Ob River Research Articles

Impacts of anthropogenic water regulation on global riverine dissolved organic carbon transport

Abstract. Anthropogenic water regulation activities, including reservoir interception, surface water withdrawal, and groundwater extraction, alter riverine hydrologic processes and affect dissolved organic carbon (DOC) export from land to rivers and oceans. In this study, schemes describing soil DOC leaching, riverine DOC transport, and anthropogenic water regulation were developed and incorporated into the Community Land Model 5.0 (CLM5.0) and the River Transport Model (RTM). Three simulations by the developed model were conducted on a global scale from 1981–2013 to investigate the impacts of anthropogenic water regulation on riverine DOC transport. The validation results showed that DOC exports simulated by the developed model were in good agreement with global river observations. The simulations showed that DOC transport in most rivers was mainly influenced by reservoir interception and surface water withdrawal, especially in central North America and eastern China. Four major rivers, including the Danube, Yangtze, Mississippi, and Ganges rivers, have experienced reduced riverine DOC flows due to intense water management, with the largest effect occurring in winter and early spring. In the Danube and Yangtze river basins, the impact in 2013 was 4 to 5 times greater than in 1981, with a retention efficiency of over 50 %. The Ob river basin was almost unaffected. The total impact of anthropogenic water regulation reduced global annual riverine DOC exports to the ocean by approximately 13.36 ± 2.45 Tg C yr−1, and this effect increased from 4.83 % to 6.20 % during 1981–2013, particularly in the Pacific and Atlantic oceans.

Работа отдела профилактической дезинфекции ФБУЗ "Центр гигиены и эпидемиологии в Алтайском крае" по ликвидации последствий наводнения 2014 года на территории Алтайского края

In May 2014, the weather in the Altai Republic was very hot (plus 30–35 °C), snow and glaciers were melting rapidly in the mountains. On May 27, rains began in the Altai Mountains and continued until May 30. During these three days, 117–185 percents of the monthly norm of precipitation fell. As a result, water levels in the Katun, Biya, Aley, and Ob rivers exceeded critical values and adjacent territories were flooded. During the flooding 128 settlements in 25 municipalities, 16053 houses with a population of 43619 people were flooded. Also, 91 social facilities and 4 cattle burial grounds were flooded. In connection with the emergency situation in the region caused by the flood, in order to prevent possible adverse consequences for the health of the population of the region, the Center of Hygiene and Epidemiology in the Altai region organized and carried out the necessary amount of sanitary and epidemiological measures (disinfection, deratization and disinsection) in the territories out of the flood zone. Keywords: treatment act, barrier deratization, disinfection teams, disinfectants, disinfection treatments, focal deratization, preventive measures, emergency.

Small Organisms in a Large River: What Provides the High Diversity of Scaled Chrysophytes in the Ob River?

Currents are one of the main factors favoring the dispersal of microscopic planktic organisms over inland lakes and rivers. Large rivers of the northern hemisphere, flowing from south to north, can increase the diversity of northern latitudes with boreal species, while high water levels and floods expand the range of ecotopes and the biodiversity of rivers. We studied the distribution of the taxonomic structure and species richness of scaled chrysophytes downstream of the Ob river—a large river in West Siberia—at the end of the high-water period (June). Methods of scanning and transmission microscopy allowed the determination of a high taxonomic richness of these organisms, 67 species in total. The species were unevenly distributed by stations, with the maximum number of species (54) occurring in a shallow still bay without current and with minimum turbidity and a small number of diatoms. The species diversity in the main current was represented mainly by ubiquitous and cosmopolitan species.Water level fall usually coincides with the end of the vegetation of many scaled chrysophytes and the formation of stomatocysts. The stomatocysts of different species may drift downstream and then germinate when they find suitable conditions at theappropriatetime. Large rivers that are subject to significant changes in water level during their hydrologicalperiodsare able to host ahigh diversity of microscopic planktic organisms. Studying this capacity may reinforce the hypothesis of an omnipresence, i.e., that “everything is everywhere”.

