The formation of terraces and channel pattern changes in mountain riversSłowik, Marcin (Avtor) Golob, Nejc (Avtor) Grčman, Helena (Avtor) Zupanc, Vesna (Avtor) terrace formationmeandering riverswandering riversincisionthe Sava River valleyanthropogenic impactThe evolution of many European mountain rivers was marked by the formation of terraces. Conditions influencing the formation of new floodplain levels and trajectories of channel pattern changes in montane settings remain understudied. The main goal of our research was to determine factors influencing a spatial and temporal formation of terraces and changes in channel planforms of the upper Sava River (Slovenia). We also reconstructed a trajectory of channel planform changes, the traces of which are preserved within the terrace levels. Our research was based on geophysical and geological surveys, analyses of digital terrain models and historical maps, and data from other studies in the upper Sava and other mountain rivers of Europe. Incisions to new floodplain levels commenced in interstadials characterized by glacier retreat. Stabilization of the floodplain levels took place in cold periods 50,000–40,000 BP (terrace I); 35,000–20,000 BP (terrace II); 15,000–10,000 BP (terrace III), and 5000 BP (modern floodplain). We identified traces of meandering and wandering channel planforms within the terraces. The Sava River evolved from braided (terrace I), through meandering with local traces of wandering river at terraces II-III, to a wandering planform preserved in the modern floodplain. The wandering pattern was active until constructions of dams in the 20th century. The formation time of the Sava terraces corresponds to the evolution of other mountain rivers situated in the Alps, Pyrenees, and Crete. The identified sequence of terraces formation can be connected with warm and cold climate phases. The influence of the climate changes was enhanced e.g. by the formation of glacial lakes causing sediment deficits in river valleys after 20,000 BP and meander cutoffs increasing valley slopes especially during the transition to the wandering planform in the Early and Middle Holocene.20262026-04-20 14:59:21Članek v reviji181948sl