On steep slopes such as moraines, landslides most often occur when the soil is saturated following a period of high precipitation or in conjunction with snow melting. Where the slope is long and steep, the saturated mass of soil from a moraine landslide high up can flow further down the slope as a mudslide.
As long as the slope is steep enough, the mudslide will continue moving downwards, and along the way the ground and surroundings will be affected by very powerful erosion.
Increased problems in the future
In many areas, climate change will mean that the volume of precipitation increases, as does the number of incidents of extreme precipitation. This leads to increased runoff and erosion, which in turn leads to an increased probability of moraine landslides and mudslides that are greater in scope. This is a major threat to human life, as well as to buildings, infrastructure and other property.
It is essential that this is taken into account in the planning process for new settlements and infrastructure. Preferably, these threats should be avoided completely through a well-thought-out localisation of high-risk areas. Otherwise, the increased threat must be prevented with different protective measures.