Unit 4: Water, Food Production Systems & Society Flashcards
What are 4 reasons why water is important?
- keeps us alive
- moderates climate
- sculpts land
- removes and dilutes wastes and pollutants
How does water sculpt land?
erosion
What percent of the earth’s water supply is available to us as liquid freshwater?
1%
What percent of all water is saltwater?
97%
What percent of all water is freshwater?
2.6%
What percent of freshwater is frozen? (for now)
68.7%
What percent of freshwater is groundwater?
30.1%
What percent of Earth’s total water volume is available on the surface in lakes, rivers, and swamps?
0.3%
If 2.6% of all water is fresh, then why is only 1% of the earth’s water supply available to us?
2/3 of freshwater is frozen, so we cannot use it
What percent of the total Earth’s water volume is water vapor in the atmosphere?
0.001%
If all of the water in the atmosphere rained down at once, to what depth would it cover the ground?
2.5 cm
When is a resource renewable?
a resource is renewable if it is replenished on a human time scale
How long does it take a molecule of water to enter and leave a river storage?
12-20 days
How long does it take a molecule of water to enter and leave an atmospheric storage?
9 days
How long does it take a molecule of water to enter and leave a groundwater storage?
up to 300 years
How long does it take a molecule of water to enter and leave an ice cap storage?
16,000 years
How long does it take a molecule of water to enter and leave an ocean storage?
37,000 years
How can water easily go from being a renewable to a non-renewable resource?
poor management
Which water storages are renewable?
atmosphere and rivers
Which water storages are non-renewable?
oceans and icecaps
What water storage is a middle ground (either renewable or non-renewable)?
groundwater aquifers
What is the water cycle powered by?
solar radiation (the Sun)
What can water flows either be?
transfers or transformations
What are 5 types of transfers that occur in the water cycle?
- advection
- flooding
- surface run-off
- infiltration and percolation
- stream flow and current