RIVER MORPHOLOGY MONITORING OF A SMALL-SCALE ALPINE RIVERBED USING DRONE PHOTOGRAMMETRY AND LIDAR - Backes, D.; Smigaj, M.; Schimka, M.; Zahs, V.; Grznárová, A.; Scaioni, M. (Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., 2020)