Hurricanes and nor’easters: The Big Winds

Hurricane katrina: A Case Study of the Costliest Disaster in U.S. History photo.

About Natural Hazards and Disasters: 2006 Updated Edition: In their book, Donald and David Hyndman focus on Earth and atmospheric hazards that appear rapidly, often without significant warning. With each topic they emphasize the interrelationships between hazards, such as the fact that building dams on rivers often leads to greater coastal erosion, and wildfires generally make slopes more susceptible to floods, landslides, and mudflows. By learning about the dynamic Earth processes that affect our lives, the reader should be able to make educated choices about where to live, and where to build houses, business offices or engineering projects. People do not often make poor choices willfully but through their lack of awareness of natural processes.

Hyndman 0495153214 Page 1.indd 1 3/29/06 12:40:31 PM

Hurricanes and Nor’easters: The Big Winds : A Case Study of the Costliest Disaster in U. S. History

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Hurricanes, Typhoons, HURRICANES and Cyclones

Hurricanes in the North Atlantic and eastern Pacific; ty- AND phoons in the western Pacific, Japan, and Southeast Asia; and cyclones in the Indian Ocean are all major sub- NOR’EASTERS tropical cyclones. They have wind speeds of more than 120 kilometers per hour and can exceed 260 kilometers per The Big Winds hour. They have killed more people annually than any other natural hazard. The worst disasters have occurred in heavily populated poor countries in Southeast Asia, in events result- ing in hundreds of thousands of deaths in a single event. The word hurricane is derived from a Caribbean native Indian language and means “big wind.” A develops, by definition, as a large, warm-core, low-pressure system over tropical or subtropical waters with a tempera- ture of at least 25°C; cyclones circulate counterclockwise in the northern hemisphere, clockwise in the southern hemi- sphere. This definition excludes severe thunderstorms at frontal systems that may have hurricane-force winds.

Hyndman 0495153214 Chapter 14.in1 1 3/24/06 11:57:43 AM Hurricanes up close Hurricane Hugo

Rebuilding in the aftermath of 1989’s Hurricane Hugo was fraught with problems. The same is true after most other ma- jor hurricanes. Poorly trained and untrained workers, hasty and shoddy work, unsuitable materials, and unscrupulous contractors were everywhere. Inspection was inadequate or absent. Many beaches were heavily eroded and dunes flattened, and damage to homes was extensive 4 ( Figures 14-1 and 14-2). The storm caused 105 deaths, eleven of them in the Charleston area and twenty-nine in all of ; property damage was $12.3 billion (in 2002 dollars). Al- though the largest insured payments were for flooding caused by , the dramatic rise in sea level from low atmo- spheric pressure and push of the sea ahead of the prolonged winds, flooding did less than 10 percent of the total dollar U.S. Army Corps of Engineers. damage. Wind damage was much greater. Depending on 4 Figure 14-2. This house was not well attached to its founda- coastal location, the storm probably had an 80- to 200-year tion. Hurricane Hugo’s surge carried it inland, where it was depos- recurrence interval. ited on a roadway. Hurricane Hugo initially lashed the Leeward Islands and with sustained winds of 225 kilometers per hour, leaving more than 30,000 homeless, and causing damages of $9.9 billion. Although satellite and aircraft tracking permitted South Carolina lacked restrictions over the use of coastal the populace to be kept informed of the hurricane’s track and sites and the quality of construction. That was left to local intensity in 1989, most communities did not take advantage communities, some of which imposed controls while others of the information. provided few or none. Most adopted a building code only when they wanted to participate in the National Flood Insur-

4 Figure 14-1. Hurricane Hugo caused rampant destruction of beachfront homes on Sullivan’s Island, South Carolina. It destroyed homes behind the two in the fore- ground, which were also damaged. It even wrecked nearly new homes on 3-meter-high

S. J. Williams photo, USGS. pilings.



Hyndman 0495153214 Chapter 14.in2 2 3/9/06 7:57:30 AM Hurricanes up close (continued)

4 Figure 14-3. Surges quickly cover escape routes. This warning sign is on the barrier bar road to Sunset Beach on the offshore barrier island of South Carolina. Donald Hyndman photo.

ance Program (NFIP). That program required raising dwellings west along Hugo’s track, power lines were almost completely above the 100-year flood level of 4 meters or so but provided destroyed by wind, wind-blown debris, and falling trees. Only no design requirements for wind effects. The standard build- 23 percent of customers in the Charleston area had power ing code did not require appropriate standards for coastal eight days later; some had none for two to three weeks. The wind loads until 1986. Well-designed buildings generally sur- main bridge to the mainland from Sullivan’s Island and the vived Hurricane Hugo with little damage, but others lost roof- Isle of Palms failed. ing and wall siding, or were completely destroyed. The high Hugo came ashore on a northwesterly track, just north of level of damages was caused by the lack of standards held Charleston near midnight on September 21. It weakened pro- by many groups, including governments, developers, builders, gressively so that by 1 p.m. the next day, it entered western lenders, insurers, and owners. as a Category 2 hurricane. A huge surge of Growth on the barrier islands and coast of South Carolina, 6.1 meters along the South Carolina coast caused extensive in the thirty years after the previous hurricane, was dramatic. flooding4 ( Figure 14-3), and 0.5 to 1.2 meters of sand dis- Sparsely populated areas became major beach resorts with appeared from under most buildings, less than most storms high-rise hotels and condominiums. Many of the newcomers because of the wide, flat beaches and abundant sand. The were not aware of the long history of hurricanes and their ef- waves flattened most oceanfront dunes4 ( Figure 14-1). Fif- fects along the coast. Much of the rural population in South teen to thirty meters inland of these dune fronts, overwash de- Carolina lives in mobile homes. The governor ordered the posited as much as 0.6 meter of sand. Many of the destroyed evacuation of all such homes, and many people complied. houses were built on columns sunk only 30 centimeters into The widespread pine forests helped protect many homes, but the sand and on 60-square-centimeter footings. Even on the with winds near 112 kilometers per hour, those trees began landward side of the lagoon behind the barrier island, homes falling. Fortunately, peak winds in the deadly northeast quad- were severely damaged, and pleasure boats in marinas were rant of the storm hit sparsely populated areas. Landfall 30 ki- stacked up on shore like piles of fish (see the photo at the lometers to the south would have heavily impacted Charles- beginning of the chapter). ton and multiplied the damage. In both residences and com- On September 21, 1989, residents in and around Charles- mercial buildings, much of the damage was initiated when ton, South Carolina, braced for the onslaught of Hurri- wall coverings and roofs failed because of winds. cane Hugo 4( see Figure 14-4). The National Weather Service Electric power lines and poles were undermined on the bar- forecast a 5.2-meter-high surge accompanying sustained rier islands. Even hundreds of kilometers inland to the north- winds of 215 kilometers per hour. That would completely in-

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Hyndman 0495153214 Chapter 14.in3 3 3/9/06 7:57:32 AM Hurricanes up close (continued)

the house might not survive, the Reids and their neighbor tied lengths of rope around each of them to lash to trees in case they found themselves out in the water. By 11:45, the water was 1 meter deep and the new car parked under the house between the pilings floated free; they opened its doors to keep it from rising and bashing through the floor above it. A strong smell of gasoline fumes from the cars filled the air. By 12:30 a.m., water rose above the floor inside the house. As the water continued to rise, they checked the one small uncovered “escape” window in the bathroom to see rough water, lum- Explanation N Category 3-5 ber, and branches floating by; all of the trees are broken off Category 1-2 above water level. They were terrified that they would not sur- Tropical storm vive until high tide at 2:13 a.m. when they expected the water Modified from NOAA. to begin dropping. Fortunately, the water began to drop at 4 Figure 14-4. Hurricane Hugo’s path brought it directly 1 a.m., and the wind eased a little. onshore in South Carolina, before weakening and turning north The next morning, the Reids left their neighbor’s house to though West and eastern Ontario. The colors of the storm find almost every pine tree broken off and huge live oaks with track on this satellite image relate to the intensity of the storm winds. Note that the winds weakened soon after the hurricane no leaves and few of their branches, lumber, and pieces of came onshore. houses and docks. Back at their own house, the Reids found gaping holes in every side, furniture and the refrigerator hang- ing halfway out, the decks and lower stairs gone, the floor- undate most barrier islands in South Carolina because most ing and joists of the great room gone, along with some inner are less than 3 meters above sea level. In fact, the storm, co- walls, sliding doors, and the bay window on the east. Upstairs incident with high tide, was a Category 4 with minimum pres- there was little damage. sure of 934 millibars and a forward speed of 40 to 48 kilome- The only other neighbors to remain through the storm, in ters per hour. their house about a kilometer farther west, were forced up- In March 1988, Gwenyth and William Reid completed stairs to their den, and then with water rising to chest height, their home 30 kilometers northeast of Charleston, over- they climbed onto cabinets. In the morning, when they tried to looking the intracoastal waterway which was a long boat go downstairs, they realized that the den in which they found channel excavated from lagoons behind the barrier bar. shelter was resting on the ground 10 meters from where it They took special care to build with storm-resistant design belonged. The rest of the house was gone. and materials. The year-old house was built with its floor Of the forty-two homes in the immediate area, all less than 6 meters above sea level, well anchored onto dozens of con- six years old, twenty-one were destroyed and seventeen were crete pilings pounded 3 to 4 meters into the ground. In antici- severely damaged. The four remaining homes were above pation of the storm, the Reids attached precut plywood over the level of the 6-meter surge. The beach was washed away. the windows and doors. Most neighbors evacuated, but they Those who stayed said they would never do so again. They elected to stay with one neighbor in another well-built house emphasized that you must leave, take a chain saw so you can with 300 meters of woods between the house and the water. clear trees to return quickly, keep records in pencil because By 7 p.m. the night of the storm, the wind whipped the ink generally runs, and spread family pictures and vital pa- trees over, and by 8 p.m. the area lost power. By 11:30 p.m. pers around to other parts of the country. They would build the water rose to 20 to 30 centimeters above the ground and still higher above base flood elevation and build even more the house trembled and shook in the fierce wind. Feeling that sturdily.



Hyndman 0495153214 Chapter 14.in4 4 3/9/06 7:57:34 AM Return Period (years) 9-23 48 24-32 33-45 79 46-78 >79 33 26 53 34 28 27 73 31 30 32 53 39 25 42 21 24 34 N 26 18 44 15 16 9 46 12 11 NOAA. 4 Figure 14-5. Category 3 hurricanes are strong enough to do major damage to coastal areas. They can be expected to strike almost any individual part of the coast on average every 25 to 35 years. Southern is even more vulnerable, with average return periods as low as 9 to 10 years.

Some eighty to ninety tropical storms and forty-five hur- Large hurricanes (Category 3—see Table 14-1) strike most ricanes affect the Earth every year, or 130,000 such storms locations from Florida through the Gulf Coast on aver- in a thousand years. An average of six named hurricanes age once every fifteen to thirty-five years4 ( Figure 14-5). per year form in the Atlantic and Gulf of Mexico. Thus, in a short period of geological time, cyclones are likely to have a major effect on erosion, deposition, and overall landscape Saffir-Simpson modification, especially in exposed areas such as barrier islands. Hurricane Scale For the United States, subtropical cyclones or hurricanes are a major concern along the Gulf of Mexico and southern The Saffir-Simpson Hurricane Scale is based on baromet- Atlantic coast. More than 44 million people live in coastal ric pressure and average wind speed. The lower the baro- counties susceptible to such storms, roughly 15 percent of metric pressure, the stronger the hurricane (Table 14-1). the total population of the United States (294,000,000 in We discuss below the various aspects of hurricanes, their 2005). Because of the rapid growth of these areas, more barometric pressure, wind speeds, storm surge heights, and than 85 percent of the population has never directly expe- damages. rienced a hurricane and thus is poorly informed about the Although people often focus their attention on Catego- risks. These residents and equally inexperienced develop- ries 4 and 5 hurricanes, lower-category storms can some- ers and builders choose to work in hazardous sites such as times do almost as much damage and in some cases cost beachfront dunes and offshore barrier bars. Rising property even more lives. A comparison of pairs of Category 5 and values amplify the damages when a major storm does hit. Category 2 storms can be instructive (see Table 14-2 and Although most U.S. hurricanes affect lower-latitude ar- the Cases in Point for and Hurricane eas, many of those that remain off the coast with northward Isabel). trajectories reach as far north as New England. Only a few of these have intensities greater than Category 3, but those few can be highly destructive, especially where , Formation of , and eastern protrude into the and across their paths. Based on historic ac- Hurricanes and Cyclones counts and prehistoric overwash deposits of sand covering layers of peat, such intense hurricanes wreaked havoc in New In tropical latitudes, temperatures are high and air-pressure England in 1635, 1638, 1815, 1938, and 1954. At least twenty- gradients are weak. Air rises by localized heating, which seven hurricanes of Category 1 and 2 have hit the same area causes condensation that can build into towering convec- in the last 400 years, on average one every fifteen years. tive “chimneys” with frequent thunderstorms. Where one of

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Hyndman 0495153214 Chapter 14.in5 5 3/9/06 7:57:35 AM Table 14-1 The Saffir-Simpson Hurricane Scale Barometric Average Pressure* Storm Surge Wind Speed

Category Example mbar in. m ft kph mph Damages**

Normal (no storm) 1,000 29.92 0 0 0 0 Tropical storm <1.2 <4 62–119 39–74 1 Danny, 1997 980 >28.94 1.2–1.5 4–5 119– 74–95 Minor to trees and unanchored 153 mobile homes 2 Bertha, 1996; 965– 28.5– 1.8–2.4 6–8 154– 96–110 Moderate to major damage to trees Isabel, 2003 979 28.93 177 and mobile homes, windows, doors, some roofing. Low coastal roads flooded 2 to 4 hours before arrival of hurricane . 3 Alicia, 1983; 945– 27.91– 2.7–3.3 9–12 178– 111– Major damage: Large trees down, Fran, 1996 964 28.49 209 130 small buildings damaged, mobile homes destroyed. Low-lying escape routes flooded 3 to 5 hours before arrival of hurricane eye. Land below 1.5 meters above mean sea level flooded 13 kilometers inland. 4 Hugo, 1989 920– 27.17– 4–5.5 13–18 210– 131– Extreme damage: Major damage 944 27.9 249 155 to windows, doors, roofs, coastal buildings. Flooding many kilometers inland. Land below 3 meters above mean sea level flooded as far as 10 kilometers inland. 5 Camille, 1969; 920 27.17 >5.5 >18 >249 >155 Catastrophic damage: Major Gilbert, 1988; damage to all buildings less than Andrew, 1992; 4.5 meters above sea level and Mitch, 1998 500 meters from shore. All trees and signs blown down. Low-lying escape routes flooded 3 to 5 hours before arrival of hurricane.

*Standard at sea level = 29.92 inches (in.) = 1,000 millibars (mb) = 1 bar or 1 atmosphere pressure. **These are highly variable and depend on many factors as discussed in the text.

Table 14-2 Comparison of Hurricane Categories 5 and 2 Hurricane

Characteristic Category 5 Category 2

Surge High Lower Winds High Lesser Diameter Smaller (affects smaller area) Larger (affects larger area) Speed Crosses coastline rapidly (thus shorter Crosses coastline slower (thus longer life life span on coast; dumps less rain on span on coast; often dumps more rain smaller area and less flooding) on larger area and more flooding) Example Gilbert, 1988; Andrew, 1992 Agnes, 1972; Isabel, 2003



Hyndman 0495153214 Chapter 14.in6 6 3/9/06 7:57:36 AM these convective spirals coalesces into larger systems, it de- Case in point velops into a tropical storm that may intensify into a hurri- Hurricane Camille cane. Convection may strengthen when the air rises to high elevations without strong winds aloft that can shear off the tops of the convective chimneys and cause the hurricane August 14–22, 1969, Mississippi: to dissipate. Category 5 Hurricanes begin to develop over warm seawater, com- monly between latitudes 5 and 20 degrees. Vertical wind Over western on August 15 Camille was a Cate- shear, the variation in wind speed at different elevations, gory 3 hurricane, strengthening as it moved west- must be minimal to permit a column of air to rise and main- northwest over warm waters of the Gulf of Mexico. Four tain strong circulation. A low pressure zone with cyclonic hundred kilometers south of Mobile, , this winds (rotating counterclockwise in the northern hemi- small-diameter but powerful hurricane registered a cen- sphere) becomes hurricane force when the winds exceed tral atmospheric pressure of 901 millibars and winds of a sustained velocity of 119 kilometers per hour (74 mph) more than 320 kilometers per hour. The actual maxi- where the highest wind speeds exist along the edge of the mum wind speeds are unknown because the hurricane eye wall. The warm, moist air over the ocean rises and destroyed the wind-recording instruments in the landfall spreads out at the top of the “chimney.” The rising warm air area. This Category 5 hurricane was the second strongest expands, cools, and releases latent heat; the air rises faster to ever hit the United States. Reaching Mississippi on as the storm strengthens. The center or eye of the cyclone, August 17, Camille produced a 7.6-meter storm surge, clearly visible in many satellite views 4( e.g., Figure 14-6), is becoming a tropical depression upon moving from Mis- as much as 20°C warmer than surrounding air. This convec- sissippi into western . After landfall, it weak- tive rise pulls more moist air into the eye. Coriolis forces ened rapidly but caused severe flash flooding when it initiate rotation in the rising air, the highest winds and low- shed 68 centimeters of rain in Virginia, mostly in a three- est air pressures focusing toward the core of the storm. The to five-hour period. A total of 143 people died on the whole storm may be from 160 to more than 800 kilometers Gulf Coast, and another 113 died from floods in Virginia. in diameter. Once formed, the storm moves across the Storm damage reached more than $7.1 billion (in 2002 ocean with the prevailing trade winds, a forward motion dollars). averaging 25 kilometers per hour. In the eye—generally 20 to 50 kilometers in diameter and bounded by a wind “wall”—the winds drop abruptly from, for example, 220 kilometers per hour to 15 kilome- ters per hour in the eye. The air pressure drops from normal

4 Figure 14-6. As roared into the Gulf Coast on September 15, 2004, its eye crossed the west end of the Florida panhandle while its strongest onshore winds, waves, and storm surge pounded areas just east of the eye. State boundar- ies are superimposed on this natural color

NCDC-NOAA. image.

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Hyndman 0495153214 Chapter 14.in7 7 3/9/06 7:57:36 AM Case in point

September 18, 2003, North Carolina and Virginia: Category 2 Five days before landfall at the Carolina coast, Isabel loomed as a Category 5 hurricane with a pressure of 920 millibars and maximum winds of more than 250 kilometers per hour. People expected the worst. Fortunately, however, the storm weakened dramatically before landfall, arriving at the coast as a Category 2 hurricane with maximum winds of approxi- mately 160 kilometers per hour. Tropical storm-force winds extended to more than 500 kilometers from the hurricane’s eye. Storm-surge levels reached 2 to 3 meters. One hundred thousand people were ordered to evacuate in North Carolina Mark Wolfe photo, FEMA. 4 Figure 14-8. Heavy equipment fills the breach in Hatteras Is- land, North Carolina on October 21, 2003, after Hurricane Isabel.

and another 100,000 in Virginia. In spite of the lower category rating, damages were severe. The storm covered a broad area from part of South Carolina to and made clear that lower category large-diameter storms can sometimes be almost as damaging as more energetic storms 4( Figures 14-7 through 14-10). Making landfall early the morning of September 18, Isabel severely eroded sand from beaches, destroyed roads 4( Fig- ure 14-7), toppled trees, blew the roofs off houses, and col- lapsed others 4( Figure 14-10). It opened a broad breach that severed Hatteras Island, leaving a lot of people isolated from their bridge to the mainland until the breach could be filled by heavy equipment 4( Figures 14-7 and 14-8). Many areas were without water or power for weeks. The Federal Emergency Management Agency (FEMA) reported $1 billion in damages and forty-seven deaths, mostly from flooding. Isabel continued northwest, dumping more than 12 cen- timeters of precipitation on already saturated ground and

Cynthia Hunter photo, FEMA. causing extensive flooding. It rapidly moved inland at between 4 Figure 14-7. Hurricane Isabel severed Highway 12 along 28 and 38 kilometers per hour. If its progress over the eastern Hatteras Island, North Carolina. The continuation of the highway is states had been slowed or stalled by other weather systems, visible directly across the breach to the right of the power poles. damages from flooding would have been much worse.



Hyndman 0495153214 Chapter 14.in8 8 3/9/06 7:57:38 AM Case in point (continued)

4 Figure 14-9. Sand eroded from the beach under this house during Hurricane Isabel, expos- ing most of the length of the posts that were buried in the sand. Mark Wolfe photo, FEMA.

4 Figure 14-10. This house on the beach in Kitty Hawk, North Carolina, lost its support posts during Hurricane Isabel. Mark Wolfe photo, FEMA.

