Search

Climate change in Europe will lead to new precipitation patterns over the coming years and the annual temperature will increase significantly. These changes in climate variables and the resulting effects on agricultural productivity must be differentiated regionally. Plant production depends on sufficient rainfall in summer and, in some regions, on the amount of rainfall in winter. In Central Europe, the amount of precipitation in summer will decrease in the coming decades due to climate change, while in some regions, the amount of winter precipitation will increase significantly. Agricultural production is likely to suffer severely as a result of rising summer temperatures and low water retention capacities in the soil. The effects of reduced summer precipitation and increased air temperatures are partially offset by the expected increased CO2 concentration. Therefore, the effects that changed climatic conditions have on crop production are sometimes less drastic in terms of crop yields. The greatest impact of climate change on land use is expected from increasing evapotranspiration and lower amounts of precipitation in the production of leachate. In addition to the expected mean changes, the occurrence of extreme weather conditions is key. Periods of drought in the growing season and heavy flooding as a result of extreme rainfall are to be expected. However, these events are very difficult or even impossible to predict. In addition to the effects that climate change will have on regional crop production, global changes will have a strong impact on world markets for agricultural products. Another consequence of climate change and population growth is a higher demand for agricultural products on world markets. This will lead to dramatic local land use changes and an intensification of agriculture that will transform existing crop production systems. The intensification caused by rising land and lease prices will primarily affect the maximization of the use of fertilizers and pesticides.

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.

As an important part of the global carbon pool, lake carbon is of great significance in the global carbon cycle. Based on a study of the sedimentary proxies of Balkhash Lake, Central Asia’s largest lake, changes in the organic carbon sequestration in the lake sediments and their possible influence over the past 150 years were studied. The results suggested that the organic carbon in the sediments of Lake Balkhash comes mainly from aquatic plants. The organic carbon burial rate fluctuated from 8.16 to 30.04 g·m−2·a−1 and the minimum appeared at the top of the core. The organic carbon burial rate continues to decline as it has over the past 150 years. Global warming, higher hydrodynamic force, and low terrestrial input have not been conducive to the improvement of organic carbon sequestration in Balkhash Lake, the construction of a large reservoir had a greater impact on the sedimentary proxy of total organic carbon content, which could lead to a large deviation for environmental reconstruction. This is the first study to assess the sediment organic carbon sequestration using the modern sediments of Central Asia’s largest lake, which is of great scientific significance. The results contribute to an understanding of organic carbon sequestration in Central Asia and may provide a scientific basis for carbon balance assessment in regional and global scales.

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.

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.

Water is one of the most important natural resources. The water availability and scarcity depend on various natural and anthropogenic factors. Based on generalization and analyses of the numerous cartographic materials, and long-term runoff data, the water-economic basins (WEBs) in Kazakhstan were classified in order to identify the basin affected by human activities the most, to show the dynamics of river runoff within Kazakhstan, as well as to estimate the demand for water resources in the WEBs. Additionally, the water availability in the WEBs was determined by share (%) of water resources (rivers, lakes, water reservoirs). The Zhaiyk-Caspian WEB has the highest share (94%) of river water. By water resource (43.8 km3), the Ertis WEB is the most water-rich basin. A significant anthropogenic transformation was observed in the Aral-Syrdarya and Esil WEBs. Both basins are characterized by a deteriorated water quality. Due to natural factors and human activities, the total runoff decreased by 39.4 km3/year (23 km3/year is transboundary and local runoff is 16.5 km3/year) since 1965. Water consumption has decreased to 57% due to reduction of irrigation areas and industrial activities. However, the water consumption has increased by 1.33 and 1.25 km3/year in communal services and other needs due to the population growth. The water demand in Zhaiyk-Caspian WEB is very high and estimated in crisis degree (fourth class). The Balkash-Alakol WEB is characterized by a critical degree of water demand and belongs to the third class of water demand.

Saline soils are widespread in the southern and central parts of Kazakhstan. In these arid areas, the annual precipitation is 100–150 mm, while the evaporation exceeds the precipitation. The soils in these areas are medium and highly saline. In the framework of this study, numerous cartographic materials pertaining to the saline soils of Kazakhstan and Central Asia have been reviewed and researched. Four soil–halo–geochemical salt accumulation provinces have been identified in Kazakhstan on the basis of generalization and analysis of the available materials. The provinces differ from each other by their genesis, composition, and salt transportation patterns. ArcMap software was used as the main tool for the analysis of the soil–halo–geochemical provinces and the production of a salt accumulation map of Kazakhstan. The research of the salt accumulation geochemistry in the soils, mineral rocks, and groundwaters, salt accumulation types, and patterns of soil migration in the biosphere are the basis for the assessment of regions with irrigation activities. Therefore, the research of the saline soils and salt accumulation processes is of high practical importance.

