Arid ecosystems. 2022. V.28. № 2 (91)

UDK 556.535.3

HYDROECOLOGICAL CONSEQUENCES OF CLIMATE CHANGES IN THE WATER REGIME OF SPRING FLOOD IN THE UPPER REACHES BASIN OF THE ARPA RIVER

*Yerevan State University. Faculty of Geography and Geology

1, Alek Manoukian Str., Yerevan, 0025, Armenia. E-mail: vmargaryan@ysu.am

**Russian State Hydrometeorological University,

Institute of Hydrology and Oceanology, Department of Engineering Hydrology

79, Voronezhskaya st., Str. Petersburg, 192007, Russia

E-mail: oderiut@mail.ru, natalia.myakisheva@yandex.ru

***«Hydrometeorology and Monitoring Center» SNCO, Ministry of Environment

46, Charenc Str., Yerevan, Republic of Armenia

E-mail: levon_azizyan@yahoo.com

Received 21.10.2021. Revised16.12.2021. Accepted 13.01.2022.

The article discusses the long-term trends in river flow change of spring floods and hydroecological and water management consequences of climate change in the upper river Arpa. The study used data on average daily water discharge and water temperature in the river section Jermuk of the Arpa River, also data on the main meteorological elements at the Jermuk meteorological station located in the upper reaches basin of the Arpa river.

It is presented that one of the most important characteristics of the flood is maximum water discharge during the spring flood. Absolute maximum discharges vary by range from 8.26 to 199 m³/s, average maximum flow rates — from 1.86 to 116 m³/s.

Discussed and evaluated the interannual change in the dates of the beginning, end, duration and volume of spring flood runoff, also temperatures surface layer of air and atmospheric precipitation for December-February and for April-June, maximum water reserve as snow, water temperature for April-June.

It is shown that over the past 28 years, the volume of floods and their duration diminished, the dates are shifted towards earlier dates, the maximum water discharge during the flood period decreases. It was revealed as well that winter and spring-summer (for April-June) average air temperatures increase, winter precipitation increases, the maximum supply of water in the snow decreases. As a consequence of modern changes in the hydrological regime of spring floods numerous hydroecological and water management problems are

It is noted that interannual fluctuations show the clearly visible fracture in the course of average monthly volumes of spring floods at the beginning-middle of 1990-ies after which the period of significant and stable lowering of discharges began. Typically maximum values water (as well as air) temperatures are observed in July – August, and minimum — in December – January (air temperature) and in January (water temperature). Average monthly water temperatures in winter season (December – March) at the Jermuk section of the Arpa river are positive, negative temperatures are observed rarely, in single winters with severe frosts. Negative air temperature values are recorded mainly from the second half of November and last until the end of March. The average water temperature on the river Arpa — Jermuk settlement for the period April-June is 4.9°C, average annual temperature of air and soil surface at the Jermuk meteorological station – 8.6°C and 11.7°C, respectively.

It is presented that one of the most important characteristics of the flood is maximum water discharge during the spring flood. The value and date of the onset of the maximum water discharge correlate with the amount of snow reserves, the intensity of the inflow of warm air and precipitation. Absolute maximum costs vary by range from 8.26 to 199 m³/s, average maximum flow rates – from 1.86 to 116 m³/s.

It is noted that present climatic changes lead to significant degradation of high water as phases of the water regime in the upper part of the Arpa River basin: increase in winter season surface air temperature is the main reason for the decrease of water content of spring in the upper reaches of the river Arpa.

Correlations between the values of the volumes of the spring floods in the upper reaches of the river Arpa, calculated from April to June and from the beginning floods before its end are presented in the paper. This dependency can be used to estimating, calculating, and also checking the volume of spring floods, if we have the data of the volume runoff for April – June.

Keywords: Arpa river, Key words: spring flood, air and water temperatures, precipitation, maximum water reserve in snow, interannual variation, hydroecological and water management problems, the upper reaches of the Arpa River.

Financing. The study was carried out with the financial support of the Committee of Science of the Republic of Armenia and the Russian Foundation for Basic Research (RFBR) within the framework of the joint scientific program 20RF-039 «Short-term probabilistic forecast of river flow during the spring flood» and No. 20-55-05006\20.

