Scientific Journal of KubSAU

Low level of water accounting and poor control in water distribution in the irrigation system are the main negative factors of industrial influence on irrigated natural complexes. Complex ecosystem way to control water resources involves qualitative improvement and optimization of all parts and elements of irrigation system, from the headwater pool, main channels to local water distribution channels. In this regard, when engineering, constructing, using some new and reconstructed old irrigated systems, the most important problems are the optimization of water use from natural water resources, development and use of highly efficient water-saving and energy-saving technologies of water distribution and water use in the irrigation system. The problem of economical and efficient consumption of water resources on the studied water complex cannot be solved successfully without any related consideration of water accounting and water consumption questions based on system principles. System principles are supposed to collect, analyze and use the information, with the help of complex technical means, which are used for water measurement in conditions of water charges, and for the purpose to control the technological processes of water supply and water drainage, when the needs of water users are satisfied and the environment get less damage. In the work, we study the mathematical calculation of the unsteady water line in the Krasnodar suburban channel for water measurement. The imitated research of hydraulic processes were carried out on the mathematical model of water measurement, based on the characteristic methods, with the use of analytical solution of ordinary differential equations of the initial characteristics. The use of the considered method of water measurement in irrigation channels with the use of analytical solution of ordinary differential equations of initial characteristics will allow to optimize the processes of water measurement and to minimize idle and non-technological discharges of water from the system

The purpose of the article is to develop methods for hydraulic design of extreme discharges and water depths in critical gage lines of waterways diverting water from spillways for the accepted law to regulate linearly distributed releases of stored water discharges. The task of control for linearly distributed releases of stored water discharges is based on hydraulic design for the process of propagation and transformation of long waves described with Saint Venant equations. These equations are nonlinear and have no accurate solution in general case. To get approximate solutions they are linearized. It is established that the task of integration for these equations supposes to get their preliminary solution in the form of complete integral. Applying the complete integral theory we get analytical solution that describe the process of transformation for one direction waves moving in infinitely long prism canal of semi-bounded extent with initial uniform regime of water flow. An example of changes in both water discharge and flow depths in two fixed downstream gage lines of hydraulic works at the distance of 5000 and 10000 m from the initial gage line is presented. Hydraulic design was carried out according to the derived analytical formulas accepted as an example classical method of characteristics that is considered as analogous. Comparison of the design results on two methods allowed to determine the maximum relative error that does not exceeds 3,5 % for the design discharges and water depths. Introduction of the developed method for hydraulic design of linearly distributed releases of discharges in waterways diverting water from spillways will make it possible to optimize idle and non-technological stored water discharges

The article considers the mathematical task of calculating the transient flow of water in the regulation of concentrated releases of water discharges on stream flows in lower tails of spillway waterworks. An algorithm, analytical solutions based on hydraulic calculations of the process of propagation and transformation of long waves described by Saint-Venant equations are constituted. These equations are nonlinear and have no exact solutions. To obtain approximate solutions these equations are linearized. The efficiency of spillways depends on how accurately hydraulic processes characteristics are measured. Control and direct measurement of characteristics of hydraulic processes in natural conditions is difficult, which requires applying methods of mathematical modeling and simulation studies of transient processes, which are based on the algorithms of functioning of transient hydraulic processes control. Introduction of the developed method for hydraulic calculation of discharge releases to streams, diverting the water from water discharge structures, allows optimize idle and non-technological discharges of water from reservoirs. Considering the highly dynamic nature of the water flow in the lower tails of the dams at concentrated releases of water discharges from reservoirs, development of new methods of hydraulic calculation of extreme discharges and water depths at the critical sections of watercourses with transient regime of water flow is an important task