Soil Water

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Soil Water
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Water as a Resource
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CIA Global Trends Natural Resources and
Environment(projections for 2015) Overall food
production will be adequate to feed the world's
growing population, but poor infrastructure and
distribution, political instability, and chronic
poverty will lead to malnourishment in parts of
Sub-Saharan Africa. The potential for famine will
persist in countries with repressive government
policies or internal conflicts. Despite a 50
percent increase in global energy demand, energy
resources will be sufficient to meet demand the
latest estimates suggest that 80 percent of the
world's available oil and 95 percent of its gas
remain underground. In contrast to food and
energy, water scarcities and allocation will pose
significant challenges to governments in the
Middle East, Sub-Saharan Africa, South Asia, and
northern China. Regional tensions over water will
be heightened by 2015.
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Fastest growing countries
India China Pakistan
½ the worlds total agricultural groundwater use
In India, 80 of domestic supply and 70 of
agricultural supply is from groundwater
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The water table under some of the major
grain-producing areas in northern China
is falling at a rate of five feet per year, and
water tables throughout India are falling an
average of 3-10 feet per year.
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½ Chinas wheat, 1/3 corn
Shallow aquifer largely depleted (replenishable)
Shift to Deep fossil aquifer (non-replenishable)
Agricultural well depths can exceed 1000 feet ()
Municipal well depths can exceed 3000 ft.
Levels dropping 10 ft. or more / year
Chinas grain production has fallen from its
historical peak of 392 million tons in 1998 to
an estimated 358 million tons in 2005, a drop of
34 million tons.
China largely covered the drop-off in production
by drawing down its once vast stocks until 2004,
at which point it imported 7 million tons of
grain.
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India
Population
21 million wells
water table is falling by 6 meters (20 feet) per
year
falling water tables have dried up 95 percent of
the wells owned by small farmers
drilling 1000m to reach water
agriculture is rain-fed and drinking water is
trucked in
Pakistan
Quetta
Pakistan is growing by 3 million per year, In
the Punjab plain, the drop in water tables
appears to be similar to that in India. In the
province of Baluchistan, water tables are falling
by 3.5 meters per year. within 15 years Quetta
will run out of water if the current consumption
rate continues
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Saudi Arabia
al-Disi aquifer
sandstone aquifer not subject to recharge
Shared by Saudi Arabia and Jordan
1984 Saudi national survey reported fossil water
reserves at 462 billion tons
½ has been depleted
irrigated agriculture could last for another
decade
Wheat and Soybeans
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U.S. Water
Rainfall 4,200 billion gal/day
408 billion gallons per day total
withdrawal Thermoelectric power 50 Irrigation
30 Public-supply 10 Industrial 5
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1.6-2.5 gpm
Guilty Pleasures
5-8 gpm
http//www.youtube.com/watch?vvMITcQUe-9M
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How much water do you use?
http//ga.water.usgs.gov/edu/sacsq.html
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Water Usage
Use Gallons per Capita Percentage of Total Daily Use
Showers 12.6 17.3
Clothes Washers 15.1 20.9
Dishwashers 1.0 1.3
Toilets 20.1 27.7
Baths 1.2 2.1
Leaks 10.0 13.8
Faucets 11.1 15.3
Other Domestic Uses 1.5 2.1
74 gallons
Total
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How do you conserver water?
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Peanuts
1pound 100 gal
Domestic water use 10 Industrial water use
20 Irrigation water use 70
1 pound of Rice 650 gallons 4800 pounds 1 pound
of Wheat 130 gallons 1000 pounds 1 pound of
Sugar 400 gallons 3000 pounds 1 pound of
coffee 2650 gallons 10 tons
1 beer 66 gallons
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Secondary Water
Grain Livestock
3000 gallons 11 tons 1000 gallons gt3 tons
650 gallons 2.5 tons
¼ pounder Quart of milk Pound of cheese
Carnivores consume 100 times their weight in
water each day Vegetarians consume about ½ as
much.
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Breakfast
Toast 40 gal Eggs 130 gal Milk 265
gal Coffee 37 gal Sugar 3 gal
Total 475 gal
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Yearly Totals
Drinking water 250 - 300 gallons
Total water 1500 3000 tons
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Factoids
Americans drink more than 1 billion glasses of
tap water per day. On average, 50 to 70 percent
of home water is used outdoors for watering lawns
and gardens.
Average household water use annually 127,400
gallons Average daily household water use 350
gallons
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Factoids
It takes about 4,776 gallons of water to raise a
Christmas tree. To raise the 35 million Christmas
trees U.S. families enjoy each year, a total of
167 billion gallons is required. If mothers
refresh their floral arrangements and flowering
plants during the Mothers' Day week, they will
use 2,835,000 gallons of water. After
Thanksgiving dinner in 1999, 16.4 million
Americans watched football. At halftime, American
toilets flushed 16.4 million times and used 48.5
million gallons of water. Water efficient
toilets would save us 22.3 million gallons of
water.
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Where is all the Water?
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How much water is there?
400 billion billion gallons
326 million mi3(one estimate)
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Total Earth Water 326 million mi3
688 miles
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1 cubic mile
Distance to the sun?
93 million miles
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326 million mi3
0.12 of the earths volume
Where is all this water?
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Where is all the Water?
Oceans, Seas, Bays
Wetlands, Swamps
Lakes
Soil Moisture
Atmosphere
Biological Water
Rivers
Groundwater
Ice caps, Glaciers, Permafrost
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Where is all the Water?
Water source Percent of fresh water Percent of total water
Oceans, Seas, Bays -- 96.5
Ice caps, Glaciers, Permafrost 69.6 1.79
Groundwater 30.1 1.7
Lakes 0.26 0.013
Soil Moisture 0.05 0.001
Atmosphere 0.04 0.001
Wetlands, Swamps 0.03 0.0008
Rivers 0.006 0.0002
Biological Water 0.003 0.0001
Source USGS
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Freshwater
Groundwater Lakes Soils Wetlands Rivers
Atmosphere
Biological
0.775
0.8
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Cycling of Water in the Environment
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Hydrologic Cycle
The hydrologic cycle takes place in the
hydrosphere, this is the region containing all
the water in the atmosphere and on the surface
of the earth. The cycle is the movement of water
through this hydrosphere.
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    Condensation     Infiltration
    Runoff      Evaporation     
Precipitation
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Fate of Precipitation
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Understanding Soil Water The Water Molecule
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Water Molecule
Shared electrons
Bond of shared electrons
O
H
H
O
H
H
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Electrons are negatively charged, protons positive
Oxygen is electron greedy
Oxygen pulls electrons toward itself and away
from hydrogen
O
H
H
P
P
This pulling of electrons toward itself is called
electronegativity
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Abundant electrons (negative charge)
O
H
H
Two protons ( charge)
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Polarity
_
Red lots of e- Blue few e-



Electric Dipole
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Polarity
Slight positive charge
Electric Dipole
Slight negative charge
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Orientation
Opposite charges attract each other
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Hydrogen Bonding in Water
Bonds are ephemeral, continuously breaking and
reforming
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Cohesion
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The cohesion of water molecules is partly
responsible for the overall movement and
retention of water in soils
Next Movement of water Forces and Energies