Tracing pollutant flow

Use of natural tracers to assess flow and pollutant transport to related ecosystems.

A close-up of the River Don, as taken from the river bank in Sheffield.

Project background

This project, carried out by University of Sheffield postgraduate student Tristan Ibrahim between 2007 and 2010, focused on groundwater and surface water interactions in the upper River Don. Research assessed the multi-scale control of hydro-geologic and geomorphic features on flow and solute patterns in riverbeds at the local scale.

Key findings

  • In the riverbed, local scale hyporheic flowpaths, driven by pool and riffle sequences, interact with large scale subsurface flowpaths, linked to the expansion and contraction of the alluvial valley.
  • These interactions control the depth of stream water infiltration in the riverbed, the mixing of stream and groundwater, as well as the degradation of organic matter by microbial communities.  Groundwater-dominated environments are temporally more stable; they also display large scale hydrochemical trends in the downstream direction.
  • In streamwater dominated environments, water exchange is primarily driven by riffle and pool sequences, and microbial activity varies seasonally.
A map of the area that postgraduate student Tristan carried out his study in.
© Crown Copyright/database right 2011. An Ordnance Survey/EDINA supplied service. River layer kindly licensed from the Environment Agency.

Additional details

Funding: This project was part of the EU funded Marie Curie project Catsci


  • Ibrahim, T.G., Lerner, D., Thornton, S.F. (2011). Integrating groundwater-surface water interactions in contaminated land context. Accepted for CL:AIRE Research Bulletins (
  • Wainwright, J., Ibrahim, T.G., Lexartza-Artza, I., Turnbull, L., Thornton, S.F. and Brazier, R.E. (2011). Linking environmental régimes, space and time: interpretations of structural and functional connectivity'. Geomorphology.
  • Ibrahim, T.G., Thornton, S.F. and Wainwright, J. (2010). Interplay of geomorphic and hydrogeologic features at reach- and channel unit-scales on riverbed hydrology and hydrochemistry: a conceptual model in the Lower Coal Measures, South Yorkshire, UK. Hydrogeology Journal, 18(6), 1391-1411.
  • Ibrahim, T.G., Käser, D., Ritchie, A. (2009). Measurements and monitoring at the groundwater-surface water interface. In: The Hyporheic Handbook. On-line publication of the Environment Agency (UK).
  • Buss, S., Cai, Z., Cardenas, B., Fleckenstein, J., Hannah, D., Heppell, K., Hulme, P., Ibrahim, T., Kaeser, D., Krause, S., Lawler, D., Lerner, D., Mant, J., Malcolm, I.,; Old, G., Parkin, G., Pickup, R., Pinay, G., Porter, J., Rhodes, G., Ritchie, A., Riley, J., Robertson, A., Sear, D., Shields, B., Smith, J., Tellam, J., Wood, P., 2009. The Hyporheic Handbook: A Handbook on the groundwater-surfacewater interface and hyporheic zone for environmental managers. Bristol, UK, Environment Agency.
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