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oceans. lakes and rivers. atmospheric water. continental and sea ice. The water planet. Water. -. O. H. H. +. Water: we waste it, we pollute it, we take it for granted…. Virtually the most valuable commodity we have (except maybe O 2 ). You're about 70% Water!. - PowerPoint PPT Presentation
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The water planet
atmospheric water
continental and sea ice
oceanslakes and rivers
O
Water
HH+
-
Water: we waste it, we pollute it, we take it for granted….
Virtually the most valuable commodity we have (except maybe O2)
Tree = 60% water jelly fish = 90% water
Where has your water come from???
All of the Earth's waters are connected and cleaned by the HYDROLOGIC CYCLE
Water moves through the hydrologic cycle at various speeds.For example:
40,000 years to recycle oceanic water
2 weeks to recycle river water9 to 10 days to recycle atmospheric
water
Energy for the hydrological cycle
• is from the sun (solar power)
• The atmosphere is a heat trap– H2O is a greenhouse gas
• Hydrologic cycle = main global energy redistribution system--thru both the oceans and the atmosphere
Ocean currentsThe Atlantic Gulf stream carries energy at a vast rate from the gulf of Mexico to the Arctic Ocean: all the coal mined in the world in one year could supply energy at this rate for only 12 hours!
(Franks 1984)
The hydrological cycle
Evaporation
• Injects water vapour into atmosphere• Uses 50% of energy at earths surface
(cools the earth’s surface)
The Atmosphere
• only 0.001% of all water • links major water stores
– evaporation– condensation– precipitation
• cold air hold less water than hot air• as hot air rises and cools,
precipitation can form
Effect of vegetation on rainfall
P — precipitation
Effect of vegetation on rainfall
EI—evaporation of intercepted rain
ET—transpiration
Interception loss may be 20 – 40% of total rainfall for forests
Hillslope runoff processes
infiltrationoverland flow
water table
shallow subsurface flowdeep drainage
baseflow
The majority of accessible fresh water is groundwater, water beneath the Earth's surface.
About 10% of precipitation will infiltrate the soil and rock to become groundwater, forming a water table.
Water saturated permeable rock is an aquifer.
Aquifers
Rivers
The Water Balance
May be applied to whole river basins or catchments
SQEP Δ=++
total evapotranspiration
catchment rainfall
river + groundwater discharge
change in soil, groundwater storage
The water balanceQuantifying the hydrological cycle
saturated zone
unsaturated soil
Rainfall
P
Evaporation
EChange in storage
ΔSDischarg
eQ
= +15 mm
= -4 mm
= -6 mm
SQEP Δ=++
15 – 4 – 6 =+5 mm
= +5 mm
0.03% of world’s water is readily available
Not evenly distributed
human water use has increased 4 times in the last 50 yrs!
increasing population and
increasing use per person
~70% used for Agriculture
waste water production=1870 km3 in1980
2300 km3 in 2000
- The BIG water use
1950 -80 world irrigation area tripled
1990: 7% less irrigated area per person than 1980
inc. competition between rural and urban water use
21% of USA crop irrigated by draw-down of W.T
26% of world irrigated area suffers waterlogging and salinization
NOT SUSTAINABLE
The Ogallala Aquifer
Water use
WATER SAVINGS GUIDEWATER SAVINGS GUIDE
Activity:Conservative use- saves water
Normal use -- wastes water
ShowerWetdown/rinse off: 4 gallons
Regular shower: 25 gallons
Brushing teeth Wet brush, brief rinse: 1/2 gal.
Tap running: 10 gallons
Toilets Minimize flushing, low-flush toilets
Old toilet, frequent flushing?!?!
Leaks Report ASAP A small drip: 25 gallons per day
Energy Turn off power Wasting energy wastes water