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Sample records for alligator rivers region

  1. Alligator Rivers Region

    International Nuclear Information System (INIS)

    1992-01-01

    An introduction to the Alligator Rivers Region is presented. It contains general information regarding the physiography, climate, hydrology and mining of the region. The Alligator Rivers Region is within an ancient basin, the Pine Creek Geosyncline, which has an area of approximately 66000 km 2 . The Geosyncline has a history of mineral exploitation dating back to 1865, during which time 16 metals have been extracted (silver, arsenic, gold, bismuth, cadmium, cobalt, copper, iron, manganese, molybdenum, lead, tin, tantalum, uranium, tungsten, zinc). Uranium exploration in the Pine Creek Geosyncline was stimulated by the discovery in 1949 of secondary uranium mineralisation near Rum June, 70 km south-east of Darwin. This was followed by a decade of intense exploration activity resulting in the discoveries of economic uranium ore bodies at Rum Jungle and in the upper reaches of the South Alligator River Valley. All the known major uranium deposits of the East Alligator River uranium field have been discovered since 1969. The present known resources of the Geosyncline are approximately 360 000 tonnes of contained U 3 O 8 . 2 refs., 2 figs., 1 tab

  2. Environmental protection in the Alligator Rivers Region

    International Nuclear Information System (INIS)

    Riley, G.

    1989-01-01

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

  3. The Federal Government and the Alligator Rivers Region

    International Nuclear Information System (INIS)

    BURTON, A.

    1989-01-01

    The administrative framework put in place by the Commonwealth and Northern Territory governments to monitor mining activities in the Alligator Rivers Region is presented. The key institutional element is the Coordinating Committee for the Alligator Rivers Region chaired and serviced by the Supervising Scientist and established through legislation

  4. Causes of environmental change in the Alligator Rivers region

    International Nuclear Information System (INIS)

    Skidmore, J.

    1990-01-01

    Covering some 28,000 square kilometres of the Northern Territory, the Alligator Rivers Region (ARR) includes the catchments of the East, South and West Alligator Rivers, and many small abandoned uranium mines. To introduce the problems of human impact on the ARR, the toxicologically significant aspects of the local environment were first examined, then the possible effects on it of mining and other human activities. It was found that the most deleterious impact on the region is not caused by mining but by human settlement, introduction of animals (notably the buffalo) and plants, the use of fire and tourism

  5. Alligator Rivers Regions Research Institute research report 1983-84

    International Nuclear Information System (INIS)

    1984-01-01

    The Institute undertakes and coordinates research required to ensure the protection of the environment in the Alligator Rivers Region from any consequences resulting from the mining and processing of uranium ore. Research projects outlined are in aquatic biology, terrestrial ecology, analytical chemistry, environmental radioactivity and geomorphology

  6. Dietary pathways through lizards of the Alligator Rivers Region

    International Nuclear Information System (INIS)

    James, C.D.; Morton, S.R.; Braithwaite, R.W.; Wombey, J.C.

    1984-07-01

    A broad survey of the diets of 46 species of terrestrial and arboreal lizards from the families Gekkonidae, Pygopodidae, Agamidae and Scincidae was carried out in the Alligator Rivers Region, and the diets of three of the species were examined in detail by monthly sampling near the Ranger uranium mine. The study shows that, in the event of contamination of the waterbodies, only two species of lizards face any risk of contamination through their food

  7. Plants of the Alligator Rivers Region, Northern Territory

    International Nuclear Information System (INIS)

    Cowie, I.D.; Finlayson, C.M.

    1986-01-01

    Published and unpublished lists of plants of the Alligator Rivers Region have been combined into a single, up-to-date check-list. The list has been designed to replace fragmented, regional listings with a single document suitable for use by both professional and amateur botanists. The list is ordered in the taxonomic sequence adopted for the Flora of Australia and includes 1346 species from 165 families. These are 1275 native and 71 alien species listed. Separate lists of rare species are given and discussed

  8. Plants of the Alligator Rivers Region, Northern Territory

    Energy Technology Data Exchange (ETDEWEB)

    Cowie, I D; Finlayson, C M

    1986-01-01

    Published and unpublished lists of plants of the Alligator Rivers Region have been combined into a single, up-to-date check-list. The list has been designed to replace fragmented, regional listings with a single document suitable for use by both professional and amateur botanists. The list is ordered in the taxonomic sequence adopted for the Flora of Australia and includes 1346 species from 165 families. These are 1275 native and 71 alien species listed. Separate lists of rare species are given and discussed.

  9. Environment Protection (Alligator Rivers Region) Act 1978, No.28

    International Nuclear Information System (INIS)

    1978-01-01

    The main object of this Act is to provide for the appointment of a Supervising Scientist responsible for supervising protection of the environment in the Alligator Rivers Region of the Northern Territory from the effects of uranium mining operations. His functions include advising the competent Minister on the effects of uranium mining operations on the environment and on standards, practices and procedures for its protection and restoration. The Act also sets up a Co-ordinating Committee responsible for programmes for research into the environmental effects of such mining operations and also keeping under review standards, practices and procedures for environmental protection in relation thereto. Finally the Act provides for the establishment of a Research Institute managed by the Supervising Scientist, to promote and assist in research as well as to collect information on the environmental effects of uranium mining operations. (NEA) [fr

  10. A limnological survey of the Alligator Rivers Region. 1. Diatoms (Bacillariophyceae) of the region

    International Nuclear Information System (INIS)

    Thomas, D.P.

    1983-08-01

    This study was undertaken as part of a study of the algae of the Alligator Rivers Region in general, and of the Magela Creek in particular, to support an investigation into the possible use of native algae as an indicator of any changes in water quality which might occur as a result of uranium mining and milling in the Region

  11. Environment Protection (Alligator Rivers Region) Amendment Act 1987 - No 17 of 1987

    International Nuclear Information System (INIS)

    1987-01-01

    This Act amends the Environment Protection (Alligator Rivers Region) Act 1978. The amendments mainly concern definition of general mining operations and specification of the functions of the Supervisory Scientist and the Research Institute in relation to general mining in an environment conservation zone (parts of the Alligator Rivers Region). The 1978 Act provided for the appointment of a Supervising Scientist responsible for supervising protection of the environment against the effects of uranium mining in the Region, and for the creation of a Research Institute under his management. (NEA) [fr

  12. Ecological studies on the freshwater fishes of the Alligator Rivers Region, Northern Territory

    International Nuclear Information System (INIS)

    Bishop, K.A.; Allen, S.A.; Pollard, D.A.; Cook, M.G.

    1986-01-01

    The tropical climate of the Alligator Rivers Region of the Northern Territory has a distinctive Wet-Dry cycle resulting in seasonal flows in the creeks and rivers of its catchments. The present study, begun during August 1978, aimed at developing an ecological monitoring system that would detect changes in freshwater fish communities brought about by recent uranium mining and processing in the lowlands of the region

  13. Supervising Scientist for the Alligator Rivers Region Annual Report 1996-1997

    International Nuclear Information System (INIS)

    1997-01-01

    One of the most significant developments during the year was the submission by Energy Resources of Australia Ltd of its Environmental Impact Statement for Jabiluka. The proposal is significantly different in technical detail from the Ranger and Nabarlek mines owing to the proposal to mine underground. Evaluation of the Environmental Performance of the uranium mines of the Alligator Rivers Region continued, with twice-yearly Environmental Performance Reviews (EPR) of Ranger and Nabarlek, and results reported to the Alligator Rivers Region Advisory Committee (ARRAC). Ongoing technical consultations took place through meetings of the Ranger Minesite Technical Committee. Issues relating to water disposal were addressed through the Ranger Water Management Working Group. Submissions were made regarding the Jabiluka Environmental Impact Assessment process and technical advice was provided to the Environmental Assessment Branch of Environment Australia during the assessment. The organisation's research program has reflected strategic directions set last year by the Alligator Rivers Region Technical Committee (ARRTC) concerning environmental impacts of mining. Key projects assess radiation exposure by members of the public as a result of uranium mining, the effectiveness of artificial wetlands in the treatment of mine waters, and the development of methods to assess the effectiveness of options for rehabilitation. Development of the research program into wetlands protection and management continued, including establishment of a coordinated monitoring program to measure and assess coastal change as a benchmark for monitoring effects of climate change in the Alligator Rivers Region (a key part of a national network). Other research activities included water quality research for the National River Health Program and revision of the National Water Quality Management Strategy, Water Quality Guidelines for Fresh and Marine Waters and conclusion of research projects in the Mount

  14. Alligator Rivers Region Research Institute: annual research summary 1989-1990

    International Nuclear Information System (INIS)

    1991-01-01

    The Alligator Rivers Region Research Institute (ARRRI) research activities are associated with an assessment of environmental effect of mining in the region. While emphasis on baseline research is now much reduced, some projects are still necessary because of significant changes in the Magela Creek system, because new areas of proposed mining have been identified (e.g. Coronation Hill) and because the emphasis now being placed on rehabilitation research requires a sound knowledge of the Region's flora. The ARRRI rehabilitation research program has concentrated on the Ranger mine site, principally because it is at a critical planning stage where detailed research information is required. With regard to the development of techniques, research at the Institute has led to the development of specific analytical methods or protocols that can be used in assessing environmental impact. 39 tabs., 42 figs

  15. Problems of communicating radiation doses to aboriginal members of the public in the Alligator Rivers Region

    International Nuclear Information System (INIS)

    McLaughlin, D.

    1985-01-01

    Since the early 1970s, Aboriginal people of the Alligator Rivers Region have had to come to grips with the effects of uranium mining at Nabarlek and Ranger. One element in their cost-benefit approach to mine operations has been the expectation that bush foods in the region will not be contaminated by the mining operations. Recent studies on radionuclide concentrations in freshwater mussels (Velesunio angasi) in the region have shown this species, and perhaps others, to be efficient accumulators of radium. Information concerning natural radium accumulation in mussels and accompanying health risk estimates have been conveyed to Aboriginal people of the area and such information transfer has not been without its problems. Application of the ALARA principle to environmental management of the effluent pathways needs to consider Aboriginal expectations

  16. Alligator Rivers analogue project

    International Nuclear Information System (INIS)

    Duerden, P.

    1990-01-01

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

  17. Diets and abundances of aquatic and semi-aquatic reptiles in the Alligator Rivers Region

    International Nuclear Information System (INIS)

    Shine, R.

    1986-01-01

    The mining and milling of uranium in the Alligator River Region in the Northern Territory has raised the possibility that heavy metals and radionuclides might escape into the aquatic system and be accumulated by the reptilian fauna. Aquatic and semi-aquatic reptiles are regularly eaten by Aboriginal people of the region, and data on diets and reproduction of these species, as well as on their dispersion and abundance, are essential before the possibility that reptiles might act as pathways for these contaminants to Aboriginals can be assessed. The objectives of this study were to provide quantitative data on the diets of filesnakes, sand goannas and water goannas, to provide information on seasonal changes in their abundance and distribution within the Magela Creek system; and to describe their reproductive cycles

  18. Ecological studies on the freshwater fishes of the Alligator Rivers region, Northern Territory

    International Nuclear Information System (INIS)

    Bishop, K.A.; Allen, S.A.; Pollard, D.A.; Cook, M.G.

    1990-01-01

    The tropical climate of the Alligator Rivers Region (ARR) has a distinctive wet-dry cycle , resulting in seasonal flows in the creeks and rivers of its catchments. The present study, begun in August 1978, was aimed at developing an ecological monitoring system that would detect any changes to the freshwater fish communities brought about by recent uranium mining and processing in the lowlands of the ARR. The focus of the synecological studies, was a description of spatial and temporal patterns in the community structure of the fish fauna. Interpretation of these patterns was made possible by the collection of detailed environmental data from the study sites. It was found that of the ARR seasonal changes in environmental conditions were so marked that they often obscured the effects of environmental gradients along a watercourse and differing environmental conditions characteristics of different types of waterbody. Hence it may not be entirely satisfactory to define environmental zones in these catchments based on overall environmental conditions through the whole seasonal cycle, because changes in any one such zone between seasons result in very marked changes in the fish communities of habitats in that zone. 34 refs., 22 tabs., 45 figs., 3 maps

  19. Geomorphological assessment of sites and impoundments for the long term containment of uranium mill tailings in the Alligator Rivers Region

    International Nuclear Information System (INIS)

    East, T.J.

    1986-01-01

    This paper presents a program of current and future research into those geomorphological processes likely to affect the long term containment of uranium mill tailings in the Alligator Rivers Region of the Northern Territory. Research is directed at three main areas: identification of geomorphic hazards at proposed impoundment sites; determination of erosion rates on impoundment slopes; and prediction of patterns of fluvial dispersal of released tailings. Each necessitates consideration of present and future geomorphic processes

  20. A database of radionuclide activity and metal concentrations for the Alligator Rivers Region uranium province.

    Science.gov (United States)

    Doering, Che; Bollhöfer, Andreas

    2016-10-01

    This paper presents a database of radionuclide activity and metal concentrations for the Alligator Rivers Region (ARR) uranium province in the Australian wet-dry tropics. The database contains 5060 sample records and 57,473 concentration values. The data are for animal, plant, soil, sediment and water samples collected by the Environmental Research Institute of the Supervising Scientist (ERISS) as part of its statutory role to undertake research and monitoring into the impacts of uranium mining on the environment of the ARR. Concentration values are provided in the database for 11 radionuclides ( 227 Ac, 40 K, 210 Pb, 210 Po, 226 Ra, 228 Ra, 228 Th, 230 Th, 232 Th, 234 U, 238 U) and 26 metals (Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Na, Ni, P, Pb, Rb, S, Sb, Se, Sr, Th, U, V, Zn). Potential uses of the database are discussed. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

  1. Environmental surveillance monitoring in the Alligator Rivers Region. Report for the six months period ending 30 September 1996

    International Nuclear Information System (INIS)

    1996-01-01

    This report outlines the activities of the Northern Territory Supervising Authorities in meeting their responsibilities for environmental management and surveillance, occupational safety, relating to uranium mining and environment protection in the Alligator Rivers Region. Environmental monitoring was carried out at the Nabarlek Mine, which site has now been rehabilitated and revegetated, and at Ranger, the only mine currently operating in the region. Other uranium projects such as Jabiluka and Koongarra have been delayed due to the former Commonwealth Government's 'three mines policy'. 4 tabs., 10 figs

  2. Case history of the discovery of the Jabiluka uranium deposits, East Alligator River region, Northern Territory of Australia

    International Nuclear Information System (INIS)

    Rowntree, J.C.; Mosher, D.V.

    1976-01-01

    Pancontinental Mining Limited acquired exploration rights over an area in the East Alligator River Region, Northern Territory, Australia, in 1970. Subsequently, Getty Oil Development Company Limited acquired a substantial minority interest in the property. The Jabiluka deposits were discovered during the course of exploration and are currently the largest of the four major uranium deposits in the East Alligator River Region. This region at present contains 24% of the western world's reasonably assured resources of uranium. The exploration techniques employed during primary and secondary exploration on the property between 1971 and 1975 and during the delineation of the Jabiluka deposits are discussed in detail. The case history illustrates the exploration philosophy which was successfully employed on the Jabiluka property. The philosophy encompasses the following points: The need for an assessment on the limits of airborne radiometric surveys; the necessity for detection and evaluation of point source anomalies; the necessity for exploration along extensions of favourable lithologies; and the desirability of modification of exploration techniques on different types of anomalies. Some aspects of this philosophy may be useful in exploration for similar stratabound uranium deposits in other areas. (author)

  3. Mining in the Alligator Rivers Region, northern Australia: Assessing potential and actual effects on ecosystem and human health

    International Nuclear Information System (INIS)

    Dam, R.A. van; Humphrey, C.L.; Martin, P.

    2002-01-01

    This paper presents an overview of issues related to surface water contamination arising from uranium mining activities in the Alligator Rivers Region (ARR) of northern Australia, and a program of research and monitoring that must assess the potential and actual effects on ecosystem and human health. The program of assessing effects on aquatic ecosystems involves a four-tiered approach including the derivation of local water quality guideline trigger values, direct toxicity assessment of mine waters prior to their release, creekside or in situ monitoring for early warning of adverse effects during mine water release, and longer-term monitoring of macroinvertebrate and fish communities. Bioaccumulation in aquatic biota is also assessed, and is an issue of importance not only to ecosystem health, but also to the health of local Aboriginal people. The aquatic animals they consume represent potential sources of radiological dose, and as a result, a major component of the program to assess potential effects on human health is the prediction of doses to Aboriginal people living downstream of mining activities. Acknowledging the assumptions and uncertainties, the calculation of concentration factors for local aquatic (and other) food sources allows the prediction of potential radiological exposure to people following hypothetical mine water releases. The approaches described form the basis of best-practice protocols that are relevant at both regional and national levels

  4. Land application of waste waters in the Alligator Rivers region, Northern Territory - environmental constraints on design and operation

    International Nuclear Information System (INIS)

    Kearns, A.

    1986-01-01

    The existing uranium mines in the Alligator River Region presently operate under a no release water management regime for water stored within the designated restricted release zones (RRZ). This water is of variable quality ranging from rainwater influenced by runoff from the mill sites and ore stockpiles to mill process water stored within the trailings repositories. There is a pressing need to reduce the volume of stored RRZ water at Nabarlek as a prerequisite to decommissioning. There is also a requirement at Ranger to rapidly reduce the volume of stored water in the mine pit at the end of the season to allow the mining of ore. Land application of RRZ water by spray irrigation has been investigated at both sites because it offers the benefits of applying chemical constituents in the wastewater within a clearly defined irrigation area. the environmental planning for the design of a land application system involves calculations of the chemical load in the wastewater and evaluation of the assimilative capacity of the soil-plant system. The monsoon climate, lateritic soil and fluctuating water table creates a unique set of environmental constraints and conditions in which to design and operate a successful land application system for the treatment of stored water at minesites within ecologically sensitive areas

  5. Geomorphological assessment of sites and impoundments for the long term containment of uranium mill tailings in the Alligator Rivers Region

    International Nuclear Information System (INIS)

    East, T.J.

    1985-01-01

    Current and future research into the geomorphological processes likely to affect the long term containment of uranium mill tailings in the Alligator Rivers Region is directed at three main areas: identification of geomorphic hazards at proposed impoundment sites; determination of erosion rates on impoundment slopes; and prediction of patterns of fluvial dispersal of released tailings. Each necessitates consideration of present and future geomorphic processes. Process rates during the next few thousand years might be predictable by extrapolation of contemporary and past (i.e. Holocene) climates, sea-levels and depositional environments, evidence for which is preserved in the sedimentary record. In current projects, the Late Quarternary stratigraphy of Magela Creek are examined to provide data for modelling of present and future sedimentological processes. Site stability evaluation entails recognition of present and future geomorphic hazards at impoundment sites, and includes fluvial and hillslope erosion, extreme flood events and mass movements. The life of a tailings impoundment is further determined by the intensity of erosional processes acting upon its slopes and their cover materials. A knowledge of present and future erosion rates will allow the optimisation of slope characteristics and materials in the impoundment design

  6. Characterization of mineral coatings associated with a Pleistocene-Holocene rock art style: The Northern Running Figures of the East Alligator River region, western Arnhem Land, Australia.

    Science.gov (United States)

    King, Penelope L; Troitzsch, Ulrike; Jones, Tristen

    2017-02-01

    This data article contains mineralogic and chemical data from mineral coatings associated with rock art from the East Alligator River region. The coatings were collected adjacent to a rock art style known as the "Northern Running Figures" for the purposes of radiocarbon dating (doi:10.1016/j.jasrep.2016.11.016; (T. Jones, V. Levchenko, P.L. King, U. Troitzsch, D. Wesley, 2017) [1]). This contribution includes raw and processed powder X-ray Diffraction data, Scanning Electron Microscopy energy dispersive spectroscopy data, and Fourier Transform infrared spectral data.

  7. Six-monthly report on surveillance of environmental monitoring in Alligator Rivers Region for the period 1 April-30 September 1988

    International Nuclear Information System (INIS)

    1988-01-01

    This report outlines the activities of Northern Territory Government authorities (Department of Mines and Energy (DME), Conservation Commission and Department of Health and Community Services (DHCS) in meeting their responsibilities for surveillance of environmental monitoring in the Alligator Rivers Region for the period 1 April to 30 September 1988. The responsibility for DME activities derives principally from the Mining Act, the Mines Safety Control Act, the Control of Waters Act and the Uranium Mining (Environment Control) Act, referred to in this report as the UMEC Act. The Land Conservation Unit (LCU) of the Conservation Commission and the Occupational and Environmental Health Branch of DHCS, furnish technical advice to the Alligator Rivers Region Unit of DME, which then collates the data for Authorizations, approvals and compliance reports. The responsibilities of the Conservation Commission derive from the Soil Conservation and Land Utilization Act. DHCS activities derive from, in addition to the relevant Mines Acts, the Silicosis and Tuberculosis (Mine Workers and Prospectors) Act, Radiation (Safety Control) Act and the Public Health Act

  8. Development of the Alligator Rivers uranium deposits

    International Nuclear Information System (INIS)

    Bath, L.J.; Farthing, J.W.; Warner, R.K.

    1980-01-01

    The Alligator Rivers Uranium Province in the Northern Territory of Australia has proven uranium deposits at Jabiluka, Ranger, Koongarra and Nabarlek which contain more than 80% of the country's low-cost reasonably assured uranium resources estimated to be 290,000 t U. Following the Government's decision in 1977 to proceed with the further development of Australia's uranium resources, the region is destined to become a major producer of U 3 O 8 for export. At the time of the decision provision was made for strict controls to protect the environment, the granting of Aboriginal land rights and the creation of a major national park. The paper describes the progress made to achieve these objectives. The open-cut mining methods to be used at Ranger, Koongarra and Nabarlek are described, as well as the underground mining operations proposed for Jabiluka. Each of the treatment plants will use the conventional acid leach, solvent extraction purification process for uranium recovery. The characteristics of the treatment operations are outlined. The water-management schemes, tailings disposal methods and procedures for environment protection are also discussed. The proposed initial production capacities of the operations are: Jabiluka 2540 (expanding to 7630 in the fifth year of production); Ranger 2540 (expanding to 5080 when commercially practicable); Koongarra 850; and Nabarlek 920 t U/a. Both Nabarlek and Ranger have been granted Government development approval and construction is proceeding at each site with the expectation that normal commercial production will commence towards the end of 1980 and 1981, respectively. Planning for the Jabiluka and Koongarra projects has reached an advanced stage; each are undergoing environmental procedures and will have to reach agreement with the Aboriginals on environmental and other matters before site work can commence. (author)

  9. The alligator rivers analogue project

    International Nuclear Information System (INIS)

    Duerden, P.

    1991-01-01

    The Koongarra uranium ore deposit in the Northern Territory of Australia is being studied to evaluate the processes and mechanisms involved in the hydrological/geochemical alteration of the primary uranium and model the formation of the secondary uranium mineralisation and the dispersion fan. A wide range of research is undertaken in the field and at laboratories in Australia, Japan, Sweden, the UK and the USA. The experimental and modelling tasks consider the original weathering of the region, the alteration of the host rock and primary uranium, groundwater flow and migration pathways, rock/groundwater interactions, such as adsorption desorption, nuclide transport and the relative distribution of the uranium/thorium radionuclides in the multi-phase system, and the continued development of the dispersion fan. The study of the in-situ production and mobility of long lived fission products eg Tc-99 and I-129 and transuranic nuclides such as Pu-239 is also possible. The methods used in collecting data for a repository are similar to those applied at Koongarra, hence, an analysis of the many different approaches taken may help evaluate and decrease the uncertainties of with field and laboratory measurements. (J.P.N.)

  10. Alligator Rivers Analogue Project. Final Report - Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Duerden, P [Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights, NSW (Australia); Lever, D A [AEA Technology, Harwell (United Kingdom); Sverjensky, D A [Johns Hopkins Univ., Baltimore, MD (United States); Townley, L R [Commonwealth Scientific and Industrial Research Organisation (CSIRO), Wembley, WA (Australia). Div. of Water Resources

    1992-07-01

    This summary report, which highlights the work and findings of the Alligator Rivers Analogue Project (ARAP) is one of a series of 16 volumes, listed below. Detailed descriptions and results are provided in Volumes 2 to 16. Full acknowledgment to individual contributions is provided in the individual reports, and in Appendix I of this report. The findings from the technical studies are discussed in the context of assessments of the long-term performance of geological repositories for radioactive wastes, which are being undertaken in many countries. They are also considered in an integrated 'Scenario Development' approach, aimed to understand the formation of the ore deposit. Despite their inherent uncertainties, the findings provide a basis for assessing the way in which radionuclides will migrate in environments with a variety of geologic settings and over a range of different geologic timescales. Thus, section 2 of this report discusses the concept of using uranium deposits as natural analogues and refers to a number of such studies, including those at the Koongarra deposit in the Alligator Rivers Region of the Northern Territory of Australia. Section 3 reviews early scientific work in the Alligator Rivers Region and summarises the results of the analogue studies undertaken between 1981 and 1987 that were funded by the US Nuclear Regulatory Commission (USNRC) and the UK Department of the Environment (UKDoE). Section 4 describes the objectives of ARAP and the manner in which the study was conducted and provides a general outline of the project and a summary of the findings. A general description of the Koongarra ore deposit, the focus of ARAP, is provided in Section 5, with Sections 6-13 providing summaries of the work carried out to characterise the site in detail and provide data for modelling. Sections 14-18 discuss how this data was used in modelling and how the results may be applied for performance assessment studies. Finally, Section 19 considers the

  11. Alligator Rivers Analogue Project. Final Report - Volume 1

    International Nuclear Information System (INIS)

    Duerden, P.; Lever, D.A.; Sverjensky, D.A.; Townley, L.R.

    1992-01-01

    This summary report, which highlights the work and findings of the Alligator Rivers Analogue Project (ARAP) is one of a series of 16 volumes, listed below. Detailed descriptions and results are provided in Volumes 2 to 16. Full acknowledgment to individual contributions is provided in the individual reports, and in Appendix I of this report. The findings from the technical studies are discussed in the context of assessments of the long-term performance of geological repositories for radioactive wastes, which are being undertaken in many countries. They are also considered in an integrated 'Scenario Development' approach, aimed to understand the formation of the ore deposit. Despite their inherent uncertainties, the findings provide a basis for assessing the way in which radionuclides will migrate in environments with a variety of geologic settings and over a range of different geologic timescales. Thus, section 2 of this report discusses the concept of using uranium deposits as natural analogues and refers to a number of such studies, including those at the Koongarra deposit in the Alligator Rivers Region of the Northern Territory of Australia. Section 3 reviews early scientific work in the Alligator Rivers Region and summarises the results of the analogue studies undertaken between 1981 and 1987 that were funded by the US Nuclear Regulatory Commission (USNRC) and the UK Department of the Environment (UKDoE). Section 4 describes the objectives of ARAP and the manner in which the study was conducted and provides a general outline of the project and a summary of the findings. A general description of the Koongarra ore deposit, the focus of ARAP, is provided in Section 5, with Sections 6-13 providing summaries of the work carried out to characterise the site in detail and provide data for modelling. Sections 14-18 discuss how this data was used in modelling and how the results may be applied for performance assessment studies. Finally, Section 19 considers the

  12. Radionuclide migration around uranium ore bodies in the Alligator Rivers region of the Northern Territory, Australia - analogue of radioactive waste repositories

    International Nuclear Information System (INIS)

    Airey, P.L.; Roman, D.; Golian, C.; Short, S.; Nightingale, T.; Lowson, R.T.; Davey, B.G.; Gray, D.

    1984-01-01

    Appropriate geochemical analogues may be used to reduce the uncertainties in predicting the long-term transport of actinides, radium and fission products from laboratory adsorption and hydrological data. In this study the migration of uranium series nuclides within, and down-gradient of ore bodies in the Alligator Rivers uranium province of the Northern Territory of Australia is described. A mathematical framework was developed to permit calculation of the rate of leaching or deposition of uranium and radium between defined zones of the ore bodies, and the rate of loss of the nuclides due to groundwater transport and surface erosion. A detailed study was made of the distribution of uranium, thorium and radium isotopes within various minerals comprising the weathered ore assemblage. Uranium and thorium concentrate principally in the iron minerals and radium in the clay-quartz phases. Substantial disequilibria are observed, which are attributed to a combination of α-recoil and chemical effects. Evidence of the relative lability of iron phases is presented. The transport of uranium series nuclides in groundwater intersecting the deposits was investigated. Down-gradient of the Ranger One deposit, the maximum retardation factor of uranium is 250. The role of colloids in groundwater transport is being studied. Uranium is transported principally in solution. There appears to be an equilibrium between solute and articulate uranium

  13. Alligator Rivers Analogue project. Hydrogeological modelling. Final Report - Volume 6

    International Nuclear Information System (INIS)

    Townley, L.R.; Trefry, M.G.; Barr, A.D.; Braumiller, S.

    1992-01-01

    This volume describes hydrogeological modelling carried out as part of the Alligator Rivers Analogue Project. Hydrogeology has played a key integrating role in the Project, largely because water movement is believed to have controlled the evolution of the Koongarra uranium Orebody and therefore affects field observations of all types at all scales. Aquifer testing described uses the concept of transmissivity in its interpretation of aquifer response to pumping. The concept of an aquifer, a layer transmitting significant quantities of water in a mainly horizontal direction, seems hard to accept in an environment as heterogeneous as that at Koongarra. But modelling of aquifers both in one dimension and two dimensionally in plan has contributed significantly to our understanding of the site. A one-dimensional model with three layers (often described as a quasi two dimensional model) was applied to flow between the Fault and Koongarra Creek. Being a transient model, this model was able to show that reverse flows can indeed occur back towards the Fault, but only if there is distributed recharge over the orebody as well as a mechanism for the Fault, or a region near the Fault, to remove water from the simulated cross-section. The model also showed clearly that the response of the three-layered system, consisting of a highly weathered zone, a fractured transmissive zone and a less conductive lower schist zone, is governed mainly by the transmissivity and storage coefficient of the middle layer. The storage coefficient of the higher layer has little effect. A two-dimensional model in plan used a description of anisotropy to show that reverse flows can also occur even without a conducting Fault. Modelling of a three-dimensional region using discrete fractures showed that it is certainly possible to simulate systems like that observed at Koongarra, but that large amounts of data are probably needed to obtain realistic descriptions of the fracture networks. Inverse modelling

  14. Alligator Rivers Analogue project. Hydrogeological modelling. Final Report - Volume 6

    Energy Technology Data Exchange (ETDEWEB)

    Townley, L R; Trefry, M G; Barr, A D [CSIRO Div of Water Resources, PO Wembley, WA (Australia); Braumiller, S [Univ of Arizona, Tucson, AZ (United States). Dept of Hydrology and Water Resources; Kawanishi, M [Central Research Institute of Electric Power Industry, Abiko-Shi, Chiba-Ken (Japan); and others

    1993-12-31

    This volume describes hydrogeological modelling carried out as part of the Alligator Rivers Analogue Project. Hydrogeology has played a key integrating role in the Project, largely because water movement is believed to have controlled the evolution of the Koongarra uranium Orebody and therefore affects field observations of all types at all scales. Aquifer testing described uses the concept of transmissivity in its interpretation of aquifer response to pumping. The concept of an aquifer, a layer transmitting significant quantities of water in a mainly horizontal direction, seems hard to accept in an environment as heterogeneous as that at Koongarra. But modelling of aquifers both in one dimension and two dimensionally in plan has contributed significantly to our understanding of the site. A one-dimensional model with three layers (often described as a quasi two dimensional model) was applied to flow between the Fault and Koongarra Creek. Being a transient model, this model was able to show that reverse flows can indeed occur back towards the Fault, but only if there is distributed recharge over the orebody as well as a mechanism for the Fault, or a region near the Fault, to remove water from the simulated cross-section. The model also showed clearly that the response of the three-layered system, consisting of a highly weathered zone, a fractured transmissive zone and a less conductive lower schist zone, is governed mainly by the transmissivity and storage coefficient of the middle layer. The storage coefficient of the higher layer has little effect. A two-dimensional model in plan used a description of anisotropy to show that reverse flows can also occur even without a conducting Fault. Modelling of a three-dimensional region using discrete fractures showed that it is certainly possible to simulate systems like that observed at Koongarra, but that large amounts of data are probably needed to obtain realistic descriptions of the fracture networks. Inverse modelling

  15. Alligator rivers analogue project. Final report; volume 1; summary of findings

    International Nuclear Information System (INIS)

    Duerden, P.; Lever, D.A.; Sverjensky, D.A.; Townley, L.R.

    1992-01-01

    The Koongarra uranium ore deposit is located in the Alligator Rivers Region of the Northern Territory of Australia. Many of the processes that have controlled the development of this natural system are relevant to the performance assessment of radioactive waste repositories. An agreement was reached in 1987 by a number of agencies concerned with radioactive waste disposal to set up the International Alligator Rivers Analogue Project (ARAP) to study relevant aspects of the hydrological and geochemical evolution of the site. The Project ran for five years. The aims of the study were: to contribute to the production of reliable and realistic models for radionuclide migration within geological environments relevant to the assessment of the safety of radioactive waste repositories; to develop methods of validation of models using a combination of laboratory and field data associated with the Koongarra uranium deposit; and to encourage maximum interaction between modellers and experimentalists in achieving these objectives. It was anticipated that the substantial databases generated in the field and laboratory studies would then be used to develop and test geochemical and radionuclide transport models. The findings from the technical studies are discussed in the context of assessments of the long-term performance of geological repositories for radioactive wastes, which are being undertaken in many countries. They are also considered in an integrated 'Scenario Development' approach, aimed to understand the formation of the ore deposit. Despite their inherent uncertainties, the findings provide a basis for assessing the way in which radionuclides will migrate in environments with a variety of geologic settings and over a range of different geologic timescales. This summary report, which highlights the work and findings of the Alligator Rivers Analogue Project is one of a series of 16 volumes

  16. The influence of regional hydrology on nesting behavior and nest fate of the American alligator

    Science.gov (United States)

    Ugarte, Cristina A.; Bass, Oron L.; Nuttle, William; Mazzotti, Frank J.; Rice, Kenneth G.; Fujisaki, Ikuko; Whelan, Kevin R.T.

    2013-01-01

    Hydrologic conditions are critical to the nesting behavior and reproductive success of crocodilians. In South Florida, USA, growing human settlement has led to extensive surface water management and modification of historical water flows in the wetlands, which have affected regional nesting of the American alligator (Alligator mississippiensis). Although both natural and anthropogenic factors are considered to determine hydrologic conditions, the aspects of hydrological patterns that affect alligator nest effort, flooding (partial and complete), and failure (no hatchling) are unclear. We deconstructed annual hydrological patterns using harmonic models that estimated hydrological matrices including mean, amplitude, timing of peak, and periodicity of surface water depth and discharge and examined their effects on alligator nesting using survey data from Shark Slough, Everglades National Park, from 1985 to 2005. Nest effort increased in years with higher mean and lesser periodicity of water depth. A greater proportion of nests were flooded and failed when peak discharge occurred earlier in the year. Also, nest flooding rates were greater in years with greater periodicity of water depth, and nest failure rate was greater when mean discharge was higher. This study guides future water management decisions to mitigate negative impacts on reproduction of alligators and provides wildlife managers with a tool for assessing and modifying annual water management plans to conserve crocodilians and other wetland species.

  17. Potential impact of Dare County landfills on Alligator River National Wildlife Refuge

    Science.gov (United States)

    Winger, P.V.; Lasier, P.J.; Augspurger, T.

    2005-01-01

    Runoff of leachate from East Lake and Dare County Construction and Demolition Debris landfills has the potential to impact wildlife resources at Alligator River National Wildlife Refuge, Dare and Hyde Counties, North Carolina. Sediment quality of samples collected in August 2000 at 14 locations down-gradient from the landfills was assessed by measuring metal and organic contaminants in the sediments, chronic toxicity of solid-phase sediment (28-d static-renewal exposures; survival and growth as test endpoints) and acute toxicity of sediment porewater (96-h static exposures) to Hyalella azteca (Crustacea: Amphipoda). In addition, contaminant bioaccumulation from 4 sediments was determined using 28-d exposures of Lumbriculus variegatus (freshwater oligochaete). Although survival was not impaired, length of H. azteca was significantly reduced in sediments from 5 locations. Pore water from 4 locations was acutely toxic to H. azteca. Metals and a few polycyclic aromatic hydrocarbons (PAHs) were bioaccumulated by L. variegatus from the sediments. Several metals and PAHs exceeded sediment quality guidelines, and metals in porewater from several sites exceeded water quality criteria for the protection of aquatic wildlife. Runoff of leachate from the landfills has reduced sediment quality and has the potential to adversely affect wildlife resources at Alligator River National Wildlife Refuge.

  18. Alligator Rivers Analogue project. Geomorphology and paleoclimatic history

    International Nuclear Information System (INIS)

    Wyrwoll, K.H.

    1992-01-01

    The aim of this volume is to discuss the likely influence of geomorphological and palaeoclimatic controls on the development of the secondary dispersion fan at Koongarra. For the Koongarra area the Phanerozoic was a time of tectonic stability and predominantly subaerial denudation. The structural geology of the region facilitated the erosion of the Kombolgie Formation, setting in train the development of Koongarra Valley. With the removal of the Kombolgie cover the surface of the Cahill Formation could then be eroded. The geochemical controls on the development of the secondary dispersion fan require the orebody to be located in an oxidising weathering environment. Under the present weathering regimes it seems that this implies that the orebody is located at a depth of less than 30 m. From estimates of the present regional denudation rates of the area and wider geomorphological considerations, it is concluded that the top of the orebody would have reached such a depth at some time in the last 1-6 million years. The climates of the Late Quaternary provide some guide to Pleistocene climatic events. The most intense aridity coincided with times of global glacial maxima. There is also evidence that in the Late Cenozoic there were times of elevated rates of chemical weathering. However, the timing, nature and duration of such events is unclear. 171 refs., 4 tabs., 35 refs

  19. The Alligator rivers natural analogue - Modelling of uranium and thorium migration in the weathered zone at Koongarra

    International Nuclear Information System (INIS)

    Skagius, K.; Lindgren, M.; Boghammar, A.; Brandberg, F.; Pers, K.; Widen, H.

    1993-08-01

    The Koongarra Uranium Deposit in the Alligator Rivers Region in the Northern Territory of Australia is a natural analogue being investigated with the aim to contribute to the understanding of the scientific basis for the long term prediction of radionuclide migration within geological environments relevant to radioactive waste repositories. The dispersion of uranium and decay products in the weathered zone has been modelled with a simple advection-dispersion-reversible sorption model and with a model extended to also consider α-recoil and transfer of radionuclides between different mineral phases of the rock. The modelling work was carried out in several iterations, each including a review of available laboratory and field data, selection of the system to be modelled and suitable model, and a comparison of modelling results with field observations. Uranium concentrations in bulk rock calculated with the simple advection-dispersion- reversible sorption model were in fair agreement with observed data using parameter values within ranges recommended based on independent interpretations. The advection-dispersion-reversible sorption model is a large simplification of the system among other things because the partitioning of radionuclides between water and solid phase is described with a sorption equilibrium term only. Although the results from this study not are enough to validate simple performance assessment models in a strict sense, it has been shown that even simple models are able to describe the present day distribution of uranium in the weathered zone at Koongarra. 23 refs, 61 figs

  20. The Alligator rivers natural analogue - Modelling of uranium and thorium migration in the weathered zone at Koongarra

    Energy Technology Data Exchange (ETDEWEB)

    Skagius, K; Lindgren, M; Boghammar, A; Brandberg, F; Pers, K; Widen, H [Kemakta, Stockholm (Sweden)

    1993-08-01

    The Koongarra Uranium Deposit in the Alligator Rivers Region in the Northern Territory of Australia is a natural analogue being investigated with the aim to contribute to the understanding of the scientific basis for the long term prediction of radionuclide migration within geological environments relevant to radioactive waste repositories. The dispersion of uranium and decay products in the weathered zone has been modelled with a simple advection-dispersion-reversible sorption model and with a model extended to also consider {alpha}-recoil and transfer of radionuclides between different mineral phases of the rock. The modelling work was carried out in several iterations, each including a review of available laboratory and field data, selection of the system to be modelled and suitable model, and a comparison of modelling results with field observations. Uranium concentrations in bulk rock calculated with the simple advection-dispersion- reversible sorption model were in fair agreement with observed data using parameter values within ranges recommended based on independent interpretations. The advection-dispersion-reversible sorption model is a large simplification of the system among other things because the partitioning of radionuclides between water and solid phase is described with a sorption equilibrium term only. Although the results from this study not are enough to validate simple performance assessment models in a strict sense, it has been shown that even simple models are able to describe the present day distribution of uranium in the weathered zone at Koongarra. 23 refs, 61 figs.

  1. The International intraval project. Phase 1 case 8: The Alligator rivers natural analogue

    International Nuclear Information System (INIS)

    Duerden, P.

    1992-01-01

    INTRAVAL is an international coordinated research program for predicting the potential radionuclide migration in the geosphere with the use of mathematical models. Such models are used to help assess the long-term safety of radioactive waste disposal systems. The objective of the Alligator Rivers Analogue Project (ARAP) is to identify and study long-term processes that have been significant in the development of the uranium dispersion zone at the Koongarra uranium ore deposit in the Northern Territory of Australia. This report includes a description of the site geology and gives an outline of the experimental programs, which are aimed to study the hydrogeology and geochemistry of the system, and the distribution of uranium and its daughter radionuclides in the rock strata. The extensive databases that have resulted from these studies have been used to develop and test hydrological, geochemical and transport models. A good basis has been established for modelling the transport of radionuclides in the porous, weathered zone of the Koongarra uranium deposit and its surroundings. A number of preliminary transport, hydrology and geochemical modelling reports are given, with the Koongarra databases also being used to test a Performance Assessment model. The possible application of scenario development procedures to the Koongarra site is discussed. 106 refs., 67 figs., 28 tabs

  2. The influence of floodplain geomorphology and hydrologic connectivity on alligator gar (Atractosteus spatula) habitat along the embanked floodplain of the Lower Mississippi River

    Science.gov (United States)

    van der Most, Merel; Hudson, Paul F.

    2018-02-01

    The floodplain geomorphology of large lowland rivers is intricately related to aquatic ecosystems dependent upon flood pulse dynamics. The alligator gar (Atractosteus spatula) is native to the Lower Mississippi River and dependent upon floodplain backwater areas for spawning. In this study we utilize a geospatial approach to develop a habitat suitability index for alligator gar that explicitly considers hydrologic connectivity and the floodplain geomorphology along a frequently inundated segment of the Lower Mississippi River. The data sets include Landsat imagery, a high-resolution LiDAR digital elevation model (DEM), National Hydrography Dataset (NHD), and hydrologic and geomorphic data. A habitat suitability index is created based on the extent and frequency of inundation, water depth, temperature, and vegetation. A comparison between the remote sensing approach and the NHD revealed substantial differences in the area and location of water bodies available for alligator gar spawning. The final habitat suitability index indicates that a modest proportion (19%) of the overall embanked floodplain is available for alligator gar spawning. Opportunities exist for management efforts to utilize engineered and natural geomorphic features to facilitate hydrologic connectivity at flow levels below flood stage that would expand the habitat of alligator gar across the floodplain. The study results have direct implications regarding environmental restoration of the Lower Mississippi, an iconic example of an embanked meandering river floodplain.

  3. Evaluating potential effects of widening US 64 on the black bear population of Alligator River National Wildlife Refuge, Dare County, North Carolina.

    Science.gov (United States)

    2011-12-21

    This report summarizes research conducted along US Highway 64 (US 64) and US Highway 264 (US 264) in Alligator : River National Wildlife Refuge (ARNWR), Dare County, NC regarding the proposed expansion of US 64. The study site : included the areas ad...

  4. INTRAVAL phase 2, test case 8. Alligator Rivers Natural Analogue - Modelling of uranium transport in the weathered zone at Koongarra (Australia). Progress report

    NARCIS (Netherlands)

    van der Weerd H; Hassanizadeh SM; Richardson-van der Poel MA; LBG

    1993-01-01

    A study of uranium transport in the Koongarra site of Alligator Rivers Uranium deposit (Australia) is carried out. The analysis of the solid phase uranium concentration measured at various depths provides a useful picture of the dispersion process. Results of this analysis seem to support the

  5. Alligator Rivers Analogue project. Hydrogeological field studies. Final Report - Volume 5

    Energy Technology Data Exchange (ETDEWEB)

    Davis, S N [Univ of Arizona, Tucson, Arizona (United States). Dept of Hydrology and Water Resources; Marley, R D [D.B. Stephens and Associates Inc., Albuquerque, NM (United States); Norris, J R [Hydro Geo Chem Inc., Tucson, Arizona (United States)

    1993-12-31

    The hydrogeology of the Koongarra site was interpreted primarily from long-term hydrographs, water-level maps, water injection tests, aquifer pumping tests, logs of boreholes, and chemical analyses of groundwater samples. Data have been collected over a 21-year period starting with test-drilling in 1970. The first intensive period of hydrogeologic investigations was from 1978 through 1981 and was related to anticipated exploitation of uranium ore at Koongarra. The second period was from 1986 through 1991 and was related to the international Alligator Rivers Analogue Project under the direction of the Australian Nuclear Science and Technology Organisation. The conclusion which can be drawn from the chemical data is that water moving out of the No. 1 ore deposit is diluted rapidly with recharge from the surface as it migrates down the hydraulic gradient. Most of the groundwater outside of the ore deposit does not originate from the ore deposit, and flow models which assume unmodified stream tubes extending out of the ore deposit in a downgradient direction do not reflect the true system. Water in the ore deposit itself, must come from slow upward seepage through the fault zone. Owing to the fact that this water must be at least hundreds of years old, observed fluctuations of water levels in the deposit must reflect pressure head variations induced by seasonal recharge to the overlying surficial materials. Water level fluctuations do not signify a yearly displacement of water deep in the system. Water in the deeper part of the ore must be almost static compared to obvious rapid groundwater circulation in the area around PH88. Small changes in pH, temperature and specific electrical conductivity during aquifer tests indicate a complex hydraulic system which has a variable response to pumping as a function of time. Low concentration in tritium and Carbon-14 together with high concentrations of dissolved helium in the groundwaters all suggested strongly that semi static

  6. Alligator Rivers Analogue project. Hydrogeological field studies. Final Report - Volume 5

    Energy Technology Data Exchange (ETDEWEB)

    Davis, S.N. [Univ of Arizona, Tucson, Arizona (United States). Dept of Hydrology and Water Resources; Marley, R.D. [D.B. Stephens and Associates Inc., Albuquerque, NM (United States); Norris, J.R. [Hydro Geo Chem Inc., Tucson, Arizona (United States)

    1992-12-31

    The hydrogeology of the Koongarra site was interpreted primarily from long-term hydrographs, water-level maps, water injection tests, aquifer pumping tests, logs of boreholes, and chemical analyses of groundwater samples. Data have been collected over a 21-year period starting with test-drilling in 1970. The first intensive period of hydrogeologic investigations was from 1978 through 1981 and was related to anticipated exploitation of uranium ore at Koongarra. The second period was from 1986 through 1991 and was related to the international Alligator Rivers Analogue Project under the direction of the Australian Nuclear Science and Technology Organisation. The conclusion which can be drawn from the chemical data is that water moving out of the No. 1 ore deposit is diluted rapidly with recharge from the surface as it migrates down the hydraulic gradient. Most of the groundwater outside of the ore deposit does not originate from the ore deposit, and flow models which assume unmodified stream tubes extending out of the ore deposit in a downgradient direction do not reflect the true system. Water in the ore deposit itself, must come from slow upward seepage through the fault zone. Owing to the fact that this water must be at least hundreds of years old, observed fluctuations of water levels in the deposit must reflect pressure head variations induced by seasonal recharge to the overlying surficial materials. Water level fluctuations do not signify a yearly displacement of water deep in the system. Water in the deeper part of the ore must be almost static compared to obvious rapid groundwater circulation in the area around PH88. Small changes in pH, temperature and specific electrical conductivity during aquifer tests indicate a complex hydraulic system which has a variable response to pumping as a function of time. Low concentration in tritium and Carbon-14 together with high concentrations of dissolved helium in the groundwaters all suggested strongly that semi static

  7. A stream sediment orientation programme for Uranium in the Alligator River Province, Northern Territory, Australia

    International Nuclear Information System (INIS)

    Gingrich, J.E.; Foy, M.F.

    1977-01-01

    Sediments samples were collected from streams draining the Koongarra uranium deposit and the small uranium mines in the South Alligator Valley. Determinations for U, Cu and Pb on various size fractions taken from each of these samples indicated that the best results were obtained for U from the minus 200-mesh fraction, but the train from the Koongarra ore deposit was very short. Cu and Pb were not found to be very useful as indicator elements for U. Alpha-track films were used to determine the Rn content of each sample and the ratio of alpha-track film reading to U content was found to define anomalous drainage areas around the mineralization in the Koongarra area. The areas so defined were of sufficient magnitude to be defined in a reconnaissance stream sediment programme

  8. Uranium mineralization in the Rum Jungle-Alligator Rivers Province, Northern Territory, Australia

    International Nuclear Information System (INIS)

    Dodson, R.G.; Needham, R.S.; Wilkes, P.G.; Page, R.W.; Smart, P.G.; Watchman, A.L.

    1974-01-01

    Renewed interest in uranium exploration in northern Australia in the late 1960s led to the discovery of one of the most important uranium fields in the world. To obtain an understanding of the geological setting of the uranium deposits, and to provide guidelines for future exploration, the Bureau of Mineral Resources (BMR) undertook an investigation which included semi-detailed mapping, aided by geophysical surveys, isotopic dating, and stratigraphic drilling. From the results so far obtained and from the important data made available by mining companies engaged in exploration in the region, a pattern of uranium mineralization can be recognized, particularly in relation to the Lower Proterozoic sedimentation of the region. (author)

  9. Revised stratigraphic nomenclature and correlation of early proterozoic rocks of the Darwin - Katherine region, Northern Territory

    International Nuclear Information System (INIS)

    Needham, R.S.; Stuart-Smith, P.G.

    1984-01-01

    New stratigraphic names and correlations are given for parts of the Early Proterozoic Pine Creek Geosyncline metasedimentary sequence and overlying felsic volcanics of the Darwin-Katherine region. They have significant implications for the stratigraphic distribution of uranium mineralisation in the Rum Jungle, Alligator Rivers and South Alligator Valley uranium fields

  10. Sedimentation of the basal Kombolgie Formation (Upper Precambrian-Carpentarian) Northern Territory, Australia: possible significance in the genesis of the underlying Alligator Rivers unconformity-type uranium deposits

    International Nuclear Information System (INIS)

    Ojakangas, R.W.

    1979-10-01

    The 1400 to 1500 My old Kombolgie Formation of the MacArthur Basin of the Northern Territory overlies or has overlain unconformity-type uranium deposits including Jabiluka, Ranger, Koongarra, Nabarlek and the small deposits of the South Alligator River Valley. A brief study of the basal portion of the formation showed it to consist entirely of mature conglomerates and quartzose sandstones. Analysis of the bedding types (planar cross beds, trough cross beds and parallel beds) and other sedimentary structures (mainly ripple marks and parting lineation) fit a braided alluvial plain model. A paleocurrent study utilizing about 400 measurements from nine localities located along the westward-facing 250 kilometer-long erosional escarpment of the Arnhem Land Plateau showed the dominant paleocurrent trend to be from west and northwest towards the east and southeast, with local divergence. The data and interpretation presented are relevant to the supergene model of uranium deposition at the unconformity, for they add to the suggestion that additional uranium deposits similar to Jabiluka Two may underlie the Kombolgie Formation eastward from the present escarpment

  11. Biology and early development of eight fish species from the Alligator Rivers Region

    International Nuclear Information System (INIS)

    Ivantsoff, W.; Crowley, L.E.L.M.; Howe, E.; Semple, G.

    1988-01-01

    The following fish were studied: Melanotaenia nigrans, Melanotaenia splendida australis, Melanotaenia splendida inornata, Pseudomugil gertrudae, Pseudomugil tenellus, Craterocephalus nov. sp., Craterocephalus stercusmuscarum stercusmuscarum, and Ambassis macleavi. Coloration, other specific attributes, sexual dichromatism and dimorphism were recorded whenever possible so that the sexes could be easily recognised. Mating and other behaviour patterns were noted to facilitate recognition of breeding pairs. Spawning patterns and occurrence of cannibalism were recorded, as was the effect of the presence of more than one breeding pair in a tank. Egg numbers at each spawning were recorded and the main breeding season for each of the species was determined. No single stimulus to spawning could be determined. Spawning appeared to be sporadic but continuous throughout the year, with a peak during late spring/early summer. Detailed records of embryonic development were kept for all species except Ambassis macleayi. Time of development to hatching, at constant temperature, was recorded. Larval development of rainbow-fishes was recorded in detail and times to particular developmental stages noted and compared. For other species, the times to particular developmental stages were recorded and representative larval stages described and drawn. General recommendations are made in regard to the requirements to breed and maintain fish, the numbers that can be produced for further study and the constraints that may be present when working with selected fish. 46 refs., 18 figs., 16 tabs

  12. Fish communities in sandy pool of Magela Creek, Alligator Rivers Region

    International Nuclear Information System (INIS)

    Woodland, D.J.; Ward, P.J.

    1992-01-01

    Physico-chemical conditions, changes in fish communities and characteristics of species populations of eight permanent sandy pools along Magela Creek during the 1981 Dry season are described. Causes of mortality in each species, especially Craterocephalus marianae, were investigated. It is emphasised that in using baseline data to assess the impact of mining and animal communities, it may sometimes be difficult to differentiate natural mortality from mortality resulting from pollution. The aim of this study was to distinguish the most important environmental factors responsible for fish mortality. The study indicates that the mortality was low (<50% of the original population) in most pools. In populations that did suffer high mortality, anoxic conditions may have been an important cause. 67 refs., 36 tabs., 21 figs., ills

  13. Radium concentration factors in passionfruit (Passiflora foetida) from the Alligator Rivers Region, Northern Territory, Australia

    International Nuclear Information System (INIS)

    Medley, Peter; Bollhöfer, Andreas; Parry, David; Martin, Paul

    2013-01-01

    In this study, uptake of Ra from soil into the edible fruit of the wild passionfruit species Passiflora foetida was investigated, using selective extraction from the soil samples. A wide range of environmental exposure conditions were represented by the locations that were sampled, including both natural soils, and soils influenced by past and present uranium mining activities. The bioavailable 226 Ra fraction in soils was found to be a better predictor of 226 Ra fruit activity concentrations than the total soil activity concentration, or any of the other fractions studied. Concentration Factors (CFs) derived using the bioavailable fraction varied by only a factor of 7 between different locations, whereas CFs derived using other fractions and total soil varied by up to two orders of magnitude. CFs were highest for those soils containing the lowest concentrations of Mg, Ca and Ba, and approached a saturation value at higher soil concentrations. This finding suggests that group II elements influence radium uptake, most likely the result of increased pressure on the plant to take up essential nutrient group II elements from soil with the lower concentrations, with Ra being taken up as an analogue element. It is also possible that at higher concentrations of bioavailable Ca and Mg in the soil, these ions will outcompete Ra for adsorption sites in the soil and/or on the root surfaces. The study also shows that 228 Ra can potentially be a significant contributor to ingestion doses and should also be considered when assessing committed effective doses from the ingestion of fruits. -- Highlights: • Fruit and soil samples were taken from wild growing native passionfruit plants. • The sampling locations were on natural and U mining impacted sites. • Sequential extraction of the soil was undertaken. • Radium-226, radium-228 and other key elements were measured. • Concentration factors show the lowest variability in the bioavailable fraction

  14. Environmental impact of the Ranger uranium mine, Alligator Rivers Region, Northern Territory, Australia

    International Nuclear Information System (INIS)

    Johnston, A.; Needham, S.

    2002-01-01

    Stringent environmental controls have been applied to the Ranger mine, in the Northern Territory of Australia, because of its location in an area of outstanding natural and cultural values. The adjacent Kakadu National Park contains a wild and extensive biodiversity, striking landscapes, ancient Aboriginal rock art and a living Aboriginal culture. A special regime of biological, radiological and chemical monitoring has been applied to protect the environment and detect even very low intensity impacts. The results from this regime demonstrate to the government and general public that the high conservation values of the national park around the mine are being properly protected. This paper describes the techniques used to measure environmental impact at Ranger, and summarizes the results of over 20 years of monitoring. The overwhelming conclusion is that a very high standard of environmental protection has been achieved. (author)

  15. Biology and early development of eight fish species from the Alligator Rivers Region. Technical memorandum 22

    Energy Technology Data Exchange (ETDEWEB)

    Ivantsoff, W; Crowley, L E.L.M.; Howe, E; Semple, G

    1988-01-01

    The following fish were studied: Melanotaenia nigrans, Melanotaenia splendida australis, Melanotaenia splendida inornata, Pseudomugil gertrudae, Pseudomugil tenellus, Craterocephalus nov. sp., Craterocephalus stercusmuscarum stercusmuscarum, and Ambassis macleavi. Coloration, other specific attributes, sexual dichromatism and dimorphism were recorded whenever possible so that the sexes could be easily recognised. Mating and other behaviour patterns were noted to facilitate recognition of breeding pairs. Spawning patterns and occurrence of cannibalism were recorded, as was the effect of the presence of more than one breeding pair in a tank. Egg numbers at each spawning were recorded and the main breeding season for each of the species was determined. No single stimulus to spawning could be determined. Spawning appeared to be sporadic but continuous throughout the year, with a peak during late spring/early summer. Detailed records of embryonic development were kept for all species except Ambassis macleayi. Time of development to hatching, at constant temperature, was recorded. Larval development of rainbow-fishes was recorded in detail and times to particular developmental stages noted and compared. For other species, the times to particular developmental stages were recorded and representative larval stages described and drawn. General recommendations are made in regard to the requirements to breed and maintain fish, the numbers that can be produced for further study and the constraints that may be present when working with selected fish. 46 refs., 18 figs., 16 tabs.

  16. Clay vein and its implication for uranium exploration activity in the northern part of the Alligator Rivers Uranium Field, northern Australia

    International Nuclear Information System (INIS)

    Sasao, Eiji

    2003-01-01

    Clay veins have been found by uranium exploration drilling around the Black Rock uranium prospect in the northern part of the alligator Rivers Uranium Field (ARUF), northern Australia. The mineralogical and chemical features are described to clarify relations with uranium mineralization, because it is not accompanied by uranium mineralization. X-ray diffraction and chemical analysis for major elements indicate that the clay vein consists mainly of chlorite (clinochlore to ferroan clinochlore) and lesser mica clay mineral (t-1M dominant). The clay vein is compared with the clay alteration zone around the uranium deposits in ARUF in terms of mode of occurrence, mineral and chemical compositions. Mineral composition of the clay vein is only in accordance with that of the inner alteration halo of the clay alteration zone. It is, however, different from mineral composition of the outer alteration halo in terms of lack of Fe chlorite in the clay vein. Chemical composition of the clay vein is similar to that of the clay alteration zone, except for lack in the vein of high iron content which is observed in some samples of the alteration zone. As a whole, the feature of the clay vein corresponds to the inner alteration zone around the uranium deposit in ARUF. The mode of occurrence of the clay vein is very different from that of the clay alteration zone. Mode of occurrence, and mineral and chemical compositions of the clay vein resemble a chlorite vein in the Lower to Middle Proterozoic sandstone above the Jabiluka deposit, one of major uranium deposit in the ARUF. Because of the similarity between the clay and the chlorite veins, the clay vein is regarded as marginal facies of an alteration zone. The fluid that formed the clay vein is estimated to have been oxidized, because of the existence of hematite and ubiquitous Mg chlorite. This nature is in accordance with the mineralizing fluid that formed the inner alteration zone in the Nabarlek deposit. In conclusion, the vein

  17. Spatial and temporal variability in estuary habitat use by American alligators

    Science.gov (United States)

    Fujisaki, Ikuko; Hart, Kristen M.; Cherkiss, Michael S.; Mazzotti, Frank J.; Beauchamp, Jeffrey S.; Jeffery, Brian M.; Brandt, Laura A.

    2016-01-01

    Estuarine habitat occupied by Alligator mississippiensis, a primarily freshwater species, is spatially and temporally heterogeneous largely due to a salinity gradient that fluctuates. Using long-term night light survey data, we examined seasonal patterns in alligators’ habitat use by size classes in midstream and downstream estuary zones of Shark River, Everglades National Park, in southern Florida. We observed predominantly large-sized alligators (total length ≥ 1.75 m); observations of alligators in the small size classes (0.5 m ≤ total length freshwater wetlands. Our results indicated high adaptability of alligators to the fluctuating habitat conditions. Use of estuaries by alligators is likely driven in part by physiology and possibly by reproductive cycle, and our results supported their opportunistic use of estuary habitat and ontogenetic niche shifts.

  18. OOGENESIS AND OVARIAN HISTOLOGY OF THE AMERICAN ALLIGATOR ALLIGATOR MISSISSIPPIENSIS

    Science.gov (United States)

    Although folliculogenesis and oogenesis have been observed in numerous reptiles, these phenomena have not been described in detail in a crocodilian. Oogenesis and histological features of the adult ovary of Alligator mississippiensis are described. Using a complex process, the ov...

  19. EFFECT OF ALLIGATOR PEPPER (ZINGIBERACEAE ...

    African Journals Online (AJOL)

    Daniel Owu

    proven fertility from a pilot study were randomly paired in fifteen cages in a well ventillated room. After three days of ... Key words : Effect, Alligator pepper, Herbal remedy, Nutrition, Pregnancy. Introduction ... ad libitum. Experimental drug.

  20. Uranium mining and indigenous social impact issues - Kakadu Region, Australia

    International Nuclear Information System (INIS)

    Wellings, P.

    2002-01-01

    This paper reports on indigenous social impact issues in the Kakadu/Alligators Rivers region of Australia. It briefly outlines the social history of the region, reflects on local, national and international attention being given to the impact of regional development on local indigenous (bininj) people, notes how social impact issues are being addressed and suggests some lessons learnt. (author)

  1. 27 CFR 9.47 - Hudson River Region.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Hudson River Region. 9.47... Hudson River Region. (a) Name. The name of the viticultural area described in this section is “Hudson River Region.” (b) Approved maps. The approved maps for determining the boundaries of Hudson River...

  2. Molecular and functional characterization of BAFF from the Yangtze alligator (Alligator sinensis, Alligatoridae).

    Science.gov (United States)

    Zhang, Jia-Xin; Song, Ren; Sang, Ming; Sun, Si-Qing; Ma, Lei; Zhang, Jie; Zhang, Shuang-Quan

    2015-10-01

    B-cell activating factor (BAFF) from the TNF family is critical for B-cell survival and maturation. In this study, we identified a Yangtze alligator (Alligator sinensis, Alligatoridae) BAFF cDNA, designated as asBAFF, using reverse transcription polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE). The open reading frame of this cDNA encodes a 287-amino acid protein containing a predicted transmembrane domain and a furin protease cleavage site, similar to mammalian and avian BAFF. The amino acid identity between biologically soluble asBAFF (assBAFF) and csBAFF, hsBAFF, and msBAFF is 94, 76, and 71%, respectively. Real-time quantitative PCR analysis showed that the asBAFF gene is strongly expressed in the spleen. Since BAFF is always expressed as inclusion bodies in bacteria, it is difficult to purify. To enhance the soluble expression of assBAFF in Escherichia coli, we fused the extracellular region of the asBAFF gene to a small ubiquitin-related modifier gene (SUMO). Purified assBAFF was able to promote the survival of splenic lymphocytes and co-stimulate the proliferation of mouse B cells with anti-mouse IgM. These findings suggest that asBAFF plays an important role in the survival and proliferation of Yangtze alligator B cells, and because it is evolutionarily highly conserved, functional cross-reactivity exists between mammalian and Yangtze alligator BAFF. Copyright © 2015 Elsevier GmbH. All rights reserved.

  3. Scale-Dependent Habitat Selection and Size-Based Dominance in Adult Male American Alligators.

    Directory of Open Access Journals (Sweden)

    Bradley A Strickland

    Full Text Available Habitat selection is an active behavioral process that may vary across spatial and temporal scales. Animals choose an area of primary utilization (i.e., home range then make decisions focused on resource needs within patches. Dominance may affect the spatial distribution of conspecifics and concomitant habitat selection. Size-dependent social dominance hierarchies have been documented in captive alligators, but evidence is lacking from wild populations. We studied habitat selection for adult male American alligators (Alligator mississippiensis; n = 17 on the Pearl River in central Mississippi, USA, to test whether habitat selection was scale-dependent and individual resource selectivity was a function of conspecific body size. We used K-select analysis to quantify selection at the home range scale and patches within the home range to determine selection congruency and important habitat variables. In addition, we used linear models to determine if body size was related to selection patterns and strengths. Our results indicated habitat selection of adult male alligators was a scale-dependent process. Alligators demonstrated greater overall selection for habitat variables at the patch level and less at the home range level, suggesting resources may not be limited when selecting a home range for animals in our study area. Further, diurnal habitat selection patterns may depend on thermoregulatory needs. There was no relationship between resource selection or home range size and body size, suggesting size-dependent dominance hierarchies may not have influenced alligator resource selection or space use in our sample. Though apparent habitat suitability and low alligator density did not manifest in an observed dominance hierarchy, we hypothesize that a change in either could increase intraspecific interactions, facilitating a dominance hierarchy. Due to the broad and diverse ecological roles of alligators, understanding the factors that influence their

  4. Scale-dependent habitat selection and size-based dominance in adult male American alligators

    Science.gov (United States)

    Strickland, Bradley A.; Vilella, Francisco; Belant, Jerrold L.

    2016-01-01

    Habitat selection is an active behavioral process that may vary across spatial and temporal scales. Animals choose an area of primary utilization (i.e., home range) then make decisions focused on resource needs within patches. Dominance may affect the spatial distribution of conspecifics and concomitant habitat selection. Size-dependent social dominance hierarchies have been documented in captive alligators, but evidence is lacking from wild populations. We studied habitat selection for adult male American alligators (Alligator mississippiensis; n = 17) on the Pearl River in central Mississippi, USA, to test whether habitat selection was scale-dependent and individual resource selectivity was a function of conspecific body size. We used K-select analysis to quantify selection at the home range scale and patches within the home range to determine selection congruency and important habitat variables. In addition, we used linear models to determine if body size was related to selection patterns and strengths. Our results indicated habitat selection of adult male alligators was a scale-dependent process. Alligators demonstrated greater overall selection for habitat variables at the patch level and less at the home range level, suggesting resources may not be limited when selecting a home range for animals in our study area. Further, diurnal habitat selection patterns may depend on thermoregulatory needs. There was no relationship between resource selection or home range size and body size, suggesting size-dependent dominance hierarchies may not have influenced alligator resource selection or space use in our sample. Though apparent habitat suitability and low alligator density did not manifest in an observed dominance hierarchy, we hypothesize that a change in either could increase intraspecific interactions, facilitating a dominance hierarchy. Due to the broad and diverse ecological roles of alligators, understanding the factors that influence their social dominance

  5. Estimating trends in alligator populations from nightlight survey data

    Science.gov (United States)

    Fujisaki, Ikuko; Mazzotti, Frank J.; Dorazio, Robert M.; Rice, Kenneth G.; Cherkiss, Michael; Jeffery, Brian

    2011-01-01

    Nightlight surveys are commonly used to evaluate status and trends of crocodilian populations, but imperfect detection caused by survey- and location-specific factors makes it difficult to draw population inferences accurately from uncorrected data. We used a two-stage hierarchical model comprising population abundance and detection probability to examine recent abundance trends of American alligators (Alligator mississippiensis) in subareas of Everglades wetlands in Florida using nightlight survey data. During 2001–2008, there were declining trends in abundance of small and/or medium sized animals in a majority of subareas, whereas abundance of large sized animals had either demonstrated an increased or unclear trend. For small and large sized class animals, estimated detection probability declined as water depth increased. Detection probability of small animals was much lower than for larger size classes. The declining trend of smaller alligators may reflect a natural population response to the fluctuating environment of Everglades wetlands under modified hydrology. It may have negative implications for the future of alligator populations in this region, particularly if habitat conditions do not favor recruitment of offspring in the near term. Our study provides a foundation to improve inferences made from nightlight surveys of other crocodilian populations.

  6. Bioprospecting the American alligator (Alligator mississippiensis host defense peptidome.

    Directory of Open Access Journals (Sweden)

    Barney M Bishop

    Full Text Available Cationic antimicrobial peptides and their therapeutic potential have garnered growing interest because of the proliferation of bacterial resistance. However, the discovery of new antimicrobial peptides from animals has proven challenging due to the limitations associated with conventional biochemical purification and difficulties in predicting active peptides from genomic sequences, if known. As an example, no antimicrobial peptides have been identified from the American alligator, Alligator mississippiensis, although their serum is antimicrobial. We have developed a novel approach for the discovery of new antimicrobial peptides from these animals, one that capitalizes on their fundamental and conserved physico-chemical properties. This sample-agnostic process employs custom-made functionalized hydrogel microparticles to harvest cationic peptides from biological samples, followed by de novo sequencing of captured peptides, eliminating the need to isolate individual peptides. After evaluation of the peptide sequences using a combination of rational and web-based bioinformatic analyses, forty-five potential antimicrobial peptides were identified, and eight of these peptides were selected to be chemically synthesized and evaluated. The successful identification of multiple novel peptides, exhibiting antibacterial properties, from Alligator mississippiensis plasma demonstrates the potential of this innovative discovery process in identifying potential new host defense peptides.

  7. Analogue studies in the alligator rivers region. In-situ measurement of uranium series nuclides with SHRIMP

    Energy Technology Data Exchange (ETDEWEB)

    Nagano, Tetsushi; Yanase, Nobuyuki; Ohnuki, Toshihiko [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Sato, Tsutomu; Isobe, Hiroshi; Williams, I.S.; Zaw, M.; Payne, T.E.; Airey, P.L.

    1999-03-01

    The SHRIMP analyses have been conducted for rock samples from the Koongarra secondary ore deposit to obtain activity ratios of {sup 234}U/{sup 238}U and isotopic ratios of {sup 207}Pb/{sup 206}Pb and {sup 204}Pb/{sup 206}Pb. Target minerals for the analyses were iron minerals and kaolinite, which are the main weathering products in this area. The activity ratios of {sup 234}U/{sup 238}U were obtained based on counts at masses of uranium metal. The {sup 234}U/{sup 238}U activity ratios based on counts of uranium oxides were not appropriate, because count rates of {sup 234}U{sup 16}O were interfered by those of {sup 238}U{sup 12}C molecule. The activity ratios of {sup 234}U/{sup 238}U were approximately unity for crystalline iron nodules. This fact suggested that the mean residence time of uranium within the iron nodules was at least 1 million years. On the other hand, slightly higher values than unity were obtained for kaolinite. Lead isotopes were investigated and a positive relationship was recognized between {sup 207}Pb/{sup 206}Pb and {sup 204}Pb/{sup 206}Pb isotope ratios. (author)

  8. Urban rivers as hotspots of regional nitrogen pollution

    International Nuclear Information System (INIS)

    Zhang, Xiaohong; Wu, Yiyun; Gu, Baojing

    2015-01-01

    Excess nitrogen inputs to terrestrial ecosystems via human activities have deteriorated water qualities on regional scales. Urban areas as settlements of over half global population, however, were usually not considered in the analysis of regional water pollution. Here, we used a 72-month monitoring data of water qualities in Hangzhou, China to test the role of urban rives in regional nitrogen pollution and how they response to the changes of human activities. Concentrations of ammonium nitrogen in urban rivers were 3–5 times higher than that in regional rivers. Urban rivers have become pools of reactive nitrogen and hotspots of regional pollution. Moreover, this river pollution is not being measured by current surface water monitoring networks that are designed to measure broader regional patterns, resulting in an underestimation of regional pollution. This is crucial to urban environment not only in China, but also in other countries, where urban rivers are seriously polluted. - Highlights: • Nitrogen concentrations in urban rivers are much higher than that in regional rivers. • Domestic wastewater is the main source of urban river pollution in Hangzhou. • Pollutant collecting and water diversion can sharply reduce the urban river pollution. - Urban river pollution is not being measured by the current monitoring networks that are designed to measure regional patterns causing an underestimation

  9. Alligator Rivers Analogue project. Geochemical Data Bases

    International Nuclear Information System (INIS)

    Bennett, D.G.; Read, D.

    1992-01-01

    The Koongarra uranium deposit in the Northern Territory of Australia is being studied to evaluate the processes involved in the geochemical alteration of the ore body and the formation of the uranium dispersion fan. A broad range of research is being undertaken into the geochemistry and hydrology of the site with the aim of understanding the transport of radionuclides through the system. During the project a range of geochemical and hydrogeochemical models have been developed to account for measured data from the site and with which to predict site evolution. The majority of these models are based on the premise of thermodynamic chemical equilibrium and employ fundamental thermodynamic data to characterise the chemistry of the system. From the differences which exist between the thermodynamic data bases (Appendices I and II) it is possible to gain a view of the level of uncertainty associated with thermodynamic data in each set of calculations. This report gives a brief introduction to the geochemical processes underlying the models, and details the equations used to quantify the more common of these processes (e.g. aqueous speciation and mineral solubility). A description is given of the computer codes (EQ3/6, PHREEQE, MINTEQ) most commonly used during the project for geochemical modelling. Their key features are highlighted and comparisons made. It is concluded that the degree of uncertainty in geochemical modelling studies arising as a result of using one code rather than another is relatively insignificant when compared to that related to differences in the underlying data bases. 73 refs., 3 figs

  10. Philosophy of river problems: local to regional, static to mobile

    International Nuclear Information System (INIS)

    Jansky, L.

