- No. 1(9) 2026
«Meteorology. Hydrology. Environmental monitoring»
- 5page
UKRAINIAN HYDROMETEOROLOGICAL INSTITUTE OF THE STATE EMERGENCY OF UKRAINE AND THE NATIONAL ACADEMY OF SCIENCES OF UKRAINE, KYIV
Анотація Full version of the article DOI: pp. 5-15
“UKRAINIAN HYDROMETEOROLOGICAL INSTITUTE OF THE STATE EMERGENCY OF UKRAINE AND THE NATIONAL ACADEMY OF SCIENCES OF UKRAINE, KYIV
This article presents the results of calculations and analysis of the spatio-temporal distribution of “cloud-ground” lightning strikes in Ukraine during the period 2017–2021, based on data from the lightning detection system of the Ukrainian Hydrometeorological Institute, which includes 12 sensors located in different regions of the country. The total number of ground lightning strikes and their density (number of lightning strikes per 1 km² - l/km² ) within each administrative region were analyzed. The average lightning density over the five-year period was 0.89 per 1 km², with an average annual number of approximately 539,000 lightning strikes. The highest lightning densities were observed in Odesa (1.34 l/km²), Zaporizhzhia (1.15 l/ km²), Mykolaiv (1.14 l/km²), Ivano-Frankivsk (1.08 l/km²), Vinnytsia (1.05 l/km²), and Zakarpattia (1.05 l/km²) regions. The lowest values were recorded in Sumy (0.54 l/km²), Kharkiv (0.59 l/km²), Chernihiv (0.63 l/km²), and Volyn (0.65 l/km²) regions. The greatest total number of lightning strikes across Ukraine was registered in 2018 (658,000), while the lowest was in 2020 (322,000). It was additionally established that the seasonal maximum of thunderstorm activity occurs in June–July, when the most intense convective systems are formed. Regional differences in the intensity of cloud-to-ground lightning discharges are based on the combination of thermodynamic and orographic factors. The analysis of interannual variability revealed a strong dependence of lightning occurrence on the type of atmospheric circulation and the conditions favorable for the development of atmospheric convection. The obtained results enhance the understanding of contemporary features of thunderstorm activity in Ukraine and can be used to assess territories in terms of lightning strike risk, improve early-warning systems, and support safety planning. Furthermore, they may serve as a basis for further research in climate monitoring and the analysis of extreme atmospheric phenomena.
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OZONE VERTICAL DISTRIBUTION IN THE UPPER TROPOSPHERE – LOWER STRATOSPHERE OVER UKRAINE BASED ON THE EAC4 REANALYSIS DATA
Анотація Full version of the article DOI: pp. 16-25
“OZONE VERTICAL DISTRIBUTION IN THE UPPER TROPOSPHERE – LOWER STRATOSPHERE OVER UKRAINE BASED ON THE EAC4 REANALYSIS DATA
The paper examines the vertical distribution of O3 over the territory of Ukraine in the upper troposphere – lower stratosphere layer, its seasonal variability, and interannual trends. The study was conducted using data from the European Centre for Medium-Range Weather Forecasts (ECMWF) Atmospheric Composition Reanalysis 4 (EAC4) for the period 2003–2023. It is shown that the vertical distribution of O3 below the 30 hPa isobaric level is primarily shaped by the dominant role of the Brewer–Dobson circulation, whereas above this level photochemical reactions become the determining factor. According to EAC4 data, the long-term mean O3 maxima at these levels reach 12 mg/kg, decreasing to 2 mg/kg in the upper troposphere. The EAC4 reanalysis is shown to overestimate the altitudes at which the maximum O3 content is observed (10–20 hPa), compared with the mean levels derived from observations (30–50 hPa). Depending on the season, the timing of higher concentrations varies with altitude. Up to the 30 hPa level, winter–spring O3 maxima prevail as a result of transport by the Brewer–Dobson circulation, whereas above this level, summer maxima occur due to more intensive photochemical production. During the study period, a decrease in O3 was identified in the 50–100 hPa layer (16–20 km), occurring most intensively in the summer and winter seasons, with a decline rate of 0.02 mg/kg per year. In contrast, above the 10 hPa level (above 30 km), O3 increases due to interannual changes in the spring season, with an upward trend of approximately 0.03 mg/kg per year. The obtained results provide an important addition to the known patterns of O3 distribution over Ukraine in terms of identifying the causes of ozone layer variability, which may have implications for the frequency of elevated levels of ultraviolet radiation harmful to human health and ecosystems.
