Answer:
Step-by-step explanation:
1. Slope Instability: Slopes that are inherently unstable due to their geology, such as weak rocks or loose soil, are more prone to landslides. The angle of the slope, known as the slope's steepness or gradient, can also contribute to instability. Steep slopes are more likely to experience landslides compared to gentle slopes.
2. Heavy Rainfall: Rainfall plays a significant role in triggering landslides. When soil becomes saturated with water, it can lose its strength and cohesion, making it more prone to sliding. Intense or prolonged rainfall can increase the water content in the soil, leading to instability and triggering a landslide.
3. Earthquakes: Earthquakes can cause landslides by shaking the ground and destabilizing slopes. The ground shaking can reduce the friction between soil or rock layers, causing them to slide downhill. Earthquakes can also trigger landslides indirectly by generating ground vibrations that loosen the material.
4. Human Activities: Human activities can contribute to landslides in various ways. Excavation or construction on slopes can alter the natural stability of the area, leading to instability and potential landslides. Deforestation, improper land management, and changes in drainage patterns can also increase the risk of landslides.
5. Volcanic Activity: Volcanic eruptions can generate landslides due to the release of hot gases, ash, and volcanic debris. These materials can mix with water from rain, rivers, or melting snow, forming fast-moving debris flows known as lahars.