DOI: 10.24412/1993-3916-2022-2-3-12

UDK 910.3; 911.2; 911.6

FACTORS OF TERRITORIAL DIFFERENTIATION OF THE AGRICULTURAL LANDSCAPES AND PROSPECTS FOR THE CONSERVATION OF THE STEPPES IN THE BELGOROD REGION

*Institute of Geography of the Russian Academy of Sciences

29, Staromonetny lane, Moscow, 119017, Russia

**Belgorod State University

85, Pobedy str., Belgorod, Belgorod region, 308015, Russia. E-mail: tishkov@igras.ru, a.s.nekrich@igras.ru

Received 30.09.2021. Revised 16.12.2021. Accepted 13.01.2022.

Reduction of the carbon footprint at the district level derived from agricultural production can be achieved by the rational planning of territories including agricultural landscapes along with the optimal spatial distribution of areas reducing agrogenic carbon emissions. The matter of transition to «carbon-neutral agriculture» and the optimization of agricultural landscapes structure are of primary importance for regions such as the Belgorod oblast, providing 4.8% of the total value of Russian agricultural products and where virgin areas of the steppes allowing effectively regulate the carbon balance are located.

Basing on statistical data, on cartographic and literary materials, on reports are published by specialized departments and ministries, as well as on materials of long-term field and experimental studies conducted by the authors in the Belgorod region at the intra-district level during 1990 to 2020, tendencies of the agricultural land dynamics within the structure of modern agricultural landscapes were explored and compared to dynamics of areas of virgin steppe lands and areas of the nature reserve fund lands.

It has been found that agricultural and resource areas uniting municipal areas characterizing by similar trends of agricultural land dynamics in the structure of agricultural landscapes, by similar specialization of agriculture, by identical changes of the natural, social, economic and environmental situation are occur: (1) agricultural and resource area of industrial concentration near large cities in the western and central parts of the region; (2) agricultural and resource area of the conflicts between agriculture and mining in the northern part of the region; (3) agricultural and resource area of the southeastern agricultural and industrial part of the region. Within the boundaries of these agricultural and resource areas, key factors that determine the potential for agricultural production and trends in the dynamics of agricultural landscape areas have been identified. The size of specially protected natural areas (SPNA) allowing reduce agrogenic carbon emissions within these agricultural and resource areas has been estimated. The importance of such territories for supporting of «carbon neutrality» during the modern economic development is outlined. It has been determined that from west to northeast and southeast within the agricultural and resource areas the large-scale decrease of agricultural landscapes is not viewing, however their agricultural potential is declining. This feature can be explained by acceleration of negative natural and ecological factors, weak implementation of adaptive land use practice in process of agricultural production, disproportion investments to industrial agriculture and also reduction of rural population. It is shown that the scale of conflicts in agricultural and industrial environmental management is increasing in the east and north-east directions.

In order to determine the links arising between key factors (affecting the use of landscapes for agrarian purposes) and the change of agricultural lands within the agricultural and resource areas methods of mathematical statistics were applied. The prospects of territorial protection of virgin steppes areas in the perspective of solving the problems of «carbon neutral agriculture» in the conditions observable dynamics of agricultural lands are considered. The identified features of the transformation of the agricultural landscapes of the Belgorod region will allow in the future to optimize its structure in the context of achievement the goals of «carbon-neutral agriculture» and to increase the effectiveness of the Regional Protected Areas Network.

Key words: Belgorod region, agricultural landscape, territorial differentiation of land use, virgin and specially protected natural areas, «carbon neutrality».

Financing. The study was carried out within the framework of the state assignment of the Institute of Geography of the Russian Academy of Sciences AAAAA 19-119021990093-8 (FMGE-2019-0007).

DOI: 10.24412/1993-3916-2022-2-13-26

UDC 630*261; 630*91

INTEGRATED APPROACH FOR ASSESSMENT

AND MONITORING OF FORESTS CONDITIONS IN THE DRYLANDS OF SUDAN

A.A.H. Siddig*^,****^,*****, Hai Jiang Bo*****

*University of Khartoum, Department of Forest Conservation and Protection, Faculty of Forestry

P.O. Box 321, Al-Gama’a Avenue, Khartoum, 11111, Sudan. E-mail: naouofk@gmail.com

**Institute of Desertification Studies and Desert Cultivation, University of Khartoum

P.O. Box 321, Al-Gama’a Avenue, Khartoum, 11111, Sudan.

***Ministry of Agriculture and Natural Resources

Sudan, North Kordofan State, Elobied City

****University of Massachusetts Amherst, Department of Environmental Conservation

MA 01003-9285 Amherst, USA

*****Africa Relation Center, Northwest Agriculture & Forestry University

3, Taicheng Road, Yangling, Shaanxi, 712100, China

Received October 11, 2021. Revised November 27, 2021. Accepted December 01, 2021.