H Hatteras Island http://earthscience.brookscole.com/hyndman h u r r i c a n e s a n d nor’easters 

Hyndman 0495153214 Chapter 14.in9 9 3/9/06 7:57:43 AM 160 mph Gregory, Texas 140 mph 220 km/hr (138 mph) peak gust 214 km/hr (134 mph) peak gust

192 km/hr 120 mph

160 km/hr 100 mph

128 km/hr 80 mph Eye

32 km/hr 20 mph 13 km/hr (8 mph)

Modified from Simpson & Riehl. 1 P.M. 2 P.M. 3 P.M. 4 P.M. 5 P.M. 6 P.M. 7 P.M. August 3, 1970 August 4, 1970 01Z 4 Figure 14-11. This graph for August 3, 1970 shows wind speeds in a typical hurricane in both kilometers per hour and miles per hour.

atmospheric pressure of approximately 1,000 millibars westward across the Atlantic Ocean with the trade winds. (1 bar) to 960 –970 mb in the eye. The air in the sharply They warm, pick up wind speed and energy, and often de- bounded eye sinks, causing skies to clear as the air warms velop into hurricanes before they reach the Americas. They and can hold more moisture 4 ( Figures 14-11, 14-12, and generally track west, northwest, and then north, either off 14-13). the southeastern United States or sometimes into the con- Tropical cyclones rotate counterclockwise but track tinent (Figure 14-14). Typhoons in the western Pacific and clockwise in northern hemisphere ocean basins 4 ( Fig- cyclones in the north Indian Ocean have similar tracks. ure 14-14). Cyclones rotate clockwise and track counter- Hurricanes generally curve northward as they approach clockwise in the southern hemisphere, the same direction as the southeastern coast of the United States because of the their ocean currents. Northern hemisphere tropical storms Coriolis effect, and they commonly strengthen as long as begin in warm waters off the west coast of Africa, then move they remain over the warm water of the Gulf Stream that flows northeasterly along the east coast of Florida and con- tinues up the coast past eastern Canada 4( Figure 14-15). Dry air Westward-moving storms therefore tend to track in arcs to descending the northwest and then north as they approach the coast. Wind velocity in eye = 250 km/hr As they move over cooler waters or continue over land, they gradually lose energy and dissipate. Some track fairly Pressure = straight; others take erratic paths 4( Figure 14-16). 1,000 mb An average of five hurricanes develop in the -Atlan

s tic Ocean every year, two of them major (Category 3 or Rising greater). Especially vulnerable are southern Florida, the current , and the Gulf Coast 4 ( Figure 14-17). Although hurricane season spans late June or July to November, most Wind velocity develop in August or September because this is the period = 20 km/hr with highest ocean surface temperatures. An average of nine hurricanes appear in the eastern Pacific basin each Pressure = year, four of them major. 960 mb Hurricanes in the United States cost an average of 20-30 km $700 million annually; from 1989 to early 1993, the cost was ±200 km $50 billion in hurricanes and storm surge. Rainfall of 10 cen- timeters (roughly 4 inches) per day can fall over a path 4 Figure 14-12. This schematic cross section of a typical hurricane shows atmospheric pressure (orange dashed line), wind 400 kilometers wide. If the storm stalls over an area, it can velocity (heavy black line), and air motions. dump tens of centimeters of rain per day.

10

Hyndman 0495153214 Chapter 14.in10 10 3/9/06 7:57:44 AM Eye

10-12 km Release of latent heat

Moist air Warm ocean 500-2,000 km Thomas Garrison diagram. 4 Figure 14-13. This cross-section of a typical hurricane shows both its width and height.

NORTH NORTH PACIFIC ATLANTIC 30° N OCEAN OCEAN

Equator

SOUTH SOUTH INDIAN 30° S PACIFIC ATLANTIC OCEAN OCEAN OCEAN Thomas Garrison diagram. 4 Figure 14-14. This diagram shows the tracks of typical hurricanes and other tropical cyclones. Hurricane breeding grounds are shown in orange.

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Hyndman 0495153214 Chapter 14.in11 11 3/9/06 7:57:47 AM Extratropical Cyclones, Including Nor’easters

These storms appear any time in fall, winter, or spring, but especially in February. They behave much like hurricanes and can cause as much damage. Nor’easters that strike the northeastern parts of the United States can be huge. The most historically prominent Nor’easters were in 1723, 1888, 1944, 1953, 1962, 1978, 1991, and 1993. They differ from hur- ricanes in several ways: 1. They are most common from October through April, especially February (rather than late summer for hurricanes). 2. They build at fronts where the horizontal temperature gradient is large and the air is unstable. They often form as low pressure extratropical cyclones on the east slopes of the Rocky Mountains such as in Colorado or Alberta when the jet stream shifts south during the

Modified from NOAA. winter months. Similar storms can arise in the Gulf of Mexico, near Cape Hatteras, North Carolina, or near 4 Figure 14-15. Warm Gulf Stream temperatures are shown here in red. Sequentially cooler temperatures run from yellow to or east coast of Florida. green. 3. They lack distinct, calm eyes and are not circular in form but can spread over much of the northeastern

Pennsylvania New Isabel Jersey 1953 1933 Ohio Fran Barbara 2003 1899 1996 1999 named 1996 Not Bertha named Floyd 1960 Not West Virgina Donna Not 1998 1984

named Diana Bonnie 1857

1893 named 1955 Not Virgina 1878 1985 Ione

named

Gloria

Not 1879 North Carolina 1954 named 1881 Not Carol Hugo

1954

1989 Notnamed

Isabel 1896 Hazel Storm Intensity South Carolina 2003 Category 3-5 named Category 1-2

Not Tropical storm Tropical depression 1899 Extratropical storm named Not Modified from NOAA. 4 Figure 14-16. This map shows hurricane tracks across North Carolina from 1857 to 2003. The colors of the storm tracks indicate the category of the hurricane near the eye.

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Hyndman 0495153214 Chapter 14.in12 12 3/9/06 7:57:55 AM center of the storm, this drops the surface pressure and increases storm strength. 6. Damage is concentrated along the coast, whereas much of the damage from hurricanes is farther inland. With strong winds from the northeast, they typically batter northeast-facing shorelines. Nor’easters can build when prevailing westerly winds carry N these storms over the Atlantic Ocean and if the jet stream is situated to allow the storms to intensify. The annual number of Nor’easters ranges from twenty to forty, of which one or two are typically strong or extreme. In addition to the direct damage from high winds, a Nor’easter also generates high waves and pushes huge vol- umes of water across shallow continental shelves to build Total number of up against the coast as a storm surge. Low barometric pres- direct and indirect impacts sure in the storm permits the water surface to rise, creat- 21-25 ing a higher storm surge. Extreme surge heights can result 16-20 from coincidence with especially high tide or movement 11-15 of surges into bays. As with the surges that accompany hur- 6-10 ricanes, these flood low-lying coastal plains and overwash 0 200 miles 1-5 beaches, barrier islands, and dunes. As with hurricanes, the 0 greatest damages occur when a major storm moves slowly 0 200 kilometers at the coast or hits a coast already damaged by a previous

NOAA, National Weather Service, and FEMA. storm. 4 Figure 14-17. In this map, the total number of hurricanes A classification scale for Nor’easters by Davis and Dolan to strike coastal counties from Texas to Maine can be seen for the (1993) approximately parallels that of the five-category Saf- period 1900–94. More intense hurricanes also concentrate along fir-Simpson hurricane scale, except that the emphasis is on the coasts with the largest number of hurricanes. beach and dune effects rather than wind speeds and surge heights. It infers a “storm power index” based on the maxi- mum deepwater significant wave height (average of the United States. As recognized in the late 1700s by Ben- highest one-third of the waves) squared multiplied by the jamin Franklin, smaller, counterclockwise-rotating storm duration (Table 14-3). cyclonic weather systems are embedded in the broader Nor’easter wave heights are commonly 1.5 to 10 meters, overall flow. with energy expended on the coast being proportional to the square of their height. Thus a 4-meter wave expends 4. Named for the direction from which their winds come, four times as much energy as a 2-meter wave. Wave height they bring heavy rain and often heavy snowfall. Frank- depends on fetch, or the distance a wave travels over the lin also noted that precipitation begins in the south and water. Waves with a long fetch and constant wind direc- spreads northward along the coast. tion in a slow-moving storm can therefore be much more 5. They are cold-core systems that do not lose energy with destructive than those in a stronger, fast-moving storm with height. If jet stream winds move mass away from the variable wind directions. Where the storm center is well

Table 14-3 Dolan-Davis (1993) Nor’easter Scale Maximum Deepwater Significant Average Wave Height Duration Most Common Class (meters) (hours) Site of Formation Example Storms

I (Weak) 2 10 II 2.5 20 III 3 35 IV 5 60 Bahamas or Florida December, 1992; March 1993 (“Storm of the Century”) V (Extreme) 6.5 95 Bahamas or Florida March 7, 1962 (Ash Wednesday); Halloween 1991 (“The Perfect Storm”)

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Hyndman 0495153214 Chapter 14.in13 13 3/9/06 7:57:59 AM offshore, the highest waves may be just reaching the coast after the clouds and rain have passed. When high waves are stacked on top of a storm surge, the effects are magnified. As with hurricanes, a storm surge de- pends on the lower atmospheric pressure of the storm per- mitting water level to rise, coupled with the mound of water pushed ahead of the wind. A severe Nor’easter can remain in place for several days and through several tide cycles; high tide superimposed on a high storm surge can be extremely destructive. Examples of Class V storms include the Ash Wednesday storm of 1962 and the Halloween storm of 1991. The Ash Wednesday Storm of March 7, 1962, was a high latitude Nor’easter along the Atlantic coast of the United States; it stayed offshore approximately 100 kilometers, paralleling the coast for four days. The storm began east of South Carolina and migrated slowly north and parallel to the coast before moving farther offshore at New Jersey. Its slow northward progress was blocked by a strong high pressure system (clockwise rotation) over southeastern Canada. It affected 1,000 kilometers (620 miles) of coast and caused more than $1.8 billion in damages (in 2002 dollars).

Sustained winds over the open ocean were 72 to 125 ki- Peter Shugert photo, U.S. Army Corps of Engineers. lometers per hour (45 to 78 mph) and produced waves as 4 Figure 14-18. Storm waves batter this seawall at Sea Bright, high as 10 meters. Storm waves of 4 meters on top of a 1- to New Jersey, during the 1991 Halloween Nor’easter. 2-meter storm surge washed over barrier sandbars that had been built up for years. A series of five high tides aggravated the height of the surge. Damage included extensive beach and dune erosion and the creation of dozens of new tidal ■ Huge storm waves may overwash dunes and impact inlets. Almost all of heavily urbanized Fenwick Island, Dela- coastal structures. ware, was repeatedly washed over by the waves. The coast- ■ Heavy rain causes river flooding, flash floods, land- line moved inland by 10 to 100 meters. slides, structural damage, and overflow of storm The huge Halloween Nor’easter of October 1991, also sewers and sewage systems. Fifty-nine percent of called “The Perfect Storm,” appears to have had 10.7-meter the people who die in hurricanes drown because of high deepwater waves and lasted for almost five days. Its freshwater floods. One-quarter of hurricane deaths are wave crests were especially far apart, with intervals rang- from people who drown in their cars or while trying ing from ten to eighteen seconds between crests, so they to abandon them during floods. The heaviest rainfalls moved much faster than most storm waves. Accompanied are from slower-moving storms and those with larger by a major storm surge, it caused heavy damage from south- diameters (see “Case in Point: ” ern Florida to Maine, especially in New England ( Fig- 4 and “Case in Point: ”). The National ure 14-18). Hurricane Center predicts the total rainfall in inches by dividing 100 by the forward speed of the storm in Winter Windstorms and Heavy Snow miles per hour. Inches of rainfall = 100 Snow depth on the ground is one measure of the severity of storm’s forward speed in mph a winter storm because of snow loading and accompany- For example, ing building collapse. Snow depths are typically greatest in Inches of rainfall = 100 = 5 inches of rain Maine, northern Michigan and Wisconsin, and western New 20 mph York, occasionally exceeding a meter. Heavy snow can ■ High winds, including tornadoes, damage windows, even fall in southern states such as Alabama and roofs, and entire buildings. They disrupt transportation (see “Case in Point: Superstorm, March 1993”). and utilities and create large amounts of debris. Torna- Hazards initiated by both tropical cyclones and extra- does can form near the eye wall or well away from the tropical storms include the following: center of the hurricane. Although more tornadoes are ■ Storm surges are well above normal tides and cause reported than confirmed, they are difficult to confirm , salinization of land and groundwater, because hurricane winds can reach speeds similar to coastal erosion, damaged crops and structures, and those in tornadoes. Most of the physical damages in hur- drowning. ricanes are caused by winds.

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Hyndman 0495153214 Chapter 14.in14 14 3/9/06 7:58:00 AM Case in point Case in point Superstorm, March 1993 Tropical Storm Allison

“Storm of the Century” June 5 to 11, 2001: Tropical Storms On March 12 to 13, a springtime storm off the coast Can Be as Damaging as Hurricanes of Texas moved east off the coast, its central Like most other tropical storms or hurricanes, Allison rose pressure dropping to 984 millibars. Moving rapidly to- off the coast of Africa and moved west across the Atlan- ward Florida at between 64 and 80 kilometers per hour, tic. It crossed Mexico into the eastern Pacific on June 1, the northern part of the squall line then accelerated to doubled back into southeastern Mexico and north 112 kilometers per hour. It generated a storm surge that through the western Gulf of Mexico. It made landfall on raised sea levels by 2.7 to 3.5 meters along the Florida the east end of Galveston Island, Texas, late on June 5. panhandle near Apalachicola, decreasing to 2 meters The cyclonic storm drifted slowly inland to 200 kilome- at Tampa. It also spawned at least fifteen tornadoes ters north of over the next thirty-six hours, drop- and numerous downbursts. It moved north-northeast ping more than 25 centimeters of rain in southeast Texas through Georgia on March 13 with a central pressure and adjacent Louisiana by the morning of June 8. of 971 millibars, then north along the Atlantic coast. Weakening of a high pressure center off Florida and Wind gusts reached 175 kilometers per hour west of Key strengthening of a high over New Mexico caused Alli- West and later 231 kilometers per hour on Mount Wash- son to loop east, then southwest to Houston a second ington, . Precipitation was only 2.5 to time. Another 51 centimeters of rain fell in twelve hours 7.5 centimeters from the Gulf Coast to Maine, but snow- to cause the worst flood on local record. Twenty-two fall generally ranged from 15 to 60 centimeters and up to people drowned in the Houston area. In total, the storm 1.5 meters along the North Carolina–Tennessee border. dumped 94 centimeters of rain, almost 1 meter, on the In Alabama and northern Georgia, areas not used to such Port of Houston in less than one week. Twenty-one centi- conditions, hundreds of roofs collapsed under heavy, wet meters of that came within two hours in this area, which snow. Fallen trees and high winds left more than 3 mil- has notoriously poor drainage. Damages in the Houston lion people without electrical power. area alone reached $5 billion. The Texas Medical Cen- Central pressure dropped to 960 millibars over Ches- ter was especially hard hit. Its below-ground floors were apeake Bay before rising to 966 millibars over Maine. flooded. Backup generators were above ground, but un- Based on storm surge height and minimum atmospheric fortunately switches between the two systems were below pressure, the “superstorm” was equivalent to a Cate- ground and destroyed by the flooding. gory 3 hurricane. Its total circulation area was the size of Central Louisiana did not fare much better with up to the contiguous forty-eight states. All interstate highways 75.8 centimeters of rain at Thibodaux. From there the north of Atlanta in the eastern United States were closed. storm strengthened as it moved east, dumping 30 centi- Some 270 people died, with forty-eight more missing meters of rain on Gulfport, Mississippi; 25 centimeters on at sea. Along the Outer Banks of North Carolina, 200 Tallahassee, Florida; and more than 30 centimeters near homes were heavily damaged, and on Long Island at least Columbia, South Carolina. It dumped 53 centimeters of eighteen homes fell into the sea. Total damage amounted rain on Morehead, North Carolina, and then continued to $5.7 billion. up the coast to dump more heavy rain, including more than 25 centimeters in some places in eastern Pennsylva- nia. It finally moved offshore in Maine.

■ Immediately following the storm, communication lines are lost, power lines are down, roads are out, and a cade. Since 1920, the early warning systems and evacuations broad range of urgent needs overwhelm local govern- of populations have reduced the number dramatically but ments. Salt, sewage, various chemicals, and bacteria it still amounts to hundreds every decade. In spite of the contaminate surface water and groundwater. Many warnings and evacuations, the costs have increased six- local officials are inexperienced in dealing with large- to tenfold because of increasingly heavy development in scale disasters and with the programs available for coastal areas. Less obvious costs not generally recorded assistance. Coordination between all levels of govern- in damage reports include loss of business, cleanup costs ment and teamwork is critical to recover from such to individuals, and job and wage interruption. Govern- disasters. ments, communities, and insurance companies are finally The number of deaths in the United States because of tropi- beginning to react to damages and costs. They are begin- cal cyclones before 1910 was in the thousands every de- ning to push for safer communities that are less vulnerable

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Hyndman 0495153214 Chapter 14.in15 15 3/9/06 7:58:00 AM Case in point Hurricane Agnes

June 1972: Major Flooding from a Minor Susquehanna were 1.5 times larger than the previously known Hurricane along the maximum flood. The peak discharge at Harrisburg, Pennsylva- nia, was 28,900 cubic meters per second; that at Conowingo, Agnes was not much of a hurricane—actually, it was only a Maryland, was 32,000 cubic meters per second. Peak flows tropical storm by the time it reached New England, though it on many rivers in Virginia also exceeded 100-year levels. had an immense diameter of 1,600 kilometers. On June 15, 1972, Hurricane Agnes grew in the Gulf of Mexico, moved north though the Florida panhandle on June 19, spun off fif- teen tornadoes, then weakened to the intensity of a tropical depression as it continued over Georgia, the Carolinas, and out into the Atlantic Ocean. There it again strengthened to a tropical storm and continued north. On June 22, its center moved inland over southern and , where it stalled from June 20 to June 25 and dumped 10 to 48 centimeters of rain, the largest amounts in the Susquehanna Basin 4( Figures 14-19 to 14- 21). June 1972 was the wettest month on record for both Penn- sylvania and New York, at 21.6 and 28.5 centimeters, respec- tively, both amounting to more than twice the normal annual precipitation. Agnes arrived in New England when the ground was already saturated from earlier rains. More would have to run off the surface without soaking in. Floods on the Susque- Susquehanna River Basin photo. hanna and Schuylkill rivers reached 200-year levels, the great- 4 Figure 14-19. In 1972, Hurricane Agnes flooded Wilkes- est flood since 1784 when records began. Peak flows on the Barre, Pennsylvania.

4 Figure 14-20. The 1972 Susquehanna River flooding of Wilkes-Barre, Pennsylvania,

Pennsylvania Army National Guard photo. was extensive.

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Hyndman 0495153214 Chapter 14.in16 16 3/9/06 7:58:02 AM Case in point (continued)

4 Figure 14-21. Flood waters surge under the bridge in the 1972 flood. P. Muse photo. P.

Flood-control reservoirs on the west branch of the Susque- of its annual flood damage. As described for other hurricanes, hanna helped reduce flood heights by as much as 1 to 2 me- damages included flooding of homes and businesses, public ters, but even there the peak flows set records. For the 25,000- water and sewage facilities, and industrial and public utility square-kilometer area east of the Appalachians to the Atlantic plants; crop loss; and the disruption of jobs and commerce. coast, precipitation from Agnes exceeds all others except for Water was rationed in some towns. Fires that broke out in two Florida hurricanes in 1916 and 1950. The amount of many places were left to burn because floods made them sediment carried by the Susquehanna and Schuylkill rivers inaccessible. during this single flood was three times the average annual load. Overbank deposition of sand and mud was widespread What Went Wrong? on major streams. A slow-moving tropical storm with a huge diameter followed Until 2001, Agnes was tied for third costliest among major previous rains that saturated the ground. That low pressure hurricanes. Only Hugo in 1989 and Andrew in 1992 caused storm cell pulled huge amounts of Atlantic Ocean moisture more damage. However, except for increases in populations into Pennsylvania and adjacent areas. and property values, Agnes would be second only to Andrew. Fifty people died in Pennsylvania, and damages were $9 bil- lion (in 2002 dollars), mostly from flooding. Twenty-four died in New York, and damages were more than $3 billion. Nine- teen died in Maryland, and damages came to $4.75 billion. Thirteen died in Virginia. Agnes ranks fifth among twentieth- century hurricanes in damages to the northeastern states, al- most entirely from flooding. Clearly, a weak (low category) hurricane can do as much damage as an especially strong one. A large-diameter weak hurricane wreaks havoc primarily because of freshwater flooding rather than high winds, waves, and surge. The Susquehanna River that drains much of Pennsylvania and adjacent New York and Maryland drains less than 1 per- cent of the continental United States but averages 6 percent H

Pennsylvania

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Hyndman 0495153214 Chapter 14.in17 17 3/9/06 7:58:04 AM and incur reduced costs from coastal hazards—“disaster- resistant communities.’’ Policies used include land use plan- ning, building codes, incentives, taxation, and insurance. However, because tourism is the largest source of income for most coastal areas, most governing bodies are reluctant either to publicize their vulnerability or place many restric- tions on anything related to tourist income.

