The modern concept of irrigation development in the Russian Federation is based on research and development works on the creation of new irrigation equipment and technologies. Particular emphasis is placed on the widespread introduction of automation, energy saving, the possibility of using modern digital solutions. The introduction of automation on reclamation systems in Russia is constrained not only by the low level of their technical condition, but also by the signifi cant remoteness of automation facilities from power supply sources. The purpose of the research is to develop an automated measuring complex capable of monitoring the level mode of an open reclamation network, atmospheric pressure and temperature with data transmission to the server and subsequent analysis of monitoring data for user-defi ned conditions. The developed automatic measuring complex can work both from batteries and from a renewable energy source – solar panels. The schematic diagram of the complex and the results of experimental tests of the prototype in laboratory and fi eld conditions are given. The capabilities of a special computer program that analyzes monitoring data are described. The accuracy of measuring atmospheric pressure at a temperature of 25°C is ± 0.12 hPa. The accuracy of measuring the temperature of atmospheric air ± 1°C, measuring range lies within –40..+85°C. In the presence of wave phenomena and the absence of a fl oat well, the main absolute error in measuring the level is 0.02 m. In tests at a height of the installation from 0.4 to 2.0 m above the static water level, the main absolute error is 0.01 m. 

The purpose of the study is to analyze models of plant requirements for the regulation of the water regime of soils to substantiate the range of optimal humidity and its control based on automation and digitalization in accordance with the algorithm for controlling the moisture regime of reclaimed soils. The substantiation of the requirements of plants to the regulation of the water regime of soils and its control is presented. The analysis of models of dependencies of agricultural productivity on the formation of the water regime of the soil to substantiate reclamation (irrigation) is carried out. Four approaches to the development of models of this orientation are given, graphs of the requirements of the main crops to soil moisture reserves are built, in relation to loamy soils. Dynamic calculations of the required moisture reserves in the soil according to the phases of plant development for grain crops are carried out, allowing regulating the water regime in more detail, taking into account the development of production processes. The accuracy of calculations according to the model of Shabanov V.V. is confi rmed by microbiological studies. Based on the conducted fi eld studies and according to the data available in the public domain, comparative analyses of moisture sensors were performed and recommendations were made to improve the accuracy of soil moisture control within reasonable optimal ranges. To carry out accurate reclamation, it is necessary not only to perform model calculations of the optimal humidity ranges for the phases of plant development, but also to control the soil moisture values with suffi cient measurement accuracy with modern equipment, to carry out controlled watering with the introduction of automation and digitalization. 

The purpose of the research is to reduce the period between the snow melt and the readiness of the soil for cultivation on weakly sloped lands with characteristic seasonal freezing and the formation of temporary aquifers in the form of perched water in early spring, as well as to ensure the required water-air regime of the soil at different time of crops cultivation. The object of the study is horizontal closed drainage systems. A multifunctional two-tier drainage and humidification system is proposed, the drains of which are connected to closed collectors of the lower and upper tiers, respectively. In the mouth zone, the collector of the upper tier is connected to the collector of the lower tier and a hydraulic valve is installed above the point of their connection in the collector of the lower tier. The operation of the system in the drainage mode occurs in two stages. At the first stage, the upper tier works, ensuring the removal of excess water from the thawed topsoil layer in early spring. At the second stage, after complete seasonal thawing, in addition to the drains of the first tier, the drains of the lower tier are included in the work. Joint work in the drainage mode of the upper and lower tiers ensures the required humidity of the topsoil layer and maintains the groundwater level at a level corresponding to the drainage rate. In the dry period, water from the canal, entering the mouth of the collector system, with the help of a hydraulic valve, blocks the collector of the lower tier and continues to fill the upper tier system, supplying water to the root layer of the soil. 

The subject of research is the development of a method for calculating the water consumption of red clover using data on evaporation from the water surface, aimed at improving the accuracy of its determination and saving water resources, in the watersheds of the non-chernozem zone of Russia. The object of research on the total water consumption of red clover is turf-podzolic soils and soil moisture of watershed areas, when growing fodder crops. Experimental tests were carried out on plots, in lysimeters and laboratories, in different meteorological conditions years. In the processing and analysis of scientific research, the doctrine of groundwater fl ow, data from lysimetric studies, and data from field experiments, correlation and regressive analysis were used. Water balance studies were carried out on a scientific basis located in the Moscow region, according to the methodology developed by Yu.N. Nikolsky, V.V. Pchelkin. Experiments conducted in lysimeters and plots in 2015… 2017, served as the basis for the development of a formula for determining the water consumption of red clover using evaporation from the water surface in the watersheds of the non-chernozem zone of Russia. 

