LUKIANETS O.I., GREBІN V.V. TIME DYNAMICS OF WATER BALANCE COMPONENTS IN THE PSEL RIVER BASIN

In the article, in order to identify the generalized role of changes that occurred in the Psel River basin with such climatic indicators as air temperature, amount of precipitation, their form of precipitation, the structure of water bodies feeding, as well as water flow in the modern period, the average water balance for a long-term period was calculated the Psel river basin near the town of Gadyach. In general, the water balance equation shows the ratio of water input and consumption within a river basin, taking into account changes in its reserves over a selected time interval and allows one to assess the relationship of its individual components. In the article identifies changes in the ratio between the inflow (amount of precipitation) and consumption of water (total evaporation and runoff) for two periods – the climatic norm of 1961-1990 and modern 1990-2019. Analysis of the temporal dynamics of the water balance components of the Psel river basin showed that the values of the water balance components within the Psel river basin near the town of Gadyach in the modern period have decreased in comparison with the period of the climatic norm – the amount of precipitation by 6,2%, water flow by 17,5%, evapotranspiration by 1,8%. But, analyzing the relationship between the inflow and outflow of water in the basin for the two study periods 1961-1990 and 1990-2019, it can be stated that during the period of the climatic norm, the percentage of water flow from the total precipitation was greater (coefficient water flow 16.2%) than in the modern period (coefficient water flow 14.2%). With regard to total evaporation in water-balance ratios, its share in the water-balance ratio has increased over the modern period (1990-2019). If during the period of climatic normal (1961-1990) the aridity coefficient was 83.8%, then in the modern period, it is 85.8%. That is, the “redistribution” of the water volumes of atmospheric precipitation took place towards the total evaporation with a decrease in the volume of water used to form the water runoff. For the basin of the river Psel – the city of Gadyach in the modern period on the average ≈ 11 mm (or ≈ 130000000 m3) evaporate instead of replenishment of water resources. In the previous period of 1961-1990, on the contrary, ≈ 12 mm (or 136000000 m3) did not evaporate, but flowed into the water bodies of the basin.

KHILCHEVSKYI V.K. CHARACTERISTICS OF WATER RESOURCES OF UKRAINE BASED ON THE DATABASE OF THE GLOBAL INFORMATION SYSTEM FAO AQUASTAT

The Food and Agriculture Organization of the United Nations (UN FAO) has the most advanced information on water resources in all countries of the world, since the share of the agriculture sector in world water use is 70%. It operates the FAO Global Information System on Water and Agriculture (abbreviated as FAO Aquastat). The data contained in this database comes from the relevant government bodies of the countries of the world (reports, publications, official websites), from information bases of other UN agencies or international organizations (UN WHO – World Health Organization; UN FPA – United Nations Population Fund; ICOLD – International Commission on Large Dams) or obtained by modeling. The Water Resources section of the FAO global information system contains about 40 indicators. The database is filled with the average values of indicators for the segments of years: 1988-1992; 1993-1997; 1998-2002; 2003-2007; 20008-2012; 2013-2017. The assessment of water resources carried out in the article based on the database of the global information system FAO Aquastat (1988-2017). showed the following results in Ukraine: internal river flow – 50.1 km3; inflow from adjacent territories – 120.2 km3; total river runoff – 170.3 km3; available groundwater reserves – 5 km3; internal renewable water resources – 55.1 km3; total renewable water resources – 175.3 km3. In terms of total renewable water resources per person (3964 m3/person/year) among 50 European countries as of 2017, Ukraine ranked 27th. In terms of internal renewable water resources per person (1246 m3/person/year), Ukraine ranked 37th in Europe. In terms of total renewable water resources (175.3 km3), Ukraine ranked 6th in Europe. In terms of the volume of internal renewable water resources (55.1 km3), Ukraine ranked 14th. Ukraine has a high coefficient of external dependence of water resources (Кз = 66.8%), which characterizes the share of total renewable water resources formed outside the country in adjacent territories – 9th place in Europe. The data on the components of water resources in Ukraine, which are given in FAO Aquastat, differ from the data published in Ukrainian sources. It is necessary to pay special attention to this methodological problem in the scientific and expert environment, as well as among officials in our country – the State Agency for Water Resources of Ukraine, the Ministry of Environmental Protection and Natural Resources of Ukraine. Indeed, with the course towards European integration, there can be no difference in information for internal and external use.

