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Sample records for letaba river south

  1. Steatitis in wild sharptooth catfish, Clarias gariepinus (Burchell), in the Olifants and lower Letaba Rivers in the Kruger National Park, South Africa.

    Science.gov (United States)

    Huchzermeyer, K D A; Govender, D; Pienaar, D J; Deacon, A R

    2011-07-01

    Large numbers of adult Nile crocodiles, Crocodylus niloticus (Laurenti), died from pansteatitis during autumn and winter 2008 in the lower Letaba and Olifants River gorge in the Kruger National Park, South Africa. Consequently, the health status of fish from these waters was investigated. The study presents the pathological findings in fish inhabiting these rivers within the boundaries of the Park. Changes typical of steatitis were diagnosed in many of the larger specimens of sharptooth catfish, Clarias gariepinus (Burchell), caught within the Olifants River gorge. These fish carried large amounts of mesenteric fat with characteristic small brown granulomata within the adipose tissue. Necrosis and inflammation of the adipose tissues, with characteristic ceroid accumulation within the resultant granulomata and the associated aggregation of ceroid-containing macrophages, were demonstrated histologically and were typical of steatitis. Other changes included mild thickening and pallor of the gill tissues and swollen, orange, fatty livers. Focal hepatic lipidosis was demonstrated histologically, and special stains revealed storage of large amounts of iron in the livers. Blood smears revealed chromatin clumping in erythrocyte nuclei and nuclear and cell membrane irregularities. This is the first record of steatitis in wild-caught C. gariepinus.

  2. The contemporary geomorphology of the Letaba River in the Kruger National Park

    Directory of Open Access Journals (Sweden)

    B.P. Moon

    2001-07-01

    Full Text Available The Letaba River drains part of Northern Province in north-east South Africa. Its catchment has been modified significantly by human activity which has affected the flow regime; it experiences only ephemeral flows through the Kruger National Park to its confluence with the Olifants River. Although the Letaba is similar to the other rivers in the Kruger National Park in that it displays some bedrock influenced channel features, increased sediment delivery from the degraded catchment upstream has resulted in extensive alluviation within the channel. Sections of channel flowing over bedrock with no sediment covering are rare, and the river comprises a series of channel types: mixed anastomosing, alluvial braided, mixed pool-rapid and alluvial single thread. Each is characterised by a different combination of morphological units which relate to the degree of alluviation in the channel. These channel types are described in detail and inferences are made concerning their formation and maintenance from field observation and measurement.

  3. The vegetation and floristics of the Letaba exclosures, Kruger National Park, South Africa

    Directory of Open Access Journals (Sweden)

    Frances Siebert

    2010-03-01

    Full Text Available The construction of exclosures along two of the most important rivers in the Kruger National Park was done to investigate how patterns of spatial and temporal heterogeneity of the riparian zone is affected by fire, flood and herbivory. To assist this research programme, vegetation surveys were conducted within exclosures along the Letaba River to classify and map the vegetation of the area. The history and experimental design of the Letaba exclosures are similar to that of the Nkhuhlu exclosures along the Sabie River, which is directly related to questions surrounding elephant management. The main difference between the Nkhuhlu and Letaba exclosures is local heterogeneity, since the latter lies within the Mopaneveld, which is floristically and physiognomically much more homogenous than the vegetation of the southern Kruger National Park. Nevertheless, four plant communities, eight sub-communities and six variants were recognised and mapped for the Letaba exclosures. The vegetation description was done in relation to prevailing soil forms, differences in species richness, diversity and community structure, and therefore should serve as a basis for further detailed and broad-based botanical studies. Vegetation mapping was done to sub-community level and, where possible, to variant level. As expected in Mopaneveld vegetation, the plant communities could broadly be related to soil types, although smaller-scale variations correspond to soil moisture availability because the Mopaneveld is considered ‘event-driven’, especially in the herbaceous layer.Conservation implications: Floristic surveying and vegetation mapping of a long-term monitoring site, such as the Letaba exclosures, is seen as a baseline inventory to assist natural resource management. Linking mapping units to biodiversity strengthens the understanding needed to maintain biodiversity in all its natural facets and fluxes.

  4. Fish and other faunal remains from a Late Iron Age site on the Letaba River, Kruger National Park

    Directory of Open Access Journals (Sweden)

    Ina Plug

    1991-09-01

    Full Text Available Fish remains from Late Iron Age sites in the Transvaal are relatively scarce. It seems as if the people did not utilize the riverine resources extensively. Therefore the unique assemblage of large numbers of fish bones on a Late Iron Age site, provides some insight into the fish population of a section of the Letaba River a few hundred years ago. The presence of other faunal remains provides some information on prehistoric utilization of the environment in general. Hunting strategies and aspects of herding can also be deduced from the faunal remains.

  5. Effect of water use by smallholder farms in the Letaba basin

    NARCIS (Netherlands)

    Querner, E.P.; Froebrich, J.; Clercq, de Willem; Jovanovic, Nebo

    2016-01-01

    For the Letaba basin situated in the South African part of the Limpopo basin, a hydrological study was carried out in order to quantify the effect of smallholder farming on river flows. Important was to study the consequences of improved agricultural systems on the river flows, in particular for the

  6. Natural mortality amoung four common ungulate species on Letaba Ranch, Limpopo Province, South Africa

    Directory of Open Access Journals (Sweden)

    H.P. Cronje

    2002-12-01

    Full Text Available Five years of mortality data of impala Aepyceros melampus, blue wildebeest Connochaetes taurinus, buffalo Syncerus caffer and kudu Tragelaphus strepsiceros have been used to describe the minimum mortality profiles of the respective species in an open savanna system with the full compliment of predators. Predation is the principle cause of natural mortalities on the study site, Letaba Ranch, which is adjacent to the Kruger National Park. The principle cause of impala mortality are leopards Panthera pardus and wild dogs Lycaon pictus. Lion Panthera leo were major contributors to the mortality of wildebeest and buffalo. Anthrax Bacillus anthracis was the main cause of kudu mortality.

  7. Case-control study to determine whether river water can spread tetracycline resistance to unexposed impala (Aepyceros melampus) in Kruger National Park (South Africa).

    Science.gov (United States)

    Mariano, V; McCrindle, C M E; Cenci-Goga, B; Picard, J A

    2009-01-01

    A case-control study was performed in the Kruger National Park (KNP), South Africa, to find out whether impala (Aepyceros melampus) were more likely to harbor tetracycline-resistant Escherichia coli (TREC) in their feces when they drank from rivers that contained these bacteria than when they drank from rivers that were uncontaminated with TREC. The following five perennial rivers were selected: the Crocodile, the Letaba, the Olifants, the Sabie, and the Sand. Samples of river water (n = 33) and feces (n = 209), collected at 11 different sites, were cultured for E. coli. The resulting colonies were screened for tetracycline resistance by use of the Lederberg replica plating method (breakpoint, 4 mg/liter). A resistant and/or a susceptible isolate was then selected from each sample and subjected to the CLSI MIC broth microdilution test for tetracyclines. Among the 21 water specimens contaminated by E. coli, 19.05% (n = 4) were found to be resistant by the MIC method (breakpoint, >/=8 mg/liter). This led to the Crocodile, Olifants, and Letaba rivers being classified as TREC positive. Among the 209 impala feces sampled, 191 were positive for the presence of E. coli (91.38%). Within these (n = 191), 9.95% (n = 19) of the isolates were shown to be TREC by the MIC method. It was found that 1.11% (n = 1) of the E. coli isolates cultured from the feces of the control group (n = 90) were TREC, in comparison with 17.82% (n = 18) of those in feces from the exposed group (n = 101). The calculation of the odds ratio showed that impala drinking from TREC-contaminated rivers were 19.3 (2.63 to 141.69) times more likely to be infected with TREC than were unexposed impala. This is a significant finding, indicating that surface water could be a possible source of antimicrobial resistance in naïve animal populations and that impala could act as sentinels for antimicrobial resistance.

  8. Sprague River Oregon Centerline South 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 U.S....

  9. Sprague River Oregon Centerline South 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 U.S....

  10. Sprague River Oregon Centerline South Fork 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 U.S....

  11. Sprague River Oregon Centerline South 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 U.S....

  12. Sprague River Oregon Centerline South Fork 2005

    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 U.S....

  13. South Fork Holston River basin 1988 biomonitoring

    Energy Technology Data Exchange (ETDEWEB)

    Saylor, C.F.; Ahlstedt, S.A.

    1990-06-01

    There is concern over the effects of shifts in land use use practices on the aquatic fauna of streams in the South Fork Holston River basin in northwestern North Carolina and southwestern Virginia. Trout reproduction has noticeably declined in the Watauga River subbasin. The Watauga River and Elk River subbasins have been subjected to commercial and resort development. The Middle fork Holston River and the upper South Fork Holston River subbasins have been affected by agricultural and mining activities, respectively (Cox, 1986). To aid reclamation and management of the South Fork Holston basin, Tennessee Valley Authority (TVA) biologists conducted biomonitoring--including index of biotic integrity and macroinvertebrate sampling--on the Middle Fork Holston, South Fork Holston, Watauga, and Elk Rivers to assess cumulative impairment related to changes in habitat and pollutant loading in these subbasins. Biomonitoring can detect environmental degradation, help document problem areas, and assist in development of strategies for managing water quality. This report discusses the methods and materials and results of the biomonitoring of South Fork Holston River Basin. 13 refs., 5 figs., 12 tabs.

  14. Ecological flow requirements for South African rivers

    CSIR Research Space (South Africa)

    Ferrar, AA

    1989-01-01

    Full Text Available This document contains the proceedings of a workshop which was convened to debate the ecological flow requirements of South African rivers. Topics which are discussed include the influence of weirs and impoundments, the quantity requirements...

  15. Studies of mineralization in South African rivers

    CSIR Research Space (South Africa)

    Hall, GC

    1978-03-01

    Full Text Available Several South African rivers are polluted by mineral salts of diffuse source. This pollution can be related to geological phenomena and to irrigation practices. Mineralization is problematic in that it can render surface waters unsuitable...

  16. 33 CFR 117.751 - Shark River (South Channel).

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Shark River (South Channel). 117.751 Section 117.751 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.751 Shark River...

  17. South Fork Clearwater River Habitat Enhancement, Nez Perce National Forest.

    Energy Technology Data Exchange (ETDEWEB)

    Siddall, Phoebe

    1992-04-01

    In 1984, the Nez Perce National forest and the Bonneville Power Administration entered into a contractual agreement which provided for improvement of spring chinook salmon and summer steelhead trout habitat in south Fork Clearwater River tributaries. Project work was completed in seven main locations: Crooked River, Red River, Meadow Creek Haysfork Gloryhole, Cal-Idaho Gloryhole, Fisher Placer and Leggett Placer. This report describes restoration activities at each of these sites.

  18. Long-term solar activity influences on South American rivers

    OpenAIRE

    Mauas, Pablo; Buccino, Andrea P.; Flamenco, Eduardo

    2010-01-01

    River streamflows are excellent climatic indicators since they integrate precipitation over large areas. Here we follow up on our previous study of the influence of solar activity on the flow of the Parana River, in South America. We find that the unusual minimum of solar activity in recent years have a correlation on very low levels in the Parana's flow, and we report historical evidence of low water levels during the Little Ice Age. We also study data for the streamflow of three other river...

  19. 76 FR 11679 - Drawbridge Operation Regulation; Shark River (South Channel), Belmar, NJ

    Science.gov (United States)

    2011-03-03

    ... SECURITY Coast Guard 33 CFR Part 117 Drawbridge Operation Regulation; Shark River (South Channel), Belmar... operation of the S71 Bridge across Shark River (South Channel), mile 0.8, at Belmar, NJ. The deviation is... INFORMATION: The S71 Bridge, a bascule lift drawbridge, across Shark River (South Channel), at mile 0.8,...

  20. 77 FR 70372 - Drawbridge Operation Regulation; Shark River (South Channel), Avon Township, NJ

    Science.gov (United States)

    2012-11-26

    ... SECURITY Coast Guard 33 CFR Part 117 RIN 1625-AA09 Drawbridge Operation Regulation; Shark River (South..., across Shark River (South Channel) at Avon Township, NJ. The existing regulation contains a drawbridge... Transportation (NJDOT) to replace the existing bascule bridge, which carries S35 over Shark River (South...

  1. Mercury Loads in the South River and Simulation of Mercury Total Maximum Daily Loads (TMDLs) for the South River, South Fork Shenandoah River, and Shenandoah River: Shenandoah Valley, Virginia

    Science.gov (United States)

    Eggleston, Jack

    2009-01-01

    Due to elevated levels of methylmercury in fish, three streams in the Shenandoah Valley of Virginia have been placed on the State's 303d list of contaminated waters. These streams, the South River, the South Fork Shenandoah River, and parts of the Shenandoah River, are downstream from the city of Waynesboro, where mercury waste was discharged from 1929-1950 at an industrial site. To evaluate mercury contamination in fish, this total maximum daily load (TMDL) study was performed in a cooperative effort between the U.S. Geological Survey, the Virginia Department of Environmental Quality, and the U.S. Environmental Protection Agency. The investigation focused on the South River watershed, a headwater of the South Fork Shenandoah River, and extrapolated findings to the other affected downstream rivers. A numerical model of the watershed, based on Hydrological Simulation Program-FORTRAN (HSPF) software, was developed to simulate flows of water, sediment, and total mercury. Results from the investigation and numerical model indicate that contaminated flood-plain soils along the riverbank are the largest source of mercury to the river. Mercury associated with sediment accounts for 96 percent of the annual downstream mercury load (181 of 189 kilograms per year) at the mouth of the South River. Atmospherically deposited mercury contributes a smaller load (less than 1 percent) as do point sources, including current discharge from the historic industrial source area. In order to determine how reductions of mercury loading to the stream could reduce methylmercury concentrations in fish tissue below the U.S. Environmental Protection Agency criterion of 0.3 milligrams per kilogram, multiple scenarios were simulated. Bioaccumulation of mercury was expressed with a site-specific exponential relation between aqueous total mercury and methylmercury in smallmouth bass, the indicator fish species. Simulations indicate that if mercury loading were to decrease by 98.9 percent from 189

  2. Floodplain methylmercury biomagnification factor higher than that of the contiguous river (South River, Virginia USA)

    Energy Technology Data Exchange (ETDEWEB)

    Newman, Michael C., E-mail: newman@vims.edu [College of William and Mary - VIMS, P.O. Box 1346, Rt. 1208 Greate Rd., Gloucester Point, VA 23062 (United States); Xu Xiaoyu, E-mail: xiaoyu@vims.edu [College of William and Mary - VIMS, P.O. Box 1346, Rt. 1208 Greate Rd., Gloucester Point, VA 23062 (United States); Condon, Anne, E-mail: anne_condon@fws.gov [U.S. Fish and Wildlife, 6669 Short Lane, Gloucester, VA 23061 (United States); Liang Lian, E-mail: liang@cebam.net [Cebam Analytical, Inc., 18804 North Creek Parkway, Suite 110, Bothell, WA 98011 (United States)

    2011-10-15

    Mercury biomagnification on the South River floodplain (Virginia, USA) was modeled at two locations along a river reach previously modeled for methylmercury movement through the aquatic trophic web. This provided an opportunity to compare biomagnification in adjoining trophic webs. Like the aquatic modeling results, methylmercury-based models provided better prediction than those for total mercury. Total mercury Food Web Magnification Factors (FWMF, fold per trophic level) for the two locations were 4.9 and 9.5. Methylmercury FWMF for the floodplain locations were higher (9.3 and 25.1) than that of the adjacent river (4.6). Previous speculation was not resolved regarding whether the high mercury concentrations observed in floodplain birds was materially influenced by river prey consumption by riparian spiders and subsequent spider movement into the trophic web of the adjacent floodplains. Results were consistent with a gradual methylmercury concentration increase from contaminated floodplain soil, to arthropod prey, and finally, to avian predators. - Highlights: > First comparison of methylmercury biomagnification in adjacent river/land food webs. > Methylmercury increased more rapidly in the terrestrial, than the aquatic, food web. > Methylmercury increased gradually from soil, to prey, and, to avian predators. - Higher methylmercury biomagnification on South River floodplain than the associated river likely explain high mercury in floodplain birds.

  3. Modeling mercury biomagnification (South River, Virginia, USA) to inform river management decision making.

    Science.gov (United States)

    Tom, Kyle R; Newman, Michael C; Schmerfeld, John

    2010-04-01

    Mercury trophic transfer in the South River (VA, USA) was modeled to guide river remediation decision making. Sixteen different biota types were collected at six sites within 23 river miles. Mercury biomagnification was modeled using a general biomagnification model based on delta(15)N and distance from the historic mercury release. Methylmercury trophic transfer was clearer than that for total Hg and, therefore, was used to build the predictive model (r(2) (prediction) = 0.76). The methylmercury biomagnification factors were similar among sites, but model intercept did increase with distance down river. Minimum Akaike's Information Criterion Estimation (MAICE) justified the incorporation of distance in the model. A model with a very similar biomagnification factor to the South River (95% confidence intervals [CI] = 0.38-0.52) was produced for a second contaminated Virginia river, the North Fork Holston River (95% CI = 0.41-0.55). Percent of total Hg that was methylmercury increased monotonically with trophic position. Trophic models based on delta(15)N were adequate for predicting changes in mercury concentrations in edible fish under different remediation scenarios.

  4. Transforming River Basin Management In South Africa: Lessons from the Lower Komati River

    NARCIS (Netherlands)

    Waalewijn, P.; Wester, P.; Straaten, van K.

    2005-01-01

    This paper analyzes the transformation of river basin management in South Africa by focusing on the political processes involved in the creation of new water management bodies and irrigation infrastructure in the Lower Komati sub-basin. Institutional reform is described and analyzed in terms of the

  5. How to appreciate the Gardens South of the Yangtze River

    Institute of Scientific and Technical Information of China (English)

    李竹君

    2015-01-01

    The primary goal of classical Chinese garden is to provide buildings, green spaces or relaxing spaces, but it is later endowed with more functions as a carrier for showing human beings’dependence on and respect for the nature, as well as var-ious emotions of them. This article briefly discussed how to appreciate the gardens south of the Yangtze River from aspects of construction elements, artistic conception and techniques.

  6. Active overbank deposition during the last century, South River, Virginia

    Science.gov (United States)

    Pizzuto, Jim; Skalak, Katherine; Pearson, Adam; Benthem, Adam

    2016-03-01

    We quantify rates of overbank deposition over decadal to centennial timescales along the South River in Virginia using four independent methods. Detailed mercury profiles sampled adjacent to the stream channel preserve the peak historic mercury concentration on suspended sediment dating from 1955 to 1961 and suggest sedimentation rates of 8 to 50 cm/100 years. Sediment accumulation over the roots of trees suggest rates of 0 to 100 cm/100 years, with significantly higher values on levees and lower values on floodplains farther from the channel. Profiles of 137Cs and 210Pb from two eroding streambanks are fit with an advection-diffusion model calibrated at an upland reference site; these methods suggest sedimentation rates of 44 to 73 cm/100 years. Mercury inventories from 107 floodplain cores, combined with a previously published reconstruction of the history of mercury concentration on suspended sediment, provide spatially comprehensive estimates of floodplain sedimentation: median sedimentation rates are 3.8 cm/100 years for the South River. Hydrologic Engineering Center-River Analysis System (HEC-RAS) modeling demonstrates that the floodplain of the South River remains hydraulically connected to the channel: 56% of the 100-year floodplain is inundated every two years, and 83% of the floodplain is inundated every five years. These results, combined with previously published data, provide the basis for a regional synthesis of floodplain deposition rates since European settlement. Floodplain sedimentation rates were high following European settlement, with published estimates ranging from 50 to 200 cm/100 years. Sedimentation rates decreased by 1 to 2 orders of magnitude during the twentieth and twenty-first centuries; but despite these lower sedimentation rates, floodplains continue to store a significant fraction of total suspended sediment load. Many floodplains of the mid-Atlantic region are active landforms fully connected to the rivers that flow within them

  7. Sustainable development indicators: Case study for South Morava river basin

    Directory of Open Access Journals (Sweden)

    Veljković Nebojša D.

    2013-01-01

    Full Text Available The subject of research is elaboration and evaluation of indicators of sustainable development in the field of river basin management. Aggregate indicator entitled Ecoregion Sustainable Development Index is identified by calculation of average value by the procedure of leveling of proportion changes of three key indicators (demographic emission index, water quality index, industrial production index. Developed aggregate indicator of sustainable development is calculated and analyzed for South Morava river basin in Serbia, for the period from 1980 to 2010. The beneficiaries of these indicators are the experts from the field of environmental protection and water management who should use it for elaboration of reports directed towards the creators of economic development policy and river basin management planning. Elaborated according to the given methodology, the indicator Ecoregion Sustainable Development Index is available for the decision makers on the national level, internationally comparative and it provides the conditions for further elaboration and application.

  8. 33 CFR 165.709 - Security Zone; Charleston Harbor, Cooper River, South Carolina.

    Science.gov (United States)

    2010-07-01

    ..., Cooper River, South Carolina. 165.709 Section 165.709 Navigation and Navigable Waters COAST GUARD... § 165.709 Security Zone; Charleston Harbor, Cooper River, South Carolina. (a) Regulated area. The Coast Guard is establishing a fixed security zone on all waters of the Cooper River, bank-to-bank and...

  9. Floodplain methylmercury biomagnification factor higher than that of the contiguous river (South River, Virginia USA).

    Science.gov (United States)

    Newman, Michael C; Xu, Xiaoyu; Condon, Anne; Liang, Lian

    2011-10-01

    Mercury biomagnification on the South River floodplain (Virginia, USA) was modeled at two locations along a river reach previously modeled for methylmercury movement through the aquatic trophic web. This provided an opportunity to compare biomagnification in adjoining trophic webs. Like the aquatic modeling results, methylmercury-based models provided better prediction than those for total mercury. Total mercury Food Web Magnification Factors (FWMF, fold per trophic level) for the two locations were 4.9 and 9.5. Methylmercury FWMF for the floodplain locations were higher (9.3 and 25.1) than that of the adjacent river (4.6). Previous speculation was not resolved regarding whether the high mercury concentrations observed in floodplain birds was materially influenced by river prey consumption by riparian spiders and subsequent spider movement into the trophic web of the adjacent floodplains. Results were consistent with a gradual methylmercury concentration increase from contaminated floodplain soil, to arthropod prey, and finally, to avian predators.

  10. 2011 UMRS Color Infrared Aerial Photo Mosaic - Mississippi River, Open River South South

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Upper Mississippi River Restoration-Environmental Management Program (UMRR-EMP) partnered with the U.S. Fish and Wildlife Service (USFWS) Region 3 to collect...

  11. Environmental Survey preliminary report, Savannah River Plant, Aiken, South Carolina

    Energy Technology Data Exchange (ETDEWEB)

    1987-08-01

    This report contains the preliminary findings based on the first phase of an Environmental Survey at the Department of Energy (DOE) Savannah River Plant (SRP), located at Aiken, South Carolina. The Survey is being conducted by DOE's Office of Environment, Safety and Health. The following topics are discussed: general site information; air, soil, surface water and ground water; hydrogeology; waste management; toxic and chemical materials; release of tritium oxides; radioactivity in milk; contamination of ground water and wildlife; pesticide use; and release of radionuclides into seepage basins. 149 refs., 44 figs., 53 tabs.

  12. PREVALENCE OF HYPERTENSION AMONG FIREFIGHTERS IN RIVERS STATE, SOUTH-SOUTH, NIGERIA.

    Science.gov (United States)

    Douglas, Kingsley Enyinnah; Oraekesi, Chidi Kelvin

    2015-01-01

    High blood pressure is a major cause of morbidity and mortality in Sub-Saharan Africa and firemen (firefighters) may be especially predisposed to it or even exacerbate pre-existing hypertension as a result of the nature of their job. This study was to determine the prevalence of hypertension among firemen in Rivers state, South-South Nigeria. Following ethical clearance, 125 consenting firemen of the Rivers State Fire Service were recruited in this descriptive cross sectional study. They responded to a pre-tested, structured, closed-ended self-administered questionnaire which probed their socio-demographics, knowledge, attitude and practice towards hypertension. Also, their blood pressures heights and weights were measured from where Body Mass Index (BMI) was calculated. A WalkThrough Survey for immediate work place situation and safety was carried out. Data collected were later analyzed using descriptive and analytical statistical tools. There was a 9.6% prevalence of hypertension among this group of workers in Rivers State. The workforce was essentially young with a modal age group of between 31-36 years. The attendant associated risk factors included altered sleep patterns, over weight and smoking which were all statistically significant P hypertension was high (96%), the behaviour of respondents towards prevention and control of hypertension was poor. There is hypertension among firemen of the Rivers State Fire Service occasioned by modifiable risk factors despite adequate knowledge. It is recommended that intensive health education, early detection and treatment be instituted among this group of workers.

  13. Long-term solar activity influences on South American rivers

    CERN Document Server

    Mauas, Pablo; Flamenco, Eduardo

    2010-01-01

    River streamflows are excellent climatic indicators since they integrate precipitation over large areas. Here we follow up on our previous study of the influence of solar activity on the flow of the Parana River, in South America. We find that the unusual minimum of solar activity in recent years have a correlation on very low levels in the Parana's flow, and we report historical evidence of low water levels during the Little Ice Age. We also study data for the streamflow of three other rivers (Colorado, San Juan and Atuel), and snow levels in the Andes. We obtained that, after eliminating the secular trends and smoothing out the solar cycle, there is a strong positive correlation between the residuals of both the Sunspot Number and the streamflows, as we obtained for the Parana. Both results put together imply that higher solar activity corresponds to larger precipitation, both in summer and in wintertime, not only in the large basin of the Parana, but also in the Andean region north of the limit with Patago...

  14. Solid and aqueous mercury in remote river sediments (Litany River, French Guyana, South America)

    Science.gov (United States)

    Charlet, L.; Roman-Ross, G.; Spadini, L.; Rumbach, G.

    2003-05-01

    Mercury content in river sediments was investigated, in the Haut Maroni river basin (French Guyana, South America), around Antecume-Pata, a village where Wayanas Amerindians are contaminated with mercury. Solid sediment particulate total mercury content indicate a 100 to 150 ng/g Hg geochemical background level. Sediments act as an environmental archive: gold mining contaminated sediments have up to 400 ng/g total mercury. Pore waters from contaminated sediments are enriched in Fe(II) and Hg(II) by a factor 40 compared to uncontaminated sediment pore waters, due to more acute anoxie conditions. They act therefore as a major source of dissolved mercury in remote tropical aquatic ecosystems. Keywords: Mercury, sediment, DGT and DET techniques, pore water, gold mining.

  15. Human foot bones from Klasies River main site, South Africa.

    Science.gov (United States)

    Rightmire, G Philip; Deacon, H J; Schwartz, Jeffrey H; Tattersall, Ian

    2006-01-01

    The caves at Klasies River contain abundant archaeological evidence relating to human evolution in the late Pleistocene of southern Africa. Along with Middle Stone Age artifacts, animal bones, and other food waste, there are hominin cranial fragments, mandibles with teeth, and a few postcranial remains. Three foot bones can now be added to this inventory. An adult first metatarsal is similar in size and discrete anatomical features to those from Holocene burials in the Cape Province. A complete and well-preserved second metatarsal is especially long and heavy at midshaft in comparison to all Holocene and more recent South African homologues. A large fifth metatarsal is highly distinctive in its morphology. In overall size, these pedal elements resemble specimens from late Pleistocene sites in western Asia, but there are some differences in proportions. The fossils support earlier suggestions concerning a relatively high level of sexual dimorphism in the African Middle Stone Age population. Squatting facets on the two lateral metatarsals appear to indicate a high frequency of kneeling among members of this group. The new postcranial material also underlines the fact that the morphology of particular skeletal elements of some of the 100,000-year-old Klasies River individuals falls outside the range of modern variation.

  16. 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

  17. Comparing the Planform Morphologies of a Freely Meandering Channel and the Bedrock- Controlled South River, VA.

    Science.gov (United States)

    Narinesingh, P.; Pizzuto, J.

    2008-12-01

    The planforms of the lithologically controlled South River, VA, and the freely meandering Teklanika River, AK were investigated using two statistical methods as well as fractal and spectral analyses. The lithologic controls along the South River include riverbanks consisting of pre-Holocene terraces and alluvial fans, and highly resistant bedrock that frequently crops out both in the bed and along the banks. A statistical analysis of bends composed of single arcs shows that the average radius of curvature is six times greater and the average bend length is 25 percent smaller for the South River relative to the meandering river, indicating that lithologically controlled bends are less curved and shorter than freely-formed meander bends. Fractal analysis reveals that the meandering river displays a smaller range in length scales than the South River, which exhibits a wider range in length scales that reflect a wider distribution of bend sizes. The method of Lancaster and Bras, (2002), which identifies bends of different complexity, indicates that the meandering river displays bends composed of single arcs, complex arcs and multiple complex arcs. Unlike the freely meandering Teklanika River, the lithologically controlled South River does not display bends composed of multiple complex arcs, though bends composed of single and complex arcs are common. Spectral analysis reveals that the meandering river's pattern is composed of a relatively narrow range of dominant wavelengths with the most prominent wavelength being the longest, while the lithologically controlled river displays dominant wavelengths over a relatively wide range and the most prominent wavelength is not the longest. This analysis demonstrates that lithological controls increase the range of bend lengths, increase radii of curvature, simplify bend shapes, and increase the distribution of wavelengths of sinuous rivers.

  18. Altered River Morphology in South Africa Related to the Permian-Triassic Extinction

    National Research Council Canada - National Science Library

    Peter D. Ward; David R. Montgomery; Roger Smith

    2000-01-01

    The Permian-Triassic transition in the Karoo Basin of South Africa was characterized by a rapid and apparently basin-wide change from meandering to braided river systems, as evidenced by preserved sedimentary facies...

  19. Comparative Analysis Of River Conservation In The United States And South Africa

    Science.gov (United States)

    Both the United States and South Africa are recognized for their strong and innovative approaches to the conservation of river ecosystems. These national programs possess similar driving legislation and ecoregional classification schemes supported by comprehensive monitoring prog...

  20. Boundaries of Consent: Stakeholder Representation in River Basin Management in Mexico and South Africa

    NARCIS (Netherlands)

    Wester, P.; Merrey, D.J.; Lange, M.

    2003-01-01

    Increasing the capacity of water users to influence decision-making is crucial in river basin management reforms. This article assesses emerging forums for river basin management in Mexico and South Africa and concludes that the pace of democratization of water management in both is slow. Mexico is

  1. Focus on CSIR research in pollution waste: The South African river health programme

    CSIR Research Space (South Africa)

    Hill, Liesl

    2007-08-01

    Full Text Available the design of the River Health Programme (RHP) to monitor the health of rivers in South Africa. The RHP forms part of a bigger initiative, the National Aquatic Ecosystem Health Monitoring Programme which will eventually cover all surface water resources...

  2. UMRS LTRMP 2010/11 LCU Mapping -- Open River South

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Aerial photographs for Pools 1-13 Upper Mississippi River System and Pools, Alton-Marseilles, Illinois River were collected in color infrared (CIR) in August of 2010...

  3. Magnetic minerals in three Asian rivers draining into the South China Sea: Pearl, Red, and Mekong Rivers

    Science.gov (United States)

    Kissel, Catherine; Liu, Zhifei; Li, Jinhua; Wandres, Camille

    2016-05-01

    The use of the marine sedimentary magnetic properties, as tracers for changes in precipitation rate and in oceanic water masses transport and exchanges, implies to identify and to characterize the different sources of the detrital fraction. This is of particular importance in closed and/or marginal seas such as the South China Sea. We report on the magnetic properties of sedimentary samples collected in three main Asian rivers draining into the South China Sea: the Pearl, Red, and Mekong Rivers. The geological formations as well as the present climatic conditions are different from one catchment to another. The entire set of performed magnetic analyses (low-field magnetic susceptibility, ARM acquisition and decay, IRM acquisition and decay, back-field acquisition, thermal demagnetization of three-axes IRM, hysteresis parameters, FORC diagrams, and low-temperature magnetic measurements) allow us to identify the magnetic mineralogy and the grain-size distribution when magnetite is dominant. Some degree of variability is observed in each basin, illustrating different parent rocks and degree of weathering. On average it appears that the Pearl River is rich in magnetite along the main stream while the Mekong River is rich in hematite. The Red River is a mixture of the two. Compared to clay mineral assemblages and major element contents previously determined on the same samples, these new findings indicate that the magnetic fraction brings complementary information of great interest for environmental reconstructions based on marine sediments from the South China Sea.

  4. Focus on CSIR research in pollution waste: South African national spatial biodiversity assessment 2004 (Technical report volume 2: river component)

    CSIR Research Space (South Africa)

    Roux, D

    2007-08-01

    Full Text Available This report forms the river component of the National Spatial Biodiversity Assessment, which focuses on spatial conservation assessments for South Africa’s terrestrial, river, marine, estuarine and wetland ecosystems. The results presented form...

  5. Hydrogeochemical and isotopic investigations of the Han River basin, South Korea

    Science.gov (United States)

    Ryu, Jong-Sik; Lee, Kwang-Sik; Chang, Ho-Wan

    2007-10-01

    SummaryThe Han River, the largest river in South Korea draining approximately 26,000 km 2, comprises two major tributaries: the North and the South Han Rivers. Seasonal and spatial variations in the major ion chemistry and isotope compositions of the Han River were monitored for one year at 14-23 locations, covering about 80% of the entire drainage basin. Compared to the South Han River (SHR), the North Han River (NHR) was much lower in total dissolved solids (TDS), Sr, and major ion concentrations, but higher in Si concentration, δ 34S SO 4 values, and 87Sr/ 86Sr ratios. These observations suggest strong influence of prevailing rock types in the drainage basins on the chemical and isotopic compositions of the river waters. These are silicate rocks in the NHR basin and carbonate rocks in the SHR basin. The headwaters of the NHR basin, where several flood control dams have been constructed, show enrichment in deuterium and oxygen-18, indicating evaporative loss. The δ 34S SO 4 data suggest dissolved sulfates in the NHR and SHR are mostly derived from atmospheric deposition, and variable mixtures of atmospheric deposition and sulfide oxidation, respectively. The 87Sr/ 86Sr ratios are much higher in the NHR (0.71793-0.72722) than in the SHR (0.71495-0.71785) with one exception, indicating weathering of Precambrian and Mesozoic granitic rocks and marine carbonates, respectively.

  6. Higher and more variable methylmercury biomagnification factors for floodplain than the contiguous river (South River, Virginia USA).

    Science.gov (United States)

    Wang, Jincheng; Newman, Michael C; Xu, Xiaoyu; Liang, Lian

    2013-06-01

    Extending previous trophic transfer studies of the mercury-contaminated South River watershed, predictive models were built for mercury biomagnification in floodplain food webs at two more locations (North Park and Grand Cavern). Four of five models built to date based on methylmercury and δ(15)N met the a priori requirement for useful prediction (prediction r(2)≈0.80). An additional factor included in models was organism thermoregulatory strategy (poikilothermy or homeothermy). The methylmercury food web biomagnification factors (FWMFs, fold increase per trophic level) for the North Park and Grand Cavern locations were 17.4 (95% CI of 9.5-31.6) and 6.2 (95% CI of 3.5-11.0) respectively. FWMF calculated in 2009 were 9.3 (95% CI of 5.4-16.2) for the Augusta Forestry Center and 25.1 (95% CI of 12.6-50.1) for Grottoes Town Park. The overall South River floodplain FWMF generated by meta-analysis of the four locations was 12.4 (95% CI of 6.8-22.3). These results supported previous findings that the South River floodplain food webs had higher biomagnification factors than the contiguous aquatic food web (4.6, 95% CI of 3.6-5.7). Floodplain FWMFs were also more variable than those of the river.

  7. Flood-inundation map library for the Licking River and South Fork Licking River near Falmouth, Kentucky

    Science.gov (United States)

    Lant, Jeremiah G.

    2016-09-19

    Digital flood inundation maps for a 17-mile reach of Licking River and 4-mile reach of South Fork Licking River near Falmouth, Kentucky, were created by the U.S. Geological Survey (USGS) in cooperation with Pendleton County and the U.S. Army Corps of Engineers–Louisville District. The inundation maps, which can be accessed through the USGS Flood Inundation Mapping Science Web site at http://wim.usgs.gov/FIMI/FloodInundationMapper.html, depict estimates of the areal extent and depth of flooding corresponding to selected water levels (stages) at the USGS streamgage on the Licking River at Catawba, Ky., (station 03253500) and the USGS streamgage on the South Fork Licking River at Hayes, Ky., (station 03253000). Current conditions (2015) for the USGS streamgages may be obtained online at the USGS National Water Information System site (http://waterdata.usgs.gov/nwis). In addition, the streamgage information has been provided to the National Weather Service (NWS) for incorporation into their Advanced Hydrologic Prediction Service (AHPS) flood warning system (http:/water.weather.gov/ahps/). The flood hydrograph forecasts provided by the NWS are usually collocated with USGS streamgages. The forecasted peak-stage information, also available on the NWS Web site, may be used in conjunction with the maps developed in this study to show predicted areas of flood inundation.In this study, flood profiles were computed for the Licking River reach and South Fork Licking River reach by using a one-dimensional step-backwater model. The hydraulic model was calibrated by using the most current (2015) stage-discharge relations for the Licking River at Catawba, Ky., and the South Fork Licking River at Hayes, Ky., USGS streamgages. The calibrated model was then used to calculate 60 water-surface profiles for a sequence of flood stages, at 2-foot intervals, referenced to the streamgage datum and ranging from an elevation near bankfull to the elevation associated with a major flood that

  8. Use of Landscape-level River Signatures in Conservation Planning: a South African Case Study

    Directory of Open Access Journals (Sweden)

    Jim Cambray

    2002-12-01

    Full Text Available A strategy for assigning priorities in biodiversity conservation was developed for the rivers of the proposed Greater Addo Elephant National Park (GAENP in South Africa. Due to the limited availability of biological information on the freshwater ecosystems of this area, a desktop approach, supplemented by aerial and land surveys, was used to devise a new river classification typology. This typology incorporated landscape attributes as surrogates for biodiversity patterns, resulting in defined physical "signatures" for each river type. Riverine biodiversity is considered to be conserved by including rivers of each type as defined by the respective signatures. Where options existed, and two or more rivers shared the same signature, a simple procedure was used to assign priorities to "similar" rivers for conservation. This procedure considered the extent of transformation, degree of inclusion within the park, irreplaceability or uniqueness, and geomorphological diversity of each river. The outcome of the study was that 18 of the 31 rivers within the GAENP must be conserved to achieve representation of all of the biodiversity patterns identified. It is concluded that, given further development and testing, the river signature concept holds promise for elevating the river focus in general conservation planning exercises.

  9. Contamination profiles of perfluoroalkyl substances in five typical rivers of the Pearl River Delta region, South China.

    Science.gov (United States)

    Pan, Chang-Gui; Ying, Guang-Guo; Liu, You-Sheng; Zhang, Qian-Qian; Chen, Zhi-Feng; Peng, Feng-Jiao; Huang, Guo-Yong

    2014-11-01

    A survey on contamination profiles of eighteen perfluoroalkyl substances (PFASs) was performed via high performance liquid chromatography-tandem mass spectrometry for surface water and sediments from five typical rivers of the Pearl River Delta region, South China in summer and winter in 2012. The total concentrations of the PFASs in the water phase of the five rivers ranged from 0.14 to 346.72 ng L(-1). The PFAS concentrations in the water phase were correlated positively to some selected water quality parameters such as chemical oxygen demand (COD) (0.7913) and conductivity (0.5642). The monitoring results for the water samples showed significant seasonal variations, while those for the sediment samples showed no obvious seasonal variations. Among the selected 18 PFASs, perfluorooctane sulfonic acid (PFOS) was the dominant PFAS compound both in water and sediment for two seasons with its maximum concentration of 320.5 ng L(-1) in water and 11.4 ng g(-1) dry weight (dw) in sediment, followed by perfluorooctanoic acid (PFOA) with its maximum concentration of 26.48 ng L(-1) in water and 0.99 ng g(-1) dw in sediment. PFOS and PFOA were found at relatively higher concentrations in the Shima River and Danshui River than in the other three rivers (Xizhijiang River, Dongjiang River and Shahe River). The principal component analysis for the PFASs concentrations in water and sediment separated the sampling sites into two groups: rural and agricultural area, and urban and industrial area, suggesting the PFASs in the riverine environment were mainly originated from industrial and urban activities in the region.

  10. Development of an empirical nonlinear model for mercury bioaccumulation in the South and South Fork Shenandoah rivers of Virginia.

    Science.gov (United States)

    Brent, Robert N; Kain, Donald G

    2011-11-01

    Mercury is a globally distributed pollutant that biomagnifies in aquatic food webs. In the United States, 3781 water bodies fail to meet criteria for safe fish consumption due to mercury bioaccumulation. In the risk assessment and management of these impairments (through the total maximum daily load program), an important step is evaluating the relationship between aqueous mercury and mercury in fish tissue. Often, this relationship is simplified to a bioaccumulation factor (BAF): the ratio of fish tissue mercury to aqueous mercury. This article evaluates the relationship between aqueous mercury and fish tissue mercury across a contamination gradient in the South and South Fork Shenandoah rivers of Virginia. The relationship was found to be nonlinear, with BAFs decreasing as the level of contamination increased. This means that protective water column mercury concentration targets established from site-specific BAFs will be overestimated in contaminated areas and will not be sufficiently protective. To avoid this over-prediction in the South and South Fork Shenandoah rivers, an empirical nonlinear Michaelis-Menten model was used to establish a protective water-quality target. Among other models and variables, the Michaelis-Menten model, relating total mercury in the water column to methylmercury in fish tissue, achieved the best empirical fit (r(2) = 0.9562). The resulting water-quality targets using this model were 3.8 and 3.2 ng/l for the South and South Fork Shenandoah rivers, respectively. These values are 2.1-2.5 times lower than the water-quality target developed using a site-specific BAF. These findings demonstrate the need to consider nonlinear BAF relationships in mercury-contaminated areas.

  11. 77 FR 66865 - Record of Decision for the Oil and Gas Management Plan, Big South Fork National River and...

    Science.gov (United States)

    2012-11-07

    ... National Park Service Record of Decision for the Oil and Gas Management Plan, Big South Fork National River....C. 4332(2)(C), the National Park Service (NPS) announces the availability of the Record of Decision (ROD) for the Oil and Gas Management Plan (Plan) for Big South Fork National River and Recreation Area...

  12. River-flow predictions for the South African mid-summer using a coupled general circulation model

    CSIR Research Space (South Africa)

    Olivier, C

    2013-09-01

    Full Text Available There are limited sources of streamflow data available in South Africa. These include simulated streamflow for catchments across South Africa and measured river-flow at specific rivers around the country. Given that a number of studies has been done...

  13. Alternative Water Allocation in Kyrgyzstan: Lessons from the Lower Colorado River Basin and New South Wales

    Directory of Open Access Journals (Sweden)

    Nazir Mirzaev

    2010-08-01

    Full Text Available Focus group discussions and a modeling approach were applied to determine policy and regulatory refinements for current water allocation practices in Kyrgyzstan. Lessons from the Lower Colorado River basin, Texas and New South Wales, Australia were taken into consideration. The paper analyzes the impact of adopting some of these interventions within the socio-environmental context that currently prevails in Kyrgyzstan. The optimization model for water distribution at the river-basin scale was developed using GAMS 2.25 software. Application of the model to the Akbura River basin indicated efficiencies in the proposed institutional rules especially in low water years.

  14. Modeling water quality, temperature, and flow in Link River, south-central Oregon

    Science.gov (United States)

    Sullivan, Annett B.; Rounds, Stewart A.

    2016-09-09

    The 2.1-km (1.3-mi) Link River connects Upper Klamath Lake to the Klamath River in south-central Oregon. A CE-QUAL-W2 flow and water-quality model of Link River was developed to provide a connection between an existing model of the upper Klamath River and any existing or future models of Upper Klamath Lake. Water-quality sampling at six locations in Link River was done during 2013–15 to support model development and to provide a better understanding of instream biogeochemical processes. The short reach and high velocities in Link River resulted in fast travel times and limited water-quality transformations, except for dissolved oxygen. Reaeration through the reach, especially at the falls in Link River, was particularly important in moderating dissolved oxygen concentrations that at times entered the reach at Link River Dam with marked supersaturation or subsaturation. This reaeration resulted in concentrations closer to saturation downstream at the mouth of Link River.

  15. Flora of the Kap River Reserve, Eastern Cape, South Africa

    Directory of Open Access Journals (Sweden)

    E. C. Cloete

    1999-12-01

    Full Text Available A detailed analysis ot the flora of the newly proclaimed Kap River Reserve (600 ha is given. The reserve is adjacent to the Fish River and some 5 km from the Fish River Mouth It consists of a coastal plateau up to 100 m a.s.I. which is steeply dissected by the two rivers that partially form the boundary of the reserve. The flora of the reserve was sampled over a period o f three years and plants were collected in all the vegetation types of grassland, thicket and forest. 488 species were collected with a species to family ratio of 4:4. The majority of the taxa recorded represent the major phytochoria of the region. Nineteen species are endemic to the Eastern Cape, two are classed as vulnerable, five are rare, six are protected and a further seventeen are of uncertain status. The flora of the Kap River has closest affinities to that of the Alexandria Forest.

  16. 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

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

    Science.gov (United States)

    Mathison, C.; Wiltshire, A. J.; Falloon, P.; Challinor, A. J.

    2015-06-01

    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 simulation provides a

  18. 33 CFR 117.1093 - Milwaukee, Menomonee, and Kinnickinnic Rivers and South Menomonee and Burnham Canals.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Milwaukee, Menomonee, and Kinnickinnic Rivers and South Menomonee and Burnham Canals. 117.1093 Section 117.1093 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Wisconsin § 117.1093...

  19. Fish community of a small, temperate, urban river in South Africa

    African Journals Online (AJOL)

    2015-10-05

    Oct 5, 2015 ... (23 km long), urban river in the Eastern Cape of South Africa that rises and ... Aonyx capensis, their use limits the maximum size of fish sampled in the .... Spearman Rank Correlation test was used to test for relation- ships between ... migrant species, the dominant, uniformly distributed alien spe- cies were ...

  20. Tumor prevalence in brown bullheads (Ameiurus nebulosus) from the South River, Anne Arundel County, Maryland

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The South River is a tributary of the Chesapeake Bay flowing near Annapolis, Maryland. In March 2005, brown bullheads were collected in a fyke net set about 1.25 km...

  1. The impact of anthropogenic discharges on Arkansas river shiner (Notropis girardi) habitat within the South Canadian River watershed in the Texas Panhandle, 2001-2002

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — In 2001, the USFWS Arlington, Texas Field Office initiated a one-year study on the mainstem of the South Canadian River in the Texas Panhandle to determine the...

  2. River flow and fish abundance in a South African estuary

    CSIR Research Space (South Africa)

    Whitfield, AK

    2003-06-01

    Full Text Available The ichthyofauna of the Thukela Estuary, a small (55 ha), shallow (<1_5 m) system on the KwaZulu-Natal coast (mean annual river runoff of 3865_106m3, from a large catchment of29 000km2, is seasonal: peak inputs occurring between November and March...

  3. Ecological Research on South African rivers - a preliminary synthesis

    CSIR Research Space (South Africa)

    O'Keeffe, JH

    1986-01-01

    Full Text Available resource, were deteriorating in the face of overexploitation, led to a coordinated research programme by the NIWR in the 1950's and 1960s, which included in-depth studies on representative rivers such as the Great Berg, the Tugela, the Jukskei...

  4. Occurrence, Distribution and Ecological Risks of Fluoroquinolone Antibiotics in the Dongjiang River and the Beijiang River, Pearl River Delta, South China.

    Science.gov (United States)

    Zhang, Ruiling; Zhang, Ruijie; Zou, Shichun; Yang, Ying; Li, Jun; Wang, Yinghui; Yu, Kefu; Zhang, Gan

    2017-07-01

    The occurrence and distribution of five selected fluoroquinolones (FQs) were studied in the Dongjiang River and the Beijiang River, South China. Ciprofloxacin, norfloxacin and enoxacin, used as human and veterinary medicines, were detected with detection frequencies of 75%-100% and average concentrations of 9.5-18.8 ng L(-1) in the two rivers. Meanwhile, enrofloxacin, which is only used as veterinary medicine, was detected at lower levels (2.9-4.0 ng L(-1)) than those of ciprofloxacin, norfloxacin and enoxacin. The spatial distribution of the five FQs exhibited a close relationship with the intensity of local human activity. Certain antibiotics were detected in industrial wastewater and domestic sewage at considerably higher concentrations than those measured in the river water, indicating important sources of antibiotic contamination. Finally, an ecological risk assessment based on the calculated risk quotient showed that ciprofloxacin could pose high risk to Microcystis aeruginosa (M. aeruginosa). The two rivers are important sources of drinking water and should arouse the attention of relevant departments. Effective measures must be taken to strengthen the protection of the two rivers.

  5. Discovery of South American suckermouth armored catfishes (Loricariidae, Pterygoplichthys spp.) in the Santa Fe River drainage, Suwannee River basin, USA

    Science.gov (United States)

    Nico, Leo G.; Butt, Peter L.; Johnston, Gerald R.; Jelks, Howard L.; Kail, Matthew; Walsh, Stephen J.

    2012-01-01

    We report on the occurrence of South American suckermouth armored catfishes (Loricariidae) in the Suwannee River basin, southeastern USA. Over the past few years (2009-2012), loricariid catfishes have been observed at various sites in the Santa Fe River drainage, a major tributary of the Suwannee in the state of Florida. Similar to other introduced populations of Pterygoplichthys, there is high likelihood of hybridization. To date, we have captured nine specimens (270-585 mm, standard length) in the Santa Fe River drainage. One specimen taken from Poe Spring best agrees with Pterygoplichthys gibbiceps (Kner, 1854) or may be a hybrid with either P. pardalis or P. disjunctivus. The other specimens were taken from several sites in the drainage and include seven that best agree with Pterygoplichthys disjunctivus (Weber, 1991); and one a possible P. disjunctivus x P. pardalis hybrid. We observed additional individuals, either these or similar appearing loricariids, in Hornsby and Poe springs and at various sites upstream and downstream of the long (> 4 km) subterranean portion of the Santa Fe River. These specimens represent the first confirmed records of Pterygoplichthys in the Suwannee River basin. The P. gibbiceps specimen represents the first documented record of an adult or near adult of this species in open waters of North America. Pterygoplichthys disjunctivus or its hybrids (perhaps hybrid swarms) are already abundant and widespread in other parts of peninsular Florida, but the Santa Fe River represents a northern extension of the catfish in the state. Pterygoplichthys are still relatively uncommon in the Santa Fe drainage and successful reproduction not yet documented. However, in May 2012 we captured five adult catfish (two mature or maturing males and three gravid females) from a single riverine swallet pool. One male was stationed at a nest burrow (no eggs present). To survive the occasional harsh Florida winters, these South American catfish apparently use

  6. High prevalence of multiple-antibiotic-resistant (MAR) Escherichia coli in river bed sediments of the Apies River, South Africa.

    Science.gov (United States)

    Abia, Akebe Luther King; Ubomba-Jaswa, Eunice; Momba, Maggy Ndombo Benteke

    2015-10-01

    This study aimed at investigating the presence of antibiotic-resistant Escherichia coli in river bed sediments of the Apies River, Gauteng, South Africa, in order to better inform health management decisions designed to protect users of the river. Overall, 180 water and sediment samples were collected at 10 sites along the Apies River from January to February 2014. E. coli was enumerated using the Colilert® 18/Quanti-Tray® 2000 (IDEXX). Isolates were purified by streaking on eosin methylene blue agar followed by the indole test. Pure E. coli isolates were tested for resistance to nine antibiotics by the Kirby-Bauer disc diffusion method. Over 98% of the isolates were resistant to at least one of the antibiotics tested. The highest resistance was observed against nitrofurantoin (sediments) and ampicillin (water). Over 80% of all resistant isolates showed multiple antibiotic resistance (resistance to ≥3 antibiotics). The abundance of E. coli in the sediments not only adds to the evidence that sediments are a reservoir for bacteria and possibly other pathogens including antibiotic-resistant bacteria but also suggests that antibiotic-resistant genes could be transferred to pathogens due to the high prevalence of multiple-antibiotic-resistant (MAR) strains of E. coli observed in the sediment. Using untreated water from the Apies River following resuspension for drinking and other household purposes could pose serious health risks for users. Our results suggest that river bed sediments could serve as reservoirs for MAR bacteria including pathogens under different climatic conditions and their analysis could provide information of public health concerns.

  7. Civil society and sanitation hydropolitics: A case study of South Africa’s Vaal River Barrage

    Science.gov (United States)

    Tempelhoff, Johann W. N.

    The Vaal River Barrage, situated on the south-eastern border of the Gauteng Province, has been part of the hydrological landscape of South Africa’s most populous and economically active region for more than eight decades. After its completion in 1923 the Barrage was compromised by the construction, upstream, of the Vaal Dam (1930-1933). Today the Vaal River Barrage is primarily a storage facility of sewage and industrial waste water. South Africa’s transition to a multi-racial democracy in 1994 saw a number of socio-economic and political transformations that affected the water infrastructure. In the field of sanitation infrastructure in particular, conditions have deteriorated to the extent that the health of people in many parts of the country is being compromised. Using the Vaal River Barrage as a case study, this article outlines the efforts by civil society to make the relevant government sectors aware of this hazardous state of affairs. particular attention is given to save our Vaal environment (SAVE), a non-governmental organisation, at the helm of an active campaign to reduce pollution in the Vaal River Barrage.

  8. 2011 UMRS Color Infrared Aerial Photo Mosaic - Mississippi River, Open River North South

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Upper Mississippi River Restoration-Environmental Management Program (UMRR-EMP) partnered with the U.S. Fish and Wildlife Service (USFWS) Region 3 to collect...

  9. A comparative study of institutional adaptive capacity : South Saskatchewan River Basin, Canada, and Elqui River Basin, Northern Chile

    Energy Technology Data Exchange (ETDEWEB)

    Sauchyn, D.; Diaz, P.; Gauthier, D. [Regina Univ., SK (Canada)

    2005-07-01

    This presentation discussed the strategies and materials developed for a five-year study of the capacity of institutions in two dryland regions (the South Saskatchewan River Basin in western Canada and the Elqui River Basin of north-central Chile) to adapt to the impacts of climate change. The purpose of the project was to obtain a systematic and comprehensive understanding of the capacities of regional institutions to formulate and implement strategies of adaptation to climate change risks and the forecasted impacts of climate change on the supply and management of water resources in dryland environments. Both regions are at different stages of social and environmental vulnerability and yet have a dry climate adjacent to a major mountain system and landscapes at risk of desertification, as well as an agricultural economy dependent on irrigation water derived from mountain snow and glaciers. tabs., figs.

  10. Selected hydrologic data, Yampa River basin and parts of the White River basin, northwestern Colorado and south-central Wyoming

    Science.gov (United States)

    Giles, T.F.; Brogden, Robert E.

    1978-01-01

    Selected hydrologic data are presented from four energy-related projects conducted by the U.S. Geological Survey in the Yampa River basin and parts of the White River basin in northwestern Colorado and south-central Wyoming. Water-quality data during 1974 and 1975 and parts of 1976 for 129 ground-water sites and 119 surface-water sites are tabulated. For most samples, major cations, anions, and trace metals were analyzed. For the same time period, field measurements of specific conductance, temperature, and pH were made on 252 springs and wells. These samplings sites, as well as the locations of 20 climatological stations, 18 snow-course sites, and 43 surface-water gaging stations, are shown on maps. Geologic units that contain coal deposits or supply much of the water used for stock and domestic purposes in the area also are shown on a map. (Woodard-USGS)

  11. A Bayesian Approach to Integrated Ecological and Human Health Risk Assessment for the South River, Virginia Mercury-Contaminated Site.

    Science.gov (United States)

    Harris, Meagan J; Stinson, Jonah; Landis, Wayne G

    2017-07-01

    We conducted a regional-scale integrated ecological and human health risk assessment by applying the relative risk model with Bayesian networks (BN-RRM) to a case study of the South River, Virginia mercury-contaminated site. Risk to four ecological services of the South River (human health, water quality, recreation, and the recreational fishery) was evaluated using a multiple stressor-multiple endpoint approach. These four ecological services were selected as endpoints based on stakeholder feedback and prioritized management goals for the river. The BN-RRM approach allowed for the calculation of relative risk to 14 biotic, human health, recreation, and water quality endpoints from chemical and ecological stressors in five risk regions of the South River. Results indicated that water quality and the recreational fishery were the ecological services at highest risk in the South River. Human health risk for users of the South River was low relative to the risk to other endpoints. Risk to recreation in the South River was moderate with little spatial variability among the five risk regions. Sensitivity and uncertainty analysis identified stressors and other parameters that influence risk for each endpoint in each risk region. This research demonstrates a probabilistic approach to integrated ecological and human health risk assessment that considers the effects of chemical and ecological stressors across the landscape. © 2017 Society for Risk Analysis.

  12. No Red River capture since the late Oligocene: Geochemical evidence from the Northwestern South China Sea

    Science.gov (United States)

    Zhao, Meng; Shao, Lei; Liang, Jianshe; Li, Qianyu

    2015-12-01

    Rare earth elements (REE) in the sediment samples of six industrial wells from the Yinggehai-Song Hong Basin in the Northwestern South China Sea were analyzed and compared with the detrital zircon U-Pb data from earlier studies to extrapolate sediment provenance. The results reveal that the Red River (Song Hong River), Hainan Island and Central Vietnam have been the main provenances of the Yinggehai-Song Hong Basin since the late Oligocene. The Red River has been supplying sediments with positive Eu anomalies from basic-ultrabasic metamorphic and volcanic parent rocks to most parts of the basin, while Hainan Island has delivered sediments with negative Eu anomalies from granitic and sedimentary parent rocks to the eastern slope area of the basin. The progradational downlap structures in the seismic profiles also support the finding that the sediment supply is mainly from the Red River and from Hainan Island. The metamorphic rocks, which are widespread within the Red River drainage, not only provided high volumes of sediments to the basin but also contributed to the positive Eu anomalies observed. Because their REE and U-Pb signatures are similar to those of the Red River source, the metamorphic and igneous rocks of the Song Ma Suture Zone, Kontum Massif, and Jinghong area were probably parts of a large basic provenance region before being separated by strike-slip movements along the Ailao Shan-Red River shear zone. Furthermore, our results indicate that the Red River drainage area has been relatively stable since the late Oligocene. Therefore, if a drainage capture from the Red River occurred, it is likely to have taken place before the late Oligocene.

  13. Impact on ecotourism by water pollution in the Olifants River catchment, South Africa

    CSIR Research Space (South Africa)

    Oberholster, Paul J

    2009-12-01

    Full Text Available . Olifants R. Olifants R. W ilge R. Sa alboomsp ru it R . Namibia Botswana Lesotho Swaziland Mozambique South Africa Bro nkh ors tsp ru it R . Steenkoolspruit R. T rich ard tsp ru it R . Vi sku ile R . Rie tsp rui t R... . T rich ard tsp ru it R . Figure 1. Sketch map showing the Upper Olifants River catchment with Lake Loskop. Inset map shows the area within South Africa; the dashed line separates the Wilge sub-catchment from the Olifants sub-catchment. SILnews 55...

  14. Physical Habitat Characteristics on the North and South Forks of the Shenandoah River, VA in 2002-2007

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The layers within this geodataset describe physical habitat characteristics in the North and South Fork Shenandoah rivers. They represent conditions during summer...

  15. Habitat preferences of foraging red-cockaded woodpeckers at the Savannah River Site, South Carolina.

    Energy Technology Data Exchange (ETDEWEB)

    Franzreb, Kathleen, E.

    2004-12-31

    Franzreb, Kathleen, E. 2004. Habitat preferences of foraging red-cockaded woodpeckers at the Savannah River Site, South Carolina. In: Red-cockaded woodpecker; Road to Recovery. Proceedings of the 4th Red-cockaded woodpecker Symposium. Ralph Costa and Susan J. Daniels, eds. Savannah, Georgia. January, 2003. Chapter 9. Habitat Management and Habitat Relationships. Pp 553-561. Abstract: I constructed a foraging study to examine habitat use of red-cockaded woodpeckers at the Savannah River Site, South Carolina. Because much of the land had been harvested in the late 1940s and early 1950s prior to being sold to the Department of Energy, the available habitat largely consisted of younger trees (e.g., less than 40 years old). From 1992 to 1995, I examined the foraging behavior and reproductive success of 7 groups of red-cockaded woodpeckers.

  16. Comparison of Methylmercury Ecology in Adjacent Coastal Plain Rivers in South Carolina

    Science.gov (United States)

    Bradley, P. M.; Journey, C. A.; Chapelle, F. H.; Lowery, M. A.; Conrads, P. A.

    2010-12-01

    Fish-tissue mercury concentrations (approximately 2 micrograms per gram) in the Edisto River basin of South Carolina are among the highest recorded in the United States. Substantially lower mercury concentrations (approximately 0.2 microgram per gram) are reported in fish from the adjacent Congaree River sub-basin and the Congaree National Park. Concentrations of total mercury were statistically higher in sediments from the Congaree River compared with those in sediments from the Edisto River. No statistically significant differences were observed in concentrations of methylmercury or in the range of net methylation potentials in sediments collected from various Edisto and Congaree hydrologic settings. In both systems, net methylation potentials were an order of magnitude or more lower in stream-channel sediments than in wetland sediments. These results are not consistent with the hypothesis that differences in fish-tissue mercury between the Edisto and Congaree basins reflect fundamental differences in the potential for each system to methylate mercury. The marked differences in net methylation potential observed between the wetland and in-stream settings suggested an alternative hypothesis: differences in the efficiency of methylmercury transport from zones of production (wetlands) to points of entry into the food chain (channels) contribute to the observed differences in fish-tissue mercury concen¬trations between the two river systems. An assessment of the flood hydrodynamics of these two rivers is consistent with the alternative hypothesis.

  17. Beyond water, beyond boundaries: spaces of water management in the Krishna river basin, South India.

    Science.gov (United States)

    Venot, Jean-Philippe; Bharati, Luna; Giordano, Mark; Molle, François

    2011-01-01

    As demand and competition for water resources increase, the river basin has become the primary unit for water management and planning. While appealing in principle, practical implementation of river basin management and allocation has often been problematic. This paper examines the case of the Krishna basin in South India. It highlights that conflicts over basin water are embedded in a broad reality of planning and development where multiple scales of decisionmaking and non-water issues are at play. While this defines the river basin as a disputed "space of dependence", the river basin has yet to acquire a social reality. It is not yet a "space of engagement" in and for which multiple actors take actions. This explains the endurance of an interstate dispute over the sharing of the Krishna waters and sets limits to what can be achieved through further basin water allocation and adjudication mechanisms – tribunals – that are too narrowly defined. There is a need to extend the domain of negotiation from that of a single river basin to multiple scales and to non-water sectors. Institutional arrangements for basin management need to internalise the political spaces of the Indian polity: the states and the panchayats. This re-scaling process is more likely to shape the river basin as a space of engagement in which partial agreements can be iteratively renegotiated, and constitute a promising alternative to the current interstate stalemate.

  18. Use of artificial stream mesocosms to investigate mercury uptake in the South River, Virginia, USA.

    Science.gov (United States)

    Brent, Robert N; Berberich, David A

    2014-02-01

    Mercury is a globally distributed pollutant that biomagnifies in aquatic food webs. In the United States, 4,769 water bodies fail to meet criteria for safe fish consumption due to mercury bioaccumulation. Although the majority of these water bodies are affected primarily by atmospheric deposition of mercury, legacy contamination from mining or industrial activities also contribute to fish consumption advisories for mercury. The largest mercury impairment in Virginia, a 130-mile stretch of the South and South Fork Shenandoah rivers, is posted with a fish-consumption advisory for mercury contamination that originated from mercuric sulfate discharges from a textile facility in Waynesboro, Virginia, between 1929 and 1950. Although discharges of mercury to the river ceased >60 years ago, mercury levels in fish remain greater than levels safe for human consumption. This is due to the continued cycling of historic mercury in the river and its eventual uptake and biomagnification through aquatic food webs. This study investigated the relative importance of waterborne versus sediment-borne mercury in controlling biological uptake of mercury into the aquatic food web. Twelve artificial stream channels were constructed along the contaminated South River in Crimora, Virginia, and the uncontaminated North River in nearby Port Republic, Virginia, to provide four experimental treatments: a control with no Hg exposure, a Hg in sediment exposure, a Hg in water exposure, and a Hg in sediment and water exposure. After 6 weeks of colonization and growth, algae in each treatment was collected and measured for mercury accumulation. Mercury accumulation in water-only exposures was four times greater than in sediment-only exposures and was equivalent to accumulation in treatments with combined water and sediment exposure. This indicates that mercury in the water column is much more important in controlling biological uptake than mercury in near-field sediments. As a result, future

  19. Climate variability and Ross River virus infections in Riverland, South Australia, 1992-2004.

    Science.gov (United States)

    Bi, P; Hiller, J E; Cameron, A S; Zhang, Y; Givney, R

    2009-10-01

    Ross River virus (RRV) infection is the most common notifiable vector-borne disease in Australia, with around 6000 cases annually. This study aimed to examine the relationship between climate variability and notified RRV infections in the Riverland region of South Australia in order to set up an early warning system for the disease in temperate-climate regions. Notified data of RRV infections were collected by the South Australian Department of Health. Climatic variables and monthly river flow were provided by the Australian Bureau of Meteorology and South Australian Department of Water, Land and Biodiversity Conservation over the period 1992-2004. Spearman correlation and time-series-adjusted Poisson regression analysis were performed. The results indicate that increases in monthly mean minimum and maximum temperatures, monthly total rainfall, monthly mean Southern Oscillation Index and monthly flow in the Murray River increase the likelihood, but an increase in monthly mean relative humidity decreases the likelihood, of disease transmission in the region, with different time-lag effects. This study demonstrates that a useful early warning system can be developed for local regions based on the statistical analysis of readily available climate data. These early warning systems can be utilized by local public health authorities to develop disease prevention and control activities.

  20. South Fork Snake River/Palisades Wildlife Mitigation Project: Environmental assessment

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

    BPA proposes to fund the implementation of the South Fork Snake River Programmatic Management Plan to compensate for losses of wildlife and wildlife habitat due to hydroelectric development at Palisades Dam. The Idaho Department of Fish and Game drafted the plan, which was completed in May 1993. This plan recommends land and conservation easement acquisition and wildlife habitat enhancement measures. These measures would be implemented on selected lands along the South Fork of the Snake River between Palisades Dam and the confluence with the Henry`s Fork, and on portions of the Henry`s Fork located in Bonneville, Madison, and Jefferson Counties, Idaho. BPA has prepared an Environmental Assessment evaluating the proposed project. The EA also incorporates by reference the analyses in the South Fork Snake River Activity/Operations Plan and EA prepared jointly in 1991 by the Bureau of Land Management and the Forest Service. Based on the analysis in the EA, BPA has determined that the proposed action is not a major Federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act (NEPA) of 1969. Therefore, the preparation of an Environmental Impact Statement (EIS) is not required and BPA is issuing this FONSI.

  1. Dependence between sea surge, river flow and precipitation in south and west Britain

    Directory of Open Access Journals (Sweden)

    C. Svensson

    2004-01-01

    Full Text Available Estuaries around Great Britain may be at heightened risk of flooding because of the simultaneous occurrence of extreme sea surge and river flow, both of which may be caused by mid-latitude cyclones. A measure especially suited for extremes was employed to estimate dependence between river flow and sea surge. To assist in the interpretation of why flow-surge dependence occurs in some areas and not in others, the dependence between precipitation and surge and between precipitation and river flow was also studied. Case studies of the meteorological situations leading to high surges and/or river flows were also carried out. The present study concerns catchments draining to the south and west coasts of Great Britain. Statistically significant dependence between river flow and daily maximum sea surge may be found at catchments spread along most of this coastline. However, higher dependence is generally found in catchments in hilly areas with a southerly to westerly aspect. Here, precipitation in south-westerly airflow, which is generally the quadrant of prevailing winds, will be enhanced orographically as the first higher ground is encountered. The sloping catchments may respond quickly to the abundant rainfall and the flow peak may arrive in the estuary on the same day as a large sea surge is produced by the winds and low atmospheric pressure associated with the cyclone. There are three regions where flow-surge dependence is strong: the western part of the English south coast, southern Wales and around the Solway Firth. To reduce the influence of tide-surge interaction on the dependence analysis, the dependence between river flow and daily maximum surge occurring at high tide was estimated. The general pattern of areas with higher dependence is similar to that using the daily maximum surge. The dependence between river flow and daily maximum sea surge is often strongest when surge and flow occur on the same day. The west coast from Wales and

  2. Modeling transportation of suspended solids in Zhujiang River estuary, South China

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiaohong; CHEN Yongqin; LAI Guoyou

    2005-01-01

    A three-dimensional transportation model for suspended solids (SS) in Zhujiang (Pearl) River estuary, South China, was developed by coupling with a three-dimensional hydrodynamic model. The model was validated using hourly measured data of sediment contents during 25-26, July 1999. The results showed that modeled contents matched well with measured ones and that the modeled top layer distribution agreed with the remotely sensed image of suspended solids in summer. The modeled results showed clearly the layers of suspended solids in depth, with larger sediment contents in lower layers though in the interface between salt water and freshwater the lowest contents appeared in middle layer. In overall, the suspended solids inflow from 8 rivers, transport southwestward, and carried by strong coastal flow in Zhujiang River estuary. Contours of sediment contents in the estuary spread further to the open sea during ebb tide rather than flood tide which reflects that the suspended solids in the estuary are land sourced.

  3. Herbicide and nutrient transport from an irrigation district into the South Saskatchewan River.

    Science.gov (United States)

    Cessna, A J; Elliott, J A; Tollefson, L; Nicholaichuk, W

    2001-01-01

    Pesticides and nutrients can be transported from treated agricultural land in irrigation runoff and thus can affect the quality of receiving waters. A 3-yr study was carried out to assess possible detrimental effects on the downstream water quality of the South Saskatchewan River due to herbicide and plant nutrient inputs via drainage water from an irrigation district. Automated water samplers and flow monitors were used to intensively sample the drainage water and to monitor daily flows in two major drainage ditches, which drained approximately 40% of the flood-irrigated land within the irrigation district. Over three years, there were no detectable inputs of ethalfluralin into the river and those of trifluralin were less than 0.002% of the amount applied to flood-irrigated fields. Inputs of MCPA, bromoxynil, dicamba and mecoprop were 0.06% or less of the amounts applied, whereas that for clopyralid was 0.31%. The relatively higher input (1.4%) of 2,4-D to the river was probably due its presence in the irrigation water. Corresponding inputs of P (as total P) and N (as nitrate plus ammonia) were 2.2 and 1.9% of applied fertilizer, respectively. Due to dilution of the drainage water in the river, maximum daily herbicide (with the exception of 2,4-D) and nutrient loadings to the river would not have resulted in significant concentration increases in the river water. There was no consistent remedial effect on herbicides entering the river due to passage of the drainage water through a natural wetland. In contrast, a considerable portion of the nutrients entering the river originated from the wetland.

  4. Developing Depositional Models for Mercury Contaminated Floodplain Deposits Using Geomorphic Mapping and GIS in South River, Virginia

    Science.gov (United States)

    Barbieri, A.; Pizzuto, J.; O'Neal, M. A.; Rhoades, E.

