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Sample records for finniss river northern

  1. Recovery of fish communities in the Finniss River, northern Australia, following remediation of the Rum Jungle uranium/copper mine site.

    Science.gov (United States)

    Jeffree, R A; Twining, J R; Thomson, J

    2001-07-15

    The Finniss River in the wet-dry tropics of northern Australia has received acid rock drainage (ARD) contaminants from the Rum Jungle uranium/copper mine site over more than four decades. Annual-cycle loads of Cu, Zn, Mn, and sulfate, calculated from daily water and flow measurements, have been determined both prior to and following mine-site remediation, that began in the early 1980s. The effects of varying contaminant loads on the relative abundances of seven fish species, sampled by enmeshing nets during dry seasons, were determined by nonmetric multidimensional scaling (nMDS), in combination with cluster-analysis and other nonparametric statistical techniques. These analyses showed that (i) prior to remediation, the impacted region of the Finniss River in 1974 had significantly dissimilar (P < 0.001) and more heterogeneous fish communities, generally characterized by reduced diversity and abundance, compared to sites unexposed to elevated contaminant water concentrations and (ii) postremediation, recovery in fish communities from the impacted region was indicated because they were not significantly dissimilar from those sampled at contemporary (P = 0.16) unimpacted sites, that were also similar to preremedial unimpacted sites. Even though considerable contaminant loads are still being delivered to the impacted region of the Finniss River over the annual cycle, the recovery in fish diversity and abundances is consistent with (a) reductions of in situ contaminant water concentrations at the time of fish sampling, (b) reductions in annual-cycle contaminant loads of sulfate, Cu, Zn, and Mn by factors of 3-7, (c) greatly reduced frequencies of occurrence and magnitude of elevated contaminant water concentrations over the annual cycle, that was most pronounced for Cu, and (d) the absence of extensive fish-kills during the first-flushes of contaminants into the Finniss river proper at the beginning of the wet season, that were observed prior to remediation. As such

  2. Northern Manitoba, northern Saskatchewan, and the Saskatchewan River Delta: Waterfowl production survey: 2000

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the Waterfowl Production and Habitat Survey for northern Manitoba, northern Saskatchewan, and the Saskatchewan River Delta during 2000. The...

  3. Waterfowl production survey: Northern Saskatchewan, northern Manitoba, Saskatchewan River Delta: July 10-22, 1973

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the Waterfowl Production and Habitat Survey for northern Saskatchewan, northern Manitoba, and the Saskatchewan River Delta during 1973. The...

  4. Northern Manitoba, northern Saskatchewan, and the Saskatchewan River Delta: Waterfowl production survey: 1993

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the Waterfowl Production and Habitat Survey for northern Manitoba, northern Saskatchewan, and the Saskatchewan River Delta during 1993. The...

  5. Freshwater bivalve shells as archival indicators of metal pollution from a copper-uranium mine in tropical northern Australia.

    Science.gov (United States)

    Markich, Scott J; Jeffree, Ross A; Burke, Patrick T

    2002-03-01

    Freshwater bivalves (Velesunio angasi) were sampled in 1996 from the Finniss River in tropical northern Australia at 10 sites a priori exposed and nonexposed to acid rock drainage (ARD), containing elevated metal concentrations, from the rehabilitated Rum Jungle copper-uranium mine. Secondary ion mass spectrometry (SIMS) was used to measure Cu, Mn, Zn, U, Ni, Co, Pb, and Fe/Ca ratios across the annual shell laminations of the longest-lived bivalves found at each site, with the aim of evaluating the ability of the shells to archive measured annual metal inputs and their temporal patterns. At sites not contaminated by ARD, relatively constant and similar (baseline) SIMS signals were found for all metals in the shell laminations of V. angasi, dating as far back as 1965. At sites contaminated by ARD, relatively constant, but variably elevated, SIMS signals were evident for Cu, Mn, Zn, Ni, and Co in the shell, which extended back to the end of rehabilitation (1986) only. Since rehabilitation, the temporal patterns of Cu, Zn, and Mn observed in the shells at the most contaminated sites reflected those of the measured annual dissolved loads in the surface waters. The average concentrations of Cu, Mn, Zn, Ni, and Co in the shells decreased (3-13-fold) with increasing distance downstream of the mine site, until concentrations characteristic of the noncontaminated sites were reached. This geographic pattern of decline in pollution signal in the shell with increasing distance downstream of the pollution input is consistent with the pattern established for water and sediment chemistry. Overall, the SIMS results support the proposition that the shells of V. angasi can be used as archival indicators of metal pollution in surface waters of the Finniss River over their lifetime.

  6. Modeling annual discharge of six Mexico’s northern rivers

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    Jose de Jesus Navar

    2012-04-01

    Full Text Available The overall goal of this report was to understand river discharge variability to improve conventional water management practices of Mexico’s northern subtropical rivers. This report addresses whether: a river discharge tendencies, patterns and cycles can be detected with proxy and instrumental records; and b annual discharge can be forecasted by stochastic models. Eleven gauging stations of six major rivers; three lowland rivers discharging into the Pacific Ocean (Rios Santa Cruz, Acaponeta, and San Pedro; five upland rivers draining into the Pacific Ocean (Rio San Pedro: Peña del Aguila, Refugio Salcido, San Felipe, Vicente Guerrero and Saltito, one river flowing across the interior Basin (Rio Nazas: Salomé Acosta and two more rivers discharging into the Northern Gulf of Mexico (Rio San Juan: El Cuchillo and Rio Ramos: Pablillos were statistically analyzed. Instrumental recorded daily discharge data (1940-1999 and reconstructed time series data (1860-1940 using dendrochronological analysis delivered annual discharge data to be modeled using autoregressive integrated moving average, ARIMA models. Spectral density analysis, autocorrelation functions and the standardized annual discharge data evaluated annual discharge frequency cycles. Results showed ARIMA models with two autoregressive and one moving average coefficient adequately project river discharge for all gauging stations with four of them showing significant declining patterns since 1860. ARIMA models in combination with autocorrelation and spectral density techniques as well as standardized departures, in agreement with present (2002-2010 observations, forecast a wet episode that may last between 9 and 12 years thereafter entering again into a dry episode. Three dry-wet spell cycles with different time scales (1-2 years; 4-7 years; 9-12 years could be discerned from these analyses that are consistent for all three northern Mexico’s river clusters that emerged from a multivariate

  7. Northern Manitoba, northern Saskatchewan, and the Saskatchewan River Delta: Waterfowl production survey: July 5-23, 1983

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the Waterfowl Production and Habitat Survey for northern Manitoba, northern Saskatchewan, and the Saskatchewan River Delta during 1983. The...

  8. Recent trends and variability in river discharge across northern Canada

    Science.gov (United States)

    Déry, Stephen J.; Stadnyk, Tricia A.; MacDonald, Matthew K.; Gauli-Sharma, Bunu

    2016-12-01

    This study presents an analysis of the observed inter-annual variability and inter-decadal trends in river discharge across northern Canada for 1964-2013. The 42 rivers chosen for this study span a combined gauged area of 5.26 × 106 km2 and are selected based on data availability and quality, gauged area and record length. Inter-annual variability in river discharge is greatest for the eastern Arctic Ocean (coefficient of variation, CV = 16 %) due to the Caniapiscau River diversion into the La Grande Rivière system for enhanced hydropower production. Variability is lowest for the study area as a whole (CV = 7 %). Based on the Mann-Kendall test (MKT), no significant (p > 0.05) trend in annual discharge from 1964 to 2013 is observed in the Bering Sea, western Arctic Ocean, western Hudson and James Bay, and Labrador Sea; for northern Canada as a whole, however, a statistically significant (p < 0.05) decline of 102.8 km3 25 yr-1 in discharge occurs over the first half of the study period followed by a statistically significant (p < 0.05) increase of 208.8 km3 25 yr-1 in the latter half. Increasing (decreasing) trends in river discharge to the eastern Hudson and James Bay (eastern Arctic Ocean) are largely explained by the Caniapiscau diversion to the La Grande Rivière system. Strong regional variations in seasonal trends of river discharge are observed, with overall winter (summer) flows increasing (decreasing, with the exception of the most recent decade) partly due to flow regulation and storage for enhanced hydropower production along the Hudson and James Bay, the eastern Arctic Ocean and Labrador Sea. Flow regulation also suppresses the natural variability of river discharge, particularly during cold seasons.

  9. Impacts of Climatic Change on River Runoff in Northern Xinjiang of China over Last Fifty Years

    Institute of Scientific and Technical Information of China (English)

    YANG Yuhui; CHEN Yaning; LI Weihong; WANG Minzhong; SUN Guili

    2010-01-01

    The characteristics of climatic change and river runoff, as well as the response of river runoff to climatic change in the northern Xinjiang are analyzed on the basis of the hydrological and meteorological data over the last 50 years by the methods of Mann-Kendall nonparametric test and the nonlinear regression model. The results show that: 1) The temperature and the precipitation increased significantly in the whole northern Xinjiang, but the precipitation displayed no obvious change, or even a decreasing trend in the northern mountainous area of the northern Xinjiang. 2) River runoff varied in different regions in the northern Xinjiang. It significantly increased in the northern slope of the Tianshan Mountains and the north of the northern Xinjiang (p=0.05), while slightly increased in the west of the northern Xinjiang. 3) North Atlantic Oscillation (NAO) affects river runoff by influencing temperature and precipita-tion. The NAO and precipitation had apparent significant correlations with the river runoff, but the temperature did not in the northern Xinjiang. Since the mid-1990s river runoff increase was mainly caused by the increasing temperature in the northern slope of the Tianshan Mountains and the north of the northern Xinjiang. Increased precipitation resulted in increased river runoff in the west of the northern Xinjiang.

  10. CEPF Western Ghats Special Series: Fish fauna of Indrayani River, northern Western Ghats, India

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    Neelesh Dahanukar

    2012-01-01

    Full Text Available The freshwater fish fauna of the Indrayani River, a northern tributary of the Krishna River system in the Western Ghats of India was studied. A total of 57 species of freshwater fish belonging to 18 families and 39 genera were recorded. However, based on the previous literature it is possible that the Indrayani River harbours around 67 species. Out of the 57 species in the present collection, 12 are endemic to the Western Ghats while six are endemic to the Krishna River system. Neotropius khavalchor, an endemic fish of the Krishna River system, was recorded for the first time from the northern tributaries. The fish fauna of the Indrayani River is threatened due to seven introduced species and anthropogenic activities such as deforestation leading to siltation, tourism, sand mining, over fishing and organic and inorganic pollution. Since the Indrayani River hosts endemic and threatened species, including Glyptothorax poonaensis, conservation measures to ensure habitat protection in the river are essential.

  11. River sedimentation and channel bed characteristics in northern Ethiopia

    Science.gov (United States)

    Demissie, Biadgilgn; Billi, Paolo; Frankl, Amaury; Haile, Mitiku; Lanckriet, Sil; Nyssen, Jan

    2016-04-01

    Excessive sedimentation and flood hazard are common in ephemeral streams which are characterized by flashy floods. The purposes of this study was to investigate the temporal variability of bio-climatic factors in controlling sediment supply to downstream channel reaches and the effect of bridges on local hydro-geomorphic conditions in causing the excess sedimentation and flood hazard in ephemeral rivers of the Raya graben (northern Ethiopia). Normalized Difference Vegetation Index (NDVI) was analyzed for the study area using Landsat imageries of 1972, 1986, 2000, 2005, 2010, and 2012). Middle term, 1993-2011, daily rainfall data of three meteorological stations, namely, Alamata, Korem and Maychew, were considered to analyse the temporal trends and to calculate the return time intervals of rainfall intensity in 24 hours for 2, 5, 10 and 20 years using the log-normal and the Gumbel extreme events method. Streambed gradient and bed material grain size were measured in 22 river reaches (at bridges and upstream). In the study catchments, the maximum NDVI values were recorded in the time interval from 2000 to 2010, i.e. the decade during which the study bridges experienced the most severe excess sedimentation problems. The time series analysis for a few rainfall parameters do not show any evidence of rainfall pattern accountable for an increase in sediment delivery from the headwaters nor for the generation of higher floods with larger bedload transport capacities. Stream bed gradient and bed material grain size data were measured in order to investigate the effect of the marked decrease in width from the wide upstream channels to the narrow recently constructed bridges. The study found the narrowing of the channels due to the bridges as the main cause of the thick sedimentation that has been clogging the study bridges and increasing the frequency of overbank flows during the last 15 years. Key terms: sedimentation, ephemeral streams, sediment size, bridge clogging

  12. River capture and sediment redistribution in northern Tunisia: The doom of Utica

    Science.gov (United States)

    Booth-Rea, Guillermo; Camafort, Miquel; Pérez-Peña, J. Vicente; Melki, Fetheddine; Ranero, César; Azañón, José Miguel; Gracia, Eulalia; Ouadday, Mohamed

    2016-04-01

    Utica was a flourishing port city in northern Tunisia since the Phoenician times, 12-9th century B.C., until the 4th century A.D.. However, at present it is located 10 km from the coastline after very fast late Holocene progradation of the Mejerda River delta into the bay of Utica. This fast delta progradation occurred after Mejerda River captured Tine River increasing 140 % the river catchment area. Charcoal fragments present in the youngest Tine river terrace at the wind gap give a conventional radiocarbon age of 3240 +/- 30yr BP, indicating that the capture occurred after this date. Quaternary fluvial terraces located in the Tine River paleovalley have been folded and uplifted above a fold related to the active El Alia Tebousouk reverse fault (ETF). Continued uplift of the Tine River valley above the ETF favoured headward erosion of the Medjerda river tributaries creating a transverse drainage that captured Tine River. This capture produced an important change in sediment discharge along the northern Tunisia coast driving sediments to the Gulf of Tunis instead of feeding the Tyrrhenian Sea through the Ichkeul and Bizerte lakes. Although anthropogenic derived degradation of northern Tunisia land for agricultural purposes probably influenced the increase in sediment into the Utica bay, the main cause of rapid progradation of the Medjerda River delta during the late Holocene is related to its increase in drainage area after capturing the Tine River. This process was mostly driven by local contractive tectonics linked to the seismogenic Alia Tebousouk reverse fault.

  13. Review and analysis of existing Alberta data on drinking water quality and treatment facilities for the Northern River basins study. Northern River Basins Study project report No. 55

    Energy Technology Data Exchange (ETDEWEB)

    Prince, D.S.; Smith, D.W.; Stanley, S.J.

    1995-12-31

    This report summarizes the results of a project conducted to gather existing information about drinking water quality, drinking water facilities, and water treatment effectiveness in the area covered by the Northern River Basins Study (Peace, Slave, and Athabasca River basins in northern Alberta). The report includes a comparison of water treatment performance to the Canada Drinking Water Quality Guidelines. The appendices contain summaries of parameters in the treated water survey, of the comparisons between raw and treated water, and of samples not meeting the Guidelines, as well as an inventory of treatment facilities giving facility name and location, water source, community population, treatment method used, raw storage capacity, and treated volumes.

  14. Trends in the occurrence of human and veterinary antibiotics in the sediments of the Yellow River, Hai River and Liao River in northern China

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Lijun [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Ying Guangguo, E-mail: guang-guo.ying@gig.ac.cn [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Zhao Jianliang [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Yang Jifeng [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Chemistry and Chemical Engineering Department, Hunan University of Arts and Science, Changde 415000 (China); Wang Li; Yang Bin; Liu Shan [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China)

    2011-07-15

    The occurrence of four classes of 17 commonly used antibiotics (including fluoroquinolones, tetracycline, sulfonamides, and macrolides) was investigated in the sediments of the Yellow River, Hai River and Liao River in northern China by using rapid resolution liquid chromatography-tandem mass spectrometry. Higher concentrations were detected for most antibiotics in the sediments of the Hai River than in the sediments of the other rivers. Norfloxacin, ofloxacin, ciprofloxacin and oxytetracycline in the three rivers were most frequently detected with concentrations up to 5770, 1290, 653 and 652 ng/g, respectively. High frequencies and concentrations of the detected antibiotics were often found in the downstream of large cities and areas influenced by feedlot and fish ponds. Good fitted linear regression equations between antibiotic concentration and sediment physicochemical properties (TOC, texture and pH) were also found, indicating that sediment properties are important factors influencing the distribution of antibiotics in the sediment of rivers. - Highlights: > Presence of four classes of commonly used antibiotics in the river sediments. > Higher concentrations in the Hai River than in the Liao River and Yellow River. > Norfloxacin, ofloxacin, ciprofloxacin and oxytetracycline most frequently detected. > High antibiotic concentrations often found in the downstream of large cities. > River sediments are an important reservoir of antibiotics. - Higher concentrations of selected antibiotics were determined in the sediments of the Hai River than in the Liao River and Yellow River.

  15. Deconstructing methane emissions from a small Northern-European river: Hydrodynamics and temperature as key drivers

    OpenAIRE

    McGinnis, Daniel F.; Bilsley, Nicole; Schmidt, Mark; Fietzek, Peer; Bodmer, Pascal; Premke, Katrin; Lorke, Andreas; Flury, Sabine

    2016-01-01

    Methane (CH4) emissions from small rivers and streams, particularly via ebullition, are currently under-represented in the literature. Here, we quantify the methane effluxes and drivers in a small, Northern European river. Methane fluxes are comparable to those from tropical aquatic systems, with average emissions of 320 mg CH4 m-2 d-1. Two important drivers of methane flux variations were identified in the studied system: 1) temperature-driven sediment methane ebullition and 2) flow-dependen...

  16. Changes of organic phosphorus in river waters in northern Bangladesh

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    MJ Islam

    2015-12-01

    Full Text Available The variability in phosphorus concentrations and the decomposition rates of organic phosphorus were measured in five selected rivers through four surveys in July and November of 2012, and February and May of 2013. After collection the water samples were incubated for 20 days in a dark incubator and the change of forms of phosphorus such as particulate organic phosphorus (POP, dissolved organic phosphorus (DOP and dissolved inorganic phosphorus (DIP were analyzed. By fitting the changes to two types of models, the decomposition rates of organic phosphorus were determined. The mean total organic phosphorus (TOP decomposition rate coefficients in the studied rivers was 0.039 day-1. The average POP decomposition rate coefficient (POP→DOP→DIP model was 0.038 day-1 while the mean DOP decomposition rate coefficient was 0.251 day-1. The decomposition rate coefficients measured in this study might be applicable for modeling of river water quality.

  17. Mycobacterial infection in Northern snakehead (Channa argus) from the Potomac River catchment

    Science.gov (United States)

    Densmore, Christine L.; Iwanowicz, L.R.; Henderson, A.P.; Iwanowicz, D.D.; Odenkirk, J.S.

    2016-01-01

    The Northern snakehead, Channa argus (Cantor), is a non-native predatory fish that has become established regionally in some temperate freshwater habitats within the United States. Over the past decade, Northern snakehead populations have developed within aquatic ecosystems throughout the eastern USA, including the Potomac River system within Virginia, Maryland and Washington, D.C. Since this species was initially observed in this region in 2002, the population has expanded considerably (Odenkirk & Owens 2007). In the Chesapeake Bay watershed, populations of Northern snakehead exist in the lower Potomac River and Rappahannock Rivers on the Western shore of the Bay, and these fish have also been found in middle or upper reaches of river systems on the Eastern shore of the Bay, including the Nanticoke and Wicomico Rivers among others. Over the past several years, many aspects of Northern snakehead life history in the Potomac River have been described, including range and dispersal patterns, microhabitat selection and diet (Lapointe, Thorson & Angermeier 2010; Saylor, Lapointe & Angermeier 2012; Lapointe, Odenkirk & Angermeier 2013). However, comparatively little is known about their health status including susceptibility to parasitism and disease and their capacity to serve as reservoirs of disease for native wildlife. Although considered hardy by fisheries biologists, snakehead fish have demonstrated susceptibility to a number of described piscine diseases within their native range and habitat in Asia. Reported pathogens of significance in snakehead species in Asia include snakehead rhabdovirus (Lio-Po et al. 2000), aeromonad bacteria (Zheng, Cao & Yang 2012), Nocardia (Wang et al. 2007) andMycobacterium spp. (Chinabut, Limsuwan & Chantatchakool 1990; ). Mycobacterial isolates recovered from another snakehead species (Channa striata) in the previous studies have included M. marinum and M. fortuitum, as identified through molecular

  18. Isotopic evidence on multiple sources of nitrogen in the northern Jiulong River, Southeast China

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    Cao, Wenzhi; Huang, Zheng; Zhai, Weidong; Li, Ying; Hong, Huasheng

    2015-09-01

    Riverine export accounts for a large portion of estuarine and coastal nutrients and could lead to severe eutrophication. However, nitrogen (N) sources at the catchment scale remain unclear because of spatial and temporal variations. The stable isotope of 15N, which has been proven to be effective in deducing sources and testing biogeochemical behaviours, is applied in this study to explore multiple sources of riverine N and their nutrient concentrations in the northern section of Jiulong River catchment seasonally. Results show that drastic seasonal variation in external nitrate sources occurs in the river; manure and sewage dominate during base flows, whereas organic N in soil and atmospheric deposition dominate during storm flows. The external sources change throughout the year depending on the environmental conditions. Furthermore, riverine nitrate import in the northern Jiulong River is dominated by an external process because of the increasing NO3- - δ15N value accompanied by an increasing NO3- -N concentration (p management and eutrophication reversal.

  19. The role of tectonics and climate in the late Quaternary evolution of a northern Amazonian River

    Science.gov (United States)

    Cremon, Édipo Henrique; Rossetti, Dilce de Fátima; Sawakuchi, André de Oliveira; Cohen, Marcelo Cancela Lisboa

    2016-10-01

    The Amazon basin has most of the largest rivers of the world. However, works focusing the geological evolution of the trunk river or its tributaries have been only partly approached. The Branco River constitutes one of the main northern Amazonian tributaries. A previous work proposed that, before flowing southward into the Negro-Amazon Rivers, the Branco River had a southwest to northeast course into the Caribbean Sea. The present work aimed to establish if the proposed change in the course of this river is supported by morphological and sedimentological data. Other goals were to discuss the factors influencing river development and establish its evolution over time within the chronological framework provided by radiocarbon and optically stimulated luminescence dating. The work considered the entire course of the Branco River downstream of the Precambrian Guiana Shield, where the river presumably did not exist in ancient times. The river valley is incised into fluvial sedimentary units displaying ages between 100 and 250 ky old, which record active and abandoned channels, crevasse splay/levees, and point bars. The sedimentary deposits in the valley include two alluvial plain units as old as 18.7 ky and which intersects a Late Pleistocene residual megafan. These characteristics suggest that a long segment of the Branco River was established only a few thousand years ago. Together with several structural anomalies, these data are consistent with a mega-capture at the middle reach of this river due to tectonic reactivation in the Late Pleistocene. This integrated approach can be applied to other Amazonian tributaries to unravel how and when the Amazonian drainage basin became established.

  20. Heavy metals in northern Chilean rivers: spatial variation and temporal trends.

    Science.gov (United States)

    Pizarro, Jaime; Vergara, Pablo M; Rodríguez, José A; Valenzuela, Alejandra M

    2010-09-15

    Rivers of central-northern Chile are exposed to pollution from different sources, including mining activities, natural orogenic process, volcanic activity, and geology. In order to determine the contribution of mining to river pollution, the spatio-temporal dynamics of chemical species dissolved in 12 rivers of central-northern Chile was assessed. Of all the rivers studied, the Elqui showed the highest historical mean concentrations of As, Cu and Pb. The Aconcagua had the highest concentration of Hg and a large Cr concentration, while the Rapel showed elevated concentrations of Cu and Mo. The Elqui and the Aconcagua were clustered as distinct groups by a cluster analysis based on two independent principal components. Hierarchical Bayesian models showed annual trends but no seasonal effects in heavy metal concentrations. As and Cu in the Elqui had positive annual slopes. Sulphate concentration exceeded 100 mg L(-1) in nine rivers, and in seven of them it had positive annual slopes. Our findings suggest that mining pollution is the main process contributing to this increasing annual trend in As, Cu and SO(4)(2-). Therefore, in order to improve the water quality of these rivers it is necessary to identify the main sources of heavy metals associated with mining activities. Copyright 2010 Elsevier B.V. All rights reserved.

  1. Proglacial river stage, discharge, and temperature datasets from the Akuliarusiarsuup Kuua River northern tributary, Southwest Greenland, 2008–2011

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    A. K. Rennermalm

    2012-05-01

    Full Text Available Pressing scientific questions concerning the Greenland ice sheet's climatic sensitivity, hydrology, and contributions to current and future sea level rise require hydrological datasets to resolve. While direct observations of ice sheet meltwater losses can be obtained in terrestrial rivers draining the ice sheet and from lake levels, few such datasets exist. We present a new hydrologic dataset from previously unmonitored sites in the vicinity of Kangerlussuaq, Southwest Greenland. This dataset contains measurements of river stage and discharge for three sites along the Akuliarusiarsuup Kuua (Watson River's northern tributary, with 30 min temporal resolution between June 2008 and July 2011. Additional data of water temperature, air pressure, and lake stage are also provided. Flow velocity and depth measurements were collected at sites with incised bedrock or structurally reinforced channels to maximize data quality. However, like most proglacial rivers, high turbulence and bedload transport introduce considerable uncertainty to the derived discharge estimates. Eleven propagating error sources were quantified, and reveal that largest uncertainties are associated with flow depth observations. Mean discharge uncertainties (approximately the 68% confidence interval are two to four times larger (±19% to ±43% than previously published estimates for Greenland rivers. Despite these uncertainties, this dataset offers a rare collection of direct measurements of ice sheet runoff to the global ocean and is freely available for scientific use at http://dx.doi.org/10.1594/PANGAEA.762818.

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

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    Yuekui Ding

    2015-09-01

    Full Text Available We applied a river habitat quality (RHQ assessment method to the Hai River Basin (HRB; an important economic centre in China; to obtain baseline information for water quality improvement; river rehabilitation; and watershed management. The results of the assessment showed that the river habitat in the HRB is seriously degraded. Specifically; 42.41% of the sites; accounting for a river length of 3.31 × 104 km; were designated poor and bad. Habitat in the plain areas is seriously deteriorated; and nearly 50% of the sites; accounting for a river length of 1.65 × 104 km; had either poor or bad habitats. River habitat degradation was attributable to the limited width of the riparian zone (≤5 m; lower coverage of riparian vegetation (≤40%; artificial land use patterns (public and industrial land; frequent occurrence of farming on the river banks and high volumes of solid waste (nearly 10 m3; single flow channels; and rare aquatic plants (≤1 category. At the regional scale; intensive artificial land use types caused by urbanization had a significant impact on the RHQ in the HRB. RHQ was significantly and negatively correlated with farmland (r = 1.000; p < 0.01 and urban land (r = 0.998; p < 0.05; and was significantly and positively correlated with grassland and woodland (r = 1.000; p < 0.01. Intensive artificial land use; created through urbanization processes; has led to a loss of the riparian zone and its native vegetation; and has disrupted the lateral connectivity of the rivers. The degradation of the already essentially black rivers is exacerbated by poor longitudinal connectivity (index of connectivity is 2.08–16.56; caused by reservoirs and sluices. For river habitat rehabilitation to be successful; land use patterns need to be changed and reservoirs and sluices will have to be regulated.

  3. Flood of July 2016 in northern Wisconsin and the Bad River Reservation

    Science.gov (United States)

    Fitzpatrick, Faith A.; Dantoin, Eric D.; Tillison, Naomi; Watson, Kara M.; Waschbusch, Robert J.; Blount, James D.

    2017-06-06

    Heavy rain fell across northern Wisconsin and the Bad River Reservation on July 11, 2016, as a result of several rounds of thunderstorms. The storms caused major flooding in the Bad River Basin and nearby tributaries along the south shore of Lake Superior. Rainfall totals were 8–10 inches or more and most of the rain fell in an 8-hour period. A streamgage on the Bad River near Odanah, Wisconsin, rose from 300 cubic feet per second to a record peak streamflow of 40,000 cubic feet per second in only 15 hours. Following the storms and through September 2016, personnel from the U.S. Geological Survey and Bad River Tribe Natural Resources Department recovered and documented 108 high-water marks near the Bad River Reservation. Many of these high-water marks were used to create three flood-inundation maps for the Bad River, Beartrap Creek, and Denomie Creek for the Bad River Reservation in the vicinity of the community of Odanah.

  4. Hydrochemical evaluation of the influences of mining activities on river water chemistry in central northern Mongolia.

    Science.gov (United States)

    Batsaikhan, Bayartungalag; Kwon, Jang-Soon; Kim, Kyoung-Ho; Lee, Young-Joon; Lee, Jeong-Ho; Badarch, Mendbayar; Yun, Seong-Taek

    2017-01-01

    Although metallic mineral resources are most important in the economy of Mongolia, mining activities with improper management may result in the pollution of stream waters, posing a threat to aquatic ecosystems and humans. In this study, aiming to evaluate potential impacts of metallic mining activities on the quality of a transboundary river (Selenge) in central northern Mongolia, we performed hydrochemical investigations of rivers (Tuul, Khangal, Orkhon, Haraa, and Selenge). Hydrochemical analysis of river waters indicates that, while major dissolved ions originate from natural weathering (especially, dissolution of carbonate minerals) within watersheds, they are also influenced by mining activities. The water quality problem arising from very high turbidity is one of the major environmental concerns and is caused by suspended particles (mainly, sediment and soil particles) from diverse erosion processes, including erosion of river banks along the meandering river system, erosion of soils owing to overgrazing by livestock, and erosion by human activities, such as mining and agriculture. In particular, after passing through the Zaamar gold mining area, due to the disturbance of sediments and soils by placer gold mining, the Tuul River water becomes very turbid (up to 742 Nephelometric Turbidity Unit (NTU)). The Zaamar area is also the contamination source of the Tuul and Orkhon rivers by Al, Fe, and Mn, especially during the mining season. The hydrochemistry of the Khangal River is influenced by heavy metal (especially, Mn, Al, Cd, and As)-loaded mine drainage that originates from a huge tailing dam of the Erdenet porphyry Cu-Mo mine, as evidenced by δ(34)S values of dissolved sulfate (0.2 to 3.8 ‰). These two contaminated rivers (Tuul and Khangal) merge into the Orkhon River that flows to the Selenge River near the boundary between Mongolia and Russia and then eventually flows into Lake Baikal. Because water quality problems due to mining can be critical

  5. Flow status of three transboundary rivers in Northern Greece as a tool for hydro-diplomacy

    Science.gov (United States)

    Hatzigiannakis, Eyaggelos; Hatzispiroglou, Ioannis; Arampatzis, Georgios; Ilia, Andreas; Pantelakis, Dimitrios; Filintas, Agathos; Panagopoulos, Andreas

    2015-04-01

    The aim of this paper is to examine how the river flow monitoring consists a tool for hydro-diplomacy. Management of transboundary catchments and the demand of common water resources, often comprise the cause of conflicts and tension threatening the peaceful coexistence of nations. The Water Framework Directive 2000/60/EU sets a base for water management contributing to common approaches, common goals, common principles as well as providing new definitions and measures for Europe's water resources. In northern Greece the main renewable resources are "imported" (over 25% of its water reserves) and for this reason the implementation of continuous flow measurements throughout the year is necessary, even though difficult to achieve. This paper focuses on the three largest transboundary rivers in Northern Greece. Axios and Strymonas river flow across the region of Central Macedonia in Northern Greece. Axios flows from FYROM to Greece, and Strymonas from Bulgaria to Greece. Nestos river flows from Bulgaria to Greece. The Greek part is in the region of Eastern Macedonia and Thrace in Northern Greece. Significant productive agricultural areas around these rivers are irrigated from them so they are very important for the local society. Measurements of the river flow velocity and the flow depth have been made at bridges. The frequency of the measurements is roughly monthly, because it is expected a significant change in the depth flow and discharge. A series of continuously flow measure-ments were performed during 2013 and 2014 using flowmeters (Valeport and OTT type). The cross-section characteristics, the river flow velocity of segments and the mean water flow velocity and discharge total profile were measured and calculated re-spectively. Measurements are conducted in the framework of the national water resources monitoring network, which is realised in compliance to the Water Framework Directive under the supervision and coordination of the Hellenic Ministry for the

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

    Institute of Scientific and Technical Information of China (English)

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

    2007-01-01

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

  7. Spatial Variability of Escherichia coli in Rivers of Northern Coastal Ecuador

    Directory of Open Access Journals (Sweden)

    Gouthami Rao

    2015-02-01

    Full Text Available The use of contaminated surface water continues to be a pressing issue in areas of the world where people lack improved drinking water sources. In northern coastal Ecuador, many communities rely on untreated surface water as their primary source of drinking water. We undertook a study to explore how microscale river hydrodynamics affect microbial water quality at community water collection locations at three rivers with varying stream velocity and turbidity profiles. To examine how the distance from river shore and physiochemical water quality variables affect microbial contamination levels in the rivers; we collected a total of 355 water samples within six villages on three rivers; and tested for Escherichia coli concentrations using the IDEXX Quanti-tray method. We found that log10 E. coli concentrations decreased with increasing distance from shore (β = −0.017; p = 0.003. Water in the main channel had E. coli concentrations on average 0.12 log10 lower than within eddies along the river shore and 0.27 log10 lower between the sample closest to shore and any sample >6 m from the shore. Higher E. coli concentrations were also significantly associated with increased turbidity (β = 0.003; p < 0.0001 and decreased dissolved oxygen levels (β = −0.310; p < 0.0001. The results of this study can help inform community members about the safest locations to collect drinking water and also provide information on watershed scale transport of microbial contaminants between villages.

  8. Spatial Variability of Escherichia coli in Rivers of Northern Coastal Ecuador.

    Science.gov (United States)

    Rao, Gouthami; Eisenberg, Joseph N S; Kleinbaum, David G; Cevallos, William; Trueba, Gabriel; Levy, Karen

    2015-02-13

    The use of contaminated surface water continues to be a pressing issue in areas of the world where people lack improved drinking water sources. In northern coastal Ecuador, many communities rely on untreated surface water as their primary source of drinking water. We undertook a study to explore how microscale river hydrodynamics affect microbial water quality at community water collection locations at three rivers with varying stream velocity and turbidity profiles. To examine how the distance from river shore and physiochemical water quality variables affect microbial contamination levels in the rivers; we collected a total of 355 water samples within six villages on three rivers; and tested for Escherichia coli concentrations using the IDEXX Quanti-tray method. We found that log10E. coli concentrations decreased with increasing distance from shore (β = -0.017; p = 0.003). Water in the main channel had E. coli concentrations on average 0.12 log10 lower than within eddies along the river shore and 0.27 log10 lower between the sample closest to shore and any sample >6 m from the shore. Higher E. coli concentrations were also significantly associated with increased turbidity (β = 0.003; p < 0.0001) and decreased dissolved oxygen levels (β = -0.310; p < 0.0001). The results of this study can help inform community members about the safest locations to collect drinking water and also provide information on watershed scale transport of microbial contaminants between villages.

  9. Ice jam-caused fluvial gullies and scour holes on northern river flood plains

    Science.gov (United States)

    Smith, Derald G.; Pearce, Cheryl M.

    2002-01-01

    Two anomalous fluvial landforms, gullies and scour holes, eroded into flood plains bordering meandering and braiding river channels have not been previously reported. We observed these features along the Milk River in southern Alberta, Canada, and northern Montana, USA, which has a history of frequent (50% probability of recurrence) and high-magnitude (12% probability of recurrence greater than bankfull) ice jam floods. Gullies have palmate and narrow linear shapes with open-ends downvalley and measure up to 208 m long×139 m wide×3.5 m deep (below bankfull). Channel ice jams reroute river water across meander lobes and cause headward gully erosion where flow returns to the main channel. Erosion of the most recent gully was observed during the record 1996 ice breakup flood and ice jams. Scour holes (bowl-shaped, closed depressions), eroded by water vortices beneath and between grounded ice jam blocks, measure up to 91 m long×22 m wide×4.5 m deep. Ice jam-caused gullies may be precursors to the formation of U-shaped oxbow lakes and multiple channels, common in many northern rivers.

  10. Fate of the Evros River suspended particulate matter in the northern Aegean Sea

    Science.gov (United States)

    Kanellopoulos, Theodore D.; Angelidis, Michael O.; Georgopoulos, Dimitrios; Karageorgis, Aristomenis P.

    2009-06-01

    Evros River is the most important river flowing into the North Aegean Sea (eastern Mediterranean) in terms of freshwater discharge, and the second largest one of Eastern Europe after the Danube River. Salinity and temperature measurements, together with suspended particulate matter concentrations were obtained in various depths at 14 stations in the adjacent Alexandroupolis Gulf during four seasons (June 1998, September 1998, February 1999 and March 2000) in order to investigate the particle dynamics and distributions in the northern Aegean Sea. Analysis of the collected data, together with particle observations under the scanning electron microscope and study of satellite images showed that, under certain circumstances driven by the hydrological and wind regime of the area, the Evros River particulate matter, with the associated pollutants, can be transferred far away from the estuary and implicitly comprise a hazardous factor for the environmental status of the northern Aegean Sea. This fact, combined with the future construction of the Burgas-Alexandroupolis pipeline, may cause a negative impact on the studied natural ecosystem.

  11. Gravel extraction and planform change in a wandering gravel-bed river: The River Wear, Northern England

    Science.gov (United States)

    Wishart, Duncan; Warburton, Jeff; Bracken, Louise

    2008-02-01

    Within-channel alluvial gravel extraction is one of the most important forms of anthropogenically induced morphological change in river channels. In British rivers commercial gravel extraction was widespread between the 1930s and 1960s, and limited gravel extraction operations to reduce flood risk or maintain navigation continue to the present day. Despite this, gravel extraction has received little attention in UK river studies. This paper examines the significance of within-channel gravel extraction, during the period 1945-1960, on the planform of the River Wear in northern England. The study focuses on two 3 km piedmont reaches at Wolsingham and Harperley Park, located at the margin of the upland zone. Examination of detailed archival accounts of the gravel extraction operations, supplemented by the analysis of aerial photographs has enabled the impact of gravel extraction on the channel of the River Wear to be determined. Sediment budget calculations suggest large sediment deficits in both study reaches, however, assessing potential impacts simply in terms of a sediment deficit may be misleading as channel adjustments depend on local factors and a detailed consideration of the reach-scale sediment budget. Differences in the nature of channel adjustments of both reaches were found to be primarily a function of the method of gravel extraction employed. Overall patterns of channel change along the extraction reaches, over the past 150 years, were similar to reaches where gravel extraction was not practiced. This highlights the difficulty of trying to establish the significance of different processes where both local (gravel extraction) and catchment-scale factors (climate and land use) are operating.

  12. Sinuosity change of the Po River near Cremona (Northern Italy) - a result of neotectonic activity?

    Science.gov (United States)

    Petrovszki, Judit; Timár, Gábor

    2010-05-01

    In the map sheets of the Second Military Survey of the Habsburg Empire, Lombardia, Parma, Modena and Venice also can be seen (Timár et al., 2006). This area was surveyed between 1818 and 1829. In these map sheets, we can also follow the river Po from Vaccarizza to the delta. This river reach is about 350 km long. This river reach was digitized and sinuosity values were calculated with different window sizes, and displayed in a spectrum-like diagram (sinuosity spectra; after van Balen et al., 2008). At Cremona, a significante sinuosity change were identified. The sinuosity increasing, and we have high sinuosity values. In the summarizing geological map of Italy (Compagnoni and Calluzzo, 2004), at this place, a tectonic line was identified. So probably this fault line invokes the sinuosity change on the river. The vertical movements indicated on the maps are just the opposite like they would be according to the flume experiments of Ouchi (1985). In the case of the Po River at Cremona, the decrease of the channel slope results higher sinuosity. The reason is that the rate of the slope and water discharge is higher than it is required by the self-organized meandering and the river parameters fell to the range of the unorganized meandering (cf. Timár, 2003). Another possible explanation could be that the northern tributary, the Adda River has significant sediment load that lowers the sinuosity of the trunk river at the confluence. Compagnoni, B., Galluzzo, F. (eds., 2004): Geological Map of Italy. Agenzia per la Protezione dell'Ambiente per I Servizi Tecnici - Dipartimento Difesa del Suolo, Servizio Geologico d'Italia, Rome-Florence-Genoa. Map, scale=1:1250000, especially printed for the 32nd International Geological Congress. Ouchi, S. (1985): Response of alluvial rivers to slow active tectonic movement. Geol. Soc. Am. Bull. 96: 504-515. Timár, G. (2003): Controls on channel sinuosity changes: a case study of the Tisza River, the Great Hungarian Plain. Quaternary

  13. Monitoring of Streambank Stabilization and River Restoration Structures on Ice-Affected Rivers in Northern Vermont

    Science.gov (United States)

    2009-08-01

    Note aggradation on the left bank (looking downstream) has nearly buried the vane...is still aggrading in the vicinity of the upstream cross vane, as the rocks forming the left hand vane (facing downstream) are now nearly buried in...gravel (Figure 24). Flow Aggrading left bank area & nearly buried vane Figure 24. Mad River near Warren, upper cross vane viewed from

  14. Predictability of Western Himalayan river flow: melt seasonal inflow into Bhakra Reservoir in northern India

    Directory of Open Access Journals (Sweden)

    I. Pal

    2013-06-01

    Full Text Available Snowmelt-dominated streamflow of the Western Himalayan rivers is an important water resource during the dry pre-monsoon spring months to meet the irrigation and hydropower needs in northern India. Here we study the seasonal prediction of melt-dominated total inflow into the Bhakra Dam in northern India based on statistical relationships with meteorological variables during the preceding winter. Total inflow into the Bhakra Dam includes the Satluj River flow together with a flow diversion from its tributary, the Beas River. Both are tributaries of the Indus River that originate from the Western Himalayas, which is an under-studied region. Average measured winter snow volume at the upper-elevation stations and corresponding lower-elevation rainfall and temperature of the Satluj River basin were considered as empirical predictors. Akaike information criteria (AIC and Bayesian information criteria (BIC were used to select the best subset of inputs from all the possible combinations of predictors for a multiple linear regression framework. To test for potential issues arising due to multicollinearity of the predictor variables, cross-validated prediction skills of the best subset were also compared with the prediction skills of principal component regression (PCR and partial least squares regression (PLSR techniques, which yielded broadly similar results. As a whole, the forecasts of the melt season at the end of winter and as the melt season commences were shown to have potential skill for guiding the development of stochastic optimization models to manage the trade-off between irrigation and hydropower releases versus flood control during the annual fill cycle of the Bhakra Reservoir, a major energy and irrigation source in the region.

  15. Predictability of Western Himalayan river flow: melt seasonal inflow into Bhakra Reservoir in northern India

    Science.gov (United States)

    Pal, I.; Lall, U.; Robertson, A. W.; Cane, M. A.; Bansal, R.

    2013-06-01

    Snowmelt-dominated streamflow of the Western Himalayan rivers is an important water resource during the dry pre-monsoon spring months to meet the irrigation and hydropower needs in northern India. Here we study the seasonal prediction of melt-dominated total inflow into the Bhakra Dam in northern India based on statistical relationships with meteorological variables during the preceding winter. Total inflow into the Bhakra Dam includes the Satluj River flow together with a flow diversion from its tributary, the Beas River. Both are tributaries of the Indus River that originate from the Western Himalayas, which is an under-studied region. Average measured winter snow volume at the upper-elevation stations and corresponding lower-elevation rainfall and temperature of the Satluj River basin were considered as empirical predictors. Akaike information criteria (AIC) and Bayesian information criteria (BIC) were used to select the best subset of inputs from all the possible combinations of predictors for a multiple linear regression framework. To test for potential issues arising due to multicollinearity of the predictor variables, cross-validated prediction skills of the best subset were also compared with the prediction skills of principal component regression (PCR) and partial least squares regression (PLSR) techniques, which yielded broadly similar results. As a whole, the forecasts of the melt season at the end of winter and as the melt season commences were shown to have potential skill for guiding the development of stochastic optimization models to manage the trade-off between irrigation and hydropower releases versus flood control during the annual fill cycle of the Bhakra Reservoir, a major energy and irrigation source in the region.

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

    Science.gov (United States)

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

    2009-08-15

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-08-15

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

  18. Mercury poisoning in a free-living northern river otter (Lontra canadensis).

    Science.gov (United States)

    Sleeman, Jonathan M; Cristol, Daniel A; White, Ariel E; Evers, David C; Gerhold, R W; Keel, Michael K

    2010-07-01

    A moribund 5-year-old female northern river otter (Lontra canadensis) was found on the bank of a river known to be extensively contaminated with mercury. It exhibited severe ataxia and scleral injection, made no attempt to flee, and died shortly thereafter of drowning. Tissue mercury levels were among the highest ever reported for a free-living terrestrial mammal: kidney, 353 microg/g; liver, 221 microg/g; muscle, 121 microg/g; brain (three replicates from cerebellum), 142, 151, 151 microg/g (all dry weights); and fur, 183 ug/g (fresh weight). Histopathologic findings including severe, diffuse, chronic glomerulosclerosis and moderate interstitial fibrosis were the presumptive cause of clinical signs and death. This is one of a few reports to document the death of a free-living mammal from presumed mercury poisoning.

  19. Decreased runoff response to precipitation, Little Missouri River Basin, northern Great Plains, USA

    Science.gov (United States)

    Griffin, Eleanor R.; Friedman, Jonathan M.

    2017-01-01

    High variability in precipitation and streamflow in the semiarid northern Great Plains causes large uncertainty in water availability. This uncertainty is compounded by potential effects of future climate change. We examined historical variability in annual and growing season precipitation, temperature, and streamflow within the Little Missouri River Basin and identified differences in the runoff response to precipitation for the period 1976-2012 compared to 1939-1975 (n = 37 years in both cases). Computed mean values for the second half of the record showed little change (1°C increases in January through March, are the dominant driver of the observed decrease in runoff response to precipitation in the Little Missouri River Basin.

  20. Dissolved organic matter as an indicator of changing watersheds in northern rivers

    Science.gov (United States)

    Aiken, G.; Spencer, R.; Striegl, R.; Raymond, P. A.

    2009-12-01

    Responses of frozen soils to climate warming is of particular significance for understanding long term climate effects on global carbon cycling and carbon export by high latitude rivers. Monitoring climate effects on carbon cycling, however, is complicated by logistical and analytical challenges associated with spatially heterogeneous processes occurring over large watershed areas. Dissolved organic matter (DOM) chemistry and flux are potentially useful, albeit underutilized, indicators of watershed change. The chemical characteristics of DOM in rivers and lakes are the net result of source materials, watershed geochemistry, oxidative processes and hydrology within these systems and upstream basins. As the large reserves of organic carbon associated with frozen soils in the northern permafrost regions are mobilized by changes in soil microbial processes and hydrologic flow paths, it is anticipated that both the composition and flux of DOM will change in waters draining these soils. Here we present results that demonstrate the utility of assessing DOM composition and flux for gaining insight into processes controlling DOM in the Yukon River and its tributaries. The Yukon River Basin is a large, diverse ecosystem in northwestern Canada and central Alaska that is experiencing increasing temperatures, partial thawing of permafrost, drying of upland soils and changing wetland environments. In our analyses of this system, we have used DOM data in two ways to define carbon cycling and transport processes throughout the basin. First, analyses of chemical composition using DOM optical properties (UV-Vis absorbance, fluorescence), isotopic composition (14C), lignin phenol content and chromatographic fractionation have provided critical information related to spatial and temporal variations in DOM exported from watersheds throughout the basin that are driven by different processes. For instance, characterization data indicate that DOM currently exported from watersheds

  1. Spatio-temporal variations in age structures of a partially re-established population of northern river otters (Lontra canadensis)

    Science.gov (United States)

    Barrett, Dominic A.; Leslie,, David M.

    2012-01-01

    Examination of age structures and sex ratios is useful in the management of northern river otters (Lontra canadensis) and other furbearers. Reintroductions and subsequent recolonizations of river otters have been well documented, but changes in demographics between expanding and established populations have not been observed. As a result of reintroduction efforts, immigration from Arkansas and northeastern Texas, and other efforts, river otters have become partially reestablished throughout eastern and central Oklahoma. Our objective was to examine age structures of river otters in Oklahoma and identify trends that relate to space (watersheds, county) and time (USDA Animal and Plant Health Inspection Service county trapping records). We predicted that river otters in western areas of the state were younger than river otters occurring farther east. From 2005–2007, we obtained salvaged river otter carcasses from federal and state agencies, and we live-captured other river otters using leg hold traps. Seventy-two river otters were sampled. Overall, sex ratios were skewed toward females (1F∶0.8M), but they did not differ among spatiotemporal scales examined. Teeth were removed from salvaged and live-captured river otters (n  =  63) for aging. One-year old river otters represented the largest age class (30.2%). Proportion of juveniles (populations of river otters in Oklahoma contained younger ages than more established eastern populations.

  2. Application of a technique for scenario prediction of climate change impact on the water balance components of northern river basins

    Directory of Open Access Journals (Sweden)

    Gusev Yeugeniy M.

    2014-09-01

    Full Text Available The scenario forecasting technique for assessing changes of water balance components of the northern river basins due to possible climate change was developed. Three IPCC global emission scenarios corresponding to different possible scenarios for economic, technological, political and demographic development of the human civilization in the 21st century were chosen for generating climate change projections by an ensemble of 16 General Circulation Models with a high spatial resolution. The projections representing increments of monthly values of meteorological characteristics were used for creating 3-hour meteorological time series up to 2063 for the Northern Dvina River basin, which belongs to the pan-Arctic basin and locates at the north of the European part of Russia. The obtained time series were applied as forcing data to drive the land surface model SWAP to simulate possible changes in the water balance components due to different scenarios of climate change for the Northern Dvina River basin

  3. Source identification of fine-grained suspended sediment in the Kharaa River basin, northern Mongolia

    Energy Technology Data Exchange (ETDEWEB)

    Theuring, Philipp [Department of Aquatic Ecosystem Analysis and Management — ASAM, Helmholtz Centre for Environmental Research — UFZ, Brückstrasse 3a, D-39114 Magdeburg (Germany); Collins, Adrian L. [Sustainable Soils and Grassland Systems Department, Rothamsted Research, North Wyke, Okehampton, Devon EX20 2SB (United Kingdom); Rode, Michael [Department of Aquatic Ecosystem Analysis and Management — ASAM, Helmholtz Centre for Environmental Research — UFZ, Brückstrasse 3a, D-39114 Magdeburg (Germany)

    2015-09-01

    Fine sediment inputs into river systems can be a major source of nutrients and heavy metals and have a strong impact on water quality and ecosystem functions of rivers and lakes, including those in semiarid regions. However, little is known to date about the spatial distribution of sediment sources in most large scale river basins in Central Asia. Accordingly, a sediment source fingerprinting technique was used to assess the spatial sources of fine-grained (< 10 μm) sediment in the 15 000 km{sup 2} Kharaa River basin in northern Mongolia. Variation in geochemical composition (e.g. in Ti, Sn, Mo, Mn, As, Sr, B, U, Ca and Sb) was used for sediment source discrimination with geochemical composite fingerprints based on Genetic Algorithm (GA)-driven Discriminant Function Analysis, the Kruskal–Wallis H-test and Principal Component Analysis. All composite fingerprints yielded a satisfactory GOF (> 0.97) and were subsequently used for numerical mass balance modelling with uncertainty analysis. The contributions of the individual sub-catchment spatial sediment sources varied from 6.4% (the headwater sub-catchment of Sugnugur Gol) to 36.2% (the Kharaa II sub-catchment in the middle reaches of the study basin), generally showing higher contributions from the sub-catchments in the middle, rather than the upstream, portions of the study area. The importance of river bank erosion is shown to increase from upstream to midstream tributaries. The source tracing procedure provides results in reasonable accordance with previous findings in the study region and demonstrates the applicability and associated uncertainties of the approach for fine-grained sediment source investigation in large scale semi-arid catchments. - Highlights: • Applied statistical approach for selecting composite fingerprints in Mongolia. • Geochemical fingerprinting for the definition of source areas in semiarid catchment. • Test of applicability of sediment sourcing in large scale semi-arid catchments

  4. You Winsome, you lose some: Home and hospitality in the Northern Rivers

    Directory of Open Access Journals (Sweden)

    Grayson Cooke

    2015-09-01

    Full Text Available The Home Project was a three-year collaborative research project, established through a partnership between Northern Rivers Performing Arts (NORPA and the School of Arts and Social Sciences (SASS at Southern Cross University (SCU. The Home Project’s objective was to raise awareness of homelessness in the Northern Rivers region of New South Wales through creative arts practice and community engagement activities. The broad project aims were to explore questions of home, homelessness and belonging in Northern Rivers’ communities; to address the experiences of individuals affected by homelessness; and, where appropriate, to provide avenues for public dissemination of the stories of individuals who are or have been without a home. This article discusses the activities undertaken in each year of the project, providing a case study of a community engaged research project involving collaboration between university staff and students, a performing arts organisation and a community service provider. We analyse the development of the project over the three years and discuss the emergence of the theme of ‘hospitality’, which came to frame the project in its latter stages as we focused our activities at the Winsome Hotel, a Heritage listed and iconic Australian hotel that now offers low-cost daily lunches and a short-term accommodation service for marginalised men. This focus on the Winsome Hotel and hospitality gave us, as researchers, a new way to think about the provision of services to people without a home. Keywords: Homelessness, hospitality, creative arts practice, community engagement, NORPA, Southern Cross University

  5. Water contamination from oil extraction activities in Northern Peruvian Amazonian rivers.

    Science.gov (United States)

    Yusta-García, Raúl; Orta-Martínez, Martí; Mayor, Pedro; González-Crespo, Carlos; Rosell-Melé, Antoni

    2017-06-01

    Oil extraction activities in the Northern Peruvian Amazon have generated a long-standing socio-environmental conflict between oil companies, governmental authorities and indigenous communities, partly derived from the discharge of produced waters containing high amounts of heavy metals and hydrocarbons. To assess the impact of produced waters discharges we conducted a meta-analysis of 2951 river water and 652 produced water chemical analyses from governmental institutions and oil companies reports, collected in four Amazonian river basins (Marañon, Tigre, Corrientes and Pastaza) and their tributaries. Produced water discharges had much higher concentrations of chloride, barium, cadmium and lead than are typically found in fresh waters, resulting in the widespread contamination of the natural water courses. A significant number of water samples had levels of cadmium, barium, hexavalent chromium and lead that did not meet Peruvian and international water standards. Our study shows that spillage of produced water in Peruvian Amazon rivers placed at risk indigenous population and wildlife during several decades. Furthermore, the impact of such activities in the headwaters of the Amazon extended well beyond the boundaries of oil concessions and national borders, which should be taken into consideration when evaluating large scale anthropogenic impacts in the Amazon. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. [Methanotrophic bacteria in cold seeps of the floodplains of northern rivers].

    Science.gov (United States)

    Belova, S É; Oshkin, I Iu; Glagolev, M V; Lapshina, E D; Maksiutov, Sh Sh; Dedysh, S N

    2013-01-01

    Small mud volcanoes (cold seeps), which are common in the floodplains of northern rivers, are a potentially important, although poorly studied sources of atmospheric methane. Field research on the cold seeps of the Mukhrina River (Khanty-Mansiysk Autonomous okrug, Russia) revealed methane fluxes from these structures to be orders of magnitude higher than from equivalent areas of the mid-taiga bogs. Microbial communities developing around the seeps were formed under conditions of high methane concentrations, low temperatures (3-5 degrees C), and near-neutral pH. Molecular identification of methane-oxidizing bacteria from this community by analysis of the pmoA gene encoding particulate methane monooxygenase revealed both type I and type II methanotrophs (classes Gammaproteobacteria and Alphaproteobacteria, respectively), with predomination of type I methanotrophs. Among the latter, microorganisms related to Methylobacterpsychrophilus and Methylobacter tundripaludum, Crenothrix polyspora (a stagnant water dweller), and a number of methanotrophs belonging to unknown taxa were detected. Growth characteristics of two isolates were determined. Methylobactersp. CMS7 exhibited active growth at 4-10 degrees C, while Methylocystis sp. SB12 grew better at 20 degrees C. Experimental results confirmed the major role ofmethanotrophic gammaproteobacteria in controlling the methane emission from cold river seeps.

  7. Dominant Factors Controlling the Hydrometeorology of Northern California: Landfalling Atmospheric Rivers and Sierra Barrier Jets

    Science.gov (United States)

    Neiman, P. J.; Ralph, F. M.; Hughes, M.; Sukovich, E.; Kingsmill, D. E.; Zamora, R. J.; Moore, B. J.

    2014-12-01

    Northern California's Sierra Nevada and Shasta-Trinity mountains are key to the state's water supply and can contribute to major floods in the Central Valley (CV). NOAA's Hydrometeorology Testbed (HMT) program and the CalWater experiment have discovered much about how landfalling atmospheric rivers (AR) and Sierra Barrier Jets (SBJ) modulate orographic precipitation in that region. This presentation provides a review of recent findings, both from case-study and compositing perspectives. Wind-profiler and global-positioning-system (GPS) observations are used with soil moisture probes, stream gauges, and a regional reanalysis dataset. Key results include: Inland-directed ARs override a ~1-km-deep, Sierra-parallel SBJ located above the CV and the western slope of the Sierra. Above the developing SBJ, strengthening southwesterly flow marks the AR. The moistening SBJ reaches maximum intensity during the strongest AR flow aloft, at which time the core of the AR-parallel vapor transport slopes over the SBJ and intersects the Sierra. The SBJ then weakens with the initial cold-frontal passage aloft. A statistical analysis of orographic forcing reveals that both the AR and SBJ are crucial in determining the distribution of precipitation in the northern Sierra and Shasta-Trinity regions due to orographic precipitation enhancement. An open question remains regarding the transport of water vapor near the northern end of the CV. Namely, a portion of the AR-modulated SBJ flow may be transported through a prominent gap in the terrain between Mt. Lassen and Mt. Shasta, near the town of Burney. Recent analyses indicate that this gap allows AR water vapor to penetrate into the western interior (e.g., to Idaho) and thus contribute to heavy precipitation events far inland. The CalWater-2 program of field campaigns has identified diagnosis of the transport through this gap and its impact on northern California precipitation as a priority for future data collection and analysis.

  8. Developing an environmental water quality monitoring program for Haraz River in Northern Iran.

    Science.gov (United States)

    Tavakol, Mitra; Arjmandi, Reza; Shayeghi, Mansoureh; Monavari, Seyed Masoud; Karbassi, Abdolreza

    2017-08-01

    Water quality management plans are an indispensable strategy for conservation and utilization of water resources in a sustainable manner. One common industrial use of water is aquaculture. The present study is an attempt to use statistical analyses in order to prepare an environmental water quality monitoring program for Haraz River, in Northern Iran. For this purpose, the analysis of a total number of 18 physicochemical parameters was performed at 15 stations during a 1-year sampling period. According to the results of the multivariate statistical methods, the optimal monitoring would be possible by only 3 stations and 12 parameters, including NH3, EC, BOD, TSS, DO, PO4, NO3, TDS, temperature, turbidity, coliform, and discharge. In other words, newly designed network, with a total number of 36 measurements (3 stations × 12 parameters = 36 parameters), could achieve exactly the same performance as the former network, designed based on 234 measurements (13 stations × 18 parameters = 234 parameters). Based on the results of cluster, principal component, and factor analyses, the stations were divided into three groups of high pollution (HP), medium pollution (MP), and low pollution (LP). By clustering the stations, it would be possible to track the water quality of Haraz River, only by one station at each cluster, which facilitates rapid assessment of the water quality in the river basin. Emphasizing on three main axes of monitoring program, including measurement parameters, sampling frequency, and spatial pattern of sampling points, the water quality monitoring program was optimized for the river basin based on natural conditions of the study area, monitoring objectives, and required financial resources (a total annual cost of about US $2625, excluding the overhead costs).

  9. Spatial Patterns of Suspended Sediment Yield in the Upper Indus River Basin, Northern Pakistan

    Science.gov (United States)

    Ali, K.; de Boer, D. H.; Martz, L. W.