    1997-01-01

    According to the statistics, thirteen of the twenty-five major river basins in Europe are basins of transboundary rivers. The Danube river basin is largest transboundary river basin in Europe. Almost in each case the local and regional problems arise, like division of fishing rights (or rights on river beds), right to claim tolls on navigation, how to adjust boundaries if the channel moves, or rights to claim duty on crossing the river, or to build bridges, weirs, etc. All the above problems on a larger scale include also rights of non-contiguous lands (i.e. not fronting on the river) to use the river for navigation, for passage of migrating fish, to exploit river (e.g. bed sediments) without damage by one country or society to another below. Similarly, pollution and large-scale removal of water, are problems on regional or national levels. Disputes usually arise from the above, more or less exacerbated by their superimposition or other non-river problems, e.g. religion, politics, historical issues, recent aggression, relative prosperity, expanding economy vs. contrasting economy. May be cause or consequence of many of these. And somewhere here is likely the case of Gabcikovo on Danube between Slovakia and Hungary, as well. (author)

  11. Glacial Fluctuation in the Source Region of the Yangtze River

    International Nuclear Information System (INIS)

    Shengyi, Gao; Qingsong, Fan; Xi, Cao; Li, Ma

    2014-01-01

    Glaciers in the source region of the Yangtze River are not only water resources but also important energy and environmental resources. Glacial fluctuation is an important component of the study of changes in the natural environment, including climate change. We investigated the glaciers in the source region of the Yangtze River, and analyzed the fluctuations using multi-temporal remote sensing data. The trend in glacial fluctuation and the factors that influence it were determined. The results have implications for water resource management and environmental conservation in the Yangtze River region

  12. Colonial Education and Women of the Cross River Region of ...

    African Journals Online (AJOL)

    As a result, there is a gap to be filled in this respect, in the historiography of the Cross River region. This is the concern of this paper. The paper reveals that the women of present-day Cross River State contributed to the educational development of their communities in cash and kind. Even of greater importance is that a few ...

  13. Regional Cooperation Efforts in the Mekong River Basin: Mitigating river-related security threats and promoting regional development

    Directory of Open Access Journals (Sweden)

    Susanne Schmeier

    2009-01-01

    Full Text Available The development of international rivers is often perceived as leading to conflicts or even water wars. However, as the development of the Mekong River shows, cooperation has not only prevailed in the last decades, but River Basin Organizations (RBOs, established to mitigate river-related conflicts and/or develop the river basin, have also contributed to the emergence of more general cooperation structures, mainly by creating spill-over effects in other issue-areas, bringing cooperation to policy fields beyond the river itself. This article assesses the contribution of the Mekong River Commission (MRC and the Greater Mekong Sub-Region (GMS to the sustainable development of the Mekong Region as well as to the promotion of regional cooperation in mainland South-East Asia in general. --- Die Entwicklung grenzüberschreitender Flüsse wird oft mit Konflikten oder gar Kriegen um Wasser assoziiert. Wie jedoch die Entwicklung im Mekong-Becken zeigt, waren die vergangenen Jahrzehnte nicht nur von Kooperation gezeichnet, sondern Flussbeckenorganisationen konnten außerdem dazu beitragen, weitreichendere Kooperationsstrukturen zu entwickeln, die sich auf andere Politikfelder ausdehnen. Dieser Artikel beschäftigt sich mit dem Beitrag der Mekong River Commission (MRC und der Greater Mekong Sub-Region (GMS zur nachhaltigen Entwicklung in der Mekong Region sowie zur Förderung allgemeiner regionaler Kooperation im Festländischen Südostasien.

  14. Age- and gender-related accumulation of perfluoroalkyl substances in captive Chinese alligators (Alligator sinensis)

    International Nuclear Information System (INIS)

    Wang, Jianshe; Zhang, Yating; Zhang, Fang; Yeung, Leo W.Y.; Taniyasu, Sachi; Yamazaki, Eriko; Wang, Renping; Lam, Paul K.S.; Yamashita, Nobuyoshi; Dai, Jiayin

    2013-01-01

    Fourteen perfluoroalkyl substances (PFASs) were measured in serum of the highly endangered captive Chinese alligators, whole body homogenates of six kinds of fish (alligator prey species), and pond water (alligator habitat) in the Anhui Research Center for Chinese Alligator Reproduction. Six PFASs, including PFOS and five perfluorinated carboxylates, were detected in all alligator samples. The most dominant PFAS was PFUnDA, with a mean value of 31.4 ng/mL. Significant positive correlations were observed among the six PFASs, suggesting that they shared similar sources of contamination. Significantly higher PFOS and PFUnDA levels were observed in males, but the other four PFCAs did not differ between genders. An age related PFAS bioaccumulation analysis showed a significant negative correlation of the concentrations for five PFCAs to age, which means that higher concentrations were found in younger animals. Bioaccumulation factors (BAF) in fish for PFASs ranged from 21 to 28,000, with lower BAF for PFOA than that for longer carbon chain PFCAs, including PFUnDA, PFDA, and PFNA. Highlights: •The most dominant PFAS was PFUnDA, followed by PFOS and PFDA in all alligator samples. •Significantly higher PFOS and PFUnDA levels were observed in males. •The concentrations of the five PFCAs showed significant negative correlation to age. -- Age- and gender-related accumulation of perfluoroalkyl substances in captive Chinese alligators

  15. An indoor air quality study of an alligator (Alligator mississippiensis) holding facility.

    Science.gov (United States)

    Wilson, S C; Holder, H W; Martin, J M; Brasel, T L; Andriychuk, L A; Wu, C; Straus, D C; Aguilar, R

    2006-06-01

    An environmental microbiologic investigation was conducted in an alligator (Alligator mississippiensis) holding facility in a zoo in the southeastern U.S. The facility had housed five alligators between March 1999 and February 2005. In the exhibit, one alligator died and all experienced poor health. It was hypothesized that environmental microbial contamination was associated with these issues. Samples were collected for fungal identification and quantification, microcystin analysis, and airborne mycotoxins. Analyses of air and water were conducted and an examination of the heating, ventilation, and air-conditioning system (HVAC) for design, maintenance, and operating issues was made. Two control sites, a facility for false gharials (Tomistoma schlegelii) and an off-site alligator breeding facility, were also tested. Morbidity and mortality records were examined for all sites. Results showed that, compared to the control sites, the test alligator facility and its HVAC system were extensively contaminated with a range of fungi. Nearly all sampled surfaces featured fungal growth. There were also significantly higher counts of Penicillium/Aspergillus-like and Chrysosporium-like spores in the air (P conditioned and mold-contaminated air being introduced to the facility. Morbidity records revealed solitary pulmonary disorders over time in three alligators, with one dying as a result. The other two alligators suffered from general malaise and a range of nonspecific symptoms. The control facilities had no morbidity or mortality issues. In conclusion, although no causal links could be demonstrated because of the nature of the morbidity data, environmental mold contamination appeared to be associated with the history of morbidity and mortality in the alligator exhibit.

  16. Bank storage buffers rivers from saline regional groundwater: an example from the Avon River Australia

    Science.gov (United States)

    Gilfedder, Benjamin; Hofmann, Harald; Cartwrighta, Ian

    2014-05-01

    Groundwater-surface water interactions are often conceptually and numerically modeled as a two component system: a groundwater system connected to a stream, river or lake. However, transient storage zones such as hyporheic exchange, bank storage, parafluvial flow and flood plain storage complicate the two component model by delaying the release of flood water from the catchment. Bank storage occurs when high river levels associated with flood water reverses the hydraulic gradient between surface water and groundwater. River water flows into the riparian zone, where it is stored until the flood water recede. The water held in the banks then drains back into the river over time scales ranging from days to months as the hydraulic gradient returns to pre-flood levels. If the frequency and amplitude of flood events is high enough, water held in bank storage can potentially perpetually remain between the regional groundwater system and the river. In this work we focus on the role of bank storage in buffering river salinity levels against saline regional groundwater on lowland sections of the Avon River, Victoria, Australia. We hypothesize that the frequency and magnitude of floods will strongly influence the salinity of the stream water as banks fill and drain. A bore transect (5 bores) was installed perpendicular to the river and were instrumented with head and electrical conductivity loggers measuring for two years. We also installed a continuous 222Rn system in one bore. This data was augmented with long-term monthly EC from the river. During high rainfall events very fresh flood waters from the headwaters infiltrated into the gravel river banks leading to a dilution in EC and 222Rn in the bores. Following the events the fresh water drained back into the river as head gradients reversed. However the bank water salinities remained ~10x lower than regional groundwater levels during most of the time series, and only slightly above river water. During 2012 SE Australia

  17. Estimating spawning times of Alligator Gar (Atractosteus spatula) in Lake Texoma, Oklahoma

    Science.gov (United States)

    Snow, Richard A.; Long, James M.

    2015-01-01

    In 2013, juvenile Alligator Gar were sampled in the reservoir-river interface of the Red River arm of Lake Texoma. The Red River, which flows 860 km along Oklahoma’s border with Texas, is the primary in-flow source of Lake Texoma, and is impounded by Denison Dam. Minifyke nets were deployed using an adaptive random cluster sampling design, which has been used to effectively sample rare species. Lapilli otoliths (one of the three pair of ear stones found within the inner ear of fish) were removed from juvenile Alligator Gar collected in July of 2013. Daily ages were estimated by counting the number of rings present, and spawn dates were back-calculated from date of capture and subtracting 8 days (3 days from spawn to hatch and 5 days from hatch to swimup when the first ring forms). Alligator Gar daily age estimation ranged from 50 to 63 days old since swim-up. Spawn dates corresponded to rising pool elevations of Lake Texoma and water pulses of tributaries.

  18. MORPHOLOGICAL VARIATION IN HATCHLING AMERICAN ALLIGATORS (ALLIGATOR MISSISSIPPIENSIS) FROM THREE FLORIDA LAKES

    Science.gov (United States)

    Morphological variation of 508 hatchling alligators from three lakes in north central Florida (Lakes Woodruff, Apopka, and Orange) was analyzed using multivariate statistics. Morphological variation was found among clutches as well as among lakes. Principal components analysis wa...

  19. Urinary Phthalate Metabolites in American Alligators (Alligator mississippiensis) from Selected Florida Wetlands.

    Science.gov (United States)

    Brock, John W; Bell, Jane Margaret; Guillette, Louis J

    2016-07-01

    Phthalates have been shown to cause endocrine disruption in laboratory animals and are associated with altered development of the reproductive system in humans. Further, human have significant exposure to phthalates. However, little is known concerning the exposure of wildlife to phthalates. We report urinary phthalate metabolite concentrations from fifty juvenile alligators from three Florida lakes and a site in the Everglades. Urinary phthalate monoester concentrations varied widely among alligators from the different sites but also among alligators from the same site. Mono-2-ethylhexy phthalate and monobutyl phthalate were found in most samples of alligator urine with maximums of 35,700 ng/mL and 193 ng/mL, respectively. Monobenzyl phthalate was found in 5 alligators with a maximum of 66.7 ng/mL. Other monoesters were found in only one or two alligator urine samples. The wide variation within and among sites, in addition to the high levels of mEHP, mBP and mBzP, is consistent with exposure arising from the intermittent spraying of herbicide formulations to control invasive aquatic plants in Florida freshwater sites. Phthalate diesters are used as adjuvants in many of these formulations.

  20. Surveys of tidal river systems in the northern territory of Australia and their crocodile populations

    Energy Technology Data Exchange (ETDEWEB)

    Vorlicek, G.C.; Messel, H.; Green, W.J.

    1986-01-01

    This book provides an update on the population dynamics of Crocodylus porous in the tidal waterways of Van Diemen Gulf and the Southern Gulf of Carpentaria, Australia, during 1984 and 1985. Contents: Prologue; Dedication; Introduction; Status of Crocodylus porous. July 1984, in the tidal waterways of the Alligator Region and in the Adelaide River System of Northern Australia: recovery underway; Resurvey of Crocodylus porous populations in the tidal waterways of the southern Gulf of Carpentaria, September - October 1985; Local knowledge - Northern Australia style.

  1. Hydrology and morphology of two river mouth regions (temperate Vistula Delta and subtropical Red River Delta

    Directory of Open Access Journals (Sweden)

    Zbigniew Pruszak

    2005-09-01

    Full Text Available The paper presents a comparative analysis of two different river mouths from two different geographical zones (subtropical and temperate climatic regions. One is the multi-branch and multi-spit mouth of the Red River on the Gulf of Tonkin (Vietnam, the other is the smaller delta of the river Vistula on a bay of the Baltic Sea (Poland. The analysis focuses on the similarities and differences in the hydrodynamics between these estuaries and the adjacent coastal zones, the features of sediment transport, and the long-term morphodynamics of the river outlets. Salinity and water level are also discussed, the latter also in the context of the anticipated global effect of accelerated sea level rise. The analysis shows that the climatic and environmental conditions associated with geographical zones give rise to fundamental differences in the generation and dynamic evolution of the river mouths.

  2. Effect of alligator pepper (Zingiberaceae Aframomum melegueta ...

    African Journals Online (AJOL)

    Fifteen male rats and fifteen female rats of proven fertility from a pilot study were randomly paired in fifteen cages in a well ventillated room. After three days of mating, the males were withdrawn from ... risk to women in their first trimester of pregnancy. Key words : Effect, Alligator pepper, Herbal remedy, Nutrition, Pregnancy ...

  3. METALS AND METALLOIDS IN TISSUES OF AMERICAN ALLIGATORS IN THREE FLORIDA LAKES

    Science.gov (United States)

    Concentrations of metals and selenium were examined in tissues of American alligators (Alligator mississippiensis) from three lakes in central Florida, in one of which alligators have exhibited reproductive or developmental defects. Our overall objective was to determine whether ...

  4. Levels of mercury in alligators (Alligator mississippiensis) collected along a transect through the Florida Everglades

    Science.gov (United States)

    Rumbold, D.G.; Fink, L.E.; Laine, K.A.; Niemczyk, S.L.; Chandrasekhar, T.; Wankel, Scott D.; Kendall, C.

    2002-01-01

    As part of a multi-agency study of alligator health, 28 American alligators (Alligator mississippiensis) were captured along a transect through the Florida Everglades in 1999. Liver and tail muscle tissues were sampled and analyzed on a wet weight basis for total mercury (THg) using cold-vapor atomic absorption spectrophotometry. All tissues had detectable concentrations of THg that ranged from 0.6 to 17 mg/kg in liver and from 0.1 to 1.8 mg/kg in tail muscle. THg was more concentrated in liver tissue than tail muscle, but levels were highly correlated between tissues. THg concentrations in tissue differed significantly among locations, with animals from Everglades National Park (ENP) having mean concentrations of THg in liver (10.4 mg/kg) and tail muscle (1.2 mg/kg) that were two-fold higher than basin-wide averages (4.9 and 0.64 mg/kg, respectively). The reasons for higher contamination of ENP alligators were unclear and could not be explained by differences in sex, length, weight or animal age. While ??15N values were positively correlated with THg concentrations in tail muscle, spatial patterns in isotopic composition did not explain the elevated THg levels in ENP alligators. Therefore, it appears that ENP alligators were more highly exposed to mercury in their environment than individuals in other areas. Comparisons to a previous survey by Yanochko et al. [Arch Environ Contam Toxicol 32 (1997) 323] suggest that mercury levels have declined in some Everglades alligators since 1994. ?? 2002 Elsevier Science B.V. All rights reserved.

  5. Blood and Plasma Biochemistry Reference Intervals for Wild Juvenile American Alligators ( Alligator mississippiensis ).

    Science.gov (United States)

    Hamilton, Matthew T; Kupar, Caitlin A; Kelley, Meghan D; Finger, John W; Tuberville, Tracey D

    2016-07-01

    : American alligators ( Alligator mississippiensis ) are one of the most studied crocodilian species in the world, yet blood and plasma biochemistry information is limited for juvenile alligators in their northern range, where individuals may be exposed to extreme abiotic and biotic stressors. We collected blood samples over a 2-yr period from 37 juvenile alligators in May, June, and July to establish reference intervals for 22 blood and plasma analytes. We observed no effect of either sex or blood collection time on any analyte investigated. However, our results indicate a significant correlation between a calculated body condition index and aspartate aminotransferase and creatine kinase. Glucose, total protein, and potassium varied significantly between sampling sessions. In addition, glucose and potassium were highly correlated between the two point-of-care devices used, although they were significantly lower with the i-STAT 1 CG8+ cartridge than with the Vetscan VS2 Avian/Reptile Rotor. The reference intervals presented herein should provide baseline data for evaluating wild juvenile alligators in the northern portion of their range.

  6. Biological activity of alligator, avian, and mammalian insulin in juvenile alligators: plasma glucose and amino acids.

    Science.gov (United States)

    Lance, V A; Elsey, R M; Coulson, R A

    1993-02-01

    The biological activity of alligator, turkey, and bovine insulin on plasma glucose and plasma amino acids was tested in fasted juvenile alligators. Preliminary experiments showed that the stress associated with taking the initial blood sample resulted in a hyperglycemic response lasting more than 24 hr. Despite repeated bleedings no additional hyperglycemic events occurred, and blood glucose declined slowly over the next 7 days. Under these conditions the smallest dose of insulin eliciting a hypoglycemic response was 40 micrograms/kg body wt. A dose of 400 micrograms/kg body wt of either alligator or bovine insulin caused a pronounced hypoglycemia by 12 hr postinjection. Maximum decline in plasma glucose occurred at 24 to 36 hr with a slow return to control levels by 120 hr. There were no significant differences in the hypoglycemic responses to any of the three insulins tested. The decline in plasma amino acids was much more rapid than the decline in plasma glucose in response to insulin. Even at the 40 micrograms/kg body wt dose a significant difference from saline-injected control was seen at 2 hr postinjection. Maximum decline in plasma amino acids occurred at 8 to 12 hr with a return to baseline by 36 hr. These results show that the relatively conservative changes in the sequence of alligator insulin (three amino acid substitutions in the B-chain compared with that of chicken) have little effect on biological activity and that alligator insulin receptors do not appear to discriminate among the three insulins.

  7. Radioecological monitoring of transboundary rivers of the Central Asian Region

    International Nuclear Information System (INIS)

    Yuldashev, B.S.; Salikhbaev, U.S.; Kist, A.A.; Radyuk, D.S.; Vdovina, E.D.; Zhuk, L.I.

    2005-01-01

    Results of radioecological investigation of Central Asian rivers are presented. Investigation was done as part of the Navruz Project, a cooperative, transboundary river monitoring project involving rivers and institutions in Kazakhstan, Kyrgyzstan, Tajikistan, and Uzbekistan, and facilitated by Sandia National Laboratories in the United States. The study of waterborne radionuclides and metals concentrations in Central Asia is of particular interest because of the history of nuclear materials mining, fabrication, transport, and storage there, when it was part of the Soviet Union. This development left a legacy of radionuclides and metals contamination in some Central Asian regions, which poses a clear health hazard to populations who rely heavily upon surface water for agricultural irrigation and direct domestic consumption. (author)

  8. Regional economic impacts of Grand Canyon river runners.

    Science.gov (United States)

    Hjerpe, Evan E; Kim, Yeon-Su

    2007-10-01

    Economic impact analysis (EIA) of outdoor recreation can provide critical social information concerning the utilization of natural resources. Outdoor recreation and other non-consumptive uses of resources are viewed as environmentally friendly alternatives to extractive-type industries. While outdoor recreation can be an appropriate use of resources, it generates both beneficial and adverse socioeconomic impacts on rural communities. The authors used EIA to assess the regional economic impacts of rafting in Grand Canyon National Park. The Grand Canyon region of northern Arizona represents a rural US economy that is highly dependent upon tourism and recreational expenditures. The purpose of this research is twofold. The first is to ascertain the previously unknown regional economic impacts of Grand Canyon river runners. The second purpose is to examine attributes of these economic impacts in terms of regional multipliers, leakage, and types of employment created. Most of the literature on economic impacts of outdoor recreation has focused strictly on the positive economic impacts, failing to illuminate the coinciding adverse and constraining economic impacts. Examining the attributes of economic impacts can highlight deficiencies and constraints that limit the economic benefits of recreation and tourism. Regional expenditure information was obtained by surveying non-commercial boaters and commercial outfitters. The authors used IMPLAN input-output modeling to assess direct, indirect, and induced effects of Grand Canyon river runners. Multipliers were calculated for output, employment, and income. Over 22,000 people rafted on the Colorado River through Grand Canyon National Park in 2001, resulting in an estimated $21,100,000 of regional expenditures to the greater Grand Canyon economy. However, over 50% of all rafting-related expenditures were not captured by the regional economy and many of the jobs created by the rafting industry are lower-wage and seasonal. Policy

  9. In vitro drug susceptibility pattern of Mycoplasma alligatoris isolated from symptomatic American alligators (Alligator mississippiensis).

    Science.gov (United States)

    Helmick, Kelly E; Brown, Daniel R; Jacobson, Elliott R; Brown, Mary B

    2002-06-01

    A recently described mycoplasma, Mycoplasma alligatoris, was isolated from dead American alligators (Alligator mississippiensis) that had demonstrated clinical signs of lethargy, anorexia, bilateral ocular discharge, edema. paraparesis, and polyarthritis. The in vitro minimum inhibitory concentration for nine antibacterial agents was determined through serial dilution in broth and plate culture for M. alligatoris isolates. The inhibitory concentration obtained for doxycycline, enrofloxacin, sarafloxacin, oxytetracycline, tilmicosin, and tylosin (< 1 microg/ml) was lower than that of clindamycin (1-8 microg/ml), chloramphenicol (8-16 microg/ml), and erythromycin (32-138 microg/ml).

  10. Effect of aqueous extract of alligator pepper ( Aframomum malegueta )

    African Journals Online (AJOL)

    ... concentration 7days post intervention; and a significant decrease in Cl− concentration 14 days post-intervention. Our findings suggest that intraperitoneally injected aqueous extract of alligator pepper induces reversible changes in serum electrolytes. Key words: Alligator pepper, Electrolytes, Homeostasis, Renal function ...

  11. Pathology, physiologic parameters, tissue contaminants, and tissue thiamine in morbid and healthy central Florida adult American alligators (Alligator mississippiensis)

    Science.gov (United States)

    Honeyfield, D.C.; Ross, J.P.; Carbonneau, D.A.; Terrell, S.P.; Woodward, A.R.; Schoeb, T.R.; Perceval, H.F.; Hinterkopf, J.P.

    2008-01-01

    An investigation of adult alligator (Alligator mississippiensis) mortalities in Lake Griffin, central Florida, was conducted from 1998-2004. Alligator mortality was highest in the months of April and May and annual death count peaked in 2000. Bacterial pathogens, heavy metals, and pesticides were not linked with the mortalities. Blood chemistry did not point to any clinical diagnosis, although differences between impaired and normal animals were noted. Captured alligators with signs of neurologic impairment displayed unresponsive and uncoordinated behavior. Three of 21 impaired Lake Griffin alligators were found to have neural lesions characteristic of thiamine deficiency in the telencephalon, particularly the dorsal ventricular ridge. In some cases, lesions were found in the thalamus, and parts of the midbrain. Liver and muscle tissue concentrations of thiamine (vitamin B"1) were lowest in impaired Lake Griffin alligators when compared to unimpaired alligators or to alligators from Lake Woodruff. The consumption of thiaminase-positive gizzard shad (Dorosoma cepedianum) is thought to have been the cause of the low tissue thiamine and resulting mortalities. ?? Wildlife Disease Association 2008.

  12. Chronic hypoxic incubation blunts a cardiovascular reflex loop in embryonic American alligator (Alligator mississippiensis).

    Science.gov (United States)

    Eme, John; Hicks, James W; Crossley, Dane A

    2011-10-01

    Hypoxia is a naturally occurring environmental challenge for embryonic non-avian reptiles, and this study is the first to investigate the impact of chronic hypoxia on a possible chemoreflex loop in a developing non-avian reptile. We measured heart rate and blood pressure in normoxic and hypoxic-incubated (10% O(2)) American alligator embryos (Alligator mississippiensis) at 70 and 90/95% of development. We hypothesized that hypoxic incubation would blunt embryonic alligators' response to a reflex loop stimulated by phenylbiguanide (PBG), a 5-HT(3) receptor agonist that stimulates vagal pulmonary C-fiber afferents. PBG injection caused a hypotensive bradycardia in 70 and 95% of development embryos (paired t tests, P alligator, with an extended length of time between each developmental stage relative to avian species, may provide an excellent model to test the cardiorespiratory effects of prolonged exposure to changes in atmospheric gases. This extended period allows for lengthy studies at each stage without the transition to a new stage, and the natural occurrence of hypoxia and hypercapnia in crocodilian nests makes this stress ecologically and evolutionarily relevant.

  13. Biophysics of directional hearing in the American alligator (Alligator mississippiensis)

    DEFF Research Database (Denmark)

    Bierman, Hilary S; Thornton, Jennifer L; Jones, Heath G

    2014-01-01

    Physiological and anatomical studies have suggested that alligators have unique adaptations for spatial hearing. Sound localization cues are primarily generated by the filtering of sound waves by the head. Different vertebrate lineages have evolved external and/or internal anatomical adaptations ...... in the extinct dinosaurs....

  14. Thermoregulatory adaptations and heat energy budget analyses of the American alligator, Alligator mississippiensis

    Energy Technology Data Exchange (ETDEWEB)

    Terpin, Kenneth M. [Univ. at Buffalo, NY (United States)

    1976-01-01

    Wild alligators were acclimated to laboratory conditions and thermocouples were surgically implanted at seven locations in the body. Animals were tested at different steady state environmental conditions in a climate space simulation chamber in order to ascertain the effect of heat transfer on body temperature. Results are reported.

  15. Fluctuating water depths affect American alligator (Alligator mississippiensis) body condition in the Everglades, Florida, USA

    Science.gov (United States)

    Brandt, Laura A.; Beauchamp, Jeffrey S.; Jeffery, Brian M.; Cherkiss, Michael S.; Mazzotti, Frank J.

    2016-01-01

    Successful restoration of wetland ecosystems requires knowledge of wetland hydrologic patterns and an understanding of how those patterns affect wetland plant and animal populations.Within the Everglades, Florida, USA restoration, an applied science strategy including conceptual ecological models linking drivers to indicators is being used to organize current scientific understanding to support restoration efforts. A key driver of the ecosystem affecting the distribution and abundance of organisms is the timing, distribution, and volume of water flows that result in water depth patterns across the landscape. American alligators (Alligator mississippiensis) are one of the ecological indicators being used to assess Everglades restoration because they are a keystone species and integrate biological impacts of hydrological operations through all life stages. Alligator body condition (the relative fatness of an animal) is one of the metrics being used and targets have been set to allow us to track progress. We examined trends in alligator body condition using Fulton’s K over a 15 year period (2000–2014) at seven different wetland areas within the Everglades ecosystem, assessed patterns and trends relative to restoration targets, and related those trends to hydrologic variables. We developed a series of 17 a priori hypotheses that we tested with an information theoretic approach to identify which hydrologic factors affect alligator body condition. Alligator body condition was highest throughout the Everglades during the early 2000s and is approximately 5–10% lower now (2014). Values have varied by year, area, and hydrology. Body condition was positively correlated with range in water depth and fall water depth. Our top model was the “Current” model and included variables that describe current year hydrology (spring depth, fall depth, hydroperiod, range, interaction of range and fall depth, interaction of range and hydroperiod). Across all models, interaction

  16. Umbilical scarring in hatchling American alligators

    Science.gov (United States)

    Wiebe, J.J.; Sepulveda, M.S.; Buckland, J.E.; Anderson, S.R.; Gross, T.S.

    2004-01-01

    Umbilical scarring is the presence of excess scar tissue deposited between abdominal dermal layers at the site of yolk sac absorption in hatchling American alligators (Alligator mississippiensis). The presence of this dermal condition plays a key evaluatory role in the overall quality and subsequent value for various commercial leather products. Despite the prevalent nature of this condition, currently the industry has no standardized protocols for its quantification. The objectives of this study were to examine the relationship between hatchling weight and age and incidence of umbilical scarring and to develop a quantifiable and reproducible technique to measure this dermal condition in hatchling American alligators. Thirty eggs from each of nine clutches were incubated in two separate incubators at different facilities and hatchling umbilical scarring was measured at 2 and 10 days of age using digital calipers. Umbilical area was calculated by multiplying umbilical length times umbilical width. There was a significant effect of both age and clutch on umbilical area (overall decline of 64%) by 10 days post-hatch. However, only five of the nine clutches utilized expressed a noticeable decline in the size of this dermal condition (range 67-74%). We had hypothesized that larger hatchlings would have larger umbilical areas and a slower rate of improvement in this condition during the first few days post-hatch. The differences in umbilical area and percent decline with age across clutches, however, were not associated with differences in initial hatchling weights. Within clutches and time periods, hatchling weight had no significant effect on the size and/or rate of decline of this condition. ?? 2004 Published by Elsevier B.V.

  17. Influence of group II metals on Radium-226 concentration ratios in the native green plum (Buchanania obovata) from the Alligator Rivers Region, Northern Territory, Australia

    International Nuclear Information System (INIS)

    Medley, Peter; Bollhöfer, Andreas

    2016-01-01

    In this study, uptake of Ra from soil, and the influence of group II metals on Ra uptake, into the stones and edible flesh of the fruit of the wild green plum, Buchanania obovata, was investigated. Selective extraction of the exchangeable fraction of the soil samples was undertaken but was not shown to more reliably predict Ra uptake than total soil Ra activity concentration. Comparison of the group II metal to Ca ratios (i.e. Sr/Ca, Ba/Ca, Ra/Ca) in the flesh with exchangeable Ca shows that Ca outcompetes group II metals for root uptake and that the uptake pathway discriminated against group II metals relative to ionic radius, with uptake of Ca > Sr > Ba >> Ra. Flesh and stone analysis showed that movement of group II metals to these components of the plant, after root uptake, was strongly related. This supports the hypothesis that Sr, Ba and Ra are being taken up as analogue elements, and follow the same uptake and translocation pathways, with Ca. Comparison with previously reported data from a native passion fruit supports the use of total soil CRs on natural, undisturbed sites. As exchangeable CRs for Ra reach a saturation value it may be possible to make more precise predictions using selective extraction techniques for contaminated or disturbed sites. - Highlights: • We studied uptake of Ra-226 from soil into Buchanania obovata. • The influence of group II metals (Sr, Ba and Ca) on Ra uptake was investigated. • The exchangeable Ra fraction of the soil was not a more reliable predictor of Ra uptake than total soil Ra. • Ca outcompetes group II metals Sr, Ba and Ra for root uptake. • Uptake discriminated against group II metals relative to ionic radius, with uptake of Ca > Sr > Ba >> Ra.

  18. Managing the Ranger uranium mine in the Alligator Rivers Region -there is much more to this business enterprise than just production

    International Nuclear Information System (INIS)

    Leggate, J.

    1984-01-01

    Environmental protection is very closely and continuously regulated at the Ranger uranium mine. Since the commencement of operations at Ranger the company has operated within these regulations and demonstrated clearly that yellowcake can be produced efficiently, economically and safely. The company also recognises that in order to ensure continuity of production, it will have to continue to operate within these strictly supervised regulations

  19. Rapid suppression of testosterone secretion after capture in male American alligators (Alligator mississippiensis).

    Science.gov (United States)

    Lance, Valentine A; Elsey, Ruth M; Butterstein, George; Trosclair, Phillip L

    2004-01-15

    All reptiles studied to date show an increase in circulating corticosterone following capture. This rise in corticosterone has also been shown in a number of instances to result in a decline in reproductive steroids within hours after capture. As a result of these observations it has been considered imperative to collect blood samples as soon as possible after capture to get reliable measures of reproductive hormones. It has been claimed, however, that there is no effect of capture stress on reproductive steroids in juvenile alligators held for 2 h following capture. As we generally reject blood samples that are not collected within 15 min of capture we decided to reinvestigate the effect of short-term capture (2 h) on corticosterone and testosterone in male alligators. Four groups of alligators, ranging in size from 74 to 212 cm total length were captured in a 2-week period in May, the time of year when testosterone levels are highest. Two groups were captured during the day (eight bled at capture and again at 2 h, eight bled at 2 h only) and two at night (10 bled at capture and again at 2 h, 10 bled at 2 h only). Testosterone and corticosterone in alligators bled immediately on capture and at 2 h were not significantly different in the AM and PM samples so the results were combined (Initial bleed: corticosterone, 0.95 +/- 0.09 ng/ml, n=18; testosterone, 6.06 +/- 2.09 ng/ml, n=18. Two-hour bleed: corticosterone 15.68 +/- 1.91, n=18; testosterone, 2.75 +/- 0.79, n=18). Both the increase in corticosterone and the decline in testosterone at 2 h were significant (palligators sampled only once at 2 h were not significantly different from the 2-h values in alligators sampled twice (corticosterone 15.04 +/- 1.29, n=18; testosterone, 1.85 +/- 0.62, n=18). These results clearly demonstrate that short-term capture stress results in a significant decline in testosterone in male alligators.

  20. Regional lead isotope study of a polluted river catchment: River Wear, Northern England, UK

    International Nuclear Information System (INIS)

    Shepherd, Thomas J.; Chenery, Simon R.N.; Pashley, Vanessa; Lord, Richard A.; Ander, Louise E.; Breward, Neil; Hobbs, Susan F.; Horstwood, Matthew; Klinck, Benjamin A.; Worrall, Fred

    2009-01-01

    High precision, lead isotope analyses of archived stream sediments from the River Wear catchment, northeast England (1986-88), provide evidence for three main sources of anthropogenic lead pollution; lead mining, industrial lead emissions and leaded petrol. In the upper catchment, pollution is totally controlled and dominated by large lead discharges from historic mining centres in the North Pennine Orefield ( 208 Pb/ 206 Pb, 207 Pb/ 206 Pb ratios range from 2.0744-2.0954 and 0.8413-0.8554 respectively). In the lower catchment, co-extensive with the Durham Coalfield and areas of high population density, pollution levels are lower and regionally more uniform. Isotope ratios are systematically higher than in the upper catchment ( 208 Pb/ 206 Pb, 207 Pb/ 206 Pb ratios range from 2.0856-2.1397 and 0.8554-0.8896 respectively) and far exceed values determined for the geogenic regional background. Here, the pollution is characterised by the atmospheric deposition of industrial lead and petrol lead. Lead derived from the combustion of coal, although present, is masked by the other two sources. Recent sediments from the main channel of the River Wear are isotopically indistinguishable from older, low order stream sediments of the North Pennine Orefield, indicating that contamination of the river by lead mining waste (up to several 1000 mg/kg Pb at some locations) continues to pose an environmental problem; a pattern that can be traced all the way to the tidal reach. Using within-catchment isotope variation and sediment lead concentrations, estimates can be made of the discharges from discrete mines or groups of mines to the overall level of lead pollution in the River Wear. As well as providing information pertinent to source apportionment and on-going catchment remediation measures, the database is a valuable resource for epidemiologists concerned with the health risks posed by environmental lead.

  1. Regional lead isotope study of a polluted river catchment: River Wear, Northern England, UK

    Energy Technology Data Exchange (ETDEWEB)

    Shepherd, Thomas J., E-mail: shepherdtj@aol.com [Department of Earth Sciences, University of Durham, Science Laboratories, Durham DH1 3LE (United Kingdom); Chenery, Simon R.N. [British Geological Survey, Nicker Hill, Keyworth, Nottingham NG12 5GG (United Kingdom); Pashley, Vanessa [NERC Isotope Geosciences Laboratory, Kingsley Dunham Centre, Keyworth, Nottingham NG12 5GG (United Kingdom); Lord, Richard A. [School of Science and Technology, University of Teesside, Middlesbrough, Tees Valley TS1 3BA (United Kingdom); Ander, Louise E.; Breward, Neil; Hobbs, Susan F. [British Geological Survey, Nicker Hill, Keyworth, Nottingham NG12 5GG (United Kingdom); Horstwood, Matthew [NERC Isotope Geosciences Laboratory, Kingsley Dunham Centre, Keyworth, Nottingham NG12 5GG (United Kingdom); Klinck, Benjamin A. [British Geological Survey, Nicker Hill, Keyworth, Nottingham NG12 5GG (United Kingdom); Worrall, Fred [Department of Earth Sciences, University of Durham, Science Laboratories, Durham DH1 3LE (United Kingdom)

    2009-08-15

    High precision, lead isotope analyses of archived stream sediments from the River Wear catchment, northeast England (1986-88), provide evidence for three main sources of anthropogenic lead pollution; lead mining, industrial lead emissions and leaded petrol. In the upper catchment, pollution is totally controlled and dominated by large lead discharges from historic mining centres in the North Pennine Orefield ({sup 208}Pb/{sup 206}Pb, {sup 207}Pb/{sup 206}Pb ratios range from 2.0744-2.0954 and 0.8413-0.8554 respectively). In the lower catchment, co-extensive with the Durham Coalfield and areas of high population density, pollution levels are lower and regionally more uniform. Isotope ratios are systematically higher than in the upper catchment ({sup 208}Pb/{sup 206}Pb, {sup 207}Pb/{sup 206}Pb ratios range from 2.0856-2.1397 and 0.8554-0.8896 respectively) and far exceed values determined for the geogenic regional background. Here, the pollution is characterised by the atmospheric deposition of industrial lead and petrol lead. Lead derived from the combustion of coal, although present, is masked by the other two sources. Recent sediments from the main channel of the River Wear are isotopically indistinguishable from older, low order stream sediments of the North Pennine Orefield, indicating that contamination of the river by lead mining waste (up to several 1000 mg/kg Pb at some locations) continues to pose an environmental problem; a pattern that can be traced all the way to the tidal reach. Using within-catchment isotope variation and sediment lead concentrations, estimates can be made of the discharges from discrete mines or groups of mines to the overall level of lead pollution in the River Wear. As well as providing information pertinent to source apportionment and on-going catchment remediation measures, the database is a valuable resource for epidemiologists concerned with the health risks posed by environmental lead.

  2. A Regional Survey of River-plume Sedimentation on the Mississippi River Delta Front

    Science.gov (United States)

    Courtois, A. J.; Bentley, S. J.; Xu, K.; Georgiou, I. Y.; Maloney, J. M.; Miner, M. D.; Chaytor, J. D.; Smith, J.

    2017-12-01

    Many studies of the Mississippi River and Delta (MRD) have shown historic declines in sediment load reaching the main river distributaries over the last few decades. Recent studies also reported that 50% of the suspended load during floods is sequestered within the delta. While the impact of declining sediment load on wetland loss is well documented, submarine sedimentary processes on the delta front during this recent period of declining sediment load are understudied. To better understand modern sediment dispersal and deposition across the Mississippi River Delta Front, 31 multicores were collected in June 2017 from locations extending offshore from Southwest Pass, South Pass, and Pass a Loutre (the main river outlets) in water depths of 25-280 m. Core locations were selected based on multibeam bathymetry and morphology collected by the USGS in May 2017; the timing of collection coincided with the end of annual peak discharge on the Mississippi River. This multi-agency survey is the first to study delta-front sedimentary processes regionally with such a wide suite of tools. Target locations for coring included the dominant depositional environments: mudflow lobes, gullies, and undisturbed prodelta. Cores were subsampled at 2 cm intervals and analyzed for Beryllium-7 activity via gamma spectrometry; in such settings, Be-7 can be used as a tracer of sediment recently delivered from fluvial origin. Results indicate a general trend of declining Be-7 activity with increasing distance from source, and in deeper water. Inshore samples near Southwest Pass show the deepest penetration depth of Be-7 into the sediment (24-26 cm), which is a preliminary indicator of rapid seasonal sedimentation. Nearshore samples from South Pass exhibited similar Be-7 penetration depths, with results near Pass a Loutre to 14-16 cm depth. Be-7 remains detectable to 2 cm in water 206 m deep, approximately 20 km from South Pass. Sediment dispersal remains impressive offshore from all three

  3. Gulf-Wide Information System, Environmental Sensitivity Index Alligator Database, Geographic NAD83, LDWF (2001) [esi_gator_LDWF_2001

    Data.gov (United States)

    Louisiana Geographic Information Center — This data set contains sensitive biological resource data for American alligator in coastal Louisiana. Vector polygons represent alligator habitats with nest density...

  4. The Demographics of Travel in the Two Rivers-Ottauquechee Region

    Science.gov (United States)

    2009-02-19

    In March of 2008, the Two Rivers-Ottauquechee Regional Commission (TRORC) contracted with TranSystems, a consulting firm based in Montpelier, to conduct a regional transportation planning study for the region. Called the Demographics of Transportatio...

  5. Hexavalent Chromium Is Cytotoxic and Genotoxic to American Alligator Cells

    OpenAIRE

    Wise, Sandra S.; Wise, Catherine; Xie, Hong; Guillette, Louis J.; Zhu, Cairong; Wise, John Pierce; Wise, John Pierce

    2015-01-01

    Metals are a common pollutant in the aquatic ecosystem. With global climate change, these levels are anticipated to rise as lower pH levels allow sediment bound metals to be released. The American alligator (Alligator mississippiensis) is an apex predator in the aquatic ecosystem and is considered a keystone species; as such it serves as a suitable monitor for localized pollution. One metal of increasing concern is hexavalent chromium (Cr(VI)). It is present in the aquatic environment and is ...

  6. Climate change impact on the river runoff: regional study for the Central Asian Region

    International Nuclear Information System (INIS)

    Agaitseva, Natalya

    2004-01-01

    increase is expected in evaporation from water surfaces of 15-20%. The most severe and climate conditions in the watershed area were predicted under the CCCM model. According to this model, if CO 2 concentration in the atmosphere is doubled, then the runoffs of the Syrdarya and Amudarya rivers are expected to be reduced by 28 and 40%, respectively. According to GFDL and GISS scenarios, presented.(Author)e experiencethe catchment area would increase by 3-4 o C and average annual precipitation volume by 10-15%. Under these scenarios, one could expect that no significant reduction in the Amudarya and Syrdarya runoff would occur. An air temperature rise of 1-2 o C will intensify the process of ice degradation. In 1957-180 glaciers in the Aral Sea river basins lost 115.5 km 3 Of ice (approximately 104 km 3 of water), which constituted almost 20 per cent of the 1957 ice reserve. By 2000 another 14 per cent of the 1957 reserve were lost. By 2020 glaciers will lose at least another 10 per cent of their initial volume. Calculations of regional climatic scenarios by the year 2030 also indicate persistence of present runoff volumes accompanied by an increase in fluctuations from year. Longer-term assessments are more pessimistic, since, along with increasing evaporation, water resource inputs (snow and glaciers in the mountains) are continuously shrinking. (Author)

  7. Stress-induced suppression of testosterone secretion in male alligators.

    Science.gov (United States)

    Lance, V A; Elsey, R M

    1986-08-01

    In order to test the effect of acute stress on gonadal hormone secretion in reptiles, six mature male alligators were captured, and a blood sample was taken within 5 min of capture. Additional blood samples were taken at timed intervals for up to 41 hr, and plasma testosterone and corticosterone were measured by radioimmunoassay. Plasma testosterone declined to 50% of the initial value by 4 hr and dropped to less than 10% of initial by 24 hr. Plasma corticosterone increased during the first 12 hr, declined at 24 hr, and rose again at 40 hr. Blood samples from male alligators collected in North and South Carolina, south Florida, and in south Louisiana in two consecutive breeding seasons were also assayed for testosterone and corticosterone. In these populations there were significant differences in mean plasma testosterone and corticosterone levels. Elevated corticosterone levels were consistently seen in alligators caught in traps and from which a blood sample was taken several hours later. Plasma testosterone, although consistently lower in trapped alligators, did not show a negative correlation with plasma corticosterone. Farm-reared alligators bled once, released, and bled again at 24 hr also showed a highly significant suppression of testosterone secretion. These results demonstrate that stress has a rapid and dramatic effect on testicular steroid secretion in both farm-reared and wild alligators.

  8. Effects of feeding on arterial blood gases in the American alligator Alligator mississippiensis.

    Science.gov (United States)

    Busk, M; Overgaard, J; Hicks, J W; Bennett, A F; Wang, T

    2000-10-01

    Reptiles habitually ingest large meals at infrequent intervals, leading to changes in acid-base status as the net secretion of acid to the stomach causes a metabolic alkalosis (the alkaline tide). In chronically cannulated and undisturbed amphibians and reptiles, the pH changes in arterial blood are, nevertheless, reduced by a concomitant respiratory acidosis (increased P(CO2) caused by a relative hypoventilation). Alligators (Alligator mississippiensis) have been reported to exhibit exceptionally large increases in plasma [HCO3(-)] following feeding, but these studies were based on blood samples obtained by cardiac puncture, so stress and disturbance may have affected the blood gas levels. Furthermore, crocodilian haemoglobin is characterised by a unique binding of HCO3(-) that act to reduce blood oxygen-affinity, and it has been proposed that this feature safeguards oxygen offloading by counteracting pH effects on blood oxygen-affinity. Therefore, to study acid-base regulation and the interaction between the alkaline tide and oxygen transport in more detail, we describe the arterial blood gas composition of chronically cannulated and undisturbed alligators before and after voluntary feeding (meal size 7.5+/-1% of body mass). Digestion was associated with an approximately fourfold increase in metabolic rate (from 0.63+/-0.04 to 2.32+/-0.24 ml O(2) min(-1)kg(-1)) and was accompanied by a small increase in the respiratory gas exchange ratio. The arterial P(O2) of fasting alligators was 60.3+/-6.8 mmHg (1 mmHg = 0.133 kPa) and reached a maximum of 81.3+/-2.7 mmHg at 96 h following feeding; there was only a small increase in lactate levels, so the increased metabolic rate seems to be entirely aerobic. Plasma [HCO3(-)] increased from 24.4+/-1.1 to 36.9+/-1.7 mmol l(-1) (at 24 h), but since arterial P(CO2) increased from 29.0+/-1.1 to 36.8+/-1.3 mmHg, arterial pH remained virtually unaffected (changing from 7.51+/-0.01 to 7.58+/-0.01 at 24 h). The changes in plasma [HCO

  9. Analysis of pumping-induced unsaturated regions beneath aperennial river

    Energy Technology Data Exchange (ETDEWEB)

    Su, G.W.; Jasperse, J.; Seymour, D.; Constantz, J.; Zhou, Q.

    2007-05-15

    The presence of an unsaturated region beneath a streambedduring groundwater pumping near streams reduces the pumping capacity whenit reaches the well screens, changes flow paths, and alters the types ofbiological transformations in the streambed sediments. Athree-dimensional, multi-phase flow model of two horizontal collectorwells along the Russian River near Forestville, California was developedto investigate the impact of varying the ratio of the aquifer tostreambed permeability on (1) the formation of an unsaturated regionbeneath the stream, (2) the pumping capacity, (3) stream-water fluxesthrough the streambed, and (4) stream-water travel times to the collectorwells. The aquifer to streambed permeability ratio at which theunsaturated region was initially observed ranged from 10 to 100. The sizeof the unsaturated region beneath the streambed increased as the aquiferto streambed permeability ratio increased. The simulations also indicatedthat for a particular aquifer permeability, decreasing the streambedpermeability by only a factor of 2-3 from the permeability wheredesaturation initially occurred resulted in reducing the pumpingcapacity. In some cases, the stream-water fluxes increased as thestreambed permeability decreased. However, the stream water residencetimes increased and the fraction of stream water that reached that thewells decreased as the streambed permeability decreased, indicating thata higher streambed flux does not necessarily correlate to greaterrecharge of stream water around the wells.

  10. Physicochemical composition of water of Sirdariya River (within of Sogd region)

    International Nuclear Information System (INIS)

    Mirsaidov, U.M.; Khakimov, N.; Murtazaev, Kh.; Sufiev, A.

    2010-01-01

    Present article is devoted to physicochemical composition of water of Sirdariya River (within of Sogd region). During 12 months the physicochemical composition of above mentioned river was studied by means of water sampling from 10 points of river. The analysis was conducted and it was defined that the main contaminants of the river are the plant facilities, the deposits of radioactive ores and agricultural grounds.

  11. Analysis of PFAAs in American alligators part 2: Potential dietary exposure of South Carolina hunters from recreationally harvested alligator meat.

    Science.gov (United States)

    Tipton, Jessica J; Guillette, Louis J; Lovelace, Susan; Parrott, Benjamin B; Rainwater, Thomas R; Reiner, Jessica L

    2017-11-01

    Exposure to perfluorinated alkyl acids (PFAAs) has been linked to many harmful health effects including reproductive disorders, developmental delays, and altered liver and kidney function. Most human exposure to environmental contaminants, including PFAAs, occurs through consumption of contaminated food or drinking water. This study uses PFAA data from meat samples collected from recreationally harvested American alligators (Alligator mississippiensis) in South Carolina to assess potential dietary exposure of hunters and their families to PFAAs. Consumption patterns were investigated using intercept surveys of 23 hunters at a wild game meat processor. An exposure scenario using the average consumption frequency, portion size, and median perfluorooctane sulfonic acid (PFOS) concentration in alligator meat from all hunt units found the daily dietary exposure to be 2.11ng/kg body weight per day for an adult human. Dietary PFOS exposure scenarios based on location of harvest suggested the highest daily exposure occurs with alligator meat from the Middle Coastal hunt unit in South Carolina. Although no samples were found to exceed the recommended threshold for no consumption of PFOS found in Minnesota state guidelines, exposure to a mixture of PFAAs found in alligator meat and site-specific exposures based on harvest location should be considered in determining an appropriate guideline for vulnerable populations potentially exposed to PFAAs through consumption of wild alligator meat. Copyright © 2017. Published by Elsevier B.V.

  12. Effects of prolonged lung inflation or deflation on pulmonary stretch receptor discharge in the alligator (Alligator mississippiensis).

    Science.gov (United States)

    Marschand, Rachel E; Wilson, Jenna L; Burleson, Mark L; Crossley, Dane A; Hedrick, Michael S

    2014-08-15

    The American alligator (Alligator mississippiensis) is a semi-aquatic diving reptile that has a periodic breathing pattern. Previous work identified pulmonary stretch receptors, that are rapidly and slowly adapting, as well as intrapulmonary chemoreceptors (IPC), sensitive to CO2, that modulate breathing patterns in alligators. The purpose of the present study was to quantify the effects of prolonged lung inflation and deflation (simulated dives) on pulmonary stretch receptors (PSR) and/or IPC discharge characteristics. The effects of airway pressure (0-20 cm H2O), hypercapnia (7% CO2), and hypoxia (5% O2) on dynamic and static responses of PSR were studied in juvenile alligators (mean mass=246 g) at 24°C. Alligators were initially anesthetized with isoflurane, cranially pithed, tracheotomized and artificially ventilated. Vagal afferent tonic and phasic activity was recorded with platinum hook electrodes. Receptor activity was a mixture of slowly adapting PSR (SAR) and rapidly adapting PSR (RAR) with varying thresholds and degrees of adaptation, without CO2 sensitivity. Receptor activity before, during and after 1 min periods of lung inflation and deflation was quantified to examine the effect of simulated breath-hold dives. Some PSR showed a change in dynamic response, exhibiting inhibition for several breaths after prolonged lung inflation. Following 1 min deflation, RAR, but not SAR, exhibited a significant potentiation of burst frequency relative to control. For SAR, the post-inflation receptor inhibition was blocked by CO2 and hypoxia; for RAR, the post-inflation inhibition was potentiated by CO2 and blocked by hypoxia. These results suggest that changes in PSR firing following prolonged inflation and deflation may promote post-dive ventilation in alligators. We hypothesize that PSR in alligators may be involved in recovery of breathing patterns and lung volume during pre- and post-diving behavior and apneic periods in diving reptiles. Copyright © 2014

  13. Hexavalent chromium is cytotoxic and genotoxic to American alligator cells.

    Science.gov (United States)

    Wise, Sandra S; Wise, Catherine; Xie, Hong; Guillette, Louis J; Zhu, Cairong; Wise, John Pierce; Wise, John Pierce

    2016-02-01

    Metals are a common pollutant in the aquatic ecosystem. With global climate change, these levels are anticipated to rise as lower pH levels allow sediment bound metals to be released. The American alligator (Alligator mississippiensis) is an apex predator in the aquatic ecosystem and is considered a keystone species; as such it serves as a suitable monitor for localized pollution. One metal of increasing concern is hexavalent chromium (Cr(VI)). It is present in the aquatic environment and is a known human carcinogen and reproductive toxicant. We measured the cytotoxicity and genotoxicity of Cr(VI) in American alligator cells derived from scute tissue. We found that particulate and soluble Cr(VI) are both cytotoxic and genotoxic to alligator cells in a concentration-dependent manner. These data suggest that alligators may be used as a model for assessing the effects of environmental Cr(VI) contamination as well as for other metals of concern. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. 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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Fish distributions in the Rondegat River, Cape Floristic Region ...

    African Journals Online (AJOL)

    Alien fishes are considered the most serious threat to native headwater stream fishes in South Africa. A 4 km reach of the Rondegat River is the first section of a South African river to be rehabilitated through the attempted removal of alien fish by using the piscicide rotenone. The objectives of the current study were to ...

  16. Concentrations of trace elements in American alligators (Alligator mississippiensis) from Florida, USA.

    Science.gov (United States)

    Horai, Sawako; Itai, Takaaki; Noguchi, Takako; Yasuda, Yusuke; Adachi, Haruki; Hyobu, Yuika; Riyadi, Adi S; Boggs, Ashley S P; Lowers, Russell; Guillette, Louis J; Tanabe, Shinsuke

    2014-08-01

    Concentrations of 28 trace elements (Li, Mg, Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Mo, Ag, Cd, In, Sn, Sb, Cs, Tl, Hg, Pb, and Bi) in the livers of juvenile and adult American alligators inhabiting two central Florida lakes, Lake Apopka (LA), and Lake Woodruff National Wildlife Refuge (LW) and one lagoon population located in Merritt Island National Wildlife Refuge (MINWR; NASA), were determined. In juveniles from MINWR, concentrations of nine elements (Li, Fe, Ni, Sr, In, Sb, Hg, Pb and Bi) were significantly higher, whereas six elements (V, Fe, As, Sr, Hg and Bi) were elevated in adults (pLA, LW and MINWR were 1770 μg g(-1) DW, 3690 μg g(-1) DW and 5250 μg g(-1) DW, respectively. More than half of the adult specimens from LW and MINWR exhibited elevated hepatic Fe concentrations that exceed the threshold value for toxic effects in donkey, red deer and human. These results prompted us to express our concern on possible exposure and health effects in American alligators by some trace elements derived from NASA activities. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Feeding alters blood flow patterns in the American alligator (Alligator mississippiensis).

    Science.gov (United States)

    Findsen, Anders; Crossley, Dane A; Wang, Tobias

    2018-01-01

    The crocodilian cardiovascular design with a four-chambered heart and a left aorta that emerge from the right ventricle allows blood to be shunted away from the lungs, a right-to-left (R-L) shunt. The adaptive significance of this R-L shunt remains both poorly understood and controversial with particular debate on its putative role during digestion. Here we measure blood flow patterns in the right aorta (RAo), left aorta (LAo) and the coeliac artery (CoA) of undisturbed American alligators (Alligator mississippiensis) during fasting and throughout most of the digestive period. Digestion doubled blood flow in the RAo (10.1±0.9 to 20.7±1.5mlmin -1 kg -1 ), whereas LAo increased approximately 3-fold (3.8±0.6 to 12.2±2.1mlmin -1 kg -1 ). Blood flow in the CoA increased more than four-fold during digestion (3.0±0.6 to 13.3±1.6mlmin -1 kg -1 ). The rise in blood flows was achieved by a doubling of heart rate (18.5±3.3 to 37.8±3.6mlmin -1 kg -1 ). Maximal flows measured in all arteries and heart rate occurred in the first hour of the postprandial period and continued for the next 7h. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. The Pleistocene rivers of the English Channel region

    Science.gov (United States)

    Antoine, Pierre; Coutard, Jean-Pierre; Gibbard, Philip; Hallegouet, Bernard; Lautridou, Jean-Pierre; Ozouf, Jean-Claude

    2003-02-01

    The Pleistocene history of river systems that enter the English Channel from northern France and southern England is reviewed. During periods of low sea-level (cold stages) these streams were tributaries of the Channel River. In southern England the largest, the River Solent, is an axial stream that has drained the Hampshire Basin from the Early Pleistocene or late Pliocene. Other streams of southern England may be of similar antiquity but their records are generally short and their sedimentary history have been destroyed, as in northern Brittany, by coastal erosion and valley deepening as a consequence of tectonic uplift. In northern France, the Seine and Somme rivers have very well developed terrace systems recording incision that began at around 1 Ma. The uplift rate, deduced from the study of these terrace systems, is of 55 to 60 m myr-1 since the end of the Early Pleistocene. Generally the facies and sedimentary structures indicate that the bulk of the deposits in these rivers accumulated in braided river environments under periglacial climates in all the area around the Channel. Evolution of the rivers reflects their responses to climatic change, local geological structure and long-term tectonic activity. In this context the Middle Somme valley is characterised by a regular pattern in which incision occurs at the beginning of each glacial period within a general background of uplift. Nevertheless the response of the different rivers to climatic variations, uplift and sea-level changes is complex and variable according to the different parts of the river courses.

  19. Seasonal Variation of Total Mercury Burden in the American Alligator (Alligator Mississippiensis) at Merritt Island National Wildlife Refuge (MINWR), Florida

    Science.gov (United States)

    Nilsen, Frances M.; Dorsey, Jonathan E.; Long, Stephen E.; Schock, Tracey B.; Bowden, John A.; Lowers, Russell H.; Guillette, Louis J., Jr.

    2016-01-01

    Seasonal variation of mercury (Hg) is not well studied in free-ranging wildlife. Atmospheric deposition patterns of Hg have been studied in detail and have been modeled for both global and specific locations with great accuracy and correlates to environment impact. However, monitoring these trends in wildlife is complicated due to local environmental parameters (e.g., rainfall, humidity, pH, bacterial composition) that can affect the transformation of atmospheric Hg to the biologically available forms. Here, we utilized an abundant and healthy population of American alligators (Alligator mississippiensis) at Merritt Island National Wildlife Refuge (MINWR), FL, and assessed Hg burden in whole blood samples over a span of 7 years (2007 2014; n 174) in an effort to assess seasonal variation of total [Hg]. While the majority of this population is assumed healthy, 18 individuals with low body mass indices (BMI, defined in this study) were captured throughout the 7 year sampling period. These individual alligators exhibited [Hg] that were not consistent with the observed overall seasonal [Hg] variation, and were statistically different from the healthy population of alligators. The alligators with low BMI had elevated concentrations of Hg compared to their age/sex/season matched counterparts with normal BMI. Statistically significant differences were found between the winter and spring seasons for animals with normal BMI. The data in this report supports the conclusion that organismal total [Hg] do fluctuate directly with seasonal deposition rates as well as other seasonal environmental parameters, such as average rainfall and prevailing wind direction. This study highlights the unique environment of MINWR to permit annual assessment of apex predators, such as the American alligator, to determine detailed environmental impact of contaminants of concern.

  20. River water quality in the northern sugarcane-producing regions of ...

    African Journals Online (AJOL)

    2011-02-16

    Feb 16, 2011 ... Sugarcane production in South Africa occurs exclusively in the eastern regions of ... transboundary rivers, making their management internation- ...... KOEGELENBERG FH (2004) Irrigation User's Manual – Chapter 5: Water.

  1. Process analysis of regional aerosol pollution during spring in the Pearl River Delta region, China

    Science.gov (United States)

    Fan, Qi; Lan, Jing; Liu, Yiming; Wang, Xuemei; Chan, Pakwai; Hong, Yingying; Feng, Yerong; Liu, Yexin; Zeng, Yanjun; Liang, Guixiong

    2015-12-01

    A numerical simulation analysis was performed for three air pollution episodes in the Pearl River Delta (PRD) region during March 2012 using the third-generation air quality modeling system Models-3/CMAQ. The results demonstrated that particulate matter was the primary pollutant for all three pollution episodes and was accompanied by relatively low visibility in the first two episodes. Weather maps indicate that the first two episodes occurred under the influence of warm, wet southerly air flow systems that led to high humidity throughout the region. The liquid phase reaction of gaseous pollutants resulted in the generation of fine secondary particles, which were identified as the primary source of pollution in the first two episodes. The third pollution episode occurred during a warming period following a cold front. Relative humidity was lower during this episode, and coarse particles were the major pollution contributor. Results of process analysis indicated that emissions sources, horizontal transport and vertical transport were the primary factors affecting pollutant concentrations within the near-surface layer during all three episodes, while aerosol processes, cloud processes, horizontal transport and vertical transport had greater influence at approximately 900 m above ground. Cloud processes had a greater impact during the first two pollution episodes because of the higher relative humidity. In addition, by comparing pollution processes from different cities (Guangzhou and Zhongshan), the study revealed that the first two pollution episodes were the result of local emissions within the PRD region and transport between surrounding cities, while the third episode exhibited prominent regional pollution characteristics and was the result of regional pollutant transport.

  2. Alligator Rivers Analogue project. Radionuclide transport. Final Report - Volume 14

    International Nuclear Information System (INIS)

    Golian, C.; Lever, D.A.; Baker, A.J.; Connell, L.D.; Bennett, D.G.; Read, D.; Lindgreen, M.; Pers, K.; Skagius, K.; Murakami, T.; Ohnuki, T.

    1992-01-01

    The Koongarra orebody and its associated dispersion fan are examined as a geological analogue for the transport of radionuclides from waste repositories. The aim is to build a consistent picture of the transport that has been taking place in the orebody and the important processes controlling the retardation of uranium series isotopes and to test models of radionuclide transport. A particularly distinctive feature of the Koongarra system is the strong seasonal dependence of the groundwater flow. However, the Koongarra system is similar to a radioactive waste disposal system in that mobilization of uranium is taking place as a result of the infiltration of groundwaters that are in gross chemical disequilibrium with the mineralogy of the primary ore body. There are considerable differences between the Koongarra uranium orebody and a radioactive waste repository, particularly a deep waste repository. The Koongarra system is shallow, affected by seasonal hydrogeological changes as well as climatic variations on a longer timescale and transport is taking place in a zone of active weathering. Some of these features make the Koongarra system harder to characterise than a deep repository. However, there are nevertheless many analogies between the processes occurring at Koongarra and those occurring around a deep or shallow waste repository. The difficulties encountered because of the heterogeneity of the Koongarra weathered zone mirror those to be addressed in assessing radionuclide transport in repository systems. The 234 U/ 238 U activity ratios in rock samples from the dispersion fan decrease in the direction of groundwater transport, whereas in many other systems it has been reported that 234 U is preferentially mobile relative to 238 U (Osmond and Cowart, 1982; Osmond et al., 1983). As most uranium resides in the rock rather than in the groundwater, the net recoil flux of uranium daughter radionuclides is usually from the rock to the groundwater, thus leading to ( 234 U/ 238 U) r less than one. Other models explain the observations by invoking the presence of a phase in which 234 Th is irreversibly fixed

  3. Alligator Rivers Analogue project. Geophysics, petrophysics and structure

    International Nuclear Information System (INIS)

    Emerson, D.W.; Mills, K.J.; Hallett, M.S.; Cao, L.Q.; Miyakawa, K.

    1992-01-01

    The geophysical and geological field work at Koongarra (including borehole core logging) showed that the site itself is a folded, faulted, variably fractured Precambrian psammitic and pelitic schist sequence with a quasi-horizontal weathered zone superimposed on the steeply dipping rock fabric. The site is flanked by a high resistivity younger sandstone unit to the northwest and by a magnetic amphibolite/ferricrete sequence to the far southeast. The data interpretations elicited the essential structural and broad lithological elements. Gravity, magnetic and electrical laboratory and field studies confirmed a broad folded fractured sequence of dipping layered host rocks weathered in their upper parts and trending in a southwest-northeast direction. Qualitatively interpreted anomalies indicated the trend of the main groundwater movement to the south where dolomites are thought to act as a sink. These drainage features have SP, resistivity and radiometric expression. The roles of the Kombolgie Sandstone as a source of water and the Koongarra Fault as a barrier or otherwise were not established owing to the lack of sufficient samples for testing and also on account of the difficulty of geophysical access over the site's rugged escarpment. 40 refs., 13 tabs., 69 figs

  4. Alligator Rivers analogue project. Final Report. Volume 8

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-12-31

    This volume contains a description of the distribution of minerals and elements at Koongarra, including the distribution of radionuclides. The Koongarra orebody is situated 225 km east of Darwin in the Northern Territory of Australia. The zone of primary uranium mineralisation has been intersected by weathering conditions, and this has resulted in the formation of a secondary ore zone and dispersion fan in the weathered zone. The uranium distribution over the site was investigated to determine the extent and direction of uranium migration from the primary uranium mineralisation. The depth patterns of uranium concentration were also investigated to elucidate depths. The distribution of elements, rock and minerals, and how they may affect uranium mobility, or indicate interactions between uranium and solid phases, were considered. Multi-elemental analyses were carried out on many samples to provide basic concentration data about various geochemically significant elements, and to elucidate how the elements interact with one another, the solid substrate and the groundwater. This included the analysis of bulk rock samples, visually distinct sub-samples, different particle sizes and chemically defined phases. Similarly, mineralogical data supplied information on the substrate reacting with the groundwater. Extensive studies were undertaken to elucidate the form of uranium in the weathered zones. These involved optical and electron microscopy studies and auto-radiography. Spatial trends of uranium series disequilibria in bulk rock, secondary uranium minerals and different chemically defined phases were analysed. These give information about uranium deposition and leaching, the evolution of the dispersion fan, the roles and relative importance of different mineralogical phases and processes involved in the retardation of radionuclides. 157 refs., 31 tabs., 87 figs.

  5. 75 FR 34365 - Safety Zone, Alligator River, NC

    Science.gov (United States)

    2010-06-17

    ... Guard and local law enforcement vessels will also provide actual notice to mariners. Under 5 U.S.C. 553... Gunite Construction Company of Cambridge, MD to perform bridge maintenance on the U.S. Highway 64 Swing... section 213(a) of the Small Business Regulatory Enforcement Fairness Act of 1996 (Public Law 104-121), we...

  6. Alligator Rivers Analogue project. Radionuclide transport. Final Report - Volume 14

    Energy Technology Data Exchange (ETDEWEB)

    Golian, C [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia); Lever, D A; Baker, A J; Connell, L D [AEA Decommissioning and Radwaste, Harwell (United Kingdom); Bennett, D G; Read, D [WS Atkins Science and Technology Epsom Surrey (United Kingdom); Lindgreen, M; Pers, K; Skagius, K [Kemakta Consultants co., Stockholm (Sweden); Murakami, T; Ohnuki, T [Japan Atomic Energy Research Institute, Tokai-mura, IBARAKI (Japan)

    1993-12-31

    The Koongarra orebody and its associated dispersion fan are examined as a geological analogue for the transport of radionuclides from waste repositories. The aim is to build a consistent picture of the transport that has been taking place in the orebody and the important processes controlling the retardation of uranium series isotopes and to test models of radionuclide transport. A particularly distinctive feature of the Koongarra system is the strong seasonal dependence of the groundwater flow. However, the Koongarra system is similar to a radioactive waste disposal system in that mobilization of uranium is taking place as a result of the infiltration of groundwaters that are in gross chemical disequilibrium with the mineralogy of the primary ore body. There are considerable differences between the Koongarra uranium orebody and a radioactive waste repository, particularly a deep waste repository. The Koongarra system is shallow, affected by seasonal hydrogeological changes as well as climatic variations on a longer timescale and transport is taking place in a zone of active weathering. Some of these features make the Koongarra system harder to characterise than a deep repository. However, there are nevertheless many analogies between the processes occurring at Koongarra and those occurring around a deep or shallow waste repository. The difficulties encountered because of the heterogeneity of the Koongarra weathered zone mirror those to be addressed in assessing radionuclide transport in repository systems. The {sup 234}U/{sup 238}U activity ratios in rock samples from the dispersion fan decrease in the direction of groundwater transport, whereas in many other systems it has been reported that {sup 234}U is preferentially mobile relative to {sup 238}U (Osmond and Cowart, 1982; Osmond et al., 1983). As most uranium resides in the rock rather than in the groundwater, the net recoil flux of uranium daughter radionuclides is usually from the rock to the groundwater, thus leading to ({sup 234}U/{sup 238}U){sub r} less than one. Other models explain the observations by invoking the presence of a phase in which {sup 234}Th is irreversibly fixed

  7. Alligator Rivers Analogue project. Uranium sorption. Final Report - Volume 13

    International Nuclear Information System (INIS)

    Waite, T.D.; Payne, T.E.; Davis, J.A.; Sekine, K.

    1992-01-01

    In this volume, the results of studies of uranium sorption (adsorption and desorption) to both single, well-defined mineral phases, and to selected natural (Koongarra) substrates are reported. The single phases included the amorphous iron oxide ferrihydrite, crystalline silica and two naturally occurring kaolinites, KGa-1 and Nichika. The surface properties of these materials were rigorously defined, and adsorption studies were conducted over a range of solution pH, ionic strength, carbonate content, adsorbent and adsorbate concentrations, and in the presence of uranium complexants and (potentially) competing adsorbates (such as phosphate and fluoride). The results of these studies were modelled using the 'surface complexation' approach, with a diffuse layer description of the electrical double layer. The impacts of mineral phase transformations (specifically the aging of amorphous ferrihydrite to more crystalline forms) on the uptake and desorption of uranium are also reported. The amount of data obtained in this study, with a number of experimental parameters being varied over a wide range, has enabled more confidence to be placed in the modelling results. The derived model for ferrihydrite adequately accounts for the effect on U sorption of a number of parameters, most notably pH, pCO 2 and total U present. Few (if any) of the models previously proposed are adequate in this respect. While the modelling of the data for the natural substrates is not as advanced, the U sorption data on the natural substrates show similar features to the U sorption on the model substrates. This suggests that the insights obtained in the modelling of the data for ferrihydrite will be valuable in deriving a model for the more complex natural substrates

  8. Alligator Rivers Analogue project. Uranium sorption. Final Report - Volume 13

    Energy Technology Data Exchange (ETDEWEB)

    Waite, T D; Payne, T E [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia); Davis, J A [United States Geological Survey, Water Resources Division, Menlo Park, CA (United States); Sekine, K [Japan Atomic Energy Research Institute, Tokai-mura, Ibaraki (Japan)

    1993-12-31

    In this volume, the results of studies of uranium sorption (adsorption and desorption) to both single, well-defined mineral phases, and to selected natural (Koongarra) substrates are reported. The single phases included the amorphous iron oxide ferrihydrite, crystalline silica and two naturally occurring kaolinites, KGa-1 and Nichika. The surface properties of these materials were rigorously defined, and adsorption studies were conducted over a range of solution pH, ionic strength, carbonate content, adsorbent and adsorbate concentrations, and in the presence of uranium complexants and (potentially) competing adsorbates (such as phosphate and fluoride). The results of these studies were modelled using the `surface complexation` approach, with a diffuse layer description of the electrical double layer. The impacts of mineral phase transformations (specifically the aging of amorphous ferrihydrite to more crystalline forms) on the uptake and desorption of uranium are also reported. The amount of data obtained in this study, with a number of experimental parameters being varied over a wide range, has enabled more confidence to be placed in the modelling results. The derived model for ferrihydrite adequately accounts for the effect on U sorption of a number of parameters, most notably pH, pCO{sub 2} and total U present. Few (if any) of the models previously proposed are adequate in this respect. While the modelling of the data for the natural substrates is not as advanced, the U sorption data on the natural substrates show similar features to the U sorption on the model substrates. This suggests that the insights obtained in the modelling of the data for ferrihydrite will be valuable in deriving a model for the more complex natural substrates 87 refs., 27 tabs., 56 figs.

