The research goal was to study changes in the hydrothermal regime of the arable soil layer after packing its surface. Leached chernozem was chosen as an object for the study of the hydrothermal regime. The experimental plots were located in the climatic zone of the arid splitting steppe. The objectives of the study included: to monitor changes in soil moisture when packing its surface and to consider the impact of this agricultural technology on moisture conservation in the arable layer as well as to study the tendency of changes in the temperature regime of the arable soil layer when packing its surface and, based on this, to consider the possibility of using this agricultural technique for thermal soil reclamation. The conducted studies have shown that on the packed surface of the black steam, in contrast to the surface without packing, a noticeable layer of the dried soil is formed, which has a moisture-saving effect on the underlying layers. Reducing the parameters of the pore space of the soil and improving the conductive thermal conductivity when rolling contributes to faster warming of the soil compared to the site without rolling. The revealed features allow us to say that packing as an agricultural technology can be used to preserve moisture in the arable layer, especially in spring, as well as to increase the amount of active temperatures in the arable layer.

The purpose of the study is to determine the directions of improvement of the «Volga-SM» multi-support sprinkler machines with a polyethylene pipeline and to assess their efficiency. The article presents the research results of a new multi-support sprinkler with cable-stayed construction «Volga-SM». The peculiarity of this machine is that the water pipeline consists of a steel pipeline that provides sufficient rigidity of the spans, and a polyethylene pipeline installed parallel to the steel pipeline. Depending on the length of the machine and water consumption, the parameters of a small-diameter steel pipeline 102...114 mm and a polyethylene pipeline with a diameter of 63...160 mm are substantiated. Resource saving of the «Volga-SM» DM has been substantiated by reducing the pressure at the inlet to the machine from 0.45.0.6 to 0.35.0.5 MPa (by 20.28%), reducing the mass of the water-conducting pipeline and the number of support bogies. The ability to supply fertilizer solutions only through a polyethylene pipeline and near-surface sprinklers reduces corrosion of the pipeline and structural elements of the machine, which increases the reliability of the machine and its service life. The main advantages of the modernized cable-stayed machine with a polyethylene pipeline are presented.

The aim of the investigation is to study the agro-climatic resources of the Sana’a basin to substantiate the productivity of agricultural crops under the conditions of dry farming taking into consideration the established level of agricultural production, especially agro technical, water, chemical, reclamation anti-erosion measures. There is given a concept of agro climatic resources of the territory. The classification of agricultural plants developed on the basis of climatic and ecological principles and based on agro-climatic indicators which characterize the need of plants in heat, illumination and moisture is presented. An assessment of the thermal and light resources of the Sana’a basin was carried out for natural-agricultural mountainous regions with relatively homogeneous mesoclimatic conditions.

The process of operation of structures (products, silicon alloys,) as a result of natural carbonation, partial decomposition of calcium hydrosilicates occurs with the formation of secondary calcite and polysilic acid gel. The basis of silicon-oxygen anions of low molecular solubility, characterizes the degree of polymerization of the silicon-containing part: for samples from structures of a 2-year operation. This allows us to conclude about the ongoing chemical reactions between the silica component of the volcanic rock and the free Ca (OH)2, which leads to an increase in the volume of the gel-like component and, as a result, the hardening of expanded clay concrete. The research results indicate that the formation of a hardened contact layer on the surface of the expanded clay aggregate as a result of the chemical interaction of Ca (OH) 2 and sulfate ion with the glass phase of the filler, as well as the mutual overlap of the fields of the contact layers, due to their development and relatively low consumption of the binder material, presupposes the creation of expanded clay concrete structures with high performance.

The paper presents the results of theoretical and experimental substantiation of the use of injection flow regulators with a new form of flow part. A distinctive feature of the structures is a complete change in the end section of the regulator. The output cross-section of the transit water outlet is placed in the downstream and has a diaphragm with edges cut down the stream and partial lateral flow clamping. There is no diffuser at the end section, the output of the flow into the volume of the downstream takes place directly from the prismatic mixing chamber, which has a constant area. A method for theoretical calculation of hydraulic parameters of injection flow regulators with a diaphragm without diffuser output areas has been developed. The validity of the use of theoretical dependencies to determine the hydraulic characteristics of the structure and the effectiveness of the proposed changes in the form of the flowing part have been proven. Injection regulators without diffusers are capable of taking up to 30% of the excess from the downstream flow and ensuring its circulation between the outlet section of the outlet and the mixing chamber. The increase in the regulating capacity compared to existing designs of injection water outlets is due to the optimization of the diaphragm design.

The article presents the results of the development of three-dimensional modeling and the results of forecasting the pollution of a water body with biogenic elements on the example of the Pekhorka River in the Balashikhinsky district of the Moscow region. To solve the problem of improving the environmental safety of the river basin, a mathematical three-dimensional model for predicting pollution by biogenic elements has been developed. As an assessment of the pollution of the Pekhorka River, the method of assessing the impact on the indicator of chemical pollution was chosen. The development of a mathematical model of pollutant transport was carried out using the Python Version 3.8 programming environment. The mathematical models considered two scenarios of river pollution: actual river pollution with biogenic pollutants and forecast pollution. As a result of modeling, the nature of mixing and longitudinal dispersion along the river flow was determined. It was found that vertical mixing occurs quite quickly at a distance of several depths of the river, lateral mixing occurs much slower, but usually ends within a few kilometers downstream. Three-dimensional mathematical models for predicting water body pollution are designed to quantify the dynamic processes of mass transfer in space and time and allow solving problems of environmental safety of catchment areas and water bodies.