    2004-05-01

    The Indus River is one of the world`s largest rivers in term of water discharge and sediment loads, and the backbone of Pakistan`s economy for agriculture and hydropower. Much of its flow originates in the mountains of the Himalayas, Karakoram and Hindu Kush. The suspended sediment load, which constitutes the main portion of the total load in mountain rivers, creates major water resources management problems such as siltation of reservoirs, damage to turbines, and a reduction in water quality. An understanding of the spatial pattern of suspended sediment yield in the upper Indus River basin is, therefore, essential for effective water resources development in northern Pakistan. Discharge and suspended sediment concentration records are available for 17 active and discontinued hydrological stations (with drainage areas ranging from 600 to 166,000 km2) operated by the Pakistan Water and Power Development Authority. The objective of this study is to delineate the spatial pattern of suspended sediment yield in the basin by analyzing the available hydrological database. Sediment yields have been calculated by constructing sediment rating curves. Physiographic characteristics, hydrologic regimes and climatic patterns of the basin have also been investigated. The results show that the upper Indus River basin can be subdivided into three regions based on suspended sediments yield. This division reflects the contrasting hydrological regimes of the basin. Region 1 comprises the high elevation, glacierized areas of the Karakoram Mountains in the northernmost part of the basin. This region extends downstream to Partab Bridge on the Indus River, and excludes areas around Nanga Parbat, which acts as a barrier to the monsoon. The sediments are mainly derived from the Shyok, Shigar, Hunza and Gilgit sub-basins during the period of increasing summer runoff in June. This runoff is caused by the melt of glaciers and permanent snow pack, and peaks in July and August, when almost the

  10. Range maps of terrestrial species in the interior Columbia River basin and northern portions of the Klamath and Great Basins.

    Science.gov (United States)

    Bruce G. Marcot; Barbara C. Wales; Rick. Demmer

    2003-01-01

    Current range distribution maps are presented for 14 invertebrate, 26 amphibian, 26 reptile, 339 bird, and 125 mammal species and selected subspecies (530 total taxa) of the interior Columbia River basin and northern portions of the Klamath and Great Basins in the United States. Also presented are maps of historical ranges of 3 bird and 10 mammal species, and 6 maps of...

  11. Complete mitogenomic sequence of the Critically Endangered Northern River Shark Glyphis garricki (Carcharhiniformes: Carcharhinidae).

    Science.gov (United States)

    Feutry, Pierre; Grewe, Peter M; Kyne, Peter M; Chen, Xiao

    2015-01-01

    In this study we describe the first complete mitochondrial sequence for the Critically Endangered Northern River shark Glyphis garricki. The complete mitochondrial sequence is 16,702 bp in length, contains 37 genes and one control region with the typical gene order and transcriptional direction of vertebrate mitogenomes. The overall base composition is 31.5% A, 26.3% C, 12.9% G and 29.3% T. The length of 22 tRNA genes ranged from 68 (tRNA-Ser2 and tRNA-Cys) to 75 (tRNA-Leu1) bp. The control region of G. garricki was 1067 bp in length with high A+T (67.9%) and poor G (12.6%) content. The mitogenomic characters (base composition, codon usage and gene length) of G. garricki were very similar to Glyphis glyphis.

  12. A multitrophic approach to monitoring the effects of metal mining in otherwise pristine and ecologically sensitive rivers in northern Canada.

    Science.gov (United States)

    Spencer, Paula; Bowman, Michelle F; Dubé, Monique G

    2008-07-01

    It is not known if current chemical and biological monitoring methods are appropriate for assessing the impacts of growing industrial development on ecologically sensitive northern waters. We used a multitrophic level approach to evaluate current monitoring methods and to determine whether metal-mining activities had affected 2 otherwise pristine rivers that flow into the South Nahanni River, Northwest Territories, a World Heritage Site. We compared upstream reference conditions in the rivers to sites downstream and further downstream of mines. The endpoints we evaluated included concentrations of metals in river water, sediments, and liver and flesh of slimy sculpin (Cottus cognatus); benthic algal and macroinvertebrate abundance, richness, diversity, and community composition; and various slimy sculpin measures, our sentinel forage fish species. Elevated concentrations of copper and iron in liver tissue of sculpin from the Flat River were associated with high concentrations of mine-derived iron in river water and copper in sediments that were above national guidelines. In addition, sites downstream of the mine on the Flat River had increased algal abundances and altered benthic macroinvertebrate communities, whereas the sites downstream of the mine on Prairie Creek had increased benthic macroinvertebrate taxa richness and improved sculpin condition. Biological differences in both rivers were consistent with mild enrichment of the rivers downstream of current and historical mining activity. We recommend that monitoring in these northern rivers focus on indicators in epilithon and benthic macroinvertebrate communities due to their responsiveness and as alternatives to lethal fish sampling in habitats with low fish abundance. We also recommend monitoring of metal burdens in periphyton and benthic invertebrates for assessment of exposure to mine effluent and causal association. Although the effects of mining activities on riverine biota currently are limited, our

  13. Potential risks of metal toxicity in contaminated sediments of Deule river in Northern France

    Energy Technology Data Exchange (ETDEWEB)

    Lourino-Cabana, Beatriz; Lesven, Ludovic; Charriau, Adeline [Equipe de Chimie Analytique et Marine, Universite de Lille 1, FRE CNRS Geosystemes 3298, Bat. C8, 59655 Villeneuve d' Ascq (France); Billon, Gabriel, E-mail: gabriel.billon@univ-lille1.fr [Equipe de Chimie Analytique et Marine, Universite de Lille 1, FRE CNRS Geosystemes 3298, Bat. C8, 59655 Villeneuve d' Ascq (France); Ouddane, Baghdad [Equipe de Chimie Analytique et Marine, Universite de Lille 1, FRE CNRS Geosystemes 3298, Bat. C8, 59655 Villeneuve d' Ascq (France); Boughriet, Abdel [Universite Lille Nord de France, Rue de l' Universite, P.O. Box 819, 62408 Bethune (France)

    2011-02-28

    Research highlights: {yields} A historical environmental pollution is evidenced with reference to background levels. {yields} Sedimentary trace metals partitioning is examined under undisturbed conditions. {yields} Anoxia and diagenetic processes induce geochemical and mineralogical variabilities. {yields} Do metals present in particles and pore waters exhibit a potential toxicity risk? {yields} Behaviour of binding fractions contributes to trace metals scavenging. - Abstract: The aim of this paper was to evaluate the potential sediment cumulative damage and toxicity due to metal contamination in a polluted zone of Deule river (in northern France) from nearby two smelters. Metal-enrichment factors and geoaccumulation indices measured with sediment depth revealed that - compared to background levels either in local reference soils or in world rivers sediments/suspended particulate matter - Cd contributed to the highest pollution levels, followed by Zn, Pb and to a much lesser extent Cu and Ni. A comparison of the vertical distribution of AVS (acid volatile sulfides), SEM (simultaneously extracted metals), TMC (total metal concentrations), TOC (total organic carbon) and interstitial water-metal concentrations in the sediment allowed us to highlight the extent of toxicity caused by Cd, Pb, Zn, Ni and Cu and to raise the possibility of their association with certain geochemical phases. To assess the actual environmental impacts of these metals in Deule river, numerical sediment quality guidelines were further used in the present work. Sedimentary Pb, Zn, and Cd contents largely exceeded PEC (probable effect concentration) values reported as consensus-based sediment quality guidelines for freshwater ecosystems. As for risks of toxicity from pore waters, metal concentrations reached their maxima at the surficial layers of the sediment (1-3 cm) and IWCTU (Interstitial Water Criteria Toxicity Unit) observed for Pb and to a lesser extent Cd, violated the corresponding water

  14. Individual growth and reproductive behavior in a newly established population of northern snakehead (Channa argus), Potomac River, USA

    Science.gov (United States)

    Landis, Andrew M. Gascho; Lapointe, Nicolas W. R.; Angermeier, Paul L.

    2010-01-01

    Northern snakehead (Channa argus) were first found in the Potomac River in 2004. In 2007, we documented feeding and reproductive behavior to better understand how this species is performing in this novel environment. From April to October, we used electrofishing surveys to collect data on growth, condition, and gonad weight of adult fish. Growth rates of young were measured on a daily basis for several weeks. Mean length-at-age for Potomac River northern snakehead was lower than for fish from China, Russia, and Uzbekistan. Fish condition was above average during spring and fall, but below average in summer. Below-average condition corresponded to periods of high spawning activity. Gonadosomatic index indicated that females began spawning at the end of April and continued through August. Peak spawning occurred at the beginning of June when average temperatures reached 26°C. Larval fish growth rate, after the transition to exogenous feeding, was 2.3 (SD ± 0.7) mm (total length, TL) per day. Although Potomac River northern snakehead exhibited lower overall growth rates when compared to other populations, these fish demonstrated plasticity in timing of reproduction and rapid larval growth rates. Such life history characteristics likely contribute to the success of northern snakehead in its new environment and limit managers’ options for significant control of its invasion.

  15. Year-class formation of upper St. Lawrence River northern pike

    Science.gov (United States)

    Smith, B.M.; Farrell, J.M.; Underwood, H.B.; Smith, S.J.

    2007-01-01

    Variables associated with year-class formation in upper St. Lawrence River northern pike Esox lucius were examined to explore population trends. A partial least-squares (PLS) regression model (PLS 1) was used to relate a year-class strength index (YCSI; 1974-1997) to explanatory variables associated with spawning and nursery areas (seasonal water level and temperature and their variability, number of ice days, and last day of ice presence). A second model (PLS 2) incorporated four additional ecological variables: potential predators (abundance of double-crested cormorants Phalacrocorax auritus and yellow perch Perca flavescens), female northern pike biomass (as a measure of stock-recruitment effects), and total phosphorus (productivity). Trends in adult northern pike catch revealed a decline (1981-2005), and year-class strength was positively related to catch per unit effort (CPUE; R2 = 0.58). The YCSI exceeded the 23-year mean in only 2 of the last 10 years. Cyclic patterns in the YCSI time series (along with strong year-classes every 4-6 years) were apparent, as was a dampening effect of amplitude beginning around 1990. The PLS 1 model explained over 50% of variation in both explanatory variables and the dependent variable, YCSI first-order moving-average residuals. Variables retained (N = 10; Wold's statistic ??? 0.8) included negative YCSI associations with high summer water levels, high variability in spring and fall water levels, and variability in fall water temperature. The YCSI exhibited positive associations with high spring, summer, and fall water temperature, variability in spring temperature, and high winter and spring water level. The PLS 2 model led to positive YCSI associations with phosphorus and yellow perch CPUE and a negative correlation with double-crested cormorant abundance. Environmental variables (water level and temperature) are hypothesized to regulate northern pike YCSI cycles, and dampening in YCSI magnitude may be related to a

  16. New river flow maxima in Northern England, December 2015: Implications for flood hazard and risk assessment?

    Science.gov (United States)

    Thornton, James

    2016-04-01

    December 2015 was recently confirmed as the UK's wettest month on record by the Met Office. The most extreme precipitation was associated with three extratropical storm systems, named Desmond, Eva and Frank by the pilot Met Éireann/Met Office "Name our storms" project. In response, river levels reached new maxima at many locations across Northern England. Property damage was widespread, with at least 16,000 homes in England flooded. As with recent predecessors, these events reinvigorated public debate about the extent to which natural weather variability, anthropogenic climate change, increased urbanisation and/or other changes in catchment and river management might be responsible for apparent increases in flood frequency and severity. Change detection and attribution science is required to inform the debate, but is complicated by the short (typically ~ 35 years) river flow records available. Running a large number of coupled climate and hydrological model simulations is a powerful way of addressing the 'attribution question' with respect to the hypothesised climate forcing, for example, albeit one that remains largely in the research domain at present. In the meantime, flood-frequency analysis of available records still forms the bedrock of practice in the water industry; the results are used routinely in the design of new defence structures and in the development of flood hazard maps, amongst other things. In such analyses, it is usual for the records to be assumed stationary. In this context, the specific aims of this research are twofold: • To investigate whether, under the assumption of stationarity, the outputs of standard flood-frequency modelling methods (both 'single-site' and 'spatially pooled' methods) differ significantly depending on whether the new peaks are included or excluded, and; • To assess the sustainability of previous conclusions regarding trends in English river flows by reapplying simple statistical tests, such as the Mann-Kendal test

  17. Juvenile Chinook Salmon abundance in the northern Bering Sea: Implications for future returns and fisheries in the Yukon River

    Science.gov (United States)

    Murphy, James M.; Howard, Kathrine G.; Gann, Jeanette C.; Cieciel, Kristin C.; Templin, William D.; Guthrie, Charles M.

    2017-01-01

    Juvenile Chinook Salmon (Oncorhynchus tshawytscha) abundance in the northern Bering Sea is used to provide insight into future returns and fisheries in the Yukon River. The status of Yukon River Chinook Salmon is of concern due to recent production declines and subsequent closures of commercial, sport, and personal use fisheries, and severe restrictions on subsistence fisheries in the Yukon River. Surface trawl catch data, mixed layer depth adjustments, and genetic stock mixtures are used to estimate juvenile abundance for the Canadian-origin stock group from the Yukon River. Abundance ranged from a low of 0.62 million in 2012 to a high of 2.58 million in 2013 with an overall average of 1.5 million from 2003 to 2015. Although abundance estimates indicate that average survival is relatively low (average of 5.2%), juvenile abundance was significantly correlated (r=0.87, p=0.005) with adult returns, indicating that much of the variability in survival occurs during early life-history stages (freshwater and initial marine). Juvenile abundance in the northern Bering Sea has increased since 2013 due to an increase in early life-history survival (average juveniles-per-spawner increased from 29 to 59). The increase in juvenile abundance is projected to produce larger runs and increased subsistence fishing opportunities for Chinook Salmon in the Yukon River as early as 2016.

  18. Relocation of the Yellow River estuary in 1855 AD recorded in the sediment core from the northern Yellow Sea

    Science.gov (United States)

    Zhou, Xin; Jia, Nan; Cheng, Wenhan; Wang, Yuhong; Sun, Liguang

    2013-12-01

    Relocation of the Yellow River estuary has significant impacts on not only terrestrial environment and human activities, but also sedimentary and ecological environments in coastal seas. The responses of regional geochemical characteristics to the relocation event, however, have not been well studied. In the present study, we performed detailed geochemical elemental analyses of a sediment core from the northern Yellow Sea and studied their geochemical responses to the 1855 AD relocation of the Yellow River estuary. The results show that TOC/TN, Co/Al2O3, Cr/Al2O3, Ni/Al2O3 and Se/Al2O3 ratios all decreased abruptly after 1855 AD, and similar decreases are observed in the sediments of the mud area southwest off the Cheju Island. These abrupt changes are very likely caused by the changes in source materials due to the relocation of the Yellow River estuary from the southern Yellow Sea to the Bohai Sea, which the corresponding decreasing trends caused by the changes in main source materials from those transported by the Liaohe River, the Haihe River and the Luanhe River to those by the Yellow River. Because the events have precise ages recorded in historical archives, these obvious changes in elemental geochemistry of sediments can be used to calibrate age models of related coastal sea sediments.

  19. Northern Great Plains Network water quality monitoring design for tributaries to the Missouri National Recreational River

    Science.gov (United States)

    Rowe, Barbara L.; Wilson, Stephen K.; Yager, Lisa; Wilson, Marcia H.

    2013-01-01

    The National Park Service (NPS) organized more than 270 parks with important natural resources into 32 ecoregional networks to conduct Inventory and Monitoring (I&M) activities for assessment of natural resources within park units. The Missouri National Recreational River (NRR) is among the 13 parks in the NPS Northern Great Plain Network (NGPN). Park managers and NGPN staff identified surface water resources as a high priority vital sign to monitor in park units. The objectives for the Missouri NRR water quality sampling design are to (1) assess the current status and long-term trends of select water quality parameters; and (2) document trends in streamflow at high-priority stream systems. Due to the large size of the Missouri River main stem, the NGPN water quality design for the Missouri NRR focuses on wadeable tributaries within the park unit. To correlate with the NGPN water quality protocols, monitoring of the Missouri NRR consists of measurement of field core parameters including dissolved oxygen, pH, specific conductance, and temperature; and streamflow. The purpose of this document is to discuss factors examined for selection of water quality monitoring on segments of the Missouri River tributaries within the Missouri NRR.Awareness of the complex history of the Missouri NRR aids in the current understanding and direction for designing a monitoring plan. Historical and current monitoring data from agencies and entities were examined to assess potential NGPN monitoring sites. In addition, the U.S. Environmental Protection Agency 303(d) list was examined for the impaired segments on tributaries to the Missouri River main stem. Because major tributaries integrate water quality effects from complex combinations of land use and environmental settings within contributing areas, a 20-mile buffer of the Missouri NRR was used to establish environmental settings that may impact the water quality of tributaries that feed the Missouri River main stem. For selection of

  20. Northern tamarisk beetle (Diorhabda carinulata) and tamarisk (Tamarix spp.) interactions in the Colorado River basin

    Science.gov (United States)

    Nagler, Pamela L.; Nguyen, Uyen; Bateman, Heather L.; Jarchow, Christopher; Glenn, Edward P.; Waugh, William J.; Van Riper, Charles

    2017-01-01

    Northern tamarisk beetles (Diorhabda carinulata) were released in the Upper Colorado River Basin in the United States in 2004–2007 to defoliate introduced tamarisk shrubs (Tamarix spp.) in the region’s riparian zones. The primary purpose was to control the invasive shrub and reduce evapotranspiration (ET) by tamarisk in an attempt to increase stream flows. We evaluated beetle–tamarisk interactions with MODIS and Landsat imagery on 13 river systems, with vegetation indices used as indicators of the extent of defoliation and ET. Beetles are widespread and exhibit a pattern of colonize–defoliate–emigrate, so that riparian zones contain a mosaic of completely defoliated, partially defoliated, and refoliated tamarisk stands. Based on satellite data and ET algorithms, mean ET before beetle release (2000–2006) was 416 mm/year compared to postrelease (2007–2015) ET of 355 mm/year (p<0.05) for a net reduction of 61 mm/year. This is lower than initial literature projections that ET would be reduced by 300–460 mm/year. Reasons for the lower-than-expected ET reductions are because baseline ET rates are lower than initially projected, and percentage ET reduction is low because tamarisk stands tend to regrow new leaves after defoliation and other plants help maintain canopy cover. Overall reductions in tamarisk green foliage during the study are 21%. However, ET in the Upper Basin has shown a steady decline since 2007 and equilibrium has not yet been reached. Defoliation is now proceeding from the Upper Basin into the Lower Basin at a rate of 40 km/year, much faster than initially projected.

  1. Northern Watershed Change, Modeled Permafrost Temperatures in the Yukon River Watershed

    Science.gov (United States)

    Bryan, R.; Hinzman, L. D.

    2009-12-01

    Changes in the terrestrial hydrologic cycle in northern watersheds can be seen through permafrost warming. Furthermore, vegetation shifts occur with climate changes coupled with permafrost degradation. Permafrost warming is resultant from warming air temperatures and the collection of buffers between the atmosphere and the cryosphere: the active layer, snow, and vegetation. Our modeling methods combine a meteorological model with a permafrost temperature model in 1 km2 resolution in the 847,642 km2 Yukon River Watershed. The MicroMet model is a quasi-physically based model developed in 2006 by Liston & Elder to spatially interpolate irregularly spaced point meteorological data using known temperature-elevation, wind-topography, humidity-cloudiness, and radiation-cloud-topography relationships. We call on 1997-2007 data from 104 Integrated Surface Data meteorological stations and 100 grid points in a 5 best models ensemble A1B 2090-2100 projection. The Temperature at the Top of the Permafrost (TTOP) model is a numerical model for estimating the thermal state of permafrost. This model is attributed to Smith & Riseborough, 1996. TTOP relates more readily available near surface temperatures to temperatures at the depth of seasonal variation using user-defined landcover n-factors (to relate air temperature to soil surface temperature) and soil thermal conductivities (to simulate the propagation of heat through the active layer). TTOP simulates warm top of the permafrost temperatures for high soil thermal conductivity, land cover with high n-factor, and a high number of thawing degree-days/ year. Here we compare the present and future thermal stability of permafrost in the Yukon River Watershed.

  2. Quantification of Modeled Streamflow under Climate Change over the Flint River Watershed in Northern Alabama

    Science.gov (United States)

    Acharya, A.; Tadesse, W.; Lemke, D.; Subedi, S.

    2015-12-01

    This study is carried out to quantify the impacts of climate change and land use change on water availability over the Flint River watershed (FRW) located in the wheeler lake watershed in Northern Alabama. The FRW directly drains into the Tennessee River, which is a major source of water supply for the Southern States. The observed precipitation and temperature data are obtained from the Alabama Mesonet Stations which are also a part of National Resources Conservation Service (USDA NRCS) Soil Climate Analysis Network (SCAN). The GCM simulated climate data are obtained from the WCRP CMIP5 ensemble that consists of 234 downscaled climate projections from four emission scenarios and 37 GCMs. The hydrologic model SWAT is calibrated and validated for a period of 2004 to 2014, based on daily meteorological forcing and monthly streamflow data for the FRW. A total of 15 parameters that directly influences the surface/base flow and basin response are selected and calibrated. The anticipated change in future climate (2030s, 2050s, 2070s, 2090s) with respect to baseline period (2004-2014/2010s) for each emission scenario are introduced into baseline climate to perturb it to future climate pattern. Various climate scenarios based on future climate are forced into the calibrated SWAT model to quantify future water availability over the basin and compared with the baseline period. This is a part of the Geospatial Education and Research Center (GERC) project and the major research findings from this project will help decision makers in evaluating the combined impacts of climate change and land use change on water availability, and developing strategies to sustain available natural resources.

  3. Environmental Impact Study of the Northern Section of the Upper Mississippi River, Upper and Lower St. Anthony Falls Pool.

    Science.gov (United States)

    1973-11-01

    Icress Rorippa obtusa Obtuse yellow cress Unidentified sp. P I CUCURBITACEAE Sicyos angulatus Bur-cucumber1 CYPERACEAE Carex aenca Sedge Carex annectens...Bitter- White oak Little bluestem Reed-canary- Sedges flackbcrry nut White pine Nodding grama grass Milkweed Green ash hickory Sugar maple Northern Rice...Aster Cottonwood Hackbcrry Paper birch dropseed cutgrass Blue-joint Silver maple Ironwood Ironwood Hairy grama River sedge grass Slippery Bur oak Red

  4. Unconformity-related uranium deposits, Athabasca area, Saskatchewan, and East Alligator Rivers area, Northern Territory, Australia

    Energy Technology Data Exchange (ETDEWEB)

    Clark, L.A.; Burrill, G.H.R. (Saskatchewan Mining Development Corp., Saskatoon (Canada))

    1981-07-01

    Most unconformity-type uranium deposits in Saskatchewan occur within a few tens of metres above and/or below the basal unconformity of the 1.45 b.y. Athabasca Sandstone. Graphitic basement rocks coincident with post-Athabasca faulting or brecciation at or near the unconformity are important in localizing uranium deposits which form as tabular, ribbon-like bodies with grades averaging over 2 percent uranium and containing up to 50,000 tonnes U/sub 3/O/sub 8/. Some of these deposits have similar contents of nickel and arsenic. In the genetic model used to explain these deposits, traces of uranium were leached from the sandstone and basement rocks by oxidized formation waters. A thick clay regolith absorbed uranium from the solution, and the fixed uranium was reduced through an indirect reaction with graphite. The clay mineral surfaces were thus continuously cleared to allow further adsorption. Fluid convection was induced by topographic relief and/or crustal heating from radioactive decay, and would continue uranium deposition until all permeability was plugged by minerals. The East Alligator Rivers uranium deposits in Northern Territory, Australia occur within Middle Proterozoic quartz-chlorite and quartz-muscovite schists overlain by sandstone. Highest grades occur in silicified breccias where carbonate beds were leached out. Mineralization ages are both pre- and post-Kombolgie Sandstone, but, to date, no significant uranium mineralization has been found in the sandstone. There are many similarities with Saskatchewan deposits, but also important differences.

  5. Essential oils from Leptospermums of the Sunshine Coast and Northern Rivers Regions

    Directory of Open Access Journals (Sweden)

    Windsor Sarah Alison

    2012-05-01

    Full Text Available Abstract Background Around the turn of this century, the oil yield and chemical composition of Australian Leptospermum species was analysed. Since that time, research has been focused on their use as phytomedicines. The oil yield and composition of essential oils from Australian Leptospermum species directly impacts their commercialisation for medicinal use. Results The essential oils from Leptospermum (L. juniperinum, L. laevigatum, L. liversidgei, L. polygalifolium, L. semibaccatum, L. speciosum, L. trinervium and L. whitei have been examined from specimens in the Sunshine Coast (Queensland and Northern Rivers (New South Wales Regions. Both chemotypes of L. liversidgei were observed. However, only chemotype II of L. semibaccatum and chemotype I of L. trinervium were identified. The only subspecies observed of L. polygalifolium was L. polygalifolium wallum. Conclusions L. liversidgei chemotypes I and II have the potential for phytomedical use as antibacterial or anti-inflammatory agents. Chemotype I has the potential for use as an insect repellent and chemotype II may provide antifungal activity.

  6. WRF-model data assimilation studies of landfalling atmospheric rivers and orographic precipitation over Northern California

    Science.gov (United States)

    Eiserloh, Arthur J., Jr.

    In this study, data assimilation methods of 3-D variational analysis (3DVAR), observation nudging, and analysis (grid) nudging were evaluated in the Weather Research and Forecasting (WRF) model for a high-impact, multi-episode landfalling atmospheric river (AR) event for Northern California from 28 November to 3 December, 2012. Eight experiments were designed to explore various combinations of the data assimilation methods and different initial conditions. The short-to-medium range quantitative precipitation forecast (QPF) performances were tested for each experiment. Surface observations from the National Oceanic and Atmospheric Administration's (NOAA) Hydrometeorology Network (HMT), National Weather Service (NWS) radiosondes, and GPS Radio Occultation (RO) vertical profiles from the Constellation Observing System for Meteorology Ionosphere and Climate (COSMIC) satellites were used for assimilation. Model results 2.5 days into the forecast showed slower timing of the 2nd AR episode by a few hours and an underestimation in AR strength. For the entire event forecasts, the non-grid-nudging experiments showed the lowest mean absolute error (MAE) for rainfall accumulations, especially those with 3DVAR. Higher-resolution initial conditions showed more realistic coastal QPFs. Also, a 3-h nudging time interval and time window for observation nudging and 3DVAR, respectively, may be too large for this type of event, and it did not show skill until 60-66 h into the forecast.

  7. Occurrence, habitat, and movements of the endangered northern madtom (Noturus stigmosus) in the Detroit River, 2003-2011

    Science.gov (United States)

    Manny, Bruce A.; Daley, Bryon A.; Boase, James C.; Horne, Ashlee N.; Chiotti, Justin A.

    2014-01-01

    The northern madtom (Noturus stigmosus or NOM) is a small catfish, native to North America. It is globally vulnerable and endangered in Canada, Ontario, and Michigan. In 1994 and 1996, it was found in the St. Clair River and in Lake St. Clair, respectively. However, it had not been found downstream in the Detroit River since 1978. We report catches of 304 NOM from 2003 to 2011 and describe their mud and sand habitats in the deep (10 m), dark, Detroit River. We found adult NOM, including 3 ripe males (90–107 mm SL) in head waters of the river near Belle Isle in Michigan waters, and both adult and 4 juvenile NOM (21–30 mm SL) near Peche Island in Ontario waters. From 2009 to 2011, in the river's middle reach, we caught 7 adult NOM for the first time near Fighting Island in Ontario waters, but no NOM in the river's lower reach. Our mark–recapture results showed that within 6 weeks, 2 adult NOM moved east 2.0 km from Michigan waters near Belle Isle across the deep (10 m) Fleming Channel of the Detroit River to Canadian waters near Peche Island. Analysis of annuli from pectoral spines of 7 dead NOM revealed that they live to at least 6 years of age in the Detroit River. This is the first age data that we could find for a NOM population. Our findings extended our knowledge of habitat, reproductive ecology, age, and distribution of NOM in the Detroit River corridor.

  8. Mapping of buried river terraces on the Kopite Hill, Gerecse Mts., Northern Hungary

    Science.gov (United States)

    Kiss, Dániel; Szőts, Gergely K.; Ruszák, Zsófia; Bereczki, László; Molnár, Gábor; Timár, Gábor; Fodor, László; Csillag, Gábor; Lantos, Zoltán

    2015-04-01

    The Gerecse Mountains is a part of the Transdanubian Mountain Range. The Kopite Hill located on the northern part of the Gerecse Mountains, on the southern side of the Danube and the Hungarian-Slovakian border. At the southern side of the Danube (100 m a.s.l.) a 290 m high hill of Pannonian (Miocene) marine clay, silt and sand can be found. These Pannonian strata are covered with Pliocene-Pleistocene alluvial sediments, loess and travertine. On the Kopite Hill some small outcrops of gravel can be found, which thought to be one of the highest river terrace levels, but it is not proved. To the northwest there is 270-300 m high plateau of the 'Roman-quarry' with a formerly mined travertine-body. According to a recent discovery a Mammoth-tooth and other fossils of mammals were found there, which were dated and correlated. Because the travertine body is at lower height than the assumed terrace level, a maximum rate of uplift can be given. The aim of our fieldwork was to determine the geometry of gravel strata and the connections between the distinct outcrops and the travertine body. We used multielectrode measurements with supplementary VES measurements. We found that on the north side of Kopite Hill and to south from the Roman-quarry there is an almost horizontal 300*100 m large, 8-13 m thick pebble stratum. Direct connection to the travertine body is not possible, because there is a few tens of meters gap between the two bodies, filled with loess. We assume the gravel stratum with its 258-252 m height (gently dips to the south) is a river terrace. On the southest point of this river terrace the thickness of the gravel suddenly increases to 22 meters. To the south there are also some gravel outcrops, and also a drill which suggest that the bottom of these gravels are higher on higher level, about at 265 m a.s.l.. We interpret this phenomenon as a higher terrace level. With the use of geoelectrical methods we could determine the geometry of gravel stratum on the Kopite

  9. Holocene floodplain evolution in the Shiribeshi-Toshibetsu River lowland, northern Japan

    Science.gov (United States)

    Ishii, Yuji

    2017-09-01

    The influence of sea-level and climate changes on the evolution of coastal floodplains is an important problem in fluvial geomorphology and geology. However, few studies have constructed detailed chronologies of floodplain evolution, and the influence of sea-level and climate changes at submillennial time scales is not clear. This study investigated the Holocene evolution of the floodplain in the Shiribeshi-Toshibetsu River lowland, Hokkaido, northern Japan, based on 13 auger cores, 15 radiocarbon ages, and 2 cross sections made using existing columnar sections. In the study area, peat beds 3-6 m thick in the uppermost Holocene sediments are underlain by fluvial sediment that mainly consists of sand beds resulting from crevassing or progradational avulsion. Age-elevation plots of the bases of these peat beds suggest that fluvial aggradation was continuous until peat formation began, which in turn suggests that peat beds began to form with the cessation of fluvial deposition. The chronology of floodplain sediments based on radiocarbon ages indicates that peatlands began to develop locally before ca. 6500 cal BP and became moderately widespread before 5600 cal BP. Peatlands then became more extensive after two periods of rapid expansion during ca. 5300-5000 and 4100-3900 cal BP. Comparison with sea-level and regional climate changes suggests that the initiation of these peat beds before 5600 cal BP was associated with the deceleration of sea-level rise at ca. 7000 cal BP. The two later periods of peatland expansion may have been strongly influenced by reduced fluvial activity due to decreased precipitation from a weakened East Asian summer monsoon. This interpretation suggests that floodplain evolution was controlled by sea-level and climate changes and that the response to climate change occurred at submillennial time scales. A comparison with the Ishikari lowland on Hokkaido showed that the two floodplains have slightly different histories, possibly because of

  10. Biomarkers of contaminant exposure in northern pike (Esox lucius) from the Yukon River Basin, Alaska

    Science.gov (United States)

    Hinck, J.E.; Blazer, V.S.; Denslow, N.D.; Myers, M.S.; Gross, T.S.; Tillitt, D.E.

    2007-01-01

    As part of a larger investigation, northern pike (n = 158; Esox lucius) were collected from ten sites in the Yukon River Basin (YRB), Alaska, to document biomarkers and their correlations with organochlorine pesticide (total p,p'-DDT, total chlordane, dieldrin, and toxaphene), total polychlorinated biphenyls (PCBs), and elemental contaminant (arsenic, cadmium, copper, lead, total mercury, selenium, and zinc) concentrations. A suite of biomarkers including somatic indices, hepatic 7-ethoxyresorufin O-deethylase (EROD) activity, vitellogenin concentrations, steroid hormone (17B- ustradiol and 16-kebtestosteront) concentrations, splenic macrophage aggregates (MAs), oocyte atresia, and other microscopic anomalies in various tissues were documented in YRB pike. Mean condition factor (0.50 to 0.68), hepatosomatic index (1.00% to 3.56%), and splenosomatic index (0.09% to 0.18%) were not anomalous at any site nor correlated with any contaminant concentration. Mean EROD activity (0.71 to 17.51 pmol/min/mg protein) was similar to basal activity levels previously measured in pike and was positively correlated with selenium concentrations (r = 0.88, P 63 ng/g), and MA-% values in female pike (0.24% to 0.54%) were lower than in male pike (0.32% to 0.75%) at similar PCB concentrations. Greater numbers of MAs were found as zinc concentrations increased in YRB female pike, but it is unlikely that this is a causative relationship. Histological abnormalities observed in gill, liver, spleen, and kidney tissues were not likely a result of contaminant exposure but provide information on the general health of YRB pike. The most common histologic anomalies were parasitic infestations in various organs and developing nephrons and nephrocalcinosis in posterior kidney tissues. Overall, few biomarker responses in YRB pike were correlated with chemical contaminant concentrations, and YRB pike generally appeared to be healthy with no site having multiple anomalous biomarker responses. ?? 2007

  11. Holocene environment changes around the Sara Us River, northern China, revealed by optical dating of lacustrine-aeolian sediments

    Science.gov (United States)

    Zhao, Hui; Sheng, Yongwei; Li, Bo; Fan, Yuxin

    2016-04-01

    The Sara Us River is located along the boundary of the Mu Us Desert and the Chinese Loess Plateau in northern China. The river has cut down through Quaternary sediments creating 70-80 m deep valleys with thick lacustrine/aeolian sequences exposed. We applied optical stimulated luminescence on sediments from a Holocene section of aeolian sand/lacustrine deposits in the top of the river valley. The dating results show that a humid period existed from 7.1 to 2.0 ka ago as evidenced by two layers of peat and lacustrine sediments. However, compared to other published Holocene sections in the Sara Us River valleys close to the section under studying, the local environment experienced very complicated changes during the Holocene. All of the sections recorded a period with drought and/or cold before the Holocene at around 13 ka, and an episode of aridity after about 2 ka ago as evidenced by the layers of aeolian sand. However, the ages of the lacustrine and peat layers in these sections are substantially different. Geomorphological analysis by digital elevation models does not support the existence of a mega lake covering the study area at 2 ka. The intricate environmental changes may have been caused by the meandering of the Sara Us River. Environmental changes also strongly affected human migration in this area, which is documented by Chinese historical records.

  12. Multi-century tree-ring based reconstruction of the Neuquén River streamflow, northern Patagonia, Argentina

    Directory of Open Access Journals (Sweden)

    I. A. Mundo

    2012-04-01

    Full Text Available In most cases, gauged river flow records in southern South America extend for only a few decades, hampering the detection of long-term, decadal to centennial-scale cycles and trends. Long streamflow series can be reconstructed from tree-ring records, offering the opportunity of extending the limited hydrological instrumental data to several centuries. In northern Patagonia, Argentina, the Neuquén River has great importance for local and national socio-economic activities such as hydroelectric power generation, agriculture and tourism. In this study, new and updated tree-ring chronologies from Araucaria araucana and Austrocedrus chilensis are used to reconstruct the October–June mean streamflow for the Neuquén River and place the period of gauged flows (1903–2009, in a long-term, multi-century context. The reconstruction covers the period 1346–2000 AD and was developed from a network of 43 tree-ring chronologies, grouped in composite series, using a nested principal component regression approach. Analyses of the frequency, intensity, and duration of droughts and pluvial events indicate that the 20th century contains some of the driest and wettest annual to decadal-scale events in the last 654 yr, but longer and more severe events were recorded in previous centuries. Blackman-Tukey and singular spectral analyses identified quasiperiodic oscillations from 3.5 to 17.5 yr. A dominant 6.8-yr cycle explains ca. 23.6% of the total variance in the Neuquén River streamflow reconstruction. Correlation analyses showed that discharges of the Neuquén River are related to variations in the Southern Annular Mode (SAM, a measure of air mass exchanges between middle and high latitudes in the Southern Hemisphere. This association is consistent with previous studies that indicate a strong correlation between rainfall in northern Patagonia and SAM variations.

  13. Multi-century tree-ring based reconstruction of the Neuquén River streamflow, northern Patagonia, Argentina

    Science.gov (United States)

    Mundo, I. A.; Masiokas, M. H.; Villalba, R.; Morales, M. S.; Neukom, R.; Le Quesne, C.; Urrutia, R. B.; Lara, A.

    2012-04-01

    In most cases, gauged river flow records in southern South America extend for only a few decades, hampering the detection of long-term, decadal to centennial-scale cycles and trends. Long streamflow series can be reconstructed from tree-ring records, offering the opportunity of extending the limited hydrological instrumental data to several centuries. In northern Patagonia, Argentina, the Neuquén River has great importance for local and national socio-economic activities such as hydroelectric power generation, agriculture and tourism. In this study, new and updated tree-ring chronologies from Araucaria araucana and Austrocedrus chilensis are used to reconstruct the October-June mean streamflow for the Neuquén River and place the period of gauged flows (1903-2009), in a long-term, multi-century context. The reconstruction covers the period 1346-2000 AD and was developed from a network of 43 tree-ring chronologies, grouped in composite series, using a nested principal component regression approach. Analyses of the frequency, intensity, and duration of droughts and pluvial events indicate that the 20th century contains some of the driest and wettest annual to decadal-scale events in the last 654 yr, but longer and more severe events were recorded in previous centuries. Blackman-Tukey and singular spectral analyses identified quasiperiodic oscillations from 3.5 to 17.5 yr. A dominant 6.8-yr cycle explains ca. 23.6% of the total variance in the Neuquén River streamflow reconstruction. Correlation analyses showed that discharges of the Neuquén River are related to variations in the Southern Annular Mode (SAM), a measure of air mass exchanges between middle and high latitudes in the Southern Hemisphere. This association is consistent with previous studies that indicate a strong correlation between rainfall in northern Patagonia and SAM variations.

  14. Multi-century tree-ring based reconstruction of the Neuquén River streamflow, northern Patagonia, Argentina

    Directory of Open Access Journals (Sweden)

    I. A. Mundo

    2011-10-01

    Full Text Available In most cases, gauged river flow records in southern South America exist for only a few decades, hampering the detection of long-term, decadal to centennial-scale cycles and trends. Long streamflow series can be reconstructed from tree-ring records, offering the opportunity of extending the limited hydrological instrumental data for several centuries or millennia. In northern Patagonia, Argentina, the Neuquén River has great importance for local and national socio-economic activities such as hydroelectric power generation, agriculture and tourism. In this study, new and updated tree-ring chronologies from Araucaria araucana and Austrocedrus chilensis are used to reconstruct the October–June mean streamflow for the Neuquén River and place the period of gauged flows, 1903–2009, in a long-term, multi-century context. The reconstruction covers the period 1346–2000 AD and was developed through a nested principal components regression approach using a network of 43 tree-ring chronologies grouped in composite series. Analyses of the frequency, intensity, and duration of droughts and pluvial events indicate that the 20th century contains some of the driest and wettest annual to decadal-scale events in the past millennium, but longer and more severe events can also be observed in previous centuries. Blackman-Tukey and Singular Spectral Analyses identified various multi-decadal quasiperiodic oscillations with a dominant 6.8-year cycle explaining ca. 23.6% of the total variance in the Neuquén River streamflow reconstruction. We also found that the Neuquén River discharges are related to variations in the Southern Annular Mode (SAM, a measure of air mass exchanges between middle and high latitudes in the Southern Hemisphere. This association is consistent with previous studies which indicate a strong connection between rainfall patterns in northern Patagonia and SAM activity.

  15. 10 years after the largest river restoration project in Northern Europe

    DEFF Research Database (Denmark)

    Astrup Kristensen, Esben Astrup; Kronvang, B.; Wiberg-Larsen, P.;

    2014-01-01

    The lower river Skjern (Denmark) historically contained a large variation in habitats and the river ran through large areas with wetlands, many backwaters, islands and oxbow lakes. During the 1960s the river was channelized and the wetland drained. A restoration during 2001–2002 transformed 19 km...

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

    Science.gov (United States)

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

    2016-01-01

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

  17. Diet of non-native northern snakehead (Channa argus) compared to three co-occurring predators in the lower Potomac River, USA

    Science.gov (United States)

    Ryan K. Saylor,; Nicolas W.R. Laointe,; Angermeier, Paul

    2012-01-01

    Introductions of large, non-native, carnivorous fishes continue to occur worldwide and represent a substantial management concern to global biodiversity. One of the most recent non-native fishes to successfully establish in North America is the northern snakehead (Channa argus), found in the lower Potomac River catchment. Dispersal of the northern snakehead throughout this system has been well documented since its original discovery in May 2004; however, little is known about the foraging habits of this species and its interactions with co-occurring predators. Here, we quantify northern snakehead diet in comparison with the diets of naturalised largemouth bass (Micropterus salmoides), and native American eel (Anguilla rostrata) and yellow perch (Perca flavescens) collected from tidal freshwaters bordering Virginia and Maryland near Fort Belvoir, Virginia. Over 97% of northern snakehead gut contents were fishes, with fundulid and centrarchid species consumed most frequently. Dietary overlap was biologically significant only between northern snakehead and largemouth bass. Aquatic invertebrates were >10 times more common in native predator diets, reducing dietary overlap with northern snakehead. Ontogenic shifts in adult northern snakehead diet were also detected, which may be explained by optimal foraging rather than true prey specificity. Northern snakehead may be occupying a novel niche based on a piscivorous diet, therefore limiting competition with resident predators in the lower Potomac River. Further research into interactions between largemouth bass and northern snakehead is needed to inform management decisions and understand the ecological impacts of this non-native species.

  18. Spatiotemporal Distribution of Metals along a Salinity Gradient in a River Estuary of the Northern Gulf of Mexico

    Science.gov (United States)

    He, S.; Xu, Y. J.

    2015-12-01

    Saltwater intrusion has become a significant problem for many coastal rivers due to global climate change and the continuous sea level rise. The flocculation of dissolved metals during estuarine mixing plays a critical role in self-purification of metals. A number of studies have investigated pH and salinity effects on metal mobility. Many of these studies were conducted in a laboratory setting. The reported field studies considered only few metals and their dynamics under marginal pH / salinity variation, typically over a short period of time. Since the spring of 2013, we have been conducting a study on spatiotemporal distribution of metals along a 90-km reach of the Calcasieu River estuary in the northern Gulf of Mexico. Monthly field trips were made to conduct in-situ measurements and collect water samples at six sites along the river. In addition, sediment samples from the riverbed surface were collected at the same sites four times to assess metal accumulation. Field measurements included water temperature, pH, salinity, and specific conductivity; Water samples were analyzed for concentration of a range of metals including Al, Ba, B, Cd, Ca, Cr, Cu, Fe, Pb, Li, Mg, Mn, Ni, P, K, Si, Ag, Na, Sr, Ti, V, and Zn. The estuarine river reach showed a wide range of salinity and pH (salinity: 0.04 - 21.78 ppt; pH: 6.2-8.1), strongly affected by river hydrology and tidal mixing. Concentration and spatial distribution of the metals in river water show response to flow regimes from the low (400 cfs) to the intermediate (400-2600 cfs) and high flows. This paper presents the dynamics of the metals under varying flow, pH and salinity gradients over the seasons and discusses a potential "intrusion" of metal accumulation in riverbed upstream as sea level rise persists.

  19. Analysis of benthic macroinvertebrates and biotic indices to evaluate water quality in rivers impacted by mining activities in northern Chile

    Directory of Open Access Journals (Sweden)

    Alvial I.E.

    2013-02-01

    Full Text Available Catchments in the semiarid regions are especially susceptible to environmental perturbation associated with water scarcity, hydrological variations and overuse by anthropogenic activities. Using multivariate analysis to relate environmental and biological data, and diversity and biotic indices (ChBMWP, ChIBF, we analyzed the macroinvertebrate composition of 12 rivers of the semiarid region of northern Chile. A non-metric multidimensional scaling for macroinvertebrate taxa and a principal component analysis for environmental variables strongly separated upstream sites (e.g. Vacas Heladas and Malo Rivers, which presented low pH and high dissolved metal concentrations, from other sites. Effectively, CCA showed that metals and low pH, associated with the altitudinal gradient, determined the distributional patterns of macroinvertebrates in the Elqui catchment. The causes of these particular conditions could be related to geological processes and human impact. The biotic indices applied to the sampling sites corroborated and reflected these characteristics, with La Laguna and Turbio Rivers showing a diverse macroinvertebrate community and moderate to good water quality, and the Claro River showing favorable conditions for the development of aquatic biota, indicating its better quality relative to other stations. To the middle and low part of the basin, a change in the composition of the community was observed, with species that suggest an impact by an increase in organic matter, due to agricultural activities and urban settlements concentrated in this area. Our results suggest that macroinvertebrate taxa in northern Chile may be exceptional species, adapted to unfavorable geochemical conditions, and emphasize the need for protection of the semiarid basins of the region.

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

    Directory of Open Access Journals (Sweden)

    Gula Tang

    2016-04-01

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

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

    Science.gov (United States)

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

    2016-01-01

    In this study, the Mudan River, which is the most typical river in the northern cold region of China was selected as the research object; Environmental Fluid Dynamics Code (EFDC) was adopted to construct a new two-dimensional water quality model for the urban sections of the Mudan River, and concentrations of CODCr and NH3N during ice-covered and open-water periods were simulated and analyzed. Results indicated that roughness coefficient and comprehensive pollutant decay rate were significantly different in those periods. To be specific, the roughness coefficient in the ice-covered period was larger than that of the open-water period, while the decay rate within the former period was smaller than that in the latter. In addition, according to the analysis of the simulated results, the main reasons for the decay rate reduction during the ice-covered period are temperature drop, upstream inflow decrease and ice layer cover; among them, ice sheet is the major contributor of roughness increase. These aspects were discussed in more detail in this work. The model could be generalized to hydrodynamic water quality process simulation researches on rivers in other cold regions as well. PMID:27070631

  2. In-stream production of methylmercury in a northern California river during summer baseflow

    Science.gov (United States)

    Tsui, M. T.; Finlay, J. C.; Nollet, Y. H.; Balogh, S. J.

    2009-12-01

    In stream ecosystems, it is well established that terrestrial landscape features such as wetlands are important in determining the aqueous concentration and flux of methylmercury. In contrast, our understanding of in-stream production of methylmercury is inadequate, especially on an ecosystem scale. In this study, we examined the relationship between the net production of dissolved methylmercury and algal metabolism in an 8-km reach of a third order stream (South Fork Eel River) in northern California. The stream has a forested watershed with no wetlands and has a long period of baseflow that typically extends from late May to early October. There was an intense rainfall in early May, 2009, but no major precipitation was recorded afterward, as is typical of Mediterranean climate of the study site. We collected surface water samples along the main channel and four major tributaries to the study stream reach. Temporal patterns of algal metabolism were inferred from net changes in total dissolved phosphorus and silica uptake and algal abundance. There was essentially no net production of methylmercury within the study reach (~ 0 µg Hg/km/d) in mid-May but net production of methylmercury occurred afterward when discharge declined exponentially, water temperature increased and algal metabolism increased (i.e. phosphorus and silica were taken up biologically). Net production of dissolved methylmercury peaked in mid-June (100 µg Hg/km/d) and then declined in mid-July (58 µg Hg/km/d) and mid-August (45 µg Hg/km/d) within the 8-km reach. The absence of surface runoff during the summer (e.g. June through September) indicates that the observed net production of methylmercury occurred within the channel and algal metabolism is coupled to the mercury methylation process. In summary, our study suggests that, in addition to watershed features, in-stream production of methylmercury should be considered as an important factor mediating mercury bioavailability in flowing waters

  3. Biomarkers of contaminant exposure in Northern Pike (Esox lucius) from the Yukon River Basin, Alaska.

    Science.gov (United States)

    Hinck, J E; Blazer, V S; Denslow, N D; Myers, M S; Gross, T S; Tillitt, D E

    2007-05-01

    As part of a larger investigation, northern pike (n = 158; Esox lucius) were collected from ten sites in the Yukon River Basin (YRB), Alaska, to document biomarkers and their correlations with organochlorine pesticide (total p,p'-DDT, total chlordane, dieldrin, and toxaphene), total polychlorinated biphenyls (PCBs), and elemental contaminant (arsenic, cadmium, copper, lead, total mercury, selenium, and zinc) concentrations. A suite of biomarkers including somatic indices, hepatic 7-ethoxyresorufin O-deethylase (EROD) activity, vitellogenin concentrations, steroid hormone (17B- ustradiol and 16-kebtestosteront) concentrations, splenic macrophage aggregates (MAs), oocyte atresia, and other microscopic anomalies in various tissues were documented in YRB pike. Mean condition factor (0.50 to 0.68), hepatosomatic index (1.00% to 3.56%), and splenosomatic index (0.09% to 0.18%) were not anomalous at any site nor correlated with any contaminant concentration. Mean EROD activity (0.71 to 17.51 pmol/min/mg protein) was similar to basal activity levels previously measured in pike and was positively correlated with selenium concentrations (r = 0.88, P pike were not correlated with any contaminant, but vitellogenin concentrations >0.01 mg/mL in male pike from multiple sites indicated exposure to estrogenic compounds. Mean steroid hormone concentrations and percent oocyte atresia were not anomalous in pike from any YRB site. Few site differences were significant for mean MA density (1.86 to 6.42 MA/mm(2)), size (812 to 1481 microm(2)), and tissue occupied (MA-%; 0.24% to 0.75%). A linear regression between MA-% and total PCBs was significant, although PCB concentrations were generally low in YRB pike (pike (0.24% to 0.54%) were lower than in male pike (0.32% to 0.75%) at similar PCB concentrations. Greater numbers of MAs were found as zinc concentrations increased in YRB female pike, but it is unlikely that this is a causative relationship. Histological abnormalities observed in

  4. Using 239Pu as a tracer for fine sediment sources in the Daly River, Northern Australia

    Science.gov (United States)

    Lal, R.; Fifield, L. K.; Tims, S. G.; Wasson, R. J.; Howe, D.

    2015-04-01

    The Daly River drains a large (52500 km2) and mainly undisturbed catchment in the Australian wet-dry tropics. Clearing and cropping since 2002 have raised concerns about possible increased sediment input into the river and motivated this study of its fine sediment sources. Using 239Pu as a tracer it is shown that the fine sediments originate mainly from erosion by gullying and channel change. Although the results also indicate that the surface soil contribution to the river channel sediments from sheet erosion has increased to 5-22% for the Daly River and 7-28% for the Douglas River (a tributary of the Daly River) in 2009 vs. 3-6% for the Daly River and 4-9% for the Douglas River in 2005. This excess top soil likely originates from thecleared land adjacent to the Daly River since 2005. However, channel widening largely as a result of hydrologic change is still the dominant sediment source in this catchment.

  5. Using 239Pu as a tracer for fine sediment sources in the Daly River, Northern Australia

    Directory of Open Access Journals (Sweden)

    Lal R.

    2015-01-01

    Full Text Available The Daly River drains a large (52500 km2 and mainly undisturbed catchment in the Australian wet–dry tropics. Clearing and cropping since 2002 have raised concerns about possible increased sediment input into the river and motivated this study of its fine sediment sources. Using 239Pu as a tracer it is shown that the fine sediments originate mainly from erosion by gullying and channel change. Although the results also indicate that the surface soil contribution to the river channel sediments from sheet erosion has increased to 5-22% for the Daly River and 7-28% for the Douglas River (a tributary of the Daly River in 2009 vs. 3-6% for the Daly River and 4-9% for the Douglas River in 2005. This excess top soil likely originates from thecleared land adjacent to the Daly River since 2005. However, channel widening largely as a result of hydrologic change is still the dominant sediment source in this catchment.

  6. Garra waensis, a new cyprinid fish (Actinopterygii: Cypriniformes) from the Nan River Basin of the Chao Phraya River system, northern Thailand.

    Science.gov (United States)

    Lothongkham, Amornchai; Arbsuwan, Sakda; Musikasinthorn, Prachya

    2014-04-23

    A new cyprinid fish, Garra waensis, is described from the Wa River, a tributary of the Nan River of the Chao Phraya River system in northern Thailand. The species is distinguishable from its congeners by the combination of the following characters: the absence of barbels; 7 branched dorsal fin rays; 31-37 lateral-line scales; 10-12 circumpeduncular scales; a small and broad head (head length [HL] 22.7-26.1% in standard length, head depth 56.1-64.9% HL, head width 74.0-85.0 % HL); a weakly developed proboscis in front of nostrils; the presence of reddish-orange spots (white or dull yellowish white in preserved specimens) on the side of the body; and a dark mid-lateral stripe running from the upper edge of the gill opening to the caudal peduncle and expanding into a large anteriorly-pointed triangular blotch at the end of the body (in preserved condition). A vomero-palatine organ of the species is also described in detail for the first time for Asian species of Garra. The genus Placocheilus is treated as a junior synonym of Garra. 

  7. 76 FR 70866 - Expansions of the Russian River Valley and Northern Sonoma Viticultural Areas

    Science.gov (United States)

    2011-11-16

    ... adequate information as to the identity and quality of the product. The Alcohol and Tobacco Tax and Trade... of the Russian River watershed. Finally, the petitioner included a Russian River Valley area tourism... and climate for Pinot Noir and Chardonnay. (``Diverse Geology/Soils Impact Wine Quality,'' by Terry...

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

    African Journals Online (AJOL)

    2011-02-16

    Feb 16, 2011 ... 1South African Sugarcane Research Institute, Private Bag X02, Mount ... Increasing demand for and use of water resources in these catchments has led to .... is located within the 50 000 km2 Inkomati River Basin, of ...... in river water pH reflecting the acidifying effect of acid mine ... First flush phenomenon,.

  9. Environmental Impact Study of the Northern Section of the Upper Mississippi River. Pool 9.

    Science.gov (United States)

    1973-11-01

    basedl on !u o, 1973 survo- vrio 145 served on the river per hour of oav use is al o g reate. t in tht uper two- thirds of Pool 9. The numbers of people...Upper Mississippi River Comprehensive Basin Study. 1970. Appendix J. page 90. U.S. Public Health Service U.S. Department of Health, Education , and

  10. Benthic Macroinvertebrate Communities in the Northern Tributaries of the “Iron Gates” Gorge (Danube River

    Directory of Open Access Journals (Sweden)

    Curtean-Bănăduc Angela

    2014-12-01

    Full Text Available The paper presents the structure of the benthonic macro-invertebrates communities in the Berzasca, Sirinia, Liubcova, and Mraconia rivers. The results are based on quantitative benthos samples (95 samples, collected in July 2014 from 19 sampling stations within the study area. In longitudinal profile, the benthonic macro-invertebrate communities of the Sirinia, Liubcova and Berzasca rivers displays relatively large structural variability, while the communities of the Mraconia River displays smaller structural variability. The structure of the benthonic macro-invertebrate communities correlated with the biotope characteristics indicates the good ecological status of the analysed rivers, with the exception of the Berzasca River sector downstream of the town of Berzasca and immediately upstream of the Danube junction, a sector with moderate ecological status due to negative effects from man-made modifications in the lotic biotope of the sector.

  11. Measured and predicted environmental concentrations of carbamazepine, diclofenac, and metoprolol in small and medium rivers in northern Germany.

    Science.gov (United States)

    Meyer, Wibke; Reich, Margrit; Beier, Silvio; Behrendt, Joachim; Gulyas, Holger; Otterpohl, Ralf

    2016-08-01

    This study evaluated the impact of secondary municipal effluent discharge on carbamazepine, diclofenac, and metoprolol concentrations in small and medium rivers in northern Germany and compared the measured environmental concentrations (MECs) to the predicted environmental concentrations (PECs) calculated with four well-established models. During a 1-year sampling period, secondary effluent grab samples were collected at four wastewater treatment plants (WWTPs) together with grab samples from the receiving waters upstream and downstream from the wastewater discharge points. The carbamazepine, diclofenac, and metoprolol concentrations were analyzed with high-performance liquid chromatography-tandem mass spectrometry (HPLC/MS-MS) after solid phase extraction. In the secondary effluents, 84-790 ng/L carbamazepine, 395-2100 ng/L diclofenac, and 745-5000 ng/L metoprolol were detected. The carbamazepine, diclofenac, and metoprolol concentrations analyzed in the rivers downstream from the secondary effluent discharge sites ranged from <5 to 68, 370, and 520 ng/L, respectively. Most of the downstream pharmaceutical concentrations were markedly higher than the corresponding upstream concentrations. The impact of wastewater discharge on the MECs in rivers downstream from the WWTPs was clearly demonstrated, but the correlations of the MECs with dilution factors were poor. The smallest rivers exhibited the largest maximum MECs and the widest ranges of MECs downstream from the wastewater discharge point. Three of the four tested models were conservative, as they showed higher PECs than the MECs in the rivers downstream from the WWTPs. However, the most detailed model underestimated the diclofenac concentrations.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-07-01

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

  13. Assessment of metallic mineral resources in the Humboldt River Basin, Northern Nevada, with a section on Platinum-Group-Element (PGE) Potential of the Humboldt Mafic Complex

    Science.gov (United States)

    Wallace, Alan R.; Ludington, Steve; Mihalasky, Mark J.; Peters, Stephen G.; Theodore, Ted G.; Ponce, David A.; John, David A.; and Berger, Byron R.; Zientek, Michael L.; Sidder, Gary B.; Zierenberg, Robert A.

    2004-01-01

    The Humboldt River Basin is an arid to semiarid, internally drained basin that covers approximately 43,000 km2 in northern Nevada. The basin contains a wide variety of metallic and nonmetallic mineral deposits and occurrences, and, at various times, the area has been one of the Nation's leading or important producers of gold, silver, copper, mercury, and tungsten. Nevada currently (2003) is the third largest producer of gold in the world and the largest producer of silver in the United States. Current exploration for additional mineral deposits focuses on many areas in northern Nevada, including the Humboldt River Basin.

