Changes in Hydrologic Characteristics – heavy rains can saturate regolith reducing grain to grain contact and reducing the angle of repose, thus triggering a mass movement. ... Changes in the groundwater system can increase or decrease fluid pressure in rock and also trigger mass movements.
Does water influence mass movement?
The Role of Water
Although water is not always directly involved as the transporting medium in mass movement processes, it does play an important role . Addition of water from rainfall or snow melt adds weight to the slope. Water can seep into the soil or rock and replace the air in the pore space or fractures.
How does water trigger mass movements?
How does water trigger mass movements? Water fills the pores in sediment , allowing the particles to slide past one another more easily. ... If the steepness of a slope exceeds that angle, mass movements become more likely.
What causes creep mass movement?
Creep is the imperceptibly slow, steady, downward movement of slope-forming soil or rock. Movement is caused by shear stress sufficient to produce permanent deformation , but too small to produce shear failure. ... Progressive, where slopes are reaching the point of failure as other types of mass movements.
What are the 5 types of mass movement?
- Rockfall. Bits of rock fall off the cliff face, usually due to freeze-thaw weathering.
- Mudflow. Saturated soil (soil filled with water) flows down a slope.
- Landslide. Large blocks of rock slide downhill.
- Rotational slip. Saturated soil slumps down a curved surface.
What is the difference between a rockslide and debris flow?
A rockslide is the sliding of rock material down a mountain. ... A debris flow is the movement of a water-laden mass of loose mud, sand, soil, rock and debris down a slope . A debris flow can dash down the slope, reaching speeds of 100 miles per hour or greater.
How do humans affect mass movement?
Humans can contribute to mass wasting in a few different ways: Excavation of slope or its toe . Loading of slope or its crest. Drawdown (of reservoirs)
What factors influence the mass movement of particles?
Mass movement or mass wasting mainly occur in landslides and mudslides. Rain falling on a slope, water flowing downhill a region, large rocks and debris on a slope are factors which will influence the mass movement of particles.
Can mass wasting be prevented?
We cannot prevent mass wasting , however, in many situations there are actions we can take to reduce or mitigate the damaging effects of mass wasting on people and infrastructure. Where we can neither delay nor mitigate mass wasting, we may consider trying to initiate the slope failure in a controlled manner.
What prevents mass wasting?
Engineering solutions include barriers and retaining walls, drainage pipes , terracing the slope to reduce the steepness of the cuts, and immediate revegetation. Rockfalls can be controlled or eliminated by the use of rock bolts, cables, and screens and by cutting back slopes to lesser gradients.
What are four ways to prevent mass movements?
Mass movement control must be primarily preventive: e.g., mapping vulnerable zones, drawing up a land use plan, banning building work or any modification of slopes, and protection in the form of coppice forests.
What is the slowest type of mass movement?
The slowest and least noticeable, but most widespread of the slow mass wasting categories is creep . Creep involves the entire hillside, and is characterized by very slow movement of soil or rock material over a period of several years.
Is Solifluction a mass movement?
Solifluction. ...a major type of mass movement in cold polar regions and some high mountains . Solifluction is a special type of creep that occurs in areas of permafrost. Permafrost refers to the layer of groundwater that fills in the pore spaces of soil and rock that is permanently frozen.
What are the 4 factors that influence mass movements?
Factors that change the potential of mass wasting include: change in slope angle, weakening of material by weathering, increased water content ; changes in vegetation cover, and overloading.
What is the difference between mass movement and erosion?
Definition: Erosion is the dislodging of sediments that initiates their movement. Particles may then be moved away by sediment transport agents such as wind, water, glaciers, etc. Mass movement refers to earth materials moving downslope under the influence of gravity, as in rockslides, mudflows, slumps, etc.
What is the difference between weathering and mass movement?
| WEATHERING MASS WASTING | It can be mechanical, chemical or biological. It can be rapid movements like rock falls or landslides or slower movements like erosion | It does not result in the occurence of any natural disaster. It can result in disaster like landslides. |
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