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Sample records for brahmaputra river

  1. ICHTHYOFAUNAL DIVERSITY OF LOWER REACHES OF THE BRAHMAPUTRA RIVER, ASSAM

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    D. Sarma

    2012-05-01

    Full Text Available An investigation was carried out from February 2009 to January 2010 in the core fish landing centres of Goalpara district, Assam to evaluate the present status of ichthyofaunal diversity of the lower reaches of Brahmaputra River. A total of 97 species including exotic species belonging to 56 genera of 26 families were recorded from all the fish landing centres. Among these, according to IUCN status, 5 species are endangered, 21 species vulnerable, 29 species lower risk-near threatened, 7 species lower risk-less concern and other 29 species are not evaluated. The families recorded were Notopteridae, Clupeidae, Engraulidae, Cyprinidae, Psilorhynchidae, Balitoridae, Cobitidae, Bagridae, Siluridae, Schilbeidae, Sisoridae, Clariidae, Heteropneustidae, Chacidae, Mugilidae, Beloniidae, Synbranchidae, Mastacembelidae, Chandidae, Nandidae, Cichlidae, Gobiidae, Anabantidae, Belontidae, Channidae and Tetradontidae. Seasonal variations of the fishes were also noticed remarkably. The taxonomic composition of the fish fauna suggests, Cyprinidae were the most dominant family with 39 representative species (42.8% followed by Bagridae having 7 species (7.7%. The study reveals that lower reaches of River Brahmaputra is very rich in ichthyofaunal diversity. However, strategies such as controlled harvest, checks on growth of exotic species, controlling water pollution etc. are suggested for conservation of the native and endemic fish species of the region.

  2. Using radar altimetry to update a large-scale hydrological model of the Brahmaputra river basin

    DEFF Research Database (Denmark)

    Finsen, F.; Milzow, Christian; Smith, R.;

    2014-01-01

    Measurements of river and lake water levels from space-borne radar altimeters (past missions include ERS, Envisat, Jason, Topex) are useful for calibration and validation of large-scale hydrological models in poorly gauged river basins. Altimetry data availability over the downstream reaches...... of the Brahmaputra is excellent (17 high-quality virtual stations from ERS-2, 6 from Topex and 10 from Envisat are available for the Brahmaputra). In this study, altimetry data are used to update a large-scale Budyko-type hydrological model of the Brahmaputra river basin in real time. Altimetry measurements...... are converted to discharge using rating curves of simulated discharge versus observed altimetry. This approach makes it possible to use altimetry data from river cross sections where both in-situ rating curves and accurate river cross section geometry are not available. Model updating based on radar altimetry...

  3. SPATIAL AND TEMPORAL CHANGES IN THE BRAHMAPUTRA RIVER BED

    Institute of Scientific and Technical Information of China (English)

    Prabhata K.SWAMEE; Barham PARKASH; Santanu SARMA

    2006-01-01

    A mathematical model based on data for the period 1957-1988 representing changes in space and time in the bed morphology of the 623 km long alluvial reach of the Brahmaputra River in Assam State, India has been developed. This model reveals that in the upper reaches the bed level decreases downstream exponentially with distance from a reference point, while in the lower reaches the exponential decrease is at a smaller rate probably due to differences in tectonic setting. The lower reach is marked by sinusoidal oscillations with a time period of about 9 yr. High runoff in 1977 seems to have caused a significant change as the maximum, average, and minimum bed level were decreasing before 1977 and these increased just after 1977 and then started decreasing at a lower rate than before. Smaller changes in shorter reaches governed by input of discharge and sediment from tributaries are superimposed on the overall degradation/aggradation character. The variation in degradation/aggradation with time is sinusoidal with a wavelength of 4,450 km before 1977 that reduces to about 1,038 km after 1977.

  4. Tectonic controls on the morphodynamics of the Brahmaputra River system in the upper Assam valley, India

    Science.gov (United States)

    Lahiri, Siddhartha K.; Sinha, Rajiv

    2012-10-01

    The Brahmaputra is one of the largest tropical rivers of the world and is located in an area of high structural instability as evidenced from the presence of a large number of earthquakes in the Himalayan catchment through which it flows. Syntectonic evidence of changes in the morphodynamics is difficult to identify for the large rivers. Nevertheless, we note that the Brahmaputra River has become astonishingly large in planform in a historical timescale. Reconstruction of planform changes over a period of 90 years in the upper reaches of the Assam valley shows that the 240-km-long channel belt is widening all along its course in the region. From the average width of 9.74 km in 1915, the channel belt has widened to the average width of 14.03 km in 2005 (44% widening), and in certain reaches the average widening is as high as 250%. However, the bank line shift is not symmetric along both banks. Further, the planform characteristics of the Brahmaputra River reveal significant spatial and temporal variability from upstream to downstream reaches, and we attribute this variability to tectonogeomorphic zonation of the river based on subsurface configuration and channel slope. Further, the tributaries joining the northern and southern banks of the Brahmaputra differ remarkably in terms of river dynamics, and this is attributed to the differences in tectonic regimes of the Himalaya in the north and the Naga Patkai hills in the south.

  5. Sovereign states and surging water: Brahmaputra river between China and India

    OpenAIRE

    Mahapatra, Sushanta Kumar; Ratha, Keshab Chandra

    2015-01-01

    Brahmaputra river basin is one of the most vulnerable areas in the world subject to combined effects of glacier melt, extreme monsoon rainfall and sea level rise. Water is emerging as a new possible irritant between China and India. For India, Water of Brahmaputra constitutes a major lifeline for people of Tibet and North Eastern states. The building of dams and diversion projects in Tibet by China is a matter of grave concern for lower riparian states. For China, it is having hidden inclinat...

  6. The Brahmaputra River: a stratigraphic analysis of Holocene avulsion and fluvial valley reoccupation history

    Science.gov (United States)

    Hartzog, T. R.; Goodbred, S. L.

    2011-12-01

    The Brahmaputra River, one of the world's largest braided streams, is a major component of commerce, agriculture, and transportation in India and Bangladesh. Hence any significant change in course, morphology, or behavior would be likely to influence the regional culture and economy that relies on this major river system. The history of such changes is recorded in the stratigraphy deposited by the Brahmaputra River during the Holocene. Here we present stratigraphic analysis of sediment samples from the boring of 41 tube wells over a 120 km transect in the upper Bengal Basin of northern Bangladesh. The transect crosses both the modern fluvial valley and an abandoned fluvial valley about 60 km downstream of a major avulsion node. Although the modern Brahmaputra does not transport gravel, gravel strata are common below 20 m with fluvial sand deposits dominating most of the stratigraphy. Furthermore, the stratigraphy preserves very few floodplain mud strata below the modern floodplain mud cap. These preliminary findings will be assessed to determine their importance in defining past channel migration, avulsion frequency, and the reoccupation of abandoned fluvial valleys. Understanding the avulsion and valley reoccupation history of the Brahmaputra River is important to assess the risk involved with developing agriculture, business, and infrastructure on the banks of modern and abandoned channels. Based on the correlation of stratigraphy and digital surface elevation data, we hypothesize that the towns of Jamalpur and Sherpur in northern Bangladesh were once major ports on the Brahmaputra River even though they now lie on the banks of small underfit stream channels. If Jamalpur and Sherpur represent the outer extent of the Brahmaputra River braid-belt before the last major avulsion, these cities and any communities developed in the abandoned braid-belt assume a high risk of devastation if the next major avulsion reoccupies this fluvial valley. It is important to

  7. Locality Record of Leptobrachium smithi Matsui, Nabhitabhata & Panha, 1999 (Anura: Megophryidae on the north bank of Brahmaputra river in India

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    Dipankar Dutta

    2013-12-01

    Full Text Available The genus Leptobrachium Tschudi, 1838 is currently represented by 32 species all over the world distributed throughout mainland and insular Asia with two species so far from India. Leptobrachium smithi is known from Rani-Gharbhanga Landscape, Borduar-Mayang Landscape, Barail Range and Barak Valley all from south of River Brahmaputra. We herein report additional distribution records of Leptobrachium smithi from Ultapani Reserve Forest, Shankarghala and Mathanguri of Manas National Park on the north bank of the River Brahmaputra. The report from Ultapani, Shankarghala and Mathanguri is an extension of range of species by around 100 to 176 km north. Mineralogic and stratigraphic data of Brahmaputra basin indicates that the Brahmaputra River has changed position several times during the Holocene. The presence of the species on the north bank across the river barrier may be attributed to the positional changes of the river and due to lateral shifting of the river.

  8. Fluvial process and morphology of the Brahmaputra River in Assam, India

    Science.gov (United States)

    Sarma, J. N.

    2005-09-01

    The Brahmaputra River finds its origin in the Chema Yundung glacier of Tibet and flows through India and Bangladesh. The slope of the river decreases suddenly in front of the Himalayas and results in the deposition of sediment and a braided channel pattern. It flows through Assam, India, along a valley comprising its own Recent alluvium. In Assam the basin receives 300 cm mean annual rainfall, 66-85% of which occurs in the monsoon period from June through September. Mean annual discharge at Pandu for 1955-1990 is 16,682.24 m 3 s - 1. Average monthly discharge is highest in July (19%) and lowest in February (2%). Most hydrographs exhibit multiple flood peaks occurring at different times from June to September. The mean annual suspended sediment load is 402 million tons and average monthly sediment discharge is highest in June (19.05%) and lowest in January (1.02%). The bed load at Pandu was found to be 5-15% of the total load of the river. Three kinds of major geomorphic units are found in the basin. The river bed of the Brahmaputra shows four topographic levels, with increasing height and vegetation. The single first order primary channels of this braided river split into two or more smaller second order channels separated by bars and islands. The second order channels are of three kinds. The maximum length and width of the bars in the area under study are 18.43 km and 6.17 km, respectively. The Brahmaputra channel is characterised by mid-channel bars, side bars, tributary mouth bars and unit bars. The geometry of meandering tributary rivers shows that the relationship between meander wavelength and bend radius is most linear. The Brahmaputra had been undergoing overall aggradation by about 16 cm during 1971 to 1979. The channel of the Brahmaputra River has been migrating because of channel widening and avulsion. The meandering tributaries change because of neck cut-off and progressive shifting at the meander bends. The braiding index of the Brahmaputra has been

  9. Annual cycle in lakes and rivers from CryoSat-2 altimetry — The Brahmaputra river

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    Villadsen, Heidi; Andersen, Ole Baltazar; Stenseng, Lars

    2014-01-01

    A key concern of the CryoSat-2 orbit has been its long repeat period of 369 days, which is usually undesirable for river and lake monitoring. However, the results of this study show that CryoSat-2 data can indeed be used for such monitoring by utilizing the high spatial coverage and the sub......-cycle period of 30 days. The performance of CryoSat-2/SIRAL altimetry for river level monitoring is investigated by studying river levels retrieved from Ganges and Brahmaputra. An evaluation of CryoSat-2 river levels from LRM, SAR and SARIn data is performed by comparing with Envisat data from the period in...... which the two missions overlapped (2010–2012). Time series constructed using simple linear interpolation are fitted with a model to compare the captured annual signals and amplitudes. The annual cycles seen in CryoSat-2 and Envisat altimetry data agree very well and provide confidence in using CryoSat-2...

  10. Changing river courses in the western part of the Ganga-Brahmaputra delta

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    Rudra, Kalyan

    2014-12-01

    The Ganga-Brahmaputra delta is the largest on Earth, the product of two of the world's largest and siltiest rivers. It is formed in a basin located over the zone where the Indian plate subducts beneath the Himalaya to the north and the Indo-Burman ranges to the east. The distributaries in the south-western part of the delta remain disconnected from the Ganga-Padma during the lean season, although they are still active in bank erosion and sediment transport during the monsoon. Four distributaries of the Bhagirathi-Hugli (the westernmost branch of the Ganga) have gone dry during known historical period. In many cases, the natural decay of rivers has been exacerbated by the human intervention, especially where rivers are embanked and no allowance made for their migration through meandering and avulsion. In the coastal zone where mangroves were cleared and creeks were embanked since the late 18th century, decay of channels, and advancement of the sea towards inland have been aggravated. The subsequent attempt of flushing the sediment load to the sea from the estuary to improve the status of navigation in the Bhagirathi-Hugli River was not successful to the level of expectation. This paper deals with the decay and changing courses of rivers in the western part of the Ganga-Brahmaputra delta.

  11. Assimilation of radar altimetry to a routing model of the Brahmaputra River

    DEFF Research Database (Denmark)

    Michailovsky, Claire Irene B.; Milzow, Christian; Bauer-Gottwein, Peter

    2013-01-01

    quantities of interest. This is the case for satellite-based radar altimetry. River-level variations can be tracked using radar altimetry at a temporal resolution between 10 and 35 days, depending on the satellite, but hydrologists are typically interested in river flows rather than levels and require...... of the main reach of the Brahmaputra River driven by the outputs of a calibrated rainfall runoff model. The extended Kalman filter was used to update the routed water volumes for the years 2008-2010. Model performance was improved with the Nash-Sutcliffe model efficiency for daily discharge increasing from 0.......78 to 0.84. The method uses very little in situ data and is easily implemented as an add-on to hydrological models, and it therefore has the potential for large-scale application to improve hydrological predictions in many river basins. ©2013. American Geophysical Union. All Rights Reserved....

  12. Natural environment assessment and vegetation indicators for IWRM scenarios in the Upper Brahmaputra River Basin

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    Wagner, I.; Exler, N.; Janauer, G. A.

    2009-04-01

    The Brahmaputra River originates in the highest mountain massif of the world, the Western Himalaya. Fed by ice-melt, snow and also monsoon rain from the northern slope of the Himalaya Range in its reach in Tibet develops into a braided river with many channels in a wide valley, where it receives important tributaries like the Lhasa River, before entering the constrained reach of the Great Brahmaputra Gorge. Downstream of the Gorge the river enters even more diverse landscapes in intensively cultivated Assam, where the braided river bed reaches its greatest lateral expansion. Monsoon related flooding causes the most severe effects in this densely populated reach on the south-eastern rim of the Himalaya Range, but intense flooding is also a great threat at upper parts of the river and in populated areas of some tributaries. IWRM plays an important role with regard to mitigating climate change effects, whether too much or too little water is available for human uses. The assessment of the natural environment in a multi-scale approach leads to the identification of essential indicators, which are the basis for modelling scenarios of future development as the spatio-temporal processes vary within scale and along the course of this Large River. In our assessment it was necessary to aggregate local vegetation structures for a generalised description at larger scales to bridge the gap between the hydrological modelling scale and respective ecosystem services resulting from the existing vegetation types. These indicators can be used to evaluate the influence of different ecosystem types on related IWRM activities and policies. Aside from more general wetland ecosystem services like flood retention of support of livelihood for the neighbouring population a focus was also set on wetland and water body ecotones where detectable by high-resolution RS techniques to evaluate vulnerability and biodiversity aspects.

  13. Heavy metals distribution in the sediments of Ganges and Brahmaputra Rivers

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    Subramanian, V. (Jawaharial Nehru Univ., New Delhi (India)); Van Grieken, R.; Van' t Dack, L. (Univ. of Antwep, Wilrijk (Belgium))

    1987-01-01

    Bed sediments were collected from the entire region of the Ganges basin and some parts of the Brahmaputra. In addition, selected stations were sampled for suspended sediments as well. The samples were analyzed for a number of heavy metals (Fe, Mn, Ni, Cr, Cu, and Zn) by the thin-film energy dispersive X-ray fluorescence technique. There are pronounced temporal and spatial variations in the heavy metals distributions. Suspended sediments are 5-10 times richer than the bed sediments. None of the tributaries contribute significant heavy metal load, but around urban areas in Yamuna (tributary of Ganges), very high levels due to the distribution from the drainage network are observed. Compared to the Brahmaputra, the distribution and fractionation of heavy metals in the Ganges sediments are more erratic and highly variable. All the metals considered show high correlation among themselves. Given the high flux of suspended sediments from the Himalayan rivers (nearly 20% of the global flux), the worldwide budget for heavy metal transport may need to be suitable revised.

  14. CryoSat-2 altimetry for river level monitoring - Evaluation in the Ganges-Brahmaputra River basin

    DEFF Research Database (Denmark)

    Villadsen, Heidi; Andersen, Ole B.; Stenseng, Lars;

    2015-01-01

    The performance of CryoSat-2/SIRAL altimetty for river level monitoring is investigated by using river levels retrieved from Ganges and Brahmaputra. A key concern for the CryoSat-2 orbit has been its long repeat period of 369 days, which is usually undesirable for river and lake monitoring. However......, the results from the method developed in this study involving virtual stations show that the CryoSat-2 data can indeed be used for such monitoring by utilizing the high spatial coverage and the sub-cycle period of 30 days. The results show that it is possible to capture the peak flow occurring during late...... summer due to monsoonal precipitation and the melting of snow in the Himalayas. The evaluation of ClyoSat-2 river levels is performed by comparing with Envisat data in terms of annual signals and amplitudes. The obtained annual amplitudes agree well with the Envisat data, although CryoSat-2 exhibit...

  15. Major ion chemistry of the Ganga-Brahmaputra river system: Weathering processes and fluxes to the Bay of Bengal

    Energy Technology Data Exchange (ETDEWEB)

    Sarin, M.M.; Krishnaswami, S.; Dilli, K.; Somayajulu, B.L.K. (Physical Research Laboratory, Ahmedabad (India)); Moore, W.S. (Univ. of South Carolina (USA))

    1989-05-01

    The Ganga-Brahmaputra, one of the worlds's largest river systems, is first in terms of sediment transport and fourth in terms of water discharge. A detailed and systematic study of the major ion chemistry of these rivers and their tributaries, as well as the clay mineral composition of the bed sediments has been conducted. The chemistry of the highland rivers are all dominated by carbonate weathering; (Ca + Mg) and HCO{sub 3} account for about 80% of the cations and anions. In the lowland rivers, HCO{sub 3} excess over (Ca + Mg) and a relatively high contribution of (Na + K) to the total cations indicate that silicate weathering and/or contributions from alkaline/saline soils and ground waters could be important sources of major ions to these waters. The chemistry of the Ganga and the Yamuna in the lower reaches is by and large dictated by the chemistry of their tributaries and their mixing proportions. The highland rivers weather acidic rocks, whereas the others flow initially through basic effusives. The Ganga-Brahmaputra river system transports about 130 million tons of dissolved salts to the Bay of Bengal, which is nearly 3% of the global river flux to the oceans. The chemical denudation rates for the Ganga and the Brahmaputra basins are about 72 and 105 tons{center dot}km{sup {minus}2}{center dot}yr{sup {minus}1}, respectively, which are factors of 2 to 3 higher than the global average. The high denudation rate, particularly in the Brahmaputra, is attributable to high relief and heavy rainfall.

  16. Sediment transport in an active erodible channel bend of Brahmaputra river

    Indian Academy of Sciences (India)

    Tapas Karmaker; Y Ramprasad; Subashisa Dutta

    2010-12-01

    Spatial variation of sediment transport in an alluvial sand-bed river bend needs to be understood with its influencing factors such as bank erosion, secondary current formation, land spur and bed-material characteristics. In this study, detailed hydrographic surveys with Acoustic Doppler Current Profiler (ADCP) were conducted at an active erodible river bend to measure suspended load, velocity, bathymetric profile and characteristics of the bed material. Study indicates the presence of multi-thread flow in the channel bend. Local variation of sediment transport is primarily controlled by active bank erosion, land spur and sand bar formation. Vertical distribution of suspended sediment concentration follows a power function with normalized depth. Average bed-material concentration at the reach level is computed from observed sediment profiles, and is compared against various sediment transport functions. Results show that the sediment transport function suggested by Yang gives better predictions for this reach. Transverse bed slopes at critical survey transects were computed from the bathymetric data and evaluated with analytical approaches. Out of three analytical approaches used, Odgaard’s approach estimates the bed slopes fairly close to the observed one. These two functions are suitable in the Brahmaputra river for further morphological studies.

  17. A statistical comparison of four precipitation climate datasets in the Ganges-Brahmaputra-Meghna River basin

    Science.gov (United States)

    Brenton, James

    There are 630 million people that live within the Ganges-Brahmaputra-Meghna River basin (GBM) who depend on these rivers for their livelihood (Frenken, 2011). These rivers greatly depend upon the precipitation and rain fall to contribute to their flows. Researchers and end-users in the GBM basin depend on climate precipitation datasets to help them study the impact precipitation has the hydrology and agricultural. To properly utilize a dataset, the source input data, the algorithms used to merge the data, and the final temporal and spatial resolution of the dataset all need to be properly understood. The goal for this study is to statistically compare four climate precipitation datasets, GPCP, CMAP, CHIRPS and APHRODITE, in the GBM basin to identify significant differences among them. Their respective data will be compared and, the evaluations will be shared with the SERVIR science team and the hydrologists at ICIMOD. Then, SERVIR and ICIMOD can better aid decision makers in the GBM Basin by improving their knowledge and interpretation of precipitation datasets and how it will affect the people of the GBM Basin.

  18. Satellite altimeter-derived monthly discharge of the Ganga-Brahmaputra River and its seasonal to interannual variations from 1993 to 2008

    OpenAIRE

    Papa, Fabrice; Durand, Fabien; Rossow, William B.; Rahman, Altiqur; Bala, Sujit

    2010-01-01

    The Ganga-Brahmaputra accounts for similar to 25% of the total amount of freshwater received by the Bay of Bengal. Using daily in situ river discharge data along with altimetry-derived river heights, the present study aims to produce a monthly data set of altimetry-derived Ganga-Brahmaputra River discharge at the river mouths for 1993-2008. First, we estimate the standard error of ENVISAT-derived water levels over the Ganga to be 0.26 m, much smaller than the range of variability of similar t...

  19. Regional climate projections in two alpine river basins: Upper Danube and Upper Brahmaputra

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    Dobler, A.; Yaoming, M.; Sharma, N.; Kienberger, S.; Ahrens, B.

    2011-04-01

    Projections from coarse-grid global circulation models are not suitable for regional estimates of water balance or trends of extreme precipitation and temperature, especially not in complex terrain. Thus, downscaling of global to regionally resolved projections is necessary to provide input to integrated water resources management approaches for river basins like the Upper Danube River Basin (UDRB) and the Upper Brahmaputra River Basin (UBRB). This paper discusses the application of the regional climate model COSMO-CLM as a dynamical downscaling tool. To provide accurate data the COSMO-CLM model output was post-processed by statistical means. This downscaling chain performs well in the baseline period 1971 to 2000. However, COSMO-CLM performs better in the UDRB than in the UBRB because of a longer application experience and a less complex climate in Europe. Different climate change scenarios were downscaled for the time period 1960-2100. The projections show an increase of temperature in both basins and for all seasons. The values are generally higher in the UBRB with the highest values occurring in the region of the Tibetan Plateau. Annual precipitation shows no substantial change. However, seasonal amounts show clear trends, for instance an increasing amount of spring precipitation in the UDRB. Again, the largest trends for different precipitation statistics are projected in the region of the Tibetan Plateau. Here, the projections show up to 50% longer dry periods in the months June to September with a simultaneous increase of about 10% for the maximum amount of precipitation on five consecutive days. For the Assam region in India, the projections also show an increase of 25% in the number of consecutive dry days during the monsoon season leading to prolonged monsoon breaks.

  20. Chemical weathering and arsenic enrichment in aquifer of Brahmaputra River Basin, India, adjoining Eastern Himalayas

    Science.gov (United States)

    Verma, Swati; Mukherjee, Abhijit; Mahanta, Chandan; Choudhury, Runti

    2016-04-01

    Arsenic (As) enrichment in the shallow aquifers of Brahmaputra river basin (BRB), mostly located in the Indian state of Assam, has not been known for a long time. So far, very limited number of studies has been done to understand the geological and geochemical processes controlling groundwater chemistry and evolution in the BRB. The present study interprets the groundwater solute chemistry, hydrogeochemical evolution, As enrichment and aquifer characterization in BRB with special reference to two geologically distinct regions in upper Assam, India. These regions consist of the northern (N) region (located along the Eastern Himalayas) and southern (S) region (near Indo-Burma Range) of the Brahmaputra basin which shows distinct tectonic settings and sediments provinces in the Himalayas orogenic belt. Shallow alluvial aquifers of the northern part are mainly composed of grey/brown sand (fine, medium and course) and light grey clay however aquifers of southern part mainly composed of black/dark grey clay and fine grey sands. Aquifers of S-region are severely contaminated with dissolved As (maximum 0.45 mg/L) in comparison to the northern aquifers (maximum: 0.18 mg/L). However, both areas have similar reducing, postoxic environments with high concentrations of total organic carbon (TOC), and saturation index calculations suggest that As is liberated primarily by reductive dissolution of metal oxides. Major mineralogical compositions of the aquifer sediments analysed by FESEM/EDX, XRD and thin section which indicate the major presence of Fe-oxide and oxyhydroxides, mica (muscovite and biotite), feldspar, pyroxene, abundance of quartz and some clay minerals whereas clay highly present in sediments of S-aquifers. The major-ion composition shows that groundwater composition is mainly Ca2+-HCO3‑ and Ca2+-Na+-HCO3 in N-region while S-region part is dominated by Na+-Ca2+-HCO3‑ hydrochemical facies. Molar ratios and thermodynamic calculations show that groundwater

  1. Local Economic Development and Hydropower Along the Brahmaputra River Basin in Northeast India

    Science.gov (United States)

    Mock, A.

    2014-12-01

    Large dams have long been controversial. They offer benefits, such as reduced greenhouse gas emissions, energy security, and local development, yet produce negative social and ecological impact, such as wildlife habitat destruction, human displacement, and the disruption of downstream fishing or agricultural industries. In the past decade, the Indian government has signed Memoranda of Understanding with hydroelectric power companies for the building of over 130 large dams on the Brahmaputra River in the state of Arunachal Pradesh in Northeast India. These dams can generate 43% of India's assessed hydropower potential to sustain India's growing economy. In addition, the Indian government claims that these dams will bring local development with needed jobs. However, local Arunachali people have protested and temporarily halted hydropower projects because of the impact of dams on their existing livelihoods. Using the North Eastern Electric Power Corporation's (NEEPCO) Ranganadi Hydroelectric Project as a case study, our project examined whether dams in Northeast India provide jobs for local people, and whether distance from the dam or work colony to a worker's hometown affects the type of job the worker received. Survey data from residents at NEEPCO's work colony in Doimukh, Arunachal Pradesh, was analyzed using SPSS (n = 18). Our research found that 100% of workers at the dam originally resided in Northeast India, with 33% from Arunachal Pradesh, and 67% from the nearby states of Assam, and Tripura. Further, our analysis revealed no statistically significant relationship between the distance to a worker's hometown and job type (p = .609). Where workers come from did not affect the type of job they received. More research using a larger sample size and additional hydroelectric project case studies is needed to further explore the relationship between worker home location and their job types.

  2. LENGTH-WEIGHT RELATIONSHIP AND CONDITION FACTOR OF Aorichthys aor (HAMILTON-BUCHANAN) IN LOWER REACHES OF RIVER BRAHMAPUTRA

    OpenAIRE

    Sarma, D.; J. Das; A. Dutta

    2012-01-01

    The studies were conducted during 2008–2010 to evaluate length-weight relationship and condition factor of Aorichthys aor in lower reaches of River Brahmaputra. 750 nos of fishes having weight of 20g to 1250 g and total length of 10 cm to 55 cm were recorded. The Cube law or Length–weight relationship was calculated as W = 0.00352 L3.246. The coefficient of correlation (r) between observed length & weight and calculated length & weight was 0.96 and 0.93 respectively, which indicated highly si...

  3. Integrated water resources management. Constraints and opportunities with a focus on the Ganges and the Brahmaputra river basins

    Energy Technology Data Exchange (ETDEWEB)

    Rahaman, M.M.

    2009-07-01

    The key aims of this thesis are to identify the constraints and opportunities of implementing the integrated water resources management (IWRM) concept at both the policy and field level. IWRM has been chosen as a focus of this study as all contemporary international conferences, summits, regional water policies and declarations promote the IWRM concept for the effective and efficient management of water resources. The thesis has two parts. The first part reviews the evolution of the IWRM concept and the principles that have been developed at international conferences over the last three decades. Through two case studies on the EU Water Framework Directive (2000) and the Fourth World Water Forum's Ministerial Declaration (2006), an attempt is made to analyse the current implementation status of IWRM principles in practice. The findings suggest that existing policies tend to take a rather narrow view of the concept and have largely failed to incorporate the principles. This part also identifies the seven future challenges in implementing IWRM in practice. Water resources management is multidimensional in nature. In transboundary river basins, implementing the IWRM concept is even more complex as it involves more than one sovereign nation sharing the same water. The second part of the thesis focuses on implementation of IWRM in the transboundary river basin context. This part provides indepth analyses focusing on the integrated management of the Ganges and Brahmaputra river basins that are shared by China, Nepal, Bhutan, India and Bangladesh. It identifies the various dimensions of water conflict among the riparian countries and their views on integrated management of the basins. It analyzes the existing bilateral treaties between the riparian countries and identifies the constraints and benefits of integrated water management along the basins. Practical recommendations for the integrated management of the Ganges and Brahmaputra basins are formulated. The

  4. Ecosystem diversity of Cladocera (Crustacea: Branchiopoda of the floodplain lakes of Majuli River Island, the Brahmaputra river basin, northeast India

    Directory of Open Access Journals (Sweden)

    Bhushan Kumar Sharma

    2015-02-01

    Full Text Available Plankton and semi-plankton samples collected from twelve floodplain lakes (beels of Majuli River Island of the Brahmaputra river basin, Upper Assam reveal rich Cladocera assemblage of 48 species belonging to 32 genera and 7 families. This report assumes biodiversity value as ~65.0% and ~37.0% of the species, and ~78.0% and ~72.0 of genera of the taxon known from Assam state of northeast India (NEI and India, respectively. Picripleuroxus quasidenticulatus (Smirnov is a new record from the Indian sub-region. Biogeographically important elements include one Australasian, three Indo-Chinese and two Oriental species. Total cladoceran richness in individual beels ranged between 16-38 (26 ± 6 species while monthly and seasonal richness in six beels each varied between 8 ± 3-13 ± 3 species and 11 ± 4-17 ± 3 species, respectively and showed lack of any pattern of temporal variations. The community similarities (40.1-86.5% vide Sørensen’s index and the hierarchical cluster analysis affirm heterogeneity in Cladocera composition in different beels. Individual abiotic factors indicated insignificant influence on richness except for significant positive correlation with alkalinity only in Khorkhoria beel.

  5. Exploring the influence of precipitation extremes and human water use on total water storage (TWS) changes in the Ganges-Brahmaputra-Meghna River Basin

    Science.gov (United States)

    Khandu; Forootan, Ehsan; Schumacher, Maike; Awange, Joseph L.; Müller Schmied, Hannes

    2016-03-01

    Climate extremes such as droughts and intense rainfall events are expected to strongly influence global/regional water resources in addition to the growing demands for freshwater. This study examines the impacts of precipitation extremes and human water usage on total water storage (TWS) over the Ganges-Brahmaputra-Meghna (GBM) River Basin in South Asia. Monthly TWS changes derived from the Gravity Recovery And Climate Experiment (GRACE) (2002-2014) and soil moisture from three reanalyses (1979-2014) are used to estimate new extreme indices. These indices are applied in conjunction with standardized precipitation indices (SPI) to explore the impacts of precipitation extremes on TWS in the region. The results indicate that although long-term precipitation do not indicate any significant trends over the two subbasins (Ganges and Brahmaputra-Meghna), there is significant decline in rainfall (9.0 ± 4.0 mm/decade) over the Brahmaputra-Meghna River Basin from 1998 to 2014. Both river basins exhibit a rapid decline of TWS from 2002 to 2014 (Ganges: 12.2 ± 3.4 km3/yr and Brahmaputra-Meghna: 9.1 ± 2.7 km3/yr). While the Ganges River Basin has been regaining TWS (5.4 ± 2.2 km3/yr) from 2010 onward, the Brahmaputra-Meghna River Basin exhibits a further decline (13.0 ± 3.2 km3/yr) in TWS from 2011 onward. The impact of human water consumption on TWS appears to be considerably higher in Ganges compared to Brahmaputra-Meghna, where it is mainly concentrated over Bangladesh. The interannual water storage dynamics are found to be strongly associated with meteorological forcing data such as precipitation. In particular, extreme drought conditions, such as those of 2006 and 2009, had profound negative impacts on the TWS, where groundwater resources are already being unsustainably exploited.

  6. Spatial distribution of persistent organic pollutants in the surface water of River Brahmaputra and River Ganga in India.

    Science.gov (United States)

    Chakraborty, Paromita; Sakthivel, S; Kumar, Bhupander; Kumar, Sanjay; Mishra, Meenu; Verma, V K; Gaur, Richa

    2014-01-01

    Persistent organic pollutants (POPs) like organochlorine pesticides (OCPs), polychlorinated biphenyles (PCBs) and polyaromatic hydrocarbons (PAHs) are discharged in surface water by various point and nonpoint sources thereby degrading the functioning of the ecosystem and threatening human health. Chlorinated pesticides such as Hexachlorocyclohexane (HCHs) and Dichlorodiphenyltrichloroethane (DDTs) are effective pest control chemicals, used in agriculture and public health activities (malaria eradication, etc.) in India for the past several decades and are still in use. POPs can cause endocrine disruption and food chain biomagnification because of their lipophilicity and environmental persistence. This study aims to assess the environmental occurrence and spatial distribution of OCPs, PAHs and PCBs in the surface water of River Brahmaputra and Ganga ending at the of the Bay of Bengal.The order of organochlorine pesticides is as: heptachlor>HCHs>DDTs>dieldrin>aldrin>endosulfan. Diamond Harbour and Bakkhali were the two places with elevated level of all individual HCH isomers compared to all other sites. β-Endosulfan and α-Endosulfan were high at Dibrugarh than other sampling sites. This is due to the ongoing use of Endosulfan in the tea estates in Assam especially the estates close to the town of Dibrugarh. p,p'-DDT and o,p'-DDT levels indicate the fresh input of DDT in all the sampling sites. Heptachlor has been observed in 57% of the total samples reported in the present study.These reasons may attribute to high deposition of pesticides in the surface water of Ganga and Brahmaputra.In addition the catchments area of the Ganga River is surrounded by agricultural lands so a relatively higher residue of pesticides was prevalent. Σ27 PCBs varied from BDL to 142 (Avg±SD, 3.96±6.71) ng L-1. PCB-18, PCB-52 & PCB-44 showed the highest concentration levels for all the sampling sites. PCB-126 was observed in samples taken from sites close to the city limit of Kolkata

  7. Spatial distribution of persistent organic pollutants in the surface water of River Brahmaputra and River Ganga in India.

    Science.gov (United States)

    Chakraborty, Paromita; Sakthivel, S; Kumar, Bhupander; Kumar, Sanjay; Mishra, Meenu; Verma, V K; Gaur, Richa

    2014-01-01

    Persistent organic pollutants (POPs) like organochlorine pesticides (OCPs), polychlorinated biphenyles (PCBs) and polyaromatic hydrocarbons (PAHs) are discharged in surface water by various point and nonpoint sources thereby degrading the functioning of the ecosystem and threatening human health. Chlorinated pesticides such as Hexachlorocyclohexane (HCHs) and Dichlorodiphenyltrichloroethane (DDTs) are effective pest control chemicals, used in agriculture and public health activities (malaria eradication, etc.) in India for the past several decades and are still in use. POPs can cause endocrine disruption and food chain biomagnification because of their lipophilicity and environmental persistence. This study aims to assess the environmental occurrence and spatial distribution of OCPs, PAHs and PCBs in the surface water of River Brahmaputra and Ganga ending at the of the Bay of Bengal.The order of organochlorine pesticides is as: heptachlor>HCHs>DDTs>dieldrin>aldrin>endosulfan. Diamond Harbour and Bakkhali were the two places with elevated level of all individual HCH isomers compared to all other sites. β-Endosulfan and α-Endosulfan were high at Dibrugarh than other sampling sites. This is due to the ongoing use of Endosulfan in the tea estates in Assam especially the estates close to the town of Dibrugarh. p,p'-DDT and o,p'-DDT levels indicate the fresh input of DDT in all the sampling sites. Heptachlor has been observed in 57% of the total samples reported in the present study.These reasons may attribute to high deposition of pesticides in the surface water of Ganga and Brahmaputra.In addition the catchments area of the Ganga River is surrounded by agricultural lands so a relatively higher residue of pesticides was prevalent. Σ27 PCBs varied from BDL to 142 (Avg±SD, 3.96±6.71) ng L-1. PCB-18, PCB-52 & PCB-44 showed the highest concentration levels for all the sampling sites. PCB-126 was observed in samples taken from sites close to the city limit of Kolkata

  8. Assimilation of CryoSat-2 altimetry to a hydrodynamic model of the Brahmaputra river

    Science.gov (United States)

    Schneider, Raphael; Nygaard Godiksen, Peter; Ridler, Marc-Etienne; Madsen, Henrik; Bauer-Gottwein, Peter

    2016-04-01

    Remote sensing provides valuable data for parameterization and updating of hydrological models, for example water level measurements of inland water bodies from satellite radar altimeters. Satellite altimetry data from repeat-orbit missions such as Envisat, ERS or Jason has been used in many studies, also synthetic wide-swath altimetry data as expected from the SWOT mission. This study is one of the first hydrologic applications of altimetry data from a drifting orbit satellite mission, namely CryoSat-2. CryoSat-2 is equipped with the SIRAL instrument, a new type of radar altimeter similar to SRAL on Sentinel-3. CryoSat-2 SARIn level 2 data is used to improve a 1D hydrodynamic model of the Brahmaputra river basin in South Asia set up in the DHI MIKE 11 software. CryoSat-2 water levels were extracted over river masks derived from Landsat imagery. After discharge calibration, simulated water levels were fitted to the CryoSat-2 data along the Assam valley by adapting cross section shapes and datums. The resulting hydrodynamic model shows accurate spatio-temporal representation of water levels, which is a prerequisite for real-time model updating by assimilation of CryoSat-2 altimetry or multi-mission data in general. For this task, a data assimilation framework has been developed and linked with the MIKE 11 model. It is a flexible framework that can assimilate water level data which are arbitrarily distributed in time and space. Different types of error models, data assimilation methods, etc. can easily be used and tested. Furthermore, it is not only possible to update the water level of the hydrodynamic model, but also the states of the rainfall-runoff models providing the forcing of the hydrodynamic model. The setup has been used to assimilate CryoSat-2 observations over the Assam valley for the years 2010 to 2013. Different data assimilation methods and localizations were tested, together with different model error representations. Furthermore, the impact of

  9. Groundwater arsenic contamination in Brahmaputra river basin: a water quality assessment in Golaghat (Assam), India.

    Science.gov (United States)

    Chetia, Mridul; Chatterjee, Soumya; Banerjee, Saumen; Nath, Manash J; Singh, Lokendra; Srivastava, Ravi B; Sarma, Hari P

    2011-02-01

    Distribution of arsenic (As) and its compound and related toxicology are serious concerns nowadays. Millions of individuals worldwide are suffering from arsenic toxic effect due to drinking of As-contaminated groundwater. The Bengal delta plain, which is formed by the Ganga-Padma-Meghna-Brahmaputra river basin, covering several districts of West Bengal, India, and Bangladesh is considered as the worst As-affected alluvial basin. The present study was carried out to examine As contamination in the state of Assam, an adjoining region of the West Bengal and Bangladesh borders. Two hundred twenty-two groundwater samples were collected from shallow and deep tubewells of six blocks of Golaghat district (Assam). Along with total As, examination of concentration levels of other key parameters, viz., Fe, Mn, Ca, Na, K, and Mg with pH, total hardness, and SO[Formula: see text], was also carried out. In respect to the permissible limit formulated by the World Health Organization (WHO; As 0.01 ppm, Fe 1.0 ppm, and Mn 0.3 ppm for potable water), the present study showed that out of the 222 groundwater samples, 67%, 76.4%, and 28.5% were found contaminated with higher metal contents (for total As, Fe, and Mn, respectively). The most badly affected area was the Gamariguri block, where 100% of the samples had As and Fe concentrations above the WHO drinking water guideline values. In this block, the highest As and Fe concentrations were recorded 0.128 and 5.9 ppm, respectively. Tubewell water of depth 180±10 ft found to be more contaminated by As and Fe with 78% and 83% of the samples were tainted with higher concentration of such toxic metals, respectively. A strong significant correlation was observed between As and Fe (0.697 at p<0.01), suggesting a possible reductive dissolution of As-Fe-bearing minerals for the mobilization of As in the groundwater of the region. PMID:20224855

  10. LENGTH-WEIGHT RELATIONSHIP AND CONDITION FACTOR OF Aorichthys aor (HAMILTON-BUCHANAN IN LOWER REACHES OF RIVER BRAHMAPUTRA

    Directory of Open Access Journals (Sweden)

    D. Sarma

    2012-12-01

    Full Text Available The studies were conducted during 2008–2010 to evaluate length-weight relationship and condition factor of Aorichthys aor in lower reaches of River Brahmaputra. 750 nos of fishes having weight of 20g to 1250 g and total length of 10 cm to 55 cm were recorded. The Cube law or Length–weight relationship was calculated as W = 0.00352 L3.246. The coefficient of correlation (r between observed length & weight and calculated length & weight was 0.96 and 0.93 respectively, which indicated highly significant relationship between length and weight. The exponent (b value obtained indicating the positive allometric growth pattern. The relative condition factor (Kn value was found higher in fishes of above 650 g weight groups.

  11. Additional record of Batasio merianiensis (Chaudhuri 1913, a catfish (Teleostei: Bagridae in upper Brahmaputra River drainage in Arunachal Pradesh, India

    Directory of Open Access Journals (Sweden)

    L. Tamang

    2014-05-01

    Full Text Available This paper communicates the extension of the distribution range of Batasio merianiensis in Sille River in the upper Brahmaputra drainage, East Siang District, Arunachal Pradesh. Detailed examinations of the specimens revealed existence of few morphological variations against those reported by Heok Hee Ng in 2009 on the following characteristics: by having a longer preanal (70.4-73.4 vs. 66.3-68.2% SL; a longer prepectoral (25.1-29.3 vs. 21.4-25.7% SL; a longer adipose-fin base (22.0-27.6 vs. 16.9-22.2% SL; a shorter post-adipose distance (11.6-13.4 vs.13.4-15.5% SL; a deeper body at anus (depth 18.3-20.8 vs.15.2-18.4% SL and broader head (width 17.6-20.0 vs.13.5-16.2 % HL. Few additional characters of the fish are included along with brief information on its habitat. The LIPUM, the semi-traditional method of fishing in the river is identified as a major threat to this species.

  12. Dissolved and solid-phase arsenic fate in an arsenic-enriched aquifer in the river Brahmaputra alluvial plain.

    Science.gov (United States)

    Baviskar, Shirishkumar; Choudhury, Runti; Mahanta, Chandan

    2015-03-01

    Dissolved arsenic mobility in the environment is controlled by its associations with solid-phase As and other minerals by chemodynamics of adsorptions and co-precipitation. Arsenic mobilization potential and mechanisms in the groundwater of a part of the river Brahmaputra alluvial plain in India were inferred from aqueous and solid-phase geochemical analyses of groundwater samples and sediment cores from various depths. Sediments were analyzed for key parameters, e.g., total and sequentially extracted Fe, As, and Mn; organic carbon content; carbonate phases; and specific surface area, while groundwater samples collected from close proximity of the drilled bore well were analyzed for major and trace element hydrogeochemistry. Result shows Mn- and Fe-oxyhydroxides as the major leachable As solid phases. Median total leachable solid-phase As was found to be ~9.50 mg/kg, while groundwater As ranged between 0.05 and 0.44 mg/L from adjoining water wells. Morphological and mineralogical studies of the aquifer sediments conducted using scanning electronic microscope energy-dispersive X-ray (SEM-EDX) and X-ray diffraction (XRD) analysis indicate the major presence of Fe- and Mn-oxyhydroxides. Sequential leaching experiments along with the mineralogical studies suggest that bacterially mediated, reductive dissolution of MnOOH and FeOOH is probably an important mechanism for releasing As into the groundwater from the sediments. PMID:25663398

  13. Valley of the Brahmaputra, India

    Science.gov (United States)

    2002-01-01

    In this true-color MODIS image from October 23, 2001, the semi-arid Tibetan Plateau (upper left) meets up with the Himalayas to the south. From the heights of the Himalayas, snow-covered on their northern flanks, and lush with vegetation to the south, numerous rivers, brown with churned up sediment, flow into the valley of the Brahmaputra River in Assam, India. The Brahmaputra turns southward at the border of Bangladesh and is soon joined by the Ganges River, flowing in from image left. The mighty river splits into numerous channels as it runs out toward the Bay of Bengal, giving the region the name 'Mouths of the Ganges.' Vast amounts of sediment are being emptied into the Bay by the river, and greenish blue swirls could be a mixture of sediment and phytoplankton. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

  14. Ganga-Brahmaputra river discharge from Jason-2 radar altimetry: An update to the long-term satellite-derived estimates of continental freshwater forcing flux into the Bay of Bengal

    Science.gov (United States)

    Papa, Fabrice; Bala, Sujit K.; Pandey, Rajesh K.; Durand, Fabien; Gopalakrishna, V. V.; Rahman, Atiqur; Rossow, William B.

    2012-11-01

    This paper discusses the use of Jason-2 radar altimeter measurements to estimate the Ganga-Brahmaputra surface freshwater flux into the Bay of Bengal for the period mid-2008 to December 2011. A previous estimate was generated for 1993-2008 using TOPEX-Poseidon, ERS-2 and ENVISAT, and is now extended using Jason-2. To take full advantages of the new availability of in situ rating curves, the processing scheme is adapted and the adjustments of the methodology are discussed here. First, using a large sample of in situ river height measurements, we estimate the standard error of Jason-2-derived water levels over the Ganga and the Brahmaputra to be respectively of 0.28 m and 0.19 m, or less than ˜4% of the annual peak-to-peak variations of these two rivers. Using the in situ rating curves between water levels and river discharges, we show that Jason-2 accurately infers Ganga and Brahmaputra instantaneous discharges for 2008-2011 with mean errors ranging from ˜2180 m3/s (6.5%) over the Brahmaputra to ˜1458 m3/s (13%) over the Ganga. The combined Ganga-Brahmaputra monthly discharges meet the requirements of acceptable accuracy (15-20%) with a mean error of ˜16% for 2009-2011 and ˜17% for 1993-2011. The Ganga-Brahmaputra monthly discharge at the river mouths is then presented, showing a marked interannual variability with a standard deviation of ˜12500 m3/s, much larger than the data set uncertainty. Finally, using in situ sea surface salinity observations, we illustrate the possible impact of extreme continental freshwater discharge event on the northern Bay of Bengal as observed in 2008.

  15. Ganga-Brahmaputra river discharge from Jason-2 radar altimetry: An update to the long-term satellite-derived estimates of continental freshwater forcing flux into the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Papa, F.; Bala, S.K.; Pandey, R.K.; Durand, F.; Gopalakrishna, V.V.; Rahman, A.; Rossow, W.B.

    large sample of in situ river height measurements, we estimate the standard error of Jason-2-derived water levels over the Ganga and the Brahmaputra to be respectively of 0.28 m and 0.19 m, or less than approx 4 percent of the annual peak...

  16. Distribution and fractionation of heavy metals in the surface sediments of the Ganges-Brahmaputra-Meghna river system in the Bengal basin

    Energy Technology Data Exchange (ETDEWEB)

    Datta, D.K. [Khulna Univ. (Bangladesh). Dept. of Environmental Sciences; Subramanian, V. [Jawaharlal Nehru Univ., New Delhi (India). School of Environmental Sciences

    1998-11-01

    The lower Ganges-Brahmaputra-Meghna (G-B-M) drainage basin occupies the total Bengal Basin, which is one of the unique basins of the world because of its location and size, density of population, and catastrophic deposition of sediments. The increased heavy metal concentration in the 63 m fraction of surface sediments shows similarity among major segments of the G-B-M system in the basin, which reflects the homogenization of lithologic and chemical diversity of the greater denudation regime by the river processes. The differences in heavy metal concentration in the lower G-B-M system with that of its upper and middle counterpart is mainly related to the contrast between Himalayan rivers and the other major South Asian rivers, and may be due to the geological differences of their denudation regime. Heavy metals in the Lower G-B-M system have an affinity towards the clay fraction of the sediments. The correlation matrix of heavy metals in the lower Brahmaputra and Meghna suggests the importance of Fe-Mn oxyhydroxides in their accumulations. Iron, Ti and Mn are higher in the Meghna main channel, Zn is higher in the Meghna tributaries, and Cr is higher in both the Brahmaputra and Meghna compared to the value for standard shale. The enrichment factor is {<=}1 for most of the metals except Mn which is relatively higher in the Meghna and lower Ganges main channels. The geoaccumulation index (I{sub geo}) for most of the heavy metals lies below grade zero, suggesting unpolluted sediment quality. The lower Ganges system shows relatively higher concentration in the nondetrital fraction of heavy metals, probably due to the presence of petroleum refinery, industrial and mining effluents, and agricultural runoff in the drainage basin. The relative uniformity in concentration of heavy metals in vertical profiles may be due to the uniformity in sediment grain size and catastrophic deposition of sediments, where the time period represented by the vertical sediment column is not

  17. Chemistry of uranium, thorium, and radium isotopes in the Ganga-Brahmaputra river system: Weathering processes and fluxes to the Bay of Bengal

    Energy Technology Data Exchange (ETDEWEB)

    Sarin, M.M.; Krishnaswami, S.; Somayajulu, B.L.K. (Physical Research Laboratory, Ahmedabad (India)); Moore, W.S. (Univ. of South Carolina, Columbia (USA))

    1990-05-01

    Rivers are the major pathways for the transport of weathered materials from the land to the oceans. The geochemical studies on river waters provide an insight into the weathering processes that control the distribution of elements in dissolved and particulate phases and their fluxes to the estuaries. Consequently, a detailed and systematic study of the major ion composition and radionuclide abundances in the dissolved and suspended phases of the Ganga-Brahmaputra rivers was undertaken during 1982-83. We present here data on the dissolved uranium and radium isotopes in these river waters and on some of the U-Th decay series nuclides in the suspended sediments. Prior to this work, Bhat and Krishnaswami (1969) have reported the downstream and seasonal variations in the concentration of dissolved uranium and radium isotopes in the Ganga main stream. The primary objective of our study is to identify the parameters controlling the supply of uranium and radium isotopes to these river waters during weathering, and to determine their fluxes to the estuaries. The results presented in this paper represent the most comprehensive data set on uranium and radium isotopes yet published for a major river system.