The purpose of our work is to determine the causes of overwetting of the territory, to design a temporary pre-drainage system that ensures the effective removal of excess water during the construction of a permanent drainage system in the conditions of the Academician Sakharov Park. The main causes for excessive moisture withinthe object are: humid climate(precipitation exceeds evaporation by 2.8 times), shallow occurrence of the aquifer confining layer, high ground water position, which leads to the formation of headwater lenses during the year. According to climatic and hydrogeological studies, prior drainage should be carried out before starting work on the construction of a drainage system. The article considers in detail the design features of the water drawdown and dewatering, as well as the stages of construction. According to calculations on dewatering in the conditions of the Academician Sakharov Park with the capacity of the drained aquifer1.0…1.4 m, the average depth of the confining layer 2.0 …2.3 m and trench lengths from 110 …225 m, the time for drainage is 5…6 days, and the estimated infl ow of water to the mouth of the trench is within 3.29…3.85m³/day. To ensure effective work on dewatering from a trench with lengths of up to 225 m and with a drained aquifer capacity of up to 1.4 in the hydrogeological conditions of the territory of the Sakharov Park, it is recommended to use domestic pumping and power equipment of the «Vihr» type DN-400 with a fl ow rate of 11.5 m³/h. 

The main objective of the study is to determine the agro-economic requirements of leading agricultural crops to agro-climatic and soil-reclamation conditions, for the subsequent identification of possible areas of cultivation in the conditions of rain-fed and irrigated agriculture of the Sanaa basin. The data available in scientific sources on the agro-economic requirements of leading agricultural crops are summarized, the long-term experience of farmers within the boundaries of mountainous natural and agricultural areas is studied, and additional studies of the requirements of leading agricultural crops to the environmental conditions of the basin of Sana’a, including the duration of the growing season, average sowing time and planting, temperature and light conditions, soil conditions, fertilizer needs, sensitivity to salinization, water needs, the depth of the root system by stages of development. The data obtained on the agro-economic requirements of the leading agricultural crops were compared with the land, agro-climatic and soil-reclamation conditions of the mountainous natural and agricultural areas of the Sanaa basin. Conclusions are drawn about possible areas of cultivation of leading agricultural crops in the conditions of rain-fed and irrigated agriculture. 

The article uses geophysical studies of the protective dam of the valley of the river Psekups, which made it possible to clarify the boundaries of engineering-geological soil elements and determine the dynamic properties of the dam and foundation, which were used in the calculation of the barrier dam for seismic loads. It should be noted that the water level in the Krasnodar reservoir varies significantly throughout the year; its minimum value, as a rule, occurs in the autumn-winter period, and the maximum – in the spring, this significantly affects the value of seepage flow through the body of the protective dam of the Krasnodar reservoir in the valley of the river Psekups and on the position of the depression curve. The main purpose of the work is to substantiate the stability of the protective dam of the Krasnodar reservoir in the valley of the river Psekups after a long operation and due to an increase in the normative seismicity of the territory. It is established that the discrepancy of one of the first approximate methods for calculating the stability of slopes according to V. Felenius with those performed in the course of the study are within the error of the initial data obtained in the field a comparison of the calculation results using a software package using the four most recognized methods in scientific, design and construction organizations in Russia – the Cray method, the Terzaghi method, the VNIIG method, the Mozhevitinov method and the method according to SP 39.13330.2012 -was carried out. 

The article presents the results of calculated studies of the strength of the abutment structures of the floating dam of the dry dock. The calculated studies were carried out on the basis of the spatial finite-element model of abutment, in which there were simulated the enclosing walls of the pipe sheet pile, reinforced concrete abutment, soil of the base and filling. The results of stress-strain state and strength calculations have shown that the maximum displacements of the structures, stresses in the pipe sheet pile, ground anchors and reinforcement do not exceed the maximum permissible values. On the basis of the computational studies performed, the abutment structures of the floating bulkhead were substantiated. The abutment of the floating bulkhead to the dry dock structures serves to support it and transfer the pressing forces of the floating bulkhead to the ground. The enclosing abutment structures of the floating bulkhead are designed as vertical walls made of pipe sheet pile with a reinforced concrete abutment structure in the upper part. To ensure strength, a traditional solution was adopted with the anchoring of the pipe sheet pile with steel rods and ground anchors. To create a waterproof circuit, the project provides for the deepening of the pipe sheet pile into the rock base, the filling of the pipe cavity with concrete, welding of the locks with a metal plate with the filling of the cavity with polymer resin. 

