Power and Communication Outages Hamper Assessment of Landslides

More than a foot of rain turned major roadways in cities in the southeastern United States like Asheville, North Carolina, and Atlanta into floodplains Friday when already saturated soils were overwhelmed by the torrential bands of Helene.

Rain from the storm also caused trees, rocks and channels of mud to slide down steep slopes, covering roads and making portions of highways impassable, according to images and videos on social media. But the number and severity of mudslides have been difficult to assess in many places.

“I know we had many in our mountains but right now communication is really poor,” Bradley Panovich, chief meteorologist for WCNC Charlotte, said in an email. With emergency personnel engaged in rescue efforts and many areas cut off, the extent of the disasters remained unclear Friday in much of North Carolina, he said.

Philip Prince, a geologist for an Asheville-based company called Appalachian Landslide Consultants, said he expected reports of damage to emerge soon.

“Travel is still so bad that widespread surveying isn’t possible yet,” Prince said. “Given rainfall amounts prior to the storm and the final pulse of rain from the passage of Helene itself, there will be widespread land-sliding.”

Before the storm’s arrival, the National Weather Service warned of “significant landslide events” that could be set off by “historic, catastrophic and life-threatening” flooding.

Landslide risk has been increasing as the world warms.

“We can say for certain that we’re seeing more landslides occurring because of the effects of climate change,” said Dave Petley, a landslide expert at the University of Hull in England.

Climate change, largely caused by the burning of fossil fuels, leads to warming temperatures that increase moisture in the atmosphere and contribute to more intense rain. On Wednesday, at least 8 inches of rain fell in Asheville, and flooding inundated the town of 93,000 people. Helene brought more rain.

“The big concern is debris flows,” Prince said. That type of landslide contains fast-moving mud that can flow up to 50 mph while pushing rocks and trees downhill. “It’s the principal hazard to life during a storm like this.”

Brad Johnson, an environmental science professor at Davidson College, near Charlotte, North Carolina, said that at least 6 inches of rain had fallen in the past two days and strong winds had downed trees at his home.

Back in 2004, Hurricanes Francis and Ivan hit less than a week apart, bringing wind and rain to North Carolina, saturating soils and causing a landslide that destroyed 15 houses and killed five people.

At the time, the state created a Landslide Hazard Mapping Team to assess risks across North Carolina. The team got to only four counties before being disbanded, Johnson said.

“Politics came in,” he said. “Developers in the mountains pushed back about people being fully informed of their risks.”

Building impervious surfaces such as roads and constructing houses on steep slopes makes land more vulnerable to shifting under the force of a rainstorm.

But in places where landslide risk is significant — and in the United States, where landslide insurance is rare — developers and homeowners have resisted the creation of hazard maps, which could lead to more zoning regulations and potentially lower property values.

“I would like to be wrong,” Prince said, “but I anticipate some hard days ahead for western North Carolina.”

This article originally appeared in The New York Times .