A new global dataset, published in the journal Natural Hazards and Earth System Sciences, reveals that, excluding those caused by earthquakes, landslides were responsible for nearly 56,000 deaths between January 2004 and December 2016.
The majority of the 4862 accountable landslides were triggered by rainfall. However, the researchers, led by Melanie Froude from the University of Sheffield in the UK, also identified over 700 events which had a human fingerprint.
More worryingly, the temporal pattern of these landslides over the 13-year period suggests that the number of human-induced landslides is increasing.
“We were aware that humans are placing increasing pressure on their local environment, but it was surprising to find [these] clear trends,” says Froude.
The study was initiated by co-author and Sheffield’s vice-president for research and innovation, Dave Petley, who realised that many natural disaster databases were “significantly underestimating the extent of landslide impact”.
The human-triggered landslides were caused mainly by construction, illegal mining and hill-cutting, and while the trend was global, most of the recorded landslides occurred in Asia.
“With appropriate regulation to guide engineering design, education and enforcement of regulation by specialist inspectors, landslides triggered by construction, mining and hill cutting are entirely preventable,” says Froude.
Unfortunately, it isn’t quite that simple. The compilation also showed that fatal landslides occurred more frequently in poor countries and were more common in rural locations, such as the Himalayan mountainous region.
Froude explains, “in the case of roads [in the rural Himalayas], maintaining safety during construction is difficult when it is economically unviable to completely shut roads because alternative routes involve substantial detours.”
Regardless, Petley concludes: “the study highlights that we need to refocus our efforts globally on preventable slope accidents”.