    2007-12-01

    Mercury was introduced into the South River from the 1930s to the 1950s from an industrial plant in Waynesboro, Virginia. Mercury contamination in fish tissue continues to exceed acceptable levels. The contaminated sediments in the river's floodplains are probably the present source of mercury to the South River ecosystem. Locating and determining the extent and depositional history of these deposits are important for understanding the mercury cycle in the river as well as for remediation plans. The South River is a sinuous, single thread alluvial river with frequent bedrock exposures along its bed and banks. Overbank deposits are discontinuous and thin. Rates of lateral migration by the South River are extremely low, averaging 0.02 m/yr, and the river has been influenced by mill dams along a 19 km study reach. This 19 km section of the 37 km river reach was selected for the study because of its high concentration of Hg. Six different categories of floodplain deposits dating from 1937-2005 have been identified throughout the river using studies of historical aerial photographs in a GIS framework, field mapping, dendro- and radionuclide dating, grain size and Hg analysis. Not surprisingly, traditional depositional models of meandering rivers do not apply. Floodplain depositional units include mill dam deposits, point bar/bench deposits, concave bank bench deposits, islands, cattle deposits, and tributary confluences deposits. The most important deposits for sequestering historic mercury are those that also store the most silt and clay. These include mill dam deposits, point bar/bench deposits, concave bank deposits, and tributary confluence deposits. Many of these deposits represent reservoirs of mercury-contaminated sediments that could supply significant amounts of mercury into the river presently and in the future.

  5. Long-Term Changes in the Water Quality and Macroinvertebrate Communities of a Subtropical River in South China

    OpenAIRE

    Kun Li; Chunguang He; Jie Zhuang; Zhenxing Zhang; Hongyong Xiang; Zhongqiang Wang; Haijun Yang; Lianxi Sheng

    2014-01-01

    Subtropical rivers support a highly diverse array of benthic macroinvertebrates. In this study, by combining historical data and new data, we identified specific changes in the Guanlan River, in South China, from 1981 to 2011, and evaluated the effectiveness of an ecological restoration project under highly polluted conditions. From 1981 to 2011, the water quality in the Guanlan River underwent three major stages. With the deterioration of water quality, there was an overall decrease in the s...

  6. Impact of sand mining activities on the environmental condition of the Komering river, South Sumatera

    Science.gov (United States)

    Lusiagustin, V.; Kusratmoko, E.

    2017-07-01

    Sand mining activities in the Komering river, South Sumatera, has been existed around a long time and continues to grow along with the increase of development that occurred in the district of East Ogan Komering Ulu (East OKU). The purpose of this study is to examine the impact of sand mining activities to environmental conditions of the Komering river. Field studies have been conducted during the period of April-June 2016 for observing the condition of the river channel, water quality measurement and mining activities. Analysis of the results of field studies combined with GIS and Remote sensing analysis was conducted to measure the impact of mining activities both spatially and temporally. The results showed that the sand mining activities on the Komering river have led not only to the degradation of water quality but also damage of the river channel. In this paper, we also discussed the relationship between the distribution of water quality and channel damage with the mining activities in the spatial perspective.

  7. A preliminary assessment of the hydrologic characteristics of the James River in South Dakota

    Science.gov (United States)

    Benson, R.D.

    1983-01-01

    The James River in South Dakota has very restricted channel capacities within the Lake Dakota Plain. Channel capacities in Brown County are as little as 200 cubic feet per second, and spring flooding can be expected on an average of every other year. The river has potential for extended periods of flooding an average of once in 10 years. Extended periods of no flow during late-summer and winter also can be expected. Excluding flows of a very large magnitude, average travel time between Columbia and Scotland (a distance of 382 river miles) is estimated to be 25-30 days for most flows. The upstream reach of the James River within the Lake Dakota Plain generally loses discharge with distance whereas the downstream reach generally gains discharge with distance. Ground water - surface water interaction does not appear to be significant along upstream reaches of the James River. Some interaction, although not quantified, does occur in Hanson, Davison, and Yankton Counties. Sand Lake National Wildlife Refuge, located just downsteam from the State line and containing Sand and Mud Lakes (combined capacity = 24,600 acre-feet), is a major source of water loss between LaMoure, N. Dak. and Columbia, S. Dak. Gross evaporation losses from the lakes during 1969-81 is estimated to have been slightly more than 29,000 acre-feet per year. Unaccounted-for losses in the lake system are estimated to have been slightly more than 19,000 acre-feet per year. (USGS)

  8. Hydraulic analysis of a radial collector well for riverbank filtration near Nakdong River, South Korea

    Science.gov (United States)

    Lee, Eunhee; Hyun, Yunjung; Lee, Kang-Kun; Shin, Jiyoun

    2012-05-01

    A radial collector well is used for the extraction of a large amount of groundwater without causing a deep drawdown at the well's center, and it is appropriate for the supply of municipal water through riverbank filtration (RBF). Flow path changes caused by water extraction through a radial collector well were simulated to estimate the amount of river water induction at a RBF site associated with Nakdong River in South Korea. The structure of the screened horizontal arms of a radial collector well was examined with respect to effective riverbank filtration. The relative ratio of the river water induced to the radial collector well compared to the total groundwater extraction was estimated to be 27-52%. The amount of induced river water varies with the distance of a horizontal arm from the river, indicating that the location and structure of the collector well is significant for RBF. In all simulation cases, the maximum drawdown of the groundwater level near the collector well was 2.1 m, which is not significant considering the substantial pumping rate at the study site. It was concluded that RBF radial collector wells can be used at the study site for a sustainable water supply.

  9. Influence of small river derived sediment on the Northeastern South China Sea sedimentation processes in the last 40 K years

    Science.gov (United States)

    Cheng, Wan-Yen; Lin, Saulwood; Lou, Jiann-Yuh; Wei, Kuo-Yen; Liu, CharShine; Chen, Shing-Li; Wang, Yun-Shuen

    2015-04-01

    Small rivers derived particles are major source of sediment to the ocean in the present time. Small rivers in Taiwan are subjected to fast tectonic activity, high precipitation rate and erosion rate. The combined annual river particle load from small rivers on the Island of Taiwan is higher than that of the Mississippi River. A large fraction of those rivers particle may finding its way into the surrounding seas and ocean, e.g. South China Sea, East China Sea, and the Philippine Sea. Furthermore, due to the nature of particle transportation off rivers from Taiwan were connected by a number of canyon systems close by the river mouth, majority of those river particles were facilitated in delivering and deposited later further into the South China Sea deep basin. The objectives of this study are to understand spatial variations in sedimentation rates and to resolve the temporal differences in sedimentation in the Northeastern South China Sea region, and to evaluate influence of small river particles to the marginal sea. A set of cores was collected in overlying water depth within 1600 - 3300 m for mutilsensor core logging of magnetic susceptibility, density, and porosity. Foraminifera (G. sacculifer, G. conglobatus, O. universa) were picked and AMS C14 analyses for age determination. Grain size, organic carbon, carbonate and biogenic silica content were measured. The results show that large sedimentation rates difference existed in the study area. Earlier studies on sedimentation rate in the region west of our study area were in range of about 10 cm/kyr while our rates are about 20-40 cm/kyr and much higher near Taiwan. Bulk sedimentation rate were higher during the transition period between LGM and Holocene and lower during Holocene. Our results demonstrated that large quantity of particles from small rivers in Taiwan are and were major source of particle and are the dominating factor in controlling sediment deposition in the northeastern South China Sea.

  10. The Impact of Human Activities on Microbial Quality of Rivers in the Vhembe District, South Africa

    Directory of Open Access Journals (Sweden)

    Afsatou N. Traoré

    2016-08-01

    Full Text Available Background: Water quality testing is dictated by microbial agents found at the time of sampling in reference to their acceptable risk levels. Human activities might contaminate valuable water resources and add to the microbial load present in water bodies. Therefore, the effects of human activities on the microbial quality of rivers collected from twelve catchments in the Vhembe District in South Africa were investigated, with samples analyzed for total coliform (TC and Eschericha coli (E. coli contents. Methods: Physical parameters and various human activities were recorded for each sampling site. The Quanti-Tray® method was adopted for the assessment of TC and E. coli contents in the rivers over a two-year period. A multiplex polymerase chain (PCR method was used to characterize the strains of E. coli found. Results: The microbial quality of the rivers was poor with both TC and E. coli contents found to be over acceptable limits set by the South African Department of Water and Sanitation (DWS. No significant difference (p > 0.05 was detected between TC and E. coli risks in dry and wet seasons. All six pathogenic E. coli strains were identified and Enteroaggregative E. coli (EAEC, atypical Enteropathogenic E. coli (a-EPEC and Enterotoxigenic E. coli (ETEC were the most prevalent E. coli strains detected (respectively, 87%, 86% and 83%. Conclusions: The study indicated that contamination in the majority of sampling sites, due to human activities such as car wash, animal grazing and farming, poses health risks to communities using the rivers for various domestic chores. It is therefore recommended that more education by the respective departments is done to avert pollution of rivers and prevent health risks to the communities in the Vhembe District.

  11. Occurrence of PPCPs in Pearl River Estuary and South China Sea

    Science.gov (United States)

    Fisch, Kathrin; Waniek, Joanna J.; Schulz-Bull, Detlef E.

    2017-04-01

    The development of a coastal megacity has put the South China Sea under human induced stress. Pharmaceuticals and personal care products (PPCPs) are ubiquitous contaminants and can be used as anthropogenic indicators for pollution of the marine environment. They enter the marine environment indirectly via waste water or directly due to recreational activities. PPCPs make up a group of different pharmaceuticals such as antibiotic, anti-inflammatories etc. and personal care products such as UV-filters. A mayor concern is the unknown fate and the effect these pollutants on the marine environment and especially its organisms. In some studies it was proven that some of these PPCPs have an endocrine disrupting and/or a subtle chronic effect on aquatic organisms. They are of concern for the health of the marine environment and may have an effect on human health. With our study we could determine the occurrence of PPCPs in the Pearl River estuary and the South China Sea. Salicylic acid (metabolite of acetylsalicylic acid) and octocrylene (UV-filter) were found in the open Sea in low ng/L concentration. Octocrylene is used in sunscreen and as a light stabilizer in paints and polymer-based products. It is of environmental concern because of its potential to be bioaccumulative. In addition to our findings in the open South China Sea, could we detect PPCPs, especially antibiotics, in higher ng/L-concentrations in the Pearl River Estuary.

  12. Linking spatial planning, water resources management and biodiversity protection: a case study for the systematic conservation of rivers in South Africa

    CSIR Research Space (South Africa)

    Maree, GA

    2006-03-01

    Full Text Available Results from the National Spatial Biodiversity Assessment (NSBA) have highlighted the poor condition of South Africa's main rivers for conservation of biodiversity and that conservation efforts in South Africa have centred primarily on terrestrial...

  13. Exploration of drought evolution using numerical simulations over the Xijiang (West River) basin in South China

    Science.gov (United States)

    Niu, Jun; Chen, Ji; Sun, Liqun

    2015-07-01

    The knowledge of drought evolution characteristics may aid the decision making process in mitigating drought impacts. This study uses a macro-scale hydrological model, Variable Infiltration Capacity (VIC) model, to simulate terrestrial hydrological processes over the Xijiang (West River) basin in South China. Three drought indices, namely standardized precipitation index (SPI), standardized runoff index (SRI), and soil moisture anomaly index (SMAI), are employed to examine the spatio-temporal and evolution features of drought events. SPI, SRI and SMAI represent meteorological drought, hydrological drought and agricultural drought, respectively. The results reveal that the drought severity depicted by SPI and SRI is similar with increasing timescales; SRI is close to that of SPI in the wet season for the Liu River basin as the high-frequency precipitation is conserved more by runoff; the time lags appear between SPI and SRI due to the delay response of runoff to precipitation variability for the You River basin. The case study in 2010 spring drought further shows that the spatio-temporal evolutions are modulated by the basin-scale topography. There is more consistency between meteorological and hydrological droughts for the fan-like basin with a converged river network. For the west area of the Xijiang basin with the high elevation, the hydrological drought severity is less than meteorological drought during the developing stage. The recovery of hydrological and agricultural droughts is slower than that of meteorological drought for basins with a longer mainstream.

  14. Implication of drainage basin parameters of a tropical river basin of South India

    Science.gov (United States)

    Babu, K. J.; Sreekumar, S.; Aslam, Arish

    2016-03-01

    Drainage morphometry provides quantitative description of the drainage system which is an important aspect of the characterisation of watersheds. Chalakudi River is one of the important rivers of the South India which has attracted attention of many environmental scientists recently because of the proposed Athirapally Hydel Project across the river. SRTM (Shuttle Radar Topographic Mission) data were used for preparing DEM (Digital Elevation Model), Aspect Map and Slope Map. Geographical Information System (GIS) was used for the evaluation of linear, areal and relief aspects of morphometric parameters. The study reveals that the terrain exhibits dentritic and trellis pattern of drainage. The Chalakudi River Basin has a total area of 1,448.73 km2 and is designated as seventh-order basin. The drainage density of the basin is estimated as 2.54 and the lower-order streams mostly dominate the basin. The high basin relief indicates high runoff and sediment transport. The elongation ratio of the Chalakudi Basin is estimated as 0.48 and indicates that the shape of the basin is elongated. The development of stream segments in the basin area is more or less effected by rainfall. Relief ratio indicates that the discharge capability of watershed is very high and the groundwater potential is meagre. The low value of drainage density in spite of mountainous relief indicates that the area is covered by dense vegetation and resistant rocks permeated by fractures and joints. These studies are helpful in watershed development planning and wise utilization of natural resources.

  15. Distribution, sources, and fluxes of heavy metals in the Pearl River Delta, South China.

    Science.gov (United States)

    Geng, Junjie; Wang, Yiping; Luo, Hanjin

    2015-12-30

    Riverine samples were collected at various locations in the Pearl River Delta (PRD) to determine the concentrations of heavy metals (Cr, Ni, Cu, Mn, Zn, Cd, and Pb) in time and space and to estimate the fluxes of heavy metals to the coastal waters off South China. Most of the elements exhibit clear temporal and spatial trends. Principal component analysis shows that surface erosion is the major factor affecting metal concentrations in particulates in the PRD. Natural geology is an important source of these heavy metals. The annual fluxes of Cr, Ni, Cu, Mn, Zn, Cd, and Pb in upstream and downstream were 445, 256, 241, 3293, 1279, 12, and 317 t/year and 1823, 1144, 1786, 15,634, 6183, 74, and 2017 t/year, respectively. A comparison indicated that the annual fluxes of Mn accounted for 1.3% of the global river fluxes, whereas other elements contribute <1%.

  16. Altered river morphology in south africa related to the permian-triassic extinction

    Science.gov (United States)

    Ward; Montgomery; Smith

    2000-09-08

    The Permian-Triassic transition in the Karoo Basin of South Africa was characterized by a rapid and apparently basin-wide change from meandering to braided river systems, as evidenced by preserved sedimentary facies. This radical changeover in river morphology is consistent with geomorphic consequences stemming from a rapid and major die-off of rooted plant life in the basin. Evidence from correlative nonmarine strata elsewhere in the world containing fluvial Permian-Triassic boundary sections suggests that a catastrophic terrestrial die-off of vegetation was a global event, producing a marked increase in sediment yield as well as contributing to the global delta(13)C excursion across the Permian-Triassic boundary.

  17. Eddy-entrained Pearl River plume into the oligotrophic basin of the South China Sea

    Science.gov (United States)

    He, Xianqiang; Xu, Dongfeng; Bai, Yan; Pan, Delu; Chen, Chen-Tung Arthur; Chen, Xiaoyan; Gong, Fang

    2016-08-01

    The South China Sea (SCS) is the world's largest tropical marginal sea with an oligotrophic basin. In June 2015, a rare large phytoplankton bloom, which is ~500 km long, 100 km wide and lasting more than 19 days, was captured in the northern SCS basin by satellite daily chlorophyll images. Water within the bloom area had a feature of low salinity and high temperature measured by an accidental-passing cruise. Meanwhile, satellite sea level anomaly images and drifter trajectory proved there was a cyclonic eddy nearby. No typhoon and heavy rain happened in this period, so we believed the bloom was triggered by the injection of nutrient-rich Pearl River plume driven by eddy. This is the first report on eddy-entrained Pearl River plume into the SCS, which would raise a new view on irregular transportation of nutrient and carbon and its related biogeochemical influence on the oligotrophic ocean.

  18. Clay minerals in surface sediments of the Pearl River drainage basin and their contribution to the South China Sea

    Institute of Scientific and Technical Information of China (English)

    LIU ZhiFei; Christophe COLIN; HUANG Wei; CHEN Zhong; Alain TRENTESAUX; CHEN JianFang

    2007-01-01

    Clay minerals have played a significant role in the study of the East Asian monsoon evolution in the South China Sea by being able to track oceanic current variations and to reveal contemporaneous paleoclimatic changes prevailing in continental source areas. As one of the most important rivers inputting terrigenous matters to the northern South China Sea, the Pearl River was not previously paid attention to from the viewpoint of clay mineralogy. This paper presents a detailed study on clay minerals in surface sediments collected from the Pearl River drainage basin (including all three main channels,various branches, and the Lingdingyang in the estuary) by using the X-ray diffraction (XRD) method.The results indicate that the clay mineral assemblage consists dominantly of kaolinite (35%-65%),lesser abundance of chlorite (20%-35%) and illite (12%-42%), and very scare smectite occurrences (generally <5%). Their respective distribution does not present any obvious difference throughout the Pearl River drainage basin. However, downstream the Pearl River to the northern South China Sea, the clay mineral assemblage varies significantly: kaolinite decreases gradually, smectite and illite increase gradually. Additionally, illite chemistry index steps down and illite crystallinity steps up. These variations indicate the contribution of major kaolinite, lesser illite and chlorite, and very scarce smectite to the northern South China Sea from the Pearl River drainage basin. The maximum contribution of clay minerals from the Pearl River is 72% to the northern margin and only 15% to the northern slope of the South China Sea. In both glacials and interglacials, kaolinite indicates that the ability of mechanical erosion occurred in the Pearl River drainage basin.

  19. Relative sea level in the South Alligator River Region, North Australia, during the Holocene

    Energy Technology Data Exchange (ETDEWEB)

    Woodroffe, C.D.; Thom, B.G.; Chappell, J.; Wallensky, E.; Grindrod, J.; Head, J.

    Mangrove sediments are indicators of former sea level. Radiocarbon dating of fragments of mangrove wood from the sediments of the South Alligator tidal river, van Diemen Gulf, Northern Territory, indicates that sea level rose rapidly during the Postglacial Marine Transgression until about 6800 years B.P., when it was within 5 m of its present level. This is somewhat later than results from northeast and southeast Australia, which show the sea reached its present level before 6000 B.P. Further, we find no evidence for falling sea level in the last 5000 years, which has been reported from eastern and southwestern sites.

  20. Solar Forcing of the Streamflow of a Continental Scale South American River

    CERN Document Server

    Mauas, P J D; Buccino, A P

    2008-01-01

    Solar forcing on climate has been reported in several studies although the evidence so far remains inconclusive. Here, we analyze the stream flow of one of the largest rivers in the world, the Parana in southeastern South America. For the last century, we find a strong correlation with the sunspot number, in multidecadal time scales, and with larger solar activity corresponding to larger stream flow. The correlation coefficient is r=0.78, significant to a 99% level. In shorter time scales we find a strong correlation with El Nino. These results are a step toward flood prediction, which might have great social and economic impacts.

  1. Solar forcing of the stream flow of a continental scale South American river.

    Science.gov (United States)

    Mauas, Pablo J D; Flamenco, Eduardo; Buccino, Andrea P

    2008-10-17

    Solar forcing on climate has been reported in several studies although the evidence so far remains inconclusive. Here, we analyze the stream flow of one of the largest rivers in the world, the Paraná in southeastern South America. For the last century, we find a strong correlation with the sunspot number, in multidecadal time scales, and with larger solar activity corresponding to larger stream flow. The correlation coefficient is r=0.78, significant to a 99% level. In shorter time scales we find a strong correlation with El Niño. These results are a step toward flood prediction, which might have great social and economic impacts.

  2. Insect community structure and function in Upper Three Runs, Savannah River Site, South Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Morse, J.C.; English, W.R. [Clemson Univ., SC (United States). Dept. of Entomology; Looney, B.B. [Westinghouse Savannah River Co., Aiken, SC (United States)

    1993-07-08

    A project to document the insect species in the upper reaches of Upper Three Runs at the Savannah River site was recently completed. This research was supported by the US Department of Energy under the National Environmental Research Park Program. The work was performed by the Department of Entomology at Clemson University in clemson, SC, by John C. Morse (principal investigator), William R. English and their colleagues. The major output from this study was the dissertation of Dr. William R. English entitled ``Ecosystem Dynamics of a South Carolina Sandhills Stream.`` He investigated selected environmental resources and determined their dynamics and the dynamics of the aquatic invertebrate community structure in response to them.

  3. An assessment of the influence of multiple stressors on the Vaal River, South Africa

    Science.gov (United States)

    Wepener, V.; van Dyk, C.; Bervoets, L.; O'Brien, G.; Covaci, A.; Cloete, Y.

    The Vaal River is situated in the mining and industrial heartland of South Africa. It is regarded as a “work horse” river in South Africa and as a consequence it receives treated waste water from the largest metropolitain area in South Africa. It is only with the more frequent occurance of fish kills in the Vaal Barrage area during the past few years that public attention has been drawn towards the decreasing water quality and subsequent deterioration in the aquatic health of the Vaal River system. The aim of this study was to apply a multi-metric approach to assessing the risk of the multiple stressors to fish populations of the Vaal River system. A relative risk assessment approach was applied to divide the Vaal River Barrage into four risk regions. Field sampling was undertaken to validate the predicted risks in each region. The sampling included abiotic (i.e. water and sediment quality) and biotic (fish components) assessment. General water quality parameters (pH, conductivity, dissolved oxygen) together with nutrient, bacteriological and metal concentrations were measured in the four regions. Sediment quality was determined through physical (particle size distribution) and chemical (metal and organic pollutant) analyses. The fish assessment was undertaken at different levels of biological organisation ranging from biomarkers at subcellular levels (cytochrome P450-EROD, metallothionein, acetycholine esterase, antioxidant enzymes, cellular energy), tissue (histopathology), whole organism (fish health index), population and community level. These biological responses were related to environmental exposure through bioaccumulation analyses of metals and organic pollutants in fish tissues. Multivariate statistical analyses were applied to integrate the environmental exposure and effects. The results indicated that those regions that were predicted to be at greatest risk to exposure of multiple stressors did indeed display the greatest disturbance in fish

  4. Survey of blackfly (Diptera: Simuliidae annoyance levels and abundance along the Vaal and Orange Rivers, South Africa

    Directory of Open Access Journals (Sweden)

    Chantel J. de Beer

    2012-07-01

    Full Text Available Blackflies (Diptera: Simuliidae are pests in the livestock and labour-intensive farming systems along the major rivers in South Africa. Since 1995, blackflies have been controlled in the Orange River with the larvicide Bacillus thuringienses var. israelensis (Bti. During 2006–2007, the views of livestock farmers concerning blackfly annoyance were determined by means of questionnaires. The results of the questionnaires were substantiated by seasonal abundance surveys of the sub-adult stages of blackflies, conducted in 2007 at 13 sites in the Orange River and 11 sites in the Vaal River. More than half (52% of the 39 participating farmers along the Orange River and 79% of the 52 participating farmers along the Vaal River stated that they experienced severe blackfly problems. The majority of farmers were unaware of the availability of products that could be used to protect their animals against blackfly attacks and were willing to be involved in blackfly research. High numbers of blackfly sub-adult stages found in both rivers supported the high annoyance levels reported by the respondents. Simulium chutteri, Simulium damnosum s.l., Simulium hargreavesi, Simulium adersi and Simulium alcocki were identified at Christiana and Delportshoop on the Vaal River, whilst S. chutteri, S. damnosum s.l., S. adersi, S. alcocki and Simulium gariepense were identified at Marksdrift and Ses Bridge on the Orange River. Despite the extensive control of blackflies, farmers still experience problems and this contention is supported by surveys conducted along the rivers.

  5. An enhanced adaptive management approach for remediation of legacy mercury in the South River.

    Directory of Open Access Journals (Sweden)

    Christy M Foran

    Full Text Available Uncertainties about future conditions and the effects of chosen actions, as well as increasing resource scarcity, have been driving forces in the utilization of adaptive management strategies. However, many applications of adaptive management have been criticized for a number of shortcomings, including a limited ability to learn from actions and a lack of consideration of stakeholder objectives. To address these criticisms, we supplement existing adaptive management approaches with a decision-analytical approach that first informs the initial selection of management alternatives and then allows for periodic re-evaluation or phased implementation of management alternatives based on monitoring information and incorporation of stakeholder values. We describe the application of this enhanced adaptive management (EAM framework to compare remedial alternatives for mercury in the South River, based on an understanding of the loading and behavior of mercury in the South River near Waynesboro, VA. The outcomes show that the ranking of remedial alternatives is influenced by uncertainty in the mercury loading model, by the relative importance placed on different criteria, and by cost estimates. The process itself demonstrates that a decision model can link project performance criteria, decision-maker preferences, environmental models, and short- and long-term monitoring information with management choices to help shape a remediation approach that provides useful information for adaptive, incremental implementation.

  6. An enhanced adaptive management approach for remediation of legacy mercury in the South River.

    Science.gov (United States)

    Foran, Christy M; Baker, Kelsie M; Grosso, Nancy R; Linkov, Igor

    2015-01-01

    Uncertainties about future conditions and the effects of chosen actions, as well as increasing resource scarcity, have been driving forces in the utilization of adaptive management strategies. However, many applications of adaptive management have been criticized for a number of shortcomings, including a limited ability to learn from actions and a lack of consideration of stakeholder objectives. To address these criticisms, we supplement existing adaptive management approaches with a decision-analytical approach that first informs the initial selection of management alternatives and then allows for periodic re-evaluation or phased implementation of management alternatives based on monitoring information and incorporation of stakeholder values. We describe the application of this enhanced adaptive management (EAM) framework to compare remedial alternatives for mercury in the South River, based on an understanding of the loading and behavior of mercury in the South River near Waynesboro, VA. The outcomes show that the ranking of remedial alternatives is influenced by uncertainty in the mercury loading model, by the relative importance placed on different criteria, and by cost estimates. The process itself demonstrates that a decision model can link project performance criteria, decision-maker preferences, environmental models, and short- and long-term monitoring information with management choices to help shape a remediation approach that provides useful information for adaptive, incremental implementation.

  7. Strontium concentrations and isotope ratios in a forest-river system in the South Qinling Mts., China.

    Science.gov (United States)

    Bu, Hongmei; Song, Xianfang; Zhang, Quanfa; Burford, Michele A

    2016-04-15

    The concentrations of dissolved strontium (Sr) and isotope ratios ((87)Sr/(86)Sr) in rainwater, river water, and water from forest soil are measured to investigate the contributions of these sources to a river during base flow conditions in the relatively pristine South Qinling Mountains, China. Dissolved Sr concentrations and (87)Sr/(86)Sr ratios vary significantly between different water types (p system in a mountainous catchment.

  8. The multiple stressor ecological risk assessment for the mercury-contaminated South River and upper Shenandoah River using the Bayesian network-relative risk model.

    Science.gov (United States)

    Landis, Wayne G; Ayre, Kimberley K; Johns, Annie F; Summers, Heather M; Stinson, Jonah; Harris, Meagan J; Herring, Carlie E; Markiewicz, April J

    2017-01-01

    We have conducted a regional scale risk assessment using the Bayesian Network Relative Risk Model (BN-RRM) to calculate the ecological risks to the South River and upper Shenandoah River study area. Four biological endpoints (smallmouth bass, white sucker, Belted Kingfisher, and Carolina Wren) and 4 abiotic endpoints (Fishing River Use, Swimming River Use, Boating River Use, and Water Quality Standards) were included in this risk assessment, based on stakeholder input. Although mercury (Hg) contamination was the original impetus for the site being remediated, other chemical and physical stressors were evaluated. There were 3 primary conclusions from the BN-RRM results. First, risk varies according to location, type and quality of habitat, and exposure to stressors within the landscape. The patterns of risk can be evaluated with reasonable certitude. Second, overall risk to abiotic endpoints was greater than overall risk to biotic endpoints. By including both biotic and abiotic endpoints, we are able to compare risk to endpoints that represent a wide range of stakeholder values. Third, whereas Hg reduction is the regulatory priority for the South River, Hg is not the only stressor driving risk to the endpoints. Ecological and habitat stressors contribute risk to the endpoints and should be considered when managing this site. This research provides the foundation for evaluating the risks of multiple stressors of the South River to a variety of endpoints. From this foundation, tools for the evaluation of management options and an adaptive management tools have been forged. Integr Environ Assess Manag 2017;13:85-99. © 2016 SETAC.

  9. Hydrological long-term dry and wet periods in the Xijiang River basin, South China

    Directory of Open Access Journals (Sweden)

    T. Fischer

    2013-01-01

    Full Text Available In this study, hydrological long-term dry and wet periods are analyzed for the Xijiang River basin in South China. Daily precipitation data of 118 stations and data on daily discharge at Gaoyao hydrological station at the mouth of the Xijiang River for the period 1961–2007 are used. At a 24-month timescale, the standardized precipitation index (SPI-24 for the six sub-basins of the Xijiang River and the standardized discharge index (SDI-24 for Gaoyao station are applied. The monthly values of the SPI-24 averaged for the Xijiang River basin correlate highly with the monthly values of the SDI-24. Distinct long-term dry and wet sequences can be detected.

    The principal component analysis is applied and shows spatial disparities in dry and wet periods for the six sub-basins. The correlation between the SPI-24 of the six sub-basins and the first principal component score shows that 67% of the variability within the sub-basins can be explained by dry and wet periods in the east of the Xijiang River basin. The spatial dipole conditions (second and third principal component explain spatiotemporal disparities in the variability of dry and wet periods. All sub-basins contribute to hydrological dry periods, while mainly the northeastern sub-basins cause wet periods in the Xijiang River. We can also conclude that long-term dry events are larger in spatial extent and cover all sub-basins while long-term wet events are regional phenomena.

    A spectral analysis is applied for the SPI-24 and the SDI-24. The results show significant peaks in periodicities of 11–14.7 yr, 2.8 yr, 3.4–3.7 yr, and 6.3–7.3 yr. The same periodic cycles can be found in the SPI-24 of the six sub-basins but with some variability in the mean magnitude. A wavelet analysis shows that significant periodicities have been stable over time since the 1980s. Extrapolations of the reconstructed SPI-24 and SDI-24 represent the continuation of observed significant periodicities

  10. Flood risk trends in coastal watersheds in South Spain: direct and indirect impact of river regulation

    Science.gov (United States)

    Egüen, M.; Polo, M. J.; Gulliver, Z.; Contreras, E.; Aguilar, C.; Losada, M. A.

    2015-06-01

    Spain is one of the world's countries with a large number of reservoirs per inhabitant. This intense regulation of the fluvial network during the 20th century has resulted in a decrease in flood events, a higher availability of water resources, and a high development of the irrigated crop area, even in the drier regions. For decades, flood perception was reduced since the development of reservoirs protected the floodplains of river; this resulted in later occupation of soil by urban, agricultural and industrial uses. In recent years, an increasing perception of flood events is observed, associated to the higher damage associated to extreme events in the now occupied areas, especially in coastal watersheds. This work shows the change on flood risk in the coastal areas of three hydrographic basins in Andalusia (South Spain) during the reservoir expansion period: the Guadalete, Guadalquivir and Guadalhorce river basins. The results differentiate the impact of the regulation level on both the cumulative distribution functions of the fluvial discharge near the river mouth, for different time scales, and the associated damage related to the enhanced soil occupation during this period. The different impact on the final medium and long term flood risk is also assessed in terms of the storage capacity per unit area throughout the basins, the effective annual runoff/precipitation index, the frequency of sea storms, and the human factor (change in social perception of floods), for different intervals in the flood extreme regime. The implications for adaptation actions is also assessed.

  11. Simulation of nitrogen and phosphorus loads in the Dongjiang River basin in South China using SWAT

    Institute of Scientific and Technical Information of China (English)

    Yiping WU; Ji CHEN

    2009-01-01

    Population growth, urbanization, and intensi-fied agriculture have resulted in mobilization of nitrogen and phosphorus, which is the main cause of river water quality deterioration. Environmental regulation has expe-dited the necessity for agricultural producers to design and implement more environmentally suitable practices. Therefore, there is a need to identify critical nutrients and their loss/transport potential. Watershed model can be used to better understand the relationship between land use activities/management and hydrologic processes/water quality changes that occur within a watershed. The objective of the study is to test the performance of the SWAT model and the feasibility of using this model as a simulator of water flow and nitrogen and phosphorus yields over the Dongjiang River basin in South China.Spatial data layers of land slope, soil type, and land use were combined with geographic information system (GIS) to aid in creating model inputs. The observed streamflow and sediment at Boluo station in the Dongjiang River basin were used to calibrate and validate the model. Time series plots and statistical measures were used to verify model predictions. Predicted values generally matched well with the observed values during calibration and validation (R2≥0.6 and Nash-Suttcliffe Efficiency ≥0.5) except for underestimation of sediment peaks and overestimation of sediment valleys at Boluo. This study shows that SWAT is able to predict streamflow, sediment generation, and nutrients transport with satisfactory results.

  12. Simplifying dynamic river water quality modelling: A case study of inorganic nitrogen dynamics in the Crocodile River (South Africa).

    CSIR Research Space (South Africa)

    Deksissa, T

    2004-06-01

    Full Text Available and river water quality in the future. A simplified river water quality model was formulated based on a conceptual hydraulic sub-model and simplification of an existing river water quality model. The simplified water quality was derived from the River Water...

  13. Additional mineral resources assessment of the Battle Creek, Bruneau River, Deep Creek-Owyhee River, Jarbidge River, Juniper Creek, Little Owyhee River, North Fork Owyhee River, Owyhee River Canyon, South Fork Owyhee River, Upper Deep Creek, and Yatahoney Creek Wilderness Study Areas, Owyhee County, Idaho

    Science.gov (United States)

    Diggles, Michael F.; Berger, Byron R.; Vander Meulen, Dean B.; Minor, Scott A.; Ach, Jay A.; Sawlan, Michael G.

    1989-01-01

    From 1984 to 1986, studies were conducted to assess the potential for undiscovered mineral resources in wilderness study areas on the Owyhee Plateau. The results of these studies have been published in a series of U.S. Geological Survey Bulletins. Since that time, low-grade, high-tonnage epithermal hot-spring gold-silver deposits have been recognized in the region north of the wilderness study areas. The recognition that this mineral-deposit model is applicable in the region, coupled with new data that has become available to the U.S. Geological Survey, reinterpretation of existing geochemical data, and known-deposit data suggest that similar deposits may be present elsewhere on the Owyhee Plateau. This report is an additional assessment of the Battle Creek, Bruneau River, Deep Creek-Owyhee River, Jarbidge River, Juniper Creek, Little Owyhee River, North Fork Owyhee River, Owyhee River Canyon, South Fork Owyhee River (ID-016-053), Upper Deep Creek, and Yatahoney Creek Wilderness Study Areas in Idaho Wilderness Study Areas in Idaho in light of those new data.

  14. A continental slope stability evaluation in the Zhujiang River Mouth Basin in the South China Sea

    Institute of Scientific and Technical Information of China (English)

    LIU Ke; WANG Jianhua

    2014-01-01

    In nature, a slope stability is determined by the ratio of a sliding resistance to a slide force. The slide force of a marine deep-water continental slope is mainly affected by sediment mechanics properties, a topography, and a marine seismic. However, the sliding resistance is mainly affected by sedimentary patterns and a sedi-mentary stress history. Both of these are different from case to case, and their impact can be addressed when the data are organized in a geographic information system (GIS). The study area on the continental slope in Zhujiang River Mouth Basin in South China Sea provides an excellent opportunity to apply GIS spatial analysis technology for the evaluation of the slope stability. In this area, a continental slope topography and a three-dimension (3-D) topography mapping show a sea-floor morphology and the distribution of a slope steepness in good detail, and the sediment analysis of seabed samples and an indoor appraisal reveals the variability of a sediment density near the sea-floor surface. On the basis of the results of nine geotechnical studies of submarine study areas, it has worked out that an equivalent cyclic shear stress ratio is roughly between 0.158 and 0.933, which is mainly depending on the initial water content of sediment. A regional density, slope and level of anticipated seismic shaking information are combined in a GIS framework to yield a map that illustrates a continental slope stability zoning under the influencing factors in Zhujiang River Mouth Basin in the South China Sea. The continental slope stability evaluation can contribute to north resources development in the South China Sea, the marine functional zoning, the marine engineering con-struction and adjust measures to local conditions, at the same time also can provide references for other deep-water slope stability analysis.

  15. Hydropower Ambitions of South Asian Nations: Ganges and Brahmaputra River basins

    Science.gov (United States)

    Mizanur Rahaman, Muhammad

    2010-05-01

    This paper analyses the current status of hydropower development in two major river basins in South Asia, the Ganges and the Brahmaputra. The total drainage area of the basins is about 1660,000 km2 shared by China, Nepal, India, Bhutan, and Bangladesh. The basins are blessed with ample water resources and huge hydropower potential. Hydropower development is strongly linked with the overall development framework of the region. The abundant hydropower potential of the Ganges and the Brahmaputra can help give riparian countries a safer energy future that is the key driving force behind the prospect of potential cooperation in the field of water. Based on four years research studies (2005-2009), this paper analyse the hydropower development plans and ambitions of riparian nations with special focus on China and India. The finding suggests that it is essential to develop an integrated hydropower development approach involving all riparian nations intended to foster regional development and overcome the prospect of severe conflict because of unilateral hydropower ambitions of China and India. The hydropower development cooperation between China and India could also become the positive turning point in the integration of South and South-East Asia.

  16. Groundwater as an emergency source for drought mitigation in the Crocodile River catchment, South Africa

    Directory of Open Access Journals (Sweden)

    F. E. F. Mussá

    2014-03-01

    and environmental damages to the society. In this study, we assess the drought intensity and severity and the groundwater potential to be used as a supplement source of water to mitigate drought impacts in the Crocodile River catchment, a water-stressed sub-catchment of the Incomati River catchment in South Africa. The research methodology consists mainly of three parts. First, the spatial and temporal variation of the meteorological and hydrological drought severity and intensity over the catchment were evaluated. The Standardized Precipitation Index (SPI was used to analyse the meteorological drought and the Standardized Runoff Index (SRI was used for the hydrological drought. Second, the water deficit in the catchment during the drought period was computed using a simple water balance method. Finally, a groundwater model was constructed in order to assess the feasibility of using groundwater as an emergency source for drought impact mitigation. Results show that the meteorological drought severity varies accordingly with the precipitation; the low rainfall areas are more vulnerable to severe meteorological droughts (lower and upper crocodile. Moreover, the most water stressed sub-catchments with high level of water uses but limited storage, such as the Kaap located in the middle catchment and the Lower Crocodile sub-catchments are those which are more vulnerable to severe hydrological droughts. The analysis of the potential groundwater use during droughts showed that a deficit of 97 Mm3 yr−1 could be supplied from groundwater without considerable adverse impacts on the river base flow and groundwater storage. Abstraction simulations for different scenarios of extremely severe droughts reveal that it is possible to use groundwater to cope with the droughts in the catchment. However, local groundwater exploitation in Nelspruit and White River sub-catchment will cause large drawdowns (> 10 m and high base flow reduction (> 20%. This case study shows that

  17. The characteristics of nutrients and eutrophication in the Pearl River estuary, South China.

    Science.gov (United States)

    Huang, X P; Huang, L M; Yue, W Z

    2003-01-01

    In the spring of 1998, 24-h time series and synchronization of vertical profiles of NO(3)-N, NO(2)-N, NH(3)-N, PO(4)-P, chlorophyll a, suspended substance, salinity, temperature and other chemical parameters were taken at 10 stations in the Pearl River estuary in order to analyze the status and characteristics of nutrients and eutrophication. The results indicated that dissolved inorganic nitrogen (DIN) mainly came from the four river channels in the main estuary, and NO(3)-N was the main form of DIN in most area. The concentration of DIN was general above 0.30 mg l(-1) in the estuary, and more than 0.50 mgl(-1) in most part. Phosphate from four river channels was not the main sources, but land-based sources from the area near Shenzhen Bay or along the estuary were obvious, and other land-based sources outside the estuary brought by coastal current and flood tide current were also the main contributions. The concentration of phosphate was generally about 0.015 mg l(-1) except the area near Shenzhen Bay. The ratio of N:P was generally high, and it was higher in the north than in the south. The highest ratio was higher than 300, and the lowest one was over 30. The concentration of chlorophyll a was about 0.8-7.8 mg m(-3), and turbidity and phosphate may be the main two limiting factors for algal bloom in the estuary. The concentration of nutrients decreased slightly in the past decade, but still stayed at a high level. The nutrients mainly came from domestic sewage, industrial wastewater, agriculture fertilizer and marine culture in the Pearl River estuary.

  18. A Reconnaissance for Emerging Contaminants in the South Branch Potomac River, Cacapon River, and Williams River Basins, West Virginia, April-October 2004

    Science.gov (United States)

    Chambers, Douglas B.; Leiker, Thomas J.

    2006-01-01

    In 2003 a team of scientists from West Virginia Division of Natural Resources and the U. S. Geological Survey found a high incidence of an intersex condition, oocytes in the testes, among smallmouth bass (Micropterus dolomieu) in the South Branch Potomac River and the Cacapon River of West Virginia, indicating the possible presence of endocrine-disrupting compounds (EDCs). Possible sources of EDCs include municipal and domestic wastewater, and agricultural and industrial activities. Several sampling strategies were used to identify emerging contaminants, including potential EDCs, and their possible sources in these river basins and at an out-of-basin reference site. Passive water-sampling devices, which accumulate in-stream organic chemical compounds, were deployed for 40-41 days at 8 sampling sites. Sampler extracts were analyzed for a broad range of polar and non-polar organic compounds including pesticides, flame retardants, pharmaceuticals, and personal-care products. Analysis of passive-sampler extracts found 4 compounds; hexachloro-benzene; pentachloroanisole; 2,2',4,4',5-penta-bromo-diphenyl ether (BDE 47); and 2,2',4,4',6-penta-bromo-diphenyl ether (BDE 99) to be present at every sampled site, including the reference site, and several sites had detectable quantities of other compounds. No detectable quantity of any antibiotics was found in any passive-sampler extract. Effluent samples were analyzed for 39 antibiotics as tracers of human and agricultural waste. Additionally, poultry-processing plant effluent was sampled for roxarsone, an organoarsenic compound used as a poultry-feed additive, and other arsenic species as tracers of poultry waste. Antibiotics were detected in municipal wastewater, aquaculture, and poultry-processing effluent, with the highest number of antibiotics and the greatest concentrations found in municipal effluent. Arsenate was the only arsenic species detected in the poultry-processing plant effluent, at a concentration of 1.0 ?g

  19. A Concept for a Long Term Hydrologic Observatory in the South Platte River Basin

    Science.gov (United States)

    Ramirez, J. A.

    2004-12-01

    The intersection between: (1) the Rocky Mountains and developments occurring in high altitude fragile environments; (2) the metropolitan areas emerging at the interface of the mountains and the plains; (3) the irrigation occurring along rivers as they break from the mountains and snake across the Great Plains; and (4) the grasslands and the dryland farming that covers the vast amount of the Great Plains, represents a dynamic, complex, highly integrated ecosystem, stretching from Montana and North Dakota to New Mexico and Texas. This swath of land, and the rivers that cross it (headwaters of the Missouri , the Yellowstone, the North Platte , the South Platte, the Arkansas , the Cimarron, the Red and the Pecos Rivers ), represent a significant percentage of the landmass of the United States. Within this large area, besides tremendous increases in population in metropolitan areas, there are new energy developments, old hard rock mining concerns, new recreation developments, irrigation farms selling water to meet urban demands, new in-stream flow programs, struggling rural areas, and continued "mining" of ground water. The corresponding impacts are creating endangered and threatened species conflicts which require new knowledge to fully understand the measures needed to mitigate harmful ecosystem conditions. Within the Rocky Mountain/Great Plains interface, water is limiting and land is plentiful, presenting natural resource managers with a number of unique problems which demand a scale of integrated science not achieved in the past. For example, water is imported into a number of the streams flowing east from the Rocky Mountains. Nitrogen is deposited in pristine watersheds that rise up high in the Rocky Mountains. Cities capture spring runoff in reservoirs to use at a steady rate over the entire year, putting water into river systems normally moving low flows in the winter. Irrigation of both urban landscapes and farm fields may be at a scale that impacts climate

  20. Runoff-related agricultural impact in relation to macroinvertebrate communities of the Lourens River, South Africa.

    Science.gov (United States)

    Thiere, Geraldine; Schulz, Ralf

    2004-07-01

    A field study at the Lourens River, South Africa, was undertaken during the pesticide application period between November 2001 and January 2002 in order to investigate the potential relation of agricultural pollution to the aquatic macroinvertebrate fauna. The upper regions of the Lourens River were free of contamination (LR1), whereas subsequent stretches flowing through a 400-ha orchard area (LR2) received transient insecticide peaks. Continuously operating suspended-particle samplers as well as flood samplers operating during runoff events were used to measure pesticide contamination. In addition, various physicochemical and morphological parameters were examined. A survey of the macroinvertebrate communities associated with the rocky substrates was carried out every three weeks. Community indices were calculated using the South African Scoring System (SASS 5) for bioassessment of water quality in rivers. The two sites differed in pesticide pollution as well as in average turbidity levels (LR1 5.5 mg/L; LR2 64.3 mg/L), but were similar in bottom substrate composition and most other abiotic factors. At the downstream site (LR2), pesticide values of 0.05 microg/L azinphos-methyl in water as well as 49 microg/kg azinphos-methyl, 94 microg/kg chlorpyrifos and 122 microg/kg total endosulfan in suspended particles were found during runoff conditions. The macroinvertebrate communities of the two sampling sites were similar in terms of number of total individuals, but differed significantly (ANOVA) in average number of taxa (LR1 11.7, LR2 8.9). Seven out of 17 investigated taxa occurred in significantly reduced numbers or were even absent at the downstream site LR2. The community characteristics determined by SASS 5 showed a significantly less sensitive community structure at the downstream site (TS 41; ASPT 4.6), indicating continuously lower water quality compared to site LR1 (TS 80; ASPT 6.9). It is concluded that the Lourens River macroinvertebrate communities are

  1. Hydrogeologic framework of the Wood River Valley aquifer system, south-central Idaho

    Science.gov (United States)

    Bartolino, James R.; Adkins, Candice B.

    2012-01-01

    metamorphosed to some degree, thus rock types and their relationships vary over distance. Quaternary-age sediment and basalt compose the primary source of groundwater in the Wood River Valley aquifer system. These Quaternary deposits can be divided into three units: a coarse-grained sand and gravel unit, a fine-grained silt and clay unit, and a single basalt unit. The fine- and coarse-grained units were primarily deposited as alluvium derived from glaciation in the surrounding mountains and upper reaches of tributary canyons. The basalt unit is found in the southeastern Bellevue fan area and is composed of two flows of different ages. Most of the groundwater produced from the Wood River Valley aquifer system is from the coarse-grained deposits. The altitude of the pre-Quaternary bedrock surface in the Wood River Valley was compiled from about 1,000 well-driller reports for boreholes drilled to bedrock and about 70 Horizontal-to-Vertical Spectral Ratio (HVSR) ambient-noise measurements. The bedrock surface generally mimics the land surface by decreasing down tributary canyons and the main valley from north to south; it ranges from more than 6,700 feet in Baker Creek to less than 4,600 feet in the central Bellevue fan. Most of the south-central portion of the Bellevue fan is underlain by an apparent topographically closed area on the bedrock surface that appears to drain to the southwest towards Stanton Crossing. Quaternary sediment thickness ranges from less than a foot on main and tributary valley margins to about 350 feet in the central Bellevue fan. Hydraulic conductivity for 81 wells in the study area was estimated from well-performance tests reported on well-driller reports. Estimated hydraulic conductivity for 79 wells completed in alluvium ranges from 1,900 feet per day (ft/d) along Warm Springs Creek to less than 1 ft/d in upper Croy Canyon. A well completed in bedrock had an estimated hydraulic conductivity value of 10 ft/d, one well completed in basalt had a value of

  2. Surficial sediment distribution and the associated net sediment transport pattern in the Pearl River Estuary, South China

    NARCIS (Netherlands)

    Zhang, W.; Zheng, J.H.; Ji, X.M.; Hoitink, A.J.F.; van der Vegt, M.

    2013-01-01

    Spatial variations in grain-size parameters contain information on sediment transport patterns. Therefore, in this study, 106 surficial sediment samples taken from the Pearl River Estuary (PRE), South China, were analyzed, to better understand the net sediment transport pattern in this region. The P

  3. Hydrobiological studies in the catchment of Vaal dam, South Africa. Part 1. River Zonation and the Benthic Fauna

    CSIR Research Space (South Africa)

    Chutter, FM

    1970-01-01

    Full Text Available Vaal Dam is situated on the elevated plateau which forms the interior of South Africa and is a little less than 1500 m above the level. The source of the most of the streams and rivers flowing into the dam are about 2000 m above sea level, though...

  4. 76 FR 70480 - Otay River Estuary Restoration Project, South San Diego Bay Unit of the San Diego Bay National...

    Science.gov (United States)

    2011-11-14

    ... Fish and Wildlife Service Otay River Estuary Restoration Project, South San Diego Bay Unit of the San Diego Bay National Wildlife Refuge, California; Environmental Impact Statement AGENCY: Fish and Wildlife... the San Diego Bay National Wildlife Refuge. This notice advises the public that we intend to gather...

  5. Flooding in the South Platte River and Fountain Creek Basins in eastern Colorado, September 9–18, 2013

    Science.gov (United States)

    Kimbrough, Robert A.; Holmes, Jr., Robert R.

    2015-11-25

    On September 9, 2013, rain began to fall in eastern Colorado as a large low-pressure system pulled plumes of tropical moisture northward from the Pacific Ocean and the Gulf of Mexico. By September 16, 2013, as much as 12 to 20 inches of rain had fallen in the foothills of the Front Range of the Southern Rocky Mountains and adjacent plains near Colorado Springs, Colorado, north to the Colorado-Wyoming border. The rain caused major flooding during September 9–18, 2013, in a large part of the South Platte River Basin and in the Fountain Creek Basin. The floods resulted in several fatalities, more than 31,000 damaged or destroyed structures, and an estimated 3 billion dollars in damages. The U.S. Geological Survey (USGS) documented peak stage, streamflow, or both from the flood event for 80 sites located on selected rivers and streams in the South Platte River and Fountain Creek Basins and on the Platte River in Nebraska. The majority of flood-peak streamflows occurred on September 12 or 13, 2013, coinciding with the period of maximum rainfall. The flood resulted in new record peak streamflows at 17 streamgages having at least 10 years of record; 13 in the South Platte River Basin and 4 in the Fountain Creek Basin.

  6. A review of environmental and human exposure to persistent organic pollutants in the Pearl River Delta, South China.

    Science.gov (United States)

    Zhang, Kai; Wei, Yan-Li; Zeng, Eddy Y

    2013-10-01

    Rapid economic growth in South China (including Guangdong Province, Hong Kong, and Macau), particularly within the Pearl River Delta region, has resulted in severe pollution of the natural eco-environment in the last three decades. Large amounts of monitoring data on organic pollution in the Pearl River Delta have been accumulated, which allows us to conduct a fairly comprehensive assessment of the state of the Pearl River Delta and elucidate spatial and temporal patterns of pollution on a regional scale. Of various causes for environmental deterioration, negative impact from persistent organic pollutants (POPs) is a global concern. This review examines the current levels and distribution patterns of several POPs, namely DDT (and its metabolites DDD and DDE), hexachlorocyclohexanes, and polybrominated diphenyl ethers, in various environmental compartments of South China. The general information on environmental occurrence, regional behaviors, ecological effects, and human exposure of these POPs in this region are reviewed.

  7. Point and Fixed Plot Sampling Inventory Estimates at the Savannah River Site, South Carolina.

    Energy Technology Data Exchange (ETDEWEB)

    Parresol, Bernard, R.

    2004-02-01

    This report provides calculation of systematic point sampling volume estimates for trees greater than or equal to 5 inches diameter breast height (dbh) and fixed radius plot volume estimates for trees < 5 inches dbh at the Savannah River Site (SRS), Aiken County, South Carolina. The inventory of 622 plots was started in March 1999 and completed in January 2002 (Figure 1). Estimates are given in cubic foot volume. The analyses are presented in a series of Tables and Figures. In addition, a preliminary analysis of fuel levels on the SRS is given, based on depth measurements of the duff and litter layers on the 622 inventory plots plus line transect samples of down coarse woody material. Potential standing live fuels are also included. The fuels analyses are presented in a series of tables.

  8. Low-flow frequency and flow duration of selected South Carolina streams in the Broad River basin through March 2008

    Science.gov (United States)

    Guimaraes, Wladmir B.; Feaster, Toby D.

    2010-01-01

    In 2008, the U.S. Geological Survey, in cooperation with the South Carolina Department of Health and Environmental Control, initiated a study to update low-flow statistics at continuous-record streamgaging stations operated by the U.S. Geological Survey in South Carolina. This report presents the low-flow statistics for 23 selected streamgaging stations in the Broad River basin in South Carolina, and includes flow durations of 5-, 10-, 25-, 50-, 75-, 90-, and 95-percent probability of exceedance and the annual minimum 1-, 3-, 7-, 14-, 30-, 60-, and 90-day mean flows with recurrence intervals of 2, 5, 10, 20, 30, and 50 years, depending on the length of record available at the streamgaging station. The low-flow statistics were computed from records available through March 31, 2008. In addition, flow duration information is presented for one streamgaging station 021556525, Pacolet River below Lake Blalock near Cowpens, SC, where recurrence interval computations were not appropriate.

  9. Plant communities along the Eerste River, Western Cape, South Africa: Community descriptions and implications for restoration

    Directory of Open Access Journals (Sweden)

    Clifton S. Meek

    2013-03-01

    Full Text Available Riparian plant communities fulfil many functions, including the provision of corridors linking protected areas and other zones of high conservation value. These habitats across much of South Africa’s Cape Floristic Region, especially in the lowlands, have been heavily impacted and degraded by human activities. There is increasing interest in the restoration of degraded riparian zones and the ecosystem services they provide to enhance the conservation value of landscapes. Previous studies of riparian vegetation in the Cape Floristic Region focused on pristine headwater systems, and little is known about human-impacted communities that make up most of the riparian vegetation in downstream areas. More information is needed on the composition of these plant communities to establish a baseline for management intervention. The riparian zone of the Eerste River in South Africa’s Western Cape province provides a good opportunity to study the features of riparian vegetation along the entire gradient, from pristine vegetation in a protected area through different levels of human-mediated degradation. Riparian vegetation was surveyed in 150 plots along the entire length of the Eerste River (ca. 40 km. Data were analysed using the vegetation classification and analysis software package JUICE. Final groupings were plotted onto a two-dimensional detrended correspondence analysis plane to check the position of the communities in the reduced multidimensional space. Ten distinct plant communities were identified, including several novel communities dominated by alien plant species. Descriptions of each plant community are presented. Diagnostic, constant and dominant species are listed and the major structural and ecological characteristics of each community are described. Conservation implications: Major changes to hydrological and soil properties, nutrient dynamics and disturbance regimes and plant species composition along sections of the riparian zone

  10. Magnetic properties of sediments from the Pearl River Delta,South China:Paleoenvironmental implications

    Institute of Scientific and Technical Information of China (English)

    Rodney; GRAPES

    2008-01-01

    Magnetic parameters and their environmental implications of sediments in a core (PD) from the Pearl River Delta, South China, indicate that ferrimagnetic minerals with low coercivity, such as magnetite, dominate the magnetic properties although small amounts of Fe-sulphides occur. The fraction of Fe-sulphides increases and becomes the dominant minerals determining the magnetic characteristics in grey-black organic-rich clay horizons, indicating an anoxic, sulphate-reducing swamp environment resulting from a marine regression. In the "Huaban clay" , hard magnetic minerals, such as hematite and goethite, largely control the magnetic properties of the sediments and imply a long period of exposure and weathering. Where magnetite is the main magnetic mineral, its fraction and grain size determine properties such as magnetic susceptibility (κ ) and saturation isothermal remanent magnetization (SIRM). Ratios of SIRM/κ and χarm/SIRM reflect changes in sea level with high SIRM/κ and χarm/SIRM correlating with a smaller magnetic mineral grain size and rising sea level. Based on downcore variations of these environmental magnetic parameters along with sediment characteristics and microfauna, the sedimentary environment of the Pearl River Delta area can be divided into two main cycles of transgression and regression during the late Pleistocene and Holocene with more sub-cycles of sea level fluctuation during each transgression.

  11. An evaluation of age estimation using teeth from South Asian River dolphins (Platanistidae

    Directory of Open Access Journals (Sweden)

    Christina H Lockyer

    2014-12-01

    Full Text Available The South Asian river dolphins (Platanista gangetica minor and P. g. gangetica are endangered, geographically isolated, freshwater cetaceans. Accurate age estimation of individuals is an important aspect of population biology as it is used for calculating parameters such as age at maturity and reproduction, longevity, and growth and survival rates. However this has never been comprehensively studied for this endangered cetacean family. A sample of 41 teeth from 29 skulls stored in museum collections was available. We compared two different aging methods to select the most appropriate. This involved decalcification and freeze-sectioning of teeth at variable thicknesses (10–25 micron, and staining with 1 Toluidine Blue, or 2 Ehrlichs Acid Haematoxylin. Stains were then compared for readability of Growth Layer Groups (GLG. The optimum section was found at 20 micron using Erhlichs Acid Haematoxylin. Both dentinal and cemental GLG were readable and comparable, but cemental GLG were generally easier to interpret because they were better defined. Ages varied from newborn / young of year (with none or only a neonatal line present to a maximum age of 30 GLG. There is currently no validation available for GLG deposition rate, but it is likely annual because of the extreme seasonal changes in the river habitat.

  12. Natural radioactivity and metal contamination of river sediments in the Calabria region, south of Italy

    Science.gov (United States)

    Caridi, F.; Marguccio, S.; D'Agostino, M.; Belvedere, A.; Belmusto, G.

    2016-05-01

    River sediments from eight different sites of the coast of Calabria, south of Italy, were sampled to determine natural radioactivity and metal concentrations, in order to assess any possible radiological hazard, the level of contamination and the possible anthropogenic impact in the area. Gamma and X-ray fluorescence (XRF) spectrometry were employed and results of this study show that the mean activity concentrations of radium (in secular equilibrium with uranium) ranged from 15.1Bq/kg to 26.7Bq/kg, that of thorium from 21.8Bq/kg to 48.3Bq/kg and that of potassium from 541.3Bq/kg to 1452.2Bq/kg. In terms of mean mass concentrations, XRF analysis revealed that uranium was lower than 1.5ppm (minimum detectable value), thorium ranged from 6.1ppm to 10.3ppm while potassium ranged from 2.5% to 4.4%. The degree of sediment contaminations were computed using an enrichment factor (EF) and geoaccumulation index ( I geo for some potential hazardous elements. Results suggested that enrichment factor and geoaccumulation values of Pb and Mn were greatest among the studied metals. The study revealed that on the basis of computed indexes, the eight investigated rivers can be classified as no polluted ones.

  13. Magnetic properties of sediments from the Pearl River Delta, South China: Paleoenvironmental implications

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Magnetic parameters and their environmental implications of sediments in a core (PD) from the Pearl River Delta, South China, indicate that ferrimagnetic minerals with low coercivity, such as magnetite, dominate the magnetic properties although small amounts of Fe-sulphides occur. The fraction of Fe-sulphides increases and becomes the dominant minerals determining the magnetic characteristics in grey-black organic-rich clay horizons, indicating an anoxic, sulphate-reducing swamp environment resulting from a marine regression. In the "Huaban clay", hard magnetic minerals, such as hematite and goethite, largely control the magnetic properties of the sediments and imply a long period of exposure and weathering. Where magnetite is the main magnetic mineral, its fraction and grain size determine properties such as magnetic susceptibility (κ) and saturation isothermal remanent magnetization (SIRM). Ratios of SIRM/κ and χarm/SIRM reflect changes in sea level with high SIRM/κ and χarm/SIRM correlating with a smaller magnetic mineral grain size and rising sea level. Based on downcore variations of these environmental magnetic parameters along with sediment characteristics and microfauna, the sedimentary environment of the Pearl River Delta area can be divided into two main cycles of transgression and regression during the late Pleistocene and Holocene with more sub-cycles of sea level fluctuation during each transgression.

  14. Potential toxic risk of heavy metals from sediment of the Pearl River in South China

    Institute of Scientific and Technical Information of China (English)

    NIU Hongyi; DENG Wenjing; WU Qunhe; CHEN Xingeng

    2009-01-01

    Based on the monitoring of five heavy metal elements in the surface sediments of the Pearl River in South China, potential toxicity of the heavy metals was assessed using consensus-based sediment quality guidelines (SQGs) method and compared with geo-accumulation (Igeo) index method.The monitoring results showed the heavy metal concentrations were significantly and positively correlated with each other, demonstrating a common trend in variation of concentration in the surface sediments.The assessment using the consensus-based SQGs method showed the potential toxicity of Cu was the highest, and Cd was the lowest.The evaluation based on mean probable effect concentration (PEC) quotient showed the region was seriously polluted with high toxicity heavy metals.Correlation analysis revealed a significant and positive correlation between the mean PEC quotient and the average of Igeo with a correlation coefficient of 0.926 (n = 23, P < 0.01).In conclusion, the consensus-based SQGs and mean PEC quotient are applicable to assessment of potential toxicity risks of heavy metals in freshwater sediments in the Pearl River.

  15. Trend analysis of nutrient loadings in the South Saskatchewan River catchment

    Science.gov (United States)

    Morales-Marin, L. A.; Chun, K. P.; Wheater, H. S.; Lindenschmidt, K. E.

    2015-12-01

    Nutrient loadings in river catchments have increased in the past years as a consequence of rapid expansion of agricultural areas, new urban developments and industries, and population growth. Nutrient enrichment of water bodies has intensified eutrophication conditions that degrade water quality and ecosystem health. In large-scale catchments, the assessment of temporal and spatial variability of nutrient loads imply challenges due to climate, land use and geology heterogeneity, and to anthropogenic changes. In this study we carried out a trend analysis of total phosphorus and total nitrogen loads in the South Saskatchewan River (SSR) catchment. This catchment is located in the Canadian Prairie Provinces of Alberta and Saskatchewan. The eastern and central areas of the catchment consist mostly of croplands, pasture lands and livestock farms, whereas the western parts are located on the Rocky Mountains that are the source of most of the catchment's streamflows. The trend analysis was performed applying a novel approach to analyse nutrient time series recorded at long-term water quality stations along the main stems of the SSR river network. Since water quality is taken infrequently, in the proposed approach the time series were complemented using regression analysis methods based on streamflow data recorded at the nearest gauge stations. The time series were subsequently pre-whitened in order to remove the autocorrelation, and then subjected to non-parametric statistical test to detect trends. Seasonal analysis of trends at each of the water quality stations were performed in order to determine the relationships between annual flow regimes and nutrient loads in the catchment, in particular, the influence of the high spring runoff on nutrient export. Decadal analysis was also performed to determine the long-tern relationships of nutrients with anthropogenic changes in the catchment. In particular, the capacity of reservoirs to trap nutrients and the effects of the

  16. Artisanal Fisheries in the Ndumo Area of the Lower Phongolo River Floodplain, South Africa

    Directory of Open Access Journals (Sweden)

    Hendri C. Coetzee

    2015-03-01

    Full Text Available The aim of this study was to investigate the status of artisanal fisheries in the lower Phongolo River floodplain in northern KwaZulu-Natal, South Africa. A cross-sectional quantitative survey design was used that included the development of a questionnaire and a systematic survey among the five villages bordering the Ndumo Game Reserve. Data were collected over a 5-day period by a group of 16 fieldworkers and analysed using the Statistical Package for the Social Sciences, version 21. The results revealed that fish was the third most consumed protein in the area, that people consumed fish on average twice a week, that at least six fish species (and one recently introduced crayfish species were consumed regularly, and that most fish were obtained from local vendors, who in turn bought it from local fishermen and -women. Fishing activities also appeared to occur predominantly along the river system and targeted mainly red-breasted tilapia (Tilapia rendalli and Mozambique tilapia (Oreochromis mossambicus and, to a slightly lesser extent, African sharptooth catfish (Clarias gariepinus and brown squeaker (Synodontis zambezensis.Conservation implications: Given that Ndumo residents predominantly catch fish by means of non-commercial methods, that they do so for reasons of personal consumption and subsistence, and that they mostly target rivers and dams rather than the ecologically sensitive pans in the region, it would seem likely that fishing in the region might be sustainable for the moment. However, it is recommended that studies on the local fish populations and their reproductive rates be conducted so that the actual impact on local fish populations can be determined more accurately. This study serves to provide the necessary baseline data on fish utilisation in the region, which would enable the impact of artisanal fishing on fish reserves in the Ndumo region to be determined once population studies have been completed.

  17. ENSO signals in South America. Rains and floods in the Parana River region during colonial times

    Energy Technology Data Exchange (ETDEWEB)

    Del Rosario Prieto, M. [Unit of Environmental History, Argentine Institute of Snow, Glaciers and Environmental Sciences IANIGLA CRICYT, Ruiz Leal s/n, Parque Gral San Martin, 5500 Mendoza (Argentina)

    2007-07-15

    Several studies show that the El Nino-Southern Oscillation (ENSO) is an important factor in determining interannual rainfall variability in South America. This signal is detected in the region including Northeastern Argentina, Uruguay and part of southern Brazil, in the form of excessive rains and big floods in the regional rivers. To check that this relationship was similar in the past the objectives of this paper were to construct a time series of large floods in the Parana River region from documentary records, during the sixteenth to eighteenth centuries, and to evaluate the relationship between that historical record of extreme floods, the ENSO documentary evidence (Ortlieb, The Documented Historical Record of El Nino Events in Peru: An Update of the Quinn Record (Ortlieb, sixteenth through nineteenth centuries, Diaz and Markgraf, (eds.), El Nino and the southern oscillation. Multiscale variability and global and regional Impacts. Cambridge University Press, pp. 207-295, 2001; Quinn and Neal, The historical record of El Nino events, Bradley and Jones (eds.), Climate since a.d. 1500, Routledges, pp. 623-648, 1992) and the temperature index of the Pacific Ocean (Mann ME et al., Global temperature patterns in past centuries: an interactive presentation, IGBP pages/world data center for paleoclimatology data contribution series no. 2000-075. NOAA/NGDC Paleoclimatology Program, Boulder CO, USA, 2000). Considering that the period 1904-2000, where 11 out of 16 floods occurred during El Nino events, it can be concluded that the proportion of years with exceptional flow volume in the Parana River in years with El Nino events in the seventeenth and eighteenth centuries was relatively lower than that of the twentieth century. The reason for this difference is discussed.

  18. Radionuclides and metals in freshwater mussels of the upper South Alligator River, Australia

    Energy Technology Data Exchange (ETDEWEB)

    Ryan, Bruce [Environmental Research Institute of the Supervising Scientist (eriss), GPO Box 461, Darwin NT 0801 (Australia)], E-mail: bruce.ryan@environment.gov.au; Bollhoefer, Andreas [Environmental Research Institute of the Supervising Scientist (eriss), GPO Box 461, Darwin NT 0801 (Australia); Martin, Paul [Environmental Research Institute of the Supervising Scientist (eriss), GPO Box 461, Darwin NT 0801 (Australia); Agency' s Laboratories, Seibersdorf, IAEA, A-1400 Vienna (Austria)

    2008-03-15

    During an inspection of the old Rockhole Mine area in Kakadu National Park in 1999, it was found that a small amount of tailings from the former South Alligator uranium (U) mill had been uncovered by wet season rain and road works. Samples of sediment, water and freshwater mussels, Velesunio angasi, were collected from the South Alligator River, near and at the confluence of Rockhole Mine Creek, and adjacent to the exposed tailings. The {sup 228}Ra/{sup 226}Ra activity ratios in sediments and mussel tissue indicate a small influence from the tailings and from Rockhole Mine adit water on {sup 226}Ra concentrations. The uptake of {sup 226}Ra in mussels does not correlate with other alkaline-earth metals. Mussel U concentrations are higher immediately downstream of Rockhole Mine Creek, but there is no noticeable increase in the immediate vicinity of the tailings area. A hypothetical ingestion of 2 kg of mussels from the sites was used to estimate the committed effective dose for a 10-year-old child resulting in a figure of 0.23 mSv per annum, of this total dose, 69% is attributed to {sup 210}Po. Only 0.03 mSv per annum can be directly linked to impacts of the tailings.

  19. Seasonal precipitation patterns along pathways of South American low-level jets and aerial rivers

    Science.gov (United States)

    Poveda, Germán.; Jaramillo, Liliana; Vallejo, Luisa F.

    2014-01-01

    We study the seasonal dynamics of the eastern Pacific (CHOCO) and Caribbean low-level jets (LLJ), and aerial rivers (AR) acting on tropical and subtropical South America. Using the ERA-Interim reanalysis (1979-2012), we show that the convergence of both LLJs over the eastern Pacific-western Colombia contributes to the explanation of the region's world-record rainfall. Diverse variables involved in the transport and storage of moisture permit the identification of an AR over northern South America involving a midtropospheric easterly jet that connects the Atlantic and Pacific Oceans across the Andes, with stronger activity in April to August. Other major seasonal AR pathways constitute part of a large gyre originating over the tropical North Atlantic, veering to the southeast over the eastern Andes and reaching regions of northern Argentina and southeastern Brazil. We illustrate the distribution of average seasonal precipitation along the LLJs and AR pathways with data from the Tropical Rainfall Measuring Mission (1998-2011), combined with considerations of CAPE, topography, and land cover. In addition, the theory of the biotic pump of atmospheric moisture (BiPAM) is tested at seasonal time scales, and found to hold in 8 out of 12 ARs, and 22 out of 32 forest-covered tracks (64% in distance) along the ARs. Deviations from BiPAM's predictions of rainfall distribution are explained by the effects of topography, orography, and land cover types different from forests. Our results lend a strong observational support to the BiPAM theory at seasonal time scales over South American forested flat lands.

  20. South Fork Salmon River Watershed Restoration, 2008-2009 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Reaney, Mark D. [Nez Perce Tribe Department of Fisheries Resource Management

    2009-04-15

    The watershed restoration work elements within the project area, the South Fork Salmon River Watershed, follow the watershed restoration approach adopted by the Nez Perce Tribe Department of Fisheries Resource Management (DFRM) - Watershed Division. The vision of the Nez Perce Tribe DFRM-Watershed Division focuses on protecting, restoring, and enhancing watersheds and treaty resources within the ceded territory of the Nez Perce Tribe under the Treaty of 1855 with the United States Federal Government. The program uses a holistic approach, which encompasses entire watersheds, ridge top to ridge top, emphasizing all cultural aspects and strategies that rely on natural fish production and healthy river ecosystems. The Nez Perce Tribe DFRM-Watershed Division strives towards maximizing historic ecosystem productivity and health for the restoration of anadromous and resident fish populations and the habitat on which all depend on for future generations Originally, this project was funded to create a step/pool stream channel that was appropriate to restore fish passage where the 'Glory Hole Cascade' is currently located at the Stibnite Mine. Due to unforeseen circumstances at the time, the project is unable to move forward as planned and a request for a change in scope of the project and an expansion of the geographic area in which to complete project work was submitted. No additional funds were being requested. The ultimate goal of this project is to work with the holistic, ridge top to ridge top approach to protect and restore the ecological and biological functions of the South Fork Salmon River Watershed to assist in the recovery of threatened and endangered anadromous and resident fish species. FY 2008 Work Elements included two aquatic organism passage (AOP) projects to restore habitat connectivity to two fish-bearing tributaries to the East Fork South Fork Salmon River, Salt and Profile Creeks. The Work Elements also included road survey and assessment

  1. Long-Term Changes in the Water Quality and Macroinvertebrate Communities of a Subtropical River in South China

    Directory of Open Access Journals (Sweden)

    Kun Li

    2014-12-01

    Full Text Available Subtropical rivers support a highly diverse array of benthic macroinvertebrates. In this study, by combining historical data and new data, we identified specific changes in the Guanlan River, in South China, from 1981 to 2011, and evaluated the effectiveness of an ecological restoration project under highly polluted conditions. From 1981 to 2011, the water quality in the Guanlan River underwent three major stages. With the deterioration of water quality, there was an overall decrease in the species number of macroinvertebrates in the Guanlan River, an increase in macroinvertebrate density, and a reduction of the biodiversity, and a reduction of functional feeding groups. In 2011, after five years of comprehensive remediation, the Guanlan River was somewhat improved. Macroinvertebrate biodiversity in the middle reach of the Guanlan River, where a key ecological restoration engineering project was implemented, did not differ significantly from other sites. This finding indicates that the effectiveness of ecological restoration measures in highly polluted rivers, particularly at the reach-scale, is very limited and even ineffective.

