Transcript Water Unit Hydrologic Cycle and Human Water Use.

Environmental Sciences: Water Unit
Hydrologic Cycle and Human Water Use.
Contents of this power point
Basic Water Knowledge and Review
– Slides 2 – 20
How do Humans affect Water Distribution?
– Slides 21 – 29
Chapter 11 Sustaining Aquatic Biomes
– Slides 30 – 64
– End here for Quiz
Special Properties of Water:
• Exists in three phases:solid, liquid, gas.
• Polar molecule due to unequal sharing of
electrons in the H2O molecule.
• High Surface tension & great solvent. Makes it
adhesive & cohesive.
• High heat capacity due to hydrogen bonding.
The Water Cycle is Nature’s Way to
by Evaporation/
• Purify
Human Water
have managed
to pollute or Filtration.
compromise the function of the loop.
• We are running out of water in terms of
quantity and quality.
• Water conservation and stewardship are
imperative actions.
Earth’s Water
Fresh Water Properties:
1. Makes up less than 3% of all water
on Earth. This includes the Polar Ice
caps and glaciers. Less than 1% is
ready to treat and use.
2. Has a salt content of less than 0.01%
3. Is constantly being recycled
naturally.
4. Makes up > 70% of the human body.
5. Is necessary for all life on Earth.
Water Cycle Processes
• Evaporation: water molecules move from
liquid to gaseous state; e.g. steam
• Condensation: water molecules move from
gaseous to liquid or frozen state; e.g. water
droplets on cold beverage container
• Purification: occurs as a result of evaporation
and condensation; impurities are left behind
Condensation
Precipitation
• Adiabatic cooling:
warm air rises,
expands and cools
• 100% relative
humidity + cooling =
clouds
• Increasing
condensation = water
droplets
The Water Cycle
Water Cycle
Filters
Evaporative-transpiration
Loop
F
D
G
Surface Runoff
Loop
E
B
Ground Water
Loop
A
C
Human Impacts on the Water Cycle
• Changing the earth’s surface
• Pollution
• Withdrawal for use
Review
Global Precipitation and Weather
• Global precipitation distribution depends on
patterns of rising and falling air currents
• Two main factors:
– global convection currents
– rain shadow effect
Review: What Controls
Weather?
•
Atmospheric
Pressure and Solar
Energy!
1. Low Pressure=
Storms / rain
2. High Pressure =
Fair skies
Review: Major World Climates
Review: World Precipitation Levels
Review: What affects Climate?
Global Wind
Mechanisms that
give rise to
weather patterns.
Review: Rain Shadow Effect
How do humans change the Earth’s
surface?
1.
2.
Changing Earth’s Surface Through
Urbanization
• Decreased infiltration
• Increased runoff
How do humans pollute the water?
1.
2.
3.
4.
Water Pollution
How do humans use water?
1. Agricultural uses
2. Domestic Uses
3. Industrial uses
Water Use
Agriculture
Water Use:
Consequences of Overdrawing Water
Supplies
• Surface waters:
– shortages
– ecological effects
Water Use
Chapter 11: Sustaining Aquatic Environments
• Be sure to read Chapter 11, noting the Major
concepts in each sections.
• This power point does not follow the order in
the text book, but highlights all the major
facts and concepts you need to know.
Why are Wetlands Vanishing?
• Urbanization: filling-in, covered over
• Draining: disease control(mosquito-born e.g. malaria)
• Extraction of minerals, oil & gas
Ecological Services of Wetlands:
Hydrological Cycle
•
•
•
•
Purify waters: filtering toxins & waste
Control floods: absorb storm water& overflow
Protect shorelines: against erosion
Recharge groundwater & aquifers
Ecological Services of Wetlands: Chemical
Cycles
• Nitrogen cycle
• Sulfur cycle
• Carbon cycle
Ecological Services of Wetlands: Increase
Biodiversity
• Terrestrial ecosystems:
• Aquatic ecosystems
Wetland Services - Economic
•
•
•
•
•
•
•
Pelt and skin harvesting (alligator)
Waterfowl hunting
Sport and commercial fishing
Timber harvesting (hardwood and cypress swamps)
Energy source
Food source
Recreation
Wetland Services - Intrinsic
• Bird watching and
wildlife photography
• Recreation (hiking,
boating)
• Biological laboratory
for students of all ages
Consequences of Overdrawing
• Groundwater:
– Falling water tables
– Diminishing surface waters
– Land subsidence
– Saltwater intrusion
(wetlands)
Aquifer Exploitation
The Ogallala Aquifer
is the world’s largest
and is used
extensively to make
this area of the USA
productive.
