Fresh Water Resources

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Fresh Water Resources
Water - Basic Knowledge
Made up of 2 hydrogen and one oxygen
We can live without food for 50-60 days, but we can only live without water for 1-2 days (3 at most) Water resources are scarce
Life without water is why we don't live on mars
Hydrologic cycle
Describes the continuous movement and distribution of water on, above, and below earth's surface By changing its state, water moves among great global reservoirs 3 stages: gas, liquid, solid (ice)

When solid, it expands to a crystalized structure that's less dense than liquid water, causing it to float  

 
 
Global Flux: 577,000km3 of water moves annually
 
Inputs = outputs
By looking at three global states
I=O
 
Inputs| Outputs|
Precipitation(to oceans and continents)| Precipitation(from atmosphere)| Evaporation(to atmosphere)| Evaporation(from ocean and continents)| Run off (to oceans)| Run off (from continents)|

 
How much water moves between the stores?
Residence time = how long water stays in a store
 
Ocean: 3200 years
Deep groundwater: 10,000 years
Atmosphere: 9 days
 

 

 
What do we use water for?
Drinking
Washing
Showers
Cooking
Industries
Making beer
….pretty much everything
 
How much water do we have?
Freshwater: 2.78%
Ocean: 97.22%
 
Too much water
Floods
Hurricanes
After winning a football game?
 
Some people in the least developed countries have to carry water for a couple miles to their homes Droughts
Polluted water
 
Save water, drink beer?
Maybe not, it can take 60-100L of water to make 1L of beer
 
By 2025, 3 billion people will have water stress of shortages  
World Problems
Availability of fresh water
Availability of clean, fresh water
Distribution of this
THERE IS NO ALTERNATIVE FOR FRESH WATER
Poor vs rich countries
Dam construction
 
Case Study: Mexico City
Located in the central part of the trans-Mexican volcanic belt About 7,500km2
Basin altitude: 2,200m about sea level...
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