Badly built roads can generate more hazard than a significant earthquake, research shows. Hakan Tanyaş, from the University of Twente in the Netherlands, and colleagues monitored the size and number of landslips in the Arhavi area of north-eastern Turkey between 2010 and 2020. During this period several roads were constructed through the region to access a new hydroelectric scheme.
The scientists show that development had a shocking impact on the stability of the hillsides, with road construction responsible for more than 90% of the observed landslips in the region.
Their calculations, reported in the Natural Hazards journal, suggest the volume of debris created by these excess landslips is equivalent to the area being shaken by a magnitude 6 earthquake.
Because much of this sediment ends up in rivers, the scientists say it will change the way rivers flow and increase the probability and severity of flooding.
Writing in The Landslide Blog, Dave Petley from the University of Sheffield, says road-induced landslides are a global issue. “The sad element of this is that these landslides almost entirely avoidable – such road-related landslide impacts are down to poor engineering practice.
“Roads do not need to be built in this way, and there are plenty of examples of good practice from around the world.”
