Geo-e-learning grade 11-12.com

  Prone areas Modify the slope gradient by removal or addition of material Build retaining walls to increase external support. Plant deep rooted plants to bind regolith. Create berms in place where Rock fall are anticipated like rock cuts. Install rock bolts or artificial plant roots that mechanically bolt weak rock layers to the bedrock.

On a slope Tension gashes in a road  Telephone pole tilt Fences tilt and bend or break Base of tree turns downslope Terracettes form on slope Soil pile up behind walls

  Strategies Modify the slope gradient by removal or addition of material. Build retaining walls to increase external support. Plant deep rooted walls to increase external support. Create berms in place where Rock fall are anticipated like roads cuts. Install rock bolts or artificial plant roots that mechanically bolt weak rock layers to the bedrock.

  Human impacts

  Scree Is formed because of weathering and occurs at the foot of the mountain, frost shattering takes place in colder areas or in high mountains regions. There is little water available with limited vegetation cover.

  Rockfalls Are the sudden falling of individual rocks from near vertical cliffs, often result from frost wedging in cold mountainous areas and water saturation in humid mountainous areas as the rocks fall they break down and collect at the bottom of the slope those broken rocks are then called talus. Lands lides Are the sudden movement of large quantities of loose surface rocks and soil down valley sides and cliff faces. Landslides also result from gravitational pull and wetness caused by water, landslides can result in loss of life and destruction of property, especially if the rock material consist of huge masses of rocks.

 Soil flow/Solifuction Mud flow Rotational slide/slump Rockfall Soil creep Mudflows Occurs when the slope materials become so saturated that the cohesive bond between particles are lost. Saturated material then flow downslope like a thick fluid. The flow stop when water is lost through seepage. Mudflow occurs at steeper slopes causing rapid run-off, after periods of intensive (heavy) rainfall volume and weight is added to the soil. The soil overlies impermeable bedrocks, when mud loses its momentum large boulders are deposited. Soil creep Is the slow movement of soil down the slope it occurs on a very gentle slope , where there is vegetation cover. The rate of soil creep increases when the soil on the slope is wet, soil creep is caused by earthquakes, alternate wetting and drying of the soil, movements of animals, heating and cooling of soil. Soil creep is destructive because it can dislocate telephone poles, trees, stone walls and fencing

  Crest -top of hill, convex in shape, limited movement by soil creep. Scarp(free face, cliff) -almost vertical rock outcrop Talus/scree(debris)slope- uniform slope at foot of talus. Angle determined by materials . Angle remains constant. Debris accumulates. Pediment- low angle at foot of talus /gentle slope before the scree, erode rock surface, thin covering

  Facto rs that affect mass wasting  gravity water in the spoil amount of vegetation human activity(buildings or roads on the slope) earthquakes presence of animals  presences of bedding planes on the slope Origin of slopes slopes are classified according to origins Tectonic forces-earthquakes, folding Erosion- valleys, cliffs by water , ice, wind and waves Deposition- beaches, sand dunes, alluvial fans by water, waves and wind

 The Geo knowledge blog is a blog that target high school learners particularly grade 11 and 12 it intends to give them a broader understanding of geography topics. This blog being published is mainly focused on mass movement just to give learners a better understanding of the topic. Mass movement also known as mass wasting is the process by which a variety of processes cause materials to move down a slope due to gravity. The operation of mass movement processes relies on the development of instability in the slope caused by stress exerted on the slope which exceeds its strength. The are short and long term triggers such as gravity and its magnitude depends on the angle of the slope and weight of sediments and rock on the slope.