New Methods & Models

We constantly seek to improve our method portfolio. New measuring and modeling techniques provide additional insight into into pattern and processes. For example, we develop an optical oxygen sensor which enables the unattended, repeated acquisition of time series of in situ oxygen profiles in water and sediment at a subcentimeter resolution covering a depth of up to one meter.

vieweg oxygen
Distributed oxygen sensor. (Vieweg et al. 2013, ES&T)


FLUX‐BOT (Water fluxes based on temperatures)

FLUX‐BOT is a MATLAB program to calculate vertical water fluxes in saturated sediments based on the inversion of measured temperature time series observed at multiple depths. FLUX‐BOT includes functions for the inverse numerical routines, functions for visualizing the results, and a function for performing uncertainty analysis. FLUX‐BOT can be downloaded here. Full documentation including a point‐by‐point instruction how to use FLUX‐BOT and a detailed description of all functions, the data structure and the incorporated input and output instructions is provided alongside with the program.

 Oxygen Sensor

Distributed Oxygen Sensor
The oxygen sensor  prior to installation in situ. Left panel: control unit. Right panels: side-firing POF in tubular oxygen probe. (source T.Brandt)


  • Brandt, T., Vieweg, M., Laube, G., Schima, R., Goblirsch, T., Fleckenstein, J.H., Schmidt, C., (2017):
    Automated in situ oxygen profiling at aquatic-terrestrial interfaces Environ. Sci. Technol. 51 (17), 9970 – 9978
  • Munz, M., Schmidt, C., (2017): Estimation of vertical water fluxes from temperature time series by the inverse numerical computer program FLUX-BOT Hydrol. Process. 31 (15), 2713 - 2724
  • Vandersteen, G., Schneidewind, U., Anibas, C., Schmidt, C., Seuntjens, P., Batelaan, O., (2015): Determining groundwater-surface water exchange from temperature-time series: Combining a local polynomial method with a maximum likelihood estimator. Water Resour. Res. 51 (2), 922 - 939
  • Schmidt, C., Büttner, O., Musolff, A., Fleckenstein, J.H., (2014): A method for automated, daily, temperature-based vertical streambed water-fluxes. Fundam. Appl. Limnol. 184(3), 173 - 181
  • Vieweg, M., Trauth, N., Fleckenstein, J.H., Schmidt, C., (2013): Robust optode-based method for measuring in situ oxygen profiles in gravelly streambeds. Environ. Sci. Technol. 47 (17), 9858 - 9865
  • Lewandowski, J., Angermann, L., Nützmann, G., Fleckenstein, J.H., (2011): A heat pulse technique for the determination of small-scale flow directions and flow velocities in the streambed of sand-bed streams. Hydrol. Process. 25 (20), 3244 - 3255
  • Munz, M., Oswald, S.E., Schmidt, C., (2011): Sand box experiments to evaluate the influence of subsurface temperature probe design on temperature based water flux calculation. Hydrol. Earth Syst. Sci. 15 (11), 3495 - 3510