Irrigation of land over time leads to the development of such negative processes as salinization and waterlogging of land, a decrease in soil fertility, a change in the chemical composition of groundwater, soil erosion. The reclamation state of irrigated land is a complex qualitative indicator that assesses the impact of natural and technological factors and characterizes the state of the system «Soils - Soils of the aeration zone - Groundwater». The categories of land reclamation state adopted in Russia and a number of post-Soviet countries determine their suitability for agricultural use and the focus of measures to preserve potential soil fertility. On the example of the Altai Territory, an analysis of the dynamics of a number of indicators characterizing the reclamation state of land is carried out: the depth of the groundwater level; mineralization of groundwater; mineralization of irrigation water; the degree of soil salinization in the root layer; the degree of salinity of the soil, as well as the possible causes of the development of negative processes. Using the methods of mathematical statistics, the rates of development of processes on irrigated lands and trends in increasing / decreasing the area of irrigated agricultural land, on which changes in each of these indicators are recorded, are estimated

The subject of research is the development of a method for calculating the total water consumption of vegetable crops, aimed at increasing the accuracy of its determination, in the conditions of the Non-Chernozem zone of Russia, and saving water resources. The object of these studies are sod-podzolic soils and soil moisture, vegetable crops. Scientific research was carried out in lysimeters, on experimental plots and in the laboratory, in years with different meteorological conditions. Physical modeling, the method of water balance, the theory of groundwater flow and mathematical statistics were used in the processing and analysis of scientific research. Experiments in lysimeters in plots in 2010... 2015, served as the basis for the development of a formula for determining the total water consumption of vegetable crops. At the same time, empirical coefficients for this equation were obtained, characterizing the type of soils and the climatic zone. Biological coefficients for stem beets, potatoes, table carrots have been established, as well as coefficients depending on soil moisture when it decreases below the optimal values for these crops. A decrease in the total water consumption of vegetable crops at the beginning and end of the growing season was determined. A graph of the dependence of the actual total water consumption of the crops under consideration Ef (data from experimental plots) with the calculated Ep according to the formula is given, showing a close relationship between the considering features. A formula has been developed that we recommend using to determine the water consumption of vegetable crops in the Non-Chernozem zone of Russia.

The purpose of the research is to determine the toxicity of domestic wastewater after mechanical and biological treatment and the potential possibility of their use for irrigation. The toxicity of treated wastewater from wastewater treatment plants (Kadamovskiye WWTP) in Novocherkassk by the method of biotesting on different test objects - infusoria (Paramecium caudatum), green protococcal algae chlorella (Chlorella vulgaris Beijer), white mustard seeds (Sinapis alba) is evaluated. Laboratory studies were carried out in the accredited ecological and analytical laboratory of the Federal State Budgetary Institution «RosNIIPM». The results of biotesting at the chlorella test object showed that the treated household wastewater does not have a toxic impact. Biotesting at the infusoria test object determined only the toxic impact of wastewater after biological treatment. The length of the white mustard seed roots in wastewater after mechanical and biological treatment is above 120%, compared with the control, which proves the stimulant effect of these waters. So, according to the results of biotesting domestic wastewater after mechanical treatment from the Kadamovskiye WWTP in Novocherkassk can be potentially used for irrigation. According to the research results, wastewater after biological treatment «has a toxic impact», which causes their use for irrigation only after additional treatment.

The purpose of experimental studies is to determine the propensity to spontaneous combustion and forced ignition from heated bodies of peat samples at different densities. This article discusses the problems of the occurrence of natural fires on reclaimed developed peatlands introduced into agricultural circulation under the black culture of agriculture, which has become widespread in Russia, the causes are identified and ways to solve this problem are proposed based on experimental studies. It has been established that the possibility of the occurrence of processes of spontaneous combustion and forced ignition of peat soils is mainly influenced by the density of the upper peat layer, due to the influence on thermophysical properties, such as thermal conductivity coefficient, thermal diffusivity coefficient, volumetric heat capacity coefficient. As measures to change the thermophysical properties of the surface of worked-out peatlands, special treatments are proposed using the prevention of pyrogenic destruction of agricultural land.

The purpose of the research is to study the chemical composition of treated domestic wastewater and to assess the potential capability of their use for irrigation purposes. The object of the study is domestic wastewater from the «Kadamovskie» WWTP, Novocherkassk, after mechanical and biological treatment. Research methods included the determination of the wastewater suitability according to the following indicators: the concentration of toxic salts, the ratio of cations, the content of the main biogenic elements (NPK), the irrigation coefficient according to Stebler, the ion exchange coefficient by I.N. Antipov-Karataev and G.M. Kader, sodium-adsorption ratio (SAR), risk of magnesium alkalinization (Sabolch and Darab). For studying the chemical composition of treated domestic wastewater, wastewater samples were taken from the «Kadamovskie» WWTP in Novocherkassk and their chemical composition was determined in an accredited environmental analytical laboratory of the Federal State Budget Scientific Institution RosNIIPM. Based on laboratory results, wastewater is classified as low-mineralized (1.0...3.0 g/dm³), according to the degree of mineralization. Wastewater (after mechanical and biological treatment) belongs to class III and is characterized as satisfactory. In accordance with the soil-reclamation classification, its suitability for irrigation is limited due to the possibility of chloride salinization processes development. According to calculations based on irrigation coefficients, ion exchange coefficients and sodium adsorption ratio, treated domestic wastewater is suitable for irrigation and it doesn’t cause soil salinity hazard (soil alkalization). Thus, it is recommended to consider treated domestic wastewater from the «Kadamovskie» WWTP in Novocherkassk as an alternative source of irrigation water.