Forest resources in the drylands of Sudan are fluctuating in their tree cover and eco-functions. Reliable and timely information on their status is pivotal to address their socioeconomic and environmental benefits in the national environmental policy. Thus, this study aimed to develop an assessment and monitoring systems for their trees’ cover, threats, and disturbances along with forests dependents’ needs and activities in Wad Al-Bashir forest area with a view of establishing database for robust forests management plans and strategies. The study combines Ground-Based Survey (GBS), socioeconomic survey (structured questionnaire and key Informant interviews) and geo-special technique (satellite images for 1988, 2008 and 2018) as integrated methods for assessing and mapping the past and current forest conditions and disturbances. GBS results found and georeferenced sites of biotic and abiotic forest disturbances as well as man’s detrimental activities like trees logging which have had affected trees’ health and contributed to its degradation. The biotic threats were: invasive species (Acacia nubica), pest (Sinoxylon senegalensis) and climbers, while the effect of abiotic was mild like the wind effects. Social survey findings on the other hand, signposted the direct and indirect causes of deforestation and forest degradation. Direct causes were the conversion of forestland onto farmlands, illegal cutting and uncontrolled-grazing consecutively. Indirect causes were improper forest policy implementation, population growth, poverty and land tenure system. The geospatial technique showed considerable land use/land cover changes, where 2008 had considerable forest cover (72.2%) compared with 1988 (63.8%) and 2018 (58%), and accordingly, 2018, encompasses vast farmland area than 1988 and 2008 accounting for 38%, 25.9%, and 6.1% respectively. The study concluded that the effectiveness of using GBS, socioeconomic survey and geospatial technique as incorporated methods that could give a representation of all forests’ related aspects in one scene as well as better understanding for the genuine status.

Keywords: forest assessment and monitoring, drylands forests, ground-based and socioeconomic survey, forests threats and disturbances, Sudan.

Financing and Acknowledgements. Nasradeen Adam Hamed Gadallah is thankful to the Ministry of Higher Education and Scientific Research of Sudan for its financial support to his M.Sc. Project at University of Khartoum, Desertification Studies and Desert Cultivation Institute. Also, my appreciation goes to Sudan National Forest Corporation in Gedaref States for their viable help and assistance.

DOI: 10.24412/1993-3916-2022-2-27-39

UDC 911.2:502:571.51

CHANGE OF STOCKS OF MOBILE SUBSTANCE AND THERMAL REGIME OF NATURAL AND ANTHROPOGENIC CHANGED SOILS OF THE NAZAROVSKY FOREST-STEPPE

V.B. Sochava Institute of Geography of the Siberian Branch of the Russian Academy of Sciences

1, Ulanbatorskay Str., Irkutsk, 664033, Russia. E-mail: Irina-vorobyeva@yandex.ru

Received 13.05.2021. Revised 29.10.2021. Accepted 13.01.2022.

The article presents the results of studies on changes in the content and stocks of water-soluble forms of calcium, magnesium, organic and mineral carbon and moisture in natural and anthropogenically modified soils, as well as changes in the temperature of natural soils in different locations. The relevance of the study is due to the need to analyze the changes in the studied parameters under the conditions of short-term climate changes in the insular forest-steppe of the Nazarovsky depression. Generally accepted methods were used in the research: landscape-geochemical, comparative-analytical, comparative-geographical and statistical methods. It has been established that the moisture stocks in the meadow- swamp soil are maximum, in the meadow-leached chernozem soil they are minimal, and in the ordinary meadow chernozem and its anthropogenic modification – fallow – the values are close, which is connected with their position in the relief and the hydrothermal regime. It was revealed experimentally («in situ») that the temperature curve is steeper in ordinary meadow chernozem, freezing temperatures are lower, and the period with negative temperatures is longer than in meadow-swamp soil. New knowledge was obtained on changes in the reserves of water-soluble forms of calcium, magnesium, organic and mineral carbon, moisture content and fluctuations in climatic parameters (air temperature and precipitation amounts). Intra-annual changes in the temperature of natural soils («in situ») of the insular forest-steppe have been established for a more complete understanding of the dynamics of natural processes, as well as the use of the results obtained in further research on the study of the insular forest-steppe in a changing climate.

Keywords: natural, anthropogenic, soils, temperature, moisture, stocks, organic and mineral carbon.

