Reconstructing Eger floodplain development (Nördlingen, southern Germany): An interdisciplinary approach to land use change, paleoenvironment, and pollution history

Understanding long-term interactions between humans and their environment requires integrative approaches that combine natural sciences with historical and social perspectives. Floodplains constitute particularly rich archives in this regard, as they record the long-term interplay between human activities and natural ecosystems. This study presents an interdisciplinary framework combining geophysics, geomorphology, paleoenvironmental analysis and biogeochemical proxis, land-use studies, archaeology and historical sources to reconstruct the Eger River floodplain evolution from the Holocene multi-channel anastomosing system to the recent, extensively straightened, highly regulated urban riverscape.This study is grounded in development-led geoarchaeological excavations in the vicinity of the medieval hub of Nördlingen, southern Germany. Strategically selected key sites along the river corridor upstream and downstream of the medieval town allow comparative analyses, with a focus on how the town and its associated activities and urban crafts influenced floodplain dynamics.Our methodology adopts an interdisciplinary, multi-proxy approach. Old maps and archival data inform the spatial reconstruction of water use; together with geophysical surveys, these guide targeted coring campaigns. Sediment cores are analysed by a comprehensive suite of laboratory analyses (sediment texture, stationary X-ray fluorescence (XRF) spectrometry, CNS analysis, carbonate content and pH measurements, Urease activity, soil microbial biomass and stable isotope ratios (δ13C, δ15N)) and geochronological analyses (radiocarbon dating, luminescence dating). All findings are subsequently contextualised with the robust archeological and paleoenvironmental datasets.The development and integration of our multi-proxy framework has yielded a high-resolution biogeochemical and chronostratigraphical model of its floodplain which is essential for gaining comprehensive insights into the history of Eger River water management. Our reference model identifies three major sediment units of fluvial origin, together with anthropogenically driven higher concentrations of heavy metals in the topsoil. Our study effectively reconstructs the spatial and temporal progress of human related landscape, land-use and environmental changes in a characteristic mid-European floodplain.