  18. Discussion: ´Changing river courses in the western part of the Ganga-Brahmaputra delta' by Kalyan Rudra (2014), Geomorphology, 227, 87-100

    Science.gov (United States)

    Bandyopadhyay, Sunando; Das, Sayantan; Kar, Nabendu Sekhar

    2015-12-01

    Rudra (2014, Geomorphology, 227, 87-100) presented a review of geomorphic changes of the Indian part of the Ganga-Brahmaputra delta (GBD) during the last ~ 240 years, emphasising deterioration of distributary channels, effects of discharge augmentation from the Farakka barrage project into the Bhagirathi-Hugli river and the patterns of coastal erosion. The work contained many inconsistencies, improper understanding, and misrepresentation of facts. The principal of these involved (1) usage of nomenclature like GBD, Bengal basin, and their delineation; (2) discussions made on evolution and current status of the deltaic distributaries; and (3) generation and presentation of data on discharge, tides, and sea level. Besides this, most figures of the work contained positional inaccuracies and/or errors in survey years. We systematically addressed all these issues in the present discussion and offered corrected and up-to-date information wherever applicable.

  19. Impacts of climate change and socio-economic scenarios on flow and water quality of the Ganges, Brahmaputra and Meghna (GBM) river systems: low flow and flood statistics.

    Science.gov (United States)

    Whitehead, P G; Barbour, E; Futter, M N; Sarkar, S; Rodda, H; Caesar, J; Butterfield, D; Jin, L; Sinha, R; Nicholls, R; Salehin, M

    2015-06-01

    The potential impacts of climate change and socio-economic change on flow and water quality in rivers worldwide is a key area of interest. The Ganges-Brahmaputra-Meghna (GBM) is one of the largest river basins in the world serving a population of over 650 million, and is of vital concern to India and Bangladesh as it provides fresh water for people, agriculture, industry, conservation and for the delta system downstream. This paper seeks to assess future changes in flow and water quality utilising a modelling approach as a means of assessment in a very complex system. The INCA-N model has been applied to the Ganges, Brahmaputra and Meghna river systems to simulate flow and water quality along the rivers under a range of future climate conditions. Three model realisations of the Met Office Hadley Centre global and regional climate models were selected from 17 perturbed model runs to evaluate a range of potential futures in climate. In addition, the models have also been evaluated using socio-economic scenarios, comprising (1) a business as usual future, (2) a more sustainable future, and (3) a less sustainable future. Model results for the 2050s and the 2090s indicate a significant increase in monsoon flows under the future climates, with enhanced flood potential. Low flows are predicted to fall with extended drought periods, which could have impacts on water and sediment supply, irrigated agriculture and saline intrusion. In contrast, the socio-economic changes had relatively little impact on flows, except under the low flow regimes where increased irrigation could further reduce water availability. However, should large scale water transfers upstream of Bangladesh be constructed, these have the potential to reduce flows and divert water away from the delta region depending on the volume and timing of the transfers. This could have significant implications for the delta in terms of saline intrusion, water supply, agriculture and maintaining crucial ecosystems such

  20. Rotifer assemblages (Rotifera: Eurotatoria of the floodplain lakes of Majuli River Island, the Brahmaputra river basin, northeast India

    Directory of Open Access Journals (Sweden)

    Bhushan Kumar Sharma

    2014-12-01

    Full Text Available Our plankton and semi-plankton collections from twelve floodplain lakes (beels of Majuli River Island, Upper Assam reveal 124 rotifer species (32 genera and 17 families; these merit biodiversity value as ~52.0% and ~30.0% of species, ~68.0 and ~45.0% of  genera and ~74.0 and ~65.0% of the families of the Phylum known from northeast India (NEI and India, respectively. Two species are new to India with Trichocerca uncinata as new record to the Oriental region.  Eleven species are new to the study area and we provide an updated list (144 species for following meta-analyses of Majuli Rotifera. Biogeographically important elements include one Australasian, four Oriental, four Palaeotropical and one cosmo (sub tropical species while several species are of regional distribution interest. The rotifer fauna is predominantly tropical and Lecanidae > Lepadellidae collectively include ~53.0% species but it records paucity of Brachionus species. Individual beels record total richness of 60-100 (77 ± 12 species, monthly richness between 24 ± 7-34 ± 7 species and maximum up to 54 species/sample. The results are characterized by high community similarities (59.7-90.4% vide Sørensen’s index, more rotifer homogeneity amongst beels, lack of any pattern of temporal richness variations and much limited influence of abiotic parameters.

  1. Arsenic in the groundwater of Majuli - The largest river island of the Brahmaputra: Magnitude of occurrence and human exposure

    Science.gov (United States)

    Goswami, Ritusmita; Rahman, Mohammad Mahmudur; Murrill, Matthew; Sarma, Kali Prasad; Thakur, Ritu; Chakraborti, Dipankar

    2014-10-01

    Arsenic (As) concentrations in tube-well water, sediment, and biological samples, including hair, nail and urine were measured to determine the degree of contamination in groundwater and its impact on local inhabitants in the largest populated riverine island Majuli, Assam, India. Arsenic in the groundwater (n = 380) ranged from Ganga-Meghna-Brahmaputra Plain. Significant positive correlations were observed between As in drinking water and As concentrations in hair, nail and urine samples (r = 0.71-0.78). The range of As concentration in bore-hole sediment was 0.29-1.44 mg/kg. The correlation between As and iron in sediment was found to be very poor. Hydrogeological studies are required to understand the source and mobilization process of As in groundwater of Majuli. Early mitigation measures are urgently needed to save the inhabitants of Majuli from arsenic exposure and possible health effects.

  2. Influence of geology on groundwater-sediment interactions in arsenic enriched tectono-morphic aquifers of the Himalayan Brahmaputra river basin

    Science.gov (United States)

    Verma, Swati; Mukherjee, Abhijit; Mahanta, Chandan; Choudhury, Runti; Mitra, Kaushik

    2016-09-01

    The present study interprets the groundwater solute chemistry, hydrogeochemical evolution, arsenic (As) enrichment and aquifer characterization in Brahmaputra River Basin (BRB) involving three geologically and tectono-morphically distinct regions located in northeastern India. These study regions consist of the northwestern (NW) and the northern (N) region, both located along the western and eastern parts of Eastern Himalayas and the southern (S) region (near Indo-Burmese Range and Naga hills) of the Brahmaputra basin which show distinct tectonic settings and sediment provenances in the Himalayan orogenic belt. Stable isotopic composition (δ2H and δ18O) in groundwater suggests that some evaporation may have taken place through recharging of ground water in the study areas. The major-ion composition shows that groundwater composition of the NW and N parts are between Casbnd HCO3 and Casbnd Nasbnd HCO3 while the S-region is dominated by Nasbnd Casbnd HCO3 hydrochemical facies. The major mineralogical composition of aquifer sediments indicates the dominant presence of iron(Fe)-oxide and oxyhydroxides, mica (muscovite and biotite), feldspar, pyroxene, amphibole, abundance of quartz and clay minerals whereas clay is predominantly present in sediments of S-aquifers. These mafic minerals, aluminosilicates and clay minerals might offer available reactive surface for As-adsorption and co-precipitatation with amorphous Fe. These associated adsorbed and co-precipitated As might be released due to reductive dissolution of Fe-oxide and oxyhydroxides in groundwater. These minerals are assumed to be possible sources of As in groundwater. The stability diagrams of groundwater data suggest that solute might have been introduced into groundwater from weathering of K-feldspar, plagioclase, pyroxene of Himalayan rocks, the Siwalik Group and Eastern Syntaxes in NW and N-regions. However, basic cations might be derived from weathering of K-feldspar, plagioclase, pyroxene and olivine

  3. Multivariate statistical evaluation of heavy metals in the surface water sources of Jia Bharali river basin, North Brahmaputra plain, India

    Science.gov (United States)

    Khound, Nayan J.; Bhattacharyya, Krishna G.

    2016-08-01

    The aim of this study was to assess the quality of surfacewater sources in the Jia Bharali river basin and adjoining areas of the Himalayan foothills with respect to heavy elements viz. (As, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) by hydrochemical and multivariate statistical techniques, such as cluster analysis (CA) and principal component analysis (PCA). This study presents the first ever systematic analysis on toxic elements of water samples collected from 35 different surface water sources in both the dry and wet seasons for a duration of 2 hydrological years (2009-2011). Varimax factors extracted by principal component analysis indicates anthropogenic (domestic and agricultural run-off) and geogenic influences on the trace elements. Hierarchical cluster analysis grouped 35 surfacewater sources into three statistically significant clusters based on the similarity of water quality characteristics. This study illustrates the usefulness of multivariate statistical techniques for analysis and interpretation of complex data sets, and in water quality assessment, identification of pollution sources/factors and understanding temporal/spatial variations in water quality for effective surfacewater quality management.

  4. Morphotectonic study of the Brahmaputra basin using geoinformatics

    Science.gov (United States)

    Nath Sarma, Jogendra; Acharjee, Shukla; murgante, Beniamino

    2013-04-01

    The Brahmaputra River basin occupies an area of 580,000 km2 lying in Tibet (China), Bhutan, India and Bangladesh. It is bounded on the north by the Nyen-Chen-Tanghla mountains, on the east by the Salween River basin and Patkari range of hills, on the south by Nepal Himalayas and the Naga Hills and on the west by the Ganga sub-basin. Brahmaputra river originates at an elevation of about 5150 m in south-west Tibet and flows for about 2900 km through Tibet (China), India and Bangladesh to join the Ganga.. The Brahmaputra River basin is investigated to examine the influence of active structures by applying an integrated study on geomorphology, morphotectonics, Digital Elevation Model (DEM) using topographic map, satellite data, SRTM, and seismic data. The indices for morphotectonic analysis, viz. basin elongation ratio (Re) indicated tectonically active, transverse topographic symmetry (T = 0.018-0.664) indicated asymmetric nature, asymmetric factor (AF=33) suggested tilt, valley floor width to valley height ratio (Vf = 0.0013-2.945) indicated active incision and mountain-front sinuosity (Smf = 1.11-1.68) values indicated active tectonics in the area. A great or major earthquake in the modern times, in this region may create havoc with huge loss of life and property due to high population density and rapidly developing infrastructure. Keywords: .Morphotectonic, Brahmaputra river, earthquake

  5. A Tale of Two Deltas: Contrasting Perspectives on the State of Natural and Human-modified Regions of the Ganges-Brahmaputra River Delta (Invited)

    Science.gov (United States)

    Goodbred, S. L.; Wallace Auerbach, L.; Wilson, C.; Gilligan, J. M.; Roy, K.; Ahmed, K.; Steckler, M. S.; Seeber, L.; Akhter, S. H.; Hossain, S.

    2013-12-01

    Effective risk analysis and the management of complex coastal systems require that the scale of interest be well defined. Here we present recent research from the Ganges-Brahmaputra river delta (GBD) that highlights different, if not divergent, perspectives on the current status of this system and its potential response to future environmental change. The contrasts emerge from viewing the GBD at different temporal and spatial scales, raising the question of how scientists, stakeholders, and decision makers might most effectively develop a shared understanding of large, at-risk delta systems. Among the world's deltas, the GBD is often cited as being highly vulnerable to future sea-level rise and environmental change, owing to its vast low-lying landscape and large human population. Taking a broad perspective, however, it is not coincident that the GBD, the world's largest delta system, is fed by immense water and sediment discharge from the Asian monsoon and Himalayan orogen - simply, the size of the GBD reflects the robust processes that have constructed and maintained it. At the regional scale, the deltaplain itself is interconnected by a labyrinth of fluvial and tidal channels that effectively convey sediment to most areas of the landscape, through overbank flooding, distributaries, and tidal transport. Together, the sediment supply, water discharge, and dense channel network bless the GBD with potential basinwide accretion rates >5 mm/yr. More locally, modern sedimentation rates >10 mm/yr are observed in many areas of the tidal delta plain, which are sufficient to maintain land-surface elevations under a variety of sea-level rise scenarios, or at least to mitigate whatever effects do occur. The long-term stratigraphic record of the GBD also reflects a system in dynamic equilibrium, with major landforms persisting through changes in sea level, sediment loading, river avulsion, and delta lobe switching - together providing an encouraging outlook in the face of

  6. Significant cooling effect on the surface due to soot particles over Brahmaputra River Valley region, India: An impact on regional climate.

    Science.gov (United States)

    Tiwari, S; Kumar, R; Tunved, P; Singh, S; Panicker, A S

    2016-08-15

    Black carbon (BC) is an important atmospheric aerosol constituent that affects the climate by absorbing (directly) the sunlight and modifying cloud characteristics (indirectly). Here, we present first time yearlong measurements of BC and carbon monoxide (CO) from an urban location of Guwahati located in the Brahmaputra River valley (BRV) in the northeast region of India from 1st July 2013 to 30th June 2014. Daily BC concentrations varied within the range of 2.86 to 11.56μgm(-3) with an annual average of 7.17±1.89μgm(-3), while, CO varied from 0.19 to 1.20ppm with a mean value of 0.51±0.19ppm during the study period. The concentrations of BC (8.37μgm(-3)) and CO (0.67ppm) were ~39% and ~55% higher during the dry months (October to March) than the wet months (April to September) suggesting that seasonal changes in meteorology and emission sources play an important role in controlling these species. The seasonal ΔBC/ΔCO ratios were highest (lowest) in the pre-monsoon (winter) 18.1±1.4μgm(-3)ppmv(-1) (12.6±2.2μgm(-3)ppmv(-1)) which indicate the combustion of biofuel/biomass as well as direct emissions from fossil fuel during the pre-monsoon season. The annual BC emission was estimated to be 2.72Gg in and around Guwahati which is about 44% lower than the mega city 'Delhi' (4.86Gg). During the study period, the annual mean radiative forcing (RF) at the top of the atmosphere (TOA) for clear skies of BC was +9.5Wm(-2), however, the RF value at the surface (SFC) was -21.1Wm(-2) which indicates the net warming and cooling effects, respectively. The highest RF at SFC was in the month of April (-30Wm(-2)) which is coincident with the highest BC mass level. The BC atmospheric radiative forcing (ARF) was +30.16 (annual mean) Wm(-2) varying from +23.1 to +43.8Wm(-2). The annual mean atmospheric heating rate (AHR) due to the BC aerosols was 0.86Kday(-1) indicates the enhancement in radiation effect over the study region. The Weather Research and Forecasting model

  7. Significant cooling effect on the surface due to soot particles over Brahmaputra River Valley region, India: An impact on regional climate.

    Science.gov (United States)

    Tiwari, S; Kumar, R; Tunved, P; Singh, S; Panicker, A S

    2016-08-15

    Black carbon (BC) is an important atmospheric aerosol constituent that affects the climate by absorbing (directly) the sunlight and modifying cloud characteristics (indirectly). Here, we present first time yearlong measurements of BC and carbon monoxide (CO) from an urban location of Guwahati located in the Brahmaputra River valley (BRV) in the northeast region of India from 1st July 2013 to 30th June 2014. Daily BC concentrations varied within the range of 2.86 to 11.56μgm(-3) with an annual average of 7.17±1.89μgm(-3), while, CO varied from 0.19 to 1.20ppm with a mean value of 0.51±0.19ppm during the study period. The concentrations of BC (8.37μgm(-3)) and CO (0.67ppm) were ~39% and ~55% higher during the dry months (October to March) than the wet months (April to September) suggesting that seasonal changes in meteorology and emission sources play an important role in controlling these species. The seasonal ΔBC/ΔCO ratios were highest (lowest) in the pre-monsoon (winter) 18.1±1.4μgm(-3)ppmv(-1) (12.6±2.2μgm(-3)ppmv(-1)) which indicate the combustion of biofuel/biomass as well as direct emissions from fossil fuel during the pre-monsoon season. The annual BC emission was estimated to be 2.72Gg in and around Guwahati which is about 44% lower than the mega city 'Delhi' (4.86Gg). During the study period, the annual mean radiative forcing (RF) at the top of the atmosphere (TOA) for clear skies of BC was +9.5Wm(-2), however, the RF value at the surface (SFC) was -21.1Wm(-2) which indicates the net warming and cooling effects, respectively. The highest RF at SFC was in the month of April (-30Wm(-2)) which is coincident with the highest BC mass level. The BC atmospheric radiative forcing (ARF) was +30.16 (annual mean) Wm(-2) varying from +23.1 to +43.8Wm(-2). The annual mean atmospheric heating rate (AHR) due to the BC aerosols was 0.86Kday(-1) indicates the enhancement in radiation effect over the study region. The Weather Research and Forecasting model

  8. Uranium removal during low discharge in the Ganges-Brahmaputra mixing zone

    Energy Technology Data Exchange (ETDEWEB)

    Carroll, J.; Moore, W.S. (Univ. of South Carolina, Columbia, SC (United States))

    1993-11-01

    The Ganges-Brahmaputra river system supplies more dissolved uranium to the ocean than any other system in the world (Sarin et al., 1990; Sackett et al., 1973). However, there have been no investigations to determine whether riverine supplies of uranium are altered by geochemical reactions in the river-ocean mixing zone. In this study, uranium and salinity data were collected in the Ganges-Brahmaputra mixing zone during a period of low river discharge. The uranium distribution with salinity shows that in waters <12 ppt salinity, uranium activities are significantly lower than predicted from conservative mixing of river and seawater. This suggests that uranium is being removed within the mixing zone. The behavior of uranium in the Ganges-Brahmaputra is in sharp contrast to its behavior in the Amazon mixing zone where McKee et al. (1978) found uranium activities significantly higher than predicted from conservative mixing. The contrasting behaviors for uranium in these systems are due to the different locations where mixing between river and seawater occurs. For the Amazon, mixing takes place on the continental shelf whereas for the Ganges-Brahmaputra, mixing occurs within shoreline sedimentary environments. The physiochemical processes controlling uranium removal to sediment deposits in the Amazon are partly known. The authors discuss mechanisms which may be removing uranium to suspended and mangrove sediments in the Ganges-Brahmaputra.

  9. Ref: Changing river courses in the western part of the Ganga-Brahmaputra delta by Kalyan Rudra (2014), Geomorphology, 227, 87-100

    Science.gov (United States)

    Rudra, Kalyan

    2015-12-01

    Research on river dynamics of the GB delta is in the early stages, and it is a topic of multidisciplinary interest. A narrow sectoral approach of research may lead to much confusion. The 'discussion' has a declared vision of offering corrected information against inconsistencies, improper understanding, and misrepresentation of facts in my paper. But in reality, the critics' arguments are based on the wrong premise, and those may create much confusion. This reply is designed sequentially to address issues raised in the 'discussion'.

  10. Valley of the Brahmaputra, India, and Mouths of the Ganges, Bangladesh

    Science.gov (United States)

    2002-01-01

    In this true-color MODIS image from October 23, 2001, the semi-arid Tibetan Plateau (upper left) meets up with the Himalayas to the south. From the heights of the Himalayas, snow-covered on their northern flanks, and lush with vegetation to the south, numerous rivers, brown with churned up sediment, flow into the valley of the Brahmaputra River in Assam, India. The Brahmaputra turns southward at the border of Bangladesh and is soon joined by the Ganges River, flowing in from image left. The mighty river splits into numerous channels as it runs out toward the Bay of Bengal, giving the region the name 'Mouths of the Ganges.' Vast amounts of sediment are being emptied into the Bay by the river, and greenish blue swirls could be a mixture of sediment and phytoplankton.

  11. Mangrove wetland ecosystems in Ganges-Brahmaputra delta in Bangladesh

    Institute of Scientific and Technical Information of China (English)

    Shafi Noor ISLAM; Albrecht GNAUCK

    2008-01-01

    The Sundarbans is one of the productive man-grove wetland ecosystems in the Ganges-Brahmaputra delta in Bangladesh. The delta is undergoing rapid eco-logical changes due to human activity. In the present study, surface water salinity data from 13 rivers of the Sundarbans were collected in order to investigate the sal-ine water intrusion in the mangrove wetlands. Results demonstrate that saline water has penetrated the upstream area as river water salinity has increased signifi-cantly in 1976 compared to the year 1968. The soil and river water salinity data also shows that it has crossed the water salinity threshold line in most parts of the Sundarbans wetlands. These observations are due to the construction of Farakka Barrage in 1975, which reduced the water discharge of the Ganges River from 3700 m3/s in 1962 to 364 m3/s in 2006. The shortage of freshwater dis-charge to the deltaic area is trailing active ecosystems function, especially in the dry season in the south western region in Bangladesh. The objective of this study is to understand and analyze the present degraded mangrove wetland ecosystems and their negative impacts. The find-ings of this study would contribute to the formulation of the mangrove wetland ecosystems management plan inthe Ganges delta of Bangladesh.

  12. Future Visions of the Brahmaputra - Establishing Hydrologic Baseline and Water Resources Context

    Science.gov (United States)

    Ray, P. A.; Yang, Y. E.; Wi, S.; Brown, C. M.

    2013-12-01

    The Brahmaputra River Basin (China-India-Bhutan-Bangladesh) is on the verge of a transition from a largely free flowing and highly variable river to a basin of rapid investment and infrastructure development. This work demonstrates a knowledge platform for the basin that compiles available data, and develops hydrologic and water resources system models of the basin. A Variable Infiltration Capacity (VIC) model of the Brahmaputra basin supplies hydrologic information of major tributaries to a water resources system model, which routes runoff generated via the VIC model through water infrastructure, and accounts for water withdrawals for agriculture, hydropower generation, municipal demand, return flows and others human activities. The system model also simulates agricultural production and the economic value of water in its various uses, including municipal, agricultural, and hydropower. Furthermore, the modeling framework incorporates plausible climate change scenarios based on the latest projections of changes to contributing glaciers (upstream), as well as changes to monsoon behavior (downstream). Water resources projects proposed in the Brahmaputra basin are evaluated based on their distribution of benefits and costs in the absence of well-defined water entitlements, and relative to a complex regional water-energy-food nexus. Results of this project will provide a basis for water sharing negotiation among the four countries and inform trans-national water-energy policy making.

  13. The role of the Ganges-Brahmaputra mixing zone in supplying barium and [sup 226]Ra to the Bay of Bengal

    Energy Technology Data Exchange (ETDEWEB)

    Carroll, J. (Univ. of South Carolina, Columbia (United States) Univ. of Alaska, Fairbanks (United States)); Falkner, K.K. (Massachusetts Inst. of Technology, Cambridge (United States) CNES, Toulouse (France)); Brown, E.T. (Massachusetts Inst. of Technology, Cambridge (United States)); Moore, W.S. (Univ. of South Carolina, Columbia (United States))

    1993-07-01

    The Ganges-Brahmaputra river system is ranked fourth among world rivers as a source of freshwater to the oceans and is believed to supply more sediment to the ocean than any other; 1.5 [times] 10[sup 12] kg/yr (Milliman and Meade, 1983). Barium and [sup 226]Ra are typically enriched in waters where sediment-laden rivers enter the ocean. As such, the Ganges-Brahmaputra is likely to produce globally significant barium and [sup 226]Ra fluxes to the ocean. Water samples for barium and [sup 226]Ra were collected within four major channels of the Ganges-Brahmaputra mixing zone during a period of low sediment and freshwater discharge. The data suggest that in addition to suspended sediments supplied directly from rivers, river sediments deposited during high discharge in mangroves and on islands are desorbing barium and [sup 226]Ra to seawater. The release of barium and [sup 226]Ra from these sediment deposits is out-of-phase with the direct supply of sediments from the rivers. Estimates of the annual fluxes of barium and [sup 226]Ra from the Ganges-Brahmaputra mixing zone were also derived. The fluxes of barium and [sup 226]Ra are 5.3 [times] 10[sup 8] mol barium/yr and 9.5 [times] 10[sub 14] dpm radium/yr. The first silicate and phosphate mixing profiles for this system are reported. 29 refs., 6 figs., 3 tabs.

  14. Ganges-Brahmaputra Delta: Balance of Subsidence, Sea level and Sedimentation in a Tectonically-Active Delta (Invited)

    Science.gov (United States)

    Steckler, M. S.; Goodbred, S. L.; Akhter, S. H.; Seeber, L.; Reitz, M. D.; Paola, C.; Nooner, S. L.; DeWolf, S.; Ferguson, E. K.; Gale, J.; Hossain, S.; Howe, M.; Kim, W.; McHugh, C. M.; Mondal, D. R.; Petter, A. L.; Pickering, J.; Sincavage, R.; Williams, L. A.; Wilson, C.; Zumberge, M. A.

    2013-12-01

    Bangladesh is vulnerable to a host of short and long-term natural hazards - widespread seasonal flooding, river erosion and channel avulsions, permanent land loss from sea level rise, natural groundwater arsenic, recurrent cyclones, landslides and huge earthquakes. These hazards derive from active fluvial processes related to the growth of the delta and the tectonics at the India-Burma-Tibet plate junctions. The Ganges and Brahmaputra rivers drain 3/4 of the Himalayas and carry ~1 GT/y of sediment, 6-8% of the total world flux. In Bangladesh, these two great rivers combine with the Meghna River to form the Ganges-Brahmaputra-Meghna Delta (GBMD). The seasonality of the rivers' water and sediment discharge is a major influence causing widespread flooding during the summer monsoon. The mass of the water is so great that it causes 5-6 cm of seasonal elastic deformation of the delta discerned by our GPS data. Over the longer-term, the rivers are also dynamic. Two centuries ago, the Brahmaputra River avulsed westward up to 100 km and has since captured other rivers. The primary mouth of the Ganges has shifted 100s of km eastward from the Hooghly River over the last 400y, finally joining the Brahmaputra in the 19th century. These avulsions are influenced by the tectonics of the delta. On the east side of Bangladesh, the >16 km thick GBMD is being overridden by the Burma Arc where the attempted subduction of such a thick sediment pile has created a huge accretionary prism. The foldbelt is up to 250-km wide and its front is buried beneath the delta. The main Himalayan thrust front is 130 wells are illuminating the Holocene shifts of the Brahmaputra River and subsidence patterns. Very high resolution MCS seismics on the rivers shows deformation by subsidence and compaction. Resistivity is further mapping surfaces warped by the anticlinal folds. GPS geodesy is quantifying the rates of overthrusting and differential subsidence across the delta. Optical fiber strain meters

  15. Impact of Ganges–Brahmaputra interannual discharge variations on Bay of Bengal salinity and temperature during 1992–1999 period

    Indian Academy of Sciences (India)

    Fabien Durand; Fabrice Papa; Atiqur Rahman; Sujit Kumar Bala

    2011-10-01

    This study investigates the impact of monthly Ganges–Brahmaputra river discharge variations on Bay of Bengal salinity and temperature during the period 1992–1999. The Ganges–Brahmaputra river discharge is characterized by a well-defined seasonal cycle with strong interannual variations. The highest/lowest yearly peak discharge occurs in summer 1998/summer 1992, with 1998 value amounting to twice that of 1992. This river discharge is then used to force an ocean general circulation model. Our main result is that the impact of these rivers on the variability of Bay of Bengal sea surface salinity is strong in the northern part, with excess run-off forcing fresh anomalies, and vice versa. Most of the years, the influence of the interannual variability of river discharge on the Bay salinity does not extend south of ∼10° N. This stands in contrast with the available observations and is probably linked to the relatively coarse resolution of our model. However, the extreme discharge anomaly of 1998 is exported through the southern boundary of the Bay and penetrates the south-eastern Arabian Sea a few months after the discharge peak. In response to the discharge anomalies, the model simulates significant mixed-layer temperature anomalies in the northern Bay of Bengal. This has the potential to influence the climate of the area. From our conclusions, it appears necessary to use a numerical model with higher resolution (both on the horizontal and vertical) to quantitatively investigate the upper Bay of Bengal salinity structure.

  16. Between Sunda subduction and Himalayan collision: fertility, people and earthquakes on the Ganges-Brahmaputra Delta

    Science.gov (United States)

    Seeber, L.; Steckler, M. S.; Akhter, S. H.; Goodbred, S. L., Jr.; Gale, J.; McHugh, C. M.; Ferguson, E. K.; Mondal, D. R.; Paola, C.; Reitz, M. D.; Wilson, C.

    2014-12-01

    A foreland (Ganges) and a suture (Brahmaputra) river, which both drain the Himalaya, have coalesced to form Ganges-Brahmaputra Delta (GBD), the world's largest. The GBD progrades along the continental margin, coupled with an advancing subduction to collision transition, deforming the delta as it grows. A better understanding of this time-transgressive system is urgent now that humans are increasing their forcing of the system and exposure to environmental hazards. Among these, earthquake risk is rapidly growing as people move from rural settings into expanding cities, creating unprecedented exposure. The megathrust 1950 M8.7 earthquake in Assam occurred during the monsoon and released 10x the annual sediment load, causing progradation at the coast and a pulse of river widening that propagated downstream. The 1762 M8.8(?) along the Arakan coast extended into the shelf of the delta where coastal tsunami deposits have been identified recently. These events bracket a segment with no credible historic megathrust earthquakes, but could affect far more people. Geodetic and geologic data along this 300 km boundary facing the GBD show oblique contraction. The subaerial accretionary prism (Burma Ranges) is up to 250 km wide with a blind thrust front that reaches ½ way across the delta. The GPS convergence rate of 14 mm/y is consistent with large displacements and long interseismic times, which can account for lack of historic ruptures, but also the potential for catastrophic events. Active folds and shallow thrust earthquakes point to an additional threat from upper-plate seismicity. Much of the current seismicity is in the lower-plate and reaches as far west as Dhaka; it may pose an immediate threat. The folds, and the uplift and subsidence patterns also influence the courses of the rivers. North of the delta, the Shillong plateau is a huge basement cored anticline bounded by the north-dipping Dauki thrust fault. 7 mm/y of N-S shortening and 5 km of structural relief here

  17. Amblyceps waikhomi, a New Species of Catfish (Siluriformes: Amblycipitidae) from the Brahmaputra Drainage of Arunachal Pradesh, India.

    Science.gov (United States)

    Darshan, Achom; Kachari, Akash; Dutta, Rashmi; Ganguly, Arijit; Das, Debangshu Narayan

    2016-01-01

    Amblyceps waikhomi sp. nov. is described from the Nongkon stream which drains into the Noa Dehing River, a tributary of the Brahmaputra River, in Arunachal Pradesh, India. The new species can be distinguished from congeners (except A. torrentis) in having a deeper body depth at anus. It further differs from congeners (except A. mangois and A. serratum) in having fewer vertebrae, from A. mangois in lacking (vs. having) strongly-developed projections on the proximal lepidotrichia of the median caudal-fin rays, and in having a longer, wider, and deeper head; and from A. serratum in having a posteriorly smooth (vs. with 4-5 serrations) pectoral spine, and unequal jaw length (lower jaw longer and weakly-projecting anteriorly vs. equal upper and lower jaws). It additionally differs from A. murraystuarti, A. torrentis, A. apangi, A. laticeps, and A. cerinum in having a deeply forked (vs. emarginate or truncate) caudal fin. This species is the seventh amblycipitid species known to occur in the Ganga-Brahmaputra River system.

  18. Amblyceps waikhomi, a New Species of Catfish (Siluriformes: Amblycipitidae from the Brahmaputra Drainage of Arunachal Pradesh, India.

    Directory of Open Access Journals (Sweden)

    Achom Darshan

    Full Text Available Amblyceps waikhomi sp. nov. is described from the Nongkon stream which drains into the Noa Dehing River, a tributary of the Brahmaputra River, in Arunachal Pradesh, India. The new species can be distinguished from congeners (except A. torrentis in having a deeper body depth at anus. It further differs from congeners (except A. mangois and A. serratum in having fewer vertebrae, from A. mangois in lacking (vs. having strongly-developed projections on the proximal lepidotrichia of the median caudal-fin rays, and in having a longer, wider, and deeper head; and from A. serratum in having a posteriorly smooth (vs. with 4-5 serrations pectoral spine, and unequal jaw length (lower jaw longer and weakly-projecting anteriorly vs. equal upper and lower jaws. It additionally differs from A. murraystuarti, A. torrentis, A. apangi, A. laticeps, and A. cerinum in having a deeply forked (vs. emarginate or truncate caudal fin. This species is the seventh amblycipitid species known to occur in the Ganga-Brahmaputra River system.

  19. Amblyceps waikhomi, a New Species of Catfish (Siluriformes: Amblycipitidae) from the Brahmaputra Drainage of Arunachal Pradesh, India.

    Science.gov (United States)

    Darshan, Achom; Kachari, Akash; Dutta, Rashmi; Ganguly, Arijit; Das, Debangshu Narayan

    2016-01-01

    Amblyceps waikhomi sp. nov. is described from the Nongkon stream which drains into the Noa Dehing River, a tributary of the Brahmaputra River, in Arunachal Pradesh, India. The new species can be distinguished from congeners (except A. torrentis) in having a deeper body depth at anus. It further differs from congeners (except A. mangois and A. serratum) in having fewer vertebrae, from A. mangois in lacking (vs. having) strongly-developed projections on the proximal lepidotrichia of the median caudal-fin rays, and in having a longer, wider, and deeper head; and from A. serratum in having a posteriorly smooth (vs. with 4-5 serrations) pectoral spine, and unequal jaw length (lower jaw longer and weakly-projecting anteriorly vs. equal upper and lower jaws). It additionally differs from A. murraystuarti, A. torrentis, A. apangi, A. laticeps, and A. cerinum in having a deeply forked (vs. emarginate or truncate) caudal fin. This species is the seventh amblycipitid species known to occur in the Ganga-Brahmaputra River system. PMID:26840400

  20. Morphotectonic evolution of the Majuli Island in the Brahmaputra valley of Assam, India inferred from geomorphic and geophysical analysis

    Science.gov (United States)

    Lahiri, Siddhartha K.; Sinha, Rajiv

    2014-12-01

    The Majuli Island, located in the upper reach of the Brahmaputra valley in Assam (India), has reduced in its areal extent from 787.9 km2 to 508.2 km2 during the period 1915-2005 (35.5% reduction). This amounts to severe average erosion of 3.1 km2/yr. All efforts so far to save the island have failed to achieve the desired redress. The engineering approach of ‘Save Majuli' action plans has focused on quarantining the island from the influence of the Brahmaputra River rather than designing long-term process-based solutions anchored on proper understanding of evolution of the relic island. The existing geomorphic model for the evolution of the Majuli Island related its genesis to the great earthquake (M 8.7) in 1750 during which a much smaller palaeo-Brahmaputra developed an anabranch and captured the Burhi Dihing River. The intermediate land-locked area thereby became the Majuli Island that is constituted primarily of the older floodplain deposits. We demonstrate that the evolution of the Majuli Island has been influenced by fluvial morpho-dynamics, as well as basement configuration and tectonic controls. Thus, the landform called the Majuli Island cannot be explained as a simple fluvial geomorphic feature. Rather, it represents an outcome of tectono-geomorphic process having strong subsurface control. We have investigated the influence of geomorphic parameters including channel belt area (CHB), channel belt width (W), braid bar area (BB), channel area (CH), thalweg changes and bankline migration on the trend of erosion of the Majuli Island. Integration of geophysical evidence from seismic data and the surface morphological changes suggest that the Majuli Island and other similar landforms represent structural ‘highs'. Morpho-tectonic evolution of these islands has involved three stages- pre-bypass uplift, Majuli formation and abandonment. The Majuli Island in the Brahmaputra valley is presently passing through the abandonment stage and is gradually being

  1. Holocene construction and evolution of the Ganges-Brahmaputra-Meghna delta: the influence of climate, eustasy, and tectonics on stratigraphic architecture and fluvial dynamics

    Science.gov (United States)

    Sincavage, R.; Goodbred, S. L., Jr.; Pickering, J.; Wilson, C.; Patrick, M. G.; Akhter, S. H.; Seeber, L.; Paola, C.; Jean-Louis, G.; Grall, C.

    2015-12-01

    The Ganges-Brahmaputra-Meghna delta (GBMD), an archetypal tidally-influenced deltaic margin, has been the subject of several multi-national, multi-institutional, and interdisciplinary field studies over the past several years, resulting in an unprecedented density of data coverage for stratigraphy, hydrodynamics, and tectonics on a scale previously only found on well-studied delta systems of other types (e.g., Nile, Mississippi, Rhine-Meuse). Using a suite of geochemical, geophysical, and lithologic data extracted from a network of over 400 shallow (sediments suggests the position of the Brahmaputra River was once west of its modern location, following a course along the eastern edge of the Tista Fan and west of the modern confluence with the Ganges. Construction of the modern delta, consisting of a thick (up to 80 m) succession of fluvial and deltaic sediments, was initiated by an intensified summer monsoon, coincident with accommodation generated by rapid sea-level rise following the Younger-Dryas. Sediment delivery has been focused along three pathways associated with antecedent topography inherited from Pleistocene lowstands. Stacked channel sands are the predominant facies within the upper delta, grading to isolated sand lenses in the distal reaches of Sylhet Basin, indicative of a shift from a highly mobile braidbelt to a less mobile distributary system as bedload is extracted to deposition. Episodic avulsions of the Brahmaputra River into Sylhet Basin during the mid-Holocene have been documented using a robust radiocarbon geochronology. The volume of sediment preserved from these events is insufficient to account for the entire sediment budget based on estimates of modern discharge, likely a consequence of both a weakened mid-Holocene monsoon and bypass out of the basin. Rapid (up to 7 mm/yr) subsidence in Sylhet Basin has not acted as an attractor for channel steering during much of the Holocene. Instead, the Brahmaputra has followed the steepest descent

  2. Sensitivity of Different Satellites Gridded data over Brahmaputra Basin by using Soil and Water Assessment Tool (SWAT)

    Science.gov (United States)

    Paul, S.; Islam, A. S.; Hasan, M. A.

    2015-12-01

    More than half a billion people of India, China, Nepal, Bangladesh and Bhutan are directly or indirectly dependent on the water resources of the Brahmaputrariver. With climatic and anthropogenic change of this basin region is becoming a cause of concern for future water management and sharing with transboundary riparian nations. To address such issues, robust watershed runoff modeling of the basin is essential. Soil and Water Assessment Tool (SWAT) is a widely used semi-distributed watershed model that is capable of analyzing surface runoff, stream flow, water yield,sediment and nutrienttransport in a large river basin such as Brahmaputra, but the performance of runoff the model depends on the accuracy of input precipitation datasets. But for a transboundary basin like Brahmaputra, precipitation gauge data from upstream areas is either not available or not accessible to the scientific communities.Satellite rainfall products are very effective where radar datasets are absent and conventional rain gauges are sparse. However, the sensitivity of the SWAT model to different satellite data products as well as hydrologic parameters for the Brahmaputra Basin are largely unknown. Thus in this study, a comparative analysis with different satellite data product has been made to assess the runoff using SWAT model. Here, data from three sources: TRMM, APHRDOTIE and GPCP were used as input precipitation satellite data set and ERA-Interim was used as input temperature dataset from 1998 to 2009. The main methods used in modeling the hydrologic processes in SWAT were curve number method for runoff estimating, Penman-Monteith method for PET and Muskingum method for channel routing. Our preliminary results have revealed thatthe TRMM data product is more accurate than APHRODITE and GPCP for runoff analysis. The coefficient of determination (R2) and Nash-Sutcliffe efficiencies for both calibration and validation period from TRMM data are 0.83 and 0.72, respectively.

  3. Stratigraphic Evolution of the Ganges-Brahmaputra Lower Delta Plain and its Relation to Groundwater Arsenic Distributions

    Science.gov (United States)

    Patrick, M. G.; Goodbred, S. L., Jr.; Gilligan, J. M.; Tasich, C. M.; Hossain, S.; Ahmed, K. M.

    2015-12-01

    Bangladesh is plagued by high concentrations of naturally occurring arsenic (As) in the shallow groundwater of the Ganges-Brahmaputra-Meghna delta (GBMD), leading to widespread poisoning of people in the region. Most of the 156 million people in Bangladesh obtain their drinking water through hand-pumped tube wells that often draw arsenic-contaminated water from shallow, Holocene-age aquifers of the delta. The distribution of arsenic within these aquifers is heterogeneous and linked with the complex stratigraphy of the GBMD through its controls on hydrogeology and aquifer biogeochemistry. This research investigates differences in the fluvio-deltaic deposits formed by the Ganges and Brahmaputra rivers, as well as differences in the tectonic setting across the lower delta plain. Furthermore, we investigate how these overarching controls influence stratigraphic architecture and the resulting aquifer systems, and ultimately the distribution of As within the shallow aquifers of the lower delta plain. To accomplish this, a transect of 55 sediment cores spanning the entire lower delta plain of Bangladesh was drilled to a depth of 90 m. In addition to knowledge of the stratigraphic architecture gained from borehole lithologs, samples from these cores were analyzed for provenance and grain size to determine source of the sediments and the depositional history of the rivers. Relating delta stratigraphy to As distribution was accomplished by measuring groundwater As in 10-20 tubewells within a 1 km radius of each borehole. This data was combined with groundwater data from the Bangladesh Arsenic Mitigation Water Supply Project within 25 km of the transect. Statistical analysis of the groundwater data was then conducted using hierarchical regressions as well as a nearest neighbor algorithm. This study provides a better understanding of Holocene delta evolution and river behavior, as well as a more complete understanding of the geologic controls on As and the characteristics of

  4. Lithium isotope fractionation in the Ganges-Brahmaputra floodplain and implications for groundwater impact on seawater isotopic composition

    Science.gov (United States)

    Bagard, Marie-Laure; West, A. Joshua; Newman, Karla; Basu, Asish R.

    2015-12-01

    Lithium isotopes are a promising proxy for reconstructing past weathering processes, but unraveling the seawater record requires a comprehensive understanding of the magnitude and isotopic composition of Li fluxes to the oceans, and of how these change over time. Little information is available on the role of floodplain sediments and groundwater systems in setting the Li isotope signature of the dissolved flux delivered from the continents to the oceans. Here we investigate the Li dissolved fluxes of river waters and groundwaters in the Ganges-Brahmaputra floodplain. The data suggest that a maximum of 3.1 ×108 and 1.5 ×108 moles Li/yr are carried to the Bay of Bengal by Ganges-Brahmaputra rivers and groundwaters, respectively. The riverine flux has a significantly heavier Li isotope composition (average δ7Li: 26‰) than the groundwater flux (average δ7Li: 16‰) and increases downstream across the floodplain. δ7Li in both river waters and shallow groundwater can be explained by Li scavenging by Quaternary floodplain sediments following a Rayleigh fractionation process, with preferential removal of 6Li. On the other hand, deep groundwaters (>40 m) contributing to submarine groundwater discharge to the Bay of Bengal are enriched in 6Li at depth, likely due to the dissolution of floodplain sediments releasing Li with a light isotope composition. Similarly low δ7Li has been reported in other large sedimentary aquifers. The deep groundwater values are close to the average isotope composition of the global Li inputs to the ocean (∼15‰), so groundwater submarine discharge has only a minor influence on the assessment of the modern Li isotope budget of the ocean. Our analysis further suggests that groundwater discharge of Li has probably played at most a small and secondary role in past changes in the isotope composition of the total continental flux of Li to the ocean.

  5. Hydrological cycle over South and Southeast Asian river basins as simulated by PCMDI/CMIP3 experiments

    OpenAIRE

    Hasson, S.; Lucarini, V.; Pascale, S.

    2013-01-01

    We investigate how CMIP3 climate models describe the hydrological cycle over four major South and Southeast Asian river basins (Indus, Ganges, Brahmaputra and Mekong) for the XX, XXI, and XXII centuries. For the XX century, models' simulated water balance and total runoff quantities are neither consistent with the observed mean river discharges nor among the models. Most of the models underestimate the water balance for the Ganges, Brahmaputra and Mekong basin and overestimate it for the Indu...

  6. Rainfall runoff modelling of the Upper Ganga and Brahmaputra basins using PERSiST.

    Science.gov (United States)

    Futter, M N; Whitehead, P G; Sarkar, S; Rodda, H; Crossman, J

    2015-06-01

    There are ongoing discussions about the appropriate level of complexity and sources of uncertainty in rainfall runoff models. Simulations for operational hydrology, flood forecasting or nutrient transport all warrant different levels of complexity in the modelling approach. More complex model structures are appropriate for simulations of land-cover dependent nutrient transport while more parsimonious model structures may be adequate for runoff simulation. The appropriate level of complexity is also dependent on data availability. Here, we use PERSiST; a simple, semi-distributed dynamic rainfall-runoff modelling toolkit to simulate flows in the Upper Ganges and Brahmaputra rivers. We present two sets of simulations driven by single time series of daily precipitation and temperature using simple (A) and complex (B) model structures based on uniform and hydrochemically relevant land covers respectively. Models were compared based on ensembles of Bayesian Information Criterion (BIC) statistics. Equifinality was observed for parameters but not for model structures. Model performance was better for the more complex (B) structural representations than for parsimonious model structures. The results show that structural uncertainty is more important than parameter uncertainty. The ensembles of BIC statistics suggested that neither structural representation was preferable in a statistical sense. Simulations presented here confirm that relatively simple models with limited data requirements can be used to credibly simulate flows and water balance components needed for nutrient flux modelling in large, data-poor basins.

  7. Systematic Evaluation of Satellite-Based Rainfall Products over the Brahmaputra Basin for Hydrological Applications

    Directory of Open Access Journals (Sweden)

    Sagar Ratna Bajracharya

    2015-01-01

    Full Text Available Estimation of the flow generated in the Brahmaputra river basin is important for establishing an effective flood prediction and warning services as well as for water resources assessment and management. But this is a data scarce region with few and unevenly distributed hydrometeorological stations. Five high-resolution satellite rainfall products (CPC RFE2.0, RFE2.0-Modified, CMORPH, GSMaP, and TRMM 3B42 were evaluated at different spatial and temporal resolutions (daily, dekadal, monthly, and seasonal with observed rain gauge data from 2004 to 2006 to determine their ability to fill the data gap and suitability for use in hydrological and water resources management applications. Grid-to-grid (G-G and catchment-to-catchment (C-C comparisons were performed using the verification methods developed by the International Precipitation Working Group (IPWG. Comparing different products, RFE2.0-Modified, TRMM 3B42, and CMORPH performed best; they all detected heavy, moderate, and low rainfall but still significantly underestimated magnitude of rainfall, particularly in orographically influenced areas. Overall, RFE2.0-Modified performed best showing a high correlation coefficient with observed data and low mean absolute error, root mean square error, and multiple bias and is reasonably good at detecting the occurrence of rainfall. TRMM 3B42 showed the second best performance. The study demonstrates that there is a potential use of satellite rainfall in a data scarce region.

  8. Constraining the timing of Shillong Plateau uplift from a study of the palaeo-Brahmaputra deposits, Siwalik Group, Samdrup Jongkhar, Eastern Bhutan

    Science.gov (United States)

    Govin, G.; Najman, Y.; Grujic, D.; Van Der Beek, P.; Davenport, J.; Huyghe, P.

    2015-12-01

    The ~400 km long and two km high Shillong Plateau is the only major raised topography in the Himalayan foreland. Debates over the timing of uplift and implication for erosion-climate-tectonic couplings, strain partitioning within the Himalaya and the palaeodrainage history of the palaeo-Brahmaputra are important. Grujic et al, (2006) proposed that the uplift of the plateau has affected the exhumation of Himalayan rocks to the north in Bhutan, due to the creation of a regional climatic change in the plateau's rain shadow. By contrast, Coutand et al. (2014) suggest that the local decrease in erosion rates in the eastern Bhutan Himalaya is best explained by the decrease in overthrusting rates at 5-6 Ma, which might be potentially related to late Miocene to Pliocene changes in the India-southern Eurasia convergence partitioning, with shortening taken up by faults bounding the Shillong Plateau, i.e. by its uplift. The exhumation of the Shillong Plateau has been proposed to initiate by 8-15 Ma (Biswas et al, 2007; Clark & Bilham, 2008) whilst surface uplift, decoupled from exhumation, of Miocene (Chirouze et al 2013), Pliocene (Johnson and Nur Alam 1991; Biswas et al., 2007) and Early Quaternary (Najman et al, in review) have been proposed. Our study uses the foreland basin Siwalik sedimentary record preserved to the north of the Shillong Plateau in Bhutan, to constrain the plateau's uplift history. Provenance is characterized by U-Pb dating on detrital zircons, which allows specifically documenting an Indus-Yarlung suture-zone and therefore paleo-Brahmaputra signature. We document the timing that the palaeo-Brahmaputra was shunted north and west by the rising plateau, using this U/Pb provenance technique to detect first appearance of the river and to a minor degree the Namche Barwa syntaxe signature. The results allow to better constrain the period of uplifting of the Shillong Plateau and thus better inform the implications through a study of the palaeodrainage of the

  9. Heavy metal contaminations in the groundwater of Brahmaputra flood plain: an assessment of water quality in Barpeta District, Assam (India).