Financing. The work was carried out within the State task of the IG SB RAS: (No. FM-2021-0002), the state registration number of the topic: AAAAA-A21-121012190055-7 «Spatial and temporal patterns of the material state of the landscapes of Siberia in changing environmental conditions».

DOI: 10.24412/1993-3916-2022-2-40-50

UDC 631.445.57

ISOTOPE SIGNATURE OF SOILS IN THE DIAGNOSTICS OF THE PROCESSES OF DAGHESTAN LANDSCAPES ARIDIZATION

M.V. Lomonosov Moscow State University, Faculty of Soil Science

12, MSU, 1, Leninskie gory, Moscow, 119991, Russia. E-mail: natalia_kovaleva@mail.ru

Recieved 20.10.2021. Revised 23.11.2021. Accepted 11.12.2021

The paper presents the results of humus isotopic composition and radiocarbon age of the buried soils determining in the mountain soils of Dagestan. General chemical properties and properties of soil organic matter of modern and buried soils of Inland Daghestan are investigated. It was found that the Preboreal and Atlantic optimums of Holocene in Eastern Caucasus were characterized by a droughty climate while the Medieval period climate can be characterized as a moderate one, similar to the climate of our time. Little ice age period was absent in Daghestan. It is shown that the anthropogenic use of mountain landscapes leads to their stepping down contrary to natural climatic trends

Key words: mountain soils, Holocene, palaeoenvironment, carbon isotopic composition.

Financing. The work was carried out with the financial support of the grant of the Russian Science Foundation No. 17-14-01120 2017-2021. «Soil biomarkers in the diagnosis of global climate change and prevention of regional environmental crises.»

DOI: 10.24412/1993-3916-2022-2-51-61

UDC 631.4

HEAVY METALS IN ECOSYSTEMS OF CRYOARID LANDSCAPES OF THE WESTERN TRANSBAIKALIA

Institute of General and Experimental Biology of the Siberian Branch of the Russian Academy of Sciences

6, Sakhyanovoy Str., Ulan-Ude, 670047, Russia

Received 30.07.2021. Revised 14.12.2021. Accepted 13.01.2022.

The results of experimental work on the study of the transformation flux of heavy metals: copper, zinc, nickel and lead from parent rocks into chestnut soils, then into virgin grass stand and humic substances are presented. The soil-forming rocks are deluvial and deluvial-proluvial deposits, as well as deposits of sands and pebbles, which, as a result of their weathering, movement and redeposition, determine the unequal granulometric, mineralogical and chemical composition of rocks, affecting the composition of the soil cover. Chestnut soils are characterized by an arid climate, a long stay in a frozen state, low bioproductivity, low power, light particle size distribution, and low humus content. For the extraction of humic substances, the Grimme method was used. The determination of the content of trace elements was carried out by the atomic absorption method with direct electrothermal atomization of samples. Heavy metals were determined on an atomic absorption spectrophotometer – AAS-15 Perkin Elmer. It was revealed that, due to the depletion of rocks in copper and nickel, there are few of them in the soils, and there is more zinc and lead, which, respectively, is reflected in the vegetation and humus.

Key words: heavy metals, humic substances, parent rocks, vegetation, chestnut soils, Western Transbaikalia.

Financing. The work was carried out on the topic of state task No. 121030100228-4 «Evolutionary-genetic, biogeochemical and productive functions of soils of the Baikal region as a component of the biosphere, assessment of their resource potential and development of technologies for rational use and protection» 2021-2022.

DOI: 10.24412/1993-3916-2022-2-62-70

УДК 574.2

Intra-body Variations of Stable Isotope Ratios (δ¹³С and δ¹⁵N)

of Mediterranean Soil Invertebrate Species

A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences

33, Leninsky Avenue, Moscow, 119071, Russia. E-mail: dkorobushkin@yandex.ru

Received 18.10.2021. Revised 23.11.2021. Accepted 11.01.2022.

In recent decades, the analyses of stable isotopes have been widely used to study trophic relationships in soil ecosystems. The isotopic signature of heterotrophic organisms reflects the isotopic composition of their food. To discover trophic position of soil invertebrates in detrital food webs, stable isotopes of carbon (δ¹³С) and nitrogen (δ¹⁵N) are mainly used. However, the correct use of this technique is often obstructed by the individual (within the organism) variability of the isotopic composition of carbon and nitrogen between tissues and organs of many soil invertebrate taxa. The aim of this study was to compare the individual variability of the isotopic composition of various tissues and organs of the mass Mediterranean species of woodlice (Isopoda, Armadillidae, Armadillo officinalis and Armadillidiidae, Armadillidium vulgare) and centipedes (Chilopoda, Scolopendromorpha, Scolopendra cingulata).

