What causes landslides and debris flows?
Landslides are caused by disturbances in the natural stability of a slope. They can accompany heavy rains or follow droughts, earthquakes, or volcanic eruptions. Mudslides develop when water rapidly accumulates in the ground and results in a surge of water-saturated rock, earth, and debris. Mudslides usually start on steep slopes and can be activated by natural disasters. Areas where wildfires or human modification of the land have destroyed vegetation on slopes are particularly vulnerable to landslides during and after heavy rains. What are the health threats from landslides and debris flows? In the United States, landslides and debris flows result in 25 to 50 deaths each year. The health hazards associated with landslides and mudflows include: • Rapidly moving water and debris that can lead to trauma; • Broken electrical, water, gas, and sewage lines that can result in injury or illness; and • Disrupted roadways and railways that can endanger motorists and disrupt transport and acces
