ABSTRACT
Modern levee construction and municipal drainage effectively ended the occasional flooding from river, lake, or sky that frustrated New Orleanians in historical times. These interventions also inadvertently eliminated incoming freshwater and sediment, removed the water component from the soil body, and allowed organic matter to decompose. An extensive network of oil and gas canals instigated the same cycle throughout the Louisiana coastal region: intrusion, wave action, swamp die-off, erosion. Coastal wetlands protect New Orleans because they buffer hurricane-induced gulf surges and help prevent them from reaching the bowl-shaped city. Any form of friction and impedance that can be inserted between open water and populated areas, barrier islands, marshes, swamps, vegetation, ridges serves to reverse a certain level of incoming surge. New Orleans's extraordinary geophysical problems overshadow its numerous routine environmental hazards. For example, high levels of soil lead, associated with lead-based paint, occur where automobiles and wooden housing stock are concentrated.
