Dependence of the pour point of diesel fuels on the properties of the initial components

An analytical expression is obtained for the dependence of the pour point of diesel fuels on the pour point and weight relationship of the initial components. For determining the pour point of a multicomponent fuel mixture, it is assumed that the mixture of two components has the pour point of a separate equivalent component, then calculating the pour point of this equivalent component mixed with a third component, etc

ОЦЕНКА ДИНАМИЧЕСКИХ ХАРАКТЕРИСТИК СЕЛЕВОГО ПОТОКА ПО ВИДЕОМАТЕРИАЛАМ

For mud dams construction it is necessary to clarify characteristics of debris flow such as flow velocity and pressure on the barrier. Determining these characteristics often causes difficulties due to the fact that debris flow is rather rare event and constant monitoring of them is carried out at mud flow observation station stations, which are few worldwide. Currently large number of videos have appeared on the Internet that captures debris flow descent. This material can be used to obtain not only qualitative, but also quantitative characteristics of the debris flow. In cases, when it is possible to determine the scale and specific location of debris flow on a video, measuring its velocity and other characteristics is a workable task. This research present an attempt to quantify the debris flow velocity based on the video materials with the subsequent comparison of the results obtained using various methods. The object of our study was the debris flow that came down in Austria, in Firgen on August 4, 2012. The survey was carried out from several angles, which made it possible to select a section of the channel to measure the velocity of debris flow wave train. Calculation of flow velocity and pressure on the barrier was conducted by several methods developed by various researchers. Debris flow velocities measured on the video are minimum – 7,4 m/s, maximum - 10 m/s. Differences between calculated by various methods and measured on the video values range from 0,1 m/s to 4,8 m/s.Для проектирования сооружений противоселевой защиты необходимо знать значения таких характеристик селя, как скорость потока и давление селевой массы на преграду. Определение этих характеристик часто вызывает трудности из-за того, что сель – достаточно редкое событие и постоянные наблюдения за ними ведутся на селестоковых станциях, которых во всем мире немного. В настоящее время в интернете появилось большое количество видеосъемок, на которых запечатлен сход селевого потока. Такой материал можно использовать для получения не только качественных, но и количественных характеристик селевого потока. В тех случаях, когда имеется возможность определить на видео масштаб и конкретное место схода селя, определение его скорости и других характеристик составляет выполнимую задачу. В статье представлена попытка количественной оценки скорости селевого потока по материалам видеосъемки с последующим сравнением полученных результатов со значениями, рассчитанными по различным методикам. В качестве объекта нашего исследования был выбран селевой поток, сошедший в Австрии, г. Фирген 4 августа 2012 года. Съемка производилась с нескольких ракурсов, что позволило выбрать участок канала, на котором оказалось возможным произвести измерение скорости движения серии селевых волн. Расчет скорости селевого потока и давления на препятствие производился по методикам разных исследователей. Измеренные на видеоролике скорости селевых волн на разных участках составили: минимальная – 7,4 м/с, максимальная – 10 м/с. Различия между рассчитанными по разным методикам и измеренными по видео значениями составляют от 0,1 м/с до 4,8 м/с. Кроме этого, были проведены расчеты расхода селевого потока и плотности селевой массы. Нами использовалась модель транспортно-сдвигового селевого процесса, разработанная Ю.Б. Виноградовым. При сравнении полученных значений с результатами австрийских коллег было выявлено, что значения характеристик похожи, но разброс значений по данной модели меньше.   Литература Виноградов Ю.Б. Этюды о селевых потоках. Л.: Гидрометеоиздат, 1980. 144 с. Голубцов В.В. О гидравлическом сопротивлении и формуле для расчета средней скорости течения горных рек // Труды КазНИГМИ. 1969. Вып. 33. С. 30-41. Гонор А.Л., Пик-Пичак Е.Г. Численное моделирование удара снежной лавины по твердой стенке // Известия Академии наук СССР. Механика жидкости и газа. 1983. № 6. С. 86–91. Казаков Н.А. Волновая динамика селей // Геоэкология. Инженерная геология. Гидрогеология. Геокриология. 2001. № 2. С. 158-164. Молжигитов С.К. Оценка ударной нагрузки селевого потока на поперечную жесткую преграду // Международный журнал прикладных и фундаментальных исследований. 2016. № 3 (часть 1). С. 16-20. Срибный М.Ф. Формула средней скорости течения рек и их гидравлическая классификация по сопротивлению движению // Исследования и комплексное использование водных ресурсов. М.: Изд-во АН СССР, 1960. С. 204-220. Aulitzky Н. The debris flows of Austria // Bulletin of the International Association of Engineering Geology (Bulletin de l'Association Internationale de Géologie de l'Ingénieur). 1989. Volume 40. Issue 1. P. 5–13. DOI: 10.1007/BF02590338 Hübl J. Ereignisdokumentation, Band 3: Jahresrückblick der Ereignisse. IAN Report 150. Wien, Februar 2013, 88 p. Виноградова Т.А., Виноградов А.Ю. Экспериментальные селевые потоки в бассейне р. Чемолган // Природные опасности. 2017. Том. 88. Доп. 1. пп. 189-198. DOI: 10.1007 / s11069-017-2853-