  9. Alligator Rivers analogue project. Final Report. Volume 8

    International Nuclear Information System (INIS)

    1992-01-01

    This volume contains a description of the distribution of minerals and elements at Koongarra, including the distribution of radionuclides. The Koongarra orebody is situated 225 km east of Darwin in the Northern Territory of Australia. The zone of primary uranium mineralisation has been intersected by weathering conditions, and this has resulted in the formation of a secondary ore zone and dispersion fan in the weathered zone. The uranium distribution over the site was investigated to determine the extent and direction of uranium migration from the primary uranium mineralisation. The depth patterns of uranium concentration were also investigated to elucidate depths. The distribution of elements, rock and minerals, and how they may affect uranium mobility, or indicate interactions between uranium and solid phases, were considered. Multi-elemental analyses were carried out on many samples to provide basic concentration data about various geochemically significant elements, and to elucidate how the elements interact with one another, the solid substrate and the groundwater. This included the analysis of bulk rock samples, visually distinct sub-samples, different particle sizes and chemically defined phases. Similarly, mineralogical data supplied information on the substrate reacting with the groundwater. Extensive studies were undertaken to elucidate the form of uranium in the weathered zones. These involved optical and electron microscopy studies and auto-radiography. Spatial trends of uranium series disequilibria in bulk rock, secondary uranium minerals and different chemically defined phases were analysed. These give information about uranium deposition and leaching, the evolution of the dispersion fan, the roles and relative importance of different mineralogical phases and processes involved in the retardation of radionuclides. 157 refs., 31 tabs., 87 figs

  10. Alligator Rivers Analogue project. Radionuclide transport. Final Report - Volume 14

    Energy Technology Data Exchange (ETDEWEB)

    Golian, C. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia); Lever, D.A.; Baker, A.J.; Connell, L.D. [AEA Decommissioning and Radwaste, Harwell (United Kingdom); Bennett, D.G.; Read, D. [WS Atkins Science and Technology Epsom Surrey (United Kingdom); Lindgreen, M.; Pers, K.; Skagius, K. [Kemakta Consultants co., Stockholm (Sweden); Murakami, T.; Ohnuki, T. [Japan Atomic Energy Research Institute, Tokai-mura, IBARAKI (Japan)

    1992-12-31

    The Koongarra orebody and its associated dispersion fan are examined as a geological analogue for the transport of radionuclides from waste repositories. The aim is to build a consistent picture of the transport that has been taking place in the orebody and the important processes controlling the retardation of uranium series isotopes and to test models of radionuclide transport. A particularly distinctive feature of the Koongarra system is the strong seasonal dependence of the groundwater flow. However, the Koongarra system is similar to a radioactive waste disposal system in that mobilization of uranium is taking place as a result of the infiltration of groundwaters that are in gross chemical disequilibrium with the mineralogy of the primary ore body. There are considerable differences between the Koongarra uranium orebody and a radioactive waste repository, particularly a deep waste repository. The Koongarra system is shallow, affected by seasonal hydrogeological changes as well as climatic variations on a longer timescale and transport is taking place in a zone of active weathering. Some of these features make the Koongarra system harder to characterise than a deep repository. However, there are nevertheless many analogies between the processes occurring at Koongarra and those occurring around a deep or shallow waste repository. The difficulties encountered because of the heterogeneity of the Koongarra weathered zone mirror those to be addressed in assessing radionuclide transport in repository systems. The {sup 234}U/{sup 238}U activity ratios in rock samples from the dispersion fan decrease in the direction of groundwater transport, whereas in many other systems it has been reported that {sup 234}U is preferentially mobile relative to {sup 238}U (Osmond and Cowart, 1982; Osmond et al., 1983). As most uranium resides in the rock rather than in the groundwater, the net recoil flux of uranium daughter radionuclides is usually from the rock to the groundwater, thus leading to ({sup 234}U/{sup 238}U){sub r} less than one. Other models explain the observations by invoking the presence of a phase in which {sup 234}Th is irreversibly fixed

  11. Alligator Rivers analogue project. Final Report. Volume 8

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1992-12-31

    This volume contains a description of the distribution of minerals and elements at Koongarra, including the distribution of radionuclides. The Koongarra orebody is situated 225 km east of Darwin in the Northern Territory of Australia. The zone of primary uranium mineralisation has been intersected by weathering conditions, and this has resulted in the formation of a secondary ore zone and dispersion fan in the weathered zone. The uranium distribution over the site was investigated to determine the extent and direction of uranium migration from the primary uranium mineralisation. The depth patterns of uranium concentration were also investigated to elucidate depths. The distribution of elements, rock and minerals, and how they may affect uranium mobility, or indicate interactions between uranium and solid phases, were considered. Multi-elemental analyses were carried out on many samples to provide basic concentration data about various geochemically significant elements, and to elucidate how the elements interact with one another, the solid substrate and the groundwater. This included the analysis of bulk rock samples, visually distinct sub-samples, different particle sizes and chemically defined phases. Similarly, mineralogical data supplied information on the substrate reacting with the groundwater. Extensive studies were undertaken to elucidate the form of uranium in the weathered zones. These involved optical and electron microscopy studies and auto-radiography. Spatial trends of uranium series disequilibria in bulk rock, secondary uranium minerals and different chemically defined phases were analysed. These give information about uranium deposition and leaching, the evolution of the dispersion fan, the roles and relative importance of different mineralogical phases and processes involved in the retardation of radionuclides. 157 refs., 31 tabs., 87 figs.

  12. Blow Flies Visiting Decaying Alligators: Is Succession Synchronous or Asynchronous?

    OpenAIRE

    Nelder, Mark P.; McCreadie, John W.; Major, Clinton S.

    2009-01-01

    Succession patterns of adult blow flies (Diptera: Calliphoridae) on decaying alligators were investigated in Mobile (Ala, USA) during August 2002. The most abundant blow fly species visiting the carcasses were Chrysomya rufifacies (Macquart), Cochliomyia macellaria (Fabricus), Chrysomya megacephala (Fabricus), Phormia regina (Meigen), and Lucilia coeruleiviridis (Macquart). Lucilia coeruleiviridis was collected more often during the early stages of decomposition, followed by Chrysomya spp., C...

  13. Effect of aqueous extract of alligator pepper (Zingiberaceae ...

    African Journals Online (AJOL)

    Twenty female and ten male Sprague-Dawley rats of proven fertility from a pilot study were randomly mated in groups of two females and one male. Three days later, female rats in the ... weight gain reduction. Key words: Gestational weight gain, Aqueous Extract, Intra-peritoneal injection, Alligator Pepper, Nutrition.

  14. Alligators and crocodiles as indicators for restoration of Everglades ecosystems

    Science.gov (United States)

    Mazzotti, Frank J.; Best, G. Ronnie; Brandt, Laura A.; Cherkiss, Michael S.; Jeffery, Brian M.; Rice, Kenneth G.

    2009-01-01

    Alligators and crocodiles integrate biological impacts of hydrological operations, affecting them at all life stages through three key aspects of Everglades ecology: (1) food webs, (2) diversity and productivity, and (3) freshwater flow. Responses of crocodilians are directly related to suitability of environmental conditions and hydrologic change. Correlations between biological responses and environmental conditions contribute to an understanding of species' status and trends over time. Positive or negative trends of crocodilian populations relative to hydrologic changes permit assessment of positive or negative trends in restoration. The crocodilian indicator uses monitoring parameters (performance measures) that have been shown to be both effective and efficient in tracking trends. The alligator component uses relative density (reported as an encounter rate), body condition, and occupancy rates of alligator holes; the crocodile component uses juvenile growth and hatchling survival. We hypothesize that these parameters are correlated with hydrologic conditions including depth, duration, timing, spatial extent and water quality. Salinity is a critical parameter in estuarine habitats. Assessments of parameters defined for crocodilian performance measures support these hypotheses. Alligators and crocodiles are the charismatic megafauna of the Everglades. They are both keystone and flagship species to which the public can relate. In addition, the parameters used to track trends are easy to understand. They provide answers to the following questions: How has the number of alligators or crocodiles changed? Are the animals fatter or thinner than they should be? Are the animals in the places (in terms of habitat and geography) where they should be? As surely as there is no other Everglades, no other single species defines the Everglades as does the American alligator. The Everglades is the only place in the world where both alligators and crocodiles exist. Crocodilians

  15. Heavy metal contamination status and source apportionment in sediments of Songhua River Harbin region, Northeast China.

    Science.gov (United States)

    Li, Ning; Tian, Yu; Zhang, Jun; Zuo, Wei; Zhan, Wei; Zhang, Jian

    2017-02-01

    The Songhua River represents one of the seven major river systems in China. It flows through Harbin city with 66 km long, locating in the northern China with a longer winter time. This paper aimed to study concentration distributions, stability, risk assessment, and source apportionment of heavy metals including chromium (Cr), cadmium (Cd), lead (Pb), mercury (Hg), arsenic (As), copper (Cu), zinc (Zn), and nickel (Ni) in 11 selected sections of the Songhua River Harbin region. Results showed that Cr, Cd, Pb, Hg, and As exceeded their respective geochemical background values in sediments of most monitoring sections. Compared with other important rivers and lakes in China, Cr, Hg, Cd, and As pollutions in surface sediments were above medium level. Further analysis of chemical speciation indicated that Cr and As in surface sediments were relatively stable while Pb and Cd were easily bioavailable. Correlation analysis revealed sources of these metals except As might be identical. Pollution levels and ecological risks of heavy metals in surface sediments presented higher in the mainstream region (45° 47.0' N ~ 45° 53.3' N, 126° 37.0' E ~ 126° 42.1' E). Source apportionment found Hejiagou and Ashi River were the main contributors to metal pollution of this region. Thus, anthropogenic activities along the Hejiagou and Ashi River should be restricted in order to protect the Songhua River Harbin region from metal contamination.

  16. Olfactory and solitary chemosensory cells: two different chemosensory systems in the nasal cavity of the American alligator, Alligator mississippiensis

    Directory of Open Access Journals (Sweden)

    Hansen Anne

    2007-08-01

    Full Text Available Abstract Background The nasal cavity of all vertebrates houses multiple chemosensors, either innervated by the Ist (olfactory or the Vth (trigeminal cranial nerve. Various types of receptor cells are present, either segregated in different compartments (e.g. in rodents or mingled in one epithelium (e.g. fish. In addition, solitary chemosensory cells have been reported for several species. Alligators which seek their prey both above and under water have only one nasal compartment. Information about their olfactory epithelium is limited. Since alligators seem to detect both volatile and water-soluble odour cues, I tested whether different sensory cell types are present in the olfactory epithelium. Results Electron microscopy and immunocytochemistry were used to examine the sensory epithelium of the nasal cavity of the American alligator. Almost the entire nasal cavity is lined with olfactory (sensory epithelium. Two types of olfactory sensory neurons are present. Both types bear cilia as well as microvilli at their apical endings and express the typical markers for olfactory neurons. The density of these olfactory neurons varies along the nasal cavity. In addition, solitary chemosensory cells innervated by trigeminal nerve fibres, are intermingled with olfactory sensory neurons. Solitary chemosensory cells express components of the PLC-transduction cascade found in solitary chemosensory cells in rodents. Conclusion The nasal cavity of the American alligator contains two different chemosensory systems incorporated in the same sensory epithelium: the olfactory system proper and solitary chemosensory cells. The olfactory system contains two morphological distinct types of ciliated olfactory receptor neurons.

  17. Ecological restoration and effect investigation of a river wetland in a semi-arid region, China

    Science.gov (United States)

    Xu, S.; Jiang, X.; Liu, Y.; Fu, Y.; Zhao, Q.

    2015-05-01

    River wetlands are heavily impacted by human intervention. The degradation and loss of river wetlands has made the restoration of river ecosystems a top priority. How to rehabilitate rivers and their services has been a research focus. The main goal of it is to restore the river wetland ecosystems with ecological methods. The Gudong River was selected as a study site in Chaoyang city in this study. Based on the analysis of interference factors in the river wetland degradation, a set of restoration techniques were proposed and designed for regional water level control, including submerged dikes, ecological embankments, revegetation and dredging. The restoration engineering has produced good results in water quality, eco-environment, and landscape. Monthly reports of the Daling River show that the water quality of Gudong River was better than Grade III in April 2013 compared with Grade V in May 2012. The economic benefit after restoration construction is 1.71 million RMB per year, about 1.89 times that before. The ratio of economic value, social value and eco-environmental value is 1:4:23.

  18. River reach classification for the Greater Mekong Region at high spatial resolution

    Science.gov (United States)

    Ouellet Dallaire, C.; Lehner, B.

    2014-12-01

    River classifications have been used in river health and ecological assessments as coarse proxies to represent aquatic biodiversity when comprehensive biological and/or species data is unavailable. Currently there are no river classifications or biological data available in a consistent format for the extent of the Greater Mekong Region (GMR; including the Irrawaddy, the Salween, the Chao Praya, the Mekong and the Red River basins). The current project proposes a new river habitat classification for the region, facilitated by the HydroSHEDS (HYDROlogical SHuttle Elevation Derivatives at multiple Scales) database at 500m pixel resolution. The classification project is based on the Global River Classification framework relying on the creation of multiple sub-classifications based on different disciplines. The resulting classes from the sub-classification are later combined into final classes to create a holistic river reach classification. For the GMR, a final habitat classification was created based on three sub-classifications: a hydrological sub-classification based only on discharge indices (river size and flow variability); a physio-climatic sub-classification based on large scale indices of climate and elevation (biomes, ecoregions and elevation); and a geomorphological sub-classification based on local morphology (presence of floodplains, reach gradient and sand transport). Key variables and thresholds were identified in collaboration with local experts to ensure that regional knowledge was included. The final classification is composed 54 unique final classes based on 3 sub-classifications with less than 15 classes each. The resulting classifications are driven by abiotic variables and do not include biological data, but they represent a state-of-the art product based on best available data (mostly global data). The most common river habitat type is the "dry broadleaf, low gradient, very small river". These classifications could be applied in a wide range of

  19. Contamination with retinoic acid receptor agonists in two rivers in the Kinki region of Japan.

    Science.gov (United States)

    Inoue, Daisuke; Nakama, Koki; Sawada, Kazuko; Watanabe, Taro; Takagi, Mai; Sei, Kazunari; Yang, Min; Hirotsuji, Junji; Hu, Jianying; Nishikawa, Jun-ichi; Nakanishi, Tsuyoshi; Ike, Michihiko

    2010-04-01

    This study was conducted to investigate the agonistic activity against human retinoic acid receptor (RAR) alpha in the Lake Biwa-Yodo River and the Ina River in the Kinki region of Japan. To accomplish this, a yeast two-hybrid assay was used to elucidate the spatial and temporal variations and potential sources of RARalpha agonist contamination in the river basins. RARalpha agonistic activity was commonly detected in the surface water samples collected along two rivers at different periods, with maximum all-trans retinoic acid (atRA) equivalents of 47.6 ng-atRA/L and 23.5 ng-atRA/L being observed in Lake Biwa-Yodo River and Ina River, respectively. The results indicated that RARalpha agonists are always present and widespread in the rivers. Comparative investigation of RARalpha and estrogen receptor alpha agonistic activities at 20 stations along each river revealed that the spatial variation pattern of RARalpha agonist contamination was entirely different from that of the estrogenic compound contamination. This suggests that the effluent from municipal wastewater treatment plants, a primary source of estrogenic compounds, seemed not to be the cause of RARalpha agonist contamination in the rivers. Fractionation using high performance liquid chromatography (HPLC) directed by the bioassay found two bioactive fractions from river water samples, suggesting the presence of at least two RARalpha agonists in the rivers. Although a trial conducted to identify RARalpha agonists in the major bioactive fraction was not completed as part of this study, comparison of retention times in HPLC analysis and quantification with liquid chromatography-mass spectrometry analysis revealed that the major causative contaminants responsible for the RARalpha agonistic activity were not RAs (natural RAR ligands) and 4-oxo-RAs, while 4-oxo-RAs were identified as the major RAR agonists in sewage in Beijing, China. These findings suggest that there are unknown RARalpha agonists with high

  20. Effects of long-term corticosterone implants on growth and immune function in juvenile alligators, Alligator mississippiensis.

    Science.gov (United States)

    Morici, L A; Elsey, R M; Lance, V A

    1997-10-01

    Sixty juvenile alligators were implanted subcutaneously with slow release pellets of corticosterone or placebo. Alligators were divided into five different groups such that each group received a different dose. A blood sample was taken prior to and 4 days after the implants were in place to measure hormone levels. Additional blood samples were collected at 1 month and 3 months. At 4 days corticosterone levels ranged from 3,400 ng/ml in the group treated with the high dose to 40 ng/ml in the group implanted with the low dose. The extremely high dose caused 40% mortality within 4 weeks. It was evident that the pellets did not release the hormone for the expected 90 days. Circulating levels of corticosterone were back to baseline levels by 3 months. Hormone levels achieved at 4 days were a reliable predictor of subsequent growth. Rate of growth was negatively correlated with plasma corticosterone at 4 days (r2 = 0.711) and at 1 month (r2 = 0.544) posttreatment. Differential white blood cell counts performed after 1 month of treatment showed a clear effect of the implant. Alligators treated with corticosterone had decreased percentages of lymphocytes, eosinophils, and basophils and had a higher heterophil/lymphocyte (H/L) ratio than the placebo group. Furthermore, histological examination of the spleen revealed a significant depletion of lymphoid cells in alligators treated with the highest dose of hormone. The results from this study demonstrate that exogenous corticosterone can mimic the effects of prolonged stress in juvenile alligators.

  1. Regional Sediment Budget of the Columbia River Littoral Cell, USA

    Science.gov (United States)

    Buijsman, Maarten C.; Sherwood, C.R.; Gibbs, A.E.; Gelfenbaum, G.; Kaminsky, G.M.; Ruggiero, P.; Franklin, J.

    2002-01-01

    Summary -- In this Open-File Report we present calculations of changes in bathymetric and topographic volumes for the Grays Harbor, Willapa Bay, and Columbia River entrances and the adjacent coasts of North Beach, Grayland Plains, Long Beach, and Clatsop Plains for four intervals: pre-jetty - 1920s (Interval 1), 1920s - 1950s (Interval 2), 1950s - 1990s (Interval 3), and 1920s 1990s (Interval 4). This analysis is part of the Southwest Washington Coastal Erosion Study (SWCES), the goals of which are to understand and predict the morphologic behavior of the Columbia River littoral cell on a management scale of tens of kilometers and decades. We obtain topographic Light Detection and Ranging (LIDAR) data from a joint project by the U.S. Geological Survey (USGS), National Oceanic and Atmospheric Administration (NOAA), National Aeronautic and Space Administration (NASA), and the Washington State Department of Ecology (DOE) and bathymetric data from the U.S. Coast and Geodetic Survey (USC&GS), U.S. Army Corps of Engineers (USACE), USGS, and the DOE. Shoreline data are digitized from T-Sheets and aerial photographs from the USC&GS and National Ocean Service (NOS). Instead of uncritically adjusting each survey to NAVD88, a common vertical land-based datum, we adjust some surveys to produce optimal results according to the following criteria. First, we minimize offsets in overlapping surveys within the same era, and second, we minimize bathymetric changes (relative to the 1990s) in deep water, where we assume minimal change has taken place. We grid bathymetric and topographic datasets using kriging and triangulation algorithms, calculate bathymetric-change surfaces for each interval, and calculate volume changes within polygons that are overlaid on the bathymetric-change surfaces. We find similar morphologic changes near the entrances to Grays Harbor and the Columbia River following jetty construction between 1898 and 1916 at the Grays Harbor entrance and between 1885 and

  2. Groundwater Discharges to Rivers in the Western Canadian Oil Sands Region

    Science.gov (United States)

    Ellis, J.; Jasechko, S.

    2016-12-01

    Groundwater discharges into rivers impacts the movement and fate of nutrients and contaminants in the environment. Understanding groundwater-surface water interactions is especially important in the western Canadian oil sands, where groundwater contamination risks are elevated and baseline water chemistry data is lacking, leading to substantial uncertainties about anthropogenic influences on local river quality. High salinity groundwater springs sourced from deep aquifers, comprised of Pleistocene-aged glacial meltwater, are known to discharge into many rivers in the oil sands. Understanding connections between deep aquifers and surficial waterways is important in order to determine natural inputs into these rivers and to assess the potential for injected wastewater or oil extraction fluids to enter surface waters. While these springs have been identified, their spatial distribution along rivers has not been fully characterized. Here we present river chemistry data collected along a number of major river corridors in the Canadian oil sands region. We show that saline groundwater springs vary spatially along the course of these rivers and tend to be concentrated where the rivers incise Devonian- or Cretaceous-aged aquifers along an evaporite dissolution front. Our results suggest that water sourced from Devonian aquifers may travel through bitumen-bearing Cretaceous units and discharge into local rivers, implying a strong groundwater-surface water connection in specialized locations. These findings indicate that oil sands process-affected waters that are injected at depth have the potential to move through these aquifers and reach the rivers at the surface at some time in the future. Groundwater-surface water interactions remain key to understanding the risks oil sands activities pose to aquatic ecosystems and downstream communities.

  3. Regional scale groundwater modelling study for Ganga River basin

    Science.gov (United States)

    Maheswaran, R.; Khosa, R.; Gosain, A. K.; Lahari, S.; Sinha, S. K.; Chahar, B. R.; Dhanya, C. T.

    2016-10-01

    Subsurface movement of water within the alluvial formations of Ganga Basin System of North and East India, extending over an area of 1 million km2, was simulated using Visual MODFLOW based transient numerical model. The study incorporates historical groundwater developments as recorded by various concerned agencies and also accommodates the role of some of the major tributaries of River Ganga as geo-hydrological boundaries. Geo-stratigraphic structures, along with corresponding hydrological parameters,were obtained from Central Groundwater Board, India,and used in the study which was carried out over a time horizon of 4.5 years. The model parameters were fine tuned for calibration using Parameter Estimation (PEST) simulations. Analyses of the stream aquifer interaction using Zone Budget has allowed demarcation of the losing and gaining stretches along the main stem of River Ganga as well as some of its principal tributaries. From a management perspective,and entirely consistent with general understanding, it is seen that unabated long term groundwater extraction within the study basin has induced a sharp decrease in critical dry weather base flow contributions. In view of a surge in demand for dry season irrigation water for agriculture in the area, numerical models can be a useful tool to generate not only an understanding of the underlying groundwater system but also facilitate development of basin-wide detailed impact scenarios as inputs for management and policy action.

  4. Blow Flies Visiting Decaying Alligators: Is Succession Synchronous or Asynchronous?

    Directory of Open Access Journals (Sweden)

    Mark P. Nelder

    2009-01-01

    Full Text Available Succession patterns of adult blow flies (Diptera: Calliphoridae on decaying alligators were investigated in Mobile (Ala, USA during August 2002. The most abundant blow fly species visiting the carcasses were Chrysomya rufifacies (Macquart, Cochliomyia macellaria (Fabricus, Chrysomya megacephala (Fabricus, Phormia regina (Meigen, and Lucilia coeruleiviridis (Macquart. Lucilia coeruleiviridis was collected more often during the early stages of decomposition, followed by Chrysomya spp., Cochliomyia macellaria, and Phormia regina in the later stages. Lucilia coeruleiviridis was the only synchronous blow fly on the three carcasses; other blow fly species exhibited only site-specific synchrony. Using dichotomous correlations and analyses of variance, we demonstrated that blow fly-community succession was asynchronous among three alligators; however, Monte Carlo simulations indicate that there was some degree of synchrony between the carcasses.

  5. Percutaneous antegrade ureteric stent removal using a rigid alligator forceps.

    LENUS (Irish Health Repository)

    Given, M F

    2008-12-01

    To evaluate the safety and efficacy of percutaneous antegrade ureteric stent removal using a rigid alligator forceps. Twenty patients were included in our study. Indications for ureteric stent insertion included stone disease (n = 7), malignancy (n = 8) and transplant anastomotic strictures (n = 5). Stent retrieval was carried out for proximal stent placement\\/migration in seven patients and encrustation in the remaining 13. Twenty-two stents were successfully retrieved in 20 patients. There was one technical failure (5%). There were no major complications. We had four minor complications, which included nephrostomy site pain (n = 2), periprocedural sepsis (n = 1) and a small urinoma (n = 1). All patients settled with conservative management. Percutaneous radiologically guided antegrade ureteric stent removal with an alligator forceps is safe and effective, particularly when initial surgical removal has failed.

  6. Water Hyacinths and Alligator Weeds for Final Filtration of Sewage

    Science.gov (United States)

    Wolverton, B. C.; Mcdonald, R. C.; Gordon, J.

    1976-01-01

    The potential of water hyacinths (Eichhornia crassipes) (Mart.) Solms and alligator weeds (Alternanthera philoxerides) (Mart.) Griesb. as secondary and tertiary filtration systems for domestic sewage was demonstrated. These two vascular aquatic plants reduced the suspended solids, total Kjeldahl nitrogen, total phosphorus, BOD sub 5, and total organic carbon levels in domestic sewage from 60 percent to 98 percent within a two week period. These plants grown in domestic sewage were also free of toxic levels of trace heavy metals.

  7. Geologic map of the west-central Buffalo National River region, northern Arkansas

    Science.gov (United States)

    Hudson, Mark R.; Turner, Kenzie J.

    2014-01-01

    This map summarizes the geology of the west-central Buffalo National River region in the Ozark Plateaus region of northern Arkansas. Geologically, the region lies on the southern flank of the Ozark dome, an uplift that exposes oldest rocks at its center in Missouri. Physiographically, the map area spans the Springfield Plateau, a topographic surface generally held up by Mississippian cherty limestone and the higher Boston Mountains to the south, held up by Pennsylvanian rocks. The Buffalo River flows eastward through the map area, enhancing bedrock erosion of an approximately 1,600-ft- (490-m-) thick sequence of Ordovician, Mississippian, and Pennsylvanian carbonate and clastic sedimentary rocks that have been mildly deformed by a series of faults and folds. Quaternary surficial units are present as alluvial deposits along major streams, including a series of terrace deposits from the Buffalo River, as well as colluvium and landslide deposits mantling bedrock on hillslopes.

  8. Savannah River Region: Transition between the Gulf and Atlantic Coastal Plains. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Zullo, V.A.; Harris, W.B.; Price, V. [eds.

    1990-12-31

    The focus of the this conference of Coastal Plains geologists was on the Savannah River region of Georgia and South Carolina, and particularly on the geology of the US Department of Energy`s 300 square mile Savannah River Site (SRS) in western South Carolina. Current geological studies indicate that the Mesozoic-Cenozoic section in the Savannah River region is transitional between that of the Gulf Coastal Plain to the southwest and that of the Atlantic Coastal Plain to the northeast. With the transitional aspect of the region as its theme, the first session was devoted to overviews of Cretaceous and Paleogene geology in the Gulf and Atlantic Coastal Plains. Succeeding presentations and resulting discussions dealt with more specific problems in structural, lithostratigraphic, hydrological, biostratigraphic, and cyclostratigraphic analysis, and of correlation to standard stratigraphic frameworks. For these conference proceedings, individual papers have been processed separately for the Energy Data Base.

  9. Lower Colorado River Geographic Response Plan Web Mapping Service, Region 9, 2012, US EPA Region 9

    Data.gov (United States)

    U.S. Environmental Protection Agency — This map service is comprised of data related to Geographic Response Plans (GRPs) for the Lower Colorado River. Data layers were obtained from nationwide GIS...

  10. Investigations of some regional river systems by INAA and X-ray fluorescence

    International Nuclear Information System (INIS)

    Drazhkovich, R.J.; Kukoch, A.

    1985-01-01

    Distribution of Zn, Hg, Sb, Cr, Fe, Sc and Co has been investigated in materials dissolved and suspended in the rivers Ibar, Zapadna Morava and Kamenica by means of INAA and X-ray fluorescence. Irradiation was made in VKG-channels of RA-nuclear reactor Vincha. Distribution coefficients were calculated, as well as contamination factors for investigated river regional systems in comparison to the uncontaminated water system. Data obtained indicate the possibility of utilization of these two analytical methods for investigation and control of biogeochemical and contamination processes in small regional water systems, especially important for modern studies in life sciences

  11. Macroinvertebrate distribution and aquatic ecology in the Ruoergai (Zoige) Wetland, the Yellow River source region

    Science.gov (United States)

    Zhao, Na; Xu, Mengzhen; Li, Zhiwei; Wang, Zhaoyin; Zhou, Hanmi

    2017-09-01

    The Ruoergai (Zoige) Wetland, the largest plateau peatland in the world, is located in the Yellow River source region. The discharge of the Yellow River increases greatly after flowing through the Ruoergai Wetland. The aquatic ecosystem of the Ruoergai Wetland is crucial to the whole Yellow River basin. The Ruoergai wetland has three main kinds of water bodies: rivers, oxbow lakes, and marsh wetlands. In this study, macroinvertebrates were used as indicators to assess the aquatic ecological status because their assemblage structures indicate long-term changes in environments with high sensitivity. Field investigations were conducted in July, 2012 and in July, 2013. A total of 72 taxa of macroinvertebrates belonging to 35 families and 67 genera were sampled and identified. Insecta was the dominant group in the Ruoergai Basin. The alpha diversity of macroinvertebrates at any single sampling site was low, while the alpha diversity on a basin-wide scale was much higher. Macroinvertebrate assemblages in rivers, oxbow lakes, and marsh wetlands differ markedly. Hydrological connectivity was a primary factor causing the variance of the bio-community. The river channels had the highest alpha diversity of macroinvertebrates, followed by marsh wetlands and oxbow lakes. The density and biomass of Gastropoda, collector filterers, and scrapers increased from rivers to oxbow lakes and then to marsh wetlands. The river ecology was particular in the Ruoergai Wetland with the high beta diversity of macroinvertebrates, the low alpha diversity of macroinvertebrates, and the low taxa richness, density, and biomass of EPT (Ephemeroptera, Plecoptera, Trichoptera). To maintain high alpha diversity of macroinvertebrates macroinvertebrates in the Ruoergai Wetland, moderate connectivity of oxbow lakes and marsh wetlands with rivers and measures to control headwater erosion are both crucial.

  12. Solute geochemistry of the Snake River Plain regional aquifer system, Idaho and eastern Oregon

    International Nuclear Information System (INIS)

    Wood, W.W.; Low, W.H.

    1987-01-01

    Three geochemical methods were used to determine chemical reactions that control solute concentrations in the Snake River Plain regional aquifer system: (1) calculation of a regional solute balance within the aquifer and of mineralogy in the aquifer framework to identify solute reactions, (2) comparison of thermodynamic mineral saturation indices with plausible solute reactions, and (3) comparison of stable isotope ratios of the groundwater with those in the aquifer framework. The geothermal groundwater system underlying the main aquifer system was examined by calculating thermodynamic mineral saturation indices, stable isotope ratios of geothermal water, geothermometry, and radiocarbon dating. Water budgets, hydrologic arguments, and isotopic analyses for the eastern Snake River Plain aquifer system demonstrate that most, if not all, water is of local meteoric and not juvenile or formation origin. Solute balance, isotopic, mineralogic, and thermodynamic arguments suggest that about 20% of the solutes are derived from reactions with rocks forming the aquifer framework. Reactions controlling solutes in the western Snake river basin are believed to be similar to those in the eastern basin but the regional geothermal system that underlies the Snake river Plain contains total dissolved solids similar to those in the overlying Snake River Plain aquifer system but contains higher concentrations of sodium, bicarbonate, silica, fluoride, sulfate, chloride, arsenic, boron, and lithium, and lower concentrations of calcium, magnesium, and hydrogen. 132 refs., 30 figs., 27 tabs

  13. PLASMA STEROID CONCENTRATIONS IN RELATION TO SIZE AND AGE IN JUVENILE ALLIGATORS FROM TWO FLORIDA LAKES.

    Science.gov (United States)

    Previous studies have reported a number of physiological differences among juvenile alligators from two well-studied populations (Lake Apopka and Lake Woodruff) in north central Florida. These studies obtained alligators of similar size from each lake under the assumption that th...

  14. Biomonitoring Heavy Metal Pollution Using an Aquatic Apex Predator, the American Alligator, and Its Parasites

    Science.gov (United States)

    Tellez, Marisa; Merchant, Mark

    2015-01-01

    Monitoring the bioaccumulation of chemical elements within various organismal tissues has become a useful tool to survey current or chronic levels of heavy metal exposure within an environment. In this study, we compared the bioaccumulations of As, Cd, Cu, Fe, Pb, Se, and Zn between the American alligator, Alligator mississippiensis, and its parasites in order to establish their use as bioindicators of heavy metal pollution. Concomitant with these results, we were interested to determine if parasites were more sensitive bioindicators of heavy metals relative to alligators. We found parasites collectively accumulated higher levels of As, Cu, Se, and Zn in comparison to their alligator hosts, whereas Fe, Cd, and Pb concentrations were higher in alligators. Interestingly, Fe levels were significantly greater in intestinal trematodes than their alligator hosts when analyzed independently from other parasitic taxa. Further analyses showed alligator intestinal trematodes concentrated As, Cu, Fe, Se, and Zn at significantly higher levels than intestinal nematodes and parasites from other organs. However, pentastomids also employed the role as a good biomagnifier of As. Interestingly, parasitic abundance decreased as levels of As increased. Stomach and intestinal nematodes were the poorest bioaccumulators of metals, yet stomach nematodes showed their ability to concentrate Pb at orders of magnitude higher in comparison to other parasites. Conclusively, we suggest that parasites, particularly intestinal trematodes, are superior biomagnifiers of As, Cu, Se, and Zn, whereas alligators are likely good biological indicators of Fe, Cd, and Pb levels within the environment. PMID:26555363

  15. Climate Drivers of Spatiotemporal Variability of Precipitation in the Source Region of Yangtze River

    Science.gov (United States)

    Du, Y.; Berndtsson, R.; An, D.; Yuan, F.

    2017-12-01

    Variability of precipitation regime has significant influence on the environment sustainability in the source region of Yangtze River, especially when the vegetation degradation and biodiversity reduction have already occurred. Understanding the linkage between variability of local precipitation and global teleconnection patterns is essential for water resources management. Based on physical reasoning, indices of the climate drivers can provide a practical way of predicting precipitation. Due to high seasonal variability of precipitation, climate drivers of the seasonal precipitation also varies. However, few reports have gone through the teleconnections between large scale patterns with seasonal precipitation in the source region of Yangtze River. The objectives of this study are therefore (1) assessment of temporal trend and spatial variability of precipitation in the source region of Yangtze River; (2) identification of climate indices with strong influence on seasonal precipitation anomalies; (3) prediction of seasonal precipitation based on revealed climate indices. Principal component analysis and Spearman rank correlation were used to detect significant relationships. A feed-forward artificial neural network(ANN) was developed to predict seasonal precipitation using significant correlated climate indices. Different influencing climate indices were revealed for precipitation in each season, with significant level and lag times. Significant influencing factors were selected to be the predictors for ANN model. With correlation coefficients between observed and simulated precipitation over 0.5, the results were eligible to predict the precipitation of spring, summer and winter using teleconnections, which can improve integrated water resources management in the source region of Yangtze River.

  16. Regional effects of agricultural conservation practices on nutrient transport in the Upper Mississippi River Basin

    Science.gov (United States)

    Garcia, Ana Maria.; Alexander, Richard B.; Arnold, Jeffrey G.; Norfleet, Lee; White, Michael J.; Robertson, Dale M.; Schwarz, Gregory E.

    2016-01-01

    Despite progress in the implementation of conservation practices, related improvements in water quality have been challenging to measure in larger river systems. In this paper we quantify these downstream effects by applying the empirical U.S. Geological Survey water-quality model SPARROW to investigate whether spatial differences in conservation intensity were statistically correlated with variations in nutrient loads. In contrast to other forms of water quality data analysis, the application of SPARROW controls for confounding factors such as hydrologic variability, multiple sources and environmental processes. A measure of conservation intensity was derived from the USDA-CEAP regional assessment of the Upper Mississippi River and used as an explanatory variable in a model of the Upper Midwest. The spatial pattern of conservation intensity was negatively correlated (p = 0.003) with the total nitrogen loads in streams in the basin. Total phosphorus loads were weakly negatively correlated with conservation (p = 0.25). Regional nitrogen reductions were estimated to range from 5 to 34% and phosphorus reductions from 1 to 10% in major river basins of the Upper Mississippi region. The statistical associations between conservation and nutrient loads are consistent with hydrological and biogeochemical processes such as denitrification. The results provide empirical evidence at the regional scale that conservation practices have had a larger statistically detectable effect on nitrogen than on phosphorus loadings in streams and rivers of the Upper Mississippi Basin.

  17. Regional Effects of Agricultural Conservation Practices on Nutrient Transport in the Upper Mississippi River Basin.

    Science.gov (United States)

    García, Ana María; Alexander, Richard B; Arnold, Jeffrey G; Norfleet, Lee; White, Michael J; Robertson, Dale M; Schwarz, Gregory

    2016-07-05

    Despite progress in the implementation of conservation practices, related improvements in water quality have been challenging to measure in larger river systems. In this paper we quantify these downstream effects by applying the empirical U.S. Geological Survey water-quality model SPARROW to investigate whether spatial differences in conservation intensity were statistically correlated with variations in nutrient loads. In contrast to other forms of water quality data analysis, the application of SPARROW controls for confounding factors such as hydrologic variability, multiple sources and environmental processes. A measure of conservation intensity was derived from the USDA-CEAP regional assessment of the Upper Mississippi River and used as an explanatory variable in a model of the Upper Midwest. The spatial pattern of conservation intensity was negatively correlated (p = 0.003) with the total nitrogen loads in streams in the basin. Total phosphorus loads were weakly negatively correlated with conservation (p = 0.25). Regional nitrogen reductions were estimated to range from 5 to 34% and phosphorus reductions from 1 to 10% in major river basins of the Upper Mississippi region. The statistical associations between conservation and nutrient loads are consistent with hydrological and biogeochemical processes such as denitrification. The results provide empirical evidence at the regional scale that conservation practices have had a larger statistically detectable effect on nitrogen than on phosphorus loadings in streams and rivers of the Upper Mississippi Basin.

  18. 76 FR 58533 - Powder River Regional Coal Team Activities; Notice of Public Meeting in Casper, WY

    Science.gov (United States)

    2011-09-21

    ... meeting is open to the public. ADDRESSES: The meeting will be held at the Wyoming Oil and Gas Conservation... Right Lease Applications in New Mexico held by Ark Land Company, for competitive bidding rights in... Powder River Coal Production Region. Any party interested in providing comments or data related to...

  19. About temporal evolution of the geomagnetic field in the River Plate region

    International Nuclear Information System (INIS)

    Gianibelli, J.; Quaglino, L.

    2010-01-01

    Permanent Observatories network allows to study the total intensity of the magnetic field of the Earth surface to assess its annual change and inductive effects on networks of large pipes and pipelines. This paper is about the results of the significant decline in the River Plate region. The effects observed in this surface anomaly continue amplified and reaching minimum values

  20. Potential of the Kakadu National Park Region

    Energy Technology Data Exchange (ETDEWEB)

    1988-01-01

    The Committee reviewed the potential of the Kakadu National Park region in the Northern Territory with particular reference to the nature of the resources available for exploitation and the impact of utilisation of these resources, particularly mining and tourism. Individual chapters discuss the Park, tourism, mineral resources (particularly the environmental and economic impacts of the Ranger Uranium Mine and the potential impacts of mining the Koongarra and Jabiluka deposits), the town of Jabiru, commercial fishing, other issues (the scientific resource, crocodiles, introduced species and fire), and park management and control (including a review of the role of the Office of the Supervising Scientist for the Alligator Rivers Region). A number of recommendations are made and the dissenting report of three of the Committee's members is included.

  1. Dissolved nitrogen in rivers: comparing pristine and impacted regions of Brazil

    Directory of Open Access Journals (Sweden)

    LA Martinelli

    Full Text Available Riverine nitrogen distribution is increasingly controlled by anthropogenic activities in their watersheds, regardless of spatial scale, climate, and geographical zone. Consequently, modelling efforts to predict the export of nitrogen from rivers worldwide have used attributes such as population density, land use, urbanization and sanitation. These models have greatly enhanced our understanding of the sources and fate of nitrogen added to terrestrial systems and transported to rivers and streams, especially for developed countries of the North temperate zone. However, much of the world's population lives in developing countries of the tropics, where the effects of human activities on riverine N exports are still poorly understood. In an effort to close this gap, we compare riverine nitrogen data from 32 Brazilian rivers draining two contrasting regions in this tropical country in terms of economic development - the State of São Paulo and the Amazon. Our data include nitrogen in different dissolved forms, such as Dissolved Inorganic Nitrogen (DIN and Dissolved Organic Nitrogen (DON. The results show that nitrogen concentrations decreased as river runoff increased in both study areas, and that concentrations were significantly higher in rivers draining the most economically developed region. The relationships between nitrogen concentrations and fluxes with demographic parameters such as population density were also determined and compared to those in temperate systems. In contrast to temperate watersheds, we found that nitrogen fluxes increased only after population densities were higher than 10 individuals per km².

  2. Chemical composition of black-watered rivers in the Amazons Region (Brazil)

    International Nuclear Information System (INIS)

    Horbe, Adriana M.C.; Santos, Ana G. da Silva

    2009-01-01

    Most investigations addressing Amazonian water chemistry are focused on the Solimoes, Amazonas and Negro rivers. Knowledge of the chemical composition of their smaller tributaries is restricted to some few, punctual data. The smaller rivers, that only present inputs from their catchments, are very important to understand the overall mechanisms controlling the chemistry of larger rivers of the region. With this objective the chemical composition of the principal Solimoes river black-watered tributaries in the western Brazilian Amazon during the low water period were determined. The data reveal the black water chemical composition to be highly variable and strongly influenced by the local geological environment: the Badajos basin being chemically more diluted; the Coari basin presenting higher SiO 2 contents, as well as smaller lakes having higher pH, conductivity, Ca 2+ , Mg 2+ and Sr, yet not as much as those found in the Solimoes river. The chemical composition of these waters is compatible with the low physical erosion and the region's highly leached tropical environment from which most soluble elements were quickly removed. (author)

  3. Ground-water resources in the tri-state region adjacent to the Lower Delaware River

    Science.gov (United States)

    Barksdale, Henry C.; Greenman, David W.; Lang, Solomon Max; Hilton, George Stockbridge; Outlaw, Donald E.

    1958-01-01

    The purpose of this report is to appraise and evaluate the groundwater resources of a tri-state region adjacent to the lower Delaware River that is centered around Philadelphia, Pa., and Camden, N. J., and includes Wilmington, Del., and Trenton, N.J. Specifically, the region includes New Castle County, Del.; Burlington, Camden, Gloucester, Mercer, and Salem Counties in New Jersey; and Bucks, Chester, Delaware, Montgomery, and Philadelphia Counties in Pennsylvania.

  4. Heavy metals in the small rivers of Ternopil region under different types of anthropogenic pressure

    Directory of Open Access Journals (Sweden)

    O. Prokopchuk

    2016-03-01

    Full Text Available The dynamic of content and peculiarities of migration of heavy metals in small rivers of Ternopil region were analyzed (Zn, Mn, Fe, Co, Ni, Pb. It was determined that cobalt does not exceed maximum permissible levels, whereas the content of other metals exceed these levels at rates from 2 to 42 times the emission limit set by the fishing industry. The waters of Ternopil region are the richest in the compounds of iron and manganese by virtue of the lithological content of the researched water basins. The excess in Mn and Fe concentration in river water is caused by occurrence of these elements in abiotic components of river valleys, particularly in areas with iron and manganese, alluvial deposits, clay soils with ferrous metal compounds and leaching of elements from rock, soil and forest litter. As our research showed, increased metal content in water basins is caused by natural factors (river running through areas with ore and where leaching of ore occurs it, reaction of interstitial water, metals appearing in ground water run-off, anthropogenic (waste waters of industrial plants, agricultural outwash, fuel combustion and hydrochemical factors of the hydroecosystem itself (consumption and releasing of metals by hydrobionts, aquatic habitat pH, metals coming in from ground sediments, metals released from complexes with organic compounds, methylation of non-organic metal compounds. A comparative analysis of the pollution levels of Ternopil region water basins by heavy metals was completed. It was determined that the river most heavily contaminated by the content of nutrients and non-biogenic HM is the Zolota Lypa and the cleanest is the River Strypa, which allows us to recommend the use of water composition as a reference indicator in assessing the ecological state of the region’s surface waters.

  5. Reemergence of rabies in the southern Han river region, Korea.

    Science.gov (United States)

    Oem, Jae-Ku; Kim, Seong-Hee; Kim, Yeon-Hee; Lee, Myoung-Heon; Lee, Kyoung-Ki

    2014-07-01

    Recently, 11 cases of animal rabies were reported in the southern region (Suwon and Hwaseong cities) of Gyeonggi Province, South Korea. The cases were temporally separated into two cases in dogs (Canis lupus familiaris) in spring 2012 and nine cases in domestic animals and wildlife in winter 2012-13. All carcasses were submitted for histopathologic examination and viral antigen identification. Sequences of the glycoprotein, nucleoprotein, and glycoprotein-large polymerase protein intergenic noncoding loci of the 11 strains were determined and compared with published reference sequences. All rabies strains were closely related to the Gangwon strains isolated in 2008-09, suggesting that the rabies virus strains isolated in Gyeonggi were introduced from Gangwon Province.

  6. Assessment of Water Quality of Subarnarekha River in Balasore Region, Odisha, India

    OpenAIRE

    A. A Karim; R. B Panda

    2014-01-01

    The present study was carried out to determine the water quality status of Subarnarekha River at Balasore region during pre-project period as Kirtania Port is proposed in this area. River water samples were analysed for physico-chemical parameters by following standard methods (APHA 1985) and the results showed their variations as follows: pH 7.3-7.8,Temperature 26.7-28.20C, Electrical Conductivity 392-514 µ mho ,Total suspended solids 118-148 mg/l, Total dissolved solids 241-285 mg/l, Alkali...

  7. Thermoregulation and temperature relations of alligators and other large ectotherms inhabiting thermally stressed habitats. Annual progress report, 1 July 1976--30 September 1977

    International Nuclear Information System (INIS)

    Spotila, J.R.

    1977-06-01

    Progress is reported on studies of the biophysical and thermal relationships between large ectotherms and their aquatic environment. Data are reported from laboratory and field studies on alligators, turtles, and fish. Mathematical models of the effect of body size and physical characteristics on temperature regulation of ectotherms and of thermal stress in aquatic organisms were developed. Results are included of field studies on the physiological and behavioral adjustments of turtles in response to changes in water temperature produced by thermal effluents in PAR Pond at the Savannah River Ecology Laboratory

  8. Columbia River System Operation Review final environmental impact statement. Appendix Q: Regional forum

    International Nuclear Information System (INIS)

    1995-11-01

    The System Operation Review (SOR) is a study and environmental compliance process being used by the three Federal agencies to analyze future operations of the system and river use issues. The goal of the SOR is to achieve a coordinated system operation strategy for the river that better meets the needs of all river users. This technical appendix addresses only the effects of alternative system operating strategies for managing the Columbia River system. The SOR is currently developing a System Operating Strategy (SOS) that will guide the physical operations of the Columbia River system. The SOR is also addressing the institutional arrangements that must be in place to make needed changes to the SOS in the future, or make interpretations of the strategy in the light of changing water conditions or river needs. For convenience, this future institutional arrangement is referred to as ''The Columbia River Regional Forum,'' or simply ''the Forum,'' even though the nature of this institution is still to be determined. This appendix and the Final Environmental Impact Statement (EIS) identify the Forum as an administrative process that will not result in impacts to the environment and will not require analysis in a NEPA context. The composition of and procedures followed by a decision making body cannot--in and of themselves--be used to predict a particular decision with definable impacts on the environment. Nevertheless, because of the relationship to the other SOR actions, the SOR lead agencies have prepared this Technical Appendix to provide opportunities for review and comment on the Forum alternatives

  9. Punctuated Sediment Discharge during Early Pliocene Birth of the Colorado River: Evidence from Regional Stratigraphy, Sedimentology, and Paleontology

    Science.gov (United States)

    Dorsey, Rebecca J.; O'Connell, Brennan; McDougall, Kristin; Homan, Mindy B.

    2018-01-01

    The Colorado River in the southwestern U.S. provides an excellent natural laboratory for studying the origins of a continent-scale river system, because deposits that formed prior to and during river initiation are well exposed in the lower river valley and nearby basinal sink. This paper presents a synthesis of regional stratigraphy, sedimentology, and micropaleontology from the southern Bouse Formation and similar-age deposits in the western Salton Trough, which we use to interpret processes that controlled the birth and early evolution of the Colorado River. The southern Bouse Formation is divided into three laterally persistent members: basal carbonate, siliciclastic, and upper bioclastic members. Basal carbonate accumulated in a tide-dominated marine embayment during a rise of relative sea level between 6.3 and 5.4 Ma, prior to arrival of the Colorado River. The transition to green claystone records initial rapid influx of river water and its distal clay wash load into the subtidal marine embayment at 5.4-5.3 Ma. This was followed by rapid southward progradation of the Colorado River delta, establishment of the earliest through-flowing river, and deposition of river-derived turbidites in the western Salton Trough (Wind Caves paleocanyon) between 5.3 and 5.1 Ma. Early delta progradation was followed by regional shut-down of river sand output between 5.1 and 4.8 Ma that resulted in deposition of marine clay in the Salton Trough, retreat of the delta, and re-flooding of the lower river valley by shallow marine water that deposited the Bouse upper bioclastic member. Resumption of sediment discharge at 4.8 Ma drove massive progradation of fluvial-deltaic deposits back down the river valley into the northern Gulf and Salton Trough. These results provide evidence for a discontinuous, start-stop-start history of sand output during initiation of the Colorado River that is not predicted by existing models for this system. The underlying controls on punctuated sediment

  10. Study of a conceptual nuclear energy center at Green River, Utah: regional considerations

    International Nuclear Information System (INIS)

    1982-01-01

    This document constitutes one segment of a feasibility study investigating the ramifications of constructing a nuclear energy center in an arid and remote Western region. This phase of the study discusses regional considerations involved in nuclear energy center development at Green River, Utah. Regional support for NEC development is assessed. In addition, possible regulatory constraints to NEC development are identified and analyzed. Possible resource allocation shortages resulting from NEC development are also considered. A comparison with a similar study on NEC development in the Southeastern United States is also included

  11. Comparison of metabolic substrates in alligators and several birds of prey.

    Science.gov (United States)

    Sweazea, Karen L; McMurtry, John P; Elsey, Ruth M; Redig, Patrick; Braun, Eldon J

    2014-08-01

    On average, avian blood glucose concentrations are 1.5-2 times those of mammals of similar mass and high concentrations of insulin are required to lower blood glucose. Whereas considerable data exist for granivorous species, few data are available for plasma metabolic substrate and glucoregulatory hormone concentrations for carnivorous birds and alligators. Birds and mammals with carnivorous diets have higher metabolic rates than animals consuming diets with less protein whereas alligators have low metabolic rates. Therefore, the present study was designed to compare substrate and glucoregulatory hormone concentrations in several birds of prey and a phylogenetically close relative of birds, the alligator. The hypothesis was that the combination of carnivorous diets and high metabolic rates favored the evolution of greater protein and fatty acid utilization leading to insulin resistance and high plasma glucose concentrations in carnivorous birds. In contrast, it was hypothesized that alligators would have low substrate utilization attributable to a low metabolic rate. Fasting plasma substrate and glucoregulatory hormone concentrations were compared for bald eagles (Haliaeetus leucocephalus), great horned owls (Bubo virginianus), red-tailed hawks (Buteo jamaicensis), and American alligators (Alligator mississippiensis). Avian species had high circulating β-hydroxybutyrate (10-21 mg/dl) compared to alligators (2.81 ± 0.16 mg/dl). In mammals high concentrations of this byproduct of fatty acid utilization are correlated with insulin resistance. Fasting glucose and insulin concentrations were positively correlated in eagles whereas no relationship was found between these variables for owls, hawks or alligators. Additionally, β-hydroxybutyrate concentrations were low in alligators. Similar to carnivorous mammals, ingestion of a high protein diet may have favored the utilization of fatty acids and protein for energy thereby promoting the development of insulin

  12. Identifying hotspots and management of critical ecosystem services in rapidly urbanizing Yangtze River Delta Region, China.

    Science.gov (United States)

    Cai, Wenbo; Gibbs, David; Zhang, Lang; Ferrier, Graham; Cai, Yongli

    2017-04-15

    Rapid urbanization has altered many ecosystems, causing a decline in many ecosystem services, generating serious ecological crisis. To cope with these challenges, we presented a comprehensive framework comprising five core steps for identifying and managing hotspots of critical ecosystem services in a rapid urbanizing region. This framework was applied in the case study of the Yangtze River Delta (YRD) Region. The study showed that there was large spatial heterogeneity in the hotspots of ecosystem services in the region, hotspots of supporting services and regulating services aggregately distributing in the southwest mountainous areas while hotspots of provisioning services mainly in the northeast plain, and hotspots of cultural services widespread in the waterbodies and southwest mountainous areas. The regionalization of the critical ecosystem services was made through the hotspot analysis. This study provided valuable information for environmental planning and management in a rapid urbanizing region and helped improve China's ecological redlines policy at regional scale. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Run-of-river power plants in Alpine regions: whither optimal capacity?

    Science.gov (United States)

    Lazzaro, Gianluca; Botter, Gianluca

    2015-04-01

    Hydropower is the major renewable electricity generation technology worldwide. The future expansion of this technology mostly relies on the development of small run-of-river projects, in which a fraction of the running flows is diverted from the river to a turbine for energy production. Even though small hydro inflicts a smaller impact on aquatic ecosystems and local communities compared to large dams, it cannot prevent stresses on plant, animal, and human well-being. This is especially true in mountain regions where the plant outflow is located several kilometers downstream of the intake, thereby inducing the depletion of river reaches of considerable length. Moreover, the negative cumulative effects of run-of-river systems operating along the same river threaten the ability of stream networks to supply ecological corridors for plants, invertebrates or fishes, and support biodiversity. Research in this area is severely lacking. Therefore, the prediction of the long-term impacts associated to the expansion of run-of-river projects induced by global-scale incentive policies remains highly uncertain. This contribution aims at providing objective tools to address the preliminary choice of the capacity of a run-of-river hydropower plant when the economic value of the plant and the alteration of the flow regime are simultaneously accounted for. This is done using the concepts of Pareto-optimality and Pareto-dominance, which are powerful tools suited to face multi-objective optimization in presence of conflicting goals, such as the maximization of the profitability and the minimization of the hydrologic disturbance induced by the plant in the river reach between the intake and the outflow. The application to a set of case studies belonging to the Piave River basin (Italy) suggests that optimal solutions are strongly dependent the natural flow regime at the plant intake. While in some cases (namely, reduced streamflow variability) the optimal trade-off between economic

  14. Regional implications of heat flow of the Snake River Plain, Northwestern United States

    Science.gov (United States)

    Blackwell, D. D.

    1989-08-01

    The Snake River Plain is a major topographic feature of the Northwestern United States. It marks the track of an upper mantle and crustal melting event that propagated across the area from southwest to northeast at a velocity of about 3.5 cm/yr. The melting event has the same energetics as a large oceanic hotspot or plume and so the area is the continental analog of an oceanic hotspot track such as the Hawaiian Island-Emperor Seamount chain. Thus, the unique features of the area reflect the response of a continental lithosphere to a very energetic hotspot. The crust is extensively modified by basalt magma emplacement into the crust and by the resulting massive rhyolite volcanism from melted crustal material, presently occurring at Yellowstone National Park. The volcanism is associated with little crustal extension. Heat flow values are high along the margins of the Eastern and Western Snake River Plains and there is abundant evidence for low-grade geothermal resources associated with regional groundwater systems. The regional heat flow pattern in the Western Snake River Plains reflects the influence of crustal-scale thermal refraction associated with the large sedimentary basin that has formed there. Heat flow values in shallow holes in the Eastern Snake River Plains are low due to the Snake River Plains aquifer, an extensive basalt aquifer where water flow rates approach 1 km/yr. Below the aquifer, conductive heat flow values are about 100 mW m -2. Deep holes in the region suggest a systematic eastward increase in heat flow in the Snake River Plains from about 75-90 mW m -2 to 90-110 mW m -2. Temperatures in the upper crust do not behave similarly because the thermal conductivity of the Plio-Pleistocene sedimentary rocks in the west is lower than that in the volcanic rocks characteristic of the Eastern Snake River Plains. Extremely high heat loss values (averaging 2500 mW m -2) and upper crustal temperatures are characteristic of the Yellowstone caldera.

  15. Regional transport of radioxenon released from the Chalk River Laboratories medical isotope facility

    International Nuclear Information System (INIS)

    Christine Johnson; Steven Biegalski

    2015-01-01

    An examination of proposed sampling sites near Chalk River Laboratories in Ontario, Canada is performed by considering the regional transport of radioxenon using atmospheric dispersion modeling. The local geography is considered, as are the local meteorological conditions during the summer months. In particular the impacts of predicted conditions on the imprinting of atmospheric radioxenon into the subsurface are considered and weighed against site proximity, geography, and geology. (author)

  16. ALTERED HISTOLOGY OF THE THYMUS AND SPLEEN IN CONTAMINANT-EXPOSED JUVENILE AMERICAN ALLIGATORS

    Science.gov (United States)

    Morphological difference in spleen and thymus are closely related to functional immune differences. Hormonal regulation of the immune system has been demonstrated in reptilian splenic and thymic tissue. Spleens and thymus were obtained from juvenile alligators at two reference si...

  17. Management of regional German river catchments (REGFLUD) impact of nitrogen reduction measures on the nitrogen load in the River Ems and the River Rhine.

    Science.gov (United States)

    Kunkel, R; Bogena, H; Goemann, H; Kreins, P; Wendland, F

    2005-01-01

    The REGFLUD-project, commissioned by Germany's Federal Research Ministry (BMBF), addresses the problem of reducing diffuse pollution from agricultural production. The objective of the project is the development and application of multi-criteria scientific methods, which are able to predict diffuse pollution in river basins subject to economic feasibility and social acceptability. The selected river basins (Ems and Rhine basins) cover a variety of landscape units with different hydrological, hydrogeological and socio-economic characteristics. This paper focuses on the analysis of the effects of certain policy measures to reduce diffuse pollution by nitrogen. For this purpose a model system consisting of an agricultural sector model, a water balance model and a residence time/denitrification model was developed and applied. First results indicate a wide range of annual nitrogen surpluses for the rural areas between less than 10 kg N/ha up to 200 kg N/ha or more depending on the type and intensity of farming. Compared to the level of nitrogen surpluses the level of nitrogen inputs into the surface waters is relatively moderate because of degradation processes during transport in soil and groundwater. Policy impact analysis for a nitrogen tax and a limitation of the livestock density stress the importance of regionally tailored measures.

  18. Application of HEC-RAS for flood forecasting in perched river-A case study of hilly region, China

    Science.gov (United States)

    Sun, Pingping; Wang, Shuqian; Gan, Hong; Liu, Bin; Jia, Ling

    2017-04-01

    Flooding in small and medium rivers are seriously threatening the safety of human beings’ life and property. The simulation forecasting of the river flood and bank risk in hilly region has gradually become a hotspot. At present, there are few studies on the simulation of hilly perched river, especially in the case of lacking section flow data. And the method of how to determine the position of the levee breach along the river bank is not much enough. Based on the characteristics of the sections in hilly perched river, an attempt is applied in this paper which establishes the correlation between the flow profile computed by HEC-RAS model and the river bank. A hilly perched river in Lingshi County, Shanxi Province of China, is taken as the study object, the levee breach positions along the bank are simulated under four different design storm. The results show that the flood control standard of upper reach is high, which can withstand the design storm of 100 years. The current standard of lower reach is low, which is the flooding channel with high frequency. As the standard of current channel between the 2rd and the 11th section is low, levee along that channel of the river bank is considered to be heighten and reinforced. The study results can provide some technical support for flood proofing in hilly region and some reference for the reinforcement of river bank.

  19. International Trade, Pollution Accumulation and Sustainable Growth: A VAR Estimation from the Pearl River Delta Region

    Science.gov (United States)

    Zuo, Hui; Tian, Lu

    2018-03-01

    In order to investigate international trade influence in the regional environment. This paper constructs a vector auto-regression (VAR) model and estimates the equations with the environment and trade data of the Pearl River Delta Region. The major mechanisms to the lag are discussed and the fit simulation of the environmental change by the international impulse is given. The result shows that impulse of pollution-intensive export deteriorates the environment continuously and impulse of such import improves it. These effects on the environment are insignificantly correlated with contemporary regional income but significantly correlative to early-stage trade feature. To a typical trade-dependent economy, both export and import have hysteresis influence in the regional environment. The lagged impulse will change environmental development in the turning point, maximal pollution level and convergence.

  20. Mercury and arsenic in the gold mining regions of the Ankobra River basin in Ghana

    Science.gov (United States)

    Bannerman, W.; Potin-Gautier, M.; Amoureux, D.; Tellier, S.; Rambaud, A.; Babut, M.; Adimado, A.; Beinhoff, C.

    2003-05-01

    The river Ankobra flows through the principal gold mining centres in Western Ghana, draining a total area of 8272 km^2 to join the Atlantic ocean. Mercury is used by thousands of small-scale miners in the region to amalgamate gold. Ores mined in some deep shafts and surface mines are arsenopyrites and the region is marked by the presence of heaps of arsenic - rich mine tailings from both past and recent activities. This study was conducted to assess the impact of mining activities on the distribution and speciation of arsenic and mercury in the aquatic environment of the Ankobra River. In all, water (filtered and non-filtered) and bed sediments were collected from various locations within the watershed. Principal parameters investigated include total mercury, arsenic (III), arsenic (V), monomethylarsonic acid (MMAA) and dimethylarsinic acid (DMAA). Seasonal and spatial variations of these parameters were investigated. Quality control systems were adopted at both the environmental and analytical stages of the study. ln general, areas close to the mining centres are the most pollilited. As (V)/As (III) ratios in water are reversed after the first 100-km of the river length with the onset of industrial influence downstream.

  1. The potential of the Kakadu National Park Region

    International Nuclear Information System (INIS)

    1988-11-01

    The Committee reviewed the potential of the Kakadu National Park region in the Northern Territory with particular reference to the nature of the resources available for exploitation and the impact of utilisation of these resources, particularly mining and tourism. Individual chapters discuss the Park, tourism, mineral resources (particularly the environmental and economic impacts of the Ranger Uranium Mine and the potential impacts of mining the Koongarra and Jabiluka deposits), the town of Jabiru, commercial fishing, other issues (the scientific resource, crocodiles, introduced species and fire), and park management and control (including a review of the role of the Office of the Supervising Scientist for the Alligator Rivers Region). A number of recommendations are made and the dissenting report of three of the Committee's members is included

  2. Population structure and genetic diversity of Sinibrama macrops from Ou River and Ling River based on mtDNA D-loop region analysis, China.

    Science.gov (United States)

    Zhao, Liangjie; Chenoweth, Erica L; Liu, Qigen

    2018-03-01

    In order to understand the influence of human activities such as habitat fragmentation on freshwater fish population evolution, we investigated and compared the genetic diversity and phylogeography of Sinibrama macrops populations in the Oujiang River and Ling River. Mitochondrial control region sequences (D-loop region) of 131 specimens from six populations were obtained and analyzed. The diversity of main stream in the Ou River was lower than that in Ling River. Changtan population showed the lowest diversity (H = 0.646 ± 0.077; π = 0.00060 ± 0.00820). Pairwise F ST , gene flow (Nm), and genetic distance (Da) indicated that Longquan and Changtan significantly differentiate from other populations. Nested clade phylogeographical analysis (NCPA) showed some clades and total cladogram experienced isolation by distance. In conclusion, the populations from severely fragmented Ou River have the lower diversity and more intense differentiation than that from the mainstream of Ling River, Changtan population present the lowest diversity and were isolated by the dam construction.

  3. Punctuated sediment discharge during early Pliocene birth of the Colorado River: Evidence from regional stratigraphy, sedimentology, and paleontology

    Science.gov (United States)

    Dorsey, Rebecca J.; O’Connell, Brennan; McDougall-Reid, Kristin; Homan, Mindy B.

    2018-01-01

    The Colorado River in the southwestern U.S. provides an excellent natural laboratory for studying the origins of a continent-scale river system, because deposits that formed prior to and during river initiation are well exposed in the lower river valley and nearby basinal sink. This paper presents a synthesis of regional stratigraphy, sedimentology, and micropaleontology from the southern Bouse Formation and similar-age deposits in the western Salton Trough, which we use to interpret processes that controlled the birth and early evolution of the Colorado River. The southern Bouse Formation is divided into three laterally persistent members: basal carbonate, siliciclastic, and upper bioclastic members. Basal carbonate accumulated in a tide-dominated marine embayment during a rise of relative sea level between ~ 6.3 and 5.4 Ma, prior to arrival of the Colorado River. The transition to green claystone records initial rapid influx of river water and its distal clay wash load into the subtidal marine embayment at ~ 5.4–5.3 Ma. This was followed by rapid southward progradation of the Colorado River delta, establishment of the earliest through-flowing river, and deposition of river-derived turbidites in the western Salton Trough (Wind Caves paleocanyon) between ~ 5.3 and 5.1 Ma. Early delta progradation was followed by regional shut-down of river sand output between ~ 5.1 and 4.8 Ma that resulted in deposition of marine clay in the Salton Trough, retreat of the delta, and re-flooding of the lower river valley by shallow marine water that deposited the Bouse upper bioclastic member. Resumption of sediment discharge at ~ 4.8 Ma drove massive progradation of fluvial-deltaic deposits back down the river valley into the northern Gulf and Salton Trough.These results provide evidence for a discontinuous, start-stop-start history of sand output during initiation of the Colorado River that is not predicted by existing models for this system. The underlying controls on

  4. Use of alligator hole abundance and occupancy rate as indicators for restoration of a human-altered wetland

    Science.gov (United States)

    Fujisaki, Ikuko; Mazzotti, Frank J.; Hart, Kristen M.; Rice, Kenneth G.; Ogurcak, Danielle; Rochford, Michael; Jeffery, Brian M.; Brandt, Laura A.; Cherkiss, Michael S.

    2012-01-01

    Use of indicator species as a measure of ecosystem conditions is an established science application in environmental management. Because of its role in shaping wetland systems, the American alligator (Alligator mississippiensis) is one of the ecological indicators for wetland restoration in south Florida, USA. We conducted landscape-level aerial surveys of alligator holes in two different habitats in a wetland where anthropogenic modification of surface hydrology has altered the natural system. Alligator holes were scarcer in an area where modified hydrology caused draining and frequent dry-downs compared to another area that maintains a functional wetland system. Lower abundance of alligator holes indicates lack of alligator activities, lower overall species diversity, and lack of dry-season aquatic refugia for other organisms. The occupancy rate of alligator holes was lower than the current restoration target for the Everglades, and was variable by size class with large size-class alligators predominantly occupying alligator holes. This may indicate unequal size-class distribution, different habitat selection by size classes, or possibly a lack of recruitment. Our study provides pre-restoration baseline information about one indicator species for the Everglades. Success of the restoration can be assessed via effective synthesis of information derived by collective research efforts on the entire suite of selected ecological indicators.

  5. Remediating the South Alligator Valley uranium mining legacy

    International Nuclear Information System (INIS)

    Fawcett, M.; Waggitt, P.

    2010-01-01

    In late 1950s and early 1960s 13 uranium mines operated in the South Alligator Valley of Australia's Northern Territory. Once sales contracts had been filled the mines were abandoned and no remediation took place. In the 1980s the valley was designated as part of Stage 3 of the adjacent World Heritage-listed, Kakadu National Park. Proposals for remediation were only seriously put forward when the land was returned to the traditional Aboriginal owners, the Gunlom Land Trust, in 1996. Although they leased the land back so it would remain a part of Kakadu National Park the traditional Aboriginal owners required remediation to be complete by 2015. This paper tells the story of the development and implementation of the remediation process from the start of planning in 1998 to completion in 2009; and finally it describes the development of stakeholder relationships and the initial plans for long term stewardship. (author)

  6. A Study on Regional Frequency Analysis using Artificial Neural Network - the Sumjin River Basin

    Science.gov (United States)

    Jeong, C.; Ahn, J.; Ahn, H.; Heo, J. H.

    2017-12-01

    Regional frequency analysis means to make up for shortcomings in the at-site frequency analysis which is about a lack of sample size through the regional concept. Regional rainfall quantile depends on the identification of hydrologically homogeneous regions, hence the regional classification based on hydrological homogeneous assumption is very important. For regional clustering about rainfall, multidimensional variables and factors related geographical features and meteorological figure are considered such as mean annual precipitation, number of days with precipitation in a year and average maximum daily precipitation in a month. Self-Organizing Feature Map method which is one of the artificial neural network algorithm in the unsupervised learning techniques solves N-dimensional and nonlinear problems and be shown results simply as a data visualization technique. In this study, for the Sumjin river basin in South Korea, cluster analysis was performed based on SOM method using high-dimensional geographical features and meteorological factor as input data. then, for the results, in order to evaluate the homogeneity of regions, the L-moment based discordancy and heterogeneity measures were used. Rainfall quantiles were estimated as the index flood method which is one of regional rainfall frequency analysis. Clustering analysis using SOM method and the consequential variation in rainfall quantile were analyzed. This research was supported by a grant(2017-MPSS31-001) from Supporting Technology Development Program for Disaster Management funded by Ministry of Public Safety and Security(MPSS) of the Korean government.

  7. Biochemical composition of the alligator pipefish, Syngnathoides biaculeatus (Bloch, 1785)

    Science.gov (United States)

    Sanaye, Sushant Vilas; Pawar, Ashwini Pandurang; Rivonker, Chandrasheker Umanath; Sreepada, Rayadurga Anantha; Ansari, Zakir Ali; Ram, Anirudh

    2017-11-01

    Considering the economic importance in traditional Chinese medicine (TCM) and lack of baseline information, we evaluated the proximate composition, fatty acid and amino acid profiles, trace element content and C:N ratio in the alligator pipefish, Syngnathoides biaculeatus. Amongst proximate principals, a crude protein formed the major biochemical component ((58.9±2.2)% dry weight). Mean percent concentrations (dry weight) of other components such as a total lipid (TL), ash and nitrogen-free extract measured were, (1.8±0.2)%, (19.2±2.2)% and (20.1±0.45)%, respectively. The fatty acid profile revealed the presence of 27 saturated fatty acids (SFA) with 13 straight-chained and 14 branched-chained, 28 unsaturated fatty acids (UFA) with 14 monounsaturated and 14 polyunsaturated and nine other minor fatty acids. Mean percent contributions of total SFAs and UFAs to TL were found to be (55.41±0.24)% and (44.05±0.25)%, respectively. Altogether, 16 different amino acids with an equal number of essential (EAA) and non-essential (NAA) ones were identified. Percent contributions by EAA and NAA to the total amino acid content were 38.11% and 61.89%, respectively. Trace metal concentrations in S. biaculeatus were generally low and their distribution followed the order, Mg>Fe>Zn>Mn>Cu>Cr>Ni>Hg>Co. The C:N ratio was (4.37±0.04)%. The profile of major biochemical constituents in alligator pipefish, S. biaculeatus revealed its potential use in TCM as well as a nutritional diet for human consumption. The results of the study would also form the basis for formulation and optimization of diets for the culture of S. biaculeatus.

  8. Nitrate induces a type 1 diabetic profile in alligator hatchlings.

    Science.gov (United States)

    Edwards, Thea M; Hamlin, Heather J; Freymiller, Haley; Green, Stephen; Thurman, Jenna; Guillette, Louis J

    2018-01-01

    Type 1 diabetes (T1D) is a chronic autoimmune disease that affects 1 in 300 children by age 18. T1D is caused by inflammation-induced loss of insulin-producing pancreatic beta cells, leading to high blood glucose and a host of downstream complications. Although multiple genes are associated with T1D risk, only 5% of genetically susceptible individuals actually develop clinical disease. Moreover, a growing number of T1D cases occur in geographic clusters and among children with low risk genotypes. These observations suggest that environmental factors contribute to T1D etiology. One potential factor, supported primarily by epidemiological studies, is the presence of nitrate and nitrite in drinking water. To test this hypothesis, female hatchling alligators were exposed to environmentally relevant concentrations of nitrate in their tank water (reference, 10mg/L, or 100mg/L NO 3 -N) from hatch through 5 weeks or 5 months of age. At each time point, endpoints related to T1D were investigated: plasma levels of glucose, triglycerides, testosterone, estradiol, and thyroxine; pancreas, fat body, and thyroid weights; weight gain or loss; presence of immune cells in the pancreas; and pancreatic beta cell number, assessed by antibody staining of nkx6.1 protein. Internal dosing of nitrate was confirmed by measuring plasma and urine nitrate levels and whole blood methemoglobin. Cluster analysis indicated that high nitrate exposure (most animals exposed to 100mg/L NO3-N and one alligator exposed to 10mg/L NO3-N) induced a profile of endpoints consistent with early T1D that could be detected after 5 weeks and was more strongly present after 5 months. Our study supports epidemiological data correlating elevated nitrate with T1D onset in humans, and highlights nitrate as a possible environmental contributor to the etiology of T1D, possibly through its role as a nitric oxide precursor. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Impact of emission control on regional air quality in the Pearl Delta River region, southern China

    Science.gov (United States)

    Wang, N.; Xuejiao, D.

