Vol 46, No 4 (2019)

The possibility of use of the previously developed calculation technique of the North Rivers flow hydraulic records for the Ob River, the largest river in Russia by basin area, flowing under severe conditions in West Siberia was examined. The calculation technique is based on the model of heat and moisture exchange of the geological substrate with the Earth’s atmosphere, the Soil−Water–Atmosphere–Plants (SWAP) model, in conjunction with information support based on global databases of geological-substrate parameters and information obtained from observational data collected by weather stations within the Ob River basin. Uncertainty of the Ob River flow was assessed. Additionally, the ability of the SWAP model to reproduce multiyear dynamics from average values of snow reserves in the Ob-Irtysh basin was examined.

Systematization of analyzed schemes of alongshore mobilization of sediments off the east coast of the Gulf of Danzig was conducted. Significant differences in the structure and localization of the countercurrent flows in convergence zones were detected. The results of near-bottom steady-state measurements of currents in the vicinity of the Baltic Canal in the depth range 6–16 m demonstrated that >6-m/s winds cause the alongshore currents to be reoriented in the direction of the alongshore wind component. The morphodynamic accumulative criterion (the filling of the re-entrant angle and abrasion in the obstacle-shadow zone) and “abrasive” criterion (the orientation of abrasion kettle holes at the ends of breakwalls) were examined. The abrasive criterion is apparently preferred over the accumulative one during transportation of sediments along segments of the coast where waves approach the coast at normal or near-normal angles. Peculiarities of the mechanism of the northward transportation of sediments, bypassing Baltiysk backwalls and changing from abrasive to accumulative criteria for different segments of the coast, are demonstrated. Two schema representing the opposite Vistula and Sambiysky alongshore flows of sediments are proposed: prior to construction of the backwalls facing Baltic Canal incoming waters with the vast area of migration at the north end of the Vistula bar, and the post-construction backwalls with the resulting narrowing of the area and displacement of its south boundary on the north side to the level of these backwalls.

On the basis of data-array analysis (2000–2011) of phytoplankton in large subarctic rivers; the rivers’ hydrochemical, hydrological, and morphological parameters; and climatic properties of the catchment-basin areas and by using stepwise discriminant analysis and clustering, it was determined that formation of phytoplankton spatial structure is mostly affected by climate rather than by physical-chemical properties of the river waters in northeastern Siberia. Floristic structure of phytoplankton is mostly connected to abiotic factors among phytoplankton-development indicators. The duration of vegetation-growth period is another important environmental factor.

Mass-spectrometry with inductively coupled plasma was applied to determine the dissolved forms of 26 elements in the water of lakes of the Mul’tinskii Basin. Specific features were identified in the formation of water chemistry in the water bodies of high-mountain Altai territories which suffer little anthropogenic impact. Water quality and the effect of natural factors on it were assessed.

Results of examination of the spatiotemporal dynamics of the hydrochemical mode on discrete aquatic areas of the riverine aquatic complex of a small river during 2001–2010 are presented. Each discrete area examined individually has its own hydrochemical peculiarities.

Applied analyses of a number of datasets containing several highwater-forming storm rainfall events (intense rain for short time periods) per year are examined. The use of data containing several events per year is demonstrated as justified for reliable determination of statistical properties of time series derived from short observation periods. The statistics of time series containing one to several events per year in the Ural Mountains are shown to be well correlated with the frequency of the observed events. Recommendations for recalculation of the time-series statistics containing several events per year versus statistics for one event per year were developed, and a brief comparative analysis of the methods used in Russia is provided.

This paper is dedicated to the anniversary of Alexander Naumovich Gelfan, doctor of physical and mathematical sciences, director of the Water Problems Institute of the Russian Academy of Sciences. The most prominent scientific achievements of A.N. Gelfan in mathematical modeling of the hydrological cycle of river basins are presented, as well as the results of application of the geoinformational modeling complexes. The results of organizational activity of A.N. Gelfan and his participation in international organizations are reviewed.