Soil salinization has become a worldwide issue affecting agricultural development. Statistical methods and spatial analysis were used to analyze the degree and type of saline soils and their spatial distribution. The driving factors of soil salinity were explored using Geodetetcor models. In this study, 84 soil samples were collected from a 0–20 cm soil layer, and the total salt concentration and salt ion composition were measured. The results of statistical analysis and cluster analysis showed that SO₄²⁻ and Ca²⁺ had the highest concentrations of salt ions in terms of anion and cation contents, respectively. The interpolation results indicated that the study area was dominated by mild saline soils, with sulfate-type saline soils and chloride-sulfate-type soils dominating. Results of the factor detector suggested that the distance to the irrigation system (0.425), and distance to the drainage system (0.42), explained salinity more strongly in the Shardara district, and elevation (0.326) was the most important influencing factor for salinity in the Mahtaaral district. Results of the interaction detector indicate that human factors (distance to irrigation canals ∩ distance to drainage canals) had a stronger explanation both in the Shardara and Mahtaaral districts. This research provides a scientific basis for soil salinity regulation and management, which is crucial for sustainable agricultural development.

The dramatic shrinkage of the Aral Sea in the past decades has inevitably led to an environmental calamity. Existing knowledge on the variations and potential transport of atmospheric aerosols from the Aral Sea Basin (ASB) is limited. To bridge this knowledge gap, this study tried to identify the variations and long-range transport of atmospheric aerosols from the ASB in recent years. The Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model and Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) data were used to gain new insight into the types, variation and long-range transport of atmospheric aerosols from the ASB. The results showed five types of tropospheric aerosols and one type of stratospheric aerosol were observed over the ASB. Polluted dust and dust were the dominant subtypes through the year. Sulfate/other was the only stratospheric aerosol detected. The occurrence frequency of aerosols over the ASB showed obvious seasonal variation. Maximum occurrence frequency of dust appeared in spring (MAM) and that of polluted dust peaked in summer (JJA). The monthly occurrence frequency of dust and polluted dust exhibited unimodal distribution. Polluted dust and dust were distributed over wide ranges from 1 km to 5 km vertically. The multi-year average thickness of polluted dust and dust layers was around 1.3 km. Their potential long-range transport in different directions mainly impacts Uzbekistan, Turkmenistan, Kazakhstan and eastern Iran, and may reach as far as the Caucasus region, part of China, Mongolia and Russia. Combining aerosol lidar, atmospheric climate models and geochemical methods is strongly suggested to gain clarity on the variations and long-range transport of atmospheric aerosols from the Aral Sea Basin.

In the Syr Darya River watershed, 225 samples from three different layers in 75 soil profiles were collected from irrigated areas in three different spatial regions (I: n = 29; II: n = 17; III: n = 29), and the spatial and vertical variation characteristics of potentially toxic elements (Cd, Co, Cu, Ni, and Zn) and a metallic element (Mn) were studied. The human health risks and enrichment factors were also evaluated in the Syr Darya River watershed of the Aral Sea Basin in Kazakhstan. There were significant differences in the contents of heavy metals in the different soil layers in the different sampling regions. Based on element variation similarity revealed by hierarchical cluster analysis, the elemental groupings were consistent in the different layers only in region I. For regions II and III, the clustered elemental groups were the same between surface layer A and B, but differed from those in the deep layer C. In sampling region I, the heavy metals in surface soils were significantly correlated with the ones in deep layers, reflecting that they were mainly affected by the elemental composition of parent materials. In region II, the significant correlations only existed for Cu, Mn, and Zn between the surface and deep layers. The similar phenomenon with significant correlation was also observed for heavy metals in sampling region III, except for Cd. Finally, enrichment factor was used to study the mobilization and enrichment of potentially toxic elements. The enrichment factors of Zn, Cu, and Cd in surface layer A that were greater than 1.5 accounted for 1.16%, 6.79%, and 24.36% of sampling region I, respectively. In sampling region II, the enrichment factors of Zn, Cu, Cd, and Co that were greater than 1.5 accounted for 0.03%, 4.76%, 0.54%, and 9.03% of the total area, respectively. In sampling region III, only the enrichment factors of Zn, Cu, and Cd that exceeded 1.5 accounted for 0.24%, 4.90%, and 6.89% of the total area, respectively. Although the contents of the heavy metals were not harmful to human health, the effects of human activities on the heavy metals in the irrigated soils revealed by enrichment factors have been shown in this study area.

