Using reservoir sediment deposits to determine the longer-term fate of chernobyl-derived 137Cs fallout in the fluvial system

M M Ivanov; A V Konoplev; D E Walling; E A Konstantinov; A L Gurinov; N N Ivanova; N V Kuzmenkova; A S Tsyplenkov; M A Ivanov; V N Golosov

doi:10.1016/j.envpol.2021.116588

Using reservoir sediment deposits to determine the longer-term fate of chernobyl-derived ¹³⁷Cs fallout in the fluvial system

Environ Pollut. 2021 Apr 1:274:116588. doi: 10.1016/j.envpol.2021.116588. Epub 2021 Jan 24.

Authors

M M Ivanov¹, A V Konoplev², D E Walling³, E A Konstantinov⁴, A L Gurinov⁵, N N Ivanova⁶, N V Kuzmenkova⁷, A S Tsyplenkov⁶, M A Ivanov⁸, V N Golosov⁹

Affiliations

¹ Lomonosov Moscow State University, Faculty of Geography, Russia; Institute of Geography RAS, Russia. Electronic address: ivanovm@bk.ru.
² Fukushima University, Institute of Environmental Radioactivity, Japan.
³ University of Exeter, Department of Geography, United Kingdom.
⁴ Institute of Geography RAS, Russia.
⁵ Institute of Geography RAS, Russia; Department of Landscape Design and Sustainable Ecosystems, Agrarian-Technological Institute, RUDN University, Moscow, Russia.
⁶ Lomonosov Moscow State University, Faculty of Geography, Russia.
⁷ Lomonosov Moscow State University, Faculty of Chemistry, Russia.
⁸ Kazan Federal University, Institute of Ecology and Land-use Management, Russia.
⁹ Lomonosov Moscow State University, Faculty of Geography, Russia; Institute of Geography RAS, Russia; Kazan Federal University, Institute of Ecology and Land-use Management, Russia.

PMID: 33548668
DOI: 10.1016/j.envpol.2021.116588

Abstract

Vast areas of Europe were contaminated by the fallout of ¹³⁷Cs and other radionuclides, as a result of the Chernobyl accident in 1986. The post-fallout redistribution of Chernobyl-derived ¹³⁷Cs was associated with erosion and sediment transport processes within the fluvial system. Bottom sediments from lakes and reservoirs can provide a valuable source of information regarding the post-fallout redistribution and fate of ¹³⁷Cs released by the Chernobyl accident. A detailed investigation of sediment-associated ¹³⁷Cs in the bottom sediments of a reservoir in a Chernobyl-affected area in Central Russia has been undertaken. A new approach, based on the vertical distribution of ¹³⁷Cs activity concentrations in the reservoir bottom sediment makes it possible to separate the initially deposited bottom sediment, where the ¹³⁷Cs activity reflects the direct fallout of Chernobyl-derived ¹³⁷Cs to the reservoir surface and its subsequent incorporation into sediment deposited immediately after the accident, from the sediment mobilized from the catchment deposited subsequently. The deposits representing direct fallout from the atmosphere was termed the "Chernobyl peak". Its shape can be described by a diffusion equation and it can be distinguished from the remaining catchment-derived ¹³⁷Cs associated with sediment accumulated with sediments during the post-Chernobyl period. The ¹³⁷Cs depth distribution above the "Chernobyl peak" was used to provide a record of changes in the concentration of sediment-associated ¹³⁷Cs transported from the upstream catchment during the post-Chernobyl period. It was found that the ¹³⁷Cs activity concentration in the sediment deposited in the reservoir progressively decreased during the 30-year period after the accident due to a reduction in the contribution of sediment eroded from the arable land in the catchment. This reflects a reduction in both the area of cultivated land area and the reduced incidence of surface runoff from the slopes during spring snowmelt due to climate warming.

Keywords: (137)Cs; Bottom sediment; Chernobyl; Post-fallout redistribution of (137)Cs; Schekino reservoir.

MeSH terms

Cesium Radioisotopes / analysis
Chernobyl Nuclear Accident*
Europe
Geologic Sediments
Radiation Monitoring*
Radioactive Fallout* / analysis
Russia
Water Pollutants, Radioactive* / analysis

Substances

Cesium Radioisotopes
Radioactive Fallout
Water Pollutants, Radioactive
Cesium-137