Water and nutrient sources in a short stream reach

This work stems from several years of research conducted in a medium size lowland catchment of the groundwater-fed Kocinka River in Poland that aimed at quantification of sources and transformations of nitrate pollution. Deconvolution of nitrate sources and transformations at the catchment scale appeared to be difficult because of the mostly diffuse character of groundwater inflows with diverse concentrations of nitrate. Additionally, the hydromorphological characteristics that may affect riverine nutrient cycling change significantly along the river. Therefore, a short, 2.6 km long reach of the upper Kocinka was selected for a more detailed study. This reach is representative of small, channelized streams in urbanized rural areas that receive loads of nutrients and other contaminants from various, often episodic, sources such as farmyard, urban and road runoff, sewage and wastewater disposal, fish ponds. Isotopic compositions of water and nitrate. temperature of water as well as drone-based thermal images were used to characterize sources of streamflow and nitrate. Tracer experiment with tritium and the radioactive phosphorus isotope (³²P) provided insights [1] into the significance of transient storage zones in solute transport and the extent of phosphorus removal.

The research has been partially financed from the funds of the "Excellence Initiative - Research University" program at AGH University of Science and Technology.

[1] Zieba, D., & Wachniew, P. (2021). Phosphorus Transport in a Lowland Stream Derived from a Tracer Test with 32P. Water 2021, 13, 1030.