Over the past century, the impacts of human activities on the natural environment have continued to increase. Historic evolution of the environment under anthropogenic influences is an important reference for sustainable social development. Based on the geochemical analyses of a short sediment core of 49 cm from Lake Balkhash, the largest lake in Central Asia, potential factors historically influencing geochemical variation were revealed, and influences of human activity on regional environmental change were reconstructed over the past 150 years. The results showed that the dominant factor inducing changes in potentially toxic elements (V, Cr, Co, Ni, Zn, Cu, Cd, and Pb) is the physical weathering of the terrestrial materials. The variation in Ca content was influenced by the formation of authigenic carbonate. Since 1930, potentially toxic elements (Cr, Co, Ni, Zn, Cu, Cd, and Pb) in the lake sediments have obviously been affected by human activities, but the impact of human activities has not exceeded that of natural terrestrial weathering. In particular, the enrichment factors (EFs) for Cd and Pb reached 1.5. The average ecological risks of Cd were higher than the criterion of 30, suggesting a moderate risk to the local ecosystem in recent years. Total risk indices indicated moderate potential ecological risk for the lake ecology. The results will provide support for the environmental protection and better management practices of the Lake Balkhash watershed.

The burial of organic carbon in lake sediments plays an important role in the terrestrial carbon cycle. Clarifying the current status of carbon burial in the lakes of Central Asia is of great significance for the application of carbon balance assessments. With the analysis of the total organic carbon and nitrogen and the carbon isotope and organic carbon burial rate in the core sediment of the North Aral Sea, the status and influencing factors of organic carbon burial over the past 70 years can be revealed. The results showed that the main source of organic carbon was predominantly from lacustrine aquatic plants. However, the contribution of terrigenous organic carbon increased from the 1950s to the 1960s. The burial rate of organic carbon in North Aral Sea sediments was consistent with the overall change in the regional temperature. The burial rate of organic carbon showed an upward trend as a whole with an average of 28.78 g·m⁻²·a⁻¹. Since 2010, the burial rate of organic carbon has stood at the highest level in nearly 70 years, with an average of 55.66 g·m⁻²·a⁻¹. The protection of a lake by human beings can not only significantly improve the lake’s aquatic ecosystem but also help to increase the burial rate of the lake’s organic carbon.

With the desiccation of the Aral Sea, salt–alkali dust storms have increased in frequency and the surrounding environment has deteriorated. In order to increase our understanding of the characteristics and potential impact zone of atmospheric aerosols in the Aral Sea region, we evaluated seasonal and diurnal variation of aerosols and identified the zone most frequently impacted by aerosols from the Aral Sea region using CALIPSO data and the HYSPLIT model. The results showed that polluted dust and dust were the two most commonly observed aerosol subtypes in the Aral Sea region with the two accounting for over 75% of observed aerosols. Occurrence frequencies of polluted dust, clean continental, polluted continental/smoke, and elevated smoke showed obvious seasonal and diurnal variations, while occurrence frequency of dust only showed obvious seasonal variation. Vertically, the occurrence frequencies of all aerosol subtypes except dust showed significant diurnal variation at all levels. The thickness of polluted dust layers and dust layers exhibited same seasonal and diurnal variations with a value of more than 1.0 km year-round, and the layer thickness of clean continental and polluted continental/smoke shared the same seasonal and diurnal variation features. The zone most severely impacted by aerosols from the Aral Sea region, covering an area of approximately 2 million km², was mainly distributed in the vicinity of the Aral Sea region, including western Kazakhstan, and most of Uzbekistan and Turkmenistan. The results provide direct support for positioning monitoring of aeolian dust deposition and human health protection in the Aral Sea region.