Sediment yield of Kamchatka Krai rivers into the Pacific Ocean and the seas of Bering and Okhotsk, is evaluated, including that from the drainage basins that are not covered by regular observations. Regression dependences of specific suspended sediment yield (SSSY) on factors determining it were constructed for erosion regions identified in Kamchatka Krai. The total average many-year yield of suspended sediments of Kamchatka Krai rivers into the Pacific is 11.4 × 106 t/year, 73.9% of which is transported by rivers of the eastern coast and 26.1%, by those of the western coast. Among other factors, such distribution is attributed to the location of the majority of volcanoes on Kamchatka eastern coast. About one third of all sediments transported from Kamchatka Krai territory is discharged by the two largest rivers in the region, i.e., the Penzhina and Kamchatka.

The specific features of formation of maximal water levels in the lower Amur R. are studied. They are correlated with streamflow formation factors in different parts of the Amur Basin and Zeya R. flow regulation. Water level variations in high-water season of the year were analyzed for 1955−2013, including the periods of natural runoff variations (1955−1979) and after the start of Zeya Hydroengineering Structure operation (1980−2013). Five phases of seasonal level rise and water discharge increase in the Lower Amur are identified, and the role of higher discharge, which forms in the river basin in years with different water abundance, is assessed in the absence and presence of the effect of economic activity on the annual streamflow distribution.

Исследованы закономерности пространственно-временной изменчивости характеристик стока взвешенных наносов. На основе анализа разностно-интегральных кривых стока установлено, что для большей части рек на территории Камчатского края характерно наличие двух относительно продолжительных периодов изменения стока взвешенных наносов – увеличения до конца 1970-х – начала 1980-х годов и его последующего уменьшения. Данная закономерность нарушается в реках, испытывающих воздействие вулканических извержений, где наибольшее возрастание стока наносов наблюдается после крупнейших извержений. Значительно уточнены существующие карты распределения средней многолетней мутности воды (выделено 18 зон вместо 4) и среднего многолетнего модуля стока взвешенных наносов (выделено 13 зон вместо 2). Построена карта распределения гранулометрического состава взвешенных наносов (на территории региона выделено 3 зоны). Показано, что максимальные значения среднего многолетнего модуля стока взвешенных наносов (свыше 500 т/км2∙год) и мутности воды (более 1000 г/м3), а также крупности частиц наносов наблюдаются в водотоках вулканических территорий; минимальные величины мутности, модуля стока взвешенных наносов, а также крупности частиц характеризуют материковую часть края.

Active bed forms of three major classes are formed in Terek lower reaches during summer floods. They include ripples, dunes of the first order, and dunes of the second order (from smaller to larger), which commonly form an incomplete hierarchy. The morphology of the bed forms is essentially stochastic and can be adequately described by probability distribution functions of bed form characteristics for some narrow ranges of hydraulic flow characteristics. At the same time, the mean values of bed form morphometric characteristics (length, height, and asymmetry) show stable relationships with flow velocity and depth. The celerity of active dunes can be adequately described by a modified Snishchenko–Kopaliani formula. The channelforming sediments that move as bed forms in Terek lower reaches account for 7% of sediment transport rate of all channel-forming sediments, a value near the lower limit for rivers with sand alluvium.

This paper considers the influence of volcanic eruptions on the variation in the characteristics of the runoff of the suspended river load (suspended sediment concentration, discharge, rate of runoff, and grain-size distribution) on a variety of space–time scales (daily, seasonal, and long-term). The main factors that affect the yield of suspended load in rivers that flow in volcanic areas include the water runoff, drainage area, and the abundance of unconsolidated volcanic deposits. The areas of recent volcanism in Kamchatka are characterized by the maximum values of potential scour of particles, the mean long-term suspended sediment concentration, and specific suspended sediment yield. The largest increment in the transport of suspended river load in areas of volcanic activity is observed after major eruptions. The daily variations in the transport of suspended load are controlled by the water regime of rivers on the slopes of active volcanoes, namely, periodic cessations of surface runoff because of filtering into volcanic deposits.

The current features of the space and time variations of river runoff in Kamchatka Krai have been considered. Two relatively long cycles have been shown to exist in water runoff variations in the major portion of the examined rivers. The renewable water resources were increasing until 1970–1980, while in the following years (up to 2010), they were gradually decreasing. Current data on river runoff were used to prove the existence of three zonal types of water regime in Kamchatka Krai; five azonal types of annual runoff distribution are characterized. One of them (nearly uniform annual distribution caused by the predominance of groundwater recharge) has been theoretically predicted in the classification proposed by M.I. L’vovich, though without factual confirmation. The specific features of water regime of rivers whose basins lie on the slopes of active volcanoes are considered for the first time. This type of regime typically shows alternating periods of the presence and absence of surface runoff in river channels, corresponding to the inflow of snowmelt or rainfall runoff at high level of subsoil water (when channel deposits are fully saturated with water) or at its low position (when moisture is deficient).

Inundatios on the Black Sea coast of Krasnodar krai between 1945 and 2013 have been analyzed. The main genetic types of inundations on the coast have been identified. The specific features and regularities of inundation wave transformation along the rivers and over time have been studied. Seasonal and maximal runoff of Black Sea rivers has been analyzed over a long-term period. Regularities in the variations of the number of inundatios and their characteristics over the coastal area have been revealed both at the annual and long-term scales. Quantitative estimates are given to the hazard and damage to the population and economic activity due to inundations in the valleys of Black Sea rivers.

For solving the problems of analyzing the 2013 flood within the Amur river basin we undertook an array of investigations including field work, a statistical processing of hydrological monitoring results, a hydrodynamical modeling, calculations of the flood flow regulation in the simulation mode, a study of flow formation, etc. We discuss the formation conditions of the highest discharges and levels for the flooding process, and examine the state of knowledge concerning the drainage basin, and the methods of assessing the calculated hydrological characteristics. An analysis is made of the processes of directional accumulation in the lower reach of the Amur, and their effects on the degree of flood hazard. It is shown that the height of flood in the lower reach is influenced, in addition to economic development, by specific factors caused by alluvium accumulation in the river valley. The study revealed a substantial decrease in discharge capacity of the river channel in the area of the Khabarovsk water node and downstream, including as a result of the measures for purposeful streamflow redistribution between the branches, which contributed to an increase in water surface elevations in 2013 to extreme values. An analysis of the water levels in the middle and lower reaches of the Amur was made using a package of models to demonstrate that the existing nonstationarity of changes in water surface elevations is largely due to the streamflow regulation as well as to the various types of anthropogenic impact on the state of the channel and floodplain, and on the hydraulic state of the water flow.

The objectives and principles of organization of hydrological monitoring at international (transboundary and boundary) rivers of Russian Federation are discussed. We developed an international rivers classification which concern their location in relation to national boundaries and further used for the optimization of hydrological monitoring network. Rivers in the basin of the Amur and the Selenga are used as an example to discuss the problems of introducing special technologies into the practice of hydrological monitoring under the incomplete hydrometric knowledge of international rivers. Perspectives of the application of methods of water regime assessment, remote sensing application to river hydrology, and mathematical models of pollutant transport are demonstrated.