WATER MONITORING IN UKRAINE: METHODS FOR ASSESSING WATER QUALITY FOR VARIOUS PURPOSES IN CONNECTION WITH CHANGES IN THE REGULATORY FRAMEWORK (2014-2021)

Over the past five years (2014-2021), there have been significant changes in regulatory methods for assessing water quality for various purposes, which is due to Ukraine’s course towards European integration. An important feature was the cancellation of the acts of sanitary legislation of the Ukrainian SSR and the USSR (from 01.01.2017), which were applied in Ukraine for a long time (order of the Cabinet of Ministers of Ukraine of 2016). The Law of Ukraine “On Amendments to Certain Legislative Acts of Ukraine Concerning the Implementation of Integrated Approaches in Water Resources Management Based on the Basin Principle” (2016) amended the Water Code of Ukraine regarding hydrographic zoning and water monitoring in accordance with the provisions of the EU Water Framework Directive. In 2018, by a resolution of the Cabinet of Ministers of Ukraine, the “Procedure for the implementation of state monitoring of waters” was approved. In 2019, the Ministry of Natural Resources of Ukraine approved the normative “Methodology for assigning a surface water array to one of the classes of the ecological and chemical states of a surface water array, as well as assigning an artificial or significantly altered surface water array to one of the classes of the ecological potential of an artificial or significantly altered surface water array” The objects of state monitoring of waters are land and ground water bodies and sea waters. Surface water body – a specially defined surface water body or part of it. The body of surface waters can be classified into one of five categories: 1) rivers; 2) lakes; 3) transitional waters; 4) coastal waters; 5) artificial or substantially altered surface water bodies. The program of state monitoring of waters provides for control over four groups of indicators: 1) biological; 2) physical and chemical; 3) chemical; 4) hydromorphological. Based on the data and information obtained as a result of the state monitoring of the waters of surface and groundwater bodies, the ecological and chemical state of the surface water bodies, the ecological potential of artificial or significantly altered surface water bodies, the quantitative and chemical state of the groundwater bodies are determined, taking into account which river basin management plans and assess the level of achievement of environmental objectives. The purpose of this study is to highlight the approaches that have developed at the present stage to the regulation of water quality for various purposes, the main of which are: environmental; hygienic (household and drinking and cultural and household or recreational water use), fishery. If, when assessing the quality of water for environmental purposes, a deviation from the maximum permissible concentrations (MPC) was made, then in other areas of water use, the MPC standards remain relevant. The importance of this study also lies in the need to convey generalized information to a wide range of authors who are interested in water quality issues.

LARGE AND SMALL RESERVOIRS OF UKRAINE: REGIONAL AND BASIN DISTRIBUTION FEATURES

The aim of the study was to establish the territorial patterns of the distribution of reservoirs in administrative regions and river basin districts, to identify the role of large, medium and small reservoirs in the balance of river flow regulation in Ukraine. In Ukraine, there are only 1054 reservoirs, among which there are six large reservoirs of the Dnieper cascade and the Dniester reservoir, and all the remaining 99.3% (1047 reservoirs) belong to the middle (M), small (S) and very small (VS) categories. For convenience, we call this group with the abbreviation MSVS-reservoirs. All reservoirs have a total volume of 55.13 km3. Thus, reservoirs regulate 32% of the total river flow of the country, amounting to 170.3 km3 per year. There are two main patterns of territorial distribution of reservoirs: large reservoirs are located on large rivers (Dnieper and Dniester) and are of national importance; MSVS-reservoirs – were created to provide water to industrial regions (for example, Donetsk, Kharkiv) and have regional or local significance. In terms of the volume of accumulated water, Ukraine is a country of large reservoirs. The six reservoirs of the Dnieper cascade contain 79% of the water, in the Dniester – 6%, in the MSVS-reservoirs – 15%. The volume of reservoirs in the Dnieper cascade is 43.71 km3, which is 82% of the average long-term runoff of the Dnieper (53.5 km3 per year). The operation of the Dniester reservoir (3.0 km3), which was created in the transboundary city of Dniester (Ukraine – Moldova), is carried out taking into account the water management interests of the two countries. MSVS-reservoirs are unevenly distributed over the territory of Ukraine. The largest number of them is concentrated in the arid central and southeastern regions of Ukraine, 45% of the total number of MSVS-reservoirs is located in the region of the river basin Dnieper. The largest total values of the total volume and area of MSVS-reservoirs is in the Odesa region due to the Danube lakes, which have been granted the status of reservoirs. In the use of territorial communities in Ukraine, there are 72% of the MSVS-reservoirs, 28% – leased. Among the regions of Ukraine, most of all are rented MSVS-reservoirs in the Transcarpathian region – 78%. In the Zaporizhye region, 56% of the MSVS-reservoirs are leased, in the Ternopil region – 54%. There are leases of MSVS-reservoirs in Ivano-Frankivsk and Lviv regions. Low values of the lease indicator were in the Autonomous Republic of Crimea (4%), in Kherson (7%), Vinnitsa (8%) and Volyn regions (10% each). Among the regions of river basins, there are more leased MSVS-reservoirs in the regions of the river basins. Southern Bug – 35%, Dnieper – 32%. The minimum rental rate was in the region of the Crimean river basin (4%). There is a lease of MSVS-reservoirs in the area of the river basin. Vistula.

