RiversRivers

RiversRivers

Many originate from Many originate from snowmelt in mountainssnowmelt in mountains

Runoff provides rivers with Runoff provides rivers with nutrientsnutrients

Three “stages”, varying in Three “stages”, varying in temperature and velocitytemperature and velocity

• Youthful (erosion zone)Youthful (erosion zone)• Mature (transport zone)Mature (transport zone)• Senile (deposition zone)Senile (deposition zone)

Youthful stage Youthful stage (Upper course)(Upper course)

Senile Stage Senile Stage (Lower course)(Lower course)

THREATS TO RIVERSTHREATS TO RIVERS

Drainage for agricultural useDrainage for agricultural use Drainage for manufacturing useDrainage for manufacturing use RedirectionRedirection DamnsDamns PollutionPollution

WetlandsWetlands

What are they?What are they?

Why are they important?Why are they important?

What are wetlands?What are wetlands?

The U.S. Fish and Wildlife Service defines wetlands as The U.S. Fish and Wildlife Service defines wetlands as the “…lands transitional between terrestrial and aquatic the “…lands transitional between terrestrial and aquatic systems where the water table is usually at or near the systems where the water table is usually at or near the land surface or the land is covered by shallow water.” land surface or the land is covered by shallow water.” (Cowardin et al., 1979)(Cowardin et al., 1979)

Wetlands must have all of the following characteristics:Wetlands must have all of the following characteristics:

Hydric soilHydric soil HydrologyHydrology Hydrophytic vegetationHydrophytic vegetation Standing water for at least part of the yearStanding water for at least part of the year

Types of wetlandsTypes of wetlandsMarshMarsh

Forested wetlandForested wetland

Wet MeadowWet Meadow

Bog and fenBog and fen

Brackish marshesBrackish marshes – variable salinity – variable salinity Tidal salt marshesTidal salt marshes - saltier water - saltier water EvergladesEverglades

largest freshwater marsh in U.S. largest freshwater marsh in U.S.

Historical perspective on wetlandsHistorical perspective on wetlands

The U.S. total of natural wetlands is estimated at 127 The U.S. total of natural wetlands is estimated at 127 million acresmillion acres

By 1950 45 million acres (35%) had already been By 1950 45 million acres (35%) had already been drained drained

Presently only 10-19% of the area are wetlands (see Presently only 10-19% of the area are wetlands (see figures)figures)

Most wetlands were lost to agricultural expansionMost wetlands were lost to agricultural expansion Some were lost to development due to population growthSome were lost to development due to population growth They were considered wastelands and destroyed until They were considered wastelands and destroyed until

recent scientific research and environmental awareness recent scientific research and environmental awareness stressed their importancestressed their importance

Why are they important?Why are they important? Hydrologic valueHydrologic value—refers to the distribution and —refers to the distribution and

movement of water on or below the earth’s surfacemovement of water on or below the earth’s surface

-wetlands are capable of slowing down -wetlands are capable of slowing down and and retaining water (especially important retaining water (especially important during floods or heavy during floods or heavy rain)rain)

-wetlands play an important role in -wetlands play an important role in groundwater recharge groundwater recharge

-plants along bodies of water slow down -plants along bodies of water slow down sediment deposits in streams and lakes sediment deposits in streams and lakes

(process called erosion) thus improving (process called erosion) thus improving water water qualityquality

Wetland importance…Wetland importance… HabitatHabitat valuevalue—wetlands are some of the most —wetlands are some of the most

biologically rich ecosystems in the world comparable to biologically rich ecosystems in the world comparable to tropical rainforests and coral reefstropical rainforests and coral reefs

-wetlands provide habitats for amphibians, -wetlands provide habitats for amphibians, fish, fish, wildlife, birds and plantswildlife, birds and plants

-some of the species can only survive in the -some of the species can only survive in the wetland environmentwetland environment-there are 500 species of plants and animals -there are 500 species of plants and animals threatened with extinction in Illinois; 55% of threatened with extinction in Illinois; 55% of these depend on wetlands or other aquatic these depend on wetlands or other aquatic

habitats for survival (spotted turtle, Illinois habitats for survival (spotted turtle, Illinois chorus chorus frog, four-toed salamander, black-frog, four-toed salamander, black- crowned crowned night heron and many more)night heron and many more)

