Human Impact on Slopes

Question 1

Mining

Answer 1

• mining removes support from the slope, both underlying and lateral.
• leads to instability within slope, causing landslides, mudslides, rockfalls etc
• mining and quarrying = ↑ waste, often left on slope, ↑ stress = MM processes

Question 2

Construction

Answer 2

• compromise stability on slopes when change of topography
• stress on hillslope added (weight of housing/dams)
• slopes may be undercut to build, which causes instability
• groundwater affected due to sewage/drainage systems + water demand

Question 3

tourism

Answer 3

• prevalent in hillslope areas esp alpine slopes where skiing is common
• erosion of slope ↑↑ due to trampling of vegetation, skis, machinery and people
• alpine areas where seasonal melting occurs, ↑ of water can = MM (mudslides) to occur

Question 4

agriculture

Answer 4

• soil compacted from machinery and animals. leaves slope vulnerable to soil erosion, reduction in vegetation cover
• overgrazing and trampling means ↓ veg. cover and so degradation of soil. with less vegetation, MM are more of a hazard.
• ↑ soil erosion as less vegetation. hillslopes left exposed, so erosion nd weathering ↑.

Question 5

forestry

Answer 5

• deforestation → slope instability
• roots of trees strengthen soil, so when trees cut, roots die so hill strength ↓
• deforestation = ↓ interception of precip, so more water infiltrates, = saturated leads to mass movements (mudslides)

Question 6

afforestation

Answer 6

• planting trees in area without trees, to ↑ stability of slopes
• roots increase internal strength so slope can take more stress before falling
• ↓ saturation of soil, so risk of MM ↓, and ↓ erosion caused by water as some infiltrated

Question 7

Netting

Answer 7

• netting / mesh can be placed over slope to stabilise
• contains any falling debris, so hazard is limited
• prevents rockfalls, effective for ↑ stability of rock slopes

Question 8

Pinning

Answer 8

• soil nailing = where steel rods are drilled into soil. rods can carry weight, ↑ stability of slope so ↓ risk of MM
• rock bolting = bolts drilled into rock slopes in a pattern, transfers load from weaker exterior to stronger interior of slope. ↓ risk of rockfall + rockslide

Question 9

grading

Answer 9

• process of reshaping surface of slope
• to provide more uniform topography, e.g. for building, controlling surface runoff or minimising erosion.
• reinforces slopes so MM less likely