System model of integrated management of the water resources of the Ingulets River by a basin principal
Authors: Kovalchuk V. P. , Kovalchuk P. I. , Yatsyuk M. V. , Kovalenko R. Yu. , Demchuk O. S. , Balykhina H. A. 
Published: July 2020

For integrated water management in river basins in Ukraine, there is no toolkit for system modeling and selection of management structure in river basins according to environmental and economic criteria, which corresponds to the creation of water management systems under conditions of sustainable development. Therefore, the urgent task is to develop a system model of integrated water management on the example of the Ingulets River basin.
The purpose of the work is to create a system model of integrated water resources management in Ingulets River basin, which provides scenario modeling of technological solutions, their evaluation and optimization of economic criteria for efficient water use under environmental constraints and criteria for achieving a good or excellent ecological status of the river basin.
The system model is used as a toolkit, the method of decomposition of the river basin into subsystems, analysis of subsystems and their composition into a holistic model of integrated management by the basin principle. Telecommunication methods are proposed to improve monitoring. A method of scenario analysis is proposed, which performs simulation modeling of prospective management scenarios at the first level of the hierarchy, and at the second level - options are evaluated according to the criteria of cost-effective water use with environmental objectives and regulatory restrictions. For simulation modeling, a system of balance difference equations for the dynamics of water masses, mixing and spreading of pollution in rivers and reservoirs is formalized. A system of combined control for the impulse method of river washing was developed. Multicriteria optimization of variants of the control structure is carried out on the Pareto principle.
A system model has been developed for integrated water resources management in the Ingulets River basin that meets the requirements of the EU Water Framework Directive on the establishment of cost-effective water use while ensuring good or excellent ecological status of rivers. The structural and functional diagram of the system model includes the subsystems: the water supply subsystem of the Dnipro-Ingulets canal; a subsystem for flushing the Ingulets River from the Karachunivske reservoir and displacing the saline prism into the Dnipro River; subsystem of environmental safety when discharging pollution into the river Ingulets; subsystem of water supply for irrigation in the Ingulets irrigation system, prevention of soil salinization. A system of technological, economic and environmental criteria for evaluating integrated management by the basin principle has been developed.
They include maintaining the water level in reservoirs, displacement of salt water prism and limitation on water quality, ensuring the ecological condition of the river, and the dynamics of water resources consumption. Technological criteria determine the maintenance of water levels in reservoirs. Cost-effective water use is estimated on the basis of the dynamics of water consumption for river washing and irrigation.
The formalized integrated management system in the Ingulets River basin includes operational water resources management and structure management. Integrated management is carried out according to subsystems, types of management and a system of criteria. For operational management the balance differential equations of water exchange in reservoirs are formalized. A two-layer model of water masses dynamics, pollutants distribution and mixing when flushing rivers from reservoirs is used.
Scenario analysis is offered to select the optimal structure of the management system. Simulation scenarios are being simulated. Scenario optimization is performed on the Pareto principle.
An example of evaluating the effectiveness of the proposed system and its comparison with the existing regulations for Ingulets River flushing is given.