Historical and recent aufeis in the Indigirka River basin (Russia)

A detailed spatial geodatabase of aufeis (or naled in Russian) within the Indigirka River watershed (305&thinsp;000&thinsp;km2), Russia, was compiled from historical Russian publications (year 1958), topographic maps (years 1970–1980s) and Landsat images (year 2013–2017). Identification of aufeis by late spring Landsat images was performed with a semi-automated approach according to Normalized Difference Snow Index (NDSI) and additional data. After this, a cross-reference index was set for each aufeis field to link and compare historical and satellite-based aufeis datasets. The aufeis coverage varies from 0.26&thinsp;% to 1.15&thinsp;% in different sub-basins within the Indigirka River watershed. The digitized historical archive (Cadastre, 1958) contains the coordinates and characteristics of 896 aufeis fields with a total area of 2064&thinsp;km2. The Landsat-based dataset included 1213 aufeis fields with a total area of 1287&thinsp;km2. Accordingly, the satellite-derived total aufeis area is 1.6 times less than the Cadastre (1958) dataset. However, more than 600 aufeis fields identified from Landsat images are missing in the Cadastre (1958) archive. It is therefore possible that the conditions for aufeis formation may have changed from the mid-20th century to the present. Most present and historical aufeis fields are located in the elevation band of 1000–1200&thinsp;m. About 60&thinsp;% of the total aufeis area is represented by just 10&thinsp;% of the largest aufeis fields. Interannual variability of aufeis area for the period of 2001–2016 was assessed for the Bolshaya Momskaya aufeis and for a group of large aufeis fields (11 aufeis fields with areas from 5 to 70&thinsp;km2) in the basin of the Syuryuktyakh River. The results of this analysis indicate a tendency towards an area decrease in the Bolshaya Momskaya aufeis in recent years, while no reduction in Syuryuktyakh River aufeis area was observed. The combined digital database of the aufeis is available at https://doi.org/10.1594/PANGAEA.891036.</p

Наледи бассейна р. Индигирка по современным снимкам Landsat и историческим данным

The paper presents methods and results of creation of the digital catalogue of aufeises for the Indigirka river basin made on the basis of Landsat images and historical data. The region under study is the basin before the hydrometric section of GMS Vorontsovo, its area is about 305 000 km2. Historical data were taken from the Inventory of naleds of the North-East of the USSR territory published in 1958 and topographic maps. It includes the estimated coordinates and characteristics of 897 aufeises with total area of 2064 km2. The Landsatbased identification of aufeises for 2013–2017 allowed making description of 1213 aufeises over a total area of 1287 km2. The integrated digital catalogue of the aufeises for the Indigirka river basin based on combination of the above two sources is available at https://issues.pangaea.de/browse/PDI-17699. 10% of the largest aufeises make up about 60% of the total area of all aufeises according to both sources. The largest number of aufeises is at altitudes of 900–1300 m. The interannual variability of area of the aufeises for the period 2001-2016 was estimated by the example of the Bolshaya Momskaya naled and the group of large aufeises in the basin of the Syuryukty River which is the left tributary of the Indigirka. The conclusions cannot be considered unambiguous due to certain limitations of the imagery data but the results of the analysis is indicative of a tendency to decreasing in the area of the Bolshaya Momskaya naled in recent years, while no reduction in the aufeis area is noted in the basin of the Syuryukty River. The main results of this work are the new geodatabase of the aufeises in the Indigirka river basin, and also the comparison of the satellite observations with historical data performed for two major naleds. It is established that the satellite-estimated total area of aufeises is 1.6 times less than in the Cadastre (1958). At the same time, it was found that more than 600 aufeises recognized by the Landsat images were absent in the Cadastre of 1958. This may suggest that either the Cadastre data is incomplete or that conditions of the aufeis can be significantly changed over the past 50 years.На основе Кадастра наледей Северо-Востока СССР (1958 г.) и топографических карт создана база данных о 897 наледях в бассейне р. Индигирка. По данным космической съёмки Landsat за 2013– 2017 гг. выявлены 1213 наледей суммарной площадью 1287 км2. Создан единый электронный Каталог наледей в бассейне р. Индигирка. Современная площадь наледей здесь в 1,6 раза меньше, чем по данным Кадастра 1958 г., но в Кадастре отсутствуют сведения более чем о 600 наледей, обнаруженных по снимкам.

