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1.
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   

2.
River related tourism in Europe — an overview   总被引：1，自引：0，他引：1  
Josef Steinbach 《GeoJournal》1995,35(4):443-458
This paper gives an overview of different types of river-oriented tourism in Europa. All of them belong to the growing sectors of the business. They are based on essential characteristics of river landscapes as common factors of attractiveness. A series of supply-oriented indicators is used to draw up a ranking of the European river-cruise-districts. The cruising market is characterized by extensive investment strategies of some leading companies. In order to attract also younger people and families, they have to develop new structures of supply. The canal-systems of Western Europe form the most important prerequisite for houseboat-tourism. It's main districts can be ranked by the indicator: number of the types of charterable boats. The rising request for adventures and progress in kayak- and raft-technology are driving factors to whitewater-tourism. It's more important districts in the Alps, Pyrenees as well as in different medium mountains are shown. The shift into higher mountain regions causes ecological problems and severe personal risks. Biking has become a prefered leisure activity with river basins as the main goal areas. Some essential characteristics are given by the examples of two most significant routes: the Austrian Danubetrail and the Bavarian Altmühl-route. Finally, the planning concept of integral management of river basins is discussed which should support and coordinate the different styles of river-oriented tourism.  相似文献   

3.
The River Ganges being the most sacred river and lifeline to millions of Indians in serving their water requirements is facing excessive threat of pollution. Under various river management and conservation strategies for its protection, the assessment of water quality of its main tributary Ramganga River is lacking. This study focuses on assessment of physicochemical and heavy metal pollution of the Ramganga River by application of multivariate statistical techniques. Sampling of Ramganga River at sixteen sampling sites was carried out in three seasons (summer, monsoon and winter) of 2014. The collected water samples were analyzed for physicochemical parameters and heavy metals. Results from cluster analysis (CA) of the data divided the whole stretch of the river into three clusters as elevation from 1304 to 259 m as less polluted, from 207 to 154 m as moderately polluted and from elevation 154 to 139 m as high-polluted stretches with anthropogenic as main sources of pollution in high-polluted stretch. Principal component analysis of the seasonal dataset resulted in three significant principal components (PC) in each season explaining 72–8% of total variance with strong loadings (>0.75) of PC1 on fluoride (F?), chloride (Cl?), sodium (Na+), calcium (Ca2+), magnesium (Mg2+), bicarbonate (HCO3 ?), total dissolved solids and electrical conductivity. Temporal variation by one-way ANOVA (Analysis of Variance) showed significant seasonal variation was in the pH, chemical oxygen demand, biochemical oxygen demand, turbidity, HCO3 ?, F?, Zn, cadmium (Cd) and Mn (p < 0.05). Turbidity showed approximately a twofold increase in monsoon season due to rainfall in the catchment area and subsequent flow of runoff into the river. Concentration of HCO3 ?, F? and pH also showed similar increase in monsoon. The concentration of Zn, Cd and Mn showed an increasing trend in summers compared to monsoon and winter season due to dilution effect in the monsoon season and its lasting effect in winters.  相似文献   

4.
The Broken River Embayment is a major transverse structure in the Tasman Orogen in northern Queensland. Bell (1980) suggested that it is a hinge zone of an orocline, which he named the Big Bend Megafold. An alternative explanation, presented in this paper, involves a Silurian‐Devonian triple plate junction.  相似文献   

5.
The Khoshk River passes through Shiraz City, southwest Iran. It passes through the populated urban area of Shiraz and receives and carries different kinds of industrial and urban solid and liquid wastes produced by industries and domestic sewage. The obje…  相似文献   

