Simple modelling for a large-scale assessment of total phosphorus retention in the floodplains of large rivers

• Published in: Wetlands (Wilmington, N.C.) Vol. 41; no. 6; p. 68
• Main Authors: Schulz-Zunkel, Christiane, Baborowski, Martina, Ehlert, Thomas, Kasperidus, Hans D., Krüger, Frank, Horchler, Peter, Neukirchen, Bernd, Rupp, Holger, Scholz, Mathias, Symmank, Lars, Natho, Stephanie
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.08.2021; Springer Nature B.V
• Subjects: Biomedical and Life Sciences; Case studies; Coastal Sciences; Connectivity; Ecological function; Ecology; Ecosystem Services of Wetlands; Ecosystems; Environmental Management; Eutrophication; Flooding; Floodplains; Floods; Flow velocity; Freshwater & Marine Ecology; Hydrogeology; Hydrologic data; Land use; Landscape Ecology; Life Sciences; One dimensional models; Retention; River ecology; Rivers; Sedimentation & deposition; Sediments; Water purification; Water quality; Elbe; Phosphorous retention; Rhine; Floodplains
• ISSN: 0277-5212; 1943-6246
• DOI: 10.1007/s13157-021-01458-x

Floodplains provide a multitude of ecosystem functions and services with water purification being one of them. For this study we modelled the retention of total phosphorous (TP) in the floodplains of the river Rhine and the river Elbe, looking at sediment deposition as the main process responsible for removing TP from rivers during inundation events. We applied two different approaches: a proxy-based approach (PBA) and a one-dimensional model based approach (MBA). We used both to calculate the yearly TP retention and compared it with the annual TP load in the rivers. Compared to the transported river load the Elbe floodplains investigated retained approx. 4.9% TP resp. 1.4% (PBA vs. MBA) while in the floodplains of the river Rhine about 1.8% vs. 0.3% TP was retained. We found that the greatest difficulty in quantifying TP retention in floodplains is due to the lack of spatial detail on the hydrological connectivity between rivers and their adjacent floodplains and that a sound validation of the results is absolutely necessary. Long-term monitoring data for floodplains, especially on hydrological connectivity, are of crucial importance in this respect.