Wetland importance…Wetland importance…

Direct use Direct use valuevalue

--ecotourism--ecotourism

--fishing--fishing--production of --production of saw timber saw timber

and and pulpwoodpulpwood----

environmental environmental educationeducation

Wetland importance…Wetland importance…

Water qualityWater quality--wetlands remove --wetlands remove

pollutants from surface pollutants from surface runoff and streamsrunoff and streams

--wetland plants --wetland plants reduce algae bloom and reduce algae bloom and fish kills by transforming fish kills by transforming nitrogen and phosphorus nitrogen and phosphorus into available formsinto available forms

Did you know that…?Did you know that…?

Wetlands are often referred to as “the kidneys of the Wetlands are often referred to as “the kidneys of the landscape” because they filter out harmful materialslandscape” because they filter out harmful materials

One acre of wetland can store 1-1.5 million gallons of One acre of wetland can store 1-1.5 million gallons of floodwaterfloodwater

Wetlands comprise only 5% of the contiguous U.S., Wetlands comprise only 5% of the contiguous U.S., although they are home to 31% of all plant speciesalthough they are home to 31% of all plant species

As many as 50% of North American bird species either As many as 50% of North American bird species either nest or feed in wetlandsnest or feed in wetlands

Threats to WetlandsThreats to Wetlands ““Improvement” of wetlands - Improvement” of wetlands -

drained and cleareddrained and cleared 20% of the wetlands (1 Million 20% of the wetlands (1 Million

acres!) around New Orleans have acres!) around New Orleans have been lost over the last 100 yearsbeen lost over the last 100 years

Read more about it at: Read more about it at: http://magma.nationalgeographic.cohttp://magma.nationalgeographic.com/ngm/0410/feature5/?fs=www3.natim/ngm/0410/feature5/?fs=www3.nationalgeographic.comonalgeographic.com

Residential & Commercial Residential & Commercial developmentdevelopment

Federal regulations now in place Federal regulations now in place to prohibit destruction of wetlandsto prohibit destruction of wetlands

New Orleans : Areas Below Sea LevelNew Orleans : Areas Below Sea Level

Erosion of Lake Ponchartrain (meters per yr)

River SystemRiver System

Protection Against HurricanesProtection Against Hurricanes

Floods replenish land and soil and build new Floods replenish land and soil and build new land from sediments and depositsland from sediments and deposits

Mississippi Delta and Barrier Islands act as a Mississippi Delta and Barrier Islands act as a buffers that slow down storm surges buffers that slow down storm surges

Marshes, swamps, bayous and wetlands act as Marshes, swamps, bayous and wetlands act as sponges absorbing energy and water from sponges absorbing energy and water from hurricaneshurricanes

Sedimentation Sedimentation

Freshwater WetlandsFreshwater Wetlands

Healthy MarshHealthy Marsh

MarshMarsh

Atchafalaya BayouAtchafalaya Bayou

Chandeleurs Prior KatrinaChandeleurs Prior Katrina

Barrier IslandBarrier Island

Chandeleur Barrier IslandsChandeleur Barrier Islands

History That Contributed to TragedyHistory That Contributed to Tragedy

1879: Congress authorized ACE to build levees 1879: Congress authorized ACE to build levees to prevent Spring floodingto prevent Spring flooding

Oil Industry and other development drained, Oil Industry and other development drained, dredged, and built channels and canals dredged, and built channels and canals throughout wetlands and marshesthroughout wetlands and marshes

Mississippi River was channeled to empty at Mississippi River was channeled to empty at continental shelfcontinental shelf

Effects of Levees on Mississippi: in MissouriEffects of Levees on Mississippi: in Missouri

ResultsResults

New Orleans sank further below sea level as New Orleans sank further below sea level as earlier sediments and deposits compacted and earlier sediments and deposits compacted and sank (no new sediments deposited)sank (no new sediments deposited)

Mississippi Delta and Barrier Islands began to Mississippi Delta and Barrier Islands began to disappear – erosion and subsidencedisappear – erosion and subsidence

Wetlands and marshes were fragmented, ripped Wetlands and marshes were fragmented, ripped up, and destroyed, leading to recession of up, and destroyed, leading to recession of coastline coastline