Storm Surges

Storm surges, also called storm tides, occur when the low atmospheric pressure over an area of a major storm permits the sea level to rise. Because pressure of the atmosphere pushes down on the water surface, the height of the storm surge rises with lower atmospheric pressure (Sidebar 14-1). In addition, prolonged high winds push seawater into huge mounds as high as 7.3 meters and 80 to 160 kilometers wide. The surge wave moves more or less at the speed of

the storm 4 ( Figure 14-22). The pileup of water ahead of National Weather Service photo. the wind is higher with greater wind speed and fetch length 4 Figure 14-22. As the storm surge moves inland, the sea level and with shallower water (Sidebar 14-2). The mound of rises to cover large low-lying areas. water ahead of the storm wind slows down and piles up as it enters shallow water at the coast. Shallower water of the continental shelf forces the offshore volume of water Sidebar 14-1 into a smaller space, causing it to rise. A bay, inlet, harbor, or river channel that funnels the flow of water against the h = 43.3 – 0.0433 P0 coast also causes the surge mound to rise. Even the Great where Lakes are large enough to build storm surges 1 to 2 me- h = height of surge (in m) ters high. P = pressure in eye of hurricane (in hPa or millibars) The recurrence of a particular surge height is generally estimated from past experience in the same way that recur- rence intervals are estimated from floods on streams (see Sidebar 14-2 Chapter 11, “Streams and Flood Processes,” pages 285 and 290). Recurrence intervals for surge heights are estimated (height)2  wind speed  (fetch length 2 water depth) from the historic surges measured from tidal gauges in a Specifically given time period. A major problem, as with recurrence in- 0.0625  w  L  D tervals of any hazard such as earthquakes or floods, is hav- h =   ing a sufficiently long time to record the largest events. The d g calculation of surge height recurrence interval (R) is shown and in Sidebar 14-3. h  1/atmospheric pressure Surge height can be plotted against recurrence interval where on semilog paper with values falling on a nearly straight line w = wind speed (m/sec) that can be projected to larger values that have not yet been L = fetch length (m) recorded 4( Figure 14-23). D = water depth (m) Thus, as with other hazards, there are numerous small d = density of salt water surges, fewer large surges, and only rarely a giant surge. g = gravitational constant (980 cm/sec2) They are subject to a power law. Inverting the recurrence in- terval equation provides the probability of a surge of some height being exceeded. The probability (P) of a surge of a Sidebar 14-3 given height being exceeded (the exceedence probability) is shown in Sidebar 14-3. In this case, the probability can be R = (n 1 1) / m = Recurrence interval plotted (on probability paper) against the surge height. P = m  100 / (n 1 1) = Exceedence probability As with any 100-year recurrence interval event or other where infrequent event, the timing of the next event of similar size m = rank of the surge event in the total record is an average. It may not be far away. It could be the next n = number of years of record month or next year. In fact, the largest events tend to cluster

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Hyndman 0495153214 Chapter 14.in18 18 3/9/06 7:58:04 AM 7

6 Example (for a particular area)

(m) 5

4 height 3 Winds Surge 2 blowing N to NE towards quadrant 1 shore

0 1 5 10 20 50 100 200 Recurrence interval in years (log scale) 4 Figure 14-23. Like other recurrence intervals, a linear plot of surge heights to recurrence intervals on a log scale commonly plots near a straight line. Winds blowing offshore in time, perhaps because of a “forcing mechanism” that in- fluences or causes the hazard. The level of surge hazard depends on a variety of factors 4( Figure 14-24). Because sea level rises rapidly during the onset of a storm surge, low-lying coastal areas are flooded and people drown. In fact, 90 percent of all deaths in tropical cyclones result from storm surge flooding (see Fig- ures 14-22). Contrary to most people’s expectations, the highest surge levels are not at the center of the hurricane but satellite image. NASA Terra in the north to northeast quadrant of the hurricane eye wall 4 Figure 14-25. The northeast quadrant of hurricane winds 4( Figure 14-25). Because hurricanes rotate counterclock- are directed toward the shoreline and inflict more damage; south- wise, winds in that quadrant point most directly at the shore east quadrant winds are directed offshore and inflict least dam- age. Hurricane Isabel, 2003, is shown here as an example. State and cause the greatest effect there. The forward movement boundaries are superimposed on this natural color image taken of the storm also enhances these winds because they blow at 11:50 a.m. EDT on September 18, 2003. in nearly the same direction that the storm is moving. Winds south of the eye of the hurricane are moving offshore and have the least effect. The shape of the shoreline (in map view) also has a The path of the hurricane compared with orientation of major effect on the height of the storm surge. Bays or in- the shore also has an effect. A hurricane arriving perpendic- lets, for example, can focus the storm surge mound into a ular to the coast can lead to a higher storm surge because smaller area, causing it to rise higher with resulting greater the whole surge mound affects the shortest length of coast. damage. Although people may feel more protected by liv- One arriving at a low angle to the coast is spread out over a ing along the side of an inlet rather than along the open greater length of shoreline but can build higher waves from coast, the surge height in such a location may actually be a longer fetch. higher.

Surge mound Surge moves inland

e.g., 7 m Dunes Mean sea level 4 Figure 14-24. This Lagoon < 3 m diagram shows some of the effects of a storm surge on a Barrier bar or island barrier island.

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Hyndman 0495153214 Chapter 14.in19 19 3/9/06 7:58:09 AM The forward speed of the storm center can have mixed effects. A faster storm movement pushes the storm surge into a higher mound that submerges the coast in deeper water, but slow-moving hurricane cells often inflict more overall damage because they remain longer over a region to dump greater rainfall and cause more landward flooding. Similarly, a larger-diameter hurricane also dumps greater rainfall because it impacts a larger area. It can also build higher waves because of longer fetch and build a wider surge mound because it pushes the mound of water over a larger area. The inland reach of storm surge waters depends on a vari- ety of factors. Most coastal areas of the southeastern United States and Gulf of Mexico stand close to sea level, so there is little to prevent surge flooding inland. However, inland progress of storm surge waters is slowed dramatically by the presence of vegetation and dunes. Because surge waters Orrin Pilkey photo. flow inland like a broad river, they are slowed by the height 4 Figure 14-27. (Category 3) in September of coastal dunes, especially those covered with brush, and 1996 moved the beach shoreward and carried huge amounts of by near-shore forest. Areas where dunes are low or absent sand (white) across the narrow barrier island and into the lagoon behind North Topsail Beach, North Carolina. Dark ridges border- or where vegetation has been removed permit surge waters ing the road are railings on small bridges across low areas that to penetrate well inland. Thus, people who lower dunes or provided easy access for storm waters. remove vegetation to improve their view or ease of access to the sea invite equally easy access from any significant storm surge, along with the severe damage that it brings. In many cases, pedestrian paths across dunes to get to the A storm surge, finding a low area through dunes, or an beach foster sites of erosion and overwash. That damage area of little or no vegetation, will flow faster through the includes the destruction of buildings, roads, bridges, and gap, eroding it more deeply. Subtle low areas invite over- piers, along with contamination of groundwater supplies wash of sand eroded from the beach toward the lagoon with saltwater, agricultural and industrial chemicals, and 4( Figures 14-26 and 14-27). Deeper gaps may sever the sewage. Saltwater can invade aquifers and corrode buried barrier island when a breach forms. That not only destroys copper electrical lines. roads and houses but isolates homes and towns so that they have no road access to the mainland 4( Figure 14-8). Buildings, bridges, and piers can be washed away by surge currents and by waves, or they can float away if not well anchored to foundations, or if the foundation is under- mined by waves. Because larger waves feel the bottom at greater depth, they stir bottom sand and erode more deeply, undermining pilings and foundations. For this reason, most low-lying coastal homes are raised high on posts to be above the most frequent storm surge heights 4 ( Figure 14-28). Coastal houses are often built 4 meters off the ground on posts to raise them above the level of storm surges and waves. Aside from being a good idea, building codes that address flooding generally require it. Unless well braced, these posts may snap because of lateral forces on the walls above. Even if structurally sound, the house may settle when waves accompanying high storm surges undermine the piers on which the house is built. Because a storm surge locally raises sea level, moves in- land as a swiftly flowing current, and raises the height of wave attack, it amplifies all of the erosional aspects ofa storm. Anything that can float will do so more readily; any-

USGS photo. thing loose will be moved more easily by the waves. Houses are essentially big boxes full of air, so whole houses can 4 Figure 14-26. Overwash tongues of sand spread behind a vegetated dune crest at Camp Lejeune, North Carolina, after Hur- be floated off their foundations and transported inland, of- ricane Bertha (Category 2). ten breaking up in the process. Thus, the nature and qual-

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Hyndman 0495153214 Chapter 14.in20 20 3/9/06 7:58:11 AM Donald Hyndman photo. M. Wolfe photo, FEMA. 4 Figure 14-28. Houses in hurricane-prone areas are built on 4 Figure 14-31. This roof was lifted off a house in Kitty Hawk, posts 4 meters high to minimize damage from storm waves and North Carolina, by the storm surge from Hurricane Isabel in Sep- surges. These are in North Myrtle Beach, South Carolina. tember 2003. Jimmy Oland photo, U.S. Army Corps of Engineers. Dave Gatley photo, FEMA. 4 Figure 14-29. This house in Princeville, North Carolina, was 4 Figure 14-32. Hurricane Camille’s surge lifted this sailboat not well anchored to its foundation. The surge from Hurricane and carried it inland to collide with a house. Apparently the boat Floyd lifted the house and deposited it on top of the family car. sustained less damage than the house. Orrin Pilkey photo. U.S. Army Corps of Engineers, Galveston office. 4 Figure 14-30. This house, at Carolina Beach, North Caro- 4 Figure 14-33. Surge flooding during (low lina, was not well anchored to its slab. The surge accompanying Category 3) in August 1983 drowned houses to their eaves in Bay- Hurricane Fran (Category 3) in 1996 carried it off its slab and onto town, 51 kilometers inland from Galveston, Texas. a road.

ity of construction is important in minimizing damage. The When the surge comes at high tide, the resulting sea level building foundation should be well anchored to the ground rises still higher, with correspondingly greater reach inland such as through deeply embedded strong piles. The floors and greater damage 4( Figures 14-32 and 14-33). Although and walls should be well anchored to the foundation and flooding compounded by water rise from storm surge can the roof well anchored to the walls with “hurricane clips” be catastrophic, wind damage is often ten times as great 4( Figures 14-29, 14-30, and 14-31). (see “Case in Point: Galveston Hurricane”).

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Hyndman 0495153214 Chapter 14.in21 21 3/9/06 7:58:14 AM Case in point galveston Hurricane

September 8, 1900 roofs, and pieces of houses flew through the air. A wood railroad bridge broke loose and moved inland, sweeping up In 1900, the science of meteorology was in its infancy. Weath- buildings and debris like a giant bulldozer. Injured people ermen in Galveston, Texas, were crudely tracking the hurri- waded and climbed through debris to reach sturdy buildings cane as it moved northwest over Cuba to south of Louisiana. on the highest ground. Those in sturdy buildings retreated to Because there were no planes or satellites, much of the track- the upper floors as the water rose. An estimated 1,000 people ing was provided by radio reports from ships at sea. They ex- survived in the elegant Tremont Hotel. pected that it would swing northeast to move up the eastern Early the morning of September 7, the steamship Pensacola United States as most of them did. However, a stationary high left Galveston harbor, heading east for Pensacola, Florida. pressure cell over Florida forced it to swing west instead—to- Captain Simmons was not aware that storm warnings were ward Galveston. The city was a prosperous center of shipping issued for Galveston Island thirty minutes after departure. and resort activity, and huge 4.5-meter-high sand dunes along Shortly after leaving the harbor, he ran into high seas and the edge of the city had been removed to provide better beach winds but continued east. That evening he dropped anchor, access. High water had spilled into the city in 1875 and 1886 but the chain broke in the huge waves so the ship was adrift for but without doing much damage. The highest part along the all of the next day. When Simmons finally regained control of crest of the island was only 2.5 meters above sea level. the ship he headed back, reaching Galveston on September 9, The local weather bureau had been receiving storm warn- only to find battered ships and thousands of dead bodies. ings from headquarters in Washington, D.C., for a couple of The hurricane, with winds up to 193 kilometers per hour days, but the first sign of a change was a heavy swell from during a high tide, created a 6-meter storm surge 4 ( Fig- the southeast, beginning in the afternoon of September 7. By ure 14-34). It was a Category 4 storm upon landfall. The off- 4 a.m. the morning of September 8, an especially high tide shore barrier island on which the city is built was completely flooded the low parts of town, but the barometer had dropped covered with 3 to 5 meters of water. Waves and winds de- only a little. Later that morning, people enjoyed watching the stroyed boats, bridges, more than half of the wooden build- big surf until skies began to darken, winds strengthened, heavy ings, and even some brick ones. The only thing that saved rain fell, and the barometer dropped. The water rose to cover some of the remaining business district six blocks back from bridges to the mainland, and the rough weather precluded the beach was a wall of debris from the shattered buildings using boats. By the time people realized that it was a hur- closer to the beach 4( Figure 14-35). At 8:30 p.m., the ba- ricane, they were trapped on the island. Houses crumbled in rometer hit bottom at 28.5 inches (723 mm). Thousands the waves, debris filled the streets, and roofing slates, whole evacuated before the storm, but 8,000 to 12,000 died, mostly

4 Figure 14-34. This map shows the S storm surge that overwhelmed Galveston t orm Tr Island in 1900. The northwest trend of a ck the storm track is shown as a dashed white

NOAA. line in the lower left.

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Hyndman 0495153214 Chapter 14.in22 22 3/9/06 7:58:19 AM Case in point (continued)

by some 3 meters and built a giant seawall along the beach- front of the city. The seawall has grown in length over the years and is now 16 kilometers long. As would be expected, the beach in front of the wall largely disappeared. Galveston regularly dumps truckloads of sand over the seawall to pro- vide a narrow beach. West of the west end of the seawall, rapid development in the permitted homes to be built on the beach at an average elevation of only 1.5 meters. Hur- ricane Alicia, a Category 3 storm that arrived in 1983, de- stroyed or severely damaged ninety-nine of 207 homes on the beach. Although Texas law claims all land seaward of the veg- etation line, lawsuits and pressure from real estate groups led the state and county to relent and provide building permits to

State of Texas photo. State of Texas repair and reoccupy damaged homes. Permits have also been provided for additional new homes on the beach near the Figure 14-35. The 1900 Galveston hurricane piled up debris 4 west end of Galveston Island so that there are now 100 or so from buildings closer to the coast into a huge ridge that partly protected those behind. more beachfront homes than before Hurricane Alicia. Those houses were built on lots that sold for an average of $200,000 each. Beachfront dunes built since Alicia were washed away in the storm surge. Survivors marooned with the loss of their by Tropical Storm Frances in 1998. New developments on the only bridge to the mainland lacked water, food, medical sup- west end of Galveston Island are now as vulnerable as Galves- plies, and electricity. The third of the city closest to the Gulf ton was before the 1900 hurricane. completely disappeared. Along its landward edge was a ridge A storm equivalent to that of 1900 would likely bring a of debris that included the remains of 3,600 houses. Innu- storm surge 4.6 meters high at the seawall to 7.6 meters at merable bodies were found in the jumbled debris; seventy a the north (inland) edge of Galveston Island. Seawater would day turned up for a month. In the hot, humid weather, the be 1.5 to 3 meters deep in buildings in the center of town. stench of rotting bodies was overwhelming. Survivors doused West of the seawall, all 300 beachfront homes would be de- the bodies with oil and burned them on the spot because they stroyed, their wreckage becoming battering rams that would could not be buried in the water-saturated ground. Looting destroy homes landward of them. Destruction of the built was rampant until martial law was imposed five days later. environment is certain; the number of people who die de- Damages, in 2002 dollars, amounted to $14.4 billion. pends on the number who evacuate in time. It will take almost After destroying Galveston, the hurricane weakened as thirty-six hours to evacuate those at risk. The population of it continued north through the Great Plains, then turned coastal counties in the area was 1.6 million in 1961; it is now northeast across the Great Lakes, New England, and eastern almost 5 million, a large proportion being new residents who Canada before heading out to the Atlantic Ocean on Septem- have no experience with hurricanes. ber 15. Then again on August 16, 1915, another Category 4 hurricane, with tides 3.6 meters above normal, surged over Galveston’s new seawall and flooded the business district to a depth of 1.8 meters. Two hundred seventy-five people died from flooding and high winds. Before 1900, people believed that the greatest dangers from a hurricane were the huge waves and that those would be minimized by shallower water offshore. They were not aware that most people drown from the high water of the storm surge or that the huge mound of water is caused by low atmospheric pressure amplified by motion of the storm and restriction of water depth on the continental shelf. Nor did they understand how destructive a hurricane could be, so most did not try to evacuate until it was too late. To provide protection from future hurricanes, Galveston and the U.S. Army Corps of Engineers raised the island surface H http://earthscience.brookscole.com/hyndman h u r r i c a n e s a n d nor’easters 23

Hyndman 0495153214 Chapter 14.in23 23 3/9/06 7:58:20 AM vidual hurricanes. Many beachfront homes are completely Waves and Wave Damages destroyed when the sand beneath them is washed offshore. Others nearby sustain major wind and wave damage 4( Fig- Higher waves impact the coast with much more energy. ures 14-41 and 14-42). They stir up sand to greater water depths both offshore and The width and slope of the continental shelf has a signifi- onshore, moving the sand farther offshore on gentler slopes. cant effect on wave damage. On a wide, gently sloping con- Thus, they erode sand from beaches and dunes, undermin- tinental shelf offshore, the waves drag on bottom and stir ing any structures there 4 ( Figures 14-36 to 14-38). Loose up sand; this uses up more wave energy before the waves debris carried by waves amplifies the damage. Boards, reach land, decreasing the damage. Large amounts of mov- branches, logs, and propane tanks act as battering rams ing sand on a shallow bottom offshore reduce the wave en- against buildings. Loose debris collected against building ergy available for coastal erosion. On a narrow continental pilings strongly enhances the wave forces against the sides shelf, as in the outer banks of North Carolina, or a steeper of a structure 4( Figures 14-39 and 14-40). slope offshore, larger waves and breakers maintain their The level of damage at a particular site can be quite dra- energy as they approach closer to shore, thereby causing matic as shown in photographs taken before and after indi- more damage.

Dune crest

Berm

Mean high tide

Mean low tide

Profile A Normal wave action

Erosion Accretion

Mean high tide

Profile A Mean low tide Profile B Initial attack of storm waves

Erosion Accretion

Mean high tide

Profile A Mean low tide Profile C Storm waves attack foredune

Crest lowering Erosion

Accretion 4 Figure 14-36. This series of diagrams shows the Mean high tide effects of a storm wave attack on a beach and dune. Mean low tide Note the progressive erosion of original shore Profile Profile A A, in part because of waves on higher sea level of Profile D After storm wave attack, normal wave action

storm surge. Modified from Skeggs & McDonald, and Waterways Experiment Station.

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Hyndman 0495153214 Chapter 14.in24 24 3/9/06 7:58:21 AM T. Harrington photo, FEMA.

4 Figure 14-37. on November 5, 1999, eroded A. Llamare photo, U.S. Army Corps of Engineers. much of the sand from the beach in front of Breakers Resort, Mel- 4 Figure 14-40. This beachfront hotel at Panama City, Florida, bourne Beach, Florida. It came close to undercutting and destroy- was severely damaged by in 1995. ing the buildings.

Winds and Wind Damages

Although the Saffir-Simpson Scale is designed to indicate the intensity of a hurricane, it can be misleading as an indi- cator of the level of expected damage. A hurricane impact scale is more appropriate for that purpose based on the factors below. In addition to the wind speed, the amount of damage from a hurricane is heavily dependent on the height of water rise from the storm surge, how large an area

Dave Gatley photo. is covered, the duration of high water and high winds, and 4 Figure 14-38. on September 1, 1999, how recently another storm has affected the area. eroded the beach out from under these beachfront homes in Kitty Wind can blow down trees, power lines, signs, and wreck Hawk, North Carolina. weak buildings; it can fan wildfires and destroy crops. It can blow in windows, doors, and walls and lift the roofs off houses. Damages by winds are greatly magnified by flying debris 4( Figures 14-43 to 14-48). Wind velocity also has a major effect on wave height. Wind does by far the greatest damage to buildings, much more than flooding, although significant damage results from rain entering the structure after minor wind damage. The lowest-level hurricane winds at 119 kilometers per hour apply approximately 73 kilograms per square meter (15 lb/ft2) of pressure on the wall of a building. Thus, a force of 1,360 kilograms (3,000 lbs) would press against a wall 2.4 meters high and 7.6 meters long. If the wind speed dou- bles, the forces would be four times as strong; so in a Cate- gory 4 hurricane at 240 kilometers per hour, the force on the same wall would be 5,400 kilograms (12,000 lbs). Reduced pressure caused by the same winds on the downwind side of the building adds to the problem because the winds pull Dave Gatley photo. against the wall 4 ( Figure 14-47). Roofs often fail before 4 Figure 14-39. An unsecured propane tank that ripped walls because of additional factors. The largest wind forces loose acted as a battering ram during on Septem- ber 17, 1999. Aggressive erosion of sand under the house supports are caused by suction. Where a roof slopes toward the wind, dropped this house at Long Beach, Oak Island, North Carolina, the air is forced up and over the roof, lifting it in the same onto the sand, effectively destroying it. way that air flowing over an arched airplane wing lifts the

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Hyndman 0495153214 Chapter 14.in25 25 3/9/06 7:58:23 AM 4 Figure 14-41. These photos show part of North Topsail Beach, North Caro- lina, (a) after Hurricane Bertha on July 16, 1996, and (b) after Hurricane Fran on September 7, 1996. The area is hardly recognizable. 1

2

3

(a)

1: Now gone.

2: Pushed off foundation, into new inlet to left.

3: Pushed off foundation; several houses to right are demolished or gone. USGS photos. (b)

plane. A steeper-sloped roof actually performs better in windows and exterior doors help more than anything else high wind than one sloped more like an airplane wing. because those are the vulnerable points of entry. Impact The lifting forces under overhanging eaves tend to cause resistance is also important for windows and doors. Tem- failure there first. Hip roofs sloping to all sides and- lack pered and laminated glass windows are significantly better ing overhangs deflect the wind best. Larger roof spans are than ordinary window glass. Where more than 50 percent more vulnerable. Roof material also makes a difference. of a wall is windows or exterior doors, the wall is especially Shingles fare poorly because they can easily blow off dur- vulnerable. Skylights are especially susceptible to penetra- ing high winds. Metal, slate, or tile roofs are good; a single- tion. Double-wide garage doors, particularly if overhead membrane roof is better; and a flat concrete tile roof is doors, are unusually susceptible because the track holding much better. Concrete or steel beams supporting the roof the door may fail or the wind may force the door out of the are better than wood. track. Unreinforced brick chimneys fail in large numbers, Sidewalls and windows are commonly sucked out rather even where against a backup wall, because of poor attach- than blown in. Keep this in mind when anchoring roofs, ment to the wall. Brick, stone, or reinforced concrete block walls, and window coverings. When windows or doors walls, however, are much stronger than wood-sheathed fail because of flying debris, pressure increases inside the walls. Because much of the damage is from flying debris, building, and the whole roof may be pulled off 4( Figures gravel or roof-mounted objects on nearby buildings are 14-47 and 14-48). Shutters or plywood well anchored over dangerous.

