Vol 43, No 2 (2016)

This study is a continuation of a cycle of studies into the effect of Atlantic climate on the hydrometeorological regime of European Russia. In this article, an attempt is made to analyze the effect of climate variations in the Atlantic on the Don basin and the hydrological regime of the Tsimlyansk Reservoir. A new composite index of heat transfer NAAII (North Atlantic Air Interaction Index) is suggested, the use of which enables the explanation of changes that have taken place in the Don basin. Evaporation was evaluated with the bathymetry of the Tsimlyansk Reservoir taken into account, and the water level of 32 m abs. was shown to be critical in the interaction between the reservoir and the atmosphere.

The Late Pliocene–Quaternary Great Caspian, in addition to the positive transgressive rhythmics shows regressions of different scales: balakhanskaya, domashkinskaya, tyurkyanskaya, venedskaya, chelekenskaya, chernoyarskaya, atel’skaya, enotaevskaya, mangyshlakskaya, and izerbashzkaya. In these periods, large-scale natural phenomena took place on the Caspian shelf, coasts, and adjacent inundated territories, including sea level drop, drying of a part of seabed, and change of landscapes and the sedimentation character. The neaped water area showed changes in water salt composition and temperature regime, along with a change in faunistic complexes. Different hierarchic state of sea level and different correlation with climate events on the surrounding territories was shown to take place during the regression with predominance of warm (interglacial) periods among them.

The contributions of wind, water baroclinicity, and evaporation to the formation of water circulation over the depressions of the Middle and Southern Caspian are calculated numerically. The results show that all three factors—the wind, baroclinicity, and evaporation—are involved in the formation and maintenance of cyclonic water circulation over the depressions. The hydrodynamic basis of the formation of upwelling at the western and eastern coasts of the Middle Caspian are analyzed. A hypothesis is proposed regarding a more complicated, binuclear structure of the upwelling at the eastern shore of the Middle Caspian, and a theoretical substantiation of this hypothesis is given. From theoretical considerations, it is derived that the upwelling at the western shore of the Middle Caspian is of wind nature, but is governed by the integral effect of the spatial distribution of wind, rather than local alongshore wind.

Mathematical simulation is used to study the biotransformation conditions of compounds of organogenic elements (C, N, P, Si) and oil hydrocarbons in the water of southeastern Sakhalin shelf. The input data for calculations were evaluated with the use of Sakhalin Shelf GIS or taken from the reference literature and materials of expedition studies. The values of water discharges through the boundaries of the zones chosen within the shelf water area and through the interface with the Sea of Okhotsk were derived from the characteristics of currents estimated by means of Bergen University oceanic model based on normal long-term monthly thermohaline parameters obtained from the Sakhalin Shelf GIS. The intraannual variations of the concentrations of organic and mineral compounds of C, N, P, and Si, as well as oil hydrocarbons because of biotransformation of substances by organisms of the community (bacteria, phytoand zooplankton) were evaluated in calculations with CNPSi-model. The results of calculations, revealing the features of the dynamics of substances, the biomass of organisms, and their activity in matter biotransformations were analyzed.

The concentrations of organochlorine pesticides (HCCH, DDT, and HCB) and 34 congeners of polychlorinated biphenyls were studied in bottom sediments of the Irkutsk Reservoir, the first in the Angara Chain of Reservoirs. The degree of pollution of bottom sediments was evaluated in accordance with classifications of regional and international standards. A correlation was found to exist between the distribution of some organic compounds and organic carbon concentration.

An intrapermafrost aquifer system, which is widespread in the sand deposits of bestyakhskaya terrace of the Lena R. (Central Yakutia), is characterized by generalized data of many-year studies of its groundwater chemistry. The groundwater discharges onto land surface through high-yield springs. The largest such source forms the Ulakhan-Taryn Creek with a mean many-year yield of 20 740 m³/day. The results of generalization were used to show the chemistry of intrapermafrost water to be stable at both many-year and annual scales, to characterize the hydraulic interaction of intrapermafrost water with suprapermafrost and subpermafrost water, to assess the spatial variations of groundwater resources in the intrapermafrost aquifer from the head-formation to the discharge domain. The results of the study are of importance for solving the problem of centralized drinking water supply to large populated localities in the Central Yakutia, including Yakutsk City.

Nutrients are important building blocks for healthy aquatic ecosystems and are generally nontoxic; but they can change with alteration in environmental parameters. The main objective of this study was to consider the seasonal variability of NO₃^–, PO₄^3– and total suspended solids (TSS) concentrations in water. The study sites, stream crossings (L30, L15) and river (R), are located in the hyrcanian forests, district 1 of Darabkola forest. The sampling was conducted in winter and spring. Water samples were taken into plastic bottles, labeled, and carried out to the laboratory for NO₃^–, PO₄^3– and TSS analysis. T-test results showed that there was a seasonal change in nutrient concentrations (p < 0.05) except for NO₃^– concentration at L30. Also, there was no significant seasonal change in TSS concentrations at all stations. Pearson correlation analysis did not reveal the same trend. Further analysis showed that the effect of road age on water quality parameters was statistically significant for PO₄^3– in spring and winter. Atmospheric precipitation plays vital role in nutrient loss and increasing concentration of suspended sediment. To prevent soil erosion from activities and discharge of wastes in the vicinity of river and stream an effective management should be planned and enforced.

The National Park of Toubkal is located in the High Moroccan Atlas Mountains, one of the regions sheltering the highest summits of North Africa (Mount Toubkal with an elevation of 4167 m). The park is characterized by very important water resources, including Ifni Lake, which is the highest natural lake in Morocco (with an elevation of 2320 m). This lake is located on the southern side of Mt. Toubkal. This area has never been the object of an environmental or hydrological study. The objective of the current study was the characterization of Ifni Lake and the spring waters located in this area, as the basis of a framework to protect natural resources in northern Africa. The hydrochemical composition of water determines its origin and relationship with its catchment. Hydrochemical studies were carried out to assess the ions water composition, and processes governing the hydrochemistry of Ifni Lake water and the springs in the study area. A total of 20 water samples were collected in 2013 and analyzed for various parameters such as pH, electrical conductivity, and major ions. The physico-chemical analysis of the Ifni Lake water showed that this is the least mineralized water studied in this region, having a bicarbonate, calcium, and magnesium as dominate ions. Also there is a relationship between the hydrochemical composition of Ifni Lake and spring waters.

Data of many-year observations (1953–2011) have been used to study the effect of changes in regional climate on water surface temperature in different types of Karelian lakes. Positive trends are identified in water temperature in the lakes over ice-free period; the amplitudes and periods of oscillations have been determined.