  2. Antibiogram, Adhesive Characteristics, and Incidence of Class 1 Integron in Aeromonas Species Isolated from Two South African Rivers

    Directory of Open Access Journals (Sweden)

    Isoken H. Igbinosa

    2013-01-01

    Full Text Available Aeromonas species are well distributed in freshwater environments, and their natural susceptibility to antimicrobials renders them interesting candidates for the survey of antimicrobial resistance in freshwater milieu. Water samples were collected from Kat and Tyume rivers in the Eastern Cape province of South Africa, and a total of 45 isolates identified as Aeromonas species were recovered from the two rivers. All Aeromonas isolates were resistant to oxacillin, penicillin, clindamycin, cephalothin, vancomycin, and rifamycin, while appreciable susceptibilities (89.3 : 94.1%, 82.1 : 94.1%, 85.7 : 88.2%, and 92.9 : 88.2% were observed against ciprofloxacin, chloramphenicol, nitrofurantoin, and gentamicin from Kat and Tyume rivers, respectively. Multiple antibiotic resistance (MAR indices ranged from 0.016 to 0.044 for the two rivers. Class 1 integron was detected in about 20% of the isolates, and all the isolates except one showed ability to produce biofilm in vitro as weak producers (53.33%, moderate producers (15.56%, and strong producers (28.9%. This investigation provides a baseline data on antibiotic resistance as well as the adhesive characteristics of Aeromonas isolates from Tyume and Kat rivers in the Eastern Cape province of South Africa.

  3. Antibiogram, adhesive characteristics, and incidence of class 1 integron in Aeromonas species isolated from two South African rivers.

    Science.gov (United States)

    Igbinosa, Isoken H; Chigor, Vincent N; Igbinosa, Etinosa O; Obi, Lawrence C; Okoh, Anthony I

    2013-01-01

    Aeromonas species are well distributed in freshwater environments, and their natural susceptibility to antimicrobials renders them interesting candidates for the survey of antimicrobial resistance in freshwater milieu. Water samples were collected from Kat and Tyume rivers in the Eastern Cape province of South Africa, and a total of 45 isolates identified as Aeromonas species were recovered from the two rivers. All Aeromonas isolates were resistant to oxacillin, penicillin, clindamycin, cephalothin, vancomycin, and rifamycin, while appreciable susceptibilities (89.3 : 94.1%, 82.1 : 94.1%, 85.7 : 88.2%, and 92.9 : 88.2%) were observed against ciprofloxacin, chloramphenicol, nitrofurantoin, and gentamicin from Kat and Tyume rivers, respectively. Multiple antibiotic resistance (MAR) indices ranged from 0.016 to 0.044 for the two rivers. Class 1 integron was detected in about 20% of the isolates, and all the isolates except one showed ability to produce biofilm in vitro as weak producers (53.33%), moderate producers (15.56%), and strong producers (28.9%). This investigation provides a baseline data on antibiotic resistance as well as the adhesive characteristics of Aeromonas isolates from Tyume and Kat rivers in the Eastern Cape province of South Africa.

  4. Occurrence and behavior of pharmaceuticals, steroid hormones, and endocrine-disrupting personal care products in wastewater and the recipient river water of the Pearl River Delta, South China.

    Science.gov (United States)

    Yu, Yiyi; Huang, Qiuxin; Wang, Zhifang; Zhang, Kun; Tang, Caiming; Cui, Jianlan; Feng, Jialiang; Peng, Xianzhi

    2011-04-01

    The occurrence and behavior of β-blockers, antiepileptic drug carbamazepine and its metabolites, X-ray contrast agent iopromide, natural and synthetic hormones, and several groups of hormone-like personal care products (PCPs), including antiseptics (triclocarban, triclosan, and 2-phenylphenol), parabens and bisphenol A, were investigated in municipal wastewater, sewage sludge, and urban river water of the Pearl River Delta, South China. The pharmaceuticals, natural hormones and PCPs were ubiquitously detected in the raw wastewater from a sewage treatment plant (STP). Only triclocarban and triclosan were detected at significant amounts in the dewatered sludge. Iopromide and the PCPs were greatly removed/transformed from the aqueous phase of the wastewater. The β-blockers were only moderately removed/transformed. Carbamazepine passed through the STP almost unchanged. Biodegradation was the dominant process for elimination/transformation of the pharmaceuticals, hormones, and most PCPs in the STP. However, sorption also played an important role in the fate of triclocarban with nearly 50% of the mass load entering the STP ended up and persisted in the dewatered sludge. The pharmaceuticals, estrone, and PCPs were also widely detected in the Pearl River at Guangzhou. Bisphenol A had the highest concentration. The pharmaceutical concentrations in the Pearl River were higher in March than in May, most likely due to less dilution by lower precipitation. The omnipresence and high levels of the pharmaceuticals and PCPs in the Pearl River may be associated with direct discharge of untreated wastewater and pose potential risks to the ecological system.

  5. Influence of the South-to-North Water Transfer and the Yangtze River mitigation projects on the water quality of Han River in China

    Science.gov (United States)

    Kuo, Yi-Ming; liu, Wenwen

    2016-04-01

    Algal bloom was occurred every year in the down stream of the Han River in recent five years. The operation of the Middle Route of China's South-to-North Water Transfer (MSNW) Project may affect the hydrological condition and self-purification of water body in the down and middle streams of the Han River, trigger algal bloom, and elevate the difficulty in the treatment of water pollutants, which is a crucial issue involved in ecology, environment, and economy. In this study, the monthly water samples were collected from the middle and down streams of Han River from July 2014 to December 2015. Factor Analysis and Cluster Analysis were applied to identify major pollution types and areas and determine the reasons influencing the variations of water quality in the down and middle streams of the Han River. The results show that whole monitoring period can be divided into three periods as different pollution levels. The factor analysis distinguishes three pollution types (inorganic pollution, organic pollution, and agricultural pollution) and thier contributions on Han River water quality in dry and wet seasons. Industrial areas are influenced by inorganic pollution and cultivated lands are influenced by agricultural pollution. The water quality in wet season is significantly affected by flow rate, which was sometimes controlled by two projects. The heavy polluted water may be diluted by high flow volume.

  6. An evaluation of the effect of future climate on runoff in the Dongjiang River basin, South China

    OpenAIRE

    K. Lin; Zhai, W; Huang, S.; Liu, Z.

    2015-01-01

    The impact of future climate change on the runoff for the Dongjiang River basin, South China, has been investigated with the Soil and Water Assessment Tool (SWAT). First, the SWAT model was applied in the three sub-basins of the Dongjiang River basin, and calibrated for the period of 1970–1975, and validated for the period of 1976–1985. Then the hydrological response under climate change and land use scenario in the next 40 years (2011–2050) was studied. The future weather data was generated ...

  7. Water resources in the Big Lost River Basin, south-central Idaho

    Science.gov (United States)

    Crosthwaite, E.G.; Thomas, C.A.; Dyer, K.L.

    1970-01-01

    The Big Lost River basin occupies about 1,400 square miles in south-central Idaho and drains to the Snake River Plain. The economy in the area is based on irrigation agriculture and stockraising. The basin is underlain by a diverse-assemblage of rocks which range, in age from Precambrian to Holocene. The assemblage is divided into five groups on the basis of their hydrologic characteristics. Carbonate rocks, noncarbonate rocks, cemented alluvial deposits, unconsolidated alluvial deposits, and basalt. The principal aquifer is unconsolidated alluvial fill that is several thousand feet thick in the main valley. The carbonate rocks are the major bedrock aquifer. They absorb a significant amount of precipitation and, in places, are very permeable as evidenced by large springs discharging from or near exposures of carbonate rocks. Only the alluvium, carbonate rock and locally the basalt yield significant amounts of water. A total of about 67,000 acres is irrigated with water diverted from the Big Lost River. The annual flow of the river is highly variable and water-supply deficiencies are common. About 1 out of every 2 years is considered a drought year. In the period 1955-68, about 175 irrigation wells were drilled to provide a supplemental water supply to land irrigated from the canal system and to irrigate an additional 8,500 acres of new land. Average. annual precipitation ranged from 8 inches on the valley floor to about 50 inches at some higher elevations during the base period 1944-68. The estimated water yield of the Big Lost River basin averaged 650 cfs (cubic feet per second) for the base period. Of this amount, 150 cfs was transpired by crops, 75 cfs left the basin as streamflow, and 425 cfs left as ground-water flow. A map of precipitation and estimated values of evapotranspiration were used to construct a water-yield map. A distinctive feature of the Big Lost River basin, is the large interchange of water from surface streams into the ground and from the

  8. Acid mine-water and agriculture pollution in a river skirting the Donana National Park (Guadiamar River, South West Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Cabrera, F.; Toca, C.G.; Diaz, E.; De Arambarri, P.

    1984-01-01

    The Agrio river receives the drainage waters from Aznalcollar opencast-worked polymetallic sulfide deposits and the old mine spoil heaps. Some 7 km downstream, the Agrio river joins the Guadiamar river, which is the last tributary on the right of the Guadalquivir river. Drainage waters from the mine and old spoil heaps are the source of high concentrations of heavy metals in the water and sediments of the Agrio and Guadiamar rivers. When river flows increase because of heavy rains or reservoir discharges, sediments are resuspended and transported downstream. The presence of other effluents rich in organic matter with active chelating agents facilitates the dissolution and transport of the metals. Consequently, 30 km downstream from the mine heavy metal concentrations in Guadiamar river are still higher than those in other unpolluted rivers of this zone. Pollution by olive mill effluents (alpechines) is important during the grinding season, causing increases in the K, P and organic matter, and decreases in dissolved oxygen. Nitrogen and P fertilization of rice fields at present does not produce abnormal increases in the concentration of these elements in the water. Concentrations of herbicides in rice field canals and Donana National Park waters reach values considered as the limit of safety for aquatic life. 37 references, 8 figures, 7 tables.

  9. Anaerobic oxidation of methane in coastal sediment from Guishan Island (Pearl River Estuary), South China Sea

    Indian Academy of Sciences (India)

    Zijun Wu; Huaiyang Zhou; Xiaotong Peng; Nan Jia; Yuhong Wang; Linxi Yuan

    2008-12-01

    The concentrations of CH4, SO$^{2−}_{4}$, CO2 and the carbon isotope compositions of CO2 and CH4 in the pore-water of the GS sedimentary core collected from Guishan Island (Pearl River Estuary), South China Sea,were determined. The methane concentration in the pore-water shows dramatic changes and sulfate concentration gradients are linear at the base of the sulfate reduction zone for the station. The carbon isotope of methane becomes heavier at the sulfate-methane transition (SMT)likely because of the Raleigh distillation effect; 12CH4 was oxidized faster than 13CH4 and this caused the enrichment of residual methane 13C and 13C- CO2 minimum. The geochemical profiles of the pore-water support the existence of anaerobic oxidation of methane (AOM), which is mainly controlled by the quality and quantity of the sedimentary organic matter. As inferred from the index of 13C-TOC value and TOC/TN ratio, the organic matter is a mix of mainly refractory terrestrial component plus some labile alga marine-derived in the study area. A large amount of labile organic matter (mainly labile alga marine-derived) is consumed via the process of sedimentary organic matter diagenesis, and this reduces the amount of labile organic matter incorporated into the base of the sulfate reduction zone. Due to the scarcity of labile organic matter, the sulfate will in turn be consumed by its reaction with methane and therefore AOM takes place.Based on a diffussion model, the portion of pore-water sulfate reduction via AOM is 58.6%,and the percentage of CO2 in the pore-water derived from AOM is 41.4%. Thus, AOM plays an important role in the carbon and sulfur cycling in the marine sediments of Pearl River Estuary.

  10. Temporal Variations in Physico-Chemical and Microbiological Characteristics of Mvudi River, South Africa

    Directory of Open Access Journals (Sweden)

    Joshua N. Edokpayi

    2015-04-01

    Full Text Available Surface water has been a source of domestic water due to shortage of potable water in most rural areas. This study was carried out to evaluate the level of contamination of Mvudi River in South Africa by measuring turbidity, electrical conductivity (EC, pH, concentrations of nitrate, fluoride, chloride, and sulphate. E. coli and Enterococci were analysed using membrane filtration technique. Average pH, EC and Turbidity values were in the range of 7.2–7.7, 10.5–16.1 mS/m and 1.3–437.5 NTU, respectively. The mean concentrations of fluoride, chloride, nitrate and sulphate for both the wet and the dry seasons were 0.11 mg/L and 0.27 mg/L, 9.35 mg/L and 14.82 mg/L, 3.25 mg/L and 6.87 mg/L, 3.24 mg/L and 0.70 mg/L, respectively. E. coli and Enterococci counts for both the wet and the dry seasons were 4.81 × 103 (log = 3.68 and 5.22 × 103 (log = 3.72, 3.4 × 103 (log = 3.53 and 1.22 × 103 (log = 3.09, per 100 mL of water, respectively. The count of E. coli for both seasons did not vary significantly (p > 0.05 but Enterococci count varied significantly (p < 0.001. All the physico-chemical parameters obtained were within the recommended guidelines of the Department of Water Affairs and Forestry of South Africa and the World Health Organization for domestic and recreational water use for both seasons except turbidity and nitrates. The microbiological parameters exceeded the established guidelines. Mvudi River is contaminated with faecal organisms and should not be used for domestic purposes without proper treatment so as to mitigate the threat it poses to public health.

  11. Environmental settings of the South Fork Iowa River basin, Iowa, and the Bogue Phalia basin, Mississippi, 2006-10

    Science.gov (United States)

    McCarthy, Kathleen A.; Rose, Claire E.; Kalkhoff, Stephen J.

    2012-01-01

    Studies of the transport and fate of agricultural chemicals in different environmental settings were conducted by the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) Program's Agricultural Chemicals Team (ACT) at seven sites across the Nation, including the South Fork Iowa River basin in central Iowa and the Bogue Phalia basin in northwestern Mississippi. The South Fork Iowa River basin is representative of midwestern agriculture, where corn and soybeans are the predominant crops and a large percentage of the cultivated land is underlain by artificial drainage. The Bogue Phalia basin is representative of corn, soybean, cotton, and rice cropping in the humid, subtropical southeastern United States. Details of the environmental settings of these basins and the data-collection activities conducted by the USGS ACT over the 2006-10 study period are described in this report.

  12. Study on the quality of ground, spring and river waters in south-east Serbia

    Directory of Open Access Journals (Sweden)

    Stojanović Zorica S.

    2015-01-01

    Full Text Available The study deals with mineral characterization of natural waters from South-East Serbia. The contents of aluminium, arsenic, calcium, cadmium, cobalt, chromium, cooper, iron, potassium, magnesium, manganese, sodium, nickel, lead and zinc were analysed in spring, ground and river waters by inductively coupled plasma-atomic emission spectrometry (ICP-AES technique. The study area was in the Southern Serbia, and included slopes of Rtanj, Ozren, Bukovik, Vrdenik and Čemernik mountains, and the valley of South Morava. Obtained contents were compared with Serbian regulations on the quality of water for human use, and directive of World Health Organization (WHO for maximum allowed concentrations of chemical substances. High contents of macro-elements, namely calcium, magnesium and potassium, were detected in several spring and ground water samples which are believed to be due to direct influence of rock minerals. Some water samples contained iron, manganese and copper in concentration up to 84.2 μg dm-3, 8.10 μg dm-3 and 14.9 μg dm-3, respectively, but within the permissible limits. Other heavy metals were not detected in analysed samples. Based on the derived results, tested ground and spring water samples have significant potential to be used as sources for the production of bottled water, but further investigations are necessary. Additional investigations have to be focused on complete physical, chemical and microbiological assessments of water resources. Systematic hydrogeological assessment also should be performed in all seasons. In the meantime, precautionary measures should be immediately taken to protect and preserve these water resources. [Projekat Ministarstva nauke Republike Srbije, br. TR 31014

  13. Hydrological impact of rainwater harvesting in the Modder river basin of central South Africa

    Directory of Open Access Journals (Sweden)

    W. A. Welderufael

    2011-05-01

    Full Text Available Along the path of water flowing in a river basin are many water-related human interventions that modify the natural systems. Rainwater harvesting is one such intervention that involves harnessing of water in the upstream catchment. Increased water usage at upstream level is an issue of concern for downstream water availability to sustain ecosystem services. The upstream Modder River basin, located in a semi arid region in the central South Africa, is experiencing intermittent meteorological droughts causing water shortages for agriculture, livestock and domestic purpose. To address this problem a technique was developed for small scale farmers with the objective of harnessing rainwater for crop production. However, the hydrological impact of a wider adoption of this technique by farmers has not been well quantified. In this regard, the SWAT hydrological model was used to simulate the hydrological impact of such practices. The scenarios studied were: (1 Baseline scenario, based on the actual land use of 2000, which is dominated by pasture (combination of natural and some improved grass lands (PAST; (2 Partial conversion of Land use 2000 (PAST to conventional agriculture (Agri-CON; and (3 Partial conversion of Land use 2000 (PAST to in-field rainwater harvesting which was aimed at improving the precipitation use efficiency (Agri-IRWH.

    SWAT was calibrated using observed daily mean stream flow data of a sub-catchment (419 km2 in the study area. SWAT performed well in simulating the stream flow giving Nash and Sutcliffe (1970 efficiency index of 0.57 for the monthly stream flow calibration. The simulated water balance results showed that the highest peak mean monthly direct flow was obtained on Agri-CON land use (18 mm, followed by PAST (12 mm and Agri-IRWH land use (9 mm. These were 19 %, 13 % and 11 % of the mean annual rainfall, respectively. The Agri-IRWH scenario reduced direct flow by 38 % compared to Agri-CON. On the other

  14. Mercury contamination history of an estuarine floodplain reconstructed from a 210Pb-dated sediment core (Berg River, South Africa).

    Science.gov (United States)

    Kading, T J; Mason, R P; Leaner, J J

    2009-01-01

    Mercury deposition histories have been scarcely documented in the southern hemisphere. A sediment core was collected from the ecologically important estuarine floodplain of the Berg River (South Africa). We establish the concentration of Hg in this (210)Pb-dated sediment core at mercury deposition to the site and reveals the onset of enhanced mercury deposition in 1970. The ratio of methylmercury to total mercury is relatively high in these sediments when compared to other wetlands.

  15. Comparison of two methods for estimating base flow in selected reaches of the South Platte River, Colorado

    Science.gov (United States)

    Capesius, Joseph P.; Arnold, L. Rick

    2012-01-01

    The U.S. Geological Survey, in cooperation with the Colorado Water Conservation Board, compared two methods for estimating base flow in three reaches of the South Platte River between Denver and Kersey, Colorado. The two methods compared in this study are the Mass Balance and the Pilot Point methods. Base-flow estimates made with the two methods were based upon a 54-year period of record (1950 to 2003).

  16. Platinum group elements in stream sediments of mining zones: The Hex River (Bushveld Igneous Complex, South Africa)

    Science.gov (United States)

    Almécija, Clara; Cobelo-García, Antonio; Wepener, Victor; Prego, Ricardo

    2017-05-01

    Assessment of the environmental impact of platinum group elements (PGE) and other trace elements from mining activities is essential to prevent potential environmental risks. This study evaluates the concentrations of PGE in stream sediments of the Hex River, which drains the mining area of the Bushveld Igneous Complex (South Africa), at four sampling points. Major, minor and trace elements (Fe, Ca, Al, Mg, Mn, V, Cr, Zn, Cu, As, Co, Ni, Cd, and Pb) were analyzed by FAAS and ETAAS in suspended particulate matter and different sediment fractions (rocks. The highest concentrations were observed closer to the mining area, decreasing with distance and in the cycle, increasing the presence of PGE in the fine fraction of river sediments. We propose that indicators such as airborne particulate matter, and soil and river sediment quality, should be added to the protocols for evaluating the sustainability of mining activities.

  17. DEVELOPMENT OF A SMALLMOUTH BASS QUANTITATIVE REAL-TIME PCR ASSAY TO MEASURE VTG GENE INDUCTION IN MALE FISH FROM THE SOUTH BRANCH OF THE POTOMAC RIVER

    Science.gov (United States)

    A high incidence of intersex bass, primarily male smallmouth bass with previtellogenic oocytes, exists in the south branch of the Potomac River. Exposures to endocrine disrupting chemicals (EDCs) may be the cause of these abnormalities. Potential sources of EDCs to the river are ...

  18. The distribution of dimethylcarbazoles in oils from the Pearl River Mouth Basin, South China Sea

    Institute of Scientific and Technical Information of China (English)

    ZHANG Chunming; ZHAO Hongjing; GAO Kunshun; YANG Shaokun

    2007-01-01

    C2-carbazole isomers have been investigated in crude oils from the Hui-Liu Structure Ridge (HLSR) in the Pearl River Mouth Basin (PRMB), South China Sea. The NH shielded isomer, as well as the NH partially shielded isomers, was detected in high abundance and the NH exposed isomers in lower abundance. A small-enrichment trend of 1,8-dimethylcarbazole (DMC) was observed in crude oils along the western part of HLSR (WPHLSR), which may indicate little effect of migration on the C2-carbazole distributions. Two strikingly different distribution patterns of NH partially shielded isomers were observed in the reservoirs along the WPHLSR: one with a preference of 1,3- and 1,6-DMCs and the other with a preference of 1,4- and 1,5-DMCs. All of the oils occurring in the Upper reservoirs have a preference of 1,3- and 1,6-DMCs, whereas those trapped in the Lower reservoirs show a preference of 1,4- and 1,5-DMCs, which may indicate there are two petroleum migration systems in the WPHLSR.

  19. Conservation of fishes in the Elands River, Mpumalanga, South Africa: Past, present and future

    Directory of Open Access Journals (Sweden)

    Gordon C. O’Brien

    2014-02-01

    Full Text Available In an isolated reach, between two large natural waterfalls in the Elands River in Mpumalanga, populations of a critically endangered Kneria sp., the endangered Chiloglanis bifurcus and a genetically unique population of Labeobarbus polylepis occur. The aim of this article was to evaluate past efforts to conserve these fishes, describe the current status and propose future conservation and management actions. The population status assessments were based on a series of fish community composition and population structure evaluations from surveys undertaken at 22 sites during seven surveys from 2002 to 2006. Although water-use activities have continued to increase in the area, impacts have been offset by conservation efforts initiated almost 30 years ago. The existing C. bifurcus population appears to be stable, which is reflected in the downgrading of the conservation status of the species from critically endangered to endangered. The abundance of the kneriid population appears to be increasing and spreading to other tributaries in the study area. The abundance of L. polylepis appears to be increasing but has still not reached historical levels.Conservation implications: Continued conservation efforts are required to protect these fishes. This case study presented a rare example of how the impacts associated with the use of aquatic resources in South Africa can successfully be offset by conservation efforts.

  20. Influence of climate factors on Vibrio cholerae dynamics in the Pearl River estuary, South China.

    Science.gov (United States)

    Yue, Yujuan; Gong, Jianhua; Wang, Duochun; Kan, Biao; Li, Baisheng; Ke, Changwen

    2014-06-01

    Current research has seldom focused on the quantitative relationships between Vibrio cholerae (V. cholerae) and climate factors owing to the complexities and high cost of field observation in the aquatic environment. This study has focused on the relationships between V. cholerae and climate factors based on linear regression method and data partition method. Data gathered from 2008 to 2009 in the Pearl River estuary, South China, were adopted. Positive rate of V. cholerae was correlated closely with monthly climate factors of water temperature and air temperature, respectively in 2009. Quarterly data analysis from 2008 to 2009 showed that there existed seasonal characteristic for V. cholerae. Positive rate of V. cholerae was correlated positively with quarterly climate factors of land surface temperature, pH, water temperature, air temperature and rainfall, respectively and negatively with quarterly air pressure. Partition data analysis in 2009 showed that there existed geography region characteristic for V. cholerae. V. cholerae dynamics was closely correlated to climate factors in the downstream area. However, it was more greatly affected by human geography factors in the urban area. Positive annual rate of V. cholerae was higher in the downstream area than in the urban area both in 2008 and 2009. At last, a cellular automaton model was used to simulate V. cholerae diffusion downstream, and the distribution of V. cholerae obtained from this model was similar to that obtained from the field observations.

  1. Groundwater modeling of the proposed new production reactor site, Savannah River Site, South Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Looney, B.B.; Haselow, J.S.; Andersen, P.F.; Spalding, C.P.; Davis, D.H.

    1990-01-05

    This report addresses groundwater modeling performed to support the Environmental Impact Statement (EIS) that is being prepared by the Department of Energy (DOE). The EIS pertains to construction and operation of a new production reactor (NPR) that is under consideration for the Savannah River Site (SRS). Three primary issues are addressed by the modeling analysis: (1) groundwater availability, (2) changes in vertical hydraulic gradients as a result of groundwater pumpage, and (3) migration of potential contaminants from the NPR site. The modeling indicates that the maximum pumpage to be used, 1000 gpm, will induce only minor drawdown across SRS. Pumpage of this magnitude will have a limited effect on the upward gradient from the Cretaceous into the Tertiary near Upper Three Runs Creek. Potentiometric surface maps generated from modeled results indicate that horizontal flow in the water table is either towards Four Mile Creek to the north or to Pen Branch on the south. Particle tracking analysis indicates that the primary flow paths are vertical into the Lower Tertiary Zone, with very little lateral migration. Total travel times from the NPR site to the edge of the model (approximately 3 miles) is on the order of 50 years. The flow direction of water in the Lower Tertiary Zone is relatively well defined due to the regional extent of the flow system. The Pen Branch Fault does not influence contaminant migration for this particular site because it is in the opposite direction of Lower Tertiary Zone groundwater flow. 20 refs., 27 figs., 2 tabs.

  2. Estimation of underground river water availability based on rainfall in the Maros karst region, South Sulawesi

    Science.gov (United States)

    Arsyad, Muhammad; Ihsan, Nasrul; Tiwow, Vistarani Arini

    2016-02-01

    Maros karst region, covering an area of 43.750 hectares, has water resources that determine the life around it. Water resources in Maros karst are in the rock layers or river underground in the cave. The data used in this study are primary and secondary data. Primary data includes characteristics of the medium. Secondary data is rainfall data from BMKG, water discharge data from the PSDA, South Sulawesi province in 1990-2010, and the other characteristics data Maros karst, namely cave, flora and fauna of the Bantimurung Bulusaraung National Park. Data analysis was conducted using laboratory test for medium characteristics Maros karst, rainfall and water discharge were analyzed using Minitab Program 1.5 to determine their profile. The average rainfall above 200 mm per year occurs in the range of 1999 to 2005. The availability of the water discharge at over 50 m3/s was happened in 1993 and 1995. Prediction was done by modeling Autoregressive Integrated Moving Average (ARIMA), with the rainfall data shows that the average precipitation for four years (2011-2014) will sharply fluctuate. The prediction of water discharge in Maros karst region was done for the period from January to August in 2011, including the type of 0. In 2012, the addition of the water discharge started up in early 2014.

  3. Microcrustaceans (Branchipoda and Copepoda) of Wetland Impoundments on the Savannah River Site, Aiken, South Carolina

    Energy Technology Data Exchange (ETDEWEB)

    DeBiase, Adrienne E; Taylor, Barbara E

    2005-09-21

    The United States Department of Energy’s Savannah River Site (SRS) in Aiken, Allendale, and Barnwell Counties, South Carolina, contains an abundance of freshwater wetlands and impoundments. Four large impoundments, as well as several small, abandoned farm and mill ponds, and about 400 Carolina bays and other small, isolated depression wetland ponds are located within the 893 km2 area of the SRS. Crustaceans of the orders Branchiopoda and Copepoda are nearly ubiquitous in these water bodies. Although small in size, these organisms are often very abundant. They consequently play an important trophic role in freshwater food webs supporting fish, larval salamanders, larval insects, and numerous other animals, aquatic and terrestrial. This report provides an introduction to the free-living microcrustaceans of lentic water bodies on the SRS and a comprehensive list of species known to occur there. Occurrence patterns are summarized from three extensive survey studies, supplemented with other published and unpublished records. In lieu of a key, we provide a guide to taxonomic resources and notes on undescribed species. Taxa covered include the orders Cladocera, Anostraca, Laevicaudata, and Spinicaudata of the Subclass Branchiopoda and the Superorders Calanoida and Cyclopoida of Subclass Copepoda. Microcrustaceans of the Superorder Harpacticoida of the Subclass Copepoda and Subclass Ostracoda are also often present in lentic water bodies. They are excluded from this report because they have not received much study at the species level on the SRS.

  4. Variation in Bachman's Sparrow home-range size at the Savannah River Site, South Carolina

    Science.gov (United States)

    Stober, J.M.; Krementz, D.G.

    2006-01-01

    Using radiotelemetry, we studied variation in home-range size of the Bachman's Sparrow (Aimophila aestivalis) at the Savannah River Site (SRS), South Carolina, during the 1995 breeding season. At SRS, sparrows occurred primarily in two habitats: mature pine habitats managed for Red-cockaded Woodpecker (Picoides borealis) and pine plantations 1 to 6 years of age. The mean 95% minimum convex polygon home-range size for males and females combined (n = 14) was 2.95 ha + 0.57 SE, across all habitats. Mean homerange size for males in mature pine stands (4.79 ha + 0.27, n = 4) was significantly larger than that in 4-year-old (3.00 ha + 0.31, n = 3) and 2-year-old stands (1.46 ha + 0.31, it = 3). Home-range sizes of paired males and females (it = 4 pairs) were similar within habitat type; mean distances between consecutive locations differed by habitat type and sex. We hypothesize that a gradient in food resources drives home-range dynamics.

  5. Classification of hydrostratigraphic units at the Savannah River Site, South Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Aadland, R.K.; Bledsoe, H.W.

    1990-12-01

    A detailed synthesis of the hydrologic, geophysical and core data from wells penetrating the updip Mesozoic-Cenozoic Coastal Plain sequence at and near the Savannah River Site (SRS) was conducted to define and classify the hydrostratigraphic units. The purpose of the study was to give the SRS a single unified hydrostratigraphic classification that defines and addresses the hydrogeologic characteristics of the aquifers underlying the site. The characterization, areal distribution and classification of the aquifer and aquifer systems gives SRS the tools to evaluate ground water movement and contaminant transport in a comprehensive regional context. An alpha-numeric nomenclature has been temporarily adopted in this report for classifying the aquifers and aquifer systems at SRS. Formal geographic names for the aquifers and aquifer systems will be proposed in the near future but must be agreed upon and ratified by the South Carolina Hydrostratigraphic Subcommittee which was in part organized for the purpose. The classification utilizes a hierarchy of terms ranked at three levels: Aquifer Systems that transmit ground water regionally; Aquifer Units which are mappable units > 400 square miles in area; and Aquifer Zones that differentiate aquifers internally on the basis of locally significant characteristics.

  6. Estimation of streamflow gains and losses in the lower San Antonio River watershed, south-central Texas, 2006-10

    Science.gov (United States)

    Lizarraga, Joy S.; Wehmeyer, Loren L.

    2012-01-01

    The U.S. Geological Survey (USGS), in cooperation with the San Antonio River Authority, the Evergreen Underground Water Conservation District, and the Goliad County Groundwater Conservation District, investigated streamflow gains and losses during 2006-10 in the lower San Antonio River watershed in south-central Texas. Streamflow gains and losses were estimated using 2006-10 continuous streamflow records from 11 continuous streamflow-gaging stations, and discrete streamflow measurements made at as many as 20 locations on the San Antonio River and selected tributaries during four synoptic surveys during 2006-7. From the continuous streamflow records, the greatest streamflow gain on the lower San Antonio River occurred in the reach from Falls City, Tex., to Goliad, Tex. The greatest streamflow gain on Cibolo Creek during 2006-10 occurred in the reach from near Saint Hedwig, Tex., to Sutherland Springs, Tex. The San Antonio River between Floresville, Tex., and Falls City was the only reach that had an estimated streamflow loss during 2006-10. During all four synoptic streamflow measurement surveys, the only substantially flowing tributary reach to the main stem of the lower San Antonio River was Cibolo Creek. Along the main stem of the lower San Antonio River, verifiable gains larger than the potential measurement error were estimated in two of the four synoptic streamflow measurement surveys. These gaining reaches occurred in the two most downstream reaches of the San Antonio River between Goliad and Farm Road (FM) 2506 near Fannin, Tex., and between FM 2506 near Fannin to near McFaddin. There were verifiable gains in streamflow in Cibolo Creek, between La Vernia, Tex., and the town of Sutherland Springs during all four surveys, estimated at between 4.8 and 14 ft3/s.

  7. Timescales, mechanisms, and controls of incisional avulsions in floodplain wetlands: Insights from the Tshwane River, semiarid South Africa

    Science.gov (United States)

    Larkin, Zacchary T.; Tooth, Stephen; Ralph, Timothy J.; Duller, Geoff A. T.; McCarthy, Terence; Keen-Zebert, Amanda; Humphries, Marc S.

    2017-04-01

    Avulsion (relocation of a river course to a new position) typically is assumed to occur more frequently in rivers with faster sedimentation rates, yet supporting field data are limited and the influence of sedimentation rate on avulsion style remains unclear. Using analysis of historical aerial photographs, optically stimulated luminescence dating of fluvial sediments, and field observations, we document three avulsions that have occurred in the last 650 years along the lower reaches of the semiarid Tshwane River in northern South Africa. Study of the modern river and abandoned reaches reveals that a downstream decrease in discharge and stream power leads to reduced channel size and declining sediment transport capacity. Bank erosion drives an increase in channel sinuosity, leading to a decline in local channel slope, and to a further decrease in discharge and sediment transport. Local sedimentation rates > 10 mm a- 1 occur within and adjacent to the channel, so over time levees and an alluvial ridge develop. The resulting increase in cross-floodplain gradient primes a reach for avulsion by promoting erosion of a new channel on the floodplain, which enlarges and extends by knickpoint retreat during periods of overbank flow. Ultimately, the new channel diverts the discharge and bedload sediment from the older, topographically higher channel, which is then abandoned. Our findings support the assumption that avulsion frequency and sedimentation rate are positively correlated, and we demonstrate that incisional avulsions can occur in settings with relatively rapid net vertical aggradation. The late Holocene avulsions on the semiarid Tshwane River have been driven by intrinsic (autogenic) processes during meander belt development, but comparison with the avulsion chronology along a river in subhumid South Africa highlights the need for additional investigations into the influence of hydroclimatic setting on the propensity for avulsion.

  8. Patterns of fish community composition along a river affected by agricultural and urban disturbance in south-central Chile

    Energy Technology Data Exchange (ETDEWEB)

    Orrego, Rodrigo [University of Ontario Institute of Technology, Oshawa, Ontario; Barra, Ricardo [University of Concepcion, Eula, Chile; Chiang, Gustavo [University of Concepcion, Eula, Chile; Adams, Marshall [ORNL; Gavilan, Juan F. [University of Concepcion, Eula, Chile

    2008-03-01

    Patterns of fish community composition in a south-central Chile river were investigated along the altitudinal-spatial and environmental gradient and as a function of anthropogenic factors. The spatial pattern of fish communities in different biocoenotic zones of the Chillan River is influenced by both natural factors such a hydrologic features, habitat, and feeding types, and also by water quality variables which can reduce the diversity and abundance of sensitive species. A principal component analysis incorporating both water quality parameters and biomarker responses of representative fish species was used to evaluate the status of fish communities along the spatial gradient of the stream. The abundance and diversity of the fish community changed from a low in the upper reaches where the low pollution-tolerant species such as salmonid dominated, to a reduced diversity in the lower reaches of the river where tolerant browser species such as cypriniformes dominated. Even though the spatial pattern of fish community structure is similar to that found for the Chilean Rivers, the structure of these communities is highly influenced by human disturbance, particularly along the lower reaches of the river.

  9. Persistent organic pollutants in the Olifants River Basin, South Africa: Bioaccumulation and trophic transfer through a subtropical aquatic food web.

    Science.gov (United States)

    Verhaert, Vera; Newmark, Nadine; D'Hollander, Wendy; Covaci, Adrian; Vlok, Wynand; Wepener, Victor; Addo-Bediako, Abraham; Jooste, Antoinette; Teuchies, Johannes; Blust, Ronny; Bervoets, Lieven

    2017-02-14

    This study investigates the trophic transfer of persistent organic pollutants (POPs: PCBs, PBDEs, OCPs and PFASs) in the subtropical aquatic ecosystem of the Olifants River Basin (South Africa) by means of trophic magnification factors (TMFs). Relative trophic levels were determined by stable isotope analysis. POP levels in surface water, sediment and biota were low. Only ∑DDTs levels in fish muscle (contaminants through the food web. TMFs were >1, indicating biomagnification of all detected POPs. Calculated TMFs for PCBs were comparable to TMF values reported from the tropical Congo River basin and lower than TMFs from temperate and arctic regions. For p,p'-DDT, a higher TMF value was observed for the subtropical Olifants River during the winter low flow season than for the tropical Congo river. TMFs of DDTs from the present study were unexpectedly higher than TMFs from temperate and arctic aquatic food webs. The fish species in the aquatic ecosystem of the Olifants River can be consumed with a low risk for POP contamination.

  10. Statistical description of wetland hydrological connectivity to the River Murray in South Australia under both natural and regulated conditions

    Science.gov (United States)

    Robinson, Sean J.; Souter, Nicholas J.; Bean, Nigel G.; Ross, Joshua V.; Thompson, Richard M.; Bjornsson, Kjartan T.

    2015-12-01

    The effect of river regulation on the connectivity of the South Australian River Murray to its floodplain wetlands was examined using unregulated 'natural' and 'regulated' river flow data simulated between the years 1895 to 2009. A sample of 185 wetlands was used to calculate a range of connectivity statistics under both simulation scenarios. These statistics summarised the timing and duration of both connection and disconnection, as well as inundated area. Wetlands ranged from being permanently inundated, connected multiple times per year due to both small fluctuations in river level and the annual flood pulse, to flooded with diminishing frequency depending on the size of the annual flood pulse and their position on the floodplain. Under the natural scenario a wide range of wetland connectivity profiles were recorded whereas under the regulated scenario wetlands tended to be either permanently inundated or infrequently flooded. Under natural conditions wetlands that required higher flow before connecting were less frequently connected and for shorter periods. Under regulated conditions a larger proportion of wetland area was permanently connected than under natural conditions, however the annual flood pulse connected a larger area of wetlands under natural conditions. The information derived from this analysis can be used to design wetland management plans for individual wetlands within a river-wide management regime restoring lost hydrological variability.

  11. Use of geochemical tracers for estimating groundwater influxes to the Big Sioux River, eastern South Dakota, USA

    Science.gov (United States)

    Neupane, Ram P.; Mehan, Sushant; Kumar, Sandeep

    2017-09-01

    Understanding the spatial distribution and variability of geochemical tracers is crucial for estimating groundwater influxes into a river and can contribute to better future water management strategies. Because of the much higher radon (222Rn) activities in groundwater compared to river water, 222Rn was used as the main tracer to estimate groundwater influxes to river discharge over a 323-km distance of the Big Sioux River, eastern South Dakota, USA; these influx estimates were compared to the estimates using Cl- concentrations. In the reaches overall, groundwater influxes using the 222Rn activity approach ranged between 0.3 and 6.4 m3/m/day (mean 1.8 m3/m/day) and the cumulative groundwater influx estimated during the study period was 3,982-146,594 m3/day (mean 40,568 m3/day), accounting for 0.2-41.9% (mean 12.5%) of the total river flow rate. The mean groundwater influx derived using the 222Rn activity approach was lower than that calculated based on Cl- concentration (35.6 m3/m/day) for most of the reaches. Based on the Cl- approach, groundwater accounted for 37.3% of the total river flow rate. The difference between the method estimates may be associated with minimal differences between groundwater and river Cl- concentrations. These assessments will provide a better understanding of estimates used for the allocation of water resources to sustain agricultural productivity in the basin. However, a more detailed sampling program is necessary for accurate influx estimation, and also to understand the influence of seasonal variation on groundwater influxes into the basin.

  12. Occurrence and behavior of non-steroidal anti-inflammatory drugs and lipid regulators in wastewater and urban river water of the Pearl River Delta, South China.

    Science.gov (United States)

    Huang, Qiuxin; Yu, Yiyi; Tang, Caiming; Zhang, Kun; Cui, Jianlan; Peng, Xianzhi

    2011-04-01

    Occurrence of five non-steroidal anti-inflammatory drugs (salicylic acid, ibuprofen, naproxen, indomethacin and diclofenac) and three lipid regulators (bezafibrate, clofibric acid and gemfibrozil) was investigated in wastewater, sewage sludge, and river water of the urban section of the Pearl River at Guangzhou in South China. Behavior and fate of the pharmaceuticals during treatment in two sewage treatment plants (STPs) were also studied in depth by determining concentrations in the influents and effluents at major treatment units and the sewage sludge. Concentrations of the pharmaceuticals in the raw wastewater were mostly at ng L(-1) levels except salicylic acid whose concentrations ranged from 9.6 to 23.3 μg L(-1). No significant amount of the pharmaceuticals was detected in the suspended particulate matter of wastewater and sewage sludge. Salicylic acid, indomethacin, and naproxen were almost completely removed (≥ 99%); gemfibrozil, ibuprofen and bezafibrate were significantly removed (>75%), whereas diclofenac and clofibric acid were removed by 60-70% during treatment in the STPs. Generally, biodegradation was the governing process for elimination of the investigated pharmaceuticals. Anaerobic biodegradation was responsible for most of the removal of diclofenac whereas aerobic biodegradation also played an important role in elimination of the other pharmaceuticals except SA, which was nearly completely removed after the anoxic process. In the Pearl River, the pharmaceuticals were widely detected. Both the concentrations and detection frequency were higher in March 2008 than those in the other seasons, which may be ascribed mainly to less dilution caused by lower precipitation. Besides the STPs, urban canals directly connected with the Pearl River may also be important contributors to the pharmaceutical contamination in the river.

  13. South Fork Tolt River Hydroelectric Project : Adopted Portions of a 1987 Federal Energy Regulatory Commission`s Final Environmental Impact Statement.

    Energy Technology Data Exchange (ETDEWEB)

    United States. Bonneville Power Administration.

    1992-07-01

    The South Fork Tolt River Hydroelectric Project that world produce 6.55 average megawatts of firm energy per year and would be sited in the Snohomish River Basin, Washington, was evaluated by the Federal Energy Regulatory commission (FERC) along with six other proposed projects for environmental effects and economic feasibility Based on its economic analysis and environmental evaluation of the project, the FERC staff found that the South Fork Tolt River Project would be economically feasible and would result in insignificant Impacts if sedimentation issues could be resolved. Upon review, the BPA is adopting portions of the 1987 FERC FEIS that concern the South Fork Tolt River Hydroelectric Project and updating specific sections in an Attachment.

  14. Potential impacts of climate change on flow regime and fish habitat in mountain rivers of the south-western Balkans.

    Science.gov (United States)

    Papadaki, Christina; Soulis, Konstantinos; Muñoz-Mas, Rafael; Martinez-Capel, Francisco; Zogaris, Stamatis; Ntoanidis, Lazaros; Dimitriou, Elias

    2016-01-01

    The climate change in the Mediterranean area is expected to have significant impacts on the aquatic ecosystems and particular in the mountain rivers and streams that often host important species such as the Salmo farioides, Karaman 1938. These impacts will most possibly affect the habitat availability for various aquatic species resulting to an essential alteration of the water requirements, either for dams or other water abstractions, in order to maintain the essential levels of ecological flow for the rivers. The main scope of this study was to assess potential climate change impacts on the hydrological patterns and typical biota for a south-western Balkan mountain river, the Acheloos. The altered flow regimes under different emission scenarios of the Intergovernmental Panel on Climate Change (IPCC) were estimated using a hydrological model and based on regional climate simulations over the study area. The Indicators of Hydrologic Alteration (IHA) methodology was then used to assess the potential streamflow alterations in the studied river due to predicted climate change conditions. A fish habitat simulation method integrating univariate habitat suitability curves and hydraulic modeling techniques were used to assess the impacts on the relationships between the aquatic biota and hydrological status utilizing a sentinel species, the West Balkan trout. The most prominent effects of the climate change scenarios depict severe flow reductions that are likely to occur especially during the summer flows, changing the duration and depressing the magnitude of the natural low flow conditions. Weighted Usable Area-flow curves indicated the limitation of suitable habitat for the native trout. Finally, this preliminary application highlighted the potential of science-based hydrological and habitat simulation approaches that are relevant to both biological quality elements (fish) and current EU Water policy to serve as efficient tools for the estimation of possible climate

  15. Concentrations, loads, and yields of nutrients and suspended sediment in the South Pacolet, North Pacolet, and Pacolet Rivers, northern South Carolina and southwestern North Carolina, October 2005 to September 2009

    Science.gov (United States)

    Journey, Celeste A.; Caldwell, Andral W.; Feaster, Toby D.; Petkewich, Mattew D.; Bradley, Paul M.

    2011-01-01

    The U.S. Geological Survey, in cooperation with Spartanburg Water, evaluated the concentrations, loads, and yields of suspended sediment, dissolved ammonia, dissolved nitrate plus nitrite, total organic nitrogen, total nitrogen, dissolved orthophosphate, dissolved phosphorus, and total phosphorus at sites in the South Pacolet, North Pacolet, and Pacolet Rivers in northern South Carolina and southwestern North Carolina from October 1, 2005, to September 30, 2009 (water years 2006 to 2009). Nutrient and sediment loads and yields also were computed for the intervening subbasin of the Pacolet River not represented by the South and North Pacolet River Basins. Except for a few outliers, the majority of the measurements of total nitrogen concentrations were well below the U.S. Environmental Protection Agency recommended guideline of 0.69 milligram per liter for streams and rivers in the nutrient ecoregion IX, which includes the study area within the Pacolet River Basin. Dissolved orthophosphate, dissolved phosphorus, and total phosphorus concentrations were significantly lower at the South Pacolet River site compared to the North Pacolet and Pacolet River sites. About 90 percent of the total phosphorus concentrations at the South Pacolet River site were below the U.S. Environmental Protection Agency recommended guideline of 0.37 milligram per liter, and more than 75 percent of the total phosphorus concentrations at the North Pacolet and Pacolet River sites were above that guideline. At all sites, minimum annual nutrient loads for the estimation period were observed during water year 2008 when severe drought conditions were present. An estimated mean annual total nitrogen load of 37,770 kilograms per year and yield of 2.63 kilograms per hectare per year were determined for the South Pacolet River site for the estimation period. The North Pacolet River site had a mean annual total nitrogen load of 65,890 kilograms per year and yield of 2.19 kilograms per hectare per year

  16. Cross-section data and pressure transducer location of the South Platte River near Fort Morgan, Colorado, 2017

    Science.gov (United States)

    Kohn, Michael S.

    2017-01-01

    The USGS Colorado Water Science Center, in cooperation with the Colorado Water Conservation Board, collected hydraulic data for the South Platte River for areas adjacent to Fort Morgan, Colo., based on the USGS streamgage 06759500 South Platte River at Fort Morgan, CO. The hydraulic data include survey point data for 54 cross sections and 10 pressure transducers, which are used to record the river stage beginning at Morgan County Road 16 and extending downstream to Morgan County Road 20.5 near Fort Morgan, Colo. The cross-section and pressure transducer location data were collected using real-time kinematic Global Navigation Satellite Systems by USGS personnel from February 15, 2017, through April 18, 2017. These data can be used to develop inundation maps, which could be available to emergency personnel, public officials, and the general public using an online public mapping application at the USGS Flood Inundation Mapper, which contains flood inundation map libraries from throughout the country created by the USGS.

  17. The Rates and Spatial Patterns of Annual Riverbank Erosion Revealed Through Terrestrial Laser Scanner Surveys of the South River, Virginia

    Science.gov (United States)

    O'Neal, M. A.; Pizzuto, J. E.

    2011-12-01

    Between 2006 and 2008 A.D., we completed annual surveys of two mercury-contaminated eroding banks, one forested and the other grass covered, along the gravel-bed, bedrock South River in Virginia. Gridded digital terrain models with a resolution of 0.05 m were created from bank topography data collected using a terrestrial laser scanner. The forested bank retreated nearly 1 m around two leaning trees, while elsewhere the extent of bank retreat was negligible. On the grassy bank, retreat was controlled by the creation of small overhanging clumps of turf at the top of the bank, their occasional failure, and the ultimate removal of failed debris from the bank toe. Partial autocorrelation analysis of vertically integrated bank retreat demonstrates that bank profile erosion is virtually uncorrelated at horizontal distances greater than about 1 m on both banks, a length scale of approximately 1/2 the bank height. This extensive streamwise variability suggests that widely spaced profile data cannot adequately represent bank erosion at these sites. Additional analysis of our comprehensive spatial data also indicates that traditional bank profile surveys with any spacing greater than 1 m would result in measurement errors exceeding 10%, an important conclusion for assessing annual rates of mercury loading into the South River from bank erosion. Our results suggest that 3-dimensional gridded bare-earth models of bank topography may be required to accurately measure annual bank retreat in similar river systems.

  18. Influence of agricultural practice on trace metals in soils and vegetation in the water conservation area along the East River (Dongjiang River), South China

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Chunling, E-mail: clluo@gig.ac.cn [Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Yang, Renxiu [Department of Civil and Structural Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Wang, Yan; Li, Jun; Zhang, Gan [Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Li, Xiangdong [Department of Civil and Structural Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong)

    2012-08-01

    Dongjiang (East River) is the key resource of potable water for the Pearl River Delta region, South China. Although industrial activities are limited in the water conservation area along this river, agriculture is very intensive. The present study evaluated trace metals in four soils under different cultivation. The total concentrations of trace metals decreased in the order orchard soil > vegetable soil > paddy soil > natural soil, reflecting decreasing inputs of agrochemicals to soils. Relatively high concentrations of Cd were recorded in the 60-cm soil profiles. The {sup 206}Pb/{sup 207}Pb ratio in the above-ground tissues of plant was significantly lower than their corresponding soils. In combination with the low transfer factor of Pb from soil to plant shoots, atmospheric deposition is probably a major pathway for Pb to enter plant leaves. Regular monitoring on the soil quality in this area is recommended for the safety of water resource and agricultural products. - Highlights: Black-Right-Pointing-Pointer Soil Cd exceeded the upper limit of Chinese standard for agricultural soils. Black-Right-Pointing-Pointer Relatively high concentrations of Cd were recorded in the 60-cm soil profiles. Black-Right-Pointing-Pointer Agricultural soil had higher concentrations of metals and lower {sup 206}Pb/{sup 207}Pb ratios. Black-Right-Pointing-Pointer Pb in above-ground tissues of plant was more anthropogenic than soil. Black-Right-Pointing-Pointer Atmospheric deposition may be a major pathway for Pb to enter plant leaves.

  19. Sulfate migration in a river affected by acid mine drainage from the Dabaoshan mining area, South China.

    Science.gov (United States)

    Chen, Meiqin; Lu, Guining; Guo, Chuling; Yang, Chengfang; Wu, Jingxiong; Huang, Weilin; Yee, Nathan; Dang, Zhi

    2015-01-01

    Sulfate, a major component of acid mine drainage (AMD), its migration in an AMD-affected river which located at the Dabaoshan mine area of South China was investigated to pursue the remediation strategy. The existing factors of relatively low pH values of 2.8-3.9, high concentrations of SO4(2-) (∼1940 mg L(-1)) and Fe(3+) (∼112 mg L(-1)) facilitated the precipitation of schwertmannite (Fe8O8(OH)6SO4·nH2O) in the upstream river. Geochemical model calculations implied the river waters were supersaturated, creating the potential for precipitation of iron oxyhydroxides. These minerals evolved from schwertmannite to goethite with the increasing pH from 2.8 to 5.8 along the river. The concentration of heavy metals in river waters was great reduced as a result of precipitation effects. The large size of the exchangeable sulfate pool suggested that the sediments had a strong capacity to bind SO4(2-). The XRD results indicated that schwertmannite was the predominant form of sulfate-bearing mineral phases, which was likely to act as a major sulfate sink by incorporating water-borne sulfate into its internal structure and adsorbing it onto its surface. The small size of reduced sulfur pools and strong oxidative status in the surface sediments further showed that SO4(2-) shifting from water to sediment in form of sulfate reduction was not activated. In short, precipitation of sulfate-rich iron oxyhydroxides and subsequent SO4(2-) adsorption on these minerals as well as water dilution contributed to the attenuation of SO4(2-) along the river waters. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Streamflow gain and loss and water quality in the upper Nueces River Basin, south-central Texas, 2008-10

    Science.gov (United States)

    Banta, J. Ryan; Lambert, Rebecca B.; Slattery, Richard N.; Ockerman, Darwin J.

    2012-01-01

    The U.S. Geological Survey-in cooperation with the U.S. Army Corps of Engineers, The Nature Conservancy, the Real Edwards Conservation and Reclamation District, and the Texas Parks and Wildlife Department-investigated streamflow gain and loss and water quality in the upper Nueces River Basin, south-central Texas, specifically in the watersheds of the West Nueces, Nueces, Dry Frio, Frio, and Sabinal Rivers upstream from the Edwards aquifer outcrop. Streamflow in these rivers is sustained by groundwater contributions (for example, from springs) and storm runoff from rainfall events. To date (2012), there are few data available that describe streamflow and water-quality conditions of the rivers within the upper Nueces River Basin. This report describes streamflow gain-loss characteristics from three reconnaissance-level synoptic measurement surveys (hereinafter referred to as "surveys") during 2008-10 in the upper Nueces River Basin. To help characterize the hydrology, groundwater-level measurements were made, and water-quality samples were collected from both surface-water and groundwater sites in the study area from two surveys during 2009-10. The hydrologic (streamflow, springflow, and groundwater) measurements were made during three reconnaissance-level synoptic measurement surveys occurring in July 21-23, 2008; August 8-18, 2009; and March 22-24, 2010. These survey periods were selected to represent different hydrologic conditions. Streamflow gains and losses were based on streamflow and springflow measurements made at 74 sites in the study area, although not all sites were measured during each survey. Possible water chemistry relations among sample types (streamflow, springflow, or groundwater), between surveys, and among watersheds were examined using water-quality samples collected from as many as 20 sites in the study area.

  1. Hydrogeologic framework and groundwater/surface-water interactions of the South Fork Nooksack River Basin, northwestern Washington

    Science.gov (United States)

    Gendaszek, Andrew S.

    2014-01-01

    A hydrogeologic framework of the South Fork (SF) Nooksack River Basin in northwestern Washington was developed and hydrologic data were collected to characterize the groundwater-flow system and its interaction with surface‑water features. In addition to domestic, agricultural, and commercial uses of groundwater within the SF Nooksack River Basin, groundwater has the potential to provide ecological benefits by maintaining late-summer streamflows and buffering stream temperatures. Cold-water refugia, created and maintained in part by groundwater, have been identified by water-resource managers as key elements to restore the health and viability of threatened salmonids in the SF Nooksack River. The SF Nooksack River drains a 183-square mile area of the North Cascades and the Puget Lowland underlain by unconsolidated glacial and alluvial sediments deposited over older sedimentary, metamorphic, and igneous bedrock. The primary aquifer that interacts with the SF Nooksack River was mapped within unconsolidated glacial outwash and alluvial sediment. The lower extent of this unit is bounded by bedrock and fine-grained, poorly sorted unconsolidated glaciomarine and glaciolacustrine sediments. In places, these deposits overlie and confine an aquifer within older glacial sediments. The extent and thickness of the hydrogeologic units were assembled from mapped geologic units and lithostratigraphic logs of field-inventoried wells. Generalized groundwater-flow directions within the surficial aquifer were interpreted from groundwater levels measured in August 2012; and groundwater seepage gains and losses to the SF Nooksack River were calculated from synoptic streamflow measurements made in the SF Nooksack River and its tributaries in September 2012. A subset of the field-inventoried wells was measured at a monthly interval to determine seasonal fluctuations in groundwater levels during water year 2013. Taken together, these data provide the foundation for a future groundwater

  2. Seasonal variation and partitioning of endocrine disrupting chemicals in waters and sediments of the Pearl River system, South China.

    Science.gov (United States)

    Gong, Jian; Duan, Dandan; Yang, Yu; Ran, Yong; Chen, Diyun

    2016-12-01

    Endocrine disrupting chemicals (EDCs) were seasonally investigated in surface water, suspended particulate matter, and sediments of the Pearl River Delta (PRD), South China. EDC concentrations in the surface water were generally higher in the summer than in winter. The surface water in the investigated rivers was heavily contaminated by the phenolic xenoestrogens. Moreover, the in-situ log Ksoc and log Kpoc values and their regression with log Kow in the field experiments suggest that binding mechanisms other than hydrophobic interaction are present for the sedimentary organic carbon and particulate organic carbon (SOC/POC). The logKsoc-logKow and logKpoc-logKow regression analyses imply that higher complexity of nonhydrophobic interactions with EDCs is present on the SOC samples comparing with the POC samples, which is related to their different sources.

  3. Mercury profiles in sediments of the Pearl River Estuary and the surrounding coastal area of South China.

    Science.gov (United States)

    Shi, Jian-bo; Ip, Carman C M; Zhang, Gan; Jiang, Gui-bin; Li, Xiang-dong

    2010-05-01

    The spatial and temporal variations of mercury (Hg) in sediments of the Pearl River Estuary (PRE) and the surrounding coastal area (South China Sea) were studied. In surface sediments, the concentrations of Hg ranged from 1.5 to 201ng/g, with an average of 54.4ng/g, displaying a decreasing trend with the distance from the estuary to the open sea. This pattern indicates that the anthropogenic emissions from the Pearl River Delta (PRD) region are probably the main sources of Hg in this coastal region. Using the (210)Pb dating technique, the historical changes in the concentrations and influxes of Hg in the last 100 years were also investigated. The variations in Hg influxes in sediment cores obviously correlate with the economic development and urbanization that has occurred the PRD region, especially in the last three decades.

  4. Occurrence of Clinostomum complanatum in Aphanius dispar (Actinoptrygii:Cyprinodontidae) collected from Mehran River, Hormuzgan Province, South of Iran

    Institute of Scientific and Technical Information of China (English)

    Gholami Z; Mobedi I; Esmaeili HR; Kia EB

    2011-01-01

    Objective: To investigate the possibility of Aphanius dispar (A.dispar) acting as intermediate host for Clinostomum complanatum (C. complanatum), from Mehran River, Hormuzgan Province of Iran. Methods: During a biological study of A. dispar in Mehran River, Hormuzgan Province, South of Iran, a total of 97 fish specimens were collected in 24 January 2006. Results:4 specimens (4.12%) including 1 male and 3 female were found infected with C. complanatum metacercaria. These metacercaria were coiled in the epiderm on the body surface of infected fishes. The infection is known as yellow spot disease. The parasite abundance, intensity and prevalence were 0.05%, 1.25% and 4.12%, respectively. The infection was higher in females than males. Conclusions: To the best of our knowledge, this is the first report on occurrence of C. complanatum metacercaria in A. dispar in Iran.

  5. Near-decadal changes in nitrate and pesticide concentrations in the South Platte River alluvial aquifer, 1993-2004

    Science.gov (United States)

    Paschke, S.S.; Schaffrath, K.R.; Mashbum, S.L.

    2008-01-01

    The lower South Platte River basin of Colorado and Nebraska is an area of intense agriculture supported by surface-water diversions from the river and ground-water pumping from a valley-fill alluvial aquifer. Two well networks consisting of 45 wells installed in the South Platte alluvial aquifer were sampled in the early 1990s and again in the early 2000s to examine near-decadal ground-water quality changes in irrigated agricultural areas. Ground-water age generally increases and dissolved-oxygen content decreases with distance along flow paths and with depdi below the water table, and denitrification is an important natural mitigation mechanism for nitrate in downgradient areas. Ground-water travel time from upland areas to the river ranges from 12 to 31 yr on the basis of apparent ground-water ages. Ground-water nitrate concentrations for agricultural land-use wells increased significantly for oxidized samples over the decade, and nitrogen isotope ratios for oxidized samples indicate synthetic fertilizer as the predominant nitrate source. Ground-water concentrations of atrazine, DEA, and prometon decreased significandy. The decrease in pesticide concentrations and a significant increase in the ratio of DEA to atrazine suggest decreases in pesticide concentrations are likely caused by local decreases in application rates and/or degradation processes and that atrazine degradation is promoted by oxidizing conditions. The difference between results for oxidizing and nitrate-reducing conditions indicates redox state is an important variable to consider when evaluating ground-water quality trends for redox-sensitive constituents such as nitrate and pesticides in the South Platte alluvial aquifer. Copyright ?? 2008 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

  6. Aquatic health assessment of the Steelpoort River System, Limpopo, South Africa

    OpenAIRE

    Magala, Musatondwa

    2015-01-01

    Abstract: The Olifants River Water Resource Development Project (ORWRDP) is a multipurpose project incorporating both economic and social development objectives to cater for the water demands of commercial and social users. Phase 2 of the project encompassed the construction of the De Hoop Dam within the Steelpoort River basin and bulk water transfer pipelines. During this study, various water quality assessment techniques were conducted along the length of the Steelpoort River from a site si...

  7. A preliminary investigation on the occurrence and distribution of antibiotic resistance genes in the Beijiang River, South China

    Institute of Scientific and Technical Information of China (English)

    Zhenhao Ling; Ying Yang; Yuanli Huang; Shichun Zou; Tiangang Luan

    2013-01-01

    The occurrence of antibiotic resistance genes (ARGs) was investigated and quantified in 20 water samples collected in the Beijiang River,South China.Sulfonamide-and tetracycline-resistant bacteria were present in 17 and 14 of the collected 20 samples.For sulfonamide ARGs,sulⅠ and sulⅡ were frequently observed in the Beijiang River.The levels of sulⅠ were higher than sulⅡ (p < 0.05),with the mean values of (1.41 ± 1.12) × 10-2 and (1.58 ± 1.71) × 10-3 copies/16S rDNA,respectively.For tetracycline ARGs,tetG had the highest frequency,100%,followed by tetA (85%),tetO (85%),tetC (70%),tetX (60%),tetM (40%) and tetQ (20%),while tetE and tetS were not detected in all the samples from the Beijiang River.On the other hand,tetC had the highest concentration,ranging from 8.30 × 10-2 to 13.20 copies/16S rDNA.The poor correlation between ARGs and antibiotic concentrations revealed that the self-amplification and persistence of ARGs were the reasons that made ARGs exist in the water environment even though the antibiotic selecting pressure was absent.Because so few field measurements have been conducted for investigating the levels of ARGs in rivers in South China,this study provides an important insight on better understanding the occurrence and spread of ARGs in such an ecosystem.

  8. Photo-nucleation theory of correlation of Stream-flow of four South American rivers with Sunspot Cycle

    CERN Document Server

    Brown, W Byers

    2011-01-01

    C.T.R.Wilson showed that when supersaturated water vapour was exposed to ultraviolet radiation from sunlight or other sources in the presence of oxygen it immediately condensed to form an aerosol. This phenomenon was eventually explained as due to the formation of a charge-transfer complex H2O+O2-, whose existence was confirmed theoretically and subsequently established experimentally. It is proposed that the correlation recently discovered between the stream-flow of the Parana and three other rivers in South America and the solar sunspot cycle is due to the photo-nucleation mechanism investigated by Wilson.

  9. South Asian summer monsoon variability during the last ~54 kyrs inferred from surface water salinity and river run off proxies

    Digital Repository Service at National Institute of Oceanography (India)

    Gebregiorgis, D.; Hathorne, E.C.; Sijinkumar, A.V; Nath, B.N.; Nurnberg, D.; Frank, M.

    : Quat. Sci. Rev., vol.138; 2016; 6-15 South Asian Summer Monsoon variability during the last ~54 kyrs inferred from surface water salinity and river run off proxies D. Gebregiorgis1, E.C. Hathorne1, A.V. Sijinkumar2, B. Nagender Nath3, D. Nürnberg... leach with 100 μL 0.001 M HNO3 was applied and followed by two rinses with distilled water. Samples were dissolved in 0.075 M nitric acid (HNO3) (500 μL) assisted by sonication for 25 mins.   6 Finally samples were centrifuged for 4 mins at 13400 rpm...

  10. Flood-inundation maps for an 8.9-mile reach of the South Fork Little River at Hopkinsville, Kentucky

    Science.gov (United States)

    Lant, Jeremiah G.

    2013-01-01

    Digital flood-inundation maps for an 8.9-mile reach of South Fork Little River at Hopkinsville, Kentucky, were created by the U.S. Geological Survey (USGS) in cooperation with the City of Hopkinsville Community Development Services. The inundation maps, which can be accessed through the USGS Flood Inundation Mapping Science Web site at http://water.usgs.gov/osw/flood_inundation/ depict estimates of the areal extent and depth of flooding corresponding to selected water levels (stages) at the USGS streamgage at South Fork Little River at Highway 68 By-Pass at Hopkinsville, Kentucky (station no. 03437495). Current conditions for the USGS streamgage may be obtained online at the USGS National Water Information System site (http://waterdata.usgs.gov/nwis/inventory?agency_code=USGS&site_no=03437495). In addition, the information has been provided to the National Weather Service (NWS) for incorporation into their Advanced Hydrologic Prediction Service flood warning system (http://water.weather.gov/ahps/). The NWS forecasts flood hydrographs at many places that are often co-located at USGS streamgages. The forecasted peak-stage information, also available on the Internet, may be used in conjunction with the maps developed in this study to show predicted areas of flood inundation. In this study, flood profiles were computed for the South Fork Little River reach by using HEC-RAS, a one-dimensional step-backwater model developed by the U.S. Army Corps of Engineers. The hydraulic model was calibrated by using the most current (2012) stage-discharge relation at the South Fork Little River at Highway 68 By-Pass at Hopkinsville, Kentucky, streamgage and measurements collected during recent flood events. The calibrated model was then used to calculate 13 water-surface profiles for a sequence of flood stages, most at 1-foot intervals, referenced to the streamgage datum and ranging from a stage near bank full to the estimated elevation of the 1.0-percent annual exceedance

  11. Preliminary inventory and classification of indigenous afromontane forests on the Blyde River Canyon Nature Reserve, Mpumalanga, South Africa

    Directory of Open Access Journals (Sweden)

    Beck Hans T

    2004-08-01

    Full Text Available Abstract Background Mixed evergreen forests form the smallest, most widely distributed and fragmented biome in southern Africa. Within South Africa, 44% of this vegetation type has been transformed. Afromontane forest only covers 0.56 % of South Africa, yet it contains 5.35% of South Africa's plant species. Prior to this investigation of the indigenous forests on the Blyde River Canyon Nature Reserve (BRCNR, very little was known about the size, floristic composition and conservation status of the forest biome conserved within the reserve. We report here an inventory of the forest size, fragmentation, species composition and the basic floristic communities along environmental gradients. Results A total of 2111 ha of forest occurs on Blyde River Canyon Nature Reserve. The forest is fragmented, with a total of 60 forest patches recorded, varying from 0.21 ha to 567 ha in size. On average, patch size was 23 ha. Two forest communities – high altitude moist afromontane forest and low altitude dry afromontane forest – are identified. Sub-communities are recognized based on canopy development and slope, respectively. An altitudinal gradient accounts for most of the variation within the forest communities. Conclusion BRCNR has a fragmented network of small forest patches that together make up 7.3% of the reserve's surface area. These forest patches host a variety of forest-dependent trees, including some species considered rare, insufficiently known, or listed under the Red Data List of South African Plants. The fragmented nature of the relatively small forest patches accentuates the need for careful fire management and stringent alien plant control.

  12. South Fork Shenandoah River habitat-flow modeling to determine ecological and recreational characteristics during low-flow periods

    Science.gov (United States)

    Krstolic, Jennifer L.; Ramey, R. Clay

    2012-01-01

    The ecological habitat requirements of aquatic organisms and recreational streamflow requirements of the South Fork Shenandoah River were investigated by the U.S. Geological Survey in cooperation with the Central Shenandoah Valley Planning District Commission, the Northern Shenandoah Valley Regional Commission, and Virginia Commonwealth University. Physical habitat simulation modeling was conducted to examine flow as a major determinant of physical habitat availability and recreation suitability using field-collected hydraulic habitat variables such as water depth, water velocity, and substrate characteristics. Fish habitat-suitability criteria specific to the South Fork Shenandoah River were developed for sub-adult and adult smallmouth bass (Micropterus dolomieu), juvenile and sub-adult redbreast sunfish (Lepomis auritus), spotfin or satinfin shiner (Cyprinella spp), margined madtom (Noturus insignis),and river chub (Nocomis micropogon). Historic streamflow statistics for the summer low-flow period during July, August, and September were used as benchmark low-flow conditions and compared to habitat simulation results and water-withdrawal scenarios based on 2005 withdrawal data. To examine habitat and recreation characteristics during droughts, daily fish habitat or recreation suitability values were simulated for 2002 and other selected drought years. Recreation suitability during droughts was extremely low, because the modeling demonstrated that suitable conditions occur when the streamflows are greater than the 50th percentile flow for July, August, and September. Habitat availability for fish is generally at a maximum when streamflows are between the 75th and 25th percentile flows for July, August, and September. Time-series results for drought years, such as 2002, showed that extreme low-flow conditions less than the 5th percentile of flow for July, August, and September corresponded to below-normal habitat availability for both game and nongame fish in the

  13. Comparison of Methylmercury Production and Accumulation in Sediments of the Congaree and Edisto River Basins, South Carolina, 2004-06

    Science.gov (United States)

    Bradley, Paul M.; Chapelle, Francis H.; Journey, Celeste

    2009-01-01

    Fish-tissue mercury concentrations (approximately 2 micrograms per gram) in the Edisto River basin of South Carolina are among the highest recorded in the United States. Substantially lower mercury concentrations (approximately 0.2 microgram per gram) are reported in fish from the adjacent (about 30 kilometer) Congaree River basin and the Congaree National Park. In contrast, concentrations of total mercury were statistically higher in sediments from the Congaree River compared with those in sediments from the Edisto River. Furthermore, no statistically significant difference was observed in concentrations of methylmercury or net methylation potential in sediments collected from various Edisto and Congaree hydrologic settings. In both systems, the net methylation potential was low (0-0.17 nanogram per gram per day) for in-stream sediments exposed to continuously flowing water but substantially higher (about 1.8 nanograms per gram per day) in wetland sediments exposed to standing water. These results are not consistent with the hypothesis that differences in fish-tissue mercury between the Edisto and Congaree basins reflect fundamental differences in the potential for each system to methylate mercury. Rather, the significantly higher ratios of methylmercury to total mercury observed in the Edisto system suggest that the net accumulation and(or) preservation of methylmercury are greater in the Edisto system. The marked differences in net methylation potential observed between the wetland and in-stream settings suggest the hypothesis that methylmercury transport from zones of production (wetlands) to points of entry into the food chain (channels) may contribute to the observed differences in fish-tissue mercury concentrations between the two river systems.

  14. UMRR Topobathy Data (Tier 3) of Mississippi Pools 25, Open River North, Open River South and Illinois River Starved Rock Reach

    Science.gov (United States)

    Stone, Jayme; Rogala, James T.; Sattler, Stephanie; Hanson, Jenny L.

    2016-01-01

    These data are associated with the U.S. Army Corps of Engineers’ Upper Mississippi River Restoration (UMRR) Program project to generate high resolution elevation datasets for the Upper Mississippi River floodplain, between Minneapolis, MN, and Cairo, IL and the Illinois River. The Tier 1 data sets were designed to make the lidar data publicly available as soon as possible. The Tier 2 data have undergone quality assurance testing, water-masking, contour-smoothing, and point-reclassification where necessary, and have been approved for release by the USGS. The Tier 3 data are products of bathymetry merged with terrestrial lidar. UMESC is the lead office for the final processing of these data, which includes additional quality control and serving the data on the UMRR Long Term Resource Monitoring (LTRM) element’s website.

