Erosion is an environmental concern for both its on-site and off-site effects. Changing land use and climate dynamics call for ongoing adaptations of land users and land use planners. Gully erosion is a
significant soil degradation phenomenon that is sti ll poorly redictable. Quantification under changing conditions calls for modelling gully initiation and development in a process-based approach. Runoff as
the result of rainfall and snowmelt cause overland ow and this causes particle detachment and erosio n. Microtopography determines the degree and location of concentration of overland ow. Measurement
and characterisation of overland therefore play a pivotal role in the increase of the gully initiation process. In Norway, ephemeral gullies emerge mainly i n early spring when sudden thaw occurs together with rainfall. Studying the phenomenology of gullies in the eld and recording microtopography are crucial in the stage of conceptual model building. In this project, a dynamic model for gully initiation is c onstructed, i.e. a model that takes changes in soil surface level and morphology into account for the period of gully initiation.