Typhoon Haiyan

Haiyan slammed into the Philippines on 8th November 2013 with the force of a category 5 Atlantic hurricane, at a speed of 250kmh^-1. It came with a 5m storm surge and up to 290 mm of rainfall in just 12 hours. Haiyan was likely known as Yolanda. Fewer than 20 other hurricanes had reached the same strength.

Between 5 and 10 typhoons hit the Philippines every day, leading to, within normal bounds, 2% of GDP lost annually.

Top Five Natural Disasters, 2004-2012 in the Philippines Date Number Kiled
Typhoon Bopha Dec 2012 1,901
Typhoon Winnie Nov 2004 1,619
Typhoon Washi Dec 2011 1,439
Typhoon Durian Nov 2006 1,399
Leyte landslide Feb 2006 1,126

Bopha had a windspeed of 280kmh^-1 and hit the island of Mindanao. It caused over US$1 billion of damage. Yet no one remembers Bopha. This reflects how the richest countries tend to ignore the issues that prevent development in other countries once the immediate issue appears to be dealt with.

Many people made the link between Haiyan and climate change:

“I’ll leave the scientists to speak for themselves about the link between severe weather events and climate change. The evidence seems to me to be growing.”- David Cameron

Rising sea levels from melting ice caps mean that areas which are low lying or coastal are at more risk of damage from storm surges and other sea based hazards linked with the hurricane. An IPCC AR5 report judged that there would be no real increase in the number of hurricanes but the intensity of them would rise.

Date Development of Haiyan
2 Nov An area of low pressure developed South East of Micronesia
3 Nov Haiyan started to move westward, turning into a tropical depression
5 Nov Classified as a typhoon
6 Nov Joint Typhoon Warning Centre classified it as a category 5 storm
7 Nov Haiyan intensified to winds up to 314kmh^-1. Made landfall at Guiuan, Eastern Samar.
8 Nov Five more landfalls within the Philippines. Passed into the South China Sea
10 Nov Turned NW and made landfall in Vietnam as a category 1 typhoon
11 Nov Weakened to a tropical depression

Causes

To form, hurricanes, typhoons and cyclones (the same thing by different names depending upon location), need warm deep water (around 27°C for 70m) and sufficient rotatory power from the Coriolis effect; the coriolis limitation means that tropical storms can rarely be formed outside of about 5-20° away from the equator. Tropical storms form around an area of low pressure- Haiyan’s sea surface pressure was as low as 895mb- where air starts to rush in in a spiralling effect.

The air then starts to rise with warm water evaporating off the warm sea, forming clouds. The clouds then start to rise. The accumulation of air at the top creates a higher section of high air pressure. Air is then blasted out at immense speeds, creating the clouds visible on satellite images.

Hurricanes maintain their full force when they are over warm water with no real wind sheer (high up winds which move the top layer of cloud away from the hurricane). In the Philippines, most of the land is made of small islands with larger sections of warm water between them, meaning that the hurricane never gets far away from warm water when over the Philippines, and thus don’t really weaken around the country.

Across the Philippines, Haiyan made 6 separate land falls. It travelled very quickly, meaning that the water in front of it was not stirred up. Stirred up water will often have cold water near the surface, but the water in front of Haiyan did not. This meant that the water entering the typhoon was very warm, so when it rose it released masses of latent heat energy, giving the typhoon enormous power.

The islands of Leyte and Cebu’s configuration channeled the storm in a particular way, funneling it straight towards the city of Tacloban; the decreasing ocean depth also increased the intensity of the storm surge.

Lowest Pressure 895 mb
Sustained wind speed 314 kmh^-1
Radius of hurricane-force winds 85 km
Peak Strength Category 5
Strength at Landfall Category 5, 314 kmh^-1
Storm Surge Height 15 m
Rainfall 400mm

There had also been an earthquake (at 7.2 on the Richter scale) recently beforehand, in October 2013, which had an impact on how effective any aid work could be.

