Determination of the trophic status of the water reservoir and spatial distribution of aquatic vegetation by integral indicators
Kutyavina T. I., Rutman V. V., Ashikhmina T. Y.
Section: Research methods. Models and projects
Determination of the trophic status of a reservoir is necessary for making decisions on the use of a water body for industrial production and domestic purposes. The calculation of the trophic state index (ITS) of a reservoir based on measuring the value of the hydrogen index and the content of dissolved oxygen in water allows us to evaluate the trophic state of a water body, regardless of its type and region of study. According to the results of the physicochemical analysis of water for 2011–2019, the dependence of pH on the degree of oxygen saturation of water was established for one of the largest reservoirs in the Kirov region (Omutninsky reservoir) which is subjected to eutrophication. Based on the dependence found, the ITS index of the reservoir was calculated. Over 9 years of observations, ITS increased from 7.8 to 8.1 units, which indicates the transition of the Omutninsk reservoir from the mesotrophic to the eutrophic type. Using the Earth remote sensing methods for the reservoir, areas of mass development of phytoplankton and higher aquatic plants have been identified. Field observations in these areas revealed thickets of Equisetum fluviatile L., Scirpus lacustris L., Persicaria amphibia (L.) S. F. Gray, Rotamogeton lucens L. The data obtained by calculating the turbidity index and the concentration index of chlorophyll a in water are consistent with field data observations and can be further used in environmental monitoring of the Omutninsk reservoir and other reservoirs in the region.
Keywords: eutrophication, algae “bloom”, dissolved oxygen, index of trophical state, Earth remote sensing, Sentinel-2, turbidity index, chlorophyll а concentration index
Article published in number 1 for 2020 DOI: 10.25750/1995-4301-2020-1-042-046