Ocena aktywności wybranych osuwisk w rejonie Jeziora Rożnowskiego w świetle badań terenu

The article compares results of field assessment of activity of selected landslides in the Rożnowskie Lake region, obtained in 2010-2014 with a differential digital models (DDM) from airborne laser scanning data of 2010, 2013 and 2018. Results of DDM analyses were similar to those from field studies. The most difficult task in the field research was to distinguish between active landslides, where the last movements took place over three years after the date of landslide registration, and periodically active landslides, the last visible movements that took place five years ago. The article underlines that not all displacements within the landslides, visible on differential terrain models, are the result of colluvium landslide movement. Sometimes they are due to anthropogenic activities. Differential digital model in the Znamirowice landslide presents terrain changes that have resulted from intensive agricultural land use.