    Science.gov (United States)

    Haloi, Nabanita; Sarma, H P

    2012-10-01

    A study was conducted to evaluate the heavy metal contamination status of groundwater in Brahmaputra flood plain Barpeta District, Assam, India. The Brahmaputra River flows from the southern part of the district and its many tributaries flow from north to south. Cd, Fe, Mn, Pb, and Zn are estimated by using atomic absorption spectrometer, Perkin Elmer AA 200. The quantity of heavy metals in drinking water should be checked time to time; as heavy metal accumulation will cause numerous problems to living being. Forty groundwater samples were collected mainly from tube wells from the flood plain area. As there is very little information available about the heavy metal contamination status in the heavily populated study area, the present work will help to be acquainted with the suitability of groundwater for drinking applications as well as it will enhance the database. The concentration of iron exceeds the WHO recommended levels of 0.3 mg/L in about 80% of the samples, manganese values exceed 0.4 mg/L in about 22.5% of the samples, and lead values also exceed limit in 22.5% of the samples. Cd is reported in only four sampling locations and three of them exceed the WHO permissible limit (0.003 mg/L). Zinc concentrations were found to be within the prescribed WHO limits. Therefore, pressing awareness is needed for the betterment of water quality; for the sake of safe drinking water. Statistical analysis of the data was carried out using Special Package for Social Sciences (SPSS 16).

  10. Impact of climate change on flood characteristics in Brahmaputra basin using a macro-scale distributed hydrological model

    Indian Academy of Sciences (India)

    Shyamal Ghosh; Subashisa Dutta

    2012-06-01

    Being the highest specific discharge river system in the world, the Brahmaputra river experiences a number of long-duration flood waves during the monsoon season annually. In order to assess the flood characteristics at the basin and tributary scales, a physically based macro-scale distributed hydrological model (DHM) has been calibrated and validated for 9 wet years. The model performance has been evaluated in terms of prediction of the flood characteristics such as peak discharge, flood duration, arrival time of flood wave, timing of the peak flow and number of flood waves per season. Future changes in the flood wave characteristics of the basin have been evaluated using the validated model with bias-corrected future-projected meteorological scenario from a regional climate model (RCM). Likelihood analysis of the simulated flow time series reveals that significant increase in both peak discharge and flood duration is expected for both the pre-monsoonal and monsoonal seasons in the basin, but the number of flood waves per season would be reduced. Under the projected climate change scenario, it is expected that there will be more catastrophic floods in the basin.

  11. Spatio-temporal variability of rainfall regime in the Brahmaputra valley of North East India

    Science.gov (United States)

    Deka, R. L.; Mahanta, C.; Nath, K. K.; Dutta, M. K.

    2016-05-01

    Monthly rainfall data, spanning over 110 years (1901-2010), were utilized for trend analysis at different spatial and temporal scales over the Brahmaputra valley, India. The Mann-Kendall statistic and Sen's slope model were used to identify the trends and estimate the magnitude of change, respectively. Statistical significance of the decadal shifts in rainfall from the overall mean was estimated by using Cramer's test. The analysis revealed decrease in annual as well as monsoon rainfall in the Brahmaputra valley during the last 110 years with large spatial and temporal variations. These decreasing trends of rainfall in the eastern part of the valley were statistically significant. Significant decreasing trend of monsoon rainfall during the recent 30-year period was due to significant decrease of July and September rainfall, and this trend was found to be consistent at different spatial scales. In the last decade (2001-2010) in particular, monsoon rainfall exhibited significant negative deviation from the normal due to three deficient years and absence of excess rainfall years. On the contrary, contribution of pre-monsoon and post-monsoon rainfall to annual total in the Brahmaputra valley increased during the recent 30-year period. Winter rainfall in the valley decreased during the last 30 years due to significant decrease of December rainfall in the eastern and central parts.

  12. Modeling Floodplain Dynamics: Can the Ganges-Brahmaputra Delta keep pace with 21st Century Sea Level Rise?

    Science.gov (United States)

    Rogers, K. G.; Overeem, I.

    2013-12-01

    The low-lying Ganges-Brahmaputra (G-B) Delta in Bangladesh is densely populated (~1200 people/km2) and could be flooded within the next century by rapid sea level rise and increased monsoonal rains. The G-B Rivers currently transport 1*109 tons of sediment from their basins in the Himalaya Mountains to the delta each year, with ~90% of the annual sediment load delivered during the Asian summer monsoon. Sediment distribution across the delta's surface by floods and coastal storms has kept pace with the rate of relative sea level rise along the Bengal coast, enabling the delta to maintain a positive elevation. However, ensemble Community Climate System Model experiments predict 11% higher monsoonal rainfall for the next century, potentially leading to extreme flooding events in the delta. Stratigraphic reconstructions show that sedimentation in the upper G-B floodplain was more than doubled under the Early Holocene enhanced monsoonal regime, suggesting that the delta may withstand an increase in monsoon intensity, flooding, and tropical cyclones that are currently predicted. Whether the G-B floodplains and coastal areas will ultimately drown under predicted sea level rise and monsoon intensification depends on a balance of aggradation, eustatic sea level rise and subsidence. To improve predictions of climatic forcing on aggradation rates in the lower G-B floodplain and coastal plain, direct sedimentation measurements collected in 2008 and 2012 in the lower delta are paired with a series of model components coupled within the Community Surface Dynamics Modeling System (CSDMS) Modeling Tool (CMT). We use three separate numerical models to simulate river basin sediment flux, floodplain sedimentation, and tidal-plain aggradation. The model inputs are based on available 20Th century climate and river gauge data, and outputs are compared to modern sedimentation rates within the G-B tidal delta and highly cultivated central coastal plain. The models are then used to test

  13. Geomorphology and Landscape Evolution Model for the natural and human-impacted regions of the Ganges-Brahmaputra-Meghna Delta

    Science.gov (United States)

    Wilson, C.; Goodbred, S. L.; Wallace Auerbach, L.; Ahmed, K.; Paola, C.; Reitz, M. D.; Pickering, J.

    2013-12-01

    The Ganges-Brahmaputra-Meghna delta (GBMD) in south Asia is generally considered a tide-dominated system, but much of the subaerial delta plain is geomorphically similar to river-dominated systems such as the Mississippi River delta, with a well-developed distributary network separated by low-lying, organic-rich interdistributary basins. By contrast, the lower GBMD is dominated by tidal processes and comprises a 100-km wide coastal plain with dense, interconnected tidal channels that are amalgamated to the seaward edge of the river-dominated portion of the delta. These distinct river- and tide-dominated geomorphic regions are simultaneously sustained by the enormous sediment load of the GBM rivers and its efficient dispersal via the distributary channel network and onshore advection by tides. Together these processes have resulted in the ability of the GBMD to keep pace with sea-level rise throughout the Holocene, with comparatively little shoreline transgression. However, topographic data from the Shuttle Radar Topography Mission (SRTM) highlight low-lying regions of the delta that are located at the interface of the river- and tide-dominated portions of the delta, where the transport energy of small distributaries and the upper tidal zone go to zero. As a result, these are the most sediment-starved regions of the delta and those most at risk to flooding by the summer monsoon and storm surges. Compounding the slow rates of sedimentation and high local organic content, these regions have been strongly affected by the construction of embankments (polders) that artificially de-water the soils and accelerate organic decomposition during the dry season, and further starve the land surface of sediment. Here, we present an integrated conceptual model for the geomorphic evolution of the GBMD that incorporates river- and tide-dominated regions in conjunction with channel-avulsion processes and delta-lobe construction. Each of these is also overprinted by tectonic

  14. Challenges and Approaches in River Delta Planning - report on training workshop

    NARCIS (Netherlands)

    Wosten, J.H.M.; Douven, W.; Long Phi, H.; Fida Abdullah Khan, M.

    2012-01-01

    River delta’s, like the Mekong Delta (Vietnam), Ganges-Brahmaputra Delta (Bangladesh), Irrawady (Myanmar) and Ciliwung Delta (Indonesia) are developing rapidly and characterized by large-scale urbanization and industrialization processes. They are facing serious planning challenges related to issues

  15. Spatial Pattern and Variation in Literacy among the Scheduled Castes Population in the Brahmaputra Valley, Assam

    Directory of Open Access Journals (Sweden)

    Dr Momita Goswami Barooah

    2014-06-01

    Full Text Available Scheduled Caste (SC population constitutes a sizeable portion of the total population of Assam accounting for 6.32 per cent according to the 2011 Census. They comprise a socially backward class in the Indian society—downtrodden illiterate people of the Indian social fabric. Literacy and educational attainment are considered the hallmark of a modern society. The traits of the modern society, such as, industrialisation, modernisation and urbanisation are closely associated with the level of literacy and education. In the middle part of the 20th century, the literacy rate among them was very low. However, in the later part of the 20th century and in the current millennium due to the developmental measures implemented by both the Central as well as State Governments of India and due to the influence of mass media, there has been a change in the pattern of literacy. The literacy rate of the SC population in the Brahmaputra Valley, Assam was 66.34 per cent in 2011 against 61.15 per cent for general population, which is slightly lower than the SC population in the Valley. The study of the pattern of literacy among various social groups of SCs in the study area provides an insight into the socio-economic situations. An attempt has been made in this paper to analyse the spatial pattern of literacy and its variations among the scheduled caste population in the Brahmaputra Valley, Assam.

  16. Delta Morphodynamics Matters! Ecosystem Services, Poverty and Morphodynamic Change in the Ganges-Brahmaputra Mega-Delta

    Science.gov (United States)

    Nicholls, R. J.; Adger, N.; Allan, A.; Darby, S. E.; Hutton, C.; Matthews, Z.; Rahman, M.; Whitehead, P. G.; Wolf, J.

    2013-12-01

    The world's deltas are probably the most vulnerable type of coastal environment, and they face multiple stresses in the coming decades. These stresses include, amongst others, local drivers due to land subsidence, population growth and urbanisation within the deltas, regional drivers due to changes in catchment management (e.g. upstream land use and dam construction), as well as global climate change impacts such as sea-level rise. At the same time, the ecosystem services of river deltas support high population densities, with around 14% of the global population inhabiting deltas. A large proportion of these people experience extremes of poverty and they are therefore severely exposed to vulnerability from environmental and ecological stress and degradation. In areas close to or below the poverty boundary, both subsistence and cash elements of the economy tend to rely disproportionately heavily on ecosystem services which underpin livelihoods. Therefore, to sustainably manage delta environments they must be viewed as complex social-environmental systems where change is only partially driven by physical drivers such as sea level rise and climate change, and human-induced development activities are also critical. Here we outline a new conceptual framework for the development of methods to understand and characterise the key drivers of change in ecosystem services that affect the environment and economic status of populous deltas, focusing specifically on the Ganges-Brahmaputra-Meghna (GBM) mega-delta. The GBM delta is characterised by densely populated coastal lowlands with significant poverty, with livelihoods supported to a large extent by natural ecosystems such as the Sunderbahns (the largest mangrove forest in the world). However, the GBM delta is under severe development pressure due to many growing cities. At present the importance of ecosystems services to poverty and livelihoods is poorly understood. This is due to due to the complexity of interactions

  17. Larval ecology and mosquito fauna of upper Brahmaputra valley, northeast India.

    Science.gov (United States)

    Khan, S A; Handique, R; Tewari, S C; Dutta, P; Narain, K; Mahanta, J

    1998-09-01

    Ninety-one mosquito species in 15 genera were collected from 22 habitat types of Upper Brahmaputra valley in Assam and bordering areas of Arunachal Pradesh. Nineteen species have been recorded for the first time in Assam including seven first records from the northeast region and three first country records. Jaccard's coefficient was used to quantify the similarity between 13 different geographical localities surveyed on the basis of their mosquito fauna. Group average sorting (UPGMA) cluster analysis was used to find out relationship between Jonai, Dhemaji, Dibrugarh, Tinsukia and north Lakhimpur (study zones) on the basis of their mosquito community. Immatures of three malaria vectors incriminated from the northeast India, viz. Anopheles dirus, An. minimus and An. philippinensis were collected exclusively from forest areas. Fourteen potential vectors of Japanese encephalitis incriminated from elsewhere in India were collected during the study. PMID:10497839

  18. Uranium in river water

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, M.R. (Univ. of Bristol (United Kingdom)); Edmond, J.M. (Massachusetts Inst. of Technology, Cambridge, MA (United States))

    1993-10-01

    The concentration of dissolved uranium has been determined in over 250 river waters from the Orinoco, Amazon, and Ganges basins. Uranium concentrations are largely determined by dissolution of limestones, although weathering of black shales represents an important additional source in some basins. In shield terrains the level of dissolved U is transport limited. Data from the Amazon indicate that floodplains do not represent a significant source of U in river waters. In addition, the authors have determined dissolved U levels in forty rivers from around the world and coupled these data with previous measurements to obtain an estimate for the global flux of dissolved U to the oceans. The average concentration of U in river waters is 1.3 nmol/kg, but this value is biased by very high levels observed in the Ganges-Brahmaputra and Yellow rivers. When these river systems are excluded from the budget, the global average falls to 0.78 nmol/kg. The global riverine U flux lies in the range of 3-6 [times] 10[sup 7] mol/yr. The major uncertainty that restricts the accuracy of this estimate (and that of all other dissolved riverine fluxes) is the difficulty in obtaining representative samples from rivers which show large seasonal and annual variations in runoff and dissolved load.

  19. Remote Sensing and River Discharge Forecasting for Major Rivers in South Asia (Invited)

    Science.gov (United States)

    Webster, P. J.; Hopson, T. M.; Hirpa, F. A.; Brakenridge, G. R.; De-Groeve, T.; Shrestha, K.; Gebremichael, M.; Restrepo, P. J.

    2013-12-01

    The South Asia is a flashpoint for natural disasters particularly flooding of the Indus, Ganges, and Brahmaputra has profound societal impacts for the region and globally. The 2007 Brahmaputra floods affecting India and Bangladesh, the 2008 avulsion of the Kosi River in India, the 2010 flooding of the Indus River in Pakistan and the 2013 Uttarakhand exemplify disasters on scales almost inconceivable elsewhere. Their frequent occurrence of floods combined with large and rapidly growing populations, high levels of poverty and low resilience, exacerbate the impact of the hazards. Mitigation of these devastating hazards are compounded by limited flood forecast capability, lack of rain/gauge measuring stations and forecast use within and outside the country, and transboundary data sharing on natural hazards. Here, we demonstrate the utility of remotely-derived hydrologic and weather products in producing skillful flood forecasting information without reliance on vulnerable in situ data sources. Over the last decade a forecast system has been providing operational probabilistic forecasts of severe flooding of the Brahmaputra and Ganges Rivers in Bangldesh was developed (Hopson and Webster 2010). The system utilizes ECMWF weather forecast uncertainty information and ensemble weather forecasts, rain gauge and satellite-derived precipitation estimates, together with the limited near-real-time river stage observations from Bangladesh. This system has been expanded to Pakistan and has successfully forecast the 2010-2012 flooding (Shrestha and Webster 2013). To overcome the in situ hydrological data problem, recent efforts in parallel with the numerical modeling have utilized microwave satellite remote sensing of river widths to generate operational discharge advective-based forecasts for the Ganges and Brahmaputra. More than twenty remotely locations upstream of Bangldesh were used to produce stand-alone river flow nowcasts and forecasts at 1-15 days lead time. showing that

  20. Spatial heterogeneity in near surface aerosol characteristics across the Brahmaputra valley

    Indian Academy of Sciences (India)

    Binita Pathak; Arup Borgohain; Pradip Kumar Bhuyan; Shyam Sundar Kundu; S Sudhakar; Mukunda M Gogoi; Toshihiko Takemura

    2014-06-01

    In order to examine the spatial variability of the aerosol characteristics across the Brahmaputra valley, a land campaign was conducted during late winter (February 3–March 2) 2011. Measurements of particulate matter (PM, PM10, PM2.5) and black carbon (BC) concentrations were made onboard an interior redesigned vehicle. The length of the campaign trail stretched about 700 km, covering the longitude belt of 89.97°–95.55°E and latitude belt of 26.1°–27.6°N, comprising 13 measurement locations. The valley is divided into three sectors longitudinally: western sector (R1: 89.97°–91.75°E), middle sector (R2: 92.5°–94.01°E) and eastern sector (R3: 94.63°–95.55°E). Spatial heterogeneity in aerosol distribution has been observed with higher PM10 and PM2.5 concentrations at the western and middle sectors compared to the eastern sector. The locations in the western sector are found to be rich in BC compared to the other two sectors and there is a gradual decrease in BC concentrations from west to east of the Brahmaputra valley. Two hotspots within the western and middle sectors with high PM and BC concentrations have been identified. The associated physico-optical parameters of PM reveal abundance of PM2.5 aerosols along the entire valley. High population density in the western and middle sectors, together with the contribution of remote aerosols, leads to higher anthropogenic aerosols over those regions. Spectral Radiation-Transport Model for Aerosol Species (SPRINTARS) slightly underestimates the measured PM10 and PM2.5 at the eastern sector while the model overestimates the measurements at a number of locations in the western sector. In general, BC is underestimated by the model. The variation of BC within the campaign trail has not been adequately captured by the model leading to higher variance in the western locations as compared to the middle and eastern locations.

  1. Histoire tertiaire de l'Arche de Brahmaputra ; son rôle dans la prospection des hydrocarbures du Haut Assam (Inde (résumé Tertiary History of Brahmaputra Arch. Its Role in Hydrocarbon Prospects of Upper Assam, India (Abstract

    Directory of Open Access Journals (Sweden)

    Murty K. N.

    2006-10-01

    sub-surface regional structure of the present Upper Assam Valley is a broad arch - Brahmaputra arch - parallel to and just a little south of Brahmaputra river, formed by two opposite tiltings: an initial palaeoslope towards south-east during Palaeocene-Oligocene and the other towards north-west during Mio-Pliocene. Two phases of migration of hydrocarbons con be recognised. The study enables assessment of future hydrocarbon prospects in Upper Assam. This arch has similar geological history as that of Bend-arch of north-central Texas and Huffon-Seminole-Ozark Arch of Oklahoma where rich pools have been found in nearby oil the rocks involved in the arching.

  2. Sustainability Within the Great Monsoon River Basins

    Science.gov (United States)

    Webster, P. J.

    2014-12-01

    For over five millenia, the great monsoon river basins of the Ganges, Brahmaputra and Indus have provided for great and flourishing agrarian civilizations. However, rapid population growth and urbanization have placed stress on the rural sector causing the use of land that is more prone for flood and drought. In addition, increased population and farming have stressed the availability of fresh water both from rivers and aquifers. Additionally, rapid urbanization has severely reduced water quality within the great rivers. Added to these problems is delta subsidence from water withdrawal that, at the moment far surpasses sea level rise from both natural and anthropogenic effects. Finally, there appear to be great plans for river diversion that may reduce fresh water inflow into the Brahmaputra delta. All of these factors fall against a background of climate change, both anthropogenic and natural, of which there is great uncertainty. We an attempt a frank assessment assessment of the sustainability of society in the great basins and make some suggestions of factors that require attention in the short term.

  3. Inequalities in Human Well-Being in the Urban Ganges Brahmaputra Meghna Delta

    Directory of Open Access Journals (Sweden)

    Sylvia Szabo

    2016-06-01

    Full Text Available The recently endorsed Sustainable Development Goals (SDGs agenda unanimously agrees on the need to focus on inclusive development, the importance of eradicating extreme poverty and managing often complex human well-being impacts of rapid urban growth. Sustainable and inclusive urbanisation will accelerate progress towards the SDGs and contribute to eradicating extreme poverty. In tropical delta regions, such as the Ganges Brahmaputra Meghna delta region, urban growth and resulting intra-urban inequalities are accelerated by the impact of environmental and climate change. In this context, the present study uses the 2010 Household Income and Expenditure Survey to analyse the extent of wealth-based inequalities in human well-being in the urban delta region and the determinants of selected welfare measures. The results suggest that the extent of intra-urban inequalities is greatest in educational attainment and access to postnatal healthcare and relatively low in the occurrence of gastric disease. The paper concludes by providing policy recommendations to reduce increasing wealth inequalities in urban areas, thus contributing to sustainable development of the region.

  4. Construction and maintenance of the Ganges-Brahmaputra-Meghna delta: linking process, morphology, and stratigraphy.

    Science.gov (United States)

    Wilson, Carol A; Goodbred, Steven L

    2015-01-01

    We present a review of the processes, morphology, and stratigraphy of the Ganges-Brahmaputra-Meghna delta (GBMD), including insights gained from detailed elevation data. The review shows that the GBMD is best characterized as a composite system, with different regions having morphologic and stratigraphic attributes of an upland fluvial fan delta; a lowland, backwater-reach delta; a downdrift tidal delta plain; and an offshore subaqueous-delta clinoform. These distinct areas of upland and lowland fluvial reaches and tidal dominance vary in time and space, and we distinguish late-Holocene phases of delta construction, maintenance, and decline similar to delta-lobe cycling in other systems. The overall stability of the GBMD landform, relative to many deltas, reflects the efficient, widespread dispersal of sediment by the large monsoon discharge and high-energy tides that affect this region. However, we do identify portions of the delta that are in decline and losing elevation relative to sea level owing to insufficient sediment delivery. These areas, some of which are well inland of the coast, represent those most at risk to the continued effect of sea-level rise. PMID:25251271

  5. Hydrodynamic Properties of a Large Tidal Channel on the Ganges-Brahmaputra Delta, Bangladesh, with Implications for Channel Morphology and Sediment Transport

    Science.gov (United States)

    Bain, R. L.; Goodbred, S. L., Jr.; Hale, R. P.; Reed, M. J.; Best, J.

    2015-12-01

    The Ganges-Brahmaputra Delta hosts a dense network of tidal channels extending inland as far as 100 kilometers from the coast. With semidiurnal tides up to 6.7 meters in amplitude, this setting is ideal for testing hypotheses related to tidal meander morphology, intertidal sediment transport, and channel-platform linkages. We present results from two field surveys in March and September 2015, corresponding to the dry and monsoon seasons, respectively. Comparing acoustic Doppler current profiler (ADCP) data and pressure sensor measurements from the Sibsa River in southwest Bangladesh reveals a phase lag of as much as 1 hour between maximum discharge and mean water level. Variations in this phase lag at different points along the channel allow us to test an existing conceptual model of cuspate tidal meander formation. To address a related but separate question, we observe that the ratio of cumulative discharges Qin/Qout is approximately equal during both spring and neap tides at a strategically-placed ADCP transect south of the study area. In contrast, ADCP data obtained north of the study area shows that Qin/Qout=1.4 during spring tides and 0.85 during neap tides. We examine the degree to which this phenomenon is controlled by the establishment of a hydraulic gradient between the Sibsa and a parallel tidal channel, the Pussur, versus the exchange of water between the channel and the tidal flats during the ebb-flood cycle. These results have implications for identifying loci of sediment erosion and deposition within the network.

  6. Comparing and contrasting observed adaptations in three deltas: the Ganges-Meghna-Brahmaputra, Mahanadi and Volta

    Science.gov (United States)

    Nicholls, R. J.; Suckall, N.; Mensah, A.; Mondal, S.; Dey, S.; Hazra, S.

    2015-12-01

    In low and middle-income countries, many deltaic communities directly depend on the natural environment for income and well-being. Current environmental concerns that threaten deltaic communities, such as increasing salinity, sedimentation, erosion and subsidence are likely to be exacerbated by climate change and variability, for example sea-level rise, increased storminess and rising temperatures. Such changes, along with other social and environmental stressors, mean that communities must adapt. This paper outlines findings of a systematic review of the peer-reviewed and grey literature that examines observed adaptations in three deltas of differing sizes in various geographical contexts: the Ganges-Meghna-Brahmaputra in India and Bangladesh, the Mahanadi in India, and the Volta in Ghana. It compares and contrasts various elements of observed adaptations, including who is driving the adaptation, the beneficiaries, barriers to participation and evidence for maladaptation. The predominant drivers of adaptation vary from government (at state level in India and national level in Bangladesh) and NGOs (in Ghana). Autonomous adaptations are not widely reported in the literature from any of the deltas. In all three deltas there is a focus on supporting adaptation in farming rather than fishing; despite the fact that fisheries contribute to local food security as well as national economies. Lack of access to financial, natural, physical and human capital are common barriers to adaptation in all three deltas. Additionally the Indian literature in particular highlights the lack of coordination between different government departments, coupled with an excessively top-down (state-driven) approach to adaptation. Maladaptation is most commonly reported in the literature from Bangladesh, for example, loss of employment of inland fishermen in embanked areas. The paper concludes by highlighting some of the implications of these findings for adaptation policy in deltas.

  7. Holocene climatic fluctuations from Lower Brahmaputra flood plain of Assam, northeast India

    Indian Academy of Sciences (India)

    Swati Dixit; S K Bera

    2012-02-01

    Pollen analysis of a 3.2-m deep sedimentary profile cored from the Dabaka Swamp, Nagaon District, Lower Brahmaputra flood plain, Assam has revealed persistent fluvial activity during 14,120–12,700 cal years BP which may be attributed to the paucity of pollen and spores with encounterance of fluvial marker taxa like Ludwigia octavalvis and Botryococcus. Later, fluvial activity was succeeded by the tropical tree savanna under cool and dry climate between 12,700 and 11,600 cal years BP corresponding to that of global Younger Dryas. Between 11,600 and 8310 cal years BP, relatively less cool and dry climate prevailed with inception of tropical mixed deciduous taxa like Shorea robusta and Lagerstroemia parviflora. This phase is further followed by a fluvial activity between 8310 and 7100 cal years BP as evidenced by trace values of pollen and spores. Fluvial activity was further succeeded by enrichment of tropical mixed deciduous forest under warm and humid climatic regime between 7100 and 1550 cal years BP which is well-matched with the peak period of the Holocene climatic optimum. However, during 1550–768 cal years BP, final settlement of tropical mixed deciduous forest occurred under increased warm and humid climate followed by deterioration in tropical mixed deciduous forest under warm and relatively dry climatic regime since 768 cal years BP onwards due to acceleration in human settlement as evidenced by Cerealia. Increase in Melastoma, Ziziphus and Areca catechu imply forest clearance at this phase. The occurrence of degraded pollen-spore along with adequate fungal elements especially, Xylaria, Nigrospora and Microthyriaceous fruiting body is suggestive of aerobic microbial digenesis of rich organic debris during sedimentation.

  8. ANTHROPOGENIC INFLUENCE ON FLOW AND SEDIMENT REGIME OF A RIVER BASIN

    Directory of Open Access Journals (Sweden)

    BALESHWAR SINGH

    2012-01-01

    Full Text Available The Brahmaputra river basin in India is at present undergoing rapid agricultural, industrial and economic development with more than 30 million people living within this part of the major basin. The presentstudy examines impacts of some of the anthropogenic activities that are responsible for the disturbances to the flow and sediment regime as well as to the biogeochemical flux of nutrients through the river. The study also throws light on some aspects of the climatic change of the north-eastern region of India in particular, because of the considerable effect of the monsoon over the flow regime of the river.

  9. Agricultural Land Cover Dynamics on the Ganges-Brahmaputra Delta: 1988-2014

    Science.gov (United States)

    Sousa, D.; Chiu, S.; Mondal, D. R.; Small, C.

    2014-12-01

    We seek to understand spatiotemporal (ST) patterns of agricultural land cover dynamics on the lower Ganges-Brahmaputra Delta (GBD). Recent availability of accurately coregistered, radiometrically intercalibrated Landsat TM, ETM+ and OLI imagery collected since 1988 allows for synoptic scale ST analyses of vegetation phenology. We use multitemporal spectral mixture analysis of exoatmospheric reflectance to represent land cover and water bodies as continuous fields of soil and sediment substrates (S), vegetation (V), and dark surfaces (D; water & shadow). This study analyses 61 cloud-free Landsat acquisitions across two geographic scenes to identify ST patterns of winter cropping and interconversion between agricultural fields and ponds used for aquaculture. We also use MODIS 16-day EVI composite time series post-2000 and high spatial resolution imagery to extend and vicariously validate the Landsat-derived observations. We use temporal moment spaces (derived from temporal mean, standard deviation, and skewness) and temporal feature spaces (derived from spatial Principal Components) to characterize the full range of phenological patterns observed at 30 m scales throughout the lower delta. For each year with sufficient cloud-free coverage, we distinguish between areas with a high likelihood of use for aquaculture versus areas with a high likelihood of use for agriculture based on a combination of reflectance and phenology. From changes in these patterns we infer changes in land use on seasonal to interannual timescales. Many of the phenological patterns we observe occur on the scale of individual polders, suggesting decision making at community scales. While there appears to be considerable loss of agricultural land to aquaculture in many areas of the lower delta, we also observe intensification of dry season cropping in other areas. MODIS reveals frequent instances of both gradual and abrupt decreases in seasonal peak EVI as well as many localized instances of abrupt

  10. Natural attenuation processes of arsenic in the groundwater of the Brahmaputra floodplain of Assam, India.

    Science.gov (United States)

    Sailo, Lalsangzela; Mahanta, Chandan

    2016-01-01

    Natural attenuation of higher arsenic (As) concentration in the groundwater of the Brahmaputra valley of Assam can be a viable option for its remediation. The assessment of attenuation capacities in aquifers was done using three sediment core samples (namely C_50, C_70 and C_150) representing the commonly found sediments and characterized as viz. reduced, oxidized and moderately oxidized sediments, respectively. The feasability of aquifers to release low As water depends on the sorption capacity of the sediments to directly adsorbed as As(III) and/or oxidation to As(V) on oxidative sites. The various batch sorption experiments along with competition of other anions for adsorption sites at different concentrations were investigated. The sediments were observed to adsorb both As(III) and As(V) with varying magnitudes depending on the species of As, pH and concentrations of competing anions. The Elovich kinetic model best described kinetic test data. The oxidized sediment (C_70) with the highest Fe and Mn content has the highest adsorption capacity. The competition for adsorption sites with As(V) in the sediment samples followed the order PO4(3-) > SiO2 > HCO3(-). The oxidation of As(III) to As(V) by the sediments was analyzed as it is also the most effective pathway to reduce the toxicity as well as the mobility of As in the subsurface environment. Sediment C_70 showed the highest potential to oxidize As(III) to As(V) in the oxidative sites of the sediments. The removal of As(III) in the oxidative site via As(V) was the dominant As removal mechanism for the oxidized sediment (C_70) and moderately oxidized sediment (C_150) than the direct adsorption of As(III) on the adsorptive sites as on reduced sediment sample C_50. Therefore, targeting the oxidized sediment with a high concentration of Fe-oxides and Mn-oxides might make natural attenuation of As viable in the study areas. PMID:26647841

  11. Controls on the Flux, Age, and Composition of Terrestrial Organic Carbon Exported by Rivers to the Ocean

    Science.gov (United States)

    Galy, Valier; Peucker-Ehrenbrink, Bernhard; Eglinton, Timothy; Holmes, Robert; Soule, Adam; Goetz, Scott; Laporte, Nadine; Wollheim, Wilfred

    2010-05-01

    Export of organic carbon, alkalinity and silicate-derived Ca and Mg ions to the ocean exerts critical controls on the sequestration of atmospheric carbon. As this export is mediated to a significant extent by river systems, understanding processes that control transport of land-derived matter to the coastal ocean is of fundamental importance to successful models of past and future climates. Scientists from the Woods Hole Oceanographic Institution, the Woods Hole Research Center and the University of New Hampshire have formed a river research consortium that aims at investigating large river systems with a holistic approach. The National Science Foundation is funding this initiative through its Emerging Topics in Biogeochemical Cycles (ETBC) program. Our project focuses on the biogeochemistries of the Lena and Kolyma rivers in the Russian Arctic, the Yangtze river in China, the Ganges and Brahmaputra rivers in India and Bangladesh, the Congo river in central Africa as well as the Fraser river basin in western Canada. Campaign-style sampling using a uniform sampling strategy is complemented by time-series sampling that is accomplished through collaborations with scientists at local institutions such as the East China Normal University in Shanghai (Yangtze), the University of the Fraser Valley in Abbotsford (Fraser), schools and research institutions in eastern Russia (Lena and Kolyma) and the University of Nancy, France (Ganges, Brahmaputra). We combine a standardized sampling approach for organic and inorganic constituents with spatial analyzes of digital, mostly satellite-based data products with the aim of obtaining an integrated understanding of the response of river ecosystems to past, ongoing and future environmental changes. We will present first results with a special emphasis on the age of terrestrial organic carbon exported by the Ganges-Brahmaputra river system.

  12. Hydrological Cycle over South and Southeast Asian River Basins as Simulated by PCMDI/CMIP3 Experiments

    CERN Document Server

    Hasson, Shabeh ul; Pascale, Salvatore

    2013-01-01

    We investigate how CMIP3 climate models describe the hydrological cycle over four major South Asian river basins (Indus, Ganges, Brahmaputra and Mekong) for the XX, XXI, and XXII centuries. For the XX century, models simulated water balance and total runoff quantities are neither consistent with the observed mean river discharges nor among the models. Most of the models underestimate the water balance for the Ganges, Brahmaputra and Mekong basin and overestimate it for the Indus basin. The only modest inter-model agreement is found for the Indus basin in terms of precipitation, evaporation and the strength of the hydrological cycle and for the Brahmaputra basin in terms of evaporation. While some models show inconsistencies for the Indus and the Ganges basins, most of the models seem to conserve water at the river basin scale up to a good degree of approximation. Models agree on a negative change of the water balance for Indus and a positive change in the strength of the hydrological cycle, whereas for Brahma...

  13. Sr fluxes and isotopic compositions of the eleven rivers originating from the Qinghai-Tibet Plateau and their contributions to 87Sr/86Sr evolution of seawater

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    To evaluate influence of chemical weathering of the Qinghai-Tibet Plateau (QTP) on seawater 87Sr/86Sr variation, river water and sediment samples were collected, and their Sr concentrations and isotopic compositions analyzed, from the seven large rivers that originated from the QTP. By combining these with the data of the Ganges, Brahmaputra, Indus and Irrawaddy originated in the southern QTP, the total Sr flux of the eleven rivers reaches 3.47×109 mol·a-1, which accounts for 10.2% of the total Sr flux transported by the global rivers. The weighted mean 87Sr/86Sr is 0.71694, higher than the average value of the global rivers. The 87Srex (87Sr flux in excess of the seawater 87Sr/86Sr ratio) of the Chinese seven rivers is 1.55×106 mol·a-1, only accounting for about 6% of the value of the eleven rivers originated from QTP, and the Ganges-Brahmaputra system accounts for 86%. We assume that the QTP rivers have no strontium contributions to the oceans before ~40 Ma and the Sr fluxes of the global rivers, except the QTP eleven rivers, are constant, then a maximum linear increase in Sr fluxes of the QTP rivers from zero to the modern value in response to tectonic uplift can explain ~69% increase of seawater 87Sr/86Sr over the past ~40 Ma and the remainder of 31% is perhaps provided from other factors.

  14. Upstream Satellite Remote Sensing for River Discharge Forecasting: Application to Major Rivers in South Asia

    Science.gov (United States)

    Hopson, Thomas; Hirpa, Feyera; Brakenridge, G. Robert; Webster, Peter J.; De Groeve, Tom; Gebremichael, Mekonnen; Restrepo, Pedro

    2013-04-01

    In this work we demonstrate the utility of satellite remote sensing for river discharge nowcasting and forecasting for two major rivers, the Ganges and Brahmaputra, in southern Asia. Passive microwave sensing of the river and floodplain at more than twenty locations upstream of Hardinge Bridge (Ganges) and Bahadurabad (Brahmaputra) gauging stations are used to: 1) evaluate their use in producing stand-alone river flow nowcasts, and forecasts at 1-15 days lead time; and 2) how they can be combined to improve the skill of an ongoing ensemble weather forecast-based flood forecasting system. The pattern of correlation between upstream satellite data and in situ observations of downstream discharge is used to estimate wave propagation time. This pattern of correlation is combined with a cross-validation method to select the satellite sites that produce the most accurate river discharge estimates in a lagged regression model. The results show that the well-correlated satellite-derived flow (SDF) signals were able to detect the propagation of a river flow wave along both river channels. The daily river discharge (contemporaneous) nowcast produced from the upstream SDFs could be used to provide missing data estimates given its Nash-Sutcliffe coefficient of 0.8 for both rivers; and forecasts have considerably better skill than autoregressive moving-average (ARMA) model beyond 3-day lead time for Brahmaputra. Due to the expected better accuracy of the SDF for detecting large flows, the forecast error is found to be lower for high flows compared to low flows. Overall, we conclude that satellite-based flow estimates are a useful source of dynamical surface water information in data-scarce regions and that they could be used for model calibration and data assimilation purposes in near-time hydrologic forecast applications. The paper concludes by explore the utility of the SDF's in improving the skill of the existing Climate Forecasting Applications for Bangladesh (CFAB

  15. Integrated water resources management : constraints and opportunities with a focus on the Ganges and the Brahmaputra River Basins

    OpenAIRE

    Rahaman, Mizanur Muhammad

    2009-01-01

    The key aims of this thesis are to identify the constraints and opportunities of implementing the integrated water resources management (IWRM) concept at both the policy and field level. IWRM has been chosen as a focus of this study as all contemporary international conferences, summits, regional water policies and declarations promote the IWRM concept for the effective and efficient management of water resources. The thesis has two parts. The first part reviews the evolution of the IWRM...

  16. Hydrological cycle over south and southeast Asian river basins as simulated by PCMDI/CMIP3 experiments

    Directory of Open Access Journals (Sweden)

    S. Hasson

    2013-01-01

    Full Text Available We investigate how CMIP3 climate models describe the hydrological cycle over four major South and Southeast Asian river basins (Indus, Ganges, Brahmaputra and Mekong for the XX, XXI, and XXII centuries. For the XX century, models' simulated water balance and total runoff quantities are neither consistent with the observed mean river discharges nor among the models. Most of the models underestimate the water balance for the Ganges, Brahmaputra and Mekong basin and overestimate it for the Indus basin. The only modest inter-model agreement is found for the Indus basin in terms of precipitation, evaporation and the strength of the hydrological cycle and for the Brahmaputra basin in terms of evaporation. While some models show inconsistencies for the Indus and the Ganges basins, most of the models seem to conserve water at the river basin scale up to a good degree of approximation. Models agree on a negative change of the water balance for Indus and a positive change in the strength of the hydrological cycle, whereas for Brahmaputra, Mekong and Ganges, most of the models project a positive change in both quantities. Most of the models foresee an increase in the inter-annual variability of the water balance for the Ganges and Mekong basins which is consistent with the projected changes in the Monsoon precipitation. No considerable future change in the inter-annual variability of water balance is found for the Indus basin, characterized by a more complex meteorology, because its precipitation regime is determined not only by the summer monsoon but also by the winter mid-latitude disturbances.

  17. Where Land and River Meet: A Study of Disaster at the Riparian Zone of Majuli Island

    Science.gov (United States)

    Sahay, Avijit

    2016-04-01

    Situated on the River Brahmaputra in the Indian state of Assam, and inscribed as a Cultural Heritage site by the UNESCO, Majuli, one of the largest and most populated riverine islands in the world has for long been considered a cultural and spiritual capital of Assam. Shankerdeb, the famous 15th century social and religious reformer of Assam started the Vaishnavite cult in this island, and to this date, it is the center of Vaishnavite Hinduism in India. However, in 1950, a powerful earthquake struck the Brahmaputra Valley of Assam, turning this life giving river into a harbinger of disaster for the island. Post-earthquake, the river has been flooding and eroding the riverbank at an alarming rate. Preliminary studies have shown that between one-third to two-third area of original land has been lost to the river. This has caused a large number of its 167,304 persons to become migrants in their own land. Clearly, a human tragedy is unfolding at the site where land and river meet. The present study is an attempt to quantify this human tragedy by using Remote Sensing images and techniques to find out the exact extent of damage done by the river and to qualify the tragedy by finding out the impact of riverbank erosion on the culture, society, and economy of the island through fieldwork and primary survey.

  18. Heavy metals fractionation in Ganga River sediments, India.

    Science.gov (United States)

    Purushothaman, P; Chakrapani, G J

    2007-09-01

    The Ganga River is the largest river in India which, originates in the Himalayas and along with the Brahmaputra River, another Himalayan river, transports enormous amounts of sediments from the Indian sub-continent to the Bay of Bengal. Because of the important role of river sediments in the biogeochemical cycling of elements, the Ganga river sediments, collected from its origin to the down stretches, were studied in the present context, to assess the heavy metals associated with different chemical fractions of sediments. The fractionation of metals were studied in the sediments using SM&T protocol for the extraction of heavy metals and geo-accumulation index (GAI) (Muller, Schwermetalle in den sedimenten des rheins - Veranderungen seit. Umschau, 79, 778-783, 1979) and Metal Enrichment Factor (MEF) in different fractions were calculated. As with many river systems, residual fractions constitute more than 60% of total metals, except Zn, Cu and Cr. However, the reducible and organic and sulfide components also act as major sinks for metals in the down stretches of the river, which is supported by the high GAI and MEF values. The GAI values range between 4 and 5 and MEF exceed more than 20 for almost all the locations in the downstream locations indicating to the addition of metals through urban and industrial effluents, as compared to the low metals concentrations with less GAI and MEF in the pristine river sediments from the rivers in Himalayas.

  19. Heavy metals fractionation in Ganga River sediments, India.

    Science.gov (United States)

    Purushothaman, P; Chakrapani, G J

    2007-09-01

    The Ganga River is the largest river in India which, originates in the Himalayas and along with the Brahmaputra River, another Himalayan river, transports enormous amounts of sediments from the Indian sub-continent to the Bay of Bengal. Because of the important role of river sediments in the biogeochemical cycling of elements, the Ganga river sediments, collected from its origin to the down stretches, were studied in the present context, to assess the heavy metals associated with different chemical fractions of sediments. The fractionation of metals were studied in the sediments using SM&T protocol for the extraction of heavy metals and geo-accumulation index (GAI) (Muller, Schwermetalle in den sedimenten des rheins - Veranderungen seit. Umschau, 79, 778-783, 1979) and Metal Enrichment Factor (MEF) in different fractions were calculated. As with many river systems, residual fractions constitute more than 60% of total metals, except Zn, Cu and Cr. However, the reducible and organic and sulfide components also act as major sinks for metals in the down stretches of the river, which is supported by the high GAI and MEF values. The GAI values range between 4 and 5 and MEF exceed more than 20 for almost all the locations in the downstream locations indicating to the addition of metals through urban and industrial effluents, as compared to the low metals concentrations with less GAI and MEF in the pristine river sediments from the rivers in Himalayas. PMID:17295113

  20. Lithium isotopes in large rivers reveal the cannibalistic nature of modern continental weathering and erosion

    Science.gov (United States)

    Dellinger, Mathieu; Gaillardet, Jérôme; Bouchez, Julien; Calmels, Damien; Galy, Valier; Hilton, Robert G.; Louvat, Pascale; France-Lanord, Christian

    2014-09-01

    The erosion of major mountain ranges is thought to be largely cannibalistic, recycling sediments that were deposited in the ocean or on the continents prior to mountain uplift. Despite this recognition, it has not yet been possible to quantify the amount of recycled material that is presently transported by rivers to the ocean. Here, we have analyzed the Li content and isotope composition (δLi7) of suspended sediments sampled along river depth profiles and bed sands in three of the largest Earth's river systems (Amazon, Mackenzie and Ganga-Brahmaputra rivers). The δLi7 values of river-sediments transported by these rivers range from +5.3 to -3.6‰ and decrease with sediment grain size. We interpret these variations as reflecting a mixture of unweathered rock fragments (preferentially transported at depth in the coarse fraction) and present-day weathering products (preferentially transported at the surface in the finest fraction). Only the finest surface sediments contain the complementary reservoir of Li solubilized by water-rock interactions within the watersheds. Li isotopes also show that river bed sands can be interpreted as a mixture between unweathered fragments of igneous and sedimentary rocks. A mass budget approach, based on Li isotopes, Li/Al and Na/Al ratios, solved by an inverse method allows us to estimate that, for the large rivers analyzed here, the part of solid weathering products formed by present-day weathering reactions and transported to the ocean do not exceed 35%. Li isotopes also show that the sediments transported by the Amazon, Mackenzie and Ganga-Brahmaputra river systems are mostly sourced from sedimentary rocks (>60%) rather than igneous rocks. This study shows that Li isotopes in the river particulate load are a good proxy for quantifying both the erosional rock sources and the fingerprint of present-day weathering processes. Overall, Li isotopes in river sediments confirm the cannibalistic nature of erosion and weathering.

  1. Sr fluxes and isotopic compositions of the eleven rivers originating from the Qinghai-Tibet Plateau and their contributions to 87Sr/86Sr evolution of seawater

    Institute of Scientific and Technical Information of China (English)

    WU WeiHua; YANG JieDong; XU ShiJin; LI GaoJun; YIN HongWei; TAO XianCong

    2009-01-01

    To evaluate influence of chemical weathering of the Qinghai-Tibet Plateau (QTP) on seawater 87Sr/66Srvariation, river water and sediment samples were collected, and their Sr concentrations and isotopic compositions analyzed, from the seven large rivers that originated from the QTP. By combining these with the data of the Ganges, Brahmaputra, Indus and Irrawaddy originated in the southern QTP, the total transported by the global rivers. The weighted mean 87Sr/86Sr is 0.71694, higher than the average value of the global rivers. The 87Srex (87Sr flux in excess of the seawater 87Sr/66Sr ratio) of the Chinese seven QTP, and the Ganges-Brahmaputra system accounts for 86%. We assume that the QTP rivers have no strontium contributions to the oceans before -40 Ma and the Sr fluxes of the global rivers, except the QTP eleven rivers, are constant, then a maximum linear increase in Sr fluxes of the QTP rivers from zero to the modern value in response to tectonic uplift can explain -69% increase of seawater 87Sr/86Sr over the past -40 Ma and the remainder of 31% is perhaps provided from other factors.

  2. Effect of lambda cyhalothrin on Calothrix sp. (GUEco 1001), an autochthonous cyanobacterium of rice fields of Brahmaputra floodplain.

    Science.gov (United States)

    Gupta, Kiran; Baruah, P P

    2015-12-01

    Pesticide contamination in the rice fields has manifested into a serious global environmental concern. Application of pesticides in the rice fields has deleterious effects on non-target organisms including nitrogen-fixing cyanobacteria which help to maintain the rice field fertility. In the present research endeavor, the effect of lambda cyhalothrin (5% EC), a synthetic pyrethroid insecticide, has been studied on the growth and pigments content of Calothrix sp. (GUEco 1001), an indigenous strain isolated from rice grown areas of Brahmaputra floodplain. To study the toxic effect of lambda cyhalothrin, the test organism was exposed to varying concentrations of the insecticide i.e., 20 ppm, 40 ppm, 80 ppm, and 160 ppm based upon the determination of LC50 for a period of 20 days. The result obtained in the laboratory showed a progressive decrease in the growth and pigments content by the test organism with increasing concentrations of the lambda cyhalothrin against time dose-dependent manner. At high dose (160 ppm), the test organism showed significant decrease in dry weight biomass (54.5%), chlorophyll-a (68%), carotenoids (38%), phycocyanin (80%), and nitrogen contents (55%) over the control. A little but insignificant stimulatory effect on growth and chlorophyll-a contents was recorded in 20 ppm treatment of the insecticide that, however, was reversed in case of carotenoids and phycocyanin contents. PMID:26377968

  3. A first look at the influence of anthropogenic climate change on the future delivery of fluvial sediment to the Ganges-Brahmaputra-Meghna delta.

    Science.gov (United States)

    Darby, Stephen E; Dunn, Frances E; Nicholls, Robert J; Rahman, Munsur; Riddy, Liam

    2015-09-01

    We employ a climate-driven hydrological water balance and sediment transport model (HydroTrend) to simulate future climate-driven sediment loads flowing into the Ganges-Brahmaputra-Meghna (GBM) mega-delta. The model was parameterised using high-quality topographic data and forced with daily temperature and precipitation data obtained from downscaled Regional Climate Model (RCM) simulations for the period 1971-2100. Three perturbed RCM model runs were selected to quantify the potential range of future climate conditions associated with the SRES A1B scenario. Fluvial sediment delivery rates to the GBM delta associated with these climate data sets are projected to increase under the influence of anthropogenic climate change, albeit with the magnitude of the increase varying across the two catchments. Of the two study basins, the Brahmaputra's fluvial sediment load is predicted to be more sensitive to future climate change. Specifically, by the middle part of the 21(st) century, our model results suggest that sediment loads increase (relative to the 1981-2000 baseline period) over a range of between 16% and 18% (depending on climate model run) for the Ganges, but by between 25% and 28% for the Brahmaputra. The simulated increase in sediment flux emanating from the two catchments further increases towards the end of the 21(st) century, reaching between 34% and 37% for the Ganges and between 52% and 60% for the Brahmaputra by the 2090s. The variability in these changes across the three climate change simulations is small compared to the changes, suggesting they represent a significant increase. The new data obtained in this study offer the first estimate of whether and how anthropogenic climate change may affect the delivery of fluvial sediment to the GBM delta, informing assessments of the future sustainability and resilience of one of the world's most vulnerable mega-deltas. Specifically, such significant increases in future sediment loads could increase the resilience

  4. Water quality assessment in terms of water quality index (WQI): case study of the Kolong River, Assam, India

    Science.gov (United States)

    Bora, Minakshi; Goswami, Dulal C.

