Water & Solute Dynamics in Catchments

Predicting the solute flux response of a catchment to dynamic hydrologic forcing is a challenging task due to the wide range of complex processes that affect the availability, mobility and subsequent transport of solutes. However, there is some evidence that simpler general principles and mechanisms can be identified for certain catchments that adequately describe the integral effect of the combined processes. Fluxes of reactive solutes such as nitrate may be related to the transit times of water within the catchment. The main goal of our research is to identify the dominant controls of integrated catchment-scale solute response for different catchments and solutes and to develop new data and model driven concepts to describe and quantify the associated dynamics.

catchment processes
Processes controlling solute dynamics in catchments. (Source J. Fleckenstein)

Projects & Research activities

SFB CAMPOS
SFB Campos website

DOC dynamics & TALKO (finished in 2015)
TALKO (BMBF-funded project) brought together hydrologists, biologists, lake researchers, engineers and water supplier to tackle the problem of increasing DOC surface water loads and concentrations threatening drinking water supply from reservoirs. Within this project our group focused on advancing the process understanding of DOC mobilization. One still ongoing activity is the detailed analysis of water flowpaths and discharge generation in riparian wetlands that mobilizes DOC. Here we build on instream high-frequency measurements of DOC quantity and quality with UV-VIS probes and on a dense network of piezometers (PhD project Benedikt Werner). Within TALKO we were moreover able to evaluate long-term DOC concentration trends and co-variation with dissolved iron, nitrate and phosphorus across a wide range of catchments in Germany. This allowed us to raise new hypotheses on dominant controls of long-term trend (see Musolff et al. 2017a, Musolff et al. 2017b).
TALKO project website

C-Q relationships
We use concentration-discharge relationships as a data-driven analysis tool to understand mobilization and export processes of solutes at catchment scale (Musolff et al. 2015). This incorporates the pattern (direction) of the log-log relationship and the regime in terms of concentration variance relative to discharge variance. On the one hand, we explore data and use stochastic models to evaluate how C-Q relations evolve under different boundary conditions and solute source configuration within a catchment (Musolff et al. 2016, Musolff et al. 2017c). On the other hand we apply this framework to observed C-Q time series to classify archetypes of solute export behavior (Musolff et al. 2015, Dupas et al. 2017).

Water and solute transit times
The probability distribution of water age leaving a catchment is a promising tool to characterize and predict water flow and transport processes. However, water age distribution in discharge cannot be easily measured. Thus, we rely on numerical flow and transport modelling codes to explore the controls of transit time distributions (Jie Yang and Ingo Heidbüchel). On the other hand, we use long-term time series of nitrogen surplus and observed nitrogen outputs from catchment to derive effective travel times integrating biogeochemical time lags as well as the travel times along the flow paths (PhD project Sophie Ehrhardt).

