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1.
The paper suggests an accurate approach to studying carbonate equilibrium in the water of the Razdol’naya River. The approach involves measuring pH by Pitzer’s scale, using a cell without liquid junction; measuring the total alkalinity by Bruevich’s technique; and using apparent constants of carbonate equilibrium with regard for the organic alkalinity. The Pitzer technique was employed to calculate the apparent constants of carbonate equilibrium in solution that models the riverine water: Ca(HCO3)2–NaCl–H2O within the range of alkalinity of 0–0.005 mol/kg and temperatures of 0–25°C. Carbonate equilibrium in the water of the Razdol’naya River was sampled for studying at eight sites during all four seasons. Although the contents of biogenic compounds in the water are high, they can merely insignificantly affect the acid–base equilibrium, which is controlled in the riverine water by carbonate equilibrium and the concentrations of humic substances, which play the greater role, the greater the discharge of the river. In addition to the production and destruction of organic matter, carbonate equilibrium in the river is also affected by the supply of humic substances with soil waters and total alkalinity with groundwaters. The fluxes of alkalinity and humic substances annually brought by the Razdol’naya River to Amur Bay are evaluated at 1.33 × 109 mol and 9.9 × 106 kgC, respectively. The carbon dioxide export with the Razdol’naya River is equal to the alkalinity flux and does not depend on the weathering mechanisms.  相似文献   

2.
Heavy metal contamination in the sediment of the Second Songhua River   总被引：1，自引：0，他引：1  
The Second Songhua River was subjected to a large amount of untreated effluent from petrochemical industries in Jilin City in the 1960s to the 1970s. The objectives of this study were to investigate the mercury and other heavy metal contamination in the sediment of the river. The river bottom sediment was sampled from the river segment between Jilin City to Haerbin City in 2005. Total concentrations of Hg, Cd, Cu, Cr, Pb, Zn, Ni, As, Sc, and major cations （A1, Fe, Mg, Ca, K, Na） in the sediment were measured by atomic fluorescence spectrometer, ICP-MS, and ICP-OES, respectively, following digestion with various acids. We found the concentrations of most elements in the uncontaminated sediment were significantly correlated to those of Sc.  相似文献   

3.
Under the tectonodynamic process, crustal materials tend to experience two modes of adjustment: (1) structural (physical) adjustment, manifested by folding, faulting, uplifting, downwarping, etc.: (2) compositional adjustment, represented by element migration, concentration and dispersion, crystalline and dynamic differentiation of crystals, metamorphism, etc. (Yang Kaiqing. 1986; Yang Kaiqing et al., 1986). The dynamic adjustment of crustal materials in the middle-lower reaches of the Yangtze mainly occurred in the Mesozoic under the conditions of intense collision between the North China (Dabie) massif and the Yangtze massif. The structural adjustment refers to various types of deformation within the two massifs and the intensive shortening of the stratigraphic coyer of the Yangtze massif, whereas the compositional adjustment implies the structural remelting of the basement and the ore. and rock- forming processes in the two massifs.  相似文献   

4.
A study has been made about the structural attribute of the NNW-trendingShizikou linear image belt in the head area of the reservoir of the Yangtze River Gorges and theevaluation of its crustal stability. On the basis of regional geological surveys and by making astructural analysis and a multidisciplinary study, it has been ascertained that the segment withthe best displayed image characteristics is marked by a gravity gliding structure with a multilay-er gliding fold type architecture. This paper also analyzes the medium conditions, slope struc-ture and dynamic setting for the formation of the structure system.  相似文献   

5.
Damming effect on the distribution of mercury in Wujiang River   总被引：2，自引：0，他引：2  
Seasonal changes in total mercury concentrations in surface water were observed for the Wujiang River, with higher values at the time of greater flow. The total mercury in this river was mostly associated with suspended particles, particulate mercury accounting for 84% of the total mercury flux on average during the high flow period, and 52% of the total mercury flux on average in the low flow period. Significant losses of Hg from the water were observed in the downstreams of the reservoir. In addition, the concentrations of particulate mercury in the downstreams of reservoir appeared to have been enhanced by sediment re-suspension and shoreline erosion caused by flood discharge, while the filtered portion decreased. These observations suggested that reservoirs played an important role in controlling the transport and fate of mercury in the Wujiang River.  相似文献   

6.
Based on the analytical results for 101 samples from 50 survey spots,this paper describes the changes in rations of various components in calcium carbonate from the sea area at the Pearl River mouth with pH.Relations of ∑CO2 with salinity,and Ca concentration with salinity in different parts of the river mouth have been established.The annual throughput of Ca from the Pearl River and the saturation degrees of calcite and aragonite have been calculated.  相似文献   

