Simulating the possible ways global warming could impact landslides in the Austrian Alps

A team of researchers from Austria, Germany, Italy and the UK has created simulations aimed at showing possible landslide scenarios in the Austrian Alps in the coming years as global warming leads to changes in the weather there. Their paper has been published in the journal Communications Earth and Environment.

In June 2009, a three-day rain event over Austria led to flooding in northern parts of the country and multiple landslides in the southeast. The researchers note that in just one district, there were more than 3,000 landslides. The large number of landslides raised alarms throughout the country as some worried that such events may become more common under climate change. In this new effort, the researchers created simulations to show possible landslide scenarios in the coming years as the planet grows warmer.

As with most other recent simulation efforts, the researchers began with three major scenarios in mind—a worst case situation where the planet warms by 4 degrees Celsius, an intermediate situation where the planet warms by 3 degrees Celsius, and an optimistic situation where warming is held to just a 0.5 degrees Celsius increase. But they also tried account for other factors such as the impact of warmer air in the region where the prior landslides had occurred. They noted that more rain would obviously mean more landslides, and that they would likely occur over a larger part of the area under study. But they also noted that if rainfall amounts remained the same as today, or decreased, there could be fewer landslides because warmer air would lead to more evaporation of moisture from the soil.

The simulations showed that in the worst-case scenario, more rainfall could occur over a wider area—one 45% larger than the area impacted in 2009. But it also showed that drier air could result in fewer landslides or they could occur in a smaller area. Under intermediate conditions, the simulations showed more rainfall events that impact a smaller area, resulting in overall drier soil, suggesting fewer landslides. And under the most optimistic scenario, the simulations showed conditions similar to those of today.

The researchers also noted that changes in vegetation could have a big impact on landslides—planting lots of deep-rooted trees, for example, could dramatically reduce the number, size and frequency of landslides.