Maria Vitalievna Evdokimova

The theoretical equation, based on the trace elements concentration in the soil as a function of depth and time, was deduced and tested on the experimental data on long-term dynamics of some heavy metals (copper, nickel, manganese) in soils of Moscow State University lysimeters under different types of vegetation.

The theoretical equation of the concentration of trace element compounds entering the soil with atmospheric precipitation as a function of depth and time is tested on the example of data on the long-term dynamics (1965, 1995, 2006, and 2013) of Cu, Ni and Mn compounds in the soil profile under artificial phytocenoses of the MSU soil lysimeters. The obtained results indicate the possibility of using an analytical model for predicting the content of heavy metals in the soil profile.

Spatial and temporal variability of the vegetation index were investigated in the vicinity of the anthropogenic source of heavy metals. The analysis of the special points of the theoretical equation of the dependence of the concentration of photosynthetically active biomass on the resulting concentration of pollutants in the soil revealed the maximum permissible concentration of heavy metals in the soil. The results of its determination in the northern forest-steppe under the current level of anthropogenic pressure, according to MODIS materials, amounted to 12,3, according to Sentinel-2 — 12,5 mg/kg, respectively. A method for generalizing the macrokinetic patterns of the response of the living organisms to anthropogenic impact is proposed. The results of the environmental risk assessment showed that the probability of exceeding the threshold concentration is 74%.

Based on the five-level quality scale and the indicator of soil state, the quality of soils and vegetation cover was ranked. The areas of the same resistance of soils and vegetation to the action of pollutants in the plant impact zone were mapped. Territories near the plant mostly correspond to the I and II categories of soil quality. The natural protection zone of the enterprise is allocated, and background territories are defined.

As part of the study of the ecological state of soils and vegetation in the zone of impact of the Sredneuralsky Copper Smelter (SUMZ), the following tasks were solved: the content of heavy metals in the soils of the test sites laid within the zone of impact of the SUMZ was determined; macrokinetic patterns of seasonal dynamics of the normalized relative vegetation index (NDVI) at the test sites in the zone of impact of the SUMZ were revealed; macrokinetic patterns of vegetation response in the form of NDVI, calculated according to MODIS and Landsat 8 data, to soil pollution by a complex of heavy metals in the zone of impact of the SUMZ were revealed; soil quality was ranked according to the patterns of vegetation response in the form of NDVI to soil pollution by a complex of heavy metals within the boundaries of the natural protection zone (NZZ) of the SUMZ according to 2023.

The intra-seasonal dynamics of photosynthetically active biomass in the form of NDVI was modeled using a theoretical growth equation based on MODIS satellite data. The seasonal maximum of the vegetation index at the trial sites in 2012 fell on the 25‒28 week. In 2023, it occurred on the 27‒33 week, depending on the location of the sampling point. The rate of maximum achievement is characterized by weak intra-seasonal and interannual variation.

The patterns of changes in the concentration of photosynthetically active biomass in the form of maximum NDVI for the 2023 season in response to the gross content of a complex of heavy metals (Cu, Pb, Cd and Zn) in the soil of the test sites were modeled using the theoretical equation of dose dependence. The maximum permissible level of the heavy metal complex in the soil in the form of a geometric mean, which does not cause a decrease in the values of the vegetation index calculated according to the data of the MODIS and Landsat 8 satellites, was 101 and 106 mg×kg^-1, respectively.

The analysis of histograms of the distribution of NDVI values within the NZZ was carried out, which showed how the true frequencies of occurrence of the values of the vegetation index correspond to the empirical boundary of the NZZ associated with the maximum dose dependence point identified by the study of the 2012. The nature of the distribution of true NDVI values for the NZZ exclusively fully supports the used zoning theory based on the analysis of dose dependence. The modern boundaries of the SUMZ natural protection zone are 4‒7 km away from the center of the sanitary protection zone.