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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