Three human activities that may make the slopes unstable are the following:
1. Deforestation
Cutting off trees may result to loose soil since there will be lesser roots that will hold the soil together. When rain water runs off the slope, it will make the slope more unstable, resulting to mud/land slide.
2. Water excavation/extraction
This may also result to unstable slope, because the soil may sink as more water is extracted from the ground to supply the need of the growing population. In extreme cases, this may result to the formation of sinkhole.
3. Drilling of the earth
Drilling may result to unstable slope if is done in a landslide prone area as it will disturb the formation of rocks and soil.
