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New Orleans : An Environmental Tragedy That Was Waiting to Happen

Louisiana Coastline. New Orleans : Areas Below Sea Level . River System. Protection Against Hurricanes. Floods replenish land and soil and build new land from sediments and depositsMississippi Delta and Barrier Islands act as a buffers that slow down storm surges Marshes, swamps, bayous and wetlands act as sponges absorbing energy and water from hurricanes.

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New Orleans : An Environmental Tragedy That Was Waiting to Happen

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    1. New Orleans : An Environmental Tragedy That Was Waiting to Happen Zuleyma Tang-Martinez Department of Biology University of Missouri-St. Louis

    2. Louisiana Coastline

    3. New Orleans : Areas Below Sea Level

    4. River System

    5. Protection Against Hurricanes Floods replenish land and soil and build new land from sediments and deposits Mississippi Delta and Barrier Islands act as a buffers that slow down storm surges Marshes, swamps, bayous and wetlands act as sponges absorbing energy and water from hurricanes

    6. Sedimentation

    7. Freshwater Wetlands

    8. Healthy Marsh

    9. Marsh

    10. Atchafalaya Bayou

    11. Chandeleurs Prior Katrina

    12. Barrier Island

    13. Chandeleur Barrier Islands

    14. History That Contributed to Tragedy 1879: Congress authorized ACE to build levees to prevent Spring flooding Oil Industry and other development drained, dredged, and built channels and canals throughout wetlands and marshes Mississippi River was channeled to empty at continental shelf

    15. Effects of Levees on Mississippi: in Missouri

    16. Results New Orleans sank further below sea level as earlier sediments and deposits compacted and sank (no new sediments deposited) Mississippi Delta and Barrier Islands began to disappear – erosion and subsidence Wetlands and marshes were fragmented, ripped up, and destroyed, leading to recession of coastline

    17. Historic Deltas

    18. Channeled Mississippi Delta

    19. Dredging Marshes and Wetlands

    20. Levees to Prevent Flooding

    21. Canals Protecting Neighborhoods

    22. Delta Community

    23. Human-Made Channels

    24. Sand Mining

    25. Oil and Agriculture

    26. Petro Channels Through Marsh

    27. Environmental Impact Prior to Katrina Rate of disappearance of wetlands: 1 acre every 24 minutes 60 acres per day 25 to 30 square miles per year By 2050 Louisiana would lose another 1000 square miles of marshes By 2090, some estimates predict that New Orleans will have sunk to approximately 10 to 15 feet below sea level and that the coastline may have receded to a point north of New Orleans

    28. Erosion on Barrier Islands

    29. Erosion of Delta and Barrier Islands

    30. Disappearing and Sinking Wetlands

    31. Disappearing Marsh

    32. Erosion: Louisiana Coast

    33. Recent History 1980s: 5 federal agencies & 6 state agencies have jurisdiction: turf wars LSU scientists model Katrina disaster 1990s: $40 million per year for remediation 1998: Hurricane Georges; New Orleans escapes Result: “Plan 2050” Cost: 14 billion “prohibitive” 2000 – 2005: little money allocated to Plan 2050; significant funds diverted to Iraq war; ACE remediation/restoration budget slashed

    34. Other Contributing Factors Global warming well underway (but debate about causes continues) 2000: US refuses to sign Kyoto Accord Wetlands “redefined” at times to allow more development (i.e. more habitat destruction ) Atlantic Ocean and Gulf of Mexico waters extremely warm Two fold increase in category 4 and 5 hurricanes in last 30 years

    35. Katrina Strikes! Flooding in New Orleans and Surrounding Communities Further Erosion of Marshes and Wetlands Destruction of Barrier Islands

    36. Levee Breach: Katrina

    37. New Orleans Levees

    38. Katrina Flood

    39. Further Destruction of Marshlands

    40. Chandeleurs: Pre & Post Katrina

    41. Chandeleurs: Pre & Post Katrina

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

    43. Sources Scientific American: “Drowning New Orleans”. October 2001 National Geographic: “Gone with the Water”. October 2004

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