    2016-07-01

    The Kolong River of Nagaon district, Assam has been facing serious degradation leading to its current moribund condition due to a drastic human intervention in the form of an embankment put across it near its take-off point from the Brahmaputra River in the year 1964. The blockage of the river flow was adopted as a flood control measure to protect its riparian areas, especially the Nagaon town, from flood hazard. The river, once a blooming distributary of the mighty Brahmaputra, had high navigability and rich riparian biodiversity with a well established agriculturally productive watershed. However, the present status of Kolong River is highly wretched as a consequence of the post-dam effects thus leaving it as stagnant pools of polluted water with negligible socio-economic and ecological value. The Central Pollution Control Board, in one of its report has placed the Kolong River among 275 most polluted rivers of India. Thus, this study is conducted to analyze the seasonal water quality status of the Kolong River in terms of water quality index (WQI). The WQI scores shows very poor to unsuitable quality of water samples in almost all the seven sampling sites along the Kolong River. The water quality is found to be most deteriorated during monsoon season with an average WQI value of 122.47 as compared to pre-monsoon and post-monsoon season having average WQI value of 85.73 and 80.75, respectively. Out of the seven sampling sites, Hatimura site (S1) and Nagaon Town site (S4) are observed to be the most polluted sites.

  5. Documenting spatial diversity and complexity in a large tropical river system: implications for river health and management

    Science.gov (United States)

    Sinha, R.; Mohanta, H.; Tandon, S. K.

    2014-12-01

    The Ganga River system in India is a large, complex system consisting of several long tributaries, some >1000 km, from two distinct hinterlands - the Himalayas to the north and the cratons to the south. Traversing through a diverse climatic regime across the Plain and through precipitation zones ranging from 600 mm/year near Delhi to 1200 mm/year in the eastern plains, the Ganga River system has formed very diverse landform assemblages in its major domains that include a) hinterlands, b) northern Plain, c) southern Plain, d) main valley system, e) interfluve systems, and f) major tributaries. Using satellite images, mapping of the Ganga River channel belt and its active floodplain from Gangotri (source) to Farakka (upstream of its confluence with the Brahmaputra) has brought out extreme diversity in channel form, active floodplain and valley margin characteristics, and reach-scale fluvial processes. Following a modified River Style Framework, we have recognized a total of 10 different river styles for the trunk river from Gangotri to Farakka based on a) landscape setting, b) channel and active floodplain properties, and c) channel planform parameters. The mountainous stretch is characterized by steep valleys and bedrock channels, and is dominated by large-scale sediment production and transport through hill slope processes. The alluvial part of the river is characterized by 8 different styles of varying reach lengths (60-300 km) many of which show sharp transitions in landscape setting e.g. from piedmont to valley-interfluve and from alluvial to craton margin. Each river style in the alluvial reaches has a distinctive set of morphological parameters primarily driven by the dominant fluvial process operating in that stretch such as channel instability and river dynamics, channel incision or aggradation and frequent flooding. Our study has provided a physical template for characterizing the complexity of a large river system and for reach-scale geomorphic assessment

  6. Yarlung Tsangpo to Brahmaputra

    Institute of Scientific and Technical Information of China (English)

    AMITBARUAH

    2004-01-01

    At the airport we were greeted by a giant hoarding put up by a Canton construction company that has arrived to take up work in the Tibet Autonomous Region. Chinese leaders have been urging the more prosperous Chinese provinces and companies to take their capital, equipment and skills to Tibet. Several have taken up the invitation.

  7. Application of current and future satellite missions to hydrologic prediction in transboundary rivers

    Science.gov (United States)

    Biancamaria, S.; Clark, E.; Lettenmaier, D. P.

    2010-12-01

    More than 256 major global river basins, which cover about 45% of the continental land surface, are shared among two or more countries. The flow of such a large part of the global runoff across international boundaries has led to tension in many cases between upstream and downstream riparian countries. Among many examples, this is the case of the Ganges and the Brahmaputra Rivers, which cross the boundary between India and Bangladesh. Hydrological data (river discharge, reservoir storage) are viewed as sensitive by India (the upstream country) and are therefore not shared with Bangladesh, which can only monitor river discharge and water depth at the international border crossing. These measurements only allow forecasting of floods in the interior and southern portions of the country two to three days in advance. These forecasts are not long enough either for agricultural water management purposes (for which knowledge of upstream reservoir storage is essential) or for disaster preparedness purposes. Satellite observations of river spatial extent, surface slope, reservoir area and surface elevation have the potential to make tremendous changes in management of water within the basins. In this study, we examine the use of currently available satellite measurements (in India) and in-situ measurements in Bangladesh to increase forecast lead time in the Ganges and Brahmaputra Rivers. Using nadir altimeters, we find that it is possible to forecast the discharge of the Ganges River at the Bangladesh border with lead time 3 days and mean absolute error of around 25%. On the Ganges River, 2-day forecasts are possible with a mean absolute error of around 20%. When combined with optical/infra-red MODIS images, it is possible to map water elevations along the river and its floodplain upstream of the boundary, and to compute water storage. However, the high frequency of clouds in this region results in relatively large errors in the water mask. Due to the nadir altimeter

  8. Natural and anthropogenic factors controlling the dissolved organic carbon concentrations and fluxes in a large tropical river, India.

    Science.gov (United States)

    Balakrishna, K; Kumar, Itta Arun; Srinikethan, G; Mugeraya, Gopal

    2006-11-01

    Carbon studies in tropical rivers have gained significance since it was realized that a significant chunk of anthropogenic CO(2) emitted into the atmosphere returns to the biosphere, that is eventually transported by the river and locked up in coastal sediments for a few thousand years. Carbon studies are also significant because dissolved organic carbon (DOC) is known to complex the toxic trace metals in the river and carry them in the dissolved form. For the first time, this work has made an attempt to study the variations in DOC concentrations in space and time for a period of 19 months, and estimate their fluxes in the largest peninsular Indian river, the Godavari at Rajahmundry. Anthropogenic influence on DOC concentrations possibly from the number of bathing ghats along the banks and domestic sewage discharge into the river are evident during the pre-monsoon of 2004 and 2005. The rise in DOC concentrations at the onset of monsoon could be due to the contributions from flood plains and soils from the river catchment. Spatial variations highlighted that the DOC concentrations in the river are affected more by the anthropogenic discharges in the downstream than in the upstream. The discharge weighted DOC concentrations in the Godavari river is 3-12 times lower than Ganga-Brahmaputra, Indus and major Chinese rivers. The total carbon fluxes from the Godavari into the Bay of Bengal is insignificant (0.5%) compared to the total carbon discharges by major rivers of the world into oceans. PMID:16738757

  9. Faunal diversity of Cladocera (Crustacea: Branchiopoda in wetlands of Majuli (the largest river island, Assam, northeast India

    Directory of Open Access Journals (Sweden)

    Sharma, B. K.

    2014-06-01

    Full Text Available Our collections from the wetlands of Majuli, the largest river island of the world and a unique fluvial landform of the Brahmaputra river basin of northeast India, reveal 55 Cladocera species belonging to 36 genera. These represent ~46.0% and ~79.0% of the freshwater species and genera of the taxon known from India, respectively. The Indo-Chinese Alona kotovi is new record from India and the Indo-Chinese Chydorus angustirostris is new to northeast India. The Australasian Disperalona caudata, the Indo-Chinese Alona cheni, and the Oriental Celsinotum macronyx and Kurzia (Rostrokurzia brevilabris are other biogeographically notable elements while several species are of regional interest. The speciose and diverse Cladocera reflect habitat diversity and environmental heterogeneity of the sampled ecosystems. The fauna records rich diversity of the littoral-periphytonic taxa in general and the Chydoridae in particular. Majuli Cladocera is characterized by lack of Leydigiopsis, Daphnia spp. and Acroperus harpae; fewer Diaphanosoma spp., and uncommon occurrence of the Bosminidae and Moinidae as compared with our samples elsewhere from the floodplains of the Brahmaputra basin.

  10. Extreme Erosion of the Eastern Himalayan Syntaxis Traced by Isotopic Compositions of River and Bengal Fan Sediments

    Science.gov (United States)

    France-Lanord, C.; Galy, V.; Pik, R.; Singh, S. K.

    2006-12-01

    Sediments of the Brahmaputra basin were collected in Assam and Bangladesh including the Siang-Tsangpo that drains the Namche Barwa syntaxis. Chemistry, and Sr and Nd isotopic compositions trace sediment provenance and erosion distribution in eastern Himalaya. Overall sediments display a large range of 87Sr/86Sr (0.705 to 0.825) and ɛNd (-20.5 to -6.9) (Singh et al. 2001). Nevertheless, sediments of the Siang and along course of the Brahmaputra show almost constant isotopic signatures. Mass balance calculations based on these data along with data available for the Tsangpo in Tibet and in Namche Barwa region show that the basin is marked with differential erosion. About half of the sediments is derived from the syntaxis, which is only 20% of the mountainous area. Zircon-He ages from the Brahmaputra in Bangladesh range from 0.4 to 77 Ma. 40% of the zircon have ages between 0.4 and 1 Ma defining a distribution peak centred at 0.5 Ma. These young ages correspond to extreme denudation rates of 5 to 7 mm/yr. Dispersed ages from 12 to 77 Ma do not define any disctinct group and the remaining 40% of the zircons have ages between 2.5 and 7 Ma, which correspond to the pool of ages recorded by on other Himalayan rivers. The Namche Barwa syntaxis shows the same type of very young zircon ages as observed in the Siang (Stewart et al., 2004). The intense erosion of the eastern syntaxis is likely sustained by the high incision potential of the Tsangpo river due to its very high water discharge prior to the Syntaxis. Sr-Nd isotopic compositions of the Brahmaputra are different from those of the Himalayan tributaries and of the Ganga due to the contribution of the Calc-alkaline formations of the Transhimalaya. This contribution is also traced on modern sediments of the delta as well as in upper Bengal fan aged between 30 and 20 000 years and suggest a rather steady erosion regime since the LGM. On a longer time scale, Mio-Pliocene sediments from the middle Bengal Fan (DSDP Site 218

  11. Hydrologic Visualization of Glacier-Driven Watersheds to Enhance Education Exchange Between Students from the US and Ganges-Brahmaputra Delta on Freshwater Sustainability

    Science.gov (United States)

    Hossain, F.

    2014-12-01

    It has been argued and demonstrated in the past that STEM outreach in the field of hydrology is effective only when it is contextualized using an actual problem that students can visualize in 'their backyard.' The Puyallup watershed, which is in the "backyard" of University of Washington (UW) and the Ganges Brahmaputra (GB) Delta (which UW Department of Civil Engineering has institutional access through an MOU with Institute of Water Modeling-IWM, Bangladesh and International Center for Integrated Mountain Development-ICIMOD, Nepal) provide an ideal opportunity to build a unique education program for US and South Asian students on global freshwater sustainability. Using a rich set of geospatial data layers, dynamic hydrologic datasets and a user-driven visualization platform called Hydro-VIZ, we present a plan on how exchange students can witness the differences in human-nature coupling of each region and share notes on the future of freshwater supply for densely-populated deltas. We discuss the development of a set of place-based learning curricular material built around two contrasting regions and the HydroVIZ platform with functionality to explore the human coupling of water sustainability.

  12. River engineering

    NARCIS (Netherlands)

    De Vries, M.

    1993-01-01

    One dimension models - basic eauations, analytical models, numberical models. One dimensional models -suspended load, roughness and resistance of river beds. Solving river problems - tools, flood mitigation, bank protection.

  13. High gene flow and genetic diversity in three economically important Zanthoxylum Spp. of Upper Brahmaputra Valley Zone of NE India using molecular markers.

    Science.gov (United States)

    Medhi, K; Sarmah, D K; Deka, M; Bhau, B S

    2014-12-01

    The genetic diversity in Zanthoxylum species viz.  Zanthoxylum nitidum, Zanthoxylum oxyphyllum and Zanthoxylum rhesta collected from the Upper Brahmaputra Valley Zone of Assam (NE India) was amplified using 13 random amplified polymorphic DNA (RAPD) markers and 9 inter-simple sequence repeat (ISSR) markers. RAPD markers were able to detect 81.82% polymorphism whereas ISSR detected 98.02% polymorphism. The genetic similarities were analyzed from the dendrogram constructed by RAPD and ISSR fingerprinting methods which divided the 3 species of Zanthoxylum into 3 clear different clusters. The principle component analysis (PCA) was carried out to confirm the clustering pattern of RAPD and ISSR analysis. Analysis of molecular variance (AMOVA) revealed the presence of significant variability between different Zanthoxylum species and within the species by both RAPD and ISSR markers. Z. nitidum was found to be sharing a high degree of variation with the other two Zanthoxylum species under study. The Nei's gene diversity (h), Shannon's information index (I), observed number of alleles (na) and effective number of alleles (ne) were also found to be higher in ISSR markers (0.3526, 0.5230, 1.9802 and 1.6145) than in RAPD markers (0.3144, 0.4610, 1.8182 and 1.5571). The values for total genotype diversity for among population (HT), within population diversity (Hs) and gene flow (Nm) were more in ISSR (0.3491, 0.2644 and 1.5610) than RAPD (0.3128, 0.2264 and 1.3087) but the mean coefficient of gene differentiation (GST) was more in RAPD (0.2764) than ISSR (0.2426). A comparison of this two finger printing methods was done by calculating MR, EMI and MI. The correlation coefficient between data matrices of RAPD and ISSR based on Mantel test was found to be significant (r = 0.65612). PMID:25606454

  14. High gene flow and genetic diversity in three economically important Zanthoxylum Spp. of Upper Brahmaputra Valley Zone of NE India using molecular markers

    Directory of Open Access Journals (Sweden)

    K. Medhi

    2014-12-01

    Full Text Available The genetic diversity in Zanthoxylum species viz. Zanthoxylum nitidum, Zanthoxylum oxyphyllum and Zanthoxylum rhesta collected from the Upper Brahmaputra Valley Zone of Assam (NE India was amplified using 13 random amplified polymorphic DNA (RAPD markers and 9 inter-simple sequence repeat (ISSR markers. RAPD markers were able to detect 81.82% polymorphism whereas ISSR detected 98.02% polymorphism. The genetic similarities were analyzed from the dendrogram constructed by RAPD and ISSR fingerprinting methods which divided the 3 species of Zanthoxylum into 3 clear different clusters. The principle component analysis (PCA was carried out to confirm the clustering pattern of RAPD and ISSR analysis. Analysis of molecular variance (AMOVA revealed the presence of significant variability between different Zanthoxylum species and within the species by both RAPD and ISSR markers. Z. nitidum was found to be sharing a high degree of variation with the other two Zanthoxylum species under study. The Nei's gene diversity (h, Shannon's information index (I, observed number of alleles (na and effective number of alleles (ne were also found to be higher in ISSR markers (0.3526, 0.5230, 1.9802 and 1.6145 than in RAPD markers (0.3144, 0.4610, 1.8182 and 1.5571. The values for total genotype diversity for among population (HT, within population diversity (Hs and gene flow (Nm were more in ISSR (0.3491, 0.2644 and 1.5610 than RAPD (0.3128, 0.2264 and 1.3087 but the mean coefficient of gene differentiation (GST was more in RAPD (0.2764 than ISSR (0.2426. A comparison of this two finger printing methods was done by calculating MR, EMI and MI. The correlation coefficient between data matrices of RAPD and ISSR based on Mantel test was found to be significant (r = 0.65612.

  15. A review of arsenic and its impacts in groundwater of the Ganges-Brahmaputra-Meghna delta, Bangladesh.

    Science.gov (United States)

    Edmunds, W M; Ahmed, K M; Whitehead, P G

    2015-06-01

    Arsenic in drinking water is the single most important environmental issue facing Bangladesh; between 35 and 77 million of its 156 million inhabitants are considered to be at risk from drinking As-contaminated water. This dominates the list of stress factors affecting health, livelihoods and the ecosystem of the delta region. There is a vast literature on the subject so this review provides a filter of the more important information available on the topic. The arsenic problem arises from the move in the 1980s and 1990s by international agencies to construct tube wells as a source of water free of pathogens, groundwater usually considered a safe source. Since arsenic was not measured during routine chemical analysis and also is difficult to measure at low concentrations it was not until the late 1990s that the widespread natural anomaly of high arsenic was discovered and confirmed. The problem was exacerbated by the fact that the medical evidence of arsenicosis only appears slowly. The problem arises in delta regions because of the young age of the sediments deposited by the GBM river system. The sediments contain minerals such as biotite which undergo slow "diagenetic" reactions as the sediments become compacted, and which, under the reducing conditions of the groundwater, release in the form of toxic As(3+). The problem is restricted to sediments of Holocene age and groundwater of a certain depth (mainly 30-150 m), coinciding with the optimum well depth. The problem is most serious in a belt across southern Bangladesh, but within 50 m of the coast the problem is only minor because of use of deep groundwater; salinity in shallow groundwater here is the main issue for drinking water. The Government of Bangladesh adopted a National Arsenic Policy and Mitigation Action Plan in 2004 for providing arsenic safe water to all the exposed population, to provide medical care for those who have visible symptoms of arsenicosis. There is as yet no national monitoring program in

  16. Understanding the Value of Satellite Altimetry for Monitoring Water Level Dynamics of Large Rivers in Bangladesh Delta

    Science.gov (United States)

    Hossain, F.; Akbor, S.; Sustainability, Satellites, Water; Environment (Saswe) Research Group

    2010-12-01

    Although transboundary river flow accounts for more than 40% of global surface flow across 145 nations (many of them water-stressed and conflict-prone), most of this flow is difficult to monitor in developing nations at operational timescales. For Bangladesh, this situation is particularly acute because it comprises only 7% of the entire Ganges-Brahmaputra-Meghna basin and is located at the downstream end of the basin. Thus more than 90% of the water is generated in upstream nations and yet this information is hard to obtain in Bangladesh due to lack of transboundary instrumentation or international treaties. This work therefore investigates the value of satellite radar altimetry in detecting the water level changes for large rivers in the Bangladesh Delta. It is founded on the hypothesis that a satellite altimeter can detect water level to the same accuracy for both inside and outside of Bangladesh. First, the river hydraulic model called HEC-RAS (Hydrologic Engineering Center, River Analysis System) is set up and calibrated over Bangladesh using a comprehensive database on in-situ river bathymetry and observed water level records. Next, the calibrated HEC-RAS model is provided boundary flow conditions upstream and downstream of the model domain. At the upstream end where the Ganges, Brahmaputra and Meghan enter Bangladesh, high resolution flow data modeled from a well calibrated hydrologic model called MIKE BASIN is provided as input. The observed tidal flow records of the Meghna estuary near the Bay of Bengal are used as the downstream boundary conditions. HEC-RAS is then used to simulate daily water level data for the period of 2003-2005 for major rivers of Bangladesh. These water level simulations are directly compared with altimeter estimates of water level from the ENVISAT mission. Accuracy of ENVISAT data is characterized as a function of season, flow regime and river type. The important question that this study aims to answer is, “To what extent can

  17. New insights on the subsidence of the Ganges-Brahmaputra Delta Plain by using 2D multichannel seismic data, gravity and flexural modeling, BanglaPIRE Project

    Science.gov (United States)

    Grall, C.; Pickering, J.; Steckler, M. S.; Spiess, V.; Seeber, L.; Paola, C.; Goodbred, S. L., Jr.; Palamenghi, L.; Schwenk, T.

    2015-12-01

    Deltas can subside very fast, yet many deltas remain emergent over geologic time. A large sediment input is often enough to compensate for subsidence and rising sea level to keep many deltas at sea level. This implies a balance between subsidence and sedimentation, both of which may, however, be controlled by independent factors such as sediment supply, tectonic loads and sea-level change. We here examine the subsidence of the Ganges-Brahmaputra Delta (GBD). Located in the NE boundary of the Indian-Eurasian collision zone, the GBD is surrounded by active uplifts (Indo-Burma Fold Belt and the Shillong Massif). The pattern of subsidence from these tectonic loads can strongly vary depending on both loads and lithospheric flexural rigidity, both of which can vary in space and time. Sediment cover changes both the lithostatic pressure and the thermal properties and thus the rigidity of the lithosphere. While sediments are deposited cold, they also insulate the lithosphere, acting as a thermal blanket to increase lower crustal temperatures. These effects are a function of sedimentation rates and may be more important where the lithosphere is thin. At the massive GBD the impact of sedimentation should be considered for properly constraining flexural subsidence. The flexural rigidity of the lithosphere is here modeled by using a yield-stress envelope based on a thermomechanic model that includes geothermal changes associated with sedimentation. Models are constrained by using two different data sets, multichannel seismic data correlated to borehole stratigraphy, and gravity data. This approach allows us to determine the Holocene regional distribution of subsidence from the Hinge Zone to the Bengal Fan and the mass-anomalies associated with the flexural loading. Different end-member scenarios are explored for reproducing the observed land tilting and gravity anomalies. For all scenarios considered, data can be reproduced only if we consider an extremely weak lithosphere and

  18. Modelling the increased frequency of extreme sea levels in the Ganges-Brahmaputra-Meghna delta due to sea level rise and other effects of climate change.

    Science.gov (United States)

    Kay, S; Caesar, J; Wolf, J; Bricheno, L; Nicholls, R J; Saiful Islam, A K M; Haque, A; Pardaens, A; Lowe, J A

    2015-07-01

    Coastal flooding due to storm surge and high tides is a serious risk for inhabitants of the Ganges-Brahmaputra-Meghna (GBM) delta, as much of the land is close to sea level. Climate change could lead to large areas of land being subject to increased flooding, salinization and ultimate abandonment in West Bengal, India, and Bangladesh. IPCC 5th assessment modelling of sea level rise and estimates of subsidence rates from the EU IMPACT2C project suggest that sea level in the GBM delta region may rise by 0.63 to 0.88 m by 2090, with some studies suggesting this could be up to 0.5 m higher if potential substantial melting of the West Antarctic ice sheet is included. These sea level rise scenarios lead to increased frequency of high water coastal events. Any effect of climate change on the frequency and severity of storms can also have an effect on extreme sea levels. A shelf-sea model of the Bay of Bengal has been used to investigate how the combined effect of sea level rise and changes in other environmental conditions under climate change may alter the frequency of extreme sea level events for the period 1971 to 2099. The model was forced using atmospheric and oceanic boundary conditions derived from climate model projections and the future scenario increase in sea level was applied at its ocean boundary. The model results show an increased likelihood of extreme sea level events through the 21st century, with the frequency of events increasing greatly in the second half of the century: water levels that occurred at decadal time intervals under present-day model conditions occurred in most years by the middle of the 21st century and 3-15 times per year by 2100. The heights of the most extreme events tend to increase more in the first half of the century than the second. The modelled scenarios provide a case study of how sea level rise and other effects of climate change may combine to produce a greatly increased threat to life and property in the GBM delta by the end

  19. Time-scales of erosion and weathering processes in the Himalayan river system: Element and isotope approach using the U-series

    International Nuclear Information System (INIS)

    The time-scales of erosion and weathering processes are key parameters which need to be determined to understand the response of the reliefs to external forcing like tectonics, climate and human activities. They were recovered by using U-series nuclides analyzed in sediments and suspended materials carried by the Himalayan rivers of the Ganges and Brahmaputra basins. In the Ganges basin, the time-scales of weathering determined from the study of coarse sediments carried by the Kali Gandaki range from several ky, where the uplift is located, to 350 ky. Such values indicate that the bed-rocks are in situ weathered for a long period before the weathering residual products get transported in the rivers as coarse sediments. At the outlet of the high range, these sediments are carried by the tributaries of the Ganges, the Gandak and Ghaghara, during a transfer period of about 100 ka. The study of the sediments at the outlet of the Brahmaputra tributaries allows to propose time-scales of weathering ranging from 110 to 270 ky. Such long periods confirm that during their transfer in the plains, the sediments are temporarily trapped at several places in the basins. In the Ganges and Brahmaputra rivers, the time-scales of sedimentary transfer are 575 and 160 ky, respectively. These values, which are of the same order as their response times, are much longer than the timescales of the Quaternary climate oscillations. It confirms the buffering action of the asiatic alluvial plains for the high-frequency sediment flux variations in response to external forcing in the chain. The study of suspended materials suggests that their chemical compositions result from the mixing of coarse river sediments with fine particles from various locations in the basin which are affected by vegetation recycling. By contrast to coarse sediments, the time-scales of transfer for the suspended materials are fast, e.g. a few ky, pointing the potential of U-series nuclides to assess particle transport

  20. Estimation of river depth from remotely sensed hydraulic relationships

    Science.gov (United States)

    Mersel, Matthew K.; Smith, Laurence C.; Andreadis, Konstantinos M.; Durand, Michael T.

    2013-06-01

    The Surface Water and Ocean Topography (SWOT) radar interferometer satellite mission will provide unprecedented global measurements of water surface elevation (h) for inland water bodies. However, like most remote sensing technologies SWOT will not observe river channel bathymetry below the lowest observed water surface, thus limiting its value for estimating river depth and/or discharge. This study explores if remotely sensed observations of river inundation width and h alone, when accumulated over time, may be used to estimate this unmeasurable flow depth. To test this possibility, synthetic values of h and either cross-sectional flow width (w) or effective width (We, inundation area divided by reach length) are extracted from 1495 previously surveyed channel cross-sections for the Upper Mississippi, Illinois, Rio Grande, and Ganges-Brahmaputra river systems, and from 62 km of continuously acquired sonar data for the Upper Mississippi. Two proposed methods (called "Linear" and "Slope-Break") are tested that seek to identify a small subset of geomorphically "optimal" locations where w or We covary strongly with h, such that they may be usefully extrapolated to estimate mean cross-sectional flow depth (d). While the simplest Linear Method is found to have considerable uncertainty, the Slope-Break Method, identifying locations where two distinct hydraulic relationships are identified (one for moderate to high flows and one for low flows), holds promise. Useful slope breaks were discovered in all four river systems, ranging from 6 (0.04%) to 242 (16%) of the 1495 studied cross-sections, assuming channel bathymetric exposures ranging from 20% to 95% of bankfull conditions, respectively. For all four rivers, the derived depth estimates from the Slope-Break Method have root mean squared errors (RMSEs) of discharge records and HEC-RAS hydraulic modeling, the Upper Mississippi and Rio Grande rivers experience adequate channel exposures at least ˜60% and ˜42% of the time

  1. Seasonality of the hydrological cycle in major South and Southeast Asian River Basins as simulated by PCMDI/CMIP3 experiments

    CERN Document Server

    Hasson, Shabeh ul; Pascale, Salvatore; Böhner, Juergen

    2013-01-01

    In this study, we investigate how PCMDI/CMIP3 general circulation models (GCMs) represent the seasonal properties of the hydrological cycle in four major South and Southeast Asian river basins (Indus, Ganges, and Brahmaputra and Mekong). First, we examine the skill of GCMs by analysing their simulations for the XX century climate (1961-2000) under present-day forcing, and then we analyse the projected changes for the corresponding XXI and XXII century climates under SRESA1B scenario. CMIP3 GCMs show a varying degree of skill in simulating the basic characteristics of the monsoonal precipitation regimes of the Ganges, Brahmaputra and Mekong basins, while the representation of the hydrological cycle over the Indus basin is poor in most cases, with few GCMs not capturing the monsoon signal at all. Although the models' outputs feature a remarkable spread for the monsoonal precipitations, a satisfactory representation of the western mid-latitude precipitation regime is instead observed. Similarly, most of the mode...

  2. Hydrological Mechanism for Arsenic Deposits in Meghna River Hyporheic Zone Sediments

    Science.gov (United States)

    Knappett, Peter; Datta, Saugata; Dimova, Natasha; Myers, Kimberly; Hossain, Abrar; Berube, Michelle; Shuai, Pin; Rhodes, Kimberly; Jewell, Katrina; Lipsi, Mehtaz; Hossain, Saddam; Hosain, Alamgir; Peterson, Jacqeline; Ahmed, Kazi

    2016-04-01

    Heavy metal deposits along the interface between aquifers and rivers have been discovered in diverse settings around the world. This so-called "Iron Curtain" is thought to be caused by groundwater flow towards the riverbank. To our knowledge the hydrology of this process hasn't been studied along a tidally influenced, completely fresh river-aquifer system. The Meghna River within the Ganges-Brahmaputra-Meghna Delta (GBMD) experiences tidal fluctuations that propagate over 400 km upstream, from the Bay of Bengal to Sylhet City. River and aquifer water levels also fluctuate seasonally by as much as 4 m as the region receives most of its ~ 2 m of rainfall from June through September. We studied a 10 km reach of the Meghna River 200 km north of the coast where the eastern side of the river is strongly gaining for most of the year. In contrast, the river both gains and loses water to shallow aquifers on the western side. High solid-phase iron (Fe) and arsenic (As) concentrations were previously observed in Meghna riverbank sediments. To test the hypothesis that groundwater discharge is responsible for depositing Fe and As in the riverbank we mapped major and trace element distribution at ~ 100 m spacing on both the east and west side of the river using X-ray fluorescence. The distribution of solid-phase Fe and As were compared to hydraulic gradients, hydraulic conductivity, and ambient liquid-phase concentrations in the riverbank aquifer. Hydraulic gradients were measured with transects of monitoring wells at three locations, and the 30 m deep shallow aquifer was mapped 500 m north and south parallel and orthogonal to each river bank using Electrical Resistivity Tomography (ERT). Resistivity, borehole logging, and slug tests indicate the aquifer dimensions and properties are remarkably consistent at the 3 locations on both sides of the river. Groundwater discharge to the river obtained from Darcy's Law and two independent methods indicate the high As deposits can

  3. Glyptothorax mibangi, a new species of catfish (Teleostei: Sisoridae) from the Tisa River, Arunachal Pradesh, northeast India.

    Science.gov (United States)

    Darshan, Achom; Dutta, Rashmi; Kachari, Akash; Gogoi, Budhin; Das, Debangshu Narayan

    2015-01-01

    Glyptothorax mibangi, a new sisorid catfish, is described from the Tisa River of Arunachal Pradesh, India. The new species can be distinguished from its congeners in the Ganga-Brahmaputra and Barak-Surma-Meghna basins by the following combination of characters: an obtuse leaf-shaped thoracic adhesive apparatus with a spindle-shaped median depression, skin ridges present over the entire apparatus including the depressed region; ventral surface of pectoral spine and first pelvic-fin ray non-plaited; slender body with depth of 10.4-13.5% SL; caudal peduncle shallow with depth 6.8-8.3% SL; snout long with length 52.9-58.6% HL; and 2+7 gill rakers on the first branchial arch.

  4. Glyptothorax mibangi, a new species of catfish (Teleostei: Sisoridae) from the Tisa River, Arunachal Pradesh, northeast India.

    Science.gov (United States)

    Darshan, Achom; Dutta, Rashmi; Kachari, Akash; Gogoi, Budhin; Das, Debangshu Narayan

    2015-01-01

    Glyptothorax mibangi, a new sisorid catfish, is described from the Tisa River of Arunachal Pradesh, India. The new species can be distinguished from its congeners in the Ganga-Brahmaputra and Barak-Surma-Meghna basins by the following combination of characters: an obtuse leaf-shaped thoracic adhesive apparatus with a spindle-shaped median depression, skin ridges present over the entire apparatus including the depressed region; ventral surface of pectoral spine and first pelvic-fin ray non-plaited; slender body with depth of 10.4-13.5% SL; caudal peduncle shallow with depth 6.8-8.3% SL; snout long with length 52.9-58.6% HL; and 2+7 gill rakers on the first branchial arch. PMID:26249379

  5. Spatiotemporal interpolation of discharge across a river network by using synthetic SWOT satellite data

    Science.gov (United States)

    Paiva, Rodrigo C. D.; Durand, Michael T.; Hossain, Faisal

    2015-01-01

    Recent efforts have sought to estimate river discharge and other surface water-related quantities using spaceborne sensors, with better spatial coverage but worse temporal sampling as compared with in situ measurements. The Surface Water and Ocean Topography (SWOT) mission will provide river discharge estimates globally from space. However, questions on how to optimally use the spatially distributed but asynchronous satellite observations to generate continuous fields still exist. This paper presents a statistical model (River Kriging-RK), for estimating discharge time series in a river network in the context of the SWOT mission. RK uses discharge estimates at different locations and times to produce a continuous field using spatiotemporal kriging. A key component of RK is the space-time river discharge covariance, which was derived analytically from the diffusive wave approximation of Saint Venant's equations. The RK covariance also accounts for the loss of correlation at confluences. The model performed well in a case study on Ganges-Brahmaputra-Meghna (GBM) River system in Bangladesh using synthetic SWOT observations. The correlation model reproduced empirically derived values. RK (R2=0.83) outperformed other kriging-based methods (R2=0.80), as well as a simple time series linear interpolation (R2=0.72). RK was used to combine discharge from SWOT and in situ observations, improving estimates when the latter is included (R2=0.91). The proposed statistical concepts may eventually provide a feasible framework to estimate continuous discharge time series across a river network based on SWOT data, other altimetry missions, and/or in situ data.

  6. The role of mega dams in reducing sediment fluxes: A case study of large Asian rivers

    Science.gov (United States)

    Gupta, Harish; Kao, Shuh-Ji; Dai, Minhan

    2012-09-01

    SummaryIn order to sustain the ever growing population and to meet water and energy requirements of the rapidly growing economies, most of the large rivers draining through East, Southern and Southeast (ESSE) Asian region have been regulated all along their courses, over the past few decades. For instance, ESSE Asian countries (China, Taiwan, Vietnam, Myanmar, Thailand, India, Pakistan and Bangladesh) host about 250 mega dams and several tens of thousands of large and small reservoirs. The present study provides a revised estimate on annual suspended sediment fluxes of the large rivers draining through ESSE region, including the latest data of the Indian peninsula rivers. In the last 50 years, the combined annual sediment flux of the large Chinese rivers has been reduced from 1800 million tons (Mt) to about 370 Mt. We estimate that at present the Indian peninsular rivers collectively transport about 83 Mt of sediment annually. The Ganga-Brahmaputra and the Indus, contribute 850 and 13 Mt of sediments, respectively to the oceans. Our revised estimates suggest that at present the large rivers of ESSE region, collectively delivering ∼2150 Mt of sediment annually to the oceans. We show that at decadal scale, decline in sediment fluxes of the large Asian rivers are proportional to the number of mega dams present in the respective catchments. We also demonstrate that storage of sediment-laden water of major flood events (major-event), led to huge sediment trapping behind mega dams. Thus, ongoing and planned dam constructions activities across ESSE Asia may further reduce the annual sediment fluxes.

  7. The assemblage characteristics of benthic macroinvertebrates in the Yalutsangpo River, the highest major river in the world

    Science.gov (United States)

    Xu, Mengzhen; Wang, Zhaoyin; Pan, Baozhu; Yu, Guoan

    2014-09-01

    Aquatic ecosystems of highland rivers are different from those of low altitude rivers because of the specific topography and environmental parameters associated with high altitudes. Yalutsangpo, the upper course of the Brahmaputra River, is the highest major river in the world, flowing from west to east across Tibet, China and pouring into India. Macroinvertebrates were sampled from Yalutsangpo and its tributaries, the Lhasa, Niyang, and Parlong Tsangpo Rivers, from October 2009 to June 2010, to study characters of the highland aquatic ecosystem. Altogether, 110 macroinvertebrate taxa belonging to 57 families and 102 genera were identified from the basin. The biodiversity and composition of macroinvertebrate assemblages were strongly affected by altitude gradients. Local diversity represented by taxa richness and the improved Shannon-Wiener index were high at altitudes of 3,300-3,700 m, among which suitability of habitat was higher due to the better integrated environmental conditions of water temperature, dissolved oxygen, and aquatic vegetation, etc. Macroinvertebrates were grouped into shredders, scrapers, predators, collector-filterers, and collector-gatherers according to their feeding behaviors. It was found that the distributions of the functional feeding groups varied with habitat altitudes. Shredders were present at altitudes of 2,900-4,400 m, while scrapers mainly inhabited altitudes of 3,500-4,500 m, and collector-filterers preferred 3,500-4,000 m. Even though the local taxa richness was not high at each site, the taxonomic composition and density of the assemblages varied greatly among the different sites, resulting in much higher regional diversity compared to the lowland river with similar flow and substrate conditions. The regional cumulative taxa richness of Yalutsangpo decreased and more families were lost as the altitude increased. However, some families that were newly present as the altitude increased were essential for sustaining the high

  8. On Rivers

    OpenAIRE

    Gleason, Colin Joseph

    2016-01-01

    Despite the importance of rivers to industry, agriculture, the climate system, and global ecosystems, our current knowledge of river discharge (volume of available water per unit time) is surprisingly poor for many regions of the world as political cloistering, aging infrastructure, and rapid human changes limit our ability to understand global surface waters holistically. Closing this knowledge gap is critical for better management of surface water in light of drought and increasing human de...

  9. Habitat fragmentation and species extirpation in freshwater ecosystems; causes of range decline of the Indus river dolphin (Platanista gangetica minor.

    Directory of Open Access Journals (Sweden)

    Gill T Braulik

    Full Text Available Habitat fragmentation of freshwater ecosystems is increasing rapidly, however the understanding of extinction debt and species decline in riverine habitat fragments lags behind that in other ecosystems. The mighty rivers that drain the Himalaya - the Ganges, Brahmaputra, Indus, Mekong and Yangtze - are amongst the world's most biodiverse freshwater ecosystems. Many hundreds of dams have been constructed, are under construction, or are planned on these rivers and large hydrological changes and losses of biodiversity have occurred and are expected to continue. This study examines the causes of range decline of the Indus dolphin, which inhabits one of the world's most modified rivers, to demonstrate how we may expect other vertebrate populations to respond as planned dams and water developments come into operation. The historical range of the Indus dolphin has been fragmented into 17 river sections by diversion dams; dolphin sighting and interview surveys show that river dolphins have been extirpated from ten river sections, they persist in 6, and are of unknown status in one section. Seven potential factors influencing the temporal and spatial pattern of decline were considered in three regression model sets. Low dry-season river discharge, due to water abstraction at irrigation barrages, was the principal factor that explained the dolphin's range decline, influencing 1 the spatial pattern of persistence, 2 the temporal pattern of subpopulation extirpation, and 3 the speed of extirpation after habitat fragmentation. Dolphins were more likely to persist in the core of the former range because water diversions are concentrated near the range periphery. Habitat fragmentation and degradation of the habitat were inextricably intertwined and in combination caused the catastrophic decline of the Indus dolphin.

  10. Sediment characteristics and transportation dynamics of the Ganga River

    Science.gov (United States)

    Singh, Munendra; Singh, Indra Bir; Müller, German

    2007-04-01

    Understanding of river systems that have experienced various forcing mechanisms such as climate, tectonics, sea level fluctuations and their linkages is a major concern for fluvial scientists. The 2525-km-long Ganga River derives its fluvial flux from northern part of the Indian subcontinent and drops in the Ganga-Brahmaputra delta and the Bengal fan regions. This paper presents a study of the Ganga River sediments for their textural properties, grainsize characteristics, and transportation dynamics. A suite of recently deposited sediments (189 bedload samples and 27 suspended load samples) of the river and its tributaries was collected from 63 locations. Dry and wet sieve methods of grainsize analysis were performed and Folk and Ward's parameters were calculated. Transportation dynamics of the sediment load was assessed by means of channel hydrology, flow/sediment rating curves, bedform mechanics, grainsize images, and cumulative curves. Textural properties of the bedload sediments of the Ganga River tributaries originating from the Himalaya orogenic belt, the northern Indian craton and the Ganga alluvial plain regions are characterised by the predominance of fine to very fine sand, medium to fine sand, and very fine sand to clay, respectively. Downstream textural variations in the bedload and suspended load sediments of the Ganga River are, therefore, complex and are strongly influenced by lateral sediment inputs by the tributaries and channel slope. At the base of the Himalaya, a very sharp gravel-sand transition is present in which median grainsize of bedload sediments decreases from over - 0.16 Φ to 2.46 Φ within a distance of 35 km. Downstream decline in mean grainsize of bedload sediments in the upper Ganga River within the alluvial plain can be expressed by an exponential formula as: mean grainsize (in Φ) = 0.0024 × Distance (in kilometres from the Himalayan front) + 1.29. It is a result of selective transport phenomena rather than of abrasion, the

  11. Paleo-Reconstruction of Carbon Cycling in Large-River Delta-Front Estuaries: Use of Molecular Biomarkers

    Science.gov (United States)

    Bianchi, T. S.

    2014-12-01

    The burial of organic carbon (OC) in river deltas and continental margins worldwide account for approximately 90% of the carbon burial in the ocean. In particular, sediments in large-river delta-front estuaries have been shown to be repositories and integrators of land-use change across expansive watersheds that drain the continents to the ocean. Thus, separating natural and human-driven changes in the transport of terrestrial organic carbon (TOC) to ocean is important in understanding the effects of climate change on TOC fluxes. Molecular biomarkers of TOC (e.g., lignin phenols, fatty acids, sterols) in LDE sediments have been used extensively to reconstruct of carbon cycling changes that are reflective of land-use change in the watersheds. However, due to the highly variable hydrologic regimes across continents, continental margins (e.g., active versus passive), and coastal dynamics in LDEs, the fate and transport of these molecular biomarkers varies considerably. Here I will discuss some of the key molecular biomarkers that have been used to date in such historical reconstruction exercises in LDEs (e.g., Mississippi/Atchafalaya, Yangtze, Yellow, Ganges-Brahmaputra, Colville Rivers), and explore how margin-type, residence time of transport, redox, and molecular stability, to name a few, impact the utility of using different biomarkers in paleo-reconstruction studies.

  12. A Consistent Radar Altimetry Dataset for Major World Rivers: Extraction Methods and Preliminary Data Products

    Science.gov (United States)

    Coss, S. P.; Durand, M. T.; Tuozzolo, S.; Yi, Y.; Jia, Y.; Guo, Q.; Shum, C. K.

    2015-12-01

    Our group has made several efforts to develop the systematics for processing multiple satellite mission inland altimetry data with the purpose of creating a pre-SWOT climate data record of world's rivers greater than 900m in width. The project is a component of a NASA MEaSUREs (Making Earth System Data Records for Use in Research Environments) project undertaken by UCLA, Princeton U., NASA/GSFC and Ohio State Univ. The first method developed allows for the identification of measurements that represent the target river through height filtering and is based on USGS flow data from 105 gauges on rivers with watersheds over 20,000 km2. Proximal topographic variations led to some contamination of the radar returns. We were able to identify them using the previously mentioned height filter, and correlated their frequency with near-river topographic indices. Significant efforts have also been made to detect river ice using only radar backscatter. Over 631 Landsat images were processed and given an ice cover designation then compared with measured backscatter profiles; demonstrating that isolating a one- to-one relationship between ice and backscatter will be challenging. An additional focus of the group has been automation of detecting altimeter/river intersections as well as the creation of "virtual stations" or masks for data extraction at those locations. Using RivWidth parameters to generate polygons and a raster proximity based intersection detection methods have both shown promising results for automation of this process. This project will soon be producing validated climate data records in the form of geocentric river height changes, both in terms of scale of the study area and access to previously unmonitored regions. Once established, these methods will also be applicable to the study of future satellite cycles. Preliminary river height change data products have been produced for the Mississippi, St Lawrence, Yukon, Mackenzie, and part of the Ganges-Brahmaputra

  13. Influence of ligands on metal speciation, transport and toxicity in a tropical river during wet (monsoon) period.

    Science.gov (United States)

    Gogoi, Anindita; Tushara Chaminda, G G; An, Alicia K J; Snow, Daniel D; Li, Yusong; Kumar, Manish

    2016-11-01

    Metal speciation and transport are seldom assessed in densely populated Tropical River. An evaluation of the phase distribution for Copper (Cu), Lead (Pb) and Zinc (Zn) along with chemical speciation, variance with different water quality parameters and toxicity were conducted in the Brahmaputra River of India from upstream to downstream during wet (monsoon) periods in July 2014. Results indicated that metal free ions and carbonates were dominant in the inorganic fractions whereas metal concentrations were negligible in the anionic inorganic fractions. Due to high sediment load in the river during monsoon, metals were substantially higher in the particulate fractions than in the aqueous phase. Partition coefficient for Cu (3.1-6.1), Pb (3.4-6.5) and Zn (3.5-6.9), demonstrated strong adsorption of the metals on suspended matter. Q-mode hierarchical cluster analysis (HCA) illustrated groupings mainly governed by quality parameters rather than by the river course. R-mode results imply selectivity of the affinities of metals for different ligands. Health risk index (HRI) values were less than 1 for dissolved metal for Cu, Pb and Zn while it was greater than 1 for total metal for Pb and Cu indicating potential human health risk. The study demonstrated that binding of metals with naturally occurring dissolved organic matter or suspended particulate matter affects metal bioavailability in river during wet periods when sediment load is particularly high. A combination of empirical, computational and statistical relationships between ionic species and fractions of metals provided greater certitude in identifying the resemblance among the different locations of the river. PMID:27544655

  14. Time-scales of erosion and weathering processes in the Himalayan river system: Element and isotope approach using the U-series; Constantes de temps des processus d'erosion et d'alteration dans le systeme himalayen: approche geochimique elementaire et isotopique par les series de l'uranium

    Energy Technology Data Exchange (ETDEWEB)

    Granet, M

    2007-06-15

    The time-scales of erosion and weathering processes are key parameters which need to be determined to understand the response of the reliefs to external forcing like tectonics, climate and human activities. They were recovered by using U-series nuclides analyzed in sediments and suspended materials carried by the Himalayan rivers of the Ganges and Brahmaputra basins. In the Ganges basin, the time-scales of weathering determined from the study of coarse sediments carried by the Kali Gandaki range from several ky, where the uplift is located, to 350 ky. Such values indicate that the bed-rocks are in situ weathered for a long period before the weathering residual products get transported in the rivers as coarse sediments. At the outlet of the high range, these sediments are carried by the tributaries of the Ganges, the Gandak and Ghaghara, during a transfer period of about 100 ka. The study of the sediments at the outlet of the Brahmaputra tributaries allows to propose time-scales of weathering ranging from 110 to 270 ky. Such long periods confirm that during their transfer in the plains, the sediments are temporarily trapped at several places in the basins. In the Ganges and Brahmaputra rivers, the time-scales of sedimentary transfer are 575 and 160 ky, respectively. These values, which are of the same order as their response times, are much longer than the timescales of the Quaternary climate oscillations. It confirms the buffering action of the asiatic alluvial plains for the high-frequency sediment flux variations in response to external forcing in the chain. The study of suspended materials suggests that their chemical compositions result from the mixing of coarse river sediments with fine particles from various locations in the basin which are affected by vegetation recycling. By contrast to coarse sediments, the time-scales of transfer for the suspended materials are fast, e.g. a few ky, pointing the potential of U-series nuclides to assess particle transport

  15. The contribution of sea-level rise to flooding in large river catchments

    Science.gov (United States)

    Thiele-Eich, I.; Hopson, T. M.; Gilleland, E.; Lamarque, J.; Hu, A.; Simmer, C.

    2012-12-01

    Climate change is expected to both impact sea level rise as well as flooding. Our study focuses on the combined effect of climate change on upper catchment precipitation as well as on sea-level rise at the river mouths and the impact this will have on river flooding both at the coast and further upstream. We concentrate on the eight catchments of the Amazonas, Congo, Orinoco, Ganges/Brahmaputra/Meghna, Mississippi, St. Lawrence, Danube and Niger rivers. To assess the impact of climate change, upper catchment precipitation as well as monthly mean thermosteric sea-level rise at the river mouth outflow are taken from the four CCSM4 1° 20th Century ensemble members as well as from six CCSM4 1° ensemble members for the RCP scenarios RCP8.5, 6.0, 4.5 and 2.6. Continuous daily time series for average catchment precipitation and discharge are available for each of the catchments. To arrive at a future discharge time series, we used these observations to develop a simple statistical hydrological model which can be applied to the modelled future upper catchment precipitation values. The analysis of this surrogate discharge time series alone already yields significant changes in flood return levels as well as flood duration. Using the geometry of the river channel, the backwater effect of sea-level rise is incorporated in our analysis of both flood frequencies and magnitudes by calculating the effective additional discharge due to the increase in water level at the river mouth outflow, as well as its tapering impact upstream. By combining these effects, our results focus on the merged impact of changes in extreme precipitation with increases in river height due to sea-level rise at the river mouths. Judging from our preliminary results, the increase in effective discharge due to sea-level rise cannot be neglected when discussing late 21st century flooding in the respective river basins. In particular, we find that especially in countries with low elevation gradient, flood

  16. Simulated long-term changes in river discharge and soil moisture due to global warming

    Science.gov (United States)

    Manabe, S.; Milly, P.C.D.; Wetherald, R.

    2004-01-01

    By use of a coupled ocean atmosphere-land model, this study explores the changes of water availability, as measured by river discharge and soil moisture, that could occur by the middle of the 21st century in response to combined increases of greenhouse gases and sulphate aerosols based upon the "IS92a" scenario. In addition, it presents the simulated change in water availability that might be realized in a few centuries in response to a quadrupling of CO2 concentration in the atmosphere. Averaging the results over extended periods, the radiatively forced changes, which are very similar between the two sets of experiments, were successfully extracted. The analysis indicates that the discharges from Arctic rivers such as the Mackenzie and Ob' increase by up to 20% (of the pre-Industrial Period level) by the middle of the 21st century and by up to 40% or more in a few centuries. In the tropics, the discharges from the Amazonas and Ganga-Brahmaputra rivers increase substantially. However, the percentage changes in runoff from other tropical and many mid-latitude rivers are smaller, with both positive and negative signs. For soil moisture, the results of this study indicate reductions during much of the year in many semiarid regions of the world, such as the southwestern region of North America, the northeastern region of China, the Mediterranean coast of Europe, and the grasslands of Australia and Africa. As a percentage, the reduction is particularly large during the dry season. From middle to high latitudes of the Northern Hemisphere, soil moisture decreases in summer but increases in winter.

