of the cirque Steep sided ridges Caused by freeze thaw

Roche Moutonnee- e.g Yosemitte Park, California

Gentle on one side, steep on the other. Its a hard resistant outcrop on the valley floor. Upstream side is smooth and gentle due to abrasion Downstream side is rough and steep due to plucking

Pyramid Peak- e.g Matterhorn, Swizerland

Several cirques form back to back, creates a mountain peak

Glacial Depositional Landforms

Erattic- e.g Montana, USA

Large rock/ boulder been dumped by the glacier as it melts (deglaciation) They are in random positions

Terminal Moraine- e.g Dana Glacier, California

Moraine- mixture of loose rocks and boulders deposited by a glacier. Builds up at the end of the glacier as it remains stationary for a long time. Forms semi circular hills of till. ( till is the stuff a glacier leaves behind)

Medial and Lateral Moraine- e.g Gorner Glacier, Switzerland

Lateral moraine- is deposited where the sides of the glacier were Medial moraine- formed when two glaciers meet, two lateral moraines merge to form a medial

moraine in the centre.

Fluvioglacial Deposits ( meltwater makes them)

Melting of ice forms meltwater streams Meltwater streams flow on the surface of glaciers (supraglacial) in tunnels within glaciers (englacial)

and beneath the ice (subglacial)

They carry a lot of debris Deposits their load on the valley floor as they flow away from the glacier.

Esker e.g North Saskatchewan, Canada

Long, winding ridges of sand and gravel deposits Formed from meltwater streams flowing in meltwater tunnels inside or underneath the glacier.


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Outwash Plains e.g Southern Iceland

At the end of a glacier where the meltwater washes out onto low lying ground. Meltwater streams drop their load, its well sorted and their stratified into layers Corse material (gravel) deposited near ice, finer materials (sand) carried further down the valley.

Cold Environments Ecosystems

Tundra e.g Point Barrow, Alaska

Location

Arctic tundra- North or south of the equator, mainly 60 North e.g Alaska, Canada, Greenland Alpine tundra- high mountain environments e.g Rockies, Himalayas

Landscape

Permafrost- permanently frozen ground. Water in the ground is frozen. In Alaska 82% of land underlain by permafrost. In summer, the active layer thaws leads to waterlogging Spring/ Autumn- freeze thaw in active layer, leads to slumping of the soil.

Climate

Long cold winters sun hardly above horizon -29C Brief, cool summers with short growing season 5C Precipitation low ( very little snow) Low angle of the sun + white snow means most of the suns energy is reflected away.

Short growing season of around 2 months. Strong winds- damage to plants and increased transpiration.

Soils

Bacterial activity is low, waterlogging leads to formation of acid humus. Thin soils- low productivity and low biomass Nutrients in soil is limited because there is little weathering Water cannot percolate downwards in places- the ground is frozen Frozen ground so plant roots struggle to get in and reach nutrients.

Plants

Low lying and little vegetation Have to adapt to short growing season, high wind, cold temps, low nutrients etc Most plants are perennials (live for many years)

o Mosses- high water retentiono Lichens- grow on rocks, drought resistant (survive without water)o Dwarf shrubs- low lying so reduce impact of the wind and transpiration. has a warmer

microclimate.

o Purple Saxifrage- grows in shallow soils and bare rock outcrops, leaves covered in hairs (heatretention) , flowers early in spring ( due to short growing season), self-pollinate due to lack ofinsects.


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Animals

Low diversity due to short growing season and extreme climate Food chains fragile as they are short and lack biodiversity- if messed with causes serious problems. Arctic foxes- thick fur to keep warm, white fur to blend in, small ears and face to lower surface area

and heat loss ( its compact) Geese- migrate to lower latitudes in winter to keep warm.

Why fragile?

Ecosystems finely balanced Once damaged, ecosystems slow to recover Ecosystems vulnerable to climate change and human pressure.

Ecosystems and human interference

Permafrost problems, e.g Fairbanks, Alaska

Warmer temps and climate change means more of the active layer melting Will cause carbon locked in the permafrost to be released into atmosphere- 1000 gigatons of carbon

is locked in the permafrost worldwide.

Heat from buildings melts permafrost- sinks and damages building Melting causes building to slump and lean at angles- grounds unstable Ice can also form underground, expand and cause frost heave (lifts off the ground) Water supply hard due to water freezing in pipes.

Solutions

Rise buildings on frames-airs flows under house to stop thawing Thaw the ground before building on it so its stable Put gravel under roads to reduce frost heave as water drains away. Build water pipes above ground and insulate them to stop freezing.

Skiing in Alps e.g Zermatt

Ground temps rising- only slightly below 0C e.g climate change Causes more thawing of permafrost. Steep slopes and melting of ice ( waterlogging the ground) leads to more rockfalls, landslides and

mudflows

Melting causes ground to be unstable. Ski l ifts and resorts are built in this ground so problems???


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Physical Case Studies Geography

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