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Hyndman 0495153214 Chapter 14.in26 26 3/9/06 7:58:27 AM 4 Figure 14-42. These houses on Topsail Beach, North Carolina, show ex- tensive damage (a) after Hurricane Bertha on July 16, 1996, and (b) after Hur- ricane Fran on Septem- ber 7, 1996. 1

2

3

(a)

1: House floated off its foundation, back onto road

2

3: House destroyed, as are houses to right. USGS photos. (b) U.S. Army Corps of Engineers. 4 Figure 14-43. Hurricane Alicia (Category 3) in October 1983

removed the beach sand from under the concrete parking area be- FEMA photo. low this house on the Texas Gulf Coast, leaving it suspended on the pilings that raised the house above surge level. It also peeled 4 Figure 14-44. In some places, entire roofs were lifted off off much of the roof and the front half of this house. these Florida houses during on August 24, 1992.

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Hyndman 0495153214 Chapter 14.in27 27 3/9/06 7:58:32 AM Evelyn Shanahan photo, NOAA. 4 Figure 14-45. Yes, hurricane winds can be high! The danger of wind-blown debris is vividly illustrated by a palm tree near

Miami, which was impaled by a sheet of plywood during Hurricane U.S. Army Corps of Engineers, Galveston office. Andrew in August 1992. This may have been caused by an embed- ded tornado. 4 Figure 14-48. Hurricane Alicia (Category 3) in October 1983 destroyed most houses near this beach along the Texas Gulf Coast. The house at top, just left of center, survived well because of its nearly flat roof with no overhangs and few windows, as well as its location (in the third row of houses back from the beach).

Rainfall and Flooding

Hurricanes not only cause severe beach and dune erosion by waves and associated surge action but also generally cause significant flooding because the storm is a strong low pressure weather system. Small-diameter or fast-moving storms cover a small area and pass over an area quickly, so they do not generally cause major flooding. Large- diameter or slow-moving hurricanes spend much more time over an area and typically drop large amounts of rain Photographer unknown. over large parts of a drainage basin, and for a longer period, 4 Figure 14-46. Debris flying in hurricane winds can be dan- so they cause more extensive and more prolonged flood- gerous. A sheet of plywood used to cover a window came loose to ing. Hurricane Agnes, only a tropical storm when it came become a guillotine in Hurricane Frederick along the Gulf of Mexico back on land in Pennsylvania and New York in 1972, spread coast in 1979. over a diameter of 1,600 kilometers and provided the largest rainfall on record. Heavy rain can not only cause flooding but also wash out structures from flooding streams, drown people, contaminate water supplies, and trigger landslides. Wind lift Several centimeters of rain dumped over a few hours col- lect rapidly and run off slowly because of the gentle slopes Wind pressure of coastal plains. Draining downslope, the water collects to even greater depths to cause catastrophic floods in low areas. A good example is Hurricane Floyd in 1999 follow- ing on the heals of Hurricane Dennis, which had already Surge waves saturated the ground (see “Case in Point: Hurricanes Dennis wave impact and Floyd, 1999”). Piers in sand Although the circumstance may be unusual, the addi- (undermined by waves) tional load of a large surge mound on the Earth’s crust may Mean sea level be sufficient to trigger an earthquake in an area already under considerable strain—as in the Tokyo earthquake of 4 Figure 14-47. This diagram shows the wind, wave, and surge 1923 in which 143,000 people died, mainly in the cyclone- effects on a coastal building on a barrier bar. fanned fire that followed the rupture of gas lines.

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Hyndman 0495153214 Chapter 14.in28 28 3/9/06 7:58:35 AM Case in point Hurricanes Dennis and Floyd, 1999

Hurricane Dennis, a Category 3 storm, moved up the East eroded by storms in the past decade. Hundreds of buildings Coast offshore beginning August 30, wandered back and now rest on the seaward-sloping beachfront where they are forth erratically for a few days, then made landfall as a much directly exposed to storm attack, but the houses would have weaker tropical storm on September 4 4( Figure 14-49). Un- to be removed to replace the old dune. Hurricane Dennis re- like many hurricanes that move quickly across the shoreline, moved sand from beneath some buildings and stranded oth- minimizing the time available for wave damage, Dennis re- ers below high tide level. mained 125 kilometers off the North Carolina coast for days. Ten days later, from September 14 to 18, Hurricane Floyd hit It generated big waves that progressively eroded the beaches the East Coast from South Carolina to New Jersey 4( Figure 14- through a dozen high tides. Sand overwashed the Carolina 49). However, it was only a strong Category 2 hurricane by the Outer Banks at numerous points, and some islands moved time it reached the U.S. mainland near Cape Fear, North Caro- a little farther landward. Erosion was equivalent to that of a lina, on September 16. Buildings on Oak Island, largely de- Category 4 hurricane. stroyed in a hurricane in 1954, had been rebuilt in their origi- A large frontal dune built in the 1930s for erosion control nal locations well back from the beach. After forty-five years along 150 kilometers of beachfront had been progressively of landward beach migration, some 20 to 45 meters in total,

Virginia

Kitty Hawk North Carolina Albemarie Sound N

Greenville 0 40 miles Hatteras Island 0 40 kilometers

Pamlico Sound Cape Hatteras

Core Banks

Cape Lookout Atlantic Ocean Wilmington

Dennis 1999

Onslow BayBonnie 1998 Long Topsail Island Beach

Cape Fear

Fran 1996 Bertha 1996 Floyd 1999

4 Figure 14-49. This map shows the erratic path of Hurricane Dennis and the nearly straight path of Hurricane Floyd, back-to-back storms in 1999.

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Hyndman 0495153214 Chapter 14.in29 29 3/9/06 7:58:37 AM Case in point (continued) Dave Gatley photo. 4 Figure 14-50. Sand eroded from under the shallowly an- chored posts under this house, causing it to topple during Hur- ricane Floyd on September 17, 1999, at Long Beach, Oak Island, North Carolina. U.S. Army Corps of Engineers, 4 Figure 14-51. Hurricane evacuation traffic comes to a standstill during evacuation for Hur- half of them were again destroyed by Floyd 4( Figure 14-50). ricane Floyd. Note that a few people are outside Its big waves came on top of a 1.5- to 2.5-meter storm surge. their stopped cars. On Topsail Island, a sheet of overwash sand covered the low, thin island. The artificial frontal dune along much of the island, constructed from sand bulldozed from the beach, largely disappeared. The dune had been replaced at least five inoperable. Military helicopters and emergency personnel in times in the previous ten years. After Hurricane Fran destroyed boats rescued thousands of people from flooded houses, the roads, utility lines, and septic systems in 1996, Floyd again rooftops, and even trees. Almost every state from Florida to largely destroyed them. They will again be replaced—primarily was declared a major disaster area. at federal taxpayer expense. Floyd covered a larger area and lasted longer than many At least seventy-seven people died, most of those in flood- larger hurricanes, so its heavy rains lasted much longer. The ing. Damages were in the billions of dollars. Some 2.6 million storm dumped more than 50 centimeters of rain on coastal people evacuated from Florida to the Carolinas, the largest North Carolina, an area where Dennis had saturated the such evacuation in U.S. history. At the peak of the evacuation, ground only two weeks earlier. Floyd’s torrential rains had almost every east-to-west highway was jammed with traffic, nowhere to go but to run off the surface. Flood levels from some almost at a standstill 4( Figure 14-51). On Interstate eastern North Carolina to New Jersey rose above the 100-year 26 west of Charleston, South Carolina, both directions were flood stage4 ( Figure 14-52). converted to only westbound traffic to handle the vehicles. The maximum surge was 3.1 meters on Masonborough Is- Some people took two and one-half hours to cover fifteen land, North Carolina. The Tar River crested 7.3 meters above miles. Most gas stations and restaurants were closed. flood stage, and most roads east of Interstate 95 flooded. At least 110,000 hogs drowned, along with more than a Twenty-four-hour rainfall totals reached 34 centimeters in million chickens and turkeys in this agricultural region. Pea- Wilmington, North Carolina, and 35.5 centimeters at Myr- nuts, cotton, tobacco, and crops were severely tle Beach, South Carolina 4 ( Figure 14-53). Total rainfall damaged. Water everywhere was a stinky mess. Drinking water along part of the coast reached 53.3 centimeters. As if that was contaminated, and flooded water-treatment plants were was not enough, with rivers still high, 15 more centimeters

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Hyndman 0495153214 Chapter 14.in30 30 3/9/06 7:58:38 AM Case in point (continued)

of rain fell on eastern North Carolina, causing still more flooding. Heavy runoff carried sediment, organic waste, and pesticides from farms; hazardous chemicals from industrial sites; and raw sewage into coastal lagoons and bays and onto beaches. According to FEMA, this was the worst flood disaster ever recorded in the southeastern states. For many people, the trauma and mess of the storms were just the beginning. Many thousands of dollars of appliances, computers, stereo equip- ment, clothing, and other belongings were ruined beyond re- pair. Far more than half of the people flooded out did not have flood insurance. A common reaction was that “No one told me I was in a flood area” or “I didn’t know my insurance didn’t cover floods.” USGS photo. 4 Figure 14-52. Heavy rains accompanying Hurricane Floyd submerged much of eastern North Carolina. The U.S. 64A bridge at Tarboro, North Carolina, is isolated by floodwaters. Think about trying to evacuate after you finally realized that the rivers were really going to flood your house. You might make it to the local highway, or even to the freeway—but then what? Dave Gatley photo. 4 Figure 14-53. This family returns to its almost completely submerged home in a community near the Tar River just north of Greenville, North Carolina. H

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Hyndman 0495153214 Chapter 14.in31 31 3/9/06 7:58:40 AM ■ approximately 8,000 in Honduras from Hurricane Fifi Deaths in Hurricanes from September 15 to 19, 1974; Deaths in hurricanes depend not only on strength of the hur- ■ 7,192 in and Cuba from from Sep- ricane—that is, the wind velocity and surge height—but tember 30 to October 8, 1963; and also on several unrelated factors. Obvious problem areas ■ more than 6,000 at Pointe-a-Pitre Bay, Haiti, on Septem- are buildings that are close to the coast, buildings that are ber 6, 1776. close to sea level, and weakly constructed buildings such as mobile homes. Less obvious problems are people’s lack of awareness of the level of hazard involved in a hurricane and the wide range of hazards involved in such events. Finally, a large population in the path of the storm cannot evacu- ate quickly or efficiently, especially if an accident blocks a heavily used highway. If people fail to evacuate before the storm arrives, high surge levels can flood roads under meters of water, making escape impossible. Fallen trees, power lines, and other debris can block roads, or the surge may cover the roadway, making escape impossible and rescue difficult 4( Figures 14-51, 14-52, 14-54, and 14-55). Many people de- lay their evacuation because of the inconvenience and cost or because they spend time purchasing and installing materials to help protect their homes from the storm. Oth- ers delay evacuation until the last minute, thinking it will take them only an hour or two to drive inland. However, only single two-lane bridges to the mainland serve most barrier islands. Those bridges and roads become snarled with traffic, and accidents can cause further dangerous delays. A shift of as little as 80 kilometers in the Galveston 1900 Texas Department of Transportation photo. Texas hurricane could have resulted in far fewer deaths. That distance is typically the National Hurricane Center’s cur- 4 Figure 14-54. Some traffic still tried to evacuate after Tropi- rent twenty-four-hour lateral forecast error for the path of cal Storm Francis in 1999 began to move in. a hurricane. Recall that a shift of 1992’s Hurricane Andrew just 32 kilometers to the north would have caused two or three times as much damage. Sixty-four kilometers to the south would have resulted in little monetary loss in the minimally populated (see “Case in Point: Hur- ricane Andrew”). The most difficult area for evacuation is the Florida peninsula, which is only a few meters above sea level and everywhere less than 200 kilometers across. A hurricane can easily cross the whole state without losing much strength. Population growth has been rapid, especially along the coast, and it is difficult to predict the precise path of a hurricane. The deadliest Atlantic hurricanes have been in the Greater and ; those areas have had 64 per- cent of the total losses. Before Mitch in 1998, Mexico and Central America had 15 percent of the total deaths and the United States mainland 20 or 21 percent. Major catastrophes in Central America include large death tolls:

■ some 10,000 in Nicaragua and Honduras from Department of Transportation photo. Texas from October 22 to Novem- 4 Figure 14-55. Traffic was blocked in 1999 as a storm surge ber 5, 1998; from Tropical Storm Francis began to move in.

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Hyndman 0495153214 Chapter 14.in32 32 3/9/06 7:58:41 AM Case in point Hurricane Andrew

August 24–27, 1992: Category 5 have been a Category 5—and with a 5.2-meter surge in sea level. The low pressure cell that would become Andrew began as As Andrew crossed west into the Gulf of Mexico, winds thunderstorms over western Africa that then moved west over again picked up to 193 kilometers per hour before the storm the Atlantic. It strengthened to tropical storm status by Au- again went onshore as a Category 3 hurricane in a sparsely gust 17. On August 21 and 1,600 kilometers off Florida, the populated part of the south-central coast of Louisiana and disrupting upper-level winds died down, allowing the growth nearby Mississippi 4( Figure 14-56); 1,250,000 people evac- in the cloud height and increased wind velocities. A deep uated low-lying areas of Louisiana. Fifteen deaths occurred high pressure system developed over the southeastern United before the storm dissipated as it moved farther inland to the States that extended eastward to north of the storm, permit- north. Once again, Andrew’s devastation would have been ting Andrew to gain strength. By August 22, it had grown into much worse if its course had shifted it toward New Orleans, a hurricane with winds more than 119 kilometers per hour. where dikes protect much of this huge city below sea level. Strengthening was rapid. Over the northern Bahamas on Sixty-one people died, and 88,000 buildings and thou- August 23, winds reached 240 kilometers per hour. On Au- sands of cars were destroyed. In 2002 dollars, the storm did gust 24, the storm reached Dade County, near Miami, Flor- $35.8 billion in damage, $28 billion of it in Dade County. It ida, with a central pressure of 922 millibars, the third lowest was the most expensive natural disaster in U.S. history, but pressure recorded in the twentieth century 4( Figure 14-56). it could have been worse. If Andrew’s track had been 30 or Sustained winds reached 281 kilometers per hour, but local 35 kilometers farther north, damages would have been two or vortices reached 322 kilometers per hour. This storm was three times as high. If it had been 65 kilometers south, in the originally thought to be a Category 4 but is now known to Florida Keys, dollar losses would have been much lower.

4 Figure 14-56. Hurricane Andrew’s eye passed over Miami and the Gulf of Mexico, then looped just west of New Orleans, Louisiana, on August 26, 1992, before turning inland to the northeast.

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27

26

25 24 NOAA GOES satellite image.

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Hyndman 0495153214 Chapter 14.in33 33 3/9/06 7:58:46 AM Table 14-4 Hurricane Deaths in the United rising as high. However, those characteristics do not make States, 1900–2004 these islands safe. Because many of them are low-lying, they are especially vulnerable to severe wind damage. Hurricane Location Year Category Deaths

Galveston, Texas 1900 4 >8,000 Southeast Florida 1928 4 1,836 Poor Countries: Florida Keys, south Texas 1919 4 600 Different Problems New England 1938 3 600 Florida Keys 1935 5 408 In contrast to developed countries, poor countries have dra- Southwest Louisiana, 1957 4 390 matically different problems, many of which seem almost north Texas (Audrey) insurmountable because of poverty, culture, and disastrous Northeastern United States 1944 3 390 land use practices. Much of Central America, for example, Grand Isle, Louisiana 1909 4 350 is mountainous with fertile valley bottoms that are mostly New Orleans, Louisiana 1915 4 275 controlled by large corporate farms. Many people have big Galveston, Texas 1915 4 275 families that survive on little food with marginal shelter; un- able to afford land in the valley bottoms, they live in poorly built dwellings. They decimate the forests for building ma- The largest numbers of deaths in U.S. hurricanes from 1900 terials and fuel for cooking, leaving the slopes vulnerable to 2004 are shown in Table 14-4. Note that no recent hur- to frequent landslides. Others migrate in search of work to ricanes make the list. Part of the reason is better forecasting towns in valley bottoms where they crowd into marginal and warning systems, as well as better transportation facili- conditions on floodplains close to rivers that are subject to ties. Another part of the reason may be the lesser hurricane flash floods and torrential mudflows fed from the denuded activity between 1970 and 1995. slopes. Hurricane Mitch, which was Category 5 offshore but The costliest U.S. hurricanes from 1900 to 2004 are shown weakened rapidly to tropical storm status onshore, provides in Table 14-5. Note that all but one of the costliest hurricanes a dramatic and tragic example of what can happen (see have occurred since 1954. Costs reflect the rapidly growing “Case in Point: Hurricane Mitch”). populations along the coasts, more building in less suitable Poor countries in which low-lying coastal areas attract locations, and more expensive buildings. and provide food for large populations also have severe It might seem that low-lying, subtropical islands such as problems. The delta areas of large rivers in Southeast Asia Grand Cayman in the Caribbean and Guam in the western support large numbers of people because the land is kept Pacific would be especially vulnerable to storm surge and fertile by the frequently flooding rivers. As those popula- wave damage. However, fringing coral reefs force storm tions grow, and as heavy land use in the drainage basins of waves to break well offshore, minimizing those effects. Wa- those rivers leads to more frequent and higher flood levels, ter depths offshore of the reefs tend to be deep, and absence people clamor for protection from the ravages of the floods. of a wide continental shelf prevents the storm surge from Both governments and local groups build more and higher

Table 14-5 Costliest Hurricanes in the United States, 1900–2004 Insured Total Estimated Rank Hurricane Date Location Loss* Loss†

1 Andrew 1992, Aug. Florida, Louisiana 20.807 35.82 2 Charley 2004, Aug. Florida, Carolinas 6.755 11.82 3 Hugo 1989, Sept. Georgia, Carolinas, Puerto Rico, 7.69 10.55 4 Ivan 2004, Sept. Alabama, Florida, Georgia, 12 others 6.0 10.5 5 Agnes 1972, June Florida, northeast U.S. 9.32 6 Betsy 1965 Florida, Louisiana 9.22 7 Frances 2004, Sept. Florida, Georgia, Carolinas, New York 4.4 7.7 8 Camille 1969, Aug. Mississippi, Louisiana, Virginia 7.57 9 Georges 1998, Sept. Alabama, Florida, Puerto Rico, Virgin Islands, Louisiana, Mississippi 3.35 6.53 10 Diane 1955 Northeast U.S. 6.0 11 Jeanne 2004, Sept. Florida, Pennsylvania, Georgia, S. Carolina, Puerto Rico 3.245 5.68 12 Floyd 1999, Sept. Carolinas, New Jersey, Virginia, Florida 2.226 4.778

* In billions of 2004 dollars. Figures from Insurance Institute of America and NOAA. † Estimated loss assumed as 1.75 times insured loss. Older losses recalculated using U.S. Dept. of Commerce Price Deflator.

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Hyndman 0495153214 Chapter 14.in34 34 3/9/06 7:58:47 AM levees (see “Case in Point: Cyclones of Bangladesh and Cal- does nothing, of course, to prevent erosion. Piers may cutta, India”). be undercut, and the eroding beach will eventually move landward from under the structure, causing its collapse. Building Restrictions Human alterations of dunes and mangrove stands 4 ( Fig- ure 14-57) that would increase potential flood damage are Significant destruction of homes and other structures in prohibited. Even walking on dunes is generally prohibited historic hurricanes has caused some states such as North because it disturbs the sand and any vegetation covering Carolina to dictate a setback line based on the probability it, thereby making the dune more susceptible to erosion by of coastal flooding. Seaward of this line, insurance compa- both wind and waves. People build elevated walkways to nies will not insure a building against wave damage. In spite cross the dunes to the beach ( Figure 14-58). of challenges, the courts have so far upheld the building 4 prohibition. The National Flood Insurance Reform Act of 1994 re- quired federal mapping of areas that are subject to river or coastal floods. The purpose was to implement a Flood In- surance Rate Map (FIRM) provided by FEMA. The special flood hazard areas that were designated have a 1 percent chance of being flooded in any given year, that is, they are comparable to the 100-year floodplain of streams. Coastal communities wishing to participate in the NFIP must use maps of these flood hazard areas when making develop- ment decisions. Coastal areas subject to significant wave action in addition to flooding are more vulnerable to dam- age. Significant waves are considered those higher than 1 meter. Therefore, National Flood Insurance Program con- struction standards are to be more stringent in such coastal zones. National flood insurance premiums are to be higher for those who live in more vulnerable areas. Flood insurance costs in 2003 for single-family dwellings built after 1981, with no basement and raised at least 4 feet above mean sea level, were generally $450 per year for the first $50,000 of replacement value and $145 per year for an additional $50,000. As with stream flooding, there is a thirty- Donald Hyndman photo. day waiting period after purchase before the insurance 4 Figure 14-57. Mangroves live in the brackish water of takes effect. Given that hurricanes are not predictable for a lagoons, anchoring their roots in limestone bedrock. These dense specific location for more than a day or two in advance, it thickets slow the inland advance of storm surges. would seem prudent to maintain flood insurance if you live in an area of possible storm surge. Some undeveloped areas were protected by the Coastal Barrier Resources Act of 1982, which prohibited federal incentives to development and prohibited the issuance of new flood insurance coverage. However, in areas not cov- ered by that act, flood insurance remained available for el- evated structures located as far seaward as the mean high- water line, regardless of local erosion rates. Coastal building standards for the National Flood Insur- ance Program require the following: ■ All new construction be landward of mean high tide. ■ All new construction and major improvements must be elevated on piles so that the lowest floor is above the base flood elevation for a 1 percent chance of being Donald Hyndman photo. flooded in any year. Figure 14-58. Walkways and stairs cross a former dune to ■ 4 Areas below the lowest floor must be open or have minimize erosion and reduction of dune height. However, this breakaway walls. Fill for structural support is prohib- South Carolina dune was completely eroded away by a small ited. Raising the lowest floor above 100-year flood level spring storm.

