Safe airports with climate risk assessments
It’s a key sector for which the potential impacts of climate change could be particularly challenging. A methodology to define the level of climate risk on airport infrastructures in the Mediterranean regions published in a study in Natural Hazards realized with the contribution of the CMCC Foundation.
The aviation sector has long been criticized for contributing to the causes of climate change through greenhouse gas emissions, but the need for aviation to adapt to the consequences of climate change has not been well researched or considered and the methodologies for risk assessment and the definition of targeted adaptation strategies are still limited.
Nevertheless, the impacts of climate change on the aviation sector are well known. According to the “Challenges of Growth 2013” report, published by the European Organization for the Safety of Air Navigation (called Eurocontrol), the key risks of climate change for the European aviation sector are due to temperature increases, extreme precipitations, changes to storm and wind patterns, sea level rise and storm surges (Eurocontrol 2013). In addition, although the impacts on European airports differ according to the geographical area, climate zones and local circumstances, the greatest risks are expected in central and southern Europe. More specifically, Mediterranean airports face risks associated with sea level rise, higher occurrence of extreme temperature and precipitation events.
A study recently published on Natural Hazards (among the authors, Marta Ellena, CMCC scientist at REMHI – Regional Models and Geo-Hydrological Impacts Division, and Paola Mercogliano, REMHI Division Director) presents the theoretical frameworks for risk assessment related to extreme temperatures, extreme precipitations and sea level rise with a focus on Mediterranean airports while identifying the sources of climate risk that may induce potential impacts on airports, here divided in air side and land side components. In order to do so, the researchers select a series of indicators used as proxies for identifying hazard, exposure and vulnerability. The application of these theoretical frameworks allows defining the level of risk associated with each hazard, with the goal to support the identification of specific adaptation measures for the Mediterranean airports.
“The illustrated methodology represents one of the first attempts to quantify risks in the airport environment”, Paola Mercogliano explains, “and proposes an approach with the goal to define a specific risk for each hazard considered. The findings reveal that airports located in the Mediterranean regions will mainly have to face the risks associated with these climatic hazards. However, it is possible to replicate the application of these frameworks in other geographical contexts affected by the same risks.”
The method proposed here therefore aims to support stakeholders in conducting risk analyses in order to identify suitable adaptation strategies. Based on the state-of-the-art literature, the theoretical frameworks were constructed through the identification of specific indicators of hazard, exposure and vulnerability.
More in detail, in Framework 1 – Climate risk due to extreme temperatures (in Fig. 2 of the article), the selected climate indices are based on temperature thresholds that may damage runway surfaces, aprons, taxiways, parking areas or that may cause an interruption of airport activities. Additionally, extreme temperatures cause more pressure on local services, e.g., water and electricity for building cooling, and technical problems with radars for air traffic control. Based on these main vulnerabilities for airports reported in the literature, researchers chose the sensitivity indicators.
In Framework 2 – Climate risk due to extreme precipitations (in Fig. 3), the climatic indicators were chosen based on precipitation thresholds that determine high impacts on airport components.
Extreme rainfall events could compromise the drainage capacity of the airport, with an increase in flooding. There are several factors that leave an airport more vulnerable to extreme rainfall: the presence of underground infrastructures such as parking or various access areas, which are more likely to suffer from flooding; the presence of impermeable surfaces as they reduce the potential for water infiltration of the soil, thus increasing the risk of flooding caused by greater runoff.
In Framework 3 – Climate risk due to sea level rise (in Fig. 4), sea level rise (SLR) and storm surge level (SSL) indicators were selected to describe the coastal flooding. Many airports are built along the coasts or in floodplains to facilitate take-off and landing, but these areas are more exposed to sea level rise and storm surges. Coastal flooding, as well as flooding from heavy precipitation, can affect runways, parking areas and other airport surfaces, damage buildings or other structures.
The study highlights also those solutions that should be at the basis of efficient adaptation strategies to face these impacts.
To cope with thermal damages due to extreme temperature events, runways, taxiways and other structures should be resurfaced with heat resistant materials. In areas where higher temperatures can pose a challenge to aircraft take-offs, adaptation measures include building longer runways or performing intercontinental flights in the evening when temperatures drop. Moreover, the installation of roofs and walls with vegetation on airport structures are excellent green measures to mitigate the effects of extreme temperatures, to save energy and to reduce the flow of rainwater. Additional benefits obtained include a reduction in noise, an improvement in air quality and in the aesthetics of the building as well as other social, environmental and economic benefits.
To cope with floods, airports need to implement adaptation strategies, which mainly concern the construction of efficient drainage systems as well as the development of adequate warning systems.
To contain the risk associated with coastal flooding, many airports, especially in northern Europe, have implemented grey adaptation strategies such as the construction of coastal barriers, higher runways and very efficient drainage systems. Other adaptation measures common to all three frameworks are the adhesion of airports to adaptation initiatives aimed at acquiring greater awareness of the risk of climate change impacts and adherence to insurance policies for extreme events, introducing tools for effective management of damages and losses.
“The next step of this work, performed in the framework of a Phd in collaboration with Parthenope University of Naples, is the application of the proposed methodology to specific case studies”, Paola Mercogliano concludes. “More specifically, we are planning to include the application of these frameworks to the Italian airports most exposed to the climatic hazards examined, almost completely devoid of suitable adaptation strategies to climate risk.”