Sample records for victoria drainage basin

  1. within the lake victoria basin, tanzania

    African Journals Online (AJOL)

    ABSTRACT. Levels of nitrates (NOg-N) and phosphates (PO4~P) in some satellite lakes within the Lake. Victoria basin were determined in Kagera (Lake Burigt), in Mara (River Mara) and in Mwanza region (Lake Malimbe) during August/September 2002 (dry season) and January/February 2003. (wet season).

  2. Drainage basin delineations for selected USGS streamflow-gaging stations in Virginia (Drainage_Basin) (United States)

    U.S. Geological Survey, Department of the Interior — The Drainage_Basin polygon feature class was created as a digital representation of drainage basins for more than 1,650 continuous-record streamflow-gaging stations,...


    African Journals Online (AJOL)

    Water, sediment and soil samples collected from Southern Lake Victoria and its basin were analysed for 76 organochlorine, organophosphorous, carbamate and pyrethroid pesticide residues. The samples were collected from sampling stations in nine districts on the Tanzanian side of the lake, namely Mwanza, Sengerema ...

  4. Assessment of spatial rainfall variability in Lake Victoria Basin (United States)

    Kizza, M.; Westerberg, I.; Rodhe, A.; Ntale, H. K.


    A gridded monthly rainfall dataset having a spatial resolution of 2 km and covering the period 1960-2004 was derived for the Lake Victoria basin. Such a dataset is useful for hydrological modelling aimed at resource utilisation and for estimation of catchment inflow to Lake Victoria. The lake and its basin support more than 30 million people and also contribute substantially to the River Nile flow. The major challenge in analysing the lake water balance is the estimation of the rainfall over the lake which is complicated by the varying quality and spatial coverage of rain-gauge data in the basin. In this study we addressed these problems by using satellite-derived precipitation data from two products and rain-gauge data for 362 stations around the basin to derive a monthly precipitation dataset for the entire basin, including the lake. First, the rain-gauge data were quality controlled; resulting in a rejection of 13% of the stations while 12% needed corrective actions. These results emphasise the importance of a systematic quality control of rain-guage data in this region. Thereafter we filled short gaps in the daily data series which resulted in 9,429 additional months of data. Two interpolation methods were then assessed for spatial interpolation and the universal kriging method performed slightly better than the inverse distance weighting method. The rainfall patterns in the interpolated dataset were shown to be consistent with the spatial and temporal patterns expected at the large scale as a result of the climate variability in the basin. The key problem of how to account for the enhancement of rainfall over the lake surface because of the lake-land thermal contrasts was addressed by estimating a relationship between rain-gauge and satellite data. Two satellite rainfall products, TRMM 3B43 and PERSIANN were compared to the interpolated monthly rain-gauge data for the land part of the basin. The bias in the TRMM 3B43 rainfall estimates was higher than the bias


    Directory of Open Access Journals (Sweden)

    I. C. Stanga


    Full Text Available This article covers a monographic presentation of the soils from the Tutova drainage basin. The analysis of the pedogeographic assemblage was performed based on the soil surveys of the territories corresponding to Tutova’s drainage basin, and completed with field research. The taxonomic classification was done in accordance with the Romanian System of Soil Taxonomy (2003 and the soil map was created at a 1:25.000 scale. The zonal soils dominate the region; the Chernisols are on the first rank with a share of 39.95%, followed by Luvisols with a percent of 27.62%. Among the soils with an azonal and intrazonal character, the entic soils are dominant (21.90%, followed by Anthrosols (8.89% and by Hydrisols (1.64%.

  6. Lunnyu soils in the Lake Victoria basin of Uganda: Link to ...

    African Journals Online (AJOL)

    Lunnyu soils in the Lake Victoria basin of Uganda: Link to toposequence and soil type. B Fungo, S Grunwald, MM Tenywa, B Vanlauwe, P Nkedi-Kizza. Abstract. We compared the physico-chemical characteristics of Lunnyu soils using soil type and slope position in order to explain their variability in the Lake Victoria basin ...

  7. Thermokarst lakes, drainage, and drained basins (United States)

    Grosse, G.; Jones, B.; Arp, C.; Shroder, John F.


    Thermokarst lakes and drained lake basins are widespread in Arctic and sub-Arctic permafrost lowlands with ice-rich sediments. Thermokarst lake formation is a dominant mode of permafrost degradation and is linked to surface disturbance, subsequent melting of ground ice, surface subsidence, water impoundment, and positive feedbacks between lake growth and permafrost thaw, whereas lake drainage generally results in local permafrost aggradation. Thermokarst lakes characteristically have unique limnological, morphological, and biogeochemical characteristics that are closely tied to cold-climate conditions and permafrost properties. Thermokarst lakes also have a tendency toward complete or partial drainage through permafrost degradation and erosion. Thermokarst lake dynamics strongly affect the development of landscape geomorphology, hydrology, and the habitat characteristic of permafrost lowlands.

  8. Editorial The “Eye” of Africa: A Vision of Lake Victoria Basin as an ...

    African Journals Online (AJOL)


    The “Eye” of Africa: A Vision of Lake Victoria Basin as an Environmental. Observatory. Since my days as a schoolboy in geography class, I have not been able to observe maps of the African continent without also “seeing” the profile of a face, with Lake Victoria representing the right eye, gazing adoringly at Madagascar.

  9. Extent and drainage status of organic soils in the Lake Victoria catchment (United States)

    Barthelmes, Reni; Barthelmes, Alexandra; Joosten, Hans


    When considering peatlands and organic soils in the tropics, the huge areas in SE Asia prevail in public and scientific perception, whereas Africa has largely been out of focus. However, East Africa contains large areas of organic soils as well. They basically occur in the high altitudes of the uplifted flanks of the East African Rift System, isolated volcanoes and the Ethiopian highlands, in the Zambezian floodplains (e.g. Zambia), and in coastal environments (e.g. Mozambique and Madagascar). We used a mapping approach that integrates old field data and maps, specialized landscape and peatland-related knowledge, and modern RS and GIS techniques to elaborate a comprehensive and rather reliable overview of organic soils (incl. peatlands) in the Lake Victoria catchment. Maps at a scale of 1:25,000 have been prepared for Burundi, Kenya, Rwanda, Tanzania and Uganda. The land use intensity has been estimated for all organic soil areas based on satellite and aerial imagery. Feeding the Nile River, sustaining a fast growing and widely poor population and already facing climatic changes, organic soils of the Lake Victoria neighbouring countries are partially under heavy threat. We mapped 10,645 km2 of organic soils for the entire area of which 8,860 km2 (83.2%) seem to be in near natural condition. We assume slightly drainage and low degradation for 564 km2 (5.3%) and intensive drainage and heavy degradation for 1,222 km2 (11.5%). Degradation hotspot is Burundi with 522 km2 (79.5%) of heavily drained and degrading organic soils. This area assessment has been quite conservative to not overestimate the extent of organic soils. A reserve of 5-7,000 km2 of wetlands in the Lake Victoria catchment may include peatlands too, which needs to be confirmed in field surveys. Considering the key role of peatlands and organic soils for water provision and regulation and their rapid degradation due to drainage and inappropriate use, this inventory might be a step towards organic soil

  10. Performance assessment of groundwater drainage basin in small-sized mountain rivers based on DTM (United States)

    Nikitenkov, A.; Dutova, E.; Pokrovsky, D.


    The paper describes the performance assessment methods for groundwater drainage basin based on the analysis of morphometric indices of small-sized mountain river drainage basins. DTM was applied to analyze morphometric indices of drainage basins.

  11. Irrigation drainage: Green River basin, Utah (United States)

    Stephens, Doyle W.; Waddell, Bruce; Miller, Jerry B.


    A reconnaissance of wildlife areas in the middle Green River basin of Utah during 1986-87 determined that concentrations of selenium in water and biological tissues were potentially harmful to wildlife at the Stewart Lake Waterfowl Management Area and in the Ouray National Wildlife Refuge. Concentations of selenium in irrigation drainage entering Stewart Lake ranged from 14 to 140 micrograms per liter; liver tissue from coots collected from the lake contained selenium concentrations of as much as 26 micrograms per gram and samples of tissue from carp contained as much as 31 micrograms per gram. Concentrations of selenium in a pond at the Ouray National Wildlife Refuge, which receives irrigation water and shallow ground water, were as much as 93 micrograms per liter. Liver tissue from coots collected from this pond contained selenium concentrations of as much as 43 micrograms per gram; eggs of water birds contained as much as 120 micrograms per gram.

  12. Drainage characteristics of Hirehalla basin, Shimoga district, Karnataka. (United States)

    Patel, M E; Prabhakar, B C; Lokesh, K N


    In order to understand the dynamics of Hirehalla watershed, an attempt has been made to study drainage characteristics. The linear, areal and relief aspects of the basin have been analysed and compared with other climatic factors.

  13. Drainage divides, Massachusetts; Blackstone and Thames River basins (United States)

    Krejmas, Bruce E.; Wandle, S. William


    Drainage boundaries for selected subbasins of the Blackstone and Thames River basins in eastern Hampden, eastern Hampshire, western Norfolk, southern Middlesex, and southern Worcester Counties, Massachusetts, are delineated on 12 topographic quadrangle maps at a scale of 1:24,000. Drainage basins are shown for all U.S. Geological Survey data-collection sites and for mouths of major rivers. Drainage basins are shown for the outlets of lakes or ponds and for streams where the drainage area is greater than 3 square miles. Successive sites along watercourses are indicated where the intervening area is at least 6 miles on tributary streams or 15 square miles along the Blackstone River, French River, or Quinebaug River. (USGS)

  14. satellite lakes of lake victoria basin (tanzanian side)

    African Journals Online (AJOL)

    Studies on phytoplankton species diversity and abundance were carried out in 8 selected satellite lakes within the Lake Victoria ... cyanobacteria occurrence and their unforeseen effects such as toxin production and oxygen depletion during nights that may ..... Species extinction and concomitant ecological changes in Lake.

  15. Use of land located within Eselnita drainage basin

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    Full Text Available Developed on the south-eastern side of Almãjului Mountains, Eşelniţa drainage basin neighbours upon the following basins: upon S – SV with Mala, upon SV - V with Mraconia, upon V - NV with Berzasca, upon NV - NNE with Nera and on the NNE – SE direction with Cerna. The basin has a surface of 77 km2 and present a 5th degree hydrographic network according to Horton-Strahler ranking system, tributary to Danube by means of Eşelniţa main collector. Among surfaces belonging to various categories of use of land located within Eselnita drainage basin, there may be noticed the high share of forest and secondary grazing lands, although the latter have a smaller surface in comparison to the first ones. Therefore, the types of use of land located within the drainage basin are distinguished by the high share of surfaces of forests to the detriment of predominant agricultural land proven by using of some quantitative indexes defining the character of the Eselnita drainage basin as belonging to forestry type. Also the impact of human activities and number of inhabitants do not have a very damaging influence on the land corresponding to the basin, therefore it has a naturality index indicating an ecological equilibrium closed to the natural one.

  16. affect rice in integrated rice-fish culture in Lake Victoria Basin, Kenya?

    African Journals Online (AJOL)


    To ensure increased adoption of rice-fish farming, we have to be certain that practices and adoption of these technologies fit within the available resources, the socio-cultural and economic conditions of the Lake. Victoria Basin (LVB). Practices and technologies from. Asia may be inappropriate due to differences in agro cli-.

  17. The heat budget of the Ross drainage basin

    NARCIS (Netherlands)

    Oerlemans, J.


    Integration of the thermodynamic equation over an entire drainage basin yields a fairly simple expression for the steady-state heat balance. This stems from the fact that dissipative heating can be calculated directly from the release of gravitational energy. When mass balance, surface

  18. Implication of drainage basin parameters of a tropical river basin of South India (United States)

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


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

  19. Streamflow distribution maps for the Cannon River drainage basin, southeast Minnesota, and the St. Louis River drainage basin, northeast Minnesota (United States)

    Smith, Erik A.; Sanocki, Chris A.; Lorenz, David L.; Jacobsen, Katrin E.


    Streamflow distribution maps for the Cannon River and St. Louis River drainage basins were developed by the U.S. Geological Survey, in cooperation with the Legislative-Citizen Commission on Minnesota Resources, to illustrate relative and cumulative streamflow distributions. The Cannon River was selected to provide baseline data to assess the effects of potential surficial sand mining, and the St. Louis River was selected to determine the effects of ongoing Mesabi Iron Range mining. Each drainage basin (Cannon, St. Louis) was subdivided into nested drainage basins: the Cannon River was subdivided into 152 nested drainage basins, and the St. Louis River was subdivided into 353 nested drainage basins. For each smaller drainage basin, the estimated volumes of groundwater discharge (as base flow) and surface runoff flowing into all surface-water features were displayed under the following conditions: (1) extreme low-flow conditions, comparable to an exceedance-probability quantile of 0.95; (2) low-flow conditions, comparable to an exceedance-probability quantile of 0.90; (3) a median condition, comparable to an exceedance-probability quantile of 0.50; and (4) a high-flow condition, comparable to an exceedance-probability quantile of 0.02.Streamflow distribution maps were developed using flow-duration curve exceedance-probability quantiles in conjunction with Soil-Water-Balance model outputs; both the flow-duration curve and Soil-Water-Balance models were built upon previously published U.S. Geological Survey reports. The selected streamflow distribution maps provide a proactive water management tool for State cooperators by illustrating flow rates during a range of hydraulic conditions. Furthermore, after the nested drainage basins are highlighted in terms of surface-water flows, the streamflows can be evaluated in the context of meeting specific ecological flows under different flow regimes and potentially assist with decisions regarding groundwater and surface

  20. Open Drainage and Detention Basin Combined System Optimization

    Directory of Open Access Journals (Sweden)

    M. E. Banihabib


    Full Text Available Introduction: Since flooding causes death and economic damages, then it is important and is one of the most complex and destructive natural disaster that endangers human lives and properties compared to any other natural disasters. This natural disaster almost hit most of countries and each country depending on its policy deals with it differently. Uneven intensity and temporal distribution of rainfall in various parts of Iran (which has arid and semiarid climate causes flash floods and leads to too much economic damages. Detention basins can be used as one of the measures of flood control and it detains, delays and postpones the flood flow. It controls floods and affects the flood directly and rapidly by temporarily storing of water. If the land topography allows the possibility of making detention basin with an appropriate volume and quarries are near to the projects for construction of detention dam, it can be used, because of its faster effect comparing to the other watershed management measures. The open drains can be used alone or in combination with detention basin instead of detention basin solitarily. Since in the combined system of open and detention basin the dam height is increasing in contrast with increasing the open drainage capacity, optimization of the system is essential. Hence, the investigation of the sensitivity of optimized combined system (open drainage and detention basin to the effective factors is also useful in appropriately design of the combined system. Materials and Methods: This research aims to develop optimization model for a combined system of open drainage and detention basins in a mountainous area and analyze the sensitivity of optimized dimensions to the hydrological factors. To select the dam sites for detention basins, watershed map with scale of 1: 25000 is used. In AutoCAD environment, the location of the dam sites are assessed to find the proper site which contains enough storage volume of the detention

  1. Erosion in the juniata river drainage basin, Pennsylvania (United States)

    Sevon, W.D.


    Previously calculated erosion rates througouth the Appalachians range from 1.2 to 203 m Myr-1. Calculation of erosion rates has been accomplished by: (1) evaluation of riverine solute and sediment load in either large or small drainage basins; (2) estimation from the volume of derived sediments; and (3) methods involving either 10Be or fission-track dating. Values of specific conductance and suspended sediment collected at the Juniata River gauging station at Newport, Pennsylvania are used, with corrections, along with a bedload estimate to determine the total amount eroded from the 8687 km2 drainage basin during the water years 1965-1986. The amount eroded is used to calculate a present erosion rate of 27 m Myr-1. ?? 1989.

  2. Preliminary assessment of the cocial, economic and environmental impacts of Water Hyacinth in Lake Victoria basin and status of control


    Mailu, A.M.


    The paper presents preliminary data collected in an assessment of the social, economic and environmental impacts of water hyacinth in the Lake Victoria Basin. A summary of the status of control and strategies for the future is given. The report draws on field observations made, studies through interviews of affected communities and organisations, personal communications and published reports by scientists in the region. Lake Victoria, the world’s second largest freshwater body, su...

  3. Critical Concavity of a Drainage Basin for Steady-State (United States)

    Byun, Jongmin; Paik, Kyungrock


    Longitudinal profiles of natural streams are known to show concave forms. Saying A as drainage area, channel gradient S can be expressed as the power-law, S≈A-θ (Flint, 1974), which is one of the scale-invariant features of drainage basin. According to literature, θ of most natural streams falls into a narrow range (0.4 natural drainage basins?' To answer above questions, we analytically derive θ for a steady-state drainage basin following Lane's equilibrium (Lane, 1955) throughout the corridor and named this specific case as the 'critical concavity'. In the derivation, sediment transport capacity is estimated by unit stream power model (Yang, 1976), yielding a power function of upstream area. Stability of channel at a local point occurs when incoming flux equals outgoing flux at the point. Therefore, given the drainage at steady-state where all channel beds are stable, the exponent of the power function should be zero. From this, we can determine the critical concavity. Considering ranges of variables associated in this derivation, critical concavity cannot be resolved as a single definite value, rather a range of critical concavity is suggested. This range well agrees with the widely reported range of θ (0.4 natural streams. In this theoretical study, inter-relationships between power-laws such as hydraulic geometry (Leopold and Maddock, 1953), dominant discharge-drainage area (Knighton et al., 1999), and concavity, are coupled into the power-law framework of stream power sediment transport model. This allows us to explore close relationships between their power-law exponents: their relative roles and sensitivity. Detailed analysis and implications will be presented. References Flint, J. J., 1974, Stream gradient as a function of order, magnitude, and discharge, Water Resources Research, 10, 969-973. Knighton, A. D., 1999, Downstream variation in stream power, Geomorphology, 29, 293-306. Lane, E. W., 1955, The importance of fluvial morphology in hydraulic

  4. Schistosoma kisumuensis n. sp. (Digenea: Schistosomatidae) from murid rodents in the Lake Victoria Basin, Kenya and its phylogenetic position within the S. haematobium species group. (United States)

    Hanelt, B; Brant, S V; Steinauer, M L; Maina, G M; Kinuthia, J M; Agola, L E; Mwangi, I N; Mungai, B N; Mutuku, M W; Mkoji, G M; Loker, E S


    Schistosoma kisumuensis n. sp. is described based on 6 adult males and 2 adult females collected from the circulatory system of 3 murid rodent species, Pelomys isseli, Mastomys natalensis, and Dasymys incomtus. Specimens were collected from a single location, Nyabera Swamp, in Kisumu, Kenya in the Lake Victoria Basin. This new species is morphologically similar to members of the S. haematobium group, currently represented by 8 species parasitizing artiodactyls and primates, including humans. Schistosoma kisumuensis differs from these species by producing relatively small Schistosoma intercalatum-like eggs (135.2 x 52.9 microm) with a relatively small length to width ratio (2.55). Comparison of approximately 3000-base-pair sequences of nuclear rDNA (partial 28S) and mtDNA (partial cox1, nad6, 12S) strongly supports the status of S. kisumuensis as a new species and as a sister species of S. intercalatum. The cox1 genetic distance between these two species (6.3%) is comparable to other pairwise comparisons within the S. haematobium group. Separation of the Congo River and Lake Victoria drainage basins is discussed as a possible factor favoring the origin of this species.

  5. LBA-ECO CD-06 Amazon River Basin Land and Stream Drainage Direction Maps (United States)

    National Aeronautics and Space Administration — This data set provides high-resolution (~500 m) gridded land and stream drainage direction maps for the Amazon River basin, excluding the Rio Tocantins basin. These...

  6. Hydrogeomorphic effects of explosive volcanic eruptions on drainage basins (United States)

    Pierson, Thomas C.; Major, Jon J.


    Explosive eruptions can severely disturb landscapes downwind or downstream of volcanoes by damaging vegetation and depositing large volumes of erodible fragmental material. As a result, fluxes of water and sediment in affected drainage basins can increase dramatically. System-disturbing processes associated with explosive eruptions include tephra fall, pyroclastic density currents, debris avalanches, and lahars—processes that have greater impacts on water and sediment discharges than lava-flow emplacement. Geo-morphic responses to such disturbances can extend far downstream, persist for decades, and be hazardous. The severity of disturbances to a drainage basin is a function of the specific volcanic process acting, as well as distance from the volcano and magnitude of the eruption. Postdisturbance unit-area sediment yields are among the world's highest; such yields commonly result in abundant redeposition of sand and gravel in distal river reaches, which causes severe channel aggradation and instability. Response to volcanic disturbance can result in socioeconomic consequences more damaging than the direct impacts of the eruption itself.

  7. Geochemistry of the Birch Creek Drainage Basin, Idaho (United States)

    Swanson, Shawn A.; Rosentreter, Jeffrey J.; Bartholomay, Roy C.; Knobel, LeRoy L.


    The U.S. Survey and Idaho State University, in cooperation with the U.S. Department of Energy, are conducting studies to describe the chemical character of ground water that moves as underflow from drainage basins into the eastern Snake River Plain aquifer (ESRPA) system at and near the Idaho National Engineering and Environmental Laboratory (INEEL) and the effects of these recharge waters on the geochemistry of the ESRPA system. Each of these recharge waters has a hydrochemical character related to geochemical processes, especially water-rock interactions, that occur during migration to the ESRPA. Results of these studies will benefit ongoing and planned geochemical modeling of the ESRPA at the INEEL by providing model input on the hydrochemical character of water from each drainage basin. During 2000, water samples were collected from five wells and one surface-water site in the Birch Creek drainage basin and analyzed for selected inorganic constituents, nutrients, dissolved organic carbon, tritium, measurements of gross alpha and beta radioactivity, and stable isotopes. Four duplicate samples also were collected for quality assurance. Results, which include analyses of samples previously collected from four other sites, in the basin, show that most water from the Birch Creek drainage basin has a calcium-magnesium bicarbonate character. The Birch Creek Valley can be divided roughly into three hydrologic areas. In the northern part, ground water is forced to the surface by a basalt barrier and the sampling sites were either surface water or shallow wells. Water chemistry in this area was characterized by simple evaporation models, simple calcite-carbon dioxide models, or complex models involving carbonate and silicate minerals. The central part of the valley is filled by sedimentary material and the sampling sites were wells that are deeper than those in the northern part. Water chemistry in this area was characterized by simple calcite-dolomite-carbon dioxide

  8. Characteristics of potential gasifier fuels in selected regions of the Lake Victoria Basin

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    Geoffrey O. Mosiori


    Full Text Available All countries in the Lake Victoria Basin depend mostly on hydroelectric power for the provision of energy. Gasification technology has a high potential for reducing biomass energy consumption whilst increasing access to modern energy services. The key aspect for the failure of gasification operations in the Lake Victoria Basin is inadequate adaptation of gasification equipment to fuel characteristics, lack of fuel specification and inappropriate material choice. We therefore investigated the thermo-chemical characterisation of six biomass fuels, namely Pinus caribaea, Calitris robusta, Cupressus lusitanica, Eucalyptus grandis, Pinus patula and sugarcane bagasse from selected regions of the Lake Victoria Basin. Ultimate analysis was done using a Flash 2000 elemental analyser. Moisture content, ash content and volatile matter were determined in oven and muffle furnaces while heating values were determined using a Gallenkamp calorimeter. The mean percentage levels obtained indicate that all six biomass fuels had a mean range for nitrogen of 0.07±0.2–0.25±0.07%, for carbon of 40.45±0.61–48.88±0.29%, for hydrogen of 4.32±0.13–5.59±0.18% and for oxygen of 43.41±1.58–51.1±0.64%. Moisture content ranged between 25.74±1.54% and 56.69±0.52%, ash content between 0.38±0.02% and 2.94±0.14%, volatile matter between 74.68±0.49% and 82.71±0.19% and fixed carbon between 14.35±0.33% and 24.74±0.27%. Heating values ranged between 16.95±0.10 MJ/kg and 19.48±0.42 MJ/kg. The results suggest that all six biomass fuels are potential biomass gasification materials.

  9. Tsetse fly (G. f. fuscipes distribution in the Lake Victoria basin of Uganda.

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    Mugenyi Albert


    Full Text Available Tsetse flies transmit trypanosomes, the causative agent of human and animal African trypanosomiasis. The tsetse vector is extensively distributed across sub-Saharan Africa. Trypanosomiasis maintenance is determined by the interrelationship of three elements: vertebrate host, parasite and the vector responsible for transmission. Mapping the distribution and abundance of tsetse flies assists in predicting trypanosomiasis distributions and developing rational strategies for disease and vector control. Given scarce resources to carry out regular full scale field tsetse surveys to up-date existing tsetse maps, there is a need to devise inexpensive means for regularly obtaining dependable area-wide tsetse data to guide control activities. In this study we used spatial epidemiological modelling techniques (logistic regression involving 5000 field-based tsetse-data (G. f. fuscipes points over an area of 40,000 km2, with satellite-derived environmental surrogates composed of precipitation, temperature, land cover, normalised difference vegetation index (NDVI and elevation at the sub-national level. We used these extensive tsetse data to analyse the relationships between presence of tsetse (G. f. fuscipes and environmental variables. The strength of the results was enhanced through the application of a spatial autologistic regression model (SARM. Using the SARM we showed that the probability of tsetse presence increased with proportion of forest cover and riverine vegetation. The key outputs are a predictive tsetse distribution map for the Lake Victoria basin of Uganda and an improved understanding of the association between tsetse presence and environmental variables. The predicted spatial distribution of tsetse in the Lake Victoria basin of Uganda will provide significant new information to assist with the spatial targeting of tsetse and trypanosomiasis control.

  10. Tsetse fly (G. f. fuscipes) distribution in the Lake Victoria basin of Uganda. (United States)

    Albert, Mugenyi; Wardrop, Nicola A; Atkinson, Peter M; Torr, Steve J; Welburn, Susan C


    Tsetse flies transmit trypanosomes, the causative agent of human and animal African trypanosomiasis. The tsetse vector is extensively distributed across sub-Saharan Africa. Trypanosomiasis maintenance is determined by the interrelationship of three elements: vertebrate host, parasite and the vector responsible for transmission. Mapping the distribution and abundance of tsetse flies assists in predicting trypanosomiasis distributions and developing rational strategies for disease and vector control. Given scarce resources to carry out regular full scale field tsetse surveys to up-date existing tsetse maps, there is a need to devise inexpensive means for regularly obtaining dependable area-wide tsetse data to guide control activities. In this study we used spatial epidemiological modelling techniques (logistic regression) involving 5000 field-based tsetse-data (G. f. fuscipes) points over an area of 40,000 km2, with satellite-derived environmental surrogates composed of precipitation, temperature, land cover, normalised difference vegetation index (NDVI) and elevation at the sub-national level. We used these extensive tsetse data to analyse the relationships between presence of tsetse (G. f. fuscipes) and environmental variables. The strength of the results was enhanced through the application of a spatial autologistic regression model (SARM). Using the SARM we showed that the probability of tsetse presence increased with proportion of forest cover and riverine vegetation. The key outputs are a predictive tsetse distribution map for the Lake Victoria basin of Uganda and an improved understanding of the association between tsetse presence and environmental variables. The predicted spatial distribution of tsetse in the Lake Victoria basin of Uganda will provide significant new information to assist with the spatial targeting of tsetse and trypanosomiasis control.

  11. SUGAR CANE GROWING AND CATTLE GRAZING AS DRIVERS TO WETLAND DEGRADATION IN UGANDA: A case of upper river Ruizi and Iguluibi catchments Lake Victoria basin (United States)

    Nakiyemba Were, Alice; Isabirye, Moses; Mathijs, Erik; Deckers, Jozef; Poesen, Jean


    land loosing fertility upland, due to erosion and runoff, most community members have resorted to wetlands for agricultural practices with in the catchment and this has hardly left any natural vegetation to protect the soil and increased runoff to Lake Victoria hence sediment pollution of the lake waters. In the Ruizi catchment, many valleys, the natural vegetation has been cut and the land has been turned into pastureland. The massive expansion of livestock keeping into the low lands mainly covered by wetlands is relatively new (over the last 20 years). Burning of rangelands is a common practice and seasonal swamps are grazed during the dry season This change of land use as far as farming practice is concerned has had a big impact on the water levels of the River Ruizi systems in a number of ways for example: the wetland filter system for sediments and sediment fixed nutrients is compromised; lowering of the water storage capacity of the papyrus swamps as a consequence of drainage, hence surface lowering; river bank erosion of the Ruizi by livestock coming into the river for drinking; pollution of the River Ruizi by livestock defecating into the water while drinking. Due to overstocking of the steep slopes by livestock, the low lands are overgrazed which has resulted in soil erosion, that is, mainly sheet and rill erosion, mass movement below cattle tracks, and stone movement by cattle trampling. The steep slope grazing area has generated substantial runoff, the concentrated flow of which causes gullies that cut through the banana groves. Conclusion Vegetation management of riparian areas especially wetlands in Uganda should conserve and maintain adequate ecological balance of the Lake by reducing on nutrient-loaded fluxes from the riparian zone into the Lake Victoria basin.

  12. Climatic, socio-economic, and health factors affecting human vulnerability to cholera in the Lake Victoria basin, East Africa. (United States)

    Olago, Daniel; Marshall, Michael; Wandiga, Shem O; Opondo, Maggie; Yanda, Pius Z; Kanalawe, Richard; Githeko, Andrew K; Downs, Tim; Opere, Alfred; Kavumvuli, Robert; Kirumira, Edward; Ogallo, Laban; Mugambi, Paul; Apindi, Eugene; Githui, Faith; Kathuri, James; Olaka, Lydia; Sigalla, Rehema; Nanyunja, Robinah; Baguma, Timothy; Achola, Pius


    Cholera epidemics have a recorded history in the eastern Africa region dating to 1836. Cholera is now endemic in the Lake Victoria basin, a region with one of the poorest and fastest growing populations in the world. Analyses of precipitation, temperatures, and hydrological characteristics of selected stations in the Lake Victoria basin show that cholera epidemics are closely associated with El Niño years. Similarly, sustained temperatures high above normal (T(max)) in two consecutive seasons, followed by a slight cooling in the second season, trigger an outbreak of a cholera epidemic. The health and socioeconomic systems that the lake basin communities rely upon are not robust enough to cope with cholera outbreaks, thus rendering them vulnerable to the impact of climate variability and change. Collectively, this report argues that communities living around the Lake Victoria basin are vulnerable to climate-induced cholera that is aggravated by the low socioeconomic status and lack of an adequate health care system. In assessing the communities' adaptive capacity, the report concludes that persistent levels of poverty have made these communities vulnerable to cholera epidemics.

  13. Rock Glaciers in the Upper Basin of Bermejo River, Santa Victoria, Argentina (United States)

    Ahumada, A. L.; Íbáñez Palacios, G. P.; Toledo, M. A.; Páez, S. V.


    The Bermejo River is an international basin in the Tropical Andes, Santa Victoria range. The Santa Victoria range extend in N-S sense (22°08' and 23°00' South latitude between 65° and 65°30' West longitude). It maxim height is about 5.055 m s.n.m. and it average height is 3000 m s.n.m. There have been localize intact rock glaciers (active and inactive) and relict. The rock glaciers are frozen water reservoir and regulate the water regime in the high mountain over the world. The global warming effects have been express in this region with average annual air temperatures in increase: The series of temperatures of La Quiaca weather station, years 1911-2010, shows an increase about 1° C (from 9,14° C to 10,08° C) since 70' decade to actuality. This study aims to contribute to the survey of intact rock glaciers and the suite of accompanying landforms. The geographic identification and location of rock glaciers have made through the interpretation of aerial photographs and LandSat 7 and Aster Images in comparison with Google Earth using GIS and visual interpretation technics. This information has controlled with fieldwork in several campaigns. The rock glaciers are classified (in base of it activity) in actives, inactives and relict. The first and the second class were grouped in a category called intact rock glaciers for simplify it identification. The unified categories are water-storing. In the fieldwork have determinated the following aspects: 1- Active processes determination (needle ice, lenticular ice formation, etc.) and its sedimentary products: sucrose structure, inverted gradation, extrusion, open work gravels. 2- Location and geomorphologic measurement of rock glaciers and periglacial forms. There are identified 318 intact rock glaciers in high basin of Bermejo river, Sub-basins Condado river, Los Toldos-Lipeo river and Iruya river, Santa Victoria range. The actives rock glaciers, indicators of discontinuous permafrost, are installed from 4300 m s

  14. Monitoring basin-scale land cover changes in Kagera Basin of Lake Victoria using ancillary data and remote sensing (United States)

    Wasige, John E.; Groen, Thomas A.; Smaling, Eric; Jetten, Victor


    The Kagera Basin is a high value ecosystem in the Lake Victoria watershed because of the hydrological and food services it provides. The basin has faced large scale human induced land use and land cover changes (LUCC), but quantitative data is to date lacking. A combination of ancillary data and satellite imagery were interpreted to construct LUCC dynamics for the last century. This study is an initial step towards assessing the impact of LUCC on sustainable agriculture and water quality in the watershed. The results show that large trends of LUCC have rapidly occurred over the last 100 years. The most dominant LUCC processes were gains in farmland areas (not detectable in 1901 to 60% in 2010) and a net reduction in dense forest (7% to 2.6%), woodlands (51% to 6.9%) and savannas (35% to 19.6%) between 1901 and 2010. Forest degradation rapidly occurred during 1974 and 1995 but the forest re-grew between 1995 and 2010 due to forest conservation efforts. Afforestation efforts have resulted in plantation forest increases between 1995 and 2010. The rates of LUCC observed are higher than those reported in Sub Saharan Africa (SSA) and other parts of the world. This is one of the few studies in SSA at a basin scale that combines multi-source spatio-temporal data on land cover to enable long-term quantification of land cover changes. In the discussion we address future research needs for the area based on the results of this study. These research needs include quantifying the impacts of land cover change on nutrient and sediment dynamics, soil organic carbon stocks, and changes in biodiversity.

  15. Drainage Basins used for Development of the Watershed Regressions for Pesticides (WARP) Model, 2012 (United States)

    U.S. Geological Survey, Department of the Interior — This data set contains 204 drainage basin boundaries for U.S. Geological Survey (USGS) stream sites analyzed in the Watershed Regressions for Pesticides (WARP)...

  16. Drainage Basins used for Development of the Watershed Regressions for Pesticides (WARP) Model (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of 204 drainage basin boundaries for U.S. Geological Survey's (USGS) stream sites sampled in the National Water Quality Assessment (NAWQA)...

  17. Bedrock Geology of the turkey Creek Drainage Basin, Jefferson County, Colorado (United States)

    U.S. Geological Survey, Department of the Interior — This geospatial data set describes bedrock geology of the Turkey Creek drainage basin in Jefferson County, Colorado. It was digitized from maps of fault locations...

  18. LBA-ECO CD-06 Amazon River Basin Land and Stream Drainage Direction Maps (United States)

    National Aeronautics and Space Administration — ABSTRACT: This data set provides high-resolution (~500 m) gridded land and stream drainage direction maps for the Amazon River basin, excluding the Rio Tocantins...

  19. Key Watersheds in the Southeast Coast I&M Network (SECN) - Custom Drainage Basin Boundaries (United States)

    National Park Service, Department of the Interior — This dataset contains custom drainage basin polygons that are composed of the various watersheds (HUC-10) or subwatersheds (HUC-12) that contain water features that...

  20. Reconstruction of North American drainage basins and river discharge since the Last Glacial Maximum

    Directory of Open Access Journals (Sweden)

    A. D. Wickert


    Full Text Available Over the last glacial cycle, ice sheets and the resultant glacial isostatic adjustment (GIA rearranged river systems. As these riverine threads that tied the ice sheets to the sea were stretched, severed, and restructured, they also shrank and swelled with the pulse of meltwater inputs and time-varying drainage basin areas, and sometimes delivered enough meltwater to the oceans in the right places to influence global climate. Here I present a general method to compute past river flow paths, drainage basin geometries, and river discharges, by combining models of past ice sheets, glacial isostatic adjustment, and climate. The result is a time series of synthetic paleohydrographs and drainage basin maps from the Last Glacial Maximum to present for nine major drainage basins – the Mississippi, Rio Grande, Colorado, Columbia, Mackenzie, Hudson Bay, Saint Lawrence, Hudson, and Susquehanna/Chesapeake Bay. These are based on five published reconstructions of the North American ice sheets. I compare these maps with drainage reconstructions and discharge histories based on a review of observational evidence, including river deposits and terraces, isotopic records, mineral provenance markers, glacial moraine histories, and evidence of ice stream and tunnel valley flow directions. The sharp boundaries of the reconstructed past drainage basins complement the flexurally smoothed GIA signal that is more often used to validate ice-sheet reconstructions, and provide a complementary framework to reduce nonuniqueness in model reconstructions of the North American ice-sheet complex.

  1. A GIS-based approach in drainage morphometric analysis of Kanhar River Basin, India (United States)

    Rai, Praveen Kumar; Mohan, Kshitij; Mishra, Sameer; Ahmad, Aariz; Mishra, Varun Narayan


    The study indicates that analysis of morphometric parameters with the help of geographic information system (GIS) would prove a viable method of characterizing the hydrological response behaviour of the watershed. It is also well observed that remote sensing satellite data is emerging as the most effective, time saving and accurate technique for morphometric analysis of a basin. This technique is found relevant for the extraction of river basin and its stream networks through ASTER (DEM) in conjunction with remote sensing satellite data (Landsat etm+, 2013 and georeferenced survey of Indian toposheet, 1972). In this study, Kanhar basin a tributaries of Son River has been selected for detailed morphometric analysis. Seven sub-watersheds are also delineated within this basin to calculate the selected morphometric parameters. Morphometric parameters viz; stream order, stream length, bifurcation ratio, drainage density, stream frequency, form factor, circulatory ratio, etc., are calculated. The drainage area of the basin is 5,654 km2 and shows sub-dendritic to dendritic drainage pattern. The stream order of the basin is mainly controlled by physiographic and lithological conditions of the area. The study area is designated as seventh-order basin with the drainage density value being as 1.72 km/km2. The increase in stream length ratio from lower to higher order shows that the study area has reached a mature geomorphic stage.

  2. Morphometry Governs the Dynamics of a Drainage Basin: Analysis and Implications

    Directory of Open Access Journals (Sweden)

    Atrayee Biswas


    Full Text Available Mountainous rivers are the most significant source of water supply in the Himalayan provinces of India. The drainage basin dynamics of these rivers are controlled by the tectonomorphic parameters, which include both surface and subsurface characteristics of a basin. To understand the drainage basin dynamics and their usefulness in watershed prioritisation and management in terms of soil erosion studies and groundwater potential assessment and flood hazard risk reduction in mountainous rivers, morphometric analysis of a Himalayan River (Supin River basin has been taken as a case study. The entire Supin River basin has been subdivided into 27 subwatersheds and 36 morphometric parameters have been calculated under four broad categories: drainage network, basin geometry, drainage texture, and relief characteristics, each of which is further grouped into five different clusters having similar morphometric properties. The various morphometric parameters have been correlated with each other to understand their underlying relationship and control over the basin hydrogeomorphology. The result thus generated provides adequate knowledge base required for decision making during strategic planning and delineation of prioritised hazard management zones in mountainous terrains.

  3. Uncertainties in Flow-Duration-Frequency Relationships of High and Low Flow Extremes in Lake Victoria Basin


    Charles Onyutha; Patrick Willems


    This paper focuses on uncertainty analysis to aid decision making in applications of statistically modeled flow-duration-frequency (FDF) relationships of both daily high and low flows. The analysis is based on 24 selected catchments in the Lake Victoria basin in Eastern Africa. The FDF relationships were derived for aggregation levels in the range 1–90 days for high flows and 1–365 days for low flows. The validity of the projected FDF quantiles for high return periods T was checked using grow...

  4. Application of Satellite Observations to Manage Natural Disasters in the Lake Victoria Basin (United States)

    Habib, Shahid; Policelli, F.; Irwin, D.; Korme, Tesfaye; Adler, Bob; Hong, Yang


    Lake Victoria, the second largest fresh water lake in the Eastern part of Africa is a vital natural resource for the economic well being and prosperity of over 30 million people located in riparian regions of Uganda, Kenya and Tanzania. It covers a large area of about 68,870 km2 and produces a GDP of about US $30 billion per year. The region is also very much prone to natural disasters such as severe floods during heavy precipitation periods in the Eastern part of Africa. In addition to floods, the precipitation also produces large infestations of mosquito larvae due to the standing water in many areas. This further causes multiple vector borne diseases such as Malaria, Rift Valley Fever and more. These problems are of serious concern and require active and aggressive surveillance and management to minimize the loss of human and animal lives and property damage. Satellite imagery and observations along with the in situ measurements provide a great tool to analyze and study this area and inform the policy makers to make calculated policy decisions which are more beneficial to the environment. Recently, NASA and USAID have joined forces with the Regional Center for Mapping of Resources for Development (RCMRD) located in Nairobi, Kenya to utilize multiple NASA sensors such as TRMM, SRTM and MODIS to develop flood potential maps for the Lake Victoria Basin. The idea is to generate a flood forecasts and "nowcasts" that can be sent to the disaster management organizations of Uganda, Kenya, and Tanzania. Post flood event satellite imagery is becoming a common tool to assess the areas inundated by flooding. However, this work is unique undertaking by utilizing land imaging and atmospheric satellites to build credible flood potential maps. At same time, we are also studying the potential occurrence and spread of Rift Valley Fever disease based on the short term climate records and precipitation data. These activities require multi-nation coordination and agreements and

  5. Considerations about the drainage of transformers basins; Consideracoes sobre a drenagem das bacias dos transformadores

    Energy Technology Data Exchange (ETDEWEB)

    Guita, Mauro Arnoldo Macedo [Universidade Federal Fluminense, Niteroi, RJ (Brazil)


    There is a tendency in engineering of super-estimating the capacity to percolate fluids through granular materials, specially the large ones, so that many drainage devices are poorly detailed, with no numerical estimation of its performance. That is usual in the drainage of transformers basins. The author presents a case study where it can be observed and makes remarks about the problem 9 figs.

  6. Lymphatic drainage to the popliteal basin in distal lower extremity malignant melanoma. (United States)

    Menes, Tehillah S; Schachter, Jacob; Steinmetz, Adam P; Hardoff, Ruth; Gutman, Haim


    Hypotheses Melanoma of the distal lower extremity may drain to the popliteal basin. Drainage pathways and retrieval of the popliteal sentinel nodes may affect patient outcome. Retrospective analysis of popliteal involvement in patients with stage IB or higher melanoma, operated on from August 1, 1993, to July 31, 2003. Tertiary referral, university-affiliated medical center. One hundred six melanoma patients who underwent combined lymphoscintigraphy and blue dye-guided sentinel node biopsy, radical popliteal dissection, or both. Incidence and patterns of drainage to popliteal nodes; effect on staging and outcome. Lymphoscintigraphy (n = 8) and physical examination (n = 2) identified 10 cases (9%) of draining to the popliteal basin, with concurrent drainage to the groin. Three distinct drainage patterns were identified, with different popliteal node locations. Seven of 8 popliteal sentinel nodes were retrieved, 1 of which was metastatic with no groin metastasis. Two patients had synchronous palpable popliteal and groin metastases and underwent radical groin and popliteal dissection. All 3 patients with popliteal metastases relapsed early with synchronous systemic and in-transit disease. One of 7 patients with negative sentinel nodes is alive with in-transit disease; all others are disease free. According to this series, the popliteal basin is the site of first drainage in about 9% of patients, with concurrent drainage to the groin. The 3 distinct patterns of drainage to the popliteal region and the presence of isolated popliteal metastases may affect the surgical treatment. Therefore, drainage to popliteal sentinel nodes and the pattern of this drainage should be noted in all distal lower extremity melanomas.

  7. The legacy of lead (Pb) in fluvial bed sediments of an urban drainage basin, Oahu, Hawaii. (United States)

    Hotton, Veronica K; Sutherland, Ross A


    The study of fluvial bed sediments is essential for deciphering the impact of anthropogenic activities on water quality and drainage basin integrity. In this study, a systematic sampling design was employed to characterize the spatial variation of lead (Pb) concentrations in bed sediment of urban streams in the Palolo drainage basin, southeastern Oahu, Hawaii. Potentially bioavailable Pb was assessed with a dilute 0.5 N HCl extraction of the  Pukele (19) > Waiomao (8). Comparisons to sediment quality guidelines and potential toxicity estimates using a logistic regression model (LRM) indicated a significant potential risk of Palolo Stream bed sediments to bottom-dwelling organisms.

  8. Drainage water phosphorus losses in the great lakes basin (United States)

    The great lakes are one of the most important fresh water resources on the planet. While forestry is a primary land use throughout much of the great lakes basin, there are portions of the basin, such as much of the land that drains directly to Lake Erie, that are primarily agricultural. The primary ...

  9. Effects of drainage-basin geomorphology on insectivorous bird abundance in temperate forests. (United States)

    Iwata, Tomoya; Urabe, Jotaro; Mitsuhashi, Hiromune


    Interfaces between terrestrial and stream ecosystems often enhance species diversity and population abundance of ecological communities beyond levels that would be expected separately from both the ecosystems. Nevertheless, no study has examined how stream configuration within a watershed influences the population of terrestrial predators at the drainage-basin scale. We examined the habitat and abundance relationships of forest insectivorous birds in eight drainage basins in a cool temperate forest of Japan during spring and summer. Each basin has different drainage-basin geomorphology, such as the density and frequency of stream channels. In spring, when terrestrial arthropod prey biomass is limited, insectivorous birds aggregated in habitats closer to streams, where emerging aquatic prey was abundant. Nevertheless, birds ceased to aggregate around streams in summer because terrestrial prey became plentiful. Watershed-scale analyses showed that drainage basins with longer stream channels per unit area sustained higher densities of insectivorous birds. Moreover, such effects of streams on birds continued from spring through summer, even though birds dispersed out of riparian areas in the summer. Although our data are from only a single year, our findings imply that physical modifications of stream channels may reduce populations of forest birds; thus, they emphasize the importance of landscape-based management approaches that consider both stream and forest ecosystems for watershed biodiversity conservation. © 2010 Society for Conservation Biology.

  10. Seasonal and regional patterns in performance for a Baltic Sea Drainage Basin hydrologic model

    NARCIS (Netherlands)

    Lyon, S.W.; Meidani, Roya; Velde, van der Ype; Dahlke, H.E.; Swaney, D.P.; Mörth, Carl Magnus; Humborg, Christoph


    This study evaluates the ability of the Catchment SIMulation (CSIM) hydrologic model to describe seasonal and regional variations in river discharge over the entire Baltic Sea drainage basin (BSDB) based on 31 years of monthly simulation from 1970 through 2000. To date, the model has been

  11. Occurrence and distribution of hexabromocyclododecane in sediments from seven major river drainage basins in China. (United States)

    Li, Honghua; Shang, Hongtao; Wang, Pu; Wang, Yawei; Zhang, Haidong; Zhang, Qinghua; Jiang, Guibin


    The concentrations and geographical distribution of hexabromocyclododecane (HBCD) were investigated in 37 composite surface sediments from seven major river drainage basins in China, including Yangtze River, Yellow River, Pearl River, Liaohe River, Haihe River, Tarim River and Ertix River. The detection frequency of HBCD was 54%, with the concentrations ranged from below limit of detection (LOD) to 206 ng/g dry weight. In general, the geographical distribution showed increasing trends from the upper reaches to the lower reaches of the rivers and from North China to Southeast China. Compared to other regions in the world, the average concentration of HBCD in sediments from Yangtze River drainage basin was at relatively high level, whereas those from other six river drainage basins were at lower or similar level. The highest HBCD concentration in sediment from Yangtze River Delta and the highest detection frequency of HBCD in Pearl River drainage basins suggested that the industrial and urban activities could evidently affect the HBCD distribution. HBCD diastereoisomer profiles showed that gamma-HBCD dominated in most of the sediment samples, followed by alpha- and beta-HBCD, which was consistent with those in the commercial HBCD mixtures. Further risk assessment reflected that the average inventories of HBCD were 18.3, 5.87, 3.92, 2.50, 1.77 ng/cm2 in sediments from Pearl River, Haihe River, Tarim River, Yellow River and Yangtze River, respectively.

  12. 13 Morphometric Analysis of Ogunpa and Ogbere Drainage Basins ...

    African Journals Online (AJOL)


    basins with artificial paved surfaces with consequent effects on runoff production and sediment generation. (Akinola, 1966, Akintola,. 1974; Faniran, 1991). Major road. Dual carriage road. Express road. River. LEGEND. 0. 2km. Ojoo. Abadina. Sango. Apata. Oluyole. Estate. Felele. Academy. Iyaganku. Mokola. Coca-cola.


    Directory of Open Access Journals (Sweden)

    G. S. Mohamed


    as well as visual interpretation in conjunction with village cadastral maps has been studied. This research will be useful to consider creation of digital micro watershed atlas for management and protecting area affected by floods as well as for water and land resource management of the River basins in Queensland, New South Wales, South Australia and Victoria states of Australia. The research explains the need of using stream orders, delineation and codification micro watersheds based the principles of Dr.A.N.Khosla. This methodology was used in creation of web site of Districts soil water sheds atlas of Tamil Nadu state. With this principal of codification and delineation of watersheds based on stream order using stereo data of Cartosat 1 PAN 2.5 m data merged with Resourcesat LISS 4 data of 5.5m resolution and updating latest changes as on 2011 with non stereo Geo eye data of 0.5m resolution it is possible to create Australian micro water sheds GIS with deatils of streams with various stream orders, drainage pattern, slope, micro water sheds boundary in 1:5000 scale to manage the flood prone drainage basin in Australia. The High resolution data of satellites data apart from creation Micro watersheds GIS can be used for creation of Urban and Argicultural land parcel owenership details in Micro watershed GIS.

  14. Brief communication: Possible explanation of the values of Hack's drainage basin, river length scaling exponent (United States)

    Hunt, Allen G.


    Percolation theory can be used to find water flow paths of least resistance. Application of percolation theory to drainage networks allows identification of the range of exponent values that describe the tortuosity of rivers in real river networks, which is then used to generate the observed scaling between drainage basin area and channel length, a relationship known as Hack's law. Such a theoretical basis for Hack's law may allow interpretation of the range of exponent values based on an assessment of the heterogeneity of the substrate.

  15. Explanation of the values of Hack's drainage basin, river length scaling exponent (United States)

    Hunt, A. G.


    Percolation theory can be used to find water flow paths of least resistance. The application of percolation theory to drainage networks allows identification of the range of exponent values that describe the tortuosity of rivers in real river networks, which is then used to generate the observed scaling between drainage basin area and channel length, a relationship known as Hack's law. Such a theoretical basis for Hack's law allows interpretation of the range of exponent values based on an assessment of the heterogeneity of the substrate.

  16. Digital database architecture and delineation methodology for deriving drainage basins, and a comparison of digitally and non-digitally derived numeric drainage areas (United States)

    Dupree, Jean A.; Crowfoot, Richard M.


    The drainage basin is a fundamental hydrologic entity used for studies of surface-water resources and during planning of water-related projects. Numeric drainage areas published by the U.S. Geological Survey water science centers in Annual Water Data Reports and on the National Water Information Systems (NWIS) Web site are still primarily derived from hard-copy sources and by manual delineation of polygonal basin areas on paper topographic map sheets. To expedite numeric drainage area determinations, the Colorado Water Science Center developed a digital database structure and a delineation methodology based on the hydrologic unit boundaries in the National Watershed Boundary Dataset. This report describes the digital database architecture and delineation methodology and also presents the results of a comparison of the numeric drainage areas derived using this digital methodology with those derived using traditional, non-digital methods. (Please see report for full Abstract)

  17. Stable isotope paleoecology of Late Pleistocene Middle Stone Age humans from the Lake Victoria basin, Kenya. (United States)

    Garrett, Nicole D; Fox, David L; McNulty, Kieran P; Faith, J Tyler; Peppe, Daniel J; Van Plantinga, Alex; Tryon, Christian A


    Paleoanthropologists have long argued that environmental pressures played a key role in human evolution. However, our understanding of how these pressures mediated the behavioral and biological diversity of early modern humans and their migration patterns within and out of Africa is limited by a lack of archaeological evidence associated with detailed paleoenvironmental data. Here, we present the first stable isotopic data from paleosols and fauna associated with Middle Stone Age (MSA) sites in East Africa. Late Pleistocene (∼100-45 ka, thousands of years ago) sediments on Rusinga and Mfangano Islands in eastern Lake Victoria (Kenya) preserve a taxonomically diverse, non-analog faunal community associated with MSA artifacts. We analyzed the stable carbon and oxygen isotope composition of paleosol carbonate and organic matter and fossil mammalian tooth enamel, including the first analyses for several extinct bovids such as Rusingoryx atopocranion, Damaliscus hypsodon, and an unnamed impala species. Both paleosol carbonate and organic matter data suggest that local habitats associated with human activities were primarily riverine woodland ecosystems. However, mammalian tooth enamel data indicate that most large-bodied mammals consumed a predominantly C4 diet, suggesting an extensive C4 grassland surrounding these riverine woodlands in the region at the time. These data are consistent with other lines of paleoenvironmental evidence that imply a substantially reduced Lake Victoria at this time, and demonstrate that C4 grasslands were significantly expanded into equatorial Africa compared with their present distribution, which could have facilitated dispersal of human populations and other biotic communities. Our results indicate that early populations of Homo sapiens from the Lake Victoria region exploited locally wooded and well-watered habitats within a larger grassland ecosystem. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Ditches and Drainage Structures, Culverts - cross drains were collected using a GPS for drainage basin project. Ditches are planned for the future., Published in 2005, 1:2400 (1in=200ft) scale, Effingham County Government. (United States)

    NSGIC Local Govt | GIS Inventory — Ditches and Drainage Structures dataset current as of 2005. Culverts - cross drains were collected using a GPS for drainage basin project. Ditches are planned for...

  19. Drainage Basin Sensitivity to Climate Change in the Eastern Italian Alps (United States)

    Rathburn, S. L.; Comiti, F.; Brardinoni, F.; Sparacino, M.; Schook, D. M.


    In the past decades, increases in summer air temperatures generate glacial-melt floods with higher than normal magnitudes, increase the frequency of high intensity rainfall events, and lead to permafrost degradation of steep rocky slopes prone to mass wasting. Continued climatic warming has the potential to drastically increase the sediment supply to the channel network. A US-Italy collaboration is characterizing response domains for drainage basins undergoing deglaciation in the Italian Alps to develop sensitivity indices of changes in flow and sediment dynamics. Six glaciated basins 85-160 km2 in size within the upper Adige River Valley are analyzed. Three study basins have multi-year data on either the spatial distribution of mass wasting and sediment production or hydrology and sediment transport over snow and glacial melt, or both. The other three basins are tested for applicability of the sensitivity indices where field data are lacking. Preliminary results indicate basin lithology and degree of sediment connectivity are the dominant controls on drainage basin response. Four broadly applicable response domains incorporate metamorphic, sedimentary, or mixed bedrock lithology with high to low connectivity. The sensitivity indices for fluvial response are controlled by valley confinement and channel morphologic changes. A historic topographic map from 1858 provides qualitative channel geometry information at the end of the Little Ice Age and glacial extent for all basins. Aerial photographs from 1945, 1954, 1971, and lidar and imagery from 2005 or 2011, along with field verification quantify valley confinement, braiding index and sediment connectivity. Key controls on sediment delivery to channels include glacially-inherited topography and the distribution of glacigenic surficial materials. Sediment cascade modeling will identify sediment sources, pathways and sinks and provide a first order understanding of basin-scale response to climate change.

  20. A study case of Baranca drainage basin flash-floods using the hydrological model of Hec-Ras

    National Research Council Canada - National Science Library

    Aritina HALIUC; Alexandru FRANTIUC


    .... The Baranca brook which drains a considerable part of Zamostea village (Romania) was used as a pilot drainage basin for the flash-flood simulation using the Hec-Ras program and the Arcgis extension, HecGeo-Ras...

  1. Drainage Basins Used for Assessing Trends in Concentration of Pesticides in Streams of the United States, 1992-2010 (United States)

    U.S. Geological Survey, Department of the Interior — This dataset consists of drainage basin boundaries for 212 U.S. Geological Survey (USGS) stream sites sampled in the National Water-Quality Assessment (NAWQA)...

  2. Regional modeling of the Shirase drainage basin, East Antarctica: full Stokes vs. shallow ice dynamics (United States)

    Seddik, Hakime; Greve, Ralf; Zwinger, Thomas; Sugiyama, Shin


    A hierarchy of approximations of the force balance for the flow of grounded ice exists, ranging from the most sophisticated full Stokes (FS) formulation to the most simplified shallow ice approximation (SIA). Both are implemented in the ice flow model Elmer/Ice, and we compare them by applying the model to the East Antarctic Shirase drainage basin. First, we apply the control inverse method to infer the distribution of basal friction with FS. We then compare FS and SIA by simulating the flow of the drainage basin under present-day conditions and for three scenarios 100 years into the future defined by the SeaRISE (Sea-level Response to Ice Sheet Evolution) project. FS reproduces the observed flow pattern of the drainage basin well, in particular the zone of fast flow near the grounding line, while SIA generally overpredicts the surface velocities. As for the transient scenarios, the ice volume change (relative to the constant-climate control run) of the surface climate experiment is nearly the same for FS and SIA, while for the basal sliding experiment (halved basal friction), the ice volume change is ˜ 30 % larger for SIA than for FS. This confirms findings of earlier studies that, in order to model ice sheet areas containing ice streams and outlet glaciers with high resolution and precision, careful consideration must be given to the choice of a suitable force balance.

  3. Disaster mitigation at drainage basin of Kuranji Padang City (United States)

    Utama, L.; Yamin, M.


    Floods is flooding of effect of exit water groove river because big river debit sudden its accomodation energy, happened swiftly knock over areas which is debasement, in river basin and hollow. Flow debris or which is recognized with galodo have knock over river of Kuranji year 2012 in Padang city. Area is floods disaster are: 19 Sub-District in 7 district, and hard that is district of Pauh and district of Nanggalo. Governmental claim tired loss of Rp 263,9 Billion while Government of Provinsi West Sumatera appraise loss estimated by Fourty Billion Rupiah (Padang Ekspress 28 July 2012), with detail of damage house counted 878 unit, damage religious service house 15 unit, damage irrigation 12 unit, damage bridge 6 unit, damage school 2 unit, damage health post 1 unit. Result of calculation, by using rainfall of year 2003 until year 2015 with method Gumbel, Hasper and Wedwen, got high rainfall plan is 310,00 mm, and method Melchior and Hasper floods is 1125,86 m³ / second. From result of study analyse at Citra map of correlation and image to parameters cause of floods, and use software Watershed Modelling System (WMS) this region have two class that is middle susceptance and low susceptance. Middle susceptance area is there are in middle river and downstream river, with inclination level off. Low susceptance area there is middle river. Area which have potency result the happening of floods is headwaters, because having keen ramp storey level ( 45 - 55%) and is hilly. For the mitigasi of floods disaster determined by three area evacuate that are: Sub-District Of Kelurahan Limau Manis District Of Pauh, Sub-District Of Surau Gadang District Of Nanggalo, and Sub-District Of Lambung Bukik District of Pauh, in the form of map.

  4. Methodology for the establishment of physical and geometric properties of a drainage basin

    Directory of Open Access Journals (Sweden)

    Petr Pelikán


    Full Text Available Factors which affect runoff are closely related to properties of the basin from which the water flows and its environment. They have an effect not only on the size of the runoff but also its origination and mainly its temporal distribution. These factors can be divided into two main groups. The first group contains climatic factors, which are besides precipitation meteorological quantities affecting the overall evaporation of water in the drainage basin. These include the actual temporal and spatial progress of a rainfall, the moisture of air, evaporation, air temperature, the velocity and direction of wind, atmospheric pressure, etc. The other group consists of geographic factors of the drainage basin, which describe the environment in which the process of runoff occurs.The presented study focuses on a theoretical analysis of physical and geometric properties of a basin, the practical methods and the possible ways of their determination and possible uses of results. In the past the determination of physical a geometric watershed attributes had been working out on the basis of analogue maps. These methods were very labour-intensive and lengthy. The report deals with new determination methods based on digital data processing – utilization of digital terrain model (DTM. These problems are quite actual because of research of rainfall-runoff process, flood process and soil erosion within watershed.

  5. The population structure of Glossina fuscipes fuscipes in the Lake Victoria basin in Uganda: implications for vector control

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    Hyseni Chaz


    Full Text Available Abstract Background Glossina fuscipes fuscipes is the primary vector of trypanosomiasis in humans and livestock in Uganda. The Lake Victoria basin has been targeted for tsetse eradication using a rolling carpet initiative, from west to east, with four operational blocks (3 in Uganda and 1 in Kenya, under a Pan-African Tsetse and Trypanosomiasis Eradication Campaign (PATTEC. We screened tsetse flies from the three Ugandan PATTEC blocks for genetic diversity at 15 microsatellite loci from continental and offshore populations to provide empirical data to support this initiative. Methods We collected tsetse samples from 11 sites across the Lake Victoria basin in Uganda. We performed genetic analyses on 409 of the collected tsetse flies and added data collected for 278 individuals in a previous study. The flies were screened across 15 microsatellite loci and the resulting data were used to assess the temporal stability of populations, to analyze patterns of genetic exchange and structuring, to estimate dispersal rates and evaluate the sex bias in dispersal, as well as to estimate demographic parameters (NE and NC. Results We found that tsetse populations in this region were stable over 4-16 generations and belong to 4 genetic clusters. Two genetic clusters (1 and 2 corresponded approximately to PATTEC blocks 1 and 2, while the other two (3 and 4 fell within PATTEC block 3. Island populations grouped into the same genetic clusters as neighboring mainland sites, suggesting presence of gene flow between these sites. There was no evidence of the stretch of water separating islands from the mainland forming a significant barrier to dispersal. Dispersal rates ranged from 2.5 km per generation in cluster 1 to 14 km per generation in clusters 3 and 4. We found evidence of male-biased dispersal. Few breeders are successfully dispersing over large distances. Effective population size estimates were low (33–310 individuals, while census size estimates

  6. Benthic macroinvertebrate community in the Sinos river drainage basin, Rio Grande do Sul, Brazil

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    M. P. Barros

    Full Text Available Abstract Aquatic macroinvertebrate fauna is a relevant component of limnic continental aquatic ecosystems, playing an important role in several processes with relevant biocomplexity. The present study characterized the benthic macroinvertebrate fauna found in three hydric bodies in the Sinos river drainage basin regarding community structure. Sample was collected from January to December 2013 in three locations in the basin: the city of Caraá (29 °45’45.5”S/50°19’37.3”W, the city of Rolante (29°38’34.4”S/50°32’33.2”W and the city of Igrejinha (29°36’10.84”S/50°48’49.3”W. Abiotic components (pH, dissolved oxygen and temperature were registered and collected samples were identified up to family type. Average annual pH, dissolved oxygen and temperature were similar in all locations. A total of 26,170 samples were collected. Class Insecta (Arthropods represented 85.5% of total sample. Platyhelmintes, Mollusca and Annelida samples were also registered. A total of 57 families were identified for the drainage basin and estimators (Chao-1, Chao-2 and jackknife 2 estimated richness varying from 60 to 72 families.

  7. The Development of a Customization Framework for the WRF Model over the Lake Victoria Basin, Eastern Africa on Seasonal Timescales

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    R. Argent


    Full Text Available Lake Victoria, Africa, supports millions of people. To produce reliable climate projections, it is desirable to successfully model the rainfall over the lake accurately. An initial step is taken here with customization of the Weather, Research, and Forecast (WRF model. Of particular interest is an asymmetrical rainfall pattern across the lake basin, due to a diurnal land-lake breeze. The main aim is to present a customization framework for use over the lake. This framework is developed by conducting several series of model runs to investigate aspects of the customization. The runs are analyzed using Tropical Rainfall Measuring Mission rainfall data and Climatic Research Unit temperature data. The study shows that the choice of parameters and lake surface temperature initialization can significantly alter the results. Also, the optimal physics combinations for the climatology may not necessarily be suitable for all circumstances, such as extreme years. The study concludes that WRF is unable to reproduce the pattern across the lake. The temperature of the lake is too cold and this prevents the diurnal land-lake breeze reversal. Overall, this study highlights the importance of customizing a model to the region of research and presents a framework through which this may be achieved.

  8. Bulinus globosus (Planorbidae; Gastropoda) populations in the Lake Victoria basin and coastal Kenya show extreme nuclear genetic differentiation. (United States)

    Nyakaana, Silvester; Stothard, J Russell; Nalugwa, Allen; Webster, Bonnie L; Lange, Charles N; Jørgensen, Aslak; Rollinson, David; Kristensen, Thomas K


    Bulinus globosus, a key intermediate host for Schistosoma haematobium that causes urinary schistosomiasis, is a hermaphroditic freshwater Planorbid snail species that inhabits patchy and transient water bodies prone to large seasonal variations in water availability. Although capable of self-fertilizing, this species has been reported to be preferentially out crossing. In this study, we characterized the population genetic structure of 19 B. globosus populations sampled across the Lake Victoria basin and coastal Kenya using four polymorphic microsatellite loci. Population genetic structure was characterized and quantified using FST statistics and Bayesian clustering algorithms. The four loci used in this study contained sufficient statistical power to detect low levels of population genetic differentiation and were highly polymorphic with the number of alleles per locus across populations ranging from 16 to 22. Average observed and expected heterozygosities across loci in each population ranged from 0.13 to 0.69 and from 0.39 to 0.79, respectively. Twenty-five of the seventy-six possible population-locus comparisons significantly deviated from Hardy-Weinberg equilibrium proportions after Bonferroni corrections, mostly due to the deficiency of heterozygotes. Significant genetic differentiation was observed between populations and Bayesian inferences identified 15 genetic clusters. The excess homozygosity, significant inbreeding and population genetic differentiation observed in B. globosus populations are likely to be due to the habitat patchiness, mating system and the proneness to cyclic extinction and recolonization in transient habitats. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Schistosomes of small mammals from the Lake Victoria Basin, Kenya: new species, familiar species, and implications for schistosomiasis control. (United States)

    Hanelt, B; Mwangi, I N; Kinuthia, J M; Maina, G M; Agola, L E; Mutuku, M W; Steinauer, M L; Agwanda, B R; Kigo, L; Mungai, B N; Loker, E S; Mkoji, G M


    Recent schistosomiasis control efforts in sub-Saharan Africa have focused nearly exclusively on treatment of humans with praziquantel. However, the extent to which wild mammals act as reservoirs for Schistosoma mansoni and therefore as sources of renewed transmission following control efforts is poorly understood. With the objective to study the role of small mammals as reservoir hosts, 480 animals belonging to 9 rodent and 1 insectivore species were examined for infection with schistosomes in Kisumu, in the Lake Victoria Basin, Kenya. Animals were collected from 2 sites: near the lakeshore and from Nyabera Marsh draining into the lake. A total of 6.0% of the animals captured, including 5 murid rodent species and 1 species of shrew (Crocidura olivieri) were infected with schistosomes. Four schistosome species were recovered and identified using cox1 DNA barcoding: S. mansoni, S. bovis, S. rodhaini and S. kisumuensis, the latter of which was recently described from Nyabera Marsh. Schistosoma mansoni and S. rodhaini were found infecting the same host individual (Lophuromys flavopunctatus), suggesting that this host species could be responsible for the production of hybrid schistosomes found in the area. Although the prevalence of S. mansoni infection in these reservoir populations was low (1.5%), given their potentially vast population size, their impact on transmission needs further study. Reservoir hosts could perpetuate snail infections and favour renewed transmission to humans once control programmes have ceased.

