Spatiotemporal dynamics of floodplain patterns during the last 400 years south of Leipzig - A regional scale analysis

Johannes Schmidt , Sophie Lindemann, Felicitas Geißler, Michael Hein, Niels Lohse, Julia Schmidt-Funke, Matthias Hardt

The Elster-Pleiße floodplain south of Leipzig has undergone significant hydromorphological changes over the past centuries, influenced by both natural processes and anthropogenic interventions. This study employs high-resolution LiDAR-based fluvial-geomorphological mapping (1x1 m resolution) and old maps analyses to reconstruct past river dynamics and identify shifts in channel morphology. Geomorphological mapping reveals an earlier, more dynamic floodplain characterized by meandering and anabranching channels, which transitioned into a system of stabilized, largely immobile watercourses. Comparative analyses of old maps spanning from the 16th to the 20th century indicate a gradual reduction in river sinuosity and lateral migration, coinciding with increasing human modifications such as mill races, timber rafting canals, and flood protection measures. Key transformations include the straightening of channels, floodplain aggradation, and the impact of open-cast lignite mining in recent centuries. The study highlights the complex interplay of climatic fluctuations, sedimentary processes, and anthropogenic activities in shaping the floodplain's evolution. Understanding these long-term dynamics provides crucial insights for contemporary river restoration and flood management strategies.