  15. Benefit Transfer for Water Management along the Han River in South Korea Using Meta-Regression Analysis

    Directory of Open Access Journals (Sweden)

    Hio-Jung Shin

    2016-10-01

    Full Text Available This study estimates the magnitude of economic benefits that are justified in transfer from downstream users to upstream users for the use of the Han River in South Korea in terms of foregone economic benefits by regulations. Based on the existing non-market valuation studies associated with water management issues in South Korea from 1997 to 2014, a meta-regression analysis was performed to provide alternatives for regional benefit sharing of water resource use. The benefits from the use of water resource along the Han River are estimated on average to be KRW 7,728 (US $7.7 per household per month. The total net benefits are estimated to be about KRW 449 billion (US $449 million per year. Following the principle regarding equal distribution of benefits, the stakeholders who received more net benefits than others should return their extra net benefits to other stakeholders through a policy tool such as tradable development rights. The results of our study provide economic indicators useful for the establishment of common resource policy and to consider stakeholders’ rights within the framework of regional benefits. This study also provides practical solutions that could be used as a valid policy instrument to mediate the conflicts and disputes associated with water resource use.

  16. Assessment of physico-chemical qualities and heavy metal concentrations of Umgeni and Umdloti Rivers in Durban, South Africa.

    Science.gov (United States)

    Olaniran, Ademola O; Naicker, Kovashnee; Pillay, Balakrishna

    2014-04-01

    We assessed the effects of seasonal dynamics on the physico-chemical qualities and heavy metals concentrations of the Umgeni and Umdloti Rivers in Durban, South Africa. Water samples were taken from nine different sampling points and analysed for the following parameters; temperature, pH, turbidity, electrical conductivity (EC), biological oxygen demand (BOD5), chemical oxygen demand (COD), phosphate (PO4(2-)), nitrate (NO3(2-)), ammonium (NH4(+)), sulphate (SO4(2-)), lead (Pb(2+)), mercury (Hg(2+)), cadmium (Cd(2+)), aluminium (Al(3+)), and copper (Cu(2+)) using standard methods. The data showed variations it terms of the seasonal fluctuations and sampling regime as follows: temperature 12-26.5 °C; pH 5.96-8.45; turbidity 0.53-18.8 NTU; EC 15.8-5180 mS m(-1); BOD5 0.60-7.32 mg L(-1); COD 10.5-72.9 mg L(-1); PO4 (2-) South African Guidelines and World Health Organization tolerance limits for freshwater quality. We conclude that these water bodies are potentially hazardous to public health and this highlights the need for implementation of improved management strategies of these river catchments for continued sustainability.

  17. Simulation of Temperature, Nutrients, Biochemical Oxygen Demand, and Dissolved Oxygen in the Catawba River, South Carolina, 1996-97

    Science.gov (United States)

    Feaster, Toby D.; Conrads, Paul A.; Guimaraes, Wladmir B.; Sanders, Curtis L.; Bales, Jerad D.

    2003-01-01

    Time-series plots of dissolved-oxygen concentrations were determined for various simulated hydrologic and point-source loading conditions along a free-flowing section of the Catawba River from Lake Wylie Dam to the headwaters of Fishing Creek Reservoir in South Carolina. The U.S. Geological Survey one-dimensional dynamic-flow model, BRANCH, was used to simulate hydrodynamic data for the Branched Lagrangian Transport Model. Waterquality data were used to calibrate the Branched Lagrangian Transport Model and included concentrations of nutrients, chlorophyll a, and biochemical oxygen demand in water samples collected during two synoptic sampling surveys at 10 sites along the main stem of the Catawba River and at 3 tributaries; and continuous water temperature and dissolved-oxygen concentrations measured at 5 locations along the main stem of the Catawba River. A sensitivity analysis of the simulated dissolved-oxygen concentrations to model coefficients and data inputs indicated that the simulated dissolved-oxygen concentrations were most sensitive to watertemperature boundary data due to the effect of temperature on reaction kinetics and the solubility of dissolved oxygen. Of the model coefficients, the simulated dissolved-oxygen concentration was most sensitive to the biological oxidation rate of nitrite to nitrate. To demonstrate the utility of the Branched Lagrangian Transport Model for the Catawba River, the model was used to simulate several water-quality scenarios to evaluate the effect on the 24-hour mean dissolved-oxygen concentrations at selected sites for August 24, 1996, as simulated during the model calibration period of August 23 27, 1996. The first scenario included three loading conditions of the major effluent discharges along the main stem of the Catawba River (1) current load (as sampled in August 1996); (2) no load (all point-source loads were removed from the main stem of the Catawba River; loads from the main tributaries were not removed); and (3

  18. A coupled monitoring network to conduct an assessment of mercury transformation and mobilization in floodplain soils: South River, Virginia

    Science.gov (United States)

    Lazareva, O.; Sparks, D. L.; Landis, R.; Ptacek, C. J.; Hicks, S.; Montgomery, D.

    2013-12-01

    Mercury (Hg) was used between 1929 and 1950 by the DuPont plant in the production of rayon acetate fiber in Waynesboro, Virginia and released into the South River. The contamination of Hg was discovered in the 1970s and remained elevated in water, soil, sediments, and biota. The primary goal of this study is to investigate the processes that govern biogeochemical transformation and mobilization of Hg in floodplain soils at South River Mile 3.5, characterize geochemical gradients in soils and how they change over time, and to enable targeted sampling at Hg loading hot spots. The biogeochemical data will play a supporting role and be used to further develop our understanding of the processes controlling the leaching of Hg and our conceptual model. Our over-arching hypothesis is to test if leaching of bank soils is a significant source of dissolved or colloidal inorganic Hg. This effort requires an interdisciplinary geochemical approach and sensor technology to understand the interactions between floodplain soil, groundwater, and river. Our investigation will include 10 months' worth data from a number of state-of-the-art in-situ monitoring sensors, such as custom-designed redox probes, soil moisture, temperature, pressure, and conductivity installed at the site. Our preliminary results showed that the concentration of total Hg in soils was up to 900 mg/kg (wet weight).There is a significant redox gradient across the floodplain soil profile. Within the top 40 -70 cm, major changes in redox conditions from oxidizing (Eh ≈+600 mV) to very reducing (Eh ≈-300 mV) corresponded to heavy rainfall and overbank flooding events. High variations in stream stage may govern the surface water - groundwater exchange facilitating the downward or upward movement of the capillary fringe and saturated zone through the soil horizons, affecting soil redox potential, stability of Hg-bearing minerals and leaching of inorganic Hg into dissolved and colloidal phases. These phases may be

  19. Charleston Harbor Deepening Project. Charleston Harbor and Shipyard River, South Carolina.

    Science.gov (United States)

    1976-04-01

    mantis shrimp , grass shrimp , isopods, amphipods, and harnacles. 2.13.5.2. The American oyster is the most common pele- 0 cv~od mollusk found in the...remainder * being consumed by detritus feeding organisms such as amphipods, • isonods and decapod crustaceans ( shrimp and crabs), and fishes. * 0 45 0 * W U...Ashley River also serves as a nursery for blue crabs, brown and white shrimp , and various marine finfish. 2.13.3.4. Wando River. The Wando River generally

  20. Use of landscape-level river signatures in conservation planning: a South African case study

    CSIR Research Space (South Africa)

    Roux, D

    2002-12-01

    Full Text Available .3 Spider (including all four arms) Seasonal 11.3 Se-11.3 The Greater Addo Elephant National Park (GAENP) freshwater study identified and described four freshwater processes of importance (see Forman 1995, Ward 1998, Barber-James et al. 2002... of the study is that 16 of the 31 rivers considered had to be conserved to achieve adequate representation of the biodiversity patterns identified. Based on ecosystem processes, the Diep Kloof River and a river we called the Spider (the name is given...

  1. Assessing Hydrologic Impacts of Future Land Cover Change Scenarios in the South Platte River Basin (CO, WY, & NE) and the San Pedro River Basin (U.S./Mexico).

    Science.gov (United States)

    Barlow, J. E.; Burns, I. S.; Guertin, D. P.; Kepner, W. G.; Goodrich, D. C.

    2016-12-01

    Long-term land-use and land cover change and their associated impacts pose critical challenges to sustaining vital hydrological ecosystem services for future generations. In this study, a methodology to characterize hydrologic impacts from future urban growth through time that was developed and applied on the San Pedro River Basin was expanded and utilized on the South Platte River Basin as well. Future urban growth is represented by housing density maps generated in decadal intervals from 2010 to 2100, produced by the U.S. Environmental Protection Agency (EPA) Integrated Climate and Land-Use Scenarios (ICLUS) project. ICLUS developed future housing density maps by adapting the Intergovernmental Panel on Climate Change (IPCC) Special Report on Emissions Scenarios (SRES) social, economic, and demographic storylines to the conterminous United States. To characterize hydrologic impacts from future growth, the housing density maps were reclassified to National Land Cover Database (NLCD) 2006 land cover classes and used to parameterize the Soil and Water Assessment Tool (SWAT) using the Automated Geospatial Watershed Assessment (AGWA) tool. The objectives of this project were to 1) develop and implement a methodology for adapting the ICLUS data for use in AGWA as an approach to evaluate impacts of development on water-quantity and -quality, 2) present, evaluate, and compare results from scenarios for watersheds in two different geographic and climatic regions, 3) determine watershed specific implications of this type of future land cover change analysis.

  2. Reconnaissance survey of site 7 of the proposed Three Rivers Regional Landfill and Technology Center, Savannah River Site, Aiken County, South Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Cabak, M.A.; Beck, M.L.; Gillam, C.; Sassaman, K.E.

    1996-02-01

    This report documents the archaeological investigation of Site 7 of the proposed Three Rivers Regional Landfill and Technology Center in Aiken County on the United States Department of Energy`s Savannah River Site (SRS) in Aiken and Barnwell Counties, South Carolina. Pedestrian and subsurface survey techniques were used to investigate the 1,403-acre project area. Survey resulted in the discovery of 23 previously unrecorded sites and 11 occurrences; six previously recorded sites were also investigated. These sites consist of six prehistoric sites, nine historic sites, and 14 sites with both prehistoric and historic components. Sites locations and project area boundaries are provided on a facsimile of a USGS 7.5 topographic map. The prehistoric components consist of very small, low-density lithic and ceramic scatters; most contain less than 10 artifacts. Six of the prehistoric components are of unknown cultural affiliation, the remaining prehistoric sites were occupied predominately in the Woodland period. The historic sites are dominated by postbellum/modem home places of tenant and yeoman farmers but four historic sites were locations of antebellum house sites (38AK136, 38AK613, 38AK660, and 38AK674). The historic sites also include an African-American school (38AK677).

  3. Using the Bayesian network relative risk model risk assessment process to evaluate management alternatives for the South River and upper Shenandoah River, Virginia.

    Science.gov (United States)

    Johns, Annie F; Graham, Scarlett E; Harris, Meagan J; Markiewicz, April J; Stinson, Jonah M; Landis, Wayne G

    2017-01-01

    We have conducted a series of regional scale risk assessments using the Bayesian Network Relative Risk Model (BN-RRM) to evaluate the efficacy of 2 remediation options in the reduction of risks to the South River and upper Shenandoah River study area. The 2 remediation options were 1) bank stabilization (BST) and 2) the implementation of best management practices for agriculture (AgBMPs) to reduce Hg input in to the river. Eight endpoints were chosen to be part of the risk assessment, based on stakeholder input. Although Hg contamination was the original impetus for the site being remediated, multiple chemical and physical stressors were evaluated in this analysis. Specific models were built that incorporated the changes expected from AgBMP and BST and were based on our previous research. Changes in risk were calculated, and sensitivity and influence analyses were conducted on the models. The assessments indicated that AgBMP would only slightly change risk in the study area but that negative impacts were also unlikely. Bank stabilization would reduce risk to Hg for the smallmouth bass and belted kingfisher and increase risk to abiotic water quality endpoints. However, if care were not taken to prevent loss of nesting habitat to belted kingfisher, an increase in risk to that species would occur. Because Hg was only one of several stressors contributing to risk, the change in risk depended on the specific endpoint. Sensitivity analysis provided a list of variables to be measured as part of a monitoring program. Influence analysis provided the range of maximum and minimum risk values for each endpoint and remediation option. This research demonstrates the applicability of ecological risk assessment and specifically the BN-RRM as part of a long-term adaptive management scheme for managing contaminated sites. Integr Environ Assess Manag 2017;13:100-114. © 2016 SETAC.

  4. Design for participation in ecologically sound management of South Africa's Mlazi River Catchment

    NARCIS (Netherlands)

    Auerbach, R.

    1999-01-01

    Without local participation, integrated catchment management and Landcare will not become a general reality in South Africa. With support from the South African Water Research Commission, the University of Natal's Farmer Support Group set up the Ntshongweni Catchment Management Programme (NCMP) as a

  5. Design for participation in ecologically sound management of South Africa's Mlazi River catchment

    NARCIS (Netherlands)

    Auerbach, R.

    1999-01-01

    Without local participation, integrated catchment management and Landcare will not become a general reality in South Africa. With support from the South African Water Research Commission, the University of Natal's Farmer Support Group set up the Ntshongweni Catchment Management Programme

  6. Little River Inlet Navigation Project, Brunswick County, North Carolina and Horry County, South Carolina. Revision.

    Science.gov (United States)

    1977-06-01

    truitti + + Phylum Cnidaria Ectopleura duinorti-pri + + Turritopsis nutricula + + Hydractiniidac (undet.) + Bougainvillia rugosa + Carveia franciscana...Department of Commerce Forest Service, USDA Soil Conservation Service, USDA Department of Health , Education, and Welfare Department of Housing and...Carolina Department of Natural and Economic Resources South Carolina Wildlife and Marine Resources Department South Carolina Department of Health and

  7. An evaluation of the effect of future climate on runoff in the Dongjiang River basin, South China

    Science.gov (United States)

    Lin, K.; Zhai, W.; Huang, S.; Liu, Z.

    2015-05-01

    The impact of future climate change on the runoff for the Dongjiang River basin, South China, has been investigated with the Soil and Water Assessment Tool (SWAT). First, the SWAT model was applied in the three sub-basins of the Dongjiang River basin, and calibrated for the period of 1970-1975, and validated for the period of 1976-1985. Then the hydrological response under climate change and land use scenario in the next 40 years (2011-2050) was studied. The future weather data was generated by using the weather generators of SWAT, based on the trend of the observed data series (1966-2005). The results showed that under the future climate change and LUCC scenario, the annual runoff of the three sub-basins all decreased. Its impacts on annual runoff were -6.87%, -6.54%, and -18.16% for the Shuntian, Lantang, and Yuecheng sub-basins respectively, compared with the baseline period 1966-2005. The results of this study could be a reference for regional water resources management since Dongjiang River provides crucial water supplies to Guangdong Province and the District of Hong Kong in China.

  8. The Han River watershed management initiative for the South-to-North Water Transfer project (Middle Route) of China.

    Science.gov (United States)

    Zhang, Quanfa; Xu, Zhifang; Shen, Zehao; Li, Siyue; Wang, Shusen

    2009-01-01

    The South-to-North Water Transfer (SNWT) Project of China is the largest of its kind ever implemented. Of its three routes (i.e., East, Middle and West), the middle one will transfer 14 billion m(3) of water annually from the Han River, a tributary of the Yangtze and the water supplying area, to Beijing by 2030. Thus water quality in the 95,000 km(2) upper Han River basin is of great concern. A watershed management initiative has been implemented in the basin, and the ultimate objectives are to quantify basin's ecosystem functioning and to develop an integrated management system with respect to water resources conservation. Specifically, the program includes five activities: characterization of riparian ecosystems, detection of land use and land cover change, quantification of nutrient cycling of representative ecosystems, determination of spatial and temporal variations of water quality, and finally development of a watershed management system for water conservation. This article provides the justifications of the watershed management initiative and the initial results are comprehended with respect to the water conservation in the Han River basin.

  9. The river basin game as a tool for collective water management at community level in South Africa

    Science.gov (United States)

    Magombeyi, M. S.; Rollin, D.; Lankford, B.

    Water scarcity in semi-arid catchments presents challenges on achieving equitable sharing of available water resources and avoiding social tensions among small-holder farmers. This paper explores the implementation of a river basin game as a tool to facilitate negotiations and rules of equal access among upstream and downstream irrigation water users in Ga-Sekororo, Olifants river basin in South Africa. The various stages of the game playing methodology are presented in a progressive manner and the outcomes are discussed. Through the application of this game, farmers were able to better relate to their catchment and accepted the board’s schematic representation of their reality. They were able to understand top-tail inequities of water supply and to appreciate that solutions lie in the community. The coming together of the small-holder farmers to share knowledge and set agreements on equitable water sharing results in higher benefits such as community harmony, transparency, acceptance of operating rules and improved knowledge to the community as a whole. The collective negotiation exercise produces more acceptable water allocation rules, thereby improving the security of water supply to the irrigation schemes. The paper concludes that local level management of tensions and conflicts through participation as facilitated by the river basin games can be sustainable provided there is proactive support from higher level institutions such as water committees, government and research.

  10. 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...

  11. Effect of laundry activities on in-stream concentrations of linear alkylbenzene sulfonate in a small rural South African river.

    Science.gov (United States)

    Gordon, A K; Muller, W J; Gysman, N; Marshall, S J; Sparham, C J; O'Connor, S M; Whelan, M J

    2009-07-15

    In many parts of the world clothes are washed near to or in rivers and streams. Little information is available on resulting concentrations of detergent ingredients or on any potential effects caused. In this study, the fate of a commonly used anionic surfactant, linear alkylbenzene sulphonate (LAS) was investigated in a reach of the Balfour River (Eastern Cape Province, South Africa) which was regularly used as a site for laundry activity. Samples of river water were collected upstream of the main washing site and at a number of locations downstream on several occasions in winter and summer. Sediment samples were also collected and analysed. In addition, a household survey was conducted to ascertain the amount of detergent used and the distribution of washing practices. The results of the survey suggested that the use of riverside locations for laundry activities was seasonal. Most washing tended to be done at home during the winter with riverside sites used more frequently during the summer months. The monitoring data showed that LAS concentrations in water were very variable. They were occasionally high in the immediate vicinity of the laundry site (up to 342 microg L(-1)) but were generally very low (effects are expected from LAS emissions at this site.

  12. The Use of Oral Histories to Identify Criteria for Future Scenarios of Sustainable Farming in the South Yangtze River, China

    Directory of Open Access Journals (Sweden)

    Pingyang Liu

    2016-08-01

    Full Text Available Agricultural practices in Jiangnan water towns have historically been identified as maintaining a balance between human activity and the local environment, but are now a significant local source of water pollution. Using a multi-methods approach, this study deduces the environmental impact of traditional practices, and the socially desired conditions for successfully reintroducing critical ones. Oral histories from 31 farmers in Tianshanzhuang village, South Yangtze River were in order to chart changes in farming practices over four historic periods, and used to estimate the nitrogen and phosphorus burdens per acre. Findings show that the use of Lan River Mud—dredged mud for fertilizer—was key in producing a positive impact, but abandoned after the 1980s. Four criteria hindering reintroduction of traditional practices were identified, and potentially useful but fragmented emerging local candidate practices are considered against these, as are recent practices in Japan. We propose that the cooperation of several stakeholders with various related government departments in China could lead to a portfolio of effective policy changes and should be studied further: to include new methods and uses of Lan River Mud; the integration of aquaculture, leisure and tourism industries with agriculture; and the production of organic produce with well-planned internet-linked sales, delivery and coordination mechanisms.

  13. Dioxin contamination in Sampit River: Winyah Bay system, Georgetown County South Carolina

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Double-crested cormorants feeding in the Sampit River below the International Paperr co. discharge were collected for dioxin analyses. Whole body samples were...

  14. Neogene uplift of south Western Australia as constrained by river profiles

    CERN Document Server

    Barnett-Moore, Nicholas; Flament, Nicolas; Butterworth, Nathaniel; Müller, R Dietmar

    2013-01-01

    The relative tectonic quiescence of the Australian continent during the Cenozoicmakes it an excellent natural laboratory to study recent large-scale variations insurface topography and the processes influencing these changes. A part of this landscape is a fluvial network that is sensitive to variations in landscape horizontaland vertical motions. The notion that a river acts as a "tape recorder" for vertical perturbations (Pritchard et al., 2009) suggests that one can deduce changes in spatial and temporal characteristics of uplift via the analysis of river "channel-parallel", or longitudinal, profiles. Here we analysed 21 longitudinal river profiles, around the Australian continent. Steady-state concave upward profiles in northeast Australia indicate an absence of recent uplift. In contrast, pronounced convex upward undulations and major knickpoints within longitudinal profiles of rivers in southwest Australia suggest recent landscape uplift. This requires an explanation given the lackof recent, large-scale ...

  15. 2010 UMRS Color Infrared Aerial Photo Mosaic - Mississippi River, Pool 13 South

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Upper Mississippi River Restoration-Environmental Management Program (UMRR-EMP) partnered with the U.S. Fish and Wildlife Service (USFWS) Region 3 to collect...

  16. 2010 UMRS Color Infrared Aerial Photo Mosaic - Mississippi River, Pool 4 South

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Upper Mississippi River Restoration-Environmental Management Program (UMRR-EMP) partnered with the U.S. Fish and Wildlife Service (USFWS) Region 3 to collect...

  17. 2010 UMRS Color Infrared Aerial Photo Mosaic - Illinois River, LaGrange Pool South

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Upper Mississippi River Restoration-Environmental Management Program (UMRR-EMP) partnered with the U.S. Fish and Wildlife Service (USFWS) Region 3 to collect...

  18. Aquifer Boundary of the Wood River Valley Aquifer System, South-Central Idaho

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset contains the boundary of the Wood River Valley aquifer system as modified and expanded from that defined by Skinner and others (2007): It has been...

  19. Estimated Thickness of Quaternary Sediment in the Wood River Valley aquifer system, South-Central Idaho

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset is the estimated thickness of Quaternary sediment of the Wood River Valley aquifer system. This isopach map was constructed by subtracting the estimated...

  20. River flow response to changes in vegetation cover in a South ...

    African Journals Online (AJOL)

    2008-07-23

    Jul 23, 2008 ... may be accomplished using a remotely sensed spectral vegetation index. .... Daily river flow data were obtained from the DWAF using their on-line ..... streamflow of clearing invasive pine and wattle trees from a riparian zone.

  1. Study area boundary for unconfined aquifer analysis, Wood River Valley, South-Central Idaho

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The entire population of the Wood River Valley depends on ground water for domestic supply, either from domestic or municipal-supply wells, rapid population growth...

  2. The dog originated south of Yangtse river less than 16,000 years ago, from numerous wolves

    Energy Technology Data Exchange (ETDEWEB)

    Leitner, Thomas [Los Alamos National Laboratory; Pang, Jun - Feng [STATE KEY LABORATORY OF GENETIC; Kluetsch, Cornelya [KTH-ROYAL INST. OF TECH

    2009-01-01

    We here present a detailed picture of the origins of the dog, giving strong and precise evidence for 'where and when', and thereby also a first tentative picture of 'how, why and by whom' the wolf was domesticated. Previous studies of mitochondrial DNA (mtDNA) have failed to definitely establish the time and place of origin because of lack in phylogenetic resolution for the so far studied 582 bp region, and inadequate sampling across the world. We therefore analysed 169 mtDNA genomes, selected from partial sequences (582 bp) from 1,576 dogs worldwide. This shows that dogs universally share a common gene pool, but the three earlier identified universally occurring phylogenetic clades ofhigh age consist often much younger subclades, which originated 5,000-16,000 ya from at least 48 wolf founders. The full range of genetic diversity, all 10 subclades, is found only in south-eastern Asia south of Yangtze River, and the diversity decreases gradually across Eurasia down to only four sub clades in Europe. This establishes that the dog has a single origin in time and space from a large number ofwolves, less than 16,000 ya, probably in China south of Y angtzeRiver. The place and time coincide with the origin of rice agriculture, suggesting an origin among sedentary hunter-gatherers or early rice farmers. The numerous founders indicate that wolf taming was an important cultural trait, and it is noticeable that in this region dogs are since ancient times used as food, offering a possible reason for the wolf domestication.

  3. Origin of groundwater salinity in the Sandspruit catchment, Berg River basin (South Africa)

    CSIR Research Space (South Africa)

    Demlie, M

    2011-09-01

    Full Text Available of the Berg River, Klipplaat and Moorreesburg Formations, which together constitute the Swartland Subgroup (Gresse et al. 2006). The Berg River Formation is composed of chlorite schist, greywacke with impure limestone lenses and quartz schist towards the top.... The contact with the overlying Klipplaat Formation is placed just above a strongly deformed, ferruginous, cherty quartzite or the uppermost limestone layer. The Klipplaat Formation is essentially quartz schist, consisting of quartz, Seri cite and chlorite...

  4. Management of human-induced salinization in the Berg River catchment (South Africa)

    CSIR Research Space (South Africa)

    Jovanovic, Nebojsa

    2010-09-01

    Full Text Available of different crop rotations 2) Goedertrou small scale catchment: hydrosalinity fluxes 3) Voelvlei Nature Reserve: evapotranspiration of endemic renosterveld vegetation and adjacent wheat field The results obtained from the intensive monitoring sites served... with different crop rotations Goedertrou 20 ha catchment Endemic renosterveld at Voelvlei Nature Reserve Sandspruit river Berg river Figure 4: Relationship between mean annual precipitation and groundwater salinity (electrical conductivity EC class...

  5. The geochemistry characteristic and dating of cold seepage carbonates of the Pearl River Mouth Basin, eastern of South China Sea

    Science.gov (United States)

    Fang, Yunxin; Fu, Shaoying

    2015-04-01

    Cold seepage carbonates are usually formed by the interaction of methane oxidizing archaea, sulfate reducing bacteria and cold seepage which contain abundant venting hydrocarbon gases. The presence of cold seepage carbonates on the seabed is one of the evidences that the area exist venting hydrocarbon gases, which are usually result by the dissociation of gas hydrate. The cold seepage property and fluid flow rate can influence the oxidation-deoxidation environment of the bottom water and sediment. Many previous studies focused on the mineral composition, microstructure, elemental composition, isotope composition of the cold seepage carbonates and isotopic dating for the cold seepage carbonates. The isotopic dating for the cold seepage carbonates can provide the information of the gas hydrate formation and dissociation in some area of the South China Sea. High precision TIMS-U dating and 14C dating are used as routine method for the dating of the Quaternary carbonates and fossils. The cold seepage carbonates in the study include the samples collected by ROV on the seabed and the drilling for gas hydrate in the Pearl River Mouth Basin, eastern of the South China Sea. The authigenic carbonate occurred in different depth in the A, B and C drilling site. They may be represent different events of gas hydrate formation and dissociation in the Quaternary. The dating study for all the cold seepage carbonates can provide the relative accurate eras of the gas hydrate dissociation events in certain area of the South China Sea.

  6. Freshwater gastropods diversity hotspots: three new species from the Uruguay River (South America)

    Science.gov (United States)

    de Lucía, Micaela

    2016-01-01

    Background: The Atlantic Forest is globally one of the priority ecoregions for biodiversity conservation. In Argentina, it is represented by the Paranense Forest, which covers a vast area of Misiones Province between the Paraná and Uruguay rivers. The Uruguay River is a global hotspot of freshwater gastropod diversity, here mainly represented by Tateidae (genus Potamolithus) and to a lesser extent Chilinidae. The family Chilinidae (Gastropoda, Hygrophila) includes 21 species currently recorded in Argentina, and three species in the Uruguay River. The species of Chilinidae occur in quite different types of habitats, but generally in clean oxygenated water recording variable temperature ranges. Highly oxygenated freshwater environments (waterfalls and rapids) are the most vulnerable continental environments. We provide here novel information on three new species of Chilinidae from environments containing waterfalls and rapids in the Uruguay River malacological province of Argentina. Materials and Methods: The specimens were collected in 2010. We analyzed shell, radula, and nervous and reproductive systems, and determined the molecular genetics. The genetic distance was calculated for two mitochondrial markers (cytochrome c oxidase subunit I–COI- and cytochrome b -Cyt b-) for these three new species and the species recorded from the Misionerean, Uruguay River and Lower Paraná-Río de la Plata malacological provinces. In addition, the COI data were analyzed phylogenetically by the neighbor-joining and Bayesian inference techniques. Results: The species described here are different in terms of shell, radula and nervous and reproductive systems, mostly based on the sculpture of the penis sheath. Phylogenetic analyses grouped the three new species with those present in the Lower Paraná-Río de la Plata and Uruguay River malacological provinces. Discussion: Phylogenetic analyses confirm the separation between the Uruguay River and the Misionerean malacological

  7. Heavy metals in oysters, mussels and clams collected from coastal sites along the Pearl River Delta, South China

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Concentrations of 8 heavy metals: cadmium (Cd), copper(Cu), zinc (Zn), lead (Pb), nickel (Ni), chromium (Cr), antimony(Sb) and tin (Sn) were examined in 3 species of bivalves (Pernaviridis, Crassostrea rivularis and Ruditapes philippinarum)collected from 25 sites along the Pearl River Delta coastal watersin the South China Sea from July to August 1996. In general, Cd,Cu, Zn and Sn concentrations in the three bivalve species collectedfrom the Estuarine Zone were significantly higher than thosecollected from the Western and Eastern Zones of the Pearl RiverDelta, which are related to the existence of various anthropogenicactivities in the catchment of the Pearl River Delta. The WesternEstuarine Zone is mainly impacted by Cr, Ni and Cu contamination.In Victoria Harbor, heavy metal contamination is mainly due to Cuand Pb. Cd, Cu and Zn concentrations in oysters were significantlyhigher than those in mussels and clams. This could be explained bythe fact that oysters live mainly in the Estuarine Zone of thePearl River Delta which receives most of the polluting dischargesfrom the catchment of the Delta. During turbid condition, heavymetals (soluble or adsorbed on suspended particulates) dischargedfrom the Delta are filtered from the water column and subsequentlyaccumulated into the soft body tissues of oysters. Heavy metalconcentrations in the three bivalve species were compared with themaximum permissible levels of heavy metals in seafood regulated bythe Public Health and Municipal Services Ordinance, Laws of HongKong, and it was revealed that Cd and Cr concentrations in thethree bivalve species exceeded the upper limits. At certainhotspots in the Delta, the maximum acceptable daily load for Cd wasalso exceeded.

  8. River-groundwater connectivity in a karst system, Wellington, New South Wales, Australia

    Science.gov (United States)

    Keshavarzi, Mohammadreza; Baker, Andy; Kelly, Bryce F. J.; Andersen, Martin S.

    2017-03-01

    The characterization of river-aquifer connectivity in karst environments is difficult due to the presence of conduits and caves. This work demonstrates how geophysical imaging combined with hydrogeological data can improve the conceptualization of surface-water and groundwater interactions in karst terrains. The objective of this study is to understand the association between the Bell River and karst-alluvial aquifer at Wellington, Australia. River and groundwater levels were continuously monitored, and electrical resistivity imaging and water quality surveys conducted. Two-dimensional resistivity imaging mapped the transition between the alluvium and karst. This is important for highlighting the proximity of the saturated alluvial sediments to the water-filled caves and conduits. In the unsaturated zone the resistivity imaging differentiated between air- and sediment-filled karst features, and in the saturated zone it mapped the location of possible water- and sediment-filled caves. Groundwater levels are dynamic and respond quickly to changes in the river stage, implying that there is a strong hydraulic connection, and that the river is losing and recharging the adjacent aquifer. Groundwater extractions (1,370 ML, megalitres, annually) from the alluvial aquifer can cause the groundwater level to fall by as much as 1.5 m in a year. However, when the Bell River flows after significant rainfall in the upper catchment, river-leakage rapidly recharges the alluvial and karst aquifers. This work demonstrates that in complex hydrogeological settings, the combined use of geophysical imaging, hydrograph analysis and geochemical measurements provide insights on the local karst hydrology and groundwater processes, which will enable better water-resource and karst management.

  9. River-groundwater connectivity in a karst system, Wellington, New South Wales, Australia

    Science.gov (United States)

    Keshavarzi, Mohammadreza; Baker, Andy; Kelly, Bryce F. J.; Andersen, Martin S.

    2016-12-01

    The characterization of river-aquifer connectivity in karst environments is difficult due to the presence of conduits and caves. This work demonstrates how geophysical imaging combined with hydrogeological data can improve the conceptualization of surface-water and groundwater interactions in karst terrains. The objective of this study is to understand the association between the Bell River and karst-alluvial aquifer at Wellington, Australia. River and groundwater levels were continuously monitored, and electrical resistivity imaging and water quality surveys conducted. Two-dimensional resistivity imaging mapped the transition between the alluvium and karst. This is important for highlighting the proximity of the saturated alluvial sediments to the water-filled caves and conduits. In the unsaturated zone the resistivity imaging differentiated between air- and sediment-filled karst features, and in the saturated zone it mapped the location of possible water- and sediment-filled caves. Groundwater levels are dynamic and respond quickly to changes in the river stage, implying that there is a strong hydraulic connection, and that the river is losing and recharging the adjacent aquifer. Groundwater extractions (1,370 ML, megalitres, annually) from the alluvial aquifer can cause the groundwater level to fall by as much as 1.5 m in a year. However, when the Bell River flows after significant rainfall in the upper catchment, river-leakage rapidly recharges the alluvial and karst aquifers. This work demonstrates that in complex hydrogeological settings, the combined use of geophysical imaging, hydrograph analysis and geochemical measurements provide insights on the local karst hydrology and groundwater processes, which will enable better water-resource and karst management.

  10. In vitro screening for endocrine disruptive activity in selected South African harbours and river mouths

    CSIR Research Space (South Africa)

    Truter, JC

    2015-12-01

    Full Text Available Various waterborne anthropogenic contaminants disrupt the endocrine systems of wildlife and humans, targeting reproductive pathways, among others. Very little is known, however, regarding the occurrence of endocrine disruptive activity in South...

  11. Governance and politics in the upper Limpopo River Basin, South Africa

    CSIR Research Space (South Africa)

    Meissner, Richard

    2015-10-01

    Full Text Available Everyday international political economy (EIPE) offers an opportunity to rethink the role of individuals and citizenry in shaping governance of natural resources. In South Africa, significant progress has been made by government in re-shaping water...

  12. Aquatic biological communities and associated habitats at selected sites in the Big Wood River Watershed, south-central Idaho, 2014

    Science.gov (United States)

    MacCoy, Dorene E.; Short, Terry M.

    2016-09-28

    Assessments of streamflow (discharge) parameters, water quality, physical habitat, and biological communities were completed between May and September 2014 as part of a monitoring program in the Big Wood River watershed of south-central Idaho. The sampling was conducted by the U.S. Geological Survey in cooperation with Blaine County, Trout Unlimited, the Nature Conservancy, and the Wood River Land Trust to help identify the status of aquatic resources at selected locations in the watershed. Information in this report provides a basis with which to evaluate and monitor the long-term health of the Big Wood River and its major tributaries. Sampling sites were co-located with existing U.S. Geological Survey streamgaging stations: three on the main stem Big Wood River and four on the North Fork Big Wood River (North Fork), Warm Springs Creek (Warm Sp), Trail Creek (Trail Ck), and East Fork Big Wood River (East Fork) tributaries.The analytical results and quality-assurance information for water quality, physical habitat, and biological community samples collected at study sites during 2 weeks in September 2014 are summarized. Water-quality data include concentrations of major nutrients, suspended sediment, dissolved oxygen, and fecal-coliform bacteria. To assess the potential effects of nutrient enrichment on algal growth, concentrations of periphyton biomass (chlorophyll-a and ash free dry weight) in riffle habitats were determined at each site. Physical habitat parameters include stream channel morphology, habitat volume, instream structure, substrate composition, and riparian vegetative cover. Biological data include taxa richness, abundance, and stream-health indicator metrics for macroinvertebrate and fish communities. Statistical summaries of the water-quality, habitat, and biological data are provided along with discussion of how these findings relate to the health of aquatic resources in the Big Wood River watershed.Seasonal discharge patterns using statistical

  13. Quantifying potential water savings from clearing invasive alien Eucalyptus camaldulensis using in situ and high resolution remote sensing data in the Berg River Catchment, Western Cape, South Africa

    CSIR Research Space (South Africa)

    Dzikiti, Sebinasi

    2016-02-01

    Full Text Available , to provide an indication of the impacts of clearing on streamflow under Mediterranean climatic conditions. The study was conducted at two adjacent sites in the Berg River catchment, Western Cape Province in South Africa. One site was densely invaded by E...

  14. On the ecology of the fauna of stones in the current in a South African river supporting a very large simulium (Diptera) population

    CSIR Research Space (South Africa)

    Chutter, FM

    1968-12-01

    Full Text Available There is a large population of Simulium chutteri lewis in the Vaal river at and below the village of Warrenton in the north-east of the Cape Province, South Africa. The female of this species attacks man, cattle and horses and had become a pest when...

  15. Instructional Supervisory Practices and Teachers' Role Effectiveness in Public Secondary Schools in Calabar South Local Government Area of Cross River State, Nigeria

    Science.gov (United States)

    Sule, Mary Anike; Eyiene, Ameh; Egbai, Mercy E.

    2015-01-01

    The study investigated the relationship between instructional supervisory practices and teachers' role effectiveness in public secondary schools in Calabar South Local Government Area of Cross River State. Two null hypotheses were formulated to guide the study. Ex-post facto research design was adopted for the study. The population of the study…

  16. Will tree euphorbias (Euphorbia tetragona and Euphorbia triangularis) survive under the impact of black rhinoceros (Bicornis diceros minor) browsing in the Great Fish River Reserve, South Africa?

    NARCIS (Netherlands)

    Heilmann, L.C.; Jong, de K.; Lent, P.C.; Boer, de W.F.

    2006-01-01

    The impact of black rhinoceros (Bicornis diceros minor) on the tree euphorbias Euphorbia tetragona and Euphorbia triangularis was studied in the Great Fish River Reserve, South Africa. Black rhinoceros pushed over about 5¿7% of the trees in a 2-month period. There was a preference of rhinos for smal

  17. Invasive alien plants and South African rivers: a proposed approach to the prioritisation of control operations

    CSIR Research Space (South Africa)

    Van Wilgen, BW

    2007-01-01

    Full Text Available . (1991) Rapid invasion of Fraxinus ornus L. along the Herault River system in southern France: the importance of seed dispersal by water. Journal of Biogeography, 18, 7–12. Tinley K.L. (1991) Towards harmony with the land: the drainage basin... riparian zones to be more invaded by alien species than other plant communities, and rivers may function as dispersal corridors for the rapid spread of invasive alien plants across landscapes (The´baud & Debussche, 1991; Pyseˇk & Prach, 1994; Planty...

  18. Mercury bioaccumulation in fish in a region affected by historic gold mining; the South Yuba River, Deer Creek, and Bear River watersheds, California, 1999

    Science.gov (United States)

    May, Jason T.; Hothem, Roger L.; Alpers, Charles N.; Law, Matthew A.

    2000-01-01

    Mercury that was used historically for gold recovery in mining areas of the Sierra Nevada continues to enter local and downstream water bodies, including the Sacramento Delta and the San Francisco Bay of northern California. Methylmercury is of particular concern because it is the most prevalent form of mercury in fish and is a potent neurotoxin that bioaccumulates at successive trophic levels within food webs. In April 1999, the U.S. Geological Survey, in cooperation with several other agencies the Forest Service (U.S. Department of Agriculture), the Bureau of Land Management, the U.S. Environmental Protection Agency, the California State Water Resources Control Board, and the Nevada County Resource Conservation District began a pilot investigation to characterize the occurrence and distribution of mercury in water, sediment, and biota in the South Yuba River, Deer Creek, and Bear River watersheds of California. Biological samples consisted of semi-aquatic and aquatic insects, amphibians, bird eggs, and fish. Fish were collected from 5 reservoirs and 14 stream sites during August through October 1999 to assess the distribution of mercury in these watersheds. Fish that were collected from reservoirs included top trophic level predators (black basses, Micropterus spp.) intermediate trophic level predators [sunfish (blue gill, Lepomis macrochirus; green sunfish, Lepomis cyanellus; and black crappie, Poxomis nigromaculatus)] and benthic omnivores (channel catfish, Ictularus punctatus). At stream sites, the species collected were upper trophic level salmonids (brown trout, Salmo trutta) and upper-to-intermediate trophic level salmonids (rainbow trout, Oncorhynchus mykiss). Boneless and skinless fillet portions from 161 fish were analyzed for total mercury; 131 samples were individual fish, and the remaining 30 fish were combined into 10 composite samples of three fish each of the same species and size class. Mercury concentrations in samples of black basses

  19. The dangers of taking mud for granted: Lessons from Lower Old Red Sandstone dryland river systems of South Wales

    Science.gov (United States)

    Wright, V. Paul; Marriott, Susan B.

    2007-02-01

    Mudrocks are a prominent feature of many ancient dryland successions but they are not always a product of the settling out of suspension load. From studies of the late Silurian-early Devonian Old Red Sandstone mudrocks of South Wales it has been shown that many were not overbank sediments deposited from suspension on floodplains, but were emplaced as sand- and silt-sized aggregates transported as bed load and deposited in sinuous channels and as braid-bar complexes on multi-stage floodplains in dryland river systems. Using the Old Red Sandstone examples criteria are provided for the recognition of similar deposits in the sedimentary record. One important aspect of these mudrocks is that they can represent multiple recycling events and can constitute condensed deposits that may be characteristic of closed alluvial basins with periodically limited sediment supply.

  20. Vertical Migration of Petroleum via Faults in Zhu Ⅲ Subbasin, Pearl River Mouth Basin, South China Sea

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The problem that faults act as a conduit for hydrocarbon-bearing fluid flow has been under debate for a long time. The southern boundary fault (FS) and No.2 fault belt in the Zhu Ⅲ subbasin in the Pearl River Mouth basin (PRMB) of South China Sea (SCS) are considered as the conduit of hydrocarbons for the oil and gas fields in the hydrocarbon-generating half grabens. Based upon the basin modeling and seismic velocity inversion simulation, there are abnormal-pressure compartments in the central part of half grabens. Wenchang, Enping and Zhuhai FormationⅡare seated within the abnormal-pressure zone, while the Zhuhai Formation Ⅰ is within the pressure-transition zone. The abnormal pressure was mainly caused by undercompaction due to the high rate of sedimentation for layers with an abnormal pressure. The increase of temperature of inclusions as the increase of depth supports vertical migration via faults in the study area.

  1. Vegetation establishment success in restored carolina bay depressions on the Savannah River Site, South Carolina - phase one.

    Energy Technology Data Exchange (ETDEWEB)

    Sharitz, Rebecca, A.; Mulhouse, John, M.

    2004-05-01

    Successful wetlands restoration must re-establish or enhance three parameters: wetland hydrology, hydric soils, and hydrophytic vegetation (Mitsch and Gosselink 2000). On the Savannah River Site, South Carolina, restoration of small Carolina bay depression-wetlands was initiated in FY 2001 to provide wetland acreage for mitigation banking (US DOE 1997). Sixteen small depressions that had historically been drained for agricultural purposes were selected for restoration, and an additional four were initially chosen to serve as non-restored controls. Restoration treatments included plugging the existing ditches to increase water volume retention and wetland hydroperiod and clear-cutting removal of woody vegetation in the interiors. Planned endpoints of the restoration were herbaceous meadow and forested savanna bay interiors, and pine savanna and pine/hardwood forested bay margins (Barton and Singer 2001). To promote forested savanna interiors, saplings of bald cypress and swamp tupelo were planted following removal of the woody species.

  2. Environmental health outcomes and exposure risks among at-risk communities living in the Upper Olifants River Catchment, South Africa.

    Science.gov (United States)

    John, Juanette; Wright, Caradee Yael; Oosthuizen, Maria Aletta; Steyn, Maronel; Genthe, Bettina; le Roux, Wouter; Albers, Patricia; Oberholster, Paul; Pauw, Christiaan

    2014-01-01

    Potential exposure to water and air pollution and associated health impacts of three low-income communities in the Upper Olifants River Catchment, South Africa, was investigated through a cross-sectional epidemiological study comprising a household survey. Water samples were collected and analysed for microbial indicators and pathogens. Ambient air-monitoring included some of the criteria pollutants, as well as mercury and manganese. Associations between environmental exposure and health outcomes were analysed by means of logistic regression. Despite poor water and air quality episodes, the communities' self-perceived health was good with relatively low prevalence of reported health outcomes. Hygiene practices with respect to water collection and storage were often poor, and most likely contributed to the regularly contaminated water storage containers. Community proximity to the polluted stream was associated with increased prevalence in adverse health outcomes. This paper reports on preliminary results and additional multivariate analyses are necessary to further understand study results.

  3. Development of CE-QUAL-W2 models for the Middle Fork Willamette and South Santiam Rivers, Oregon

    Science.gov (United States)

    Buccola, Norman L.; Stonewall, Adam J.; Sullivan, Annett B.; Kim, Yoonhee; Rounds, Stewart A.

    2013-01-01

    Hydrodynamic (CE-QUAL-W2) models of Hills Creek Lake (HCL), Lookout Point Lake (LOP), and Dexter Lake (DEX) on the Middle Fork Willamette River (MFWR), and models of Green Peter Lake and Foster Lake on the South Santiam River systems in western Oregon were updated and recalibrated for a wide range of flow and meteorological conditions. These CE-QUAL-W2 models originally were developed by West Consultants, Inc., for the U.S. Army Corps of Engineers. This study by the U.S. Geological Survey included a reassessment of the models’ calibration in more recent years—2002, 2006, 2008, and 2011—categorized respectively as low, normal, high, and extremely high flow calendar years. These years incorporated current dam-operation practices and more available data than the time period used in the original calibration. Modeled water temperatures downstream of both HCL and LOP-DEX on the MFWR were within an average of 0.68 degree Celsius (°C) of measured values; modeled temperatures downstream of Foster Dam on the South Santiam River were within an average of 0.65°C of measured values. A new CE-QUAL-W2 model was developed and calibrated for the riverine MFWR reach between Hills Creek Dam and the head of LOP, allowing an evaluation of the flow and temperature conditions in the entire MFWR system from HCL to Dexter Dam. The complex bathymetry and long residence time of HCL, combined with the relatively deep location of the power and regulating outlet structures at Hills Creek Dam, led to a HCL model that was highly sensitive to several outlet and geometric parameters related to dam structures (STR TOP, STR BOT, STR WIDTH). Release temperatures from HCL were important and often persisted downstream as they were incorporated in the MFWR model and the LOP-DEX model (downstream of MFWR). The models tended to underpredict the measured temperature of water releases from Dexter Dam during the late-September-through-December drawdown period in 2002, and again (to a lesser extent) in

  4. Bioaccumulation and risk assessment of per- and polyfluoroalkyl substances in wild freshwater fish from rivers in the Pearl River Delta region, South China.

    Science.gov (United States)

    Pan, Chang-Gui; Zhao, Jian-Liang; Liu, You-Sheng; Zhang, Qian-Qian; Chen, Zhi-Feng; Lai, Hua-Jie; Peng, Feng-Jiao; Liu, Shuang-Shuang; Ying, Guang-Guo

    2014-09-01

    Per- and polyfluoroalkyl substances (PFASs) are used in various industries, which results in their ubiquitous occurrence in the environment. This study determined the concentrations of eighteen PFASs in muscle and liver of nine wild freshwater fish species collected from rivers in the Pearl River Delta (PRD) region, South China, and assessed their bioaccumulation and potential health risks to local people. The results showed that eight and twelve PFASs were detected in the fish muscle and liver samples, respectively. Perfluorooctane sulfonate (PFOS) was found to be the predominant PFAS both in muscle and liver with its highest concentrations of 79ng/g wet weight (ww) in muscle and 1500ng/g ww in liver, followed by Perfluoroundecanoic acid (PFUnDA) and Perfluorotridecanoic acid (PFTrDA) with trace concentrations. The mean PFOS concentrations in fish muscle and liver tissues of the nine collected species ranged from 0.40ng/g in mud carp to 25ng/g in snakehead, and from 5.6ng/g in mud carp to 1100ng/g in snakehead, respectively. Significant positive correlations were found among PFASs both in water and fish, indicating a similar pollution source for these PFASs. In tilapia samples, PFOS concentrations showed an increasing trend with increasing length and weight, but no significant difference between genders. Bioaccumulation factors (logBAF) in fish for the PFASs were in the range from 2.1 to 5.0. The calculated hazard ratios (HR) of PFOS for all fishes were in the range of 0.05-2.8, with four out of nine species (tilapia, chub, leather catfish and snakehead) having their HR values more than 1.0. The results suggest that frequent consumption of these four fish species may pose health risks to local population.

  5. Ecological Reserve: Towards a common understanding for river management in South Africa

    CSIR Research Space (South Africa)

    Van Wyk, E

    2006-07-01

    Full Text Available for by the Ecological Reserve) can in this way be brought into debate in a way that promotes wider appreciation of society’s diverse uses of river resources. In doing so it promotes interest-based participation as intended by legislation....

  6. The Bot River, a closed estuary in the south-western Cape

    African Journals Online (AJOL)

    The salinity at the time of survey ranged from 7 - 1il/00, ... The Bot River vlei is a large, closed estuary situated between ... zooplankton as well as temperature and oxygen fluctuations ... Benthic invertebrates were sampled from a series of five.

  7. Freshwater bivalve mollusca (unionidae, sphaeriidae, corbiculidae) of the Savannah River Plant, South Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Britton, J.C.; Fuller, S.L.H.

    1980-11-01

    A guide to freshwater bivalve molluscs found at the Savannah River Plant is presented. A dichotomous taxonomic key is provided to common forms and to unreported species whose geographic distributions include nearby localities. Discussions of ecology, life history, larval hosts, and other pertinent information is provided. (ACR)

  8. Intensity distribution and effect of the Nov. 9, 1996 earthquake of MS=6.1 in offshore outside the Yangtze River Mouth on the South Korea

    Institute of Scientific and Technical Information of China (English)

    李裕澈; 李德基; 吴锡薰; 尹龙勋

    2003-01-01

    @@ On Nov. 9, 1996 at 21h56min (Beijing Time), an earthquake of MS=6.1 occurred in offshore outside the Yangtze River Mouth (31o43¢N, 123o04¢E). The shock affected Shanghai City and both Jiangsu and Zhejiang Provinces in China mainly. The shock was felt more strongly in the Yangtze River Mouth and Hangzhou Bay area than in the rest of them, particularly in high buildings of Shanghai City. In addition, the earthquake was felt in South Korea and also stronger in apartments or high buildings. LIU, JIN (1998) and LIU, et al (1999) described effect of the shock on the eastern China. The paper describes the effect of the earthquake on South Korea and the whole intensity distribution in South Korea and eastern China.

  9. Impacts of ENSO on multi-scale variations in sediment discharge from the Pearl River to the South China Sea

    Science.gov (United States)

    Liu, Feng; Chen, Hui; Cai, Huayang; Luo, Xiangxin; Ou, Suying; Yang, Qingshu

    2017-09-01

    Sediment load delivered by rivers is an important terrestrial factor in the evolution and productivity of coastal ecosystems and coastal morphology. As the strongest interannual climate signal, the El Niño Southern Oscillation (ENSO) is closely related to variations in the hydrological cycle at global and regional scales. However, the influence of ENSO on temporal variations in sediment discharge is poorly understood. In this paper, we examine periodic variations in sediment discharge to the South China Sea from the Pearl River since the 1950s using wavelet transform analysis (WT). Furthermore, we apply cross wavelet spectrum (XWT) and wavelet coherence (WTC) to investigate the linkages between ENSO and sediment variability. The WT results revealed that periodic oscillations in sediment discharge in the Pearl River occurred annually (1 yr) before the 2000s, interannually (2-8 yr) from 1960-2002, and decadally (10-16 yr) from 1975-1995. These periodic variations in the sediment load series had common spectrum power with the water discharge and precipitation series, indicating an important climatic control. The XWT and WTC results revealed significant impacts of ENSO on precipitation, water discharge and sediment load at interannual time scales of 2-4.6 yr from 1960-2002 with a shift of patterns of ENSO on sediment variability after the 1970s. In addition, an in-phase relation between sediment discharge and ENSO at time scales of 10-16 yr from 1975-1995 was detected, indicating that variations at decadal scales could be related to other climatic teleconnections such as the Pacific Decadal Oscillation. Compared with the spectrum structures of periodic variations in precipitation and water discharge and their relationship with ENSO, there was a loss of energy in the sediment load at annual time scales after 2002 that can be attributed to dam construction in the river basin. Our study provides perspectives on the connections between ENSO and sediment variability at

  10. Linking habitat quality with trophic performance of steelhead along forest gradients in the South Fork Trinity River Watershed, California

    Science.gov (United States)

    McCarthy, Sarah G.; Duda, Jeffrey J.; Emlen, John M.; Hodgson, Garth R.; Beauchamp, David A.

    2009-01-01

    We examined invertebrate prey, fish diet, and energy assimilation in relation to habitat variation for steelhead Oncorhynchus mykiss (anadromous rainbow trout) and rainbow trout in nine low-order tributaries of the South Fork Trinity River, northern California. These streams spanned a range of environmental conditions, which allowed us to use bioenergetics modeling to determine the relative effects of forest cover, stream temperature, season, and fish age on food consumption and growth efficiency. Evidence of seasonal shifts in reliance on aquatic versus terrestrial food sources was detected among forest cover categories and fish ages, although these categories were not robust indicators of O. mykiss condition and growth efficiency. Consumption estimates were generally less than 20% of maximum consumption, and fish lost weight in some streams during summer low-flow conditions when stream temperatures exceeded 15°C. Current 100-year climate change projections for California threaten to exacerbate negative growth patterns and may undermine the productivity of this steelhead population, which is currently not listed as endangered or threatened. To demonstrate the potential effect of global warming on fish growth, we ran three climate change scenarios in two representative streams. Simulated temperature increases ranging from 1.4°C to 5.5°C during the summer and from 1.5°C to 2.9C during the winter amplified the weight loss; estimated average growth for age-1 fish was 0.4–4.5 times lower than normal (low to high estimated temperature increase) in the warm stream and 0.05–0.8 times lower in the cool stream. We conclude that feeding rate and temperature during the summer currently limit the growth and productivity of steelhead and rainbow trout in low-order streams in the South Fork Trinity River basin and predict that climate change will have detrimental effects on steelhead growth as well as on macroinvertebrate communities and stream ecosystems in general.

  11. The influence of a river plume on the sea-ice meiofauna in south-eastern Hudson Bay

    Science.gov (United States)

    Grainger, E. H.

    1988-08-01

    Outflow from the Great Whale River produces a substantial freshwater layer (plume) beneath the winter ice cover and above water of higher salinity in south-eastern Hudson Bay. In 1983, samples of the lower-ice fauna and of zooplankton beneath the ice, were taken within, below and beyond the offshore reach of the plume. Nematodes accounted for the highest numbers (mean of 1956 1 1in the lower 3 cm of ice), and copepods, mainly Harpacticus and Halectinosoma with fewer Tisbe and Oithona, for the greatest biomass. All ice-inhabiting taxa were also found in the water below the ice, but many zooplankters occurring immediately beneath the ice did not form part of the ice fauna. No major qualitative differences were evident between the ice communities existing above the plume and offshore from it, but quantitative distinctions were readily apparent. Animals were consistently more concentrated (by 2-3 orders of magnitude) in the lower 3 cm of the ice than in the water immediately below, both over the plume and outside it. Except for the dominant rotifers in the plume, the concentration of zooplankton there was only 10% of that found in the surface water outside the plume. The river plume exerts a strong influence over the quantity of the fauna in the sea ice immediately above it. Changes in location and extent of the plume therefore may have an important effect on the food chain based in the sea ice.

  12. Demographics of the spawning aggregations of four catostomid species in the Savannah River, South Carolina and Georgia, USA

    Science.gov (United States)

    Grabowski, T.B.; Ratterman, N.L.; Isely, J.J.

    2008-01-01

    Differences in the life history strategies employed by otherwise ecologically similar species of a fish assemblage may be an important factor in the coexistence of these species and is an essential consideration in the conservation and management of these assemblages. We collected scales to determine age and growth of four species of the catostomid assemblage (northern hogsucker Hypentelium nigricans, spotted sucker Minytrema melanops, notchlip redhorse Moxostoma collapsum and robust redhorse Moxostoma robustum) of the Savannah River, Georgia-South Carolina in spring 2004 and 2005. Robust redhorse was the largest species; reaching sexual maturity at an older age and growing faster as a juvenile than the other species. Spotted sucker did not achieve the same size as robust redhorse, but reached sexual maturity at younger ages. Notchlip redhorse was intermediate between the abovementioned two species in age at maturity and size. Northern hogsucker was the smallest species of the assemblage and reached the sexual maturity at the age of three. Both robust redhorse and spotted sucker were sexually dimorphic in size-at-age. The range of life history strategies employed by Savannah River catostomids encompasses the range of life history strategies exhibited within the family as a whole. ?? 2007 Blackwell Munksgaard.

  13. Fish gills alterations as potential biomarkers of environmental quality in a eutrophized tropical river in south-eastern Brazil.

    Science.gov (United States)

    Nascimento, A A; Araújo, F G; Gomes, I D; Mendes, R M M; Sales, A

    2012-06-01

    Gill anomalies in three common fish species of different taxonomic order, habitat dwelling and feeding habits (one Characiformes, Oligosarcus hepsetus; one Siluriformes, Hypostomus auroguttatus; and one Perciformes, Geophagus brasiliensis) from a eutrophized tropical river in south-eastern in Brazil were compared. The aim of this study was to search for sentinel species that could be used as potential biomarkers of environmental quality. Most fish had gills with histological changes, namely epithelial lifting, interstitial oedema, leucocyte infiltration, hyperplasia of the epithelial cells, lamellar fusion, vasodilatation and necrosis. On the other hand, lamellar blood congestion and lamellar aneurysm, which are more serious and often irreversible changes, were recorded for the water column carnivorous O. hepsetus and, to a lesser extent, for the bottom-dwelling detritivorous H. auroguttatus. A histopathological alteration index (HAI) based on the occurrence and severity of gills anomalies indicated that O. hepsetus (mean score = 11.4) had significantly higher values (Kruskall-Wallis H(2,41) = 15.95, P = 0.0003) compared with G. brasiliensis (mean score = 7.0). Overall, the omnivorous G. brasiliensis had comparatively lesser occurrence of most gill anomalies compared with other two species, being less suitable as biomarker of environmental quality. In contrast, the water column-dweller O. hepsetus (water column) and the bottom-dweller H. auroguttatus had gills most susceptible to changes, making them more suitable for using as histological biomarkers of the environmental quality in entrophized tropical rivers.

  14. Investment-centred transitioning from agrarian-tourism economy to manufacturing in cross river state, south-eastern/south-south, Nigeria: A theoretical perspective and background

    Directory of Open Access Journals (Sweden)

    Ingwe Richard

    2014-01-01

    Full Text Available Embattled by ministries, departments and agencies of Nigeria’s federal government, that worked together with neighbouring (Akwa Ibom State government to remove Cross River State from the country’s oil-producing states entitled to receipt of larger statutory allocations compared to their counterparts, Cross River State Government’s policy of promoting regional development through attraction of foreign direct investment (FDI since 2009 is receiving praises. This article presents contexts, core-periphery theoretical perspectives, and comments elucidating intricacies of FDI-centred sub-national regional development strategizing in the context of phenomenal globalization of neoliberal capitalism. It is argued that the core-periphery theory’s current status promises ‘depressed’ sub-national regions the development strategies they require for transiting from backwardness to growth. This assertion derives from the theory’s encouragement of Nigeria’s ‘depressed’ sub-national regions to aspire towards applying innovative policies/instruments capable of reversing undesirable circumstances that sometimes surpass standards previously/currently attained by counterparts placed higher on the development ladder.

  15. 226Ra and 210Po concentration in drinking water of Cauvery river basin south interior Karnataka State, India

    Directory of Open Access Journals (Sweden)

    E. Kavitha

    2017-01-01

    Full Text Available Naturally occurring radionuclide 210Po which is an element of 238U decay series, contribute to the radiation that normally people are exposed. Drinking water samples collected from Cauvery river basin of south interior Karnataka State, India were analysed for the activity of 210Po using radiochemical analysis technique. The estimated concentration of 210Po in river water ranges from 0.86 to 4.49 mBq l−1, and its mean value is 2.67 ± 1.09 mBq l−1. The concentration of 210Po in bore well water ranges from 1.89 to 4.18 mBq l−1 and its mean value is 3.22 ± 0.67 mBq l−1. The dissolved radium concentration in river water varies from 9.09 mBq l−1 to 55.07 mBq l−1 with an average of 32.33 ± 14.16 mBq l−1. Total ingestion dose rate due to 226Ra and 210Po varies from 2.61 to 15.00 μSv y−1 with a mean value of 8.95 ± 3.74 μSv y−1, which is less than the recommended value by ICRP (International commission on radiological protection.

  16. Identification of American shad spawning sites and habitat use in the Pee Dee River, North Carolina and South Carolina

    Science.gov (United States)

    Harris, Julianne E.; Hightower, Joseph E.

    2011-01-01

    We examined spawning site selection and habitat use by American shad Alosa sapidissima in the Pee Dee River, North Carolina and South Carolina, to inform future management in this flow-regulated river. American shad eggs were collected in plankton tows, and the origin (spawning site) of each egg was estimated; relocations of radio-tagged adults on spawning grounds illustrated habitat use and movement in relation to changes in water discharge rates. Most spawning was estimated to occur in the Piedmont physiographic region within a 25-river-kilometer (rkm) section just below the lowermost dam in the system; however, some spawning also occurred downstream in the Coastal Plain. The Piedmont region has a higher gradient and is predicted to have slightly higher current velocities and shallower depths, on average, than the Coastal Plain. The Piedmont region is dominated by large substrates (e.g., boulders and gravel), whereas the Coastal Plain is dominated by sand. Sampling at night (the primary spawning period) resulted in the collection of young eggs (≤1.5 h old) that more precisely identified the spawning sites. In the Piedmont region, most radio-tagged American shad remained in discrete areas (average linear range = 3.6 rkm) during the spawning season and generally occupied water velocities between 0.20 and 0.69 m/s, depths between 1.0 and 2.9 m, and substrates dominated by boulder or bedrock and gravel. Tagged adults made only small-scale movements with changes in water discharge rates. Our results demonstrate that the upstream extent of migration and an area of concentrated spawning occur just below the lowermost dam. If upstream areas have similar habitat, facilitating upstream access for American shad could increase the spawning habitat available and increase the population's size.

  17. Characterisation of Shigella species isolated from river catchments in the North West province of South Africa

    Directory of Open Access Journals (Sweden)

    Constance Wose Kinge

    2010-10-01

    Full Text Available The occurrence and distribution of Shigella species in water from the five river catchments in the North West province of South Africa were investigated. Shigella is a Gram-negative, non-motile, facultative anaerobic bacillus that causes shigellosis, an important cause of morbidity and mortality in high-risk populations (such as children, the elderly and immuno-compromised individuals that depend on river water. A total of 54 water samples collected in winter (April 2007 to July 2007 and summer (December 2007 to March 2008 were cultured on Salmonella-Shigella agar by the spread-plate method. Suspected Shigella isolates obtained were characterised by primary biochemical (Triple Sugar Iron agar and agglutination and molecular (polymerase chain reactions, PCR tests. Amplification of the invasion plasmid gene (ipaH by PCR was done to confirm the presence of Shigella spp. in water. In total, 214 Shigella boydii, 15 Shigella dysenteriae, 11 Shigella flexneri and 2 Shigella sonnei were confirmed by serotyping in both winter and summer samples. The ipaH gene (606 bp was present in 176 and 49 of the winter and summer isolates, respectively. The presence of Shigella spp. in water was confirmed with over 90% specificity. The need for more effective management of these river catchments and the provision of potable water and sanitation facilities is needed to minimise the occurrence and transmission of water-borne diseases caused by these and other pathogenic bacteria.

  18. Tank Model Application for Runoff and Infiltration Analysis on Sub-Watersheds in Lalindu River in South East Sulawesi Indonesia

    Science.gov (United States)

    Wirdhana Ahmad, Sitti

    2017-05-01

    Improper land management often causes flood, this is due to uncontrolled runoff. Runoff is affected by the management of the land cover. The phenomena also occurred in South East Sulawesi, Indonesia. This study aims to analyze the flow rate of water in watershed of Lalindu River in North Konawe, South East Sulawesi by using a Tank Model. The model determined the magnitude of the hydrologic runoff, infiltration capacity and soil water content several land uses were evaluated in the study area. The experimental and calculation results show that the runoff in the forest is 2,639.21 mm/year, in the reed is 2,517.05 mm/year, in the oil palm with a slope more than 45% is 2,715.36 mm/year, and in the oil palm with slopes less than 45% is 2,709.59 mm/year. Infiltration in the forest is 30.70 mm/year, in the reed is 7.51 mm/year, in the palm oil with a slope more than 45% is 24.13 mm/year and in the palm oil with slopes less than 45% is 29.67 mm/year. Runoff contributes to stream flow for water availability.

  19. Assessing the Habitat Suitability of Dam Reservoirs: A Quantitative Model and Case Study of the Hantan River Dam, South Korea

    Directory of Open Access Journals (Sweden)

    Hyeongsik Kang

    2016-11-01

    Full Text Available The main objective of this study was to investigate ecologically healthy regions near a dam reservoir. This study developed a model for assessing habitat suitability as a proxy for the ecological value of reservoirs. Three main factors comprising nine assessment variables were selected and classified as having a habitat suitability (HS between 0 and 1: (1 geomorphic factors of altitude, slope steepness, and slope aspect; (2 vegetation factors of forest physiognomy, vegetation type, and tree age; and (3 ecological factors of land cover, ecological quality index, and environmental conservation value assessment. The spatial distribution of the nine HS indices was determined using geographic information systems and combined into one HS index value to determine ecologically healthy regions. The assessment model was applied to areas surrounding the Hantan River Dam, South Korea. To verify the model, wildlife location data from the national ecosystem survey of the Ministry of Environment were used. Areas with an HS index between 0.73 and 1 were found to contain 72% of observed wildlife locations. Ecologically healthy areas were identified by adding the indices of each variable. The methods shown here will be useful for establishing ecological restoration plans for dam reservoirs in South Korea.

  20. Identification guide to some Diaptomid species (Crustacea, Copepoda, Calanoida, Diaptomidae) of "de la Plata" River Basin (South America).

    Science.gov (United States)

    Perbiche-Neves, Gilmar; Boxshall, Geoffrey Allan; Previattelli, Daniel; Nogueira, Marcos Gomes; da Rocha, Carlos Eduardo Falavigna

    2015-01-01

    An identification guide is presented for species of calanoid copepod family Diaptomidae from "de la Plata" River Basin (Argentina, Brazil, Bolivia, Paraguay and Uruguay). It was based on material collected during the summer and winter of 2010 from 43 sites across the eastern part and the lower stretches of this basin, the second largest in South America and the fourth in the world. The guide contains identification keys and species diagnoses for males and females, richly supported by scanning electronic micrographs and/or line drawings of 19 species. It also includes some general remarks on the taxonomy and phylogenetic relationships of these species. The key was adjusted to be useful for these species only, with separate keys for each sex, and is the first for females of South America. One species classified herein as incertae sedis was not included in the analysis. At least ten other species have previously been recorded in the basin but were not present in our samples. This is the first attempt to compile comprehensive taxonomic information on this group of copepods in this region, and it is expected to become a useful tool for biologists and young taxonomists interested in the crustacean biota of the Neotropical region.

  1. Environmental Studies of Little River Inlet, Horry County, South Carolina and Brunswick County, North Carolina.

    Science.gov (United States)

    1976-09-01

    lJRA-7 1.RA--8 Phylum Pori fera Cliona celata + + Cliena tntiitti + + Phylum Cnidaria Ectepleura dumortieri + + Turritopsis nutricula ...area have been closed by the South Caroliva Department of Health and Environmental Control. The lowest oxygen value observed was a .6.5 mg/l in a

  2. The nature of riverbank erosion along the South River, Virginia revealed through terrestrial laser-scanner surveys

    Science.gov (United States)

    O'Neal, M. A.; Pizzuto, J. E.

    2012-12-01

    We surveyed 23 eroding banks along the South River, Virginia between 2006 and 2008 CE using a terrestrial laser scanner. At 6 sites with varying bank vegetation, soil type, and geomorphic settings, a total of 11 repeat surveys were completed to document rates and spatial patterns of contemporary bank erosion. Time intervals between surveys ranged from 89 days to 421 days. Our survey data, averaging 15,000 points per square meter, were manually and mathematically filtered to remove non-bank elements and converted into 0.05 m x 0.05 m gridded models. Comparison of our data-dense, mathematically filtered models indicates that the streamwise spatial extent of significant erosion varied from 0% to about 80% of the surveyed bank area. Annualized maximum rates of localized bank erosion varied from 0 to about 2.4 m/yr, the latter of which greatly exceeds estimated rates from historical aerial photographs. Comparison of our LIDAR-derived erosion rates, with those from field observations, identified the geologic setting (i.e. bank material type) as the most important control on the extent of bank erosion and suggests that large trees can reduce erosion rates. Model comparisons indicate that maximum erosion along the forested banks focused around leaning trees, while elsewhere the extent of bank retreat was negligible. On grassy banks, retreat was controlled by the creation of small overhanging clumps of turf at the top of the bank, their occasional failure, and the ultimate removal of failed debris from the bank toe. Partial autocorrelation analysis of vertically integrated bank retreat at two eroding banks demonstrates that bank profile erosion is virtually uncorrelated at horizontal distances greater than about 1 m, a length scale of approximately half the bank height. This extensive streamwise variability suggests that widely spaced profile data cannot adequately represent bank erosion at these sites. Additional analysis of our comprehensive spatial data also indicates

  3. Aquatic biological communities and associated habitats at selected sites in the Big Wood River Watershed, south-central Idaho, 2014

    Science.gov (United States)

    MacCoy, Dorene E.; Short, Terry M.

    2016-09-28

    Assessments of streamflow (discharge) parameters, water quality, physical habitat, and biological communities were completed between May and September 2014 as part of a monitoring program in the Big Wood River watershed of south-central Idaho. The sampling was conducted by the U.S. Geological Survey in cooperation with Blaine County, Trout Unlimited, the Nature Conservancy, and the Wood River Land Trust to help identify the status of aquatic resources at selected locations in the watershed. Information in this report provides a basis with which to evaluate and monitor the long-term health of the Big Wood River and its major tributaries. Sampling sites were co-located with existing U.S. Geological Survey streamgaging stations: three on the main stem Big Wood River and four on the North Fork Big Wood River (North Fork), Warm Springs Creek (Warm Sp), Trail Creek (Trail Ck), and East Fork Big Wood River (East Fork) tributaries.The analytical results and quality-assurance information for water quality, physical habitat, and biological community samples collected at study sites during 2 weeks in September 2014 are summarized. Water-quality data include concentrations of major nutrients, suspended sediment, dissolved oxygen, and fecal-coliform bacteria. To assess the potential effects of nutrient enrichment on algal growth, concentrations of periphyton biomass (chlorophyll-a and ash free dry weight) in riffle habitats were determined at each site. Physical habitat parameters include stream channel morphology, habitat volume, instream structure, substrate composition, and riparian vegetative cover. Biological data include taxa richness, abundance, and stream-health indicator metrics for macroinvertebrate and fish communities. Statistical summaries of the water-quality, habitat, and biological data are provided along with discussion of how these findings relate to the health of aquatic resources in the Big Wood River watershed.Seasonal discharge patterns using statistical

  4. Population status of the American alligator on the Savannah River Plant, South Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, T.M.

    1981-04-01

    Estimates are presented of alligator numbers, size distribution, sex ratios, reproductive effort, and population trends for all major components of the entire Savannah River Plant (SRP) alligator population. Savannah River Plant operations have impacted the alligator population in many different ways. The formation of man-made reservoirs has dramatically increased the amount of aquatic habitat available to alligators and has therefore increased the carrying capacity of the SRP site for this species. The thermal alteration of aquatic habitats on the SRP has also impacted the resident alligator population. Temperature elevations of aquatic habitat to greater than 38/sup 0/C result in the loss of this habitat to alligators. Moderate thermal increases on the other hand are responded to by alligator movement. The current information available on the alligators of the SRP suggests the following future trends: low density populations distant from thermally altered areas will continue at a low density with the exception of localized increases.

