26 Mar Defending the world’s busiest airports against climate change
The world’s busiest airports are often situated near major cities and almost every major city is on the coast or close to a river delta. The World Bank estimates that around 350 million people live less than 5 meter above sea level, and a recent study has found that half of the world’s population lives closer than 3 km to a surface freshwater body.
This makes airports incredibly vulnerable to the effects of climate change, and particularly, flooding. Increasing urbanisation reduces natural water buffering potential in surrounding areas and reduces resilience.
Impact of airport closure
In 2011, extreme rainfall caused flooding at Don Muang airport in Bangkok which was so severe that it took a year to carry out extensive repairs and replace damaged electrical and IT systems. During this period, all flights had to be diverted to Suvarnabhumi Airport.
Other examples may be found after the passing of hurricanes such as Katrina in New Orleans and Sandy in New York, effectively shutting down airport operations leading to loss of critical assets and hampering emergency response efforts.
The closure of any airport has a considerable economic and operational impact but also a reputational one. When an international airport is inaccessible, so is, in many ways, the country it services. Whilst a storm passes within a few hours, it can take weeks, months or even longer to rebuild and resume normal operations.
You might think that the enormous potential cost and operational disruption would lead authorities to ensure their airports are well defended. Sadly, many aviation hubs remain worryingly unprepared.
Today, the average airport is built on legacy infrastructure with gradual expansion cycles. In most cases, drainage systems were never designed to cope with the increase in extreme rainfall intensities we now expect, so the threat of extreme weather events poses a very real concern. The situation is made more acute when the airport is located in a heavily urbanised area or flood plain. Other airports were built near the coast or on reclaimed land making them particularly vulnerable to the effects of sea level rise and storm surges.
Each world region faces particular challenges. For example in South East Asia rainfall already reaches high intensities. Here, the projected change in a weather event can create extreme amounts of water very quickly: 195mm of rainfall in an hour across the large surface area of a typical international airport creates the same water volumes as 870 Olympic swimming pools which has to be discharged and in some cases buffered on-site.
Thankfully some airport hubs have recognised the need for action and are now taking important steps to plan ahead and increase their resilience to this threat. In recent years, we have been working closely with amongst others Amsterdam Airport Schiphol and the Civil Aviation Authority of Singapore to identify in detail how climate change could impact assets and operations by carrying out scenario based risk assessments and mapping potential vulnerabilities.
Successful projects in an airport environment require stakeholder engagement. Working together with users and government authorities often results in interesting win-win possibilities where mutually beneficial pathways exist.
While doing so we strive to come up with effective proposals that are cost effective and protect only where needed, looking for added value such as the potential for rain water harvesting and working with water to create pleasant spaces for passengers and staff.
As a result of this work, we have identified three layers that need consideration:
- Flood prevention: creating large-scale water defences. Here, we seek to protect the entire airport perimeter, via levees, tidal gates, detention ponds and pumping stations to manage large volumes of floodwater.
- Minimising flooding effects: identifying the most essential assets to airport operations and ensuring they’re protected. This could mean moving IT servers to first floor locations, ensuring back-up generators are located above flood level and erecting flood barriers around essential structures. Vulnerable areas identified during the risk assessment feed into the airport master plan to avoid unnecessary exposure for new projects.
- Crisis Management: to ensure there are robust and well-established processes in place to cope with unexpected weather event.
Combining climate insights with drainage infrastructure and airport expertise
NACO is well placed to assist airport operators prepare for a resilient future.
Over 65 years of dedication to integrated and multi-disciplinary airport planning with projects in over 600 airports in over 100 countries ensures we know about airports and understand that each airport is unique, with its own particular challenges and possibilities. We work with our clients to solve the increasing complexities that come with developing world-class, future-proof airport.
NACO is part of Royal HaskoningDHV, an independent engineering consultancy with a long track record in water management. The Netherlands, with a quarter of its population living below sea level, has relied for centuries on its engineers to keep dry feet. Amsterdam Schiphol Airport itself is located approximately 6 meter below sea level. That is why our experts are closely involved in water management all over the world and our Water Vision Schiphol 2030 was included in the UNFCCC Private Sector Initiative data-base of adaptation actions.
Our experts create detailed assessments and studies of the potential impact of climate change on airport infrastructure and operations based on IPCC AR5 climate change projections or national climate studies – looking at rising sea levels, local rainfall patterns, wind phenomena, and air temperature.
This way we assist airports in mapping potential vulnerabilities and proposing widely supported solutions before risks materialise, protecting critical assets and ensuring operational continuity now and in the future.