Soil invertebrates were collected within Utrish State Nature Reserve (Krasnodar krai). For isotopic analysis, the following tissues/organs were used: exoskeleton, muscles, Gastrointestinal wall, fatbody (only in scolopendra), reproductive system, legs, whole homogenized organism. The isotopic composition of δ¹³С and δ¹⁵N was estimated using a set of equipment consisting of an elemental analyzer and an isotope mass spectrometer.

Differences of carbon isotopic composition between woodlice tissues reached 5-6‰ due to the inclusion of inorganic carbonates in the exoskeleton. No significant difference in the isotopic composition was found between the tissues of the scolopendras. For a correct assessment of the trophic position of large woodlice species using isotope analysis, it is most preferable to use muscle tissue. The use of legs is possible only after a preliminary assessment of the carbonate content in the integumentary tissues of the species. It is necessary to exclude the homogenization of specimens of large isopods, as well as the inclusion of exoskeleton fragments and food debris into the analyzed sample. To estimate the isotopic position of scolopendra, muscles, homogenized samples of the whole animal, as well as individual parts of the body and organs, with the exception of the stomach contents, can be used. The results obtained are applicable to optimize soil-zoological studies using isotopic analysis of invertebrate tissues.

Keywords: soil macrofauna, isopodes, centipedes, stable isotopes, Utrish nature reserve, detrital food webs

Financing. The study of the isotopic composition of invertebrates was carried out with the financial support of the RGNF grant No. 19-74-104, year 2019-2022: «The role of marine organic matter subsidy in the formation of the functional and taxonomic structure of terrestrial detritus food webs».

Acknowledgements. The authors are grateful to O.N. Bykhalova for her help in organizing work on the territory of the Utrish Nature Reserve.

DOI: 10.24412/1993-3916-2022-2-71-77

UDC 631.46

DYNAMICS OF MICROBIOLOGICAL DIVERSITY OF SOILS IN THE CHU VALLEY WITH CHANGES IN THE TYPE OF PASTURE USE

*Kyrgyz-Turkish University «Manas»

56, Aitmatov Avenue, Bishkek, 7200042, Kyrgyz Republic. E-mail: nurzat.totubaeva@manas.edu.kg

**Institute of Chemistry and Phytotechnology, National Academy of Sciences of the Kyrgyz Republic,

265, Chui Avenue, Bishkek, 720000, Kyrgyz Republic. E-mail: alhor6464@mail.ru

Received 28.06.2021. Revised 09.01.2022. Accepted 13.01.2022.

Soil microflora is one of the first to feel the negative impact from the outside and can serve as a good biological indicator of changes in the soil structure and assess the degree of impact on the soil ecosystem. Studies were conducted on two demonstration plots, one of which was withdrawn from pasture use for two years and compared with the control variant, actively used. The studies showed that reduction of anthropogenic load, on the studied demonstration plots, significantly leads to activation of microbiological processes and a significant increase in microbiological diversity in the soil, which indicates improvement of enzymatic properties and acceleration of the process of soil self-repair. Researches have shown as well that soils being in a usual regime of unregulated overgrazing are considerably exposed to drying and trampling that leads to reduction of microbiological diversity in a soil ecosystem and domination of forms of microorganisms resistant to adverse environmental factors. The data obtained suggest that overgrazing affects the structure of soil microbiocenosis replacing it with more drought-resistant species. Micromycetes of the studied soils were represented in the dominance of Trichoderma, Cladosporium and Alternaria species resistant to unfavorable environmental factors, i.e. the species diversity was insignificant with the predominance of representatives of dominant species. Thus, the microbiological diversity of soils exposed to various degrees of anthropogenic pressure can serve as a biological indicator of the state of the soil ecosystem, it is also necessary to resolve the issue of regulation of rotational grazing, which can also ensure the preservation of pasture productivity and contribute to the conservation of biological diversity of flora and fauna of pastures respectively.

Keywords: microbiological diversity, anthropogenic load, soil monitoring, ecosystem, type of pasture use, pasture degradation

Financing. All activities within the framework of the project «Protection of wild tulips and support of pasture communities in the mountains of Kyrgyzstan» were carried out jointly with partner organizations: FC «Fauna and Flora International» in the Kyrgyz Republic, OF «Bioresources» and «Association of Forest Users and Land Users of Kyrgyzstan», with financial support from the Darwin Initiative program of the UK Government.

