Vitaly G. Linnik

Preferential vertical water flows play a significant role in water movement within the soil profile; while lateral flows attract less attention from resear

The results of the landscape-radioecological monitoring and geoinformation modeling of the distribution of 137Cs in the Predpolesie landscapes (Vy

Regularities of the spatial distribution of 137Cs in forest soil at the microlandscape level in semihydromophic and hydromorphic conditions of Bryansk obla

Assessment of spatial patterns of potentially toxic metals is one of the most urgent tasks in soil chemistry. In this study, descriptive statistics and three methods of multivariate statistical analysis, such as the hierarchical cluster analysis (HCA), correlation analysis, and conditional inference tree (CIT), were used to identify patterns and potential sources of heavy metals (Co, Ni, Cu, Cr, Pb, MnO, and Zn). The investigation was carried out on 81 sample points, using 20 testing parameters. A strong positive correlation found among Ni, Cu, Zn, and HCA results has confirmed the common origin of the elements from waste discharge. Hierarchical CA divided the 81 test sites into 5 classes based on the soil quality and HMs contamination similarity. Regression trees for Cr, Pb, Zn, and Cu were verified by the splitting factor including HMs content and soil chemistry factors. The CIT has revealed that the elements (Cr, Pb, Zn, and Cu) concentration values are split at the first level by some other metal, indicating common anthropogenic impact resulting from industrial waste discharges. The factors at the next hierarchical level of splitting, in addition to the HMs, include compounds belonging to soil chemistry variables (SiO₂, Al₂O₃, and K₂O). The CIT nonlinear regression model is in good agreement with the data: R² values for log-transformed concentrations of Cr, Pb, Zn, and Cu are equal to 0.775; 0.774; 0.775; 0.804, respectively.

The paper presents data on the vertical distribution of ¹³⁷Cs of Chernobyl origin in arable and meadow soils to a depth of 40 cm in typical catenary junctions of predpolessie, predopolje, and opolje landscapes with a different density of ¹³⁷Cs contamination 30 years after the accident at the Chernobyl nuclear power plant. Newly obtained data on the removal of ¹³⁷Cs beyond the arable horizon presented in the paper indicate that this parameter varies depending on the landscape conditions: it varies in the range of 2.7–17.7% in predpolessie landscapes and in the range of 0.5 to 9% in opolje landscapes. In opolje landscapes, the coefficient of ¹³⁷Cs removal from the arable horizon was proved to systematically decrease depending on the landscape catenary position: it amounts to 8.5% in the transit zone and is 1.4% in the accumulation zone. The vertical distribution of ¹³⁷Cs and ²¹⁰Pb_ex (excess) in the sod and floodplain soils in the basin of the Kostitsa River was studied to determine the sedimentation rate. Based on the analysis of the distribution of ¹³⁷Cs in the soil, the sedimentation rate over the past 30 years in various parts of the floodplain was estimated at 0.42 ± 0.08 to 0.58 ± 0.11 cm/year. The average estimated sedimentation rate in the floodplain during approximately 50 past years was, according to the ²¹⁰Pb_ex dating was equal to 0.7 ± 0.18 cm/year. The sedimentation rate in the bottom of a ravine was evaluated for sod soils based on the distribution of ²¹⁰Pb_ex according to the CRS model for 1961–2016 y. It was revealed that the minimum sedimentation rate of 0.24 cm/year occurred in 1961–1988, and the maximal (0.7 cm/year) in 2000 to 2007.

Soil contamination by heavy metals (HM) is a worldwide problem for human health. To reduce risk to human health from exposure to toxic chemicals associated with soil contamination, it is necessary to monitor and assess HM concentrations in the soil for places where the concentration exceeds the acceptable levels. Spatial patterning is a necessary tool for assessment of the exposure risk of HM contamination. Soil sampling (n = 65) was carried out in technogenically polluted soils located at Rostov oblast to study the content and spatial distribution of four HM (Cu, Zn, Pb, and Cr) in the surface layer (0–20 cm) of the impact zone of former Lake Atamanskoe (floodplain of the Seversky Donets River valley, Rostov region) with an area of 3.91 km². Extremely high values of HM concentrations were found with the maximum values of 702 mg/kg, 72,886 mg/kg, 2300 mg/kg, 259 mg/kg for Cu, Zn, Pb, and Cr, respectively. Inverse distance-weighted (IDW) interpolation was used to prepare 3D monoelement images of HM. Lognormal kriging and indicator kriging techniques were applied to create elemental spatial distribution maps and HM probability maps. The results showed that the total content of Cu, Zn, Pb, and Cr was moderately spatially dependent (nugget-to-sill ratio ranged from 31 to 38%), whereas the contamination index Zc formed strong spatial dependence patterns (nugget-to-sill ratio ranged from 0 to 21.4%). The obtained results of this study could serve as a guide to the authorities in identifying those areas which need remediation. Moreover, this study provides a tool for assessing the hygienic situation in the vicinity of Kamensk-Shakhtinsky (Rostov region) for decision making that can help to minimize the environmental risk of technogenic soil contamination of HM.

—The paper presents the ecological-geochemical studies of soils confined to the impact zone of industrial waste water storage and sludge reservoirs of former Lake Atamanskoe in the Seversky...