Mudslides occur in areas where the land has been destabilized by the removal of vegetation, often as a result of wildfires or human activities. Mudslides tend to occur when there is a steep slope and may reoccur in the same location. The most commonly affected states in the United States include California, Oregon, Washington, Alaska and Hawaii.
In a mudslide, soil becomes saturated by rain. Lack of vegetation leaves the soil without any roots to hold it together. If the slope is steep, when the soil reaches a certain point of saturation, it can act like a liquid, flowing down the slope. The soil picks up anything in its path, creating a slide of fast-moving debris that can create massive damage. Mudslides may be triggered by natural disasters but are also known to happen with no trigger other than prolonged rains.
Mudslides are hard to predict, but awareness of environmental conditions can help protect property and lives. Developing an evacuation plan can save lives. Geological surveys of suspect areas before building can indicate mudslide potential and affect decisions to build, saving property from future damage. Planting to establish a root system on steep slopes makes soil less vulnerable to destabilization and lessens the likelihood of a mudslide.