DOI: 10.24412/1993-3916-2022-2-78-84

UDC 631.6:556.5

REPUBLIC OF KYRGYZSTAN WATER POTENTIAL: PROBLEMS AND POTENTIALS FOR THE ECONOMIC DEVELOPMENT

Naamatov Naryn State University

25, Sagynbai Orozbak uulu Str., Naryn, 722900, Kyrgyz Republic. Е-mail: n_nuralieva@mail.ru

Received 30.11.2021. Revised 15.12.2021. Accepted 01.12.2021.

Irrigation remains an essential component of food security in many countries around the world. And Kyrgyzstan is one of these. At the same time, the water resources of Kyrgyzstan are still not used fully efficiently. This study demonstrates an assessment of the conditions of the Kyrgyz Republic water resources formation and their quality evaluation. The assessment is based on an analysis of a new draft State Program for the Development of Irrigation of the Kyrgyz Republic in 2017-2026 and on the evaluation of the irrigation facilities in the Republic. Moreover, the relevance, economic and technical indicators of these facilities were taken into account. Modern realities demonstrate natural resources have to be used carefully and rationally. High-quality and safe water is becoming one of the most demanded resources in many countries of the world. So, the «water powers» can make water their strategic resource. However, the operation and maintenance of water systems require considerable financial investments. Payment for water use can become the basis for reforming the economic mechanism of interstate relations. As the result of the study was formulated substantiated directions of the strategic modernization of the reclamation fund, the expansion of the scope of the reclamation measures carried out that are linked to the priority measures for the development of the water balance rational using.

Keywords: water resources, water distribution, irrigation, water losses, effective water conservation, agriculture; water policy, food security.

Financing. The research was carried out within the framework of the research program of the Department of Economics, Management and Tourism of S. Naamatov Naryn State University.

DOI: 10.24412/1993-3916-2022-2-85-93

UDC 556.311.31

FORECAST AND OPERATING RESOURCES OF GROUNDWATER

IN THE FOOTHERN DAGESTAN

A.S. Kurbanismailova, A.Sh. Huseynova

Institute of Geology of the Dagestan Federal Research Center of the Russian Academy of Sciences

75, M. Yaragsky Str., Makhachkala, 367030, Russia. E-mail: dangeogis@mail.ru

Received 28.10.2021. Revised 30.11.2021. Accepted 10.01.2022.

The determination of the predicted operational resources of ground fresh water (PERPV) in the territory of the third order hydrogeological structure – the system of small artesian basins (SMAB) – was carried out taking into account the water deficit in Foothill Dagestan in the conditions of an acutely arid climatic regime. In geological terms, the study area belongs to the Tertiary folding, where over the past decades, work has been carried out on the search, exploration and assessment of reserves and predicted resources for the use of fresh groundwater for domestic drinking water supply. A generalization of previous studies and the identification of promising hydrogeological regions with the calculation of predicted resources for the use of fresh groundwater, especially overdeep wide river valleys, turning into alluvial cones and forming foothill plumes, is carried out. Data on meteorological, hydrogeological and geological study of the territory, chemical composition of groundwater and lithology of cover and aquifers have been processed; identified promising areas for groundwater exploration, areas of their feeding, transit and unloading for the development of a design scheme. The analysis of the operation of the existing water intakes on the approved reserves was carried out and the possibility of increasing the PERPV outside the fields was considered. The hydrogeological conditions of the region, SMAB are given, a brief description of previously explored groundwater deposits is given, promising areas for exploration of groundwater are identified, where their predicted operational resources are calculated. For the limited synclinal structures of the Upper-Middle Sarmatian deposits, the PERPV was determined with the condition of the infiltration of atmospheric precipitation. Its value was 25.6 thousand m³/day. for synclinal artesian intermountain basins, for Chokrak, Chokrak-Tarkhan and Konk-Karagan sandy-clay deposits.

Key words: East Ciscaucasia basin, stratal and block-stratal confined waters, system of small artesian basins (SMAB), Foothill Dagestan, fresh groundwater resources, river deposition, hydrogeological conditions.

Financing. The work was carried out within the framework of the topics of the state assignment of the Institute of Geology of the Russian Academy of Sciences (State registration No. AAAAA 17-117021310203-3). Topic: «Ecological and geochemical features of groundwater in the North-Eastern Caucasus (Dagestan). Natural and anthropogenic pollution factors».

