Human Impacts 3.4 Flashcards
(14 cards)
Surface loading
The addition of weight onto a slope. This can be either by building, or adding water. Water also has a lubricating effect.
Waste heaps
Waste heaps can collapse such as in the case of the Abderfan disaster of 1966, when, on the 21st October, 116 children and 28 adults were killed when a spoil heap from a nearby coal mine collapsed in Wales due to a build-up of water which saturated the material in the waste heap
Traffic vibrations
Traffic vibrations, especially from heavy vehicles, can trigger mass movements.
Excavations
Excavations involve the removal of material from a slope, and if the slope is left at too steep an angle, can result in mass movement
Ploughing+ poor agricultural practices
Affects slope shape
Affects slope stability↓
Ploughing in the direction of slope gradient can develop rills. Similarly, soil structure can be destroyed through poor agricultural practices, which loosens slopes.
Pinning
Pinning(steel bars) is used to attach wire nets(os sometimes concrete blocks) to a rock face or slope.
Netting
Netting can be secured to slopes to stop material falling
Drainage channels
Remove excess water from a slope and mean the slope material cannot become lubricated.
Grading
Grading reduces the slope angle and therefore the likelihood of mass movement occurring
Gabions
Wire cages filled with rocks can be used to stabilise slopes
Grouting
Grouting involves injecting permeable rocks with cement to increase shear strength
Shocrete
Concrete can be sprayed onto loose surfaces to bind them.(a method of applying concrete on high velocity)
hazard mapping
hazard mapping can be used by governments to decide which areas are most likely to experience factors that could lead to mass movements e.g. areas of heavy rainfall.
Type of human impacts:
- Surface loading
- Waste heaps
- Traffic vibrations
- Excavations
- Ploughing+poor agricultural practices
- Pinning
- Netting
- Nailing
- Drainage channels
- Grading
- Gabion boxes
- Grouting
- Shocrete
- Hazard mapping