  14. How to comprehensively evaluate river corridor conditions? A comparison of different biotic and morphological indices in northern Italy

    Science.gov (United States)

    Golfieri, Bruno; Surian, Nicola; Hardersen, Sönke; Maiolini, Bruno

    2016-04-01

    The assessment of river conditions is crucial for planning appropriate management actions. The European Water Framework Directive 2000/60/EC (WFD) requires the assessment of biological, physical-chemical and hydromorphological elements to define the ecological status of rivers. The WFD suggests the use of different bioindicators (i.e. benthic macroinvertebrates, diatoms, aquatic macrophytes and fish), the so called "biological quality elements" (BQEs). However, recent studies showed that BQEs-based indices have two main limitations: (i) their standard application is limited to flowing channels and (ii) they are not sensitive to hydromorphological alteration. Hydromorphological conditions are usually evaluated applying methods for physical habitat assessment (i.e. the River Habitat Survey or derived methods) that consist in site-scale inventories of river forms and anthropic structures. The lack of consideration of wider spatial (i.e. reach or catchment scale) and temporal scales (e.g. channel evolution over the last 50-100 years) make such methods inadequate for a sound diagnosis of morphological alterations. The Morphological Quality Index (MQI) and the dragonfly-based Odonate River Index (ORI) were developed in the recent years to overcome the above-mentioned limitations and to assess the condition of the whole river corridor (i.e. the channel and its adjacent floodplain) at reach scale. In this study we correlated the assessments of MQI, ORI and two BQEs-based biotic indices (i.e. STAR_ICMi for benthic macroinvertebrates and ICMi for diatoms) in 15 lowland river reaches in northern Italy. The selected reaches are characterized by a wide range of morphological degradation. MQI and ORI were highly correlated, probably because both methods work at reach scale and consider the integrity of the whole river corridor, either in terms of morphology or considering ecological aspects. In contrast, no significant relationships were found between MQI and ORI and the BQEs

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

    Science.gov (United States)

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

    2017-10-01

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

  16. Meltwater palaeohydrology of the Baker River basin (Chile/Argentina) during Late Pleistocene deglaciation of the Northern Patagonia Icefield

    Science.gov (United States)

    Thorndycraft, Varyl; Bendle, Jacob; Benito, Gerardo; Sancho, Carlos; Palmer, Adrian; Rodríguez, Xavier

    2016-04-01

    The Late Pleistocene deglaciation of the Northern Patagonia Icefield (NPI) was characterised by rapid ice sheet thinning and retreat, and the development of large proglacial lake systems characterised by continental scale drainage reversals. In this region, research has focused primarily on the identification of former ice-limits (e.g. moraine ridges) for geochronological analyses, with little attention given to the meltwater palaeohydrology of major river valleys. The Baker River catchment drains the majority of the eastern ice shed of the NPI, with a basin area of 29,000 km2 that includes the large transboundary lakes of General Carrera/Buenos Aires and Cochrane/Puerreydón. The Baker River valley is aligned north to south, crossing the east-west valleys of the main NPI outflow glaciers, and thus represents an important aspect of regional Late Pleistocene palaeogeography. The Baker River valley therefore has the potential to refine regional models of deglaciation through better understanding of relationships between glacier dynamics, ice dammed lakes and meltwater pathways. Here we present geomorphological mapping from the Atlantic-Pacific drainage divide (over 150 km east of the Cordillera) to the lower Baker valley, in order to reconstruct Late Pleistocene palaeohydrology. We provide new mapping of palaeolake shoreline elevations and evidence for glacial lake outburst flood (GLOF) pathways that require a re-evaluation of the currently accepted palaeogeographic models. For example, the palaeohydrological evidence does not support existing models of a unified Buenos Aires/Puerreydón mega-lake at ca. 400m elevation. We propose a relative chronology of palaeohydrological events that help refine the published moraine chronology derived from cosmogenic nuclide exposure dating. Controls on Late Pleistocene meltwater palaeohydrology of the Baker catchment are discussed, including the interplay of glacial processes and regional tectonics, in particular, dynamic

  17. Hydrogeology, groundwater levels, and generalized potentiometric-surface map of the Green River Basin lower Tertiary aquifer system, 2010–14, in the northern Green River structural basin

    Science.gov (United States)

    Bartos, Timothy T.; Hallberg, Laura L.; Miller, Cheryl E.

    2015-07-14

    In cooperation with the Bureau of Land Management, groundwater levels in wells located in the northern Green River Basin in Wyoming, an area of ongoing energy development, were measured by the U.S. Geological Survey from 2010 to 2014. The wells were completed in the uppermost aquifers of the Green River Basin lower Tertiary aquifer system, which is a complex regional aquifer system that provides water to most wells in the area. Except for near perennial streams, groundwater-level altitudes in most aquifers generally decreased with increasing depth, indicating a general downward potential for groundwater movement in the study area. Drilled depth of the wells was observed as a useful indicator of depth to groundwater such that deeper wells typically had a greater depth to groundwater. Comparison of a subset of wells included in this study that had historical groundwater levels that were measured during the 1960s and 1970s and again between 2012 and 2014 indicated that, overall, most of the wells showed a net decline in groundwater levels.

  18. Prevalence of Cryptosporidium and Giardia in the water resources of the Kuang River catchment, Northern Thailand.

    Science.gov (United States)

    Chuah, C Joon; Mukhaidin, Nabila; Choy, Seow Huey; Smith, Gavin J D; Mendenhall, Ian H; Lim, Yvonne A L; Ziegler, Alan D

    2016-08-15

    A catchment-scale investigation of the prevalence of Cryptosporidium and Giardia in the Kuang River Basin was carried out during the dry and rainy seasons. Water samples were collected from the Kuang River and its tributaries as well as a major irrigation canal at the study site. We also investigated the prevalence of gastrointestinal parasitic infection among dairy and beef cattle hosts. Cryptosporidium and/or Giardia were detected in all the rivers considered for this study, reflecting their ubiquity within the Kuang River Basin. The high prevalence of Cryptosporidium/Giardia in the upper Kuang River and Lai River is of a particular concern as both drain into the Mae Kuang Reservoir, a vital source of drinking-water to many local towns and villages at the research area. We did not, however, detected neither Cryptosporidium nor Giardia were in the irrigation canal. The frequency of Cryptosporidium/Giardia detection nearly doubled during the rainy season compared to the dry season, highlighting the importance of water as an agent of transport. In addition to the overland transport of these protozoa from their land sources (e.g. cattle manure, cess pits), Cryptosporidium/Giardia may also be re-suspended from the streambeds (a potentially important repository) into the water column of rivers during storm events. Faecal samples from dairy and beef cattle showed high infection rates from various intestinal parasites - 97% and 94%, respectively. However, Cryptosporidium and Giardia were only detected in beef cattle. The difference in management style between beef (freeranging) and dairy cattle (confined) may account for this disparity. Finally, phylogenetic analyses revealed that the Cryptosporidium/Giardia-positive samples contained C. ryanae (non-zoonotic) as well as Giardia intestinalis assemblages B (zoonotic) and E (non-zoonotic). With only basic water treatment facilities afforded to them, the communities of the rural area relying on these water supplies are

  19. Photophysiological and light absorption properties of phytoplankton communities in the river-dominated margin of the northern Gulf of Mexico

    Science.gov (United States)

    Chakraborty, Sumit; Lohrenz, Steven E.; Gundersen, Kjell

    2017-06-01

    Spatial and temporal variability in photophysiological properties of phytoplankton were examined in relationship to phytoplankton community composition in the river-dominated continental margin of the northern Gulf of Mexico (NGOM). Observations made during five research cruises in the NGOM included phytoplankton photosynthetic and optical properties and associated environmental conditions and phytoplankton community structure. Distinct patterns of spatial and temporal variability in photophysiological parameters were found for waters dominated by different phytoplankton groups. Photophysiological properties for locations associated with dominance by a particular group of phytoplankton showed evidence of photoacclimation as reflected by differences in light absorption and pigment characteristics in relationship to different light environments. The maximum rate of photosynthesis normalized to chlorophyll (PmaxB) was significantly higher for communities dominated (>60% biomass) by cyanobacteria + prochlorophyte (cyano + prochl). The initial slope of the photosynthesis-irradiance (P-E) curve normalized to chlorophyll (αB) was not clearly related to phytoplankton community structure and no significant differences were found in PmaxB and αB between different geographic regions. In contrast, maximum quantum yield of carbon fixation in photosynthesis (Φcmax) differed significantly between regions and was higher for diatom-dominated communities. Multiple linear regression models, specific for the different phytoplankton communities, using a combination of environmental and bio-optical proxies as predictor variables showed considerable promise for estimation of the photophysiological parameters on a regional scale. Such an approach may be utilized to develop size class-specific or phytoplankton group-specific primary productivity models for the NGOM.Plain Language SummaryThis study examined the relationships between phytoplankton community composition and associated

  20. Snow cover dynamics and hydrological regime of the Hunza River basin, Karakoram Range, Northern Pakistan

    Directory of Open Access Journals (Sweden)

    A. A. Tahir

    2011-07-01

    Full Text Available A major proportion of flow in the Indus River is contributed by its snow- and glacier-fed river catchments situated in the Himalaya, Karakoram and Hindukush ranges. It is therefore essential to understand the cryosphere dynamics in this area for water resource management. The MODIS MOD10A2 remote-sensing database of snow cover products from March 2000 to December 2009 was selected to analyse the snow cover changes in the Hunza River basin (the snow- and glacier-fed sub-catchment of the Indus River. A database of daily flows for the Hunza River at Dainyor Bridge over a period of 40 yr and climate data (precipitation and temperature for 10 yr from three meteorological stations within the catchment was made available to investigate the hydrological regime in the area. Analysis of remotely sensed cryosphere (snow and ice cover data during the last decade (2000–2009 suggest a rather slight expansion of cryosphere in the area in contrast to most of the regions in the world where glaciers are melting rapidly. This increase in snow cover may be the result of an increase in winter precipitation caused by westerly circulation. The impact of global warming is not effective because a large part of the basin area lies under high altitudes where the temperature remains negative throughout most of the year.

  1. Snow cover dynamics and hydrological regime of the Hunza River basin, Karakoram Range, Northern Pakistan

    Directory of Open Access Journals (Sweden)

    A. A. Tahir

    2011-03-01

    Full Text Available A major proportion of flow in the Indus River is contributed by its snow- and glacier-fed river catchments situated in the Himalaya, Karakoram and Hindukush ranges. It is therefore essential to understand the cryosphere dynamics in this area for water resource management. The MODIS MOD10A2 remote-sensing database of snow cover products from March 2000 to December 2009 was selected to analyse the snow cover changes in the Hunza River basin (the snow- and glacier-fed sub-catchment of the Indus River. A database of daily flows for the Hunza River at Dainyor Bridge over a period of 40 years and climate data (precipitation and temperature for 10 years from three meteorological stations within the catchment was made available to investigate the hydrological regime in the area. Analysis of remotely sensed cryosphere (snow and ice cover data showed a slight expansion of snow cover in the area in contrast to most of the regions in the world where glaciers are melting rapidly. This increase in snow cover may be the result of an increase in winter precipitation caused by westerly circulation. The impact of global warming is not effective because a large part of the basin area lies under high altitudes where the temperature remains negative throughout most of the year.

  2. Snow cover dynamics and hydrological regime of the Hunza River basin, Karakoram Range, Northern Pakistan

    Science.gov (United States)

    Tahir, A. A.; Chevallier, P.; Arnaud, Y.; Ahmad, B.

    2011-07-01

    A major proportion of flow in the Indus River is contributed by its snow- and glacier-fed river catchments situated in the Himalaya, Karakoram and Hindukush ranges. It is therefore essential to understand the cryosphere dynamics in this area for water resource management. The MODIS MOD10A2 remote-sensing database of snow cover products from March 2000 to December 2009 was selected to analyse the snow cover changes in the Hunza River basin (the snow- and glacier-fed sub-catchment of the Indus River). A database of daily flows for the Hunza River at Dainyor Bridge over a period of 40 yr and climate data (precipitation and temperature) for 10 yr from three meteorological stations within the catchment was made available to investigate the hydrological regime in the area. Analysis of remotely sensed cryosphere (snow and ice cover) data during the last decade (2000-2009) suggest a rather slight expansion of cryosphere in the area in contrast to most of the regions in the world where glaciers are melting rapidly. This increase in snow cover may be the result of an increase in winter precipitation caused by westerly circulation. The impact of global warming is not effective because a large part of the basin area lies under high altitudes where the temperature remains negative throughout most of the year.

  3. 800 years of watermills' operation on rivers of the Central and Northern Poland

    Science.gov (United States)

    Brykala, Dariusz

    2014-05-01

    Interdisciplinary research team composed of: a historian, ethnologist-conservation specialist, GIS software specialists, hydrologist and geomorphologist, take on the task of reconstruction of the cultural landscape of river valleys during the last 800 years. The aim of the research is temporal and spatial reconstruction of changes in development degree of rivers within the lower Vistula river basin. Temporal scope of research covers the period since the beginning of the 13th century to the beginning of the 21st century. Author presents the environmental and economical causes of watermills location's diversity. The study area comprises lower part of the Vistula river basin with a total area of about 39,500 sq km (20% of the total area of basin). The main source of research are cartographical and archival materials. Additionally there are conducted terrain studies (leveling, hydrometric measurements, inventory and catalog works of hydraulic structures). Its results will help to restore the size of the impoundment within the lower Vistula river basin over the last 800 years. The analysis of the collected materials proves that the water of the rivers used to be dammed up every 2-3 kilometres. Studies led to the reconstruction of the location, size as well as time span of about 1500 watermills. Natural hydrographical systems were modified very often with complicated mill stream systems. Such a situation lasted throughout centuries, even when the mills ceased to exist. These studies are the result of the scientific project funded by the National Science Centre (NCN - grant: UMO-2011/03/D/HS3/03631).

  4. Freshwater mussel, Velesunio angasi - a monitor for radium-226 pollution in the Alligator Rivers Region, Northern Territory

    Energy Technology Data Exchange (ETDEWEB)

    Davy, D.R.; Jeffree, R.A. (Australian Atomic Energy Commission Research Establishment, Lucas Heights. Environmental Science Div.)

    1984-10-01

    The state of knowledge of the biology and radioecology of the freshwater mussel, Velesunio angasi, is reviewed. The theoretical response is calculated, in terms of gross parameters suitable for monitoring purposes, for a range of predicted water contaminating events at the Ranger Uranium Mine site in the Alligator Rivers region of the Northern Territory. These results suggest that mussels would be useful biological monitors for events that lead to an increase in the Ra/Ca ratio for the receiving waters. Suitable measurement parameters are Ra:Ca tissue concentration regression and the microstructure of radium distribution within the mussel shell. On the basis of available field data for one event (enhanced erosion of pit borrow material into Georgetown waterhole during the 1980-81 wet season), which had no conventional water quality fingerprint, mussels were shown to be a suitable monitor of such events.

  5. Human-induced changes in the soil cover at the mouth of the Vistula River Cross-Cut (northern Poland

    Directory of Open Access Journals (Sweden)

    Hulisz Piotr

    2015-06-01

    Full Text Available The aim of this paper is to determine the impact of human activity on the soil formation at the mouth of the Vistula Cross-Cut (northern Poland. The detailed research was conducted in the test area (about 500 ha for which the soil map was created. The three major soil belts were distinguished, grouping the soils formed on marine, aeolian and technogenic sediments, deposited both naturally and anthropogenically as a result of the hydrotechnical works. Initial soils, arenosols, gleysols, brackish marsh soils and industrial soils predominate across the study area. Most of them were characterized by high spatial diversity and multi-layering. Their properties reflected varied dynamics of the local environment on both sides of the river channel, greatly enhanced by the human activity. Based of the obtained results, some proposals concerning arenosols, marsh soils and industrial soils for the Polish Soil Classification (2011 were presented.

  6. LDL (Landscape Digital Library) a Digital Photographic Database of a Case Study Area in the River Po Valley, Northern Italy

    CERN Document Server

    Papotti, D

    2001-01-01

    Landscapes are both a synthesis and an expression of national, regional and local cultural heritages. It is therefore very important to develop techniques aimed at cataloguing and archiving their forms. This paper discusses the LDL (Landscape Digital Library) project, a Web accessible database that can present the landscapes of a territory with documentary evidence in a new format and from a new perspective. The method was tested in a case study area of the river Po valley (Northern Italy). The LDL is based on a collection of photographs taken following a systematic grid of survey points identified through topographic cartography; the camera level is that of the human eye. This methodology leads to an innovative landscape archive that differs from surveys carried out through aerial photographs or campaigns aimed at selecting "relevant" points of interest. Further developments and possible uses of the LDL are also discussed.

  7. Seasonal meso- and microhabitat selection by the northern snakehead (Channa argus) in the Potomac river system

    Science.gov (United States)

    Lapointe, N.W.R.; Thorson, J.T.; Angermeier, P.L.

    2010-01-01

     The northern snakehead (Channa argus) is a large piscivorous fish that is invasive in eastern Europe and has recently been introduced in North America. We examined the seasonal habitat selection at meso- and microhabitat scales using radio-telemetry to increase understanding of the ecology of this species, which will help to inform management decisions. After the spawning season (postspawn season, September–November), northern snakeheads preferred offshore Eurasian water-milfoil (Myriophyllum spicatum) beds with shallow water (∼115 cm) and soft substrate. In the winter (November–April), these fish moved to deeper water (∼135 cm) with warmer temperatures, but habitat selection was weak at both scales. Northern snakeheads returned to shallower water (∼95 cm) in the prespawn season (April–June) and used milfoil and other cover. Habitat selection was the strongest at both meso- and microhabitat scales during the spawning season (June–September), when fish preferred macrophytes and cover in shallow water (∼88 cm). Our results help to identify habitats at the risk of invasion by northern snakeheads. We suggest that control efforts and future research focus on shallow waters, and take into consideration the seasonal habitat preferences.

  8. Application of a new hydraulic conductivity model to simulate rapid groundwater fluctuations in the Eel River watershed in Northern California

    Science.gov (United States)

    Vrettas, M. D.; Fung, I. Y.

    2015-12-01

    High-frequency multi-year observations of the water table at several wells in the Angelo Coast Range Reserve in the Eel River Watershed in northern California show rapid fluctuations, where the water table, some 10-15 meters below the surface, rises by as much as 1 meter in a day or two after the first storms of the rain season. The observations highlight preferential flow through weathered bedrock, which can store as much as 30% of the moisture in the column ("rock moisture"). This rapid transfer of moisture and storage at depth could have a significant impact on ecosystem dynamics and the water and energy budgets of the atmosphere on various time scales. Despite its high importance, preferential flow through weather bedrock is not routinely captured in most climate models. This work presents a new hydraulic conductivity parameterization that captures the preferential flow, with straightforward implementation into current global climate models. The hydraulic conductivity is represented as a product of the effective saturation (normalized water content) and a background hydraulic conductivity Kbkg, drawn from a depth dependent lognormal distribution. A unique feature of the parameterization is that the variance of hydraulic conductivity is large when there is little rock moisture, and decreases with increasing saturation, mimicking flow through fractures. The new method is applied to seven wells locations on a steep (35 degrees) hill-slope in the Eel River watershed in Northern California, for the duration of six years and estimates of the model parameters are provided by assimilating, into Richards' equation, measurements of precipitation [mm] and water table depths [m] at 30-minute time intervals. The simulation results show that the new approach yields a good agreement of the rapid rise of the observed water table at the tested well locations. Furthermore, the water stored in the weathered bedrock is estimated to be in the range between 32% and 41%, which could

  9. Interactive management of international river basins; Experiences in Northern America and Western Europe

    NARCIS (Netherlands)

    J.A. van Ast (Jacko)

    2000-01-01

    textabstractThis paper deals with the experiences of international water commissions with a more interactive way in dealing with society and water system. The first experiences with co-operation in international institutions between water managers already started many centuries ago. For the river Rh

  10. A method for distinguishing different water sources during flood events in river floodplains, northern Poland

    NARCIS (Netherlands)

    Chormanski, J.; Karalevich, J.; Kardel, I.; Okruszko, T.; Wassen, M.J.

    2010-01-01

    The Biebrza wetlands are located in an ice-marginal valley in northeastern Poland and cover some 195 000 hectares. The Biebrza river is not regulated, the valley is not reclaimed and still has marsh, fen and grassland vegetation whereas large scale human interventions in hydrology are absent. The mo

  11. Source identification of fine-grained suspended sediment in the Kharaa River basin, northern Mongolia.

    Science.gov (United States)

    Theuring, Philipp; Collins, Adrian L; Rode, Michael

    2015-09-01

    Fine sediment inputs into river systems can be a major source of nutrients and heavy metals and have a strong impact on water quality and ecosystem functions of rivers and lakes, including those in semiarid regions. However, little is known to date about the spatial distribution of sediment sources in most large scale river basins in Central Asia. Accordingly, a sediment source fingerprinting technique was used to assess the spatial sources of fine-grained (0.97) and were subsequently used for numerical mass balance modelling with uncertainty analysis. The contributions of the individual sub-catchment spatial sediment sources varied from 6.4% (the headwater sub-catchment of Sugnugur Gol) to 36.2% (the Kharaa II sub-catchment in the middle reaches of the study basin), generally showing higher contributions from the sub-catchments in the middle, rather than the upstream, portions of the study area. The importance of river bank erosion is shown to increase from upstream to midstream tributaries. The source tracing procedure provides results in reasonable accordance with previous findings in the study region and demonstrates the applicability and associated uncertainties of the approach for fine-grained sediment source investigation in large scale semi-arid catchments. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Evaluation of excessive lifetime cancer risk due to natural radioactivity in the rivers sediments of Northern Pakistan

    Directory of Open Access Journals (Sweden)

    Aziz Ahmed Qureshi

    2014-10-01

    Full Text Available Naturally occurring radionuclides 226Ra, 232Th and 40K present in the rivers sediments of Northern Pakistan were measured using HPGe γ-ray spectrometer to evaluate the radiation health hazard indices and excess lifetime cancer risk (ELCR. Average concentrations of 226Ra, 232Th and 40K in the sediments were found to be 50.66 ± 1.29, 70.15 ± 1.45 and 531.70 ± 5.45 Bq kg−1 respectively. Radium equivalent activity (190.89 Bq kg−1, outdoor external dose (87.47 nGy h−1, indoor external dose (165.39 nGy h−1, and total average annual effective dose (0.92 mSv were calculated. The hazard indices are higher than the world's average values. Total excess lifetime cancer risk (ELCR was found to be 3.21 × 10−3 which is relatively higher. Numerous cancer deaths are annually reported from the Northern areas of Pakistan, which may be related to high radioactivity in the area.

  13. Groundwater interaction with surface drains in the Ord River Irrigation Area, northern Australia: investigation by multiple methods

    Science.gov (United States)

    Smith, Anthony J.; Pollock, Daniel W.; Palmer, Duncan

    2010-08-01

    Following 35 years of persistent groundwater rise beneath northern Ivanhoe Plain in the Ord River Irrigation Area, northern Australia, the water table appears to have stabilized near the base of the irrigation surface-drain network. Hydrometric evidence indicates that intersection of the deepest surface drains by the rising water table simultaneously reduced aquifer recharge from surface-water infiltration and increased aquifer discharge by groundwater exfiltration. Water-table analysis supports the working hypothesis that the largest irrigation drain D4 on north Ivanhoe Plain has been receiving a significant amount of groundwater discharge since the mid-1990s. The rate of groundwater discharge to surface drains on north Ivanhoe Plain was estimated to be around 15-20 million (M)L/day based on groundwater-flow modelling. Groundwater tracing using radon and electrical conductivity indicated that groundwater discharge to drain D4 was ˜6-12 ML/day in August 2007. The rate of groundwater discharge was significantly larger where the drain traverses a very-permeable sand and gravel palaeochannel. Relatively modest exfiltration rates of order of magnitude tens to hundreds of mm/day into the drain were estimated to mitigate 0.5 m/year groundwater accretion for a land area of order of magnitude hundreds to thousands of ha.

  14. Ectoparasites community in Satanoperca jurupari (Cichlidae from the Jari River, a tributary from Amazon River in Northern Brazil

    Directory of Open Access Journals (Sweden)

    Marcos Sidney Brito de Oliveira

    Full Text Available Abstract The aim of this study was to investigate the gills parasites in Satanoperca jurupari from the Jari River, state of Amapá, in eastern Amazon (Brazil. The gills of 100% of the hosts were parasitized by Ichthyophthirius multifiliis (Protozoa, Sciadicleithrum juruparii (Monogenoidea Genarchella genarchella, Posthodiplostomum sp. (Digenea Ergasilus coatiarus and Argulus multicolor (Crustacea, and a total of 27,043 parasites were collected. However, the dominance was of I. multifiliis and there was aggregated dispersion of parasites with greater discrepancy for S. juruparii and A. multicolor. Low species richness of parasites (3.1 ± 1.1, low Brillouin diversity index (0.27 ± 0.23, low evenness (0.16 ± 0.13 and high dominance of Berger-Parker (0.88 ± 0.15 were found. The community of parasites in S. jurupari was characterized by low species richness, low diversity and low evenness, with high prevalence and low abundance. The size of host did not have any influence on the parasites community, but the host behavior and availability of infective stages of the parasites were factors structuring the community of ectoparasites found here.

  15. Reconstructing streamflow variation of the Baker River from tree-rings in Northern Patagonia since 1765

    Science.gov (United States)

    Lara, Antonio; Bahamondez, Alejandra; González-Reyes, Alvaro; Muñoz, Ariel A.; Cuq, Emilio; Ruiz-Gómez, Carolina

    2015-10-01

    The understanding of the long-term variation of large rivers streamflow with a high economic and social relevance is necessary in order to improve the planning and management of water resources in different regions of the world. The Baker River has the highest mean discharge of those draining both slopes of the Andes South of 20°S and it is among the six rivers with the highest mean streamflow in the Pacific domain of South America (1100 m3 s-1 at its outlet). It drains an international basin of 29,000 km2 shared by Chile and Argentina and has a high ecologic and economic value including conservation, tourism, recreational fishing, and projected hydropower. This study reconstructs the austral summer - early fall (January-April) streamflow for the Baker River from Nothofagus pumilio tree-rings for the period 1765-2004. Summer streamflow represents 45.2% of the annual discharge. The regression model for the period (1961-2004) explains 54% of the variance of the Baker River streamflow (R2adj = 0.54). The most significant temporal pattern in the record is the sustained decline since the 1980s (τ = -0.633, p = 1.0144 ∗ 10-5 for the 1985-2004 period), which is unprecedented since 1765. The Correlation of the Baker streamflow with the November-April observed Southern Annular Mode (SAM) is significant (1961-2004, r = -0.55, p development of new tree-ring reconstructions to increase the geographic range and to cover the last 1000 or more years using long-lived species (e.g. Fitzroya cupressoides and Pilgerodendron uviferum). Expanding the network and quality of instrumental weather, streamflow and other monitoring stations as well as the study and modeling of the complex hydrological processes in the Baker basin are necessary. This should be the basis for planning, policy design and decision making regarding water resources in the Baker basin.

  16. Channel response to extreme floods: Insights on controlling factors from six mountain rivers in northern Apennines, Italy

    Science.gov (United States)

    Surian, Nicola; Righini, Margherita; Lucía, Ana; Nardi, Laura; Amponsah, William; Benvenuti, Marco; Borga, Marco; Cavalli, Marco; Comiti, Francesco; Marchi, Lorenzo; Rinaldi, Massimo; Viero, Alessia

    2016-11-01

    This work addresses the geomorphic response of mountain rivers to extreme floods, exploring the relationships between morphological changes and controlling factors. The research was conducted on six tributaries of the Magra River (northern Apennines, Italy) whose catchments were affected by an extreme flood (estimated recurrence interval > 100 years in most of the basins) on 25 October 2011. An integrated approach was deployed to study this flood, including (i) analysis of channel width changes by comparing aerial photographs taken before and after the flood, (ii) estimate of peak discharges in ungauged streams, (iii) detailed mapping of landslides and analysis of their connectivity with the channel network. Channel widening occurred in 35 reaches out of 39. In reaches with channel slope hydraulic variables alone are not sufficient to satisfactorily explain the channel response to extreme floods, and inclusion of other factors such as lateral confinement is needed to increase explanatory capability of regression models. Concerning hydraulic variables, this study showed that the degree of channel widening is more strongly related to unit stream power calculated based on pre-flood channel width than to cross-sectional stream power and to unit stream power calculated with post-flood channel width. This could suggest that most width changes occurred after the flood peak. Finally, in terms of hazard, it is crucial to document the type and magnitude of channel changes, to identify controlling factors, and most importantly, to develop tools enabling us to predict where major geomorphic changes occur during an extreme flood.

  17. Mortality of silver eel (Anguilla anguilla migrating downstream through a small hydroelectric plant on the Drawa River in northern Poland

    Directory of Open Access Journals (Sweden)

    Dębowski Piotr

    2016-06-01

    Full Text Available The European eel, Anguilla anguilla L., is an endangered species. Barriers to its downstream spawning migration are one of the greatest threats this species faces. There are hundreds of hydroelectric plants (HEP on rivers in Poland (> 600, and thousands throughout Europe. Eel that pass through HEP turbines as they migrate downstream suffer high mortality, but this depends mainly on local and technical conditions. Silver eel mortality was estimated and the possibility of the fish bypassing the turbines was studied between November 2013 and June 2014 at a typical HEP in northern Poland. Two telemetry methods were used with 49 eel: passive integrated transponder (PIT system and acoustic telemetry. Fifty five percent of eel migrated downstream in fall 2013, soon after their release, and 45% migrated the next spring. The eel did not use the fish passes designed for upstream migration; thus, they were forced to go through the turbines, which resulted in 55% mortality. HEPs cause interruptions and delays in eel spawning migrations and are responsible for high eel mortality. This can make implementing an eel restitution plan difficult or even impossible in river systems with many barriers.

  18. Contrasting Holocene sedimentary geologies of lower Daly River, northern Australia, and lower Sepik-Ramu, Papua New Guinea

    Science.gov (United States)

    Chappell, John

    1993-03-01

    The estuarine plain of the macrotidal Daly River, in monsoonal northern Australia, is underlain by extensive mid-Holocene mangrove swamp sediments which accumulated during the last stages of Post-glacial sea-level rise. Sediment yield from the catchment is too low to account for the volume which accumulated during sea-level rise, and onshore transport is invoked. This is supported by radiocarbon ages and facies analysis of the transgressive sediment tract beneath the maximum flooding surface (MFS), and of the tract of vertical sedimentation which extends from the MFS to the surface of estuarine/fluvial transition (the EFT). The EFT occurred about 5000 to 6000 BP throughout the estuarine plain. A contrasting situation exists in the lowland Holocene basin of the microtidal Sepik and Ramu rivers in Papua New Guinea, which derive sediment from highly tectonic catchments. A tectonic basin, which was a shallow brackish inland sea after Post-glacial transgression, is separated by a low divide from a deltaic plain. Progradation of the deltaic plain commenced about 3500 BP after regressive sedimentation eclipsed the inland sea in the tectonic basin. Contrasting organic facies, mangrove in the Daly and freshwater swamp deposits in the Sepik-Ramu, highlight differences between facies models of the two systems. Differences between fluvio-tidal regimes are reflected by the EFT, which is synchronous in the Daly and diachronous in the Sepik-Ramu, and possibly by the MFS which is diachronous in the Daly and may be synchronous in the Sepik-Ramu.

  19. "Projeto Rios" (Rivers Project) a methodology of classroom of the future (northern Portugal)

    Science.gov (United States)

    Almeida, Ana

    2013-04-01

    The rivers and the surrounding land drained by them are very important wildlife habitats. The water itself provides the environment for plants and animals, while the banks and nearby land support creatures such as otters, water lizards, dragonflies and a variety of water-loving plants. Using a different teaching strategy, on the latest three years, students of the eighth grade of the EB 2.3 Agrela school have been implementing the project "Nós e o Leça" (We and the river Leça). This initiative is part of a nationwide project in Portugal, the "Projeto Rios", which is a tool that aims the adoption and monitoring of a 500 meter river section, promoting society's awareness for the problems and the need of protection and recovery of the riparian systems. These students adopted a section of the Leça River, which is the one that is passing nearby our school. Throughout the mentioned school years, the children made field trips for characterization, knowledge and observation of some happenings on the section adopted, with the aid of a complete kit of materials (galoshes, loupes, tweezers, trays, fishnets, tape measure, tape of pH...). Token fields for identifications of plants and animals and specific data sheets/questionnaires, were also used and fulfilled. While in the river, it is done the collection of macro invertebrates to conclude about the water quality of the section under study. Youth also detect disturbances in the balance of the riverine ecosystem, either naturally occurring or of human origin. Aiming the sustained development and the citizenship education, the students performed a final action for improvement, which consisted in the uprooting of an invasive plant, in this case "the herb-of-fortune" and also gathering the "trash" founded along the adopted stretch of the river. Back to the classroom, we selected photographs and the collected data is treated and discussed to produce information (summaries, reports, tables, charts,...) which will be published

  20. Paleoenvironmental and source rock assessment of black shales of Pennsylvanian Age, Powder River and northern Denver basins

    Energy Technology Data Exchange (ETDEWEB)

    Clayton, J.L.; King, J.D.; Lubeck, C.M.; Leventhal, J.S.; Daws, T.A.

    1988-07-01

    Thin Middle Pennsylvanian (Desmoinesian) organic-rich black shales (cumulative thickness < 50 ft) underlie much of the northern Denver basin and southeastern Powder River basin. In the Powder River basin, these shales are part of the middle member of the Minnelusa Formation. During Desmoinesian time, the present area of the southeastern Powder River basin and Nebraska was a shallow, at times highly saline, restricted sea. In contrast, in the present area of northeastern Colorado, black shales were deposited in a marine environment with normal salinity that was probably continuous with the Mid-Continent Pennsylvanian sea. Assessment of the paleoenvironment has been carried out using organic geochemical parameters. Shales deposited in the restricted basin setting contain abundant porphyrins (25,000-30,000 ppm relative to total extractable organic matter) and significant quantities of aryl isoprenoids. The aryl isoprenoid compounds (1) are evidence for the presence of the sulfur bacteria families Chlorobiaceae and possibly Chromatiaceae and (2) indicate that euxinic conditions existed in the water column. High ratios of sulfur to carbon in the shales support this interpretation. In contrast, extracts from black shale in the normal sea to the south contain lower porphyrin concentrations (generally less than 1000 ppm) and aryl isoprenoids are minor constituents or are absent. Sulfur/carbon ratios in these latter shales are similar to those observed for normal marine shales (that is, not euxinic conditions). Other paleoenvironmental indicators (sterane composition, alkane distribution) are consistent with these observations. Bulk organic matter in the black shales from both environments is type II and has good source potential for generation of liquid hydrocarbons during catagenesis. Pyrolysis yields of 50 kg/MT (50,000 ppm) are common, and in some shales, yield is 100 kg/MT (100,000 ppm).

  1. Distribution, densities, and ecology of Siberian cranes in the Khroma River region of northern Yakutia in northeastern Russia

    Science.gov (United States)

    Bysykatova, Inga P.; Krapu, Gary L.; Germogenov, Nicolai I.; Buhl, Deborah A.; Aborn, David

    2014-01-01

    The Siberian crane (Grus leucogeranus) is the third rarest crane species in the world with a breeding range now centered on 3 core areas and a buffer zone in the arctic of northern Yakutia in northeastern Russia. During 16 July-2 August 2009, we undertook ground surveys within the Khroma River core breeding area, surrounding buffer zone, and lands lying to the west of the known rbeeding range to estimate densities and determine habitat use and social status of Siberian cranes. A total of 142 Siberian cranes were sighted (including 55 pairs) at 54 locations with 32 cranes (including 13 pairs) sighted outside the currently known breeding range in the lower drainages of the Syalakh and Syuryuktyakh Rivers. After adjusting for a probability of detection of 0.484 (95% CI = 0.281-0.833), Siberian crane densities in the Khroma core area and the buffer zone averaged 0.0921 cranes/km2 and 0.0363 cranes/km2, respectively. A majority of cranes (n = 93 [65%]) occurred in complexes of large basin wetlands, with use centered in those having extensive beds of pendant grass (Arctophila fulva). Of the 142 cranes seen, 110 (77%) were paired, 21 (15%) were singles, and 11 (8%) were in groups of 3-5. The Khroma core supports 1 of 2 large concentrations of breeding Siberian cranes remaining in the wild; therefore, we recommend that consideration be given to designating a nature reserve that would encompass the Khroma core, adjacent buffer zone, and lands to the west (including coastal tundra areas along the lower drainages of the Syalah and Syuryuktyah Rivers). Further research is needed to gain additional insight into Siberian crane distribution and numbers on lands beyond the currently delineated western boundary of the Siberian crane breeding range in the Ust-Yana District of northern Yakutia. Important gaps remain in information needed to effectively guide conservation efforts for the Eastern Population, and recent advances in remote tracking technology offer potential

  2. beta (+)-Thalassaemia in the Po river delta region (northern Italy): genotype and beta globin synthesis.

    Science.gov (United States)

    Del Senno, L; Pirastu, M; Barbieri, R; Bernardi, F; Buzzoni, D; Marchetti, G; Perrotta, C; Vullo, C; Kan, Y W; Conconi, F

    1985-01-01

    Six beta(+)-thalassaemic patients from the Po river delta region have been studied. Using synthetic oligonucleotides as specific hybridisation probes, the beta(+) IVS I mutation (G----A at position 108) was demonstrated. This lesion and the enzyme polymorphism pattern in the subjects examined are the same as have been described for other Mediterranean beta(+)-thalassaemias. Antenatal diagnosis through DNA analysis of beta(+)-thalassaemia is therefore possible. The production of beta globin in a beta(+), homozygote and in a beta (+), beta(0) 39 (nonsense mutation at codon 39) double heterozygote is approximately 20% and 10% respectively of total non-alpha globin synthesis. Despite some overlapping of the results, similar beta globin synthesis levels have been obtained in 43 beta(+)-thalassaemia patients. This suggests that in the Po river delta region the most common thalassaemic genes are beta(0) 39 and beta(+) IVS I. Images PMID:2580095

  3. End-member river water composition in the acidified Adirondack Region, Northern New York, USA

    Directory of Open Access Journals (Sweden)

    Jeffrey R. Chiarenzelli

    2014-11-01

    New hydrological insights for the region: Samples collected during average discharge volumes documented chemical gradients corresponding to bedrock spatial distribution. These trends were muted during both stormflow and baseflow, and imply that other factors influence water chemistry during high and low-flow events. Our study documents an example of event river chemistry responding less to extremes of flow or variation in underlying geology than anticipated. During the stormflow sampling one sample had elevated specific conductance (160.4 μS cm−1 and pH (8.21. This data, anomalous geochemistry, and images from Google Earth suggest that the river chemistry is sporadically impacted by discharge from a dolostone quarry located 6 km upstream during runoff events.

  4. Holocene evolution of the Song Hong (Red River) delta system, northern Vietnam

    Science.gov (United States)

    Tanabe, Susumu; Saito, Yoshiki; Lan Vu, Quang; Hanebuth, Till J. J.; Lan Ngo, Quang; Kitamura, Akihisa

    2006-05-01

    The Song Hong (Red River) delta, located on the western coast of the Gulf of Bac Bo (Tonkin) in the South China Sea, formed as a result of the Song Hong sediment discharge throughout the Holocene. The river's sedimentary basin upstream from the delta plain is not large. The delta plain comprises emerged tidal/mangrove flats formed during the sea-level highstand at + 2-3 m (6-4 cal. kyr BP) and a beach-ridge strandplain, with straight-to-lobate beach ridges, on the landward and seaward sides of the delta plain, respectively. The delta affords us the opportunity to examine river-mouth morphodynamics comprehensively in relation to sediment discharge and sea-level changes. In this paper, we describe the Holocene evolution of the Song Hong delta system and the river-mouth morphodynamics on the basis of seven sediment cores, each 30-70 m long, taken from the delta plain during 1999-2001 and 101 radiocarbon dates obtained from the core sediments. Sediments from the seven cores, consisting of incised-valley fills since the last glacial maximum, can be divided, in ascending order, into fluvial sediments composed of gravelly sand and mottled clay, tide-influenced estuarine sediments containing shell and wood fragments, and deltaic sediments composed of tide-influenced sand and mud deposits, in which the contents of sand and wood fragments increase upward. By applying sequence stratigraphic concepts, a transgressive surface can be identified at the gravelly sand-mottled clay boundary, and the maximum flooding surface can be identified at the estuarine-deltaic sediments boundary. The lowstand systems tract, transgressive systems tract, and highstand systems tract record ˜15, 15-9, and 9-0 cal. kyr BP, respectively. During the past 9 kyr, the majority of the sediment discharged by the Song Hong accumulated in the incised valley and enhanced progradation at the river mouth. The river mouth prograded from the bay head toward the gulf, and its morphology changed from funnel

  5. Environmental Impact Study of the Northern Section of the Upper Mississippi River. Pool 8.

    Science.gov (United States)

    1973-11-01

    due to sand dune formation. These terrace provide a suitable place for people to settle and populate. However, outwash from these terraces tends to...income than is industrial activity and relates mainly to leisure-time activities of people using the Mississippi River for recreational purposes...burial mounds, historical battlegrounds or buildings, or existing settlements of 22 ethnic groups such as Amish communities. Because of the difficulty of

  6. beta (+)-Thalassaemia in the Po river delta region (northern Italy): genotype and beta globin synthesis.

    OpenAIRE

    del Senno, L; Pirastu, M; Barbieri, R.; De Bernardi, F.; Buzzoni, D; Marchetti, G.; Perrotta, C; Vullo, C; Kan, Y W; Conconi, F

    1985-01-01

    Six beta(+)-thalassaemic patients from the Po river delta region have been studied. Using synthetic oligonucleotides as specific hybridisation probes, the beta(+) IVS I mutation (G----A at position 108) was demonstrated. This lesion and the enzyme polymorphism pattern in the subjects examined are the same as have been described for other Mediterranean beta(+)-thalassaemias. Antenatal diagnosis through DNA analysis of beta(+)-thalassaemia is therefore possible. The production of beta globin in...

  7. Environmental Impact Study of the Northern Section of the Upper Mississippi River. Pool 7.

    Science.gov (United States)

    1973-11-01

    are for similar community situations in Western Wisconsin (Curtis, 1971). Algae Members of all classes and virtually all common orders of algae are...checklist of algae collected from Navigation Pool No. 7, Upper Mississippi River, 1970-1971. CIILOROPIIYTA Class Chlorophyceae Order Volvocales Family...Marssoniella elegans Miroysti sp.uc Mecrcsteia spau. Order Hormogonales Family Oscil1la Loriaceae Oscillatoria sp. Spirulina laxa Family Nostocaceae

  8. Cadmium concentration in three species of freshwater fishes from Keuretoe River, Northern Aceh, Indonesia

    OpenAIRE

    Muhammad A. Sarong; Abdul L. Mawardi; Muhammad Adlim; Zainal A.Muchlisin

    2013-01-01

    The objectives of present study was to evaluate cadmium (Cd) concentration in some freshwater fishes found in Keuretoe Rivers and to determine the most effective freshwater fishes (Osphronemus goramy, Anguilla marmorata and Hemibagrus nemurus) in accumulating of cadmium. A total of three sampling locations were determined using the purposive of random sampling. A total of three individual fishes at every sampling location were collected, the tissues were processed for Atomic ...

  9. Report on the Predation Index, Predator Control Fisheries, and Program Evaluation for the Columbia River Basin Experimental Northern Pikeminnow Management Program, 2008 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Porter, Russell [Pacific States Marine Fisheries Commission].

    2009-09-10

    This report presents results for year seventeen in the basin-wide Experimental Northern Pikeminnow Management Program to harvest northern pikeminnow1 (Ptychocheilus oregonensis) in the Columbia and Snake Rivers. This program was started in an effort to reduce predation by northern pikeminnow on juvenile salmonids during their emigration from natal streams to the ocean. Earlier work in the Columbia River Basin suggested predation by northern pikeminnow on juvenile salmonids might account for most of the 10-20% mortality juvenile salmonids experience in each of eight Columbia River and Snake River reservoirs. Modeling simulations based on work in John Day Reservoir from 1982 through 1988 indicated that, if predator-size northern pikeminnow were exploited at a 10-20% rate, the resulting restructuring of their population could reduce their predation on juvenile salmonids by 50%. To test this hypothesis, we implemented a sport-reward angling fishery and a commercial longline fishery in the John Day Pool in 1990. We also conducted an angling fishery in areas inaccessible to the public at four dams on the mainstem Columbia River and at Ice Harbor Dam on the Snake River. Based on the success of these limited efforts, we implemented three test fisheries on a system-wide scale in 1991 - a tribal longline fishery above Bonneville Dam, a sport-reward fishery, and a dam-angling fishery. Low catch of target fish and high cost of implementation resulted in discontinuation of the tribal longline fishery. However, the sport-reward and dam-angling fisheries were continued in 1992 and 1993. In 1992, we investigated the feasibility of implementing a commercial longline fishery in the Columbia River below Bonneville Dam and found that implementation of this fishery was also infeasible. Estimates of combined annual exploitation rates resulting from the sport-reward and dam-angling fisheries remained at the low end of our target range of 10-20%. This suggested the need for additional

  10. Sedimentological and geochronological evidences of anthropogenic impacts on river basins in the Northern Latium coastal area (Italy)

    Science.gov (United States)

    Piazzolla, Daniele; Paladini de Mendoza, Francesco; Scanu, Sergio; Marcelli, Marco

    2015-04-01

    In this work we aimed to compare sedimentological and geochronological data from three sediment core samples (MIG50, MRT50, and GRT50) taken in the Northern Latium (Italy) coastal area, at -50 m depth, to data regarding rainfall, river flows and the land use in the three most important hydrographic basins (Mignone, Marta and Fiora) and in the coastal area. Different trends of sediment mass accumulation rate (MAR) are detected in the three cores: a strongly increasing trend was identified in MIG50 and MRT50 cores while GRT50 doesn't show significant variation. Data from the sedimentological analysis of GRT50 core identify a progressive decrease in the sandy component, which declined from about 30% to the current level of 7% over the last 36 years, while MRT50 and MIG50 cores (mainly composed by pelitic fraction > 95%) showed slight variations of textural ratio between silt and clay. According to the general decrease of pluviometric trend observed in Italy, related to teleconnection pattern tendency (NAO), the statistical analysis of rain identified significative decrease only in the Fiora river basin, whereas in the other two locations the decrease was not as significant. Regarding the Fiora river flow, a significative decreasing trend of average flow is detected, while the flood regime remained unaffected over the past 30 years. The analysis of the land use shows that the human activities are increased of 6-10% over the available time steps (1990 - 2006) in Fiora and Mignone river basins, while the Marta river basin has a strong human impact since 1990 highligting more than 80% of artificial soil covering. The largest variation is observed on the Fiora basin (10%) where the antrhopic activities have expanded to an area of about 85 Km2. Moreover, in the last ten years a large beach nourishment in 2004 (570000 m3) and dredging activities in the early second half of 2000s (1000000 m3 moved) were performed in Marina di Tarquinia beach and in front of the Torrevaldaliga

  11. Water quality monitoring protocol for wadeable streams and rivers in the Northern Great Plains Network

    Science.gov (United States)

    Marcia H. Wilson,; Rowe, Barbara L.; Robert A. Gitzen,; Stephen K. Wilson,; Kara J. Paintner-Green,

    2014-01-01

    Preserving the national parks unimpaired for the enjoyment of future generations is a fundamental purpose of the National Park Service (NPS). To address growing concerns regarding the overall physical, chemical, and biological elements and processes of park ecosystems, the NPS implemented science-based management through “Vital Signs” monitoring in 270 national parks (NPS 2007). The Northern Great Plains Network (NGPN) is among the 32 National Park Service Networks participating in this monitoring effort. The NGPN will develop protocols over the next several years to determine the overall health or condition of resources within 13 parks located in Nebraska, North Dakota, South Dakota, and Wyoming.

  12. Carbonate chemistry dynamics and biological processes along a river-sea gradient (Gulf of Trieste, northern Adriatic Sea)

    Science.gov (United States)

    Ingrosso, Gianmarco; Giani, Michele; Cibic, Tamara; Karuza, Ana; Kralj, Martina; Del Negro, Paola

    2016-03-01

    In this paper we investigated, for two years and with a bi-monthly frequency, how physical, chemical, and biological processes affect the marine carbonate system in a coastal area characterized by high alkalinity riverine discharge (Gulf of Trieste, northern Adriatic Sea, Mediterranean Sea). By combining synoptic measurements of the carbonate system with in situ determinations of the primary production (14C incorporation technique) and secondary prokaryotic carbon production (3H-leucine incorporation) along a river-sea gradient, we showed that the conservative mixing between river endmember and off-shore waters was the main driver of the dissolved inorganic carbon (DIC) distribution and seasonal variation. However, during spring and summer seasons also the influence of biological uptake and release of DIC was significant. In the surface water of June 2012, the spreading and persistence of nutrient-rich freshwater stimulated the primary production (3.21 μg C L- 1 h- 1) and net biological DIC decrease (- 100 μmol kg- 1), reducing the dissolved CO2 concentration and increasing the pHT. Below the pycnocline of August 2012, instead, an elevated bacterial carbon production rate (0.92 μg C L- 1 h- 1) was related with net DIC increase (92 μmol kg- 1), low dissolved oxygen concentration, and strong pHT reduction, suggesting the predominance of bacterial heterotrophic respiration over primary production. The flux of carbon dioxide estimated at the air-sea interface exerted a low influence on the seasonal variation of the carbonate system. A complex temporal and spatial dynamic of the air-sea CO2 exchange was also detected, due to the combined effects of seawater temperature, river discharge, and water circulation. On annual scale the system was a sink of atmospheric CO2. However, in summer and during elevated riverine discharges, the area close to the river's mouth acted as a source of carbon dioxide. Also the wind speed was crucial in controlling the air-sea CO2

  13. Merits and Limits of Ecosystem Protection for Conserving Wild Salmon in a Northern Coastal British Columbia River

    Directory of Open Access Journals (Sweden)

    Aaron C. Hill

    2010-06-01

    Full Text Available Loss and degradation of freshwater habitat reduces the ability of wild salmon populations to endure other anthropogenic stressors such as climate change, harvest, and interactions with artificially propagated fishes. Preservation of pristine salmon rivers has thus been advocated as a cost-effective way of sustaining wild Pacific salmon populations. We examine the value of freshwater habitat protection in conserving salmon and fostering resilience in the Kitlope watershed in northern coastal British Columbia - a large (3186 km2 and undeveloped temperate rainforest ecosystem with legislated protected status. In comparison with other pristine Pacific Rim salmon rivers we studied, the Kitlope is characterized by abundant and complex habitats for salmon that should contribute to high resilience. However, biological productivity in this system is constrained by naturally cold, light limited, ultra-oligotrophic growing conditions; and the mean (± SD density of river-rearing salmonids is currently low (0.32 ± 0.27 fish per square meter; n = 36 compared to our other four study rivers (grand mean = 2.55 ± 2.98 fish per square meter; n = 224. Existing data and traditional ecological knowledge suggest that current returns of adult salmon to the Kitlope, particularly sockeye, are declining or depressed relative to historic levels. This poor stock status - presumably owing to unfavorable conditions in the marine environment and ongoing harvest in coastal mixed-stock fisheries - reduces the salmon-mediated transfer of marine-derived nutrients and energy to the system's nutrient-poor aquatic and terrestrial food webs. In fact, Kitlope Lake sediments and riparian tree leaves had marine nitrogen signatures (δ15N among the lowest recorded in a salmon ecosystem. The protection of the Kitlope watershed is undoubtedly a conservation success story. However, "salmon strongholds" of pristine watersheds may not adequately sustain salmon populations and foster

  14. Fine-grained suspended sediment source identification for the Kharaa River basin, northern Mongolia

    Science.gov (United States)

    Rode, Michael; Theuring, Philipp; Collins, Adrian L.

    2015-04-01

    Fine sediment inputs into river systems can be a major source of nutrients and heavy metals and have a strong impact on the water quality and ecosystem functions of rivers and lakes, including those in semiarid regions. However, little is known to date about the spatial distribution of sediment sources in most large scale river basins in Central Asia. Accordingly, a sediment source fingerprinting technique was used to assess the spatial sources of fine-grained (water flows, to collect an overall total of 900 sediment samples. The work used a statistical approach for sediment source discrimination with geochemical composite fingerprints based on a new Genetic Algorithm (GA)-driven Discriminant Function Analysis, the Kruskal-Wallis H-test and Principal Component Analysis. The composite fingerprints were subsequently used for numerical mass balance modelling with uncertainty analysis. The contributions of the individual sub-catchment spatial sediment sources varied from 6.4% (the headwater sub-catchment of Sugnugur Gol) to 36.2% (the Kharaa II sub-catchment in the middle reaches of the study basin) with the pattern generally showing higher contributions from the sub-catchments in the middle, rather than the upstream, portions of the study area. The importance of riverbank erosion was shown to increase from upstream to midstream tributaries. The source tracing procedure provides results in reasonable accordance with previous findings in the study region and demonstrates the general applicability and associated uncertainties of an approach for fine-grained sediment source investigation in large scale semi-arid catchments. The combined application of source fingerprinting and catchment modelling approaches can be used to assess whether tracing estimates are credible and in combination such approaches provide a basis for making sediment source apportionment more compelling to catchment stakeholders and managers.

  15. Extraction of geoid heights from shipborne GNSS measurements along the Weser River in northern Germany

    Science.gov (United States)

    Lavrov, D.; Even-Tzur, G.; Reinking, J.

    2015-11-01

    In-land geoid models rely on several measuring techniques. The quality of those models is directly related to the spatial resolution of the measurement data. Occasionally, a local geoid model does not cover the coastal area at all and a local marine geoid simply does not exist. ShipborneGNSS measurementsmay provide away of overcoming this problem in coastal areas. However, several corrections to the raw measurements must be applied in order to account for systematic effects induced by ship dynamics and other static and dynamic impacts from tides, atmospheric pressure or wind stress. This paper presents the theoretical background for the method and the results of a case study in the estuary of the Weser River in Germany. A series of GNSS measurements were carried out aboard a ship and the approximate geoid height along the river was derived. For accuracy assessments of this method, the resultswere compared to the German Combined QuasiGeoid 2011 (GCG2011). The results are very promising and indicate the ability to extract geoid heights from shipborne GNSS measurements.

  16. Cadmium concentration in three species of freshwater fishes from Keuretoe River, Northern Aceh, Indonesia

    Directory of Open Access Journals (Sweden)

    Muhammad A. Sarong

    2013-09-01

    Full Text Available The objectives of present study was to evaluate cadmium (Cd concentration in some freshwater fishes found in Keuretoe Rivers and to determine the most effective freshwater fishes (Osphronemus goramy, Anguilla marmorata and Hemibagrus nemurus in accumulating of cadmium. A total of three sampling locations were determined using the purposive of random sampling. A total of three individual fishes at every sampling location were collected, the tissues were processed for Atomic Absorption Spectrophotometry (AAS and data were analyzed by Anova followed by Duncan multiple range test. The result revealed that the cadmium concentration ranges between 0.0064 ppm and 0.0260 ppm. Anova test showed that the sampling locations did not significantly affect the cadmium accumulation in fishes, but the fish species gave significantly effect on the cadmium accumulation in their tissue. The Duncan test showed that high cadmium accumulation was found in gourami at Station 2 and in mottled eel at Station 1, the concentrations were significantly different from Cd content in bagrid catfish at all sampling locations. The higher of cadmium pollution was recorded in Station 3 and gourami accumulated higher cadmium than other fishes studied. Keuretoe River is contaminated with cadmium and the fishes should not be consumed.

  17. Mercury Fate and Transport in Hunza River Watershed, Northern Areas, Pakistan

    Science.gov (United States)

    Biber, K.; Khan, S. D.; Shah, M. T.

    2012-12-01

    Due to the highly mobile nature of mercury, it is considered to be a global environmental pollutant that is being distributed in the atmosphere, lithosphere and hydrosphere. Mercury's biogeochemical transfer between different compartments in the environment is complex and not known thoroughly. However, the importance of fate and transport of mercury in surface waters must be recognized for the well-being of people who drink or consume fish from contaminated waters. Using mercury in pan amalgamation for the extraction of gold from stream deposits along Indus and Gilgit Rivers in Pakistan is being practiced for many decades. Pan amalgamation in the small-scale gold panning and extraction (GPE) activities are known to be releasing significant amount of mercury to the environment due to inappropriate smelting practices. Analysis of 1372 stream sediments along Indus, Gilgit and Hunza Rivers showed that riverbank sediments upstream of Hunza and Gilgit Rivers are highly contaminated with mercury. From a data range of 4 to 2200 ppb, a total of 24 anomalous sites (having a concentration of more than 100 ppb) have been identified. These anomalies showed comparable results with US gold mine dump samples from mine sites existed until 1970s. In June 2011, 37 surface water samples were collected from Hunza River and its tributaries. Sample collection, preservation, storage and analysis were done as per EPA 1631 method. Samples were analyzed in terms of dissolved and particulate bound mercury content in the water. In these samples dissolved mercury concentration range from 5.10 ppt to 25.25 ppt, whereas, particulate bound mercury concentration varies between 4.85 ppb to 154.62 ppb. Total suspended solids were measured for each sampling site, in addition, field parameters, such as electrical conductivity, pH and temperature were measured in situ. During the field trip, many GPE sites were observed. First-hand observational data of the panning, washing, mercury amalgamation and

  18. Three decadal inputs of total organic carbon from four major coastal river basins to the summer hypoxic zone of the Northern Gulf of Mexico.

    Science.gov (United States)

    He, Songjie; Xu, Y Jun

    2015-01-15

    This study investigated long-term (1980-2009) yields and variability of total organic carbon (TOC) from four major coastal rivers in Louisiana entering the Northern Gulf of Mexico where a large-area summer hypoxic zone has been occurring since the middle 1980s. Two of these rivers drain agriculture-intensive (>40%) watersheds, while the other two rivers drain forest-pasture dominated (>50%) watersheds. The study found that these rivers discharged a total of 13.0×10(4)t TOC annually, fluctuating from 5.9×10(4) to 22.8×10(4)t. Seasonally, the rivers showed high TOC yield during the winter and early spring months, corresponding to the seasonal trend of river discharge. While river hydrology controlled TOC yields, land use has played an important role in fluxes, seasonal variations, and characteristics of TOC. The findings fill in a critical information gap of quantity and quality of organic carbon transport from coastal watersheds to one of the world's largest summer hypoxic zones.

  19. Environmental assessment and viable interdependence: the Great Whale River case in northern Quebec (First Nations)

    Energy Technology Data Exchange (ETDEWEB)

    Mulvihill, P. R.

    1997-12-31

    This study is based on the belief that environmental assessment (EA) can be supportive of viable interdependence between regions and cultures. The central focus is on the scoping stage of the EA conducted for the proposed Great Whale hydroelectric project in northern Quebec. The evaluative framework consists of 16 criteria divided into three interrelated categories, i.e. substantive, general process-oriented and specific process-oriented. The specific process-oriented criteria constitute the primary analytical focus and are the subject of five separate sub-analysis, which reveal various strengths and weaknesses in the performance of the case study. It was concluded that environmental assessment in an intercultural setting is largely within the control of EA panels and the key shortcoming of the process, namely the lack of dialogue between the proponents and the intervenors, could be addressed by making public hearings more dynamic and interactive.

  20. Geochemical characterization and biomonitoring of reclaimed soils in the Po River Delta (Northern Italy): implications for the agricultural activities.

    Science.gov (United States)

    Di Giuseppe, Dario; Bianchini, Gianluca; Vittori Antisari, Livia; Martucci, Annalisa; Natali, Claudio; Beccaluva, Luigi

    2014-05-01

    This geochemical study is focused on the easternmost part of the Po River alluvial plain in Northern Italy, which is interested by widespread agricultural activities, investigating a reclaimed sector of the Province of Ferrara, known as "Valle del Mezzano" (Mezzano Low Land, hereafter reported as MLL) characterized by peat-rich soils. The chemical-mineralogical characterization of these reclaimed soils is important to compare the local geochemical backgrounds with those recorded in other sectors of the River Po plain and to monitor if the observed concentration exceeds critical thresholds. The reported analyses include (a) measurement of the soil salinity, (b) nutrient evaluation, (c) major and trace element concentrations carried out on bulk soils, (d) tests of metal extraction with both aqua regia and EDTA to highlight the distinct elemental mobility and (e) phyto-toxicological measurement of heavy metal concentrations in plants (Lactuca sativa acephala) grown on the studied soils. The results indicate (1) high soil salinity, often with drastic increase of sodium and chloride along the soil profiles, (2) high nitrogen content (in part related to anthropogenic activities) on superficial horizons and nitrate decrease along the soil profiles and (3) comparative enrichments in heavy metals with respect to other soils of the province, which indicate that peat deposits are effective in trapping metals from anthropogenic sources. This, in turn, implies potential geochemical risks for the agricultural activities. In this regard, specific concerns are related to the high nickel and arsenic content of MLL soils due to the mobility of these elements and their attitude to be taken up by plants.

  1. Submesoscale circulation in the northern Gulf of Mexico: Surface processes and the impact of the freshwater river input

    Science.gov (United States)

    Luo, Hao; Bracco, Annalisa; Cardona, Yuley; McWilliams, James C.