Methane in West Siberia terrestrial seeps: Origin, transport, and metabolic pathways of production.

The expansive plains of West Siberia contain globally significant carbon stocks, with Earth's most extensive peatland complex overlying the world's largest-known hydrocarbon basin. Numerous terrestrial methane seeps have recently been discovered on this landscape, located along the floodplains of the Ob and Irtysh Rivers in hotspots covering more than 2500 km2 . We articulated three hypotheses to explain the origin and migration pathways of methane within these seeps: (H1) uplift of Cretaceous-aged methane from deep petroleum reservoirs along faults and fractures, (H2) release of Oligocene-aged methane capped or trapped by degrading permafrost, and (H3) horizontal migration of Holocene-aged methane from surrounding peatlands. We tested these hypotheses using a range of geochemical tools on gas and water samples extracted from seeps, peatlands, and aquifers across the 120,000 km2 study area. Seep-gas composition, radiocarbon age, and stable isotope fingerprints favor the peatland hypothesis of seep-methane origin (H3). Organic matter in raised bogs is the primary source of seep methane, but observed variability in stable isotope composition and concentration suggest production in two divergent biogeochemical settings that support distinct metabolic pathways of methanogenesis. Comparison of these parameters in raised bogs and seeps indicates that the first is bogs, via CO2 reduction methanogenesis. The second setting is likely groundwater, where dissolved organic carbon from bogs is degraded via chemolithotrophic acetogenesis followed by acetate fermentation methanogenesis. Our findings highlight the importance of methane lateral migration in West Siberia's bog-dominated landscapes via intimate groundwater connections. The same phenomenon could occur in similar landscapes across the boreal-taiga biome, thereby making groundwater-fed rivers and springs potent methane sources.

The Mechanism and Regularities of Ion Runoff Formation in the Ob River (Western Siberia) under the Influence of Its Tributaries and Underground Feeding

An analysis of observation data was conducted on the chemical composition of river and groundwater in the Ob River basin, covering more than 23 thousand samples taken from the network of governmental monitoring of surface and groundwater, the materials of scientific research, and engineering surveys. A model was developed for computing the total content of major ions along a stem of the Ob River. As a result, quantitative estimates of the total ion runoff and its underground component were obtained. Conclusions were drawn relating to: (1) uneven distribution of the ion flow over the Ob basin; (2) the predominant removal of dissolved solids from mountain regions and adjacent forest steppe and southern taiga areas and their accumulation in the middle taiga subzone with the maximum thickness of sedimentary cover of Mesozoic–Cenozoic deposits; (3) the influence of the main tributaries on the total dissolved solids (TDS) in the Ob River, limited to only a few kilometers downstream of their mouths (the rivers of Irtysh, Chumysh, and Severnaya Sosva as exceptions); (4) the maximum impact of groundwater on river water TDS in the forest steppe and southern taiga areas of the upper and middle Ob basin and minimum impact in the flat part of the lower reaches of the Ob in forest–tundra and tundra.

Влияние колебаний стока Оби и Енисея на площадь ледяного покрова Карского моря

The paper considers the dependence of changes in the area of ice in the Kara Sea with fluctuations of the Ob and Yenisei rivers runoff during the period from 1978 to 2022. Over the period from 2004 to 2022, statistically significant positive correlations between the summary runoff of the Ob and Yenisei and the area of ice in the Kara Sea were found. There was an acceleration of ice formation processes, an elongation of the ice stabilization period, the beginning of ice melting in a later date and a higher resistance of ice to destruction during summer in the high-water content years of the Ob and Yenisei rivers.