    2017-12-01

    The Pearl River Delta (PRD) in China has been suffering from air quality issues and the government has implemented a series of strategies in controlling emissions. In an attempt to provide scientific support for improving air quality, the paper investigates the concerning past-to-present air quality data and assesses air quality resulting from emission control. Statistical data revealed that energy consumption doubled from 2004 to 20014 and vehicle usage increased significantly from 2006 to 2014. Due to the effect of control efforts, primary emission of SO2, NOx and PM2.5 decreased resulting in ambient concentrations of SO2, NO2 and PM10 decreased by 66%, 20% and 24%, respectively. However, O3 increased 19% because of the increase of VOC emission. A chemical transport model, the Community Multi-scale Air Quality, was employed to evaluate the responses of nitrate, ammonium, SOA, PM2.5 and O3 to changes in NOx, VOC and NH3 emissions. Three scenarios, a baseline scenario, a CAP scenario (control strength followed as past tendency), and a REF scenario (strict control referred to latest policy and plans), were conducted to investigate the responses and mechanisms. NOx controlling scenarios showed that NOx, nitrate and PM2.5 reduced by 1.8%, 0.7% and 0.2% under CAP and reduced by 7.2%, 1.8% and 0.3% under REF, respectively. The results indicated that reducing NOx emission caused the increase of atmospheric oxidizability, which might result in a compensation of PM2.5 due to the increase of nitrate or sulfate. NH3 controlling scenarios showed that nitrate was sensitive to NH3 emission in PRD, with nitrate decreased by 0 - 10.6% and 0 - 48% under CAP and REF, respectively. Since controlling NH3 emissions not only reduced ammonium but also significantly reduced nitrate, the implement of NH3 controlling strategy was highly suggested. The VOC scenarios revealed that though SOA was not the major component of PM2.5, controlling VOC emission might take effect in southwestern PRD

  10. Urbanization signatures in strong versus weak precipitation over the Pearl River Delta metropolitan regions of China

    International Nuclear Information System (INIS)

    Li Weibiao; Chen Sheng; Wen Zhiping; Wang Baomin; Chen Guixing; Sha Weimin; Luo Cong; Feng Yerong

    2011-01-01

    We assess the issues of urban effects on the precipitation over the Pearl River Delta (PRD) metropolitan regions of China. The spatial and temporal variations of strong versus weak precipitation over the PRD and surrounding nonurban areas are investigated. The results show that the urbanization signatures in strong precipitation are significantly different from those in weak precipitation over the urban areas. The PRD experiences more strong precipitation but less weak precipitation compared to surrounding nonurban regions. In addition, the strong precipitation over the PRD displays a pronounced seasonal variation. The seasonality of weak precipitation, however, is much weaker over the PRD compared to the surrounding nonurban regions. Moreover, a strengthening in the precipitation intensity, a reduction in the rainfall frequency and an increase in the convective precipitation as well as the afternoon precipitation are found over the urban areas, which are probably associated with the abundance in strong precipitation and the deficit in weak precipitation over the PRD.

  11. Recognition of key regions for restoration of phytoplankton communities in the Huai River basin, China

    Science.gov (United States)

    Zhao, Changsen; Liu, Changming; Xia, Jun; Zhang, Yongyong; Yu, Qiang; Eamus, Derek

    2012-02-01

    SummaryHealthy phytoplankton communities are the basis of healthy water ecosystems, and form the foundation of many freshwater food webs. Globally many freshwater ecosystems are degraded because of intensive human activities, so water ecosystem restoration is a burning issue worldwide. Selection of key regions for phytoplankton-related restoration is crucial for an effective aquatic eco-restoration. This paper presents a practical method for identification of key regions for phytoplankton-related restoration, using random forests (RFs) method to cluster sites based on dominance, biodiversity, water chemistry and ecological niche. We sampled phytoplankton for species richness and relative abundance and water quality in the Huai River basin (HRB), China to determine the phytoplankton communities' composition and structure and characterize of their ecological niches. A wider mean niche breadth of a species usually leads to a greater overlap with the niche of other species. Using these data and water quality indices, we identified the key regions for phytoplankton-related river restoration activities. Results indicate that our method for recognition of key regions is effective and practical and its application to the HRB identified the Northern Plain area as the key region for restoration. This area is severely polluted and contributes significantly to the HRB phytoplankton communities. Phytoplankton in this region is highly adaptable to environmental change and therefore will be relatively unharmed by environmental instability induced by restoration measures. During restoration, indices of water temperature, total phosphorus and chemical oxygen demand can be altered with little negative influence on phytoplankton communities, but measures that increase ammonia-nitrogen concentration would be highly detrimental. These results will provide valuable information for policy makers and stakeholders in water ecosystem restoration and sustainable basin management in the HRB.

  12. Regional contribution to PM1 pollution during winter haze in Yangtze River Delta, China.

    Science.gov (United States)

    Tang, Lili; Yu, Hongxia; Ding, Aijun; Zhang, Yunjiang; Qin, Wei; Wang, Zhuang; Chen, Wentai; Hua, Yan; Yang, Xiaoxiao

    2016-01-15

    To quantify regional sources contributing to submicron particulate matter (PM1) pollution in haze episodes, on-line measurements combining two modeling methods, namely, positive matrix factorization (PMF) and backward Lagrangian particle dispersion modeling (LPDM), were conducted for the period of one month in urban Nanjing, a city located in the western part of Yangtze River Delta (YRD) region of China. Several multi-day haze episodes were observed in December 2013. Long-range transport of biomass burning from the southwestern YRD region largely contributed to PM1 pollution with more than 25% of total organics mass in a lasting heavy haze. The LPDM analysis indicates that regional transport is a main source contributing to secondary low-volatility production. The high-potential source regions of secondary low-volatility production are mainly located in areas to the northeast of the city. High aerosol pollution was mainly contributed by regional transport associated with northeastern air masses. Such regional transport on average accounts for 46% of total NR-PM1 with sulfate and aged low-volatility organics being the largest fractions (>65%). Copyright © 2015 Elsevier B.V. All rights reserved.

  13. CLASSIFICATION OF BENTHIC BIOCENOSES OF THE LOWLAND RIVER TUDOVKA (TVER REGION, RUSSIA USING COMMUNITY FEATURES

    Directory of Open Access Journals (Sweden)

    M. Schletterer

    2017-01-01

    Full Text Available Within the joint Russian-Austrian monitoring programme “REFCOND_VOLGA (2006 – 20XX”, monitoring sites were established in the headwaters of the Volga (Tver Region. River Tudovka, a right tributary to the Volga River, was included within this monitoring programme as its catchment is partly protected and has only few anthropogenic activities. The monitoring activities include physico-chemical and hydraulic parameters as well as biota with a focus is on benthic organisms (diatoms and macrozoobenthos. In this work, the longitudinal patterns in community structure are classified in the lowland river Tudovka using a novel feature-based approach taken from signal processing theory. The method first clusters field sampling data into longitudinal classes (upper, middle, lower course. Community features based on the relative frequency of individual species occurring per class are then generated. We apply both generative and discriminative classification methods. The application of generative methods provides data models which predict the probability of a new sample to belong to an existing class. In contrast, discriminative approaches search for differences between classes and allocate new data accordingly. Leveraging both methods allows for the creation of stable classifications. On this basis we show how the community features can be used to predict the longitudinal class. The community features approach also allows for a robust cross-comparison of investigation reaches over time. In cases where suitable long-term data set are available, predictive models using this approach can also be developed.

  14. Regional precipitation trend analysis at the Langat River Basin, Selangor, Malaysia

    Science.gov (United States)

    Palizdan, Narges; Falamarzi, Yashar; Huang, Yuk Feng; Lee, Teang Shui; Ghazali, Abdul Halim

    2014-08-01

    Various hydrological and meteorological variables such as rainfall and temperature have been affected by global climate change. Any change in the pattern of precipitation can have a significant impact on the availability of water resources, agriculture, and the ecosystem. Therefore, knowledge on rainfall trend is an important aspect of water resources management. In this study, the regional annual and seasonal precipitation trends at the Langat River Basin, Malaysia, for the period of 1982-2011 were examined at the 95 % level of significance using the regional average Mann-Kendall (RAMK) test and the regional average Mann-Kendall coupled with bootstrap (RAMK-bootstrap) method. In order to identify the homogeneous regions respectively for the annual and seasonal scales, firstly, at-site mean total annual and separately at-site mean total seasonal precipitation were spatialized into 5 km × 5 km grids using the inverse distance weighting (IDW) algorithm. Next, the optimum number of homogeneous regions (clusters) is computed using the silhouette coefficient approach. Next, the homogeneous regions were formed using the K-mean clustering method. From the annual scale perspective, all three regions showed positive trends. However, the application of two methods at this scale showed a significant trend only in the region AC1. The region AC2 experienced a significant positive trend using only the RAMK test. On a seasonal scale, all regions showed insignificant trends, except the regions I1C1 and I1C2 in the Inter-Monsoon 1 (INT1) season which experienced significant upward trends. In addition, it was proven that the significance of trends has been affected by the existence of serial and spatial correlations.

  15. Paleocene origin of the cockroach families Blaberidae and Corydiidae: Evidence from Amur River region of Russia.

    Science.gov (United States)

    Vršanský, Peter; Vidlička, L'Ubomír; Barna, Peter; Bugdaeva, Eugenia; Markevich, Valentina

    2013-01-01

    Morphna paleo sp. n., the earliest winged representative of any living cockroach genus and the earliest representative of the family Blaberidae, is described from the Danian Arkhara-Boguchan coal mine in the Amur River region (Russian Far East). The branched Sc and A suggest Ectobiidae (=Blattellidae) probably is not the ancestral family because Blaberidae were derived directly from the extinct family Mesoblattindae. The associated Danian locality Belaya Gora yielded Ergaula stonebut sp. n., the earliest record of the family Corydiidae. Both species belong to genera codominant in the Messel locality, thus validating their dominance in early Cenozoic assemblages.

  16. A regional neural network model for predicting mean daily river water temperature

    Science.gov (United States)

    Wagner, Tyler; DeWeber, Jefferson Tyrell

    2014-01-01

    Water temperature is a fundamental property of river habitat and often a key aspect of river resource management, but measurements to characterize thermal regimes are not available for most streams and rivers. As such, we developed an artificial neural network (ANN) ensemble model to predict mean daily water temperature in 197,402 individual stream reaches during the warm season (May–October) throughout the native range of brook trout Salvelinus fontinalis in the eastern U.S. We compared four models with different groups of predictors to determine how well water temperature could be predicted by climatic, landform, and land cover attributes, and used the median prediction from an ensemble of 100 ANNs as our final prediction for each model. The final model included air temperature, landform attributes and forested land cover and predicted mean daily water temperatures with moderate accuracy as determined by root mean squared error (RMSE) at 886 training sites with data from 1980 to 2009 (RMSE = 1.91 °C). Based on validation at 96 sites (RMSE = 1.82) and separately for data from 2010 (RMSE = 1.93), a year with relatively warmer conditions, the model was able to generalize to new stream reaches and years. The most important predictors were mean daily air temperature, prior 7 day mean air temperature, and network catchment area according to sensitivity analyses. Forest land cover at both riparian and catchment extents had relatively weak but clear negative effects. Predicted daily water temperature averaged for the month of July matched expected spatial trends with cooler temperatures in headwaters and at higher elevations and latitudes. Our ANN ensemble is unique in predicting daily temperatures throughout a large region, while other regional efforts have predicted at relatively coarse time steps. The model may prove a useful tool for predicting water temperatures in sampled and unsampled rivers under current conditions and future projections of climate

  17. MACROZOOBENTHOS OF MOUNTAIN RIVERS OF THE TRANSCARPATHIAN REGION AS A FORAGE BASE OF BENTHOPHAGOUS FISHES AND SAPROBITY INDICATOR

    Directory of Open Access Journals (Sweden)

    S. Kruzhylina

    2014-12-01

    Full Text Available Purpose. To study qualitative and qualitative indices of macrozoobenthos as one of main components of the forage base of benthophagous fishes in mountain river reaches of the Transcarpathian region and determination of their saprobity level. Methodology. Thhj,9.e study was carried out in summer period of 2009 in mountain river reaches of the Tisa river catchment. Zoobenthos samples were collected by a Surber sampler (25 × 25 cm on the bottoms of different fractions with different water flow rate (riffle, run, pool. Collection, processing and interpretation of the obtained data was carried out according to generally accepted hydrobiological methods developed for mountain river studies. Saprobity was of the studied rivers was calculated by Pantle-Buck formula. The Zelinka-Marvan saprobity index was used for calculations. Findings. Qualitative and quantitative macrozoobenthos indices have been studied. The number of zoobenthos on the investigated river sections ranged from 416 to 7712 ind./m2 with biomasses from 2.96 to 83.84 g/m2. The major portion of the zoobenthic biomass in the majority of rivers was due to caddis fly larvae composing up to 93% of the total biomass. An important role in the total biomass of the zoobenthos also belonged to mayfly (up to 53% and stonefly (up to 55% larvae and in lower degree amphipods (up to 39%, chironomid larvae (up to 14% and aquatic coleopterans (up to 5%. According to the calculated potential fish productivity, the mountain rivers can be apparently separated into three groups: little productive (4.2–12.7 kg/ha, medium productive (13.2–21.6 kg/ha and high productive (25.3–85.3 kg/ha. Mountain river reaches of the Transcarpathian region were found to belong to pure χ-saprobic, and о- і β-mesosaprobic zones, the saprobity index in which ranged from 0.35 (Rika river to 1.7 (Shipot river. Originality. For further calculation and assessment of brown trout (Salmo trutta and European grayling (Thymallus

  18. Groundwater recharge, circulation and geochemical evolution in the source region of the Blue Nile River, Ethiopia

    International Nuclear Information System (INIS)

    Kebede, Seifu; Travi, Yves; Alemayehu, Tamiru; Ayenew, Tenalem

    2005-01-01

    Geochemical and environmental isotope data were used to gain the first regional picture of groundwater recharge, circulation and its hydrochemical evolution in the upper Blue Nile River basin of Ethiopia. Q-mode statistical cluster analysis (HCA) was used to classify water into objective groups and to conduct inverse geochemical modeling among the groups. Two major structurally deformed regions with distinct groundwater circulation and evolution history were identified. These are the Lake Tana Graben (LTG) and the Yerer Tullu Wellel Volcanic Lineament Zone (YTVL). Silicate hydrolysis accompanied by CO 2 influx from deeper sources plays a major role in groundwater chemical evolution of the high TDS Na-HCO 3 type thermal groundwaters of these two regions. In the basaltic plateau outside these two zones, groundwater recharge takes place rapidly through fractured basalts, groundwater flow paths are short and they are characterized by low TDS and are Ca-Mg-HCO 3 type waters. Despite the high altitude (mean altitude ∼2500 masl) and the relatively low mean annual air temperature (18 deg. C) of the region compared to Sahelian Africa, there is no commensurate depletion in δ 18 O compositions of groundwaters of the Ethiopian Plateau. Generally the highland areas north and east of the basin are characterized by relatively depleted δ 18 O groundwaters. Altitudinal depletion of δ 18 O is 0.1%o/100 m. The meteoric waters of the Blue Nile River basin have higher d-excess compared to the meteoric waters of the Ethiopian Rift and that of its White Nile sister basin which emerges from the equatorial lakes region. The geochemically evolved groundwaters of the YTVL and LTG are relatively isotopically depleted when compared to the present day meteoric waters reflecting recharge under colder climate and their high altitude

  19. Groundwater recharge, circulation and geochemical evolution in the source region of the Blue Nile River, Ethiopia

    Energy Technology Data Exchange (ETDEWEB)

    Kebede, Seifu [Laboratory of Hydrogeology, University of Avignon, 33 Rue Louis Pasteur, 84000 Avignon (France) and Department of Geology and Geophysics, Addis Ababa University, P.O. Box 1176, Addis Ababa (Ethiopia)]. E-mail: seifu.kebede@univ-avignon.fr; Travi, Yves [Laboratory of Hydrogeology, University of Avignon, 33 Rue Louis Pasteur, 84000 Avignon (France); Alemayehu, Tamiru [Department of Geology and Geophysics, Addis Ababa University, P.O. Box 1176, Addis Ababa (Ethiopia); Ayenew, Tenalem [Department of Geology and Geophysics, Addis Ababa University, P.O. Box 1176, Addis Ababa (Ethiopia)

    2005-09-15

    Geochemical and environmental isotope data were used to gain the first regional picture of groundwater recharge, circulation and its hydrochemical evolution in the upper Blue Nile River basin of Ethiopia. Q-mode statistical cluster analysis (HCA) was used to classify water into objective groups and to conduct inverse geochemical modeling among the groups. Two major structurally deformed regions with distinct groundwater circulation and evolution history were identified. These are the Lake Tana Graben (LTG) and the Yerer Tullu Wellel Volcanic Lineament Zone (YTVL). Silicate hydrolysis accompanied by CO{sub 2} influx from deeper sources plays a major role in groundwater chemical evolution of the high TDS Na-HCO {sub 3} type thermal groundwaters of these two regions. In the basaltic plateau outside these two zones, groundwater recharge takes place rapidly through fractured basalts, groundwater flow paths are short and they are characterized by low TDS and are Ca-Mg-HCO {sub 3} type waters. Despite the high altitude (mean altitude {approx}2500 masl) and the relatively low mean annual air temperature (18 deg. C) of the region compared to Sahelian Africa, there is no commensurate depletion in {delta} {sup 18}O compositions of groundwaters of the Ethiopian Plateau. Generally the highland areas north and east of the basin are characterized by relatively depleted {delta} {sup 18}O groundwaters. Altitudinal depletion of {delta} {sup 18}O is 0.1%o/100 m. The meteoric waters of the Blue Nile River basin have higher d-excess compared to the meteoric waters of the Ethiopian Rift and that of its White Nile sister basin which emerges from the equatorial lakes region. The geochemically evolved groundwaters of the YTVL and LTG are relatively isotopically depleted when compared to the present day meteoric waters reflecting recharge under colder climate and their high altitude.

  20. Time-Series Analysis of Remotely-Sensed SeaWiFS Chlorophyll in River-Influenced Coastal Regions

    Science.gov (United States)

    Acker, James G.; McMahon, Erin; Shen, Suhung; Hearty, Thomas; Casey, Nancy

    2009-01-01

    The availability of a nearly-continuous record of remotely-sensed chlorophyll a data (chl a) from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) mission, now longer than ten years, enables examination of time-series trends for multiple global locations. Innovative data analysis technology available on the World Wide Web facilitates such analyses. In coastal regions influenced by river outflows, chl a is not always indicative of actual trends in phytoplankton chlorophyll due to the interference of colored dissolved organic matter and suspended sediments; significant chl a timeseries trends for coastal regions influenced by river outflows may nonetheless be indicative of important alterations of the hydrologic and coastal environment. Chl a time-series analysis of nine marine regions influenced by river outflows demonstrates the simplicity and usefulness of this technique. The analyses indicate that coastal time-series are significantly influenced by unusual flood events. Major river systems in regions with relatively low human impact did not exhibit significant trends. Most river systems with demonstrated human impact exhibited significant negative trends, with the noteworthy exception of the Pearl River in China, which has a positive trend.

  1. Detection of petroleum contamination in river sediments from Quebec City region using GC-IRMS

    International Nuclear Information System (INIS)

    Rogers, K.M.; Savard, M.M.

    1999-01-01

    Isotopic analysis by compound specific gas chromatography-isotope ratio mass spectrometry (GC-IRMS) is used to detect and characterize petroleum pollution in surficial sediments along the St Lawrence River, near Quebec City. Unusually mature n-alkane distributions have been found in some recent intertidal sediments in the region. GC-IRMS results suggest that the n-alkanes are not derived from indigenous organic sources because they carry delta 13 C values between -30.0 and -27.0 per mille, as well as very small isotopic differences between odd and even numbered n-alkanes, which are both typically associated with petroleum products. Comparison of these sediments with bunker fuel, an oil used in the shipping industry, has shown a close isotopic correlation in some sites, which is further supported by biomarkers. Overall, the contamination has been dispersed along the river but is generally localized around the industrial region where hydrocarbon transfer from shore storage to ships takes place. This study illustrates how GC-IRMS can be used effectively in the detection and characterization of petroleum pollutants in sediments. (author)

  2. Measurement and Prediction of Regional Tourism Sustainability: An Analysis of the Yangtze River Economic Zone, China

    Directory of Open Access Journals (Sweden)

    Canmian Liu

    2018-04-01

    Full Text Available In view of sustainable development of tourism, this paper firstly constructs a more comprehensive and scientific index system from the economical/societal/resource-related/environmental aspects of tourism and evaluates the sustainable and comprehensive development level of tourism in 11 provinces and cities of the Yangtze River economic zone by using the weighted TOPSIS (The Technique for Order Preference by Similarity to an Ideal Solution method; secondly, it analyzes the coupling coordination evolution relationship between tourism and the economy/society/resources/environment in different provinces and cities of the Yangtze river economic zone based on the coupling coordination model from the spatio-temporal dimension; and finally, it predicts the coupling coordination degree of the provinces and cities in the region in the next few years by the grey model (1,1 and puts forward some countermeasures and suggestions. According to the study, this method provides an effective reference to the study on the sustainable development of tourism and is very significant for learning the sustainable development of regional tourism and establishing specific and scientific countermeasures for improvement.

  3. Managing the three-rivers headwater region, china: from ecological engineering to social engineering.

    Science.gov (United States)

    Fang, Yiping

    2013-09-01

    The three-rivers headwater region (THRHR) of Qinghai province, China plays a key role as source of fresh water and ecosystem services for central and eastern China. Global warming and human activities in the THRHR have threatened the ecosystem since the 1980s. Therefore, the Chinese government has included managing of the THRHR in the national strategy since 2003. The State Integrated Test and Demonstration Region of the THRHR highlights the connection with social engineering (focus on improving people's livelihood and well-being) in managing nature reserves. Based on this program, this perspective attempts a holistic analysis of the strategic role of the THRHR, requirements for change, indices of change, and approaches to change. Long-term success of managing nature reserves requires effective combination of ecological conservation, economic development, and social progress. Thus, the philosophy of social engineering should be employed as a strategy to manage the THRHR.

  4. Visualizing ecological sensitivity assessment of Huangnan, in the Three-river Region, China, based on GIS

    Science.gov (United States)

    Meng, Xia; Guo, Luo

    2017-07-01

    Huangnan Tibetan Autonomous Prefecture is located in the three-river source region (the TRSR) in the Qinghai-Tibetan Plateau, China, which is characterized with ecological sensitivity and vulnerability. In the paper, we integrated remote sensing images, field investigation and social-economic data , and with the help of analytic hierarchy process (AHP) and comprehensive index methods, a sensitivity assessment system was built to calculate ecological sensitivity scores and assign levels for the study area. Results show that: areas which are moderately or even highly ecologically sensitive account for 54.02%, distributed in south, north and northeast of study area and those that have most apparent ecological sensitivity are mainly located in Zeekog, northwest of Huangnan while other counties enjoy relatively lower sensitivity. The results will facilitate future region management and planning for decision-makers.

  5. Emission inventory of anthropogenic air pollutants and VOC species in the Yangtze River Delta region, China

    Directory of Open Access Journals (Sweden)

    C. Huang

    2011-05-01

    Full Text Available The purpose of this study is to develop an emission inventory for major anthropogenic air pollutants and VOC species in the Yangtze River Delta (YRD region for the year 2007. A "bottom-up" methodology was adopted to compile the inventory based on major emission sources in the sixteen cities of this region. Results show that the emissions of SO2, NOx, CO, PM10, PM2.5, VOCs, and NH3 in the YRD region for the year 2007 are 2392 kt, 2293 kt, 6697 kt, 3116 kt, 1511 kt, 2767 kt, and 459 kt, respectively. Ethylene, mp-xylene, o-xylene, toluene, 1,2,4-trimethylbenzene, 2,4-dimethylpentane, ethyl benzene, propylene, 1-pentene, and isoprene are the key species contributing 77 % to the total ozone formation potential (OFP. The spatial distribution of the emissions shows the emissions and OFPs are mainly concentrated in the urban and industrial areas along the Yangtze River and around Hangzhou Bay. The industrial sources, including power plants other fuel combustion facilities, and non-combustion processes contribute about 97 %, 86 %, 89 %, 91 %, and 69 % of the total SO2, NOx, PM10, PM2.5, and VOC emissions. Vehicles take up 12.3 % and 12.4 % of the NOx and VOC emissions, respectively. Regarding OFPs, the chemical industry, domestic use of paint & printing, and gasoline vehicles contribute 38 %, 24 %, and 12 % to the ozone formation in the YRD region.

  6. A simple method to predict regional fish abundance: an example in the McKenzie River Basin, Oregon

    Science.gov (United States)

    D.J. McGarvey; J.M. Johnston

    2011-01-01

    Regional assessments of fisheries resources are increasingly called for, but tools with which to perform them are limited. We present a simple method that can be used to estimate regional carrying capacity and apply it to the McKenzie River Basin, Oregon. First, we use a macroecological model to predict trout densities within small, medium, and large streams in the...

  7. Animal-Borne Imaging Reveals Novel Insights into the Foraging Behaviors and Diel Activity of a Large-Bodied Apex Predator, the American Alligator (Alligator mississippiensis)

    Science.gov (United States)

    Nifong, James C.; Nifong, Rachel L.; Silliman, Brian R.; Lowers, Russell H.; Guillette, Louis J.; Ferguson, Jake M.; Welsh, Matthew; Abernathy, Kyler; Marshall, Greg

    2014-01-01

    Large-bodied, top- and apex predators (e.g., crocodilians, sharks, wolves, killer whales) can exert strong top-down effects within ecological communities through their interactions with prey. Due to inherent difficulties while studying the behavior of these often dangerous predatory species, relatively little is known regarding their feeding behaviors and activity patterns, information that is essential to understanding their role in regulating food web dynamics and ecological processes. Here we use animal-borne imaging systems (Crittercam) to study the foraging behavior and activity patterns of a cryptic, large-bodied predator, the American alligator (Alligator mississippiensis) in two estuaries of coastal Florida, USA. Using retrieved video data we examine the variation in foraging behaviors and activity patterns due to abiotic factors. We found the frequency of prey-attacks (mean = 0.49 prey attacks/hour) as well as the probability of prey-capture success (mean = 0.52 per attack) were significantly affected by time of day. Alligators attempted to capture prey most frequently during the night. Probability of prey-capture success per attack was highest during morning hours and sequentially lower during day, night, and sunset, respectively. Position in the water column also significantly affected prey-capture success, as individuals’ experienced two-fold greater success when attacking prey while submerged. These estimates are the first for wild adult American alligators and one of the few examples for any crocodilian species worldwide. More broadly, these results reveal that our understandings of crocodilian foraging behaviors are biased due to previous studies containing limited observations of cryptic and nocturnal foraging interactions. Our results can be used to inform greater understanding regarding the top-down effects of American alligators in estuarine food webs. Additionally, our results highlight the importance and power of using animal

  8. The effects of hurricane Rita and subsequent drought on alligators in southwest Louisiana.

    Science.gov (United States)

    Lance, Valentine A; Elsey, Ruth M; Butterstein, George; Trosclair, Phillip L; Merchant, Mark

    2010-02-01

    Hurricane Rita struck the coast of southwest Louisiana in September 2005. The storm generated an enormous tidal surge of approximately four meters in height that inundated many thousands of acres of the coastal marsh with full strength seawater. The initial surge resulted in the deaths of a number of alligators and severely stressed those who survived. In addition, a prolonged drought (the lowest rainfall in 111 years of recorded weather data) following the hurricane resulted in highly saline conditions that persisted in the marsh for several months. We had the opportunity to collect 11 blood samples from alligators located on Holly Beach less than a month after the hurricane, but were unable to collect samples from alligators on Rockefeller Wildlife Refuge until February 2006. Conditions at Rockefeller Refuge did not permit systematic sampling, but a total of 201 samples were collected on the refuge up through August 2006. The blood samples were analyzed for sodium, potassium, chloride, osmolality, and corticosterone. Blood samples from alligators sampled on Holly Beach in October 2005, showed a marked elevation in plasma osmolality, sodium, chloride, potassium, corticosterone, and an elevated heterophil/lymphocyte ratio. Blood samples from alligators on Rockefeller Refuge showed increasing levels of corticosterone as the drought persisted and elevated osmolality and electrolytes. After substantial rainfall in July and August, these indices of osmotic stress returned to within normal limits. (c) 2009 Wiley-Liss, Inc.

  9. American alligator digestion rate of blue crabs and its implications for stomach contents analysis

    Science.gov (United States)

    Nifong, James C.; Rosenblatt, Adam E.; Johnson, Nathan A.; Barichivich, William; Silliman, Brian; Heithaus, Michael R.

    2012-01-01

    Stomach contents analysis (SCA) provides a snap-shot observation of a consumer's diet. Interpretation of SCA data can be complicated by many factors, including variation in gastric residence times and digestion rates among prey taxa. Although some SCA methods are reported to efficiently remove all stomach contents, the effectiveness of these techniques has rarely been tested for large irregular shaped prey with hard exoskeletons. We used a controlled feeding trial to estimate gastric residency time and decomposition rate of a large crustacean prey item, the Blue Crab (Callinectes sapidus), which is consumed by American Alligators (Alligator mississippiensis), an abundant apex predator in coastal habitats of the southeastern United States. The decomposition rate of C. sapidus in the stomachs of A. mississippiensis followed a predictable pattern, and some crab pieces remained in stomachs for at least 14 days. We also found that certain portions of C. sapidus were prone to becoming caught within the stomach or esophagus, meaning not all crab parts are consistently recovered using gastric lavage techniques. However, because the state of decomposition of crabs was predictable, it is possible to estimate time since consumption for crabs recovered from wild alligators. This information, coupled with a detailed understanding of crab distributions and alligator movement tactics could help elucidate patterns of cross-ecosystem foraging by the American Alligator in coastal habitats

  10. Thermoregulation and temperature relations of alligators and other large ectotherms inhabiting thermally stressed habitats. Annual progress report, July 1, 1975--June 30, 1976

    Energy Technology Data Exchange (ETDEWEB)

    Spotila, J.R.

    1976-03-01

    The effects of radiation and convection on the equilibrium body temperatures of alligators have been determined. Gaping has been shown to be an effective thermoregulatory device for retarding heat gain in the heads of these animals. Initial time dependent experiments have been completed and ketamine hydrochloride has been shown to be an effective anesthetic for alligators. Evaporative water loss rates have been measured as a function of size, temperature and wind speed for the turtle Chrysemys scripta. Convection coefficients have been determined and climate spaces are being formulated. Field studies are under way at the Savannah River Ecology Laboratory. Convection coefficients for largemouth bass, Micropterus salmoides change as a function of temperature and water speed. Steady state heat energy budgets have been computed for this fish. The effects of arsenic and temperature on the temperature tolerance of larval muskellunge, Esox masquinongy, have been determined. The thermal tolerances of several species of minnows have also been measured. The role of the skin in the control of evaporation from amphibians and reptiles has been assessed. During the past year one article has been published, two are in press, one is in review, and eight are in preparation. Five masters theses will be completed by July 1976.

  11. Thermoregulation and temperature relations of alligators and other large ectotherms inhabiting thermally stressed habitats. Annual progress report, July 1, 1975--June 30, 1976

    International Nuclear Information System (INIS)

    Spotila, J.R.

    1976-03-01

    The effects of radiation and convection on the equilibrium body temperatures of alligators have been determined. Gaping has been shown to be an effective thermoregulatory device for retarding heat gain in the heads of these animals. Initial time dependent experiments have been completed and ketamine hydrochloride has been shown to be an effective anesthetic for alligators. Evaporative water loss rates have been measured as a function of size, temperature and wind speed for the turtle Chrysemys scripta. Convection coefficients have been determined and climate spaces are being formulated. Field studies are under way at the Savannah River Ecology Laboratory. Convection coefficients for largemouth bass, Micropterus salmoides change as a function of temperature and water speed. Steady state heat energy budgets have been computed for this fish. The effects of arsenic and temperature on the temperature tolerance of larval muskellunge, Esox masquinongy, have been determined. The thermal tolerances of several species of minnows have also been measured. The role of the skin in the control of evaporation from amphibians and reptiles has been assessed. During the past year one article has been published, two are in press, one is in review, and eight are in preparation. Five masters theses will be completed by July 1976

  12. Hydrochemistry of the Parauari-Maues Acu river basin (Amazon region, Brazil)

    International Nuclear Information System (INIS)

    Bringel, S.R.B.

    1980-08-01

    The chemical composition of the Parauari-Maues Acu basin is studied through the determination of pH, calcium, magnesium, iron, chloride, sodium, potassium, zinc, copper and manganese. Four expeditions were made and samples were collected in 16 different points of the main course. Chemical analysis of the rivers waters shows seasonal flutuations of the concentrations of the elements in the main river as well as in the main afluents like Nambi river, Amana river and Urupadi river. (Author) [pt

  13. Climatic variability of river outflow in the Pantanal region and the influence of sea surface temperature

    Science.gov (United States)

    Silva, Carlos Batista; Silva, Maria Elisa Siqueira; Ambrizzi, Tércio

    2017-07-01

    This paper investigates possible linear relationships between climate, hydrology, and oceanic surface variability in the Pantanal region (in South America's central area), over interannual and interdecadal time ranges. In order to verify the mentioned relations, lagged correlation analysis and linear adjustment between river discharge at the Pantanal region and sea surface temperature were used. Composite analysis for atmospheric fields, air humidity flux divergence, and atmospheric circulation at low and high levels, for the period between 1970 and 2003, was analyzed. Results suggest that the river discharge in the Pantanal region is linearly associated with interdecadal and interannual oscillations in the Pacific and Atlantic oceans, making them good predictors to continental hydrological variables. Considering oceanic areas, 51 % of the annual discharge in the Pantanal region can be linearly explained by mean sea surface temperature (SST) in the Subtropical North Pacific, Tropical North Pacific, Extratropical South Pacific, and Extratropical North Atlantic over the period. Considering a forecast approach in seasonal scale, 66 % of the monthly discharge variance in Pantanal, 3 months ahead of SST, is explained by the oceanic variables, providing accuracy around 65 %. Annual discharge values in the Pantanal region are strongly related to the Pacific Decadal Oscillation (PDO) variability (with 52 % of linear correlation), making it possible to consider an interdecadal variability and a consequent subdivision of the whole period in three parts: 1st (1970-1977), 2nd (1978-1996), and 3rd (1997-2003) subperiods. The three subperiods coincide with distinct PDO phases: negative, positive, and negative, respectively. Convergence of humidity flux at low levels and the circulation pattern at high levels help to explain the drier and wetter subperiods. During the wetter 2nd subperiod, the air humidity convergence at low levels is much more evident than during the other two

  14. Managing Environmental Flows for Impounded Rivers in Semi-Arid Regions- A Habitat Suitability Index (HSI) Approach for the Assessment of River Habitat for Salmonid Populations

    Science.gov (United States)

    Pai, H.; Sivakumaran, K.; Villamizar, S. R.; Flanagan, J.; Guo, Q.; Harmon, T. C.

    2013-12-01

    Balancing ecosystem health in water-scarce, agriculturally dominated river basins remains a challenge. In dry water years, maintaining conditions for restored and sustained indigenous fish populations (a frequently used indicator for ecosystem health) is particularly challenging. Competing human demands include urban and agricultural water supplies, hydropower, and flood control. In many semi-arid regions, increasing drought intensity and frequency under future climate scenarios will combine with population increases to water scarcity. The goal of this work is to better understand how reservoir releases affect fish habitat and overall river aquatic ecosystem quality. Models integrating a diverse array of physical and biological processes and system state are used to forecast the river ecosystem response to changing drivers. We propose a distributed parameter-based Habitat Suitability Index (HSI) approach for assessing fish habitat quality. Our river ecosystem HSI maps are based on a combination of the following: (1) In situ data describing stream flow and water quality conditions; (2) Spatial observations, including surveyed cross-sections, aerial imagery and digital elevation maps (DEM) of the river and its riparian corridor; and (3) Simulated spatially distributed water depths, flow velocities, and temperatures estimated from 1D and 2D river flow and temperature models (HEC-RAS and CE-QUAL-W2, respectively). With respect to (2), image processing schemes are used to classify and map key habitat features, namely riparian edge and shallow underwater vegetation. HSI maps can be modified temporally to address specific life cycle requirements of indicator fish species. Results are presented for several reaches associated with the San Joaquin River Restoration Project, focusing on several components of the Chinook salmon life cycle. HSI maps and interpretations are presented in the context of a range of prescribed reservoir release hydrographs linked to California water

  15. Simulation of river plume behaviors in a tropical region: Case study of the Upper Gulf of Thailand

    Science.gov (United States)

    Yu, Xiaojie; Guo, Xinyu; Morimoto, Akihiko; Buranapratheprat, Anukul

    2018-02-01

    River plumes are a general phenomenon in coastal regions. Most previous studies focus on river plumes in middle and high latitudes with few studies examining those in low latitude regions. Here, we apply a numerical model to the Upper Gulf of Thailand (UGoT) to examine a river plume in low latitudes. Consistent with observational data, the modeled plume has seasonal variation dependent on monsoon conditions. During southwesterly monsoons, the plume extends northeastward to the head of the gulf; during northeasterly monsoons, it extends southwestward to the mouth of the gulf. To examine the effects of latitude, wind and river discharge on the river plume, we designed several numerical experiments. Using a middle latitude for the UGoT, the bulge close to the river mouth becomes smaller, the downstream current flows closer to the coast, and the salinity in the northern UGoT becomes lower. The reduction in the size of the bulge is consistent with the relationship between the offshore distance of a bulge and the Coriolis parameter. Momentum balance of the coastal current is maintained by advection, the Coriolis force, pressure gradient and internal stresses in both low and middle latitudes, with the Coriolis force and pressure gradient enlarged in the middle latitude. The larger pressure gradient in the middle latitude is induced by more offshore freshwater flowing with the coastal current, which induces lower salinity. The influence of wind on the river plume not only has the advection effects of changing the surface current direction and increasing the surface current speed, but also decreases the current speed due to enhanced vertical mixing. Changes in river discharge influence stratification in the UGoT but have little effect on the behavior of the river plume.

  16. Regional hydrology of the Dolores River Basin, eastern Paradox Basin, Colorado and Utah

    International Nuclear Information System (INIS)

    Weir, J.E. Jr.; Maxfield, E.B.; Zimmerman, E.A.

    1983-01-01

    The Dolores River Basin, is in the eastern part of the Paradox Basin and includes the eastern slope of the La Sal Mountains, the western slopes of the Rico and La Plata Mountains, and the southwest flank of the Uncompahgre Plateau. The climate of this area is more humid than most of the surrounding Colorado Plateau region. Precipitation ranges from slightly 200 mm/yr to 1000 mm/yr; the estimated volume of water falling on the area is 4000 x 10 6 cm 3 /yr. Of this total, about 600 x 10 6 cm 3 /yr is runoff; 190 x 10 6 cm 3 /yr recharges the upper ground-water system; and an estimated 55 x 10 6 cm 3 returns to the atmosphere via evapotranspiration from stream valleys. The remainder evaporates. Principal hydrogeologic units are permeable sandstone and limestone and nearly impermeable salt (halitic) deposits. Structurally, the area is dominated by northwest-trending salt anticlines and contiguous faults paralleled by synclinal structures. The Uncompahgre Plateau lies along the north and northeast sides of the area. The instrusive masses that form the La Sal Mountains are laccoliths with bysmaliths and other complex intrusive forms comprising, in gross form, moderately faulted omal structures. Intrusive rocks underlie the La Plata and Rico Mountains along the southeastern edge of the area. These geologic structures significantly modify ground-water flow patterns in the upper ground-water system, but have no conspicuous effect on the flow regime in the lower ground-water system. The water in the upper ground-water system generally is fresh except where it is affected by evaporite dissolution from salt anticlines. The water of the lower ground-water system is slightly saline to briny. Water quality of the Dolores River is slightly saline to fresh, based on dissolved chemical constituents; some of the smaller tributaries of the river have saline water

  17. Regional dynamics of persistent organic pollutants (POPs) in the Pearl River Delta, China: Implications and perspectives

    International Nuclear Information System (INIS)

    Zhang Kai; Zhang Baozhong; Li Shaomeng; Zeng, Eddy Y.

    2011-01-01

    The mass transport budgets of 1,1,1-trichloro-2,2-bis(chlorophenyl)ethane (p,p'-DDT) and decabromodiphenyl ether (BDE-209) in the Pearl River Delta, South China were calculated based on previously collected data. Residual p,p'-DDT, mostly related to historical use, has largely settled into soil (780,000 kg), while the soil BDE-209 inventory (44,000 kg) is considerably smaller. Conversely, large amounts of BDE-209 currently used in numerous commercial products have resulted in a much higher atmospheric depositional flux of BDE-209 (28,100 kg/yr) relative to p,p'-DDT (310 kg/yr). The soil inventory of p,p'-DDT is predicted to decrease to half of its current value after 22 years, and the percent area containing soil p,p'-DDT at levels exceeding the effects range-medium (27 ng/g) will decrease from 40% to 20%. Finally, soil BDE-209 inventory will reach an equilibrium value of 940 tons in ∼60 years, when BDE-209 levels in 50% of soil will be above an equivalent risk guideline value (125 ng/g). - Highlights: → Transport budgets of p,p'-DDT and BDE-209 in the Pearl River Delta were built. → Dry aerial deposition is the dominant route to transport p,p'-DDT and BDE-209. → Soil inventory of p,p'-DDT is much larger than that of BDE-209. → Soil inventory of p,p'-DDT would decline to half of its current value in 22 years. → Soil BDE-209 inventory is expected to reach an equilibrium value in ∼60 years. - Regional dynamics of p,p'-DDT and BDE-209 in the Pearl River Delta (South China) are examined and used to predict temporal variances.

  18. Global surveys of reservoirs and lakes from satellites and regional application to the Syrdarya river basin

    International Nuclear Information System (INIS)

    Jean-François, Crétaux; Adalbert, Arsen; Muriel, Bergé-Nguyen; Sylvain, Biancamaria; Mélanie, Becker

    2015-01-01

    Large reservoirs along rivers regulate downstream flows to generate hydropower but may also store water for irrigation and urban sectors. Reservoir management therefore becomes critical, particularly for transboundary basins, where coordination between riparian countries is needed. Reservoir management is even more important in semiarid regions where downstream water users may be totally reliant on upstream reservoir releases. If the water resources are shared between upstream and downstream countries, potentially opposite interests arise as is the case in the Syrdarya river in Central Asia. In this case study, remote sensing data (radar altimetry and optical imagery) are used to highlight the potential of satellite data to monitor water resources: water height, areal extent and storage variations. New results from 20 years of monitoring using satellites over the Syrdarya basin are presented. The accuracy of satellite data is 0.6 km 3 using a combination of MODIS data and satellite altimetry, and only 0.2 km 3 with Landsat images representing 2–4% of average annual reservoir volume variations in the reservoirs in the Syrdarya basin. With future missions such as Sentinel-3A (S3A), Sentinel-3B (S3B) and surface water and ocean topography (SWOT), significant improvement is expected. The SWOT mission’s main payload (a radar interferometer in Ka band) will furthermore provide 2D maps of water height, reservoirs, lakes, rivers and floodplains, with a temporal resolution of 21 days. At the global scale, the SWOT mission will cover reservoirs with areal extents greater than 250  ×  250 m with 20 cm accuracy. (letter)

  19. Global surveys of reservoirs and lakes from satellites and regional application to the Syrdarya river basin

    Science.gov (United States)

    Jean-François, Crétaux; Sylvain, Biancamaria; Adalbert, Arsen; Muriel, Bergé-Nguyen; Mélanie, Becker

    2015-01-01

    Large reservoirs along rivers regulate downstream flows to generate hydropower but may also store water for irrigation and urban sectors. Reservoir management therefore becomes critical, particularly for transboundary basins, where coordination between riparian countries is needed. Reservoir management is even more important in semiarid regions where downstream water users may be totally reliant on upstream reservoir releases. If the water resources are shared between upstream and downstream countries, potentially opposite interests arise as is the case in the Syrdarya river in Central Asia. In this case study, remote sensing data (radar altimetry and optical imagery) are used to highlight the potential of satellite data to monitor water resources: water height, areal extent and storage variations. New results from 20 years of monitoring using satellites over the Syrdarya basin are presented. The accuracy of satellite data is 0.6 km3 using a combination of MODIS data and satellite altimetry, and only 0.2 km3 with Landsat images representing 2-4% of average annual reservoir volume variations in the reservoirs in the Syrdarya basin. With future missions such as Sentinel-3A (S3A), Sentinel-3B (S3B) and surface water and ocean topography (SWOT), significant improvement is expected. The SWOT mission’s main payload (a radar interferometer in Ka band) will furthermore provide 2D maps of water height, reservoirs, lakes, rivers and floodplains, with a temporal resolution of 21 days. At the global scale, the SWOT mission will cover reservoirs with areal extents greater than 250 × 250 m with 20 cm accuracy.

  20. Spatial Differentiation of Landscape Values in the Murray River Region of Victoria, Australia

    Science.gov (United States)

    Zhu, Xuan; Pfueller, Sharron; Whitelaw, Paul; Winter, Caroline

    2010-05-01

    This research advances the understanding of the location of perceived landscape values through a statistically based approach to spatial analysis of value densities. Survey data were obtained from a sample of people living in and using the Murray River region, Australia, where declining environmental quality prompted a reevaluation of its conservation status. When densities of 12 perceived landscape values were mapped using geographic information systems (GIS), valued places clustered along the entire river bank and in associated National/State Parks and reserves. While simple density mapping revealed high value densities in various locations, it did not indicate what density of a landscape value could be regarded as a statistically significant hotspot or distinguish whether overlapping areas of high density for different values indicate identical or adjacent locations. A spatial statistic Getis-Ord Gi* was used to indicate statistically significant spatial clusters of high value densities or “hotspots”. Of 251 hotspots, 40% were for single non-use values, primarily spiritual, therapeutic or intrinsic. Four hotspots had 11 landscape values. Two, lacking economic value, were located in ecologically important river red gum forests and two, lacking wilderness value, were near the major towns of Echuca-Moama and Albury-Wodonga. Hotspots for eight values showed statistically significant associations with another value. There were high associations between learning and heritage values while economic and biological diversity values showed moderate associations with several other direct and indirect use values. This approach may improve confidence in the interpretation of spatial analysis of landscape values by enhancing understanding of value relationships.

  1. Impacts of urban and industrial development on Arctic land surface temperature in Lower Yenisei River Region.

    Science.gov (United States)

    Li, Z.; Shiklomanov, N. I.

    2015-12-01

    Urbanization and industrial development have significant impacts on arctic climate that in turn controls settlement patterns and socio-economic processes. In this study we have analyzed the anthropogenic influences on regional land surface temperature of Lower Yenisei River Region of the Russia Arctic. The study area covers two consecutive Landsat scenes and includes three major cities: Norilsk, Igarka and Dudingka. Norilsk industrial region is the largest producer of nickel and palladium in the world, and Igarka and Dudingka are important ports for shipping. We constructed a spatio-temporal interpolated temperature model by including 1km MODIS LST, field-measured climate, Modern Era Retrospective-analysis for Research and Applications (MERRA), DEM, Landsat NDVI and Landsat Land Cover. Those fore-mentioned spatial data have various resolution and coverage in both time and space. We analyzed their relationships and created a monthly spatio-temporal interpolated surface temperature model at 1km resolution from 1980 to 2010. The temperature model then was used to examine the characteristic seasonal LST signatures, related to several representative assemblages of Arctic urban and industrial infrastructure in order to quantify anthropogenic influence on regional surface temperature.

  2. Summary of the Snake River plain Regional Aquifer-System Analysis in Idaho and eastern Oregon

    Science.gov (United States)

    Lindholm, G.F.

    1996-01-01

    Regional aquifers underlying the 15,600-square-mile Snake River Plain in southern Idaho and eastern Oregon was studied as part of the U.S. Geological Survey's Regional Aquifer-System Analysis program. The largest and most productive aquifers in the Snake River Plain are composed of Quaternary basalt of the Snake River Group, which underlies most of the 10,8000-square-mile eastern plain. Aquifer tests and simulation indicate that transmissivity of the upper 200 feet of the basalt aquifer in the eastern plain commonly ranges from about 100,000 to 1,000,000 feet squared per day. However, transmissivity of the total aquifer thickness may be as much as 10 million feet squared per day. Specific yield of the upper 200 feet of the aquifer ranges from about 0.01 to 0.20. Average horizontal hydraulic conductivity of the upper 200 feet of the basalt aquifer ranges from less than 100 to 9,000 feet per day. Values may be one to several orders of magnitude higher in parts in individual flows, such as flow tops. Vertical hydraulic conductivity is probably several orders of magnitude lower than horizontal hydraulic conductivity and is generally related to the number of joints. Pillow lava in ancestral Snake River channels has the highest hydraulic conductivity of all rock types. Hydraulic conductivity of the basalt decreases with depth because of secondary filling of voids with calcite and silica. An estimated 80 to 120 million acre-feet of water is believed to be stored in the upper 200 feet of the basalt aquifer in the eastern plain. The most productive aquifers in the 4,800-square-mile western plain are alluvial sand and gravel in the Boise River valley. Although aquifer tests indicate that transmissivity of alluvium in the Boise River valley ranges from 5,000 to 160,000 feet squared per day, simulation suggests that average transmissivity of the upper 500 feet is generally less than 20,000 feet squared per day. Vertically averaged horizontal hydraulic conductivity of the upper

  3. Regional hydrology of the Green River-Moab area, northwestern Paradox Basin, Utah

    International Nuclear Information System (INIS)

    Rush, F.E.; Whitfield, M.S.; Hart, I.M.

    1982-12-01

    The Green River-Moab area encompasses about 7800 square kilometers or about 25% of the Paradox basin. The entire Paradox basin is a part of the Colorado Plateaus that is underlain by a thick sequence of evaporite (salt) beds of Pennsylvanian age. The rock units that underlie the area have been grouped into hydrogeologic units based on their water-transmitting ability. Confining beds consist of evaporite beds of mostly salt, and overlying and underlying thick sequences of rocks with minimal permeability; above and below these confining beds are aquifers. The upper Mesozoic sandstone aquifer, probably is the most permeable hydrogeologic unit of the area and is the subject of this investigation. The principal component of groundwater outflow from this aquifer probably is subsurface flow to regional streams (the Green and Colorado Rivers) and is about 100 million cubic meters per year. All other components of outflow are relatively small. The average annual recharge to the aquifer is about 130 million cubic meters, of which about 20 million cubic meters is from local precipitation. For the lower aquifer, all recharge and discharge probably is by subsurface flow and was not estimated. The aquifers are generally isolated from the evaporite beds by the bounding confining beds; as a result, most ground water has little if any contact with the evaporites. Brines are present in the confining beds, but solution of beds of salt probably is very slow in most parts of the area. No brine discharges have been identified

  4. Science-policy interplay: Air quality management in the Pearl River Delta region and Hong Kong

    Science.gov (United States)

    Zhong, Liuju; Louie, Peter K. K.; Zheng, Junyu; Yuan, Zibing; Yue, Dingli; Ho, Josephine W. K.; Lau, Alexis K. H.

    2013-09-01

    The information provided by the scientific studies and control measures implemented in the Pearl River Delta (PRD) region of China reveals that tremendous progress has been made in the understanding of regional air pollution issues and the deployment of mitigation measures for alleviating these problems. Given the unparalleled rapid economic growth in the PRD over the past two decades, such progress was only made possible by strong, science-based support and the partnerships between government and research institutions in the region and overseas. Researchers from these partnership programs and related studies have deployed cutting-edge expertise and experience in various crucial mainland China and mainland China/Hong Kong-level projects. China recognizes the importance of protecting the environment and cleaning up the air in the pursuit of sustainable growth and economic development. To avoid falling into a cycle of event-driven clean-up efforts, China has recently taken a major step and updated the national ambient air quality standards. Clearly, China is implementing an increasing number of evidence-based policies to address air pollution problems. Thus, to bring a fresh impetus at a national level, the PRD must maintain and augment the Hong Kong-mainland collaborative momentum, inducing a "whole-China" effort to clean up air pollution. To strengthen the science-based support system and ensure continuous and concerted effort in implementing the regional multi-pollutant control strategy, there must be an overarching and integral Hong Kong-Guangdong science consortium framework supporting the formulation of regional policy and control measures built on common goals under the "one country, two systems" principle. The "PRD Approach" of the air quality management regime reflected regional cooperative efforts in synchronous air pollutant control, catalyzed the crucial role of information disclosure and subtly transformed the air quality management approach to overcome

  5. Improving Shade Modelling in a Regional River Temperature Model Using Fine-Scale LIDAR Data

    Science.gov (United States)

    Hannah, D. M.; Loicq, P.; Moatar, F.; Beaufort, A.; Melin, E.; Jullian, Y.

    2015-12-01

    Air temperature is often considered as a proxy of the stream temperature to model the distribution areas of aquatic species water temperature is not available at a regional scale. To simulate the water temperature at a regional scale (105 km²), a physically-based model using the equilibrium temperature concept and including upstream-downstream propagation of the thermal signal was developed and applied to the entire Loire basin (Beaufort et al., submitted). This model, called T-NET (Temperature-NETwork) is based on a hydrographical network topology. Computations are made hourly on 52,000 reaches which average 1.7 km long in the Loire drainage basin. The model gives a median Root Mean Square Error of 1.8°C at hourly time step on the basis of 128 water temperature stations (2008-2012). In that version of the model, tree shadings is modelled by a constant factor proportional to the vegetation cover on 10 meters sides the river reaches. According to sensitivity analysis, improving the shade representation would enhance T-NET accuracy, especially for the maximum daily temperatures, which are currently not very well modelized. This study evaluates the most efficient way (accuracy/computing time) to improve the shade model thanks to 1-m resolution LIDAR data available on tributary of the LoireRiver (317 km long and an area of 8280 km²). Two methods are tested and compared: the first one is a spatially explicit computation of the cast shadow for every LIDAR pixel. The second is based on averaged vegetation cover characteristics of buffers and reaches of variable size. Validation of the water temperature model is made against 4 temperature sensors well spread along the stream, as well as two airborne thermal infrared imageries acquired in summer 2014 and winter 2015 over a 80 km reach. The poster will present the optimal length- and crosswise scale to characterize the vegetation from LIDAR data.

  6. Practical possibility to manage radiation pollution on the examples of the region of Krivoy Rog and Loire river

    Energy Technology Data Exchange (ETDEWEB)

    Sizonenko, V. [Institute of General Energy of NAS of Ukraine (Ukraine)

    2014-07-01

    Uranium deposit placed near-by Zoltje Vody City in the region of Krivoy Rog is one of most on territory of Ukraine. One of main mining objects of the city is a mine 'Nova', which works mine of ferrous and uranium ores. Mine water which is pumped out on a surface is saturated by uranium is used for the technological necessities of mining complex and finally is thrown down in a Zoltaja River. This results in contamination of waters of Ingulets River (tributary of the Dnieper River) and Karachunovskoe reservoir - of the basic source of water-supply of whole region. The paper will show possibilities for managing of possible consequences of accidental events of volley inflow of the muddy mine waters in Zoltaja River, prognostication of possible consequences of such catastrophic situations. The computer model of the water system of region Zoltje Vody City - Krivoy Rog City has been developed with usage of the new box model of incomplete inter-fusion with lagging argument. It gave the opportunity for accurate prognostication and short time of preparedness. Examples of prognostication of levels of concentrations of radionuclide ({sup 238}U) in waters of the Ingulets River, Zoltaja River and Karachunovskoe reservoir depending on the discharges of water of rivers and modes (regulation and catastrophic) of polluted water kick of mine 'Nova' are demonstrated. Possibilities of water protection actions are explored at the catastrophic discharge of mine water to Zoltaja River. Protection action is dilution by waters from the storage pool of Ingulets River. Such measures in many cases enable to access to safe and adequate water and sanitation services during the catastrophic events. The practical efforts for mitigation of consequences of the protracted catastrophic manmade influence on a water environment and possibilities of rehabilitation of the water system in the whole region of Krivoy Rog were analyzed in the work. The research of emissions tritium in the

  7. Estimating Error in SRTM Derived Planform of a River in Data-poor Region and Subsequent Impact on Inundation Modeling

    Science.gov (United States)

    Bhuyian, M. N. M.; Kalyanapu, A. J.

    2017-12-01

    Accurate representation of river planform is critical for hydrodynamic modeling. Digital elevation models (DEM) often falls short in accurately representing river planform because they show the ground as it was during data acquisition. But, water bodies (i.e. rivers) change their size and shape over time. River planforms are more dynamic in undisturbed riverine systems (mostly located in data-poor regions) where remote sensing is the most convenient source of data. For many of such regions, Shuttle Radar Topographic Mission (SRTM) is the best available source of DEM. Therefore, the objective of this study is to estimate the error in SRTM derived planform of a river in a data-poor region and estimate the subsequent impact on inundation modeling. Analysis of Landsat image, SRTM DEM and remotely sensed soil data was used to classify the planform activity in an 185 km stretch of the Kushiyara River in Bangladesh. In last 15 years, the river eroded about 4.65 square km and deposited 7.55 square km area. Therefore, current (the year 2017) river planform is significantly different than the SRTM water body data which represents the time of SRTM data acquisition (the year 2000). The rate of planform shifting significantly increased as the river traveled to downstream. Therefore, the study area was divided into three reaches (R1, R2, and R3) from upstream to downstream. Channel slope and meandering ratio changed from 2x10-7 and 1.64 in R1 to 1x10-4 and 1.45 in R3. However, more than 60% erosion-deposition occurred in R3 where a high percentage of Fluvisols (98%) and coarse particles (21%) were present in the vicinity of the river. It indicates errors in SRTM water body data (due to planform shifting) could be correlated with the physical properties (i.e. slope, soil type, meandering ratio etc.) of the riverine system. The correlations would help in zoning activity of a riverine system and determine a timeline to update DEM for a given region. Additionally, to estimate the

  8. VOCs and OVOCs distribution and control policy implications in Pearl River Delta region, China

    Science.gov (United States)

    Louie, Peter K. K.; Ho, Josephine W. K.; Tsang, Roy C. W.; Blake, Donald R.; Lau, Alexis K. H.; Yu, Jian Zhen; Yuan, Zibing; Wang, Xinming; Shao, Min; Zhong, Liuju

    2013-09-01

    Ambient air measurements of volatile organic compounds (VOCs) and oxygenated volatile organic compounds (OVOCs) were conducted and characterised during a two-year grid study in the Pearl River Delta (PRD) region of southern China. The present grid study pioneered the systematic investigation of the nature and characteristics of complex VOC and OVOC sources at a regional scale. The largest contributing VOCs, accounting over 80% of the total VOCs mixing ratio, were toluene, ethane, ethyne, propane, ethene, butane, benzene, pentane, ethylbenzene, and xylenes. Sub-regional VOC spatial characteristics were identified, namely: i) relatively fresh pollutants, consistent with elevated vehicular and industrial activities, around the PRD estuary; and ii) a concentration gradient with higher mixing ratios of VOCs in the west as compared with the eastern part of PRD. Based on alkyl nitrate aging determination, a high hydroxyl radical (OH) concentration favoured fast hydrocarbon reactions and formation of locally produced ozone. The photochemical reactivity analysis showed aromatic hydrocarbons and alkenes together consisted of around 80% of the ozone formation potential (OFP) among the key VOCs. We also found that the OFP from OVOCs should not be neglected since their OFP contribution was more than one-third of that from VOCs alone. These findings support the choice of current air pollution control policy which focuses on vehicular sources but warrants further controls. Industrial emissions and VOCs emitted by solvents should be the next targets for ground-level ozone abatement.

  9. Water hyacinths and alligator weeds for removal of silver, cobalt, and strontium from polluted waters

    Science.gov (United States)

    Wolverton, B. C.; Mcdonald, R. C.

    1975-01-01

    Water hyacinths and alligator weeds demonstrated the ability to rapidly remove heavy metals from an aqueous system by root absorption and concentration. Water hyacinths demonstrated the ability to remove 0.439 mg of silver, 0.568 mg of cobalt, and 0.544 mg of strontium in an ionized form per gram of dry plant material in a 24-hour period. Alligator weeds removed a maximum of 0.439 mg of silver, 0.130 mg of cobalt, and 0.161 mg of strontium per gram of dry plant material per day.

  10. Characteristics of carbonaceous aerosol in PM 2.5: Pearl Delta River Region, China

    Science.gov (United States)

    Huang, H.; Ho, K. F.; Lee, S. C.; Tsang, P. K.; Ho, Steven Sai Hang; Zou, C. W.; Zou, S. C.; Cao, J. J.; Xu, H. M.

    2012-02-01

    Simultaneous measurements of atmospheric organic carbon (OC), elemental carbon (EC) and water-soluble organic carbon (WSOC) were made at four sampling sites, namely Guangzhou (GZ), Zhaoqing (ZQ), PolyU Campus (PU) and Hok Tsui (HT), in the Pearl River Delta (PRD) region between 14 August 2006 and 28 August 2007. The highest concentrations of total carbon (TC) were found at the medium-scale roadside site (PU) and the lowest were found at the regional-scale site (HT). Among the four sampling sites, the average WSOC at ZQ showed the highest concentrations, while the lowest were seen at HT. OC and EC concentrations revealed spring/summer minima and autumn/winter maxima at all sites except PU, which had a consistently high EC concentration all over the year. The highest WSOC/OC ratio was found at ZQ with an average of 0.41, suggesting that the OC was more oxidized in the atmosphere of the semi-rural site. The lowest WSOC/OC was found at the roadside site of PU. Moreover, the WSOC/OC ratio increased in autumn, when the photochemical reactions are the most active in the PRD region. This can be attributed to aging and atmospheric processing of the organic compounds during their transportation, or to the formation of secondary organic aerosol (SOA). Average annual secondary organic carbon (SOC) concentrations in PM2.5 were estimated to be 2.2 and 3.5 μg m- 3 for GZ and ZQ, comprising 33.5% and 42.8% of the corresponding OC concentrations, respectively. The results indicate that SOC is significant in the PRD region, and its formation mostly occurs within the region.

  11. A crucial role of paralogous β-defensin genes in the Chinese alligator innate immune system revealed by the first determination of a Crocodilia defensin cluster.

    Science.gov (United States)

    Tang, Ke-Yi; Wang, Xin; Wan, Qiu-Hong; Fang, Sheng-Guo

    2018-04-01

    The β-defensin, one of the antimicrobial peptides (AMPs), is a significant component of the innate immune with a broad range of antimicrobial activities. Differing from the widely-studied mammals and birds, limited information about β-defensins has been reported in reptiles, especially in crocodilians. As a same ancient species as dinosaurs and the most endangered species of 23 crocodilians, the survival of Chinese alligator (Alligator sinensis) means a powerful immune system and possible involvement of AMPs in its immune resistance. In this study, we identified 20 novel Alligator sinensisβ-defensin genes (AsBDs) from a 390 kb region using bioinformatic and experimental approaches, and successfully distinguished six orthologous AsBDs to birds and nine paralogous AsBDs undergoing gene duplication events. The amino acid alignment shows that the AsBD paralogs, like α-defensins, encode a significantly longer pro-piece comparing with the orthologs. The calculation of non-synonymous (d N ) and synonymous (d S ) substitutions in the mature peptide reveals that the AsBD paralogs experience a significantly higher selective pressure (d N /d S ) than the orthologs, but a similar evolutionary force to α-defensins. The gene expression result indicates that the AsBD paralogs have a significantly higher expression level than the orthologos in gastrointestinal tract where the host is vulnerable to enteric pathogenic bacteria, as observed in α-defensins. These three pieces of evidence demonstrate that the AsBD paralogs do play an important role in maintaining long-term survival of this endangered reptile. Thus, this survey of AsBDs on the genomic structure, evolutionary characteristics, and expression pattern provides a genetic and immunological foundation for further investigating their antimicrobial function and alternative antibiotics potentiality. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  12. Evolution of regional stress state based on faulting and folding near the pit river, Shasta county, California

    Science.gov (United States)

    Austin, Lauren Jean

    We investigate the evolution of the regional stress state near the Pit River, northern California, in order to understand the faulting style in a tectonic transition zone and to inform the hazard analysis of Fault 3432 near the Pit 3 Dam. By analyzing faults and folds preserved in and adjacent to a diatomite mine north of the Pit River, we have determined principal stress directions preserved during the past million years. We find that the stress state has evolved from predominantly normal to strike slip and most recently to reverse, which is consistent with regional structures such as the extensional Hat Creek Fault to the south and the compressional folding of Mushroom Rock to the north. South of the Pit River, we still observe normal and strike slip faults, suggesting that changes in stress state are moving from north to south through time.

  13. Dissolution and Release of Gaseous Nitrogen (N2, N2O) in the Source Region of the Yellow River

    Science.gov (United States)

    Zhang, L.; Xia, X.; Wang, J.

    2017-12-01

    Nitrogen is an important biogenic element. The migration and transformation of nitrogen in rivers is an important process affecting global nitrogen cycling and greenhouse gas emissions. However, there is a lack of research on nitrogen removal and greenhouse gas emission characteristics of high altitude rivers. In this work, the spatial and temporal variations of dissolved nitrogen (N2 and N2O) concentrations, saturation, and release flux as well as their responses to environmental factors were studied in the Yellow River source area, a typical high altitude river. The results showed that the dissolved concentrations of N2 and N2O in the rivers were 8.24-137.75 μmol.L-1 and 2.57-31.94 nmol.L-1, respectively. N2 and N2O saturation were greater than 100% for all the sampling sites, indicating that the river is a release source for atmosphere N2 and N2O. Correspondingly, the fluxes of N2 and N2O from river water to atmosphere were 24.12-1606.57 mmol (m2.d) -1 and 12.96-276.81 μmol (m2.d) -1, respectively. Generally, the dissolution concentration and release flux of N2 and N2O in July were larger than that in May. The concentrations of N2 and N2O in river water were related to the environmental factors, and the dissolved concentration of N2 in the surface water was significantly positively correlated with water temperature, NH4+-N and total inorganic nitrogen (DIN) (p<0.01). The dissolved concentration of N2O was significantly positively correlated with the content of suspended particulates, DO, and DIN (p<0.01). Thus, DIN is a key factor in the process of N2 and N2O formation. This study can help to understand the nitrogen cycling in high-altitude rivers and provide basic data for a comprehensive assessment of global river nitrogen loss. Key Words: Source Region of the Yellow River; Gaseous Nitrogen; Nitrogen loss; High altitude river

  14. Ontogeny of the Alligator Cartilago Transiliens and Its Significance for Sauropsid Jaw Muscle Evolution

    Science.gov (United States)

    Tsai, Henry P.; Holliday, Casey M.

    2011-01-01

    The cartilago transiliens is a fibrocartilaginous structure within the jaw muscles of crocodylians. The cartilago transiliens slides between the pterygoid buttress and coronoid region of the lower jaw and connects two muscles historically identified as m. pseudotemporalis superficialis and m. intramandibularis. However, the position of cartilago transiliens, and its anatomical similarities to tendon organs suggest the structure may be a sesamoid linking a single muscle. Incompressible sesamoids often form inside tendons that wrap around bone. However, such structures rarely ossify in reptiles and have thus far received scant attention. We tested the hypothesis that the cartilago transiliens is a sesamoid developed within in one muscle by investigating its structure in an ontogenetic series of Alligator mississippiensis using dissection, 3D imaging, and polarizing and standard light microscopy. In all animals studied, the cartilago transiliens receives collagen fibers and tendon insertions from its two main muscular attachments. However, whereas collagen fibers were continuous within the cartilaginous nodule of younger animals, such continuity decreased in older animals, where the fibrocartilaginous core grew to displace the fibrous region. Whereas several neighboring muscles attached to the fibrous capsule in older individuals, only two muscles had significant contributions to the structure in young animals. Our results indicate that the cartilago transiliens is likely a sesamoid formed within a single muscle (i.e., m. pseudotemporalis superficialis) as it wraps around the pterygoid buttress. This tendon organ is ubiquitous among fossil crocodyliforms indicating it is a relatively ancient, conserved structure associated with the development of the large pterygoid flanges in this clade. Finally, these findings indicate that similar tendon organs exist among potentially homologous muscle groups in birds and turtles, thus impacting inferences of jaw muscle homology

  15. Seasonally and regionally determined indication potential of bioassays in contaminated river sediments.

    Science.gov (United States)

    Hilscherová, Klára; Dusek, Ladislav; Sídlová, Tereza; Jálová, Veronika; Cupr, Pavel; Giesy, John P; Nehyba, Slavomír; Jarkovský, Jirí; Klánová, Jana; Holoubek, Ivan

    2010-03-01

    River sediments are a dynamic system, especially in areas where floods occur frequently. In the present study, an integrative approach is used to investigate the seasonal and spatial dynamics of contamination of sediments from a regularly flooded industrial area in the Czech Republic, which presents a suitable model ecosystem for pollutant distribution research at a regional level. Surface sediments were sampled repeatedly to represent two different hydrological situations: spring (after the peak of high flow) and autumn (after longer period of low flow). Samples were characterized for abiotic parameters and concentrations of priority organic pollutants. Toxicity was assessed by Microtox test; genotoxicity by SOS-chromotest and green fluorescent protein (GFP)-yeast test; and the presence of compounds with specific mode of action by in vitro bioassays for dioxin-like activity, anti-/androgenicity, and anti-/estrogenicity. Distribution of organic contaminants varied among regions and seasonally. Although the results of Microtox and genotoxicity tests were relatively inconclusive, all other specific bioassays led to statistically significant regional and seasonal differences in profiles and allowed clear separation of upstream and downstream regions. The outcomes of these bioassays indicated an association with concentrations of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) as master variables. There were significant interrelations among dioxin-like activity, antiandrogenicity and content of organic carbon, clay, and concentration of PAHs and PCBs, which documents the significance of abiotic factors in accumulation of pollutants. The study demonstrates the strength of the specific bioassays in indicating the changes in contamination and emphasizes the crucial role of a well-designed sampling plan, in which both spatial and temporal dynamics should be taken into account, for the correct interpretations of information in risk assessments.

  16. High resolution of black carbon and organic carbon emissions in the Pearl River Delta region, China.

    Science.gov (United States)

    Zheng, Junyu; He, Min; Shen, Xingling; Yin, Shasha; Yuan, Zibing

    2012-11-01

    A high-resolution regional black carbon (BC) and organic carbon (OC) emission inventory for the year 2009 was developed for the Pearl River Delta (PRD) region, China, based on the collected activity data and the latest emission factors. PM(2.5), BC and OC emissions were estimated to be 303 kt, 39 kt and 31 kt, respectively. Industrial processes were major contributing sources to PM(2.5) emissions. BC emissions were mainly from mobile sources, accounting for 65.0%, while 34.1% of OC emissions were from residential combustion. The primary OC/BC ratios for individual cities in the PRD region were dependent on the levels of economic development due to differences in source characteristics, with high ratios in the less developed cities and low ratios in the central and southern developed areas. The preliminary temporal profiles were established, showing the highest OC emissions in winter and relatively constant BC emissions throughout the year. The emissions were spatially allocated into grid cells with a resolution of 3 km × 3 km. Large amounts of BC emissions were distributed over the central-southern PRD city clusters, while OC emissions exhibited a relatively even spatial distribution due to the significant biomass burning emissions from the outlying area of the PRD region. Uncertainties in carbonaceous aerosol emissions were usually higher than in other primary pollutants like SO(2), NO(x), and PM(10). One of the key uncertainty sources was the emission factor, due to the absence of direct measurements of BC and OC emission rates. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Regional Ecological Risk Assessment in the Huai River Watershed during 2010–2015

    Directory of Open Access Journals (Sweden)

    Yan Lu

    2017-12-01

    Full Text Available Ecosystem deterioration has been and is still a serious threat to human survival and regional economic development. Theoretical and methodological challenges exist in assessing ecological risk of watershed ecosystem that is imposed by natural changes or human activities. To fill this research gap, this research proposes an interdisciplinary and quantitative methodology based on some techniques such as the Procedure for Ecological Tiered Assessment of Risk (PETAR, the Entropy, and the Celluar Automata Markov (CA-Markov. We focused on six vulnerable environmental variables, namely land-use change, water quantity, water quality, gross domestic product (GDP, environmental pollutants, and soil erosion in the Huai River watershed in the Henan Province in order to build multi-dimensional quantitative method. Further, the Coupling Coordination Degree Model is constructed, and the “threshold index” is also addressed to reflect the limitation of ecological risk. Our results show that the spatio-temperal distribution of the eco-environmental quality has greatly varied across this study area during different time spans. Natural eco-environmental quality has moderately degraded in 70% of this study area (mainly agricultural region, at a prefectural level from 2000 to 2010, and has slightly improved over the agricultural region (<170 m above sea level during 2010–2015. However, when considering negative stressors from human social system on the natural ecosystem, the extent and distribution of the ecological risk varied across the whole area during 2000–2015. The results show that there was almost 90.40% of this region under the ecological risk, with varying extents over the study time, e.g., Kaifeng, Shangqiu, Xuchang, and Xinyang, with a moderate deterioration in the eco-environmental quality, and Zhengzhou with a slight deterioration in the eco-environmental quality. This paper provides a valuable perspective for governments at all levels to manage

  18. Towards a publicly available, map-based regional software tool to estimate unregulated daily streamflow at ungauged rivers

    Directory of Open Access Journals (Sweden)

    S. A. Archfield

    2013-01-01

    Full Text Available Streamflow information is critical for addressing any number of hydrologic problems. Often, streamflow information is needed at locations that are ungauged and, therefore, have no observations on which to base water management decisions. Furthermore, there has been increasing need for daily streamflow time series to manage rivers for both human and ecological functions. To facilitate negotiation between human and ecological demands for water, this paper presents the first publicly available, map-based, regional software tool to estimate historical, unregulated, daily streamflow time series (streamflow not affected by human alteration such as dams or water withdrawals at any user-selected ungauged river location. The map interface allows users to locate and click on a river location, which then links to a spreadsheet-based program that computes estimates of daily streamflow for the river location selected. For a demonstration region in the northeast United States, daily streamflow was, in general, shown to be reliably estimated by the software tool. Estimating the highest and lowest streamflows that occurred in the demonstration region over the period from 1960 through 2004 also was accomplished but with more difficulty and limitations. The software tool provides a general framework that can be applied to other regions for which daily streamflow estimates are needed.

  19. Towards a publicly available, map-based regional software tool to estimate unregulated daily streamflow at ungauged rivers

    Science.gov (United States)

    Archfield, Stacey A.; Steeves, Peter A.; Guthrie, John D.; Ries, Kernell G.

