Kushnir D. Variability of the hydrological characteristics of the lagoons of North-Western Black Sea region under conditions of regulated water exchange with the sea (as applied to the Tylihulskyi Lyman and the Kuyalnytskyi Lyman lagoons)

This Ph. D. thesis is devoted to solving the relevant scientific problem of determining the appropriateness and effectiveness of different techniques for stabilization of the hydrological regime of the substantially isolated (“closed”) lagoons of North-Western Black Sea region in the 21st century (applied to the Tylihulskyi Lyman and the Kuyalnytskyi Lyman lagoons), taking into account the regulated water exchange with the sea through hydraulic structures, water management activity and climate change. An author has developed and tested a new methodological approach to the usage of the modern numerical non-stationary 3-D hydrodynamic model Delft3D-FLOW, which was applied for solving actual problems, related to the development of the scientific justification of water management plans for the lagoons under climate change in the XXI century. Based on the results of numerical simulation, the new characteristics of the spatial structure of three-dimensional wind-induced water circulation and the formation of thermohaline stratification in the Kuyalnytskyi Lyman and Tylihulskyi Lyman lagoons were determined for the first time. Scientifically based recommendations for the water management plans of the Tylihulskyi Lyman and the Kuyalnytskyi Lyman lagoons have been developed in order to stabilize their hydrological and, as a result, hydroecological regimes, under the conditions of climate changes, occurring in the XXI century. The possibility of applying the methods of numerical hydro- and thermodynamic modelling for developing the scientific justification of water management plans for other “closed” lagoons of the North-Western Black Sea region is shown.