Архив метки: salinization

INFLUENCE OF CLIMATE CHANGE ON SOIL DEGRADATION IN ARID ZONES OF THE VOLGA REGION

Arid Ecosystems

UDC 631.434.52:504.123(470.4)

Gubarev D.I., Levitskaya N.G., Derevyagin S.S. INFLUENCE OF CLIMATE CHANGE ON SOIL DEGRADATION IN ARID ZONES OF THE VOLGA REGION // Arid ecosystems. 2022. V.28. № 1 (90). P. 20-27. | PDF

The aim of the research was to establish the impact of climate change on the processes of soil degradation and desertification in the arid zones of the Volga region. The material for the research was the observational data for 1971-2020 on 20 meteorological stations, as well as the results of soil-ecological and hydrogeological monitoring at research stations of the Federal State Budgetary Scientific Organization «Federal Center of Agriculture Research of the South- East Region» in the prevailing soil and climatic zones on the territory of the Saratov region (forest-steppe, steppe, dry steppe and semi-desert). Identified signs accompanying aridization, desertification and land degradation differentiated by natural zones. In particular, the average annual air temperature increased, compared with the climatic norm, by 1.0-1.2°С, the greatest increase was observed in August (by 2.0-2.2°С). The average temperature of the soil surface during the warm period increased by 1.1-1.5°C. The risks of severe atmospheric droughts during the entire growing season increased throughout the entire territory, most noticeably in the semi-desert zone (from 55 to 82%). The amount of precipitation in the spring increased by 10-25%, and in the summer – decreased by 23-30%. The boundaries of the semi-desert zone have shifted to the north and northwest. The tendency of changes in the hydrological regime of zonal soils from non-leaching to periodically leaching in 20-40% of years is outlined. The values of the aridity indices of the territory, calculated for the period from 2001 to 2020, increased in comparison with the climatic norm for 1971-2000 by 3-6%. This is an indicator of an increase in climate aridity during its current warming. As a result, high rates of dehumification (decrease in the relative humus content by 21-35%) and changes in the structural state of the arable layer and grain size distribution (decrease in water-resistant aggregates >0.25 mm from 39 to 31.8% and the absolute content of physical clay by 7.5%). At the same time, there is an increase in the mineralization of groundwater from 2500 to 7000 mg/l, as well as an increase in the content of toxic salts in the soil solution. Thus, the content of Cl—, SO42— ions in the places of replenishment with groundwater increased from 0.27 to 0.56 mg/eq. and from 0.27 to 13.27 mg/eq. respectively. The cation values also increased: Ca2+ – from 0.30 to 4.41 mg/eq., Mg2+ – from 0.12 to 5.59 mg/eq., The sum of K+ and Na+ – from 0.09 to 0.28 mg/eq. In the lowered elements of the relief, the development of processes of local salinization and waterlogging is noted.

Keywords.Climate change, aridization, drought, degradation, salinization.

Financing. The article was made within the state assignment No. 0751-2019-0008 “To develop theoretical foundations for structuring agricultural landscapes, adapting them to climatic and geomorphometric features of the territory in order to preserve and optimize the use of land resources to obtain an economically reasonable level of quality agricultural products”.

DOI: 10.24412/1993-3916-2022-1-20-27

SOILS OF ARID REGIONS OF SOUTHERN RUSSIA IN THE BASIC CLASSIFICATION OF SOILS OF THE WORLD

Arid Ecosystems

UDC 631.48

Zalibekov Z.G., Mamaev S.A., Biarslanov A.B., Kurbanismailova A.S. SOILS OF ARID REGIONS OF SOUTHERN RUSSIA IN THE BASIC CLASSIFICATION OF SOILS OF THE WORLD // Arid ecosystems. 2022. V.28. № 1 (90). P. 42-52. | PDF

Received April 24, 2020. After revision October 14, 2020. Accepted August 16, 2021.

Soil cartographic studies and preparation of soil maps are carried out using classification and diagnostics of soils, as well as various methodological approaches. The most acceptable in modern conditions are «Classification and diagnostics of soils of Russia» (2004), the main difference of which is the use of the principles of substantive genetic classification developed by V.M. Friedland. To further develop this classification, an attempt has been made to determine the classification position and properties of arid soils subjected to desertification, aridization. An important criterion determining the acceptability of the new approach is the allocation of supertype subdivisions (trunks – synlithogenic, postlithogenic organomineral soils) characteristic of highly degraded soils in the foci of desertification. Desertification, as a natural-anthropogenic process, leads to the loss of humus horizons and the emergence of a soil-forming geological rock on the surface. At the same time, the properties of soils at the highest supertype level change with the transition of postlitogenic to synlitogenic organomineral soils.

Taking into account the global nature of the manifestation of desertification, the control of changes is a prerequisite for determining the place of arid soils of the southern regions of Russia in the basic classification of soils of the world. The proposed article provides a theoretical justification for the classification differences allocated to supplement with diagnostics, a nomenclature of properties with an appropriate sequence.