  5. Improved correction method for using passive air samplers to assess the distribution of PCNs in the Dongjiang River basin of the Pearl River Delta, South China

    Science.gov (United States)

    Wang, Yan; Li, Qilu; Xu, Yue; Luo, Chunling; Liu, Xiang; Li, Jun; Zhang, Gan

    2012-07-01

    An improved correction method was established using passive air samplers to assess the distributions of polychlorinated naphthalenes (PCNs) in the eastern Pearl River Delta, South China. This method was based on a joint correction that used the active air sampling rate and the addition of depuration compounds. As a correction factor, the depuration compounds' properties do not need to be similar to the target compounds. The total PCN air concentrations ranged from 6.4 to 832, with an average of 148 ± 201 pg m-3 in the study area, while the TEQ of the PCNs ranged from 1.2 × 10-4 to 2.6 × 10-2 pg m-3. High concentrations of PCNs were mostly observed in the highly industrialized areas. The PCN air levels were remarkably increased in winter compared with summer. Tri-CNs was the most dominant homologue group, while CN 24 was the most dominant congener. The high proportion of combustion-related PCNs suggests that the contribution of combustion sources to the PCN air burden has been significant recently in comparison with historical emissions.

  6. Nutrient dynamics in tropical rivers, lagoons, and coastal ecosystems of eastern Hainan Island, South China Sea

    Science.gov (United States)

    Li, R. H.; Liu, S. M.; Li, Y. W.; Zhang, G. L.; Ren, J. L.; Zhang, J.

    2014-01-01

    Nutrient dynamics based on field observations made along the eastern Hainan Island during the period 2006-2009 were investigated to understand nutrient biogeochemical processes, and to provide an overview of human perturbations of coastal ecosystems in this tropical region. The rivers showed seasonal variations in nutrient concentrations, with enrichment of dissolved inorganic nitrogen and dissolved silicate, and depletion of PO43-. High riverine concentrations of nitrate mainly originated from agricultural fertilizer inputs. The DIN : PO43- ratios ranged from 37 to 1063, suggesting preferential depletion of PO43- relative to nitrogen in rivers. Chemical weathering in the drainage area might explain the high levels of dissolved silicate. Aquaculture ponds contained high concentrations of NH4+ and dissolved organic nitrogen. The particulate phosphorus concentrations in the study area were lower than those reported for estuaries worldwide. The particulate silicate levels in rivers and lagoons were lower than the global average level. Nutrient biogeochemistry in coastal areas was affected by human activities (e.g., aquaculture, agriculture), and by natural phenomena including typhoons. The nutrient concentrations in coastal waters were low because of dispersion of land-derived nutrients in the sea. Nutrient budgets were built based on a steady-state box model, which showed that riverine fluxes are magnified by estuarine processes (e.g., regeneration, desorption) in estuaries and Laoyehai Lagoon, but not in Xiaohai Lagoon. Riverine and groundwater inputs were the major sources of nutrients to Xiaohai and Laoyehai lagoons, respectively, and riverine inputs and aquaculture effluents were the major sources for the eastern coast of Hainan Island. Nutrient inputs to the coastal ecosystem increased with typhoon-induced runoff of rainwater, elucidating the important influence of typhoons on small tropical rivers.

  7. Nutrient dynamics in tropical rivers, lagoons, and coastal ecosystems of eastern Hainan Island, South China Sea

    OpenAIRE

    Li, R. H.; Liu, S.M.; Li, Y. W.; Zhang, G.L.; Ren, J. L.; Zhang, J.

    2014-01-01

    Nutrient dynamics based on field observations made along the eastern Hainan Island during the period 2006–2009 were investigated to understand nutrient biogeochemical processes, and to provide an overview of human perturbations of coastal ecosystems in this tropical region. The rivers showed seasonal variations in nutrient concentrations, with enrichment of dissolved inorganic nitrogen and dissolved silicate, and depletion of PO43−. High riverine concentrations of nitr...

  8. Ecological Effects of the South-to-North Water Diversion Project on the Hanjiang River

    Institute of Scientific and Technical Information of China (English)

    DU Yun; WANG Xuelei; CAI Shuming

    2006-01-01

    @@ The middle and lower reaches of the Hanjiang River are the center of local economic development in the region. For a long time the mother nature's mighty force and mankind's infringement have led to a series of ecological problems,such as flooding and water-logging calamities, droughts, soil erosion &water loss, downgrade of environmental quality, shrinkage of wetland resources, posing threats to the valley's sustainable development.

  9. Flow seasonality and fish assemblage in a tropical river, French Guiana, South America

    Directory of Open Access Journals (Sweden)

    Francisco Leonardo Tejerina-Garro

    Full Text Available The objective of this study is to verify the existence of a seasonal pattern of variation in the fish assemblages of a tropical river using taxonomic and functional descriptors. Fish were sampled using gillnets at two sites on the Comté River, a large-sized river 254.8 km long, flowing entirely through rainforest areas of French Guiana. Samplings were conducted every other month from August 1998 to July 2000. Four types of fish assemblage descriptors were used: the species descriptor (number of individual fish of each species in the sample; the family descriptor (number of individual fish of each family in the sample; the trophic descriptor (distribution of the fish biomass in each feeding guild and the specific maximum observed size - MOS (number of individual fish in each of four classes of MOS: 300 mm. Results point out that changes in the fish assemblage are related to water level oscillations. The role of migration seems to be weak and is limited to trophic displacements characteristic of few species. In the low-water season, characterized by weak water level oscillation, fish species and families belonging to piscivorous or aquatic invertivorous guilds were predominant, whereas in the high-water season the environment is submitted to strong variations caused by fast and large water level oscillations, and the fish assemblage was characterized by species or families with an opportunistic omnivorous diet.

  10. Distribution of organophosphorus flame retardants in sediments from the Pearl River Delta in South China.

    Science.gov (United States)

    Tan, Xiao-Xin; Luo, Xiao-Jun; Zheng, Xiao-Bo; Li, Zong-Rui; Sun, Run-Xia; Mai, Bi-Xian

    2016-02-15

    Twelve organophosphorus flame retardants (PFRs) were identified in the sediments and the sediment core collected from the rivers and the estuary in the Pearl River Delta, with the aim of investigating their spatial and vertical distributions. The concentrations of PFRs ranged from 8.3 to 470 ng/g dry weight with high levels of PFRs in the urban area and the e-waste recycling region. Generally, TPhP, TCPP, TEHP, TCEP, and TBEP were the dominant compounds of the PFRs, the composition of which varied across the different regions, reflecting the different sources of PFRs. In the estuary, the PFRs mainly derived from the Xijiang River and the Shunde sections. Increased concentrations of halogen-containing PFRs have been observed in the upper layers of the sediment core. Conversely, relatively high concentrations of halogen-free PFRs were observed in the lower layers of the sediment core, indicating different usage patterns or environmental behaviors between the halogen and the non-halogen PFRs in the study area.

  11. Using the SPEI to Assess Recent Climate Change in the Yarlung Zangbo River Basin, South Tibet

    Directory of Open Access Journals (Sweden)

    Binquan Li

    2015-10-01

    Full Text Available The Yarlung Zangbo River (YZR is the largest river system in the Tibetan Plateau, and its basin is one of the centers of human economic activity in Tibet. Large uncertainties exist in several previous climate change studies in this basin because of limited climate observations. In this paper, we used a meteorological drought index (Standardized Precipitation Evapotranspiration Index, SPEI and a newly-released gridded climate forcing dataset based on high-quality climate station data to re-evaluate climate change in the YZR Basin during the period of 1961–2014. Results showed that precipitation experienced a statistically insignificant increasing trend at a rate of 6.32 mm/10 years, and its annual mean was 512.40 mm. The basin was sensitive to climate change in terms of the air temperature that significantly increased at the rate of 0.32 °C/10 years. This warming rate was obviously larger than that in many other regions. Analysis of SPEI showed that the basin had no obvious statistical trends in the number of dry/wet episodes, but the severity of dry episode aggravated in terms of duration and magnitude. This study provides a reliable analysis of climate change in the YZR Basin, and suggests this large Tibetan river basin is sensitive to climate change.

  12. Magnetic signature of river sediments drained into the southern and eastern part of the South China Sea (Malay Peninsula, Sumatra, Borneo, Luzon and Taiwan)

    Science.gov (United States)

    Kissel, Catherine; Liu, Zhifei; Li, Jinhua; Wandres, Camille

    2017-01-01

    Magnetic properties of 22 river samples collected in the Malay Peninsula, Sumatra, Borneo, Luzon and Taiwan have been investigated in order to magnetically characterize the sediments drained and deposited into the South China Sea. The geological formations as well as the present climatic conditions are different from one region to another. Laboratory analyses include low-field magnetic susceptibility, anhysteretic (ARM) and isothermal (IRM) remanent magnetizations acquisition and decay, back-field acquisition, thermal demagnetization of three-axes IRM, hysteresis cycles and low-temperature magnetic measurements. The magnetic properties indicate that the sediments are a mixture of hematite, magnetite and pyrrhotite in different proportions depending on the region. Combined with results previously reported for the three main Asian rivers (Pearl, Red and Mekong rivers), the new data indicate that, in general, hematite-rich sediments are delivered to the southern basin of the South China Sea while the northern basin is fed with magnetite and pyrrhotite-rich sediments. In addition to this general picture, some variability is observed at smaller geographic scales. Indeed, the magnetic assemblages are closely related to the geology of the various catchments while clay minerals, previously reported for the same samples, are more representative of the climatic conditions under which the parent rocks have evolved within each catchment. The magnetic fraction, now well characterized in the main river sediments drained into the South China Sea, can be used as a tracer for changes in precipitation on land and in oceanic water mass transport and exchange.

  13. Assessment of Trace Metals Contamination of Surface Water and Sediment: A Case Study of Mvudi River, South Africa

    Directory of Open Access Journals (Sweden)

    Joshua N. Edokpayi

    2016-02-01

    Full Text Available Trace metals contamination of rivers and sediments remains a global threat to biodiversity and humans. This study was carried out to assess the variation pattern in trace metals contamination in Mvudi River water and sediments for the period of January–June 2014. Metal concentrations were analyzed using an inductively-coupled plasma optical emission spectrometer after nitric acid digestion. A compliance study for the water samples was performed using the guidelines of the Department of Water Affairs and Forestry (DWAF of South Africa and the World Health Organization (WHO. The National Oceanic and Atmospheric Administration (NOAA sediment quality guidelines for marine and estuarine sediments and the Canadian Council of Ministers of the Environment sediment guidelines (CCME for freshwater sediments were used to determine the possible toxic effects of the metals on aquatic organisms. pH (7.2–7.7 and conductivity (10.5–16.1 mS/m values complied with DWAF and WHO standards for domestic water use. Turbidity values in nephelometric turbidity units (NTU were in the range of 1.9–429 and exceeded the guideline values. The monthly average levels of trace metals in the water and sediments of Mvudi River were in the range of: Al (1.01–9.644 mg/L and 4296–5557 mg/kg, Cd (0.0003–0.002 mg/L and from below the detection limit to 2.19 mg/kg, Cr (0.015–0.357 mg/L and 44.23–149.52 mg/kg, Cu (0.024–0.185 mg/L and 13.22–1027 mg/kg, Fe (0.702–2.645 mg/L and 3840–6982 mg/kg, Mn (0.081–0.521 mg/L and 279–1638 mg/kg, Pb (0.002–0.042 mg/L and 1.775-4.157 mg/kg and Zn (0.031–0.261 mg/L and 14.481–39.88 mg/kg. The average concentrations of Al, Cr, Fe, Mn and Pb in the water samples exceeded the recommended guidelines of DWAF and WHO for domestic water use. High concentrations of Al and Fe were determined in the sediment samples. Generally, the concentrations of Cd, Cr and Cu in the sediments exceeded the corresponding effect range low

  14. GIS/RS-based Integrated Eco-hydrologic Modeling in the East River Basin, South China

    Science.gov (United States)

    Wang, Kai

    Land use/cover change (LUCC) has significantly altered the hydrologic system in the East River (Dongjiang) Basin. Quantitative modeling of hydrologic impacts of LUCC is of great importance for water supply, drought monitoring and integrated water resources management. An integrated eco-hydrologic modeling system of Distributed Monthly Water Balance Model (DMWBM), Surface Energy Balance System (SEBS) was developed with aid of GIS/RS to quantify LUCC, to conduct physically-based ET (evapotranspiration) mapping and to predict hydrologic impacts of LUCC. To begin with, in order to evaluate LUCC, understand implications of LUCC and provide boundary condition for the integrated eco-hydrologic modeling, firstly the long-term vegetation dynamics was investigated based on Normalized Difference Vegetation Index (NDVI) data, and then LUCC was analyzed with post-classification methods and finally LUCC prediction was conducted based on Markov chain model. The results demonstrate that the vegetation activities decreased significantly in summer over the years. Moreover, there were significant changes in land use/cover over the past two decades. Particularly there was a sharp increase of urban and built-up area and a significant decrease of grassland and cropland. All these indicate that human activities are intensive in the East River Basin and provide valuable information for constructing scenarios for studying hydrologic impacts of LUCC. The physically-remote-sensing-based Surface Energy Balance System (SEBS) was employed to estimate areal actual ET for a large area rather than traditional point measurements . The SEBS was enhanced for application in complex vegetated area. Then the inter-comparison with complimentary ET model and distributed monthly water balance model was made to validate the enhanced SEBS (ESEBS). The application and test of ESEBS show that it has a good accuracy both monthly and annually and can be effectively applied in the East River Basin. The results of

  15. Nutrient characterisation of river inflow into the estuaries of the Gouritz Water Management Area, South Africa

    CSIR Research Space (South Africa)

    Lemley, DA

    2014-10-01

    Full Text Available cycling (Buzzelli et al., 2007; Buzzelli, 2012). A great deal of emphasis has been placed on determining the consequences of these anthropogenic stressors on estuaries through the use of monitoring programmes (Carstensen et al., 2012). In South Africa... systems. Assessing the effectiveness and compliance of WWTPs is essential to providing a complete and holis- tic overview of water quality inputs into the estuaries of the Gouritz WMA. Effluents from WWTPs are discharged to sur- face waters, after...

  16. Computation of groundwater resources and recharge in Chithar River Basin, South India.

    Science.gov (United States)

    Subramani, T; Babu, Savithri; Elango, L

    2013-01-01

    Groundwater recharge and available groundwater resources in Chithar River basin, Tamil Nadu, India spread over an area of 1,722 km(2) have been estimated by considering various hydrological, geological, and hydrogeological parameters, such as rainfall infiltration, drainage, geomorphic units, land use, rock types, depth of weathered and fractured zones, nature of soil, water level fluctuation, saturated thickness of aquifer, and groundwater abstraction. The digital ground elevation models indicate that the regional slope of the basin is towards east. The Proterozoic (Post-Archaean) basement of the study area consists of quartzite, calc-granulite, crystalline limestone, charnockite, and biotite gneiss with or without garnet. Three major soil types were identified namely, black cotton, deep red, and red sandy soils. The rainfall intensity gradually decreases from west to east. Groundwater occurs under water table conditions in the weathered zone and fluctuates between 0 and 25 m. The water table gains maximum during January after northeast monsoon and attains low during October. Groundwater abstraction for domestic/stock and irrigational needs in Chithar River basin has been estimated as 148.84 MCM (million m(3)). Groundwater recharge due to monsoon rainfall infiltration has been estimated as 170.05 MCM based on the water level rise during monsoon period. It is also estimated as 173.9 MCM using rainfall infiltration factor. An amount of 53.8 MCM of water is contributed to groundwater from surface water bodies. Recharge of groundwater due to return flow from irrigation has been computed as 147.6 MCM. The static groundwater reserve in Chithar River basin is estimated as 466.66 MCM and the dynamic reserve is about 187.7 MCM. In the present scenario, the aquifer is under safe condition for extraction of groundwater for domestic and irrigation purposes. If the existing water bodies are maintained properly, the extraction rate can be increased in future about 10% to 15%.

  17. Ecohydrological implications of runoff harvesting in the headwaters of the Thukela River basin, South Africa

    Science.gov (United States)

    De Winnaar, Gary; Jewitt, Graham

    Hydrological regimes have an important influence on biodiversity, structure, and functioning of aquatic ecosystems. Unforeseen circumstances, both hydrologically and ecologically, caused by potential adoption and expansion of runoff harvesting innovations is of particular concern to water resource planners, as downstream river systems are likely to be adversely affected. This paper provides methods for determining the influence that large-scale adoption of runoff harvesting could have on downstream flow regimes by using a scenario-based approach, with the ACRU Agrohydrological model, to simulate the potential alteration of streamflow regimes due to runoff harvesting. Scenarios were based entirely on the spatial extent of impervious surfaces associated with rural homesteads, estimates of which were taken from current population data and used to establish the density of hypothetical runoff harvesting systems within a catchment setup. Daily streamflow simulation from nine Quaternary Catchments in the Thukela River basin provided suitable data series’ for analysis using the Indicators of Hydrological Alteration method to compute ecologically relevant hydrological parameters. The outcome of this ecohydrological study demonstrated that a relatively simple modelling exercise offers the potential to assess impacts that may arise from large-scale runoff harvesting. Results established that magnitudes of high and low flows of river flow regimes were most affected by runoff harvesting. Flow reduction was found to be most significant with low flows (up to 29%) in the case where the maximum runoff harvesting scenario was used. However, the majority of the IHA hydrological flow parameters revealed only slight impacts, even under circumstances where modelling scenarios were based on unrealistically high proportions of runoff harvesting. Increasing the spatial extent of runoff harvesting is thus expected to have a much greater impact at smaller spatial scales; water resources of

  18. Groundwater quality assessment using chemometric analysis in the Adyar River, South India.

    Science.gov (United States)

    Venugopal, T; Giridharan, L; Jayaprakash, M

    2008-08-01

    A multivariate statistical technique has been used to assess the factors responsible for the chemical composition of the groundwater near the highly polluted Adyar River. Basic chemical parameters of the groundwater have been pooled together for evaluating and interpreting a few empirical factors controlling the chemical nature of the water. Twenty-three groundwater samples were collected in the vicinity of the Adyar River. Box-whisker plots were drawn to evaluate the chemical variation and the seasonal effect on the variables. R-mode factor analysis and cluster analysis were applied to the geochemical parameters of the water to identify the factors affecting the chemical composition of the groundwater. Dendograms of both the seasons gives two major clusters reflecting the groups of polluted and unpolluted stations. The other two minor clusters and the movement of stations from one cluster to another clearly bring out the seasonal variation in the chemical composition of the groundwater. The results of the R-mode factor analysis reveal that the groundwater chemistry of the study area reflects the influence of anthropogenic activities, rock-water interactions, saline water intrusion into the river water, and subsequent percolation into the groundwater. The complex geochemical data of the groundwater were interpreted by reducing them to seven major factors, and the seasonal variation in the chemistry of water was clearly brought out by these factors. The higher concentration of heavy metals such as Fe and Cr is attributed to the rock-water interaction and effluents from industries such as tanning, chrome-plating, and dyeing. In the urban area, the Pb concentration is high due to industrial as well as urban runoff of the atmospheric deposition from automobile pollution. Factor score analysis was used successfully to delineate the stations under study with the contributing factors, and the seasonal effect on the sample stations was identified and evaluated.

  19. Carbon and Manganese Cycling in the Columbia River's Estuarine Turbidity Maxima in the South Channel

    Science.gov (United States)

    Bräuer, S. L.; Kranzler, K.; Tebo, B. M.

    2007-12-01

    The Columbia River represents the largest input (60-90%) of fresh water to the California Current System, and provides a major source of dissolved manganese and nutrients to the coastal waters. Researchers have identified upper Estuarine Turbidity Maxima (ETM(s)) as hot spots for microbial activity, and it is here that extensive manganese cycling is thought to occur. Most probable number counts of microorganisms within the ETM have revealed that the cultivable numbers of manganese-oxidizing bacteria are not statistically significantly different than that of other heterotrophs when grown on defined media with simple carbon sources or low concentrations (0.05%) of casamino acids and were in the range of 103 - 104 cells per mL. Similar numbers of heterotrophs (9.3 X 103 cells/mL) were found using a nutrient-rich complex medium; however, the numbers of manganese-oxidizers were significantly lower (~13 cells/mL). Approximately 100 different manganese-oxidizing bacteria were isolated from different media and are being phylogenetically characterized. Measurements of dissolved, ascorbate-reducible and total Mn by inductively coupled plasma- optical emission spectroscopy revealed that concentrations of Mn are positively correlated with turbidity and thus are higher during an ETM event. In addition, dissolved, total, and ascorbate-reducible Mn were all negatively correlated with salinity, supporting the idea that the manganese originates in the river and is diluted by the seawater originating off the coast. Uptake of 14C-labeled bicarbonate in response to various electron donors (nitrite, ammonium, thiosulfate, or Mn(II)) was stimulated during an ETM event but not before or after, indicating that these electron donors may serve as potential energy sources for carbon fixation. Taken together, our results further demonstrate that ETMs are zones with high microbial activity and that the ETM microbial communities harbor the potential for carbon fixation even in the relatively

  20. Outburst fan deposit from pyroclastic flows, Williamson River canyon, south-central Oregon

    Science.gov (United States)

    Cummings, M. L.; Eibert, D.

    2016-12-01

    Pyroclastic flows from the Holocene eruption of Mount Mazama in the Cascade volcanic arc of Oregon, blocked the narrow (210 to 225 m wide, 35 to 40 m deep), bedrock-lined canyon of the Williamson River. The estimated volume of the long, narrow blockage was 4.4 x 10^7 cubic meters. The blockage eventually failed releasing an impounded lake and depositing a debris fan at the mouth of the canyon. Remnants of the debris fan underlie a gently sloping surface dissected by various abandoned channels of the river. The modern Williamson River cut its channel across the upper part of the fan. Three bedrock units are present as boulders: hydrovolcanic tuff (Di = 2.75 m) derived from tuff cones in the lower reaches of the canyon, distinctly layered geochemically primitive olivine basalt (Di = 3.4 m) that crops out approximately 6 km upstream, and massive basaltic andesite that underlies the channel in the upper canyon and cliffs that define the right bank of the canyon near the mouth. Matrix between boulders and deposits that flank and overlie the boulder deposit are dominated by medium- to fine-grained sand (ASTM; 61-70 wt. % in matrix; 76-100 wt. % elsewhere). Sand grains are predominantly well-rounded phenocryst-bearing glass that vary from massive to moderately vesiculated and crystals of plagioclase and hornblende commonly with attached remnants of groundmass. Crystals are most abundant in the medium- and fine-grained size range (>20 and fragments (twigs and molds) are common in medium-sand and larger. Elongate bars of rounded pumice gravel provide local current directions during the waning stage of the outburst flood. The thickness of the boulder deposit near the mouth of the canyon is not known. Sand deposits are 1 to 1.5 m thick near the mouth of the canyon and thin to 70 cm at about 3.4 km from the mouth of the canyon.

  1. South Fork Zumbro River Stage 1B, Rochester, Minnesota. Design Memorandum Number 2, Flood Control Project

    Science.gov (United States)

    1987-02-01

    Softb AMuchy, lack G M S, Very Dense, Block /00 Bo. 970 =_ Loose, Black-Gray 001, Very Dense, Tan -Gray 20 Very SofC Block TeO of Bedrock 2 , •MI P/a...Env cae,•,+,"’ epd ~-TaP ay. Dwq. 86 -1034e /0 May 49S6 :WS 9743 1 Water I To- of Bedrok -970 3 A/oaes: J .960 I/ ..Fork Zunbro River eev. 974.3: 2. ft

  2. Transfer of cadmium from soil to vegetable in the Pearl River Delta area, South China.

    Science.gov (United States)

    Zhang, Huihua; Chen, Junjian; Zhu, Li; Yang, Guoyi; Li, Dingqiang

    2014-01-01

    The purpose of this study was to investigate the regional Cadmium (Cd) concentration levels in soils and in leaf vegetables across the Pearl River Delta (PRD) area; and reveal the transfer characteristics of Cadmium (Cd) from soils to leaf vegetable species on a regional scale. 170 paired vegetables and corresponding surface soil samples in the study area were collected for calculating the transfer factors of Cadmium (Cd) from soils to vegetables. This investigation revealed that in the study area Cd concentration in soils was lower (mean value 0.158 mg kg(-1)) compared with other countries or regions. The Cd-contaminated areas are mainly located in west areas of the Pearl River Delta. Cd concentrations in all vegetables were lower than the national standard of Safe vegetables (0.2 mg kg(-1)). 88% of vegetable samples met the standard of No-Polluted vegetables (0.05 mg kg(-1)). The Cd concentration in vegetables was mainly influenced by the interactions of total Cd concentration in soils, soil pH and vegetable species. The fit lines of soil-to-plant transfer factors and total Cd concentration in soils for various vegetable species were best described by the exponential equation (y = ax(b)), and these fit lines can be divided into two parts, including the sharply decrease part with a large error range, and the slowly decrease part with a low error range, according to the gradual increasing of total Cd concentrations in soils.

  3. Distribution and risk assessment of 82 pesticides in Jiulong River and estuary in South China.

    Science.gov (United States)

    Zheng, Senllin; Chen, Bin; Qiu, Xiaoyan; Chen, Meng; Ma, Zhiyuan; Yu, Xingguang

    2016-02-01

    To discover the distribution and risk of pesticides in Jiulong River and estuary, the residues of 102 pesticides were analyzed in water, sediment and clam samples collected from 35 sites in different seasons. A total number of 82 pesticides were detected and the occurrence and the risk to human and fish were assessed. Most of pesticides with high frequency were medium or low toxic except for DDTs. DDTs were the significant contaminant and the widely used dicofol was the new source of DDTs. The spatial and seasonal variation of pesticide distribution was linked with the distribution of orchards and farmlands. Health risk from river water consumption was low (RQ Pesticides in water posed great risk to fish and among the 76 water samples analyzed, 65 of them showed high risk (RQ > 1) and 6 showed medium risk (0.1 ≤ QR pesticides detected with concentration above 100 ng L(-1) in this study and the pesticide with the highest concentration was procymidone (3904 ng L(-1)). Further experiments illustrated that procymidone could disrupt the expression of vitellogenin in the estuarine fish even at environmental concentrations. DDTs, dicofol, triazophos, isocarbophos, terbufos, cyfluthrin, bifenthrin, fenvalerate, cyhalothrin, butachlor and procymidone have become the significant pesticides and should be considered in aquatic ecosystem risk management.

  4. Preferential Petroleum Migration Pathways in Eastern Pearl River Mouth Basin,Offshore South China Sea

    Institute of Scientific and Technical Information of China (English)

    Yu Jianning; Zou Huayao; Gong Zaisheng

    2009-01-01

    Secondary petroleum migration in the eastern Pearl River Mouth basin was modeled using the three-dimensional PATHWAYSTM model,which assumes that the positions of petroleum migration pathways are controlled by the morphology of the sealing surfaces.The modeling results have accurately predicted the petroleum occurrences.Most commercial petroleum accumulations are along the predicted preferential petroleum migration pathways (PPMP),and most large fields (petroleum reserves greater than 1×108 t) have more than one preferential petroleum migration pathways to convey petroleum to the traps.The lateral migration distance for oil in the LH11-1 field,the largest oilfield so far discovered in the Pearl River Mouth basin,was more than 80 km.The case study suggests that in lacustrine fault basins,petroleum can migrate over a long distance to form large oilfields without driving force from groundwater flow.The focusing of petroleum originating from a large area of the generative kitchens into restricted channels seems to be essential not only for long-range petroleum migration in hydrostatic conditions,but also for the formation of large oil or gas fields.The strong porosity and permeability heterogeneities of the carrier beds and the relatively high prediction accuracy by a model that does not take into consideration of the effect of heterogeneity suggest that the positions of petroleum migration pathways in heterogeneous carrier beds with relatively large dipping angles are determined primarily by the morphology of the sealing surfaces at regional scales.

  5. Winter raptor use of the Platte and North Platte River Valleys in south central Nebraska

    Science.gov (United States)

    Lingle, G.R.

    1989-01-01

    Winter distribution and abundance of raptors were monitored within the Platte and North Platte river valleys. Data were collected along 265 km of census routes along the Platte and North Platte rivers during the winters of 1978-1979 and 1979-1980. Observations recorded during the second winter involved less observation time and were at somewhat different periods. There were 1574 sightings of 15 species representing 3 raptor families. Number of raptors observed on 54 days from 15 November to 13 February 1978-1979 was 48.3 per 100 km. In 20 days of observation from 5 December to 6 March 1979-1980, 39.7 raptors were observed per 100 km. Small mammal indices were 21 and 12 captures per 1000 trap nights during November 1978 and 1979, respectively. Raptors were sighted most frequently in riverine habitat and least in pasture and tilled fields. American kestrels (Falco sparverius) (11.1 individuals/100 km), red-tailed hawks (Buteo jamaicensis) (9.9), and bald eagles (Haliaeetus leucocephalus) (9.6) were the most frequently sighted raptors. Northern harrier (Circus cyaneus), rough-legged hawk (B. lagopus), and prairie falcon (P. mexicanus) sightings were 3.4, 3.4, and 1.7, respectively. Nine species were seen at a frequency of less than 1.0 individuals/100 km. Improved foraging conditions throughout the region resulted in fewer raptors sighted in 1979-1980.

  6. Transfer of cadmium from soil to vegetable in the Pearl River Delta area, South China.

    Directory of Open Access Journals (Sweden)

    Huihua Zhang

    Full Text Available The purpose of this study was to investigate the regional Cadmium (Cd concentration levels in soils and in leaf vegetables across the Pearl River Delta (PRD area; and reveal the transfer characteristics of Cadmium (Cd from soils to leaf vegetable species on a regional scale. 170 paired vegetables and corresponding surface soil samples in the study area were collected for calculating the transfer factors of Cadmium (Cd from soils to vegetables. This investigation revealed that in the study area Cd concentration in soils was lower (mean value 0.158 mg kg(-1 compared with other countries or regions. The Cd-contaminated areas are mainly located in west areas of the Pearl River Delta. Cd concentrations in all vegetables were lower than the national standard of Safe vegetables (0.2 mg kg(-1. 88% of vegetable samples met the standard of No-Polluted vegetables (0.05 mg kg(-1. The Cd concentration in vegetables was mainly influenced by the interactions of total Cd concentration in soils, soil pH and vegetable species. The fit lines of soil-to-plant transfer factors and total Cd concentration in soils for various vegetable species were best described by the exponential equation (y = ax(b, and these fit lines can be divided into two parts, including the sharply decrease part with a large error range, and the slowly decrease part with a low error range, according to the gradual increasing of total Cd concentrations in soils.

  7. Sources of suspended-sediment loads in the lower Nueces River watershed, downstream from Lake Corpus Christi to the Nueces Estuary, south Texas, 1958–2010

    Science.gov (United States)

    Ockerman, Darwin J.; Heitmuller, Franklin T.; Wehmeyer, Loren L.

    2013-01-01

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Army Corps of Engineers, Fort Worth District; City of Corpus Christi; Guadalupe-Blanco River Authority; San Antonio River Authority; and San Antonio Water System, developed, calibrated, and tested a Hydrological Simulation Program-FORTRAN (HSPF) watershed model to simulate streamflow and suspended-sediment concentrations and loads during 1958-2010 in the lower Nueces River watershed, downstream from Lake Corpus Christi to the Nueces Estuary in south Texas. Data available to simulate suspended-sediment concentrations and loads consisted of historical sediment data collected during 1942-82 in the study area and suspended-sediment concentration data collected periodically by the USGS during 2006-7 and 2010 at three USGS streamflow-gaging stations (08211000 Nueces River near Mathis, Tex. [the Mathis gage], 08211200 Nueces River at Bluntzer, Tex. [the Bluntzer gage], and 08211500 Nueces River at Calallen, Tex. [the Calallen gage]), and at one ungaged location on a Nueces River tributary (USGS station 08211050 Bayou Creek at Farm Road 666 near Mathis, Tex.). The Mathis gage is downstream from Wesley E. Seale Dam, which was completed in 1958 to impound Lake Corpus Christi. Suspended-sediment data collected before and after completion of Wesley E. Seale Dam provide insights to the effects of the dam and reservoir on suspended-sediment loads transported by the lower Nueces River downstream from the dam to the Nueces Estuary. Annual suspended-sediment loads at the Nueces River near the Mathis, Tex., gage were considerably lower for a given annual mean discharge after the dam was completed than before the dam was completed.

  8. Organochlorines in sediments and mussels collected from coastal sites along the Pearl River Delta,South China

    Institute of Scientific and Technical Information of China (English)

    FANG Zhan-qiang

    2004-01-01

    The level and pattern of residues of organochlorine pesticide and polychlorinated biphenyls (PCBs) wereanalyzed in sediment and mussel( Perna viridis) samples from ten coastal sites along the Pearl River Delta, SouthChina. The range of total HCH was < 0.01 to 0.29 ng/g freeze-dried weight in sediment, and < 0.01 to 1.35 ng/glipid weight in mussels. Average total DDTs concentrations ranged from < 0.01 to 1.04 ng/g in sediment, and< 0.01 to 148.5 ng/g in mussels. Average total PCB concentrations ranged from 16.4 to 198.6 ng/g in sediment,and from 41 to 729.2 ng/g in mussels. Organochlorine pesticide and PCBs in mussels and sediments presentedsimilar distribution patterns. The regression analysis indicated that PCBs concentrations in mussels were significantlycorrelated ( p < 0.01 ) with concentrations in sediments. However, their concentrations in mussels were several timeshigher than the concentration detected in surrounding sediments. The major fraction of DDT related compoundsmeasured in mussels and sediments was DDD. Based on average PCB concentrations, penta-, hexa-, andtetrachlorobiphenyls were preferentially accumulated by mussels as compared to the average sediment composition.According to the present results, three organochlorine polluted "hot spot" sites, including Victoria Harbour, LingdingYang and Huangmao Sea, were found in the Pearl River estuarine zone. HCHs, DDTs and PCBs in all musselsamples were below the limits of 2, 0.2 and 5.0 μg/g wet weight recommended by the Technical Group ofGuangdong Coastal Zone Resource Comprehensive Survey and U. S. Food and Drug Administration.

  9. Characterization of gas hydrate distribution using conventional 3D seismic data in the Pearl River Mouth Basin, South China Sea

    Science.gov (United States)

    Wang, Xiujuan; Qiang, Jin; Collett, Timothy S.; Shi, Hesheng; Yang, Shengxiong; Yan, Chengzhi; Li, Yuanping; Wang, Zhenzhen; Chen, Duanxin

    2016-01-01

    A new 3D seismic reflection data volume acquired in 2012 has allowed for the detailed mapping and characterization of gas hydrate distribution in the Pearl River Mouth Basin in the South China Sea. Previous studies of core and logging data showed that gas hydrate occurrence at high concentrations is controlled by the presence of relatively coarse-grained sediment and the upward migration of thermogenic gas from the deeper sediment section into the overlying gas hydrate stability zone (BGHSZ); however, the spatial distribution of the gas hydrate remains poorly defined. We used a constrained sparse spike inversion technique to generate acoustic-impedance images of the hydrate-bearing sedimentary section from the newly acquired 3D seismic data volume. High-amplitude reflections just above the bottom-simulating reflectors (BSRs) were interpreted to be associated with the accumulation of gas hydrate with elevated saturations. Enhanced seismic reflections below the BSRs were interpreted to indicate the presence of free gas. The base of the BGHSZ was established using the occurrence of BSRs. In areas absent of well-developed BSRs, the BGHSZ was calculated from a model using the inverted P-wave velocity and subsurface temperature data. Seismic attributes were also extracted along the BGHSZ that indicate variations reservoir properties and inferred hydrocarbon accumulations at each site. Gas hydrate saturations estimated from the inversion of acoustic impedance of conventional 3D seismic data, along with well-log-derived rock-physics models were also used to estimate gas hydrate saturations. Our analysis determined that the gas hydrate petroleum system varies significantly across the Pearl River Mouth Basin and that variability in sedimentary properties as a product of depositional processes and the upward migration of gas from deeper thermogenic sources control the distribution of gas hydrates in this basin.

  10. Tracing recent environmental changes and pedogenesis using geochemistry and micromorphology of alluvial soils, Sabie-Sand River Basin, South Africa

    Science.gov (United States)

    Eze, Peter N.; Knight, Jasper; Evans, Mary

    2016-09-01

    Three pedons on the alluvial terraces of the Sabie-Sand River Basin within Kruger National Park, South Africa, were studied to improve our understanding of recent environmental changes, and assess degree of chemical weathering and pedogenesis in the area using geochemical and micromorphology proxies. Particle-size distributions were obtained using Malvern Mastersizer; soil geochemistry was determined by XRF and thin sections by routine laboratory procedures. The soils are predominantly sandy (> 94% sand in all samples). The mean phi-values of the soils had little variation suggesting that reworking of sediments upwards in individual profiles produced a more uniform pedogenesis rather than coming from different physical sources. Calcification is the dominant pedogenic process in these alluvial soils. The Chemical Index of Alteration (CIA) proved a more suitable index than Chemical Index of Weathering (CIW) for evaluating weathering in the terraces. The micromass and b-fabrics are mostly granostriated and partly brown mosaic speckled. MISECA values for the degree of soil development range from 4 to 9, which mean weakly to moderately-developed soils. Coarse secondary calcite nodules and coatings are responsible for cementation as observed in pedon 2, which suggests calcium carbonate precipitation from periodical flooding and evaporating groundwater events. The features and diagnostic properties of the soils on the alluvial terraces along the Sabie-Sand River provide evidence for land surface impacts of recent environmental changes in this internationally important conservation area. Precise dating of calcium carbonate precipitates is, however, needed to put the observed evidence into a wider geochronological perspective.

  11. Toxaphene levels in retail food from the Pearl River Delta area of South China and an assessment of dietary intake.

    Science.gov (United States)

    Jiang, YouSheng; Liu, ZhiBin; Wu, DongTing; Zhang, JianQing; Zhou, Jian; Li, ShengNong; Lu, LinGeng; Lin, XiaoShi; Lu, ShaoYou; Peng, JinLing

    2016-06-01

    Limited literature exists on toxaphene contamination in food worldwide, particularly in mainland China. In this study, three toxaphene congeners, Parlar 26 (B8-1413), Parlar 50 (B9-1679) and Parlar 62 (B9-1025), were analyzed in five different food categories from the Pearl River Delta Area in China using isotope dilution high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS), and toxaphene levels in food were reported and toxaphene dietary intake by local residents estimated. The results showed that fish contained the highest toxaphene level with a median of 12.87 pg/g wet weight (ww), followed by poultry meat, egg products, livestock meat and vegetable, which had median levels of 5.8, 2.2, 1.89 and 0.67 pg/g ww, respectively. Parlar 50 and Parlar 26 were the predominant characteristic congeners in fish, and Parlar 26 was the predominant congener not only in poultry products and eggs, but also in livestock and vegetable. The estimated average daily intake found by local residents was 35.57 pg/kg body weight/day. Overall toxaphene levels and estimated dietary intake in the Pearl River Delta Area of South China are far lower than the European Maximum Residue Limits (EU MRLs), the German MRL for fish, and other international literature data. Therefore, the risk of adverse health effects from dietary intakes of toxaphene for the local residents is not considerable at the current time, but follow-ups are warranted to study dynamic changes of toxaphene in food in this area.

  12. Seismic facies of incised-channel fill deposits of paleo-Seomjin River in the South Sea, Korea

    Science.gov (United States)

    Bae, Sung Ho; Kong, Gee Soo; Choul Kim, Dae; Lee, Gwang Soo; Yoo, Dong Geun

    2016-04-01

    High-resolution (Chirp and Sparker system) seismic profiles and piston core samples were analyzed to investigate the depositional environment of paleo-channel in the continental shelf of South Sea. Approximately 1,940 line-km data of chirp and sparker profiles was acquired. Along with seismic profiles, 20 piston core and 10 box core samples collected in 2015. The paleo-channel of Seomjin River is distributed in the continental shelf, with approximately 109 km long, 800-5,000 m wide, and more than 890 km2. The paleo-channel of meandering and straight type is dominant in the inner shelf while changed to braided type in the outer shelf. The paleo-channels in sparker seismic data formed presumably as fluvial systems when the shelf was exposed during the Last Glacial Maximum (LGM). The seismic facies of incision fill divided into five types basis of an erosional surface and internal seismic reflectors: (1) transparent to semi-transparent incised channel fill, (2) parallel to sub-parallel incised channel fill, (3) complex incised channel fill, (4) divergent incised channel fill, and (5) chaotic incised channel fill. The chaotic incised channel fill deposits are consists of gravel with shell fragments in the outer shelf and indicate the LGM to early transgressive (fluvial lag deposits). The complex incised channel fill deposits are dominated by sand and gravel with shell fragments in the mid to outer shelf. The cores which were obtained above the transparent to semi-transparent and parallel to sub-parallel incised channel fill deposits are dominated by mud. These types are dominant in the upstream (inner shelf). The acoustically transparent zones of this type with low-energy, passively infilling depositional environment, suggest the presence of basin muddy deposits. These muddy sediments were likely deposited during a more advanced stage of the Holocene transgression. Thus, the paleo-channel of Seomjin River is strongly controlled by sea-level change and sediment

  13. Soil erosion and sediment yield, a double barrel problem in South Africa's only large river network without a dam

    Science.gov (United States)

    Le Roux, Jay

    2016-04-01

    Soil erosion not only involves the loss of fertile topsoil but is also coupled with sedimentation of dams, a double barrel problem in semi-arid regions where water scarcity is frequent. Due to increasing water requirements in South Africa, the Department of Water and Sanitation is planning water resource development in the Mzimvubu River Catchment, which is the only large river network in the country without a dam. Two dams are planned including a large irrigation dam and a hydropower dam. However, previous soil erosion studies indicate that large parts of the catchment is severely eroded. Previous studies, nonetheless, used mapping and modelling techniques that represent only a selection of erosion processes and provide insufficient information about the sediment yield. This study maps and models the sediment yield comprehensively by means of two approaches over a five-year timeframe between 2007 and 2012. Sediment yield contribution from sheet-rill erosion was modelled with ArcSWAT (a graphical user interface for SWAT in a GIS), whereas gully erosion contributions were estimated using time-series mapping with SPOT 5 imagery followed by gully-derived sediment yield modelling in a GIS. Integration of the sheet-rill and gully results produced a total sediment yield map, with an average of 5 300 t km-2 y-1. Importantly, the annual average sediment yield of the areas where the irrigation dam and hydropower dam will be built is around 20 000 t km-2 y-1. Without catchment rehabilitation, the life expectancy of the irrigation dam and hydropower dam could be 50 and 40 years respectively.

  14. Structured decision making for conservation of bull trout (Salvelinus confluentus) in Long Creek, Klamath River Basin, south-central Oregon

    Science.gov (United States)

    Benjamin, Joseph R.; McDonnell, Kevin; Dunham, Jason B.; Brignon, William R.; Peterson, James T.

    2017-06-21

    With the decline of bull trout (Salvelinus confluentus), managers face multiple, and sometimes contradictory, management alternatives for species recovery. Moreover, effective decision-making involves all stakeholders influenced by the decisions (such as Tribal, State, Federal, private, and non-governmental organizations) because they represent diverse objectives, jurisdictions, policy mandates, and opinions of the best management strategy. The process of structured decision making is explicitly designed to address these elements of the decision making process. Here we report on an application of structured decision making to a population of bull trout believed threatened by high densities of nonnative brook trout (S. fontinalis) and habitat fragmentation in Long Creek, a tributary to the Sycan River in the Klamath River Basin, south-central Oregon. This involved engaging stakeholders to identify (1) their fundamental objectives for the conservation of bull trout, (2) feasible management alternatives to achieve their objectives, and (3) biological information and assumptions to incorporate in a decision model. Model simulations suggested an overarching theme among the top decision alternatives, which was a need to simultaneously control brook trout and ensure that the migratory tactic of bull trout can be expressed. More specifically, the optimal management decision, based on the estimated adult abundance at year 10, was to combine the eradication of brook trout from Long Creek with improvement of downstream conditions (for example, connectivity or habitat conditions). Other top decisions included these actions independently, as well as electrofishing removal of brook trout. In contrast, translocating bull trout to a different stream or installing a barrier to prevent upstream spread of brook trout had minimal or negative effects on the bull trout population. Moreover, sensitivity analyses suggested that these actions were consistently identified as optimal across

  15. Qualitative Interpretation Of Aerogravity And Aeromagnetic Survey Data Over The South Western Part Of The Volta River Basin Of Ghana

    Directory of Open Access Journals (Sweden)

    George Hinson

    2015-04-01

    Full Text Available Abstract The study area South western part of Volta River Basin of Ghana covering an area of 8570 km2 which is one-eleventh the area of the Volta River basin of Ghana has been subjected to numerous academic research works but geophysical survey works because of virtual perceptive reasons. It is now believed to overly mineral-rich geological structures hence the use of magnetic and gravity survey methods to bring out these mineral-rich geological structures.Geographically it study area is located at the south western part of the Voltaian basin at latitudes 07o 00 N and 08o 00 N and longitudes 02o 00 W and 01o 00 W respectively. Airborne gravity and magnetic survey methods were employed in the data collection. The field data correction and error reduction were applied to the two raw data on the field after which Geosoft Oasis Montaj 7.01 Encom Profile Analysis P.A 11 and 13 Model Vision 12 and ArcGIS 10.0 were used to process enhance e.g. reduce to pole at low latitude first vertical derivative etc. model the reduced and corrected airborne magnetic data and also to produce maps from them data. Low-to-moderate-to-high gravity and magnetic anomalies were obtained in the complete Bouguer anomaly CBA and total magnetic intensity TMI reduced to pole at low latitude with many of these anomalies trending NE-SW by which the Birimian Metasediments and Metavolcanics can be said to be part of the causative structures of these anomalies with cross-cut NW-SE faults. From the quantitative point of view the intrusive granitic bodies of the study area have a mean depth location of 1.7 km while the isolated anomaly is located at a depth of 1.4 km computed from Euler deconvolution. The NE-SW trending anomalies show the trend direction of their causative structures which are the basement rocks and the basinal intrusive bodies.

  16. STATIONARITY OF ANNUAL MAXIMUM DAILY STREAMFLOW TIME SERIES IN SOUTH-EAST BRAZILIAN RIVERS

    Directory of Open Access Journals (Sweden)

    Jorge Machado Damázio

    2015-08-01

    Full Text Available DOI: 10.12957/cadest.2014.18302The paper presents a statistical analysis of annual maxima daily streamflow between 1931 and 2013 in South-East Brazil focused in detecting and modelling non-stationarity aspects. Flood protection for the large valleys in South-East Brazil is provided by multiple purpose reservoir systems built during 20th century, which design and operation plans has been done assuming stationarity of historical flood time series. Land cover changes and rapidly-increasing level of atmosphere greenhouse gases of the last century may be affecting flood regimes in these valleys so that it can be that nonstationary modelling should be applied to re-asses dam safety and flood control operation rules at the existent reservoir system. Six annual maximum daily streamflow time series are analysed. The time series were plotted together with fitted smooth loess functions and non-parametric statistical tests are performed to check the significance of apparent trends shown by the plots. Non-stationarity is modelled by fitting univariate extreme value distribution functions which location varies linearly with time. Stationarity and non-stationarity modelling are compared with the likelihood ratio statistic. In four of the six analyzed time series non-stationarity modelling outperformed stationarity modelling.Keywords: Stationarity; Extreme Value Distributions; Flood Frequency Analysis; Maximum Likelihood Method.

  17. PRELIMINARY DISCUSSIONS OF BASIC CLIMATIC CHARAC- TERISTICS OF PRECIPITATION DURING RAINING SEASONS IN REGIONS SOUTH OF CHANGJIANG RIVER AND ITS RELATIONSHIP WITH SST ANOMALIES

    Institute of Scientific and Technical Information of China (English)

    陈绍东; 王谦谦; 钱永甫

    2003-01-01

    Basic climatic characteristics are analyzed concerning the precipitation anomalies in raining seasons over regions south of the Changjiang River (the Yangtze). It finds that the regions are the earliest in eastern China where raining seasons begin and end. Precipitation there tends to decrease over the past 50 years. Waters bounded by 9(S -1(S, 121(E - 129(E are the key zones of SST anomalies that affect the precipitation in these regions over May ~ July in preceding years. Long-term air-sea interactions make it possible for preceding SST anomalies to affect the general circulation that come afterwards, causing precipitation anomalies in the raining seasons in regions south of the Changjiang River in subsequent years.

  18. Variations and net transport of dissolved inorganic nutrients in the South Passage of the Changjiang (Yangtze River) Estuary

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Dissolved inorganic nutrient elements were analyzed from the samples collected in the South Passage of the Changjiang (Yangtze River) Estuary in March 2003, including NH4+, NO3-, NO2- and PO43-. The water samples were collected with a Niskin sampler hourly at the near-surface, middle and near-bottom depths at the three stations-A1, A2 and A3-during two complete tidal cycles of neap tide and spring tide. Results showed that 1) the concentrations of NH4+, NO3- and NO2- were a little higher respectively during the neap tide than those during the spring tide, while PO43- showed an opposite trend, and each was higher in the ebb tide than in the flood tide, either for the neap tidal cycle or the spring tidal cycle; 2) higher stratification of the nutrients existed obviously in this area, with the concentrations of which increased from the bottom to the surface, especially for NH4+ and NO3-; 3) the coefficient of variation (C.V.) values of all dissolved inorganic nutrients varied from 4.06% to 36.8% beyond different influences of the tidal current and Changjiang runoff; 4) with increasing suspended matter in the water column, the concentrations of PO43- became lower in the filtered water; and 5) the total transport of each tidal cycle was much more in the spring tide than in the neap tide, and the positive values indicated that the nutrients had been exported to the East China Sea. Studies on the variations and net transport of dissolved inorganic nutrients in the South Passage of the Changjiang Estuary will provide the scientific basis for the study of the mechanism of red tide in the East China Sea.

  19. Rapid post-rift tectonic subsidence events in the Pearl River Mouth Basin, northern South China Sea margin

    Science.gov (United States)

    He, Min; Zhong, Guangfa; Liu, Xuefeng; Liu, Lihua; Shen, Xinping; Wu, Zhe; Huang, Ke

    2017-10-01

    Data from 26 drill wells and 27 regional seismic profiles were integrated to investigate the timing, phase and origin of the post-rift subsidence in the middle to eastern Pearl River Mouth Basin (PRMB) of the northern South China Sea using the traditional 1-D backstripping technique. Different from previous research of backstripped tectonic subsidence in the basin, we calculated the tectonic subsidence using the newly built local porosity-depth relationships for decompaction and updated sedimentological and paleontological data for paleobathymetry reconstruction. Well-data based subsidence curves reveal a roughly decaying pattern in both the magnitude and rate of the post-rift subsidence in the PRMB, which is in accordance with the general decreasing trend of the thermal subsidence typical of a passive margin. Two events of rapid post-rift tectonic subsidence were identified, which occurred in the Early to early Middle Miocene and the Pliocene. The timing of the first rapid post-rift subsidence event varies and is earlier in the southern rather than northern part of the basin. Additionally, the amplitude of contemporaneous tectonic subsidence is greater in the southern part of the basin. The second rapid tectonic subsidence event occurred simultaneously in both the southern and northern parts of the basin, with the amplitude of subsidence being much greater in the southern part. We associate the first rapid subsidence event with the southward jump of the South China Sea spreading ridge, which occurred between the Oligocene and Early Miocene, while the second event with the arc-continent collision at Taiwan since the latest Late Miocene. The southern PRMB in the deep-water slope area shows a much higher magnitude of tectonic subsidence in both events than its northern counterpart in the shelf area, which could be associated with its much thinner lithosphere. The latter could cause upswelling of denser lower crust and upper mantle material, resulting in more rapid

  20. Fouling in offshore areas southeast of the Zhujiang (Pearl) River Delta, the northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    Yan Tao; Yan Wenxia; Dong Yu; Liang Guanhe; Yan Yan; Wang Huajie

    2003-01-01

    In order to understand the type and extent of marine fouling in offshore areas southeast of the Zhujiang (Pearl) River delta, within the period form May 1986 to June 1987, two biological buoys were deployed at water depths of 95 m and 113 m located in 114 km and 160 km off the coast of Hong Kong, respectively. Moreover, the fouling community of a Marex hydrological buoy located in 115 m depth water 172 km off Hong Kong was also surveyed. The results show that a total of 78 species were collected and identified. The panels exposed for 3 months were mainly dominated by stalked barnacles Conchoderma hunteri and Lepas anatifera and hydroids Orthopyxis sp. As for the buoys, including the subsurface buoy, and their mooring systems exposed for 6 and 12 months, respectively, some hard foulers such as common oysters, pearl oysters, acorn barnacles and bryozoans were also found. The compositions of fouling communities also varied greatly with depth.

  1. Groundwater-flow model for the Wood River Valley aquifer system, south-central Idaho

    Science.gov (United States)

    Fisher, Jason C.; Bartolino, James R.; Wylie, Allan H.; Sukow, Jennifer; McVay, Michael

    2016-06-27

    A three-dimensional numerical model of groundwater flow was developed for the Wood River Valley (WRV) aquifer system, Idaho, to evaluate groundwater and surface-water availability at the regional scale. This mountain valley is located in Blaine County and has a drainage area of about 2,300 square kilometers (888 square miles). The model described in this report can serve as a tool for water-rights administration and water-resource management and planning. The model was completed with support from the Idaho Department of Water Resources, and is part of an ongoing U.S. Geological Survey effort to characterize the groundwater resources of the WRV. A highly reproducible approach was taken for constructing the WRV groundwater-flow model. The collection of datasets, source code, and processing instructions used to construct and analyze the model was distributed as an R statistical-computing and graphics package.

  2. Biological monitoring of Upper Three Runs Creek, Savannah River Plant, Aiken County, South Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Specht, W.L.

    1991-10-01

    In anticipation of the fall 1988 start up of effluent discharges into Upper Three Creek by the F/H Area Effluent Treatment Facility of the Savannah River Site, Aiken, SC, a two and one half year biological study was initiated in June 1987. Upper Three Runs Creek is an intensively studied fourth order stream known for its high species richness. Designed to assess the potential impact of F H area effluent on the creek, the study includes qualitative and quantitative macroinvertebrate stream surveys at five sites, chronic toxicity testing of the effluent, water chemistry and bioaccumulation analysis. This final report presents the results of both pre-operational and post-operational qualitative and quantitative (artificial substrate) macroinvertebrate studies. Six quantitative and three qualitative studies were conducted prior to the initial release of the F/H ETF effluent and five quantitative and two qualitative studies were conducted post-operationally.

  3. Detrital Zircon Ages of Hanjiang River:Constraints on Evolution of Northern Yangtze Craton, South China

    Institute of Scientific and Technical Information of China (English)

    Yang Jie; Gao Shan; Yuan Honglin; Gong Hujun; Zhang Hong; Xie Shiwen

    2007-01-01

    Clastic sedimentary rocks are natural samples of the exposed continental crust over large ideal sample for studying the formation and evolution of the northern Yangtze craton. Here we report laser ablation inductively coupled plasma mass spectrometer U-Pb ages of 122 detrital zircons from one sand sample of the Hanjiang River. The 110 concordant zircons reveal four major age groups of 768,444, 212, and 124 Ma, which well correlate with known magmatic events in the northern Yangtze craton. A minor group is present at 1 536 Ma, which is less known in the study area. Only seven zircons have ages of >1 750 Ma. Our results show that the Early Paleozoic, Late Triassic, and Early Cretaceous are important episodes of zircon growth and crustal growth/reworking in addition to the previously documented Neoproterozoic event. Our results suggest very limited exposures of Paleoproterozoic and Archean rocks in the northern parts of the Yangtze craton.

  4. TDS-Eh graph analysis: a new water quality index and rural water supply implications of a river affected by mining in south-eastern Nigeria

    Institute of Scientific and Technical Information of China (English)

    I.C.EZEKWE; A.O.AISUBEOGUN; G.N.CHIMA; E.ODUBO

    2012-01-01

    The Ivo River Basin of south-eastern Nigeria is a water scarce and mining region,which suffers from water scarcity.The influence of mining activities on the quality of the Ivo River and its capacity for community water supply was investigated.Also the efficacy of TDS-Eh graph in explaining water quality was presented.Results indicated that the TDS-Eh graph highlights subtle chemical relationships which control water quality and provide a simple but generic pollution index for rapid water quality assessment.It was also discovered that the Ivo River could become an adequate alternative to groundwater as a source of rural water supply in the study area with an estimated average daily discharge of 6726000L and a rural population of less than 200000 persons.The Ivo River meets the WHO drinking water standards in 20 physicochemical water quality paramcters (pH,temperature,conductivity,turbidity,salinity,TDS,Eh,alkalinity,chloride,nitrate,sulfate,phosphate,calcium,magnesium,iron,manganese,zinc,lead and cadmium) analyzed and can therefore (with little treatment) provide up to 133.4% of average community water demand and 83.8% of maximum community water demand.The.impact of mining on Ivo River quality was found to have been moderated by the presence of carbonate rocks which may have enhanced the precipitation of heavy metals from the river.

  5. TDS-Eh graph analysis: a new water quality index and rural water supply implications of a river affected by mining in south-eastern Nigeria

    Science.gov (United States)

    Ezekwe, I. C.; Aisubeogun, A. O.; Chima, G. N.; Odubo, E.

    2012-03-01

    The Ivo River Basin of south-eastern Nigeria is a water scarce and mining region, which suffers from water scarcity. The influence of mining activities on the quality of the Ivo River and its capacity for community water supply was investigated. Also the efficacy of TDS-Eh graph in explaining water quality was presented. Results indicated that the TDS-Eh graph highlights subtle chemical relationships which control water quality and provide a simple but generic pollution index for rapid water quality assessment. It was also discovered that the Ivo River could become an adequate alternative to groundwater as a source of rural water supply in the study area with an estimated average daily discharge of 6726000 L and a rural population of less than 200000 persons. The Ivo River meets the WHO drinking water standards in 20 physicochemical water quality parameters (pH, temperature, conductivity, turbidity, salinity, TDS, Eh, alkalinity, chloride, nitrate, sulfate, phosphate, calcium, magnesium, iron, manganese, zinc, lead and cadmium) analyzed and can therefore (with little treatment) provide up to 133.4% of average community water demand and 83.8% of maximum community water demand. The impact of mining on Ivo River quality was found to have been moderated by the presence of carbonate rocks which may have enhanced the precipitation of heavy metals from the river.

  6. Adaptive management and water temperature variability within a South African river system: what are the management options?

    Science.gov (United States)

    Rivers-Moore, N A; Jewitt, G P W

    2007-01-01

    Water temperatures, and in particular daily maximum water temperatures, are a critical water quality parameter. An understanding of associated resource management issues, including links between water temperature variability and aquatic diversity values, should be part of any management programme that considers river systems. Simple rule-based models have been shown to be appropriate tools within an adaptive management approach, both because of their heuristic value and in their application for scenario generation. Such a model was developed to simulate changes in the condition factor of Chiloglanis anoterus [Crass, R.S., 1960. Notes on the freshwater fishes of Natal with descriptions of 4 new species. Annals of the Natal Museum 14, 405-458] (Pisces: Mochokidae) in response to annual frequency of exceedance of a threshold temperature under three broad environmental scenarios for part of the Sabie River falling within South Africa's Kruger National Park. This model has potential for application within the adaptive management programme being implemented by the Kruger National Park. Results show that under broad scenarios of a 10% reduction in mean daily flow rates, or a 2 degrees C increase in mean daily air temperatures, system variability is likely to increase relative to reference conditions . It is suggested that so-called "thresholds of probable concern" (TPCs), which are based on current levels of "natural" system variability, are useful as management targets for achieving a "desired future state" for the river system. The model, recognised as a preliminary hypothesis, highlights a lack of knowledge regarding the nature of system variability, and the correspondingly wide confidence limits of the proposed TPC restricts its utility in a short-term management context. Thus, it is now recognised that its value lies more in its use as a long-term modelling tool to reflect water temperature responses to flow variability. This highlights the fact that research

  7. [Distribution Characteristics and Risk Assessment of Phthalic Acid Esters in Agricultural Products Around the Pearl River Delta. South China].

    Science.gov (United States)

    Li, Bin; Wu, Shan; Liang, Jin-ming; Deng, Jie-fan; Wang, Ke; Liang, Wen-li; Zeng, Cai-ming; Peng, Si-qing; Zhang, Tian-bin; Yang, Guo-yi

    2016-01-15

    In order to investigate and assess the distribution of pathalic acid easters (PAEs) in agricultural products from typical areas of the Pearl River Delta, South China, 131 agricultural products were sampled for determination of 6 PAEs priority pollutants classified by the U. S. EPA by GC-FID. The results showed that the total contents of the PAEs (sigma PAEs) in agricultural products samples ranged from nd to 79.86 mg x kg(-1) and the mean value was 2.84 mg x kg(-1), with the detected ratio of 98.5%. The average concentrations of sigma PAEs in different types of agricultural products were ordered by vegetables (3.03 mg x kg(-1)) > rice (2.52 mg x kg(-1)) > fruits (1.26 mg x kg(-1)). The mean concentration of PAEs distributed in the four typical cities of the Pearl River Delta, and decreased in the sequence of Zhuhai (6.53 mg x kg(-1)) > Dongguan (2.59 mg x kg(-1)) > Huizhou (1.53 mg x kg(-1)) > Zhongshan (1.12 mg x kg(-1)). Di-n-butyl phthalate (DBP), di-(2-ethylhexyl) phthalate (DEHP) and di-n-octyl phthalate (DnOP) contributed more than 90. 8% of the total PAEs in samples, and were the main components of PAEs in agricultural products from the Pearl River Delta, with higher percentage contents and detected ratio. Meanwhile, the average concentrations of sigma PAEs in cabbage mustard, lettuce occurred in Zhuhai and Dongguan cities, followed by lettuce and leaf lettuce in the corresponding DEHP from Zhuhai city, both exceeded the suggested standards in U.S.A. and Europe and were of high health risk. There were significant differences among 14 various vegetables in the contents of the 6 PAEs compounds, and the sigma PAEs contents in cabbage mustard and lettuce as part of leafy vegetables were higher than those in other vegetables, while the lowest were detected in flowering cabbage and edible amaranth. Therefore, the type of vegetables and its growing environment exposed to the atmosphere and soil were the main factors that significantly affected their accumulation of

  8. Quality of groundwater and surface water, Wood River Valley, south-central Idaho, July and August 2012

    Science.gov (United States)

    Hopkins, Candice B.; Bartolino, James R.

    2013-01-01

    Residents and resource managers of the Wood River Valley of south-central Idaho are concerned about the effects that population growth might have on the quality of groundwater and surface water. As part of a multi-phase assessment of the groundwater resources in the study area, the U.S. Geological Survey evaluated the quality of water at 45 groundwater and 5 surface-water sites throughout the Wood River Valley during July and August 2012. Water samples were analyzed for field parameters (temperature, pH, specific conductance, dissolved oxygen, and alkalinity), major ions, boron, iron, manganese, nutrients, and Escherichia coli (E.coli) and total coliform bacteria. This study was conducted to determine baseline water quality throughout the Wood River Valley, with special emphasis on nutrient concentrations. Water quality in most samples collected did not exceed U.S. Environmental Protection Agency standards for drinking water. E. coli bacteria, used as indicators of water quality, were detected in all five surface-water samples and in two groundwater samples collected. Some analytes have aesthetic-based recommended drinking water standards; one groundwater sample exceeded recommended iron concentrations. Nitrate plus nitrite concentrations varied, but tended to be higher near population centers and in agricultural areas than in tributaries and less populated areas. These higher nitrate plus nitrite concentrations were not correlated with boron concentrations or the presence of bacteria, common indicators of sources of nutrients to water. None of the samples collected exceeded drinking-water standards for nitrate or nitrite. The concentration of total dissolved solids varied considerably in the waters sampled; however a calcium-magnesium-bicarbonate water type was dominant (43 out of 50 samples) in both the groundwater and surface water. Three constituents that may be influenced by anthropogenic activity (chloride, boron, and nitrate plus nitrite) deviate from this

  9. Geology and stratigraphy of the Challis Volcanic Group and related rocks, Little Wood River area, south-central Idaho

    Science.gov (United States)

    Sandford, Richard F.; Snee, Lawrence W.

    2005-01-01

    The southwestern part of the Challis volcanic field occupies the valley of the Little Wood River and its tributaries in the Hailey and Idaho Falls 1??2? quadrangles of south-central Idaho. The Little Wood River area is a structurally controlled topographic basin that is partly filled by Eocene Challis Volcanic Group and younger rocks. Rock types in the Challis Volcanic Group of the Little Wood River area include, in order of decreasing abundance, andesite lava flows and tuff breccia, dacite lava flows and flow breccia, volcaniclastic sedimentary rocks, lithic tuff, nonvolcanic conglomerate, and rhyolite dikes. A basal nonvolcanic conglomerate, that locally rests on upper Paleozoic sedimentary rocks at a regional unconformity, was deposited prior to eruption of volcanic rocks. Andesite was the first volcanic rock erupted and is a voluminous sequence as thick as 3,000 ft (1,000 m). Locally thick volcaniclastic sedimentary rocks accumulated in topographic lows. A sharp transition marks the beginning of dacite eruption from fissures and flow-dome complexes. Dacite flows and breccias are as thick as 2,000 ft (600 m). An upper volcaniclastic unit was deposited in paleotopographic lows following emplacement of the main dacite unit. Next, a widespread, distinctive, lithic rich ash flow tuff, correlated with the tuff of Stoddard Gulch, was deposited over much of the area. Deposition of the tuff was followed by eruption of thin andesite and dacite lava flows and deposition of conglomeratic sedimentary rocks. The entire sequence was then intruded by a dacite flow-dome complex composed of at least three separate intrusions. The Challis Volcanic Group in the study area is calcalkaline. Andesitic rocks are typically high potassium basaltic andesite, high potassium andesite, shoshonite, and banakite (latite). Dacitic rocks are high potassium dacite and trachyte. Tuffs and vitrophyres range in composition from basaltic andesite to trachyte. The paleotopographic basin in which the

  10. Biogeochemical study of water and bottom sediments from the Khai river - Nha Trang Bay estuarine system, South China Sea

    Science.gov (United States)

    Shulga, Natalia; Lobys, Nikolay; Drozdova, Anastasia; Peresypkin, Valery

    2014-05-01

    The present study was carried out in Nha Trang Bay (Southern Vietnam, the South China Sea). The samples of water, suspended matter and bottom sediments were collected in summer 2010-2012 in section from the estuary of the Khai River to the marine part of the bay. The samples were analyzed in the stationary lab of IO RAS, Moscow, by TOC-V-CPH, GC/MS and pirolysis methods. We report here the novel data on sources, transformation and burial of OM coming from the Khai river waters. The investigation is focused on ontent and distribution of suspended matter (SM) in the estuary, dissolved organic carbon (DOC), particulated organic carbon (POC); molecular and group composition of hydrocarbons (n-alkanes, steranes, hopanes) and mercury content in water, SM and bottom sediments. It was found that concentration of POC and SM decrease in the Nha Trang Bay waters from estuary to the open part of the bay. However, major changes in the concentration of SM and POC belong to the zone of salinity gradient.DOC behavior is more stable throughout the study area. Organic-geochemical indicators estimation allowed recognition of genesis and transformation degree of organic matter in the study area. The estuary is characterized by mixed genesis of SM with a predominance of allochthonous organic matter whereas outlying parts of the Nha Trang bay are characterized by autochthonous OM. Composition of OM in sediments reflects regularities identified above, despite of the interannual and seasonal variability in the study area. The investigation reveals a predominance of terrestrial organic matter in the silt sediments of the estuary, transported by the Khai river. Distribution of OM in sediments of marine part of the bay is mosaic, with a predominance of planktonogenic, bacterial or terrestrial input at their complex combination. Local anthropogenic pollution as well as an impact of industrial city effluents are found in river- and seaport areas. According to obtained data sedimentation rate

  11. River

    Directory of Open Access Journals (Sweden)

    Morel Mathieu

    2016-01-01

    Full Text Available The OECD report “Boosting Resilience through Innovative Risk Governance” examines the efforts of OECD countries to prevent or reduce future disaster impacts, and highlights several key areas where improvements can be made. International collaboration is insufficiently utilised to address shocks that have increasingly global consequences. Institutional design plays a significant role in facilitating or hampering the engagement and investments of governmental and non-governmental stakeholders in disaster risk prevention and mitigation. To inform the design of “better” institutions, the OECD proposes the application of a diagnostic framework that helps governments identify institutional shortcomings and take actions to improve them. The goal of the case study on the Rhone River is to conduct an analysis of the progress, achievements and existing challenges in designing and implementing disaster risk reduction strategies through the Rhone Plan from a comparative perspective across a set of selected countries of this study, like Austria and Switzerland, will inform how to improve institutional frameworks governing risk prevention and mitigation. The case study will be used to identify examples of successful practice taking into account their specific country contexts, and analyse their potential for policy transfer.

  12. Assessment of water quality, nutrients, algal productivity, and management alternatives for low-flow conditions, South Umpqua River basin, Oregon, 1990-92

    Science.gov (United States)

    Tanner, Dwight Q.; Anderson, Chauncey W.

    1996-01-01

    This report is an evaluation of the effects of nutrient loading on water quality in the South Umpqua River Basin. The study was done by the U.S. Geological Survey in cooperation with Douglas County, Oregon. Five wastewater-treatment plants were shown to contribute less than 15 percent of the flow, but more than 90 percent of the nitrogen and phosphorus, in the South Umpqua River during low streamflows in summer. These nutrient inputs were associated with, and largely responsible for, the dense growth of periphytic algae that covered the rocky channel and produced biomass values as large as 340 grams of ash-free dry weight per square meter. The nighttime respiration of periphytic algae caused violations of the Oregon water-quality standard, which requires a dissolved oxygen concentration of at least 90 percent of saturation, at most sites along the South Umpqua River. Photosynthesis by algae during daylight resulted in many exceedances of the Oregon pH standard of 8.5.

  13. Simulation of streamflow and the effects of brush management on water yields in the upper Guadalupe River watershed, south-central Texas, 1995-2010

    Science.gov (United States)

    Bumgarner, Johnathan R.; Thompson, Florence E.

    2012-01-01

    The U.S. Geological Survey, in cooperation with the Texas State Soil and Water Conservation Board and the Upper Guadalupe River Authority, developed and calibrated a Soil and Water Assessment Tool watershed model of the upper Guadalupe River watershed in south-central Texas to simulate streamflow and the effects of brush management on water yields in the watershed and to Canyon Lake for 1995–2010. Model simulations were done to quantify the possible change in water yield of individual subbasins in the upper Guadalupe River watershed as a result of the replacement of ashe juniper (Juniperus ashei) with grasslands. The simulation results will serve as a tool for resource managers to guide their brush-management efforts.

  14. Occurrence and transport of 17 perfluoroalkyl acids in 12 coastal rivers in south Bohai coastal region of China with concentrated fluoropolymer facilities.

    Science.gov (United States)

    Wang, Pei; Lu, Yonglong; Wang, Tieyu; Fu, Yaning; Zhu, Zhaoyun; Liu, Shijie; Xie, Shuangwei; Xiao, Yang; Giesy, John P

    2014-07-01

    Perfluoroalkyl acids (PFAAs) are emerging contaminants that have raised great concern in recent years. While PFAAs manufacturing becomes regulated in developed countries, production has been partly shifted to China. Eight fluoropolymer manufacturing facilities located in the South Bohai coastal region, one of the most populated areas of China, have been used to manufacture PFAA-related substances since 2001. The environmental consequence of the intensive production of PFAAs in this region remains largely unknown. We analyzed 17 PFAAs in twelve coastal rivers of this region, and found staggeringly high concentrations of perfluorooctanoic acid (PFOA) ranging from 0.96 to 4534.41 ng/L. The highest concentration was observed in the Xiaoqing River which received effluents from certain fluoropolymer facilities. Principal component analysis indicated similar sources of several perfluoroalkyl carboxylic acids (PFCAs) in all rivers, which indicated that atmospheric transport, wastewater treatment and surface runoff also acted as important supplements to direct discharge to surface water.

