Hot Deserts

Question 1

What makes a desert ?

Answer 1

-Anywhere on Earth receieving less than 250 mm of percipitation yearly . Percipitation extremely unreliale .
-Extremely aird places , not always hot .

Question 2

Where are Deserts found ?

Answer 2

-Found in subtropical areas between 20 and 30 degrees north and osuth of the equator .
-Deserts expereince extreme range of temperatures in a single day .

Question 3

What is the meaning of a diurnal temperature rnage ?

Answer 3

Extremely hot in the day and extremely hot at night .

Question 4

Why does the desert have a large diurnal temperature range ?

Answer 4

Cloudless skies allow high levels of insolaion in the day time whic also permits heat loss at night .

Question 5

Why is there a lack of cloud and rain in the desert ?

Answer 5

-Deserts form due to the hadley cell , air which is warmed up at the equator descends , forming a persistent belt of high pressure (Sinking dry air )

Question 6

Explain Hot desert soils

Answer 6

-Due to hot climate soil-forming processes are limited by shortageopf water .
-lack of vegetation so little organic matter

Question 7

Explain irrigated Hot desert soils

Answer 7

-Some deserts are potentially fertile because important nutrients for plant growth like calicum can’t be leached away .
-Irrigation(water) means land can be highly productive for agriculture. Lliek oil-rich Saudi Araiba and Southern USA enefitted massively due to irrigation .

Question 8

How have plants adapted to dry conditions ?

Answer 8

-Plants that can survive in very dry conditions are called xerophytes . Have a range of adaptations including thick waxy cuticles and shredding of leaves to reduce transpiration .

Question 9

How have plants adapted to high temperatures ?

Answer 9

-Some plants have the bulk of their biomass below the ground surface where temperatures are cooler .

Question 10

How have plants adapted to short periods of rainfall

Answer 10

deserts bloom suddenly after rainfall so to complete their life cycle quickly .

Question 11

How have animals adapted to the desert ?

Answer 11

-adpated to the hot tepm ad cold night shoratge of water .
-Mmany creatures avoid sun spednign days under stones and are nocturnal .

Question 12

How do animals tackle water issue ?

Answer 12

-Save water loss by havng fast sweat glands and get water from their food . Kangarros feed on dry vegetation , seeds which have moisture , produce dry feaces n concenrtated urine .

Question 13

How do animals catch prey ?

Answer 13

-Developed ways catch pray , fennic fox acute hearing , fast lizards .
Camels - have padded feet to stop it sinking into loose sand .
Long legs to keep the body well above hot sand , nostrils close during sandstroms and eyelashes long and doubele eylid protection from sand .
-Shaggy coat keep warm , mouth can chew tough plants and store 60 litres water in stomach , Fat in hump if food is scarce , can travel km per hour across desert .

Question 14

wht are the bioitic parts of the desert

Answer 14

plants and animals

Question 15

what are the abiotic parts of the desert

Answer 15

soil , underlying rocks adnd water supplly .

Question 16

How is desert interedependent

Answer 16

-interdepenendency betwene biotic and abiotic shown by different parts of food web animals eating plants that have gainednutrients from soil adnd water .

Question 17

How is desert interdependent (2)

Answer 17

-vegetation roots stblising sandys oils in semi-arid areas t edges of desrts .
Plants stop soil being blown away by wind .
-Unsustainable human use of derst threatens interdoeendnece betwene physical environment and people

Question 18

An opportunity in Mojave desert ? (tourism)

Answer 18

Las Vegas
-Tourist western desert most important source ofi income .
-National parks like Joshua tree visitors get a chance to expereicne wilderness area .
-economy built around Entertainment attracting 37mil visiotrs yearly .
-Two major lakes creted ater mangement lake lead and powell , offer water skiing saling attarct two mil .

Question 19

Energy Opoortunity in Mojave desert

Answer 19

-Strong insolation good opportunity for solar power .
-Sonoran solar porject new porject to produce energyf or 100k homes anf requried 360 builders to build .
-HEP also supply Western desert with some electricity , powered by leak mead .
-Fossil Fuels - 25 acitve oil sites have expoloited this economic opportunity for beenfit of local Navajo eople more than 10 employess porduce oil worth 50 mil .

Question 20

disadvnantage of energy produciton

Answer 20

-Power stations require a water supply nearby
-disruption to habitaton of Mojave desert tortoise

Question 21

minereal extration opportunity in deserts

Answer 21

-Western desert rich in minerals like uranium and copper . Grand canyon uranium mining plann .
disavanages
-uranium radiactiivty risk to wildflie , contamination of water
lack of wter for mining .

Question 22

farming opportunities in deserts

Answer 22

-High temp and sunlight generally fabourabl for agriculture , water found through irrigation two importantion sourceof irrgartion water :
AQUIFIERS store large stores of water beneath hot desert l Rainwater goes ointo permeable layer trpped found by digging a well . good for veg and wine aquifiers.
CANALS - usd for large scale industrialised agriculture farmers allcoated 80 percent Colarado water but rthey only make ten percent of economy .

Question 23

how accesiblity a challenge in desert ?

Answer 23

-Low popualiton density means part o western desert llack surface roads . Tourissts and exporers must find thier own way around , extreme temperatrues amke it daneorus if brekasd own ,2015 elderly tourist died of dehydration .

Question 24

how have people dpted to climte

Answer 24

-lat roofts to colerct rainwater
-whitewash walls to reflec sunlgiht snd kee[ biuilidnngs cool
-cowboy hats to prevent sun burn
-fake grass in pitches drought resitant

Question 25

Benefits of taking water to the western desert .

