hot deserts (p1) 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
what is overgrazing
grazing too many livestock for too long on the land so it is unable to recover
what is over-cultivation
exhausting the soil by over cropping the land
what is aridity
an area receiving less than 250mm of rainfall per year
3 characteristics of a hot desert
aridity
40+ degrees
towering dunes landscape
definition of a desert
an area receiving less than 250mm of rainfall resulting in extreme aridity
where do most deserts lay
in general, most lie between tropics of cancer and capricorn
why are the worlds located where they are
- air is dry near tropics
- leading to areas of high pressure
- results in no clouds
- therefore hot in the day and cold at night
what is soil like in deserts
dry and infertile, lack of organic material
how to describe temperatures in deserts
high diurnal range
what is interdependence
animals and plants in the same ecosystems relying on each other for survival
how do plants affect soil
- roots tie soil together
- intercepts rainfall
- help retain water by providing shade
- provide extra nutrients through dead vegetation and fixing chemical
how does soil affect plants
provides nutrients
how do humans affect interdependence negatively
- disturb the food chain by over hunting a species
- disrupt soil making it more susceptible to erosion when wet
- trample plants so cant grow
how do humans affect interdependence positively
plant more plants to increase food for primary consumers
what reduces biodiversity in deserts
- dry conditions
- high temperatures
- short periods of rainfall
what are plants that can live in dry conditions called
xerophytes e.g. cactus
how are xerophytes adapted
thick, waxy cuticles and shed leaves to reduce transpiration
how are fennec foxes adapted to hot temps
- large ears to help dissipate excess heat
- sandy fur reflects heat and insulates them at night time
- kidneys restrict water loss
how are peringuey adders adapted to hot temps
move sideways so less than 50% of their body is in contact with sand
CS: western desert specifics farming
coachella grows vegetables by absorbing water from aquifers
CS: western desert specifics mineral extraction or energy generation
- 100,000 homes from solar, 360 workers
- HEP employed 5000 people
- 25 active oil sites
CS: opportunities of tourism in western deserts
- crucial source of income from national parks, busems, culture
- 2 lakes have been built
CS: opportunities of farming in western desert
- irrigation
- aquifers produce large fields of lush crops like lemons, peppers and grapes
CS: challenges of farming in western desert
- rain and groundwater can seep into permeable layer of an aquifer and become trapped
CS: opportunities of min extraction/energy generation in western desert
- rich in minerals that aren’t all exploited
- new solar plants
- HEP plants
CS: challenges of min extraction/energy generation in western desert
- conflict over other land use
- uranium used in nuclear power plants
- fossil fuels - drilling for oil
challenges of developing in desert areas
- population density
- inaccessibility
- extreme temperatures
- water supply
how to overcome high temperatures
- houses have thick walls to keep cool air in day but warm at night
- white washed walls to reflect sun
challenges of high temps
- hard work outside
- climate change - only getting hotter
- average temp of 27 degrees
- high rate of evaporation - water shortages
challenges of growing population
- not enough water to share
challenges of inaccessibility
- low pop density so no surfaced roads
- away from main city
how to overcome inaccessibility
- build more roads like route 66
- major cities can be reached by air
challenges of water supply
- conflict over colorado useage
- climate change will increase issue - lake mead decrease
- agriculture
- increased demand due to population growth
how to overcome water supply
- remove grass from homes
- grow drought resistant crops
- use dams and reservoirs like Hoover dam
desertification cycle
- amount of natural veg decreases
- no plants or leaves to intercept
- sun bakes soil and cracks it
- rainwater runs over the surface rather than soaking in the soil
- soil is washed away
- soil degrades losing fertility and structure so cant grow crops
causes of desertification
- increase population of semi desert areas
- land farmed more intense
- animals graze at higher stock