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MODERN CONDITIONS OF HUMIDIFICATION IN THE NORTH OF UKRAINE
Анотація Full version of the article DOI: pp. 26-34
“MODERN CONDITIONS OF HUMIDIFICATION IN THE NORTH OF UKRAINE
The increase in the frequency of intense heat waves and droughts in the European region due to climate change highlights a clear trend towards aridity for the South and East of Ukraine, while in the northern region, against the backdrop of rising air temperatures, changes in precipitation patterns are of a more complex nature. The study used average monthly precipitation amounts for 17 meteorological stations in the northern regions of Ukraine (Zhytomyr, Kyiv, Chernihiv and Sumy). Conducted a comparative analysis of indicators for two climatological periods (1961-1990 and 1991-2020), as well as a detailed analysis of changes in moisture over the last decade (2011-2020) in terms of increasing anomaly of the temperature-humidity regime during this period. Changes in the average monthly rainfall amounts show a tendency toward dryness in April, in summer (with a maximum in August), and for most stations in the North of the country from November to January (with a minimum in January). Monthly precipitation amounts increased noticeably in May and October (in Kyiv and Chernihiv regions in some places by 20 mm or more) and, for most stations, in February-March and September. The greatest variability in precipitation fields observed in the last decade (2011-2020). On average, a precipitation deficit observed at the stations in 43-53% of the months, while normal precipitation slightly exceeded the share of months with deficient moisture (except for Zhytomyr and Kyiv). During the warm season, there is a tendency toward drought for all 17 stations in the northern region (in 49-61% of months), while in the cold season, normal distribution or excess moisture predominates, except for Kyiv region, where drought persists except for Yahotyn. Periods of significant excess moisture (200-400% of the norm) were observed in both warm and cold seasons, with January-February, December, and October often being wet. The processes of circulation in the formation of the largest precipitation anomalies have been considered. Extreme humidity conditions were caused by large-scale processes, without taking regional characteristics into account – intense precipitation in southern and western cyclones and a lack of precipitation during blocking processes both in summer and in winter.
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CARBOHYDRATES AS AN IMPORTANT COMPONENT OF NATURAL ORGANIC SUBSTANCES IN SURFACE WATERS
Анотація Full version of the article DOI: pp. 35-49
“CARBOHYDRATES AS AN IMPORTANT COMPONENT OF NATURAL ORGANIC SUBSTANCES IN SURFACE WATERS
Results of long-term studies on dissolved carbohydrates in various surface water bodies in Ukraine (lakes, rivers, and reservoirs) are presented. Dissolved carbohydrates are the second most abundant natural organic compounds after humic substances. Their concentrations vary widely, ranging from 0.19 to 5.43 mg/L (as glucose), and their contribution to total organic carbon (Corg) ranges from 2.2 to 36.1% (on average 4.7–16.4% Corg). Concentrations largely depend on the type of water body and its trophic status, as well as on the development of phytoplankton and higher aquatic vegetation, which are the primary sources of carbohydrates. Maximum concentrations are observed in small, urbanized water bodies with significant anthropogenic impact and high nutrient content Most of these are highly eutrophic water bodies, where phytoplankton and higher aquatic vegetation develop intensively. This explains the high concentrations of carbohydrates. The maximum concentration of dissolved carbohydrates is observed during the summer–autumn season. According to gel chromatography studies, dissolved carbohydrates are represented by compounds with a wide molecular weight range – from <1.0 to >70.0 kDa. Polysaccharides dominate, constituting on average 67.7–83.7% of the total dissolved carbohydrate content. This is likely due to the predominance of polymeric compounds released actively by algae. Low-molecular-weight compounds (<1.0 kDa) account for 16.3–32.3%. Seasonal variations of low-molecular-weight carbohydrates are discussed. The greatest transformation of high-molecular-weight carbohydrate fractions occurs in summer, when water temperature rises and internal water processes are activated, particularly with the participation of microflora.
