Hydroecological Problems of Dairy Estuary in Connection with the Instable of its Communication with the Azov Sea

Abstract

Purpose. To identify the existing hydrological problems of the connecting channel between the Milky Liman and the Sea of Azov, due to insufficient morphometric performance of the channel. Methods. The analysis of hydroecological changes in the Dairy Way is the creation of a bulk model of the water body. Given the lack of a depth map, field mapping of the bottom of the studied reservoir was carried out. In order to calculate the volume of the water body of the Dairy estuary in 2012, eight transects were laid on which depth measurements were carried out through each 200 m measuring track. Measurement points were recorded using GPS. On the basis of the obtained data using the 3D Analyst module, a digital bottom relief model was constructed. His made it possible to calculate the volume of water in the estuary. Retrospective data of water volumes were calculated on the basis of measurements of the maximum depth of the estuary, obtained by the authors by way of measurements in certain years. To calculate the elements of water balance, the data of O. Dyakov was used.The transverse profile of the connecting channel is obtained as a result of field depth measurements in transects. The velocity of the flow in the channel and its throughput were determined according to the standard methods adopted in the hydrology, taking into account the direction and force of the offensive phenomena. Results. The hydrological and hydrochemical problems of the Dairy Estuary as the key territory of the Azov National Natural Park, a hydrological reserve of national importance and a wetland of international importance are analyzed. Their direct dependence on the unstable functioning of the connecting channel between the estuary and the Sea of Azov has been revealed. A historical cut of the features of the functioning of the ravine channel is shown. A digital 3D model of the estuary bottom has been built and the changes in the water level during different time periods are shown. A spatio-temporal analysis of the dependence of hydrological and hydrochemical indicators of the estuary on the channel functioning state has been made. It is revealed that the existing parameters of the connecting channel do not ensure the full functioning of the Molochny Liman and the fulfillment of ecological functions by it. Environmental changes that occur as a result of unstable and periodic connection of the estuary to the sea through the channel are analyzed: changes in water salinity, species diversity of invertebrates, fish and birds, areas of shallow water areas as feeding places for riparian birds, changes in the biological productivity of the estuary water area. Scientific novelty: On the basis of morphometric measurements of the connecting channel and the waters of the Milky Way, we have attempted to calculate the water supply capabilities of the estuary through the connecting channel and its functioning as a hydrological object. Conclusion: The adequate width and depth of the connecting channel and the regular connection of the Dairy estuary with the sea will lead to the restoration of hydrological and hydrochemical regimes to the ecologically optimal parameters. On the basis of this biological diversity in the estuary will be restored, its socio-economic and ecosystem functions will be renewed.