6.
Water samples were collected from the Changjiang River (Yangtze River) in May 2005, after the impoundment of the Three Gorges Reservoir (TGR), to examine the influence of the TGR and large lakes on material delivery to the estuary of the Changjiang River. The concentrations of suspended particle material (SPM), dissolved silica (DSi) and biogenic silica (BSi) in the main stream were analyzed. The concentrations of DSi and BSi in the main channel of the Changjiang varied between 73 and 100 and 1.1–15 μmol/l, with a distance weighted average of 81 and 8.0 μmol/l, respectively. A calculation shows that live diatom comprises only an average value of 5.2 % of the BSi in the Changjiang River, and most of BSi may come from drainage basin. The concentrations of BSi and the ratios of BSi/SPM were relatively low in the Changjiang River compared to other rivers throughout the world, but the BSi carried in suspension by the Changjiang River was an important component of the rivers silicon load (i.e. ~13 %). SPM, DSi and BSi concentrations as observed in the Changjiang River tend to decrease from the upper sections of the river to the Three Gorges Dam (TGD), reflecting sedimentation associated with BSi trapping and DSi retention in the TGR in the normal-water period. SPM and BSi retention are more strongly influenced by the TGD compared to DSi. About 98 % of SPM, 72 % of BSi and 16 % of DSi were retained within the TGR in May 2005. The fluxes variations of DSi, BSi and SPM suggested that the large lakes and dams had a coupled effect on the transportation of DSi, BSi and SPM in the normal-water period. Such a change in silicon (DSi and BSi) balances of the Changjiang River will affect the ecological environment of the Changjiang estuary and its adjacent sea to some extent.  相似文献   

7.
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   

8.
Detailed time-series studies on the major ion geochemistry of tropical peninsular Indian rivers are lacking. In this backdrop, a small stretch of the Godavari River, globally ranking 32nd in terms of total discharge, is chosen for sampling at its mouth. The objectives are： （1） to understand the natural and anthropogenic sources controlling the major ion chemistry of the Godavari River at Rajahmundry, （2） processes controlling the temporal variations in major ions over a period of two years, （3） comparison of total dissolved solid （TDS） fluxes and weathering rates at Godavari River with other major tropical rivers. A total of 47 surface samples were collected, bimonthly, at five stations in the Godavari at Rajahmundry spaced over a distance of 6 km for a period of two years. Water samples were collected in pre-cleaned PP bottles. Parameters like temperature, pH, conductivity, dissolved oxygen, alkalinity were measured on-site. Samples collected for analysis of major ions were processed within a few hours of collection by filtering through 0.45 mm pore size millipore filters. Filtered water samples for major ions were transported to the laboratory in cleaned 250 mL PP bottles. Sodium and K were measured on a Flame Photometer, Ca and Mg on a Flame Atomic Absorption Spectrophotometer, Cl, NO3, SO4 by Ion Chromatography and SiO2 on a spectrophotometer. Chemical weathering of rocks controls the major ion chemistry of the Godavari River at its mouth as indicated by the alkaline nature of the river and dominant presence of Ca, Mg and HCO3 ions. Ca/Mg and Na/Mg ratios point its source to a mixture of lithological assemblages of basalt, granite-granodiorite,  相似文献   

9.
Geochemical cycling has received wide attention due to the need to understand the pathways of pollutants through our present environment. In this regard the Yangtze River plays a significant role in putting those pollutants into the East China SeafWorld Oceans. The Yangtze River is of high sedimentation rate and water discharge. The watershed covers variable climate regions from temperate to subtropical and from semiarid to humid. Twenty three （23） sampling locations at the estuary have been selected for understanding the dynamic relationships. The elements （Cl^-, SO4^2-, Na^＋, K^＋, and Ca^2＋） show conservative behavior during mixing of fresh water with saline water whereas Mg^2＋, Mn^2＋ show a non-conservative pattern . The relationships between Na^＋/SO4^2- and Cl^-/SO4^2- molar ratios show a mixing of more than two water sources.  相似文献   

10.
The Huangpu River supplies eighty percent of daily water used for life and industry for about 20 million people in Shanghai, China. Industry and domestic sewerage from the metropolis is mainly released into the Huangpu River, which flows through the Shanghai City area. The pollution caused by city life and production in the Huangpu River has occurred for years. In this paper, the contents of heavy metals （Cu, Pb, Cr, Cd, and Hg）, total organic carbon （TOC）, and polynuclear aromatic hydrocarbons （PAHs） in the Huangpu River are studied. Data from environmental monitoring from 1991 to 2002 are compared to understand the variation and trends of the pollution. Results indicate that metals have been reduced efficiently, but organic pollutants develop in an aggravating trend as domestic sewage increases. The variation of the organic pollutant concentrations, which are lower than those of other similar rivers of China, US, and Canada,  相似文献   

