Post on 16-Dec-2015
transcript
Hurricane KatrinaHurricane Katrina Storm Surge Storm Surge
Induced FloodingInduced FloodingLow-Lying New Orleans:Low-Lying New Orleans:
How to Prevent Future DamagesHow to Prevent Future Damages
and
IntroductionIntroduction
What is storm surgeWhat is storm surge What happened What happened
during Hurricane during Hurricane KatrinaKatrina
Why New Orleans is Why New Orleans is vulnerablevulnerable
The future of New The future of New OrleansOrleans
http://www.pbs.org/wgbh/nova/sciencenow/dispatches/images/050901-katrina2-l.jpg
What is a Storm Surge?What is a Storm Surge?
““Meteorological Meteorological Residual”Residual”
Most dangerous Most dangerous phenomenon phenomenon associated with associated with hurricaneshurricanes
Accounts for 70-90% of Accounts for 70-90% of death & damagedeath & damage
What is Storm Surge?What is Storm Surge?
Large change in sea levelLarge change in sea level Generated by extreme weather conditionsGenerated by extreme weather conditions ““Mound” of water driven toward shore by Mound” of water driven toward shore by
stormstorm Waves on top of surge devastate areaWaves on top of surge devastate area
Water weighs 1000 kg/mWater weighs 1000 kg/m33 – Immense – Immense potentially destructive powerpotentially destructive power
BackgroundBackground
General Factors Contribute to Storm SurgeGeneral Factors Contribute to Storm Surge Storm WindsStorm Winds Wave Run-UpWave Run-Up Low Pressure inside the stormLow Pressure inside the storm Astronomical TidesAstronomical Tides
Local FactorsLocal Factors Slope of Continental ShelfSlope of Continental Shelf Shape of CoastlineShape of Coastline Elevation relative to sea levelElevation relative to sea level
Dangers of SurgeDangers of Surge
Devastating to low-lying coastal regionsDevastating to low-lying coastal regions Bay of Bengal - IndiaBay of Bengal - India Galveston – TexasGalveston – Texas
Inland SurgeInland Surge Lake Okeechobee, FloridaLake Okeechobee, Florida
• 1928-3m surge; Hurricane San Filippe1928-3m surge; Hurricane San Filippe• 1,836 people killed, massive flooding1,836 people killed, massive flooding
Lake Pontechrain, LouisianaLake Pontechrain, Louisiana• 2005 ~8m; Hurricane Katrina2005 ~8m; Hurricane Katrina• Death toll-unknown and still risingDeath toll-unknown and still rising
http://www.spaceimaging.com/gallery/hurricanes2005/katrina/NewOrleans/NewOrleans1.jpg
BEFORE AFTER
Before and After Before and After
http://chattablogs.com/quintus/new_orleans1.jpg
Satellite ImagesSatellite Images
After – August 30thAfter – August 30th
Before – August 27thBefore – August 27th
http://www.nasa.gov/images/content/126535main_neworleans_flood_0831.jpg
What Happened During Katrina?What Happened During Katrina?
Storm SurgeStorm Surge ~8 meters (25-28 feet)~8 meters (25-28 feet) Water is STRONG!Water is STRONG! Pumping Stations Pumping Stations
floodedflooded• Lack of drainage in cityLack of drainage in city• Left helplessLeft helpless
What Happened During Katrina?What Happened During Katrina?
Channels/CanalsChannels/Canals Lack of sea gates allowed water to flow deep into the Lack of sea gates allowed water to flow deep into the
citycity Intense pressure from water and windsIntense pressure from water and winds Protective walls brokeProtective walls broke FunnelingFunneling
• MRGO & Intracoastal WaterwayMRGO & Intracoastal Waterway
New Orleans Flood MapNew Orleans Flood Map http://http://mapper.cctechnol.com/floodmap.phpmapper.cctechnol.com/floodmap.php
Why is New Orleans VulnerableWhy is New Orleans VulnerableBelow Sea LevelBelow Sea Level
City averages 6 feet City averages 6 feet below sea levelbelow sea level
Drainage of former Drainage of former swamp areas led to swamp areas led to subsidencesubsidence
Located between Located between levees of Lake levees of Lake Pontchartrain and Pontchartrain and Mississippi RiverMississippi River
Creates “bowl” effectCreates “bowl” effecthttp://en.wikipedia.org/wiki/Image:New_Orleans_Levee_System.gif
New Orleans ElevationNew Orleans Elevation
Why is New Orleans VulnerableWhy is New Orleans VulnerableDisappearing Wetlands and Barrier IslandsDisappearing Wetlands and Barrier Islands
Wetlands and Barrier Islands Wetlands and Barrier Islands are best natural defense against are best natural defense against storm surgesstorm surges
For every mile of continuous For every mile of continuous wetland the height of a storm wetland the height of a storm surge can be reduced 3 to 8 surge can be reduced 3 to 8 inchesinches
Wetlands and Barrier Islands Wetlands and Barrier Islands are naturally replenished with are naturally replenished with sediment from the flooding sediment from the flooding MississippiMississippi
Before and after Hurricane Katrina