In assessing the hydrodynamic parameters of concrete mixtures placed in monolithic channel linings, the most important point is the development of mathematical models that describe the processes of concrete mixture slippage, taking into account the dynamics of speed reduction and increase in the viscosity of the concrete mixture over time. The main regularities of the hydrodynamic multilayer shear flow of a concrete mixture on the surface of a flat channel slope, where a multilayer plane-parallel viscous flow moves under the action of gravity, are investigated. The boundary value problem of a two-layer flow of a concrete mixture is solved, a system of two layers of viscous incompressible liquids is considered with the properties of each, respectively, the thickness of the bottom and upper layers, taking into account the sliding velocity of particles of a viscous liquid located one above the other. The obtained analytical solution of the problem in the stationary regime of a two-layer shear flow of two different immiscible viscous fluids with different properties makes it possible to formulate the main laws of such flows and describe the processes of sliding of a multilayer concrete mixture, taking into account the dynamics of speed reduction and increase in the viscosity of the concrete mixture over time. A mathematical model has been developed where the dynamic and kinematic structures of a multilayer shear flow in both viscous layers are presented separately.

The article presents the results of full-scale and computational studies of reinforced concrete structures of the shield wall of the PSPP building and the floating bulkhead of the dry dock, which are important structures, on the condition of which the construction and operation of the pumped-storage power plant and the dry dock depend. Based on the survey data, the nature of crack formation in the shield wall of the PSPP building and in the front wall of the floating bulkhead (facing towards the dry dock) was established. The acting loads and causes of crack formation were determined. The actual stresses in the armature were determined by the «valve unloading» method. Fines were cut down in concrete, the studied rod armature was bared, on which deformometers were installed and zero readings were taken. Calculation studies of the VAT of reinforced concrete structures of the shield wall of the PSPP building and the dry dock floating dam were carried out on the basis of spatial finite element models, including the structure and the base. The measures to reinforce the shield wall of the PSPP building with carbon fabrics were developed and practically implemented; the measures to strengthen the walls of the floating bulkhead were proposed.

The issues of determining the possibility of involving additional areas of irrigated limans in the territory of Maloderbetovsky district, the Republic of Kalmykia are considered. It has been established that in the territory of this region there is no flooding of estuaries due to the natural flow of melt water. Here, only estuaries developed for irrigation are used, the water supply of which is carried out at the expense of the waters of the Volga River through the operation, in particular, of the main canal P1. Currently flooding half of the areas of estuaries. The irrigation and drainage system is not capable of supplying the amount of irrigation water necessary for the water supply of all areas of estuaries. This is due to the low water flow in the R-1 canal, as well as significant water losses during transportation, amounting to about 35%. In order to eliminate the reasons for the low productivity of the HMS, it is necessary to carry out its reconstruction. Under the condition of a complete reconstruction of the system and an increase in the amount of water supplied to the P1 canal, water supply to all estuaries of the region in calendar terms convenient for irrigation becomes possible. The commissioning of additional areas of estuary irrigation will guarantee the production of 7820 tons of estuary hay and increase the provision of the district with roughage due to estuary irrigation from 30 to 50%.

Lightweight high-strength concrete structures are currently spreading, primarily in civil engineering and bridge construction. High-strength lightweight aggregate concrete has advantages over heavyweight concrete when used in structures that must have high strength and buoyancy due to lower density and high enough strength. In this regard, it seems appropriate to use lightweight high-strength concrete in hydraulic engineering construction in offshore oil platforms and dry dock gate. In the presented work, computational studies of the stress-strain state of reinforced concrete beam structures made of light high-strength concrete have been carried out. To model the behavior of reinforced concrete beams made of lightweight high-strength concrete, spatial finite-element models have been developed. Researches were performed in the software «ANSYS». The developed models are verified by data of full-scale tests of beams with two reinforcement coefficients: 0.036 and 0.015. The performed studies allowed making a conclusion about the difference in behavior and destruction of beams at two reinforcement coefficients.

