The purpose of the work is to assess the probabilities of the need for irrigation, taking into account the requirements of plants and soils for different agro hydrological areas of the Samara region, in which five agro hydrological areas are allocated. The issues of substantiation of irrigation taking into account both the requirements of plants and soils in the conditions of heterogeneity of the distribution of moisture reserves in the soil at the macro level (in agro hydrological areas) are considered. This allows you to choose the most favorable conditions for growing plants and preserving soil fertility, allows you to reflect the requirements of the soil biota community. Soil requirements (optimal moisture reserves for soil formation) are proposed to be defined as the most probable in specific natural and climatic conditions, which makes it possible to reflect the requirements of the soil biota community, since it is difficult to use the indicator type of soil organisms. Calculations are carried out on the example of a moisture-loving plant (cabbage) and a cereal grass mixture little demanding for water. The requirements of plants to soil moisture reserves represent the function of dependence of their productivity on moisture reserves in a layer 0... 50 cm. Soil requirements are determined using the space-time function of the distribution of moisture reserves in the conditions of natural vegetation (grass). The need for hydro-reclamation measures is determined by comparing the requirements of plants and environmental conditions. The probability of the need to irrigate a moisture-loving crop in different agro hydrological areas is 18%, for crops that are not demanding water - 12%. At the same time, soil formation conditions improve up to 60%.

The purpose of the performed research is, based on the analysis of field studies, to select a well (point) for the selection of averaged moisture in the inter-drainage space for monitoring reclamation systems, to justify the construction of drainage-humidification systems to regulate moisture in a fire-hazardous peat bog. To solve the problem, a scheme has been developed for organizing monitoring on engineering reclamation systems that provide a two-way regulation of the water regime in the root layer of the soil in the zone of unstable moisture, as well as for monitoring and ensuring fire safety of the entire peat profile. The article discusses measuring equipment for determining the dynamics of soil moisture which must be used to monitor reclamation systems. There are given the results of field studies on peat bogs of the floodplain of the Dubna River, Moscow region, namely: meteorological data and data on soil moisture. On the basis of the research carried out, a representative point of moisture sampling for monitoring of reclamation systems has been substantiated. The sampling point should be located on a typical plot with the same relief, the soil profile should be uniform with the properties and soil morphology characteristic of the entire field. Wells for sampling checks the value of the distance in %E (E is the distance between drains), in this case the measured value is close to the average value in relation to the entire section of the drainage-humidified system. For the soil conditions of the experimental site, the humidity in the selected well during the locking of the canal in the dry period of summer increased by 1.5 times reaching the fireproof one. It is noted that when supplying and maintaining a propped water level in a channel up to 85 cm deep for 5 or more hours, the humidity in the interdrains space rises to the value of the fire safety norm in the dry period.

The purpose of the research is to summarize information about management in the field of land reclamation and the sequence of its implementation, the current state of the reclamation facility Tinki-II and the possibility of introducing digital technologies in land reclamation. There are considered issues of state management in the field of land reclamation, the sequence of measures to improve land, monitoring investigations and digitalization of the management of land reclamation. In Russia 80% of the arable land are under dry conditions, and about 20% - under excess moistening. There is given formation about the current state of the land reclamation in the country and regions. The issues of state management in the field of land reclamation, the sequence of measures to improve land, monitoring studies and digitalization of the management of land reclamation are considered. The introduction of digital technologies in land reclamation will make it possible to enter the results of monitoring into the general database of the information and communication platform «Digital Land Reclamation», reading information from sensors online, and to plan and carry out restoration measures in a timely manner.

The aim of the study is to study the possibility of obtaining agricultural products from dry lands in arid climatic conditions of mountain areas, depending on natural moisture availability. The concept of types of arable land locations was introduced. The entire variety of locations of arable land in the Sanaa basin is divided into five types of locations depending on the location of a particular one or another form and relief element. The characteristics of the types of locations of the main wadi, intermountain basin, plain and other forms of relief of the Sanaa basin are given. The methodology for assessing the natural moisture availability of the types of locations of arable land of the main landforms was developed. Based on the materials of experimental field work on drain-forming sites and literary sources, the values of the runoff coefficients of the exits of indigenous rocks, loose eluvial, deluvial-proluvial and alluvial sediments of arable lands were determined and adopted for the calculation of natural moisture availability.

