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Purpose: to study soil erosion on slopes with forest belts during snowmelt runoff. Methods. The studies were carried out in the basin of the river Kundryuchya (Rostov region), erosion was determined by the method of ravine volume. Results. With the growth of forest belts, snow plumes, where soil particles accumulate, gradually reform the granulometric and microaggregate composition, which is reflected in the structural state of the upper soil layer and the values of various coefficients and indicators characterizing the increase in water permeability and the decrease in washout. On the compacted arable land near forest belts (zone 5 H), an increase in the weight of winter wheat roots by the pre-winter period was recorded. A complex picture of the structural state and soil erosion in inter-strip fields is represented by equations and graphs showing a soil washout increase in the bare fallow area distancing from forest belts and an erosion decrease when approaching them. In the open area of bare fallow, soil erosion increases continuously with distance from the watershed. Soil erosion is minimal on winter wheat crops near forest belts. On an open slope, erosion is minimal at the watershed, increasing downslope. However, at the bottom of the slope (400–450 m from the watershed), erosion is suppressed by accumulation. Conclusion. Forest belts on slope fields activate accumulation processes, reducing erosion, not only by regulating the snowmelt water flow under the forest canopy, but also as a result of the reformation of the structural state of the upper soil layer during long-term fallout in snow plumes of silty, clay and other soil fractions introduced by the surface drain. On compacted arable land, the mass of winter wheat roots near forest belts has an additional effect on soil erosion. In an open area of a fallow field, soil erosion increases from the watershed to the bottom of the slope. On winter wheat crops on an open slope, soil erosion at the watershed is minimal, increasing towards the center of the slope, but at its bottom, accumulation suppresses erosion.

Разработана математическая модель снегонакопления и снеготаяния для бассейна Волжско-Камского каскада, предназначенная для расчета распределения запасов воды в снеге на водосборе в целом и объемов запасенной воды для каждого водохранилища каскада. Модель реализована в виде компьютерной программы и при необходимости позволяет выполнять ежедневные расчеты. Опыт эксплуатации программы в 2017 - 2019 гг. показал её высокую эффективность и хорошее соответствие данным снегомерных съемок., Snowpack formation and snowmelt mathematical model was developed for Volga-Kama cascade. The model is designed to compute water equivalent of snow for the whole watershed and for each of water reservoirs of the cascade. The computer program based on mathematical model was created. It allows to perform computations on daily basis. The program use from 2017 to 2019 proves its high efficiency and accuracy., №2 (2020)

The relevance of the research is caused by the need to study sedimentation in urbanized area, which reduces the quality of urban environment and has negative effect on ecological situation. The main aim of the research is to analyze the meteorological conditions of surface sediment runoff formation in a large city during the intense spring snowmelt. Objects of the research is the urbanized area of the city of Yekaterinburg. Methods: study of meteorological conditions for the cold periods of 2015–2016 and 2016–2017, as well as in the spring seasons of 2016 and 2017; assess the features and differences of meteorological parameters and processes that had a major impact on the sediment runoff in the spring of 2016 and 2017. Results. The meteorological conditions of the cold periods 2015–2016 and 2016–2017 and the spring seasons 2016 and 2017 were reconstructed. Meteorological parameters and processes that had a significant impact on the sediment runoff in the urban area such as thermal regime of ground air, precipitation, snow cover, snowmelt, and freezing and thawing of soils were studied. The significant diference between meteorological conditions of the spring of 2016 and 2017 was found, that reflected in sedimentation and formation of more intense mud deposition in 2016. The following factors appear to be crucial for formation of surface sediment runoff in the urban environment in spring: water accumulated in the snow cover during the cold period of the year, characteristics of the thermal regime during snowmelt (duration, cold returns), precipitation and soil thawing intensity during the snowmelt. The results obtained can be used in planning the measures to improve the environmental situation in the urban areas. © 2020 Tomsk Polytechnic University, Publishing House. All rights reserved. The research was carried out on account of grant of Russian Scientific Foundation (project no. 18-77-10024).