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Hyndman 0495153214 Chapter 14.in35 35 3/9/06 7:58:48 AM Case in point Hurricane Mitch

October 24 to November 4, 1998: 60 centimeters of rain per day, with storm-total rainfalls as high as 1.9 meters. After several days of wandering over Cen- Nicaragua and Honduras tral America, a weakened Mitch turned northeastward across A major hurricane impacts the poorest countries the hard- Yucatan and over the Gulf of Mexico, where it strengthened est. Mitch was the fourth strongest since to tropical storm status before pounding Florida’s 1900, with a minimum central pressure of 905 millibars. It on November 4–5. formed as a tropical storm in the southwestern Caribbean Larger towns throughout Central America concentrate in Sea on October 21, moved slowly northwestward to reach valleys near rivers, where businesses and homes were flooded, hurricane strength on October 24, rapidly strengthening to buried in mudflows, or washed away4 ( Figure 14-60). Most Category 5 from October 26 through 28. Maximum sustained of the damage and deaths were related to the rains rather surface winds reached 290 kilometers per hour. Weakening than wind or tidal surge. Mitch was the deadliest hurricane in somewhat, Mitch hovered near the north coast of Hondu- the western hemisphere since 1780; it killed more than 11,000 ras before moving southwest and inland as a tropical storm people in Central America, most in floods and mudflows. on October 29 4( Figure 14-59). Waves north of Honduras Whole villages disappeared in floodwaters and mudflows, probably reached heights of more than 13 meters. For the and 18,000 people were never found. More than 3 million next two days, the storm continued westward over Hondu- others lost their homes or were otherwise severely affected. ras, Nicaragua, and then Guatemala, producing torrential During and after the storm, there were critical shortages rains and floods. Some mountainous areas received 30 to of food, medicine, and water. Dengue fever, malaria, chol- NOAA satellite image. 4 Figure 14-59. Hurricane Mitch, October 26, 1998, neared Honduras with winds at 180 miles per hour. Its cloudless eye is well defined. The storm track is shown as a green line that starts on the lower right and progresses to the upper right over this two-week period. Compare Figure 16-17.

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Hyndman 0495153214 Chapter 14.in36 36 3/9/06 7:58:49 AM Case in point (continued) USGS photo. USGS photo. 4 Figure 14-60. Many homes in Honduras were buried by 4 Figure 14-61. Washed out bridges crippled transportation mudslides. and the distribution of food and fuel. This truck collapsed a bridge across the Manacal River—its underpinnings were weakened by incessant rains.

C a r ib b e a n S e a Figure 14-62. This map details the MEXICO 4 MEXICOMEXICO C a r i b b e a n S e a deaths and damages from Hurricane Mitch GUATEMALA following its path across Central America. HONDURAS 258 deaths 6,600 deaths 120 missing Belmopan 8,052 missing 15,700258 affecteddeaths Belmopan 6,6002,100,000 deaths affected 120 missing 8,052 missing 98 bridges destroyed BELIZE 15,700 affected BELIZE 170 bridges destroyed 60% of roads impacted 2,100,000 affected 70% of roads impacted 98 bridges destroyed 170 bridges destroyed 60% of roads impacted 70% of roads impacted GUATEMALA GUATEMALA HONDURAS Guatemala Guatemala City Guatemala City Tegucigalpa City San Tegucigalpa NICARAGUA 2,055 deaths SanSalvador Salvador 2,0552,055 deaths deaths 1,0841,084 missing missing 868,000 affected EL SALVADOR 868,000 affected EL SALVADOR NICARAGUA 71 bridges destroyed EL SALVADOR NICARAGUA 70% of roads impacted EL 239SALVADOR deaths 71 bridges70% of roads destroyed impacted 135239 deaths missing Managua 135 missing 70% of roads impacted 84,00084,000 affected affected

N 1717 bridges bridges destroyed destroyed N o 20% of roads impacted o r 20% of roads impacted r t t h h P P a COSTA RICA RICA a c c i f i f i c San f i San Jose c O c SanJose Jose O c e c e a n a n Impacts on Agriculture Impacts on Agriculture Impacts on Agriculture PANAMAPANAMA Nicaragua – 30% – 30%of of banana crop destroyed crop destroyed Guatemala – 45-60% – 45-60% of corn cropof corn destroyed crop destroyed Honduras – 90% – 90% of banana of banana crop destroyed crop destroyed USAID map.

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Hyndman 0495153214 Chapter 14.in37 37 3/9/06 7:58:51 AM Case in point (continued)

era, and respiratory illnesses were widespread. Roads were 6 percent of farmable land. Large corporate farms took over impassable 4( Figure 14-61), and helicopters for distributing most of the fertile valley floors and gentle slopes for grow- relief supplies were in such short supply that some areas did ing cotton, , livestock, and irrigated crops. Peasants not receive help for more than a week. Survivors surrounded were forced onto steep slopes where they cleared forests for by mudflows had to wait days for the mud to dry enough for agriculture, building materials, and firewood; this caused in- them to walk to rescuers. creased soil erosion and the addition of sediment to rivers. A large percentage of all crops were destroyed, including Those who cannot survive by growing crops on those slopes most of the banana and melon crops, as were shrimp farms in move to cities in search of jobs. Lacking access to safe build- Honduras. and other crops in Nicaragua, Guatemala, ing sites there, they build shelters on steep, landslide-prone and El Salvador suffered severe damage. Big agricultural com- slopes or flood-prone riverbanks. panies that employed many of the people lost huge areas of Improved hurricane forecasts are of limited use for these farmland, so they had to lay off many employees. Damages poverty-stricken people. Even if warned of approaching came to more than $5.5 billion in 2002 dollars in Honduras storms, most are reluctant to leave what little they own. In and Nicaragua, two of the poorest countries. It will take de- addition, they lack the resources to leave and have no way cades for these nations to get back to where they were before to survive when they get there. As a result, they are extremely Hurricane Mitch 4( Figure 14-62). vulnerable to such natural hazards. Many people live and work on the floodplains of large riv- ers and are used to flooding in hurricane season almost ev- ery year. When the river rises, they pull their furniture to the roof overhang, leave the house, and set up temporary shelters along a nearby raised highway until the water recedes in a couple of weeks. This time, Mitch took away nearly everything and left behind several feet of mud 4( Figure 14-60). With the help of government bulldozers and endless determination and hand labor, they try to put their lives back together. Was the devastation of Hurricane Mitch a freak event that is not likely to repeat itself? Unfortunately, the combi- nation of rapid population growth, widespread poverty, and lack of access to usable land makes Central America increas- ingly vulnerable to natural disasters. In 1995, 75 percent of Guatemala’s and 50 percent of Nicaragua’s populations were living in poverty, defined as living on less than $1 per day at 1985 prices. Those levels were worse after Hurricane Mitch. H In 1974, 63 percent of Honduran farmers had access to only

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Hyndman 0495153214 Chapter 14.in38 38 3/9/06 7:58:53 AM Case in point Cyclones of Bangladesh and Calcutta, India

The Bay of Bengal rather than in the cities, and few rail lines connect the larger cities. Roads are narrow and crowded with heavy trucks, Bangladesh and the northern coastal region of India around buses, and rickshaws. Bridges span only a few of the smaller Calcutta have seen repeated terrible death tolls from tropi- river channels. People get around on bicycles, small boats, or cal storms. These vast delta regions are low-lying and espe- ferries. Traffic jams in the cities are frequent on normal days. cially fertile—and one of the most densely populated regions Imagine the chaos of trying to evacuate hundreds of thou- on Earth, with some 130 million people in an area not much sands or millions of people with a couple of days’ warning more than the size of New York state. People are exceptionally given such limited transportation. poor; their livelihoods are based directly on agriculture and Often there is adequate satellite warning to evacuate pop- therefore intimately tied to weather and its associated haz- ulations in the region, but most people do not leave because ards. The delta lands on which people live and farm are virtu- they believe that others will steal their belongings, they have ally at sea level 4( Figure 14-63). Most people live on farms lived through one major cyclone, and the average time be- tween cyclones suggests to them that the next major one “will not come for many years,” or if they die it is “God’s will.” The problem is enormous: ■ In October 1737, 300,000 died in a surge that swept up the Hooghly River in Calcutta. ■ In 1876, 100,000 died in another surge near the mouth of the Meghna River and thousands more in 1960 and 1965. ■ In November 1970, cyclone winds of 200 kilometers per hour accompanied a 12-meter surge that swept across the low-lying delta of the Ganges and Brahmaputra rivers in Bangladesh. Four hundred thousand people died, many of them in the span of only twenty minutes. Whole villages disappeared, along with all of their people and animals. ■ Again, on April 30, 1990, a cyclone with 145-mile-per- hour winds and a 6-meter surge swept into Bangladesh, drowning 140,000 people. The 1990 population of Bangladesh of 111 million is projected to double in thirty years, placing millions more on the delta. ■ On June 6, 2001, nearly 100,000 people were stranded up to their chests in water following heavy monsoon rains. Villages were flooded when a flood protection -em bankment failed, and rail service was disrupted when the floods swept away a small bridge. Catastrophic floods in Bangladesh are caused by several fac- tors. The heavy monsoon rains from April through October are carried by warm, moist Indian Ocean winds from the southwest and magnified by the orographic effect of the air mass rising against the Himalayas. The rains are torrential and widespread in the drainage areas of the Ganges and Brahma- putra rivers, which come together in the broad delta region of Bangladesh. Rivers swell annually to twenty times their nor- mal width. Those same drainage areas have been subjected

NASA. to widespread deforestation and plowing of the land surface, 4 Figure 14-63. The delta of the Ganges River in Bangladesh is which causes massive erosion and heavy siltation of river laced by numerous distributary channels and intervening land that channels. The decrease in channel capacity causes the rivers is virtually at sea level (view to south, some 150 kilometers across). to overflow more frequently.

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Hyndman 0495153214 Chapter 14.in39 39 3/9/06 7:58:55 AM Case in point (continued)

In the delta region of Bangladesh, gradual compaction and of riverbeds to improve navigation and build homes for flood subsidence of delta sediments coupled with gradual rises in victims on the new levees. Unfortunately, the impetus appears sea level compound the problem. Relative sea level rise com- to be to improve food production rather than safety and will pared with the delta surface raises the base level of the rivers, do little to prevent the problem. Ironically, it is those same reduces their gradient, and raises the water level everywhere floods that bring new fertile soils to the land surface. Dredg- on the delta. Cyclone-driven storm surges can put virtually the ing will increase the chances of flooding downstream; and the whole delta—75 percent of the country—underwater in a few new levees, built from those fine-grained materials dredged hours 4( compare Figure 14-64). from the delta’s river channels, will be easily eroded during Given that people live on the sea-level delta of two major floods. Levee breaches will lead to avulsion of channels, wide- rivers and in the path of frequent monsoon floods and fre- spread flooding, and destruction of fields. One useful sugges- quent tropical cyclones, their options are few. The government tion is to construct high-ground refuges and provide flood- plans to dredge and channelize more than 1,000 kilometers warning systems.

4 Figure 14-64. When flooded, the Mekong delta of Vietnam is underwater as far as you can see. The Ganges and Brah- maputra river deltas in Bangladesh also go underwater with the flooding and sea-level rise accompanying a tropical storm surge. International Red Cross photo.

H

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Hyndman 0495153214 Chapter 14.in40 40 3/9/06 7:58:57 AM However, with still no national building code, state and lo- them, sometimes dramatically. Satellite sensors can moni- cal governments are responsible for enforcing their own tor those thermal anomalies. Hurricane prediction, like any codes. Some southeastern states have no statewide building weather prediction, has significant uncertainty. Storms are codes at all. At the time that Hurricane Hugo hit South Caro- monitored by weather satellites and by “hurricane hunter” lina in 1989, half of the area of the state, including parts of aircraft that make daily flights into the storms to collect data the coast, had no building codes or enforcement at all. This on winds and atmospheric pressures. Within two to four lack of building codes results in much more widespread days of expected landfall, they drop twenty to thirty 1-pound and severe destruction of property. dropsonde sensing instruments into the storm from 30,000 Most people agree that buildings should be built more to 40,000 feet. These transmit, wind, temperature, pressure, strongly. Developers, builders, local governments, and and humidity information, their fall being slowed by small many members of the public, however, often oppose such parachutes. The path of the storm is commonly controlled increased standards, especially those for winds. Their argu- by nearby high and low pressure systems. ment is that such regulations unnecessarily increase the Early warning in the United States, using weather satel- cost of housing and limit economic development in the lites, allows people to evacuate by road or to reinforced area. But studies by the research center of the National high-rise buildings, such as those in Miami Beach. The Na- Association of Home Builders indicate that homes can be tional Hurricane Warning Center tries to give twelve hours made much more resistant to hurricane damage at a cost warning of the hurricane path, though a modest storm can of only a 1.8 to 3.7 percent increase in the total sales price develop into a hurricane in less than that time and the of the property. Often increased standards fail to pass at all storm path is often unpredictable. Most people believe it levels of government until a major disaster and huge losses would take them less than one day to evacuate, but stud- make the need obvious to everyone. Even then, the issue of ies show that because of traffic jams and related problems whether the state or counties are required to foot the cost most evacuations take up to thirty hours. With recent heavy of enforcing new regulations often thwarts new laws. When development in coastal areas, 80 percent of the 40 million adequate building standards are not enacted and enforced, people living in areas subject to hurricanes have never been the general public is eventually forced to pay for the un- involved in an evacuation. The large seasonal tourist popu- necessary level of damage. People’s federal and local taxes lations make matters even worse. Municipalities also view could be lower if it were not for such unnecessary costs. hurricane publicity as bad for tourism and property invest- In the 1980s, the state of Florida designated a coastal con- ment. Some people who have lived through one hurricane struction control line (CCCL), seaward of which habitable do not leave, believing that if they have done it before, they structures are permitted only with adherence to certain can do it again. Prospects for a calamity are genuine. standards of land use and building construction. The CCCL The costs of evacuations are also large. The usual estimate designates the zone that is subject to flooding, erosion, is that it costs roughly $1 million per coastal mile exclusive and related impacts during a 100-year storm. These stan- of any damages from the hurricane. Because forecasters dards are more rigorous than those of the National Flood refer to the statistical likelihood that a storm will strike a Insurance Program and standard building codes. Hurricane given length of the coast and there is significant uncertainty Opal on October 4, 1995, provided a Category 3 test of the in the direction of the storm track, many more people are system. None of the 576 major habitable structures built to warned to evacuate than those in the final path of the storm. CCCL standards and seaward of the CCCL suffered substan- This is an unfortunate but necessary cost for the safety of tial damage. Of the 1,366 preexisting structures in that zone, the coastal population. 768 (56 percent) were substantially damaged. On average, 640 kilometers (400 miles) of coastline is warned of hurricane landfall within twenty-four hours. Of that, 200 kilometers (125 miles) may actually be strongly af- Hurricane Prediction fected by the storm. Thus, some $275 million in costs were borne by people ultimately not in the storm’s path. Clearly, and Warnings more accurate forecasting could save significant costs. The 2004 hurricane season showed that, even with our Hurricane predictions include time of arrival, location, greatly improved prediction abilities, hurricanes still be- and magnitude of the event. The time of arrival is moder- have unpredictably. This was the first time four hurricanes ately predictable, but the specific location of landfall and came onshore in a single state since 1886 when Texas was the storm strength at landfall are poorly known more than the unfortunate victim. The first storm, Charley, approached a day or two in advance. We know that a hurricane’s en- the Gulf Coast of Florida as a Category 2 storm and was not ergy is drawn from the heat in tropical ocean water. But expected to do severe damage. Much to the surprise of fore- newly recognized large eddies of warm water 100 or more casters, Charley grew to a Category 4 storm in the few hours kilometers across can apparently spin off larger oceanic before it came ashore on August 13. Frances arrived on Sep- currents and boost the energy of hurricanes passing over tember 5 as a Category 2, Ivan 4( Figure 14-6) made landfall

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Hyndman 0495153214 Chapter 14.in41 41 3/9/06 7:58:57 AM Figure 14-65. Canada 4 Four major hurricanes decimated Florida in August and September 2004, striking many United States Charley areas more than once. Aug. 9 to 15 N Ivan weakens

Jeanne North Atlantic Ocean Sept. 13 to 29 Cuba Frances Africa Aug. 25 to Sept. 10

Central America

Ivan Sept. 2 to Sept. 18 South America NOAA data.

on September 15 as a Category 4, and then finally Jeanne Categories of Hurricane Alerts dealt the final blow as a Category 3, following virtually the same track through Florida as Frances. In less than a month Hurricane Watch “A hurricane is possible in the and a half, these storms wreaked havoc across Florida watch area within 36 hours. Stay tuned to NOAA weather 4( Figures 14-65). The level of damage inflicted on coastal radio or a local station for additional advisories.” This is communities by Ivan should leave no doubt that people the warning given during a hurricane watch. You should need to evacuate when warned 4( Figures 14-66 and 14-67). have prepared your property for high winds before this In some places, later storms hammered areas destroyed stage, but if you have not, then you should do the following from the earlier storms as they were in the middle of repairs. immediately: USGS. 4 Figure 14-66. Many buildings in Orange Beach, Alabama, were completely destroyed by Hurricane Ivan on September 15, 2004. Note that the front half and right side of the large five- story resort on the left collapsed into rubble. Anyone planning to ride out the storm there could not have survived. The one well-built house, near the center of both photos, survived, but the houses around it did not. Use red arrows to compare buildings.

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Hyndman 0495153214 Chapter 14.in42 42 3/9/06 7:58:58 AM USGS photos. 4 Figure 14-67. Many beachfront homes in Orange Beach, Alabama, vanished in Hurricane Ivan in September, 2004. Even some behind the first row of buildings were destroyed; note the ground-level house to the right and behind the larger building on the right.

■ Fill your vehicle’s gas tank. Gas station attendants may Hurricane Warning “A hurricane is expected in the evacuate before you do. warning area within twenty-four hours. If advised to evacu- ■ Because winds cause the greatest damage, bring in any- ate, do so immediately.” This message is typically given thing that can become a damaging projectile in a high during a hurricane warning. The has a wind. Remove damaged or weak limbs on trees, along great deal of experience in planning for such warnings and with extra branches to permit the wind to blow through. suggests the following: Remove outside antennas. Board up windows securely ■ Plan to leave if you live on the coast, on an offshore and reinforce garage doors. island, in a floodplain, or in a mobile home. Tell a rela- ■ Move a boat to a safe place, preferably above storm tive outside the storm area where you are going. surge height. Secure a boat to its trailer with a rope or ■ If you evacuate, take important items: identification, chain. Anchor the trailer to the ground or house with important papers (e.g., passports, insurance papers), secure tiedowns. prescription medicines, blankets, flashlights, battery ■ Stock up on any prescription medications, food, and radio and extra batteries, first aid kit, baby food and water—a one-week supply at home in addition to a diapers, and any other items for a week or two in a three-day supply for evacuation. shelter. Lock your house. ■ Store as much clean drinking water as possible in plas- ■ Listen to the radio for updates. Use telephones only for tic bottles, sinks, bathtubs. Public water supplies and emergency calls. wells often become contaminated, and electric pumps ■ Do not drive through floodwaters. The road may be do not work without electricity. A small generator can washed out, and 2 feet of water can carry away most be helpful, but stores sell out quickly when such crises cars. Stay away from downed or dangling power lines; arise. report them to authorities. ■ Turn the refrigerator to the coldest setting. The power may be out for a long time. ■ If trapped at home before you can safely evacuate, be aware that flying debris can be deadly. Stay in a small, ■ Turn off appliances. The power surge while electricity strong, interior room without windows; stay away from is restored may damage them. windows even if they are shuttered. Hurricanes can ■ Turn off propane tanks and anchor them securely. spawn tornadoes. Close and brace exterior and interior Unplug small appliances; they may be damaged by a doors. Use flashlights for emergency light; candles and power surge. kerosene lamps cause many fires. ■ Evacuate when authorities say to do so 4( Figures 14-54, ■ If the eye of the hurricane passes over you, the storm is 14-55). not over; high winds will soon begin blowing from the ■ Close and secure storm shutters or board up windows opposite direction, often destroying trees and buildings with plywood. that were damaged in the first winds.