  10. Uncertainties in Flow-Duration-Frequency Relationships of High and Low Flow Extremes in Lake Victoria Basin

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    Charles Onyutha


    Full Text Available This paper focuses on uncertainty analysis to aid decision making in applications of statistically modeled flow-duration-frequency (FDF relationships of both daily high and low flows. The analysis is based on 24 selected catchments in the Lake Victoria basin in Eastern Africa. The FDF relationships were derived for aggregation levels in the range 1–90 days for high flows and 1–365 days for low flows. The validity of the projected FDF quantiles for high return periods T was checked using growth factor curves. Monte Carlo simulations were used to construct confidence intervals CI on both the estimated Ts for given flows and the estimated FDF quantiles for given T. The average bias of the modeled T of high and low flows are for all catchments and Ts up to 25 years lower than 8%. Despite this relatively small average bias in the modeled T, the limits of the CI on the modeled 25-year flows go up to more than 100% for high flows and more than 150% for low flows. The assessed FDF relationships and accompanied uncertainties are useful for various types of risk based water engineering and water management applications related to floods and droughts.

  11. Effects of Drainage basin property and geological dip - strike angle on Landslide (United States)

    Kawabata, D.


    The recent spread of GIS and high-precision DEM has been making rapid and extensive topographical measurements feasible. GIS is helpful tool to analysis of landslide probability and make landslide hazard map. We have investigated that the altitude-slope relationship for each geological unit (e.g. sandstone-dominant, mudstone-dominant, sandstone-mudstone alternation) in the Southern Japanese Alps. This result shows that terrains underlain by some specific rocks, however, are highly susceptible to landslides and thus have markedly reduced slope angles than other terrains with similar altitudes. It is another result of our investigation that the characteristics slope failures like toppling is difference from landslides. In our study, it is not clear of the relationship of dip angle of the geology and aspect in landslide area. In addition to this subject, the problem which we consider next is what the other factor decides landslide distribution. Relationship drainage basin and landslide is focused in this study. The results of morphometric measurement, over 70% landslides are on the geological boundary. The slope angle of landslide area is 10-15% lower than dip angle of geological unit. The dip angle direction of geological unit shows similar trend of aspect of landslide. Many Landslides are on the low drainage density and high slope angle area. Drainage density is low and it has large area in geological unit include many landslides. These results show that landslides are easy to cause in a place like similar dip direction and dip angle of the geological unit. It is likely that landslides tend to cause in the place where material is different. Large drainage basin and high slope angle effects on landslide distribution.

  12. The rise and fall of water hyacinth in Lake Victoria and the Kagera River basin, 1989-2001 (United States)

    Albright, Thomas P.; Moorhouse, T.G.; McNabb, T.J.


    Water hyacinth (Eichhornia crassipes (Mart.) Solms) is an invasive aquatic macrophyte associated with major negative economic and ecological impacts to the Lake Victoria region since the plant's establishment in Uganda in the 1980s. Reliable estimates of water hyacinth distribution and extent are required to gauge the severity of the problem through time, relate water hyacinth abundance to environmental factors, identify areas requiring management action, and assess the efficacy of management actions. To provide such estimates and demonstrate the utility of remote sensing for this application, we processed and analyzed remotely sensed imagery to determine the distribution and extent of water hyacinth. Maps were produced and coverage was quantified using a hybrid unsupervised image classification approach with manual editing for each of the riparian countries of Kenya, Tanzania, and Uganda, as well as for numerous gulfs and bays. A similar procedure was carried out for selected lakes in the Rwanda-Tanzania borderlands lakes region in the Kagera River basin. Results confirm the severity of the water hyacinth infestation, especially in the northern parts of the lake. A maximum lake-wide extent of at least 17,374 ha was attained in 1998. Following this, a combination of factors, including conditions associated with the 1997 to 1998 El Nin??o and biocontrol with water hyacinth weevils, appear to have contributed to a major decline in water hyacinth in the most affected parts of the lake. Some lakes in the Kagera basin, such as Lake Mihindi, Rwanda, were severely infested in the late 1990s, but the level of infestation in most of these decreased markedly by the early 2000s.

  13. Assessment of waterlogging in agricultural megaprojects in the closed drainage basins of the Western Desert of Egypt (United States)

    El Bastawesy, M.; Ramadan Ali, R.; Faid, A.; El Osta, M.


    This paper investigates the development of waterlogging in the cultivated and arable areas within typical dryland closed drainage basins (e.g. the Farafra and Baharia Oases), which are located in the Western Desert of Egypt. Multi-temporal remote sensing data of the Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper (ETM+) were collected and processed to detect the land cover changes; cultivations, and the extent of water ponds and seepage channels. The Shuttle Radar Topography Mission (SRTM) digital elevation model (DEM) has been processed to delineate the catchment morphometrical parameters (i.e. drainage networks, catchment divides and surface areas of different basins) and to examine the spatial distribution of cultivated fields and their relation to the extracted drainage networks. The soil of these closed drainage basins is mainly shallow and lithic with high calcium carbonate content; therefore, the downward percolation of excess irrigation water is limited by the development of subsurface hardpan, which also saturates the upper layer of soil with water. The subsurface seepage from the newly cultivated areas in the Farafra Oasis has revealed the pattern of buried alluvial channels, which are waterlogged and outlined by the growth of diagnostic saline shrubs. Furthermore, the courses of these waterlogged channels are coinciding with their counterparts of the SRTM DEM, and the recent satellite images show that the surface playas in the downstream of these channels are partially occupied by water ponds. On the other hand, a large water pond has occupied the main playa and submerged the surrounding fields, as a large area has been cultivated within a relatively small closed drainage basin in the Baharia Oasis. The geomorphology of closed drainage basins has to be considered when planning for a new cultivation in dryland catchments to better control waterlogging hazards. The "dry-drainage" concept can be implemented as the drainage and seepage water can be

  14. Assessment of waterlogging in agricultural megaprojects in the closed drainage basins of the Western Desert of Egypt

    Directory of Open Access Journals (Sweden)

    M. El Bastawesy


    Full Text Available This paper investigates the development of waterlogging in the cultivated and arable areas within typical dryland closed drainage basins (e.g. the Farafra and Baharia Oases, which are located in the Western Desert of Egypt. Multi-temporal remote sensing data of the Landsat Thematic Mapper (TM and Enhanced Thematic Mapper (ETM+ were collected and processed to detect the land cover changes; cultivations, and the extent of water ponds and seepage channels. The Shuttle Radar Topography Mission (SRTM digital elevation model (DEM has been processed to delineate the catchment morphometrical parameters (i.e. drainage networks, catchment divides and surface areas of different basins and to examine the spatial distribution of cultivated fields and their relation to the extracted drainage networks. The soil of these closed drainage basins is mainly shallow and lithic with high calcium carbonate content; therefore, the downward percolation of excess irrigation water is limited by the development of subsurface hardpan, which also saturates the upper layer of soil with water. The subsurface seepage from the newly cultivated areas in the Farafra Oasis has revealed the pattern of buried alluvial channels, which are waterlogged and outlined by the growth of diagnostic saline shrubs. Furthermore, the courses of these waterlogged channels are coinciding with their counterparts of the SRTM DEM, and the recent satellite images show that the surface playas in the downstream of these channels are partially occupied by water ponds. On the other hand, a large water pond has occupied the main playa and submerged the surrounding fields, as a large area has been cultivated within a relatively small closed drainage basin in the Baharia Oasis. The geomorphology of closed drainage basins has to be considered when planning for a new cultivation in dryland catchments to better control waterlogging hazards. The "dry-drainage" concept can be implemented as the drainage and

  15. Hinterland tectonics and drainage evolution recorded by foreland basin archives: the Neogene Siwaliks of the Himalaya (United States)

    Huyghe, Pascale; van der Beek, Peter; Matthias, Bernet; Catherine, Chauvel; Jean-Louis, Mugnier; Laurent, Husson; François, Chirouze


    Provenance analysis and detrital thermochronology of detrital synorogenic sediments, derived from erosion of mountain belts and deposited in surrounding sedimentary basins, are well-established methods to examine the exhumation history of convergent zones, tectonic activity and the associated evolution of the drainage network. We have conducted multidisciplinary studies on magnetostratigraphically dated sections throughout the Neogene Siwalik foreland basin of the Himalayan belt since more than 10 years. Sr, Nd and Hf isotopes are used as provenance indicators, providing information on the nature and size of catchment basins and their evolution through time in response to tectonics. Detrital zircon and apatite thermochronology provides constraints on exhumation rates in the hinterland of the Himalaya and the deformation of the Sub-Himalayan foreland basin. Throughout the Himalaya, detrital zircons from the Siwaliks generally show three age peaks: two static peaks (i.e., displaying constant peak ages through time), and a moving peak. The latter shows a constant lag time of ~4 m.y. corresponding to source-area exhumation rates on the order of 1.8 km/my, while the two static peaks respectively reveal a major 15-20 Ma exhumation event in the belt, the significance of which is still debated, and inheritance of pre-Himalayan ages that indicate recycling of Tethyan sediments. Therefore, our ZFT results suggest that the exhumation dynamics are broadly similar throughout the Himalaya since at least 13 m.y, as also shown by the Bengal Fan detrital sediment record. We relate this switch in tectonic regime to the destabilization of the Himalayan wedge that is rendered overcritical as a response to the transience of dynamic topography caused by the deforming underlying Indian slab. Nonetheless, in detail, the timing of thrusting in the Siwalik domain is delayed by about 1 my eastward as demonstrated by both structural and apatite fission-track data, suggesting overall eastward

  16. Modelling the distribution of detrital cosmogenic nuclide concentrations: a new tool to study drainage basin evolution. (United States)

    Codilean, A. T.; Hoey, T. B.; Bishop, P.; Stuart, F. M.; Fabel, D.; Willgoose, G. R.


    Cosmogenic nuclide concentrations (CNCs) in alluvial sediments are now routinely being used to estimate time- and space-averaged drainage basin denudation rates but have the potential to offer considerably more. This is because each grain leaving a drainage basin has a potentially unique history of erosion, transport and storage, meaning that the distribution of CNCs in large numbers of grains can provide an integrated signature of the basin's geomorphic history. We use a numerical model describing cosmogenic nuclide acquisition in sediments moving through an arid- zone drainage basin to explore the sensitivity of alluvial CNC distributions to assumptions about the geomorphic settings of the sediment's source areas. The model fully accounts for variations in nuclide production due to changes in latitude, altitude and topographic shielding and allows for spatially variable erosion and sediment transport rates. Data for model validation are provided by measurements of cosmogenic 21Ne concentrations in 32 16-22 mm diameter quartzite clasts from a 200 m reach of the Gaub river (a tributary of the Kuiseb, Namibia) along with measurements of cosmogenic 10Be in 12 amalgamated fluvial sediment samples from the outlets of the Gaub's tributaries. Model results show that detrital CNC distributions are highly sensitive to the geomorphic settings of the sediments' source areas and have the potential to be able to differentiate tectonic settings and/or geomorphic histories. The clast 21Ne concentrations vary between 2.6×106 and 1.6×108 atoms/g and exhibit a non-Gaussian distribution. The shape of this distribution, also predicted by the model, confirms the non-random nature of detrital CNC acquisition. These results also emphasise the importance of the assumptions made when using cosmogenic nuclides to estimate basin-wide denudation rates. The non- Gaussian distribution shows that the assumption of random inheritance of CNCs in the sediments cannot always be made, such that

  17. Modeling pollution potential input from the drainage basin into Barra Bonita reservoir, São Paulo - Brazil. (United States)

    Prado, R B; Novo, E M L M


    In this study multi-criteria modeling tools are applied to map the spatial distribution of drainage basin potential to pollute Barra Bonita Reservoir, São Paulo State, Brasil. Barra Bonita Reservoir Basin had undergone intense land use/land cover changes in the last decades, including the fast conversion from pasture into sugarcane. In this respect, this study answers to the lack of information about the variables (criteria) which affect the pollution potential of the drainage basin by building a Geographic Information System which provides their spatial distribution at sub-basin level. The GIS was fed by several data (geomorphology, pedology, geology, drainage network and rainfall) provided by public agencies. Landsat satellite images provided land use/land cover map for 2002. Ratings and weights of each criterion defined by specialists supported the modeling process. The results showed a wide variability in the pollution potential of different sub-basins according to the application of different criterion. If only land use is analyzed, for instance, less than 50% of the basin is classified as highly threatening to water quality and include sub basins located near the reservoir, indicating the importance of protection areas at the margins. Despite the subjectivity involved in the weighing processes, the multi-criteria analysis model allowed the simulation of scenarios which support rational land use polices at sub-basin level regarding the protection of water resources.

  18. Impact of multiple lymphatic channel drainage to a single nodal basin on outcomes in melanoma. (United States)

    Wall, James K; Florero, Marilyn; Accortt, Neil A; Allen, Robert; Kashani-Sabet, Mohamed; Morita, Eugene; Leong, Stanley P L


    To determine the impact of multiple lymphatic channels (MLCs) on outcome in melanoma. Retrospective cohort study. Academic tertiary care center. Of 1198 consecutive selective sentinel lymphadenectomies performed from 1995 to 2000 for primary invasive melanoma, 502 patients were identified with extremity or truncal melanoma that drained to a single nodal basin. Three cohorts were formed based on lymphatic channels (none, single, and multiple). Tumors with drainage to multiple nodal basins as well as all head and neck tumors were excluded. Multiple variables, including patterns of lymphatic drainage, were analyzed for impact on disease-free and overall survival. Demographics were similar among groups, with a median follow-up of 5.6 years. Univariate analysis revealed MLCs as an independent risk factor for both disease-free (P = .04) and overall survival (P = .003). Multivariate analysis confirmed that tumor depth, sentinel lymph node status, and MLCs were risk factors for both disease-free and overall survival. Kaplan-Meier analysis showed worse survival in the MLCs group. Our study reveals that MLCs are an independent risk factor for recurrence and mortality in melanoma. Multiple lymphatic channels may facilitate the process of metastasis.

  19. Assessment of Wetland Hydrological Dynamics in a Modified Catchment Basin: Case of Lake Buninjon, Victoria, Australia. (United States)

    Yihdego, Yohannes; Webb, John A


      The common method to estimate lake levels is the water balance equation, where water input and output result in lake storage and water level changes. However, all water balance components cannot always be quickly assessed, such as due to significant modification of the catchment area. A method that assesses general changes in lake level can be a useful tool in examining why lakes have different lake level variation patterns. Assessment of wetlands using the dynamics of the historical hydrological and hydrogeological data set can provide important insights into variations in wetland levels in different parts of the world. A case study from a saline landscape, Lake Buninjon, Australia, is presented. The aim of the present study was to determine how climate, river regime, and lake hydrological properties independently influence lake water levels and salinity, leaving the discrepancy, for the effect of the non-climatic/catchment modification in the past and the model shows that surface inflow is most sensitive variable. The method, together with the analysis and interpretation, might be of interest to wider community to assess its response to natural/anthropogenic stress and decision choices for its ecological, social, scientific value, and mitigation measures to safe guard the wetland biodiversity in a catchment basin.

  20. Cryogenic brines as diagenetic fluids: Reconstructing the diagenetic history of the Victoria Land Basin using clumped isotopes (United States)

    Staudigel, Philip T.; Murray, Sean; Dunham, Daniel P.; Frank, Tracy D.; Fielding, Christopher R.; Swart, Peter K.


    The isotopic analyses (δ13C, δ18O, and Δ47) of carbonate phases recovered from a core in McMurdo Sound by ANtarctic geologic DRILLing (ANDRILL-2A) indicate that the majority of secondary carbonate mineral formation occurred at cooler temperatures than the modern burial temperature, and in the presence of fluids with δ18Owater values ranging between -11 and -6‰ VSMOW. These fluids are interpreted as being derived from a cryogenic brine formed during the freezing of seawater. The Δ47 values were converted to temperature using an in-house calibration presented in this paper. Measurements of the Δ47 values in the cements indicate increasingly warmer crystallization temperatures with depth and, while roughly parallel to the observed geothermal gradient, consistently translate to temperatures that are cooler than the current burial temperature. The difference in temperature suggests that cements formed when they were ∼260 ± 100 m shallower than at the present day. This depth range corresponds to a period of minimal sediment accumulation from 3 to 11 Myr; it is therefore interpreted that the majority of cements formed during this time. This behavior is also predicted by time-integrated modeling of cementation at this site. If this cementation had occurred in the presence of these fluids, then the cryogenic brines have been a longstanding feature in the Victoria Land Basin. Brines such as those found at this site have been described in numerous modern high-latitude settings, and analogous fluids could have played a role in the diagenetic history of other ice-proximal sediments and basins during glacial intervals throughout geologic history. The agreement between the calculated δ18Owater value and the measured values in the pore fluids shows how the Δ47 proxy can be used to identify the origin of negative δ18O values in carbonate rocks and that extremely negative values do not necessarily need to be a result of the influence of meteoric fluids or reaction at

  1. Temporal-spatial evolution of the hydrologic drought characteristics of the karst drainage basins in South China (United States)

    He, Zhonghua; Liang, Hong; Yang, Chaohui; Huang, Fasu; Zeng, Xinbo


    Hydrologic drought, as a typical natural phenomenon in the context of global climate change, is the extension and development of meteorological and agricultural droughts, and it is an eventual and extreme drought. This study selects 55 hydrological control basins in Southern China as research areas. The study analyzes features, such as intensity and occurrence frequency of hydrologic droughts, and explores the spatial-temporal evolution patterns in the karst drainage basins in Southern China by virtue of Streamflow Drought Index. Results show that (1) the general hydrologic droughts from 1970s to 2010s exhibited ;an upward trend after having experienced a previous decline; in the karst drainage basins in Southern China; the trend was mainly represented by the gradual alleviation of hydrologic droughts from 1970s to 1990s and the gradual aggravation from 2000s to 2010s. (2) The spatial-temporal evolution pattern of occurrence frequency in the karst drainage basins in Southern China was consistent with the intensity of hydrologic droughts. The periods of 1970s and 2010s exhibited the highest occurrence frequency. (3) The karst drainage basins in Southern China experienced extremely complex variability of hydrologic droughts from 1970s to 2010s. Drought intensity and occurrence frequency significantly vary for different types of hydrology.

  2. Geodatabase of sites, basin boundaries, and topology rules used to store drainage basin boundaries for the U.S. Geological Survey, Colorado Water Science Center (United States)

    Dupree, Jean A.; Crowfoot, Richard M.


    This geodatabase and its component datasets are part of U.S. Geological Survey Digital Data Series 650 and were generated to store basin boundaries for U.S. Geological Survey streamgages and other sites in Colorado. The geodatabase and its components were created by the U.S. Geological Survey, Colorado Water Science Center, and are used to derive the numeric drainage areas for Colorado that are input into the U.S. Geological Survey's National Water Information System (NWIS) database and also published in the Annual Water Data Report and on NWISWeb. The foundational dataset used to create the basin boundaries in this geodatabase was the National Watershed Boundary Dataset. This geodatabase accompanies a U.S. Geological Survey Techniques and Methods report (Book 11, Section C, Chapter 6) entitled "Digital Database Architecture and Delineation Methodology for Deriving Drainage Basins, and Comparison of Digitally and Non-Digitally Derived Numeric Drainage Areas." The Techniques and Methods report details the geodatabase architecture, describes the delineation methodology and workflows used to develop these basin boundaries, and compares digitally derived numeric drainage areas in this geodatabase to non-digitally derived areas. 1. COBasins.gdb: This geodatabase contains site locations and basin boundaries for Colorado. It includes a single feature dataset, called BasinsFD, which groups the component feature classes and topology rules. 2. BasinsFD: This feature dataset in the "COBasins.gdb" geodatabase is a digital container that holds the feature classes used to archive site locations and basin boundaries as well as the topology rules that govern spatial relations within and among component feature classes. This feature dataset includes three feature classes: the sites for which basins have been delineated (the "Sites" feature class), basin bounding lines (the "BasinLines" feature class), and polygonal basin areas (the "BasinPolys" feature class). The feature dataset

  3. Classification scheme for acid rock drainage detection - the Hamersley Basin, Western Australia (United States)

    Skrzypek, Grzegorz; Dogramaci, Shawan; McLean, Laura


    In arid environment where precipitation and surface water are very limited, groundwater is the most important freshwater resource. For this reasons it is intensively exploited and needs to be managed wisely and protected from pollutants. Acid rock drainage often constitutes a serious risk to groundwater quality, particularly in catchments that are subject to mining, large scale groundwater injection or abstraction. However, assessment of the potential acid rock drainage risk can be challenging, especially in carbonate rich environment, where the decreasing pH that usually accompanies pyrite oxidation, can be masked by the high pH-neutralisation capacity of carbonate minerals. In this study, we analysed 73 surface and groundwater samples from different water bodies and aquifers located in the Hamersley Basin, Western Australia. Although the majority of samples had a neutral pH, there was a large spatial variability in the dissolved sulphate concentrations that ranged from 1 mg/L to 15,000 mg/L. Waters with high dissolved sulphate concentration were found in areas with a high percentage of sulphide minerals (e.g. pyrite) located within the aquifer matrix and were characterised by low δ34SSO4 values (+1.2‰ to +4.6) consistent with signatures of aquifer matrix pyritic rock samples (+1.9‰ to +4.4). It was also found that the SO4 concentrations and acidity levels were not only dependent on δ34SSO4 values and existence of pyrite but also on the presence of carbonate minerals in the aquifer matrix. Based on the results from this study, a classification scheme has been developed for identification of waters impacted by acid rock drainage that also encompasses numerous concomitant geochemical processes that often occur in aqueous systems. The classification uses five proxies: SO4, SO4/Cl, SI of calcite, δ34SSO4 and δ18OSO4 to improve assessment of the contribution that oxidation of sulphide minerals has to overall sulphate ion concentrations, regardless of acidity

  4. Drainage basin security of hazardous chemical fluxe in the Yodo River basin. (United States)

    Matsui, S


    The Yodo River basin consists of three major tributary basins (and other small river basins) namely Uji, Katsura and Kizu, which overlap respectively Shiga, Kvoto and Nara prefectures' administrative areas. Lake Biwa, the largest lake in Japan, drains water through the Uji river. The water quality of the lake, in terms of BOD, continuously improved over the last decade. However, the quality in terms of COD did not show any improvement in spite of a large amount of infrastructure finance being introduced. Eutrophication of the lake still continues, showing no improvement in the nitrogen concentration level. Non-point as well as point source control is not strong enough. There is a gap between BOD and COD evaluations of the lake water quality. Hazardous chemical fluxes are estimated based upon PRTR reports of Japan (2001). PCBs are still discharged into the lake, although the report of Shiga Prefecture showed zero discharge. Dace fish monitoring clearly showed that PCB contamination of the fish had not changed since the 1980s in spite of a ban on use and production of PCBs in the 1970s. There is still leakage of PCBs into the lake. The major exposure of dioxins to Japanese is fish rather than meat and eggs. The risk of water contamination must take into consideration not only drinking water safety but also ecological magnification of food chains in water. The ecological health aspect of hazardous chemicals is also important, such as organotins with imposex of sea snails. Finally, public participation in hazardous chemical management is very important using the method of risk communication based upon the annual report of PRTR in Japan.

  5. Environmental status of the Lake Michigan region. Volume 16. Amphibians and reptiles of the Lake Michigan drainage basin

    Energy Technology Data Exchange (ETDEWEB)

    Pentecost, E.D.; Vogt, R.C.


    The focus of this report is on regional distribution of the herpetofauna of the Lake Michigan Drainage Basin. The introduction includes a brief discussion of plant communities and their associated herpetofauna, and the importance of hibernacula and migration routes. Some aspects of the status, distribution, habitat, and life history of the amphibians and reptiles of the Basin are described in an annotated checklist. Special attention is given to uncommon and endangered species. Species range is shown on distribution maps.

  6. Evolution of the Lake Victoria basin in the context of coeval rift initiation in East Africa: a 3D numerical model approach (United States)

    Wichura, Henry; Quinteros, Javier; Melnick, Daniel; Brune, Sascha; Schwanghart, Wolfgang; Strecker, Manfred R.


    Over the last four years sedimentologic and thermochronologic studies in the western and eastern branches of the Cenozoic East African Rift System (EARS) have supported the notion of a broadly contemporaneous onset of normal faulting and rift-basin formation in both segments. These studies support previous interpretations based on geophysical investigations from which an onset of rifting during the Paleogene had been postulated. In light of these studies we explore the evolution of the Lake Victoria basin, a shallow, unfaulted sedimentary basin centered between both branches of the EARS and located in the interior of the East African Plateau (EAP). We quantify the fluvial catchment evolution of the Lake Victoria basin and assess the topographic response of African crust to the onset of rifting in both branches. Furthermore, we evaluate and localize the nature of strain and flexural rift-flank uplift in both branches. We use a 3D numerical forward model that includes nonlinear temperature- and stress-dependent elasto-visco-plastic rheology. The model is able to reproduce the flexural response of variably thick lithosphere to rift-related deformation processes such as lithospheric thinning and asthenospheric upwelling. The model domain covers the entire EAP and integrates extensional processes in a heterogeneous, yet cold and thick cratonic block (Archean Tanzania craton), which is surrounded by mechanically weaker Proterozoic mobile belts, which are characterized by thinner lithosphere ("thin spots"). The lower limits of the craton (170 km) and the mobile belts (120 km) are simulated by different depths of the 1300 °C lithosphere-asthenosphere boundary. We assume a constant extension rate of 4 mm/a throughout the entire simulation of 30 Ma and neglect the effect of dynamic topography and magmatism. Even though the model setup is very simple and the resolution is not high enough to calculate realistic rift-flank uplift, it intriguingly reveals important topographic

  7. Curonian Lagoon drainage basin modelling and assessment of climate change impact

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    Natalja Čerkasova


    Full Text Available The Curonian Lagoon, which is the largest European coastal lagoon with a surface area of 1578 km2 and a drainage area of 100,458 km2, is facing a severe eutrophication problem. With its increasing water management difficulties, the need for a sophisticated hydrological model of the Curonian Lagoon's drainage area arose, in order to assess possible changes resulting from local and global processes. In this study, we developed and calibrated a sophisticated hydrological model with the required accuracy, as an initial step for the future development of a modelling framework that aims to correctly predict the movement of pesticides, sediments or nutrients, and to evaluate water-management practices. The Soil and Water Assessment Tool was used to implement a model of the study area and to assess the impact of climate-change scenarios on the run-off of the Nemunas River and the Minija River, which are located in the Curonian Lagoons drainage basin. The models calibration and validation were performed using monthly streamflow data, and evaluated using the coefficient of determination (R2 and the Nash-Sutcliffe model efficiency coefficient (NSE. The calculated values of the R2 and NSE for the Nemunas and Minija Rivers stations were 0.81 and 0.79 for the calibration, and 0.679 and 0.602 for the validation period. Two potential climate-change scenarios were developed within the general patterns of near-term climate projections, as defined by the Intergovernmental Panel on Climate Change Fifth Assessment Report: both pessimistic (substantial changes in precipitation and temperature and optimistic (insubstantial changes in precipitation and temperature. Both simulations produce similar general patterns in river-discharge change: a strong increase (up to 22% in the winter months, especially in February, a decrease during the spring (up to 10% and summer (up to 18%, and a slight increase during the autumn (up to 10%.

  8. Automated reconstruction of drainage basins and water discharge to the sea through glacial cycles (United States)

    Wickert, Andrew


    Over glacial cycles, ice masses and their geophysical impacts on surface topography dramatically changed drainage patterns and river discharges. These changes impacted meltwater discharge to the ocean, geomorphology, and climate. As the river systems'the threads that tied the ice sheets to the sea'were stretched, severed, and rearranged during deglaciation, they also shrank and swelled with the pulse of meltwater inputs and proglacial lake dynamics. Here I present a general method to compute past river flow paths, drainage basin geometries, and river discharges. I automate these calculations within GRASS GIS to take advantage of rapid solution techniques for drainage networks in an open-source and compute-cluster-ready environment. I combine modern topography and bathymetry with ice sheet reconstructions from the last glacial cycle and a global glacial isostatic adjustment model to build digital elevation models of the past Earth surface. I then sum ice sheet mass balance with computed precipitation and evapotranspiration from a paleoclimate general circulation model to produce grids of water input. I combine these topographic and hydrologic inputs to compute past river networks and discharges through time. These paleodrainage reconstructions connect ice sheets, sea level, and climate models to fluvial systems, which in turn generate measurable terrace and sedimentary records as they carry physical, compositional, and isotopic signatures of ice sheet melt and landscape change through their channels and to the sea. Therefore, this work provides a self-consistent paleogeographic framework within which models and geologic records may be quantitatively compared to build new insights into past glacial systems.

  9. Holistic view to integrated climate change assessment and extreme weather adaptation in the Lake Victoria Basin East Africa (United States)

    Mutua, F.; Koike, T.


    Extreme weather events have been the leading cause of disasters and damage all over the world.The primary ingredient to these disasters especially floods is rainfall which over the years, despite advances in modeling, computing power and use of new data and technologies, has proven to be difficult to predict. Also, recent climate projections showed a pattern consistent with increase in the intensity and frequency of extreme events in the East African region.We propose a holistic integrated approach to climate change assessment and extreme event adaptation through coupling of analysis techniques, tools and data. The Lake Victoria Basin (LVB) in East Africa supports over three million livelihoods and is a valuable resource to five East African countries as a source of water and means of transport. However, with a Mesoscale weather regime driven by land and lake dynamics,extreme Mesoscale events have been prevalent and the region has been on the receiving end during anomalously wet years in the region. This has resulted in loss of lives, displacements, and food insecurity. In the LVB, the effects of climate change are increasingly being recognized as a significant contributor to poverty, by its linkage to agriculture, food security and water resources. Of particular importance are the likely impacts of climate change in frequency and intensity of extreme events. To tackle this aspect, this study adopted an integrated regional, mesoscale and basin scale approach to climate change assessment. We investigated the projected changes in mean climate over East Africa, diagnosed the signals of climate change in the atmosphere, and transferred this understanding to mesoscale and basin scale. Changes in rainfall were analyzed and similar to the IPCC AR4 report; the selected three General Circulation Models (GCMs) project a wetter East Africa with intermittent dry periods in June-August. Extreme events in the region are projected to increase; with the number of wet days

  10. Morphotectonic control of the Białka drainage basin (Central Carpathians: Insights from DEM and morphometric analysis.

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    Wołosiewicz Bartosz


    Full Text Available The Białka river valley is directly related to a deep NNW-SSE oriented fault zone. According to the results of previous morphometric analyses, the Białka drainage basin is one of the most tectonically active zones in the Central Carpathians. It is also located within an area of high seismic activity.

  11. Sensitivity of drainage morphometry based hydrological response (GIUH) of a river basin to the spatial resolution of DEM data (United States)

    Sahoo, Ramendra; Jain, Vikrant


    Drainage network pattern and its associated morphometric ratios are some of the important plan form attributes of a drainage basin. Extraction of these attributes for any basin is usually done by spatial analysis of the elevation data of that basin. These planform attributes are further used as input data for studying numerous process-response interactions inside the physical premise of the basin. One of the important uses of the morphometric ratios is its usage in the derivation of hydrologic response of a basin using GIUH concept. Hence, accuracy of the basin hydrological response to any storm event depends upon the accuracy with which, the morphometric ratios can be estimated. This in turn, is affected by the spatial resolution of the source data, i.e. the digital elevation model (DEM). We have estimated the sensitivity of the morphometric ratios and the GIUH derived hydrograph parameters, to the resolution of source data using a 30 meter and a 90 meter DEM. The analysis has been carried out for 50 drainage basins in a mountainous catchment. A simple and comprehensive algorithm has been developed for estimation of the morphometric indices from a stream network. We have calculated all the morphometric parameters and the hydrograph parameters for each of these basins extracted from two different DEMs, with different spatial resolutions. Paired t-test and Sign test were used for the comparison. Our results didn't show any statistically significant difference among any of the parameters calculated from the two source data. Along with the comparative study, a first-hand empirical analysis about the frequency distribution of the morphometric and hydrologic response parameters has also been communicated. Further, a comparison with other hydrological models suggests that plan form morphometry based GIUH model is more consistent with resolution variability in comparison to topographic based hydrological model.

  12. Lake Victoria basin

    African Journals Online (AJOL)

    measured using a portable echo sounder prior to collecting samples. The net was lowered close to the bottom and then slowly hauled to allow the water to be ... counting chamber and examined under the microscope at x 40 magnification. Taxonomic identification was done using. identification keys as adopted by Ruttner-.

  13. Multivariate indications between environment and ground water recharge in a sedimentary drainage basin in northwestern China (United States)

    Zhu, Bingqi; Wang, Xunming; Rioual, Patrick


    A paucity of studies on the interaction between environment and ground water recharge severely restricts the ability of people to assess future water resources under changing environment. In this study, an effort to explore the relationship between the arid environment and ground water recharge was carried out using multivariate statistical techniques in a sedimentary drainage basin (the Jungar) in northwestern China. Hierarchical cluster analysis (HCA) and principal components analysis (PCA) were performed based on hydrogeochemical data to assess the ground water recharge and its governing factors. Observation of the HCA and PCA analytical results revealed a division of seven clusters (C1 to C7) and three principal components (PC1 to PC3), which explained 59.6%, 16.6% and 10.9% of the variance, respectively, and thus, accounted for the majority of the total variance in the original dataset. Based on these Q-mode HCA clusters and R-mode PAC scores, dominant environmental processes influencing recharge regimes were identified, i.e., geogenic, geomorphoclimatic, and anthropogenic, which separated the recharge regimes into four zones (Zone I to Zone IV). Zones I and II (C4 + C1) were associated to "elevated hydroclimate degree" coupled to "low salinity". Zone III (C2 + C3) was associated to "moderately elevated salinity" and evidently "elevated contamination" but coupled to "low hydroclimate degree". Zone IV (C5 + C6 + C7) was associated mainly to "elevated salinity" coupled to "low or inverse hydroclimate degree". It revealed that the geogenic processes are more significant (60%) than the geomorphoclimatic (17%) and anthropogenic (11%) processes. As a result, the overall recharge process is rather heterogeneous and is strongly environment dominated in the Jungar drainage system. Compared with other watersheds in arid environment, a distinctive feature of the Jungar waters is that they are affected by a combination of natural and non-natural events, rather than

  14. Sensitivity of superconducting gravimeters in central Europe on variations in regional river and drainage basins (United States)

    Kroner, C.; Weise, A.


    As underpinned by various studies in the last years, temporal changes of the Earth's gravity field contain a wealth of information on mass redistribution processes in the Earth's system particularly associated with variations in continental water storage. By combining satellite and terrestrial observations with superconducting gravimeters (SG) a maximum of information can be gained due to the different temporal and spatial sampling. Esp. the cluster of superconducting gravimeters in central Europe is well suited for studies related to spatial and temporal changes in continental water storage. Due to the distribution of SG sites different sensitivities of the instruments are to be expected on changes in the various river and drainage basins which could, if sufficiently pronounced, be deployed to pinpoint areas in which main discrepancies between modelled and actual water storage changes occur and would thus allow us to fine-tune hydrological models. Based on the WaterGap Global Hydrological Model (WGHM), this sensitivity of the SG observations is investigated. One compartment of the WGHM is surface water, thus comprising rivers, flooding areas, and major reservoirs. This contribution is given for the total cell of 0.5° × 0.5° and not localized, e.g. in a riverbed, therefore the question arises to which extent localization or non-localization of this compartment affects the estimate if the respective surface waters are in the vicinity of 50 km around the SG stations. It can be shown, however, that the lateral distribution of the surface water masses plays only a negligible role for the central European stations meaning distributed surface water masses are an acceptable simplification when estimating hydrological effects. It emerges that variations in water storage in regions outside central Europe produce comparable effects on gravity at all sites and the impact of basins within central Europe is clearly distinguishable among the SG stations.

  15. Habitat-specific morphological variation among threespine sticklebacks (Gasterosteus aculeatus) within a drainage basin. (United States)

    Webster, Mike M; Atton, Nicola; Hart, Paul J B; Ward, Ashley J W


    Habitat-specific morphological variation, often corresponding to resource specialization, is well documented in freshwater fishes. In this study we used landmark based morphometric analyses to investigate morphological variation among threespine sticklebacks (Gasterosteus aculeatus L.) from four interconnected habitat types within a single lowland drainage basin in eastern England. These included the upper and lower reaches of the river, the estuary, a connected ditch network and a coastal salt marsh. We found significant habitat-specific differences in morphology, with three axes of variation describing differences in orbit diameter, body depth, caudal peduncle shape and pectoral fin positioning as well as variation in relative dorsal and pelvic spine size. Interestingly, the ditch system, an artificial and heavily managed habitat, is populated by sticklebacks with a characteristic morphology, suggesting that human management of habitats can in some circumstances lead to morphological variation among the animals that inhabit them. We discuss the mechanisms that conceivably underlie the observed morphological variation and the further work necessary to identify them. Finally, we consider the implications of habitat-specific body shape variation for the behavioural ecology of this ecologically generalist species.

  16. Study of morphometry to debit drainage basin (DAS) arau Padang city (United States)

    Utama, Lusi; Amrizal, Berd, Isril; Zuherna


    High intensity rain that happened in Padang city cause the happening of floods at DAS Arau. Floods that happened in Padang besides caused high rain intensity, require to be by research about morphometry that is cause parameter the happening of floods. Morphometry drainage basin physical network (DAS) quantitatively related to DAS geomorphology that is related to form of DAS, river network, closeness of stream, ramp, usage of farm, high and gradient steepness of river. Form DAS will influence rain concentration to outlet. Make an index to closeness of stream depict closeness of river stream at one particular DAS. Speed of river stream influenced by storey, level steepness of river. Steepness storey, level is comparison of difference height of river downstream and upstream. Ever greater of steepness of river stream, excelsior speed of river stream that way on the contrary. High to lower speed of river stream influence occurrence of floods, more than anything else if when influenced by debit big. Usage of farm in glove its link to process of infiltration where if geology type which is impermeable, be difficult the happening of infiltration, this matter will enlarge value of run off. Research by descriptive qualitative that is about characteristic of DAS. Method the used is method survey with data collecting, in the form of rainfall data of year 2005 until year 2015 and Image of DEM IFSAR with resolution 5 meter, analyzed use Software ARGIS. Result of research got by DAS reside in at condition of floods gristle.

  17. Observations of Surface Roughness at Several Scales in Jakobshavn Isbrae Drainage Basin, Greenland (United States)

    Mayer, H.; Herzfeld, U. C.


    The ice surface in the region of Jakobshavn Isbrae and its drainage basin exhibits a fascinating wealth and complexity of surface forms, which are the manifestation of glaciologic and environmental morphogenetic processes operating at different scales. The fast-moving Jakobshavns Isbrae stands out in any satellite image by its heavily crevassed surface, with surface provinces that extend kilometers to tens of kilometers and crevasses of 10-100 meters, whereas the ice surface in the surrounding slow-moving ice is characterized by much smaller features such as sastrugi, melt ponds, wind- and ablation ridges and smooth snow, which are equally important in understanding the complexity of a changing environment. The observation of such complexity necessitates different scale-dependent observation methods including field, aerial and satellite data and a definition of surface roughness that allows to capture the spatial complexity of the interface between snow/ice and atmosphere. Analysis methods range from structural geology and continuum mechanics to geostatistical surface characterization and classification. Application to Jakobshavns Isbrae is of particular interest as the ice-stream system has long been considered the prototype of a time-independent system but has lately exhibited dramatic changes.

  18. Concentration changeability of phosphorus, calcium and magnesium in selected partial drainage basins of the River Drwęca

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    Pius Bożena


    Full Text Available The paper presents the results of the research conducted between November 2008 and October 2009. The research included seasonal dynamics of the flow and runoff of phosphorus compounds (TP and P-PO43-, as well as Ca2+ and Mg2+ from 13 partial drainage basins of the River Drwęca. Water levels were registered automatically every day by recorders, and measurements of the flow were conducted once a month. Major differences were found in the water abundance as indicated by specific discharges in individual, partial drainage basins: from 1.87 dm3 s-1 km-2 (Lubianka - a lower part of the River Drwęca drainage basin to 8.22 dm3 s-1 km-2 (Gizela - an upper part of the River Drwęca drainage basin. The studied rivers were characterised by very diverse average content of total phosphorus compounds: from 0.047 mg dm-3 (Iłga to 0.816 mg dm-3 (Sandela; calcium: from 47.18 mg dm-3 (Iłga to 131.65 mg dm-3 (Trynka; and magnesium: from 9.71 mg dm-3 (Wel to 36.76 mg dm-3 (Struga Rychnowska. Analysis of variance carried out on hydrochemical properties of the studied rivers divides the rivers into two separate groups: rivers with much higher content of phosphorus, calcium and magnesium compounds (Struga Rychnowska, Trynka, Ruziec, Lubianka, Kujawka, Sandela and Gizela, and a group of rivers with low content of these compounds (Brynica, Brodniczanka, Skarlanka, Wel, Iłga.

  19. Genetic integrity of European grayling (Thymallus thymallus L. 1758 within the Vienne River drainage basin after five decades of stockings

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    Henri Persat


    Full Text Available European grayling of the upper Vienne River drainage basin represent the westernmost populations inside the natural distribution of the species. Since the 19th century, their extension across this sub-basin has been dramatically reduced by the harnessing of the river network for dams, initially serving mills but then hydroelectric power generation. Since the 1960s, local fishing authorities have attempted to compensate for these declines with stocking programs, but the efficiency of these efforts have never been accurately monitored. We aim to evaluate the genetic imprints of these stocking programs and thus provide an indirect measure of the long-term survival of stocked fish. Three target populations were analyzed at both mtDNA (Control Region and nDNA levels (12 µSats, and compared to populations representative of surrounding drainage basins or fish farm facilities. Among 37 "wild" fish sequenced, only three control region haplotypes were identified, all belonging to the highly divergent Loire basin lineage. Two were specific to the Upper Vienne area, and one was observed in some individuals of the most downstream location, but previously described from the upper Allier sub-drainage. Microsatellite analysis of 87 "wild" fish also demonstrated a rather low diversity within each population (but typical for the Loire drainage with all Upper Vienne individuals belonging to a single diagnosable unit. This genetic cluster was clearly distinct from all other samples including hatchery strains, which strongly supports its native origin. The only piece of evidence of a possible stocking contribution was the occurrence of the Allier haplotype, but it cannot be excluded that this haplotype was also native to this reach of river. The total lack of genetic impact of five decades of stocking deeply questions the efficacy of this management approach, at least in a regional context.

  20. Natural Landscapes and Optimal Resource Use at the Rio Grande Drainage Basin, Oaxaca, Mexico

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    Marco Antonio Pablo Pablo


    Full Text Available Environmental conservation depends largely on the appropriate management and rational use of natural resources. The assessment of natural landscapes and their suitability for human occupation is key to ensure optimal resource use. The criteria for establishing land-use potentials vary according to the type of activity concerned. For example, in determining the most suitable areas for growing grapes in Cuyo, Argentina, Valpreda (2005 focused on topography, soil quality and water availability, whereas in their study on the oil-producing region of northern Chiapas, Mexico, Bollo et al. (2010 applied markedly different criteria. Soil components and their variability were key to the multi-purpose study of Ovalles and Núñez (1994, while morphometric criteria have been used by Bocco et al. (2010 on farming; for cattle raising, Travieso-Bello et al. (2013 added soil quality and moisture, similar to Rodríguez-Gallego, et al. (2012. In the state of Oaxaca, scientific studies on the feasibility of human activity in different natural landscapes are yet to be undertaken. This study assesses the natural landscapes and resources of the Río Grande drainage basin aimed at establishing optimal locations for agriculture, livestock farming, forestry, wildlife conservation and their combinations. Following the FAO studies (1976, 1993, geomorphological and morphoclimatic systems have been considered as landscape units for analysis. The methodology was adapted from the following studies: The Revised Universal Soil Loss Equation (Ouyang, 2002; an estimate of soil pH based on Landsat imagery (López-Granados et al., 2005; a calculation of potential livestock carrying capacity (LCC (Semarnat, 2003; Vergara and Ortiz-Espinoza, 2010; and a land use and vegetation cover analysis for forestry  suitability and the potential distribution of two cat species (Lynx rufus and Panthera onca (Chávez y Ceballos, 2006; Medellín-Legorreta and Bárcenas, 2009; Semarnat 2010

  1. Geochemical Evolution of Groundwater in the Medicine Lodge Creek Drainage Basin with Implications for the Eastern Snake River Plain Aquifer, Eastern Idaho (United States)

    Ginsbach, M. L.; Rattray, G. W.; McCurry, M. O.; Welhan, J. A.


    The eastern Snake River Plain aquifer (ESRPA) is an unconfined, continuous aquifer located in a northeast-trending structural basin filled with basaltic lava flows and sedimentary interbeds in eastern Idaho. The ESPRA is not an inert transport system, as it acts as both a sink and source for solutes found in the water. More than 90% of the water recharged naturally to the ESRPA is from the surrounding mountain drainage basins. Consequently, in order to understand the natural geochemistry of water within the ESRPA, the chemistry of the groundwater from the mountain drainage basins must be characterized and the processes that control the chemistry need to be understood. The U.S. Geological Survey, in cooperation with the U.S. Department of Energy and Idaho State University, has been studying these mountain drainage basins to help understand the movement of waste solutes in the ESRPA at the Idaho National Laboratory (INL) in eastern Idaho. This study focuses on the Medicine Lodge Creek drainage basin, which originates in the Beaverhead Mountains, extends onto the eastern Snake River Plain, and contributes recharge to the ESRPA beneath the INL as underflow along the northeastern INL boundary. Water and rock samples taken from the Medicine Lodge Creek drainage basin were analyzed to better understand water/rock interactions occurring in this system and to define the groundwater geochemistry of this drainage basin. Water samples were collected at 10 locations in the drainage basin during June 2012: 6 groundwater wells used for agricultural irrigation or domestic use and 4 springs. These water samples were analyzed for major ions, nutrients, trace metals, isotopes, and dissolved gasses. Samples of rock representative of the basalt, rhyolite, and sediments that occur within the drainage basin also were collected. These samples were analyzed using x-ray diffraction and petrographic study to determine the mineralogical constituents of the rock and the presence and

  2. Hydrologic assessment of three drainage basins in the Pinelands of southern New Jersey, 2004-06 (United States)

    Walker, Richard L.; Nicholson, Robert S.; Storck, Donald A.


    The New Jersey Pinelands is an ecologically diverse area in the southern New Jersey Coastal Plain, most of which overlies the Kirkwood-Cohansey aquifer system. The demand for groundwater from this aquifer system is increasing as local development increases. Because any increase in groundwater withdrawals has the potential to affect streamflows and wetland water levels, and ultimately threaten the ecological health and diversity of the Pinelands ecosystem, the U.S. Geological Survey, in cooperation with the New Jersey Pinelands Commission, began a multi-phase hydrologic investigation in 2004 to characterize the hydrologic system supporting the aquatic and wetland communities of the New Jersey Pinelands area (Pinelands). The current investigation of the hydrology of three representative drainage basins in the Pinelands (Albertson Brook, McDonalds Branch, and Morses Mill Stream basins) included a compilation of existing data; collection of water-level and streamflow data; mapping of the water-table altitude and depth to the water table; and analyses of water-level and streamflow variability, subsurface gradients and flow patterns, and water budgets. During 2004-06, a hydrologic database of existing and new data from wells and stream sites was compiled. Methods of data collection and analysis were defined, and data networks consisting of 471 wells and 106 surface-water sites were established. Hydrographs from 26 water-level-monitoring wells and four streamflow-gaging stations were analyzed to show the response of water levels and streamflow to precipitation and recharge with respect to the locations of these wells and streams within each basin. Water-level hydrographs show varying hydraulic gradients and flow potentials, and indicate that responses to recharge events vary with well depth and proximity to recharge and discharge areas. Results of the investigation provide a detailed characterization of hydrologic conditions, processes, and relations among the components



    G. S. Mohamed; S. Srinivasan; R. Pandian; R. J. Gummidipoondi; R. V. Venkatchalam; S. Swaminathan .S


    The Topographic maps and Aerial Photographs are used for morphometric analysis of drainage basins and mapping contours with drainage. The stereo pairs of 2.5 m resolution Cartosat 1, Indian satellite 2 and merged data with 5.5 m resolution P6 Resourcesat 1 LISS 4 Indian satellite of 2001 is used to map, rills, gullies, and streams of first order to evaluate part of drainage basin of Cooum and Poondi Reservoir in Thiruvallur taluk of Tamil Nadu state. The Geo Eye latest 2011data is also used w...

  4. A study on the dynamic interaction of the atmospheric and hydrologic environment in the drainage basin of Sperchios River, Greece (United States)

    Nomikou, Vera-Margarita; Varlas, George; Theofanidi, Sofia; Karymbalis, Efthymios; Papadopoulos, Anastasios; Katsafados, Petros


    The interaction between the atmosphere and inland waters affects the water cycle of the planet and trigger mechanisms that change the water budget, the climate and the land cover. In this study, a fully coupled atmospheric-hydrologic modeling system, WRF-Hydro, is used to study the interaction between the atmosphere and the hydrologic environment as a unified system. The test bed was the drainage basin of the Sperchios River, in which there is a dense network of monitoring. The system was configured on a very fine horizontal resolution using multiple nests and utilizing GIS platform to accurately build the drainage basin of the river. Its hydrological component was also calibrated using runoff measurements along Sperchios River. Two simulations based on the offline and the two-way coupled modes of the system were performed in a case study of a flash flood event. The two-way fully coupled mode of the modeling system was able to resolve the momentum and energy fluxes from the soil surface towards the atmosphere as well as the induced changes in the evapotranspiration, the precipitation, the air temperature and humidity. The thermodynamic condition of the drainage basin modified the characteristics of atmospheric boundary layer changing the stability conditions, the condensation level and the wind profile in the local atmospheric environment. The outputs from both simulations were evaluated using measurements of precipitation and runoff at various places in the basin. Preliminary results indicate slight improvement on the spatiotemporal distribution of the precipitation and the runoff simulated by the two-way fully coupled mode of the system.

  5. Subsurface recharge to the Tesuque aquifer system from selected drainage basins along the western side of the Sangre de Cristo Mountains near Santa Fe, New Mexico (United States)

    Wasiolek, Maryann


    Water budgets developed for basins of five streams draining the western side of the Sangre de Cristo Mountains in northern New Mexico indicate that subsurface inflow along the mountain front is recharging the Tesuque aquifer system of the Espanola Basin. Approximately 14,700 acre-feet of water per year, or 12.7 percent of average annual precipitation over the mountains, is calculated to leave the mountain block and enter the basin as subsurface recharge from the drainage basins of the Rio Nambe, Rio en Medio, Tesuque Creek, Little Tesuque Creek, and Santa Fe River. About 5,520 acre- feet per year, or about 12 percent of average annual precipitation, is calculated to enter from the Rio Nambe drainage basin; about 1,710 acre- feet per year, or about 15 percent of average annual precipitation, is calculated to enter from the Rio en Medio drainage basin; about 1,530 acre- feet, or about 10 percent of average annual precipi- tation, is calculated to enter from the Tesuque Creek drainage basin; about 1,790 acre-feet, or about 19 percent of average annual precipitation, is calculated to enter from the Little Tesuque Creek drainage basin; and about 4,170 acre-feet per year, or about 12 percent average annual precipitation, is calculated to enter from the Santa Fe River drainage basin. Calculated subsurface recharge values were used to define maximum fluxes permitted along the specified-flux boundary defining the mountain front of the Sangre De Cristo Mountains in a numerical computer model of the Tesuque aquifer system near Santa Fe, New Mexico.

  6. Stream-channel and watershed delineations and basin-characteristic measurements using lidar elevation data for small drainage basins within the Des Moines Lobe landform region in Iowa (United States)

    Eash, David A.; Barnes, Kimberlee K.; O'Shea, Padraic S.; Gelder, Brian K.


    Basin-characteristic measurements related to stream length, stream slope, stream density, and stream order have been identified as significant variables for estimation of flood, flow-duration, and low-flow discharges in Iowa. The placement of channel initiation points, however, has always been a matter of individual interpretation, leading to differences in stream definitions between analysts.This study investigated five different methods to define stream initiation using 3-meter light detection and ranging (lidar) digital elevation models (DEMs) data for 17 streamgages with drainage areas less than 50 square miles within the Des Moines Lobe landform region in north-central Iowa. Each DEM was hydrologically enforced and the five stream initiation methods were used to define channel initiation points and the downstream flow paths. The five different methods to define stream initiation were tested side-by-side for three watershed delineations: (1) the total drainage-area delineation, (2) an effective drainage-area delineation of basins based on a 2-percent annual exceedance probability (AEP) 12-hour rainfall, and (3) an effective drainage-area delineation based on a 20-percent AEP 12-hour rainfall.Generalized least squares regression analysis was used to develop a set of equations for sites in the Des Moines Lobe landform region for estimating discharges for ungaged stream sites with 50-, 20-, 10-, 4-, 2-, 1-, 0.5-, and 0.2-percent AEPs. A total of 17 streamgages were included in the development of the regression equations. In addition, geographic information system software was used to measure 58 selected basin-characteristics for each streamgage.Results of the regression analyses of the 15 lidar datasets indicate that the datasets that produce regional regression equations (RREs) with the best overall predictive accuracy are the National Hydrographic Dataset, Iowa Department of Natural Resources, and profile curvature of 0.5 stream initiation methods combined with

  7. Use of real-time monitoring to predict concentrations of select constituents in the Menomonee River drainage basin, Southeast Wisconsin, 2008-9 (United States)

    Baldwin, Austin K.; Graczyk, David J.; Robertson, Dale M.; Saad, David A.; Magruder, Christopher


    The Menomonee River drainage basin in southeast Wisconsin is undergoing changes that may affect water quality. Several rehabilitation and flood-management projects are underway, including removal of concrete channels and the construction of floodwater retention basins. The city of Waukesha may begin discharging treated wastewater into Underwood Creek, thus approximately doubling the current base-flow discharge. In addition, the headwater basins, historically dominated by agriculture and natural areas, are becoming increasingly urbanized.

  8. Geochemistry of groundwater in the Beaver and Camas Creek drainage basins, eastern Idaho (United States)

    Rattray, Gordon W.; Ginsbach, Michael L.


    The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Energy, is studying the fate and transport of waste solutes in the eastern Snake River Plain (ESRP) aquifer at the Idaho National Laboratory (INL) in eastern Idaho. This effort requires an understanding of the natural and anthropogenic geochemistry of groundwater at the INL and of the important physical and chemical processes controlling the geochemistry. In this study, the USGS applied geochemical modeling to investigate the geochemistry of groundwater in the Beaver and Camas Creek drainage basins, which provide groundwater recharge to the ESRP aquifer underlying the northeastern part of the INL. Data used in this study include petrology and mineralogy from 2 sediment and 3 rock samples, and water-quality analyses from 4 surface-water and 18 groundwater samples. The mineralogy of the sediment and rock samples was analyzed with X-ray diffraction, and the mineralogy and petrology of the rock samples were examined in thin sections. The water samples were analyzed for field parameters, major ions, silica, nutrients, dissolved organic carbon, trace elements, tritium, and the stable isotope ratios of hydrogen, oxygen, carbon, sulfur, and nitrogen. Groundwater geochemistry was influenced by reactions with rocks of the geologic terranes—carbonate rocks, rhyolite, basalt, evaporite deposits, and sediment comprised of all of these rocks. Agricultural practices near and south of Dubois and application of road anti-icing liquids on U.S. Interstate Highway 15 were likely sources of nitrate, chloride, calcium, and magnesium to groundwater. Groundwater geochemistry was successfully modeled in the alluvial aquifer in Camas Meadows and the ESRP fractured basalt aquifer using the geochemical modeling code PHREEQC. The primary geochemical processes appear to be precipitation or dissolution of calcite and dissolution of silicate minerals. Dissolution of evaporite minerals, associated with Pleistocene Lake

  9. Geographical and biological analysis of the water quality of Moravica spring in the Sokobanjska Moravica drainage basin, Serbia

    Directory of Open Access Journals (Sweden)

    Stanković S.


    Full Text Available In this work we performed a geographical analysis of the Moravica spring locality in the Sokobanjska Moravica drainage basin in Serbia, as well as an analysis of the physical, chemical, and biological parameters of the water during a one-year period. The basic sanitary characteristics and physical, chemical, and biological parameters, necessary for understanding locality conditions, were studied, and the saprobity index, class of quality, O/H index, degree of saprobity, degree of trophicity, and category based on the phosphatase activity index (PAI were determined. Our results point to the need for continual monitoring of the water quality in the spring locality.

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

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


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

  11. Contemporary suspended sediment dynamics within two partly glacierized mountain drainage basins in western Norway (Erdalen and Bødalen, inner Nordfjord) (United States)

    Beylich, Achim A.; Laute, Katja; Storms, Joep E. A.


    This paper focuses on environmental controls, spatiotemporal variability and rates of contemporary fluvial suspended sediment transport in the neighboring, partly glacierized and steep Erdalen (79.5 km2) and Bødalen (60.1 km2) drainage basins in the fjord landscape of the inner Nordfjord in western Norway. Field work, including extended samplings and measurements, was conducted since 2004 in Erdalen and since 2008 in Bødalen. The distinct intra- and inter-annual temporal variability of suspended sediment transport found is mostly controlled by meteorological events, with most suspended sediment transport occurring during pluvial events in autumn (September-November), followed by mostly thermally determined glacier melt in summer (July-August), and by mostly thermally determined snowmelt in spring (April-June). Extreme rainfall events (> 70 mm d- 1) in autumn can trigger significant debris-flow activity that can cause significant transfers of suspended sediments from ice-free surface areas with sedimentary covers into main stream channels and is particularly important for fluvial suspended sediment transport. In years with occurring relevant debris-flow activity the total annual drainage-basin wide suspended sediment yields are strongly determined by these single extreme events. The proportion of glacier coverage, followed by steepness of slopes, and degree of vegetation cover in ice-free surface areas with sedimentary covers are the main controls for the detected spatial variability of suspended sediment yields. The contemporary sediment supply from glacierized surface areas and the Jostedalsbreen ice cap through different defined outlet glaciers shows a high spatial variability. The fact that the mean annual suspended sediment yield of Bødalen is with 31.3 t km- 2 yr- 1 almost twice as high as the mean annual suspended sediment yield of Erdalen (16.4 t km- 2 yr- 1) is to a large extent explained by the higher proportion of glacier coverage in Bødalen (38% of

  12. Range extension of Moenkhausia oligolepis (Günther,1864 to the Pindaré river drainage, of Mearim river basin, and Itapecuru river basin of northeastern Brazil (Characiformes: Characidae

    Directory of Open Access Journals (Sweden)

    Erick Cristofore Guimarães


    Full Text Available The present study reports range extansion of Moenkhausia oligolepis to the Pindaré river drainage, of the Mearim river basin, and Itapecuru river basin, Maranhão state, northeastern Brazil. This species was previously known only from Venezuela, Guianas, and the Amazon River basins. In addition, we present some meristic and morphometric data of the specimens herein examined and discuss on its diagnostic characters.

  13. Wetland vegetation and nutrient retention in Nakivubo and Kirinya wetlands in the Lake Victoria basin of Uganda (United States)

    Mugisha, P.; Kansiime, F.; Mucunguzi, P.; Kateyo, E.

    Wetlands form an important part of the catchment area of the African Great Lakes and protect water resources therein. One of the most important functions is the retention of nutrients from the inflowing water from the catchment, by wetland plants which store them in their phytomass. An assessment of the capacity in storing nutrients by dominant plants ( Cyeprus papyrus, Miscanthus violaceus, Phragmites mauritianus and Colocasia C. esculenta), of Nakivubo and Kirinya wetlands at the shores of Lake Victoria in Uganda, was studied through the determination of phytomass production and nutrient concentration in the plant parts at different stages of growth. The above ground phytomass production increased rapidly during the exponential growth for C. papyrus and P. mauritianus. In all the dominant plants, nitrogen concentration was highest in juvenile plants and decreased with increasing age. The most pronounced nitrogen level occurred in the young umbels of C. papyrus during the first month of growth with total nitrogen content of 1.95% DW which dropped to 0.62% DW after the fifth month in Nakivubo wetland. Corms (tubers) of yams had the highest nitrogen content in Kirinya and Nakivubo wetlands exhibiting respective values of 4.8% DW and 3.7% DW. There is a close relationship between nutrient content and increase in phytomass. In Nakivubo and Kirinya wetlands, the rapid increase in phytomass during the third and fourth month corresponded with high nutrient levels. Since plants store significant amounts of nitrogen during their growth, periodic harvesting of above ground plant parts can remove significant amounts of nutrients (during the first five months of growth) from the wastewater flowing into the two wetlands. Wetland plant species with high phytomass productivity and well developed root systems and ability to withstand flooding are the best in nutrient removal.

  14. Estimation of design floods in ungauged catchments using a regional index flood method. A case study of Lake Victoria Basin in Kenya (United States)

    Nobert, Joel; Mugo, Margaret; Gadain, Hussein

    Reliable estimation of flood magnitudes corresponding to required return periods, vital for structural design purposes, is impacted by lack of hydrological data in the study area of Lake Victoria Basin in Kenya. Use of regional information, derived from data at gauged sites and regionalized for use at any location within a homogenous region, would improve the reliability of the design flood estimation. Therefore, the regional index flood method has been applied. Based on data from 14 gauged sites, a delineation of the basin into two homogenous regions was achieved using elevation variation (90-m DEM), spatial annual rainfall pattern and Principal Component Analysis of seasonal rainfall patterns (from 94 rainfall stations). At site annual maximum series were modelled using the Log normal (LN) (3P), Log Logistic Distribution (LLG), Generalized Extreme Value (GEV) and Log Pearson Type 3 (LP3) distributions. The parameters of the distributions were estimated using the method of probability weighted moments. Goodness of fit tests were applied and the GEV was identified as the most appropriate model for each site. Based on the GEV model, flood quantiles were estimated and regional frequency curves derived from the averaged at site growth curves. Using the least squares regression method, relationships were developed between the index flood, which is defined as the Mean Annual Flood (MAF) and catchment characteristics. The relationships indicated area, mean annual rainfall and altitude were the three significant variables that greatly influence the index flood. Thereafter, estimates of flood magnitudes in ungauged catchments within a homogenous region were estimated from the derived equations for index flood and quantiles from the regional curves. These estimates will improve flood risk estimation and to support water management and engineering decisions and actions.

  15. China's first intermediate resolution multi-channel seismic survey in the northern Victoria Land Basin and Terror Rift, Ross Sea, Antarctica (United States)

    Shen, Zhongyan; Gao, Jinyao; Zhang, Tao; Wang, Wei; Ding, Weifeng; Zhang, Sheng


    The West Antarctic Rift System (WARS) represents one of the largest active continental rift systems on Earth and is less well known than other rift systems because it is largely covered by thick ice. The Terror Rift (TR), superimposing on the Victoria Land Basin (VLB) in the western Ross Sea, is identified as the most recent deformational zone of the WARS, thus will provide knowledge of the active deformation process of the WARS. The structure and kinematics of the TR is under debate. Originally, the TR was thought to consist of two parts: the Discovery Graben and the magmatically-intruded Lee Arch. New denser seismic grid in the middle and southern segments of the TR revealed a different structure of the Lee Arch while the northern segment of the TR is not well studied. The glacial history of the VLB/TR region is another attractive issue to the geologists since this area records the behavior information of EAIS and WAIS. In the southern part of the VLB, especially in the McMurdo Sound, the framework of the glacial history is well established after several deep cores which recovery the whole stratigraphic sequences since the onset of the glaciation. However, the glacial history of the northern part of the VLB/TR is less well studied and here we emphasize its importance because the northern part of the VLB/TR is a link between the well-studied southern VLB and the sediment-well-preserved Northern Basin. During the 32nd Chinese National Antarctic Research Expedition, on the board of the RV XueLong, we collected intermediate resolution multi-channel seismic reflection data in the northern VLB/TR. These data will establish new constraints on the timing of deformation, structure and kinematics of the TR, and the history of the EAIS and WAIS.

  16. Projecting the future levels of Lake Victoria (United States)

    Vanderkelen, Inne; van Lipzig, Nicole; Thiery, Wim


    Lake Victoria directly sustains 30 million people living in its basin and 200 000 fishermen operating from its shores. As the one of the two sources of the Nile River, it also supports natural resources that impact the livelihood of over 300 million people living in the Nile basin. The outlet to the Nile is controlled by two hydropower dams. The water balance of Lake Victoria is controlled both by climatic conditions (precipitation and evaporation) and human management (dam outflow). Future climate simulations with a high resolution coupled lake-land-atmosphere model project decreasing mean precipitation and increasing evaporation over Lake Victoria. As these two are important factors in the water balance of Lake Victoria, these projected changes may induce a drop in future levels of Lake Victoria. Moreover, as Lake Victoria is also a relatively shallow lake, lake surface area may decrease as well. Here we present a water balance model for Lake Victoria that provides lake level and extent as output. We first force our model with observational input (new satellite products providing high quality precipitation and evaporation data) and evaluate it using measured lake levels. The skill of the model is subsequently assessed by forcing it with present-day regional climate simulations (CORDEX evaluation simulations). In a third step the future lake levels and surface area changes of Lake Victoria are simulated by forcing the model with CORDEX projections under RCP4.5 and 8.5. Finally, the role of human decisions regarding future dam outflow are investigated.

  17. Drainage areas for selected stream-sampling stations, Missouri River Basin (United States)

    U.S. Geological Survey, Department of the Interior — As part of the U.S. Geological Survey's (USGS) National Water-Quality Assessment Program (NAWQA), an investigation of the Missouri River Basin is being conducted to...

  18. Paleo-drainage basin connectivity predicts evolutionary relationships across three Southeast Asian biodiversity hotspots. (United States)

    de Bruyn, Mark; Rüber, Lukas; Nylinder, Stephan; Stelbrink, Björn; Lovejoy, Nathan R; Lavoué, Sébastien; Tan, Heok Hui; Nugroho, Estu; Wowor, Daisy; Ng, Peter K L; Siti Azizah, M N; Von Rintelen, Thomas; Hall, Robert; Carvalho, Gary R


    Understanding factors driving diversity across biodiversity hotspots is critical for formulating conservation priorities in the face of ongoing and escalating environmental deterioration. While biodiversity hotspots encompass a small fraction of Earth's land surface, more than half the world's plants and two-thirds of terrestrial vertebrate species are endemic to these hotspots. Tropical Southeast (SE) Asia displays extraordinary species richness, encompassing four biodiversity hotspots, though disentangling multiple potential drivers of species richness is confounded by the region's dynamic geological and climatic history. Here, we use multilocus molecular genetic data from dense multispecies sampling of freshwater fishes across three biodiversity hotspots, to test the effect of Quaternary climate change and resulting drainage rearrangements on aquatic faunal diversification. While Cenozoic geological processes have clearly shaped evolutionary history in SE Asian halfbeak fishes, we show that paleo-drainage re-arrangements resulting from Quaternary climate change played a significant role in the spatiotemporal evolution of lowland aquatic taxa, and provide priorities for conservation efforts.