Многолетняя динамика гигантской Анмангындинской наледи на Северо-Востоке России (1962–2021 гг.)

The huge Anmangynda aufeis is located in the valley of the river of the same name in the Magadan region in North-East of Russia. This is the only in the world aufeis site with a 30-years period of ground-based observations (1962–1991). The materials of these observations were supplemented with data obtained from the analysis of Landsat and Sentinel satellite images for the period 2000–2021, as well as the results of field investigations carried out in 2020–2021. The long-term variability of the maximum area, volume and average thickness of ice, the dynamics of formation and destruction of the aufeis ice in the cold and warm periods of the year were analyzed. It was found that the maximum values of the area and volume of ice on the dates before the start of ablation decreased by 25 and 33%, respectively. In 2000–2021, the average values of the aufeis characteristics are estimated as 4.7 km2 and 7.1 million m3, while in 1962–1991 – 5.5 km2 and 8.5 million m3. The analysis of the intra-annual dynamics revealed that the Anmangynda aufeis being earlier the perennial formation has transformed to the seasonal one. Further researches of the Anmangynda aufeis will make possible to assess the influence of various factors, including climatic ones, on the processes of an aufeis formation and to forecast their changes in the future for the cryolitic zone of the North-East of our country.Приводятся материалы о многолетней и сезонной изменчивости морфометрических характеристик гигантской наледи в долине реки Анмангында на Северо-Востоке России. Показано, что за последние 60 лет максимальная площадь тарына сократилась на 25%, а объём на 33%. Период абляции ледяного массива уменьшился на 34 дня, наледь из разряда перелетовывающей перешла в категорию сезонных образований

Геофизические признаки источников гигантской наледи на р. Анмангында (Магаданская область)

Giant aufeis fields are the indicators of water exchange processes in the permafrost zone. The study of aufeis dynamics is relevant to assessing the state of the cryosphere in a changing climate. The Anmangynda aufeis which forms upstream of the Kolyma River basin, was as large as 6.8 km2 in the last century and is considered representative of the mountainous territories in the northeast Russia. In recent decades, there have been significant changes in the aufeis formation regime that require updating the understanding of the cryosphere processes. The historical observational data obtained in 1962-1990 for the Anmangynda aufeis allows using it as the present-day object of research.The main goal of geophysical research in 2021-2022 was to study the structure of the Anmangynda aufeis and aufeis glade to determine its genesis and development processes. The main tasks were to identify the boundary between frozen and unfrozen rocks, to reveal groundwater discharge channels, and to assess the aufeis thickness distribution. There were carried out georadar survey using an antenna unit with central frequency of 250 MHz and ground-based capacitively coupled electrical resistivity tomography. It was found that by April 5, 2021, the maximum ice thickness was 4.35 m with an average value of 1.35 m, and the volume of aufeis was 3.56 million m3. By means of georadar, there were performed identification and drilling verification of the groundwater discharge channels from alluvium to aufeis surface, located in the stream beds. There is geophysical evidence of deep bedrock groundwater sources. Based on the electrical resistivity tomography data, there were identified large and locally freezing river taliks, from which the water is squeezed onto the ice surface. It is recommended to conduct further interdisciplinary research to clarify the geophysical results obtained.Гигантские наледи являются индикаторами процессов водообмена в зоне распространения мерзлоты. Исследование динамики наледей является актуальной задачей оценки состояния криосферы в изменяющемся климате. Анмангындинская наледь, формирующаяся в верховьях бассейна р. Колымы, в прошлом веке достигала размеров 6.8 км2 и считается репрезентативной для горных территорий северо-востока России. В последние десятилетия произошли значительные изменения режима наледеобразования, требующие актуализации представлений о процессах криолитозоны. Наличие исторических данных наблюдений на Анмангындинской наледи позволяет использовать ее как объект исследований в настоящее время.Целью геофизических исследований 2021-2022 гг. являлось изучение строения Анмангындинской наледи и наледной поляны для уточнения ее генезиса и процессов формирования. Основными задачами были выявление границ мерзлых и талых пород, каналов разгрузки подземных вод и оценка распределения толщины наледного льда. Проведены георадиолокационные зондирования с антенным блоком центральной частоты 250 МГц и электротомография с заземлениями через емкостную связь. Установлено, что к 5 апреля 2021 г. максимальная толщина льда составила 4.35 м при среднем значении 1.35 м, объем наледи - 3.56 млн м3. С помощью георадара выявлены и заверены бурением каналы разгрузки подземных вод из аллювия под лед, расположенные в руслах проток. Выявлены геофизические признаки глубинных источников подземных вод в коренных породах. По данным электротомографии установлено наличие крупных и локальных промерзающих подрусловых таликов, из которых выжимается вода на поверхность льда

