New map shows where landslides are most likely to occur in US

The U.S. Geological Survey has released a new nationwide landslide susceptibility map that indicates nearly 44% of the U.S. could potentially experience landslide activity. The new assessment provides a highly detailed, county-by-county picture of where these damaging, disruptive and potentially deadly geologic hazards are more likely as well as areas where landslide hazards are negligible.

The new map will support risk-reduction and land-use planning efforts by showing where potentially unstable areas are so planners and engineers can better prioritize and mitigate future landslide hazards. Details have been published in the journal AGU Advances.

“This new national landslide susceptibility map addresses an important but difficult question: which areas across the entire U.S. are prone to landslides?” said Ben Mirus, USGS research geologist. “We are excited that it is now publicly available to help everyone be more prepared—to be a more hazard-ready nation.”

Previously, detailed landslide maps were only developed for a few areas of the U.S. where the landslide risks were considered high, but this map expands the assessment to include many other hazardous areas around the country where there was a limited understanding of landslide potential.

Mirus and team used an inventory of nearly 1 million previous landslides, high-resolution national elevation data from the USGS 3D Elevation Program, and advanced computing to build their comprehensive landslide susceptibility model.

The resulting map of the contiguous U.S., Alaska, Hawaii, and Puerto Rico zeroes in on landslide locations by using much higher resolution data than existing continental and global landslide maps.

The new map can also be used to identify areas where more landslide mapping is needed and how the improvements can better inform landslide mitigation.