Impacts

Haiyan affected 11 million people.

  • 6,021 were killed, although the initial estimate was 10,000
  • 10,000s of people were made homeless, and further 10,000s lost their main sources of income.
  • The Tacloban City Convention Center was being used as an evacuation centre, but became a death trap as water poured into it.
  • A 5.2 m storm surge destroyed Tacloban airport’s terminal building.
  • Many water vessels were washed ashore; in some areas 95% of fishing equipment and boats were destroyed.
  • The phone network was lost, making it hard to establish contact between victims, the authorities, and the victims’ families.
  • 1,000s of trees were destroyed; 33 million coconut palms were destroyed, destroying 15 million tons of timber.
  • Roads were undamaged, but huge piles of debris still made transportation of aid workers and supplies very slow.

The worst affected area, the Eastern Vasayas were flooded up to 1km inland.

There was no clean water, electricity or food for survivors. There was also no available fuel for vehicles, many of which were also upturned.

 

Response

Preparedness

The Philippines has many low scale hurricanes on a regular basis; thus, many people had a false sense of safety going into the disaster because they had been desensitized to the danger of it.

The government frequently produces risk maps and provides evacuation shelters for its citizens.

On November 6th, PAGASA (Philippines Atmospheric, Geophysical and Astronomical Services Administration) issues a low level Public Storm Warning, but had raised this to the highest level it could within 24 hours.

The military deployed planes and helicopters in advance to areas likely t be worst-hit. Community buildings were designated as storm shelters, although there was concern that they may not resist the high wind force. Some islands, such as Tulang Diyot, were completely evacuated of its 1,000 residents, due to years of education and community preparedness.

The local mayor of Tulang Diyot won an award in 2011 for community work in the “Purok system”, where community members agree to deposit their own money into a fund for post-disaster assistance rather than waiting for government aid.

Short Term

When Haiyan made land fall, the International Charter on Space and Major Disasters was activated, allowing relief agencies to have satellite data from space agencies to help in relief and recovery after a disaster.

Journalists arrived very quickly to the area, largely consisting of storm chasers who arrived before the storm to help contribute to better models for use in predicting the effects and severity of future disasters.

The first actual aid work was done by survivors who searched the ruins for bodies and other survivors. The government was criticised for a very slow response, as locals turned to looting to acquire enough food for themselves. The UK and USofA sent supplies of diggers, and other moving equipment to help the distribution of aid. Aid supplies were often ambushed and looted. Mass graves were dug to contain the bodies before disease could break out.

Pledges of aid were made quickly but the actual carrying out of the aid schemes was severely delayed, partly because of the isolated nature of the effected islands, and the damage done to infrastructural and transport links.

Street sellers had started to set up stands again a week after the event. Fishermen salvaged water proof items to turn into impromptu boats, such as tree trunks and fridges. Broadband antennae were constructed and Micromappers.com managed to map out the worst hit areas to send workers into where they were most needed.

Long Term

Water and sanitation services were set up fairly soon afterwards. Cebu Chamber of Commerce and Industry, representing 3,000 small businesses set up a permanent disaster committee. A month after the event, 100,000 people were still in evacuation centres, with 4 million in temporary homes. 324,00 households were given materials for emergency shelters, and began building 30,000 higher standard homes.

If material distribution had been slower, many people would have started to just rebuild with what they had, leading to more unsafe structures than what was there before the event.

Representatives of national and local governmental departments started administering aid directly, speeding up distribution and reducing bureaucracy. 50,000 homes in affected areas were given US$50 in addition to emergency supplies, overseen by the Philippines Red Cross.

People started to be paid for clearing up the mess, allowing them structure back into their lives while also helping the aid work.

There were no outbreaks of diseases, despite the large risk and the lack of initial sanitation.

More than 20% of government spending in the Philippines is on debt repayment. This crippling cost keeps much of the population in poverty and at risk of another disaster.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s