Impact of River Flow Regulation on Deltas in the Black Sea Basin

The study aimed to analyse the impacts of flow regulation and economic activity on river deltas in the Black Sea Basin (Rioni, Chorokhi, Kizilirmak, Dnieper, Dniester, and Danube). The relevance of this problem is because changes occurring in deltas significantly affect their natural resources and the prospects for their use. A comparative analysis of the deltas of the basin allows us to show the features and scale of changes occurring in them. The main methods used for this investigation were cartography, GIS modelling, and some field expedition routes. Natural conditions, delta morphology, sediment transport, flow discharge, and land use shape the features of delta transformation in these rivers. Erosion processes are observed as sediment accumulates in deltas exposed to coastal currents and waves (Rioni and Chorokhi in Georgia, Kizilirmak in Turkey). River flow regulation by reservoirs has reduced the flow of water into the delta and has decreased sediment influx. Deltas of the Dnieper and Dniester Rivers in Ukraine mostly depend on water releases from reservoirs. It is noticed that both the sea and the river influence the Danube Delta. The results obtained are useful for the construction and operation of infrastructure in deltas; the use of these areas for recreation, agriculture, and forestry; the protection of Ramsar wetlands; and the creation of new human settlements.