The aim of this study is to determine the spatial distribution of geochemical anomalies of selected potential toxic elements in the soils of the river basins in the Northeastern Caucasus—specifically the Ulluchay, Sulak, and Sunzha Rivers. A concentration of 25 chemical elements was measured using inductively coupled plasma mass spectrometry (ICP-MS). Petrogenic elements commonly found in the Earth’s crust (Al, Na, Ca, Fe, Mg) showed high concentrations (Na up to 306,600.70 mg/kg). Conversely, concentrations of Ag, Cd, Sn, Sb, and Te at many sampling sites were extremely low, falling below the detection limits of analytical instruments. The geochemical indicators Cf (contamination factor) and Igeo (geoaccumulation index) indicate that the regional characteristics of the territory, such as lithological conditions, hydrochemical schedules, and the history of geological development of the territory, affect the concentration of elements. Anomalous concentrations were found for seven elements (Ba, Na, Zn, Ag, Li, Sc, As), whereas no anomalies were identified for Be, Mg, Al, Mn, Fe, Co, Ni, Cu, Pb, Te, and Cs. For the most part (8 of 10), the sampling sites with anomalous chemical element content are located in the basin of the Sunzha River. Two sites with anomalous chemical element content have been identified in the Sulak River Basin. Anomalous values in the Sulak River Basin are noted for two chemical elements—Ba and Na. Natural features such as geological structure, parent rock composition, vertical climatic zonation, and landscape diversity play a major role in forming geochemical anomalies. The role of anthropogenic factors increases in localized areas near settlements, industrial facilities, and roads. The spatial distribution of geochemical anomalies must be considered in agricultural management, the use of water sources for drinking supply, the development of tourist routes, and comprehensive spatial planning.

The Caspian region represents a complex and unique system of terrestrial, coastal, and aquatic environments, marked by an exceptional landscape and biological diversity. This diversity, however, is increasingly threatened by substantial anthropogenic pressures. One notable impact of this human influence is the rising concentration of pollutants atypical for the atmosphere. Advances in science and technology now make it possible to detect certain atmospheric pollutants using remote Earth observation techniques, specifically through data from the Sentinel-5 satellite, which provides continuous insights into atmospheric contamination. This article investigates the dynamics of atmospheric pollution in the southwestern part of the Caspian Sea basin using Sentinel-5P satellite data and the cloud-computing capabilities of the Google Earth Engine (GEE) platform. The study encompasses an analysis of concentrations of seven key pollutants: nitrogen dioxide (NO₂), formaldehyde (HCHO), carbon monoxide (CO), ozone (O₃), sulfur dioxide (SO₂), methane (CH₄), and the Aerosol Index (AI). Spatial and temporal variations in pollution fields were examined for the Caspian region and the basins of the seven rivers (key areas) flowing into the Caspian Sea: Sunzha, Sulak, Ulluchay, Karachay, Atachay, Haraz, and Gorgan. The research methodology is based on the use of data from the Sentinel-5 satellite, SRTM DEM data on absolute elevations, surface temperature data, and population density data. Data processing is performed using the Google Earth Engine cloud-computing platform and the ArcGIS software suite. The main aim of this study is to evaluate the spatiotemporal variability of pollutant concentration fields in these regions from 2018 to 2023 and to identify the primary factors influencing pollution distribution. The study’s findings reveal that the Heraz and Gorgan River basins have the highest concentrations of nitrogen dioxide and Aerosol Index levels, marking these basins as the most vulnerable to atmospheric pollution among those assessed. Additionally, the Gorgan basin exhibited elevated carbon monoxide levels, while the highest ozone concentrations were detected in the Sunzha basin. Our temporal analysis demonstrated a substantial influence of the COVID-19 pandemic on pollutant dispersion patterns. Our correlation analysis identified absolute elevation as a key factor affecting pollutant distribution, particularly for carbon monoxide, ozone, and aerosol indices. Population density showed the strongest correlation with nitrogen dioxide distribution. Other pollutants exhibited more complex distribution patterns, influenced by diverse mechanisms associated with local emission sources and atmospheric dynamics.

