What is the distribution of hot desert biomes?
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What is the distribution of hot desert biomes?
Hot desert biomes are mostly found in a band around the Tropic of Cancer and Tropic of Capricorn, covering approximately 20% of the Earth's surface.
True or False?
Daytime temperatures in hot deserts can reach 50 °C.
True.
Daytime temperatures in hot deserts can reach 50 °C but average around 25 °C.
What is the diurnal range?
The diurnal range is the difference between the maximum and minimum temperatures within one day, which can be up to 45 °C in hot deserts.
Which factors influence the hot desert climate?
Factors that influence the hot desert climate are:
High-pressure systems.
Prevailing winds from land masses.
Rain shadows.
Define the term arid.
Arid refers to the dryness of the atmosphere or environment due to a lack of moisture or precipitation.
Define the term nomadic.
Nomadic means having no permanent home and moving from place to place.
How many mm's is the average annual rainfall in a desert below?
The average annual precipitation in a desert is below 250 mm.
True or False?
The nutrient cycle in a hot desert is rapid.
False.
The nutrient cycle in a hot desert is very slow due to the lack of moisture. Organic matter takes a long time to decompose.
Why do some animals in the hot desert have large ears, such as the Fennec Fox?
Some animals in the hot desert have large ears because the ears radiate heat helping the animal to keep cool.
State one threat to hot desert biodiversity.
One threat to hot desert biodiversity could include any of the following:
Mining.
Climate change.
Fuelwood gathering.
Name two opportunities for development in hot deserts.
Two opportunities in hot deserts may include any of the following:
Energy production (solar, wind, coal mining).
Mineral extraction.
Tourism.
Agriculture with irrigation.
Define evaporation.
Evaporation is the process of liquid turning into vapour.
True or False?
Accessibility is a challenge in hot deserts due to a lack of roads.
True.
Accessibility is a challenge in hot deserts due to a lack of roads and the need for infrastructure to withstand high temperatures.
State the meaning of subsistence farming.
Subsistence farming is a form of agriculture where farmers grow crops and raise livestock for their own consumption and survival, rather than for profit.
What is ecotourism?
Ecotourism is a form of tourism that involves responsible travel to natural areas while minimising environmental impact and supporting local communities.
What human activities occur in the Thar Desert?
The Thar Desert is known for the following human activities:
Subsistence farming.
Commercial farming with irrigation.
Tourism.
Mineral extraction.
Energy production (wind, solar, coal, oil, and gas).
Define the term salinisation.
Salinisation is the accumulation of salts in the soil due to over-irrigation and evaporation.
True or False?
The Thar Desert covers an area of over 23 000 km2.
False.
The Thar Desert covers an area of over 230 000 km2.
True or False?
There are estimated to be 175 billion metric tonnes of coal reserves under the Thar Desert.
True.
It is estimated there are reserves of 175 billion metric tonnes of coal under the Thar Desert.
How long is the Indira Gandhi Canal?
The Indira Gandhi Canal is 650 kilometres long.
Define the term desertification.
Desertification is the process by which fertile land becomes desert, typically due to a combination of natural and human causes.
True or False?
Soil erosion is a cause of desertification.
True.
Soil erosion, which leads to the loss of nutrients and the inability of plants to establish and grow, is a cause of desertification.
What is overgrazing?
Overgrazing is the excessive consumption of vegetation by grazing animals, which can lead to desertification.
State the meaning of deforestation.
Deforestation is the clearance or removal of forests or trees from an area.
What is contour bunding?
Contour bunding is a method of constructing stones or earth embankments along contour lines to help reduce soil erosion and increase water infiltration.
What is the Great Green Wall?
The Great Green Wall is a project to plant a wall of trees across the Sahel region of Africa to help combat desertification.
Why does population growth lead to desertification?
Population growth leads to desertification because it puts increased pressure on the land as people raise more animals and grow more crops, leading to over-cultivation, deforestation and overgrazing.
What is drip irrigation?
Drip irrigation uses pipes with small holes in them, which are laid on the soil next to the plants. Water slowly drips out of the holes and directly into the plant roots. This reduces water loss.
Give one way in which trees help to reduce desertification.
Trees reduce desertification in several ways, including:
The roots help to bind the soil together, reducing soil erosion.
The canopy offers shade, helping to prevent the soil from drying out and also reducing soil erosion from rainfall landing directly on the soil.
Falling leaves and branches add nutrients to the soil.
Increasing animal and insect activity helps improve soil quality.
True or False?
Changes in grazing patterns have led to increased desertification.
True.
Changes in grazing patterns have led to increased desertification.
Nomadic Maasai farmers have been forced to use smaller and smaller areas of land for grazing. This results in overgrazing, which removes the vegetation. The soil no longer has protection from the wind and rain which leads to soil erosion and desertification.