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EN
The article considers issues of ensuring sustainable agricultural production by increasing reliability of an irrigation system and water security. The article describes results of hydraulic tests performed at the water outlet with a vertical movement valve member. Resistance coefficients and hydrodynamic effects at the water outlet were determined experimentally. The study developed a method for calculating hydromechanical transient processes in the water outlet at the stop and start of the pump. The paper substantiates the new construction of a water outlet facility with a vertical displacement of the breakdown valve. Such a design better corresponds to peculiarities of the operation of pumping stations and, if there are water pipes of considerable diameter, it has a positive effect on transition hydrodynamic processes by reducing the number of failures and downtime by up to 10%.
EN
Monitoring of surface waters within the transboundary section of the Western Bug River showed, that during 2014–2018, a significant excess of the maximum permissible concentration (MPC) was observed for some substances for fish ponds. As a result of this, the water in the river for these substances was rated as “dirty” in terms of purity and corresponded to water quality class IV, namely: phosphorus was observed to exceed the MPC at the observation point Ambukіv village in 2015 (9.7 times), for manganese – an excess of the MPC at the observation point Ambukіv village in 2018 (9.7 times) and in point Zabuzhzhia village in 2014 (7.9 times), 2015 (8.0 times), 2017 (7.1 times), 2018 (8.3 times); for the total iron – the exceeding of MPC at the observation point Ambukіv village in 2016 (5.95 times) and 2017 (6.13 times); at the observation point Ustilug town in 2016 (5.23 times); in the observation point Zabuzhzhia village in 2016 (9.44 times) and 2017 (5.27 times). The assessment of the surface waters based on the determination of the pollution factor showed that during the study period their quality did not deteriorate but did not meet the norms. In general, surface waters of the river correspond to the second class of quality and are characterized as “poorly polluted” waters by the level of pollution.
EN
The article discusses the option for the application of the methodology for the solution of boundary value problems on the conformal mapping for the calculation of filtration process in the horizontal systematic drainage, provided that the drain is installed at a different depth. In particular, the case of methods combining fictitious areas and quasiconformal mappings for solving nonlinear boundary conditions problems for calculating filtration regimes in soils with free sections of boundaries (depression curves) and intervals of the “drainage” type. As an example, the authors designed a hydrodynamic flow grid, determined the values of the flows to the drain, established a section line and elicited other process characteristics. The algorithm for the numerical solution of model nonlinear boundary conditions problems of quasiconformal reflection in areas bounded by two equipotential lines and two flow lines, when for one of the sections, the boundary is an unknown (free) curve with fixed and free ends. The conducted numerical calculations prove that the problems and algorithms of their numerical solution, with a relatively small iterations number (k = 141) suggested in the paper, can be applied in the simulation of nonlinear filtration processes that arise in horizontal drainage systems. Total filtration flow obtained Q = 0.9 dm3∙s–1; flow for drains Q1 = 0.55 dm3∙s–1 and Q2 = 0.35 dm3∙s–1 are quite consistent with practically determined values.
EN
The presence of water, food and energy crises, both at the global and regional levels, as well as their deterioration under conditions of climate change, with an insufficient level of technical condition of existing irrigation systems, increase the strategic importance of irrigation as the guarantor of the agricultural sector sustainable development. This makes it necessary to increase, foremost, energy and overall (technical, technological, economic, and environmental) efficiency of the closed irrigation network of irrigation systems. In this regard, the complex that includes organisational-technological, technical, and resource-saving groups of measures was developed. Estimation of energy and overall efficiency of the closed irrigation network of irrigation systems at the implementation of developed complex were executed on the example of the agricultural enterprise located in the Petropavlovsk district of the Dnipropetrovsk region of Ukraine. For this purpose, machine experiment based on a use of the set of optimisation, forecasting and simulation models was implemented, including the model of climatic conditions, the model of water regime and water regulation technologies, as well as the model of crop yields on reclaimed lands. According to the obtained results, established that implementation of the complex reduces the consumption of irrigation water by 2.2-30.7% and electricity consumption by 12.9-38.2%. The rate of specific costs decreases from 1.6 to 1.32-1.47, and the coefficient of environmental reliability increases by 5.6-16.7%. At the same time, the profitability index increases from 1.07 to 1.75-2.57, and the discounted payback period decreases from 18 to 8-5 years.
EN
In modern conditions, there are cardinal climate changes on the Earth as at the planetary scale, as at the regional level. According to numerous hydrometeorological characteristics and indicators, climatologists specialists concluded that Ukraine also take place significant climatic changes in the last 10–25 years. In complicated natural-technical systems, which include irrigation and drainage systems (IDS) on drained lands, the selection of regime-technological and technical solutions on different levels of the decision including the time, should be based on the appropriate meteorological information for selecting climatologically optimal management strategies for such systems in the long-term and annual periods. The decisive influence on the formation of water and the overall natural reclamation modes of reclaimed land and harvest crops in many cases depends exactly from climate or weather conditions. Thus, it is necessary to have available data about their implementation to the relevant object as for number of previous years retrospective observations and the forecast period of functioning of the object. Therefore, forecasting of weather and climate conditions become an indispensable condition for implementation of assessing the overall effectiveness of IDS operation. To solve this problem we performed large-scale computer experiment for multi-year retrospective and current data observations in the area of Zhytomyr Polissya. Were planned and implemented the following variants of studies - «Base», «Transitional», «Recent», «CCCM», «UKMO». The forecast was done for five years of typical groups of vegetation periods regarding conditions of heat and moisture provision (very wet - 10%, wet - 30%, average - 50%, dry - 70%, very dry - 90%) on such basic meteorological characteristics: air temperature; precipitation; relative air humidity; deficit of air humidity; photosynthetically active radiation (PAR); coefficient of moisture provision (the ratio of precipitation to evapotranspiration). Obtained results of comparative assessment of climatic conditions in Zhytomyr Polissya zone, suggests that for most of the basic meteorological parameters, already there are changes that in the short term may exceed 10% of the critical ecological threshold, which will lead to relevant irreversible changes in the state of the environment in the region.
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