DOI: 10.24412/1993-3916-2022-2-94-101

UDC 631.4

Salinization of Soils in the Don Valley under Conditions

of Irrigation Cessation

*V.V. Dokuchaev Soil Science Institute

2, Building, 7, Pyzhevsky Per., Moscow, 119017, Russia. E-mail: g-irina14@yandex.ru

**Geoinformation Center of the Russian Academy of Sciences

168, b/o, 11, Novy Arbat Str., Moscow, 119019, Russia. E-mail: chursin.ivan93@gmail.com

Received 05.10.2021. Revised 01.11.2021. Accepted 01.12.2021

The presented study is aimed at identifying the current salinity state of the soils of the Generalovskiy Irrigation System (IS), built near the Tsimlyansk reservoir (1959) and located in the dry-steppe zone of the Volgograd oblast, in the Don Valley. The system is currently in the conditions of a 30-year period of cessation of irrigation. During the interpolation study, soil salinity maps were created, covering their different depths and based on field survey materials and water extraction data (1:5) of soil samples collected in 2020. Water extraction data obtained in the Volgograd Hydrogeological and Reclamation party (2018) were also used.

The key plot of the research was located on the 2nd left-bank terrace above the floodplain of the Don River and included the territory where by the beginning of the 1990s, during a long period of irrigation, a high level (1.5-3 m) and strong mineralization (3-10 g/l) of groundwater formed, which led to the forming of meadow solonchak and secondary salinized soils of a strong degree of salinity. This stimulated the salinization mapping of the territory and encouraged us to determine the changes happened during the past period.

The analysis of soil salinity maps made it possible to: assess the current salinity state of soils located on various elements of the topography of the second terrace of the Don River and comparison of the current salt state of soils with the period of the late 1980s and early 1990s, which showed the gradual salinization of previously saline areas and the development of alkalinization of the upper horizons of soils. Soil salinization is caused by the cessation of irrigation, and soil alkalinization is caused by the location of the Generalovskiy IS in the salt zone, a long period of irrigation (1960-1992) and irrigation from the Tsimlyansk reservoir with water with an increased concentration of sodium. Soil salinity maps showing the depth of the salt horizon provide information necessary for the development and selection of optimal reclamation measures to restore soil fertility.

Preliminary recommendations for solving this problem when irrigation is resumed may be: quality control of irrigation water, the use of periodic (every few years) spring water-supply washing of the 0-70 cm layer to push accumulated salts out of the aeration zone, plastering to ensure the displacement of exchangeable sodium, suppression of alkalinity and removal of water-soluble sodium into the underlying horizons beyond the root layer, the use of drip irrigation, an increase in the sharer of perennial legumes and cereals in the structure of planted acreage.

The impossibility of using spectral indices (given in the literature) to determine soil salinity with the help of satellite imagery in relation to the selected research area is shown in the article. A multiple regression analysis was carried out to confirm this. In this analysis, the values of spectral indices in four channels of the Sentinel-2 satellite image and the salinity values of different soil horizons at the sampling points obtained as a result of field and laboratory work were used as features. According to the results of regression analysis, there was no significant relationship between spectral indices and salinity values in all soil horizons. The obtained correlation coefficients were lower than 0.5 and, therefore, the relationship was very low.

Keywords: soil salinization, irrigation system, interpolation method, soil mapping.

Financing. The work was carried out on the topics of state tasks No. 0591-2019-0023 «To study the influence of natural conditions and land use features on the soil cover, including with the participation of saline saline and slitized soils and to develop a technology for assessing the intensity of exploitation of agricultural land soils» and No. AAAAA-A19-119012390065-9 «Development of methods for analysis and integrated use of remote sensing data based on modern geoinformation technologies for monitoring natural landscapes of agricultural lands using groups of small spacecrafts».

Acknowledgement. The authors express their gratitude to the employees of the Volgograd Hydrogeological and Reclamation Party for the data provided for the work.