ZABOLOTSKA T.M., SHPYG V.M., TSILA A.YU. CIRCULATION INDEXES AND THE CLOUD COVER DURING OF THE GLOBAL WARMING PERIOD

The investigations of connection between the different meteorological processes, for example, the circulation indexes with the quantity of the total and lower cloudiness during 1961-2018 over Ukraine were made. The spatial distributions of the total and lower cloudiness were received for 73 years (1946-2018) at first. The quantity of cloudiness is diminished from west to east and with north to south. The declinations of the annual data of total and lower cloudiness from the historical (1961-1990) and the present (1981-2010) norms were calculated. The great variations were characterized for the lower cloudiness. The linear trends showed that the diminish of the lower cloudiness was on 90 % of the all territory, this changes were important on 70 % of the territory. The trends of the monthly variations were showed on the diminish of the lower cloudiness in during all year only on north, on other territory was the increasing in the separate months, frequently in January and September. The variations of the total cloudiness were insignificant, the increase or decrease were nearly in equal parts. North Atlantic Oscillation (NAO), Arctic Oscillation (AO), East-Atlantic Oscillation (EA), Scandinavian Oscillation (SCAND), Greenlandic Oscillation (GBI) and South Oscillation (El-Niño) were used for the investigation of relationship between the circulation indexes and cloud cover. It was shown that different circulation indexes have influence on climate of Northern Hemisphere and on Ukraine too. The relation with each other and their variations in period of global warming were showed. The quantity estimation of the total and lower cloudiness variations was made by the frequencies of clear, semi clear and overcast sky in the successive decades and by the relative variations of frequencies between decades (1961-1970 and 1971-1980; 1971-1980 and 1981-1990; 1981-1990 and 1991-2000; 1991-2000 and 2001-2010; 2001-2010 and 2011-2018). The parallel analyze of the variations of circulation was estimated in that time. The difference between the circulating processes during 1961-1970 and 1971-1980 contributed to a decrease in the relative frequency of the clear sky (on 5.4%) and a slight increase of the overcast sky (on 1.6%) by total cloud cover and a slight increase of the clear sky (on 0.8 %) and a decrease of the overcast sky (on 5.2%) by lower cloudiness. At the same time, the relative frequency of the semi-clear sky by lower cloudiness almost in three times increased in comparison to total cloudiness (on 10.2% and 3.8%, respectively). In the third decade of 1981-1990 the relative frequency of clear sky by lower cloudiness increased on 5.1% and did not change by total cloudiness (0%). During this decade the relative frequency of overcast sky decreased the most in the whole period under study: by total cloudiness on 6.4% and by lower cloudiness on 13.3%. At the same time, the relative frequency of semi-clear sky had largest increasing: on 22.4% for total cloudiness and 13% for lower cloudiness. Then, during 1991-2000, the frequency of clear sky decreased significantly both for total cloudiness (on 6.5%) and for lower cloudiness (on 3.1%). The frequency of overcast sky decreased also, but less significantly (on 1.3% and 2.3%, respectively), thereby the number of clouds of the middle and upper levels increased. From 2001 to 2010, the frequency of clear sky by total cloudiness and by lower cloudiness continued to decrease (on 5.3 and 3.2%, respectively), but the frequency of overcast sky increased (on 0.9 and 1.7%, respectively), thereby the number of clouds for all levels increased. During 2011-2018 the frequency of clear sky by total cloudiness increased (on 0.9%) and by lower cloudiness did not change. The frequency of overcast sky decreased on 3.6% (by total cloudiness) and on 0.7% (by lower cloudiness). The variations of the relative frequencies of the different state sky between the successive decades are agreed with the changes of the circulation indexes.

