Strategies to Reduce Mass Movement

Question 1

What are examples of strategies, humans put in place, that cause an inc. in slope stability?

Answer 1

• afforestation
• netting
• pinning
• grading

Question 2

How does afforestation inc. slope stability?

Answer 2

• tree roots inc. internal strength of soil: slope can take more stress before fails
• more trees dec. soil saturation: by intercepting pptn + water uptake from roots
  • dec. risk of mass movement from high soil saturation lvls
  • dec. erosion by water

Question 3

How does netting inc. slope stability?

Answer 3

• netting/mesh placed over slope
• contains falling debris/rock so doesn’t fall beneath netting: limits hazard
• prevents falls as little room for anything to fall
• effective at inc. stability of rock slopes

Question 4

How does pinning inc. slope stability?

Answer 4

• pinning, nailing + bolting slopes inc. strength
• soil nailing: steel rods drilled into soil + can carry weight: inc. stability + dec. risk of mass movement
• rock bolting: bolts drilled into rock slopes in a specific pattern - transfers load from weaker exterior to stronger interior
  • dec. risk of rockfalls/slides

Question 5

How does grading inc. slope stability?

Answer 5

• re-profiling slopes, so are more stable: using heavy machinery (e.g. excavators + graders)
• provides uniform landscape
  
  • for building, controlling surface runoff or minimising erosion
• reinforces slope so mass movement less likely