During a landslide (also known as a landslip or mudslide), water-saturated masses of rock, earth, and debris move down a destabilized slope, having the ability to cause service disruptions, damage to property and agriculture, human injuries, and in severe cases, death. Landslides have various causes including earthquakes, storms, volcanic eruptions, fires, and human modifications to land. Landslides develop when water rapidly accumulates on the ground, particularly during heavy rainfall or rapid snowmelts, converting the earth into a flowing river of mud. Landslides can occur quickly, often with little or no warning, and can travel several miles from their source as they grow in size by picking up various large and small debris. Areas particularly close to mountains, canyons, and/or a coastal regions, as well as those areas with a lower threshold of precipitation, may be more prone to landslides.
How do I prepare?
Learn risks: ask your local emergency management office if your property is in a “landslide-prone” area.
Inspect: look around your home and property for landslide warning signs:
- cracks or bumps on hill slopes, ground, or roads
- water or saturated ground in areas not normally wet
- evidence of slow, downhill movement of rock and soil
- tilted trees, poles, decks, patios, fences, or walls
- doors or windows stick or cracks appear on walls
Reduce risks: plant ground cover on slopes and build retaining walls.
Be aware: areas hit by wildfires have an increased risk of landslides and mudflows once the rainy season starts.
Be prepared to evacuate: listen to local authorities and leave if you are told to evacuate. Decide in advance where you would go in case you can’t return home for any period of time.
The best way to prepare for a landslide is to stay informed about the changes in your community and around your home that could signal a landslide may likely occur. Community land-use zoning and proper design and professional inspection of land uses may mitigate the effects and likelihood of a landslides.
Local and National Government
Vulnerability to landslides depends on location, modification of land due to human activity, and the frequency at which landslides occur in the area. While all landslides are not preventable, the effects of landslides on people and structures can be lessened. By restricting, prohibiting, and/or imposing conditions on areas deemed a hazard-zone, a community could reduce the risk. For example, local governments can reduce the effects of a landslide by developing proper land-use policies and regulations. Additionally, local governments may consider obtaining professional services of an engineering geologist, a geotechnical engineer, or a civil engineer, if one is not currently on staff, who can properly evaluate the hazard potential of a site, built or unbuilt. Overall, the effects of a landslide can be reduced by avoiding construction on steep slopes or slopes previously effected by a landslide, investing in stabling slopes in the community, and being mindful of where water runoff is being directed. [Source: USGS]
- Contact local authorities to inquire about possible risks and historical data on the community landslides
- Be aware that communities hit by wildfires have an increased risk of landslides if heavy rain follows
- Look around property for vulnerabilities (cracks or bumps on hill slopes, ground or roads; tilted trees, poles, fences or walls)
Get equipped and be prepared to evacuate
- Decide in advance where you will evacuate to, this includes temporary and/or permanent designated alternative sites
Reduce risk near the workplace
- Plant ground cover on slopes and build retaining walls, if applicable
Additionally, consider creating a or revising your current workplace's Business Continuity Program.
What do I need to know?
Landslides can occur quickly, often with little notice. Therefore, the best way to prepare is to stay informed about changes in and around your home and community that could signal that a landslide is likely to occur. While some geographic locations may be more prone to landslides than others, landslides can occur anywhere with unstable ground, especially where land has been modified. Some areas more likely to experience landslides or mudflows where extra precautions and observance should occur include areas where wildfires have destroyed vegetation, areas where landslides have occurred before, steep slopes and areas at the bottoms of slopes and canyons, areas along a stream or river, and areas where water runoff is directed. [Source: CDC]