  15. Hydrostratigraphy of the General Separations Area, Savannah River Site (SRS), South Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Aadland, R.K.; Harris, M.K.; Lewis, C.M.; Gaughan, T.F. (Westinghouse Savannah River Co., Aiken, SC (United States)); Westbrook, T.M. (Dames and Moore, Atlanta, GA (United States))

    1991-01-01

    Detailed analysis and synthesis of geophysical, core, and hydrologic data from 230 wells were used to delineate the hydrostratigraphy and aquifer characteristics of the General Separations Area at SRS. The study area is hydrologically bounded on the north and northwest by Upper Three Runs Creek (UTRC) and on the south by Fourmile Branch (FB). The Cretaceous-Tertiary sedimentary sequence underlying the study area is divided into two Aquifer Systems; in ascending order, Aquifer Systems I and 11. The study concentrated on Aquifer System U, which includes all the Tertiary sediments above the Black Mingo Group (Paleocene) to the water table. This report includes a series of lithostratigraphic cross-sections, piezometric gradient profiles, head ratio contour maps, aquifer isopach maps, and potentiometric surface maps which illustrate the aquifer characteristics of the study area.

  16. Potential submarine geologic hazards at the entrance of the Pearl River Estuary in the northern South China Sea

    Science.gov (United States)

    Zhang, Zhiqiang; Wei, Zhiqiang; He, Huizhong; Wei, Wei; Qian, Libing; Li, Tuanjie

    2016-08-01

    The potential submarine geologic hazards were distinguished and categorized at the entrance of the Pearl River Estuary in the northern South China Sea, based upon the analysis of side scan sonar and sub-bottom profiler surveying data of about 2500 km long, in an area about 2000 km2 around the Wanshan Archipelago. The data obtained in the survey has the highest spatial resolution by far, which could reveal more detailed distributions and characteristics of the geologic hazards than before. In the study region, three paleo-channels that were buried about 10-30 m below the seabed were found; more than 10 shallow gas areas were discovered. The sand waves found in the region were generally small and located near the islands, and twenty pockmarks found on the seabed were mostly concentrated to north of Zhuzhou island. There are also many man-made obstacles in the region, such as wreckages, pipeline, etc. In this paper we provide a detailed distribution map of the submarine geologic hazards in this region for the first time, and discuss their formation and harmfulness, which will provide a scientific basis for marine engineering construction, marine geologic disaster prevention and mitigation.

  17. Characterizing ionic species in PM2.5 and PM10 in four Pearl River Delta cities, South China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    PM2.5 and PM10 samples were collected at four major cities in the Pearl River Delta (PRD), South China, during winter and summer in 2002. Six water-soluble ions, Na+, NH4+, K+, Cl-, NO3- and SO42- were measured using ion chromatography. On average, ionic species accounted for 53.3% and 40.5% for PM2.5 and PM10, respectively in winter and 39.4% and 35.2%, respectively in summer. Secondary ions such as sulfate, nitrate and ammonium accounted for the major part of the total ionic species. Sulfate was the most abundant specie followed by nitrate. Overall, a regional pollution tendency were shown in this campaign though there were higher concentrations of sulfate, nitrate and ammonium measured in Guangzhou City than those in the other PRD cities. Significant seasonal variations were also observed with higher levels of species in winter and lower in summer. The Asian monsoon system was favorable for removal and diffusion of air pollutants in PRD in summer while highly loading of local industrial emissions tended to deteriorate the air quality as well. NO3-/SO42- ratio indicates that mobile sources have considerably contribution to the urban aerosol but stationary sources should still not be neglected. Besides the primary emissions, complex atmospheric reactions under favorable weather conditions should be paid more attention for formulating control strategies for primary emission in the future in the PRD region.

  18. Spatial and Vertical Distribution of Dechlorane Plus in Mangrove Sediments of the Pearl River Estuary, South China.

    Science.gov (United States)

    Sun, Yu-Xin; Zhang, Zai-Wang; Xu, Xiang-Rong; Hao, Qin-Wei; Hu, Yong-Xia; Zheng, Xiao-Bo; Luo, Xiao-Jun; Diao, Zeng-Hui; Mai, Bi-Xian

    2016-10-01

    Thirty surface sediments and three sediment cores were collected from mangrove wetlands in the Pearl River Estuary of South China to investigate the spatial and vertical distribution of Dechlorane Plus (DP). DP concentrations in the mangrove surface sediments ranged from 0.0130 to 1.504 ng/g dry weight (dw). DP concentrations in sediments from Shenzhen were significantly greater than those from Guangzhou and Zhuhai. Anti-Cl11-DP, the dechlorinated product of anti-DP, was also detected in the mangrove sediments with concentrations ranged from not detected to 0.0198 ng/g dw. Significant positive relationship between anti-Cl11-DP and anti-DP levels was observed in the mangrove sediments, suggesting that photo and/or microbial degradation of anti-DP might occur in the sediments. The f anti values in the mangrove sediments were close to those in the technical DP products, suggesting that stereoselective enrichment of anti-DP may not exist in the mangrove sediments. DP concentrations in the mangrove sediment cores generally showed an increasing trend from the bottom to top layers. This is the first study to report the occurrence of DP and its degradation product in the mangrove wetlands.

  19. Metabolic and phylogenetic profile of bacterial community in Guishan coastal water (Pearl River Estuary), South China Sea

    Science.gov (United States)

    Hu, Xiaojuan; Liu, Qing; Li, Zhuojia; He, Zhili; Gong, Yingxue; Cao, Yucheng; Yang, Yufeng

    2014-10-01

    Characteristics of a microbial community are important as they indicate the status of aquatic ecosystems. In the present study, the metabolic and phylogenetic profile of the bacterioplankton community in Guishan coastal water (Pearl River Estuary), South China Sea, at 12 sites (S1-S12) were explored by community-level physiological profiling (CLPP) with BIOLOG Eco-plate and denaturing gradient gel electrophoresis (DGGE). Our results showed that the core mariculture area (S6, S7 and S8) and the sites associating with human activity and sewage discharge (S11 and S12) had higher microbial metabolic capability and bacterial community diversity than others (S1-5, S9-10). Especially, the diversity index of S11 and S12 calculated from both CLPP and DGGE data ( H>3.2) was higher than that of others as sewage discharge may increase water nitrogen and phosphorus nutrient. The bacterial community structure of S6, S8, S11 and S12 was greatly influenced by total phosphorous, salinity and total nitrogen. Based on DGGE fingerprinting, proteobacteria, especially γ- and α-proteobacteria, were found dominant at all sites. In conclusion, the aquaculture area and wharf had high microbial metabolic capability. The structure and composition of bacterial community were closely related to the level of phosphorus, salinity and nitrogen.

  20. Microcrustaceans (Branchiopoda and Copepoda) of Wetland Ponds and Impoundments on the Savannah River Site, Aiken, South Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Adrienne E. DeBiase; Barbara E. Taylor

    2005-09-21

    The United States Department of Energy's Savannah River Site (SRS) in Aiken, Allendale, and Barnwell Counties, South Carolina, contains an abundance of freshwater wetlands and impoundments. Four large impoundments, as well as several small, abandoned farm and mill ponds, and about 400 Carolina bays and other small, isolated depression wetland ponds are located within the 893 km2 area of the SRS. Crustaceans of the orders Branchiopoda and Copepoda are nearly ubiquitous in these water bodies. Although small in size, these organisms are often very abundant. They consequently play an important trophic role in freshwater food webs supporting fish, larval salamanders, larval insects, and numerous other animals, aquatic and terrestrial. This report provides an introduction to the free-living microcrustaceans of lentic water bodies on the SRS and a comprehensive list of species known to occur there. Occurrence patterns are summarized from three extensive survey studies, supplemented with other published and unpublished records. In lieu of a key, we provide a guide to taxonomic resources and notes on undescribed species. Taxa covered include the orders Cladocera, Anostraca, Laevicaudata, and Spinicaudata of the Subclass Branchiopoda and the Superorders Calanoida and Cyclopoida of Subclass Copepoda. Microcrustaceans of the Superorder Harpacticoida of the Subclass Copepoda and Subclass Ostracoda are also often present in lentic water bodies. They are excluded from this report because they have not received much study at the species level on the SRS.

  1. Reservoir storage and hydrologic responses to droughts in the Paraná River basin, south-eastern Brazil

    Science.gov (United States)

    Melo, Davi de C. D.; Scanlon, Bridget R.; Zhang, Zizhan; Wendland, Edson; Yin, Lei

    2016-11-01

    Droughts are particularly critical for Brazil because of impacts on water supply and because most (70 %) of its electricity is derived from hydroelectric generation. The Paraná basin (PB), a major hydroelectric producing region with 32 % (60 million people) of Brazil's population, recently experienced the most severe drought since the 1960s, compromising the water supply for 11 million people in São Paulo. The objective of this study is to quantify linkages between meteorological and hydrological droughts based on remote sensing, modelling, and monitoring data using the Paraná River basin in south-eastern Brazil as a case study. Two major meteorological droughts were identified in the early 2000s and 2014, with precipitation 20-50 % below the long-term mean. Total water storage change estimated from the Gravity Recovery and Climate Experiment (GRACE) satellites declined by 150 km3 between April 2011 and April 2015. Simulated soil moisture storage declined during the droughts, resulting in decreased runoff into reservoirs. As a result, reservoir storage decreased by 30 % relative to the system's maximum capacity, with negative trends ranging from 17 (May 1997-April 2001) to 25 km3 yr-1 (May 2011-April 2015). Storage in upstream reservoirs is mostly controlled by natural climate forcing, whereas storage in downstream reservoirs also reflects dam operations. This study emphasizes the importance of integrating remote sensing, modelling, and monitoring data to evaluate droughts and to establish a preliminary understanding of the linkages between a meteorological and hydrological drought for future management.

  2. Spatial trend and pollution assessment of total mercury and methylmercury pollution in the Pearl River Delta soil, South China.

    Science.gov (United States)

    Chen, Laiguo; Xu, Zhencheng; Ding, Xiaoyong; Zhang, Weidong; Huang, Yumei; Fan, Ruifang; Sun, Jiaren; Liu, Ming; Qian, Donglin; Feng, Yongbin

    2012-07-01

    Total mercury (THg) and methylmercury (MeHg) were measured in large number of soil samples collected from areas with different types of land use, different depth in the Pearl River Delta (PRD) of South China. THg and MeHg concentrations ranged from 16.7 to 3320ngg(-1) and 0.01 to 1.34ngg(-1), respectively. THg levels are highest in the top 0-20cm soil layer, and decrease from the surface to bottom layer soil. Spatial variation was observed with different types of land use. Urban parks had the highest concentrations and the other areas tended to decrease in the order of residential areas, industrial areas, vegetable fields, cereal fields, and woodlands. Temporal variation was also noted, and two relatively high THg contamination zones located in the northwestern part of the PRD have significantly expanded over the last two decades. Both THg and MeHg concentrations were correlated significantly with soil organic matter (OM), but not with soil pH. THg pollution status was evaluated using two assessment methods.

  3. Using mercury isotopes to understand the bioaccumulation of Hg in the subtropical Pearl River Estuary, South China.

    Science.gov (United States)

    Yin, Runsheng; Feng, Xinbin; Zhang, Junjun; Pan, Ke; Wang, Wenxiong; Li, Xiangdong

    2016-03-01

    Coastal and estuarine regions are important areas of mercury pollution. Therefore, it is important to properly characterize the sources and bioaccumulation processes of mercury in these regions. Here, we present mercury stable isotopic compositions in 18 species of wild marine fish collected from the Pearl River Estuary (PRE), south China. Our results showed variations in mass-independent fractionation (Δ(199)Hg: +0.05 ± 0.10‰ to +0.59 ± 0.30‰) with a Δ(199)Hg/Δ(201)Hg of ∼1.26, suggesting that aqueous MeHg underwent photo-degradation prior to incorporation into the food chain. For the results, we discovered small but significant differences of Δ(199)Hg values among herbivorous, demersal, and carnivorous fish, indicating that different feeding guilds of fish may have incorporated MeHg with various degrees of photo-demethylation. The consistent mercury isotope compositions between fish feeding habitat and mercury sources in the estuary provide potentially important findings on the transformation and bioaccumulation of this toxic metal in subtropical coastal environments.

  4. Projected Hg dietary exposure of 3 bird species nesting on a contaminated floodplain (South River, Virginia, USA).

    Science.gov (United States)

    Wang, Jincheng; Newman, Michael C

    2013-04-01

    Dietary Hg exposure was modeled for Carolina wren (Thryothorus ludovicianus), Eastern song sparrow (Melospiza melodia), and Eastern screech owl (Otus asio) nesting on the contaminated South River floodplain (Virginia, USA). Parameterization of Monte-Carlo models required formal expert elicitation to define bird body weight and feeding ecology characteristics because specific information was either unavailable in the published literature or too difficult to collect reliably by field survey. Mercury concentrations and weights for candidate food items were obtained directly by field survey. Simulations predicted the probability that an adult bird during breeding season would ingest specific amounts of Hg during daily foraging and the probability that the average Hg ingestion rate for the breeding season of an adult bird would exceed published rates reported to cause harm to other birds (>100 ng total Hg/g body weight per day). Despite the extensive floodplain contamination, the probabilities that these species' average ingestion rates exceeded the threshold value were all <0.01. Sensitivity analysis indicated that overall food ingestion rate was the most important factor determining projected Hg ingestion rates. Expert elicitation was useful in providing sufficiently reliable information for Monte-Carlo simulation.

  5. Assessment of water quality in the South Indian River Water Control District, Palm Beach County, Florida, 1989-94

    Science.gov (United States)

    Lietz, A.C.

    1996-01-01

    A study was conducted to assess ground-water and surface-water quality in the South Indian River Water Control District in northern Palm Beach County from 1989 to 1994. Contamination of the surficial aquifer system and availability of a potable water supply have become of increasing concern. The study consisted of sampling 11 ground-water wells and 14 surface- water sites for determination of major inorganic constituents and physical characteristics, trace metals, nitrogen and phosphorus species, and synthetic organic compounds. Sodium and chloride concentrations exceeded Florida drinking-water standards in ground water at two wells, dissolved- solids concentrations at five ground-water wells and one surface-water site, and color values at all 11 ground-water wells and all 14 surface-water sites. Other constituents also exhibited concentrations that exceeded drinking-water standards. Cadmium and zinc concentrations exceeded the standards in ground water at one well, and lead concentrations exceeded the standard in ground water at five wells. Nitrogen and phosphorus specie concentrations did not exceed respective drinking-water standards in any ground-water or surface-water samples. Several synthetic organic compounds were detected at or above 50 micrograms per liter in water samples collected from six ground-water wells and three surface-water sites.

  6. Arsenopyrite in the bank deposits of the Whitewood Creek-Belle Fourche-Cheyenne River-Lake Oahe system, South Dakota, U.S.A.

    Science.gov (United States)

    Horowitz, A.J.; Elrick, K.A.; Cook, R.B.

    1990-01-01

    Mining, milling, and processing wastes containing quantities of arsenopyrite were produced around Lead, South Dokata, from 1875 to 1977. Much of this material was discharged into Whitewood Creek, and from there portions of the waste were transported to the Belle Fourche River, thence to the Cheyenne River, and finally to the Missouri River. In 1958, the Missouri River was dammed at Pierre, forming Lake Oahe. Analyses of cores collected from the lake bottom showed the presence of arsenic-rich layers in the bed sediments; substantial portions of the arsenic are due to arsenopyrite in the 8-16 and 16-32 ??m size fractions of the sediments. In addition, suspended-sediment samples collected from the Cheyenne River above Lake Oahe contain detectable quantities of arsenopyrite in the 8-16 and 16-32 ??m fractions. Solid material collected from the banks and floodplains of the Belle Fourche River and Whitewood Creek contains reduced and oxidized phases. The reduced phases have arsenic maxima in the 16-32 and 32-63 ??m size ranges. These fractions also contribute the most arsenic to the samples; the major source being arsenopyrite. The oxidized segments have arsenic maxima in the 63 ??m size ranges. The 63 ??m fractions contribute the most arsenic to the oxidized samples. This arsenic, despite the oxidized nature of the samples, is associated with arsenopyrite coated with thin iron oxide rinds. It has been calculated that 80% of the arsenic in these deposits is associated with sulfides (in the form of arsenopyrite), while 20% is associated with iron oxides. The arsenopyrite found in the banks and floodplains of Whitewood Creek and the Belle Fourche River are the likely source of the arsenopyrite found in the suspended sediments of the Cheyenne River and in the bed sediment of Lake Oahe.

  7. Ground-water resources of the South Platte River Basin in western Adams and southwestern Weld Counties, Colorado

    Science.gov (United States)

    Smith, Rex O.; Schneider, P.A.; Petri, Lester R.

    1964-01-01

    The area described in this report consists of about 970 square miles in western Adams and southwestern Weld Counties in northeastern Colorado. It includes that part of the South Platte River valley between Denver and Kuner, Colo., all of Beebe Draw, and the lower part of the valley of Box Elder Creek. The stream-valley lowlands are separated by rolling uplands. The climate is semiarid, the normal annual precipitation being about 13 inches; thus, irrigation is essential for stable agricultural development. The area contains about 220,000 acres of irrigated land in the stream valleys. Most of the remaining 400,000 acres of land is used for dry farming or grazing because it lacks irrigation water. Most of the lowlands were brought under irrigation with surface water during the early 1900's, and now nearly all the surface water in the area is appropriated for irrigation within and downstream from the area. Because the natural flow of the streams is sometimes less than the demand for water, ground water is used to supplement the surface-water supply. Wells, drilled chiefly since 1930, supply the supplemental water and in some places are the sole supply for irrigation use. Rocks exposed in the area are of sedimentary origin and range in age from Lato Cretaceous to Recent. Those that are consolidated, called 'bedrock' in this report, consist of the Fox Hills sandstone and the Laramie and Arapahoe formations, all of Late Cretaceous age, and the Denver formation and Dawson arkose of Late Cretaceous and Tertiary age. The surface of the bedrock was shaped by ancestral streams, the valleys of which are reflected by the present surface topography. Dune sand, slope wash, and thin upland deposits of Quaternary age mantle the bedrock in the divide areas, and stream deposits ranging in thickness from 0 to about 125 feet partly fill the ancestral valleys. The valley-fill deposits consist of beds and lenses of clay, silt, sand, gravel, cobbles, and boulders. Abundant supplies of

  8. Early Holocene fauna from a new subfossil site: A first assessment from Christmas River, south central Madagascar

    Directory of Open Access Journals (Sweden)

    Patricia C. Wright

    2012-06-01

    Full Text Available We report on faunal remains recovered during recent explo­rations at ‘Christmas River’, the only subfossil locality known from Madagascar’s south central plateau. Recovered remains of several extinct taxa date to approximately 10,000 14C years before present (BP, including crocodiles, tortoises, the elephant bird Aepyornis, the carnivoran Cryptoprocta spelea, the lemurs Archaeolemur majori, Pachylemur insignis, and Megaladapis edwardsi, and abundant remains of the dwarf hippopotamus, Hippopotamus lemerlei. The presence of southern – limited, forest – dependent species at Christmas River supports the hypothesis that forest once extended, perhaps discontinu­ously, across the central highlands towards the west. One theory is that sites in the north central highlands, which are higher in elevation, maintained more mesic conditions during Plio–Quaternary climate shifts than those of the lower elevation sites of the south central highlands. Thus, elevation above sea level may have acted as a filter that limited species dispersal across the island in the past. Such a scenario would explain the distinction between more humid, higher elevation, northern highland subfossil communities versus more arid, lower eleva­tion, southern subfossil communities. Continued exploration at Christmas River thus provides a remarkable opportunity for deciphering ecological changes that have taken place in south central Madagascar during the Holocene. RÉSUMÉMadagascar est reconnue comme l’une des régions les plus sensibles du monde en ce qui concerne les menaces pesant sur sa biodiversité, et cela à cause de niveaux d’endémisme inégalés, d’une diversité variée et d’un impact humain important sur l’environnement. Suite à la colonisation par l’Homme il y a plus de 2000 ans, des extinctions de masse de la faune et un important recul forestier ont eu lieu en laissant des marques sur les écosystèmes modernes qui sont dans un état de

  9. High resolution seismic survey, Pen Branch Fault, Savannah River Site, South Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Berkman, E. (Emerald Exploration Consultants, Inc., Austin, TX (United States))

    1991-04-01

    An investigation of the Pen Branch Fault at the Savannah River Site by a series of short, high resolution seismic reflection lines was conducted. The purpose was to acquire, process, and interpret 19.9 miles of data, optimized for the upper 300 ft of geologic strata, in sufficient density such that processing performed in the conventional stepwise approach, followed by detailed interpretation, would define small scale spatial variability and structural features in the vicinity of the fault leading to definition of the location of the fault, the shallowest extent of the fault, and the quantification of the sense and magnitude of motion. The depth of optimization for the last two lines was modified to the 300 ft of geologic strata immediately above basement. Three older seismic surveys, other geophysical data, and associated borehole and geologic data were reviewed. The equipment and the acquisition, processing, and interpretation procedures are discussed in the report. The report includes a detailed line by line description and discussion of the interpretation. Figures include reference maps, contour displays of the stacking and interval velocities, diagrammatic references sketches of the interpreted layering and sedimentary features, index sketches, and specific color prints made on the workstation during the course of the interpretation. A volume of manuals on seismic devices and related equipment is included.

  10. High resolution seismic survey, Pen Branch Fault, Savannah River Site, South Carolina. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Berkman, E. [Emerald Exploration Consultants, Inc., Austin, TX (United States)

    1991-04-01

    An investigation of the Pen Branch Fault at the Savannah River Site by a series of short, high resolution seismic reflection lines was conducted. The purpose was to acquire, process, and interpret 19.9 miles of data, optimized for the upper 300 ft of geologic strata, in sufficient density such that processing performed in the conventional stepwise approach, followed by detailed interpretation, would define small scale spatial variability and structural features in the vicinity of the fault leading to definition of the location of the fault, the shallowest extent of the fault, and the quantification of the sense and magnitude of motion. The depth of optimization for the last two lines was modified to the 300 ft of geologic strata immediately above basement. Three older seismic surveys, other geophysical data, and associated borehole and geologic data were reviewed. The equipment and the acquisition, processing, and interpretation procedures are discussed in the report. The report includes a detailed line by line description and discussion of the interpretation. Figures include reference maps, contour displays of the stacking and interval velocities, diagrammatic references sketches of the interpreted layering and sedimentary features, index sketches, and specific color prints made on the workstation during the course of the interpretation. A volume of manuals on seismic devices and related equipment is included.

  11. Minimizing Characterization - Derived Waste at the Department of Energy Savannah River Site, Aiken, South Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Van Pelt, R. S.; Amidon, M. B.; Reboul, S. H.

    2002-02-25

    Environmental restoration activities at the Department of Energy Savannah River Site (SRS) utilize innovative site characterization approaches and technologies that minimize waste generation. Characterization is typically conducted in phases, first by collecting large quantities of inexpensive data, followed by targeted minimally invasive drilling to collect depth-discrete soil/groundwater data, and concluded with the installation of permanent multi-level groundwater monitoring wells. Waste-reducing characterization methods utilize non-traditional drilling practices (sonic drilling), minimally intrusive (geoprobe, cone penetrometer) and non-intrusive (3-D seismic, ground penetration radar, aerial monitoring) investigative tools. Various types of sensor probes (moisture sensors, gamma spectroscopy, Raman spectroscopy, laser induced and X-ray fluorescence) and hydrophobic membranes (FLUTe) are used in conjunction with depth-discrete sampling techniques to obtain high-resolution 3-D plume profiles. Groundwater monitoring (short/long-term) approaches utilize multi-level sampling technologies (Strata-Sampler, Cone-Sipper, Solinst Waterloo, Westbay) and low-cost diffusion samplers for seepline/surface water sampling. Upon collection of soil and groundwater data, information is portrayed in a Geographic Information Systems (GIS) format for interpretation and planning purposes. At the SRS, the use of non-traditional drilling methods and minimally/non intrusive investigation approaches along with in-situ sampling methods has minimized waste generation and improved the effectiveness and efficiency of characterization activities.

  12. Hair mercury levels and food consumption in residents from the Pearl River Delta: South China.

    Science.gov (United States)

    Shao, Dingding; Kang, Yuan; Cheng, Zhang; Wang, Hongsheng; Huang, Minjuan; Wu, Shengchun; Chen, Kunci; Wong, Ming H

    2013-01-15

    The Pearl River Delta (PRD) is located in the Southern part of China and is the main region for fish culture in Guangdong Province. In order to assess the potential health risks associated with dietary consumption of mercury, hair samples from 91 urban, town and fishing village residents, 37 species of fish, cereal, vegetables, and meat samples were collected. The average total mercury (THg) and methylmercury (MeHg) concentrations in hair were 1.08 ± 0.94 and 0.58 ± 0.59 μg/g, respectively. Daily Hg intake via fish consumption is significantly correlated with THg and MeHg accumulated in human hair (r=0.48, p<0.01; r=0.43, p<0.01). The estimated daily intake of Hg via different food types showed that both fish and cereal consumption were the two main routes of Hg exposure for residents in the sampling areas. Besides food intake, smoking was also an important source for daily THg intake in the smoke group, contributing 11-18% to EDI of THg.

  13. Human exposure to mercury in San Jorge river basin, Colombia (South America).

    Science.gov (United States)

    Olivero, Jesus; Johnson, Boris; Arguello, Eduardo

    2002-04-22

    During May-September 1999 human hair samples were collected from the village of Caimito, a fishing community of the state of Sucre (Colombia), in the San Jorge River basin area, and analyzed for total mercury (t-Hg) by cold vapor atomic absorption spectroscopy. T-Hg was measured in both male and female people aged 15-65 years, whose diet mainly consists of fish collected in nearby marshes. Average hair t-Hg concentration in people from Caimito was 4.91 +/- 0.55 microg/g (n = 94), similar to the value previously detected in fishermen living in the gold mining area, 50 km east. Males had similar t-Hg concentrations (4.31 +/- 0.42 microg/g; n = 56) to females (5.78 +/- 1.21 microg/g; n = 38) and there was no difference in t-Hg levels between groups of different age. Mercury content in hair was weakly but significantly associated (R = 0.20, P = 0.05) with fish consumption.

  14. Analysis of Sediment Transport for Rivers in South Korea based on Data Mining technique

    Science.gov (United States)

    Jang, Eun-kyung; Ji, Un; Yeo, Woonkwang

    2017-04-01

    The purpose of this study is to calculate of sediment discharge assessment using data mining in South Korea. The Model Tree was selected for this study which is the most suitable technique to explicitly analyze the relationship between input and output variables in various and diverse databases among the Data Mining. In order to derive the sediment discharge equation using the Model Tree of Data Mining used the dimensionless variables used in Engelund and Hansen, Ackers and White, Brownlie and van Rijn equations as the analytical condition. In addition, total of 14 analytical conditions were set considering the conditions dimensional variables and the combination conditions of the dimensionless variables and the dimensional variables according to the relationship between the flow and the sediment transport. For each case, the analysis results were analyzed by mean of discrepancy ratio, root mean square error, mean absolute percent error, correlation coefficient. The results showed that the best fit was obtained by using five dimensional variables such as velocity, depth, slope, width and Median Diameter. And closest approximation to the best goodness-of-fit was estimated from the depth, slope, width, main grain size of bed material and dimensionless tractive force and except for the slope in the single variable. In addition, the three types of Model Tree that are most appropriate are compared with the Ackers and White equation which is the best fit among the existing equations, the mean discrepancy ration and the correlation coefficient of the Model Tree are improved compared to the Ackers and White equation.

  15. Environmental isotopic and hydrochemical characteristics of groundwater from the Sandspruit Catchment, Berg River Basin, South Africa.

    Science.gov (United States)

    Naicker, S; Demlie, M

    2014-01-01

    The Sandspruit catchment (a tributary of the Berg River) represents a drainage system, whereby saline groundwater with total dissolved solids (TDS) up to 10,870 mg/l, and electrical conductivity (EC) up to 2,140 mS/m has been documented. The catchment belongs to the winter rainfall region with precipitation seldom exceeding 400 mm/yr, as such, groundwater recharge occurs predominantly from May to August. Recharge estimation using the catchment water-balance method, chloride mass balance method, and qualified guesses produced recharge rates between 8 and 70 mm/yr. To understand the origin, occurrence and dynamics of the saline groundwater, a coupled analysis of major ion hydrochemistry and environmental isotopes (δ(18)O, δ(2)H and (3)H) data supported by conventional hydrogeological information has been undertaken. These spatial and multi-temporal hydrochemical and environmental isotope data provided insight into the origin, mechanisms and spatial evolution of the groundwater salinity. These data also illustrate that the saline groundwater within the catchment can be attributed to the combined effects of evaporation, salt dissolution, and groundwater mixing. The salinity of the groundwater tends to vary seasonally and evolves in the direction of groundwater flow. The stable isotope signatures further indicate two possible mechanisms of recharge; namely, (1) a slow diffuse type modern recharge through a relatively low permeability material as explained by heavy isotope signal and (2) a relatively quick recharge prior to evaporation from a distant high altitude source as explained by the relatively depleted isotopic signal and sub-modern to old tritium values.

  16. Residues of fluoroquinolones in marine aquaculture environment of the Pearl River Delta, South China.

    Science.gov (United States)

    He, Xiuting; Wang, Zhaohui; Nie, Xiangping; Yang, Yufen; Pan, Debo; Leung, Anna O W; Cheng, Zhang; Yang, Yongtao; Li, Kaibin; Chen, Kunci

    2012-06-01

    Concentrations and distributions of selected fluoroquinolones (norfloxacin, ciprofloxacin and enrofloxacin) in water, sediments and nine kinds of fish species collected from 6 sites in two marine aquaculture regions of the Pearl River Delta, China, were analyzed by using high-performance liquid chromatography with fluorescence detector (HPLC). The results showed that the concentrations of ciprofloxacin and enrofloxacin were below the limits of quantification (LOQ) in all water samples except for norfloxacin. Norfloxacin and ciprofloxacin concentrations ranged from 1.88 to 11.20 ng g(-1) dry wt, 0.76-2.42 ng g(-1) dry wt in sediments collected from the Dapeng'ao region (sites 1-3) and ranged from 2.31 to 4.75 ng g(-1) dry wt, 1.26-1.76 ng g(-1) dry wt in sediments collected from the Hailing Island region (sites 4-6), respectively. However, no enrofloxacin was found in all sediment samples. The three fluoroquinolones (FQs) were detected in all fish samples, and the concentrations were higher in liver tissues than those in muscle tissues. The levels of norfloxacin were higher than ciprofloxacin and enrofloxacin in both liver and muscle tissues. Among the nine marine fish species, Siganus fuscescens from Hailing Island had a significantly high level of norfloxacin in liver tissue (254.58 ng g(-1) wet wt), followed by Sparus macrocephalus (133.15 ng g(-1) wet wt) from Dapeng'ao, and the lowest value was Lutianus argentimaculatus (5.18 ng g(-1) wet wt) from Hailing Island. The obtained results of FQs in present study do not represent a risk to the human health in Guangdong coastal area, based on the maximum residue limits (MRLs) established by Chinese Government and the acceptable daily intake (ADI) recommended by the Food and Agriculture Organization and World Health Organization (FAO/WHO).

  17. Mercury speciation and emission from municipal solid waste incinerators in the Pearl River Delta, South China.

    Science.gov (United States)

    Chen, Laiguo; Liu, Ming; Fan, Ruifang; Ma, Shexia; Xu, Zhencheng; Ren, Mingzhong; He, Qiusheng

    2013-03-01

    The potential for Hg release during municipal solid waste incineration (MSWI) is attracting increased attention due to high volume of municipal waste being treated by incineration in China. Emission amounts have been estimated using emission factors developed for other countries. To fine tune our emission estimate total mercury (THg) and mercury speciation were measured using isokinetic sampling in eight plants, of which six used grate furnace combustor (GFC) and two circulation fluidized bed combustors (CFBCs). Results showed that average THg concentration (19.5 ± 13.6 μg/Nm) in flue gas at the facilities that used CFBC was significantly lower than that at those using GFC (51.4 ± 28.3 μg/Nm, p=0.002). Gaseous oxidized mercury (GOM), gaseous elemental mercury (GEM, Hg), and particulate mercury (Hg) represented 95.5 ± 3.8%, 4.1 ± 3.9% and 0.4 ± 0.3% in GFC, and 63.8 ± 8.6%, 33.6 ± 10.5% and 2.6 ± 1.9% in CFBC, respectively. The measured average THg emission factor for the 8 MSWI plants was 208 ± 130 mg/t in the Pearl River Delta (PRD) region, with 217 ± 158 mg/t and 188 ± 17.7 mg/t were from GFC and CFBC, respectively. Using the average emission factor the estimated total mercury emissions from MSWI were 4.67 ± 2.91 t in China, and 770 ± 65.5 kg in the PRD region in 2010. Of these, 4240 ± 210 kg, 408 ± 231 kg and 14.8 ± 14.1 kg, and 688 ± 37 kg, 78.9 ± 40.6 kg and 3.2 ± 3.0 kg were GOM, Hg, and Hg, respectively. Mercury emissions will continue to increase as the amounts of MSW being incinerated increases.

  18. Migration of the Pee Dee River system inferred from ancestral paleochannels underlying the South Carolina Grand Strand and Long Bay inner shelf

    Science.gov (United States)

    Baldwin, W.E.; Morton, R.A.; Putney, T.R.; Katuna, M.P.; Harris, M.S.; Gayes, P.T.; Driscoll, N.W.; Denny, J.F.; Schwab, W.C.

    2006-01-01

    Several generations of the ancestral Pee Dee River system have been mapped beneath the South Carolina Grand Strand coastline and adjacent Long Bay inner shelf. Deep boreholes onshore and high-resolution seismic-reflection data offshore allow for reconstruction of these paleochannels, which formed during glacial lowstands, when the Pee Dee River system incised subaerially exposed coastal-plain and continental-shelf strata. Paleochannel groups, representing different generations of the system, decrease in age to the southwest, where the modern Pee Dee River merges with several coastal-plain tributaries at Winyah Bay, the southern terminus of Long Bay. Positions of the successive generational groups record a regional, southwestward migration of the river system that may have initiated during the late Pliocene. The migration was primarily driven by barrier-island deposition, resulting from the interaction of fluvial and shoreline processes during eustatic highstands. Structurally driven, subsurface paleotopography associated with the Mid-Carolina Platform High has also indirectly assisted in forcing this migration. These results provide a better understanding of the evolution of the region and help explain the lack of mobile sediment on the Long Bay inner shelf. Migration of the river system caused a profound change in sediment supply during the late Pleistocene. The abundant fluvial source that once fed sand-rich barrier islands was cut off and replaced with a limited source, supplied by erosion and reworking of former coastal deposits exposed at the shore and on the inner shelf.

  19. The control of Simuliidae (Diptera, Nematocera) in South African rivers by modification of the water flow volume.

    Science.gov (United States)

    Howell, C J; Begemann, G J; Muir, R W; Louw, P

    1981-03-01

    It was found that the build-up of simuliid numbers subsequent to the construction of dams in the Vaal and Orange Rivers could be successfully prevented by periodic, artificially controlled reductions in the water-levels in these rivers.

  20. Effects of mining activities on heavy metal concentrations in water, sediment, and macroinvertebrates in different reaches of the Pilcomayo River, South America.

    Science.gov (United States)

    Smolders, A J P; Lock, R A C; Van der Velde, G; Medina Hoyos, R I; Roelofs, J G M

    2003-04-01

    From 1997 until 1999 the extent and the ecological effects of zinc, copper, lead, and cadmium pollution were studied in different reaches of the South American Pilcomayo River. A comparison of metal concentrations in water, sediment, and chironomid larvae, as well as the diversity of macroinvertebrate species, was made between sites near the origin of the Pilcomayo River, with hardly any mining activities, sites in the Potosí region, with intensive mining, and sites located 500 km or further downstream of Potosí, in the Chaco plain. Samples were also collected in an unpolluted river (Cachi Mayu River) and in the Tarapaya River, which is strongly contaminated by mine tailings (1000 tons a day). The upper parts of the Pilcomayo River are strongly affected by the release of mine tailings from the Potosí mines where mean concentrations of lead, cadmium, copper, and zinc in water, filtered water, sediment, and chironomid larvae were up to a thousand times higher than the local background levels. The diversity of the benthic macroinvertebrate community was strongly reduced in the contaminated parts; 97% of the benthic macroinvertebrates consisted of chironomid larvae. The degree of contamination in the lower reaches of the river, however, was fairly low because of sedimentation processes and the strong dilution of mine tailings with enormous amounts of clean sediment from erosion processes. Analysis of sediment cores from the Ibibobo floodplain, however, reveal an increase of the heavy metal concentrations in the lower reaches since the introduction of the contaminating flotation process in the mine industry in 1985.

  1. Late Holocene development of a major fluvial discontinuity in floodplain wetlands of the Blood River, eastern South Africa

    Science.gov (United States)

    Tooth, Stephen; McCarthy, Terence; Rodnight, Helena; Keen-Zebert, Amanda; Rowberry, Matthew; Brandt, Dion

    2014-01-01

    In dryland settings, most floodplain wetlands form in low gradient, low energy environments that are characterised by strong interactions between flow, sediment and biota. Some floodplain wetlands are only partly channelled or largely unchannelled, and represent major discontinuities in drainage networks, fundamentally influencing downvalley water and sediment transfer. In the > 15 km2 Blood River floodplain wetlands, located in subhumid to semiarid eastern South Africa, field investigations, aerial photographs, and optically stimulated luminescence (OSL) ages provide evidence for development of a major discontinuity during the very late Holocene. Between ~ 800 and 100 years ago, the wetlands were characterised by a through-going, meandering channel set within a floodplain up to 2.5 km wide. A sinuous channel remains in the lower part of the wetlands but during the last ~ 100 years major morphological and sedimentary changes have occurred upvalley. The former through-going, meandering channel has been replaced by a straighter channel that decreases in size downstream and terminates in a 'floodout', characterised here by an unchannelled reedbed. Small tributaries supply water and limited sediment to this floodout and another floodout located farther downvalley. Organo-clastic sediments > 3 m thick have accumulated in the floodouts as broad lobes, in places burying the former meander-belt sediments. On the steepened, downvalley sides of these lobes, small headcutting channels convey water that filters through the reedbeds. If headcutting through the lobes continues, a through-going channel may re-establish upvalley, possibly eventually linking with the sinuous but now moribund channel in the lower part of the wetlands. Along the Blood River, the initial cause(s) of the sequence of changes is not known, but these channel-floodplain adjustments are partially analogous to the system-scale, autogenic morphological and sedimentary dynamics of those dryland fluvial systems

  2. Low-flow frequency and flow duration of selected South Carolina streams in the Catawba-Wateree and Santee River Basins through March 2012

    Science.gov (United States)

    Feaster, Toby D.; Guimaraes, Wladmir B.

    2014-01-01

    Part of the mission of both the South Carolina Department of Health and Environmental Control and the South Carolina Department of Natural Resources is to protect and preserve South Carolina’s water resources. Doing so requires an ongoing understanding of streamflow characteristics of the rivers and streams in South Carolina. A particular need is information concerning the low-flow characteristics of streams, which is especially important for effectively managing the State’s water resources during critical flow periods, such as during the historic droughts that South Carolina has experienced in the past few decades. In 2008, the U.S. Geological Survey, in cooperation with the South Carolina Department of Health and Environmental Control, initiated a study to update low-flow statistics at continuous-record streamgaging stations operated by the U.S. Geological Survey in South Carolina. This report presents the low-flow statistics for 11 selected streamgaging stations in the Catawba-Wateree and Santee River Basins in South Carolina and 2 in North Carolina. For five of the streamgaging stations, low-flow statistics include daily mean flow durations or the 5-, 10-, 25-, 50-, 75-, 90-, and 95-percent probability of exceedance and the annual minimum 1-, 3-, 7-, 14-, 30-, 60-, and 90-day mean flows with recurrence intervals of 2, 5, 10, 20, 30, and 50 years, depending on the length of record available at the streamgaging station. For the other eight streamgaging stations, only daily mean flow durations and (or) exceedance percentiles of annual minimum 7-day average flows are provided due to regulation. In either case, the low-flow statistics were computed from records available through March 31, 2012. Of the five streamgaging stations for which recurrence interval computations were made, three streamgaging stations in South Carolina were compared to low-flow statistics that were published in previous U.S. Geological Survey reports. A comparison of the low

  3. Chapter A. Effects of urbanization on stream ecosystems in the South Platte River basin, Colorado and Wyoming

    Science.gov (United States)

    Sprague, Lori A.; Zuellig, Robert E.; Dupree, Jean A.

    2006-01-01

    This report describes the effects of urbanization on physical, chemical, and biological characteristics of stream ecosystems in 28 basins along an urban land-use gradient in the South Platte River Basin, Colorado and Wyoming, from 2002 through 2003. Study basins were chosen to minimize natural variability among basins due to factors such as geology, elevation, and climate and to maximize coverage of different stages of urban development among basins. Because land use or population density alone often are not a complete measure of urbanization, land use, land cover, infrastructure, and socioeconomic variables were integrated in a multimetric urban intensity index to represent the degree of urban development in each study basin. Physical characteristics studied included stream hydrology, stream temperature, and habitat; chemical characteristics studied included nutrients, pesticides, suspended sediment, sulfate, chloride, and fecal bacteria concentrations; and biological characteristics studied included algae, fish, and invertebrate communities. Semipermeable membrane devices (SPMDs), passive samplers that concentrate trace levels of hydrophobic organic contaminants like polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), also were used. The objectives of the study were to (1) examine physical, chemical, and biological responses along the gradient of urbanization; (2) determine the major physical, chemical, and landscape variables affecting the structure of aquatic communities; and (3) evaluate the relevance of the results to the management of water resources in the South Platte River Basin. Commonly observed effects of urbanization on instream physical, chemical, and biological characteristics, such as increased flashiness, higher magnitude and more frequent peak flows, increased concentrations of chemicals, and changes in aquatic community structure, generally were not observed in this study. None of the hydrologic, temperature, habitat

  4. Isotopic evidences of groundwater circulation in the Kaidu River, South Tianshan Mountains, Central Asia

    Science.gov (United States)

    FAN, Yuting; Métivier, François; Chen, Yaning; He, Qing; Wang, Yun

    2015-04-01

    Water demand always exceeds supply in many parts of the world, especially in the arid and semi-arid regions. Groundwater is the primary input to hydrological systems like surface water bodies in polar and high mountain regions. A reasonable application of water isotopes requires a good understanding of the isotopic fractionation in processes controlling the isotopic composition of surface water and groundwater. Through the review of published papers, we find there is still scope for improving the understanding of groundwater isotopes: (1) quite few studies on groundwater circulation via kinetic fractionation of stable isotopes in the arid region of Central Asia; (2) several shortcomings on the quantitative assessment of water recycling for mountain-plain area. Tianshan Mountains, located in Xinjiang Province, is always called water tower in Central Asia and play an important role in the water cycle. In this paper, we implemented hydro-chemical index and Stable isotope mass balance method to study transformation of groundwater with surface water and to quantify recharge proportion between water bodies of typical regions. As a first step towards quantifying the contribution of groundwater, three-component mixing model of Kaidu River Basin into its constituent components has been done. Chemistry type of headstreams in this basin is mainly Ca-Mg-HCO3, while major ions and salinity of surface water show an increasing trend with the water rising time, which could be attributable to significant features of surface water evaporation and concentration. After that chemistry type of oasis-plain area in the basin is mainly Ca-HCO3-CO4. Groundwater recharge ratio was processed via spatial scale, it is only about 15% in upstream areas, while it accounted for 45% or more in the middle and lower reaches. Two groundwater recharge districts were divided according to the distribution characteristics of surface water. The first recharge district is from mountain area with spring

  5. Distribution and bioconcentration of endocrine disrupting chemicals in surface water and fish bile of the Pearl River Delta, South China.

    Science.gov (United States)

    Yang, Juan; Li, Haiyan; Ran, Yong; Chan, Kingming

    2014-07-01

    The distribution and bioconcentration of endocrine disrupting chemicals (EDCs) in water, algae, and wild carp bile of the Pearl River Delta (PRD), South China were investigated. 4-tert octylphenol (OP), 4-nonylphenol (NP), and bisphenol A (BPA) (unit, ng L(-1)) in water were in the ranges of 1-14, 117-865, and 4-377, those (ng g(-1) dry weight) in algae were in the ranges of 2-13, 53-282, and 16-94, and those (ng g(-1)) in carp bile were in the ranges of 14-39, 950-4648, 70-1020, respectively. Estrone (E1) and 17α-ethinylestradiol (EE2) in water ranged from

  6. Dry spells assessment with reference to the maize crop in the Luvuvhu River catchment of South Africa

    Science.gov (United States)

    Masupha, Teboho Elisa; Moeletsi, Mokhele Edmond; Tsubo, Mitsuru

    2016-04-01

    Agricultural productivity in South Africa is negatively affected by drought as a result of frequent periodic dry spells and increasing crop water demands resulting in poor crop development and low yields. Thus, we embarked on this study which aims at investigating dry spell occurrences in relation to growing season of maize in the Luvuvhu River Catchment. Daily rainfall data (1945-2014) from 12 stations which represent the catchment fairly well was utilized in this study. Three consecutive planting dates were staggered based on three consecutive onsets of the rainy season. Dry spells were categorized into three groups: short, medium and long dry spells. The data was then subjected to theoretical distribution fitting using the Anderson-Darling goodness-of-fit test; and probabilities of occurrence were computed using a probabilistic model that best fits the data. Trend analysis was performed on the frequency of dry spells per growing period using the non-parametric Spearman's rank correlation test. Out results indicated high probabilities (≥80%) of short dry spells at all the stations irrespective of the timing of planting. Further analysis revealed that a risk of yield reduction with planting following the first onset of rains was higher than that with planting following the second and third onsets. In order to minimize this risk, farmers can be advised to plant between mid-November to mid-December. Trend analysis indicated no trend for all the various dry spell lengths except for Thohoyandou with a decreasing trend and Sigonde with a weak increasing trend in long dry spells. Such findings can be used to describe drought conditions for improvement of agricultural productivity and food security, in a given area.

  7. Unconventional natural gas development did not result in detectable changes in water chemistry (within the South Fork Little Red River).

    Science.gov (United States)

    Austin, Bradley J; Scott, Erin; Massey, Leslie; Evans-White, Michelle A; Entrekin, Sally; Haggard, Brian E

    2017-05-01

    The Fayetteville Shale within north central Arkansas is an area of extensive unconventional natural gas (UNG) production. Recently, the Scott Henderson Gulf Mountain Wildlife Management Area (GMWMA) was leased from the state of Arkansas for NG exploration, raising concerns about potential impacts on water resources. From November 2010 through November 2014, we monitored four reaches of the South Fork Little Red River (SFLRR), within the GMWMA, establishing baseline physico-chemical characteristics prior to UNG development and assessing trends in parameters during and after UNG development. Water samples were collected monthly during baseflow conditions and analyzed for conductivity, turbidity, ions, total organic carbon (TOC), and metals. All parameters were flow-adjusted and evaluated for monotonic changes over time. The concentrations of all constituents measured in the SFLRR were generally low (e.g., nitrate ranged from <0.005 to 0.268 mg/l across all sites and sample periods), suggesting the SFLRR is of high water quality. Flow-adjusted conductivity measurements and sodium concentrations increased at site 1, while magnesium decreased across all four sites, TOC decreased at sites 1 and 3, and iron decreased at site 1 over the duration of the study. With the exception of conductivity and sodium, the physico-chemical parameters either decreased or did not change over the 4-year duration, indicating that UNG activities within the GMWMA have had minimal or no detectable impact on water quality within the SFLRR. Our study provides essential baseline information that can be used to evaluate water quality within the SFLRR in the future should UNG activity within the GMWMA expand.

  8. Exposed tree root analysis as a dendrogeomorphic approach to estimating bank retreat at the South River, Virginia

    Science.gov (United States)

    Stotts, Stephanie; O'Neal, Michael; Pizzuto, James; Hupp, Cliff

    2014-10-01

    We use a biometric approach based on anatomical changes in the wood of exposed tree roots to quantify riverbank erosion along South River, Virginia, a site where commonly applied techniques for determining bank erosion rates are either not appropriate because of the required spatial scale of analysis (i.e., erosion pins, traditional surveys, LiDAR analysis) or have failed to detect obvious erosion (i.e., photogrammetric techniques). We sampled 73 exposed roots from 22 study reaches and identified the year of exposure macroscopically (2 to 20 times magnification) and microscopically (20 to 100 times magnification), comparing the estimated erosion rates between levels of magnification and to those obtained with photogrammetric techniques. We found no statistical differences between the results of macroscopic and microscopic analyses (t-test, α = 0.01) but encountered difficulty in identifying the year of root exhumation in some samples. When comparing exposed root analysis to photogrammetric techniques, the results indicate that the exposed root approach is a feasible and effective method for estimating annual- to decadal-scale bank erosion. In addition to producing erosion rates statistically indistinguishable from photogrammetric techniques at sites with erosion rates large enough for detection using historical aerial photographs (regression analysis and t-test, α = 0.01), exposed root analysis was able to estimate erosion rates at sites where photogrammetric techniques failed. We also identify deciduous species well suited for this approach (Fraxinus pennsylvanica) and others that prove more problematic (e.g., Acer negundo, Celtis occidentalis, Acer saccharinum). This study is significant because it describes a robust tool that provides insights into annual- to decadal-scale erosion where other commonly applied techniques may not be appropriate or easily applied.

  9. Stable isotope hydrology in fractured and detritic aquifers at both sides of the South Atlantic Ocean: Mar del Plata (Argentina) and the Rawsonville and Sandspruit river catchment areas (South Africa)

    Science.gov (United States)

    Glok Galli, Melisa; Damons, Matthew E.; Siwawa, Sitembiso; Bocanegra, Emilia M.; Nel, Jacobus M.; Mazvimavi, Dominic; Martínez, Daniel E.

    2017-01-01

    The aim of this work is to characterize the isotope composition of water (2H and 18O) in order to establish the relationship between fractured and detritic aquifers in similar hydrological environments located at both sides of the Atlantic Ocean. The Mar del Plata zone, placed in the Argentine Buenos Aires province in South America, and the Rawsonville and Sandspruit river catchment areas, situated in the Western Cape province in South Africa were compared. Rainwater and groundwater samples from fractured and detritic aquifers were analyzed through laser spectroscopy. In both Argentina and South African study sites, stable isotopes data demonstrate an aquifers recharge source from rainfall. For the Mar del Plata region, two different groups of detritic aquifer's samples with distinct recharge processes can be identified due to the close relationship existing between the present hydrogeological environments, the aquifer's grain size sediments and the isotopes contents: one representing rapid infiltration in aquifer sediments of the creeks' palaeobeds and hills zones (sandy or silt sandy sediments) and the other with slow infiltration of evaporated water in plain zones with an aquitard behavior. In the last group, the evaporation process occurs previous infiltration or in the aquifer's non-saturated zone, because of the existence of very low topographic gradients and fine-grained sediments. The evaporation phenomenon is not evident in the Sandspruit river catchment site's detritic aquifer, because its sandy composition allows a faster infiltration rate than in the loess that compounds the Pampeano aquifer in the interfluves zones of the Argentinian study area.

  10. Sediment Quality and Comparison to Historical Water Quality, Little Arkansas River Basin, South-Central Kansas, 2007

    Science.gov (United States)

    Juracek, Kyle E.; Rasmussen, Patrick P.

    2008-01-01

    The spatial and temporal variability in streambed-sediment quality and its relation to historical water quality was assessed to provide guidance for the development of total maximum daily loads and the implementation of best-management practices in the Little Arkansas River Basin, south-central Kansas. Streambed-sediment samples were collected at 26 sites in 2007, sieved to isolate the less than 63-micron fraction (that is, the silt and clay), and analyzed for selected nutrients (total nitrogen and total phosphorus), organic and total carbon, 25 trace elements, and the radionuclides beryllium-7, cesium-137, lead-210, and radium-226. At eight sites, streambed-sediment samples also were collected and analyzed for bacteria. Particulate nitrogen, phosphorus, and organic carbon concentrations in the streambed sediment varied substantially spatially and temporally, and positive correlations among the three constituents were statistically significant. Along the main-stem Little Arkansas River, streambed-sediment concentrations of particulate nitrogen and phosphorus generally were larger at and downstream from Alta Mills, Kansas. The largest particulate nitrogen concentrations were measured in samples collected in the Emma Creek subbasin and may be related to livestock and poultry production. The largest particulate phosphorus concentrations in the basin were measured in samples collected along the main-stem Little Arkansas River downstream from Alta Mills, Kansas. Particulate nitrogen, phosphorus, and organic carbon content in the water and streambed-sediment samples typically decreased as streamflow increased. This inverse relation may be caused by an increased contribution of sediment from channel-bank sources during high flows and (or) increased particle sizes transported by the high flows. Trace element concentrations in the streambed sediment varied from site to site and typically were less than threshold-effects guidelines for possible adverse biological effects

  11. Fate of linear alkylbenzenes and benzothiazoles of anthropogenic origin and their potential as environmental molecular markers in the Pearl River Delta, South China

    Energy Technology Data Exchange (ETDEWEB)

    Ni Honggang [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Graduate School, Chinese Academy of Sciences, Beijing 100049 (China); Shen Rulang [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Zeng Hui [Key Laboratory for Environmental and Urban Sciences, Shenzhen Graduate School, Peking University, Shenzhen 518055 (China); Zeng, Eddy Y., E-mail: eddyzeng@gig.ac.c [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China)

    2009-12-15

    The mass emissions of linear alkylbenzenes (LABs), benzothiazole (BT), and 2-[4-morpholinyl]benzothiazole (24MoBT) from anthropogenic activities within one year were estimated according to the population and the number of automobiles in the Pearl River Delta (PRD), South China. Based on the estimation, the distribution of these compounds among various environmental media was simulated with a mass balance box model established in the present study. The results showed that 79% of LABs generated in the PRD was stored in sediment while only 1.3% of LABs was presumably transported to the adjacent South China Sea (SCS). On the contrary, 47% of BT and 77% of 24MoBT generated in the region were carried with riverine runoff to the coastal ocean. The results from the present study suggest that hydrophobic compounds tend to stay in the watershed of the PRD, whereas hydrophilic ones mainly outflow to the coastal ocean. - A simple mass balance box model examines the fate of linear alkylbenzenes and benzothiazoles in the Pearl River Delta, South China.

  12. Low-flow frequency and flow duration of selected South Carolina streams in the Saluda, Congaree, and Edisto River basins through March 2009

    Science.gov (United States)

    Feaster, Toby D.; Guimaraes, Wladmir B.

    2012-01-01

    Part of the mission of the South Carolina Department of Health and Environmental Control and the South Carolina Department of Natural Resources is to protect and preserve South Carolina's water resources. Doing so requires an ongoing understanding of streamflow characteristics of the rivers and streams in South Carolina. A particular need is information concerning the low-flow characteristics of streams, which is especially important for effectively managing the State's water resources during critical flow periods, such as during periods of severe drought like South Carolina has experienced in the last decade or so. The U.S. Geological Survey, in cooperation with the South Carolina Department of Health and Environmental Control, initiated a study in 2008 to update low-flow statistics at continuous-record streamgaging stations operated by the U.S. Geological Survey in South Carolina. This report presents the low-flow statistics for 25 selected streamgaging stations in the Saluda, Congaree, and Edisto River basins in South Carolina, and includes flow durations for the 5-, 10-, 25-, 50-,75-, 90-, and 95-percent exceedances and the annual minimum 1-, 3-, 7-, 14-, 30-, 60-, and 90-day average flows with recurrence intervals of 2, 5, 10, 20, 30, and 50 years, depending on the length of record available at the streamgaging station. The low-flow statistics were computed from records available through March 31, 2009. Of the 25 streamgaging stations for which recurrence interval computations were made, 20 were compared to low-flow statistics that were published in previous U.S. Geological Survey reports. A comparison of the low-flow statistics for the annual minimum 7-day average streamflow with a 10-year recurrence interval (7Q10) from this study with the most recently published values indicates that 18 of the 20 streamgaging stations have values lower than the previous published values. The low-flow statistics are influenced by length of record, hydrologic regime under

  13. 江南某城镇河道水体污染现状分析及修复%SOUTH OF YANGZI RIVER SOME CITIES RIVER COURSE WATER BODY POLLUTION PRESENT SITUATION ANALYSIS AND REPAIR

    Institute of Scientific and Technical Information of China (English)

    张同祺; 李勇; 李大鹏; 刘玉杰

    2011-01-01

    Through monitors many times, analyzing the south of Yangzi River some river course black odor pollution reasons, and through the artificial aeration, throwing adds the microorganism microbial inoculum, the sediments control, the planter aquatic plant to carry on the advanced treatment to this river course, the project can remove pollutant effectively and so on water body organic matter, ammonia nitrogen, phosphorus, plays the emergency repair stream pollution, the persistent effect maintains the rivers water quality, achieves the anticipated target.%通过多次监测,分析了引起江南某河道污染黑臭的原因,通过采取人工曝气、投加微生物菌剂、底泥控制、种植水生植物等措施对该河道进行深度处理.实际运行结果表明,工程能够有效去除水体中的有机物、氨氮、磷等污染物,起到应急修复河流污染、长效保持河流水质的作用,达到预期目标.

  14. Aerial photo mosaic of the Gravelford Reach, North Fork Coquille River and Myrtle Point Reach, South Fork Coquille River, Oregon in 1939

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Coquille River system is an unregulated system that encompasses 2,745 square kilometers of southwestern Oregon and flows into the Pacific Ocean near the town of...

  15. Maintenance Dredging of Charleston Harbor, Ashley River, and U.S. Navy Channels in Cooper River Charleston and Berkeley Counties, South Carolina.

    Science.gov (United States)

    1976-03-01

    commonly found in and around the marsh at various times of the year are blue crabs, hermit crabs, brown and white shrimp , mantis shrimp , grass shrimp ...increasing as a result of improved water quality. The Ashley River also serves as a nursery for blue crabs, brown and white shrimp , and various marine...few shrimp . 2.12.3.4.1 The river is classified in the SB category which purmits bathing, fishing, crabbing and other uses but prohibits the taking f

  16. Determination of selected antibiotics in the Victoria Harbour and the Pearl River, South China using high-performance liquid chromatography-electrospray ionization tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Xu Weihai [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, Guangzhou 510640 (China); School of Chemistry and Chemical Engineering, Zhongshan University, Guangzhou 510250 (China); Department of Civil and Structural Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong (China); Post-graduate School of the Chinese Academy of Sciences, Beijing 100039 (China); Zhang Gan [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, Guangzhou 510640 (China)]. E-mail: zhanggan@gig.ac.cn; Zou Shichun [School of Chemistry and Chemical Engineering, Zhongshan University, Guangzhou 510250 (China); Li Xiangdong [Department of Civil and Structural Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong (China); Liu Yuchun [School of Chemistry and Chemical Engineering, Zhongshan University, Guangzhou 510250 (China)

    2007-02-15

    Nine selected antibiotics in the Victoria Harbour of Hong Kong and the Pearl River at Guangzhou, South China, were analyzed using high-performance liquid chromatography-electrospray ionization tandem mass spectrometry. The results showed that the concentrations of antibiotics were mainly below the limit of quantification (LOQ) in the marine water of Victoria Harbour. However, except for amoxicillin, all of the antibiotics were detected in the Pearl River during high and low water seasons with the median concentrations ranging from 11 to 67 ng/L, and from 66 to 460 ng/L, respectively; and the concentrations in early spring were about 2-15 times higher than that in summer with clearer diurnal variations. It was suggested that the concentrations of antibiotics in the high water season were more affected by wastewater production cycles due to quick refreshing rate, while those in the low water season may be more sensitive to the water column dynamics controlled by tidal processes in the river. - Antibiotics were found at high concentrations in an urban reach of Pearl River in southern China with contrast diurnal variations between the high and low water seasons.

  17. Water quality and relation to taste-and-odor compounds in North Fork Ninnescah River and Cheney Reservoir, south-central Kansas, 1997-2003

    Science.gov (United States)

    Christensen, Victoria G.; Graham, Jennifer L.; Milligan, Chad R.; Pope, Larry M.; Ziegler, Andrew C.

    2006-01-01

    Cheney Reservoir, the primary water supply for the city of Wichita in south-central Kansas, and its main source of inflow, the North Fork Ninnescah River, were sampled between 1997 and 2003 for sediment, nutrients, and the taste-and-odor-causing compounds geosmin and 2-methylisoborneol (MIB). It is believed that objectionable tastes and odors in Cheney Reservoir result from cyanobacteria (blue-green algae), and there is concern with proliferation of algal growth. Both nutrients and suspended solids affect algal growth and may be a concern for taste-and-odor issues. The transport of nutrients and suspended solids from the North Fork Ninnescah River to Cheney Reservoir was monitored as part of an effort to understand and thereby mitigate algal proliferation. The regression-estimated concentrations of total phosphorus in water entering the reservoir from the North Fork Ninnescah River during 2001–03 exceeded the base-flow, runoff, and long-term goals established by the Cheney Reservoir Task Force. Total suspended-solids concentrations in water from the North Fork Ninnescah River during 2001–03 generally exceeded long-term goals only during periods of runoff.

  18. The effects of the Chesapeake Bay impact crater on the geologic framework and the correlation of hydrogeologic units of southeastern Virginia, south of the James River

    Science.gov (United States)

    Powars, David S.

    2000-01-01

    About 35 million years ago, a large comet or meteor slammed into the shallow shelf on the western margin of the Atlantic Ocean, creating the Chesapeake Bay impact crater. This report, the second in a series, refines the geologic framework of southeastern Virginia, south of the James River in and near the impact crater, and presents evidence for the existence of a pre-impact James River structural zone. The report includes detailed correlations of core lithologies with borehole geophysical logs; the correlations provide the foundation for the compilation of stratigraphic cross sections. These cross sections are tied into the geologic framework of the lower York-James Peninsula as presented in the first report in the series, Professional Paper 1612

  19. Heavy metals relationship with water and size-fractionated sediments in rivers using canonical correlation analysis (CCA) case study, rivers of south western Caspian Sea.

    Science.gov (United States)

    Vosoogh, Ali; Saeedi, Mohsen; Lak, Raziyeh

    2016-11-01

    Some pollutants can qualitatively affect aquatic freshwater such as rivers, and heavy metals are one of the most important pollutants in aquatic fresh waters. Heavy metals can be found in the form of components dissolved in these waters or in compounds with suspended particles and surface sediments. It can be said that heavy metals are in equilibrium between water and sediment. In this study, the amount of heavy metals is determined in water and different sizes of sediment. To obtain the relationship between heavy metals in water and size-fractionated sediments, a canonical correlation analysis (CCA) was utilized in rivers of the southwestern Caspian Sea. In this research, a case study was carried out on 18 sampling stations in nine rivers. In the first step, the concentrations of heavy metals (Cu, Zn, Cr, Fe, Mn, Pb, Ni, and Cd) were determined in water and size-fractionated sediment samples. Water sampling sites were classified by hierarchical cluster analysis (HCA) utilizing squared Euclidean distance with Ward's method. In addition, for interpreting the obtained results and the relationships between the concentration of heavy metals in the tested river water and sample sediments, canonical correlation analysis (CCA) was utilized. The rivers were grouped into two classes (those having no pollution and those having low pollution) based on the HCA results obtained for river water samples. CCA results found numerous relationships between rivers in Iran's Guilan province and their size-fractionated sediments samples. The heavy metals of sediments with 0.038 to 0.125 mm size in diameter are slightly correlated with those of water samples.

  20. Spatial and temporal variations in prehistoric human settlement and their influencing factors on the south bank of the Xar Moron River, Northeastern China

    Science.gov (United States)

    Jia, Xin; Yi, Shuangwen; Sun, Yonggang; Wu, Shuangye; Lee, Harry F.; Wang, Lin; Lu, Huayu

    2017-03-01

    The West Liao River Basin is the hub of ancient civilizations as well as the birthplace of rain-fed agriculture in Northern China. In the present study, based on 276 archaeological sites on the south bank of the Xar Moron River, Northeastern China, we trace the changes in prehistoric cultures as well as the shifts in the spatial and temporal patterns of human settlement in the West Liao River Basin. Location information for those sites was obtained from fieldwork. Factors such as climate change, landform evolution of the Horqin Dunefield, and subsistence strategies practiced at the sites were extracted via the meta-analysis of published literature. Our results show that the Holocene Optimum promoted the emergence of Neolithic Culture on the south bank of the Xar Moron River. Monsoon failure might have caused the periodic collapse or transformation of prehistoric cultures at (6.5, 4.7, 3.9, and 3.0) kyr B.P., leaving spaces for new cultural types to develop after these gaps. The rise and fall of different cultures was also determined by subsistence strategies. The Xiaoheyan Culture, with mixed modes of subsistence, weakened after 4.7 kyr B.P., whereas the Upper Xiajiadian Culture, supported by sheep breeding, expanded after 3.0 kyr B.P. Global positioning system data obtained from the archaeological sites reveal that cultures with different subsistence strategies occupied distinct geographic regions. Humans who subsisted on hunting and gathering resided at higher altitudes during the Paleolithic Age (1074 m a.s.l.). Mixed subsistence strategies led humans to settle down at 600-1000 m a.s.l. in the Neolithic Age. Agricultural activities caused humans to migrate to 400-800 m a.s.l. in the early Bronze Age, whereas livestock production shifted human activities to 800-1200 m a.s.l. in the late Bronze Age.

  1. Spatial and temporal variations in prehistoric human settlement and their influencing factors on the south bank of the Xar Moron River, Northeastern China

    Science.gov (United States)

    Jia, Xin; Yi, Shuangwen; Sun, Yonggang; Wu, Shuangye; Lee, Harry F.; Wang, Lin; Lu, Huayu

    2016-05-01

    The West Liao River Basin is the hub of ancient civilizations as well as the birthplace of rain-fed agriculture in Northern China. In the present study, based on 276 archaeological sites on the south bank of the Xar Moron River, Northeastern China, we trace the changes in prehistoric cultures as well as the shifts in the spatial and temporal patterns of human settlement in the West Liao River Basin. Location information for those sites was obtained from fieldwork. Factors such as climate change, landform evolution of the Horqin Dunefield, and subsistence strategies practiced at the sites were extracted via the meta-analysis of published literature. Our results show that the Holocene Optimum promoted the emergence of Neolithic Culture on the south bank of the Xar Moron River. Monsoon failure might have caused the periodic collapse or transformation of prehistoric cultures at (6.5, 4.7, 3.9, and 3.0) kyr B.P., leaving spaces for new cultural types to develop after these gaps. The rise and fall of different cultures was also determined by subsistence strategies. The Xiaoheyan Culture, with mixed modes of subsistence, weakened after 4.7 kyr B.P., whereas the Upper Xiajiadian Culture, supported by sheep breeding, expanded after 3.0 kyr B.P. Global positioning system data obtained from the archaeological sites reveal that cultures with different subsistence strategies occupied distinct geographic regions. Humans who subsisted on hunting and gathering resided at higher altitudes during the Paleolithic Age (1074 m a.s.l.). Mixed subsistence strategies led humans to settle down at 600-1000 m a.s.l. in the Neolithic Age. Agricultural activities caused humans to migrate to 400-800 m a.s.l. in the early Bronze Age, whereas livestock production shifted human activities to 800-1200 m a.s.l. in the late Bronze Age.

  2. Late Quaternary stream piracy and strath terrace formation along the Belle Fourche and lower Cheyenne Rivers, South Dakota and Wyoming

    Science.gov (United States)

    Stamm, John F.; Hendricks, Robert R.; Sawyer, J. Foster; Mahan, Shannon; Zaprowski, Brent J.; Geibel, Nicholas M.; Azzolini, David C.

    2013-01-01

    Stream piracy substantially affected the geomorphic evolution of the Missouri River watershed and drainages within, including the Little Missouri, Cheyenne, Belle Fourche, Bad, and White Rivers. The ancestral Cheyenne River eroded headward in an annular pattern around the eastern and southern Black Hills and pirated the headwaters of the ancestral Bad and White Rivers after ~ 660 ka. The headwaters of the ancestral Little Missouri River were pirated by the ancestral Belle Fourche River, a tributary to the Cheyenne River that currently drains much of the northern Black Hills. Optically stimulated luminescence (OSL) dating techniques were used to estimate the timing of this piracy event at ~ 22–21 ka. The geomorphic evolution of the Cheyenne and Belle Fourche Rivers is also expressed by regionally recognized strath terraces that include (from oldest to youngest) the Sturgis, Bear Butte, and Farmingdale terraces. Radiocarbon and OSL dates from fluvial deposits on these terraces indicate incision to the level of the Bear Butte terrace by ~ 63 ka, incision to the level of the Farmingdale terrace at ~ 40 ka, and incision to the level of the modern channel after ~ 12–9 ka. Similar dates of terrace incision have been reported for the Laramie and Wind River Ranges. Hypothesized causes of incision are the onset of colder climate during the middle Wisconsinan and the transition to the full-glacial climate of the late-Wisconsinan/Pinedale glaciation. Incision during the Holocene of the lower Cheyenne River is as much as ~ 80 m and is 3 to 4 times the magnitude of incision at ~ 63 ka and ~ 40 ka. The magnitude of incision during the Holocene might be due to a combined effect of three geomorphic processes acting in concert: glacial isostatic rebound in lower reaches (~ 40 m), a change from glacial to interglacial climate, and adjustments to increased watershed area resulting from piracy of the ancestral headwaters of the Little Missouri River.

  3. Late Quaternary stream piracy and strath terrace formation along the Belle Fourche and lower Cheyenne Rivers, South Dakota and Wyoming

    Science.gov (United States)

    Stamm, John F.; Hendricks, Robert R.; Sawyer, J. Foster; Mahan, Shannon A.; Zaprowski, Brent J.; Geibel, Nicholas M.; Azzolini, David C.

    2013-09-01

    Stream piracy substantially affected the geomorphic evolution of the Missouri River watershed and drainages within, including the Little Missouri, Cheyenne, Belle Fourche, Bad, and White Rivers. The ancestral Cheyenne River eroded headward in an annular pattern around the eastern and southern Black Hills and pirated the headwaters of the ancestral Bad and White Rivers after ~ 660 ka. The headwaters of the ancestral Little Missouri River were pirated by the ancestral Belle Fourche River, a tributary to the Cheyenne River that currently drains much of the northern Black Hills. Optically stimulated luminescence (OSL) dating techniques were used to estimate the timing of this piracy event at ~ 22-21 ka. The geomorphic evolution of the Cheyenne and Belle Fourche Rivers is also expressed by regionally recognized strath terraces that include (from oldest to youngest) the Sturgis, Bear Butte, and Farmingdale terraces. Radiocarbon and OSL dates from fluvial deposits on these terraces indicate incision to the level of the Bear Butte terrace by ~ 63 ka, incision to the level of the Farmingdale terrace at ~ 40 ka, and incision to the level of the modern channel after ~ 12-9 ka. Similar dates of terrace incision have been reported for the Laramie and Wind River Ranges. Hypothesized causes of incision are the onset of colder climate during the middle Wisconsinan and the transition to the full-glacial climate of the late-Wisconsinan/Pinedale glaciation. Incision during the Holocene of the lower Cheyenne River is as much as ~ 80 m and is 3 to 4 times the magnitude of incision at ~ 63 ka and ~ 40 ka. The magnitude of incision during the Holocene might be due to a combined effect of three geomorphic processes acting in concert: glacial isostatic rebound in lower reaches (~ 40 m), a change from glacial to interglacial climate, and adjustments to increased watershed area resulting from piracy of the ancestral headwaters of the Little Missouri River.

  4. Low-flow frequency and flow duration of selected South Carolina streams in the Savannah and Salkehatchie River Basins through March 2014

    Science.gov (United States)

    Feaster, Toby D.; Guimaraes, Wladmir B.