7.
Erosion products in stream water occur in the form of either dissolved species or solid particles (suspension). The suspended material not only acts as a carrier but also plays an important role in the circulation process of pollutants. Knowledge on the n…  相似文献   

8.
The average annual value of COD (chemical oxygen demand) fluxes of the Changjiang River (Yangtze River) and its main tributaries in the past decade (i.e., 1991–2000), has been evaluated. Based on the data from the Datong Hydrological Station (DHS), it was found that the Dongting Lake drainage basin contributed the greatest water discharge (35.8%) and COD flux (48.3%) among the main tributary drainage basins, followed by the Poyang Lake drainage basin with the contributions of 15.4% and 19.3%,respectively. By the end of the year of 2000, COD flux in the Changjiang River rose by almost 45% relative to that in the year of 1991, reaching about 1941000 ton/a at DHS. Statistical analysis revealed that industrial wastewater discharge, as well as COD in it, was found decreasing in the same period, due to the gradual reinforcement of environmental management. Moreover, correlation analysis indicated that non-point pollution from agriculture and increasing discharge of domestic sewages caused by rapid growth of population along the Changjiang River drainage valley should be responsible for the high COD. Furthermore, with the current trend of population growth and agricultural development in this basin, water quality of the Changjiang River, in terms of COD level, is going to deteriorate in the near future. Thus, the rational applications of fertilizers and pesticides in agriculture and the proper treatment of domestic sewages before they are discharged would be the most concerned controlling parameters.  相似文献   

9.
Plate subduction leads to complex exhumation processes on continents. The Huangling Massif lies at the northern margin of the South China Block. Whether the Huangling Massif was exhumed as a watershed of the middle reaches of the Paleo-Yangtze River during the Mesozoic remains under debate. We examined the exhumation history of the Huangling Massif based on six granite bedrock samples, using apatite fission track (AFT) and apatite and zircon (U-Th)/He (AHe and ZHe) thermochronology. These samples yielded ages of 157–132 Ma (ZHe), 119–106 Ma (AFT), and 114–72 Ma (AHe), respectively. Thermal modeling revealed that three phases of rapid cooling occurred during the Late Jurassic–Early Cretaceous, late Early Cretaceous, and Late Cretaceous. These exhumation processes led to the high topographic relief responsible for the emergence of the Huangling Massif. The integrated of our new data with published sedimentological records suggests that the Huangling Massif might have been the watershed of the middle reaches of the Paleo-Yangtze River since the Cretaceous. At that time, the rivers flowed westward into the Sichuan Basin and eastward into the Jianghan Basin. The subduction of the Pacific Plate beneath the Asian continent in the Mesozoic deeply influenced the geomorphic evolution of the South China Block.  相似文献   

10.
In an annual cycle from March 2005 to February 2006, benthic nutrient fluxes were measured monthly in the Dongtan intertidal flat within the Changjiang （Yangtze River） Estuary. Except for NH4^＋, there always showed high fluxes from overlying water into sediment for other four nutrients. Sediments in the high and middle marshes, covered with halophyte and consisting of macrofauna, demonstrated more capabilities of assimilating nutrients from overlying water than the low marsh. Sampling seasons and nutrient concentrations in the overlying water could both exert significant effects on these fluxes. Additionally, according to the model provided by previous study, denitrification rates, that utilizing NO3- transported from overlying water （Dw） in Dongtan sediments, were estimated to be from -16 to 193 μmol·h^-1·m^-2 with an average value of 63 μmol·h^-1·m^-2 （n=18）. These estimated values are still underestimates of the in-situ rates owing to the lack of consideration of DN, i.e., denitrification supported by the local NO3^- production via nitrification.  相似文献   

11.
The paper deals with the metallogenic conditions and regularities of the region ol the lower-middle reachesof the Changjiang River in China. The complicated structural network with the Changjiang (Yangtse) deepfracture as its trunk is the leading rock-and ore-controlling structure of the metallogenic belt. Thehigh-potassium granodiorites of the first magmatic sequence of the Mesozoic Yangtse syntexis type and thesodium-rich diorites of the second sequence are genetically related to the copper ore series and the iron ore se-ries respectively. and occur respectively in the block-faulted and-folded uplift area and the down-faulted vol-canic basin as well as the transitional zone between the two. The ore-hosting horizons show specific associa-tions of rocks and often contain ore beds basically of stratabound nature.  相似文献   

