hot deserts

Question 1

what are methods of reducing desertification?

Answer 1

• water management - growing crops that need little water can reduce water use
• drip irrigation on crops - means soil isn’t eroded by lots of water being added all at once
• tree planting - trees can be planted to act as windbreaks - reducing wind erosion
• soil management - leaving areas of land to rest in between grazing or planting them lets them recover their nutrients
• appropriate technology - involves using cheap. sustainable, and easily available materials to build things easy for local people to maintain

Question 2

how are plants adapted to cope with hot + dry conditions?

Answer 2

• plant roots can be extremely long to reach deep water supplies
• many plants succulents - have large fleshy stems for storing water + thick waxy skin to reduce transpiration
• some plants have small leaves to lower surface area to reduce transpiration
• some plants only germinate after it rains + grow quickly it make most of wet conditions

Question 3

how are animals adapted to cope with high temp + limited water?

Answer 3

• nocturnal animals stay cool when sleeping when hot
• many desert animals have long limbs giving large SA to lose heat from
• lots of animals live in underground burrows - temps less extreme
• some bigger animals store fat that they break down into water (camels)
• some animals get water from their food
• most desert animals minimise water loss through sweat + urine

Question 4

what are the causes of desertification?

Answer 4

• climate change - reduce rainfall and rising temperatures have meant less water for plants
• fuelwood - people rely on wood for fuel - removal of trees causes soil to be exposed
• overgrazing - too many animals mean plants eaten faster than can grow back - causing soil erosion
• over-cultivation - if crops grown in same areas too often - nutrients in soil will be used up - causing soil erosion
• population growth - a growing population puts pressure on the land leading to more deforestation, overgrazing and over-cultivation

Question 5

what is desertification?

Answer 5

means turning of drylands into deserts

Question 6

what are opportunities for development in the sahara desert?

Answer 6

• mineral extraction - morocco world’s largest exporter of phosphate - holds 75% of worlds phosphate reserves
• tourism - many people fascinated by remote + exotic desert locations
• energy - Algeria is a leader in oil exploration + extraction in the Sahara - 60% of Algeria’s income from oil & gas industry - solar energy can be exploited in Tunisia because Sahara receives 12 hours of sunlight per day
• farming - water essential for plant growth so commercial agriculture in Sahara only possible where enough irrigation of water

Question 7

what are challenges for development in the Sahara?

Answer 7

• extreme temperatures - Sahara’s temp can reach 40C during day and can drop to below 0C at night - can cause illness/death - often too hot for tourists so people with job only work some months
• water supply - low annual rainfall - most rivers only flow for part of the year - difficult to provide water for workers, industry + irrigation
• accessibility - sahara huge - providing services hard - only a few roads - people + material have to travel long distance - air - expensive