Objectives: The objectives of this research include assessing the concentrations of heavy metals and trace elements in the Fatala River basin (Republic of Guinea), identifying the primary sources of these pollutants, analyzing their migration patterns, evaluating the ecological and health impacts, and contributing to the development of effective pollution mitigation strategies. The theoretical framework is grounded in understanding the anthropogenic impact on soil, the role of soil as a natural filter, the associated health risks, and the application of Geographic Information Systems (GIS) for detailed pollution analysis. Theoretical Framework: Pollution from heavy metals and trace elements presents a significant threat to environmental health, a situation that has been exacerbated with the expansion of mining and industrial activities. Despite advancements in technology aimed at reducing soil contamination, many regions, particularly in developing countries, continue to experience unchecked pollution due to the lack of environmental safeguards. This study focuses on the Fatala River basin in the Republic of Guinea, a region heavily impacted by extensive mining activities and the growth of the population and settlements, which have led to the accumulation of heavy metals and trace elements in the soil. Methods: In the analysis of soil samples collected from the river basin, the determination of heavy metal and trace element content was performed using an inductively coupled plasma mass spectrometer, specifically the PlasmaQuant MS Elite S-NR:11-6000ST043 instrument. The spatial distribution of these elements within the river basin was mapped using ArcGIS 10.8 software.To create a comprehensive representation of the distribution, mathematical interpolation of the values was carried out using the Interpolation tool (Spatial Analyst Tools) within ArcGIS 10.8. The inverse distance weighted (IDW) technique was employed for this purpose. To assess the extent and severity of soil contamination by heavy metals and trace elements in the study area, three key parameters were calculated: the hazard coefficient Ko, the concentration coefficient (Kc), and the total pollution index. These values provide a quantitative measure of the contamination levels and associated risks in the region. Results and discussion: The analysis indicates that the concentrations of certain elements, such as silver (Ag), arsenic (As), beryllium (Be), cadmium (Cd), and selenium (Se), significantly exceed regulatory limits, posing a serious threat to the health of the population and the ecosystem of the river basin as a whole. The research categorized elements into four groups based on their hazard levels, ranging from those within acceptable concentration limits to those significantly exceeding them. Cadmium (Cd) is highlighted for its concentrations, which in some instances are 14 times above the standard limits. It also emphasizes the importance of further studies to identify the origins and assess the effects of selenium (Se), silver (Ag), and cadmium (Cd) on the river basin's ecosystem. The conclusion emphasizes the importance of developing strategies to reduce the harmful effects of pollutants, including the implementation of a system for regulating concentrations and measures for land reclamation. Implications of the research: a map of the total pollution index of the Fatala river basin was constructed. It was revealed that most of the territory belongs to the moderately dangerous pollution category, which is characterized by an increase in the overall morbidity rate. Originality/value: The authors stress the importance of conducting additional research, implementing a system for normalizing pollutant concentrations, and developing measures to reduce the detrimental impact of pollution on the environment and public health. This study serves as a valuable contribution to understanding the environmental implications of heavy metal and trace element pollution in the Fatala River basin and highlights the need for ongoing efforts to address this issue.

In this work, a study of the biogenic composition of atmospheric precipitation and its change during the passage through the crowns of trees of a downy oak forest was carried out. First of all, the content of rainwater-soluble compounds of all the considered elements in rainwater under the forest canopy was higher than in rainwater in an open area. It was revealed that the main forms of nitrogen in the atmospheric fallout were nitrates and ammonium. The average concentrations of nitrogen anions in rainwater collected under the canopy were higher than in rainwater collected in the open area. The proportion of nitrite nitrogen in rainwater under the canopy was 6% higher than in rainwater collected in the open area. Simultaneously with the increase in the proportion of nitrite nitrogen, nitrate nitrogen decreased. For all considered biogenic substances, an increase in their content was observed in the warm period of the year. We found an inverse relationship between the concentration of inorganic nitrogen and phosphorus in precipitation and the relative air humidity and wind speed. It was established that the pH of precipitation falling under the crowns of trees was lower than the pH of precipitation in the open area. It was revealed that the increase in the concentration of biogenic elements was in accordance with the phase of plant development during the growing season.

Tropical ecosystems play an important role in the environment. Coastal areas are subjected to a wide range of impacts and pollution, which have drawn worldwide attention over the past few decades. Comprehensive studies of heavy metal content in soils worldwide are extremely important for assessing and predicting ecological risks. Very few studies have been devoted to a complete study of the physicochemical characteristics of soils, assessment of heavy metal accumulation in coastal zones along the Djibouti coast, and potential ecological risks. The study investigated the physico-chemical characteristics of soil, assessed the accumulation of heavy metals in coastal zones along the Djibouti coast, and analyzed the potential environmental risks associated with the presence of heavy metals in the studied soils. Analysis of heavy metals and trace elements in the soils of the coastal areas of Djibouti revealed that the levels of these elements are lower than in soils of the Red Sea coast and are in line with WHO and other international standards. All heavy metals in the soil of the studied area demonstrate low levels of potential ecological risk. The soils of the studied areas, overall, have not undergone significant heavy metal pollution and can be considered suitable for various types of use.

The study of tropical landscape dynamics is of critical importance, particularly within protected areas, for evaluating ecosystem functioning and the effectiveness of natural conservation efforts. This study aims to identify landscape dynamics within the Dong Nai Biosphere Reserve (including Cat Tien National Park and the Ma Da Forest) using remote sensing (Landsat and others) and geographic information system methods. The analysis is based on changes in the Enhanced Vegetation Index (EVI), land cover transformations, landscape metrics (Class area, Percentage of Landscape and others), and natural landscape fragmentation, as well as a spatio-temporal assessment of anthropogenic impacts on the area. The results revealed structural changes in the landscapes of the Dong Nai Biosphere Reserve between 2000 and 2024. According to Sen’s slope estimates, a generally EVI growth was observed in both the core and buffer zones of the reserve. This trend was evident in forested areas as well as in regions of the buffer zone that were previously occupied by highly productive agricultural land. An analysis of Environmental Systems Research Institute (ESRI) Land Cover and Land Cover Climate Change Initiative (CCI) data confirms the relative stability of land cover in the core zone, while anthropogenic pressure has increased due to the expansion of agricultural lands, mosaic landscapes, and urban development. The calculation of landscape metrics revealed the growing isolation of natural forests and the dominance of artificial plantations, forming transitional zones between natural and anthropogenically modified landscapes. The human disturbance index, calculated for the years 2000 and 2024, shows only a slight change in the average value across the territory. However, the coefficient of variation increased significantly by 2024, indicating a localized rise in anthropogenic pressure within the buffer zone, while a reduction was observed in the core zone. The practical significance of the results obtained lies in the possibility of their use for the management of the Dongnai biosphere Reserve based on a differentiated approach: for the core and the buffer zone. There should be a ban on agriculture and development in the core zone, and restrictions on urbanized areas in the buffer zone.