Application of unmanned aerial vehicles for geomorphological mapping of landslide slopes of the Aibga ridge (Western Caucasus)

Abstract

Aerial sounding of the study area of the northern slope of the Aibga Ridge was carried out using unmanned aerial vehicles (UAVs) for geomorphological large-scale geoinformation mapping of landslide slopes. The site of work was chosen on the basis of the previously carried out ecological and geomorphological zoning of the slopes of the Aibga Ridge (Sochi National Park) and represents the slopes of the Chernaya Piramida mountain covered with forest and alpine meadows. A fragment of the ridge slope in the area of an ancient stabilized seismogenic gravitational landslide was studied. The morphology of the relief was partially changed during the construction of sports facilities—ski slopes and cable cars. The creation of clearings in forests, a partial change in the morphology of the natural relief and surface runoff conditions led to local activation of landslide processes, including on ski slopes and other infrastructure facilities. The newly formed landslide slopes are confined to the junction of natural and man-made relief forms: the ski slopes and the slopes of the hollows of temporary watercourses. As a result of field work using the global navigation satellite system (GNSS), a local reference geodetic network of centimeter accuracy was formed—a planned-altitude substantiation (PVO), which served as a geodetic basis for processing sounding materials and subsequent geoinformation mapping. Aerial sounding was carried out using the DJI Mavic 2 Pro and DJI Mini UAVs, more than 1,000 digital images of the study area in nadir and prospective have been accumulated. In addition, in order to identify the relief forms of the underlying surface on separate fragments of the study area, covered with dense broad-leaved forest (beech, hornbeam), a tacheometric survey was carried out. Field research materials served as the basis for geomorphological mapping of the landslide slopes of the Aibga Ridge and the creation of the corresponding thematic layers in the GIS software environment.