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