Identified in the process of analyzing the operation of the structure, in the conditions of its operation, allow to assess the actual reserves of the bearing capacity of the structure and take effective measures to restore the operational parameters. The main criteria influencing the choice of mathematical models of materials for structures and elements of soil dams are more consistent with the model of the equation of state connecting the components of stress and strain tensors, as well as the rate of their change, which are obtained and tested for numerical calculations and have a full set of constants for materials used in the calculations of earth dams, the choice of their structures (concrete, reinforced concrete, soils, etc.). Reliable operation of soil dams is possible only if all proper conditions are met. The causes of dam accidents and their damage must be known not only to eliminate errors at the design and construction stages, but also during their operation. In order to exclude the negative impact of operational factors on the safety of soil HTS, it is necessary not only to strictly observe the rules of technical operation and take measures to exclude the possibility of an emergency situation during technological operations at facilities, but also to have methods for predictive justification of the restoration of strength and operational indicators of structures and elements of soil dams.

During the operation of pressure hydraulic structures, there is an objective need to ensure their safety and reliability. In the case of non-stationary loads on hydraulic structures, they can be either seriously damaged or destroyed. One of the non-stationary effects can be considered a directed explosion on the body of a hydraulic structure or in the immediate vicinity of it. At significant Mach numbers, the processes of excitation of the internal degrees of freedom of molecules, ionization and dissociation of gas molecules, and their recombination occur behind the shock wave front. The course of these processes is due to the almost tenfold compression of the gas at the time of the explosion and it’s heating relative to the room temperature of the order of 10⁴ K. The use of approximate and numerical methods is a consequence of the difficulties associated with the need to solve nonlinear equations of gas dynamics, with the simultaneous use of relaxation equations and equations of chemical kinetics at the same time.

The results of experimental data of studies of reinforced concrete structures made of light high-strength concrete in a wide range of reinforcement coefficients (0.015-0.036) are presented. Experimental studies of a series of beam-type reinforced concrete structures made of light high-strength concrete were carried out according to the first and second groups of limiting states to substantiate the use of such structures in hydraulic engineering. It should be noted that the complex technical solutions for a floating bulkhead are under development for the construction of a gravity-type foundation (including an abutment in an earth dam). Recommendations on the use of the obtained results of experimental studies in hydraulic engineering building including when designing a reinforced concrete structure of a dry floating bulkhead for the construction of a gravity-type foundation made of lightweight high-strength concrete are given.

The results of the assessment and analysis of the operating modes of the power complex with the constructive and technological combination of hydraulic power plants (HPPs) with solar power plants (SFEU) in the presence of seasonal or daily regulation in the environmental hydro system are presented. The aspects of the operation of a hydroelectric power station with non-self-regulating derivation are considered in detail: when working in a load schedule with a maximum power equal to the installed one, and when the average daily power along the watercourse is approaching the provided one. It was found that in the first case, the influence of the SPEU regime on the joint work with the hydroelectric power station is to move a part of the load graph of the hydroelectric power plant with the maximum power to the base part of the schedule. In the second case, the influence of the SPEU mode consists in changing the variable part of the load graph, but the HPP, in contrast to the first case, retains its position in the load graph of the power system. The mode of operation of the hydroelectric power station becomes more uniform and at the same time, a smaller volume of the daily regulation basin (DRB) is required. For the example considered, the maximum power of the hydroelectric power station during the day increased from 50 MW to 54 MW. It has been revealed that even with the production of SPEU in 18% of the daily production of hydroelectric power plants, the volume of DRB is required approximately two times less. As a result, it is possible to increase the operating head at the hydroelectric power station and obtain the corresponding effect on power and electricity generation.

