Short and long-term responses: risk management designed to reduce the impacts of the hazard through preparedness, mitigation, prevention and adaptation.
Impacts and human responses as evidenced by two recent tropical storms in contrasting areas of the world.
The nature of tropical storms
Tropical storms are weather depressions cause by low pressure. they have different names in different parts of the world:
In the Atlantic, they are known as hurricanes.
In the pacific they are known as typhoons.
In the Indian ocean they are known as cyclones.
All of these tropical storms need the same conditions to form and can cause severe disruption.
How do tropical storms develop?
Tropical cyclones are like giant engines that use warm, moist air as fuel. That is why they form only over warm ocean waters (>27 degrees) near the equator. The warm, moist air over the ocean rises upward from near the surface. Because this air moves up and away from the surface, there is less air left near the surface. Another way to say the same thing is that the warm air rises, causing an area of lower air pressure below.
Air from surrounding areas with higher air pressure pushes in to the low pressure area. Then that "new" air becomes warm and moist and rises, too. As the warm air continues to rise, the surrounding air swirls in to take its place. As the warmed, moist air rises and cools off, the water in the air forms clouds. The whole system of clouds and wind spins and grows, fed by the ocean's heat and water evaporating from the surface. Storms that form north of the equator spin counterclockwise. Storms south of the equator spin clockwise. This difference is because of Earth's rotation on its axis, known as the Coriolis force. As the storm system rotates faster and faster, an eye forms in the center. It is very calm and clear in the eye, with very low air pressure. Higher pressure air from above flows down into the eye.
Classification of tropical storms
Tropical storms are classified according to their speed on the Saffir-Simpson scale.
Nature of the storm hazard
Tropical storms create a number of potentially life threatening hazards.
high winds: buildings can be damaged or destroyed; trees, power and telephone lines toppled; debris turns into projectiles.
storm surge: a hurricane can provoke a temporary rise in sea level of several meters which can flood coastal areas and damage buildings on the shoreline.
very heavy rainfall: this can cause localised or widespread flooding and mudslides.
Tropical storms can seriously damage and disrupt a country’s infrastructure, including buildings, roads and communications. PRIMARY EFFECTS OF TROPICAL STORMS The primary effects of a tropical storm are the immediate impacts of strong winds, heavy rainfall and storm surges. These include:
People are injured or killed by debris being blown around
Drowning
Buildings are destroyed or damaged
Electric supplies are cut off due to power lines being destroyed
Sewage is released due to flooding
Water supplies become contaminated
SECONDARY EFFECTS OF TROPICAL STORMS Secondary effects are the impacts following the storm. This can include:
People being left homeless
A lack of clean water and sanitation – water-borne diseases can affect local people
Road and rail networks can be blocked by debris making it difficult to provide support and aid for people in the affected area
Unemployment caused by businesses being damaged
If crops are destroyed and/or livestock is killed there can be a shortage of food
HUMAN RESPONSES
Immediate responses occur during the time before the storm is forecast to make landfall and immediately after the event.
people are evacuated before the storm lands
rescue people trapped and provide medical support for injured people
temporary shelters are set up for people made homeless by the storm
provide water and food for people
recover dead bodies
digital maps are updated immediately after the storm using satellite photographs to support emergency services on the ground
Aid provided by Governments and NGOs such as Oxfam.
LONG-TERM RESPONSES TO TROPICAL STORMS Long-term responses are those responses that involve returning an area back to the way it was before the storm and preparing for future storms.
repair and rebuild properties
rehouse people
repair the transport infrastructure
improve forecasting and early warning systems
provide grants and aid to people to help rebuild their homes
improve building regulations so that properties are constructed to better withstand the impacts of tropical storms
Offer incentives such as tax breaks to encourage economic recovery
Background Hurricane Katrina is the costliest natural disaster in the history of the United States. Among recorded Atlantic hurricanes, it was the sixth strongest overall but what made it deadly was where it hit and the physical and human geography of that region. . At least 1,836 people died in the actual hurricane and in the subsequent floods and total property damage was estimated at $81 billion. Hurricane Katrina began as a very low pressure weather system, which strengthened to become a tropical storm and eventually a hurricane as it moved west and neared the Florida coast on the evening of 25 August 2005. After crossing southern Florida - where it left some 100,000 homes without power - it strengthened further before veering inland towards Louisiana, eventually making landfall at Grand Isle, approximately 90km south of New Orleans, at 10am local time on 29 August. At this point, Katrina's sustained wind speed was approximately 200 km/h. The storm passed directly through New Orleans, destroying many lighter buildings and causing extensive damage to others. Hurricane force winds were recorded along a 200km stretch of coastline, with scenes of similar destruction and flooding in Louisiana, Mississippi and Alabama. Storm surges from the sea caused flooding several kilometres inland in some places.