    2016-05-01

    The processes and instabilities occurring at the ocean surface in the northern Gulf of Mexico between 96.3°W-86.9°W and 25.4°N-30.7°N are investigated with a regional model at submesoscale-permitting horizontal grid resolution (i.e., HR with dx = 1.6 km) over a three-year period, from January 2010 to December 2012. A mesoscale-resolving, lower resolution run (LR, with dx = 5 km) is also considered for comparison. The HR run is obtained through two-way nesting within the LR run. In HR quantities such local Rossby number, horizontal divergence, vertical velocity, and strain rate are amplified in winter, when the mixed layer is deepest, as found in other basins. In the model configuration considered this amplification occurs in surface waters over the continental slope and off-shore but not over the shelf. Submesoscale structures consist of a mixture of fronts and eddies generated by frontogenesis and mixed layer instabilities, with elevated conversion rates of available potential energy (APE) into eddy kinetic energy (EKE). In all quantities a secondary maximum emerges during the summer season, when the mixed layer depth (MLD) is shallowest, barely 15-20 m. The secondary peak extends to the coast and is due to the intense lateral density gradients created by the fresh water inflow from the Mississippi River system. Submesoscale structures in summer consist predominately of fronts, as observed in the aftermath of the 2010 Deepwater Horizon oil spill, and their secondary circulations are impeded due to the limited depth of the mixed layer. Freshwater river input is key to the submesoscale activity in summer but modulates it also in winter, as shown with a sensitivity run in which the riverine inflow is absent. Implications for transport studies in regions characterized by intense freshwater fluxes and for submesoscale parameterizations are discussed.

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

    Institute of Scientific and Technical Information of China (English)

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

    2003-01-01

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

  3. Spatial distribution of contaminants in sediments of two rivers crossing Tangier (northern Morocco).

    Science.gov (United States)

    Rodríguez-Barroso, M R; Benhamou, Y; Coello, D; El Moumni, B; García-Morales, J L

    2010-02-01

    The distribution and accumulation of heavy metals in the sediments of two rivers which cross various agglomerations of Tangier city, Morocco, were investigated. Surficial sediment samples were collected during 2005 and characterized for metal content (Zn, Pb, Cd, Cu, Cr and Ni), organic matter, total nitrogen, and n-hexane extractable material (HEM). The organic components (organic carbon, total nitrogen and HEM) show a slightly increasing enrichment from the upstream to the downstream of the emissary. An evaluation of the heavy metal pollution status of both tributaries was carried out using the metal pollution index (MPI). The results revealed the importance of anthropic pressure and the zones influenced by industrial discharges, which keep the metals Pb, Cr and Ni at high levels. Comparison with international regulatory guidelines for sediments revealed serious contamination of Cr, Zn and Ni.

  4. A pesticide monitoring survey in rivers and lakes of northern Greece and its human and ecotoxicological risk assessment.

    Science.gov (United States)

    Papadakis, Emmaluel N; Vryzas, Zisis; Kotopoulou, Athena; Kintzikoglou, Katerina; Makris, Konstantinos C; Papadopoulou-Mourkidou, Euphemia

    2015-06-01

    A pesticide monitoring study covering the main rivers and lakes of Northern Greece (Macedonia, Thrace and Thessaly) was undertaken. A total of 416 samples were collected over a 1.5-year sampling period (September 1999- February 2001) from six rivers and ten lakes. The water samples were analyzed with an off-line solid phase extraction technique coupled with a gas chromatography ion trap mass spectrometer using an analytical method for 147 pesticides and their metabolites, including organochlorines, organophosphates, triazines, chloroacetanilides, pyrethroids, carbamates, phthalimides and other pesticides (herbicides, insecticides and fungicides). Based on the pesticide survey results, a human health carcinogenic and non-carcinogenic risk assessment was conducted for adults and children. Ecotoxicological risk assessment was also conducted using default endpoint values and the risk quotient method. Results showed that the herbicides metolachlor, prometryn, alachlor and molinate, were the most frequently detected pesticides (29%, 12.5%, 12.5% and 10%, respectively). They also exhibited the highest concentration values, often exceeding 1 μg/L. Chlorpyrifos ethyl was the most frequently detected insecticide (7%). Seasonal variations in measured pesticide concentrations were observed in all rivers and lakes. The highest concentrations were recorded during May-June period, right after pesticide application. Concentrations of six pesticides were above the maximum allowable limit of 0.1 μg/L set for drinking water. Alachlor, atrazine and a-HCH showed unacceptable carcinogenic risk estimates (4.5E-06, 4.6E-06 and 1.3E-04, respectively). Annual average concentrations of chlorpyriphos ethyl (0.031 μg L), dicofol (0.01 μg/L), dieldrin (0.02 μg/L) and endosulfan a (0.065 μg/L) exceeded the EU environmental quality standards. The risk quotient estimates for the insecticides chorpyrifos ethyl, diazinon and parathion methyl and herbicide prometryn were above acceptable risk

  5. Trace metal distribution in pristine permafrost-affected soils of the Lena River Delta and its Hinterland, Northern Siberia, Russia

    Directory of Open Access Journals (Sweden)

    I. Antcibor

    2013-02-01

    Full Text Available Soils are an important compartment of ecosystems and have the ability to immobilize chemicals preventing their movement to other environment compartments. Predicted climatic changes together with other anthropogenic influences on Arctic terrestrial environments may affect biogeochemical processes enhancing leaching and migration of trace elements in permafrost-affected soils. This is especially important since the Arctic ecosystems are considered to be very sensitive to climatic changes as well as to chemical contamination. This study characterizes background levels of trace metals in permafrost-affected soils of the Lena River Delta and its hinterland in northern Siberia (73.5° N–69.5° N representing a remote region far from evident anthropogenic trace metal sources. Investigations on total element contents of iron (Fe, arsenic (As, manganese (Mn, zinc (Zn, nickel (Ni, copper (Cu, lead (Pb, cadmium (Cd, cobalt (Co and mercury (Hg in different soil types developed in different geological parent materials have been carried out. The highest concentrations of the majority of the measured elements were observed in soils belonging to ice-rich permafrost sediments formed during the Pleistocene (ice-complex in the Lena River Delta region. Correlation analyses of trace metal concentrations and soil chemical and physical properties at a Holocene estuarine terrace and two modern floodplain levels in the southern-central Lena River Delta (Samoylov Island showed that the main factors controlling the trace metal distribution in these soils are organic matter content, soil texture and contents of iron and manganese-oxides. Principal Component Analysis (PCA revealed that soil oxides play a significant role in trace metal distribution in both top and bottom horizons. Occurrence of organic matter contributes to Cd binding in top soils and Cu binding in bottom horizons. Observed ranges of the background concentrations of the majority of trace elements were

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

    Energy Technology Data Exchange (ETDEWEB)

    Sasao, Eiji [Japan Nuclear Cycle Development Inst., Toki, Gifu (Japan). Tono Geoscience Center

    2003-07-01

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

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

    Science.gov (United States)

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

    2016-08-01

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

  8. Structure of parasites community in Chaetobranchopsis orbicularis (Cichlidae), a host from the Amazon River system in northern Brazil.

    Science.gov (United States)

    Tavares-Dias, Marcos; Oliveira, Marcos Sidney Brito

    2017-08-01

    The aim of this paper was to investigate the component communities of parasites in Chaetobranchopsis orbicularis from a tributary of the Amazon River system, in Northern Brazil. In 32 fish examined, 902,551 parasites were collected, including Ichthyophthirius multifiliis, Piscinoodinium pillulare, Sciadicleithrum geophagi, Posthodiplostomum sp., Clinostomum marginatum, Echinorhynchus paranensis, Neoechinorhynchus pterodoridis, and Dolops longicauda. I. multifiliis was the dominant and abundant parasite species. The ectoparasites presented aggregate dispersion, but the endoparasites showed random dispersion pattern. Mean species richness was 4.0 ± 1.5 parasites, mean Brillouin diversity (HB) was 0.33 ± 0.28, mean evenness was 0.15 ± 0.13, and Berger-Parker dominance (d) was 0.85 ± 0.17. The species richness of parasites and HB were positively correlated with the length of hosts. There was positive correlation between the abundance of P. pillulare and length and weight, between the abundance of I. multifiliis and weight, as well as between the abundance of E. paranensis and N. pterodoridis and the length of hosts. Body condition of the hosts was not affected by moderate parasitism. The low diversity of endoparasites indicates that C. orbicularis is a host with low position in the food web. This is the first record of all these parasites for C. orbicularis.

  9. Ectoparasites and endoparasites community of Ageneiosus ucayalensis (Siluriformes: Auchenipteridae), catfish from Amazon River system in northern Brazil.

    Science.gov (United States)

    de Oliveira Ferreira, Drielly; Tavares-Dias, Marcos

    2017-09-01

    This study investigated the community of ectoparasites and endoparasites in Ageneiosus ucayalensis (Auchenipteridae) of a tributary from the Amazon River system, in Northern Brazil. Of 34 fish examined, 100% were parasitized by Ichthyophthirius multifiliis, Cosmetocleithrum bulbocirrus, Demidospermus sp., metacercariae of Genarchella genarchella, Clinostomum marginatum and Herpetodiplostomum sp., Procamallanus (Spirocamallanus) belenensis, Cucullanus ageneiosus and larvae of Contracaecum sp. digeneans C. marginatum and Herpetodiplostomum sp. were dominant parasite species, while I. multifiliis was the parasite with higher infection level. Such parasite species showed an aggregated dispersion, except P. (S.) belenensis, which showed a random dispersion. The Brillouin diversity (0.53 ± 0.29) was high, while evenness (0.28 ± 0.16) and species richness of parasites (3.7 ± 1.1) were low. The size of the hosts did not influence diversity, species richness and abundance of parasites. The ectoparasites were characterized by high prevalence and abundance, while endoparasites community presented low prevalence and abundance. The main factors responsible for structuring the parasite community in A. ucayalensis were mainly the behavior of this host and the availability of endoparasites infective stages in the environment. This was the first report of I. multifiliis, C. bulbocirus, Demidospermus sp., Contracaecum sp., C. marginatum, Herpetodiplostomum sp. and G. genarchella for A. ucayalensis. The presence of endohelminth larvae suggests that A. ucayalensis is part of the diet of other fish at the top of the food web in the Amazonian ecosystem studied.

  10. Growth and mortality of age-0 northern squawfish, Ptychocheilus oregonensis, rearing in shoreline habitats of the Columbia River Reservoir

    Science.gov (United States)

    Barfoot, C.A.; Gadomski, D.M.; Wertheimer, R.H.

    1999-01-01

    We investigated growth and mortality of age-0 northern squawfish during early rearing in shallow shoreline habitats. Larvae and juveniles (n=22914) were collected by weekly seining at three sample sites in the upper John Day Reservoir, Columbia River, during June through early September 1994–1996. Using a length-based ageing method, it was estimated that the exponential growth rate (G) for a common growth stanza (10–28 mm standard length SL) was significantly higher in 1994 (G=0.047) than in 1996 (G=0.037). Growth rate in 1995 could not be estimated, but was probably intermediate between 1994 and 1996 based on mean standard lengths of fish collected at the end of each sampling season (46.3, 40.0, and 32.0 mm SL in 1994, 1995, and 1996, respectively). For many fish species, variations in early growth can influence survival through size-selective mortality processes. Consistent with this possibility, our estimates of instantaneous mortality rates (Z) demonstrated that larvae and juveniles had significantly higher mortality in 1996 than in 1994 (Z=0.103 in 1994, versus Z=0.138 in 1996). Enhanced growth and lower mortality in 1994 were associated with a number of interrelated environmental conditions – comparatively low flows and turbidities, abundant instream vegetative cover, and high near-shore water temperatures.

  11. Geothermal assessment of the lower Bear River drainage and northern East Shore ground-water areas, Box Elder County, Utah

    Energy Technology Data Exchange (ETDEWEB)

    Klauk, R.H.; Budding, K.E.

    1984-07-01

    The Utah Geological and Mineral Survey (UGMS) has been researching the low-temperature geothermal resource potential in Utah. This report, part of an area-wide geothermal research program along the Wasatch Front, concerns the study conducted in the lower Bear River drainage and northern East Shore ground-water areas in Box Elder County, Utah. The primary purpose of the study is to identify new areas of geothermal resource potential. There are seven known low-temperature geothermal areas in this part of Box Elder County. Geothermal reconnaissance techniques used in the study include a temperature survey, chemical analysis of well and spring waters, and temperature-depth measurements in accessible wells. The geothermal reconnaissance techniques identified three areas which need further evaluation of their low-temperature geothermal resource potential. Area 1 is located in the area surrounding Little Mountain, area 2 is west and southwest of Plymouth, and area 3 is west and south of the Cutler Dam. 5 figures, 4 tables.

  12. Radionuclide migration at the Koongarra uranium deposit, Northern Australia Lessons from the Alligator Rivers analogue project

    Science.gov (United States)

    Payne, Timothy E.; Airey, Peter L.

    The Koongarra uranium deposit in Northern Australia provides a ‘natural analogue’ for processes that are of relevance for assessing the safety of radioactive waste disposal. In an international project extending over two decades, the Koongarra ore body was studied to increase the understanding of radionuclide migration and retention mechanisms that might occur in the vicinity of a geological repository. The research effort included extensive characterisation of the geological, hydrological and geochemical conditions at the site. Patterns of the distribution of radionuclides (predominantly members of the 238U decay chain, but also the rare isotopes 239Pu, 99Tc and 129I) were studied in both solid and groundwater phases. The project included detailed studies of uranium adsorption on mineral surfaces, and of subsequent processes that may lead to long-term uranium immobilisation. Numerous models for uranium migration were developed during the project. This paper provides a comprehensive review of the research at Koongarra, and assesses the value of the site for integrating the results of a complex series of laboratory, modelling and field studies. The insights gained from this review of the Koongarra project may assist in maximising the potential scientific benefit of future natural analogue studies.

  13. Spatio-temporal Variability of Northern Hemipheric Sea Level Pressure (SLP) and Precipitation overthe Mid-to-Low Reaches of the Yangtze River

    Institute of Scientific and Technical Information of China (English)

    HAN Xue; WEI Fengying; Yves M.TOURRE; DONG Wenjie

    2008-01-01

    The spatio-temporal variability of Northern Hemisphere Sea Level Pressure (SLP) and precipitation over the mid-to-low reaches of the Yangtze River (PMLY) is analyzed jointly using the multi-taper /singular value decomposition method (MTM-SVD). Statistically significant narrow frequency bands are obtained from the local fractional variance (LFV) spectrum. Significant interdecadal (i.e., 16-to-18-year periods) and interannual (i.e., 3-to-6-year periods) signals are identified. Moreover, a significant quasi-biennial signal is identified but only for PMLY data. The spatial joint evolution of patterns obtained for peaks in the LFV spectrum sheds light on relationships between SLP and PMLY: the Arctic Oscillation (AO) modulates the variability of the PMLY while the interannual variability of PMLY is in phase with the Northern Atlantic Oscillation (NAO) and the Northern Pacific Oscillation (NPO).

  14. Using bioenergetics modeling to estimate consumption of native juvenile salmonids by nonnative northern pike in the Upper Flathead River System, Montana

    Science.gov (United States)

    Muhlfeld, C.C.; Bennett, D.H.; Kirk, Steinhorst R.; Marotz, B.; Boyer, M.

    2008-01-01

    Introductions of nonnative northern pike Esox lucius have created recreational fisheries in many waters in the United States and Canada, yet many studies have shown that introduced northern pike may alter the composition and structure of fish communities through predation. We estimated the abundance of nonnative northern pike (2002-2003) and applied food habits data (1999-2003) to estimate their annual consumption of native bull trout Salvelinus confluentus and westslope cutthroat trout Oncorhynchus clarkii lewisi juveniles in the upper Flathead River system, Montana. Population estimates were generally consistent among years and ranged from 1,200 to 1,300 individuals. Westslope cutthroat trout were present in the diet of younger (???600 mm) and older (>600 mm) northern pike during all seasons and bull trout were found only in larger northern pike during all seasons but summer. Bioenergetics modeling estimated that the northern pike population annually consumed a total of 8.0 metric tons (mt) of fish flesh; the highest biomass was composed of cyprinids (4.95 mt) followed by whitefishes Prosopium spp. (1.02 mt), bull trout (0.80 mt), westslope cutthroat trout (0.68 mt), yellow perch Perca flavescens (0.41 mt),1 and other fishes (centrarchids and cottids; 0.14 mt). Numerically, the northern pike population consumed more than 342,000 fish; cyprinids and catostomids comprised approximately 82% of prey fish (278,925), whereas over 13,000 westslope cutthroat trout and nearly 3,500 bull trout were eaten, comprising about 5% of the prey consumed. Our results suggest that predation by introduced northern pike is contributing to the lower abundance of native salmonids in the system and that a possible benefit might accrue to native salmonids by reducing these predatory interactions. ?? Copyright by the American Fisheries Society 2008.

  15. Germanium-silicon fractionation in a river-influenced continental margin: The Northern Gulf of Mexico

    Science.gov (United States)

    Baronas, J. Jotautas; Hammond, Douglas E.; Berelson, William M.; McManus, James; Severmann, Silke

    2016-04-01

    In this study we have sampled the water column and sediments of the Gulf of Mexico to investigate the effects of high riverine terrigenous load and sediment redox conditions on the cycling of Ge and Si. Water column Ge/Si ratios across the Gulf of Mexico continental shelf range from 1.9 to 25 μmol/mol, which is elevated compared to the global ocean value of 0.7 μmol/mol. The Ge enrichment in the Gulf of Mexico seawater is primarily due to anthropogenic contamination of the Mississippi river, which is the main Ge and Si source to the area, and to a smaller extent due to discrimination against Ge during biogenic silica (bSi) production (Ge/Si = 1.2-1.8 μmol/mol), especially by radiolarians and siliceous sponges (Ge/Si = 0.6-1.1 μmol/mol). Most sediment pore waters (Ge/Si = 0.3-4.5 μmol/mol) and sediment incubation experiments (benthic flux Ge/Si = 0.9-1.2 μmol/mol) indicate precipitation of authigenic phases that sequester Ge from pore waters (non-opal sink). This process appears to be independent of oxidation-reduction reactions and suggests that authigenic aluminosilicate formation (reverse weathering) may be the dominant Ge sink in marine sediments. Compilation of previously published data shows that in continental margins, non-opal Ge burial flux is controlled by bSi supply, while in open ocean sediments it is 10-100 times lower and most likely limited by the supply of lithogenic material. We provide a measurement-based estimate of the global non-opal Ge burial flux as 4-32 Mmol yr-1, encompassing the 2-16 Mmol yr-1 needed to keep the global marine Ge cycle at steady state.

  16. On metal diagenesis in contaminated sediments of the Deule river (northern France)

    Energy Technology Data Exchange (ETDEWEB)

    Lesven, L. [Universite Lille 1 (USTL), FRE CNRS 3298 Geosystemes, Equipe de Chimie Analytique et Marine, 59655 Villeneuve d' Ascq cedex (France); Lourino-Cabana, B. [Universite Lille 1 (USTL), FRE CNRS 3298 Geosystemes, Equipe de Chimie Analytique et Marine, 59655 Villeneuve d' Ascq cedex (France)] [Faculty of Natural Sciences and Technology, Department of Chemistry, 7491 Trondheim (Norway); Billon, G.; Recourt, P. [Universite Lille 1 (USTL), FRE CNRS 3298 Geosystemes, Equipe de Chimie Analytique et Marine, 59655 Villeneuve d' Ascq cedex (France); Ouddane, B., E-mail: baghdad.ouddane@univ-lille1.fr [Universite Lille 1 (USTL), FRE CNRS 3298 Geosystemes, Equipe de Chimie Analytique et Marine, 59655 Villeneuve d' Ascq cedex (France); Mikkelsen, O. [Faculty of Natural Sciences and Technology, Department of Chemistry, 7491 Trondheim (Norway); Boughriet, A. [Universite d' Artois, I.U.T. de Bethune Departement de Chimie, Rue de l' Universite, B.P. 819, 62408 Bethune cedex (France)

    2010-09-15

    Research highlights: {yields} Behaviour and fate of metal contaminants in sediments (remobilisation, dredging ...). {yields} Implication of metal contaminations on biogeochemical processes in anoxic sediments. {yields} Impacts on the distribution of anthropogenic metal in sediments. - Abstract: The objective of the present work was to assess depth-related variations in the (bio)geochemical processes involved in anoxic sediments from the Deule river, and to examine particularly their impacts on the distribution of anthropogenically sourced metals. Anoxic sediment samples were sliced and analyzed to determine total concentrations vs. depth of elements and corresponding pore waters were analyzed to determine concentration profiles with depth of pH, Eh, alkalinity, O{sub 2}, dissolved organic carbon (DOC), and main inorganic anions and cations present in the medium. It was shown that rapid depletions of O{sub 2}, NO{sub 3}{sup -} and SO{sub 4}{sup 2-}, accompanied with HCO{sub 3}{sup -} generation and a sharp decrease in the redox potential occurred within the first centimeters of the surface sediment as a consequence of early diagenesis. Bacterial reductive dissolution of Mn(III and IV) and Fe(III) oxides/hydroxides to Mn(II) and Fe(II) accompanied by microbial degradation of organic matter took place as well, and resulted in trace metal increases in the pore water at levels that raised the possibility of mineral generation. Thermodynamic calculations predicted removal of metals from interstitial waters through combinations with carbonates and/or sulfides. These took place either by direct precipitation to form pure crystals, or by coprecipitation/sorption with/into calcite and with pyritic compounds. Chemical sequential extraction data were useful in this work to support, at least partially, some thermodynamic predictions concerning the existence of interactions between trace metals and carbonate and sulfide ions to generate (co)precipitates. Electron paramagnetic

  17. The exchange of carbon dioxide between wet arctic tundra and the atmosphere at the Lena River Delta, Northern Siberia

    Directory of Open Access Journals (Sweden)

    L. Kutzbach

    2007-06-01

    Full Text Available The exchange fluxes of carbon dioxide between wet arctic polygonal tundra and the atmosphere were investigated by the micrometeorological eddy covariance method. The investigation site was situated in the centre of the Lena River Delta in Northern Siberia (72°22' N, 126°30' E. The study region is characterized by a polar and distinctly continental climate, very cold and ice-rich permafrost and its position at the interface between the Eurasian continent and the Arctic Ocean. The soils at the site are characterized by high organic matter content, low nutrient availability and pronounced water logging. The vegetation is dominated by sedges and mosses. The micrometeorological campaigns were performed during the periods July–October 2003 and May–July 2004 which included the period of snow and soil thaw as well as the beginning of soil refreeze. The main CO2 exchange processes, the gross photosynthesis and the ecosystem respiration, were found to be of a generally low intensity. The gross photosynthesis accumulated to –432 g m−2 over the photosynthetically active period (June–September. The contribution of mosses to the gross photosynthesis was estimated to be about 40%. The diurnal trend of the gross photosynthesis was mainly controlled by the incoming photosynthetically active radiation. During midday the photosynthetic apparatus of the canopy was frequently near saturation and represented the limiting factor on gross photosynthesis. The synoptic weather conditions strongly affected the exchange fluxes of CO2 by changes in cloudiness, precipitation and pronounced changes of air temperature. The ecosystem respiration accumulated to +327 g m−2 over the photosynthetically active period, which corresponds to 76% of the CO2 uptake by photosynthesis. However, the ecosystem respiration continued at substantial rates during autumn when photosynthesis had ceased and the soils

  18. The exchange of carbon dioxide between wet arctic tundra and the atmosphere at the Lena River Delta, Northern Siberia

    Science.gov (United States)

    Kutzbach, L.; Wille, C.; Pfeiffer, E.-M.

    2007-10-01

    The exchange fluxes of carbon dioxide between wet arctic polygonal tundra and the atmosphere were investigated by the micrometeorological eddy covariance method. The investigation site was situated in the centre of the Lena River Delta in Northern Siberia (72°22' N, 126°30' E). The study region is characterized by a polar and distinctly continental climate, very cold and ice-rich permafrost and its position at the interface between the Eurasian continent and the Arctic Ocean. The soils at the site are characterized by high organic matter content, low nutrient availability and pronounced water logging. The vegetation is dominated by sedges and mosses. The micrometeorological campaigns were performed during the periods July-October 2003 and May-July 2004 which included the period of snow and soil thaw as well as the beginning of soil refreeze. The main CO2 exchange processes, the gross photosynthesis and the ecosystem respiration, were found to be of a generally low intensity. The gross photosynthesis accumulated to -432 g m-2 over the photosynthetically active period (June-September). The contribution of mosses to the gross photosynthesis was estimated to be about 40%. The diurnal trend of the gross photosynthesis was mainly controlled by the incoming photosynthetically active radiation. During midday, the photosynthetic apparatus of the canopy was frequently near saturation and represented the limiting factor on gross photosynthesis. The synoptic weather conditions strongly affected the exchange fluxes of CO2 by changes in cloudiness, precipitation and pronounced changes of air temperature. The ecosystem respiration accumulated to +327 g m-2 over the photosynthetically active period, which corresponds to 76% of the CO2 uptake by photosynthesis. However, the ecosystem respiration continued at substantial rates during autumn when photosynthesis had ceased and the soils were still largely unfrozen. The temporal variability of the ecosystem respiration during summer

  19. Patterns of fish use and piscivore abundance within a reconnected saltmarsh impoundment in the northern Indian River Lagoon, Florida

    Science.gov (United States)

    Stevens, Philip W.; Montague, C.L.; Sulak, K.J.

    2006-01-01

    Nearly all saltmarshes in east-central, Florida were impounded for mosquito control during the 1960s. The majority of these marshes have since been reconnected to the estuary by culverts, providing an opportunity to effectively measure exchange of aquatic organisms. A multi-gear approach was used monthly to simultaneously estimate fish standing stock (cast net), fish exchange with the estuary (culvert traps), and piscivore abundance (gill nets and bird counts) to document patterns of fish use in a reconnected saltmarsh impoundment. Changes in saltmarsh fish abundance, and exchange of fish with the estuary reflected the seasonal pattern of marsh flooding in the northern Indian River Lagoon system. During a 6-month period of marsh flooding, resident fish had continuous access to the marsh surface. Large piscivorous fish regularly entered the impoundment via creeks and ditches to prey upon small resident fish, and piscivorous birds aggregated following major fish movements to the marsh surface or to deep habitats. As water levels receded in winter, saltmarsh fish concentrated into deep habitats and emigration to the estuary ensued (200% greater biomass left the impoundment than entered). Fish abundance and community structure along the estuary shoreline (although fringed with marsh vegetation) were not analogous to marsh creeks and ditches. Perimeter ditches provided deep-water habitat for large estuarine predators, and shallow creeks served as an alternative habitat for resident fish when the marsh surface was dry. Use of the impoundment as nursery by transients was limited to Mugil cephalus Linnaeus, but large juvenile and adult piscivorous fish used the impoundment for feeding. In conclusion, the saltmarsh impoundment was a feeding site for piscivorous fish and birds, and functioned as a net exporter of forage fish to adjacent estuarine waters. ?? Springer 2006.

  20. Magmatism as a response to exhumation of the Priest River complex, northern Idaho: Constraints from zircon U-Pb geochronology and Hf isotopes

    Science.gov (United States)

    Stevens, L. M.; Baldwin, J. A.; Crowley, J. L.; Fisher, C. M.; Vervoort, J. D.

    2016-10-01

    Zircon and monazite U-Pb geochronology and zircon Hf isotopes place constraints on the temporal and source relationships between crustal anatexis, magmatism, and exhumation of the Priest River metamorphic core complex, northern Idaho. Granitoids that intruded the migmatitic, pelitic Hauser Lake gneiss include the pluton emplacement in the Priest River complex indicates that it was primarily a response to decompression rather than a cause. The mylonitized Silver Point and undeformed Wrencoe plutons bracket the end of a rapid phase of exhumation to c. 50-48 Ma. Zircon εHf(i) values and Lu-Hf isotope evolution indicate that the Silver Point and Wrencoe plutons crystallized from homogeneous magmas sourced from Archean-Proterozoic basement orthogneisses, whereas the Spokane granite and two leucocratic units appear to have been produced by partial melting of the Hauser Lake gneiss. Comparison of the Priest River complex with other deeply exhumed northern Cordilleran complexes indicates variability in the timing and, therefore, relative influences of partial melting and magmatism on the initiation of exhumation, which must be accounted for in numerical models of metamorphic core complex formation and evolution.

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

    Directory of Open Access Journals (Sweden)

    Penelope L. King

    2017-02-01

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

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

    Science.gov (United States)

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

    2017-02-01

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

  3. Analytical results and sample locations of reanalyzed NURE stream-sediment and soil samples for the Humboldt River basin mineral-environmental assessment, northern Nevada

    Science.gov (United States)

    Folger, H. W.

    2000-01-01

    The U.S. Geological Survey (USGS), in cooperation with the Bureau of Land Management (BLM), began a study in 1996 to describe to the geochemistry of the Humboldt River Basin. The principal sample media evaluated are stream-sediment and soil samples retrieved from the National Uranium Resource Evaluation (NURE) archives located in Denver, Colorado. Samples were retrieved from the Wells, McDermitt, Vya, Lovelock, Winnemucca, Elko, Ely, Millett, Reno, and Tonopah 1? x 2? quadrangles in northern Nevada. The data are appropriate for large-scale reconnaissance resource evaluations and landscape geochemical-geoenvironmental evaluations. The analytical results are presented in this report.

  4. The Crati River Basin: geomorphological and stratigraphical data for the Plio–Quaternary evolution of northern Calabria, South Apennines, Italy

    Directory of Open Access Journals (Sweden)

    Robustelli Gaetano

    2017-02-01

    Full Text Available In this paper, we present the results of an integrated geomorphological and stratigraphical study carried out in the eastern side of the Crati River valley (northern Calabria, South Italy. This area is characterized by the occurrence of three order palaeosurfaces that, along with low-sloping palaeovalleys and structural landforms, are striking features of the landscape. The relationships between morpho-tectonic and sedimentary evolution of the Crati Basin has been assessed through sandstone detrital modes, morphostratigraphy and geomorphological correlation with adjacent areas. The two main unconformity surfaces that typify the Quaternary fill were correlated to different steps of landscape evolution. The presence of both erosional and depositional palaeosurfaces has been a useful marker for reconstructing sedimentary and morphogenetic events, and hence to detect drainage network evolution and changes in source sediment area. In particular, we recognized that the study area experienced, during the late Pliocene–Early Pleistocene a period of sub-aerial landscape modelling as suggested by low-sloping palaeovalleys and related fluvial deposits (1st Order Palaeosurface. At that time, the source of the detrital constituents of the PPS Unit sandstones was mainly from the Sila Massif. The onset of Coastal Range identification and uplift (Early Pleistocene marks a change in the geomorphic scenario with tectonic driven stream incision and valley development along the eastern side of Coastal Range, along with the occurrence of depositional and erosional landsurfaces (2nd Order Palaeosurface at footslopes. During this period, the Coastal Range and Sila Massif were the sources for the detrital constituents of the PlS Unit sandstones. The progressive uplift of Coastal Range during late Early Pleistocene and the marked backstepping of the depositional systems along the Sila footslope was accompanied by alternating phases of down-cutting and base

  5. The Crati River Basin: geomorphological and stratigraphical data for the Plio-Quaternary evolution of northern Calabria, South Apennines, Italy

    Science.gov (United States)

    Robustelli, Gaetano; Muto, Francesco

    2017-02-01

    In this paper, we present the results of an integrated geomorphological and stratigraphical study carried out in the eastern side of the Crati River valley (northern Calabria, South Italy). This area is characterized by the occurrence of three order palaeosurfaces that, along with low-sloping palaeovalleys and structural landforms, are striking features of the landscape. The relationships between morpho-tectonic and sedimentary evolution of the Crati Basin has been assessed through sandstone detrital modes, morphostratigraphy and geomorphological correlation with adjacent areas. The two main unconformity surfaces that typify the Quaternary fill were correlated to different steps of landscape evolution. The presence of both erosional and depositional palaeosurfaces has been a useful marker for reconstructing sedimentary and morphogenetic events, and hence to detect drainage network evolution and changes in source sediment area. In particular, we recognized that the study area experienced, during the late Pliocene-Early Pleistocene a period of sub-aerial landscape modelling as suggested by low-sloping palaeovalleys and related fluvial deposits (1st Order Palaeosurface). At that time, the source of the detrital constituents of the PPS Unit sandstones was mainly from the Sila Massif. The onset of Coastal Range identification and uplift (Early Pleistocene) marks a change in the geomorphic scenario with tectonic driven stream incision and valley development along the eastern side of Coastal Range, along with the occurrence of depositional and erosional landsurfaces (2nd Order Palaeosurface) at footslopes. During this period, the Coastal Range and Sila Massif were the sources for the detrital constituents of the PlS Unit sandstones. The progressive uplift of Coastal Range during late Early Pleistocene and the marked backstepping of the depositional systems along the Sila footslope was accompanied by alternating phases of down-cutting and base-level stability resulting in

  6. Milankovitch orbital cycles encoded by diagenetic iron sulfides in Neogene sediments, Stirone River section, Northern Apennines, Italy

    Science.gov (United States)

    Gunderson, K. L.; Kodama, K. P.; Anastasio, D. J.; Pazzaglia, F. J.

    2009-12-01

    We used rock magnetic parameters to identify Milankovitch orbital cycles in the marine sediments of the Messinian-Early Pleistocene Stirone River section, Northern Apennines, Italy. These measurements provide excellent proxies for subtle changes in depositional environment, including climate, in stratigraphic sections where facies variations are not evident. We measured 636 meters of section and collected samples every 1 meter, for which we measured magnetic susceptibility (MS), natural remanent magnetization (NRM), anhysteretic magnetization in a 40 mT peak alternating field(40mT ARM), and anhysteretic remanent magnetization in a 100 mT peak alternating field (100mT ARM). We present the results of our time-series analysis of the MS, 40mT ARM, and 100mT ARM stratigraphic series for 310 meters of section, encompassing the time period between 3.1 My and 1.8 My. During this time period, the power spectra produced from the MS stratigraphic series exhibits peaks with frequencies at 1/24m, 1/10m, and 1/6m. Based on our calculated mean sedimentation rate of 0.24 m/ky, we interpret the spectral peaks to be associated with the eccentricity, obliquity, and precessional orbital cycles, respectively. The 40mT ARM spectra exhibits peaks at similar periodicities, but the corresponding spectral peaks are broader and the spectral power is much lower. The 100mT ARM spectra shows an increase in spectral power with respect to the 40mT ARM, but it also exhibits broad spectral peaks. Low temperature (77 K) susceptibility (LT-MS) and isothermal remanent magnetization (IRM) acquisition experiments were conducted to determine which magnetic minerals carry the MS signal. The observed increase of the MS at low temperature (6-140%) was not large enough to conclude that the MS is dominated by paramagnetic grains. IRM acquisition modeling indicates two components of magnetization: (1) a major component comprising ~85% of the magnetization with a mean coercivity of 67 mT and (2) a minor

  7. Floodplain deposits, channel changes and riverbank stratigraphy of the Mekong River area at the 14th-Century city of Chiang Saen, Northern Thailand

    Science.gov (United States)

    Wood, Spencer H.; Ziegler, Alan D.; Bundarnsin, Tharaporn

    2008-10-01

    Riverbank stratigraphy and paleochannel patterns of the Mekong River at Chiang Saen provide a geoarchaeological framework to explore for evidence of Neolithic, Bronze-age, AD 5th Century Yonok and AD 14-16th Century Lan Na Cultures. Typical bank stratigraphy charted on the Thailand side is imbricate cobble gravel overlain by 5-10 m of reddish-brown sandy silt. The silt section is composed chiefly of 1/2 to 2-m thick layers of massive silt without paleosols interpreted as near-channel floodplain and gently-inclined levee deposits laid down by episodic, infrequent, large floods. The surface soil is dark-brown clay loam (pottery shards and charcoal of Lan Na time. Brick ruins of 14-16th Century Buddhist temples are crumbling into the river at Chiang Saen Noi, and formerly did so at Chiang Saen until banks were stabilized by rock walls. Bank retreat from river erosion has been > 20 m since Lan Na time, and has exposed a silt-filled moat. A radiocarbon age of 1475 cal yr AD was obtained from charcoal at the bottom of the moat, beneath 5.6 m of silt. Lag material from erosion of the silt banks contains Neolithic and Bronze Age artifacts out of stratigraphic context, as well as ceramics and bricks of Lan Na age. These artifacts as well Neolithic artifacts obtained from a 1972 excavation near the mouth of the Kham River indicate long human habitation of this riverbank area. In northern Thailand the Mekong is mostly in a bedrock canyon, but shifting topography along the active strike-slip Mae Chan fault has formed the upstream 2-5-km wide floodplain at Chiang Saen, and downstream has diverted the river into a broad S-shaped loop in the otherwise straight course of the river. A 1.7-Ma basalt within the bedrock channel 45-km downstream of Chiang Saen indicates little vertical incision by the river. Satellite images show former channels in the Chiang Saen area, meander-point-bar scrolls (radii of curvature > 1.2 km), and floodplain edges as arcuate cuts of similar curvature

  8. ADULT DRAGONFLY COMMUNITIES IN TROPICAL RIVERS OF THE NORTHERN PENINSULAR MALAYSIA: SPECIES COMPOSITION, BIOTOPE AND HOST PLANT PREFERRENCES

    Institute of Scientific and Technical Information of China (English)

    Wahizatul Afzan A; Che Salmah M R

    2005-01-01

    Adult dragonfly communities were dominated by Libellulidae as 29 species were successfully collected from this family in marginal areas of Saleh, Setul and Serdang rivers. Zygopterans Coenagrionidae, Platycnemididae, Calopterygidae were common while Gomphidae and Chlorocyphidae were rather rare. Libellulids Neurothemis fluctuans, Trithemis aurora, Crocothemis servilia, T. festiva and Orthetrum chrysis were widely distributed in shaded, muddy areas. Among the zygopterans, Pseudagrion pruinosumwas the most dominant species. Agriocnemis femina, Ictinogomphus rapax, Cratilla lineata, Lathrecista asiatica, Neurothemis tullia, Tholymis tillarga and Copera ciliata were strictly found at Saleh River implicating their preference for smaller, slow moving and polluted river with floating microphytes and few other surrounding plant species. Neurobasis chinensis and Vestalis gracilis were only found in open, undisturbed, fast flowing waters of Setul and Serdang rivers. Generally the adults perched on marginal vegetation as well as those on the river bank areas.

  9. Effects of reintroduced beaver (Castor canadensis) on riparian bird community structure along the upper San Pedro River, southeastern Arizona and northern Sonora, Mexico

    Science.gov (United States)

    Johnson, Glenn E.; van Riper, Charles

    2014-01-01

    Chapter 1.—We measured bird abundance and richness along the upper San Pedro River in 2005 and 2006, in order to document how beavers (Castor canadensis) may act as ecosystem engineers after their reintroduction to a desert riparian area in the Southwestern United States. In areas where beavers colonized, we found higher bird abundance and richness of bird groups, such as all breeding birds, insectivorous birds, and riparian specialists, and higher relative abundance of many individual species—including several avian species of conservation concern. Chapter 2.—We conducted bird surveys in riparian areas along the upper San Pedro River in southeastern Arizona (United States) and northern Sonora (Mexico) in order to describe factors influencing bird community dynamics and the distribution and abundance of species, particularly those of conservation concern. These surveys were also used to document the effects of the ecosystem-altering activities of a recently reintroduced beavers (Castor canadensis). Chapter 3.—We reviewed Southwestern Willow Flycatcher (Empidonax traillii extimus) nest records and investigated the potential for future breeding along the upper San Pedro River in southeastern Arizona, where in July 2005 we encountered the southernmost verifiable nest attempt for the species. Continued conservation and management of the area’s riparian vegetation and surface water has potential to contribute additional breeding sites for this endangered Willow Flycatcher subspecies. Given the nest record along the upper San Pedro River and the presence of high-density breeding sites to the north, the native cottonwood-willow forests of the upper San Pedro River could become increasingly important to E. t. extimus recovery, especially considering the anticipated effect of the tamarisk leaf beetle (Diorhabda carinulata) on riparian habitat north of the region.

  10. Timing and development of Late Quaternary fluvial terraces of the lower course of Kızılırmak River (Northern Turkey)

    Science.gov (United States)

    Berndt, Christopher; Yıldırım, Cengiz; Çiner, Attila; Ertunç, Gülgün; Akif Sarıkaya, M.; Özcan, Orkan; Güneç Kıyak, Nafiye; Öztürk, Tuǧba

    2017-04-01

    The Kızılırmak River (1355 km) is the longest river of Anatolia. It traverses the Central Pontides and forms deep bedrock gorges, fluvial and deltaic terraces along its lower stream and a large delta into the Black Sea. The Central Pontides is an actively deforming and uplifting mountain range located at the northern margin of the Central Anatolian Plateau (CAP). The presence of strath terraces and uplifted paleo-delta levels along the lower course of the river indicates a response of Kızılırmak to active uplift of the Central Pontides and sea-level fluctuations of the Black Sea. To understand the Quaternary tectonic, climatic and sea level impacts on the lower stream and delta of the Kızılırmak River, we carried out geologic and geomorphic mapping of several fluvial and deltaic terraces in order to date 5 levels by optically stimulated luminescence dating (OSL) method. Our results indicate accelerated regional uplift since Middle Pleistocene in the eastern part of the Central Pontides with uplift rates varying between about 0.07 and 0.3 m/ka. The delta terraces at 103 and 123 m above mean river level on the western side of Kızılırmak River uplifted presumably faster than the terraces at 58 and 87 m above mean river level on the eastern side by 0.2-0.3 m/ka. Since MIS 9 the western and eastern delta platforms uplift coherently with 0.2 m/ka or less. The southern part of the delta is delimited by Alaçam Segment of the Erikli Fault. The area south of the Alaçam segment of the Erikli Fault is uplifting faster than the region to the north of it (0.07 m/ka) since Middle Pleistocene. This indicates a tectonic interaction between the positive flower structure of the North Anatolian Fault Zone and an active rifting of the Sinop Graben over the Erikli Fault system.

  11. A Study of the Response of Eastern Spiny Softshell Turtle to Boat Traffic in the Missisquoi River of Northern Vermont

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The purpose of this study was to gauge the degree to which boat traffic in the Missisquoi River affects the basking behavior of the eastern spiny softshell turtle...

  12. Construction, calibration, and validation of the RBM10 water temperature model for the Trinity River, northern California

    Science.gov (United States)

    Jones, Edward C.; Perry, Russell W.; Risley, John C.; Som, Nicholas A.; Hetrick, Nicholas J.

    2016-03-31

    We constructed a one-dimensional daily averaged water-temperature model to simulate Trinity River temperatures for 1980–2013. The purpose of this model is to assess effects of water-management actions on water temperature and to provide water temperature inputs for a salmon population dynamics model. Simulated meteorological data, observed streamflow data, and observed water temperatures were used as model inputs to simulate a continuous 34-year time series of historical daily mean water temperature at eight locations along 112.2 river miles from Lewiston Dam near Weaverville, California, downstream to the Klamath River confluence. To demonstrate the utility of the model to inform management actions, we simulated three management alternatives to assess the effects of bypass flow augmentation in a drought year, 1994, and compared those results to the simulated historical baseline, referred to as the “No Action” alternative scenario. Augmentation flows from the Lewiston Dam bypass consist of temperature-controlled releases capable of cooling downstream water temperatures in hot times of the year, which can reduce the probability of disease outbreaks in fish populations. Outputs from the Trinity River water-temperature model were then used as inputs to an existing water-temperature model of the Klamath River to evaluate the effect of augmentation flow releases on water temperatures in the lower Klamath River

  13. Fine scale habitat use by age-1 stocked muskellunge and wild northern pike in an upper St. Lawrence River bay

    Science.gov (United States)

    Farrell, John M.; Kapuscinski, Kevin L.; Underwood, Harold

    2014-01-01

    Radio telemetry of stocked muskellunge (n = 6) and wild northern pike (n = 6) was used to track late summer and fall movements from a common release point in a known shared nursery bay to test the hypothesis that age-1 northern pike and stocked muskellunge segregate and have different habitat affinities. Water depth, temperature, substrate and aquatic vegetation variables were estimated for each muskellunge (n = 103) and northern pike (n = 131) position and nested ANOVA comparisons by species indicated differences in habitat use. Muskellunge exhibited a greater displacement from the release point and used habitat in shallower water depths (mean = 0.85 m, SE = 0.10) than northern pike (mean = 1.45 m, SE = 0.08). Both principal components analysis (PCA) and principal components ordination (PCO) were used to interpret underlying gradients relative to fish positions in two-dimensional space. Our analysis indicated that a separation of age-1 northern pike and muskellunge occurred 7 d post-release. This first principal component explained 48% of the variation in habitat use. Northern pike locations were associated with deeper habitats that generally had softer silt substrates and dense submersed vegetation. Muskellunge locations post-acclimation showed greater association with shallower habitats containing firmer sandy and clay substrates and emergent vegetation. The observed differences in habitat use suggest that fine-scale ecological separation occurred between these stocked muskellunge and wild northern pike, but small sample sizes and potential for individual variation limit extension of these conclusions. Further research is needed to determine if these patterns exist between larger samples of fishes over a greater range of habitats.

  14. Development of a System-wide Predator Control Program: Stepwise Implementation of a Predation Index, Predator Control Fisheries, and Evaluation Plan in the Columbia River Basin; Northern Pikeminnow Management Program, 1998 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Young, Franklin R.; Wachtel, Mark L.; Petersen, Marc R.

    2003-03-01

    We are reporting on the progress of the Northern Pikeminnow Sport-Reward Fishery (NPSRF) in the lower Columbia and Snake rivers for 1998. The objectives of this project were to (1) implement a sport fishery that rewards anglers who harvest northern pikeminnow Ptychocheilus oregonensis {ge}279 mm (11 inches) total length, (2) collect catch data on selected fish species caught by fishery participants while targeting northern pikeminnow, (3) monitor and report incidental catch of sensitive salmonid species by anglers targeting northern pikeminnow and, (4) collect, monitor and report data on angler participation, catch and catch per angler day of northern pikeminnow during the season. A total of 108,903 northern pikeminnow {ge}279 mm were harvested during the 1998 season and 21,959 angler days were spent harvesting these fish. Harvest was below the seven year average of 150,874 and participation was well below the seven-year average of 51,013 angler days. Catch per angler day for all anglers during the season was 4.96 and exceeded the seven-year average of 2.96 northern pikeminnow per angler day. Peamouth Mylocheilus caurinus, and white sturgeon Acipencer transmontanus, were the other species most often harvested by returning NPSRF anglers targeting northern pikeminnow. Harvest of salmonids Oncorhynchus spp. by NPSRF anglers targeting northern pikeminnow remained below limits established by the National Marine Fisheries Service (NMFS).

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

    Science.gov (United States)

    Planert, Michael

    2007-01-01

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

  16. CEPF Western Ghats Special Series: Freshwater fish fauna of Krishna River at Wai, northern Western Ghats, India

    Directory of Open Access Journals (Sweden)

    S.S. Kharat

    2012-06-01

    Full Text Available Freshwater fish fauna of the Krishna River at Wai, and the Dhom reservoir upstream of Wai, was studied. Fifty one species belonging to 14 families and 33 genera were recorded; 13 endemic to the Western Ghats and two to the Krishna River system. Moderate to rare populations were found for six globally threatened species: Gonoproktopterus curmuca, Labeo potail, Schismatorhynchos nukta, Tor khudree, T. mussullah and Parapsilorhynchus discophorus. Fish in this area are under threat due to two introduced species and five transplanted species, and due to other anthropogenic activities such as overfishing and organic and inorganic pollution of the river. Site based conservation action plans are needed for conservation of rare and threatened fish in this area.

  17. Contribution of river floods, hurricanes, and cold fronts to elevation change in a deltaic floodplain, northern Gulf of Mexico, USA

    Science.gov (United States)

    Bevington, Azure E.; Twilley, Robert R.; Sasser, Charles E.; Holm, Guerry O.

    2017-05-01

    Deltas are globally important locations of diverse ecosystems, human settlement, and economic activity that are threatened by reductions in sediment delivery, accelerated sea level rise, and subsidence. Here we investigated the relative contribution of river flooding, hurricanes, and cold fronts on elevation change in the prograding Wax Lake Delta (WLD). Sediment surface elevation was measured across 87 plots, eight times from February 2008 to August 2011. The high peak discharge river floods in 2008 and 2011 resulted in the greatest mean net elevation gain of 5.4 to 4.9 cm over each flood season, respectively. The highest deltaic wetland sediment retention (13.5% of total sediment discharge) occurred during the 2008 river flood despite lower total and peak discharge compared to 2011. Hurricanes Gustav and Ike resulted in a total net elevation gain of 1.2 cm, but the long-term contribution of hurricane derived sediments to deltaic wetlands was estimated to be just 22% of the long-term contribution of large river floods. Winter cold front passage resulted in a net loss in elevation that is equal to the elevation gain from lower discharge river floods and was consistent across years. This amount of annual loss in elevation from cold fronts could effectively negate the long-term land building capacity within the delta without the added elevation gain from both high and low discharge river floods. The current lack of inclusion of cold front elevation loss in most predictive numerical models likely overestimates the land building capacity in areas that experience similar forcings to WLD.

  18. From regionally predictable to locally complex population structure in a freshwater top predator: River systems are not always the unit of connectivity in Northern Pike Esox lucius

    DEFF Research Database (Denmark)

    Bekkevold, Dorte; Jacobsen, Lene; Hansen, Jakob Hemmer;

    2015-01-01

    Contemporary genetic diversity is the product of both historical and contemporary forces, such as climatic and geological processes affecting range distribution and continuously moulded by evolutionary forces selection, gene flow and genetic drift. Predatory freshwater fishes, such as Northern Pike...... Esox lucius, commonly exhibit small population sizes, and several local populations are considered endangered. Pike inhabit diverse habitat types, including lakes, rivers and brackish marine waters, thus spanning from small isolated patches to large open marine systems. However, pike population...... structure from local to regional scales is relatively poorly described, in spite of its significance to developing conservation measures. We analysed microsatellite variation in a total of 1185 North European pike from 46 samples collected across both local and regional scales, as well as over time...

  19. Contributions of the different water sources to the Elqui river runoff (northern Chile) evaluated by H/O isotopes.

    Science.gov (United States)

    Strauch, Gerhard; Oyarzun, Jorge; Fiebig-Wittmaack, Melitta; González, Edmundo; Weise, Stephan M

    2006-09-01

    We present the results of an isotope (2H and 18O) and hydrogeochemical study in order to constrain the origin, recharge, and evolution of the surface and groundwater in the arid Andean realm of the Elqui watershed. The results of 2H and18O analyses of water samples obtained during our summer and winter campaigns indicate a generally meteoric origin of the river and spring waters of the watershed. The isotope signature of water of the Elqui river and its tributaries as well as that of groundwater in the coastal region fits the 2H-18O relation of delta2H =7.61delta18O+6.1. A relatively fast discharge and a quasi-closed catchment area can be asserted for water along the river flow path. The tributaries from the more arid coastal area, north of the Elqui river, differ in their isotopic signature due to evaporation and hydrochemically due to interactions with the strongly altered and fractured volcanic rocks of the basement. In the Andean zone, the18O-enriched hydrothermal spring of Baños del Toro exhibits the influence of water-rock interaction processes. The chemistry of the river water changes from sulphate- to chloride-rich along the river course from the high Andean mountains to the coast. The sulphate-rich character of these Andean waters reflects their passage through sulphide-rich rock massifs that were subjected to strong oxidation processes in the near superficial environment. This sulphate signature is enforced by past and present mining of precious metal epithermal deposits (e.g. those of El Indio-Tambo Au-Cu-As district), in which mineralised zones were developed during a series of Miocene magmatic-hydrothermal episodes in the Andean realm. Owing to the proximity of the lower Elqui river waters and its tributaries to the Pacific coast, the chloride character may be induced by agricultural and marine (sea spray, fog) sources. Generally, the main source of the Elqui river water is mainly attributed to surface runoff and less to contributions from the

  20. The exchange of energy, water and carbon dioxide between wet arctic tundra and the atmosphere at the Lena River Delta, Northern Siberia

    Energy Technology Data Exchange (ETDEWEB)

    Kutzbach, L.

    2006-07-01

    The ecosystem-scale exchange fluxes of energy, water and carbon dioxide between wet arctic tundra and the atmosphere were investigated by the micrometeorological eddy covariance method. The investigation site was the centre of the Lena River Delta in Northern Siberia characterised by a polar and distinctly continental climate, very cold and ice-rich permafrost and its position at the interface between the Eurasian continent and the Arctic Ocean. The measurements were performed on the surface of a Holocene river terrace characterised by wet polygonal tundra. The soils at the site are characterised by high organic matter content, low nutrient availability and pronounced water logging. The vegetation is dominated by sedges and mosses. The fluctuations of the H{sub 2}O and CO{sub 2} concentrations were measured with a closed-path infrared gas analyser. The fast-response eddy covariance measurements were supplemented by a set of slow-response meteorological and soil-meteorological measurements. The combined datasets of the two campaigns 2003 and 2004 were used to characterise the seasonal course of the energy, water and CO{sub 2} fluxes and the underlying processes for the synthetic measurement period May 28..October 21 2004/2003 including the period of snow and soil thawing as well as the beginning of refreezing. The synthetic measurement period 2004/2003 was characterised by a long snow ablation period and a late start of the growing season. On the other hand, the growing season ended also late due to high temperatures and snow-free conditions in September. The cumulative summer energy partitioning was characterised by low net radiation, large ground heat flux, low latent heat flux and very low sensible heat flux compared to other tundra sites. These findings point out the major importance of the very cold permafrost for the summer energy budget of the tundra in Northern Siberia. (orig./SR)

  1. Development of a System-Wide Predator Control Program: Stepwise Implementation of a Predation Index, Predator Control Fisheries, and Evaluation Plan in the Columbia River Basin; Northern Pikeminnow Management Program, 2001 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Porter, Russell G.; Winther, Eric C.; Fox, Lyle G.

    2003-03-01

    This report presents results for year eleven in a basin-wide program to harvest northern pikeminnow (Ptychocheilus oregonensis). This program was started in an effort to reduce predation by northern pikeminnow on juvenile salmonids during their emigration from natal streams to the ocean. Earlier work in the Columbia River Basin suggested predation by northern pikeminnow on juvenile salmonids might account for most of the 10-20% mortality juvenile salmonids experience in each of eight Columbia River and Snake River reservoirs. Modeling simulations based on work in John Day Reservoir from 1982 through 1988 indicated that, if predator-size northern pikeminnow were exploited at a 10-20% rate, the resulting restructuring of their population could reduce their predation on juvenile salmonids by 50%. To test this hypothesis, we implemented a sport-reward angling fishery and a commercial longline fishery in the John Day Pool in 1990. We also conducted an angling fishery in areas inaccessible to the public at four dams on the mainstem Columbia River and at Ice Harbor Dam on the Snake River. Based on the success of these limited efforts, we implemented three test fisheries on a system-wide scale in 1991--a tribal longline fishery above Bonneville Dam, a sport-reward fishery, and a dam-angling fishery. Low catch of target fish and high cost of implementation resulted in discontinuation of the tribal longline fishery. However, the sport-reward and dam-angling fisheries were continued in 1992 and 1993. In 1992, we investigated the feasibility of implementing a commercial longline fishery in the Columbia River below Bonneville Dam and found that implementation of this fishery was also infeasible.

  2. The characteristics of consolidation settlement and its contribution to the topographical change in the northern modern Huanghe River subaqueous delta in China

    Institute of Scientific and Technical Information of China (English)

    LIU Jie; LI Ping; LIU Xiao; XU Yuanqin; GAO Wei

    2015-01-01

    The sediments of the modern Huanghe River subaqueous delta are easily to generate settlement and lead to topography change which is due to fast deposition rate, high void ratio, moisture content and compressibility. The sediment consolidation settlements and its contribution to the topography change in the northern modern Huanghe River subaqueous delta are studied based on drilling data, laboratory experiment results, and water depth measurements of different time. The results show that the final consolidation settlement of drill holes in the study area is between 1.17 and 3.21 m, and mean settlement of unit depth is between 2.30 and 5.30 cm/m based on the one-dimensional consolidation theory and Plaxis numerical model. The final consolidation settlement obtained by Plaxis numerical model is smaller than that obtained by the one-dimensional consolidation theory, and the difference is 3.4%–39.9%between the methods. The contribution of the consolidation settlement to the topographical change is at 20.2%–86.6%, and the study area can be divided into five different regions based on different contribution rates. In the erosion area, the actual erosion depth caused by hydrodynamics is lower than the changes of measured water depth, however, the actual deposition amount caused by hydrodynamics is much larger than the changes of water depth obtained by measured data in the equilibrium and deposition areas.

  3. Movements and Distribution of Northern Squawfish Downstream of Lower Snake River Dams Relative to the Migration of Juvenile Salmonids, 1992-1993 Completion Report.

    Energy Technology Data Exchange (ETDEWEB)

    Isaak, D.J.; Bjornn, T.C. (University of Idaho, Idaho Cooperative Fish and Wildlife Research Unit, Moscow, ID)

    1996-03-01

    Northern squawfish Ptychocheilus oregonensis movements were monitored downstream of two lower Snake River dams during the juvenile salmonid migrations of 1992 and 1993. During a high flow year in 1993, the abundance of squawfish in the tailrace of Lower Granite Dam peaked in July, after the majority of juveniles had moved past Lower Granite Dam, and peak abundance was inversely related to river discharge. Few squawfish moved into the tailrace of Ice Harbor Dam in 1993 because of the extended period of spill. Distributions of squawfish in the tailrace of Lower Granite Dam varied between and within years and shifted in response to changing prey densities, flow patterns, water temperature, and diel cycles, but fish consistently used low velocity habitats. Data from Ice Harbor Dam is less extensive, but squawfish distributions there appeared to be affected by changing flow patterns and fish used low velocity habitats. The changes in distribution and abundance of squawfish in tailrace areas are evidence that predation on seaward migrating salmonids depends on the timing of migration and size and timing of runoff. Juvenile salmonids migrating in the spring and early summer will probably be less affected by squawfish predation in tailrace areas than salmon that migrate later in the summer.

  4. [Karyological differences of the Northern Dolly Varden Salvelinus malma malma and the white char Salvelinus albus from the Kamchatka River basin].

    Science.gov (United States)

    Frolov, S V

    2001-03-01

    The karyotypes of northern Dolly Varden and white char, sympathrically inhabiting the Kamchatka River basin, were studied. The karyotype of Dolly Varden was stable: 2n = 78 and NF = 98 + 2, while in white char, polymorphism and mosaicism for the chromosome number were revealed: 2n = 76-79, NF = 98 + 2. Using a routine chromosome staining technique, the karyotype of white char (2n = 78) was shown to be identical to that of Dolly Varden. In both karyotypes, similar sets of marker chromosomes were present: two pairs of submetacentric (SM), one pair of submeta-subtelocentric (SM-ST), one pair of large acrocentric (A), and one pair of large sub-telocentric (ST) chromosomes. However, the karyotypes of Dolly Varden and white char differed in the number and location of nucleolus organizer regions (NORs). In Dolly Varden, single NORs located in the telomeric regions of the marker SM-ST chromosomes were observed. In white char, NORs were multiple and located both in the telomeric regions of the marker SM-ST chromosomes and on the short and long arms of large ST chromosomes. The identical marker chromosomes indicate considerable phylogenetic relatedness between Dolly Varden and white char from the Kamchatka River basin. Variation in NORs provides evidence for the reproductive isolation of these chars and their species status.

  5. Insights on the opening of the Galerian mammal migration pathway from magnetostratigraphy of the Pleistocene marine-continental transition in the Arda River section (northern Italy)

    Science.gov (United States)

    Monesi, Edoardo; Muttoni, Giovanni; Scardia, Giancarlo; Felletti, Fabrizio; Bona, Fabio; Sala, Benedetto; Tremolada, Fabrizio; Francou, Carlo; Raineri, Gianluca

    2016-09-01

    We investigated the magnetostratigraphy of the Arda River section (northern Italy) where the transition from marine to continental sedimentation occurring in the Po River basin during the Pleistocene is registered. Four magnetic polarity reversals were used to construct an age model of sedimentation aided by marine biostratigraphy and tied to a standard δ18O curve from the literature. The section spans from the Olduvai subchron (1.94-1.78 Ma) across the Jaramillo subchron (1.07-0.99 Ma) up to the Brunhes-Matuyama boundary (0.78 Ma). The onset of continental deposition occurred during marine isotope stage (MIS) 30 at ˜1.04 Ma. An association of Villafranchian and Early Galerian mammals, including Sus strozzii and Ursus dolinensis, has been found in the continental sediments dated to MIS 29-27 (˜0.99 Ma). Above follows a prominent fluvial conglomerate attributed to the first major lowstand of the Pleistocene culminating with MIS 22 at ˜0.9 Ma during the late Early Pleistocene climate turnover (EPT). These and other data from the literature are used to reconstruct the onset of continental deposition in the greater Po basin and shed light on the opening of the migration pathway that brought far-traveled Galerian mammal immigrants to enter Europe for the first time during the EPT.

