Answer:
d. Redirecting surface water flow so that it travels around and away from the landslide and covering the landslide with a water impermeable membrane.
Step-by-step explanation:
Slopes are created when erosion acts on uplifts formed during tectonic processes. The angle, physical qualities of the materials found on the slope, and the activities carried out on the slope will determine its stability.
Some activities which threaten a slope’s stability include introducing heavy weights on the sides of a slope and exposure to water which affects the structural integrity of the rocks on the slope. This is why a highway construction, residential development and enabling intermittent erosion are bad ideas for bolstering the stability of a slope.
While the presence of vegetation on a slope makes it more stable, removal of present vegetation and irrigation will weaken the structure of a slope.