Landslides in Western North Carolina

Landslide points identify the initiation (source) areas of slope movements. Attributes of this layer include descriptions of slope movement type, location, dimensions, movement dates, and geomorphic, hydrologic, and other site data for individual slope movements, where known.

Landslide Outlines show the approximate areal extents of relatively recent, individual slope movements where their initiation (source) areas are known. Outlines were determined from field investigations, features visible in various vintages (1940–most current) of aerial photography and orthophotography, and a variety of digital maps derived from LiDAR digital elevation models.

Landslide Deposits represent the areal extents of significant volumes of earth, debris, and rock fragments that have accumulated primarily because of past debris flows and debris slides and, to a lesser extent, rock falls and rockslides. These deposits indicate areas that can be affected by future landslides and can be unstable in some circumstances. Debris flow deposits mainly occur in valleys and can transition upslope into debris slide, rock fall, and rockslide deposits nearer steep source areas.

The Potential Debris Flow Pathways layer shows where landslides might go if a slope movement occurs from a high landslide susceptibility area. Changes in the landscape as a result from human activity, future debris flows, and other types of landslides can alter the potential pathways of subsequent debris flows; therefore, this data represents general areas that could potentially be affected by future landslide impacts.

This layer shows areas where debris flows and debris slides might start on unmodified slopes. Landslides happen under specific conditions; therefore, the likelihood of occurrence is relatively small. Debris flows and debris slides originating on unmodified slopes become more frequent in Western North Carolina when precipitation is 5 inches or more in a 24-hour period. Be aware of High and Moderate Probability of Sliding areas during extreme precipitation events. Use caution when modifying High and Moderate slopes because they may be unstable with or without extreme rain events.