Answer 25

-Colardo rivers Brings water to 5 major ciities thorugh western desert area . In the coahclela valley , water is extrcted from awuiferd to grow crops such as ppers nd grapes .
-Irrigation water from Lae Mead is used in farming .

1.4 mil irrigated land thorugh colardo river produces 15 percent of usa crops and 13 percent of its livestock . Total agricultural benefits calcualted to be 1.5bil per year .

Question 26

Drawbacks of taking water to the western deserrt

Answer 26

Hoover canyon damn , slit gets trapped between both of dams , makes water in dam colder , silt heats up in sunlight warming wter around it, so a river ecosytems changed many species lost .

Question 27

Issues of water supply and population growth in the western deserft .

Answer 27

-lready 30 million in sw usa depend on water .
Phonexi takes amximum shre water allowed but rapid poulaitongrowth in severalstates , more gthan double national average .
-There is a hsycial limit to how much water can be taken form the Colarado despite populaiton grrwoth . Also a political limit too because of an intenrtional agreemnt where says water has to flow to mexico where oclarado ends .

Question 28

Other problem . of issues of future water supply

Answer 28

-Threatened by climste change
reduced rinfall could occur in places where water is already svvarce .
2100 annual temp could be five dergree higher predicted combination of changoin climate and rr apid populaiton growth means even mroe wate scaarcity in future .

Question 29

What is desertification

Answer 29

-The spread of desert into neighbouring semi-desert (arid) areas usually due to sioil degradation .
Found at the edge of deserts

Question 30

what are desert fringes

Answer 30

demi deserts semi arid reas aka ,, has fairly predictable rain fall in some places making settled agriculture possible . more dorught reistant tess and grsses grow in higher rianfall desrrt fringe .

Question 31

problem with desert fringes

Answer 31

-despite high rainfall , they re classfied as fragile environemnts , catastrophic ecological and environmental consequnces can be causd by climate change , oor land amangement , so fringes at constant risk of desertifiscation .

Question 32

global wrming and desertfication

Answer 32

-Sahel , LIC country , desertification greatest so little money and tehcnology cannot tackle problem ,
Global warming - decli.ene rainfall even fruther so becomes drier leading to sand dune system over valuable crop land
sahel
but africa has flucutaing rainfall cycles so some think global warming coul icncrease rainfall aswarming oceans ass more water vapour into atmosphere

Question 33

Population growth and desert fringes

Answer 33

-population very high in poor parts of shael , Lack of education , growth due mroe children born .
-MITIGATION - droguh and desertfication in one region displaces people to another environemnt . -Desertication occurs htere too and as number of people increase , problem gests pread place place to place addition to climate change refugees , millions havefbeen forced to move to desert fringe areas by armed conflicts in sahelregion .

Question 34

how is climate change a cause of desertification ?

Answer 34

-CYclical droguht bringing lower and less reliable rianfall
-Gloabl warming causes irisng temperatures .

Question 35

How is population growth causes of desertification

Answer 35

-High fertility among local people
Refugees arriving from conflict zones .
-Extreme poverty .

Question 36

How is pressure on resoources cuase of deserticiation ?

Answer 36

-Overgrazing byc attle ,
more wood uesed for fuel and shelter
overuse of aquifiers
soil erosion .

Question 37

desertification problem in Sudan

Answer 37

-environemnt under a lot of pressure one in five years drought , crop failoure and livestock loss to sudan
-sahel’s ability to produce food has not kept pacee with its growing populaton ,
-environemtn major conflict , farmers fighting over land wad water supplies , herders dleiebrately redtrcitd for water supplies leadigng to cattles overgazing , once vegation gone cattle died , in revenge , hrders chases farmer dfrom homes and cut down crops and trees . (OVERGRAZING huamn cuase of desertification PROBLEM )

Question 38

overcultivaiton human cause of desertification explained

Answer 38

vercropping exhausts lands fertlity , more childern born into framing familis surviving infancy , so more lants and quifiier sused drained dry , European companies using large areas of frgaile land in Ghana grow water hungry cash crops like veg oil .

Question 39

soil erosion human cause desrtification

Answer 39

-overcutlivgion , soil erosion ,vegation eaten by cattle or killed by drought exposed top soil becomes hard by hstrong insolation , rain wahses over soil rather than soaking it as it flwos carriers top soil aay , soil eroded , vegetation cannot grow back .

Question 40

tacking desertificaiotn - management measures can help reserve soil quality

Answer 40

-Tree-planting schemes to bind and protect the soil .
-Planting gtass on slopes to help stablise top soil .

Question 41

desrtifcation - reserving water supply

Answer 41

-collecting rainwater on roofs by desinging a flat roof with a surrdounding lip .
-builindg terraces on farmed slopes.

Question 42

technology desertificaiton tackling .

Answer 42

toyola cookstoves - isnted of pile of woods , causes deaths and relaly bad popualtion and oak fires nead loads of wood so fixes deforestation more sustainable , so much m ore efficent . Made of scrap metal , really cheap .
stone lines -tsone washed downhill by rain slowed down by tone lines and trapped , damp soil can grow things in it or dig it up .

Question 43

planting trees help stop desertification

Answer 43

tree roots stabilises the soil , and while decomposing leaf litter adds valuable nutrients making planting of trees a practicl way to tackle deserification .
-Green wall sgtivsn union ptopodrf to plant trees across whoel sahel region m, hoping for sutaible develpment in communities ,
-More secutr ptojrvt geenrtes work opportunity for desperate poor , and reduce conflict ewith refugee camps which contribute to desrtifcation .

Question 44

disadvanatge of trees to stop desertification

Answer 44

icreased aridity may threaten survival of trees in the long term .