Skip to main content

What Causes Mudslides?

Mudslides

Mudslides can occur at any time of the year, regardless of weather conditions, according to the Federal Emergency Management Agency (FEMA). And they can strike without any prior warning signs, making for a dangerous phenomenon.

"Mudslides occur in all 50 U.S. states and can happen at any time – with or without rainfall," said Lynn Highland, a geographer at the USGS National Landslide Center.

Earthquakes, volcanic eruptions, changes in groundwater levels, alternate freezing and thawing, and the steepening of slopes by erosion all contribute to mudslides.

Construction and reckless modification of land – such as not draining an area properly before building on or near it – can also create the conditions ripe for a mudslide, Highland said.

She added, that prolonged, intense precipitation and run-off can contribute to landslides, as can wildfires. Fires lead to mudslides because burning can kill the plant's roots. Roots hold soil together, stabilizing the land and making it less likely to be swept away, according to Highland. In this way, overgrazing can also contribute to mudslides.

Because different areas of land have different soil compositions, as well as varying slopes and geographic characteristics, it is difficult to determine how prone a place is to mudslides and therefore near impossible to predict when one will hit – although they are known to occur in areas previously hit by mudslides, according to the USGS.

"The West Coast is especially susceptible to mudslides because of the earthquakes, rainfall, and wildfires that happen in that region," Highland told Life's Little Mysteries. "In California, there is a 'mudslide season' lasting from December to April, during which time the rainfall is fairly predictable."

Because California wildfires leave behind charred slopes, the region is especially susceptible to mudslides during and immediately after major rainstorms. However, sometimes damage caused by a mudslide can take days or even weeks to surface.

An example of this 'delayed triggering' of deeper landslides occurred in Los Angeles, Calif., in 1998, when mudslides forced the evacuation of more than 100 people and destroyed several houses five days after the rain had stopped, according to the California Geological Survey (CGS).

More than 100 Californians have been killed by land and mudslides during the last 25 years, according to the CGS. Most of these deaths were due to people being buried by debris flows as they slept in lower-floor bedrooms that were near hazardous slopes.
… read more

Comments

Anonymous said…
Undue erosion and sedimentation from land disturbing dealings have been linked to serious land and water management issues, which are a large concern to the county residents. Of course, one of the most common ways to prevent erosion is to plant vegetation. Plants act as protective shields that can lessen the impact of rainfall that can loosen the soil. Good water drainage also helps lessen erosion because it diverts excessive watering.

Monica Barnes

October 10, 2012 at 11:12 AM
Post a Comment

Popular posts from this blog

Erosion Control, and Nanotechnologies (NT)

Erosion Control Forum – Information on erosion control devices and resources Skip to content Abstract Nanotechnology (NT) The National Nanotechnology Initiative defines nanotechnology as understanding and controlling matter at dimensions between approximately 1 and 100 nanometers, where unique phenomena enable novel applications. Introduction Nanotechnology offers the potential to effectively treat contaminants in situ, avoiding excavation or the need to pump contaminated water out of the ground. The process begins with nanoparticles being injected into a contaminated aquifer via an injection well. Role of Nanotechnology Nanotechnology plays a crucial role in improving wind turbine performance...
2 comments
Read more

Environmental Issues

Erosion Control Forum – Information on erosion control devices and resources Skip to content Bioventing Description Bioventing is an in situ remediation technology that uses microorganisms to biodegrade organic constituents adsorbed on soils in the unsaturated zone. Bioventing enhances the activity of indigenous bacteria and simulates the natural in situ biodegradation of hydrocarbons in soil by inducing air or oxygen flow into the unsaturated zone and, if necessary, by adding nutrients. During bioventing, oxygen may be supplied through direct air injection into residual contamination in soil. Bioventing primarily assists in the degradation of adsorbed fuel residuals, but also assists in the degradation of volatile organic compounds (VOCs) as vapors move slowly through biologically active...
1 comment
Read more

Geogrid

Erosion Control Forum – Information on erosion control devices and resources Skip to content A geogrid is geosynthetic material used to reinforce soils and similar materials. Soils pull apart under tension. Compared to soil, geogrids are strong in tension. This fact allows them to transfer forces to a larger area of soil than would otherwise be the case.[citation needed]. Geogrids are commonly made of polymer materials, such as polyester, polyvinyl alcohol, polyethylene or polypropylene. They may be woven or knitted from yarns, heat-welded from strips of material, or produced by punching a regular pattern of holes in sheets of material, then stretched into a grid.Geogrid is typically used for soil reinforcement applications such as retaining walls, steepened slopes, embankments, sub-grade stabilization, embankments over soft ...
Post a Comment
Read more