Читать книгу Disaster Response and Recovery - David A. McEntire - Страница 23

An atmospheric hazard is a hazard agent that is produced in or by the earth’s atmosphere. A hurricane is one type of atmospheric hazard (Figure 1‐2). Hurricanes begin as tropical depressions in the Atlantic Ocean and form as low‐pressure systems due to the warm water that fuels them. When wind speeds top 74 mph, such

tropical depressions become known hurricanes. In the Indian Ocean, these tempests are known as cyclones, and in the Pacific Ocean they are labeled typhoons. The eye or center of these storms is somewhat calm, but it is surrounded by circling cloud bands that produce rain in large amounts. Some hurricanes may have winds in excess of 100 or even 200 mph, and they may produce a storm surge that could reach up to 24 feet. The strength of a hurricane is described under the Saffir–Simpson scale. The Saffir–Simpson scale is a descriptive tool to explain the magnitude of a hurricane in terms of wind and storm surge. It includes five categories. Category 1 is the weakest, while Category 5 is the strongest (see Table 1‐2).

This scale also estimates potential property damage. On the lower end of the scale, category 1 and 2 storms are smaller, but could nevertheless be dangerous and still require preparatory measures. Hurricanes reaching Category 3 and higher are considered major storm systems because of their potential for significant loss of life and damage. In the western North Pacific, the term “super typhoon” is used for tropical cyclones with sustained winds exceeding 150 mph.

In the Northern Hemisphere, hurricanes rotate in a counterclockwise direction and travel in a west–northwesterly direction. They frequently hit Atlantic states and those along the Gulf Coast. Florida is one of many states that frequently experiences hurricanes. For instance, Hurricane Andrew made landfall on August 24, 1992, and its strong winds devastated the Miami‐Dade area. This hurricane produced dozens of deaths and left thousands of people without power and shelter. Weak building codes and poor enforcement resulted in major structural collapses and a debris management nightmare. Hurricane Andrew’s impact on Florida was surpassed by the combined four hurricanes and one tropical storm that hit Florida in 2004. This was one of the worst hurricane seasons on record, but such storms have become even more problematic over the past few decades.

Table 1‐2 Saffir–Simpson Hurricane Scale.

Source: Adapted from Saffir‐Simpson Hurricane Wind Scale, NOAA. http://www.nhc.noaa.gov/aboutsshws.php.

Category	Sustained winds	Types of damage due to hurricane winds
1	74–95 mph64–82 kt 119–153 km/h	Very dangerous winds will produce some damage: well‐constructed frame homes could have damage to roof, shingles, vinyl siding, and gutters. Large branches of trees will snap and shallowly rooted trees may be toppled. Extensive damage to power lines and poles likely will result in power outages that could last a few to several days.
2	96–110 mph83–95 kt 154–177 km/h	Extremely dangerous winds will cause extensive damage: well‐constructed frame homes could sustain major roof and siding damage. Many shallowly rooted trees will be snapped or uprooted and block numerous roads. Near‐total power loss is expected with outages that could last from several days to weeks.
3 (major)	111–129 mph96–112 kt 178–208 km/h	Devastating damage will occur: well‐built framed homes may incur major damage or removal of roof decking and gable ends. Many trees will be snapped or uprooted, blocking numerous roads. Electricity and water will be unavailable for several days to weeks after the storm passes.
4 (major)	130–156 mph113–136 kt 209–251 km/h	Catastrophic damage will occur: well‐built framed homes can sustain severe damage with loss of most of the roof structure and/or some exterior walls. Most trees will be snapped or uprooted and power poles downed. Fallen trees and power poles will isolate residential areas. Power outages will last weeks to possibly months. Most of the area will be uninhabitable for weeks or months.
5 (major)	157 mph or higher137 kt or higher 252 km/h or higher	Catastrophic damage will occur: a high percentage of framed homes will be destroyed, with total roof failure and wall collapse. Fallen trees and power poles will isolate residential areas. Power outages will last for weeks to possibly months. Most of the area will be uninhabitable for weeks or months.

 In 2008, Hurricane Ike affected Mississippi, Louisiana, and Texas. It killed nearly 200 people and resulted in over $37 billion in damages.

 “Superstorm Sandy,” as one of the largest hurricanes in history, made landfall north of Atlantic City in 2012 and decimated many buildings near the coast. The storm flooded subway stations in New York City and caused $65 billion in damages in many of the other northeastern states.

 In 2017, Hurricane Harvey pounded Texas and Louisiana, resulting in $125 billion in losses. That same year, Hurricane Maria impacted Puerto Rico with loss estimates over $90 billion.

 In August 2018, Hurricane Florence struck North Carolina and killed an estimated 3.4 chickens and 5,500 pigs. A month later, Hurricane Michael flattened structures in Mexico Beach, Panama City, and Port St. Joe with its 160 mph winds and 9‐ to 14‐foot storm surge. Hurricane Michael killed 16 people and produced $25 billion in losses.

Hurricane Ida affected Louisiana in 2021. It caused serious devastation and resulted in 1 million people without power. The remnants produced major flooding in New York and New Jersey. Nearly 80 individuals died in the United States.

Although the above storms were problematic, all of these hurricanes combined did not result as many deaths as a cyclone that hit Bangladesh in 1970. It tragically killed as many as 300,000 people and illustrated that hurricanes can be particularly devastating in developing nations.