  17. Seasonal cycle of Precipitation over Major River Basins in South and Southeast Asia: A Review of the CMIP5 climate models data for present climate and future climate projections

    CERN Document Server

    Hasson, Shabeh ul; Lucarini, Valerio; Böhner, Jürgen

    2015-01-01

    We review the skill of thirty coupled climate models participating in Coupled Model Intercomparison Project 5 in terms of reproducing properties of the seasonal cycle of precipitation over the major river basins of South and Southeast Asia (Indus, Ganges, Brahmaputra and Mekong) for historical period (1961-2000). We also present projected changes by these models by end of century (2061-2100) under extreme scenario RCP8.5. First, we assess their ability to reproduce observed timings of the monsoon onset and the rate of rapid fractional accumulation (RFA slope) - a measure of seasonality within active monsoon period. Secondly, we apply a threshold-independent seasonality index (SI) - a multiplicative measure of precipitation and extent of its concentration relative to the uniform distribution (relative entropy - RE). We apply SI distinctly for monsoonal precipitation regime (MPR), westerly precipitation regime (WPR) and annual precipitation regime. For present climate, neither any single model nor the multi-mod...

  18. Sediment transfer and deposition throughout the Himalayan continental and oceanic basin : constraint from geochemical composition of river sediments

    Science.gov (United States)

    France-Lanord, Christian; Gajurel, Ananta; Galy, Valier; Lavé, Jérôme; Lupker, Maarten; Morin, Guillaume

    2013-04-01

    The Himalayan erosion system presents a highly contrasted transport system with a very steep and relatively short mountainous part and a long and very flat floodplain and deltaic part. Indeed the modest slope and the subsidence in the floodplain tend to favour deposition and it's importance is difficult to assess. Because deposition preferentially involves coarse and quartz rich sediments it tends to fractionate the overall sediment load transported by the rivers [1]. This can be tracked using the evolution of major element concentrations in the sediment tacking into account the potential bias due to chemical erosion. Overall, estimated in the Ganga-Brahmaputra delta, chemical denudation represents less than 10% of the total erosion flux and it is mainly generated from carbonate dissolution. On the silicate side, chemical erosion does not affect the most important major elements and even for a relatively soluble element like Si, it does not exceed 2%. Therefore concentrations of Si, Al, Fe in sediments can be considered as conservative. We present a set of modern river sediment samples from the Himalayan front to the Bangladesh delta and from sediments from the modern and Neogene Bengal fan. Most river sampling were performed during monsoon when rivers are at their high stage. Sampling includes river depth sampling to document river variability due to settling processes in the water column, daily sampling on the Narayani-Gandak river to document seasonal variability. Data show that grain size/mineralogical segregation becomes more pronounced downstream and is clearly dependant on the hydrodynamical conditions [1]. At the Himalayan front, data show that Al/Si ratios vary from 0.29 to 0.20 with minor variation in the water column. Average pebble composition is highly enriched in quartz with a ratio of 0.11. Ganga and Brahmaputra rivers in Bangladesh typically vary from 0.32 at the surface to 0.13 in the bedload. In the Lower Meghna estuary, surface suspension is at 0

  19. How Much Do We Know about the Storage Changes in the Major River Basins of the World? Analysis of Storage Change from GRACE

    Science.gov (United States)

    Velpuri, N. M.; Senay, G. B.; Verdin, J. P.

    2014-12-01

    Change in storage is an important component of water cycle that is often ignored in large-scale hydrologic studies due to limited data and difficulty in measurement. For the first time, this study quantifies and inter-compares storage changes in major river basins of the world. Gravity Recovery and Climate Experiment (GRACE) monthly mass deviation in storage (MDS) data over 2003-2013 is used to compute monthly, annual and long-term change in storage (ΔS) for 51 major river basins of the world (> 200,000 km2). For each river basin, GRACE ΔS is analyzed to understand a) temporal variability in ΔS b) magnitude of ΔS at annual and decadal time scales and c) duration of storage cycle (time taken by a basin in months to return to initial storage condition). This study identified that 11, 33 and 7 out of 51 basins showed high, medium and low month to month variability in storage changes, respectively. Compared to basin precipitation, 48 out of 51 river basins showed storage to be considerable (5 - 35% of basin annual precipitation). Only 3 basins (Irrawaddy, St. Lawrence, and Brahmaputra) showed minimum variability in storage (river basins showed negligible storage changes (river basins. Future study would focus on the analysis of ΔS over large river basins within the United States. Such analysis and estimates of ΔS would help to (i) improve our knowledge of water availability and (ii) meet the goals of the WaterSMART (Sustain and Manage America's Resources for Tomorrow) project.

  20. Remote Sensing of River Delta Inundation: Exploiting the Potential of Coarse Spatial Resolution, Temporally-Dense MODIS Time Series

    Directory of Open Access Journals (Sweden)

    Claudia Kuenzer

    2015-07-01

    Full Text Available River deltas belong to the most densely settled places on earth. Although they only account for 5% of the global land surface, over 550 million people live in deltas. These preferred livelihood locations, which feature flat terrain, fertile alluvial soils, access to fluvial and marine resources, a rich wetland biodiversity and other advantages are, however, threatened by numerous internal and external processes. Socio-economic development, urbanization, climate change induced sea level rise, as well as flood pulse changes due to upstream water diversion all lead to changes in these highly dynamic systems. A thorough understanding of a river delta’s general setting and intra-annual as well as long-term dynamic is therefore crucial for an informed management of natural resources. Here, remote sensing can play a key role in analyzing and monitoring these vast areas at a global scale. The goal of this study is to demonstrate the potential of intra-annual time series analyses at dense temporal, but coarse spatial resolution for inundation characterization in five river deltas located in four different countries. Based on 250 m MODIS reflectance data we analyze inundation dynamics in four densely populated Asian river deltas—namely the Yellow River Delta (China, the Mekong Delta (Vietnam, the Irrawaddy Delta (Myanmar, and the Ganges-Brahmaputra (Bangladesh, India—as well as one very contrasting delta: the nearly uninhabited polar Mackenzie Delta Region in northwestern Canada for the complete time span of one year (2013. A complex processing chain of water surface derivation on a daily basis allows the generation of intra-annual time series, which indicate inundation duration in each of the deltas. Our analyses depict distinct inundation patterns within each of the deltas, which can be attributed to processes such as overland flooding, irrigation agriculture, aquaculture, or snowmelt and thermokarst processes. Clear differences between mid

  1. South Asia river flow projections and their implications for water resources

    Directory of Open Access Journals (Sweden)

    C. Mathison

    2015-06-01

    Full Text Available South Asia is a region with a large and rising population and a high dependance on industries sensitive to water resource such as agriculture. The climate is hugely variable with the region relying on both the Asian Summer Monsoon (ASM and glaciers for its supply of fresh water. In recent years, changes in the ASM, fears over the rapid retreat of glaciers and the increasing demand for water resources for domestic and industrial use, have caused concern over the reliability of water resources both in the present day and future for this region. The climate of South Asia means it is one of the most irrigated agricultural regions in the world, therefore pressures on water resource affecting the availability of water for irrigation could adversely affect crop yields and therefore food production. In this paper we present the first 25 km resolution regional climate projections of river flow for the South Asia region. ERA-Interim, together with two global climate models (GCMs, which represent the present day processes, particularly the monsoon, reasonably well are downscaled using a regional climate model (RCM for the periods; 1990–2006 for ERA-Interim and 1960–2100 for the two GCMs. The RCM river flow is routed using a river-routing model to allow analysis of present day and future river flows through comparison with river gauge observations, where available. In this analysis we compare the river flow rate for 12 gauges selected to represent the largest river basins for this region; Ganges, Indus and Brahmaputra basins and characterize the changing conditions from east to west across the Himalayan arc. Observations of precipitation and runoff in this region have large or unknown uncertainties, are short in length or are outside the simulation period, hindering model development and validation designed to improve understanding of the water cycle for this region. In the absence of robust observations for South Asia, a downscaled ERA-Interim RCM

  2. YELLOWSTONE RIVER WATCH (YRW)

    Science.gov (United States)

    Yellowstone River Watch seeks to expand its monitoring and education efforts throughout the Yellowstone River Basin by actively recruiting and training new teacher members. Yellowstone River Watch also seeks to advance existing school programs by offering quality assurance/quali...

  3. Seasonal cycle of precipitation over major river basins in South and Southeast Asia: A review of the CMIP5 climate models data for present climate and future climate projections

    Science.gov (United States)

    Hasson, Shabeh ul; Pascale, Salvatore; Lucarini, Valerio; Böhner, Jürgen

    2016-11-01

    We review the skill of thirty coupled climate models participating in the Coupled Model Intercomparison Project Phase 5 (CMIP5) in terms of reproducing properties of the seasonal cycle of precipitation over the major river basins of South and Southeast Asia (Indus, Ganges, Brahmaputra and Mekong) for the historical period (1961-2000). We also present how these models represent the impact of climate change by the end of century (2061-2100) under the extreme scenario RCP8.5. First, we assess the models' ability to reproduce the observed timings of the monsoon onset and the rate of rapid fractional accumulation (RFA) slope - a measure of seasonality within the active monsoon period. Secondly, we apply a threshold-independent seasonality index (SI) - a multiplicative measure of precipitation (P) and extent of its concentration relative to uniform distribution (relative entropy - RE). We apply SI distinctly over the monsoonal precipitation regime (MPR), westerly precipitation regime (WPR) and annual precipitation. For the present climate, neither any single model nor the multi-model mean performs best in all chosen metrics. Models show overall a modest skill in suggesting right timings of the monsoon onset while the RFA slope is generally underestimated. One third of the models fail to capture the monsoon signal over the Indus basin. Mostly, the estimates for SI during WPR are higher than observed for all basins. When looking at MPR, the models typically simulate an SI higher (lower) than observed for the Ganges and Brahmaputra (Indus and Mekong) basins, following the pattern of overestimation (underestimation) of precipitation. Most of the models are biased negative (positive) for RE estimates over the Brahmaputra and Mekong (Indus and Ganges) basins, implying the extent of precipitation concentration for MPR and number of dry days within WPR lower (higher) than observed for these basins. Such skill of the CMIP5 models in representing the present-day monsoonal

  4. Provenance and sediment fluxes in the Irrawaddy (Ayeyarwadi) River

    Science.gov (United States)

    Garzanti, Eduardo; Wang, Jiangang; Vezzoli, Giovanni; Limonta, Mara

    2016-04-01

    .5 and 2.0 Ga (Limonta et al., 2016). Forward mixing calculations based on integrated petrographic and heavy-mineral data (Garzanti et al., 2012) indicate that 60±10% of the total sediment flux is supplied by the Chindwin River and that upper Irrawaddy sand is supplied mainly by the Nmai headwater branch but also significantly from the Mali branch and left-bank tributaries sourced in the northern Shan Plateau. CITED REFERENCES Garzanti E., Resentini A., Vezzoli G., Andò S., Malusà M., Padoan M. 2012. Forward compositional modelling of Alpine orogenic sediments. Sedimentary Geology 280:149-164. Garzanti E., Limonta M., Resentini A., Bandopadhyay P. C., Najman Y., Andò S., Vezzoli G. 2013. Sediment recycling at convergent plate margins (Indo-Burman Ranges and Andaman-Nicobar Ridge). Earth-Science Reviews 123:113-132. Limonta M., Resentini A., Carter A., Bandopadhyay P.C., Garzanti E. 2016. Provenance of Oligocene Andaman Sandstones (Andaman-Nicobar islands): Ganga-Brahmaputra or Irrawaddy derived? In: Bandyopadhyay P., Carter A. (Eds.). The Andaman-Nicobar accretionary ridge geology, tectonics and hazards, Geological Society of London Memoir, in review. Robinson R.A.J., Bird M.I., Oo N.W., Hoey T.B., Aye M.M., Higgitt D.L., Lu X.X., Swe A., Tun T., Win S. L. 2007. The Irrawaddy River sediment flux to the Indian Ocean: the original nineteenth-century data revisited. The Journal of Geology 115:629-640. Wang J.G., Wu F.Y., Tan X.C., Liu C.Z. 2014. Magmatic evolution of the Western Myanmar Arc documented by U-Pb and Hf isotopes in detrital zircon. Tectonophysics 612:97-105.

  5. River Morphology and River Channel Changes

    Institute of Scientific and Technical Information of China (English)

    CHANG Howard H

    2008-01-01

    River morphology has been a subject of great challenge to scientists and engineers who recognize that any effort with regard to river engineering must be based on a proper understanding of the morphological features involved and the responses to the imposed changes. In this paper,an overview of river morphology is presented from the geomorphic viewpoint. Included in the scope are the regime concept, river channel classification, thresholds in river morphology, and geomor-phic analysis of river responses. Analytical approach to river morphology based on the physical principles for the hydraulics of flow and sediment transport processes is also presented. The appli-cation of analytical river morphology is demonstrated by an example. Modeling is the modern tech-nique to determine both short-term and long-term river channel responses to any change in the en-vironment. The physical foundation of fluvial process-response must be applied in formatting a mathematical model. A brief introduction of the mathematical model FLUVIAL-12 is described.

  6. Export of dissolved inorganic nutrients to the northern Indian Ocean from the Indian monsoonal rivers during discharge period

    Science.gov (United States)

    Krishna, M. S.; Prasad, M. H. K.; Rao, D. B.; Viswanadham, R.; Sarma, V. V. S. S.; Reddy, N. P. C.

    2016-01-01

    Coastal regions are highly productive due to the nutrients largely supplied by rivers. To examine the contribution of dissolved inorganic nutrients (DIN) by Indian rivers to coastal waters, data were collected near the freshwater heads of 27 monsoonal rivers of peninsular India during three weeks in late July to mid-August, the middle of the principal runoff period of the southwest monsoon of 2011. Twelve researchers in four groups, equipped with car and portable laboratory equipment, sampled mid-stream of each estuary using mechanized boat, and filtered and partly analyzed the water in the evening. The estimated exports were 0.22 ± 0.05, 0.11 ± 0.03, and 1.03 ± 0.26 Tg yr-1 for dissolved inorganic nitrogen, phosphorus and silicate, respectively. Higher amounts of DIN reach the Bay of Bengal than the Arabian Sea due to the higher volume (∼76%) of discharge to the former. In contrast, the export of dissolved inorganic nitrogen is almost same to the Bay of Bengal (0.12 ± 0.03 Tg yr-1) and Arabian Sea (0.10 ± 0.02 Tg yr-1) principally due to the polluted Narmada and Tapti rivers in the northwest. Including input from the glacial rivers, Ganges, Brahmaputra and Indus, it is estimated that the northern Indian Ocean receives ∼1.84 ± 0.46, 0.28 ± 0.07 and 3.58 ± 0.89 Tg yr-1 of nitrate, phosphate and silicate, respectively, which are significantly lower than the earlier estimates of DIN export from the Indian rivers based on DIN measured in the mid or upstream rivers. Such low fluxes in this study were attributed to efficient retention/elimination of DIN (∼91%) before reaching the coastal ocean. Hence, this study suggests that the importance of sampling locations for estimating nutrient fluxes to the coastal ocean. Riverine DIN export of 1.84 ± 0.46 Tg yr-1 would support 12.2 ± 3.1 Tg C yr-1 of new production in coastal waters of the northern Indian Ocean that results in a removal of 12.2 ± 3.1 Tg atmospheric CO2 yr-1.

  7. Structure, provenance and residence time of terrestrial organic carbon: insights from Programmed temperature Pyrolysis-Combustion of river sediments

    Science.gov (United States)

    Feng, X.; Galy, V.; Rosenheim, B. E.; Roe, K. M.; Williams, E. K.

    2010-12-01

    be itself composed of several components characterized by different reactivity and radiocarbon content. In sediments from the Ganges-Brahmaputra river system we identified at least two main constituents of the biospheric OC pool: 1) a labile component whose radiocarbon content agrees with that of vascular plant biomarkers and, 2) a refractory component, characterized by a very long residence time (ca. 17 Ka). Our first results indicate that PTP-CS has very promising potential to quantify the contribution and residence time of the different components of riverine OC. We expect it will permit significant advance in our understanding of the rate of exchange and flux of terrestrial OC during continental erosion.

  8. Allegheny County Major Rivers

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — This dataset contains locations of major rivers that flow through Allegheny County. These shapes have been taken from the Hydrology dataset. The Ohio River,...

  9. Qingjiang River Developer

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    THE 400-kilometer Qingjiang River, second tributary of the Yangtze River in Hubei Province, has a drainage area of 17,000 square kilometers. Its advantageous natural conditions have made it a key water power development project.

  10. Iowa's Sovereign Meandered Rivers

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — This data set depicts Iowa's Meandered Rivers. These rivers are deemed sovereign land & therefore require any person wishing to conduct construction activities...

  11. River and Stream Pollution

    Science.gov (United States)

    ... Topics Games Activities Lessons MENU River and Stream Pollution Kids Homepage Topics Pollution River and Stream Pollution ... stream in the first place by disturbing the land as little as possible. Farmers and construction workers ...

  12. Onchocerciasis (River Blindness) FAQs

    Science.gov (United States)

    ... The CDC Parasites - Onchocerciasis (also known as River Blindness) Note: Javascript is disabled or is not supported ... infected Simulium blackfly. It is also called River Blindness because the fly that transmits infection breeds in ...

  13. Mithi River Restoration Project

    OpenAIRE

    Sanghani, Himanshu

    2009-01-01

    It took only few years to turn a naturally owing river into a drain. 17.84 k.m stretch of MithiNadi (river), an arterial river, running along north-south axis of Bombay (Mumbai) is facing the grimproblems of backyard atrocities. Finding its way through the odds of household garbage, industrialsewage, other pollutants and encroachments, Mithi river originates from the conuence of two essentialreservoirs; Vihar Lake and Powai Lake and merging with Arabian Sea at Mahim creek. The stategovernment...

  14. Measuring River Pollution

    Science.gov (United States)

    Ayyavoo, Gabriel

    2004-01-01

    The Don River watershed is located within Canada's most highly urbanized area--metropolitan Toronto. Many residential and commercial uses, including alterations to the river's course with bridges, have had a significant impact on the Don's fauna and flora. Pollutants have degraded the river's water quality, a situation exacerbated by the…

  15. 76 FR 51887 - Safety Zone; Patuxent River, Patuxent River, MD

    Science.gov (United States)

    2011-08-19

    ...) entitled ``Safety Zone; Patuxent River, Patuxent River, MD'' in the Federal Register (76 FR 36447). We... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Patuxent River, Patuxent River, MD AGENCY... safety zone during the ``NAS Patuxent River Air Expo '11,'' which consists of aerial...

  16. Origins, seasonality, and fluxes of organic matter in the Congo River

    Science.gov (United States)

    Spencer, Robert G. M.; Hernes, Peter J.; Dinga, Bienvenu; Wabakanghanzi, Jose N.; Drake, Travis W.; Six, Johan

    2016-07-01

    The Congo River in central Africa represents a major source of organic matter (OM) to the Atlantic Ocean. This study examined elemental (%OC, %N, and C:N), stable isotopic (δ13C and δ15N), and biomarker composition (lignin phenols) of particulate OM (POM) and dissolved OM (DOM) across the seasonal hydrograph. Even though the Congo exhibits an extremely stable intra-annual discharge regime, seasonal variability in OM composition was evident. DOM appears predominantly derived from vascular plant inputs with greater relative contribution during the rising limb and peak in discharge associated with the major November-December discharge maximum. Generally, POM appears to be sourced from soil-derived mineral-associated OM (low C:N, low Λ8, and higher (Ad:Al)v) but the relative proportion of fresh vascular plant material (higher C:N, higher Λ8, and lower (Ad:Al)v) increases with higher discharge. During the study period (September 2009 to November 2010) the Congo exported 29.21 Tg yr-1 of total suspended sediment (TSS), 1.96 Tg yr-1 of particulate organic carbon (POC), and 12.48 Tg yr-1 of dissolved organic carbon. The Congo exports an order of magnitude lower TSS load in comparison to other major riverine sources of TSS (e.g., Ganges and Brahmaputra), but due to its OM-rich character it actually exports a comparable amount of POC. The Congo is also 2.5 times more efficient at exporting dissolved lignin per unit volume compared to the Amazon. Including Congo dissolved lignin data in residence time calculations for lignin in the Atlantic Ocean results in an approximately 10% reduction from the existing estimate, suggesting that this material is more reactive than previously thought.

  17. River Restoration and Meanders

    OpenAIRE

    G. Mathias Kondolf

    2006-01-01

    Among the most visually striking river restoration projects are those that involve the creation of a new channel, often in a new alignment and generally with a form and dimensions that are different from those of the preproject channel. These channel reconstruction projects often have the objective of creating a stable, single-thread, meandering channel, even on rivers that were not historically meandering, on rivers whose sediment load and flow regime would not be consistent with such stable...

  18. Dispersion in Alluvial River

    OpenAIRE

    Ferdousi, Amena

    2014-01-01

    River pollution is the contamination of river water by pollutant being discharged directly or indirectly on it. Depending on the degree of pollutant concentration, subsequent negative environmental effects such as oxygen depletion and severe reductions in water quality may occur which affect the whole environment. River pollution can then cause a serious threat for fresh water and as well as the entire living creatures. Dispersion in natural stream is the ability of a stream to dilute soluble...

  19. RIVER FLOW CONDITIONS AND DYNAMIC STATE ANALYSIS OF PAHANG RIVER

    OpenAIRE

    Muhamad Barzani Gasim; M. E. Toriman; Mushrifah Idris; Pan Ian Lun; M. K.A. Kamarudin; A. A. Nor Azlina; Mazlin Mokhtar; S.A. Sharifah Mastura

    2013-01-01

    Pahang River (Sg. Pahang) is the longest river in Peninsular Malaysia. Flood is a common event in Pahang River Basin during wet season which triggered by monsoon season. The hydrodynamic study of Pahang River should be well understood especially when it is a target of northeast monsoon which influenced the Pahang River Basin every year (from November to March). 17 river cross section stations were selected and used to measure its drainage capacity, hydraulic parameters and estimation of flow ...

  20. Park Service prepares river plans

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This article is on the designation of sections of the Missouri River, Niobrara River and Verdigre Creek in Nebraska and South Dakota as a national recreation river...

  1. Tidal river dynamics

    NARCIS (Netherlands)

    Hoitink, A.J.F.; Jay, D.A.

    2016-01-01

    Tidal rivers are a vital and little studied nexus between physical oceanography and hydrology. It is only in the last few decades that substantial research efforts have been focused on the interactions of river discharge with tidal waves and storm surges into regions beyond the limit of salinity

  2. Reining the River

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Concerned about the effects of increasing water scarcity on economic development, China hopes a new law will save the Yellow River The first day of August marked what could be a new page in the history of China's long-suffering "mother river." That day, a regulation took effect that for the first time in histo-

  3. 33 CFR 117.734 - Navesink River (Swimming River).

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Navesink River (Swimming River... BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.734 Navesink River (Swimming River). The Oceanic Bridge, mile 4.5, shall open on signal; except that, from December 1...

  4. One-dimensional modeling of a recent Ganga avulsion: Assessing the potential effect of tectonic subsidence on a large river

    Science.gov (United States)

    Gupta, Niladri; Kleinhans, Maarten G.; Addink, Elisabeth A.; Atkinson, Peter M.; Carling, Paul A.

    2014-05-01

    by residual channel filling but in the much larger Ganges results in morphologically active anabranches. The model results reveal that neither a gradient advantage nor a bend upstream of the bifurcation leads to an avulsion within centuries as has been observed in some large rivers in tectonically inactive regions. On the other hand, a realistic tectonic uplift of the old branch or subsidence of the new branch may force an avulsion to take place quickly, and historical data show that the study area is seismically active. The combination of these factors leads to a realistic modeled avulsion duration of less than three centuries. Historical data indicate that these general conclusions might also apply to other large rivers in this region, e.g. the Brahmaputra and the Teesta. We conclude that large rivers may avulse quickly in response to tectonics but attain an anabranching pattern because of the large dimension of the residual channel and backwater effects.

  5. Modeling river delta formation

    CERN Document Server

    Seybold, Hansjörg; Herrmann, Hans J

    2007-01-01

    A new model to simulate the time evolution of river delta formation process is presented. It is based on the continuity equation for water and sediment flow and a phenomenological sedimentation/ erosion law. Different delta types are reproduced using different parameters and erosion rules. The structures of the calculated patterns are analyzed in space and time and compared with real data patterns. Furthermore our model is capable to simulate the rich dynamics related to the switching of the mouth of the river delta. The simulation results are then compared with geological records for the Mississippi river.

  6. Modeling river delta formation.

    Science.gov (United States)

    Seybold, Hansjörg; Andrade, José S; Herrmann, Hans J

    2007-10-23

    A model to simulate the time evolution of river delta formation process is presented. It is based on the continuity equation for water and sediment flow and a phenomenological sedimentation/erosion law. Different delta types are reproduced by using different parameters and erosion rules. The structures of the calculated patterns are analyzed in space and time and compared with real data patterns. Furthermore, our model is capable of simulating the rich dynamics related to the switching of the mouth of the river delta. The simulation results are then compared with geological records for the Mississippi River. PMID:17940031

  7. Dulbi River goose survey

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A survey of white-fronted goose (Anser albifrons) and Canada goose (Branta canadensis) broods was conducted on 58 3/8 miles of the Dulbi River in Alaska. Four...

  8. Russian River Analysis

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is an analysis and summary of progress toward achieving the interim management objectives for the Russian River during the 1979 season. Additionally,...

  9. Wild and Scenic Rivers

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This map layer portrays the linear federally-owned land features (i.e., national parkways, wild and scenic rivers, etc.) of the United States, Puerto Rico, and the...

  10. Management recommendations: Bear River

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is a review of land management practices at the Bear River Migratory Bird Refuge, by a land use specialist. Recommendations, time frame and additional...

  11. The Carmans River Story

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — In this study, undertaken as an independent project at Bellport High School, the authors have attempted to provide a historical description of the Carmans River...

  12. Down to the River

    DEFF Research Database (Denmark)

    Wessels, Josepha Ivanka

    2015-01-01

    Currently there is no coherent or sustainable water cooperation among the five states—Israel, Jordan, Lebanon, Palestinian territories and Syria—that share the Jordan River. Why do people not cooperate on sustainable river basin management, even if it seems the most rational course from the persp......Currently there is no coherent or sustainable water cooperation among the five states—Israel, Jordan, Lebanon, Palestinian territories and Syria—that share the Jordan River. Why do people not cooperate on sustainable river basin management, even if it seems the most rational course from...... the perspective of economic benefits? I hypothesize that the political uses of citizenship, identity and security at the local level hamper cooperation at the basin level and ignore cognitive dimensions of violence and conflict. In this article, I have chosen the Israeli-occupied Golan Heights as a case study...

  13. Mackenzie River Delta, Canada

    Science.gov (United States)

    2007-01-01

    The Mackenzie River in the Northwest Territories, Canada, with its headstreams the Peace and Finley, is the longest river in North America at 4241 km, and drains an area of 1,805,000 square km. The large marshy delta provides habitat for migrating Snow Geese, Tundra Swans, Brant, and other waterfowl. The estuary is a calving area for Beluga whales. The Mackenzie (previously the Disappointment River) was named after Alexander Mackenzie who travelled the river while trying to reach the Pacific in 1789. The image was acquired on August 4, 2005, covers an area of 55.8 x 55.8 km, and is located at 68.6 degrees north latitude, 134.7 degrees west longitude. The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  14. The rivers of civilization

    Science.gov (United States)

    Macklin, Mark G.; Lewin, John

    2015-04-01

    The hydromorphic regimes that underpinned Old World river-based civilizations are reviewed in light of recent research. Notable Holocene climatic changes varied from region to region, whilst the dynamics of floodplain environments were equally diverse, with river channel changes significantly affecting human settlement. There were longer-term trends in Holocene hydroclimate and multi-centennial length 'flood-rich' and 'flood-poor' episodes. These impacted on five identified flooding and settlement scenarios: (i) alluvial fans and aprons; (ii) laterally mobile rivers; (iii) rivers with well-developed levees and flood basins; (iv) river systems characterised by avulsions and floodouts; and (v) large river-fed wetlands. This gave a range of changes that were either more or less regular or incremental from year-to-year (and thus potentially manageable) or catastrophic. The latter might be sudden during a flood event or a few seasons (acute), or over longer periods extending over many decades or even centuries (chronic). The geomorphic and environmental impacts of these events on riparian societies were very often irreversible. Contrasts are made between allogenic and autogenic mechanism for imposing environmental stress on riverine communities and a distinction is made between channel avulsion and contraction responses. Floods, droughts and river channel changes can precondition as well as trigger environmental crises and societal collapse. The Nile system currently offers the best set of independently dated Holocene fluvial and archaeological records, and the contrasted effects of changing hydromorphological regimes on floodwater farming are examined. The persistence of civilizations depended essentially on the societies that maintained them, but they were also understandably resilient in some environments (Pharaonic Egypt in the Egyptian Nile), appear to have had more limited windows of opportunity in others (the Kerma Kingdom in the Nubian Nile), or required

  15. Wind River: A Wild and Scenic River Analysis: Preliminary draft

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Wind River meets the criteria for inclusion in the National Wild and Scenic Rivers System. Subject to valid existing rights, the minerals in Federal lands which...

  16. Study on the Reutilization of River Sediment

    Institute of Scientific and Technical Information of China (English)

    LIU Gui-yun; JIANG Pei-hua; XI Dan-li

    2002-01-01

    Main components and properties of river sediment are introduced. Secondary pollution of river sediments to the water quality of the river is clarified. The methods of the reutilization of river sediment are elucidated.

  17. 33 CFR 207.380 - Red Lake River, Minn.; logging regulations for portion of river above Thief River Falls.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Red Lake River, Minn.; logging... Red Lake River, Minn.; logging regulations for portion of river above Thief River Falls. (a) Parties wishing to run logs on Red Lake River must provide storage booms near the head of the river to take...

  18. 76 FR 36447 - Safety Zone; Patuxent River, Patuxent River, MD

    Science.gov (United States)

    2011-06-22

    ..., 2008, issue of the Federal Register (73 FR 3316). Public meeting We do not now plan to hold a public... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Patuxent River, Patuxent River, MD AGENCY... a temporary safety zone during the ``NAS Patuxent River Air Expo '11'', which consists of...

  19. RIVER FLOW CONDITIONS AND DYNAMIC STATE ANALYSIS OF PAHANG RIVER

    Directory of Open Access Journals (Sweden)

    Muhamad Barzani Gasim

    2013-01-01

    Full Text Available Pahang River (Sg. Pahang is the longest river in Peninsular Malaysia. Flood is a common event in Pahang River Basin during wet season which triggered by monsoon season. The hydrodynamic study of Pahang River should be well understood especially when it is a target of northeast monsoon which influenced the Pahang River Basin every year (from November to March. 17 river cross section stations were selected and used to measure its drainage capacity, hydraulic parameters and estimation of flow discharge. Long term (1980 to 2009 variation of hydrologic data series comprised of river flow, river stage and rainfall data were analyzed based on the Department of Irrigation and Drainage (DID Malaysia record. Monthly rainfall was recorded from Sg. Yap, Temerloh and Lubuk Paku Rainfall Stations. Two hydrologic sampling trips had been carried out; first sampling on January 2010 and second sampling on February 2010. The study indicates that velocity and river flow measurement during first sampling ranged from 0.308 to 0.582 m sec-1 and 153.282 to 439.684 m3 sec-1. Meanwhile, during second sampling, the velocity and river flow ranged from 0.217 to 0.484 and 52.071 to 304.485 m3 sec-1, respectively. Floods were occurred annually at Pahang River especially during northeast monsoon, these events are expected to be stimulated by the inconsistent condition of width and depth along Pahang River which finally create sedimentation and meandering characteristic.

  20. Sprague River Oregon Floodplain 2000

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Sprague River drains 4090 square kilometers in south-central Oregon before flowing into the Williamson River and upper Klamath Lake. In cooperation with the...

  1. Sprague River Oregon Floodplain Centerline

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Sprague River drains 4090 square kilometers in south-central Oregon before flowing into the Williamson River and upper Klamath Lake. In cooperation with the...

  2. Sprague River Oregon Vegetation 1968

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Sprague River drains 4090 square kilometers in south-central Oregon before flowing into the Williamson River and upper Klamath Lake. In cooperation with the...

  3. Missouri River 1943 Compact Line

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — Flood Control, Bank Stabilization and development of a navigational channel on the Missouri River had a great impact on the river and adjacent lands. The new...

  4. Sprague River Oregon Bars 1940

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Sprague River drains 4090 square kilometers in south-central Oregon before flowing into the Williamson River and upper Klamath Lake. In cooperation with the...

  5. Sprague River Oregon Bars 2000

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Sprague River drains 4090 square kilometers in south-central Oregon before flowing into the Williamson River and upper Klamath Lake. In cooperation with the...

  6. Sprague River Oregon Bars 1968

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Sprague River drains 4090 square kilometers in south-central Oregon before flowing into the Williamson River and upper Klamath Lake. In cooperation with the...

  7. Sprague River Oregon Floodplain 1968

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Sprague River drains 4090 square kilometers in south-central Oregon before flowing into the Williamson River and upper Klamath Lake. In cooperation with the...

  8. Sprague River Oregon Centerline 1940

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Sprague River drains 4090 square kilometers in south-central Oregon before flowing into the Williamson River and upper Klamath Lake. In cooperation with the...

  9. Sprague River Oregon Water 1940

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Sprague River drains 4090 square kilometers in south-central Oregon before flowing into the Williamson River and upper Klamath Lake. In cooperation with the...

  10. The River Lune fact file

    OpenAIRE

    1994-01-01

    This document provides a brief introduction to the River Lune catchment and the role that the National Rivers Authority plays in catchment management. Included are a map of the catchment and short introductions to fisheries and characteristics of the catchment.

  11. Sprague River Oregon Centerline 2000

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Sprague River drains 4090 square kilometers in south-central Oregon before flowing into the Williamson River and upper Klamath Lake. In cooperation with the...

  12. Sprague River Oregon Centerline 1968

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Sprague River drains 4090 square kilometers in south-central Oregon before flowing into the Williamson River and upper Klamath Lake. In cooperation with the...

  13. Sprague River Oregon Floodplain Boundary

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Sprague River drains 4090 square kilometers in south-central Oregon before flowing into the Williamson River and upper Klamath Lake. In cooperation with the...

  14. Stochastic modelling of river morphodynamics

    OpenAIRE

    Van Vuren, B.G.

    2005-01-01

    Modern river management has to reconcile a number of functions, such as protection against floods and provision of safe and efficient navigation, floodplain agriculture, ecology and recreation. Knowledge on uncertainty in fluvial processes is important to make this possible, to design effective river engineering works, for operational forecasting and for the maintenance of the river system. In this research the focus is in particular on the quantification of uncertainty in river morphodynamic...

  15. Stochastic Modelling of River Geometry

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Schaarup-Jensen, K.

    1996-01-01

    Numerical hydrodynamic river models are used in a large number of applications to estimate critical events for rivers. These estimates are subject to a number of uncertainties. In this paper, the problem to evaluate these estimates using probabilistic methods is considered. Stochastic models...... for river geometries are formulated and a coupling between hydraulic computational methods and numerical reliability methods is presented....

  16. Ecological River Basin Management.

    Science.gov (United States)

    Smith, Anthony Wayne

    Addressing the Seventh American Water Resources Conference, Washington, D. C., October, 1971, Anthony Wayne Smith, President, National Parks and Conservation Association, presents an expose on how rivers should be managed by methods which restores and preserve the natural life balances of the localities and regions through which they flow. The…

  17. Discover the Nile River

    Science.gov (United States)

    Project WET Foundation, 2009

    2009-01-01

    Bordering on the Fantastic. As the longest river on earth, the Nile passes through 10 countries. Presented through a wide range of activities and a winning array of games, it's also unsurpassed at taking young minds into exploring the world of water, as well as natural and man made wonders.

  18. Alligator Rivers Region

    International Nuclear Information System (INIS)

    An introduction to the Alligator Rivers Region is presented. It contains general information regarding the physiography, climate, hydrology and mining of the region. The Alligator Rivers Region is within an ancient basin, the Pine Creek Geosyncline, which has an area of approximately 66000 km2. The Geosyncline has a history of mineral exploitation dating back to 1865, during which time 16 metals have been extracted (silver, arsenic, gold, bismuth, cadmium, cobalt, copper, iron, manganese, molybdenum, lead, tin, tantalum, uranium, tungsten, zinc). Uranium exploration in the Pine Creek Geosyncline was stimulated by the discovery in 1949 of secondary uranium mineralisation near Rum June, 70 km south-east of Darwin. This was followed by a decade of intense exploration activity resulting in the discoveries of economic uranium ore bodies at Rum Jungle and in the upper reaches of the South Alligator River Valley. All the known major uranium deposits of the East Alligator River uranium field have been discovered since 1969. The present known resources of the Geosyncline are approximately 360 000 tonnes of contained U3O8. 2 refs., 2 figs., 1 tab

  19. Two Pontic rivers

    DEFF Research Database (Denmark)

    Bekker-Nielsen, Tønnes; Jensen, Marit

    2015-01-01

    The accounts of the landscape around the Iris (Yeşilirmak) and the Thermodon (Terme) given by ancient authors are diverse and often contradictory. The Periegesis of the World by Dionysius of Alexandria, a didactic poem written in the early IInd c. A.D., established an image of the two rivers that...

  20. Comparative Study of Flood Risk Management and Land Use in the Deltas of Rhine River, Yellow River and Mississippi River

    NARCIS (Netherlands)

    Huang B; Guangzhou, M.

    2007-01-01

    The Rhine River in the Netherlands, the Yellow River in China and the Mississippi River in the U.S. are three great rivers in the world. Each of them is performing a significant role in the country. The delta area for each river, in particular, is served as the centre in importance and commonly the

  1. Modeling river delta formation

    OpenAIRE

    Seybold, Hansjörg; Andrade, José S.; Herrmann, Hans J.

    2007-01-01

    A model to simulate the time evolution of river delta formation process is presented. It is based on the continuity equation for water and sediment flow and a phenomenological sedimentation/erosion law. Different delta types are reproduced by using different parameters and erosion rules. The structures of the calculated patterns are analyzed in space and time and compared with real data patterns. Furthermore, our model is capable of simulating the rich dynamics related to the switching of the...

  2. Onilahy River, Madagascar

    Science.gov (United States)

    1982-01-01

    Near the southern tip of Madagascar, the Onilahy River (23.5S, 44E) drains a near barren landscape, the result of rapid deforestation for quick profits from the lumber industry with no regard to the environmental impact. At the turn of the century, the island was a lush tropical paradise with about 90 percent of the surface forested. Now, at the close of the century, only about 10 percent of the forests remain in inaccessible rugged terrain.

  3. River and Human Rights

    Institute of Scientific and Technical Information of China (English)

    NIE WUGANG; MENG JIA

    2011-01-01

    @@ Nothing is like a river.It seems coming from nowhere, far back into antiquity.It is originated from drops of water and converged into a long stream that flows ceaselessly.It benefits the vast expanse of land and nourishes all the living on it.It stretches and undulates,forming ponds and lakes of different depths.It is moving or motionless,overflowing with vigor and vitality.

  4. River habitats for salmonids on the River Lune catchment

    OpenAIRE

    2000-01-01

    An extensive survey of the River Lune using River Habitat Survey (RHS) was commissioned to assess the habitat quality of the Lune for salmonid fish. The main river on the Lune and tributaries were divided into 500m sections. A sample of 103 sections (25% of the total classified length) was randomly selected and surveyed in February/March 99. A Habitat Modification Score (HMS) describing the level of habitat modification was derived for each site and compared to the whole reference net...

  5. Investigation on Water Pollution of Four Rivers in Coastal Wetland of Yellow River Estuary

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    [Objective] The study aimed at analysing water pollution of four rivers in coastal wetland of Yellow River estuary. [Method] Taking four seriously polluted rivers (Guangli River, Shenxian Ditch, Tiao River and Chao River) in coastal wetland of Yellow River estuary as study objects, water samples were collected from the four rivers in May (dry period), August (wet period) and November (normal period) in 2009 and 2010 respectively, then pollution indices like nutritive salts, COD, chlorophyll-a, petroleum, et...

  6. How do atmospheric rivers form?

    OpenAIRE

    Helen F. Dacre; Clark, Peter A.; Martinez-Alvarado, Oscar; Stringer, Marc A.; Lavers, David A.

    2014-01-01

    Identifying the source of atmospheric rivers: Are they rivers of moisture exported from the subtropics or footprints left behind by poleward travelling storms? The term atmospheric river is used to describe corridors of strong water vapor transport in the troposphere. Filaments of enhanced water vapor, commonly observed in satellite imagery extending from the subtropics to the extratropics, are routinely used as a proxy for identifying these regions of strong water vapor transport. The pre...

  7. River Restoration and Meanders

    Directory of Open Access Journals (Sweden)

    G. Mathias Kondolf

    2006-12-01

    Full Text Available Among the most visually striking river restoration projects are those that involve the creation of a new channel, often in a new alignment and generally with a form and dimensions that are different from those of the preproject channel. These channel reconstruction projects often have the objective of creating a stable, single-thread, meandering channel, even on rivers that were not historically meandering, on rivers whose sediment load and flow regime would not be consistent with such stable channels, or on already sinuous channels whose bends are not symmetrical. Such meandering channels are often specified by the Rosgen classification system, a popular restoration design approach. Although most projects of this type have not been subject to objective evaluation, completed postproject appraisals show that many of these projects failed within months or years of construction. Despite its, at best, mixed results, this classification and form-based approach continues to be popular because it is easy to apply, because it is accessible to those without formal training in fluvial geomorphology, and probably because it satisfies a deep-seated, although unrecognized, cultural preference for single-thread meandering channels. This preference is consistent with 18th-century English landscape theories, which held the serpentine form to be ideal and led to widespread construction of meandering channels on the country estates of the era. The preference for stability in restored channels seems to be widely accepted by practitioners and funders despite the fact that it is antithetical to research showing that dynamically migrating channels have the greatest ecological richness.

  8. Skjern River Restoration Counterfactual

    DEFF Research Database (Denmark)

    Clemmensen, Thomas Juel

    2014-01-01

    heritage. While the meanders of the Skjern River were reconstructed according to its assumed course in 1870s, the embanked canal, which was the main feature and symbol of a comprehensive cultivation project from the 1960s, was deconstructed and reduced to incomprehensible traces of the past. Not only did...... history and more openness towards constant change. In this approach the idea of palimpsest as metaphor for the cultural landscape plays an important role. Rather than being an obstacle for the restoration of nature, the historical layer following the comprehensive cultivation project from the 1960s...

  9. Taizhou Yangtze River Bridge

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Taizhou Bridge lies between Taizhou, Zhenjiang and Changzhou City in Jiangsu Province. The total length of Taizhou Bridge is 62.088 kin. The whole line is designed by freeway codes with six lanes in two directions. The wholeinvestment is 9.37 billion RMB and the planned construction duration is 5.5 years. The main bridge crossing the Yangtze River is a continuous three-pylon two-span suspension bridge with the main span of 1 080 m. The bridge system is realized for the first time and ranks first in the world until now.

  10. "Climate change impact on water resources - a challenge for IWRM". BRAHMATWINN - Twinning European and South Asian River Basins to enhance capacity and implement adaptive management approaches

    Science.gov (United States)

    Bartosch, A.; Pechstädt, J.; Müller Schmied, H.; Flügel, W.-A.

    2009-04-01

    BRAHMATWINN addresses climate change impact of the hydrology of two macro-scale river basins having headwaters in alpine mountain massifs. The project will elaborate on the consequential vulnerability of present IWRM and river basin management that have been persistent in these basins during the past decades and will develop tested approaches and technologies for adaptive IWRM and resilience. The overall objective of BRAHMATWINN is to enhance and improve capacity to carry out a harmonized integrated water resources management (IWRM) approach as addressed by the European Water Initiative (EWI) in headwater river systems of alpine mountain massifs in respect to impacts from likely climate change, and to transfer professional IWRM expertise, approaches and tools based on case studies carried out in twinning European and Asian river basins, the Upper Danube River Basin (UDRB) and the Upper Brahmaputra River Basin (UBRB). Sustainable IWRM in river basins of such kind face common problems: (i) floods e.g. during spring melt or heavy storms and droughts during summer; (ii) competing water demands for agriculture, hydropower, rural, urban and industrial development, and the environment; (iii) pollution from point as well as diffuse sources; and (iv) socio-economic and legal issues related to water allocation. Besides those common topics both basins also differ in other issues requiring the adaptation of the IWRM tools; these are for example climate conditions, the density of monitoring network, political framework and trans-boundary conflicts. An IWRM has to consider all water-related issues like the securing of water supply for the population in sufficient quantity and quality, the protection of the ecological function of water bodies and it has to consider the probability of natural hazards like floods and droughts. Furthermore the resource water should be threatened in a way that the needs of future generations can be satisfied. Sustainable development is one of the

  11. Quality of river Krka in middle stream

    OpenAIRE

    Nučič, Benjamin

    2011-01-01

    Since beginning of the mankind people tend to settle near rivers. The rivers represent source of drinkable water, possibility for farming, industry and other branches. Overall the rivers are ideal solution to eliminate waste waters. Rivers have the ability to decompose organic material to anorganic with the help of microorganisms. We call this self-cleaning river ability. Rough measurement for self-cleaning river ability is biochemical oxygen demand, which is increased by organic pollution. T...

  12. Concluding Remarks on River Conservation

    OpenAIRE

    Elosegi, Arturo; Sabater, Sergi; Boulton, Andrew

    2013-01-01

    We have pragmatic and ethical obligations to conserve rivers and their biodiversity. This chapter outlines how and why river conservation is important. To make a difference, we must act as individuals and groups, using water wisely and protecting vulnerable assets such as water quality, riparian zones and aquatic biodiversity

  13. Treasure Along the Parker River.

    Science.gov (United States)

    Fitzpatrick, Ann-Marie; And Others

    Designed so that 100 to 125 heterogeneously grouped 7th and 8th grade students and a team of 5 core teachers might experience and discover the natural and historical "treasure" in the Parker River area of Massachusetts, this interdisciplinary unit centers on a hike to Parker River (6.7 miles) and visits to a cemetery, a monument, and Old Town…

  14. Hood River Passive House

    Energy Technology Data Exchange (ETDEWEB)

    Hales, David [BA-PIRC, Spokane, WA (United States)

    2014-01-01

    The Hood River Passive Project was developed by Root Design Build of Hood River Oregon using the Passive House Planning Package (PHPP) to meet all of the requirements for certification under the European Passive House standards. The Passive House design approach has been gaining momentum among residential designers for custom homes and BEopt modeling indicates that these designs may actually exceed the goal of the U.S. Department of Energy's (DOE) Building America program to "reduce home energy use by 30%-50% (compared to 2009 energy codes for new homes). This report documents the short term test results of the Shift House and compares the results of PHPP and BEopt modeling of the project. The design includes high R-Value assemblies, extremely tight construction, high performance doors and windows, solar thermal DHW, heat recovery ventilation, moveable external shutters and a high performance ductless mini-split heat pump. Cost analysis indicates that many of the measures implemented in this project did not meet the BA standard for cost neutrality. The ductless mini-split heat pump, lighting and advanced air leakage control were the most cost effective measures. The future challenge will be to value engineer the performance levels indicated here in modeling using production based practices at a significantly lower cost.

  15. Columbia River water quality monitoring

    International Nuclear Information System (INIS)

    Waste water from Hanford activities is discharged at eight points along the Hanford reach of the Columbia River. These discharges consist of backwash water from water intake screens, cooling water, river bank springs, water storage tank overflow, and fish laboratory waste water. Each discharge point is identified in an existing National Pollutant Discharge Elimination System (NPDES) permit issued by the EPA. Effluents from each of these outfalls are routinely monitored and reported by the operating contractors as required by their NPDES permits. Measurements of several Columbia River water quality parameters were conducted routinely during 1982 both upstream and downstream of the Hanford Site to monitor any effects on the river that may be attributable to Hanford discharges and to determine compliance with the Class A designation requirements. The measurements indicated that Hanford operations had a minimal, if any, impact on the quality of the Columbia River water

  16. River-Based Experiential Learning: the Bear River Fellows Program

    Science.gov (United States)

    Rosenberg, D. E.; Shirley, B.; Roark, M. F.

    2012-12-01

    The Department of Civil and Environmental Engineering, Outdoor Recreation, and Parks and Recreation programs at Utah State University (USU) have partnered to offer a new, unique river-based experiential learning opportunity for undergraduates called the Bear River Fellows Program. The program allows incoming freshmen Fellows to experience a river first hand during a 5-day/4-night river trip on the nearby Bear River two weeks before the start of their first Fall semester. As part of the program, Fellows will navigate the Bear River in canoes, camp along the banks, interact with local water and environmental managers, collect channel cross section, stream flow, vegetation cover, and topological complexity data, meet other incoming freshmen, interact with faculty and graduate students, develop boating and leadership skills, problem solve, and participate as full members of the trip team. Subsequently, Fellows will get paid as undergraduate researchers during their Fall and Spring Freshman semesters to analyze, synthesize, and present the field data they collect. The program is a collaborative effort between two USU academic units and the (non-academic) division of Student Services and supports a larger National Science Foundation funded environmental modelling and management project for the lower Bear River, Utah watershed. We have advertised the program via Facebook and emails to incoming USU freshmen, received 35 applications (60% women), and accepted 5 Fellows into the program (3 female and 2 male). The river trip departs August 14, 2012. The poster will overview the Bear River Fellows Program and present qualitative and preliminary outcomes emerging from the trip and Fellows' work through the Fall semester with the field data they collect. We will also undertake more rigorous and longer longitudinal quantitative evaluation of Program outcomes (for example, in problem-solving and leadership) both in Spring 2013 and in subsequent 2013 and 2014 offerings of the

  17. Alligator Rivers analogue project

    International Nuclear Information System (INIS)

    Australian Nuclear Science and Technology Organization has extensively evaluated uranium ore bodies in the Alligator Rivers Uranium Province in Australia as analogues of radioactive waste repositories. The work was extended for a three-year program as an international project based on the Koongarra uranium deposit and sponsored by the OECD Nuclear Energy Agency. The technical program comprises six major sub-projects involving modelling and experimental work: modelling of radionuclide migration; hydrogeology of the Koongarra uranium deposit; uranium/thorium series disequilibria studies; groundwater and colloid studies; fission product studies; transuranic nuclide studies; an outline of the technical programs and a summary of progress in the technical sub-projects is given. This is followed by a series of technical reports which briefly describe current research tasks, and which have been separately indexed

  18. Uplift histories from river profiles

    Science.gov (United States)

    Pritchard, D.; Roberts, G. G.; White, N. J.; Richardson, C. N.

