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PROBLEMS OF CASPIAN SEA LEVEL FORECASTING: LESSONS FROM HISTORY AND GUIDELINES FOR THE FUTURE (REVIEW)

Ecology and dynamics Опубликовано автором

S.I. Shaporenko, N.I. Koronkevich, Yu.A. Spirin, A.M. Abdurashidov Problems of Caspian Sea Level Forecasting: Lessons from History and Guidelines for the Future (Review) // Ecosystems: ecology and dynamics. No 2. 2026. P. 5-40. | Abstract | PDF | Reference

 

The long-term fluctuation of the average annual Caspian Sea Level (CSL) causes significant geoecological problems in its coastal zone. Solutions to these problems typically come from the reliable long-term forecasts of its water balance. The lowest drop in the mean sea level in the entire period of instrumental observations to a record low in 2025 (-29.02 m relative to the Makhachkala Tide Gauge Station) makes research into the processes that determine the hydrological regime of the sea even more urgent.

In this article we aim to identify the main reasons for the poor accuracy of long-term forecasts compared to short-term ones, based on a retrospective critical review of publications concerning predictive approaches to studying CSL fluctuation patterns. The main types of long-term forecasts are examined, including those using empirical relationships between the CSL and heliophysical processes, patterns of periodic and cyclical changes in phases of level rise and fall associated with changes in atmospheric circulation patterns, and other possible factors influencing the components of its water balance. It is established that, besides the natural complexities associated with forecasting climatic factors, the uncertainty of plans for the economic use of water resources in the Caspian basin also contributes to the inaccuracy of long-term forecasts. Such difficulties are not characteristic of short-term forecasts of seasonal and non-periodic level fluctuations.

In the absence of the possibility for long-term forecasting using clear predictors, all forecasts (both deterministic and probabilistic) are based on extrapolating identified patterns from previous periods, assuming that their main determining parameters will remain constant in the future. In the planned economy of the USSR, such an approach for forecasts exceeding three years was considered unacceptable due to large errors, even if the trend direction persisted. In the conditions of the Caspian catchment area, a change in this trend direction caused the maximum forecast errors, making it impossible to recommend this approach for solving economic planning problems.

A change in strategy is required, one based not on focusing on level forecasts, but on a mechanism for adapting the economy to the range of its variability within ecologically justified limits determined by the modern climate. An analysis of paleogeographic and historical sea-level data, which correspond well with the geomorphological features of the sea basin, provides specific quantitative indicators of level fluctuation. G.I. Rychagov called this range the risk zone and defined it within the interval from -30 m to -25 m, based on the natural flow of the Volga, or with an upper boundary of -26 m, accounting for irretrievable water withdrawal for economic needs.

The adaptation strategy may also include elements of level regulation, which were considered during the implementation of the “Greater Volga” project developed at the beginning of the 20th century, and incorporate short-term forecasting of water balance components as an important auxiliary element.

Keywords: elements of water balance; climatic and anthropogenic factors of formation; history, authors and forecasting methods; strategy of environmental management.

Funding. This work was carried out for the state assignment of the Institute of Geology of the Russian Academy of Sciences FMWS-2026-0003, No. 1025030300154-4, “Geographical and Hydrological Assessment of Changes in Water Resources in the Past, Present and Future in Various Natural and Economic Conditions”.

DOI: 10.24412/2542-2006-2026-2-5-40

EDN: XHFCJW

DYNAMIC CHANGES IN THE AREA WITH SURFACE-CARBONATE SOILS OBSERVED ON REMOTE SENSING DATA IN THE VOLGOGRAD REGION

Ecology and dynamics Опубликовано автором

Gorokhova I.N., Khitrov N.B., Kravchenko E.I. Dynamic Changes in the Area with Surface-Carbonate Soils Observed on Remote Sensing Data in the Volgograd Region // Ecosystems: ecology and dynamics. No 2. 2026. P. 41-60. | Abstract | PDF | Reference

 

 

We studied the dynamics of changing area of surface carbonate soils with the help of satellite images over a 30-year period of irrigation in 3 key areas that belong to different natural zones of the Volgograd Region: 1) the Northern Yergeni Upland (“Chervlenoe” massif), 2) the Caspian Depressiom, Khvalynsk Clay Plain – Northern Sarpa Lowland (Svetloyarsky massif), 3) the Caspian Depressiom, Khvalynsk Clay Plain – Sarpa Gully (Duboovrazhny massif). All 3 sites are located in the dry-steppe zone with an initial soil cover of light-chestnut solonetzic complexes. They differ in elevation, relief, parent and underlying rocks, groundwater levels, alkalinity, soil salinity, and the history of anthropogenic impacts associated with field planning, groundwater level rise, methods of plowing and irrigation, and crops. All sites have surface-carbonate soils, which were additionally confirmed by our fieldwork and laboratory data. We used Landsat-5 and Landsat-8 OLI satellite images for the period of 1985-2018 with a ground resolution of 30 m. Iindividual fields in the images were selected where surface patches were most evident, formed by the carbonates in the arable soil horizon (0-30 cm). The patches were analyzed for 3 different years, with intervals of 5-18 years. When processing images, we identified surface carbonate soils visually, interactively, and by unsupervised image classification that uses the IsoData method in the ENVI software package. These methods yielded different results, with a similar trend of growing areas of patched over the years, which may be caused by the following reasons: 1) the spreading of carbonates across the field during annual plowing, 2) the settling of carbonates that come from carbonate-saturated soil solutions during evaporation and water use by plant roots, 3) the plowing of carbonate horizons as the arable horizon gets eroded. According to the image classification method, the greatest increase in area is observed in the fields of the “Chervlenoe” (12.6 ha) and Svetloyarsky (11.0 ha) massifs over 23 and 33-year periods, respectively. In the fields of the Duboovrazhny massif, the increase was 4.2 ha over 11 years, since the planning of the fields during the construction of the irrigation system there was insignificant, and the period under consideration was shorter (11 years).