The surface water hydrochemistry of the Syr Darya River in Kazakhstan was investigated at 39 locations to analyze regional hydrochemical characteristics and evaluate the irrigation suitability of the studied regions. The cations in the surface water are mainly Na+, Ca2+, and Mg2+, while the anions are mainly SO42−. The main hydrochemical type is Ca-Mg-SO4-Cl. From the perspective of natural factors, the hydrochemical characteristics in the study area are derived from the dual effects of rock weathering and evaporation-concentration; however, the influence of anthropogenic factors include industrial and agricultural production near the river and the inflow of urban domestic sewage on the hydrochemical characteristic is also present. The irrigation suitability evaluation of the surface water based on SAR, Na% and KI showed that the majority of the water is suitable for irrigation, and from the TDS content analysis, 71.43% of the samples are in a critical state, indicating that the influence of TDS concentration on irrigation suitability cannot be ignored. The results have practical significance for maintaining the sustainable use of water resources in the Syr Darya River. Electronic supplementary material The online version of this article (10.1007/s10661-019-7713-8) contains supplementary material, which is available to authorized users.

Lakes of Kazakhstan are very numerous. There are 48,262 lakes in size of one hectare and above with a total surface area of 45,002 km2. This list is not included in Caspian and Aral Seas, ponds, reservoirs, and plexus lakes. Small lakes in size 1 km2 with an area of 40,769 km2 (90%) (Fig. 3.1). There are 20 lakes larger than 100 km2 and are with an area of 26,886 km2 (Fig. 3.1), which is 59% of the water surface of all lakes. The total volume of water in these natural bodies is 190 km3 (Fig. 3.2).

According to the conditions of water exchange, there are differentiated drainage, periodically sewage, sewage, and flowing lakes in the territory of Kazakhstan. Main of them are drainless. The components of the water balance of the drainless lakes (surface runoff, precipitation falling on the surface of the lake, groundwater, filtration, and evaporation) are subject to large intra-annual and long-term changes. They are in conditions of shallow water lead to a characteristic for Kazakhstan in inconstancy level, the drying out of a significant part of the water bodies in summer and autumn seasons, as well as in perennial low-water periods.

The Issyk-Kul lake basin is located in a vast intermontane basin. Its width in the meridian direction near the Tosor village is 75 km. From here to the east and west, the basin narrows. Its total length from Chaar-Zhon to Kyzyl-Ompol is 240 km.

There are about more than 700 lakes in arid areas of northwest of China, and they are mainly distributed in Xinjiang. There are 29 lakes with size more than 10 km2, of which three lakes are distributed in both inside and outside the boundary of Inner Mongolia, and rest 26 lakes all located in Xinjiang.

The territory of Kazakhstan is 2717.3 thousand km2 and ninth biggest country in the world. It extends from west to east by 2995 km and from north to south by 1600 km. Kazakhstan borders with Russia in the north and west; in the south with Turkmenistan, Uzbekistan, and Kyrgyz Republics; and with the People’s Republic of China in the southeast (Dzhanalieva et al. in Physical geography of Kazakhstan. Kazak Universiteti, Almaty, p 266, 1998).

There are 1300 natural lakes in Tajikistan, with a total water surface area of 705 km2 and a total volume of about 50 km3.

The Central Kazakhstan includes the Karagandy region. There are 1910 lakes in Karagandy region with a total area of ​​926 km2 (Fig. 4.1), including 1779 lakes with size less than 1 km2 and takes about 14% of the total area. The hilly relief with a rare low water river network and climate aridity contribute a large number of low-capacity lakes and most of the drainless lakes.

The basis of the hydrographic system in Kyrgyzstan is the river systems and water catchments that are separated by watershed mountain ranges from each other (Fig. 8.1). The hydrographic system of river basins is made up of lakes, glaciers, groundwaters, swamps, and wetlands. All of them are products of orography, relief/topography, underlying surface, and climate. They have an interaction and mutual influence and take a direct part in the formation of the water balance of the river flow regime.

There are two river basins in Uzbekistan that form the Aral Sea Basin: The Amudarya and Syrdarya river basins. The Amudarya river basin covers 81.5% of the country’s territory. There are three sections of the river: (1) the upper course flowing along the border with Afghanistan and Tajikistan, where most of the water flow is formed; (2) the middle course, which first passes along the border of Uzbekistan and Afghanistan and then enters Turkmenistan, (3) as well as the lower course passing through the territory from Uzbekistan to the confluence of the Aral Sea.

There are 48,262 lakes in Kazakhstan, except the Caspian and Aral Seas, ponds, water reservoirs, and pliable lakes. The size of these lakes from 1 ha and more with a total surface area of 45,002 km2.

Central Asia covers the territory of five countries such as Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan. It is located in the center of the Eurasian continent with an area of 3,882,000 km2 and with a population of about 55 million people. It borders on Afghanistan and Iran in the south, China in the east, and Russia in the west and north (Grinyayev and Fomin in Actual issues of application of the mechanism of exchange trade for solving water and energy problems of the Central Asia countries. Moscow, 52 p, 2009).

This paper presented the results from the study of irrigation erosion of irrigated lands in southern Kazakhstan. The main purpose of the work is the conservation of the fertility of irrigated soils, and then the soils of the upper, middle and lower sections of the slopes at the experimental site were studied. Based on field investigations, authors studied the water resistance of aggregates of gray-brown soils and light gray soils before and after irrigation and qualitative indicators of changes in physical and chemical properties of structured soils in irrigation were determined by conventional methods of soil research. The results indicated that the changes in the physical properties of soils by using polymeric compounds created a fundamentally new opportunity to control water erosion of soils.