  19. River piracy and drainage basin reorganization led by climate-driven glacier retreat (United States)

    Shugar, Daniel H.; Clague, John J.; Best, James L.; Schoof, Christian; Willis, Michael J.; Copland, Luke; Roe, Gerard H.


    River piracy--the diversion of the headwaters of one stream into another one--can dramatically change the routing of water and sediment, with a profound effect on landscape evolution. Stream piracy has been investigated in glacial environments, but so far it has mainly been studied over Quaternary or longer timescales. Here we document how retreat of Kaskawulsh Glacier--one of Canada's largest glaciers--abruptly and radically altered the regional drainage pattern in spring 2016. We use a combination of hydrological measurements and drone-generated digital elevation models to show that in late May 2016, meltwater from the glacier was re-routed from discharge in a northward direction into the Bering Sea, to southward into the Pacific Ocean. Based on satellite image analysis and a signal-to-noise ratio as a metric of glacier retreat, we conclude that this instance of river piracy was due to post-industrial climate change. Rapid regional drainage reorganizations of this type can have profound downstream impacts on ecosystems, sediment and carbon budgets, and downstream communities that rely on a stable and sustained discharge. We suggest that the planforms of Slims and Kaskawulsh rivers will adjust in response to altered flows, and the future Kaskawulsh watershed will extend into the now-abandoned headwaters of Slims River and eventually capture the Kluane Lake drainage.

  20. Hawaii StreamStats; a web application for defining drainage-basin characteristics and estimating peak-streamflow statistics (United States)

    Rosa, Sarah N.; Oki, Delwyn S.


    Reliable estimates of the magnitude and frequency of floods are necessary for the safe and efficient design of roads, bridges, water-conveyance structures, and flood-control projects and for the management of flood plains and flood-prone areas. StreamStats provides a simple, fast, and reproducible method to define drainage-basin characteristics and estimate the frequency and magnitude of peak discharges in Hawaii?s streams using recently developed regional regression equations. StreamStats allows the user to estimate the magnitude of floods for streams where data from stream-gaging stations do not exist. Existing estimates of the magnitude and frequency of peak discharges in Hawaii can be improved with continued operation of existing stream-gaging stations and installation of additional gaging stations for areas where limited stream-gaging data are available.

  1. Two new species of Melanorivulus (Cyprinodontiformes: Cynolebiidae) from Rio Verde drainage, Upper Rio Paraná basin, Brazil. (United States)

    Volcan, Matheus Vieira; Klotzel, Bruno; Lanés, Luis Esteban Krause


    Two new species of the genus Melanorivulus are herein described from the middle Rio Verde drainage, upper Rio Paraná basin, Mato Grosso do Sul, Brazil. Both new species are members of the Melanorivulus pictus clade, diagnosed by having ventral process of angulo-articular vestigial and flanks intense greenish blue or greenish golden to purplish blue above anal fin base in males. Melanorivulus nigropunctatus, new species, from wetlands of a small drainage tributary of right side of the Rio Verde, differs from all other congeners by possessing black dots over the head and body in both sexes and pectoral fin orange with a dark grey margin in males. Melanorivulus ofaie, new species, is found in a similar environment, but at the opposite margin of the Rio Verde. It is distinguished by males presenting flank greenish blue to light blue, with seven to nine oblique chevron-like red bars, ventral portion of head whitish with dark brown spots, dorsal fin yellow with two to three transverse broad red oblique stripes and distal region red, anal fin light orangish yellow, basal area light blue with short red bars and distal portion with a dark red margin, and caudal fin yellow or orangish yellow with three to four vertical red bars in the dorsal and middle portions, sometimes with a orange distal margin. Both new species are considered endangered due to the loss and degradation of their habitat.

  2. The influence of flow-through saline gravel pit lakes on the hydrologic budget and hydrochemistry of a Mediterranean drainage basin

    NARCIS (Netherlands)

    Mollema, P.N.; Antonellini, Marco; Dinelli, Enrico; Greggio, Nicolas; Stuijfzand, Pieter


    Flow-through brackish gravel pit lakes near the Adriatic Coast of Emilia Romagna (Italy) in the Mediterranean have a large influence on the hydrologic budget of the watershed. Strong evaporation in combination with intense drainage of the low lying basins enhances groundwater inflow into the

  3. Trace Elements in Bed Sediments and Biota from Streams in the Santee River Basin and Coastal Drainages, North and South Carolina, 1995-97 (United States)

    Thomas A. Abrahamsen


    Bed-sediment and tissue samples were collected and analyzed for the presence of trace elements from 25 sites in the Santee River Basin and coastal drainages study area during 1995-97 as part of the U.S. Geological Survey's National Water-Quality Assessment Program, Sediment trace-element priority-pollutant concentrations were compared among streams draining water-...

  4. A study case of Baranca drainage basin flash-floods using the hydrological model of Hec-Ras

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    Aritina HALIUC


    Full Text Available In the last decades, the floods which occurred within Romanian territory stand as proof for the increased frequency of the extreme hydrological hazards which have negative effects on the normal pathway of the human-beings activities. The technological progress among with the increased frequency of floods events are the base for the development of informational programs for the analysis, simulation and flood management. The Baranca brook which drains a considerable part of Zamostea village (Romania was used as a pilot drainage basin for the flash-flood simulation using the Hec-Ras program and the Arcgis extension, HecGeo-Ras. The flash-floods that occurred in the summer of 2010 were used to validate the results of the simulation. Between 28.06.2010 – 29.06.2010, two flash-floods occurred in the Baranca drainage basin with a discharge oscillated between 10m3 and 70m3, a water extent which covered an area of 5.14 km2 and a depth ranging between 0.3-3m. The programs are capable to simulate the water flow and to investigate the floodway encroachments in the study area. The damages evaluated in the field along with the program’s results reveal the fact that more than half of the built-up areas of Zamostea village are established along brooks, within the floodplain area. What is more, after the 2010 floods, the expension of the habitable area was not detained by the water danger, many houses are still built on the floodplain. The programs used, taking an acceptable margin of error, may be integrated into any flood management strategy or in any watershed plan and may provide the necessary support for mitigating the risks associated with floods

  5. Present morphoclimate and morphodynamics in the boreal Homla drainage basin system (Trøndelag, middle Norway) (United States)

    Beylich, Achim A.


    It is generally accepted that ongoing and future climate change will cause major changes in Earth surface systems and environments. From a geomorphological point of view, it is accordingly of increasing importance to obtain a better understanding of the relationships between contemporary geomorphological processes and present-day climatic conditions to come to more reliable assessments of the possible geomorphological effects of climate change. Until recently, the present-day climate has often only been characterized by monthly and annual means or sum values of wind speed, air temperature and precipitation. As most geomorphological surface processes consist of discrete events which are only partly correlated to these meteorological means or sum values, there is an obvious need for an additional approach of statistical analysis of meteorological data. In this study the "morphoclimate" of the Homla drainage basin situated in a boreal environment in Trøndelag in middle Norway is analyzed. "Morphoclimate" according to Ahnert (e.g., 1982) is specially related to geomorphological needs and, in this sense, is defined as the totality of those climatic characteristics of an area that influence the type, frequency, duration and intensity of the exogenic geomorphologic processes in this area. The statistical method primarily used in this context is the magnitude-frequency analysis. Particular emphasis is on (i) the frequencies or recurrence intervals of meteorological events of given magnitudes, and (ii) the frequencies of geomorphologically important thresholds. Aspects of the current wind, temperature and precipitation regimes which control the type, frequency, duration and intensity of the contemporary denudational surface processes as well as the sedimentary budget in the selected study area are presented. Runoff in the boreal Homla drainage basin is occurring year-round and the contemporary morphodynamics are altogether characterized by a clear dominance of chemical


    Directory of Open Access Journals (Sweden)

    Marlo Pereira Lima


    Full Text Available Nowadays it is discussed the necessity of preservation of the hydro resources availablefor consumption. Once the human beings have the consumption of water as somethingessencial for the life, since early they valued water near their houses. This preocupationcontinue, although during the last decade, the progressive destructions of nature waterreservoirs are observated. Among the depredating actions are: polution, contaminated riversand deforestation of ciliary woods near the rivers that become easy and fast the erosiveprocesses.The state of Maranhão, besides is in Northeast, has different physical characteristicsfrom the rest of the region. The drainage basins that are distributed through the Maranhão arecomposed of principal perennial rivers and tributaries that are sometimes perennial andtemporary. In the Munin river basin, the growing urbane evolution results in seriousenvironmental consequences in its way. The stretch studied, in Chapadinha-Maranhão, hassuffered quick erosive process and consequently the silting on the riverbanks.So in this work we intend to identify the principal agents and processes that spoil thefluvial environment provoking the erosion on the banks and the silting of the watercourse.

  7. Constructing a sequence of palaeoDEMs to obtain erosion rates in a drainage basin.N (United States)

    Castelltort, F. Xavier; Carles Balasch, J.; Cirés, Jordi; Colombo, Ferran


    DEMs made in a present-day drainage basin, considering it as a geomorphic unit, represent the end result of a landscape evolution. This process has had to follow a model of erosion. Trying to establish a conceptual erosion model in landscape evolution represents the first difficulty in constructing a sequence of palaeoDEMs. But if one is able to do it, the result will be easier and believable. The next step to do is to make a catalogue of base level types present in the drainage basin. The list has to include elements with determinate position and elevation (x, y, z) from the centre of the basin until hillslopes. A list of base level types may contain fluvial terrace remnants, erosive surfaces, palaeosols, alluvial covers of glacis, alluvial fans, rockfalls, landslides and scree zones. It is very important to know the spatial and temporal relations between the elements of the list, even if they are disconnected by erosion processes. Relative chronologies have to be set for all elements of the catalogue, and as far as possible absolute chronologies. To do it,it is essential to have established first the spatial relations between them, including those elements that are gone. Moreover, it is also essential to have adapted all the elements to the conceptual erosion model proposed. In this step, it has to be kept in mind that erosion rates can be very different in determinate areas within the same geomorphic unit. Erosion processes are focused in specific zones while other areas are maintained in stability. A good technique to construct a palaeoDEM is to start making, by hand, a map of contour lines. At this point, it is valuable to use the elements' catalogue. The use of those elements belonging to the same palaeosurface will result in a map. Several maps can be obtained from a catalogue. Contour maps can be gridded into a 3D surface by means of a specific application and a set of surfaces will be obtained. Algebraic operations can be done with palaeoDEMs obtaining

  8. Spatial organization of process domains in headwater drainage basins of a glaciated foothills region with complex longitudinal profiles (United States)

    McCleary, Richard J.; Hassan, Marwan A.; Miller, Dan; Moore, R. D.


    Lithologic transitions and glaciations create complex longitudinal profiles that control contemporary erosion and deposition processes. In areas with these characteristics, traditional morphometric approaches for predicting process domains, such as area-slope plots, can be augmented by considering other predictors measured from high resolution lidar-derived digital elevation models (DEMs). Ordinal logistic regression was used to model the distribution of hillslope, swale, colluvial channel, and fluvial channel domains, as identified during field surveys. The study area was a glaciated region of the Rocky Mountain foothills with a complex lithostructural setting. Relationships between domains and a suite of geographic information system-derived descriptors were explored. Predictors included profile anomalies measured at the reach and basin scale using a normalized stream length-gradient (SL/k) index. Drainage area was the dominant factor controlling domains. A model with area as the only predictor was 82% accurate. Reach slope relations were not consistent. A model that also included lithology and basin-scale SL/k index variation was 87% accurate. Domain transitions had larger area thresholds in basins with resistant conglomerate versus sandstone or shale formations and where SL/k index was more variable along a profile. In a restricted model of hillslope, swale, and colluvial channel domains, profile curvature measured over 100 m was also related to domain occurrence. A model for regional-scale mapping applications with six additional predictors was 95% accurate. The results showed that ordinal logistic regression can be used to predict and map process domains in regions with complex physiography using descriptors measured from high -resolution DEMs.

  9. The Vigil Network: A means of observing landscape change in drainage basins (United States)

    Osterkamp, W.R.; Emmett, W.W.; Leopold, Luna Bergere


    Long-term monitoring of geomorphic, hydrological, and biological characteristics of landscapes provides an effective means of relating observed change to possible causes of the change. Identification of changes in basin characteristics, especially in arid areas where the response to altered climate or land use is generally rapid and readily apparent, might provide the initial direct indications that factors such as global warming and cultural impacts have affected the environment. The Vigil Network provides an opportunity for earth and life scientists to participate in a systematic monitoring effort to detect landscape changes over time, and to relate such changes to possible causes. The Vigil Network is an ever-increasing group of sites and basins used to monitor landscape features with as much as 50 years of documented geomorphic and related observations.

  10. Metal transport and remobilisation in a basin affected by acid mine drainage

    DEFF Research Database (Denmark)

    Consani, Sirio; Carbone, Cristina; Dinelli, Enrico


    takes place. This precipitate forms a soft blanket that covers the torrent bed and can be observed down to its mouth in the sea. The aim of this work is to evaluate the dispersion of metals in the Gromolo Torrent basin from the abandoned Cu-Fe sulphide mine of Libiola to the Ligurian Sea and to assess...... in the released fraction. Pb was still strongly released as in deionised water experiments. The results show that the interaction of precipitates and seawater can remobilise high concentrations of metals, thus affecting the surrounding environment....

  11. The Victoria Project, Sri Lanka. Hydrological analysis for Victoria Dam

    Energy Technology Data Exchange (ETDEWEB)

    Piper, B.S. [GU Projects (United Kingdom); Sutcliffe, J.V. [Gibb (Sir Alexander) and Partners (United Kingdom); Parks, Y.P. [Institute of Hydrology (United Kingdom)


    The hydrological analyses described in this paper formed an important part of the studies for the Victoria Project of which the Victoria Dam is the major component. The purpose of the hydrological studies was to provide consistent sets of river flow and climate data at the sites of the major components of the project, and to provide flood estimates for sizing the spillway and river diversion works. This paper outlines the approach used in the overall study, and then concentrates on aspects of specific relevance to the Victoria Dam. The main hydrological characteristics of the upper Mahaweli basin are presented as an introduction to the overall water balance; the humid climate made the appraisal of flow records relatively simple. Time series modelling was used to fill gaps in the observed flow records used for reservoir operation studies. The spillway design flood was based on the probable maximum precipitation (PMP) derived by maximizing a historic storm in which rainfall approaching the PMP covered most of the basin. Construction floods of moderate return period were estimated from a dimensionless analysis of regional flood records. The main lessons to be drawn are that water balance methods are of particular value in these humid monsoon conditions, while the ratio of the PMP to the maximum recorded storm is lower than would be the case in more arid regions. (author)

  12. An Open Source approach to automated hydrological analysis of ungauged drainage basins in Serbia using R and SAGA (United States)

    Zlatanovic, Nikola; Milovanovic, Irina; Cotric, Jelena


    Drainage basins are for the most part ungauged or poorly gauged not only in Serbia but in most parts of the world, usually due to insufficient funds, but also the decommission of river gauges in upland catchments to focus on downstream areas which are more populated. Very often, design discharges are needed for these streams or rivers where no streamflow data is available, for various applications. Examples include river training works for flood protection measures or erosion control, design of culverts, water supply facilities, small hydropower plants etc. The estimation of discharges in ungauged basins is most often performed using rainfall-runoff models, whose parameters heavily rely on geomorphometric attributes of the basin (e.g. catchment area, elevation, slopes of channels and hillslopes etc.). The calculation of these, as well as other paramaters, is most often done in GIS (Geographic Information System) software environments. This study deals with the application of freely available and open source software and datasets for automating rainfall-runoff analysis of ungauged basins using methodologies currently in use hydrological practice. The R programming language was used for scripting and automating the hydrological calculations, coupled with SAGA GIS (System for Automated Geoscientivic Analysis) for geocomputing functions and terrain analysis. Datasets used in the analyses include the freely available SRTM (Shuttle Radar Topography Mission) terrain data, CORINE (Coordination of Information on the Environment) Land Cover data, as well as soil maps and rainfall data. The choice of free and open source software and datasets makes the project ideal for academic and research purposes and cross-platform projects. The geomorphometric module was tested on more than 100 catchments throughout Serbia and compared to manually calculated values (using topographic maps). The discharge estimation module was tested on 21 catchments where data were available and compared

  13. Environmental status of the Lake Michigan region. Volume 14. Birds of the Lake Michigan drainage basin

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, G.J.


    This report characterizes the bird life found in 100 counties of the four states peripheral to Lake Michigan. It discusses major habitats (the Lake Michigan shoreline, inland lakes, rivers and streams, marshes, fields and open spaces, and woodlots) and associates specific birds with habitats according to preferences for space and food. It also discusses the special attributes of state parks and lakeshores, refuges and sanctuaries, and other special areas which are attractive to avifauna. Patterns of historical occurrence and abundance, and the influence of pesticides and pollution, disease, and hunting pressure are explored to place present occurrence in a modern perspective. Migration patterns are discussed to explain increases and decreases which occur in nonresident avifauna of the Basin. The distribution and habits of birds that occur regularly in the Basin are described in an annotated list; a more complete list is presented in a table which encapsulates data for rapid and convenient reference. Separate sections deal with extinct, extirpated, and introduced species, and with endangered, threatened, and declining species.

  14. Fracture patterns of the drainage basin of Wadi Dahab in relation to tectonic-landscape evolution of the Gulf of Aqaba - Dead Sea transform fault (United States)

    Shalaby, Ahmed


    Crustal rifting of the Arabian-Nubian Shield and formation of the Afro-Arabian rifts since the Miocene resulted in uplifting and subsequent terrain evolution of Sinai landscapes; including drainage systems and fault scarps. Geomorphic evolution of these landscapes in relation to tectonic evolution of the Afro-Arabian rifts is the prime target of this study. The fracture patterns and landscape evolution of the Wadi Dahab drainage basin (WDDB), in which its landscape is modeled by the tectonic evolution of the Gulf of Aqaba-Dead Sea transform fault, are investigated as a case study of landscape modifications of tectonically-controlled drainage systems. The early developed drainage system of the WDDB was achieved when the Sinai terrain subaerially emerged in post Eocene and initiation of the Afro-Arabian rifts in the Oligo-Miocene. Conjugate shear fractures, parallel to trends of the Afro-Arabian rifts, are synthesized with tensional fracture arrays to adapt some of inland basins, which represent the early destination of the Sinai drainage systems as paleolakes trapping alluvial sediments. Once the Gulf of Aqaba rift basin attains its deeps through sinistral movements on the Gulf of Aqaba-Dead Sea transform fault in the Pleistocene and the consequent rise of the Southern Sinai mountainous peaks, relief potential energy is significantly maintained through time so that it forced the Pleistocene runoffs to flow via drainage systems externally into the Gulf of Aqaba. Hence the older alluvial sediments are (1) carved within the paleolakes by a new generation of drainage systems; followed up through an erosional surface by sandy- to silty-based younger alluvium; and (2) brought on footslopes of fault scarps reviving the early developed scarps and inselbergs. These features argue for crustal uplifting of Sinai landscapes syn-rifting of the Gulf of Aqaba rift basin. Oblique orientation of the Red Sea-Gulf of Suez rift relative to the WNW-trending Precambrian Najd faults; and

  15. Flood frequency analysis for nonstationary annual peak records in an urban drainage basin (United States)

    Villarini, G.; Smith, J.A.; Serinaldi, F.; Bales, J.; Bates, P.D.; Krajewski, W.F.


    Flood frequency analysis in urban watersheds is complicated by nonstationarities of annual peak records associated with land use change and evolving urban stormwater infrastructure. In this study, a framework for flood frequency analysis is developed based on the Generalized Additive Models for Location, Scale and Shape parameters (GAMLSS), a tool for modeling time series under nonstationary conditions. GAMLSS is applied to annual maximum peak discharge records for Little Sugar Creek, a highly urbanized watershed which drains the urban core of Charlotte, North Carolina. It is shown that GAMLSS is able to describe the variability in the mean and variance of the annual maximum peak discharge by modeling the parameters of the selected parametric distribution as a smooth function of time via cubic splines. Flood frequency analyses for Little Sugar Creek (at a drainage area of 110 km2) show that the maximum flow with a 0.01-annual probability (corresponding to 100-year flood peak under stationary conditions) over the 83-year record has ranged from a minimum unit discharge of 2.1 m3 s- 1 km- 2 to a maximum of 5.1 m3 s- 1 km- 2. An alternative characterization can be made by examining the estimated return interval of the peak discharge that would have an annual exceedance probability of 0.01 under the assumption of stationarity (3.2 m3 s- 1 km- 2). Under nonstationary conditions, alternative definitions of return period should be adapted. Under the GAMLSS model, the return interval of an annual peak discharge of 3.2 m3 s- 1 km- 2 ranges from a maximum value of more than 5000 years in 1957 to a minimum value of almost 8 years for the present time (2007). The GAMLSS framework is also used to examine the links between population trends and flood frequency, as well as trends in annual maximum rainfall. These analyses are used to examine evolving flood frequency over future decades. ?? 2009 Elsevier Ltd.


    Directory of Open Access Journals (Sweden)

    Ionut Minea


    Full Text Available ABSTRACT. – Patterns utilized in the simulation of underground water flow and the transportation of pollutants in the Bahlui drainage basin. In the actual context of accelerate economic development, the excessive exploatation of water resources from the underground and the contamination of these with different water pollutants has become a major problem which has enetered the attention of many researchers. For the evaluation of an underground water flow and pollutants transport sistem we have chosen the package of programs MODFLOW which includes a whole series of applications,such as MOC3D, MT3D, MT3DMS, PEST, UCODE, PMPATH, which allow simulations and multiple recalibrations of the capacity of recharging of the aquifers, the flowing of the water towards wells and drillings the transport of a pollutant agent in the underground or the evaluation of the exchange of water between the hidrographic network and aquifers. The sistem targets both the evaluation of the modelation of the underground flowing and the simulation of a punctual polluation of the canvas of groundwater scenery, in the meadow of the river Bahlui, west from Letcani village.

  17. Late Pliocene establishment of exorheic drainage in the northeastern Tibetan Plateau as evidenced by the Wuquan Formation in the Lanzhou Basin (United States)

    Guo, Benhong; Liu, Shanpin; Peng, Tingjiang; Ma, Zhenhua; Feng, Zhantao; Li, Meng; Li, Xiaomiao; Li, Jijun; Song, Chunhui; Zhao, Zhijun; Pan, Baotian; Stockli, Daniel F.; Nie, Junsheng


    The fluvial archives in the upper-reach Yellow River basins provide important information about drainage history of the northeastern Tibetan Plateau (TP) associated with geomorphologic evolution and climate change. However, the Pliocene fluvial strata within this region have not been studied in detail, hence limiting the understanding of the late Cenozoic development of regional fluvial systems. In this paper, we present the results of a study of the geochronology, sedimentology, and provenance of the fluvial sequence of the Wuquan Formation in the Lanzhou Basin in the northeastern TP. Magnetostratigraphic and cosmogenic nuclide burial ages indicate that the Wuquan Formation was deposited during 3.6-2.2 Ma. Furthermore, sedimentary facies, gravel composition, paleocurrent data, and detrital zircon Usbnd Pb age spectra reveal that the fluvial sequence resembles the terraces of the Yellow River in terms of source area, flow direction, and depositional environment. Our results indicate that a paleo-drainage system flowing out of the northeastern TP was established by ca. 3.6 Ma and that the upstream parts of the Yellow River must have developed subsequently from this paleo-drainage system. The late Pliocene drainage system fits well with the dramatic uplift of the northeastern TP, an intensified Asian summer monsoon, and global increase in erosion rates, which may reflect interactions between geomorphic evolution, tectonic deformation, and climate change.

  18. Active deformation of the eastern part of the Anatolian scholle: Implications from river long profiles and drainage basins' analyses (United States)

    Sançar, Taylan


    The complex tectonic setting of the eastern Mediterranean region is mainly made by the kinematic interaction along the boundaries of the Eurasian (Eu), African (Af), Arabian (Ar) plates and smaller Anatolian scholle (An). An is being extruded westward as a result of ongoing post-collisional convergence between the Eu and Ar. Although the main deformation accommodated by the North Anatolian Shear Zone (NASZ) and the East Anatolian Shear Zone (EASZ), which delimit the northern and eastern boundaries of the An, the NW-striking dextral and NE-striking sinistral faults represent a remarkable intra-plate deformation within the An. In contrast to studies that suggest no active deformation along the Malatya-Ovacık Fault Zone (MOFZ) and other strike-slip fault within the An, recent geological, geophysical and geodetic studies suggest the opposite. In this study, I focused on relatively a more complex region of the An that is delimited by the NASZ to the north, the EASZ to the southeast, the MOFZ to the west, and the Nazmiye Fault Zone (NFZ) to the south. In order to examine the recent deformation characteristics of this structurally complex region I studied the geomorphic aspects of rivers longitudinal profiles and drainage basins. First, I extracted drainage systems by using a digital elevation model (DEM) with 10 m ground pixel resolution that is derived from 1:25k scale digital topographic maps of the region. Then, I calculated steepness and concavity indices of the river long profiles, which point out that the current uplift rate of middle part of the region exceeds the rate of the erosion. Despite lithological variations, majority of the channels, which drain the middle part of the region, display a normal range of concavity. The spatial distribution of channel normalized steepness indices show anomalously high values in the middle part of the study region. Moreover, the high SLk values, strong asymmetry and the convex-shaped hypsometric curves indicate a younger

  19. Phase II modification of the Water Availability Tool for Environmental Resources (WATER) for Kentucky: The sinkhole-drainage process, point-and-click basin delineation, and results of karst test-basin simulations (United States)

    Taylor, Charles J.; Williamson, Tanja N.; Newson, Jeremy K.; Ulery, Randy L.; Nelson, Hugh L.; Cinotto, Peter J.


    This report describes Phase II modifications made to the Water Availability Tool for Environmental Resources (WATER), which applies the process-based TOPMODEL approach to simulate or predict stream discharge in surface basins in the Commonwealth of Kentucky. The previous (Phase I) version of WATER did not provide a means of identifying sinkhole catchments or accounting for the effects of karst (internal) drainage in a TOPMODEL-simulated basin. In the Phase II version of WATER, sinkhole catchments are automatically identified and delineated as internally drained subbasins, and a modified TOPMODEL approach (called the sinkhole drainage process, or SDP-TOPMODEL) is applied that calculates mean daily discharges for the basin based on summed area-weighted contributions from sinkhole drain-age (SD) areas and non-karstic topographically drained (TD) areas. Results obtained using the SDP-TOPMODEL approach were evaluated for 12 karst test basins located in each of the major karst terrains in Kentucky. Visual comparison of simulated hydrographs and flow-duration curves, along with statistical measures applied to the simulated discharge data (bias, correlation, root mean square error, and Nash-Sutcliffe efficiency coefficients), indicate that the SDPOPMODEL approach provides acceptably accurate estimates of discharge for most flow conditions and typically provides more accurate simulation of stream discharge in karstic basins compared to the standard TOPMODEL approach. Additional programming modifications made to the Phase II version of WATER included implementation of a point-and-click graphical user interface (GUI), which fully automates the delineation of simulation-basin boundaries and improves the speed of input-data processing. The Phase II version of WATER enables the user to select a pour point anywhere on a stream reach of interest, and the program will automatically delineate all upstream areas that contribute drainage to that point. This capability enables

  20. Using river long profiles and geomorphic indices to evaluate the geomorphological signature of continental scale drainage capture, Duero basin (NW Iberia) (United States)

    Antón, Loreto; De Vicente, Gerardo; Muñoz-Martín, Alfonso; Stokes, Martin


    Well-constrained case studies of transient landscape responses are needed to improve our understanding of erosion processes associated with drainage captures. The Duero basin is an excellent location for such a study because the landscape is currently undergoing pronounced geomorphological changes resulting from the opening of a former closed drainage. The present-day continental interior basin (> 50,000 km2) drains to the Atlantic Ocean via the Duero River, but during the Cenozoic the basin experienced a long endorheic period marked by the formation of evaporites. Currently, the entire continental interior is an area of relative tectonic quiescence, characterised by a relict low-relief upland topography (Meseta). Systematic variations in lithology and a well-constrained tectonic setting throughout the basin and adjacent areas allow for the comparison of channel morphology between the Cenozoic Duero basin and its western fringe. To explore the signal of transient geomorphic response to capture and opening of the former endorheic basin, the main channel and 24 tributaries were analysed in terms of their longitudinal profiles and the application of geomorphic indices (concavity index [Ci], valley floor width-to-height ratio [Vf], and stream-length gradient index [SL]). The analysis reveals two zones with distinctive morphologies: (1) an upper reach domain consisting of broad flat valleys and low-gradient streams where concave longitudinal profiles dominate and (2) a middle reach domain characterised by steep, deeply incised canyons where a convex long profile dominates marking a major kinckzone. The quantitative information on channel shapes and long profile geometries allows the interpretation of these patterns in terms of driving forces for fluvial landscape development. Large-scale morphometric analysis highlights the transient response of the entire basin to a capture-related base level lowering and illustrates the importance of drainage captures as potential

  1. Dismal Swamp Drainage Patterns (United States)

    US Fish and Wildlife Service, Department of the Interior — The natural hydrolics of the Chesapeake Drainage Basin, which has its inception at the crest of the Appalachian mountain range, the waters flowing across the surface...

  2. Prey capture behavior of native vs. nonnative fishes: a case study from the Colorado River drainage basin (USA). (United States)

    Arena, Anthony; Ferry, Lara A; Gibb, Alice C


    The Colorado River drainage basin is home to a diverse but imperiled fish fauna; one putative challenge facing natives is competition with nonnatives. We examined fishes from Colorado River tributaries to address the following questions: Do natives and nonnatives from the same trophic guild consume the same prey items? Will a given species alter its behavior when presented with different prey types? Do different species procure the same prey types via similar feeding behaviors? Roundtail chub (Gila robusta) and smallmouth bass (Micropterus dolomieu), midwater predators, and Sonora sucker (Catostomus insignis) and common carp (Cyprinus carpio), benthic omnivores, were offered six ecologically relevant prey types in more than 600 laboratory trials. Native species consumed a broader array of prey than nonnatives, and species from a given trophic guild demonstrated functional convergence in key aspects of feeding behavior. For example, roundtail chub and smallmouth bass consume prey attached to the substrate by biting, then ripping the prey from its point of attachment; in contrast, Sonora sucker remove attached prey via scraping. When presented with different prey types, common carp, roundtail chub, and smallmouth bass altered their prey capture behavior by modifying strike distance, gape, and angle of attack. Gape varied among the species examined here, with smallmouth bass demonstrating the largest functional and anatomical gape at a given body size. Because fish predators are gape-limited, smallmouth bass will be able to consume a variety of large prey items in the wild, including large, invasive crayfish and young roundtail chub-their presumptive trophic competitors. © 2012 WILEY PERIODICALS, INC.

  3. Factors influencing the composition of detrital heavy mineral suites in Holocene sands of the Apure River drainage basin, Venezuela (United States)

    Morton, Andrew C.


    Heavy mineral assemblages in rivers in the Apure River drainage basin of Venezuela and Colombia closely reflect the nature of the source regions, which lie in the Andean orogenic terranes to the west and northwest. The Caribbean Mountains, largely composed of greenschist-facies pelites, phyllites, carbonates, and metavolcanics, supply assemblages dominated by epidote and calcic amphibole. Minor amounts of the high-pressure index minerals glaucophane and lawsonite indicate the presence of blueschistfacies rocks, reflecting the origin of the Caribbean Mountains by subduction-related tectonism. The northern Mérida Andes, which comprise basement gneisses and granites overlain by unmetamorphosed to low-grade metamorphosed clastics, supply two types of assemblage reflecting these two lithological types: garnet-sillimanite-staurolite-amphibole suites from the basement rocks, and epidote-amphibole suites from the overlying cover sequence. The southern Mérida Andes supply stable heavy mineral suites reflecting recycling from the extensive unmetamorphosed sandstones that occur at outcrop. By considering suites from different physiographical provinces, the effects of short-term alluvial storage in the Llanos on heavy mineral assemblages have been evaluated. Weathering during alluvial storage appears to be effective in modifying the apatite-tourmaline ratio, which shows a steady, marked decline with distance from the mountain front, resulting from the removal of apatite during weathering. Clinopyroxene and garnet may also show evidence of loss through weathering, although the trends are poorly constrained statistically. Epidote and amphibole proportions remain essentially constant, possibly through a balance between loss through weathering and continual resupply from the breakdown of rock fragments. In general, the heavy mineral assemblages are less affected than the bulk mineralogy by alluvial storage on the Llanos.

  4. Characterizing post-drainage succession in Thermokarst Lake Basins on the Seward Peninsula, Alaska with TerraSAR-X Backscatter and Landsat-based NDVI data (United States)

    Regmi, Prajna; Grosse, Guido; Jones, Miriam C.; Jones, Benjamin M.; Walter Anthony, Katey


    Drained thermokarst lake basins accumulate significant amounts of soil organic carbon in the form of peat, which is of interest to understanding carbon cycling and climate change feedbacks associated with thermokarst in the Arctic. Remote sensing is a tool useful for understanding temporal and spatial dynamics of drained basins. In this study, we tested the application of high-resolution X-band Synthetic Aperture Radar (SAR) data of the German TerraSAR-X satellite from the 2009 growing season (July–September) for characterizing drained thermokarst lake basins of various age in the ice-rich permafrost region of the northern Seward Peninsula, Alaska. To enhance interpretation of patterns identified in X-band SAR for these basins, we also analyzed the Normalized Difference Vegetation Index (NDVI) calculated from a Landsat-5 Thematic Mapper image acquired on July 2009 and compared both X-band SAR and NDVI data with observations of basin age. We found significant logarithmic relationships between (a) TerraSAR-X backscatter and basin age from 0 to 10,000 years, (b) Landat-5 TM NDVI and basin age from 0 to 10,000 years, and (c) TerraSAR-X backscatter and basin age from 50 to 10,000 years. NDVI was a better indicator of basin age over a period of 0–10,000 years. However, TerraSAR-X data performed much better for discriminating radiocarbon-dated basins (50–10,000 years old). No clear relationships were found for either backscatter or NDVI and basin age from 0 to 50 years. We attribute the decreasing trend of backscatter and NDVI with increasing basin age to post-drainage changes in the basin surface. Such changes include succession in vegetation, soils, hydrology, and renewed permafrost aggradation, ground ice accumulation and localized frost heave. Results of this study show the potential application of X-band SAR data in combination with NDVI data to map long-term succession dynamics of drained thermokarst lake basins.

  5. Characterizing Post-Drainage Succession in Thermokarst Lake Basins on the Seward Peninsula, Alaska with TerraSAR-X Backscatter and Landsat-based NDVI Data

    Directory of Open Access Journals (Sweden)

    Prajna Regmi


    Full Text Available Drained thermokarst lake basins accumulate significant amounts of soil organic carbon in the form of peat, which is of interest to understanding carbon cycling and climate change feedbacks associated with thermokarst in the Arctic. Remote sensing is a tool useful for understanding temporal and spatial dynamics of drained basins. In this study, we tested the application of high-resolution X-band Synthetic Aperture Radar (SAR data of the German TerraSAR-X satellite from the 2009 growing season (July–September for characterizing drained thermokarst lake basins of various age in the ice-rich permafrost region of the northern Seward Peninsula, Alaska. To enhance interpretation of patterns identified in X-band SAR for these basins, we also analyzed the Normalized Difference Vegetation Index (NDVI calculated from a Landsat-5 Thematic Mapper image acquired on July 2009 and compared both X-band SAR and NDVI data with observations of basin age. We found significant logarithmic relationships between (a TerraSAR-X backscatter and basin age from 0 to 10,000 years, (b Landat-5 TM NDVI and basin age from 0 to 10,000 years, and (c TerraSAR-X backscatter and basin age from 50 to 10,000 years. NDVI was a better indicator of basin age over a period of 0–10,000 years. However, TerraSAR-X data performed much better for discriminating radiocarbon-dated basins (50–10,000 years old. No clear relationships were found for either backscatter or NDVI and basin age from 0 to 50 years. We attribute the decreasing trend of backscatter and NDVI with increasing basin age to post-drainage changes in the basin surface. Such changes include succession in vegetation, soils, hydrology, and renewed permafrost aggradation, ground ice accumulation and localized frost heave. Results of this study show the potential application of X-band SAR data in combination with NDVI data to map long-term succession dynamics of drained thermokarst lake basins.

  6. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: Artificial Drainage (1992) and Irrigation (1997) (United States)

    Wieczorek, Michael; LaMotte, Andrew E.


    This tabular data set represents the estimated area of artifical drainage for the year 1992 and irrigation types for the year 1997 compiled for every MRB_E2RF1 catchment of Major River Basins (MRBs, Crawford and others, 2006). The source data sets were derived from tabular National Resource Inventory (NRI) data sets created by the National Resources Conservation Service (NRCS, U.S. Department of Agriculture, 1995, 2000). Artificial drainage is defined as subsurface drains and ditches. Irrigation types are defined as gravity and pressure. Subsurface drains are described as conduits, such as corrugated plastic tubing, tile, or pipe, installed beneath the ground surface to collect and/or convey drainage. Surface drainage field ditches are described as graded ditches for collecting excess water. Gravity irrigation source is described as irrigation delivered to the farm and/or field by canals or pipelines open to the atmosphere; and water is distributed by the force of gravity down the field by: (1) A surface irrigation system (border, basin, furrow, corrugation, wild flooding, etc.) or (2) Sub-surface irrigation pipelines or ditches. Pressure irrigation source is described as irrigation delivered to the farm and/or field in pump or elevation-induced pressure pipelines, and water is distributed across the field by: (1) Sprinkle irrigation (center pivot, linear move, traveling gun, side roll, hand move, big gun, or fixed set sprinklers), or (2) Micro irrigation (drip emitters, continuous tube bubblers, micro spray or micro sprinklers). NRI data do not include Federal lands and are thus excluded from this dataset. The tabular data for drainage were spatially apportioned to the National Land Cover Dataset (NLCD, Kerie Hitt, U.S. Geological Survey, written commun., 2005) and the tabular data for irrigation were spatially apportioned to an enhanced version of the National Land Cover Dataset (NLCDe, Nakagaki and others, 2007). The MRB_E2RF1 catchments are based on a modified

  7. Bedrock geologic map of the Spring Valley, West Plains, and parts of the Piedmont and Poplar Bluff 30'x60' quadrangles, Missouri, including the upper Current River and Eleven Point River drainage basins (United States)

    Weary, David J.; Harrison, Richard W.; Orndorff, Randall C.; Weems, Robert E.; Schindler, J. Stephen; Repetski, John E.; Pierce, Herbert A.


    This map covers the drainage basins of the upper Current River and the Eleven Point River in the Ozark Plateaus physiographic province of southeastern Missouri. The two surface drainage basins are contiguous in their headwaters regions, but are separated in their lower reaches by the lower Black River basin in the southeast corner of the map area. Numerous dye-trace studies demonstrate that in the contiguous headwaters areas, groundwater flows from the Eleven Point River basin into the Current River basin. Much of the groundwater discharge of the Eleven Point River basin emanates from Big Spring, located on the Current River. This geologic map and cross sections were produced to help fulfill a need to understand the geologic framework of the region in which this subsurface flow occurs.

  8. Holocene Evolution of the Indus River Basin: the effect of climate and drainage reorganization on the Harappan (United States)

    Alizai, A. H.; Clift, P. D.; Vanlaningham, S.; Giosan, L.; Carter, A.; Hillier, S.; Macklin, M. G.; Duller, G. A.; Durcan, J.


    The Indus River basin has evolved significantly during the Holocene and may have affected the Harappan Civilization which is believed to have collapsed around 2000 BC. We aim to understand the links between drainage evolution, the intensity of the South Asian Monsoon and the development of this early human society. Sediment was sampled from modern rivers, pits and shallow boreholes in the alluvial plains of the Indus and the inactive Ghaggar-Hakra tributary. A suite of techniques are used to resolve sediment source changes during, the Holocene, including bulk and clay mineralogy (XRD), garnet geochemistry, U-Pb dating of zircon grains, Ar-Ar dating of mica, and bulk Nd isotopic analyses. We report preliminary 14C and optically-stimulated luminescence (OSL) ages, U-Pb dating of zircon and mineralogical data from a delta core site (Keti Bandar), as well as two core sites and two shallow pits from the eastern upper Indus flood plain. Sediments from the delta show that the mineralogical changes are coherent with the regional climate changes in the Early Holocene. XRD mineralogy shows that illite concentrations peak around 14% in Early Holocene and decrease to 4% around 8 ka, while plagioclase feldspar ranges from 9% in the Early Holocene to 17% at the peak of the monsoon. The mineralogy in general shows a coherent trend when plotted against oxygen isotope measurements from speleothems. 14C and OSL age results from the eastern Indus flood plain cluster around 5-6 ka suggesting an active river at and before this time, and coincide with when the Harappan flourished. This eastern palaeo-tributary (Ghaggar-Hakra) of Indus drains the Lesser and the Higher Himalayas and is different from the trunk Indus stream which has sediment derived mainly from the Karakoram, Transhimalayas, Hindu Kush and Kohistan ranges. U-Pb zircon ages from Mid-Holocene sands along the path of the Ghaggar-Hakra River are very similar to the Indus and Thar Desert sands. We suggest that the Ghaggar

  9. The Baltic Sea Experiment (BALTEX): A European contribution to the investigation of the energy and water cycle over a large drainage basin

    DEFF Research Database (Denmark)

    Raschke, E.; Meywerk, J.; Warrach, K.


    The Baltic Sea Experiment (BALTEX) is one of the five continental-scale experiments of the Global Energy and Water Cycle Experiment (GEWEX). More than 50 research groups from 14 European countries are participating in this project to measure and model the energy and water cycle over the large...... drainage basin of the Baltic Sea in northern Europe. BALTEX aims to provide a better understanding of the processes of the climate system and to improve and to validate the water cycle in regional numerical models for weather forecasting and climate studies. A major effort is undertaken to couple...

  10. Status and understanding of groundwater quality in the San Diego Drainages Hydrogeologic Province, 2004: California GAMA Priority Basin Project (United States)

    Wright, Michael T.; Belitz, Kenneth


    Groundwater quality in the approximately 3,900-square-mile (mi2) San Diego Drainages Hydrogeologic Province (hereinafter San Diego) study unit was investigated from May through July 2004 as part of the Priority Basin Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The study unit is located in southwestern California in the counties of San Diego, Riverside, and Orange. The GAMA Priority Basin Project is being conducted by the California State Water Resources Control Board in collaboration with the U.S. Geological Survey (USGS) and the Lawrence Livermore National Laboratory. The GAMA San Diego study was designed to provide a statistically robust assessment of untreated-groundwater quality within the primary aquifer systems. The assessment is based on water-quality and ancillary data collected by the USGS from 58 wells in 2004 and water-quality data from the California Department of Public Health (CDPH) database. The primary aquifer systems (hereinafter referred to as the primary aquifers) were defined by the depth interval of the wells listed in the California Department of Public Health (CDPH) database for the San Diego study unit. The San Diego study unit consisted of four study areas: Temecula Valley (140 mi2), Warner Valley (34 mi2), Alluvial Basins (166 mi2), and Hard Rock (850 mi2). The quality of groundwater in shallow or deep water-bearing zones may differ from that in the primary aquifers. For example, shallow groundwater may be more vulnerable to surficial contamination than groundwater in deep water-bearing zones. This study had two components: the status assessment and the understanding assessment. The first component of this study-the status assessment of the current quality of the groundwater resource-was assessed by using data from samples analyzed for volatile organic compounds (VOC), pesticides, and naturally occurring inorganic constituents, such as major ions and trace elements. The status assessment is intended to

  11. Application of a watershed model (HSPF) for evaluating sources and transport of pathogen indicators in the Chino Basin drainage area, San Bernardino County, California (United States)

    Hevesi, Joseph A.; Flint, Lorraine E.; Church, Clinton D.; Mendez, Gregory O.


    A watershed model using Hydrologic Simulation Program-FORTRAN (HSPF) was developed for the urbanized Chino Basin in southern California to simulate the transport of pathogen indicator bacteria, evaluate the flow-component and land-use contributions to bacteria contamination and water-quality degradation throughout the basin, and develop a better understanding of the potential effects of climate and land-use change on water quality. The calibration of the model for indicator bacteria was supported by historical data collected before this study and by samples collected by the U.S. Geological Survey from targeted land-use areas during storms in water-year 2004. The model was successfully calibrated for streamflow at 5 gage locations representing the Chino Creek and Mill Creek drainages. Although representing pathogens as dissolved constituents limits the model's ability to simulate the transport of pathogen indicator bacteria, the bacteria concentrations measured over the period 1998-2004 were well represented by the simulated concentrations for most locations. Hourly concentrations were more difficult to predict because of high variability in measured bacteria concentrations. In general, model simulations indicated that the residential and commercial land uses were the dominant sources for most of the pathogen indicator bacteria during low streamflows. However, simulations indicated that land used for intensive livestock (dairies and feedlots) and mixed agriculture contributed the most bacteria during storms. The calibrated model was used to evaluate how various land use, air temperature, and precipitation scenarios would affect flow and transport of bacteria. Results indicated that snow pack formation and melt were sensitive to changes in air temperature in the northern, mountainous part of the Chino Basin, causing the timing and magnitude of streamflow to shift in the natural drainages and impact the urbanized areas of the central Chino Basin. The relation between

  12. Modelling density-dependent flow and solute transport at the Lake Tutchewop saline disposal complex, Victoria (United States)

    Simmons, Craig T.; Narayan, Kumar A.


    Intercepted saline groundwaters and drainage effluent from irrigation are commonly stored in both natural and artificial saline disposal basins throughout the Murray-Darling Basin of Australia. Their continued use as wastewater evaporation sites requires an understanding of existing groundwater dynamics. The useful of individual basins, their sustainability and possible environmental impacts remain largely unknown. In this work, the movement of salt to the underlying groundwater system from Lake Tutchewop, a saline disposal complex in north-central Victoria, was modelled in cross-section. Due to the salinity contrast between the hypersaline basin waters and the regional groundwater, it was necessary to simulate density-dependent flow behaviour. Under certain conditions, these density-stratified systems may become unstable leading to the onset of convective behaviour, which greatly increases the movement of salt from the basin to the groundwater system. Modelled concentration profiles in the aquifer system and calculated seepage rates from the basin show that Lake Tutchewop is stable under its present operating regime. The downward movement of salt is mainly controlled by diffusion and dispersion. The calibrated model was used to assess the impact of several management scenarios using time-dependent boundary conditions for lake salinity and water levels. The influence of heterogeneous basin linings on ensuing salt flux rates is examined, and results show that increased solute transport will occur under such conditions. A sensitivity analysis performed on governing variables showed that salt fluxes were most sensitive to lake salinity levels. A solute Rayleigh number defined in terms of basin salinity and hydrogeologic parameters is seen to be an effective tool for predicting the long term behaviour of such saline disposal basins. The models and concepts developed in this work may find application in the design and management of saline disposal complexes.

  13. Universality and variability in the 2D form of drainage basins: a study of active orogens and passive margins (United States)

    Walcott, R. C.; Summerfield, M. A.


    Identifying the controls on basin morphology is needed to understand how landscapes evolve under changing conditions. Some important morphological and topological relationships such as Hack's and Horton/Tokunagas" laws suggest that river basins, irrespective of the climatic, tectonic and/or biogeographic conditions under which they developed, are likely to have statistically predictable planform morphologies. Indeed empirical studies of the spacing between basins that drain the main divide of some active and inactive orogens suggest that this may be the case. In such situations major basins typically have an outlet spacing that is approximately half of the distance between the outlet and the main divide. However, notable deviations from this outlet spacing relationship have also been documented. We therefore address the question: what controls the planform morphology or "packing arrangement" of river basins (of all scales) on the flanks of orogens? To answer this question we conducted a study of basin morphology from both active mountain belts (e.g. Himalaya and Andes) and from morphological similar, but tectonically very different, passive margins (e.g. southeast Africa). We specifically investigate the relationship between basin outlet spacing and other two dimensional geometric properties such as basin length, main valley length and basin area. We show that if the rate of relative displacement between the main divide and outlet is slower than the rate of river erosion then, river basins, irrespective of size, tend towards an approximately diamond shaped packing arrangement in which the basin width is approximately half that of basin length. However, where relative displacement between the main divide and outlet has exceeds the rate of river erosion, such as in the western Himalaya, rivers are forced into an alternative, and possibly unstable packing arrangement.

  14. Investigating the effect of plate-mantle interaction in basin creation and associated drainage systems: insights from the North West Shelf of Australia (United States)

    Morón, S.; Gallagher, S. J.; Moresi, L. N.; Salles, T.; Rey, P. F.; Payenberg, T.


    The effect of plate-mantle dynamics on surface topography has increasingly being recognized. This concept is particularly useful for the understanding of the links between plate-mantle dynamics, continental break up and the creation of sedimentary basins and their associated drainage systems. To unravel these links back in time we present an approach that uses numerical models and the geological record. The sedimentary basins of the North West Shelf (NWS) of Australia contain an exceptional record of the Permian to early Cretaceous polyphased rifting of Australia from Greater India, which is in turn associated with the breakup of Gondwana. This record and the relative tectonic quiescence of the Australian Continent since the Late Cretaceous make the NWS a great natural laboratory for investigating the interaction between mantle dynamics, plate tectonics and drainage patterns. Furthermore, as a result of the extensive petroleum exploration and production in the area a uniquely large dataset containing seismic, lithologic, biostratigraphic and detrital zircon information is already available. This study will first focus on augmenting zircon datasets to refine the current conceptual models of paleodrainage systems associated with the NWS. Current conceptual models of drainage patterns suggest the previous existance of large transcontinental rivers that transported sediments from Antarctica and India, rather than from more proximal Australian sources. From a mass-balance point of view this model seems reasonable, as large transcontinental rivers would be required to transport the significant volume of sediments that are deposited in the thick (15km) sedimentary sequences of the NWS. Coupling of geodynamic (Underworld) and landscape-dynamics (Badlands) models will allow us to numerically test the likelihood of this conceptual model and also to present and integrated approach to investigate the link between deep Earth processes and surficial processes.

  15. Paleoenvironmental context of the Middle Stone Age record from Karungu, Lake Victoria Basin, Kenya, and its implications for human and faunal dispersals in East Africa. (United States)

    Faith, J Tyler; Tryon, Christian A; Peppe, Daniel J; Beverly, Emily J; Blegen, Nick; Blumenthal, Scott; Chritz, Kendra L; Driese, Steven G; Patterson, David


    The opening and closing of the equatorial East African forest belt during the Quaternary is thought to have influenced the biogeographic histories of early modern humans and fauna, although precise details are scarce due to a lack of archaeological and paleontological records associated with paleoenvironmental data. With this in mind, we provide a description and paleoenvironmental reconstruction of the Late Pleistocene Middle Stone Age (MSA) artifact- and fossil-bearing sediments from Karungu, located along the shores of Lake Victoria in western Kenya. Artifacts recovered from surveys and controlled excavations are typologically MSA and include points, blades, and Levallois flakes and cores, as well as obsidian flakes similar in geochemical composition to documented sources near Lake Naivasha (250 km east). A combination of sedimentological, paleontological, and stable isotopic evidence indicates a semi-arid environment characterized by seasonal precipitation and the dominance of C4 grasslands, likely associated with a substantial reduction in Lake Victoria. The well-preserved fossil assemblage indicates that these conditions are associated with the convergence of historically allopatric ungulates from north and south of the equator, in agreement with predictions from genetic observations. Analysis of the East African MSA record reveals previously unrecognized north-south variation in assemblage composition that is consistent with episodes of population fragmentation during phases of limited dispersal potential. The grassland-associated MSA assemblages from Karungu and nearby Rusinga Island are characterized by a combination of artifact types that is more typical of northern sites. This may reflect the dispersal of behavioral repertoires-and perhaps human populations-during a paleoenvironmental phase dominated by grasslands. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Water-Quality Characteristics for Sites in the Tongue, Powder, Cheyenne, and Belle Fourche River Drainage Basins, Wyoming and Montana, Water Years 2001-05, with Temporal Patterns of Selected Long-Term Water-Quality Data (United States)

    Clark, Melanie L.; Mason, Jon P.


    Water-quality sampling was conducted regularly at stream sites within or near the Powder River structural basin in northeastern Wyoming and southeastern Montana during water years 2001-05 (October 1, 2000, to September 30, 2005) to characterize water quality in an area of coalbed natural gas development. The U.S. Geological Survey, in cooperation with the Wyoming Department of Environmental Quality, characterized the water quality at 22 sampling sites in the Tongue, Powder, Cheyenne, and Belle Fourche River drainage basins. Data for general hydrology, field measurements, major-ion chemistry, and selected trace elements were summarized, and specific conductance and sodium-adsorption ratios were evaluated for relations with streamflow and seasonal variability. Trend analysis for water years 1991-2005 was conducted for selected sites and constituents to assess change through time. Average annual runoff was highly variable among the stream sites. Generally, streams that have headwaters in the Bighorn Mountains had more runoff as a result of higher average annual precipitation than streams that have headwaters in the plains. The Powder River at Moorhead, Mont., had the largest average annual runoff (319,000 acre-feet) of all the sites; however, streams in the Tongue River drainage basin had the highest runoff per unit area of the four major drainage basins. Annual runoff in all major drainage basins was less than average during 2001-05 because of drought conditions. Consequently, water-quality samples collected during the study period may not represent long-term water-quality con-ditions for all sites. Water-quality characteristics were highly variable generally because of streamflow variability, geologic controls, and potential land-use effects. The range of median specific-conductance values among sites was smallest in the Tongue River drainage basin. Median values in that basin ranged from 643 microsiemens per centimeter at 25 degrees Celsius (?S/cm at 25?C) on the

  17. Evaluation of different digital elevation models for analyzing drainage morphometric parameters in a mountainous terrain: a case study of the Supin-Upper Tons Basin, Indian Himalayas. (United States)

    Das, Sayantan; Patel, Priyank Pravin; Sengupta, Somasis


    With myriad geospatial datasets now available for terrain information extraction and particularly streamline demarcation, there arises questions regarding the scale, accuracy and sensitivity of the initial dataset from which these aspects are derived, as they influence all other parameters computed subsequently. In this study, digital elevation models (DEM) derived from Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER V2), Shuttle Radar Topography Mission (SRTM V4, C-Band, 3 arc-second), Cartosat -1 (CartoDEM 1.0) and topographical maps (R.F. 1:250,000 and 1:50,000), have been used to individually extract and analyze the relief, surface, size, shape and texture properties of a mountainous drainage basin. Nestled inside a mountainous setting, the basin is a semi-elongated one with high relief ratio (>90), steep slopes (25°-30°) and high drainage density (>3.5 km/sq km), as computed from the different DEMs. The basin terrain and stream network is extracted from each DEM, whose morphometric attributes are compared with the surveyed stream networks present in the topographical maps, with resampling of finer DEM datasets to coarser resolutions, to reduce scale-implications during the delineation process. Ground truth verifications for altitudinal accuracy have also been done by a GPS survey. DEMs derived from the 1:50,000 topographical map and ASTER GDEM V2 data are found to be more accurate and consistent in terms of absolute accuracy, than the other generated or available DEM data products, on basis of the morphometric parameters extracted from each. They also exhibit a certain degree of proximity to the surveyed topographical map.

  18. Genetic and Phenotypic Catalog of Native Resident Trout of the interior Columbia River Basin : FY-2001 Report : Populations in the Wenatchee, Entiat, Lake Chelan and Methow River Drainages.

    Energy Technology Data Exchange (ETDEWEB)

    Trotter, Patrick C.


    The 1994 Fish and Wildlife Program of the Northwest Power Planning Council specifies the recovery and preservation of population health of native resident fishes of the Columbia River Basin. Among the native resident species of concern are interior rainbow trout of the Columbia River redband subspecies Oncorhynchus mykiss gairdneri 1 and westslope cutthroat trout O. clarki lewisi. The westslope cutthroat trout has been petitioned for listing under the U. S. Endangered Species Act (American Wildlands et al. 1997). Before at-risk populations can be protected, their presence and status must be established. Where introgression from introduced species is a concern, as in the case of both westslope cutthroat trout and redband rainbow trout, genetic issues must be addressed as well. As is true with native trout elsewhere in the western United States (Behnke 1992), most of the remaining pure populations of these species in the Columbia River Basin are in relatively remote headwater reaches. The objective of this project was to photo-document upper Columbia Basin native resident trout populations in Washington, and to ascertain their species or subspecies identity and relative genetic purity using a nonlethal DNA technique. FY-2001 was year three (and final year) of a project in which we conducted field visits to remote locations to seek out and catalog these populations. In FY-2001 we worked in collaboration with the Wenatchee National Forest to catalog populations in the Wenatchee, Entiat, Lake Chelan, and Methow River drainages of Washington State.

  19. Chronology of fluvial terrace sequences for large Atlantic rivers in the Iberian Peninsula (Upper Tagus and Duero drainage basins, Central Spain) (United States)

    Silva, Pablo G.; Roquero, Elvira; López-Recio, Mario; Huerta, Pedro; Martínez-Graña, Antonio M.


    This work analyses the chronology of fluvial terrace sequences of the two most important fluvial basins from central Spain draining to the Atlantic Ocean (Upper Tagus and Duero drainage basins). Both basins evolved under similar Mediterranean climatic conditions throughout the Pleistocene and present comparable number of fluvial terraces (16-17) after excluding the higher terrace levels of the Tagus (T1-T5) entrenched in the Raña surface. These higher ;rañizo terraces; was formed in response to fan-head trenching in this high alluvial piedmont (+220 m) and therefore not properly controlled by Quaternary fluvial downcutting. The study accomplishes the implementation of multiple regression analyses for terrace height-age relationships. To transform relative terrace heights above the present river thalwegs (i.e. +100 m) in numerical ages a ;height-age transference function; has been developed on the basis of preliminary statistical geochronological approaches proposed for Central Spain. The resultant height-age transference function gather 73 published geochronological data for terrace sequences, featuring a 3rd Order Polynomial Function (R2 0.90). This function describes the overall trend of valley downcutting for the last c. 2.3 Ma in Central Spain and is used to assign numerical ages to terrace levels at different relative elevation.

  20. Prognostic Role of Multiple Lymphatic Basin Drainage in Sentinel Lymph Node-Negative Trunk Melanoma Patients: A Multicenter Study from the Italian Melanoma Intergroup. (United States)

    Ribero, Simone; Osella-Abate, Simona; Pasquali, Sandro; Rossi, Carlo Riccardo; Borgognoni, Lorenzo; Piazzalunga, Dario; Solari, Nicola; Schiavon, Mauro; Brandani, Paola; Ansaloni, Luca; Ponte, Erica; Silan, Francesco; Sommariva, Antonio; Bellucci, Francesco; Macripò, Giuseppe; Quaglino, Pietro


    Multiple lymphatic basin drainage (MLBD) is frequently observed in patients with trunk melanoma undergoing sentinel lymph node (SLN) biopsy. Conflicting data regarding the prognostic association of MLBD in SLN-negative patients have been reported. This study aimed to investigate the prognostic role of MLBD in patients with negative SLN biopsy. Retrospective data from 656 melanoma patients who underwent a SLN biopsy (1991-2012) at six Italian centers were gathered in a multicenter database. MLBD was defined as lymphoscintigraphic and intraoperative identification of an SLN in more than one nodal basin. Clinical and pathologic variables were recorded and analyzed for their impact on survival. SLN-negative patients with MLBD were at lower risk of melanoma recurrence [hazard ratio (HR) 0.73, P = 0.05) and melanoma-related death (HR 0.68, P = 0.001) independent of common staging features. Multivariable Cox analyses of disease-free interval (DFI) and disease-specific survival (DSS) showed that MLBD maintained a favorable role and ulceration an unfavorable role. Histologic regression was independently associated only with DFI. When survival was stratified according to presence of MLBD, histologic regression and Breslow thickness lymphatic basins are identified and analyzed. Further research is required to investigate the mechanisms behind this evidence.

  1. Health risks from large-scale water pollution: Current trends and implications for improving drinking water quality in the lower Amu Darya drainage basin, Uzbekistan (United States)

    Törnqvist, Rebecka; Jarsjö, Jerker


    Safe drinking water is a primary prerequisite to human health, well being and development. Yet, there are roughly one billion people around the world that lack access to safe drinking water supply. Health risk assessments are effective for evaluating the suitability of using various water sources as drinking water supply. Additionally, knowledge of pollutant transport processes on relatively large scales is needed to identify effective management strategies for improving water resources of poor quality. The lower Amu Darya drainage basin close to the Aral Sea in Uzbekistan suffers from physical water scarcity and poor water quality. This is mainly due to the intensive agriculture production in the region, which requires extensive freshwater withdrawals and use of fertilizers and pesticides. In addition, recurrent droughts in the region affect the surface water availability. On average 20% of the population in rural areas in Uzbekistan lack access to improved drinking water sources, and the situation is even more severe in the lower Amu Darya basin. In this study, we consider health risks related to water-borne contaminants by dividing measured substance concentrations with health-risk based guideline values from the World Health Organisation (WHO). In particular, we analyse novel results of water quality measurements performed in 2007 and 2008 in the Mejdurechye Reservoir (located in the downstream part of the Amu Darya river basin). We furthermore identify large-scale trends by comparing the Mejdurechye results to reported water quality results from a considerable stretch of the Amu Darya river basin, including drainage water, river water and groundwater. The results show that concentrations of cadmium and nitrite exceed the WHO health-risk based guideline values in Mejdurechye Reservoir. Furthermore, concentrations of the since long ago banned and highly toxic pesticides dichlorodiphenyltrichloroethane (DDT) and γ-hexachlorocyclohexane (γ-HCH) were detected in

  2. Orbital forcing of glacial/interglacial variations in chemical weathering within the White Nile basin: stable-isotope and biomarker evidence from Lakes Victoria and Edward (United States)

    Cockerton, Helen E.; Alayne Street-Perrott, F.; Barker, Philip A.; Leng, Melanie J.; Sloane, Hilary J.; Horstwood, Matthew S. A.; Snelling, Andrea


    The continental Si cycle on Quaternary time scales has been largely neglected. Emphasis has been placed on long-term geochemical processes of silicate-rock weathering and the resulting drawdown of atmospheric CO2, rather than on shorter-term biogenic processes occurring along the land-ocean continuum. Si-accumulating plants (notably tropical rainforest hardwoods, savanna and wetland grasses, and Papyrus) and aquatic organisms (such as diatoms and sponges in lakes, rivers and swamps) have the potential to take up, store and recycle significant amounts of Si, thereby modifying the riverine flux of Si to the oceans, the productivity of siliceous marine organisms and the rate of atmospheric CO2 drawdown on an orbital time scale. The main aim of this study was to investigate spatial and temporal patterns of Si cycling along the Nile system during the last 20ka BP. Utilising sediment cores from Lakes Victoria and Edward, coupled measurements of stable Si and O isotopes on cleaned diatom separates were employed to reconstruct millennial-scale variations in biotic Si cycling and palaeohydrology, respectively. Abundance ratios of lipid biomarkers (n-alkanes) were used to track major changes in terrestrial and aquatic ecosystems. The results have been interpreted in the light of multi-isotope analyses (2H,18O,30Si) of modern water samples collected along the courses of the modern White and Blue Niles during both wet- and dry-season conditions. During drier intervals (the Last Glacial Maximum and the late Holocene: high 18Odiatom), Si cycling was greatly reduced. Diminished vegetation cover, reduced biotic rock weathering, a declining soil stock of amorphous silica (ASi) and decreased runoff resulted in reduced dissolved silica (DSi) supply to the lakes in relation to aquatic demand (high 30Sidiatom). In contrast, enhanced monsoon rainfall (low 18Odiatom) during the early to mid-Holocene promoted a substantial increase in terrestrial biomass within the White Nile headwaters

  3. Hydrogeology and hydrogeochemistry at a site of strategic importance: the Pareja Limno-reservoir drainage basin (Guadalajara, central Spain) (United States)

    Molina-Navarro, Eugenio; Sastre-Merlín, Antonio; Vicente, Rosa; Martínez-Pérez, Silvia


    A small calcareous basin in central Spain was studied to establish the role of groundwater in the Pareja Limno-reservoir. Limno-reservoirs aim to preserve a constant water level in the riverine zone of large reservoirs to mitigate the impacts arising from their construction. Groundwater flow contribution (mean 60 %) was derived by recharge estimation. In situ measurements (spring discharge, electrical conductivity and sulfate) were undertaken and spring discharge was compared with a drought index. Twenty-eight springs were monitored and three hydrogeological units (HGUs) were defined: a carbonate plateau (HGU1), the underlying aquitard (HGU2), and the gypsum-enriched HGU3. HGU1 is the main aquifer and may play a role in the preservation of the limno-reservoir water level. Hydrogeochemical sampling was conducted and the code PHREEQC used to describe the main geochemical processes. Weathering and dissolution of calcite and gypsum seem to control the hydrogeochemical processes in the basin. Water progresses from Ca2+-HCO3 - in the upper basin to Ca2+-SO4 2- in the lower basin, where HGU3 outcrops. A clear temporal pattern was observed in the limno-reservoir, with salinity decreasing in winter and increasing in summer. This variation was wider at the river outlet, but the mixing of the river discharge with limno-reservoir water buffered it.

  4. San Mateo Creek Basin (United States)

    The San Mateo Creek Basin comprises approximately 321 square miles within the Rio San Jose drainage basin in McKinley and Cibola counties, New Mexico. This basin is located within the Grants Mining District (GMD).

  5. Multivariate geostatistical modeling of the spatial sediment distribution in a large scale drainage basin, Upper Rhone, Switzerland (United States)

    Schoch, Anna; Blöthe, Jan Henrik; Hoffmann, Thomas; Schrott, Lothar


    There is a notable discrepancy between detailed sediment budget studies in small headwater catchments ( 103 km2) in higher order catchments applying modeling and/or remote sensing based approaches for major sediment storage delineation. To bridge the gap between these scales, we compiled an inventory of sediment and bedrock coverage from field mapping, remote sensing analysis and published data for five key sites in the Upper Rhone Basin (Val d'Illiez, Val de la Liène, Turtmanntal, Lötschental, Goms; 360.3 km2, equivalent to 6.7% of the Upper Rhone Basin). This inventory was used as training and testing data for the classification of sediment and bedrock cover. From a digital elevation model (2 × 2 m ground resolution) and Landsat imagery we derived 22 parameters characterizing local morphometry, topography and position, contributing area, and climatic and biotic factors on different spatial scales, which were used as inputs for different statistical models (logistic regression, principal component logistic regression, generalized additive model). Best prediction results with an excellent performance (mean AUROC: 0.8721 ± 0.0012) and both a high spatial and non-spatial transferability were achieved applying a generalized additive model. Since the model has a high thematic consistency, the independent input variables chosen based on their geomorphic relevance are suitable to model the spatial distribution of sediment. Our high-resolution classification shows that 53.5 ± 21.7% of the Upper Rhone Basin are covered with sediment. These are by no means evenly distributed: small headwaters (constitutes a significant component of large scale sediment budgets that needs to be better included into future analysis.