    2009-12-01

    Longitudinal river profiles, where elevation of a river bed is plotted as a function of distance along the river bed, contain information about uplift rate. When a region adjacent to a reference level (e.g., sea level) is uplifted, a rapid change in gradient occurs near the river mouth. The erosional process causes this change in gradient to migrate upstream. Thus a river profile is effectively a ‘tape recording’ of the uplift rate history, provided that the erosional process can be adequately parameterized. Here, we use a non-linear equation to relate the shape of a river profile, z(x), to uplift rate history, U(t). If erosion is assumed to be dominated by knickpoint retreat, an inverse model can be formulated and used to calculate uplift rate histories. Our model builds upon standard stream profile analysis, which focuses on the relationship between profile slope and drainage area. We have applied this analytical approach to river profiles from the Bié Dome, Angola. Calculated uplift rate histories agree with independent geologic estimates.

  19. PCBs in the Harlem River

    Science.gov (United States)

    Wang, J.

    2012-12-01

    Polychlorinated biphenyls (PCBs) are persistent, toxic and bioaccumulated contaminants of great environmental concern. PCB is a tracer of wastewater, stormwater and CSOs inputs; PCBs contamination of fish is a main environmental concern for the Harlem River. PCBs in the Harlem River are from combined sewer overflows (CSOs), stormwater runoff, wastewater, as well as upper Hudson GE (General Electric at Fort Edward)'s release. PCBs affect human health mostly from contaminated fish consumption. Many research focused on PCBs in the Hudson River and New York/New Jersey Harbor. However, PCBs source, transport and environmental impact in the Harlem River-a natural straight that connects the Hudson River and the East River, had not been well studied. In this research, water sample were collected from the Harlem River and analyzed PCBs by HR GC/MS (High resolution gas chromatography mass spectrophotometer). Preliminary results showed that certain PCBs congeners in the water column. Results also indicated that nutrients (phosphorus and ammonia) as well as bacteria levels exceeded EPA standards: Total phosphorus-10μg/L, total nitrogen-0.38mg/L; E.Coli-126 MPN/100ml, Enterococcus- 104MPN/100ml, Fecal Coliform-200 MPN/100ml. This research is under process, and more results could give further detail in near future. This research will help improve water quality of the Harlem River, improve environmental health and raise environmental awareness.SO tank Nutrient and bacterial levels of selected sites in the Harlem RiverCSO: Combined Sewer OverflowWWTP: Waste Water Treatment Plant

  20. Observed year-to-year sea surface salinity variability in the Bay of Bengal during the 2009–2014 period

    Digital Repository Service at National Institute of Oceanography (India)

    Chaitanya, A.V.S.; Durand, F.; Mathew, S.; Gopalakrishna, V.V.; Papa, F.; Lengaigne, M.; Vialard, J.; KranthiKumar, C.; Venkatesan, R.

    longer than the few months typical lifetime of interannual anomalies driven by Ganges-Brahmaputra river runoff in the model simulations of Durand et al. (2011). This motivated us to jointly consider all the possible freshwater forcing fluxes...

  1. Comparative assessment of the vulnerability and resilience of 10 deltas : work document

    NARCIS (Netherlands)

    Bucx, T.; Marchand, M.; Makaske, B.; Guchte, van de C.

    2010-01-01

    Background information about: Nile delta (Egypt), Incomati delta (Mozambique), Ganges-Brahmaputra-Meghna (Bangladesh), Yangtze (China), Ciliwung (Indonesia), Mekong (Vietnam), Rhine-Meuse (The Netherlands), Danube (Romania), California Bay-Delta, Mississippi River Delta (USA)

  2. Clinch River project: Sediment contaminants in the Lower Clinch River

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Sediment samples from three mainstem and seven tributary sites in the Clinch River Basin were analyzed for 21 organochlorine compounds, 19 metals, total volatile...

  3. Arctic River organic matter transport

    Science.gov (United States)

    Raymond, Peter; Gustafsson, Orjan; Vonk, Jorien; Spencer, Robert; McClelland, Jim

    2016-04-01

    Arctic Rivers have unique hydrology and biogeochemistry. They also have a large impact on the Arctic Ocean due to the large amount of riverine inflow and small ocean volume. With respect to organic matter, their influence is magnified by the large stores of soil carbon and distinct soil hydrology. Here we present a recap of what is known of Arctic River organic matter transport. We will present a summary of what is known of the ages and sources of Arctic River dissolved and particulate organic matter. We will also discuss the current status of what is known about changes in riverine organic matter export due to global change.

  4. Where rivers and oceans collide

    Science.gov (United States)

    Crockett, J. S.; Nittrouer, C. A.; Ogston, A. S.; Sternberg, R. W.; Driscoll, N. W.; Babcock, J.; Milliman, J. D.; Slingerland, R.; Naar, D. F.; Donahue, B.; Walsh, J. P.; Dietrich, W.; Parker, G.; Bera, M.; Davies, H.; Harris, P.; Goni, M.; Aller, R.; Aller, J.

    Fluvial sediment fills the coastal ocean, and sea level rise floods river valleys. This epic battle of terrestrial and marine processes occurs along all shorelines, and the complexities are especially well revealed in the Gulf of Papua, a foreland basin on the southern coast of New Guinea. Two hundred to four hundred million tons of sediment are supplied each year by the Fly and other rivers to a continental shelf that has been dissected by ancestors of these same rivers. The new sediment builds a large depositional feature known as a clinoform, which grows seaward and buries the record of earlier environments.

  5. Tasmania pushes western river developments

    Energy Technology Data Exchange (ETDEWEB)

    Scott, W.E.

    1978-07-01

    Tasmania is investigating the possibility of reducing its dependence on oil imports by developing power plants on the Gordon, King, and Franklin Rivers. Feasibility studies must plan for the inaccessibility caused by a harsh climate and rugged terrain where helicopter supply systems are required. A broad range of professional expertise is involved in the studies. Tasmania already has 22 hydroelectric stations, enough to meet present and expanding needs until the late 1980s. Two alternative plans have been devised for integrating the three rivers into the existing grid. Further construction on the Piemen River is also underway.

  6. 76 FR 23485 - Safety Zone; Red River

    Science.gov (United States)

    2011-04-27

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Red River AGENCY: Coast Guard, DHS. ACTION... Red River in the State of North Dakota, including those portions of the river bordered by Richland... protect persons and vessels from safety hazards associated with flooding occurring on the Red River....

  7. Theory and application of nonlinear river dynamics

    Institute of Scientific and Technical Information of China (English)

    Yu-chuan BAI; Zhao-yin WANG

    2014-01-01

    A theoretical model for river evolution including riverbed formation and meandering pattern formation is presented in this paper. Based on nonlinear mathematic theory, the nonlinear river dynamic theory is set up for river dynamic process. Its core content includes the stability and tropism characteristics of flow motion in river and river selves’ evolution. The stability of river dynamic process depends on the response of river selves to the external disturbance, if the disturbance and the resulting response will eventually attenuate, and the river dynamics process can be restored to new equilibrium state, the river dynamic process is known as stable;otherwise, the river dynamic process is unstable. The river dynamic process tropism refers to that the evolution tendency of river morphology after the disturbance. As an application of this theory, the dynamical stability of the constant curvature river bend is calculated for its coherent vortex disturbance and response. In addition, this paper discusses the nonlinear evolution of the river peristaltic process under a large-scale disturbance, showing the nonlinear tendency of river dynamic processes, such as river filtering and butterfly effect.

  8. Lowland river systems - processes, form and function

    DEFF Research Database (Denmark)

    Pedersen, M. L.; Kronvang, B.; Sand-Jensen, K.;

    2006-01-01

    Present day river valleys and rivers are not as dynamic and variable as they used to be. We will here describe the development and characteristics of rivers and their valleys and explain the background to the physical changes in river networks and channel forms from spring to the sea. We seek to ...

  9. Making rivers modular : emerging river science 1980-2005

    OpenAIRE

    Hemert, van, J.I.

    2008-01-01

    Conceptual, instrumentational and institutional dimensions of river science evolved interdependently between 1980 and 2005. The analysis is informed by an approach of science as cultural practice, co-production as the shaping and working of knowledge in society in terms of interdependent discursive, social and material orderings, and contextual history of science. River science then serves as a case to evaluate claims made in three diagnoses of recent science (mode 2 science, strategic scienc...

  10. The Scientific Challenges of Yellow River Study

    Institute of Scientific and Technical Information of China (English)

    Liu Xiaoyan; Sun Yangbo

    2005-01-01

    @@ The Yellow River is famous for its complex and unique physical conditions which give great challenges to the river management. Based on the study and analysis of the existing problems and research progress, this paper indicated that the most significant challenges of Yellow River studies are: long term hydrological and morphological changes; the optimized hydrology and sediment conditions to maintain the healthy life of the River; and simulation of Yellow River through mathematical model and physical models.

  11. Arkansas River Water Needs Assessment

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report is on the legal elements, hydrologic analysis, objectives, and water levels related to the Arkansas River and the management of it.

  12. Togiak River sportfishing studies, 1984

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Nearly three thousand angler days of effort was estimated to have been spent on the Togiak River in 1984. Effort was clearly dominated by the professional guiding...

  13. Upper Kenai River Cooperative Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Upper Kenai River Cooperative Plan is the product of a joint effort of the Chugach National Forest, Kenai National Wildlife Refuge, Alaska Division of Parks and...

  14. Umpqua River Oregon Geologic Floodplain

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Umpqua River drains 12,103 square kilometers (4,673 square miles) in southwest Oregon before flowing into the Pacific Ocean at Winchester Bay near the city of...

  15. Haw River sediment quality assessment

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report documents an evaluation of chemical contaminants in, and toxicity of, sediments collected from impoundments created by dams on the Haw River in Alamance...

  16. Riparian Habitat - San Joaquin River

    Data.gov (United States)

    California Department of Resources — The immediate focus of this study is to identify, describe and map the extent and diversity of riparian habitats found along the main stem of the San Joaquin River,...

  17. Mississippi River Valley alluvial aquifer

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set represents the extent of the Mississippi River Valley alluvial aquifer in the states of Missouri, Kentucky, Tennessee, Arkansas, Mississippi, and...

  18. St Louis River water quality

    Data.gov (United States)

    U.S. Environmental Protection Agency — St. Louis River Area of Concern surface water nutrient (TP, TN, NOx-N, NH4-N), dissolved oxygen, and particulate (TSS, chlorophyll a) concentration data from 2012...

  19. NARS Rivers and Streams Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — Data are from 1,000 river and stream sites across the conterminous US where consistent biological, chemical, physical and watershed data were gathered. The sites...

  20. Humboldt River main stem, Nevada

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set contains the main stem of the Humboldt River as defined by Humboldt Project personnel of the U.S. Geological Survey Nevada District, 2001. The data...

  1. River patterns and their meaning

    Science.gov (United States)

    Twidale, C. R.

    2004-10-01

    Rivers are largely responsible for shaping the Earth's continental landscapes. River patterns, the spatial arrangements of channels in the landscape, are determined by slope and structure. At site and sector scale, channel morphology varies spatially and in time, but river patterns and drainage texture, or the frequency of stream lines per unit area, together determine the intricacy, or otherwise, of topography. Most river patterns evolve through natural selection. Slope induces the formation of such patterns as parallel, radial and distributary, while structure produces straight, angular, trellis and annular arrangements. Once established, patterns tend to persist. Nevertheless, at many sites the usual patterns have been disturbed and patterns that are anomalous in terms of slope and structure have been produced by diversion, tectonism, volcanism, glaciation, mass movements, and human activities; by antecedence, superimposition, inheritance or underprinting; by the persistence of deeply eroding rivers which encounter alien structures; and by climatic change. River patterns provide clues to underlying structure and to the chronology of events. They have also proved significant in the search for minerals.

  2. Recent Record of the Neotropical River Otter (Lontra longicaudis) in the Choluteca River Tegucigalpa, Honduras

    OpenAIRE

    Francisco Aceituno; Carmen Nuñez; Francisco Aceituno1,Delmy Trochez2 andCarmen Nuñez3

    2015-01-01

    We report the presence of the Neotropical river otter (Lontra longicaudis) in the Choluteca River, Tegucigalpa, Honduras. To date the information is the second record verifiable of the species in the Choluteca River since one in the 1940s.

  3. Upper Yukon River, Alaska, a wild and scenic river analysis: Preliminary draft: Chapters IV and V

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Upper Yukon River, Alaska, possesses values which qualify it for inclusion in the National Wild and Scenic Rivers System. The Upper Yukon River and its...

  4. 77 FR 45653 - Yakima River Basin Conservation Advisory Group; Yakima River Basin Water Enhancement Project...

    Science.gov (United States)

    2012-08-01

    ... Bureau of Reclamation Yakima River Basin Conservation Advisory Group; Yakima River Basin Water... on the structure, implementation, and oversight of the Yakima River Basin Water Conservation Program... of the Water Conservation Program, including the applicable water conservation guidelines of...

  5. Ecosystem Services of Rivers: The Don River (Russian Federation) and the Roanoke River (USA)

    Science.gov (United States)

    The concept of ecosystem services recognizes the services, and benefits, provided to people by ecosystems. River systems provide many services to people, including freshwater provisioning, carbon storage, fisheries, recreation, transportation, and biodiversity. Here, we review th...

  6. Valley evolution by meandering rivers

    Science.gov (United States)

    Limaye, Ajay Brian Sanjay

    Fluvial systems form landscapes and sedimentary deposits with a rich hierarchy of structures that extend from grain- to valley scale. Large-scale pattern formation in fluvial systems is commonly attributed to forcing by external factors, including climate change, tectonic uplift, and sea-level change. Yet over geologic timescales, rivers may also develop large-scale erosional and depositional patterns that do not bear on environmental history. This dissertation uses a combination of numerical modeling and topographic analysis to identify and quantify patterns in river valleys that form as a consequence of river meandering alone, under constant external forcing. Chapter 2 identifies a numerical artifact in existing, grid-based models that represent the co-evolution of river channel migration and bank strength over geologic timescales. A new, vector-based technique for bank-material tracking is shown to improve predictions for the evolution of meander belts, floodplains, sedimentary deposits formed by aggrading channels, and bedrock river valleys, particularly when spatial contrasts in bank strength are strong. Chapters 3 and 4 apply this numerical technique to establishing valley topography formed by a vertically incising, meandering river subject to constant external forcing---which should serve as the null hypothesis for valley evolution. In Chapter 3, this scenario is shown to explain a variety of common bedrock river valley types and smaller-scale features within them---including entrenched channels, long-wavelength, arcuate scars in valley walls, and bedrock-cored river terraces. Chapter 4 describes the age and geometric statistics of river terraces formed by meandering with constant external forcing, and compares them to terraces in natural river valleys. The frequency of intrinsic terrace formation by meandering is shown to reflect a characteristic relief-generation timescale, and terrace length is identified as a key criterion for distinguishing these

  7. Analysis on River Sediment Changes of the Upper Reaches of Yangtze River

    Institute of Scientific and Technical Information of China (English)

    ZHONG Xiang-hao; SHI Guo-yu; XU Quan-xi; CHEN Ze-fang; LIU Shu-zhen

    2005-01-01

    The sediment load and river sedimentation of the upper reaches of Yangtze River has been undergoing constant changes as complex landform, large mountain area and plentiful precipitation make the drainage area of Yangtze River very vulnerable to water erosion and gravity erosion. Through analyzing the hydrological and sediment load statistics recorded by major hydrological stations along Yangtze River since 1950s, and editing the accumulation graph of annual runoff volume and annual sediment load, we find out that the suspended-sediment of Yangtze river has been decreasing year by year in Wulong Hydrological Station on Wujiang River, Beibei Hydrological Station on Jialingjiang River, Lijiawan Hydrological Station on Tuojiang River and Gaochang Hydrological Station on Minjiang River, Yichang Hydrological Station, Cuntan Hydrological Station along Yangtze River mainstream share the same experience too. But the statistics obtained at Pingshan Hydrological Station on Jinshajiang River shows the sediment load there has increased. Taking ecological construction, hydraulic engineering construction and precipitation changes into consideration, the thesis analyses the causes for the sediment load decrease of Jialingjiang River, Tuojiang River, Minjiang River and Wujiang River and provides us both scientific foundation for further study of river sediment changes of the upper reaches of Yangtze River, and measures to control river sedimentation.

  8. PRINCIPLES OF RIVER TRAINING AND MANAGEMENT

    Institute of Scientific and Technical Information of China (English)

    Zhaoyin WANG; Shimin TIAN; Yujun YI; Guoan YU

    2007-01-01

    River regulation and river training have been performed for various purposes and negative effects have been shown in numerous cases. In some cases the negative effects are so serious that humans have to consider to "renaturalize" the regulated rivers. Only by using the strategy of integrated river management the diverse river uses and natural fluvial processes and ecological systems may be harmonized. Based on analysis of case studies and data collected from literatures this paper presents the concept of integrated river management and four principles of river training. The integrated river management comprises: 1) taking the watershed, upper stream basin including the tributaries, middle and lower reaches and the estuary as an integrated entity in the planning, design and management; and 2) mitigating or controlling the negative impacts on hydrology, erosion and sedimentation, fluvial processes, land use and river use, environment and ecology while in achieving economic benefit from water resources development, flood safety management and hydropower exploitation. River training and management should be in accordance with the four principles: 1) extending the duration of river water flowing on the continent, which may be achieved by extending the river course or reducing the flow velocity; 2) controlling various patterns of erosions and reducing the sediment transportation in the rivers; 3) increasing the diversity of habitat and enhancing the connectivity between the river and riparian waters; and 4) restoring natural landscapes.

  9. Anthropogenic radionuclides in Ottawa River sediment near Chalk River Laboratories

    International Nuclear Information System (INIS)

    The Ottawa River has received nuclear reactor effluent from Chalk River Laboratories (CRL) for more than 60 years, including releases from a NRX accident in 1952. Recent interest in the potential impact of these historical releases and the possible need for remediation of a small region immediately downstream from the release point has led to comprehensive studies to assess risk to people and wildlife. In this paper, the results of an extensive survey of gamma-emitting anthropogenic radionuclides in Ottawa River sediment in the vicinity of CRL are presented. Anthropogenic radionuclides detected in Ottawa River sediment include 60Co, 94Nb, 137Cs, 152Eu, 154Eu, 155Eu and 241Am. Concentrations of all anthropogenic radionuclides decline rapidly with distance downstream of the process outfall, reaching stable concentrations about 2 km downstream. All of these radionuclides are found at some sites within 2 km upstream of the process outfall suggesting limited upstream transport and sedimentation. Comparison of anthropogenic radionuclides with several representative primordial radionuclides shows that with the exception of sites at the process outfall and within 2 km downstream of the process outfall, primordial radionuclide concentrations greatly exceed CRL derived anthropogenic radionuclide concentrations. Thus, over 60 years of radionuclide releases from operations at CRL have had little impact on radionuclide concentrations in Ottawa River sediment, except at a few sites immediately adjacent to the process outfall. (author)

  10. Flood trends and river engineering on the Mississippi River system

    Science.gov (United States)

    Pinter, N.; Jemberie, A.A.; Remo, J.W.F.; Heine, R.A.; Ickes, B.S.

    2008-01-01

    Along >4000 km of the Mississippi River system, we document that climate, land-use change, and river engineering have contributed to statistically significant increases in flooding over the past 100-150 years. Trends were tested using a database of >8 million hydrological measurements. A geospatial database of historical engineering construction was used to quantify the response of flood levels to each unit of engineering infrastructure. Significant climate- and/or land use-driven increases in flow were detected, but the largest and most pervasive contributors to increased flooding on the Mississippi River system were wing dikes and related navigational structures, followed by progressive levee construction. In the area of the 2008 Upper Mississippi flood, for example, about 2 m of the flood crest is linked to navigational and flood-control engineering. Systemwide, large increases in flood levels were documented at locations and at times of wing-dike and levee construction. Copyright 2008 by the American Geophysical Union.

  11. Tsunami Bores in Kitakami River

    Science.gov (United States)

    Tolkova, Elena; Tanaka, Hitoshi

    2016-07-01

    The 2011 Tohoku tsunami entered the Kitakami river and propagated there as a train of shock waves, recorded with a 1-min interval at water level stations at Fukuchi, Iino, and the weir 17.2 km from the mouth, where the bulk of the wave was reflected back. The records showed that each bore kept its shape and identity as it traveled a 10.9-km-path Fukuchi-Iino-weir-Iino. Shock handling based on the cross-river integrated classical shock conditions was applied to reconstruct the flow velocity time histories at the measurement sites, to estimate inflow into the river at each site, to evaluate the wave heights of incident and reflected tsunami bores near the weir, and to estimate propagation speed of the individual bores. Theoretical predictions are verified against the measurements. We discuss experiences of exercising the shock conditions with actual tsunami measurements in the Kitakami river, and test applicability of the shallow-water approximation for describing tsunami bores with heights ranging from 0.3 to 4 m in a river segment with a depth of 3-4 m.

  12. Nelson River and Hudson Bay

    Science.gov (United States)

    2002-01-01

    Rivers that empty into large bodies of water can have a significant impact on the thawing of nearshore winter ice. This true-color Moderate Resolution Imaging Spectroradiometer (MODIS) image from May 18, 2001, shows the Nelson River emptying spring runoff from the Manitoba province to the south into the southwestern corner of Canada's Hudson Bay. The warmer waters from more southern latitudes hasten melting of ice near the shore, though some still remained, perhaps because in shallow coastal waters, the ice could have been anchored to the bottom. High volumes of sediment in the runoff turned the inflow brown, and the rim of the retreating ice has taken on a dirty appearance even far to the east of the river's entrance into the Bay. The sediment would have further hastened the melting of the ice because its darker color would have absorbed more solar radiation than cleaner, whiter ice. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

  13. Radioactive effluents in Savannah River

    Energy Technology Data Exchange (ETDEWEB)

    Winn, W.G.

    1991-11-27

    During 1990, low-level radiometric studies of the Savannah River continued to distinguish between effluent contributions from Plant Vogtle and the Savannah River Site. Measurements of these radioactive effluents are of mutual interest to both institutions, as they can address disturbing trends before they become health and legal concerns. The Environmental Technology Section (ETS) has conducted radiometric studies of Plant Vogtle since late 1986, prior to its startup. The plant has two 1100 MWe pressurized water reactors developed by Westinghouse. Unit 1 started commercial operations in June 1987, and Unit 2 began in May 1989. During powered operations, ETS has routinely detected neutron-activated isotopes in controlled releases but all activities have been several orders of magnitude below the DOE guide values. In 1990, processing improvements for Vogtle effluents have yielded even lower activities in the river. The Vogtle release data and the ETS measurements have tracked well over the past four years.

  14. Grays River Watershed Geomorphic Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Geist, David R

    2005-04-30

    This investigation, completed for the Pacific Northwest National Laboratory (PNNL), is part of the Grays River Watershed and Biological Assessment commissioned by Bonneville Power Administration under project number 2003-013-00 to assess impacts on salmon habitat in the upper Grays River watershed and present recommendations for habitat improvement. This report presents the findings of the geomorphic assessment and is intended to support the overall PNNL project by evaluating the following: The effects of historical and current land use practices on erosion and sedimentation within the channel network The ways in which these effects have influenced the sediment budget of the upper watershed The resulting responses in the main stem Grays River upstream of State Highway 4 The past and future implications for salmon habitat.

  15. 50 CFR 226.205 - Critical habitat for Snake River sockeye salmon, Snake River fall chinook salmon, and Snake River...

    Science.gov (United States)

    2010-10-01

    ... in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies of the USGS publication and maps may be... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Critical habitat for Snake River sockeye salmon, Snake River fall chinook salmon, and Snake River spring/summer chinook salmon. 226.205...

  16. Terrestrial teleconnections link global rivers

    Science.gov (United States)

    O'Loughlin, F.; Howden, N. J.; Woods, R. A.; Bates, P. D.

    2013-12-01

    We present analyses of river discharge data from across the world, which we used to identify links between annual river flow regimes across different continents. Our hypothesis was that, as atmospheric processes are subject to large-scale teleconnection patterns, and because these atmospheric processes are inherently linked to precipitation regimes across the world, there should be identifiable links between river flow regimes driven by these atmospheric processes. We used discharge data from the Global Runoff Data Centre (GRDC) to identify cross-correlations (and accounted for serial dependence) between 23 of the world's largest river basins where overlapping data were available over a period of 12 years or more: two in South America; five in Africa; one in Australasia; five in North America and ten in Eurasia. The selected river basins drain approximately a third of the Earth's landmass at their furthest downstream gauging station. Where significant cross-correlations were found, we compared these to known patterns associated with the ENSO and NAO teleconnections. In total, 85 of the 253 possible correlations were deemed significant at p0). We compared these significant cross-correlations with known atmospheric teleconnection patterns, and while these were consistent for the majority of cases, we found a number of significant correlations that are inconsistent with the anticipated effects of known atmospheric teleconnections. Our results provide new insight into the inter-continental links between global river systems and the way in which these are controlled by large-scale atmospheric processes. We suggest this may be useful for global industries, such as insurers or aid agencies, who seek to understand correlations between the magnitudes of extreme events across different regions of the world. For the former, this may enable more efficient management of global liabilities, for the latter it may enable better logistical planning of disaster relief requirements

  17. River restoration - Malaysian/DID perspective

    International Nuclear Information System (INIS)

    Initially the river improvement works in Malaysia was weighted on flood control to convey a certain design flood with the lined and channelized rivers. But in late 2003 did has makes the approaches that conservation and improvement of natural function of river, i.e. river environment and eco-system should be incorporated inside the planning and design process. Generally, river restoration will focus on four approaches that will improve water quality, which is improving the quality of stormwater entering the river, maximizing the quantity of the urban river riparian corridor, stabilizing the riverbank, and improving the habitat within the river. This paper outlined the appropriate method of enhancing impairment of water quality from human activities effluent and others effluent. (Author)

  18. Russian River Ice Thickness and Duration

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set consists of river ice thickness measurements, and beginning and ending dates for river freeze-up events from fifty stations in northern Russia. The...

  19. Biological - Elwha River Dam Removal Study

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This study examines the ecosystem response of the Elwha River to the removal of the Elwha River dams. We will measure the following attributes of ecosystem...

  20. Global Lake and River Ice Phenology Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Global Lake and River Ice Phenology Database contains freeze and thaw/breakup dates as well as other descriptive ice cover data for 865 lakes and rivers in the...

  1. Sprague River Oregon Water circa 1870

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Sprague River drains 4090 square kilometers in south-central Oregon before flowing into the Williamson River and upper Klamath Lake. In cooperation with the...

  2. Sprague River Oregon Centerline North Fork 1968

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Sprague River drains 4090 square kilometers in south-central Oregon before flowing into the Williamson River and upper Klamath Lake. In cooperation with the...

  3. On the modelling of river delta formation

    NARCIS (Netherlands)

    Geleynse, N.

    2013-01-01

    This thesis presents approaches to the modelling of river delta formation. In particular, it provides results of numerical stratigraphic-morphodynamic modelling of river delta formation under various environmental forcings.

  4. Illinois River NWFR Habitat Management Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Illinois River National Wildlife and Fish Refuges Complex stretches along 124 miles of the Illinois River in west central Illinois. The Complex includes three...

  5. Yellow River Delta Faces a Historic Opportunity

    Institute of Scientific and Technical Information of China (English)

    Li Zhen

    2010-01-01

    @@ China's State Council has endorsed the Development Plan of an Efficient Eco-Economic Zone at Yellow River Delta. The plan is meant to create a more ecologically sustainable economic zone along the river delta.

  6. Yellow River Delta Faces a Historic Opportunity

    Institute of Scientific and Technical Information of China (English)

    Li Zhen

    2011-01-01

    @@ China's State Council has endorsed the Development Plan of an Efficient Eco-Economic Zone at Yellow River Delta.The plan is meant to create a more ecologically sustainable economic zone along the river delta.

  7. Geomorphic Analysis - Trinity River Restoration Potential

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The goal of the Trinity River project is to identify the potential positive effects of large-scale restoration actions in a 63 kilometer reach of the Trinity River...

  8. 2010 Hudson River Shallow Water Sediment Grabs

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Hudson River Shallow Water Mapping project characterizes the bottom of the Hudson River Estuary in shallow water (<3 m). The characterization includes...

  9. 2010 Hudson River Shallow Water Sediment Cores

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Hudson River Shallow Water Mapping project characterizes the bottom of the Hudson River Estuary in shallow water (<3 m). The characterization includes...

  10. Sprague River Oregon Centerline North Fork 1975

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Sprague River drains 4090 square kilometers in south-central Oregon before flowing into the Williamson River and upper Klamath Lake. In cooperation with the...

  11. Savannah River Site Environmental Implentation Plan

    International Nuclear Information System (INIS)

    This report describes the organizational responsibilities for the Savannah River Site Environmental program. Operations, Engineering and projects, Environment, safety, and health, Quality assurance, and the Savannah River Laboratory are described

  12. Sprague River Oregon Centerline Sycan 1940

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Sprague River drains 4090 square kilometers in south-central Oregon before flowing into the Williamson River and upper Klamath Lake. In cooperation with the...

  13. Sprague River Oregon Centerline North Fork 2000

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Sprague River drains 4090 square kilometers in south-central Oregon before flowing into the Williamson River and upper Klamath Lake. In cooperation with the...

  14. Chemical - Elwha River Dam Removal Study

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This study examines the ecosystem response of the Elwha River to the removal of the Elwha River dams. We will measure the following attributes of ecosystem...

  15. Physical - Elwha River Dam Removal Study

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This study examines the ecosystem response of the Elwha River to the removal of the Elwha River dams. We will measure the following attributes of ecosystem...

  16. Columbia River Impact Evaluation Plan

    International Nuclear Information System (INIS)

    A preliminary impact evaluation was conducted to assess the adequacy of existing data and proposed data collection programs for evaluating cumulative health and environmental impacts to the Columbia River due to past practices at the Hanford Site. The results of this evaluation were used to develop this plan to ensure collection of sufficient data for adequate characterization of the Columbia River along the 100 Area for CERCLA purposes. The evaluation used to develop the plan is not a risk assessment; the plan presented here is only a mechanism to collect additional data to support a future risk assessment

  17. 76 FR 22033 - Safety Zone; Red River Safety Zone, Red River, MN

    Science.gov (United States)

    2011-04-20

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AAOO Safety Zone; Red River Safety Zone, Red River, MN AGENCY... Safety Unit Duluth, MN is establishing a temporary safety zone on the Red River, MN. This safety zone is... entering all navigable waters of the Red River in the State of Minnesota north of a line drawn...

  18. ALWAYS A RIVER - SUPPLEMENTAL ENVIRONMENTAL EDUCATION CURRICULUM ON THE OHIO RIVER AND WATER GRADES K - 12

    Science.gov (United States)

    This curriculum was developed as a significant component of the project, Always a River: The Ohio River and the American Experience, a six-state collaboration devoted to exploring the historical and cultural development of the Ohio River. The Always a River project is being joint...

  19. Arctic River Mobility: A Baseline Assessment

    Science.gov (United States)

    Rowland, J. C.; Wilson, C. J.; Brumby, S. P.; Pope, P. A.

    2009-12-01

    In many arctic river systems, permafrost and the presence of frozen floodplain materials provides a significant source of bank cohesion. Due to this cohesion, permafrost may play an important control of arctic river mobility and meandering dynamics. Whether changes in the rates of permafrost thawing has had or will have as significant a geomorphic impact on arctic river meandering as has already been observed for arctic coastline retreat, lake size and distribution, and hillslope stability is at present an unanswered question. The potential impact of climate driven changes in arctic river meandering has important implications for river planform morphology, floodplain dynamics, river ecology, and the export of carbon and nutrients to coastal oceans. We present results of remote sensing analysis of river mobility for the Yukon River in Alaska and sections of the Siberian Rivers including the Lena, the Kolyma and the Indigirka Rivers. Comparisons of river location at successive intervals in time were conducted using Landsat imagery archives and higher resolution aerial photographs and satellite imagery. Extraction of river channel locations was accomplished using the GeniePro automated feature extraction software. Over the period of Landsat coverage (mid-1980s to present) arctic rivers show limited to no movement at the resolution of the Landsat data (30 m per pixel). On the Yukon Flats regions of the Yukon River, the most mobile sections of the river have migration rates comparable to reach-average values reported for temperate rivers; given that large portions of the Yukon display no detectable movement, reach-averaged values are far less than observed in temperate systems. Field inspection of areas of high erosion along the Yukon River indicate that erosional processes associated with the thermal degradation of permafrost play a dominant role in many of these areas. Thermal niching and large scale bank collapse due to undercutting play a large role in bank erosion

  20. Rivers Run Through It: Discovering the Interior Columbia River Basin.

    Science.gov (United States)

    Davis, Shelley; Wojtanik, Brenda Lincoln; Rieben, Elizabeth

    1998-01-01

    Explores the Columbia River Basin, its ecosystems, and challenges faced by natural resource managers. By studying the basin's complexity, students can learn about common scientific concepts such as the power of water and effects of rain shadows. Students can also explore social-scientific issues such as conflicts between protecting salmon runs and…

  1. Making rivers modular : emerging river science 1980-2005

    NARCIS (Netherlands)

    Hemert, van Annemieke Jacqueline

    2008-01-01

    Conceptual, instrumentational and institutional dimensions of river science evolved interdependently between 1980 and 2005. The analysis is informed by an approach of science as cultural practice, co-production as the shaping and working of knowledge in society in terms of interdependent discursive,

  2. Setting targets in strategies for river restoration

    OpenAIRE

    Pedroli, B.; De Blust, Geert; Van Looy, Kris; Rooij, S. van

    2006-01-01

    Since about 90% of the natural floodplain area of rivers in Europe has been reclaimed and now lacks river dynamics, nature rehabilitation along rivers is of crucial importance for the restoration of their natural function. Flood protection, self-purification of surface water, groundwater recharge, species protection and migration are all involved in this process. It is now generally recognised that rivers form natural arteries in Europe but are also of economic importance and are recognisable...

  3. Columbia River Component Data Evaluation Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    C.S. Cearlock

    2006-08-02

    The purpose of the Columbia River Component Data Compilation and Evaluation task was to compile, review, and evaluate existing information for constituents that may have been released to the Columbia River due to Hanford Site operations. Through this effort an extensive compilation of information pertaining to Hanford Site-related contaminants released to the Columbia River has been completed for almost 965 km of the river.

  4. Economics of Yams Production in Rivers State

    OpenAIRE

    Esor, Prince. B; Okidim, I. A

    2015-01-01

    This research work was on the economics of yam production in Rivers State. The objectives of the study were: estimating the production function of yam in Rivers State using cob-Douglas production, determining the marginal physical product (mpp) of labour and capital, determine the optimum level of inputs required for attaining the optimum in yam production in Rivers State and determining the marginal Rate of Technical substitution (MRTS) of labour for capital in Rivers State. Methodology: Ana...

  5. RiverCare: towards self-sustaining multifunctional rivers

    Science.gov (United States)

    Augustijn, Denie; Schielen, Ralph; Hulscher, Suzanne

    2014-05-01

    Rivers are inherently dynamic water systems involving complex interactions among hydrodynamics, morphology and ecology. In many deltas around the world lowland rivers are intensively managed to meet objectives like safety, navigation, hydropower and water supply. With the increasing pressure of growing population and climate change it will become even more challenging to reach or maintain these objectives and probably also more demanding from a management point of view. In the meantime there is a growing awareness that rivers are natural systems and that, rather than further regulation works, the dynamic natural processes should be better utilized (or restored) to reach the multifunctional objectives. Currently many integrated river management projects are initiated all over the world, in large rivers as well as streams. Examples of large scale projects in the Netherlands are 'Room for the River' (Rhine), the 'Maaswerken' (Meuse), the Deltaprogramme and projects originating from the European Water Framework Directive (WFD). These projects include innovative measures executed never before on this scale and include for example longitudinal training dams, side channels, removal of bank protection, remeandering of streams, dredging/nourishment and floodplain rehabilitation. Although estimates have been made on the effects of these measures for many of the individual projects, the overall effects on the various management objectives remains uncertain, especially if all projects are considered in connection. For all stakeholders with vested interests in the river system it is important to know how that system evolves at intermediate and longer time scales (10 to 100 years) and what the consequences will be for the various river functions. If the total, integrated response of the system can be predicted, the system may be managed in a more effective way, making optimum use of natural processes. In this way, maintenance costs may be reduced, the system remains more natural

  6. River enhancement in the Upper Mississippi River basin: Approaches based on river uses, alterations, and management agencies

    Science.gov (United States)

    O'Donnell, T. K.; Galat, D.L.

    2007-01-01

    The Upper Mississippi River is characterized by a series of locks and dams, shallow impoundments, and thousands of river channelization structures that facilitate commercial navigation between Minneapolis, Minnesota, and Cairo, Illinois. Agriculture and urban development over the past 200 years have degraded water quality and increased the rate of sediment and nutrient delivery to surface waters. River enhancement has become an important management tool employed to address causes and effects of surface water degradation and river modification in the Upper Mississippi River Basin. We report information on individual river enhancement projects and contrast project densities, goals, activities, monitoring, and cost between commercially non-navigated and navigated rivers (Non-navigated and Navigated Rivers, respectively). The total number of river enhancement projects collected during this effort was 62,108. Cost of all projects reporting spending between 1972 and 2006 was about US$1.6 billion. Water quality management was the most cited project goal within the basin. Other important goals in Navigated Rivers included in-stream habitat improvement and flow modification. Most projects collected for Non-navigated Rivers and their watersheds originated from the U.S. Department of Agriculture (USDA). The U.S. Army Corps of Engineers and the USDA were important sources for projects in Navigated Rivers. Collaborative efforts between agencies that implement projects in Non-navigated and Navigated Rivers may be needed to more effectively address river impairment. However, the current state of data sources tracking river enhancement projects deters efficient and broad-scale integration. ?? Journal compilation ?? 2007 Society for Ecological Restoration International.

  7. 33 CFR 117.189 - Sacramento River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Sacramento River. 117.189 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements California § 117.189 Sacramento River. (a) The draws of each bridge from Isleton to American River junction shall open on signal from May 1...

  8. 33 CFR 117.175 - Mokelumne River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Mokelumne River. 117.175 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements California § 117.175 Mokelumne River. (a) The draw of the California Department of Transportation highway bridge, the Mokelumne River Bridge, mile 3.0,...

  9. 33 CFR 117.547 - Bush River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Bush River. 117.547 Section 117... OPERATION REGULATIONS Specific Requirements Maryland § 117.547 Bush River. The draw of the Amtrak bridge... Superintendent at 301-291-4278 by an authorized representative of the Bush River Yacht Club by noon on the...

  10. 33 CFR 117.359 - Chattahoochee River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Chattahoochee River. 117.359... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Georgia § 117.359 Chattahoochee River. See § 117.107, Chattahoochee River, listed under Alabama....

  11. 33 CFR 117.337 - Trout River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Trout River. 117.337 Section 117... OPERATION REGULATIONS Specific Requirements Florida § 117.337 Trout River. The draw of the CSX Railroad Bridge across the Trout River, mile 0.9 at Jacksonville, operates as follows: (a) The bridge is...

  12. 33 CFR 117.299 - Loxahatchee River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Loxahatchee River. 117.299... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.299 Loxahatchee River. The draw of the Florida East Coast Railway bridge across the Loxahatchee River, mile 1.2 at Jupiter, operates as...

  13. 33 CFR 117.291 - Hillsborough River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Hillsborough River. 117.291... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.291 Hillsborough River. (a) The... the CSX Railroad Bridge across the Hillsborough River, mile 0.7, at Tampa, operates as follows:...

  14. 33 CFR 117.258 - Apalachicola River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Apalachicola River. 117.258... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.258 Apalachicola River. The draw of the CSX Railroad bridge, mile 105.9, at River Junction shall open on signal Monday through Friday from 8...

  15. 33 CFR 117.391 - Chicago River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Chicago River. 117.391 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Illinois § 117.391 Chicago River. The draws of the bridges operated by the City of Chicago over the Main Branch of Chicago River, the bridges on the...

  16. 33 CFR 117.593 - Chelsea River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Chelsea River. 117.593 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Massachusetts § 117.593 Chelsea River. All drawbridges across the Chelsea River shall open on signal. The opening signal for each drawbridge is two...

  17. 33 CFR 117.531 - Piscataqua River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Piscataqua River. 117.531 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maine § 117.531 Piscataqua River. (a) The following requirements apply to all bridges across the Piscataqua River: (1) Public vessels of the United...

  18. 33 CFR 117.411 - Missouri River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Missouri River. 117.411 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Kansas § 117.411 Missouri River. The draws of the bridges across the Missouri River shall open on signal; except during the winter season between the...

  19. 33 CFR 117.407 - Missouri River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Missouri River. 117.407 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Iowa § 117.407 Missouri River. See § 117.691, Missouri River listed under Nebraska. Kansas...

  20. 33 CFR 117.333 - Suwannee River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Suwannee River. 117.333 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.333 Suwannee River. The draw of Suwannee River bridge, mile 35 at Old Town need not be opened for the passage of vessels, however, the draw...

  1. 33 CFR 117.397 - Wabash River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Wabash River. 117.397 Section 117... OPERATION REGULATIONS Specific Requirements Illinois § 117.397 Wabash River. The draws of the bridges across the Wabash River need not be opened for the passage of vessels. Indiana...

  2. 33 CFR 117.183 - Old River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Old River. 117.183 Section 117... OPERATION REGULATIONS Specific Requirements California § 117.183 Old River. The draw of the California... notice is given to the drawtender at the Rio Vista bridge across the Sacramento River, mile 12.8....

  3. 33 CFR 117.570 - Sassafras River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Sassafras River. 117.570 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.570 Sassafras River. The draw of the Sassafras River (Route 213) bridge, mile 10.0 at Georgetown, Maryland, shall open on signal; except...

  4. 33 CFR 117.171 - Middle River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Middle River. 117.171 Section 117... OPERATION REGULATIONS Specific Requirements California § 117.171 Middle River. (a) The draw of the San..., mile 9.8 near Middle River Station, shall open on signal if at least 12 hours notice is given to...

  5. 33 CFR 117.424 - Belle River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Belle River. 117.424 Section 117... OPERATION REGULATIONS Specific Requirements Louisiana § 117.424 Belle River. The draw of the S70 bridge, mile 23.8 (Landside Route) near Belle River, shall open on signal; except that, from 10 p.m. to 6...

  6. 33 CFR 117.1058 - Snake River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Snake River. 117.1058 Section 117... OPERATION REGULATIONS Specific Requirements Washington § 117.1058 Snake River. (a) The draw of the Burlington Northern Santa Fe railroad bridge across the Snake River at mile 1.5 between Pasco and Burbank...

  7. River as a part of ground battlefield

    Science.gov (United States)

    Vračar, Miodrag S.; Pokrajac, Ivan; Okiljević, Predrag

    2013-05-01

    The rivers are in some circumstances part of the ground battlefield. Microseisms induced at the riverbed or ground at the river surrounding might be consequence of military activities (military ground transports, explosions, troop's activities, etc). Vibrations of those fluid-solid structures are modeled in terms of solid displacement and change of fluid pressure. This time varying fluid pressure in river, which originates from ground microseisms, is possible to detect with hydrophones. Therefore, hydroacoustic measurements in rivers enables detecting, identification and localization various types of military noisy activities at the ground as and those, which origin is in the river water (hydrodynamics of water flow, wind, waves, river vessels, etc). In this paper are presented river ambient noise measurements of the three great rivers: the Danube, the Sava and the Tisa, which flows in north part of Serbia in purpose to establish limits in detection of the ground vibrations in relatively wide frequency range from zero to 20 kHz. To confirm statement that the river is a part of ground battlefield, and that hydroacoustic noise is possible to use in detecting and analyzing ground microseisms induced by civil or military activities, some previous collected data of hydroacoustic noise measurement in the rivers are used. The data of the river ambient noise include noise induced by civil engineering activities, that ordinary take place in large cities, noise that produced ships and ambient noise of the river when human activities are significantly reduced. The poly spectral method was used in analysis such events.

  8. Lynne Cherry's "A River Ran Wild."

    Science.gov (United States)

    Ledford, Carolyn; Brent, Rebecca

    1997-01-01

    Paraphrases the book "A River Ran Wild" by Lynne Cherry, contrasts how Native American and European settlers use a river, and discusses the pollution and cleanup of the river. Provides classroom discussion questions, and individual or group activities in language arts, art, role-playing, geography, and interviewing. Includes an annotated…

  9. 33 CFR 117.300 - Manatee River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Manatee River. 117.300 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.300 Manatee River. The draw of the CSX Railroad Bridge across the Manatee River, mile 4.5 Bradenton, operates as follows: (a) The bridge is...

  10. The science and practice of river restoration

    Science.gov (United States)

    Wohl, Ellen; Lane, Stuart N.; Wilcox, Andrew C.

    2015-08-01

    River restoration is one of the most prominent areas of applied water-resources science. From an initial focus on enhancing fish habitat or river appearance, primarily through structural modification of channel form, restoration has expanded to incorporate a wide variety of management activities designed to enhance river process and form. Restoration is conducted on headwater streams, large lowland rivers, and entire river networks in urban, agricultural, and less intensively human-altered environments. We critically examine how contemporary practitioners approach river restoration and challenges for implementing restoration, which include clearly identified objectives, holistic understanding of rivers as ecosystems, and the role of restoration as a social process. We also examine challenges for scientific understanding in river restoration. These include: how physical complexity supports biogeochemical function, stream metabolism, and stream ecosystem productivity; characterizing response curves of different river components; understanding sediment dynamics; and increasing appreciation of the importance of incorporating climate change considerations and resiliency into restoration planning. Finally, we examine changes in river restoration within the past decade, such as increasing use of stream mitigation banking; development of new tools and technologies; different types of process-based restoration; growing recognition of the importance of biological-physical feedbacks in rivers; increasing expectations of water quality improvements from restoration; and more effective communication between practitioners and river scientists.

  11. Setting targets in strategies for river restoration

    NARCIS (Netherlands)

    Pedroli, G.B.M.; Blust, de G.; Looy, van K.; Rooij, van S.A.M.

    2002-01-01

    Since about 90% of the natural floodplain area of rivers in Europe has been reclaimed and now lacks river dynamics, nature rehabilitation along rivers is of crucial importance for the restoration of their natural function. Flood protection, self-purification of surface water, groundwater recharge, s

  12. A Review of Integrated River Basin Management for Sarawak River

    Directory of Open Access Journals (Sweden)

    Kuok K. Kuok

    2011-01-01

    Full Text Available Problem statement: Sarawak River was a life-sustaining water source for the residents in Kuching City and surrounding areas. Raw water is treated at Batu Kitang Water Treatment Plant (BKWTP that supplies more than 98% of the total water production in Kuching City. The raw water supply to BKWTP is not adequate to meet the ever increasing water demand. In order to overcome this problem, four projects had been implemented along Sarawak River for managing and securing water supply to BKWTP. Approach: These four projects are construction of 1.5m height storage weir across Sungai Sarawak Kiri river channel, Kuching Barrage and Shiplock, Bengoh Dam and Kuching Centralized Wastewater Management System (KCWMS. In 2005, 1.5 m height submersible weir was constructed across Sungai Sarawak Kiri channel for increasing the safe yield that can last until year 2010. Kuching Barrage and Shiplock were commissioned in 2000 as barrier to avoid the saline intrusion reaching upper catchment. 24 telemetry stations were installed along Sarawak River for monitoring and regulating the water level. This will preserve high quality water storage at upper catchment of Sarawak River. In year 2010, Bengoh Dam was constructed to ensure adequate raw water will be supplied to BKWTP for meeting the increasing water demand from 2010-2030. This reservoir will store 144 million m3 of fresh water covering reservoir area of 8.77km2. Beyond 2030, the water supply shall not depend solely on fresh water. Results: Black and grey water in Sarawak Catchment was treated through Kuching Centralized Wastewater Management System (KCWMS and recycled for daily used. Conclusion: The treated water that comply Standard A water quality, can distribute for domestic, industrial and irrigation used in nearest future. This will reduce the water demand solely on raw water and create a sustainable living in Kuching City. Beyond 2030, a few alternatives are also proposed for conserving and

  13. Assessment of River Habitat Quality in the Hai River Basin, Northern China

    OpenAIRE

    Yuekui Ding; Baoqing Shan; Yu Zhao

    2015-01-01

    We applied a river habitat quality (RHQ) assessment method to the Hai River Basin (HRB); an important economic centre in China; to obtain baseline information for water quality improvement; river rehabilitation; and watershed management. The results of the assessment showed that the river habitat in the HRB is seriously degraded. Specifically; 42.41% of the sites; accounting for a river length of 3.31 × 104 km; were designated poor and bad. Habitat in the plain areas is seriously deteriorated...

