Precipitation in open space is one of the stages of the water cycle representing an element of “entry” into the geoecosystem. Rainfall supplies various pollutants from the atmosphere to the ground, with these including dissolved chemical components. This makes it important for selected physicochemical parameters to be quantified at this stage of the water cycle, in order for processes taking place in the natural environment more widely to be properly elucidated.
The research detailed here was conducted over 5 hydrological years (2016‑2020 inclusive) within the borders of the urban catchment of the Różany Strumień stream flowing through the northern part of the large Polish city of Poznań. The natural environment of the Różany Strumień catchment is characterised by significant transformations due to human activity. Key environmental problems here include threats relating to the pollution of surface waters and groundwater, as a result of processes associated with the functioning of the urban catchment.
The main aim here is to present the level of supply into the catchment of pollutants, and to determine the temporal variability of matter circulation in this small urban catchment, in years with different pluvial conditions, and therefore quantitatively variable atmospheric supply to the geoecosystem.
Levels of supply of pollutants into the catchment were determined through systematic and comprehensive measuring of the natural environment. The measurement system and field-research methodology relate to the methodological concept of system functioning, as well as the assumptions of Poland’s Programme of Integrated Monitoring of the Natural Environment (IMNE).
Results for the measurement of several different environmental components are presented, beginning with core meteorological conditions (precipitation and air temperature). The average annual air temperature in all 5 analysed years was higher than the long-term average for the IMGW-PIB Poznań-Ławica Station over the 1981‑2010 period, equal to 8.8°C. The coldest year was 2017 with an average annual air temperature of 9.3°C; in turn, the warmest years were 2019 and 2020 (the average annual air temperature was 10.7°C). Atmospheric water supply to the catchment area was much smaller in the dry years 2018‑2019 and equaled to 437.8 mm and 467.5 mm, respectively. The year 2017 was the wettest (744.2 mm), exceeding the average total monthly precipitation from the long-term period 1981‑2010 by 222 mm. In the remaining two years, total annual precipitation was 652.5 mm (2016) and 592.8 mm (2020).
Further elements of the research relate to air pollution with SO2 and NO2, as well as to the chemical composition of precipitation considered to enter the geoecosystem. The permissible concentrations of sulfur dioxide (20 μg·m-3) and nitrogen dioxide (40 μg·m-3) were not exceeded in any of the analysed year. The highest monthly concentrations were recorded in the winter half-year, which was caused by the heating season and the burning of fossil fuels. At the beginning of the analysed five-year period, an increase indicators of participation of acidic factors in acidulating precipitations (defined as the ratio of the weighted average concentrations of NO3- and SO42-) was observed. In turn, in 2020, this indicator decreased again and was the lowest in the years 2016‑2020. This indicates a lower share of nitrates and a greater share of sulphates in precipitation.
Precipitation in the Różany Strumień catchment is characterised by relatively low mineralisation and normal pH. The average atmospheric deposition (loads) in the analysed five-year period was 2800 kg∙km-2; with an average annual precipitation total of 578.4 mm. The lowest atmospheric deposition of 2200 kg∙km-2 was recorded in 2019 (with an annual precipitation total of 467.5 mm), and the highest 3500 kg∙km-2 in 2017 (with an annual precipitation of 741.4 mm).
Further findings concern physicochemical properties (i.a. levels, flows and chemical composition) of surface waters and groundwater. Highest water level and also water flow, were recorded directly after daily precipitation totals < 20 mm. Favorable rainfall conditions in 2016‑2017 had a positive effect on the water flows, as the highest ones occurred in the Różany Strumień in wet a 2017 and at the beginning of 2018. The Różany Strumień waters were characterised by a slightly alkaline pH (8.0) and high mineralisation (SEC = 88.6 mS·m-1) in the 2016‑2020 period. The high value of SEC was related, among others, to anthropogenic transformations in the catchment area (land use changes, deforestation for urbanization and agricultural purposes), as well as the supply of polluted water to watercourses or surface runoff from agricultural areas.
The denudation balance was also determined. In lowland regions, chemical denudation processes outweigh mechanical denudation processes. In the analysed catchment there is a positive balance of biogenic ions and ions supplied by human activity (e.g. through fertiliser use) – NO3-, NH4+ and K+. Other chemical components (denudation ions) occurring in the waters circulating in the catchment are characterized by a negative balance.
The denudation balance analysis of the Różany Strumień catchment can serve as a good indicator of anthropopressure, and especially the excessive supply of the natural environment in nutrients (from both fertilisers and domestic pollutants).
Maciej Major [firstname.lastname@example.org], Uniwersytet im. Adama Mickiewicza w Poznaniu, Stacja Zintegrowanego Monitoringu Środowiska Przyrodniczego „Poznań-Morasko”
Maria Chudzińska [email@example.com], Uniwersytet im. Adama Mickiewicza w Poznaniu, Stacja Zintegrowanego Monitoringu Środowiska Przyrodniczego „Poznań-Morasko”
Mikołaj Majewski [firstname.lastname@example.org], Uniwersytet im. Adama Mickiewicza w Poznaniu, Stacja Zintegrowanego Monitoringu Środowiska Przyrodniczego „Poznań-Morasko”
APA: Major, M., Chudzińska, M., & Majewski, M. (2022). Wielkość dostawy wybranych zanieczyszczeń atmosferycznych i ich wpływ na jakość wód w zurbanizowanej zlewni Różanego Strumienia w Poznaniu w latach hydrologicznych 2016‑2020. Przegląd Geograficzny, 94(4), 415-436. https://doi.org/10.7163/PrzG.2022.4.1
MLA: Major, Maciej, et al. "Wielkość dostawy wybranych zanieczyszczeń atmosferycznych i ich wpływ na jakość wód w zurbanizowanej zlewni Różanego Strumienia w Poznaniu w latach hydrologicznych 2016‑2020". Przegląd Geograficzny, vol. 94, no. 4, 2022, pp. 415-436. https://doi.org/10.7163/PrzG.2022.4.1
Chicago: Major, Maciej, Chudzińska, Maria, and Majewski, Mikołaj. "Wielkość dostawy wybranych zanieczyszczeń atmosferycznych i ich wpływ na jakość wód w zurbanizowanej zlewni Różanego Strumienia w Poznaniu w latach hydrologicznych 2016‑2020". Przegląd Geograficzny 94, no. 4 (2022): 415-436. https://doi.org/10.7163/PrzG.2022.4.1
Harvard: Major, M., Chudzińska, M., & Majewski, M. 2022. "Wielkość dostawy wybranych zanieczyszczeń atmosferycznych i ich wpływ na jakość wód w zurbanizowanej zlewni Różanego Strumienia w Poznaniu w latach hydrologicznych 2016‑2020". Przegląd Geograficzny, vol. 94, no. 4, pp. 415-436. https://doi.org/10.7163/PrzG.2022.4.1