    2013-01-01

    Streamflow information is critical for addressing any number of hydrologic problems. Often, streamflow information is needed at locations that are ungauged and, therefore, have no observations on which to base water management decisions. Furthermore, there has been increasing need for daily streamflow time series to manage rivers for both human and ecological functions. To facilitate negotiation between human and ecological demands for water, this paper presents the first publicly available, map-based, regional software tool to estimate historical, unregulated, daily streamflow time series (streamflow not affected by human alteration such as dams or water withdrawals) at any user-selected ungauged river location. The map interface allows users to locate and click on a river location, which then links to a spreadsheet-based program that computes estimates of daily streamflow for the river location selected. For a demonstration region in the northeast United States, daily streamflow was, in general, shown to be reliably estimated by the software tool. Estimating the highest and lowest streamflows that occurred in the demonstration region over the period from 1960 through 2004 also was accomplished but with more difficulty and limitations. The software tool provides a general framework that can be applied to other regions for which daily streamflow estimates are needed.

  20. K-Ar geology, geochemistry and geochronology from the Maria River region dikes, Parana State southeastern part, Brazil

    International Nuclear Information System (INIS)

    Silva Junior, Renato Oliveira da; Dall'Agnol, Roberto; Oliveira, Elson Paiva de

    1996-01-01

    The paper synthesizes the geological, petrographical, geochemical and geochronological data from the Maria River region dikes, situated at the southeastern part of the Para State, Brazil. It identifies five groups of dikes and determines the age of these dikes, through the Potassium-Argon (K-Ar) methodology

  1. Volatile Organic Compound (VOC) measurements in the Pearl River Delta (PRD) region, China

    Science.gov (United States)

    Liu, Ying; Shao, Min; Lu, Sihua; Chang, Chih-Chung; Wang, Jia-Lin; Chen, Gao

    2008-03-01

    We measured levels of ambient volatile organic compounds (VOCs) at seven sites in the Pearl River Delta (PRD) region of China during the Air Quality Monitoring Campaign spanning 4 October to 3 November 2004. Two of the sites, Guangzhou (GZ) and Xinken (XK), were intensive sites at which we collected multiple daily canister samples. The observations reported here provide a look at the VOC distribution, speciation, and photochemical implications in the PRD region. Alkanes constituted the largest percentage (>40%) in mixing ratios of the quantified VOCs at six sites; the exception was one major industrial site that was dominated by aromatics (about 52%). Highly elevated VOC levels occurred at GZ during two pollution episodes; however, the chemical composition of VOCs did not exhibit noticeable changes during these episodes. We calculated the OH loss rate to estimate the chemical reactivity of all VOCs. Of the anthropogenic VOCs, alkenes played a predominant role in VOC reactivity at GZ, whereas the contributions of reactive aromatics were more important at XK. Our preliminary analysis of the VOC correlations suggests that the ambient VOCs at GZ came directly from local sources (i.e., automobiles); those at XK were influenced by both local emissions and transportation of air mass from upwind areas.

  2. Emergy Synthesis and Regional Sustainability Assessment: Case Study of Pan-Pearl River Delta in China

    Directory of Open Access Journals (Sweden)

    Guomin Li

    2014-08-01

    Full Text Available In this paper, emergy analysis is used in association with the ternary diagrams and geographic information system (GIS tools to improve the evaluation of sustainability for the Pan-Pearl River Delta (PPRD region. Emergy accounting of PPRD is estimated, and various emergy-based indicators are reported. Ternary diagrams are drawn to provide a graphical representation of the emergy accounting data. Finally, the GIS tools are employed to assist in the emergy-based spatial analysis, and emergy density based on flat land area is mapped to reflect the intensity of emergy use in human activity areas. Results show the following: (1 the current development path of the PPRD region, with the value of emergy sustainability index (ESI = 0.227 significantly lower than one, is unsustainable in the long run; (2 Guangdong has the lowest ESI value (0.071, and the ESI values of Fujian, Guangxi, Hunan and Jiangxi are lower than 0.5, indicating that the economy in these provinces overly relies on non-renewable and imported resources; (3 Guizhou has a high emergy yield rate and is thus the main energy supplier in PPRD; and (4 among the nine provinces in PPRD, only Hainan has an ESI value (2.145 higher than one.

  3. 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.

  4. Geochemical evolution of groundwater in the Western Delta region of River Godavari, Andhra Pradesh, India

    Science.gov (United States)

    Nageswara Rao, P. V.; Appa Rao, S.; Subba Rao, N.

    2017-05-01

    The present study on geochemical evolution of groundwater is taken up to assess the controlling processes of water chemistry in the Western Delta region of the River Godavari (Andhra Pradesh), which is one of the major rice-producing centers in India. The study region is underlain by coarse sand with black clay (buried channels), black silty clay of recent origin (floodplain) and gray/white fine sand of modern beach sediment of marine source (coastal zone), including brown silty clay with fine sand (paleo-beach ridges). Groundwater is mostly brackish and very hard. It is characterized by Na+ > Mg2+ > Ca2+:HCO3 - > Cl- > SO4 2- > NO3 -, Na+ > Mg2+ > Ca2+:Cl- > HCO3 - > SO4 2-, and Mg2+ > Na+ > Ca2+ > or Cl- > or > SO4 2- facies. The ionic relations (Ca2+ + Mg2+:HCO3 -, Ca2+ + Mg2+:SO4 2- + HCO3 -, Na+ + K+:TC, Na+ + K+:Cl- + SO4 2-, HCO3 -:TC, HCO3 -:Ca2+ + Mg2+, Na+:Cl- and Na+:Ca2+) indicate that the rock weathering, mineral dissolution, evaporation and ion exchange are the processes to control the aquifer chemistry. Anthropogenic and marine sources are also the supplementary factors for brackish water quality. These observations are further supported by Gibbs mechanisms that control the water chemistry. Thus, the study suggests that the initial quality of groundwater of geogenic origin has been subsequently modified by the influences of anthropogenic and marine sources.

  5. DDT concentration in fish from the Tapajós River in the Amazon region, Brazil.

    Science.gov (United States)

    Mendes, Rosivaldo de Alcântara; Lopes, Anna Sylmara da Costa; de Souza, Larissa Costa; Lima, Marcelo de Oliveira; Santos, Lourivaldo da Silva

    2016-06-01

    DDT and metabolites were measured in six species of fish collected from the Tapajós River in the village of Barreiras, near the town of Itaituba in the Brazilian Amazon region. The selected fish were the most consumed and economically important to the local people. DDT was used frequently in this region for malaria control. Fish samples were analyzed after extraction by microwave-assisted extraction in hexane/acetone (8:2, v/v) by gas chromatography with electron capture detector. Residues of op'-DDT and pp'-DDT and metabolites were detected, including pp'-DDE, pp'-DDD, op'-DDT, and op'-DDE, in 98% of the samples, with a greater abundance of pp'-DDT. Total DDT levels were 7.1-249.5 ng g(-1) wet weight (w.w). The DDE/DDT ratio was low, indicating recent exposure to DDT. The study area that may be related to generated waste used in public health campaigns to combat mosquitos (Anopheles spp.), still present in the Amazon environment, that transmit malaria. DDT levels and metabolites found in fish species do not present risks to human health because they are below acceptable limits for consumption. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Expected changes in future temperature extremes and their elevation dependency over the Yellow River source region

    Directory of Open Access Journals (Sweden)

    Y. Hu

    2013-07-01

    Full Text Available Using the Statistical DownScaling Model (SDSM and the outputs from two global climate models, we investigate possible changes in mean and extreme temperature indices and their elevation dependency over the Yellow River source region for the two future periods 2046–2065 and 2081–2100 under the IPCC SRES A2, A1B and B1 emission scenarios. Changes in interannual variability of mean and extreme temperature indices are also analyzed. The validation results show that SDSM performs better in reproducing the maximum temperature-related indices than the minimum temperature-related indices. The projections show that by the middle and end of the 21st century all parts of the study region may experience increases in both mean and extreme temperature in all seasons, along with an increase in the frequency of hot days and warm nights and with a decrease in frost days. By the end of the 21st century, interannual variability increases in all seasons for the frequency of hot days and warm nights and in spring for frost days while it decreases for frost days in summer. Autumn demonstrates pronounced elevation-dependent changes in which around six out of eight indices show significant increasing changes with elevation.

  7. Simulation of the Impacts of Urbanization on Winter Meteorological Fields over the Pearl River Delta Region

    Directory of Open Access Journals (Sweden)

    Naixing Luo

    2017-01-01

    Full Text Available The influences of urbanization on weather in Guangdong Province, China, were studied using the Weather Research and Forecasting model from 31 December 2009 through 3 January 2010. Model outputs were compared with extensive monitoring of meteorological data to examine the simulation ability. Model results between tests (with and without land-use change show that the urbanization had major effects on meteorological fields across nearly the entire Pearl River Delta region and particularly in urban areas. Studied fields (wind speed, temperature, precipitation, and sensible and latent heat fluxes were affected by the urbanization of the PRD region. The major influences occurred in urban areas, where wind speeds decreased greatly, while the daytime surface upward sensible heat flux clearly increased. Unlike the sensible heat flux, the latent heat flux had a nonmonotonic increase or decrease. As a consequence of the two heat fluxes, 2-m temperature varied with location and time. Change of precipitation was complex. The main rain band became more concentrated, while precipitation decreased upwind of the urban area and increased downwind.

  8. Regional Frequency Analysis of Extreme Dry Spells during Rainy Season in the Wei River Basin, China

    Directory of Open Access Journals (Sweden)

    Dunxian She

    2016-01-01

    Full Text Available Our research analyzes the regional changes of extreme dry spell, represented by the annual maximum dry spell length (noted as AMDSL during the rainy season in the Wei River Basin (WRB of China for 1960–2014 using the L-moments method. The mean AMDSL values increase from the west to the east of the WRB, suggesting a high dry risk in the east compared to the west in the WRB. To investigate the regional frequency more reasonably, the WRB is clustered into four homogenous subregions via the K-means method and some subjective adjustments. The goodness-of-fit test shows that the GEV, PE3, and GLO distribution can be accepted as the “best-fit” model for subregions 1 and 4, subregion 2, and subregion 3, respectively. The quantiles of AMDSL under various return levels figure out a similar spatial distribution with mean AMDSL. We also find that the dry risk in subregion 2 and subregion 4 might be higher than that in subregion 1. The relationship between ENSO events and extreme dry spell events in the rainy season with cross wavelet analysis method proves that ENSO events play a critical role in triggering extreme dry events during rainy season in the WRB.

  9. Volatile Organic Compound (VOC measurements in the Pearl River Delta (PRD region, China

    Directory of Open Access Journals (Sweden)

    Chih-chung Chang

    2008-03-01

    Full Text Available We measured levels of ambient volatile organic compounds (VOCs at seven sites in the Pearl River Delta (PRD region of China during the Air Quality Monitoring Campaign spanning 4 October to 3 November 2004. Two of the sites, Guangzhou (GZ and Xinken (XK, were intensive sites at which we collected multiple daily canister samples. The observations reported here provide a look at the VOC distribution, speciation, and photochemical implications in the PRD region. Alkanes constituted the largest percentage (>40% in mixing ratios of the quantified VOCs at six sites; the exception was one major industrial site that was dominated by aromatics (about 52%. Highly elevated VOC levels occurred at GZ during two pollution episodes; however, the chemical composition of VOCs did not exhibit noticeable changes during these episodes. We calculated the OH loss rate to estimate the chemical reactivity of all VOCs. Of the anthropogenic VOCs, alkenes played a predominant role in VOC reactivity at GZ, whereas the contributions of reactive aromatics were more important at XK. Our preliminary analysis of the VOC correlations suggests that the ambient VOCs at GZ came directly from local sources (i.e., automobiles; those at XK were influenced by both local emissions and transportation of air mass from upwind areas.

  10. Regional tree growth and inferred summer climate in the Winnipeg River basin, Canada, since AD 1783

    Science.gov (United States)

    St. George, Scott; Meko, David M.; Evans, Michael N.

    2008-09-01

    A network of 54 ring-width chronologies is used to estimate changes in summer climate within the Winnipeg River basin, Canada, since AD 1783. The basin drains parts of northwestern Ontario, northern Minnesota and southeastern Manitoba, and is a key area for hydroelectric power production. Most chronologies were developed from Pinus resinosa and P. strobus, with a limited number of Thuja occidentalis, Picea glauca and Pinus banksiana. The dominant pattern of regional tree growth can be recovered using only the nine longest chronologies, and is not affected by the method used to remove variability related to age or stand dynamics from individual trees. Tree growth is significantly, but weakly, correlated with both temperature (negatively) and precipitation (positively) during summer. Simulated ring-width chronologies produced by a process model of tree-ring growth exhibit similar relationships with summer climate. High and low growth across the region is associated with cool/wet and warm/dry summers, respectively; this relationship is supported by comparisons with archival records from early 19th century fur-trading posts. The tree-ring record indicates that summer droughts were more persistent in the 19th and late 18th century, but there is no evidence that drought was more extreme prior to the onset of direct monitoring.

  11. Stream fish colonization but not persistence varies regionally across a large North American river basin

    Science.gov (United States)

    Wheeler, Kit; Wengerd, Seth J.; Walsh, Stephen J.; Martin, Zachary P.; Jelks, Howard L.; Freeman, Mary C.

    2018-01-01

    Many species have distributions that span distinctly different physiographic regions, and effective conservation of such taxa will require a full accounting of all factors that potentially influence populations. Ecologists recognize effects of physiographic differences in topography, geology and climate on local habitat configurations, and thus the relevance of landscape heterogeneity to species distributions and abundances. However, research is lacking that examines how physiography affects the processes underlying metapopulation dynamics. We used data describing occupancy dynamics of stream fishes to evaluate evidence that physiography influences rates at which individual taxa persist in or colonize stream reaches under different flow conditions. Using periodic survey data from a stream fish assemblage in a large river basin that encompasses multiple physiographic regions, we fit multi-species dynamic occupancy models. Our modeling results suggested that stream fish colonization but not persistence was strongly governed by physiography, with estimated colonization rates considerably higher in Coastal Plain streams than in Piedmont and Blue Ridge systems. Like colonization, persistence was positively related to an index of stream flow magnitude, but the relationship between flow and persistence did not depend on physiography. Understanding the relative importance of colonization and persistence, and how one or both processes may change across the landscape, is critical information for the conservation of broadly distributed taxa, and conservation strategies explicitly accounting for spatial variation in these processes are likely to be more successful for such taxa.

  12. Heavy metal contamination in some mining communities within the Jimi River basin in Ashanti Region, Ghana

    International Nuclear Information System (INIS)

    Akabzaa, T.M.; Banoeng-Yakubu, B.; Seyire, J.S.

    2005-01-01

    The study assesses heavy metals contamination of some communities along the Jim River Basin in the Ashanti Region. The Jim River Basin is within the mining concession of Ashanti Goldfields Company (AGC) Limited, now Anglogold Ashanti. The selected communities receive drainage and effluent from mining, processing and waste containment facilities of AGC and from the activities of illegal small scale miners (galamseys) in the area. Representative samples of water from streams, boreholes, hand-dug wells, stream and over bank sediments, and fruits were analyzed for Mn, Cu, Zn, Ni, Pb and Cd using the Unicam 969 Atomic Absorption Spectrometer (AAS). Fe was determined by ion chromatography, As by an ARL 341 hydride-generator and Hg by cold vapour Atomic Fluorescence Spectrometry. Protracted periods of underground mining, recent extensive surface mining and intensified illegal mining activities were identified as major sources of augmented levels of heavy metals in water, sediment and fruit samples. Sediments and fruits exhibit higher concentration of determined metals than water. Cu, Cd, Zn, and Ni, are generally low in water samples, while Fe, As and Mn are generally high, particularly in stream water and ranged from < 0.002 to 17.100mg/l, 0.001 to 6.318mg/l and <0.001 to 2.584mg/l respectively. Metal concentrations were highest in sediments. Fe values in sediments ranged from 2210-50180 mg/kg and averaged 28270mg/kg, Hg between 0.26 to 3.02 mg/kg and averaged 1.21mg/kg while arsenic ranged between 0.24-to 7591.58mg/kg and averaged 1746.51mg/kg. Heavy metals in fruit samples were considered indicative of their bioavailability. Some fruits showed extremely high concentrations Hg, Zn and As. High heavy metal concentrations are generally coincident with areas of past and/ or of active mining and processing activities. (author)

  13. Modeling Regional Soil Water Balance in Farmland of the Middle Reaches of Heihe River Basin

    Directory of Open Access Journals (Sweden)

    Jiang Li

    2017-11-01

    Full Text Available Quantifying components of soil water balance in farmland of the middle reaches of Heihe River Basin is essential for efficiently scheduling and allocating limited water resources for irrigation in this arid region. A soil water balance model based on empirical assumptions in the vadose zone of farmland was developed and simulation results were compared/validated with results by the numerical model HYDRUS-1D. Results showed a good coherence between the simulated results of the water balance models and the HYDRUS-1D model in soil water storage, evapotranspiration, deep percolation and groundwater recharge, which indicated that the water balance model was suitable for simulating soil water movement in the study area. Considering the spatial distribution of cropping patterns, groundwater depth and agricultural management, ArcGIS was applied for the pre-/post-processing of the water balance model to quantify the spatial distribution of components of soil water balance in the major cropland in middle reaches of Heihe River Basin. Then, distributions of components of soil water balance in the major cropland under different water-saving irrigation practices during the growing season were predicted and discussed. Simulation results demonstrated that evapotranspiration of the main crops would be more prominently influenced by irrigation quota under deep groundwater depth than that under shallow groundwater depth. Groundwater recharge would increase with the increase of irrigation quota and decrease with the increase of groundwater depth. In general, when groundwater depth reached 3 m, groundwater recharge from root zone was negligible for spring wheat. While when it reached 6 m, groundwater recharge was negligible for maize. Water-saving irrigation practices would help to reduce groundwater recharge with a slight decrease of crop water consumption.

  14. An Experience of Statistical Method Application in Forest Survey at Angara River Region in 1932

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    L. N. Vashchuk

    2014-10-01

    Full Text Available Report of the Angara forest economic expedition of forest economic survey in 1932 on the left bank of the Angara River has been found. The survey covered a part of Krasnoyarsk Territory and Irkutsk region, a total area of 18641.8 thousand ha. The report describes technology of forest inventory and achievements that have not previously been published. The survey was conducted by statistical method, which consisted of a sample by a continuous forest inventory enumeration of trees on sample plots (SP, arranged in an array on a particular system, followed by mathematical-statistical recalculation of the sample results to the entire survey. To do this, strip finders (sights were cut in the latitudinal direction at a distance from one another at 16 km. On the hacked sights, by every 2 km, 0.1 ha (10 × 100 m SP were established. In total 32 forest inventory sights were hacked, with total length of 9931 km, which incorporated 4817 SP. The accuracy of forest resources’ inventory characteristics determining also was investigated using smaller sample plots. For this purpose, each of the SP were cut to smaller area of 0.01 ha (10 × 10 m, where independent continuous enumeration of trees was conducted, andsample trees were cut, measured and bucked to the assortments, to explore the tree stand assortment structure. At each «sample cutting area» all the trees were felled out from 44 cm and above DBH. At half of the sample plot with 5 × 10 m size, located in the eastern end, all the trees were felled out and measured from 24 cm and above DBH. Every four «sample cutting area» in the fifth, all the trees with 12 cm and above DBH were cut down and measured. According to the results of the work, a detailed description of forest resources in the whole Angara river basin, and across 17 forest exploitation areas was completed.

  15. Lower Colorado River Geographic Response Plan Restricted Web Mapping Service, Region 9, 2012, US EPA Region 9

    Data.gov (United States)

    U.S. Environmental Protection Agency — This map service is comprised of data related to Geographic Response Plans (GRPs) for the Lower Colorado River. Data layers were contributed by various stakeholders...

  16. Evaluating the effect of sample type on American alligator (Alligator mississippiensis) analyte values in a point-of-care blood analyser.

    Science.gov (United States)

    Hamilton, Matthew T; Finger, John W; Winzeler, Megan E; Tuberville, Tracey D

    2016-01-01

    The assessment of wildlife health has been enhanced by the ability of point-of-care (POC) blood analysers to provide biochemical analyses of non-domesticated animals in the field. However, environmental limitations (e.g. temperature, atmospheric humidity and rain) and lack of reference values may inhibit researchers from using such a device with certain wildlife species. Evaluating the use of alternative sample types, such as plasma, in a POC device may afford researchers the opportunity to delay sample analysis and the ability to use banked samples. In this study, we examined fresh whole blood, fresh plasma and frozen plasma (sample type) pH, partial pressure of carbon dioxide (PCO2), bicarbonate (HCO3 (-)), total carbon dioxide (TCO2), base excess (BE), partial pressure of oxygen (PO2), oxygen saturation (sO2) and lactate concentrations in 23 juvenile American alligators (Alligator mississippiensis) using an i-STAT CG4+ cartridge. Our results indicate that sample type had no effect on lactate concentration values (F 2,65 = 0.37, P = 0.963), suggesting that the i-STAT analyser can be used reliably to quantify lactate concentrations in fresh and frozen plasma samples. In contrast, the other seven blood parameters measured by the CG4+ cartridge were significantly affected by sample type. Lastly, we were able to collect blood samples from all alligators within 2 min of capture to establish preliminary reference ranges for juvenile alligators based on values obtained using fresh whole blood.

  17. Regional severe particle pollution and its association with synoptic weather patterns in the Yangtze River Delta region, China

    Science.gov (United States)

    Shu, Lei; Xie, Min; Gao, Da; Wang, Tijian; Fang, Dexian; Liu, Qian; Huang, Anning; Peng, Liwen

    2017-11-01

    Regional air pollution is significantly associated with dominant weather systems. In this study, the relationship between the particle pollution over the Yangtze River Delta (YRD) region and weather patterns is investigated. First, the pollution characteristics of particles in the YRD are studied using in situ monitoring data (PM2.5 and PM10) in 16 cities and Terra/MODIS AOD (aerosol optical depth) products collected from December 2013 to November 2014. The results show that the regional mean value of AOD is high in the YRD, with an annual mean value of 0.71±0.57. The annual mean particle concentrations in the cities of Jiangsu Province all exceed the national air quality standard. The pollution level is higher in inland areas, and the highest concentrations of PM2.5 and PM10 are 79 and 130 µg m-3, respectively, in Nanjing. The PM2.5 : PM10 ratios are typically high, thus indicating that PM2.5 is the overwhelmingly dominant particle pollutant in the YRD. The wintertime peak of particle concentrations is tightly linked to the increased emissions during the heating season as well as adverse meteorological conditions. Second, based on NCEP (National Center for Environmental Prediction) reanalysis data, synoptic weather classification is conducted and five typical synoptic patterns are objectively identified. Finally, the synthetic analysis of meteorological fields and backward trajectories are applied to further clarify how these patterns impact particle concentrations. It is demonstrated that air pollution is more or less influenced by high-pressure systems. The relative position of the YRD to the anti-cyclonic circulation exerts significant effects on the air quality of the YRD. The YRD is largely influenced by polluted air masses from the northern and the southern inland areas when it is located at the rear of the East Asian major trough. The significant downward motion of air masses results in stable weather conditions, thereby hindering the diffusion of air

  18. Carbon dioxide transport in alligator blood and its erythrocyte permeability to anions and water

    DEFF Research Database (Denmark)

    Jensen, F B; Wang, T; Jones, D R

    1998-01-01

    Deoxygenation of alligator red blood cells (RBCs) caused binding of two HCO3- equivalents per hemoglobin (Hb) tetramer at physiological pH. At lowered pH, some HCO3- binding also occurred to oxygenated Hb. The erythrocytic total CO2 content was large, and Hb-bound HCO3-, free HCO3-, and carbamate...

  19. Differential protein expression in alligator leukocytes in response to bacterial lipopolysaccharide injection.

    Science.gov (United States)

    Merchant, Mark; Kinney, Clint; Sanders, Paige

    2009-12-01

    Blood was collected from three juvenile alligators (Alligator mississippiensis) before, and again 24h after, injection with bacterial lipopolysaccharide (LPS). The leukocytes were collected from both samples, and the proteins were extracted. Each group of proteins was labeled with a different fluorescent dye and the differences in protein expression were analyzed by two dimensional differential in-gel expressions (2D-DIGE). The proteins which appeared to be increased or decreased by treatment with LPS were selected and analyzed by MALDI-TOF to determine mass and LC-MS/MS to acquire the partial protein sequences. The peptide sequences were compared to the NCBI protein sequence database to determine homology with other sequences from other species. Several proteins of interest appeared to be increased upon LPS stimulation. Proteins with homology to human transgelin-2, fish glucose-6-phosphate dehydrogenase, amphibian α-enolase, alligator lactate dehydrogenase, fish ubiquitin-activating enzyme, and fungal β-tubulin were also increased after LPS injection. Proteins with homology to fish vimentin 4, murine heterogeneous nuclear ribonucleoprotein A3, and avian calreticulin were found to be decreased in response to LPS. In addition, five proteins, four of which were up-regulated (827, 560, 512, and 650%) and one that exhibited repressed expression (307%), did not show homology to any protein in the database, and thus may represent newly discovered proteins. We are using this biochemical approach to isolate and characterize alligator proteins with potential relevant immune function.

  20. Hydrochemical and isotopic studies in two neighboring river basins in semiarid regions of Minas Gerais

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Vinícius G.; Moreira, Rubens M.; Carvalho, Carlos A., E-mail: vinicius.ferreira@cdtn.br, E-mail: rubens@cdtn.br, E-mail: cacf@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Serviço de Meio Ambiente

    2017-07-01

    Groundwater is the largest reservoir of fresh water on Earth and the depletion of aquifer systems is a reality, both in semi-arid and humid regions. The hydrology of watersheds is a field of study that is concerned with the movement of waters from the rains and its physical-chemical changes. Groundwater resources in these regions are a sensitive issue, requiring careful management to avoid quality degradation. The present study focuses the groundwater system at the interface of the Pandeiros and Peruaçu river basins in the northwest region of Minas Gerais State. The methods used were the evaluations of the hydrochemistry, as well as isotopic, and physicochemical parameters, allied to geological studies to investigate surface and groundwater, their possible interactions and spatial distribution. The hydrochemical results correlated with the physicochemical measurements show water contrasts in the study area, which is geologically composed from bottom to top by gneisses and granites (Januaria Complex), limestone and siltstones (Bambuí Group), sandstones and eluvial sediments (Urucuia Group), eluvio-coluvial cover and alluvial deposits. It has been observed that waters in the context of sandstones and siliceous sediments are sodium bicarbonate waters, slightly acidic pH and low in TDS, whereas waters in pedological / geologic context of limestones are calcium bicarbonate waters exhibiting basic pH and high TDS. The deuterium (D) and oxygen-18 signatures of the groundwater are compared to the global meteoric water line (GMWL). The average values of the isotopes in the study area are slightly variable, indicating that the isotopic signatures are related to rainfall precipitation. It has been possible to suggest an evaporation line pattern starting from the position of springs, passing though streams and finally ending in the lagoon. The local evaporation line can be represented by the equation δD = 5,8 δ{sup 18}O - 2,4. (author)

  1. Regionalizing Aquatic Ecosystems Based on the River Subbasin Taxonomy Concept and Spatial Clustering Techniques

    Directory of Open Access Journals (Sweden)

    Jiahu Zhao

    2011-11-01

    Full Text Available Aquatic ecoregions were increasingly used as spatial units for aquatic ecosystem management at the watershed scale. In this paper, the principle of including land area, comprehensiveness and dominance, conjugation and hierarchy were selected as regionalizing principles. Elevation and drainage density were selected as the regionalizing indicators for the delineation of level I aquatic ecoregions, and percent of construction land area, percent of cultivated land area, soil type and slope for the level II. Under the support of GIS technology, the spatial distribution maps of the two indicators for level I and the four indicators for level II aquatic ecoregion delineation were generated from the raster data based on the 1,107 subwatersheds. River subbasin taxonomy concept, two-step spatial clustering analysis approach and manual-assisted method were used to regionalize aquatic ecosystems in the Taihu Lake watershed. Then the Taihu Lake watershed was divided into two level I aquatic ecoregions, including Ecoregion I1 and Ecoregion I2, and five level II aquatic subecoregions, including Subecoregion II11, Subecoregion II12, Subecoregion II21, Subecoregion II22 and Subecoregion II23. Moreover, the characteristics of the two level I aquatic ecoregions and five level II aquatic subecoregions in the Taihu Lake watershed were summarized, showing that there were significant differences in topography, socio-economic development, water quality and aquatic ecology, etc. The results of quantitative comparison of aquatic life also indicated that the dominant species of fish, benthic density, biomass, dominant species, Shannon-Wiener diversity index, Margalef species richness index, Pielou evenness index and ecological dominance showed great spatial variability between the two level I aquatic ecoregions and five level II aquatic subecoregions. It reflected the spatial heterogeneities and the uneven natures of aquatic ecosystems in the Taihu Lake watershed.

  2. Temporal fluctuation of multidrug resistant salmonella typhi haplotypes in the mekong river delta region of Vietnam.

    Directory of Open Access Journals (Sweden)

    Kathryn E Holt

    2011-01-01

    Full Text Available typhoid fever remains a public health problem in Vietnam, with a significant burden in the Mekong River delta region. Typhoid fever is caused by the bacterial pathogen Salmonella enterica serovar Typhi (S. Typhi, which is frequently multidrug resistant with reduced susceptibility to fluoroquinolone-based drugs, the first choice for the treatment of typhoid fever. We used a GoldenGate (Illumina assay to type 1,500 single nucleotide polymorphisms (SNPs and analyse the genetic variation of S. Typhi isolated from 267 typhoid fever patients in the Mekong delta region participating in a randomized trial conducted between 2004 and 2005.the population of S. Typhi circulating during the study was highly clonal, with 91% of isolates belonging to a single clonal complex of the S. Typhi H58 haplogroup. The patterns of disease were consistent with the presence of an endemic haplotype H58-C and a localised outbreak of S. Typhi haplotype H58-E2 in 2004. H58-E2-associated typhoid fever cases exhibited evidence of significant geo-spatial clustering along the Sông H u branch of the Mekong River. Multidrug resistance was common in the established clone H58-C but not in the outbreak clone H58-E2, however all H58 S. Typhi were nalidixic acid resistant and carried a Ser83Phe amino acid substitution in the gyrA gene.the H58 haplogroup dominates S. Typhi populations in other endemic areas, but the population described here was more homogeneous than previously examined populations, and the dominant clonal complex (H58-C, -E1, -E2 observed in this study has not been detected outside Vietnam. IncHI1 plasmid-bearing S. Typhi H58-C was endemic during the study period whilst H58-E2, which rarely carried the plasmid, was only transient, suggesting a selective advantage for the plasmid. These data add insight into the outbreak dynamics and local molecular epidemiology of S. Typhi in southern Vietnam.

  3. Radionuclide content in the Upper Vistula River sediments in a coal mining region in Poland (east-central Europe)

    International Nuclear Information System (INIS)

    Jasinska, M.; Mietelski, J.W.; Pociask-Karteczka, J.

    1998-01-01

    Hard coal mining activity is one of the Technologically Enhanced Natural Radiation sources introduced more than a hundred years ago in the southern part of Poland. This study of radionuclides (K-40, Ra-226, Ra-228) in river sediments showed the principal factors determining the specific activity of radionuclides are distance from mines and sorption by clay particles in river sediments. The K-40 specific activity varies between 185 and 595 Bq/kg. The highest Ra-228 and Ra-226 specific activities, 280-610 and 205-415 Bq/kg, respectively, were detected in sediments of the Vistula in the vicinity of Silesia region. 7 refs., 1 fig., 3 tabs

  4. Early mixed farming of millet and rice 7800 years ago in the Middle Yellow River region, China.

    Directory of Open Access Journals (Sweden)

    Jianping Zhang

    Full Text Available The Peiligang Culture (9000-7000 cal. yr BP in the Middle Yellow River region, North China, has long been considered representative of millet farming. It is still unclear, however, if broomcorn millet or foxtail millet was the first species domesticated during the Peiligang Culture. Furthermore, it is also unknown whether millet was cultivated singly or together with rice at the same period. In this study, phytolith analysis of samples from the Tanghu archaeological site reveals early crop information in the Middle Yellow River region, China. Our results show that broomcorn millet was the early dry farming species in the Peiligang Culture at 7800 cal. yr BP, while rice cultivation took place from 7800 to 4500 cal. yr BP. Our data provide new evidence of broomcorn millet and rice mixed farming at 7800 cal. yr BP in the Middle Yellow River region, which has implications for understanding the domestication process of the two crops, and the formation and continuance of the Ancient Yellow River Civilization.

  5. Flood Zoning Simulation by HEC-RAS Model (Case Study: Johor River-Kota Tinggi Region)

    OpenAIRE

    ShahiriParsa, Ahmad; Heydari, Mohammad; Sadeghian, Mohammad Sadegh; Moharrampour, Mahdi

    2015-01-01

    Flooding of rivers has caused many human and financial losses. Hence, studies and research on the nature of the river is inevitable.However, the behavior of rivers hasmany complexities and in this respect, computer models are efficient tools in order to study and simulate the behavior of rivers with the least possible cost. In this paper, one-dimensional model HEC-RAS was used to simulate the flood zoning in the Kota Tinggi district in Johor state. Implementation processes of the zoning on ca...

  6. Geologic map of the upper Arkansas River valley region, north-central Colorado

    Science.gov (United States)

    Kellogg, Karl S.; Shroba, Ralph R.; Ruleman, Chester A.; Bohannon, Robert G.; McIntosh, William C.; Premo, Wayne R.; Cosca, Michael A.; Moscati, Richard J.; Brandt, Theodore R.

    2017-11-17

    This 1:50,000-scale U.S. Geological Survey geologic map represents a compilation of the most recent geologic studies of the upper Arkansas River valley between Leadville and Salida, Colorado. The valley is structurally controlled by an extensional fault system that forms part of the prominent northern Rio Grande rift, an intra-continental region of crustal extension. This report also incorporates new detailed geologic mapping of previously poorly understood areas within the map area and reinterprets previously studied areas. The mapped region extends into the Proterozoic metamorphic and intrusive rocks in the Sawatch Range west of the valley and the Mosquito Range to the east. Paleozoic rocks are preserved along the crest of the Mosquito Range, but most of them have been eroded from the Sawatch Range. Numerous new isotopic ages better constrain the timing of both Proterozoic intrusive events, Late Cretaceous to early Tertiary intrusive events, and Eocene and Miocene volcanic episodes, including widespread ignimbrite eruptions. The uranium-lead ages document extensive about 1,440-million years (Ma) granitic plutonism mostly north of Buena Vista that produced batholiths that intruded an older suite of about 1,760-Ma metamorphic rocks and about 1,700-Ma plutonic rocks. As a result of extension during the Neogene and possibly latest Paleogene, the graben underlying the valley is filled with thick basin-fill deposits (Dry Union Formation and older sediments), which occupy two sub-basins separated by a bedrock high near the town of Granite. The Dry Union Formation has undergone deep erosion since the late Miocene or early Pliocene. During the Pleistocene, ongoing steam incision by the Arkansas River and its major tributaries has been interrupted by periodic aggradation. From Leadville south to Salida as many as seven mapped alluvial depositional units, which range in age from early to late Pleistocene, record periodic aggradational events along these streams that are

  7. Geochronology of granitoids and gnaisses from the Rio Maria, Mata Geral farm and Itacaiunas river regions, southern Para, Brazil

    International Nuclear Information System (INIS)

    Montalvao, R.M.G. de; Tassinari, C.C.G.; Bezerra, P.E.L.; Prado, P.

    1984-01-01

    Granitoids and gneisses occurring at Rio Maria, Mata Geral farm and Itacaiunas river regions, southern Para, underwent radiometric age determinations by Rb/Sr method using conventional isochrons. Results obtained from the Rio Maria and Mata Geral farm regions allowed te establishment of a reference 2,600 my Rb/Sr isochron with an initial Sr 87 /Sr 86 ratio of 0.7009. This result resembles the one obtained for granitoids and gneisses hosting rocks of the Serra do Inaja greenstone belt, located some what south of this area, which yielded, in Rb/Sr isochron, a radiometric age of 2,696 + - 79 my with an initial Sr 87 /Sr 86 ratio of 0.701. Results obtained from the Itacaiunas river region allowed for the establishment of a Rb/Sr referential isochron of 2,480 + - 40 my wth an initial Sr 87 /.Sr 86 ratio of 0.7072. Due to low initial ratios, it is suggested that the rocks from the Rio Maria, Mata Geral farm and Serra do Inaja regions formed from Mafic crust or superior mantle reworking, while those from the Itacaiunas river region, due to a high initial ratio, result from reworking at high crustal levels. (Author) [pt

  8. Hydrogeological modelling of the eastern region of Areco river locally detailed on Atucha I and II nuclear power plants area

    International Nuclear Information System (INIS)

    Grattone, Natalia I.; Fuentes, Nestor O.

    2009-01-01

    Water flow behaviour of Pampeano aquifer was modeled using Visual Mod-flow software Package 2.8.1 with the assumption of a free aquifer, within the region of the Areco river and extending to the rivers of 'Canada Honda' and 'de la Cruz'. Steady state regime was simulated and grid refinement allows obtaining locally detailed calculation in the area of Atucha I and II Nuclear power plants, in order to compute unsteady situations as the consequence of water flow variations from and to the aquifer, enabling the model to study the movement of possible contaminant particles in the hydrogeologic system. In this work the effects of rivers action, the recharge conditions and the flow lines are analyzed, taking always into account the range of reliability of obtained results, considering the incidence of uncertainties introduced by data input system, the estimates and interpolation of parameters used. (author)

  9. Comparison of sediment pollution in the rivers of the Hungarian Upper Tisza Region using non-destructive analytical techniques

    International Nuclear Information System (INIS)

    Osan, Janos; Toeroek, Szabina; Alfoeldy, Balint; Alsecz, Anita; Falkenberg, Gerald; Baik, Soo Yeun; Van Grieken, Rene

    2007-01-01

    The rivers in the Hungarian Upper Tisza Region are frequently polluted mainly due to mining activities in the catchment area. At the beginning of 2000, two major mining accidents occurred in the Romanian part of the catchment area due to the failure of a tailings dam releasing huge amounts of cyanide and heavy metals to the rivers. Surface sediment as well as water samples were collected at six sites in the years 2000-2003, from the northeast-Hungarian section of the Tisza, Szamos and Tur rivers. The sediment pollution of the rivers was compared based on measurements of bulk material and selected single particles, in order to relate the observed compositions and chemical states of metals to the possible sources and weathering of pollution. Non-destructive X-ray analytical methods were applied in order to obtain different kinds of information from the same samples or particles. In order to identify the pollution sources, their magnitude and fate, complementary analyses were carried out. Heterogeneous particulate samples were analyzed from a large geographical territory and a 4-year time period. Individual particles were analyzed only from the 'hot' samples that showed elevated concentrations of heavy metals. Particles that were classified as anthropogenic were finally analyzed to identify trace concentrations and chemical states of heavy metals. Although the Tisza river was affected by water pollution due to the two major mining accidents at the beginning of 2000, the concentration of heavy metals in sediments decreased to the mineral background level 1 year after the pollution event. In the tributaries Szamos and Tur, however, no significant decrease of the heavy metal concentrations was observed in the recent years, indicating a continuous pollution. Among the water suspended particles collected from river Tur, fibers of unknown origin were observed by electron microscopy; these particles were aluminosilicates enriched in Zn and Mn. Cd was also concentrated in

  10. Hydrologic cycle and dynamics of aquatic macrophytes in two intermittent rivers of the semi-arid region of Brazil

    Directory of Open Access Journals (Sweden)

    F. Pedro

    Full Text Available The dynamics of aquatic macrophytes in intermittent rivers is generally related to the characteristics of the resistance and resilience of plants to hydrologic disturbances of flood and drought. In the semi-arid region of Brazil, intermittent rivers and streams are affected by disturbances with variable intensity, frequency, and duration throughout their hydrologic cycles. The aim of the present study is to determine the occurrence and variation of biomass of aquatic macrophyte species in two intermittent rivers of distinct hydrologic regimes. Their dynamics were determined with respect to resistance and resilience responses of macrophytes to flood and drought events by estimating the variation of biomass and productivity throughout two hydrologic cycles. Twenty-one visits were undertaken in the rewetting, drying, and drought phases in a permanent puddle in the Avelós stream and two temporary puddles in the Taperoá river, state of Paraíba, Northeast Brazil. The sampling was carried out by using the square method. Floods of different magnitudes occurred during the present study in the river and in the stream. The results showed that floods and droughts are determining factors in the occurrence of macrophytes and in the structure of their aquatic communities. The species richness of the aquatic macrophyte communities was lower in the puddles of the river and stream subject to flood events, when compared to areas where the run-off water is retained. At the beginning of the recolonization process, the intensity of the floods was decisive in the productivity and biomass of the aquatic macrophytes in the Taperoá river and the Avelós stream. In intermediate levels of disturbance, the largest values of productivity and biomass and the shortest time for starting the recolonization process occurred.

  11. On the Relationship between Holocene Geomorphic Evolution of Rivers and Prehistoric Settlements Distribution in the Songshan Mountain Region of China

    Directory of Open Access Journals (Sweden)

    Peng Lu

    2017-01-01

    Full Text Available This paper deals with the study of Holocene geomorphic evolution of rivers around Songshan Mountain in relation to human frequentation in Prehistoric periods. The investigations were performed by means of an integration of GIS data processing; field surveys and particle size analysis. In 8000–3000 aBP; in the Songshan Mountain Region, large-scale river sedimentation occurred. This increased the elevation of river beds that were higher than today. After 3000 aBP; the upper reaches of the rivers experienced a down cut; while the lower reaches experienced continuing sedimentation. The data on the elevation of prehistoric settlements above the river levels were obtained from Digital Elevation Models (DEMs. These data were corrected according to the evolutionary features of fluvial landforms in order to obtain synchronous elevations above river levels of prehistoric settlements. The relationship between sediment distribution and the Holocene geomorphic evolution was investigated through the statistical analysis of the elevation above the river levels. Outputs from our analyses enabled us to differentiate three evolutionary stages. During the first one, related to Peiligang culture (9000–7500 aBP, populations mainly settled on both hilly relief and high plateaus depending on their agriculture production modes. During the second stage, from Yangshao (7500–5000 aBP to the Longshan period (5000–4000 aBP, settlements were mainly distributed on mountainous areas and hilly lands to avoid flooding and to develop agriculture. Finally, during the Xiashang culture (4000–3000 aBP, a large number of settlements migrated to the plain area to facilitate trade of goods and cultural exchanges.

  12. Identification of fish nursery areas in a free tributary of an impoundment region, upper Uruguay River, Brazil

    Directory of Open Access Journals (Sweden)

    Patrícia Alves da Silva

    Full Text Available This study aims to determine the importance of different environments of the Ligeiro River (upper Uruguay River, Brazil in fish reproduction. For this purpose, three environments (sampling sites were selected: rapids, a pool, and the mouth of the Ligeiro River. Ichthyoplankton, zooplankton, and benthos were sampled six times per month from September, 2006 to March, 2007. Zooplankton and ichthyoplankton samples were collected early in the evening with plankton nets (64 µm and 500 µm, respectively. Benthos samples were also collected early in the evening with a Van Veen dredge. Local abiotic variables (temperature, dissolved oxygen, pH, electrical conductivity, water speed, alkalinity, water hardness, and water transparency were measured simultaneously with the biotic data sampling and were complemented by regional variables (water flow and precipitation. A total of 43,475 eggs and 2,269 larvae were captured. Of these larvae, 80.1% were in the pre-flexion and larval yolk stages. Digestive tract content showed that the greatest degree of repletion among the larvae in more advanced phases occurred in the pool environment. Water speed was the main characteristic used to differentiate the river's rapids and mouth from the pool. The abundance of zooplankton and benthos was not related to the distribution of densities among the different components of the ichthyoplankton. A greater abundance of eggs and larvae with yolk was found in the rapids and river mouth. Ordination analyses showed a connection between the advanced stage larvae and the pool environment. In conclusion, the rapids and river mouth of the Ligeiro River's are important locations for fish reproduction, particularly in regard to spawning and drifting of the ichthyoplankton's initial stages, whereas the pool represents a nursery place for larval growth.

  13. Assessment of regional air quality resulting from emission control in the Pearl River Delta region, southern China.

    Science.gov (United States)

    Wang, N; Lyu, X P; Deng, X J; Guo, H; Deng, T; Li, Y; Yin, C Q; Li, F; Wang, S Q

    2016-12-15

    To evaluate the impact of emission control measures on the air quality in the Pearl River Delta (PRD) region of South China, statistic data including atmospheric observations, emissions and energy consumptions during 2006-2014 were analyzed, and a Weather Research and Forecasting - Community Multi-scale Air Quality (WRF-CMAQ) model was used for various scenario simulations. Although energy consumption doubled from 2004 to 2014 and vehicle number significantly increased from 2006 to 2014, ambient SO 2 , NO 2 and PM 10 were reduced by 66%, 20% and 24%, respectively, mainly due to emissions control efforts. In contrast, O 3 increased by 19%. Model simulations of three emission control scenarios, including a baseline (a case in 2010), a CAP (a case in 2020 assuming control strength followed past control tendency) and a REF (a case in 2020 referring to the strict control measures based on recent policy/plans) were conducted to investigate the variations of air pollutants to the changes in NO x , VOCs and NH 3 emissions. Although the area mean concentrations of NO x , nitrate and PM 2.5 decreased under both NO x CAP (reduced by 1.8%, 0.7% and 0.2%, respectively) and NO x REF (reduced by 7.2%, 1.8% and 0.3%, respectively), a rising of PM 2.5 was found in certain areas as reducing NO x emissions elevated the atmospheric oxidizability. Furthermore, scenarios with NH 3 emission reductions showed that nitrate was sensitive to NH 3 emissions, with decreasing percentages of 0-10.6% and 0-48% under CAP and REF, respectively. Controlling emissions of VOCs reduced PM 2.5 in the southwestern PRD where severe photochemical pollution frequently occurred. It was also found that O 3 formation in PRD was generally VOCs-limited while turned to be NO x -limited in the afternoon (13:00-17:00), suggesting that cutting VOCs emissions would reduce the overall O 3 concentrations while mitigating NO x emissions in the afternoon could reduce the peak O 3 levels. Copyright © 2016 Elsevier B

  14. [Work-related accidents in traditional fishermen from the Medium Araguaia River region, Tocantins, Brazil].

    Science.gov (United States)

    Garrone Neto, Domingos; Cordeiro, Ricardo Carlos; Haddad, Vidal

    2005-01-01

    This is a cross-sectional study of work-related accidents among traditional fishermen in the Medium Araguaia River region of Tocantins, Brazil. From June to August 2002, fishermen from the Municipality of Araguacema were interviewed about the organization of their work activities and work-related accidents during the previous six months. Of the 92 participating fishermen, 56 reported having suffered a work-related accident (annual incidence was 82.6%). Some 95.7% of those interviewed did not regularly pay social security insurance as self-employed workers and were not aware of their social rights and duties. For fishermen reporting accidents, this proportion was 98.2%. Approximately 23.0% had another work activity, mainly as construction workers (47.6%) or sport-fishing guides (23.9%). Injuries inflicted by aquatic animals were the main form of accidents (about 86.0%). From these results, it is apparent that accidents from aquatic animals are an important health hazard, in some cases causing temporary work incapacity.

  15. Quebec region's shoreline segmentation in the St. Lawrence River : response tool for oil spills

    International Nuclear Information System (INIS)

    Laforest, S.; Martin, V.

    2004-01-01

    Environment Canada, the Canadian Coast Guard, and the Eastern Canada Response Corporation are developing and refining pre-spill databases containing information about physical shoreline characteristics. Automated links between these pre-spill shoreline characteristic databases and computerized shoreline assessment tools have also been created using Geographical Information System (GIS) technology. The pre-spill databases can be used for planning shoreline cleanup operations. A training exercise, designed to evaluate a spill management system integrating the Quebec region pre-spill shoreline database and the ShoreAssess R shoreline assessment system was performed by Eastern Canada Response Corporation during an aerial survey where shoreline was segmented into digitized information. The cartography of segmentation covers the fluvial part of the St. Lawrence River. The oil spill-oriented database includes geomorphologic information from the supratidal to the lower intertidal zones. It also includes some statistical information and other requirements for cleanup operations. The computerized shoreline assessment tools made it possible to evaluate the length and type of shoreline that would potentially be impacted by oil. The tools also made it possible to assess the shoreline treatment methods most likely to be used, and evaluate the probable duration of the cleanup operation. The training exercise demonstrated that the integration of the databases is a valuable tool during the early phases of an oil spill response. 9 refs., 3 figs

  16. Environmental lead pollution threatens the children living in the Pearl River Delta region, China.

    Science.gov (United States)

    Chen, Jianmin; Tong, Yongpeng; Xu, Jiazhang; Liu, Xiaoli; Li, Yulan; Tan, Mingguang; Li, Yan

    2012-09-01

    The objective of this study is to determine children's blood lead levels and identify sources of lead exposure. Childhood lead exposure constitutes a major pediatric health problem today in China. A blood lead screening survey program for children in the age group of 2-12 years residing in Pearl River Delta region, south of China, was carried out from Dec 2007 to Jan 2008. Blood lead levels and lead isotope ratios of a total of 761 participants were assessed by inductively coupled plasma mass spectroscopy. Measurements of urban environmental samples for source identification of children lead exposure were also performed. The geometric mean value of the children's blood lead levels was 57.05 μg/L, and 9.6% of them were higher than 100 μg/L. The blood lead levels were still much higher than those in developed countries. Based on the data of environmental lead source inventories, lead isotopic tracing revealed that there is about 6.7% past used gasoline Pb embedded in Shenzhen residential dust and about 15.6% in Guangzhou dust, respectively.

  17. River-damming, late-Quaternary rockslides in the Ötz Valley region (Tyrol, Austria)

    Science.gov (United States)

    Dufresne, A.; Ostermann, M.; Preusser, F.

    2018-06-01

    The Ötz Valley and adjacent regions in Tyrol (Austria) have been repeatedly affected by large rockslope failures following deglaciation. Six rockslides, each over 107 m3 in volume, were emplaced into the Ötz and Inn valleys, five of which formed persistent rockslide dams. Even though catastrophic rockslope failures are short-lived events (commonly minutes) they can have long-lasting impacts on the landscape. For example, large fans have built in the Ötz Valley and knickpoints persist at the former dam sites even though the Ötz River has eroded through the deposits during the past thousands of years; exact age-constraints of rockslide dam failure, however, are still scarce. Empirical, geomorphic stability indices from the literature successfully identified the least and the most stable dams of this group, whereas the rest remain inconclusive with some indices variably placing the dams in the stable, unstable, and uncertain categories. This shows (a) that further index calibrations and (b) better age constraints on dam formation and failure are needed, and (c) that the exact processes of dam failure are not always trivial to pinpoint for ancient (partially) breached dams. This study is a contribution towards better constraining the nature and landscape impact of dam formation following large rockslope failures.

  18. Regional-scale controls on dissolved nitrous oxide in the Upper Mississippi River

    Science.gov (United States)

    Turner, P.A.; Griffis, T.J.; Baker, J.M.; Lee, X.; Crawford, John T.; Loken, Luke C.; Venterea, R.T.

    2016-01-01

    The U.S. Corn Belt is one of the most intensive agricultural regions of the world and is drained by the Upper Mississippi River (UMR), which forms one of the largest drainage basins in the U.S. While the effects of agricultural nitrate (NO3-) on water quality in the UMR have been well documented, its impact on the production of nitrous oxide (N2O) has not been reported. Using a novel equilibration technique, we present the largest data set of freshwater dissolved N2O concentrations (0.7 to 6 times saturation) and examine the controls on its variability over a 350 km reach of the UMR. Driven by a supersaturated water column, the UMR was an important atmospheric N2O source (+68 mg N2ONm-2 yr-1) that varies nonlinearly with the NO3-concentration. Our analyses indicated that a projected doubling of the NO3-concentration by 2050 would cause dissolved N2O concentrations and emissions to increase by about 40%.

  19. Regionalization Study of Satellite based Hydrological Model (SHM) in Hydrologically Homogeneous River Basins of India

    Science.gov (United States)

    Kumari, Babita; Paul, Pranesh Kumar; Singh, Rajendra; Mishra, Ashok; Gupta, Praveen Kumar; Singh, Raghvendra P.

    2017-04-01

    A new semi-distributed conceptual hydrological model, namely Satellite based Hydrological Model (SHM), has been developed under 'PRACRITI-2' program of Space Application Centre (SAC), Ahmedabad for sustainable water resources management of India by using data from Indian Remote Sensing satellites. Entire India is divided into 5km x 5km grid cells and properties at the center of the cells are assumed to represent the property of the cells. SHM contains five modules namely surface water, forest, snow, groundwater and routing. Two empirical equations (SCS-CN and Hargreaves) and water balance method have been used in the surface water module; the forest module is based on the calculations of water balancing & dynamics of subsurface. 2-D Boussinesq equation is used for groundwater modelling which is solved using implicit finite-difference. The routing module follows a distributed routing approach which requires flow path and network with the key point of travel time estimation. The aim of this study is to evaluate the performance of SHM using regionalization technique which also checks the usefulness of a model in data scarce condition or for ungauged basins. However, homogeneity analysis is pre-requisite to regionalization. Similarity index (Φ) and hierarchical agglomerative cluster analysis are adopted to test the homogeneity in terms of physical attributes of three basins namely Brahmani (39,033 km km^2)), Baitarani (10,982 km km^2)) and Kangsabati (9,660 km km^2)) with respect to Subarnarekha (29,196 km km^2)) basin. The results of both homogeneity analysis show that Brahmani basin is the most homogeneous with respect to Subarnarekha river basin in terms of physical characteristics (land use land cover classes, soiltype and elevation). The calibration and validation of model parameters of Brahmani basin is in progress which are to be transferred into the SHM set up of Subarnarekha basin and results are to be compared with the results of calibrated and validated

  20. The oldest record of Alligator sinensis from the Late Pliocene of Western Japan, and its biogeographic implication

    Science.gov (United States)

    Iijima, Masaya; Takahashi, Keiichi; Kobayashi, Yoshitsugu

    2016-07-01

    The late Cenozoic fossil record of alligators in East Asia is crucial in understanding the origin and past distribution of Asian alligators that are now represented by a single species, Alligator sinensis. This study reports a partial skeleton of A. sinensis from the Late Pliocene (approximately 3.0 Ma) of western Japan. This Japanese A. sinensis is large in size (>200 cm total length), comparable to the maximum size of extant individuals. It demonstrates the oldest record of A. sinensis and wider distribution of this species in the past. Tectonic and geographic history of East Asia suggests that alligators presumably dispersed into Japan before 25 Ma or after 10 Ma, yet finally were wiped out from Japan due to the semi-isolated condition of the Japanese island arc and the deteriorated climate during the Plio-Pleistocene.

  1. A new distributional record of alligator pipefish, Syngnathoides biaculeatus (Bloch, 1785) along Goa, central west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Sanaye, S.V.; Rivonker, C.U.; Ansari, Z.A; Sreepada, R.A

    Present study is based on a single male specimen of alligator pipefish, Syngnathoides biaculeatus (Bloch, 1785) collected from the bay-estuarine system of, Goa (central west coast of India) which is the new distributional record for this species. A...

  2. Simulation of Regional Ground-Water Flow in the Suwannee River Basin, Northern Florida and Southern Georgia

    Science.gov (United States)

    Planert, Michael

    2007-01-01

    The Suwannee River Basin covers a total of nearly 9,950 square miles in north-central Florida and southern Georgia. In Florida, the Suwannee River Basin accounts for 4,250 square miles of north-central Florida. Evaluating the impacts of increased development in the Suwannee River Basin requires a quantitative understanding of the boundary conditions, hydrogeologic framework and hydraulic properties of the Floridan aquifer system, and the dynamics of water exchanges between the Suwannee River and its tributaries and the Floridan aquifer system. Major rivers within the Suwannee River Basin are the Suwannee, Santa Fe, Alapaha, and Withlacoochee. Four rivers west of the Suwannee River are the Aucilla, the Econfina, the Fenholloway, and the Steinhatchee; all drain to the Gulf of Mexico. Perhaps the most notable aspect of the surface-water hydrology of the study area is that large areas east of the Suwannee River are devoid of channelized, surface drainage; consequently, most of the drainage occurs through the subsurface. The ground-water flow system underlying the study area plays a critical role in the overall hydrology of this region of Florida because of the dominance of subsurface drain-age, and because ground-water flow sustains the flow of the rivers and springs. Three principal hydrogeologic units are present in the study area: the surficial aquifer system, the intermediate aquifer system, and the Floridan aquifer system. The surficial aquifer system principally consists of unconsoli-dated to poorly indurated siliciclastic deposits. The intermediate aquifer system, which contains the intermediate confining unit, lies below the surficial aquifer system (where present), and generally consists of fine-grained, uncon-solidated deposits of quartz sand, silt, and clay with interbedded limestone of Miocene age. Regionally, the intermediate aquifer system and intermediate con-fining unit act as a confining unit that restricts the exchange of water between the over

  3. Influence of land cover on riverine dissolved organic carbon concentrations and export in the Three Rivers Headwater Region of the Qinghai-Tibetan Plateau.

    Science.gov (United States)

    Ma, Xiaoliang; Liu, Guimin; Wu, Xiaodong; Smoak, Joseph M; Ye, Linlin; Xu, Haiyan; Zhao, Lin; Ding, Yongjian

    2018-07-15

    The Qinghai-Tibetan plateau (QTP) stores a large amount of soil organic carbon and is the headwater region for several large rivers in Asia. Therefore, it is important to understand the influence of environmental factors on river water quality and the dissolved organic carbon (DOC) export in this region. We examined the water physico-chemical characteristics, DOC concentrations and export rates of 7 rivers under typical land cover types in the Three Rivers Headwater Region during August 2016. The results showed that the highest DOC concentrations were recorded in the rivers within the catchment of alpine wet meadow and meadow. These same rivers had the lowest total suspended solids (TSS) concentrations. The rivers within steppe and desert had the lowest DOC concentrations and highest TSS concentrations. The discharge rates and catchment areas were negatively correlated with DOC concentrations. The SUVA 254 values were significantly negatively correlated with DOC concentrations. The results suggest that the vegetation degradation, which may represent permafrost degradation, can lead to a decrease in DOC concentration, but increasing DOC export and soil erosion. In addition, some of the exported DOC will rapidly decompose in the river, and therefore affect the regional carbon cycle, as well as the water quality in the source water of many large Asian rivers. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. Modelling and Analysis of Hydrodynamics and Water Quality for Rivers in the Northern Cold Region of China.

    Science.gov (United States)

    Tang, Gula; Zhu, Yunqiang; Wu, Guozheng; Li, Jing; Li, Zhao-Liang; Sun, Jiulin

    2016-04-08

    In this study, the Mudan River, which is the most typical river in the northern cold region of China was selected as the research object; Environmental Fluid Dynamics Code (EFDC) was adopted to construct a new two-dimensional water quality model for the urban sections of the Mudan River, and concentrations of COD(Cr) and NH₃N during ice-covered and open-water periods were simulated and analyzed. Results indicated that roughness coefficient and comprehensive pollutant decay rate were significantly different in those periods. To be specific, the roughness coefficient in the ice-covered period was larger than that of the open-water period, while the decay rate within the former period was smaller than that in the latter. In addition, according to the analysis of the simulated results, the main reasons for the decay rate reduction during the ice-covered period are temperature drop, upstream inflow decrease and ice layer cover; among them, ice sheet is the major contributor of roughness increase. These aspects were discussed in more detail in this work. The model could be generalized to hydrodynamic water quality process simulation researches on rivers in other cold regions as well.

  5. Modelling and Analysis of Hydrodynamics and Water Quality for Rivers in the Northern Cold Region of China

    Directory of Open Access Journals (Sweden)

    Gula Tang

    2016-04-01

    Full Text Available In this study, the Mudan River, which is the most typical river in the northern cold region of China was selected as the research object; Environmental Fluid Dynamics Code (EFDC was adopted to construct a new two-dimensional water quality model for the urban sections of the Mudan River, and concentrations of CODCr and NH3N during ice-covered and open-water periods were simulated and analyzed. Results indicated that roughness coefficient and comprehensive pollutant decay rate were significantly different in those periods. To be specific, the roughness coefficient in the ice-covered period was larger than that of the open-water period, while the decay rate within the former period was smaller than that in the latter. In addition, according to the analysis of the simulated results, the main reasons for the decay rate reduction during the ice-covered period are temperature drop, upstream inflow decrease and ice layer cover; among them, ice sheet is the major contributor of roughness increase. These aspects were discussed in more detail in this work. The model could be generalized to hydrodynamic water quality process simulation researches on rivers in other cold regions as well.

  6. Centennial- to decadal-scale monsoon precipitation variations in the upper Hanjiang River region, China over the past 6650 years

    Science.gov (United States)

    Tan, Liangcheng; Cai, Yanjun; Cheng, Hai; Edwards, Lawrence R.; Gao, Yongli; Xu, Hai; Zhang, Haiwei; An, Zhisheng

    2018-01-01

    The upper Hanjiang River region is the recharge area of the middle route of South-to-North Water Transfer Project. The region is under construction of the Hanjiang-Weihe River Water Transfer Project in China. Monsoon precipitation variations in this region are critical to water resource and security of China. In this study, high-resolution monsoon precipitation variations were reconstructed in the upper Hanjiang River region over the past 6650 years from δ18O and δ13C records of four stalagmites in Xianglong cave. The long term increasing trend of stalagmite δ18O record since the middle Holocene is consistent with other speleothem records from monsoonal China. This trend follows the gradually decreasing Northern Hemisphere summer insolation, which indicates that solar insolation may control the orbital-scale East Asian summer monsoon (EASM) variations. Despite the declined EASM intensity since the middle Holocene, local precipitation may not have decreased remarkably, as revealed by the δ13C records. A series of centennial- to decadal-scale cyclicity was observed, with quasi-millennium-, quasi-century-, 57-, 36- and 22-year cycles by removing the long-term trend of stalagmite δ18O record. Increased monsoon precipitation during periods of 4390-3800 a BP, 3590-2960 a BP, 2050-1670 a BP and 1110-790 a BP had caused four super-floods in the upper reach of Hanjiang River. Dramatically dry climate existed in this region during the 5.0 ka and 2.8 ka events, coinciding with notable droughts in other regions of monsoonal China. Remarkably intensified and southward Westerly jet, together with weakened summer monsoon, may delay the onset of rainy seasons, resulting in synchronous decreasing of monsoon precipitation in China during the two events. During the 4.2 ka event and the Little Ice Age, the upper Hanjiang River region was wet, which was similar to the climate conditions in central and southern China, but was the opposite of drought observed in northern China. We

  7. Simulation of regional-scale groundwater flow in the Azul River basin, Buenos Aires Province, Argentina

    Science.gov (United States)

    Varni, Marcelo R.; Usunoff, Eduardo J.

    A three-dimensional modular model (MODFLOW) was used to simulate groundwater flow in the Azul River basin, Buenos Aires Province, Argentina, in order to assess the correctness of the conceptual model of the hydrogeological system. Simulated heads satisfactorily match observed heads in the regional water-table aquifer. Model results indicate that: (1) groundwater recharge is not uniform throughout the region but is best represented by three recharge rates, decreasing downgradient, similar to the distribution of soils and geomorphological characteristics; and (2) evapotranspiration rates are larger than previous estimates, which were made by using the Thornthwaite-Mather method. Evapotranspiration rates estimated by MODFLOW agree with results of independent studies of the region. Model results closely match historical surface-flow records, thereby suggesting that the model description of the aquifer-river relationship is correct. Résumé Un modèle modulaire tridimensionnel (MODFLOW) a été utilisé pour simuler les écoulements souterrains dans le bassin de la rivière Azul (Province de Buenos Aires, Argentine), dans le but d'évaluer la justesse du modèle conceptuel du système hydrogéologique. La piézométrie simulée s'ajuste de façon satisfaisante à celle observée pour l'ensemble de la nappe. Les résultats du modèle indiquent que: (1) la recharge de la nappe n'est pas uniforme sur toute la région, mais qu'elle est mieux approchée par trois valeurs différentes, décroissant vers l'aval-gradient, en suivant la même distribution que les sols et les caractéristiques géomorphologiques et (2) l'évapotranspiration est nettement plus importante que prévu initialement à partir de la méthode de Thornthwaite-Mather. Les valeurs d'évapotranspiration fournies par MODFLOW concordent bien avec les résultats d'autres études portant sur la région. Les résultats du modèle reproduisent convenablement les chroniques de débit des écoulements de surface

  8. When local extinction and colonization of river fishes can be predicted by regional occupancy: the role of spatial scales.

    Directory of Open Access Journals (Sweden)

    Benjamin Bergerot

    Full Text Available Predicting which species are likely to go extinct is perhaps one of the most fundamental yet challenging tasks for conservation biologists. This is particularly relevant for freshwater ecosystems which tend to have the highest proportion of species threatened with extinction. According to metapopulation theories, local extinction and colonization rates of freshwater subpopulations can depend on the degree of regional occupancy, notably due to rescue effects. However, relationships between extinction, colonization, regional occupancy and the spatial scales at which they operate are currently poorly known.And Findings: We used a large dataset of freshwater fish annual censuses in 325 stream reaches to analyse how annual extinction/colonization rates of subpopulations depend on the regional occupancy of species. For this purpose, we modelled the regional occupancy of 34 fish species over the whole French river network and we tested how extinction/colonization rates could be predicted by regional occupancy described at five nested spatial scales. Results show that extinction and colonization rates depend on regional occupancy, revealing existence a rescue effect. We also find that these effects are scale dependent and their absolute contribution to colonization and extinction tends to decrease from river section to larger basin scales.In terms of management, we show that regional occupancy quantification allows the evaluation of local species extinction/colonization dynamics and reduction of local extinction risks for freshwater fish species implies the preservation of suitable habitats at both local and drainage basin scales.

  9. When local extinction and colonization of river fishes can be predicted by regional occupancy: the role of spatial scales.

    Science.gov (United States)

    Bergerot, Benjamin; Hugueny, Bernard; Belliard, Jérôme

    2013-01-01

    Predicting which species are likely to go extinct is perhaps one of the most fundamental yet challenging tasks for conservation biologists. This is particularly relevant for freshwater ecosystems which tend to have the highest proportion of species threatened with extinction. According to metapopulation theories, local extinction and colonization rates of freshwater subpopulations can depend on the degree of regional occupancy, notably due to rescue effects. However, relationships between extinction, colonization, regional occupancy and the spatial scales at which they operate are currently poorly known. And Findings: We used a large dataset of freshwater fish annual censuses in 325 stream reaches to analyse how annual extinction/colonization rates of subpopulations depend on the regional occupancy of species. For this purpose, we modelled the regional occupancy of 34 fish species over the whole French river network and we tested how extinction/colonization rates could be predicted by regional occupancy described at five nested spatial scales. Results show that extinction and colonization rates depend on regional occupancy, revealing existence a rescue effect. We also find that these effects are scale dependent and their absolute contribution to colonization and extinction tends to decrease from river section to larger basin scales. In terms of management, we show that regional occupancy quantification allows the evaluation of local species extinction/colonization dynamics and reduction of local extinction risks for freshwater fish species implies the preservation of suitable habitats at both local and drainage basin scales.

  10. Non-methane hydrocarbon characteristics of motor vehicular emissions in the Pearl River Delta region

    Science.gov (United States)

    Tsai, Wai Yan

    2007-12-01

    Air pollution problem in Hong Kong and the Pearl River Delta (PRD) region has raised much concern from the public in recent years. The primary aim of this research is to use field measurement data to characterize non-methane hydrocarbons (NMHCs) in emission from motor vehicles. Fuel vapor compositions for several commonly used vehicular fuels in Hong Kong, Macau, Guangzhou and Zhuhai were analyzed in 2003, and they are believed to be the first one reported for the PRD region. These profiles were used to study the impact of evaporative loss of the fuels on air quality. From the roadside and tunnel samples collected in the four cities mentioned above from 2000 to 2003, results showed that vehicular engine combustion was a main NMHC source, while gasoline evaporative losses also contributed much to the total NMHC emission, besides, LPG leakage was also found to be significant from the tunnel measurement data collected in Hong Kong. Characteristics of vehicular engine exhaust emissions were also studied. Measurements of diesel emission showed a large influence on the emission profile due to the change of diesel compositions. The E/E ratios implied that gasoline-powered vehicles in Hong Kong were equipped with well functioning catalysts, while those in Guangzhou and Zhuhai, especially the motorcycles, were found dirtier in NMHC emission. Although the E/E ratios showed that private cars in Hong Kong had high combustion efficiency, the existence of significant amounts of unburned gasoline in their exhaust stream pointed out that they still had low fuel economy. From the results of a simple model, it was found that the evaporative losses of gasoline and LPG contributed much to the total NMHC pollution from vehicle. The preliminary results from the dynamometer study conducted in Hong Kong showed large variations of exhaust characteristics for private cars and taxis during different driving speeds. The results can be used as scientific basis for regulatory parties in

  11. Regional economic analysis of current and proposed management alternatives for Rappahannock River Valley National Wildlife Refuge

    Science.gov (United States)

    Koontz, Lynne; Sexton, Natalie; Donovan, Ryan

    2009-01-01

    The National Wildlife Refuge System Improvement Act of 1997 requires all units of the National Wildlife Refuge System to be managed under a Comprehensive Conservation Plan. The Comprehensive Conservation Plan must describe the desired future conditions of a refuge and provide long-range guidance and management direction to achieve refuge purposes. The Rappahannock River Valley National Wildlife Refuge (refuge) is in the process of developing a range of management goals, objectives, and strategies for the Comprehensive Conservation Plan. The Comprehensive Conservation Plan for the refuge must contain an analysis of expected effects associated with current and proposed refuge management strategies. The purpose of this study was to assess the regional economic implications associated with draft Comprehensive Conservation Plan management strategies. Special interest groups and local residents often criticize a change in refuge management, especially if there is a perceived negative impact to the local economy. Having objective data on economic impacts may show that these fears are overstated. Quite often, the extent of economic benefits a refuge provides to a local community is not fully recognized, yet at the same time the effects of negative changes is overstated. Spending associated with refuge recreational activities, such as wildlife viewing and hunting, can generate considerable tourist activity for surrounding communities. Additionally, refuge personnel typically spend considerable amounts of money purchasing supplies in local stores, repairing equipment and purchasing fuel at the local service stations, and reside and spend their salaries in the local community. For refuge Comprehensive Conservation Plan planning, a regional economic assessment provides a means of estimating how current management (no action alternative) and proposed management activities (alternatives) could affect the local economy. This type of analysis provides two critical pieces of

  12. Hydrologic Conditions that Influence Streamflow Losses in a Karst Region of the Upper Peace River, Polk County, Florida

    Science.gov (United States)

    Metz, P.A.; Lewelling, B.R.

    2009-01-01

    The upper Peace River from Bartow to Fort Meade, Florida, is described as a groundwater recharge area, reflecting a reversal from historical groundwater discharge patterns that existed prior to the 1950s. The upper Peace River channel and floodplain are characterized by extensive karst development, with numerous fractures, crevasses, and sinks that have been eroded in the near-surface and underlying carbonate bedrock. With the reversal in groundwater head gradients, river water is lost to the underlying groundwater system through these karst features. An investigation was conducted to evaluate the hydrologic conditions that influence streamflow losses in the karst region of the upper Peace River. The upper Peace River is located in a basin that has been altered substantially by phosphate mining and increases in groundwater use. These alterations have changed groundwater flow patterns and caused streamflow declines through time. Hydrologic factors that have had the greatest influence on streamflow declines in the upper Peace River include the lowering of the potentiometric surfaces of the intermediate aquifer system and Upper Floridan aquifer beneath the riverbed elevation due to below-average rainfall (droughts), increases in groundwater use, and the presence of numerous karst features in the low-water channel and floodplain that enhance the loss of streamflow. Seepage runs conducted along the upper Peace River, from Bartow to Fort Meade, indicate that the greatest streamflow losses occurred along an approximate 2-mile section of the river beginning about 1 mile south of the Peace River at Bartow gaging station. Along the low-water and floodplain channel of this 2-mile section, there are about 10 prominent karst features that influence streamflow losses. Losses from the individual karst features ranged from 0.22 to 16 cubic feet per second based on measurements made between 2002 and 2007. The largest measured flow loss for all the karst features was about 50 cubic

  13. Characterizing and modelling river channel migration rates at a regional scale: Case study of south-east France.

    Science.gov (United States)

    Alber, Adrien; Piégay, Hervé

    2017-11-01

    An increased awareness by river managers of the importance of river channel migration to sediment dynamics, habitat complexity and other ecosystem functions has led to an advance in the science and practice of identifying, protecting or restoring specific erodible corridors across which rivers are free to migrate. One current challenge is the application of these watershed-specific goals at the regional planning scales (e.g., the European Water Framework Directive). This study provides a GIS-based spatial analysis of the channel migration rates at the regional-scale. As a case study, 99 reaches were sampled in the French part of the Rhône Basin and nearby tributaries of the Mediterranean Sea (111,300 km 2 ). We explored the spatial correlation between the channel migration rate and a set of simple variables (e.g., watershed area, channel slope, stream power, active channel width). We found that the spatial variability of the channel migration rates was primary explained by the gross stream power (R 2  = 0.48) and more surprisingly by the active channel width scaled by the watershed area. The relationship between the absolute migration rate and the gross stream power is generally consistent with the published empirical models for freely meandering rivers, whereas it is less significant for the multi-thread reaches. The discussion focused on methodological constraints for a regional-scale modelling of the migration rates, and the interpretation of the empirical models. We hypothesize that the active channel width scaled by the watershed area is a surrogate for the sediment supply which may be a more critical factor than the bank resistance for explaining the regional-scale variability of the migration rates. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Heavy Metal Pollution in a Soil-Rice System in the Yangtze River Region of China.

