This paper presents the results of calculations of areal trends of total evaporation ETa fluxes for the growing periods of 2003-2017 in the territory of the Marksovsky district of the Saratov region. Raster layers formed for the territory with a 500 m resolution of the Eta8 (Eta 8-day averaging) for each year of the investigated time interval were obtained from tiles sets h20v03 of the product MOD16A2 for the period from May 25 to September 2 of the corresponding year. As a result, the 19830 time series of total evaporation fluxes for the ETaw growing seasons of the 15-year study period were drawn up for the Marksovsky district. The obtained time series of geodata of the actual evapotranspiration for the growing season ETaw for each of the 15 studied years were used for the spatial analysis of ETaw trends. For the analysis, the method of nonparametric Mann-Kendal statistics was used. It revealed the presence of 2 half-periods with diametrically opposite trends in the dominant part of time series. The first half-period found out negative values (downward) trends and falls on 2003-2010, the second half-period showed positive (upward) trends for 2010-2017. The presented results of the spatial distribution of both trends indicate the presence of an influence on ETaw both distance from the bank of R. Volga and anthropogenic factors. Hypotheses for additional analysis are proposed. For the visual deciphering of the places of abnormal values of trends velocities of the both half-periods there were used space photos of high resolution. As a result it was marked that the location of these anomalies corresponded to the location of pivot sprinklers in the territory of the Privolzhskoj irrigation system.

The research subject reflects one of the special conditions for the construction of reclamation systems on peatlands - this is a significant change in many of their parameters, including filtration indicators of the peat deposit - due to precipitation and compaction of peat in the process during its drainage. This research work is of a scientific and methodological nature and represents the development of a new calculation method. The ultimate aim of the research is to develop a calculation method that improves the accuracy and reliability of the existing methods for assessing the changing water-physical properties of peat due to its drainage - due to the greatest coverage and consideration of specific conditions and design factors. The introductory part describes both the current state of the issue and the relevance of the existing problem. The main part of the content contains the structure, mathematical basis and calculation formulas of the proposed method of calculation - for predicting the reduction of filtration coefficients and water loss of drained peat. A specific example of the calculation of the results of the practical use of the developed methodology is considered and given. The final part provides an analysis of the research results, the main conclusions and recommendations for the practical use of this technique.

Gradients of salts concentrations of the soil solution, rinsing water pressures, filtration coefficients determine the flow intensity of the salt solutions in the aeration zone. There are known a lot of software for calculating the motion of salt solutions in the porous medium. To assess the accuracy of calculations of the salts movement in the soil, the data of gradient measurements are used. The implementation of the known methods of physical modeling on the soil monoliths mounted according to Astapov, lysimetric installations, in experimental leaching of saline soils in the field requires significant material investments, labor and time. Minimum material and labor costs are required for the assembly and use of the proposed design of the installation for physical modeling of saline soil washing. A working prototype of the installation has been developed. It includes piezometers, a case, units of piezometers connection, sampling of soil moisture combined with soil electrodes, equalizing drain, rotating part of the case. Piezometers, drains and connecting hoses, soil moisture sampling unit. The installation case is assembled of separate branch pipes equipped with necks and sealing rings. Filtration investigations and gradient measurements of the salts movement are carried out on the installation. The tests of the installation prototype were fulfilled in the field on the sand pit reclamation map located in the floodplain of the Gzhelka and Moskva rivers of the Ramensk region of the Moscow area. The profile filtration coefficients measured at the installation - 2.33± 0.031 m / day and in the field conditions - 2.36±0.041 m / day do not differ significantly.

The peculiarity of special-purpose hydraulic engineering facilities significantly increases the importance of the wrong choice of materials associated with an underestimation of the existing loads, operating conditions and aging (wear) processes as a result of interaction with accumulation and storage of products. The intensity of the degradation process is connected with the action of force factors, physical fields, chemicals, living organisms, etc. Therefore, the most important factor determining the durability of an object is the rate of degradation of its structures. In addition to the analytical and numerical approaches, concrete degradation is also considered from the point of view of the stages of its decomposition. The weakest, from the point of view of corrosion, component of concrete is cement stone which determines the intensity of concrete destruction, depending on the mechanism of interaction with an aggressive environment. The constant impact of an aggressive environment on concrete components determines the development of corrosion processes in its very thickness. In the course of corrosion of the concrete material, various mechanisms for the transfer of aggressive substances appear which indicates that during the degradation of building structures made of concrete or reinforced concrete, a complex set of transformations occurs leading to a change in the properties of concrete in structures.

Due to the increasing demand of energy consumers for high-quality, energy-intensive sources of electricity generation with a high EROI index, the implementation of tidal power plant projects is becoming increasingly attractive. At the moment, there are more than 100 stations in the world where the technical realization of TPP projects is possible. Until recently, cheap and seemingly limitless fossil energy allowed most of society to ignore the importance of the contribution of alternative sources of energy generation such as PES, but now their demand is increasing. The implementation of TPP construction projects contributes to the sustainable development of coastal towns and makes a significant contribution to the energy balance of the system. The energy potential of tidal energy is quite large and comparable to the energy potential of the rivers of the Globe. Compared to river energy, the energy of tides and wind waves is low-potential, and therefore in most cases more expensive. It is worth noting that the advantage of tidal energy is environmental cleanliness, reducing the likelihood of flooding of adjacent territories and the absence of changes in the coastal landscape.

