@ARTICLE{Kubiak_Jacek_Long_2021, author={Kubiak, Jacek and Machula, Sylwia and Czerniejewski, Przemysław and Brysiewicz, Adam and Wawrzyniak, Wawrzyniec}, number={No 51}, pages={30-37}, journal={Journal of Water and Land Development}, howpublished={online}, year={2021}, publisher={Polish Academy of Sciences; Institute of Technology and Life Sciences - National Research Institute}, abstract={In 1970–2010, during the period of spring circulation and summer stagnation, hydrochemical studies were conducted in Lake Ińsko (Western Pomeranian Lake Region, Poland) with determination of the lake susceptibility to degradation and trophic changes. Also, the effect of the catchment area on the water quality in this waterbody was assessed. The waters of the study lake were characterised by low static index, which is an additional indicator of low dynamics of water masses, and low susceptibility to degradation. In spite of this, significant changes in the lake quality and trophy were observed. The hydrochemical parameters defining water quality of the study lake continued to improve. In the 70’s, the water quality was at the border of class II and III, while in 2006 and 2010 it reached the level characteristic for class I waters. Moreover, in the 70’s and 80’s of the previous century, Lake Ińsko Duże was a mesotrophic lake. Then, an increase in the lake trophy was observed, resulting in signs of eutrophy. At the end of the 90’s and in the first decade of the 21st century, the study lake returned to the state of mesotrophy. No restoration works were undertaken in Lake Ińsko in the study period. The improvement in water quality, called oligotrophication, resulted most probably from the lake reaction to changes in the soil use in the catchment area, since fewer phosphorus and nitrogen compounds flow into the lake, and also from the regulation of the wastewater management in the town of Ińsko.}, type={Article}, title={Long term changes in the quality and water trophy of Lake Ińsko – the effect of the re-oligotrophication?}, URL={http://www.journals.pan.pl/Content/122145/PDF/2021-04-JWLD-05-Kubiak.pdf}, doi={10.24425/jwld.2021.139012}, keywords={Lake Ińsko, oligotrophication, susceptibility to degradation, trophy, water quality}, }