    2016-07-14

    An ongoing understanding of streamflow characteristics of the rivers and streams in South Carolina is important for the protection and preservation of the State’s water resources. Information concerning the low-flow characteristics of streams is especially important during critical flow periods, such as during the historic droughts that South Carolina has experienced in the past few decades.In 2008, the U.S. Geological Survey, in cooperation with the South Carolina Department of Health and Environmental Control, initiated a study to update low-flow statistics at continuous-record streamgaging stations operated by the U.S. Geological Survey in South Carolina. This report presents the low-flow statistics for 28 selected streamgaging stations in the Savannah and Salkehatchie River Basins in South Carolina. The low-flow statistics include daily mean flow durations for the 5-, 10-, 25-, 50-, 75-, 90-, and 95-percent probability of exceedance and the annual minimum 1-, 3-, 7-, 14-, 30-, 60-, and 90-day mean flows with recurrence intervals of 2, 5, 10, 20, 30, and 50 years, depending on the length of record available at the streamgaging station. The low-flow statistics were computed from records available through March 31, 2014.Low-flow statistics are influenced by length of record, hydrologic regime under which the data were collected, analytical techniques used, and other factors, such as urbanization, diversions, and droughts that may have occurred in the basin. To assess changes in the low-flow statistics from the previously published values, a comparison of the low-flow statistics for the annual minimum 7-day average streamflow with a 10-year recurrence interval (7Q10) from this study was made with the most recently published values. Of the 28 streamgaging stations for which recurrence interval computations were made, 14 streamgaging stations were suitable for comparing to low-flow statistics that were previously published in U.S. Geological Survey reports. These

  5. Modelling sediment-microbial dynamics in the South Nation River, Ontario, Canada: Towards the prediction of aquatic and human health risk.

    Science.gov (United States)

    Droppo, I G; Krishnappan, B G; Liss, S N; Marvin, C; Biberhofer, J

    2011-06-01

    Runoff from agricultural watersheds can carry a number of agricultural pollutants and pathogens; often associated with the sediment fraction. Deposition of this sediment can impact water quality and the ecology of the river, and the re-suspension of such sediment can become sources of contamination for reaches downstream. In this paper a modelling framework to predict sediment and associated microbial erosion, transport and deposition is proposed for the South Nation River, Ontario, Canada. The modelling framework is based on empirical relationships (deposition and re-suspension fluxes), derived from laboratory experiments in a rotating circular flume using sediment collected from the river bed. The bed shear stress governing the deposition and re-suspension processes in the stream was predicted using a one dimensional mobile boundary flow model called MOBED. Counts of live bacteria associated with the suspended and bed sediments were used in conjunction with measured suspended sediment concentration at an upstream section to allow for the estimation of sediment associated microbial erosion, transport and deposition within the modelled river reach. Results suggest that the South Nation River is dominated by deposition periods with erosion only occurring at flows above approximately 250 m(3) s(-1) (above this threshold, all sediment (suspended and eroded) with associated bacteria are transported through the modelled reach). As microbes are often associated with sediments, and can survive for extended periods of time, the river bed is shown to be a possible source of pathogenic organisms for erosion and transport downstream during large storm events. It is clear that, shear levels, bacteria concentrations and suspended sediment are interrelated requiring that these parameters be studied together in order to understand aquatic microbial dynamics. It is important that any management strategies and operational assessments for the protection of human and aquatic health

  6. Intensive archaeological survey of the proposed Savannah River Ecology Laboratory Conference Center and Educational Facility, Savannah River Site, Aiken County, South Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Stephenson, K.; Crass, D.C.; Sassaman, K.E.

    1993-02-01

    Documented in this report are the methods and results of an intensive archaeological survey for the proposed University of Georgia Savannah River Ecology Laboratory (SREL) Conference Center and Educational Facility on the DOE Savannah River Site (SRS). Archaeological investigations conducted by the Savannah River Archaeological Research Program (SRARP) on the 70-acre project area and associated rights-of-way consisted of subsurface testing at two previously recorded sites and the discovery of one previously unrecorded site. The results show that 2 sites contain archaeological remains that may yield significant information about human occupations in the Aiken Plateau and are therefore considered eligible for nomination to the National Register of Historic Places. Adverse impacts to these sites can be mitigated through avoidance.

  7. Characterizing rates and mechanisms of soil transport using tephra as a tracer: Charwell River, South Island, New Zealand

    Science.gov (United States)

    Roering, J. J.; Almond, P.; Tonkin, P.; McKean, J.

    2001-12-01

    Downslope transport of soil in the absence of overland flow has been attributed to numerous mechanisms, including particle-by-particle rheologic creep and disturbances associated with biological activity. Process stochasticity and difficulties associated with field measurement have obscured the characterization of long-term soil transport rates and mechanisms. Most modeling studies represent soil transport as a slope and/or soil depth-dependent process, although field evidence is sparse. At our study site along incised fluvial terraces of the Charwell River, South Island, New Zealand, we documented vertical profiles of tephra concentration along a hillslope transect to quantify soil transport. Near the relatively undissected hilltop, we observed a 10 cm thick primary tephra layer (ca 22.6 kyr) within loess deposits approximately 80 cm below the landscape surface. In the downslope direction, the depth to the highly concentrated tephra layer decreases, coincident with an increase in hillslope convexity (which is proportional to erosion rate if soil flux varies linearly with hillslope gradient). Exhumation of the spike in tephra concentration results from landscape lowering due to soil transport processes as evidence for overland flow erosion is lacking. Approximately 20 m downslope of the hilltop, where the depth to the tephra spike declines to 40-50 cm, peak concentrations decrease by a factor of 4 and tephra is distributed uniformly within the upper 40 cm of soil. Further downslope near the valley margin, we observed low and relatively uniform tephra concentrations in the upper soil. The transition from a thin, highly concentrated tephra layer at depth to sparse, widely distributed tephra within the upper soil column may result from soil mixing and transport by tree and plant root activity. The depth of this transition is approximately 50 cm along our transect, coincident with the rooting depth of Podocarpus trees that populated the area through much of the

  8. The Crati River Basin: geomorphological and stratigraphical data for the Plio–Quaternary evolution of northern Calabria, South Apennines, Italy

    Directory of Open Access Journals (Sweden)

    Robustelli Gaetano

    2017-02-01

    Full Text Available In this paper, we present the results of an integrated geomorphological and stratigraphical study carried out in the eastern side of the Crati River valley (northern Calabria, South Italy. This area is characterized by the occurrence of three order palaeosurfaces that, along with low-sloping palaeovalleys and structural landforms, are striking features of the landscape. The relationships between morpho-tectonic and sedimentary evolution of the Crati Basin has been assessed through sandstone detrital modes, morphostratigraphy and geomorphological correlation with adjacent areas. The two main unconformity surfaces that typify the Quaternary fill were correlated to different steps of landscape evolution. The presence of both erosional and depositional palaeosurfaces has been a useful marker for reconstructing sedimentary and morphogenetic events, and hence to detect drainage network evolution and changes in source sediment area. In particular, we recognized that the study area experienced, during the late Pliocene–Early Pleistocene a period of sub-aerial landscape modelling as suggested by low-sloping palaeovalleys and related fluvial deposits (1st Order Palaeosurface. At that time, the source of the detrital constituents of the PPS Unit sandstones was mainly from the Sila Massif. The onset of Coastal Range identification and uplift (Early Pleistocene marks a change in the geomorphic scenario with tectonic driven stream incision and valley development along the eastern side of Coastal Range, along with the occurrence of depositional and erosional landsurfaces (2nd Order Palaeosurface at footslopes. During this period, the Coastal Range and Sila Massif were the sources for the detrital constituents of the PlS Unit sandstones. The progressive uplift of Coastal Range during late Early Pleistocene and the marked backstepping of the depositional systems along the Sila footslope was accompanied by alternating phases of down-cutting and base

  9. Organosulfates from pinene and isoprene over the Pearl River Delta, South China: seasonal variation and implication in formation mechanisms.

    Science.gov (United States)

    He, Quan-Fu; Ding, Xiang; Wang, Xin-Ming; Yu, Jian-Zhen; Fu, Xiao-Xin; Liu, Teng-Yu; Zhang, Zhou; Xue, Jian; Chen, Duo-Hong; Zhong, Liu-Ju; Donahue, Neil M

    2014-08-19

    Biogenic organosulfates (OSs) are important markers of secondary organic aerosol (SOA) formation involving cross reactions of biogenic precursors (terpenoids) with anthropogenic pollutants. Until now, there has been rare information about biogenic OSs in the air of highly polluted areas. In this study, fine particle (PM2.5) samples were separately collected in daytime and nighttime from summer to fall 2010 at a site in the central Pearl River Delta (PRD), South China. Pinene-derived nitrooxy-organosulfates (pNOSs) and isoprene-derived OSs (iOSs) were quantified using a liquid chromatograph (LC) coupled with a tandem mass spectrometer (MS/MS) operated in negative electrospray ionization (ESI) mode. The pNOSs with MW 295 exhibited higher levels in fall (151 ± 86.9 ng m(-3)) than summer (52.4 ± 34.0 ng m(-3)), probably owing to the elevated levels of NOx and sulfate in fall when air masses mainly passed through city clusters in the PRD and biomass burning was enhanced. In contrast to observations elsewhere where higher levels occurred at nighttime, pNOS levels in the PRD were higher during the daytime in both seasons, indicating that pNOS formation was likely driven by photochemistry over the PRD. This conclusion is supported by several lines of evidence: the specific pNOS which could be formed through both daytime photochemistry and nighttime NO3 chemistry exhibited no day-night variation in abundance relative to other pNOS isomers; the production of the hydroxynitrate that is the key precursor for this specific pNOS was found to be significant through photochemistry but negligible through NO3 chemistry based on the mechanisms in the Master Chemical Mechanism (MCM). For iOSs, 2-methyltetrol sulfate ester which could be formed from isoprene-derived epoxydiols (IEPOX) under low-NOx conditions showed low concentrations (below the detection limit to 2.09 ng m(-3)), largely due to the depression of IEPOX formation by the high NOx levels over the PRD.

  10. The Crati River Basin: geomorphological and stratigraphical data for the Plio-Quaternary evolution of northern Calabria, South Apennines, Italy

    Science.gov (United States)

    Robustelli, Gaetano; Muto, Francesco

    2017-02-01

    In this paper, we present the results of an integrated geomorphological and stratigraphical study carried out in the eastern side of the Crati River valley (northern Calabria, South Italy). This area is characterized by the occurrence of three order palaeosurfaces that, along with low-sloping palaeovalleys and structural landforms, are striking features of the landscape. The relationships between morpho-tectonic and sedimentary evolution of the Crati Basin has been assessed through sandstone detrital modes, morphostratigraphy and geomorphological correlation with adjacent areas. The two main unconformity surfaces that typify the Quaternary fill were correlated to different steps of landscape evolution. The presence of both erosional and depositional palaeosurfaces has been a useful marker for reconstructing sedimentary and morphogenetic events, and hence to detect drainage network evolution and changes in source sediment area. In particular, we recognized that the study area experienced, during the late Pliocene-Early Pleistocene a period of sub-aerial landscape modelling as suggested by low-sloping palaeovalleys and related fluvial deposits (1st Order Palaeosurface). At that time, the source of the detrital constituents of the PPS Unit sandstones was mainly from the Sila Massif. The onset of Coastal Range identification and uplift (Early Pleistocene) marks a change in the geomorphic scenario with tectonic driven stream incision and valley development along the eastern side of Coastal Range, along with the occurrence of depositional and erosional landsurfaces (2nd Order Palaeosurface) at footslopes. During this period, the Coastal Range and Sila Massif were the sources for the detrital constituents of the PlS Unit sandstones. The progressive uplift of Coastal Range during late Early Pleistocene and the marked backstepping of the depositional systems along the Sila footslope was accompanied by alternating phases of down-cutting and base-level stability resulting in

  11. In situ fate and partitioning of waterborne perfluoroalkyl acids (PFAAs) in the Youngsan and Nakdong River Estuaries of South Korea

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Seongjin [School of Earth and Environmental Sciences, Seoul National University, Seoul (Korea, Republic of); Khim, Jong Seong, E-mail: jskocean@snu.ac.kr [School of Earth and Environmental Sciences, Seoul National University, Seoul (Korea, Republic of); Park, Jinsoon [School of Earth and Environmental Sciences, Seoul National University, Seoul (Korea, Republic of); Kim, Minhee; Kim, Woong-Ki; Jung, Jinho; Hyun, Seunghun; Kim, Jeong-Gyu [Division of Environmental Science and Ecological Engineering, Korea University, Seoul (Korea, Republic of); Lee, Hyojin; Choi, Heeseon J. [Department of Environmental Chemistry and Ecology, GeoSystem Research Corporation, Gunpo (Korea, Republic of); Codling, Garry [Department of Veterinary Biomedical Sciences and Toxicology Centre, University of Saskatchewan, Saskatoon, SK (Canada); Giesy, John P. [Department of Veterinary Biomedical Sciences and Toxicology Centre, University of Saskatchewan, Saskatoon, SK (Canada); Department of Zoology, Center for Integrative Toxicology, Michigan State University, East Lansing, MI (United States); Department of Biology and Chemistry and State Key Laboratory in Marine Pollution, City University of Hong Kong, Kowloon, Hong Kong, SAR (China)

    2013-02-15

    Concentrations, distributions, fate, and partitioning of perfluoroalkyl acids (PFAAs) were investigated in surface water (n = 34) collected from the Youngsan and Nakdong River Estuaries of South Korea. Thirteen individual PFAAs in water and suspended solids (SS) were quantified by use of HPLC–MS/MS. PFAAs were detected in all samples, which indicated that they were widely distributed in the study area. Greater concentrations of PFAAs were found at some inland sites which seemed to be affected by direct input from point sources, such as wastewater treatment plants, and/or indirect diffusive sources, such as surface runoff. Spatial distributions of PFAAs in estuaries along transects toward the open sea demonstrated that these chemicals were transported to the outer region primarily by water discharged during the rainy season. Field-based partition coefficients (K{sub d}) for long-chain PFAAs (C ≥ 8) were significantly correlated with salinity (r{sup 2} = 0.48 to 0.73, p < 0.01); K{sub d} values increased exponentially as a function of salinity. Due to the ‘salting-out’ effect, PFAAs were largely scavenged by adsorption onto SS and/or sediments in estuarine environments. In addition, values for K{sub d} of those PFAAs were directly proportional to the number of carbon atoms in the PFAAs. Salting constants of selected PFAAs were notably greater than those of other environmental organic contaminants, which indicated that adsorption of PFAAs is largely associated with salinity. Overall, the results of the present study will provide better understanding of the fate and transport of PFAAs in the zone of salinity boundary that can be used for developing fate models of PFAAs in the coastal marine environment. - Highlights: ► In situ fate and partitioning of PFAAs were described along salinity gradients in estuaries. ► Salinity was found to be the key factor controlling adsorption of waterborne PFAAs. ► The K{sub d} for longer-chain PFAAs (C ≥ 8) increased as

  12. Morphological description and ecology of some rare macroalgae in south-central Spanish rivers (Castilla-La Mancha Region

    Directory of Open Access Journals (Sweden)

    Moreno Alcaraz, Jose Luis

    2013-06-01

    Full Text Available The Castilla-La Mancha Region (south-central Spain is scarcely studied in terms of freshwater algae. However, both the implementation of the Water Framework Directive (2000/60/CE and the evaluation of the ecological state of European aquatic ecosystems have increased the intensity and frequency of water body monitoring, including the rivers, lakes and wetlands of this region. Thus, our knowledge on algal biodiversity and the geographical distribution of many species is rapidly increasing. In this study we describe the occurrence, ecological conditions and morphological characteristics of five algal species which are rare at the European level: Nostochopsis lobata Wood ex Bornet & Flahault, Batrachospermum atrum (Hudson Harvey, Chroothece richteriana Hansg., Oocardium stratum Nägeli and Tetrasporidium javanicum Möbius. In addition, we include Hydrurus foetidus (Vill. Trev., a more common alga in Spain, since this is the first record for the region. Finally, we compare morphological and ecological characteristics of the studied populations with other European records.El conocimiento sobre la biodiversidad algal de la región de Castilla-La Mancha, situada en la zona centro-sur de España, es escaso en comparación con el de otras regiones peninsulares. Sin embargo, la aplicación de la Directiva Marco del Agua (2000/60/CE, y la evaluación del estado ecológico de los ecosistemas acuáticos europeos, ha traído consigo un aumento en la frecuencia e intensidad en el muestreo de ríos, lagos y humedales. De esta forma, durante los últimos años se han producido nuevos hallazgos en la región que han permitido ampliar el conocimiento de la biodiversidad de algas así como de la distribución geográfica de muchas de sus especies. En este trabajo se describen las condiciones ecológicas y las características morfológicas de cinco especies que pueden considerarse raras a nivel europeo: Nostochopsis lobata Wood & Bornet & Flahault, Batrachospermum

  13. Spatial and temporal variations of water quality in an artificial urban river receiving WWTP effluent in South China.

    Science.gov (United States)

    Zhang, Di; Tao, Yi; Liu, Xiaoning; Zhou, Kuiyu; Yuan, Zhenghao; Wu, Qianyuan; Zhang, Xihui

    2016-01-01

    Urban wastewater treatment plant (WWTP) effluent as reclaimed water provides an alternative water resource for urban rivers and effluent will pose a significant influence on the water quality of rivers. The objective of this study was to investigate the spatial and temporal variations of water quality in XZ River, an artificial urban river in Shenzhen city, Guangdong Province, China, after receiving reclaimed water from WWTP effluent. The water samples were collected monthly at different sites of XZ River from April 2013 to September 2014. Multivariate statistical techniques and a box-plot were used to assess the variations of water quality and to identify the main pollution factor. The results showed the input of WWTP effluent could effectively increase dissolved oxygen, decrease turbidity, phosphorus load and organic pollution load of XZ River. However, total nitrogen and nitrate pollution loads were found to remain at higher levels after receiving reclaimed water, which might aggravate eutrophication status of XZ River. Organic pollution load exhibited the lowest value on the 750 m downstream of XZ River, while turbidity and nutrient load showed the lowest values on the 2,300 m downstream. There was a higher load of nitrogen and phosphorus pollution in the dry season and at the beginning of wet season.

  14. Management approaches for improving environmental restoration at the Savannah River Site: Projectization, performance, and communications; Savannah River Site, Aiken, South Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Pope, J.M.; Hoffman, W.D. (Westinghouse Savannah River Co., Aiken, SC (United States)); Goidell, L. (USDOE, Washington, DC (United States))

    1993-01-01

    The purpose of this paper is to communicate how new and established management techniques are applied to environmental restoration projects at the Savannah River Site. Specifically, the paper discusses application of four (4) management approaches: Total Quality Principles; Task Team Structure; Cost Time Management; SAFER (Streamlined Approach for Environmental Restoration). The objective is to share Savannah River Site experience and document case studies where certain approaches have enhanced projects at hand. Each management approach is demonstrated by its project application and impact on performance. The visibility given the project is discussed to emphasize communications as avenues for public information, technical exchange, and employee motivation.

  15. Management approaches for improving environmental restoration at the Savannah River Site: Projectization, performance, and communications; Savannah River Site, Aiken, South Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Pope, J.M.; Hoffman, W.D. [Westinghouse Savannah River Co., Aiken, SC (United States); Goidell, L. [USDOE, Washington, DC (United States)

    1993-02-01

    The purpose of this paper is to communicate how new and established management techniques are applied to environmental restoration projects at the Savannah River Site. Specifically, the paper discusses application of four (4) management approaches: Total Quality Principles; Task Team Structure; Cost Time Management; SAFER (Streamlined Approach for Environmental Restoration). The objective is to share Savannah River Site experience and document case studies where certain approaches have enhanced projects at hand. Each management approach is demonstrated by its project application and impact on performance. The visibility given the project is discussed to emphasize communications as avenues for public information, technical exchange, and employee motivation.

  16. Concentrations of selected metals in Quaternary-age fluvial deposits along the lower Cheyenne and middle Belle Fourche Rivers, western South Dakota, 2009-10

    Science.gov (United States)

    Stamm, John F.; Hoogestraat, Galen K.

    2012-01-01

    The headwaters of the Cheyenne and Belle Fourche Rivers drain the Black Hills of South Dakota and Wyoming, an area that has been affected by mining and ore-milling operations since the discovery of gold in 1875. A tributary to the Belle Fourche River is Whitewood Creek, which drains the area of the Homestake Mine, a gold mine that operated from 1876 to 2001. Tailings discharged into Whitewood Creek contained arsenopyrite, an arsenic-rich variety of pyrite associated with gold ore, and mercury used as an amalgam during the gold-extraction process. Approximately 18 percent of the tailings that were discharged remain in fluvial deposits on the flood plain along Whitewood Creek, and approximately 25 percent remain in fluvial deposits on the flood plain along the Belle Fourche River, downstream from Whitewood Creek. In 1983, a 29-kilometer (18-mile) reach of Whitewood Creek and the adjacent flood plain was included in the U.S. Environmental Protection Agency's National Priority List of the Comprehensive Environmental Response, Compensation, and Liability Act of 1980, commonly referred to as a "Superfund site." Listing of this reach of Whitewood Creek was primarily in response to arsenic toxicity of fluvial deposits on the flood plain. Lands along the lower Cheyenne River were transferred to adjoining States and Tribes in response to the Water Resources Development Act (WRDA) of 1999. An amendment in 2000 to WRDA required a study of sediment contamination of the Cheyenne River. In response to the WRDA amendment, the U.S. Geological Survey completed field sampling of reference sites (not affected by mine-tailing disposal) along the lower Belle Fourche and lower Cheyenne Rivers. Reference sites were located on stream terraces that were elevated well above historical stream stages to ensure no contamination from historical mining activity. Sampling of potentially contaminated sites was performed on transects of the active flood plain and adjacent terraces that could

  17. Chapter A. Effects of urbanization on stream ecosystems in the South Platte River basin, Colorado and Wyoming

    Science.gov (United States)

    Sprague, Lori A.; Zuellig, Robert E.; Dupree, Jean A.

    2006-01-01

    This report describes the effects of urbanization on physical, chemical, and biological characteristics of stream ecosystems in 28 basins along an urban land-use gradient in the South Platte River Basin, Colorado and Wyoming, from 2002 through 2003. Study basins were chosen to minimize natural variability among basins due to factors such as geology, elevation, and climate and to maximize coverage of different stages of urban development among basins. Because land use or population density alone often are not a complete measure of urbanization, land use, land cover, infrastructure, and socioeconomic variables were integrated in a multimetric urban intensity index to represent the degree of urban development in each study basin. Physical characteristics studied included stream hydrology, stream temperature, and habitat; chemical characteristics studied included nutrients, pesticides, suspended sediment, sulfate, chloride, and fecal bacteria concentrations; and biological characteristics studied included algae, fish, and invertebrate communities. Semipermeable membrane devices (SPMDs), passive samplers that concentrate trace levels of hydrophobic organic contaminants like polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), also were used. The objectives of the study were to (1) examine physical, chemical, and biological responses along the gradient of urbanization; (2) determine the major physical, chemical, and landscape variables affecting the structure of aquatic communities; and (3) evaluate the relevance of the results to the management of water resources in the South Platte River Basin. Commonly observed effects of urbanization on instream physical, chemical, and biological characteristics, such as increased flashiness, higher magnitude and more frequent peak flows, increased concentrations of chemicals, and changes in aquatic community structure, generally were not observed in this study. None of the hydrologic, temperature, habitat

  18. Controls on dryland mountain landscape development along the NW Saharan desert margin: Insights from Quaternary river terrace sequences (Dadès River, south-central High Atlas, Morocco)

    Science.gov (United States)

    Stokes, M.; Mather, A. E.; Belfoul, M.; Faik, F.; Bouzid, S.; Geach, M. R.; Cunha, P. P.; Boulton, S. J.; Thiel, C.

    2017-06-01

    This study documents river terraces from upstream reaches of the Dadès River, a major fluvial system draining the south-central High Atlas Mountains. Terraces occur as straths with bedrock bases positioned at 10 m altitudinal intervals up to 40 m (T1-T5) above the valley floor, becoming less common between 50 and 140 m. The rock strength, stratigraphy and structure of the mountain belt influences terrace distribution. Terraces are absent in river gorges of structurally thickened limestone; whilst well-developed, laterally continuous terraces (T1-T4) form along wide valleys occupying syncline structures dominated by weaker interbedded limestone-mudstone. Terrace staircases develop in confined canyons associated with weaker lithologies and influence from structural dip and stratigraphic configuration. Terraces comprise a bedrock erosion surface overlain by fluvial conglomerates, rare overbank sands and colluvium. This sequence with some OSL/IRSL age control, suggests terrace formation over a 100 ka climate cycle with valley floor aggradation during full glacials and incision during glacial-interglacial transitions. This integrates with other archives (e.g. lakes, glaciers, dunes), appearing typical of landscape development along the NW Saharan margin south of the High Atlas, and similar to patterns in the western-southern Mediterranean. The 100 ka climate cycle relationship suggests that the terrace sequence documents Late-Middle Pleistocene landscape development. Consistent altitudinal spacing of terraces and their distribution throughout the orogen suggests sustained base-level lowering linked to uplift-exhumation of the High Atlas. Low incision rates (<0.2 mm a-1) and general absence of terrace deformation suggests dominance of isostatically driven base-level lowering with relief generation being Early Pleistocene or older.

  19. An assessment of selected hydrochemical parameter trend of the Nakdong River water in South Korea, using time series analyses and PCA.

    Science.gov (United States)

    Chung, S Y; Venkatramanan, S; Park, N; Rajesh, R; Ramkumar, T; Kim, B W

    2015-01-01

    Time series analyses (autocorrelation, spectral density, and cross-correlation) and principal component analysis (PCA) were used to understand the characteristics of the selected hydrochemical parameters pH, turbidity, alkalinity, Cl, hardness, total dissolved solids (TDS), and metals Fe and Mn in the Nakdong River, South Korea. Autocorrelation and spectral density for pH, alkalinity, hardness, and Cl were very similar to TDS, whereas Fe, Mn, and turbidity showed different trends from TDS. Cross-correlograms of pH, alkalinity, hardness, and Cl versus TDS were very similar to each other. Those of Fe and turbidity represented the opposite relations with other components. Cross-correlation coefficients had the highest values at zero lag, indicating that pH, alkalinity, hardness, and Cl are controlling factors for TDS. On the other hand, Fe and turbidity showed the highest values at 6-month lag and Mn at a month lag. PCA indicated that TDS had very close relation with hardness, pH, and Cl and very small relation with Mn. Turbidity and Fe had relatively opposite relations with TDS. It was concluded that the geostatistical methods were very useful for evaluating the hydrochemical characteristics of the Nakdong River water in South Korea.

  20. Spatial distribution and vertical profile of polybrominated diphenyl ethers, tetrabromobisphenol A, and decabromodiphenylethane in river sediment from an industrialized region of South China

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Xiulan [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Graduate School of the Chinese Academy of Science, Beijing 100039 (China); Luo Xiaojun, E-mail: luoxiaoj@gig.ac.c [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Chen Shejun [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Wu Jiangping [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Graduate School of the Chinese Academy of Science, Beijing 100039 (China); Mai Bixian [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China)

    2009-06-15

    Polybrominated diphenyl ethers (PBDEs), tetrabromobisphenol A (TBBPA), and decabromodiphenylethane (DBDPE) were detected in fifteen surface sediments and two sediment cores collected from a river in one heavily industrialized region of South China. TBBPA and DBDPE were detected with concentrations ranging from 3.8 to 230 ng/g dw and from 23 to 430 ng/g dw, respectively. SIGMAtri-hepta-BDEs and SIGMAnona-deca-BDEs ranged from 0.7 to 7.6 ng/g dw and from 30 to 5700 ng/g dw, respectively. SIGMAtri-hepta-BDEs showed an increasing trend whereas for SIGMAnona-deca-BDE two sediment cores revealed a decreasing trend in more recent sediment layers which may attributed to the introduction of DBDPE. The rapid increasing trend for TBBPA and DBDPE in recent sediment layers well reflected the rising demand of these two compounds in study area. - Ubiquitous and historical contamination by PBDE, TBBPA, and DBDPE in river sediments from an industrialized region of South China

  1. Comparison of single-grain and small-aliquot OSL dose estimates in < 3000 years old river sediments from South India

    DEFF Research Database (Denmark)

    Thomas, P.J.; Jain, M.; Juyal, N.;

    2005-01-01

    We report on OSL dose distributions derived from small-aliquot and single grains of quartz in young fluvial sediments sampled from the Penner River basin, South India. The single-grain dose distributions suggest that 13 out of 19 samples were well bleached. In many well-bleached samples, there wa......We report on OSL dose distributions derived from small-aliquot and single grains of quartz in young fluvial sediments sampled from the Penner River basin, South India. The single-grain dose distributions suggest that 13 out of 19 samples were well bleached. In many well-bleached samples......, there was an underestimation in the single-aliquot dose estimates as compared to those from the single grain-the difference between average dose estimates determined by the two methods ranged from similar to 1% to 31%. Such a dose underestimation was not detectable in poorly bleached samples. Various possible reasons...... for the discrepancy between single-grain and small-aliquot dose estimates are discussed. Although there is no satisfactory explanation for this discrepancy, we speculate that the difference in the stimulation wavelengths, 470 +/- 130 nm in the case of single-aliquot and 532 nm in the case of single grains, could...

  2. Evaluation of groundwater levels in the South Platte River alluvial aquifer, Colorado, 1953-2012, and design of initial well networks for monitoring groundwater levels

    Science.gov (United States)

    Wellman, Tristan

    2015-01-01

    The South Platte River and underlying alluvial aquifer form an important hydrologic resource in northeastern Colorado that provides water to population centers along the Front Range and to agricultural communities across the rural plains. Water is regulated based on seniority of water rights and delivered using a network of administration structures that includes ditches, reservoirs, wells, impacted river sections, and engineered recharge areas. A recent addendum to Colorado water law enacted during 2002-2003 curtailed pumping from thousands of wells that lacked authorized augmentation plans. The restrictions in pumping were hypothesized to increase water storage in the aquifer, causing groundwater to rise near the land surface at some locations. The U.S. Geological Survey (USGS), in cooperation with the Colorado Water Conservation Board and the Colorado Water Institute, completed an assessment of 60 years (yr) of historical groundwater-level records collected from 1953 to 2012 from 1,669 wells. Relations of "high" groundwater levels, defined as depth to water from 0 to 10 feet (ft) below land surface, were compared to precipitation, river discharge, and 36 geographic and administrative attributes to identify natural and human controls in areas with shallow groundwater.

  3. Analysis of Salinity Intrusion in the Waccamaw River and Atlantic Intracoastal Waterway near Myrtle Beach, South Carolina, 1995–2002

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This record is a USGS unpublished report about saltwater intrusion in the Waccamaw River and the Intracoastal Waterway. Six reservoirs in North Carolina discharge...

  4. Bio-accumulation of selected metals in African sharptooth catfish Clarias gariepinus from the lower Olifants River, Mpumalanga, South Africa

    Directory of Open Access Journals (Sweden)

    H.H. Du Preez

    1997-01-01

    Full Text Available The level of metal (Cr, Cu, Mn, Ni, Pb and Zn bio- accumulation in tissues (muscle, gill, kidney, liver and gonads and bile of the African catfish Clarias gariepinus, from the lower Olifants River was investigated. These metals were detected in all the tissues as well as in the bile, with the highest concentration found in either the gills, liver or gonadal tissue. The lowest concentration was usually detected in the muscle tissue. Although statistic comparisons revealed no significant differences between the localities, fish from the Selati River (Locality 1 generally had higher metal levels than fish from the localities along the Olifants River inside the Kruger National Park. The higher levels in the fish from the Selati River may be attributed to anthropogenic activities resulting in point and/or diffuse sources of metal pollution. These sources should be identified and reduced.

  5. LiDAR Data Collection for the James River Watershed and Adjacent Areas in South Dakota and North Dakota

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The collection of LiDAR data for the James River basin began in 2010. The detailed surface elevation data will be used for conservation planning, design, research,...

  6. Aerial photo mosaic of the Powers Reach and Broadbent Reach, South Fork Coquille River, Oregon in 1939

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Coquille River system is an unregulated system that encompasses 2,745 square kilometers of southwestern Oregon and flows into the Pacific Ocean near the town of...

  7. Aerial photo mosaic of the South Fork Coquille, Middle Fork Coquille, North Fork Coquille, and Coquille Rivers, Oregon in 1967

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Coquille River system is an unregulated system that encompasses 2,745 square kilometers of southwestern Oregon and flows into the Pacific Ocean near the town of...

  8. Future Water Management in the South Platte River Basin: Impacts of Hydraulic Fracturing, Population, Agriculture, and Climate Change in a Semi-Arid Region.

    Science.gov (United States)

    Walker, E. L.; Hogue, T. S.; Anderson, A. M.; Read, L.

    2015-12-01

    In semi-arid basins across the world, the gap between water supply and demand is growing due to climate change, population growth, and shifts in agriculture and unconventional energy development. Water conservation efforts among residential and industrial water users, recycling and reuse techniques and innovative regulatory frameworks for water management strive to mitigate this gap, however, the extent of these strategies are often difficult to quantify and not included in modeling water allocations. Decision support systems (DSS) are purposeful for supporting water managers in making informed decisions when competing demands create the need to optimize water allocation between sectors. One region of particular interest is the semi-arid region of the South Platte River basin in northeastern Colorado, where anthropogenic and climatic effects are expected to increase the gap between water supply and demand in the near future. Specifically, water use in the South Platte is impacted by several high-intensity activities, including unconventional energy development, i.e. hydraulic fracturing, and large withdrawals for agriculture; these demands are in addition to a projected population increase of 100% by 2050. The current work describes the development of a DSS for the South Platte River basin, using the Water Evaluation and Planning system software (WEAP) to explore scenarios of how variation in future water use in the energy, agriculture, and municipal sectors will impact water allocation decisions. Detailed data collected on oil and gas water use in the Niobrara shale play will be utilized to predict future sector use. We also employ downscaled climate projections for the region to quantify the potential range of water availability in the basin under each scenario, and observe whether or not, and to what extent, climate may impact management decisions at the basin level.

  9. Detection of antibiotic resistance and tetracycline resistance genes in Enterobacteriaceae isolated from the Pearl rivers in South China

    Energy Technology Data Exchange (ETDEWEB)

    Tao Ran [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Street, Tianhe District, Guangzhou 510640 (China); Ying Guangguo, E-mail: guangguo.ying@gmail.co [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Street, Tianhe District, Guangzhou 510640 (China); Su Haochang [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Street, Tianhe District, Guangzhou 510640 (China); Zhou Hongwei [Department of Environmental Health, School of Public Health and Tropical Medicine, Southern Medical University, 1838 North Guangzhou Street, Baiyun District, Guangzhou 510515 (China); Sidhu, Jatinder P.S. [CSIRO Land and Water, Queensland Bioscience Precinct, 306 Carmody Road, St Lucia QLD 4067 (Australia)

    2010-06-15

    This study investigated antibiotic resistance profiles and tetracycline resistance genes in Enterobacteriaceae family isolates from the Pearl rivers. The Enterobacteriaceae isolates were tested for susceptibility to seven antibiotics ampicillin, chloramphenicol, ciprofloxacin, levofloxacin, sulphamethoxazole/trimethoprim, tetracycline and trimethoprim. In Liuxi reservoir, with an exception to ampicillin resistant strains (11%) no other antibiotic resistance bacterial strains were detected. However, multiple drug resistance in bacterial isolates from the other sites of Pearl rivers was observed which is possibly due to sewage discharge and input from other anthropogenic sources along the rivers. Four tetracycline resistance genes tet A, tet B, tet C and tet D were detected in the isolates from the rivers. The genes tet A and tet B were widely detected with the detection frequencies of 43% and 40% respectively. Ciprofloxacin and levofloxacin resistant enteric bacteria were also isolated from the pig and duck manures which suggest a wider distribution of human specific drugs in the environment. This investigation provided a baseline data on antibiotic resistance profiles and tetracycline resistance genes in the Pearl rivers delta. - High rates of antibiotic resistance in Enterobacteriaceae from river water are attributed to wastewater contamination.

  10. The implementation of an aquatic toxicity index as a water quality monitoring tool in the Olifants River (Kruger National Park

    Directory of Open Access Journals (Sweden)

    V. Wepener

    1999-01-01

    Full Text Available Large sets of water quality data can leave water quality managers and decision-makers totally overwhelmed. In order to convey the interpretation of the data in a simplified and understandable manner, the water quality results from bi-monthly surveys undertaken at seven different sampling sites in the Letaba, Olifants, and Selati rivers over a two year period (February 1990 to April 1992 were reduced to index values, using a water quality index. The water quality index (Aquatic Toxicity Index or ATI revealed spatial and temporal trends. The higher index values, recorded for the sampling sites towards the eastern part of the Kruger National Park (KNP, revealed that the water quality was better than the quality measured in the Olifants River on the western bound-ary. The lowest index values were calculated for the Selati River, with index values consistently below 50. Index values indicate that the water quality in the Selati River was unsuitable for supporting normal physiological processes in fish. The water quality of the Selati River had an immediate impact on the water quality of the Olifants River directly below the confluence. Lower index values recorded at sites further downstream was also attributed to the influence of the Selati River since there are no known point sources of contaminants within the boundaries of the KNP. The index scores also elucidated temporal trends with lower scores evident during winter months. This was due to reduced flow in the Olifants River and a greater contribution of contaminated water from the Selati River. Index values increased following the first seasonal rains due to a dilution effect. Very low index values were recorded at certain sites during flood periods due to increased turbidity, reduced oxygen, and increased metal concentrations.

  11. Low-flow frequency and flow duration of selected South Carolina streams in the Pee Dee River basin through March 2007

    Science.gov (United States)

    Feaster, Toby D.; Guimaraes, Wladmir B.

    2009-01-01

    Part of the mission of the South Carolina Department of Health and Environmental Control and the South Carolina Department of Natural Resources is to protect and preserve South Carolina's water resources. Doing so requires an ongoing understanding of streamflow characteristics of the rivers and streams in South Carolina. A particular need is information concerning the low-flow characteristics of streams; this information is especially important for effectively managing the State's water resources during critical flow periods such as the severe drought that occurred between 1998 and 2002 and the most recent drought that occurred between 2006 and 2009. In 2008, the U.S. Geological Survey, in cooperation with the South Carolina Department of Health and Environmental Control, initiated a study to update low-flow statistics at continuous-record streamgaging stations operated by the U.S. Geological Survey in South Carolina. Under this agreement, the low-flow characteristics at continuous-record streamgaging stations will be updated in a systematic manner during the monitoring and assessment of the eight major basins in South Carolina as defined and grouped according to the South Carolina Department of Health and Environmental Control's Watershed Water Quality Management Strategy. Depending on the length of record available at the continuous-record streamgaging stations, low-flow frequency characteristics are estimated for annual minimum 1-, 3-, 7-, 14-, 30-, 60-, and 90-day average flows with recurrence intervals of 2, 5, 10, 20, 30, and 50 years. Low-flow statistics are presented for 18 streamgaging stations in the Pee Dee River basin. In addition, daily flow durations for the 5-, 10-, 25-, 50-, 75-, 90-, and 95-percent probability of exceedance also are presented for the stations. The low-flow characteristics were computed from records available through March 31, 2007. The last systematic update of low-flow characteristics in South Carolina occurred more than 20 years

  12. Characterization of water quality and simulation of temperature, nutrients, biochemical oxygen demand, and dissolved oxygen in the Wateree River, South Carolina, 1996-98

    Science.gov (United States)

    Feaster, Toby D.; Conrads, Paul A.

    2000-01-01

    In May 1996, the U.S. Geological Survey entered into a cooperative agreement with the Kershaw County Water and Sewer Authority to characterize and simulate the water quality in the Wateree River, South Carolina. Longitudinal profiling of dissolved-oxygen concentrations during the spring and summer of 1996 revealed dissolved-oxygen minimums occurring upstream from the point-source discharges. The mean dissolved-oxygen decrease upstream from the effluent discharges was 2.0 milligrams per liter, and the decrease downstream from the effluent discharges was 0.2 milligram per liter. Several theories were investigated to obtain an improved understanding of the dissolved-oxygen dynamics in the upper Wateree River. Data suggest that the dissolved-oxygen concentration decrease is associated with elevated levels of oxygen-consuming nutrients and metals that are flowing into the Wateree River from Lake Wateree. Analysis of long-term streamflow and water-quality data collected at two U.S. Geological Survey gaging stations suggests that no strong correlation exists between streamflow and dissolved-oxygen concentrations in the Wateree River. However, a strong negative correlation does exist between dissolved-oxygen concentrations and water temperature. Analysis of data from six South Carolina Department of Health and Environmental Control monitoring stations for 1980.95 revealed decreasing trends in ammonia nitrogen at all stations where data were available and decreasing trends in 5-day biochemical oxygen demand at three river stations. The influence of various hydrologic and point-source loading conditions on dissolved-oxygen concentrations in the Wateree River were determined by using results from water-quality simulations by the Branched Lagrangian Transport Model. The effects of five tributaries and four point-source discharges were included in the model. Data collected during two synoptic water-quality samplings on June 23.25 and August 11.13, 1997, were used to calibrate

  13. Scaling up watershed model parameters: flow and load simulations of the Edisto River Basin, South Carolina, 2007-09

    Science.gov (United States)

    Feaster, Toby D.; Benedict, Stephen T.; Clark, Jimmy M.; Bradley, Paul M.; Conrads, Paul A.

    2014-01-01

    As part of an ongoing effort by the U.S. Geological Survey to expand the understanding of relations among hydrologic, geochemical, and ecological processes that affect fish-tissue mercury concentrations within the Edisto River Basin, analyses and simulations of the hydrology of the Edisto River Basin were made using the topography-based hydrological model (TOPMODEL). A primary focus of the investigation was to assess the potential for scaling up a previous application of TOPMODEL for the McTier Creek watershed, which is a small headwater catchment to the Edisto River Basin. Scaling up was done in a step-wise manner, beginning with applying the calibration parameters, meteorological data, and topographic-wetness-index data from the McTier Creek TOPMODEL to the Edisto River TOPMODEL. Additional changes were made for subsequent simulations, culminating in the best simulation, which included meteorological and topographic wetness index data from the Edisto River Basin and updated calibration parameters for some of the TOPMODEL calibration parameters. The scaling-up process resulted in nine simulations being made. Simulation 7 best matched the streamflows at station 02175000, Edisto River near Givhans, SC, which was the downstream limit for the TOPMODEL setup, and was obtained by adjusting the scaling factor, including streamflow routing, and using NEXRAD precipitation data for the Edisto River Basin. The Nash-Sutcliffe coefficient of model-fit efficiency and Pearson’s correlation coefficient for simulation 7 were 0.78 and 0.89, respectively. Comparison of goodness-of-fit statistics between measured and simulated daily mean streamflow for the McTier Creek and Edisto River models showed that with calibration, the Edisto River TOPMODEL produced slightly better results than the McTier Creek model, despite the substantial difference in the drainage-area size at the outlet locations for the two models (30.7 and 2,725 square miles, respectively). Along with the TOPMODEL

  14. Wildlife and Wildlife Habitat Loss Assessment at Cougar Dam and Reservoir Project, South Fork McKenzie River, Oregon; 1985 Final Report.

    Energy Technology Data Exchange (ETDEWEB)

    Noyes, J.H.

    1985-09-01

    A habitat based assessment was conducted of the US Army Corps of Engineers' Cougar Dam and Reservoir Project on the South Fork McKenzie River, Oregon, to determine losses or gains resulting from the development and operation of the hydroelectric related components of the project. Preconstruction, postconstruction, and recent vegetation cover types of the project site were mapped based on aerial photographs from 1953, 1965, and 1979, respectively. Vegetation cover types were identified within the affected area and acreages of each type at each period were determined. Fifteen wildlife target species were selected to represent a cross-section of species groups affected by the project. An interagency team evaluated the suitability of the habitat to support the target species at each time period. An evaluation procedure which accounted for both the quantity and quality of habitat was used to aid in assessing impacts resulting from the project. The Cougar Project extensively altered or affected 3096 acres of land and river in the McKenzie River drainage. Impacts to wildlife centered around the loss of 1587 acres of old-growth conifer forest and 195 acres of riparian hardwoods. Impacts resulting from the Cougar Project included the loss of winter range for Roosevelt elk, and the loss of year-round habitat for black-tailed deer, black bear, cougar, river otter, beaver, spotted owl, and other nongame species. Bald eagle and osprey were benefited by an increase in foraging habitat. The potential of the effected area to support wildlife was greatly altered as a result of the Cougar Project. Loses or grains in the potential of the habitat to support wildlife will exist over the life of the project.

  15. Surficial and vertical distribution of heavy metals in different estuary wetlands in the Pearl river, South China

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Honggang; Cui, Baoshan [State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Beijing Normal University, Beijing (China); Zhang, Kejiang [Xinjiang Research Center of Water and Wastewater Treatment, Xinjiang Deland Co., LTD., Urumqi (China)

    2012-10-15

    A total of 87 soil profiles sampled from five types of wetlands in the Pearl River estuary were analyzed to investigate the surficial and vertical distributions of heavy metals (Cd, Cr, Cu, Ni, Pb, and Zn). The results show that wetlands directly connected with rivers (e.g., riparian wetlands, estuarine wetlands, and mangrove wetlands) has much higher metal concentrations than those indirectly connected with rivers (e.g., pond wetlands and reclaimed wetlands). The river water is the major pollution source for all investigated heavy metals. The vertical distribution of heavy metals can be classified into three patterns: (i) linear distribution pattern. The concentration of heavy metals gradually decreases with an increase in soil depth (for riparian and estuarine wetlands); (ii) irregular and stable pattern (for pond and reclaimed wetlands); and (iii) middle enrichment pattern (for mangrove wetlands). In addition to river-borne inputs, a variety of vegetation composition, hydraulic conditions, and human activities also contribute to the variation in distribution of heavy metals in different wetlands. Soil properties (e.g., particle size, pH, salinity, and SOM) also affect the distribution of trace metals in each soil layer. The major pollution source of heavy metals is industrial wastewater. Other sources include agriculture and domestic premises, and atmospheric deposition. This study provides a sound basis for the risk assessment of heavy metals in the studied wetlands and for wetland conservation in general. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. Freshwater discharge into the Caribbean Sea from the rivers of Northwestern South America (Colombia): Magnitude, variability and recent changes

    Science.gov (United States)

    Restrepo, Juan Camilo; Ortíz, Juan Carlos; Pierini, Jorge; Schrottke, Kerstin; Maza, Mauro; Otero, Luís; Aguirre, Julián

    2014-02-01

    The monthly averaged freshwater discharge data from ten rivers in northern Colombia (Caribbean alluvial plain) draining into the Caribbean Sea were analysed to quantify the magnitudes, to estimate long-term trends, and to evaluate the variability of discharge patterns. These rivers deliver ∼340.9 km3 yr-1 of freshwater to the Caribbean Sea. The largest freshwater supply is provided by the Magdalena River, with a mean discharge of 205.1 km3 yr-1 at Calamar, which is 26% of the total fluvial discharge into this basin. From 2000 to 2010, the annual streamflow of these rivers increased as high as 65%, and upward trends in statistical significance were found for the Mulatos, Canal del Dique, Magdalena, and Fundación Rivers. The concurrence of major oscillation processes and the maximum power of the 3-7 year band fluctuation defined a period of intense hydrological activity from approximately 1998-2002. The wavelet spectrum highlighted a change in the variability patterns of fluvial systems between 2000 and 2010 characterised by a shift towards a quasi-decadal process (8-12 years) domain. The Intertropical Convergence Zone (ITCZ), El Niño - Southern Oscillation (ENSO) events, and quasi-decadal climate processes are the main factors controlling the fluvial discharge variability of these fluvial systems.

  17. Controls on dryland mountain landscape development along the NW Saharan desert margin: Insights from Quaternary river terrace sequences (Dadès River, south-central High Atlas, Morocco)

    DEFF Research Database (Denmark)

    Stokes, M.; Mather, A.E.; Belfoul, M.

    2017-01-01

    between 50 and 140 m. The rock strength, stratigraphy and structure of the mountain belt influences terrace distribution. Terraces are absent in river gorges of structurally thickened limestone; whilst well-developed, laterally continuous terraces (T1-T4) form along wide valleys occupying syncline...... sands and colluvium. This sequence with some OSL/IRSL age control, suggests terrace formation over a 100 ka climate cycle with valley floor aggradation during full glacials and incision during glacial-interglacial transitions. This integrates with other archives (e.g. lakes, glaciers, dunes), appearing...... typical of landscape development along the NW Saharan margin south of the High Atlas, and similar to patterns in the western-southern Mediterranean. The 100 ka climate cycle relationship suggests that the terrace sequence documents Late-Middle Pleistocene landscape development. Consistent altitudinal...

  18. Long-term meteorological and hydrological dryness and wetness conditions in the Zhujiang River Basin, South China

    Directory of Open Access Journals (Sweden)

    T. Fischer

    2012-09-01

    Full Text Available Floods and droughts are frequently causing large economic losses in China. These conditions vary in space, time, and magnitude. In this study, long-term meteorological and hydrological dryness and wetness conditions are analyzed for the Xijiang River Basin which is the largest tributary of the Zhujiang (Pearl River. A very similar inter-annual course of precipitation and discharge can be observed. The standardized precipitation index (SPI is used to show dryness and wetness pattern in the six sub-basins of the Xijiang River. The SPI-24 correlates high with the standardized discharge index (SDI-24 for Gaoyao hydrological station at the mouth of Xijiang River. Distinct long-term dryness and wetness sequences are found in the time series for the SPI-24 and SDI-24. The principal component analysis reveals many spatial interdependencies in dryness and wetness conditions for the sub-basins and explains some spatio-temporal disparities. Moderate dryness conditions have a larger spatial impact than moderate wetness conditions in the sub-basins. The loading pattern of the first principal component shows that the correlation with the entire Xijiang River Basin is highest in the eastern and lowest in the western sub-basins. Further spatial dipole conditions explain the spatio-temporal heterogeneity of dryness and wetness conditions. Accordingly, the precipitation in the eastern sub-basins contributes more to the hydrological wetness conditions than in the western sub-basins, which mainly contribute to dryness patterns.

    The spectral analysis for the SPI-24 (entire Xijiang River Basin and SDI-24 shows similar peaks for periods of 11–14.7 yr, 2.8 yr, 3.4–3.7 yr, and 6.3–7.3 yr. The same periods can be found for the SPI-24 of Xijiang River's six sub-basins with some variability in the magnitude. The wavelet analysis shows that the most significant periods are stable over time since the 1980s. The extrapolations of the reconstructed time series

  19. High-resolution sedimentary records of heavy metals in Guangzhou section of the Pearl River, South China

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The sedimentary feature and variation of heavy metals in ca. 100 years, especially in the last three decades, in the riverbed of Guangzhou section of the Pearl River were revealed by the sedimentary heavy metal fluxes and total organic carbon (TOC) in a 210Pb-dated sedimentary core. It is suggested that the historical changes of heavy metal contamination can be recorded by pollutant sedimentary fluxes rather than by their concentrations. The heavy metal contamination in the river section was divided into 6 sedimentary historical stages of 3 groups, which correspond to the economic development and regional urbanization process.

  20. 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 U.S....

  1. 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 U.S....

  2. 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...

  3. 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 U.S....

  4. 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 U.S....

  5. 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 U.S....

  6. Sprague River Oregon Water 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 U.S....

  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 U.S....

  8. 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...

  9. 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 U.S....

  10. Sprague River Oregon Centerline 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 U.S....

  11. Sprague River Oregon Centerline 2005

    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 U.S....

  12. 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 U.S....

  13. Persistent halogenated compounds in fish from rivers in the Pearl River Delta, South China: Geographical pattern and implications for anthropogenic effects on the environment.

    Science.gov (United States)

    Sun, Runxia; Luo, Xiaojun; Tang, Bin; Li, Zongrui; Wang, Tao; Tao, Lin; Mai, Bixian

    2016-04-01

    Three fish species, mud carp (Cirrhinus molitorella), tilapia (Tilapia nilotica), and plecostomus (Hypostomus plecostomus), from rivers in the Pearl River Delta (PRD) were analyzed for dichlorodiphenyltrichloroethane and its metabolites (DDTs), hexachlorocyclohexanes (HCHs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), decabromodiphenyl ethane (DBDPE), and Dechlorane Plus (DP). The concentrations of DDTs, HCHs, PCBs, PBDEs, DBDPE, and DP ranged from 380-57,000, 5.5-100, 30-4200, 6.9-690, 0.29-460, and 0.09-20ng/g lipid weight, respectively. Congener profiles or chemical compositions of PBDEs, DPs, DDTs, and HCHs in plecostomus differed significantly from those in the other two fish species, which can be ascribed to species-specific metabolism. DDTs derived from historical residue and land erosion remained the predominant pollutants in the PRD, while industrial and urban activities resulted in elevated levels of PCBs and PBDEs in the metropolitan area. E-waste recycling activities have greatly impacted on the adjacent aquatic environment, and the potential point source for DBDPE was also revealed.

  14. Inventory of Long-Term Braiding Activity at a Regional Scale as a Tool for Detecting Alterations to a Rivers' Hydromorphological State: A Case Study for Romania's South-Eastern Subcarpathians

    Science.gov (United States)

    Ioana-Toroimac, Gabriela

    2016-07-01

    The inventory of long-term braiding activity is a useful tool for detecting alterations in a rivers' hydromorphological state and for a river's management in the context of the Water Framework Directive on integrated river basin management for Europe. Our study focuses on braided sectors of rivers in South-Eastern Subcarpathians (Romania). The inventory evaluates types of alterations based on the spatial analysis of fluvial morphology indicators (i.e., length of the river sector forming a braided pattern; width of the braided active channel), and vegetation cover (i.e., length of banks covered by forest and shrubs; area of in-stream patches of shrubs) accumulated over the last century. Furthermore, we performed a regional scale hierarchical cluster analysis to estimate the degree of alteration when compared to an historical baseline. In South-Eastern Subcarpathians, the studied rivers experienced a decrease of braiding activity revealed by the shortening and narrowing of their braided sectors, expansion of riparian forests, and the diminishment of vegetated islands' areas. We separated three types of river clusters, corresponding to low (cluster 1), moderate (cluster 2), and high (cluster 3) degree of alteration. Moreover, the clusters demonstrate the evolutionary path of the braided pattern alterations until the functioning of another channel pattern. The inventory is relevant for differing types and levels of alterations. Additionally, this tool may serve as a first step toward the restoration of altered sectors by identifying rivers in cluster 1 as potential candidates of present-day reference sites for altered rivers with similar natural conditions as in cluster 3.

  15. Characterization and risk assessment of polychlorinated biphenyls in soils and rice tissues in a suburban paddy field of the Pearl River Delta, South China.

    Science.gov (United States)

    Li, Qilu; Wang, Yan; Luo, Chunling; Li, Jun; Zhang, Gan

    2015-08-01

    We investigated the concentration and composition of polychlorinated biphenyls (PCBs) in paddy soils and rice tissues and the associated potential health risks in the urban agricultural areas of the Pearl River Delta (PRD), South China. The results indicated that highly chlorinated PCBs were more prominent in soil when the concentrations of low-molecular-weight PCBs were relatively high in rice plants. There was a trend of decreasing PCB concentrations with soil depth and a significant correlation between PCBs and the total organic carbon or total nitrogen concentration in section soils. The PCB concentrations followed the order of root > leaf > stem > grain. Although the dioxin toxicity equivalency values and estimated daily intake levels (based direct and indirect consumption) were lower than in other seriously contaminated regions, there is still a need to monitor PCB pollution in urban agriculture because of the PCB emissions from capacitor storage following the rapid urbanization experienced in the PRD.

  16. Effects of landscape heterogeneity on the elevated trace metal concentrations in agricultural soils at multiple scales in the Pearl River Delta, South China.

    Science.gov (United States)

    Li, Cheng; Li, Fangbai; Wu, Zhifeng; Cheng, Jiong

    2015-11-01

    Based on multiple geo-accumulation indices and correlation and partial redundancy analyses, we examined the spatial patterns of agricultural soil contaminations for As, Pb, Cd, Cr, and Ni in the Pearl River Delta, South China and their relations with landscape heterogeneity at small, medium and large spatial scales. We found that the concentrations of trace elements were slightly elevated, and most trace metals had a geogenic origin. Landscape variables explained 21-53% of the variation of elevated trace metal concentrations with an increasing explanatory power from the small to the large scale. The three variable groups representing parent materials, distance density characteristics and land use had different contributions to the elevated trace metals among scales. Both the distance density variables and land use pattern had a stronger influences on trace metal concentrations at a small scale than at a larger scale, while the parent materials was important at all the scales.

  17. Gardening arts of private gardens in south of the Yangtze River in Qing dynasty%清代江南私家园林的造园艺术

    Institute of Scientific and Technical Information of China (English)

    石岩

    2011-01-01

    以拙政园等著名园林为例,对其造园艺术从山水构架、光影表现等方面进行了论述,总结出以小见大、以水为魂、山石植物协调配置等特点,以期指导相关设计人员深入了解清代江南私家园林。%With Zhuozheng park and other famous parks as the example,it discusses the gardening arts from aspects of scenery structure and sunlight and shade embodiment,summarizes the features,such as seeing big things through small ones,takes water as the soul,coordination of mountain stone and plants,with a view to guide relevant designers to have deep understanding for south of the Yangtze River private gardens in Qing dynasty.

  18. Uranium-bearing lignite and its relation to the White River and Arikaree formations in northwestern South Dakota and adjacent states

    Science.gov (United States)

    Denson, N.M.; Bachman, G.O.; Zeller, H.D.

    1954-01-01

    In northwestern South Dakota and adjacent areas uranium-bearing lignite beds occur at many horizons in the Hell Creek formation of late Cretaceous age and the overlying Ludlow, Tongue River, and Sentinel Butte members of the Fort Union formation of Paleocene age. Uranium analyses of 275 surface and auger samples and about 1,000 core samples show that many of the lignite beds contain 0. 005 to 0. 02 percent uranium with concentrations of 0. 05 to 0.10 percent uranium in the lignite ash. Analytical data indicate that the region contains an aggregate of at least 47,500, 000 tons of lignite with an average grade of slightly more than .0. 008 percent containing 3, 900 tons of uranium. Almost a fifth of the estimated reserves are adapted to strip mining and are in beds averaging about 4 feet in thickness. Uranium concentrations of this magnitude in lignite indicate that these deposits upon the development of proper utilization techniques and processes may be an important future source of uranium. Recent discoveries of ore-grade deposits of autunite-bearing lignite and secondary uranium minerals in carbonaceous sandstone at Cave Hills and Slim Buttes indicate that northwestern South Dakota and adjacent areas may containimportant reserves of uranium-ore. The stratigraphic units containing the uraniferous lignite beds have a combined thickness of about 1, 500 feet and are unconformably overlapped by 300 feet or more of tuffaceous sandstone and bentonitic claystone of the White River and Arikaree formations of Oligocene and Miocene age. The stratigraphically highest lignite beds in the local sequence have the greatest concentration of uranium,, and the uranium content is greatest at the top of thick lignite beds, diminishing progressively downward to a vanishing point in their lower parts. Variations in permeability of the rock overlying the mineralized lignite beds seem to be reflected in the intensity of uranium mineralization. Most of the known uranium-bearing lignite

  19. Zinc complexing ligands in rivers in pristine peatland areas in Borneo, and rivers with agricultural and industrial anthropogenic influence in Tropical South East Asia: Elucidating the connection to oceanic regional and global distributions of Zinc ligands and bioavailable Zinc

    Science.gov (United States)

    Carrasco, G. G.; Chen, M.

    2016-02-01

    Organic complexing ligands dominate the chemical speciation of Zn in seawater globally, affecting its bioavailability and regulating its micronutrient role. We have shown that intermediate water masses in the West Pacific indicate a connection between point sources related to marginal seas, riverine matter, benthic fluxes, and continental shelves, with ligand concentrations and binding strengths evolving along water mass trajectories. Here we will present results from recent studies in tropical South East Asia that explore rivers in pristine peatland areas in Borneo, and rivers near and around agricultural and industrial anthropogenic influence in Borneo, Singapore and Malaysia, with the aim of elucidating the importance of relatively fresh natural and agricultural land-based plant material and industrial anthropogenic material in the organic matter mix that the ligands are a part of. These results track the ligand concentration and binding strength of different sources of Zn complexing ligands obtained using ASV and modern comprehensive mathematical methods We will compare records of humic substances from coral cores near the mouth of these rivers, with the goal of ascertaining a possible link of humic substance concentrations and metal complexing ligands in the region. We will compare the results from these large sources of organic matter with the ligands observed in continental shelves, where the organic matter has suffered biochemical processes, with ligands observed in the West Pacific, after decades of bacterial respiration while travelling along water masses. We aim to compare these ligand in order to assess the relevance of these sources of complexing ligands to regulate regional and global distribution of Zn ligands and its bioavailable concentrations.

  20. Impact of seasonal variation on Escherichia coli concentrations in the riverbed sediments in the Apies River, South Africa

    CSIR Research Space (South Africa)

    Abia, ALK

    2015-12-01

    Full Text Available on the Apies River between May and August 2013 (dry season) and between January and February 2014 (wet season). E. coli was enumerated using the Colilert®-18 Quanti-Tray® 2000 system. All sites tested positive for E. coli. Wastewater treatment work effluents...

  1. Potentiometric-surface altitude of the confined aquifer, Wood River Valley aquifer system, south-central Idaho, October 2012.

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Water levels in 93 wells completed in the Wood River Valley aquifer system were measured during October 22–24, 2012; these wells are part of a network established...

  2. Water-table altitude of the unconfined aquifer, Wood River Valley aquifer system, south-central Idaho, October 2012.

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Water levels in 93 wells completed in the Wood River Valley aquifer system were measured during October 22–24, 2012; these wells are part of a network established...

  3. Assessing Hydrologic Impacts of Future Land Cover Change Scenarios in the South Platte River Basin (CO, WY, & NE)

    Science.gov (United States)

    Long‐term land‐use and land cover change and their associated impacts pose critical challenges to sustaining vital hydrological ecosystem services for future generations. In this study, a methodology was developed on the San Pedro River Basin to characterize hydrologi...

  4. Subsurface stratigraphy and structure of A/M area at the Savannah River Site, Aiken County, South Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Fallaw, W.C.; Sims, W.R.; Haselow, J.S.

    1991-08-01

    This report is a study of the stratigraphy and structure of the A/M Area Hazardous Waste Management Facility Post-Closure Care Permit process on the Savannah River Site. The data from the lithologic and geophysical logs of 93 wells is the basis of this analysis.

  5. Subsurface stratigraphy and structure of A/M area at the Savannah River Site, Aiken County, South Carolina. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Fallaw, W.C.; Sims, W.R.; Haselow, J.S.

    1991-08-01

    This report is a study of the stratigraphy and structure of the A/M Area Hazardous Waste Management Facility Post-Closure Care Permit process on the Savannah River Site. The data from the lithologic and geophysical logs of 93 wells is the basis of this analysis.

  6. Assessing Hydrologic Impacts of Future Land Cover Change Scenarios in the South Platte River Basin (CO, WY, & NE)

    Science.gov (United States)

    Long‐term land‐use and land cover change and their associated impacts pose critical challenges to sustaining vital hydrological ecosystem services for future generations. In this study, a methodology was developed on the San Pedro River Basin to characterize hydrologi...

  7. 78 FR 59231 - Regulated Navigation Area-Tappan Zee Bridge Construction Project, Hudson River; South Nyack and...

    Science.gov (United States)

    2013-09-26

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA11 Regulated Navigation Area--Tappan Zee Bridge... area (RNA) on the navigable waters of the Hudson River surrounding the Tappan Zee Bridge. This... situation created by the construction of the Tappan Zee Bridge. The Coast Guard has discussed this...

  8. Assessment of some heavy metals in the tissues (gills, liver and muscle) of Clarias gariepinus from Calabar River, Cross River State, South-eastern Nigeria

    Institute of Scientific and Technical Information of China (English)

    Akaninyene Paul Joseph; Victor Oscar Eyo; Andem BasseyAndem; Joseph Udo Idung

    2016-01-01

    Objective: To assess the pollution status of Calabar River in relation to the levels of heavy metal in the tissue of the African catfish [Clarias gariepinus (C. gariepinus)]. Methods: A total of 45 samples of C. gariepinus were purchased from fishermen on landing at Nsidung beach along Calabar River within three months (15 samples monthly) from June to August, 2014. The samples were then put into a cold box containing ice blocks immediately after buying from the fishermen. The fish samples were transported immediately to the Chemistry Laboratory, University of Calabar for digestion and heavy metal analysis. Portions of the muscle, gills and liver were removed from the fresh samples and oven dried at temperature of 120 °C to constant weight and digested using standard methods. The digested tissue portions were analyzed for lead, iron, manganese, cobalt, chromium and cadmium concentrations using atomic absorption spectrophotometer. Results: Mercury was not detected at all in the muscle, liver and gills of C. gariepinus. The mean ± SD of metals in liver of C. gariepinus were: (0.080 ± 0.014), (0.110 ± 0.014), (6.480 ± 1.279) and (0.295 ± 0.021) mg/kg for Cd, Cr, Fe and Mn, respectively. In the gills, heavy metals values were: (0.065 ± 0.021), (0.115 ± 0.035), (5.843 ± 0.558), and (0.345 ± 0.007) mg/kg for Cd, Cr, Fe and Mn, respectively. In the muscles, heavy metals values were (0.045 ± 0.021), (0.115 ± 0.353), (5.150 ± 1.075), and (0.187 ± 0.045) mg/kg for Cd, Cr, Fe and Mn, respectively. The general trend of metals accumulation in tissues of C. gariepinus showed a decreasing trend of Fe > Mn > Cr > Cd. Also, the metal accumulation in the three tissues showed a decreasing trend of liver > gills > muscle. Conclusions: The metal concentrations in the muscle, gills and liver of C. gariepinus were all below the World Health Organization acceptable range, and as such fishery resources from Calabar River are safe for consumption.

  9. Assessment of some heavy metals in the tissues (gills, liver and muscle of Clarias gariepinus from Calabar River, Cross River State, South-eastern Nigeria

    Directory of Open Access Journals (Sweden)

    Akaninyene Paul Joseph

    2016-06-01

    Full Text Available Objective: To assess the pollution status of Calabar River in relation to the levels of heavy metal in the tissue of the African catfish [Clarias gariepinus (C. gariepinus]. Methods: A total of 45 samples of C. gariepinus were purchased from fishermen on landing at Nsidung beach along Calabar River within three months (15 samples monthly from June to August, 2014. The samples were then put into a cold box containing ice blocks immediately after buying from the fishermen. The fish samples were transported immediately to the Chemistry Laboratory, University of Calabar for digestion and heavy metal analysis. Portions of the muscle, gills and liver were removed from the fresh samples and oven dried at temperature of 120 °C to constant weight and digested using standard methods. The digested tissue portions were analyzed for lead, iron, manganese, cobalt, chromium and cadmium concentrations using atomic absorption spectrophotometer. Results: Mercury was not detected at all in the muscle, liver and gills of C. gariepinus. The mean ± SD of metals in liver of C. gariepinus were: (0.080 ± 0.014, (0.110 ± 0.014, (6.480 ± 1.279 and (0.295 ± 0.021 mg/kg for Cd, Cr, Fe and Mn, respectively. In the gills, heavy metals values were: (0.065 ± 0.021, (0.115 ± 0.035, (5.843 ± 0.558, and (0.345 ± 0.007 mg/kg for Cd, Cr, Fe and Mn, respectively. In the muscles, heavy metals values were (0.045 ± 0.021, (0.115 ± 0.353, (5.150 ± 1.075, and (0.187 ± 0.045 mg/kg for Cd, Cr, Fe and Mn, respectively. The general trend of metals accumulation in tissues of C. gariepinus showed a decreasing trend of Fe > Mn > Cr > Cd. Also, the metal accumulation in the three tissues showed a decreasing trend of liver > gills > muscle. Conclusions: The metal concentrations in the muscle, gills and liver of C. gariepinus were all below the World Health Organization acceptable range, and as such fishery resources from Calabar River are safe for consumption.

  10. 华南地区外来鱼类革胡子鲶的建群状况%The study on population establishment of alien Clarias gariepinus in main rivers of South China

    Institute of Scientific and Technical Information of China (English)

    朱赟杰; 顾党恩; 韦慧; 牟希东; 罗渡; 徐猛; 罗建仁; 胡隐昌

    2016-01-01

    为摸清革胡子鲶( Clarias gariepinus)在我国华南地区的入侵现状及种群现状,对华南地区珠江(西江、北江、东江)、鉴江、潭江和南渡江等主要河流的多个样点进行调查,并对各种群年龄结构、性比和性腺发育期等生物学特征进行研究。结果显示:华南地区各主要河流均有革胡子鲶分布,各群体均存在二龄以上个体和性成熟个体,样本性比为(♀∶♂)=1∶1.18,在调查中同时发现大量仔、幼鱼,表明革胡子鲶在华南地区各自然水域能够实现正常越冬和自然繁殖,已建立自然种群。%To study the status quo of invasive populations of Clarias gariepinus in South China, we surveyed C.gariepinus in the main rivers of South China, including the Pearl River tributary, Jianjiang River and Tanjiang River, and collected data on the age structure, gonad development.The results showed that C.gariepinus distributed in all the major rivers of South China, all populations had individuals at the age of more than two years and sexual maturity individuals.Sex ratio(♀∶♂)was 1∶1.18.It suggested that it can overwinter and reproduction in natural waters, and had established natural popu-lations in the main rivers of South China.

  11. How significant is submarine groundwater discharge and its associated dissolved inorganic carbon in a river-dominated shelf system-the northern South China Sea?

    Directory of Open Access Journals (Sweden)

    Q. Liu

    2011-12-01

    Full Text Available In order to assess the role of submarine groundwater discharge (SGD and its impact on the carbonate system on the northern South China Sea (NSCS shelf, we measured seawater concentrations of four radium isotopes 223,224,226,228Ra along with carbon dioxide parameters in June–July, 2008. Complementary groundwater sampling was conducted in coastal areas in December 2008 and October 2010 to constrain the groundwater end-members. The distribution of Ra isotopes in the NSCS was largely controlled by the Pearl River plume and coastal upwelling. Long-lived Ra isotopes (228Ra and 226Ra were enriched in the river plume but low in the offshore surface water and subsurface water/upwelling zone. In contrast, short-lived Ra isotopes (224Ra and 223Ra were elevated in the subsurface water/upwelling zone as well as the river plume but depleted in the offshore surface water. In order to quantify SGD, we adopted two independent mathematical approaches. Using a three end-member mixing model with total alkalinity (TAlk and Ra isotopes, we derived a SGD flux into the NSCS shelf of 2.3–3.7 ×108 m3 d−1. Our second approach involved a simple mass balance of 228Ra and 226Ra and resulted in a first order but consistent SGD rate estimate of 2.8–4.5 × 108 m3 d−1. These fluxes were equivalent to 13–25 % of the Pearl River discharge, but the source of the SGD is mostly recirculated seawater. Despite the relatively small SGD volume flow compared to the river, the associated material fluxes were substantial given the elevated concentrations of dissolved inorganic solutes. In this case, dissolved inorganic carbon (DIC flux through SGD was 266–520 × 109 mol yr−1, which was ~44–73 % of the riverine DIC export flux. Given our estimates of the groundwater-derived phosphate flux, SGD may be

  12. Pollution by oestrogenic endocrine disruptors and β-sitosterol in a south-western European river (Mira, Portugal).

    Science.gov (United States)

    Rocha, Maria João; Cruzeiro, Catarina; Reis, Mário; Pardal, Miguel Ângelo; Rocha, Eduardo

    2016-04-01

    The Mira River is a Portuguese water body widely known for its wilderness and is advertised as one of the less polluted European rivers. On this presumption, the levels of endocrine-disrupting compounds (EDCs) in Mira waters were never measured. However, because environmentalists have claimed that the Mira could be moderately polluted, a range of 17 EDCs were measured not only at the estuary but also along the river. The targeted EDCs included natural and pharmaceutical oestrogens (17β-oestradiol, oestrone and 17α-ethynylestradiol), industrial/household pollutants (octylphenols, nonylphenols and their monoethoxylates and diethoxylates and bisphenol A), phytoestrogens (formononetin, biochanin A, daidzein, genistein) and the phytosterol sitosterol (SITO). For this propose, waters from six sampling sites were taken every 2 months, over a 1-year period (2011), and analysed by gas chromatography-mass spectrometry. Unexpectedly high levels of oestrogens and of industrial/household pollutants were measured at all sampling sites, including those located inside natural protected areas. Indeed, the annual average sum of EDCs was ≈57 ng/L for oestrogens and ≈1.3 μg/L for industrial/household chemicals. In contrast, the global average levels of phytoestrogens (≈140 ng/L) and of SITO (≈295 ng/L) were lower than those reported worldwide. The EDC concentrations were normalised for ethynylestradiol equivalents (EE2eq). In view of these, the oestrogenic load of the Mira River attained ≈47 ng/L EE2eq. In addition, phosphates were above legal limits at both spring and summer (>1 mg/L). Overall, data show EDCs at toxicant relevant levels in the Mira and stress the need to monitor rivers that are allegedly less polluted.