    Science.gov (United States)

    Liu, Zhouping; Zhang, Qiaofen; Han, Tiqian; Ding, Yanfei; Sun, Junwei; Wang, Feijuan; Zhu, Cheng

    2015-12-22

    Heavy metals are regarded as toxic trace elements in the environment. Heavy metal pollution in soil or rice grains is of increasing concern. In this study, 101 pairs of soil and rice samples were collected from the major rice-producing areas along the Yangtze River in China. The soil properties and heavy metal (i.e., Cd, Hg, Pb and Cr) concentrations in the soil and rice grains were analyzed to evaluate the heavy metal accumulation characteristics of the soil-rice systems. The results showed that the Cd, Hg, Pb and Cr concentrations in the soil ranged from 0.10 to 4.64, 0.01 to 1.46, 7.64 to 127.56, and 13.52 to 231.02 mg·kg(-)¹, respectively. Approximately 37%, 16%, 60% and 70% of the rice grain samples were polluted by Cd, Hg, Pb, and Cr, respectively. The degree of heavy metal contamination in the soil-rice systems exhibited a regional variation. The interactions among the heavy metal elements may also influence the migration and accumulation of heavy metals in soil or paddy rice. The accumulation of heavy metals in soil and rice grains is related to a certain extent to the pH and soil organic matter (SOM). This study provides useful information regarding heavy metal accumulation in soil to support the safe production of rice in China. The findings from this study also provide a robust scientific basis for risk assessments regarding ecological protection and food safety.

  15. Sources and characteristics of carbonaceous aerosol in two largest cities in Pearl River Delta Region, China

    Science.gov (United States)

    Duan, Jingchun; Tan, Jihua; Cheng, Dingxi; Bi, Xinhui; Deng, Wenjing; Sheng, Guoying; Fu, Jiamo; Wong, M. H.

    PM 2.5 samples were collected at five sites in Guangzhou and Hong Kong, Pearl River Delta Region (PRDR), China in both summer and winter during 2004-2005. Elemental carbon (EC) and organic carbon (OC) in these samples were measured. The OC and EC concentrations ranked in the order of urban Guangzhou > urban Hong Kong > background Hong Kong. Total carbonaceous aerosol (TCA) contributed less to PM 2.5 in urban Guangzhou (32-35%) than that in urban Hong Kong (43-57%). The reason may be that, as an major industrial city in South China, Guangzhou would receive large amount of inorganic aerosol from all kinds of industries, however, as a trade center and seaport, urban Hong Kong would mainly receive organic aerosol and EC from container vessels and heavy-duty diesel trucks. At Hong Kong background site Hok Tsui, relatively lower contribution of TCA to PM 2.5 may result from contributions of marine inorganic aerosol and inland China pollutant. Strong correlation ( R2=0.76-0.83) between OC and EC indicates minor fluctuation of emission and the secondary organic aerosol (SOA) formation in urban Guangzhou. Weak correlation between OC and EC in Hong Kong can be related to the impact of the long-range transported aerosol from inland China. Averagely, secondary OC (SOC) concentrations were 3.8-5.9 and 10.2-12.8 μg m -3, respectively, accounting for 21-32% and 36-42% of OC in summer and winter in Guangzhou. The average values of 4.2-6.8% for SOA/ PM 2.5 indicate that SOA was minor component in PM 2.5 in Guangzhou.

  16. Heavy Metal Pollution in a Soil-Rice System in the Yangtze River Region of China

    Directory of Open Access Journals (Sweden)

    Zhouping Liu

    2015-12-01

    Full Text Available Heavy metals are regarded as toxic trace elements in the environment. Heavy metal pollution in soil or rice grains is of increasing concern. In this study, 101 pairs of soil and rice samples were collected from the major rice-producing areas along the Yangtze River in China. The soil properties and heavy metal (i.e., Cd, Hg, Pb and Cr concentrations in the soil and rice grains were analyzed to evaluate the heavy metal accumulation characteristics of the soil-rice systems. The results showed that the Cd, Hg, Pb and Cr concentrations in the soil ranged from 0.10 to 4.64, 0.01 to 1.46, 7.64 to 127.56, and 13.52 to 231.02 mg·kg−1, respectively. Approximately 37%, 16%, 60% and 70% of the rice grain samples were polluted by Cd, Hg, Pb, and Cr, respectively. The degree of heavy metal contamination in the soil-rice systems exhibited a regional variation. The interactions among the heavy metal elements may also influence the migration and accumulation of heavy metals in soil or paddy rice. The accumulation of heavy metals in soil and rice grains is related to a certain extent to the pH and soil organic matter (SOM. This study provides useful information regarding heavy metal accumulation in soil to support the safe production of rice in China. The findings from this study also provide a robust scientific basis for risk assessments regarding ecological protection and food safety.

  17. Pollen flow of wheat under natural conditions in the Huanghuai River Wheat Region, China

    Science.gov (United States)

    Sun, Ai-Qing; Zhang, Chun-Qing; Wu, Cheng-Lai; Gao, Qing-Rong

    2015-01-01

    abstract The transgenic pollen spread is the main pathway of transgenic plant gene flow. The maximum distance of pollen dispersal (horizontal), the spatial dynamics of pollen movement (vertical), and the patterns of pollen dispersal are important considerations in biosafety assessments of genetically modified crops. To evaluate wheat (Triticum aestivum) pollen dispersal, we measured the pollen suspension velocity and analyzed pollen dispersal patterns under natural conditions in the Huanghuai River wheat-growing region in 2009. The pollen suspension velocity was 0.3–0.4 m/s. The highest pollen densities were detected in the north, northwest, and south of the pollen source. Pollen was dispersed over distances greater than 245 m in the northwest and northeast directions. At the pollen source center, pollen density decreased with increasing vertical height. In the north of the pollen source, the pollen density from 65 m to 225 m showed a wave-mode decrease with increasing height. The horizontal transport of pollen over longer distances fitted polynomial equations. In the north, the pollen density was highest at 45 m from the pollen source, and decreased with increasing distance. In the northwest, the pollen density showed a double-peak trend. In the northeast, pollen density was highest from 45 m to 125 m from the source. Wind speeds greater than the pollen suspension velocity and the duration of continuous gusts were the main factors affecting pollen dispersal. This information will be useful for determining the spatial isolation distances for hybrid seed production and for the commercial production of transgenic wheat. PMID:25658025

  18. Heavy Metal Pollution in a Soil-Rice System in the Yangtze River Region of China

    Science.gov (United States)

    Liu, Zhouping; Zhang, Qiaofen; Han, Tiqian; Ding, Yanfei; Sun, Junwei; Wang, Feijuan; Zhu, Cheng

    2015-01-01

    Heavy metals are regarded as toxic trace elements in the environment. Heavy metal pollution in soil or rice grains is of increasing concern. In this study, 101 pairs of soil and rice samples were collected from the major rice-producing areas along the Yangtze River in China. The soil properties and heavy metal (i.e., Cd, Hg, Pb and Cr) concentrations in the soil and rice grains were analyzed to evaluate the heavy metal accumulation characteristics of the soil-rice systems. The results showed that the Cd, Hg, Pb and Cr concentrations in the soil ranged from 0.10 to 4.64, 0.01 to 1.46, 7.64 to 127.56, and 13.52 to 231.02 mg·kg−1, respectively. Approximately 37%, 16%, 60% and 70% of the rice grain samples were polluted by Cd, Hg, Pb, and Cr, respectively. The degree of heavy metal contamination in the soil-rice systems exhibited a regional variation. The interactions among the heavy metal elements may also influence the migration and accumulation of heavy metals in soil or paddy rice. The accumulation of heavy metals in soil and rice grains is related to a certain extent to the pH and soil organic matter (SOM). This study provides useful information regarding heavy metal accumulation in soil to support the safe production of rice in China. The findings from this study also provide a robust scientific basis for risk assessments regarding ecological protection and food safety. PMID:26703698

  19. Effects of the Changiang river discharge on the change in ocean and atmosphere over the East Asian region

    Science.gov (United States)

    Kim, M. H.; Lim, Y. J.; Kang, H. S.; Kim, B. J.; Cho, C.

    2017-12-01

    This study investigates the effects of freshwater from the Changiang river basin over the East Asian region for summer season. To do this, we simulated global seasonal forecasting system (GloSea5) of KMA (Korea Meteorology Administration). GloSea5 consists of atmosphere, ocean, sea ice and land model. Also, it has river routing model (TRIP), which links between land and ocean using freshwater. It is very important component in long-term forecast because of be able to change the air-sea interaction. To improve more the freshwater performance over the East Asian region, we realistically modified the river mouth, direction and storage around Changiang river basin of TRIP in GloSea5. Here, the comparison study among the no freshwater forcing experiment to ocean model (TRIP-OFF), the operated original file based freshwater coupled experiment (TRIP-ON) and the improved one (TRIP-MODI) has been carried out and the results are evaluated against the reanalysis data. As a result, the amount of fresh water to the Yellow Sea increase in TRIP-ON experiment and it attributes to the improvement of bias and RMSE of local SST over the East Asia. The implementation of the realistic river related ancillary files (TRIP-MODI) improves the abnormal salinity distribution around the Changjiang river gate and its related SST reduces cold bias about 0.37˚C for July over the East Sea. Warm SST over this region is caused by barrier layer (BL). Freshwater flux and salinity changes can create a pronounced salinity-induced mixed layer (ML) above the top of the thermocline. The layer between the base of the ML and the top of the thermocline is called a barrier layer (BL), because it isolates the warm surface water from cold deep water. In addition, the improved fresh water forcing can lead to the change in the local volume transport from the Kuroshio to the Strait of Korea and Changed the transport and SST over the Straits of Korea have correlation 0.57 at 95% confidence level. For the

  20. The parasite community of gobiid fishes (Actinopterygii: Gobiidae) from the Lower Volga River region

    Czech Academy of Sciences Publication Activity Database

    Kvach, Yuriy; Boldyrev, V.; Lohner, R.; Stepien, C. A.

    2015-01-01

    Roč. 70, č. 7 (2015), s. 948-957 ISSN 0006-3088 Institutional support: RVO:68081766 Keywords : Gobiidae * parasites * Volga River * Caspian Sea * introduced species Subject RIV: EG - Zoology Impact factor: 0.719, year: 2015

  1. Regional Sediment Analysis of Mississippi River Sediment Transport and Hydrographic Survey Data

    National Research Council Canada - National Science Library

    Thorne, Colin

    2002-01-01

    The cumulative impacts of human occupation and development of watersheds, combined with engineering works on river channels have significantly disrupted the dynamic equilibrium of many stream systems and ecosystem...

  2. Environmental Assessment for the construction and operation of the Three Rivers Solid Waste Authority regional waste management center at the Savannah River Site

    International Nuclear Information System (INIS)

    1995-12-01

    This Environmental Assessment (EA) has been prepared by the US Department of Energy (DOE) to assess the potential environmental impacts associated with the construction and operation of a landfill and technology center for regionally-generated municipal solid waste at the Savannah River Site (SRS) near Aiken, South Carolina. The facility would serve the municipal solid waste disposal needs for SRS and at least nine of the surrounding counties who currently comprise the Three Rivers Solid Waste Authority (TRSWA). Additional counties could become included in the proposed action at some future date. Current Federal and state requirements do not afford individual counties and municipalities within the region encompassing SRS the ability to efficiently or economically operate modern waste management facilities. In addition, consolidation of regional municipal solid waste at one location would have the benefit of reducing the duplicity of environmental consequences associated with the construction and operation of county-level facilities. The option to seek a combined disposal and technology development facility based on a regionally-cooperative effort was selected as a viable alternative to the existing individual SRS or county disposal activities. This document was prepared in compliance with the National Environmental Policy Act (NEPA) of 1969, as amended, the requirements of the Council on Environmental Quality Regulations for Implementing NEPA (40 CFR Part 1021). NEPA requires the assessment of environmental consequences of Federal actions that may affect the quality of the human environment. Based on the potential for impacts described for impacts described herein, DOE will either publish a Finding of No Significant Impact or prepare an environmental impact statement (EIS)

  3. Light Absorption of Brown Carbon Aerosol in the Pearl River Delta Region of China

    Science.gov (United States)

    Huang, X.

    2015-12-01

    X.F. Huang, J.F. Yuan, L.M. Cao, J. Cui, C.N. Huang, Z.J. Lan and L.Y. He Key Laboratory for Urban Habitat Environmental Science and Technology, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, ChinaCorresponding author. Tel.: +86 755 26032532; fax: +86 755 26035332. E-mail address: huangxf@pku.edu.cn (X. F. Huang). Abstract: The strong spectral dependence of light absorption of brown carbon (BrC) aerosol has been recognized in recent decades. The Absorption Angstrom Exponent (AAE) of ambient aerosol was widely used in previous studies to attribute light absorption of brown carbon at shorter wavelengths, with a theoretical assumption that the AAE of black carbon (BC) aerosol equals to unit. In this study, the AAE method was improved by statistical extrapolation based on ambient measurements in the polluted seasons in typical urban and rural areas in the Pearl River Delta (PRD) region of China. A three-wavelength photoacoustic soot spectrometer (PASS-3) and an aerosol mass spectrometer (AMS) were used to explore the relationship between the ambient measured AAE and the ratio of organic aerosol to BC aerosol, in order to extract the more realistic AAE by pure BC aerosol, which were found to be 0.86, 0.82 and 1.02 at 405nm and 0.70, 0.71, and 0.86 at 532nm in the campaigns of urban-winter, urban-fall, and rural-fall, respectively. Roadway tunnel experiment results further supported the effectiveness of the obtained AAE for pure BC aerosol. In addition, biomass burning experiments proved higher spectral dependence of more-BrC environment and further verified the reliability of the instruments' response. Then, the average light absorption contribution of BrC aerosol was calculated to be 11.7, 6.3 and 12.1% (with total relative uncertainty of 7.5, 6.9 and 10.0%) at 405nm and 10.0, 4.1 and 5.5% (with total relative uncertainty of 6.5, 8.6 and 15.4%) at 532nm of the three campaigns, respectively. These results indicate that the

  4. The role of ants in minesite restoration in the Kakadu region of Australia's Northern Territory, with particular reference to their use as bioindicators. Supervising Scientist report 130

    International Nuclear Information System (INIS)

    Andersen, A.N.

    1998-01-01

    The goal of land rehabilitation following mining in environmentally sensitive areas is often ecosystem restoration, rather than simply revegetation. This is the case at Ranger uranium mine (RUM) in the Alligator Rivers Region of Australia's Northern Territory. Effective methods of monitoring ecological restoration are therefore required. Ants have frequently been used as indicators of restoration success following mining in northern Australia, but the extent to which ants actually provide a reliable indication of ecological change has been poorly documented. This study aimed, primarily, to investigate the degree to which ants provide an indication of the general status of ecosystems and, secondarily, to examine the direct role of ants in ecosystem restoration. The final outcome was the development of procedures for using ants as bioindicators of restoration success following mining in the Ranger uranium mine region

  5. Assessing regional climate simulations of the last 30 years (1982-2012) over Ganges-Brahmaputra-Meghna River Basin

    Science.gov (United States)

    Khandu; Awange, Joseph L.; Anyah, Richard; Kuhn, Michael; Fukuda, Yoichi

    2017-10-01

    The Ganges-Brahmaputra-Meghna (GBM) River Basin presents a spatially diverse hydrological regime due to it's complex topography and escalating demand for freshwater resources. This presents a big challenge in applying the current state-of-the-art regional climate models (RCMs) for climate change impact studies in the GBM River Basin. In this study, several RCM simulations generated by RegCM4.4 and PRECIS are assessed for their seasonal and interannual variations, onset/withdrawal of the Indian monsoon, and long-term trends in precipitation and temperature from 1982 to 2012. The results indicate that in general, RegCM4.4 and PRECIS simulations appear to reasonably reproduce the mean seasonal distribution of precipitation and temperature across the GBM River Basin, although the two RCMs are integrated over a different domain size. On average, the RegCM4.4 simulations overestimate monsoon precipitation by {˜ }26 and {˜ }5% in the Ganges and Brahmaputra-Meghna River Basin, respectively, while PRECIS simulations underestimate (overestimate) the same by {˜ }7% ({˜ }16%). Both RegCM4.4 and PRECIS simulations indicate an intense cold bias (up to 10° C) in the Himalayas, and are generally stronger in the RegCM4.4 simulations. Additionally, they tend to produce high precipitation between April and May in the Ganges (RegCM4.4 simulations) and Brahmaputra-Meghna (PRECIS simulations) River Basins, resulting in early onset of the Indian monsoon in the Ganges River Basin. PRECIS simulations exhibit a delayed monsoon withdrawal in the Brahmaputra-Meghna River Basin. Despite large spatial variations in onset and withdrawal periods across the GBM River Basin, the basin-averaged results agree reasonably well with the observed periods. Although global climate model (GCM) driven simulations are generally poor in representing the interannual variability of precipitation and winter temperature variations, they tend to agree well with observed precipitation anomalies when driven by

  6. Regional development of river basins in the Olkiluoto-Pyhaejaervi Area, SW Finland, 2000 BP - 8000 AP

    International Nuclear Information System (INIS)

    Ojala, A.E.K.; Virkki, H.; Palmu, J.-P.; Hokkanen, K.; Kaija, J.

    2006-12-01

    Biosphere assessment forms one of the main components in Posiva's Safety Case portfolio and includes analyses of terrain and ecosystem development. Shoreline displacement and changes in surface hydrology form one part of these analyses. In this report, the regional development of the Olkiluoto-Pyhaejaervi area in the time period 2000 BP - 8000 AP was examined by taking into account changes in the surface flow patterns of the Lapinjoki and Eurajoki river basins. A hydrological model, EULA, was developed and applied to investigate the past and future hydrological regimes and changes in the Olkiluoto-Pyhaejaervi study area. As detailed assessment of erosion and sedimentation effects were not within the scope of this study, only their general effects were evaluated. The digital elevation models (DEM) for different time stages (2000, 1500, 1000 and 500 BP; 100, 300, 500, 1000, 1500, 2000, 2500, 3000, 3500, 4000, 4500, 5000, 6000, 7000 and 8000 AP) were compiled taking into account the land uplift and tilting of the Earth's crust. With the aid of various sophisticated GIS tools, the boundaries of the main river basins, the flow patterns of rivers and development of lakes during each stage were modelled. The yearly discharge rates of rivers Eurajoki and Lapinjoki were also evaluated with the assumption that present climatic features prevail during the whole time period 2000 BP - 8000 AP. Finally, the probability of significant changes in the surface water flow routes were estimated during different stages. (orig.)

  7. Hydrodynamic analysis, performance assessment, and actuator design of a flexible tail propulsor in an artificial alligator

    International Nuclear Information System (INIS)

    Philen, Michael; Neu, Wayne

    2011-01-01

    The overall objective of this research is to develop analysis tools for determining actuator requirements and assessing viable actuator technology for design of a flexible tail propulsor in an artificial alligator. A simple hydrodynamic model that includes both reactive and resistive forces along the tail is proposed and the calculated mean thrust agrees well with conventional estimates of drag. Using the hydrodynamic model forces as an input, studies are performed for an alligator ranging in size from 1 cm to 2 m at swimming speeds of 0.3–1.8 body lengths per second containing five antagonistic pairs of actuators distributed along the length of the tail. Several smart materials are considered for the actuation system, and preliminary analysis results indicate that the acrylic electroactive polymer and the flexible matrix composite actuators are potential artificial muscle technologies for the system

  8. Plasma catecholamines and plasma corticosterone following restraint stress in juvenile alligators.

    Science.gov (United States)

    Lance, V A; Elsey, R M

    1999-05-01

    Ten juvenile alligators, mean body mass 793 g, hatched from artificially incubated eggs and raised under controlled conditions, were held out of water with their jaws held closed for 48 hr. An initial blood sample was taken and further samples collected at 1, 2, 4, 8, 24, and 48 hr. Epinephrine, norepinephrine, and dopamine were measured in plasma aliquots of 1.5 ml using high pressure liquid chromatography with electrochemical detection. Corticosterone was measured by radioimmunoassay. Plasma glucose was measured using the Trinder method and plasma calcium, cholesterol, and triglycerides were measured in an autoanalyzer. Epinephrine was about 4 ng/ml at the initial bleed, but declined steadily to blood cells showed changes indicating immune system suppression. By the end of the treatment the hetorophil/lymphocyte ratio increased to 4.7. These results suggest that handling alligators, taking multiple blood samples, and keeping them restrained for more than 8 hr is a severe stress to the animals.

  9. Pasvik River Watercourse, Barents Region: Pollution Impacts and Ecological Responses. Investigations in 1993

    Energy Technology Data Exchange (ETDEWEB)

    Traaen, T; Moiseenko, T; Sandimirov, S and others

    1994-12-31

    The Pasvik River is one of the largest rivers in the Northern Fennoscandia and constitutes the border between Norway and Russia, with catchment area in Finland, Norway and Russia. Besides being strongly regulated for hydroelectric power production, the river is polluted by the smelter in Nikel and other industrial activities and by domestic sewage from the settlements on both sides of the border. This document discusses the pollution of the river and the ecological responses. The two main areas of concern are heavy metals and eutrophication. Very high content of heavy metals in water, lake sediments, macrophytes and fish was found in Kuetsyarvi. Extensive toxic effects were documented on the fish population in the lake. The toxic effects are less than expected from the concentration of heavy metals, which is due to high calcium content, organic matter and eutrophication. Eutrophication is due to the domestic sewage from settlements within the water catchment. Kuetsyarvi has eutrophic status, the lower parts of the Pasvik River have oligo-mesotrophic status according to phosphorus concentrations, and the composition of the planktonic and benthic communities. Because of increased and stabilized water level from hydroelectric power regulations, increased abundance of macrophytes and zoobenthos in shallow areas also have occurred. 77 refs., 32 figs., 28 tabs.

  10. Numerical model to quantify biogenic volatile organic compound emissions: The Pearl River Delta region as a case study.

    Science.gov (United States)

    Wang, Xuemei; Situ, Shuping; Chen, Weihua; Zheng, Junyu; Guenther, Alex; Fan, Qi; Chang, Ming

    2016-08-01

    This article compiles the actual knowledge of the biogenic volatile organic compound (BVOC) emissions estimated using model methods in the Pearl River Delta (PRD) region, one of the most developed regions in China. The developed history of BVOC emission models is presented briefly and three typical emission models are introduced and compared. The results from local studies related to BVOC emissions have been summarized. Based on this analysis, it is recommended that local researchers conduct BVOC emission studies systematically, from the assessment of model inputs, to compiling regional emission inventories to quantifying the uncertainties and evaluating the model results. Beyond that, more basic researches should be conducted in the future to close the gaps in knowledge on BVOC emission mechanisms, to develop the emission models and to refine the inventory results. This paper can provide a perspective on these aspects in the broad field of research associated with BVOC emissions in the PRD region. Copyright © 2016. Published by Elsevier B.V.

  11. River terrace development in the NE Mediterranean region (Syria and Turkey): Patterns in relation to crustal type

    Science.gov (United States)

    Bridgland, David R.; Demir, Tuncer; Seyrek, Ali; Daoud, Mohamad; Abou Romieh, Mohammad; Westaway, Rob

    2017-06-01

    It is widely recognized that the optimal development of river terraces globally has been in the temperate latitudes, with NW and Central Europe being areas of particular importance for the preservation of such archives of Quaternary environmental change. There is also a growing consensus that the principal drivers of terrace formation have been climatic fluctuation against a background of progressive (but variable) uplift. Nonetheless river terraces are widely preserved in the Mediterranean region, where they have often been attributed to the effects of neotectonic activity, with a continuing debate about the relative significance of fluctuating temperature (glacials-interglacials) and precipitation (pluvials-interpluvials). Research in Syria and southern-central Turkey (specifically in the valleys of the Tigris and Ceyhan in Turkey, the Kebir in Syria and the trans-border rivers Orontes and Euphrates) has underlined the importance of uplift rates in dictating the preservation pattern of fluvial archives and has revealed different patterns that can be related to crustal type. The NE Mediterranean coastal region has experienced unusually rapid uplift in the Late Quaternary. The relation between the Kebir terraces and the staircase of interglacial raised beaches preserved along the Mediterranean coastline of NW Syria reinforces previous conclusions that the emplacement of the fluvial terrace deposits in the Mediterranean has occurred during colder climatic episodes.

  12. Groundwater conservation and monitoring activities in the middle Brenta River plain (Veneto Region, Northern Italy: preliminary results about aquifer recharge

    Directory of Open Access Journals (Sweden)

    Andrea Sottani

    2014-09-01

    Full Text Available In the middle Brenta River plain there is a unconfined aquifer that represents an important groundwater resource in Veneto region. In this area the main groundwater recharge factor is related to the stream seepage: the water dispersion from the Brenta river is active with variable intensity from the foothill to the alignment Nove di Bassano - Cartigliano (Province of Vicenza. In order to mitigate the expected groundwater effects, due to future important waterworks withdrawals provided by the regional water resources management plans, an experimental project of Managed Aquifer Recharge has started, by means of the realization of some river transversal ramps. The construction of pilot works, partially completed, were preceded by a specific hydrogeological monitoring program, aimed to the evaluation of the effectiveness of the MAR actions in terms of comparison between pre-and post-operam conditions. Thanks to the development of a site-specific methodology, aimed to the quantification of the artificial infiltration rate, and after some years of monitoring controls of the hydrological and hydrogeological regimes, it is now possible to evaluate the extent and the rate of the recharge effects in groundwater due to ramps realization. The monitoring plan will be continued in the medium-long term. Some innovative approaches, based for example on the use of groundwater temperature measurements as recharge tracer, will help to validate the preliminary results.

  13. Characterization of CDOM of river waters in China using fluorescence excitation-emission matrix and regional integration techniques

    Science.gov (United States)

    Zhao, Ying; Song, Kaishan; Shang, Yingxin; Shao, Tiantian; Wen, Zhidan; Lv, Lili

    2017-08-01

    The spatial characteristics of fluorescent dissolved organic matter (FDOM) components in river waters in China were first examined by excitation-emission matrix spectra and fluorescence regional integration (FRI) with the data collected during September to November between 2013 and 2015. One tyrosine-like (R1), one tryptophan-like (R2), one fulvic-like (R3), one microbial protein-like (R4), and one humic-like (R5) components have been identified by FRI method. Principal component analysis (PCA) was conducted to assess variations in the five FDOM components (FRί (ί = 1, 2, 3, 4, and 5)) and the humification index for all 194 river water samples. The average fluorescence intensities of the five fluorescent components and the total fluorescence intensities FSUM differed under spatial variation among the seven major river basins (Songhua, Liao, Hai, Yellow and Huai, Yangtze, Pearl, and Inflow Rivers) in China. When all the river water samples were pooled together, the fulvic-like FR3 and the humic-like FR5 showed a strong positive linear relationship (R2 = 0.90, n = 194), indicating that the two allochthonous FDOM components R3 and R5 may originate from similar sources. There is a moderate strong positive correlation between the tryptophan-like FR2 and the microbial protein-like FR4 (R2 = 0.71, n = 194), suggesting that parts of two autochthonous FDOM components R2 and R4 are likely from some common sources. However, the total allochthonous substance FR(3+5) and the total autochthonous substances FR(1+2+4) exhibited a weak correlation (R2 = 0.40, n = 194). Significant positive linear relationships between FR3 (R2 = 0.69, n = 194), FR5 (R2 = 0.79, n = 194), and chromophoric DOM (CDOM) absorption coefficient a(254) were observed, which demonstrated that the CDOM absorption was dominated by the allochthonous FDOM components R3 and R5.

  14. [Emission factors and PM chemical composition study of biomass burning in the Yangtze River Delta region].

    Science.gov (United States)

    Tang, Xi-Bin; Huang, Cheng; Lou, Sheng-Rong; Qiao, Li-Ping; Wang, Hong-Li; Zhou, Min; Chen, Ming-hua; Chen, Chang-Hong; Wang, Qian; Li, Gui-Ling; Li, Li; Huang, Hai-Ying; Zhang, Gang-Feng

    2014-05-01

    The emission characteristics of five typical crops, including wheat straw, rice straw, oil rape straw, soybean straw and fuel wood, were investigated to explore the gas and particulates emission of typical biomass burning in Yangzi-River-Delta area. The straws were tested both by burning in stove and by burning in the farm with a self-developed measurement system as open burning sources. Both gas and fine particle pollutants were measured in this study as well as the chemical composition of fine particles. The results showed that the average emission factors of CO, NO, and PM2,5 in open farm burning were 28.7 g.kg -1, 1.2 g.kg-1 and 2.65 g kg-1 , respectively. Due to insufficient burning in the low oxygen level environment, the emission factors of stove burning were higher than those of open farm burning, which were 81.9 g kg-1, 2. 1 g.kg -1 and 8.5 gkg -1 , respectively. Oil rape straw had the highest emission factors in all tested straws samples. Carbonaceous matter, including organic carbon(OC) and element carbon(EC) , was the foremost component of PM2, 5from biomass burning. The average mass fractions of OC and EC were (38.92 +/- 13.93)% and (5.66 +/-1.54)% by open farm burning and (26.37 +/- 10. 14)% and (18.97 +/- 10.76)% by stove burning. Water soluble ions such as Cl-and K+ had a large contribution. The average mass fractions of CI- and K+ were (13.27 +/-6. 82)% and (12.41 +/- 3.02)% by open farm burning, and were (16.25 +/- 9.34)% and (13.62 +/- 7.91)% by stove burning. The K +/OC values of particles from wheat straw, rice straw, oil rape straw and soybean straw by open farm burning were 0. 30, 0. 52, 0. 49 and 0. 15, respectively, which can be used to evaluate the influence on the regional air quality in YRD area from biomass burning and provide direct evidence for source apportionment.

  15. 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).

  16. Uranium budget of the Thames River, Ontario, Great Lakes Region: partitioning between dissolved and microorganism components

    International Nuclear Information System (INIS)

    Mann, H.; Fyfe, W.S.

    1987-01-01

    The average level of dissolved U in the Thames River of southern Ontario is 1.45 ± 0.61 ppb, representing about twice the global mean riverine U solute concentration of 0.6 ppb. Systematic seasonal variations of dissolved U occur, peaking over the fall and winter months September-February, contrasting with depressed levels during the spring and summer: the winter and fall peaks correlate with higher discharge rates during thawing and rainfall maxima respectively, and the peak during thawing is probably indigenous to a transient melt-water surge. Whereas variations in discharge rate of up to 100-fold occur over a year, the magnitude of differences in aqueous U are at most a factor of 2, such that the U supply to the river is over-compensated for by extra water in the river system. Algae are abundant in Thames River waters at all seasons, constituting a significant fraction of the suspended > 0.45-μm particulates: they have enhanced U contents of 10 3 -10 5 times that of the river water, and an average of 28,000 ppb U. The average weight of suspended algae in river water is 9.7 mg l -1 (± 6.6 1σ), and these microorganisms carry ∼ 15% of the total riverine U flux. A correlation exists between levels of dissolved U and the U abundance of suspended algae, implying a relatively uniform partitioning of U between algae and water of 2x10 4 . 13 refs.; 7 figs.; 2 tabs

  17. Cross-scale intercomparison of climate change impacts simulated by regional and global hydrological models in eleven large river basins

    Energy Technology Data Exchange (ETDEWEB)

    Hattermann, F. F.; Krysanova, V.; Gosling, S. N.; Dankers, R.; Daggupati, P.; Donnelly, C.; Flörke, M.; Huang, S.; Motovilov, Y.; Buda, S.; Yang, T.; Müller, C.; Leng, G.; Tang, Q.; Portmann, F. T.; Hagemann, S.; Gerten, D.; Wada, Y.; Masaki, Y.; Alemayehu, T.; Satoh, Y.; Samaniego, L.

    2017-01-04

    Ideally, the results from models operating at different scales should agree in trend direction and magnitude of impacts under climate change. However, this implies that the sensitivity of impact models designed for either scale to climate variability and change is comparable. In this study, we compare hydrological changes simulated by 9 global and 9 regional hydrological models (HM) for 11 large river basins in all continents under reference and scenario conditions. The foci are on model validation runs, sensitivity of annual discharge to climate variability in the reference period, and sensitivity of the long-term average monthly seasonal dynamics to climate change. One major result is that the global models, mostly not calibrated against observations, often show a considerable bias in mean monthly discharge, whereas regional models show a much better reproduction of reference conditions. However, the sensitivity of two HM ensembles to climate variability is in general similar. The simulated climate change impacts in terms of long-term average monthly dynamics evaluated for HM ensemble medians and spreads show that the medians are to a certain extent comparable in some cases with distinct differences in others, and the spreads related to global models are mostly notably larger. Summarizing, this implies that global HMs are useful tools when looking at large-scale impacts of climate change and variability, but whenever impacts for a specific river basin or region are of interest, e.g. for complex water management applications, the regional-scale models validated against observed discharge should be used.

  18. Divergent Developmental Trajectories and Strategic Coupling in the Pearl River Delta: Where Is a Sustainable Way of Regional Economic Growth?

    Directory of Open Access Journals (Sweden)

    Yi Liu

    2017-10-01

    Full Text Available This paper interprets regional economic sustainability in the context of the globalization of late-coming regions. Drawing upon the concept of strategic coupling from economic geography, this paper proposes two types of strategic coupling, captive and proactive coupling, for better understanding regional sustainability and resilience through the experiences of the Pearl River Delta in China. It finds that sub-regional economies under captive coupling become highly dependent on exogenous growth and are vulnerable to external shocks. This trajectory looks less sustainable according to the general understanding, but it interestingly shows better resilience during and after the 2008 global financial crisis. In contrast, the ones under proactive coupling are less volatile, but growing much slower and are less resilient. By reporting these regional economic dynamics, this paper argues that sustainability in late-coming regions cannot be explained by either intra-regional forces or the means of global integration alone. In contrast, it has to be explained by the combination of both; the alleged strategic coupling in which economic growth and learning happens. This paper thus calls for greater attention to strategic coupling, the trade-off of globalization and resilience for understanding regional sustainability, rather than purely focusing on resource utilization and ecological balance.

  19. Concordance between macrophytes and macroinvertebrates in a Mediterranean river of central Apennine region.

    Science.gov (United States)

    Traversetti, Lorenzo; Scalici, Massimiliano; Ginepri, Valeria; Manfrin, Alessandro; Ceschin, Simona

    2014-05-01

    The main aim of this study was to improve the knowledge about the concordance among macrophytes and macroinvertebrates to provide complementary information and facilitate the procedures for quality assessment of river ecosystems. Macrophytes and macroinvertebrates were collected in 11 sampling sites along a central Apennine calcareous river in October 2008 and June 2009. The concordance between the two biomonitoring groups was tested according to several environmental parameters. The comparison of data matrix similarities by Mantel test showed differences in the assemblage of macrophytes and macroinvertebrates along the river since correlation values were 0.04, p > 0.05 in October 2008 and 0.39, p > 0.05 in June 2009. The study revealed lack of concordance between the two groups, emphasizing that the information provided by macrophytes and macroinvertebrates does not overlap in terms of response to environmental parameters. Indeed, the two different biological groups resulted useful descriptors of different parameters. Together, they could represent a complementary tool to reflect the river environmental quality.

  20. River water quality in the northern sugarcane-producing regions of ...

    African Journals Online (AJOL)

    Sugarcane is the major irrigated crop with regards to area cultivated in the Crocodile, Komati-Lomati and Pongola River catchments. Increasing demand for and use of water resources in these catchments has led to concerns about deterioration in water quality. In this study, chemical water quality data obtained from the ...

  1. Variation in Nest Temperatures of the American Alligator Found on the Kennedy Space Center Merritt Island National Wildlife Refuge

    Science.gov (United States)

    Lowers, Russell; Guillette, Louis J.; Weiss, Stephanie

    2016-01-01

    Information on nest temperatures of the American Alligator (Alligator mississippiensis) constructed in the wild is limited. Nesting temperatures during a critical thermal sensitive period determine the sex of alligators and are therefore critical in establishing the sex biases in recruitment efforts of alligators within a given community. Nest components, varying environmental conditions, and global warming could have a significant impact on nest temperatures, thus affecting future generations of a given population. One hundred and seventy four programmable thermistors were inserted into fifty eight nests from 2010 through 2015 nesting cycles. Three thermistors were placed inside each nest cavity (one on top of the eggs, one in the middle of the eggs, and one at the bottom of the clutch of the eggs) to collect temperature profiles in the incubation chamber and throughout the entire incubation period. One thermistor was also placed near or above these nests to obtain an ambient air temperature profile. Once retrieved, data from these thermistors were downloaded to examine temperature profiles throughout the incubation period as well as during the period of sexual determination. These data would help establish survival rates related to nest temperature and predict sex ratio of recruited neonates at the Kennedy Space Center. Over three million temperatures have been recorded since 2010 for the alligator thermistor study giving us insight to the recruitment efforts found here. Precipitation was the largest influence on nesting temperatures outside of daily photoperiod, with immediate changes of up to eight degrees Celsius.

  2. Regional and Household Adaptation Strategies to Climate Extremes: the Case Study of the Beava River Basin, the Czech Republic

    Science.gov (United States)

    Duží, Barbora; Stojanov, Robert; Vikhrov, Dmytro

    2013-04-01

    We investigate regional and household adaptation strategies in the region affected by climate extremes, focusing on floods occurrence during past 15 years period. The main research question is: What is the overall state of adaptation measurements to climate extremes on the Bečva river basin? Target area is located along upper and middle part of the Bečva river basin in the east of the Czech Republic. The main theoretical concepts draw from differentiations between coping/adaptation strategies to climate extremes and theory of focusing event as a starter of changes in attention and agenda of problem solution. We apply mixed empirical research and case study approach. First we use qualitative research to serve as an initial entrance to the issue, to find out the perception of adaptation progress and preparedness to climate extremes on regional level. We conducted deep interviews (N=20) with relevant stakeholders. We proceed with quantitative research through the conducting face-to face questionnaires with household residents (N=305) in no, low and no risk area in relation to flood occurrence. We designed set of questions to find out relation among experiences with flood, the level of damages and applied emergency and adaptation measurements.

  3. Spatio-temporal variation of precipitation in the Three-River Headwater Region from 1961 to 2010

    Institute of Scientific and Technical Information of China (English)

    YI Xiangsheng; LI Guosheng; YIN Yanyu

    2013-01-01

    Based on a monthly dataset of precipitation time series (1961-2010) from 12 meteorological stations across the Three-River Headwater Region (THRHR) of Qinghai Province,China,the spatio-temporal variation and abrupt change analysis of precipitation were examined by using moving average,linear regression,spline interpolation,the Mann-Kendall test and so on.Major conclusions were as follows.(1) The long-term annual and seasonal precipitation in the study area indicated an increasing trend with some oscillations during 1961-2010; however,the summer precipitation in the Lantsang (Lancang) River Headwater Region (LARHR),and the autumn precipitation in the Yangtze River Headwater Region (YERHR) of the THRHR decreased in the same period.(2) The amount of annual precipitation in the THRHR and its three sub-headwater regions was greater in the 1980s and 2000s.The springs were fairly wet after the 1970s,while the summers were relatively wet in the 1960s,1980s and 2000s.In addition,the amount of precipitation in the autumn was greater in the 1970s and 1980s,but it was relatively less for the winter precipitation,except in the 1990s.(3) The normal values of spring,summer,winter and annual precipitation in the THRHR and its three sub-headwater regions all increased,but the normal value of summer precipitation in the LARHR had a negative trend and the normal value of winter precipitation declined in general.(4) The spring and winter precipitation increased in most of the THRHR.The summer,autumn and annual precipitation increased mainly in the marginal area of the west and north and decreased in the regions of Yushu,Zaduo,Jiuzhi and Banma.(5) The spring and winter precipitation in the THRHR and its three sub-headwater regions showed an abrupt change,except for the spring precipitation in the YARHR.The abrupt changes of spring precipitation were mainly in the late 1980s and early 1990s,while the abrupt changes of winter precipitation were primary in the mid-to late 1970s

  4. Tropospheric aerosols radiation feedback on the climate of Pearl River Delta Region using an air quality model

    Science.gov (United States)

    Nduka, I. C.

    2016-12-01

    The Pearl River Delta (PRD) region, one of the most vibrant economic regions in China has been witnessing rapid population, economic and structural growth and development. It is also one of the regions mostly polluted with trace gases and particulates. Recent reviews show large uncertainties in climate modification studies, indicating the need for further investigations, such as the role of tropospheric aerosols on direct and indirect climate modification. The aim of this research is to appraise the impacts of tropospheric aerosols on the climate of PRD region. An integrated air quality downscale meteorology and air quality from regional scale (27km) to local scale (3km). The model will be evaluated for both meteorology and air quality by comparing model results with measurements. The radiative forcing of tropospheric aerosols will also be determined so as to estimate the feedbacks and impacts on the climate. This research, when completed, is expected to improve our understanding of tropospheric aerosol-cloud thermodynamic interactions at regional and local scales, thus enhancing our knowledge of the regional and local climate system, which is anticipated to provide critical references for formulating sustainable environment and air quality policies.

  5. Modeling of Regionalized Emissions (MoRE into Water Bodies: An Open-Source River Basin Management System

    Directory of Open Access Journals (Sweden)

    Stephan Fuchs

    2017-03-01

    Full Text Available An accurate budget of substance emissions is fundamental for protecting freshwater resources. In this context, the European Union asks all member states to report an emission inventory of substances for river basins. The river basin management system MoRE (Modeling of Regionalized Emissions was developed as a flexible open-source instrument which is able to model pathway-specific emissions and river loads on a catchment scale. As the reporting tool for the Federal Republic of Germany, MoRE is used to model annual emissions of nutrients, heavy metals, micropollutants like polycyclic aromatic hydrocarbons (PAH, Bis(2-ethylhexylphthalate (DEHP, and certain pharmaceuticals. Observed loads at gauging stations are used to validate the calculated emissions. In addition to its balancing capabilities, MoRE can consider different variants of input data and quantification approaches, in order to improve the robustness of different modeling approaches and to evaluate the quality of different input data. No programming skills are required to set up and run the model. Due to its flexible modeling base, the effect of reduction measures can be assessed. Within strategic planning processes, this is relevant for the allocation of investments or the implementation of specific measures to reduce the overall pollutant emissions into surface water bodies and therefore to meet the requirements of water policy.

  6. Agro-extractivist value chains and regional development: the case of the Lower Tocantins River in the Brazilian Amazon

    OpenAIRE

    Dürr, Jochen

    2014-01-01

    The Lower Tocantins river region offers a wide range of agricultural and extractive products like açaí palm fruits, pepper, oil palms and manioc, which are produced for local and national consumption and for exports. These products do not only generate value added in the agricultural sector, but also indirectly in other sectors like agro-industry and commerce. The value chains of agricultural and extractive products form the basis of the rural economy and hence for the development of the nine...

  7. Parasitism of the isopod Artystone trysibia in the fish Chaetostoma dermorhynchum from the Tena River (Amazonian region, Ecuador).

    Science.gov (United States)

    Junoy, Juan

    2016-01-01

    The isopod Artystone trysibia Schioedte, 1866 is described by using a collection of specimens that were found parasitizing loricariid fish Chaetostoma dermorhynchum Boulenger, 1887 in the Tena River (Napo province, Ecuador, Amazonian region). Additionally to freshly collected specimens, complementary data of the parasite was obtained from preserved fishes at Ecuadorian museums. This is the first record of A. trysibia in Ecuador, and the most upstream location for the species. The new host fish, Chaetostoma dermorhynchum, is used locally as food. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Heterophil/Lymphocyte Alterations as a Measure of Stress in American Alligators in Relation to Anthropogenic Disturbance in a Louisiana Intermediate Marsh

    Directory of Open Access Journals (Sweden)

    Christopher M. Murray

    2015-05-01

    Full Text Available Numerous anthropogenic factors represent environmental threats to Gulf Coast wetland ecosystems and associated fauna. American alligators (Alligator mississippiensis have been subject to long-term management and used as ecological and physiological indicators of habitat quality in response to anthropogenic events and stochastic natural disasters. The present study monitored heterophil to lymphocyte ratios (an indicator of stress, in American alligators in a Louisiana intermediate marsh from 2009 to 2011, a time period that coincides with an oil inundation event that occurred in 2011. Sixteen alligators were observed and processed morphometrically (total length, snout-vent length and body mass. Heterophil to lymphocyte ratios were negatively correlated with size, suggesting larger American alligators were physiologically more resilient to the disturbance, more able to actively avoid these poor conditions, or are less affected by localized disturbance.

  9. Multi-scale response of runoff to climate fluctuation in the headwater region of Kaidu River in Xinjiang of China

    Science.gov (United States)

    Bai, Ling; Chen, Zhongsheng; Xu, Jianhua; Li, Weihong

    2016-08-01

    Based on the hydrological and meteorological data in the headwater region of the Kaidu River during 1960-2009, the multi-scale characteristics of runoff variability were analyzed using the ensemble empirical mode decomposition method (EEMD), and the aim is to investigate the oscillation mode structure characteristics of runoff change and its response to climate fluctuation at different time scales. Results indicated that in the past 50 years, the overall runoff of Kaidu River in Xinjiang has showed a significant nonlinear upward trend, and its changes have obviously exhibited an inter-annual scale (quasi-3 and quasi-6-year) and inter-decadal scale (quasi-10 and quasi-25-year). Variance contribution rates of each component manifested that the inter-decadal change had been playing a more important role in the overall runoff change for Kaidu River, and the reconstructed inter-annual variation trend could describe the fluctuation state of the original runoff anomaly during the study period. The reconstructed inter-decadal variability effectively revealed that the runoff for Kaidu River changed over the years, namely the states of abundance and low water period appear alternately. In addition, we found that runoff has a positive correlation to precipitation and temperature at different time scales, but they are most significant and relevant at inter-decadal scale, indicating the inter-decadal scale is most suitable for investigating the responses of runoff dynamics to climate fluctuation. At the same time, the results also suggested that EEMD is an effective method to analyze the multi-scale characteristics of nonlinear and non-stationary signal.

  10. Effect of ecological restoration and climate change on ecosystems: a case study in the Three-Rivers Headwater Region, China.

    Science.gov (United States)

    Jiang, Chong; Zhang, Linbo

    2016-06-01

    The Three-Rivers Headwater Region (TRHR) is the headwater of the Yangtze River Basin (YARB), Yellow River Basin (YRB), and Lancang River Basin (LRB); it is known as China's 'Water Tower' owing to its important supply of freshwater. In order to assess ecosystem changes in the TRHR during 2000-2012, we systematically and comprehensively evaluated a combination of model simulation results and actual observational data. The results showed the following: (1) Ecosystem pattern was relatively stable during 2000-2010, with a slight decrease in farmland and desert areas, and a slight increase in grassland and wetland/water-body areas. (2) A warmer and wetter climate, and ecological engineering, caused the vegetation cover and productivity to significantly improve. (3) Precipitation was the main controlling factor for streamflow. A significant increase in precipitation during 2000-2012 resulted in an obvious increase in annual and seasonal streamflow. Glacier melting also contributed to the streamflow increase. (4) The total amount of soil conservation increased slightly from 2000 to 2012. The increase in precipitation caused rainfall erosivity to increase, which enhanced the intensity of soil erosion. The decrease in wind speed decreased wind erosion and the frequency of sandstorms. (5) The overall habitat quality in the TRHR was stable between 2000 and 2010, and the spatial pattern exhibited obvious heterogeneity. In some counties that included nature reserves, habitat quality was slightly higher in 2010 than in 2000, which reflected the effectiveness of the ecological restoration. Overall, the aforementioned ecosystem changes are the combined results of ecological restoration and climate change, and they are likely a local and temporary improvement, rather than a comprehensive and fundamental change. Therefore, more investments and efforts are needed to preserve natural ecosystems.

  11. Spatial and temporal variability in the Quality of Surface water in a semi-arid mediterranean region (river orontes- Lebanon)

    International Nuclear Information System (INIS)

    SLIM, K.; SAAD, Z.; KAZPARD, V.; EL SAMAD, O.; NASREDDINE, M.

    2004-01-01

    The Orontes River is an international river, with its headwaters in Lebanon, its middle section in Syria and its mouth in Turkey. Fresh surface waters were sampled monthly during the year 2000 and analyzed for major ions and for trace metals. Sea-salt aerosols in rainwater partially influence the major ion composition in the river. The concentration of major cations and anions fall within the range of the most common natural Concentration of major ion assemblages established for world river(MCNC), with a cation and anion dominance in the order of Ca > Mg > Na> K and HCO3 > SO4 > Cl, which tend to be predominantly influenced by chemical weathering of rocks and minerals in a semi-arid region. Ca and HCO3 are mostly derived from the dissolution of carbonate rocks. The sources of SO4 could be attributed to anhydrite minerals and to anthropogenic impact from fertilizers. Increases in nutrient concentrations are attributed mainly to the increasing influence of agricultural runoff. δ18 0/ δH plots shows that the data either fits the Mediterranean Meteoric Water Line(MMWL) or have elevated values that indicate evaporative isotope enrichment in a semi-arid climate. The correlation matrix for trace elements shows a high coefficient of correlation for Fe, Zn and Cu indicating that these elements could be controlled by the same chemistry in water. The bicarbonate-alkaline type of Orontes surface water contribute to the formation of trace metals-carbonate complexes such as FeCO3(aq) and ZnCO3 (aq). The good correlation between Pb, Cd and Cr reflects the effect of increasing urbanization in the catchments. (author)

  12. Isotope hydrology study of Kalamos region (Attiki) and of the Assopos river basin

    International Nuclear Information System (INIS)

    Leontiadis, J.L.

    1980-10-01

    The isotopic composition of the water was used to determine the mechanism of recharge of the Assopos river basin and that of the Kalamos springs issuing brackish water near the coast. The results of the study permitted the catchment of the water before its salinization. A quantity of 73000 m 3 per day is now pumped and used as additional drinkable water for the major area of Athens covering about the 1/6 of the corresponding mean daily consumption. (T.A.)

  13. Alligator Rivers Analogue project. Geochemistry of 239Pu, 129I, 99Tc and 36Cl

    International Nuclear Information System (INIS)

    Fabryka-Martin, J.T.; Curtis, D.B.

    1992-01-01

    One objective of this research programme has been to evaluate the applicability of uranium orebodies as natural analogues for testing radionuclide release-rate models used in performance assessment activities. The investigated nuclides included three of the most persistent radioactive constituents of high-level wastes from nuclear fission power reactors: plutonium-239, iodine-129, and technetium-99. The feasibility of uranium minerals as analogues for the behavior of these nuclear reaction products (NRP) in spent fuel relies upon a capability to characterise NRP concentrations in the source minerals. Measured abundances of natural 239 Pu, 99 Tc and 129 I in uranium ores are compared to calculated abundances in order to evaluate the degree to retention of these radionuclides by the ore. This modelling study also shows the extent to which various NRP are correlated, such that one provides a constraint on the production rates of others. Under most conditions, 36 Cl, another long-lived neutron-capture product found in uranium ores, is shown to be an ideal in-situ monitor of the 235 U fission rate, which is the dominant source term for 129 I and possibly a significant one for 99 Tc. Similarly, 239 Pu/U ratios can be used to establish limits on the 238 U neutron-induced fission rate; the ratios measured in this study suggest that 238 U induced fission comprises 129 I and 99 Tc. 79 refs., 21 tabs., 18 figs

  14. Alligator Rivers Analogue project. Geochemical modelling of secondary uranium ore formation. Final Report - Volume 11

    International Nuclear Information System (INIS)

    Sverjensky, D.; Bennett, D.G.; Read, D.

    1992-01-01

    The purpose of the present study was to establish how the uranyl phosphate zone at the Koongarra site was formed. The overall approach taken in the present study employed theoretical chemical mass transfer calculations and models that permit investigation and reconstruction of the kinds of waters that could produce the uranyl phosphate zone. These calculations have used the geological and mineralogical data for the Koongarra weathered zone (Volumes 2, 8, and 9 of this series), to constrain the initial compositions and reactions undergone by groundwater during the formation of the uranyl phosphate zone. In carrying out these calculations the present-day analyses of Koongarra waters are used only as a guide to the possible initial composition of the fluids associated with the formation of the phosphate zone. Aqueous speciation, saturation state and chemical mass transfer calculations were carried out using the computer programs EQ3NR and EQ6 (Wolery, 1983; Wolery et al., 1984) and a thermodynamic database generated at The Johns Hopkins University over the last eight years which is tabulated in the Appendix 1 to Volume 12 of this series. Despite uncertainties in the thermodynamic characterisation of species, all the above calculations suggest that the uranyl phosphate zone at Koongarra has not formed from present-day groundwaters (Volume 12 of this series). The present-day groundwaters in the weathered zone (eg. at 13 m depth) appear to be undersaturated with respect to saleeite. Furthermore, as present-day groundwaters descend below the water table they rapidly lose their atmospheric oxygen imprint, as is typical of most groundwaters, and become even more reducing in character. Under these circumstances, the groundwaters become more undersaturated with respect to saleeite than the shallow groundwaters. Because much of the phosphate zone is currently below the water table, under saturated zone conditions, it is suggested in the present study that the uranyl phosphate zone must have formed in the geologic past under unsaturated zone conditions

  15. Alligator Rivers Analogue project. Geochemical modelling of secondary uranium ore formation. Final Report - Volume 11

    Energy Technology Data Exchange (ETDEWEB)

    Sverjensky, D [The John Hopkins Univ, Dept of Earth and Planetary Sciences, Baltimore (United States); Bennett, D G; Read, D [W.S. Atkins Science and Technology, Epsom Surrey, (United Kingdom)

    1993-12-31

    The purpose of the present study was to establish how the uranyl phosphate zone at the Koongarra site was formed. The overall approach taken in the present study employed theoretical chemical mass transfer calculations and models that permit investigation and reconstruction of the kinds of waters that could produce the uranyl phosphate zone. These calculations have used the geological and mineralogical data for the Koongarra weathered zone (Volumes 2, 8, and 9 of this series), to constrain the initial compositions and reactions undergone by groundwater during the formation of the uranyl phosphate zone. In carrying out these calculations the present-day analyses of Koongarra waters are used only as a guide to the possible initial composition of the fluids associated with the formation of the phosphate zone. Aqueous speciation, saturation state and chemical mass transfer calculations were carried out using the computer programs EQ3NR and EQ6 (Wolery, 1983; Wolery et al., 1984) and a thermodynamic database generated at The Johns Hopkins University over the last eight years which is tabulated in the Appendix 1 to Volume 12 of this series. Despite uncertainties in the thermodynamic characterisation of species, all the above calculations suggest that the uranyl phosphate zone at Koongarra has not formed from present-day groundwaters (Volume 12 of this series). The present-day groundwaters in the weathered zone (eg. at 13 m depth) appear to be undersaturated with respect to saleeite. Furthermore, as present-day groundwaters descend below the water table they rapidly lose their atmospheric oxygen imprint, as is typical of most groundwaters, and become even more reducing in character. Under these circumstances, the groundwaters become more undersaturated with respect to saleeite than the shallow groundwaters. Because much of the phosphate zone is currently below the water table, under saturated zone conditions, it is suggested in the present study that the uranyl phosphate zone must have formed in the geologic past under unsaturated zone conditions

  16. Alligator Rivers Analogue project. Geochemical modelling of secondary uranium ore formation. Final Report - Volume 11

    Energy Technology Data Exchange (ETDEWEB)

    Sverjensky, D. [The John Hopkins Univ, Dept of Earth and Planetary Sciences, Baltimore (United States); Bennett, D.G.; Read, D. [W.S. Atkins Science and Technology, Epsom Surrey, (United Kingdom)

    1992-12-31

    The purpose of the present study was to establish how the uranyl phosphate zone at the Koongarra site was formed. The overall approach taken in the present study employed theoretical chemical mass transfer calculations and models that permit investigation and reconstruction of the kinds of waters that could produce the uranyl phosphate zone. These calculations have used the geological and mineralogical data for the Koongarra weathered zone (Volumes 2, 8, and 9 of this series), to constrain the initial compositions and reactions undergone by groundwater during the formation of the uranyl phosphate zone. In carrying out these calculations the present-day analyses of Koongarra waters are used only as a guide to the possible initial composition of the fluids associated with the formation of the phosphate zone. Aqueous speciation, saturation state and chemical mass transfer calculations were carried out using the computer programs EQ3NR and EQ6 (Wolery, 1983; Wolery et al., 1984) and a thermodynamic database generated at The Johns Hopkins University over the last eight years which is tabulated in the Appendix 1 to Volume 12 of this series. Despite uncertainties in the thermodynamic characterisation of species, all the above calculations suggest that the uranyl phosphate zone at Koongarra has not formed from present-day groundwaters (Volume 12 of this series). The present-day groundwaters in the weathered zone (eg. at 13 m depth) appear to be undersaturated with respect to saleeite. Furthermore, as present-day groundwaters descend below the water table they rapidly lose their atmospheric oxygen imprint, as is typical of most groundwaters, and become even more reducing in character. Under these circumstances, the groundwaters become more undersaturated with respect to saleeite than the shallow groundwaters. Because much of the phosphate zone is currently below the water table, under saturated zone conditions, it is suggested in the present study that the uranyl phosphate zone must have formed in the geologic past under unsaturated zone conditions

  17. Alligator Rivers Analogue project. Weathering and its effects on uranium redistribution

    International Nuclear Information System (INIS)

    Isobe, H.; Ohnuki, T.; Yanase, N.; Sato, T.; Kimura, H.; Sekine, K.; Nagano, T.; Klessa, D.A.; Conoley, C.; Nakashima, S.; Ewing, R.C.

    1992-01-01

    In the vicinity of the uranium ore deposit at Koongarra, quartz-chlorite schist, the ore host rock, has been subjected to weathering. Although quartz is resistant to weathering, chlorite has been altered to clays and iron minerals. The chlorite weathering and the uranium association with the weathered minerals are the main topics of this study. In order to clarify the weathering of chlorite and its effects on the redistribution of uranium, the processes, mechanisms, and kinetics of the chlorite weathering, and the uranium concentrations in minerals were examined by various methods: X-ray diffraction analysis, scanning electron microscopy, electron microprobe analysis, transmission electron microscopy, autoradiography, visible spectroscopy, alpha and gamma spectrometry. The observed results were compared to those calculated, based on two different models developed for the present study. Water-rock interactions have resulted in the weathering of chlorite and precipitation and sorption of uranyl from the groundwaters with the weathering products. It is concluded that the chlorite weathering affects the uranium retardation factor, and thus uranium redistribution at Koongarra. 55 refs., 20 tabs., 120 figs

  18. Alligator Rivers Analogue project. Geochemical modelling of present-day groundwaters. Final Report - Volume 12

    Energy Technology Data Exchange (ETDEWEB)

    Sverjensky, D A [The John Hopkins Univ, Dept of Earth and Planetary Sciences, Baltimore (United States)

    1993-12-31

    The main purpose of this report is to summarize geochemical modeling studies of the present-day Koongarra groundwaters. Information on the present-day geochemistry and geochemical processes at Koongarra forms a basis for a present-day analogue for nuclear waste migration. The present-day analogue is built on studies of the mineralogy and petrology of the Koongarra deposit, and chemical analyses of present-day groundwaters from the deposit. The overall approach taken in the present study has been to carry out a series of aqueous speciation and state of saturation calculations, including chemical mass transfer calculations, to address the possible control over the chemistry of the present-day for the groundwaters at Koongarra. The most important implication of the present study for the migration of radionuclides is the strong role played by the water-rock interactions, both above and below the water table, influencing the overall chemical evolution of the groundwaters. Thus, the results show that the chemical evolution of waters is strongly controlled by the initial availability of CO{sub 2} and the mineral assemblage encountered, which together determine the major element evolution of the waters by controlling the pH. The relative rates of evolution of the pH and the oxidation state of the groundwaters are also critical to the mobility of uranium. The shallow Koongarra waters are sufficiently oxidising that they can dissolve and transport uranium even under acidic conditions. Under the more reducing condition of the deep groundwaters, is the pH level that permits uranium transport as carbonate complexes. However, if the oxidation state decreases to much lower levels, it would be expected that uranium become immobile. All the speciation and state of saturation calculations carried out in the present study are available from the author, on request 22 refs., 7 tabs., 18 figs.

  19. Alligator Rivers Analogue project. Geochemical modelling of present-day groundwaters. Final Report - Volume 12

    Energy Technology Data Exchange (ETDEWEB)

    Sverjensky, D. A. [The John Hopkins Univ, Dept of Earth and Planetary Sciences, Baltimore (United States)

    1992-12-31

    The main purpose of this report is to summarize geochemical modeling studies of the present-day Koongarra groundwaters. Information on the present-day geochemistry and geochemical processes at Koongarra forms a basis for a present-day analogue for nuclear waste migration. The present-day analogue is built on studies of the mineralogy and petrology of the Koongarra deposit, and chemical analyses of present-day groundwaters from the deposit. The overall approach taken in the present study has been to carry out a series of aqueous speciation and state of saturation calculations, including chemical mass transfer calculations, to address the possible control over the chemistry of the present-day for the groundwaters at Koongarra. The most important implication of the present study for the migration of radionuclides is the strong role played by the water-rock interactions, both above and below the water table, influencing the overall chemical evolution of the groundwaters. Thus, the results show that the chemical evolution of waters is strongly controlled by the initial availability of CO{sub 2} and the mineral assemblage encountered, which together determine the major element evolution of the waters by controlling the pH. The relative rates of evolution of the pH and the oxidation state of the groundwaters are also critical to the mobility of uranium. The shallow Koongarra waters are sufficiently oxidising that they can dissolve and transport uranium even under acidic conditions. Under the more reducing condition of the deep groundwaters, is the pH level that permits uranium transport as carbonate complexes. However, if the oxidation state decreases to much lower levels, it would be expected that uranium become immobile. All the speciation and state of saturation calculations carried out in the present study are available from the author, on request 22 refs., 7 tabs., 18 figs.

  20. Development and application of a novel method for regional assessment of groundwater contamination risk in the Songhua River Basin.

    Science.gov (United States)

    Nixdorf, Erik; Sun, Yuanyuan; Lin, Mao; Kolditz, Olaf

    2017-12-15

    The main objective of this study is to quantify the groundwater contamination risk of Songhua River Basin by applying a novel approach of integrating public datasets, web services and numerical modelling techniques. To our knowledge, this study is the first to establish groundwater risk maps for the entire Songhua River Basin, one of the largest and most contamination-endangered river basins in China. Index-based groundwater risk maps were created with GIS tools at a spatial resolution of 30arc sec by combining the results of groundwater vulnerability and hazard assessment. Groundwater vulnerability was evaluated using the DRASTIC index method based on public datasets at the highest available resolution in combination with numerical groundwater modelling. As a novel approach to overcome data scarcity at large scales, a web mapping service based data query was applied to obtain an inventory for potential hazardous sites within the basin. The groundwater risk assessment demonstrated that contamination risk. These areas were mainly located in the vast plain areas with hotspots particularly in the Changchun metropolitan area. Moreover, groundwater levels and pollution point sources were found to play a significantly larger impact in assessing these areas than originally assumed by the index scheme. Moderate contamination risk was assigned to 27% of the aquifers, predominantly associated with less densely populated agricultural areas. However, the majority of aquifer area in the sparsely populated mountain ranges displayed low groundwater contamination risk. Sensitivity analysis demonstrated that this novel method is valid for regional assessments of groundwater contamination risk. Despite limitations in resolution and input data consistency, the obtained groundwater contamination risk maps will be beneficial for regional and local decision-making processes with regard to groundwater protection measures, particularly if other data availability is limited. Copyright

  1. Differential environmental impacts on small and medium size rivers from center of São Paulo State, Brazil, and regional management perspectives

    Directory of Open Access Journals (Sweden)

    Paula Caroline dos Reis Oliveira

    2014-12-01

    Full Text Available AIM: This study aimed to evaluate, comparatively, the influence of distinct environmental impacts in the watershed on the rivers Capivara, Lavapés, Araquá and Pardo and the transference of effects downstream. METHODS: The limnological/water quality study was carried out in rainy (March/2007 and dry (September/2007 seasons, considering 17 sampling stations. RESULTS: Variables such as channel width and depth, water velocity and temperature increased towards the river's mouth; water transparency, velocity and dissolved oxygen were higher in the upstream regions. Light penetration was total at most sampling stations and pH was predominantly acid. The sampling stations impacted by pollution sources, Lavapés and Araquá Rivers, exhibited higher values of electric conductivity, suspended solids, total nitrogen, nitrate, nitrite, ammonium, total dissolved phosphorus, BOD, and thermotolerant coliforms. Higher values of electric conductivity, turbidity and suspended solids were observed in the rainy season, whereas higher chlorophyll concentrations occurred in the dry season. The Lavapés River exhibits the worst environmental condition, while Capivara River is under better state of conservation. This study shows that it is urgent the implementation of measures for preservation and restoration of these regional aquatic ecosystems. All studied rivers were influenced by seasonal variation, sewage discharges and by watershed use and occupation. The TSI is a good analysis tool. The studied rivers export organic matter and TN, TP and SS loads to Tietê and Paranapanema rivers. CONCLUSIONS: This study show the importance of river management and that the accelerated degradation of the river systems indicates the little progress of the Brazilian legislation in terms of preservation and good management practices and that the interface between science, law, management and conservation need to be improved.

  2. Source areas and chemical composition of fine particulate matter in the Pearl River Delta region of China

    Science.gov (United States)

    Hagler, G. S. W.; Bergin, M. H.; Salmon, L. G.; Yu, J. Z.; Wan, E. C. H.; Zheng, M.; Zeng, L. M.; Kiang, C. S.; Zhang, Y. H.; Lau, A. K. H.; Schauer, J. J.

    Fine particulate matter (PM 2.5) was measured for 4 months during 2002-2003 at seven sites located in the rapidly developing Pearl River Delta region of China, an area encompassing the major cities of Hong Kong, Shenzhen and Guangzhou. The 4-month average fine particulate matter concentration ranged from 37 to 71 μg m -3 in Guangdong province and from 29 to 34 μg m -3 in Hong Kong. Main constituents of fine particulate mass were organic compounds (24-35% by mass) and sulfate (21-32%). With sampling sites strategically located to monitor the regional air shed patterns and urban areas, specific source-related fine particulate species (sulfate, organic mass, elemental carbon, potassium and lead) and daily surface winds were analyzed to estimate influential source locations. The impact of transport was investigated by categorizing 13 (of 20 total) sampling days by prevailing wind direction (southerly, northerly or low wind-speed mixed flow). The vicinity of Guangzhou is determined to be a major source area influencing regional concentrations of PM 2.5, with levels observed to increase by 18-34 μg m -3 (accounting for 46-56% of resulting particulate levels) at sites immediately downwind of Guangzhou. The area near Guangzhou is also observed to heavily impact downwind concentrations of lead. Potassium levels, related to biomass burning, appear to be controlled by sources in the northern part of the Pearl River Delta, near rural Conghua and urban Guangzhou. Guangzhou appears to contribute 5-6 μg m -3 of sulfate to downwind locations. Guangzhou also stands out as a significant regional source of organic mass (OM), adding 8.5-14.5 μg m -3 to downwind concentrations. Elemental carbon is observed to be strongly influenced by local sources, with highest levels found in urban regions. In addition, it appears that sources outside of the Pearl River Delta contribute a significant fraction of overall fine particulate matter in Hong Kong and Guangdong province. This is evident

  3. Effects of sediment quality on macroinvertebrates in the Sunraysia region of the Murray-Darling Rivers, Australia

    Energy Technology Data Exchange (ETDEWEB)

    Sharley, David J. [Centre for Environmental Stress and Adaptation Research-Hoffmann Laboratory, Zoology Department, University of Melbourne, Level 2, Bio 21 Institute, 30 Flemington Road, Parkville, Victoria 3010 (Australia)], E-mail: sharleyd@unimelb.edu.au; Hoffmann, Ary A. [Centre for Environmental Stress and Adaptation Research-Hoffmann Laboratory, Zoology Department, University of Melbourne, Level 2, Bio 21 Institute, 30 Flemington Road, Parkville, Victoria 3010 (Australia); Pettigrove, Vincent [Research and Technology, Melbourne Water, PO Box 4342, Melbourne, Victoria 3001 (Australia)

    2008-12-15

    A field-based microcosm approach was tested to identify deterioration of sediment quality in waterways using freshwater macroinvertebrates. The method can potentially identify the nature of contaminants based on species-specific responses. Sediments were collected from the Murray and Darling Rivers and irrigation drains within the Sunraysia region of south-eastern Australia and compared to non-polluted reference sediment. Clean sediments were also spiked with fertiliser to test whether nutrients affected the aquatic fauna. Seven of the eight sediments from the Sunraysia region had a negative impact on the macroinvertebrates, in particular sediment from the Darling River, which supported an impoverished fauna. Three species of chironomid showed varied responses to sediment quality and, although it was hypothesised that nutrients may have impacted on the macroinvertebrate fauna, the results suggest that other pollutants are also involved. The field-based microcosm method proved effective for determining the impact of sediment quality on indigenous macroinvertebrates. - Sediment quality effects on freshwater macroinvertebrates are isolated.

  4. Using NASA's Giovanni System to Simulate Time-Series Stations in the Outflow Region of California's Eel River

    Science.gov (United States)

    Acker, James G.; Shen, Suhung; Leptoukh, Gregory G.; Lee, Zhongping

    2012-01-01

    Oceanographic time-series stations provide vital data for the monitoring of oceanic processes, particularly those associated with trends over time and interannual variability. There are likely numerous locations where the establishment of a time-series station would be desirable, but for reasons of funding or logistics, such establishment may not be feasible. An alternative to an operational time-series station is monitoring of sites via remote sensing. In this study, the NASA Giovanni data system is employed to simulate the establishment of two time-series stations near the outflow region of California s Eel River, which carries a high sediment load. Previous time-series analysis of this location (Acker et al. 2009) indicated that remotely-sensed chl a exhibits a statistically significant increasing trend during summer (low flow) months, but no apparent trend during winter (high flow) months. Examination of several newly-available ocean data parameters in Giovanni, including 8-day resolution data, demonstrates the differences in ocean parameter trends at the two locations compared to regionally-averaged time-series. The hypothesis that the increased summer chl a values are related to increasing SST is evaluated, and the signature of the Eel River plume is defined with ocean optical parameters.

  5. Effects of sediment quality on macroinvertebrates in the Sunraysia region of the Murray-Darling Rivers, Australia

    International Nuclear Information System (INIS)

    Sharley, David J.; Hoffmann, Ary A.; Pettigrove, Vincent

    2008-01-01

    A field-based microcosm approach was tested to identify deterioration of sediment quality in waterways using freshwater macroinvertebrates. The method can potentially identify the nature of contaminants based on species-specific responses. Sediments were collected from the Murray and Darling Rivers and irrigation drains within the Sunraysia region of south-eastern Australia and compared to non-polluted reference sediment. Clean sediments were also spiked with fertiliser to test whether nutrients affected the aquatic fauna. Seven of the eight sediments from the Sunraysia region had a negative impact on the macroinvertebrates, in particular sediment from the Darling River, which supported an impoverished fauna. Three species of chironomid showed varied responses to sediment quality and, although it was hypothesised that nutrients may have impacted on the macroinvertebrate fauna, the results suggest that other pollutants are also involved. The field-based microcosm method proved effective for determining the impact of sediment quality on indigenous macroinvertebrates. - Sediment quality effects on freshwater macroinvertebrates are isolated

  6. Influence of Plastic Covering on the Microclimate in Vineyards in the São Francisco River Valley Region

    Directory of Open Access Journals (Sweden)

    Mário de Miranda Vilas Boas Ramos Leitão

    Full Text Available Abstract Data from field experiments conducted in table grape vineyards variety of Festival in Petrolina-PE in the period from September 19 to October 12, 2010 were used to evaluate the influence of plastic cover on microclimate conditions of vineyards in São Francisco River Valley region. Three treatments were studied: canopies without plastic cover (WC; with plastic cover positioned at 50 cm (PC50, and at 100 cm (PC100 above canopy. The results indicate that the plastic cover prevented the passage of about 40% of the global and net radiation, retained the relative humidity inside the canopy, generated an increase of air temperature and marked reduction in wind speed over the canopy of treatment PC50. However, treatment PC100 had a higher incidence of short wavelength and net radiation under canopy (on the berries than WC and PC50 treatments, resulting in more favorable weather conditions, providing about 40% greater productivity in this treatment. Therefore, the vineyard with plastic cover placed at 100 cm above canopy represents a more suitable alternative to the climatic conditions of the region of the São Francisco River Valley.