Historic DeltasHistoric Deltas

Channeled Mississippi DeltaChanneled Mississippi Delta

Dredging Marshes and WetlandsDredging Marshes and Wetlands

Levees to Prevent FloodingLevees to Prevent Flooding

Canals Protecting NeighborhoodsCanals Protecting Neighborhoods

Delta CommunityDelta Community

Human-MadeHuman-Made ChannelsChannels

Sand MiningSand Mining

Oil and AgricultureOil and Agriculture

Petro Channels Through MarshPetro Channels Through Marsh

Environmental Impact Prior to KatrinaEnvironmental Impact Prior to Katrina

Rate of disappearance of wetlands: Rate of disappearance of wetlands:

1 acre every 24 minutes1 acre every 24 minutes 60 acres per day60 acres per day 25 to 30 square miles per year 25 to 30 square miles per year By 2050 Louisiana would lose another 1000 square By 2050 Louisiana would lose another 1000 square

miles of marshesmiles of marshes

By 2090, some estimates predict that New Orleans By 2090, some estimates predict that New Orleans will have sunk to approximately 10 to 15 feet below will have sunk to approximately 10 to 15 feet below sea level and that the coastline may have receded to sea level and that the coastline may have receded to a point a point northnorth of New Orleans of New Orleans

Erosion on Barrier IslandsErosion on Barrier Islands

Erosion of Delta and Barrier IslandsErosion of Delta and Barrier Islands

Disappearing and Sinking WetlandsDisappearing and Sinking Wetlands

Disappearing MarshDisappearing Marsh

Erosion: Louisiana CoastErosion: Louisiana Coast

Recent HistoryRecent History

1980s: 5 federal agencies & 6 state agencies have 1980s: 5 federal agencies & 6 state agencies have jurisdiction: turf warsjurisdiction: turf wars

LSU scientists model Katrina disasterLSU scientists model Katrina disaster 1990s: $40 million per year for remediation1990s: $40 million per year for remediation 1998: Hurricane Georges; New Orleans escapes1998: Hurricane Georges; New Orleans escapes Result: “Plan 2050” Cost: 14 billion “prohibitive”Result: “Plan 2050” Cost: 14 billion “prohibitive” 2000 – 2005: little money allocated to Plan 2050; 2000 – 2005: little money allocated to Plan 2050;

significant funds diverted to Iraq war; ACE significant funds diverted to Iraq war; ACE remediation/restoration budget slashedremediation/restoration budget slashed

Other Contributing FactorsOther Contributing Factors

Global warming well underway (but debate Global warming well underway (but debate about causes continues)about causes continues)

2000: US refuses to sign Kyoto Accord2000: US refuses to sign Kyoto Accord Wetlands “redefined” at times to allow more Wetlands “redefined” at times to allow more

development (i.e. more habitat destruction )development (i.e. more habitat destruction ) Atlantic Ocean and Gulf of Mexico waters Atlantic Ocean and Gulf of Mexico waters

extremely warmextremely warm Two fold increase in category 4 and 5 hurricanes Two fold increase in category 4 and 5 hurricanes

in last 30 years in last 30 years

Katrina Strikes!Katrina Strikes!

Flooding in New Orleans and Surrounding Flooding in New Orleans and Surrounding CommunitiesCommunities

Further Erosion of Marshes and WetlandsFurther Erosion of Marshes and Wetlands

Destruction of Barrier IslandsDestruction of Barrier Islands

Levee Breach: KatrinaLevee Breach: Katrina

New Orleans LeveesNew Orleans Levees

Katrina FloodKatrina Flood

Further Destruction of MarshlandsFurther Destruction of Marshlands

Chandeleurs: Pre & Post KatrinaChandeleurs: Pre & Post Katrina

Chandeleurs: Pre & Post KatrinaChandeleurs: Pre & Post Katrina

End Result:End Result:

New Orleans, surrounding New Orleans, surrounding parishes, and much of coastal parishes, and much of coastal Louisiana are now even more Louisiana are now even more vulnerable to hurricanes (as vulnerable to hurricanes (as exemplified by Rita).exemplified by Rita).

SourcesSources

Scientific AmericanScientific American: : ““Drowning New Orleans”. October 2001 Drowning New Orleans”. October 2001

National GeographicNational Geographic: : ““Gone with the Water”. October 2004Gone with the Water”. October 2004