The article presents the results of the research, which are the basis of making a hydrodynamic model of the formation of drainage runoff of closed horizontal drainage on drainless and slightly drained irrigated lands in the dry steppe zone of Ukraine. The relevance of the research is in their need when designing the systems of horizontal drainage, determining drain spacing, modes of operation and the evaluation of drainage efficiency during its operation when irrigating with the use of modern sprinklers from a closed farm network. The objective of the research is to develop a generalized hydrodynamic model of formation of closed horizontal drainage runoff when irrigating from a closed farm network on drainless and slightly drained lands, which are typical for the watershed plains and coastal lowlands of the dry steppe zone of Ukraine. The task of the research to determine the basic conditions and factors of formation of horizontal drainage runoff, to specify the structure of groundwater inflow to the drains when having optimal drain spacing in the closed farm network and to define the prospects and areas of further research. Research methods and techniques: long-term (1975-2020) field experiments on drained areas with different drain spacing in typical hydrogeological conditions for watersheds and coastal lowlands; water balance studies; theoretical research methods (analysis and synthesis, comparison, generalization, zoning); to determine the structure of groundwater inflow to the drains, the method of electrohydrodynamic analogies when using the laboratory integrator EGDA 9/60 was applied. As a result of the research it was determined that in the conditions of a closed water farm network it is possible to increase drain spacing from 120-220 m to 240-400 m. When studying all the conditions of drainless and slightly drained watershed plains and coastal lowlands, the main sources forming the regime of groundwater and drainage runoff are the precipitation of 420 mm or 55.0% of water input, irrigation water - 340 mm or 45.0%, including 266 mm or 35,0% from irrigation and 75 mm or 10,0% from filtration from the canals. The analysis of the hydrodynamic model of drainage runoff formation shows that when having drain spacing as 240-400 m, the inflow from the zone located above the bottom of the drain is 2.6-4.8% of the total inflow to the drain. The ascending flow under the bottom of the drain enters it at an average angle of 600 and in all variants of drain spacing is 95.2-97.2% of the total inflow. When drain spacing increases from 240 to 300-400 m, the horizontal inflow from the area located below the bottom of the drain decreases with a corresponding increase in the ascending flow under the bottom of the drain. The average width of the ascending flow to the drain at the edge of the active zone of groundwater (9.0-10.0 m below the drain) is 13.0-20.0 m. The resulting model complements the existing theoretical and methodological knowledge base for designing horizontal drainage and is necessary in perspective researches on the formation of expert systems for optimization of the parameters and modes of irrigation and drainage functioning when applying modern broadcast sprinkler equipment irrigating from the closed farm network.
Досліджено сучасний стан та перспективи розвитку вищої освіти в Україні. Проаналізовано динаміку закладів вищої освіти в Україні та кількість студентів. Сьогодні в Україні спостерігається зниження за багатьма демографічними показниками, які мають вагомий вплив на освіту. У зв'язку з погіршенням демографії країни виникає проблема укомплектованості студентами закладів вищої освіти. Ця тенденція зі зниженням числа можливих студентів може спричинити скорочення вітчизняних вишів, закриття напрямів підготовки спеціалістів. Тенденція, що склалася, створює найбільшу загрозу для відтворення інтелектуального, культурного та професійного капіталу суспільства та можливостей економіки країни до інноваційного розвитку. Запропоновано шляхи розвитку вищої освіти в сучасних соціально-економічних умовах.
Problem formulation. Ecological quality of soils and agricultural products depends on the level of irrigation water mineralization. The quality of mineralized irrigation water has a negative impact on soils, agricultural products and ecosystems. This is especially negative in the conditions of Southern Ukraine within the Black Sea territories where the formation of irrigation waters in the Ingulets river basin depends on the influence of the Kryvyi Rih iron ore basin located in the river basin. The aim of the article is to assess the impact of mineralized irrigation waters on soils and natural ecosystems. Materials and methods. Field sampling of water and dark chestnut saline soils and southern chernozem soils to determine the impact of mineralized water quality on soils and ecosystems, statistical analysis of the obtained data. Results. Discharges of highly mineralized mine waters into the river basin lead to a change in the flow velocity in the river from 4 m³/s to 20 m³/s, which negatively affects the flora and fauna living conditions. Depending on the chemical composition of the discharges, the mineralization of irrigation water varies from 1.393 g/dm³ to 1.7608 g/dm³, and sometimes reaches 4.349 g/dm³. In terms of chemical composition, irrigation water is formed as a hydrocarbonate-sulfate-chloride with almost the same content of sulfates and chlorides, calcium-magnesium-sodium with a significant advantage of sodium. The dynamics of irrigation water quality indicators during 2013-2021 testifies to an increase of the most dangerous indicators for soils: hydrogen index of soil solution (pH) from 7.7 to 8.4, chlorine ion content (Cl–) – from 9.52 to 10.77 meq/dm³ and sodium (Na+) from 9.52 to 13.33 meq/dm³. By means of correlation and regression analyzes, the regularities of water hydrochemical composition formation were revealed and a strong functional connection between mineralization and chlorine ions (r = 0.99) and sulfate ions (r = 0.99), between mineralization and hydrocarbonate ions was established (r = 0.47). As the mineralization of water increases, the content of chlorine ions and sulfate ions increases proportionally, and hydrocarbonate ions play a secondary role in the formation of the hydrochemical composition. To prevent the chlorine ions excess of more than 350 meq/dm³ and sulfate ions excess – 500 meq/dm³, irrigation water mineralization should not exceed 1500 mg/dm³, and to prevent the chlorine ions excess of more than 350 meq/dm³, water flow from the canal should be at least 9.0 m³/s. Scientific novelty. New mathematical models of the irrigation water mineralization, its anionic composition, its chloride content dependence on water consumption from the Ingulets river and the interdependence between mineralization and cationic composition of water are offered. Practical significance. The obtained results are of practical importance for the implementation of agro-ameliorative measures for soil and ecosystem conservation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.