Seasonally wet periods—Heavy precipitation initiates landsliding, particularly in association with flood conditions. However, landslide is more likely to occur later in a wet when the cumulative seasonal precipitation has saturated the ground.
Where do landslides often occur?
Landslides occur in a variety of environments, characterized by either steep or gentle slope gradients, from mountain ranges to coastal cliffs or even underwater , in which case they are called submarine landslides.
How often do landslides occur?
Why Study Landslides? Landslides are a serious geologic hazard common to almost every State in the United States . It is estimated that in the United States, they cause in excess of $1 billion in damages and from about 25 to 50 deaths each year.
What weather conditions cause landslides?
Landslides can be triggered by rainfall , snowmelt, changes in water level, stream erosion, changes in ground water, earthquakes, volcanic activity, disturbance by human activities, or any combination of these factors.
What are 4 types of landslides?
Landslides are part of a more general erosion or surficial pro- cess known as mass wasting, which is simply the downslope movement of earth or surface materials due to gravity. They are classified into four main types: fall and toppling, slides (rotational and translational), flows and creep .
How can we prevent landslide?
There are also various direct methods of preventing landslides; these include modifying slope geometry , using chemical agents to reinforce slope material, installing structures such as piles and retaining walls, grouting rock joints and fissures, diverting debris pathways, and rerouting surface and underwater drainage.
How do landslides affect humans?
People affected by landslides can also have short- and long-term mental health effects due to loss of family, property, livestock or crops. Landslides can also greatly impact the health system and essential services , such as water, electricity or communication lines.
Can landslides be predicted?
To be able to predict landslides, scientists have developed slope stability models to analyze the risk locally . More recently, NASA has created a preliminary algorithm to map landslide hazards globally using satellite measurements of rainfall, land cover and other surface variables.
How do you know when a landslide is coming?
Landslide Warning Signs
Springs, seeps, or saturated ground in areas that have not typically been wet before. New cracks or unusual bulges in the ground, street pavements or sidewalks. Soil moving away from foundations . Ancillary structures such as decks and patios tilting and/or moving relative to the main house.
What are landslides caused by?
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.
What is landslide and its effects?
The impact of a landslide can be extensive, including loss of life, destruction of infrastructure, damage to land and loss of natural resources . Landslide material can also block rivers and increase the risk of floods. ... After Tropical Storm Stan in 2005, landslides caused the watersheds in Guatemala to collapse.
What are the causes and effects of landslides?
Factors that trigger landslide movement include heavy rainfall, erosion, poor construction practices, freezing and thawing, earthquake shaking, and volcanic eruptions . Landslides are typically associated with periods of heavy rainfall or rapid snowmelt and tend to worsen the effects of flooding.
What are the 2 types of landslides?
movements are included in the general term “landslide,” the more restrictive use of the term refers only to mass movements, where there is a distinct zone of weakness that separates the slide material from more stable underlying material. The two major types of slides are rotational slides and translational slides .
What are the most common landslides?
- Rock falls. Single and small rock falls from cliffs build up to form aprons of scree or talus, sometimes developing over long time periods. ...
- Rock slope failures. This group of landslides varies greatly in features. ...
- Rotational landslides. ...
- Debris flows. ...
- Creep. ...
- Solifluction. ...
- Translational slides.
What is the difference between a slump and a landslide?
Landslides involve rock and debris moving downslope along a planar surface, whereas slumping usually occurs along a curved interface and as a single large unit.
How can we prevent land erosion and landslide?
The most effective, natural way to control soil erosion on slopes is to plant vegetation . Not only will vegetation help to slow down raindrops as they fall, the roots of the plants will also help to hold the soil together, making it harder for water to wash it away.