The Neolithic and Early Metal complexes of the Chepkul 5 settlement in the North of the An-dreevskaya Lake System

The problems of development of the early Neolithic and Early Metal Age complexes in the Tobol-Ishim interfluve are still insufficiently studied. A certain understanding of the cultural and historical processes that took place during these periods can be based on the materials of the multi-layered settlement of Chepkul 5, located on the territory of the Andreevskaya lake system near the city of Tyumen. The purpose of this work is to introduce into scientific discourse the research materials of the early Neolithic and Bayryk Culture complexes. Within the Neolithic pottery complex of Chepkul 5, it is possible to conditionally distinguish groups of vessels comparable to the ware of the Boborykino, Koshkino, Basyanovo and comb types, which find similarities in the vast territory from the eastern slopes of the Urals to the Baraba forest-steppe, and from the Lower Ob River to the steppes of Kazakhstan. Stone tools of such complexes, including Chepkul 5, contain points with high steep retouch, oblique points on blades, and geometric microliths. The presence of lips (overhangs) on the rims on the inside of the vessels, and certain other characteristics of ceramics, bring the analysed complex closer to the ware of the Boborykino Culture of the Yurtobor 3 settlement [Zakh, 1995]. Considering the date from charcoal from the settlement of Yurtobor 3 — 6591–6478 cal BC (UPI-559) [Zakh, 1995, 2009] — the time of existence of the settlement Chepkul 5 in the early Neolithic can be correlated with the end of the humid stage and the beginning of the dry period (8.2–5.5 cal ka BP) [Zach, 2021]. According to the location of the pits in the trench of the Early Metal Period dwelling 2 of Chepkul 5, which contained pottery with comb-pit and large-stroke ornamentation, the building can be reconstructed as a semi-dugout with a pillar-frame structure, with an area of about 40 m2. Similar structures, ware, stone and clay sinkers and other items belong to the Bayryk Culture, are dated to the 3rd mil. BC and can be considered together with the Ishim complexes of the Alexandrovo stage of the Ekaterinino Cultures within the comb-pit community of the 3rd mil. BC. However, the complexes of the Tobol and Ishim regions belong to different cultures, as evidenced by the complete absence of clay sinkers in the Ishim region and in the territories to the east. The presence of the latter, as well as drawings on dishes and petroglyphs in the Early Metal Period cultures of Trans-Urals, suggests that the population of the Tobol region was engaged in drive hunting for waterfowl during molting [Zakh, 2022], which could not but affect its cultural specificity.

Study of the Features of Natural Mortality in Muksun and Peled from the Ob River by Constructing the Dependences of Loss of the Abundance of Their Generations

Study of the Features of Natural Mortality in Muksun and Peled from the Ob River by Constructing the Dependences of Loss of the Abundance of Their Generations

Impact of Snowmelt Conditions on the Isotopic Composition of the Surface Waters of the Upper Ob River during the Flood Period

For many of the Siberian rivers, and the Upper Ob in particular, 70–80% of the volume of the annual water runoff is formed during the spring flood. Thus, factors influencing the formation of water runoff during the spring flood are paramount. We explain changes in the isotopic composition of the Upper Ob surface waters by changing different components’ contribution to the runoff water discharge over the spring flood period. We suggest estimating the time of meltwater flow from the Upper Ob watershed to the outlet section using the difference between the date of the complete melting of the snow cover in the catchment area and the date of the maximum light isotope composition of water in the outlet section. We show that a sharp short-term weighting of the isotopic composition of water in the river at the end of the first phase of the flood may be associated with the influx of autumn soil moisture, displaced from the soils by snowmelt waters.