  14. Multi-National River Basin Cooperation and Management Case Study: Senegal River Basin

    OpenAIRE

    Ayaa, Patricia

    2012-01-01

    With increasing populations, urbanization and thus increasing demand for water, conflict on International River basins has been increasing over the years which has necessitated formation of International River frameworks to devise means of cooperation among the countries sharing the river basins. The main modes of cooperation in international river basins include allocating the waters of the river to the sharing countries such that each country manages its own water resources, or treating the...

  15. Eutrophication of lakes and rivers

    Science.gov (United States)

    Eutrophication is an ecological process, akin to aging, in which a water body is increasingly enriched with organic matter. While the most obvious signs of eutrophication in lakes and rivers involve algal blooms and fish kills, the systemic of eutrophication, although profound, are often not as noti...

  16. Phytoplankton of the Tisa River

    OpenAIRE

    Ržaničanin Ana M.; Cvijan Mirko V.; Krizmanić Jelena

    2005-01-01

    Investigation of the Tisa River phytoplankton community was carried out directly after the cyanide spill in 2000. The investigation took place near Bečej from February of 2000 to January of 2001. We observed 374 taxa from eight algal divisions. The highest biodiversity was recorded among the divisions Chlorophyta and Bacillariophyta.

  17. Phytoplankton of the Tisa River

    Directory of Open Access Journals (Sweden)

    Ržaničanin Ana M.

    2005-01-01

    Full Text Available Investigation of the Tisa River phytoplankton community was carried out directly after the cyanide spill in 2000. The investigation took place near Bečej from February of 2000 to January of 2001. We observed 374 taxa from eight algal divisions. The highest biodiversity was recorded among the divisions Chlorophyta and Bacillariophyta.

  18. Stochastic modelling of river morphodynamics

    NARCIS (Netherlands)

    Van Vuren, B.G.

    2005-01-01

    Modern river management has to reconcile a number of functions, such as protection against floods and provision of safe and efficient navigation, floodplain agriculture, ecology and recreation. Knowledge on uncertainty in fluvial processes is important to make this possible, to design effective rive

  19. River water quality modelling: II

    DEFF Research Database (Denmark)

    Shanahan, P.; Henze, Mogens; Koncsos, L.;

    1998-01-01

    The U.S. EPA QUAL2E model is currently the standard for river water quality modelling. While QUAL2E is adequate for the regulatory situation for which it was developed (the U.S. wasteload allocation process), there is a need for a more comprehensive framework for research and teaching. Moreover...

  20. HANFORD SITE RIVER CORRIDOR CLEANUP

    International Nuclear Information System (INIS)

    In 2005, the US Department of Energy (DOE) launched the third generation of closure contracts, including the River Corridor Closure (RCC) Contract at Hanford. Over the past decade, significant progress has been made on cleaning up the river shore that bordes Hanford. However, the most important cleanup challenges lie ahead. In March 2005, DOE awarded the Hanford River Corridor Closure Contract to Washington Closure Hanford (WCH), a limited liability company owned by Washington Group International, Bechtel National and CH2M HILL. It is a single-purpose company whose goal is to safely and efficiently accelerate cleanup in the 544 km2 Hanford river corridor and reduce or eliminate future obligations to DOE for maintaining long-term stewardship over the site. The RCC Contract is a cost-plus-incentive-fee closure contract, which incentivizes the contractor to reduce cost and accelerate the schedule. At $1.9 billion and seven years, WCH has accelerated cleaning up Hanford's river corridor significantly compared to the $3.2 billion and 10 years originally estimated by the US Army Corps of Engineers. Predictable funding is one of the key features of the new contract, with funding set by contract at $183 million in fiscal year (FY) 2006 and peaking at $387 million in FY2012. Another feature of the contract allows for Washington Closure to perform up to 40% of the value of the contract and subcontract the balance. One of the major challenges in the next few years will be to identify and qualify sufficient subcontractors to meet the goal

  1. Health evaluation indicator system for urban landscape rivers, case study of the Bailianjing River in Shanghai

    Science.gov (United States)

    Wang, Juan; Wang, Yue; Yang, Haizhen; Lu, Zhibo; Xu, Xiaotian

    2010-11-01

    The River Bailianjing is an iconic landscape feature known to all residents in Pudong area and running through the Shanghai Expo 2010 Park. The river and its basin was a complex living ecosystem which supports a unique variety of flora and fauna several decades ago. However, as a result of unsuccessful pollution source control, sewage and first flow of the storm water is directly coming into the river in some catchment. The water quality of the river is seriously organically polluted now. The typical organic pollutants are COD, NH3-N, TN and TP, which cause the extinction of the water plants and aquatic. Furthermore, the artificial hard river banks isolate the river course and the land, which damaged the whole ecological system totally. The nature of the River Bailianjing and its history has resulted in many government departments and authorities and non government organizations having jurisdiction and/or an interest in the river's management. As a new tool to improve river management, the river health assessment has become the major focus of ecological and environmental science. Consequently, research on river health evaluation and its development on river management are of great theoretical and practical significance. In order to evaluate the healthy status of the River Bailianjing and prepare comprehensive scientific background data for the integrated river ecological rehabilitation planning, the health evaluation indicator system for River Bailianjing is brought forward. The indicator system has three levels: the first is target layer; the second is criteria layer, including five fields: water quality characteristics, hydrology characteristics, river morphology, biological characteristics and river scenic beauty; the third is an index layer, a total of 15 specific indicators included. Fuzzy AHP method is used to evaluate the target river's health status, and five grades are set up to describe it: healthy, sub health, marginal, unhealthy and pathological. The

  2. Research on the river function regionalization

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Objectives, principles, classification system, zoning method and procedure of river function region-alization were investigated systematically based on the present status of modern river regulation and function requirement. Considering the ecosystem continuity and river function integrality, a river is suggested to be divided into five function zones: ecological protection zone, habitat restoration zone, exploitation and utilization zone, buffer zone,and transition zone, based on the developed intensity and the function characteristics of the river. In this paper, not only the five function zones were described qualitatively, but also the quantitative examination method on how to identify their function zone types was given. A double-criterion partitioning scheme was proposed according to the functional zoning diagram constructed by the evaluation of the social and ecological function of rivers. Finally, the procedures of river function regionalization were shown.

  3. Object-oriented river system simulation

    International Nuclear Information System (INIS)

    This paper describes an object-oriented approach to river basin simulation modeling that is event driven rather than time driven as are most river system simulation models. At the heart of this method are autonomous software objects which replicate the physical behavior of the components of an actual river system (Colorado River). These objects react to stimuli (changing values of their inputs, outputs or state) in much the same way as do the analogous components of the actual river. The simulation of river systems is the result of the coordinated actions, in any order, of the various objects representing the entities within the system. An object-oriented approach to modeling a river has a number of characteristics that make it worthy of consideration. The model's architecture makes it especially suited to graphic user interfaces and database operations. It allows the easy integration of artificial intelligence techniques that can aid in expressing complex policies governing system operation

  4. Elwha River Restoration: Sediment Management

    Science.gov (United States)

    Kimbrel, S.; Bountry, J.; Randle, T. J.; Ritchie, A.; Huginin, H.; Torrance, A.

    2013-12-01

    The removal of Elwha and Glines Canyon Dams on the Elwha River relies on controlled reservoir drawdown increments and natural river flows to erode and redistribute the reservoir sediment, estimated to be a total of 23 (× 3) million m3. To mitigate for the predicted sediment effects, facilities have been constructed for water quality and flood protection. A sediment monitoring program is being implemented by an interdisciplinary team from Reclamation and National Park Service to integrate real-time measurements with continually updated numerical model predictions. The most recent numerical reservoir modeling and monitoring results indicate about 20 to 25 percent of the reservoir sediment has been released since the start of dam removal. Monitoring results in 2012 and early 2013 confirmed that controlled reservoir drawdown increments have induced sufficient vertical and lateral erosion of delta surfaces behind both dams. Predam channel and floodplain surface has been exposed in numerous portions of Lake Aldwell, with the release of coarse and fine sediment in the first few pools below Elwha Dam. The material released from Lake Aldwell has included organic material. With the removal of about three quarters of Glines Canyon Dam and the disappearance of Lake Mills, coarse bedload sediment has been continually released into the downstream river since late fall 2012. Field measurements and numerical modeling are being used to track the progression of the sediment wave downstream to the Elwha River mouth. Initial findings are that the aggradation was greatest immediately downstream of Glines Canyon Dam, and filled pools and transformed river planform from step-pool to glide for most of the 7 mile reach between Lake Mills and Lake Aldwell. Although there has not been a major flood, winter flows and spring snowmelt have significantly reworked the released sediment and remnants of the pre-sediment release pools and rapids have re-emerged. Large wood and organics have also

  5. Constructing river stage-discharge rating curves using remotely sensed river cross-sectional inundation areas and river bathymetry

    Science.gov (United States)

    Pan, Feifei; Wang, Cheng; Xi, Xiaohuan

    2016-09-01

    Remote sensing from satellites and airborne platforms provides valuable data for monitoring and gauging river discharge. One effective approach first estimates river stage from satellite-measured inundation area based on the inundation area-river stage relationship (IARSR), and then the estimated river stage is used to compute river discharge based on the stage-discharge rating (SDR) curve. However, this approach is difficult to implement because of a lack of data for constructing the SDR curves. This study proposes a new method to construct the SDR curves using remotely sensed river cross-sectional inundation areas and river bathymetry. The proposed method was tested over a river reach between two USGS gauging stations, i.e., Kingston Mines (KM) and Copperas Creek (CC) along the Illinois River. First a polygon over each of two cross sections was defined. A complete IARSR curve was constructed inside each polygon using digital elevation model (DEM) and river bathymetric data. The constructed IARSR curves were then used to estimate 47 river water surface elevations at each cross section based on 47 river inundation areas estimated from Landsat TM images collected during 1994-2002. The estimated water surface elevations were substituted into an objective function formed by the Bernoulli equation of gradually varied open channel flow. A nonlinear global optimization scheme was applied to solve the Manning's coefficient through minimizing the objective function value. Finally the SDR curve was constructed at the KM site using the solved Manning's coefficient, channel cross sectional geometry and the Manning's equation, and employed to estimate river discharges. The root mean square error (RMSE) in the estimated river discharges against the USGS measured river discharges is 112.4 m3/s. To consider the variation of the Manning's coefficient in the vertical direction, this study also suggested a power-law function to describe the vertical decline of the Manning

  6. Large-scale river regulation

    International Nuclear Information System (INIS)

    Recent concern over human impacts on the environment has tended to focus on climatic change, desertification, destruction of tropical rain forests, and pollution. Yet large-scale water projects such as dams, reservoirs, and inter-basin transfers are among the most dramatic and extensive ways in which our environment has been, and continues to be, transformed by human action. Water running to the sea is perceived as a lost resource, floods are viewed as major hazards, and wetlands are seen as wastelands. River regulation, involving the redistribution of water in time and space, is a key concept in socio-economic development. To achieve water and food security, to develop drylands, and to prevent desertification and drought are primary aims for many countries. A second key concept is ecological sustainability. Yet the ecology of rivers and their floodplains is dependent on the natural hydrological regime, and its related biochemical and geomorphological dynamics. (Author)

  7. Modeling Water Quality in Rivers

    Directory of Open Access Journals (Sweden)

    Liren Yu

    2005-01-01

    Full Text Available This study reports a PC software, used in a Windows-based environment, which was developed based on the first order reaction of Biological Oxygen Demand (BOD and a modified Streeter and Phelps equation, in order to simulate and determine the variations of Dissolved Oxygen (DO and of the BOD along with the studied river reaches. The software considers many impacts of environmental factors, such as the different type of discharges (concentrated or punctual source, tributary contribution, distributed source, nitrogenous BOD, BOD sedimentation, photosynthetic production and benthic demand of oxygen, and so on. The software has been used to model the DO profile along one river, with the aim to improve the water quality through suitable engineering measure.

  8. Capability and quality assessment of rice growing hydric soils in majuli river island, assam, India

    OpenAIRE

    Bhaskara Phaneendra Bhaskar; Dipak Sarkar

    2013-01-01

    The  wetland soils in  majuli island is a unique in maintaining rice ecology and geoenvironment in Brahmaputra valley of Assam  due to increasing  rate of  bankline erosion in southern bank  and expansion of channel bars on northern banks. These hydric soils in the subgroups of aquents and aquepts are  saturated throughout year as assessed from depleted matrix with hue 10YR, 2.5Y and 5Y, chroma less than 2, stratified textures, neutral to slightly alkaline reaction, low cation exchange capaci...

  9. DYNAMIC RESOURCES OF RIVER SEDIMENTS

    Institute of Scientific and Technical Information of China (English)

    George GERGOV; Tzviatka KARAGIOZOVA

    2005-01-01

    The currently enforced Bulgarian water legislation [the Water Act (1999),the Environmental Protection Act (2002),etc.] requires conducting special studies for accurate assessments of sand and gravel flux along the rivers,prior to the issue of the license for operation of the quarries,where they will be dredged. The activity of a quarry necessitates special investigations because of the large dimensions of the damages inflicted on the environment. Ours studies have shown that there are two types of river reaches,in which abstracion of sand and gravel is performed. The first one refers usually to the plain area river reaches. The other type is mountainous with high rate of sediment load,which consists of coarse solid matter. The "on-the-spot" study on the environmental impact of the sand and gravel dredging has revealed that in the area of the quarry the riverbed cuts into the alluvial sediments to about 6-7 m and this ditch has spread by attenuation at a distance of more than 25 km upstream. Downstream the pit the picture is replicated and at the 8th km a local scour on the riverbed,amounting to more than 1.80 - 2.00 m,has been measured near the foundation of a massive bridge in the centre of city of Plovdiv. Such assessments of dynamic resources of sand and gravel materials are expected to serve for the purposes of gradual limitation of this activity in river sections close to renewable resources. The amount of sediment load,which may be abstracted in the area of the Orizare quarry in Bulgaria on a yearly basis has been calculated as 6000 m3/a. It ensures that the resources will not be exhausted and irreversible distortion of the riverbed will be prevented. This is an environmentally safe limit.

  10. Relationship to the River: The Case of the Muar River Community

    Directory of Open Access Journals (Sweden)

    Bahaman A. Samah

    2011-01-01

    Full Text Available Problem statement: Muar River which located in Johor, is an important river in Malaysia. Previously Muar River had a huge influence on the socio-economic status of the community. It has been used as the sources of income, protein and as well as the major mode of transportation for the community and traders. However, does the Muar River still has that influences on this modern day? The answer of this pertinent question will fulfill the main objective of this study which is to discover Muar River relationship with its surrounding community. Approach: In addition to relationship with the river, this quantitative study was conducted to determine the Muar River community agreement towards initiative to develop the river. A total of 300 respondents from 19 villages along Muar River were selected based on the simple random sampling. Results: Based on the analysis of the results, it can be concluded that Muar River still has a lot to offer to its surrounding community especially for the recreational activities (fish and prawn fishing. A large majority of Muar River community have a moderate and high level of agreement towards the river development. Further analysis performed revealed that income per month, number of household, age, distance to Muar River and period of staying in the areas had significant relationships with agreement towards river development. Conclusion/Recommendations: It is recommended that additional recreational facilities can be added, events at national and international level especially on fish and prawn fishing can be held at Muar River and campaign on the importance of river development and the danger of river pollution can be conducted.

  11. The Origin of River Meanders

    Science.gov (United States)

    Sahagian, D. L.; Chatanantavet, P.; Bradley, C.; Friedgen-Veitch, D.; Diplas, P.

    2015-12-01

    Various propositions for the origin of meanders have been suggested in the past, involving local disturbances such as variable bank material, obstructions to flow, and sediment transport. Each of these approaches has required a very special and complex set of circumstances for the onset of meandering. However, meanders have also been observed in other systems such as the gulf stream , window glass , glacial meltwater, channels in submarine fans, the jet stream, water faucets, and many others. What has not been satisfactorily demonstrated is why some rivers (or parts of rivers) should tend to meander in the first place rather than ply a straight course to base level. We suggest that the fundamental cause of the river meander instability is simply a minimization of power (rate of work done), with an onset that occurs when inertial terms exceed body forces (e.g. gravity) acting on the flow, and thus create an adverse pressure gradient directed in the opposite direction of the flow. A simple way to visualize the cause of the instability is that the water "backs up" upon itself, running into a parcel of water downstream that is flowing more slowly than the water upstream. This causes the direction of maximum local water surface slope to be diverted to one side or the other of the regional slope. This can occur when a river encounters the ocean (or a lake, or a break in slope), and can occur in many other situations as well. We analyzed various meandering systems globally, and conducted laboratory experiments under controlled conditions to determine the conditions necessary for the onset of the meander instability. The results indicate that the meander instability does not depend on sediment or erodible banks. The critical threshold for the onset of the meander instability occurs when inertial forces exceed body forces acting on the fluid such that an adverse pressure gradient arises. Better understanding of the meander instability should thus elucidate some of the

  12. Updating river basin models with radar altimetry

    DEFF Research Database (Denmark)

    Michailovsky, Claire Irene B.

    -applications include the impact analysis of planned hydraulic structures or land use changes and the predicted impact of climate change on water availability. One of the obstacles hydrologists face in setting up river basin models is data availability, whether because the datasets needed do not exist or because....... Many types of RS are now routinely used to set up and drive river basin models. One of the key hydrological state variables is river discharge. It is typically the output of interest for water allocation applications and is also widely used as a source of calibration data as it presents the integrated...... response of a catchment to meteorological forcing. While river discharge cannot be directly measured from space, radar altimetry (RA) can measure water level variations in rivers at the locations where the satellite ground track and river network intersect called virtual stations or VS. In this PhD study...

  13. Decline of radionuclides in Columbia River biota

    International Nuclear Information System (INIS)

    In January 1971, the last of nine plutonium production reactors using direct discharge of once-through cooling waters into the Columbia River was closed. Sampling was initiated at three stations on the Columbia River to document the decline of the radionuclide body burdens in the biota of the Columbia River ecosystem. The data show that in a river-reservoir complex, the measurable body burden of fission-produced radionuclides decreased to essentially undetectable levels within 18 to 24 mo after cessation of discharge of once-through cooling water into the river. On the basis of data from the free-flowing station, we believe that this decrease would be even more rapid in an unimpounded river

  14. 1890's Land Cover/Use - Mississippi River Commission Surveys, Open River 1

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In the late 1880's and early 1900's the Mississippi River Commission (MRC) conducted an extensive high-resolution survey of the Mississippi River from Cairo,...

  15. 1890's Land Cover/Use - Mississippi River Commission Surveys, Open River 2

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In the late 1880's and early 1900's the Mississippi River Commission (MRC) conducted an extensive high-resolution survey of the Mississippi River from Cairo,...

  16. Color Infrared Orthorectified Photomosaic Leaf-off for New River Gorge National River Vegetation Mapping Project

    Data.gov (United States)

    National Park Service, Department of the Interior — Orthorectified color infrared ERDAS IMAGINE and MrSID image of New River Gorge National River (final_neri_mosaic.img). Produced from 471 color infrared photos taken...

  17. Unalakleet Wild River, Alaska, a wild and scenic river analysis: Preliminary draft

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Unalakleet River and its immediate surroundings possess the qualities necessary for inclusion in the National Wild and Scenic Rivers System. Provisions be made...

  18. Field Plot Points for New River Gorge National River Vegetation Mapping Project

    Data.gov (United States)

    National Park Service, Department of the Interior — This data set contains point features which represent locations of vegetation sampling plots in the New River Gorge National River. Location coordinates for most...

  19. Sequential sharing rules for river sharing problems

    OpenAIRE

    Ansink, Erik; Weikard, Hans-Peter

    2009-01-01

    We analyse the redistribution of a resource amongst agents who have claims to the resource and who are ordered linearly. A well known example of this particular situation is the river sharing problem. We exploit the linear order of agents to transform the river sharing problem to a sequence of two-agent river sharing problems. These reduced problems are mathematically equivalent to bankruptcy problems and can therefore be solved using any bankruptcy rule. Our proposed class of solutions, that...

  20. Creating a catchment perspective for river restoration

    OpenAIRE

    L. Benda; MILLER, D; J. Barquín

    2011-01-01

    One of the major challenges in river restoration is to identify the natural fluvial landscape in catchments with a long history of river control. Intensive land use on valley floors often predates the earliest remote sensing: levees, dikes, dams, and other structures alter valley-floor morphology, river channels and flow regimes. Consequently, morphological patterns indicative of the fluvial landscape including multiple channels, extensive floodplains, wetlands, and fluvial-riparian and tribu...

  1. Sediment load reduction in Chinese rivers

    Institute of Scientific and Technical Information of China (English)

    Cheng LIU; Jueyi SUI; Zhao-Yin WANG

    2008-01-01

    In this Paper,the changes in the annual runoff and sediment transport have been assessed by using the long term observation data from 10 gauging stations on 10 large rivers across China from far north to far south.It is found that the annual sediment yield has generally had a decreasing trend in the past half century.According to the changes in annual runoff and the sediment yield per area.rivers in China can be classified into the following three groups:1)rivers with decreasing annual sediment transport and stable runoff:2)rivers with both decreasing annual sediment transport and runoff and 3)rivers with greatly reduced annual sediment transport and decreasing annual runoff.The results indicate that,in all southern rivers(to the south of the Huaihe River including the Huaihe River),there has been little change in average annual runoff but a dramatic decrease in annual sediment transport.In the northern rivers.however,both the annual sediment yield and the runoff show significant evidence of reduction.To further investigate the recent changes in annual runoff and sediment transport.the short-term observation data from these 10 gauging stations in the recent 10 years have been assessed.Results show that both the annual sediment transport and the runoff have decreased significantly in the northern rivers in the past 10 years.Using the Yellow River at the Lijin Station as an example,the average annual runoff for the last 10 years is only 1/3 of the long term average value and the average annual sediment yield of the last 10 years is only 1/4 of the long term average value.More unusually,in the Yongding River the annual sediment yield has approached zero and the runoff has decreased significantly.In addition,the impacts of human activities on the changes in both runoff and sediment transport have been discussed.

  2. IDENTIFICATION OF RIVER WATER EXCESSIVE POLLUTION SOURCES

    OpenAIRE

    K. J. KACHIASHVILI; D. I. MELIKDZHANIAN

    2006-01-01

    The program package for identification of river water excessive pollution sources located between two controlled cross-sections of the river is described in this paper. The software has been developed by the authors on the basis of mathematical models of pollutant transport in the rivers and statistical hypotheses checking methods. The identification algorithms were elaborated with the supposition that the pollution sources discharge different compositions of pollutants or (at the identical c...

  3. Morphology of Tigris River within Baghdad City

    Directory of Open Access Journals (Sweden)

    A. A. Ali

    2012-05-01

    Full Text Available Changes in the morphology of the River Tigris within Baghdad City are very noticeable in recent years. The number of islands is increasing with time despite the fact that huge amount of sediments are trapped in reservoirs upstream Baghdad City. The debris of destroyed bridges in the wars of 1991 and 2003 had enhanced the development of these islands. As a consequence the ability of the river had been reduced to pass flood waves. This fact caused partial flooding of parts of Baghdad City.

    Cross sections of the River Tigris were surveyed in three occasions (1976, 1991 and 2008. The last survey conducted in 2008 by Ministry of Water Resources covered 49 km of the river from Al-Muthana Bridge to its confluence with Diyala River at 250 m intervals. The data was used to predict the maximum flood capacity for the river using one-dimensional hydraulic model for steady flow "HEC-RAS". Calibration was carried out for the model using field measurements for water levels along the last 15 km from its reach and the last 10 yr observations at Sarai Baghdad station.

    The average discharge of the river in Baghdad had been calculated for the past ten years. This value was introduced in the model. Then different scenarios were applied by increasing the discharge in order to find out the critical discharge that can cause inundation. The procedure continued to detect the areas that had been inundated and the water level was recorded.

    The model showed a significant reduction in the current river capacity in comparison with what the river had used to hold during floods of 1971 and 1988. The three surveys conducted on the same reach of the River Tigris indicated that the capacity of the river to pass water had been decreased. In addition the changes in the morphology of the river cross sections were very clear.

  4. 241Pu in the biggest Polish rivers

    OpenAIRE

    Dagmara I. Strumińska-Parulska; Skwarzec, Bogdan

    2013-01-01

    In the paper the results of 241Pu activity concentration determination in the biggest Polish rivers are presented. The analysis of more than 100 river water samples showed the Vistula and the Odra as well as three Pomeranian Rivers are important sources of 241Pu in the southern Baltic Sea. There were differences in 241Pu activities depending on season and sampling site and the plutonium contamination came mainly from the global atmospheric fallout as well as the Chernobyl accident, which is c...

  5. Assessment of Missouri River floodplain invertebrates during historic inundation: implications for river restoration

    OpenAIRE

    Gosch N.J.C.; Miller M.L.; Dzialowski A.R.; Morris D.M.; Gemeinhardt T.R.; Bonneau J.L.

    2014-01-01

    Floodplain connectivity is important to aquatic organisms in large rivers. Anthropogenic alterations regulating the Missouri River have limited connectivity and negatively affected native fauna. Determining the biological response to rare inundation events may be important when considering potential restoration options on a regulated river; thus, we assessed benthic invertebrate and zooplankton communities at three floodplain sites during a historic Missouri River high-water event. Chironomid...

  6. Evaluation of Early Effects of the River Restoration Project in the Kamisaigo River Japan

    OpenAIRE

    Lopa, Rita Tahir

    2013-01-01

    The Kamisaigo River has been restored by the Fukutsu City Government to improve the environmental quality of the river. Many different restoration measures have already been applied but only few projects have been monitored and knowledge on the effects is still limited. Therefore, we conducted a study in the Kamisaigo River, Fukuoka Prefecture Japan. The Kamisaigo River mainstream is divided into six sections called restored sites and have been???installed different types of restoration appr...

  7. Savannah River Laboratory monthly report, August 1991

    Energy Technology Data Exchange (ETDEWEB)

    Ferrell, J.M. [comp.

    1991-12-31

    This document details monthly activities at the Savannah River Laboratory. Topics addressed are reactor operation, tritium facilities and production; separation operations; environmental concerns; and waste management. (FI)

  8. Savannah River Laboratory monthly report, August 1991

    Energy Technology Data Exchange (ETDEWEB)

    Ferrell, J.M. (comp.)

    1991-01-01

    This document details monthly activities at the Savannah River Laboratory. Topics addressed are reactor operation, tritium facilities and production; separation operations; environmental concerns; and waste management. (FI)

  9. Savannah River Laboratory monthly report, October 1991

    Energy Technology Data Exchange (ETDEWEB)

    Ferrell, J.M. [comp.

    1991-12-31

    This document details monthly activities at the Savannah River Laboratory. Topics addressed are reactor operation, tritium facilities and production; separations operations; environmental concerns; and waste management. (FI)

  10. Savannah River Laboratory monthly report, October 1991

    Energy Technology Data Exchange (ETDEWEB)

    Ferrell, J.M. (comp.)

    1991-01-01

    This document details monthly activities at the Savannah River Laboratory. Topics addressed are reactor operation, tritium facilities and production; separations operations; environmental concerns; and waste management. (FI)

  11. Savannah River Laboratory monthly report, November 1991

    Energy Technology Data Exchange (ETDEWEB)

    Ferrell, J.M. (comp.)

    1991-01-01

    This document details monthly activities at the Savannah River Laboratory. Topics addressed are reactor operation; tritium facilities and production; separation operations; environmental concerns; and waste management. (FI)

  12. Savannah River Laboratory monthly report, November 1991

    Energy Technology Data Exchange (ETDEWEB)

    Ferrell, J.M. [comp.

    1991-12-31

    This document details monthly activities at the Savannah River Laboratory. Topics addressed are reactor operation; tritium facilities and production; separation operations; environmental concerns; and waste management. (FI)

  13. River Restoration Data in Lamoille County, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Documented river and riparian buffer restoration projects in Lamoille County, Vermont. Restoration includes buffer plantings (trees and shrubs), bank stabilization...

  14. The Columbia River System Inside Story

    Energy Technology Data Exchange (ETDEWEB)

    None

    2001-04-01

    The Columbia River is one of the greatest natural resources in the western United States. The river and its tributaries touch the lives of nearly every resident of the Pacific Northwest—from fostering world-famous Pacific salmon to supplying clean natural fuel for 50 to 65 percent of the region’s electrical generation. Since early in the 20th century, public and private agencies have labored to capture the benefits of this dynamic river. Today, dozens of major water resource projects throughout the region are fed by the waters of the Columbia Basin river system.

  15. River flow controls on tides an tide-mean water level profiles in a tidel freshwater river

    NARCIS (Netherlands)

    Sassi, M.G.; Hoitink, A.J.F.

    2013-01-01

    [1] Tidal rivers feature oscillatory and steady gradients in the water surface, controlled by interactions between river flow and tides. The river discharge attenuates the tidal motion, and tidal motion increases tidal-mean friction in the river, which may act as a barrier to the river discharge. Ti

  16. 78 FR 21839 - Drawbridge Operation Regulation; Green River, Small-house, KY and Black River, Jonesboro, LA

    Science.gov (United States)

    2013-04-12

    ... River, mile 79.6, Small- house, KY and Black River, mile 41.0, Jonesboro, LA. The Green River bridge was... SECURITY Coast Guard 33 CFR Part 117 RIN 1625-AA09 Drawbridge Operation Regulation; Green River, Small-house, KY and Black River, Jonesboro, LA AGENCY: Coast Guard, DHS. ACTION: Final rule. SUMMARY:...

  17. 33 CFR 207.330 - Mississippi River between Winnibigoshish and Pokegama dams, Leech River between outlet of Leech...

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Mississippi River between Winnibigoshish and Pokegama dams, Leech River between outlet of Leech Lake and Mississippi River, and Pokegama... Winnibigoshish and Pokegama dams, Leech River between outlet of Leech Lake and Mississippi River, and...

  18. Challenges of river basin management: Current status of, and prospects for, the River Danube from a river engineering perspective.

    Science.gov (United States)

    Habersack, Helmut; Hein, Thomas; Stanica, Adrian; Liska, Igor; Mair, Raimund; Jäger, Elisabeth; Hauer, Christoph; Bradley, Chris

    2016-02-01

    In the Danube River Basin multiple pressures affect the river system as a consequence of river engineering works, altering both the river hydrodynamics and morphodynamics. The main objective of this paper is to identify the effects of hydropower development, flood protection and engineering works for navigation on the Danube and to examine specific impacts of these developments on sediment transport and river morphology. Whereas impoundments are characterised by deposition and an excess of sediment with remobilisation of fine sediments during severe floods, the remaining five free flowing sections of the Danube are experiencing river bed erosion of the order of several centimetres per year. Besides the effect of interruption of the sediment continuum, river bed degradation is caused by an increase in the sediment transport capacity following an increase in slope, a reduction of river bed width due to canalisation, prohibition of bank erosion by riprap or regressive erosion following base level lowering by flood protection measures and sediment dredging. As a consequence, the groundwater table is lowered, side-arms are disconnected, instream structures are lost and habitat quality deteriorates affecting the ecological status of valuable floodplains. The lack of sediments, together with cutting off meanders, leads also to erosion of the bed of main arms in the Danube Delta and coastal erosion. This paper details the causes and effects of river engineering measures and hydromorphological changes for the Danube. It highlights the importance of adopting a basin-wide holistic approach to river management and demonstrates that past management in the basin has been characterised by a lack of integration. To-date insufficient attention has been paid to the wide-ranging impacts of river engineering works throughout the basin: from the basin headwaters to the Danube Delta, on the Black Sea coast. This highlights the importance of new initiatives that seek to advance knowledge

  19. Rivers running deep : complex flow and morphology in the Mahakam River, Indonesia

    NARCIS (Netherlands)

    Vermeulen, B.

    2014-01-01

    Rivers in tropical regions often challenge our geomorphological understanding of fluvial systems. Hairpin bends, natural scours, bifurcate meander bends, tie channels and embayments in the river bank are a few examples of features ubiquitous in tropical rivers. Existing observation techniques fall s

  20. 78 FR 28492 - Special Local Regulation; Low Country Splash, Wando River, Cooper River, and Charleston Harbor...

    Science.gov (United States)

    2013-05-15

    ..., Cooper River, and Charleston Harbor, Charleston, SC'' in the Federal Register (78 FR 18277). We received.... SUPPLEMENTARY INFORMATION: Table of Acronyms DHS Department of Homeland Security FR Federal Register NPRM Notice... River, Cooper River, and Charleston Harbor; Charleston, SC AGENCY: Coast Guard, DHS. ACTION:...

  1. Recent Record of the Neotropical River Otter (Lontra longicaudis in the Choluteca River Tegucigalpa, Honduras

    Directory of Open Access Journals (Sweden)

    Francisco Aceituno

    2015-12-01

    Full Text Available We report the presence of the Neotropical river otter (Lontra longicaudis in the Choluteca River, Tegucigalpa, Honduras. To date the information is the second record verifiable of the species in the Choluteca River since one in the 1940s.

  2. 78 FR 49918 - Drawbridge Operation Regulation; Taunton River, Fall River and Somerset, MA

    Science.gov (United States)

    2013-08-16

    ...) entitled, ``Drawbridge Operation Regulation: Taunton River, Fall River and Somerset, MA'' in the Federal Register (78 FR 31457). We received no comments on the proposed rule. No public meeting was requested, and... River and Somerset, MA AGENCY: Coast Guard, DHS. ACTION: Final rule. SUMMARY: The Coast Guard...

  3. Reflections on Development Strategy of Pearl River Delta: In Comparison with Yangtze River Delta

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    <正>1. A comparison between Pearl River Delta and Yangtze River Delta 1.1 Basic conditions 1.1.1 Location, area and scope Located in the southeast of Guangdong Province, the Pearl River Delta (PRD) as an economic zone is a compound delta

  4. 33 CFR 207.10 - Charles River, Mass.; dam of Charles River Basin Commission.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Charles River, Mass.; dam of Charles River Basin Commission. 207.10 Section 207.10 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.10 Charles River, Mass.; dam...

  5. 76 FR 24914 - Digital River Education Services, Inc., a Division of Digital River, Inc., Including Workers...

    Science.gov (United States)

    2011-05-03

    ... Employment and Training Administration Digital River Education Services, Inc., a Division of Digital River... Marketing (JEM), Including On-Site Lease Workers From Serenity Staffing, Accountemps, Silicon Valley, and... Assistance on January 28, 2011, applicable to workers of Digital River Education Services, Inc., a...

  6. Methodology for estimation of river discharge and applicationof the Zhujiang River Estuary (ZRE)

    Institute of Scientific and Technical Information of China (English)

    CHENJay-Chung; WONGLai-Ah

    2004-01-01

    The ZRE is a very complicated estuary with multi-river inlets. The total sum of river discharge in the upstream(away from the tidal influence region) of the Zhujiang River can be easily measured. However, when the total river discharges into the estuary from eight inlets, it is a very difficult task to obtain a continuous river discharge flux data from each branch of the Zhujiang River. However, the different ratios of river discharges between the river branches can significantly affect the estuarine circulation feature and baroclinic process. Moreover, the accuracy of numerical forecast for the estuarine circulation is very much dependent on the accuracy of the time history of the river discharge flux for each branch. Therefore, it is important to estimate river discharge from each branch in order to improve the accuracy of the model forecast for the circulation of the ZRE. The development of a new estimation method of the river discharges is focused on based on the system identification theory, numerical modeling and the time history data from the CODAR observed sea surface current. The new approach has been appfied to estimating the time history (hourly) of river discharge from each branch in the upstream of the ZRE.

  7. Consequence Analyses Following Potential Savannah River Site Hydrological Releases

    Energy Technology Data Exchange (ETDEWEB)

    Blanchard, A.

    1999-07-28

    Postulated accidental release of radiological material to surface water bodies on the Savannah River Site and the resulting downstream contamination of the Savannah River pose a potential threat to downstream river users.

  8. Inputs from Indian rivers to the ocean: A synthesis

    Digital Repository Service at National Institute of Oceanography (India)

    DileepKumar, M.; George, M.D.; SenGupta, R.

    ). Fluxes of chemical substances to the Indian Ocean from these rivers are computed to a first approximation. The major ion contents are inversely proportional to the river runoff especially for the rivers entering the Arabian Sea. On an average Indian...

  9. Elk River Watershed - Flood Study

    Science.gov (United States)

    Barnes, C. C.; Byrne, J. M.; MacDonald, R. J.; Lewis, D.

    2014-12-01

    Flooding has the potential to cause significant impacts to economic activities as well as to disrupt or displace populations. Changing climate regimes such as extreme precipitation events increase flood vulnerability and put additional stresses on infrastructure. Potential flooding from just under 100 (2009 NPRI Reviewed Facility Data Release, Environment Canada) toxic tailings ponds located in Canada increase risk to human safety and the environment. One such geotechnical failure spilt billions of litres of toxic tailings into the Fraser River watershed, British Columbia, when a tailings pond dam breach occurred in August 2014. Damaged and washed out roadways cut access to essential services as seen by the extensive floods that occurred in Saskatchewan and Manitoba in July 2014, and in Southern Alberta in 2013. Recovery efforts from events such as these can be lengthy, and have substantial social and economic impacts both in loss of revenue and cost of repair. The objective of this study is to investigate existing conditions in the Elk River watershed and model potential future hydrological changes that can increase flood risk hazards. By analyzing existing hydrology, meteorology, land cover, land use, economic, and settlement patterns a baseline is established for existing conditions in the Elk River watershed. Coupling the Generate Earth Systems Science (GENESYS) high-resolution spatial hydrometeorological model with flood hazard analysis methodology, high-resolution flood vulnerability base line maps are created using historical climate conditions. Further work in 2015 will examine possible impacts for a range of climate change and land use change scenarios to define changes to future flood risk and vulnerability.

  10. Inundation risk for embanked rivers

    Science.gov (United States)

    Strupczewski, W. G.; Kochanek, K.; Bogdanowicz, E.; Markiewicz, I.

    2013-08-01

    The Flood Frequency Analysis (FFA) concentrates on probability distribution of peak flows of flood hydrographs. However, examination of floods that haunted and devastated the large parts of Poland lead us to revision of the views on the assessment of flood risk of Polish rivers. It turned out that flooding is caused not only by the overflow of the levee crest but also due to the prolonged exposure to high water on levees structure causing dangerous leaks and breaches that threaten their total destruction. This is because the levees are weakened by long-lasting water pressure and as a matter of fact their damage usually occurs after the culmination has passed the affected location. The probability of inundation is the total of probabilities of exceeding embankment crest by flood peak and the probability of washout of levees. Therefore, in addition to the maximum flow one should also consider the duration of high waters in a river channel. In the paper the new two-component model of flood dynamics: "Duration of high waters-Discharge Threshold-Probability of non-exceedance" (DqF), with the methodology of its parameter estimation was proposed as a completion to the classical FFA methods. Such a model can estimate the duration of stages (flows) of an assumed magnitude with a given probability of exceedance. The model combined with the technical evaluation of the probability of levee breaches due to the duration (d) of flow above alarm stage gives the annual probability of inundation caused by the embankment breaking. The results of theoretical investigation were illustrated by a practical example of the model implementation to the series of daily flow of the Vistula River at Szczucin. Regardless of promising results, the method of risk assessment due to prolonged exposure of levees to high water is still in its infancy despite its great cognitive potential and practical importance. Therefore, we would like to point out the need for and usefulness of the DqF model as

  11. Savannah River Site dose control

    International Nuclear Information System (INIS)

    Health physicists from the Brookhaven National Laboratory (BNL) visited the Savannah River Site (SRS) as one of 12 facilities operated by the Department of Energy (DOE) contractors with annual collective dose equivalents greater than 100 person-rem (100 person-cSv). Their charter was to review, evaluate and summarize as low as reasonably achievable (ALARA) techniques, methods and practices as implemented. This presentation gives an overview of the two selected ALARA practices implemented at the SRS: Administrative Exposure Limits and Goal Setting. These dose control methods are used to assure that individual and collective occupational doses are ALARA and within regulatory limits

  12. Pearls in Pearl River Delta

    Institute of Scientific and Technical Information of China (English)

    Yan Manman

    2009-01-01

    @@ When the Pearls in Pearl River Delta (PRD) is mentioned,Hong Kong will also naturally jump to people's mind.It must not only due to PRD's proximity with Hong Kong,but also due to Hong Kong s special role in the development of this region.Admittedly,Hong Kong really provided strong drive for the takeoff of the PRD Economic Zone.But with the prosperity of PRD,the nearly tailored combinations and complementarity have taken shape between Hong Kong and PRD,pushing the economy in the two areas to grow far more rapidly than otherwise.

  13. Environmental Ethics in River Water Management

    Directory of Open Access Journals (Sweden)

    Ravichandran Moorthy

    2011-01-01

    Full Text Available Problem statement: Environmental ethics concerns human beings’ ethical relationship with the natural environment. The fundamental question regarding environmental ethics is basically-what moral obligations do we have concerning the natural environment? The main objective of this study is to examine the extent environmental ethics manifest in river management. The study employs the case study of Malaysia's Gombak River-one of the most polluted urban rivers that run through some heavily inhabited urban areas. The study examines how the Department of Environment (DOE, Drainage and Irrigation Department (DID and Selayang Municipal Council (MPS manage the problem of pollution in the Gombak River. Approach: This study uses both quantitative and qualitative analysis. A quantitative approach is employed to assess the water quality in several points along Gombak River. This is done by way of series of scientific testing to determine the level of pollution in the river. Secondly, a qualitative approach is applied on the data gathered through expert interviews on inter-agency coordination efforts to manage pollution problems. Results: The study firstly shows that the Gombak River is considerably polluted, with higher levels of pollution in upstream as compared to the downstream. The second finding suggests that notwithstanding several legislations that are already in place, there is sluggishness in the enforcement of pollution mitigation efforts as a result of ineffective inter-agency communication and coordination. Conclusion: The lack of concerted and coordinated efforts between river management agencies have been cited as one of the main factors contributing to river pollution. Therefore, the agencies concerned should embark on cohesive measures to ensure the rivers are managed well and its water quality controlled. This requires for a structured coordination mechanism between agencies to be put in place and such mechanism can be emulated in the

  14. River geomorphology and fish barriers affect on spatial and temporal patterns of fish assemblages in the Niobrara River, Nebraska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Niobrara River in northern Nebraska traverses the heart of the Great Plains with portions of the river protected under the National Wild and Scenic River system...

  15. THE FORMING CONDITIONS OF ALLUVIAL RIVER CHANNEL PATTERNS

    Institute of Scientific and Technical Information of China (English)

    Pu QI; Gouting LIANG; Zangying SUN; Honghai QI

    2002-01-01

    In normal fluvial processes the river channel is determined by river flows while the movement of river flows is contained by river channels. The relationship between the river morphology and its bend curvature shows that rivers with large bend curvatures always have narrow and deep channels and those with shallow and wide channels are always straight. The plan form of a river reaches is determined by the cross-sectional morphology. A meandering river reach may be developed under various water-sediment conditions as long as the narrow and deep channels are formed.

  16. Compromised Rivers: Understanding Historical Human Impacts on Rivers in the Context of Restoration

    Directory of Open Access Journals (Sweden)

    Ellen Wohl

    2005-12-01

    Full Text Available A river that preserves a simplified and attractive form may nevertheless have lost function. Loss of function in these rivers can occur because hydrologic and geomorphic processes no longer create and maintain the habitat and natural disturbance regimes necessary for ecosystem integrity. Recognition of compromised river function is particularly important in the context of river restoration, in which the public perception of a river's condition often drives the decision to undertake restoration as well as the decision about what type of restoration should be attempted. Determining the degree to which a river has been altered from its reference condition requires a knowledge of historical land use and the associated effects on rivers. Rivers of the Front Range of the Colorado Rocky Mountains in the United States are used to illustrate how historical land uses such as beaver trapping, placer mining, tie drives, flow regulation, and the construction of transportation corridors continue to affect contemporary river characteristics. Ignorance of regional land use and river history can lead to restoration that sets unrealistic goals because it is based on incorrect assumptions about a river's reference condition or about the influence of persistent land-use effects.

  17. Red River Basin Mapping 2008-2010

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — This LiDAR data covers the Red River Basin with portions of ND, MN, SD and flows into Canada. The US Red River Basin boudnary covers 40,860 sqmi,with the additional...

  18. 33 CFR 117.215 - Niantic River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Niantic River. 117.215 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Connecticut § 117.215 Niantic River. (a) The draw of the Amtrak bridge, mile 0.0 at Niantic, shall open on signal; except that, from April 1...

  19. 33 CFR 117.1095 - Root River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Root River. 117.1095 Section 117.1095 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Wisconsin § 117.1095 Root River. (a) The draw of the Main...

  20. 33 CFR 117.713 - Cooper River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Cooper River. 117.713 Section 117.713 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.713 Cooper River. (a) The drawspans for...

  1. 33 CFR 117.925 - Cooper River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Cooper River. 117.925 Section 117.925 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements South Carolina § 117.925 Cooper River. The draw of the...

  2. Experimental meandering river with chute cutoffs

    NARCIS (Netherlands)

    Dijk, W.M. van; Lageweg, W.I. van de; Kleinhans, M.G.

    2012-01-01

    Braided rivers are relatively simple to produce in the laboratory, whereas dynamic meandering rivers have not been sustained beyond initial bend formation. Meandering is theoretically explained by bend instability growing from planimetric perturbation, which convects downstream. In this study, we ex

  3. Excessive nitrogen and phosphorus in European rivers

    NARCIS (Netherlands)

    Blaas, Harry; Kroeze, Carolien

    2016-01-01

    Rivers export nutrients to coastal waters. Excess nutrient export may result in harmful algal blooms and hypoxia, affecting biodiversity, fisheries, and recreation. The purpose of this study is to quantify for European rivers (1) the extent to which N and P loads exceed levels that minimize the r

  4. 33 CFR 117.415 - Green River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Green River. 117.415 Section 117... OPERATION REGULATIONS Specific Requirements Kentucky § 117.415 Green River. (a) The draw of the CSX... vicinity. (b) The draw of the CSX Transportation Railroad bridge, Mile 79.6 at Small-house, is...

  5. 33 CFR 117.107 - Chattahoochee River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Chattahoochee River. 117.107 Section 117.107 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Alabama § 117.107 Chattahoochee River. The draws...

  6. 33 CFR 117.486 - Pearl River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Pearl River. 117.486 Section 117.486 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.486 Pearl River. (a) The draw of the...

  7. 33 CFR 117.527 - Kennebunk River.

    Science.gov (United States)

    2010-07-01

    ... board gages in accordance with 33 CFR 118.160, of this chapter. ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Kennebunk River. 117.527 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maine § 117.527 Kennebunk River. The Dock...

  8. 33 CFR 117.131 - Little River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Little River. 117.131 Section 117.131 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Arkansas § 117.131 Little River. The draws of the...

  9. 33 CFR 117.523 - Back River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Back River. 117.523 Section 117.523 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maine § 117.523 Back River. The draw of the Maine Department...

  10. 33 CFR 117.217 - Norwalk River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Norwalk River. 117.217 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Connecticut § 117.217 Norwalk River. (a) The draw of.... to 12 p.m., on the first Saturday in December, to facilitate the running of the annual Norwalk...

  11. 33 CFR 117.109 - Coosa River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Coosa River. 117.109 Section 117.109 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Alabama § 117.109 Coosa River. The draw of the...

  12. 33 CFR 117.121 - Arkansas River

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Arkansas River 117.121 Section 117.121 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Arkansas § 117.121 Arkansas River The draw of...

  13. 33 CFR 117.567 - Patuxent River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Patuxent River. 117.567 Section 117.567 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.567 Patuxent River. The draw of...

  14. 33 CFR 117.139 - White River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false White River. 117.139 Section 117.139 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Arkansas § 117.139 White River. (a) The draws of the St....

  15. 33 CFR 117.187 - Petaluma River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Petaluma River. 117.187 Section 117.187 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements California § 117.187 Petaluma River. (a) The draws...

  16. 33 CFR 117.365 - Oconee River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Oconee River. 117.365 Section 117.365 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Georgia § 117.365 Oconee River. The draw of the SR46...

  17. 33 CFR 117.319 - Oklawaha River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Oklawaha River. 117.319 Section 117.319 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.319 Oklawaha River. (a) The draw of...

  18. 33 CFR 117.575 - Susquehanna River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Susquehanna River. 117.575 Section 117.575 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.575 Susquehanna River. The draw of...

  19. 33 CFR 117.480 - Mermentau River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Mermentau River. 117.480 Section 117.480 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.480 Mermentau River. The draw of...

  20. 33 CFR 117.389 - Calumet River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Calumet River. 117.389 Section 117.389 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Illinois § 117.389 Calumet River. The draws of...

  1. 33 CFR 80.715 - Savannah River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Savannah River. 80.715 Section 80.715 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Seventh District § 80.715 Savannah River. A line drawn from...

  2. 33 CFR 117.423 - Atchafalaya River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Atchafalaya River. 117.423 Section 117.423 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.423 Atchafalaya River. The draw of...

  3. 33 CFR 117.381 - Clearwater River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Clearwater River. 117.381 Section 117.381 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Idaho § 117.381 Clearwater River. The draws of...

  4. 33 CFR 117.127 - Current River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Current River. 117.127 Section 117.127 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Arkansas § 117.127 Current River. The draws of...

  5. 33 CFR 117.219 - Pequonnock River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Pequonnock River. 117.219 Section 117.219 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Connecticut § 117.219 Pequonnock River. (a)...

  6. 33 CFR 117.588 - Bass River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Bass River. 117.588 Section 117.588 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Massachusetts § 117.588 Bass River. The Hall Whitaker...

  7. 33 CFR 117.551 - Chester River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Chester River. 117.551 Section 117.551 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.551 Chester River. The draw of the...

  8. 33 CFR 117.361 - Flint River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Flint River. 117.361 Section 117.361 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Georgia § 117.361 Flint River. The draws of the...