Актуальность исследования. Информация о составе, льдистости и геохимических особенностях мерзлых пород необходима при освоении нефтегазоконденсатных месторождений Ямала, Гыдана и Таймыра. Среди факторов, определяющих экологию тундровых ландшафтов криолитозоны, большое значение имеют подземные льды, в том числе полигонально-жильные, и последствия их вытаивания. Гидрохимический состав и содержание редкоземельных элементов в сингенетических жилах фиксируют информацию об источниках влаги и условиях, при которых происходило их формирование. Соотношение основных ионов и распределение редкоземельных элементов в растворе может быть использовано для оценки влияния на состав льда атмосферных осадков, морских и вулканических аэрозолей, антропогенного загрязнения. Цель: выявить источники поступления химических элементов и оценить влияние типа льдовыделения на гидрохимический состав и распределение редкоземельных элементов в различных генетических типах льда - полигонально-жильном, морском, озерном и фирновом льдах. Объекты: полигонально-жильный лед, вмещающие его отложения, сезонные льды, поверхностные воды, отобранные в экспедициях ИКЗ ТюмНЦ СО РАН в 2009-2014 гг. Методы исследования химического состава: масс-спектрометрия с индуктивно связанной плазмой, атомно-абсорбционная спектрометрия, эмиссионная фотометрия, хроматография. Результаты. Установлено, что на химический состав полигонально-жильных льдов, изученных в прибрежной зоне ключевых участков о. Белый, о. Сибирякова, Западного Ямала и Западного Таймыра, имели влияние морские и континентальные аэрозоли. Сингенетические полигонально-жильные льды, пресные и ультрапресные по минерализации, сформированы при промерзании талых вод, которые содержат сорбированные снегом морские аэрозоли - взвешенные в атмосфере твердые и жидкие частицы. Полигонально-жильные льды в удаленном от моря районе оз. Сохонто не имеют признаков морского влияния по соотношению основных ионов. Полигонально-жильные льды с минеральными включениями формировались не только за счет талых снеговых вод с аэрозолями континентального происхождения, но и за счет надмерзлотных вод. В полигонально-жильных льдах выявлено увеличение содержаний лантаноидов в водорастворимой форме по сравнению с кларковыми значениями и современными поверхностными льдами. По цериевой аномалии в большинстве изученных сингенетических ледяных жил подтверждается участие морских аэрозолей. По распределениям редкоземельных элементов выявлено характерное для полигонально-жильных льдов соотношение легких и тяжелых редкоземельных элементов равное 0,9, и соотношение лантана к остальным лантаноидам, равное 0,2. Морской лед наследует минерализацию и состав морской воды. Озерный лед различается по глубине и отражает сезонное изменение гидрохимического состава при ледоставе и повышение концентрации морских аэрозолей в снеге, перекрывающем озерный лед. Фирновый лед полярного Урала имеет очень низкую минерализацию, в нем отсутствуют примеси морского аэрозоля. В полигонально-жильных льдах голоценового и неоплейстоценового возраста реализован природный механизм накопления редкоземельных элементов в водорастворимой форме в комплексе с железом, торием и иттрием. Вытаивание ледяных жил может приводить к поступлению редкоземельных элементов в поверхностные воды. Relevance of the research. Information on composition, ice content and geochemical characteristics of frozen rocks is necessary for exploration of oil and gas condensate fields of Yamal, Gydan and Taimyr. Among the factors determining the tundra landscapes ecology of the cryolithozone, underground ice and their melting have great importance. The hydrochemical composition and rare-earth elements content in syngenetic ice wedge retain the information on the moisture sources and conditions of their formation. The main ions correlation and rare-earth elements distribution in the ice composition can be used to estimate the influence of such natural factors as precipitation, sea and volcanic aerosols and anthropogenic pollution. The main aim of the research is to identify chemical elements sources and to assess the impact of the ice type on hydrochemical composition and rare-earth elements distribution in different genetic types of ice - wedge, seasonal and firn ice. Objects: ice wedge, sediments rocks, seasonal ice, surface water, taken in expeditions Earth Cryosphere Institute, Tyumen scientific centre SB RAS in 2009-2014. Methods of chemical research: inductively coupled plasma mass spectrometry, atomic absorption spectrometry, emission photometry, chromatography. Results. It is established that marine and continental aerosols influenced the chemical composition of ice wedge studied in the coastal zone of the key areas of Belyj island, Sibiryakova island, Western Yamal and Western Taimyr. Fresh and ultrafresh syngenetic ice wedge is formed by freezing melt water, which contains snow-sorbed sea aerosols - suspended in the atmosphere solid and liquid particles. Ice wedge in the lake Sokhonto area long-distanced from the sea has no signs of marine influence according to the main ions content. Ice wedge with mineral inclusions was formed not only due to snow melt water with aerosols of continental origin, but also due to the suprapermafrost water. It was found out that lanthanide content in water-soluble form has increased in comparison with both сlark values and the content in the modern surface ice. In the most of examined syngenetic ice wedge the participation of marine aerosols is confirmed taking into account the cerium anomaly. Moreover according to the distribution of rare-earth elements the correlation between light and heavy rare-earth elements typical for ice wedge, equal to 0,9, and correlation between lanthanum and the other lanthanides, equal to 0,2, are observed. Sea ice inherits the mineralization and composition of sea water. Lake ice varies in depth and reflects seasonal changes in hydrochemical composition of ice and increases in concentration of marine aerosols in the snow covering the lake ice. Firn ice of the polar Urals has a very low mineralization, there are no impurities of sea aerosol. The natural mechanism of rare earth elements accumulation in water-soluble form in combination with iron, thorium and yttrium is implemented in ice wedge of the Holocene and Neopleistocene. Melting out ice wedge may lead to the flow of rare-earth elements in the surface water.