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EVALUATION OF WATER-SALT REGIME PARAMETERS FOR THE INHULETS RIVER IN THE TECHNOGENIC AFFECTED ZONE BASED ON HYDROCHEMICAL MONITORING DATA
Анотація Full version of the article DOI: pp. 50-61
“EVALUATION OF WATER-SALT REGIME PARAMETERS FOR THE INHULETS RIVER IN THE TECHNOGENIC AFFECTED ZONE BASED ON HYDROCHEMICAL MONITORING DATA
The need to supply consumers with adequate quality water in the south of the Dnipropetrovsk region and water for irrigation in the Kherson and Mykolaiv regions requires thorough studying the features of the water-salt regime of the technogenically mostly loaded section of the Inhulets River, which is the purpose of this paper. Unlike previous studies of this section of the Inhulets River, which dealt primarily with average concentrations in river water and long-term trends, an analysis of state water monitoring data was conducted with a frequency of once every 1–3 months, involving data on daily water flows in two sections for 6 years along with results from satellite surveying, the state hydrochemical monitoring data were analyzed to study the water-salt regime of the Inhulets River within the section of approximately 70 km length, situated between the Karachunivske dam reservoir and the village of Andriyivka. 22 short periods in 2014–2019 were examined in detail, during which the flow rate of the Inhulets River, discharges from the Saksahanske reservoir, and the anion contents in water in the upper and lower reaches of the river section were measured. Statistical analysis with water-salt balance equations assessed the technogenic and natural factors influencing the discharge of the Inhulets River and the increase in its water salinity. It was found that the anion content in river water after passing through the studied section during periods without extensive mine-water discharges increases by almost 1.5 times. This gives a quantitative assessment of the technogenic impact on the hydrogeochemical regime in the considered part of the Inhulets River valley. The share of chlorides in river water increases after passing through this area, on average, from 20–22% to 38% during periods without mine water discharges and 68% during periods with discharges from the mine water storage pond. The practical significance of the results is determined by the quantitative assessment of water losses and changes in water quality when using this section of the Inhulets Riverbed to transport fresh water to the southern areas of the Dnipropetrovsk region, where water supplies were disrupted following the destruction of the Kakhovka HPP dam.
- 62page
DECOMPOSITION, MODELING AND FORECASTING OF THE TIME SERIES OF DISCHARGE OF THE DESNA RIVER USING THE “BSTS” PACKAGE OF THE R PROGRAMMING LANGUAGE
Анотація Full version of the article DOI: pp. 62-70
“DECOMPOSITION, MODELING AND FORECASTING OF THE TIME SERIES OF DISCHARGE OF THE DESNA RIVER USING THE “BSTS” PACKAGE OF THE R PROGRAMMING LANGUAGE
Qualitative forecasting of river water levels is an important component for planning and functioning of various water-dependent sectors of the economy: agriculture and municipal services, hydropower, fisheries, shipping, etc. Forecasting of river daily discharges is based on both simple graphical methods and deterministic and stochastic models. The article is devoted to the use of the “bsts” package of the R programming language for modeling and forecasting daily discharges of the Desna River – Litky village. After decomposition of the time series of daily discharges was found that these series consist of three components: a trend, a seasonal component, and random fluctuations. In the process of creating the 'bsts' model, the main functions of the 'bsts' package, which form the various components of this model, were considered: add.seasonal, add.local.level, add.ar, add.local. linear.trend, add.semilocal. linear.trend and add.student.local.linear.trend. The results of modeling the daily discharges of the training and test samples were evaluated using five statistical indicators: residual.sd, prediction.sd, rsquare, relative.gof та МАРЕ, and also by the accumulated error curve of the next step. The optimal model is the “bsts” - model without predictors, which models daily discharges using the add.student.local.linear.trend function and random fluctuations. This model is suitable for short-term forecasting of daily discharges of the Desna River – Litky village during periods of their long and smooth increase or decrease, as well as during periods of stable low water levels. Forecasting daily discharges using the 'bsts' - model is based on a trend that relates this model to forecasting based on spring flood decline curves, which take into account the depletion of water reserves in the channel network, and trends that take into account the inertia of hydrological processes.
