Scotland

Tree planting 'could protect railways' from landslips

Train trapped in landslide Image copyright ScotRail Alliance
Image caption A landslide on the West Highland Line near Glenfinnan caused a train to derail on Monday. No one was hurt.

The forestry organisation Confor says we need to think seriously about using trees to protect infrastructure from the effects of extreme weather.

The call came as engineers finally freed a train from mud near Glenfinnan after it ploughed into a landslide on Monday.

A slip also closed the main Glasgow to Edinburgh line for a time, causing significant disruption to commuters.

Foresters say the government should look to Austria and Switzerland, where trees are commonly used to protect roads, railways and towns.

Landslips are usually caused by rain which saturates the land, making it too weak to hold.

Andrew Heald, technical director at the Confederation of Forest Industries (Confor), said: "It's about reducing run off of water at these sites and providing greater strength to the soil and greater stability.

'No guarantee'

"It's no guarantee but it is widely used in other parts of Europe. For example, in Switzerland about half the forests are managed as what they call 'protection forests' to protect the infrastructure and the towns and villages.

"It's about looking at our landscapes and getting the right trees in the right place, and managing them in the right way."

There are areas of Scotland which have been battling with landslips for many years.

Image copyright ScotRail
Image caption The main Glasgow to Edinburgh line was also closed earlier this week

At the Rest and Be Thankful in Argyll, landslips have become so frequent that engineers reinstated an old military road to act as a bypass when they occur.

Part of the Aberdeenshire coastal village of Gardenstown has been cut off for several weeks because of a slip.

A landslide at Bervie Braes in Stonehaven in 2010 forced the evacuation of 65 homes.

Scientists at the Met Office believe the impact of climate change will see incidences increase.

'Warmest decade'

Mike Kendon, from its National Climate Information Centre, said: "The latest decade has been the warmest decade in that long term series.

"A warmer atmosphere has the potential to hold more moisture, so we have also seen an increase in rainfall in Scotland.

"There are flood rich and floor poor periods throughout the historical record but nonetheless we have seen a clustering of flood events and extreme rainfall events in the most recent decade and that is consistent with our understand of our climate and how we anticipate it to change in the future."

Annual rainfall has increased in recent years by about 6%, according to Met Office data.

The winters of 2013/14 and 2015/16 were the wettest in Scotland since records began in 1910.

Network Rail has been reviewing its processes for dealing with flooding and landslips, using aerial surveys and satellite imagery to identify unstable slopes.

They have also been using acoustic monitoring to give an early warning of movement in the land.

Scottish Land and Estates, which represents many landowners, said planting trees on slopes would not be a commercially viable option for the land and that it would be up to governments to finance it.

But Green MSP Andy Wightman thinks nature provides a better answer.

He said: "On those slopes the trees are already there. They're only about an inch high and what's stopping them growing, and the ecosystem recovering, is the grazing pressure of either wild red deer or sheep and we could regulate both through law and incentives.

"It wouldn't matter in many areas but {it would} particularly in the west of Scotland, where you have very high levels of rainfall and very bare slopes.

"I think this is long past time we took much more serious action."

A Scottish government spokeswoman said: "We recognise that well designed and appropriately sited trees and woodlands can play an important part in managing sensitive sites, such as those affected by flooding.

"The Scottish government is committed to supporting sustainable woodland creation and seeing a thriving forest sector, and is proposing to increase the level of funding for woodland creation grants in 2018 -19 to £40m."

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