Landslide Maps as a Life-Saving Tool - using Helene-triggered landslides to increase understanding and awareness

On September 26-27, 2024, a Predecessor Rainfall Event, followed by the remnants of Hurricane Helene, passed over the southern Appalachians. Heavy rainfall was concentrated along the high peaks of the Blue Ridge Escarpment and other high-elevation ranges in western North Carolina (WNC). After the storm passed and communications began to be reestablished, geologists with Appalachian Landslide Consultants, PLLC (ALC) began responding to requests for landslide evaluations in WNC. Through these requests from the NC Geological Survey, county Emergency Management, the NC Department of Transportation, as well as private individuals, geologists began to collect empirical observations from the dozens of slope movements visited. The majority of these are classified as debris flows, debris blowouts, or debris or weathered rock slides. These features occur on non-constructed slopes, as well as on constructed cut or fill embankment slopes. Surface and groundwater played a large role in their initiation, as observed by surface overwash and erosion patterns as well as groundwater “macropore” features. Several of these features occurred where landslides have happened in the past, once again reminding us that past events may inform where future events may occur. Many occurred within modeled landslide susceptibility areas.

Bauer (2025) Landslide Maps as a Life-Saving Tool - using Helene-triggered landslides to increase understanding and awareness, USGS Landslide Hazards Seminar, 30 April 2025