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RADIATION STATE OF THE EXCLUSION ZONE OF 2025 IN ACCORDANCE WITH THE RESULTS OF RADIATION ENVIRONMENTAL MONITORING
Анотація Full version of the article DOI: pp. 71-86
“RADIATION STATE OF THE EXCLUSION ZONE OF 2025 IN ACCORDANCE WITH THE RESULTS OF RADIATION ENVIRONMENTAL MONITORING
The article presents results of radiation and environmental monitoring in the Exclusion Zone for the year 2025. According to the results of radiation and environmental monitoring in the Exclusion Zone in 2025, important analytical data were obtained: - Maximum power values of the ambient dose equivalent of gamma radiation are characteristic of the territories in the northern and western 'traces' of radioactive fallout; - Radiation state of the Exclusion Zone air environment and its dynamics during 2025 were determined by the nature of surface contamination of the territory, сontrol levels exceeding activity in the air was recorded; - Surface waters remain an important route of radionuclide removal beyond the Exclusion Zone; - Radiation state of underground waters, radionuclide contamination of eocene and cenomanian-lower cretaceous water-bearing complexes; - Monitoring results at landscape landfills; - Radiation survey results of unauthorized residence places of the population in the Exclusion Zone. Compared to 2024, the average annual value of the volumetric activity of 137Cs and 90Sr in the surface layer of the atmosphere of the Chernobyl Nuclear Power Plant remained approximately at the same level or slightly decreased. In 2025, the discharge of 90Sr from the Pripyat River in the Chernobyl zone was 3.2 times less than in 2024 and 2.5 times less than the average value of the last 5 years. The inflow of 90Sr from outside the exclusion zone did not exceed 32% of the total discharge from the Pripyat River. The content of 90Sr was recorded in all observation wells. The maximum values of the volumetric activity of 90Sr in the waters of the Quaternary aquifer complex were recorded in the areas of the old Budbaza, Lake Azbuchyn, and Yanivskyi Zaton, and were 140, 66, and 57 Bq/dm3.
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RESULTS OF FIELD SURVEYS OF PLOTS FOR VALIDATION OF MONITORING ASSESSMENT OF LAND DEGRADATION IN THE KINGDOM OF MOROCCO BASED ON HETEROGENEOUS DATA
ARTICLE 1. PLAIN ARID TERRITORYАнотація Full version of the article DOI: pp. 87-105
“RESULTS OF FIELD SURVEYS OF PLOTS FOR VALIDATION OF MONITORING ASSESSMENT OF LAND DEGRADATION IN THE KINGDOM OF MOROCCO BASED ON HETEROGENEOUS DATA
ARTICLE 1. PLAIN ARID TERRITORYField studies of the conditions of the landscape components of the territory were conducted within 22 observation sites planned on the route (profile) along the Tensift River to northward of of the city of Marrakech, Morocco. Features of their current state (development, supression, distortion, toxic pollution, changes from one to another, complete or partial absence of certain components, etc.) have been characterized, photographed, filmed, and descriptively documented. The proper factual material has been entered into a database created within the framework of a geographic information system. As a result of a comprehensive qualitative analysis of the characteristics of the state of landscape components, they were transfered into a single quantitative parameter of the land degradation class of this area from the 1st (most degraded) to the 5th (practically not degraded). The algorithm for integrating the descriptively recorded indicators consisted of a kind of “summation” – devised by the authors – of the qualitatively assessed condition of each landscape component at a specific observation site; and, as a result of this comprehensive analysis, the determination of an integrated quantitative indicator of land degradation class. In this context, the so-called “reference” 5th class was taken as the qualitatively assessed state, within the oases, of practically the same landscape components, where the main focus of the criteria was on the condition of the vegetation cover (particularly the presence and development of palm trees). In the studied area, the 1st class of degradation was assessed at one survey site, at eight sites – as the 2nd, at seven sites – as the 3rd, at six sites – as the 4th. No sites with the 5th degree of land degradation were recorded within the studied area.