SOKUR K., PALAMARCHUK L. CONDITIONS FOR THE FORMATION OF SURFACE RUNOFF, WHICH IS FORMED AS A RESULT OF HEAVY AND DANGEROUS PRECIPITATION WITHIN URBANIZED AREAS

The research investigates atmospheric precipitation, which according to Ukrainian national regulation has reached the criteria of heavy (≥ 50 mm at ≤ 12 hours) and dangerous (15 – 49 mm at ≤ 12 hours). A total of 98 cases of heavy precipitation (2005 – 2018), and 14 cases of dangerous precipitation (2017 – 2018) were analyzed. The research focuses on the formation conditions and volumes of surface runoff that forms on various types of underlying surface. To obtain a statistically valid classification, a cluster analysis of heavy and dangerous precipitation was carried out. The analysis allowed to distinguish three blocks or clusters, one of which corresponds to the type “mix” of heavy and slight precipitations during the development of frontal stratus clouds with so-called “submerged or flooded” convection, the second cluster corresponds to the type “heavy precipitations”, the third cluster is similar to the first cluster, but is marked by a decrease in the intensity of processes. The degree of connection between the intensity of heavy precipitation and the height of the clouds top was investigated. As a result, it was found that there is an inverse relation between the values. The physical features of the processes of cloud and precipitation formation was considered. The exceptional role of convective clouds in individual frontal massifs and also in the form of “submerged or flooded convection” in the massifs of stratus clouds in the formation of significant volumes of rainwater on the underlying surface was noted. The structure of the temporal changes in precipitation intensity was established: the maximum intensity values, the time of their occurrence, the availability and number of amplification waves and their temporal parameters. On the basis of the obtained indicators, the quantity of the surface runoff for determined processes and for amplification periods were calculated. As a result, it was found that the surface runoff, which formed in the built-up areas, exceeds the surface runoff from the moderately built-up area with almost no artificial pavement by 100 – 300 %.

KHILCHEVSKYI V.K. MODERN CHARACTERISTICS OF WATER BODIES IN UKRAINE: WATERCOURSES AND RESERVOIRS

According to the assessment made in the article, the current data on the number of water bodies on the territory of Ukraine are: 63119 rivers; about 20 thousand lakes; 1054 reservoirs; 50793 ponds. There are rivers in Ukraine: large (> 50 thousand km2) – 8 rivers: Dnieper, Dniester, Danube, Desna, Pripyat, Southern Bug, Seversky Donets, Tisa; medium (2.0-50 thousand km2) – 82 rivers; small (<2.0 thousand km2) – 63,029 rivers (99.87%). There are lakes in Ukraine: very large (> 100 km2) – 1 lake: Yalpug; large (10-100 km2) – 21 lakes; medium (1-10 km2) – about 70; small (0.5-1.0 km2) and very small (<0.5 km2) - all other lakes (99.54%). There are reservoirs in Ukraine: very large (10-50 km3) – 2 reservoirs: Kremenchug and Kakhovskoe – on the river.Dnipro (0.2%); large (1.0-10 km3) – 5 reservoirs; Kievskoe,Kanevskoe, Kamenskoe, Dneprovskoe (on the Dnieper river), Dnestrovsky – on the Dniester (0.5%); medium (0.1-1.0 km3) – 11 reservoirs (1.0%); small (0.01-0.1 km3) – 88 reservoirs (8.4%); small (<0.01 km3) – 948 reservoirs (89.9%). There are ponds in Ukraine: very large (> 500 thousand m3) and large (200-500 thousand m3) – 13%; medium (50-200 thousand m3) – 29%; small (10-50 thousand m3) and very small (<10 thousand m3) - 58%. Of great importance was the approval by the Verkhovna Rada of Ukraine in 2016 of the hydrographic zoning of the territory of Ukraine with the allocation of 9 regions of river basins: the Dnieper, Dniester, Danube, Southern Bug, Don, Vistula, Crimean rivers Black Sea rivers, Azov rivers. Almost all rivers of Ukraine belong to the basin of the Black and Azov seas. In addition to the area of the river basin Vistula (Western Bug and San rivers) which belongs to the Baltic Sea basin and occupies only 2.5% of the country's territory. It is shown that since hydrographic studies in Ukraine were carried out more than 50 years ago, modern hydrographic surveys of the country’s territory with the creation of a modern water cadastre and the establishment of real morphometric parameters of water bodies (rivers, lakes, reservoirs, ponds) are necessary. The main organizations dealing with these issues are the State Agency for Water Resources of Ukraine and the Ukrainian Hydrometeorological Center of the State Service of Ukraine for Emergency Situations. It is also necessary to regulate a number of concepts that are used a priori, but do not have a definition, clear parameters (for example, a stream, a source, a digging pond, etc.). This is difficult to implement through the Water Code of Ukraine or state standards, but it can be easier to do through the officially approved methods in which these terms are used.

