Hot deserts Flashcards
Location of Hot deserts
30N or 30S of the equator
Just by the hadley cell
What is the definition of a desert
A desert is an area that receives less than 250mm of rainfall per year.
Reasons for climate of hot desert
-Air is sinking near the tropics
-Leading to areas of high pressure
-This results in fewer clouds
-Therefore temperature is hot during day and cold at night due to lack of cloud cover
How hot are deserts during the day and night
50C in the day and below 0C at night
Relationship between plants and soil
-Vegetation provides cover for soil and food for animals
-Soil provides the structure for roots to take hold and grow
How has a saguaro cactus adapted to conditions
-They can store up to 9 tonnes of water
-They grow really slowly to preserve energy levels
-Can lose 82% of water before dying of dehydration
How have roots adapted to conditions
-To make most of sudden rainfall some roots are very shallow and cover a large area
-Some roots go deep in search of water (25m)
Case study for Hot deserts
The Western desert
Location of western desert
-Made up of 3 smaller deserts: Mojave, Sonora and Chihuahuan.
In Arizona, New Mexico and Nevada, USA
Opportunities in the western desert
Energy generation, Farming, Tourism, Mineral extraction
Reasons for tourism in WD
-Many people want to visit the national parks and wilderness areas, to experience a new part of the world
Challenges of Tourism in WD
-Lack of access as there is a lack of infrastructure
-Extreme heat and lack of water affect tourists and their accessibility to Western Desert
Reasons for farming in WD
-High temp and sunlight is favourable for irrigation
-Xeriscaping , using drought resistant plants to store water
Challenges of Farming in western desert
-Water droughts occur a lot in desert areas, no rainfall results in dead crops and plants.
Reasons for Mineral extraction/Energy generation in WD
-Western desert is rich in minerals - copper mining happening for years
-Lots of space and lots of sunlight for solar energy
Challenges of Mineral Extraction/Energy generation in WD
-Lack of water discouraging large scale mining
Why is temperature a challenge
-Extreme temperatures over 50C lead to high rates of evaporation and water shortages
How many people depend on water from Colorado river
30 million people
How to overcome the extreme temperatures
-Implement flat roofs in houses to collect rainfall
Give an example of lack of water being a challenge
-Nevada’s water deficit - lack of freshwater from Colorado river
How to overcome lack of water supply
-Xeriscaping, gardens using drought resistant plants
-New developments in Las Vegas turning 50% of grass in gardens to cacti to store more water
Give an example of inaccessibility being a challenge to the WD
-There is a lack of roads in Western desert due to low population desert
How to overcome challenge of inaccessibility
-Las Vegas has 4 airports with 38.8 million tourist arrivals
-Southwest airline does 118 routes to Las Vegas increasing tourism
Why is long term water security needed
-Increasing population growth and demand for water threatened by climate change
How to ensure there is long term water security
-Storing water in reservoirs
-Large bodies of water such as Lake Mead reduce evaporation
What is desertification
The process of land becoming drier and degrading in quality due to both human activities and natural processes
Why is vegetation so important to soils
Vegetation provides shade for soils preventing it from too much exposure to the sun
-It also provides interception for rainfall making the impact on soil softer so the nutrients aren’t washed away
Example of an area where desertification is occurring
The Sahel desert
How is the Sahel solving desertification
The great green wall- 15km long band of trees and shrubs across the southern border of the Sahel
Info of the great green wall -
-Spans through 11 countries in Africa
-The project is seen as a way of restoring land back to productivity.
Strategies to reduce risks of desertification
- Afforestation
-Soil and water management
-Appropriate technology
How does afforestation reduce desertification
-Prevents the ground drying out therefore soil erosion is prevented meaning vegetation can be planted
How does soil and water management reduce desertification
-As it is cheap meaning locals can do this, stone walls trap soil so it isn’t eroded
-Soil erosion is prevented
-Less water is lost through surface run off
How does using appropriate technology reduce risk of desertification
-Reduces need to cut down trees for firewood as there’s fuel efficient stoves
-There is more vegetation and reduced deforestation.
However this can be really expensive
