5. Conclusions
Assessment of the retreat rates of the landslide scarp is possible using both remote sensing from space and orthophoto maps obtained from UAVs and classical total station surveys. All these sources of information are interchangeable and complementary when working in the same coordinate system. The use of historical archival aerial photographs allows to assess the intensity of this land degradation process since the initiation of landslide processes.
The monitoring of landslide processes using a set of different measurement methods reveals that the rate of volumetric changes as a result of landslide processes at Site 1 has remained stable during the period of measurements and is – 0.03-0.04 m3/m2/year, with the most significant contribution to the average annual value being made by snowmelt runoff. The spatial dynamics of the landslide edge at Site 2 showed a steady decreasing trend of the retreat rate, beginning in 2002-2003, associated with partial overgrowth of the landslide accumulation zone and its relative stabilization. The average speed of landslide scarp retreat rate for of the entire observation period is 2.3 m/year. In recent years’ landslide control measures taken in this area have reduced the landslide scarp retreat rate by more than 2.5 times to 0.84 m/year.