The evolution of meandering and anabranching rivers in postglacial and loess landscapes of Europe

Abstract

This study aims to explain the influence of sediments and landforms of postglacial and loess landscapes of Europe on processes forming meandering and anabranching rivers. Based on a literature review, sedimentary architecture, types and grain-size of deposits, and channel planform changes since the Late Pleniglacial were collected for extensive set of European rivers. These data were used to create a conceptual model explaining the evolution of meandering and anabranching rivers in both types of landscape. The present study shows that the inheritance of glacial and fluvioglacial landforms and sediments, and loess formation, influence types of processes forming anabranching and meandering rivers. Point bar accretion formed meandering rivers in postglacial zone whereas oblique accretion dominated in loess areas. Anabranching rivers of postglacial zone evolved through the formation of crevasse channels and meandering anabranches. Anabranching rivers of loess zone formed sustained bifurcations. Postglacial and loess rivers reacted differently to increased deposition and humidity in the Late-Holocene. Meanders of postglacial zone formed channel bars owing to increase in stream power and sediment load. In cases of flow energy decrease, and sustained upstream sediment delivery, they turned into anastomosing rivers. Anabranching rivers in ice-marginal valleys maintained its courses until hydro technical works in the 19th century. Low-energy meandering rivers of loess areas became wetlands owing to deposition of silts. High-energy meandering and anabranching rivers maintained the planforms throughout the Holocene. These findings need to be refined by detailed studies on the evolution of rivers in subarctic zone, and large rivers of Europe.

Diversity of soils in the Dnipro River valley (based on the example of the Dnipro-Orilsky Nature Reserve)

“…Meandering and anabranching rivers were the most common types of channel forms in Europe in the Late Pleniglacial (~30,000-14,700 cal BP -"calibrated years before the present"), Late Ice Age (14,700-11,700 cal BP), and Holocene (Słowik, 2023). In many parts of the European continent, well-developed terrace systems have been preserved.…”

Impact of Climate Change on Water Sources and River‐Floodplain Mixing in the Natural Wetland Floodplain of Biebrza River

“…Climate change in Europe during Holocene resulted in increased stream power and sediment load, which affected in creation of meanders or the transition between meandering and anastomosing rivers (Słowik, 2022). In case of the analyzed floodplain the current meanders and paleochannels in the fluvial terrace are relatively new and were developed along with increasing peat deposition during younger Holocene which now covers the effects of river activity during older Holocene and Pleistocene (Banaszuk & Micun, 2009).…”