  6. Using Coupled Models to Study the Effects of River Discharge on Biogeochemical Cycling and Hypoxia in the Northern Gulf of Mexico

    Science.gov (United States)

    Penta, Bradley; Ko, D.; Gould, Richard W.; Arnone, Robert A.; Greene, R.; Lehrter, J.; Hagy, James; Schaeffer, B.; Murrell, M.; Kurtz, J.; Herchenroder, B.; Green, R.; Eldridge, P.

    2009-01-01

    We describe emerging capabilities to understand physical processes and biogeoehemical cycles in coastal waters through the use of satellites, numerical models, and ship observations. Emerging capabilities provide significantly improved ability to model ecological systems and the impact of environmental management actions on them. The complex interaction of physical and biogeoehemical processes responsible for hypoxic events requires an integrated approach to research, monitoring, and modeling in order to fully define the processes leading to hypoxia. Our efforts characterizes the carbon cycle associated with river plumes and the export of organic matter and nutrients form coastal Louisiana wetlands and embayments in a spatially and temporally intensive manner previously not possible. Riverine nutrients clearly affect ecosystems in the northern Gulf of Mexico as evidenced in the occurrence of regional hypoxia events. Less known and largely unqualified is the export of organic matter and nutrients from the large areas of disappearing coastal wetlands and large embayments adjacent to the Louisiana Continental Shelf. This project provides new methods to track the river plume along the shelf and to estimate the rate of export of suspended inorganic and organic paniculate matter and dissolved organic matter form coastal habitats of south Louisiana.

  7. Physical processes of thermokarst lakes in the continuous permafrost zone of northern Siberia – observations and modeling (Lena River Delta, Siberia

    Directory of Open Access Journals (Sweden)

    J. Boike

    2015-04-01

    Full Text Available The thermal regimes of five lakes located within the continuous permafrost zone of northern Siberia (Lena River Delta have been investigated using hourly water temperature and water level records covering a three year period (2009–2012, together with bathymetric survey data. The lakes included thermokarst lakes located on Holocene river terraces that may be connected to Lena River water during spring flooding, and a thermokarst lake located on deposits of the Pleistocene Ice Complex. The data were used for numerical modeling with FLake software, and also to determine the physical indices of the lakes. The lakes vary in area, depths and volumes. The winter thermal regime is characterized by an ice cover up to 2 m thick that survives for more than 7 months of the year, from October until about mid-June. Lake-bottom temperatures increase at the start of the ice-covered period due to upward-directed heat flux from the underlying thawed sediment. The effects of solar radiation return prior to ice break-up, effectively warming the water beneath the ice cover and inducing convective mixing. Ice break-up starts the beginning of June and takes until the middle or end of June for completion. Mixing occurs within the entire water column from the start of ice break-up and continues during the ice-free periods, as confirmed by the Wedderburn numbers. Some of the lakes located closest to the Lena River are subjected to varying levels of spring flooding with river water, on an annual basis. Numerical modeling using FLake software indicates that the vertical heat flux across the bottom sediment tends towards an annual mean of zero, with maximum downward fluxes of about 5 W m−2 in summer and with heat released back into the water column at a~rate of less than 1 W m−2 during the ice-covered period. The lakes are shown to be efficient heat absorbers and effectively distribute the heat through mixing. Monthly bottom water temperatures during the ice

  8. How significant is submarine groundwater discharge and its associated dissolved inorganic carbon in a river-dominated shelf system-the northern South China Sea?

    Directory of Open Access Journals (Sweden)

    Q. Liu

    2011-12-01

    Full Text Available In order to assess the role of submarine groundwater discharge (SGD and its impact on the carbonate system on the northern South China Sea (NSCS shelf, we measured seawater concentrations of four radium isotopes 223,224,226,228Ra along with carbon dioxide parameters in June–July, 2008. Complementary groundwater sampling was conducted in coastal areas in December 2008 and October 2010 to constrain the groundwater end-members. The distribution of Ra isotopes in the NSCS was largely controlled by the Pearl River plume and coastal upwelling. Long-lived Ra isotopes (228Ra and 226Ra were enriched in the river plume but low in the offshore surface water and subsurface water/upwelling zone. In contrast, short-lived Ra isotopes (224Ra and 223Ra were elevated in the subsurface water/upwelling zone as well as the river plume but depleted in the offshore surface water. In order to quantify SGD, we adopted two independent mathematical approaches. Using a three end-member mixing model with total alkalinity (TAlk and Ra isotopes, we derived a SGD flux into the NSCS shelf of 2.3–3.7 ×108 m3 d−1. Our second approach involved a simple mass balance of 228Ra and 226Ra and resulted in a first order but consistent SGD rate estimate of 2.8–4.5 × 108 m3 d−1. These fluxes were equivalent to 13–25 % of the Pearl River discharge, but the source of the SGD is mostly recirculated seawater. Despite the relatively small SGD volume flow compared to the river, the associated material fluxes were substantial given the elevated concentrations of dissolved inorganic solutes. In this case, dissolved inorganic carbon (DIC flux through SGD was 266–520 × 109 mol yr−1, which was ~44–73 % of the riverine DIC export flux. Given our estimates of the groundwater-derived phosphate flux, SGD may be

  9. River

    Directory of Open Access Journals (Sweden)

    Morel Mathieu

    2016-01-01

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

  10. Impacts of climate change on river discharge in the northern Tien Shan: Results from the long-term observations and modelling

    Science.gov (United States)

    Shahgedanova, Maria; Afzal, Muhammad; Usmanova, Zamira; Kapitsa, Vasilii; Mayr, Elisabeth; Hagg, Wilfried; Severskiy, Igor; Zhumabayev, Dauren

    2017-04-01

    The study presents results of investigation of the observed and projected changes in discharge of seven snow- and glacier-nourished rivers of the northern Tien Shan (south-eastern Kazakhstan). The observed trends were assessed using the long-term (40-60 years) homogeneous daily records of discharge from the gauging stations located in the mountains and unaffected by human activities including water abstraction. Positive trends in discharge were registered at most sites between the 1950s and 2010s with the strongest increase in summer and autumn particularly in 2000-2010s in line with the positive temperature trends. The observed increase was most prominent in the catchments with a higher proportion of glacierized area. At the Ulken Almatinka and Kishi Almatinka rivers, where 16% and 12% of the catchment areas are glacierized, positive trends in summer and autumn discharge exceeded 1% per year. The strongest increase was observed in September indicating that melting period extends in the early autumn. In September-November, the number of days with extreme discharge values, defined as daily values exceeding 95th percentile (calculated for each meteorological season), increased at all rivers. Future changes in discharge were modelled using HBV-ETH hydrological model and four climate change scenarios derived using regional climate model PRECIS with 25 km spatial resolution driven by HadGEM GCM for RCP 2.6 and RCP 8.5 scenarios and HadCM3Q0 and ECHAM5 GCM for A1B scenario. A range of glacier change scenarios was considered. All climate experiments project increase in temperature with the strongest warming projected by the HadGEM-driven simulation for RCP 8.5 scenario and HadCM3Q0-driven simulation for A1B scenario. The projected changes in precipitation varied between models and seasons, however, most experiments did not show significant trends in precipitation within the studied catchments. The exception is a simulation driven by HadGEM GCM for 8.5 RCP scenario which

  11. Identification and antimicrobial resistance of Enterococcus spp. isolated from the river and coastal waters in northern Iran.

    Science.gov (United States)

    Alipour, Majid; Hajiesmaili, Reza; Talebjannat, Maryam; Yahyapour, Yousef

    2014-01-01

    As fecal streptococci commonly inhabit the intestinal tract of humans and warm blooded animals, and daily detection of all pathogenic bacteria in coastal water is not practical, thus these bacteria are used to detect the fecal contamination of water. The present study examined the presence and the antibiotic resistance patterns of Enterococcus spp. isolated from the Babolrud River in Babol and coastal waters in Babolsar. Seventy samples of water were collected in various regions of the Babolrud and coastal waters. Isolated bacteria were identified to the species level using standard biochemical tests and PCR technique. In total, 70 Enterococcus spp. were isolated from the Babolrud River and coastal waters of Babolsar. Enterococcus faecalis (68.6%) and Enterococcus faecium (20%) were the most prevalent species. Resistance to chloramphenicol, ciprofloxacin, and tetracyclin was prevalent. The presence of resistant Enterococcus spp. in coastal waters may transmit resistant genes to other bacteria; therefore, swimming in such environments is not suitable.

  12. Identification and Antimicrobial Resistance of Enterococcus Spp. Isolated from the River and Coastal Waters in Northern Iran

    Directory of Open Access Journals (Sweden)

    Majid Alipour

    2014-01-01

    Full Text Available As fecal streptococci commonly inhabit the intestinal tract of humans and warm blooded animals, and daily detection of all pathogenic bacteria in coastal water is not practical, thus these bacteria are used to detect the fecal contamination of water. The present study examined the presence and the antibiotic resistance patterns of Enterococcus spp. isolated from the Babolrud River in Babol and coastal waters in Babolsar. Seventy samples of water were collected in various regions of the Babolrud and coastal waters. Isolated bacteria were identified to the species level using standard biochemical tests and PCR technique. In total, 70 Enterococcus spp. were isolated from the Babolrud River and coastal waters of Babolsar. Enterococcus faecalis (68.6% and Enterococcus faecium (20% were the most prevalent species. Resistance to chloramphenicol, ciprofloxacin, and tetracyclin was prevalent. The presence of resistant Enterococcus spp. in coastal waters may transmit resistant genes to other bacteria; therefore, swimming in such environments is not suitable.

  13. Fluxes of dissolved organic carbon and nitrogen to the northern Indian Ocean from the Indian monsoonal rivers

    Digital Repository Service at National Institute of Oceanography (India)

    Krishna, M.S.; Prasad, V.R.; Sarma, V.V.S.S.; Reddy, N.P.C.; Hemalatha, K.P.J.; Rao, Y.V.

    [Bin and Longjun, 2011], domestic and industrial sewage, besides the input from autochthonous sources, such as phytoplankton [Carlson et al., 1994; Bianchi et al., 2004], bacteria and macrophytes [Bronk et al., 1994; Diaz and Raimbault, 2000... transport in the Columbia River, Estuar. Coast. Shelf Sci., 13, 645-658. Diaz, F., and P. Raimbault (2000), Nitrogen regeneration and dissolved organic nitrogen release during spring in a NW Mediterranean coastal zone (Gulf of Lions): implications...

  14. Mapping spatial patterns of stream power and channel change along a gravel-bed river in northern Yellowstone

    Science.gov (United States)

    Lea, Devin M.; Legleiter, Carl J.

    2016-01-01

    Stream power represents the rate of energy expenditure along a river and can be calculated using topographic data acquired via remote sensing or field surveys. This study sought to quantitatively relate temporal changes in the form of Soda Butte Creek, a gravel-bed river in northeastern Yellowstone National Park, to stream power gradients along an 8-km reach. Aerial photographs from 1994 to 2012 and ground-based surveys were used to develop a locational probability map and morphologic sediment budget to assess lateral channel mobility and changes in net sediment flux. A drainage area-to-discharge relationship and DEM developed from LiDAR data were used to obtain the discharge and slope values needed to calculate stream power. Local and lagged relationships between mean stream power gradient at median peak discharge and volumes of erosion, deposition, and net sediment flux were quantified via spatial cross-correlation analyses. Similarly, autocorrelations of locational probabilities and sediment fluxes were used to examine spatial patterns of sediment sources and sinks. Energy expended above critical stream power was calculated for each time period to relate the magnitude and duration of peak flows to the total volumetric change in each time increment. Collectively, we refer to these methods as the stream power gradient (SPG) framework. The results of this study were compromised by methodological limitations of the SPG framework and revealed some complications likely to arise when applying this framework to small, wandering, gravel-bed rivers. Correlations between stream power gradients and sediment flux were generally weak, highlighting the inability of relatively simple statistical approaches to link sub-budget cell-scale sediment dynamics to larger-scale driving forces such as stream power gradients. Improving the moderate spatial resolution techniques used in this study and acquiring very-high resolution data from recently developed methods in fluvial remote

  15. Microbial water quality during the northern migration of Sandhill Cranes (Grus canadensis) at the central Platte River, Nebraska

    Science.gov (United States)

    Moser, Matthew T.

    2014-01-01

    The central Platte River is an important resource in Nebraska. Its water flows among multiple channels and supports numerous beneficial uses such as drinking water, irrigation for agriculture, groundwater recharge, and recreational activities. The central Platte River valley is an important stopover for migratory waterfowl and cranes, such as the Whooping (Grus americana) and Sandhill Cranes (Grus canadensis), in their annual northward traversal of the Central Flyway. Waterfowl, cranes, and other migratory birds moving across international and intercontinental borders may provide long-range transportation for any microbial pathogen they harbor, particularly through the spread of feces. Samples were collected weekly in the study reach from three sites (upstream, middle, and downstream from the roosting locations) during the spring of 2009 and 2010. The samples were analyzed for avian influenza, Escherichia coli, Cryptosporidium, Giardia, Campylobacter, and Legionella. Analysis indicates that several types of fecal indicator bacteria and a range of viral, protozoan, and bacterial pathogens were present in Sandhill Crane excreta. These bacteria and pathogens were present at a significantly higher frequency and densities in water and sediments when the Sandhill Cranes were present, particularly during evening roosts within the Platte River environment.

  16. Colloidal size spectra, composition and estuarine mixing behavior of DOM in river and estuarine waters of the northern Gulf of Mexico

    Science.gov (United States)

    Zhou, Zhengzhen; Stolpe, Björn; Guo, Laodong; Shiller, Alan M.

    2016-05-01

    Flow field-flow fractionation (FlFFF) coupled on-line with UV absorbance and fluorescence detectors was used to examine the colloidal composition and size distribution of optically active dissolved organic matter (DOM) in the lower Mississippi River (MR), the East Pearl River (EPR), the St. Louis Bay (SLB) estuary, and coastal waters of the northern Gulf of Mexico. In addition to field studies, laboratory mixing experiments using river and seawater end-members were carried out to study the processes controlling the estuarine mixing behavior and size partitioning of colloids with different sizes and composition. The colloidal size spectra of chromophoric DOM and humic-like DOM showed one dominant peak in the 0.5-4 nm size range, representing >75% of the total FlFFF-recoverable colloids. In contrast, protein-like DOM showed a bi-modal distribution with peaks at 0.5-4 nm and 4-8 nm, as well as a major portion (from ∼41% in the EPR to ∼72% in the Mississippi Bight) partitioned to the >20 nm size fraction. Bulk DOM was lower in abundance and molecular-weight in the MR compared with the EPR, while the proportion of colloidal protein-like DOM in the >20 nm size range was slightly larger in the MR compared with the EPR. These features are consistent with differences in land use, hydrological conditions, and water residence time between the two river basins, with more autochthonous DOM in MR waters. In the SLB estuary, different DOM components demonstrated different mixing behaviors. The abundance of colloidal chromophoric DOM decreased with increasing salinity and showed evident removal during estuarine mixing even though the bulk DOM appeared to be conservative. In contrast, colloidal humic-like DOM behaved conservatively inside SLB and during laboratory mixing experiments. The ratio of colloidal protein-like to humic-like DOM generally increased with increasing salinity, consistent with increasing autochthonous protein-like DOM and removal of terrestrially

  17. Development of a System-Wide Predator Control Program: Stepwise Implementation of a Predation Index, Predator Control Fisheries, and Evaluation Plan in the Columbia River Basin; Northern Pikeminnow Management Program, 2002 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Porter, Russell G.; Winther, Eric C.; Fox, Lyle G.

    2004-01-01

    This report presents results for year twelve in a basin-wide program to harvest northern pikeminnow1 (Ptychocheilus oregonensis). This program was started in an effort to reduce predation by northern pikeminnow on juvenile salmonids during their emigration from natal streams to the ocean. Earlier work in the Columbia River Basin suggested predation by northern pikeminnow on juvenile salmonids might account for most of the 10-20% mortality juvenile salmonids experience in each of eight Columbia River and Snake River reservoirs. Modeling simulations based on work in John Day Reservoir from 1982 through 1988 indicated that, if predator-size northern pikeminnow were exploited at a 10-20% rate, the resulting restructuring of their population could reduce their predation on juvenile salmonids by 50%. To test this hypothesis, we implemented a sport-reward angling fishery and a commercial longline fishery in the John Day Pool in 1990. We also conducted an angling fishery in areas inaccessible to the public at four dams on the mainstem Columbia River and at Ice Harbor Dam on the Snake River. Based on the success of these limited efforts, we implemented three test fisheries on a system-wide scale in 1991--a tribal longline fishery above Bonneville Dam, a sport-reward fishery, and a dam-angling fishery. Low catch of target fish and high cost of implementation resulted in discontinuation of the tribal longline fishery. However, the sport-reward and dam-angling fisheries were continued in 1992 and 1993. In 1992, we investigated the feasibility of implementing a commercial longline fishery in the Columbia River below Bonneville Dam and found that implementation of this fishery was also infeasible. Estimates of combined annual exploitation rates resulting from the sport-reward and damangling fisheries remained at the low end of our target range of 10-20%. This suggested the need for additional effective harvest techniques. During 1991 and 1992, we developed and tested a modified

  18. A Groundwater flow Model of the Colorado River Delta to Support Riparian Habitat Restoration in Northern Mexico

    Science.gov (United States)

    Maddock, T.; Feirstein, E.; Baird, K. J.; Ajami, H.

    2007-05-01

    Quantification of groundwater flow dynamics and of the interactions among groundwater, surface water, and riparian vegetation, represent key components in the development of a balanced restoration plan for functional riparian ecosystems. A groundwater model was developed using MODFLOW 2000 to support of riparian restoration along the Colorado River Delta (Mexico: Baja California, Sonora). The Colorado River is widely recognized as one of the most modified and allocated rivers in the United States. For over 50 years flows into the Delta were severely reduced by the requirements of an emergent American West. However, subsequent to discharge pulses associated with the filling of Lake Powell, and the increased precipitation that accompanied ENSO cycles, a semblance of a native riparian habitat has been observed in the Delta since the 1980's (Zamora- Arroyo et al. 2001). The Delta and the riparian ecosystems of the region have since become the focus of a substantial body of multidisciplinary research. The research goal is to understand water table dynamics with particular attention to stream-aquifer interactions and groundwater behavior in the root zone. Groundwater reliant transpiration requirements were quantified for a set of dominant native riparian species using the Riparian ET (RIP-ET) package, an improved MODFLOW evapotranspiration (ET) module. RIP-ET simulates ET using a set of eco-physiologically based curves that more accurately represents individual plant species, reflects habitat complexity, and deals spatially with plant and water table distribution. When used in conjunction with a GIS based postprocessor (RIP-GIS.net), RIP-ET provides the basis for mapping groundwater conditions as they relate to user-specified plant groups. This explicit link between groundwater and plant sustainability is a driver to restoration design and allows for scenario modeling of various hydrologic conditions. Groundwater requirements determined in this research will be used by

  19. Landscape pattern of seed banks and anthropogenic impacts in forested wetlands of the northern Mississippi River Alluvial Valley

    Science.gov (United States)

    Middleton, B.; Wu, X.B.

    2008-01-01

    Agricultural development on floodplains contributes to hydrologic alteration and forest fragmentation, which may alter landscape-level processes. These changes may be related to shifts in the seed bank composition of floodplain wetlands. We examined the patterns of seed bank composition across a floodplain watershed by looking at the number of seeds germinating per m2 by species in 60 farmed and intact forested wetlands along the Cache River watershed in Illinois. The seed bank composition was compared above and below a water diversion (position), which artificially subdivides the watershed. Position of these wetlands represented the most variability of Axis I in a Nonmetric Multidimensional Scaling (NMS) analysis of site environmental variables and their relationship to seed bank composition (coefficient of determination for Axis 1: r2 = 0.376; Pearson correlation of position to Axis 1: r = 0.223). The 3 primary axes were also represented by other site environmental variables, including farming status (farmed or unfarmed), distance from the mouth of the river, latitude, and longitude. Spatial analysis based on Mantel correlograms showed that both water-dispersed and wind/water-dispersed seed assemblages had strong spatial structure in the upper Cache (above the water diversion), bur the spatial structure of water-dispersed seed assemblage was diminished in the lower Cache (below the water diversion), which lost floodpulsing. Bearing analysis also Suggested that water-dispersal process had a stronger influence on the overall spatial pattern of seed assemblage in the upper Cache, while wind/water-dispersal process had a stronger influence in the lower Cache. An analysis of the landscapes along the river showed that the mid-lower Cache (below the water diversion) had undergone greater land cover changes associated with agriculture than did the upper Cache watershed. Thus, the combination of forest fragmentation and hydrologic changes in the surrounding landscape may

  20. Observed impacts of duration and seasonality of atmospheric-river landfalls on soil moisture and runoff in coastal northern California

    Science.gov (United States)

    Ralph, F.M.; Coleman, T.; Neiman, P.J.; Zamora, R.J.; Dettinger, Mike

    2013-01-01

    This study is motivated by diverse needs for better forecasts of extreme precipitation and floods. It is enabled by unique hourly observations collected over six years near California’s Russian River and by recent advances in the science of atmospheric rivers (ARs). This study fills key gaps limiting the prediction of ARs and, especially, their impacts by quantifying the duration of AR conditions and the role of duration in modulating hydrometeorological impacts. Precursor soil moisture conditions and their relationship to streamflow are also shown. On the basis of 91 well-observed events during 2004-10, the study shows that the passage of ARs over a coastal site lasted 20 h on average and that 12% of the AR events exceeded 30 h. Differences in storm-total water vapor transport directed up the mountain slope contribute 74% of the variance in storm-total rainfall across the events and 61% of the variance in storm-total runoff volume. ARs with double the composite mean duration produced nearly 6 times greater peak streamflow and more than 7 times the storm-total runoff volume. When precursor soil moisture was less than 20%, even heavy rainfall did not lead to significant streamflow. Predicting which AR events are likely to produce extreme impacts on precipitation and runoff requires accurate prediction of AR duration at landfall and observations of precursor soil moisture conditions.

  1. Nitrogen budget in a lowland coastal area within the Po River basin (northern Italy): multiple evidences of equilibrium between sources and internal sinks.

    Science.gov (United States)

    Castaldelli, Giuseppe; Soana, Elisa; Racchetti, Erica; Pierobon, Enrica; Mastrocicco, Micol; Tesini, Enrico; Fano, Elisa Anna; Bartoli, Marco

    2013-09-01

    Detailed studies on pollutants genesis, path and transformation are needed in agricultural catchments facing coastal areas. Here, loss of nutrients should be minimized in order to protect valuable aquatic ecosystems from eutrophication phenomena. A soil system N budget was calculated for a lowland coastal area, the Po di Volano basin (Po River Delta, Northern Italy), characterized by extremely flat topography and fine soil texture and bordering a network of lagoon ecosystems. Main features of this area are the scarce relevance of livestock farming, the intense agriculture, mainly sustained by chemical fertilizers, and the developed network of artificial canals with long water residence time. Average nitrogen input exceeds output terms by ~60 kg N ha(-1) year(-1), a relatively small amount if compared to sub-basins of the same hydrological system. Analysis of dissolved inorganic nitrogen in groundwater suggests limited vertical loss and no accumulation of this element, while a nitrogen mass balance in surface waters indicates a net and significant removal within the watershed. Our data provide multiple evidences of efficient control of the nitrogen excess in this geographical area and we speculate that denitrification in soil and in the secondary drainage system performs this ecosystemic function. Additionally, the significant difference between nitrogen input and nitrogen output loads associated to the irrigation system, which is fed by the N-rich Po River, suggests that this basin metabolizes part of the nitrogen excess produced upstream. The traditionally absent livestock farming practices and consequent low use of manure as fertilizer pose the risk of excess soil mineralization and progressive loss of denitrification capacity in this area.

  2. The carbon dioxide system on the Mississippi River-dominated continental shelf in the northern Gulf of Mexico: 1. Distribution and air-sea CO2 flux.

    Science.gov (United States)

    Huang, Wei-Jen; Cai, Wei-Jun; Wang, Yongchen; Lohrenz, Steven E; Murrell, Michael C

    2015-03-01

    River-dominated continental shelf environments are active sites of air-sea CO2 exchange. We conducted 13 cruises in the northern Gulf of Mexico, a region strongly influenced by fresh water and nutrients delivered from the Mississippi and Atchafalaya River system. The sea surface partial pressure of carbon dioxide (pCO2) was measured, and the air-sea CO2 flux was calculated. Results show that CO2 exchange exhibited a distinct seasonality: the study area was a net sink of atmospheric CO2 during spring and early summer, and it was neutral or a weak source of CO2 to the atmosphere during midsummer, fall, and winter. Along the salinity gradient, across the shelf, the sea surface shifted from a source of CO2 in low-salinity zones (0≤S<17) to a strong CO2 sink in the middle-to-high-salinity zones (17≤S<33), and finally was a near-neutral state in the high-salinity areas (33≤S<35) and in the open gulf (S≥35). High pCO2 values were only observed in narrow regions near freshwater sources, and the distribution of undersaturated pCO2 generally reflected the influence of freshwater inputs along the shelf. Systematic analyses of pCO2 variation demonstrated the importance of riverine nitrogen export; that is, riverine nitrogen-enhanced biological removal, along with mixing processes, dominated pCO2 variation along the salinity gradient. In addition, extreme or unusual weather events were observed to alter the alongshore pCO2 distribution and to affect regional air-sea CO2 flux estimates. Overall, the study region acted as a net CO2 sink of 0.96 ± 3.7 mol m(-2) yr(-1) (1.15 ± 4.4 Tg C yr(-1)).

  3. The Early Callovian genus Cadochamoussetia (Ammonoidea, Cardioceratidae) in the lower reaches of the Anabar River, Northern Central Siberia

    Science.gov (United States)

    Kniazev, V. G.; Meledina, S. V.; Alifirov, A. S.; Nikitenko, B. L.

    2017-07-01

    The species Cadochamoussetia aff. subpatruus (Nik.), Cadochamoussetia surensis (Nik.), and Cadoceras cf. simulans Spath are found for the first time in the lower reaches of the Anabar River. The first two species are characteristic of the Lower Callovian Cadochamoussetia subpatruus Subzone of Central Russia, which is equivalent to the Siberian Cadochamoussetia tschernyschewi Zone. Species of the genus Cadochamoussetia, found for the first time in the Arctic, are described. Shells of Siberian representatives of Cadochamoussetia are distinguished from the typical East European species by their larger umbilicus, which is similar to that of the ancestral genus Cadoceras. It is suggested that the Siberian taxa belong to the oldest representatives of this genus, which appeared in the early Callovian Arctic seas and later migrated to seas of Central Europe and England.

  4. Instream coliform gradients in the Holtemme, a small headwater stream in the Elbe River Basin, Northern Germany

    Science.gov (United States)

    Karthe, Daniel; Lin, Pei-Ying; Westphal, Katja

    2017-09-01

    The Holtemme is a small headwater stream in North Germany's Elbe River Basin. According to German and European legislation, hygienic monitoring is not mandatory for such water bodies which are neither drinking water sources nor categorized as bathing waters. Consequently, relatively little is known about the occurrence of-potentially pathogenic-bacteria and viruses in Germany's streams and rivers. The Holtemme was selected for a case study because it is relatively well monitored for both chemical water quality and aquatic ecology, but not for hygiene. Originating in the mountains of Harz Nature Park, the 47 km long Holtemme is characterized by a strong longitudinal gradient in chemical water quality, which is related to different land uses and the influx of treated wastewater from two urban areas (Wernigerode and Halberstadt). Waste water loads received by the Holtemme are comparatively high when compared to similarly small streams. In 2015, total coliform concentrations between more than 200 and 77,010 bacteria per 100 mL, and fecal coliform concentrations between 5 and 24,060 bacteria per 100 mL were observed in the Holtemme's main channel. The highest concentrations were typically found below the outlets of the two wastewater treatment plants. The treated wastewater contained total and fecal coliform concentrations of up to 200,500 and 83,100 per 100 mL, respectively; however, there were significant temporal variations. While the observed concentrations are unproblematic from a legal perspective (because no maximum permissible limits are defined for streams in Germany), they would exceed the tolerable limits for bathing waters in the EU, indicating moderate to critical pollution limits.

  5. Development of a System-Wide Predator Control Program: Stepwise Implementation of a Predation Index, Predator Control Fisheries, and Evaluation Plan in the Columbia River Basin; Northern Pikeminnow Management Program, 2000 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Porter, Russell G.; Glaser, Bryce G.; Amren, Jennifer

    2003-03-01

    This report presents results for year ten in a basin-wide program to harvest northern pikeminnow (Ptychocheilus oregonensis). This program was started in an effort to reduce predation by northern pikeminnow on juvenile salmonids during their emigration from natal streams to the ocean. Earlier work in the Columbia River Basin suggested predation by northern pikeminnow on juvenile salmonids might account for most of the 10-20% mortality juvenile salmonids experience in each of eight Columbia River and Snake River reservoirs. Modeling simulations based on work in John Day Reservoir from 1982 through 1988 indicated that, if predator-size northern pikeminnow were exploited at a 10-20% rate, the resulting restructuring of their population could reduce their predation on juvenile salmonids by 50%. To test this hypothesis, we implemented a sport-reward angling fishery and a commercial longline fishery in the John Day Pool in 1990. We also conducted an angling fishery in areas inaccessible to the public at four dams on the mainstem Columbia River and at Ice Harbor Dam on the Snake River. Based on the success of these limited efforts, we implemented three test fisheries on a system-wide scale in 1991--a tribal longline fishery above Bonneville Dam, a sport-reward fishery, and a dam-angling fishery. Low catch of target fish and high cost of implementation resulted in discontinuation of the tribal longline fishery. However, the sport-reward and dam-angling fisheries were continued in 1992 and 1993. In 1992, we investigated the feasibility of implementing a commercial longline fishery in the Columbia River below Bonneville Dam and found that implementation of this fishery was also infeasible. Estimates of combined annual exploitation rates resulting from the sport-reward and damangling fisheries remained at the low end of our target range of 10-20%. This suggested the need for additional effective harvest techniques. During 1991 and 1992, we developed and tested a modified

  6. Can Continental Shelf River Plumes in the Northern and Southern Gulf of Mexico Promote Ecological Resilience in a Time of Climate Change?

    Directory of Open Access Journals (Sweden)

    G. Paul Kemp

    2016-03-01

    Full Text Available Deltas and estuaries built by the Mississippi/Atchafalaya River (MAR in the United States and the Usumacinta/Grijalva River (UGR in Mexico account for 80 percent of all Gulf of Mexico (GoM coastal wetlands outside of Cuba. They rank first and second in freshwater discharge to the GoM and owe their natural resilience to a modular geomorphology that spreads risk across the coast-scape while providing ecosystem connectivity through shelf plumes that connect estuaries. Both river systems generate large plumes that strongly influence fisheries production over large areas of the northern and southern GoM continental shelves. Recent watershed process simulations (DLEM, MAPSS driven by CMIP3 General Circulation Model (GCM output indicate that the two systems face diverging futures, with the mean annual discharge of the MAR predicted to increase 11 to 63 percent, and that of the UGR to decline as much as 80 percent in the 21st century. MAR delta subsidence rates are the highest in North America, making it particularly susceptible to channel training interventions that have curtailed a natural propensity to shift course and deliver sediment to new areas, or to refurbish zones of high wetland loss. Undoing these restrictions in a controlled way has become the focus of a multi-billion-dollar effort to restore the MAR delta internally, while releasing fine-grained sediments trapped behind dams in the Great Plains has become an external goal. The UGR is, from an internal vulnerability standpoint, most threatened by land use changes that interfere with a deltaic architecture that is naturally resilient to sea level rise. This recognition has led to successful efforts in Mexico to protect still intact coastal systems against further anthropogenic impacts, as evidenced by establishment of the Centla Wetland Biosphere Preserve and the Terminos Lagoon Protected Area. The greatest threat to the UGR system, however, is an external one that will be imposed by the

  7. New morpho-stratigraphic constraints for the evolution of the alluvial fan system along the northern slopes of the Taburno-Camposauro Mountains (Calore River basin, Southern Italy)

    Science.gov (United States)

    Leone, Natalia; Amato, Vincenzo; Aucelli, Pietro P. C.; Cesarano, Massimo; Filocamo, Francesca; Petrosino, Paola; Rosskopf, Carmen M.; Valente, Ettore; Giralt, Santiago; Casciello, Emilio

    2016-04-01

    The Lower Calore River Valley is a morphostructural depression located in the inner sector of the Campanian Apennine, between the Taburno-Camposauro and the Matese carbonate massifs. The river is the main left tributary of the Volturno River, it has a meandering channel partially structural-controlled. Numerous morphotectonic clues and historical seismicity data suggest that this part of the Apennine chain was particularly active during the late-Quaternary. In detail, the valley is E-W oriented and presents an asymmetry of the opposed valley slopes. The left side, corresponding to the northern flank of the Camposauro massif, is characterized by a steep slope (70°-35°), partially controlled by a ~E-W oriented fault system, and by a wide less-inclined piedmont aggradation zone. The latter started growing since middle Pleistocene, with the deposition of alluvial fans and slope deposits over the well cemented early Pleistocene breccias of Laiano Synthem. The alluvial fan deposition has been active until present giving rise to three main generations of alluvial fans. The right side of the valley, instead, is characterized by seven orders of fluvial terraces, both of erosional and depositional origin. The quaternary morpho-stratigraphic evolution of alluvial fans and fluvial terraces has been strongly conditioned by the interaction of tectonic phases and climatic variations. A detailed geomorphological study (1:5.000 in scale) was carried out with the aim to map the main depositional and erosional fluvial landforms and to identify the main tectonic lineaments of the area. A detailed field survey allowed to better define the stratigraphic and paleoenvironmental context in which the alluvial deposits developed and also to find chrono-stratigraphic markers. Tephra-stratigraphic analyses were performed on pyroclastic deposits interbedded into the alluvial fan and fluvial successions. At the moment the age of the first generation of alluvial fans is still under

  8. Nitrogen balance and fate in a heavily impacted watershed (Oglio River, Northern Italy: in quest of the missing sources and sinks

    Directory of Open Access Journals (Sweden)

    M. Bartoli

    2011-09-01

    Full Text Available We present data from a comprehensive investigation carried out from 2007 to 2010, focussing on nitrogen pollution in the lower Oglio River basin (3800 km2, Po plain, Northern Italy. Nitrogen mass balances, computed for the whole basin with 2000 and 2008 data, suggest a large N surplus in this area, over 40 000 t N yr−1, and increasing between 2000 and 2008. Calculations indicate a very large impact of animal husbandry and agricultural activities in this watershed, with livestock manure and synthetic fertilizers contributing 85 % of total N inputs (about 100 000 t N yr−1 and largely exceeding crop uptake and other N losses (about 60 000 t N yr−1. Nitrogen from domestic and industrial origin is estimated as about 5800 and 7200 t N yr−1, respectively, although these loads are overestimated, as denitrification in treatment plants is not considered; nonetheless, they represent a minor term of the N budget. Annual export of nitrogen from the basin, calculated from flow data and water chemistry at the mouth of the Oglio River, is estimated at 13 000 t N yr−1, and represents a relatively small fraction of N inputs and surplus (~12 % and 34 %, respectively. After considering N sinks in crop uptake, soil denitrification and volatilization, a large excess remains unaccounted (~26 000 t N yr−1 in unknown temporary or permanent N sinks. Nitrogen removal via denitrification was evaluated in the Oglio riverbed with stable isotope techniques (δ15N and δ18O in nitrate. The downstream final segment of the river displays an enriched nitrate stable isotope composition but calculations suggest a N removal corresponding to at most 12 % of the unaccounted for N amount. Denitrification was also evaluated in riverine wetlands with the isotope pairing technique. Areal rates are elevated but overall N removal is low (about 1 % of the missing N amount, due to

  9. Spatial distributions of polyunsaturated aldehydes and their biogeochemical implications in the Pearl River Estuary and the adjacent northern South China Sea

    Science.gov (United States)

    Wu, Zhengchao; Li, Qian P.

    2016-09-01

    This study reports the first comprehensive exploration of the spatial patterns of dissolved and particulate polyunsaturated aldehydes (PUAs), their physical and biological controlling factors, and their potential biogeochemical influences in the Pearl River Estuary (PRE) of the northern South China Sea (NSCS). High levels of total particulate PUAs (0-41 nM) and dissolved PUAs (0.10-0.37 nM) were observed with substantial spatial variation during an intense summer phytoplankton bloom outside the PRE mouth. We found the particulate PUAs strongly correlated with temperature within the high chlorophyll bloom, while showing a generally positive correlation with chlorophyll-a for the entire region. Additionally, the Si/N ratio significantly correlated with the particulate PUAs along the estuary suggesting the important role of silica on PUA production in this region. The dissolved PUAs counterparts exhibited a positive correlation with chlorophyll-a within the high chlorophyll bloom, but a negatively one with temperature outside, reflecting the essential bio-physical coupling effects on the dissolved PUAs distributions in the ocean. Biogeochemical implications of PUAs on the coastal ecosystem include not only the deleterious restriction of high PUAs-producing diatom bloom on copepod population, but also the profound influence of particulate PUAs on the microbial cycling of organic carbon in the NSCS.

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

    Energy Technology Data Exchange (ETDEWEB)

    Ojakangas, R.W.

    1979-10-01

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

  11. Three-dimensional water quality model based on FVCOM for total load control management in Guan River Estuary, Northern Jiangsu Province

    Science.gov (United States)

    Zhang, Li; Lin, Weibo; Li, Keqiang; Sheng, Jianming; Wei, Aihong; Luo, Feng; Wang, Yan; Wang, Xiulin; Zhang, Longjun

    2016-04-01

    Guan River Estuary and adjacent coastal area (GREC) suffer from serious pollution and eutrophicational problems over the recent years. Thus, reducing the land-based load through the national pollutant total load control program and developing hydrodynamic and water quality models that can simulate the complex circulation and water quality kinetics within the system, including longitudinal and lateral variations in nutrient and COD concentrations, is a matter of urgency. In this study, a three-dimensional, hydrodynamic, water quality model was developed in GREC, Northern Jiangsu Province. The complex three-dimensional hydrodynamics of GREC were modeled using the unstructured-grid, finite-volume, free-surface, primitive equation coastal ocean circulation model (FVCOM). The water quality model was adapted from the mesocosm nutrients dynamic model in the south Yellow Sea and considers eight compartments: dissolved inorganic nitrogen, soluble reactive phosphorus (SRP), phytoplankton, zooplankton, detritus, dissolved organic nitrogen (DON), dissolved organic phosphorus (DOP), and chemical oxygen demand. The hydrodynamic and water quality models were calibrated and confirmed for 2012 and 2013. A comparison of the model simulations with extensive dataset shows that the models accurately simulate the longitudinal distribution of the hydrodynamics and water quality. The model can be used for total load control management to improve water quality in this area.

  12. Mercury Distribution in the Deûle River (Northern France) Measured by the Diffusive Gradients in Thin Films Technique and Conventional Methods.

    Science.gov (United States)

    Diviš, Pavel; Kadlecová, Milada; Ouddane, Baghdad

    2016-05-01

    The distribution of mercury in surface water and in sediment from Deûle River in Northern France was studied by application of conventional sampling methods and by diffusive gradients in thin films technique (DGT). Concentration of total dissolved mercury in surface water was 20.8 ± 0.8 ng l(-1). The particulate mercury concentration was 6.2 ± 0.6 µg g(-1). The particulate mercury was accumulated in sediment (9.9 ± 2.3 mg kg(-1)), and it was transformed by methylating bacteria to methylmercury, mainly in the first 2-cm layer of the sediment. Total dissolved concentration of mercury in sediment pore water obtained by application of centrifugation extraction was 17.6 ± 4.1 ng l(-1), and it was comparable with total dissolved pore water mercury concentration measured by DGT probe containing Duolite GT-73 resin gel (18.2 ± 4.3 ng l(-1)), taking the sediment heterogeneity and different principles of the applied methods into account. By application of two DGT probes with different resin gels specific for mercury, it was found that approximately 30% of total dissolved mercury in sediment pore water was present in labile forms easy available for biota. The resolution of mercury DGT depth profiles was 0.5 cm, which allows, unlike conventional techniques, to study the connection of the geochemical cycle of mercury with geochemical cycles of iron and manganese.

  13. Element concentrations in the flesh and osteoderms of estuarine crocodiles (Crocodylus porosus) from the Alligator Rivers Region, Northern Australia: biotic and geographic effects.

    Science.gov (United States)

    Jeffree, R A; Markich, S J; Twining, J R

    2001-02-01

    The concentrations of Na, K, Ca, Mg, Ba, Sr, Fe, Al, Mn, Zn, Pb, Cu, Ni, Cr, Co, Se, U, and Ti were determined in the flesh and osteoderms of estuarine crocodiles (Crocodylus porosus) captured in three adjacent catchments of Kakadu National Park, within the Alligator Rivers Region of northern Australia. This study provides, for the first-time, baseline concentrations of elements in both flesh and osteoderms of wild crocodiles. Multiple linear regression analyses were used to determine the effects of total crocodile length, estimated age, gender, inferred reproductive status, physical condition, and catchment of capture on element concentrations in both tissues. The Mg concentration (log10) in the flesh and osteoderms of C. porosus significantly (p 0.05) effects of gender or inferred reproductive status on element concentrations in the flesh and osteoderms were found. The mean concentrations (log10) of Al, Ba, Cr, Ni, and Pb in flesh and Co, Fe, Mg, Mn, and U in the osteoderms were significantly (p crocodiles. They also point to the utility of crocodiles as long-term biomonitors of their environment.

  14. Distribution and mobility of heavy elements in floodplain agricultural soils along the Ibar River (Southern Serbia and Northern Kosovo). Chemometric investigation of pollutant sources and ecological risk assessment.

    Science.gov (United States)

    Barać, Nemanja; Škrivanj, Sandra; Bukumirić, Zoran; Živojinović, Dragana; Manojlović, Dragan; Barać, Milan; Petrović, Rada; Ćorac, Aleksandar

    2016-05-01

    This work investigates the influence of a high-magnitude flood event on heavy elements (HEs) pollution and mobility in the agricultural soils along Ibar River in Southern Serbia and Northern Kosovo. The study area was one of the most important Pb/Zn industrial regions in Europe. Soil samples (n = 50) collected before and after the floods in May 2014 were subjected to the sequential extraction procedure proposed by the Community Bureau of Reference (BCR). The results indicated that the floods significantly increased not only the pseudo total concentrations of HEs in the soil but also their mobile and potentially bioavailable amounts. Moreover, higher concentrations (both pseudo total and potentially bioavailable) were found in the agricultural soils closer to the industrial hotspots. Principal component analysis and hierarchical cluster analysis successfully grouped the analyzed elements according to their anthropogenic or natural origin. The floods significantly increased the potential ecological risk of HEs associated with Pb/Zn industrial activities in the study area. The potential ecological risk of Cd after the floods was highest and should be of special concern.

  15. Potential health hazards of the water resources development: a health survey in the Phitsanulok Irrigation Project, Nan River Basin, Northern Thailand.

    Science.gov (United States)

    Bunnag, T; Sornmani, S; Impand, P; Harinasuta, C

    1980-12-01

    A health survey was carried out among residents of 33 villages under the Phitsanulok Irrigation Project Area, Nan River Basin, Northern Thailand, whereby general health conditions were examined including intradermal tests for schistosomiasis japonica, stools for intestinal parasites and sera tested by circumoval precipitin test for antibodies to S. japonicum and by agglutination test for leptospiral infection. Health investigations revealed that 913 (60.9%) of 1,499 people examined had experienced gastro-intestinal disorders, 254 (17%) had poor oral hygiene and a few had mild anemia. 799 (62%) of 1,298 examined had intestinal parasites. Hookworm (45%) was most common, followed by Opisthorchis viverrini (20%), Entamoeba coli (10%), Ascaris lumbricoides (6%), intestinal flukes (2%), Enterobius vermicularis (1%) and Giardia lamblia (1%). 149 (10%) of 1,422 people gave positive skin reaction to crude S. japonicum antigen. Circumoval precipitin test was strongly positive in 7 (1.6%) persons out of 449 tested for schistosome infection and 6 (4.0%) out of 1,358 people were positive for leptospiral infection. The significant endemic diseases as potential health problems in this water resources development are discussed.

  16. The Mass Balance of Glacier No. 1 at the Headwaters of the Urumqi River in Relation to Northern Hemisphere Teleconnection Patterns

    Science.gov (United States)

    Yuan, Feifei; Hao, Zhenchun

    2017-04-01

    Most small glaciers in the world have significantly decreased their volume during the last century, which has caused water shortage problems. Glacier No. 1, at the headwaters of the Urumqi River, Tianshan, China, has been monitored since 1959 and similarly has experienced significant mass and volume losses over the last few decades. Thus, we examined the trend and potential abrupt changes of the mass balance of Glacier No. 1. Principal component analysis and singular value decomposition were used to find significant relations between the mass balance of Glacier No. 1 and Northern Hemisphere teleconnection patterns using climate indices. It was found that the mass balance of Glacier No. 1 had a significantly decreasing trend corresponding to -14.5 mm/year from 1959 to 2010. A change point was detected in 1997 with 99% confidence level. Two time periods with different mass balances were identified as 1959-1996 and 1997-2010. The mass balance for the first period was -136.4 mm/year and up to -663.9 mm/year for the second period. The mass balance of Glacier No. 1 is positively related to the Scandinavian Pattern (SCA), and negatively related to the East Atlantic Pattern (EA). These relationships are useful in better understanding the interaction between glacier mass balance and climate variability.

  17. The Mass Balance of Glacier No. 1 at the Headwaters of the Urumqi River in Relation to Northern Hemisphere Teleconnection Patterns

    Directory of Open Access Journals (Sweden)

    Feifei Yuan

    2016-03-01

    Full Text Available Most small glaciers in the world have significantly decreased their volume during the last century, which has caused water shortage problems. Glacier No. 1, at the headwaters of the Urumqi River, Tianshan, China, has been monitored since 1959 and similarly has experienced significant mass and volume losses over the last few decades. Thus, we examined the trend and potential abrupt changes of the mass balance of Glacier No. 1. Principal component analysis and singular value decomposition were used to find significant relations between the mass balance of Glacier No. 1 and Northern Hemisphere teleconnection patterns using climate indices. It was found that the mass balance of Glacier No. 1 had a significantly decreasing trend corresponding to −14.5 mm/year from 1959 to 2010. A change point was detected in 1997 with 99% confidence level. Two time periods with different mass balances were identified as 1959–1996 and 1997–2010. The mass balance for the first period was −136.4 mm/year and up to −663.9 mm/year for the second period. The mass balance of Glacier No. 1 is positively related to the Scandinavian Pattern (SCA, and negatively related to the East Atlantic Pattern (EA. These relationships are useful in better understanding the interaction between glacier mass balance and climate variability.

  18. Numerical groundwater flow modeling of the northern river catchment of the Lake Tana, Upper Blue Basin, Ethiopia

    Directory of Open Access Journals (Sweden)

    Nigussie Ayehu Asrie

    2016-06-01

    Full Text Available The study area is found North Western plateau in the North Gondar zone, Amhara regional state, Ethiopia. Its total surface coverage is 1887km2.The study area boundary was delineated from 90m Shutter Radar Terrain Mapping (SRTM digital elevation model (DEM using Global Mapper 8 software. Based on geologic information of the study area, unconfined subsurface flow condition was considered and simulated using MODFLOW 2000. The model calibration accounts the matching of the 58 observation point with simulated head with a permissible residual head of ±10m. 75% of the difference the observed and measured water level head in the study area is 5m. . The model was calibrated with mean error 0.506, absolute mean error 4.431m and standard deviation 6.083m. Based on the calibration process, the model is very sensitive in decreasing order change in recharge, hydraulic conductivity, and stream bed conductance. The simulated out flow of the model is 205.7Mm3/year which is nearly equal to simulated inflow with difference 2,887.45m3/yr. The base flow simulated discharge Megech River holds 35.8% of the out flow. The river contributed as recharge in to the aquifer that accounts to 15.3% of the inflow. Steady state withdrawal rates were increased by 15%, 35%, 55%, 75% and 100% to study the response of the system in this scenario. From the simulation results, one can observe that the development of a new groundwater sources would not pose appreciable impact in case of 15% and 35% withdrawal the head declines in this case is insignificant relative to the steady state withdrawal rate and the natural discharges were not altered highly. The simulation result indicated that the stream leakage decreased by 7.9% relative to the whole steady state value, but showed 14.9% decrease for Angereb, Keha, and Shinta river segments near the well field area. The water tables decline by 3.6m to18.8m in head observation in the well field area. The steady state simulated recharge was

  19. Submesoscale circulation in the Northern Gulf of Mexico: Surface processes and the impact of the freshwater river input

    CERN Document Server

    Luo, Hao; Cardona, Yuley; McWilliams, Jim C

    2015-01-01

    The processes and instabilities occurring at the ocean surface in the northern Gulf of Mexico are investigated with a regional model at submesoscale-permitting horizontal grid resolution (i.e., HR with dx = 1.6 km) over a three-year period, from January 2010 to December 2012. A mesoscale-resolving, lower resolution run (LR, with dx = 5 km) is also considered for comparison. The HR run is obtained through two-way nesting within the LR run. In HR quantities such local Rossby number, horizontal divergence, vertical velocity, and strain rate are amplified in winter, when the mixed layer is deepest, as found in other basins. In the model configuration considered this amplification occurs in surface waters over the continental slope and off-shore but not over the shelf. Submesoscale structures consist of a mixture of fronts and eddies generated by frontogenesis and mixed layer instabilities, with elevated conversion rates of available potential energy (APE) into eddy kinetic energy (EKE). In all quantities a second...

  20. Nitrate probability mapping in the northern aquifer alluvial system of the river Tagus (Portugal) using Disjunctive Kriging.

    Science.gov (United States)

    Mendes, Maria Paula; Ribeiro, Luís

    2010-02-01

    The Water Framework Directive and its daughter directives recognize the urgent need to adopt specific measures against the contamination of water by individual pollutants or a group of pollutants that present a significant risk to the quality of water. Probability maps showing that the nitrate concentrations exceed a legal threshold value in any location of the aquifer are used to assess risk of groundwater quality degradation from intensive agricultural activity in aquifers. In this paper we use Disjunctive Kriging to map the probability that the Nitrates Directive limit (91/676/EEC) is exceeded for the Nitrate Vulnerable Zone of the River Tagus alluvium aquifer. The Tagus alluvial aquifer system belongs to one of the most productive hydrogeological unit of continental Portugal and it is used to irrigate crops. Several groundwater monitoring campaigns were carried out from 2004 to 2006 according to the summer crops cycle. The study reveals more areas on the west bank with higher probabilities of contamination by nitrates (nitrate concentration values above 50mg/L) than on the east bank. The analysis of synthetic temporal probability map shows the areas where there is an increase of nitrates concentration during the summers.

  1. Coring the deep critical zone in the Jemez River Basin Critical Zone Observatory, Valles Caldera National Preserve, Northern New Mexico

    Science.gov (United States)

    Moravec, B. G.; White, A. M.; Paras, B.; Sanchez, A.; McGuffy, C.; Fairbanks, D.; McIntosh, J. C.; Pelletier, J. D.; Gallery, R. E.; Rasmussen, C.; Carr, B.; Holbrook, W. S.; Chorover, J.

    2016-12-01

    The Critical Zone (CZ) is the focus of current interdisciplinary Earth surface science research that aims to describe the interactions between geological and biological processes that influence ecosystem function, soil formation, nutrient and carbon cycling, hydrologic partitioning, biological activity and diversity, and mineral weathering. Prior research at the Catalina-Jemez (C-J) CZO has focused on the CZ near-surface, including remote sensing, and sampling/analysis of vegetation and soil microbiota, soils and saprolite, and surface water. However, the extent to which weathering, water/rock interaction, and solute mobility along flowpaths in the deep CZ respond to near surface CZ processes (i.e. water, energy, and mass fluxes) is not well understood. The goal of the present research is to understand depth-dependent trends in weathering dynamics from the mobile soil to unweathered bedrock in relation to landscape position (hillslope aspect and downgradient hollow). We used diamond core drilling techniques to excavate three boreholes to depths of 18.9, 41.8, and 46.3 meters in an instrumented forested sub-catchment of the C-J CZO in northern New Mexico. Here we present field methodology and preliminary data collected during the field campaign conducted during summer 2016. Element concentrations were measured during core extractions using portable X-ray fluorescence (XRF), which was subsequently validated against bench-scale XRF. Depth-dependent trends in both regolith depth and chemical depletion patterns show significant variation with landscape position. All three boreholes show complex weathering profiles with differences potentially due to textural controls on weathering, development of preferential flowpaths, and differing hydrologic base levels. Preliminary data indicate that chemical depletion patterns are not monotonic, but rather comprise large excursions that are being investigated for their relation to variation in local mineralogical composition and

  2. Survival and migration behavior of juvenile Coho Salmon in the Klamath River relative to discharge at Iron Gate Dam, Northern California, 2007

    Science.gov (United States)

    Beeman, John W.; Juhnke, Steve; Stutzer, Greg; Hetrick, Nicholas

    2008-01-01

    This report describes a study of survival and migration behavior of radio-tagged juvenile coho salmon (Oncorhynchus kisutch) in the Klamath River, northern California, in 2007. This was the third year of a multi-year study with the goal of determining the effects of discharge at Iron Gate Dam (IGD) on survival of juvenile coho salmon downstream. Survival and factors affecting survival were estimated in 2006 and 2007 after work in 2005 showed radio telemetry could be used effectively. The study has included collaborative efforts among U.S. Geological Survey (USGS), U.S. Fish and Wildlife Service (USFWS), the Karuk and Yurok Tribal Fisheries Departments, and the U.S. Bureau of Reclamation. The objectives of the study included: (1) estimating the survival of wild and hatchery juvenile coho salmon in the Klamath River downstream of Iron Gate Dam, determining the effects of discharge and other covariates on juvenile coho salmon survival (2) and migration (3), and (4) determining if fish from Iron Gate Hatchery (IGH) could be used as surrogates for the limited source of wild fish. We have been able to meet the first objective by estimating the survivals of hatchery and wild fish (when available) downstream of IGD. We have not yet met the second or third objectives, because we have been unable to separate effects of discharge from other environmental variables as they pertain to the survival or migration of juvenile coho salmon. This was foreseen when the study began, as it was known there would likely be no experimental discharges. A multi-year analysis will be conducted after the data for the third planned year are available. The fourth objective was initiated in 2006, but wild fish were not available in 2007. The next year wild fish may be available is in 2009, based on their 3-year cycle of abundance. River discharges during the 2007 study period (April 10 through July 28, 2007) were below average compared to the period of record beginning in 1962. Average daily

  3. Natural versus anthropogenic dispersion of metals to the environment in the Wulik River area, western Brooks Range, northern Alaska

    Science.gov (United States)

    Kelley, K.D.; Hudson, T.

    2007-01-01

    Zinc-lead-silver mineral deposits in the Wulik River region, Alaska, contain an enormous accumulation of Zn. In addition to the giant deposits at Red Dog, at least nine other deposits are known. Natural weathering of these deposits has dispersed metals over a wide region over a long period of time (c. 10 000 years) through transport by stream and groundwater, stream sediments, formation of soils, and perhaps wind-blown atmospheric deposition from weathering of naturally enriched Pb-Zn surface deposits. Anthropogenic input also contributes metals to the environment. Mining of the Red Dog deposit, which began in 1989, produces fine-grained galena and sphalerite concentrates that are transported from the mine site by truck to a storage port facility. Wind-blown dispersion of concentrate dust along the road and around the port facility has been a source of local metal-rich surficial materials. Geochemical and mineralogical characteristics provide a means of distinguishing the natural versus anthropogenic metal sources. Soils over deposits have patterns of increasing metal contents with depth and proximity to the metal-bearing source, whereas ore concentrate dust is localized at the surface. The acidity produced by weathering of the sulphide deposits creates an environment in which elements such as Se and Mo are stable whereas Ca is not. Consequently, high Mo (up to 29 ppm) and Se (up to 17 ppm) and low Ca (<0.4%) concentrations characterize surficial materials near natural deposits. Acidic conditions also yield high Pb-Zn ratios (up to 70) because sphalerite is preferentially dissolved and Zn is mobilized during chemical weathering. In natural materials, secondary jarosite and anglesite are developed, and minor galena is etched and rounded due to a history of chemical and mechanical weathering. In contrast, dust-bearing samples have Pb/Zn ratios that are 0.4 or less, Ca contents are higher (0.2 to 3.6%), and Mo (<10 ppm) and Se (not detected) concentrations are low

  4. In situ bioavailability of DDT and Hg in sediments of the Toce River (Lake Maggiore basin, Northern Italy): accumulation in benthic invertebrates and passive samplers.

    Science.gov (United States)

    Pisanello, Francesca; Marziali, Laura; Rosignoli, Federica; Poma, Giulia; Roscioli, Claudio; Pozzoni, Fiorenzo; Guzzella, Licia

    2016-06-01

    DDT and mercury (Hg) contamination in the Toce River (Northern Italy) was caused by a factory producing technical DDT and using a mercury-cell chlor-alkali plant. In this study, DDT and Hg contamination and bioavailability were assessed by using different approaches: (1) direct evaluation of sediment contamination, (2) assessment of bioaccumulation in native benthic invertebrates belonging to different taxonomic/functional groups, and (3) evaluation of the in situ bioavailability of DDT and Hg using passive samplers. Sampling sites were selected upstream and downstream the industrial plant along the river axis. Benthic invertebrates (Gammaridae, Heptageniidae, and Diptera) and sediments were collected in three seasons and analyzed for DDT and Hg content and the results were used to calculate the biota sediment accumulation factor (BSAF). Polyethylene passive samplers (PEs) for DDT and diffusive gradients in thin films (DGTs) for Hg were deployed in sediments to estimate the concentration of the toxicants in pore water. Analysis for (DDx) were performed using GC-MS. Accuracy was within ±30 % of the certified values and precision was >20 % relative standard deviation (RSD). Total mercury concentrations were determined using an automated Hg mercury analyzer. Precision was >5 % and accuracy was within ±10 % of certified values. The results of all the approaches (analysis of sediment, biota, and passive samplers) showed an increasing contamination from upstream to downstream sites. BSAF values revealed the bioavailability of both contaminants in the study sites, with values up to 49 for DDx and up to 3.1 for Hg. No correlation was found between values in sediments and the organisms. Concentrations calculated using passive samplers were correlated with values in benthic invertebrates, while no correlation was found with concentrations in sediments. Thus, direct analysis of toxicant in sediments does not provide a measurement of bioavailability. On the contrary

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

    Science.gov (United States)

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

    2011-01-01

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

  6. Development of a high-resolution binational vegetation map of the Santa Cruz River riparian corridor and surrounding watershed, southern Arizona and northern Sonora, Mexico

    Science.gov (United States)

    Wallace, Cynthia S.A.; Villarreal, Miguel L.; Norman, Laura M.

