Question

based on the chart, approximately how much of the planets water is available to human beings for household, agricultural, and industrial use?

where is earths water?

total global water
oceans 96.5%
other saline water 0.9%
freshwater 2.5%

freshwater
groundwater 30.1%
glaciers and ice caps 68.7%
surface/other freshwater 1.2%

surface water and other freshwater
ground ice and permafrost 69.0%
lakes 20.9%
atmosphere 3.0%
swamps, marshes 2.6%
rivers 0.49%
living things 0.26%
soil moisture 3.8%

about 30.1%
less than 1.5%
about 96.5%
more than 2.5%
more than 10%

Explanation:

Identificar el agua dulce total disponible

$$ \text{Agua dulce total} = 2.5\% $$

Determinar la fracción accesible para uso humano

$$ \text{Glaciares y capas de hielo (no accesibles)} = 68.7\% \text{ del agua dulce} $$

$$ \text{Agua subterránea y superficial (accesible)} \approx 30.1\% + 1.2\% = 31.3\% \text{ del agua dulce} $$

Calcular el porcentaje respecto al agua global total

$$ \text{Agua accesible total} \approx 2.5\% \times 31.3\% \approx 0.78\% $$

$$ 0.78\% < 1.5\% $$

Answer:

• about 30.1%
• less than 1.5% (Correct answer)
• about 96.5%
• more than 2.5%
• more than 10%