The issues of solving modern problems related to meeting the energy needs of environmental hydraulic engineering are considered. The problem of improving the methodological basis for choosing the optimal arrangement of elements of photovoltaic devices (SPEU) on the blocks of the dam building of hydroelectric power plants (HPP) of 4 main types is formulated. The graphical dependences of the estimation of the power ratio of the combined SPEU and HPP on the diameter of the turbine wheel are analyzed. As a result of the analysis of the influence of the location of the transformer on the possibility of placing the SPEU on the buildings of the hydroelectric power station, it was revealed that in order to increase the adaptability of the revitalized even large hydro system with a separate building of the hydroelectric power station, it is preferable to place power transformers from the downstream side. It is noted that according to the results of the schematic study for the medium-pressure hydroelectric complex Lagdo in the north of Cameroon, the placement of solar cells will provide an additional 6.95% of the capacity of the operating hydroelectric power station.

Ensuring the operational reliability of hydraulic structures is an important task at the stage of the life cycle of the structure. The main reasons of destructions of hydraulic structures in the course of research were identified as errors in the design of such structures and their construction, or the absence of operating organizations and, as a result, the lack of proper maintenance for such structures. Such errors inevitably lead to the creation of defects in the body of hydraulic structures with the subsequent development of deformations and destruction of hydraulic structures because of a violation of the filtration strength. In this regard, standard methods for assessing operational reliability appear to be cumbersome and inefficient in the conditions of a short time allotted for assessing the degree of damage to the structure, obtaining reliable results on the current level of operational condition and developing a set of measures for their restoration. In this connection, there is a need to develop probabilistic model there re is a need to develop probabilistic methods for the operational condition of hydraulic facilities, taking into account the physical and mechanical properties of the materials, the degree of damage and the characteristics of the operation.

The article indicates that pipes with a liquid flowing through them are one of the most common elements in various fields of industry. Pipelines in oil and gas and a number of other industries have valves and connections that can be modeled as concentrated masses. It is very important to consider their impact when investigating the dynamic behavior of pipelines. Developing fluctuations are the subject of research by many scientists. The article investigates a pipe with a static scheme of a beam freely lying on the supports with concentrated dampers. The stability of the system consisting of a pipe with concentrated dampers and a liquid flowing through it is investigated. The spectral Galerkin method is used to determine the critical fluid velocity. On the basis of theoretical studies, it has been established that a pipeline system with dampers loses its stability at 1.26 times lower fluid flow rate (V_av = 122. 67, m/s) than in the case without dampers (V_av = 155 m/s).

Calculations of the main parameters of the Proletarsky main canal for a polygonal section during its reconstruction for various options are presented. A method for hydraulic calculation of the Proletarsky main canal has been carried out. The developed method of the hydraulic calculation is based on the determination of the coefficient of reduction of the polygonal shape of the section to the trapezoidal one according to the formula of A.A. Uginchus. Then the cross-sectional area of each element is found after reduction to a trapezoidal section, the wetted perimeters, hydraulic radius and Shezi coefficient of each section element are calculated. For the earthen channel of the canal, the obtained hydraulic characteristics closely matched the design data for the flow rate and average current velocity. The earthen channel of the canal with an ice cover has a significant decrease in hydraulic parameters from the design section, both in terms of flow rate up to 36.0 m³/s (or by 33%) and in terms of the average flow velocity up to 0.410 m/s. The widened asymmetrical earthen channel is characterized by an increased discharge up to 57.47 m³/s, an effective cross-section of 101 m² and a wetted perimeter of 42.0 m in comparison with the design section. For the channel of the canal section with a protective strengthening made of a rock fill and gravel-pebble coating, reduced characteristics were obtained both in terms of flow rates and average flow rates which is due to their high value of roughness coefficients. At the same time, it was found that a decrease in the roughness coefficients of protective coatings during operation due to the colmatage of alluviums particles will lead to an increase in water consumption in the canal. However, the process of alluviums colmatage of the protective layer of stone material will be slow, for 10 years or more.

The article concentrates on the water management situation of two transboundary basins of different scales taking into consideration the individual characteristics of the system of water resources using. The water management and environmental problems of the Euphrates (Turkey-Syria) and Karkotis (Cyprus) rivers are analyzed and their water management potential is estimated based on their generalized hydrological parameters. The chosen river basins have catchment areas (440 thousand km² and 90 km²) that differ by several orders of magnitude, but the essence of the problems remains regardless of the scale and requires an equally detailed analysis and an individual methodological approach. The historically tense Mesopotamian region in terms of water resources is considered on the example of the Euphrates River. The existing and projected hydraulic units and water management systems in the Euphrates basin on the territory of Turkey and Syria predetermine a potential conflict of interests. Without focusing on the political aspects of the problem, the current situation and the real water potential on the border of Turkey and Syria are analyzed. The Karkotis River (another name for Klarios), originates in the north-east of the Troodos mountain range and flows into the Morphou gulf, Mediterranean Sea. The project «Kariotis» (the name of the project differs a little from the river name) was created in the 90s of the last century by a group of Soviet specialists on the terms of a contract. The project was not implemented for political reasons, but it is of interest in terms of the project tasks to be solved and cross-border features. The most important areas of the scientific research related to the hydrological and water management justification of project solutions for water resources management are formulated. This is a primary condition for effective joint water use in transboundary basins.