  6. Solute load concentrations in some streams in the Upper Osun and Owena drainage basins, central western Nigeria (United States)

    Jeje, L. K.; Ogunkoya, O. O.; Oluwatimilehin, J. M.


    The solute load dynamics of 12 third-order streams in central western Nigeria are presented, during storm and non-storm runoff events. The relevance of the Walling and Foster model for explaining storm period solute load dynamics in the humid tropical environment was assessed and it was found that this model was generally applicable to the study area. Exceptions appear to be streams draining settlements and/or farms where fertilizers are applied heavily. The solute load ranged from 5 mg l -1 to 580 mg l -1 with streams draining basins with tree-crop plantations ( Theobroma cacao, Cola sp.) as the dominant land cover having the highest solute load.

  7. Hierarchy of factors exerting an impact on nutrient load of the Baltic Sea and sustainable management of its drainage basin. (United States)

    Kiedrzyńska, Edyta; Jóźwik, Adam; Kiedrzyński, Marcin; Zalewski, Maciej


    The aim of the paper was to evaluate 23 catchment factors that determine total phosphorus and total nitrogen load to the Baltic Sea. Standard correlation analysis and clustering were used. Both phosphorus and nitrogen loads were found to be positively related to the number of pigs and the human population associated with wastewater treatment plants (WWTPs) per km(2), while the number of cattle and agricultural area were found to influence nitrogen rather than phosphorus load, and the area of forests is negatively related to loads of both nutrients. Clustering indicates an overall north-south pattern in the spatial co-occurrence of socio-ecological factors, with some exceptions discussed in the paper. Positive steps in the Baltic Sea region have already been taken, but much remains to be done. The development of coherent response policies to reduce eutrophication in the Baltic Sea should be based on a comprehensive knowledge base, an appropriate information strategy and learning alliance platform in each drainage river catchments. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Metal transport and remobilisation in a basin affected by acid mine drainage: the role of ochreous amorphous precipitates. (United States)

    Consani, Sirio; Carbone, Cristina; Dinelli, Enrico; Balić-Žunić, Tonci; Cutroneo, Laura; Capello, Marco; Salviulo, Gabriella; Lucchetti, Gabriella


    Metal-polluted mine waters represent a major threat to the quality of waters and sediments in a downstream basin. At the confluence between acidic mine waters and the unpolluted waters of the Gromolo Torrent (Liguria, North-West Italy), the massive formation of an ochreous amorphous precipitate takes place. This precipitate forms a soft blanket that covers the torrent bed and can be observed down to its mouth in the sea. The aim of this work is to evaluate the dispersion of metals in the Gromolo Torrent basin from the abandoned Cu-Fe sulphide mine of Libiola to the Ligurian Sea and to assess the metal remobilisation from the amorphous precipitates. The mineralogy of the superficial sediments collected in the torrent bed and the concentrations of different elements of environmental concern (Cu, Zn, Cd, Co, Cr, Mn, Ni, Pb, As, and Sb) were therefore analysed. The results showed that the precipitates contain high concentration of Fe, Al, Cu, and Zn, significantly modifying the bulk chemistry of the Gromolo Torrent sediments. In order to evaluate the possible remobilisation of ecotoxic elements from the amorphous precipitates, bulk leaching tests were performed with both deionised and seawater. Bulk leaching tests with deionised water mobilised primarily high Pb amounts, but also relatively high concentrations of Fe, Al, Cu, and Zn are released in the leachate. In seawater tests, Fe, Al, Cu, and Zn were released in smaller amounts, while other elements like Mn, Cd, Co, and Ni increased in the released fraction. Pb was still strongly released as in deionised water experiments. The results show that the interaction of precipitates and seawater can remobilise high concentrations of metals, thus affecting the surrounding environment.

  9. Development of urban runoff model FFC-QUAL for first-flush water-quality analysis in urban drainage basins. (United States)

    Hur, Sungchul; Nam, Kisung; Kim, Jungsoo; Kwak, Changjae


    An urban runoff model that is able to compute the runoff, the pollutant loadings, and the concentrations of water-quality constituents in urban drainages during the first flush was developed. This model, which is referred to as FFC-QUAL, was modified from the existing ILLUDAS model and added for use during the water-quality analysis process for dry and rainy periods. For the dry period, the specifications of the coefficients for the discharge and water quality were used. During rainfall, we used the Clark and time-area methods for the runoff analyses of pervious and impervious areas to consider the effects of the subbasin shape; moreover, four pollutant accumulation methods and the washoff equation for computing the water quality each time were used. According to the verification results, FFC-QUAL provides generally similar output as the measured data for the peak flow, total runoff volume, total loadings, peak concentration, and time of peak concentration for three rainfall events in the Gunja subbasin. In comparison with the ILLUDAS, SWMM, and MOUSE models, there is little difference between these models and the model developed in this study. The proposed model should be useful in urban watersheds because of its simplicity and its capacity to model common pollutants (e.g., biological oxygen demand, chemical oxygen demand, Escherichia coli, suspended solids, and total nitrogen and phosphorous) in runoff. The proposed model can also be used in design studies to determine how changes in infrastructure will affect the runoff and pollution loads. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  10. Effects of Abandoned Coal-Mine Drainage on Streamflow and Water Quality in the Mahanoy Creek Basin, Schuylkill, Columbia, and Northumberland Counties, Pennsylvania, 2001 (United States)

    Cravotta, Charles A.


    This report assesses the contaminant loading, effects to receiving streams, and possible remedial alternatives for abandoned mine drainage (AMD) within the Mahanoy Creek Basin in east-central Pennsylvania. The Mahanoy Creek Basin encompasses an area of 157 square miles (407 square kilometers) including approximately 42 square miles (109 square kilometers) underlain by the Western Middle Anthracite Field. As a result of more than 150 years of anthracite mining in the basin, ground water, surface water, and streambed sediments have been adversely affected. Leakage from streams to underground mines and elevated concentrations (above background levels) of acidity, metals, and sulfate in the AMD from flooded underground mines and (or) unreclaimed culm (waste rock) degrade the aquatic ecosystem and impair uses of the main stem of Mahanoy Creek from its headwaters to its mouth on the Susquehanna River. Various tributaries also are affected, including North Mahanoy Creek, Waste House Run, Shenandoah Creek, Zerbe Run, and two unnamed tributaries locally called Big Mine Run and Big Run. The Little Mahanoy Creek and Schwaben Creek are the only major tributaries not affected by mining. To assess the current hydrological and chemical characteristics of the AMD and its effect on receiving streams, and to identify possible remedial alternatives, the U.S. Geological Survey (USGS) began a study in 2001, in cooperation with the Pennsylvania Department of Environmental Protection and the Schuylkill Conservation District. Aquatic ecological surveys were conducted by the USGS at five stream sites during low base-flow conditions in October 2001. Twenty species of fish were identified in Schwaben Creek near Red Cross, which drains an unmined area of 22.7 square miles (58.8 square kilometers) in the lower part of the Mahanoy Creek Basin. In contrast, 14 species of fish were identified in Mahanoy Creek near its mouth at Kneass, below Schwaben Creek. The diversity and abundance of fish

  11. Social-ecological drivers of multiple ecosystem services: what variables explain patterns of ecosystem services across the Norrström drainage basin?

    Directory of Open Access Journals (Sweden)

    Megan Meacham


    Full Text Available In human dominated landscapes many diverse, and often antagonistic, human activities are intentionally and inadvertently determining the supply of various ecosystem services. Understanding how different social and ecological factors shape the availability of ecosystem services is essential for fair and effective policy and management. In this paper, we evaluate how well alternative social-ecological models of human impact on ecosystems explain patterns of 16 ecosystem services (ES across the 62 municipalities of the Norrström drainage basin in Sweden. We test four models of human impact on ecosystems, land use, ecological modernization, ecological footprint, and location theory, and test their ability to predict both individual ES and bundles of ES. We find that different models do best to predict different types of individual ES. Land use is the best model for predicting provisioning services, standing water quality, biodiversity appreciation, and cross-country skiing, while other models work better for the remaining services. However, this range of models is not able to predict some of the cultural ES. ES bundles are predicted worse than individual ES by these models, but provide a clear picture of variation in multiple ecosystem services based on limited information. Based on our results, we offer suggestions on how social-ecological modeling and assessments of ecosystems can be further developed.

  12. Physical, chemical, and biological data for detailed study of irrigation drainage in the Middle Green River basin, Utah 1988-89, with selected data for 1982-87 (United States)

    Peltz, Lorri A.; Waddell, Bruce


    Physical, chemical, and biological data were collected in the middle Green River basin, eastern Utah, between 1988 and 1989, as part of a detailed study of the effects of irrigation drainage on wetland areas. Data-collection efforts were concentrated in the Stewart Lake Waterfowl Management Area near Jensen, and Ouray National Wildlife Refuge near Ouray. Data also were collected from Ashley Creek near Vernal, Pelican Lake near Ouray, and in Pariette Wetlands near Myton. A limited quantity of data collected during earlier studies (1982-87), funded by the U.S. Fish and Wildlife Service, also is included. This report contains data needed to assess the effects of selenium and other potentially toxic contaminants on streams and wetlands. Data consist of concentrations of trace elements and common elements in samples of water, sediment, plants, waterfowl, birds, fish, and invertebrates. Other data presented in the report are ground-water levels, surface-water discharges, radiochemical constituents in water, analyses of organochlorine compounds in biota, and morphonetric measurements of biota.

  13. Ecologically based targets for bioavailable (reactive) nitrogen discharge from the drainage basins of the Wet Tropics region, Great Barrier Reef. (United States)

    Wooldridge, Scott A; Brodie, Jon E; Kroon, Frederieke J; Turner, Ryan D R


    A modelling framework is developed for the Wet Tropics region of the Great Barrier Reef that links a quantitative river discharge parameter (viz. dissolved inorganic nitrogen concentration, DIN) with an eutrophication indicator within the marine environment (viz. chlorophyll-a concentration, chl-a). The model predicts catchment-specific levels of reduction (%) in end-of-river DIN concentrations (as a proxy for total potentially reactive nitrogen, PRN) needed to ensure compliance with chl-a 'trigger' guidelines for the ecologically distinct, but PRN-related issues of crown-of-thorns starfish (COTS) outbreaks, reef biodiversity loss, and thermal bleaching sensitivity. The results indicate that even for river basins dominated by agricultural land uses, quite modest reductions in end-of-river PRN concentrations (∼20-40%) may assist in mitigating the risk of primary COTS outbreaks from the mid-shelf reefs of the Wet Tropics. However, more significant reductions (∼60-80%) are required to halt and reverse declines in reef biodiversity, and loss of thermal bleaching resistance. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. victoria cross awards warrants concerning the victoria cross (1920)

    African Journals Online (AJOL)

    INTRODUCTION. In the military history of both the British Empire and of the Western World, the highest British military decoration, namely the Victoria Cross, has attained con- siderable renown. The Victoria Cross was introduced in terms of the Royal Warrant of 29 January,. 1856 and by 1957 a total of 1346 had been ...

  15. Role of Lithology and Rock Structure in Drainage Development in ...

    African Journals Online (AJOL)

    Lithology and Rock structure play a vital role in the development of Drainage Network in any drainage basin. The drainage patterns upon land surface develop as directed by the underlying lithology and rock structure. In fact, lithology and rock structure together shape the basin and are decisive parameters of nature and ...

  16. Detailed study of water quality, bottom sediment, and biota associated with irrigation drainage in the Klamath Basin, California and Oregon, 1990-92 (United States)

    Dileanis, P.D.; Schwarzbach, S.E.; Bennett, Jewel


    The effect of irrigation drainage on the water quality and wildlife of the Klamath Basin in California and Oregon was evaluated during 1990-92 as part of the National Irrigation Water Quality Program of the U.S. Department of the Interior. The study focused on land serviced by the Bureau of Reclamation Klamath Project, which supplies irrigation water to agricultural land in the Klamath Basin and the Lost River Basin. The Tule Lake and Lower Klamath National Wildlife Refuges, managed by the U.S. Fish and Wildlife Service, are in the study area. These refuges provide critical resting and breeding habitat for waterfowl on the Pacific flyway and are dependent on irrigation drainwater from upstream agriculture for most of their water supply. Water-quality characteristics throughout the study area were typical of highly eutrophic systems during the summer months of 1991 and 1992. Dissolved-oxygen concentrations and pH tended to fluctuate each day in response to diurnal patterns of photosynthesis, and frequently exceeded criteria for protection of aquatic organisms. Nitrogen and phosphorus concentrations were generally at or above threshold levels characteristic of eutrophic lakes and streams. At most sites the bulk of dissolved nitrogen was organically bound. Elevated ammonia concentrations were common in the study area, especially down- stream of drain inputs. High pH of water increased the toxicity of ammonia, and concentrations exceeded criteria at sites upstream and downstream of irrigated land. Concentrations of ammonia in samples from small drains on the Tule Lake refuge leaseland were higher than those measured in the larger, integrating drains at primary monitoring sites. The mean ammonia concentration in leaseland drains [1.21 milligrams per liter (mg/L)] was significantly higher than the mean concentration in canals delivering water to the leaseland fields (0.065 mg/L) and higher than concentrations reported to be lethal to Daphnia magna (median lethal

  17. Refinement of regression models to estimate real-time concentrations of contaminants in the Menomonee River drainage basin, southeast Wisconsin, 2008-11 (United States)

    Baldwin, Austin K.; Robertson, Dale M.; Saad, David A.; Magruder, Christopher


    In 2008, the U.S. Geological Survey and the Milwaukee Metropolitan Sewerage District initiated a study to develop regression models to estimate real-time concentrations and loads of chloride, suspended solids, phosphorus, and bacteria in streams near Milwaukee, Wisconsin. To collect monitoring data for calibration of models, water-quality sensors and automated samplers were installed at six sites in the Menomonee River drainage basin. The sensors continuously measured four potential explanatory variables: water temperature, specific conductance, dissolved oxygen, and turbidity. Discrete water-quality samples were collected and analyzed for five response variables: chloride, total suspended solids, total phosphorus, Escherichia coli bacteria, and fecal coliform bacteria. Using the first year of data, regression models were developed to continuously estimate the response variables on the basis of the continuously measured explanatory variables. Those models were published in a previous report. In this report, those models are refined using 2 years of additional data, and the relative improvement in model predictability is discussed. In addition, a set of regression models is presented for a new site in the Menomonee River Basin, Underwood Creek at Wauwatosa. The refined models use the same explanatory variables as the original models. The chloride models all used specific conductance as the explanatory variable, except for the model for the Little Menomonee River near Freistadt, which used both specific conductance and turbidity. Total suspended solids and total phosphorus models used turbidity as the only explanatory variable, and bacteria models used water temperature and turbidity as explanatory variables. An analysis of covariance (ANCOVA), used to compare the coefficients in the original models to those in the refined models calibrated using all of the data, showed that only 3 of the 25 original models changed significantly. Root-mean-squared errors (RMSEs

  18. Impact of Drainage Basin Geology and Geomorphology on Detrital Thermochronometric Data from Modern River Sands: A Case Study in the Bhutan Himalaya (United States)

    Coutand, I.; Whipp, D. M., Jr.; Bookhagen, B.; Grujic, D.


    Detrital thermochronology has become an important tool to quantify the erosional history of mountainous regions. Despite an increasing number of studies utilizing detrital records, it remains unclear how the record of spatially variable erosion of upstream drainage basins is preserved in the thermochronologic signal contained in the sediments. This important spatiotemporal problem is a first-order unknown that limits the interpretation of the geological significance of the detrital signal. To improve our understanding of detrital records in terms of spatiotemporal erosion rates, we use a three-step approach to study modern fluvial sediments from the Bhutan Himalaya. First, based on a preferred tectonomorphic scenario extracted by inversion of in situ multi-thermochronological ages, we predict apatite fission-track (AFT) age distributions in 18 catchments using the Pecube software. Second, we compare AFT age distributions from modern sand bars collected at each catchment outlet to distributions extracted from Monte Carlo sampling of the predicted catchment ages. We find that observed and predicted age distributions are statistically equivalent for only ~75% of the catchments. Third, we calculate predicted detrital age distributions by scaling the prevalence of ages in the catchment in proportion to topographic and climatic metrics (e.g., local relief, steepness index, specific stream power weighted by precipitation rate) or landslide-driven erosion to quantify their effects and relationships to the observed detrital AFT age distributions. Preliminary results suggest erosion in proportion to the topographic metrics cannot reproduce the observed age distributions, but bedrock landsliding may provide sufficient age variability to reproduce the observations. Ongoing work is determining whether variable target mineral concentrations in bedrock geological units or non-uniform sediment sourcing from moraine- or glacier-covered regions can reproduce the observed ages.

  19. GIS and MCDM analysis to evaluate and zoning of soil erosion in Junaghan drainage sub-basin in Karun , SW-Iran (United States)

    Rezaei, Khalil; Yavari, Shahla; Khodabakhsh, Saeid; Mohseni, Hasan; Bozorgzadeh, Eisa


    Problems involving the processing of spatial data such as soil erosion are multi-facetted challenges. Recently, absolute determination of sediment production with using quality and quantity data of drainage basins is one of the most important factors in soil protection management. In this research, we use MPSIAC method for calculating of annually sediment production and then we compare results with other methods. Results showed 21.93% difference with field observations. As there are many agents affecting on erosion and they depend on geographical location, soil, topography, climate, land use, geology and hydrology of selected area, solutions for these problems involve highly complex spatial data analysis processes and frequently require advanced means to address physical suitability conditions, while considering the multiple ecological and geological variables. Geographic Information Systems (GIS) and Multi-Criteria Decision-Making techniques (MCDM) are two common tools employed to solve these problems. However, each suffers from serious shortcomings. GIS, which deals mainly with physical suitability analysis, has very limited capability of incorporating the decision maker's preferences into the problem solving process. MCDM, which deals mainly with analyzing decision problems and evaluating the alternatives based on a decision maker's values and preferences, lacks the capability of handling spatial data (e. g., buffering and overlay) that are crucial to spatial analysis. The need for combining the strengths of these two techniques has prompted researchers to seek integration of GIS and MCDM. Also, in this research, MCDM methods have been integrated with a GIS to provide a map for soil erosion based upon a variety of different choice criteria (agent) and on the importance (weight) a decision maker might attach to these. This integration could benefit environmental, soil and water planners and decision makers. Key words: soil erosion, MPSIAC, GIS, MCDM.

  20. Reconnaissance investigation of water quality, bottom sediment, and biota associated with irrigation drainage in the middle Green River basin, Utah, 1986-87 (United States)

    Stephens, D.W.; Waddell, Bruce; Miller, J.B.


    Reconnaissance of wildlife areas in the middle Green River basin of Utah was conducted during 1986 and 1987 to determine whether irrigation drainage has caused, or has the potential to cause significant harmful effects on human health, fish, and wildlife, or may adversely affect the suitability of water for beneficial uses. Studies at Stewart Lake Waterfowl Management Area and Ouray National Wildlife Refuge indicated that concentrations of boron, selenium, and zinc in water, bottom sediment, and biological tissue were sufficiently large to be harmful to fish and wildlife, and to adversely affect beneficial uses of water. Selenium is the principal element of concern in both areas. Concentrations of dissolved selenium in irrigation drain water entering Stewart Lake Waterfowl Management Area ranged from 14-140 micrograms/L (ug/L) and consistently exceeded Utah standards for wildlife protection in water in two of the four drains. Concentrations of boron and zinc exceeded Utah standards only occasionally in the drain waters. Concentrations of total selenium in sediments collected where the drains discharge into the lake were 10-85 ug/gm. Liver tissue collected from American coots at Stewart Lake Waterfowl Management Area contained concentrations of selenium from 4.9-26 ug/gm (dry weight), and whole body samples of carp contained as much as 31 ug/gm (dry weight). Concentrations of selenium in Potamogeton and blue-green algae ranged from 2.1-27 ug/gm. Concentrations of boron, selenium, and zinc were also measured in water from Ouray National Wildlife Refuge. Liver tissue of American coots from the North Roadside Pond, which receives irrigation tailwater, contained a geometric-mean concentration of selenium of 32 ug/gm (dry weight). Five water-bird eggs collected from the North and South Roadside Ponds contained selenium concentrations of 63-120 ug/gm (dry weight). (Lantz-PTT)

  1. within the lake victoria basin, tanzania

    African Journals Online (AJOL)

    Appropriate pollution control measures should be taken though levels encountered are still within those recommended in the Tanzania Water Utilization (Control and Regulation). Amendment Act of1981 for receiving waters. ..... these vulnerable water bodies. ACKNOWLEDGEMENTS. The author would like to thank the ...

  2. [The epilepsy of Guadalupe Victoria]. (United States)

    Soto-Pérez-de-Celis, Enrique


    Guadalupe Victoria, the first President of Mexico, passed away in 1843 uictim of an ailment that, at the time, was diagnosed as epilepsy. The clinical data and the pathologic findings, however, suggest the possibility that Victoria had an underlying disease that was responsible for the seizures that affected him. In this article I propose that Guadalupe Victoria had in fact Chagas Disease, and that he was infected with this parasitic malady while he lived in the tropical jungles of Veracruz, in eastern Mexico. Even though there aren't many published works regarding seizures secondary to chronic Chagas Disease, there are good descriptions of epileptic syndromes in patients with this infection. At the same time, the cardiac findings in Victoria's autopsy support the idea that he had some kind of cardiac pathology; in this case Chagasic dilated cardiomyopathy, which ultimately led to his death.

  3. VICTORIA'S SECRET Prepares for Growth

    National Research Council Canada - National Science Library

    Jordan K Speer


      After the upcoming holiday season, Victoria's Secret will take the first steps toward launching its e-commerce business on a cross-channel on-demand platform from partner n2N Commerce, a company...

  4. Effects of Abandoned Coal-Mine Drainage on Streamflow and Water Quality in the Shamokin Creek Basin, Northumberland and Columbia Counties, Pennsylvania, 1999-2001 (United States)

    Cravotta, Charles A.; Kirby, Carl S.


    This report assesses the contaminant loading, effects to receiving streams, and possible remedial alternatives for abandoned mine drainage (AMD) within the upper Shamokin Creek Basin in east-central Pennsylvania. The upper Shamokin Creek Basin encompasses an area of 54 square miles (140 square kilometers) within the Western Middle Anthracite Field, including and upstream of the city of Shamokin. Elevated concentrations of acidity, metals, and sulfate in the AMD from flooded underground anthracite coal mines and (or) unreclaimed culm (waste rock) piles degrade the aquatic ecosystem and water quality of Shamokin Creek to its mouth and along many of its tributaries within the upper basin. Despite dilution by unpolluted streams that more than doubles the streamflow of Shamokin Creek in the lower basin, AMD contamination and ecological impairment persist to its mouth on the Susquehanna River at Sunbury, 20 miles (32 kilometers) downstream from the mined area. Aquatic ecological surveys were conducted by the U.S. Geological Survey (USGS) in cooperation with Bucknell University (BU) and the Northumberland County Conservation District (NCCD) at six stream sites in October 1999 and repeated in 2000 and 2001 on Shamokin Creek below Shamokin and at Sunbury. In 1999, fish were absent from Quaker Run and Shamokin Creek upstream of its confluence with Carbon Run; however, creek chub (Semotilus atromaculatus) were present within three sampled reaches of Carbon Run. During 1999, 2000, and 2001, six or more species of fish were identified in Shamokin Creek below Shamokin and at Sunbury despite elevated concentrations of dissolved iron and ironencrusted streambeds at these sites. Data on the flow rate and chemistry for 46 AMD sources and 22 stream sites throughout the upper basin plus 1 stream site at Sunbury were collected by the USGS with assistance from BU and the Shamokin Creek Restoration Alliance (SCRA) during low base-flow conditions in August 1999 and high baseflow

  5. Water-quality assessment of the Albemarle-Pamlico drainage basin, North Carolina and Virginia; trace elements in Asiatic clam (Corbicula fluminea) soft tissues and redbreast sunfish (Lepomis auritus) livers, 1992-93 (United States)

    Ruhl, P.M.; Smith, K.E.


    The analysis of potential contaminants in biological tissues is an important part of many water-quality assessment programs, including the National Water-Quality Assessment (NAWQA) Program. Tissue analyses often are used to provide information about (1) direct threats to ecosystem integrity, and (2) the occurrence and distribution of potential contaminants in the environment. During 1992-93, trace elements in Asiatic clam (Corbicula fluminea) soft tissues and redbreast sunfish (Lepomis auritus) livers were analyzed to obtain information about the occurrence and distribution of trace element contaminants in the Albemarle-Pamlico Drainage Basin of North Carolina and Virginia. The investigation was conducted as part of the NAWQA Program. All but 3 of the 22 trace elements that were analyzed were detected. Although all 10 of the U.S. Environmental Protection Agency (U.S. EPA) priority pollutants were detected in the tissues sampled, they were present in relatively low concentrations. Concentrations of U.S. EPA priority pollutants in Asiatic clams collected in the Albemarle-Pamlico Drainage Basin are similar to concentrations observed in other NAWQA study units in the southeastern United States. Mercury (a U.S. EPA priority pollutant) was widely detected, being present in 29 of 30 tissue samples, but concentrations did not exceed the FDA action level for mercury of a risk-based screening value for the general public. Mercury concentrations in Asiatic clams were similar to concentrations in other NAWQA study areas in the Southeast.

  6. Natural factors and mining activity bearings on the water quality of the Choapa basin, North Central Chile: insights on the role of mafic volcanic rocks in the buffering of the acid drainage process. (United States)

    Parra, Amparo; Oyarzún, Jorge; Maturana, Hugo; Kretschmer, Nicole; Meza, Francisco; Oyarzún, Ricardo


    This contribution analyzes water chemical data for the Choapa basin, North Central Chile, for the period 1980-2004. The parameters considered are As, Cu Fe, pH, EC, SO₄⁻², Cl⁻¹, and HCO[Formula: see text], from samples taken in nine monitoring stations throughout the basin. Results show rather moderate contents of As, Cu, and Fe, with the exception of the Cuncumén River and the Aucó creek, explained by the influence of the huge porphyry copper deposit of Los Pelambres and by the presence of mining operations, respectively. When compared against results obtained in previous researches at the neighboring Elqui river basin, which host the El Indio Au-Cu-As district, a much reduced grade of pollution is recognized for the Choapa basin. Considering the effect of acid rock drainage (ARD)-related Cu contents on the fine fraction of the sediments of both river basins, the differences recorded are even more striking. Although the Los Pelambres porphyry copper deposit, on the headwaters of the Choapa river basin, is between one and two orders of magnitude bigger than El Indio, stream water and sediments of the former exhibit significantly lower copper contents than those of the latter. A main factor which may explain these results is the smaller degree of H( + )-metasomatism on the host rocks of the Los Pelambres deposit, where mafic andesitic volcanic rocks presenting propylitic hydrothermal alteration are dominant. This fact contrast with the highly altered host rocks of El Indio district, where most of them have lost their potential to neutralize ARD.

  7. Forest drainage (United States)

    R.W. Skaggs; S. Tian; G.M. Chescheir; Devendra Amatya; M.A. Youssef


    Most of the world's 4030 million ha of forested lands are situated on hilly, mountainous or well-drained upland landscapes where improved drainage is not needed. However, there are millions of hectares of poorly drained forested lands where excessively wet soil conditions limit tree growth and access for harvesting and other management activities. Improved or...

  8. Subsurface drainage

    CSIR Research Space (South Africa)

    Van Der Merwe, CJ


    Full Text Available and long term behavior were evaluated. Laboratory tests for geotextile selection are recommended and tentative criteria given. The use of fin drains was evaluated in the laboratory and a field study to monitor the efficacy of drainage systems was started...

  9. Exceedance probability map: a tool helping the definition of arsenic Natural Background Level (NBL) within the Drainage Basin to the Venice Lagoon (NE Italy) (United States)

    Dalla Libera, Nico; Fabbri, Paolo; Mason, Leonardo; Piccinini, Leonardo; Pola, Marco


    Arsenic groundwater contamination affects worldwide shallower groundwater bodies. Starting from the actual knowledges around arsenic origin into groundwater, we know that the major part of dissolved arsenic is naturally occurring through the dissolution of As-bearing minerals and ores. Several studies on the shallow aquifers of both the regional Venetian Plain (NE Italy) and the local Drainage Basin to the Venice Lagoon (DBVL) show local high arsenic concentration related to peculiar geochemical conditions, which drive arsenic mobilization. The uncertainty of arsenic spatial distribution makes difficult both the evaluation of the processes involved in arsenic mobilization and the stakeholders' decision about environmental management. Considering the latter aspect, the present study treats the problem of the Natural Background Level (NBL) definition as the threshold discriminating the natural contamination from the anthropogenic pollution. Actually, the UE's Directive 2006/118/EC suggests the procedures and criteria to set up the water quality standards guaranteeing a healthy status and reversing any contamination trends. In addition, the UE's BRIDGE project proposes some criteria, based on the 90th percentile of the contaminant's concentrations dataset, to estimate the NBL. Nevertheless, these methods provides just a statistical NBL for the whole area without considering the spatial variation of the contaminant's concentration. In this sense, we would reinforce the NBL concept using a geostatistical approach, which is able to give some detailed information about the distribution of arsenic concentrations and unveiling zones with high concentrations referred to the Italian drinking water standard (IDWS = 10 µg/liter). Once obtained the spatial information about arsenic distribution, we can apply the 90th percentile methods to estimate some Local NBL referring to every zones with arsenic higher than IDWS. The indicator kriging method was considered because it

  10. Hydro-climatic trends and water resource management implications based on multi-scale data for the Lake Victoria region, Kenya (United States)

    Koutsouris, A. J.; Destouni, G.; Jarsjö, J.; Lyon, S. W.


    Unreliable rainfall may be a main cause of poverty in rural areas, such as the Kisumu district by Lake Victoria in Kenya. Climate change may further increase the negative effects of rainfall uncertainty. These effects could be mitigated to some extent through improved and adaptive water resource management and planning, which relies on our interpretations and projections of the coupled hydro-climatic system behaviour and its development trends. In order to identify and quantify the main differences and consistencies among such hydro-climatic assessments, this study investigates trends and exemplifies their use for important water management decisions for the Lake Victoria drainage basin (LVDB), based on local scale data for the Orongo village in the Kisumu district, and regional scale data for the whole LVDB. Results show low correlation between locally and regionally observed hydro-climatic trends, and large differences, which in turn affects assessments of important water resource management parameters. However, both data scales converge in indicating that observed local and regional hydrological discharge trends are primarily driven by local and regional water use and land use changes.

  11. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: Artificial Drainage (1992) and Irrigation (1997) (United States)

    U.S. Geological Survey, Department of the Interior — This tabular data set represents the estimated area of artifical drainage for the year 1992 and irrigation types for the year 1997 compiled for every MRB_E2RF1...

  12. Questa baseline and pre-mining ground-water quality investigation. 5. Well installation, water-level data, and surface- and ground-water geochemistry in the Straight Creek drainage basin, Red River Valley, New Mexico, 2001-03 (United States)

    Naus, Cheryl A.; McCleskey, R. Blaine; Nordstrom, D. Kirk; Donohoe, Lisa C.; Hunt, Andrew G.; Paillet, Frederick L.; Morin, Roger H.; Verplanck, Philip L.


    The U.S. Geological Survey, in cooperation with the New Mexico Environment Department, is investigating the pre-mining ground-water chemistry at the Molycorp molybdenum mine in the Red River Valley, northern New Mexico. The primary approach is to determine the processes controlling ground-water chemistry at an unmined, off-site, proximal analog. The Straight Creek drainage basin, chosen for this purpose, consists of the same quartz-sericite-pyrite altered andesitic and rhyolitic volcanic rock of Tertiary age as the mine site. The weathered and rugged volcanic bedrock surface is overlain by heterogeneous debris-flow deposits that interfinger with alluvial deposits near the confluence of Straight Creek and the Red River. Pyritized rock in the upper part of the drainage basin is the source of acid rock drainage (pH 2.8-3.3) that infiltrates debris-flow deposits containing acidic ground water (pH 3.0-4.0) and bedrock containing water of circumneutral pH values (5.6-7.7). Eleven observation wells were installed in the Straight Creek drainage basin. The wells were completed in debris-flow deposits, bedrock, and interfingering debris-flow and Red River alluvial deposits. Chemical analyses of ground water from these wells, combined with chemical analyses of surface water, water-level data, and lithologic and geophysical logs, provided information used to develop an understanding of the processes contributing to the chemistry of ground water in the Straight Creek drainage basin. Surface- and ground-water samples were routinely collected for determination of total major cations and selected trace metals; dissolved major cations, selected trace metals, and rare-earth elements; anions and alkalinity; and dissolved-iron species. Rare-earth elements were determined on selected samples only. Samples were collected for determination of dissolved organic carbon, mercury, sulfur isotopic composition (34S and 18O of sulfate), and water isotopic composition (2H and 18O) during

  13. Special Issue on Lake Victoria

    African Journals Online (AJOL)

    The diversity of benthic mollusks of Lake Victoria and Lake Burigi · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. JA Mwambungu, 21-32. ...

  14. Drainage-area boundaries for selected sampling stations, scale 1:100,000, Yellowstone River Basin, Montana, North Dakota, and Wyoming (United States)

    U.S. Geological Survey, Department of the Interior — As part of the U.S. Geological Survey's National Water-Quality Assessment Program, an investigation of the Yellowstone River Basin study unit is being conducted to...

  15. Application of the groundwater-balance equation to indicate interbasin and vertical flow in two semi-arid drainage basins, Mexico (United States)

    Carrillo-Rivera, J. J.


    An analysis of horizontal inflow and outflow in the groundwater-budget equation and the significance for interbasin flow are presented. Two field cases in Mexico, one in the Baja California peninsula and another in central Mexico, highlight the influence of interbasin flow. A significant proportion (approximately 70%) of the ed (thermal) groundwater probably originates outside the drainage basin. A conclusion is that a groundwater-balance study is an unsatisfactory method for determining some parameters, such as storativity (S). Specifically, the groundwater-balance approach provides unreliable results when vertical inflow is ignored or cannot be adequately defined. Vertical flow is indicated by the presence of groundwater temperatures as much as 23 °C higher than ambient temperature. Regional faults could be the pathways for upward flow. When vertical inflow is ignored, uncertainty in the estimation of the storativity through regional groundwater-balance calculation results. On the basis of the groundwater-balance equation, a value of S=0.19 appears to represent the confined condition of the developed part of the aquifer; this result is several orders of magnitude higher than would be reasonable according to the geological conditions. Findings are useful in evaluating whether a groundwater resource is being "overexploited". Conclusions are instructive in the application of transient-flow computer models, in which vertical flow of less dense water from beneath is not included. Résumé. L'article présente une analyse des entrées et des sorties horizontales dans l'équation du bilan d'une nappe et leur signification dans les écoulements entre bassins. Deux exemples provenant du Mexique, l'un dans la péninsule de Basse Californie, l'autre dans le centre du Mexique, mettent en lumière l'influence de l'écoulement entre bassins, où une proportion significative (environ 70%) de l'eau souterraine extraite, thermale, a probablement son origine hors du bassin. Une

  16. Reconnaissance of the chemical quality of water in western Utah, Part I: Sink Valley area, drainage basins of Skull, Rush, and Government Creek Valleys, and the Dugway Valley-Old River Bed area (United States)

    Waddell, K.M.


    This report presents data collected during the first part of an investigation that was started in 1963 by the U.S. Geological Survey in cooperation with the Utah Geological and Mineralogical Survey. The investigation has the purpose of providing information about the chemical quality of water in western Utah that will help interested parties to evaluate the suitability of the water for various uses in a broad area of Utah where little information of this type previously has been available. The area studied includes the Sink Valley area, the drainage basins of Skull, Rush, and Government Creek Valleys, and the Dugway Valley-Old River Bed area (fig. 1). Osamu Hattori and G. L. Hewitt started the investigation, and the author completed it and prepared the report.

  17. Mapping of a Hydrological Ice Sheet Drainage Basin on the West Greenland Ice Sheet Margin from ERS-1/2 SAR Interferometry, Ice-Radar Measurement, and Modelling

    DEFF Research Database (Denmark)

    Ahlstrøm, Andreas P.; Bøggild, C.E.; Stenseng, L.


    importance of the potential of the ice overburden pressure compared to the bedrock topography. The meltwater run-off for the basin delineations was modelled with an energy-balance model calibrated with observed ice-sheet ablation and compared to a 25 year time series of measured basin run-off. The standard......The hydrological ice-sheet basin draining into the Tasersiaq lake, West Greenland (66°13'N, 50°30'W), was delineated, First using standard digital elevation models (DEMs) for ice-sheet surface and bedrock, and subsequently using a new high-resolution dataset, with a surface DEM derived from repeat......-track interferometric synthetic aperture radar (SAR) and a bedrock topography derived from an airborne 60 MHz ice-penetrating radar. The extent of the delineation was calculated from a water-pressure potential as a function of the ice-sheet surface and bedrock elevations and a hydraulic factor κ describing the relative...

  18. Environmental status of the Lake Michigan region. Volume II. Natural areas of the Lake Michigan drainage basin and endangered or threatened plant and animal species

    Energy Technology Data Exchange (ETDEWEB)

    Stearns, F.; Lindsley, D.


    The accelerating encroachment of human activity on the natural landscape has made many citizens appreciate the need to save representative biotic communities before urbanization and technologically induced change eliminate such communities. Active programs in natural-area preservation are now in progress in the four basin states; these programs have strong public support and legislative mandate. Local, state, and federal agencies and private individuals have taken an active interest in protecting select areas as samples of the biotic communities and natural features of the Basin. Most natural areas described in this report have been dedicated or reserved in some fashion. Other areas are being added by the basin states each year. The maintenance of natural communities is closely linked to the preservation of endangered and threatened species of plants and animals which would cease to survive as isolated populations. Under federal regulations, certain plants and animals are listed as endangered or threatened in the Basin. As individual state lists are prepared and investigations proceed, it is probable that many more threatened species will be found.

  19. Environmental Status of the Lake Michigan Region Volume 11. Natural Areas of the Lake Michigan Drainage Basin and Endangered or Threatened Plant and Animal Species

    Energy Technology Data Exchange (ETDEWEB)

    Stearns, Forest [Argonne National Lab. (ANL), Argonne, IL (United States); Lindsley, Diane [Argonne National Lab. (ANL), Argonne, IL (United States)


    The accelerating encroachment of human activity on the natural landscape has made many citizens appreciate the need to save representative biotic communities before urbanization and technologically induced change eliminate such communities. Active programs in natural-area preservation now in progress in the four basin states; these programs have strong public support and legislative mandate. Local, state, and federal agencies and private individuals have taken an active interest in protecting select areas as samples of the biotic communities and natural features of the Basin. Most natural areas described in this report have been dedicated or reserved in some fashion. Other areas are being added by the basin states each year. The maintenance of natural communities is closely linked to the preservation of endangered and threatened species of plants and animals which would cease to survive as isolated populations. Under federal regulations, certain plants and animals are listed as endange~ ed or threatened in the Basin. As individual state lists are prepared and investigations proceed, it is probable that many more threatened species will be found.

  20. Structural and Hydrologic Implications of Joint Orientations in the Warner Creek and Stony Clove Drainage Basins, Catskill Mountains, Eastern New York (United States)

    Haskins, M. N.; Vollmer, F. W.; Rayburn, J. A.; Gurdak, J. J.


    To investigate joint control on hydrology as well as tectonic implications, we conducted a study of joint orientations near the Stony Clove and Warner Creek drainages of the Catskill Mountains, Eastern New York. Specific goals of this research were to determine joint control on stream orientations and groundwater flow, to compare results with previous studies in the area, and to investigate their tectonic significance. Trails, streams, and road cuts were traversed to locate bedrock outcrops whose positions were determined using topographic maps and a handheld GPS unit. Additional outcrops were located using aerial photographs and GIS data. Joint orientations were measured using a standard Brunton pocket transit. The data was analyzed using Orient (Vollmer, 2010), an orientation analysis program, to plot joint and stream orientations on rose diagrams. ArcGIS was used to produce topographic, hill-shade, and stream drainage maps. Over 500 joint orientations at over 100 outcrop stations were collected. The data were plotted on a rose diagrams, and two major joint sets were found, one with a mean strike of 021° and one with a mean strike of 096°. Stream orientations were also plotted on a rose diagram showing an axial mean of 022°, and indicate that the joint set with mean strike of 021 may have a significant control on stream orientations. The hill-shade maps also demonstrate clearly the strong control of jointing on the topography. The data collected in this research expands on previous joint orientation studies of Engelder and Geiser (1980) in the southwestern and central Catskills, and is similar to joint orientations found by Isachsen et al. (1977) in their study of the Panther Mountain circular structure, a possible impact-related feature. The origin of this jointing is thought to be related to Alleghanian (Permian) and possibly Acadian (Devonian) orogenic events.

  1. Impact of AMD on water quality in critical watershed in the Hudson River drainage basin: Phillips Mine, Hudson Highlands, New York (United States)

    Gilchrist, S.; Gates, A.; Szabo, Z.; Lamothe, P.J.


    A sulfur and trace element enriched U-Th-laced tailings pile at the abandoned Phillips Mine in Garrison, New York, releases acid mine drainage (AMD, generally pH Copper Mine Brook (CMB) that drains into the Hudson River. The pyrrhotite-rich Phillips Mine is located in the Highlands region, a critical water source for the New York metro area. A conceptual model for derivation/dissolution, sequestration, transport and dilution of contaminants is proposed. The acidic water interacts with the tailings, leaching and dissolving the trace metals. AMD evaporation during dry periods concentrates solid phase trace metals and sulfate, forming melanterite (FeSO4.7H2O) on sulfide-rich tailings surfaces. Wet periods dissolve these concentrates/precipitates, releasing stored acidity and trace metals into the CMB. Sediments along CMB are enriched in iron hydroxides which act as sinks for metals, indicating progressive sequestration that correlates with dilution and sharp rise in pH when mine water mixes with tributaries. Seasonal variations in metal concentrations were partly attributable to dissolution of the efflorescent salts with their sorbed metals and additional metals from surging acidic seepage induced by precipitation.

  2. Water-quality assessment of the Albemarle-Pamlico Drainage Basin, North Carolina and Virginia; organochlorine compounds in Asiatic clam (Corbicula fluminea) soft tissues and whole redbrest sunfish (Lepomis auritus) 1992-93 (United States)

    Smith, K.E.; Ruhl, P.M.


    The analysis of potential contaminants in biological tissues is an important part of many water-quality assessment programs, including the National Water-Quality Assessment (NAWQA) Program. Tissue analyses often are used to provide information about (1) direct threats to ecosystem integrity, and (2) the occurrence and distribution of potential contaminants in the environment. During 1992-93, Asiatic clam (Corbicula fluminea) soft tissues and whole redbreast sunfish (Lepomis auritus) samples were collected and analyzed to obtain information about the occurrence and distribution of organochlorine compounds in the Albemarle-Pamlico drainage Basin of North Carolina and Virginia. The investigation was conducted as part of the NAWQA Program. Relatively few organochlorine compounds were detected and of the compounds detected, all were detected in relatively low concentrations. The organochlorine compounds detected were p,p'-DDD, p,p'-DDE, p,p'-DDT, dieldrin, trans-nonachlor, PCB's, and toxaphene. Multiple compounds were detected at 16 of 19 sites sampled. Compared to Asiatic clams, redbreast sunfish appear to be better bioindicators of organochlorine contamination in aquatic systems. Except for one detection of toxaphene, pesticide concentrations are well below the National Academy of Sciences and National Academy of Engineering (NAS/NAE) guidelines for the protection of fish-eating wildlife.

  3. Biology of black bass Micropterus salmoides (Lacepède, 1802 fifty years after the introduction in a small drainage of the Upper Paraná River basin, Brazil

    Directory of Open Access Journals (Sweden)



    Full Text Available Garcia DAZ, Costa ADA, Leme GLA, Orsi ML. 2014. Biology of black bass Micropterus salmoides (Lacepède, 1802 fifty years after the introduction in a small drainage of the Upper Paraná River basin, Brazil. Biodiversitas 15: 180-185. The dispersion of organisms by human actions has been the major source of changes in the natural distribution of species, making the introduction of non-native species a threat to biological diversity. Micropterus salmoides is a fish originating from North America, which was introduced in a lagoon in the Ecological Park of Fazenda Monte Alegre in southern Brazil over 50 years ago. The reproductive activity, weight-length relationship and relative condition factor were analyzed to evaluate the health parameters of the species. The result allows us to classify the reproductive activity of this population as moderate. It was found that the health condition patterns are identical to those theoretically expected. The occurrence of individuals downstream of the lagoon shows that the population has been presenting dispersion conditions to new environments, posing a threat to local biodiversity. Management measures, such as isolation or eradication of the population, are required to control the species within the studied site, and prevent its dispersion into natural watercourses.

  4. In situ measurements of microbially-catalyzed nitrification and nitrate reduction rates in an ephemeral drainage channel receiving water from coalbed natural gas discharge, Powder River Basin, Wyoming, USA (United States)

    Harris, S.H.; Smith, R.L.


    Nitrification and nitrate reduction were examined in an ephemeral drainage channel receiving discharge from coalbed natural gas (CBNG) production wells in the Powder River Basin, Wyoming. CBNG co-produced water typically contains dissolved inorganic nitrogen (DIN), primarily as ammonium. In this study, a substantial portion of discharged ammonium was oxidized within 50??m of downstream transport, but speciation was markedly influenced by diel fluctuations in dissolved oxygen (> 300????M). After 300??m of transport, 60% of the initial DIN load had been removed. The effect of benthic nitrogen-cycling processes on stream water chemistry was assessed at 2 locations within the stream channel using acrylic chambers to conduct short-term (2-6??h), in-stream incubations. The highest ambient DIN removal rates (2103????mol N m- 2 h- 1) were found at a location where ammonium concentrations > 350????M. This occurred during light incubations when oxygen concentrations were highest. Nitrification was occurring at the site, however, net accumulation of nitrate and nitrite accounted for nitrification was not a factor and changes in DIN removal rates were controlled by nitrate reduction, diel fluctuations in oxygen concentration, and availability of electron donor. This study indicates that short-term adaptation of stream channel processes can be effective for removing CBNG DIN loads given sufficient travel distances, but the long-term potential for nitrogen remobilization and nitrogen saturation remain to be determined.

  5. Strike slip faulting inferred from offsetting of drainages: Lower ...

    Indian Academy of Sciences (India)

    The detailed analysis of landforms, drainages and geology of the area between the rivers Amaravati and Karjan was carried out in order to understand the tectonic history of the lower Narmada basin. Movement along the various faults in the area was studied on the basis of the drainage offsetting. Horizontal offsetting of ...

  6. Stormwater Drainage Wells (United States)

    Provides information for identifying stormwater drainage wells, learn how to comply with regulations for storm water drainage wells, and how to reduce the threat to ground water from stormwater injection wells.

  7. Spiraal : uus Victoria & Alberti muuseum Londonis

    Index Scriptorium Estoniae


    Daniel Libeskindi projekt Victoria & Alberti Muuseumi laiendamiseks on põhjustanud konservatiivsete londonlaste pahameele, kuid kutsunud esile ka hulgaliselt toetusavaldusi. Muuseumi uus osa (kokkuvarisemise piiril näiva ehitisena) peaks külastajaile avatama 2004. a.

  8. The Amazon at sea: Onset and stages of the Amazon River from a marine record, with special reference to Neogene plant turnover in the drainage basin (United States)

    Hoorn, Carina; Bogotá-A, Giovanni R.; Romero-Baez, Millerlandy; Lammertsma, Emmy I.; Flantua, Suzette G. A.; Dantas, Elton L.; Dino, Rodolfo; do Carmo, Dermeval A.; Chemale, Farid


    The Amazon submarine fan is a large sediment apron situated offshore Pará (Brazil) and represents the most distal extent of the Amazon River. The age of onset of this transcontinental river remains debated, yet is of great importance for understanding biotic evolutionary processes on land and at sea. Here we present new geochemical and palynological data from a borehole drilled at the continental slope and dated based on nannofossil biostratigraphy. We found that sediments of mixed source (craton and adjacent) occur at least from the late Oligocene (NP25) to late Miocene (NN9), and that the earliest Andes-derived sediments occur in NN10 (late Miocene). Our geochemical record indicates an onset of the transcontinental Amazon River between 9.4 and 9 Ma, which postdates the regional unconformity by 1 to 1.5 My. The shift in sediment geochemistry is more gradually replicated in the palynological record by a change from coastal plain and tropical lowland taxa to a mixture of tropical lowland, and montane forest to open Andean taxa. In particular, the appearance of taxa such as Jamesonia and Huperzia, followed by Valeriana, Polylepis-Acaena, Lysipomia and Plantago (with a current altitudinal range from 3200 to 4000 m) suggests the development of open, treeless, vegetation between 9.5 and 5.4 Ma, and highlight the presence of a high Andes in the late Miocene hinterland. Poaceae progressively increased from 9 Ma, with a notable rise from 4 Ma onwards, and percentages well above post-glacial and modern values, particularly between 2.6 and 0.8 Ma. We hypothesize that the rise of the grasses is a basin-wide phenomenon, but that the Plio-Pleistocene expansion of open, treeless vegetation on the Andean slopes and foothills are the main contributor. This rise in grasses was likely caused by climatic fluctuations, and subsequent changes in relief and erosion rates. We conclude that the onset of the Amazon River is coupled with Neogene Andean tectonism and that subsequent

  9. Transient drainage summary report

    Energy Technology Data Exchange (ETDEWEB)



    This report summarizes the history of transient drainage issues on the Uranium Mill Tailings Remedial Action (UMTRA) Project. It defines and describes the UMTRA Project disposal cell transient drainage process and chronicles UMTRA Project treatment of the transient drainage phenomenon. Section 4.0 includes a conceptual cross section of each UMTRA Project disposal site and summarizes design and construction information, the ground water protection strategy, and the potential for transient drainage.

  10. Impacts of changing water price and availability on irrigated dairy farms in northern Victoria


    Ho, Christie K.M.; Armstrong, Dan P.; Doyle, Peter T.; Malcolm, Bill


    Farming systems throughout the Murray-Darling Basin are under increasing scrutiny from the perspective of ecological sustainability of farm and catchment systems. In northern Victoria, the dairy industry is a major user of water, and contributes to the environmental issues. Changes in irrigation water price, availability and policy will invariably impact on the viability of dairy farming in this region, but the diversity of dairy farm systems suggests that the impact will vary between farms. ...

  11. The Victoria Project, Sri Lanka: Victoria Power-Station. [Hydroelectric power

    Energy Technology Data Exchange (ETDEWEB)

    Creber, B. (Sir Alexander Gibb and Partners (GB))


    The Victoria Hydroelectric Power-Station forms part of the Victoria Project on the Mahaweli Ganga in Sri Lanka and it provides the country's largest single power source. The Paper describes the planning, design and construction of the civil engineering works, including problems encountered, and also describes, in outline, the electrical and mechanical works. (Author).

  12. Inventory of drainage wells and potential sources of contaminants to drainage-well inflow in Southwest Orlando, Orange County, Florida (United States)

    Taylor, George Fred


    Potential sources of contaminants that could pose a threat to drainage-well inflow and to water in the Floridan aquifer system in southwest Orlando, Florida, were studied between October and December 1990. Drainage wells and public-supply wells were inventoried in a 14-square-mile area, and available data on land use and activities within each drainage well basin were tabulated. Three public-supply wells (tapping the Lower Floridan aquifer) and 38 drainage wells (open to the Upper Floridan aquifer) were located in 17 drainage basins within the study area. The primary sources of drainage-well inflow are lake overflow, street runoff, seepage from the surficial aquifer system, and process-wastewater disposal. Drainage-well inflow from a variety of ares, including resi- dential, commercial, undeveloped, paved, and industrial areas, are potential sources of con- taminants. The four general types of possible contaminants to drainage-well inflow are inorganic chemicals, organic compounds, turbidity, and microbiological contaminants. Potential contami- nant sources include plant nurseries, citrus groves, parking lots, plating companies, auto- motive repair shops, and most commonly, lake- overflow water. Drainage wells provide a pathway for contaminants to enter the Upper Floridan aquifer and there is a potential for contaminants to move downward from the Upper Floridan to the Lower Floridan aquifer.


    Energy Technology Data Exchange (ETDEWEB)

    J.B. Case


    The drainage of water from the emplacement drift is essential for the performance of the EBS. The unsaturated flow properties of the surrounding rock matrix and fractures determine how well the water will be naturally drained. To enhance natural drainage, it may be necessary to introduce engineered drainage features (e.g. drilled holes in the drifts), that will ensure communication of the flow into the fracture system. The purpose of the Water Drainage Model is to quantify and evaluate the capability of the drift to remove water naturally, using the selected conceptual repository design as a basis (CRWMS M&O, 1999d). The analysis will provide input to the Water Distribution and Removal Model of the EBS. The model is intended to be used to provide postclosure analysis of temperatures and drainage from the EBS. It has been determined that drainage from the EBS is a factor important to the postclosure safety case.

  14. total mercury concentration in common fish species of lake victoria ...

    African Journals Online (AJOL)

    Total mercury (THg) concentration was analysed in muscles of common fish species of Lake. Victoria in the eastern and southern parts of the lake using cold vapour Atomic Absorption. Spectrophotometric ... INTRODUCTION. The Lake Victoria ...

  15. Validation and inter-comparison of surface elevation changes derived from altimetry over the Jakobshavn Isbræ drainage basin, Greenland - Round Robin results from ESA's Ice_Sheets_CCI (United States)

    Fredenslund Levinsen, Joanna; Khvorostovsky, Kirill; Ticconi, Francesca


    Satellite observations have been used to monitor changes occurring on Earth's surface for more than a decade. The high temporal and spatial resolution of such measurements provides us with unique possibilities for monitoring the effects of the climate changes over glaciers and ice sheets. In order to ensure long-term climate records, ESA has launched the Climate Change Initiative (ESA CCI), which puts focus on 13 different Essential Climate Variables, one of them being Ice Sheets. In this program, four selected key parameters will be determined: Surface elevation changes (SEC), surface velocities, calving front locations, and grounding line locations. This work focuses on the first mentioned parameter, and the goal is to develop the best routine for estimating SEC on the Greenland Ice Sheet using radar altimeter data. In order to find the most optimal approach we have completed a Round Robin experiment in which researchers from various European and US institutions have provided SEC estimates derived from either ENVISAT or ICESat data, for the test area by Jakobshavn Isbræ drainage basin. This has allowed us to compare the results from radar vs. laser altimetry, cross-over vs. along-track analyses, and the use of time series vs. a direct estimation of SEC. The results were validated against airborne lidar data from NASA's IceBridge and ESA's CryoVex campaigns. It was found that both radar and laser altimetry resolve the surface elevation changes quite well, and that the erroneous results found mainly in the coastal region can be improved by combining the methods of repeat-tracks and cross-overs. The former has a higher spatial resolution however is limited by rarely overlapping ground tracks, and hence interpolation methods need to be introduced. Furthermore, errors are introduced particularly along the ice margin due to slope effects while, for both methods, penetration of the signal into the firn pack needs to be accounted for. Cross-overs have a lower spatial

  16. [Ascites drainage at home

    NARCIS (Netherlands)

    Lutjeboer, J.; Erkel, A.R. van; Hoeven, J.J.M. van der; Meer, R.W. van der


    Ascites can lead to many symptoms, and often occurs in patients with an end-stage malignancy such as ovarian, pancreatic, colonic, or gastric cancer. Intermittent ascites drainage is applied in these patients as a palliative measure. As frequent drainage is necessary, a subcutaneously tunnelled

  17. Seabed surveys of Victoria harbour, Mahe, Seychelles

    Digital Repository Service at National Institute of Oceanography (India)

    Hashimi, N.H.; Wagle, B.G.

    The seabed surveys in the Victoria Harbour, Mahe, Seychelles shows that the prominent feature is the navigational channel aligned in the northeast-southwest direction with a width varying from 300 to 450m. The depth in the channel ranges from 14...

  18. Geography and Geographical Education in Victoria (United States)

    Kriewaldt, Jeana


    Victoria has just emerged from 10 years where Geography has been one of three strands in the key learning area of Studies of Society and Environment (SOSE). The overarching framework emerged from an attempt to develop a national curriculum. Whilst the national curriculum was rejected by Australian state and territories who each hold legislative…

  19. D Digital Cadastre Journey in Victoria, Australia (United States)

    Shojaei, D.; Olfat, H.; Briffa, M.; Rajabifard, A.


    Land development processes today have an increasing demand to access three-dimensional (3D) spatial information. Complex land development may need to have a 3D model and require some functions which are only possible using 3D data. Accordingly, the Intergovernmental Committee on Surveying and Mapping (ICSM), as a national body in Australia provides leadership, coordination and standards for surveying, mapping and national datasets has developed the Cadastre 2034 strategy in 2014. This strategy has a vision to develop a cadastral system that enables people to readily and confidently identify the location and extent of all rights, restrictions and responsibilities related to land and real property. In 2014, the land authority in the state of Victoria, Australia, namely Land Use Victoria (LUV), has entered the challenging area of designing and implementing a 3D digital cadastre focused on providing more efficient and effective services to the land and property industry. LUV has been following the ICSM 2034 strategy which requires developing various policies, standards, infrastructures, and tools. Over the past three years, LUV has mainly focused on investigating the technical aspect of a 3D digital cadastre. This paper provides an overview of the 3D digital cadastre investigation progress in Victoria and discusses the challenges that the team faced during this journey. It also addresses the future path to develop an integrated 3D digital cadastre in Victoria.


    African Journals Online (AJOL)

    ABSTRACT. Seventeen species of parasites were recovered from 107 I Clarias gariepinus examined flom the. Mwanza Gulf of Lake Victoria. The parasite fauna comprised of four ectoparasites, a. Monogenea, Hirudinea, crustacean and a Digenea,' and fourteen endoparasites, five nematodes,. five trematodes and three ...

  1. Agricultural Drainage Well Intakes (United States)

    Iowa State University GIS Support and Research Facility — Locations of surface intakes for registered agriculture drainage wells according to the database maintained by IDALS. Surface intakes were located from their...

  2. Percutaneous Abscess Drainage (United States)

    ... and devices that monitor your heart beat and blood pressure. top of page How is the procedure performed? Image-guided, minimally invasive procedures such as percutaneous abscess drainage are most ...

  3. Surface Water & Surface Drainage (United States)

    Earth Data Analysis Center, University of New Mexico — This data set contains boundaries for all surface water and surface drainage for the state of New Mexico. It is in a vector digital data structure digitized from a...

  4. Mathematical Problems in Biology : Victoria Conference

    CERN Document Server


    A conference on "Some Mathematical Problems in Biology" was held at the University of Victoria, Victoria, B. C. , Canada, from May 7 - 10, 1973. The participants and invited speakers were mathematicians interested in problems of a biological nature, and scientists actively engaged in developing mathematical models in biological fields. One aim of the conference was to attempt to assess what the recent rapid growth of mathematical interaction with the biosciences has accomplished and may accomplish in the near future. The conference also aimed to expose the problems of communication bet~",een mathematicians and biological scientists, and in doing so to stimulate the interchange of ideas. It was recognised that the topic spans an enormous breadth, and little attempt was made to balance the very diverse areas. Widespread active interest was shown in the conference, and just over one hundred people registered. The varied departments and institutions across North America from which the participants came made it bo...

  5. Pancam Peek into 'Victoria Crater' (Stereo) (United States)


    [figure removed for brevity, see original site] Left-eye view of a stereo pair for PIA08776 [figure removed for brevity, see original site] Right-eye view of a stereo pair for PIA08776 A drive of about 60 meters (about 200 feet) on the 943rd Martian day, or sol, of Opportunity's exploration of Mars' Meridiani Planum region (Sept. 18, 2006) brought the NASA rover to within about 50 meters (about 160 feet) of the rim of 'Victoria Crater.' This crater has been the mission's long-term destination for the past 21 Earth months. Opportunity reached a location from which the cameras on top of the rover's mast could begin to see into the interior of Victoria. This stereo anaglyph was made from frames taken on sol 943 by the panoramic camera (Pancam) to offer a three-dimensional view when seen through red-blue glasses. It shows the upper portion of interior crater walls facing toward Opportunity from up to about 850 meters (half a mile) away. The amount of vertical relief visible at the top of the interior walls from this angle is about 15 meters (about 50 feet). The exposures were taken through a Pancam filter selecting wavelengths centered on 750 nanometers. Victoria Crater is about five times wider than 'Endurance Crater,' which Opportunity spent six months examining in 2004, and about 40 times wider than 'Eagle Crater,' where Opportunity first landed. The great lure of Victoria is the expectation that a thick stack of geological layers will be exposed in the crater walls, potentially several times the thickness that was previously studied at Endurance and therefore, potentially preserving several times the historical record.

  6. Implementation of the victoria bowel performance scale. (United States)

    Hawley, Philippa; Barwich, Doris; Kirk, Lisa


    There is a lack of evidence to guide constipation management in patients receiving palliative care. Data collection requires the systematic use of validated assessment tools. The objective of this study was to assess the usefulness of the Victoria Bowel Performance Scale (BPS) as an audit tool. Charts were reviewed before and after the implementation of a program to monitor constipation through repeated use of the Victoria Bowel Scale. The program was initiated at three oncology pain and symptom management clinics, four palliative care units, and four residential hospices. An additional "control" palliative care unit introduced new nursing assessment tools without the new scale. The Victoria BPS was recorded at 86% of 192 postimplementation outpatient clinic visits and was easy to use in this setting. Documentation of bowel performance at comparable visits improved from 44% to 66% (Passessment tool, uniquely incorporating the patient's usual bowel function. Modifications to the scale have been made to improve clarity and allow for the expected drop in bowel activity seen in end-of-life care. Considerable educational effort and appropriate organization of the charts are required for optimal implementation. The proportion of revised BPS scores ranging from -1 to +1 is proposed as an indicator of satisfactory bowel management for clinical, audit, and research purposes. Copyright © 2011 U.S. Cancer Pain Relief Committee. Published by Elsevier Inc. All rights reserved.

  7. The Impact of Drainage Reorganization on Cenozoic Topography (United States)

    Yanites, B. J.; Ehlers, T. A.


    Landscape evolution and the resulting sedimentary deposits are controlled by the development and organization of drainage basins. As a landscape evolves within a climatic and tectonic environment, drainage reorganization events can occur, where one river basin grows at the expense of another. The added discharge downstream of a river capture location will generate a transient topographic response. The records of these events are preserved the sedimentary record and modern topography. Drainage reorganization has been proposed to occur in a number of major drainage systems around the world including the Colorado, Rhine, Snake, Yellow, Yangtze, Indus, and Zambezi rivers as well as a number of smaller rivers. Yet little work has focused on quantifying the topographic and erosional consequence of such events. Here we propose a simple model that quantifies the impacts of drainage capture on the evolution of a drainage basin. The model is based on the inverse slope-contributing drainage area relationship observed in rivers throughout the world and describes the expected river elevation change as drainage area is added (and therefore slopes lowered) by a capture event. Furthermore, we develop a numerical model of drainage capture that quantifies the transience of erosion and sediment production based on a shear stress dependent fluvial incision and sediment transport model. Our focus here is on quantifying the impact of capture of the Rhine/Aare river system (~45,000 km2) during the late Pliocene/early Pleistocene. Our models suggest 500-800 m of river elevation change (lowering profiles) occurred over short time periods (less than a million years), contributing as much as 0.4 mm/yr of erosion to the Alpine foreland and Swiss Alps when averaged over the last few million years. The predicted incision magnitudes are consistent with incision measured from the elevation of Pliocene and early Pleistocene river gravels, suggesting that the majority of incision across northern

  8. Lake Victoria water resources management challenges and ...

    African Journals Online (AJOL)

    ... more sustainable and equitable framework governing management measures capable of meeting the needs of riparian states and ensuring sustainability within the basin is highlighted. Keywords: biodiversity loss; East Africa; eutrophication; heavy metal pollution; international treaties; Nile Basin; shared water resources

  9. Recent reduction in the water level of Lake Victoria has created more habitats for Anopheles funestus

    Directory of Open Access Journals (Sweden)

    Futami Kyoko


    Full Text Available Abstract Background The water level of Lake Victoria has fallen more than 1.5 m since 1998, revealing a narrow strip of land along the shore. This study determined whether the recent drop in the water level has created additional breeding grounds for malaria vectors. Methods The recent and past shorelines were estimated using landmarks and a satellite image. The locations of breeding habitats were recorded using a GPS unit during the high and low lake water periods. GIS was used to determine whether the breeding habitats were located on newly emerged land between the new and old shorelines. Results Over half of the breeding habitats existed on newly emerged land. Fewer habitats for the Anopheles gambiae complex were found during the low water level period compared to the high water period. However, more habitats for Anopheles funestus were found during the high water level period, and they were all located on the newly emerged land. Conclusion The recent reduction in water level of Lake Victoria has increased the amount of available habitat for A. funestus. The results suggest that the water drop has substantially affected the population of this malaria vector in the Lake Victoria basin, particularly because the lake has a long shoreline that may harbour many new breeding habitats.

  10. Urban eutrophication and its spurring conditions in the Murchison Bay of Lake Victoria. (United States)

    Kabenge, Martin; Wang, Hongtao; Li, Fengting


    The efficiency of Lake Victoria in providing its ecosystem services to riparian states, both immediate and along the Nile river basin, is strongly related to its water quality. Over the past few decades, eutrophication has increased in the lake arising from increased inflow of nutrients. This study was carried out in the Murchison Bay area of Lake Victoria with the aims of assessing the progress of eutrophication nutrient enrichment into the lake between 1990 and 2014. Using Landsat satellite floating algae index (FAI) products and data from laboratory analysis of water samples, the study revealed that floating algae reoccurred periodically with coverage varying between 1 and 18 km(2). The findings also indicated that the range of nitrate-nitrogen concentrations increased greatly with maximum concentrations recorded at 31.2 mg l(-1) in 2007 from 0.084 mg l(-1) in 1990. The soluble reactive phosphorus concentration range showed a maximum of 1.45 mg l(-1) in 2007 from 0.043 mg l(-1) in 1990. The chlorophyll levels increased from an average of 17 μg l(-1) in 1992 by threefold in 1996 but had however declined and halved in intensity by 2011. The eutrophication that has occurred in Lake Victoria over the past decades has been due to pollution from industrial, residential, and agricultural areas within the catchment.