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Hyndman 0495153214 Chapter 14.in43 43 3/9/06 7:58:59 AM As recently as during Hurricane Floyd in 1999, the following did, in fact, appear successful in that maximum wind ve- became apparent: locities decreased by 15 to 30 percent for some hours af- ter the seeding. However, it was never really demonstrated 1. People need to evacuate as soon as ordered rather that the seeding decreased the wind velocity; the costs of than waiting to the last minute. obtaining and maintaining suitable aircraft for monitoring 2. The huge increase in population along the coast in the effects at high altitude were expensive. Further experi- recent years has outgrown such infrastructure as high- ments were thwarted by the lack of hurricanes with well- ways. The roads are not able to cope with evacuating developed eyes. populations. 3. Changing freeways to single direction traffic away from the coast merely moves the bottleneck inland. It also creates severe safety problems at offramps where people traveling opposite from the normal direction of A More Damaging Hurricane traffic try to get off to find lodging. than Any in Historic Time? 4. Lodging is completely inadequate to cope with the whole coastal population. Hurricane damage is amplified by the following cir- 5. The latest approach is to move people 32 kilometers cumstances: from the coast, beyond the limit of surge, to temporary ■ heavy or prolonged rain; protection, not hundreds of kilometers from the coast ■ surge height (see Sidebar 14-2) amplified by funnel- as was done in the past. ing into a bay, wedging into shallow water of a gently sloping continental shelf, high northeast-quadrant winds pushing water up against the coast, and coinciding with high tide as in the Galveston hurricane of 1900; Hurricane Modification? ■ higher winds; ■ If we could somehow reduce the energy of a hurricane higher storm waves pushed by higher winds (larger or dissipate it over a broad area, we could presumably re- radius storm, longer fetch); duce the hazard. Various schemes have been suggested, ■ warm eddies in the Gulf Stream adding energy to the but none have proved feasible. For more than half a cen- storm; tury, one suggestion has been to blow them apart using a ■ storm stalled by other weather systems such as nearby nuclear bomb. Aside from the obvious problem of radio- stationary high pressure systems; and active contamination, a moderate-size hurricane releases ■ the energy equivalent of 400 twenty-megaton hydrogen following shortly after another hurricane when the bombs in one day. Clearly, that is not a viable possibility. ground is already saturated and when barrier islands Another suggestion is to spread a chemical film over the and their beaches and dunes have been already surface of the ocean under the hurricane to dramatically re- stripped of sand (Hurricane Floyd in mid-September duce evaporation from the sea surface. That would be simi- 1999 came only two weeks after Hurricane Dennis lar to having the hurricane weaken as it passes over land or had saturated the ground and stripped sand from the over cold water. Unfortunately, waves would immediately beaches). break up the chemical film and destroy its effectiveness. A What would it take to have a still more devastating event? third scheme is to spread minute particles of black carbon The highest category hurricanes are extremely damaging particles into the boundary layer around the hurricane’s because of their high winds and because their low core cloud shield. The black would absorb solar radiation, warm atmospheric pressure leads to high surge heights. Lower- the boundary layer, increase convection in the outer part category hurricanes, however, often have a larger diam- of the hurricane and in turn reduce the velocity of the hur- eter, leading to longer fetch with higher storm waves and ricane’s strongest winds. Dispersal of the carbon particles broader areas affected. A one-two punch could be provided would be a technological challenge, the cost would be high, by two or more large, back-to-back hurricanes. The effect and the continent would lose precipitation that it normally could be amplified by hurricanes stalled by nearby station- receives. ary high pressure systems, by coinciding with an especially One experiment at hurricane modification was actu- high tide, and by additional energy from huge warm-water ally attempted in the 1960s and ’70s. The idea was to seed cells in the Gulf Stream sweeping up the East Coast of the clouds in the outer edge of the eye wall with silver iodide. United States. If several of these influences were to overlap This would cause water droplets to freeze, releasing heat in time (see Figure 1-4, page 5), and this storm were to hit in the process. This would widen the radius of the eye and a major city such as Miami or New Orleans, we might have cause slowing of the maximum winds. The experiments truly incredible damages.

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Hyndman 0495153214 Chapter 14.in44 44 3/9/06 7:59:00 AM Key Points the northeast forward quadrant of the hurricane because of wind directions. Review p. 19; Fig- ✓ Hurricanes and other major storms cause severe ures 14-24 and 14-25. coastal damage. Beaches and dunes are eroded, ✓ Damages from the hurricane depend on its path and buildings are severely damaged by wind, compared with shore orientation, presence of bays, waves, and flooding. Damage is most severe forward speed of the hurricane, the height of dunes where local zoning does not require raising build- and coastal vegetation. Review pp. 19–20. ings on posts and storm-resistant construction. ✓ The nature and quality of building construction Review pp. 1-5. has a major effect on damages. Floors, walls, and ✓ Hurricanes, typhoons, and cyclones are all major roofs need to be well anchored to one another, storms that circulate counterclockwise with winds and buildings should be well attached to deeply from 120 to more than 260 kilometers per hour. anchored stilts. Damages from wind are greatest. Review pp. 5–7 and 10. Review pp. 20 –21. ✓ The strongest hurricanes, Category 5 on the Saffir- ✓ High waves have much more energy and erode Simpson Hurricane Scale, have the lowest atmo- the beach lower and to a flatter profile, as well spheric pressure of less than 920 millibars and the as erode dunes, especially if the waves are not highest wind speeds of more than 249 kilometers slowed by shallow water offshore. Review per hour. Review pp. 5–7; Table 14-1. pp. 24 –25; Figures 14-36 to 14-38. ✓ Hurricanes that affect the southeastern United ✓ Wind damages include blowing in windows, States form as atmospheric lows over warm doors, and walls; lifting off roofs; blowing down subtropical water. The central core or eye of the trees and power lines; and flying debris.Review hurricane is 20 to 50 kilometers in diameter, out pp. 25–28; Figures 14-43 to 14-48. of a total 160 to 800 kilometers. Clear, calm air in the low pressure eye is surrounded by the high- ✓ Rain and flooding from hurricanes can be greater est winds and stormy skies. Review pp. 7 and with large-diameter, slower-moving storms. Re- 10 –11; Figures 14-6, 14-11, and 14-12. view pp. 28–31. ✓ Hurricanes rotate counterclockwise, as in any ✓ Many people think they can evacuate quickly low pressure area, but track clockwise, as with and leave too late. Storm surges and downed ocean currents. They grow off the west coast of trees and power lines often close roads. In addi- Africa, then move westward with the trade winds. tion to buildings and bridges, damages include Most hurricanes are from August through October the deaths of farm animals, agricultural damage, because it takes until late summer to warm the contaminated drinking water, and landslides. ocean sufficiently. They strengthen over warmer Review p. 32. water and weaken over cool water or land. Re- ✓ Thousands of people in poor mountainous coun- view pp. 10 –11; compare Figures 14-14 tries such as those in Central America die in to 14-16. floods and landslides triggered by hurricanes ✓ The greatest impacts from hurricanes are felt from because they live in poorly constructed houses North Carolina to Florida to Texas. Annual dam- on floodplains and unstable steep slopes.Re- ages run from hundreds of millions to billions of view pp. 34 – 40. dollars. Review p. 10; Figure 14-17. ✓ Thousands of people living on low-lying deltas ✓ Nor’easters and other extratropical cyclones are of major rivers die in floods and storm surges similar to hurricanes except that they form in Review pp. 34 and 39– 40. winter, lack a distinct eye, are not circular, and ✓ The National Flood Insurance Program requires spread out over a large area. Like hurricanes, they that buildings in low-elevation coastal areas be are characterized by high winds, waves, and storm landward of mean high tide and raised above surges. Review pp. 12–14. heights that could be impacted by 100-year floods, ✓ Storm surges, as much as 7.3 meters high and including those imposed by storm surges. Restric- 160 kilometers wide, result from a combination tions are similar to those for streams. Review of low atmospheric pressure that permits the rise pp. 35 and 41. of sea level and prolonged winds pushing the sea ✓ Hurricane predictions and warnings include the into a broad mound. Review pp. 18–21; Side- time of arrival, location, and magnitude of the bars 14-1 and 14-2. event. The National Hurricane Warning Center ✓ Surge hazards include significant rise of sea level tries to give twelve hours of warning, but evacu- and waves on top of the higher sea level. The ations can take as many as thirty hours. Review surge and associated winds are concentrated in pp. 41– 44.

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Hyndman 0495153214 Chapter 14.in45 45 3/9/06 7:59:00 AM Important Words and Concepts 8. What effects do the higher waves of hurricanes have on the coast? Terms 9. If the forward speed of a hurricane is greater, what cyclone, p. 1 hurricane warning, p. 41 negative effect does that have? What positive effect , hurricane watch, p. 42 does it have? p. 12 Nor’easter, p. 12 10. Which part of a hurricane does the greatest damage? eye, p. 7 storm surge, p. 13 (In other words, if the eye of a west-moving hurricane fetch, p. 13 typhoon, p. 1 were to go right over Charleston, South Carolina, where hurricane, p. 1 would the greatest damage be?) 11. What is the difference in damage if a hurricane closely Questions for Review follows another hurricane—for example, by a week? 1. What causes a tropical cyclone or hurricane? Where Why? does a hurricane get all of its energy? 12. Why is there more coastal damage if the sand dunes 2. Where do hurricanes that strike North America origi- are lower? nate? Why there? Why do they track toward North 13. What shape of roof is most susceptible to being lifted America? off by a hurricane? Why? 3. Why are coastal populations so vulnerable to exces- 14. Why is it so important to cover windows and doors sive damages (other than the fact that they live on the with plywood or shutters? coast)? 15. Why do developers, builders, local governments, and 4. Where in a hurricane is the atmospheric pressure low- many members of the public oppose higher standards est and approximately how low might that be? for stronger houses? 5. When is hurricane season (which months)? Why then? 6. What two main factors cause increased height of a Further Reading storm surge? Assess your understanding of this chapter’s topics with additional 7. What effects does the wind have on buildings during a quizzing and conceptual-based problems at: hurricane? http://earthscience.brookscole.com/hyndman.

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Hyndman 0495153214 Chapter 14.in46 46 3/9/06 7:59:00 AM Mike Buytas photo, U.S. Air Force. Flooding during Katrina covered many homes to their rooftops with contaminated water coated with an oil slick. Some homes floated off their foundations to lodge against other homes.

2004 set a record for devastating hurricanes that impacted the southeastern United States. Four major hurricanes, in August and then Frances, Ivan, and Jeanne in September, laid waste to Florida and adjacent states, each causing between about $7 billion and $14 billion in dam- Katrina ages. Although forecasters have noted that the number of strong hurricanes has been increasing in recent years, no A Case Study of the one foresaw that 2004 was a warm-up for the most destruc- tive hurricane season in history in 2005 with the likes of Costliest Disaster Katrina, Rita, and Wilma. Hurricane Katrina in late August set a new standard for the level of damage and for questions in U.S. History raised about the potential effects of hurricane flood surge, of coastal development patterns, and the need for far better disaster preparedness. In this chapter we examine Hurricane Katrina’s destruc- tion of southeastern Louisiana and New Orleans as well as coastal Mississippi and Alabama, the background that led up to it, the response to this unprecedented event, and its aftermath. Changes clearly need to be made to avoid such a terrible toll on people and property in the future.

Hyndman 0495153214 Chapter 19.in47 47 3/9/06 8:16:55 AM Hurricanes Up Close Hurricane Katrina

The Setting: New Orleans, level of the Mississippi River; the original floodplain marsh was drained beginning more than a century ago to allow for Pre-Hurricane Katrina expansion of the city. Following a disastrous Mississippi River New Orleans, a city of half a million people, is virtually at sea flood in 1927, the levees were built higher and strengthened. level, just upstream from the mouth of the Mississippi River Additional levees were constructed in the 1940s and 1950s, 4 ( Figure 19-1). Although the original settlements were above and shipping canal walls were added in the 1960s. Unfortu- sea level on the natural levees of the river, most of the modern nately the city on the floodplain continues to slowly sink as city lies below sea level, leaving it vulnerable to catastrophic groundwater is withdrawn for municipal and industrial uses, floods. The city now lies behind engineered levees that are as and buildings continue to compress the underlying peat. much as 7 meters above sea level and most people living be- A total of 148 giant pumps remove water from the spongy hind those levees felt comfortably protected. sediments. Now much of the city lies 3 meters below Lake Some of those levees along Lake Pontchartrain were built Pontchartrain’s normal level and 4 meters below the Missis- years ago by local governments or private groups and were sippi River—not a good place for hundreds of thousands of not well engineered. The newer and less affluent districts that people to live. were built off the natural levees were several meters below the Since the city sits in a bowl below sea level, emergency planners have worried for decades about a direct hit from 4 FIGURE 19-1. Southeastern Louisiana, with Lake Pontchar- a major hurricane. The flood control system designed for a train, the Mississippi River, New Orleans, and the Gulf of Mexico. Category 3 hurricane might not be adequate for such a storm, let alone a Category 4 or 5. The city’s only ma- jor evacuation routes are Interstate 10 and sec- ondary roads to the west near the Mississippi River, and Interstate 10 to the northeast across a low-lying 10-kilometer bridge near the eastern Louisiana Mississippi end of Lake Pontchartrain, a giant tidal lagoon. An equally low-lying 38-kilometer causeway ex- tends north across the middle of the lake. Emergency managers have long been con- cerned about two events that could lead to flooding of this open bowl and a catastrophe for New Orleans: Lake Bay St. Louis Pontchartrain 1. A huge flood on the lower Mississippi River could overtop its big levees, which were built by the U.S. Army Corps of Engineers Lake R ppi iv New for 100-year flood levels and don’t often ssissi e Bourne Mi r Orleans fail. As we noted in Chapters 11 and 12 on streams and floods, 100-year flood events can come anytime. Compounding matters, with each successive flood the channel of Mississippi River the Mississippi River rises due to deposition of sediments from upstream. Major floods also get progressively larger over time be- cause of continued urbanization and build- ing of levees upstream in the drainage basin. A levee breach upstream of New Orleans could flood low ground beyond the levees on the north, which would raise Lake Pon- tchartrain at the northern edge of the city. If the population did not evacuate because

2S NASA shuttle radar image. they thought the levees would protect them, 1S N 48 48

Hyndman 0495153214 Chapter 19.in48 48 3/9/06 8:17:01 AM hundreds of thousands of people could be endangered Either scenario could leave about 80 percent of the city un- after their escape roads were submerged. der several meters of water. Single-story houses would be 2. A strong hurricane striking New Orleans directly or graz- submerged up to their roofs or even higher (as seen in the ing it on the east could lift a storm surge from the Gulf photo on page 451). Surrounded by water for days, where of Mexico high enough to swamp the near–sea level delta would people find food or potable water? Municipal, petro- areas south and east of the city, then overtop the levees chemical, and industrial wastes would quickly contaminate to flood the city. Predictions included a surge of 4to the water surrounding them. 5 meters into Lake Pontchartrain and 2-meter waves above Although warnings have come with some regularity from that, which could completely swamp the city in an hour. various knowledgeable individuals and organizations, no People who either were unable or refused to evacuate in large-scale improvements have been implemented. The Fed- anticipation of the approaching storm would be in jeop- eral Emergency Management Agency (FEMA) conducted ardy. With high winds downing trees and power lines and a simulated hurricane response exercise for New Orleans in rapidly rising water covering roads, what would they do? 2004 but remained poorly prepared. Most of those predic- Where would they go? tions would prove eerily accurate for Katrina.

Hurricane Katrina Unfolding Events A chronology of the events (Table 19.1) leading to the Katrina crossed southern Florida from the east, just north of Katrina catastrophe highlights the problems and exposes Miami, on the evening of August 25th as a weak Category 1 major gaps in preparedness for such an event. hurricane. Its sustained winds of 129 kilometers per hour did considerable damage to coastal homes and other buildings, and the heavy surf eroded beaches. Since twice the normal Planning and Evacuation amount of rain had fallen during July, the 15 to 38 centi- meters of rain from Katrina caused widespread flooding. Six As Hurricane Katrina bore down on the Louisiana and Mis- people died; more than a million people lost power. sissippi coasts, most people complied with evacuation or- After crossing Florida, the storm strengthened as it picked ders but thousands of residents in the very poor, predomi- up energy from the 32°C (90°F) waters of the Gulf of Mexico. nantly African-American, eastern parts of New Orleans did The National Hurricane Center in Miami expected the storm not. Most of these people had no cars or other means of to curve northward to impact the Florida panhandle, but transportation and no money for travel even if transporta- it turned less than expected and headed directly for New tion was available. Many of them felt that New Orleans and Orleans 4( Figure 19-2). the surrounding communities, especially areas not right on

Louisiana Miss. Alabama Georgia

Texas New Orleans

Florida

4 FIGURE 19-2. On August 28 at 7 p.m. GULF OF MEXICO Katrina bears down on New Orleans as a Category 5 hurricane with a well-defined

Modified from NOAA image. eyewall. Its track is shown as a orange line. 2S 1S N 49

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Hyndman 0495153214 Chapter 19.in49 49 3/9/06 8:17:02 AM Table 19.1 Saturday, Aug. 27, The director of the National Hurricane Center called the mayor of New Orleans and President Bush to express late evening extreme concern about the approaching hurricane, referring to it as a potentially catastrophic storm. Sunday, Aug. 28, Hospitals discharged as many patients as possible. The mayor called a mandatory evacuation of New Orleans, morning and traffic was rerouted to permit both sides of freeways to carry outbound traffic. Officials in outlying areas and coastal Mississippi and Alabama followed suit. 12 p.m. The Weather Service in New Orleans predicted catastrophic damage to the city. Buses were dispatched to help shuttle evacuees to shelter in the Superdome, but bureaucratic problems restricted the use of school buses and left thousands of people stranded. Monday, Aug. 29, Landfall: Katrina weakened from a Category 5 hurricane to a Category 3 at landfall on the coast just east of New Orleans; winds pushed a huge wave of water westward into the eastern suburbs of the city. Katrina hammered 7 a.m. coastal Mississippi with high winds and a huge storm surge. Windows of high-rise buildings, hotels, and hospitals blew out. Interstate 10 across the eastern end of Lake Pontchartrain collapsed. A floodwall on the Industrial Canal breached as the storm surge pushed up the dredged Mississippi River Gulf Outlet to the east. Water in parts of the city rose 2 meters within a few minutes, filling houses and floating cars. 2 p.m. Electricity was out; three of the big pumps that keep the city drained failed; and a huge water main broke, contaminating the city’s drinking water. Hospitals ran out of fuel for emergency generators. Bodies were seen floating in the floodwater. 11 p.m. The water level in some areas was 6 meters deep. A tanker that ran aground leaked oil; natural gas leaks were reported in many places. Telephone and cell phone failures hindered communications. Tuesday, Aug. 30, A wide breach in the eastern wall of the 17th Street Canal flooded much of the northern part of New Orleans, 1:30 a.m. and the London Avenue Canal also breached in two places. At 2:30 p.m. National Guard helicopters began placing giant 3200-kilogram sandbags in the 17th Street Canal breach in an attempt to seal it. Wednesday, Aug. 31 Water surrounded the Superdome. The governor ordered the evacuation of the remaining people in New & Thursday, Sept. 1 Orleans, including those in the Superdome and the Convention Center; they were to move to the Astrodome and elsewhere in Houston. Most of the city was under water, trapping people on roofs and in attics. Friday, Sept. 2 The 17th Street Canal was dammed with steel pilings on the lake side of the breach, controlling further flooding. Fires were reported, some of which were cases of arson. Mold grew in most buildings. Sunday, Sept. 4 The Corps of Engineers finished closing the breach in the 17th Street Canal. The next day, electric power began returning to downtown buildings. Tuesday, Sept. 6 The Port of New Orleans began receiving relief but not commercial ships. Thursday, Sept. 8 Domestic water was turned on in some neighborhoods on high ground but was still unsafe to drink. The number of people in shelters peaked at 270,000; 400,000 others were living with relatives or friends, or in hotels. Saturday, Sept. 10 About 60 percent of the city remained under water. Freight activity on the Mississippi River began to return. Monday, Sept. 12 By this time, five hospitals in the city and the main wastewater treatment plant had reopened. Military aircraft began widespread spraying of pesticides to kill mosquitoes in order to prevent disease outbreaks. Saturday, Oct. 1 The less-damaged French Quarter and uptown areas reopened to residents. Wednesday, Oct. 5 The Corps of Engineers continued to rebuild breached levees and to pump water from the Lower Ninth Ward. The door-to-door search for victims ended.

the coast, had survived hurricanes before and would do tion efforts—the buses were not air-conditioned and might so again. Others felt that the brunt of the storm would miss cause heatstroke. FEMA said they were providing suitable them, just as Hurricane Ivan spared New Orleans when it buses but failed to tell the governor that they would come roared into the Gulf Coast of Alabama and adjacent Florida from out of state and would not be immediately available. in September 2004, wreaking havoc there. However, many Many residents who sought food, water, and shelter of these people perhaps did not recall some of the other found their own way to the Louisiana Superdome stadium storms that had struck the area. In 1965 , a and to the New Orleans Convention Center 4( Figure 19-3); Category 3 storm, left almost half of New Orleans under wa- others were brought there by rescuers. By the time the storm ter, almost 7 meters deep in some places. Hurricane Andrew, arrived the next morning, 9000 residents and 550 National in August 1992, passed just west of New Orleans. In 1969 Hur- Guard troops were housed in the giant Superdome. FEMA ricane Camille, a Category 5 storm at landfall, caused major did arrange for eighteen medical disaster teams, as well damage in Mississippi and Louisiana. Although pre-Katrina as search-and-rescue teams, medical supplies, and equip- planning predicted that at least 100,000 residents would not ment, but relief for most refugees did not come until four have transportation, few buses were sent to shuttle them days after the storm. out of the area. Hundreds of school buses were left unused Ten thousand National Guardsmen were finally ordered 2S because the city could not find drivers and because FEMA to the area days after the storm, to help in rescue, public 1S apparently asked that school buses not be used in evacua- safety, and cleanup efforts. They brought in water, ice, tarps, N 50 50

Hyndman 0495153214 Chapter 19.in50 50 3/9/06 8:17:03 AM and millions of ready-to-eat meals, but it was not enough. The hurricane-force winds blew off part of the roof lining of the Superdome, causing it to leak. The power went out in the stadium; the air conditioning failed, leaving the air thoroughly unpleasant and allowing the floors to become slippery with condensation; water pressure dwindled, so toilets plugged up in the bathrooms. People received water and two meals a day. Some individuals (particularly the el- derly and very young) were sick or went without their pre- scription medicine; some people suffered heatstroke and several died. Ultimately more than 20,000 people ended up in the Superdome until 1 meter of water rose around it 4( Figure 19-4). Thousands also took refuge in the Conven- tion Center until it too became unsanitary and unsafe.