The article considers the issues and prospects of water use in the Kabul River basin (Afghanistan) taking into account the analysis of the current water management situation and taking into account the forecasts of the economic development compiled on the basis of the demographic data. The general scheme of water use, organization of water supply, provision of the population with water and sanitary drainage structures is presented. The analysis of the water resources use and structure of water management of Afghanistan in the Kabul river basin showed a wide use of groundwater to supply urban and rural population, livestock and irrigation while surface waters of rivers are hardly used by the population and sectors of the economy. The fulfilled analysis of the water use structure in the territory of the Kabul river basin showed that: 55% of the demand for water is provided by underground water, 23% - by surface river runoff, 12% - by glacial water and 10% - by rain runoff. Comprehensive calculations based on the compilation of water management balances were carried out. Risks of water shortages and river pollution for the 2020 year and for the future until 2035 were checked for the estimated years on the provision of river flow of the Kabul River by 74% and 95%. A set of water management, water protection and management measures has been developed and recommended to prevent and eliminate the identified possible negative trends in water use. The analysis of the quality of water resources in Afghanistan was carried out which showed that the situation with water resources in the country has been noticeably improving in recent years.

The research subject under consideration reflects the aspects of the underground water kinetics - ground water formed in the upper non-pressure aquifers. The material of the article is of a scientific and methodological nature, it characterizes the essence of the new developed calculation method - to determine the size of the capacity of the first aquifer (the depth of its bottom - the depth of the confining layer. The article reveals the essence of the problem and the ways of its solution - by improving the existing calculation method based on the processing the materials of long-term observations over the regime of ground water depth. Special attention is paid to the presentation of the mathematical basis for the execution of the calculation; its structure and order of execution are given. At the beginning of the substantial part there is given the current state of the matter, the relevance of the theme and its newness that is to use short-term observation over the regime of the groundwater depth. In the final part there is given the analysis of the results of preliminary practical approbation of computational techniques in the Bryansk area -on the specific materials of real long-term observations over the regime of the depth of groundwater. In conclusion, the analysis of the research results and recommendations on the use of the developed methodology in the practice of water management and hydraulic engineering construction is given.

The water resources of Kyrgyzstan, the uneven distribution of water resources across the territory are considered. A map of the distribution of the population, water resources and water supply by regions was prepared which is based on the comparative analysis of several indicators of the administrative-territorial units of the country. The distribution of water resources was presented in the following indicators - water supply across the territory of administrative-territorial units and water supply per capita per year. The quantitative indicators of water intake, the directions of the use of the country’s water resources by regions, such as irrigated agriculture, production needs and communal drinking water supply, are described in detail. The sources of drinking water and the amount of water losses are indicated, the main reasons for high water losses are determined. The differences between the northern and southern regions of the country in terms of water supply, the ratio of the north and south of the country in terms of water use have been determined. Among the regions of Kyrgyzstan, a more detailed description of the use of water resources was given for the Chui region which makes the greatest contribution to the country’s economy.

The article presents a stochastic model of runoff with a five-day discreteness within the water management years. The analysis performed regarding the main statistical characteristics of the inflow to the Krasnodar reservoir has allowed the conclusion that this model, based on a simple Markov chain, satisfies the balance accuracy of hydrological calculations for operational regulation of the runoff. The performed verification calculations have shown that the proposed method for obtaining medium-term runoff forecasts for 5 days, based on the developed stochastic runoff model, is satisfactory to the criteria of efficiency and accuracy of hydrological forecasting methods used in Russia. The specific example has shown that a stochastic runoff model can be useful to decision-makers regarding the operational management of a reservoir in real time.

The article considers methodical approaches to the analysis of the current state of the management problem of water economic systems under non-stationarity of multi-year fluctuations of surface water resources. Application of the simulation modeling method for solving water management problems is substantiated. The main provisions of the analysis of initial hydrological information to control the operation regime of the Volga-Kama cascade of hydraulic units are given. Methodical provisions for the analysis of the operation regime of complex water management systems with a cascade of hydraulic units with reservoirs in its structure are formed. The operation modes of the Volga-Kama cascade of hydraulic units under the conditions of different water content of the Volga River are analyzed. The considered methodic provisions are illustrated by the examples of simulated modeling of the Volga-Kama cascade operational regime under average water content conditions. The structure of modern water management systems and their functioning is presented as an open multicomponent dynamic system. The ultimate goal of the analysis technique of the water management system with the knowledge of the regularities of hydrological system formation is development of formalized mathematical models of this system functioning and investigation of many alternative variants under different natural-economic conditions.