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.

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.

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.

This study investigates the anthropogenic transformation of small- and medium-sized river basins within the Caspian Sea catchment. The basins of seven rivers—Sunzha, Sulak, Ulluchay, Karachay, Atachay, Haraz, and Gorgan—were selected as key study areas. For both the broader Caspian region, particularly its southwestern sector, and the selected study sites, trends in land cover types were analyzed, natural resource use practices were assessed, and population density dynamics were examined. Furthermore, a range of indices were calculated to quantify the degree of anthropogenic transformation, including the coefficient of anthropogenic transformation, the land degradation index, the urbanity index, the degree of anthropogenic transformation, coefficients of absolute and relative tension of the ecological and economic balance, and the natural protection coefficient. The study was conducted using geoinformation research methods and sets of geodata databases—the global LandScan population density database, the GHS Population Grid database, the ESRI land cover type dynamics database, and OpenStreetMap (OSM) data. The analysis was performed using the geoinformation programs QGIS and ArcGIS, and a large amount of literary and statistical data was additionally analyzed. It is shown that within the studied region, there has been a decrease in the number and density of the population, as a result of which the territories of river basins are experiencing an increasing anthropogenic impact, the woody type of land cover is decreasing, and the agricultural type is increasing. The most anthropogenically transformed river basins are Karachay, Haraz, and Gorgan.

The concentrations of 18 chemical elements were determined in the upper soil horizons within the landscapes of river basins in the Eastern Caucasus, using the Ulluchay, Sulak, Sunzha, Samur, Shuraozen (Russia), Karachay, and Atachay (Azerbaijan) rivers as case studies. This research aims to provide an ecological and geochemical assessment of soil conditions in the mountain river basins of the Eastern Caucasus. The ecological status of the soils is largely governed by elevated concentrations of such elements as Zn, Ni, Cu, Mo, As, and Cr, which exhibit both accumulation tendencies and potential toxicity. Environmentally unfavorable areas were identified through an integrated scoring assessment that incorporates the values of four ecological and geochemical indices: the modified contamination factor (mCf), the Pollution Load Index (PLI), the Potential Ecological Risk Index (PERI), and the total contamination index (Zc). According to each index, more than half of the study area is classified as uncontaminated. Low PLI values were recorded for 54% of the sampling sites, and low mCf values for 63%. Based on PERI and Zc, 82% of the sampling sites are categorized as uncontaminated. The integral scoring assessment enabled the delineation of more than a dozen environmentally unfavorable areas, with the highest concentrations observed in the Atachay and Karachay basins, spatially extensive in the Sunzha basin. The formation of environmentally unfavorable zones in terms of soil contamination is primarily driven by natural factors, including lithological conditions, climatic features, complex topography, and the directions of waterborne and mechanical migration. Anthropogenic factors contribute to a lesser extent to the development of high-contamination zones and exert only localized influences near major settlements. The results can be applied to mitigate public health risks and to promote sustainable development of mountain river basins. Targeted measures are proposed for the sustainable management of contaminated areas, including restrictions on agricultural activities and the use of drinking water sources.