    Directory of Open Access Journals (Sweden)

    Erick Ochieng OGELLO


    Full Text Available Lake Victoria is the largest among the African Great Lakes in East African region that are believed to have both dynamic and fragile aquatic ecosystems. Within two decades, the lake has experienced extensive resource exploitation leading to constrained productivity and drastic decline of native biodiversity. Intensive non-selective fishing, catchment vegetation degradation, industrial and agricultural pollution, the introduction of exotic species and uneven patchwork of governmental laws are some of the reasons for the current ecological woes facing Lake Victoria. This paper intends to stimulate recognition of Lake Victoria and its catchment as a lived Com­mons, to be shared, protected, managed and enjoyed by all who live around it. The paper compares the original biodiversity status of the lake with the current status and discusses the role of unlimited access as a function of the loss of the Lake’s biological wealth. The Lake’s water resource base, fishery, wetlands and other aquatic resources have been exhaustively discussed. In this review, we uphold the Hardin’s school of thought that freedom of the commoners causes resource overuse leading to poverty. Therefore, limiting freedom could be essential. However, there is need for provision of alternative means of survival since people with no choices would continue over-exploiting ecosystems even under limited access. The Lake Victoria basin commons should be protected by strict legal and clear political frame­work based on public trust doctrine, reinforced in law that the Lake is vital for the survival of people, plants and animals living on or near it and therefore must be protected for the common good. The political jurisdictions should consider governing the Lake basin as one integrated watershed. It is our fervent hope that bordering communities will secure grass root movements to protect and nurture Lake Victoria and its environs for the benefit of the present and future

  12. Freshwater Mussel Surveys Of The Pee Dee River Basin in South Carolina (United States)

    US Fish and Wildlife Service, Department of the Interior — The Pee Dee River Basin is a major drainage of the Atlantic slope in the southeastern United States. The 10,755 sq mile drainage area incorporates portions of...

  13. Ear drainage culture (United States)

    ... a lab and placed on a special dish (culture media). The lab team checks the dish every day ... Medical findings based on ear anatomy Ear drainage culture ... PR. The clinician and the microbiology laboratory. In: Bennett JE, Dolin R, Blaser MJ, ...

  14. Integrated urban drainage, status and perspectives

    DEFF Research Database (Denmark)

    Harremoës, Poul


    measures are local infiltration, source control, storage basins, local treatment and real time control. New paradigms have been introduced: risk of pollution due to system failure, technology for water reuse, sustainability, new architecture and greener up-stream solutions as opposed to down......This paper summarises the status of urban storm drainage as an integrated professional discipline, including the management-policy interface, by which the goals of society are implemented. The paper assesses the development of the discipline since the INTERURBA conference in 1992 and includes...

  15. Pitfalls in Cutaneous Melanoma Lymphatic Drainage. (United States)

    Voinea, Silviu; Sandru, Angela; Gherghe, Mirela


    Sentinel node (SN) biopsy has become standard in staging of cutaneous melanoma. As skin lymphatic drainage is complex, preoperative empirical assessment of SN localization is virtually impossible. Therefore in order to identify all regional lymphatic basins corresponding to a specific primary tumor is mandatory to carry out preoperative lymphoscintigraphy. In this paper we present a clinical case that highlights the importance of identifying, biopsy and histological analysis of all SN in order to achieve a correct staging of the patient, followed by appropriate treatment according to the real clinical stage of the disease. Celsius.

  16. Evaluation of Life Cycle Assessment (LCA) for Roadway Drainage Systems. (United States)

    Byrne, Diana M; Grabowski, Marta K; Benitez, Amy C B; Schmidt, Arthur R; Guest, Jeremy S


    Roadway drainage design has traditionally focused on cost-effectively managing water quantity; however, runoff carries pollutants, posing risks to the local environment and public health. Additionally, construction and maintenance incur costs and contribute to global environmental impacts. While life cycle assessment (LCA) can potentially capture local and global environmental impacts of roadway drainage and other stormwater systems, LCA methodology must be evaluated because stormwater systems differ from wastewater and drinking water systems to which LCA is more frequently applied. To this end, this research developed a comprehensive model linking roadway drainage design parameters to LCA and life cycle costing (LCC) under uncertainty. This framework was applied to 10 highway drainage projects to evaluate LCA methodological choices by characterizing environmental and economic impacts of drainage projects and individual components (basin, bioswale, culvert, grass swale, storm sewer, and pipe underdrain). The relative impacts of drainage components varied based on functional unit choice. LCA inventory cutoff criteria evaluation showed the potential for cost-based criteria, which performed better than mass-based criteria. Finally, the local aquatic benefits of grass swales and bioswales offset global environmental impacts for four impact categories, highlighting the need to explicitly consider local impacts (i.e., direct emissions) when evaluating drainage technologies.


    African Journals Online (AJOL)

    Victoria. Netherlands Journal of. Zoology 42'. 214 -232. Witte F, Goldschmidt PC and Wanink JH. 1995. Dynamics of the haplochromine cichlid fauna and other ecological changes in the. Mwanza gmlf of Lake Victoria. In: Pitcher TH and Hart PJB (eds):. Impact of species change in fiican lakes. Chapman & Hall, London, pp.

  18. Adaptive responses to environmental changes in Lake Victoria cichlids

    NARCIS (Netherlands)

    Rijssel, Jacobus Cornelis van (Jacco)


    Lake Victoria cichlids show the fastest vertebrate adaptive radiation known which is why they function as a model organism to study evolution. In the past 40 years, Lake Victoria experienced severe environmental changes including the boom of the introduced, predatory Nile perch and eutrophication.

  19. Gender Integration in the Management of the Lake Victoria Fisheries ...

    African Journals Online (AJOL)

    The riparian governments of Lake Victoria have adopted co-management approach in fisheries management. This paper discusses gender mainstreaming in fisheries management of Lake Victoria, user rights, successes and challenges of the process. This paper has used gender-disaggregated data from several studies ...

  20. Regional view of a Trans-African Drainage System

    Directory of Open Access Journals (Sweden)

    Mohamed Abdelkareem


    Full Text Available Despite the arid to hyperarid climate of the Great Sahara of North Africa, pluvial climates dominated the region. Radar data shed some light on the postulated Trans-African Drainage System and its relationship to active and inactive tributaries of the Nile basin. Interpretations of recent elevation data confirm a source of the river water from the Red Sea highlands did not connect the Atlantic Ocean across Tushka basin, highlands of Uwinate and Darfur, and Chad basin, but northward to the ancestral Nile Delta. Elements of topography and climate were considered. They show that the former segments of the Nile closely mirror present-day tributaries of the Nile basin in drainage geometry, landscape, and climate. A rainfall data interpolation scenario revealed that this basin received concurrent runoff from both flanks such as Gabgaba-Allaqi to the east and Tushka basin to the west, similar to present-day Sobat and White Nile tributaries, respectively. Overall the western tributaries such as those of Tushka basin and Howar lead to the Nile, which was (and still is the biggest river system in Africa.

  1. Dynamic reorganization of river basins. (United States)

    Willett, Sean D; McCoy, Scott W; Perron, J Taylor; Goren, Liran; Chen, Chia-Yu


    River networks evolve as migrating drainage divides reshape river basins and change network topology by capture of river channels. We demonstrate that a characteristic metric of river network geometry gauges the horizontal motion of drainage divides. Assessing this metric throughout a landscape maps the dynamic states of entire river networks, revealing diverse conditions: Drainage divides in the Loess Plateau of China appear stationary; the young topography of Taiwan has migrating divides driving adjustment of major basins; and rivers draining the ancient landscape of the southeastern United States are reorganizing in response to escarpment retreat and coastal advance. The ability to measure the dynamic reorganization of river basins presents opportunities to examine landscape-scale interactions among tectonics, erosion, and ecology.

  2. Degradation of Victoria Crater, Meridiani Planum, Mars (United States)

    Grant, J. A.; Wilson, S. A.; Cohen, B. A.; Golombek, M. P.; Geissler, P. E.; Sullivan, R. J.


    Victoria crater (2.05N, 354.51E) is ~750 m in diameter and the largest crater on Mars observed in situ. The Mars Exploration Rover Opportunity traversed NW to SE across a broad annulus dominated by dark sand that at least partially surrounds the crater before navigating the northern crater rim. Rover observations of the crater and ejecta deposits are complemented by images with 26-52 cm/pixel scales from the High Resolution Imaging Science Experiment (HiRISE) on Mars Reconnaissance Orbiter and enable assessment of degradation state. The present depth/diameter ratio for Victoria is 0.1, less than the 0.2 expected for a pristine primary impact structure. Together with the eroded, serrated rim, this implies an originally smaller crater diameter and/or considerable infilling consistent with occurrence of a large dune field and few exposed rocks on the crater floor. The height and width of the raised rim is generally 4-5 m and 150-225 m, respectively, less than the 30 m and 500-600 m, respectively, expected for a pristine 750 m diameter crater. Ejecta thicknesses around the rim were derived using rover-based and HiRISE images and yield consistent estimates averaging ~3 m. The serrated rim plan creates a series of promontories extending up to 50 m into the crater and generally fronted by 30-60 degree slopes that are locally vertical and are separated by bays whose floors typically slope 15-25 degrees. A crater originally on order of 600-650 m in diameter and subsequently enlarged by mass wasting and aeolian erosion may yield a structure resembling Victoria today. The steep expression of the promontories and local outcroppings of rocks in the ejecta blanket points to some ongoing mass wasting, but the relative paucity of associated flanking talus indicates derived blocks of sulfate sandstone are not resistant to saltating sand and are rapidly broken down by the wind or are completely covered/filled in by aeolian drift. At Cape St. Vincent, the promontory appears undercut

  3. Wound Drainage Culture (For Parents) (United States)

    ... a Voice in Health Care Decisions Wound Drainage Culture KidsHealth > For Parents > Wound Drainage Culture Print A A A What's in this article? ... Have Questions What It Is A wound drainage culture is a test to detect germs such as ...

  4. Acid mine drainage (United States)

    Bigham, Jerry M.; Cravotta, Charles A.


    Acid mine drainage (AMD) consists of metal-laden solutions produced by the oxidative dissolution of iron sulfide minerals exposed to air, moisture, and acidophilic microbes during the mining of coal and metal deposits. The pH of AMD is usually in the range of 2–6, but mine-impacted waters at circumneutral pH (5–8) are also common. Mine drainage usually contains elevated concentrations of sulfate, iron, aluminum, and other potentially toxic metals leached from rock that hydrolyze and coprecipitate to form rust-colored encrustations or sediments. When AMD is discharged into surface waters or groundwaters, degradation of water quality, injury to aquatic life, and corrosion or encrustation of engineered structures can occur for substantial distances. Prevention and remediation strategies should consider the biogeochemical complexity of the system, the longevity of AMD pollution, the predictive power of geochemical modeling, and the full range of available field technologies for problem mitigation.

  5. Sustainable Drainage Systems


    Miklas Scholz


    Urban water management has somewhat changed since the publication of The Sustainable Drainage System (SuDS) Manual in 2007 [1], transforming from building traditional sewers to implementing SuDS, which are part of the best management practice techniques used in the USA and seen as contributing to water-sensitive urban design in Australia. Most SuDS, such as infiltration trenches, swales, green roofs, ponds, and wetlands, address water quality and quantity challenges, and enhance the local bio...

  6. The Bands Culture in Victoria, Australia: Live Music Benefits Career Paths, Employment and Community (United States)

    Watson, Amanda; Forrest, David


    This study explores the career paths, employment, business opportunities and community contributions made available through the provision and development of the contemporary performance bands' culture in the State of Victoria. It is framed with the support given to live music performers by Arts Victoria, Small Business Victoria and Music Victoria.…

  7. Drainage of curd


    Akkerman, J. C.


    Cheese making starts with transformation of the liquid milk into a gel by proteolytic enzymes and/or acid producing bacteria. The gel is cut into pieces. The protein matrix contracts, by which whey is expelled from the pieces, this process is called syneresis. The process of whey expulsion is enhanced by stirring and usually heating. Finally fairly rigid curd grains and a large amount of whey are obtained. The subsequent separation of whey and curd grains is called drainage of curd. ...

  8. Accounting for Violence at the Victoria Industrial School

    National Research Council Canada - National Science Library

    Bryan Hogeveen


    Boys who were inmates at the Victoria Industrial School (VIS) from its opening in 1887 to its closure in 1934 often suffered extreme, violent, and capricious penalties and encountered calculated psychological manipulation...

  9. Ecological Biogeography of the Terrestrial Nematodes of Victoria Land, Antarctica (United States)

    Adams, Byron J.; Wall, Diana H.; Virginia, Ross A.; Broos, Emma; Knox, Matthew A.


    Abstract The terrestrial ecosystems of Victoria Land, Antarctica are characteristically simple in terms of biological diversity and ecological functioning. Nematodes are the most commonly encountered and abundant metazoans of Victoria Land soils, yet little is known of their diversity and distribution. Herein we present a summary of the geographic distribution, habitats and ecology of the terrestrial nematodes of Victoria Land from published and unpublished sources. All Victoria Land nematodes are endemic to Antarctica, and many are common and widely distributed at landscape scales. However, at smaller spatial scales, populations can have patchy distributions, with the presence or absence of each species strongly influenced by specific habitat requirements. As the frequency of nematode introductions to Antarctica increases, and soil habitats are altered in response to climate change, our current understanding of the environmental parameters associated with the biogeography of Antarctic nematofauna will be crucial to monitoring and possibly mitigating changes to these unique soil ecosystems. PMID:25061360

  10. Victoria Land, Ross Sea, and Ross Ice Shelf, Antarctica (United States)


    On December 19, 2001, MODIS acquired data that produced this image of Antarctica's Victoria Land, Ross Ice Shelf, and the Ross Sea. The coastline that runs up and down along the left side of the image denotes where Victoria Land (left) meets the Ross Ice Shelf (right). The Ross Ice Shelf is the world's largest floating body of ice, approximately the same size as France. Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

  11. A suspended sediment yield predictive equation for river basins in ...

    African Journals Online (AJOL)

    An empirical equation that can be used for estimating the suspended sediment yields of river drainage basins without sediment data has been established for basins in the sub-tropical forest Southwestern river basin system of Ghana. The power law equation relates mean annual specific suspended sediment yield (t km-2 ...

  12. Estimating stream discharge of Aboine River Basin of Southeast ...

    African Journals Online (AJOL)

    Results of bifurcation ratio, compactness coefficient, stream length and modeling of inter-basin parameters showed that the Aboine drainage basin is basically a flat surface. This will affect both the amount of water available from the basin for any water resources projects. Such information also provides the basis for ...

  13. Drainage capture and discharge variations driven by glaciation in the Southern Alps, New Zealand

    Energy Technology Data Exchange (ETDEWEB)

    Ann V. Rowan; Mitchell A. Plummer; Simon H. Brocklehurst; Merren A. Jones; David M. Schultz


    Sediment flux in proglacial fluvial settings is primarily controlled by discharge, which usually varies predictably over a glacial–interglacial cycle. However, glaciers can flow against the topographic gradient to cross drainage divides, reshaping fluvial drainage networks and dramatically altering discharge. In turn, these variations in discharge will be recorded by proglacial stratigraphy. Glacial-drainage capture often occurs in alpine environments where ice caps straddle range divides, and more subtly where shallow drainage divides cross valley floors. We investigate discharge variations resulting from glacial-drainage capture over the past 40 k.y. for the adjacent Ashburton, Rangitata, and Rakaia basins in the Southern Alps, New Zealand. Although glacial-drainage capture has previously been inferred in the range, our numerical glacier model provides the first quantitative demonstration that this process drives larger variations in discharge for a longer duration than those that occur due to climate change alone. During the Last Glacial Maximum, the effective drainage area of the Ashburton catchment increased to 160% of the interglacial value with drainage capture, driving an increase in discharge exceeding that resulting from glacier recession. Glacial-drainage capture is distinct from traditional (base level–driven) drainage capture and is often unrecognized in proglacial deposits, complicating interpretation of the sedimentary record of climate change.

  14. Impact of acid mine drainage from mining exploitations on the Margajita River basin and the Hatillo reservoir (Dominican Republic); Impacto del drenaje acido de explotaciones mineras en la cuenca del Rio Margajita y Embalse de Hatillo (Republica Dominicana)

    Energy Technology Data Exchange (ETDEWEB)

    Grandia, F.; Salas, J.; Arcos, D.; Archambault, A.; Cottard, F.


    Mining of the Pueblo Viejo high-sulphidation epithermal deposit (Dominican Republic) leads to environmental impact due to the formation of acid mine drainage associated with the oxidative dissolution of sulphides and sulpho salts. In addition to the very low pH, the acid waters are capable of transporting away from the mining areas high concentrations of metals and metalloids in solution. In the present work, a geochemical study of sediments deposited in the Hatillo reservoir is carried out. This reservoir is fed by the Margajita and Yuna streams which transport leachates from the Pueblo Viejo and Falcondo-Bonao (Cr-Ni) mining areas, respectively. The results show that these sediments have very high concentrations of Fe, Al and sulphate, along with significant amounts of As, Zn and Te, which are of especial environmental concern. The main contributor to this metal discharge into the reservoir is the Margajita stream, whereas the Yuna stream does not transport significant amounts of metals in solution due to its neutral pH, although it is likely that metals such as Mn, Cr, Ni and Co can be mobilised as a particulate. (Author) 5 refs.

  15. Geothermal investigations in Idaho. Part 12. Stable isotopic evaluation of thermal water occurrences in the Weiser and Little Salmon River drainage basins and adjacent areas, west-central Idaho with attendant gravity and magnetic data on the Weiser area

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, J.C.; Bideganeta, K.; Palmer, M.A.


    Fifteen thermal springs, two thermal wells, and eight cold springs in the Weiser and Little Salmon river drainages were sampled for deuterium and oxygen-18 analysis during the fall of 1981. The straight-line fit of delta D and delta /sup 18/O versus latitude and longitude observed in the data is what would be expected if the recharge areas for the thermal and non-thermal waters were in close proximity to their respective discharge points. The discrete values of delta D and delta /sup 18/O for each thermal discharge suggest that none of the sampled thermal systems have common sources. The depleted deuterium and oxygen-18 contents of most thermal relative to non-thermal waters sampled suggests that the thermal waters might be Pleistocene age precipitation. The isotopic data suggest little or no evidence for mixing of thermal and non-thermal water for the sampled discharges. Thermal waters from Weiser, Crane Creek, Cove Creek, and White Licks hot springs show enrichment in oxygen-18 suggesting that these waters have been at elevated temperatures relative to other sampled thermal discharges in the area. Gravity and magnetic data gathered by the Idaho State University Geology Department in the Weiser Hot Springs area suggest that southeastward plunging synclinal-anticlinal couples, which underlie the hot springs, are cut south of the springs by a northeast trending boundary fault.

  16. adequacy of drainage channels f drainage channels in a small

    African Journals Online (AJOL)


    analysis, construction and maintenance of drainage c. Keywords: Keywords: Time of concentration, ... nwamba of Civil Engineering Department, University of Nigeria Nsuk. F DRAINAGE CHANNELS IN A SMALL URBAN .... The assessment of extreme precipitation is an important problem in hydrologic risk analysis and.

  17. Nocturnal drainage wind characteristics in two converging air sheds

    Energy Technology Data Exchange (ETDEWEB)

    Gedayloo, T.; Clements, W.E.; Barr, S.; Archuleta, J.A.


    During the short experimental period in the Grants Basin of Northeastern New Mexico a survey was conducted on the complex meteorology of this area. Emphasis was placed on the nocturnal drainage flow because of the potential hazards to the populated areas of Milan and Grants from the effluents of the uranium mining and milling operation in this area. This investigation has shown that the nocturnal drainage flow patterns agree with the winds predicted on the basis of the complex terrain of the area. Because of the surface cooling at night (over 25/sup 0/C during summer and about 20/sup 0/C during winter), air from elevated surrounding areas flows to the low lying regions consequently setting up a nocturnal drainage flow. This regime exists over 60% of the time during summer months and over 65% of the time during winter months with a depth generally less than 200 m. In the San Mateo air shed the drainage flow is east northeast, and in the Ambrosia Lake air shed it is from northwest. The confluence of these two air flows contributes mainly to the drainage flow through the channel formed by La Ja Mesa and Mesa Montanosa. The analysis of data collected by the recording Flats Station confirms the prediction that although the area south of the channel region broadens considerably causing a reduction in flow speed, contributions from the southside of La Jara Mesa and Mesa Montanosa partly compensate for this reduction. The position of this recording station is 15 to 20 km from the populated towns of Milan and Grants. A drainage flow speed of approximately 2.2 m s/sup -1/ and the duration of over 11 hours as recorded by this station indicates that air from the San Mateo and Ambrosia Lake regions may be transported southwards to these population centers during a nocturnal period. In order to test this prediction, a series of multi-atmospheric tracer experiments were conducted in the Grants Basin.

  18. The Early (Feminist Essays of Victoria Ocampo

    Directory of Open Access Journals (Sweden)

    Doris Meyer


    Full Text Available This study examines the essays written by Ocampo between 1920 and 1934, prior to the time when she publicly voiced her adhesion to feminism and the rights of women in Argentine society. In these works from her Testimonios in which Ocampo struggles to find her voice as a female writer, the maleable essay serves her need to engage in discursive dialogues from the margins of the literary culture of her time. Both as a woman and a member of the oligarchy, she questions cultural assumptions and gender-based binary structures common among the male writers of her time, many of whom she knew personally. Using rhetorical strategies that show the self-reflexive and subversive nature of her writing, Ocampo reads and reinterprets these works from a parenthetical feminist perspective, contesting their intellectual and aesthetic biases. The active agency of the reader as writer in these early essays shows Ocampo's awareness of her own unorthodox subject position—alienated from the conventions of her class, her gender, her national culture and language. Her autobiographical musings and her engagement with literary modernity in the 1920s and 1930s reveal a woman who accepted the liabilities of articulating an autonomous self, both in a European and a Latin American context. The influence of family bonds and patriarchal morality decisively shaped, but did not ultimately control, the way Victoria Ocampo eventually defined herself as a feminist author.

  19. Sustainable Drainage Systems

    Directory of Open Access Journals (Sweden)

    Miklas Scholz


    Full Text Available Urban water management has somewhat changed since the publication of The Sustainable Drainage System (SuDS Manual in 2007 [1], transforming from building traditional sewers to implementing SuDS, which are part of the best management practice techniques used in the USA and seen as contributing to water-sensitive urban design in Australia. Most SuDS, such as infiltration trenches, swales, green roofs, ponds, and wetlands, address water quality and quantity challenges, and enhance the local biodiversity while also being acceptable aesthetically to the public. Barriers to the implementation of SuDS include adoption problems, flood and diffuse pollution control challenges, negative public perception, and a lack of decision support tools addressing, particularly, the retrofitting of these systems while enhancing ecosystem services. [...


    Directory of Open Access Journals (Sweden)

    Innocent A. Ugbong


    Full Text Available In order to achieve the task of formulating an optimal drainage model for the Calabar area, the Calabar drainage system was studied using some cartographic techniques to analyze its surface run-off and channel characteristics so as to determine how floods are generated. A morphological analysis was done, using detailed contour maps prepared for the study area. The “Blue line” and “contour crenulations” methods were used to recreate the expected run-off channels or drainage networks under natural non-urbanized conditions. A drainage structure with 6 major basins and 73 sub-basins was discovered. Existing storm drains were constructed without regards to this natural structure and so floods were generated.

  1. Rainfall, Discharge, and Water-Quality Data During Stormwater Monitoring, July 1, 2007, to June 30, 2008; Halawa Stream Drainage Basin and the H-1 Storm Drain, Oahu, Hawaii (United States)

    Presley, Todd K.; Jamison, Marcael T.J.; Young, Stacie T.M.


    Storm runoff water-quality samples were collected as part of the State of Hawaii Department of Transportation Stormwater Monitoring Program. The program is designed to assess the effects of highway runoff and urban runoff on Halawa Stream and to assess the effects from the H-1 storm drain on Manoa Stream. For this program, rainfall data were collected at three stations, continuous discharge data at four stations, and water-quality data at six stations, which include the four continuous discharge stations. This report summarizes rainfall, discharge, and water-quality data collected between July 1, 2007, and June 30, 2008. A total of 16 environmental samples were collected over two storms during July 1, 2007, to June 30, 2008, within the Halawa Stream drainage area. Samples were analyzed for total suspended solids, total dissolved solids, nutrients, chemical oxygen demand, and selected trace metals (cadmium, chromium, copper, lead, and zinc). Additionally, grab samples were analyzed for oil and grease, total petroleum hydrocarbons, fecal coliform, and biological oxygen demand. Some samples were analyzed for only a partial list of these analytes because an insufficient volume of sample was collected by the automatic samplers. Three additional quality-assurance/quality-control samples were collected concurrently with the storm samples. A total of 16 environmental samples were collected over four storms during July 1, 2007, to June 30, 2008 at the H-1 Storm Drain. All samples at this site were collected using an automatic sampler. Samples generally were analyzed for total suspended solids, nutrients, chemical oxygen demand, oil and grease, total petroleum hydrocarbons, and selected trace metals (cadmium, chromium, copper, lead, nickel, and zinc), although some samples were analyzed for only a partial list of these analytes. During the storm of January 29, 2008, 10 discrete samples were collected. Varying constituent concentrations were detected for the samples collected

  2. Multi-tree Coding Method (MCM) for drainage networks supporting high-efficient search (United States)

    Wang, Hao; Fu, Xudong; Wang, Guangqian


    River coding method for drainage networks plays an very important role in the physical simulation of river basins. In this study we developed a new river coding method named Multi-tree Coding Method (MCM), which has the following features: (1) it is established on a topological pattern reflecting the dendriform structure of drainage networks; (2) the multi-tree code can be effectively managed by the database to perform convenient topological search toward drainage networks using Structured Query Language (SQL); (3) the multi-tree code does not exhibit digital overflow problems in the computer, thus any resolution and scale drainage networks can easily be coded; and (4) it supports high-efficient search process. A river reach can be directly positioned in a drainage network under MCM, without the complex search process from all river reaches. This feature has great potential to improve the computational performance of basin models. We demonstrate here the efficiency and practicality of MCM by testing it in the Yalu Tsangpo river basin, Tibet. A drainage network with 140,745 digital reaches was extracted from the digital elevation model (DEM), and the multi-tree codes of all river reaches were obtained.

  3. Solid Waste in Drainage Network of Rio do Meio Watershed, Florianópolis/SC

    Directory of Open Access Journals (Sweden)

    Taiana Gava


    Full Text Available The urban drainage network is among the main pollution transport load factors. Researches on the identification of solid waste transported in the drainage network have been considered the allow evaluation of its impact. In this paper we analyze the main characteristics that influences the presence of solid wastes in the drainage network of the Rio do Meio basin, Florianópolis/SC. A metal net was installed in selected river section and monitored after each rain event. The results showed about 0.27 kg/ha.year of waste are carried in the drainage network. The majority being composed of plastics and building materials. Through the analysis of the data, it was possible to verify the presence of waste in the drainage network is due to poor packaging and to the lack of sweeping in some parts of the basin. It was also found that the total precipitation is directly proportional to the appearance of solid waste. It was concluded that the lack of an integrated management between the components of sanitary system leave unnoticed simple structural measures that ultimately decrease the amount of solid waste in the drainage basin, and that could eliminate this source of pollution.

  4. Qualitative and quantitative study on drainage networks at laboratory scale (United States)

    Oliveto, G.; Palma, D.; di Domenico, A.


    Although simulated drainage networks at the laboratory scale would represent highly-simplified models of natural drainages, they would provide a significant contribute to the comprehension of the complex dynamics governing the fluvial systems. Laboratory experiments also give the advantage to detect transient growth phases shedding some light on the knowledge of temporal and spatial landform evolution. Perhaps, pioneering laboratory experiments on drainage network evolution were carried out in 1977 at REF (Rainfall Erosion Facility) of Colorado State University by Schumm and co-workers. This study deals with an analysis of physical experiments simulating the evolution and the development of drainage networks. To this purpose, some experiments were carried out at University of Basilicata by using a 1.5 m by 1.5 m box-basin-simulator with an outlet incised in the middle of the downslope-end side. The experimental landscape was made of a weakly cohesive soil mainly constituted by clay and silt. A system of microsprinklers generated an almost uniform artificial precipitation. Simulations were performed at a constant rainfall rate with intensity of 100 mm/h. In total four experiments were carried out. Three of those were conducted by ensuring consistent initial conditions except for the initial landscape planar slope of 9%, 5%, and 0.6%, respectively. The remaining experiment was performed with a landscape slope of 9% again, but with the (surface) base-level coinciding with the base of the outlet (i.e. streams could not erode below the base-level). Despite the central outlet constraint, the generated stream system for the 9% plane exhibited trellis-like drainage patterns with many short tributaries joining the main stream at nearly right angles. For the 5% experiment still sub-parallel drainage patterns were formed but mainly in the centre of the watershed. Channels were clearly shallower than those of the 9% experiment. For the gentler slope of 0.6% dendritic drainage

  5. Rainfall, Discharge, and Water-Quality Data During Stormwater Monitoring, July 1, 2008, to June 30, 2009 - Halawa Stream Drainage Basin and the H-1 Storm Drain, Oahu, Hawaii (United States)

    Presley, Todd K.; Jamison, Marcael T.J.


    Storm runoff water-quality samples were collected as part of the State of Hawaii Department of Transportation Stormwater Monitoring Program. The program is designed to assess the effects of highway runoff and urban runoff on Halawa Stream, and to assess the effects from the H-1 storm drain on Manoa Stream. For this program, rainfall data were collected at three stations, continuous discharge data at five stations, and water-quality data at six stations, which include the five continuous discharge stations. This report summarizes rainfall, discharge, and water-quality data collected between July 1, 2008, and June 30, 2009. Within the Halawa Stream drainage area, three storms (October 25 and December 11, 2008, and February 3, 2009) were sampled during July 1, 2008, to June 30, 2009. A total of 43 environmental samples were collected during these three storms. During the storm of October 25, 2009, 31 samples were collected and analyzed individually for metals only. The other 12 samples from the other two storms were analyzed for some or all of the following analytes: total suspended solids, total dissolved solids, nutrients, chemical oxygen demand, and selected trace metals (cadmium, chromium, copper, lead, and zinc). Additionally, grab samples were analyzed for some or all of the following analytes: oil and grease, total petroleum hydrocarbons, fecal coliform, and biological oxygen demand. Some grab and composite samples were analyzed for only a partial list of these analytes, either because samples could not be delivered to the laboratory in a timely manner, or an insufficient volume of sample was collected by the automatic samplers. Two quality-assurance/quality-control samples were collected after cleaning automatic sampler lines to verify that the sampling lines were not contaminated. Four environmental samples were collected at the H-1 Storm Drain during July 1, 2008, to June 30, 2009. An oil and grease sample and a composite sample were collected during the

  6. A Novel Mediastinal Drainage Tube for Mediastinitis

    Directory of Open Access Journals (Sweden)

    Jun Ho Yhang


    Full Text Available Mediastinitis is a life-threatening disease, and effective drainage is needed to treat mediastinitis with abscess formation. We recommend an alternative drainage method using chest tube binding with a Silastic Penrose drainage tube. The use of a Silastic Penrose drainage tube may help to manage mediastinitis with abscess formation. This method facilitates effective draining and prevents tissue adhesion.

  7. An assessement of the ecosystem health of Lake Victoria (East Africa)

    African Journals Online (AJOL)

    An assessement of the ecosystem health of Lake Victoria (East Africa): Current status, trends and impacts to fishery. ... complicated the ecosystem dynamics of Lake Victoria and pose serious uncertainties about its future stability and sustainability of the fisheries resources. Lake Victoria's future sustainability requires ...

  8. Spatiotemporal Evaluation of Nocturnal Cold Air Drainage Over a Simple Slope Using Thermal Infrared Imagery (United States)

    Ikani, V.; Chokmani, K.; Fathollahi, L.; Granberg, H.; Fournier, R.


    Measurements of climatic processes such as cold air drainage flows are problematic over mountainous areas. Observation of cold air drainage is not available in the existing observation network and it requires a special methodology. The main objective of this study was to characterize the cold air drainage over regions with a slope. A high resolution infrared camera, a meteorological station and Digital Elevation Model (DEM) were used. The specific objective was to derive nocturnal cold air drainage velocity over the slope. To address these objectives, a number of infrared measurement campaigns were conducted during calm and clear sky conditions over an agricultural zone (blackcurrant farm) in Canada. Using thermal infrared images, the nocturnal surface temperature gradient were computed in hourly basis. The largest gradient magnitudes were found between 17h -20h. The cooling rates at basin area were two times higher in comparison to the magnitudes observed within slope area. The image analysis illustrated this considerable temperature gradient of the basin may be partly due to transport of cold air drainage into the basin from the slope. The results show that thermal imagery can be used to characterize and understand the microclimate related to the occurrence of radiation frost in the agricultural field. This study provided the opportunity to track the cold air drainage flow and pooling of cold air in low lying areas. The infrared analysis demonstrated that nocturnal drainage flow displayed continuous variation in terms of space and time in response to microscale slope heterogeneities. In addition, the analysis highlighted the periodic aspect for cold air drainage flow.

  9. Contravention of town planning regulations in Ikoyi and Victoria ...

    African Journals Online (AJOL)

    The study investigated possible relationships between educational attainment, awareness of town planning regulations and contravening these regulations in Ikoyi and Victoria Island, Lagos. Both primary and secondary data were used for the study. Secondary data were obtained from both published and unpublished ...


    Directory of Open Access Journals (Sweden)

    D. Shojaei


    Full Text Available Land development processes today have an increasing demand to access three-dimensional (3D spatial information. Complex land development may need to have a 3D model and require some functions which are only possible using 3D data. Accordingly, the Intergovernmental Committee on Surveying and Mapping (ICSM, as a national body in Australia provides leadership, coordination and standards for surveying, mapping and national datasets has developed the Cadastre 2034 strategy in 2014. This strategy has a vision to develop a cadastral system that enables people to readily and confidently identify the location and extent of all rights, restrictions and responsibilities related to land and real property. In 2014, the land authority in the state of Victoria, Australia, namely Land Use Victoria (LUV, has entered the challenging area of designing and implementing a 3D digital cadastre focused on providing more efficient and effective services to the land and property industry. LUV has been following the ICSM 2034 strategy which requires developing various policies, standards, infrastructures, and tools. Over the past three years, LUV has mainly focused on investigating the technical aspect of a 3D digital cadastre. This paper provides an overview of the 3D digital cadastre investigation progress in Victoria and discusses the challenges that the team faced during this journey. It also addresses the future path to develop an integrated 3D digital cadastre in Victoria.

  11. Research on School-Based Management in Victoria. (United States)

    Gamage, David T.; And Others


    Describes a 1992-93 research project involving 66 state schools that attempted to ascertain the overall effectiveness of school-based management in Victoria, Australia. Findings of the Likert-style survey revealed substantial participant satisfaction with school councils' current composition, information provision, and overall functioning. (20…

  12. Fishing Business Arrangements and Sustainability in Lake Victoria ...

    African Journals Online (AJOL)

    In this article an attempt is made to analyse the existing production relations between the owners of the vessels and the crewmembers and the concern for sustainability. Our results found that the existing sharing system in Lake Victoria poses a big challenge in as far as sustainability is concerned. Some of the system such ...

  13. Implementing Co-management of Lake Victoria's Fisheries ...

    African Journals Online (AJOL)

    There are still many challenges facing the sustainable management of Lake Victoria fisheries, including; lack of compliance with regulations and rapid increase in fishing effort, environmental degradation, inadequate service provision and the high prevalence of HIV/AIDS amongst the fishing communities. Key words: Lake ...

  14. The Lake Victoria Intense Storm Early Warning System (VIEWS) (United States)

    Thiery, Wim; Gudmundsson, Lukas; Bedka, Kristopher; Semazzi, Fredrick; Lhermitte, Stef; Willems, Patrick; van Lipzig, Nicole; Seneviratne, Sonia I.


    Weather extremes have harmful impacts on communities around Lake Victoria in East Africa. Every year, intense nighttime thunderstorms cause numerous boating accidents on the lake, resulting in thousands of deaths among fishermen. Operational storm warning systems are therefore crucial. Here we complement ongoing early warning efforts based on NWP, by presenting a new satellite data-driven storm prediction system, the prototype Lake Victoria Intense storm Early Warning System (VIEWS). VIEWS derives predictability from the correlation between afternoon land storm activity and nighttime storm intensity on Lake Victoria, and relies on logistic regression techniques to forecast extreme thunderstorms from satellite observations. Evaluation of the statistical model reveals that predictive power is high and independent of the input dataset. We then optimise the configuration and show that also false alarms contain valuable information. Our results suggest that regression-based models that are motivated through process understanding have the potential to reduce the vulnerability of local fishing communities around Lake Victoria. The experimental prediction system is publicly available under the MIT licence at

  15. Study of genetic variation in population of Bipolaris victoriae , the ...

    African Journals Online (AJOL)

    Isolates of Bipolaris victoriae were analysed by random amplified polymorphic DNA (RAPD) techniques to determine the amount of intraspecific genetic variability. Seven primers were applied and DNA bands of 200-5000 bp were produced. Cluster analysis using UPGMA method gave five groups. Levels of polymorphism ...

  16. Governance and Welfare of Fishing Communities of Lake Victoria ...

    African Journals Online (AJOL)

    ... have potable water or electricity. Educational standards remain low and many communities lack proper sanitation, and are therefore at risk of disease, while most basic facilities such as hospitals, schools and clinics are not within their reach. Key Words; Co-management, Beach Management Units, Lake Victoria, Health, ...

  17. Total mercury concentration in common fish species of Lake Victoria ...

    African Journals Online (AJOL)

    Total mercury (THg) concentration was analysed in muscles of common fish species of Lake Victoria in the eastern and southern parts of the lake using cold vapour Atomic Absorption Spectrophotometric technique. Mercury concentration in all fish species was generally lower than the WHO maximum allowable ...

  18. Transactional sex in the fishing communities along Lake Victoria ...

    African Journals Online (AJOL)

    The study describes the nature, context and implications of a unique form of transactional sexual relationships in the fishing communities along Lake Victoria in Kisumu County, Kenya. We conducted 12 focus group discussions and 17 key informant interviews among fishermen, fishmongers and fish transporters in Kisumu.

  19. Domestication of medicinal tree species in the Victoria lakeshore ...

    African Journals Online (AJOL)


    Therefore, there is high potential of marketing forest products by the subsistence farmers. Growing medicinal plants is one great opportunity for raising household incomes in this area. A survey was conducted among herbalists living around the Victoria lakeshore region. Questionnaires were administered through formal ...

  20. Catalogue Use at the State Library of Victoria (United States)

    Hider, Philip


    A questionnaire survey conducted at the State Library of Victoria indicates that users in general, and not just scholars, value the standard elements of bibliographic data found in the Library's catalogues, and consider all these elements useful for finding, identifying and selecting items. Rather than making do with less, users wanted more…

  1. Vocabulary Size Research at Victoria University of Wellington, New Zealand (United States)

    Nation, Paul; Coxhead, Averil


    The English Language Institute (now the School of Linguistics and Applied Language Studies) at Victoria University of Wellington has a long history of corpus-based vocabulary research, especially after the arrival of the second director of the institute, H. V. George, and the appointment of Helen Barnard, whom George knew in India. George's…

  2. Early warnings of hazardous thunderstorms over Lake Victoria

    NARCIS (Netherlands)

    Thiery, Wim; Gudmundsson, Lukas; Bedka, Kristopher; Semazzi, Fredrick H.M.; Lhermitte, S.L.M.; Willems, Patrick; van Lipzig, Nicole P. M.; Seneviratne, Sonia I.


    Weather extremes have harmful impacts on communities around Lake Victoria in East Africa. Every year, intense nighttime thunderstorms cause numerous boating accidents on the lake, resulting in thousands of deaths among fishermen. Operational storm warning systems are therefore crucial. Here we

  3. Lake Victoria's Water Budget and the Potential Effects of Climate ...

    African Journals Online (AJOL)

    This paper presents the Lake Victoria water budget for the period 1950-2004 and findings of a study on potential climate change impact on the lake's Hydrology through the 21st Century. The mass balance components are computed from measured and simulated data. A2 and B2 emission scenarios of the Special Report ...

  4. Early warnings of hazardous thunderstorms over Lake Victoria (United States)

    Thiery, Wim; Gudmundsson, Lukas; Bedka, Kristopher; Semazzi, Fredrick H. M.; Lhermitte, Stef; Willems, Patrick; van Lipzig, Nicole P. M.; Seneviratne, Sonia I.


    Weather extremes have harmful impacts on communities around Lake Victoria in East Africa. Every year, intense nighttime thunderstorms cause numerous boating accidents on the lake, resulting in thousands of deaths among fishermen. Operational storm warning systems are therefore crucial. Here we complement ongoing early warning efforts based on numerical weather prediction, by presenting a new satellite data-driven storm prediction system, the prototype Lake Victoria Intense storm Early Warning System (VIEWS). VIEWS derives predictability from the correlation between afternoon land storm activity and nighttime storm intensity on Lake Victoria, and relies on logistic regression techniques to forecast extreme thunderstorms from satellite observations. Evaluation of the statistical model reveals that predictive power is high and independent of the type of input dataset. We then optimise the configuration and show that false alarms also contain valuable information. Our results suggest that regression-based models that are motivated through process understanding have the potential to reduce the vulnerability of local fishing communities around Lake Victoria. The experimental prediction system is publicly available under the MIT licence at

  5. Climate Change and Fishery Sustainability in Lake Victoria ...

    African Journals Online (AJOL)

    The fisheries of Lake Victoria have recently undergone rapid ecological and social change. Loss of diversity in terms of species richness and economic opportunity has increased the system's vulnerability to additional economic, ecological, and social stressors predicted with future climate change. This paper discusses the ...

  6. Upper Paleozoic glacigenic deposits of Gondwana: Stratigraphy and paleoenvironmental significance of a tillite succession in Northern Victoria Land (Antarctica) (United States)

    Cornamusini, Gianluca; Talarico, Franco M.; Cirilli, Simonetta; Spina, Amalia; Olivetti, Valerio; Woo, Jusun


    deposits of Northern Victoria Land record the evolution from a setting characterized by a terrestrial small ice cap that underwent repeated advances and retreats due to climate cycles in a lacustrine setting, into a postglacial paleoenvironmental scenario with a wide fluvial system draining northwards from Victoria Land towards the Tasmanian Basin. The results contribute to increasing knowledge of the timing and modalities of the Late Paleozoic Ice Age in Gondwana, particularly for polar regions such as Antarctica.

  7. IDA: An implicit, parallelizable method for calculating drainage area (United States)

    Richardson, Alan; Hill, Christopher N.; Perron, J. Taylor


    Models of landscape evolution or hydrological processes typically depend on the accurate determination of upslope drainage area from digital elevation data, but such calculations can be very computationally demanding when applied to high-resolution topographic data. To overcome this limitation, we propose calculating drainage area in an implicit, iterative manner using linear solvers. The basis of this method is a recasting of the flow routing problem as a sparse system of linear equations, which can be solved using established computational techniques. This approach is highly parallelizable, enabling data to be spread over multiple computer processors. Good scalability is exhibited, rendering it suitable for contemporary high-performance computing architectures with many processors, such as graphics processing units (GPUs). In addition, the iterative nature of the computational algorithms we use to solve the linear system creates the possibility of accelerating the solution by providing an initial guess, making the method well suited to iterative calculations such as numerical landscape evolution models. We compare this method with a previously proposed parallel drainage area algorithm and present several examples illustrating its advantages, including a continent-scale flow routing calculation at 3 arc sec resolution, improvements to models of fluvial sediment yield, and acceleration of drainage area calculations in a landscape evolution model. We additionally describe a modification that allows the method to be used for parallel basin delineation.

  8. DNA barcoding of schistosome cercariae reveals a novel sub-lineage within Schistosoma rodhaini from Ngamba Island Chimpanzee Sanctuary, Lake Victoria. (United States)

    Standley, C J; Stothard, J R


    While Schistosoma rodhaini is typically considered a parasite of small mammals and is very scantly distributed in the Lake Victoria basin, it is known to hybridize with the more widespread Schistosoma mansoni, the causative agent of intestinal schistosomiasis. As part of broader parasitological and malacological surveys for S. mansoni across Lake Victoria, schistosome cercariae were harvested from a field-caught Biomphalaria choanomphala taken on Ngamba Island Chimpanzee Sanctuary, Uganda. Upon DNA barcoding, these cercariae were found to be a mixture of both S. rodhaini and S. mansoni, with further phylogenetic analysis revealing a hitherto unknown sub-lineage within S. rodhaini. Despite repeated sampling for eggs and miracidia from both chimpanzees and staff on Ngamba Island Sanctuary, detection of S. rodhaini within local definitive hosts awaits additional efforts, which should be mindful of a potential host role of spotted-necked otters.

  9. adequacy of drainage channels f drainage channels in a small

    African Journals Online (AJOL)


    because of the complexity of the process interactive factors involved, but also b stochastic nature of .... Figure 1.0: Map of basin A showing the network of drains and outfalls. Figure 2: Map of basin C showing the network of ... map and this was imported on a Gis based software. (Stormnet modeling software) which shows the.

  10. Technical note on drainage systems

    DEFF Research Database (Denmark)

    Bentzen, Thomas Ruby

    This technical note will present simple but widely used methods for the design of drainage systems. The note will primarily deal with surface water (rainwater) which on a satisfactorily way should be transport into the drainage system. Traditional two types of sewer systems exist: A combined system......’s not major different than described below - just remember to include this contribution for combined systems where the surface water (rain) and sewage are carried in the same pipes in the system and change some of the parameters for failure allowance (this will be elaborated further later on). The technical...

  11. Closed suction drainage versus closed simple drainage in the ...

    African Journals Online (AJOL)

    Objective: To compare the outcome of modified radical mastectomy wounds managed by closed wound drainage with suction and without suction. Methods: A prospective randomized trial was conducted at the University College Hospital Ibadan and University of Nigeria Teaching Hospital Enugu, Nigeria. Fifty women who ...

  12. Macroinvertebrate community response to acid mine drainage in rivers of the High Andes (Bolivia).

    NARCIS (Netherlands)

    Damme, P.A. van; Hamel, C.; Ayala, A.; Bervoets, L.


    Several High Andes Rivers are characterized by inorganic water pollution known as acid mine drainage (AMD). The aim of this study was to assess the relationship between metal concentrations in the sediments and the macroinvertebrate communities in two river basins affected by AMD. In general, the

  13. Nitrate in tile drainage of the semiarid Palouse Basin. (United States)

    Keller, C Kent; Butcher, Caroline N; Smith, Jeffrey L; Allen-King, Richelle M


    Topographically heterogeneous agricultural landscapes can complicate and accelerate agrochemical contamination of streams due to rapid transport of water and chemicals to poorly drained lower-landscape positions and shallow ground water. In the semiarid Palouse region, large parts of these landscapes have been tile drained to enhance crop yield. From 2000-2004 we monitored the discharge of a tile drain (TD) and a nearby profile of soil water for nitrate concentration ([NO(3)]), electrical conductivity level (EC), and water content to develop a conceptual framework describing soil nitrate occurrence and loss via subsurface pathways. Tile-drain baseflow [NO(3)] was consistently 4 mg N L(-1) and baseflow EC was 200 to 300 microS cm(-1). Each year sudden synoptic increases in TD discharge and [NO(3)] occurred in early winter following approximately 150 mm of fall precipitation, which saturated the soil and mobilized high-[NO(3)] soil water throughout the profile. The greatest TD [NO(3)] (20-30 mg N L(-1)) occurred approximately contemporaneous with greatest TD discharges. The EC decrease each year (to approximately 100 microS cm(-1)) during high discharge, a dilution effect, lagged approximately 1 mo behind the first appearance of high [NO(3)] and was consistent with advective transport of low-EC water from the shallow profile under saturated conditions. Water-budget considerations and temporal [NO(3)] patterns suggest that these processes deliver water to the TD from both lower- and upper-slope positions, the latter via lateral flow during the high-flow season. Management practices that reduce the fall reservoir of soil nitrate might be effective in reducing N loading to streams and shallow ground water in this region.

  14. Drainage basin nutrient inputs and eutrophication: an integrated approach


    Wassmann, Paul; Olli, Kalle


    Eutrophication is an increase in primary production due to increased nutrient supply and its consequences. In its widest sense eutrophication means any increase of nutrient availability that increases primary production. Frequently, however, eutrophication is understood exclusively as the consequence of nutrient input by anthropogenic activities. The primary consequence of eutrophication in aquatic environments is an enhancement of algal productivity and accumulation of algal biomass. Seco...

  15. Estimation of recharge through selected drainage wells and potential effects from well closure, Orange County, Florida (United States)

    Bradner, L.A.


    Drainage wells have been used in Orange County, Florida, and surrounding areas to alleviate flooding and to control lake levels since 1904. Over 400 drainage wells have been drilled in the county, but many are now redundant because of surface drainage systems that have been installed within the last two or three decades. Most of the drainage wells emplace water into the Upper Floridan aquifer, a zone of high transmissivity within the Floridan aquifer system. In 1992, the Orange County Stormwater Management Department identified 23 wells that were considered noncritical or redundant for current drainage control. These wells were targeted for closure to eliminate maintenance and possible contamination problems. A 3-year study (1992 through 1994) encompassed several drainage basins in the county. Inflow to 18 of the 23 drainage wells on the noncritical list and the effects of closure of these noncritical wells on the potentiometric surface of the Upper Floridan aquifer were estimated. Three sites were chosen for intensive study and were used for further extrapolation to other noncritical sites. The total average annual recharge rate through the 18 selected wells was estimated to be 9 cubic feet per second, or about 6 million gallons per day. The highest rate of long-term recharge, 4.6 cubic feet per second, was to well H-35. Several wells on the noncritical list were already plugged or had blocked intakes. Yields, or the sum of surface-water outflows and drainage-well recharge, from the drainage basins ranged from 20 to 33 inches per year. In some of the basins, all the yield from the basin was recharge through a drainage well. In other basins, most of the yield was surface outflow through canals rather than to drainage wells. The removal of the recharge from closure of the wells was simulated by superposition in a three-dimensional ground-water flow model. As a second step in the model, water was also applied to two sites in western Orange County that could receive

  16. Definition of the drainage filter problem

    NARCIS (Netherlands)

    Zaslavsky, D.


    It is common to consider the following: I. Retention of soil particles that may enter the drainage pipe and cause its clogging. For some sensitive structures it is important to prevent settlements due to soil transportation by drainage water.

  17. Movimiento superficial de contaminantes biológicos de origen ganadero en la red de drenaje de una cuenca de Pampa Ondulada Surface movement of cattle-borne biological contaminants in the drainage network of a basin of the Rolling Pampas

    Directory of Open Access Journals (Sweden)

    Celio I Chagas


    Full Text Available Se estudió la concentración de indicadores de contaminación biológica en pequeñas depresiones ubicadas en vías de escurrimiento que atraviesan tierras dedicadas a la ganadería donde se acumulan aguas y sedimentos generados por la actividad agropecuaria de la Pampa Ondulada argentina. La carga animal de los lotes ubicados en la cuenca del Tala donde se encontraban las depresiones, se relacionó estrechamente con su carga de microorganismos. La intensidad de las lluvias previas al muestreo (en el caso de los coliformes totales y el lapso de tiempo entre el último escurrimiento significativo y el muestreo (para enterococos y estreptococos fecales resultaron variables sensibles para predecir la dinámica de la concentración de dichos grupos de microorganismos en los sitios de acumulación. Los resultados obtenidos corroboran la estrecha asociación que existe entre los procesos de escurrimiento y erosión hídrica y la contaminación biológica de las aguas acumuladas en las depresiones estudiadas. Estos elementos, sumados a los resultados de trabajos previos realizados en la región, permitieron elaborar un modelo conceptual sencillo de entradas y salidas de potenciales contaminantes físicos y biológicos en las depresiones estudiadas que podrá servir de base para el diseño de alertas tempranas de contaminación de los cursos de agua a nivel regional.Runoff water and sediments from crop and cattle production fields of the Rolling Pampas accumulate in small depressions along the drainage network. We studied the concentration of biological contamination indicators in these small sinks located in bottomlands devoted to cattle production of the Tala River basin. The stocking rate was closely related to the concentration of microorganisms in the depressions. The intensity of rainfall events previous to each sampling date and the time between the last significant runoff event and each sampling date proved to be sensible variables for

  18. Vascular riffle flora of Appalachian streams: the ecology and effects of acid mine drainage on Justificia americana (L. ) Vahl

    Energy Technology Data Exchange (ETDEWEB)

    Koryak, M.; Reilly, R.J.


    Justicia americana is a stout-based colonial plant, abundant in most of the larger, low to moderate gradient streams of the upper Ohio River basin. The distribution of J. americana is related to acid drainage from bituminous coal mining operations in the upper Ohio River drainage basin. Possible fluvial and biological consequences of the colonization or absence of Justicia are considered. Luxuriant growths were noted on gravel bars and riffles of larger, unpolluted streams in the basin. Acid mine drainage severely depresses the growth of the plant, leaving gravel shoals and riffles in the acid streams either barren or dominated by other emergent species. Particular among these new species is Elecocharis acicularis. The elimination of J. americana from suitable habitat adversely affects channel morphology, substrate composition, general aesthetic quality and aquatic stream life in the region. 16 references, 2 figures, 3 tables.

  19. Measles outbreak in young adults in Victoria, 1999. (United States)

    Lambert, S B; Morgan, M L; Riddell, M A; Andrews, R M; Kelly, H A; Leydon, J A; Catton, M C; Lynch, P A; Gercovich, D K; Lester, R A; Carnie, J A; Rouch, G J


    To describe an outbreak of measles in Victoria. Case series with cases identified through enhanced passive surveillance and outbreak-related active surveillance. State of Victoria, 1999. Number of cases; epidemiological links and patterns of transmission; patient demographic features and vaccination status; complications. 75 cases were identified (74 laboratory-confirmed; and one epidemiologically linked to a laboratory-confirmed case), with onset between 11 February and 2 May 1999. The first case was in a 21-year-old woman who had recently holidayed in Bali and worked at a large cinema complex in Melbourne. Sixteen cases occurred in people who had contact with the index case at the cinema on one evening. The outbreak spread to regional Victoria and South Australia. Median age of patients was 22 years; 64 (85%) were born between 1968 and 1981, with only one patient in the age group targeted by the primary school component of the 1998 Australian Measles Control Campaign; this child had not been vaccinated. More than a third of patients (28) were hospitalised (total, 97 inpatient days), and five were healthcare workers. This outbreak was caused by international importation of measles virus. It highlights the change in epidemiology of measles in Australia, from a disease of childhood to one predominantly affecting young adults. A strong two-dose childhood vaccination program, vigilant surveillance, and rapid response to outbreaks will continue to be the basis of measles control, but better protection for young adults should be considered.

  20. 24 CFR 3280.610 - Drainage systems. (United States)


    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Drainage systems. 3280.610 Section... DEVELOPMENT MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS Plumbing Systems § 3280.610 Drainage systems. (a) General. (1) Each fixture directly connected to the drainage system shall be installed with a...

  1. Eustatic and tectonic change effects in the reversion of the transcontinental Amazon River drainage system

    Directory of Open Access Journals (Sweden)

    Mario Vicente Caputo

    Full Text Available ABSTRACT: The development of the transcontinental Amazon River System involved geological events in the Andes Chain; Vaupés, Purus and Gurupá arches; sedimentary basins of the region and sea level changes. The origin and age of this river have been discussed for decades, and many ideas have been proposed, including those pertaining to it having originated in the Holocene, Pleistocene, Pliocene, Late Miocene, or even earlier times. Under this context, the geology of the sedimentary basins of northern Brazil has been analyzed from the Mesozoic time on, and some clarifications are placed on its stratigraphy. Vaupés Arch, in Colombia, was uplifted together with the Andean Mountains in the Middle Miocene time. In the Cenozoic Era, the Purus Arch has not blocked this drainage system westward to marine basins of Western South America or eastward to the Atlantic Ocean. Also the Gurupá Arch remained high up to the end of Middle Miocene, directing this drainage system westward. With the late subsidence and breaching of the Gurupá Arch and a major fall in sea level, at the beginning of the Late Miocene, the Amazon River quickly opened its pathway to the west, from the Marajó Basin, through deep headward erosion, capturing a vast drainage network from cratonic and Andean areas, which had previously been diverted towards the Caribbean Sea. During this time, the large siliciclastic influx to the Amazon Mouth (Foz do Amazonas Basin and its fan increased, due to erosion of large tracts of South America, linking the Amazon drainage network to that of the Marajó Basin. This extensive exposure originated the Late Miocene (Tortonian unconformity, which marks the onset of the transcontinental Amazon River flowing into the Atlantic Ocean.

  2. Curling into the hole: drainage evolution at the edge of a sinking slab (Guadalhorce River, westernmost Mediterranean) (United States)

    Pérez Peña, José Vicente; Booth Rea, Guillermo; Azañón, José Miguel; Morales, José; de Lis Mancilla, Flor; Stich, Daniel; Galve, Jorge Pedro


    Dynamic topography related to mantle processes is an important factor controlling landscape and drainage network evolution. Dense slabs induce an upper mantle flow that deflects the topography downward above them. Topographic anomalies caused by these mechanisms have a long-wavelength and normally remain masked by other tectonic mechanisms that deform the surface at smaller wavelengths. Therefore, the geomorphic evidence of these mantle mechanisms are not so frequent in active orogens. In the central Betics (westernmost Mediterranean), sharp differences in crustal thickness do not match with topographic gradients, thus necessitating support by mantle-related mechanisms. In this work we analyzed the topographic and drainage network evolution of the Guadalhorce drainage basin, located in the central Betics. The northern part of this basin was captured in Pleistocene times following a very distinctive radial pattern. The main channels in the north deviate into the Malaga basin depicting sharp U-turns. High-resolution crustal imaging by P-receiver functions allows us to identify a bend of the Iberian Moho at the top of the Alboran sinking slab. Different topography filters at different wavelengths show a long-scale topographic depression that lies above the Iberian Moho bend. The central and middle part of the basin lies over this depression and the drainage network flows orthogonal to the main gradient of the Iberian Moho. Therefore, the Alboran sinking slab produces a negative dynamic topography that is curling the drainage network towards it.

  3. Nutrient behaviour in urban drainages


    Choy, David Kam Wai


    Urbanisation has altered the natural landscape, removing features that previously acted to retain, transform and process nitrogen and phosphorus within catchments. In Melbourne the past legacy of traditional urban design aimed at efficient drainage of stormwater has resulted in higher stormwater volumes with high pollutant concentrations. Excessive concentrations of such nutrients in urban runoff can have an adverse impact on the ecological health of receiving waters. The aims of this stu...

  4. Exploring Agricultural Drainage's Influence on Wetland and ... (United States)

    Artificial agricultural drainage (i.e. surface ditches or subsurface tile) is an important agricultural management tool. Artificial drainage allows for timely fieldwork and adequate root aeration, resulting in greater crop yields for farmers. This practice is widespread throughout many regions of the United States and the network of artificial drainage is especially extensive in flat, poorly-drained regions like the glaciated Midwest. While beneficial for crop yields, agricultural drains often empty into streams within the natural drainage system. The increased network connectivity may lead to greater contributing area for watersheds, altered hydrology and increased conveyance of pollutants into natural water bodies. While studies and models at broader scales have implicated artificial drainage as an important driver of hydrological shifts and eutrophication, the actual spatial extent of artificial drainage is poorly known. Consequently, metrics of wetland and watershed connectivity within agricultural regions often fail to explicitly include artificial drainage. We use recent agricultural census data, soil drainage data, and land cover data to create estimates of potential agricultural drainage across the United States. We estimate that agricultural drainage in the US is greater than 31 million hectares and is concentrated in the upper Midwest Corn Belt, covering greater than 50% of available land for 114 counties. Estimated drainage values for numerous countie

  5. National water-quality assessment program : the Albemarle- Pamlico drainage (United States)

    Lloyd, O.B.; Barnes, C.R.; Woodside, M.D.


    In 1991, the U.S. Geological Survey (USGS) began to implement a full-scale National Water-Quality Assessment (NAWQA) program. Long-term goals of the NAWQA program are to describe the status and trends in the quality of a large, representative part of the Nation's surface- and ground-water resources and to provide a sound, scientific understanding of the primary natural and human factors affecting the quality of these resources. In meeting these goals, the program will produce a wealth of water quality information that will be useful to policy makers and managers at the national, State, and local levels. Study-unit investigations constitute a major component of the NAWQA program, forming the principal building blocks on which national-level assessment activities are based. The 60 study-unit investigations that make up the program are hydrologic systems that include parts of most major river basins and aquifer systems. These study units cover areas of 1,200 to more than 65,000 square miles and incorporate about 60 to 70 percent of the Nation's water use and population served by public water supply. In 1991, the Albemarle-Pamlico drainage was among the first 20 NAWQA study units selected for study under the full-scale implementation plan. The Albemarle-Pamlico drainage study will examine the physical, chemical, and biological aspects of water quality issues in a coordinated investigation of surface water and ground water in the Albemarle-Pamlico drainage basin. The quantity and quality of discharge from the Albemarle-Pamlico drainage basin contribute to some water quality problems in the biologically sensitive waters of Albemarle and Pamlico Sounds. A retrospective analysis of existing water quality data will precede a 3-year period of intensive data-collection and analysis activities. The data resulting from this study and the improved understanding of important processes and issues in the upstream part of the study unit will enhance understanding of the quality of

  6. An examination of injection drug use trends in Victoria and Vancouver, BC after the closure of Victoria's only fixed-site needle and syringe programme. (United States)

    Ivsins, Andrew; Chow, Clifton; Macdonald, Scott; Stockwell, Tim; Vallance, Kate; Marsh, David C; Michelow, Warren; Duff, Cameron


    Needle and syringe programmes (NSPs) have been established as effective harm reduction initiatives to reduce injection drug use (IDU)-related risk behaviours, including sharing needles. On May 31, 2008, Victoria, BC's only fixed site NSP was shut down due to community and political pressure. This study examines and compares IDU trends in Victoria with those in Vancouver, BC, a city which has not experienced any similar disruption of IDU-related public health measures. Quantitative and qualitative data were collected by interviewer-administered questionnaires conducted with injection drug users (n=579) in Victoria and Vancouver between late 2007 and late 2010. Needle sharing increased in Victoria from under 10% in early 2008 to 20% in late 2010, whilst rates remained relatively low in Vancouver. Participants in Victoria were significantly more likely to share needles than participants in Vancouver. Qualitative data collected in Victoria highlight the difficulty participants have experienced obtaining clean needles since the NSP closed. Recent injection of crack cocaine was independently associated with needle sharing. The closure of Victoria's fixed site NSP has likely resulted in increased engagement in high-risk behaviours, specifically needle sharing. Our findings highlight the contribution of NSPs as an essential public health measure. Copyright © 2011 Elsevier B.V. All rights reserved.

  7. Morphometric analysis of the Marmara Sea river basins, Turkey (United States)

    Elbaşı, Emre; Ozdemir, Hasan


    The drainage basin, the fundamental unit of the fluvial landscape, has been focus of research aimed at understanding the geometric characteristics of the master channel and its tributary network. This geometry is referred to as the basin morphometry and is nicely reviewed by Abrahams (1984). A great amount of research has focused on geometric characteristic of drainage basins, including the topology of the stream networks, and quantitative description of drainage texture, pattern, shape, and relief characteristics. Evaluation of morphometric parameters necessitates the analysis of various drainage parameters such as ordering of the various streams, measurement of basin area and perimeter, length of drainage channels, drainage density (Dd), stream frequency (Fs), bifurcation ratio (Rb), texture ratio (T), basin relief (Bh), Ruggedness number (Rn), time of concentration (Tc), hypsometric curve and integral (Hc and Hi) (Horton, 1932, Schumn, 1956, Strahler, 1957; Verstappen 1983; Keller and Pinter, 2002; Ozdemir and Bird, 2009). These morphometric parameters have generally been used to predict flood peaks, to assess sediment yield, and to estimate erosion rates in the basins. River basins of the Marmara Sea, has an area of approximately 40,000 sqkm, are the most important basins in Turkey based on their dense populations, industry and transportation systems. The primary aim of this study is to determine and analyse of morphometric characteristics of the Marmara Sea river basins using 10 m resolution Digital Elevation Model (DEM) and to evaluate of the results. For these purposes, digital 10 m contour maps scaled 1:25000 and geological maps scaled 1:100000 were used as the main data sources in the study. 10 m resolution DEM data were created using the contour maps and then drainage networks and their watersheds were extracted using D8 pour point model. Finally, linear, areal and relief morphometries were applied to the river basins using Geographic Information Systems

  8. Drainage network extraction from a high-resolution DEM using parallel programming in the .NET Framework (United States)

    Du, Chao; Ye, Aizhong; Gan, Yanjun; You, Jinjun; Duan, Qinyun; Ma, Feng; Hou, Jingwen


    High-resolution Digital Elevation Models (DEMs) can be used to extract high-accuracy prerequisite drainage networks. A higher resolution represents a larger number of grids. With an increase in the number of grids, the flow direction determination will require substantial computer resources and computing time. Parallel computing is a feasible method with which to resolve this problem. In this paper, we proposed a parallel programming method within the .NET Framework with a C# Compiler in a Windows environment. The basin is divided into sub-basins, and subsequently the different sub-basins operate on multiple threads concurrently to calculate flow directions. The method was applied to calculate the flow direction of the Yellow River basin from 3 arc-second resolution SRTM DEM. Drainage networks were extracted and compared with HydroSHEDS river network to assess their accuracy. The results demonstrate that this method can calculate the flow direction from high-resolution DEMs efficiently and extract high-precision continuous drainage networks.

  9. Increasing deaths involving oxycodone, Victoria, Australia, 2000-09. (United States)

    Rintoul, Angela C; Dobbin, Malcolm D H; Drummer, Olaf H; Ozanne-Smith, Joan


    In light of an emerging epidemic identified in the United States and Canada, to identify trends in fatal drug toxicity involving oxycodone and the demographic characteristics and indicators of socioeconomic disadvantage of the deceased. Population-based observational study in Victoria, Australia. Decedents whose death was reported to the Victorian Coroner between 2000 and 2009 and where oxycodone was detected. Association between supply of oxycodone and deaths. Demographic characteristics of decedents. Rate ratios of the rural or metropolitan location and socioeconomic indicators of disadvantage of the deceased. Supply to Victoria has increased nine-fold from 7.5 mg per capita in 2000 to 67.5 mg per capita in 2009. Detection of oxycodone in deaths reported to the Victorian Coroner has increased from 4 (0.08/100,000 population) in 2000 to 97 (1.78/100,000 population) in 2009-a 21-fold increase in deaths. Of the 320 cases described, 53.8% (172) were the result of drug toxicity. Of these, 52.3% were unintentional and 19.8% intentional self-harm; the remaining 27.9% are either still under investigation by the coroner or intent is unknown. Drug toxicity deaths were overrepresented in both rural areas and areas indexed with high levels of disadvantage. The substantial increase in the number of deaths involving oxycodone is strongly and significantly associated with the increase in supply. Most drug toxicity deaths involving oxycodone were unintentional. This newly identified trend in fatalities in Victoria supports concerns that a pattern of increasing deaths involving oxycodone is emerging globally.

  10. Organochlorine pesticides in fishes and sediments from the Tensas River Basin, Lousiana (United States)

    US Fish and Wildlife Service, Department of the Interior — The aquatic habitats of the Tensas River Basin in northeastern Louisiana have been heavily impacted by sediment and agrichemical runoff due to intensive drainage,...