  9. 33 CFR 117.205 - Connecticut River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Connecticut River. 117.205 Section 117.205 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Connecticut § 117.205 Connecticut River. (a)...

  10. 33 CFR 117.533 - Sheepscot River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Sheepscot River. 117.533 Section 117.533 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maine § 117.533 Sheepscot River. The draw of the...

  11. 33 CFR 117.503 - Tensas River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Tensas River. 117.503 Section 117.503 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.503 Tensas River. The draws of the S15...

  12. 33 CFR 117.553 - Choptank River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Choptank River. 117.553 Section 117.553 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.553 Choptank River. (a) The draw of...

  13. 33 CFR 117.211 - Mystic River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Mystic River. 117.211 Section 117.211 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Connecticut § 117.211 Mystic River. (a) The draw of the...

  14. 33 CFR 117.457 - Houston River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Houston River. 117.457 Section 117.457 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.457 Houston River. The draw of...

  15. 33 CFR 117.367 - Ogeechee River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Ogeechee River. 117.367 Section 117.367 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Georgia § 117.367 Ogeechee River. (a) The draw of...

  16. 33 CFR 117.363 - Ocmulgee River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Ocmulgee River. 117.363 Section 117.363 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Georgia § 117.363 Ocmulgee River. The draws of...

  17. 33 CFR 117.587 - Apponagansett River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Apponagansett River. 117.587 Section 117.587 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Massachusetts § 117.587 Apponagansett River. (a)...

  18. 33 CFR 117.525 - Kennebec River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Kennebec River. 117.525 Section 117.525 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maine § 117.525 Kennebec River. (a) The draw of...

  19. 33 CFR 117.473 - Little River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Little River. 117.473 Section 117.473 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.473 Little River. The draw of the Louisiana...

  20. 33 CFR 117.500 - Tchefuncta River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Tchefuncta River. 117.500 Section 117.500 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.500 Tchefuncta River. The draw of...

  1. 33 CFR 117.295 - Kissimmee River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Kissimmee River. 117.295 Section 117.295 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.295 Kissimmee River. The draw of the...

  2. 33 CFR 117.125 - Black River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Black River. 117.125 Section 117.125 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Arkansas § 117.125 Black River. The following draws need not...

  3. 33 CFR 117.417 - Ohio River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Ohio River. 117.417 Section 117.417 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Kentucky § 117.417 Ohio River. The draw of the Southern...

  4. 33 CFR 117.403 - Wabash River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Wabash River. 117.403 Section 117.403 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Indiana § 117.403 Wabash River. See § 117.397, Wabash...

  5. 33 CFR 117.101 - Alabama River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Alabama River. 117.101 Section 117.101 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Alabama § 117.101 Alabama River. (a) The...

  6. 33 CFR 117.207 - Housatonic River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Housatonic River. 117.207 Section 117.207 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Connecticut § 117.207 Housatonic River. (a) The...

  7. 33 CFR 117.585 - Acushnet River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Acushnet River. 117.585 Section 117.585 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Massachusetts § 117.585 Acushnet River. (a)...

  8. 33 CFR 117.271 - Blackwater River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Blackwater River. 117.271 Section 117.271 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.271 Blackwater River. The draw of...

  9. 33 CFR 117.483 - Ouachita River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Ouachita River. 117.483 Section 117.483 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.483 Ouachita River. The draw of the...

  10. 33 CFR 117.529 - Narraguagus River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Narraguagus River. 117.529 Section 117.529 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maine § 117.529 Narraguagus River. The draw of...

  11. 33 CFR 117.241 - Mispillion River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Mispillion River. 117.241 Section 117.241 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Delaware § 117.241 Mispillion River. The draw of...

  12. 33 CFR 117.369 - Satilla River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Satilla River. 117.369 Section 117.369 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Georgia § 117.369 Satilla River. The draw of...

  13. 33 CFR 117.371 - Savannah River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Savannah River. 117.371 Section 117.371 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Georgia § 117.371 Savannah River. (a) The draw of...

  14. 33 CFR 117.509 - Vermilion River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Vermilion River. 117.509 Section 117.509 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.509 Vermilion River. (a) The draw...

  15. 33 CFR 117.253 - Anacostia River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Anacostia River. 117.253 Section 117.253 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements District of Columbia § 117.253 Anacostia River....

  16. 33 CFR 117.113 - Tensaw River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Tensaw River. 117.113 Section 117.113 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Alabama § 117.113 Tensaw River. The draw of the...

  17. 33 CFR 117.245 - Smyrna River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Smyrna River. 117.245 Section 117.245 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Delaware § 117.245 Smyrna River. The draw of the...

  18. 33 CFR 117.422 - Amite River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Amite River. 117.422 Section 117.422 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.422 Amite River. (a) The draw of the S22...

  19. 33 CFR 117.569 - Pocomoke River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Pocomoke River. 117.569 Section 117.569 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.569 Pocomoke River. (a) The...

  20. 33 CFR 117.351 - Altamaha River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Altamaha River. 117.351 Section 117.351 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Georgia § 117.351 Altamaha River. (a) The draws of...

  1. 33 CFR 117.224 - Thames River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Thames River. 117.224 Section 117.224 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Connecticut § 117.224 Thames River. The draw of the...

  2. 33 CFR 117.141 - American River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false American River. 117.141 Section 117.141 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements California § 117.141 American River. The draw of...

  3. 33 CFR 117.133 - Ouachita River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Ouachita River. 117.133 Section 117.133 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Arkansas § 117.133 Ouachita River. The draw of the...

  4. 33 CFR 117.255 - Potomac River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Potomac River. 117.255 Section 117.255 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements District of Columbia § 117.255 Potomac River. (a)...

  5. 33 CFR 117.427 - Black River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Black River. 117.427 Section 117.427 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.427 Black River. The draw of the US84...

  6. 33 CFR 117.209 - Mianus River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Mianus River. 117.209 Section 117.209 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Connecticut § 117.209 Mianus River. The draw of the...

  7. 33 CFR 117.493 - Sabine River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Sabine River. 117.493 Section 117.493 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.493 Sabine River. (a) The draw of the...

  8. 33 CFR 117.243 - Nanticoke River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Nanticoke River. 117.243 Section 117.243 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Delaware § 117.243 Nanticoke River. (a) The draw...

  9. 33 CFR 117.221 - Saugatuck River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Saugatuck River. 117.221 Section 117.221 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Connecticut § 117.221 Saugatuck River. (a)...

  10. 33 CFR 117.313 - New River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false New River. 117.313 Section 117.313 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.313 New River. (a) The draw of the SE....

  11. 33 CFR 117.565 - Miles River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Miles River. 117.565 Section 117.565 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.565 Miles River. The draw of the Route...

  12. Sulfate-reducing prokaryotes in river floodplains

    NARCIS (Netherlands)

    Miletto, M.

    2007-01-01

    This thesis constitutes a pioneer attempt at elucidating the ecology of sulfate-reducing prokaryotes in river floodplains. These are non-typical sulfate-reducing environmental settings, given the generally low sulfate concentration that characterize freshwater habitats, and river flow regulation tha

  13. 33 CFR 117.385 - Snake River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Snake River. 117.385 Section 117.385 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Idaho § 117.385 Snake River. The drawspan of the U.S. 12...

  14. 33 CFR 117.135 - Red River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Red River. 117.135 Section 117.135 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Arkansas § 117.135 Red River. The draws of the bridges...

  15. 33 CFR 117.491 - Red River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Red River. 117.491 Section 117.491 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.491 Red River. (a) The draw of the Union...

  16. 33 CFR 117.263 - Banana River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Banana River. 117.263 Section 117.263 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.263 Banana River. (a) The draw of the Mathers...

  17. Straight river: its formation and speciality

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Straight river is generally regarded as one of the typical river patterns in conventional classifications in terms of their channel plain landforms. However, very few straight patterns were found to be distributed in wider spatial and temporal spans in the self-adjusted fluvial rivers. Thus, the questions occur such as that is it possible for a channel takes on a stable straight pattern? What are the main factors controlling the processes of the river pattern formation and transformation from a straight to other patterns? Various theories and hypotheses including geomorphic threshold hypothesis, the extreme hypothesis on energy dissipation rate, the stability theory, etc. have been developed to explain the aforementioned questions, but none of them is sound for the explanation to the straight-river formation. From the modern fluvial plain patterns, the straight patterns are not as stable as other typical patterns which occurred in nature; from the historic records of the river sedimentation, no apparent evidence was found to support the stable straight river evolution. Based on the analysis of existing theories, observations, evolvement processes of the channel patterns in the experimental results, this paper concluded that the straight pattern should not be included as one of the typical patterns that are self-formed and developed. This study is of importance to understanding of the river pattern formation and transformation.

  18. Environmental protection in the Alligator Rivers Region

    International Nuclear Information System (INIS)

    One of a series of articles on the work of the Office of the Supervising Scientist for the Alligator Rivers Region (OSS) and its Alligator Rivers Region Research Institute (ARRRI), this discusses the environmental protection function of the OSS and the role of the ARRRI in achieving this

  19. Savannah River Site Environmental Report for 1998

    International Nuclear Information System (INIS)

    The mission at the Savannah River Site (SRS) is focused primarily on support of the national defense, nonproliferation, and environmental cleanup. SRS-through its prime operating contractor, Westinghouse Savannah River Company-continues to maintain a comprehensive environmental monitoring program

  20. 33 CFR 117.773 - Buffalo River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Buffalo River. 117.773 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New York § 117.773 Buffalo River. (a) The draw of the Michigan Avenue bridge, mile 1.3, at Buffalo, shall operate as follows: (1) From March 22 through...

  1. Savannah River Site Environmental Report for 1998

    Energy Technology Data Exchange (ETDEWEB)

    Arnett, M

    1999-06-09

    The mission at the Savannah River Site (SRS) is focused primarily on support of the national defense, nonproliferation, and environmental cleanup. SRS-through its prime operating contractor, Westinghouse Savannah River Company-continues to maintain a comprehensive environmental monitoring program.

  2. 33 CFR 117.755 - Shrewsbury River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Shrewsbury River. 117.755 Section 117.755 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.755 Shrewsbury River. (a) The...

  3. Sandbar-regulated hydrodynamic influences on river hydrochemistry at Mengabang Telipot River, Peninsular Malaysia.

    Science.gov (United States)

    Koh, Mei Kee; Sathiamurthy, Edlic; Suratman, Suhaimi; Tahir, Norhayati Mohd

    2012-12-01

    Influences of river hydrodynamic behaviours on hydrochemistry (salinity, pH, dissolved oxygen saturations and dissolved phosphorus) were evaluated through high spatial and temporal resolution study of a sandbar-regulated coastal river. River hydrodynamic during sandbar-closed event was characterized by minor dependency on tidal fluctuations, very gradual increase of water level and continual low flow velocity. These hydrodynamic behaviours established a hydrochemistry equilibrium, in which water properties generally were characterized by virtual absence of horizontal gradients while vertical stratifications were significant. In addition, the river was in high trophic status as algae blooms were visible. Conversely, river hydrodynamic in sandbar-opened event was tidal-controlled and showed higher flow velocity. Horizontal gradients of water properties became significant while vertically more homogenised and with lower trophic status. In essence, this study reveals that estuarine sandbar directly regulates river hydrodynamic behaviours which in turn influences river hydrochemistry. PMID:22302401

  4. Environmental flow for Monsoon Rivers in India: The Yamuna River as a case study

    CERN Document Server

    Soni, Vikram; Singh, Diwan

    2013-01-01

    We consider the flows of Monsoon Rivers in India that will permit the river to perform all its natural functions. About 80% of the total flow for Indian rivers is during the monsoon and the remaining 20% is during the non monsoon period. By carrying out a case study of the river Yamuna in Delhi we find that at least 50% of the virgin monsoon (July to September) flow is required for the transport of the full spectrum of soil particles in the river sediment. A similar flow is needed for adequate recharge of the floodplain aquifers along river. For the non monsoon period (October to June) about 60% of the virgin flow is necessary to avoid the growth of still water algae and to support river biodiversity.

  5. 10 years After The Largest River Restoration Project In Northern Europe:Hydromorphological changes on multiple scales in River Skjern

    OpenAIRE

    Kristensen, Esben; Kronvang, Brian; Wiberg-Larsen, Peter; Thodsen, Hans; Nielsen, Carsten Brian; Amor, E.; Friberg, Nikolai; Pedersen, Morten Lauge; Baattrup-Pedersen, Annette

    2014-01-01

    The lower river Skjern (Denmark) historically contained a large variation in habitats and the river ran through large areas with wetlands, many backwaters, islands and oxbow lakes. During the 1960s the river was channelized and the wetland drained. A restoration during 2001–2002 transformed 19 km of channelized river into 26 km meandering river. The short-term effects of this restoration have previously been reported and for this study we revisited the river and with new data evaluated the lo...

  6. Sediment transport in two mediterranean regulated rivers.

    Science.gov (United States)

    Lobera, G; Batalla, R J; Vericat, D; López-Tarazón, J A; Tena, A

    2016-01-01

    Mediterranean climate is characterized by highly irregular rainfall patterns with marked differences between wet and dry seasons which lead to highly variable hydrological fluvial regimes. As a result, and in order to ensure water availability and reduce its temporal variability, a high number of large dams were built during the 20th century (more than 3500 located in Mediterranean rivers). Dams modify the flow regime but also interrupt the continuity of sediment transfer along the river network, thereby changing its functioning as an ecosystem. Within this context, the present paper aims to assess the suspended sediment loads and dynamics of two climatically contrasting Mediterranean regulated rivers (i.e. the Ésera and Siurana) during a 2-yr period. Key findings indicate that floods were responsible for 92% of the total suspended sediment load in the River Siurana, while this percentage falls to 70% for the Ésera, indicating the importance of baseflows on sediment transport in this river. This fact is related to the high sediment availability, with the Ésera acting as a non-supply-limited catchment due to the high productivity of the sources (i.e. badlands). In contrast, the Siurana can be considered a supply-limited system due to its low geomorphic activity and reduced sediment availability, with suspended sediment concentration remaining low even for high magnitude flood events. Reservoirs in both rivers reduce sediment load up to 90%, although total runoff is only reduced in the case of the River Ésera. A remarkable fact is the change of the hydrological character of the River Ésera downstream for the dam, shifting from a humid mountainous river regime to a quasi-invariable pattern, whereas the Siurana experiences the opposite effect, changing from a flashy Mediterranean river to a more constant flow regime below the dam.

  7. How integrated is river basin management?

    Science.gov (United States)

    Downs, Peter W.; Gregory, Kenneth J.; Brookes, Andrew

    1991-05-01

    Land and water management is increasingly focused upon the drainage basin. Thirty-six terms recently used for schemes of “integrated basin management” include reference to the subject or area and to the aims of integrated river basin management, often without allusion to the multiobjective nature. Diversity in usage of terms has occurred because of the involvement of different disciplines, of the increasing coherence of the drainage basin approach, and the problems posed in particular parts of the world. The components included in 21 different approaches are analyzed, and, in addition to showing that components related broadly to water supply, river channel, land, and leisure aspects, it is concluded that there are essentially five interrelated facets of integrated basin management that involved water, channel, land, ecology, and human activity. Two aspects not fully included in many previous schemes concern river channel changes and the dynamic integrity of the fluvial system. To clarify the terminology used, it is suggested that the term comprehensive river basin management should be used where a wide range of components is involved, whereas integrated basin management can signify the interactions of components and the dominance of certain components in the particular area. Holistic river basin management is advocated as a term representing an approach that is both fully comprehensive and integrated but also embraces the energetics of the river system and consideration of changes of river channels and of human impacts throughout the river system. The paradigm of working with the river can be extended to one of working with the river in the holistic basin context.

  8. American shad in the Columbia River

    Science.gov (United States)

    Petersen, J.H.; Hinrichsen, R.A.; Gadomski, D.M.; Feil, D.H.; Rondorf, D.W.

    2003-01-01

    American shad Alosa sapidissima from the Hudson River, New York, were introduced into the Sacramento River, California, in 1871 and were first observed in the Columbia River in 1876. American shad returns to the Columbia River increased greatly between 1960 and 1990, and recently 2-4 million adults have been counted per year at Bonneville Dam, Oregon and Washington State (river kilometer 235). The total return of American shad is likely much higher than this dam count. Returning adults migrate as far as 600 km up the Columbia and Snake rivers, passing as many as eight large hydroelectric dams. Spawning occurs primarily in the lower river and in several large reservoirs. A small sample found returning adults were 2-6 years old and about one-third of adults were repeat spawners. Larval American shad are abundant in plankton and in the nearshore zone. Juvenile American shad occur throughout the water column during night, but school near the bottom or inshore during day. Juveniles consume a variety of zooplankton, but cyclopoid copepods were 86% of the diet by mass. Juveniles emigrate from the river from August through December. Annual exploitation of American shad by commercial and recreational fisheries combined is near 9% of the total count at Bonneville Dam. The success of American shad in the Columbia River is likely related to successful passage at dams, good spawning and rearing habitats, and low exploitation. The role of American shad within the aquatic community is poorly understood. We speculate that juveniles could alter the zooplankton community and may supplement the diet of resident predators. Data, however, are lacking or sparse in some areas, and more information is needed on the role of larval and juvenile American shad in the food web, factors limiting adult returns, ocean distribution of adults, and interactions between American shad and endangered or threatened salmonids throughout the river. ?? 2003 by the American Fisheries Society.

  9. Trends in the occurrence of human and veterinary antibiotics in the sediments of the Yellow River, Hai River and Liao River in northern China

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Lijun [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Ying Guangguo, E-mail: guang-guo.ying@gig.ac.cn [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Zhao Jianliang [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Yang Jifeng [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Chemistry and Chemical Engineering Department, Hunan University of Arts and Science, Changde 415000 (China); Wang Li; Yang Bin; Liu Shan [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China)

    2011-07-15

    The occurrence of four classes of 17 commonly used antibiotics (including fluoroquinolones, tetracycline, sulfonamides, and macrolides) was investigated in the sediments of the Yellow River, Hai River and Liao River in northern China by using rapid resolution liquid chromatography-tandem mass spectrometry. Higher concentrations were detected for most antibiotics in the sediments of the Hai River than in the sediments of the other rivers. Norfloxacin, ofloxacin, ciprofloxacin and oxytetracycline in the three rivers were most frequently detected with concentrations up to 5770, 1290, 653 and 652 ng/g, respectively. High frequencies and concentrations of the detected antibiotics were often found in the downstream of large cities and areas influenced by feedlot and fish ponds. Good fitted linear regression equations between antibiotic concentration and sediment physicochemical properties (TOC, texture and pH) were also found, indicating that sediment properties are important factors influencing the distribution of antibiotics in the sediment of rivers. - Highlights: > Presence of four classes of commonly used antibiotics in the river sediments. > Higher concentrations in the Hai River than in the Liao River and Yellow River. > Norfloxacin, ofloxacin, ciprofloxacin and oxytetracycline most frequently detected. > High antibiotic concentrations often found in the downstream of large cities. > River sediments are an important reservoir of antibiotics. - Higher concentrations of selected antibiotics were determined in the sediments of the Hai River than in the Liao River and Yellow River.

  10. Hotspots within the Transboundary Selenga River Basin

    Science.gov (United States)

    Kasimov, Nikolay; Lychagin, Mikhail; Chalov, Sergey

    2013-04-01

    Gathering the efficient information on water pollution of transboundary river systems remains the crucial task in international water management, environmental pollution control and prevention health problems. Countries, located in the low parts of the river basins, depend on the water strategy and water use in the adjacent countries, located upstream. Surface water pollution is considered to be the most serious problem, facing the above-mentioned countries. Large efforts in terms of field measurement campaigns and (numerical) transport modeling are then typically needed for relevant pollution prediction and prevention. Russian rivers take inflow from 8 neighboring countries. Among them there are 2 developing economies - People Republic of China and Mongolia, which are located in water-scarce areas and thus solve their water-related problems through the consumption of international water. Negative change of water runoff and water quality in the foreign part of transboundary river is appeared inside Russian territory with more or less delay. The transboundary river system of Selenga is particularly challenging, being the biggest tributary of Lake Baikal which is the largest freshwater reservoir in the world. Selenga River contributes about 50 % of the total inflow into Baikal. It originates in the mountainous part of Mongolia and then drains into Russia. There are numerous industries and agricultural activities within the Selenga drainage basin that affect the water quality of the river system. Absence of the single monitoring system and predictive tools for pollutants transport in river system requires large efforts in understanding sources of water pollution and implemented data on the relevant numerical systems for the pollution prediction and prevention. Special investigations in the Selenga river basin (Mongolia and Russia) were done to assess hot spots and understand state-of-the art in sediment load, water chemistry and hydrobiology of transboundary systems

  11. Multiple Time Scale Analysis of River Runoff Using Wavelet Transform for Dagujia River Basin, Yantai, China

    Institute of Scientific and Technical Information of China (English)

    LIU Delin; LIU Xianzhao; LI Bicheng; ZHAO Shiwei; LI Xiguo

    2009-01-01

    Based on monOdy river runoff and meteorological data, a method of Morlet wavelet transform was used to analyze the multiple time scale characteristics of river runoffin the Dagnjia River Basin, Yantai City, Shandong Province. The results showed that the total annual river runoff in the Dagujia River Basin decreased significantly from 1966 to 2004, and the rate of decrease was 48×106m3/10yr, which was higher than the mean value of most rivers in China. Multiple time scale characteristics existed, which accounted for different aspects of the changes in annual river runoff, and the major periods of the runoff time series were identified as about 28 years, 14 years and 4 years with decreasing levels of fluctuation. The river runoff evolution process was controlled by changes in precipitation to a certain extent, but it was also greatly influenced by human activities. Also, for different time periods and scales, the impacts of climate changes and human activities on annual river runoff evolution occurred at the same time. Changes in the annual river runoffwere mainly associated with climate change before the 1980s and with human activities after 1981.

  12. An analysis of similarity of digital river networks with different resolutions in various river basins

    Science.gov (United States)

    Magome, J.; Masutani, K.; Ishidaira, H.

    2011-12-01

    In order to apply hydrological models and establish computer aided hydrological discharge nowcast eventually forecast system for large regions like Asian continent or whole world, accuracy of digital river network is one of the key issue to produce useful information. In this study, we propose and apply a method which analyses the similarity of digital river networks with different spatial resolutions. We use the coordinates and upstream catchment areas at major confluent points in order to represent the features of river networks. Turning counter- clockwise around the river network from the estuary, we arrange confluent points into one string. The sets of the one-dimensional data obtained from river networks are compared by using DP matching. A set of river networks with different scales ranging from 90 m to 20 km grids were developed based on this scaling algorithm (Masutani et al., 2006) using 90m HydroSHEDS. We evaluated the developed dataset using the proposed method to small to large rivers in Asian Regions (including Mekong River, Yellow River. etc.). A possibility of utilizing the proposed method was successfully shown. The proposed method and the river network dataset developed can provide better hydrological simulation with different grid scales with little effect.

  13. Reactor loops at Chalk River

    International Nuclear Information System (INIS)

    This report describes broadly the nine in-reactor loops, and their components, located in and around the NRX and NRU reactors at Chalk River. First an introduction and general description is given of the loops and their function, supplemented with a table outlining some loop specifications and nine simplified flow sheets, one for each individual loop. The report then proceeds to classify each loop into two categories, the 'main loop circuit' and the 'auxiliary circuit', and descriptions are given of each circuit's components in turn. These components, in part, are comprised of the main loop pumps, the test section, loop heaters, loop coolers, delayed-neutron monitors, surge tank, Dowtherm coolers, loop piping. Here again photographs, drawings and tables are included to provide a clearer understanding of the descriptive literature and to include, in tables, some specifications of the more important components in each loop. (author)

  14. River Basin Standards Interoperability Pilot

    Science.gov (United States)

    Pesquer, Lluís; Masó, Joan; Stasch, Christoph

    2016-04-01

    There is a lot of water information and tools in Europe to be applied in the river basin management but fragmentation and a lack of coordination between countries still exists. The European Commission and the member states have financed several research and innovation projects in support of the Water Framework Directive. Only a few of them are using the recently emerging hydrological standards, such as the OGC WaterML 2.0. WaterInnEU is a Horizon 2020 project focused on creating a marketplace to enhance the exploitation of EU funded ICT models, tools, protocols and policy briefs related to water and to establish suitable conditions for new market opportunities based on these offerings. One of WaterInnEU's main goals is to assess the level of standardization and interoperability of these outcomes as a mechanism to integrate ICT-based tools, incorporate open data platforms and generate a palette of interchangeable components that are able to use the water data emerging from the recently proposed open data sharing processes and data models stimulated by initiatives such as the INSPIRE directive. As part of the standardization and interoperability activities in the project, the authors are designing an experiment (RIBASE, the present work) to demonstrate how current ICT-based tools and water data can work in combination with geospatial web services in the Scheldt river basin. The main structure of this experiment, that is the core of the present work, is composed by the following steps: - Extraction of information from river gauges data in OGC WaterML 2.0 format using SOS services (preferably compliant to the OGC SOS 2.0 Hydrology Profile Best Practice). - Model floods using a WPS 2.0, WaterML 2.0 data and weather forecast models as input. - Evaluation of the applicability of Sensor Notification Services in water emergencies. - Open distribution of the input and output data as OGC web services WaterML, / WCS / WFS and with visualization utilities: WMS. The architecture

  15. Water Quality Data Analysis for Kanhan River

    Directory of Open Access Journals (Sweden)

    Snehal K. Kamble

    2014-08-01

    Full Text Available The Kanhan River originates from the high lands of Chindawara District and flows in south east direction for about 160 kms before it enters the state of Maharashtra near Raiwari village in Saoner Taluka of Nagpur District. Nagpur city is presently getting water for from two major sources namely Kanhan River (Head work located near village Juni Kamptee &Pench Dam (through Right Bank Canal with Lifting Point at Mahadula at 48.5 Km of canal. Samples were collected from seven major locations along the stretch of river. The samples were subjected to physicochemical analysis and performed during summer, rainy and winter seasons. The physicochemical parameters of the water samples includes pH, temperature, turbidity, conductivity (EC, suspended solids (SS, total dissolved solids (TDS, total solids (TS, dissolved oxygen (DO and biological oxygen demand (BOD. The water quality index (WQI is used to evaluate the quality of the river water for drinking in rainy, winter and summer season.The study was carried out to examine the change in the quality of the river water due to addition of human waste discharge, industrial waste discharge into river body and the seasonal variation in the physicochemical properties of the river.

  16. Tipping Points in Texas Rivers

    Science.gov (United States)

    Phillips, Jonathan

    2016-04-01

    Anticipating geomorphic tipping points requires that we learn from the past. Major geomorphic changes in coastal plain rivers of Texas resulting in river metamorphosis or regime shifts were identified, and the major driving factors determined. Nine fluvial tipping points were identified from contemporary observations, historical records, and Quaternary reconstructions. Two of the tipping points (between general aggrading and degrading valley states) are associated with reversals in a fundamental system control (sea-level). One (stable or aggrading vs. degrading channels) is associated with an abrupt change in sediment supply due to dam construction, and two others (changes from meandering to anastomosing channel patterns, and different anastomosis styles) are similarly related to changes in sediment supply and/or transport capacity, but with additional elements of historical contingency. Three tipping points are related to avulsions. One, from a regime dominated to reoccupation of former channels to one dominated by progradation into flood basins, is driven by progressive long term filling of incised valleys. Another, nodal avulsions, are driven by disturbances associated with tectonics or listric faults. The third, avulsions and related valley metamorphosis in unfilled incised valleys, is due to fundamental dynamical instabilities within the fluvial system. This synthesis and analysis suggests that geomorphic tipping points are sometimes associated with general extrinsic or intrinsic (to the fluvial system) environmental change, independent of any disturbances or instabilities. Others are associated with natural (e.g., tectonic) or human (dams) disturbances, and still others with intrinsic geomorphic instabilities. This suggests that future tipping points will be equally diverse with respect to their drivers.

  17. River Data Package for Hanford Assessments

    Energy Technology Data Exchange (ETDEWEB)

    Rakowski, Cynthia L.; Guensch, Gregory R.; Patton, Gregory W.

    2006-08-01

    This data package documents the technical basis for selecting physical and hydraulic parameters and input values that will be used in river modeling for Hanford assessments. This work was originally conducted as part of the Characterization of Systems Task of the Groundwater Remediation Project managed by Fluor Hanford, Inc. and revised as part of the Characterization of Systems Project managed by PNNL for DOE. The river data package provides calculations of flow and transport in the Columbia River system. The module is based on the legacy code for the Modular Aquatic Simulation System II (MASS2), which is a two-dimensional, depth-averaged model that provides the capability to simulate the lateral (bank-to-bank) variation of flow and contaminants. It simulates river hydrodynamics (water velocities and surface elevations), sediment transport, contaminant transport, biotic transport, and sediment-contaminant interaction, including both suspended sediments and bed sediments. This document presents the data assembled to run the river module components for the section of the Columbia River from Vernita Bridge to the confluence with the Yakima River. MASS2 requires data on the river flow rate, downstream water surface elevation, groundwater influx and contaminants flux, background concentrations of contaminants, channel bathymetry, and the bed and suspended sediment properties. Stochastic variability for some input parameters such as partition coefficient (kd) values and background radionuclide concentrations is generated by the Environmental Stochastic Preprocessor. River flow is randomized on a yearly basis. At this time, the conceptual model does not incorporate extreme flooding (for example, 50 to 100 years) or dam removal scenarios.

  18. Construction of river transfer models for MOGRA

    International Nuclear Information System (INIS)

    Two dynamic compartment models were constructed as basic river transfer models for MOGRA (Migration Of GRound Additions) - an environmental load effect predicting code developed by JAERI (Japan Atomic Energy Research Institute). One model is for the river transfer of one component where particulate form and dissolved form are in equilibrium. The other model is structured for the river transfer of two components when the particulates and dissolved forms are treated individually by separate compartmentalization. In each model the river sediment is set in a compartment. The sedimentation of particulate form and resuspension of radionuclides in the river sediment are taken into account. Modeling a river system with MOGRA is done by connecting one of these models to match the system. To verify the analysis function of the constructed models, calculation conditions were set using data of 137Cs concentration obtained from Kuji River, Japan. The length of the river was set to 50 km and was divided into 5 equal parts. The inflow of 137Cs and parameter values concerning transfer velocities were set differently in case of normal flow rate and high flow rate. In calculation, high flow rate caused by rain was supposed to occur after a period to normal flow rate. There is almost no difference seen between these models when sedimentation velocity is low. There is apparent difference when sedimentation velocity is high. It is concluded that in selecting and applying models to real environment enough consideration should be taken as to which system to be assessed and what the purpose is. To make it possible to analyze various river systems for various purposes, models need to be developed, for example, compartmentalizing the watershed. The data needed will be collected with it. (author)

  19. Raft River Geothermal Aquaculture Experiment. Phase II

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, D.K.; Rose, F.L.; Kent, J.C.; Watson, L.R.; Sullivan, J.F.

    1979-08-01

    Channel catfish, tilapia and Malaysian prawns were cultured directly in geothermal water for approximately seven months at the Department of Energy, Raft River Geothermal Site, to evaluate the organisms throughout a grow-out cycle. Parameters evaluated included survival, growth, bioaccumulation of metals and fluoride, collagen synthesis, and bone calcium levels. Growth at Raft River was slightly lower than at a companion commercial facility at Buhl, Idaho, but was attributed to facility differences rather than an adverse impact of geothermal water. No significant differences were recorded between Raft River and Buhl fish for bone calcium or collagen concentrations. No significant accumulation of heavy metals by fish or prawns was recorded.

  20. Rapid River Hatchery - Spring Chinook, Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Watson, M.

    1996-05-01

    This report presents the findings of the independent audit of the Rapid River Hatchery (Spring Chinook). The hatchery is located in the lower Snake River basin near Riggins Idaho. The hatchery is used for adult collection, egg incubation, and rearing of spring chinook. The audit was conducted in April 1996 as part of a two-year effort that will include 67 hatcheries and satellite facilities located on the Columbia and Snake River system in Idaho, Oregon, and Washington. The hatchery operating agencies include the US Fish and Wildlife Service, Idaho Department of Fish and Game, Oregon Department of Fish and Wildlife, and Washington Department of Fish and Wildlife.

  1. Rapid River Hatchery - Spring Chinook, Final Report

    International Nuclear Information System (INIS)

    This report presents the findings of the independent audit of the Rapid River Hatchery (Spring Chinook). The hatchery is located in the lower Snake River basin near Riggins Idaho. The hatchery is used for adult collection, egg incubation, and rearing of spring chinook. The audit was conducted in April 1996 as part of a two-year effort that will include 67 hatcheries and satellite facilities located on the Columbia and Snake River system in Idaho, Oregon, and Washington. The hatchery operating agencies include the US Fish and Wildlife Service, Idaho Department of Fish and Game, Oregon Department of Fish and Wildlife, and Washington Department of Fish and Wildlife

  2. Lindane residues in fish inhabiting Nigerian rivers

    International Nuclear Information System (INIS)

    Analysis for residues of lindane in fish collected from various rivers close to rice agroecosystems showed that the concentrations of lindane ranged from none detectable to 3.4 mg kg-1. Fish from rivers where strict regulations prohibits its use had no detectable lindane residues while appreciable amounts of lindane were found in fish were such restriction was not enforced with the variation attributed to the extent of use of lindane in the area of contamination. The investigation confirms that the use of lindane in rice production in Nigeria can cause the contamination of fish in nearby rivers. (author). 16 refs, 2 tab

  3. Managing Fine Sediment in Regulated Rivers

    Science.gov (United States)

    Schmidt, J. C.

    2015-12-01

    A paradigm useful in managing dams and diversions is that the combined effects of changing flow regime and sediment supply perturb regulated rivers into sediment deficit or sediment surplus. In the U.S. Southwest, large dams constructed on interregional rivers typically create sediment deficit segments >100 km long. Further downstream, sediment surplus may occur if desert tributaries deliver sufficient amounts of fine sediment, such as parts of the Rio Grande, lower Green River, and Colorado River delta. Sediment surplus also occurs on most smaller regional rivers. The protocols for managing rivers perturbed into sediment deficit have been refined for the Colorado River downstream from Glen Canyon Dam but are nonetheless challenged by externally determined water-supply agreements that require annual water deliveries that sometimes occur when there has been little tributary resupply. Virtually all of the naturally supplied sand to the depleted, 100-km long Marble Canyon comes from the Paria River. The sand delivery rate since 2012 was sufficiently large to trigger short-duration controlled floods under the High Flow Experiment (HFE) Protocol. The sand mass balance of Marble Canyon since 2012 when the HFE Protocol was adopted was positive due to the combination of relatively large sand delivery from the Paria River and average total annual flows. Large total annual flows have the potential to export large amounts of sand and create a negative sand mass balance. Despite the challenge of managing a scarce and highly variable sand supply and occasional years of large reservoir releases, the long-term (2006-2015) sand mass balance for the upstream half of Marble Canyon is indeterminant and is positive for the downstream half of Marble Canyon. The apparent success of managing sand in Grand Canyon under deficit conditions suggests that fine sediment management protocols might be developed for other regulated rivers. Implementation would require establishment of networks of

  4. Aquatic macroinvertebrates of the Jablanica river, Serbia

    Directory of Open Access Journals (Sweden)

    Stefanović Katarina S.

    2009-01-01

    Full Text Available Research on the community of aquatic macroinvertebrates was carried out during 2005 and 2006 at four sampling sites along the Jablanica River, a right-hand tributary of the Kolubara River. Fifty-seven taxa were recorded in the course of the investigation. The most diverse group was Ephemeroptera, followed by Trichoptera and Plecoptera. Members of the Rhitrogena semicolorata group were the most abundant. Our results could be the basis for evaluation of the influence of damming of the Jablanica River on the status of its water and can serve as a model for studying the influ­ence of hydromorphological degradation of aquatic ecosystems.

  5. The law of the river: Policy expression

    International Nuclear Information System (INIS)

    The need to accurately represent the law of the Colorado River has heretofore precluded the use of any general purpose river basin simulation model. In order to overcome the inflexibility associated with policies coded directly into a model, a new approach for river basin simulation modeling has been developed. The new approach allows the user to capture the operating policy in a series of policy statements separate from the basic simulation model. These statements are accessible without writing code and may easily be modified to explore policy alternatives

  6. Seepage Investigation for Selected River Reaches in the Chehalis River Basin, Washington

    Science.gov (United States)

    Ely, D. Matthew; Frasl, Kenneth E.; Marshall, Cameron A.; Reed, Fred

    2008-01-01

    A study was completed in September 2007 in the Chehalis River basin to determine gain or loss of streamflow by measuring discharge at selected intervals within various reaches along the Chehalis River and its tributaries. Discharge was measured at 68 new and existing streamflow sites, where gains and losses were determined for 36 stream reaches. Streamflow gains were measured for 22 reaches and losses were measured for 13 reaches. No gain or loss was measured at the Chehalis River between the Newaukum and Skookumchuck Rivers. The Chehalis River exhibited a pattern of alternating gains and losses as it entered the area of wide, gentle relief known as the Grand Mound Prairie. The general pattern of tributary ground- and surface-water interaction was discharge to streams (gaining reaches) in the upper reaches and discharge to the ground-water system (losing reaches) as the tributaries entered the broad, flat Chehalis River valley.

  7. River monitoring from satellite radar altimetry in the Zambezi River basin

    DEFF Research Database (Denmark)

    Michailovsky, Claire Irene B.; McEnnis, S.; Berry, P. A. M.;

    2012-01-01

    Satellite radar altimetry can be used to monitor surface water levels from space. While current and past altimetry missions were designed to study oceans, retracking the waveforms returned over land allows data to be retrieved for smaller water bodies or narrow rivers. The objective of this study...... is the assessment of the potential for river monitoring from radar altimetry in terms of water level and discharge in the Zambezi River basin. Retracked Envisat altimetry data were extracted over the Zambezi River basin using a detailed river mask based on Landsat imagery. This allowed for stage measurements...... to be obtained for rivers down to 80 m wide with an RMSE relative to in situ levels of 0.32 to 0.72 m at different locations. The altimetric levels were then converted to discharge using three different methods adapted to different data-availability scenarios: first with an in situ rating curve available...

  8. Integrated ecological modelling for decision support in river management: a lowland river case study (Cauca river in Colombia)

    OpenAIRE

    Holguin Gonzalez, Javier; Goethals, Peter; Galvis, Alberto

    2010-01-01

    Several practical concepts and software systems have been recently developed in the issue of environmental decision support. However, the application of ecological modelling approaches that integrate hydrodynamic, physical-chemical, and biological components sub-models for predicting macroinvertebrates in rivers, is rather limited and hardly described in literature. The Cauca river is one of most severe cases of contamination for domestic and industrial wastewater discharges in Colombia. One ...

  9. Merging imagery and models for river current prediction

    Science.gov (United States)

    Blain, Cheryl Ann; Linzell, Robert S.; McKay, Paul

    2011-06-01

    To meet the challenge of operating in river environments with denied access and to improve the riverine intelligence available to the warfighter, advanced high resolution river circulation models are combined with remote sensing feature extraction algorithms to produce a predictive capability for currents and water levels in rivers where a priori knowledge of the river environment is limited. A River Simulation Tool (RST) is developed to facilitate the rapid configuration of a river model. River geometry is extracted from the automated processing of available imagery while minimal user input is collected to complete the parameter and forcing specifications necessary to configure a river model. Contingencies within the RST accommodate missing data such as a lack of water depth information and allow for ensemble computations. Successful application of the RST to river environments is demonstrated for the Snohomish River, WA. Modeled currents compare favorably to in-situ currents reinforcing the value of the developed approach.

  10. Conservatives and champions: river managers and the river restoration discourse in the United Kingdom

    OpenAIRE

    Adams, William M.; Martin R Perrow; Angus Carpenter

    2004-01-01

    We discuss two contrasting discourses of environmental management for the management of rivers and floodplain environments in the United Kingdom. Through the 1990s a long-established flood defence discourse gave way to a new discourse of river and floodplain restoration. We draw on qualitative interviews with river managers to set out these discourses, and consider the engagement between them. We consider particularly the way in which flood defence engineers have resisted and gradually been w...

  11. Conservation status and distribution pattern of the Indus River Dolphin in River Beas, India

    OpenAIRE

    MOHD SHAHNAWAZ KHAN; ANJANA PANT

    2014-01-01

    Khan MS, Pant A. 2014. Conservation status and distribution pattern of the Indus River Dolphin in River Beas, India. Biodiversitas 15: 73-77. Decline in the populations of Indus River Dolphins Platanista gangetica minor throughout its range of distribution and a perception that it is a 'keystone species' for riverine ecosystem stirred the idea of proposed study. Deficiency of baseline data on its distribution and ecology is a major constraint that this (only known sub-population in India) spe...

  12. Suitability Evaluation of River Bank Filtration along the Second Songhua River, China

    OpenAIRE

    Lixue Wang; Xueyan Ye; Xinqiang Du

    2016-01-01

    The Second Songhua River is the biggest river system in Jilin Province, China. In recent years, the rapid economic development in this area has increased the prominence of water resources and water-related environmental problems; these include surface water pollution and the overexploitation of groundwater resources. Bank infiltration on the floodplains of the Second Songhua River is an important process of groundwater-surface water exchange under exploitation conditions. Understanding this p...

  13. EVALUATION OF WATER AND SEDIMENT QUALITIES AT RIVER MOUTHS IN THE HAIHE RIVER SYSTEM

    Institute of Scientific and Technical Information of China (English)

    Cheng LIU; Zhaoyin WANG; Yun HE; Dongsheng CHENG

    2007-01-01

    Water and sediment qualities are studied by analyzing samples taking from the mouths of the Haihe, Duliujian, New Ziya and Beipai rivers in the Haihe river basin in north China in 2005 and 2001, in order to find the changes of water and sediment pollutions. The concentrations of heavy metals, arsenic, total nitrogen (TN) and total phosphorus (TP) are analyzed and results have been compared for the two times. The in-situ measurement for Dissolved Oxygen (DO) and Sediment Oxygen Demand (SOD) rates were carried at the Haihe and Duliujian river mouths in 2006. The results show that the waters of the 4 river mouths are still seriously polluted, though much improved in the case of the Haihe and Duliujian rivers. The main pollutants are TP and TN in the New Ziya and Beipai rivers and mercury (Hg) at all 4 river mouths. Compared with those in 2001, the concentrations of almost all metals and arsenic in the 4 river mouths have decreased. Water quality at Haihe and Duliujian shows an improving trend, while the water quality at Beipai is similar to that of 2001. In contrast, water at the New Ziya river mouth is more severely polluted. The sediments in the 4 river mouths are not seriously polluted by heavy metals but are polluted by nitrogen and phosphorus. Most of the pollutant contents in the sediments show little change between 2001 and 2005. The in-situ DO and SOD measurement shows that the waters at the Haihe river mouth is in the state of oxygen depletion, and SOD is important consumer of DO at the river mouths. The overall analysis shows that increasing water pollution and eutrophication in waters far from cities are ongoing causes of concern.

  14. 50 CFR Table 3 to Part 226 - Hydrologic Units Containing Critical Habitat for Snake River Sockeye Salmon and Snake River...

    Science.gov (United States)

    2010-10-01

    ... Habitat for Snake River Sockeye Salmon and Snake River Spring/Summer and Fall Chinook Salmon 3 Table 3 to... Part 226—Hydrologic Units Containing Critical Habitat for Snake River Sockeye Salmon and Snake River... Snake—Asotin 17060103 17060103 17060103 Upper Grande Ronde 17060104 Wallowa 17060105 Lower Grande...

  15. 33 CFR 165.802 - Lower Mississippi River, vicinity of Old River Control Structure-Safety Zone.

    Science.gov (United States)

    2010-07-01

    ... of Old River Control Structure-Safety Zone. 165.802 Section 165.802 Navigation and Navigable Waters... Guard District § 165.802 Lower Mississippi River, vicinity of Old River Control Structure—Safety Zone... permission from the Captain of the Port, New Orleans. The resident engineer at Old River Control...

  16. Taking the Pulse of a River System: Research on the Upper Mississippi River System

    Science.gov (United States)

    Sauer, Jennifer; Johnson, Barry

    2009-01-01

    Mark Twain raved about the Mississippi River basin as, 'the body of the Nation'. The 'upper body', upstream of the confluence with the Ohio River, includes commercially navigable reaches and branching tributaries that are recreationally and environmentally important. Together they feed and shelter an array of fish and wildlife in their flowing channels, floodplain lakes, backwaters, wetlands, and floodplain forests. Effective river management requires knowledge about factors controlling the dynamics and interactions of important ecosystem components. The Long Term Resource Monitoring Program (LTRMP) is the prized diagnostic tool in the Environmental Management Program for the Upper Mississippi River System that provides critical information about the status and trends of key environmental resources.

  17. Trace elements and radionuclides in the Connecticut River and Amazon River estuary

    International Nuclear Information System (INIS)

    The Connecticut River, its estuary, and the Amazon River estuary were studied to elucidate some of the processes which control river water chemistry and the flux of elements to the sea. The approach taken was to identify inputs to the Connecticut River and to investigate geochemical processes which modify the dissolved load. The form and quantity of nuclides which are in turn supplied to the estuary are altered by processes unique to that transition zone to the ocean. The Connecticut River estuary was sampled on a seasonal basis to investigate the role of the estuary in controlling the flux of elements to the sea. The knowledge gained from the Connecticut River study was applied to the quantitatively more significant Amazon River estuary. There a variety of samples were analyzed to understand the processes controlling the single greatest flux of elements to the Atlantic Ocean. The results indicate that estimates of the total flux of nuclides to the oceans can best be calculated based on groundwater inputs. Unless significant repositories for nuclides exist in the river-estuarine system, the groundwater flux of dissolved nuclides is that which will eventually be delivered to the ocean despite the reactions which were shown to occur in both rivers and estuaries. 153 references, 63 figures, 28 tables

  18. The Three Colorado Rivers: Comparing the Physical, Legal, and Economic Allocation of a Shared River

    Science.gov (United States)

    Rushforth, R.; Ruddell, B. L.

    2015-12-01

    : For many rivers, the legal allocation of surface water was settled decades ago. The process of apportioning surface water between multiple stakeholders is an arduous process with opposing interests competing for scarce resources. The political capital spent initially allocating a river often cannot be regained, stymieing future attempts for re-allocation. The Colorado River Compact (Compact), signed in 1922, has been "the law of the river" for over 90 years. Since its signing, the Colorado River Basin (CRB) population has increased tenfold, while average river flows have decreased due to threats unforeseeable to Compact signers, such as global climate change. Water sharing agreements, like the Compact, legally re-allocate physical river flows; however, water is increasingly shared through trade rather than aqueducts. Virtual water, or the water embodied by a good or service, is a trade adaption to resource scarcity, namely water and land. This study presents findings of a virtual water complement to the Compact. The goal of this study is to determine how the legal allocation of physical water resources are re-allocated as virtual water via economic trade in a shared river basin. Results are presented by at the sub-basin, state, and county-level, showing the geographic origin and destination of virtual water from CRB states and the Upper and Lower basins. A water stress index is calculated to show the indirect water stress of Colorado River water resources and network statistics are employed to rank the importance of virtual water sources in the CRB.

  19. Persistent organochlorine residues in sediments of Haihe River and Dagu Drainage River in Tianjin, China

    Institute of Scientific and Technical Information of China (English)

    DING Hui; LI Xin-gang; LIU Hun; WANG Jun; SHEN Wei-ran; SUN Yi-chao; SHAO Xiao-long

    2005-01-01

    Persistent organochlorine compounds were analyzed by means of GC-ECD in surface sediment samples from two selected rivers in Tianjin, Haihe River and Dagu Drainage River. A total of 16 surface sediment sites were selected along the both rivers. The frequency of detection of T-HCH and T-DDT in sediment samples both was up to 100%, which illustrated that the contamination of HCH and DDT was widespread in Haihe and Dagu Drainage Rivers. Results indicated that the concentrations of vadous pesticides in sediments from Haihe River were in the range of 3.30-75.96 ng/g dw for T-HCH and 1.57-211.57 ng/g dw for T-DDT. Compared with Haihe River,Dagu Drainage River was contaminated by HCHs and DDTs along the all locations and the values of T-HCH and T-DDT residues in sediments ranged from 2.30 to 124.61 ng/g dw and from 11.28 to 237.30 ng/g dw, respectively. The possible pollution sources were analyzed through monitoring results of organochlorine pesticides(OCPs) residues in sediments from the two rivers. The investigation also indicated that HCH was still used as pesticide in Tianjin partial area.

  20. Contribution of River Mouth Reach to Sediment Load of the Yangtze River

    Directory of Open Access Journals (Sweden)

    C. Wang

    2015-01-01

    Full Text Available This paper examined the sediment gain and loss in the river mouth reach of the Yangtze River by considering sediment load from the local tributaries, erosion/accretion of the river course, impacts of sand mining, and water extraction. A quantitative estimation of the contribution of the river mouth reach to the sediment load of the Yangtze River was conducted before and after impoundment of the Three Gorges Dam (TGD in 2003. The results showed that a net sediment load loss of 1.78 million ton/yr (Mt/yr occurred from 1965 to 2002 in the study area. The contribution of this reach to the sediment discharge into the sea is not as high as what was expected before the TGD. With impoundment of the TGD, channel deposition (29.90 Mt/yr and a net sediment loss of 30.89 Mt/yr occurred in the river mouth reach from 2003 to 2012. The river mouth reach has acted as a sink but not a source of sediment since impoundment of the TGD, which has exacerbated the decrease in sediment load. Technologies should be advanced to measure changes in river channel morphology, as well as in water and sediment discharges at the river mouth reach.