Droughts in South America

Question 1

Usual rainfall:

Answer 1

Usually, moist air from the South Atlantic encounters the Andes mountain range. This forces it southward, creating a flow of moisture around the basin.
In 2014-2015, high pressure systems diverted moist air further North, causing heavy rains in Bolivia and Paraguay but dry over Brazil.

Question 2

Impacts:

Answer 2

Water rationing for 4 million people.
Brazil relies heavily on HEP for its power, so the drought caused power cuts.
In Brazil, there are high fees to drill wells. This
led to a vast number of illegal wells. In fact,
70% of wells are illegal. Illegal wells are
shallower and polluted.
The Arabica coffee bean crop was reduced, which drove global coffee prices up 50%.
By 2015, the main reservoirs had reached 5% of their capacity.

Question 3

Impacts in the Amazon:

Answer 3

Rainforests recycle 50% of their rainfall, so deforestation could trigger a positive feedback loop causing further drought.
A drying forest means reduced soil water storage and evapotranspiration. It also means that uncontrolled wildfires are much more likely to occur.
Prolonged drought causes forest stress, which could lead the Amazon to a tipping point.
The Amazon intakes 20 billion tonnes of water vapour, which is mostly released over Brazil as rain.

Question 4

Worldwide Impacts:

Answer 4

Loss of a carbon sink
Wildfires
Changes to ENSO

Question 5

The Pantanal - South America (Brazil and Upper Paraguay)

Answer 5

The Pantanal is a significant freshwater ecosystem for birds and aquatic wildlife.
The river floodplain is vital and relies on seasonal rainfall.
When the seasonal rainfalls come, 80% of the Pantanal is flooded. The wetlands retain 60% all year round.

Question 6

Impacts on the Pantanal:

Answer 6

The drought tested the resilience of the ecosystem.
There was an increase in tree mortality, which reduced habitats.
Due to routine grass burning by cattle farmers igniting the dry forest, there have also been more wildfires.