Irrigation on a Large Scale
Irrigation by Drip Method Saves Water
Sinkholes: YIKES!
Saltwater Anyone?
Using Less Water
• Irrigation
 Surge flow
 Drip irrigation $$
• Municipal uses
 Incentives
 regulations limiting water use
 Gray water
Must know Figures in CH 11
• Fig. 11-12 Managing Fisheries
• Fig. 11-16 Ecological Services of Rivers
• Fig 8-14 Natural Capital of Fresh Water
Systems
How do we Protect Aquatic Habitats?
• Regulations, laws & enforcement
• Economic incentives
• Preservation & restoration
How do we protect & preserve
Wetlands?
• Zoning laws – control development
• Federal Permits to dredge
• “Mitigation Banking”
Mitigation Banking
(a last resort!?)
• Requires that new wetlands be constructed before
existing is destroyed
• Nat’l Acad of Science -> can’t replace & expect it to
do as well as the natural
• Don’t actually meet the goals
• Not adequately monitored
Restoration of a wetland: Florida Everglades:
CERP (Comprehensive Everglades Restor. Plan)
Why needed? Drying up & polluted
Cause: population growth therefore ^ need
• Diversion of input (^salt; ^ temp)
• Increased Nutrients (run-off: ^algal blooms,
dec. O2 & ^CO2
CERP’s Idea Good or Bad?
•
•
•
•
•
Restore flow
Remove canals & levees that block flow
Buy land (sugar cane farms) & flood it
Build 18 Reservoirs for storage
Build new canals
What is wrong with this picture?
Problems with CERP
• Resistance from farmers – political pressure &
delays
• Big budget grows with delays
• Will it really work?
Managing Rivers & streams
Law: National Wild & Scenic Rivers Act
• Established Protection of rivers
• “wild” = inaccessible
• “scenic” = no dams or obstructions
Managing Rivers & streams
Dams: Good or Bad?
Economic Services
• reservoir for water storage (irrigation,
domestic & industrial use)
• Recreation
• Flood control
• Electricity generation
Dams: Good or Bad?
• Decreases habitat up- & down stream
• Disrupts life cycles and spawning
• Decreases nutrients downstream
Managing Rivers & Streams
Invasive Species
– Sea Lamprey
– Zebra mussel
– Asian Carp
• What are some characteristics of invasive
species?
Managing Rivers & Streams
Invasive Species (review points)
• High reproductive rate
• No predators
• Opportunists
• Wide range of Tolerance
• Out compete indigenous species
Marine Species & Habitat Protection
Why difficult?
• Monitoring
• Damage unseen by public
• Viewpoint that it’s inexhaustible
Marine Species & Habitat Protection
Laws & treaties:
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CITES (Conv. Internat’l Trade Endangered Spec)
ESA 1973
U.S. Whale Concervat’n & Protection Act 1976
U.S. Marine Mammal Protect’n Act 1972
Marine Species & Habitat Protection
Economic Incentives:
• Economic & Political pressures
• Ecotourism industry: (e.g. Dominican Republic town &
whale watching; Florida towns & leatherback turtles)
• Govt subsidies to help $$ needs of fishermen &
decrease illegal fishing
• Education of fishermen limits allow population to
increase
Marine Species & Habitat Protection
Economic Incentives:
• Educate public
– www.seafoodwatch.org
• Make ownership of fisheries private
Marine Species & Habitat Protection
Protection
• Sanctuaries
• Global Network of Marine Reserves (E.O. Wilson)
• Smaller, sustainable fisheries near coastal zones & near upwellings
• Global Community involvement: WWF, IUCN, Nature Conservancy, Royal
Society for Protection of Birds
Marine Species & Habitat Protection
Protection
• Max sustainable yield
– Traditional—doesn’t work
– Difficulty est. populations & growth rates
• Optimum sustainable yield
• Total allowable catch
Marine Species & Habitat Protection
Global Network of Marine Reserves (E.O. Wilson)
• Use “ecosystem approach
• Off-limits to human activities
Marine Species & Habitat Protection
• Reduce overfishing
• Decrease pollution
– Nutrients
– Toxic chemicals, heavy metals
• Decrease release of CO2 into atmosph.
– Causes acidification of water (a problem for corals
(CaCO3 decrease)
Managing & Sustaining Fisheries
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•
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Regulate seasons
Establish and enforce quotas
Build reservoirs & stock them
Protect habitats from