From natural- to human-dominated fluvial landscapes: sediment dynamics & anthropogenic interaction of the Wiesent River catchment (NE-Bavaria, Germany)

Since the Late Holocene the impact of human activity on fluvial systems in Central Europe has reached unprecedented levels, reshaping riverine landscapes and their floodplains. This led to a change in the sedimentary system, causing a transformation of the fluvial morphology. The Wiesent River catchment in northern Bavaria, Germany, serves as a case study for understanding this transition from natural to human-dominated floodplain systems since the Early Middle Ages. Utilizing sedimentological, (chrono)stratigraphical, and geophysical analyses, we investigate how direct interventions (e.g. hydrotechnical installations) as well as indirect influences (e.g. catchment-wide agriculture) have collectively changed the fluvial geomorphology and sedimentary dynamics of the area.

Here we present a detailed examination of floodplain architecture, highlighting thick overbank deposits and changes in sediment dynamics that serve as proxies for anthropogenic activity. Our results, derived from optically stimulated luminescence (OSL) dating, reveal significant shifts in sedimentation rates that correlate with the intensification of human activities, such as deforestation for agriculture and the establishment of hydrotechnical installations. Concurrently, we explore paleoenvironmental indicators, including phytoliths, biomarkers and ostracods, to assess ecological responses within the floodplain over time.

This research underscores the critical role of geomorphology in the broader context of the interaction between human agency and environmental processes. By contrasting natural and anthropogenically influenced systems, we aim to enhance the understanding of mechanisms driving the fluvial geomorphic change. Thereby we contribute to the discourse on sustainable landscape management and restoration practices in the face of ongoing environmental challenges.