    2011-01-01

    This report summarizes the development of a binational vegetation map developed for the Santa Cruz Watershed, which straddles the southern border of Arizona and the northern border of Sonora, Mexico. The map was created as an environmental input to the Santa Cruz Watershed Ecosystem Portfolio Model (SCWEPM) that is being created by the U.S. Geological Survey for the watershed. The SCWEPM is a map-based multicriteria evaluation tool that allows stakeholders to explore tradeoffs between valued ecosystem services at multiple scales within a participatory decision-making process. Maps related to vegetation type and are needed for use in modeling wildlife habitat and other ecosystem services. Although detailed vegetation maps existed for the U.S. side of the border, there was a lack of consistent data for the Santa Cruz Watershed in Mexico. We produced a binational vegetation classification of the Santa Cruz River riparian habitat and watershed vegetation based on NatureServe Terrestrial Ecological Systems (TES) units using Classification And Regression Tree (CART) modeling. Environmental layers used as predictor data were derived from a seasonal set of Landsat Thematic Mapper (TM) images (spring, summer, and fall) and from a 30-meter digital-elevation-model (DEM) grid. Because both sources of environmental data are seamless across the international border, they are particularly suited to this binational modeling effort. Training data were compiled from existing field data for the riparian corridor and data collected by the NM-GAP (New Mexico Gap Analysis Project) team for the original Southwest Regional Gap Analysis Project (SWReGAP) modeling effort. Additional training data were collected from core areas of the SWReGAP classification itself, allowing the extrapolation of the SWReGAP mapping into the Mexican portion of the watershed without collecting additional training data.

  7. Reactivation of a collisional suture by Miocene transpressional domes associated with the Red River and Song Chay detachment faults, northern Vietnam

    Science.gov (United States)

    Osozawa, Soichi; Van Vuong, Nguyen; Van Tich, Vu; Wakabayashi, John

    2015-06-01

    Elongate Miocene gneissose and granitic domes in northern Vietnam formed in a dextral-transpressional ductile shear regime, possibly associated with large-scale restraining step-overs along dextral faults. Initial anticlinal D1 doming involved folding of both basement and hanging wall rocks with D1 secondary folds that verge toward the anticlinal axes. Such folds reflect dome-scale flexural slip folding. With continued shortening, D2 detachment faults developed on the flanks of the anticlines along the hanging wall-basement interface, so that the basement was extruded vertically into the overlying hanging wall rocks. The detachment faults were associated with D2 drag folds that verge away from the anticlinal axes. The hanging wall assemblage lacks a well-ordered stratigraphy, displaying primarily block-in-matrix fabric. We identified bedded cherts, associated with umbers and alkalic basaltic intrusions within these hanging wall rocks, a first report of such rocks from Vietnam. The association of cherts, umbers, and basaltic intrusions and extrusions with block-in-matrix units with clastic rocks strongly suggest that the hanging wall rocks comprise part of a subduction complex. Because the base of a subduction complex is a former subduction megathrust horizon, the hanging wall-basement interface represents a reactivated collisional suture. Such a suture was probably associated with the Indosinian orogeny, and the basement should be the Indochina continental block. This structure may have influenced the position of Miocene dextral faulting in addition to controlling the position of the dome detachments. The well-known Red River fault marks the boundary of one of the domes, but in this region it appears to be a detachment (normal) fault rather than a dextral strike-slip fault. However, the association with the dome evolution with large-scale restraining step-overs suggests that dextral faulting associated with dome development may lie further away from the dome axes

  8. Local social capital and the acceptance of Protected Area policies: an empirical study of two Ramsar river delta ecosystems in northern Greece.

    Science.gov (United States)

    Jones, N; Clark, J R A; Panteli, M; Proikaki, M; Dimitrakopoulos, P G

    2012-04-15

    Managing Protected Areas (PAs) is a challenging task, and globally many instruments have been utilised for this purpose. Existing research demonstrates that the effectiveness of these instruments is highly dependent on their social acceptability among local communities resident within PAs. Consequently, investigating local attitudes and perceptions of Protected Area (PA) policies has been emphasised in recent studies. Drawing on empirical work conducted in two National Parks including river delta ecosystems designated as Ramsar wetlands in northern Greece, this paper examines local residents' perceptions of three hypothesized policy options (regulatory, market-based and participatory) for Park management. The influence of social capital elements (social trust, institutional trust and social networks) on residents' perceptions is explored. The findings reveal a high degree of importance attached by resident communities to Park designation in both PAs, though residents' perceptions of the proposed management options varied. The regulatory option was regarded as the least restrictive, while the most restrictive was perceived to be the market-based option. However, greater benefits were identified by residents from the market-based option, while the fewest benefits were considered to arise from the proposed regulatory option. Furthermore, local residents' perceptions were significantly shaped by the proposed management and decision-making structure offered under each policy option. The influence of different social capital elements on residents' perceptions also varied in the study sample, with social trust and institutional trust positively correlated with the benefits that were perceived to arise from the different policy options. Moreover, when social capital was measured as an aggregate indicator at the level of the individual, it was positively correlated with perceived environmental benefits.

  9. The As-contaminated Elqui river basin: a long lasting perspective (1975-1995) covering the initiation and development of Au-Cu-As mining in the high Andes of northern Chile.

    Science.gov (United States)

    Oyarzun, R; Guevara, S; Oyarzún, J; Lillo, J; Maturana, H; Higueras, P

    2006-10-01

    The Elqui watershed (northern Chile) constitutes a highly contaminated river system, with arsenic exceeding by up to three orders of magnitude the average for river waters. There are three main reasons that explain this contamination: (1) the regional geology and hydrothermal (mineralizing) processes that developed in this realm during Miocene time; (2) the later unroofing-erosion-oxidation-leaching of As-Cu rich sulfide ores, a process that have been taking place for at least 10,000 years; and last but not least (3) mining activities at the high-altitude (>4000 m above sea level) Au-Cu-As El Indio mine, from the late 1970s onwards. The El Indio mineral deposit hosted large veins of massive sulfides, including the important presence of enargite (Cu(3)AsS(4)). The continuous natural erosion of these veins and their host rocks (also rich in As and Cu) during Holocene time, led to important and widespread metal dispersion along the river system. During the studied pre mining period (1975-1977), the high altitude river Toro waters already showed very large As concentrations (0.36-0.52 mg l(-1)). The initiation of full scale mining at El Indio (1980 onwards) led to an increase of these values, reaching a concentration of 1.51 mg l(-1) As in 1995. During the same year other rivers of the watershed reached peak As concentrations of 0.33 (Turbio) and 0.11 mg l(-1) (Elqui). These figures largely exceed the USEPA regulations for drinking water (0.01 mg l(-1) As), and about 10% of the total As data from the river Elqui (and 70% from the river Turbio) are above the maximum level allowed by the Chilean law for irrigation water (0.1 mg l(-1) As).

  10. Evaluation of groundwater-surface water interaction through groundwater modelling: simulation of the effects of removal of a dam along a river at a contaminated site in Northern France

    Directory of Open Access Journals (Sweden)

    Michele Remonti

    2013-06-01

    Full Text Available A numerical groundwater flow model has been developed for an industrial site bounded by a river in in Basse Normandie, Northern France. The scope of the work was the optimisation of the existing groundwater pump and treat system and the prediction of possible effects on groundwater circulation after the future removal of a dam located along the river. The model has been implemented with the finite difference code MODFLOW 2005 and represents an area with an extension of approximately 800 x 500 m. It has been calibrated using static conditions groundwater head data (wells deactivated and verified with 1 abstracting conditions (wells abstracting head data, 2 simulating pumping tests with transient simulations and 3 comparing measured average river baseflow with modelled river drainage. The model indicates that the hydraulic barrier in the present abstraction scenario has some problematic areas and needs some improvements, as confirmed by the hydrochemical data of the river water. A first predictive scenario has been developed to optimise the barrier, indicating that a flow rate of 0.5 m3/h each at three new barrier wells, in addition to the present abstraction scenario, should ensure the hydraulic containment of the site. A second predictive scenario simulates the optimised groundwater abstractions without the presence of the dam along the neighbouring river. In these conditions, the river will increase the drainage effect on the aquifer, requiring a further increase in the rate of abstraction from the existing and new wells to ensure the hydraulic containment. With this paper we would like to present an example of what we think is a correct professional approach, with the design of the simplest model as possible depending on the hydrogeological conceptual model complexity, the abundance of data and the model objectives, and where multiple confirmations of the correctness of groundwater model results have been searched for.

  11. Seasonal Changes in Mayfly Communities and Abundance in Relation to Water Physicochemistry in Two Rivers at Different Elevations in Northern Peninsular Malaysia

    Institute of Scientific and Technical Information of China (English)

    Suhaila Abdul Hamid; Mohd Ravi Che Salmah; Hamady Dieng; Abu Hassan Ahmad; Tomomitsu Satho; Fumio Miake

    2011-01-01

    A field study was performed at rivers in Gunung Jerai forest reserve (Kedah,Malaysia) to assess seasonal changes in mayfly community structure and abundance in relation to altitude and water physicochemistry.Rivers at lower (Batu Hampar River) and higher (Teroi River) elevations were visited through dry and wet seasons in September 2007 to August 2008.Monthly visits were made to 20 sites on each river,and water and aquatic insects were sampled using D-pond aquatic nets.Water was warmer,more acid,and more turbid in Teroi River during wet season.Ammonia was the only nutrient exhibiting significant seasonal variations (greater during wet season).Chemical oxygen demand content was higher in Teroi River where biochemical oxygen demand content was low during wet season.Species richness was higher in Batu Hampar River,but displayed seasonal variations only in Teroi River.Among the eight families encountered,Baetidae was the commonest.Baetid abundance was usually high during wet season,and those belonging to the dominant genus (Baetis) were more abundant in Teroi River.Heptageniidae was the second commonest family; its predominant genus,Thalerospyrus was more abundant in Teroi River during dry season.Caenidae,Leptophlebiidae and Oligoneuriidae were only found in Batu Hampar River where their abundances peaked during dry season,i.e.,Habrophlebiodes sp.and Isonychia sp.Ephemerellidae and Teloganodidae occurred only in Teroi River,with the first found only during dry season.Mayflies were recorded under very distinct physicochemical conditions,illustrating their potential usefulness for assessing water quality.Caenids,leptophlebids,oligoneurids ephemerellids and teloganodids seem to be particularly sensitive to temperature,acidity,turbidity,chemical oxygen demand and biochemical oxygen demand,parameters that varied with river altitude.

  12. 2.8-Ma ash-flow caldera at Chegem River in the northern Caucasus Mountains (Russia), contemporaneous granites, and associated ore deposits

    Science.gov (United States)

    Lipman, P.W.; Bogatikov, O.A.; Tsvetkov, A.A.; Gazis, C.; Gurbanov, A.G.; Hon, K.; Koronovsky, N.V.; Kovalenko, V.I.; Marchev, P.

    1993-01-01

    Diverse latest Pliocene volcanic and plutonic rocks in the north-central Caucasus Mountains of southern Russia are newly interpreted as components of a large caldera system that erupted a compositionally zoned rhyolite-dacite ash-flow sheet at 2.83 ?? 0.02 Ma (sanidine and biotite 40Ar/39Ar). Despite its location within a cratonic collision zone, the Chegem system is structurally and petrologically similar to typical calderas of continental-margin volcanic arcs. Erosional remnants of the outflow Chegem Tuff sheet extend at least 50 km north from the source caldera in the upper Chegem River. These outflow remnants were previously interpreted by others as erupted from several local vents, but petrologic similarities indicate a common origin and correlation with thick intracaldera Chegem Tuff. The 11 ?? 15 km caldera and associated intrusions are superbly exposed over a vertical range of 2,300 m in deep canyons above treeline (elev. to 3,800 m). Densely welded intracaldera Chegem Tuff, previously described by others as a rhyolite lava plateau, forms a single cooling unit, is > 2 km thick, and contains large slide blocks from the caldera walls. Caldera subsidence was accommodated along several concentric ring fractures. No prevolcanic floor is exposed within the central core of the caldera. The caldera-filling tuff is overlain by andesitic lavas and cut by a 2.84 ?? 0.03-Ma porphyritic granodiorite intrusion that has a cooling age analytically indistinguishable from that of the tuffs. The Eldjurta Granite, a pluton exposed low in the next large canyon (Baksan River) 10 km to the northwest of the caldera, yields variable K-feldspar and biotite ages (2.8 to 1.0 Ma) through a 5-km vertical range in surface and drill-hole samples. These variable dates appear to record a prolonged complex cooling history within upper parts of another caldera-related pluton. Major W-Mo ore deposits at the Tirniauz mine are hosted in skarns and hornfels along the roof of the Eldjurta Granite

  13. Uso das terras da parte norte da bacia do Rio Descoberto, Distrito Federal, Brasil Land use in the northern region of the descoberto river watershed, Distrito Federal, Brazil

    Directory of Open Access Journals (Sweden)

    Aurélio Alves Amaral Chaves

    2010-01-01

    Full Text Available Este trabalho teve como objetivo avaliar o uso das terras da porção norte da Área de Proteção Ambiental do Rio Descoberto, englobando as microbacias dos Córregos Barrocão, Bucanhão e Capão da Onça, com auxílio de técnicas de geoprocessamento. Elaborou-se o mapa de uso das terras a partir de processamentos da imagem de satélite SPOT 4, obtida em 2003, por meio do software ENVI 3.6. Posteriormente, verificou-se a adequabilidade do uso das terras, com base em técnicas de cruzamento e operações de tabulação cruzada entre os mapas de uso e aptidão agrícola das terras, utilizando-se o software ArcView 8.3, permitindo a geração do mapa de adequabilidade de uso das terras. Pelos resultados, constatou-se que a maior parte da área estudada a utilização das terras está abaixo do seu potencial agrícola, caracterizando sustentabilidade da utilização dos recursos naturais, particularmente solos.This work had the objective to evaluate the land use in the northern region of the Environmental Protection Area of Descoberto River, which encompasses the watersheds of the streams Barrocão, Bucanhão and Capão da Onça, accomplished with the support of geoprocessing techniques. A land use map of the area was produced through analysis and treatment of SPOT 4 satellite images, obtained in 2003, using the software ENVI 3.6. Then, the adequation of land use was checked using cross-tabulation between the maps of present and potential use for agriculture, with the software ArcView 8.3, allowing development of a map of land use suitability. The results showed that most of the area has been used under its agricultural potential, characterizing sustainability in the use of the natural resources, particularly of the soils.

  14. Freshwater reservoir effect variability in Northern Germany

    DEFF Research Database (Denmark)

    Philippsen, Bente; Heinemeier, Jan

    2012-01-01

    Kayhude at the river Alster and Schlamersdorf at the river Trave, both in Schleswig-Holstein, Northern Germany. Measurements on modern materials from these rivers may not give a single reservoir age correction that can be applied to archaeological samples, but they will show the order of magnitude...

  15. Flow characteristics and salinity patterns of tidal rivers within the northern Ten Thousand Islands, southwest Florida, water years 2007–14

    Science.gov (United States)

    Booth, Amanda C.; Soderqvist, Lars E.

    2016-12-12

    Freshwater flow to the Ten Thousand Islands estuary has been altered by the construction of the Tamiami Trail and the Southern Golden Gate Estates. The Picayune Strand Restoration Project, which is associated with the Comprehensive Everglades Restoration Plan, has been implemented to improve freshwater delivery to the Ten Thousand Islands estuary by removing hundreds of miles of roads, emplacing hundreds of canal plugs, removing exotic vegetation, and constructing three pump stations. Quantifying the tributary flows and salinity patterns prior to, during, and after the restoration is essential to assessing the effectiveness of upstream restoration efforts.Tributary flow and salinity patterns during preliminary restoration efforts and prior to the installation of pump stations were analyzed to provide baseline data and preliminary analysis of changes due to restoration efforts. The study assessed streamflow and salinity data for water years1 2007–2014 for the Faka Union River (canal flow included), East River, Little Wood River, Pumpkin River, and Blackwater River. Salinity data from the Palm River and Faka Union Boundary water-quality stations were also assessed.Faka Union River was the dominant contributor of freshwater during water years 2007–14 to the Ten Thousand Islands estuary, followed by Little Wood and East Rivers. Pumpkin River and Blackwater River were the least substantial contributors of freshwater flow. The lowest annual flow volumes, the highest annual mean salinities, and the highest percentage of salinity values greater than 35 parts per thousand (ppt) occurred in water year 2011 at all sites with available data, corresponding with the lowest annual rainfall during the study. The highest annual flow volumes and the lowest percentage of salinities greater than 35 ppt occurred in water year 2013 for all sites with available data, corresponding with the highest rainfall during the study.In water year 2014, the percentage of monitored annual flow

  16. Biogeochemical factors affecting the distribution, speciation, and transport of Hg species in the Deûle and Lys Rivers (Northern France).

    Science.gov (United States)

    Daye, Mirna; Kadlecova, Milada; Ouddane, Baghdad

    2015-02-01

    The Deûle River is a highly polluted River by heavy metals caused by the historical discharges of ore minerals from the former ore smelter "Metaleurop." The potential mercury (Hg) pollution in the Deûle River implicates the importance of Hg distribution study in the river. As well as to configure the different biogeochemical factors that control the distribution and the potential transport of Hg to distant places. Four different sites were studied as follows: D-A (Deûle River, a site located upstream the river), D-B (Deûle River, a site located near a Zn, Pb, Cu, and Ni smelter that closed in 2003), L-C (Lys River, a site located upstream the confluence of the Deûle River with Lys River), and L-D (downstream the rivers confluence). Different Hg analyses were performed including total mercury in sediment (HgTS), methylmercury (MeHg) in sediment, total mercury in pore water (HgTPW), total mercury in surface water (HgTD), and total suspended particulate Hg in water (HgTP). HgTS decreases downstream from the Deûle River sites with a mean value of 11 ± 0.34 mg/kg to Lys River site (L-D) with a mean value of 0.53 ± 0.02 mg/kg at the confluence. The unaffected side of the Lys River, localized before the confluence (L-C), is characterized by low HgTS of an average value of 0.042 ± 0.003 mg/kg and high % MeHg reaching 4.2 %. Whereas, the highly contaminated Deûle sites are designated by low % MeHg with an average value of 0.053 %. Low pristine environments like that found in L-C site with more favorable biogeochemical conditions of lower concentrations of HgTS, sulfides, and Corg host more active biotic methylation than that of the highly polluted Deûle sites with high concentrations of HgTS and sulfides concentrations. Methylation in D-B (the closet site to Metaleurop smelter) is an old and recent methylation activity that has contributed to MeHg accumulation in the sediments as opposed to the exclusive recent events of methylation in Lys sites. Me

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

    Data.gov (United States)

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

  18. Distinct Variations in Seismic Velocity Structure of the Crust and Upper Mantle across the Ailao Shan-Red River Shear Zone in Northern Vietnam

    Science.gov (United States)

    Hung, S.; Pan, Y.; Huang, B.; Huang, W.; Le, T.; Dinh, V.

    2011-12-01

    The tectonic evolution of the Aliao Shan-Red River shear zone (RRSZ) that runs from southeast Tibet through North Vietnam to the South China Sea and marks the boundary between the Indochina and South China blocks has been considered closely linked with the northward indention of the strong Indian plate into the Eurasian continent and the consequent uplift of the Tibetan Plateau. A variety of models have been proposed to explain the postcollisional deformation and magmatism of SE Asia and movement along the RRSZ. Since December 2005, Institute of Earth Science, Academia Sinica of Taiwan has deployed a regional broadband array with station spacing of ~50 km in Northern Vietnam for earthquake and seismic structure studies. We collect data from earthquakes with magnitude≥5.5 and epicentral distances of 30-90o between December, 2005 and June, 2008. Using this new dataset, we report 3-D variations of P- and S-wave speeds (δlnVP and δlnVS) and Poisson's ratios via δln(VP/VS) in the crust and upper mantle across the shear zone, obtained with tomographic inversion of P and S relative travel time residuals measured by inter-station cross-correlation of waveforms at both high- and low-frequencies. We employ physically realistic 3-D sensitivity kernels for frequency-dependent traveltime data and data-adaptive, multi-scale parameterization in the inversion. The resulting models reveal noticeable differences across the RRSZ, where the anomalies of distinctly low VS and VP/VS are widely-dispersed in the lower crust and uppermost mantle down to the depth of 100 km to the southwest of the RRSZ. This may indicate that ductile crustal mass has flowed out of Tibet into Indochina accompanying extrusion of relatively hot lithospheric mantle along the RRSZ related to Late Cenozoic volcanism in the region. Though less distinct in the S velocity model, an elongated fast anomaly about 60 km wide that strikes parallel to the RRSZ and subvertically extends to the depth of 60 km clearly

  19. Russian River Ice Thickness and Duration

    Data.gov (United States)

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

  20. No evidence of exposure to environmental estrogens in two feral fish species sampled from the Yarra River, Australia: A comparison with Northern Hemisphere studies

    OpenAIRE

    Hassell, K; Pettigrove, V; BERESFORD, N.; Jobling, S; Kumar, A.

    2016-01-01

    Environmental estrogens originate from a variety of sources including sewage treatment plant (STP) effluents and adverse physiological effects (endocrine disruption) have been observed in several fish species sampled downstream of STP discharges. In this study we examined common carp (Cyprinus carpio) and roach (Rutilis rutilis) for signs of exposure to environmental estrogens in the iconic Yarra River, Melbourne, Australia. The Yarra River flows through the city of Melbourne and more than 2 ...

  1. Offshore baseline for the northern Alaska coastal region generated to calculate shoreline change rates along sheltered coastlines between the Okpilak-Hulahula River Delta and the Colville River Delta for the time period 1947 to 2007

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Arctic Coastal Plain of northern Alaska is an area of strategic economic importance to the United States, is home to remote Native American communities, and...

  2. Offshore baseline for the northern Alaska coastal region generated to calculate shoreline change rates along exposed coastlines between the Okpilak-Hulahula River Delta and the Colville River Deltas for the time period 1947 to 2007

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Arctic Coastal Plain of northern Alaska is an area of strategic economic importance to the United States, is home to remote Native American communities, and...

  3. Offshore baseline for the northern Alaska coastal region generated to calculate shoreline change rates along sheltered coastlines between the Okpilak-Hulahula River Delta and the Colville River Delta for the time period 1947 to 2007

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Arctic Coastal Plain of northern Alaska is an area of strategic economic importance to the United States, is home to remote Native American communities, and...

  4. Offshore baseline for the northern Alaska coastal region generated to calculate shoreline change rates along exposed coastlines between the Okpilak-Hulahula River Delta and the Colville River Deltas for the time period 1947 to 2007

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Arctic Coastal Plain of northern Alaska is an area of strategic economic importance to the United States, is home to remote Native American communities, and...

  5. Responses of streamflow to climate change in the northern slope of Tianshan Mountains in Xinjiang: A case study of the Toutun River basin

    Institute of Scientific and Technical Information of China (English)

    LI WeiHong; CHEN YaNing; HAO XingMing; HUANG Xiang; CHEN YaPeng

    2007-01-01

    A case study on the responses of streamflow to climate change in the Toutun River basin was carried out based on data analysis of streamflow, precipitation, and temperatures during the past 50 years.Temporal series of the streamflow change in the Toutun River basin was analyzed and tested using the Mann-Kendall nonparametric test. Results revealed that the annual runoff of the Toutun River had been in a monotonic decreasing trend for the past 50 years. Compared with the 1950s and 1960s, the annual runoff in the 1990s decreased by 4.0×105 m3 and 7.2×105 m3. The precipitation did not show monotonic trend during the past 50 years, but the annual temperature increased by 1.12℃ since the 1950s. Further data analysis indicated that the monthly runoff of the Toutun River decreased significantly from August to October, with precipitation displaying the similar pattern of seasonal change. Analysis suggests that the reduction of streamflow in the Toutun River basin is possibly caused by the seasonal change of precipitation, especially the precipitation reduction in summer, and temperature increases.

  6. Spatial-temporal coastline evolution of the old Yellow River delta,northern Jiangsu Province%苏北废黄河三角洲海岸线历史时空演化研究

    Institute of Scientific and Technical Information of China (English)

    徐伟; 彭修强; 贾培宏; 王敏京

    2014-01-01

    The old Yellow River delta is associated with muddy coastlines and one of the most severe erosion areas in China.Based on the regional topographic maps,charts,historical atlas,satellite remote sensing images and historical literature,a geodatabase of coastlines was established by GIS/RS technology and statistic principles.Quantitative in-formation of coastline changes was synthesized by using the superposition of different periods of coastline data.The coastlines in consideration have experienced a stable stage from the Chunqiu Period to Northern Song Dynasty and a rapid progradation after Northern Song Dynasty;since then,the coastlines were subj ected to another retreating event and become presently gradually stabilized.This process was under the control of the Yellow River changing its course.Since 1989,the main eroding area is located between the Zhongshan River mouth to the Biandan River mouth.Retrogradation rate varied in different parts,which is lower in the north of the old Yellow River mouth than in the south.North of the Zhongshang River mouth and south of the Kuatao River mouth are siltation dominated. These differences were affected by coastal topography and human activities.%苏北废黄河三角洲属淤泥质海岸类型,是我国海岸侵蚀严重的地区之一.本文根据地形图、海图、历史地图、遥感影像及历史文献等资料,应用 GIS/RS技术及数理统计原理,对废黄河三角洲海岸线空间演化特征进行定量分析,以研究历史时期以来苏北废黄河三角洲岸线的整体演变特征.自春秋以来,废黄河三角洲海岸线经历了春秋至北宋的相对稳定,北宋后快速向海推进,再向陆侵蚀内移并逐渐趋于稳定的过程,这一过程主要受黄河南徙与北归的控制.1989年以来,中山河口至扁担河口岸段是主要侵蚀区,不同部位蚀退速率有差异,北部蚀退速率小于南部,中山河口以北、夸套河口以南则以淤积为主

  7. Bioaccumulation of Heavy Metals and Microelements in Silver Bream (Brama brama L.), Northern Pike (Esox lucius L.), Sterlet (Acipenser ruthenus L.), and Common Carp (Cyprinus carpio L.) From Tisza River, Serbia.

    Science.gov (United States)

    Štrbac, Snežana; Kašanin-Grubin, Milica; Jovančićević, Branimir; Simonović, Predrag

    2015-01-01

    The aim of this study was to determine the concentrations of Al, As, B, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, Sr, and Zn in liver, gills, gonads, and brain of four ecologically different fish species in Serbia: piscivorous northern pike, benthivorous sterlet and silver bream, and omnivorous common carp. Fish were caught at four sites along the stretch of the River Tisza in the Pannonian part of Serbia during October 2010. Results revealed that heavy metals and microelements with the highest values in fish samples were Fe, Al, and Zn. The highest concentration of heavy metals and microelements was recorded in omnivorous common carp, and organs that most intensively accumulated the greatest number of metals were liver and gills, whereas the locality did not exert a marked impact on level of bioaccumulation.

  8. Transplant of Oncorhynchus in Dayang River of the Yellow Sea northern shore%黄海北岸大洋河大麻哈鱼类的移植

    Institute of Scientific and Technical Information of China (English)

    王会芳; 李征远; 田军; 孙莉; 谭学群; 堀淳

    2004-01-01

    According to the salmon's(Oncorhynchus) biological character of return to its hatching river, adopting the method of transplant and releasing, 9839000 eyed eggs of the salmon were introduced (Oncorhynchu, keta, O.gorbuscha, O. kisutch, O. masou) from Japan, total 8409000 juvenile fish was hatched and cultivated for 11 years running from 1985 to 1996. total 127 returning and mature salmons were collected from 1987 to 1995. It proved that the salmon could exist in the Yellow Sea area and return to its releasing river.

  9. Effects of Iron Gate Dam discharge and other factors on the survival and migration of juvenile coho salmon in the lower Klamath River, northern California, 2006-09

    Science.gov (United States)

    Beeman, John; Juhnke, Steven; Stutzer, Greg; Wright, Katrina

    2012-01-01

    Current management of the Klamath River includes prescribed minimum discharges intended partly to increase survival of juvenile coho salmon during their seaward migration in the spring. To determine if fish survival was related to river discharge, we estimated apparent survival and migration rates of yearling coho salmon in the Klamath River downstream of Iron Gate Dam. The primary goals were to determine if discharge at Iron Gate Dam affected coho salmon survival and if results from hatchery fish could be used as a surrogate for the limited supply of wild fish. Fish from hatchery and wild origins that had been surgically implanted with radio transmitters were released into the Klamath River slightly downstream of Iron Gate Dam at river kilometer 309. Tagged fish were used to estimate apparent survival between, and passage rates at, a series of detection sites as far downstream as river kilometer 33. Conclusions were based primarily on data from hatchery fish, because wild fish were only available in 2 of the 4 years of study. Based on an information-theoretic approach, apparent survival of hatchery and wild fish was similar, despite differences in passage rates and timing, and was lowest in the 54 kilometer (km) reach between release and the Scott River. Models representing the hypothesis that a short-term tagging- or handling-related mortality occurred following release were moderately supported by data from wild fish and weakly supported by data from hatchery fish. Estimates of apparent survival of hatchery fish through the 276 km study area ranged from 0.412 (standard error [SE] 0.048) to 0.648 (SE 0.070), depending on the year, and represented an average of 0.790 per 100 km traveled. Estimates of apparent survival of wild fish through the study area were 0.645 (SE 0.058) in 2006 and 0.630 (SE 0.059) in 2009 and were nearly identical to the results from hatchery fish released on the same dates. The data and models examined supported positive effects of water

  10. Molecular detection of Campylobacter spp. and fecal indicator bacteria during the northern migration of Sandhill Cranes (Grus canadensis) at the Central Platte River

    Science.gov (United States)

    The annual Sandhill crane (Grus canadensis) migration through Nebraska is thought to be a major source of fecal pollution to the Platte River, but of unknown human health risk. To better understand potential risks, the presence of Campylobacter species and fecal bacteria were exa...

  11. Molecular detection of Campylobacter spp. and fecal indicator bacteria during the northern migration of Sandhill Cranes (Grus canadensis) at the Central Platte River

    Science.gov (United States)

    The annual Sandhill crane (Grus canadensis) migration through Nebraska is thought to be a major source of fecal pollution to the Platte River, but of unknown human health risk. To better understand potential risks, the presence of Campylobacter species and fecal bacteria were exa...

  12. Mercury and selenium in European catfish (Silurus glanis) from Northern Italian Rivers: can molar ratio be a predictive factor for mercury toxicity in a top predator?

    Science.gov (United States)

    Squadrone, S; Benedetto, A; Brizio, P; Prearo, M; Abete, M C

    2015-01-01

    The study of mercury and selenium bioaccumulation in fish is crucially important for evaluating the extent of contamination in freshwater environments, and the possible health risk posed for humans when the antagonistic interactions of these two elements are considered. Several factors affect the risk of mercury intake from fish consumption, including mercury levels, human consumption patterns, and sensitive populations (e.g., pregnant women, foetuses, young children and unknown genetic factors). The protective effects of selenium on mercury toxicity have been extensively publicised in recent years, particularly targeting fish consumers. In this study, mercury (Hg) and selenium (Se) concentrations were determined in the muscle of European catfish (Silurus glanis) collected from North Italian Rivers. Differences in mercury and selenium levels, as a function of size, gender and location were investigated. Hg was strongly related to length, gender and location, while Se levels are not dependent on fish size or location. The mean Se/Hg molar ratio was strongly affected by location, and significantly related to length and age. Selenium was in molar excess of mercury in all sites, with a rank order of mean Se/Hg molar ratio of the Parma River (2.55)>Po River (1.71)>Tanaro River (1.66)>Bormida River (1.36). However, in 37% of analyzed samples, Hg exceeded the maximum level set by 1881/2006/EC and 629/2008/EC in fish muscle. The molar ratio of Se/Hg was 0.5mg/kg), and therefore the mean molar ratio cannot be considered as a safety criterion in top predator fish.

  13. Assessing the effect of sea-level change and human activities on a major delta on the Pacific coast of northern South America: The Patía River

    Science.gov (United States)

    Restrepo A, Juan D.

    2012-05-01

    This paper presents the main physical and human-induced stresses that have shaped the recent evolution of the Patía River delta, the largest and best-developed delta on the western margin of South America. During the Holocene, the Patía Delta moved southward and the northern part became an estuarine system characterized by large extensions of mangrove ecosystems. However, a major human-induced water diversion, starting in 1972, diverted the Patía flow to the Sanguianga River, and shifted the active delta plain back to its former Holocene location. This discharge diversion has led to sediment starvation of the southern delta lobe and changed the northern estuarine system into an active delta plain. In addition, coastal areas of the Patía delta subsided as a result of a devastating tsunami in 1979. Morphological changes along the delta coast are evidenced by: (1) coastal retreat along the whole delta front during the period 1986-2001; (2) coastal retreat along the abandoned delta lobe for the period 2001-2008; 56% of the southern delta shoreline is retreating and only 4% of the coast shows signs of accretion; (3) progradation of the northern delta region during the period 2001-2008; the discharge diversion of the Patía River to the Sanquianga has apparently balanced the observed trends in coastal erosion and sea-level rise (5.1 mm yr- 1 for the period 1984-2006, after the 1979 tsunami); (4) formation of transgressive barrier islands with exposed peat soils in the surf zone; and (5) abandonment of former active distributaries in the southern delta plain with associated inlet closure. In the northern delta lobe, major geomorphic changes include: (1) distributary channel accretion by morphological processes such as sedimentation (also in crevasses), overbank flow, increasing width of levees, inter-distributary channel fill, and colonization of pioneer mangrove; (2) freshening conditions in the Sanguianga distributary channel, a hydrologic change that has shifted

  14. Use of acoustic backscatter to estimate continuous suspended sediment and phosphorus concentrations in the Barton River, northern Vermont, 2010-2013

    Science.gov (United States)

    Medalie, Laura; Chalmers, Ann T.; Kiah, Richard G.; Copans, Benjamin

    2014-01-01

    The U.S. Geological Survey, in cooperation with the Vermont Department of Environmental Conservation, investigated the use of acoustic backscatter to estimate concentrations of suspended sediment and total phosphorus at the Barton River near Coventry, Vermont. The hypothesis was that acoustic backscatter—the reflection of sound waves off objects back to the source from which they came—measured by an acoustic Doppler profiler (ADP) and recorded as ancillary data for the calculation of discharge, also could be used to generate a continuous concentration record of suspended sediment and phosphorus at the streamgage, thereby deriving added value from the instrument. Suspended-sediment and phosphorus concentrations are of particular interest in Vermont, where impairment of surface waters by suspended sediments and phosphorus is a major concern. Regression models for estimating suspended-sediment concentrations (SSCs) and total phosphorus concentrations evaluated several independent variables: measured backscatter (MB), water-corrected backscatter (WCB), sediment-corrected backscatter (SCB), discharge, fluid-absorption coefficient, sediment-driven acoustic attenuation coefficient, and discharge hysteresis. The best regression equations for estimating SSC used backscatter as the predictor, reflecting the direct relation between acoustic backscatter and SSC. Backscatter was a better predictor of SSC than discharge in part because hysteresis between SSC and backscatter was less than for SSC and discharge. All three backscatter variables—MB, WCB, and SCB—performed equally as predictors of SSC and phosphorus concentrations at the Barton River site. The similar abilities to predict SSC among backscatter terms may partially be attributed to the low values and narrow range of the sediment-driven acoustic attenuation in the Barton River. The regression based on SCB was selected for estimating SSC because it removes potential bias caused by attenuation and temperature

  15. Aquatic life protection index of an urban river Bacanga basin in northern Brazil, São Luís - MA

    OpenAIRE

    Duarte-dos-Santos,A. K.; Cutrim,M.V.J.; Ferreira,F.S.; R. Luvizotto-Santos; A. C. G. Azevedo-Cutrim; Araújo,B. O.; Oliveira,A. L. L.; J. A. Furtado; S. C. D. Diniz

    2017-01-01

    Abstract Bacanga River Basin faces environmental problems related to urbanization and discharge of untreated domestic sewage, which compromise its ecosystem health. Due to the small number of studies that assessed its water quality, the present study aimed to assess the current status of this ecosystem based on the aquatic life protection index. Samples were carried out every two months, in a total of six events, in six sites along the basin, where the water samples were collected to assess p...

  16. No evidence of exposure to environmental estrogens in two feral fish species sampled from the Yarra River, Australia: A comparison with Northern Hemisphere studies.

    Science.gov (United States)

    Hassell, Kathryn; Pettigrove, Vincent; Beresford, Nicola; Jobling, Susan; Kumar, Anu

    2016-09-01

    Environmental estrogens originate from a variety of sources including sewage treatment plant (STP) effluents and adverse physiological effects (endocrine disruption) have been observed in several fish species sampled downstream of STP discharges. In this study we examined common carp (Cyprinus carpio) and roach (Rutilis rutilis) for signs of exposure to environmental estrogens in the iconic Yarra River, Melbourne, Australia. The Yarra River flows through the city of Melbourne and more than 2 million people live within the catchment. Two STPs discharge water into the Yarra River within the middle reaches, and the areas immediately downstream of these discharge locations were the focus of this study. Carp and roach were chosen as test species since both have been utilised extensively for endocrine disruption research throughout Europe, North America and Asia, and data from various international studies was used for comparison with the results of the present study. Neither species showed evidence of exposure to environmental estrogens, with no elevation of plasma vitellogenin levels in males and no incidence of intersex gonads. Most physiological endpoints in both species from this study were within ranges reported in carp and roach from reference sites in other studies, however some degenerative histological changes in both male and female gonads were observed. Surface water samples showed no estrogenic activity (measured by the yeast-estrogen screen, YES), but did display strong anti-estrogenic and weak androgenic activity (measured by the yeast-androgen screen, YAS). Whilst the results show no evidence of impacts from environmental estrogens in the Yarra River, the presence of both anti-estrogenic and androgenic activity in water samples, as well as some gonadal changes in carp is concerning and indicates that our focus needs to broaden, in order to look for biological impacts in resident fauna that might be due to environmental pollutants other than environmental

  17. Processing of pine (Pinus sylvestris and birch (Betula pubescens leaf material in a small river system in the northern Cairngorms, Scotland

    Directory of Open Access Journals (Sweden)

    P. Collen

    2004-01-01

    Full Text Available Processing rates, and macroinvertebrate colonisation, of pine needles and birch leaves were studied at eight sites on the river Nethy, a small river system in the Cairngorm region of north-eastern Scotland. Throughout this river system, processing rates were slow for pine (k values 0.0015-0.0034 day-1 and medium to fast for birch (k values 0.0085-0.0331 day-1. Plecopteran shredders dominated both pine and birch leaf packs during the early part of the experiment while chironomids were more important in the latter stages. It is suggested that the slow processing rate of pine needles could adversely affect the productivity of streams, particularly where needles provide the major allochthonous energy source and retentive features are limited. Forest managers should consider this when creating new pinewoods in treeless areas as it will take many years for the trees to reach a size at which they can effectively contribute retentive features, in the form of woody debris, to streams. Keywords: leaf processing, pine needles, shredders, Pinus sylvestris, Betula pubescens, Scotland.

  18. Processing of pine (Pinus sylvestris) and birch (Betula pubescens) leaf material in a small river system in the northern Cairngorms, Scotland

    Science.gov (United States)

    Collen, P.; Keay, E. J.; Morrison, B. R. S.

    Processing rates, and macroinvertebrate colonisation, of pine needles and birch leaves were studied at eight sites on the river Nethy, a small river system in the Cairngorm region of north-eastern Scotland. Throughout this river system, processing rates were slow for pine (k values 0.0015-0.0034 day-1) and medium to fast for birch (k values 0.0085-0.0331 day-1). Plecopteran shredders dominated both pine and birch leaf packs during the early part of the experiment while chironomids were more important in the latter stages. It is suggested that the slow processing rate of pine needles could adversely affect the productivity of streams, particularly where needles provide the major allochthonous energy source and retentive features are limited. Forest managers should consider this when creating new pinewoods in treeless areas as it will take many years for the trees to reach a size at which they can effectively contribute retentive features, in the form of woody debris, to streams.

  19. 印度北方河流中主要鲤科鱼类卡拉(鱾)的年龄和生长%Age and growth profile of Indian major carps Catla catla from rivers of Northern India

    Institute of Scientific and Technical Information of China (English)

    Prashant K. DEEPAK; Uttam K. SARKAR; Raje S. NEGI; Samir K PAUL

    2008-01-01

    为了获得印度北部赣达(Ganga)盆地河流中野生卡特拉(鱾)种群的年龄结构和重要生长参数,对该鱼的年龄和生长进行了研究.鳞片取自商业捕捞和实验室饲养的样品.根据研究分析,该鱼最大年龄可达8龄;巴吉拉蒂河(Bhagirathi R.)的种群平均体长为521.51 mm,退算体长为288.9-1132.3 mm;旁遮普邦(Punjab)Satluj河种群平均体长为641.6 mm,退算体长为335.4-1096.08 mm.2龄时,种群线性生长率(Cl)和体重增加率(Cw)表现出迅速下降的趋势.其它生长参数值(Clt)也呈现快速下降.退算体长差异(ANOVA)分析显示,生活在赣达盆地不同流域中的种群,1+-4+龄组的长度差异较明显(P<0.05),高龄组(5+-8+)差异不显著.根据本项研究结果,提出了对印度北部赣达盆地相关河流中生活的野生卡特拉(鱾)种群资源持续利用的对策.%In the present communication age and growth of Catla catla (Hamilton-Buchanan 1822) was studied in order to obtain the information on its age structure and important growth parameters in the wild populations of rivers of the Ganga basin in the Northern India. Scales were collected from commercial and experimental catch. Based on the analysis we found C.catla with a maximum age group 8+ from river Bhagirathi where mean total length (TL) was 521.51 mm and the back calculated length were ranged from 288.9 to 1132.3 mm and from river Satluj, Punjab with a mean total length of 641.6 mm and back calculated length data were ranged from 335.4 to 1096.08 mm. The specific rate of linear growth (Cl) and specific rate of weight increase (Cw) of the entire population exhibited sharp decreasing trend in 2+ age group. The value of other growth parameter (Clt) showed an abrupt decreasing trend. Analyses of variances (ANOVA) of the back-calculated length data showed significant variation (P<0.05) in length attainment between the different drainages of river Ganga basin for the age groups up to 1+ to 4+ only, however, no

  20. Summary of surface-water-quality data collected for the Northern Rockies Intermontane Basins National Water-Quality Assessment Program in the Clark Fork-Pend Oreille and Spokane River basins, Montana, Idaho, and Washington, water years 1999-2001

    Science.gov (United States)

    Beckwith, Michael A.

    2003-01-01

    Water-quality samples were collected at 10 sites in the Clark Fork-Pend Oreille and Spokane River Basins in water years 1999 – 2001 as part of the Northern Rockies Intermontane Basins (NROK) National Water-Quality Assessment (NAWQA) Program. Sampling sites were located in varied environments ranging from small streams and rivers in forested, mountainous headwater areas to large rivers draining diverse landscapes. Two sampling sites were located immediately downstream from the large lakes; five sites were located downstream from large-scale historical mining and oreprocessing areas, which are now the two largest “Superfund” (environmental remediation) sites in the Nation. Samples were collected during a wide range of streamflow conditions, more frequently during increasing and high streamflow and less frequently during receding and base-flow conditions. Sample analyses emphasized major ions, nutrients, and selected trace elements. Streamflow during the study ranged from more than 130 percent of the long-term average in 1999 at some sites to 40 percent of the long-term average in 2001. River and stream water in the study area exhibited small values for specific conductance, hardness, alkalinity, and dissolved solids. Dissolved oxygen concentrations in almost all samples were near saturation. Median total nitrogen and total phosphorus concentrations in samples from most sites were smaller than median concentrations reported for many national programs and other NAWQA Program study areas. The only exceptions were two sites downstream from large wastewater-treatment facilities, where median concentrations of total nitrogen exceeded the national median. Maximum concentrations of total phosphorus in samples from six sites exceeded the 0.1 milligram per liter threshold recommended for limiting nuisance aquatic growth. Concentrations of arsenic, cadmium, copper, lead, mercury, and zinc were largest in samples from sites downstream from historical mining and ore

  1. Aquatic life protection index of an urban river Bacanga basin in northern Brazil, São Luís - MA

    Directory of Open Access Journals (Sweden)

    A. K. Duarte-dos-Santos

    Full Text Available Abstract Bacanga River Basin faces environmental problems related to urbanization and discharge of untreated domestic sewage, which compromise its ecosystem health. Due to the small number of studies that assessed its water quality, the present study aimed to assess the current status of this ecosystem based on the aquatic life protection index. Samples were carried out every two months, in a total of six events, in six sites along the basin, where the water samples were collected to assess physicochemical parameters and calculate the trophic state index and the index of minimum parameters for the protection of aquatic communities. The data were also compared with values determined by the resolution National Environment Council - CONAMA 357/05. Our results reveal significant changes in the water quality of Bacanga River Basin. An increase in nutrients and chlorophyll-a concentration led it to eutrophication. The surfactant values were high and put in danger the aquatic biota. Dissolved oxygen rates were below the values allowed by the resolution in most sites sampled. The current water quality is terrible for the protection of aquatic life in 61.92% of the sites sampled.

  2. Aquatic life protection index of an urban river Bacanga basin in northern Brazil, São Luís - MA.

    Science.gov (United States)

    Duarte-Dos-Santos, A K; Cutrim, M V J; Ferreira, F S; Luvizotto-Santos, R; Azevedo-Cutrim, A C G; Araújo, B O; Oliveira, A L L; Furtado, J A; Diniz, S C D

    2017-01-01

    Bacanga River Basin faces environmental problems related to urbanization and discharge of untreated domestic sewage, which compromise its ecosystem health. Due to the small number of studies that assessed its water quality, the present study aimed to assess the current status of this ecosystem based on the aquatic life protection index. Samples were carried out every two months, in a total of six events, in six sites along the basin, where the water samples were collected to assess physicochemical parameters and calculate the trophic state index and the index of minimum parameters for the protection of aquatic communities. The data were also compared with values determined by the resolution National Environment Council - CONAMA 357/05. Our results reveal significant changes in the water quality of Bacanga River Basin. An increase in nutrients and chlorophyll-a concentration led it to eutrophication. The surfactant values were high and put in danger the aquatic biota. Dissolved oxygen rates were below the values allowed by the resolution in most sites sampled. The current water quality is terrible for the protection of aquatic life in 61.92% of the sites sampled.

  3. Evaluation of soil erosion as a basis of sediment yield in mountainous catchments: a preliminary study in the River Douro Basin (Northern Portugal)

    Science.gov (United States)

    Reis, Anabela; Martinho Lourenço, José M.; Parker, Andrew; Alencoão, Ana

    2013-04-01

    The River Corgo drains a meso-scale mountainous rural catchment with an area of 295 km2, underlain by crystalline rocks, in a temperate climate, which integrates the transboundary River Douro Basin, in the northeast of Portugal. A geochemical survey on oxic fluvial sediments of the river network shows considerable contents of metals associated to the finer particles (soils and weathering products. Moreover, taking into account the hydrological pattern of the catchment, the seasonal and spatial variability of metal contents associated to the sediments suggests that the control of metal in the sediments by their mineralogical, geochemical and physical properties is governed primarily at the level of the basin soils system, especially in the Wet Period, when the sediments are frequently remobilised (Reis, 2010). Although the soil particles are a common pathway of transport and entrance of metals in the fluvial network by runoff derived erosion, this mechanism is naturally more marked in mountainous catchments. Modelling sediment and adsorbed contaminant transport within catchments can help to identify possible contaminant sources, as well as to estimate the delivered quantities of eroded material and associated contaminants. In catchments with the described morphological features, monitoring the transport of sediments poses some issues concerning: (a) the low mass yield of suspended sediment from river water, under low-flow conditions; (b) the maintenance of the sediment sampler's devices in the streams, in periods of high-flow or storm events. This study describes the preliminary results of a GIS-based mass balance model of overland sediment transport to the River. The erosion, the first step of sediment transport, was estimated by an empirical model - The Universal Soil Loss Equation (USLE). The objective was to construct a GIS based potential soil loss spatial index model and posteriorly estimate the sediment yield for different locations within the catchment. The

  4. Depositional architecture and evolution of inner shelf to shelf edge delta systems since the Late Oliocene and their respone to the tectonic and sea level change, Pear River Mouth Basin, northern South China Sea

    Science.gov (United States)

    Lin, Changsong; Zhang, Zhongtao; liu, Jingyan; Jiang, Jing

    2016-04-01

    The Pear River Mouth Basin is located in the northern continent margin of the South China Sea. Since the Late Oligocene, the long-term active fluvial systems (Paleo-Zhujiang) from the western basin margin bebouched into the northern continental margin of the South China Sea and formed widespread deltaic deposits in various depositional geomorphologies and tectonic settings. Based of integral analysys of abundant seismic, well logging and drilling core data, Depositional architecture and evolution of these delta systems and their respone to the tectonic and sea level change are documented in the study. There are two basic types of the delta systems which have been recognized: inner shelf delta deposited in shallow water enviroments and the outer shelf or shelf-edge delta systems occurred in deep water settings. The paleowater depths of these delta systems are around 30 to 80m (inner shelf delta) and 400-1000m (shelf-edge delta) estimated from the thickness (decompaction) of the delta front sequences. The study shows that the inner shelf delta systems are characterized by relatively thin delta forests (20-40m), numereous stacked distributary channel fills, relative coarse river mouth bar deposits and thin distal delta front or distal bar and prodelta deposits. In contrast, the outer shelf or shelf edge delta systems are characteristic of thick (300-800m) and steep (4-60) of deltaic clinoforms, which commonly display in 3D seismic profiles as "S" shape reflection. Large scale soft-sediment deformation structures, slump or debris flow deposits consisting mainly of soft-sediment deformed beds, blocks of sandstones and siltstones or mudstones widely developed in the delta front deposits. The shelf edge delta systems are typically associated with sandy turbidite fan deposits along the prodelta slopes, which may shift basinwards as the progradation of the delta systems. The delta systems underwent several regional cycles of evolution from inner shelf deltas to shelf edge

  5. The recent record of climate on the range of the George River Caribou Herd, Northern Québec and Labrador, Canada

    Directory of Open Access Journals (Sweden)

    J.D. Jacobs

    1996-01-01

    Full Text Available Records from permanent meteorological stations in and around the range of the George River Caribou Herd have been analyzed for the 1950-1991 period in order to identify climatic factors potentially influencing the numbers, condition, and distribution of caribou. Winter conditions identified include a significant temperature decrease over the period and some years of extreme snowfall. Spatial variations in snow cover may be responsible for shifts in winter range. Indications are that summer climate has not varied significantly, but spring and summer conditions may not have been particularly favourable for plant productivity in the summer range of females and calves. Climatological observations more representative of the summer range are needed for a better understanding of ecological relationships there.

  6. [Peculiarities of the parasitofauna of Atlantic salmon parr (Salmo salar L.), brown trout (Salmo truttae L.), and char (Salvelinus alpinus L.) in the Utsjoki River system (Northern Finland)].

    Science.gov (United States)

    Ieshko, E P; Barskaia, Iu Iu; Lebedeva, D I; Novokhatskaia, O V; Kaukoranta, M; Niemela, E

    2011-01-01

    Data on the parasite diversity in Salmonidae fish parr from different parts of the Utsjoki River obtained during 1993-1995 and 2006-2007 are presented. Three fish species, Salmo salar L., S. truttae L., and Salvelinus alpinus L., were examined on the presence of helminthes. Twenty species of salmon parasites were found, the majority of which are the parasites with complicated life cycles. Infusorians C apriniana piscium, myxosporidia Chloromyxum januaricus and Myxobolus neurobius, metacercaria of the genera Diplostomum and Apatemon, and the nematode Raphidascaris acus larvae were the most numerous in salmon parasite fauna. Brown trout had the most number of specific parasite species, whereas char was infested by protozoan parasites only.

  7. River response to climate and sea level changes during the Late Saalian/Early Eemian in northern Poland – a case study of meandering river deposits in the Chłapowo cliff section

    Directory of Open Access Journals (Sweden)

    Moskalewicz Damian

    2016-03-01

    Full Text Available Fluvial sediments in the Chłapowo cliff section were studied in order to reconstruct their palaeoflow conditions and stratigraphical position. Lithofacies, textural and palaeohydraulic analyses as well as luminescence dating were performed so as to achieve the aim of study. Sedimentary successions were identified as a record of point bar cycles. The fluvial environment probably functioned during the latest Saalian, shortly after the retreat of the Scandinavian Ice Sheet. Discharge outflow was directed to the northwest. The river used the older fluvioglacial valley and probably was directly connected to the Eem Sea. Good preservation and strong aggradation of point-bar cycles were related to a rapid relative base level rise. The meandering river sediments recognised showed responses to climate and sea level changes as illustrated by stratigraphical, morphological and sedimentological features of the strata described. The present study also revealed several insights into proper interpretation of meandering fluvial successions, in which the most important were: specific lithofacies assemblage of GSt (St, Sp → Sl → SFrc → Fm (SFr and related architectural elements: channel/sandy bedforms CH/SB → lateral accretion deposits LA → floodplain fines with crevasse splays FF (CS; upward-fining grain size and decreasing content of denser heavy minerals; estimated low-energy flow regime with a mean depth of 1.6–3.3 m, a Froude number of 0.2–0.4 and a sinuosity of 1.5.

  8. 文学人类学视角下《北方的河》及其文化价值解读%A Study of Northern Rivers from the Perspective of Literary Anthropology

    Institute of Scientific and Technical Information of China (English)

    孙旭

    2015-01-01

    文学人类学是文学和人类学两个不同学科的交叉与结合,它特有的文化品质在于关注全人类的情感与命运.鲜明的文学人类学意识渗透于回族作家张承志的小说《北方的河》中,促成了张承志对"文化重建"的文学资源取向的寻求.这种文学人类学书写实现了中国少数民族文学领域上的"超越",是张承志进行的富有成效的探索,并且颇具当下意义.%Literary anthropology is in fact a combination of literature and anthropology, its unique cultural quality being the focus on emotions and fate of mankind. The Hui nationality writer Zhang Cheng-zhi's novel Northern Rivers contains vivid awareness of literary anthropology, which highlights the writer's desire to seek the resource orientation of"cultural reconstruction"in literature. Zhang's literary anthropology writing has achieved successful transcendence in the Chinese ethnic literature, thus has practical significance presently.

  9. Trophic preference and preliminary indication of phylloplane fungal influence on the diet of the non-native Gammarus roeselii Gervais 1835 (Amphipoda, Gammaridae in the sub-lacustrine Ticino river basin (Lombardy, Northern Italy

    Directory of Open Access Journals (Sweden)

    Daniele Paganelli

    2017-03-01

    Full Text Available Gammarids are one of the most successful invaders in freshwater ecosystems due to both their diet plasticity and high reproductive capacity. One such amphipod, Gammarus roeselii, has recently colonised the southern part of the sub-lacustrine Ticino River basin (Northern Italy, where its ecological niche overlaps with the native species Echinogammarus stammeri. In the present paper the food preferences of G. roeselii have been investigated, testing the palatability of different food sources: three macrophytes and three different leaf debris. Moreover, an explorative mycological analysis on the three different leaf debris used in the experiment has been performed. Results of the short-term experiment suggest that aquatic plants are less palatable than allocthonous detritus, probably because they can contain secondary metabolites (i.e. tannins and they have lower nutrient tissues with very high water content. On the contrary, G. roeselii showed a clear preference for the oak leaves, resulted colonized by a more abundant fungal biomass and, therefore, more palatable too.

  10. In vivo induction of antioxidant response and oxidative stress associated with genotoxicity and histopathological alteration in two commercial fish species due to heavy metals exposure in northern India (Kali) river.

    Science.gov (United States)

    Fatima, Mahino; Usmani, Nazura; Firdaus, Fakiha; Zafeer, Mohammad Faraz; Ahmad, Shafeeque; Akhtar, Kafil; Dawar Husain, S M; Ahmad, Mir Hilal; Anis, Ehraz; Mobarak Hossain, M

    2015-01-01

    Heavy metals can significantly bioaccumulate in fish tissues. The step wise mechanism of heavy metal toxicities on fish health is still limited. The present study assessed the tissue-specific antioxidant response and oxidative stress biomarkers of commercially important fish species namely, Channa striatus and Heteropneustes fossilis inhabiting Kali River of northern India where heavy-metal load is beyond the World Health Organisation - maximum permissible limits. Heavy metals chromium (Cr), nickel (Ni), lead (Pb) and cadmium (Cd) were elevated in both fish species compared to recommended values of the Federal Environmental Protection Agency (FEPA), 1999 for edible fishes. Reduced glutathione (GSH), superoxide dismutase (SOD) and catalase (CATA) activities in all tissues (brachial, neural, renal and hepatic) were altered. Cellular lipid and protein compromisation in both fishes induced by heavy metals was determined by lipid peroxidation (LPO) and protein carbonylation (PC) assays. Micronucleus (MN) test of erythrocytes and comet assay of liver cells confirmed genotoxicity. Histopathology of the liver, kidney and brain of affected fishes was distorted significantly with its reference fishes thereby affecting the quality and quantity of these fish stocks. This raises a serious concern as these fishes are consumed by the local population which would ultimately affect human health.

  11. Late Quaternary vegetation and climate history of a perennial river canyon in the Rīo Salado basin (22°S) of Northern Chile

    Science.gov (United States)

    Latorre, Claudio; Betancourt, Julio L.; Arroyo, Mary T.K.

    2006-01-01

    Plant macrofossils from 33 rodent middens sampled at three sites between 2910 and 3150 m elevation in the main canyon of the Rīo Salado, northern Chile, yield a unique record of vegetation and climate over the past 22,000 cal yr BP. Presence of low-elevation Prepuna taxa throughout the record suggests that mean annual temperature never cooled by more than 5°C and may have been near-modern at 16,270 cal yr BP. Displacements in the lower limits of Andean steppe and Puna taxa indicate that mean annual rainfall was twice modern at 17,520-16,270 cal yr BP. This pluvial event coincides with infilling of paleolake Tauca on the Bolivian Altiplano, increased ENSO activity inferred from a marine core near Lima, abrupt deglaciation in southern Chile, and Heinrich Event 1. Moderate to large increases in precipitation also occurred at 11,770-9550 (Central Atacama Pluvial Event), 7330-6720, 3490-2320 and at 800 cal yr BP. Desiccation occurred at 14,180, 8910-8640, and 4865 cal yr BP. Compared to other midden sites in the region, early Holocene desiccation seems to have happened progressively earlier farther south. Emerging trends from the cumulative midden record in the central Atacama agree at millennial timescales with improved paleolake chronologies for the Bolivian Altiplano, implying common forcing through changes in equatorial Pacific sea-surface temperature gradients.

  12. An evaluation of ISOCLS and CLASSY clustering algorithms for forest classification in northern Idaho. [Elk River quadrange of the Clearwater National Forest

    Science.gov (United States)

    Werth, L. F. (Principal Investigator)

    1981-01-01

    Both the iterative self-organizing clustering system (ISOCLS) and the CLASSY algorithms were applied to forest and nonforest classes for one 1:24,000 quadrangle map of northern Idaho and the classification and mapping accuracies were evaluated with 1:30,000 color infrared aerial photography. Confusion matrices for the two clustering algorithms were generated and studied to determine which is most applicable to forest and rangeland inventories in future projects. In an unsupervised mode, ISOCLS requires many trial-and-error runs to find the proper parameters to separate desired information classes. CLASSY tells more in a single run concerning the classes that can be separated, shows more promise for forest stratification than ISOCLS, and shows more promise for consistency. One major drawback to CLASSY is that important forest and range classes that are smaller than a minimum cluster size will be combined with other classes. The algorithm requires so much computer storage that only data sets as small as a quadrangle can be used at one time.

  13. Middle Miocene reworked turbidites in the Baiyun Sag of the Pearl River Mouth Basin, northern South China Sea margin: Processes, genesis, and implications

    Science.gov (United States)

    Gong, Chenglin; Wang, Yingmin; Zheng, Rongcai; Hernández-Molina, F. Javier; Li, Yun; Stow, Dorrik; Xu, Qiang; Brackenridge, Rachel E.