Impacts
Economic Impacts
The Bush Administration sought $105 billion for repairs and reconstruction in the region, this didn’t include potential interruption of the oil supply, destruction of the Gulf Coast's highway infrastructure, and exports of commodities such as grain.
Katrina damaged or destroyed 30 oil platforms and caused the closure of nine refineries;
1.3 million acres (5,300 km2) of forest lands were destroyed costing about $5 billion
Before the hurricane, the region supported approximately one million non-farm jobs, with 600,000 of them in New Orleans.
It is estimated that the total economic impact in Louisiana and Mississippi may exceed $150 billion
Additionally, some insurance companies have stopped insuring homeowners in the area because of the high costs from Hurricanes Katrina and Rita, or have raised homeowners' insurance premiums to cover their risk
Environmental Impacts
The storm surge caused substantial beach erosion, in some cases completely devastating coastal areas. In Dauphin Island, approximately 90 miles (150 km) to the east of the point where the hurricane made landfall, the sand that comprised the barrier island was transported across the island into the Mississippi Sound, pushing the island towards land
The US Geological Survey has estimated 217 square miles (560 km2) of land was transformed to water by the hurricanes Katrina and Rita
The lands that were lost were breeding grounds for marine mammals, brown pelicans, turtles, and fish
The damage from Katrina forced the closure of 16 National Wildlife Refuges.
The storm caused oil spills from 44 facilities throughout southeastern Louisiana, which resulted in over 7 million U.S.gallons (26 million L) of oil being leaked.
Finally, as part of the cleanup effort, the flood waters that covered New Orleans were pumped into Lake Pontchartrain, a process that took 43 days to complete. These residual waters contained a mix of raw sewage, bacteria, heavy metals, pesticides, toxic chemicals, and oil, which sparked fears in the scientific community of massive numbers of fish dying
Social Impacts
Katrina redistributed over one million people from the central Gulf coast elsewhere across the United States. For example, Houston, Texas, had an increase of 35,000 people
By late January 2006, about 200,000 people were once again living in New Orleans, less than half of the pre-storm population.
By July 1, 2006, when new population estimates were calculated by the U.S. Census Bureau, the state of Louisianashowed a population decline of 219,563, or 4.87%
Many people were totally traumatised
Racial tensions were exposed and intensified, as many of the victims were black African Americans
Responses
Most of the management and aid in response to hurricane Katrina came from within the USA (INTERNAL FEDERAL aid). The storm was predicted by the National Hurricane centre and they gave a very accurate plot of the Hurricanes track and expected landfall, not far from New Orleans. This allowed for a coordinated EVACUATION but many people were left behind and many refused to move. This warning also allowed some disaster recovery response to Katrina began before the storm, with Federal Emergency Management Agency (FEMA) preparations that ranged from logistical supply deployments to a mortuary team with refrigerated trucks. Many volunteers gave assistance to local residents and residents emerging from New Orleans and surrounding parishes as soon as the storm made landfall (even though many were directed to not enter the area), and continued for more than six months after the storm. Of the 60,000 people stranded in New Orleans, the Coast Guard rescued more than 33,500. The United States also had a military on-scene response on Sunday, August 28. Approximately 58,000 National Guard personnel were activated to deal with the storm's aftermath, with troops coming from all 50 states. Early in September, Congress authorised a total of $62.3 billion in aid for victims. FEMA provided housing assistance (rental assistance, trailers, etc.) to more than 700,000 applicants—families and individuals. However, only one-fifth of the trailers requested in Orleans Parish were supplied, resulting in an enormous housing shortage in the city of New Orleans. Many local areas voted to not allow the trailers, and many areas had no utilities, a requirement prior to placing the trailers. To provide for additional housing, FEMA has also paid for the hotel costs of 12,000 individuals and families displaced by Katrina through February 7, 2006, when a final deadline was set for the end of hotel cost coverage. As of March 30, 2010, there were still 260 families living in FEMA-provided trailers in Louisiana and Mississippi. Law enforcement and public safety agencies responded with manpower and equipment from as far away as California, New York, and Texas. This response was welcomed by local Louisiana authorities as their staff were either becoming fatigued, stretched too thin, or even quitting from the job.