  11. Reforming Victoria's primary health and community service sector: rural implications. (United States)

    Alford, K


    In 1999 the Victorian primary care and community support system began a process of substantial reform, involving purchasing reforms and a contested selection process between providers in large catchment areas across the State. The Liberal Government's electoral defeat in September 1999 led to a review of these reforms. This paper questions the reforms from a rural perspective. They were based on a generic template that did not consider rural-urban differences in health needs or other differences including socio-economic status, and may have reinforced if not aggravated rural-urban differences in the quality of and access to primary health care in Victoria.

  12. Exploration of Victoria crater by the mars rover opportunity (United States)

    Squyres, S. W.; Knoll, A.H.; Arvidson, R. E.; Ashley, James W.; Bell, J.F.; Calvin, W.M.; Christensen, P.R.; Clark, B. C.; Cohen, B. A.; De Souza, P.A.; Edgar, L.; Farrand, W. H.; Fleischer, I.; Gellert, Ralf; Golombek, M.P.; Grant, J.; Grotzinger, J.; Hayes, A.; Herkenhoff, K. E.; Johnson, J. R.; Jolliff, B.; Klingelhofer, G.; Knudson, A.; Li, R.; McCoy, T.J.; McLennan, S.M.; Ming, D. W.; Mittlefehldt, D. W.; Morris, R.V.; Rice, J. W.; Schroder, C.; Sullivan, R.J.; Yen, A.; Yingst, R.A.


    The Mars rover Opportunity has explored Victoria crater, a ???750-meter eroded impact crater formed in sulfate-rich sedimentary rocks. Impact-related stratigraphy is preserved in the crater walls, and meteoritic debris is present near the crater rim. The size of hematite-rich concretions decreases up-section, documenting variation in the intensity of groundwater processes. Layering in the crater walls preserves evidence of ancient wind-blown dunes. Compositional variations with depth mimic those ???6 kilometers to the north and demonstrate that water-induced alteration at Meridiani Planum was regional in scope.

  13. An investigation of basin effects on flood discharges in North Dakota (United States)

    Crosby, Orlo A.


    An investigation of the relationship of peak discharge to causative storm variables and drainage-basin characteristics was made to provide guidelines for future analyses of frequency and magnitudes of floods from small drainage areas. The procedure used was (l) to estimate peak discharges on the ll study basins from multiple-regression models developed from the storm variables and (2) to relate the peak discharges to the basin characteristics through regression or correlation with particular attention given to the effect of basin shape.

  14. Basin Assessment Spatial Planning Platform

    Energy Technology Data Exchange (ETDEWEB)


    The tool is intended to facilitate hydropower development and water resource planning by improving synthesis and interpretation of disparate spatial datasets that are considered in development actions (e.g., hydrological characteristics, environmentally and culturally sensitive areas, existing or proposed water power resources, climate-informed forecasts). The tool enables this capability by providing a unique framework for assimilating, relating, summarizing, and visualizing disparate spatial data through the use of spatial aggregation techniques, relational geodatabase platforms, and an interactive web-based Geographic Information Systems (GIS). Data are aggregated and related based on shared intersections with a common spatial unit; in this case, industry-standard hydrologic drainage areas for the U.S. (National Hydrography Dataset) are used as the spatial unit to associate planning data. This process is performed using all available scalar delineations of drainage areas (i.e., region, sub-region, basin, sub-basin, watershed, sub-watershed, catchment) to create spatially hierarchical relationships among planning data and drainages. These entity-relationships are stored in a relational geodatabase that provides back-end structure to the web GIS and its widgets. The full technology stack was built using all open-source software in modern programming languages. Interactive widgets that function within the viewport are also compatible with all modern browsers.

  15. Simulated Water-Management Alternatives Using the Modular Modeling System for the Methow River Basin, Washington (United States)


    represented 16 surface-water diversions to irrigation canals, canal seepage, application of water to agricultural fields, and ET and infiltration of...parameters (table 1) were modified in 36 HRUs representing the drainage basins for Andrews, Lake, Little Bridge, and Buttermilk Creeks. The Andrews Creek...and Lake Creek Basins constitute 12 percent (62 of 525 square miles) of the Chewuch River Basin, and Little Bridge and Buttermilk Creek Basins

  16. Mine Drainage Generation and Control Options. (United States)

    Wei, Xinchao; Rodak, Carolyn M; Zhang, Shicheng; Han, Yuexin; Wolfe, F Andrew


    This review provides a snapshot of papers published in 2015 relevant to the topic of mine drainage generation and control options. The review is broken into 3 sections: Generation, Prediction and Prevention, and Treatment Options. The first section, mine drainage generation, focuses on the characterization of mine drainage and the environmental impacts. As such, it is broken into three subsections focused on microbiological characterization, physiochemical characterization, and environmental impacts. The second section of the review is divided into two subsections focused on either the prediction or prevention of acid mine drainage. The final section focuses on treatment options for mine drainage and waste sludge. The third section contains subsections on passive treatment, biological treatment, physiochemical treatment, and a new subsection on beneficial uses for mine drainage and treatment wastes.

  17. Eesti NATO Ühing juurutab demokraatlikke väärtusi / Victoria Punga ; interv. Aive Antsov

    Index Scriptorium Estoniae

    Punga, Victoria, 1977-


    Eesti NATO Ühingu tegevjuht organisatsiooni eesmärkidest, projektidest, koostööst teiste riikidega ning kaitsepoliitika ja majanduse seostest. Lisa: Väljavõte Victoria CVst; Eesti kaitsepoliitika viis plussi Victoria meelest

  18. A Snapshot: Multicultural Music Teaching in Schools in Victoria, Australia, Portrayed by School Teachers (United States)

    Nethsinghe, Rohan Nishantha


    Due to the changing demographic factors and as demanded by the governmental policies and regulations, schools in Victoria, Australia, are expected to foster multicultural educational programs that address the diverse needs of students. Research has found that school teachers in Victoria struggle to provide the aspired to multicultural education…

  19. Victoria suudlus teeb maapoisist printsi, kuid mitte tulevase kuninga / Kaivo Kopli

    Index Scriptorium Estoniae

    Kopli, Kaivo


    Printsess Victoria tulevasest abikaasast Daniel Westlingist, printsess Madelaine'i kihluse lõpetamisest, Bernadotte'ide dünastia asutajast Jean Bernadotte'ist. Monarhia toetajate vähenemisest Rootsis. Printsess Victoria ja Daniel Westlingi pulmatseremooniast 19. juunil

  20. The Hack's law applied to young volcanic basin: the Tahiti case (United States)

    Ye, F.; Sichoix, L.; Barriot, J.; Serafini, J.


    We study the channel morphology over the Tahiti island from the Hack’s law perspective. The Hack’s law is an empirical power relationship between basin drainage area and the length of its main channel. It had also been shown that drainage area becomes more elongate with increasing basin size. For typical continental basins, the exponent value lies between 0.47 for basins larger than 260,000 km2 and 0.7 for those spanning less than 20,720 km2 (Muller, 1973). In Tahiti, we extracted 27 principal basins ranging from 7 km2 to 90 km2 from a Digital Terrain Model of the island with a 5 m-resolution. We demonstrate that the Hack’s law still apply for such small basins (correlation coefficient R2=0.7) with an exponent value being approximately 0.5. It appears that the exponent value is influenced by the local geomorphic condition, and does not follow the previous study results (the exponent value decreases with increasing drainage area.) Our exponent value matches the result found w.r.t. debris-flow basins of China for drainage areas less than 100 km2 (Li et al., 2008). Otherwise, the young volcanic basins of Tahiti do not become longer and narrower with increasing basin size (R2=0.1). Besides, there is no correlation between the basin area and the basin convexity (R2=0). This means that there is no statistical change in basin shape with basin size. We present also the drainage area-slope relationship with respect to sediment or transport-limited processes. Key words: Hack’s law, channel morphology, DTM

  1. Composite fibrous glaucoma drainage implant (United States)

    Klapstova, A.; Horakova, J.; Shynkarenko, A.; Lukas, D.


    Glaucoma is a frequent reason of loss vision. It is usually caused by increased intraocular pressure leading to damage of optic nerve head. This work deals with the development of fibrous structure suitable for glaucoma drainage implants (GDI). Commercially produced metallic glaucoma implants are very effective in lowering intraocular pressure. However, these implants may cause adverse events such as damage to adjacent tissue, fibrosis, hypotony or many others [1]. The aim of this study is to reduce undesirable properties of currently produced drains and improve their properties by creating of the composite fibrous drain for achieve a normal intraocular pressure. Two types of electrospinning technologies were used for the production of very small tubular implants. First type was focused for production of outer part of tubular drain and the second type of electrospinning method made the inner part of shape follows the connections of both parts. Complete implant had a special properties suitable for drainage of fluid. Morphological parameters, liquid transport tests and in-vitro cell adhesion tests were detected.

  2. An examination of the selenium nutrition of sheep in Victoria. (United States)

    Caple, I W; Andrewartha, K A; Edwards, S J; Halpin, C G


    The selenium nutrition of sheep throughout Victoria was assessed by a survey of the blood glutathione peroxidase activity in 708 flocks. It was shown that the blood glutathione peroxidase activity in sheep had a seasonal variation with lowest levels in the spring. The enzyme activity was correlated with the blood selenium concentration. Areas where blood selenium was less than 0.03 micrograms/ml in spring were defined. Sheep with low selenium nutrition were grazing pastures in the high rainfall areas on acid soils, particularly those derived from granite. Selenium concentrations in pasture samples examined were greater than 0.02 mg/kg, and it was found that superphosphate application had no significant effect on the selenium content of pasture. However, management practices such as high stocking rates and rates of application of superphosphate to pasture were associated with low blood glutathione peroxidase activities in sheep. It was concluded that the selenium nutrition of most of the sheep flocks in Victoria is adequate, and that the deficient areas are localised. There seems little requirement for supplementation of adult sheep. As the delayed type of white muscle disease in spring lambs appears to be the main selenium-responsive disorder, direct supplementation of lambs in the low selenium areas would be the most effective method of ensuring adequate selenium nutrition.

  3. Epidemiology of the 2012 influenza season in Victoria, Australia

    Directory of Open Access Journals (Sweden)

    James Fielding


    Full Text Available Objective: To assess the magnitude and severity of the 2012 influenza season in Victoria, Australia using surveillance data from five sources. Methods: Data from influenza notifications, sentinel general practices, a sentinel hospital network, a sentinel locum service and strain typing databases for 2012 were descriptively analysed. Results: Influenza and influenza-like illness activity was moderate compared to previous years, although a considerable increase in notified laboratory-confirmed influenza was observed. Type A influenza comprised between 83% and 87% of cases from the general practitioners, hospitals and notifiable surveillance data. Influenza A/H3 was dominant in July and August, and most tested isolates were antigenically similar to the A/Perth/16/2009 virus used in the vaccine. There was a smaller peak of influenza type B in September. No tested viruses were resistant to any neuraminidase inhibitor antivirals. Higher proportions of type A/H3, hospitalized cases and those with a comorbid condition indicated for influenza vaccination were aged 65 years or older. Influenza vaccination coverage among influenza-like illness patients was 24% in sentinel general practices and 50% in hospitals. Discussion: The 2012 influenza season in Victoria was average compared to previous years, with an increased dominance of A/H3 accompanied by increases in older and hospitalized cases. Differences in magnitude and the epidemiological profile of cases detected by the different data sources demonstrate the importance of using a range of surveillance data to assess the relative severity of influenza seasons.

  4. Comprehensive nursing education in Victoria: rhetoric or reality? (United States)

    Happell, B


    Significant and widespread changes to the education of the psychiatric nursing workforce in Victoria, Australia are resulting in serious problems in the recruitment of new nursing staff. In reviewing the available literature, it is evident that undergraduate nursing students do not commence their educational program with a strong interest in pursuing a career in psychiatric nursing. In light of this knowledge, the role of education in providing a comprehensive view of the nursing profession becomes paramount. Research investigating the impact of education on the attitudes of students to psychiatric nursing as a career option has produced mixed and often inconclusive results. A longitudinal study was undertaken in Victoria, Australia. Students of the majority of universities in which undergraduate nursing programs were operating participated in this study. The participants were asked to rank nine areas of nursing specialty in order of preference at the commencement and immediately prior to the completion of the nursing program. Despite a significant improvement in the popularity of psychiatric nursing as a career choice, this area was ranked at number 8 at both pre- and post-program test. The analysis of open-ended questions demonstrated a marked change in the overall attitudes towards the mentally ill and psychiatric nursing.


    Directory of Open Access Journals (Sweden)

    Parmonangan Manurung


    Full Text Available Victoria Park is the largest city park in Hong Kong. This city park is not only known in Hong Kong, but also very well known in Indonesia as a gathering place for Indonesia domestic helpers (TKW in Hong Kong. This research tried to find out some determinant factors that have been affected the public open spac of Victoria Park to be a gathering place for thousands of TKW in Sunday and holidays as their day off. In order to get the results of research, some methodological research had been conducted such as: observation (survey, mapping, interviews and literature studies. The results showed that Victoria Park has a number of factors capable of meeting the needs of domestic help-ers in Hong Kong, these factors consist of internal factors and external factors. Internally, the character and functions held Victoria Park became a very influential factor, while externally, the accessibility and support functions around Victoria Park also has a considerable influence.

  6. Quaternary Faults and Basin-fill Sediments of the Las Vegas Basin, Southern Nevada (United States)

    Taylor, W. J.; Fossett, E.; Luke, B.; Snelson, C.; Rasmussen, T.; McCallen, D.; Rodgers, A.; Louie, J.


    The N-S elongated extensional Las Vegas basin, southern Nevada, contains 100's of meters of Cenozoic basin-fill sediments that are cut by several Quaternary (Q) faults. These faults define or influence the basin geometry. The basin is generally an asymmetrical half graben defined by the W-dipping, Q Frenchman Mountain fault (FMF) along its E side and a series of smaller offset E-dipping faults to the W. The N terminus of the basin is controlled by the Las Vegas Valley shear zone, along which the majority of the offset occurred prior to the Q. Here, we asses the influence of the Q faults on the distribution of the sedimentary units. Well, exposure, seismic reflection and seismic refraction data show that sedimentary units of different grain sizes or seismic velocity dominate different parts of the basin. Sections dominated by coarse clastic deposits occupy a narrow area along the E side of the basin. Coarse clastic sediments are mixed with finer grained sediments in a broader area along the W side of the basin. Based on provenance and alluvial fan distribution, the coarse deposits along the E side of the basin appear to be trapped in close proximity to the W-dipping FMF. The coarse-grained deposits along the opposite, W side of the basin, are sourced from the nearby Spring Mountains. Because of the structural asymmetry of the basin, these sediments traveled farther from their source area than those on the E side. Some of these E-dipping faults influence the depth to Paleozoic bedrock and some faults form small sub-basins filled with finer grained sediments. Along a WNW trend near the center of the basin and near the present-day Las Vegas Wash, a change in the grain size distribution occurs up stratgraphic section: continuous clay layers are less common and coarse-grained deposits are more common. This difference may reflect a change from internal drainage early in the basin history to external drainage through the Las Vegas Wash in the latter history of the basin

  7. Case study of fault survey based on drainage system analysis in Uljin area of Korean Peninsula (United States)

    Choi, Sung-Ja; Han, Jong-kyu


    DEM (Digital Elevation Model) produced by digital topographic map and satellite image have been utilized for geologic survey. This study aims to clarify the relationship between a knickpoint and faults in Namdae stream by the analysis of the digital elevation model. Namdae drainage basin is divided into three subbasins of S1, S2 and S3 of which knickpoints extracted from the digital elevation model developed on the middle to mid-upper region of the subbasins. Relative steepness Ks depending on deepening rate and concavity θ of basins is higher in S1 region than S2 and S3 regions. I assume the deepening rate caused by active erosion is resulted from the several faults crossing the basins rather than difference of rock types. The knickpoint of the NamDae drainage area which included low-ranking branch is all 77, 24 of which are on the main river system S1, S2, S3. 27 of 77 knickpoints are matched the faults (38%), and 13 knickpoints from three basins corresponds with the faults (54%). It indicates the knickpoints on the basins are closely connected with the faults. For example, relative steepness Ksn is 38.8 on average, but is 42.99 ~ 43.39 in the overlapping area of Samdang and Duchun faults , even considering the elevation above sea level. We suggest the faults cause the knickpoint of high Ksn like as a geomorphic deformation. As comparing the knickpoints and rock boundaries, there are little evidence of relationship between them, while 54 % of the knickpoints distribute on the subbasins S1, S2, and S3. We conclude the knickpoints of a drainage basin the fault movement results in are one of the geomorphological deformations and useful for survey of the Quaternary faults or for extension of the faults.

  8. Characteristics of Drainage Divide Migration through Coseismic and Storm-Triggered Landslides (United States)

    Dahlquist, M. P.; West, A. J.; Li, G.


    Drainage basin reorganization is a fundamental but poorly understood process in landscape evolution. Capture and loss of drainage area by rivers redistributes erosive power and can drive the response of a landscape to tectonic/climatic forcing. Evidence of discrete capture of tributaries is widespread and common, but study of gradual migration of divides by hillslope processes (e.g. landsliding) has been minimal. Much scholarship is devoted to the geometric characteristics of rivers as they respond to tectonic forces, and divide migration has been proposed to result from contrasts in fluvial channel form. However, fluvial processes do not extend to basin divides, so fluvial controls on drainage reorganization should be mediated by hillslope processes such as slope failure. Here we explore whether the mediating role of hillslopes can be observed over the timescale of a single earthquake or major storm. We examine landslides in steep landscapes caused by three major events in the past decade: the 2008 Mw 7.9 Wenchuan earthquake in Sichuan, China, the 2009 Typhoon Morakot in Taiwan, and the 2015 Mw 7.8 Gorkha earthquake in Nepal. These events generated landslides that cut off ridges, causing area gain and loss in the drainage basins outlined by those ridges. We compare the location of these ridge-cutting landslides to values of Χ, an integral value of upstream drainage area over the length of a river. Comparing the Χ values of rivers which share a drainage divide is thought to show which river is likely to gain area at the expense of the other as the divide migrates, defining an "aggressor" (smaller Χ at divide) and a "victim" (greater Χ). We compute Χ for the rivers draining ridge-cutting landslides and consider whether landslides favor drainage area gain in basins with lower X values. Our preliminary results suggest that divide migration in areas with small to moderate disparities in Χ appears to be stochastic, with divides frequently migrating in the opposite

  9. Ecological distribution of stream macroalgal communities from a drainage basin in the Serra da Canastra National Park, Minas Gerais, Southeastern Brazil Distribuição de macroalgas lóticas de uma bacia de drenagem no Parque Nacional da Serra da Canastra, Minas Gerais, Brasil

    Directory of Open Access Journals (Sweden)

    O. Necchi-Júnior


    Full Text Available Twelve stream segments were sampled four times in 1998-1999 (one sampling per season in the drainage basin of the upper São Francisco River (19º45'-21º25'S, 49º05'-51º30'W, situated in Serra da Canastra National Park, at altitudes ranging from 1,175 to 1,400 m. The macroalgae survey resulted in 30 species, with a predominance of Cyanophyta (12 species = 40% and Chlorophyta (11 species = 36.5% and a lower proportion of Rhodophyta (seven species = 23.5%. Two species, Klebsormidium rivulare (Chlorophyta and Kyliniella latvica (Rhodophyta, were new records for Brazil. Capsosira sp. and Stigonema sp. (Cyanophyta and the "Chantransia" stage of Batrachospermum (Rhodophyta were the most widespread macroalgae, occurring in six sampling sites, whereas 11 species were found at only one site. The proportion of macroalgal morphological types were as follows: mats (33%, free filaments (27%, gelatinous filaments (27%, crusts (7%, tufts (3%, and gelatinous colonies (3%. The flora revealed few species in common (4%-8% with stream macroalgae from other Brazilian regions. The macroalgal communities proved to have species richness values close to the highest values reported in previous studies. The patterns typical for stream macroalgal communities (patchy distribution and dominance of few species were also found in this basin. However, the stream variables most influential in macroalgal distribution in this study (rocky substratum, low pH, high COD, water color, and current velocity were essentially the same that best describe the limnological characteristics of this lotic ecosystem. In addition, this combination of variables differed sharply from results of previous studies in other Brazilian stream ecosystems.Doze segmentos de riachos foram amostrados quatro vezes em 1998-1999 (uma amostragem em cada estação na bacia de drenagem do alto rio São Francisco (19º45'-21º25'S, 49º05'-51º30'W, situado no Parque Nacional da Serra da Canastra, em altitudes de

  10. Urban drainage control applying rational method and geographic information technologies (United States)

    Aldalur, Beatriz; Campo, Alicia; Fernández, Sandra


    The objective of this study is to develop a method of controlling urban drainages in the town of Ingeniero White motivated by the problems arising as a result of floods, water logging and the combination of southeasterly and high tides. A Rational Method was applied to control urban watersheds and used tools of Geographic Information Technology (GIT). A Geographic Information System was developed on the basis of 28 panchromatic aerial photographs of 2005. They were georeferenced with control points measured with Global Positioning Systems (basin: 6 km2). Flow rates of basins and sub-basins were calculated and it was verified that the existing open channels have a low slope with the presence of permanent water and generate stagnation of water favored by the presence of trash. It is proposed for the output of storm drains, the use of an existing channel to evacuate the flow. The solution proposed in this work is complemented by the placement of three pumping stations: one on a channel to drain rain water which will allow the drain of the excess water from the lower area where is located the Ingeniero White city and the two others that will drain the excess liquid from the port area.

  11. Performance of DRAINWAT model in assessing the drainage discharge from a small watershed in the Po Valley (Northern Italy) (United States)

    Maurizio Borin; Tomaso Bisol; Devendra M. Amatya


    The performance of DRAINWAT, a DRAINMOD based-watershed scale hydrology model, in predicting the water discharge was assessed in a small basin in Northern Italy during 2002-2005. DRAINWAT slightly unpredicted (4%) the total stream drainage flow respect the measured data (549 mm), in calibration (2002-04). The underprediction was 11% in 2004-05 validation period, when...

  12. Landscape aridity, fire severity and rainfall intensity as controls on debris flow frequency after the 2009 Black Saturday Wildfires in Victoria (United States)

    Nyman, Petter; Sherwin, Christopher; Sheridan, Gary; Lane, Patrick


    This study uses aerial imagery and field surveys to develop a statistical model for determining debris flow susceptibility in a landscape with variable terrain, soil and vegetation properties. A measure of landscape scale debris flow response was obtained by recording all debris flow affected drainage lines in the first year after fire in a ~258 000 ha forested area that was burned by the 2009 Black Saturday Wildfire in Victoria. A total of 12 500 points along the drainage network were sampled from catchments ranging in size from 0.0001 km2to 75 km2. Local slope and the attributes of the drainage areas (including the spatially averaged peak intensity) were extracted for each sample point. A logistic regression was used to model how debris flow susceptibility varies with the normalised burn ratio (dNBR, from Landsat imagery), rainfall intensity (from rainfall radar), slope (from DEM) and aridity (from long-term radiation, temperature and rainfall data).The model of debris flow susceptibility produced a good fit with the observed debris flow response of drainage networks within the burned area and was reliable in distinguishing between drainage lines which produced debris flows and those which didn't. The performance of the models was tested through multiple iterations of fitting and testing using unseen data. The local channel slope captured the effect of scale on debris flow susceptibility with debris flow probability approaching zero as the channel slope decreased with increasing drainage area. Aridity emerged as an important predictor of debris flow susceptibility, with increased likelihood of debris flows in drier parts of the landscape, thus reinforcing previous research in the region showing that post-fire surface runoff from wet Eucalypt forests is insufficient for initiating debris flows. Fire severity, measured as dNBR, was also a very important predictor. The inclusion of local channel slope as a predictor of debris flow susceptibility proved to be an

  13. Lunnyu soils in the Lake Victoria basin of Uganda: Link to ...

    African Journals Online (AJOL)


    1Department of Forest Biology and Ecosystems Management, Faculty of Forestry and Nature Conservation, ... average annual temperature is 21.5°C (Komutunga and Musiitwa, ...... storage prediction in temperate hydromorphic soils using a.

  14. Integrated Climate Change Impact Assessment and Extreme Event Forecasting in the Lake Victoria Basin (LVB)


    Mutua, Felix Nzive


    Extreme weather events have been the leading cause of disasters and damage all over the world. Recent events have led to mass displacement, loss of income, and hampered access to clean water and health to many. The primary ingredient to these disasters especially floods is rainfall which over the years, despite advances in modeling, computing power and use of new data and technologies, has proven to be difficult to predict. Numerical weather prediction (NWP) and climate models using global fo...

  15. Inter-Event Time Definition Setting Procedure for Urban Drainage Systems

    Directory of Open Access Journals (Sweden)

    Jingul Joo


    Full Text Available Traditional inter-event time definition (IETD estimate methodologies generally take into account only rainfall characteristics and not drainage basin characteristics. Therefore, they may not succeed in providing an appropriate value of IETD for any sort of application to the design of urban drainage system devices. To overcome this limitation, this study presents a method of IETD determination that considers basin characteristics. The suggested definition of IETD is the time period from the end of a rainfall event to the end of a direct runoff. The suggested method can identify the independent events that are suitable for the statistical analysis of the recorded rainfall. Using the suggested IETD, the IETD of the Joong-Rang drainage system was determined and the area-IETD relation curve was drawn. The resulting regression curve can be used to determinate the IETD of ungauged urban drainage systems, with areas ranging between 40 and 4400 ha. Using the regression curve, the IETDs and time distribution of the design rainfall for four drainage systems in Korea were determined and rainfall-runoff simulations were performed with the Storm Water Management Model (SWMM. The results were compared with those from Huff's method which assumed a six-hour IETD. The peak flow rates obtained by the suggested method were 11%~15% greater than those obtained by Huff’s method. The suggested IETD determination method can identify independent events that are suitable for the statistical analysis of the recorded rainfall aimed at the design of urban drainage system devices.

  16. Global 30m Height Above the Nearest Drainage (United States)

    Donchyts, Gennadii; Winsemius, Hessel; Schellekens, Jaap; Erickson, Tyler; Gao, Hongkai; Savenije, Hubert; van de Giesen, Nick


    Variability of the Earth surface is the primary characteristics affecting the flow of surface and subsurface water. Digital elevation models, usually represented as height maps above some well-defined vertical datum, are used a lot to compute hydrologic parameters such as local flow directions, drainage area, drainage network pattern, and many others. Usually, it requires a significant effort to derive these parameters at a global scale. One hydrological characteristic introduced in the last decade is Height Above the Nearest Drainage (HAND): a digital elevation model normalized using nearest drainage. This parameter has been shown to be useful for many hydrological and more general purpose applications, such as landscape hazard mapping, landform classification, remote sensing and rainfall-runoff modeling. One of the essential characteristics of HAND is its ability to capture heterogeneities in local environments, difficult to measure or model otherwise. While many applications of HAND were published in the academic literature, no studies analyze its variability on a global scale, especially, using higher resolution DEMs, such as the new, one arc-second (approximately 30m) resolution version of SRTM. In this work, we will present the first global version of HAND computed using a mosaic of two DEMS: 30m SRTM and Viewfinderpanorama DEM (90m). The lower resolution DEM was used to cover latitudes above 60 degrees north and below 56 degrees south where SRTM is not available. We compute HAND using the unmodified version of the input DEMs to ensure consistency with the original elevation model. We have parallelized processing by generating a homogenized, equal-area version of HydroBASINS catchments. The resulting catchment boundaries were used to perform processing using 30m resolution DEM. To compute HAND, a new version of D8 local drainage directions as well as flow accumulation were calculated. The latter was used to estimate river head by incorporating fixed and

  17. Suceava Anthropic Torrential Basin - Prolegomena

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    Andrei-Emil BRICIU


    Full Text Available One problem discussed by urban hydrology today is the draining influence of the modern cities over the natural drainage systems. The increasing urban areas and of their imperviousness all over theworld is linked to floods shape modifications and unpredicted systemic implications.  Generally, the draining influence of a city over its environment begins when it has a surface great enough to create an anthropic-generated runoff during a rain with enoughprecipitations to provoke waters accumulation into street torrents. The size, imperviousness, precipitations, drainage system and water consumption of the Suceava city are analysed in order to estimate the discharge of the city into Suceava river at various rainfalls. The article is structured as follows:1. Argumentation on the class separation between natural and anthropic torrential basins.2. Placing Suceava city as one of the torrential anthropic basins in Romania using basic arguments.3. Extending one of the argument, the importance of the rainfalls, in more detailed discussions (rainfall characteristics mainly, but also its cumulative effect with the floods on the Suceava river and the consumption of water in the city, with two scenarios. 4. The city is analysed as being integrated into a metropolitan area which can exacerbate the influence of the main city over the surrounding natural drainage basins nearby that area.5. Conclusions, where measures are proposed in order to diminish the potential negative effects on environment and human society.This article is only an introduction to a more detailed analysis which will be complete with further field data.

  18. Materials for subsurface land drainage systems

    NARCIS (Netherlands)

    Stuyt, L.C.P.M.; Dierickx, W.; Martínez Beltrán, J.


    The purpose of this Paper is to provide this practical information to drainage engineers and contractors. The Paper is based on the current knowledge of water flow into drain pipes and envelopes, their properties and applicability. It also contains guidelines for the selection of drainage materials

  19. 24 CFR 3285.604 - Drainage system. (United States)


    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Drainage system. 3285.604 Section... DEVELOPMENT MODEL MANUFACTURED HOME INSTALLATION STANDARDS Ductwork and Plumbing and Fuel Supply Systems § 3285.604 Drainage system. (a) Crossovers. Multi-section homes with plumbing in more than one section...

  20. Correlation between theoretical anatomical patterns of lymphatic drainage and lymphoscintigraphy findings during sentinel node detection in head and neck melanomas

    Energy Technology Data Exchange (ETDEWEB)

    Vidal, Monica; Ruiz, Diana Milena [Hospital Clinic de Barcelona, Nuclear Medicine Department, Barcelona (Spain); Vidal-Sicart, Sergi; Paredes, Pilar; Pons, Francesca [Hospital Clinic de Barcelona, Nuclear Medicine Department, Barcelona (Spain); Institut d' Investigacions Biomediques Agusti Pi i Sunyer (IDIBAPS), Barcelona (Spain); Torres, Ferran [Hospital Clinic Barcelona, Statistical of Biostatistics and Data Management Core Facility, IDIBAPS, Barcelona (Spain); Universitat Autonoma de Barcelona, Biostatistics Unit, Faculty of Medicine, Barcelona (Spain)


    In the diagnosis of head and neck melanoma, lymphatic drainage is complex and highly variable. As regional lymph node metastasis is one of the most important prognostic factors, lymphoscintigraphy can help map individual drainage patterns. The aim of this study was to compare the results of lymphoscintigraphy and sentinel lymph node (SLN) detection with theoretical anatomical patterns of lymphatic drainage based on the location of the primary tumour lesion in patients with head and neck melanoma. We also determined the percentage of discrepancies between our lymphoscintigraphy and the theoretical location of nodal drainage predicted by a large lymphoscintigraphic database, in order to explain recurrence and false-negative SLN biopsies. In this retrospective study of 152 patients with head and neck melanoma, the locations of the SLNs on lymphoscintigraphy and detected intraoperatively were compared with the lymphatic drainage predicted by on-line software based on a large melanoma database. All patients showed lymphatic drainage and in all patients at least one SLN was identified by lymphoscintigraphy. Of the 152 patients, 4 had a primary lesion in areas that were not described in the Sydney Melanoma Unit database, so agreement could only be evaluated in 148 patients. Agreement between lymphoscintigraphic findings and the theoretical lymphatic drainage predicted by the software was completely concordant in 119 of the 148 patients (80.4 %, 95 % CI 73.3 - 86 %). However, this concordance was partial (some concordant nodes and others not) in 18 patients (12.2 %, 95 % CI 7.8 - 18.4 %). Discordance was complete in 11 patients (7.4 %, 95 % CI 4.2 - 12.8 %). In melanoma of the head and neck there is a high correlation between lymphatic drainage found by lymphoscintigraphy and the predicted drainage pattern and basins provided by a large reference database. Due to unpredictable drainage, preoperative lymphoscintigraphy is essential to accurately detect the SLNs in head and

  1. The Lake Albert Rift (uganda, East African Rift System): Deformation, Basin and Relief Evolution Since 17 Ma (United States)

    Brendan, Simon; François, Guillocheau; Cécile, Robin; Olivier, Dauteuil; Thierry, Nalpas; Martin, Pickford; Brigitte, Senut; Philippe, Lays; Philippe, Bourges; Martine, Bez


    .5 Ma: Rift stage 1 (subsidence rate: > 500m/Ma up to 600-800 m/Ma; sedimentation rate: 2.4 km3/Ma) - Rifting climax; - 2.5-0.4 Ma: uplift of the Ruwenzori Mountains and shifting from an alluvial system to a network of bedrock river incision - Rift Stage 2 (subsidence rate: 450 to 250 m/Ma; sedimentation rate: 1.5 km3/Ma); - 0.4-0 Ma: long wavelength downwarping of the Tanzanian Craton, initiation of the Lake Victoria trough, drainage network inversion and uplift of the present-day Ugandan escarpment (normal faulting motion of the border faults) with formation of perched valleys associated to the Lower Pleistocene (2.5-0.4 Ma) rivers network. At larger scale, comparison of the Lake Albert Rift evolution with the data available in the basins of both eastern and western branches of the East African Rift System shows that most of the sedimentary basins experienced the same geometrical evolution from large basins with limited fault controls during Late Miocene to narrow true rift in Late Pleistocene (e.g. Northern and Central Kenyan Basins), in agreement with the volcanism distribution, large (width >100 km) during the Miocene times, narrower (width x10 km) from Late Pliocene to Pleistocene times and today limited to narrow rifts.

  2. Illinois drainage water management demonstration project (United States)

    Pitts, D.J.; Cooke, R.; Terrio, P.J.; ,


    Due to naturally high water tables and flat topography, there are approximately 4 million ha (10 million ac) of farmland artificially drained with subsurface (tile) systems in Illinois. Subsurface drainage is practiced to insure trafficable field conditions for farm equipment and to reduce crop stress from excess water within the root zone. Although drainage is essential for economic crop production, there have been some significant environmental costs. Tile drainage systems tend to intercept nutrient (nitrate) rich soil-water and shunt it to surface water. Data from numerous monitoring studies have shown that a significant amount of the total nitrate load in Illinois is being delivered to surface water from tile drainage systems. In Illinois, these drainage systems are typically installed without control mechanisms and allow the soil to drain whenever the water table is above the elevation of the tile outlet. An assessment of water quality in the tile drained areas of Illinois showed that approximately 50 percent of the nitrate load was being delivered through the tile systems during the fallow period when there was no production need for drainage to occur. In 1998, a demonstration project to introduce drainage water management to producers in Illinois was initiated by NRCS4 An initial aspect of the project was to identify producers that were willing to manage their drainage system to create a raised water table during the fallow (November-March) period. Financial assistance from two federal programs was used to assist producers in retrofitting the existing drainage systems with control structures. Growers were also provided guidance on the management of the structures for both water quality and production benefits. Some of the retrofitted systems were monitored to determine the effect of the practice on water quality. This paper provides background on the water quality impacts of tile drainage in Illinois, the status of the demonstration project, preliminary

  3. VENUS - The Victoria Experimental Network Under the Sea: First Light (United States)

    Dewey, R. K.; Tunnicliffe, V.; Round, A.


    The Victoria Experimental Network Under the Sea (VENUS) is a recently installed cabled ocean observatory representing the next generation of infrastructure technology. VENUS is scheduled to consist of two major segments, one in Saanich Inlet (installed in February 2006), and a second in the Strait of Georgia (planned for October 2006). The technologies associated with both the hardware and software that will deliver data from instruments to scientists is being developed in collaboration with both the NEPTUNE Canada and MARS observatories. The presentation will provide an overview of the science projects planned for stage one of the installed instruments, the engineering design of the infrastructure, the preliminary design of the Data Management and Archive System (DMAS), lessons learned so far, and preliminary results from the first few months of data from Saanich Inlet.

  4. Myxomatosis in the Mallee region of Victoria, Australia. (United States)

    Shepherd, R C; Edmonds, J W; Nolan, I F; Gocs, A


    Sharp reductions in the wild rabbit (Oryctolagus cuniculus (L.)) population in the Mallee are associated with annual myxomatosis epizootics. The extent to which the population reductions are the direct result of the epizootics varies with time of epizootic occurrence. All grazing animals in the Mallee are under nutritional stress each summer and autumn. When the epizootic occurs during the early summer heavy losses occur in a previously healthy population. Similar losses which occur in the late summer and autumn are the result of a nutritional stress - epizootic complex. The end result in each case is a population reduction of about 80%. This reduction occurs in a population which is the most resistant to myxomatosis known in Victoria and in association with epizootics caused by field strains of myxoma virus of moderate virulence only. The earlier summer epizootics are of considerable economic importance because they sharply reduce the pressure on the limited food available for other grazing animals.

  5. Literatura y vida. Una lectura de Victoria Ocampo

    Directory of Open Access Journals (Sweden)

    María Celia Vázquez


    Full Text Available The relation of literature, writer and life, particularly, the way life is understood within this relation constitutes a key element to define the peculiar way of reading literature that Victoria Ocampo had. This can be seen in her essay on Emily Brontë; though she gives priority to biography over aesthetics, Ocampo does not adopt a biographical approach nor identifies the meaning of life with that of the writer's biography since she searches the key for interpretation in natural forces such as "character" and "fate" (instead of the positivistic interaction of social and historical environment. Thus, she identifies the vital experience of nature (the moors as the key for the writer's personality as well as her novel's, Wuthering Heights.

  6. Color variations on Victoria quadrangle: support for the geological mapping (United States)

    Zambon, F.; Galluzzi, V.; Carli, C.; Giacomini, L.; Massironi, M.; Palumbo, P.; Guzzetta, L.; Mancinelli, P.; Vivaldi, V.; Ferranti, L.; Pauselli, C.; Frigeri, A.; Zusi, M.; Pozzobon, R.; Cremonese, G.; Ferrari, S.; Capaccioni, F.


    Mercury is the closest planet to the Sun. Its extreme thermal environment makes it difficult to explore onsite. In 1974, Mariner 10, the first mission dedicated to Mercury, covered 45% of the surface during of the three Hermean flybys [1]. For about 30 years after Mariner 10, no other mission has flownto Mercury. Many unresolved issues need an answer, and in recent years the interest about Mercury has increased. MESSENGER mission contributed to understand Mercury's origin, its surface structure, and the nature of its magnetic field, exosphere, and magnetosphere [1]. The Mercury Dual Imaging System (MDIS) provided a global coverage of Mercury surface with variable spatial resolution. MDIS is equipped with a narrow angle camera (NAC), dedicated to the study of the geology and a wide angle camera (WAC) with 12 filters useful to investigate the surface composition[2]. Mercury has been divided into 15 quadrangles for mapping purposes [3]. The mapping process permits integration of different geological surface information to better understand the planet crust formation and evolution. Merging spectroscopically data is a poorly followed approach in planetary mapping, but it gives additional information about lithological composition, contributing to the construction of a more complete geological map [e.g. 4]. Recently, [5] proposed a first detailed map of all the Victoria quadrangle (H2). Victoria quadrangle is located in a longitude range between 270°E and 360°E and a latitude range of 22.5°N and 65°N,and itwas only partially mapped by Mariner 10 data[3]. Here we investigate the lithological variation by using the MDIS-WAC data to produce a set of color map products which could be asupport to the geological mapping [5]. The future ESA-JAXA mission to Mercury, BepiColombo, will soon contribute to improve the knowledge of Mercury surface composition and geology thanks to the Spectrometer and Imagers for MPO BepiColombo-Integrated Observatory SYStem (SIMBIO-SYS)[6].

  7. Deformed river basins of the Himalaya (United States)

    Walcott, R.; Sinclair, H.


    Identification of the controls on basin morphology in mountain belts is needed to understand how landscapes evolve under changing conditions. Although river basins vary enormously in area, many of their morphological relationships, such as Hack's law, are scale invariant irrespective of mountain type. This suggests that, in most mountain belts, the fundamental process(es) that control basin morphology are also scale invariant and therefore largely insensitive to variations in tectonic activity. However, river basins in the Himalaya are anomalously wide when compared with basins developed on the flanks of other semi-linear ranges. We present a detailed study of Himalayan river basin morphology to determine how the evolution of this orogen may have influenced the shape of these unusual basins. We investigate, in particular, the statistical geometric properties of basins, such as the length, width and area of basins, with respect to the scale and the location of the basin within the mountain belt. Our results show that the anomalously wide basins found over much of the Himalaya have a limited scale range and distribution. These data therefore provide an indication of the significant control that the evolution of this mountain range has had on basin morphology at the local scale. The fact that these catchments have departed from what is perceived as a stable scaling relationship implies that, while their rivers can incise at a rate broadly comparable to the rate of rock uplift, their drainage divides can not migrate fast enough to reconfigure in response to tectonic shortening. As a result, long-term crustal shortening has significantly deformed the river network within the central and western Himalaya.

  8. Linking land use changes to surface water quality variability in Lake Victoria: some insights from remote sensing (United States)

    Mugo, R. M.; Limaye, A. S.; Nyaga, J. W.; Farah, H.; Wahome, A.; Flores, A.


    The water quality of inland lakes is largely influenced by land use and land cover changes within the lake's catchment. In Africa, some of the major land use changes are driven by a number of factors, which include urbanization, intensification of agricultural practices, unsustainable farm management practices, deforestation, land fragmentation and degradation. Often, the impacts of these factors are observable on changes in the land cover, and eventually in the hydrological systems. When the natural vegetation cover is reduced or changed, the surface water flow patterns, water and nutrient retention capacities are also changed. This can lead to high nutrient inputs into lakes, leading to eutrophication, siltation and infestation of floating aquatic vegetation. To assess the relationship between land use and land cover changes in part of the Lake Victoria Basin, a series of land cover maps were derived from Landsat imagery. Changes in land cover were identified through change maps and statistics. Further, the surface water chlorophyll-a concentration and turbidity were derived from MODIS-Aqua data for Lake Victoria. Chlrophyll-a and turbidity are good proxy indicators of nutrient inputs and siltation respectively. The trends in chlorophyll-a and turbidity concentrations were analyzed and compared to the land cover changes over time. Certain land cover changes related to agriculture and urban development were clearly identifiable. While these changes might not be solely responsible for variability in chlrophyll-a and turbidity concentrations in the lake, they are potentially contributing factors to this problem. This work illustrates the importance of addressing watershed degradation while seeking to solve water quality related problems.


    Directory of Open Access Journals (Sweden)



    Full Text Available mbalance of the natural dynamic equilibrium between the processes of percolation, evaporation and surface runoff is caused because of urbanization of the previously natural areas which are transformed by humans now. More and more rainwater flows over the surface of the catchment area. Infiltration facilities are devices designed for fluent and natural infiltration of rainwater from the roofs of buildings and paved surfaces. Facilities for infiltration as one of source control measures are permeable paved areas, unpaved areas for infiltration, vegetated swales, vegetated buffer strips, bioretention, detention ponds, dry well, infiltration basins and infiltration gallery and many more. Rainwater drainage from the bridge object in Sarisske Luky in Presov district (Slovakia, using infiltration gallery is presented in the paper. Its capacity is not efficient now, so the reconstruction or other supplement solution is needed. From the wide possibilities of solutions, one of them which full fills all criterions about the rainwater infiltration in selected building object is presented and discussed.

  10. Influence of fast lymphatic drainage on metastatic spread in cutaneous malignant melanoma: a prospective feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Maza, Sofiane; Valencia, Ray; Geworski, Lilli; Sandrock, Dirk; Zander, Andreas; Munz, Dieter L. [Clinic for Nuclear Medicine, University Hospital Charite, Humboldt University of Berlin, Schumannstrasse 20-21, 10117, Berlin (Germany); Audring, Heike [Division of Dermatopathology, University Hospital Charite, Humboldt University of Berlin, Berlin (Germany); Draeger, Erik; Winter, Helmut; Sterry, Wolfram [Clinic for Dermatology, Venereology and Allergology, University Hospital Charite, Humboldt University of Berlin, Berlin (Germany)


    The concept of sentinel lymph node biopsy in cutaneous malignant melanoma is widely established. Preoperative cutaneous lymphoscintigraphic mapping is a reliable method for identifying the nodal basins at risk of metastases in melanomas. In this prospective study we investigated the correlation between the scintigraphic appearance time and the metastatic involvement of sentinel lymph nodes. In 276 malignant melanoma patients (137 women, 139 men; age 16-93 years), dynamic and static lymphoscintigraphy was performed after strict intracutaneous application of technetium-99m nanocolloid (40-150 MBq; 0.05 ml/deposit) around the tumour or biopsy scar. Analysis of dynamic scans primarily focussed on the appearance time of sentinel lymph nodes. Sentinel lymph node visualisation {<=}20 min post injection was defined as fast drainage, and visualisation >20 min as slow drainage. Fast lymphatic drainage was found in 236 patients, of whom 34 (14.4%) had sentinel lymph node metastases. Twenty-two patients showed hybrid (fast and slow) lymphatic drainage, and eight (36.4%) of them had sentinel lymph node metastases. Seven of the latter demonstrated fast lymphatic drainage, while one showed one positive sentinel lymph node with fast and another with slow drainage. The melanomas of 18 patients demonstrated exclusively slow lymphatic drainage, in all cases without sentinel lymph node metastases. This prospective study indicates that the scintigraphic appearance time of sentinel lymph nodes seems to be a clinically relevant factor for prediction of metastatic spread of cutaneous malignant melanoma. Larger numbers of patients need to be examined to truly assess the benefit of the scintigraphic appearance time compared with other predictors of sentinel lymph node tumour positivity. (orig.)

  11. Critical Comments on Brian Victoria's "Engaged Buddhism: Skeleton in the Closet?"

    Directory of Open Access Journals (Sweden)

    Koichi Miyata


    Full Text Available In "Engaged Buddhism: A Skeleton in the Closet?" (Vol. 2 Brian Daizen Victoria claims, among other things, that Tsunesaburo Makiguchi (1871-1944, founder of the Soka Kyoiku Gakkai (forebear of the Soka Gakkai and Soka Gakkai International, was an active supporter of the Japanese wars of aggression. In this response, Koichi Miyata argues that Victoria's claims rest on the highly selective use of quotes, and ignore key interpretative issues associated with Japanese imperial fascism and its underlying belief structures. Miyata discusses the significance of Makiguchi's arrest and imprisonment under a law specifically aimed at opponents of the war efforts, in his analysis of critical lapses in Victoria's article.

  12. The Tana River Basin and the opportunity for research on the land-ocean interaction in the Tana Delta


    Kitheka, Johnson U.; Ongwenyi, George S.


    The Tana River basin is one of the five main drainage basins in the Republic of Kenya. In terms of river discharge, it is one of the largest and also one of the most important drainage basins. It occupies about 23% of the total land area and contributes 32% of the total river runoff in Kenya. The basin is composed of the vast eastern plateau forelands, which sprawl between the Central Kenya Highlands to the west and the coastal strip on the east. The river flows down a gentle slope towards th...

  13. Gravity Drainage Kinetics of Papermaking Fibrous Suspensions

    Directory of Open Access Journals (Sweden)

    Przybysz Piotr


    Full Text Available The study analyses application possibilities of filtration and thickening models in evaluation of papermaking suspension drainage rate. The authors proposed their own method to estimate the drainage rate on the basis of an existing Ergun capillary model of liquid flow through a granular material. The proposed model was less sensitive to porosity changes than the Ergun model. An empirical verification proved robustness of the proposed approach. Taking into account discrepancies in the published data concerning how the drainage velocity of papermaking suspension is defined, this study examines which of the commonly applied models matches experimental results the best.

  14. Causes of Late Pleistocene water level change in Lake Victoria, Equatorial East Africa, derived from clumped isotopes of land snails and fresh water mollusks. (Invited) (United States)

    Zaarur, S.; Affek, H. P.; Tryon, C.; Peppe, D. J.; Faith, J.


    mean annual precipitation that is significantly greater than modern. However, this is inconsistent with regional climate reconstructions. This suggests that either lake level was controlled by non-climatic factors, or that local climate in the Lake Victoria basin was different than regional patterns of climate across eastern Africa. We use oxygen and clumped isotopes of modern and fossil shells (Corbicula sp., Melanoides sp. and Bellamya unicolor) from this 18 m beach outcrop on Mfangano Island to (1) compare with modern lake water δ18O values and (2) calculate paleo-water compositions. We combine these results with calculated snail body water δ18O composition (using oxygen and clumped isotopes) of land snails (Limicoloria cf. martensiana) from Rusinga and Mfangano Islands, to study hydrological changes of Lake Victoria. We use these data to evaluate the relative importance of climate change and tectonics as mechanisms for the Late Pleistocene expansion of Lake Victoria.

  15. Formation and evolution of a drainage network during the Pleistocene through a process of homoclinal shifting initiated by headward erosion. (United States)

    Castelltort, F. Xavier; Carles Balasch, J.; Cirés, Jordi; Colombo, Ferran


    A homoclinal shifting process in NE of the Ebro basin, NE Iberian Peninsula, reorganized an old flow network into a new one. This process was initiated by the reactivation of a major normal fault (Amer Fault). An anaclinal stream, flowing to the hanging wall block, incised in the fault-line scarp, accessing by headward erosion the less resistant Paleogene units. The result was the formation of a sequence of strike valleys. The first valleys are situated in a more elevated topographical position than the valleys formed later. The last and the most important valley is La Plana de Vic, which is being emptied by differential erosion in front of the resistant base layer. The study of the lateral migration of a drainage basin since its initial stages has allowed the recognition of the layout of a drainage network and its model of evolution. The new drainage network includes three different subsystems. The main subsystem consists of stream courses flowing along the strike valley. While the other two subsystems flow into the main or can flow directly to the basin sink. These are the anaclinal subsystem, which drains the scarp face of the asymmetric valley, and the cataclinal subsystem, which drains the cuesta. The process of homoclinal shifting makes the strike streams migrate laterally and dip in the less resistant unit. This migration implies the reorganization of the other two tributary subsystems. The sequence of reorganizations may be preserved on the resistant bedrock of the cuesta. This allows the reconstruction of the route of the headward erosion of the initial anaclinal stream course through remnants of ancient strike streams flowing into former basin sinks, and its cataclinal tributaries draining the cuesta. In the case study of La Plana de Vic the migration route of the basin sink can be reconstructed from its initial position, Early Pleistocene, until present day. Besides, reorganization of the cataclinal network can also be recognized. During the lateral

  16. End‐of‐life decisions in medical practice: a survey of doctors in Victoria (Australia) (United States)

    Neil, D A; Coady, C A J; Thompson, J; Kuhse, H


    Objectives To discover the current state of opinion and practice among doctors in Victoria, Australia, regarding end‐of‐life decisions and the legalisation of voluntary euthanasia. Longitudinal comparison with similar 1987 and 1993 studies. Design and participants Cross‐sectional postal survey of doctors in Victoria. Results 53% of doctors in Victoria support the legalisation of voluntary euthanasia. Of doctors who have experienced requests from patients to hasten death, 35% have administered drugs with the intention of hastening death. There is substantial disagreement among doctors concerning the definition of euthanasia. Conclusions Disagreement among doctors concerning the meaning of the term euthanasia may contribute to misunderstanding in the debate over voluntary euthanasia. Among doctors in Victoria, support for the legalisation of voluntary euthanasia appears to have weakened slightly over the past 17 years. Opinion on this issue is sharply polarised. PMID:18055904

  17. Eutrophication, Nile perch and food-web interactions in south-east Lake Victoria

    NARCIS (Netherlands)

    Cornelissen, I.J.M.


    The increasing eutrophication, the introduction of Nile perch (Lates niloticus) and the increasing fishing pressure has changed Lake Victoria tremendously the last century. Since the 1960s, eutrophication increased primary production, enabling an increase in fish production. However, eutrophication

  18. Ecological Biogeography of the Terrestrial Nematodes of Victoria Land, Antarctica

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    Byron Adams


    Full Text Available The terrestrial ecosystems of Victoria Land, Antarctica are characteristically simple in terms of biological diversity and ecological functioning. Nematodes are the most commonly encountered and abundant metazoans of Victoria Land soils, yet little is known of their diversity and distribution. Herein we present a summary of the geographic distribution, habitats and ecology of the terrestrial nematodes of Victoria Land from published and unpublished sources. All Victoria Land nematodes are endemic to Antarctica, and many are common and widely distributed at landscape scales. However, at smaller spatial scales, populations can have patchy distributions, with the presence or absence of each species strongly influenced by specific habitat requirements. As the frequency of nematode introductions to Antarctica increases, and soil habitats are altered in response to climate change, our current understanding of the environmental parameters associated with the biogeography of Antarctic nematofauna will be crucial to monitoring and possibly mitigating changes to these unique soil ecosystems.

  19. Stream habitat characteristics of fixed sites in the western Lake Michigan drainages, Wisconsin and Michigan, 1993-95 (United States)

    Fitzpatrick, F.A.; Giddings, E.M.


    Habitat characteristics of 11 fixed sites in the Western Lake Michigan Drainages were examined by the U.S. Geological Survey from 1993 through 1995 as part of the ecological assessment of the National Water-Quality Assessment Program. Evaluation of habitat consisted of more than 75 measurements at three spatial levels: drainage basin, stream segment between major tributaries (length from 1 to 14 kilometers), and stream reach (approximately 150 meters). The 11 fixed sites consisted of 8 "indicator" sites with drainage basins that differ in bedrock type, surficial deposits, and land use; and 3 "integrator" sites with drainage basins that contain a mixture of bedrock type, surficial deposits, and land use. Spatial and temporal variations in habitat characteristics are described and compared. Comparisons are limited to indicator sites except for comparisons amongbasin characteristics, which include all fixed sites. Two habitat classification schemes used in Wisconsin and Michigan were used to rank the quality of habitat in indicator streams. Reach-level data were collected at two additional reaches at three of the indicator sites to assess the representativeness of the reach for overall stream conditions.

  20. Analysis of an Organisation: A University of the Third Age (U3A), Mornington, Victoria (United States)

    Small, Michael


    The purpose of this paper is two fold: to look at Mornington U3A in organisational terms and then look at U3AM as a loosely coupled system. One outcome of the study would be to undertake further analyses of U3As in Victoria to determine the levels of bureaucracy under which each operates. Questions to be asked: are U3As in Victoria operating as…

  1. Sensitivity analysis of the GNSS derived Victoria plate motion (United States)

    Apolinário, João; Fernandes, Rui; Bos, Machiel


    Fernandes et al. (2013) estimated the angular velocity of the Victoria tectonic block from geodetic data (GNSS derived velocities) only.. GNSS observations are sparse in this region and it is therefore of the utmost importance to use the available data (5 sites) in the most optimal way. Unfortunately, the existing time-series were/are affected by missing data and offsets. In addition, some time-series were close to the considered minimal threshold value to compute one reliable velocity solution: 2.5-3.0 years. In this research, we focus on the sensitivity of the derived angular velocity to changes in the data (longer data-span for some stations) by extending the used data-span: Fernandes et al. (2013) used data until September 2011. We also investigate the effect of adding other stations to the solution, which is now possible since more stations became available in the region. In addition, we study if the conventional power-law plus white noise model is indeed the best stochastic model. In this respect, we apply different noise models using HECTOR (Bos et al. (2013), which can use different noise models and estimate offsets and seasonal signals simultaneously. The seasonal signal estimation is also other important parameter, since the time-series are rather short or have large data spans at some stations, which implies that the seasonal signals still can have some effect on the estimated trends as shown by Blewitt and Lavellee (2002) and Bos et al. (2010). We also quantify the magnitude of such differences in the estimation of the secular velocity and their effect in the derived angular velocity. Concerning the offsets, we investigate how they can, detected and undetected, influence the estimated plate motion. The time of offsets has been determined by visual inspection of the time-series. The influence of undetected offsets has been done by adding small synthetic random walk signals that are too small to be detected visually but might have an effect on the

  2. Compositional variations on Mercury: Results from the Victoria quadrangle (United States)

    Zambon, Francesca; Carli, Cristian; Galluzzi, Valentina; Capaccioni, Fabrizio; Giacomini, Lorenza; Massironi, Matteo; Palumbo, Pasquale; Cremonese, Gabriele


    Mercury was recently explored by the MESSENGER mission that orbited around the planet from March 2011 until April 2015 allowing a complete coverage of its surface. The Mercury Dual Imaging System (MDIS), mapped the Hermean surface at different spatial resolutions, due to variable altitude of the spacecraft from the surface. MDIS consists of two instruments: a Narrow Angle Camera (NAC) centered at 747nm, which acquired high-resolution images for the geological analysis, and the Wide Angle Camera (WAC), provided with 11 filters dedicated to the compositional analysis, operating in a range of wavelengths between 395 and 1040 nm. Mercury's surface has been divided into 15 quadrangles for mapping purposes. Here, we analyze the results obtained by the color composite mosaic of the quadrangle Victoria (H02) located at longitudes 270 ° - 360 ° E, and latitudes 22.5 ° N - 65 ° N. We produced a color mosaic, by using the images relative to the filters with the best spatial coverage. To obtain the 8-color mosaic of the Victoria quadrangle, we calibrated and georefenced the WAC raw images. Afterwards, we applied the Hapke photometric correction by using the parameters derived by Domingue et al. (2015). We projected and coregistered the data, and finally, we produced the mosaic. To analyze the compositional variations of the Victoria quadrangle, we consider different techniques of analysis, such as specific RGB color combinations and band ratios, which emphasize the different compositional characteristics of the surface. Furthermore, the use of clustering and classification methods allows for recognizing various terrain units, in terms of reflectance and spectral characteristics. In the H02 quadrangle, we observed a dichotomy in the RGB mosaic (R: second principal component (PC2), G: first principal component (PC1), B: 430/1000 nm; see Denevi et al. 2009) between the northern region of the quadrangle, dominated by smooth plains, and the southern part, characterized by

  3. Technical problems during percutaneous transhepatic biliary drainage

    Energy Technology Data Exchange (ETDEWEB)

    Weber, J.; Hoever, S.


    Technical problems are repeatedly encountered during percutaneous transhepatic drainage by catheter or endo-prosthesis which are caused by the position, extent and tightness of the stenosis in the biliary ducts. All means of overcoming these problems must be used, otherwise technical failure or complications become inevitable. The methods to be adopted if catheters break and endo-prostheses become displaced or occluded, and for haemorrhage, are described, as well as methods for draining multiple, proximal or intrahepatic stenoses. This is based on an experience with 74 patients on whom 130 drainage procedures have been perforemd (80 catheters, 50 endo-prostheses). All complications and mortality (five patients, 3.8%) were due to problems which could not be solved. Internal biliary drainage by means of an endoprosthesis is markedly superior to catheter drainage. (orig.).

  4. Drainage information analysis and mapping system. (United States)


    The primary objective of this research is to develop a Drainage Information Analysis and Mapping System (DIAMS), with online inspection : data submission, which will comply with the necessary requirements, mandated by both the Governmental Accounting...

  5. Pressure Jumps during Drainage in Macroporous Soils

    DEFF Research Database (Denmark)

    Soto, Diego; Paradelo Pérez, Marcos; Corral, A


    Tensiometer readings obtained at high resolution during drainage of structured soil columns revealed pressure jumps with long range correlations and burst sequences with a hierarchical structure. The statistical properties of jumps are similar to Haines jumps described in invasion percolation...... processes at pore scale, but they are much larger in amplitude and duration. Pressure jumps can result from transient redistribution of water potential in internal regions of soil and can be triggered during drainage by capillary displacements at the scale of structural pores....

  6. Extension of geographic distribution of Chrysobrycon hesperus and C. myersi (Characiformes, Characidae, Stevardiinae for several drainages flowing into the Amazon River Basin in Peru and Colombia Extensión de la distribución geográfica de Chrysobrycon hesperus y C. myersi (Characiformes, Characidae, Stevardiinae para varios drenajes fluyendo hacia la cuenca del Amazonas en Perú y Colombia

    Directory of Open Access Journals (Sweden)

    James Anyelo Vanegas-Ríos


    Full Text Available The geographic distribution of Chrysobrycon hesperus (Böhlke and C. myersi Weitzman and Menezes is extended to new localities from the upper Amazon Basin in Peru and Colombia. Chrysobrycon hesperus is recorded for the first time for the Putumayo River Basin in Colombia.Se amplía la distribución geográfica de Chrysobrycon hesperus (Böhlke y C. myersi Weitzman y Menezes para nuevas localidades de la cuenca alta del Amazonas en Perú y Colombia. Chrysobrycon hesperus se registra por primera vez para la cuenca del río Putumayo en Colombia.

  7. Great Basin cold desert shrublands and the Desert Experimental Range (United States)

    Stanley G. Kitchen; Stephanie L. Carlson


    The Great Basin is a vast, internally drained region of the Western United States, bounded by the Sierra Nevada and southern Cascade Mountain ranges to the west and the Wasatch Mountains and western rim of the Colorado Plateau to the east. Although less discrete, northern and southern boundaries are generally defined by the drainages of the Columbia and Colorado Rivers...

  8. basin in obafemi awolowo university, ile-ife, south western

    African Journals Online (AJOL)


    Aug 28, 2004 ... Printing Press, Ibadan. 106pp. Ogunkoya, O.O., 1980. Hydrology of 3" order basins in the upper Owena drainage basing of southwestern. Nigeria. Unpublished Ph.D. Thesis, Department of. Geography, University of Ife, lle-Ife, Nigeria. pp. 65-. 72. Oluwatimilehin, J.M., 1990. Scdiment dynamics in some 3".

  9. Drainage filter technologies to mitigate site-specific phosphorus losses in agricultural drainage discharge

    DEFF Research Database (Denmark)

    Kjærgaard, Charlotte; Heckrath, Goswin Johann; Canga, Eriona

    Losses of phosphorus (P) in drainage waters contribute an estimated 33% to the total agricultural P load in Denmark. Mitigating agricultural P losses is challenging, as critical P losses comprise only a very small fraction of actual soil P contents and are not directly related to fertilizer P input...... in drainage. The Danish “SUPREME-TECH” project (2010-2016) ( aims at providing the scientific basis for developing cost-effective filter technologies for P in agricultural drainage waters. The project studies different approaches of implementing filter technologies including drainage well...

  10. 46 CFR 171.155 - Drainage of an open boat. (United States)


    ... 46 Shipping 7 2010-10-01 2010-10-01 false Drainage of an open boat. 171.155 Section 171.155... PERTAINING TO VESSELS CARRYING PASSENGERS Drainage of Weather Decks § 171.155 Drainage of an open boat. The deck within the hull of an open boat must drain to the bilge. Overboard drainage of the deck is not...

  11. Percutaneous transhepatic biliary drainage in malignant extrahepatic cholestasis

    Energy Technology Data Exchange (ETDEWEB)

    Hoevels, J.


    The technique of non-surgical percutaneous transhepatic biliary drainage has been improved recently. Combined internal and external drainage of bile was enabled by manipulation of a guide wire and a drainage catheter through the stenosed or obstructed section of the extrahepatic biliary ducts. Experience have been gained concerning internal drainage of bile by percutaneous transhepatic insertion of an endoprosthesis for some years now.

  12. Harmonic dissection versus electrocautery in breast surgery in regional Victoria. (United States)

    Kiyingi, Andrew K; Macdonald, Leigh J; Shugg, Sarah A; Bollard, Ruth C


    Harmonic instruments are an alternative tool for surgical dissection. The aim of this study is to evaluate differences in clinical outcomes relating to harmonic dissection when compared with electrocautery in patients undergoing major breast surgery in a regional centre over a 3-year period. Retrospective chart analysis was conducted of 52 patients undergoing major breast surgery for carcinoma or ductal carcinoma in situ by a single surgeon in a regional centre from May 2008 to January 2011. Analysis involved the extraction of qualitative data relating to patient demographics, surgery type and specimen histopathology. Quantitative data were extracted relating to duration of surgery, duration of patient-controlled analgesia (PCA) use, length of hospital admission, drainage output and presence of infection, haematoma or seroma. Fifty-two patients underwent major breast surgery; harmonic dissection n = 32 and electrocautery n = 20. The two groups were comparable. There was no significant difference identified relating the outcome measures. The median operative duration was shorter in the harmonic dissection group, however, was not of statistical significance. No significant difference was identified between groups relating to length of inpatient stay, duration of PCA use and total volume wound drainage and total days of drainage. Incidence of seroma and infection in the groups was not significantly different. The harmonic dissection is safe and effective in major breast surgery. The study did not demonstrate any clinical advantage from the use of harmonic dissection in major breast surgery compared with electrocautery, nor was there any difference in the complication rates measured. © 2014 Royal Australasian College of Surgeons.

  13. Stratigraphic relations of australites in the Port Campbell embayment, Victoria (United States)

    Shoemaker, Eugene M.; Uhlherr, H. Ralph


    In the Port Campbell Embayment of Victoria, australites have been found in situ in channel deposits of the Hanson Plain Sand of Pliocene and Pleistocene age. The large majority of the australites, however, occur as a lag deposit at the basal contact of the Sturgess Sand of late Pleistocene and Holocene age and are spatially correlated with ferruginous sandstone clasts that are derived from the Hanson Plain Sand. Some of the tektites are imbedded in or bonded to the ferruginous sandstone clasts, but most are found as individual tektite fragments. A few percent of the tektites have nearly perfectly preserved, complete aerodynamically shaped forms. The sandstone clasts and associated tektites have been reworked from the much older underlying Hanson Plain and have been locally concentrated in the lag deposit. Some tektites also occur at higher levels in the Sturgess Sand, almost invariably in association with stone flakes, exotic stones transported by the aborigines, and, locally, with middens of mollusc shells. Circumstantial evidence indicates that the aborigines transported the tektites found in the upper part of the Sturgess, particularly at Stanhope Bay. As Port Campbell australites unequivocally occur in strata much older than the late Pleistocene and Holocene Sturgess, there is no longer any conflict between the apparent stratigraphic age of the tektites and the middle Pleistocene ages obtained by various chronometric methods.

  14. The bone microstructure of polar "hypsilophodontid" dinosaurs from Victoria, Australia. (United States)

    Woodward, Holly N; Rich, Thomas H; Vickers-Rich, Patricia


    High-latitude (i.e., "polar") Mesozoic fauna endured months of twilight and relatively low mean annual temperatures. Yet non-avian dinosaurs flourished in this taxing environment. Fossils of basal ornithopod dinosaurs ("hypsilophodontids") are common in the Early Cretaceous high-latitude sediments of Victoria, Australia, and four taxa have been described; although their ontogenetic histories are largely unexplored. In the present study, eighteen tibiae and femora were utilized in the first multi-specimen ontogenetic histological analysis of Australian polar hypsilophodontids. The sample consists of eleven individuals from the Flat Rocks locality (Late Valanginian or Barremian), and five from the Dinosaur Cove locality (Albian). In both groups, growth was most rapid during the first three years, and skeletal maturity occurred between five and seven years. There is a weak asymptotic trend in a plot of growth mark count versus femur length, with considerable individual variation. Histology suggests two genera are present within the Dinosaur Cove sample, but bone microstructure alone could not distinguish genera within the Flat Rocks sample, or across the two geologically separate (~ 26 Ma) localities. Additional histologic sampling, combined with morphological analyses, may facilitate further differentiation between ontogenetic, individual, and species variation.

