Landslides are not individual events, they occur in conjunction with other factors. Landslides occur when a hill or mountain is unstable. Some of the factors that allow it to become unstable are erosion, addition of moisture, shocks and vibrations, and volcanic eruptions ("Why Do Landslides Happen?", 2011).
Humans can also have a big effect on landslides occurring. Activities such as construction, transportation, building dams and canals, and mining can disturb the earths materials. As more and more people overdevelop the land becomes less stable. Deforestation is another cause for landslides. Humans keep cutting down more trees, when this happens the land becomes more susceptible to heavy rains and floods which make landslides occur very easily (“Why Do Landslides Happen?”, 2011).
Even though landslides happen all the time in Western Oregon, the awareness of the hazards landslides can cause are very low. The Oregon legislature adopted Senate Bill 12 in an attempt to promote awareness of the dangers associated with landslides. The goal of Senate Bill 12 is to save lives and reduce future landslide losses. An important step towards achieving this goal is to use a digital hazard map that shows the locations that are at a high risk for rapidly moving landslides, which are landslides that move so fast they cannot be outrun. The map will be primarily used by emergency workers, transportation workers, foresters, ecologists, and property owners who can identify the hazard zones where the rapidly moving landslides might occur. Mudslides are one of the main
References: Hofmeister, R. J. (2002). Hazard Map of Potential Rapidly Moving Landslides in Western Oregon. Retrieved from http://www.coastalatlas.net/documents/IMS-22.pdf Why Do Landslides Happen?. (2011). Retrieved from http://www.geology.wisc.edu/courses/g115/projects03/emgoltz/causes.htm Mudslides wreak havoc in Oregon. (2011). Retrieved from http://www.upi.com/Top_News/US/2011/01/17/Mudslides-create-havoc-in-Oregon/UPI-48511295313804/