Open AccessWater Suspension and its Effect on Total Light Attenuation in Lake Waters
Author(s) -
Olga Akulova,
В. И. Букатый,
V. I. Kirillov,
O.M. Frolenkov
Publication year - 2021
Publication title -
izvestiâ altajskogo gosudarstvennogo universiteta
Language(s) - English
Resource type - Journals
eISSN - 1561-9451
pISSN - 1561-9443
DOI - 10.14258/izvasu(2021)4-01
Subject(s) - attenuation , eutrophication , suspension (topology) , environmental science , wavelength , turbidity , radius , hydrology (agriculture) , chemistry , physics , optics , oceanography , geology , nutrient , mathematics , computer security , organic chemistry , geotechnical engineering , homotopy , computer science , pure mathematics
The paper presents the data obtained by the authors in 2012-2021 during field trips to freshwater reservoirs of Altai Krai. According to hydro-optical measurements, values of light attenuation index in the range of 400-800 nm calculated using the natural logarithm varied greatly within 2.3-19.7 m-1 and 2.9-35.0 m-1 in the surface layer of lakes Lapa and Krasilovskoye during the study period. The relative spectral contribution of water suspension and contributions of yellow matter, chlorophyll, and pure water constituents at wavelengths of 430, 550, and 670 nm were estimated to assess the optical effect of water suspension on the total light attenuation index. The calculation results demonstrated that water suspension had the maximum effect on light attenuation in waters of eutrophic lake Lapa during the autumn-winter period. The maximum effect at all three wavelengths was observed in autumn of 2015, and the contribution of water suspension to light attenuation reached 88.5%, whereas its minimum (1.8-2.4 %) was recorded in 2017. The maximum contribution of water suspension on light attenuation in waters of eutrophic-hypereutrophic lake Krasilovskoye slightly exceeded the value of 70% during the winter of 2014. The next maximums were revealed during the spring of 2014 and had values of 71.3 % at λ =430 nm and 71.1 % at λ =550 nm.
Optical microscopy was used to estimate the size and concentration of water suspense particles. The average weighted value of radius for water suspense particles in the surface layer of lakes Lapa and Krasilovskoye was found to be 1.2 and 1.4 microns, respectively. The average particulate count for water suspense during the observation period varied in the range of 0.2·106 cm-3-14.7·106 cm-3 with values of 3.3·106 cm-3 for lake Lapa and 3.0·106 cm-3 for lake Krasilovskoye.