Hot Deserts Flashcards
What makes a desert ?
-Anywhere on Earth receieving less than 250 mm of percipitation yearly . Percipitation extremely unreliale .
-Extremely aird places , not always hot .
Where are Deserts found ?
-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 .
What is the meaning of a diurnal temperature rnage ?
Extremely hot in the day and extremely hot at night .
Why does the desert have a large diurnal temperature range ?
Cloudless skies allow high levels of insolaion in the day time whic also permits heat loss at night .
Why is there a lack of cloud and rain in the desert ?
-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 )
Explain Hot desert soils
-Due to hot climate soil-forming processes are limited by shortageopf water .
-lack of vegetation so little organic matter
Explain irrigated Hot desert soils
-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 .
How have plants adapted to dry conditions ?
-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 .
How have plants adapted to high temperatures ?
-Some plants have the bulk of their biomass below the ground surface where temperatures are cooler .
How have plants adapted to short periods of rainfall
deserts bloom suddenly after rainfall so to complete their life cycle quickly .
How have animals adapted to the desert ?
-adpated to the hot tepm ad cold night shoratge of water .
-Mmany creatures avoid sun spednign days under stones and are nocturnal .
How do animals tackle water issue ?
-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 .
How do animals catch prey ?
-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 .
wht are the bioitic parts of the desert
plants and animals
what are the abiotic parts of the desert
soil , underlying rocks adnd water supplly .
How is desert interedependent
-interdepenendency betwene biotic and abiotic shown by different parts of food web animals eating plants that have gainednutrients from soil adnd water .
How is desert interdependent (2)
-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
An opportunity in Mojave desert ? (tourism)
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 .
Energy Opoortunity in Mojave desert
-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 .
disadvnantage of energy produciton
-Power stations require a water supply nearby
-disruption to habitaton of Mojave desert tortoise
minereal extration opportunity in deserts
-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 .
farming opportunities in deserts
-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 .
how accesiblity a challenge in desert ?
-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 .
how have people dpted to climte
-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