  7. Assessment on the Effect of Climate Change on Streamflow in the Source Region of the Yangtze River, China

    Directory of Open Access Journals (Sweden)

    Huanqing Bian

    2017-01-01

    Full Text Available Tuotuo River basin, known as the source region of the Yangtze River, is the key area where the impact of climate change has been observed on many of the hydrological processes of this central region of the Tibetan Plateau. In this study, we examined six Global Climate Models (GCMs under three Representative Concentration Pathways (RCPs scenarios. First, the already impacted climate change was analyzed, based on the historical data available and then, the simulation results of the GCMs and RCPs were used for future scenario assessments. Results indicated that the annual mean temperature will likely be increased, ranging from −0.66 °C to 6.68 °C during the three future prediction periods (2020s, 2050s and 2080s, while the change in the annual precipitation ranged from −1.18% to 66.14%. Then, a well-known distributed hydrological soil vegetation model (DHSVM was utilized to evaluate the effects of future climate change on the streamflow dynamics. The seasonal mean streamflows, predicted by the six GCMs and the three RCPs scenarios, were also shown to likely increase, ranging from −0.52% to 22.58%. Watershed managers and regulators can use the findings from this study to better implement their conservation practices in the face of climate change.

  8. Improving regional climate and hydrological forecasting following the record setting flooding across the Lake Ontario - St. Lawrence River system

    Science.gov (United States)

    Gronewold, A.; Seglenieks, F.; Bruxer, J.; Fortin, V.; Noel, J.

    2017-12-01

    In the spring of 2017, water levels across Lake Ontario and the upper St. Lawrence River exceeded record high levels, leading to widespread flooding, damage to property, and controversy over regional dam operating protocols. Only a few years earlier, water levels on Lakes Superior, Michigan, and Huron (upstream of Lake Ontario) had dropped to record low levels leading to speculation that either anthropogenic controls or climate change were leading to chronic water loss from the Great Lakes. The contrast between low water level conditions across Earth's largest lake system from the late 1990s through 2013, and the rapid rise prior to the flooding in early 2017, underscores the challenges of quantifying and forecasting hydrologic impacts of rising regional air and water temperatures (and associated changes in lake evaporation) and persistent increases in long-term precipitation. Here, we assess the hydrologic conditions leading to the recent record flooding across the Lake Ontario - St. Lawrence River system, with a particular emphasis on understanding the extent to which those conditions were consistent with observed and anticipated changes in historical and future climate, and the extent to which those conditions could have been anticipated through improvements in seasonal climate outlooks and hydrological forecasts.

  9. Linking Backbarrier Lacustrine Stratigraphy with Spatial Dynamics of Shoreline Retreat in a Rapidly Subsiding Region of the Mississippi River Delta

    Science.gov (United States)

    Dietz, M.; Liu, K. B.; Bianchette, T. A.; Yao, Q.

    2017-12-01

    The shoreline along the northern Gulf of Mexico is rapidly retreating as coastal features of abandoned Mississippi River delta complexes erode and subside. Bay Champagne is located in the Caminada-Moreau headland, a region of shoreline west of the currently active delta that has one of the highest rates of retreat and land loss. As a result, this site has transitioned from a stable, circular inland lake several kilometers from the shore to a frequently perturbed, semi-circular backbarrier lagoon, making it ideal to study the environmental effects of progressive land loss. Analyses of clastic layers in a series of sediment cores collected at this site over the past decade indicate the lake was less perturbed in the past and has become increasingly more sensitive to marine incursion events caused by tropical cyclones. Geochemical and pollen analyses of these cores also reveal profound changes in environmental and chemical conditions in Bay Champagne over the past century as the shoreline has retreated. Through relating stratigraphy to spatial changes observed from satellite imagery, this study attempts to identify the tipping point at which Bay Champagne began the transition from an inland lake to a backbarrier environment, and to determine the rate at which this transition occurred. Results will be used to develop a model of the environmental transition experienced by a rapidly retreating coastline and to predict how other regions of the Mississippi River deltaic system could respond to future shoreline retreat.

  10. Palms and Palm Communities in the Upper Ucayali River Valley - a Little-Known Region in the Amazon Basin

    DEFF Research Database (Denmark)

    Balslev, Henrik; Eiserhardt, Wolf L.; Kristiansen, Thea

    2010-01-01

    The Amazon region and its palms are inseparable. Palms make up such an important part of the rain forest ecosystem that it is impossible to imagine the Amazon basin without them. Palms are visible in the canopy and often fill up the forest understory. Palms – because of their edible fruits...... – are cornerstone species for the survival of many animals, and palms contribute substantially to forest inventories in which they are often among the ten most important families. Still, the palms and palm communities of some parts of the Amazon basin remain poorly studied and little known. We travelled to a little......-explored corner of the western Amazon basin, the upper Ucayali river valley. There, we encountered 56 different palms, 18 of which had not been registered for the region previously, and 21 of them were found 150–400 km beyond their previously known limits....

  11. Chronology of Miocene-Pliocene deposits at Split Mountain Gorge, Southern California: A record of regional tectonics and Colorado River evolution

    Science.gov (United States)

    Dorsey, R.J.; Fluette, A.; McDougall, K.; Housen, B.A.; Janecke, S.U.; Axen, G.J.; Shirvell, C.R.

    2007-01-01

    Late Miocene to early Pliocene deposit at Split Mountain Gorge, California, preserve a record of basinal response to changes in regional tectonics, paleogeography, and evolution of the Colorado River. The base of the Elephant Trees Formation, magnetostratigraphically dated as 8.1 ?? 0.4 Ma, provides the earliest well-dated record of extension in the southwestern Salton Trough. The oldest marine sediments are ca. 6.3 Ma. The nearly synchronous timing of marine incursion in the Salton Trough and northern Gulf of California region supports a model for localization of Pacific-North America plate motion in the Gulf ca. 6 Ma. The first appearance of Colorado River sand at the Miocene-Pliocene boundary (5.33 Ma) suggests rapid propagation of the river to the Salton Trough, and supports a lake-spillover hypothesis for initiation of the lower Colorado River. ?? 2007 Geological Society of America.

  12. Geology, selected geophysics, and hydrogeology of the White River and parts of the Great Salt Lake Desert regional groundwater flow systems, Utah and Nevada

    Science.gov (United States)

    Rowley, Peter D.; Dixon, Gary L.; Watrus , James M.; Burns, Andrews G.; Mankinen, Edward A.; McKee, Edwin H.; Pari, Keith T.; Ekren, E. Bartlett; Patrick , William G.; Comer, John B.; Inkenbrandt, Paul C.; Krahulec, K.A.; Pinnell, Michael L.

    2016-01-01

    The east-central Great Basin near the Utah-Nevada border contains two great groundwater flow systems. The first, the White River regional groundwater flow system, consists of a string of hydraulically connected hydrographic basins in Nevada spanning about 270 miles from north to south. The northernmost basin is Long Valley and the southernmost basin is the Black Mountain area, a valley bordering the Colorado River. The general regional groundwater flow direction is north to south. The second flow system, the Great Salt Lake Desert regional groundwater flow system, consists of hydrographic basins that straddle

  13. Why is the Arkavathy River drying? A multiple hypothesis approach in a data scarce region

    Science.gov (United States)

    Srinivasan, V.; Thompson, S.; Madhyastha, K.; Penny, G.; Jeremiah, K.; Lele, S.

    2015-01-01

    The developing world faces unique challenges in achieving water security as it is disproportionately exposed to stressors such as climate change while also undergoing demographic growth, agricultural intensification and industrialization. Investigative approaches are needed that can inform sound policy development and planning to address the water security challenge in the context of data scarcity. We investigated the "predictions under change" problem in the Thippagondanahalli (TG Halli) catchment of the Arkavathy sub-basin in South India. River inflows into the TG Halli reservoir have declined since the 1970s, and the reservoir is currently operating at only 20% of its built capacity. The mechanisms responsible for the drying of the river are not understood, resulting in uncoordinated and potentially counter-productive management responses. The objective of this study was to investigate potential explanations of the drying trend and thus obtain predictive insight. We used a multiple working hypothesis approach to investigate the decline in inflow into TG Halli reservoir. Five hypotheses were tested using data from field surveys and reliable secondary sources: (1) changes in rainfall amount, timing and storm intensity, (2) rising temperatures, (3) increased groundwater extraction, (4) expansion of eucalyptus plantations, and (5) increased fragmentation of the river channel. Our results indicate that proximate anthropogenic drivers of change such as groundwater pumping, expansion of eucalyptus plantations, and to a lesser extent channel fragmentation, are much more likely to have caused the decline in surface flows in the TG Halli catchment than changing climate. The case study shows that direct human interventions play a significant role in altering the hydrology of watersheds. The multiple working hypotheses approach presents a systematic way to quantify the relative contributions of anthropogenic drivers to hydrologic change. The approach not only yields a

  14. Analysis of heavy metal flow in the river Przemsza, Katowice region, using macrophytes

    Energy Technology Data Exchange (ETDEWEB)

    Lewander, M.

    1995-06-01

    The river Przemsza, in southern Poland, was investigated with the aim to determine the flow of Cd, Pb and Zn between the submerged macrophytes Potamogeton pectinatus and Myriophyllum verticillatum, sediment and water, and to find out if a pollution gradient was present along the investigated part of the river. In order to determine the uptake of heavy metals from water and sediment macrophytes were planted in pots along the river, in unpolluted and polluted sediment during six weeks in the summer of 1993. After harvesting the plants were dried, wet digested and analysed by atomic absorption spectrophotometry. Parallel in situ experiments and outdoor experiments in sealed jars were performed. No significant decreased pollution gradient in the sediment or the macrophytes content could be detected. However, the water concentration of Zn decreased slightly along the gradient and in both experiments Pb concentration in the water also decreased. The concentrations of metals in the plants and sediments were probably depending on local stream conditions as well as increasing organic content. The study suggests that the macrophytes took up metals both from water and sediment. The unpolluted sediment accumulated Pb and Zn in both experiments, while Cd was accumulated in the in situ experiment. Metal concentration in the polluted sediment decreased during the study period, either due to plant uptake or loss to the water. Metals lost from the polluted sediment to the water were taken up by the plant shoots. Lead mainly accumulated in the roots while Zn accumulated in the plant shoots, and Cd was distributed almost equally between shoots and roots. 18 refs, 2 figs, 6 tabs

  15. Economic Analysis of the Impacts of Climate-Induced Changes in River Flow on Hydropower and Fisheries in Himalayan region.

    Science.gov (United States)

    Khadka Mishra, S.; Hayse, J.; Veselka, T.; Yan, E.; Kayastha, R. B.; McDonald, K.; Steiner, N.; Lagory, K.

    2017-12-01

    Climate-mediated changes in melting of snow and glaciers and in precipitation patterns are expected to significantly alter the water flow of rivers at various spatial and temporal scales. Hydropower generation and fisheries are likely to be impacted annually and over the century by the seasonal as well as long-term changes in hydrological conditions. In order to quantify the interactions between the drivers of climate change, the hydropower sector and the ecosystem we developed an integrated assessment framework that links climate models with process-based bio-physical and economic models. This framework was applied to estimate the impacts of changes in snow and glacier melt on the stream flow of the Trishuli River of the High Mountain Asia Region. Remotely-sensed data and derived products, as well as in-situ data, were used to quantify the changes in snow and glacier melt. The hydrological model was calibrated and validated for stream flows at various points in the Trishuli river in order to forecast conditions at the location of a stream gauge station upstream of the Trishuli hydropower plant. The flow of Trishuli River was projected to increase in spring and decrease in summer over the period of 2020-2100 under RCP 8.5 and RCP 4.5 scenarios as compared to respective mean seasonal discharge observed over 1981-2014. The simulated future annual mean stream flow would increase by 0.6 m3/s under RCP 8.5 scenario but slightly decrease under RCP 4.5. The Argonne Hydropower Energy and Economic toolkit was used to estimate and forecast electricity generation at the Trishuli power plant under various flow conditions and upgraded infrastructure. The increased spring flow is expected to increase dry-season electricity generation by 18% under RCP 8.5 in comparison to RCP 4.5. A fishery suitability model developed for the basin indicated that fishery suitability in the Trishuli River would be greater than 70% of optimal, even during dry months under both RCP 4.5 and RCP 8

  16. Regional Hydrology of the Green River-Moab Area, Northwestern Paradox Basin, Utah

    OpenAIRE

    United States Geological Survey

    1982-01-01

    The Green River-Moab area encompasses about 7,800 square kilometers or about 25 percent of the Paradox basin. The entire Paradox basin is a part of the Colorado Plateaus that is underlain by a thick sequence of evaporite (salt) beds of Pennsylvanian age. The rock units that underlie the area have been grouped into hydrogeologic units based on their water-transmitting ability. Confining beds consist of evaporite beds of mostly salt, and overlying and underlying thick sequences of rocks with...

  17. Impact of river stage prediction methods on stream-aquifer exchanges in a hydro(geo)logical model at the regional scale

    Science.gov (United States)

    Saleh, F.; Flipo, N.; de Fouquet, C.

    2012-04-01

    The main objective of this study is to provide a realistic simulation of river stage in regional river networks in order to improve the quantification of stream-aquifer exchanges and better assess the associated aquifer responses that are often impacted by the magnitude and the frequency of the river stage fluctuations. The study focuses on the Oise basin (17 000 km2, part of the 65 000 km2 Seine basin in Northern France) where stream-aquifer exchanges cannot be assessed directly by experimental methods. Nowadays numerical methods are the most appropriate approaches for assessing stream-aquifer exchanges at this scale. A regional distributed process-based hydro(geo)logical model, Eau-Dyssée, is used, which aims at the integrated modeling of the hydrosystem to manage the various elements involved in the quantitative and qualitative aspects of water resources. Eau-Dyssée simulates pseudo 3D flow in aquifer systems solving the diffusivity equation with a finite difference numerical scheme. River flow is simulated with a Muskingum model. In addition to the in-stream discharge, a river stage estimate is needed to calculate the water exchange at the stream-aquifer interface using the Darcy law. Three methods for assessing in-stream river stages are explored to determine the most appropriate representation at regional scale over 25 years (1980-2005). The first method consists in defining rating curves for each cell of a 1D Saint-Venant hydraulic model. The second method consists in interpolating observed rating curves (at gauging stations) onto the river cells of the hydro(geo)logical model. The interpolation technique is based on geostatistics. The last method assesses river stage using Manning equation with a simplified rectangular cross-section (water depth equals the hydraulic radius). Compared to observations, the geostatistical and the Manning methodologies lead to slightly less accurate (but still acceptable) results offering a low computational cost opportunity

  18. Simulation of regional temperature change effect of land cover change in agroforestry ecotone of Nenjiang River Basin in China

    Science.gov (United States)

    Liu, Tingxiang; Zhang, Shuwen; Yu, Lingxue; Bu, Kun; Yang, Jiuchun; Chang, Liping

    2017-05-01

    The Northeast China is one of typical regions experiencing intensive human activities within short time worldwide. Particularly, as the significant changes of agriculture land and forest, typical characteristics of pattern and process of agroforestry ecotone change formed in recent decades. The intensive land use change of agroforestry ecotone has made significant change for regional land cover, which had significant impact on the regional climate system elements and the interactions among them. This paper took agroforestry ecotone of Nenjiang River Basin in China as study region and simulated temperature change based on land cover change from 1950s to 1978 and from 1978 to 2010. The analysis of temperature difference sensitivity to land cover change based on Weather Research and Forecasting (WRF) model showed that the land cover change from 1950s to 1978 induced warming effect over all the study area, including the change of grassland to agriculture land, grassland to deciduous broad-leaved forest, and deciduous broad-leaved forest to shrub land. The land cover change from 1978 to 2010 induced cooling effect over all the study area, including the change of deciduous broad-leaved forest to agriculture land, grassland to agriculture land, shrub land to agriculture land, and deciduous broad-leaved forest to grassland. In addition, the warming and cooling effect of land cover change was more significant in the region scale than specific land cover change area.

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

    International Nuclear Information System (INIS)

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

    2014-01-01

    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. - Highlights: • PFAAs were detected in rapidly urbanized regions. • PFOA was found predominant followed by short chain PFCAs. • Fluoropolymer facilities were associated with PFAAs contamination. • Higher PFAAs levels were found near the PTFE production facilities. • Diffusion of PFAAs from rivers to the sea was influenced by tide and current. - High level of PFOA was detected in the river water due to the fluoropolymer industries in South Bohai coastal region

  20. Post-hatching development of mitochondrial function, organ mass and metabolic rate in two ectotherms, the American alligator (Alligator mississippiensis and the common snapping turtle (Chelydra serpentina

    Directory of Open Access Journals (Sweden)

    Sarah K. G. Sirsat

    2016-04-01

    Full Text Available The ontogeny of endothermy in birds is associated with disproportionate growth of thermogenic organs and increased mitochondrial oxidative capacity. However, no similar study has been made of the development of these traits in ectotherms. For comparison, we therefore investigated the metabolism, growth and muscle mitochondrial function in hatchlings of a turtle and a crocodilian, two ectotherms that never develop endothermy. Metabolic rate did not increase substantially in either species by 30 days post-hatching. Yolk-free body mass and heart mass did not change through 30 days in alligators and heart mass was a constant proportion of body mass, even after 1 year. Yolk-free body mass and liver mass grew 36% and 27%, respectively, in turtles during the first 30 days post-hatch. The mass-specific oxidative phosphorylation capacity of mitochondria, assessed using permeabilized muscle fibers, increased by a non-significant 47% in alligator thigh and a non-significant 50% in turtle thigh over 30 days, but did not increase in the heart. This developmental trajectory of mitochondrial function is slower and shallower than that previously observed in ducks, which demonstrate a 90% increase in mass-specific oxidative phosphorylation capacity in thigh muscles over just a few days, a 60% increase in mass-specific oxidative phosphorylation capacity of the heart over a few days, and disproportionate growth of the heart and other organs. Our data thus support the hypothesis that these developmental changes in ducks represent mechanistic drivers for attaining endothermy.

  1. Post-hatching development of mitochondrial function, organ mass and metabolic rate in two ectotherms, the American alligator (Alligator mississippiensis) and the common snapping turtle (Chelydra serpentina).

    Science.gov (United States)

    Sirsat, Sarah K G; Sirsat, Tushar S; Price, Edwin R; Dzialowski, Edward M

    2016-04-15

    The ontogeny of endothermy in birds is associated with disproportionate growth of thermogenic organs and increased mitochondrial oxidative capacity. However, no similar study has been made of the development of these traits in ectotherms. For comparison, we therefore investigated the metabolism, growth and muscle mitochondrial function in hatchlings of a turtle and a crocodilian, two ectotherms that never develop endothermy. Metabolic rate did not increase substantially in either species by 30 days post-hatching. Yolk-free body mass and heart mass did not change through 30 days in alligators and heart mass was a constant proportion of body mass, even after 1 year. Yolk-free body mass and liver mass grew 36% and 27%, respectively, in turtles during the first 30 days post-hatch. The mass-specific oxidative phosphorylation capacity of mitochondria, assessed using permeabilized muscle fibers, increased by a non-significant 47% in alligator thigh and a non-significant 50% in turtle thigh over 30 days, but did not increase in the heart. This developmental trajectory of mitochondrial function is slower and shallower than that previously observed in ducks, which demonstrate a 90% increase in mass-specific oxidative phosphorylation capacity in thigh muscles over just a few days, a 60% increase in mass-specific oxidative phosphorylation capacity of the heart over a few days, and disproportionate growth of the heart and other organs. Our data thus support the hypothesis that these developmental changes in ducks represent mechanistic drivers for attaining endothermy. © 2016. Published by The Company of Biologists Ltd.

  2. Floristic and structural status of forests in permanent preservation areas of Moju river basin, Amazon region.

    Science.gov (United States)

    Oliveira, J C; Vieira, I C G; Almeida, A S; Silva, C A

    2016-01-01

    The goal of this study is to analyze the floristic patterns and the structure of disturbed and undisturbed upland forests, in Permanent Preservation Areas (PPAs) along the Moju river, in the Brazilian state of Pará. Trees with a diameter equal to or larger than 10cm at 1.30m from the ground (DBH) ≥10cm were analyzed for the upper stratum. For the middle stratum, individuals with DBH between 4.99 and 9.99cm were sampled. Forty-five families and 221 species were found in disturbed forests, and 43 families and 208 species in undisturbed forests. Floristic similarity was high between strata and between forest types, with values above 50%. Similarity was highest between middle strata. The most species-abundant families in undisturbed forests were Fabaceae, Sapotaceae, Chrysobalanaceae and Myrtaceae; the species with the highest density there were Eschweilera grandiflora, Licania sclerophylla and Zygia cauliflora. In disturbed forests, the dominant families were Fabaceae, Sapotaceae, Lecythidaceae and Melastomataceae. The Shannon-Wiener diversity index was 3.21 for undisturbed forests and 2.85 for disturbed forests. Non-metric multidimensional scaling (MDS) analysis did not group the forests by their floristic composition in both upper and middle strata. Overall, the PPA forests along the Moju river, even if disturbed, did not show major floristic changes but substantially change their structural characteristics.

  3. Floristic and structural status of forests in permanent preservation areas of Moju river basin, Amazon region

    Directory of Open Access Journals (Sweden)

    J. C. Oliveira

    Full Text Available Abstract The goal of this study is to analyze the floristic patterns and the structure of disturbed and undisturbed upland forests, in Permanent Preservation Areas (PPAs along the Moju river, in the Brazilian state of Pará. Trees with a diameter equal to or larger than 10cm at 1.30m from the ground (DBH ≥10cm were analyzed for the upper stratum. For the middle stratum, individuals with DBH between 4.99 and 9.99cm were sampled. Forty-five families and 221 species were found in disturbed forests, and 43 families and 208 species in undisturbed forests. Floristic similarity was high between strata and between forest types, with values above 50%. Similarity was highest between middle strata. The most species-abundant families in undisturbed forests were Fabaceae, Sapotaceae, Chrysobalanaceae and Myrtaceae; the species with the highest density there were Eschweilera grandiflora, Licania sclerophylla and Zygia cauliflora. In disturbed forests, the dominant families were Fabaceae, Sapotaceae, Lecythidaceae and Melastomataceae. The Shannon-Wiener diversity index was 3.21 for undisturbed forests and 2.85 for disturbed forests. Non-metric multidimensional scaling (MDS analysis did not group the forests by their floristic composition in both upper and middle strata. Overall, the PPA forests along the Moju river, even if disturbed, did not show major floristic changes but substantially change their structural characteristics.

  4. Source apportionment and health effect of NO_x over the Pearl River Delta region in southern China

    International Nuclear Information System (INIS)

    Lu, Xingcheng; Yao, Teng; Li, Ying; Fung, Jimmy C.H.; Lau, Alexis K.H.

    2016-01-01

    As one of the most notorious atmospheric pollutants, NO_x not only promotes the formation of ozone but also has adverse health effects on humans. It is therefore of great importance to study the sources of NO_x and its effects on human health. The Comprehensive Air Quality Model (CAMx) modeling system and ozone source apportionment technology (OSAT) were used to study the contribution of NO_x from different emission sources over southern China. The results indicate that heavy duty diesel vehicles (HDDVs) and industrial point sources are the two major local NO_x sources, accounting for 30.8% and 18.5% of local NO_x sources, respectively. In Hong Kong, marine emissions contributed around 43.4% of local NO_x in 2011. Regional transport is another important source of this pollutant, especially in February and November, and it can contribute over 30% of ambient NO_x on average. Power plant point emission is an significant regional source in Zhuhai, Zhongshan and Foshan. The total emission sources are estimated to cause 2119 (0–4405) respiratory deaths and 991 (0–2281) lung cancer deaths due to long-term exposure to NO_x in the Pearl River Delta region. Our results suggest that local governments should combine their efforts and vigorously promote further reduction of NO_x emissions, especially for those sources that make a substantial contribution to NO_x emissions and affect human health: HDDV, LDGV, industrial point sources and marine sources. - Highlights: • WRF-CAMx modeling system with OSAT was used to study the source of NO_x over Pearl River Delta region in China. • The results indicated that local emission and regional transportation are important contributors for NO_x in this region. • Heavy duty diesel vehicle, marine emission and industrial point source are three important contribution sectors. • Long-term exposure to NO_x is estimated to cause 2119 respiratory deaths and 991 lung cancer deaths in PRD during 2011. - Result indicated that heavy duty

  5. The alligator woman's tale: remembering Nicaragua's "first self-declared lesbian".

    Science.gov (United States)

    González-Rivera, Victoria

    2014-01-01

    Carmen Aguirre (1931-1971) was a young woman who lived as a self-made man in the 1960s under the brutal, yet populist, right-wing Somoza dictatorship in Nicaragua. Carmen was known as Carmelo or la Caimana (the alligator woman). This article sheds light not only on la Caimana's life, but on how he is remembered today in Nicaragua. It addresses dynamics of Nicaragua's sexual past, present, and future, as well as theoretical questions dealing with identity, sex, and politics.

  6. Quantifying the streamflow response to frozen ground degradation in the source region of the Yellow River within the Budyko framework

    Science.gov (United States)

    Wang, Taihua; Yang, Hanbo; Yang, Dawen; Qin, Yue; Wang, Yuhan

    2018-03-01

    The source region of the Yellow River (SRYR) is greatly important for water resources throughout the entire Yellow River Basin. Streamflow in the SRYR has experienced great changes over the past few decades, which is closely related to the frozen ground degradation; however, the extent of this influence is still unclear. In this study, the air freezing index (DDFa) is selected as an indicator for the degree of frozen ground degradation. A water-energy balance equation within the Budyko framework is employed to quantify the streamflow response to the direct impact of climate change, which manifests as changes in the precipitation and potential evapotranspiration, as well as the impact of frozen ground degradation, which can be regarded as part of the indirect impact of climate change. The results show that the direct impact of climate change and the impact of frozen ground degradation can explain 55% and 33%, respectively, of the streamflow decrease for the entire SRYR from Period 1 (1965-1989) to Period 2 (1990-2003). In the permafrost-dominated region upstream of the Jimai hydrological station, the impact of frozen ground degradation can explain 71% of the streamflow decrease. From Period 2 (1990-2003) to Period 3 (2004-2015), the observed streamflow did not increase as much as the precipitation; this could be attributed to the combined effects of increasing potential evapotranspiration and more importantly, frozen ground degradation. Frozen ground degradation could influence streamflow by increasing the groundwater storage when the active layer thickness increases in permafrost-dominated regions. These findings will help develop a better understanding of the impact of frozen ground degradation on water resources in the Tibetan Plateau.

  7. Increasing trends in rainfall-runoff erosivity in the Source Region of the Three Rivers, 1961-2012.

    Science.gov (United States)

    Wang, Yousheng; Cheng, Congcong; Xie, Yun; Liu, Baoyuan; Yin, Shuiqing; Liu, Yingna; Hao, Yanfang

    2017-08-15

    As the head source of the two longest rivers in China and the longest river in Southeast Asia, the East Qinghai-Tibetan Plateau (QTP) is experiencing increasing thaw snowmelt and more heavy precipitation events under global warming, which might lead to soil erosion risk. To understand the potential driving force of soil erosion and its relationship with precipitation in the context of climate change, this study analyzed long-term variations in annual rainfall-runoff erosivity, a climatic index of soil erosion, by using the Mann-Kendall statistical test and Theil and Sen's approach in the Source Region of the Three Rivers during 1961-2012. The results showed the followings: (i) increasing annual rainfall-runoff erosivity was observed over the past 52years, with a mean relative trend index (RT 1 ) value of 12.1%. The increasing trend was more obvious for the latest two decades: RT 1 was nearly three times larger than that over the entire period; (ii) more precipitation events and a higher precipitation amount were the major forces for the increasing rainfall-runoff erosivity; (iii) similar rising trends in sediment yields, which corresponded to rainfall-runoff erosivity under slightly increasing vegetation coverage in the study area, implied a large contribution of rainfall-runoff erosivity to the increasing sediment yields; and (iv) high warming rates increased the risk of soil destruction, soil erosion and sediment yields. Conservation measures, such as enclosing grassland, returning grazing land to grassland and rotation grazing since the 1980s, have maintained vegetation coverage and should be continued and strengthened. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. An Agent-Based Reasoning of Impacts of Regional Climate Changes on Land Use Changes in the Three-River Headwaters Region of China

    Directory of Open Access Journals (Sweden)

    Tao Zhang

    2013-01-01

    Full Text Available The land surface in Three-River Headwaters Region (TRHR, a typical ecological fragile zone of China, is quite sensitive to the climate changes which will destabilize certain ecosystem services valuable to the entire nation and neighboring countries. This study aimed to analyze the impacts of climate changes and agents’ adaptive behaviors on the regional land use changes with the agent based model (ABM. First, the main agents were extracted according to the production resources endowments and socioeconomic background. Then the agents’ land use behaviors were analyzed and parameterized. Thereafter, the ABM model was built to simulate the impacts of the climate changes on the regional land use changes and agents’ economic benefits. The results showed that the land use changes were mainly characterized by the increase of grassland and decrease of unused land area. Besides, the agents would get more wealth under the scenario without climate changes in the long term, even though the total income is lower than that under the scenario with climate changes. In addition, the sensitivity analysis indicated that the model is sensitive to the climatic conditions, market price of agricultural and animal husbandry products, government subsidies, and cost control.

  9. A comparative study of artificial neural network, adaptive neuro fuzzy inference system and support vector machine for forecasting river flow in the semiarid mountain region

    Science.gov (United States)

    He, Zhibin; Wen, Xiaohu; Liu, Hu; Du, Jun

    2014-02-01

    Data driven models are very useful for river flow forecasting when the underlying physical relationships are not fully understand, but it is not clear whether these data driven models still have a good performance in the small river basin of semiarid mountain regions where have complicated topography. In this study, the potential of three different data driven methods, artificial neural network (ANN), adaptive neuro fuzzy inference system (ANFIS) and support vector machine (SVM) were used for forecasting river flow in the semiarid mountain region, northwestern China. The models analyzed different combinations of antecedent river flow values and the appropriate input vector has been selected based on the analysis of residuals. The performance of the ANN, ANFIS and SVM models in training and validation sets are compared with the observed data. The model which consists of three antecedent values of flow has been selected as the best fit model for river flow forecasting. To get more accurate evaluation of the results of ANN, ANFIS and SVM models, the four quantitative standard statistical performance evaluation measures, the coefficient of correlation (R), root mean squared error (RMSE), Nash-Sutcliffe efficiency coefficient (NS) and mean absolute relative error (MARE), were employed to evaluate the performances of various models developed. The results indicate that the performance obtained by ANN, ANFIS and SVM in terms of different evaluation criteria during the training and validation period does not vary substantially; the performance of the ANN, ANFIS and SVM models in river flow forecasting was satisfactory. A detailed comparison of the overall performance indicated that the SVM model performed better than ANN and ANFIS in river flow forecasting for the validation data sets. The results also suggest that ANN, ANFIS and SVM method can be successfully applied to establish river flow with complicated topography forecasting models in the semiarid mountain regions.

  10. City-specific vehicle emission control strategies to achieve stringent emission reduction targets in China's Yangtze River Delta region.

    Science.gov (United States)

    Zhang, Shaojun; Wu, Ye; Zhao, Bin; Wu, Xiaomeng; Shu, Jiawei; Hao, Jiming

    2017-01-01

    The Yangtze River Delta (YRD) region is one of the most prosperous and densely populated regions in China and is facing tremendous pressure to mitigate vehicle emissions and improve air quality. Our assessment has revealed that mitigating vehicle emissions of NOx would be more difficult than reducing the emissions of other major vehicular pollutants (e.g., CO, HC and PM 2.5 ) in the YRD region. Even in Shanghai, where the emission control implemented are more stringent than in Jiangsu and Zhejiang, we observed little to no reduction in NOx emissions from 2000 to 2010. Emission-reduction targets for HC, NOx and PM 2.5 are determined using a response surface modeling tool for better air quality. We design city-specific emission control strategies for three vehicle-populated cities in the YRD region: Shanghai and Nanjing and Wuxi in Jiangsu. Our results indicate that even if stringent emission control consisting of the Euro 6/VI standards, the limitation of vehicle population and usage, and the scrappage of older vehicles is applied, Nanjing and Wuxi will not be able to meet the NOx emissions target by 2020. Therefore, additional control measures are proposed for Nanjing and Wuxi to further mitigate NOx emissions from heavy-duty diesel vehicles. Copyright © 2016. Published by Elsevier B.V.

  11. Variation of Runoff and Precipitation in the Hekou-Longmen Region of the Yellow River Based on Elasticity Analysis

    Directory of Open Access Journals (Sweden)

    Erhui Li

    2014-01-01

    Full Text Available Precipitation is very important to the formation of runoff, and studying of runoff variation and its response to precipitation has practical significance to sustainable utilization of water resources. The study used Mann-Kendall test, anomaly accumulation method, and precipitation elasticity of runoff method to analyze the changes in the relation of precipitation and runoff and the contribution of precipitation to runoff change in the Hekou-Longmen region (from 1957 to 2010, Huangfuchuan watershed (from 1954 to 2010, and Yanhe watershed (from 1952 to 2010 in the middle reaches of the Yellow River. The results showed that runoff appeared a significant decreasing trend (P=0.01 while it was not significant in precipitation in all study areas. In particular, the reductions of average annual runoff in the Hekou-Longmen region, Huangfuchuan watershed, and Yanhe watershed were 72.7%, 87.5%, and 32.2%, respectively, during 2000–2010 compared to the 1950s. There existed two abrupt change points of the runoff in the Hekou-Longmen region and Huangfuchuan watershed, which were detected in 1979 and 1998. But in the Yanhe watershed only one abrupt change point was found in 1996. The precipitation elasticities of runoff were 1.11, 1.09, and 1.26, respectively, and the contributions of precipitation on runoff reduction were 26.4%, 17.9%, and 31.6%, respectively, in the Hekou-Longmen region, Huangfuchuan watershed, and Yanhe watershed.

  12. Variation of Runoff and Precipitation in the Hekou-Longmen Region of the Yellow River Based on Elasticity Analysis

    Science.gov (United States)

    Li, Erhui; Mu, Xingmin; Zhao, Guangju; Gao, Peng; Shao, Hongbo

    2014-01-01

    Precipitation is very important to the formation of runoff, and studying of runoff variation and its response to precipitation has practical significance to sustainable utilization of water resources. The study used Mann-Kendall test, anomaly accumulation method, and precipitation elasticity of runoff method to analyze the changes in the relation of precipitation and runoff and the contribution of precipitation to runoff change in the Hekou-Longmen region (from 1957 to 2010), Huangfuchuan watershed (from 1954 to 2010), and Yanhe watershed (from 1952 to 2010) in the middle reaches of the Yellow River. The results showed that runoff appeared a significant decreasing trend (P = 0.01) while it was not significant in precipitation in all study areas. In particular, the reductions of average annual runoff in the Hekou-Longmen region, Huangfuchuan watershed, and Yanhe watershed were 72.7%, 87.5%, and 32.2%, respectively, during 2000–2010 compared to the 1950s. There existed two abrupt change points of the runoff in the Hekou-Longmen region and Huangfuchuan watershed, which were detected in 1979 and 1998. But in the Yanhe watershed only one abrupt change point was found in 1996. The precipitation elasticities of runoff were 1.11, 1.09, and 1.26, respectively, and the contributions of precipitation on runoff reduction were 26.4%, 17.9%, and 31.6%, respectively, in the Hekou-Longmen region, Huangfuchuan watershed, and Yanhe watershed. PMID:24955424

  13. Variation of runoff and precipitation in the Hekou-Longmen region of the Yellow River based on elasticity analysis.

    Science.gov (United States)

    Li, Erhui; Mu, Xingmin; Zhao, Guangju; Gao, Peng; Shao, Hongbo

    2014-01-01

    Precipitation is very important to the formation of runoff, and studying of runoff variation and its response to precipitation has practical significance to sustainable utilization of water resources. The study used Mann-Kendall test, anomaly accumulation method, and precipitation elasticity of runoff method to analyze the changes in the relation of precipitation and runoff and the contribution of precipitation to runoff change in the Hekou-Longmen region (from 1957 to 2010), Huangfuchuan watershed (from 1954 to 2010), and Yanhe watershed (from 1952 to 2010) in the middle reaches of the Yellow River. The results showed that runoff appeared a significant decreasing trend (P = 0.01) while it was not significant in precipitation in all study areas. In particular, the reductions of average annual runoff in the Hekou-Longmen region, Huangfuchuan watershed, and Yanhe watershed were 72.7%, 87.5%, and 32.2%, respectively, during 2000-2010 compared to the 1950s. There existed two abrupt change points of the runoff in the Hekou-Longmen region and Huangfuchuan watershed, which were detected in 1979 and 1998. But in the Yanhe watershed only one abrupt change point was found in 1996. The precipitation elasticities of runoff were 1.11, 1.09, and 1.26, respectively, and the contributions of precipitation on runoff reduction were 26.4%, 17.9%, and 31.6%, respectively, in the Hekou-Longmen region, Huangfuchuan watershed, and Yanhe watershed.

  14. Assessment of transboundary environmental effects in the Pearl River Delta Region: Is there a role for strategic environmental assessment?

    International Nuclear Information System (INIS)

    Marsden, Simon

    2011-01-01

    China's EIA Law does not require transboundary proposals to be assessed, despite recognition of this globally, for example in the Espoo Convention and Kiev Protocol, and in the European EIA and SEA Directives. In a transboundary context assessment within a state is unusual, as regulating these effects is primarily about the relationship between states. However where a state has more than one legal system such as in the Pearl River Delta (PRD) Region of southern China, transboundary effects should also be addressed. Yet despite the geographical connections between Guangdong Province in mainland China (where the EIA Law applies) and the Hong Kong and Macau Special Administrative Regions (which have their own provisions, neither of which requires transboundary assessments), EIA and SEA are carried out separately. Coordinated or joint approaches to transboundary assessment are generally absent, with the legal autonomy of Hong Kong and Macau a major constraint. As a result institutional responses at the policy level have developed. The article considers global experiences with regulating transboundary EIA and SEA, and analyses potential application to land use, transport and air and water planning in the PRD Region. If applied, benefits may include prevention or mitigation of cumulative effects, broader public participation, and improvements to environmental governance. The PRD Region experience may encourage China to conduct and coordinate EIA and SEA processes with neighbouring states, which has been non-existent or extremely limited to date.

  15. [Process of land use transition and its impact on regional ecological quality in the Middle Reaches of Heihe River, China].

    Science.gov (United States)

    Wang, Fu Hong; Zhao, Rui Feng; Zhang, Li Hua; Li, Hong Wei

    2017-12-01

    Land use transition is one of the main drivers of regional ecosystem change in arid area, which directly affects human well-being. Based on the satellite images of 1987, 2001 and 2016, the change detection assessment model and ecological response model were used to analyze the process of land use transition and response of ecological quality during 1987-2016 in the ecologically fragile middle reaches of the Heihe River. The results showed that the land use change was significant during 1987-2016 and the total change increased significantly, as well as the continuous increase of the cultivated land and construction land. There was a strong tendency of transform from grassland to cultivated land, while the tendency of transforming unused land to other land classes was not strong under a random process of gain or loss. During 1987-2016, the ecological quality of the study area displayed a decreasing trend as a whole and the ecological land decreased by 2.8%. The land use transition with the greatest impact on the ecological environment degradation was the transition of the grassland to the cultivated land and unused land. Therefore, in order to promote the sustainable use of regional land resources and to improve the regional ecological quality, it is necessary to allocate the proportion of production land and ecological land according to the regional water resources.

  16. Regional water table (2016) in the Mojave River and Morongo groundwater basins, southwestern Mojave Desert, California

    Science.gov (United States)

    Dick, Meghan; Kjos, Adam

    2017-12-07

    From January to April 2016, the U.S. Geological Survey (USGS), the Mojave Water Agency, and other local water districts made approximately 1,200 water-level measurements in about 645 wells located within 15 separate groundwater basins, collectively referred to as the Mojave River and Morongo groundwater basins. These data document recent conditions and, when compared with older data, changes in groundwater levels. A water-level contour map was drawn using data measured in 2016 that shows the elevation of the water table and general direction of groundwater movement for most of the groundwater basins. Historical water-level data stored in the USGS National Water Information System (https://waterdata.usgs.gov/nwis/) database were used in conjunction with data collected for this study to construct 37 hydrographs to show long-term (1930–2016) and short-term (1990–2016) water-level changes in the study area.

  17. SECURITY RISKS, MYTHS IN A TRANSITIONING SUB-NATIONAL REGIONAL ECONOMY (CROSS RIVER STATE AND IMAGINATIVE GEOGRAPHIES OF NIGERIA

    Directory of Open Access Journals (Sweden)

    J. K. UKWAYI

    2015-03-01

    Full Text Available The emergence of an “international community” through accumulation of perceived risks that contrasts with those risks (of considerably lower levels of seriousness compared to those perceived constitutes one of the interesting (or intriguing subjects of risks and disaster studies surrounding the 9/11 era. The constructions of “imaginative geographies”, have frequently been biased in the practices that underlie the mapping of the foreign places tend to put-down the affected regions in their “paintings” for the global community. The latter are subsequently “demonized” in their ratings of competence for participating in world trade, tourism, travel, among other social/cultural, and economic and political activities. The objective of this article is to highlight how the exaggeration of risks (contrasted to actually existing/lived risks, practices that are frequently associated with such adverse “imaginative geographies” poses sub-national regional development dilemma in Nigeria’s Niger Delta. We trace the roots of adverse “imaginative geographies” of Nigeria to the Abacha dictatorship (1993-1997. Then we highlight the mixed characteristics of the Niger Delta conditions during the “return of positive image recapture” by Nigeria’s federal government (re-democratisation of the Fourth Republic, 1999-present, re-branding campaigns; as well as adverse conditions present. Most significantly, we show that despite these adversities, a combination of favorable geographical size, differentiation, sub-national regional security programme formulation and management taking aims at diversification have created “large oases” of peace and security in Cross River State, a part of the Niger Delta that has been completely unscathed by insurgencies of the nearby sub-national region and further away national origin. Apart from identifying sub-national regions qualifying for delisting from “adverse imaginative geographies” due to

  18. Distribution of polycyclic aromatic hydrocarbons in thirty typical soil profiles in the Yangtze River Delta region, east China

    International Nuclear Information System (INIS)

    Ping, L.F.; Luo, Y.M.; Zhang, H.B.; Li, Q.B.; Wu, L.H.

    2007-01-01

    Polycyclic aromatic hydrocarbons (PAHs) were quantified in 30 soil profiles from the Yangtze River Delta Region, in east China. Relative concentrations of PAH compounds with different benzene rings and ratios of fluoranthene to fluoranthene plus pyrene and benz(a)anthracene to benz(a)anthracene plus chrysene were used to identify the possible sources of soil PAHs. Total concentrations of 15 PAHs in topsoils ranged from 8.6 to 3881 μg kg -1 with an average of 397 μg kg -1 . Half of the soil samples were considered to be contaminated with PAHs (>200 μg kg -1 ) and two sampling sites were heavily polluted by PAHs with concentrations >1000 μg kg -1 . Phenanthrene was found in soils below a depth of 100 cm in half of the sampling sites, but the detectable ratio of benzo(a)pyrene decreased sharply from 100% in topsoil to 0 in the 4th horizon. - The information was provided on levels, distributions, and possible sources of PAHs in the soils of Yangtze River Delta area

  19. Regional evapotranspiration estimation based on a two-layer remote-sensing scheme in Shahe River basin

    International Nuclear Information System (INIS)

    Yin, Jian; Wang, Huixiao

    2014-01-01

    Land surface evapotranspiration (ET) derived from remote sensing data has significant meaning for plant growth monitoring, crop yield assessment, disaster monitoring and understanding energy and water cycle in river basin area and surrounding regions. In the study, we developed a land surface ET remote sensing retrieval system to estimate the daily ET in Shahe river basin using the TM/ETM+ images. The system is based on the two-layer ET model and includes three parts: inversion of the evaporation ration using two-layer model, calculation of total daily net radiation, and estimation of daily ET based on evaporation fraction method. The results show that the average daily ET is about 2.28mm of the typical days in spring, and 2.97mm in summer, 1.59mm in autumn, and 0.5mm in winter. The ET in upstream areas covered by forest is higher than that in the downstream covered by settlement and farmland. In summer the difference of ET between the upper reaches and lower reaches is smaller compared to the other three seasons. The measurements by large aperture scintillometer and eddy correlation instrument were used for validation. By comparing the observed data with the estimated data, we found the estimation system had a high precision with the relative error between 0 and 16% (mean error of 11.1%), and the variance 0.77mm

  20. Integrative taxonomy supports new candidate fish species in a poorly studied neotropical region: the Jequitinhonha River Basin.

    Science.gov (United States)

    Pugedo, Marina Lages; de Andrade Neto, Francisco Ricardo; Pessali, Tiago Casarim; Birindelli, José Luís Olivan; Carvalho, Daniel Cardoso

    2016-06-01

    Molecular identification through DNA barcoding has been proposed as a way to standardize a global biodiversity identification system using a partial sequence of the mitochondrial COI gene. We applied an integrative approach using DNA barcoding and traditional morphology-based bioassessment to identify fish from a neotropical region possessing low taxonomic knowledge: the Jequitinhonha River Basin (Southeastern Brazil). The Jequitinhonha River Basin (JRB) has a high rate of endemism and is considered an area of high priority for fish conservation, with estimates indicating the presence of around 110 native and non-indigenous species. DNA barcodes were obtained from 260 individuals belonging to 52 species distributed among 35 genera, 21 families and 6 orders, including threatened and rare species such as Rhamdia jequitinhonha and Steindachneridion amblyurum. The mean Kimura two-parameter genetic distances within species, genera and families were: 0.44, 12.16 and 20.58 %, respectively. Mean intraspecific genetic variation ranged from 0 to 11.43 %, and high values (>2 %) were recovered for five species. Species with a deep intraspecific distance, possibly flagging overlooked taxa, were detected within the genus Pimelodella. Fifteen species, only identified to the genus level, had unique BINs, with a nearest neighbor distance over 2 % and therefore, potential new candidate species supported by DNA barcoding. The integrative taxonomy approach using DNA barcoding and traditional taxonomy may be a remedy to taxonomy impediment, accelerating species identification by flagging potential new candidate species and to adequately conserve the megadiverse neotropical ichthyofauna.

  1. Assessment of climate change impact on hydrological extremes in two source regions of the Nile River Basin

    Directory of Open Access Journals (Sweden)

    M. T. Taye

    2011-01-01

    Full Text Available The potential impact of climate change was investigated on the hydrological extremes of Nyando River and Lake Tana catchments, which are located in two source regions of the Nile River basin. Climate change scenarios were developed for rainfall and potential evapotranspiration (ETo, considering 17 General Circulation Model (GCM simulations to better understand the range of possible future change. They were constructed by transferring the extracted climate change signals to the observed series using a frequency perturbation downscaling approach, which accounts for the changes in rainfall extremes. Projected changes under two future SRES emission scenarios A1B and B1 for the 2050s were considered. Two conceptual hydrological models were calibrated and used for the impact assessment. Their difference in simulating the flows under future climate scenarios was also investigated.

    The results reveal increasing mean runoff and extreme peak flows for Nyando catchment for the 2050s while unclear trend is observed for Lake Tana catchment for mean volumes and high/low flows. The hydrological models for Lake Tana catchment, however, performed better in simulating the hydrological regimes than for Nyando, which obviously also induces a difference in the reliability of the extreme future projections for both catchments. The unclear impact result for Lake Tana catchment implies that the GCM uncertainty is more important for explaining the unclear trend than the hydrological models uncertainty. Nevertheless, to have a better understanding of future impact, hydrological models need to be verified for their credibility of simulating extreme flows.

  2. Impact of city effluents on water quality of Indus River: assessment of temporal and spatial variations in the southern region of Khyber Pakhtunkhwa, Pakistan.

    Science.gov (United States)

    Khan, Ilham; Khan, Azim; Khan, Muhammad Sohail; Zafar, Shabnam; Hameed, Asma; Badshah, Shakeel; Rehman, Shafiq Ur; Ullah, Hidayat; Yasmeen, Ghazala

    2018-04-04

    The impact of city effluents on water quality of Indus River was assessed in the southern region of Khyber Pakhtunkhwa, Pakistan. Water samples were collected in dry (DS) and wet (WS) seasons from seven sampling zones along Indus River and the physical, bacteriological, and chemical parameters determining water quality were quantified. There were marked temporal and spatial variations in the water quality of Indus River. The magnitude of pollution was high in WS compared with DS. The quality of water varied across the sampling zones, and it greatly depended upon the nature of effluents entering the river. Water samples exceeded the WHO permissible limits for pH, EC, TDS, TS, TSS, TH, DO, BOD, COD, total coliforms, Escherichia coli, Ca 2+ , Mg 2+ , NO 3 - , and PO 4 2- . Piper analysis indicated that water across the seven sampling zones along Indus River was alkaline in nature. Correlation analyses indicated that EC, TDS, TS, TH, DO, BOD, and COD may be considered as key physical parameters, while Na + , K + , Ca 2+ , Mg 2+ , Cl - , F - , NO 3 - , PO 4 2- , and SO 4 2- as key chemical parameters determining water quality, because they were strongly correlated (r > 0.70) with most of the parameters studied. Cluster analysis indicated that discharge point at Shami Road is the major source of pollution impairing water quality of Indus River. Wastewater treatment plants must be installed at all discharge points along Indus River for protecting the quality of water of this rich freshwater resource in Pakistan.

  3. Simulation of the Regional Ground-Water-Flow System and Ground-Water/Surface-Water Interaction in the Rock River Basin, Wisconsin

    Science.gov (United States)

    Juckem, Paul F.

    2009-01-01

    A regional, two-dimensional, areal ground-water-flow model was developed to simulate the ground-water-flow system and ground-water/surface-water interaction in the Rock River Basin. The model was developed by the U.S. Geological Survey (USGS), in cooperation with the Rock River Coalition. The objectives of the regional model were to improve understanding of the ground-water-flow system and to develop a tool suitable for evaluating the effects of potential regional water-management programs. The computer code GFLOW was used because of the ease with which the model can simulate ground-water/surface-water interactions, provide a framework for simulating regional ground-water-flow systems, and be refined in a stepwise fashion to incorporate new data and simulate ground-water-flow patterns at multiple scales. The ground-water-flow model described in this report simulates the major hydrogeologic features of the modeled area, including bedrock and surficial aquifers, ground-water/surface-water interactions, and ground-water withdrawals from high-capacity wells. The steady-state model treats the ground-water-flow system as a single layer with hydraulic conductivity and base elevation zones that reflect the distribution of lithologic groups above the Precambrian bedrock and a regionally significant confining unit, the Maquoketa Formation. In the eastern part of the Basin where the shale-rich Maquoketa Formation is present, deep ground-water flow in the sandstone aquifer below the Maquoketa Formation was not simulated directly, but flow into this aquifer was incorporated into the GFLOW model from previous work in southeastern Wisconsin. Recharge was constrained primarily by stream base-flow estimates and was applied uniformly within zones guided by regional infiltration estimates for soils. The model includes average ground-water withdrawals from 1997 to 2006 for municipal wells and from 1997 to 2005 for high-capacity irrigation, industrial, and commercial wells. In addition

  4. Accumulation, transfer, and environmental risk of soil mercury in a rapidly industrializing region of the Yangtze River Delta, China

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Biao; Yan, Lianxiang; Sun, Weixia; Zhao, Yongcun; Shi, Xuezheng [Chinese Academy of Sciences, Nanjing (China). State Key Lab. of Soil and Sustainable Agriculture; Wang, Mei [Chinese Academy of Sciences, Nanjing (China). State Key Lab. of Soil and Sustainable Agriculture; Graduate Univ. of the Chinese Academy of Sciences, Beijing (China); Weindorf, David C. [Louisiana State Univ., Baton Rouge, LA (United States). AgCenter

    2011-06-15

    Purpose: Mercury (Hg) accumulation and transfer in soil ecosystems has been altered on local, regional, and even global scales, and their environmental risk has increasingly been a concern to the public and the scientific community. Materials and methods: A county level region in Zhangjiagang County, the Yangtze River Delta (YRD) region of China and a factory with Hg-contaminated wastewater discharging within the region were selected to study the accumulation, bioavailability, and transfer of Hg from different sources in soils and crops under rapid industrialization, urbanization, and intensive agricultural activities. Regional soil samples close to and away from factories and local soil and crop samples around a typical factory were collected in the YRD region of China. Soil and crop Hg and basic soil properties were examined. Results and discussion: Significant soil Hg accumulation was found in soils away from factories regardless of Cambosols (Entisols) and Anthrosols (Inceptisols), while the mobile HCl-extractable Hg (HCl-Hg) were greater in soils closer to factories due to a decrease and increase in soil pH and organic matter. A high level of soil total Hg (T-Hg) was found around the factory, and soil and crop Hg accumulation in the vicinity of the factory was localized with an exponential decrease as distance away from the wastewater discharge outlet increased. Although Hg accumulated in these soils, the T-Hg levels at only a few sampling sites in acidic Anthrosols area were found to exceed the second most stringent critical value of Chinese Environmental Quality Standards for Soils. Conclusions: Considering the cessation of Hg-containing agrochemicals and limitation of effects of industrial activities on Hg accumulation, more attention should be paid to the changes in soil properties and crop rotations than controlling the pathways of Hg entering soils because the current environmental risk is mobilization of accumulated soil Hg. (orig.)

  5. Alpine grassland soil organic carbon stock and its uncertainty in the three rivers source region of the Tibetan Plateau.

    Directory of Open Access Journals (Sweden)

    Xiaofeng Chang

    Full Text Available Alpine grassland of the Tibetan Plateau is an important component of global soil organic carbon (SOC stocks, but insufficient field observations and large spatial heterogeneity leads to great uncertainty in their estimation. In the Three Rivers Source Region (TRSR, alpine grasslands account for more than 75% of the total area. However, the regional carbon (C stock estimate and their uncertainty have seldom been tested. Here we quantified the regional SOC stock and its uncertainty using 298 soil profiles surveyed from 35 sites across the TRSR during 2006-2008. We showed that the upper soil (0-30 cm depth in alpine grasslands of the TRSR stores 2.03 Pg C, with a 95% confidence interval ranging from 1.25 to 2.81 Pg C. Alpine meadow soils comprised 73% (i.e. 1.48 Pg C of the regional SOC estimate, but had the greatest uncertainty at 51%. The statistical power to detect a deviation of 10% uncertainty in grassland C stock was less than 0.50. The required sample size to detect this deviation at a power of 90% was about 6-7 times more than the number of sample sites surveyed. Comparison of our observed SOC density with the corresponding values from the dataset of Yang et al. indicates that these two datasets are comparable. The combined dataset did not reduce the uncertainty in the estimate of the regional grassland soil C stock. This result could be mainly explained by the underrepresentation of sampling sites in large areas with poor accessibility. Further research to improve the regional SOC stock estimate should optimize sampling strategy by considering the number of samples and their spatial distribution.

  6. Investigating the Impacts of Landuse-landcover (LULC Change in the Pearl River Delta Region on Water Quality in the Pearl River Estuary and Hong Kong’s Coast

    Directory of Open Access Journals (Sweden)

    Hongyan Xi

    2009-11-01

    Full Text Available Water quality information in the coastal region of Hong Kong and the Pearl River Estuary (PRE is of great concern to the local community. Due to great landuse-landcover (LULC changes with rapid industrialization and urbanization in the Pearl River Delta (PRD region, water quality in the PRE has worsened during the last 20 years. Frequent red tide and harmful algal blooms have occurred in the estuary and its adjacent coastal waters since the 1980s and have caused important economic losses, also possibly threatening to the coastal environment, fishery, and public health in Hong Kong. In addition, recent literature shows that water nutrients in Victoria Harbor of Hong Kong have been proven to be strongly influenced by both the Pearl River and sewage effluent in the wet season (May to September, but it is still unclear how the PRE diluted water intrudes into Victoria Harbor. Due to the cloudy and rainy conditions in the wet season in Hong Kong, ASAR images will be used to monitor the PRE river plumes and track the intruding routes of PRE water nutrients. In this paper, we first review LULC change in the PRD and then show our preliminary results to analyze water quality spatial and temporal information from remote observations with different sensors in the coastal region and estuary. The study will also emphasizes on time series of analysis of LULC trends related to annual sediment yields and critical source areas of erosion for the PRD region since the 1980s.

  7. The presence of Praomys, Lophuromys, and Deomys species (Muridae, Mammalia) in the forest blocks separated by the Congo River and its tributaries (Kisangani region, Democratic Republic of Congo)

    DEFF Research Database (Denmark)

    Katuala, Pionus G B; Kennis, Jan; Nicolas, Violaine

    2008-01-01

    Praomys (four species), Lophuromys (four) and Deomys (one) are among the most common Muridae in the Kisangani region. To establish whether or not rivers constitute dispersal barriers for these rodents, we investigated the presence of these genera and their species in eight localities that are eit......Praomys (four species), Lophuromys (four) and Deomys (one) are among the most common Muridae in the Kisangani region. To establish whether or not rivers constitute dispersal barriers for these rodents, we investigated the presence of these genera and their species in eight localities...

  8. Report on airborne radioactivity surveys and the uranium deposits in the Red River region of Texas and Oklahoma

    International Nuclear Information System (INIS)

    Blair, R.G.; Stehle, F.T.; Levich, R.A.

    1973-11-01

    The U. S. Atomic Energy Commission conducted an airborne radioactivity survey of the Red River region of Texas and Oklahoma beginning in December 1955 and ending in May 1956. All or parts of Archer, Clay, and Montague Counties in northern Texas and Carter, Cotton, Jefferson, and Stephens Counties in southern Oklahoma were surveyed. Particular attention was paid to those areas where exposures are found of red beds of the Permian Wichita Group. Field examinations were conducted of anomalies discovered by airborne reconnaissance as well as those reported by private individuals. Forty localities were examined, the majority in sandstones, siltstones, or conglomerates. Uranium and copper minerals were identified at several localities. Ferruginous staining, bleaching of the sandstone color, calcium carbonate cement, and carbonized plant remains are common to the deposits

  9. Environmental changes and human work in the region of the Upper Paraná River floodplain: processes and interactions

    Directory of Open Access Journals (Sweden)

    EA. Tomanik

    Full Text Available The environment and society constitute a complex of elements and interactions. Thus, an understanding of the processes in which the environment and psychosocial elements are involved may not be gained from knowledge of just one isolated variable. Based on such premises, the present paper, which summarizes the results of a series of studies, adopts work relationships as its main focus, but in addition, it has two complementary objectives. One is to present some analyses on the interaction between human actions and the environmental changes that have been taking place in the region of the Upper Paraná River floodplain and in its boundaries. A secondary aim is to show how those two factors have been changing people's working and living conditions and the identity configuration of some of the human groups that live at that site.

  10. Influence of uranium and thorium in the natural radioactivity in shales from the middle Amazon river region

    International Nuclear Information System (INIS)

    Ferro, A.L.

    1982-02-01

    The feasibility of using the fission track registration technique in the determination of the uranium and thorium content in shales from the middle Amazon river region is studied. The above technique permits, through the determination of the uranium concentration, to establish a correlation between the uranium content and the organic matter present in the shale. In establishing the ratio between the fission tracks due to 238 U and 235 U, the sample was contaminated with natural uranium and analized, so that no modifications on the analysis conditions might change or distort the results. The experimental results were satisfactory and they may contribute to the study of the industrial exploration of these energy sources as well as to the analysis of problems related to environmental control. (Author) [pt

  11. Calcium and magnesium isotope systematics in rivers draining the Himalaya-Tibetan-Plateau region: Lithological or fractionation control?

    Science.gov (United States)

    Tipper, Edward T.; Galy, Albert; Bickle, Mike J.

    2008-02-01

    In rivers draining the Himalaya-Tibetan-Plateau region, the 26Mg/ 24Mg ratio has a range of 2‰ and the 44Ca/ 42Ca ratio has a range of 0.6‰. The average δ26Mg values of tributaries from each of the main lithotectonic units (Tethyan Sedimentary Series (TSS), High Himalayan Crystalline Series (HHCS) and Lesser Himalayan Series (LHS)) are within 2 standard deviation analytical uncertainty (0.14‰). The consistency of average riverine δ26Mg values is in contrast to the main rock types (limestone, dolostone and silicate) which range in their average δ26Mg values by more than 2‰. Tributaries draining the dolostones of the LHS differ in their δ44Ca values compared to tributaries from the TSS and HHCS. The chemistry of these river waters is strongly influenced by dolostone (solute Mg/Ca close to unity) and both δ26Mg (-1.31‰) and δ44Ca (0.64‰) values are within analytical uncertainty of the LHS dolostone. These are the most elevated δ44Ca values in rivers and rock reported so far demonstrating that both riverine and bedrock δ44Ca values may show greater variability than previously thought. Although rivers draining TSS limestone have the lowest δ26Mgandδ44Ca values at -1.41 and 0.42‰, respectively, both are offset to higher values compared to bedrock TSS limestone. The average δ26Mg value of rivers draining mainly silicate rock of the HHCS is -1.25‰, lower by 0.63‰ than the average silicate rock. These differences are consistent with a fractionation of δ26Mg values during silicate weathering. Given that the proportion of Mg exported from the Himalaya as solute Mg is small, the difference in 26Mg/ 24Mg ratios between silicate rock and solute Mg reflects the 26Mg/ 24Mg isotopic fractionation factor ( αsilicate-dissolvedMg) between silicate and dissolved Mg during incongruent silicate weathering. The value of αsilicate-dissolvedMg of 0.99937 implies that in the TSS, solute Mg is primarily derived from silicate weathering, whereas the source of Ca

  12. The first fossil skull of Alligator sinensis from the Pleistocene, Taiwan, with a paleogeographic implication of the species

    Science.gov (United States)

    Hsi-yin, Shan; Yen-nien, Cheng; Xiao-chun, Wu

    2013-06-01

    A nearly complete fossil skull of Alligatoridae from the Pleistocene, Penghu Channel, east of Taiwan, is reported. It can be referred to the most latest clade of Alligatorinae, which includes Alligator sinensis, Alligator mississippiensis and Alligator mefferdi, on the basis of the following features: the splenial is excluded from the mandibular symphysis; the anterior tip of the splenial passes dorsal to the Meckelian groove; and the mandible is gently curved between the fourth alveoli and the mid dentary. It differs from A. mississippiensis and A. mefferdi mainly in the following characters: the breadth between the supratemporal fenestrae is approximately equal to the interorbital width, the snout is about half the length of the skull; and the anterior part of the snout is subtriangular in dorsal view. These features suggest that the Penghu alligator is most probably referable to A. sinensis. This is the only fossil skull of A. sinensis known. The discovery of the skull in Penghu Channel not only provides the first solid fossil evidence to indicate that the geological distribution of A. sinensis extended farther southeast than the historical/archeological range of the species but also adds new information on the biodiversity of the Penghu fauna.

  13. Cold Lake-Beaver River water management study update: Report of the Cold Lake Regional Water Management Task Force

    International Nuclear Information System (INIS)

    1994-01-01

    The Cold Lake Regional Water Management Task Force was formed in 1992, comprising representatives from local governments, aboriginal groups, the oil industry, and the public. The Task Force's mandate was to advise Alberta Environmental Protection on updating the Cold Lake-Beaver River Water Management Plan, taking into acocunt the views and concerns of the public, industry, and local governments. Industrial water use was found to be the key issue to be addressed in the plan update, so the Task Force focused on reviewing industrial water supply options and developing recommendations on the appropriate water supply to meet long-term requirements. A subcommittee was established to monitor groundwater use by the heavy oil industry. This committee took readings at Imperial Oil's water production and observation wells on a biweekly basis. Nine options for supplying industrial water requirements were examined and evaluated using criteria including supply reliability, economic factors, and impacts on other users and the environment. The Task Force found that the preferred source of water for industrial use is the North Saskatchewan River, to be accessed by a water pipeline. The second and less desirable source of water for industrial use would be a system of weirs on Cold or Primrose Lakes and Wolf Lake, supplemented by the use of brackish water to the maximum extent possible. In the interim, industry was recommended to maximize its use of brackish water and continue to use surface and ground water within existing license limits. Other recommendations were to form provincial or regional boards to oversee water use and issue water licenses, to treat water as a resource, and to establish a fee for industrial use of water. 3 figs., 5 tabs

  14. Using an ensemble of regional climate models to assess climate change impacts on water scarcity in European river basins.

    Science.gov (United States)

    Gampe, David; Nikulin, Grigory; Ludwig, Ralf

    2016-12-15

    Climate change will likely increase pressure on the water balances of Mediterranean basins due to decreasing precipitation and rising temperatures. To overcome the issue of data scarcity the hydrological relevant variables total runoff, surface evaporation, precipitation and air temperature are taken from climate model simulations. The ensemble applied in this study consists of 22 simulations, derived from different combinations of four General Circulation Models (GCMs) forcing different Regional Climate Models (RCMs) and two Representative Concentration Pathways (RCPs) at ~12km horizontal resolution provided through the EURO-CORDEX initiative. Four river basins (Adige, Ebro, Evrotas and Sava) are selected and climate change signals for the future period 2035-2065 as compared to the reference period 1981-2010 are investigated. Decreased runoff and evaporation indicate increased water scarcity over the Ebro and the Evrotas, as well as the southern parts of the Adige and the Sava, resulting from a temperature increase of 1-3° and precipitation decrease of up to 30%. Most severe changes are projected for the summer months indicating further pressure on the river basins already at least partly characterized by flow intermittency. The widely used Falkenmark indicator is presented and confirms this tendency and shows the necessity for spatially distributed analysis and high resolution projections. Related uncertainties are addressed by the means of a variance decomposition and model agreement to determine the robustness of the projections. The study highlights the importance of high resolution climate projections and represents a feasible approach to assess climate impacts on water scarcity also in regions that suffer from data scarcity. Copyright © 2016. Published by Elsevier B.V.

  15. Risk Assessment on Dietary Exposure to Aflatoxin B1 in Post-Harvest Peanuts in the Yangtze River Ecological Region

    Science.gov (United States)

    Ding, Xiaoxia; Wu, Linxia; Li, Peiwu; Zhang, Zhaowei; Zhou, Haiyan; Bai, Yizhen; Chen, Xiaomei; Jiang, Jun

    2015-01-01

    Based on the 2983 peanut samples from 122 counties in six provinces of China’s Yangtze River ecological region collected between 2009–2014, along with the dietary consumption data in Chinese resident nutrition and health survey reports from 2002 and 2004, dietary aflatoxin exposure and percentiles in the corresponding statistics were calculated by non-parametric probability assessment, Monte Carlo simulation and bootstrap sampling methods. Average climatic conditions in the Yangtze River ecological region were calculated based on the data from 118 weather stations via the Thiessen polygon method. The survey results found that the aflatoxin contamination of peanuts was significantly high in 2013. The determination coefficient (R2) of multiple regression reflected by the aflatoxin B1 content with average precipitation and mean temperature in different periods showed that climatic conditions one month before harvest had the strongest impact on aflatoxin B1 contamination, and that Hunan and Jiangxi provinces were greatly influenced. The simulated mean aflatoxin B1 intake from peanuts at the mean peanut consumption level was 0.777–0.790 and 0.343–0.349 ng/(kg·d) for children aged 2–6 and standard adults respectively. Moreover, the evaluated cancer risks were 0.024 and 0.011/(100,000 persons·year) respectively, generally less than China’s current liver cancer incidence of 24.6 cases/(100,000 persons·year). In general, the dietary risk caused by peanut production and harvest was low. Further studies would focus on the impacts of peanut circulation and storage on aflatoxin B1 contamination risk assessment in order to protect peanut consumers’ safety and boost international trade. PMID:26501322

  16. Integrated Studies of a Regional Ozone Pollution Synthetically Affected by Subtropical High and Typhoon System in the Yangtze River Delta Region, China

    Science.gov (United States)

    Xie, M.; Shu, L.

    2017-12-01

    Severe high ozone (O3) episodes usually have close relations to synoptic systems. A regional continuous O3 pollution episode was detected over the Yangtze River Delta (YRD) region in China during August 7-12, 2013, in which the O3 concentrations in more than half of the cities exceeded the national air quality standard. By means of the observational analysis and the WRF/CMAQ numerical simulation, the characteristics and the essential impact factors of the typical regional O3 pollution are investigated. The observational analysis shows that the atmospheric subsidence dominated by Western Pacific subtropical high plays a crucial role in the formation of high-level O3. In addition, when the YRD cities at the front of Typhoon Utor, the periphery circulation of typhoon system can enhance the downward airflows and cause more serious air pollution. But when the typhoon system weakens the subtropical high, the prevailing southeasterly surface wind leads to the mitigation of the O3 pollution. The Integrated Process Rate (IPR) analysis incorporated in CMAQ is applied to further illustrate the combined influence of subtropical high and typhoon system in this O3 episode. The results show that the vertical diffusion (VDIF) and the gas-phase chemistry (CHEM) are two major contributors to O3 formation. On August 10-11, the cities close to the sea are apparently affected by the typhoon system, with the contribution of VDIF increasing to 28.45 ppb/h in Shanghai and 19.76 ppb/h in Hangzhou. When the YRD region is under the control of the typhoon system, the contribution values of all individual processes decrease to a low level in all cities. These results provide an insight for the O3 pollution synthetically impacted by the Western Pacific subtropical high and the tropical cyclone system.

  17. Statistical Seasonal Rainfall Forecast in the Neuquén River Basin (Comahue Region, Argentina

    Directory of Open Access Journals (Sweden)

    Marcela Hebe González

    2015-05-01

    Full Text Available A detailed statistical analysis was performed at the Neuquén river basin using precipitation data for 1980–2007. The hydrological year begins in March with a maximum in June associated with rainfall and another relative maximum in October derived from snow-break. General features of the rainy season and the excess or deficits thereof are analyzed using standardized precipitation index (SPI for a six-month period in the basin. The SPI has a significant cycle of 14.3 years; the most severe excess (SPI greater than 2 has a return period of 25 years, while the most severe droughts (SPI less than −2 have a return period of 10 years. The SPI corresponding to the rainy season (April–September (SPI9 has no significant trend and is used to classify wet/dry years. In order to establish the previous circulation patterns associated with interannual SPI9 variability, the composite fields of wet and dry years are compared. There is a tendency for wet (dry periods to take place during El Niño (La Niña years, when there are positive anomalies of precipitable water over the basin, when the zonal flow over the Pacific Ocean is weakened (intensified and/or when there are negative pressure anomalies in the southern part of the country and Antarctic sea. Some prediction schemes using multiple linear regressions were performed. One of the models derived using the forward stepwise method explained 42% of the SPI9 variance and retained two predictors related to circulation over the Pacific Ocean: one of them shows the relevance of the intensity of zonal flow in mid-latitudes, and the other is because of the influence of low pressure near the Neuquén River basin. The cross-validation used to prove model efficiency showed a correlation of 0.41 between observed and estimated SPI9; there was a probability of detection of wet (dry years of 80% (65% and a false alarm relation of 25% in both cases.

  18. Thermoregulation and temperature relations of alligators and other large ectotherms inhabiting thermally stressed habitats. Progress report, 1 October 1974--30 September 1977

    International Nuclear Information System (INIS)

    Spotila, J.R.

    1977-06-01

    Significant progress has been made in determining the mechanisms by which large ectotherms adjust to thermal stress in their natural environment. The effect of mouth gaping on head temperatures and the role of radiation, conduction and convection on body temperatures of alligators have been determined. The utility of energy budget modeling as a method for studying the thermoregulatory mechanisms of animals has been demonstrated. Steady state and time dependent models of body temperature have been tested. Convection coefficients and evaporative water loss rates have been measured for the turtle, Chysemys scripta. Climate space diagrams have been formulated and are being tested. Behavioral thermoregulation of turtles has been studied in PAR pond on the Savannah River Plant, Aiken, S.C. Steady state energy budget equations have been computed for largemouth bass. Experimental heat transfer coefficients indicate that most heat transfer is through the body wall and not via the gills. A time dependent model is being tested. It predicts the body temperature of a fish in a heterothermal environment. Theoretical calculations have been made of the effects of body size, color, and metabolism on the temperature regulation of ectotherms

  19. The Impact of the Aerosol Direct Radiative Forcing on Deep Convection and Air Quality in the Pearl River Delta Region

    Science.gov (United States)

    Liu, Z.; Yim, Steve H. L.; Wang, C.; Lau, N. C.

    2018-05-01

    Literature has reported the remarkable aerosol impact on low-level cloud by direct radiative forcing (DRF). Impacts on middle-upper troposphere cloud are not yet fully understood, even though this knowledge is important for regions with a large spatial heterogeneity of emissions and aerosol concentration. We assess the aerosol DRF and its cloud response in June (with strong convection) in Pearl River Delta region for 2008-2012 at cloud-resolving scale using an air quality-climate coupled model. Aerosols suppress deep convection by increasing atmospheric stability leading to less evaporation from the ground. The relative humidity is reduced in middle-upper troposphere due to induced reduction in both evaporation from the ground and upward motion. The cloud reduction offsets 20% of the aerosol DRF. The weaker vertical mixing further increases surface aerosol concentration by up to 2.90 μg/m3. These findings indicate the aerosol DRF impact on deep convection and in turn regional air quality.