Issues related to the design and hydraulic calculation of the transit part of a closed tubular water supply structure of the siphon type is considered. The operating conditions of the siphon with rectangular pipes in the transition mode are evaluated, in which the entrance section of the pipes of the culvert structure experiences increased hydrodynamic loads, often leading to certain destructions. The siphon design was modeled with two breaks along the length with a smooth inlet head and without a head. During the experiments, the absence of influence of the inlet head of the tubular HTS on the length of the free-flow section was noted. It has been established that the conditions of formation and features of the hydraulic operation of the siphon in the transient mode are largely determined by its design features. With the flooding of the inlet head, the flow of air into the pipe is hindered and a transition mode of the second type is formed with a slight fluctuation of the water level in the upper pool. The dependence of the location of the point of separation of the flow with a decrease in the passing water flow rate on its value is revealed, which made it possible to obtain a graph of the dependence of the relative length of the non-pressure end section on the square root of the Froude number. A comparison was made with the results of studies by other authors, which showed an increase in the relative length in tubular HTS of the siphon type in sections with reverse slopes at the same Froude numbers. Recommendations are given on the methodology for carrying out hydraulic calculation of tubular structures of the siphon type with minimal flow rates. 

The article is devoted to the issues of substantiation of design solutions in the field of water management and hydraulic engineering construction using simulated water management models. The problems of creating databases using various models of natural processes, including climate forecasting systems and a model of atmospheric dynamics, are touched upon. The list of tasks that are solved with the use of MIKE class models, capable on the one hand to solve the problems of modeling natural processes, on the other – to carry out simulation modeling of natural technical systems, including water management, is considered. Software packages can be used to develop rules for managing individual reservoirs and their cascades. It is noted that when creating water management systems, determining their parameters and mode of operation, it is advisable to develop simulation models for expert water management analysis. This allows you to evaluate the functionality of the systems and avoid significant errors at more detailed stages of design and operation. As an example, the water management system of the Zapadny Manych, a tributary of the Don, is given. The problems of the object and the range of tasks to be investigated are formulated. The system functions due to the regular water supply of part of the Don and Kuban rivers flow to it. The transfer resources are spent on irrigation, hydropower and demineralization of Lake Manych Gudilo, which is a wetland of the Rostov region of international importance. In the work, the system is schematized and a hydrological and water management analysis of the development of irrigated lands and hydropower potential is carried out using simulation modeling of the water balance with optimization elements. The directions of further research on the water supply system of the Zapadny Manych River basin are formulated. 

The purpose of the experiments is to study the characteristics of the flow in the pressure pipelines of irrigation systems with discrete liquid selection. The investigations have confirmed a slight increase in the head along the perforated pipeline during withdrawal of the fluid, which is explained by the transition of kinetic energy to potential energy. Theoretical studies of the fluid flow with a flow rate variable along the length of the pipeline made it possible to obtain dependences that describe the characteristics of the flow in the presence of both uniform and non-uniform installation of drains along the pipeline and pressure losses, taking into account the discreteness parameter, which takes into account the number of outlets per a unit of the length, i.e. frequency of setting. To clarify the coefficient of the flow disconnection, the studies were carried out, the results of which showed the independence of the ratio of the speeds of the main flow and the flow rate of the jet from the diameter of the outlet holes. The coefficient of disconnection of the flow is in the range of values from 0.66 to 0.87. The results of experimental studies allow us to conclude that the parameter of flow discreteness decreases with an increase in the number of drains. The value of the value of head losses in discrete withdrawal was determined by the value of head losses with uniform withdrawal of the fluid flow, taking into account the discreteness parameter. The obtained calculated values are well confirmed by the results of experimental studies. 

