Selenium accumulation in the landscapes of Tyumen city (the case of Kalininsky administrative district)

Abstract

The aim of the study was to investigate peculiarities of Selen accumulation in the Tyumen City landscapes (on the territory of Kalininsky Administrative District). Location and time of the study. The study was conducted in the summer of 2022 on the 2nd supra floodplain terrace of the Tura River in the vicinity of the Meteleva microdistrict, as well as on the gully slope of the Babarynka River in Tyumen. Methods. Methods of geological and soil studies, chemical and statistical methods were used to analyze selenium content in alluvial sediments and its vertical and lateral migration along a slope. Main results. Selenium content was found to change irregularly with the depth both in the alluvial deposits of the 2nd above-floodplain terrace of the river in the area of the Metelev microdistrict and in the soil profile of the Babarynka River slope, varying from 0.015 to 0.053 mg/kg and from 0.01 to 0.09 mg/kg, respectively, and being below the MPC values (according to A. Kloke of 10 mg/kg) and the Clark value of 0.15 mg/kg, proposed by N.A. Grigoriev. Selenium content in meadow-chernozem and loess-loamy soils of Tyumen was not correlated with the soil organic matter content. Conclusion. Selenium content and distribution in the alluvial Quaternary sediments of the 2nd supra floodplain terrace of the Tura River is influenced by many factors, the most important being sediment mineralogy and mechanical properties, as well as conditions of sediment formation in the past. The lateral migration of selenium in landscape components is influenced by the intensity of occurring geomorphologic processes, resulting in selenium accumulation and dispersion.