The furious storm: one wild hurricane could drown a major American City. Can scientist prevent the disaster in time?

Science World, Oct 18, 2002 by Larry O'Hanlon

But even with a walled-off safe haven, it could take months to pump the rest of New Orleans dry. What's more, water damage and toxic chemical leaks from flooded industrial facilities in the area would probably make much of New Orleans impossible to live in, says Willoughby: "We may need a new New Orleans."

A HURRICANE'S DIRECT HIT could plunge New Orleans' fabled French Quarter (far left) underwater. Fast-eroding coastal marshes (center) make the city more vulnerable to hurricane damage. Experts worry the city could suffer similar devastation to the Galveston storm of 1900 (left), which killed around 8,000. (big picture) Florida Keys residents flee 1998's Hurricane Georges.

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NEW ORLEANS city under siege?

HOW A CITY CAN DROWN

This elevation map shows a large part of New Orleans lies below sea level (in red). If hurricane winds blew from north to south, surging water from Lake Pontchartrain could flood--and become trapped--in these below-sea-level areas.

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COASTAL DEFENSES

Going, going, gone?

Marshes south and east of New Orleans once shielded the city from storms. But they're eroding quickly.

THEN: NATURAL FLOW

The Mississippi's periodic floods once spread sediment and mud--building up protective marshes.

NOW: VANISHING MARSHES

Levees (earthen walls) and canals reroute the river. Sediment washes away into the sea.

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ESCAPING THE STORM

City planners worry that evacuating New Orleans' residents during a hurricane could be deadly: (1) Interstate 10 can easily flood from Lake Pontchartrain. (2) When winds exceed 50 mph, the 24-mile Lake Pontchartrain Causeway is shut. (3) Traffic gridlock would clog Interstates 10 and 59.

If you had to come up with an evacuation plan for this endangered city, what would it be?

IT'S YOUR CHOICE

Choose the correct answer(s) to these questions:

1 Which factor(s) would make New Orleans
less vulnerable to hurricane damage?

A eroding marshlands    C inner-city wall
B rising sea levels     D pumping groundwater

2 Which of the following have rerouted
the Mississippi River?

A levees                         C canals
B Lake Pontchartrain Causeway    D Interstate ID

3 In the map above, which section of
New Orleans lies six feet below sea level?

A Algiers        C Downtown
B Matairie       D French Duarter

4 How many feet above sea level would
Lake Pontchartrain's average crest be
in a moderate hurricane?

A 6      C 10
B 12     D 24

ANSWERS IN TEACHER'S EDITION

HOW HURRICANES FORM

A hurricane is a tropical cyclone with fierce winds of at least 74 miles per hour. It can stretch out to 600 miles in diameter. Here's how a typical hurricane forms.

1 Warm water meets moving air

An Atlantic Ocean hurricane is born when sun-heated seawater evaporates into warm, moist air, or water vapor. The humid air collides with westward-moving airwaves from Africa.

2 A tropical storm forms

As the humid air rises, it cools and condenses to form thunderclouds.

3 The storm become a hurricane

Fierce winds and Earth's rotating axis swirl the thunderclouds like a pinwheel. When winds reach 74 miles per hour, the storm officially becomes a hurricane.