Approach and Landfall The National Weather Service predicted that the hurricane would cause catastrophic damage and “human suffering in-

Marty Bahamonde photo, FEMA. credible by modern standards,” and they were absolutely 4 FIGURE 19-3. Before the hurricane made landfall, residents correct. In the Gulf of Mexico, Katrina strengthened to a lined up to get into the shelter of the Louisiana Superdome. Category 5 hurricane with a central pressure of 902 milli- bars and sustained winds of 280 kilometers per hour shortly before reaching the coast just east of New Orleans. It weak- ened to a Category 4 at the mouth of the Mississippi River and to a Category 3 in shallow waters before landfall on coastal Mississippi on Monday, August 29, at 7 a.m., where it laid waste to nearly everything within hundreds of meters of

I-10

US-90 U.S. Navy photo by Jeremy Grisham. 4 FIGURE 19-4. By August 31, the Superdome was surrounded by water and sections of 2S its roof covering had blown off. View is northeast; the Mississippi River is to the right. 1S N 51

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Hyndman 0495153214 Chapter 19.in51 51 3/9/06 8:17:11 AM the beach. As the storm moved north through eastern Mis- sissippi, it weakened further.

The Wind, Storm Surge, and Flood When Katrina veered slightly east after landfall and the winds subsided, New Orleans residents and officials thought they had escaped the brunt of the storm and its dreaded surge. However, with its counterclockwise rotation and landfall near the Louisiana–Mississippi line, the high near-shore winds on Katrina’s north flank were directed westward toward New Orleans. Winds that do much of the damage in most hurricanes, especially on open coastlines such as those of Mississippi and Alabama, caused significant dam- age in New Orleans as well. Throughout New Orleans, trees and power lines fell; the winds blew out windows, includ- ing those in hospitals, office buildings, and hotels 4( Fig- ure 19-5). Tornadoes, which accompanied this hurricane K. Niemi photo, U.S. Coast Guard. 4 FIGURE 19-7. Interstate 10 interchange in northwestern New Orleans lies under water, along with nearby homes. Part of the roadway lost its decking (lower center of photo).

as with others, did some of the most severe wind damage. Beds were seen flying out of some high windows. In some areas the combination of high winds and flood- waters left little standing 4( Figure 19-6). Much of the city was under water, so rescuers had to use small boats and Liz Roll photo, FEMA. helicopters to reach people 4( Figure 19-7). 4 FIGURE 19-5. Downed power lines that were still live posed a Most of the damage to New Orleans was caused by the severe hazard to people. storm surge that raised the water level in Lake Pontchartrain

4 FIGURE 19-6. Large parts of the Lower 2S Ninth Ward, in the eastern part of the city, 1S were almost completely destroyed. Note that

N Win Henderson photo, FEMA. some houses floated and moved. 52 52

Hyndman 0495153214 Chapter 19.in52 52 3/9/06 8:17:12 AM and the canals that typically drain water from the city into the lake 4( Figure 19-8). The surge came through the Mis- sissippi River Gulf Outlet (MRGO) and the topographically low tidal lagoons of Lake Borgne and Lake Pontchartrain at the eastern and northern edges of New Orleans. Pushed by fierce winds, the surge moved west through the MRGO and Lake Borgne. It raised the level of Lake Pontchartrain, and high waves topped levees in many places 4( Figure 19-9). Even on a normal day, that lake lies meters above the lower parts of New Orleans. In both cases the eastern suburbs of New Orleans were rapidly inundated, with water rising as much as 30 centimeters per minute. Residents described a river with 2-meter waves rushing down streets. Several large canals extend southward from Lake Pon- tchartrain to the city interior; giant pumps that pull water Les Harder photo. from the city drain it into the lake via the canals 4( Fig- 4 FIGURE 19-9. Plaquemines Parish homes, floated from left to ures 19-8a and 19-10). The Industrial Canal in the eastern right by the surge, were dumped onto the Mississippi River levee, part of the city provides a shipping channel between the downstream from New Orleans. lake and the Mississippi River. This connects to the MRGO canal, which provides a relatively straight 11.3 meter-draft shipping path between the eastern portion of the city and

4 FIGURE 19-8. (a) This map of New Orleans for Lake Pontchartrain Flood Depth September 2, 2005, shows (Meters) that flood depths were < 0.3 shallow on the natural levee B areas at the north bank of the Mississippi River, 1 Mississippi River - increasing to 3 or 3.5 meters over much of the city. The Gulf Outlet abrupt end of flooding on the west is at the 17th 2 Street Canal with levees that breached to the east A but held to the west. (b) Minimal Flooding This cross section is drawn 3 south to north, from the r e Mississippi River to Lake iv Minimal Flooding >3.5 i R pp Pontchartrain, through the M issi ssi French Quarter. Except for Pumping station the natural levee of the river, Main water plant the whole city lies below the average annual high-water Breach direction level of the river and most of it lies below the normal level (a) of Lake Pontchartrain.

10 8 A B 6 4 Mississippi River Lake 2 New Orleans Ponchartrain 0 2 4 6 2S 8

Elevation in meters above sea level 1S (b) Modified from USGS and U.S. Army Corps of Engineers. 10 N 53

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Hyndman 0495153214 Chapter 19.in53 53 3/9/06 8:17:28 AM withstand a Category 3 hurricane. The Corps of Engineers conceded that some levees had settled lower than that and needed to be raised. Experts noted that the design was not up to modern standards and may have left the levees weaker than expected. Water surging over the walls likely undermined their bases. Studies showed that soil used to build some of the levees included layers of sand and shell fragments that would erode easily.

The Pumps Fail Since most of New Orleans lies below sea level, giant pumps keep the city dry by lifting water into Lake Pontchartrain. With most of the city under several meters of water, the Plaquemines Parish photo. pumps failed, either for lack of electricity or by overheating 4 FIGURE 19-10. Levee breach at levee transition (steel (Figure 19-10). If, as happened in this case, a storm surge sheet wall versus reinforced concrete wall) near Hayes Pump raises the adjacent Gulf of Mexico and Lake Pontchartrain, Station. there is no place for water in the city to flow. Electricity soon failed throughout New Orleans and east earth levee topped by concrete wall canal along the coast through Mississippi and Alabama to the Florida panhandle. Because of power failures, destruction of base stations, and breaks in lines, telephones and cell faile d phones wouldn’t work. The resulting lack of communica- tion greatly hampered rescue efforts. Broadcasts from re- porters in nearby cities and communication over the Inter- net became important. Ten major hospitals were forced onto backup power. The water came in so fast that within minutes it was over people’s knees, forcing them up to second floors and attics or onto roofs. Some of those who retreated into attics had the foresight to take along an axe or a saw so they could break through the roof if the water continued to rise. They

Jocelyn Augustino, FEMA. waited there, sometimes for days, hoping for a quick res- 4 FIGURE 19-11. This neighborhood flooded when the canal cue, but had no means to contact authorities or rescuers. levee failed. The escape hole on the roof in the lower right was Searchers rescued at least 1500 people from rooftops and made by a resident trapped in the attic, in order to escape. heard others beating on attic roofs from inside. In case peo- ple were trapped in homes and attics, rescuers did house- the Gulf. All of the canals in the city stand meters above to-house searches. They found a few bodies, but fortunately residential areas and are separated from them by earthen not many. More bodies continued to be found three months levees capped by concrete walls. later 4( Figures 19-12 and 19–13). Twelve major breaches through these levees inun- Engineers expected that once the drainage pumps were dated New Orleans during and shortly after hurricane repaired, cleaned, and provided with power, it would take landfall, beginning about 18 hours after landfall 4( Fig- until mid-October to pump the water from the city. Unfortu- ure 19-8a). The levees generally consist of a ridge of dirt nately that water was fouled with a wide range of substances and rock topped by a concrete and steel floodwall that is that will create other environmental problems in Lake Pon- 30 centimeters thick and 5 meters tall. Two long sections of tchartrain. Engineers dammed the 17th Street Canal with floodwall failed during the storm, flooding homes that had steel sheet pilings 15 meters long to stop the flow of more been built just behind the levee and floodwall, where peo- water from Lake Pontchartrain through the breach into the ple felt protected from the water high above them 4( Fig- city 4( Figure 19-14). It took two weeks to fill the breaches, ure 19-11). The water poured directly into the basin occu- using helicopters to drop giant sandbags 4( Figure 19-15). pied by the city, drowning it in places with 4 meters of wa- It was also discovered that the type of drainage pumps for ter. Only the homes that were on the high-standing natural the city are no longer manufactured and replacement parts levee along the Mississippi River were largely spared. were not on hand, so damaged parts had to be rebuilt; this Levees along the north-south Industrial Canal (which severely set back the schedule for draining the city. An al- 2S carries much of the shipping between the Mississippi River ternate plan was to deliberately breach some lower levees 1S and Lake Pontchartrain), the 17th Street Canal, and the to let water drain back out and to use smaller replacement N MRGO were supposed to be over 5 meters high, enough to pumps that were available 4( Figures 19-16 and 19–17). 54 54

Hyndman 0495153214 Chapter 19.in54 54 3/9/06 8:17:31 AM Jocelyn Augustino photo, FEMA. Les Harder photo. 4 FIGURE 19-12. A rescue boat searches for hurricane survivors. 4 FIGURE 19-13. Three people died in this Ninth Ward home Many waited for rescue on rooftops. during the hurricane. Many waited for rescue on rooftops. 4 FIGURE 19-14. The 17th Street Canal crosses much of New Orleans south from Lake Pontchartrain in the foreground. The breach and flooded homes are visible on the far side of the canal above the bridge. The Corps of Engineers are driving pilings at the bridge to block water flowing down the canal from the lake while they also drop giant sandbags into the breach. U.S. Army Corps of Engineers photo.

4 FIGURE 19-15. The Corps of Engineers dropped giant sandbags in the breach in the 17th Street Canal in an attempt to stop further flooding of homes in the foreground.

2S 1S

Bob McMillan photo, FEMA. N 55

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Hyndman 0495153214 Chapter 19.in55 55 3/9/06 8:17:34 AM 4 FIGURE 19-16. New Orleans on Sep- N 10 km tember 6 before much water was pumped Lake Pontchartrain out. Areas under water are dark gray. Breaches and directions of flow are shown as blue arrows. 9th Ward

Mississippi River - Gulf Outlet

9th Ward

Mississippi River USGS/NASA satellite image. Bob McMillan photo, FEMA. U.S. military photo. 4 FIGURE 19-17. Smaller replacement pumps were used to help 4 FIGURE 19-18. In Chalmette, immediately downstream from pump water from New Orleans into Lake Pontchartrain after most New Orleans along the main Mississippi channel, a large spill of of the regular pumps failed. heavy oil spread through part of the town.

With any such storm, rains compound the problems. ple were fortunate to grab hold of larger pieces of trash or Katrina’s outer rain bands drenched New Orleans from Sun- drifting boats to stay afloat. Spills of thick oil from ruptured day morning just before landfall through Monday morning. tanks at six separate sites spread out in a gooey black sludge These rains combined with the storm surge to raise the Mis- 4( Figure 19-18). sissippi River by 4 meters. Flooding due to the rain also cre- Two weeks after Katrina’s arrival, five hospitals in the ated problems north of the coastal area as the storm moved city reopened, with limited service. However, there were inland and weakened. Although some of that flooding was far fewer patients after the mandatory evacuation; most significant, the problems it created were minor and short- hospitals had to lay off staff and reduce service. Many of lived compared to those caused by the storm surge. the patients had problems related to the polluted water, especially gastrointestinal illnesses, dehydration, and skin Contamination, Disease, and Mold infections. Aircraft sprayed pesticides to kill mosquitoes because of the danger of malaria, West Nile virus, and 2S The floodwaters were littered with pieces of houses, old St. Louis encephalitis. Even after September 16, weeks af- 1S tires, garbage cans, all manner of trash, coatings of oil and ter the storm had passed, some neighborhoods were still N gasoline from ruptured tanks, and even bodies. A few peo- flooded4 ( Figure 19-19); the water was contaminated with 56 56

Hyndman 0495153214 Chapter 19.in56 56 3/9/06 8:17:38 AM 4 FIGURE 19-19. Some neighborhoods were still flooded on September 16, weeks after the storm. Many already damaged homes floated off their foundations to collide with other homes. Fetid water was everywhere. Marvin Nauman photo, FEMA.

petrochemicals, household chemicals, and sewage. Tests also showed high levels of E. coli and lead. Mold grew in most buildings in contact with the warm, contaminated water. Many structures were so impacted that they will have to be bulldozed, despite being structurally sound. As the water receded and dried out, dark gray or black muck coated everything. In French Quarter buildings on the natural levee of the Mississippi, mold was growing a month later in rooms that were not flooded but were still without air-conditioning. Wallboard, insulation, rugs, bed- ding, and almost anything else that had gotten wet had to be discarded. With all of this contaminated debris, landfills were soon overwhelmed by the amount of incoming mate- rial. Even the bare studs of walls needed to be sanded, dis- infected with bleach, and then dried with fans. Any wood

frame structure standing in water for more than two or three Debbie Randolph photo. weeks had to be demolished because mold was impossible to remove from the wood. Most flooded homes were un- 4 FIGURE 19-20. Mold grew on the ceiling and walls of a home in the Lakeview District of New Orleans, submerged by the flood for der water for far longer periods of time so large parts of the about two weeks. city cannot be repaired 4( Figure 19-20). Not only is mold disgusting to see, its stench can irritate noses, lungs, and eyes, and lead to sore throats and coughs. The effects on people with allergies, asthma, or weak immune systems can and buses for evacuation—help that rarely materialized. be serious, since many kinds of molds spread by creating Promises seemed to come easily; help did not. On Septem- reproductive spores that drift through the air. ber 2, the New York Times and Washington Post reported that key federal politicians told the media that they didn’t Relief Came Slowly think that anyone had anticipated the breach of the levees. Apparently these politicians were not well informed. After Katrina, one of the most persistent questions was why Distribution of aid for disasters is logistically very com- FEMA, the National Guard, and other agencies took so long plex but giant cargo companies have become very efficient to provide relief. People waited for four days before anyone at distribution on a global scale. Since the Bam, Iran, earth- brought food, water, medical supplies, or vehicles for evacu- quake disaster of 2003, aid organizations such as the Inter- ation. Clearly emergency response to the catastrophe was a national Red Cross have used those techniques to distribute 2S dismal failure. Day after day, federal Homeland Security and aid quickly to victims of major disasters. FEMA presumably 1S FEMA officials promised National Guard troops, supplies, could have used such procedures. N 57

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Hyndman 0495153214 Chapter 19.in57 57 3/9/06 8:17:41 AM Deaths from the Hurricane on payments expired on October 26, 2005; insurance com- panies could then demand catch-up payment of premiums As of January 2006, confirmed deaths attributable to Hur- and drop policyholders who failed to pay. Making matters ricane Katrina totaled 1383. Of those, 1077 were in Loui- worse, the city’s tax base was dramatically decreased, leav- siana and 231 in Mississippi, far fewer than the 10,000 the ing it few resources with which to pay teachers, police, and mayor predicted for New Orleans soon after the flooding. other local employees. Thirty-nine percent of the people who died were more than Federal assistance will help. For neighborhoods de- 75 years old. As water rapidly rose, people were swept away stroyed by the hurricane, homeowners were to receive up by surge flow and drowned because they couldn’t swim, to $26,200 to pay for home repairs, temporary housing, and or they drowned in their houses after retreating to a higher auto replacement. Renters were to receive a lesser amount. floor or an attic and becoming trapped. When a huge wa- Eight major petroleum refineries in Katrina’s path were ter main broke, pollution leaked in, making water unsafe to shut down and almost all workers from offshore drilling plat- drink without boiling it first.E. coli contaminated the water forms were evacuated; twenty-nine of the platforms were supply. Five people reportedly died from illness caused by destroyed. When the giant anchors that held the platforms bacteria related to cholera. in place broke loose, they dragged, twisted, and sometimes Some patients in hospitals died when electricity neces- severed seafloor pipelines that carried the crude oil to the sary to power hospital equipment such as respirators and mainland. Disruptions shut down 95 percent of oil output dialysis machines failed and backup generators ran out of from the Gulf of Mexico, the biggest domestic source of pe- fuel; doctors and nurses squeezed hand-held ventilators for troleum. Pipelines inland from the area shut down for lack patients who couldn’t breathe on their own. At Memorial of power. Gasoline prices rose dramatically. Hospital, emergency generators were supposed to last six days but failed after two and a half, perhaps because of The Poor Have Additional Problems flooding. Patients were evacuated by boat and eventually by helicopter. There was no running water or ventilation; The predominantly poor people from the eastern part of seriously ill patients died in the 41°C (106°F) heat. Compli- the city, who were unable to evacuate before arrival of the cating the situation were neighborhood people who took storm, made up most of the flood survivors who crowded refuge in the hospital; soon everyone in the hospital was into the Superdome and the Convention Center during the down to one meal per day. Although many hospitals and storm (see Figure 19-3). Before Katrina, 23.2 percent of New nursing homes were evacuated before the storm, the avail- Orleans residents were below the poverty line and most of able equipment and manpower were insufficient to safely them lived in the eastern part of the city. Many lived from move some critically ill patients. Thirty-four nursing-home day to day, had no car or savings, and lived in rented homes patients died in the flood; the owners said they never re- or apartments. Others, often elderly, owned small homes ceived the mandatory evacuation order and that relocating purchased decades ago, but were equally poor. would have killed some of the frail patients. Some hospitals Less than half of New Orleans residents had flood insur- were so damaged by flooding and mold that they will never ance. Losing their homes also meant losing the last of their reopen. financial security. Despite a dangerous storm approaching, many residents had no means to leave the city and nowhere Financial Problems, Job Losses to go even if they could have left. Ten days after the storm, an estimated 10,000 people still refused to leave their homes Financial problems face most residents, small business own- in flooded and seriously contaminated areas. ers, and communities in the wake of Katrina. People who Looting was a problem. Television coverage showed im- need their salaries to make payments on mortgages and ages of people wading through water to break into stores to other loans cannot work because repairs are needed before make off with nonessential items such as electronic equip- their companies can reopen, if they reopen at all. Some ment, guns, drugs, alcohol, and anything else they could businesses that deal directly with the public no longer have carry. Others took primarily food and water. Since they were customers after the evacuation. Economists expect roughly taking items that belonged to someone else, even the theft 60,000 New Orleans–area businesses to fail. Employees lost of food and water would be considered looting; however, wages while businesses were closed during the hurricane; after days isolated from any help, many of these people when businesses fail, there are no jobs to go back to. Innu- must have been desperate, with nowhere else to turn. Many merable small businesses will probably never reopen. people apparently shared what they took with others who Without jobs, or jobs that pay equivalent wages, people were also in need. are likely to default on their loans. Immediately after the A major problem for many families and especially the hurricane, some banks permitted borrowers to delay pay- poor was separation of family members during evacuation ments but then demanded large payments to catch up. A and the storm. For example, a mother or father evacuated 2S moratorium that prevented insurance companies from with the children, but left behind an elderly parent who 1S dropping policyholders who lost their jobs and fell behind couldn’t be moved. In some cases, parents were separated N 58 58

Hyndman 0495153214 Chapter 19.in58 58 3/9/06 8:17:41 AM from their children during an evacuation or one parent left sippi shipping channel, the high winds, huge surge, and to help another relative, friend, or neighbor and was unable waves floated houses like matchboxes, dropping them on to return. Extended families were also further divided as roads or on other houses. Some buildings were moved with family members from coastal Mississippi and their relatives their concrete foundation slabs still attached. The surge in New Orleans were evacuated to different cities. lifted shrimp boats, pleasure boats, and some large com- mercial vessels and dumped them onto nearby levees and roads 4( Figures 19-21 and 19.22). Impacts Farther South and East: Thousands of homes, which were owned mainly by mid- The Hurricane Winds, Surge, and Waves dle-class families that worked for petroleum companies and their refineries, were either destroyed or rendered uninhab- News media focused on the storm damage in New Orleans itable because of mud swept in from the shallow bottoms because its flooding and destruction was so dramatic and of Lakes Pontchartrain and Borgne, and mold from long- catastrophic. However, elsewhere downriver and along the standing water. Nests of poisonous water moccasins and coast to the east, the storm’s effects were no less disastrous. other snakes swept in from the bayous added to the dangers. Southeast of New Orleans, near the main dredged Missis- Rotting animal carcasses were scattered near the roads.

4 FIGURE 19-21. A pair of 100-foot-long oil service vessels from the Mississippi River shipping channel ended up on Highway 23. U.S. Army Corps of Engineers photo.

4 FIGURE 19-22. Fishing boats lay in a tangled mess on Louisiana Highway 23, at the Mississippi River near Empire, Louisiana.

2S

Robert Kaufman photo, FEMA. 1S N 59

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Hyndman 0495153214 Chapter 19.in59 59 3/9/06 8:17:42 AM NOAA photo. 4 FIGURE 19-24. Dauphin Island, Alabama, lost most of the three rows of homes on its beach; all that remains are some of the posts on which they once stood. A portion of the sand that was eroded from the island was carried to the right into Mississippi Sound. John Fleck photo, FEMA. 4 FIGURE 19-23. The U.S. 90 bridge across St. Louis Bay, near the western end of the Mississippi coast, collapsed in the massive surge and giant waves as Katrina arrived. The surge and waves must have lifted the bridge deck segments, then dropped them either onto their supports or into the bay.