The purpose of the research is to monitor the amplitude-frequency characteristics on the example of the Chirkeyskaya HPP dam for further assessment of the state of hydraulic structures and hydroelectric units of the HPP, as well as to develop an automated system for seismometric control of hydraulic structures of the Chirkeyskaya HPP. The article presents the results of modeling and calculations of dynamic test data of the Chirkeyskaya HPP dam using the primary processing of measurement results to identify the quality of information processing by existing methods. The paper presents the results of measurements to create a mathematical model of the dam of the Chirkeyskaya HPP. Methods were used based on the study of the statistical characteristics of vibrations arising under the influence of the dynamic effects of equipment and the external environment for the experimental determination of the frequencies and modes of natural vibrations of the hydraulic structures of the Chirkeyskaya HPP. Spatial-frequency diagrams of the vibration intensity distribution in the radial direction were constructed, an algorithm was implemented to use data for both reference points when identifying natural frequencies and dam shapes, a spatial-frequency distribution diagram was constructed, averaged over two reference points, smoothed interpolated along the dam with a uniform step the conversion factor at the ridge level.

Hyperbolic curves are used in various theoretical and practical studies, including in the field of water management and environmental construction when calculating various geophysical objects with hyperbolic outlines (surfaces of coastal slopes, sliding lines of landslide massifs, directing dams, spillway surfaces of watersheds, water free fall trajectories, etc.). The exact determination of the length of the hyperbola arc is represented by a rather complex dependence based on “unbreakable” incomplete elliptic integrals, which makes it difficult to carry out analytical calculations and involves the use of tabular data with a time-consuming cross and non-linear interpolation of them, etc. Elementary dependencies are proposed to determine the length of the hyperbola arc, which give a very close approximation (up to 1%) to exact values. The obtained calculated analytical dependencies for determining the length of the hyperbola arc are recommended for practical use in theoretical and applied research in various fields of science and technology.

The article on the observations of weather stations in the south-west of the Chernozem (Black Earth) zone of Russia checks the main hypothesis about the increase in the maximum daily precipitation which is the basis for calculating the maximum water consumption when designing reservoirs of hydraulic structures on small catchments. Statistical calculations showed a clear regional trend towards an increase in the maximum daily precipitation over time. Studies have confirmed a significant asymmetry in the distribution of their values, the ratio between the coefficients of asymmetry and variation ranges from 2 to 5. It isnoted that there is currently no sufficiently accurate method for determining the coefficients of asymmetry, therefore, approaches to their expert assessment have been proposed. It isrecommended to estimate the normative values of the maximum daily precipitation for erosion calculations using empirical probability curves. Thus, in the current regulatory documents intended for the design of hydraulic structures, there are shortcomings in the methods for determining hydro meteorological characteristics which leads to a decrease in their operational reliability during the passage of dangerous rain floods. The necessity of appropriate updating of the existing regulatory documents is substantiated.

The article is devoted to measures for the purification of water and air medium from polychlorinated biphenyl wastes by the method of UV radiation and NiO2 nanoparticles, on PCBs (polychlorinated biphenyl) constituting groundwater in PCB waste disposal areas, the possibility of neutralizing PCBs in the atmosphere in industrialized areas. A method for the degradation of polychlorinated biphenyl contained in waste and industrial waters, as well as in atmospheric air, has been proposed. Air purification is carried out with ultraviolet and microwave radiation, and ultraviolet radiation and TiO2 nanoparticles are used for water purification. Based on the analysis performed, the problem of optimizing the purification of groundwater and atmospheric air contaminated with polychlorinated biphenyls has been formulated and solved. An expression is proposed for the dependence of the cleaning time on the distance to the place of initial environmental pollution.

The paper presents an analysis of the repeatability and changes in the area of zapripayny polynyas of the Kara Sea in winter. Comparison of areas and repeatability of polynya during the period from 2010 to 2019 and for many years a number of observations from 1980 to 2009 are given. A number of observations of the regime and dynamics of the polynya for the period from 1980 to 2019 were continued. Changes in the regime of zapripayny polynyas, as well as changes in the ice content of the southwestern part of the Kara Sea associated with an increase in the duration of freezing as well as with early breaking of the pripaj and rapid melting of ice were revealed. To obtain data on the areas and repeatability of the polynya, regional maps of ice formations of AANII were used in the format SIGRID-3: A VECTOR ARCHIVE FORMAT FOR SEA ICE CHARTS», in the geographic information system Arc GIS, followed by the creation of an archive of spatial data including information on the areas of stationary zapripayny polynyas. The work also included the use of NOAA-19 satellite images, for working with which the ENVI program was used - a program for visualizing and processing data of the remote sensing of the Earth.