Based on long-term information and analytical materials of the reference and information portal «Weather and Climate», the World Meteorological Organization (WMO) and RSE «Kazhydromet» for 1940-2020 for 17meteorological stations of the Almatinsky and Zhetysussky regions located on the territory of the Balkhash-Alakol water management basin of the Republic of Kazakhstan graphs of changes in the average annual air temperature and annual precipitation and their linear trends were built using the Microsft program Exceland received a system of linear equations, allowing the creation of a bank of climate changes in order to identify regional features and trends in climate change, develop software to assess territorial differences in energy resources and the norms of water demand for agricultural land. To solve the problem of water security in the context of water scarcity with global climate change, the need to develop standard indicators for long-term forecasting and planning of activities in the field of water use within the framework of rationing the total water consumption of agricultural crops and agricultural land based on modern worldviews and the natural scientific understanding of the environmental economic mechanisms for the use of water resources. 

The water outlet structure is an important component of a reclamation pumping station. The article develops the design of a telesgraphic water outlet structure and provides an analysis of hydraulic operating conditions in non-flooded mode. The paper proposes a new type of water outlet with a distinctive feature of the presence of a telescopic mechanism that allows it to be placed in the water intake at the head of the main channel of the irrigation system and consists of two box structures connected to each other with the possibility of moving relative to each other, which allows the collection of carts in the non-flooded mode. The paper provides a detailed description of the proposed design and some preliminary, but confirming its operability and efficiency of functioning, are carried out. To perform real calculations of the telescopic water outlet, it is necessary to consider the parameters of the flooded vertically ascending jet, as well as to determine the optimal parameters of the perimeter of the telescopic water outlet. 

Purpose of research – determine the infl uence of the degree of soil salinity on the state of hardwood plantations in the green zone of Nur-Sultan city The objects of research were forest plantations growing on soils with limited forest suitability. Artifi cial plantations of silver birch Betula pendula and Siberian elm Ulmus pumila in 2006 and 2010 of the same age class were selected for the study. Depending on the state of artifi cial plantations, soil tilling was carried out on the test plots at the depth of the root formation and soil samples were used for the analysis. It was revealed that there is diversity in the type of soil salinity across all sample plots and the most common one is chloride and sulfate salinity that is found in both healthy and weakened stands of both tree species. In chloride and sulfur chloride soil salinization, the physical state of birch plantations was signifi cantly reduced. The content of the sum of toxic salts in the soil under forest plantations of the Siberian elm in healthy stands was minimal, which was gradually increasing with the deterioration of the condition of the trees. In silver birch species, approximately the same content of the total salts was observed in healthy and deteriorated plantations, the increase in toxic salts contents was observed in weakened plantations. The height and diameter of trees in healthy stands of both tree species exceeded those of trees in weakened plantations, judging by the coeffi cient of variation, tree growth was heterogeneous. It was determined that for the Siberian elm the amount of salts of 0.057% is lethal, the salt content in the amount of 0.014% does not affect the decline in the condition and growth of trees. For the forest plantations of silver birch, contradictory results have been obtained, which require additional research. 

The purpose of this work is to study the species composition and analysis of the flora of the «Nerchugansky» reserve. The Nerchugansky State Nature Reserve of regional significance was created in the Tungokochensky District of Zabaikalsky Krai, part of the Far Eastern Federal District, with the support of WWF Russia to preserve its natural heritage. This large protected area is situated in the basin of the Amur River – in the valley of the Nercha River and its most important tributary, the Nerchugan. The importance of this PA in terms of environmental safety is explained by the fact that several large placer gold mines operate in the region, which has a significant negative impact on natural systems. The article presents the data of field studies of the terrestrial ecosystem of the reserve. As a result of the collected material, a systematic register of plant flora has been compiled with the allocation of leading families. The results of the chorological analysis are presented and the features of the formation of vegetation cover in this territory are revealed. The zonal and ecological classifications of the vegetation cover are distributed. The phytosozological analysis of the flora of the reserve was carried out. A number of rare and needy plant species have been identified. The analysis of the flora of the first stage of the study showed the presence of 167 species from 112 genera belonging to 40 families, with the selection of the leading ones. Of these, 10 species belonging to 9 genera from 6 families are included in the Red Book of the Zabaikalsky (Trans-Baikal) Krai. This area is characterized by a diversity of forest communities as well as isolated relict areas of mountain steppes with high species diversity. Preservation of intact natural communities and development of mechanisms of sustainable nature management will preserve biodiversity and ecosystem services of the territory.