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ON THE STUDY OF THE MECHANISM OF EXCESS SURFACE WATER DISCHARGE USING GEOPHYSICAL OBSERVATIONS
Анотація Full version of the article DOI: pp. 106-113
“ON THE STUDY OF THE MECHANISM OF EXCESS SURFACE WATER DISCHARGE USING GEOPHYSICAL OBSERVATIONS
The study is devoted to investigating the impact of large-scale water discharge from the Karachunivske Reservoir on hydrogeodynamic processes within the geological environment of the Southern Kryvbas using geophysical methods. The main objective of the research was to assess the influence of mining activities in the open pit on the Inhulets River and adjacent geological structures. The research methodology is based on monitoring field observations carried out using geophysical techniques, including electrical prospecting, particularly the method of natural field (self-potential), as well as gravimetric surveys. The obtained results demonstrate that a sharp increase in the water level in the Inhulets River leads to intensive infiltration of excessive surface waters into the sedimentary cover and tectonically disturbed zones. This process significantly alters the hydrogeodynamic state of rocks and contributes to the activation of landslide processes within the study area. The analysis of geophysical data revealed a clear dependence of the natural field potential and its gradient on the processes of water saturation of the geological medium. In addition, the key role of tectonic faults in controlling the pathways of water filtration and redistribution within the subsurface has been established. It has been determined that in areas with open fault systems, water penetrates deeper into the geological section, whereas in zones with closed fault systems, it spreads laterally within interlayer spaces. These processes are reflected in the spatial distribution of geophysical parameters and confirm the sensitivity of the natural field method to changes in hydrogeological conditions. The scientific novelty of the study lies in confirming the effectiveness of the natural field method for investigating the mechanisms of rapid water saturation of geological formations and identifying pathways of surface water migration into underground horizons. Furthermore, the results substantiate the applicability of this method for environmental monitoring of flooded and landslide-prone areas, as well as for the optimization of observation networks and early detection of hazardous geological processes in mining regions.
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MAPPING OF AVERAGE ANNUAL RIVER RUNOFF WITHIN THE RIVER BASIN DISTRICTS OF UKRAINE USING GIS TOOLS
Анотація Full version of the article DOI: pp. 114-123
“MAPPING OF AVERAGE ANNUAL RIVER RUNOFF WITHIN THE RIVER BASIN DISTRICTS OF UKRAINE USING GIS TOOLS
Ukraine has adopted the principles of integrated water resources management based on the river basin approach, under which river basin districts serve as the fundamental units for water use regulation, protection, and restoration. Within this framework, the development of River Basin Management Plans (RBMPs) requires reliable hydrological characteristics of surface water bodies. In particular, data on average annual water discharge with a 50% probability of exceedance are necessary for the analysis of key RBMP components, including the assessment of pressures, impacts, and water availability at the basin scale. However, the uneven distribution of hydrological monitoring stations limits the direct application of observational data in basin-scale analyses. This study presents a geographic information system (GIS)-based approach to mapping the spatial distribution of average annual water runoff modules with a 50% probability of exceedance across the territory of Ukraine. Using modern geoinformation technologies, a digital elevation model was generated, catchment areas of hydrological gauging stations were delineated, and their centre of the catchment were determined. Based on these inputs, an interpolation surface of average annual runoff modules was constructed, enabling the automated extraction of runoff characteristics at any point within the study area. A detailed analysis of spatial variability in average annual runoff modules was performed for nine river basin districts of Ukraine. The identified spatial patterns reflect the influence of physical-geographical zonation and altitudinal differentiation, highlighting the controlling role of natural factors in runoff formation. The developed interpolation surface minimizes subjective influences inherent in traditional assessment approaches and provides an objective, reproducible tool for hydrological analysis. The results indicate that the generated interpolation surface can be effectively used in the preparation of River Basin Management Plans for all river basin districts of Ukraine, contributing to evidence-based water resources management at the national scale.
