Stabilising Slopes with Vegetation

"It’s widely, if largely anecdotally, accepted that slopes where plants grow – whether that’s grass, bushes or trees – are less likely to be damaged by natural hazards," said Professor Knappett. "By studying the soil-root interactions and assigning properties to the slope stabilisation effects of plant roots, vegetation will be able to be used as an engineering tool during the construction, stabilisation or repair of slopes."

Working with the James Hutton Institute in Invergowrie, Professor Knappett has found that vegetation can prevent earthquake damage to smaller slopes and can also reduce the damage to larger slopes. "Also, reinforcing a slope with vegetation is a low-cost, low-carbon neutral alternative to conventional methods such as installing a retaining wall or piles," he added.

At the moment, Professor Knappett and Professor Bengough are looking at how vegetation can help when a slope is hit by an extreme storm - something which will become increasingly likely with climate change. "As with our slope vegetation and earthquake research, we’re able to investigate this by using the University’s centrifuge, one of only two in the UK which can undertake earthquake simulation."

"Thanks to the centrifuge, we can build a scale model of a vegetated slope and quickly, efficiently and economically find out how a specific slope behaves under normal conditions and in the full force of storm, with and without vegetation."