The smart use of water can help keep runways cool, a world-first heat mitigation trial at Adelaide Airport has found.
The trial, which was conducted by SA Water and Adelaide Airport over three years, revealed that using water to maintain soil moisture and cultivate green space could potentially lower ambient temperatures by more than 3 degrees celsius.
Recycled water from SA Water’s re-use scheme was applied to 4 hectares of lucerne hay 600 m south of the airport’s runway, twice a week at night, to create the cooling effect.
In warmer, less dense air, planes need to travel faster down the runway to produce the lift needed for takeoff. When a runway isn’t long enough for an aircraft to reach these speeds, the plane’s weight must be lowered or it needs to use more fuel.
SA Water Manager of Environmental Opportunities Greg Ingleton said the cooling method could lead to a reduction of the airport’s carbon footprint and be used to improve the liveability of cities around the world.
“The extensive hard surfaces and cleared land around airports means they can often become sources of increased heat, which impacts both terminal and airside operations,” Ingleton said.
“Two years ago, in Arizona in the United States, 50 flights were cancelled in one day due to it being too hot for the planes to take off.”
The trial also showed the benefits of using space around airports to produce revenue-generating food crops.
Ingleton said an economic analysis, based on an expansion of the area to 200 hectares, suggested initiatives like this could provide a range of operational efficiencies and wider benefits for airports.
Representatives from SA Water and Adelaide Airport shared these insights at an aviation industry conference in Abu Dhabi last month. Ingleton said the aim was to share knowledge with other businesses around the world.
“Expanding our exposure and experience to diverse climates and landscapes will also enhance our capability right here in South Australia, and help implement heat mitigation in a range of other urban environments, such as schools and council parks, to improve liveability,” he said.
“By supporting green infrastructure and the intelligent use of water, we can cool urban areas and reduce the impact of heatwaves and climate change.”