Keywords: basic classification, substantive genetic classification, arid soils, synlithogenic variety, postlithogenic variety, halomorphic desertification, ferrallite formations, erosion, salinization, dehumification.

Financing. The work was carried out within the framework of the State Assignment of the Institute of Geology of the Dagestan Federal Research Center of the Russian Academy of Sciences “Landscape-geochemical zoning of the Caspian lowland”, Section 1, No. AAA-A117-117021310199-9 “Development of methodological foundations for studying the humus state and soil salinization for the purpose of landscape-geochemical zoning of arid territories”, Topic 3, No. AAAAA-A17-117021310203-3 “Ecological and geochemical features of groundwater of the North-Eastern Caucasus (Dagestan). Natural and anthropogenic pollution factors”.

DOI: 10.24412/1993-3916-2022-1-42-52

A SERIA OF MEDIUM-SCALE NATURAL MAPS OF THE JIZZAKH STEPPE IN THE 70S OF THE XX CENTURY (BEFORE THE BEGINNING OF MELIORATIVE LANDUSE)

Arid Ecosystems

UDC 631.4

Pankova E.I., Golovanov D.L., Yamnova I.A. A SERIA OF MEDIUM-SCALE NATURAL MAPS OF THE JIZZAKH STEPPE IN THE 70S OF THE XX CENTURY (BEFORE THE BEGINNING OF MELIORATIVE LANDUSE) // Arid ecosystems. 2022. V.28. № 1 (90). P. 53-64. | PDF

The article considers the natural conditions of the Jizzakh steppe in the 70-80-ies of the XX century. During this period, we created a series of maps that reflected the natural diversity of the steppe before the beginning of its reclamation development. The series of cards includes: 1) map of lithological and geomorphological zoning, 2) soil map, 3) maps of salinity, 4) map of gypsum-bearing soils. All the listed maps were created on a topographic basis of M 1:100000 using aerial photography materials. On the territory of the Jizzakh steppe, 22 lithological-geomorphological regions were identified, united into 5 lithological-geomorphological regions. Within their limits, detailed soil-salt maps M 1:2000 were additionally compiled for key areas. A series of maps is a kind of geoinformation system that characterizes the state of the soil cover of the Jizzakh steppe before its development.

The article provides information about the soil features of the selected areas. It is shown that within the limits of lithological and geomorphological areas, the selected areas differed significantly before irrigation in the history of development, lithological structure, structure of soil cover, degree of salinity and gypsum content of soils, and, therefore, in their reclamation properties.

The analysis of the differences in the initial soil-reclamation state of the selected regions and districts will now allow for a more reliable assessment of the advantages and disadvantages of the reclamation measures carried out in different areas of the Jizzakh steppe, taking into account their natural features.

Keywords: salinization, gypsum content, geography, cartography, genesis and classification of arid soils.

Acknowledgement. We thank L.A. Gafurova, who, at our request, provided us with a list of recent works containing information about the current state of the soils of the Jizzakh steppe.

Financing. The work was carried out on the topic of the State Task of Research No. 0591-2019-0023 “To identify the features of soil salinization in different regions of Eastern Siberia and adjacent territories”.

DOI: 10.24412/1993-3916-2022-1-53-64

THE INFLUENCE OF ANTHROPOGENIC FACTORS ON THE CHEMICAL COMPOSITION OF LAKES IN ARID REGIONS OF DAGESTAN (ON THE EXAMPLE OF THE GREAT AND SMALL TURALI)

Arid Ecosystems

Yusupov A.R., Kurbanismailova A.S., Alkhulaev K.G., Mamaev A.S., Yusupov Z.A. THE INFLUENCE OF ANTHROPOGENIC FACTORS ON THE CHEMICAL COMPOSITION OF LAKES IN ARID REGIONS OF DAGESTAN (ON THE EXAMPLE OF THE GREAT AND SMALL TURALI) // Arid ecosystems. 2021. V.27. № 4 (88). P. 118-122. | PDF

Anthropogenic impact on the ecosystems of arid areas leads to environmental pollution. Assessment of the state of nature of arid regions is the most important task in the context of scientific and technological progress.

When studying the current state of the Turaly lakes, as representatives of reservoirs of arid conditions, various research methods were used. This made it possible to draw a conclusion about the level of pollution of objects and to assess the ecological condition of reservoirs characteristic of natural complexes of arid conditions.

Key words: arid climate, ecology, anthropogenic influence, pollution, salinization, Turaly lakes.

Financing. The work was carried out on the topics of the Research Institute of the Russian Academy of Sciences: «Assessment and revision of the mineragenic potential of the North Caucasus on the basis of modern stratigraphic and lithological-geochemical methods of analysis of sedimentary complexes»(State registration No. AAAA19-119122690018-8) and «Ecological and geochemical features of groundwater in the North-Eastern Caucasus (Dagestan). Natural and anthropogenic pollution factors» (State Registration No. AAAAA 117-117021310203-3.

DOI: 10.24412/1993-3916-2021-4-118-122