Environmental problems worsened Hurricane Katrina’s impact
Rhett A. Butler, mongabay.com
August 31, 2005
Updated: September 2, 2005
The loss of coastal marshlands that buffer New Orleans from flooding and storm surges may have worsened the impact of Hurricane Katrina.
In the past, the region’s wetlands have served as a natural buffer that slows hurricanes down as they come in from the Gulf of Mexico and helps protect New Orleans from storms. But all this has changed.
Experts say the construction of levees along the Mississippi river delta has hastened the decline of wetland vegetation along the coast by preventing these ecosystems from recieving the floodwater and mud that they need to survive. Joe Suhayda, a retired coastal engineer at Louisiana State University who has spent 30 years studying the Gulf coast, says in an interview with American Public Radio, “So the hurricane can move closer to the city before it starts to decrease. So in effect, the city is moving closer to the Gulf as each year goes by.”
America’s Wetland, a Baton Rouge organization, estimates that More than 1,900 square miles of the Louisiana have disappeared since the 1930s due to development and the construction of levees and canals. This, coupled with the loss of barrier islands and stands of natural vegetation has made the New Orleans area more susceptible to storm surges. Sharon Begley, a science columnist for The Wall Street Journal, notes that studies have shown that for every square mile of wetlands lost, storm surges rise by one foot.
Global warming may only make the situation worse by rising sea levels and warmer seas that will fuel ever stronger storms.
Composite NASA images assembled by The Wall Street Journal
Late last month an atmospheric scientist at Massachusetts Institute of Technology released a study in Nature that found hurricanes have grown significantly more powerful and destructive over the past three decades. Kerry Emanuel, the author of the study, warns that since hurricanes depend on warm water to form and build, global climate change might increase the effect of hurricanes still further in coming years.
The storm hit Breton Sound with the fury of a nuclear warhead, pushing a deadly storm surge into Lake Pontchartrain. The water crept to the top of the massive berm that holds back the lake and then spilled over. Nearly 80 percent of New Orleans lies below sea level—more than eight feet below in places—so the water poured in. A liquid brown wall washed over the brick ranch homes of Gentilly, over the clapboard houses of the Ninth Ward, over the white-columned porches of the Garden District, until it raced through the bars and strip joints on Bourbon Street like the pale rider of the Apocalypse. As it reached 25 feet (eight meters) over parts of the city, people climbed onto roofs to escape it.
Thousands drowned in the murky brew that was soon contaminated by sewage and industrial waste. Thousands more who survived the flood later perished from dehydration and disease as they waited to be rescued. It took two months to pump the city dry, and by then the Big Easy was buried under a blanket of putrid sediment, a million people were homeless, and 50,000 were dead. It was the worst natural disaster in the history of the United States.
When did this calamity happen? It hasn’t—yet. But the doomsday scenario is not far-fetched.
So they launched what’s become one of the biggest construction projects in history. To protect their investments. As of today, the us arm has built 2000 miles of levees to stop the Mississippi from flooding. And until recently, scientists thought that these walls of soil and concrete and steel had made New Orleans safe. They never dreamed that the levees would come back to haunt them.
When emergency management officials think about the worst natural disasters that might befall America, San Francisco is always on the list. They say there’s a 70 percent chance that a major earthquake will hit that city in the next 30 years and potentially cause thousands of deaths. But they say there’s another disaster that could be far worse—and many people don’t know about it. The chances that this tragedy will happen are much lower, but the death toll would be staggering. Government officials are trying to figure out if there’s any way to prevent it…
…Some scientists believe that if a huge storm hits New Orleans, the city would have to be abandoned. Bulldoze the rubble, rebuild someplace else. But Suhayda thinks they could save a piece of it.
This article used information from NPR, PBS, National Geographic, The Wall Street Journal, and American RadioWorks.