Environmental Sciences: Water Unit Hydrologic Cycle and Human Water Use.

Contents of this power pointBasic 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 Purify Water by Evaporation/ Filtration.• Human have managed to pollute or

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

A

B

C

D

E

Water Cycle Filters

Ground WaterLoop

Surface RunoffLoop

Evaporative-transpirationLoop

F

G

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 ControlsWeather?

• Atmospheric Pressure and Solar

Energy!1. Low Pressure=

Storms / rain2. 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 uses2. Domestic Uses3. Industrial uses

Water Use

AgricultureWater 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 (wetlands)– Land subsidence– Saltwater intrusion

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 useGray 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 & pollutedCause: 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 & streamsDams: 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: • 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

• Regulate seasons • Establish and enforce quotas• Build reservoirs & stock them• Protect habitats from