In recent years, ground-penetrating radars are widely used for measuring thickness and liquid water content in snow cover on land and glaciers. The measurement accuracy depends on radio wave velocity (RWV) adopted for calculations. The RWV depends mainly on density, water content and structure of the snow cover and ice layers in it. The density and wetness of snow, and its structure can be estimated from data on RWV, using the available experimental and theoretical relations. Satisfactory results can be obtained using the Looyenga’s (1965) equations to estimate the density and wetness of snow cover, and equations of van Beek’s (1967) showing the distinction between RWV speeds velocities in snow cover and ice layers with different prevailing orientation and sizes of air or water inclusions. RWV in dry snow with density 300 kg/m3 may vary by 32 m/µs, depending on whether the vertical or horizontal orientation of the air inclusions prevails therein. In ice with density 700 kg/m3 effect of air inclusions orientation on differences in RWV is reduced to 5 m/µs. If the inclusions are not filled with air but with water, the difference in RWV in snow is 21 m/µs, and in ice is 24 m/µs. The RWV is affected not only by orientation of the inclusions, but their elongation. Twofold elongation of ellipsoidal air and water inclusions increases the difference in RWV in snow (with a density 300 kg/m3 ) to 23 m/µs and 22 m/µs. These estimates show a noticeable influence of snow structure on RWV in snow cover. The reliability of the above RWV estimates depends significantly on a thermal state of the snow cover, and decreases during snowmelt and increases in the cold period. It strongly depends on accuracy of measurements of the RWV in snow cover and its separate layers. With sufficiently high accuracy of the measurements this makes possible to detect and identify loose layers of deep hoar and compact layers of infiltration and superimposed ice, which is important for studying the liquid water storage of snow cover and a glacier mass balance. Therefore, considerable attention should be given to accuracy of the RWV measurements in dry and wet snow cover and its individual layers. With sufficiently high accuracy of measurements of the RWV, this should allow revealing such layers and estimating their thickness and average density.

Application of the stable isotope method in the balance equations used to calculate separation of the runoff hydrograph from the Djankuat Glacier basin is demonstrated. Simultaneous solution of equations of water, isotope and ion balances is applied to estimate contributions of different components and processes to formation of the Djankuat River runoff regime. For June 2014, we made calculations for the purpose to separate contributions of the spring (isotopically weighted) snow and winter (isotopically depleted) snow. Field works in the glacial basin Djankuat were performed during two ablation seasons, i.e. from June to September of 2013 and 2014. Two approaches were used when calculating separation of the runoff hydrograph by means of solution of systems of equations for isotopic and ion balances: 1) taking account of the isotope fractionation during snow melting, and 2) with no account for the fractionation. Separation of the hydrograph for June 2014 have shown that about 15–20% of the Djankuat River runoff is formed by spring snow melting, sometimes increasing up to 36%. Contribution of spring meltwater to the total runoff increases when the isotope fractionation during the snow melting is taken into account for the calculations. In this case, the contribution of spring snow changes from 30 to 50%.

Рассматриваются многолетние изменения элементов водного баланса реки Альдегонда. На основе модельных расчетов восстановлены гидрографы стока для реки Альдегонда за весь период гидрологического цикла от начала таяния снега до полного осеннего перемерзания реки с 2005 по 2016 гг. Анализ рядов показывает, что сток реки Альдегонда хорошо реагирует на многолетние климатические перемены, происходящие в последнее десятилетие на арх. Шпицберген., Longterm changes of elements of water balance of Aldegonda river are considered. Flow hydrographs for Aldegonda river were restored for the entire period of the hydrological cycle from the beginning of snow melting to the full autumn freezing of the river from 2005 to 2016, on the basis of model calculations. An analysis was carried out on the rows, which showed that the flow of Aldegonda river responds well to the longterm climatic changes occurring in Spitsbergen in the last decade., №3 (2019)