Salinisation Case Study - Aral Sea, Kazakhstan (EDC)

Question 1

What is salinisation?

Answer 1

A form of land degradation in arid climates where soil quality is reduced, mostly due to high salt levels.

Question 2

What are the two causes of salinisation?

Answer 2

• Water from irrigation moves to the surface by capillary force and evaporates, leaving a salt pan (soil layer) in the top soil.
• In coastal areas, excessive groundwater withdrawal can cause saline water to infiltrate freshwater supplies.

Question 3

Where is the Aral Sea located?

Answer 3

Between Kazakhstan and Uzbekistan.

Question 4

How much global irrigated land has had reduced productivity due to salinisation?

Answer 4

The FAO shows that up to 20% has had reduced productivity.

Question 5

How much has the volume of the Aral Sea decreased?

Answer 5

It has decreased 90% from its original volume.

Question 6

What three methods can be used to control water levels in areas vulnerable to salinisation?

Answer 6

• Utilising drip irrigation.
• Monitoring soil moisture levels.
• Planting and maintaining trees and shrubs.

Question 7

What four changes to farming processes could be implemented in areas vulnerable to salinisation?

Answer 7

• Using a crop rotation system and ‘break crops’ to reduce fallow periods (periods where no crops are planted).
• Maximising soil surface cover by planting multiple crops.
• Introducing salt-tolerant crops such as barley or sugar beet.
• Planting deep-rooted plants.

Question 8

What three methods could be used to reduce soil degradation in areas vulnerable to salinisation?

Answer 8

• Avoiding over-tillage.
• Mulching exposed ground.
• Managing the fertility, pH and structure of the soil.