http://news.nationalgeographic.com/news/2005/09/images/050919_katrina_delta.jpg
Why is New Orleans VulnerableWhy is New Orleans VulnerableDisappearing Wetlands and Barrier IslandsDisappearing Wetlands and Barrier Islands
Upriver Dams have reduced Upriver Dams have reduced sediment in the river by up sediment in the river by up to 67%to 67%
Levees built around New Levees built around New Orleans channel the rivers Orleans channel the rivers flow far out into Gulf of flow far out into Gulf of MexicoMexico
Wetlands and barrier Wetlands and barrier islands being denied natural islands being denied natural replenishmentreplenishment
http://news.minnesota.publicradio.org/features/2003/08/14_hetlandc_morupdate/images/gavinspointdam_large.jpg
Why is New Orleans VulnerableWhy is New Orleans VulnerableDisappearing Wetlands and Barrier IslandsDisappearing Wetlands and Barrier Islands
Over the last 50 years Over the last 50 years wetland loss has been about wetland loss has been about 60 square kilometers per 60 square kilometers per yearyear
Canal construction has Canal construction has allowed saltwater intrusion allowed saltwater intrusion to freshwater marshes to freshwater marshes
Additional salinity kills native Additional salinity kills native plants, which causes even plants, which causes even more erosionmore erosion
http://www.whitehouse.gov/omb/budget/fy2005/images/corps-6.jpg
The Future of New OrleansThe Future of New OrleansRebuilding Current StructuresRebuilding Current Structures
Restore New Orleans Restore New Orleans to Pre-Katrina before to Pre-Katrina before June 1June 1stst
Official start of Official start of hurricane seasonhurricane season
Many building permits Many building permits already given outalready given out
Work continues, Wednesday, Nov. 30, 2005, at the 17th Street Canal floodwall that was breached after Hurricane Katrina in New Orleans. Government
engineers performing sonar tests at the 17th Street Canal found exactly what independent investigators said they would, that steel reinforcements barely
went more than half as deep as they were supposed to, a U.S. Army Corps of Engineers official said Wednesday. (AP Photo/Cheryl Gerber)
http://ap.lancasteronline.com/5/new_orleans_levees
The Future of New OrleansThe Future of New OrleansSea GatesSea Gates
Giant air-filled wallsGiant air-filled walls Across Lake Across Lake
Pontchartrain’s two Pontchartrain’s two inletsinlets
Considered since Considered since 1960’s1960’s
Used in Holland & Used in Holland & BritainBritain
Cost ~ $500 million-1 Cost ~ $500 million-1 billionbillion
http://www.alumni.northwestern.edu/travel/holland-belgium-photos.html?action=viewPhoto&photoID=1115312046
The Delta Project - Holland
The Future of New OrleansThe Future of New OrleansClosing/Covering CanalsClosing/Covering Canals
Only keep heavily used canals openOnly keep heavily used canals open Cover others (turn into culverts $$$)Cover others (turn into culverts $$$) Turn into parks/trailsTurn into parks/trails
Today, only a slim
line of broken
marsh lies between
the MRGO and Lake Borgne (top of frame).
http://www.louisianasportsman.com/stories/2003/paradise-lost/future-of-mrgo.htm
MRGO
The Future of New OrleansThe Future of New OrleansWetland RehabilitationWetland Rehabilitation
Dredging Dredging of canalsof canals
Saltwater Saltwater intrusionintrusion
Hand Hand planting planting is costlyis costly
http://www.pbs.org/journeytoplanetearth/images/1la2.jpg
The Future of New OrleansThe Future of New OrleansBarrier IslandsBarrier Islands
First line of protectionFirst line of protection Shrinking rapidlyShrinking rapidly Coast 2050Coast 2050 http://www.earthsky.com/humanworld/shows.php?date=20051230
Coast 2050 Coast 2050
http://www.coast2050.gov/barrier_island.htm
The Future of New OrleansThe Future of New OrleansOther IdeasOther Ideas
Move pumping Move pumping stationsstations
Drainage SystemsDrainage Systems Contain Contain
NeighborhoodsNeighborhoods Connect barrier Connect barrier
IslandsIslands Netherlands: Delta Netherlands: Delta
WorksWorks Lowlands into parksLowlands into parks
http://www.globalsecurity.org/military/facility/new-orleans-flooding-pics.htm
ConclusionConclusion
New Orleans future is New Orleans future is unclearunclear
Will take multiple Will take multiple solutions to protect solutions to protect the sinking citythe sinking city
High cost and will High cost and will take years to infiltratetake years to infiltrate
http://www.globalsecurity.org/military/facility/new-orleans-flooding-pics.htm
http://rst.gsfc.nasa.gov/Sect14/Sect14_10a.html
THANKS!!!THANKS!!!
http://www.all4all.org/images/2005/09/2065.jpg
Chris BelowChris BelowChris DierichChris Dierich
Keith EricksonKeith EricksonRachel KjosRachel Kjos