DEVELOPMENT OF A SPECIALIZED SOFTWARE PACKAGE FOR NETWORK FORECAST OF FLOOD WATERS

Link for citation: Syryamkin V.I., Ivanenko B.P., Klestov S.A., Khilchuk M.D. Development of a specialized software package for neural network forecast of flood waters. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 5, рр.205-216. In Rus. The relevance of the study is caused by the need to develop modern methods of operational monitoring of the condition of territories due to the presence of various kinds of natural phenomena, in particular, floods and flood inundations. A lot of attention is paid to solving this problem by States, regions, municipalities and settlements. Purpose: development of a specialized software package designed to solve problems of short-term and medium-term flood water level forecasting based on operational data from hydrological observations with a minimum set of input data and with the ability to work with aerospace observation data. Objects: the area where the Tom and Ob rivers merge and downstream of the Ob river at the locations of hydrological posts: villages Pobeda, Nikolskoye, Molchanovo. Methods: neural network information modeling. Results. The paper considers the method of creating a neural network simulator designed for processing the results of hydrological measurements and solving a wide range of practical problems, including prognostic ones. An original method of constructing training samples was developed, which allows obtaining results with a minimum set of initial data. The authors investigated the efficiency and accuracy characteristics of neural network algorithms in solving the problem of forecasting the flood water level in the period from April 1 to June 30, 2011–2017.

Features of the Technology of Ceramics of the Atlym Culture (Based on the Materials of Settlements of Barsova Gora)

Purpose. Barsova Gora is a unique archaeological and landscape site located in the Tyumen Region (West Siberia) of the Russian Federation. A technical and technological analysis of ceramics of the Atlym culture from Barsova Gora I/40 (13 vessels), Barsova Gora I/22a (7 vessels) and Barsova Gora IV/4 (9 vessels) settlements was carried out.Results. It was found that for the pottery manufacture potters of the Atlym culture mainly selected ferruginous clays, varying in the degree of sandiness and the presence of natural inclusions of shells and vegetation fragments. At all sites, potters exploited several clay plots. Recipes and assortment of molding masses vary considerably from settlement to settlement. The most stable technology is typical for ceramics from the site Barsova Gora I/22a for which only one recipe (clay + chamotte) has been fixed. It testifies to homogeneity of pottery traditions that existed on this site. A similar trend is demonstrated by ceramics of the site Barsova Gora I/40, where uncalibrated chamotte was used as the main impurity. The pottery technology of these two sites is very similar, and, apparently, these settlements constituted one group of the Atlym population with similar skills. It is possible that representatives of this group could have participated in the genesis of the Krasnoozerskaya culture of the Ishim River basin, as they recorded significant similarities in the adaptive and constructive skills of pottery making. The opposite situation can be observed at the site of Barsova Gora IV/4, where six single and multi-component compositions have been identified, which indicates a mixture of pottery skills and techniques. Several different groups of potters may have lived at this site, using different assortments of impurities to compose the molding masses. Probably, the Barsova Gora IV/4 site was left by another group of the Atlym population with different pottery skills, which differ from the skills of the “Atlym” from Barsova Gora I/22a and I/40 settlements. It can be assumed that the Atlym population of Barsova Gora IV/4 came to Barsova Gora from other territories, possibly from the Lower Priirtysh.Conclusion. The pottery technology of the sites Barsova Gora I/40 and I/22a has no direct analogues in the previously studied complexes of the Atlym culture in Western Siberia. For the vessels manufacturing technology of the Atlym culture in the territories of the Lower Irtysh River basin, Baraba and the Lower Ob River basin, the dominance of reipes with chamotte is not characteristic. At the same time, the use of chamotte as the main mineral additive and organic solutions is typical for ceramics of the later Krasnoozerskaya culture, which may be based on the Atlym culture. Vessel manufacturing techniques are also similar. Ceramics of the Atlym culture from the Barsova Gora IV/4 site demonstrates the greatest technological similarity with the pottery from The Lower Irtysh River basin. Potters of these territories used a similar range of mineral additives. The surfaces of the vessels were smoothed with a hard, smooth tool. The difference is manifested in the vessels design.

