Journal of Ecological Engineering Journal of Ecological Engineering 2021, 22(9), 119–127 Received: 2021.07.15 https://doi.org/10.12911/22998993/141370 Accepted: 2021.08.25 ISSN 2299-8993, License CC-BY 4.0 Published: 2021.09.01 Spatio-Temporal Analysis of the Ecological State of the Dniester River Transboundary Water Iryna Shakhman1, Anastasiia Bystriantseva1* 1 Kherson State University, Universitetska Str., 27, Kherson, 73000, Ukraine * Corresponding author’s e-mail: [email protected] ABSTRACT The ecological state of transboundary water of the Dniester River Basin was analyzed in the context of cross-bor- der cooperation. The major objects of economic activity affecting the state of transboundary water were identified in the Dniester River Basin in Ukraine and Republic of Moldova. It was established that over the years of trans- boundary cooperation, a decrease in the average annual concentrations of Suspended solids, Nitrites, Chlorides and Sulfates below the maximum permissible values was achieved. The ecological state of the Dniester River transboundary water in time and space was investigated using an integral assessment of the state of the Dniester River water environment. It is recommended to assess the transboundary water ecological state using complex indices. An assessment of the ecological reliability of the Dniester River Basin transboundary water in 2020 was carried out. The research results show that the use of transboundary water of the Dniester River Basin is potentially dangerous. Further cooperation between Ukraine and the Republic of Moldova in the issue of reducing the waste- water containing harmful substances with a synergistic effect, is encouraged. Keywords: the Dniester River, ecological state, transboundary water, complex assessment. INTRODUCTION their ability to self-purification potential as well as capability of restoration remain relevant. Water resources (surface, underground and sea) The degradation of water resources, especially are national wealth, the natural basis for the econom- in the context of climate change, still leaves on ic and social well-being of the people of any country. the agenda the issue of transboundary water co- They support livelihoods for people, flora and fauna operation – integrated water resources manage- and are limited and vulnerable, especially when it ment (taking into account the economic inter- comes to transboundary water resources and bodies. ests of the development of coastal neighboring According to the current estimations, trans- countries and the protection of water resources). boundary surface water bodies (river basins and The Dniester River basin is located on the lakes) occupy almost half of the planet’s land territory of the Republic of Poland (0.6% of surface. About 40% of the world’s population the catchment area), the Republic of Moldova lives in the basins of transboundary rivers and (26.4%), but most of it (73.0%) is located within lakes that are shared by two or more countries, Ukraine (Lvivska, Ivano-Frankivska, Cherniv- over 90% of people inhabit the countries that etska, Ternopilska, Khmelnytska, Vinnytska and share basins [Basin United Nations]. The inten- Odeska regions) [Website of the Dniester Com- sive use of surface water resources by neighbor- mission]. The Dniester River Basin is bounded ing coastal countries for the needs of industry, from the west by the Carpathians, from the north- agriculture, energy, transport leads to a change west – by the Sano-Dniester watershed, from the in the ecological state of transboundary ba- north – by Rostoch, from the south-east – by the sins. Therefore, the water quality monitoring of Dnieper-Bug firth, from the west – by the Dnies- transboundary water bodies and assessment of ter-Prut and Dniester-Black Sea watersheds. 119 Journal of Ecological Engineering 2021, 22(9), 119–127 The length of the Dniester River is 1362 km, decrease in the use of water, both from surface and the catchment area is 68627 km2, the average underground sources, in all sectors of the econo- stream gradient is 0.56‰. Ukraine owns the head- my. The water management situation in the Dni- water and the mouth stretch of the river with a ester River Basin demonstrates a different combi- total length of 705 km. The 220 km section of the nation of changes in the volume of water intake river is transboundary for Ukraine and Moldova. and the volume of discharge of polluted water over The middle and lower parts (437 km long) of the time. For example, for the period 2015–2019, the river are located in Moldova. A small section of volume of water intake from the territory of the the Strvyazh River (the headwater of left tributary Khmelnytska region decreased by 22.4%, Vin- of the Dniester River) belongs to the Republic of nytska – by 9.8%, while the volumes of polluted Poland [Website of the Dniester Commission]. water discharge from the territory of these regions The Dniester River is the main source of wa- increased by 55.9% and 8.9%, respectively. The ter for Moldova and, to a large extent, for Ukraine. water intake from the Dniester River Basin in