Amazon Rainforest Water Cycle and Human Impacts

What is the average rainfall in the Amazon Rainforest?

Greater than 2000 mm/year, mostly from convectional rainfall.

What percentage of precipitation is intercepted in the Amazon Rainforest?

10% of precipitation.

How much water is evaporated from intercepted water in the Amazon?

20-25% of intercepted water.

What is the annual rate of evapotranspiration in the Amazon Rainforest?

7.2 gigatonnes/year, returning 50% of rainfall to the atmosphere.

How much water does one tree in the Amazon transpire daily?

100 gallons/day.

What is the total annual transpiration from one tree in the Amazon?

760 litres/year.

How much water does the entire Amazon forest transpire to the atmosphere annually?

Approximately 76,000 litres/year.

What is the average river discharge from the Amazon into the Atlantic Ocean?

60 million gallons/second.

What geological factors influence the water cycle in the Amazon Rainforest?

Crystalline rocks (impermeable, fast runoff) and sandstone/limestone (porous, more infiltration/storage).

How does the relief of the land affect water flow in the Amazon?

Lowlands promote overland flow and throughflow, while the Andes' steep terrain leads to fast runoff.

What is the temperature range in the Amazon Rainforest and its effect on evapotranspiration?

High temperatures (25-30°C) lead to high rates of evapotranspiration.

What human activity accounts for 60% of deforestation in the Amazon?

Cattle ranching, which provides 80% of Brazil's beef.

What is the impact of deforestation on the water cycle in the Amazon?

Increased runoff, decreased interception, evapotranspiration, and storage, leading to higher flooding risks.

What is the effect of the Tucuruí Dam on the Amazon Rainforest?

It flooded 2,250 km² of forest.

How do roads and mining affect the water cycle in the Amazon?

They increase impermeable surfaces, leading to increased runoff and pollution.

What is the significance of rain recycling in the Amazon Rainforest?

The Amazon generates 50% of its own rainfall.

What are the storage characteristics of soils and aquifers in the Amazon?

Deep tropical soils store large volumes of water.