  15. Diversity of soil yeasts isolated from South Victoria Land, Antarctica (United States)

    Connell, L.; Redman, R.; Craig, S.; Scorzetti, G.; Iszard, M.; Rodriguez, R.


    Unicellular fungi, commonly referred to as yeasts, were found to be components of the culturable soil fungal population in Taylor Valley, Mt. Discovery, Wright Valley, and two mountain peaks of South Victoria Land, Antarctica. Samples were taken from sites spanning a diversity of soil habitats that were not directly associated with vertebrate activity. A large proportion of yeasts isolated in this study were basidiomycetous species (89%), of which 43% may represent undescribed species, demonstrating that culturable yeasts remain incompletely described in these polar desert soils. Cryptococcus species represented the most often isolated genus (33%) followed by Leucosporidium (22%). Principle component analysis and multiple linear regression using stepwise selection was used to model the relation between abiotic variables (principle component 1 and principle component 2 scores) and yeast biodiversity (the number of species present at a given site). These analyses identified soil pH and electrical conductivity as significant predictors of yeast biodiversity. Species-specific PCR primers were designed to rapidly discriminate among the Dioszegia and Leucosporidium species collected in this study. ?? 2008 Springer Science+Business Media, LLC.

  16. Failures and complications of thoracic drainage

    Directory of Open Access Journals (Sweden)

    Đorđević Ivana


    Full Text Available Background/Aim. Thoracic drainage is a surgical procedure for introducing a drain into the pleural space to drain its contents. Using this method, the pleura is discharged and set to the physiological state which enables the reexpansion of the lungs. The aim of the study was to prove that the use of modern principles and protocols of thoracic drainage significantly reduces the occurrence of failures and complications, rendering the treatment more efficient. Methods. The study included 967 patients treated by thoracic drainage within the period from January 1, 1989 to June 1, 2000. The studied patients were divided into 2 groups: group A of 463 patients treated in the period from January 1, 1989 to December 31, 1994 in whom 386 pleural drainage (83.36% were performed, and group B of 602 patients treated form January 1, 1995 to June 1, 2000 in whom 581 pleural drainage (96.51% were performed. The patients of the group A were drained using the classical standards of thoracic drainage by the general surgeons. The patients of the group B, however, were drained using the modern standards of thoracic drainage by the thoracic surgeons, and the general surgeons trained for this kind of the surgery. Results. The study showed that better results were achieved in the treatment of the patients from the group B. The total incidence of the failures and complications of thoracic drainage decreased from 36.52% (group A to 12.73% (group B. The mean length of hospitalization of the patients without complications in the group A was 19.5 days versus 10 days in the group B. The mean length of the treatment of the patients with failures and complications of the drainage in the group A was 33.5 days versus 17.5 days in the group B. Conclusion. The shorter length of hospitalization and the lower morbidity of the studied patients were considered to be the result of the correct treatment using modern principles of thoracic drainage, a suitable surgical technique, and a

  17. Reserves in western basins: Part 1, Greater Green River basin

    Energy Technology Data Exchange (ETDEWEB)


    This study characterizes an extremely large gas resource located in low permeability, overpressured sandstone reservoirs located below 8,000 feet drill depth in the Greater Green River basin, Wyoming. Total in place resource is estimated at 1,968 Tcf. Via application of geologic, engineering and economic criteria, the portion of this resource potentially recoverable as reserves is estimated. Those volumes estimated include probable, possible and potential categories and total 33 Tcf as a mean estimate of recoverable gas for all plays considered in the basin. Five plays (formations) were included in this study and each was separately analyzed in terms of its overpressured, tight gas resource, established productive characteristics and future reserves potential based on a constant $2/Mcf wellhead gas price scenario. A scheme has been developed to break the overall resource estimate down into components that can be considered as differing technical and economic challenges that must be overcome in order to exploit such resources: in other words, to convert those resources to economically recoverable reserves. Total recoverable reserves estimates of 33 Tcf do not include the existing production from overpressured tight reservoirs in the basin. These have estimated ultimate recovery of approximately 1.6 Tcf, or a per well average recovery of 2.3 Bcf. Due to the fact that considerable pay thicknesses can be present, wells can be economic despite limited drainage areas. It is typical for significant bypassed gas to be present at inter-well locations because drainage areas are commonly less than regulatory well spacing requirements.

  18. [The biological aftereffects of preoperative and palliative percutaneous biliary drainage]. (United States)

    Arévalo, A; Hebrero, J; Arconada, J A; Fernández, M; Elexpuru, J I; Escudero, B; Lalinde, J; Pinillos, E


    Biological repercussions in 78 patients with malignant obstructive jaundice in whom percutaneous biliary drainage was performed, are reported. In 37 cases drainage was done during operation while 41 were palliative. Biochemistry, proteinogram, hematological studies, renal function and immunology were assessed 15.7 +/- 3.4 days postoperatively and 25.2 +/- 4.7 days in palliative drainage. Results show a significant improvement of all parameters, more important in preoperative drainages especially in those combining percutaneous and internal drainage techniques.

  19. Flow structures and fluid transport for the hydromedusae Sarsia tubulosa and Aequorea victoria. (United States)

    Lipinski, Doug; Mohseni, Kamran


    The flow structures produced by the hydromedusae Sarsia tubulosa and Aequorea victoria are examined using direct numerical simulation and Lagrangian coherent structures (LCS). Body motion of each hydromedusa is digitized and input to a CFD program. Sarsia tubulosa uses a jetting type of propulsion, emitting a single, strong, fast-moving vortex ring during each swimming cycle while a secondary vortex of opposite rotation remains trapped within the subumbrellar region. The ejected vortex is highly energetic and moves away from the hydromedusa very rapidly. Conversely, A. victoria, a paddling type hydromedusa, is found to draw fluid from the upper bell surface and eject this fluid in pairs of counter-rotating, slow-moving vortices near the bell margins. Unlike S. tubulosa, both vortices are ejected during the swimming cycle of A. victoria and linger in the tentacle region. In fact, we find that A. victoria and S. tubulosa swim with Strouhal numbers of 1.1 and 0.1, respectively. This means that vortices produced by A. victoria remain in the tentacle region roughly 10 times as long as those produced by S. tubulosa, which presents an excellent feeding opportunity during swimming for A. victoria. Finally, we examine the pressure on the interior bell surface of both hydromedusae and the velocity profile in the wake. We find that S. tubulosa produces very uniform pressure on the interior of the bell as well as a very uniform jet velocity across the velar opening. This type of swimming can be well approximated by a slug model, but A. victoria creates more complicated pressure and velocity profiles. We are also able to estimate the power output of S. tubulosa and find good agreement with other hydromedusan power outputs. All results are based on numerical simulations of the swimming jellyfish.

  20. Characterising groundwater dynamics in Western Victoria, Australia using Menyanthes software (United States)

    Woldeyohannes, Yohannes; Webb, John


    Water table across much of the western Victoria, Australia have been declining for at least the last 10-15 years, and this is attributed to the consistently low rainfall for these years, but over the same period of time there has been substantial change in land use, with grazing land replaced by cropping and tree plantations appearing in some areas. Hence, it is important to determine the relative effect the climate and land use factors on the water table changes. Monitoring changes in groundwater levels to climate variables and/or land use change is helpful in indicating the degree of threat faced to agricultural and public assets. The dynamics of the groundwater system in the western Victoria, mainly on the basalt plain, have been modelled to determine the climatic influence in water table fluctuations. In this study, a standardized computer package Menyanthes was used for quantifying the influence of climatic variables on the groundwater level, statistically estimating trends in groundwater levels and identify the properties that determine the dynamics of groundwater system. This method is optimized for use on hydrological problems and is based on the use of continuous time transfer function noise model, which estimates the Impulse response function of the system from the temporal correlation between time series of groundwater level and precipitation surplus. In this approach, the spatial differences in the groundwater system are determined by the system properties, while temporal variation is driven by the dynamics of the input into the system. 80 time series models are analysed and the model output parameter values characterized by their moments. The zero-order moment Mo of a distribution function is its area and M1 is related to the mean of the impulse response function. The relation is M1/Mo. It is a measure of the system's memory. It takes approximately 3 times the mean time (M1/Mo) for the effect of a shower to disappear completely from the system. Overall

  1. A mafic-ultramafic cumulate sequence derived from boninite-type melts (Niagara Icefalls, northern Victoria Land, Antarctica) (United States)

    Tribuzio, Riccardo; Tiepolo, Massimo; Fiameni, Stefania


    The layered sequence from Niagara Icefalls (northern Victoria Land, Antarctica) is related to the Cambrian-Early Ordovician Ross Orogeny. The sequence consists of dunites, harzburgites, orthopyroxenites, melagabbronorites and gabbronorites of cumulus origin. The Mg# of olivine, spinel, orthopyroxene and clinopyroxene from these rocks yields positive correlations, thus indicating formation from melts that mainly evolved through fractional crystallisation. The following fractionation sequence was identified: olivine (up to 94 mol% forsterite) + Cr-rich spinel → olivine + orthopyroxene ± spinel → orthopyroxene → orthopyroxene + anorthite-rich plagioclase ± clinopyroxene. Clinopyroxenes retain the peculiar trace element signature of boninite melts, such as extremely low concentrations of HREE and HFSE, and LILE enrichment over REE and HFSE. U-Pb isotope data on zircons separated from a gabbronorite have allowed us to constrain the age of emplacement of the Niagara Icefalls sequence at ˜514 Ma. The occurrence of inherited zircons dated at ˜538 Ma indicates that the boninitic melts experienced, at least locally, crustal contamination. The Niagara Icefalls sequence can be related to a regional scale magmatic event that affected the eastern margin of the Gondwana supercontinent in the Middle Cambrian. We propose that the formation of the sequence was associated with the development of an embryonic back-arc basin in an active continental margin.

  2. Evaluation of vehicle side airbag effectiveness in Victoria, Australia. (United States)

    D'Elia, Angelo; Newstead, Stuart; Scully, Jim


    Side airbag systems were first introduced into vehicles around 1995 to help protect occupants from injury in side impact crashes. International studies have shown that side airbags are effective in reducing the risk of death and injury, however, serious injuries can still occur even when side airbags deploy. The objective of this study was to use detailed injury information from insurance injury compensation claims data linked to Police reported crash data to determine the effectiveness of side airbags in reducing the risk of death or injury for occupants involved in side impact crashes in Victoria, Australia based on the specific body regions that side airbag systems are designed to protect. It was found that head and torso-protecting dual airbag systems designed to protect the head, neck, face, chest and abdomen are highly effective in reducing driver death or injury due to near side crashes. They were associated with a statistically significant reduction of 41.1% (25.9%, 53.2%) in the odds of death or injury across all body regions; and a 48.0% (28.0%, 62.4%) reduction in the odds of death or injury to the head, neck, face, chest and abdomen. The study did not find any evidence that torso-protecting airbags alone are effective in reducing death or injury. Analysis results indicate that head and torso-protecting side airbag systems in vehicles are a highly effective technology for reducing the risk of death or injury to vehicle occupants in near side crashes. The magnitude of the injury reduction benefits estimated indicate that fitment of this technology to all vehicles should be a high priority and will yield significant savings in overall road trauma. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Percutaneous epidural drainage through a burr hole

    Directory of Open Access Journals (Sweden)

    Priscila M Falsarella


    Full Text Available Intracranial extradural collection may cause an increase in intracranial pressure, requiring rapid emergency treatment to reduce morbidity and mortality. We described an alternative CT-guided percutaneous access for extradural collection drainage. We report a case of a patient with previous craniectomy for meningioma ressection who presented to the Emergency Department with symptoms of intracranial hypertension. Brains CT showed a extradural collection with subfalcine herniation. After multidisciplinary discussion a CT-guided percutaneous drainage through previous burr hole was performed. The patient was discharged after 36 hours of admission, without further symptoms. We describe a safe and effective alternative percutaneous access for extradural collection drainage in patients with previous burr hole.


    Directory of Open Access Journals (Sweden)



    Full Text Available Altogether 327 valleys and their 314 cross-sectional profiles were analyzed on Mars, including width, depth, length, eroded volume, drainage and spatial density, as well as the network structure.According to this systematic analysis, five possible drainage network types were identified such as (a small valleys, (b integrated small valleys, (c individual, medium-sized valleys, (d unconfined,anastomosing outflow valleys, and (e confined outflow valleys. Measuring their various morphometric parameters, these five networks differ from each other in terms of parameters of the eroded volume, drainage density and depth values. This classification is more detailed than those described in the literature previously and correlated to several numerical parameters for the first time.These different types were probably formed during different periods of the evolution of Mars, and sprung from differently localized water sources, and they could be correlated to similar fluvialnetwork types from the Earth.

  5. An Innovative Approach for Drainage Network Sizing

    Directory of Open Access Journals (Sweden)

    Luca Cozzolino


    Full Text Available In this paper, a procedure for the optimal design of rural drainage networks is presented and demonstrated. The suggested approach, exploring the potentialities offered by heuristic methods for the solution of complex optimization problems, is based on the use of a Genetic Algorithm (GA, coupled with a steady and uniform flow hydraulic module. In particular, this work has focused: on one hand, on the problems of a technical nature posed by the correct sizing of a drainage network; on the other hand, on the possibility to use a simple but nevertheless efficient GA to reach the minimal cost solution very quickly. The suitability of the approach is tested with reference to small and large scale drainage networks, already considered in the literature.

  6. Glaucoma Drainage Device Erosion Following Ptosis Surgery. (United States)

    Bae, Steven S; Campbell, Robert J


    To highlight the potential risk of glaucoma drainage device erosion following ptosis surgery. Case report. A 71-year-old man underwent uncomplicated superotemporal Ahmed glaucoma valve implantation in the left eye in 2008. Approximately 8 years later, the patient underwent bilateral ptosis repair, which successfully raised the upper eyelid position. Three months postoperatively, the patient's glaucoma drainage implant tube eroded through the corneal graft tissue and overlying conjunctiva to become exposed. A graft revision surgery was successfully performed with no further complications. Caution and conservative lid elevation may be warranted when performing ptosis repair in patients with a glaucoma drainage implant, and patients with a glaucoma implant undergoing ptosis surgery should be followed closely for signs of tube erosion.

  7. Adaption to Extreme Rainfall with Open Urban Drainage System: An Integrated Hydrological Cost-Benefit Analysis

    DEFF Research Database (Denmark)

    Zhou, Qianqian; Panduro, Toke Emil; Thorsen, Bo Jellesmark


    This paper presents a cross-disciplinary framework for assessment of climate change adaptation to increased precipitation extremes considering pluvial flood risk as well as additional environmental services provided by some of the adaptation options. The ability of adaptation alternatives to cope...... amenity effects, an integration of open drainage basins in urban recreational areas is likely the best adaptation strategy, followed by pipe enlargement and local infiltration strategies. All three were improvements compared to the fourth strategy of no measures taken........ The framework was applied to the northern part of the city of Aarhus, Denmark. We investigated four adaptation strategies that encompassed laissez-faire, larger sewer pipes, local infiltration units, and open drainage system in the urban green structure. We found that when taking into account environmental...


    Directory of Open Access Journals (Sweden)

    Walter Collischonn


    Full Text Available The development and improvement of Geographic Information Systems and geoprocessing algorithms,together with the increase in computational capacity and data availability from remote sensing, becamepossible to prepare information for hydrologic studies of large areas with relative low cost and incrediblespeed. This paper describes the use of SRTM data to derive drainage network and related products, suchas accumulated drainage areas and river lengths, with application to the Uruguay river basin. Six distinctDigital Elevation Models (DEMs were used, varying the spatial resolution and applying the stream burningpre-processing technique. The main limitations of the DEM-derived drainage network refer to the incapacityof representing river meanders that are smaller than the pixel size and the problem of artificial sinuosity thatoccurs when the width of the river is larger than pixel side.

  9. Drying out the Nile? Regional Climate Change and Water Resources in East Africa with a focus on Lake Victoria and Lake Tana (United States)

    Mottram, Ruth; Fox Maule, Cathrine; Thejll, Peter; Stendel, Martin; Drews, Martin; Davies, Sarah; Lamb, Henry


    The East African lakes Victoria and Tana are important local water resources for agriculture, fisheries and hydropower; they are also the main sources of the Nile. In this study we focus on the evaporative and evapotranspirative regimes of the hydrological basins for Lakes Tana and Victoria to determine how regional climate change under the A1B scenario is likely to affect the local and regional hydrology. We show results from a very high resolution (10km) simulation, where the state-of-the-art regional climate model (RCM) HIRHAM5 was driven by the global circulation model (GCM) ECHAM5 under the A1B scenario. Three time-slices have been investigated for present day (1980-1999), mid-century (2046-2065) and end of the 21st century (2080-2099) periods. Our analysis includes a comparison with a coarser 0.44o (~50 km) resolution run which demonstrates the importance of using high resolution (10km or higher) in RCM studies of this type to correctly simulate the seasonal and geographical characteristics of the present day east African monsoon system. The projections also indicate that climate change under the intermediate SRES A1B scenario is expected to cause more frequent failures of the East African rains with important consequences for the region and for the hydrology of the East African Lakes. This work introduces the proposed DACEA (Drivers of Aridity Change in East Africa) project which aims to investigate regional and global teleconnections that affect aridity in East Africa. Future work will combine climate palaeoproxies from Lake Tana and Lake Victoria with model experiments carried out with the EC-Earth coupled Ocean-Atmosphere General Circulation Model and downscaled to very high resolution with the RCM HIRHAM5 to determine regional and global scale influences on the African monsoon system. The HIRHAM5 simulations will be dynamically coupled to a regional hydrological model based on MIKE SHE, to evaluate the consequences and the feedback from the regional

  10. Hydrological Modelling of Ganga River basin. (United States)

    Anand, J.; Gosain, A. K.; Khosa, R.


    Application of a hydrological model, Soil and Water Assessment Tool (SWAT) to the Ganga basin having a total drainage area of around 1.08 M sq. km extending over Tibet, Nepal, India and Bangladesh has been made. The model is calibrated to determine the spatial deviations in runoff at sub-basin level, and to capture the water balance of the river basin. Manual calibration approach was used for calibrating the SWAT model by following multi-step procedure to get to the realistic present situation as close as possible. Simulations were then further made with and without proposed future projects to obtain various scenarios. The various statistical parameters used for the evaluation of the monthly runoff simulation showed that SWAT performed well in mimicking the monthly stream flow for Ganga River basin. The model under predicted the flows in the non-perennial region during non-monsoon season, due to low rainfall and regulated flows and seepage taking place from the reservoirs. The impacts of the interventions, both existing as well as proposed, on the water balance of the basin were evaluated and quantified. The derived results suggest that there is a substantial reduction in overall water resources availability in the study basin on account of the current level of development and further, future developments, as are being proposed, may require a careful study of their potential impact on currently sanctioned water use. The present study showcases that efficacy of the model for simulating the stream flow is admirable.

  11. Morfologia da flor, fruto e plântula de Victoria amazonica (Poepp. J.C. Sowerby (Nymphaeaceae Morphology of flower, fruit and seedling of Victoria amazonica (Poepp. J.C. Sowerby (Nymphaeaceae

    Directory of Open Access Journals (Sweden)

    Sônia Maciel da Rosa-Osman


    Full Text Available Victoria amazonica (Poepp. J.C. Sowerby é uma hidrófita que ocorre nas várzeas de águas brancas e igapós da Bacia Amazônica e na Bacia do rio Paraguai. A morfologia da flor, fruto e plântula/"tirodendro" é objeto do presente trabalho. O material botânico foi coletado em Parintins e Manaus, estado do Amazonas, Brasil. A análise morfológica foi feita em material fresco e fixado em FAA 50. O desenvolvimento das plântulas foi realizado no escuro em frascos com água com teor reduzido de oxigênio. As flores possuem pedicelo longo e são hemicíclicas, diclamídeas, monoclinas e com antese vespertina. Os frutos são carnosos, indeiscentes, com pseudossincarpia. As sementes apresentam arilo que atua na dispersão pela água. As plântulas se desenvolvem em condições de hipoxia e apresentam um cotilédone exposto acicular. O "tirodendro" apresenta eofilos com heterofilia. As flores apresentam caracteres morfológicos básicos da família, a definição do tipo de fruto exige estudo ontogenético e a heterofilia é um caráter típico de plântulas/"tirodendros"de Nymphaeaceae.Victoria amazonica (Poepp. J.C. Sowerby is a hydrophyte that occurs in the white water leas and igapos of the Amazonian and Paraguay Basin. The flower, fruit and seedling/"tirodendro" morphology is the object of the present work. The botanical material was collected at Parintins and Manaus, Amazonian state, Brazil. The morphological analysis was made in both fresh and fixed material. The seedling development was accomplished in flasks with water containing little oxygen and maintained in the darkness. Flowers present long pedicel and they are hemicyclic, dichlamydeous, bisexual with vespertine anthesis. Fruits are fleshy, indehiscent with pseudo-syncarpy. Seeds present aril that acts in the water dispersion. Seedlings grow in hypoxy conditions and they present an acicular and exposed cotyledon. The "tirodendro" stage presents eophylls with heterophylly. Flowers

  12. Essentials of Endorheic Basins and Lakes: A Review in the Context of Current and Future Water Resource Management and Mitigation Activities in Central Asia


    Vadim Yapiyev; Zhanay Sagintayev; Vassilis J. Inglezakis; Kanat Samarkhanov; Anne Verhoef


    Endorheic basins (i.e., land-locked drainage networks) and their lakes can be highly sensitive to variations in climate and adverse anthropogenic activities, such as overexploitation of water resources. In this review paper, we provide a brief overview of one major endorheic basin on each continent, plus a number of endorheic basins in Central Asia (CA), a region where a large proportion of the land area is within this type of basin. We summarize the effects of (changing) climate drivers and ...

  13. Groundwater quality in the San Diego Drainages Hydrogeologic Province, California (United States)

    Wright, Michael T.; Belitz, Kenneth


    More than 40 percent of California's drinking water is from groundwater. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State's groundwater quality and increases public access to groundwater-quality information. The San Diego Drainages Hydrogeologic Province (hereinafter referred to as San Diego) is one of the study units being evaluated. The San Diego study unit is approximately 3,900 square miles and consists of the Temecula Valley, Warner Valley, and 12 other alluvial basins (California Department of Water Resources, 2003). The study unit also consists of all areas outside defined groundwater basins that are within 3 kilometers of a public-supply well. The study unit was separated, based primarily on hydrogeologic settings, into four study areas: Temecula Valley, Warner Valley, Alluvial Basins, and Hard Rock (Wright and others, 2005). The sampling density for the Hard Rock study area, which consists of areas outside of groundwater basins, was much lower than for the other study areas. Consequently, aquifer proportions for the Hard Rock study area are not used to calculate the aquifer proportions shown by the pie charts. An assessment of groundwater quality for the Hard Rock study area can be found in Wright and Belitz, 2011. The temperatures in the coastal part of the study unit are mild with dry summers, moist winters, and an average annual rainfall of about 10 inches. The temperatures in the mountainous eastern part of the study unit are cooler than in the coastal part, with an annual precipitation of about 45 inches that occurs mostly in the winter. The primary aquifers consist of Quaternary-age alluvium and weathered bedrock in the Temecula Valley, Warner Valley, and Alluvial Basins study areas, whereas in the Hard Rock study area the primary aquifers consist mainly of fractured and

  14. The role of river drainages in shaping the genetic structure of capybara populations. (United States)

    Byrne, María Soledad; Quintana, Rubén Darío; Bolkovic, María Luisa; Cassini, Marcelo H; Túnez, Juan Ignacio


    The capybara, Hydrochoerus hydrochaeris, is an herbivorous rodent widely distributed throughout most of South American wetlands that lives closely associated with aquatic environments. In this work, we studied the genetic structure of the capybara throughout part of its geographic range in Argentina using a DNA fragment of the mitochondrial control region. Haplotypes obtained were compared with those available for populations from Paraguay and Venezuela. We found 22 haplotypes in 303 individuals. Hierarchical AMOVAs were performed to evaluate the role of river drainages in shaping the genetic structure of capybara populations at the regional and basin scales. In addition, two landscape genetic models, isolation by distance and isolation by resistance, were used to test whether genetic distance was associated with Euclidean distance (i.e. isolation by distance) or river corridor distance (i.e. isolation by resistance) at the basin scale. At the regional scale, the results of the AMOVA grouping populations by mayor river basins showed significant differences between them. At the basin scale, we also found significant differences between sub-basins in Paraguay, together with a significant correlation between genetic and river corridor distance. For Argentina and Venezuela, results were not significant. These results suggest that in Paraguay, the current genetic structure of capybaras is associated with the lack of dispersion corridors through permanent rivers. In contrast, limited structuring in Argentina and Venezuela is likely the result of periodic flooding facilitating dispersion.

  15. Marine research in the Latitudinal Gradient Project along Victoria Land, Antarctica

    Directory of Open Access Journals (Sweden)

    Paul Arthur Berkman


    Full Text Available This paper describes the conceptual framework of the Latitudinal Gradient Project that is being implemented by the New Zealand, Italian and United States Antarctic programmes along Victoria Land, Antarctica, from 72°S to 86°S. The purpose of this interdisciplinary research project is to assess the dynamics and coupling of marine and terrestrial ecosystems in relation to global climate variability. Preliminary data about the research cruises from the R/V “Italica” and R/V “Tangaroa” along the Victoria Land Coast in 2004 are presented. As a global climate barometer, this research along Victoria Land provides a unique framework for assessing latitudinal shifts in ‘sentinel’ environmental transition zones, where climate changes have an amplified impact on the phases of water.

  16. Multistage late Cenozoic evolution of the Amargosa River drainage, southwestern Nevada and eastern California Society of America. All rights reserved (United States)

    Menges, C.M.


    Stratigraphic and geomorphic analyses reveal that the regional drainage basin of the modern Amargosa River formed via multistage linkage of formerly isolated basins in a diachronous series of integration events between late Miocene and latest Pleistocene-Holocene time. The 275-km-long Amargosa River system drains generally southward across a large (15,540 km 2) watershed in southwestern Nevada and eastern California to its terminus in central Death Valley. This drainage basin is divided into four major subbasins along the main channel and several minor subbasins on tributaries; these subbasins contain features, including central valley lowlands surrounded by highlands that form external divides or internal paleodivides, which suggest relict individual physiographic-hydrologic basins. From north to south, the main subbasins along the main channel are: (1) an upper headwaters subbasin, which is deeply incised into mostly Tertiary sediments and volcanic rocks; (2) an unincised low-gradient section within the Amargosa Desert; (3) a mostly incised section centered on Tecopa Valley and tributary drainages; and (4) a west- to northwest-oriented mostly aggrading lower section along the axis of southern Death Valley. Adjoining subbasins are hydro-logically linked by interconnecting narrows or canyon reaches that are variably incised into formerly continuous paleodivides. The most important linkages along the main channel include: (1) the Beatty narrows, which developed across a Tertiary bedrock paleodivide between the upper and Amargosa Desert subbasins during a latest Miocene-early Pliocene to middle Pleistocene interval (ca. 4-0.5 Ma); (2) the Eagle Mountain narrows, which cut into a mostly alluvial paleodivide between the Amar-gosa Desert and Tecopa subbasins in middle to late Pleistocene (ca. 150-100 ka) time; and (3) the Amargosa Canyon, which formed in late middle Pleistocene (ca. 200140 ka) time through a breached, actively uplifting paleodivide between the Tecopa

  17. Chemodenitrification in the cryoecosystem of Lake Vida, Victoria Valley, Antarctica. (United States)

    Ostrom, N E; Gandhi, H; Trubl, G; Murray, A E


    Lake Vida, in the Victoria Valley of East Antarctica, is frozen, yet harbors liquid brine (~20% salt, >6 times seawater) intercalated in the ice below 16 m. The brine has been isolated from the surface for several thousand years. The brine conditions (permanently dark, -13.4 °C, lack of O2 , and pH of 6.2) and geochemistry are highly unusual. For example, nitrous oxide (N2 O) is present at a concentration among the highest reported for an aquatic environment. Only a minor 17 O anomaly was observed in N2 O, indicating that this gas was predominantly formed in the lake. In contrast, the 17 O anomaly in nitrate (NO3-) in Lake Vida brine indicates that approximately half or more of the NO3- present is derived from atmospheric deposition. Lake Vida brine was incubated in the presence of 15 N-enriched substrates for 40 days. We did not detect microbial nitrification, dissimilatory reduction of NO3- to ammonium (NH4+), anaerobic ammonium oxidation, or denitrification of N2 O under the conditions tested. In the presence of 15 N-enriched nitrite (NO2-), both N2 and N2 O exhibited substantial 15 N enrichments; however, isotopic enrichment declined with time, which is unexpected. Additions of 15 N-NO2- alone and in the presence of HgCl2 and ZnCl2 to aged brine at -13 °C resulted in linear increases in the δ15 N of N2 O with time. As HgCl2 and ZnCl2 are effective biocides, we interpret N2 O production in the aged brine to be the result of chemodenitrification. With this understanding, we interpret our results from the field incubations as the result of chemodenitrification stimulated by the addition of 15 N-enriched NO2- and ZnCl2 and determined rates of N2 O and N2 production of 4.11-41.18 and 0.55-1.75 nmol L-1  day-1 , respectively. If these rates are representative of natural production, the current concentration of N2 O in Lake Vida could have been reached between 6 and 465 years. Thus, chemodenitrification alone is sufficient to explain the high levels of N2 O

  18. Stroke Incidence in Victoria, Australia—Emerging Improvements

    Directory of Open Access Journals (Sweden)

    Benjamin B. Clissold


    Full Text Available BackgroundEvidence of a decline in the incidence of stroke has emerged from population-based studies. These have included retrospective and prospective cohorts. However, in Australia and other countries, government bodies and stroke foundations predict a rise in the prevalence of stroke that is anticipated to increase the burden of stroke across the entire domain of care. This increase in prevalence must be viewed as different from the decline in incidence being observed, a measure of new stroke cases. In Victoria, all public emergency department visits and public and private hospital admissions are reported to the Department of Health and Human Services and include demographic, diagnostic, and procedural/treatment information.MethodsWe obtained data from financial years 1997/1998 to 2007/2008 inclusive, for all cases with a primary stroke diagnosis (ICD-10-AM categories with associated data fields. Incident cases were established by using a 5-year clearance period.ResultsFrom 2003/2004 to 2007/2008 inclusive, there were 53,425 patients with a primary stroke or TIA diagnosis. The crude incident stroke rate for first ever stroke was 211 per 100,000 per year (95% CI 205–217 [females—205 per 100,000 per year (95% CI 196–214 and males—217 per 100,000 per year (95% CI 210–224]. The overall stroke rates were seen to significantly decline over the period [males (per 100,000 per year 227 in 2003/2004 to 202 in 2007/2008 (p = 0.0157 and females (per 100,000 per year 214 in 2003/2004 to 188 in 2007/2008 (p = 0.0482]. Ischemic stroke rates also appeared to decline; however, this change was not significant.ConclusionThese results demonstrate a significant decline in stroke incidence during the study period and may suggest evidence for effectiveness of primary and secondary prevention strategies in cerebrovascular risk factor management.

  19. Peritoneal drainage for newborn intestinal perforation: primary ...

    African Journals Online (AJOL)

    Tel: +1 915 545 6855; fax: +1 915 545 6864; e-mail: Received 10 September 2012 accepted 23 February 2013. Introduction. Peritoneal drainage (PD) was first described as a temporizing measure for the treatment of extremely ill newborns with intestinal perforation (IP) [1]. Subse- quent reports ...

  20. Drainage hydraulics of permeable friction courses (United States)

    Charbeneau, Randall J.; Barrett, Michael E.


    This paper describes solutions to the hydraulic equations that govern flow in permeable friction courses (PFC). PFC is a layer of porous asphalt approximately 50 mm thick that is placed as an overlay on top of an existing conventional concrete or asphalt road surface to help control splash and hydroplaning, reduce noise, and enhance quality of storm water runoff. The primary objective of this manuscript is to present an analytical system of equations that can be used in design and analysis of PFC systems. The primary assumptions used in this analysis are that the flow can be modeled as one-dimensional, steady state Darcy-type flow and that slopes are sufficiently small so that the Dupuit-Forchheimer assumptions apply. Solutions are derived for cases where storm water drainage is confined to the PFC bed and for conditions where the PFC drainage capacity is exceeded and ponded sheet flow occurs across the pavement surface. The mathematical solutions provide the drainage characteristics (depth and residence time) as a function of rainfall intensity, PFC hydraulic conductivity, pavement slope, and maximum drainage path length.

  1. Recovery of water from acid mine drainage

    CSIR Research Space (South Africa)

    Mulopo, J


    Full Text Available Metrohm 691 pH meter. BACKGRounD The CSIR patented Alkali Barium and Calcium (ABC) process uses the barium technology to remove sulphate from acid mine drainage (AMD) water and other industrial effluents. The sulphate removal process involves...

  2. Systemic venous drainage: can we help Newton? (United States)

    Corno, Antonio F


    In recent years substantial progress occurred in the techniques of cardiopulmonary bypass, but the factor potentially limiting the flexibility of cardiopulmonary bypass remains the drainage of the systemic venous return. In the daily clinical practice of cardiac surgery, the amount of systemic venous return on cardiopulmonary bypass is directly correlated with the amount of the pump flow. As a consequence, the pump flow is limited by the amount of venous return that the pump is receiving. On cardiopulmonary bypass the amount of venous drainage depends upon the central venous pressure, the height differential between patient and inlet of the venous line into the venous reservoir, and the resistance in the venous cannula(s) and circuit. The factors determining the venous return to be taken into consideration in cardiac surgery are the following: (a) characteristics of the individual patient; (b) type of planned surgical procedure; (c) type of venous cannula(s); (d) type of circuit for cardiopulmonary bypass; (e) strategy of cardiopulmonary bypass; (f) use of accessory mechanical systems to increased the systemic venous return. The careful pre-operative evaluation of all the elements affecting the systemic venous drainage, including the characteristics of the individual patient and the type of required surgical procedure, the choice of the best strategy of cardiopulmonary bypass, and the use of the most advanced materials and tools, can provide a systemic venous drainage substantially better than what it would be allowed by the simple "Law of universal gravitation" by Isaac Newton.

  3. Peritoneal drainage for newborn intestinal perforation: primary ...

    African Journals Online (AJOL)

    Background Peritoneal drainage (PD) was introduced 30 years ago as a temporizing treatment for extremely ill newborns with intestinal perforation (IP). Subsequent reports have shown it to be helpful as a definitive treatment, whereas others have labeled it as an unnecessary delay before laparotomy. Methods This is a ...

  4. Optimizing the closed suction surgical drainage system. (United States)

    Carruthers, Katherine H; Eisemann, Bradley S; Lamp, Susan; Kocak, Ergun


    Closed suction drains are indicated in a wide array of postoperative settings, with many distinct drainage systems available to the surgeon. The purpose of this study was to compare the suction gradients achieved using 2 different sizes of suction reservoirs and 2 different techniques for generating negative pressure. Drainage reservoirs of 100 and 400 ml were chosen to evaluate their ability to achieve suction. Suction was established in both sizes of drains by pressing the sides of the reservoir together or by pushing the bottom of the reservoir toward the top. Negative pressures were recorded with the reservoir empty, and after every 10-ml addition of saline. Averages were graphed to illustrate the applied suction over a range of drain volumes. The 100-ml drainage system reached a peak suction of -117.6 mmHg, while the 400-ml drainage system reached only a peak suction of -71.4 mmHg. Both of the maximum suction readings were achieved using the full-squeeze technique. The bottom-pushed-in technique did not result in any sustained measurable levels of suction using either of the reservoir volumes. Smaller drain reservoirs are more successful in generating a high initial suction than larger reservoirs, especially when the volume of fluid in the drain is relatively low. In all sizes of drains, compressing the sides of the reservoir is a far better technique for establishing negative pressure than pressing the bottom of the drain up toward the top.

  5. Selecting the drainage method for agricultural land

    NARCIS (Netherlands)

    Bos, M.G.


    To facilitate crop growth excess water should be drained from the rooting zone to allow root development of the crop and from the soil surface to facilitate access to the field. Basically, there are three drainage methods from which the designer can select being; surface drains, pumped tube wells

  6. Stratigraphic architecture of bedrock reference section, Victoria Crater, Meridiani Planum, Mars (United States)

    Edgar, Lauren A.; Grotzinger, John P.; Hayes, Alex G.; Rubin, David M.; Squyres, Steve W.; Bell, James F.; Herkenhoff, Ken E.


    The Mars Exploration Rover Opportunity has investigated bedrock outcrops exposed in several craters at Meridiani Planum, Mars, in an effort to better understand the role of surface processes in its geologic history. Opportunity has recently completed its observations of Victoria crater, which is 750 m in diameter and exposes cliffs up to ~15 m high. The plains surrounding Victoria crater are ~10 m higher in elevation than those surrounding the previously explored Endurance crater, indicating that the Victoria crater exposes a stratigraphically higher section than does the Endurance crater; however, Victoria strata overlap in elevation with the rocks exposed at the Erebus crater. Victoria crater has a well-developed geomorphic pattern of promontories and embayments that define the crater wall and that reveal thick bedsets (3–7m) of large-scale cross-bedding, interpreted as fossil eolian dunes. Opportunity was able to drive into the crater at Duck Bay, located on the western margin of Victoria crater. Data from the Microscopic Imager and Panoramic Camera reveal details about the structures, textures, and depositional and diagenetic events that influenced the Victoria bedrock. A lithostratigraphic subdivision of bedrock units was enabled by the presence of a light-toned band that lines much of the upper rim of the crater. In ascending order, three stratigraphic units are named Lyell, Smith, and Steno; Smith is the light-toned band. In the Reference Section exposed along the ingress path at Duck Bay, Smith is interpreted to represent a zone of diagenetic recrystallization; however, its upper contact also coincides with a primary erosional surface. Elsewhere in the crater the diagenetic band crosscuts the physical stratigraphy. Correlation with strata present at nearby promontory Cape Verde indicates that there is an erosional surface at the base of the cliff face that corresponds to the erosional contact below Steno. The erosional contact at the base of Cape Verde

  7. Archiving the Web: A Case Study from the University of Victoria

    Directory of Open Access Journals (Sweden)

    Corey Davis


    Full Text Available The University of Victoria Libraries started archiving websites in 2013, and it quickly became apparent that many scholarly websites being produced by faculty, especially in the digital humanities, were going to prove very challenging to effectively capture and play back. This article will provide an overview of web archiving and explore the considerable legal and technical challenges of implementing a web archiving initiative at a research library, using the University of Victoria's implementation of Archive-it, a web archiving service from the Internet Archive, as a case study, with a special focus on capturing complex, interactive websites that scholars are creating to disseminate their research in new ways.

  8. Widespread surface meltwater drainage in Antarctica (United States)

    Kingslake, J.; Ely, J.; Das, I.; Bell, R. E.


    Surface meltwater is thought to cause ice-shelf disintegration, which accelerates the contribution of ice sheets to sea-level rise. Antarctic surface melting is predicted to increase and trigger further ice-shelf disintegration during this century. These climate-change impacts could be modulated by an active hydrological network analogous to the one in operation in Greenland. Despite some observations of Antarctic surface and sub-surface hydrological systems, large-scale active surface drainage in Antarctica has rarely been studied. We use satellite imagery and aerial photography to reveal widespread active hydrology on the surface of the Antarctic Ice Sheet as far south as 85o and as high as 1800 m a.s.l., often near mountain peaks that protrude through the ice (nunataks) and relatively low-albedo `blue-ice areas'. Despite predominantly sub-zero regional air temperatures, as simulated by a regional climate model, Antarctic active drainage has persisted for decades, transporting water through surface streams and feeding vast melt ponds up to 80 km long. Drainage networks (the largest are over 100 km in length) form on flat ice shelves, steep outlet glaciers and ice-sheet flanks across the West and East Antarctica Ice Sheets. Motivated by the proximity of many drainage systems to low-albedo rock and blue-ice areas, we hypothesize a positive feedback between exposed-rock extent, BIA formation, melting and ice-sheet thinning. This feedback relies on drainage moving water long distances from areas near exposed rock, across the grounding line onto and across ice shelves - a process we observe, but had previously thought to be unlikely in Antarctica. This work highlights previously-overlooked processes, not captured by current regional-scale models, which may accelerate the retreat of the Antarctic Ice Sheet.

  9. Revision of the Amphilius jacksonii complex (Siluriformes: Amphiliidae), with the descriptions of five new species. (United States)

    Thomson, Alfred W; Page, Lawrence M; Hilber, Samantha A


    The Amphilius jacksonii complex is revised, and five new species are described: A. ruziziensis n. sp. from the Ruzizi River drainage and northeastern tributaries of Lake Tanganyika; A. pedunculus n. sp. from the Malagarasi River drainage, Lake Rukwa basin, and upper Great Ruaha River drainage, Rufiji basin; A. frieli n. sp. from the upper Congo basin; A. crassus n. sp. from the Rufiji and Wami basins; and A. lujani n. sp. from the Lake Kyogo drainage, northeastern tributaries of Lake Victoria, and the Lake Manyara basin.

  10. Exit and Paradise Creek Drainage Area Boundaries, Alaska, 2012 (United States)

    U.S. Geological Survey, Department of the Interior — This dataset contains drainage area boundaries for Exit Creek and Paradise Creek in Kenai Fjords National Park, Alaska. A drainage area boundary identifies the land...

  11. Projected climate change effects on subsurface drainage and the performance of controlled drainage in the Western Lake Erie Basin (United States)

    The US Midwest is expected to experience higher intensity rainfall events along with an increased chance of drought during the mid- and late-21st century under climate change. Development of strategies to mitigate the impact of these projected changes on agricultural production may be critical for e...

  12. Paleolakes of Northeastern Hellas Basin (United States)

    Glines, N.; Hargitai, H.; Gulick, V.


    We have identified and measured 34 potential paleolakes within the Navua-Hadriacus-Ausonia region of NE Hellas Basin, Mars. These lakes were fed by channels active episodically throughout Mars' history, likely sourced from both local ground water and precipitation on upslope crater rims and mountain peaks. Up to 2,500 km3 of water or ice would have filled these 34 paleolakes. Evidence for hydrothermal activity from the local volcanic zone may be preserved in deposit layers throughout the drainage systems. While we promote the region as a target of prime astrobiological investigation, we also propose an increased potential for paleolake identification throughout the highlands, following similar detailed CTX-resolution channel and deposit mapping.

  13. Integration of sewer system maps in topographically based sub-basin delineation in suburban areas (United States)

    Jankowfsky, Sonja; Branger, Flora; Braud, Isabelle; Rodriguez, Fabrice


    Due to the increase of urbanization, suburban areas experience a fast change in land use. The impact of such modifications on the watershed hydrological cycle must be quantified. To achieve this goal, distributed hydrological models offer the possibility to take into account land use change, and more particularly to consider urbanized areas and anthropogenic features such as roads or ditches and their impact on the hydrological cycle. A detailed definition of the hydrographical drainage network and a corresponding delineation of sub-basins is therefore necessary as input to distributed models. Sub-basins in natural catchments are usually delineated using standard GIS based terrain analysis. The drainage network in urbanised watersheds is often modified, due to sewer systems, ditches, retention basins, etc.. Therefore, its delineation is not only determined by topography. The simple application of terrain analysis algorithms to delineate sub-basins in suburban areas can consequently lead to erroneous sub-basin borders. This study presents an improved approach for sub-basin delineation in suburban areas. It applies to small catchments connected to a sewage plant, located outside the catchment boundary. The approach assumes that subsurface flow follows topography. The method requires a digital elevation model (DEM), maps of land use, cadastre, sewer system and the location of measurement stations and retention basins. Firstly, the topographic catchment border must be defined for the concerning flow measurement station. Standard GIS based algorithms, like the d8-flow direction algorithm (O'Callaghan and Mark, 1984) can be applied using a high resolution DEM. Secondly, the artificial catchment outlets have to be determined. Each catchment has one natural outlet - the measurement station on the river- but it can have several artificial outlets towards a sewage station. Once the outlets are determined, a first approximation of the "theoretical maximal contributing area

  14. Geometric disequilibrium of river basins produces long-lived transient landscapes (United States)

    Beeson, Helen W.; McCoy, Scott W.; Keen-Zebert, Amanda


    Although equilibrium has long been considered the attractor state for landscapes, the time required to reach equilibrium or even the possibility of reaching equilibrium is still debated. Using 10Be-based catchment-averaged denudation rates, topographic analysis, and analysis of the basin topology and geometry, including its area-channel length scaling relationship, we show that an ancient postorogenic dome on the North American Craton, the Ozark dome, is not in a state of equilibrium. The persistent state of disequilibrium on the Ozark dome is characterized by nonuniform erosion rates that vary by a factor of three, asymmetric drainage divides, and evidence for drainage rearrangement via stream capture. We find that planform geometric disequilibrium of river basins and drainage area exchange between adjoining basins can hold river networks in a disequilibrium state for potentially hundreds of million years and that, when sustained over time, erosion rate differences associated with drainage area exchange can lead to transient events such as stream capture and production of relief in the form of elevated, low-relief surfaces. Our results suggest that landscapes with slowly moving drainage divides might not reach equilibrium, and that river basin dynamics may contribute to setting the large-scale morphology of old cratonic landscapes.

  15. Hydrogeologic Framework of the Salt Basin, New Mexico and Texas (United States)

    Ritchie, A. B.; Phillips, F. M.


    The Salt Basin is a closed drainage basin located in southeastern New Mexico (Otero, Chaves, and Eddy Counties), and northwestern Texas (Hudspeth, Culberson, Jeff Davis, and Presidio Counties), which can be divided into a northern and a southern system. Since the 1950s, extensive groundwater withdrawals have been associated with agricultural irrigation in the Dell City, Texas region, just south of the New Mexico-Texas border. Currently, there are three major applications over the appropriations of groundwater in the Salt Basin. Despite these factors, relatively little is known about the recharge rates and storage capacity of the basin, and the estimates that do exist are highly variable. The Salt Basin groundwater system was declared by the New Mexico State Engineer during 2002 in an attempt to regulate and control growing interest in the groundwater resources of the basin. In order to help guide long-term management strategies, a conceptual model of groundwater flow in the Salt Basin was developed by reconstructing the tectonic forcings that have affected the basin during its formation, and identifying the depositional environments that formed and the resultant distribution of facies. The tectonic history of the Salt Basin can be divided into four main periods: a) Pennsylvanian-to-Early Permian, b) Mid-to-Late Permian, c) Late Cretaceous, and d) Tertiary-to-Quaternary. Pennsylvanian-to-Permian structural features affected deposition throughout the Permian, resulting in three distinct hydrogeologic facies: basin, shelf-margin, and shelf. Permian shelf facies rocks form the primary aquifer within the northern Salt Basin, although minor aquifers occur in Cretaceous rocks and Tertiary-to-Quaternary alluvium. Subsequent tectonic activity during the Late Cretaceous resulted in the re-activation of many of the earlier structures. Tertiary-to-Quaternary Basin-and-Range extension produced the current physiographic form of the basin.

  16. Drainage of Splenic Abscess: A Case Report | Kombo | Nigerian ...

    African Journals Online (AJOL)

    ... and was managed by tube drainage. His post operative recovery was uneventful. Conclusion: Tube drainage of the splenic abscess is encouraged if there is easy access to the abscess and there is evidence of residual splenic tissue in the critically ill patient. Key Word: Tube drainage, splenic abscess, splenectomy.

  17. An Integrated Hydrological and Water Management Study of the Entire Nile River System - Lake Victoria to Nile Delta (United States)

    Habib, Shahid; Zaitchik, Benjamin; Alo, Clement; Ozdogan, Mutlu; Anderson, Martha; Policelli, Fritz


    The Nile basin River system spans 3 million km(exp 2) distributed over ten nations. The eight upstream riparian nations, Ethiopia, Eretria, Uganda, Rwanda, Burundi, Congo, Tanzania and Kenya are the source of approximately 86% of the water inputs to the Nile, while the two downstream riparian countries Sudan and Egypt, presently rely on the river's flow for most of the their needs. Both climate and agriculture contribute to the complicated nature of Nile River management: precipitation in the headwaters regions of Ethiopia and Lake Victoria is variable on a seasonal and inter-annual basis, while demand for irrigation water in the arid downstream region is consistently high. The Nile is, perhaps, one of the most difficult trans-boundary water issue in the world, and this study would be the first initiative to combine NASA satellite observations with the hydrologic models study the overall water balance in a to comprehensive manner. The cornerstone application of NASA's Earth Science Research Results under this project are the NASA Land Data Assimilation System (LDAS) and the USDA Atmosphere-land Exchange Inverse (ALEXI) model. These two complementary research results are methodologically independent methods for using NASA observations to support water resource analysis in data poor regions. Where an LDAS uses multiple sources of satellite data to inform prognostic simulations of hydrological process, ALEXI diagnoses evapotranspiration and water stress on the basis of thermal infrared satellite imagery. Specifically, this work integrates NASA Land Data Assimilation systems into the water management decision support systems that member countries of the Nile Basin Initiative (NBI) and Regional Center for Mapping of Resources for Development (RCMRD, located in Nairobi, Kenya) use in water resource analysis, agricultural planning, and acute drought response to support sustainable development of Nile Basin water resources. The project is motivated by the recognition that

  18. Morphotectonics of the Jamini River basin, Bundelkhand Craton, Central India; using remote sensing and GIS technique (United States)

    Prakash, K.; Mohanty, T.; Pati, J. K.; Singh, S.; Chaubey, K.


    Morphological and morphotectonic analyses have been used to obtain information that influence hydrographic basins, predominantly these are modifications of tectonic elements and the quantitative description of landforms. Discrimination of morphotectonic indices of active tectonics of the Jamini river basin consists the analyses of asymmetry factor, ruggedness number, basin relief, gradient, basin elongation ratio, drainage density analysis, and drainage pattern analysis, which have been completed for each drainage basin using remote sensing and GIS techniques. The Jamini river is one of the major tributaries of the Betwa river in central India. The Jamini river basin is divided into five subwatersheds viz. Jamrar, Onri, Sainam, Shahzad and Baragl subwatershed. The quantitative approach of watershed development of the Jamini river basin, and its four sixth (SW1-SW4) and one fifth (SW5) order subwatersheds, was carried out using Survey of India toposheets (parts of 54I, 54K, 54L, 54O, and 54P), Landsat 7 ETM+, ASTER (GDEM) data, and field data. The Jamini river has low bifurcation index which is a positive marker of tectonic imprint on the hydrographic network. The analyses show that the geomorphological progression of the study area was robustly influenced by tectonics. The analysis demonstrates to extensional tectonics system with the following alignments: NE-SW, NW-SE, NNE-SSW, ENE-WSW, E-W, and N-S. Three major trends are followed by lower order streams viz. NE-SW, NW-SE, and E-W directions which advocate that these tectonic trends were active at least up to the Late Pleistocene. The assessment of morphotectonic indices may be used to evaluate the control of active faults on the hydrographic system. The analysis points out westward tilting of the drainage basins with strong asymmetry in some reaches, marked elongation ratio of subwatersheds, and lower order streams having close alignment with lineaments (active faults). The study facilitated to considerate the

  19. Hydrographic Basins Analysis Using Digital Terrain Modelling (United States)

    Mihaela, Pişleagă; -Minda Codruţa, Bădăluţă; Gabriel, Eleş; Daniela, Popescu


    The paper, emphasis the link between digital terrain modelling and studies of hydrographic basins, concerning the hydrological processes analysis. Given the evolution of computing techniques but also of the software digital terrain modelling made its presence felt increasingly, and established itself as a basic concept in many areas, due to many advantages. At present, most digital terrain modelling is derived from three alternative sources such as ground surveys, photogrammetric data capture or from digitized cartographic sources. A wide range of features may be extracted from digital terrain models, such as surface, specific points and landmarks, linear features but also areal futures like drainage basins, hills or hydrological basins. The paper highlights how the use appropriate software for the preparation of a digital terrain model, a model which is subsequently used to study hydrographic basins according to various geomorphological parameters. As a final goal, it shows the link between digital terrain modelling and hydrographic basins study that can be used to optimize the correlation between digital model terrain and hydrological processes in order to obtain results as close to the real field processes.



    V. Kiran; Dr. Bhimasen .S; E. Mastanaiah; A. Thiruppathi


    Background: Patients with COPD will have more amount of secretions. To clear the secretions by using of different bronchial hygiene techniques like postural drainage and autogenic drainage technique, manual hyperventilation technique ,active cycle breathing technique .Hence in this study to compare the short-term effects of postural drainage with clapping (PD) and autogenic drainage (AD) on level of oxygen saturation in blood, and amount of sputum recovery. Methodology: The study was done ...

  1. Timing and causes of gully erosion in the riparian zone of the semi-arid tropical Victoria River, Australia: Management implications (United States)

    McCloskey, G. L.; Wasson, R. J.; Boggs, G. S.; Douglas, M.


    Gully erosion in the seasonally wet tropics of Australia is a major source of sediment in rivers. Stabilization of gullies to reduce impacts on aquatic ecosystems and water storages is a focus for management. However, the cause of the gully erosion is poorly understood and so a critical context for soil conservation is missing. It is uncertain if they are the result of post-European cattle grazing or are they much older and related to non-human factors. The causes of riparian gully erosion along a reach of the Victoria River in the semi-arid tropics of Australia were investigated using several methods. Gully complexes were described and characterised by two major components: a Flood Drainage Channel (FDC) and upslope of this an Outer Erosion Feature (OEF) characterised by badlands set within an amphitheatre. The OEF is likely to be a major source of sediment that appears to be of recent origin. A review of historical records, combined with Optically Stimulated Luminescence (OSL) dating, showed that the FDCs were well established prior to the introduction of domestic stock. It also showed that the badlands began to develop about 90 years ago; that is, about 40 years after the arrival of domestic stock. In addition, an analysis of aerial photos coupled with an on-ground survey and analysis of fallout radionuclides revealed that erosion processes are still active within the gully complexes. While the FDCs are natural drainage channels, cattle grazing probably triggered the badland formation, with the expansion aided by increased rainfall in the past 40 years. Therefore, the OEFs are of human origin and protection from grazing of the riparian zone should slow badland erosion and reduce sediment input to the river.

  2. Coupled human and natural system dynamics as key to the sustainability of Lake Victoria's ecosystem services

    NARCIS (Netherlands)

    Downing, Andrea S.; van Nes, Egbert H.; Balirwa, John S.; Beuving, Joost; Bwathondi, P. O. J.; Chapman, Lauren J.; Cornelissen, Ilse J. M.; Cowx, Iain G.; Goudswaard, Kees P. C.; Hecky, Robert E.; Janse, Jan H.; Janssen, Annette B. G.; Kaufman, Les; Kishe-Machumu, Mary A.; Kolding, Jeppe; Ligtvoet, Willem; Mbabazi, Dismas; Medard, Modesta; Mkumbo, Oliva C.; Mlaponi, Enock; Munyaho, Antony T.; Nagelkerke, Leopold A. J.; Ogutu-Ohwayo, Richard; Ojwang, William O.; Peter, Happy K.; Schindler, Daniel E.; Seehausen, Ole; Sharpe, Diana; Silsbe, Greg M.; Sitoki, Lewis; Tumwebaze, Rhoda; Tweddle, Denis; van de Wolfshaar, Karen E.; van Dijk, Han; van Donk, Ellen; van Rijssel, Jacco C.; van Zwieten, Paul A. M.; Wanink, Jan; Witte, F.; Mooij, Wolf M.


    East Africa's Lake Victoria provides resources and services to millions of people on the lake's shores and abroad. In particular, the lake's fisheries are an important source of protein, employment, and international economic connections for the whole region. Nonetheless, stock dynamics are poorly

  3. The diversity of benthic mollusks of Lake Victoria and Lake Burigi ...

    African Journals Online (AJOL)

    Molluscan diversity, abundance and distribution in sediments of Lake Victoria and its satellite lake, Lake Burigi, were investigated. The survey was carried out ... Melanoides tuberculata and Biomphalaria chaonomphala were the only two gastropods represented and widely distributed in the two lakes. Bivalvia constituting of ...

  4. Connections '98. Proceedings of a Faculty Conference (4th, Victoria, British Columbia, Canada, May 1998). (United States)

    Gibbons, Sandra L., Ed.; Anderson, John O., Ed.

    This proceedings contains 13 papers from the 1998 annual Faculty of Education conference at the University of Victoria, British Columbia (Canada). The papers are: (1) "Struggling with Re-Presentation, Voice, and Self in Narrative Research" (Marla Arvay); (2) "Women's Soccer in Canada: A Slow Road to Equity" (Meredith Bogle,…

  5. Nile perch fish processing waste along Lake Victoria in East Africa ...

    African Journals Online (AJOL)

    Worldwide, fish industry wastes are an important contaminant having an impact on the environment. The recovery of value added products from these residues constitutes an important waste reduction strategy for the industry. In East Africa, Nile perch fish processing into chilled fish fillet for export along Lake Victoria ...

  6. Water hyacinth hotspots in the Ugandan waters of Lake Victoria in ...

    African Journals Online (AJOL)

    Water hyacinth invaded Lake Victoria in the 1980s and, by 1998, had attained peak coverage of approximately 2 000 ha in the Ugandan waters of the lake. Control interventions, especially via biological means, significantly reduced the weed's coverage to non-nuisance levels (<10 ha) by 1999. Although resurgence was ...

  7. Perception of Aquaculture Education to Support Further Growth of Aquaculture Industry in Victoria, Australia (United States)

    Awal, Sadiqul; Christie, Andrew; Watson, Matthew; Hannadige, Asanka G. T.


    Purpose: The central aim of this study was to determine the perception of aquaculture educational provisions in the state of Victoria, and whether they are sufficient to ultimately support further growth of the industry. Design/methodology/approach: Questionnaires were formulated and distributed to participants in a variety of ways, including via…

  8. Lake Victoria wetlands and the ecology of the Nile tilapia, Oreochromis niloticus Linne

    NARCIS (Netherlands)

    Balirwa, J.S.


    An ecological study of wetlands was undertaken in northern Lake Victoria (East Africa) between 1993 and 1996 with a major aim of characterising shallow vegetation-dominated interface habitats, and evaluating their importance for fish, in particular, for the stocked and socio-economically

  9. People Management Practices in the Public Health Sector: Developments from Victoria, Australia (United States)

    Stanton, Pauline; Bartram, Timothy; Harbridge, Raymond


    This study investigates the impact on human resource management (HRM) practices in the public health sector in Victoria, Australia of two different government policy environments. First, it explores the Liberal Coalition Government's decentralisation of public health sector management, from 1992-1999 and second, the Labor Government's…

  10. From Aspiration to Destination: Understanding the Decisions of University Applicants in Regional Victoria (United States)

    Harvey, Andrew; Burnheim, Catherine; Joschko, Lucie; Luckman, Michael


    This paper examines the choices and destinations of prospective university students from three regional areas in Victoria. The study is based on information collected for tertiary applicants in the Gippsland, Bendigo and Mildura areas, all of which host a local university campus. Using application and enrollment data, we examine the choices that…

  11. What Do the Public Search for on the Catalogue of the State Library of Victoria? (United States)

    Waller, Vivienne


    This study examines what the public search for in the catalogue of the State Library of Victoria (SLV). As well as indicating the type of content being accessed, this gives an indication of what catalogue users expect of the State Library collection. A content analysis was undertaken of a random, stratified sample of 4,000 search queries typed in…

  12. Do invasive bullfrogs in Victoria, British Columbia, Canada, show evidence of parasite release? (United States)

    Dare, O K; Forbes, M R


    Few studies have examined vertebrate models of invasive species to explore parasite release as a proposed mechanism through which host species might become invasive. In this study, we examined evidence for parasite release in invasive American bullfrogs (Rana catesbeiana/Lithobates catesbeianus) from five sites in Victoria, British Columbia, Canada. We examined helminth species richness, as well as the prevalence, intensity and abundance of lung and kidney fluke infections. These flukes are expected to impose costs on host survival, growth and reproductive output. We compared measures of these parasite taxa with bullfrogs from Ontario and New Brunswick where they are endemic. Helminth species richness in bullfrogs from the Victoria sites was lower than in Ontario bullfrogs, but comparable to reported indices for other endemic populations. The prevalence of lung flukes (Haematoloechus spp.) in bullfrogs from Victoria was twice as high as was observed in the Ontario bullfrogs, and higher than has been reported from other endemic locations. In four of the five study sites in Victoria, numbers of Echinostoma spp. kidney cysts were lower than observed in endemic populations; however, the fifth site had uncharacteristically high numbers of cysts. In this study, there did not appear to be clear evidence to support parasite release using either parasite species numbers, or infection by specific parasite taxa. Instead, the invasive bullfrogs demonstrated high parasite species richness and high levels of infection for parasites known to be harmful to their hosts.

  13. Parasite-mediated sexual selection and species divergence in Lake Victoria cichlid fish

    NARCIS (Netherlands)

    Maan, Martine E.; Van Rooijen, Anne M. C.; Van Alphen, Jacques J. M.; Seehausen, Ole

    We investigate the role of parasite-mediated sexual selection in the divergence of two species of Lake Victoria cichlids. Pundamilia pundamilia and Pundamilia nyererei represent a common pattern of male nuptial colour divergence between haplochromine sister species: metallic grey-blue in P.

  14. Lake Victoria wetlands and the ecology of the Nile Tilapia, Oreochromis Niloticus Linné

    NARCIS (Netherlands)

    Balirwa, J.S.


    The importance of LalVictoria wetlands for the Nile tilap'a was studied. Five wetland types were defined: papyrus, reed, bulrush, hippo grass, water hyacinth. Hydrology, vegetation and distance towards open water explained the variation in abiotic and biotic factors. Over 30 fish species were

  15. Distribution of Nile perch Lates niloticus in southern Lake Victoria is ...

    African Journals Online (AJOL)

    Although Nile perch Lates niloticus is assumed to be sensitive to low oxygen concentrations, it was found in deep water in Lake Victoria, where oxygen depletion is common during the rainy season. Since factors determining Nile perch distribution are not well understood its spatial distribution in the Mwanza Gulf of Lake ...

  16. Monitoring exposure to heavy metals among children in Lake Victoria, Kenya: Environmental and fish matrix

    NARCIS (Netherlands)

    Okoth, E.O.; Admiraal, W.; Osano, O.; Ngure, V.; Kraak, M.H.S.; Omutange, E.S.


    This study used hair and nails to biomonitor heavy metals (Pb, Cd, Cr and Cu) from geological source and exposure through regular fish consumption among children in Lake Victoria, Kenya. Concentration of Pb and Cu in water reflected anthropogenic pathways, while Cd and Cr reflected accumulation from

  17. Metal concentrations in sediment and fish of Lake Victoria near and ...

    African Journals Online (AJOL)

    Concentrations of metals in sediment and fish as well as organic matter contents of sediment from Lake Victoria were investigated. The objective of the study was to compare levels of metals in sediment and fish from areas of the lake that are within and outside catchments with gold mining activities. The results showed that ...

  18. Dublin Basin


    Somerville, I.D.; C. N. Waters


    The Carboniferous rocks of the Dublin Basin extend from the east coast of north Co. Dublin westwards to the River Shannon at Athlone and northwards to the Lower Palaeozoic rocks of the Longford-Down Massif (see Strogen et al. 1996, fig. 5; Sevastopulo & Wyse Jackson 2001, fig. 10.12; Fig. 21.1). They occur in counties Longford, Westmeath, Meath, north Co. Dublin, north Co. Offaly, north Co. Kildare and south Co. Dublin. Most of the rocks in the region belong to the Mississippia...

  19. Testing the Marine Hypothesis for The Opportunity Landing Site at Victoria Crater (United States)

    Parker, T. J.


    Hypothesis Summary: 1. Meridiani Planum is a marine sulfate platform deposit, analogous to terrestrial carbonate platforms but with sulfate mineralogy, laid down during one or multiple marine transgressions over the landing site region. 2. Outcrop laminations, ripples, and larger, dune-scale bedforms are subaqueous in origin, produced by tidal currents. Aqueous deposits may be interbedded with crossbedded aeolian deposits of same composition derived from subjacent water-lain deposits during lowstands. At the scale of observations made by Opportunity, the marine hypothesis differs from the consensus, sabkha model, in two relatively minor ways (but with important differences in the inferred paleoenvironments). 3. Blueberry and cobble "lag" on top of outcrop is a lag, but indicates erosion of perhaps many meters, even tens of meters or more of outcrop material from the region by water. Wind erosion has been very limited over geologic time (perhaps less than a meter locally). 4. Remarkably-flat, horizontal geomorphic surface of outcrop was produced by shallow standing water locally, controlling both deposition and erosion of the sulfate outcrop material to within a few meters of sea level. 5. Craters in the landing site exhibit a continuum of degradation states, with Endurance and Victoria typifying the best preserved craters visited (or to be visited) by Opportunity, and Erebus and Terra Nova representing the most degraded craters visited that are larger than 100 meters across. Terra Nova is similar to numerous kilometer-scale "rock ring" craters in the Meridiani Planum landing site. 6. "Serrated" rim at Victoria is similar to, but fresher in expression, rim morphology at Erebus Crater, and may indicate water pouring over crater rim during tidal or storm surges in water level across the region. Predictions to be tested at Victoria Crater: 1. The crater's ejecta and raised rim have been destroyed by tidal currents in shallow standing water. There is no Endurance

  20. Range of drainage effect of surface mines

    Energy Technology Data Exchange (ETDEWEB)

    Sozanski, J.


    This paper discusses methods of calculating the range of effects of water drainage from surface coal mines and other surface mines. It is suggested that methods based on test pumping (water drainage) are time consuming, and the results can be distorted by atmospheric factors such as rain fall or dry period. So-called empirical formulae produce results which are often incorrect. The size of a cone shaped depression calculated on the basis of empirical formulae can be ten times smaller than the size of the real depression. It is suggested that using a formula based on the Dupuit formula is superior to other methods of depression calculation. According to the derived formulae the radius of the depresion cone is a function of parameters of the water bearing horizons, size of surface mine working and of water depression. The proposed formula also takes into account the influence of atmospheric factors (water influx caused by precipitation, etc.). (1 ref.) (In Polish)

  1. Percutaneous transhepatic biliary drainage - an analysis on 72 cases of internal drainage

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jae Hyung; Choi, Byung Ihn; Park, Chan Sup; Sung, Kyu Bo; Lee, Byung Hee; Han, Man Chung [Seoul National University College of Medicine, Seoul (Korea, Republic of)


    A total of 72 cases of internal biliary drainage procedure has been done percutaneously at Department of Radiology, Seoul National University Hospital for recent 4 and half years since August 1981. Five different types of internal drainage including endoprosthesis were applied to various conditions with different obstruction levels. The different method of procedure in each type of internal drainage was described and the results were analysed. 1. Among the clinical diagnosis in 72 cases, carcinoma of bile duct was in 37 cases as the most frequent one. The next was pancreas head carcinoma in 16 cases, followed by metastatic carcinoma and other diseases. 2. Type I internal drainage, classical internal and external type with distal end in duodenum, was applied in 43 cases as the most common one. Type II, modification of type I with distal end in CBD, was applied in 17 cases. Tyep III, endoprosthesis distal end into duodenum, was applied in 7 cases. Type IV, endoprosthesis just across the obstruction on bile duct, was applied in 2 cases, Type V, combined type of any internal drainage with external drainage, was applied in 3 cases. 3. According to various obstruction level, preferred type could be selected. For proximal obstruction type II and IV were preferred and for distal obstruction type III was chosen. However, type I could be applied in any situation. 4. Early complication occurred in 9 cases (12.5%). Clinical improvement with decrease in bilirubin level was observed in 17 of 21 cases in which follow-up data was available over 2 months. 5. Through the experience with those 72 cases it is recommended that appropriate type of internal biliary drainage should be selected according to prognosis, obstruction level and clinical findings of each patient.

