Korzhov Y. Hydrological conditions of the modern ecological state of the lower reaches of the Dnieper.

In this work the key hydrological factors of the modern status of the lower reaches of the Dnieper are was investigated. They include water exchange and balance characteristics, elements of hydrodynamics, hydrophysical properties of water masses, bottom sediments. In this research used a new methodological approach to the study of the hydrological regime - not as a separate element of the environment, but as an important (wired) abiotic component of aquatic ecosystems. Established that the biggest change is in the water exchange processes for the last 30 years. This led to corresponding changes in other biotic and abiotic components of the ecosystem of the lower reaches of the Dnieper. In the study of current regime of the lower reaches of the Dnieper flood waters we used a mathematical model of water circulation (method full flows). Its eligibility for assessment of hydrodynamics elements in shallow waters was proved. Major changes were identified hydrophysical properties of water masses that have occurred as a result of climate change and flow regulation of the Dnieper. The features of the formation of sediments of various water bodies of the lower reaches of the Dnieper have been analyzed. Complex analysis has result the family relationships between the main elements of the hydrological regime and biotic and abiotic components of ecosystems studied areas of the Dnieper. Recommendations for improve the ecological state of the lower reaches of the Dnieper by regulating hydrological regime elements have been proposed.