    2016-10-01

    Our understanding of reworked turbidites is still in its infancy, and their flow processes and genesis still remain understudied. Core data from the middle Miocene Zhujiang Formation in the Pearl River Mouth Basin allow us to differentiate reworked turbidites, yielding two main contributions. Firstly, reworked turbidites are distinguished from turbidites by the association of traction structures and tidal signatures, which occur in discrete units rather than forming a classic "Bouma Sequence" for turbidites. Sedimentological characteristics of reworked turbidites proposed here will help to obtain a robust set of diagnostic criteria for the recognition of deep-water non-turbidite deepwater units as reservoirs. Secondly, our results suggest that, in the down-slope direction, classic detritus carried in turbidity flows would synchronously be bidirectionally reworked by internal tides and waves, resulting in tidal signatures seen in the interpreted reworked turbidites. In the along-slope direction, upper parts of dilute turbidity currents would mix vertically with seawater, and muddy fines would be winnowed away by contour currents, whereas lower parts of dilute turbidity currents would probably drop their coarse particles, resulting in traction structures recognized in the documented reworked turbidites. Our work highlights the influence of bottom currents on the development and modification of turbidites and suggests that reworked turbidites were created by the combined action of down-slope transport and reworking and along-slope winnowing and sorting, helping to better understand flow processes and genesis of non-turbidite reservoirs with a great economic interest.

  14. The radiological impact of phosphogypsum stockpile in Wiślinka (northern Poland) on the Martwa Wisła river water.

    Science.gov (United States)

    Olszewski, Grzegorz; Boryło, Alicja; Skwarzec, Bogdan

    The aim of this work was to determine the concentrations of uranium ((234)U, (235)U, (238)U), polonium ((210)Po) and lead ((210)Pb) radioisotopes in water samples and to explore the impact of the phosphogypsum stack on the Martwa Wisła waters. The (238)U, (210)Po and (210)Pb concentrations in analyzed water samples reached maximum values of 11.7 ± 0.3, 2.0 ± 0.1 and 3.2 ± 0.1 mBq L(-1) and activity ratios were maximally 1.18 ± 0.01 for (234)U/(238)U, 0.041 ± 0.018 for (235)U/(238)U and 0.69 ± 0.10 for (210)Po/(210)Pb. The obtained results suggest that this impact is rather insignificant and does not affect significantly the Martwa Wisła river.

  15. NORTHERN TANZANIA

    African Journals Online (AJOL)

    inertia, water balance, physiological strength, and susceptibility to predation between adults .... Judd PW and Rose FL 1977 Aspects of the thermal biology of the Texas tortoise ... pctrdolis lmheoeki) and their conservation in northern Tanzania.

  16. Carbon, oxygen and strontium isotopic constraints on fluid sources, temperatures and biogeochemical processes during the formation of seep carbonates - Secchia River site, Northern Apennines

    Science.gov (United States)

    Viola, Irene; Capozzi, Rossella; Bernasconi, Stefano M.; Rickli, Jörg

    2017-07-01

    Understanding authigenic seep carbonate formation provides clues for hydrocarbon exploration and insights into contributions to gas budgets of marine environments and the atmosphere. Seep carbonates discovered in the outcropping succession along the Secchia riverbanks (near Modena, Italy) belong to the Argille Azzurre Formation of Early Pleistocene age deposited in an upper shelf environment overlying the Miocene foredeep successions, which include hydrocarbon fields. The fluid migration from the hydrocarbon fields, up to the surface, is presently active on land and started in the marine succession during the Late Miocene. Authigenic globular carbonate concretions and carbonate chimneys are interspersed along the strata throughout the section. A comprehensive geochemical characterisation of the carbonates has been carried out to understand the processes leading to their formation. The carbonate concretions are the record of past hydrocarbon vents linked to the Miocene petroleum system of the Northern Apennines. The samples are composed of > 50% microcrystalline dolomite. The δ13C signatures identify two groups in the samples according to different type of formation processes. Globular concretions have positive values that suggest an influence of CO2 associated to secondary methanogenesis due to microbial degradation of higher hydrocarbons. The analysed chimney, with negative δ13C values, is interpreted as former conduit where carbonate precipitation is promoted by Anaerobic Oxidation of Methane coupled with Sulfate Reduction. The δ18O range, coupled with 87/86Sr signatures, indicate that the contribution of deep connate water from the Miocene reservoirs is up to 23% during the formation of the globular concretions. The connate water occurrence is also documented by higher ambient temperatures. The different isotope signatures in seep carbonates result from the relative contribution of the recognised gas and water components, linked to different plumbing systems

  17. Field testing and adaptation of a methodology to measure "in-stream" values in the Tongue River, northern Great Plains (NGP) region

    Science.gov (United States)

    Bovee, Ken D.; Gore, James A.; Silverman, Arnold J.

    1978-01-01

    A comprehensive, multi-component in-stream flow methodology was developed and field tested in the Tongue River in southeastern Montana. The methodology incorporates a sensitivity for the flow requirements of a wide variety of in-stream uses, and the flexibility to adjust flows to accommodate seasonal and sub-seasonal changes in the flow requirements for different areas. In addition, the methodology provides the means to accurately determine the magnitude of the water requirement for each in-stream use. The methodology can be a powerful water management tool in that it provides the flexibility and accuracy necessary in water use negotiations and evaluation of trade-offs. In contrast to most traditional methodologies, in-stream flow requirements were determined by additive independent methodologies developed for: 1) fisheries, including spawning, rearing, and food production; 2) sediment transport; 3) the mitigation of adverse impacts of ice; and 4) evapotranspiration losses. Since each flow requirement varied in important throughout the year, the consideration of a single in-stream use as a basis for a flow recommendation is inadequate. The study shows that the base flow requirement for spawning shovelnose sturgeon was 13.0 m3/sec. During the same period of the year, the flow required to initiate the scour of sediment from pools is 18.0 m3/sec, with increased scour efficiency occurring at flows between 20.0 and 25.0 m3/sec. An over-winter flow of 2.83 m3/sec. would result in the loss of approximately 80% of the riffle areas to encroachment by surface ice. At the base flow for insect production, approximately 60% of the riffle area is lost to ice. Serious damage to the channel could be incurred from ice jams during the spring break-up period. A flow of 12.0 m3/sec. is recommended to alleviate this problem. Extensive ice jams would be expected at the base rearing and food production levels. The base rearing flow may be profoundly influenced by the loss of streamflow

  18. Analysis and detection of functional outliers in water quality parameters from different automated monitoring stations in the Nalón river basin (Northern Spain).

    Science.gov (United States)

    Piñeiro Di Blasi, J I; Martínez Torres, J; García Nieto, P J; Alonso Fernández, J R; Díaz Muñiz, C; Taboada, J

    2015-01-01

    The purposes and intent of the authorities in establishing water quality standards are to provide enhancement of water quality and prevention of pollution to protect the public health or welfare in accordance with the public interest for drinking water supplies, conservation of fish, wildlife and other beneficial aquatic life, and agricultural, industrial, recreational, and other reasonable and necessary uses as well as to maintain and improve the biological integrity of the waters. In this way, water quality controls involve a large number of variables and observations, often subject to some outliers. An outlier is an observation that is numerically distant from the rest of the data or that appears to deviate markedly from other members of the sample in which it occurs. An interesting analysis is to find those observations that produce measurements that are different from the pattern established in the sample. Therefore, identification of atypical observations is an important concern in water quality monitoring and a difficult task because of the multivariate nature of water quality data. Our study provides a new method for detecting outliers in water quality monitoring parameters, using turbidity, conductivity and ammonium ion as indicator variables. Until now, methods were based on considering the different parameters as a vector whose components were their concentration values. This innovative approach lies in considering water quality monitoring over time as continuous curves instead of discrete points, that is to say, the dataset of the problem are considered as a time-dependent function and not as a set of discrete values in different time instants. This new methodology, which is based on the concept of functional depth, was applied to the detection of outliers in water quality monitoring samples in the Nalón river basin with success. Results of this study were discussed here in terms of origin, causes, etc. Finally, the conclusions as well as advantages of

  19. Local seismicity in the area of Tornio River (northern Fennoscandia) revealed by analysis of local events registered by the POLENET/LAPNET array

    Science.gov (United States)

    Kozlovskaya, E.; Usoltseva, O.; Konstantinovskaya, N.

    2012-04-01

    The region of Tornio river (22-26 deg E and 66.5-69 deg N) is very interesting for seismological studies because it is crossed by systems of tectonic faults spreading in two different directions. 56 local earthquakes originated from this region were recorded by the POLENET/LAPNET temporary array from May, 2007 to May, 2009. Hypocenter depths of earthquakes are in the range of 1-35 km and their magnitudes vary from 0.8 to 2.2. For events detection we used the bulletin of the Institute of Seismology (Helsinki university) and Norway Global Beam Forming bulletin, compiled on the base of automatic detection of events, using the data of Noress, Arcess, Finess, SPA, HFS, APA arrays. In addition to local earthquakes, the array recorded 364 blasts from this region during the POLENET/LAPNET observation period. The events were relocated using manually measured travel times of refracted P waves from events at local distances (less than 200 km) and the 1-D velocity model along the wide-angle reflection and refraction HUKKA profile. The epicenters of relocated events show good correlation with known faults in the region. For each earthquake we constructed travel-time curves with reduction velocity of 8 km/s and compared them with the theoretical travel-time curves, in order to avoid phase misinterpretation. We found out that the largest reduction of travel time residuals during relocation was reached for deep earthquakes, due to more precise depth determination. The other aim of our study was to estimate what part of travel time residuals is not connected with the reference 1D velocity model and accuracy of location, but is rather due to 3-D heterogeneities in the crust. We also analyzed the amplitude characteristics of P-wave arrivals from different layers in the crust and upper mantle and also compared spectrograms of deep earthquakes, shallow earthquakes and blasts.

  20. Taphonomy and paleoecology of nonmarine mollusca: indicators of alluvial plain lacustrine sedimentation, upper part of the Tongue River Member, Fort Union Formation ( Paleocene), Northern Powder River Basin, Wyoming and Montana ( USA).

    Science.gov (United States)

    Hanley, J.H.; Flores, R.M.

    1987-01-01

    The composition, species abundances, and spatial and temporal distributions of mollusc assemblages were controlled by the environments in which they lived and the depositional processes that affected the molluscs after death and before final burial. Post-mortem transport, reworking and concentration of shells, and mixing of faunal elements from discrete habitats produced a taphonomic 'overprint' on assemblage characteristics that directly reflects the processes of alluvial plain and floodbasin lacustrine sedimentation. The 'overprint' can be interpreted from outcrop analysis of molluscan biofabric, which consists of: 1) orientation, fragmentation, size-sorting, abrasion, density, and dispersion of shells, 2) the nature and extent of shell-infilling, and 3) ratio of articulated to disarticulated bivalves. Taphonomic characteristics were used with sedimentological properties to differentiate in-place, reworked, transported, and ecologically mixed mollusc assemblages. This study also defines the paleoecology of habitat preferences of mollusc species as a basis for recognition of the environments in which these assemblages were deposited: 1) large floodbasin lakes, 2) small floodbasin lakes, and 3) crevasse deltas and splays. Integration of sedimentology and paleoecology provides an interdisciplinary approach to the interpretation of alluvial environments through time in the Tongue River Member. -Authors

  1. Frozen ponds: production and storage of methane during the Arctic winter in a lowland tundra landscape in northern Siberia, Lena River Delta

    Directory of Open Access Journals (Sweden)

    M. Langer

    2014-07-01

    Full Text Available Lakes and ponds play a key role in the carbon cycle of permafrost ecosystems, where they are considered to be hotspots of carbon dioxide CO2 and methane CH4 emission. The strength of these emissions is, however, controlled by a variety of physical and biogeochemical processes whose responses to a warming climate are complex and only poorly understood. Small waterbodies have been attracting an increasing amount of attention since recent studies demonstrated that ponds can make a significant contribution to the CO2 and CH4 emissions of tundra ecosystems. Waterbodies also have a marked effect on the thermal state of the surrounding permafrost; during the freezing period they prolong the period of time during which thawed soil material is available for microbial decomposition. This study presents net CH4 production rates during the freezing period from ponds within a typical lowland tundra landscape in northern Siberia. Rate estimations were based on CH4 concentrations measured in surface lake ice from a variety of waterbody types. Vertical profiles along ice blocks showed an exponential increase in CH4 concentration with depth. These CH4 profiles were reproduced by a 1-D mass balance model and the net CH4 production rates then inferred through inverse modeling. Results revealed marked differences in early winter net CH4 production among various ponds. Initial state ponds underlain by stable permafrost with little or no signs of degradation yielded low net production rates, of the order of 10–11 to 10–10 mol m−2 s−1 (0.01 to 0.14 mgCH4 m−2 d−1. In contrast, advanced state ponds exhibiting clear signs of thermal erosion yielded net CH4 production rates of the order of 10–7 mol m−2 s−1 (140 mgCH4 m−2 d−1. The net production rate per square meter of advanced state ponds exceeded the maximum summer CH4 emission rates per square meter which was measured for the average tundra landscape at the study site. Our results therefore

  2. Site selection assessment for river drinking source water of a city in northern%北方某城市河流型饮用水水源地选址方案评价研究

    Institute of Scientific and Technical Information of China (English)

    杜大仲; 孟宪林; 马放

    2012-01-01

    为建立和量化适于河流型饮用水水源地选址的评价体系,以北方某城市A的水源地选址方案为研究对象,通过层次分析法(AHP)从法律制约、环境质量、水资源保障和环境风险角度构建评价体系.评价体系共设立8个否定因子和20个评价因子,采用文献分析和专家问卷调查相结合的方法确定评价因子权重,并依据环境标准和技术导则确定评分标准,可对多个选址方案进行评价与优选.研究表明,城市A的选址方案Ⅰ与方案Ⅱ 均可做为水源地选址方案进行工程论证;城市A所处流域综合水质状况不佳,在后续的给水厂建设中应考虑采用深度处理工艺;城市A的选址方案Ⅰ与方案Ⅱ的环境风险系数均较高,管理部门应依据选址方案的风险特征加强上游风险源管理.%In order to establish and quantize the assessment system for the site selection of river drinking source water, City A in northern was took as the case. The assessment system which involve law, environmental quality, water resources protection and environmental risk was established by analytic hierarchy process (AHP). There were eight negative factors and twenty evaluation factors in the system, and the weight of evaluation factors were defined by literature review and expert survey. These evaluation factors were quantized according to environmental standards and technical guidelines. Both program I and II of City A can be carried engineering appraisal out; the water quality of river basin was no good, so the advanced treatment process should be considered in the construction of water plant; the environmental risk index of program I and II were high, administration should strengthen the management of risk source on the risk characteristics.

  3. Palaeoenvironment and dating of the Early Acheulean localities from the Somme River basin (Northern France): New discoveries from the High Terrace at Abbeville-Carrière Carpentier

    Science.gov (United States)

    Antoine, Pierre; Moncel, Marie-Hélène; Limondin-Lozouet, Nicole; Locht, Jean-Luc; Bahain, Jean-Jacques; Moreno, Davinia; Voinchet, Pierre; Auguste, Patrick; Stoetzel, Emmanuelle; Dabkowski, Julie; Bello, Silvia M.; Parfitt, Simon A.; Tombret, Olivier; Hardy, Bruce

    2016-10-01

    stratigraphy, ESR and ESR/U-series dating results, and biostratigraphic data, the fluvial deposits of the White Marl can be securely attributed to MIS 15. In addition, some Acheulean bifaces were discovered at the base of the slope deposits, directly overlying the fluvial sequence. These artefacts are most likely coeval with the end of MIS 15 or an early stage of MIS 14, between 550 and 500 ka, and represent, together with the artefacts from Amiens "Rue du Manège", the oldest in situ evidence of Acheulean occupation in Northern France. However, no unquestionable artefacts have been discovered in the White Marl or in the underlying gravel layer. These discoveries contribute to the chronology of the earliest evidence of hominin occupations in north-western Europe which may be related to Homo heidelbergensis.

  4. LAND USE AND ITS DRIVING FORCES AT VILLAGE SCALE IN NUJIANG RIVER WATERSHED OF NORTHERN YUNNAN%怒江云南北段的村域土地利用及驱动力分析

    Institute of Scientific and Technical Information of China (English)

    赵莉莉; 杨文忠; 孟广涛; 范勋承

    2012-01-01

    Driving forces analysis is imperative in the study of land-use/cover changes (LUCC). We carried out a study on LUCC and its driving forces at village scale. Study pilots were 4 communities adjacent to the Gaoligongshan Nature Reserve in Nujiang River watershed of Northern Yunnan. SPOT-5 remote sensing images combining with field investigation were used to classify land use types and create classification system. Land use patterns and characteristics at village scale were analyzed by using Fragstats 3. 3. Meanwhile, socioeconomic data were obtained through household survey, semi-structure interviewing, and questionnaires. Relationship between land use pattern and socioeconomic status was built to analyze driving forces of LUCC. Results showed that land use was driven mainly by natural conditions,villagers' education level, and social customs. At the same time, households' cash incomes depended strongly upon extensive land uses. Study results provide quantified information for land resource management and village economic development in Nujiang River Watershed of Northern Yunnan. Methods we adopt can be used as a reference for LUCC studies at local scale.%驱动力分析是土地利用研究的重要内容。选择怒江流域北段高黎贡山自然保护区周边4个自然村为研究对象,应用高分辨率SPOT-5遥感影像数据,结合实地逐块核实,对土地利用/覆被进行分类,并建立土地利用类型分类系统,用Fragstats 3.3分析得到村域土地利用格局和特征;同时,采用入户调查、半结构访谈和问卷调查等方法,获得的村域详细社会经济数据,建立土地利用与社会经济之间的关联,分析村域土地利用的驱动力。结果显示:村域土地利用主要受自然条件、受教育程度、生活习俗等因子的驱动,且经济收入主要依赖于粗放的土地利用。研究结果能为怒江云南北段的土地资源合理利用和村域经济发展提供数据支持;研究方法

  5. Geochemical reanalysis of historical U.S. Geological Survey sediment samples from the Inmachuk, Kugruk, Kiwalik, and Koyuk River drainages, Granite Mountain, and the northern Darby Mountains, Bendeleben, Candle, Kotzebue, and Solomon quadrangles, Alaska

    Science.gov (United States)

    Werdon, Melanie B.; Granitto, Matthew; Azain, Jaime S.

    2015-01-01

    The State of Alaska’s Strategic and Critical Minerals (SCM) Assessment project, a State-funded Capital Improvement Project (CIP), is designed to evaluate Alaska’s statewide potential for SCM resources. The SCM Assessment is being implemented by the Alaska Division of Geological & Geophysical Surveys (DGGS), and involves obtaining new airborne-geophysical, geological, and geochemical data. As part of the SCM Assessment, thousands of historical geochemical samples from DGGS, U.S. Geological Survey (USGS), and U.S. Bureau of Mines archives are being reanalyzed by DGGS using modern, quantitative, geochemical-analytical methods. The objective is to update the statewide geochemical database to more clearly identify areas in Alaska with SCM potential. The USGS is also undertaking SCM-related geologic studies in Alaska through the federally funded Alaska Critical Minerals cooperative project. DGGS and USGS share the goal of evaluating Alaska’s strategic and critical minerals potential and together created a Letter of Agreement (signed December 2012) and a supplementary Technical Assistance Agreement (#14CMTAA143458) to facilitate the two agencies’ cooperative work. Under these agreements, DGGS contracted the USGS in Denver to reanalyze historical USGS sediment samples from Alaska. For this report, DGGS funded reanalysis of 653 historical USGS sediment samples from the statewide Alaska Geochemical Database Version 2.0 (AGDB2; Granitto and others, 2013). Samples were chosen from an area covering portions of the Inmachuk, Kugruk, Kiwalik, and Koyuk river drainages, Granite Mountain, and the northern Darby Mountains, located in the Bendeleben, Candle, Kotzebue, and Solomon quadrangles of eastern Seward Peninsula, Alaska (fig. 1). The USGS was responsible for sample retrieval from the National Geochemical Sample Archive (NGSA) in Denver, Colorado through the final quality assurance/quality control (QA/QC) of the geochemical analyses obtained through the USGS contract

  6. PALEOEARTHQUAKE EVENTS AND FORMATION OF RIVER TERRACES IN ACTIVE ANTICLINE REGION,NORTHERN PIEDMONT OF TIANSHAN MOUNTAINS, CHINA%天山北麓活动背斜区河流阶地与古地震事件

    Institute of Scientific and Technical Information of China (English)

    杨晓平; 李安; 黄伟亮; 张玲

    2011-01-01

    Using the aerial remote sensing photos and Google earth satellite images,we find seven terraces at the both sides along the Kuytun River in Dushanzi active anticline area, northern piedmont of Tians-han. Based on the field investigation, we find that all these terraces are pedestal terraces. The rock of pedestal is Pliocene mud rock, and on the top of each terrace pedestal are the stratums of sandy gravel or sandy clay with 2. 5 ~ 15m in thickness. We collected samples from deposits of all terraces for OSL (optically stimulated luminescence) geological dating using the SMAR( single-multiple-aliquot-regeneration) method on fine grains. We also performed dating using the C method to the samples from the deposit of terrace T, of the Kuytun River. The results show that the ages of all these deposits are the later phase of the Late Pleistocene. The accumulation time of the upper stratum for T, , T2, T3 , T5 , T6and T7 terraces is about 1. 7ka, 14. 98ka,20. 7 ~ 27. 3ka,29. 3 ~ 39. 2ka,47 ~ 56ka and 103 ~ 118ka,respectively. Combining with late Quaternary climate change,we believe that the formation age forT1 ~T7 terraces of Kuytun River are 1. 7ka, 14ka,20ka,25ka, 30ka,50ka and lOOkaBP. Paleo-earthquake data reveal that eight paleoearthquake events occurred on the Dushanzi-Anjihai reverse fault since about 25ka BP, respectively at 2ka, 3. 4ka, 4. 3ka, 5. 8ka, 7. 5ka, 12. 8ka, 18ka and 24ka BP. Comparing the ages of paleoearthquakes and terraces,we find that the ages of the latest,the sixth, the seventh and the eighth paleoearthquake are roughly corresponding to the formation times of T1 , T2 ,T3and T4 terraces,respectively. The other four paleoearthquake events occurred during the period after the formation of T2and before the formation of T,. In this time,no terraces developed along the Kuytun River, but the Kuytun River incised rapidly for 40m. We believe that the paleoearthquake e-vents resulted in the fast uplift of Dushanzi active anticline on the hanging wall of

  7. 珠江口盆地惠州凹陷北部边界断裂复合联接和转换%Complex Linkage and Transformation of Boundary Faults of Northern Huizhou Sag in Pearl River Mouth Basin

    Institute of Scientific and Technical Information of China (English)

    田巍; 何敏; 杨亚娟; 刘海伦; 袁勋; 吴森; 朱定伟; 梅廉夫

    2015-01-01

    边界断裂控制断陷盆地的形成和构造格局,不同边界断裂联接模式对不同类型盆地演化具有差异性。基于井控高精度3D 地震资料,通过对边界断裂几何学特征描述和“四级小层”刻画,结合裂陷 I 幕边界断裂不同区段的活动差异性以及与沉积中心迁移的空间匹配关系,剖析珠江口盆地惠州凹陷北部边界断裂的形成和演化。惠州凹陷北部边界断裂始新世早期分段孤立发育,逐渐以纵向和横向双向联接的模式发展。纵向联接为断层软联接和硬联接复合联接和转换,形成转换斜坡和横向背斜,控制凹(洼)陷的结构与演化,制约沉积中心及层序的迁移。横向联接表现为转换斜坡内横向断层的多阶段联接,联接过程可划分为孤立正断层、同向叠置及硬联接3个阶段,控制转换斜坡带内沉积体系的发育和展布。研究给出了一个裂陷盆地边界断裂时空演化、复合联接和转换模式的独特案例,对丰富裂陷盆地边界断裂及其与沉积层序、凹陷演化和区域动力学机制的响应关系的研究具有积极的意义和价值。%The formation and tectonic framework of a faulted basin are controlled by boundary fault,which have different types of basin evolution under different boundary connection modes.The purpose of this study is to recognize the linkage model of boundary faults of northern Huizhou sag in Zhu I depression,Pearl River Mouth basin (PRMB),the South China Sea,which is a representative of global passive continental margin basins.Based on well controlling high-precision 3D seismic survey,the geometry of boundary faults and the framework of “four-order sequences”are determined in PRMB.The fault activities of dif-ferent boundary fault sections and the spatial change of depocenters during rift episode I are analyzed.An evolution model of boundary fault system in northern Huizhou sag,PRMB is established in this

  8. Knife River Indian Villages National Historic Site: Teacher's Guide.

    Science.gov (United States)

    National Park Service (Dept. of Interior), Washington, DC. National Register of Historic Places.

    This guide provides history and social studies teachers, at all grade levels, with information and activities about the American Indians of the Northern Plains who lived in the area of the Knife River where it enters the Missouri River. Located in what is now North Dakota, this area is the Knife River Indian Villages National Historic Site. The…

  9. River engineering

    NARCIS (Netherlands)

    De Vries, M.

    1993-01-01

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

  10. The Nile River

    Science.gov (United States)

    2002-01-01

    This image of the northern portion of the Nile River was captured by MISR's nadir camera on January 30, 2001 (Terra orbit 5956). The Nile is the longest river in the world, extending for about 6700 kilometers from its headwaters in the highlands of eastern Africa. At the apex of the fertile Nile River Delta is the Egyptian capital city of Cairo. To the west are the Great Pyramids of Giza. North of here the Nile branches into two distributaries, the Rosetta to the west and the Damietta to the east. Also visible in this image is the Suez Canal, a shipping waterway connecting Port Said on the Mediterranean Sea with the Gulf of Suez. The Gulf is an arm of the Red Sea, and is located on the righthand side of the picture. Image credit: NASA/GSFC/LaRC/JPL, MISR Team.

  11. Offshore baseline for the northern Alaska coastal region generated to calculate shoreline change rates along exposed coastlines between the U.S.-Canadian border and the Okpilak-Hulahula River Delta for the time period 1947 to 2003

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Arctic Coastal Plain of northern Alaska is an area of strategic economic importance to the United States, is home to remote Native American communities, and...

  12. Offshore baseline for the northern Alaska coastal region generated to calculate shoreline change rates along exposed coastlines between the Colville River Delta and Point Barrow for the time period 1947 to 2005

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Arctic Coastal Plain of northern Alaska is an area of strategic economic importance to the United States, is home to remote Native American communities, and...

  13. WestBeaufort_sheltered_baselines.shp - Offshore baseline for the northern Alaska coastal region generated to calculate shoreline change rates along sheltered coastlines between the Colville River Delta and Point Barrow for the time period 1947 to 2005

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Arctic Coastal Plain of northern Alaska is an area of strategic economic importance to the United States, is home to remote Native American communities, and...

  14. Offshore baseline for the northern Alaska coastal region generated to calculate shoreline change rates along exposed coastlines between the U.S.-Canadian border and the Okpilak-Hulahula River Delta for the time period 1947 to 2003

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Arctic Coastal Plain of northern Alaska is an area of strategic economic importance to the United States, is home to remote Native American communities, and...

  15. Offshore baseline for the northern Alaska coastal region generated to calculate shoreline change rates along exposed coastlines between the Colville River Delta and Point Barrow for the time period 1947 to 2005

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Arctic Coastal Plain of northern Alaska is an area of strategic economic importance to the United States, is home to remote Native American communities, and...

  16. Offshore baseline for the northern Alaska coastal region generated to calculate shoreline change rates along sheltered coastlines between the U.S.-Canadian border and the Okpilak-Hulahula River Delta for the time period 1947 to 2003

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Arctic Coastal Plain of northern Alaska is an area of strategic economic importance to the United States, is home to remote Native American communities, and...

  17. WestBeaufort_sheltered_baselines.shp - Offshore baseline for the northern Alaska coastal region generated to calculate shoreline change rates along sheltered coastlines between the Colville River Delta and Point Barrow for the time period 1947 to 2005

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Arctic Coastal Plain of northern Alaska is an area of strategic economic importance to the United States, is home to remote Native American communities, and...

  18. Offshore baseline for the northern Alaska coastal region generated to calculate shoreline change rates along sheltered coastlines between the U.S.-Canadian border and the Okpilak-Hulahula River Delta for the time period 1947 to 2003

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Arctic Coastal Plain of northern Alaska is an area of strategic economic importance to the United States, is home to remote Native American communities, and...

  19. Evaluation of groundwater-surface water interaction through groundwater modelling: simulation of the effects of removal of a dam along a river at a contaminated site in Northern France

    National Research Council Canada - National Science Library

    Remonti, Michele; Mori, Piero

    .... The scope of the work was the optimisation of the existing groundwater pump and treat system and the prediction of possible effects on groundwater circulation after the future removal of a dam located along the river...

  20. Historical Resources Evaluation, St. Paul District Locks and Dams on the Mississippi River and Two Structures at St. Anthony Falls; Locks and Dams in Minnesota, Wisconsin and Northern Iowa.

    Science.gov (United States)

    1983-09-01

    Iowa with brief consideration of the Mississippi River as an important trans- portation artery. Havighurst, Walter. Upper Mississippi, A Wilderness Saga ...forces and public works until completion in the twilight of the New Deal. Like riverboat traffic, the improvement of the upper Mississippi River can be...navigation to Minneapolis, ironically at the twilight of the steamboat era. (Fullerton 1906: 497; Kane 1966: 175) The two structures were to be built

  1. 基于标准水资源指数(SWRI)的流域水文干旱评估--以海河北系为例%Hydrological drought assessment in the river basin based on Standard Water Resources Index (SWRI):a case study on the Northern Haihe River

    Institute of Scientific and Technical Information of China (English)

    翟家齐; 蒋桂芹; 裴源生; 赵勇; 肖伟华

    2015-01-01

    构建了一个新的水文干旱评估指标——标准水资源指数(SWRI),结合分布式水循环模型、Copula函数及统计检验等方法,形成了一套完整的水文干旱识别、评估及特征分析的基本框架。以海河北系为例,定量识别了1956—2009年间的水文干旱事件,并对其干旱特征及变化规律进行了剖析。结果表明:海河北系近54年发生的34次水文干旱主要集中在短历时、低强度、小面积区间内,空间上主要分布在张家口、大同及北京等地区;干旱指标的联动关系上,干旱历时、强度与面积指标间呈显著的线性或指数相关关系,90%的水文干旱历时低于40个月、干旱面积占比不超过43%,干旱强度低于9.0;在给定的干旱特征指标值(如干旱面积)条件下,另一干旱指标值越大(如强度越大)干旱发生概率越小,且存在明显的特征区间;单变量水文干旱重现期介于联合重现期和同现重现期之间。%In this study,a new hydrological drought assessment index named Standard Water Resources In⁃dex (SWRI) was established. Based on the SWRI,and a basic framework of hydrological drought identifica⁃tion, assessment and characteristic analysis was developed by combining the distributed hydrological model, Copula functions and statistical test methods. Taking the Northern Haihe River as a case, the hydrological drought events between 1956 and 2009 were identified quantitatively,and the hydrological drought character⁃istics as well as the changing rules were analyzed. The results show that 34 hydrological drought events dur⁃ing the past 54 years all happened within small areas and lasted for a short time period with low intensity. Spatially,they concentrated mainly in Zhangjiakou City,Datong City and Beijing Municipality in the North⁃ern Haihe River Basin. In terms of the drought index relationship, there is a strong linear or exponential relationship

  2. Development of a Systemwide Predator Control Program, Section II : Northern Squawfish Management Program Evaluation, 1995 annual report.

    Energy Technology Data Exchange (ETDEWEB)

    Young, Franklin R. (Columbia Basin Fish and Wildlife Authority, Portland, OR)

    1997-04-01

    Report on progress on evaluation of the Columbia River Northern Squawfish Management Program in 1995. The objectives in 1995 were to (1) evaluate exploitation rate and size composition of northern squawfish captured in various fisheries, and estimate reductions in predation on juvenile salmonids since implementation of the Northern Squawfish Management Program; and (2) evaluate changes through 1995 in relative abundance, consumption, size and age structure, growth, and fecundity of northern squawfish in lower Columbia and Snake River reservoirs and in the Columbia River downstream from Bonneville Dam.

  3. Contested Rivers

    DEFF Research Database (Denmark)

    Gorm Hansen, Louise Lyngfeldt

    explores translocal connections through ethnographic fieldwork at a global water conference and preliminary fieldwork at chosen locations on China's Nu River. The Nu River is one of the last undammed rivers in Asia and runs through China close to the Chinese-Burmese border, then flows into the Andaman Sea...

  4. I-131 originating from nuclear medicine in German rivers; Nuklearmedizinisches {sup 131}I in deutschen Fluessen

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Helmut W. [Bremen Univ. (Germany). Fachbereich 1 - Physik; Strobl, Christopher [Bundesamt fuer Strahlenschutz, Oberschleissheim (Germany). Dienststelle Muenchen; Gellermann, Rainer

    2014-04-01

    The OSPAR agreement obligates the German government to determine and report the annual I-131 insertion from German rivers into the Northern Atlantic Ocean. In the frame of a research program the I-131 concentrations were determined in the rivers Elbe, Weser, Ems and Rhein that allowed the evaluation of the contamination load into the Northern Sea using a balance model.

  5. Sediment load reduction in Chinese rivers

    Institute of Scientific and Technical Information of China (English)

    Cheng LIU; Jueyi SUI; Zhao-Yin WANG

    2008-01-01

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

  6. A vast medieval dam-lake cascade in northern central Europe: review and new data on late Holocene water-level dynamics of the Havel River, Berlin-Brandenburg area (Germany)

    Science.gov (United States)

    Kaiser, Knut; Keller, Nora; Brande, Arthur; Dalitz, Stefan; Hensel, Nicola; Heußner, Karl-Uwe; Kappler, Christoph; Michas, Uwe; Müller, Joachim; Schwalbe, Grit; Weiße, Roland; Bens, Oliver

    2016-04-01

    An interdisciplinary study was carried out in order to trace the human transformation of the medium-scale Havel River in northeastern central Europe during the last c. 2000 years. This research was driven by the hypothesis that the present-day riverscape is widely a legacy of medieval and modern human transformation of the drainage system initiated essentially by damming for the operation of water mills. Recent opportunities to investigate the extent of this human impact arose during the course of archaeological rescue excavations and palaeoecologic studies, which significantly enhanced the amount of respective high-quality data. Along the middle course of the Havel, sedimentary sequences were analysed in order to explore the potential for reconstructing regional water-level dynamics. The river, draining the Berlin metropolitan area, forms a chain of dammed lakes and meandering river sections which were strongly modified by hydraulic engineering in the past. We have not only recorded new sections but also re-evaluated older ones, forming a total of sixteen sedimentary sequences along the river. Chronological control is provided by a multitude of palynological, dendrochronological, archaeological, and radiocarbon data. The sections upriver from the Brandenburg/H. and Spandau weirs, representing sites with historic water mills, reveal substantial water-level changes during the late Holocene. Generally, lower water levels before and higher levels parallel to the medieval German colonisation of that area (c. 1180/1250 AD) can be inferred. This water-level increase, which is attributed to be caused by medieval mill stowage, took place rapidly and amounted to a relative height of c. 1.5 m. It has caused the widening of river sections and the enlargement of existing lakes or its secondary formation when already aggraded, and thus a flooding of large portions of land. The rising water level has even influenced the settlement topography to a large degree. Several medieval

  7. River discharge changes in the Qinghai-Tibet Plateau

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Annual mean discharge data of the five large rivers in the exorheic region of the Qinghai-Tibet Plateau from 1956 to 2000 are analyzed for trends with the Mann-Kendall nonparametric trend test. The results reveal that though in general no increasing trends exist in the total river discharges, significant regional differences of river discharge exist, reflecting the decreasing trends of discharge in the Yellow River and the Tongtian River (upper Changjiang River), an increasing trend in Yalong River, and inverted change in the Lancang River and Yarlung Zangbo River. Based on analyses of the seasonal discharge, it is found that climatic change had a significant effect on the seasonal variation of river discharge in the Qinghai-Tibet Plateau. In spring (from March to May) the discharge increased significantly, especially in the source area of the Yellow River. Together with the analyses on data of the mean temperature in the Northern Hemisphere and climatic data within the river basins, the relationship between discharges and mean temperature of the Northern Hemisphere is explored, which indicates that there is no increase in the stream discharge in the Qinghai-Tibet Plateau with global warming. It is probably the increasing evaporation, caused by rising temperature that offsets the hydrological effect of increasing precipitation.

  8. 27 CFR 9.47 - Hudson River Region.

    Science.gov (United States)

    2010-04-01

    ... to the New York-Pennsylvania state line in the Delaware River. (11) The boundary proceeds easterly along the Delaware River to the New York-New Jersey state line. (12) The boundary proceeds easterly... proceeds easterly along the northern side of Interstate Route 287 to the junction with N.Y. Route 15....

  9. River nomads

    DEFF Research Database (Denmark)

    2016-01-01

    River nomads is a movie about people on the move. The documentary film explores the lifestyle of a group of nomadic fishermen whose mobility has been the recipe of success and troubles. Engaged in trade and travel, twice a year the river nomads form impressive convoys of majestic pirogues and set...... and liberated lifestyle and the breath-taking landscapes and vistas offered by the Niger River. River Nomads is also a personal account of the Kebbawa’s way of life and their current struggles as nomadic folk living in a world divided by borders and ruled by bureaucrats....

  10. Factors favouring large organic production in the northern Adriatic: towards the northern Adriatic empirical ecological model

    Directory of Open Access Journals (Sweden)

    R. Kraus

    2015-06-01

    Full Text Available Influenced by one of the largest Mediterranean rivers, Po, the northern Adriatic production is highly variable seasonally and interannually. The changes are especially pronounced between winters and seemingly reflect on total Adriatic bioproduction of certain species (anchovy. We analysed the long-term changes in the phytoplankton production at the transect in the region, as derived from monthly oceanographic cruises, in relation to concomitant geostrophic currents distribution in the area and in the Po River discharge rates in days preceding the cruises. In winter and early spring the phyto-abundances depended on existing circulation fields, in summer and autumn they were related to 1–15 days earlier Po River discharge rates and on concomitant circulation fields, while in late spring phyto-abundances increased 1–3 days after high Po River discharge rates regardless of circulation fields. During the entire year the phyto-abundances were dependant on forcing of the previous 1–12 months of surface fluxes and/or Po River rates. Large February blooms are, as well as February circulation patterns, precondited by low evaporation rates in previous November. From 1990 to 2004 a shift towards large winter bioproduction induced by circulation changes appeared. Performed investigations represent the preliminary actions in building of an empirical ecological model of the northern Adriatic which can be used in the sustainable economy of the region, however also in validation of the numerical ecological model of the region, which is currently being developed.

  11. Factors favouring large organic production in the northern Adriatic: towards the northern Adriatic empirical ecological model

    Science.gov (United States)

    Kraus, R.; Supić, N.; Precali, R.

    2015-06-01

    Influenced by one of the largest Mediterranean rivers, Po, the northern Adriatic production is highly variable seasonally and interannually. The changes are especially pronounced between winters and seemingly reflect on total Adriatic bioproduction of certain species (anchovy). We analysed the long-term changes in the phytoplankton production at the transect in the region, as derived from monthly oceanographic cruises, in relation to concomitant geostrophic currents distribution in the area and in the Po River discharge rates in days preceding the cruises. In winter and early spring the phyto-abundances depended on existing circulation fields, in summer and autumn they were related to 1-15 days earlier Po River discharge rates and on concomitant circulation fields, while in late spring phyto-abundances increased 1-3 days after high Po River discharge rates regardless of circulation fields. During the entire year the phyto-abundances were dependant on forcing of the previous 1-12 months of surface fluxes and/or Po River rates. Large February blooms are, as well as February circulation patterns, precondited by low evaporation rates in previous November. From 1990 to 2004 a shift towards large winter bioproduction induced by circulation changes appeared. Performed investigations represent the preliminary actions in building of an empirical ecological model of the northern Adriatic which can be used in the sustainable economy of the region, however also in validation of the numerical ecological model of the region, which is currently being developed.

  12. MACROSCOPIC RIVERS

    NARCIS (Netherlands)

    VANDENBERG, IP

    1991-01-01

    We present a mathematical model for the ''river-phenomenon'': striking concentrations of trajectories of ordinary differential equations. This model of ''macroscopic rivers'' is formulated within nonstandard analysis, and stated in terms of macroscopes and singular perturbations. For a subclass, the

  13. Exploration potential of offshore northern California basins

    Energy Technology Data Exchange (ETDEWEB)

    Bachman, S.B.; Crouch, J.K.

    1988-01-01

    A series of exploratory wells was drilled in the northern California offshore basins in the 1960s following leasing of federal tracts off northern California, Oregon, and Washington. The drilling, although encountering numerous oil shows, was considered at the time to indicate low prospectivity in an area that extended as far south as the offshore Santa Maria basin. However, subsequent major discoveries in this decade in the offshore Santa Maria basin, such as the Point Arguello field, indicate that these offshore basins may be highly prospective exploration targets. Many of the key features of Monterey production in central and southern California are also present in the offshore basins of northern California. A new 5-year leasing plan has scheduled leasing in the northern California OCS starting in early 1989. The first basins on the schedule, the Point Arena and Eel River basins, differ in some respects. The Point Arena basin is more typical of a Monterey basin, with the potential for fractured chert reservoirs and organic-rich sections, deep burial of basinal sections to enhance the generation of higher gravity oils, and complex folding and faulting. The Eel River basin is more clastic-rich in its gas-producing, onshore extension. Key questions in the Eel River basin include whether the offshore, more distal stratigraphy will include Monterey-like biogenic sediments, and whether the basin has oil potential in addition to its proven gas potential. The Outer Santa Cruz basin shares a similar stratigraphy, structure, and hydrocarbon potential with the Point Arena basin. The Santa Cruz-Bodega basin, also with a similar stratigraphy, may have less exploration potential because erosion has thinned the Monterey section in parts of the basin.

  14. Flooding on Elbe River

    Science.gov (United States)

    2002-01-01

    Heavy rains in Central Europe over the past few weeks have led to some of the worst flooding the region has witnessed in more than a century. The floods have killed more than 100 people in Germany, Russia, Austria, Hungary, and the Czech Republic and have led to as much as $20 billion in damage. This false-color image of the Elbe River and its tributaries was taken on August 20, 2002, by the Moderate Resolution Imaging Spectroradiometer (MODIS), flying aboard NASA's Terra satellite. The floodwaters that inundated Dresden, Germany, earlier this week have moved north. As can be seen, the river resembles a fairly large lake in the center of the image just south of the town of Wittenberg. Flooding was also bad further downriver in the towns of Maqgdeburge and Hitzacker. Roughly 20,000 people were evacuated from their homes in northern Germany. Fifty thousand troops, border police, and technical assistance workers were called in to combat the floods along with 100,000 volunteers. The floodwaters are not expected to badly affect Hamburg, which sits on the mouth of the river on the North Sea. Credit:Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

  15. Distribution and Habitat Use of Swainson's Warblers in Eastern and Northern Arkansas

    Science.gov (United States)

    James C. Bednarz; Petra Stiller-Krehel; Brian Cannon

    2005-01-01

    Systematic surveys of hardwood forests along the Buffalo National River, the St. Francis Sunken Lands Wildlife Management Area, St. Francis National Forest, Bayou Meto Wildlife Management Area, and the White River National Wildlife Refuge in eastern and northern Arkansas were undertaken between 5 April and 30 June 2000 and 2001 to document current status, distribution...

  16. Modelling Peatland Hydrology: Three cases from Northern Europe

    NARCIS (Netherlands)

    Querner, E.P.; Mioduszewski, W.; Povilaitis, A.; Slesicka, A.

    2010-01-01

    Many of the peatlands that used to extend over large parts of Northern Europe have been reclaimed for agriculture. Human influence continues to have a major impact on the hydrology of those that remain, affecting river flow and groundwater levels. In order to understand this hydrology it is necessar

  17. Culturally and economically important nontimber forest products of northern Maine

    Science.gov (United States)

    Michelle J. Baumflek; Marla R. Emery; Clare. Ginger

    2010-01-01

    Nontimber forest products (NTFPs) gathered for food, medicine, craft, spiritual, aesthetic, and utilitarian purposes make substantial contributions to the economic viability and cultural vitality of communities. In the St. John River watershed of northern Maine, people identifying with cultural groups including Acadian, Maliseet, Mi'kmaq, Scotch-Irish, and Swedish...

  18. Comparative Mountain Hydrology: A Case Study of Wis(l)ok River in Poland and Chaohe River in China

    Institute of Scientific and Technical Information of China (English)

    Leszek SOBKOWIAK; LIU Changming

    2015-01-01

    Hydrological processes in river basins of similar size and morphology may differ significantly due to different climatic conditions.This paper presents a comparative analysis of hydrological characteristics of two river basins located in different climatic zones:the Wis(l)ok River Basin in the south-eastern Poland and the Chaohe River Basin in the northern China.The criteria of their choice were similarities in the basin area,main river length and topography.The results show that climate plays a key role in shaping fluvial conditions within the two basins.It is concluded that:1) precipitation in the Wis(l)ok River Basin is more evenly distributed in the yearly cycle,while in the Chaohe River Basin it is highly concentrated in the few summer months; 2) spring snowmelt significantly contributes to runoff in the Wis(l)ok River Basin,while its role in the Chaohe River Basin is negligible; 3) in the Wis(l)ok River Basin,besides the peak flow in spring,there is also a period of high water in summer resulting from precipitation,while in the Chaohe River Basin there is only one high water period in summer; 4) the Wis(l)ok River Basin shows relatively higher stability in terms of the magnitude of intra-and inter-seasonal discharges; 5) during the multi-year observation period,a decrease in both precipitation and runoff was recorded in the two river basins.

  19. Fertilization of Northern Hardwoods

    Science.gov (United States)

    R. Lea; D.G. Brockway

    1986-01-01

    Northern hardwoods grow over a considerable range of climatic and edaphic conditions and exhibit a wide range in productivity.Many northern hardwood forests are capable of high production relative to other forest types, but are often slow to reach maximum productivity because of low nutrient availability.Altering the patterns of biomass accumulation so that managers...

  20. THE HOLOCENE FLORA AND VEGETATION OF THE NORTHERN RUSSIAN PLAIN (THE VYCHEGDA RIVER BASIN)%俄罗斯北部平原(VYCHEGDA河盆地)全新世植物群和植被

    Institute of Scientific and Technical Information of China (English)

    O.K.Borisova

    2002-01-01

    A section of floodplain deposits of the Vychegda River near the Baika village (61°16'N, 46°44'E) was studiedpalynologically. The site is located in the middle taiga zone, near the boundary of the European spruce forest and sub-Urals-Siberian spruce-fur-Siberian pine forest. The river basin is densely forested (up to 98%). According to the radiocarbon dating,the sedimentation took place during the major part of the Holocene, since app. 9000 yrs B.P.Reconstruction of the vegetation and climatic changes in the region during the Holocene is based on the composition offossil floras (Grichuk, 1969). Geographical analysis of modem spatial distribution of all the plant taxa of certain fossil floraallows to locate the closest modern floristic analogue to the past vegetation. By identifying the region where all the species ofplants grow at the present time it is possible to determine the closest modem landscape and climatic analogue to the pastenvironment under consideration. The present-day features of plant communities and main climatic indices of such a region-analogue should be close to if not identical with those existed at the site in the past.Pollen assemblages were dominated by spruce, pine and birch pollen through the whole sediment sequence, but neverthe-less substantial changes took place both in the composition of flora and vegetation. Participation of the warm-temperatedeciduous trees (linden, elm, and oak) in the forest communities varied through time and reached its maximum in the warmestinterval of the Holocene, correspondent to the middle and late Atlantic (6000-4500 yrs B.P.). These changes are reflected by"migration" of modern floristic analogue regions over the Russian Plain beginning from the Middle and Southern Urals as farwest as the Sukhona River Basin, and back to the site under study at the downstream end of the Vychegda River. Quantitativereconstructions of the main climatic indexes, based on the paleofloristic method, show that in the Atlantic

  1. Concentrations and sources of polycyclic aromatic hydrocarbons in surface coastal sediments of the northern Gulf of Mexico

    National Research Council Canada - National Science Library

    Zucheng Wang; Zhanfei Liu; Kehui Xu; Lawrence M Mayer; Zulin Zhang; Alexander S Kolker; Wei Wu

    2014-01-01

    ...) of the northern Gulf of Mexico. Results PAH concentrations in this region ranged from 100 to 856 ng g-1, with the highest concentrations in Mississippi River mouth sediments followed by marsh sediments and then the...

  2. Field intercomparison of channel master ADCP with RiverSonde Radar for measuring river discharge

    Science.gov (United States)

    Spain, P.; Marsden, R.; Barrick, D.; Teague, C.; Ruhl, C.

    2005-01-01

    The RiverSonde radar makes non-contact measurement of a horizontal swath of surface velocity across a river section. This radar, which has worked successfully at several rivers in the Western USA, has shown encouraging correlation with simultaneous measurements of average currents at one level recorded by an acoustic travel-time system. This work reports a field study intercomparing data sets from a 600 kHz Channel Master ADCP with the RiverSonde radar. The primary goal was to begin to explore the robustness of the radar data as a reliable index of discharge. This site Is at Three Mile Slough in Northern California, USA. The larger intent of the work is to examine variability in space and time of the radar's surface currents compared with subsurface flows across the river section. Here we examine data from a couple of periods with strong winds. ?? 2005 IEEE.

  3. A contrast of two typical LUCC processes and their driving forces in oases of arid areas: A case study of Sangong River Watershed at the northern foot of Tianshan Mountains

    Institute of Scientific and Technical Information of China (English)

    TANG FaShu; CHEN Xi; LUO GePing; LIN Qing; LIU HaiLong

    2007-01-01

    Aerial photographs taken in 1978 and 1987, Landsat TM images in 1998 as well as soil, hydrology and socio-economic data for the oases in Sangong River Watershed were processed by Remote Sensing (RS) and Geographic Information System (GIS). There are two typical agricultural land uses in oases,Farm-based Land Use with large-scale intensified agricultural activities (FLU) and Household Responsibility-based Land Use with small-scale activities (HRLU). The Index Model of Land Use/Land Cover Change (LUCC), Weighted Index Sum (WIS) and logistic stepwise regression model were established to contrast the two typical LUCC processes and their driving forces. The land use patterns were dominated by cropland and grassland for the entire region, and cropland, residential and industrial land were increasing stably. In the HRLU areas, woodland and grassland declined dramatically, but in the FLU areas, grassland decreased only by 12.0%, whereas woodland increased by 13.7%. LUCC was stronger in the earlier stage (1978-1987) than in the later stage (1987-1998) for the entire region. LUCC was more intense in the HRLU areas than in the FLU areas during the entire period (1978-1998). Policy was a key factor in the land use change, and water resources were a precondition in land use. Under the control of policy and water resources,the main human driving factors included population and economy, and the main natural restrictions were soil fertility and groundwater depth. Human driving factors controlled the land change in the HRLU areas, but natural restriction factors dominated in the FLU areas. In the mean time,intensification of LUCC in the region had some spatiotemporal implications with a fluctuation of impact factors.

  4. The effects of Thailand's Great Flood of 2011 on river sediment discharge in the upper Chao Phraya River basin, Thailand

    Institute of Scientific and Technical Information of China (English)

    Butsawan Bidorn; Seree Chanyotha; Stephen A. Kish; Joseph F. Donoghue; Komkrit Bidorn; Ruetaitip Mama

    2015-01-01

    Severe flooding that occurred during the 2011 monsoon season in Thailand was the heaviest flooding in the past 50 yr. The rainfall over the northern part of Thailand, especially during July–August 2011, was 150% higher than average. During the flooding period, river flows of the four major Chao Phraya River tributaries (Ping, Wang, Yom, and Nan rivers) increased in the range of 1.4–5 times the average discharge. This study examined the river sediment discharge of the four major rivers in the upper Chao Phraya River basin in Thailand. The four rivers are considered the main sources of sediment supply to the Chao Phraya Estuary. River surveys of the Ping, Wang, Yom, and Nan rivers were carried out in October 2011 (during the Great Flood) and October 2012 (one year after the flood). Survey data included river cross sections, flow velocities, suspended sediment concentrations, and bed load transport in each river. Analyses of these data indicated that total sediment transport rates for the four main rivers during the flooding of 2011 were 2.3–5.6 times higher than the average sediment discharge over 60 yr. The flood of 2011 sig-nificantly affected the sediment characteristics including the proportions of suspended and bed sediment loads in each river though in different ways. The rates of sediment transport per unit discharge for the Ping and Wang rivers dramatically increased during the 2011 flood, but the flooding had minimal effects on the sediment characteristics in the Yom and Nan rivers. The amount of total sediment discharge in each river caused by the 2011 flooding varied between 0.3 and 1.6 Mt. Additionally, the bed load transport in these rivers varied between ? 0%and 26%of the suspended sediment discharge.

  5. Quantifying the extent of river fragmentation by hydropower dams in the Sarapiquí River Basin, Costa Rica

    Science.gov (United States)

    Anderson, Elizabeth P.; Pringle, Catherine M.; Freeman, Mary C.

    2008-01-01

    Costa Rica has recently experienced a rapid proliferation of dams for hydropower on rivers draining its northern Caribbean slope. In the Sarapiquí River Basin, eight hydropower plants were built between 1990 and 1999 and more projects are either under construction or proposed. The majority of these dams are small (hydropower development. This study was a first attempt to quantify the extent of river fragmentation by dams in the Sarapiquí River Basin.Using simple spatial analyses, the length of river upstream from dams and the length of de-watered reaches downstream from dams was measured. Results indicated that there are currently 306.8 km of river (9.4% of the network) upstream from eight existing dams in the Sarapiquí River Basin and 30.6 km of rivers (0.9% of the network) with significantly reduced flow downstream from dams. Rivers upstream from dams primarily drain two life zones: Premontane Rain Forest (107.9 km) and Lower Montane Rain Forest (168.2 km).Simple spatial analyses can be used as a predictive or planning tool for considering the effects of future dams in a basin-scale context. In the Sarapiquí River Basin, we recommend that future dam projects be constructed on already dammed rivers to minimize additional river fragmentation and to protect remaining riverine connectivity.

  6. Northern Dimension: Participant Strategies

    Directory of Open Access Journals (Sweden)

    Busygina Irina

    2009-03-01

    Full Text Available This article is devoted to the “Northern Dimension” initiative of the EU which also includes North-West Russia, Norway and Iceland. It is noted that the “Northern Dimension” in the theoretical perspective can be considered as part of strategic multi-level interactions between member-states of the EU and Russia. On this basis, the authors analyze implications and effects of the strategic interdependence of all the EU-Russia relation levels.

  7. Phytosociological survey of weeds in banana plantations in the Gorutuba River Valley, northern Minas Gerais = Levantamento fitossociológico de plantas daninhas em áreas de bananicultura no Vale do Rio Gorutuba, norte de Minas Gerais

    Directory of Open Access Journals (Sweden)

    Hercules Gustavo dos Santos Sarmento

    2015-10-01

    Full Text Available Phytosociological surveys are very important when identifying an invasive community in order to carry out more suitable weed management. The aim of this study therefore, was to identify the main species of weeds in banana plantations, both newly-planted and under production, in the northern region of the State of Minas Gerais, Brazil. For the phytosociological study and characterisation of the weed community, two areas of ‘Prata’ bananas, both of 10 hectares, were evaluated using the method of inventory squares, which were randomly thrown along a zigzag path. The following phytosociological variables were evaluated: frequency, relative frequency, density, relative density, abundance, relative abundance, importance value index, relativeimportance value index and similarity index. In the newly-planted area, 17 species were found, divided into 15 genera and ten families, with the Fabaceae and Poaceae families being prominent. The species with the highest importance indices were: Sida spp. (62.38, Galinsoga parviflora (32.36, Amaranthus hybridus (24.93 and Ipomoea hederifolia (19.61. In the area under production, 12 species, 12 genera and ten families were found, with the Asteraceae family being prominent. The species with the highest relative-importance value indices were: Commelina benghalensis (39.19, Emilia fosbergii (34.42 and Amaranthus hybridus (32.96. Between the two areas, there was a difference in the mean values for density, and for the number of plants with C4 metabolism; five in the newly-planted area, and three in the area under production. The Similarity Index between the two areas was 48.27%, with seven species common to both areas. = O levantamento fitossociológico é muito importante para conhecer a comunidade infestante e, com isso, realizar de forma mais adequada o manejo das plantas daninhas. Objetiva-se com este trabalho identificar as principais espécies de plantas daninhas em áreas de bananicultura recém-implantadas e

  8. Northern Prairie Wildlife Research Center

    Science.gov (United States)

    ,

    2009-01-01

    The Northern Prairie Wildlife Research Center (NPWRC) conducts integrated research to fulfill the Department of the Interior's responsibilities to the Nation's natural resources. Located on 600 acres along the James River Valley near Jamestown, North Dakota, the NPWRC develops and disseminates scientific information needed to understand, conserve, and wisely manage the Nation's biological resources. Research emphasis is primarily on midcontinental plant and animal species and ecosystems of the United States. During the center's 40-year history, its scientists have earned an international reputation for leadership and expertise on the biology of waterfowl and grassland birds, wetland ecology and classification, mammalian behavior and ecology, grassland ecosystems, and application of statistics and geographic information systems. To address current science challenges, NPWRC scientists collaborate with researchers from other U.S. Geological Survey centers and disciplines (Biology, Geography, Geology, and Water) and with biologists and managers in the Department of the Interior (DOI), other Federal agencies, State agencies, universities, and nongovernmental organizations. Expanding upon its scientific expertise and leadership, the NPWRC is moving in new directions, including invasive plant species, restoration of native habitats, carbon sequestration and marketing, and ungulate management on DOI lands.

  9. 天山北坡玛纳斯河流域晚冰期以来植被垂直带推移%Shifting of vertical vegetation zones in Manas River drainage on northern slope of Tianshan Mountains since the Late Glacier

    Institute of Scientific and Technical Information of China (English)

    纪中奎; 刘鸿雁

    2009-01-01

    The statistical relationships between climate indexes(moisture index and warmth index)and typical pollen taxa were established with linear regression method on the Manas River drainage on the northern slope of the Tianshan Mountains.Climate and vegetation developments in this region were reconstructed based on the different pollen taxa content of a previously published sediment sequence from the Manas Lake, a desiccated end lake of the Manas River, as well as modern climate, vegetation and landform relationships.Since 13000 a BP, the palaeoclimate change in this area has experienced several important stages: warm-dry, cold-moist, warm-dry, cold-moist, warm-dry, cold-moist and warm-dry, in correspondance with the climate change, ancient vertical vegetation change around the area has experienced a series of succession processes: desert, desert steppe(to develop lowland meadow and stepped locally), extreme arid desert, desert steppe, desert, desert steppe, desert.When the climate in the Manas River drainage changed from warm-dry to cold-moist, all vegetation boundaries in the area moved downward, hence the area of desert and forest was enlarged and the lower limit of conifer may get to current steppe.When the palaeoclimate changed from cold-moist to warm-dry, all vegetation boundaries moved upward, the area of desert was enlarged, while the area of steppe and forest was decreased, and the lower limit of conifer may get to current alpine and sub alpine meadow.%建立了反映天山北坡玛纳斯河流域典型花粉类型与气候指标(湿润指数和温暖指数)的统计函数.基于前人研究得出的玛纳斯湖沉积剖面中不同花粉的百分含量复原了晚冰期以来玛纳斯河流域古气候的变化,并基于山地植被-气候-地形关系推断了玛纳斯河流域的植被演变过程.研究结果表明:该区晚冰期以来经历了暖干-冷湿-暖干-偏冷偏湿-暖干-冷湿-暖干的气候变化过程,植被垂直带基带相应为荒漠-

  10. Diazotrophy in alluvial meadows of subarctic river systems.

    Directory of Open Access Journals (Sweden)

    Thomas H DeLuca

    Full Text Available There is currently limited understanding of the contribution of biological N2 fixation (diazotrophy to the N budget of large river systems. This natural source of N in boreal river systems may partially explain the sustained productivity of river floodplains in Northern Europe where winter fodder was harvested for centuries without fertilizer amendments. In much of the world, anthropogenic pollution and river regulation have nearly eliminated opportunities to study natural processes that shaped early nutrient dynamics of large river systems; however, pristine conditions in northern Fennoscandia allow for the retrospective evaluation of key biochemical processes of historical significance. We investigated biological N2 fixation (diazotrophy as a potential source of nitrogen fertility at 71 independent floodplain sites along 10 rivers and conducted seasonal and intensive analyses at a subset of these sites. Biological N2 fixation occurred in all floodplains, averaged 24.5 kg N ha(-1 yr(-1 and was down regulated from over 60 kg N ha(-1 yr(-1 to 0 kg N ha(-1 yr(-1 by river N pollution. A diversity of N2-fixing cyanobacteria was found to colonize surface detritus in the floodplains. The data provide evidence for N2 fixation to be a fundamental source of new N that may have sustained fertility at alluvial sites along subarctic rivers. Such data may have implications for the interpretation of ancient agricultural development and the design of contemporary low-input agroecosystems.