New Estimate of the Supply of Dissolved Organic Carbon with the Waters of the Ob and Yenisei to the Kara Sea Basin

Calculations were made of the runoff of dissolved organic carbon (DOC) into the Kara Sea with the waters of the Ob and Yenisei rivers. The estimates performed showed that the DOC runoff with the Yenisei waters (3.67 × 106 tC/year) is less than the DOC runoff with the Ob waters (4.06 × 106 tC/year), which is due to differences in the structure of the drainage basins and estuaries of these rivers. All previous published estimates show the opposite. The lack of the DOC content data during the maximum flood of the Yenisei does not let us calculate accurately the DOC runoff with its waters, but makes it possible to estimate its maximum and minimum values (3.11–4.18 × 106 tC/year).

Study of the Features of Natural Mortality Iin Muksun and Peladi of the Ob River by Constructing Dependences of the Number of Their Generations

It is shown that it is possible to determine the natural mortality of fish, using the example of muksun (Coregonus muksun) and peled (Coregonus peled) of the Ob River, by constructing dependences of the decrease in the number of generations. It is established that the dynamics of mortality has a U-shaped form. The minimum mortality rates are at the age when sexual maturity reaches more than 70% of individuals. The influence of various natural and anthropogenic factors on natural mortality is shown. It is noted that periodically occurring deficiency of dissolved oxygen has a significant impact on the wintering fish in the southern part of the Gulf of Ob. There was an increase in mortality during fish migrations and this fact can serve as one of the criteria for the periodicity of whitefish spawning. It is established that numerous generations of favorable years of feeding and reproduction are characterized by a higher survival rate of individuals. The presence of genera-tions with different degrees of survival is an important adaptive property of populations.

Ключевые моменты интерпретации сейсмических данных внутри зон аномального разреза баженовской свиты на примерах Поточной, Спорышевской, Выинтойской и Ватинской зон.

The Bazhenovo horizon of Western Siberia has traditionally been one of the objects most studied by geologists and geophysicists in recent decades in Russia. However, along with the more familiar "classical" structure, there are areas where gray-colored inclusions of sandy-silty-clayey deposits are present between the carbonate-clayey-siliceous rocks of the Bazhenovo Black Shales Formation. Such sections geologists call "anomalous". The paper describes the application of the spectral decomposition method for detailing the structure of anomalous sections zones of the Bazhenovo Formation or in another words Giant Sand injection Complex (GSIC) of the Ob river region. Combining the results of dynamic interpretation of 3D seismic data with well logging data for a vast fund of exploration and production wells made it possible to build a seismogeological model of the of the Ob river region GSIC in the Potochnaya area. The clue approach was tested on the Sporyshevskaya and Vyyntoyskaya, Vatinskaya areas, which were much less explored by drilling. The listed zones were formed at different geological times, belong to different regional clinoforms, but have common patterns of structure, which is reflected in the seismogeological model of the Ob river region GSIC. The model describes the distal and proximal parts of the intrusion, which were formed in the Neocomian time, when gravity-driven flows of sandy-silty material injected and spread inside high-bituminous Jurasic Bazhenovo formation Black Shales. Within the proximal part gravity-driven flows were accompanied by slumps of more clayey rocks. The dimensions of these flows and slumps, their location over the area are shown, their mapping in the 3D seismic data is discussed. In this work, we managed to get closer to solving the problem of predicting the development of sandy downward intrusions. There are oil reservoirs in the Ob river region GSIC, but they are insufficiently studied.

Structure and Productivity of the Phytoplankton Community in the Southwestern Kara Sea in Early Summer

Knowledge of the features of the structure and productivity of the Arctic communities of marine planktonic algae is necessary to identify possible changes in the pelagic ecosystem functioning under the changing climate condition of the Kara Sea. This study shows that the species diversity, abundance of phytoplankton, and production activity of algae are at a maximum at the beginning of summer during a seasonal ice melting period. The studies were carried out in the southwestern Kara Sea and in the estuarine zone of the Ob and Yenisei rivers from 29 June to 15 July 2018. The concentrations of nutrients and dissolved organic carbon were determined. The optical properties of chromophoric dissolved organic matter, species composition, abundance and biomass of all size groups of phototrophic and heterotrophic phytoplankton, and parameters of primary production and potential photosynthetic capacity were considered. Statistical data analysis showed that the leading factors influencing changes in the abundance of phytoplankton and its productivity are the content of silicates and salinity. At the same time, the production potential of algae is realized as short-lived and small phytoplankton assemblages differed in number taxa and diversity, with an equally rapid decrease in photosynthetic activity. Such changes affect the Marine Zone to a greater extent and the Estuarine Zone to a lesser extent.

