Hot deserts

Question 1

What are the opportunities of the Sahara desert

Answer 1

mineral sources, oil and gas, solar energy, tourism, farming

Question 2

What are the challenges of the Sahara desert

Answer 2

extreme temperatures, inaccessibility, water supply

Question 3

Why is solar energy an opportunity

Answer 3

12 or more hours of bright sun, lots of space, Tunisia is planned to turn 100km2 into solar energy development

Question 4

Why is tourism an opportunity

Answer 4

help more job opportunities, more income

Question 5

Why is farming an opportunity

Answer 5

lots of space, remote villages can earn money by selling crops and animals

Question 6

Why is extreme temperatures a challenge

Answer 6

lack of cloud cover, high temp - illness, tourists won’t visit if too hot -seasonal

Question 7

Why is inaccessibility a challenge

Answer 7

huge, people and supplies travel long way, expensive, takes a long time to transport materials

Question 8

Why is water supply in the hot deserts a challenge

Answer 8

low annual rain fall, providing water for workers, industry or irrigation is very hard, collecting water from underground is not sustainable

Question 9

What are the characteristics of a hot desert

Answer 9

climate, soil, plants, animals, people

Question 10

Climate - hot deserts

Answer 10

very little rainfall - les than 250 mm a year, temperatures are extreme they range form very hot in the day (45) to very cold at night (5)

Question 11

Soil - hot deserts

Answer 11

usually shallow with a coarse gravelly texture, hardly any leaf fall so not fertile, lack of rainfall and plant material means the soil is very dry

Question 12

Plants - hot deserts

Answer 12

plant growth is pretty sparese due to the lack of rainfall, the plants are usually short and have a short life cycle only appearing when it rains

Question 13

Animals - hot deserts

Answer 13

animals have adapted to survive in the harsh environment, mammals tend to be small and nocturnal

Question 14

Poeple - hot deserts

Answer 14

many people living in the desert grow a few crops where there are natural springs or wells to supply water, some people travel all the time in search of food and water for their herds of sheep or goats

Question 15

What is the ecosystem like in a hot desert

Answer 15

plants gains their nutrients and water from the soil which are passed on to animals, animals spread seeds, only low-density populations can live as there is sparse food supplies, little decomposition of dead plants as it is hot and dry, little water supply, people have to collect water for plants from wells which reduces the water available for plants meaning animals and plants struggle to survive

Question 16

Example of how changing the components of the desert can affect it (overgrazing)

Answer 16

e.g. allowing cattle to overgraze means that there are not plant roots to stabiliser the soil and wind can blow away soil/sand which leads to soil erosion this means clouds of dust are produced which can change the climate of the deserts reducing rainfall

Question 17

Where is there highest biodiversity in the hot deserts and how is biodiversity decreasing

Answer 17

near water, temporary ponds/rivers have high biodiversity, areas with water also have the highest population of humans but human development threatens biodiversity by desertification and over-using water supplies, climate change means that some animals cannot cope with the increasing temperatures so are at risk of extinction especially if they are unique to the deserts

Question 18

Desertification definition

Answer 18

degradation of land so that is becomes drier and less productive, soil erosion is a key part because soil that is exposed is easily removed by wind and the nutrients of the soil are lost making it infertile

Question 19

What are the causes of desertification

Answer 19

climate change, human activites

Question 20

Why is climate change a cause of desertification

Answer 20

rainfall - reduced rainfall means there is less water for plant growth and plant roots hold together the soil meaning that it would become easily eroded, temperatures - increased temperatures mean more water evaporates making the soil drier so plants will die

Question 21

Why is human activites a cause of desertification and why

Answer 21

removal of fuel wood - many people in dry areas rely on wood for cooking and the cutting of trees means soil is exposed, overgrazing - too many cattle eat plants faster than they can regrow so more soil erosion and trampling by animals, overcultivation - if crop are planted in the same area continually all the nutrients are used up and plants can no longer grow in the soil so soil erosion increases, population growth - increases deforestation, overgrazing and overcultivation

Question 22

How can the risk of desertification be reduced

Answer 22

water management, tree planting, soil management, appropriate technology

Question 23

How can water management reduce the risk of desertification

Answer 23

growing crops that do not need much water can reduce water usage, using drip irrigation on crops means soil isn’t eroded

Question 24

How can tree planting reduce the risk of desertification

Answer 24

trees be planted and act as windbreaks to protect the soil, it also stabilises the sand to prevent the desert encroaching on farmland, growing trees near crops also provides shade which reduces temperatures and evaporation rates

Question 25

How can soil management reduce the risk of desertification

Answer 25

leaving areas of land to rest in between grazing or planting lets them recover their nutrients, rotating crops that use different nutrients from the soil means that the same nutrients do not keep being removed, compost can be used to add extra nutrients to the soil

Question 26

How can appropriate technology reduce the risk of desertification

Answer 26

using cheap, sustainable and easily available materials that are easy for local people to maintain, e.g. sand fences can be made to reduce soil erosion, solar cookers can use the sun and reduce deforestation