Изменение стока снегового половодья на южном макросклоне Русской равнины в период 1930–2014 гг

In recent decades, in the southern macro-slope (catchment) of Te Russian Plain, mainly within the basins of the Volga and the Don rivers, the spring flood flow decreased due to both anthropogenic and climatic factors. Of anthropogenic factors, the creation of reservoirs played a signifcant role in changing the water regime of the Volga and the Don. Another important factor, affecting the river runoff, is agricultural activities on flat interfluves and slopes. Compared with the conventional-natural period (for the Volga from 1879, and for the Don from 1876 to 1929) to the date (for the period 1930–2014), the flood flow of the Volga has been decreased by more than 4300 km3, and the Don – by almost 900 km3. Te contribution of anthropogenic factors to this decrease in the Volga basin exceeded 70%, and for the Don it was equal to 45%, while the climatic ones contributed 30 and 55%, respectively. During the period of instrumental observations on the rivers of the region, long-lasting phases of high/low water content with duration from 15–20 to 90 years or longer, caused by the climatic changes, were determined. Tese are a characteristic feature of long-term changes in flood flow (and in a runoff of other seasons) on both medium and large rivers of the southern macro-slope of the Russian Plain. Te period since early 2000s was a start of the decreased flood flow everywhere, i.e. on medium and large rivers. It is most clearly (by tens of percent) manifested in the decrease of the spring surface flow due to the following factors: more frequent thaws, reduction of the depth of soil freezing, increase of infltration, especially in the forest-steppe and steppe zones. Increase in flow of the infltration origin does only partially compensate the decrease of the flow in rivers.Рассматриваются сток снегового половодья в пределах бассейнов Волги и Дона и его изменения под влиянием антропогенных и климатических факторов. Изложены методы исследования изменений речного стока, оценены его изменения за последние десятилетия. Общая тенденция – уменьшение стока половодья, что связано с гидротехническим воздействием и климатическими факторами

Self-propagating high-temperature synthesis of Ti-Al dispersion materials and protective coatings based on them

Translated from Russian (Fiz. Khim. Obrab. Mater. 1995 (2) p. 73-79)SIGLEAvailable from British Library Document Supply Centre-DSC:9023.190(VR-Trans--8563)T / BLDSC - British Library Document Supply CentreGBUnited Kingdo

The ensemble scenarios projecting runoff changes in large Russian river basins in the 21st century

An approach is presented for carrying out a long-term projection of river runoff changes in large Russian river basins in the first three decades of the 21st century. These changes may be caused by climate warming and socio-economic factors. The approach utilizes a method for scenario estimation of runoff changes with a range of possible climate warming effects. This range is chosen by generalizing calculation results obtained by using an ensemble of global climate models for two contrasting scenarios (A2 and B1) of globally-averaged air temperature rises. The approach also utilizes a method for alternative scenario estimation for water consumption as related to socio-economic changes. The estimates show that the expected runoff changes in the first third of this century due to climate warming scenarios can compensate the runoff decrease caused by the realization of some of the scenarios for socio-economic changes in the Volga River basin. The same compensation does not occur in the Don River basin, where negative effects are expected for the regional ecology

INTEGRATED PROJECTION FOR RUNOFF CHANGES IN LARGE RUSSIAN RIVER BASINS IN THE XXI CENTURY

The paper discusses an approach to a long-term forecast of river runoff changes for Russian large river basins in the first third of the XXI century caused by climate warming and social-economic changes. The approach considers runoff changes under a range of possible climate warming effects. This range is chosen by generalizing the calculation results obtained by using an ensemble of global climate models within CMIP 3 and CMIP 5 experiments for twocontrasting scenarios (A2/RCP 8.5 and B1/RCP 2.6) of globally averaged air temperature rises. The approach also utilizes a method for alternative scenario for water consumption related to socio-economic changes. The obtained scenario estimates show that expected changes in the Volga and Don annual river runoff and its intra-annual distribution in the first third of this century can be relatively small, while changes in water use characteristics may be extremely negative in some scenarios, especially in the Don River basin

Carbon balance of a southern taiga spruce stand in European Russia

We present results from nearly three years of net ecosystem flux. measurements above a boreal spruce stand growing in European Russia. Fluxes were measured by eddy covariance using conventional techniques. In all years examined (1998-2000), the forest was a significant source of carbon to the atmosphere. However, the magnitude of this inferred source depended upon assumptions regarding the degree of "flux loss" under conditions of low turbulence, such as typically occur at night. When corrections were not made, the forest was calculated to be only a modest source of C to the atmosphere (3-5 mol C m(-2) yr(-1)). However, when the corrections were included, the apparent source was much larger (20-30 mol C m(-2) yr(-1)). Using a simple model to describe the temperature dependencies of ecosystem respiration on air and soil temperatures, about 80% of the night-time flux was inferred to be from soil respiration, with the remainder being attributable to foliage, branches and holes. We used reasonable assumptions to estimate the rate of ecosystem respiration during the day, allowing an estimation of canopy photosynthetic rates and hence the annual Gross Primary Productivity of the ecosystem. For the two full years examined (1999 and 2000), this was estimated at 122 and 130 mol C m(-2) yr(-1), respectively. This value is similar to estimates for boreal forests in Scandinavia, but substantially higher than has been reported for Canadian or Siberian boreal forests. There was a clear tendency for canopy photosynthetic rates to increase with both light and temperature, but the slope of the temperature response of photosynthesis was less steep that that of ecosystem respiration. Thus, on most warm days in summer the forest was a substantial source of carbon to the atmosphere; with the forest usually being a net sink only on high insolation days where the average daily air temperatures were below about 18 degreesC. These data, along with other studies on the current balance of boreal ecosystems, suggests that at the current time many boreal forests might be releasing substantial amounts of carbon dioxide to the atmosphere. This observed temperature sensitivity of this ecosystem suggests that this might be a consequence of substantially higher than average temperatures over recent years