DBPapers
DOI: 10.5593/SGEM2016/B31/S12.019

CHANGES OF WATER QUALITY OF LAKE HANCZA – ARE THE WATER RESOURCES OF THE DEEPEST LAKE OF THE CENTRAL PART OF EUROPEAN DEPRESSION THREATENED?

M. Lopata, D. Popielarczyk, T.Templin
Wednesday 7 September 2016 by Libadmin2016

References: 16th International Multidisciplinary Scientific GeoConference SGEM 2016, www.sgem.org, SGEM2016 Conference Proceedings, ISBN 978-619-7105-61-2 / ISSN 1314-2704, June 28 - July 6, 2016, Book3 Vol. 1, 137-144 pp

ABSTRACT
Lake Hańcza, the deepest inland reservoir in Poland, has steadily been losing its natural, oligotrophic character. The results of this study show that current accumulation of nutrients (nitrogen and phosphorus) locally reaches the eutrophic level.
Recommendations made on the basis of previous studies carried out only in the central part of the reservoir indicated that there is no risk of eutrophication of this beautiful, preserved lake. Our research is based on a multi-point (79 sampling points, the raw data collection supported by GNSS positioning), detailed study of water quality parameters, with geostatistical methods of spatial interpolation (kriging). We found significant differences in trophic conditions in examined parts of the lake. The largest variation concerns the main biogenic element - phosphorus. The average value was 0.032 at the extreme values of 0.019 to 0.265 mg L-1 (coefficient of variation 87%). Analysis of the spatial variability of studied parameters in relation to human pressure and pollution sources exposed a greater impact of catchment on the development of water quality than previously thought. Our results indicate that analyses of the trophic status evolution of such lakes should be based on the data, collected taking into account the local variation in water quality and external factors disrupting the uniformity of hydro-chemical conditions.

Keywords: water quality, aluminium, organic matter, lake restoration, water resources