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We studied a scour in a drainage canal of the Cheboksary hydrosystem tailrace on the Volga river. To protect the hydrosystem tailrace from scouring, we proposed flexible stream-guiding grids that are installed in the stream and effectively affect its kinematics in the bottom area. We calculated in MathCad a system of vortices that occur when the flow runs against adjacent plates of a grid. Due to the replacement of flexible elements of a grid with flat plates that divide the flow into separate jets, it became poss...

Based on the analysis of contamination of hydrosystem headraces with floating materials, we developed a system of protective facilities, including protective booms, abutments and bottom mats, guiding booms. To justify the operation of the developed facilities, automated calculations of the listed guiding and retaining facilities were performed. The main attention was paid to the experimental study of the facilities. As a result of the experimental studies, we determined values of forces in a ground sill, depending...

The paper examines the results of a series of field observations carried out on the Atlantic coasts of France polluted by heavy fuel oil spilled due the accident of the tanker ?Erika? in December 1999. The aim of these observations is to determine the rates of the spilled fuel oil natural degradation and to consider their relationship with principal environmental factors. It is a part of a larger-scale research being performed on geographically different oiled seacoasts in France, Spain, and Russia. In France, eig...

Parameters of local scours in an unprotected part of the riverbed behind the hydrosystem end structures are determined by distribution of kinematic characteristics of the flow. The kinematic characteristics in cross-sections of a natural part of the riverbed depend on a number of factors, including the bottom roughness, flow depth and water surface slope. To calculate the velocity distribution over the cross-section of the drainage channel, we used Navier?Stokes equations for the uniform steady turbulent motion. W...

We studied the reasons of the formation of local scours in the Cheboksary hydrosystem tailrace on the Volga river. To determine the parameters of the scour basin, we calculated the spatial conjugation of the races in MathCad application software environment. The morphological analysis of soft shells allowed us to establish characteristics of mobile baffles required for protection of the hydrosystem tailraces from scouring. For the formation of an induced vortex flow directed opposite to the channel flow, we propos...

The paper examines the results of field observations carried out on the Galician coasts of Spain hardly polluted in 2002 by fuel oil spilled from the sunken ?Prestige? tanker in order to determine the rates of the pollutant natural destruction and to consider their relationship with principal environmental factors. It is a part of a large-scale research being performed on geographically different oiled seacoasts in France, Spain and Russia. In Galicia, the observations were undertaken in October 2012, November 201...

Calculation of the local scour behind the hydrosystem tailrace structures is associated with determination of hydraulic flow parameters, characterized by a sudden increase in the depth. The flow parameters are calculated on the basis of T. von Karman's integral momentum equation for a submerged turbulent jet. The flow in the hydrosystem tailrace, in accordance with the approach of G. N. Abramovich, is considered as a set of a submerged turbulent jet, a vortex area, and a main flow in the tailrace passage. It allow...

Parameters of local scours in an unprotected part of the riverbed behind the hydrosystem end structures are determined by distribution of kinematic characteristics of the flow. The kinematic characteristics in cross-sections of a natural part of the riverbed depend on a number of factors, including the bottom roughness, flow depth and water surface slope. To solve the problem of calculating the velocity distribution over the cross-section of the drainage channel, we used Navier - Stokes equations for the uniform s...

The present paper is devoted to the results of long-term field observations of oil pollution transformation in sma ll watercourses of the Lower Don River basin (Russia), on the Atlantic coast of France and in the Strait of Kerch polluted by spilled oil. The investigations included visual assessment and sampling of oil slicks, water and sediment cores. The analysis of samples were carried out with the use of th in layer and column chromatography, optical and gravimetri c methods making possible to determine separat...