The purpose of the work is to conduct research aimed at identifying dangerous areas adjacent to the village of Babugent as a result of changes in the channel processes at the confluence of the Cherek Balkarsky and Cherek Bezengiysky rivers. On this site, field surveys of channels were carried out, the sharp changes of which began with the construction of a dam for the Kashkhatau hydroelectric power plant 1 km downstream. As a result of the field survey, areas with a large amount of deposited material in the beds of the Cherek Balkarsky and Cherek Bezengiysky rivers were identified, as well as erosion of the coastal slope of the floodplain terrace, where the rural cemetery is located. According to the data of the field work, calculations were carried out to determine the height of the water level depending on the maximum flow rates of flood water of different percentage provision. Based on the results of the calculations and field surveys, the zones of flooding and underflooding of the territories of the Babugent village, which is located between the Cherek Balkarsky and Cherek Bezengiysky rivers, have been determined. 22 household plots and households of the private sector of the village fall into the zone of flooding and underflooding. Recommendations are given on carrying out the necessary measures to ensure the safety of people’s livelihood and the infrastructure of the village.

The purpose of the study is to assess the possibilities of combining the processes of mixing coagulant and agitating (formation of flocculant), developing, designing and testing the installation that ensures the compatibility of processes and the use of compressed air in the mixing process to achieve standard indicators of drinking water quality at the lowest possible economic costs. The article contains the results of research to assess the possibilities of achieving the quality indicators of drinking water from surface sources of the Syrian Arab Republic in conditions of regulated runoff. The experiments used water from reservoir 16 Tishrin, as a coagulant aqueous aluminum sulfate [Al₂(SO)₃.₁₈H₂O], water samples for experiments were stored until a temperature close to ambient temperature was reached. A combination of a flocculation chamber and a mixer for a water purification plant is proposed, as well as a method for using compressed air as a mixing factor instead of mechanical mixers. Before the start of the experiment, measurements of the temperature and pH of the water were carried out, as well as the calculation of the amount of air required to perform the processes of mixing and the formation of a flocculant. Due to the combination of the mixer and the flocculation chamber, the possibility of increasing the efficiency of water purification and reducing operating costs when using compressed air for mixing has been established; it has also been possible to determine the optimal values of the parameters of mixing and mixing processes used in water treatment; to improve mixing efficiency and water purification quality; to reduce operating costs for water treatment; to optimize the layout of individual elements of the water treatment system.

The design and calculation of pipelines taking into account the mutual influence of local resistances is an urgent task in the hydraulics of pressure flows. The analysis and results of the hydraulic calculation of the Valtec metal-polymer pipeline are given, taking into account the lengths of the influence of local resistances of their mutual influence (interference). Tabular data on the lengths of influence of local resistances, coefficients of mutual influence used in the developed program of the Delhi (Object Pascal) environment are given. A graph of the dependence of specific pressure losses per 1 meter of pipeline length on the flow rate for the Valtec pipeline with an equivalent roughness of Ae/ d = 0.007 mm, obtained experimentally and data for a similar pipeline according to the reference data tables with an equivalent roughness of Ae / d = 0.01 mm, is presented. The results of the calculations and the interface of the Delphi 7 environment application program with the data in a tabular form for the hydraulic calculation of the total pressure losses in pipelines are shown, taking into account reference and experimental values of coefficients of local resistances. The data of the results of the hydraulic calculation of the total head losses, taking into account the specific linear pressure loss per 1 meter of the pipeline length without local resistances, are given to determine the head losses by length. The developed program can be used in the design, layout and hydraulic calculation of metal-polymer pipelines with specified parameters.

The aim of the study is to study the phenotypic structure and diversity of spruce populations in the state reserve «Kologrivsky forest». The reserve is located in the conditions of natural hybridization of Siberian spruce and European spruce with the formation of intermediate forms. The relevance of studying the variability and population structure of spruce in the region is due to the need for understanding its intraspecific differentiation and microevolution in the zone of introgressive hybridization, preservation of the gene pool, and the need for its selective improvement as the main source of wood. The collection of experimental material was carried out in the summer of 2020 on the territory of the reserve in two areas isolated from each other (Kologrivsky and Manturovsky). The phenotypic structure of populations was determined by a comprehensive assessment of traits and by the shape of the seed scales. Spruce populations in the state reserve «Kologrivsky forest» are characterized by significant polymorphism of traits. The results obtained for the complex indicator are consistent with the estimates of the occurrence of phenotypes by the shape of the seed scales. Phenotypes of intermediate forms of spruce are predominant in the territory. The variety of spruces under these conditions can be used in forestry in the selection and substantiation of the most productive and stable phenotypes, as well as in the isolation and preservation of the population gene pool.

The purpose of the research is to establish the need for maintenance logging in artificial 16-19-year-old plantings of various compositions using a comprehensive evaluation indicator. The purpose of the research work is to increase the durability of artificially created plantings in the study area based on the improvement of methods of logging maintenance. The data obtained will make it possible to assess the effectiveness of forestry measures. The species composition of the green zone of the city of Nursultan is mainly represented by plantings of elm, ash-leaved maple, tree willow, narrow-leaved loch, warty birch, common pine. There are practically no practical recommendations for carrying out forestry care for these species growing in the steppe zone, the subzone of dry tipchak-kovyl steppes with a sharply continental climate. Work on the study of the impact of logging care in plantings of various formations of the green zone of the city of Nursultan has not been carried out before, which determines the scientific novelty of the project. The practical significance of the work is that the results obtained can be used to predict the growth and productivity of plantings in similar forest growing conditions.