Murray darling - salinisation

Question 1

Causes of salinisation

Answer 1

• A lot of the country was under water many years ago so salt in the soil
• Shaped like a basin in the middle so when rain contains salt it can’t drain out
• Deforestation and agriculture makes the water table rise

Question 2

Effects of salinisation

Answer 2

• Losing farmland
• When vegetation lost, erosion occurs
• If it continues won’t be able to feed the population
• High food prices
• Roads need 4 times amount of maintenance when water table high

Question 3

How does irrigation cause salinisation

Answer 3

• As water passes over soil it dissolves minerals and nutrients
• If too much irrigation can lead to waterlogging which frees salts that have been washed down by rain water
• Many goof farmlands are ancient sea beds so lots of salt
• Rise to surface and reduce crop productivity