A landslide is a mass movement of material, such as rock, earth or debris, down a slope. A landslide can happen suddenly or slowly over long periods of time.
When the force of gravity acting on a slope exceeds the resisting forces of a slope, the slope will fail and a landslide occurs. External factors can lead to landslides happening, including:
- Heavy rainfall leading to the ground becoming full of water and too heavy.
- Erosion of the base of a slope.
- Changes to the material’s strength through weathering.
Major unstable area along Ramu-Madang Highway
Monitoring of landslides is carried out solely by on-site, physical inspection, unlike PMGO and RVO were real-time monitoring is carried out remotely using state-of-the art monitoring equipment.
In the absence of real-time monitoring, susceptibility mapping is an essential activity in monitoring landslides. Production of susceptibility maps informs stakeholders as to location and possible extent of future events. Moreover, regular updating of these maps must be carried out to ascertain previously mapped locations’ level of susceptibility.