Northeast of New Orleans, Interstate 10 crosses a 10-kilometer-long causeway over the eastern end of Lake Pontchartrain. The high surge and waves from Katrina, moving west into the lake, lifted segments of the bridge and

dropped them into the lake. The U.S. 90 causeway, which Marvin Nauman photo, FEMA. crosses St. Louis Bay 4( Figure 19-23) and the east end of 4 FIGURE 19-25. Most houses on Dauphin Island, Alabama, the Back Bay of Biloxi, Mississippi, collapsed as a series of were obliterated, leaving behind only some of their posts. tilted road panels. Katrina’s eye tracked almost due north, making landfall on August 29 at 10 a.m. at the border of Louisiana and Mis- ure 19-25). A large volume of sand was eroded from the sissippi. Collapse of an apartment complex killed dozens beach and swept across the island during the storm surge. of people. Some people survived the fast-rising surge by On the mainland the surge, extreme winds, and high climbing into treetops. Given its counterclockwise rotation, waves crushed houses, toppled trees, and severed power the strongest onshore winds, as high as 224 kilometers per lines; transformers exploded, and sailboats broke loose and hour at the deadly eastern edge of the eyewall, hammered were thrown across the coastal highway. A few homes, those the Mississippi coast near Bay St. Louis, where the surge that were specially built to withstand major storms, survived reached its highest level of about 9 meters (30 feet). even where all of the neighboring houses were obliterated The effect of the hurricane on barrier islands along the 4( Figure 19-26). Cars were scattered like toys. coast is well illustrated by the extensive erosion of Dauphin Buildings all along the beachfront from the border of Island, Alabama, east of the hurricane’s eye 4( Figure 19- Louisiana, through Mississippi from Bay St. Louis, Gulfport, 24). Almost all of the homes on the beach side of the road and Biloxi to Pascagoula, were leveled, leaving only the tall running along the island disappeared, leaving only posts. posts and concrete pads to show where they once stood. 2S In some instances, even the posts were snapped off 4( Fig- Many beachfront houses were washed out to sea or under- 1S N 60 60

Hyndman 0495153214 Chapter 19.in60 60 3/9/06 8:17:44 AM Liz Roll photo, FEMA. Mark Wolfe photo, FEMA. 4 FIGURE 19-27. Parts of Slidell, Louisiana, at the northeast 4 FIGURE 19-26. A lone well-built house in Long Beach, edge of Lake Pontchartrain, were reduced to kindling. Mississippi, survived even though its neighbors were obliterated. The lack of nearby debris from those houses suggests that they were destroyed by the storm surge that carried the debris farther inland.

The effect of the storm surge on houses in Gulfport, Mis- mined and toppled, while others were reduced to kindling sissippi, is clear where the lumber that once made up the over large areas, even as far as 2 kilometers from the beach houses in the foreground was swept up and stacked against 4( Figure 19-27). the remaining heavily damaged houses in the background In Gulfport, the surge rose 3 meters in a half hour; fierce 4( Figure 19-28). Buildings lifted from their foundations and winds tore the roofs off eight schools that were being used slammed into nearby buildings are clear evidence of storm as shelters; and a hospital was heavily damaged, as were surge damage, as are huge piles of building debris banked two huge casinos. In Biloxi, seven giant casinos, which were up against one side of buildings with none on the down- floating just offshore because Mississippi laws prevented current side 4( Figure 19-29). them from being built on land, were wrecked. The state’s Farther east in Alabama, a huge oil-drilling platform largest casino, the Grand, was carried more than a kilome- moored at a shipyard floated away and slammed into a sus- ter inland and wrecked. Mississippi, the poorest state in the pension bridge across the Mobile River. Downtown Mobile U.S., needs the tax revenue from the casinos; within two saw severe flooding, not only from the surge but from heavy months a special session of the state legislature permitted rainfall as the storm moved north. Following damage from them to rebuild on land. The Wall Street Journal reported each previous storm in coastal Mississippi and Alabama, on October 15 that people in Mississippi were evicted from developers took advantage of the destruction to build modest rental homes and apartments on the pretense that larger and more expensive structures right to the edge of the buildings were unsafe due to mold even though none the beach. Although many of the high-rise hotels survived was visible. People were suspicious that their dwellings the storm, some of the beaches that attracted them and on would be bulldozed to make room for new casinos and ex- which they were built disappeared, as did most homes be- pensive apartments. hind them.

4 FIGURE 19-28. A nearly new subdivi- sion in a coastal area of Gulfport, Mississip- pi, was leveled, leaving its remains piled up against the battered houses farther inland.

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Hyndman 0495153214 Chapter 19.in61 61 3/9/06 8:17:46 AM 4 FIGURE 19-29. Two-story apartment buildings were lifted from their foundations to crash into adjacent buildings. U.S. Navy photo.

Insurance by everyone in the country. The overall problem is that too many people live in dangerous areas. After the four disastrous hurricanes in 2004, some small Costs paid by homeowners insurance generally include insurance companies left Florida entirely; some large com- physical damages to the home caused directly by winds, panies stopped writing new policies or dropped some flying debris, falling trees, and rain penetration after wind policyholders. Almost all insurance companies significantly damage. In fringe areas of the storm surge, insurance com- increased the cost of coverage after the storms. The same is panies often debate whether the water came from the surge happening as a result of Hurricane Katrina. One big insurer, or from rain. Insurance also often covers the costs, up to Allstate, has indicated that it will reduce its homeowners a specified value, of apartment rental and storage of per- coverage in the Gulf Coast region as a result of $3.68 billion sonal items while the home is being repaired. It will not pay in losses. for the removal of downed trees unless they damaged the A few years ago, governments in states such as Florida, house. FEMA, however, will cover part of the cost of debris Mississippi, and Louisiana created state-run insurance pro- removal under its public assistance program. grams to cover homeowners who are unable to get insur- Flood insurance is not included as part of homeowners ance from private companies; the private insurers in the insurance, but it is available through FEMA’s National Flood state are billed part of the cost, which is then passed on to Insurance Program. However, it is expensive in low-lying ar- policyholders. Now given the severe damage from the hurri- eas and is capped at $250,000 per home. In New Orleans and canes of 2004 and 2005, the states are considering the need its vicinity, more than half of the eligible homes were not in- to dramatically raise their premiums. Rates for everyone in sured for floods, either because people could not afford the the region increased about 10 percent after the 2004 storms, additional expense or didn’t believe they would be flooded. and after the 2005 season they may go up another 10 per- In Mississippi, less than 20 percent of eligible homes had cent. Florida’s state-run insurance pool surprisingly still pro- flood insurance. Since a large part of the damage inlow vides coverage to people building expensive coastal homes areas of New Orleans and in coastal areas of Mississippi and on sites destroyed in recent hurricanes. A recent actuarial Alabama was from storm-surge flooding, homeowners in- (actual cost) analysis indicated that state-run rates should surance did not cover the damage. Flooded homes up to 3 be increased by an average of 80%, and in some areas rates kilometers inland lacked flood insurance. Many were not should more than double. Politicians, however, resist rais- in the floodplain zone designated after Hurricane Camille ing premiums on state-run policies to avoid alienating poli- in 1969, which came ashore in Mississippi as a Category 5 cyholder voters. Thus if the state has insufficient funds to storm, with a 7-meter surge. pay for losses, either the policyholder isn’t paid for a loss Following Katrina, arson fires sprang up in a number of 2S or the state puts pressure on Congress to step in and pay places, leading to the suspicion that some people may have 1S the remainder from federal funds—that is, from taxes paid set fire to their own flood-damaged homes, hoping that their N 62 62

Hyndman 0495153214 Chapter 19.in62 62 3/9/06 8:17:47 AM fire insurance would pay for rebuilding—unless it was de- In other cases, different federal agencies, such as FEMA, termined that the owners set the fires. With no gas or elec- the Department of Transportation, the Occupational Safety tricity in a neighborhood, what else could start a fire but and Health Administration (OSHA), and the National In- arson? stitutes of Health, charged with separate duties, communi- cated poorly with one another. Some did nothing because Predictions, Warnings, and Preparation it was “not part of their jurisdiction.” Much of FEMA’s prob- for the Approaching Storm lems originated with its recent reduction in importance in the federal bureaucracy and decreased funding. The federal In 2004 FEMA prepared a simulation of a major flood of New government had reduced the funding for FEMA, placed it Orleans. The results, although unfinished, were unnerv- under jurisdiction of the Department of Homeland Security, ingly accurate: the simulation left much of the city under and relegated it to a role of responding to disasters instead 3.5 meters of water, similar to what occurred during Katrina. of preparing for or preventing them. It indicated that transportation would be a major problem. A few days before Katrina arrived, the governor of Loui- Before the disaster, local responders were to evacuate hos- siana followed the state disaster plan: she declared a state pitals, nursing homes, and people with special needs. As of emergency, alerted the National Guard, arranged to have Katrina approached, however, it seemed that little thought outgoing traffic patterns on evacuation routes rearranged, had been given to how the tens of thousands of predomi- and made sure that areas considered relatively safe would nantly poor people in the eastern suburbs would evacuate have shelters and supplies for those that were at risk. On when told to do so. August 29, the day the storm made landfall, she asked the Batteries in emergency radios used by the mayor’s group, for “everything you’ve got,” but almost nothing police, and firefighters quickly drained and could not be came. Three days later, she was more specific and requested recharged because the power was out. Unlike radios used 40,000 troops, search-and-rescue teams, buses, amphibious by teams fighting wildfires, which can be powered by or- personnel carriers, communications systems, staging areas, dinary disposable batteries, the radios used by police and housing for large numbers of people, and trailers of water, emergency personnel are powered by rechargeable batter- ice, and food. ies like those in cell phones. FEMA, charged with handling response to disasters, Preparatory response to the approach of Hurricane Ka- proved tragically unprepared and inept. Five hours after trina varied. One would expect the federal government, landfall, FEMA’s director decided to send 1000 federal em- with its vast resources, to be well prepared to deal with such ployees to deal with the storm’s effects but he also seemed a natural disaster, but such was not the case. Among the preoccupied with other personal matters that had nothing best prepared were giant retailer chain stores that specialize to do with anyone’s safety. Supplies were very slow in ar- in keeping prices down by minimizing costs; their readiness riving. The U.S.S. Bataan, with its six operating rooms and was due in part to being extremely well organized and by 600 patient beds, sailed offshore unused. With thousands of having abundant supplies, with numerous warehouses and people sheltered by the Red Cross in the Convention Cen- trucks broadly distributed throughout the country. They ter, FEMA said it had no “factual knowledge” of its use as a were able to get relief supplies to area shelters, including shelter until September 1. truckloads of flashlights, batteries, and ready-to-eat meals. A large group of Florida airboaters offered their services They even provided protective gear and ammunition to law for rescue efforts in New Orleans but FEMA turned them enforcement officers within two days. In contrast, FEMA away, saying that all rescue attempts had to be coordinated had to scramble for days to collect the supplies that they to be effective. FEMA asked for 600 firefighters from around needed. the country to convene in Atlanta with their rescue gear. However, when they assembled on September 5, they were Disaster Response told they would not be involved in a rescue mission and that their job was community relations—they would be passing A big contributor to the poor response to this disaster was out FEMA pamphlets and its phone number! A little later, lack of coordination between government groups with dif- the frustrated and angry firefighters got tired of wasting their ferent responsibilities. Clear-cut lines of authority and com- time and returned home. About two weeks after the storm, munication were not in place. In some cases the head of an the federal political-appointee director of FEMA, a lawyer agency would say to proceed with a plan but lower-level with little experience in disasters, was forced to step down; employees wanted signed papers to protect themselves he was replaced with a senior FEMA employee under him from later criticism. Insistence on formal written authoriza- who had considerable experience. FEMA employees, how- tion before providing help paralyzed some governmental ever, see their role diminished; senior Homeland Security organizations, who were afraid of being sued if they stepped officials are largely telling FEMA what to do. beyond their authority or made a mistake. Some private Arranging temporary housing for an estimated 300,000 groups that saw immediate needs just provided what help displaced people in the wake of Katrina was an immedi- 2S they could without waiting for authorization. ate and enormous task. By September 4, 220,000 refugees 1S N 63

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Hyndman 0495153214 Chapter 19.in63 63 3/9/06 8:17:47 AM cially at the federal level. There were no clear guidelines for coordination or plans for delegation of functions and responsibilities among federal, state, and local agencies. Interagency squabbles on the federal level and quarrels among federal, state, and local governments appeared to involve protecting each organization’s turf. The federal government neglected to stage adequate water, food, medical supplies, and transportation nearby in preparation for post-storm response. Communications failed not only because the electricity went out and the wind dam- aged cell towers, but because rescue organizations used different radio frequencies and couldn’t talk to each other. Hospitals ran out of water and fuel for emergency genera-

Andrea Booher, FEMA. tors. Flooded roads became impassable. Evacuees’ medical problems were compounded by the FIGURE 19-30. Evacuees in the Houston Astrodome were 4 storm. Patients could not find their doctors and doctors moved from the New Orleans Superdome and Convention Center—because of overcrowding and sanitation problems there! could not find their patients. Patients on prescription medi- cations or undergoing specialized treatments often could not remember the names of their medicines or the details of were sheltered in Houston 4( Figure 19-30), San Antonio, their treatments. Years of medical records were lost. Dallas, and other cities across the country. Outside New Our final sentence in Chapter 14, “Hurricanes and Orleans, FEMA provided army-style wood-frame tents and Nor’easters,” alludes to the possibility of incredible flood some travel trailers and mobile homes, but before the damage to New Orleans. The city resides in a location where tens of thousands of trailers could be moved, the sites that the Earth’s surface is constantly adjusting to the forces of would receive them had to have water, sewer, and electric- nature. ity hooked up. Decades of dredging channels for shipping and for em- Private companies began providing space for employ- placement of oil drilling platforms introduced salt water ees to park the trailers next to their plants, with access to and killed off nearby cypress forests and marshes, which drinkable water, sewage services, laundries, and related had previously provided natural protection from the storm necessities. FEMA soon halted their own program because surge and waves 4( Figure 19-31). Oil drilling, refineries, the agency feared that some companies might be using the and shrimp boats share the bayous, though not always ami- trailers to bring in outside workers rather than to house their cably. At the same time, the delta has been sinking because own displaced workers. The agency also insisted that each the levees of the Mississippi River and its tributaries have site be reviewed to avoid violating environmental laws, in- deprived the delta of sediment that was once replenished cluding those involving air, water, soil, hazardous materials, annually. A four-year, $500 million federal project to restore and endangered species. Clearly such a bureaucratic pro- coastal wetlands was awarded in July 2005; this should help cess would take months, if not years, to provide people with in the future. temporary housing. The underlying problem, revisited elsewhere in this Even a month after the hurricane, few residents had book, is that many officials in high positions in government been permitted to return to their homes in New Orleans due to the lack of electricity, potable water, and sewer ser- vice. Residents from the French Quarter, the Garden Dis- trict, and Tulane University on the natural levee north of the Mississippi River could move back relatively soon after the storm because flooding in those areas was less than a meter deep and drained quickly. However, in most of the city, power lines still dangled, tree branches and other de- bris still clogged the streets, and no stores or gas stations had reopened.

What Went Wrong? Many deficiencies could have been easily and -inexpen sively fixed. Thousands of predominantly poor people had 2S no way to leave the city. Tens of thousands of people had Don Hyndman photo. 1S to wait days before relief supplies or rescue came. Progress 4 FIGURE 19-31. Cypress forests near New Orleans present a N was hampered by lack of planning and organization, espe- formidable barrier to an advancing storm surge. 64 64

Hyndman 0495153214 Chapter 19.in64 64 3/9/06 8:17:48 AM and in some of the agencies that they oversee, along with a building-supply stores; no schools; and no funds from prop- majority of the public, view nature as something to be con- erty or sales taxes with which to pay the city or parish em- trolled or held at bay. When asked if New Orleans could ployees needed to repair roads and utilities. Teachers have survive another hurricane, a senior manager of the Corps of no schools or students; doctors have no patients and have Engineers replied that it certainly could, even a Category 5 lost the records of patients they once had. Even people with because “higher levees would solve the problem.” Unfortu- jobs in rebuilding or at restarted refineries face difficulties: nately they have taken that approach—raising the levees af- where will they live, get groceries or gas, or find schools ter each major flood—along the Mississippi River for many for their children? Without people in the area, there are no decades and still some levees fail and the river floods. Other jobs; without jobs, people cannot return. geologists who have spent decades studying sinking eleva- tions around the Gulf Coast say that the delta and New Or- Rebuilding? leans had subsided deeper than expected and the problem could be greater than the engineers estimated. The Corps of If people rebuild, what changes should they make in the Engineers had repeatedly requested funds to upgrade the design and materials of a new home? Since most dam- levees, but before the storm Congress and the White House age is caused by wind, water, and mold, FEMA and con- planned to cut the Corps’ annual budget rather than to in- struction experts suggest using stronger materials that are crease it to deal with such problems. This great city has suf- firmly attached to adjacent parts of the house. In addition fered a calamity from which it may not survive in anything to recommendations noted in Chapter 14, metal wall studs, like its present form. nonporous wallboard, and closed-cell spray-foam insula- tion are much stronger than wood and sheetrock, and are less susceptible to mold. Windows, the weakest parts of The Future of New Orleans? walls, can be strengthened with impact-resistant glass that has clear plastic laminate between panes. Use of premium An important question is whether New Orleans should be polyurethane adhesive (Super Glue), along with nails and rebuilt in essentially its previous form. Should people be wood screws to hold plywood to ceiling joists helps pre- permitted to rebuild in a huge sinking depression several vent roof loss. meters below sea level and below the Mississippi River, or Katrina was the costliest natural disaster to strike North should aid for reconstruction come with the requirement America to date. Private insurer costs are expected to be that any new home be situated above sea level and outside $34 billion; federal government appropriations reached the floodplain? The latter was one of FEMA’s main require- $71 billion within three months following the storm. Some ments for people and companies seeking funds for rebuild- estimates suggest that total costs could top $200 billion, ing structures along rivers; this rule was put into effect after including payments to businesses and individuals, but the the disastrous 1993 upper Mississippi River flood. federal government seems to be backing off on initial prom- Certainly the higher-elevation areas of New Orleans, ises. After three months, FEMA had not allocated $37.5 bil- those on the natural levees of the Mississippi River, should lion of the federally appropriated funds. be restored. These areas provide the shipping and indus- The Corps of Engineers plans to repair 60 kilometers trial facilities that serve not only the Mississippi River ba- of the 480-kilometer levee system to withstand a Category sin but much of the rest of the country. Some of those port 3 storm. Improved sections will be 5.2 meters high rather facilities could be moved upriver 150 kilometers or so to than the previous 3.8 meters high. Rebuilding the system Baton Rouge, which is also a dredged deepwater port. Many to withstand a Category 5 storm would cost more than New Orleans residents and businesses have already moved $32 billion—that is $66,000 for each of the 485,000 original to Baton Rouge, causing problems there with unexpected residents, more than that for the fewer that are expected growth. One quarter of the city’s current residents now fall to return! The cost would include the required higher and below the poverty level. stronger levees, sea gates across shipping canals, and resto- The prospect of a permanent relocation of much of New ration of protective wetlands. Orleans’ population to Baton Rouge brings to mind the mi- gration of people and businesses from Galveston, Texas, to Not the First Time nor the Last the then small town of Houston after the disastrous 1900 Galveston hurricane. Most of those people never returned Hurricanes have affected New Orleans before. Betsy, a Cate- to Galveston. gory 3 hurricane, submerged almost half of New Orleans in New Orleans’ natural-levee areas also make up the cul- 1965; some places were under as much as 6 meters of water. tural and historical part of the city frequented by tourists The storm left 60,000 people homeless. Congress then au- that provide a large portion of the city’s income. These ar- thorized a gigantic construction project to raise the levees eas include the famous French Quarter, which was only and link them to the Mississippi River levees to prevent such lightly damaged. Even in areas that should be rebuilt, where flooding ever again. After Katrina, a similar flood control 2S do you start? Two months after the storm, large devastated construction project would likely involve protection against 1S areas had no gas stations; no open grocery, hardware, or Category 5 storms, cost billions of dollars, take decades to N 65

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Hyndman 0495153214 Chapter 19.in65 65 3/9/06 8:17:48 AM complete, and include abandoning especially low-lying ar- of storms— Categories 4 and 5—has nearly doubled to eas. As the city and its levees continue to sink, it would be eighteen worldwide. Hurricane development and intensity just a matter of time before the next catastrophic flood. depends on energy provided by higher sea-surface tem- Devastating hurricanes over the last few years seem to peratures; an increase of about 0.6°C (1°F) over the last be increasing in number, intensity, and cost. Charley, Fran- dozen years may not seem like much but it makes a differ- ces, Ivan, and Jeanne produced a remarkably destructive ence by fueling the storm with warm, humid air. More water season in 2004. Then in August 2005, Hurricane Katrina vapor drawn into the atmosphere in these intense storms destroyed New Orleans and coastal Mississippi. Hurricanes leads to heavier rainfall accompanying the storms—and Rita and Wilma followed in September and October. All more flooding. Whether part of the increase in hurricane three of these storms reached Category 5 intensity in the strength is in response to global warming is still debated, Gulf of Mexico before weakening slightly before landfall. but most of the increase is attributed to a cycle of cooling The 2005 season also has the dubious distinction of having and warming over a span of sixty to seventy years called the the largest number of named tropical storms and hurricanes Atlantic Multidecadal Oscillation (AMO). Since 1995, the in the fifty-two years that we have been giving them names. Atlantic sea surface has warmed and hurricane activity has Is the increase in intense hurricanes and their accompany- increased significantly. The water temperatures in the Carib- ing heavy rainfall a response to global warming? bean Sea and the Gulf of Mexico were extraordinarily warm The number of hurricanes has not increased significantly, in 2005. but since 1990 the annual number of the most intense types

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