the There are 157 settlements (5 million people) on Ivano-Frankivska region during the period under the territory of the basin within Ukraine, where- review increased by 5.6%, and the discharge of as on the territory of Moldova – 43 settlements polluted water decreased by 6.9% [Ministry of En- (2.74 million people). Outside the basin, another vironmental Protection and Natural Resources of 3.5 million people consume the Dniester water Ukraine, Dniester Basin Water Resources Manage- [Website of the Dniester Commission]. The west- ment]. Significant amount of water removed from ern region is the best-resourced of the local runoff natural sources is still lost when it is transported to of Ukraine, where 200–600 thousand m3 of water water users, as a result of filtration, leaks, and ac- falls per 1 km2 of territory, and 2–6 thousand m3 of cidents in water supply systems from the point of water per inhabitant [Agricultural Policy Report]. water intake to the point of its use. The main factors of the anthropogenic load Enterprises of Moldova also have a negative on surface water resources are both significant impact on the ecological state of transboundary water consumption by various sectors of the surface water (metallurgical plant, Ribnita; ce- economy of Ukraine and the Republic of Mol- ment plants in Ribnita and Rezina) [Website of dova, and discharges of polluted water. The neg- the Dniester Commission]. The total volume of ative impact on the ecosystem of the river from water use in the Republic of Moldova is distrib- the source to the mouth is very severe and it is uted as follows: utility needs 14% (112.7 million caused by the production activity of oil refiner- m3), industrial needs – 74% (582.8 million m3), ies, chemical plants, and enterprises in the coal, irrigation – 5% (41.5 million m3), agriculture and food, forestry, utilities, energy, and agriculture. water supply to rural settlements – 4% (38.2 mil- Most environmentally hazardous enterprises are lion m3), other needs – 3% (2.2 million m3). The located in the upper part of the Dniester basin annual water intake from the Dniester River Ba- (Lvivska, Ivano-Frankivska regions), where sin by the Republic of Moldova is 754.0 million 70% of the runoff is formed. There are powerful m3 (96%). The total volume of discharged water enterprises (the largest surface water pollutants in the country reaches 667.0 million m3, of which of the Dniester River) on the territory of Lvivs- 661.8 million m3 (99%) falls on the Dniester Riv- ka and Ivano-Frankivska regions: PSP “Lvivska er Basin [Website of the Dniester Commission]. Coal Company”, PE Mine “Stepova” SE “Lviv Stream flow control significantly affects the Coal”, PSP “Petrochemical of Prykarpattia”, ecological state of the Dniester River. 65 reser- LLC “Carpathian Petrochemical”, Nadvirna oil voirs and 3447 ponds were built on the territory and gas production division, Oriana Open Joint- of the river basin. In the middle course of the riv- Stock Company [Ministry of Environmental er, a cascade of channel reservoirs has been built, Protection and Natural Resources of Ukraine]. the largest of which are Dubasari and Dniester The current water consumption of the Dni- reservoirs. Violation of the continuity of the wa- ester River basin water resources by Ukraine is ter flow, water intake, and water level fluctuations distributed as follows: production needs are 52%, negatively affect the ecological state of the river. non-refundable use is 25%, municipal services are The agriculture developed on the territory of 17% and agricultural needs are 6% [Transbound- Ukraine and the Republic of Moldova (crops and ary river basin management plan]. The temporal vegetables output, horticulture, livestock) leads trends of water use in the basin indicate a general to the pollution of water bodies with mineral 120 Journal of Ecological Engineering 2021, 22(9), 119–127 fertilizers and pesticides. The arable land in the obtained by different monitoring subjects to differ Dniester River Basin reaches 43%. This fac- significantly [Odnorih et al., 2020]. tor and untreated wastewater have the greatest Observations of the surface water quality of negative impact on the ecological state of trans- the Dniester River Basin on the border areas of boundary surface waters [Transboundary river Ukraine and the Republic of Moldova are car- basin management plan]. ried out at transboundary points. Three points For the sustainable development of both are located before the entrance of the Dniester States, Ukraine and the Republic of Moldova, a water into the territory of the Republic of Mol- Treaty on Cooperation in the Field of Protection dova (near the village Naslavcea, city Mohyliv- and Sustainable Development of the Dniester Podil’s’kyi, village Tsikinivka) and four – on the River Basin was signed on November 29, 2012 tributaries of the Dniester River on the territory in Rome [Agreement between the Cabinet of of the Odeska region (Ukraine), after the exit of Ministers of Ukraine and the Government of the watercourses from the territory of the Republic of Republic of Moldova].