  2. Hydrology of the Johnson Creek Basin, Oregon (United States)

    Lee, Karl K.; Snyder, Daniel T.


    and winter precipitation totals were used to anticipate flooding of Holgate Lake. Several factors affect annual mean flow of Johnson Creek. More precipitation falls in the southeastern area of the basin because of the topographic setting. Runoff from much of the northern and western areas of the basin does not flow into Johnson Creek due to permeable deposits, interception by combined sewer systems, and by groundwater flow away from Johnson Creek. Inflow from Crystal Springs Creek accounts for one-half of the increase in streamflow of Johnson Creek between the Sycamore and Milwaukie sites. Low flows of Johnson Creek vary as a result of fluctuations in groundwater discharge to the creek, although past water uses may have decreased flows. The groundwater contributions to streamflow upstream of river mile (RM) 5.5 are small compared to contributions downstream of this point. Comparison of flows to a nearby basin indicates that diversions of surface water may have resulted in a 50 percent decrease in low flows from about 1955 to 1977. Runoff from the drainage basin area upstream of the Johnson Creek at Sycamore site contributes more to peak streamflow and peak volume than the drainage basin area between the Sycamore and Milwaukie sites. The average increase in annual peak streamflow and annual peak volume between the two sites was 11 and 24 percent, respectively. Decreased contribution in the lower area of the drainage basin is a result of infiltration, interception by drywell and combined sewer systems, and temporary overbank storage. Trends in flow typically associated with increasing urban development were absent in Johnson Creek. Annual, low, and high flows showed no trend from 1941 to 2006. Much of the infrastructure that may affect runoff from agricultural, residential, and urban development was in place prior to collection of hydrologic data in the basin. Management of stormwater in the urban areas by routing runoff from impervious surfaces to dry

  3. Percutaneous transhepatic biliary drainage using endoprosthesis

    Energy Technology Data Exchange (ETDEWEB)

    Golder, W.; Rupp, N.


    Even in the presence of intrahepatic metastases or previous failure of biliary enteric anastomosis, patients suffering from malignant obstructive jaundice can bve given relief by biliary endoprosthesis. Mean survival time is four months. Other than with a catheter drain, spetic cholangitis is rarely observed after the insertion of an endoprosthesis. The intervention's risk will hardly be augmented by drainage of both lobes as often necessary.

  4. Life Cycle Cost for Drainage Structures (United States)


    T. J. 1984. "Corrosion Resistance of Aluminum Drainage Products: The First 25 Years," Symposium on Durability of Culverts and Storm Drains , Transportation...Practice No. 50, Washington, DC. 1984. "Symposium on Durability of Culverts and Storm Drains ," Transportation Research Record 1001, Washington, DC...Durability of Culverts and Storm Drains , Transpor’tation Research Record 1001, National Research Council, Washington, DC. pp 88-94. Brown, R. 1964

  5. The importance of lymphatic drainage in physiotherapy


    VINKLEROVÁ, Miroslava


    The theoretical part summarizes all the theoretical knowledge on the topic. I am presenting a brief history of the discovery of the lymphatic vessels and the lymphatic drainage, the lymphatic system anatomy and its functions in the human body. Next, I have defined the concept of lymphoedema and divided it by its origin to primary and secondary lymphedema. The work includes the diagnosis of lymphedema , both conservative and surgical treatment options, indications and contraindications of lymp...

  6. Factors influencing pleural drainage in parapneumonic effusions. (United States)

    Porcel, J M; Valencia, H; Bielsa, S


    The identification of parapneumonic effusions (PPE) requiring pleural drainage is challenging. We aimed to determine the diagnostic accuracy of radiological and pleural fluid findings in discriminating between PPE that need drainage (complicated PPE (CPPE)) and those that could be resolved with antibiotics only (uncomplicated PPE (UPPE)). A retrospective review of 641 consecutive PPE, of which 393 were categorized as CPPE and 248 as UPPE. Demographics, radiological (size and laterality on a chest radiograph) and pleural fluid parameters (pus, bacterial cultures, biochemistries) were compared among groups. Logistic regression was performed to determine variables useful for predicting chest drainage, and receiver-operating characteristic curves assisted in the selection of the best cutoff values. According to the likelihood ratios (LR), findings increasing the probability of chest tube usage the most were: effusions occupying ≥1/2 of the hemithorax (LR 13.5), pleural fluid pH ≤7.15 (LR 6.2), pleural fluid glucose ≤40mg/dL (LR 5.6), pus (LR 4.8), positive pleural fluid cultures (LR 3.6), and pleural fluid lactate dehydrogenase >2000U/L (LR 3.4). In the logistic regression analysis only the first two were selected as significant predictors of CPPE. In non-purulent effusions, the effusion's size and pleural fluid pH retained their discriminatory properties, in addition to a pleural fluid C-reactive protein (CRP) level >100mg/L. Large radiological effusions and a pleural fluid pH ≤7.15 were the best predictors for chest drainage in patients with PPE. In the subgroup of patients with non-purulent effusions, pleural fluid CRP also contributed to CPPE identification. Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Medicina Interna (SEMI). All rights reserved.

  7. Streaming potential during drainage and imbibition (United States)

    Zhang, Jiazuo; Vinogradov, Jan; Leinov, Eli; Jackson, M. D.


    The rock pore space in many subsurface settings is saturated with water and one or more immiscible fluid phases. Examples include nonaqueous phase liquids (NAPLs) in contaminated aquifers, supercritical CO2 during sequestration in deep saline aquifers, the vadose zone, and hydrocarbon reservoirs. Self-potential (SP) and seismoelectric (SE) methods have been proposed to monitor multiphase flow in such settings. However, to properly interpret and model these data requires an understanding of the saturation dependence of the streaming potential. This paper presents a methodology to determine the saturation dependence of the streaming potential coupling coefficient (C) and streaming current charge density (Qs) in unsteady state drainage and imbibition experiments and applies the method to published experimental data. Unsteady state experiments do not yield representative values of C and Qs (or other transport properties such as relative permeability and electrical conductivity) at partial saturation (Sw) because Sw within the sample is not uniform. An interpretation method is required to determine the saturation dependence of C and Qs within a representative elementary volume with uniform saturation. The proposed method makes no assumptions about the pore space geometry. Application of the method to published experimental data from two natural sandstone samples shows that C exhibits hysteresis between drainage and imbibition, can exhibit significant nonmonotonic variations with saturation, is nonzero at the irreducible water saturation, and can exceed the value observed at Sw = 1. Moreover, Qs increases with decreasing Sw but is not given by 1/Sw as is often assumed. The variation in Qs with Sw is very similar for a given sample and a given drainage or imbibition process, and the difference between samples is less than the difference between drainage and imbibition. The results presented here can be used to help interpret SP and SE measurements obtained in partially

  8. Revisiting a classification scheme for U.S.-Mexico alluvial basin-fill aquifers. (United States)

    Hibbs, Barry J; Darling, Bruce K


    Intermontane basins in the Trans-Pecos region of westernmost Texas and northern Chihuahua, Mexico, are target areas for disposal of interstate municipal sludge and have been identified as possible disposal sites for low-level radioactive waste. Understanding ground water movement within and between these basins is needed to assess potential contaminant fate and movement. Four associated basin aquifers are evaluated and classified; the Red Light Draw Aquifer, the Northwest Eagle Flat Aquifer, the Southeast Eagle Flat Aquifer, and the El Cuervo Aquifer. Encompassed on all but one side by mountains and local divides, the Red Light Draw Aquifer has the Rio Grande as an outlet for both surface drainage and ground water discharge. The river juxtaposed against its southern edge, the basin is classified as a topographically open, through-flowing basin. The Northwest Eagle Flat Aquifer is classified as a topographically closed and drained basin because surface drainage is to the interior of the basin and ground water discharge occurs by interbasin ground water flow. Mountains and ground water divides encompass this basin aquifer on all sides; yet, depth to ground water in the interior of the basin is commonly >500 feet. Negligible ground water discharge within the basin indicates that ground water discharges from the basin by vertical flow and underflow to a surrounding basin or basins. The most likely mode of discharge is by vertical, cross-formational flow to underlying Permian rocks that are more porous and permeable and subsequent flow along regional flowpaths beneath local ground water divides. The Southeast Eagle Flat Aquifer is classified as a topographically open and drained basin because surface drainage and ground water discharge are to the adjacent Wildhorse Flat area. Opposite the Eagle Flat and Red Light Draw aquifers is the El Cuervo Aquifer of northern Chihuahua, Mexico. The El Cuervo Aquifer has interior drainage to Laguna El Cuervo, which is a phreatic

  9. Peat accumulation in drained thermokarst lake basins in continuous, ice-rich permafrost, northern Seward Peninsula, Alaska (United States)

    Jones, Miriam C.; Grosse, Guido; Jones, Benjamin M.; Anthony, Katey Walter


    Thermokarst lakes and peat-accumulating drained lake basins cover a substantial portion of Arctic lowland landscapes, yet the role of thermokarst lake drainage and ensuing peat formation in landscape-scale carbon (C) budgets remains understudied. Here we use measurements of terrestrial peat thickness, bulk density, organic matter content, and basal radiocarbon age from permafrost cores, soil pits, and exposures in vegetated, drained lake basins to characterize regional lake drainage chronology, C accumulation rates, and the role of thermokarst-lake cycling in carbon dynamics throughout the Holocene on the northern Seward Peninsula, Alaska. Most detectable lake drainage events occurred within the last 4,000 years with the highest drainage frequency during the medieval climate anomaly. Peat accumulation rates were highest in young (50–500 years) drained lake basins (35.2 g C m−2 yr−1) and decreased exponentially with time since drainage to 9 g C m−2 yr−1 in the oldest basins. Spatial analyses of terrestrial peat depth, basal peat radiocarbon ages, basin geomorphology, and satellite-derived land surface properties (Normalized Difference Vegetation Index (NDVI); Minimum Noise Fraction (MNF)) from Landsat satellite data revealed significant relationships between peat thickness and mean basin NDVI or MNF. By upscaling observed relationships, we infer that drained thermokarst lake basins, covering 391 km2 (76%) of the 515 km2 study region, store 6.4–6.6 Tg organic C in drained lake basin terrestrial peat. Peat accumulation in drained lake basins likely serves to offset greenhouse gas release from thermokarst-impacted landscapes and should be incorporated in landscape-scale C budgets.

  10. Drainage and Stratification Kinetics of Foam Films (United States)

    Zhang, Yiran; Sharma, Vivek


    Baking bread, brewing cappuccino, pouring beer, washing dishes, shaving, shampooing, whipping eggs and blowing bubbles all involve creation of aqueous foam films. Foam lifetime, drainage kinetics and stability are strongly influenced by surfactant type (ionic vs non-ionic), and added proteins, particles or polymers modify typical responses. The rate at which fluid drains out from a foam film, i.e. drainage kinetics, is determined in the last stages primarily by molecular interactions and capillarity. Interestingly, for certain low molecular weight surfactants, colloids and polyelectrolyte-surfactant mixtures, a layered ordering of molecules, micelles or particles inside the foam films leads to a stepwise thinning phenomena called stratification. Though stratification is observed in many confined systems including foam films containing particles or polyelectrolytes, films containing globular proteins seem not to show this behavior. Using a Scheludko-type cell, we experimentally study the drainage and stratification kinetics of horizontal foam films formed by protein-surfactant mixtures, and carefully determine how the presence of proteins influences the hydrodynamics and thermodynamics of foam films.

  11. Intelligent real-time operation of a pumping station for an urban drainage system (United States)

    Hsu, Nien-Sheng; Huang, Chien-Lin; Wei, Chih-Chiang


    SummaryIn this study, we apply artificial intelligence techniques to the development of two real-time pumping station operation models, namely, a historical and an optimized adaptive network-based fuzzy inference system (ANFIS-His and ANFIS-Opt, respectively). The functions of these two models are the determination of the real-time operation criteria of various pumping machines for controlling flood in an urban drainage system during periods when the drainage gate is closed. The ANFIS-His is constructed from an adaptive network-based fuzzy inference system (ANFIS) using historical operation records. The ANFIS-Opt is constructed from an ANFIS using the best operation series, which are optimized by a tabu search of historical flood events. We use the Chung-Kong drainage basin, New Taipei City, Taiwan, as the study area. The operational comparison variables are the highest water level (WL) and the absolute difference between the final WL and target WL of a pumping front-pool. The results show that the ANFIS-Opt is better than the ANFIS-His and historical operation models, based on the operation simulations of two flood events using the two operation models.

  12. A triangular intermuscular space sentinel node in melanoma: association with axillary lymphatic drainage. (United States)

    Hennessy, Sara A; Dengel, Lynn T; Hranjec, Tjasa; Slingluff, Craig L


    Large centers have described triangular intermuscular space (TIS) sentinel nodes (SNs) for some melanomas of the back. However, their management remains controversial and poorly characterized, especially as related to the ipsilateral axillary node basin. The aim of this study was to summarize our experience with TIS SN, which may contribute to defining their appropriate surgical management. We performed a retrospective review on surgical patients from January 1993 to April 2009. Among 293 patients with upper back melanoma, data were collected on those with TIS SN. Fourteen patients (5%) with melanoma of the upper back had a TIS SN, 6 of whom (43%) were incorrectly identified at lymphoscintigraphy as axillary, and 11 of whom (79%) had a concurrent axillary SN. Micrometastatic disease was identified in TIS SN in two patients (14%) and in an axillary SN in one (9%). We found direct lymphatic drainage independently to the TIS and to the axilla, as well as a more typical pattern of drainage first to the TIS node and then to axillary nodes. We defined three patterns of lymphatic drainage to TIS and axillary nodes. The TIS and axilla are anatomically linked; patients with SN in both locations should undergo biopsies of both for optimal nodal staging. We recommend directed evaluation for TIS SN in patients with upper back melanomas and recommend clearing the TIS at the time of TIS SN biopsy. Melanoma can metastasize to TIS SN, and we discuss considerations for management of the axilla in patients with positive TIS nodes.


    Directory of Open Access Journals (Sweden)

    L. Zhang


    Full Text Available In GIS and in terrain analysis, drainage systems are important components. Due to local topography and subsurface geology, a drainage system achieves a particular drainage pattern based on the form and texture of its network of stream channels and tributaries. Drainage pattern recognition helps to provide a qualitative description of the terrain for analysis and classification and is useful for terrain modelling and visualization and applications in environment. Much research has been done on the description of drainage patterns in geography and hydrology. However automatic drainage pattern recognition in river networks is not well developed. This paper introduces a method based on geometric quantitative indicators to recognize drainage patterns in a river network automatically. Experiment results are presented and discussed.

  14. Chromium Distribution and Spatial Variations in the Finer Sediment Grain Size Fraction and Unfractioned Surficial Sediments on Nyanza Gulf, of Lake Victoria (East Africa

    Directory of Open Access Journals (Sweden)

    Job Mwamburi


    Full Text Available Surficial sediments collected from the Nyanza Gulf of Lake Victoria (East Africa were used to determine spatial concentrations of Cr and determine differences in contents of the unfractioned (whole sediment and the finer grain size sediments, establishing any changes in Cr enrichment and potential ecological risks using sediment quality guidelines. A single pollution index was also used to evaluate level of Cr contamination. The spatial mean Cr contents in the <63 µm (silt-clay fraction were found to be significantly lower than those in the unfractioned sediments, but with a strong linear positive correlation. The study results show decreasing spatial amounts of Cr in surficial sediments of the Nyanza Gulf, when compared to a study done 20 years earlier. However, the 95% confidence limits of the overall mean Cr in unfractioned sediments exceed the threshold effect concentration (TEC, indicating the potential for Cr remobilization from sediments. In general the sediment enrichment is evidence of possible dominance of lithogenous sources of Cr in the surface lake sediments, with potential anthropogenic sources from the drainage system and nearshore urban areas. The sediments are unpolluted with respect to geoaccumulation index, and sediment enrichment factors suggest a minor to moderate enrichment of Cr in surficial sediments of three sites around the Nyanza Gulf zones and around the river mouth in the main lake.

  15. Landscape response to base-level fall in extensional settings: Amargosa River, Basin and Range, USA (United States)

    Smith, J.; Brocklehurst, S. H.; Gawthorpe, R. L.; Finch, E.


    Studies examining transient landscapes within rift basins generally focus on settings where changes in boundary conditions are driven by active tectonics. However, the effect of drainage network re-organisation on landscape development and sediment routing has received significantly less attention. Within active rift settings it is common for drainage networks to become fragmented as uplift rates overcome the erosive potential of streams, while subsidence generates under-filled basins. On a regional-scale this results in poorly integrated drainage systems consisting of numerous internally drained basins. Integration can occur through the filling of sub-basins, lake over-spill, or drainage capture. This may dramatically affect base-level, catchment size, sediment flux and fluvial geomorphology, providing a natural experiment in fluvial response to changing boundary conditions, as well as representing a fundamental control on the ultimate preservation of sediments. We combine field and remote mapping with the available dating to investigate an example of late Pleistocene drainage integration in the southern Basin and Range, where drainage integration has resulted in a base-level fall and rejuvenation of the upstream landscape triggering further drainage rearrangement. The Amargosa River was previously part of an internally-drained basin, feeding the former Lake Tecopa. Drainage capture at 150-200 ka caused the Amargosa River to flow into Death Valley, carving the Amargosa Canyon through the Sperry Hills. The canyon itself has experienced aggradation as well as incision, with both terraces and fans representing levels above the current river. Upstream of the Amargosa Canyon, incision is reflected by minor knickpoints, and gullying along tributaries. For what is now westwards-flowing Willow Wash, the net incision of Amargosa Canyon has resulted in spectacular headward erosion, dissecting fan surfaces which previously graded northwest to Lake Tecopa. The Willow Wash

  16. Closed suction drainage versus closed simple drainage in the management of modified radical mastectomy wounds. (United States)

    Ezeome, E R; Adebamowo, C A


    To compare the outcomes of modified radical mastectomy wounds managed by closed wound drainage with suction and without suction. A prospective randomised trial was conducted at the University College Hospital in Ibadan, and the University of Nigeria Teaching Hospital in Enugu. Fifty women who required modified radical mastectomy for breast cancer were randomised to have closed wound drainage with suction (26 patients) and closed wound drainage without suction (24 patients). There was no significant difference in the intraoperative and postoperative variables. Suction drainage drained less volume of fluid and stayed for a shorter time in the wound, but the differences were not significant. There was no difference in the length of hospital stay, time to stitch removal, and number of dressing changes. More haematomas and wound infections occurred in the simple drain group while more seromas occurred in the suction drain group, but these were not significant. The suction drain was more difficult to manage and the cost was 15 times higher than the simple drainage system. Closed simple drains are not inferior to suction drains in mastectomy wounds and, considering the cost saving and simplicity of postoperative care, they are preferable to suction drains.

  17. Endoscopic ultrasound-guided biliary drainage as an alternative to percutaneous drainage and surgical bypass. (United States)

    Prachayakul, Varayu; Aswakul, Pitulak


    Endoscopic retrograde cholangiopancreatography had been a treatment modality of choice for both benign and malignant biliary tract obstruction for more than half century, with a very high clinical success rate and low complications. But in certain circumstances, such as advanced and locally advanced pancreatobiliary malignancies (pancreatic cancer, cholangiocarcinoma, ampullary tumor) and tight benign strictures, endoscopic retrograde cholangiopancreatography (ERCP) fails. Up to this point, the only alternative interventions for these conditions were percutaneous transhepatic biliary drainage or surgery. Endoscopic ultrasound guided interventions was introduced for a couple decades with the better visualization and achievement of the pancreatobiliary tract. And it's still in the process of ongoing development. The inventions of new techniques and accessories lead to more feasibility of high-ended procedures. Endoscopic ultrasound guided biliary drainage was a novel treatment modality for the patient who failed ERCP with the less invasive technique comparing to surgical bypass. The technical and clinical success was high with acceptable complications. Regarded the ability to drain the biliary tract internally without an exploratory laparotomy, this treatment modality became a very interesting procedures for many endosonographers, worldwide, in a short period. We have reviewed the literature and suggest that endoscopic ultrasound-guided biliary drainage is also an option, and one with a high probability of success, for biliary drainage in the patients who failed conventional endoscopic drainage.

  18. Is ultrasonography-guided drainage a safe and effective alternative to incision and drainage for deep neck space abscesses? (United States)

    Dabirmoghaddam, P; Mohseni, A; Navvabi, Z; Sharifi, A; Bastaninezhad, S; Safaei, A


    Deep neck space abscesses are common head and neck surgery emergencies. Traditionally, surgical incision and drainage has been the main treatment for deep neck abscesses. Recently, it has been suggested that ultrasound-guided drainage of neck abscesses can be an effective and less invasive alternative to incision and drainage. Patients with deep neck space abscesses referred to the emergency department of Amiralam Hospital were assessed and enrolled to the study if they met the inclusion criteria. Patients were randomly assigned to incision and drainage or ultrasound-guided drainage groups using sealed envelopes. Sixty patients were evaluated, with 30 patients in each group. There was a significant difference (p deep neck abscesses.

  19. Comparison of sand-layer geometry on flat floors of 10 modern depositional basins

    Energy Technology Data Exchange (ETDEWEB)

    Pilkey, O.H. (Duke Univ., Durham, NC); Locker, S.D.; Cleary, W.J.


    A comparative study of 10 deep turbidite basins indicates that sand-layer thickness, frequency, and continuity can be related to their basin geometries, tectonics, and source areas. This study is based on piston-core data from the flat floors of four oceanic-crust abyssal plains (Sohm, Hatteras, Blake-Bahama, and Silver), two Bahama-Plateau reentrant basins (Columbus basin and Tongue of the Ocean), three subduction zone-island arc basins (Hispaniola-Caicos, Navidad, and St. Croix basins), and one continental-borderland basin (Santa Monica basin). With increasing tectonic activity, sand layers on flat basin floors tend to be thinner and more frequent. Except in elongated narrow basins such as Navidad, source-area size is directly related to proximal sand-layer thickness. Continuity of individual sand layers is a function of drainage-basin size and depositional-basin shape. For example, on the Hatteras Abyssal Plan long-distance continuity (up to 500 km) of individual sand layers is achieved because most of the turbidites are large and are introduced only at the north upstream end. In the small horseshoe-shaped Columbus basin, sand-layer continuity is limited because flows are small and are introduced from three sides. In most basins, sands thin and the percentage of sand layers in the sediment column decreases away from source areas. However, in basins that are small relative to the typical turbidity-current size (e.g., Hispaniola-Caicos basin), the differences between basin-edge and basin-center sand layers are slight. 10 figures, 3 tables.

  20. Impacts of population growth and economic development on water quality of a lake: case study of Lake Victoria Kenya water. (United States)

    Juma, Dauglas Wafula; Wang, Hongtao; Li, Fengting


    Anthropogenic-induced water quality pollution is a major environmental problem in freshwater ecosystems today. As a result of this, eutrophication of lakes occurs. Population and economic development are key drivers of water resource pollution. To evaluate how growth in the riparian population and in the gross domestic product (GDP) with unplanned development affects the water quality of the lake, this paper evaluates Lake Victoria Kenyan waters basin. Waters quality data between 1990 and 2012 were analyzed along with reviews of published literature, papers, and reports. The nitrate-nitrogen (NO3-N), soluble phosphorus (PO4-P), chlorophyll a, and Secchi transparencies were evaluated as they are key water quality indicators. The NO3-N increased from 10 μg l(-1) in 1990 to 98 μg 1(-1) in 2008, while PO4-P increased from 4 μg l(-1) in 1990 to 57 μg l(-1) in 2008. The population and economic growth of Kenya are increasing with both having minimums in 1990 of 24.143 million people and 12.18 billion US dollars, to maximums in 2010 of 39.742 million people and 32.163 billion US dollars, respectively. A Secchi transparency is reducing with time, indicating an increasing pollution. This was confirmed by an increase in aquatic vegetation using an analysis of moderate resolution imaging spectroradiometer (MODIS) images of 2000 and 2012 of Kenyan waters. This study found that increasing population and GDP increases pollution discharge thus polluting lakes. One of major factors causing lake water pollution is the unplanned or poor waste management policy and service.

  1. Elevated temperature and acclimation time affect metabolic performance in the heavily exploited Nile perch of Lake Victoria. (United States)

    Nyboer, Elizabeth A; Chapman, Lauren J


    Increasing water temperatures owing to anthropogenic climate change are predicted to negatively impact the aerobic metabolic performance of aquatic ectotherms. Specifically, it has been hypothesized that thermal increases result in reductions in aerobic scope (AS), which lead to decreases in energy available for essential fitness and performance functions. Consequences of warming are anticipated to be especially severe for warm-adapted tropical species as they are thought to have narrow thermal windows and limited plasticity for coping with elevated temperatures. In this study we test how predicted warming may affect the aerobic performance of Nile perch (Lates niloticus), a commercially harvested fish species in the Lake Victoria basin of East Africa. We measured critical thermal maxima (CTmax) and key metabolic variables such as AS and excess post-exercise oxygen consumption (EPOC) across a range of temperatures, and compared responses between acute (3-day) exposures and 3-week acclimations. CTmax increased with acclimation temperature; however, 3-week-acclimated fish had higher overall CTmax than acutely exposed individuals. Nile perch also showed the capacity to increase or maintain high AS even at temperatures well beyond their current range; however, acclimated Nile perch had lower AS compared with acutely exposed fish. These changes were accompanied by lower EPOC, suggesting that drops in AS may reflect improved energy utilization after acclimation, a finding that is supported by improvements in growth at high temperatures over the acclimation period. Overall, the results challenge predictions that tropical species have limited thermal plasticity, and that high temperatures will be detrimental because of limitations in AS. © 2017. Published by The Company of Biologists Ltd.

  2. Interbasin underflow between closed Altiplano basins in Chile. (United States)

    Montgomery, Errol L; Rosko, Michael J; Castro, Santiago O; Keller, Barry R; Bevacqua, Paolo S


    Interbasin ground water movement of 200 to 240 L/sec occurs as underflow beneath a mountainous surface water divide separating the topographically higher Salar de Michincha from the topographically lower Salar de Coposa internally drained basins in the Altiplano of northern Chile. Salt-encrusted flats (salars) and saline lakes occur on the lowest parts of the basin floors and comprise the principal evaporative discharge areas for the basins. Because a surface water divide separates the basins, surface water drainage boundaries do not coincide with ground water drainage boundaries. In the region, interbasin ground water movement is usually not recognized, but occurs for selected basins, and at places is an important component of ground water budgets. With increasing development of water for mining industry and potential exportation of ground water from the Altiplano for use at coastal cities, demonstration and quantification of interbasin movement is important for assessment of sustainable ground water development in a region of extreme aridity. Recognition and quantification of interbasin ground water underflow will assist in management of ground water resources in the arid Chilean Altiplano environment.

  3. Swatara Creek basin of southeastern Pennsylvania--An evaluation of its hydrologic system (United States)

    Stuart, Wilbur Tennant; Schneider, William J.; Crooks, James W.


    Local concentrations of population in the Swatara Creek basin of Pennsylvania find it necessary to store, transport, and treat water because local supplies are either deficient or have been contaminated by disposal of wastes in upstream areas. Water in the basin is available for the deficient areas and for dilution of the coal-mine drainage in the northern parts and the sewage wastes in the southern parts.

  4. Coupled tectonic/surface processes modeling of the Neogene Mesopotamian basin evolution (United States)

    Fillon, Charlotte; Garcia-Castellanos, Daniel; Vergés, Jaume


    Understanding how wide and long-lived drainage systems respond to changes in plate configuration is key to decipher between climate and tectonic forcing on the sedimentary record. The Mesopotamian large foreland basin results from flexure of the Arabian plate controlled by tectonic load of the Zagros Mountains to the East. In contrast, the current drainage pattern seems to be ruled by the uplift of the Anatolian region to the North, forcing the two main river systems (Tigris and Euphrates) to drain the basin longitudinally. In addition to that, the Mesopotamian area developed where the Neogene closure of the gateway between Mediterranean sea and Indian ocean occurred consequently to the convergence of the Arabian and Eurasian plates, but modes and timing of basin development remain poorly constrained. Moreover, the connection between the Mesopotamian basin and the Indian Ocean via the Persian Gulf still remains to be understood. The purpose of this study is to understand and investigate the processes involved in the Mesopotamian basin evolution, with an emphasis on the evolution of drainage conditions, from the closure of the basin as a result of the propagation of the collision, to the opening of the drainage through the Hormuz Strait and contribution of the uplift of the Oman Mountains. To that purpose, we perform integrated modeling of surface processes (erosion/transport/sedimentation), lithospheric flexure and kinematic fault deformation. The numerical model is particularly designed to study the 3D foreland basin evolution and to dentify large-scale relationships between tectonic movements and sediment transport. This model allows us to investigate the basin history at the scale of the Arabian plate and over a long period of time, i.e. since the collision (35-20 Ma ) to present day.

  5. Water resources of the English River, Old Mans Creek, and Clear Creek basins in Iowa (United States)

    Schwob, H.H.


    The surface and ground water resources of a 991 square mile area comprising the drainage basins of English River, Old Mans Creek and Clear Creek are presented. These basins lie to the west and southwest of Iowa City, Iowa, and all three streams are tributary to the Iowa River. The area is comprised of rolling uplands with relatively broad valleys and is devoted mainly to agriculture and livestock farming.

  6. Comparison between autologous blood transfusion drainage and closed-suction drainage/no drainage in total knee arthroplasty: a meta-analysis. (United States)

    Hong, Kun-Hao; Pan, Jian-Ke; Yang, Wei-Yi; Luo, Ming-Hui; Xu, Shu-Chai; Liu, Jun


    Autologous blood transfusion (ABT) drainage system is a new unwashed salvaged blood retransfusion system for total knee replacement (TKA). However, whether to use ABT drainage, closed-suction (CS) drainage or no drainage in TKA surgery remains controversial. This is the first meta-analysis to assess the clinical efficiency, safety and potential advantages regarding the use of ABT drains compared with closed-suction/no drainage. PubMed, Embase, and the Cochrane Library were comprehensively searched in March 2015. Fifteen randomized controlled trials (RCTs) were identified and pooled for statistical analysis. The primary outcome evaluated was homologous blood transfusion rate. The secondary outcomes were post-operative haemoglobin on days 3-5, length of hospital stay and wound infections after TKA surgery. The pooled data included 1,721 patients and showed that patients in the ABT drainage group might benefit from lower blood transfusion rates (16.59 % and 37.47 %, OR: 0.28 [0.14, 0.55]; 13.05 % and 16.91 %, OR: 0.73 [0.47,1.13], respectively). Autologous blood transfusion drainage and closed-suction drainage/no drainage have similar clinical efficacy and safety with regard to post-operative haemoglobin on days 3-5, length of hospital stay and wound infections. Autologous blood transfusion drainage offers a safe and efficient alternative to CS/no drainage with a lower blood transfusion rate. Future large-volume high-quality RCTs with extensive follow-up will affirm and update this system review.

  7. Mercury pollution in the Upper Beni River, Amazonian basin : Bolivia


    Maurice Bourgoin, Laurence; Quiroga, I.; GUYOT,Jean-Loup; Malm, O


    Mercury contamination caused by the amalgamation of gold in small-scale gold mining is an environmental problem of increasing concern, particularly in tropical regions like the Amazon, where a new boom of such gold mining started in the 1970s. In Brazil, research into these problems has been carried out for many years, but there is no available data for Bolivia. The present paper surveys mercury contamination of a Bolivian river system in the Amazon drainage basin, measured in water, fish, an...

  8. Drainage network structure and hydrologic behavior of three lake-rich watersheds on the Arctic Coastal Plain, Alaska (United States)

    Arp, C.D.; Whitman, M.S.; Jones, Benjamin M.; Kemnitz, R.; Grosse, G.; Urban, F.E.


    Watersheds draining the Arctic Coastal Plain (ACP) of Alaska are dominated by permafrost and snowmelt runoff that create abundant surface storage in the form of lakes, wetlands, and beaded streams. These surface water elements compose complex drainage networks that affect aquatic ecosystem connectivity and hydrologic behavior. The 4676 km2 Fish Creek drainage basin is composed of three watersheds that represent a gradient of the ACP landscape with varying extents of eolian, lacustrine, and fluvial landforms. In each watershed, we analyzed 2.5-m-resolution aerial photography, a 5-m digital elevation model, and river gauging and climate records to better understand ACP watershed structure and processes. We show that connected lakes accounted for 19 to 26% of drainage density among watersheds and most all channels initiate from lake basins in the form of beaded streams. Of the > 2500 lakes in these watersheds, 33% have perennial streamflow connectivity, and these represent 66% of total lake area extent. Deeper lakes with over-wintering habitat were more abundant in the watershed with eolian sand deposits, while the watershed with marine silt deposits contained a greater extent of beaded streams and shallow thermokarst lakes that provide essential summer feeding habitat. Comparison of flow regimes among watersheds showed that higher lake extent and lower drained lake-basin extent corresponded with lower snowmelt and higher baseflow runoff. Variation in baseflow runoff among watersheds was most pronounced during drought conditions in 2007 with corresponding reduction in snowmelt peak flows the following year. Comparison with other Arctic watersheds indicates that lake area extent corresponds to slower recession of both snowmelt and baseflow runoff. These analyses help refine our understanding of how Arctic watersheds are structured and function hydrologically, emphasizing the important role of lake basins and suggesting how future lake change may impact hydrologic

  9. Soil surface lowering due to soil erosion in villages near Lake Victoria, Uganda (United States)

    de Meyer, A.; Deckers, J.; Poesen, J.; Isabirye, M.


    In the effort to pinpoint the sources of sediment pollution in Lake Victoria, the contribution of sedi-ment from compounds, landing sites, main roads and footpaths is determined in the catchment of Na-bera Bay and Kafunda Bay at the northern shore of Lake Victoria in southern Uganda. The amount of soil loss in compounds and landing sites is determined by the reconstruction of the original and current soil surface according to botanical and man-made datable objects. The soil erosion rate is then deter-mined by dividing the eroded soil volume (corrected for compaction) by the age of the oldest datable object. In the study area, the average soil erosion rate in compounds amounts to 107 Mg ha-1 year-1 (per unit compound) and in landing sites to 207 Mg ha-1 year-1 (per unit landing site). Although com-pounds and landing sites occupy a small area of the study area (1.1 %), they are a major source of sediment to Lake Victoria (63 %). The soil loss on footpaths and main roads is calculated by multip-lying the total length of footpaths and main roads with the average width and depth (measured towards a reference surface). After the correction for compaction is carried out, the soil erosion rate on foot-paths amounts to 34 Mg ha-1 year-1 and on main roads to 35 Mg ha-1 year-1. Also footpaths and main roads occupy a small area of the study area (1.1 %), but contribute disproportionately to the total soil loss in the catchment (22 %). In this research, the information about the village/compound given by the villager/owner is indispensable. In accordance to an adaptation of the model of McHugh et al. (2002), 32 % of the sediment that is generated in the catchment, is deposited in Lake Victoria (i.e. 2 209 Mg year-1 or 0.7 Mg ha-1 year-1). The main buffer in the study area is papyrus at the shore of Lake Victoria. Also sugarcane can be a major buffer. However, the sugarcane-area is intersected by com-pounds, landing sites, footpaths and main roads that generate large amounts of

  10. Species-specific relationships between water transparency and male coloration within and between two closely related Lake Victoria cichlid species

    NARCIS (Netherlands)

    Castillo Cajas, Ruth F; Selz, Oliver M; Ripmeester, Erwin A P; Seehausen, Ole; Maan, Martine E


    Environmental variation in signalling conditions affects animal communication traits, with possible consequences for sexual selection and reproductive isolation. Using spectrophotometry, we studied how male coloration within and between populations of two closely related Lake Victoria cichlid

  11. Water Quality in the Acadian-Pontchartrain Drainages; Louisiana and Mississippi, 1999-2001 (United States)

    Demcheck, Dennis K.; Tollett, Roland W.; Mize, Scott V.; Skrobialowski, Stanley C.; Fendick, Robert B.; Swarzenski, Christopher M.; Porter, Stephen


    This report contains the major findings of a 1999?2001 assessment of water quality in the Acadian-Pontchartrain Drainages Study Unit. It is one of a series of reports by the National Water-Quality Assessment (NAWQA) Program that present major findings in 51 major river basins and aquifer systems across the Nation. In these reports, water quality is discussed in terms of local, State, and regional issues. Conditions in a particular basin or aquifer system are compared to conditions found elsewhere and to selected national benchmarks, such as those for drinking-water quality and the protection of aquatic organisms. This report is intended for individuals working with water-resource issues in Federal, State, or local agencies, universities, public interest groups, or in the private sector. The information will be useful in addressing a number of current issues, such as the effects of agricultural and urban land use on water quality, human health, drinking water, source-water protection, hypoxia and excessive growth of algae and plants, pesticide registration, and monitoring and sampling strategies. This report also is for individuals who wish to know more about the quality of streams and ground water in areas near where they live, and how that water quality compares to other areas across the Nation. The water-quality conditions in the Acadian-Pontchartrain Drainages Study Unit summarized in this report are discussed in detail in other reports that can be accessed from ( Detailed technical information, data and analyses, collection and analytical methodology, models, graphs, and maps that support the findings presented in this report in addition to other reports in this series from other basins can be accessed from the national NAWQA Web site (

  12. Information technology and decision support tools for stakeholder-driven river basin salinity management

    Energy Technology Data Exchange (ETDEWEB)

    Quinn, N.W.T; Cozad, D.B.; Lee, G.


    Innovative strategies for effective basin-scale salinity management have been developed in the Hunter River Basin of Australia and more recently in the San Joaquin River Basin of California. In both instances web-based stakeholder information dissemination has been a key to achieving a high level of stakeholder involvement and the formulation of effective decision support salinity management tools. A common element to implementation of salinity management strategies in both river basins has been the concept of river assimilative capacity for controlling export salt loading and the potential for trading of the right to discharge salt load to the river - the Hunter River in Australia and the San Joaquin River in California. Both rivers provide basin drainage and the means of exporting salt to the ocean. The paper compares and contrasts the use of monitoring, modeling and information dissemination in the two basins to achieve environmental compliance and sustain irrigated agriculture in an equitable and socially and politically acceptable manner.

  13. Non-stationary behavior of roof drainage systems

    Directory of Open Access Journals (Sweden)

    Koláček Martin


    Full Text Available This paper reports the non-stationary behavior of a roof drainage during experimental measurement in the climate simulator. Many buildings use a fully or partially flat roof where it is necessary to use the roof drainage. Thermal behavior of roof drainage is very important from the point of view of heat transfer and potential condensation. The placement of a roof drain slightly deteriorates thermal transmittance of the roof. This experiment evaluates roof drains in the specific climate simulator where thermal conditions were dynamically controlled in the specific temperature range. The measurement was performed for two types of roof drains. The first drainage is a simple single-shell and the second is double-shell drainage. The results show the effect on the thermal transmittance of the roof section and also the minimal effect of condensation on the non-insulation part of the drainage. Both roof drains showed minimal deterioration of thermal transmittance of the roof construction.

  14. Arterial Pulsations cannot Drive Intramural Periarterial Drainage: Significance for Aβ Drainage. (United States)

    Diem, Alexandra K; MacGregor Sharp, Matthew; Gatherer, Maureen; Bressloff, Neil W; Carare, Roxana O; Richardson, Giles


    Alzheimer's Disease (AD) is the most common form of dementia and to date there is no cure or efficient prophylaxis. The cognitive decline correlates with the accumulation of amyloid-β (Aβ) in the walls of capillaries and arteries. Our group has demonstrated that interstitial fluid and Aβ are eliminated from the brain along the basement membranes of capillaries and arteries, the intramural periarterial drainage (IPAD) pathway. With advancing age and arteriosclerosis, the stiffness of arterial walls, this pathway fails in its function and Aβ accumulates in the walls of arteries. In this study we tested the hypothesis that arterial pulsations drive IPAD and that a valve mechanism ensures the net drainage in a direction opposite to that of the blood flow. This hypothesis was tested using a mathematical model of the drainage mechanism. We demonstrate firstly that arterial pulsations are not strong enough to produce drainage velocities comparable to experimental observations. Secondly, we demonstrate that a valve mechanism such as directional permeability of the IPAD pathway is necessary to achieve a net reverse flow. The mathematical simulation results are confirmed by assessing the pattern of IPAD in mice using pulse modulators, showing no significant alteration of IPAD. Our results indicate that forces other than the cardiac pulsations are responsible for efficient IPAD.

  15. Hydrogeology of sedimentary basins (United States)

    Kreitler, Charles W.


    Hydrogeologic environments in sedimentary basins are as variable as are the different types of basins. Important hydrologic characteristics can be used to distinguish the different types of basin: (1) the topographic setting as determined by the geologic and structural history of the basin; (2) permeability distribution within the basin; and (3) potential energy distributions and flow mechanisms. These parameters control residence times of waters, rates and directions of saline groundwater flow and the origin and chemical composition of the saline waters. The Gulf Coast and Palo Duro Basins, Texas, exemplify two end member types of sedimentary basins. The Gulf Coast Basin is a relatively young, Tertiary-age basin which is presently compacting; fluid movement is from the overpressured, undercompacted sediments up the structural dip or up fault zones into the hydrostatic section, natural fluid pressures are either hydrostatic or overpressured. The Palo Duro is an older, Paleozoic-age basin that has been tectonically uplifted. Fluid flow is gravity driven from topographically high recharge areas to discharge in topographically low areas. Fluid pressures are subhydrostatic. Fluids discharge more easily than they are recharged. Not all flow is derived by a simple recharge discharge model. Brines may flow from other basins into the Palo Duro Basin and waters may discharge from the Palo Duro Basin into other basins. Areal differences in the chemical composition of the basin brines may be the result of different origins.

  16. Towards understanding hydroclimatic change in Victoria, Australia – preliminary insights into the "Big Dry"

    Directory of Open Access Journals (Sweden)

    A. S. Kiem


    Full Text Available Since the mid-1990s the majority of Victoria, Australia, has experienced severe drought conditions (i.e. the "Big Dry" characterized by streamflow that is the lowest in approximately 80 years of record. While decreases in annual and seasonal rainfall totals have also been observed, this alone does not seem to explain the observed reduction in flow. In this study, we investigate the large-scale climate drivers for Victoria and demonstrate how these modulate the regional scale synoptic patterns, which in turn alter the way seasonal rainfall totals are compiled and the amount of runoff per unit rainfall that is produced. The hydrological implications are significant and illustrate the need for robust hydrological modelling, that takes into account insights into physical mechanisms that drive regional hydroclimatology, in order to properly understand and quantify the impacts of climate change (natural and/or anthropogenic on water resources.

  17. Use of regionalisation approach to develop fire frequency curves for Victoria, Australia (United States)

    Khastagir, Anirban; Jayasuriya, Niranjali; Bhuyian, Muhammed A.


    It is important to perform fire frequency analysis to obtain fire frequency curves (FFC) based on fire intensity at different parts of Victoria. In this paper fire frequency curves (FFCs) were derived based on forest fire danger index (FFDI). FFDI is a measure related to fire initiation, spreading speed and containment difficulty. The mean temperature (T), relative humidity (RH) and areal extent of open water (LC2) during summer months (Dec-Feb) were identified as the most important parameters for assessing the risk of occurrence of bushfire. Based on these parameters, Andrews' curve equation was applied to 40 selected meteorological stations to identify homogenous stations to form unique clusters. A methodology using peak FFDI from cluster averaged FFDIs was developed by applying Log Pearson Type III (LPIII) distribution to generate FFCs. A total of nine homogeneous clusters across Victoria were identified, and subsequently their FFC's were developed in order to estimate the regionalised fire occurrence characteristics.

  18. Art at Second Hand: Prints after European Pictures in Victoria before 1870

    Directory of Open Access Journals (Sweden)

    Alison Inglis


    Full Text Available This article examines the significance of the large number of European reproductive prints present in the public and private art collections of early colonial Victoria. Several factors are identified as contributing to this popularity; ranging from the suitability of the print medium for the export market to the existence of informed print connoisseurs amongst colonial collectors and artists. This article also demonstrates some of the typical features of Australian art history; in that it is concerned with the evaluation of the Australian art world through reference to European culture (the centre-periphery debate and also that it limits its discussion to the art of a particular Australian state (Victoria. The nineteenth-century division of Australia into different colonies had ramifications for Australian art history that continue to the present day – namely; the tendency to interpret colonial artistic activities from a regional perspective.

  19. ZnO-Fe2O3 heterojunction for photocatalytic degradation of victoria blue dye (United States)

    Kumar, Pushpendra; Khatri, Taslimahemad; Bawa, Harpreet; Kaur, Jashandeep


    In the present study, ZnO-Fe2O3 heterojunction has been successfully synthesized by co-precipitation method for photocatalytic degradation of Victoria blue dye. The synthesized samples were subjected to XRD for microstructural characterization and scanning electron microscopy for morphological investigation. The typical X-ray diffraction pattern shows exhaustive evolution of hexagonal wurtzite phase of ZnO and α-Fe2O3 having crystalline in the range of 34-54 nm. The synthesized samples were applied for degradation of victoria blue dye under UV illumination. ZnO-Fe2O3 heterojunction showed higher photocatalytic activity for dye degradation compared to bare ZnO. This rise in photocatalytic activity can be attributed to enhanced charge separation derived from coupling of ZnO and Fe2O3. In this manuscript, the effect of photocatalyst dose, irradiation time and initial dye concentration on photodegradation of dye is reported in detail.

  20. Strain and displacement measurements for the June 9, 1980 Victoria, Mexico Earthquake (United States)

    Darby, D.; Nyland, E.; Suarez, F.; Chavez, D.; Gonzalez, J.

    A microgeodetic network 22 km south east of Est. Guadalupe Victoria, Baja California Norte, installed in late May 1980, has been resurveyed in an experiment that started 12 hours after the June 9, 1980 Victoria earthquake, which had an epicenter at 10 km depth about 12 km from the network. The resurvey was complete by June 13. Both the initial observations and the resurvey were done with HP3800 distance meter equipment. Some angular control was provided with a Wild T3 theodolite. The network underwent a compressive strain of 7 ± 3 micro strain essentially parallel the Cerro Prieto fault about the time of the earthquake. Strains of this size are associated with simple dislocation models of earthquakes of this magnitude. Its direction appears to be anomalous however. This may indicate compression related to soil liquefaction processes or strain near the end of the slip plane.

  1. Pancreatic tissue fluid pressure during drainage operations for chronic pancreatitis

    DEFF Research Database (Denmark)

    Ebbehøj, N; Borly, L; Madsen, P


    Pancreatic tissue fluid pressure was measured in 10 patients undergoing drainage operations for painful chronic pancreatitis. The pressure was measured by the needle technique in the three anatomic regions of the pancreas before and at different stages of the drainage procedure, and the results...... a decrease in pancreatic tissue fluid pressure during drainage operations for pain in chronic pancreatitis. Regional pressure decrease were apparently unrelated to ERCP findings....

  2. Spatio-Temporal Variation in Water Quality of Orle River Basin, S.W. ...

    African Journals Online (AJOL)



    Apr 19, 2011 ... roles that influence the ability of an aquatic ecosystem to sustain life forms .... The impact of environmental hydrogen-ion concentration (pH) on the water chemistry of the drainage basin was equally examined. Results of the .... activity of fertilizer applications and bush clearing and subsequent leaf litter.

  3. Vegetation-environment relationships in zero-order basins in coastal Oregon. (United States)

    Chris D. Sheridan; Thomas A. Spies


    Zero-order basins, where hillslope topography converges to form drainages, are common in steep, forested landscapes but we know little about their ecological structure. We used indirect gradient analysis to characterize gradients in plant species composition and cluster analysis to characterize groups of plant species associated with specific geomorphic areas. We...

  4. Hydroclimatic change disparity of Peruvian Pacific drainage catchments (United States)

    Rau, Pedro; Bourrel, Luc; Labat, David; Frappart, Frédéric; Ruelland, Denis; Lavado, Waldo; Dewitte, Boris; Felipe, Oscar


    Peruvian Pacific drainage catchments only benefit from 2% of the total national available freshwater while they concentrate almost 50% of the population of the country. This situation is likely to lead a severe water scarcity and also constitutes an obstacle to economic development. Catchment runoff fluctuations in response to climate variability and/or human activities can be reflected in extreme events, representing a serious concern (like floods, erosion, droughts) in the study area. To document this crucial issue for Peru, we present here an insightful analysis of the water quantity resource variability of this region, exploring the links between this variability and climate and/or anthropogenic pressure. We first present a detailed analysis of the hydroclimatologic variability at annual timescale and at basin scale over the 1970-2008 period. In addition to corroborating the influence of extreme El Niño events over precipitation and runoff in northern catchments, a mean warming of 0.2 °C per decade over all catchments was found. Also, higher values of temperature and potential and actual evapotranspiration were found over northern latitudes. We chose to apply the Budyko-Zhang framework that characterizes the water cycle as a function of climate only, allowing the identification of catchments with significant climatic and anthropogenic influence on water balance. The Budyko-Zhang methodology revealed that 11 out of 26 initial catchments are characterized by low water balance disparity related to minor climatic and anthropogenic influence. These 11 catchments were suitable for identifying catchments with contrasting change in their hydroclimatic behavior using the Budyko trajectories. Our analysis further reveals that six hydrological catchment responses can be characterized by high sensitivity to climate variability and land use changes.

  5. Imperialist women in Edwardian Britain : the Victoria League, 1899-1914


    Riedi, Elizabeth L.


    This thesis, based on private papers, society records, autobiographies and memoirs, newspapers and periodicals, examines one mainly female imperialist organisation - the Victoria League - and the women who ran it. It considers two related questions - what made Edwardian women imperialist, and how, within the limits of Edwardian society, could they express their imperialism? The thesis shows that several of the League's founders and executive had visited South Africa during or s...

  6. Lake Victoria wetlands and the ecology of the Nile tilapia, Oreochromis niloticus Linne


    Balirwa, J.S.


    An ecological study of wetlands was undertaken in northern Lake Victoria (East Africa) between 1993 and 1996 with a major aim of characterising shallow vegetation-dominated interface habitats, and evaluating their importance for fish, in particular, for the stocked and socio-economically important Oreochromis niloticus LINNÉ (the Nile tilapia). From field and laboratory experiments, five major habitat types could be defined by the type of the dominant emergent ma...

  7. Intestinal schistosomiasis among preschool children along the shores of Lake Victoria in Uganda

    DEFF Research Database (Denmark)

    Nalugwa, A.; Olsen, Annette; Tukahebwa, M. E.


    prevalence and intensity of infection were examined in 3058 children from 5 districts along Lake Victoria shoreline, eastern Uganda. For each child one stool sample was collected on three consecutive days. The Kato-Katz technique was used to prepare stool smears on slides for microscopic examination. Short...... for schistosomiasis takes preschool children into consideration and that health education on transmission of schistosomiasis is delivered to the endemic communities regularly....

  8. A Bottom-Up Understanding of Illegal, Unreported, and Unregulated Fishing in Lake Victoria

    Directory of Open Access Journals (Sweden)

    Joseph Luomba


    Full Text Available Illegal, unreported, and unregulated (IUU fishing is a major concern in fisheries management around the world. Several measures have been taken to address the problem. In Lake Victoria, the alleviation of IUU fishing is implemented through the Regional Plan of Action (RPOA-IUU, which restricts use of certain fishing gear, as well as prohibits fishing in closed areas and during closed seasons. Despite the long-term efforts to monitor and control what goes on in the fisheries, IUU fishing has persisted in Lake Victoria. Inspired by interactive governance theory, this paper argues that the persistence of IUU fishing could be due to different images that stakeholders have about the situation, rather than the lack of management competency. Through structured interviews with 150 fisheries stakeholders on Ijinga Island in the southeastern part of Lake Victoria, Tanzania, using paired comparison questionnaires, the study elicits stakeholders’ perspective about the severity of different locally-pertinent fishing-related activities. The results show that while fisheries stakeholder groups agree on their judgments about certain fishing gears, some differences are also apparent. For instance, fisheries managers and scientists do not always agree with fishing people about what activities cause the most damage to fisheries resources and ecosystem. Further, they tend to consider some IUU fishing-related activities less damaging than some non-IUU fishing. Such disparity creates governability challenges, pointing to the need to revisit relevant regulatory measures and to make them consistent with the knowledge and judgments of all stakeholders. Based on these findings, we discuss governing interventions that may contribute to addressing IUU fishing in Lake Victoria and elsewhere.

  9. A Comparison of digestive Tract Morphology in muskoxen and caribou from Victoria Island, Northwest Territories, Canada

    Directory of Open Access Journals (Sweden)

    Hans Staaland


    Full Text Available Although caribou and muskoxen coexist in close proximity on southeastern Victoria Island, they appear primarily adapted to different diets and foraging strategies. Visual inspection and analysis of rumen contents for fiber and lignin from the study (unpubl. also indicate a predominantly graminoid diet in the muskoxen and a more varied diet with a substantial browse component in the caribou.This should reduce the likelihood of competition for limited food resources in winter.

  10. B chromosomes have a functional effect on female sex determination in Lake Victoria cichlid fishes.

    Directory of Open Access Journals (Sweden)

    Kohta Yoshida


    Full Text Available The endemic cichlid fishes in Lake Victoria are a model system for speciation through adaptive radiation. Although the evolution of the sex-determination system may also play a role in speciation, little is known about the sex-determination system of Lake Victoria cichlids. To understand the evolution of the sex-determination system in these fish, we performed cytogenetic analysis in 11 cichlid species from Lake Victoria. B chromosomes, which are present in addition to standard chromosomes, were found at a high prevalence rate (85% in these cichlids. In one species, B chromosomes were female-specific. Cross-breeding using females with and without the B chromosomes demonstrated that the presence of the B chromosomes leads to a female-biased sex ratio in this species. Although B chromosomes were believed to be selfish genetic elements with little effect on phenotype and to lack protein-coding genes, the present study provides evidence that B chromosomes have a functional effect on female sex determination. FISH analysis using a BAC clone containing B chromosome DNA suggested that the B chromosomes are derived from sex chromosomes. Determination of the nucleotide sequences of this clone (104.5 kb revealed the presence of several protein-coding genes in the B chromosome, suggesting that B chromosomes have the potential to contain functional genes. Because some sex chromosomes in amphibians and arthropods are thought to be derived from B chromosomes, the B chromosomes in Lake Victoria cichlids may represent an evolutionary transition toward the generation of sex chromosomes.

  11. Salinity in Water Markets : An ExperimentalInvestigation of the Sunraysia Salinity Levy, Victoria


    C. Duke; L. Gangadharan


    Irrigation can have a significant negative impact on the environment. Irrigation impacts contribute a significant portion to the estimated forty six million dollar cost per annum of salinity in the Murray River, Australia. Policies available to regulators include externality taxes and levies. In 2002 the Victorian Government introduced a system of salinity levies in the irrigation regions of Sunraysia, northern Victoria. These levies differ from typical taxes because they also introduce trade...

  12. Satellite-Based Assessment of the spatial extent of Aquatic Vegetation in Lake Victoria (United States)

    Clark, W.; Aligeti, N.; Jeyaprakash, T.; Martins, M.; Stodghill, J.; Winstanley, H.


    Lake Victoria in Africa is the second largest freshwater lake in the world and is known for its abundance of aquatic wildlife. In particular over 200 different fish species are caught and sold by local fisherman. The lake is a major contributor to the local economy as a corridor of transportation, source of drinking water, and source of hydropower. However, the invasion of aquatic vegetation such as water hyacinth in the lake has disrupted each of these markets. Aquatic vegetation now covers a substantial area of the coastline blocking waterways, disrupting hydropower, hindering the collection of drinking water and decreasing the profitability of fishing. The vegetation serves as a habitat for disease carrying mosquitoes as well as snakes and snails that spread the parasitic disease bilharzia. The current control measures of invasive aquatic vegetation rely on biological, chemical and mechanical control. The objective of this study was to utilize remote sensing to map aquatic vegetation within Lake Victoria from 2000 to 2011. MODIS, Landsat 4-5TM, and Landsat 7-ETM imagery was employed to perform change detections in vegetation and identify the extent of aquatic vegetation throughout the years. The efficiency of containment efforts were evaluated and ideal time for application of such efforts were suggested. A methodology for aquatic vegetation surveillance was created. The results of this project were presented as a workshop to the Lake Victoria Fisheries Organization, SERVIR, and other partner organizations. The workshop provided instruction into the use of NASA and other satellite derived products. Time series animations of the spatial extent of aquatic vegetation within the lake were created. By identifying seasons of decreased aquatic vegetation, ideal times to employ control efforts were identified. SERVIR will subsequently utilize the methodologies and mapping results of this study to develop operational aquatic vegetation surveillance for Lake Victoria.

  13. B chromosomes have a functional effect on female sex determination in Lake Victoria cichlid fishes. (United States)

    Yoshida, Kohta; Terai, Yohey; Mizoiri, Shinji; Aibara, Mitsuto; Nishihara, Hidenori; Watanabe, Masakatsu; Kuroiwa, Asato; Hirai, Hirohisa; Hirai, Yuriko; Matsuda, Yoichi; Okada, Norihiro


    The endemic cichlid fishes in Lake Victoria are a model system for speciation through adaptive radiation. Although the evolution of the sex-determination system may also play a role in speciation, little is known about the sex-determination system of Lake Victoria cichlids. To understand the evolution of the sex-determination system in these fish, we performed cytogenetic analysis in 11 cichlid species from Lake Victoria. B chromosomes, which are present in addition to standard chromosomes, were found at a high prevalence rate (85%) in these cichlids. In one species, B chromosomes were female-specific. Cross-breeding using females with and without the B chromosomes demonstrated that the presence of the B chromosomes leads to a female-biased sex ratio in this species. Although B chromosomes were believed to be selfish genetic elements with little effect on phenotype and to lack protein-coding genes, the present study provides evidence that B chromosomes have a functional effect on female sex determination. FISH analysis using a BAC clone containing B chromosome DNA suggested that the B chromosomes are derived from sex chromosomes. Determination of the nucleotide sequences of this clone (104.5 kb) revealed the presence of several protein-coding genes in the B chromosome, suggesting that B chromosomes have the potential to contain functional genes. Because some sex chromosomes in amphibians and arthropods are thought to be derived from B chromosomes, the B chromosomes in Lake Victoria cichlids may represent an evolutionary transition toward the generation of sex chromosomes.

  14. Leuconidae (Crustacea: Cumacea) from the collections of the Museum Victoria, Australia. (United States)

    Gerken, Sarah


    The collections of the Museum Victoria have yielded six new leuconid species in five genera from Australian waters: Austroleucon adiazetos n. sp., A. dolosolevis n. sp., Eudorellopsis mykteros n. sp., Kontiloleucon australiensis n. gen., n. sp., Leucon (Alytoleucon) dolichorhinos n. sp., Ommatoleucon megalopos n. sp. as well as the new genus Kontiloleucon. Leucon (Leucon) echinolophotos n. sp. is a new species from off Enderby Land, Antarctica. Keys to the Australian leuconid genera and species are included.

  15. Displacement Processes in Stable Drainage Fronts (United States)

    Breen, S. J.; Pride, S. R.; Manga, M.


    Drainage fronts are stabilized at large bond number, when a low density nonwetting fluid displaces a high density wetting fluid from above. This is an ideal flow scenario for studying the correspondence between pore scale processes and continuum models because the front is a persistent macroscale feature that is propagated by discrete, multiplepore scale displacements. We present new observations of stable air/water drainage in thin, threedimensional, poured bead packs at varying capillary number. With backlighting and a high speed camera, we observe short range front velocities that are an order of magnitude larger than bulk pore velocity, consistent with previous studies in ordered 2D structures. We also quantify displacement lengths and front width. For comparison to continuum simulations, we measure saturation by light transmission continuously over a series of 1 cm length voxels. We focus on the critical nonwetting saturation (CNS, or "emergence point") at which voxels are percolated by air and continuum air permeability becomes nonzero. We find that mean CNS is capillary number dependent even at large bond number, with larger CNS at lower capillary number. Continuum simulations with an equivalent discretization demonstrate that CNS is a significant source of uncertainty for predictions of the time and saturation profile at chamber-length air breakthrough.

  16. Bioreactor for acid mine drainage control (United States)

    Zaluski, Marek H.; Manchester, Kenneth R.


    A bioreactor for reacting an aqueous heavy metal and sulfate containing mine drainage solution with sulfate reducing bacteria to produce heavy metal sulfides and reduce the sulfuric acid content of the solution. The reactor is an elongated, horizontal trough defining an inlet section and a reaction section. An inlet manifold adjacent the inlet section distributes aqueous mine drainage solution into the inlet section for flow through the inlet section and reaction section. A sulfate reducing bacteria and bacteria nutrient composition in the inlet section provides sulfate reducing bacteria that with the sulfuric acid and heavy metals in the solution to form solid metal sulfides. The sulfate reducing bacteria and bacteria nutrient composition is retained in the cells of a honeycomb structure formed of cellular honeycomb panels mounted in the reactor inlet section. The honeycomb panels extend upwardly in the inlet section at an acute angle with respect to the horizontal. The cells defined in each panel are thereby offset with respect to the honeycomb cells in each adjacent panel in order to define a tortuous path for the flow of the aqueous solution.

  17. Floating roof tank drainage system improvements

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca, Wagner Andrade da; Holdack, Ricardo; Ruza, Adilson; Schraml, Karina Chacur; Fujikawa, Mauro Yutaka [Petrobras Transporte S.A. (TRANSPETRO), Rio de Janeiro, RJ (Brazil); Silva, Adilson Batista da [ATP Engenharia Ltda., Parnamirim, RN (Brazil)


    TRANSPETRO's tank TQ-8803 is a floating roof tank, used for storing gasoline at atmospheric pressure. This tank presented a roof movement restriction at a certain height in the receiving and sending operations, besides problems in draining the rainwater from the floating roof. The roof drain was a central articulated pipe, with a single intake spot. The tank had an anti-rotational 12-inch guide tube and a separate 8-inch gauging tube. It was verified that there were signs of friction between the tubes and their nozzles, and that both the tubes were out of plummet. The solution was removing both the tubes and installing a single anti-rotational guide tube, which received the level and temperature gauges, besides being used for manual gauging and as sampling nozzle. A new drainage system was also projected. It uses a flexible tube, supported in a spiral form on the bottom of the tank, and has a main and four auxiliary drainage boxes, positioned in the center of the roof and next to the pontoon, below the mobile stairs. These boxes were provided with elastomer duckbill check valves, substituting the swing check valves previously installed. After the maintenance conclusion, the anomalies found before were solved. (author)


    Directory of Open Access Journals (Sweden)



    Full Text Available Jijia river basin surface geographically fits in Moldavian Plateau, Plain of Moldavia subunit. Being lowered by 200 to 300 m compared to adjacent subunits, it appears as a depression with altitudes between 270-300 m.Through its position in the extra-Carpathian region, away from the influence of oceanic air masses, but wide open to the action of air masses of eastern, north-eastern and northern continental origin, Jijia basin receives precipitations which vary according to the average altitude differing from the northern to the southern part of the basin (564 mm in north, 529.4 mm in Iasi. A characteristic phenomenon to the climate is represented by the torrential rains in the hot season, under the form of rain showers with great intensity, fact that influences the drainage of basin rivers. Jijia hydrographic basin is characterized by frequent and sharp variations of flow volumes and levels which lead to floods and flooding throughout the basin. The high waters generally occur between March and June, when approximately 70% of the annual stock is transported. The paper analyzes the main causes and consequences of flooding in the studied area, also identifying some structural and non-structural measures of flood protection applied by authorities in Jijia hydrographic basin. As a case study, the flood recorded in Dorohoi in June 28-29, 2010 is presented.

  19. Study of Basin Recession Characteristics and Groundwater Storage Properties (United States)

    Yen-Bo, Chen; Cheng-Haw, Lee


    Stream flow and groundwater storage are freshwater resources that human live on.In this study, we discuss southern area basin recession characteristics and Kao-Ping River basin groundwater storage, and hope to supply reference to Taiwan water resource management. The first part of this study is about recession characteristics. We apply Brutsaert (2008) low flow analysis model to establish two recession data pieces sifting models, including low flow steady period model and normal condition model. Within individual event analysis, group event analysis and southern area basin recession assessment, stream flow and base flow recession characteristics are parameterized. The second part of this study is about groundwater storage. Among main basin in southern Taiwan, there are sufficient stream flow and precipitation gaging station data about Kao-Ping River basin and extensive drainage data, and data about different hydrological characteristics between upstream and downstream area. Therefore, this study focuses on Kao-Ping River basin and accesses groundwater storage properties. Taking residue of groundwater volume in dry season into consideration, we use base flow hydrograph to access periodical property of groundwater storage, in order to establish hydrological period conceptual model. With groundwater storage and precipitation accumulative linearity quantified by hydrological period conceptual model, their periodical changing and alternation trend properties in each drainage areas of Kao-Ping River basin have been estimated. Results of this study showed that the recession time of stream flow is related to initial flow rate of the recession events. The recession time index is lower when the flow is stream flow, not base flow, and the recession time index is higher in low flow steady flow period than in normal recession condition. By applying hydrological period conceptual model, groundwater storage could explicitly be analyzed and compared with precipitation, by only

  20. Genetic structure of pelagic and littoral cichlid fishes from Lake Victoria.

    Directory of Open Access Journals (Sweden)

    Miyuki Takeda

    Full Text Available The approximately 700 species of cichlids found in Lake Victoria in East Africa are thought to have evolved over a short period of time, and they represent one of the largest known examples of adaptive radiation. To understand the processes that are driving this spectacular radiation, we must determine the present genetic structure of these species and elucidate how this structure relates to the ecological conditions that caused their adaptation. We analyzed the genetic structure of two pelagic and seven littoral species sampled from the southeast area of Lake Victoria using sequences from the mtDNA control region and 12 microsatellite loci as markers. Using a Bayesian model-based clustering method to analyze the microsatellite data, we separated these nine species into four groups: one group composed of pelagic species and another three groups composed mainly of rocky-shore species. Furthermore, we found significant levels of genetic variation between species within each group at both marker loci using analysis of molecular variance (AMOVA, although the nine species often shared mtDNA haplotypes. We also found significant levels of genetic variation between populations within species. These results suggest that initial groupings, some of which appear to have been related to habitat differences, as well as divergence between species within groups took place among the cichlid species of Lake Victoria.