Two weeks after the storm, more than half of the states were involved in providing shelter for evacuees. By four weeks after the storm, evacuees had been registered in all 50 states and in 18,700 zip codes—half of the nation's residential postal zones. Most evacuees had stayed within 250 miles (400 km), but 240,000 households went to Houston and other cities over 250 miles (400 km) away and another 60,000 households went over 750 miles (1,200 km) away.
The government was critised for its response, with many critics claiming it was very slow to respond and that the management lacked coordination. The use of emergency centres was also criticised, with the Louisiana Superdome (designed to handle 800, yet 30,000 arrived) and the New Orleans Civic Center (not designed as an evacuation center, yet 25,000 arrived) deemed by many as inadequate. Race and class were also stipulated as issues, with Kanye West claiming that there was a racial reason for the slow response, given that most of the stranded people were African American. The international community also responded quickly, with over seventy countries pledging monetary donations or other assistance. Kuwait made the largest single pledge, $500 million; whilst India sent tarps, blankets and hygiene kits. An Indian Air Force IL-76 aircraft delivered 25 tonnes of relief supplies for the Hurricane Katrina victims at the Little Rock Air Force Base, Arkansas on September 13, 2005. Charitable NGOs such as the American Red cross also waded in with assistance.
LIC case study: Typhoon Haiyan
Background Typhoon Haiyan was a tropical cyclone that affected the Philippines in South East Asia in November 2013. It was one of the strongest tropical cyclones ever recorded with winds of 313 km/h. In some areas, 281.9 mm of rainfall was recorded, much of which fell in under 12 hours. Waves of up to 7 m in height battered the coast. The Philippines is a fairly poor part of the world with minimal investment in prediction, planning and protection schemes.
Impacts Economic impacts
The overall economic impact of Typhoon Haiyan is estimated at $5.8 billion (£3.83 billion).
Six million workers lost their sources of income.
Major rice, corn and sugar-producing areas for the Philippines were destroyed affecting the country's international trade and farmers' incomes.
Tacloban's city airport was severely damaged, affecting business and tourism.
Fishing communities were severely affected with the storm destroying 30,000 boats and associated equipment.
Social impacts
More than 7,000 people were killed by Typhoon Haiyan.
1.9 million people were left homeless and more than 6,000,000 displaced.
There were outbreaks of disease due to the lack of sanitation, food, water, shelter, and medication.
Less affected areas reported that their populations more than doubled after the typhoon with the influx of refugees.
The Tacloban city government was devastated, with only 70 people at work in the immediate days after the disaster compared to 2,500 normally. Many were killed, injured, lost family or were simply too traumatised to work.
In the city of Tacloban, widespread looting took place in the days following the typhoon.
Environmental impacts
Widespread floods damaged and in many cases destroyed homes and businesses in coastal areas.
The Philippine government estimated that about 71,000 hectares of farmland was affected.
Thousands of trees were uprooted leading to a massive release of carbon dioxide and loss of habitat with resulting effects on wildlife.
Flooding knocked over Power Barge 103 causing an oil spill affecting mangrove ecosystems.
Major roads were blocked by trees, and were impassable.
Responses
Even though the loss of life was significant, it could have been much worse if not for the efforts of PAGASA, the Philippines' meteorological agency. It broadcast warnings two days before Typhoon Haiyan hit, leading to the evacuation of approximately 750,000 residents.
The Philippines formally declared 'A State of National Calamity' and asked for international help, one day after Typhoon Haiyan hit the country.
The UK government provided food, shelter, clean water, medicine and other supplies for up to 800,000 victims.
Several charities provided emergency aid such as water, food and shelter. In the longer term, they are helping people get their livelihoods back, for example by repairing fishing boats or distributing rice seeds.
The United Nations launched an international aid appeal in December 2013 for £480 million to finance the humanitarian relief effort for 2014.
In 2014, the Philippines commissioned billboards in some of the world's prime advertising sites such as New York's Times Square and London's Piccadilly Circus to thank people for their help after Typhoon Haiyan.