NATIONAL HYDROMETEOROLOGICAL SERVICE IN UKRAINE IS 100 YEARS OLD: THE ROLE OF GRADUATES-HYDROLOGISTS OF TARAS SHEVCHENKO UNIVERSITY OF KYIV IN ITS ACTIVITIES

On November 19, 2021, the National Hydrometeorological Service in Ukraine celebrates its 100th anniversary. On this day in 1921. Kh. Rakovsky, Chairman of the Council of People’s Commissars of the Ukrainian SSR, signed a decree “On the meteorological service in Ukraine.” The creation in 1929 of the Hydrometeorological Center of the Committee under the Council of People’s Commissars of the Ukrainian SSR (Gimek), which united meteorological and hydrological observations in one department, marked the emergence of a single hydrometeorological service. In 1999, the Verkhovna Rada of Ukraine adopted the Law “On hydrometeorological activity”, in which the concept of “national hydrometeorological service” appeared for the first time in Ukraine. Over the years of activity, starting from 1921, the national hydrometeorological service in Ukraine has gone through a difficult path of formation and various subordination (from civil service to military service during the Second World War in 1941-1945). The article identifies six periods in the history of the activity of the national hydrometeorological service in Ukraine: 1st period – until 1921; 2nd – 1921-1941; 3rd – 1941-1945; 4th – 1946-1991; 5th – 1991-2011; 6th – since 2011 The hydrometeorological service reached its highest status in 1991-1999, when the State Committee of Ukraine for Hydrometeorology (the central executive body) operated. In connection with the reforms of public administration structures, since 2011, the status of the national hydrometeorological service in Ukraine has significantly decreased – to the level of the hydrometeorology department within the State Emergency Service of Ukraine. Today, the main production institution within the State Emergency Service of Ukraine is the Ukrainian Hydrometeorological Center, which directs all organizations that carry out operational hydrometeorological observations in the regions. In 1949, at the Kiev State University named after T.G. Shevchenko established the Department of Land Hydrology, headed by Professor V.A. Nazarov is an experienced scientist from the hydrometeorological service. One of the main tasks of the department was the training of specialists-hydrologists for the hydrometeorological service. The article describes the contribution of the hydrological department (1949-2021) of the Taras Shevchenko National University of Kyiv to strengthening the human resources of the national hydrometeorological service of Ukraine, briefly highlights the activities of some graduates of the department who, with their own efforts, contributed to the development of the national hydrometeorological service of Ukraine, each at his own workplace:.V.M. Lipinskyi, V.O. Gromovyi, V.O. Manukalo V.I. Osadchyi, V.V. Derevets, O.O. Kosovets, V.M. Boyko, M.I. Dovhych, O.V. Serebryakov, V.M. Manivchuk.