  13. Occurrence and distribution of phthalate esters in riverine sediments from the Pearl River Delta region, South China.

    Science.gov (United States)

    Liu, Hong; Cui, Kunyan; Zeng, Feng; Chen, Lixuan; Cheng, Yating; Li, Huiru; Li, Shuocong; Zhou, Xi; Zhu, Fang; Ouyang, Gangfeng; Luan, Tiangang; Zeng, Zunxiang

    2014-06-15

    Sixty-eight sediment samples collected from Dongjiang River, Xijiang River, Beijiang River and Zhujiang River in the Pearl River Delta (PRD) region, Southern China, were analyzed for 16 phthalate esters (PAEs). PAEs were detected in all riverine sediments analyzed, which indicate that PAEs are ubiquitous environmental contaminants. The Σ16PAEs concentrations in riverine sediments in the PRD region ranged from 0.567 to 47.3 μg g(-1) dry weight (dw), with the mean and median concentrations of 5.34 μg g(-1) dw and 2.15 μg g(-1) dw, respectively. Elevated PAEs concentrations in riverine sediments in the PRD region were found in the highly urbanized and industrialized areas. Of the 16 PAEs, diisobutyl phthalate (DiBP), di-n-butyl phthalate (DnBP) and di(2-ethylhexyl) phthalate (DEHP) dominated the PAEs, with the mean and median concentrations of 1.12 μg g(-1)dw, 0.420 μg g(-1) dw and 3.72 μg g(-1) dw, and 0.429 μg g(-1) dw, 0.152 μg g(-1) dw and 1.55 μg g(-1) dw, respectively, and accounted for 94.2-99.7% of the Σ16PAEs concentrations. Influenced by local sources and the properties of PAEs, a gradient trend of concentrations and a fractionation of composition from more to less industrialized and urbanized areas were discovered. As compared to the results from other studies, the riverine sediments in the PRD region were severely contaminated with PAEs. Information about PAEs contamination status and its effect on the aquatic organisms in the PRD region may deserve further attention.

  14. The February 2000 floods on the Sabie River, South Africa: an examination of their magnitude and frequency

    Directory of Open Access Journals (Sweden)

    G.L. Heritage

    2001-07-01

    Full Text Available The floods that affected much of Southern Africa in February 2000 have been reported as the largest in living memory by many observers. However, the force of the floods damaged the majority of the gauging stations located on the affected rivers, many of which were not constructed to measure flows of such a magnitude. This paper presents an estimation of the peak flood discharge on 6 February 2000 for the bedrock influenced Sabie River in the Kruger National Park, by simulating the hydraulic and geometric characteristics of the peak flow and relating these to the roughness character of the channel. Peak water surface slope data in the form of strandline measurements at channel type breaks along the river were collected for six sites along the Sabie River within the Kruger National Park. Flood conditions within each channel type were considered to approximate to uniform flow. The cross-sections are located between major tributary inputs allowing for approximate sub-catchment flow contributions to be estimated. The results indicate that the flow peaked at around 3000 mVs at the Kruger Gate entrance to the Kruger National Park, increasing to approximately 5500mVs at Skukuza and 7000 mVs at Lower Sabie close to the Mozambique border following inputs from the Sand River sub-catchment. These estimates compare well with the simulated rainfall runoff total of 4300 mVs at Skukuza, however, precipitation inputs over the lowveld appear to indicate that the discharge only rises to 4950 mmVs at Lower Sabie. A flood flow of this magnitude has never been experienced based on the simulated flow data generated by the ACRU hydrological model calibrated against measured flows therefore suggesting a return period in excess of the 60 years of record.

  15. Water Quality in the Equus Beds Aquifer and the Little Arkansas River Before Implementation of Large-Scale Artificial Recharge, South-Central Kansas, 1995-2005

    Science.gov (United States)

    Ziegler, Andrew C.; Hansen, Cristi V.; Finn, Daniel A.

    2010-01-01

    Artificial recharge of the Equus Beds aquifer using runoff from the Little Arkansas River in south-central Kansas was first proposed in 1956 and was one of many options considered by the city of Wichita to preserve its water supply. Declining aquifer water levels of as much as 50 feet exacerbated concerns about future water availability and enhanced migration of saltwater into the aquifer from past oil and gas activities near Burrton and from the Arkansas River. Because Wichita changed water-management strategies and decreased pumping from the Equus Beds aquifer in 1992, water storage in the aquifer recovered by about 50 percent. This recovery is the result of increased reliance on Cheney Reservoir for Wichita water supply, decreased aquifer pumping, and larger than normal precipitation. Accompanying the water-level recovery, the average water-level gradient in the aquifer decreased from about 12 feet per mile in 1992 to about 8 feet per mile in January 2006. An important component of artificial recharge is the water quality of the receiving aquifer and the water being recharged (source water). Water quality within the Little Arkansas River was defined using data from two real-time surface-water-quality sites and discrete samples. Water quality in the Equus Beds aquifer was defined using sample analyses collected at 38 index sites, each with a well completed in the shallow and deep parts of the Equus Beds aquifer. In addition, data were collected at diversion well sites, recharge sites, background wells, and prototype wells for the aquifer storage and recovery project. Samples were analyzed for major ions, nutrients, trace metals, radionuclides, organic compounds, and bacterial and viral indicators. Water-quality constituents of concern for artificial recharge are those constituents that frequently (more than 5 percent of samples) may exceed Federal [U.S. Environmental Protection Agency (USEPA)] and State drinking-water criteria in water samples from the receiving

  16. Polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides in water columns from the Pearl River and the Macao harbor in the Pearl River Delta in South China.

    Science.gov (United States)

    Luo, Xiaojun; Mai, Bixian; Yang, Qingshu; Fu, Jiamo; Sheng, Guoying; Wang, Zhishi

    2004-06-01

    Polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs) were measured in suspended particles and dissolved phase from the Baiertang water column and the Macao water column samples as collected from the Guangzhou channel of the Pearl River and the Macao harbor, where the sediments were heavily contaminated with organic pollutants. Total OCPs concentration varies from 23.4 to 61.7 ng/l in Baiertang water column and from 25.2 to 67.8 ng/l in Macao column, while total PAHs concentration varies from 987.1 to 2878.5 ng/l in the Baiertang water column and from 944.0 to 6654.6 ng/l in the Macao column. The vertical distribution profiles of pollutants and the partition of pollutants between particles and dissolved phases indicate that the sediments in Baiertang act as an important source of selected pollutants, and the pollutants in water of this region were mainly originated from the release and re-suspension of contaminants residing in the sediments. The sediments in Macao harbor act as a reservoir for organochlorine pesticides, such as DDTs mainly introduced by river inflow from Xijiang and PAHs input by brackish water from the Lingdingyang estuary. Combustion of fossil fuels and petroleum input are the main sources of PAHs in the Macao water column, while combustion of fossil fuels and coal is responsible for the PAHs in the Baiertang water column. The ratios of DDT/(DDD+DDE) for the Macao water column samples demonstrate that such chemicals were input into this region in recent times.

  17. Elemental (C/N ratios) and Isotope (δ13CTOC, δ15NTN) Compositions of Surface Sediments from the Barrier Islands in the Nakdong River Estuary, South Korea

    Science.gov (United States)

    Lee, Jun-Ho; Woo, Han Jun; Jeong, Kap-Sik; Kang, Jeongwon; Choi, Jae Ung; Lee, Dong-Hun

    2017-04-01

    The Nakdong River Estuary (NRE) in South Korea is a typical, artificially-manipulated estuary and blocked by two large dam. The Noksan Dam, built in 1934, blocks the flow of the West Nakdong River, and the NRE Dam was completed between 1983 and 1987 to regulate the flow of the East Nakdong River (called the Eulsuk River locally). For the past half century, several huge industrial complexes have been developed in the reclaimed land near the NRE. In the estuary, the hydraulic circulation has been markedly modified caused by the changes in the river discharge and geomorphic configuration of such as the formation of a series of barrier islands, the two large dams resulting from the artificial control of the natural river flow and upstream intrusion of saltwater by the operation of the two large dams. Consequently, the saltwater wedge that once reached approximately 40 km upstream is now blocked at the dam, considerably reducing the tidal prism. The estuary is typified by barrier-lagoon system with various subenvironments and microtidal with a 1.5 m tidal range. We investigated the elemental (C/N ratios) and isotopic (δ13CTOC, δ15NTN) compositions of organic matters in various composition in the surface sediments in the NRE. In May 2015, 90 surface sediment samples were collected on and around three islands in the NRE. The mean grain size of the barrier island system in the NRE ranged from 1.1 to 8.9 Φ (average 3.9 Φ) in mean grain size, and they were composed of various sediment types, including muddy Sand (S), sandy Mud (sM), and Mud (M). A useful application of the C/N ratios is as a proxy for assessment of organic matter source change, related to the sediment origins terrestrial or marine. The C/N ratios (average, 5.88) imply that the organic matter in the study area was of marine origins, as indicated by the lower ratios between 4 and 10. The isotope composition of sedimentary organic matter (δ13CTOC, δ15NTN) indicated the deposition of algae-derived organic

  18. IMPACTS OF THE SOUTH-TO-NORTH WATER DIVERSION PROJECTS (MIDDLE ROUTE)ON THE WATER ENVIRONMENT OF THE MIDDLE AND LOWER REACHES OF THE HANJIANG RIVER

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The Hanjiang River is the most important tributary ofthe Changjiang River,which has alength of1570km.Theconfluence of the river withthe Yangtze Riveris at Wuhancity.Fromthe Danjiangkoutothe Nianpanshanextendsthemiddle reach of the Hanjiang River,whichis240kmlongand represents a forkriver section,havingtributaries suchas the Bei River,the Nan River,the Tangbai River,andothers.The lower reach extents from Nianpanshan to theestuary,stretching over409km.,This stretchis a curvedriver section,havingtributaries su...

  19. Feeding ecology of the freshwater crab Trichodactylus borellianus (Decapoda: Trichodactylidae in the floodplain of the Paraná River, southern South America

    Directory of Open Access Journals (Sweden)

    Verónica Williner

    2013-09-01

    Full Text Available Freshwater crabs are not commonly considered to be an important group in trophic webs, and this might be due to a lack of knowledge about their trophic roles in aquatic ecosystems. Trichodactylus borellianus is one of the most common and widely distributed freshwater crabs in the floodplains of the southern South American rivers. The main objective of the present study was to examine the trophic role of T. borellianus, in the floodplain of the Paraná River, and its relationships with the freshwater littoral community. The trophic spectrum of this species was characterized for both sexes and individuals of different sizes (adults and juveniles, throughout daily and seasonal cycles. Samples were collected from the aquatic vegetation of three shallow lakes. The diet composition and the feeding activity of T. borellianus were evaluated through the examination of the stomach contents and their degree of emptiness. This crab species consumed several plant and animal items, including amoebas, rotifers, oligochaetes, copepods, cladocerans, and insect larvae. Moreover, this species consumes filamentous and unicellular algae, diatoms, fungi, and macrophytic remains. The predatory habits varied with the season and time of day, and variations in the feeding activity of the juveniles and adults were detected and documented. The diversity of food items eaten by this crab suggests that its trophic role in the community as an omnivore and opportunistic predator provides a connection among several trophic levels from both aquatic and terrestrial communities.

  20. Modeling Glacier Mass Balance and Runoff in the Koxkar River Basin on the South Slope of the Tianshan Mountains, China, from 1959 to 2009

    Directory of Open Access Journals (Sweden)

    Min Xu

    2017-02-01

    Full Text Available Water resources provided by alpine glaciers are an important pillar for people in the arid regions of west China. In this study, the Hydrologiska Byrans Vattenavdelning (HBV light model was applied to simulate glacier mass balance (GMB and runoff in the Koxkar River Basin (KRB on the south slope of Mount Tumur, in the western Tianshan Mountains. Daily temperature and precipitation were calculated by multiple linear regressions and gradient-inverse distance weighting, respectively, based on in-situ observed data by automatic weather stations (AWSs in the Koxkar River Basin (KRB; 2007–2009 and four meteorological stations neighboring the basin (1959–2009. Observed daily air temperature and precipitation were input into HBV model. The runoff data in 2007/2008 and 2008/2009 were used to calibrate and validate the model in 2009/2010 and 2010/2011. Generally, the model simulated runoff very well. The annual glacier mass balance and runoff were calculated by the HBV model and were driven by interpolated meteorological data between 1959 and 2009. The calculated glacier mass balances were reasonable, and were compared with nearby glaciers. The results indicate the decreasing trend of mass balance in the Koxkar Glacier, with an average value of ablation of −370.4 mm·a−1 between 1959 and 2009. The annual runoff showed an increasing trend (5.51 mm·a−1. Further analysis showed that the runoff is more sensitive to temperature than precipitation in KRB.

  1. Suitability of pharmaceuticals and personal care products (PPCPs) and artificial sweeteners (ASs) as wastewater indicators in the Pearl River Delta, South China.

    Science.gov (United States)

    Yang, Yuan-Yuan; Liu, Wang-Rong; Liu, You-Sheng; Zhao, Jian-Liang; Zhang, Qian-Qian; Zhang, Min; Zhang, Jin-Na; Jiang, Yu-Xia; Zhang, Li-Juan; Ying, Guang-Guo

    2017-07-15

    Wastewater indicator is a useful tool for evaluating the wastewater impact on natural water, but there is little information about the suitability of wastewater indicators for different regions. This study aimed to select suitable wastewater indicators in the Pearl River Delta region, south China by screening a range of wastewater related organic compounds. The screening campaign was carried out by investigating the occurrence and removal efficiencies of 93 pharmaceuticals and personal care products (PPCPs) and 5 artificial sweeteners (ASs) in nine wastewater treatment plants (WWTPs) located in the region, and the occurrence of these target compounds in the contaminated and clean surface water of the Pearl River. An ideal wastewater indicator should be hydrophilic, source-specific for domestic wastewater, ubiquitous in contaminated surface water with detection frequency (DF) >80% and absent in background water samples. For liable indicators, high removal rates (>90%) should be observed in WWTPs and they should be detected in all the influent samples at concentrations fifty times higher than their limits of quantification. For conservative indicators, low removal rates (<50%) should be observed in WWTPs and they should be detected in all the effluent samples at concentrations fifty times higher than their limits of quantification. Based on the above criteria, sucralose and fluconazole were selected as conservative indicators in the region, while cyclamate, saccharin, methyl paraben, ethyl paraben, propyl paraben, paracetamol, salicylic acid and caffeine were selected as liable indicators. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Intensive archaeological survey of the F/H Surface Enhancement Project Area, Savannah River Site, Aiken and Barnwell Counties, South Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Sassaman, K.E.; Gillam, J.C.

    1993-08-01

    Twelve archaeological sites and four artifact occurrences were located by intensive survey of two tracts of land for the F and H Surface Enhancement Project on the Savannah River Site, Aiken and Barnwell Counties, South Carolina. Fieldwork in the 480-acre project area included surface reconnaissance of 3.6 linear kilometers of transects, 140 shovel tests along 4.2 linear kilometers of transects, an additional 162 shovel tests at sites and occurrences, and the excavation of six l {times} 2 m test units. All but one of the sites contained artifacts of the prehistoric era; the twelfth site consists of the remains of a twentieth-century home place. The historic site and six of the prehistoric sites consist of limited and/or disturbed contexts of archaeological deposits that have little research potential and are therefore considered ineligible for nomination to the National Register of Historic Places (NRHP). The remaining five sites have sufficient content and integrity to yield information important to ongoing investigations into upland site use. These sites (38AK146, 38AK535, 38AK539, 38AK541, and 38AK543) are thus deemed eligible for nomination to the NRHP and the Savannah River Archaeological Research Program (SRARP) recommends that they be preserved through avoidance or data recovery.

  3. Landsat Big Data Analysis for Detecting Long-Term Water Quality Changes: a Case Study in the Han River, South Korea

    Science.gov (United States)

    Seong, J. C.; Hwang, C. S.; Gibbs, R.; Roh, K.; Mehdi, M. R.; Oh, C.; Jeong, J. J.

    2017-05-01

    Landsat imagery satisfies the characteristics of big data because of its massive data archive since 1972, continuous temporal updates, and various spatial resolutions from different sensors. As a case study of Landsat big data analysis, a total of 776 Landsat scenes were analyzed that cover a part of the Han River in South Korea. A total of eleven sample datasets was taken at the upstream, mid-stream and downstream along the Han River. This research aimed at analyzing locational variance of reflectance, analyzing seasonal difference, finding long-term changes, and modeling algal amount change. There were distinctive reflectance differences among the downstream, mid-stream and upstream areas. Red, green, blue and near-infrared reflectance values decreased significantly toward the upstream. Results also showed that reflectance values are significantly associated with the seasonal factor. In the case of long-term trends, reflectance values have slightly increased in the downstream, while decreased slightly in the mid-stream and upstream. The modeling of chlorophyll-a and Secchi disk depth imply that water clarity has decreased over time while chlorophyll-a amounts have decreased. The decreasing water clarity seems to be attributed to other reasons than chlorophyll-a.

  4. Bioremediation of polycyclic aromatic hydrocarbon (PAH) compounds: (acenaphthene and fluorene) in water using indigenous bacterial species isolated from the Diep and Plankenburg rivers, Western Cape, South Africa.

    Science.gov (United States)

    Alegbeleye, Oluwadara Oluwaseun; Opeolu, Beatrice Olutoyin; Jackson, Vanessa

    2016-11-24

    This study was conducted to investigate the occurrence of PAH degrading microorganisms in two river systems in the Western Cape, South Africa and their ability to degrade two PAH compounds: acenaphthene and fluorene. A total of 19 bacterial isolates were obtained from the Diep and Plankenburg rivers among which four were identified as acenaphthene and fluorene degrading isolates. In simulated batch scale experiments, the optimum temperature for efficient degradation of both compounds was determined in a shaking incubator after 14 days, testing at 25°C, 30°C, 35°C, 37°C, 38°C, 40°C and 45°C followed by experiments in a Stirred Tank Bioreactor using optimum temperature profiles from the batch experiment results. All experiments were run without the addition of supplements, bulking agents, biosurfactants or any other form of biostimulants. Results showed that Raoultella ornithinolytica, Serratia marcescens, Bacillus megaterium and Aeromonas hydrophila efficiently degraded both compounds at 37°C, 37°C, 30°C and 35°C respectively. The degradation of fluorene was more efficient and rapid compared to that of acenaphthene and degradation at Stirred Tank Bioreactor scale was more efficient for all treatments. Raoultella ornithinolytica, Serratia marcescens, Bacillus megaterium and Aeromonas hydrophila degraded a mean total of 98.60%, 95.70%, 90.20% and 99.90% acenaphthene, respectively and 99.90%, 97.90%, 98.40% and 99.50% fluorene, respectively. The PAH degrading microorganisms isolated during this study significantly reduced the concentrations of acenaphthene and fluorene and may be used on a larger, commercial scale to bioremediate PAH contaminated river systems.

  5. Community Based Warning and Evacuation System against Debris Flow in the Upper Jeneberang River, Gowa, South Sulawesi

    Directory of Open Access Journals (Sweden)

    Sutikno Hardjosuwarno

    2008-07-01

    Full Text Available Gigantic collapse of the Caldera wall of Mt. Bawakaraeng (2,830 m in March 2004 had supplied the sediment volume of 230 million to the most upper stream of Jeneberang River, which flowed down to the lower reach in the form of debris flow which is triggered by rainfall. The purpose of the research is to provide a system which is able to forecast the occurrence of debris flow, to identify the weak points along the river course, to identify the hazard areas and how to inform effectively and efficiently the warning messages to the inhabitants in the dangerous area by using the existing modern equipment combined with the traditional one. The standard rainfall which is used to judge the occurrence of debris flow was established by Yano method. It is based on the historical data of rainfall that trigger and not trigger to the occurrence of debris flow which is widely used in Japan so far. The hazard area was estimated by Two-Dimensional Simulation Model for debris flow, the debris flow arrival time at each point in the river were estimated by dividing their distance from reference point by debris flow velocity, where the check dam no. 7-1 in Manimbahoi was designated as reference point. The existing evacuation routes were checked by field survey, the strength and coverage of sound for kentongan and manual siren were examined using sound pressure level at the location of the existing monitoring post and the effectiveness of warning and evacuation were evaluated by comparing the warning and evacuation time against the debris flow arrival time. It was resulted that debris flow occurrence was triggered by short duration of high rainfall intensity, long duration of low rainfall intensity and the outbreak of natural dam which is formed by land slide or bank collapses. The hazard area of upper Jeneberang River are mostly located on the river terraces where the local inhabitants earn their living through cultivating the river terraces as paddy fields, dry

  6. Mercury contamination history of an estuarine floodplain reconstructed from a 210Pb-dated sediment core (Berg River, South Africa)

    CSIR Research Space (South Africa)

    Kading, TJ

    2009-01-01

    Full Text Available .12.08.). Brunke, E.G., Labuschagne, C., Slemr, F., 2001. Gaseous mercury emissions from a fire in the Cape Peninsula, South Africa, during January 2000. Geophysical Research Letters 28, 1483–1486. cbn.co.za, October 2002. Resurrection of Athlone Power Station...

  7. Importance of long-term monitoring for detecting environmental change: lessons from a lowland river in south east England

    Directory of Open Access Journals (Sweden)

    T. P. Burt

    2008-06-01

    Full Text Available Rising nitrate concentrations in rivers and groundwater in regions with intensive agriculture have been of concern for several decades. Long records of nitrate concentration are rare; in the UK, few pre-date 1974. Records from the River Stour from 1937 are analysed using "moving-windows", to explore the effects of window width on trend detection and process inference. Nitrate concentrations rose sharply from the late 1950s in response to widespread ploughing of grassland, but have fallen since the early 1980s, suggesting that widespread nitrogen control measures, which were introduced after the start of the downward trend, may not be the principal driver for recent change. Short windows (5 years are too noisy; longer windows (10, 15 and 30 years identify signals (i.e. trends more reliably. Since system response times can be of the order of 20–30 years, management decisions made on shorter data sets (even up to 15 years could be misleading.

  8. Importance of long-term monitoring for detecting environmental change: lessons from a lowland river in south east England

    Directory of Open Access Journals (Sweden)

    T. P. Burt

    2008-11-01

    Full Text Available Rising nitrate concentrations in rivers and groundwater in regions with intensive agriculture have been of concern for several decades. Long records of nitrate concentration are rare; in the UK, few pre-date 1974. Records from the River Stour from 1937 are analysed using moving-windows to explore the effects of window width on trend detection and process inference. Nitrate concentrations rose sharply from the late 1950s in response to widespread ploughing of grassland, but have fallen since the early 1980s, suggesting that widespread nitrogen control measures, which were introduced after the start of the downward trend, may not be the principal driver for recent change. Short windows (5 years are too noisy; longer windows (10, 15 and 30 years identify signals (i.e. trends more reliably. Since system response times can be of the order of 20–30 years, management decisions made on shorter data sets (even up to 15 years could be misleading.

  9. Isotope constraints on seasonal dynamics of dissolved and particulate N in the Pearl River Estuary, south China

    Science.gov (United States)

    Ye, Feng; Jia, Guodong; Xie, Luhua; Wei, Gangjian; Xu, Jie

    2016-12-01

    Isotope measurements were performed on dissolved NO3-, NH4+, and suspended particulate total N along a salinity gradient in the Pearl River Estuary (PRE) to investigate seasonal changes in main N sources and its biogeochemical processing under the influence of monsoon climate. Our data revealed that municipal sewage and remineralized soil organic N were the major sources of DIN (NO3- and/or NH4+) in freshwater during winter and summer, respectively, whereas phytoplankton biomass was a major component of PN in both seasons. In low-salinity waters (responsible for the decoupling. At high salinities, the greater enrichment in δ18ONO3 than in δ15NNO3 (up to 15.6‰) in winter suggests that atmospheric deposition may contribute to NO3- delivery during the dry season. Overall, these results show the importance of seasonal variability in physical forcing on biological N sources and its turnover processes in the highly dynamic river-dominated estuary.

  10. Geomorphic change along a gravel bed river affected by volcanic eruption: Rio Blanco - Volcan Chaiten (South Chile)

    Science.gov (United States)

    Picco, Lorenzo; Ravazzolo, Diego; Ulloa, Hector; Iroumé, Andres; Aristide Lenzi, Mario

    2014-05-01

    Gravel bed rivers are environments shaped by the balance of flow, sediment regimes, large wood (LW) and vegetation. Geomorphic changes are response to fluctuations and changes of runoff and sediment supply involving mutual interactions among these factors. Typically, many natural disasters (i.e. debris flows, floods and forest fires) can affect the river basin dynamics. Explosive volcanic eruptions present, instead, the potential of exerting severe impacts as, for example, filling river valleys or changing river network patterns thanks to massive deposition of tephra and volcanic sediment all over the main channel and over the basin. These consistent impacts can strongly affect both hydrology and sediment transport dynamics, all over the river system, producing huge geomorphic changes. During the last years there has been a consistent increase in the survey technologies that permit to monitor geomorphic changes and to estimate sediment budgets through repeat topographic surveys. The calculation of differences between subsequent DEMs (difference of DEMs, DoD) is a commonly applied method to analyze and quantify these dynamics. Typically the higher uncertainty values are registered in areas with higher topographic variability and lower point density. This research was conducted along a ~ 2.2 km-long sub-reach of the Blanco River (Southern Chile), a fourth-order stream that presents a mainly rainfall regime with winter peak flows. The May 2008 Chaitén volcanic eruption strongly affected the entire Rio Blanco basin. The entire valley was highly exposed to the pyroclastic and fluvial flows, which affected directly a consistent area of evergreen forests. Extreme runoff from the upper Blanco catchment aggraded the channel and deposited up to several meters of tephra, alluvium, and LW along the entire river system. Aims of this contribution are to define and quantify the short term evolution of the Blanco River after the big eruption event and a subsequent consistent

  11. Multifaceted Value Profiles of Forest Owner Categories in South Sweden: The River Helge å Catchment as a Case Study

    OpenAIRE

    Richnau, Gustav; Angelstam, Per; Valasiuk, Sviataslau; Zahvoyska, Lyudmyla; Axelsson, Robert; Elbakidze, Marine; Farley, Joshua; Jönsson, Ingemar; Soloviy, Ihor

    2013-01-01

    Forest landscapes provide benefits from a wide range of goods, function and intangible values. But what are different forest owner categories’ profiles of economic use and non-use values? This study focuses on the complex forest ownership pattern of the River Helge å catchment including the Kristianstad Vattenrike Biosphere Reserve in southern Sweden. We made 89 telephone interviews with informants representing the four main forest owner categories. Our mapping included consumptive and non-co...

  12. The effect of sewage effluent on the physico-chemical and biological characteristics of the Sand River, Limpopo, South Africa

    Science.gov (United States)

    Seanego, K. G.; Moyo, N. A. G.

    Population growth in urban areas is putting pressure on sewage treatment plants. The improper treatment of sewage entering the aquatic ecosystems causes deterioration of the water quality of the receiving water body. The effect of sewage effluent on the Sand River was assessed. Eight sampling sites were selected, site 1 and 2 were upstream of the sewage treatment plant along the urbanised area of Polokwane, whilst sites 3, 4, 5, 6, 7 and 8 were downstream. The physico-chemical parameters and coliform counts in the water samples were determined. The suitability of the water for irrigation was also determined. Hierarchical average linkage cluster analysis produced two clusters, grouping two sites above the sewage treatment works and six sites downstream of the sewage effluent discharge point. Principal component analysis (PCA) identified total nitrogen, total phosphorus, conductivity and salinity as the major factors contributing to the variability of the Sand River water quality. These factors are strongly associated with the downstream sites. Canonial correspondence analysis (CCA) indicated the macroinvertebrates, Chironomidae, Belastomatidae, Chaoborus and Hirudinea being strongly associated with nitrogen, phosphorus, conductivity and temperature. Escherichia coli levels in the Polokwane wastewater treatment works maturation ponds, could potentially lead to contamination of the Polokwane aquifer. The Sodium Adsorption Ratio was between 1.5 and 3.0 and residual sodium carbonate was below 1.24 Meq/l, indicating that the Sand River water is still suitable for irrigation. The total phosphorus concentrations fluctuated across the different site. Total nitrogen concentrations showed a gradual decrease downstream from the point of discharge. This shows that the river still has a good self-purification capacity.

  13. Characterization and reclamation assessment for the Central Shops Diesel Storage Facility, Savannah River Site, Aiken, South Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Fliermans, C.B.; Hazen, T.C.; Bledsoe, H.

    1993-10-01

    The contamination of subsurface terrestrial environments by organic contaminants is a global phenomenon. The remediation of such environments requires innovative assessment techniques and strategies for successful clean-ups. Central Shops Diesel Storage Facility at Savannah River Site was characterized to determine the extent of subsurface diesel fuel contamination using innovative approaches and effective bioremediation techniques for clean-up of the contaminant plume have been established.

  14. Residual Distribution and Risk Assessment of Polychlorinated Biphenyls in Surface Sediments of the Pearl River Delta, South China.

    Science.gov (United States)

    Lai, Zini; Li, Xiuli; Li, Haiyan; Zhao, Lina; Zeng, Yanyi; Wang, Chao; Gao, Yuan; Liu, Qianfu

    2015-07-01

    We analyzed residual PCBs in surface sediments at 19 sites in the Pearl River Delta in the wet and dry seasons. Seven indicative PCB congeners (PCB28, PCB52, PCB101, PCB118, PCB153, PCB138 and PCB180) were detected in the surface sediments, among which the detection rate and mass concentrations of PCB52 were the highest. Total concentrations of the seven PCBs ranged from 19.8 to 111 μg/kg, with an average of 48.2 μg/kg. For the spatial distribution, the sum of the seven PCB (∑PCB) concentrations for the stations that were located in the city region of the Pearl River Delta were significantly higher than the ∑PCB concentrations for the eight outlets of the Pearl River Delta (p < 0.05). According to the US National Oceanic and Atmospheric Administration ERL and ERM guideline concentrations, the PCB concentrations may occasionally lead to adverse effects, especially in the dry season.

  15. Determination and Distribution of Polycyclic Aromatic Hydrocarbons in Rivers, Sediments and Wastewater Effluents in Vhembe District, South Africa

    Directory of Open Access Journals (Sweden)

    Joshua N. Edokpayi

    2016-03-01

    Full Text Available Polycyclic aromatic hydrocarbons are very toxic and persistent environmental contaminants. This study was undertaken to assess the concentrations and possible sources of 16 PAHs (Polycyclic aromatic hydrocarbons classified by the United State Environmental Protection Agency as priority pollutants in water and sediments of the Mvudi and Nzhelele Rivers. Effluents from Thohoyandou wastewater treatment plant and Siloam waste stabilization ponds were also investigated. Diagnostic ratios were used to evaluate the possible sources of PAHs. PAHs in the water samples were extracted using 1:1 dichloromethane and n-hexane mixtures, while those in the sediment samples were extracted with 1:1 acetone and dichloromethane using an ultrasonication method. The extracts were purified using an SPE technique and reconstituted in n-hexane before analyses with a gas chromatograph time of flight—mass spectrometer. The results obtained indicate the prevalence of high molecular weight PAHs in all the samples. PAHs concentrations in water and sediment samples from all the sampling sites were in the range of 13.174–26.382 mg/L and 27.10–55.93 mg/kg, respectively. Combustion of biomass was identified as the major possible source of PAHs. Effluents from wastewater treatment facilities were also considered as major anthropogenic contributions to the levels of PAHs found in both river water and sediments. Mvudi and Nzhelele Rivers show moderate to high contamination level of PAHs.

  16. Determination and Distribution of Polycyclic Aromatic Hydrocarbons in Rivers, Sediments and Wastewater Effluents in Vhembe District, South Africa.

    Science.gov (United States)

    Edokpayi, Joshua N; Odiyo, John O; Popoola, Oluwaseun E; Msagati, Titus A M

    2016-03-30

    Polycyclic aromatic hydrocarbons are very toxic and persistent environmental contaminants. This study was undertaken to assess the concentrations and possible sources of 16 PAHs (Polycyclic aromatic hydrocarbons) classified by the United State Environmental Protection Agency as priority pollutants in water and sediments of the Mvudi and Nzhelele Rivers. Effluents from Thohoyandou wastewater treatment plant and Siloam waste stabilization ponds were also investigated. Diagnostic ratios were used to evaluate the possible sources of PAHs. PAHs in the water samples were extracted using 1:1 dichloromethane and n-hexane mixtures, while those in the sediment samples were extracted with 1:1 acetone and dichloromethane using an ultrasonication method. The extracts were purified using an SPE technique and reconstituted in n-hexane before analyses with a gas chromatograph time of flight-mass spectrometer. The results obtained indicate the prevalence of high molecular weight PAHs in all the samples. PAHs concentrations in water and sediment samples from all the sampling sites were in the range of 13.174-26.382 mg/L and 27.10-55.93 mg/kg, respectively. Combustion of biomass was identified as the major possible source of PAHs. Effluents from wastewater treatment facilities were also considered as major anthropogenic contributions to the levels of PAHs found in both river water and sediments. Mvudi and Nzhelele Rivers show moderate to high contamination level of PAHs.

  17. Intensive archaeological survey of the proposed Central Sanitary Wastewater Treatment Facility, Savannah River Site, Aiken and Barnwell Counties, South Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Stephenson, D.K.; Sassaman, K.E.

    1993-11-01

    The project area for the proposed Central Sanitary Wastewater Treatment Facility on the Savannah River Site includes a six-acre tract along Fourmile Branch and 18 mi of trunk line corridors. Archaeological investigations of the six-acre parcel resulted in the discovery of one small prehistoric site designated 38AK465. This cultural resource does not have the potential to add significantly to archaeological knowledge of human occupation in the region. The Savannah River Archaeological Research Program (SRARP) therefore recommends that 38AK465 is not eligible for nomination to the National Register of Historic Places (NRHP) and further recommends a determination of no effect. Archaeological survey along the trunk line corridors implicated previously recorded sites 38AK92, 38AK145, 38AK415, 38AK417, 38AK419, and 38AK436. Past disturbance from construction had severely disturbed 38AK92 and no archaeological evidence of 38AK145, 38AK419, and 38AK436 was recovered during survey. Lacking further evidence for the existence of these sites, the SRARP recommends that 38AK92, 38AK145, 38AK419, and 38AK436 are not eligible for nomination to the NRHP and thus warrant a determination of no effect. Two of these sites, 38Ak415 and 38AK417, required further investigation to evaluate their archaeological significance. Both of the sites have the potential to yield significant data on the prehistoric period occupation of the Aiken Plateau and the SRARP recommends that they are eligible for nomination to the NRHP. The Savannah River Archaeological Research Program recommends that adverse effects to sites 38AK415 and 38AK417 from proposed construction can be mitigated through avoidance.

  18. Chemical quality of surface waters, and sedimentation in the Grand River drainage basin, North and South Dakota

    Science.gov (United States)

    Hembree, Charles Herbert; Krieger, Robert A.; Jordan, Paul Robert

    1964-01-01

    An investigation of the chemical quality of surface waters and of the sedimentation in the Grand River drainage basin by the U.S. Geological Survey began in 1946. The chemical quality of the water was studied to obtain information on the nature and amounts of dissolved solids in the streams and on the suitability of the water for domestic, industrial, and irrigation uses. Sedimentation was studied to determine the quantity of sediment that is transported by the streams, the particle sizes of the sediment, and the probable specific weight of the sediment when deposited in a reservoir.

  19. Impact of Brunswick River Mouth Training Walls on Adjacent Beaches,Brunswick Heads, New South Wales, Australia

    Institute of Scientific and Technical Information of China (English)

    HUANG Hai-jun (黄海军); Andrew D. SHORT; Thomas ZENG; David HANSLOW

    2004-01-01

    River training walls have been built at scores of locations along the NSW coast and their impacts on shoreline change are still not fully understood. In this study, the Bnmswick River entrance and adjacent beaches are selected for examination of the impact of the construction of major training walls. Thirteen sets of aerial photographs taken between 1947 and 1994 are used in a GIS approach to accurately determine the shoreline position, beach contours and sand volumes, and their changes in both time and space, and then to assess the contribution of both the structures and natural hydrodynamic conditions to large scale (years-decades and kilometres) beach changes. The impact of the training walls can be divided into four stages: natural conditions prior to their construction (pre 1959), major downdrift erosion and updrift accretion during and following the construction of the walls in 1959 ~ 1962 and 1966, diminishing impact of the walls between 1966and 1987, and finally no apparent impact between 1987 ~ 1994. The impact extends horizontally about 8 km updrift and 17 km downdrift, and temporally up to 25 years.

  20. First DNA Barcode Reference Library for the Identification of South American Freshwater Fish from the Lower Paraná River

    Science.gov (United States)

    Brancolini, Florencia; del Pazo, Felipe; Posner, Victoria Maria; Grimberg, Alexis; Arranz, Silvia Eda

    2016-01-01

    Valid fish species identification is essential for biodiversity conservation and fisheries management. Here, we provide a sequence reference library based on mitochondrial cytochrome c oxidase subunit I for a valid identification of 79 freshwater fish species from the Lower Paraná River. Neighbour-joining analysis based on K2P genetic distances formed non-overlapping clusters for almost all species with a ≥99% bootstrap support each. Identification was successful for 97.8% of species as the minimum genetic distance to the nearest neighbour exceeded the maximum intraspecific distance in all these cases. A barcoding gap of 2.5% was apparent for the whole data set with the exception of four cases. Within-species distances ranged from 0.00% to 7.59%, while interspecific distances varied between 4.06% and 19.98%, without considering Odontesthes species with a minimum genetic distance of 0%. Sequence library validation was performed by applying BOLDs BIN analysis tool, Poisson Tree Processes model and Automatic Barcode Gap Discovery, along with a reliable taxonomic assignment by experts. Exhaustive revision of vouchers was performed when a conflicting assignment was detected after sequence analysis and BIN discordance evaluation. Thus, the sequence library presented here can be confidently used as a benchmark for identification of half of the fish species recorded for the Lower Paraná River. PMID:27442116

  1. Ground-Water Budgets for the Wood River Valley Aquifer System, South-Central Idaho, 1995-2004

    Science.gov (United States)

    Bartolino, James R.

    2009-01-01

    The Wood River Valley contains most of the population of Blaine County and the cities of Sun Valley, Ketchum, Haley, and Bellevue. This mountain valley is underlain by the alluvial Wood River Valley aquifer system which consists of a single unconfined aquifer that underlies the entire valley, an underlying confined aquifer that is present only in the southernmost valley, and the confining unit that separates them. The entire population of the area depends on ground water for domestic supply, either from domestic or municipal-supply wells, and rapid population growth since the 1970s has caused concern about the long-term sustainability of the ground-water resource. To help address these concerns this report describes a ground-water budget developed for the Wood River Valley aquifer system for three selected time periods: average conditions for the 10-year period 1995-2004, and the single years of 1995 and 2001. The 10-year period 1995-2004 represents a range of conditions in the recent past for which measured data exist. Water years 1995 and 2001 represent the wettest and driest years, respectively, within the 10-year period based on precipitation at the Ketchum Ranger Station. Recharge or inflow to the Wood River Valley aquifer system occurs through seven main sources (from largest to smallest): infiltration from tributary canyons, streamflow loss from the Big Wood River, areal recharge from precipitation and applied irrigation water, seepage from canals and recharge pits, leakage from municipal pipes, percolation from septic systems, and subsurface inflow beneath the Big Wood River in the northern end of the valley. Total estimated mean annual inflow or recharge to the aquifer system for 1995-2004 is 270,000 acre-ft/yr (370 ft3/s). Total recharge for the wet year 1995 and the dry year 2001 is estimated to be 270,000 acre-ft/yr (370 ft3/s) and 220,000 acre-ft/yr (300 ft3/s), respectively. Discharge or outflow from the Wood River Valley aquifer system occurs through

  2. Elevated Concentrations of Primordial Radionuclides in Sediments from the Reedy River and Surrounding Creeks in Simpsonville, South Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Powell, B A; Hughes, L D; Soreefan, A M; Falta, D; Wall, M; DeVol, T A

    2006-12-27

    A gamma-ray survey and analysis of sixteen riverbed samples from the Reedy River watershed near Simpsonville, SC were conducted and compared with national and international studies of primordial radionuclides. The study reported here follows on a recent discovery of anomalously high uranium concentrations in several private well waters in the area near Simpsonville, SC. A HPGe spectrometer was used for quantification of gamma emitting radionuclides in the sediments. All sediments contained radionuclides from the uranium and thorium series as well as {sup 40}K. Uranium-238 concentrations in sediment samples ranged from 11.1 to 74.2 Bq kg{sup -1}. The measured radionuclide concentrations were compared with data from UNSCEAR and NURE reports. The river and stream sediment data were augmented by in situ NaI(Tl) gamma-ray spectrometer measurements. Comparisons between the ex-situ and in-situ measurements indicate equivalently distributed uranium in the surface soils and stream sediments, the source of which is likely attributed to the monazite belts that are known to exist in the area.

  3. Elevated concentrations of primordial radionuclides in sediments from the Reedy River and surrounding creeks in Simpsonville, South Carolina.

    Science.gov (United States)

    Powell, Brian A; Hughes, Lara D; Soreefan, Aurelie M; Falta, Deborah; Wall, Michael; DeVol, Timothy A

    2007-01-01

    A gamma-ray survey and analysis of 16 riverbed samples from the Reedy River watershed near Simpsonville, SC were conducted and compared with national and international studies of primordial radionuclides. The study reported here follows on a recent discovery of anomalously high uranium concentrations in several private well waters in the area. An HPGe spectrometer was used for quantification of gamma emitting radionuclides in the sediments. All sediments contained radionuclides from the uranium and thorium series as well as (40)K. Uranium-238 concentrations in sediment samples ranged from 11.1 to 74.2Bqkg(-1). The measured radionuclide concentrations were compared with data from UNSCEAR and NURE reports. The river and stream sediment data were augmented by in situ NaI(Tl) gamma-ray spectrometer measurements. Comparisons between the ex situ and in situ measurements indicate equivalently distributed uranium in the surface soils and stream sediments, the source of which is likely attributed to the monazite belts that are known to exist in the area.

  4. Elevated concentrations of primordial radionuclides in sediments from the Reedy River and surrounding creeks in Simpsonville, South Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Powell, Brian A. [Clemson University, Department of Environmental Engineering and Science, 342 Computer Court, Clemson, SC 29634-0919 (United States); Hughes, Lara D. [Clemson University, Department of Environmental Engineering and Science, 342 Computer Court, Clemson, SC 29634-0919 (United States); Soreefan, Aurelie M. [Clemson University, Department of Environmental Engineering and Science, 342 Computer Court, Clemson, SC 29634-0919 (United States); Falta, Deborah [Clemson University, Department of Environmental Engineering and Science, 342 Computer Court, Clemson, SC 29634-0919 (United States); Wall, Michael [Clemson University, Department of Environmental Engineering and Science, 342 Computer Court, Clemson, SC 29634-0919 (United States); DeVol, Timothy A. [Clemson University, Department of Environmental Engineering and Science, 342 Computer Court, Clemson, SC 29634-0919 (United States)]. E-mail: tim.devol@ces.clemson.edu

    2007-05-15

    A gamma-ray survey and analysis of 16 riverbed samples from the Reedy River watershed near Simpsonville, SC were conducted and compared with national and international studies of primordial radionuclides. The study reported here follows on a recent discovery of anomalously high uranium concentrations in several private well waters in the area. An HPGe spectrometer was used for quantification of gamma emitting radionuclides in the sediments. All sediments contained radionuclides from the uranium and thorium series as well as {sup 40}K. Uranium-238 concentrations in sediment samples ranged from 11.1 to 74.2 Bq kg{sup -1}. The measured radionuclide concentrations were compared with data from UNSCEAR and NURE reports. The river and stream sediment data were augmented by in situ NaI(Tl) gamma-ray spectrometer measurements. Comparisons between the ex situ and in situ measurements indicate equivalently distributed uranium in the surface soils and stream sediments, the source of which is likely attributed to the monazite belts that are known to exist in the area.

  5. Rainfall and runoff water quality of the Pang and Lambourn, tributaries of the River Thames, south-eastern England

    Directory of Open Access Journals (Sweden)

    C. Neal

    2004-01-01

    Full Text Available The water quality of rainfall and runoff is described for two catchments of two tributaries of the River Thames, the Pang and Lambourn. Rainfall chemistry is variable and concentrations of most determinands decrease with increasing volume of catch probably due to 'wash out' processes. Two rainfall sites have been monitored, one for each catchment. The rainfall site on the Lambourn shows higher chemical concentrations than the one for the Pang which probably reflects higher amounts of local inputs from agricultural activity. Rainfall quality data at a long-term rainfall site on the Pang (UK National Air Quality Archive shows chemistries similar to that for the Lambourn site, but with some clear differences. Rainfall chemistries show considerable variation on an event-to-event basis. Average water quality concentrations and flow-weighted concentrations as well as fluxes vary across the sites, typically by about 30%. Stream chemistry is much less variable due to the main source of water coming from aquifer sources of high storage. The relationship between rainfall and runoff chemistry at the catchment outlet is described in terms of the relative proportions of atmospheric and within-catchment sources. Remarkably, in view of the quantity of agricultural and sewage inputs to the streams, the catchments appear to be retaining both P and N. Keywords: water quality, nitrate, ammonium, phosphorus, ammonia, nitrogen dioxide, pH, alkalinity, nutrients, trace metals, rainfall, river, Pang, Lambourn, LOCAR

  6. Re-analysis of the hominid radii from Cave of Hearths and Klasies River Mouth, South Africa.

    Science.gov (United States)

    Pearson, O M; Grine, F E

    1997-06-01

    Two of the few postcranial fragments from the late Early Stone Age and/or the Middle Stone Age of southern Africa are the proximal radii from the Cave of Hearths and Klasies River Mouth. The Cave of Hearths fossil is metrically indistinguishable from both archaic (e.g., Neandertals) and recent humans, and presents a mosaic of primitive and modern features. The primitive include a relatively slender neck and thick cortical bone (the latter of which distinguishes recent humans from archaic, Early Modern, and Upper Paleolithic hominids); the modern includes an anteromedially (rather than medially) facing radial tuberosity. Its extreme collo-diaphyseal angle is unusual, although it can be matched by modern homologues. The neck-shaft angle of some Neandetral and Early Modern radii also appears to match that of the Cave of Hearths specimen. The Klasies River Mouth radius also has thick cortical bone of the neck. It is morphologically indistinguishable from Early Modern and Neandertal homologues. These, and other fossils, suggest a mosaic pattern of evolution in the postcranial skeleton of the late Early Stone Age and/or Middle Stone Age inhabitants of sub-Saharan Africa.

  7. The role of flowering plant species in the survival of blackflies (Diptera: Simuliidae along the lower Orange River, South Africa

    Directory of Open Access Journals (Sweden)

    E. Myburgh

    2001-08-01

    Full Text Available This study is an investigation of the role that plants play in the survival of adult blackflies by providing shelter and carbohydrate food. A detailed phenological study of the 29 most abundant plant species in the Augrabies Falls National Park showed that throughout the year the percentage of plant species flowering was remarkably constant. It is therefore unlikely that the availability of carbohydrates would limit adult Simulium survival at any time of the year. Blackflies were recorded feeding on the flowers of Pappea capensis. Acacia karroo, A. mellifera, Tamarix usneoides, Ziziphus mucronata, Scholia afra and Sisyndite spartea. An additional survey showed that another 64 plant species flowered throughout the year, and these can be regarded as potential carbohydrate sources. Blackflies were observed sheltering in dense shrubs and trees that provide protection against predation and harsh environmental conditions. This study suggests that vegetated drainage lines are the means by which adult blackflies survive dispersal away from the river. It is concluded that carbohydrate scarcity cannot be considered a limiting factor to adult blackfly survival along the lower Orange River.

  8. Effects of aquifer storage and recovery activities on water quality in the Little Arkansas River and Equus Beds Aquifer, south-central Kansas, 2011-14

    Science.gov (United States)

    Stone, Mandy L.; Garrett, Jessica D.; Poulton, Barry C.; Ziegler, Andrew C.

    2016-07-18

    The Equus Beds aquifer in south-central Kansas is aprimary water source for the city of Wichita. The Equus Beds aquifer storage and recovery (ASR) project was developed to help the city of Wichita meet increasing current (2016) and future water demands. The Equus Beds ASR project pumps water out of the Little Arkansas River during above-base flow conditions, treats it using drinking-water quality standards as a guideline, and recharges it into the Equus Beds aquifer for later use. Phase II of the Equus Beds ASR project currently (2016) includes a river intake facility and a surface-water treatment facility with a 30 million gallon per day capacity. Water diverted from the Little Arkansas River is delivered to an adjacent presedimentation basin for solids removal. Subsequently, waste from the surface-water treatment facility and the presedimentation basin is returned to the Little Arkansas River through a residuals return line. The U.S. Geological Survey, in cooperation with the city of Wichita, developed and implemented a hydrobiological monitoring program as part of the ASR project to characterize and quantify the effects of aquifer storage and recovery activities on the Little Arkansas River and Equus Beds aquifer water quality.Data were collected from 2 surface-water sites (one upstream and one downstream from the residuals return line), 1 residuals return line site, and 2 groundwater well sites (each having a shallow and deep part): the Little Arkansas River upstream from the ASR facility near Sedgwick, Kansas (upstream surface-water site 375350097262800), about 0.03 mile (mi) upstream from the residuals return line site; the Little Arkansas River near Sedgwick, Kans. (downstream surface-water site 07144100), about 1.68 mi downstream from the residuals return line site; discharge from the Little Arkansas River ASR facility near Sedgwick, Kansas (residuals return line site 375348097262800); 25S 01 W 07BCCC01 SMW–S11 near CW36 (MW–7 shallow groundwater well

  9. Rivers through time: historical changes in the riparian vegetation of the semi-arid, winter rainfall region of South Africa in response to climate and land use.

    Science.gov (United States)

    Hoffman, M Timm; Rohde, Richard Frederick

    2011-01-01

    This paper examines how the riparian vegetation of perennial and ephemeral rivers systems in the semi-arid, winter rainfall region of South Africa has changed over time. Using an environmental history approach we assess the extent of change in plant cover at 32 sites using repeat photographs that cover a time span of 36-113 years. The results indicate that in the majority of sites there has been a significant increase in cover of riparian vegetation in both the channel beds and adjacent floodplain environments. The most important species to have increased in cover across the region is Acacia karroo. We interpret the findings in the context of historical changes in climate and land use practices. Damage to riparian vegetation caused by mega-herbivores probably ceased sometime during the early 19th century as did scouring events related to large floods that occurred at regular intervals from the 15th to early 20th centuries. Extensive cutting of riparian vegetation for charcoal and firewood has also declined over the last 150 years. Changes in the grazing history as well as increased abstraction and dam building along perennial rivers in the region also account for some of the changes observed in riparian vegetation during the second half of the 20th century. Predictions of climate change related to global warming anticipate increased drought events with the subsequent loss of species and habitats in the study area. The evidence presented here suggests that an awareness of the region's historical ecology should be considered more carefully in the modelling and formulation of future climate change predictions as well as in the understanding of climate change impacts over time frames of decades and centuries.

  10. Bioaccumulation of polybrominated diphenyl ethers and decabromodiphenyl ethane in fish from a river system in a highly industrialized area, South China

    Energy Technology Data Exchange (ETDEWEB)

    He, Ming-Jing [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Luo, Xiao-Jun, E-mail: luoxiaoj@gig.ac.cn [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Chen, Man-Ying; Sun, Yu-Xin [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Chen, She-Jun; Mai, Bi-Xian [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China)

    2012-03-01

    Polybrominated diphenyl ethers (PBDEs) and decabromodiphenyl ethane (DBDPE) were determined in water, sediment, and three fish species from the Dongjiang River, a highly polluted river by brominated flame retardants in South China due to the intensive industry activities. The stable isotope analysis was used to compare differences between the feeding ecology of the fish species. The bioaccumulations of PBDEs and DBDPE were evaluated by calculation of bioaccumulation factors (BAFs) and biota-sediment accumulation factors (BSAFs). Two potential debromination products of DBDPE were detected in sediment. The occurrence of these two compounds probably ascribed to the thermal degradation during instrumental analysis but degradation in the environment cannot be ruled out. Three fish species showed two quite different PBDE congener profiles. Two carp species were dominated by BDE47 while plecostomus were dominated by both BDE47 and BDE99. The contributions of higher brominated congeners were higher in plecostomus than in two carp species. This different PBDE congener profile can be attributed to the difference in metabolism and feeding habits among fish species. The calculated BAFs for PBDE congeners follow a bioaccumulation model. The BSAFs for all PBDE congeners except for BDE47 and BDE100 were less than unit, implying that bioavailability of PBDEs in sediments is low. Contrary to expectation, the BAFs value of DBDPE was one order of magnitude higher than that of BDE209 in fish, which can partly attributed to the absence of debromination of DBDPE in fish. The calculated BAFs for DBDPE indicated that this compound can significantly accumulate in fish. - Highlights: Black-Right-Pointing-Pointer Deca-BDE had gradually substituted by DBDPE in study area. Black-Right-Pointing-Pointer Two debrominated products of DBDPE were the result of thermal degradation in instrumental analysis. Black-Right-Pointing-Pointer Metabolism and diet were causes for the different PBDE congener

  11. Crop yield risk analysis and mitigation of smallholder farmers at quaternary catchment level: Case study of B72A in Olifants river basin, South Africa

    Science.gov (United States)

    Magombeyi, Manuel S.; Taigbenu, Akpofure E.

    Currently, Sub-Sahara is experiencing increased frequency of disasters either as floods or droughts which depletes the scarce resources available to sustain increasing populations. Success in preventing food shortages in the African continent can only be achieved by understanding the vulnerability and risk of the majority of smallholder farmers under rainfed and supplementary irrigation coupled with appropriate interventions. Increased frequency of floods, droughts and dry spells pose an increasing threat to the smallholder farmers’ food security and water resources availability in B72A quaternary catchment of the Olifants river basin in South Africa. This paper links maize crop yield risk and smallholder farmer vulnerability arising from droughts by applying a set of interdisciplinary indicators (physical and socio-economic) encompassing gender and institutional vulnerabilities. For the study area, the return period of droughts and dry spells was 2 years. The growing season for maize crop was 121 days on average. Soil water deficit during critical growth stages may reduce potential yields by up to 62%, depending on the length and severity of the moisture deficit. To minimize grain yield loss and avoid total crop failures from intra-seasonal dry spells, farmers applied supplementary irrigation either from river water or rainwater harvested into small reservoirs. Institutional vulnerability was evidenced by disjointed water management institutions with lack of comprehension of roles of higher level institutions by lower level ones. Women are most hit by droughts as they derived more than 90% of their family income from agriculture activities. An enhanced understanding of the vulnerability and risk exposure will assist in developing technologies and policies that conform to the current livelihood strategies of smallholder, resource-constrained farmers. Development of such knowledge base for a catchment opens avenues for computational modeling of the impacts of

  12. Rectification of historical topographic maps: a tool revealing the course changes and dynamics of Lower Gaula River, South Trondelag, Norway

    Science.gov (United States)

    Timár, Gábor; Baranya, Sándor; Rüther, Nils; Kvarteig, Sidsel; Galambos, Csilla; Biszak, Előd; Nagy, Diána

    2017-04-01

    The 1:50,000 and 1:100,000 scale historical sheets of the Norwegian topographic 'Rektangelkart' map series were georeferenced, in order to obtain the original hydrography of the Gaula River, at a ca 50 kilometer long section between Støren and the estuary to the Gulosen Bay. The 1:50,000 scale sheets are the earliest systematic topographic works of the area, surveyed in 1866-9, while the smaller scale sheets were surveyed forty years later, in 1906-8. Both series represent a river status before the extensive control works. Thus, together with the modern, present-day cartographic and GIS products, these two 'snapshots' from 100 and 150 years ago show not only the original, uncontrolled status of the river but also some elements of the natural changes of the course/thalweg. To make the georeference, instead of using terrain points, the geodetic parameters of the Norwegian 'Rektangelkart' series were defined in GIS environment. The Cassini map projection was defined with a projection center in the fortress of Kongsvinger, Eastern Norway, some 350 kilometers from the study area. Knowing the sheet labeling system and the terrain position of the sheets in this Cassini projection, only their four corner points were defined in all sheets. The accuracy of the horizontal control of georeferenced was less than half map millimeter (25/50 meters). The sheets show an interesting meander cutoff process between Ler and Kvål. In 1869, the meander curve is still active and fully operating. A cutoff channel is clearly mapped in 1906, together with the old one. Nowadays, almost no map signs show the old channel course, however in the field, it is still traceable. Another interesting map element shows the complete bar structure in the channel. These gravel bars showed a different pattern in the old maps, as there were more gravel sediments in the time before the building of upspring reservoirs. Gravel bars are important in some environmental processes, eg. as salmon habitats, This

  13. Modelling of INTER-Linkages Between LAND Cover Pattern and Socio-Economic Factors in the Idemili River Basin of South Eastern Nigeria

    Science.gov (United States)

    Maduekwe, N. I.; Adesina, F. A.

    2014-12-01

    This study explores the inter-relationships between socio-economic factors and land cover pattern in the Idemili River Basin of South Eastern Nigeria. It is based on the concept of coupled human environment systems and focuses on the modelling of community scale relationships between critical land cover parameter and socio-demographic, economic and cultural factors in the basin. The modelling was implemented with pixel level NDVI indicators of vegetation cover density developed from NigeriaSat image with 32m resolution linked to eight indicators of socio-economic factors developed from a household survey of the basin. NDVI and socio-economic data were matched for 25 sampled localities in the basin and their relationships modelled with correlation, regression and Principal Component Analysis statistics. NDVI based image analysis showed a high level of human impact on vegetation. The Model output shows that bivariate relationships between vegetation cover dynamics and socio-demographic variables were the most significant, with R Square values > 0.60 for linear and non linear models. Vegetation cover density has high inverse correlations with population, urbanization levels and number of households in localities. Population/urbanization status of localities was also the most significant Principal Component or underlying dimension linked to spatial dynamics of vegetation cover in the basin accounting for 50% of factor variations. Relationships between vegetation cover densities and economic factors (occupational and household energy patterns) and socio-cultural factors (environmental knowledge, values and governance) were weaker and less significant. The study captured the linkages between landcover- represented by vegetation cover- and socio-economic parameters. It demonstrates that socio-economic factors are major drivers of change in the basin. Key Words: Socio-economic factors, Vegetation Cover, NDVI, Socio-ecological Systems, State Variables, South Eastern Nigeria

  14. An Economic Valuation Of The Water Footprint: A Case Study Of The Citrus Sector In The Lower Sundays River Valley, Eastern Cape, South Africa.

    Science.gov (United States)

    Munro, S. A.; Fraser, G. C. G.; Snowball, J. D.

    2014-12-01

    With the implementation of the South African National Water Act (NWA) currently underway, water intensive sectors, such as the irrigated agriculture sector, can expect reduced water allocations and an increase in water prices. Water footprints (WFs) are increasingly being recognised as a meaningful way by which to represent human appropriation of water resources. This study examines the green and blue WFs of a variety of citrus cultivars in the lower Sundays River Valley, Eastern Cape, South Africa. WFs were calculated across dry, humid and long-term average climates and comparisons were made to available global average benchmark WFs. An number of indicators were also explored including; water productivity (ton/m3), economic land productivity (R/ha) and economic water productivity (R/m3) across all three climatic years. Most applications of WF sustainability assessments have focused on examining physical water scarcity as a measure for determining environmental hotspots. This study, therefore, also calculates the marginal product value for the irrigation water using a non-parametric linear programming approach. Marginal product value of irrigation water is not only useful in assisting with water-allocation decision making, but also useful in demonstrating the effects of resource depletion and degradation, and is therefore a useful measure for determining economic water scarcity. The study highlights that both farmers and governments could reduce blue WF's through adopting measures to increase water efficiency and considering economic water and land productivity. It also demonstrates the importance of including both environmental and economic scarcity indicators into water management and planning strategies, and the importance of conducting WF assessments using more accurate, site specific data.

  15. Multifaceted value profiles of forest owner categories in south Sweden: the River Helge å catchment as a case study.

    Science.gov (United States)

    Richnau, Gustav; Angelstam, Per; Valasiuk, Sviataslau; Zahvoyska, Lyudmyla; Axelsson, Robert; Elbakidze, Marine; Farley, Joshua; Jönsson, Ingemar; Soloviy, Ihor

    2013-03-01

    Forest landscapes provide benefits from a wide range of goods, function and intangible values. But what are different forest owner categories' profiles of economic use and non-use values? This study focuses on the complex forest ownership pattern of the River Helge å catchment including the Kristianstad Vattenrike Biosphere Reserve in southern Sweden. We made 89 telephone interviews with informants representing the four main forest owner categories. Our mapping included consumptive and non-consumptive direct use values, indirect use values, and non-use values such as natural and cultural heritage. While the value profiles of non-industrial forest land owners and municipalities included all value categories, the forest companies focused on wood production, and the Swedish Environmental Protection Agency on nature protection. We discuss the challenges of communicating different forest owners' economic value profiles among stakeholders, the need for a broader suite of forest management systems, and fora for collaborative planning.

  16. Structural study of the tectonics of the basement phyllites - quartzites (Verrucano) in Tuscany south of the Arno river

    Energy Technology Data Exchange (ETDEWEB)

    Giannini, E. (Instituto di Geologia e Paleontologia, Sienna, IT); Lazzarotto, A.; Stefani, G.

    1970-01-01

    Problems of Tuscan geology in the area of the southern Arno river are discussed. Particular attention is given to the tectonics of the autochtonous Tuscan series and its relationship with the Ligurian allochtonous and Umbrian autochtonous series. This area is difficult to study as there are few outcrops present and the surface structure does not reflect the subsurface structure. The results of new studies of the area, including detailed investigations and analyses of drill cores from wells excavated by the Larderello Co. and ENEL are reported. The structure of the area has been accurately mapped and the historical geology, particularly with respect to tectonics, has been reconstructed. This data will be of assistance in the interpretation of thermal phenomena in southern Italy.

  17. Constructing an Alpine Fault Paleoseismicity Record from Slumped Lacustrine Deposits in the Cascade River Valley, South Westland, New Zealand

    Science.gov (United States)

    Coffey, G.; Moy, C. M.; Toy, V. G.; Ohneiser, C.; Howarth, J. D.

    2014-12-01

    The Alpine Fault is a major structure in New Zealand capable of producing earthquakes of magnitude 7 or greater, which delineates the boundary between the Australian and Pacific plates. Paleoseismic records of these earthquakes indicate recurrence intervals of 300 - 400 years over the last 1,300 years. However, there are no pre-Holocene records. Documenting the late Pleistocene record of magnitude, timing, and frequency of earthquakes would significantly reduce uncertainty in hazard analyses. The tectonically complex Cascade River Valley follows the Southern Alpine Fault, where the fault dominantly accommodates strike-slip motion. Two ~7m outcrops of proglacial lacustrine silt are exposed along the river in which, deformed rhythmites bounded by planar laminated rhythmites have been identified. These exhibit a variety of fold geometries in outcrop and x-ray computed tomography (CT) scans, all of which show some degree of asymmetry. Initial radiocarbon ages of 14,400 and 13,300 14C yr BP have been obtained from terrestrial plant material isolated from samples near the base of one outcrop. Given the age range and laminae density, these dates suggest that the rhythmites are varves, but additional radiocarbon dates and CT-scans will be used to confirm this. The deformed horizons are interpreted to be seismites formed by slumping. Earthquake shaking triggers an increase in pore fluid pressure, which destabilises the sublacustrine slope causing failure and the release of silt into the sedimentary system. As silt is transported by downslope shear it is deformed in distinct layers. Displacement of volumes of silt also causes the formation of seiche waves that apply shear stress to lake floor sediments causing further deformation. Deviations in magnetic susceptibility and the declination of magnetic remanence observed underneath and within deformed horizons are interpreted to be a response of earthquake shaking. Data from these different proxies will be presented and

  18. Sedimentary record of polycyclic aromatic hydrocarbons in a sediment core from the Pearl River Estuary, South China.

    Science.gov (United States)

    Liu, G Q; Zhang, G; Li, X D; Li, J; Peng, X Z; Qi, S H

    2005-01-01

    Owing to the hydrodynamic and sedimentation conditions, the western shoal of the Pearl River Estuary (PRE) is known to be an important sink of terrestrial substances including particle-associated pollutants from the Pearl River Delta (PRD) region. In this study, we report the sedimentary record of polycyclic aromatic hydrocarbons (PAHs) during the 20(th) century in a sediment core from the western shoal of the PRE. The summation PAH concentration ranged from 59 ng g(-1) to 330 ng g(-1) in the core with two distinct peaks. An initial increase of summation PAH concentration was found around the 1860s. The amounts of PAHs remained relatively constant for roughly 100 years, followed by the first peak in the 1950s. Then, there was a decrease in PAH concentration and flux in the 1960s and 1970s. A sharp increase of PAH concentration was observed in the early 1980s with a maximum concentration in the 1990s. The PAH diagnostic ratios indicated that the PAHs in the sediment core were mainly of pyrolytic origin, and that atmospheric deposition and land runoff may serve as the important pathways for PAHs input to the sediment. The Gross Domestic Product (GDP) was used as an index of socioeconomic development in the PRD region, which was correlated positively with the changes of PAH concentration and flux in the sediment core. The rapid increase in vehicle numbers and energy consumption in the region in the last two decades may have contributed to the rapid PAH increase since the early 1980s. The results clearly elucidated the impact of regional economic development on the estuarine environment.

  19. Dynamics of submarine groundwater discharge and associated fluxes of dissolved nutrients, carbon, and trace gases to the coastal zone (Okatee River estuary, South Carolina)

    Science.gov (United States)

    Porubsky, W.P.; Weston, N.B.; Moore, W.S.; Ruppel, C.; Joye, S.B.

    2014-01-01

    Multiple techniques, including thermal infrared aerial remote sensing, geophysical and geological data, geochemical characterization and radium isotopes, were used to evaluate the role of groundwater as a source of dissolved nutrients, carbon, and trace gases to the Okatee River estuary, South Carolina. Thermal infrared aerial remote sensing surveys illustrated the presence of multiple submarine groundwater discharge sites in Okatee headwaters. Significant relationships were observed between groundwater geochemical constituents and 226Ra activity in groundwater with higher 226Ra activity correlated to higher concentrations of organics, dissolved inorganic carbon, nutrients, and trace gases to the Okatee system. A system-level radium mass balance confirmed a substantial submarine groundwater discharge contribution of these constituents to the Okatee River. Diffusive benthic flux measurements and potential denitrification rate assays tracked the fate of constituents in creek bank sediments. Diffusive benthic fluxes were substantially lower than calculated radium-based submarine groundwater discharge inputs, showing that advection of groundwater-derived nutrients dominated fluxes in the system. While a considerable potential for denitrification in tidal creek bank sediments was noted, in situ denitrification rates were nitrate-limited, making intertidal sediments an inefficient nitrogen sink in this system. Groundwater geochemical data indicated significant differences in groundwater chemical composition and radium activity ratios between the eastern and western sides of the river; these likely arose from the distinct hydrological regimes observed in each area. Groundwater from the western side of the Okatee headwaters was characterized by higher concentrations of dissolved organic and inorganic carbon, dissolved organic nitrogen, inorganic nutrients and reduced metabolites and trace gases, i.e. methane and nitrous oxide, than groundwater from the eastern side

  20. Trends In Nutrient and Sediment Concentrations and Loads In Major River Basins of the South-Central United States, 1993-2004

    Science.gov (United States)

    Rebich, Richard A.; Demcheck, Dennis K.

    2008-01-01

    Nutrient and sediment data collected at 115 sites by Federal and State agencies from 1993 to 2004 were analyzed by the U.S. Geological Survey to determine trends in concentrations and loads for selected rivers and streams that drain into the northwestern Gulf of Mexico from the south-central United States, specifically from the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf Basins. Trends observed in the study area were compared to determine potential regional patterns and to determine cause-effect relations with trends in hydrologic and human-induced factors such as nutrient sources, streamflow, and implementation of best management practices. Secondary objectives included calculation of loads and yields for the study period as a basis for comparing the delivery of nutrients and sediment to the northwestern Gulf of Mexico from the various rivers within the study area. In addition, loads were assessed at seven selected sites for the period 1980-2004 to give hydrologic perspective to trends in loads observed during 1993-2004. Most study sites (about 64 percent) either had no trends or decreasing trends in streamflow during the study period. The regional pattern of decreasing trends in streamflow during the study period appeared to correspond to moist conditions at the beginning of the study period and the influence of three drought periods during the study period, of which the most extreme was in 2000. Trend tests were completed for ammonia at 49 sites, for nitrite plus nitrate at 69 sites, and for total nitrogen at 41 sites. For all nitrogen constituents analyzed, no trends were observed at half or more of the sites. No regional trend patterns could be confirmed because there was poor spatial representation of the trend sites. Decreasing trends in flow-adjusted concentrations of ammonia were observed at 25 sites. No increasing trends in concentrations of ammonia were noted at any sites. Flow-adjusted concentrations of nitrite plus nitrate decreased at 7

  1. South Asian summer monsoon variability during the last ˜54 kyrs inferred from surface water salinity and river runoff proxies

    Science.gov (United States)

    Gebregiorgis, D.; Hathorne, E. C.; Sijinkumar, A. V.; Nath, B. Nagender; Nürnberg, D.; Frank, M.

    2016-04-01

    The past variability of the South Asian Monsoon is mostly known from records of wind strength over the Arabian Sea while high-resolution paleorecords from regions of strong monsoon precipitation are still lacking. Here, we present records of past monsoon variability obtained from sediment core SK 168/GC-1, which was collected at the Alcock Seamount complex in the Andaman Sea. We utilize the ecological habitats of different planktic foraminiferal species to reconstruct freshwater-induced stratification based on paired Mg/Ca and δ18O analyses and to estimate seawater δ18O (δ18Osw). The difference between surface and thermocline temperatures (ΔT) and δ18Osw (Δδ18Osw) is used to investigate changes in upper ocean stratification. Additionally, Ba/Ca in G. sacculifer tests is used as a direct proxy for riverine runoff and sea surface salinity (SSS) changes related to monsoon precipitation on land. Our Δδ18Osw time series reveals that upper ocean salinity stratification did not change significantly throughout the last glacial suggesting little influence of NH insolation changes. The strongest increase in temperature gradients between the mixed layer and the thermocline is recorded for the mid-Holocene and indicate the presence of a significantly shallower thermocline. In line with previous work, the δ18Osw and Ba/Ca records demonstrate that monsoon climate during the LGM was characterized by a significantly weaker southwest monsoon circulation and strongly reduced runoff. Based on our data the South Asian Summer Monsoon (SAM) over the Irrawaddyy strengthened gradually after the LGM beginning at ∼18 ka. This is some 3 kyrs before an increase of the Ba/Ca record from the Arabian Sea and indicates that South Asian Monsoon climate dynamics are more complex than the simple N-S displacement of the ITCZ as generally described for other regions. Minimum δ18Osw values recorded during the mid-Holocene are in phase with Ba/Ca marking a stronger monsoon precipitation

  2. A comparison study of summer-time synoptic-scale waves in South China and the Yangtze River basin using the TRMM Multi-Satellite Precipitation Analysis daily product

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Summer-time synoptic-scale waves in