Gully erosion; Dendrogeomorphology; Root exposure; Triggering rainfall; NE Czechia

The recent acceleration of gully erosion caused by environmental factors and human impacts has led to an enhanced demand for applied research in risk-prone areas worldwide. We investigated the dynamics of gullies that have recently threatened dwellings and railways in the foreland of the Eastern Sudetes (340-390 m a.s.l. in the NE part of Czechia). Flood countermeasures in a residential area above the study site created conditions conducive to accelerated erosion in the gullies; thus, the main aim of this study was to determine how human interventions changed the spatio-temporal dynamics of the gullies during a short period. Twenty two gullies (with a mean length 48.5 m) have developed on a 1-km-wide escarpment (with a mean slope 25 degrees) composed of glaciogenic sediments of various sizes. Dendrogeomorphic techniques were applied on 23 exposed roots of Tilia cordatel Mill. (a tree species that has never been used to detect root exposure). Microsections were prepared using a G.S.L.1 sledge microtome and analysed using the WinCELL Reg software to determine the timing of root exposure.