Calculating Sediment Transport in the Coastal Zone of the Sea

The mathematical model described is intended for the prediction of anthropogenic sediment transport in the coastal zone of the sea. Calculation results are presented.     

Concept of Water Resources System Management Based on the Combined Use of Surface and Subsurface Waters

A conceptual basis is proposed for the solution of management problem of water economy systems based on the combined use of surface and subsurface waters. Specific features of the development of groundwater deposits in the context of this problem are discussed. Management of cooling systems of power plants based on the combined management of surface and subsurface water resources is considered as an example.     

Modeling flows in permeable pressure systems and channels

The study is focused on the velocity and pressure distributions in flows in pipeline systems, as well as hydrological parameters of open flow examined on the basis of Saint Venant equations with allowance made for lateral inflow and the equations of motion of incompressible fluid in perforated or porous pipes. Some analytical solutions are given for the formulated boundary problems, which can be applied to the calculation of operation regimes of sprinkling machines of the “Fregat” or “Valey” type.     

Nonlinear aspects of phreatic water filtration

Horizontal gravity filtration of groundwater in soil is considered. Under Boussinesq approximation, the problem is reduced to a one-dimensional nonlinear parabolic equation in phreatic water level. The problem of linearizing the original equation is discussed. The comparison of gravity-filtration problem solutions in the nonlinear and linearized formulations shows considerable discrepancies to exist between the solutions, especially, for boundary problems with mixed boundary conditions, when the value of the function is not fixed on the right boundary. An analytical solution is obtained for steady-state flow from a water body into the soil with subsequent leakage into underlying beds. Two regimes are shown to exist: one with an infinite exponential tail, and another in the form of a finite groundwater mound. A new approach is proposed to the linearization problem—quasilinearization with the use of the Burgers equation.     

Seawater intrusion into coastal aquifers

The hydrological, hydrophysical, and hydrochemical aspects of the interaction between marine waters and groundwater in the adjacent land territory as a manifestation of the general process of interaction between surface and subsurface waters. Most attention is concentrated on the marine water intrusion into aquifers. Recent achievements in the field of modeling seawater intrusion into coastal aquifers are reviewed.     

Modeling Salt-Accumulation Processes in Subsoil Waters in Areas with Insufficient Moistening

Equations of flow in water-saturated porous medium and advection diffusion of dissolved salts are used to study salt transport and accumulation in subsoil water. One-dimensional and two-dimensional models of joint movement of subsoil water and dissolved salts are proposed based on the generalized law of liquid flow in porous medium with the density depending on the concentration of dissolved substances. The models allow taking into account various hydrological and hydrophysical factors affecting mass transport.     

Modeling of Flow at Hydraulic Structures in the Shelf Zone of Seas

A technique for numerical modeling of hydrodynamic fields at a hydraulic structure on the shelf of a marginal or closed sea is described. Examples of calculations for a specific facility in the shelf zone of the Northern Caspian Sea are given.     

Modeling Water Flow in the Presence of Higher Vegetation

The notions of hydromechanics of continuum with a complicated structure are used to formulate a closed spatially homogeneous mathematical model of water flow within higher aquatic vegetation (HAV) canopy. Model equations are applied to the analysis of the vertical structure of a turbulent flow in a vegetated open channel. Test calculations are made. The results of calculations and experimental studies of water flow characteristics within vegetation communities in some water bodies [1, 6–8, 10, 14] are shown. The difficulties in implementing such experiments require improving the methods of mathematical simulation of water flows through HAV.