The correct answer is d) All of the above.
Afforestation is the process of planting trees in an area where there were previously no trees. This can help to stabilize landslide-prone areas by providing roots that hold the soil in place. Terracing is the process of creating a series of steps on a slope. This can help to reduce the amount of water that runs off the slope, which can reduce the risk of landslides. Retaining walls are structures that are built to hold back soil. They can be used to stabilize landslide-prone areas by preventing the soil from sliding down the slope.
Here are some additional details about each option:
- Afforestation: Trees have roots that grow deep into the soil. These roots help to hold the soil in place and prevent it from sliding down the slope. Trees also help to absorb water, which can reduce the risk of landslides.
- Terracing: Terracing creates a series of steps on a slope. This helps to reduce the amount of water that runs off the slope. Water that runs off a slope can cause the soil to erode, which can increase the risk of landslides. Terracing also helps to slow down the flow of water, which gives the soil more time to absorb it.
- Retaining walls: Retaining walls are structures that are built to hold back soil. They can be made of a variety of materials, including concrete, stone, and brick. Retaining walls help to stabilize landslide-prone areas by preventing the soil from sliding down the slope.
It is important to note that the best way to stabilize landslide-prone areas will vary depending on the specific conditions of the area. In some cases, one or more of the methods described above may be sufficient. In other cases, a combination of methods may be necessary. It is important to consult with a qualified engineer or other expert to determine the best approach for a particular area.