Slopes 3.3

Question 1

Regolith

Answer 1

The layer of loose, unconsolidated material covering solid rock, including soil, weathered rock fragments, and sediments transported by wind, water, or ice.

Question 2

Aspect

Answer 2

The direction that a slope faces, which influences microclimatic conditions such as temperature and moisture availability, affecting vegetation growth and weathering rates.

Question 3

Mass movement

Answer 3

The downslope movement of soil, regolith, and rock under the influence of gravity, which can occur as slow processes (soil creep) or rapid movements (landslides, rockfalls).

Question 4

Shear Strength

Answer 4

The ability of soil or rock to resist shear stress, determined by factors such as cohesion, internal friction, and vegetation cover. It influences slope stability.

Question 5

Shear Stress

Answer 5

The force attempting to pull the mass downsloap, mainly influenced by gravity, water content, and slope angle.Critical angle 30-40%

Question 6

Rain Splash

Answer 6

A form of soil erosion caused by raindrops hitting the ground, dislodging soil particles and redistributing them.

Question 7

Sheetwash

Answer 7

A type of surface erosion in which thin, non-channelized layers of water flow over the ground, transporting soil particles downslope.

Question 8

Flow(example+definition+factors)

Answer 8

Mudflow, A flow is a rapid, downslope movement of saturated soil, debris, or rock, where the material behaves like a liquid due to the presence of water.
* The material is fully saturated (high water content).
* It moves in a chaotic, internal mixing way — like a slurry.
* Occurs on moderate to steep slopes.
* Often triggered by intense or prolonged rainfall.
* The speed can vary from slow (soil creep) to very fast (debris flow or mudflow)

Question 9

Heave(example+definition+factors)

Answer 9

Soil creep, caused by individual soil particles being pushed or heaved to the surface by wetting, heating or freezing. Slow, small scale movement occurs mostly in winter.Moisture content varies, but generally is low.

Question 10

Slide(example+definition+factors)

Answer 10

Slides occur when an entire mass of material moves along a slip plane. Main two are: rotational(slump) and translational slides. Generally fast and moderately dry, although there is moisture in it.

Question 11

Factors that contribute to increased shear stress.

Answer 11

-Removal of lateral support through undercutting or slope steeping(Erosion by rivers and glaciers, wave action, faulting)
-Removal of underlying support(Undercutting by rivers and waves, subsurface solution, loss of strength by extrusion of underlying sediment)
-Loading of slope(weight of water, vegetation, accumulating of debris)
-Lateral pressure(water in cracks, freezing in cracks, pressure release)
-Transient stress(earthquakes, movement of trees in wind)

Question 12

Factors that contribute to reduced shear strength.

Answer 12

-Weathering affects
-Changes in pore-water pressure(Saturation, softening of material)
-Changes of structure(Creation of fissures in shales and clays, remoulding of sand and sensitive clays)
-Organic effects(Burrowing of animals, decay of tree roots)