| dc.description.abstract | Shallow landslides in soils, such as debris flows and debris avalanches, are expected to increase in frequency and intensity in large parts of Norway. The simulation, characterization and statistical analysis of such events require extensive data, and the statistical analysis requires numerous events to do statistics on. A standard field work form is believed to be useful in the collection of such data, and improve the comparative analysis in future studies. The objectives of this thesis are the development and testing of a field work form, and the detailed characterization of four selected landslides. The field work form is based on literature studies, expert feedback, and field testing done as part of the characterization of each landslide. Three debris flows and one debris avalanche were selected and surveyed using the field work form. Soil samples were collected at all sites and weather data extracted for two sites with known date of occurrence. Furthermore, geophysical methods were used at one site. Runout simulations, using DAN3D, were carried out for three sites, and the collected data was used for setting up the models. Simulation results agree with the field observations and the field work form is considered to suite its purpose, the most significant uncertainty being velocity estimations, due to the lack of field observations. A terrain model interpolated from GPS data gathered in the field was shown to improve simulation results. The sites were thoroughly characterized, and all triggering conditions seem to be the result of extreme groundwater and runoff conditions. Explanations to what affected the initiation of each landslide are discussed. Surface and subsurface structures favoring water infiltration are common for all the sites. In addition, thin soil cover, weathered bedrock and sliding planes are recurrent factors of importance to the landslide initiation at the four selected sites. The thesis is part of the KLIMA2050 research effort. | eng |