Assessment of the input of heavy metals and arsenic with sediments to armable land of the floodland agrolandscape of the Oka river

The purpose of the research is an environmental assessment of the impact of flood sedimentation on arable lands of the agricultural landscape of the river floodplain Oka. Research to study the supply of pollutants as part of flood sediments to arable lands of a floodplain agricultural landscape was carried out in 2022 at a stationary observation site with an area of 16 hectares, located 2 km from the north-eastern administrative border of the city of Ryazan, Ryazan region (the left bank of the central part of the floodplain of the river Oka near the village of Shumash). The study of sediment load was carried out by sampling sediments using fleecy plastic mats installed in advance (before the onset of the spring flood), simulating the soil cover on top (mat area 0.14 m2). The magnitude of the sediment load was experimentally established, the content of pollutants in flood sediments was studied in comparison with the underlying soil, the degree of contamination of sediments with heavy metals and arsenic was assessed, and the structure of the entry of the studied chemical elements into the agricultural landscape with flood sediments was analyzed. Analysis of the calculated element concentration coefficients showed that, of the pollutants considered, cadmium is more actively concentrated in flood sediments at the stationary observation site, followed by zinc, mercury, arsenic, nickel and lead with a significant lag, and copper and chromium accumulate less actively. The intake of gross forms of heavy metals was: copper – 238.58 g/ha; zinc – 1501.0 g/ha, lead – 271.76 g/ha; cadmium – 103.65 g/ha; nickel – 472.4 g/ha; chromium – 477.16 g/kg; mercury – 0.46 g/ha; arsenic – 143.9 g/ha. The entry of pollutants in the process of sedimentogenesis into the agricultural landscape in the floodplain of the river Oki demonstrates the need to organize and conduct environmental monitoring of the content of heavy metals and arsenic in flood sediments and underlying soil, as well as preventive measures to improve its buffer properties.