Climate change hits roads and airports in Nunavik

Take a piece of black paper and lay it on the ground for a while. When the sun shines, it won’t be long before you find a mucky mess underneath and the black paper slides away.

That’s the kind of impact that higher temperatures are having on the roads and runways of Nunavik, largely built above a layer of permafrost, or permanently frozen ground.

And this is why the Quebec transport department is scrambling to fix the damage – and avoid future problems – on airport access roads and runways which are buckling and splitting as permafrost melts under Nunavik’s ever-warmer temperatures.

Due to rising temperatures in Nunavik, a recent report from the Transport Department says melting permafrost is now “inevitable” and will become “a problem for all the transport infrastructure” in the region.

This, it says, could affect the “security and comfort” of users.

This summer, engineers from the department were in Salluit to test three different ways of lessening the impact of melting permafrost on the access road to the community’s airport. This access road is a steep, winding road, notorious for its snowdrifts, where melting permafrost is already beginning to cause damage.

“We thought we should test stabilization methods before applying them on a larger scale because they are very expensive. But it’s clear that Salluit is an urgent case,” said engineer and pavement specialist Guy Doré, who has been one of the lead consultants on the project.

“As soon as we can prove the efficiency of the techniques, we must apply them very rapidly because the Salluit’s road is suffering, and the runway is also affected.”

If nothing is done to the road, Salluit could see landslides or slippages, similar to the one that occurred there in 1998. This destabilized a neighbourbood of 20 new houses, which cost Quebec hundreds of thousands of dollars to move to new locations.

In Salluit, the average temperature of the permafrost has risen 1 C since 1988, while average air temperatures have undergone a “rapid heating” since 1992, an increase of 3.2 C in and 4.2 C in Inukjuak.

Runways in Kangirsuk and Tasiujaq also are experiencing problems, as well as those in Akulivik, Inukjuak, Puvirnituq and Umijuaq.

Next year, Doré and his team will work on cracks on Tasiujaq’s runway. In only a few years leading up to 2004, the permafrost melt in Tasiujaq increased by half a metre, nearly 50 per cent.

However permafrost damage on runways isn’t generally a safety issue.

“It’s not dangerous, as long as maintenance people correct the problems as soon as they occur. The big advantage of gravel runways is that they can be corrected when there are problems,” Doré said. “It would be worse if they were covered with asphalt.”

Paving is affected much more by melting permafrost, because pavement absorbs heat more than gravel surfaces. Several years ago, Nunavik began an ambitious $35 million paving program that will continue in the region until 2009.

Since paving was completed three years ago in Salluit, its visible problems with melting permafrost have been worsened.

“Although we understand why people in the communities want paving to eliminate some of the dust,” Doré said.

Engineers are looking at one way to reduce the negative impact of paving on Salluit’s access road, by painting a trial section with a reflective grey paint that reduces the amount of heat absorbed by paving.

You can see how this works yourself, by touching a paved road or dark surface on a sunny day, and feeling how much warmer that surface is than a nearby light-coloured surface.

Underneath and beside the access road in Salluit, engineers have also placed large stones to trap the cold and placed drains to create a current of frozen air which will help keep the ground frozen.

They’re testing these three techniques separately and together: “we want just to measure the way they work before we put them everywhere.”

About 10 locations along Nunavik’s 21 kilometres of airport access roads and on its 14 runways will need some intervention, Doré said. Of 12 runways visited in 2004, only two showed no signs of deformation due to permafrost melt.

And this number may increase as temperatures are expected to rise five to 10 C in Nunavik by 2100.