Question

You buy land in the tropics on steep mountain slopes covered by large trees and deep soil. You want to build a house on the land. Which of the following building plans is a very bad idea because of the danger of triggering mass wasting?
a. Excavate a flat bench on the slope for the house, pushing the debris to the slope below and leave a cut bank above the flat bench with grass planted on the steep slope.
b.Excavate the soil from the building site, install drainage systems, and backfill with gravel to prevent water accumulation.
c. Terrace the slope, building on the terraces, and constructing a rock retaining wall with voids to allow drainage of water.
d. Sell the land because it will always be prone to mass wasting.

Answer 1

Answer: a. Excavate a flat bench on the slope for the house, pushing the debris to the slope below and leave a cut bank above the flat bench with grass planted on the steep slope.

Explanation:

Mass wasting occurs when the pull of gravity overcomes the structure of a slope, thereby, eroding materials on the slope/mountain. The triggers of mass wasting include water, and rock displacement.

The presence and structure of debris found on a slope contribute greatly to the stability of the slope. Removing debris will make the process of  mass wasting easier by weakening the structure of the slope. So will excavating a flat bench as this will create an area for water to accumulate, which will weaken the structure of the slope further.