12.
An analysis of the planform changes of the Colombian reach of the Amazon River was carried out over a period of 19.9 years. Remote sensing image processing techniques were applied to Landsat images acquired in 1986, 1994, 2001 and, 2006. These images were selected based on minimal daily water level variations, while providing the widest temporal span. Plan view river changes and geomorphologic characteristics were examined to identify which channel pattern classification best represents this large tropical river system. Discharge was also analyzed to determine whether changes in the river's plan view are a direct response to variations in discharge. The system had a depositional tendency between 1986 and 2006, with a period where erosion was more intense than deposition between 1994 and 2001. Percent change in the plan view area of the system (1.4% yr−1) and the maximum migration rates (125 m yr−1) suggest that this reach of the Amazon is less active than reaches upstream and the downstream reach between the confluences of the Jutaí and Japurá Rivers. Variations in discharge appear to be responsible for deposition and erosion dynamics observed after this remote sensing analysis in the Colombian reach of the Amazon River. Characteristics including multiple channels with vegetated islands developed from within-channel deposition, meandering planform, lateral activity of channel margins, and the absence of islands with saucer-like morphology suggest a multichannel, meandering pattern for this reach of the Amazon, that corresponds to a laterally active anabranching river.  相似文献   

13.
Investigation of the Upper Callovian to Lower Kimmeridgian microfossils from the Makar’yev reference section (Unzha River, East European Platform) has been carried out. The section is characterized by ammonite debris and abundant associations of benthic and planktic foraminifers. It is a perfect object for stratigraphic and paleoecological researches. The biostratigraphic distribution of foraminifers from the Makar’yev section allows one to identify standard foraminifera zones of the East European Platform, as well as to upgrade some of them. The analysis of vertical and lateral ammonites and foraminiferal distribution, completed with litho stratigraphy, has precised the stratigraphic volume and position of boundaries of several lithological units.An improved stratigraphic scheme for the Kostroma area of the Moscow Depression is proposed. Analysis of the composition, structure, and dynamic changes of the foraminiferal assemblages has been performed. The morphofunctional analysis of foraminiferal genera has for the first time identified how foraminiferal morphogroups differing in their life style and feeding strategy varied with short-term paleoenvironmental changes. These morphogroup changes allow establishing four ecostratigraphic levels. These paleoecological data have been calibrated along with geochemical factors. They have shown a crisis of foraminiferal association during the Late Oxfordian and Early Kimmeridgian. A similar crisis has also been discovered in the north of Siberia, which may be an argument for its global distribution. The analysis of the taxonomic composition and the density of foraminiferal associations, in parallel with the structure of the association, has revealed a succession of transgressive and regressive events during the Late Callovian-Early Kimmeridgian. It allows the typification of each assemblage in relation with each event and underlines the occurrence of second-order sea-level fluctuations (middle part of the Middle Oxfordian and the earliest Kimmeridgian).  相似文献   

14.
The Yangtze （Changjiang） River as the largest fiver originating from eastern Tibetan Plateau, has increasingly attracted considerable attention of many researchers for almost one hundred years. The fiver linking the Tibetan Plateau with the West Pacific Marginal Sea, encompasses variable source rocks and complicated drainage patterns and spans across distinct climate zones. The increasing human activities in the last 2000 years have significantly changed the weathering process and sediment source-to-sink pattern in the fiver basins. In terms of this, the Yangtze drainage basin as well as the deltaic and coastal areas can be regarded as one of the best regions in the world to investigate the source-to-sink process of continental sediments into the marginal sea. In the past ten years we systematically measured elemental and Sr-Nd-Pb isotopic compositions of the Yangtze riverine sediments which were collected from the mainstream and main tributaries. Analytical results clearly showed that the Yangtze sediments yield geochemical compositions different from those of other fiver sediments due to the very complicated source rock types and variable chemical weathering regimes in the large drainage basin. REE and Sr-Nd isotopic compositions suggest that the sediment source-to-sink pattern in the modern Yantze River basins varies considerably from the upper basin to the lower valley. Different chemical compositions among the main tributaries and the mainstream are responsible for the compositional variations of the Yangtze River sediments. It is a piece of quite challenging work to establish a sediment source-to-sink model to quantifying the contributions of the main tributaries to the mainstream.  相似文献   

