Water Cycle Case study - Megadroughts in California

Question 1

What is a megadrought?

Answer 1

A megadrought are defined more by their duration than their severity. They are extreme dry spells that can last for a decade or longer.

Question 2

What are the environmental impacts of the drought?

Answer 2

Environmental:
* About 1000 more wildfires than usual have occurred.
* Prolonged drought threatens wildlife.

Question 3

What are the causes of the current drought?

Answer 3

Causes of the current drought
- In normal winters, southwest winds from the ocean deliver water. Recently, for unexplained reasons, these
winds have failed California.
- Tree ring studies: Very little of the California drought can be attributed to climate change with any certainty.
- Cooler water temperatures – known as La Niñas – tend to produce drier conditions in the west. El Niño
conditions would cause above average rainfall.

Question 4

What were previous droughts in California?

Answer 4

Previous droughts
- Dust bowl (1930s) – Spanned 8 years in certain parts of the great plains. It was the worst American drought in the last 300 years, causing mass migration westward.

• Great plains drought (1950s) – At its peak in 1954, it covered 62% of the country.

Question 5

What are the economic impacts of drought in California?

Answer 5

Economic:
* Last year, farmers harvested 640,000 fewer acres, but crop revenue remained strong.
* Farms have adopted more efficient water management technologies.

Question 6

What are the social impacts of drought in California?

Answer 6

Social:
* Water shortages and restrictions.
* Competition over water supply for agriculture, domestic use and aquatic ecosystems – could escalate to conflict over water use.
However, water supplies were really stocked up prior to the drought, easing the situation.

Question 7

How does drought affect California?

Answer 7

Impacts
* California is in the third year of one of the worst droughts in the past century.