The intensity of erosion and its causes on the shores of artificial reservoirs: The role of slope gradient and vegetation cover

Kaunas Reservoir, the largest artificial body of water in Lithuania, has been characterized by active coastal erosion processes since its formation, which are currently exacerbated by more intense precipitation, water level fluctuations, and recreational use.The aim of the study was to assess the condition of the Kaunas Reservoir shores and to determine the differences in erosion intensity in different sections, linking them to slope gradient, vegetation cover, and recreational activity characteristics.The research was conducted at three study sites (1-3) along the coast; at each site, the height of the shore, slope gradient, vegetation cover, signs of erosion, and recreational load were measured in ~50 m sections (GPS coordinates, photo documentation).The highest vulnerability was found at site 1: slopes were 2.6-5.6 m, gradients were often >30° (up to ~42°), vegetation cover was 11-28%; 5 out of 10 sections were classified as class 3, the rest were identified as class 2. In the third location, the banks were stable: low to medium (slopes 10-20°), cover 68-85%, the shore is protected by continuous strips of reeds; all sections were class 0-1.Class 1 prevailed in the second location (80% of sections), while class 2 was recorded in only two locations, where the cover has decreased to ~56-58%, the slope was ~19-19.5°,and the height was ~2.4-2.5 m.A pattern emerged: when the slope is >30° and the cover is