11.
Hydrogeochemistry of Wujiang River Water in Guizhou Province,China   总被引：9，自引：3，他引：9  
The chemical composition of Wujiang River water represents that of river water from the typical carbonate areas.Ite hydrogeochemical characteristics are different from those of global major rivers.The Wujiang River and its tributaries have high total dissolved solid concentrations,with Ca^2 and HCO3^- being dominant,Mg^2 and SO4^2- coming next.Both Na^ K^ and Cl^- Si account for 5%-10% of the total cations and anions,respectively,These general features show the chemical composition of river water is largely controlled by carbonate weathering,with the impact of silicate and evaporate weathering being of less importance.Production activity,minin practice and industrial pollution also have some influence on the chemical composition of rive water.  相似文献   

12.
The interacting effect of pH, phosphate and time on the release of arsenic (As) from As-rich river bed sediments was studied. Arsenic release edges and kinetic release experiments (pH range 3–10), in the absence and presence of phosphate, coupled with sequential extraction procedures, SEM/EDX analyses and geochemical calculations, were carried out to evaluate As remobilisation and to elucidate the mechanisms involved. The results showed that As release underwent pronounced kinetic effects, which were strongly influenced by pH and phosphate. Remobilisation of As after 24 h was low (between ~1 and 5%) and varied slightly with pH, whereas alkaline conditions generally promoted As remobilisation after 168 h, with up to 12–21% of total As released. The results showed that depending on the pH and sediment considered, the release of As increased dramatically after ~48–72 h, suggesting that different processes are involved at different reaction periods. The addition of phosphate (1 mM) increased both the amount of As released (between 2 and 8 times) and the rate of As release from the sediments within the entire pH range (3–10) and period (168 h) studied. Moreover, in some cases, it also affected the shape of the As release edges and kinetic profiles. The similarities in the release profiles and the positive correlations between As and some sediment components, especially Fe and Al hydroxides, and organic matter—which appears to play a key role at high pH—suggest that As release from the studied sediments may be associated with solid phase dissolution processes under both acid and alkaline pH, whereas desorption plays a key role in the short term and at natural pH conditions, especially in the presence of phosphate, which acts as an As-displacing ligand. Evaluation of As mobility based on short-time leaching experiments may seriously underestimate the mobilisation of As from sediments.  相似文献   

13.
Climate change is receiving more attention from researchers as the frequency of occurrence of severe natural disasters is getting higher. Tropical countries like Malaysia have no distinct four seasons; rainfall has become the popular parameter to assess climate change. Conventional ways that determine rainfall trends can only provide a general result in single direction for the whole study period. In this study, rainfall series were modelled using additive Holt–Winters method to examine the rainfall pattern in Langat River Basin, Malaysia. Nine homogeneous series of more than 25 years data and less than 10% missing data were selected. Goodness of fit of the forecasted models was measured. It was found that seasonal rainfall model forecasts are generally better than the monthly rainfall model forecasts. Three stations in the western region exhibited increasing trend. Rainfall in southern region showed fluctuation. Increasing trends were discovered at stations in the south-eastern region except the seasonal analysis at station 45253. Decreasing trend was found at station 2818110 in the east, while increasing trend was shown at station 44320 that represents the north-eastern region. The accuracies of both rainfall model forecasts were tested using the recorded data of years 2010–2012. Most of the forecasts are acceptable.  相似文献   

14.
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   

15.
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   

16.
Surface runoff in the Wujiang River watershed was simulated by a GIS-based method using precipitation, hydrology data, and land-use data. The volume of surface runoff is chiefly controlled by climates, topographical characteristics and types of land use at the watershed. Five subwatersheds that can represent the whole watershed were chosen and their average annual precipitation, average annual surface runoff and current land use were calculated respectively in the grid model of the Wujiang River watershed based on the climate and hydrology data from 1965 to 2000 and the land-use data acquired in the year of 2000. Surface runoff is assumed to be a function of precipitation and land use and the multiple regression tool is used to determine the relationship between surface runoff, precipitation and present land use. Thus, the rainfall-runoff model for each land-use type has been established. When calibrating these models, the results show that the percent errors are all below 7%, which indicates that the accuracy of this simulation is high.  相似文献   

17.
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   

18.
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   

19.
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   

20.
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   

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