Keywords: light chestnut soils, irrigation, soil carbonates, field planning, space imagery classification, soil cover heterogeneity.

DOI: 10.24412/2542-2006-2026-2-41–60

EDN: YHZZYA

FLORISTIC TRANSFORMATIONS IN THE VALLEY OF THE UNITSA RIVER (MOSCOW REGION)

Ecology and dynamics Опубликовано автором

Shvetsov A.N., Kuklina A.G., Ozerova N.A. Floristic Transformations in the Valley of the Unitsa River (Moscow Region) // Ecosystems: ecology and dynamics. No 2. 2026. P. 93-61. | Abstract | PDF | Reference

 

 

During the field survey at the natural reserve “Unitsa River Valley” and adjacent territories (total area ≈300 ha) in the municipal district of Zaraysk, Moscow Region, a floristic list was compiled of 346 species of vascular plants. For the first time, the habitats of 3 rare taxa were identified: Anemone sylvestris, Gentiana cruciata, and Pulmonaria angustifolia, which are listed in the Red Data Book of the Moscow Region (2018). Among the identified species, 12 require regular monitoring. Among the 28 alien taxa found, there are 12 invasive and 5 potentially invasive species that tend to spread. A retrospective analysis using archives and documents has revealed several historical stages of the natural complexes in this reserve. It has been established that woody vegetation appeared in the basin of the Unica River (within the boundaries of specially protected area) in the last quarter of the 18th century, as a secondary forest at the site of deforestation. In the 1770-1950s, oak forests with birch mixed with linden and aspen were formed; natural resources were harnessed using traditional forest management techniques, cattle grazing and haymaking took place. In the 1950s and 2010s, as a result of human introduction activities, forest crops began to be grown in protected areas. At the current stage, starting in the 2010s, the structure and appearance of phytocenoses have shown signs of restoration of woody vegetation due to the presence of birch and aspen on old arable lands, meadow slopes of the Osetr River, and near-edge fallow lands. The most notable phenomenon of this period was the widespread expansion of Heracleum sosnowskyi, which poses the greatest threat to the natural complex of protected areas and has a detrimental effect on plant diversity and the overall ecosystem.

Keywords: specially protected natural areas, rare species, invasive species, Unitsa River, Zaraysk, Moscow Region.

Funding. This work was carried out for the agreement No. 09/27 on scientific cooperation between the Main Botanical Garden of the Russian Academy of Sciences and Institute for the History of Science and Technology of the Russian Academy of Sciences dated 09/27/2021, as well as the state assignments of the Main Botanical Garden, project No. 126020916823-0 “Biological Diversity, Resource Potential and Preservation of Natural And Cultural Flora under Climatic and Anthropogenic Changes», and the Institute for the History of Science and Technology, project No. 1022041500043-8-6.3.2 “Historical Vectors of Development of Geography and Geology in Russia: Identification of the Main Links between the Practice Requests and the Development of Geography and Geology, the Interaction of Individual Directions at Different Stages of the History of the Earth Sciences”.

Conflict of interest: The authors declare that there are no apparent or potential conflicts of interest related to the publication of this article.

DOI: 10.24412/2542-2006-2026-2-61-93

EDN: STFOIJ

ASSESSMENT OF THE ECOLOGICAL STATE OF URBAN WATER BODIES (TOGLIATTI, SAMARA REGION)

Ecology and dynamics Опубликовано автором

Zinchenko T.D.,  Tarasova N.G., Misyuk A.V.,  Morov V.P.  Assessment of the Ecological State of Urban Water Bodies (Togliatti, Samara Region) // Ecosystems: ecology and dynamics. No 2. 2026. P. 94-137. | Abstract | PDF | Reference

 

 

In this article we present the results of our comprehensive assessment the ecological state of Lake Plyazhnoe (Tolyatti, Samara Region) that was based on a certification of the condition of the lake and its recreational resources. In our study, we included data from our natural-geographical researches, data on the Quaternary geology and hydrogeology of the water protection zone and catchment area of the lake, hydrographic-hydrological, hydrochemical, hydrobiological, landscape-ecological, and sanitary-bacteriological indicators, integrated ecological characteristics, as well as recommendations for the lake’s restoration and preservation. Using both the results of hydrochemical and hydrobiological studies and an assessment of changes in the abundance and biomass of the main taxonomic groups of Lake Plyazhnoe that were conducted through various methodological approaches, we studied the dynamics of abiotic and biotic indicators. From the acquired set of abiotic environmental factors, we selected the most significant ones that determine the ecological state of the lake. Additionally, we determined its ecological status. Our study aims to promptly forecast critical ecological situations and to warn of environmental hazards when assessing the condition of water bodies.

Keywords: ecological state, Lake Plyazhnoe, lake basin, abiotic and biotic indicators, taxonomic diversity, Samara Region.

Funding. This work was carried out by the researchers of the Hydrobiology Laboratory, as part of the state assignment of the Ministry of Education and Science of the Russian Federation for the Samara Federal Research Center of the Russian Academy of Sciences, topic No. FMRW-2025-0046 “The Impact that Changes in Natural and Climatic Conditions Have on the State of Biodiversity and the Functioning of Natural and Anthropogenically Modified Ecosystems”, and of the Ecosystem Research Laboratory, topic No. FMRW-2025-0047 “Comprehensive Assessment of Biological Resources State and Monitoring of Natural Ecosystems of the Volga Basin”.

DOI: 10.24412/2542-2006-2026-2-94-137

EDN: UKMUQF