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Water Resources - River deltas which are among the most variable and vulnerable geographic objects may be considered as effective indicators of large-scale global and regional, natural and... 相似文献
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Water Resources - The article presents a study of the hydrological regime of the Lena and Mackenzie rivers, flowing in the zone of permafrost rocks of different types. Features typical of river... 相似文献
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A mathematical model has been developed to assess the role of the shape of channel cross-section, the position of pollutant source on the bank slope, and the sedimentation rate of pollutant particles in the process of pollutant transport in water flow. The procedure of numerical experiments and the obtained results and conclusions can be of use in the simulations and studies of pollution propagation from sources on riverbanks in permafrost zone, which are subject to thermal erosion. 相似文献
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E. N. Dolgopolova 《Water Resources》2017,44(6):808-819
The factors that govern the distribution and transformation of tidal waves in the macrotidal estuary of the Mezen River have been considered, including tide range in the mouth section, water discharge in the river’s lower reaches, estuary shape, and bed resistance coefficient. Data on variations of water discharge over period 1920–2008 are given. The parameters of estuary channel narrowing in horizontal and vertical sections have been considered. The effect of narrowing and bed hydraulic friction on tide wave amplitude has been evaluated. Froude number values for the tidal estuary suggest that tidal bore can form at the Mezen mouth. The conditions of the propagation of tidal waves to the mouths of different rivers and tidal bore formation in them are considered. 相似文献
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The effect of sediment yield of a stream and the energy of sea waves on the formation of bars and their dynamics at nontidal river mouths is demonstrated. Data on variations in the hydrological regime of the Potapovskii and Bystryi branches in the Danube Delta and the morphodynamics of their bars are given. Major problems of mathematical modeling of the formation and progradation of mouth bars into the sea are discussed. An analytical expression is obtained for the shape of the foreset slope of a bar, which moves over a constant-slope seabed. The results of simulation were checked against data on the Potapovskii and Bystryi branches in the Danube Delta. 相似文献
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Debol'skii V. K. Dolgopolova E. N. Eshchenko L. A. Kotlyakov A. V. Nasonov A. E. Koreneva V. V. 《Water Resources》2003,30(1):42-46
The ratio of the energy of water release into the lower pool of a waterworks facility for the time of release to the energy generated by the long-wave component of the wave spectrum caused by the release is considered. The effect of long-wave components of the wave spectrum on the channel and shore deformations is evaluated. An empirical relationship is proposed to describe the dependence of flow velocity on the release characteristics. Analysis of exchange processes between the flow and bottom deposits along with the obtained relationships is used to assess possible pollutant release from bottom deposits into water. 相似文献
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The dimensionless Darcy–Weisbach coefficient of friction is used to evaluate the drag in channel flows. A developed turbulent flow with a quadratic drag law is considered. The dependence of the coefficient of friction on the cross-section shape of the channel flow is examined. A coefficient of the channel shape is introduced, which depends on the wetted perimeter and the flow width and allows the complicated geometry of the river cross-section to be taken into account in calculating the drag. The drag estimates calculated using the suggested technique are compared with other authors' estimates for flumes and rivers. 相似文献
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Water Resources - The relationship between turbulent diffusion with Eulerian and Lagrangian scales of turbulence in natural flows is considered. An estimate of the depth-averaged Lagrangian time... 相似文献
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The general geographic, hydrographic, climatic, and hydrological characteristics of the Congo R. basin are considered. The major features of the riverine and marine factors that have their effect on the hydrological regime and morphology of the delta and estuary of the Congo R. are identified; the effect of a submarine canyon on the morphological features of the estuary is analyzed in detail; and changes in river delta structure in the XX century and currently are considered. The hydrological—morphological characteristics of the largest mouths of African rivers, the formation conditions of water and sediment runoff, and variations of their deltas are compared. 相似文献