Towards a multi-basin SWAT model for the migration of nutrients and pesticides to Puck Bay (Southern Baltic Sea)

Paweł Wielgat; Dominika Kalinowska; Adam Szymkiewicz; Piotr Zima; Beata Jaworska-Szulc; Ewa Wojciechowska; Nicole Nawrot; Karolina Matej-Lukowicz; Lidia Anita Dzierzbicka-Glowacka

doi:10.7717/peerj.10938

Towards a multi-basin SWAT model for the migration of nutrients and pesticides to Puck Bay (Southern Baltic Sea)

PeerJ. 2021 Feb 25:9:e10938. doi: 10.7717/peerj.10938. eCollection 2021.

Authors

Paweł Wielgat¹, Dominika Kalinowska¹, Adam Szymkiewicz¹, Piotr Zima¹, Beata Jaworska-Szulc¹, Ewa Wojciechowska¹, Nicole Nawrot¹, Karolina Matej-Lukowicz¹, Lidia Anita Dzierzbicka-Glowacka²

Affiliations

¹ Faculty of Civil and Environmental Engineering, Gdansk University of Technology, Gdańsk, Poland.
² Institute of Oceanology of the Polish Academy of Sciences, Sopot, Poland.

Abstract

Background: This paper analyzes the impact of changes in fertilization on crop yields and the runoff of nutrients from a small agricultural catchment (176 km²) to a shallow bay, using the SWAT model. Puck Bay is part of the Gulf of Gdansk and belongs to the Baltic Sea. The whole area of Puck Bay (364 km²) is protected (Natura 2000) yet despite this it suffers from eutrophication problems due to the relatively minimal depth and difficult water exchange.

Methods: The paper presents a comparison of the calculated yields and the runoff of nutrients and pesticides in the SWAT model, for a small agricultural coastal catchment. Calculations were made for 13 crop scenarios with weather data from 2011 to 2019. For each crop, an agriculture calendar was made. Two variants of fertilization were considered (autofertilization mode and according to the calendar). The nutrient runoff was calculated depending on the adopted scenario. In addition, the fate of selected pesticides was simulated.

Results: Depending on the crop, the annual load of NO₃into the stream ranged from 0.74 to 3.65 kg ha^-1. The annual load of organic phosphorous into the stream was between 0.686 and 3.64 kg ha^-1. This is lower than in the majority of EU or Baltic countries. The surface runoff of dissolved Glyphosate was equal to 286 mg ha^-1. The annual loads of nutrients from the catchment area are equivalent in both fertilization modes. Regardless of the selected fertilization mode, in addition to the dosage, the form of nutrients is important for the model.

Keywords: Baltic eutrophication; WaterPUCK project; catchment hydrology; fertilizer; land use change; nutrient runoff; pesticide runoff; Puck Bay; SWAT model.

Grants and funding

The work was funded by the National Centre for Research and Development (NCBR), Poland, in the framework of the project BIOSTRATEG3/343927/3/NCBR/2017 “Modelling of the impact of the agricultural holdings and land-use structure on the quality of inland and coastal waters of the Baltic Sea set up on the example of the Municipality of Puck region—Integrated info-prediction Web Service Water PUCK”—BIOSTRATEG Program. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.