What have people done to try to control the forces caused by this natural event-landslides?

Answer 1

There are many ways to reduce the potential for landsliding. This can involve preventing new landslides or re-activation of pre-existing landslides. One of the most important steps to take is to understand the structure of the bedrock (assuming we are talking about a bedrock landslide). Geologic mapping or drilling can reveal the type of bedrock and the orientation of the discontinuities (eg. bedding planes, previous rupture surface). Mainly those slopes that have bedding tilted the same direction as the sloping hillside surface and that are tilted at an angle less than the hill slope angle are likely to generate unstable conditions. From that point there are several measures you can take including:

Removal of material from the upslope portions of the unstable areas (to reduce the mass that would provide a driving force).

Placement of soil/dirt at the base of the unstable slope to act as a buttress (adding mass to create a resisting force)

Reduce the amount of surface water that can percolate through the rock and add weight (i.e. driving force) to the unstable bedrock. This can be done by constructing concrete drainage ditches to collect and divert the water or by covering the slope with an impermeable barrier (i.e. plastic). If this is the main condition that is driving landsliding, you can set-up a system of wells drilled into the unstable material and pump the water out.

In some cases, the unstable bedrock material can be removed with heavy equipment and the slope can be rebuilt with the excavated dirt being replaced as compacted fill.

Answer 2

plant more trees and don't cut as many down

Answer 3

Elevated land