DOI: 10.24412/1993-3916-2022-2-102-112

UDC 631.46:631.48:930

INFLUENCE OF SLOPE EXPOSURE ON CHEMICAL AND BIOLOGICAL PROPERTIES OF SOILS OF AGRICULTURAL TERRACES OF DAGESTAN

A.V. Potapova*, A.V. Borisov*

*Institute of physical, chemical and biological problems of soil science of the Russian Academy of Sciences

2a, Institutskaya Str., Moscow region, Pushchino, 142290, Russia. E-mail: pinskoy@inbox.ru

**Institute of Geology of the Dagestan Federal Research Center of the Russian Academy of Sciences

72 Yaragskogo Str., Makhachkala, Republic of Dagestan, 375000, Russia

Received 30.11.2021. Revised 30.11.2021. Accepted 01.12.2021

The study of the dependence of chemical and microbiological properties of soils of agricultural terraces of the middle mountain zone of the Eastern Caucasus formed on limestone and shale, on the exposure of the slope is presented in the article. It is established that the slope exposure significantly affects the properties of soils of the same type of soil-forming rocks. The formation of terraces with an arable surface close to horizontal changes the angle of incidence of sunlight, which leads to an increase in the heat supply of soils on the slopes of the northern exposure and a decrease on the southern slopes. As a result of the change in the thermal regime, in the upper horizon of terraced soils, the differences in chemical and microbiological properties on the slopes of the northern and southern exposures decreased, compared with the differences in the background soils that were not subjected to terracing. The leveling effect of terracing was more pronounced on gentle slopes of 5-15°, with the greatest width of the terraced canvas, compared with the soils of narrow terraces formed on steep slopes.

Keywords: Eastern Caucasus, agricultural terraces, slope exposure, chemical composition, biological activity.

Financing. Chemical and microbiological analyses were carried out with the financial support of the RFBR grant «Anthropogenic soils of agricultural terraces of the Caucasus» No. 19-29-05205, 2019. Field work in 2019 was carried out within the framework of State Task No. 0191-2019-0046.

DOI: 10.24412/1993-3916-2022-2-113-121

UDC 631.41

INFLUENCE OF TECHNOPEDOGENESIS ON THE MORPHOLOGICAL AND CHEMICAL PROPERTIES OF SOILS IN RECREATIONAL AREAS (BY THE EXAMPLE OF SASHA FILIPPOV PARK)

Federal State Budget Scientific Institution «Federal Scientific Centre of Agroecology, Complex Melioration and Protective Afforestation of the Russian Academy of Sciences»,

97, Universitetsky Ave., Volgograd, 400062, Russia. E-mail: oleg.gordienko.95@bk.ru

Received 06.08.2021. Revised 05.10.2021. Accepted 01.12.2021.

Soils of recreational areas of urban landscapes of Volgograd on the example of the Sasha Filippov park were studied. The soil cover of the park is represented mainly by typical (Urbic Technosol), replanted (Urbic Technosol (Mollic)), technogenic (Urbic Technosols (Hyperartefactic)) urbostratosems, replantazems (Phaeozem (Prototechnic)), and urbostratosems on buried chestnut soils. Under buildings and road pavements, screened urbostratosems (Ekranic Technosols). The presence of buried horizons suggests that the original soil cover in this area was represented by chestnut soils (Haplic Kastanozems (Loamic)). The average thickness of urbic horizons (UR) is 95 cm, reclamation layers (RAT) – 50 cm. The soils of the square vary in their chemical and physical properties. The content of soil carbon in the urban and reclamated horizons varies from 0.11 to 2.46%. Chemical analysis of the urban (UR) and reclaimed (RAT) horizons revealed a low content of readily soluble salts of 0.11% and carbonates of 1.1% and 1%, respectively. In the RAT and UR layers and anthropogenic horizons, the density values averaged 1.43-1.46 g/cm³. The density value of buried horizons averaged for BMK – 1.58 g/cm³, B – 1.62 g/cm³, BCA – 1.53 g/cm³, which is higher than the average density values for native chestnut soils. In the carbonate soil-forming rock Cca this indicator averaged 1.38 g/cm³. The obtained results allow us to study in more details the peculiarities of soil genesis in urban recreational areas and anthropogenic transformation of natural chestnut soils in the conditions of the dry-steppe natural zone.

Key words: recreational areas, soil classification, urban soils, urbostratozems, replantzemes, physical properties of soils, chemical properties of soils.

Financing. The work was carried out with the financial support of the Russian Foundation for Basic Research within the framework of the scientific project No. 20-34-90129 «Soils of recreational territories of Volgograd: diversity, properties, ecological functions».

DOI: 10.24412/1993-3916-2022-2-122-131

Arid Ecosystems

The “Arid Ecosystems” journal was organized by the decision of General Biology Division of the Russian Academy of Sciences.

Arid ecosystems. 2022. V.28. № 2 (91)