Optical signatures of dissolved organic matter in the Siberian Rivers during summer season

Rivers are the main way of mobilizing, transforming and transporting of dissolved organic carbon to the ocean, thus largely determining the features of the carbon cycle on the Arctic shelf and in the Arctic Ocean as a whole. Seasonal variations in dissolved organic matter (DOM) fluxes from land to sea have been well documented in the Siberian river’s deltas, yet remarkably little is known about how DOM varies with hydrograph within the rivers main stems. The distribution of DOM and its optical characteristics as well as the CO2 fluxes between river water and the atmosphere in the main channel and tributaries of Siberian rivers such as the Lena, the Ob and the Anadyr in summer (July) were studied. The aim of this study was to investigate spatial changes in dissolved organic carbon (DOC) concentrations and DOM composition based on its absorption properties along the riverine main stem, to compare the dynamics of DOC concentration and DOM properties in different Siberian rivers and to reveal the main factors determining its variability, to evaluate the relationship of DOM with carbonate chemistry of riverine waters. The observed spatial variability of the investigated parameters in the river channel was strongly influenced by the river hydrograph along with landscape and geographical features of its catchment area. The phase of river runoff differed significantly in the same time period in different river sections, thus largely determining the quantitative and qualitative variations in the composition of DOM. In the Ob River the inflow of water from its largest tributary, the Irtysh River, is also an important factor of spatial variations. During the summer low-flow period, less aromatic DOM was found in river waters; it was more photodegraded with a relatively low molecular weight of compounds, compared to the high-water period. Such dynamics is one of the factors that alter the carbonate chemistry of waters as well as the magnitude and direction of CO2 fluxes between river water and the atmosphere.Higher DOC concentrations and higher aromatic DOM were found in the Ob River waters compared to the waters of ‘permafrost’ rivers – the Lena and the Anadyr rivers, which was caused by higher soil organic carbon content and its greater availability determined by the state of permafrost located in the river’s watersheds. A strong correlation between DOC concentrations and the colored fraction of DOM was established, thus confirming the possibility of using the latter as a proxy of DOC concentrations in Siberian rivers. The unique information obtained on the properties and variability DOM, which enters the rivers in different flow phases along the main stem, allows a more accurate evaluation of the effect of changing climate on biogeochemical cycles in the Arctic.

ELITE BURIALS OF THE BEGINNING OF THE IRON AGE IN THE SURGUT AND LOWER OB RIVER REGION

Over the past four decades, in the taiga areas of the Surgut and Lower Ob River Region, six unique burial objects of the Early Iron Age with a large number of imported and local goods have been discovered: single graves, a hoard with shaman’s regalia and a burial of ittarma dolls personifying a group of warriors who died in a foreign land. The studied sites belonged to representatives of the local elite. No similar complexes of the Stone and Bronze Ages have been found. This testifies to the presence of social stratification in the Ugrian and Ugrian-Samoyedic society of the western area of the Kulayka cultural-historical community (KCHC) in the 1st–4th centuries BC. Meanwhile, the emergence in the region of bastion-tower fortresses, anthropomorphic copper figurines in helmets and “solar” crowns, as well as the find of an arrowhead of the “Kulayka culture type” in a dwelling of the Beloyarskaya culture suggest that the formation of the image of a warrior-leader-bogatyr-spirit and of the military, property-owing and cult elite separated from the ordinary community members started perhaps even earlier – around the middle of the 1st millennium BC. The main prerequisite for these phenomena, as well as for the appearance of iron products in the taiga communities of the Ob River Rregion in the absence of a producing economy (animal husbandry, agriculture), was the involvement of hunters-fishers in the north of Western Siberia into the Eurasian economy as regular suppliers of furs.

