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The influence of landscape on nutrient dynamics in rivers constitutes an important research issue because of its significance with regard to water and land management. In the current study spatial and temporal variability of N-NO3 and P-PO4 concentrations and their landscape dependence was documented in the Świder River catchment in central Poland. From April 2019 to March 2020, water samples were collected from fourteen streams in the monthly timescale and the concentrations of N-NO3 and P-PO4 were correlated with land cover metrics based on the Corine Land Cover 2018 and Sentinel 2 Global Land Cover datasets. It was documented that agricultural lands and forests have a clear seasonal impact on N-NO3 concentrations, whereas the effect of meadows was weak and its direction was dependent on the dataset. The application of buffer zones metrics increased the correlation performance, whereas Euclidean distance scaling improved correlation mainly for forest datasets. The concentration of P-PO4 was not significantly related with land cover metrics, as their dynamics were driven mainly by hydrological conditions. The obtained results provided a new insight into landscape–water quality relationships in lowland agricultural landscape, with a special focus on evaluating the predictive performance of different land cover metrics and datasets.

This study investigates the response of the streamflow to an extremely hot and dry summer 2015 in the urbanized catchment of the Utrata River in central Poland. The objectives were to: reveal changes in the flow regime, assess anomalies in summer river flows, estimate the natural and wastewater effluent contribution and provide an ecological context for the in-stream conditions. The mean annual flow rate in the period 1996-2015 increased by 0.61 m 3 /s as compared to 1951-1970. The mean annual wastewater inflow rate to the river in 2015 was approximately 0.770 m 3 /s, constituting 39% of the observed flow. Almost the entire period of August this contribution approached 100%. The optimum river water temperature threshold for warm-water fish species was exceeded. Streamflow modifications are attributed to an increase of wastewater discharge, urban impact through an increase in imperviousness, and the variability of climatic driving forces.Human-influenced streamflow during extreme drought U. Somorowska and M. Łaszewski

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Dynamic changes in stream water temperature are caused by thermal energy exchange at the interface between the water and the atmosphere, and between the water and the streambed. This heat flux is the result of physical processes which are stimulated by external drivers that control water temperature both in temporal and spatial scales. For streams, the most characteristic are diurnal fluctuations of temperature. For the purposes of this paper, electronic data loggers were used which allowed a presentation of the diurnal cycles of water temperature in a small lowland river. The measurements confirmed that meteorological conditions have a significant impact on the diurnal dynamics of stream temperature.