TY - CHAP A1 - Altenkirch, Nora A1 - Mutz, Michael A1 - Molkenthin, Frank A1 - Zlatanović, Sanja A1 - Trauth, Nico T1 - Untangling hyporheic residence time distributions and whole stream metabolisms using a hydrological process model T2 - European Geosciences Union, General Assembly 2016, Vienna, Austria N2 - The interaction of the water residence time in hyporheic sediments with the sediment metabolic rates is believed to be a key factor controlling whole stream metabolism. However, due to the methodological difficulties, there is little data that investigates this fundamental theory of aquatic ecology. Here, we report on progress made to combine numerical modeling with a series of manipulation to laboratory flumes overcoming methodological difficulties. In these flumes, hydraulic conditions were assessed using non-reactive tracer and heat pulse sensor. Metabolic activity was measured as the consumption and production of oxygen and the turnover of reactive tracers. Residence time and metabolic processes were modeled using a multicomponent reactive transport code called Min3P and calibrated with regard to the hydraulic conditions using the results obtained from the flume experiments. The metabolic activity was implemented in the model via Monod type expressions e.g. for aerobic respiration rates. A number of sediment structures differing in residence time distributions were introduced in both, the model and the flumes, specifically to model the biogeochemical performance and to validate the model results. furthermore, the DOC supply and surface water flow velocity were altered to test the whole stream metabolic response. Using the results of the hydrological process model, a sensitivity analysis of the impact of residence time distributions on the metabolic activity could yield supporting proof of an existing link between the two. Y1 - 2016 UR - http://meetingorganizer.copernicus.org/EGU2016/EGU2016-14435.pdf N1 - EGU2016-14435 PB - European Geophysical Society CY - Katlenburg-Lindau ER - TY - GEN A1 - Altenkirch, Nora A1 - Zlatanović, Sanja A1 - Woodward, K. Benjamin A1 - Trauth, Nico A1 - Mutz, Michael A1 - Molkenthin, Frank T1 - Untangling hyporheic residence time distributions and whole stream" "metabolism using a hydrological process model T2 - Procedia Engineering N2 - The interaction of the water residence time (RT) in hyporheic sediments with the sediment metabolic rates is believed to be a key factor controlling whole stream metabolism. However, due to the methodological difficulties, there is little data that investigates this fundamental theory of aquatic ecology. Here, we report on progress made to combine numerical modelling with a series of modification to laboratory flumes overcoming methodological difficulties e.g. by creating steady flow paths for assessment of metabolic rates. To model the biogeochemical performance and to validate the model results, sediment structures were introduced in both, the model and the flumes, leading to differing RT distributions. Furthermore, the DOC supply in the flumes was manipulated to test the whole stream metabolic response with regard to RT distributions. In the flumes, hydraulic conditions were assessed using conservative tracer and heat as tracer. Metabolic activity was assessed using oxygen dynamics as a proxy of community respiration (CR). Residence time and metabolic processes were modelled using a multicomponent reactive transport code called MIN3P and calibrated with regard to the hydraulic conditions using the results obtained from the flume experiments. Monod type expressions were used to implement metabolic activity terms in the model. Using the results of the hydrological process model, a sensitivity analysis of the impact of RT distributions on the metabolic activity could yield supporting proof of an existing link between the two. KW - residence times KW - metabolism KW - MIN3P Y1 - 2016 UR - http://www.sciencedirect.com/science/article/pii/S1877705816319877 U6 - https://doi.org/10.1016/j.proeng.2016.07.598 SN - 1877-7058 N1 - 12th International Conference on Hydroinformatics, HIC 2016, Incheon, Korea VL - 154 SP - 1071 EP - 1078 ER -