On the 4th of September 2018, Japan was assailed by Typhoon Jebi, one of the most powerful typhoons it had encountered in a quarter of a century. While Typhoon Jebi wreaked havoc across much of the densely-populated island country, nobody could ignore the extensive damage inflicted on one of Japan’s greatest engineering wonders which was also a homage to Japan’s construction genius – Osaka’s Kansai International Airport.
Kansai Airport flooded by Typhoon Jebi. (Photo from Kyodo)
Opened in 1994, Kansai International Airport was built entirely as an artificial island with a bridge linking it to the city of Izumisano on the Japanese mainland. The new airport was a symbolic of Japan’s technological prowess. It was unfortunate that in its 24th year of operation, Typhoon Jebi would leave behind nothing but flood waters at one of the airport terminal’s basement floors as well as on the runways, resulting in the cancellation of over 700 flights and several planes submerged up to their engines. To add on to the damage, the strong winds of Typhoon Jebi sent a 2,591 tonne-tanker crashing into the bridge linking the airport to the Japanese mainland, stranding a few thousand tourists at the airport.
While Typhoon Jebi was one of the most powerful typhoons to ever hit Japan, it is a symbolic of a precarious planet that has been facing more and more severe natural disasters in the form of extreme weather phenomena such as typhoons, floods and droughts in the past few years. These natural disasters have resulted in extensive losses of homes, human lives as well as damages to public and private property. In the context of this paper, we will focus here on the impact of the increase in natural disasters as a result of extreme weather on airports.
Whither Climate Change?
There is a question that is often being raised: the question is once again being raised: is climate change causing more typhoons and stronger typhoons?
According to atmospheric scientist Professor Johnny Chan Chung Leung in an interview with the South China Morning Post, there is no “simple” or conclusive answer to the above question.
While Professor Chan acknowledges that the warming of ocean waters results in increased evaporation into the atmosphere which in turn creates the conditions for typhoons to form, there are also atmospheric factors that result in the formation of typhoons. There is currently little evidence however showing whether atmospheric conditions are more or less favourable for the formation of typhoons.
Professor Chan also mentioned that decades of research have shown that there appear to be natural cycles in typhoon activity, regardless of activity or intensity. However, climate change would modify these cycles.
While United Nations Secretary-General António Guterres said that it was not possible to link a single weather event to climate change, he acknowledged that scientists were predicting that extreme weather events would be “the new normal of a warming world.”
While there is still much dispute about how much of climate change is generated by human activity and to what extent it is responsible for extreme weather phenomena in recent times, it is difficult to deny that the earth is visibly undergoing a period of global warming which has resulted in the melting of ice-caps and glaciers.
Melting Ice Sheets (Credit: David Merron Getty Images)
The melting of ice-caps and glaciers have in turn resulted in rising sea levels - according to a new study based on 25 years of NASA and European satellite data, global sea level rise is accelerating incrementally over time rather than increasing at a steady rate as previously thought - and in the context of this paper, an increased vulnerability of airports to floods.
Impact of extreme weather conditions on airports
Airports have often been built in locations that are close to sea level – the reasons boiling down to practicality and convenience. They require large areas of flat land for the placement of runways and to allow for aircraft to take-off and land without facing obstacles. Historically, this type of space has been found on wetlands, marshlands and floodplains – all near large bodies of water.
According to Airport Councils International, 15 of the 50 busiest airports globally are at an elevation of less than 30 feet (9 metres) above sea level, making them particularly vulnerable to a changing climate, including rising sea levels and associated higher storm surges.
Even if we do not consider cases of airports being flooded because of typhoons (or hurricanes) as in the case of Kansai International Airport in September 2018 or LaGuardia Airport in June 2013, there have already been cases of airports in low-lying areas experiencing floods due to the increase in the surrounding water levels, often due to heavy rain.
As an example, St. Paul Downtown Airport in Minnesota has been overrun by the nearby Mississippi River so many times that it now has a portable flood wall it can erect in flash flood situations.