The purpose of the study is to assess the conditions forensuring the protection of fish from entering water intakes when using water intake buckets. The article analyzes the possibilities of protecting fish in conditions of use of water intake buckets, which, depending on the hydrological characteristics of the water source, taking into account changes in water levels and flow rates, as well as water protection requirements and sanitary and epidemiological conditions, provide the required conditions for water supply. The possibilities of ensuring the protection of fish when using water intake buckets are considered on the example of three designs from different water sources, of which only in one condition the protection of fish can be assessed as satisfactory. At the same time, the need for additional implementation of measures to remove fish from the bucket is a determining condition for the success of their conservation. However, this presents the greatest difficulty, which is currently not solved in the layout of bucket water intakes, including foreign practice. As possible fish protection devices for the conditions of water intake buckets, the designs are considered which use the effect of hydraulic flushing and diversion, in particular filtering, louvering, etc. Based on the results of the analysis of hydraulic conditions in the bucket, a scheme for the formation of a fish diverting stream with subsequent movement along the fish drainage tract beyond the influence of the water intake bucket is considered.

The technology of local monitoring and data analysis of control and management of water management and reclamation facilities is extremely necessary in dispatching systems and decision-making on energy and water conservation. The collection, formation and pre-processing, storage and protection of up-to-date data obtained in real time will allow for operational decision-making on the status and management of a controlled water facility. The solution to this problem is possible with the use of IT technology, Blockchain technology, which is an immutable sequential chain of records. The developed algorithm makes it possible to classify the received data on the state of a water management facility, split testing of data, forecasting and decision-making on water conservation. The algorithm is implemented by a decision-making function, which is carried out by a certain functional dependence of changes in the controlled parameters at the current time. The comparison of the obtained function with the type of function determined at the previous stage of measuring the parameters of the controlled object allows us to distinguish between these functions, compare them with normative data and adjust the function and make a decision. With the corrected form of the function is determined as relevant, is recorded in memory and is subject to execution.

The paper analyzes the global trend towards increasing the intensity of large-scale accidents of industrial waste accumulators of mining and processing and mining enterprises of various countries. According to the actual (2021, 2022) ground and aerovisual surveys of hydraulic structures (HTS) of the tailings of the Tyrnyauz Mining and Processing Plant (TMPP), an assessment of the risks of catastrophic emergencies is being carried out. Separately, the objects of the HTS complex of the TMPP tailings dam are considered, the condition of which, to date, causes the greatest concern, information is provided on the dynamics of changes in their parameters. The purpose of this study, in addition to determining the current, current situation on individual elements of the tailings hydrotechnical system complex, is to develop the main directions for taking measures to improve the current situation. Based on the analysis of the obtained results, the necessary recommendations are given.

The article is dedicated to PC modeling of the maximum water runoff of the Kuban rivers flowing to the Krasnodar reservoir after the storm rains. A mathematical model of the «precipitation-runoff» type - DWAT was used. This model is recommended by the World Meteorological Organization for use on rivers with flash floods, based on river survey digital elevation models and storm rain forecasts. A possibility of using proposed approach, the estimated possibility of using DWAT for short-term forecasting of flood inflow to the Krasnodar reservoir based on storm precipitation at predictor meteorological stations, which is tentatively assessed based on the analysis of the dependence of the main elements of floods on the storm rain characteristics. In addition to the digital relief model, the model uses georeferenced layers of data on vegetation, land use types and soils of the catchment area. In general, the article shows the process of entering and processing data into the model. The obtained final simulation results, expressed by the forecast hydrograph, are compared with the observed true values. The forecasted flood graphs correspond sufficiently to the observed ones and in general the maximum water discharges of the forecasted floods obtained using the model under study for previous precipitation are for the most part slightly higher than the observed ones, which is partly explained by the spatial data due to map resolution used. The use of more detailed source data and map resolution may improve the final result.

The purpose of the work is to develop a generalizing model of«thermal islands». The results of model studies of the dynamics of the occurrence of thermal islands in urban areas are presented. On the basis of known regression partial models linking population density with the surface temperature and the fractal size of the urban structure, as well as with the distance from the center of the area under consideration, taking into account the model of time dependence of fractal dimension, general equations showing the relationship of these indicators of the urban zone in dynamics are synthesized. Generalized equations of the temporal dynamics of the appearance of the effect of «thermal islands» in cities are obtained, taking into account the fractal dimension of urbanized zones.

This paper presents the results of studies of the processes of intense planned deformation of the channels, which are formed as a result of erosion and collapse of the banks by the flow. The substantiation of forecasting the channel-forming activity of the flow and its management is given. A generalization is given of the methods of combating the intensive collapse of river banks, the organization and technology of construction with obtaining reliability, economic efficiency and environmental cleanliness. To carry out channel straightening work on rivers flowing in arid areas, it is possible to use the design of a cut, which should have the smallest approach angle of the dynamic axis of the main flow, the greatest drop in the marks of the beginning and end of the cut, its short and straight route and the minimum amount of excavation. When assessing the effect of planned deformation on the stability of the channel, a formula is presented for calculating the depth of erosion, dimensionless criteria that determine the possibility of formation of erosion for various situations, which made it possible to select the types and designs of bank protection structures.