As a result of the increasing anthropogenic and technogenic impact on forest ecosystems, ecological monitoring over the changing indicators of growth and condition of trees has acquired a particular importance. Along with many traditional observation methods based on the analysis of water, soil and air samples, methods of bioindication of the assimilation apparatus have recently been used, which show the level of changes in the morphological characteristics of trees depending on the external negative impact of the environment. The purpose of the research is to determine the state of silver birch forest cultures in the green zone of a city of Nur-Sultan using bioindication methods. The object of research was the assimilation apparatus of 12-year-old silver birch forest cultures which at the age of 7 were transplanted from the strips to the spaces between strips. The morphological features and fluctuating asymmetry of the leaves were studied. The crops of silver birch were classified as weakened plantations with a coefficient of relative viability of 54.2-73.0%. In 2019, the average level of deviation from the norm corresponded to the crops transplanted at a low elevation and non-transplanted at a high elevation, a slight deviation from the norm was observed in trees transplanted at a higher elevation. In 2020, condition of silver birch plantings decreased to the 4th point of the asymmetry index. The deterioration of the condition of trees is associated with an increasing anthropogenic load on plantations and environmental pollution. Since the pressure of these negative factors on the environment will not decrease, but will only exponentially rise, it is proposed to start taking measures to increase the sustainability of plantings (thinning, use of fertilizers, and addition of growth stimulants, etc.).

The scientific research on growing English oak on eroded soils was carried out in order to prevent erosion processes. The object of the research was a land plot on washed-out gray soils of the network and hydrographic funds. Oak crops are laid by row-well sowing of acorns of 3-5 pieces or more in one planting place. As a result of many years of research, it was revealed that during the growth period, the root system of the oak binds the washed-out slope soils well. The resulting forest litter improves the structure of the soil and increases its moisture capacity to 322% of the dry matter. The forest suitability of soils on eroded slope lands allows you to grow protective plantings from oak culture. At the age of 50, oak stands with the number of trees of 1730 pcs./ha on eroded soils have a reserve of 160 cubic meters/ha with an average height of 12.5 m and an average diameter of 13.6 cm. The average increase per 1 ha is 3.20 cubic meters/ha. Oak stands on the hydrographic network have a class III bonus. The growth of oak is noticeably improved in the presence of an admixture of other hardwoods, especially linden and undergrowth of hazel, mountain ash, birch bark, yellow acacia and other shrubs. Studies have shown that oak crops can be successfully grown on washed-out slope soils which reliably protect the soil from water erosion.

The relevance and significance of the problem of automated forest inventory is dictated by regulatory documents defining the main directions and principles of digitalization of the country’s economic sectors, including the forest sector. The article is devoted to the problem of automated inventory of forests and digitalization of wood resources by technical means of ground-based taxation of stands, as well as remote aerial photography methods, analytical decoding of the forest canopy and determination of the complex of taxation indicators through the use of information and reference systems of multidimensional forest taxation standards. To construct an orthophotoplane and obtain a digital vegetation model, aerial photography works that meet the requirements of the photogrammetric method and the method of air-laser scanning (ALS) are described. The requirements for the parameters of aerial photography using the photogrammetric method, as well as for the parameters in the BOS, are set out. Variants of the technology of inventory of stands are proposed, indicating the appropriate tools for obtaining remote sensing data of the Earth. An assessment of the reliability of contour decoding of the species composition of stands with different spatial resolution of remote sensing data is given. The accuracy of digital vegetation models with different spatial resolution of data, the possibility of evaluating morphometric and volumetric indicators of tree crowns, as well as the resulting indicators of canopy closeness as a result of automation are indicated. An important element of the automated digitalization of wood resources is the allocation and taxation of cutting areas, the assessment of the commodity-monetary potential of stands allocated for logging.