Cochin International Airport in Kerala, India, closed for almost two weeks in August 2018 due to flooding after the Periyar River burst its banks in the heaviest rain to hit the state since the 1920s. The floods submerged a runway and damaged 2.6 km of perimeter wall.
Don Muang Airport (also Don Mueang) in Thailand started to flood on October 25 2011 during a period of high tides.
Flooding at Don Muang Airport in October 2011(Image from Google Earth)
The increase in sea levels globally is also expected to increase the vulnerability of airports in low-lying areas to floods. If the rate of ocean rise continues to change at its current pace, sea levels will rise 65 centimetres by 2100 — enough to cause significant problems for coastal cities as well as coastal airports.
Apart from that, while most airport terminal buildings have been built to withstand the physical impact of extremely strong winds, there have been cases of serious damage to the terminal buildings, such as in the case of Nanchang Changbei International Airport in China in March 2018, where the airport terminal’s roof was partially blown off by powerful winds running at a speed of 30 m/s.
Extreme weather conditions can also result to airport infrastructure such as landing lights, radar and navigation installations and communications networks. Flooding of airport terminals, emergency power installations and inter-terminal transport routes will also disrupt operations and shut down airports.
At this point, we have written much about extreme wet weather phenomena, but the impact of extreme heat from rising temperatures globally also affect airports operations.
In June 2017, dozens of flights at Arizona's Phoenix Sky Harbor airport were delayed or cancelled for two days after temperatures reached 120°F (48.9°C). The heat affected mainly flights on smaller aircraft, particularly flights on Bombardier CRJ planes. Larger planes made by Boeing and Airbus have maximum operating temperatures of 126 and 127 degrees respectively were less affected by the hot weather.
In an email from aircraft manufacturer Boeing to CNBC news over the issue, a Boeing spokesman explained that hotter air is less dense, which means there is less air beneath the wings for lifting the aircraft and less air to flow through the jet engines.
Just as in the case of rising sea levels, an increasing rise in the global temperature will also have a negative effect on airport operations.
In view of the current situation, new airports around the world are being constructed at higher levels while existing airports are building extensive engineering defences against floods.
For example, and as mentioned before, St. Paul Downtown Airport in Minnesota in the United States now has a portable flood wall it can erect in flash flood situations.
Officials at San Francisco International Airport are moving ahead with a US $587 million plan to build a major new sea wall around the entire airport. The runways, terminals and other buildings are protected now by a series of earthen berms and smaller sea walls that provide only 3 feet of protection from flooding. The airport plans to build an additional 5 feet of protection.
Japan's Land, Infrastructure, Transport and Tourism Ministry intends to raise the height of the runway and taxiways at Kansai International Airport. Along with work to increase the height of seawalls that block incoming high waves, construction will begin to elevate the 3,500 metre long, 60 metre wide runway by about 1 metre using asphalt.
New York LaGuardia Airport’s flood prevention measures include the construction of a flood wall and rainwater pumping system, and development of two gravity drainage systems on the airfield to advance removal of water in case of flooding
Singapore Changi Airport’s Terminal 5 is being constructed 5.5 metres above the mean sea level, which is higher than other areas in Singapore, to protect itself from flooding.
Terminal 5 of Singapore Changi Airport is to be constructed above sea level. (Photo from Today)
Meanwhile,as a response against extreme hot weather conditions, Phoenix Sky Harbor airport has built longer runways to accommodate flights on hot days.
Extreme weather phenomena has become more and more prevalent in recent years. Along with sea levels rapidly rising, this increases the vulnerability of airports in low-lying areas to much physical risk. Airports operators all around the world have to take measures to protect their assets as well as minimize their risks. The building of flood-prevention defences would naturally result in an increase in capital expenses, it but is a necessity.
Extreme Weather is becoming more common. (Image from NASA)
We just sent you an email. Please click the link in the email to confirm your subscription!