15.
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16.
The Daning River is a very important tributary in the Three Gorges Reservoir area. It is also a famous scenic spot. Anomalies appeared after water storage of the reservoir in June, 2003. In September, 2003, eutrophication monitoring in the 135-m backwater reach of the Daning River was conducted and the data were simply analyzed. The assessment result is that water body in the segment from Shuauglong to Longmen was mesotrophic or eutrophic. At the same time, the causes of its nutritional change were discussed, and counter-measures have been proposed.  相似文献   

17.
The results of bio- and lithostratigraphic studies of the Givetian-Frasnian rocks in the Tsil’ma River basin are reported. They suggest regularities in sedimentation: distinct rhythmicity and similar succession in the structure of formations. We have identified five palynocomplexes that characterize the formations and make it possible to accomplish a confident biostratigraphic subdivision of sections. Their correlation with coeval complexes in the adjacent areas has been accomplished. The results made it possible to unravel specific features of miospore assemblages formed in the continental and coastal-marine facies.  相似文献   

18.
Water resources system is composed of natural water subsystem and social water subsystem. And it is a complicated large system, which contains certain regional background, as well as specific framework, function and dynamic balance. The evaluation of the water resources system needs the viewpoint of sustainable development and the measurement according to water resources system carrying capacity, which holds the meaning of both water resources carrying capacity and water environment carrying capacity. The Changjiang River Delta is a very important area in China. As the local water resources are concerned, the Delta is an area lack of water as a matter of fact. The water resources system of the Delta experiences a long, intricate and degenerate period. The lack of water due to resources shortage in the 1950＇s was converted to that due to water quality from the 1980＇s. Furthermore, the status of water shortage sharpens gradually. The representations are summarized as follows： firstly, the discharge amount of wastewater and polluted water is large all along. Secondly, the pollution status of rivers, which involve the Changjiang River, the Grand Canal, the rivers in cities and the rivers in small towns and villages, is noticeable. Thirdly, water quality of Taihu Lake is worth of more attention. Therefore, the countermeasures on the reconditioning and regulating of water resources system in the Delta demands the following new strategies, such as to treat the rivers, the lakes and the seas as one overall system, to improve, harmonize and counterpoise water resources system carrying capacity, to implement the integrated management of water resources, which means the integrated management of drainage area along with the regional area, especially the integrated management of city water, and to carry on water saving and scientific use so as to increase the efficiency of water use, and so on.  相似文献   

19.
Quantitative estimation of ground and stream waters draining through sedimentary rocks of the Pab and Mor ranges (Jurassic-Cretaceous) and the Bela ophiolite has been made. The degree of correspondence among cations and anions has been estimated in order to evaluate their mutual relationships. The abundance of major ions is interpreted to be related to bedrocks and climatic conditions, which may contribute to the genetic affiliation. The log TDS and Na/Na Ca ratio reflected supremacy of weathering of rocks with some influence of evaporation. Ionic relationship is exhibited in the form of Stiff diagrams. Patterns of ionic composition revealed high NaCl, medium Ca(HCO3)2 and low MgSO4. Piper diagram has been used to classify the hydrofacies. The important hydrogeochemical parameters have been estimated for assessment of groundwater quality for domestic purposes in accordance to WHO. Irrigation water qualities have been evaluated in terms of EC, SAR, RSC, ESP and pH.  相似文献   

20.
Microbial remediation potential to crude oil-contaminated soils in the Yellow River delta was assessed. Hydrocarbons degradaters were isolated from the soil samples obtained from the Yellow River delta. A selected mixed microbial consortium （MYRD-1） and two individual isolates （YRD-3 and YRD-4） were further tested for optimal performance and degradation of different hydrocarbons. The results demonstrated that the optimal crude oil biodegradation conditions for the mixed microbial consortium were at temperature of 28 ℃, salt concentration of 15‰, and pH of 8, and the optimal C/N/P ratio was found to be 70 ： 3 ： 1. Isolate YRD-3 could only use n-alkanes （C8, C12 and C16） as the sole source of carbon and YRD-4 could transform only naphthalene and phenanthrene. The optimal performance conditions for both isolates were at salt concentration of 20‰, and pH of 7, and C/N/P ratio of 80 ： 5 ： 1, but the temperature for YRD-3 was 24 ℃ and 28 ℃ for YRD-4. Capacity to transform hydrocarbons for the mixed microbial consortium and both isolates could be improved in a liquid medium supplemented using a mixture of alkanes and/or aromatic hydrocarbons （naphthalene and phenanthrene）, but the transformation of different substrates by MYRD-1 was higher than both isolates, showing the importance of mixed bacteria （microbial community） in hydrocarbon degradation.  相似文献   

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