  20. Rapid Global River Flood Risk Assessment under Climate and Socioeconomic Scenarios: An Extreme Case of Eurasian region

    Science.gov (United States)

    Kwak, Young-joo; Magome, Jun; Hasegawa, Akira; Iwami, Yoichi

    2017-04-01

    Causing widespread devastation with massive economic damage and loss of human lives, flood disasters hamper economic growth and accelerate poverty particularly in developing countries. Globally, this trend will likely continue due to increase in flood magnitude and lack of preparedness for extreme events. In line with risk reduction efforts since the early 21st century, the monitors and governors of global river floods should pay attention to international scientific and policy communities for support to facilitate evidence-based policy making with a special interest in long-term changes due to climate change and socio-economic effects. Although advanced hydrological inundation models and risk models have been developed to reveal flood risk, hazard, exposure, and vulnerability at a river basin, it is obviously hard to identify the distribution and locations of continent-level flood risk based on national-level data. Therefore, we propose a methodological possibility for rapid global flood risk assessment with the results from its application to the two periods, i.e., Present (from 1980 to 2004) and Future (from 2075 to 2099). The method is particularly designed to effectively simplify complexities of a hazard area by calculating the differential inundation depth using GFID2M (global flood inundation depth 2-dimension model), despite low data availability. In this research, we addressed the question of which parts in the Eurasian region (8E to 180E, 0N to 60N) can be found as high-risk areas in terms of exposed population and economy in case of a 50-year return period flood. Economic losses were estimated according to the Shared Socioeconomic Pathways (SSP) scenario, and the flood scale was defined using the annual maximum daily river discharge under the extreme conditions of climate change simulated with MRI-AGCM3.2S based on the Representative Concentration Pathways (RCP8.5) emissions scenario. As a preliminary result, the total potential economic loss in the

  1. Rethinking the longitudinal stream temperature paradigm: region-wide comparison of thermal infrared imagery reveals unexpected complexity of river temperatures

    Science.gov (United States)

    We used an extensive dataset of remotely sensed summertime river temperature to compare longitudinal profiles (temperature versus distance) for 54 rivers in the Pacific Northwest. We evaluated (1) how often profiles fit theoretical expectations of asymptotic downstream warming, a...

  2. Influence of synoptic condition and holiday effects on VOCs and ozone production in the Yangtze River Delta region, China

    Science.gov (United States)

    Xu, Zhengning; Huang, Xin; Nie, Wei; Chi, Xuguang; Xu, Zheng; Zheng, Longfei; Sun, Peng; Ding, Aijun

    2017-11-01

    Both anthropogenic emission and synoptic conditions play important roles in ozone (O3) formation and accumulation. In order to understand the influence of synoptic condition and holiday effects on ozone production in the Yangtze River Delta region, China, concentrations of speciated volatile organic compounds (VOCs) and O3 as well as other relevant trace gases were simultaneously measured at the Station for Observing Regional Processes of the Earth System (SORPES) in Nanjing around the National Day holidays of China in 2014, which featured substantial change of emissions and dominated by typical anti-cyclones. Different groups of VOC species and their chemical reactivities were comprehensively analyzed. We observed clear diurnal variations of short alkenes during the measurement period, considerable amount of short alkenes were observed during night (more than 10 ppb) while almost no alkenes were measured during daytime, which might be attributed to different chemical processes. The obvious enhancement of the VOC tracers during the National Day holidays (Oct. 1st-Oct. 7th) indicated that the holiday effect strongly influenced the distribution of VOC profile and chemical reactivity in the atmosphere. At the same time, two meso-scale anticyclone processes were also observed during the measurement period. The synoptic condition contributed to the accumulation of VOCs and other precursors, which consequently impacted the ozone production in this region. The integrated influence of synoptic and holiday effects was also analyzed with an Observation Based Model (OBM) based on simplified MCM (Master Chemical Mechanism) chemical mechanism. The calculated relative increment reactivity (RIR) of different VOC groups revealed that during the holidays, this region was in VOC-limited regime and the variation of RIR shows a close linkage to the development and elimination of anti-cyclones, indicating an in-negligible contribution of synoptic effect toward ozone production in this

  3. Geology and Geochemistry of the Poco de Fora region-Curaca river valley-Bahia-Brazil

    International Nuclear Information System (INIS)

    Figueiredo, M.C.H. de.

    1976-01-01

    In the Poco de Fora region level rocks of light metamorphism, from Caraiba group, corresponding to: - a meta-sedimentar sequence from Lower Pre-cambrian (Archean) - maphic-ultramaphic bodies with Fe and Cu sulphides of volcanogenic origin, and - sienitic ortho-gneiss. Geological, petrographic, geochemistry and geochronological studies were done. The sienitic-intrusion, from the upper crust, occur during the Archean-beginning of the Proterozoic. All the region was re-mobilized, and the sienitic was metamorphosed during Transamazonic Orogeny (2.200 to 1.800 m.y.). (C.D.G.) [pt

  4. The nitrogen cycle in highly urbanized tropical regions and the effect of river-aquifer interactions: The case of Jakarta and the Ciliwung River

    Science.gov (United States)

    Costa, Diogo; Burlando, Paolo; Priadi, Cindy; Shie-Yui, Liong

    2016-09-01

    Groundwater is extensively used in Jakarta to compensate for the limited public water supply network. Recent observations show a rise in nitrate (NO3-) levels in the shallow aquifer, thus pointing at a potential risk for public health. The detected levels are still below national and international regulatory limits for drinking water but a strategy is necessary to contain the growing problem. We combine 3 years of available data in the Ciliwung River, the major river flowing through Jakarta, with a distributed river-aquifer interaction model to characterise the impact of urbanisation on the N-cycle of both surface and groundwater systems. Results show that the N-cycle in the river-aquifer system is heterogeneous in space, seasonal dependent (i.e. flow regime) and strongly affected by urban pollution. Results suggest also that although the main sources of N related groundwater pollution are leaking septic tanks, the aquifer interaction with the Ciliwung River may locally have a strong effect on the concentrations. In the general context of pollution control in urban areas, this study demonstrates how advanced process-based models can be efficiently used in combination with field measurements to bring new insights into complex contamination problems. These are essential for more effective and integrated management of water quality in river-aquifer systems.

  5. Development of a global river-coastal coupling model and its application to flood simulation in Asian mega-delta regions

    Science.gov (United States)

    Ikeuchi, Hiroaki; Hirabayashi, Yukiko; Yamazaki, Dai; Muis, Sanne; Ward, Philip; Verlaan, Martin; Winsemius, Hessel; Kanae, Shinjiro

    2017-04-01

    The world's mega-delta regions and estuaries are susceptible to various water-related disasters, such as river flooding and storm surge. Moreover, simultaneous occurrence of them would be more devastating than a situation where they occur in isolation. Therefore, it is important to provide information about compound risks of fluvial and coastal floods at a large scale, both their statistical dependency as well as their combined resulting flooding in delta regions. Here we report on a first attempt to address this issue globally by developing a method to couple a global river model (CaMa-Flood) and a global tide and surge reanalysis (GTSR) dataset. A state-of-the-art global river routing model, CaMa-Flood, was modified to represent varying sea levels due to tides and storm surges as downstream boundary condition, and the GTSR dataset was post-processed to serve as inputs to the CaMa-Flood river routing simulation and a long-term simulation was performed to incorporate the temporal dependency between coastal tide and surge on the one hand, and discharge on the other. The coupled model was validated against observations, showing better simulation results of water levels in deltaic regions than simulation without GTSR. For example in the Ganges Delta, correlation coefficients were increased by 0.06, and root mean square errors were reduced by 0.22 m. Global coupling simulations revealed that storm surges affected river water levels in coastal regions worldwide, especially in low-lying flat areas with increases in water level larger than 0.5 m. By employing enhanced storm surge simulation with tropical storm tracks, we also applied the model to examine impacts of past hurricane and cyclone storm events on river flood inundation.

  6. EFFECT OF ACUTE STRESS ON PLASMA CONCENTRATIONS OF SEX AND STRESS HORMONES IN JUVENILE ALLIGATORS LIVING IN CONTROL AND CONTAMINATED LAKES

    Science.gov (United States)

    Environmental contaminants can act as stressors, inducing elevated circulating concentrations of stress hormones such as corticosterone and cortisol. Development in contaminated eggs has been reported to modify circulating sex steroid hormone concentrations in alligators (Alligat...

  7. Estimation of reservoir inflow in data scarce region by using Sacramento rainfall runoff model - A case study for Sittaung River Basin, Myanmar

    Science.gov (United States)

    Myo Lin, Nay; Rutten, Martine

    2017-04-01

    The Sittaung River is one of four major rivers in Myanmar. This river basin is developing fast and facing problems with flood, sedimentation, river bank erosion and salt intrusion. At present, more than 20 numbers of reservoirs have already been constructed for multiple purposes such as irrigation, domestic water supply, hydro-power generation, and flood control. The rainfall runoff models are required for the operational management of this reservoir system. In this study, the river basin is divided into (64) sub-catchments and the Sacramento Soil Moisture Accounting (SAC-SMA) models are developed by using satellite rainfall and Geographic Information System (GIS) data. The SAC-SMA model has sixteen calibration parameters, and also uses a unit hydrograph for surface flow routing. The Sobek software package is used for SAC-SMA modelling and simulation of river system. The models are calibrated and tested by using observed discharge and water level data. The statistical results show that the model is applicable to use for data scarce region. Keywords: Sacramento, Sobek, rainfall runoff, reservoir

  8. Impact of {sup 210}PB from Osamu Utsumi mine on sediment of rivers in Caldas Region, Minas Gerais

    Energy Technology Data Exchange (ETDEWEB)

    Dutra, Pedro Henrique; Menezes, Maria Angela B.C. de; Moreira, Rubens Martins; Carvalho Filho, Carlos Alberto de, E-mail: phd@cdtn.br, E-mail: menezes@cdtn.br, E-mail: rubens@cdtn.br, E-mail: cacf@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2013-07-01

    The Osamu Utsumi Mine of the Industrias Nucleares do Brasil (INB) is located in Caldas region, Minas Gerais, Brazil. It is a uranium mining and is in process of shutdown, decommissioning stage. CDTN/CNEN (Nuclear Technology Development Center, sponsored by Brazilian Commission for Nuclear Energy) is participating in this decommission step. One contribution will be the characterization of the environmental liability, determining the impact on the environment caused by mining activities. Several radionuclides are being analysed in diversified matrixes, however, this paper is about determination of {sup 210}Pb in sediment of rivers. One reason to analyse {sup 210}Pb is due to its long half-life (22.3 years) that may point out the carrier of {sup 222}Rn, {sup 226}Ra, {sup 228}Ra, even U, in the region. Besides, it may be used to date sediment. The methodology applied to determine the {sup 210}Pb activity in sediment was gamma spectrometry that was established at CDTN during the development of this study. The results confirmed the impact of the uranium mining on the environment. (author)

  9. [Prediction and simulation of urban area expansion in Pearl River Delta Region under the RCPs climate scenarios].

    Science.gov (United States)

    Jiang, Oun-ou; Deng, Xiang-zheng; Ke, Xin-li; Zhao, Chun-hong; Zhang, Wei

    2014-12-01

    The sizes and number of cities in China are increasing rapidly and complicated changes of urban land use system have occurred as the social economy develops rapidly. This study took the urban agglomeration of Pearl River Delta Region as the study area to explore the driving mechanism of dynamic changes of urban area in the urbanization process under the joint influence of natural environment and social economic conditions. Then the CA (cellular automata) model was used to predict and simulate the urban area changes until 2030 under the designed scenarios of planning and RCPs (representative concentration pathways). The results indicated that urbanization was mainly driven by the non-agricultural population growth and social-economic development, and the transportation had played a fundamental role in the whole process, while the areas with high elevation or steep slope restricted the urbanization. Besides, the urban area would keep an expanding trend regardless of the scenarios, however, the expanding speed would slow down with different inflection points under different scenarios. The urban expansion speed increased in the sequence of the planning scenario, MESSAGE scenario and AIM scenario, and that under the MESSAGE climate scenario was more consistent with the current urban development trend. In addition, the urban expansion would mainly concentrate in regions with the relatively high urbanization level, e.g., Guangzhou, Dongguan, Foshan, Shenzhen, Zhanjiang and Chaoshan.

  10. Impact of 210PB from Osamu Utsumi mine on sediment of rivers in Caldas Region, Minas Gerais

    International Nuclear Information System (INIS)

    Dutra, Pedro Henrique; Menezes, Maria Angela B.C. de; Moreira, Rubens Martins; Carvalho Filho, Carlos Alberto de

    2013-01-01

    The Osamu Utsumi Mine of the Industrias Nucleares do Brasil (INB) is located in Caldas region, Minas Gerais, Brazil. It is a uranium mining and is in process of shutdown, decommissioning stage. CDTN/CNEN (Nuclear Technology Development Center, sponsored by Brazilian Commission for Nuclear Energy) is participating in this decommission step. One contribution will be the characterization of the environmental liability, determining the impact on the environment caused by mining activities. Several radionuclides are being analysed in diversified matrixes, however, this paper is about determination of 210 Pb in sediment of rivers. One reason to analyse 210 Pb is due to its long half-life (22.3 years) that may point out the carrier of 222 Rn, 226 Ra, 228 Ra, even U, in the region. Besides, it may be used to date sediment. The methodology applied to determine the 210 Pb activity in sediment was gamma spectrometry that was established at CDTN during the development of this study. The results confirmed the impact of the uranium mining on the environment. (author)

  11. From fresh to marine waters: characterization and fate of dissolved organic matter in the Lena River delta region, Siberia

    Directory of Open Access Journals (Sweden)

    Rafael eGonçalves-Araujo

    2015-12-01

    Full Text Available Connectivity between the terrestrial and marine environment in the Artic is changing as a result of climate change, influencing both freshwater budgets and the supply of carbon to the sea. This study characterizes the optical properties of dissolved organic matter (DOM within the Lena Delta region and evaluates the behavior of DOM across the fresh water-marine gradient. Six fluorescent components (four humic-like; one marine humic-like; one protein-like were identified by Parallel Factor Analysis (PARAFAC with a clear dominance of allochthonous humic-like signals. Colored DOM (CDOM and dissolved organic carbon (DOC were highly correlated and had their distribution coupled with hydrographical conditions. Higher DOM concentration and degree of humification were associated with the low salinity waters of the Lena River. Values decreased towards the higher salinity Laptev Sea shelf waters. Results demonstrate different responses of DOM mixing in relation to the vertical structure of the water column, as reflecting the hydrographical dynamics in the region. Two mixing curves for DOM were apparent. In surface waters above the pycnocline there was a sharper decrease in DOM concentration in relation to salinity indicating removal. In the bottom water layer the DOM decrease within salinity was less. We propose there is a removal of DOM occurring primarily at the surface layer, which is likely driven by photodegradation and flocculation.

  12. Hydrological Impacts of Land Use Change and Climate Variability in the Headwater Region of the Heihe River Basin, Northwest China

    Science.gov (United States)

    Zhang, Ling; Nan, Zhuotong; Xu, Yi; Li, Shuo

    2016-01-01

    Land use change and climate variability are two key factors impacting watershed hydrology, which is strongly related to the availability of water resources and the sustainability of local ecosystems. This study assessed separate and combined hydrological impacts of land use change and climate variability in the headwater region of a typical arid inland river basin, known as the Heihe River Basin, northwest China, in the recent past (1995–2014) and near future (2015–2024), by combining two land use models (i.e., Markov chain model and Dyna-CLUE) with a hydrological model (i.e., SWAT). The potential impacts in the near future were explored using projected land use patterns and hypothetical climate scenarios established on the basis of analyzing long-term climatic observations. Land use changes in the recent past are dominated by the expansion of grassland and a decrease in farmland; meanwhile the climate develops with a wetting and warming trend. Land use changes in this period induce slight reductions in surface runoff, groundwater discharge and streamflow whereas climate changes produce pronounced increases in them. The joint hydrological impacts are similar to those solely induced by climate changes. Spatially, both the effects of land use change and climate variability vary with the sub-basin. The influences of land use changes are more identifiable in some sub-basins, compared with the basin-wide impacts. In the near future, climate changes tend to affect the hydrological regimes much more prominently than land use changes, leading to significant increases in all hydrological components. Nevertheless, the role of land use change should not be overlooked, especially if the climate becomes drier in the future, as in this case it may magnify the hydrological responses. PMID:27348224

  13. Hydrological Impacts of Land Use Change and Climate Variability in the Headwater Region of the Heihe River Basin, Northwest China.

    Science.gov (United States)

    Zhang, Ling; Nan, Zhuotong; Xu, Yi; Li, Shuo

    2016-01-01

    Land use change and climate variability are two key factors impacting watershed hydrology, which is strongly related to the availability of water resources and the sustainability of local ecosystems. This study assessed separate and combined hydrological impacts of land use change and climate variability in the headwater region of a typical arid inland river basin, known as the Heihe River Basin, northwest China, in the recent past (1995-2014) and near future (2015-2024), by combining two land use models (i.e., Markov chain model and Dyna-CLUE) with a hydrological model (i.e., SWAT). The potential impacts in the near future were explored using projected land use patterns and hypothetical climate scenarios established on the basis of analyzing long-term climatic observations. Land use changes in the recent past are dominated by the expansion of grassland and a decrease in farmland; meanwhile the climate develops with a wetting and warming trend. Land use changes in this period induce slight reductions in surface runoff, groundwater discharge and streamflow whereas climate changes produce pronounced increases in them. The joint hydrological impacts are similar to those solely induced by climate changes. Spatially, both the effects of land use change and climate variability vary with the sub-basin. The influences of land use changes are more identifiable in some sub-basins, compared with the basin-wide impacts. In the near future, climate changes tend to affect the hydrological regimes much more prominently than land use changes, leading to significant increases in all hydrological components. Nevertheless, the role of land use change should not be overlooked, especially if the climate becomes drier in the future, as in this case it may magnify the hydrological responses.

  14. Evaluation of regional-scale water level simulations using various river routing schemes within a hydrometeorological modelling framework for the preparation of the SWOT mission

    Science.gov (United States)

    Häfliger, V.; Martin, E.; Boone, A. A.; Habets, F.; David, C. H.; Garambois, P. A.; Roux, H.; Ricci, S. M.; Thévenin, A.; Berthon, L.; Biancamaria, S.

    2014-12-01

    The ability of a regional hydrometeorological model to simulate water depth is assessed in order to prepare for the SWOT (Surface Water and Ocean Topography) mission that will observe free surface water elevations for rivers having a width larger than 50/100 m. The Garonne river (56 000 km2, in south-western France) has been selected owing to the availability of operational gauges, and the fact that different modeling platforms, the hydrometeorological model SAFRAN-ISBA-MODCOU and several fine scale hydraulic models, have been extensively evaluated over two reaches of the river. Several routing schemes, ranging from the simple Muskingum method to time-variable parameter kinematic and diffusive waves schemes with time varying parameters, are tested using predetermined hydraulic parameters. The results show that the variable flow velocity scheme is advantageous for discharge computations when compared to the original Muskingum routing method. Additionally, comparisons between water level computations and in situ observations led to root mean square errors of 50-60 cm for the improved Muskingum method and 40-50 cm for the kinematic-diffusive wave method, in the downstream Garonne river. The error is larger than the anticipated SWOT resolution, showing the potential of the mission to improve knowledge of the continental water cycle. Discharge computations are also shown to be comparable to those obtained with high-resolution hydraulic models over two reaches. However, due to the high variability of river parameters (e.g. slope and river width), a robust averaging method is needed to compare the hydraulic model outputs and the regional model. Sensitivity tests are finally performed in order to have a better understanding of the mechanisms which control the key hydrological processes. The results give valuable information about the linearity, Gaussianity and symetry of the model, in order to prepare the assimilation of river heights in the model.

  15. Future changes in peak river flows across northern Eurasia as inferred from an ensemble of regional climate projections under the IPCC RCP8.5 scenario

    Science.gov (United States)

    Shkolnik, Igor; Pavlova, Tatiana; Efimov, Sergey; Zhuravlev, Sergey

    2018-01-01

    Climate change simulation based on 30-member ensemble of Voeikov Main Geophysical Observatory RCM (resolution 25 km) for northern Eurasia is used to drive hydrological model CaMa-Flood. Using this modeling framework, we evaluate the uncertainties in the future projection of the peak river discharge and flood hazard by 2050-2059 relative to 1990-1999 under IPCC RCP8.5 scenario. Large ensemble size, along with reasonably high modeling resolution, allows one to efficiently sample natural climate variability and increase our ability to predict future changes in the hydrological extremes. It has been shown that the annual maximum river discharge can almost double by the mid-XXI century in the outlets of major Siberian rivers. In the western regions, there is a weak signal in the river discharge and flood hazard, hardly discernible above climate variability. Annual maximum flood area is projected to increase across Siberia mostly by 2-5% relative to the baseline period. A contribution of natural climate variability at different temporal scales to the uncertainty of ensemble prediction is discussed. The analysis shows that there expected considerable changes in the extreme river discharge probability at locations of the key hydropower facilities. This suggests that the extensive impact studies are required to develop recommendations for maintaining regional energy security.

  16. CONFLICT OF AQUATIC RESOURCES AND ITS UNDERLYING CAUSES: A CASE STUDY FROM DONAN RIVER AREA, SEGARA ANAKAN REGION, CILACAP, CENTRAL JAVA

    Directory of Open Access Journals (Sweden)

    Taufik Budhi Pramono

    2009-04-01

    Full Text Available This research aimed to know internally conflict on the use of aquatic  resources at around Donan River, Segara Anakan region Cilacap.  Using on fisheries resources was not free against potential conflict among the user or with its interest’s one related to that resources.  The lack on capability of identified conflict would be a limiting factor for the implementation on the fisheries resources management program.  The research was hold in the region of Segara Anakan, Donan River from August until October 2005.  The data collection techniques applied in this survey included questionnaire; observation; in-depth interview with leaders of fisherman organizations; and focus group discussion. Quantitative data was analyzed by descriptive statistics.  The research showed that fisherman’s community along Donan River line were not out of inside potentially conflict among inter micro-micro, intra micro-micro and intra micro-macro.  This potential conflict were appeared because of presence on the different perception belong to its authority access against Donan River and their open system on the fisheries resources management.Keywords : Conflict, Donan River, Aquatic Resources, Fisherman Community

  17. Effects of recent volcanic eruptions on aquatic habitat in the Drift River, Alaska, USA: Implications at other Cook Inlet region volcanoes

    Science.gov (United States)

    Dorava, J.M.; Milner, A.M.

    1999-01-01

    Numerous drainages supporting productive salmon habitat are surrounded by active volcanoes on the west side of Cook Inlet in south-central Alaska. Eruptions have caused massive quantities of flowing water and sediment to enter the river channels emanating from glaciers and snowfields on these volcanoes. Extensive damage to riparian and aquatic habitat has commonly resulted, and benthic macroinvertebrate and salmonid communities can be affected. Because of the economic importance of Alaska's fisheries, detrimental effects on salmonid habitat can have significant economic implications. The Drift River drains glaciers on the northern and eastern flanks of Redoubt Volcano: During and following eruptions in 1989-1990, severe physical disturbances to the habitat features of the river adversely affected the fishery. Frequent eruptions at other Cook Inlet region volcanoes exemplify the potential effects of volcanic activity on Alaska's important commercial, sport, and subsistence fisheries. Few studies have documented the recovery of aquatic habitat following volcanic eruptions. The eruptions of Redoubt Volcano in 1989-1990 offered an opportunity to examine the recovery of the macroinvertebrate community. Macroinvertebrate community composition and structure in the Drift River were similar in both undisturbed and recently disturbed sites. Additionally, macroinvertebrate samples from sites in nearby undisturbed streams were highly similar to those from some Drift River sites. This similarity and the agreement between the Drift River macroinvertebrate community composition and that predicted by a qualitative model of typical macroinvertebrate communities in glacier-fed rivers indicate that the Drift River macroinvertebrate community is recovering five years after the disturbances associated with the most recent eruptions of Redoubt Volcano.

  18. RESEARCH: Effects of Recent Volcanic Eruptions on Aquatic Habitat in the Drift River, Alaska, USA: Implications at Other Cook Inlet Region Volcanoes.

    Science.gov (United States)

    DORAVA; MILNER

    1999-02-01

    / Numerous drainages supporting productive salmon habitat are surrounded by active volcanoes on the west side of Cook Inlet in south-central Alaska. Eruptions have caused massive quantities of flowing water and sediment to enter the river channels emanating from glaciers and snowfields on these volcanoes. Extensive damage to riparian and aquatic habitat has commonly resulted, and benthic macroinvertebrate and salmonid communities can be affected. Because of the economic importance of Alaska's fisheries, detrimental effects on salmonid habitat can have significant economic implications. The Drift River drains glaciers on the northern and eastern flanks of Redoubt Volcano. During and following eruptions in 1989-1990, severe physical disturbances to the habitat features of the river adversely affected the fishery. Frequent eruptions at other Cook Inlet region volcanoes exemplify the potential effects of volcanic activity on Alaska's important commercial, sport, and subsistence fisheries. Few studies have documented the recovery of aquatic habitat following volcanic eruptions. The eruptions of Redoubt Volcano in 1989-1990 offered an opportunity to examine the recovery of the macroinvertebrate community. Macroinvertebrate community composition and structure in the Drift River were similar in both undisturbed and recently disturbed sites. Additionally, macroinvertebrate samples from sites in nearby undisturbed streams were highly similar to those from some Drift River sites. This similarity and the agreement between the Drift River macroinvertebrate community composition and that predicted by a qualitative model of typical macroinvertebrate communities in glacier-fed rivers indicate that the Drift River macroinvertebrate community is recovering five years after the disturbances associated with the most recent eruptions of Redoubt Volcano. KEY WORDS: Aquatic habitat; Volcanoes; Lahars; Lahar-runout flows; Macroinvertebrates; Community structure; Community composition

  19. Distribution and mobility of mercury in soils of a gold mining region, Cuyuni river basin, Venezuela.

    Science.gov (United States)

    Santos-Francés, F; García-Sánchez, A; Alonso-Rojo, P; Contreras, F; Adams, M

    2011-04-01

    An extensive and remote gold mining region located in the East of Venezuela has been studied with the aim of assessing the distribution and mobility of mercury in soil and the level of Hg pollution at artisanal gold mining sites. To do so, soils and pond sediments were sampled at sites not subject to anthropological influence, as well as in areas affected by gold mining activities. Total Hg in regionally distributed soils ranged between 0.02 mg kg(-1) and 0.40 mg kg(-1), with a median value of 0.11 mg kg(-1), which is slightly higher than soil Hg worldwide, possibly indicating long-term atmospheric input or more recent local atmospheric input, in addition to minor lithogenic sources. A reference Hg concentration of 0.33 mg kg(-1) is proposed for the detection of mining affected soils in this region. Critical total Hg concentrations were found in the surrounding soils of pollutant sources, such as milling-amalgamation sites, where soil Hg contents ranged from 0.16 mg kg(-1) to 542 mg kg(-1) with an average of 26.89 mg kg(-1), which also showed high levels of elemental Hg, but quite low soluble+exchangeable Hg fraction (0.02-4.90 mg kg(-1)), suggesting low Hg soil mobility and bioavailability, as confirmed by soil column leaching tests. The vertical distribution of Hg through the soil profiles, as well as variations in soil Hg contents with distance from the pollution source, and Hg in pond mining sediments were also analysed. Copyright © 2010 Elsevier Ltd. All rights reserved.

  20. Dealing with regional hydrologic data-base limitations. Case example: the Columbia River basalts

    International Nuclear Information System (INIS)

    Schalla, R.; Leonhart, L.S.

    1981-01-01

    Limitations are encountered in assembling hydrologic data for a broad geographic region, such as the Columbia Plateau in the northwestern US, into a conceptual model of the hydrologic system. These limitations may become resonant in subsequent numerical simulations of hydrologic system behavior. Included among such data limitations are irregular spatial distributions of data, decreases in information with increasing depth from the land surface, uncertainties about the reliability of reported hydrologic data, disparities in time-dependent parameters, and lack of field verification of data. The preparation of a regional hydrologic system description, therefore, first involves a comprehensive data evaluation, wherein the data are classified and ranked in terms of their utility to the study. The results of this evaluation are essential in planning future data acquisition activities, as well as in selecting and developing models. In turn, iterative use of modeling, data refinement, and data acquisition is considered to be highly effective. The case example of preparing a hydrologic system description for the Columbia Plateau, as required for repository siting, illustrates methods of determining the accuracy of certain data, compensating for data limitations, evaluating the need for acquiring additional data, and refining data through iterative techniques. Emphasis is placed on professional subjectivity, which has proven to be essential in data base evaluation and refinement

  1. The Contribution of the Future SWOT Mission to Improve Simulations of River Stages and Stream-Aquifer Interactions at Regional Scale

    Science.gov (United States)

    Saleh, Firas; Filipo, Nicolas; Biancamaria, Sylvain; Habets, Florence; Rodriguez, Enersto; Mognard, Nelly

    2013-09-01

    The main objective of this study is to provide a realistic simulation of river stage in regional river networks in order to improve the quantification of stream-aquifer exchanges and better assess the associated aquifer responses that are often impacted by the magnitude and the frequency of the river stage fluctuations. This study extends the earlier work to improve the modeling of the Seine basin with a focus on simulating the hydrodynamics behavior of the Bassée alluvial wetland, a 120 km reach of the Seine River valley located south- east of Paris. The Bassée is of major importance for the drinking-water supply of Paris and surroundings, in addition to its particular hydrodynamic behavior due to the presence of a number of gravels. In this context, the understanding of stream-aquifer interactions is required for water quantity and quality preservation. A regional distributed process-based hydro(geo)logical model, Eau-Dyssée, is used. It aims at the integrated modeling of the hydrosystem to manage the various elements involved in the quantitative and qualitative aspects of water resources. Eau-Dyssée simulates pseudo 3D flow in aquifer systems solving the diffusivity equation with a finite difference numerical scheme. River flow is simulated with a Muskingum model. In addition to the in-stream discharge, a river stage estimate is needed to calculate the water exchange at the stream-aquifer interface using a conductance model. In this context, the future SWOT mission and its high-spatial resolution imagery can provide surface water level measurements at the regional scale that will permit to better characterize the Bassée complex hydro(geo)logical system and better assess soil water content. Moreover, the Bassée is considered as a potential target for the framework of the AirSWOT airborne campaign in France, 2013.

  2. Detection and attribution of climate change at regional scale: case study of Karkheh river basin in the west of Iran

    Science.gov (United States)

    Zohrabi, Narges; Goodarzi, Elahe; Massah Bavani, Alireza; Najafi, Husain

    2017-11-01

    This research aims at providing a statistical framework for detection and attribution of climate variability and change at regional scale when at least 30 years of observation data are available. While extensive research has been done on detecting significant observed trends in hydroclimate variables and attribution to anthropogenic greenhouse gas emissions in large continents, less attention has been paid for regional scale analysis. The latter is mainly important for adaptation to climate change in different sectors including but not limited to energy, agriculture, and water resources planning and management, and it is still an open discussion in many countries including the West Asian ones. In the absence of regional climate models, an informative framework is suggested providing useful insights for policymakers. It benefits from general flexibility, not being computationally expensive, and applying several trend tests to analyze temporal variations in temperature and precipitation (gradual and step changes). The framework is implemented for a very important river basin in the west of Iran. In general, some increasing and decreasing trends of the interannual precipitation and temperature have been detected. For precipitation annual time series, a reducing step was seen around 1996 compared with the gradual change in most of the stations, which have not experience a dramatical change. The range of natural forcing is found to be ±76 % for precipitation and ±1.4 °C for temperature considering a two-dimensional diagram of precipitation and temperature anomalies from 1000-year control run of global climate model (GCM). Findings out of applying the proposed framework may provide useful insights into how to approach structural and non-structural climate change adaptation strategies from central governments.

  3. Estimation of health and economic costs of air pollution over the Pearl River Delta region in China.

    Science.gov (United States)

    Lu, Xingcheng; Yao, Teng; Fung, Jimmy C H; Lin, Changqing

    2016-10-01

    The Pearl River Delta region (PRD) is the economic growth engine of China and also one of the most urbanized regions in the world. As a two-sided sword, rapid economic development causes air pollution and poses adverse health effects to the citizens in this area. This work estimated the negative health effects in the PRD caused by the four major ambient pollutants (SO2, NO2, O3 and PM10) from 2010 to 2013 by using a log linear exposure-response function and the WRF-CMAQ modeling system. Economic loss due to mortality and morbidity was evaluated by the value of statistical life (VSL) and cost of illness (COI) methods. The results show that the overall possible short-term all-cause mortality due to NO2, O3 and PM10 reached the highest in 2013 with the values being 13,217-22,800. The highest total economic loss, which ranged from 14,768 to 25,305million USD, occurred in 2013 and was equivalent to 1.4%-2.3% of the local gross domestic product. The monthly profile of cases of negative health effects varied by city and the types of ambient pollutants. The ratio of mortality attributed to air pollutants to total population was higher in urban areas than in rural areas. People living in the countryside should consider the possible adverse health effects of urban areas before they plan a move to the city. The results show that the health burden caused by the ambient pollutants over this region is serious and suggest that tighter control policies should be implemented in the future to reduce the level of air pollution. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Analysis on the Change of Grassland Coverage in the Source Region of Three Rivers during 2000-2012

    International Nuclear Information System (INIS)

    Luo, Chengfeng; Wang, Jiao; Liu, Meilin; Liu, Zhengjun

    2014-01-01

    The Source Region of Three Rivers (SRTR) has very important ecological functions which form an ecological security barrier for China's Qinghai-Tibet plateau. As the biggest nationally occuring nature reserve region in China, the ecological environment here is very fragile. In SRTR the grassland coverage is an effective detector to reflect the ecological environment condition, because it records the changing process of climatic and environmental sensitively. In recent years SRTR has been suffering pressures from both nature and social pressures. With MODIS data the study monitored the grassland coverage continuously in SRTR from 2000 to 2012. The density-model was adapted to estimate grassland coverage degree firstly. Then the degree of change and the change intensity, change type were used to judge the grassland coverage change trend comprehensively. For grassland coverage there was natural change annual or within the year, and the degree of change was used to judge if there was change or not. The grassland has another important characteristic, annual fluctuation, and it can be differed from sustained changes with change type. For grassland coverage, such continuous change, like improvement or degradation, and to what extent, has more guidance sense on specific production practice. On the base of change type and degree of change, change intensity was used to identify the change trend of the grassland coverage. The analysis results from our study show that steady state and fluctuation are two main change trends for the vegetation coverage in SRTR from 2000 to 2012. The conclusion of this paper can provide references in response to environment change research and in the regional ecological environmental protection project in SRTR

  5. Integrated studies of a regional ozone pollution synthetically affected by subtropical high and typhoon system in the Yangtze River Delta region, China

    Directory of Open Access Journals (Sweden)

    L. Shu

    2016-12-01

    Full Text Available Severe high ozone (O3 episodes usually have close relations to synoptic systems. A regional continuous O3 pollution episode was detected over the Yangtze River Delta (YRD region in China during 7–12 August 2013, in which the O3 concentrations in more than half of the cities exceeded the national air quality standard. The maximum hourly concentration of O3 reached 167.1 ppb. By means of the observational analysis and the numerical simulation, the characteristics and the essential impact factors of the typical regional O3 pollution are comprehensively investigated. The observational analysis shows that the atmospheric subsidence dominated by the western Pacific subtropical high plays a crucial role in the formation of high-level O3. The favorable weather conditions, such as extremely high temperature, low relative humidity and weak wind speed, caused by the abnormally strong subtropical high are responsible for the trapping and the chemical production of O3 in the boundary layer. In addition, when the YRD cities are at the front of Typhoon Utor, the periphery circulation of typhoon system can enhance the downward airflows and cause worse air quality. However, when the typhoon system weakens the subtropical high, the prevailing southeasterly surface wind leads to the mitigation of the O3 pollution. The integrated process rate (IPR analysis incorporated in the Community Multi-scale Air Quality (CMAQ model is applied to further illustrate the combined influence of subtropical high and typhoon system in this O3 episode. The results show that the vertical diffusion (VDIF and the gas-phase chemistry (CHEM are two major contributors to O3 formation. During the episode, the contributions of VDIF and CHEM to O3 maintain the high values over the YRD region. On 10–12 August, the cities close to the sea are apparently affected by the typhoon system, with the contribution of VDIF increasing to 28.45 ppb h−1 in Shanghai and 19.76 ppb h−1 in

  6. Identification of fish nursery areas in a free tributary of an impoundment region, upper Uruguay River, Brazil

    Directory of Open Access Journals (Sweden)

    Patrícia Alves da Silva

    2012-01-01

    Full Text Available This study aims to determine the importance of different environments of the Ligeiro River (upper Uruguay River, Brazil in fish reproduction. For this purpose, three environments (sampling sites were selected: rapids, a pool, and the mouth of the Ligeiro River. Ichthyoplankton, zooplankton, and benthos were sampled six times per month from September, 2006 to March, 2007. Zooplankton and ichthyoplankton samples were collected early in the evening with plankton nets (64 µm and 500 µm, respectively. Benthos samples were also collected early in the evening with a Van Veen dredge. Local abiotic variables (temperature, dissolved oxygen, pH, electrical conductivity, water speed, alkalinity, water hardness, and water transparency were measured simultaneously with the biotic data sampling and were complemented by regional variables (water flow and precipitation. A total of 43,475 eggs and 2,269 larvae were captured. Of these larvae, 80.1% were in the pre-flexion and larval yolk stages. Digestive tract content showed that the greatest degree of repletion among the larvae in more advanced phases occurred in the pool environment. Water speed was the main characteristic used to differentiate the river's rapids and mouth from the pool. The abundance of zooplankton and benthos was not related to the distribution of densities among the different components of the ichthyoplankton. A greater abundance of eggs and larvae with yolk was found in the rapids and river mouth. Ordination analyses showed a connection between the advanced stage larvae and the pool environment. In conclusion, the rapids and river mouth of the Ligeiro River's are important locations for fish reproduction, particularly in regard to spawning and drifting of the ichthyoplankton's initial stages, whereas the pool represents a nursery place for larval growth.O presente estudo visa determinar a importância de diferentes ambientes do rio Ligeiro (alto rio Uruguai/Brasil na reprodução dos

  7. Ranching and conservation in the Santa Cruz River Region, Sonora: Milpillas Case Study (Ganaderia y Conservacion en la Region del Rio Santa Cruz, Sonora: El Caso del Grupo Milpillas)

    Science.gov (United States)

    Joaquin Murrieta-Saldivar

    2006-01-01

    The Sonoran Institute (SI) is a non-profit organization working with people toward common conservation goals. Two objectives guide the work of the Sonoran Institute in the Santa Cruz River Region in Sonora, Mexico: to establish projects with community participation that can result in tangible and long-lasting benefits to the environment, and to ensure success by...

  8. Wetland Changes and Their Responses to Climate Change in the “Three-River Headwaters” Region of China since the 1990s

    Directory of Open Access Journals (Sweden)

    Laga Tong

    2014-04-01

    Full Text Available The wetland ecosystem in the “Three-River Headwaters” (TRH region plays an irreplaceable role in water source conservation, run-off adjustment and biodiversity maintenance. In recent years, assessment of wetland resources affected by climate changes has aroused enormous attention, since it can further protect wetland resources and provide a scientific basis for decision makers. In this study, wetland changes and its response to climate changes in the TRH region from the early 1990s to 2012 were analyzed by remote sensing (RS image interpretation and climate change trend analysis. The results showed that wetlands occupied 6.3% of the total land area in 2012, and swamps, streams & rivers and lakes were the dominant wetland types in the TRH region. Since the early 1990s, wetlands have undergone great changes, and total wetland area increased by 260.57 km2 (1.17%. Lakes, reservoir & ponds took on continuous increasing trend, but swamps, streams & rivers had a continuous decreasing trend. On the other hand, the wetland area in the Yangtze River basin showed an overall increasing trend, while in the Yellow River and Langcang River basins, it decreased in general. The climate turned from Warm-Dry to Warm-Wet. The average temperature and precipitation increased by 0.91 °C and 101.99 mm, respectively, from 1990 to 2012, and the average humidity index (HI increased by 0.06 and showing an upward trend and a shifting of the dividing line towards the northwest in both the areas of semi-humid and semi-arid zone. The correlation analysis of wetland changes with meteorological factors from 1990 to 2012 indicated that the regional humidity differences and the interannual variation trend, caused by the change of precipitation and evaporation, was the main driving factor for the dynamic variation of wetland change in the TRH region. In the general, the increase of HI in the THR region since the 1990s, especially in the western TRH region, contributed to

  9. Spermiogenesis in the imbricate alligator lizard, Barisia imbricata (Reptilia, Squamata, Anguidae).

    Science.gov (United States)

    Gribbins, Kevin M; Rheubert, Justin L; Touzinsky, Katherine; Hanover, Jessica; Matchett, Caroline L; Granados-González, Gisela; Hernández-Gallegos, Oswaldo

    2013-06-01

    Although the events of spermiogenesis are commonly studied in amniotes, the amount of research available for Squamata is lacking. Many studies have described the morphological characteristics of mature spermatozoa in squamates, but few detail the ultrastructural changes that occur during spermiogenesis. This study's purpose is to gain a better understanding of the subcellular events of spermatid development within the Imbricate Alligator Lizard, Barisia imbricata. The morphological data presented here represent the first complete ultrastructural study of spermiogenesis within the family Anguidae. Samples of testes from four specimens collected on the northwest side of the Nevado de Toluca, México, were prepared using standard techniques for transmission electron microscopy. Many of the ultrastructural changes occurring during spermiogenesis within B. imbricata are similar to that of other squamates (i.e., early acrosome formation, chromatin condensation, flagella formation, annulus present, and a prominent manchette). However, there are a few unique characteristics within B. imbricata spermatids that to date have not been described during spermiogenesis in other squamates. For example, penetration of the acrosomal granule into the subacrosomal space to form the basal plate of the perforatorium during round spermatid development, the clover-shaped morphology of the developing nuclear fossa of the flagellum, and the bulbous shape to the perforatorium are all unique to the Imbricate Alligator Lizard. These anatomical character differences may be valuable nontraditional data that along with more traditional matrices (such as DNA sequences and gross morphological data) may help elucidate phylogenetic relationships, which are historically considered controversial within Squamata. Copyright © 2013 Wiley Periodicals, Inc.

  10. Mapping Social Vulnerability to Air Pollution: A Case Study of the Yangtze River Delta Region, China

    Directory of Open Access Journals (Sweden)

    Yi Ge

    2017-01-01

    Full Text Available Many frequent and severe air pollution incidents have emerged across the vast parts of China recently. The identification of factors and mapping social vulnerability has become extremely necessary for environmental management and sustainable development. However, studies associating social vulnerability with air pollution remain sparse. With reference to research achievements of social vulnerability, this study made a new trial regarding social vulnerability assessment to air pollution. With the projection pursuit cluster (PPC model, the top three factors contributing to social vulnerability index (SVI were discovered and SVI and SVI dimensions (susceptibility, exposure, and adaptability were evaluated. Results revealed that adaptability values are higher than susceptibility and exposure values. SVI is in a poor condition as, for the whole region, most values belong to the high-medium level. High SVI values mainly appear in the northern and the southern ends of study area. SVI in Shanghai is lower than in Jiangsu and Zhejiang provinces. On the scale of prefecture-level city, it can be found that the low-value centers of SVI always occurred in urban core areas. The spatial variation and inequality in social vulnerability provide policy-makers a scientific basis for air pollution prevention and sustainable management.

  11. Groundwater Discharge of Legacy Nitrogen to River Networks: Linking Regional Groundwater Models to Streambed Groundwater-Surface Water Exchange and Nitrogen Processing

    Science.gov (United States)

    Barclay, J. R.; Helton, A. M.; Briggs, M. A.; Starn, J. J.; Hunt, A.

    2017-12-01

    Despite years of management, excess nitrogen (N) is a pervasive problem in many aquatic ecosystems. More than half of surface water in the United States is derived from groundwater, and widespread N contamination in aquifers from decades of watershed N inputs suggest legacy N discharging from groundwater may contribute to contemporary N pollution problems in surface waters. Legacy N loads to streams and rivers are controlled by both regional scale flow paths and fine-scale processes that drive N transformations, such as groundwater-surface water exchange across steep redox gradients that occur at stream bed interfaces. Adequately incorporating these disparate scales is a challenge, but it is essential to understanding legacy N transport and making informed management decisions. We developed a regional groundwater flow model for the Farmington River, a HUC-8 basin that drains to the Long Island Sound, a coastal estuary that suffers from elevated N loads despite decades of management, to understand broad patterns of regional transport. To evaluate and refine the regional model, we used thermal infrared imagery paired with vertical temperature profiling to estimate groundwater discharge at the streambed interface. We also analyzed discharging groundwater for multiple N species to quantify fine scale patterns of N loading and transformation via denitrification at the streambed interface. Integrating regional and local estimates of groundwater discharge of legacy N to river networks should improve our ability to predict spatiotemporal patterns of legacy N loading to and transformation within surface waters.

  12. Pollution of intensively managed greenhouse soils by nutrients and heavy metals in the Yellow River Irrigation Region, Northwest China.

    Science.gov (United States)

    Kong, Xiaole; Cao, Jing; Tang, Rangyun; Zhang, Shengqiang; Dong, Fang

    2014-11-01

    The present study aimed to assess the potential ecological risk of heavy metals and nutrient accumulation in polytunnel greenhouse soils in the Yellow River irrigation region (YRIR), Northwest China, and to identify the potential sources of these heavy metals using principal component analysis. Contents of available nitrogen (AN), phosphorus (AP), and potassium (AK) in the surface polytunnel greenhouse soils (0-20 cm) varied from 13.42 to 486.78, from 39.10 to 566.97, and from 21.64 to 1,156.40 mg kg(-1), respectively, as well as AP, soil organic matter (SOM) and AK contents tended to increase significantly at the 0-20- and 20-40-cm soil layers. Heavy metal accumulations occurred in the polytunnel greenhouse soils as compared to arable soils, especially at a depth of 20 cm where Cd, Zn and Cu contents were significantly higher than arable soil. Cd and As were found to be the two main polluting elements in the greenhouse soils because their contents exceeded the thresholds established for greenhouse vegetable production HJ333-2006 in China and the background of Gansu province. It has been shown that Cd, Cu, Pb and Zn at the 0-20-cm soil layer were derived mainly from agricultural production activities, whereas contents of Cr and Ni at the same soil layer were determined by 'natural' factors and As originated from natural sources, deposition and irrigation water.

  13. Trends of tropospheric NO2 over the Yangtze River Delta region and the possible linkage to rapid urbanization

    Science.gov (United States)

    Ma, Mingliang; Zhang, Deying; Liu, Qiyang; Song, Yue; Zhou, Jiayuan; Shi, Runhe; Gao, Wei

    2017-09-01

    Over the past decade, China has experienced a rapid increase in urbanization. The urban built-up areas (population) of Shanghai increased by 16.1% (22.9%) from 2006 to 2015. This study aims to analyze the variations of tropospheric NO2 over Yangtze River Delta region and the impacts of rapid urbanization during 2006-2015. The results indicate that tropospheric NO2 vertical column density (VCD) of all cities in the study area showed an increasing trend during 2006-2011 whereas a decreasing trend during 2011-2015. Most cities showed a lower tropospheric NO2 VCD value in 2015 compared to that in 2006, except for Changzhou and Nantong. Shanghai and Ningbo are two hotspots where the tropospheric NO2 VCD decreased most significantly, at a rate of 22% and 19%, respectively. This effect could be ascribed to the implementation of harsh emission control policies therein. Similar seasonal variability was observed over all cities, with larger values observed in the summer and smaller values shown in the winter. Further investigations show that the observed increasing trend of tropospheric NO2 during 2006-2011 could be largely explained by rapid urbanization linked to car ownership, GDP, power consumption, population and total industrial output. Such effect was not prominent after 2011, mainly due to the implementation of emission control strategies.

  14. Study on the Method of Grass Yield Model in the Source Region of Three Rivers with Multivariate Data

    International Nuclear Information System (INIS)

    You, Haoyan; Luo, Chengfeng; Liu, Zhengjun; Wang, Jiao

    2014-01-01

    This paper uses remote sensing and GIS technology to analyse the Source Region of Three Rivers (SRTR) to establish a grass yield estimation model during 2010 with remote sensing data, meteorological data, grassland type data and ground measured data. Analysis of the correlation between ground measured data, vegetation index based HJ-1A/B satellite data, meteorological data and grassland type data were used to establish the grass yield model. The grass yield model was studied by several statistical methods, such as multiple linear regression and Geographically Weighted Regression (GWR). The model's precision was validated. Finally, the best model to estimate the grass yield of Maduo County in SRTR was contrasted with the TM degraded grassland interpretation image of Maduo County from 2009. The result shows that: (1) Comparing with the multiple linear regression model, the GWR model gave a much better fitting result with the quality of fit increasing significantly from less than 0.3 to more than 0.8; (2) The most sensitive factors affecting the grass yield in SRTR were precipitation from May to August and drought index from May to August. From calculation of the five vegetation indices, MSAVI fitted the best; (3) The Maduo County grass yield estimated by the optimal model was consistent with the TM degraded grassland interpretation image, the spatial distribution of grass yield in Maduo County for 2010 showed a ''high south and low north'' pattern

  15. The forecasting research of early warning systems for atmospheric pollutants: A case in Yangtze River Delta region

    Science.gov (United States)

    Song, Yiliao; Qin, Shanshan; Qu, Jiansheng; Liu, Feng

    2015-10-01

    The issue of air quality regarding PM pollution levels in China is a focus of public attention. To address that issue, to date, a series of studies is in progress, including PM monitoring programs, PM source apportionment, and the enactment of new ambient air quality index standards. However, related research concerning computer modeling for PM future trends estimation is rare, despite its significance to forecasting and early warning systems. Thereby, a study regarding deterministic and interval forecasts of PM is performed. In this study, data on hourly and 12 h-averaged air pollutants are applied to forecast PM concentrations within the Yangtze River Delta (YRD) region of China. The characteristics of PM emissions have been primarily examined and analyzed using different distribution functions. To improve the distribution fitting that is crucial for estimating PM levels, an artificial intelligence algorithm is incorporated to select the optimal parameters. Following that step, an ANF model is used to conduct deterministic forecasts of PM. With the identified distributions and deterministic forecasts, different levels of PM intervals are estimated. The results indicate that the lognormal or gamma distributions are highly representative of the recorded PM data with a goodness-of-fit R2 of approximately 0.998. Furthermore, the results of the evaluation metrics (MSE, MAPE and CP, AW) also show high accuracy within the deterministic and interval forecasts of PM, indicating that this method enables the informative and effective quantification of future PM trends.

  16. Research on Nonpoint Source Pollution Assessment Method in Data Sparse Regions: A Case Study of Xichong River Basin, China

    Directory of Open Access Journals (Sweden)

    Xing Liu

    2015-01-01

    Full Text Available The NPS pollution is difficult to manage and control due to its complicated generation and formation mechanism, especially in the data sparse area. Thus the ECM and BTOPMC were, respectively, adopted to develop an easy and practical assessment method, and a comparison between the outputs of them is then conducted in this paper. The literature survey and field data were acquired to confirm the export coefficients of the ECM, and the loads of TN and TP were statistically analyzed in the study area. Based on hydrological similarity, runoff data from nearby gauged sites were pooled to compensate for the lack of at-site data and the water quality submodel of BTOPMC was then applied to simulate the monthly pollutant fluxes in the two sections from 2010 to 2012. The results showed agricultural fertilizer, rural sewage, and livestock and poultry sewage were the main pollution sources, and under the consideration of self-purification capacity of river, the outputs of the two models were almost identical. The proposed method with a main thought of combining and comparing an empirical model and a mechanistic model can assess the water quality conditions in the study area scientifically, which indicated it has a good potential for popularization in other regions.

  17. Clarifying regional hydrologic controls of the Marañón River, Peru through rapid assessment to inform system-wide basin planning approaches

    Directory of Open Access Journals (Sweden)

    Alice F. Hill

    2018-04-01

    Full Text Available We use remote sensing to enhance the interpretation of the first baseline dataset of hydrologic, isotopic and hydrochemical variables spanning 620 km of the upper Marañón River, in Andean Peru, from the steep alpine canyons to the lower lying jungle. Remote, data-scarce river systems are under increased hydropower development pressure to meet rising energy demands. The upstream-downstream river continuum, which serves as a conduit for resource exchange across ecosystems, is at risk, potentially endangering the people, environments, and economies that rely on river resources. The Marañón River, one of the final free-flowing headwater connections between the Andes and the Amazon, is the subject of myriad large-scale hydropower proposals. Due to challenging access, environmental data are scarce in the upper Marañón, limiting our ability to do system-wide river basin planning. We capture key processes and transitions in the context of hydropower development. Two hydrologic regimes control the Marañón dry-season flow: in the higher-elevation upper reaches, a substantial baseflow is fed by groundwater recharged from wet season rains, in contrast to the lower reaches where the mainstem discharge is controlled by rain-fed tributaries that receive rain from lowland Amazon moisture systems. Sustainability of the upper corridor’s dry-season baseflow appears to be more highly connected to the massive natural storage capacity of extensive wetlands in the puna (alpine grasslands than with cryospheric water inputs. The extent and conservation of puna ecosystems and glacier reservoirs may be interdependent, bringing to bear important conservation questions in the context of changing climate and land use in the region. More generally, this case study demonstrates an efficient combined remote sensing and field observation approach to address data scarcity across regional scales in mountain basins facing imminent rapid change.

  18. Allegheny County Major Rivers

    Data.gov (United States)

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

  19. Dissolved radon and uranium in groundwater in a potential coal seam gas development region (Richmond River Catchment, Australia).

    Science.gov (United States)

    Atkins, Marnie L; Santos, Isaac R; Perkins, Anita; Maher, Damien T

    2016-04-01

    The extraction of unconventional gas resources such as shale and coal seam gas (CSG) is rapidly expanding globally and often prevents the opportunity for comprehensive baseline groundwater investigations prior to drilling. Unconventional gas extraction often targets geological layers with high naturally occurring radioactive materials (NORM) and extraction practices may possibly mobilise radionuclides into regional and local drinking water resources. Here, we establish baseline groundwater radon and uranium levels in shallow aquifers overlying a potential CSG target formation in the Richmond River Catchment, Australia. A total of 91 groundwater samples from six different geological units showed highly variable radon activities (0.14-20.33 Bq/L) and uranium levels (0.001-2.77 μg/L) which were well below the Australian Drinking Water Guideline values (radon; 100 Bq/L and uranium; 17 μg/L). Therefore, from a radon and uranium perspective, the regional groundwater does not pose health risks to consumers. Uranium could not explain the distribution of radon in groundwater. Relatively high radon activities (7.88 ± 0.83 Bq/L) in the fractured Lismore Basalt aquifer coincided with very low uranium concentrations (0.04 ± 0.02 μg/L). In the Quaternary Sediments aquifers, a positive correlation between U and HCO3(-) (r(2) = 0.49, p uranium was present as uranyl-carbonate complexes. Since NORM are often enriched in target geological formations containing unconventional gas, establishing radon and uranium concentrations in overlying aquifers comprises an important component of baseline groundwater investigations. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Regional-scale assessment of soil salinity in the Red River Valley using multi-year MODIS EVI and NDVI.

    Science.gov (United States)

    Lobell, D B; Lesch, S M; Corwin, D L; Ulmer, M G; Anderson, K A; Potts, D J; Doolittle, J A; Matos, M R; Baltes, M J

    2010-01-01

    The ability to inventory and map soil salinity at regional scales remains a significant challenge to scientists concerned with the salinization of agricultural soils throughout the world. Previous attempts to use satellite or aerial imagery to assess soil salinity have found limited success in part because of the inability of methods to isolate the effects of soil salinity on vegetative growth from other factors. This study evaluated the use of Moderate Resolution Imaging Spectroradiometer (MODIS) imagery in conjunction with directed soil sampling to assess and map soil salinity at a regional scale (i.e., 10-10(5) km(2)) in a parsimonious manner. Correlations with three soil salinity ground truth datasets differing in scale were made in Kittson County within the Red River Valley (RRV) of North Dakota and Minnesota, an area where soil salinity assessment is a top priority for the Natural Resource Conservation Service (NRCS). Multi-year MODIS imagery was used to mitigate the influence of temporally dynamic factors such as weather, pests, disease, and management influences. The average of the MODIS enhanced vegetation index (EVI) for a 7-yr period exhibited a strong relationship with soil salinity in all three datasets, and outperformed the normalized difference vegetation index (NDVI). One-third to one-half of the spatial variability in soil salinity could be captured by measuring average MODIS EVI and whether the land qualified for the Conservation Reserve Program (a USDA program that sets aside marginally productive land based on conservation principles). The approach has the practical simplicity to allow broad application in areas where limited resources are available for salinity assessment.

  1. Understanding Hydrological Regime Alterations Caused by dams: the Santiago River case in the Andean Region of the Amazon Basin.

    Science.gov (United States)

    Rosero-Lopez, D.; Flecker, A.; Walter, M. T.

    2016-12-01

    Water resources in South America have been clearly targeted as key sources for hydropower expansion over the next 30 years. Ecuador, among the most biologically diverse countries in the world, has the highest density of hydropower dams, either operational, under construction, or planned, in the Amazon Basin. Ecuador's ambitious plan to change its energy portfolio is conceived to satisfy the country's demand and to empower the country to be the region's first hydroelectric energy exporter. The Santiago watershed located in the southeast part of the country has 39 facilities either under construction or in operation. The Santiago River and its main tributaries (Zamora and Upano) are expected to be impounded by large dams over the next 10 years. In order to understand the magnitude and potential impacts of regional dam development on hydrological regimes, a 35-year historical data set of stream discharge was analyzed. We examined flow regimes for time series between the construction of each dam, starting with the oldest and largest built in 1982 up until the most recent dam built in 2005. Preliminary results indicate a systematic displacement in flow seasonality following post-dam compared to pre-dam conditions. There are also notable differences in the distributions of peaks and pulses in post-dam flows. The range of changes from these results shows that punctuated and cumulative impacts are related to the size of each new impoundment. These observations and their implications to the livelihoods, biota, and ecosystems services in the Santiago watershed need to be incorporated into a broader cost-benefit analysis of hydropower generation in the western Amazon Basin.

  2. Nuclear and Related Analytical Techniques Used to Study the Anthropogenic Impact on the Sister River in the Vicinity of the Town of Klin (Moscow Region, Russia)

    CERN Document Server

    Morzhukhina, S V; Chermnykh, L P; Khodakovsky, L P; Frontasyeva, M V; Gundorina, S F

    2001-01-01

    The ecological fate of small rivers, tributaries of the Volga River, is of great concern in the national program of the Russian Federation "Restoration of the Volga River". The results on the elaborated hydrochemical and saprobiological water examination of the Sister River are reported along with the results on the multielement chemical analysis of surface sediments in the catchment of the town of Klin (Moscow Region) known for its numerous industrial and chemical enterprises with heavy contaminant inputs. Epithermal neutron activation analysis was used to study heavy metals and other toxic elements in bottom sediments. A total of 42 elements including Pb, Cu, Cd and Hg were determined by polarography (method of inverse voltamperometry). Metal/Al rations which express the relative mobility of the elements follow the sequence: Fe > Mg > K > Na > Ca >> Zr > Mn > Zn = Sr > Cr > V > Ni = As > Co. Elevated concentrations of Cd, Pb, Zn and Cu in the bottom sediments of the Sister River reinforced us to determine t...

  3. The ophiolitic North Fork terrane in the Salmon River region, central Klamath Mountains, California

    Science.gov (United States)

    Ando, C.J.; Irwin, W.P.; Jones, D.L.; Saleeby, J.B.

    1983-01-01

    The North Fork terrane is an assemblage of ophiolitic and other oceanic volcanic and sedimentary rocks that has been internally imbricated and folded. The ophiolitic rocks form a north-trending belt through the central part of the region and consist of a disrupted sequence of homogeneous gabbro, diabase, massive to pillowed basalt, and interleaved tectonitic harzburgite. U-Pb zircon age data on a plagiogranite pod from the gabbroic unit indicate that at least this part of the igneous sequence is late Paleozoic in age.The ophiolitic belt is flanked on either side by mafic volcanic and volcaniclastic rocks, limestone, bedded chert, and argillite. Most of the chert is Triassic, including much of Late Triassic age, but chert with uncertain stratigraphic relations at one locality is Permian. The strata flanking the east side of the ophiolitic belt face eastward, and depositional contacts between units are for the most part preserved. The strata on the west side of the ophiolitic belt are more highly disrupted than those on the east side, contain chert-argillite melange, and have unproven stratigraphic relation to either the ophiolitic rocks or the eastern strata.Rocks of the North Fork terrane do not show widespread evidence of penetrative deformation at elevated temperatures, except an early tectonitic fabric in the harzburgite. Slip-fiber foliation in serpentinite, phacoidal foliation in chert and mafic rocks, scaly foliation in argillite, and mesoscopic folds in bedded chert are consistent with an interpretation of large-scale anti-formal folding of the terrane about a north-south hinge found along the ophiolitic belt, but other structural interpretations are tenable. The age of folding of North Fork rocks is constrained by the involvement of Triassic and younger cherts and crosscutting Late Jurassic plutons. Deformation in the North Fork terrane must have spanned a short period of time because the terrane is bounded structurally above and below by Middle or Late

  4. Development of a regional groundwater flow model for the area of the Idaho National Engineering Laboratory, Eastern Snake River Plain Aquifer

    International Nuclear Information System (INIS)

    McCarthy, J.M.; Arnett, R.C.; Neupauer, R.M.

    1995-03-01

    This report documents a study conducted to develop a regional groundwater flow model for the Eastern Snake River Plain Aquifer in the area of the Idaho National Engineering Laboratory. The model was developed to support Waste Area Group 10, Operable Unit 10-04 groundwater flow and transport studies. The products of this study are this report and a set of computational tools designed to numerically model the regional groundwater flow in the Eastern Snake River Plain aquifer. The objective of developing the current model was to create a tool for defining the regional groundwater flow at the INEL. The model was developed to (a) support future transport modeling for WAG 10-04 by providing the regional groundwater flow information needed for the WAG 10-04 risk assessment, (b) define the regional groundwater flow setting for modeling groundwater contaminant transport at the scale of the individual WAGs, (c) provide a tool for improving the understanding of the groundwater flow system below the INEL, and (d) consolidate the existing regional groundwater modeling information into one usable model. The current model is appropriate for defining the regional flow setting for flow submodels as well as hypothesis testing to better understand the regional groundwater flow in the area of the INEL. The scale of the submodels must be chosen based on accuracy required for the study

  5. An Assessment of Regional Water Resources and Agricultural Sustainability in the Mississippi River Alluvial Aquifer System of Mississippi and Arkansas Under Current and Future Climate

    Science.gov (United States)

    Rigby, J.; Reba, M.

    2011-12-01

    The Lower Mississippi River Alluvial Plain is a highly productive agricultural region for rice, soy beans, and cotton that depends heavily on irrigation. Development of the Mississippi River Alluvial Aquifer (MRAA), one of the more prolific agricultural aquifers in the country, has traditionally been the primary source for irrigation in the region yielding over 1,100 Mgal/day to irrigation wells. Increasingly, the realities of changing climate and rapidly declining water tables have highlighted the necessity for new water management practices. Tail-water recovery and reuse is a rapidly expanding practice due in part to the efforts and cost-sharing of the NRCS, but regional studies of the potential for such practices to alleviate groundwater mining under current and future climate are lacking. While regional studies of aquifer geology have long been available, including assessments of regional groundwater flow, much about the aquifer is still not well understood including controls on recharge rates, a crucial component of water management design. We review the trends in regional availability of surface and groundwater resources, their current status, and the effects of recent changes in management practices on groundwater decline in Mississippi and Arkansas. Global and regional climate projections are used to assess scenarios of sustainable aquifer use under current land use and management along with the potential for more widely practiced surface water capture and reuse to alleviate groundwater decline. Finally, we highlight crucial knowledge gaps and challenges associated with the development of water management practices for sustainable agricultural use in the region.

  6. Sensitivity of the weather research and forecasting model to parameterization schemes for regional climate of Nile River Basin

    Science.gov (United States)

    Tariku, Tebikachew Betru; Gan, Thian Yew

    2018-06-01

    Regional climate models (RCMs) have been used to simulate rainfall at relatively high spatial and temporal resolutions useful for sustainable water resources planning, design and management. In this study, the sensitivity of the RCM, weather research and forecasting (WRF), in modeling the regional climate of the Nile River Basin (NRB) was investigated using 31 combinations of different physical parameterization schemes which include cumulus (Cu), microphysics (MP), planetary boundary layer (PBL), land-surface model (LSM) and radiation (Ra) schemes. Using the European Centre for Medium-Range Weather Forecast (ECMWF) ERA-Interim reanalysis data as initial and lateral boundary conditions, WRF was configured to model the climate of NRB at a resolution of 36 km with 30 vertical levels. The 1999-2001 simulations using WRF were compared with satellite data combined with ground observation and the NCEP reanalysis data for 2 m surface air temperature (T2), rainfall, short- and longwave downward radiation at the surface (SWRAD, LWRAD). Overall, WRF simulated more accurate T2 and LWRAD (with correlation coefficients >0.8 and low root-mean-square error) than SWRAD and rainfall for the NRB. Further, the simulation of rainfall is more sensitive to PBL, Cu and MP schemes than other schemes of WRF. For example, WRF simulated less biased rainfall with Kain-Fritsch combined with MYJ than with YSU as the PBL scheme. The simulation of T2 is more sensitive to LSM and Ra than to Cu, PBL and MP schemes selected, SWRAD is more sensitive to MP and Ra than to Cu, LSM and PBL schemes, and LWRAD is more sensitive to LSM, Ra and PBL than Cu, and MP schemes. In summary, the following combination of schemes simulated the most representative regional climate of NRB: WSM3 microphysics, KF cumulus, MYJ PBL, RRTM longwave radiation and Dudhia shortwave radiation schemes, and Noah LSM. The above configuration of WRF coupled to the Noah LSM has also been shown to simulate representative regional

  7. Sensitivity of the weather research and forecasting model to parameterization schemes for regional climate of Nile River Basin

    Science.gov (United States)

    Tariku, Tebikachew Betru; Gan, Thian Yew

    2017-08-01

    Regional climate models (RCMs) have been used to simulate rainfall at relatively high spatial and temporal resolutions useful for sustainable water resources planning, design and management. In this study, the sensitivity of the RCM, weather research and forecasting (WRF), in modeling the regional climate of the Nile River Basin (NRB) was investigated using 31 combinations of different physical parameterization schemes which include cumulus (Cu), microphysics (MP), planetary boundary layer (PBL), land-surface model (LSM) and radiation (Ra) schemes. Using the European Centre for Medium-Range Weather Forecast (ECMWF) ERA-Interim reanalysis data as initial and lateral boundary conditions, WRF was configured to model the climate of NRB at a resolution of 36 km with 30 vertical levels. The 1999-2001 simulations using WRF were compared with satellite data combined with ground observation and the NCEP reanalysis data for 2 m surface air temperature (T2), rainfall, short- and longwave downward radiation at the surface (SWRAD, LWRAD). Overall, WRF simulated more accurate T2 and LWRAD (with correlation coefficients >0.8 and low root-mean-square error) than SWRAD and rainfall for the NRB. Further, the simulation of rainfall is more sensitive to PBL, Cu and MP schemes than other schemes of WRF. For example, WRF simulated less biased rainfall with Kain-Fritsch combined with MYJ than with YSU as the PBL scheme. The simulation of T2 is more sensitive to LSM and Ra than to Cu, PBL and MP schemes selected, SWRAD is more sensitive to MP and Ra than to Cu, LSM and PBL schemes, and LWRAD is more sensitive to LSM, Ra and PBL than Cu, and MP schemes. In summary, the following combination of schemes simulated the most representative regional climate of NRB: WSM3 microphysics, KF cumulus, MYJ PBL, RRTM longwave radiation and Dudhia shortwave radiation schemes, and Noah LSM. The above configuration of WRF coupled to the Noah LSM has also been shown to simulate representative regional

  8. A multi-objective framework to predict flows of ungauged rivers within regions of sparse hydrometeorologic observation

    Science.gov (United States)

    Alipour, M.; Kibler, K. M.

    2017-12-01

    Despite advances in flow prediction, managers of ungauged rivers located within broad regions of sparse hydrometeorologic observation still lack prescriptive methods robust to the data challenges of such regions. We propose a multi-objective streamflow prediction framework for regions of minimum observation to select models that balance runoff efficiency with choice of accurate parameter values. We supplement sparse observed data with uncertain or low-resolution information incorporated as `soft' a priori parameter estimates. The performance of the proposed framework is tested against traditional single-objective and constrained single-objective calibrations in two catchments in a remote area of southwestern China. We find that the multi-objective approach performs well with respect to runoff efficiency in both catchments (NSE = 0.74 and 0.72), within the range of efficiencies returned by other models (NSE = 0.67 - 0.78). However, soil moisture capacity estimated by the multi-objective model resonates with a priori estimates (parameter residuals of 61 cm versus 289 and 518 cm for maximum soil moisture capacity in one catchment, and 20 cm versus 246 and 475 cm in the other; parameter residuals of 0.48 versus 0.65 and 0.7 for soil moisture distribution shape factor in one catchment, and 0.91 versus 0.79 and 1.24 in the other). Thus, optimization to a multi-criteria objective function led to very different representations of soil moisture capacity as compared to models selected by single-objective calibration, without compromising runoff efficiency. These different soil moisture representations may translate into considerably different hydrological behaviors. The proposed approach thus offers a preliminary step towards greater process understanding in regions of severe data limitations. For instance, the multi-objective framework may be an adept tool to discern between models of similar efficiency to select models that provide the "right answers for the right reasons

  9. alpha-Crystallin A sequences of Alligator mississippiensis and the lizard Tupinambis teguixin: molecular evolution and reptilian phylogeny.

    Science.gov (United States)

    de Jong, W W; Zweers, A; Versteeg, M; Dessauer, H C; Goodman, M

    1985-11-01

    The amino acid sequences of the eye lens protein alpha-crystallin A from many mammalian and avian species, two frog species, and a dogfish have provided detailed information about the molecular evolution of this protein and allowed some useful inferences about phylogenetic relationships among these species. We now have isolated and sequenced the alpha-crystallins of the American alligator and the common tegu lizard. The reptilian alpha A chains appear to have evolved as slowly as those of other vertebrates, i.e., at two to three amino acid replacements per 100 residues in 100 Myr. The lack of charged replacements and the general types and distribution of replacements also are similar to those in other vertebrate alpha A chains. Maximum-parsimony analyses of the total data set of 67 vertebrate alpha A sequences support the monophyletic origin of alligator, tegu, and birds and favor the grouping of crocodilians and birds as surviving sister groups in the subclass Archosauria.

  10. Effects of mining activities on the release of heavy metals(HMs) in the head water regions of the Heihe River.

    Science.gov (United States)

    Wei, W., Sr.; Ma, R.; Sun, Z.; Bu, J.; Chang, Q.

    2017-12-01

    The head water regions of Heihe River were located in the Qilian orogenic belt, where belongs to the Qilian Mountains National Ecological Nature Protection and has fragile ecosystem. Previous surveys show that the regions were rich in various metal ores, and the mining activities have been intense.The environmental effect of mining activities will be going on several years, while Our field investigation show that there were 23 mines, of which 18 have been historical. This study collected water samples in main Heihe river and its tributaries, groundwaters and soil water, and the sediment samples near the ores. The concentration of HMs in both waters and sediments was measured for characterizing the spatial distribution of HMs, and determining the origin of the HMs in the river waters. Results of water quality assessment show that 67% of water samples failed to reach the Grade II environmental quality standard for surface water in China (GB3838-2002).The spatial distribution of HMs (Cr, Mn, Ni, Cu, Zn, As, Cd, and Pb) is highly correlated with the geographical distribution of local mines, suggesting that various heavy metals(HMs) were released into the Heihe River via mining activities. The Be, Co, Sn, Bi, Th, U were mainly derived from aluminosilicate weathering crusts. And the acid mine wastewater was the main source for Cu, Zn, Pb, Cd. The Serpentine wreathing was the main source for Cr and Ni. Mn and Cs were enriched by agricultural activities.

  11. Regional scale flood modeling using NEXRAD rainfall, GIS, and HEC-HMS/RAS: a case study for the San Antonio River Basin Summer 2002 storm event.

    Science.gov (United States)

    Knebl, M R; Yang, Z-L; Hutchison, K; Maidment, D R

    2005-06-01

    This paper develops a framework for regional scale flood modeling that integrates NEXRAD Level III rainfall, GIS, and a hydrological model (HEC-HMS/RAS). The San Antonio River Basin (about 4000 square miles, 10,000 km2) in Central Texas, USA, is the domain of the study because it is a region subject to frequent occurrences of severe flash flooding. A major flood in the summer of 2002 is chosen as a case to examine the modeling framework. The model consists of a rainfall-runoff model (HEC-HMS) that converts precipitation excess to overland flow and channel runoff, as well as a hydraulic model (HEC-RAS) that models unsteady state flow through the river channel network based on the HEC-HMS-derived hydrographs. HEC-HMS is run on a 4 x 4 km grid in the domain, a resolution consistent with the resolution of NEXRAD rainfall taken from the local river authority. Watershed parameters are calibrated manually to produce a good simulation of discharge at 12 subbasins. With the calibrated discharge, HEC-RAS is capable of producing floodplain polygons that are comparable to the satellite imagery. The modeling framework presented in this study incorporates a portion of the recently developed GIS tool named Map to Map that has been created on a local scale and extends it to a regional scale. The results of this research will benefit future modeling efforts by providing a tool for hydrological forecasts of flooding on a regional scale. While designed for the San Antonio River Basin, this regional scale model may be used as a prototype for model applications in other areas of the country.

  12. [Study on distribution characteristics and potential ecological risk of so