Landslide Hazards

Landslide hazard and risk assessments help people understand the dangers from landslides to their towns and cities, homes, facilities, and businesses. Landslide hazard assessments are estimates of the probability that landslides will affect a particular area or location, typically within a given timeframe.

We use remote-sensing technologies—such as aerial photography, satellite imagery, structure-from-motion (SfM) photogrammetry, and lidar (laser-based surveying)—to measure coastal change along U.S. shorelines.

This project characterizes and measures sediment-related effects of landscape disturbances (such as major storms, drought, or wildfire) and river management. We focus primarily on the U.S. west coast, and our work relates to natural hazards and resource management.

Coastal and marine geohazards are sudden and extreme events beneath the ocean that threaten coastal populations. Such underwater hazards include earthquakes, volcanic eruptions, landslides, and tsunamis.

On California’s Big Sur coast, the steep slopes at Mud Creek suffered a catastrophic collapse (May 20, 2017). On January 28, 2021, heavy rains from a two-day storm caused debris from fire-scarred slopes to wash out another section of road at Rat Creek. USGS scientists are monitoring this 100-mile section of the California coastline, in collaboration with the CA Department of Transportation.

On May 20, 2017, the steep slopes at Mud Creek on California’s Big Sur coast, about 140 miles south of San Francisco, suffered a catastrophic collapse. USGS scientists from the Pacific Coastal and Marine Science Center and the Geology, Minerals, Energy, and Geophysics Science Center continue to monitor this section of the coastline, in collaboration with the California Department of Transportation...

Earthquake-triggered ground-failure, such as landsliding and liquefaction, can contribute significantly to losses, but our current ability to accurately include them in earthquake hazard analyses is limited.

Although they are relatively uncommon, large catastrophic landslides move rapidly destroying everything in their paths. Such landslides are difficult to predict as shown by the following examples.

The most frequent and widespread damaging landslides in the U.S. are induced (started) by prolonged or heavy rainfall. The majority of rainfall-induced landslides are shallow (less than a few meters deep), small, and move rapidly. Many rainfall-induced landslides transform into debris flows (fast-moving slurries of water, soil, and rock) as they travel down steep slopes, especially those that...

Estimates of the probability and volume of debris flows that may be produced by a storm in a recently burned area, using a model with characteristics related to basin shape, burn severity, soil properties, and rainfall. Wildfire can significantly alter the hydrologic response of a watershed to the extent that even modest rainstorms can produce dangerous flash floods and debris flows. The USGS...

Click on the map to view monitoring site locations. Click on the marker for a link to each site.

A summary of recent and past landslides and debris flows caused by rainfall in northern California, and links to current shallow landslide monitoring.