Icings of the Indigirka river basin according to the recent Landsat satellite images and historical data

The paper presents methods and results of creation of the digital catalogue of aufeises for the Indigirka river basin made on the basis of Landsat images and historical data. The region under study is the basin before the hydrometric section of GMS Vorontsovo, its area is about 305 000 km2. Historical data were taken from the Inventory of naleds of the North-East of the USSR territory published in 1958 and topographic maps. It includes the estimated coordinates and characteristics of 897 aufeises with total area of 2064 km2. The Landsatbased identification of aufeises for 2013–2017 allowed making description of 1213 aufeises over a total area of 1287 km2. The integrated digital catalogue of the aufeises for the Indigirka river basin based on combination of the above two sources is available at https://issues.pangaea.de/browse/PDI-17699. 10% of the largest aufeises make up about 60% of the total area of all aufeises according to both sources. The largest number of aufeises is at altitudes of 900–1300 m. The interannual variability of area of the aufeises for the period 2001-2016 was estimated by the example of the Bolshaya Momskaya naled and the group of large aufeises in the basin of the Syuryukty River which is the left tributary of the Indigirka. The conclusions cannot be considered unambiguous due to certain limitations of the imagery data but the results of the analysis is indicative of a tendency to decreasing in the area of the Bolshaya Momskaya naled in recent years, while no reduction in the aufeis area is noted in the basin of the Syuryukty River. The main results of this work are the new geodatabase of the aufeises in the Indigirka river basin, and also the comparison of the satellite observations with historical data performed for two major naleds. It is established that the satellite-estimated total area of aufeises is 1.6 times less than in the Cadastre (1958). At the same time, it was found that more than 600 aufeises recognized by the Landsat images were absent in the Cadastre of 1958. This may suggest that either the Cadastre data is incomplete or that conditions of the aufeis can be significantly changed over the past 50 years

Challenges of hydrological engineering design in degrading permafrost environment of Russia

Abstract The study shows that the current network of hydrometeorological observation in the permafrost zone of Russia is insufficient to provide data for the statistical approaches adopted at the state level for engineering surveys and calculations. The alternative to the financially costly and practically impossible expansion of the monitoring network is the development of hydrological research stations and the implementation of new methods for calculating streamflow characteristics based on mathematical modeling. The data of the Kolyma Water-Balance Station, the first research basin in the world in a permafrost environment (1948–1997), and the process-based hydrological model Hydrograph are applied to simulate streamflow hydrographs in remote mountainous permafrost basins. The satisfactory results confirm that mathematical modeling may substitute or replace statistical approaches in the conditions of extreme data insufficiency. The improvement of the models in a changing climate requires the renewal of historical observations at currently abandoned research stations in Russian permafrost regions. The study is important for forming the state policy in climate change adaptation and mitigation measures