TERENO
TERENO project website

Publications

  • Trauth, N., Musolff, A., Knöller, K., Kaden, U. S., Keller, T., Werban, U., Fleckenstein, J. H., (2018): River water infiltration enhances denitrification efficiency in riparian groundwater, Water Res. 130 , 185 - 199
  • Musolff, A., Selle, B., Buettner, O., Opitz, M., Tittel, J., (2017a): Unexpected release of phosphate nad organis carbon to streams linked to declining nitrogen depositions, Global Change Biology doi: 10.1111/gcb.13498
  • Musolff, A., Selle, B., Buettner, O., Opitz, M., Knorr, K.H., Fleckenstein, J.H., Reemtsma, T., Tittel, J. (2017b) Does iron reduction control the release of dissolved organic carbon and phosphate at catchment scales? Need for a joint research effort. Global Change Biology 23(9), doi: 10.1111/gcb.13758.
  • Musolff, A., J. H. Fleckenstein, P. S. C. Rao, and J. W. Jawitz (2017c): Emergent archetype patterns of coupled hydrologic and biogeochemical responses in catchments, Geophys. Res. Lett., 44 , doi:10.1002/2017GL072630.
  • Vieweg, M., Kurz, M. J., Trauth, N., Fleckenstein, J. H., Musolff, A., Schmidt, C., (2016): Estimating time-variable aerobic respiration rates in the streambed by combining electrical conductivity and dissolved oxygen time-series, J. Geophys. Res. 121 , 2199 - 2215
  • Musolff, A., Schmidt, C., Rode, M., Lischeid, G., Weise, S.M., Fleckenstein, J. H., (2016): Groundwater head controls nitrate export from an agricultural lowland catchment, Adv. Water Resour. 96 , 95 - 107
  • Dupas, R., Jomaa, S., Musolff, A., Borchardt, D., Rode, M., (2016): Disentangling the influence of hydroclimatic patterns and agricultural management on river nitrate dynamics form sub-hourly to decadal time scales, Sci. Total Environ. 571 , 791 - 800
  • Kamjunke, N., Oosterwoud, M. R., Herzsprung, P., Tittel, J., (2016): Bacterial production and their role in the removal of dissolved organic matter from tributaries of drinking water reservoirs. Sci. Total Environ. 548-549 , 51 - 59
  • Musolff, A., Schmidt, C., Selle, B., Fleckenstein, J. H., (2015): Catchment controls on solute export. Adv. Water Resources 86 , 133 - 146
  • Pinay, G., Peiffer, S., De Dreuzy, J.-R., Krause, S., Hannah, D.M., Fleckenstein, J. H., Sebilo, M., Bishop, K., Hubert-Moy, L., (2015): Upscaling nitrogen removal capacity from local hotspots to low stream orders’ drainage basins. Ecosystems 18 (6), 1101 - 1120
  • Liggett, J.E., Partington, D., Frei, S., Werner, A.D., Simmons, C.T., Fleckenstein, J. H., (2015): An exploration of coupled surface–subsurface solute transport in a fully integrated catchment model. J. Hydrol. 529 , 969 - 979
  • Frei, S., Fleckenstein, J. H., (2014): Representing effects of micro-topography on runoff generation and sub-surface flow patterns by using superficial rill/depression storage height variations. Environ. Modell. Softw. 52, 5 - 18
  • Koop, B.J., Fleckenstein, J. H., Roulet, N.T., Humphreys, E., Talbot, J., Blodau, C., (2013): Impact of long-term drainage on summer groundwater flow patterns in the Mer Bleue peatland, Ontario, Canada. Hydrol. Earth Syst. Sci. 17 (9), 3485 - 3498
  • Maier, U., Flegr, M., Rügner, H., Grathwohl, P., (2013): Long-term solute transport and geochemical equilibria in seepage water and groundwater in a catchment cross section. Environ. Earth Sci. 69 (2), 429 - 441
  • Schirmer, M., Leschik, S., Musolff, A., (2013): Current research in urban hydrogeology – a review. Adv. Water Resour. 51 , 280 - 291
  • Partington, D., Brunner, P., Frei, S., Simmons, C. T., Werner, A. D., Therrien, R., Maier, H. R., Dandy, G. C., Fleckenstein, J. H. (2013): Interpreting streamflow generation mechanisms from integrated
    surface-subsurface flow models of a riparian wetland and catchment Water Resour. Res. 49, 1–19
  • Jeong, J.-J., Bartsch, S., Fleckenstein, J. H., Matzner, E., Tenhunen, J.D., Lee, S.D., Park, S.K., Park, J.H., (2012): Differential storm responses of dissolved and particulate organic carbon in a mountainous headwater stream, investigated by high-frequency, in situ optical measurements. J. Geophys. Res. 117 , G03013
  • Leschik, S., Bayer-Raich, M., Musolff, A., Schirmer, M., (2011): Towards optimal sampling schedules for integral pumping tests. J. Contam. Hydrol. 124 (1-4), 25 - 34
  • Schirmer, M., Reinstorf, F., Leschik, S., Musolff, A., Krieg, R., Strauch, G., Molson, J. W., Martienssen, M., Schirmer, K., (2011): Mass fluxes of xenobiotics below cities: challenges in urban hydrogeology. Environ. Earth Sci. 64 (3), 607 - 617