The group of depressions Krivaya 3 of the Middle Ages (the excavation results of an above-ground non-residential construction on the left bank of the Ob river 2017)

В статье представлены результаты раскопок одного из сооружений объекта культурного наследия «Группа впадин Кривая 3», расположенного в Нефтеюганском районе ХМАО-Югры. Несмотря на отсутствие археологических предметов, сооружение предположительно отнесено к категории промыслово-хозяйственных построек эпохи Средневековья. Авторы поднимают проблему создания четкой методики исследования археологических объектов, сложно поддающихся идентификации, и предлагают свою систему доказательств антропогенного происхождения и назначения сооружения.

Peculiarities of Intercultural Interaction in the Early Iron Age in the Surgut Ob River Region (by materials of the ceramics of the settlement Barsova Gora III/66)

The article presents the results of technical and technological analysis of ceramics from the settlement of the Beloyarka culture Barsova Gora III/66. There are three groups of pottery. Group 1 includes ceramics of the Beloyarka culture. It is characterized by the use of low-sand ferruginous natural clays, possibly pre-treated. The main forming mass recipe is unmixed: clay + chamotte. Group 2 includes pottery of a mixed appearance with an admixture of grit. It could have been made in the settlement by potters with mixed pottery skills, which were formed as a result of integration (possibly marriage) contacts between the bearers of the Beloyarka culture and the bearers of other pottery traditions, probably the Kulma and Itkul cultures. Group 3 includes an imported vessel with an artificial addition of metallurgical slag. It reflects the contacts of the Beloyarka population of Barsova Gora with groups of other cultures, from whom a metal could be imported for the production of various items. The selected groups may reflect active integration processes and intercultural contacts between the bearers of the Beloyarka culture on Barsova Gora and representatives of other cultures. These links could be both trade and exchange in nature, when the Beloyarka people imported metal for the production of items, and marriage, when some carriers of pottery traditions found their way to the Beloyarka settlements, as a result of which there was a mixture of skills in technology, shaping and ornamentation of ceramics.

Hydrochemistry, chemical weathering and their significance on carbon cycle in the Heilong (Amur) River Basin, Northeast China

Chemical weathering is regarded as a “geological thermostat”, affecting the global carbon cycle and long-term climate stability, and hydrochemistry of river is the important way to study weathering. The Heilong River (Amur River), as one of the largest rivers in the temperate/cool temperate zone, has received few studies on the chemical weathering rate and its contribution to the global carbon cycle in the entire Chinese section. This paper presents the hydrochemistry of river water, lake water, and groundwater from the arid upper reaches, the Greater Hinggan Mountains in the middle reaches, and the fluvial plain in the lower reaches of the Heilong River. TDS values range from 26.8 mg/l to 1141 mg/l with an average of 189 mg/l. The arid upper reaches are affected by strong evaporation and/or evaporite minerals dissolution, and the ion contents of some surface water and underground water exceed the quality standard for drinking water. Although the downstream flood plain area is highly industrial and agricultural, water chemistry shows that anthropogenic activities have not significantly deteriorated water quality. The chemical weathering rate of the small granitic and basaltic watersheds in the Heilong River Basin is within the lowest range in the world, which further demonstrates the control of climate factors on chemical weathering. The calculated CO2 consumption flux from silicate weathering in the Heilong River Basin is from 82.3 × 109 to 196 × 109 mol/y, accounting for 0.95%–2.25% of the global consumption values with a proportion of area of ∼1.2%. Compared with other temperate/cool temperate rivers worldwide, it is comparable to the Yenisei River in Siberia, but much higher than the Ob River and Lena River in Siberia, Mackenzie River and Yukon River in North America.