Clay landslides are not uncommon in Norway, especially sensitive clay slides that produce many economic losses each year. Sensitive clay slides have been studied since the 1950’s and their failure mechanisms as well as the triggering factors are quite well known.
Less known are the failure mechanisms and triggers of landslides that involve sand, silt and/or clay (not sensitive). They occur often along river banks or steep slopes of relatively short height. Often in the lowlands in Norway, especially South-eastern Norway, Trøndelag area where fine quaternary deposits are more frequent above the bedrock.
Observations from the last 10 years of landslide early warning show that they occur when there are flood conditions in the rivers. They can occur at the beginning of the flood event when the water discharge starts to rise and produce erosion or during the retreat of the flood level.
These types of landslides often occur in rural areas and cannot have direct consequences for the population, but they can create a natural dam in the river and cause flooding upstream.
This thesis will investigate the conditioning factors, triggering mechanisms and behaviour of a specific landslide or a group of landslides that occurred under Storm Hans along rivers.
Remote sensing images will be used, as well as water discharge data and other data from xgeo.no to define better-triggering conditions. Fieldwork will be included.
The expected results will be a better understanding of the failure behaviour of sandy clay slides. The results of this research will be relevant for hazard mapping, land use plans and landslide early warning systems.