DYNAMICS OF TURBIDITY OF RIVER WATER ON THE LEFT-BANK TRIBUTARIES OF THE DNIEPER (ON THE EXAMPLE OF THE SUMY REGION)

The article is devoted to the study of sediment runoff, especially one of the characteristics that reflects erosion processes in the catchment area, water turbidity using the example of the rivers of the Sumy region. The main purpose of the article is the spatial and temporal analysis of the turbidity indicators of the rivers of the Sumy region (left-bank tributaries of the Dnieper). The article highlights information on the sediment runoff of the rivers in the region for the entire period of observations, describes modern own studies of the turbidity of river water and establishes the features of the formation of sediment runoff in the rivers of the region. It was found that the indicators of turbidity of river water grow in the direction from north to south of the study area, in the zone of mixed forests are minimal, and in the forest-steppe – maximum; high values of the average turbidity index characteristic of small rivers in the region, аmong the average rivers, the maximum values were recorded for the Sula and Vorskla rivers; during floods, turbidity values are maximum, and during low water periods, they are minimal; there is a tendency to an increase in the indicators of maximum and average turbidity of river water. Particular attention is paid to the influence of river regulation on turbidity indicators. It was found that the deceleration of water exchange is facilitated by the accumulation of sediments in the channel above the dam (high indicators of the thickness of the silt layer), and also below the dam (the creation of a channel island, probably due to the uneven throughput of the dam’s gate valves, which creates a different flow rate from the right and left banks). Decreased flow velocity, increased water turbidity and, as a consequence, siltation, deterioration of river water quality (appearance of swamp odor, decrease in transparency, color change) leads to changes in the species composition of aquatic organisms, extinction of river species and the appearance of atypical river species, overgrowth. In their conclusions, the authors argue that sediment runoff is formed mainly due to washout from the surface of the catchment area, high turbidity indicators in rivers whose basin is more prone to erosion, where the indicators of plowing of the basin surface are maximum, water protection zones and coastal protective belts are destroyed, but when studying the turbidity of river water it is necessary take into account additional factors.

“AGROHYDROCHEMISTRY” (2021) – A CONTRIBUTION TO THE IMPLEMENTATION OF THE PROVISIONS OF THE “NITRATE DIRECTIVE” 91/676 / EEC IN UKRAINE

The article presents and analyzes the textbook “Agrohydrochemistry” (author V.K. Khilchevsky – professor of the Taras Shevchenko National University of Kyiv), published in 2021. The textbook examines the main problems associated with the growth of the chemicalization of agriculture and the protection of water resources. Due to agriculture, there is a noticeable impact on the quality of natural waters in the world, especially in regions of intensive agriculture, to which Ukraine belongs. Increased concentrations of nutrients and various types of pesticides are found in the waters of small and large rivers, groundwater. Therefore, the issues of studying the main sources of agricultural pollution of natural waters and the processes that contribute to this are relevant. Among the main sources of pollution of natural waters with wastewater, namely industrial, household and agricultural – the latter have a specific character of formation and flow into water bodies. If industrial and domestic wastewater is localized behind the formation and place of discharge into the sewer network, then the formation and supply of chemicals from agricultural land is dispersed throughout the catchment area and natural ways of entering (hydrographic network) into water bodies. The attention of the world community to the impact of agrochemicals on the quality of natural waters is evidenced by the Directive 91/676/EU adopted in the European Union of December 12, 1991 “On the protection of waters from pollution caused by nitrates from agricultural sources” (abbreviated as “Nitrogen Directive”), which in turn is a local manifestation of the integrating directive 2000/60/EC of October 23, 2000 “On the establishment of a framework for Community activities in the field of water policy” (abbreviated WFD – “EU Water Framework Directive”), aimed at achieving a good ecological state of natural waters in the regions river basins. Agrohydrochemistry is a direction in hydrochemistry that studies the effect of agrochemical agents on the chemical composition of natural waters using theoretical methods and the results of experimental studies in watersheds. The textbook, which consists of 9 chapters, gives an idea of the formation of the balance of chemicals in the soil, the use of various types of fertilizers and pesticides, and the possible ways of their entry into water bodies. Methods for calculating the flow of chemicals into water bodies are presented. The theoretical provisions are illustrated by the materials of our own research on the effect of agrochemicals on the chemical composition of river waters in the Dnieper basin. The textbook is designed for students of the specialty “Earth Sciences” of educational programs of the hydrological profile of higher educational institutions..