Deserts Flashcards
What is mineral extraction?
The removal of solid mineral resources from the earth
What is desertification?
The process by which land becomes drier and degraded, as a result of climate change or human activities or borth
What is over cultivation?
Exhausting the soil by over cropping the land
What is soil erosion?
Removal of the top soil faster than it can be replaced
What is aridity?
The state or quality of being extremely dry
What is diurnal temperature range?
The difference between the maximum and minimum temperatures within one day
What is irrigation?
Artificial process of applying controlled amounts of water to land
What is carrying capacity?
The maximum number of people an area of land can support before environmental damage occurs
What is water security?
The reliable availability of acceptable quantities and quality for people to live off
What is a desert fringe area?
Borders of hot deserts that support greater biodiversity - despite higher rainfall they are still classified as fragile environments at constant risk of desertification
What is a desert?
An area receiving less than 250mm of rainfall a year resulting in extreme aridity
Where are deserts found?
Between 15 and 35 degrees north and south of the equator
What pressure are deserts in?
High - where air is falling
This is due to warm air rising, then dumping its moistures on the equator, so by the time it reaches deserts it is dry and cool
Why can temperatures fluctuate so much in deserts?
Due to the lack of cloud cover
What is soil like in the desert?
Dry
Not very fertile
How much of the earth is deserts?
1/3
What are challenges in the desert?
Dry conditions
High temperatures
Short periods of rainfall
What can rainfall in a desert lead to?
Desert bloom - higher biodiversity
How are camels adapted to deserts?
Can go a week or more without water + months without food
Store fat in the hump for energy
Body temperature fluctuates throughout the day
Feet a wide
Thick lips
Ears are covered
What opportunities are in deserts?
Tourism
Golf
Farming
Mineral extraction
Energy generation
What sates does the western desert cover?
Nevada
Utah
New Mexico
California
What tourism opportunities are there in the western desert?
Grand Canyon
Joshua tree national park
Native Americans
Las Vegas
Lake mead + Powell
What farming is there in the western desert?
Coachella valley in CA produces lush vegetables using aquaifiers
What mineral extraction is there in the western desert?
Uranium mining near Grand Canyon
Copper mining in Ajo, AZ
What are the challenges of developing in desert areas?
Climate change
Climate
Water supply
Transport + accessibility
Why is climate change an issue in the western desert?
2014 lake mead reached a record low
Projected to warm faster than the rest of the world
By 2100 the annual temp is expected to be 5 degrees higher than 1970
Would lead to more water scarcity
Why is climate an issue in the western desert?
Working outside is very hard
High temperatures lead to evaporation - increased water shortages
Plants and animals have to adapt to survive
Why is water supply an issue in the western desert?
30 million people depend on water from the Colorado river
Physical limit to how much water can be taken
Political issues - must allow water into Mexico
Can lead to conflict between states/countries
Why is transport and accessibility an issue in the western desert?
Lack of surfaced roads
Route 70 -> Utah
Route 66 Chicago through Cal
Development can be difficult
2015 tourist died after car broke down
Why is vegetation vital for the protection of soil in desert?
Gives shade - prevents it from drying out quickly
Roots give structure - provide integrity to prevent erosion
Intercepts rainfall - prevents nutrients being leeched away
Where is the Sahel?
Region stretched across central Africa (south of the Sahara)
Why is population growing in desert fringe areas?
Birth rate increasing
Migration from people seeking refuge from drought and war
How can desertification be caused?
Over cultivation
Overgrazing
Soil erosion
Deforestation
Population growth
What are the strategies to reduce the risk of desertification?
Water and soil management
Tree planting
Use of appropriate technology
How does water and soil management help decrease the risk of desertification?
Bund line of rocks interrupts the flow of water
Any soil carried is deposited at the walls
So this can be cultivated
How can tree planting reduce the risks of desertification?
Protects the soil from rain and provided shade
Great Green Wall - planting trees from southern edge of the Sahara
How can appropriate technology prevent desertification?
Alternative cooking derives use less wood - so deforestation decreases