  11. 北非地区海-陆热力差异与夏季江淮流域旱涝的关系%Relationships between the anomalies of sea-land thermal contrast in the northern Africa areas and the flood and drought in the Changjiang and Huaihe river areas in summer.

    Institute of Scientific and Technical Information of China (English)

    赵勇; 钱永甫

    2008-01-01

    基于NCEP/NCAR月均再分析资料和中国743站降水资料,根据夏季江淮流域51 a(1954-2004年)区域旱涝指数的年代际变化特征,确定北非地区作为研究的关键区.分析发现,关键区的地表温度异常在冬季具有较好的持续性,冬季北大西洋涛动是导致这种异常持续性的重要原因之一.通过对前冬北非地区地表温度和夏季江淮流域降水的SVD分析发现:当北非大陆地区偏冷,其西北侧的海区偏暖时,江淮流域夏季的降水将整体偏多;反之,江淮流域夏季的降水整体偏少.进一步研究发现,北非地区海陆地表温度异常的对比,要比其中单一海洋或陆地区域的异常对夏季江淮流域的旱涝有更好的指示能力.文中定义了一个海陆热力差异指数来表征这种地表温度异常的对比程度,该指数和夏季江淮流域旱涝指数呈较好的正相关关系,并且对夏季江淮流域极端旱涝年份也有较好的指示,认为该指数可以作为一个指示江淮流域整体旱涝事件的预报因子.%The flood and drought in Changjiang and Huaihe river (Jianghuai) areas are frequent in summer, especially in July and June, so forecasting the summer flood and drought in Jianghuai areas is always one of key points investigated by meteorologists in China. The previous studies more focused on the skin temperature anomalies in a single area, and paid less attention to the connections between the anomalies of sea-land thermal contrast in northern Africa areas and the flood and drought in Jianghuai areas in summer. In this paper, we investigate such relationships and obtain some preliminary results.By use of the NCEP/NCAR monthly mean re-analysis data and the rainfall data at 743 stations in China, the Northern Africa areas are selected as the key regions according to the interdecadal variability characteristics of the flood and drought index (FDI) during 51 years(1954-2004) in Jianghuai areas in summer. Correlation

  12. Watershed Fact Sheet: Improving Utah's Water Quality, Little Bear River Watershed

    OpenAIRE

    2014-01-01

    The Little Bear River drains 185,000 acres at the southern end of Cache Valley in northern Utah. The river has two main forks that travel through relatively narrow and steep valleys, meeting at the approximate midpoint of the watershed near the town of Paradise.

  13. Cross currents : hydroelectricity and the engineering of northern Ontario

    Energy Technology Data Exchange (ETDEWEB)

    Manore, J.L. [Calgary Univ., AB (Canada)

    1999-05-01

    The history of hydroelectric development in northern Ontario was reviewed and analysed with special emphasis on the developments along the Mattagami and Abitibi Rivers. The objective was to examine the important factors that shaped modern hydroelectric development in Canada. System builders, the privately owned Nesbitt Thomson Company, the publicly owned Hydro Electric Power Corporation of Ontario and the eventual evolution of the single power system under Ontario Hydro are chronicled. Broad historical themes such as the technological impacts, regionalism, indigenous rights, plus environmental and economic issues are examined, in addition to an appreciation of the importance of electricity in the manufacturing sector of Ontario, the impact of hydroelectric development on the northern environment and on the northern First Nations, who rely on rivers for their subsistence. Until fairly recently, government policies and interpretations of law often excluded the recognition of Aboriginal uses of river systems, thereby limiting First Nations` peoples ability to practice traditional ways of life. In essence, the book is an account of how the northeastern power system in Ontario shaped the social, political and natural environments and how the development of northeastern power sources by southern power developers shaped the regional interactions between Ontario`s north and south. refs., figs.

  14. Quasiresonant amplification of planetary waves and recent Northern Hemisphere weather extremes

    OpenAIRE

    Petoukhov, Vladimir; Rahmstorf, Stefan; Petri, Stefan; Schellnhuber, Hans Joachim

    2013-01-01

    In recent years, the Northern Hemisphere has suffered several devastating regional summer weather extremes, such as the European heat wave in 2003, the Russian heat wave and the Indus river flood in Pakistan in 2010, and the heat wave in the United States in 2011. Here, we propose a common mechanism for the generation of persistent longitudinal planetary-scale high-amplitude patterns of the atmospheric circulation in the Northern Hemisphere midlatitudes. Those patterns—with zonal wave numbers...

  15. insurgents in Northern Uganda

    African Journals Online (AJOL)

    and the rebel movements in northern Uganda, see Human Rights Watch 2003, and ... of Uganda enacted an Amnesty Act in 2000, and to date more than ten thousand ..... Amnesty Certificate, and then in theory, a package.20 In the case of former .... [H]uman rights obligations are contracted on an international level.

  16. Northern blotting analysis

    DEFF Research Database (Denmark)

    Josefsen, Knud; Nielsen, Henrik

    2011-01-01

    Northern blotting analysis is a classical method for analysis of the size and steady-state level of a specific RNA in a complex sample. In short, the RNA is size-fractionated by gel electrophoresis and transferred by blotting onto a membrane to which the RNA is covalently bound. Then, the membran...

  17. Northern blotting analysis

    DEFF Research Database (Denmark)

    Josefsen, Knud; Nielsen, Henrik

    2011-01-01

    is analysed by hybridization to one or more specific probes that are labelled for subsequent detection. Northern blotting is relatively simple to perform, inexpensive, and not plagued by artefacts. Recent developments of hybridization membranes and buffers have resulted in increased sensitivity closing...

  18. 1990 Northern, Iran Images

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A magnitude 7.7 earthquake occurred in the Gilan Province between the towns of Rudbar and Manjil in northern Iran on Thursday, June 21, 1990 (June 20 at 21:00 GMT)....

  19. 苏北废黄河三角洲岸线变迁与海岸冲淤动态遥感监测%Remote Sensing Based Dynamic Monitoring of Coastline Change and Coastal Erosion and Deposition of the Abandoned Yellow River Delta in Northern Area of Jiangsu Province

    Institute of Scientific and Technical Information of China (English)

    王志一; 徐素宁; 姜艳辉; 梅军军; 吕铁硬

    2013-01-01

      近几十年来,我国的砂质、淤泥质海岸正呈现侵蚀加剧的演变趋向。随着卫星遥感数据在光谱、时间和空间分辨率方面的不断提高,海岸侵蚀和淤积监测具备了精度越来越高的数据源。在前人研究的基础上,以废黄河三角洲海岸为研究对象,利用遥感技术和野外实地调查对海岸岸线变迁及冲淤动态进行了研究。研究表明:遥感技术在岸线变迁、侵蚀淤积监测和预测方面具有其他技术无可比拟的优势,在海岸带地质环境监测中的应用已成为具有实用价值的技术。%The sandy and silty coast in China has shown an increasing trend of erosion in recent years. The improvement of spec2 tral, temporal, and spatial resolut ion of the satellite remote sensing data has provided the high2accuracy remote sensing data sources for the monitoring of the coastal erosion and deposition. Base on t he previous studies, the remot e sensing technique and filed survey were used to investigate t he coastline change and coastal erosion and deposition of the abandoned Yel ow River Del2 ta in the northern area of Jiangsu province. The results showed that t he remote sensing technique has the unparal eled advanta2 ges for monitoring and predict ing the coastline changes and coastal erosion and deposition compared w ith other technologies, and it has pract ical significance for monit oring the coastal geological environment .

  20. Re-connecting with a Recovering River through Imaginative Engagement

    Directory of Open Access Journals (Sweden)

    Clare Morgan

    2010-09-01

    Full Text Available Imaginative engagement as a mode of citizen participation—the use of arts-based methods to involve people actively in shared learning experiences—holds promise as a means to increase awareness and understanding, and to build capacity, for sustainable use and management of rivers. We conducted a series of creative writing workshops in a former industrial area of northern England that were focused on a "recovering" river. Participants in the workshops found the process a positive experience and reported changes in their knowledge, attitudes, and actions about the use and management of river environments locally and more generally. The "catchment consciousness" of members appeared to increase, and their raised levels of interest led them to invest time in researching the history and geography of the river. We conclude that the method has significant potential for complementing collaborative approaches to river planning and management.

  1. Jokulhlaups and sediment transport in Watson River, Kangerlussuaq, West Greenland

    DEFF Research Database (Denmark)

    Mikkelsen, A. B.; Hasholt, Bent; Knudsen, N. T.

    2013-01-01

    For 3 years, during a 4-year observation period (2007-2010), jokulhlaups were observed from a lake at the northern margin of Russells Gletscher. At a gauging station located on a bedrock sill near the outlet of Watson River into Sdr Stromfjord, discharge and sediment transport was monitored during...

  2. The scroll of Pure Brightness on the River

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    <正>The scroll of Pure Brightness on the River drawn by the Chinese tradi tional painting master Zeduan Zhang depicts a well-off scene of Dongjing (present city of Kaifeng), which was the capital of the Northern Song dynasty a thousand year ago and was the top-ranking metropolis at that time. The scroll

  3. Creating a catchment perspective for river restoration

    Science.gov (United States)

    Benda, L.; Miller, D.; Barquín, J.

    2011-03-01

    One of the major challenges in river restoration is to identify the natural fluvial landscape in catchments with a long history of river control. Intensive land use on valley floors often predates the earliest remote sensing: levees, dikes, dams, and other structures alter valley-floor morphology, river channels and flow regimes. Consequently, morphological patterns indicative of the fluvial landscape including multiple channels, extensive floodplains, wetlands, and fluvial-riparian and tributary-confluence dynamics can be obscured, and information to develop appropriate and cost effective river restoration strategies can be unavailable. This is the case in the Pas River catchment in northern Spain (650 km2), in which land use and development have obscured the natural fluvial landscape in many parts of the basin. To address this issue we coupled general principles of hydro-geomorphic processes with computer tools to characterize the fluvial landscape. Using a 5-m digital elevation model, valley-floor surfaces were mapped according to elevation above the channel and proximity to key geomorphic processes. The predicted fluvial landscape is patchily distributed according to topography, valley morphology, river network structure, and fan and terrace landforms. The vast majority of the fluvial landscape in the main segments of the Pas River catchment is presently masked by human infrastructure, with only 15% not impacted by river control structures and development. The reconstructed fluvial landscape provides a catchment scale context to support restoration planning, in which areas of potential ecological productivity and diversity could be targeted for in-channel, floodplain and riparian restoration projects.

  4. Creating a catchment perspective for river restoration

    Directory of Open Access Journals (Sweden)

    L. Benda

    2011-03-01

    Full Text Available One of the major challenges in river restoration is to identify the natural fluvial landscape in catchments with a long history of river control. Intensive land use on valley floors often predates the earliest remote sensing: levees, dikes, dams, and other structures alter valley-floor morphology, river channels and flow regimes. Consequently, morphological patterns indicative of the fluvial landscape including multiple channels, extensive floodplains, wetlands, and fluvial-riparian and tributary-confluence dynamics can be obscured, and information to develop appropriate and cost effective river restoration strategies can be unavailable. This is the case in the Pas River catchment in northern Spain (650 km2, in which land use and development have obscured the natural fluvial landscape in many parts of the basin. To address this issue we coupled general principles of hydro-geomorphic processes with computer tools to characterize the fluvial landscape. Using a 5-m digital elevation model, valley-floor surfaces were mapped according to elevation above the channel and proximity to key geomorphic processes. The predicted fluvial landscape is patchily distributed according to topography, valley morphology, river network structure, and fan and terrace landforms. The vast majority of the fluvial landscape in the main segments of the Pas River catchment is presently masked by human infrastructure, with only 15% not impacted by river control structures and development. The reconstructed fluvial landscape provides a catchment scale context to support restoration planning, in which areas of potential ecological productivity and diversity could be targeted for in-channel, floodplain and riparian restoration projects.

  5. Development of a Systemwide Program: Stepwise Implementation of a Predation Index, Predator Control Fisheries and Evaluation Plan in the Columbia River Basin, Volume 1, 1992 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Ward, David L.

    1994-06-01

    Results of the second year are reported of a basinwide program to harvest northern squawfish in an effort to reduce mortality due to squawfish predation on juvenile salmonids during their migration from natal streams to the ocean. Six papers are included in this report. They are entitled: feasibility investigation of a commercial longline fishery for northern squawfish in the Columbia River downstream from Bonneville dam; evaluation of the northern squawfish sport-reward fishery in the Columbia and Snake Rivers; controlled angling for northern squawfish at selected dams on the Columbia and Snake Rivers in 1992; evaluation of harvest technology for squawfish control in Columbia River reservoirs; effectiveness of predator-removal for protecting juvenile fall chinook salmon released from Bonneville Hatchery; and Northern squawfish sport-reward payments.

  6. Backwater effects in the Amazon River basin of Brazil

    Science.gov (United States)

    Meade, R.H.; Rayol, J.M.; Da Conceicao, S.C.; Natividade, J.R.G.

    1991-01-01

    The Amazon River mainstem of Brazil is so regulated by differences in the timing of tributary inputs and by seasonal storage of water on floodplains that maximum discharges exceed minimum discharges by a factor of only 3. Large tributaries that drain the southern Amazon River basin reach their peak discharges two months earlier than does the mainstem. The resulting backwater in the lowermost 800 km of two large southern tributaries, the Madeira and Puru??s rivers, causes falling river stages to be as much as 2-3 m higher than rising stages at any given discharge. Large tributaries that drain the northernmost Amazon River basin reach their annual minimum discharges three to four months later than does the mainstem. In the lowermost 300-400 km of the Negro River, the largest northern tributary and the fifth largest river in the world, the lowest stages of the year correspond to those of the Amazon River mainstem rather than to those in the upstream reaches of the Negro River. ?? 1991 Springer-Verlag New York Inc.

  7. Salinization Sources Along the Lower Jordan River Under Draught Conditions

    Science.gov (United States)

    Holtzman, R.; Shavit, U.; Segal, M.; Vengosh, A.; Farber, E.; Gavrieli, I.

    2003-12-01

    The Lower Jordan River, once a flowing freshwater river, is suffering from an ongoing reduction of discharge and water quality. The river flows between the Sea of Galilee and the Dead Sea, an aerial distance of about 105 Km. The severe reduction is caused by an excessive exploitation of its sources and diversion of sewage and agricultural drainage into the river. The extreme low flows and low water quality threaten the natural existence of the river and its potential use for agriculture. In spite of its importance, little research has been done in the river. The objectives of the study were to measure the discharge and water composition along the river and to evaluate the main sources that control its flow and chemical characteristics. The hypothesis of the study was that interaction with subsurface flows significantly affects the river flow and chemical composition. The research is based on a detailed field study, which included flow rate measurements in the river and its tributaries, water sampling and analysis and mass balance calculations of water and solutes. A portable Acoustic Doppler Velocimeter (ADV) was used to measure velocities and bathymetry at different locations across the river sections. Due to accessibility constraints, a floating traverse construction, which enables the ADV's deployment from one bank of the river, was developed. It was found that flow rate ranges between 500-1,100 L/s in northern (upstream) sections and 300-1,650 L/s in the south. This low discharge represents a significant reduction from historical values and is lower than recent published estimations. This research represents base flows only, as the measurements were done during a period of two consecutive draught years. Calculated mass balance of water flows in the northern sections shows that the subsurface source contributes to the river around 200-670 L/s (30-80% of the river flow). Calculations of solute balance show that the subsurface flows add 20-50% of the mass of

  8. Hydrochemistry of inland rivers in the north Tibetan Plateau: Constraints and weathering rate estimation.

    Science.gov (United States)

    Wu, Weihua

    2016-01-15

    The geographic region around the northern and northeastern Tibetan Plateau is the source of several inland rivers (e.g. Tarim River) of worldwide importance that are generated in the surrounding mountains systems of Tianshan, Pamir, Karakorum, and Qilian. To characterize chemical weathering and atmospheric CO2 consumption in these regions, water samples from the Tarim, Yili, Heihe, Shule, and Shiyang Rivers were collected and analyzed for major ion concentrations. The hydrochemical characteristics of these inland rivers pronouncedly distinguish them from large exorheic rivers (e.g., the Yangtze River and the Yellow River), as reflected in very high total dissolution solids (TDS) values. TDS was 115-4345 mg l(-1) with an average of 732 mg l(-1), which is an order of magnitude higher than the mean value for world rivers (65 mg l(-1)). The Cheerchen River, Niya River, Keliya River and the terminal lakes of the Tarim River and the Heihe River have TDS values higher than 1 gl(-1), indicating saline water that cannot be directly consumed. Therefore, the problem of sufficient and safe drinking water has become increasingly prominent in the northwestern China arid zone. According to an inversion model, the contribution from evaporite dissolution to the dissolved loads in these rivers is 12.5%-99% with an average of 54%. The calculated silicate and carbonate weathering rates are 0.02-4.62 t km(-2)y(-1) and 0.01-11.7 t km(-2)y(-1) for these rivers. To reduce the influence of lithology, only the silicate weathering rates in different parts of the Tibetan Plateau are compared. A rough variation tendency can be seen in the rates: northern regional (0.15-1.73 t km(-2)y(-1))runoff, however, seems to have a positive correlation with silicate weathering rates.

  9. Landscape elements and river chemistry as affected by river regulation – a 3-D perspective

    Directory of Open Access Journals (Sweden)

    E. Smedberg

    2008-11-01

    Full Text Available We tested the hypothesis whether individual land classes within a river catchment contribute equally to river loading with dissolved constituents or whether some land classes act as "hot spots" to river loading and if so, are these land classes especially affected by hydrological alterations. The amount of land covered by forests and wetlands and the average soil depth of a river catchment explain 58–93% of the variability in total organic carbon (TOC and dissolved silicate (DSi concentrations for 22 river catchments in Northern Sweden. Whereas only 3% of the headwater areas of the Luleälven have been inundated by the creation of reservoirs, some 10% of the soils and aggregated forest and wetland areas have been lost due to damming and further hydrological alteration such as bypassing entire sub-catchments by headrace tunnels. However, looking at individual forest classes, our estimates indicate that some 37% of the deciduous forests have been inundated by the four major reservoirs built in the Luleälven headwaters. These deciduous forest and wetlands formerly growing on top of alluvial deposits along the river corridors forming the riparian zone play a vital role in loading river water with dissolved constituents, especially DSi. A digital elevation model draped with land classes and soil depths which highlights that topography of various land classes acting as hot spots is critical in determining water residence time in soils and biogeochemical fluxes. Thus, headwater areas of the Luleälven appear to be most sensitive to hydrological alterations due to the thin soil cover (on average 2.7–4.5 m and only patchy appearance of forest and wetlands that were significantly perturbed. Moreover, since these headwater areas are characterized often by high specific discharge, this relatively minor change in the landscape when compared to the entire river catchment may indeed explain the significant lower fluxes at the river mouth.

  10. Neotectonics in the northern equatorial Brazilian margin

    Science.gov (United States)

    Rossetti, Dilce F.; Souza, Lena S. B.; Prado, Renato; Elis, Vagner R.

    2012-08-01

    An increasing volume of publications has addressed the role of tectonics in inland areas of northern Brazil during the Neogene and Quaternary, despite its location in a passive margin. Hence, northern South America plate in this time interval might have not been as passive as usually regarded. This proposal needs further support, particularly including field data. In this work, we applied an integrated approach to reveal tectonic structures in Miocene and late Quaternary strata in a coastal area of the Amazonas lowland. The investigation, undertaken in Marajó Island, mouth of the Amazonas River, consisted of shallow sub-surface geophysical data including vertical electric sounding and ground penetrating radar. These methods were combined with morphostructural analysis and sedimentological/stratigraphic data from shallow cores and a few outcrops. The results revealed two stratigraphic units, a lower one with Miocene age, and an upper one of Late Pleistocene-Holocene age. An abundance of faults and folds were recorded in the Miocene deposits and, to a minor extent, in overlying Late Pleistocene-Holocene strata. In addition to characterize these structures, we discuss their origin, considering three potential mechanisms: Andean tectonics, gravity tectonics related to sediment loading in the Amazon Fan, and rifting at the continental margin. Amongst these hypotheses, the most likely is that the faults and folds recorded in Marajó Island reflect tectonics associated with the history of continental rifting that gave rise to the South Atlantic Ocean. This study supports sediment deposition influenced by transpression and transtension associated with strike-slip divergence along the northern Equatorial Brazilian margin in the Miocene and Late Pleistocene-Holocene. This work records tectonic evidence only for the uppermost few ten of meters of this sedimentary succession. However, available geological data indicate a thickness of up to 6 km, which is remarkably thick for

  11. Socio-hydrology and integrated water resources management in northern Australia

    Science.gov (United States)

    Douglas, Michael; Jackson, Sue

    2017-04-01

    Australia's tropical rivers account for more than half of the nation's freshwater resources. Nearly all of these rivers flow freely to the sea, with less than 0. 01% of river flows diverted for human use, but there is increasing interest in developing the region's water resources for irrigated agriculture. Interdisciplinary research conducted over the past decade has demonstrated the reliance of biodiversity on free-flowing rivers and has also identified a broad range of benefits that people derive from these river systems including irrigated agriculture, tourism, commercial and recreational fishing and Indigenous subsistence harvesting. This has revealed the highly coupled nature of the socio-hydrological system in northern Australia's catchments and the trade-offs among different water users. This paper provides an overview of past and current research with a focus on how socio-hydrology may assist in undertaking integrated water resource management in this region.

  12. A New Xeromorphic Species of Clusia (Clusiaceae) from Dry Valleys of Northern Peru

    DEFF Research Database (Denmark)

    Gustafsson, Mats

    2010-01-01

    Clusia magnoliiflora M. H. G. Gust. is described as new for the Clusiaceae. It grows in dry scrub in the river valleys of the Marañón and its tributaries in northern Peru, a kind of habitat that harbors very few Clusia species. The species is distinct on account of its extremely thick, obovate...

  13. Fine Root Dynamics and Forest Production Across a Calcium Gradient in Northern Hardwood and Conifer Ecosystems

    Science.gov (United States)

    Byung Bae Park; Ruth D. Yanai; Timothy J. Fahey; Scott W. Bailey; Thomas G. Siccama; James B. Shanley; Natalie L. Cleavitt

    2008-01-01

    Losses of soil base cations due to acid rain have been implicated in declines of red spruce and sugar maple in the northeastern USA. We studied fine root and aboveground biomass and production in five northern hardwood and three conifer stands differing in soil Ca status at Sleepers River, VT; Hubbard Brook, NH; and Cone Pond, NH. Neither aboveground biomass and...

  14. At the Foot of the Mountain : Systematic investigations of protohistoric settlement in Northern Calabria

    NARCIS (Netherlands)

    de Neef, Wieke; van Leusen, Martijn; Armstrong, Kayt

    2014-01-01

    The Rural Life in Protohistoric Italy project (2010-2015) investigates small surface sites in a river basin at the southern end of the Apennine range, in northern Calabria. The basin is composed of an (uninvestigated) coastal plain, a foothill zone where most medieval to modern habitation is concent

  15. A simple DEM assessment procedure for gully system analysis in the Lake Manyara area, northern Tanzania

    NARCIS (Netherlands)

    Maerker, Michael; Quénéhervé, Geraldine; Bachofer, Felix; Mori, Simone

    2015-01-01

    Gully erosion is a major threat concerning landscape degradation in large areas along the northern Tanzanian Rift valley. It is the dominant erosion process producing large parts of the sediments that are effectively conducted into the river network. The study area is located in the Lake Manyara—

  16. Northern corn rootworm (Diabrotica barberi) populations infected by at least 5 Wolbachia strains

    Science.gov (United States)

    Wolbachia infections are present in northern corn rootworm (Diabrotica barberi) populations from east of the Mississippi River. The boundary between infected and uninfected populations is in central Illinois. DNA sequencing of Wolbachia ftsZ and wsp segments indicates that east central Illinois popu...

  17. Management scenarios for the Jordan River salinity crisis

    Science.gov (United States)

    Farber, E.; Vengosh, A.; Gavrieli, I.; Marie, A.; Bullen, T.D.; Mayer, B.; Holtzman, R.; Segal, M.; Shavit, U.

    2005-01-01

    Recent geochemical and hydrological findings show that the water quality of the base flow of the Lower Jordan River, between the Sea of Galilee and the Dead Sea, is dependent upon the ratio between surface water flow and groundwater discharge. Using water quality data, mass-balance calculations, and actual flow-rate measurements, possible management scenarios for the Lower Jordan River and their potential affects on its salinity are investigated. The predicted scenarios reveal that implementation of some elements of the Israel-Jordan peace treaty will have negative effects on the Jordan River water salinity. It is predicted that removal of sewage effluents dumped into the river (???13 MCM/a) will significantly reduce the river water's flow and increase the relative proportion of the saline groundwater flux into the river. Under this scenario, the Cl content of the river at its southern point (Abdalla Bridge) will rise to almost 7000 mg/L during the summer. In contrast, removal of all the saline water (16.5 MCM/a) that is artificially discharged into the Lower Jordan River will significantly reduce its Cl concentration, to levels of 650-2600 and 3000-3500 mg/L in the northern and southern areas of the Lower Jordan River, respectively. However, because the removal of either the sewage effluents or the saline water will decrease the river's discharge to a level that could potentially cause river desiccation during the summer months, other water sources must be allocated to preserve in-stream flow needs and hence the river's ecosystem. ?? 2005 Elsevier Ltd. All rights reserved.

  18. Seismicity in Northern Germany

    Science.gov (United States)

    Bischoff, Monika; Gestermann, Nicolai; Plenefisch, Thomas; Bönnemann, Christian

    2013-04-01

    Northern Germany is a region of low tectonic activity, where only few and low-magnitude earthquakes occur. The driving tectonic processes are not well-understood up to now. In addition, seismic events during the last decade concentrated at the borders of the natural gas fields. The source depths of these events are shallow and in the depth range of the gas reservoirs. Based on these observations a causal relationship between seismicity near gas fields and the gas production is likely. The strongest of these earthquake had a magnitude of 4.5 and occurred near Rotenburg in 2004. Also smaller seismic events were considerably felt by the public and stimulated the discussion on the underlying processes. The latest seismic event occurred near Langwedel on 22nd November 2012 and had a magnitude of 2.8. Understanding the causes of the seismicity in Northern Germany is crucial for a thorough evaluation. Therefore the Seismological Service of Lower Saxony (NED) was established at the State Office for Mining, Energy and Geology (LBEG) of Lower Saxony in January 2013. Its main task is the monitoring and evaluation of the seismicity in Lower Saxony and adjacent areas. Scientific and technical questions are addressed in close cooperation with the Seismological Central Observatory (SZO) at the Federal Institute for Geosciences and Natural Resources (BGR). The seismological situation of Northern Germany will be presented. Possible causes of seismicity are introduced. Rare seismic events at greater depths are distributed over the whole region and probably are purely tectonic whereas events in the vicinity of natural gas fields are probably related to gas production. Improving the detection threshold of seismic events in Northern Germany is necessary for providing a better statistical basis for further analyses answering these questions. As a first step the existing seismic network will be densified over the next few years. The first borehole station was installed near Rethem by BGR

  19. Mercury Enrichment in Sediments of the Coastal Area of Northern Latium, Italy.

    Science.gov (United States)

    Scanu, Sergio; Piazzolla, Daniele; Frattarelli, Francesco Manfredi; Mancini, Emanuele; Tiralongo, Francesco; Brundo, Maria Violetta; Tibullo, Daniele; Pecoraro, Roberta; Copat, Chiara; Ferrante, Margherita; Marcelli, Marco

    2016-05-01

    The purpose of this study was to evaluate the extent of the Hg geochemical anomaly arising in the Amiata and Tolfa complex to the coastal area of northern Latium and to examine the possible influence on this area by the Mignone River, and by the small coastal basins, which are characterized by both previous mining activities and decades of past industrial impact. The results confirm the extension of the anomaly of concentrations of Hg in the coastal area of northern Latium, with the northern sector influenced by the contributions of the Fiora and Mignone Rivers and the southern sector influenced by the contributions of minor basins. The results show high values of the Adverse Effect Index throughout the considered area and highlight the need for further investigation in order to assess the impact of human activities on the present and past values of Hg in marine sediments.

  20. The effects of industrial and agricultural activity on the water quality of the Sitnica River (Kosovo)

    OpenAIRE

    Albona Shala; Fatbardh Sallaku; Agron Shala; Shkëlzim Ukaj

    2015-01-01

    An important issue in Kosovo is water pollution. The use of polluted water has a direct impact on human health and cause long-term consequences. The longest and most polluted river in Kosovo is the Sitnica, a 90 km long river with its source located near the village of Sazli. The river flows into the Ibar River in Northern Kosovo. Agriculture is prevailing activity in the basin of Sitnica which is why agricultural as well as industrial waste are the biggest water pollutants. The purpose of th...

  1. River Morphology and River Channel Changes

    Institute of Scientific and Technical Information of China (English)

    CHANG Howard H

    2008-01-01

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

  2. Northern Pintail Telemetry [ds231

    Data.gov (United States)

    California Department of Resources — Using radio-telemetry, female northern pintail (Anas acuta) survival, distribution, and movements during late August-March in Central California were determined...

  3. Rivers as Political Boundaries: Peru and its Dynamic Borders

    Science.gov (United States)

    Abad, J. D.; Escobar, C.; Garcia, A. M. P.; Ortals, C.; Frias, C. E.; Vizcarra, J.

    2014-12-01

    Rivers, although inherently dynamic, have been chosen as political boundaries since the beginning of colonization for several reasons. Such divisions were chosen namely for their defensive capabilities and military benefits, and because they were often the first features mapped out by explorers. Furthermore, rivers were indisputable boundaries that did not require boundary pillars or people to guard them. However, it is important to understand the complexities of a river as a boundary. All rivers inevitably change over time through processes such as accretion, deposition, cut-off, or avulsion, rendering a political boundary subject to dispute. Depending upon the flow, size, and surrounding land, a river will migrate differently than others. As these natural features migrate one country loses land while another gains land leading to tension between legal rigidity and fluid dynamism. This in turn can manifest in social disruption due to cultural differences, political upheaval, or conflict risk as a result of scarce water resources. The purpose of this research is to assess the temporal and spatial variability of the political boundaries of Peru that follow rivers. Peru shares borders with Colombia, Brazil, Bolivia, Chile, and Ecuador. A large part of its northern border with Colombia follows the Putumayo River and later the Amazon River. Part of its eastern border with Brazil follows the Yavari River and later the Yaquirana River. These rivers are natural features used as political boundaries yet they differ in how each migrates. By means of a spatial and temporal analysis of satellite images it was possible to obtain erosion and deposition areas for the Putumayo River, the portion of the Amazon River that is part of the Peruvian boundary, the Yavari River, and the Yaquirana River. The erosion and deposition areas were related to land distribution among Peru, Colombia, and Brazil. By examining the Digital Elevation Model one can see how the altitude of the

  4. Indicadores de condición larvaria aplicados al camarón de río del norte Cryphiops caementarius (Molina, 1782, en condiciones de cultivo controlado Larval condition indicators applied to the northern river shrimp Cryphiops caementarius (Molina, 1782, under condition of controlled cultivation

    Directory of Open Access Journals (Sweden)

    María C Morales

    2012-09-01

    Full Text Available Se estudia el desarrollo larvario del camarón de río del norte de Chile, Cryphiops caementarius, desde el estado de zoea 1 hasta el primer juvenil, caracterizando y analizando criterios que verificaron la aplicación de indicadores de tipo morfológico y de comportamiento para la evaluación de la condición larvaria de la especie, en condiciones de cultivo. Las larvas, se mantuvieron en cultivo, en un tanque de 250 L con agua a 20 psu y temperatura de 25 ± 1°C, controlada con termostato y con un recambio del 100% diariamente. La alimentación consistió en microalgas (Nannochloris sp. e Isochrysis sp., rotíferos (Brachionus plicatilis, nauplios de Artemia franciscana y alimento formulado. Se utilizaron cinco indicadores de carácter morfológico y de comportamiento aplicados a las larvas de C. caementarius: llenado intestinal, estado de la glándula digestiva, desarrollo branquial, comportamiento natatorio y respuesta fototáctica. Estos indicadores, permitieron determinar el estado de condición y calidad de las larvas de C. caementarius, logrando un efectivo seguimiento y asociación de cada uno de ellos, con cada estado de desarrollo larvario, estandarizando características deseables en las larvas y evidenciando resultados verificables, que permitan establecer un adecuado plan de seguimiento del cultivo, optimizar los protocolos de manejo y de alimentación de las larvas. Además de cada indicador, fue posible desglosar una amplia gama de potenciales estudios a realizar, basados en las relaciones que la morfología y el comportamiento larvario mantienen con las capacidades fisiológicas de las larvas en desarrollo.The larval development of the Chilean northern river shrimp Cryphiops caementarius was studied, from the condition of zoea 1 up to the condition of juvenile stage, analyzing and characterizing diverse criteria that allowed checking the application of morphological and behavioral indicators for the evaluation of the larval

  5. Comparative Study on Rural Residents Tourism Characteristics between the Pearl River Delta Region and the Northern Region of Guangdong Province%珠三角与粤北地区农村居民旅游认知特征对比分析

    Institute of Scientific and Technical Information of China (English)

    叶延琼; 罗宇萍; 章家恩

    2011-01-01

    对珠三角的广州、东莞、佛山、江门以及粤北地区的韶关、清远和河源7个代表样地共计14个样本镇的1 120人(户)进行了农村居民旅游态度与出游特征问卷调查,并对1 040份有效样本从人口特征、旅游认知特征和旅游消费行为特征等方面进行详细分析.结果表明:(1)珠三角地区和粤北地区农村居民对旅游的态度普遍较好,但获取旅游信息的渠道均较单一;(2)限制农民出游的主要因素是经济收入状况,时间因素也限制了部分人,尤其是中青年人;(3)由于珠三角和粤北地区经济发展水平差异较大,因此农村居民在出游动机、出游方式、出游交通工具选择、出游时间以及旅游花费上存在较大差异;(4)受农村传统观念的影响,两地农村居民在出游偏好以及消费结构上均表现出较高的一致性.%Questionnaires were distributed to 1120 rural residents of Guangzhou, Dongguan, Foshan and Jiangmen in the Pearl River Delta region, and Shaoguan, Qingyuan and Heyuan in the northern mountain region of Guangdong Province in 2008 to survey their attitudes to travel, of which 1040 valid samples were analyzed in terms of the rural residents' demographic characteristics and tourism consumer behavior features. Some conclusions were drawn as follows: 1) Rural residents had positive attitudes to tourism in the two study regions but their means of getting tourism information was single. 2) The main limited factors for rural residents' travel were low economic income, deficiency of time in the farming seasons and everyday household duties for rural residents, especially for young and middle-aged people. 3 ) There were big difference in tourism motivation, tourism patterns, tourism transports, tourism time and tourism expenses between the two regions. 4 ) Affected by the rural traditional concepts, the preferences of travel and consumption structure of the rural people in the two regions were consistent.

  6. Using probability-based spatial estimation of the river pollution index to assess urban water recreational quality in the Tamsui River watershed.

    Science.gov (United States)

    Jang, Cheng-Shin

    2016-01-01

    The Tamsui River watershed situated in Northern Taiwan provides a variety of water recreational opportunities such as riverbank park activities, fishing, cruising, rowing, sailing, and swimming. However, river water quality strongly affects water recreational quality. Moreover, the health of recreationists who are partially or fully exposed to polluted river water may be jeopardized. A river pollution index (RPI) composed of dissolved oxygen, biochemical oxygen demand, suspended solids, and ammonia nitrogen is typically used to gauge the river water quality and regulate the water body use in Taiwan. The purpose of this study was to probabilistically determine the RPI categories in the Tamsui River watershed and to assess the urban water recreational quality on the basis of the estimated RPI categories. First, according to various RPI categories, one-dimensional indicator kriging (IK) was adopted to estimate the occurrence probabilities of the RPI categories. The maximum occurrence probability among the categories was then employed to determine the most suitable RPI category. Finally, the most serious categories and seasonal variations of RPI were adopted to evaluate the quality of current water recreational opportunities in the Tamsui River watershed. The results revealed that the midstream and downstream sections of the Tamsui River and its tributaries with poor river water quality afford low water recreational quality, and water recreationists should avoid full or limited exposure to these bodies of water. However, the upstream sections of the Tamsui River watershed with high river water quality are suitable for all water recreational activities.

  7. Qingjiang River Developer

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

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

  8. Illinois River NWFR HMP

    Data.gov (United States)

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

  9. Allegheny County Major Rivers

    Data.gov (United States)

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

  10. Iowa's Sovereign Meandered Rivers

    Data.gov (United States)

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

  11. Diversifying natural resources value measurements: The Trinity River study

    Science.gov (United States)

    Taylor, J.G.; Douglas, A.J.

    1999-01-01

    An interdisciplinary team set out to establish the economic and social values of the Trinity River in northern California. This information was intended to support the Secretary of the Interior's decision on allocation of Trinity River flows. This team set out to measure the values of Trinity River flows, fishery resources, and recreation amenities in several different ways. A survey was mailed to users of the Trinity River. This single instrument included economic measures (willingness-to-pay and costs incurred in visiting) and social-psychological measures (importance, satisfaction, and water allocation preferences). A closely related survey measured several of these same values among west coast regional households. The results of these surveys were compiled, and the measured economic and social values were compared. We found that integrating economic and social value information provides a greater depth of understanding of the resource's value. In addition, this integration provides a more in-depth understanding through the quantitative and qualitative results that emerge.

  12. The Quaternary thrust system of the northern Alaska Range

    Science.gov (United States)

    Bemis, Sean P.; Carver, Gary A.; Koehler, Richard D.

    2012-01-01

    The framework of Quaternary faults in Alaska remains poorly constrained. Recent studies in the Alaska Range north of the Denali fault add significantly to the recognition of Quaternary deformation in this active orogen. Faults and folds active during the Quaternary occur over a length of ∼500 km along the northern flank of the Alaska Range, extending from Mount McKinley (Denali) eastward to the Tok River valley. These faults exist as a continuous system of active structures, but we divide the system into four regions based on east-west changes in structural style. At the western end, the Kantishna Hills have only two known faults but the highest rate of shallow crustal seismicity. The western northern foothills fold-thrust belt consists of a 50-km-wide zone of subparallel thrust and reverse faults. This broad zone of deformation narrows to the east in a transition zone where the range-bounding fault of the western northern foothills fold-thrust belt terminates and displacement occurs on thrust and/or reverse faults closer to the Denali fault. The eastern northern foothills fold-thrust belt is characterized by ∼40-km-long thrust fault segments separated across left-steps by NNE-trending left-lateral faults. Altogether, these faults accommodate much of the topographic growth of the northern flank of the Alaska Range.Recognition of this thrust fault system represents a significant concern in addition to the Denali fault for infrastructure adjacent to and transecting the Alaska Range. Although additional work is required to characterize these faults sufficiently for seismic hazard analysis, the regional extent and structural character should require the consideration of the northern Alaska Range thrust system in regional tectonic models.

  13. Sources of water used by natural mesquite vegetation in a semi-arid region of northern Mexico

    OpenAIRE

    2009-01-01

    Vegetation structure in semi-arid regions of northern Mexico and the southwestern USA has changed dramatically over the last century; shrubs such as mesquite (Prosopis sp.) have expanded into, and have become dominant in, ecosystems that once supported semi-arid grassland. The upper San Pedro River watershed, which extends from northern Sonora (Mexico) to southeastern Arizona (USA), highlights these changes. Between 1973 and 1992, grasslands decreased by 18% and the total area dominated by me...

  14. Development of a Systemwide Predator Control Program, Section I : Northern Squawfish Management Program Implementation, 1994 annual report.

    Energy Technology Data Exchange (ETDEWEB)

    Willis, Charles F. (S.P. Cramer and Associates, Inc., Gresham, OR); Young, Franklin R. (Columbia Basin Fish and Wildlife Authority, Portland, OR)

    1995-09-01

    The authors report the results from the forth year of a basinwide program to harvest northern squawfish (Ptychocheilus oregonensis) in an effort to reduce mortality due to northern squawfish predation on juvenile salmonids during their emigration from natal streams to the ocean. Earlier work in the Columbia River Basin suggested predation by northern squawfish on juvenile salmonids may account for most of the 10--20% mortality juvenile salmonids experience in each of eight Columbia and Snake River reservoirs. Modeling simulations based on work in John Day Reservoir from 1982 through 1988 indicated it is not necessary to eradicate northern squawfish to substantially reduce predation-caused mortality of juvenile salmonids. Instead, if northern squawfish were exploited at a 10--20% rate, reductions in numbers of larger, older fish resulting in restructuring of their population could reduce their predation on juvenile salmonids by 50% or more. Consequently, the authors designed and tested a sport-reward angling fishery and a commercial longline fishery in the John Day pool in 1990. They also conducted an angling fishery in areas inaccessible to the public at four dams on the mainstem Columbia River and at Ice Harbor Dam on the Snake River. Based on the success of these limited efforts, they implemented three test fisheries on a multi-pool, or systemwide, scale in 1991--a tribal longline fishery above Bonneville Dam, a sport-reward fishery, and a dam-angling fishery.

  15. Fertilization in northern forests

    DEFF Research Database (Denmark)

    Hedwall, Per Ola; Gong, Peichen; Ingerslev, Morten

    2014-01-01

    resources into food, health and industrial products and energy. Fertilization in Sweden and Finland is currently practiced by extensive fertilization regimens where nitrogen fertilizers are applied once, or up to three times, during a rotation period, mainly in mature forest. This type of fertilization......Forests of northern ecosystems respond slowly to management activities and the possibilities to increase the growth in a short-term perspective and meet swift increases in society's demand for biomass are small. An exception among the silvicultural measures is fertilization which can be applied...... in combination with present management systems and, almost instantly, enhances forest productivity. There may, however, be both economic and environmental constraints to large-scale applications of fertilizers in forest. Here we review the literature concerning biomass production of forests under different...

  16. Glyphosate in northern ecosystems.

    Science.gov (United States)

    Helander, Marjo; Saloniemi, Irma; Saikkonen, Kari

    2012-10-01

    Glyphosate is the main nonselective, systemic herbicide used against a wide range of weeds. Its worldwide use has expanded because of extensive use of certain agricultural practices such as no-till cropping, and widespread application of glyphosate-resistant genetically modified crops. Glyphosate has a reputation of being nontoxic to animals and rapidly inactivated in soils. However, recent evidence has cast doubts on its safety. Glyphosate may be retained and transported in soils, and there may be cascading effects on nontarget organisms. These processes may be especially detrimental in northern ecosystems because they are characterized by long biologically inactive winters and short growing seasons. In this opinion article, we discuss the potential ecological, environmental and agricultural risks of intensive glyphosate use in boreal regions.

  17. Riverine based eco-tourism: Trinity River non-market benefits estimates

    Science.gov (United States)

    Douglas, A.J.; Taylor, J.G.

    1998-01-01

    California's Central Valley Project (CVP) was approved by voters in a statewide referendum in 1933. CVP referendum approval initiated funding for construction of important water development projects that had far reaching effects on regional water supplies. The construction of Trinity Dam in 1963 and the subsequent transbasin diversion of Trinity River flow was one of several CVP projects that had noteworthy adverse environmental and regional economic impacts. The Trinity River is the largest tributary of the Klamath River, and has its headwaters in the Trinity Alps of north-central California. After the construction of Trinity Dam in 1963, 90% of the Trinity River flow at Lewiston was moved to the Sacramento River via the Clear Creek Tunnel. Before 1963, the Trinity River was a major recreation resource of Northern California. The loss of streamflow has had a marked adverse impact on Trinity River-related recreation activities and the size and robustness of Trinity River salmon, steelhead, shad, and sturgeon runs. Trinity River water produces hydropower during its transit via Bureau of Reclamation canals and pumps to the northern San Joaquin Valley, where it is used for irrigated agriculture. The benefits provided by Trinity River instream flow-related environmental amenities were estimated with the travel cost method (TCM). Trinity River non-market benefits are about $406 million per annum, while the social cost of sending water down the Trinity River ranges from $17 to $42 million per annum, depending on the exact flow. We also discuss the relative magnitude of Trinity River survey data contingent value method (CVM) benefits estimates.

  18. Enhancing the Predicting Accuracy of the Water Stage Using a Physical-Based Model and an Artificial Neural Network-Genetic Algorithm in a River System

    National Research Council Canada - National Science Library

    Wen-Cheng Liu; Chuan-En Chung

    2014-01-01

    ...) and genetic algorithm neural network (GANN) techniques, to improve predictions from a one-dimensional flood routing hydrodynamic model regarding the water stages during typhoon events in the Danshuei River system in northern Taiwan...

  19. Towards integrated assessment of the northern Adriatic Sea sediment budget using remote sensing

    Science.gov (United States)

    Taramelli, A.; Filipponi, F.; Valentini, E.; Zucca, F.; Gutierrez, O. Q.; Liberti, L.; Cordella, M.

    2014-12-01

    Understanding the factors influencing sediment fluxes is a key issue to interpret the evolution of coastal sedimentation under natural and human impact and relevant for the natural resources management. Despite river plumes represent one of the major gain in sedimentary budget of littoral cells, knowledge of factors influencing complex behavior of coastal plumes, like river discharge characteristics, wind stress and hydro-climatic variables, has not been yet fully investigated. Use of Earth Observation data allows the identification of spatial and temporal variations of suspended sediments related to river runoff, seafloor erosion, sediment transport and deposition processes. Objective of the study is to investigate sediment fluxes in northern Adriatic Sea by linking suspended sediment patterns of coastal plumes to hydrologic and climatic forcing regulating the sedimentary cell budget and geomorphological evolution in coastal systems and continental shelf waters. Analysis of Total Suspended Matter (TSM) product, derived from 2002-2012 MERIS time series, was done to map changes in spatial and temporal dimension of suspended sediments, focusing on turbid plume waters and intense wind stress conditions. From the generated multi temporal TSM maps, dispersal patterns of major freshwater runoff plumes in northern Adriatic Sea were evaluated through spatial variability of coastal plumes shape and extent. Additionally, sediment supply from river distributary mouths was estimated from TSM and correlated with river discharge rates, wind field and wave field through time. Spatial based methodology has been developed to identify events of wave-generated resuspension of sediments, which cause variation in water column turbidity, occurring during intense wind stress and extreme metocean conditions, especially in the winter period. The identified resuspension events were qualitatively described and compared with to hydro-climatic variables. The identification of spatial and

  20. Environmental Impact Study of The Northern Section of the Upper Mississippi River, Minnesota River Pool.

    Science.gov (United States)

    1973-11-01

    Continued) IBidens beckii Water marigold Bidens connata Beggar’s ticks Bidens sp. Bur marigold P P P P Carduus nutans Musk thistle ICirsium arvense...112 Identification of Impacts .. .. ............. 112 Discussion of Impacts. .. ................ 120IImpoundmen6t E’ffcts. .. .............. 121...32 (Cont.) Identification of impacts .. .. ............. 132 Industrial Impacts. ................. 132 Recreational impacts .. .. ............. 133

  1. Environmental Impact Study of the Northern Section of the Upper Mississippi River, St. Croix River Pool.

    Science.gov (United States)

    1973-11-01

    Shrubs (Cont’d.) JUGLANDACEAE I Carya cordifo2ViS Bitternut hickory P P LEGUMINOSAE : see FABACEAE MORACEAE i Morus rubra Red mulberry P OLEACEAE... LEGUMINOSAE Amorpha canescens (Prairie Lead Plant) Astragalus crassicarpus (Ground Plum) Melilotus alba (White Sweet Clover) Petalosternum candidum

  2. Towards Biological Restoration of Tehran Megalopolis River Valleys- Case Study: Farahzad River

    Science.gov (United States)

    Samadi, Nafishe; Oveis Torabi, Seyed; Akhani, Hossein

    2017-04-01

    Towards biological restoration of Tehran megalopolis river-valleys: case study Farahzad river 1Nafiseh Samadi, 2OveisTorabi, 3Hossein Akhani 1Mahsab Shargh Company, Tehran ,Iran, nafiseh19@gmail.com 2 Mahsab Shargh Company, Tehran ,Iran, weg@tna-co.com 3Department of Plant Sciences, Halophytes and C4 Research Laboratory, School of Biology, College of Sciences, University of Tehran, PO Box 14155-6455, Tehran, Iran, akhani@khayam.ut.ac.ir Tehran is located in northcentral parts of Iran on the alluvium of southern Alborz Mountains. Seven rivers originated from the highlands of N Tehran run inside and around the city. Many of these river valleys have been deformed by a variety of urban utilizations such as garden, building, canal, park, autobahn etc. Tehran with more than eight million populations suffered from adverse environmental conditions such as pollution and scarcity of natural habitats for recreational activities. Ecological restoration of altered river valleys of Tehran is one of the priorities of Tehran municipality started as a pilot project in Farahzad river. Intensive disturbance, conversion into various urban utilization, illegal building construction, waste water release into the river, garbage accumulation, artificial park constructions and domination of invasive species have largely altered the river. Parts of the river located in Pardisan Nature Park was studied before its complete deformation into a modern park. The riparian vegetation consisted of Tamarix ramosissima and Salix acmophylla shrubs with large number of aquatic and palustric plants. The norther parts of the river still contain semi-natural vegetation which change into patchy and intensive degraded habitats towards its southern parts. In northern parts of valley there are old gardens of Morus alba and Juglans regia, and planted trees such as Plataneus oreientalis and Acer negundo. Salix acmophylla, Fraxinus excelsior and Celtis caucasica are native species growing on river margin or

  3. Geographic determinants of leprosy in Karonga District, Northern Malawi.

    Science.gov (United States)

    Sterne, J A; Pönnighaus, J M; Fine, P E; Malema, S S

    1995-12-01

    Researchers do not understand how geographical differences relate to the risk of contracting leprosy. The study of such differences, however, may provide clues about the natural history of the disease. The authors report findings from an analysis of the geographical distribution of leprosy in Karonga District, a rural area in Northern Malawi, between 1979 and 1989. Findings are based data from two total population surveys. The areas of residence were determined using aerial photographs, which allowed the identification of households, roads, rivers, and the lake shore. Analysis revealed that incidence rates were 2-3 times higher in the north compared to the south of the district, and lowest in the semi-urban district capital. The north has higher rainfall and more fertile soil. There was no overall association between the incidence of leprosy and population density, although the highest rates were observed in the least densely populated areas. Considering the entire district, incidence rates increased with increasing distance from a main road, but declined with increasing distance from a river or from the shore of Lake Malawi. This negative association with proximity to rivers may reflect the larger number of rivers in the north of the district. Apparent differences in incidence rates between groups speaking different languages reflected confounding by area of residence. The authors conclude that there is a marked variation, not explained by socioeconomic or cultural factors, in the incidence of leprosy within Karonga District. These results are consistent with literature which associates the environment, especially proximity to water, with leprosy.

  4. Upscaling river biomass using dimensional analysis and hydrogeomorphic scaling

    Science.gov (United States)

    Barnes, Elizabeth A.; Power, Mary E.; Foufoula-Georgiou, Efi; Hondzo, Miki; Dietrich, William E.

    2007-12-01

    We propose a methodology for upscaling biomass in a river using a combination of dimensional analysis and hydro-geomorphologic scaling laws. We first demonstrate the use of dimensional analysis for determining local scaling relationships between Nostoc biomass and hydrologic and geomorphic variables. We then combine these relationships with hydraulic geometry and streamflow scaling in order to upscale biomass from point to reach-averaged quantities. The methodology is demonstrated through an illustrative example using an 18 year dataset of seasonal monitoring of biomass of a stream cyanobacterium (Nostoc parmeloides) in a northern California river.

  5. River ecosystem response to prescribed vegetation burning on Blanket Peatland.

    Directory of Open Access Journals (Sweden)

    Lee E Brown

    Full Text Available Catchment-scale land-use change is recognised as a major threat to aquatic biodiversity and ecosystem functioning globally. In the UK uplands rotational vegetation burning is practised widely to boost production of recreational game birds, and while some recent studies have suggested burning can alter river water quality there has been minimal attention paid to effects on aquatic biota. We studied ten rivers across the north of England between March 2010 and October 2011, five of which drained burned catchments and five from unburned catchments. There were significant effects of burning, season and their interaction on river macroinvertebrate communities, with rivers draining burned catchments having significantly lower taxonomic richness and Simpson's diversity. ANOSIM revealed a significant effect of burning on macroinvertebrate community composition, with typically reduced Ephemeroptera abundance and diversity and greater abundance of Chironomidae and Nemouridae. Grazer and collector-gatherer feeding groups were also significantly less abundant in rivers draining burned catchments. These biotic changes were associated with lower pH and higher Si, Mn, Fe and Al in burned systems. Vegetation burning on peatland therefore has effects beyond the terrestrial part of the system where the management intervention is being practiced. Similar responses of river macroinvertebrate communities have been observed in peatlands disturbed by forestry activity across northern Europe. Finally we found river ecosystem changes similar to those observed in studies of wild and prescribed forest fires across North America and South Africa, illustrating some potentially generic effects of fire on aquatic ecosystems.

  6. The Plant Foliage Projective Coverage Change over the Northern Tibetan Plateau during 1957-2009

    Science.gov (United States)

    Cuo, L.

    2015-12-01

    Northern Tibetan Plateau is the headwater of the Yellow River, the Yangtze River and the Mekong River that support billions of the population. Vegetation change will affect the regional ecosystem and water balances through the changes in biomass and evapotranspiration. Dynamic vegetation growth is determined by physiological, morphological, bioclimatic and phenological properties. These properties are affected by climate variables such as air temperature, precipitation, soil temperature and concentration of CO2, etc. Due to climate change, some parts of the northern Tibetan Plateau are under the threat of desertification. Identifying the places of vegetation degradation and the dominant driven climatic factors will help mitigate the climate change impacts on ecosystem and water resources in this region. In this study, the changes of foliage projective coverages (FPCs) of various plant functional types (PFTs) existed in the northern Tibetan Plateau and the responses of FPCs to the four climate variables over 1957-2009 are examined. The dominant factors among the four climate variables are also identified. The Lund-Potsdam-Jena Dynamic Global Vegetation Model (LPJ-DGVM) is modified and used for the investigation. The modified LPJ-DGVM can better account for soil temperature in the top 0.4-m depth where vegetation root concentrates over the northern Tibetan Plateau. The modified model is evaluated by using monthly and annual soil temperature observed at stations across the region, and the eco-geographic maps that describe plant types and spatial distributions developed from field surveys and satellite images for this region.

  7. Mercury Transport During Snowmelt in Three Mountain Watersheds in Northern Utah, USA

    Science.gov (United States)

    Packer, B. N.; Carling, G. T.; Tingey, D. G.

    2015-12-01

    Mercury (Hg) transport during snowmelt is widely recognized as a significant source of Hg to high elevation lakes and streams. However, it is not well understood to what extent Hg is associated with suspended sediment versus dissolved organic matter during snowmelt runoff. To investigate Hg transport during snowmelt, we collected samples for filtered and unfiltered total Hg (THg) and dissolved organic carbon (DOC) in snowpack and snowmelt runoff across three snow-dominated watersheds in northern Utah: Logan River, Provo River, and Little Cottonwood Creek. The watersheds were selected to cover a range of geologic and hydrologic conditions typical of the Rocky Mountain region. Initial results show that snowpack THg concentrations were similar across the watersheds (0.87 - 1.69 ng/L) but river THg concentrations were highly variable. The Provo River showed the highest THg concentrations approaching 6 ng/L during peak flows, whereas maximum THg concentrations in the Logan River were <2 ng/L. Little Cottonwood Creek showed intermediate THg concentrations. THg and DOC showed strong positive correlation in the Provo River (R2=0.68) but were not correlated in the Logan River (R2=0.04). Notably, the Provo River showed the highest fraction of "dissolved" THg (calculated as the fraction of filtered/unfiltered concentration) averaging 75% compared with the other sites where the "dissolved" fraction was <45%. These results suggest that the majority of THg is transported in association with DOC in the Provo River but is more strongly associated with suspended sediments in the Logan River and Little Cottonwood Creek. These findings have implications for understanding Hg cycling in the Provo River watershed where Jordanelle Reservoir has fish consumption advisories due elevated Hg concentrations. The dissolved load of THg, possibly associated with DOC, is likely methylated in Jordanelle Reservoir where it bio-accumulates up the food web.

  8. Appendix E: Research papers. Manual versus digital LANDSAT analysis for modeling river flooding. [Black River, New York

    Science.gov (United States)

    Philipson, W. R. (Principal Investigator); Hafker, W. R.

    1980-01-01

    The comparative value of manual versus digital image analysis for determining flood boundaries is being examined in a study of the use of LANDSAT data for modeling flooding of the Black River, in northern New York. The work is an extension of an earlier study in which Black River flooding was assessed through visually interpreted, multi-date LANDSAT band 7 images. Based on the results to date, it appears that neither color-additive viewing nor digital analysis of LANDSAT data provide improvement in accuracy over visual analysis of band 7 images, for delineating the boundaries of flood-affected areas.

  9. Aerosol pollution over Northern India and Bangladesh

    Science.gov (United States)

    2002-01-01

    The skies over Northern India are filled with a thick soup of aerosol particles all along the southern edge of the Himalayan Mountains, and streaming southward over Bangladesh and the Bay of Bengal. Notice that the air over the Tibetan Plateau to the north of the Himalayas is very clear, whereas the view of the land surface south of the mountains is obstructed by the brownish haze. Most of this air pollution comes from human activities. The aerosol over this region is notoriously rich in sulfates, nitrates, organic and black carbon, and fly ash. These particles not only represent a health hazard to those people living in the region, but scientists have also recently found that they can have a significant impact on the region's hydrological cycle and climate (click to read the relevant NASA press release). This true-color image was acquired on December 4, 2001, by the Moderate-resolution Imaging Spectroradiometer (MODIS), flying aboard NASA's Terra satellite. It is interesting to compare the image above with this earlier MODIS image over the region, acquired on October 23, 2001. Notice the difference in the clarity of the air over the region in the earlier image. Under the thick plume of aerosol, the Brahmaputra (upper right) and Ganges Rivers are still visible. The many mouths of the Ganges have turned the northern waters of the Bay of Bengal a murky brown as they empty their sediment-laden waters into the bay. Toward the upper lefthand corner of the image, there appears to be a fresh swath of snow on the ground just south of the Himalayas.

  10. Processes controlling the chromium isotopic composition of river water: Constraints from basaltic river catchments

    Science.gov (United States)

    D'Arcy, Joan; Babechuk, Michael G.; Døssing, Lasse Nørbye; Gaucher, Claudio; Frei, Robert

    2016-08-01

    We report chromium (Cr) isotope compositions and concentrations (and additional geochemical and physicochemical data) of bedrock, soils and river waters from two geographically distinct basaltic river catchments, the Uruguay River catchment (Uruguay) and the Glenariff River catchment (Northern Ireland, United Kingdom), to investigate the processes that control Cr mobilisation and fractionation during weathering and riverine transport to the sea. Our results show that the Cr isotope compositions of soils are a function of the modal abundance and weathering rates of Cr-bearing minerals. The accumulation of weathering resistant Cr-spinels in the soils of Northern Ireland results in soils which are enriched in Cr and have δ53Cr values within the range of local bedrock (δ53Cr value of -0.21 ± 0.12‰, 2σ, n = 4). By contrast, the more easily weathered Cr-silicates in the bedrock of Uruguay results in greater Cr loss from the soil and a depletion in the heavy isotopes of Cr (with average δ53Cr value of -0.32 ± 0.04‰, 2σ, n = 4) relative to the local bedrock (δ53Cr value of -0.22 ± 0.08‰, 2σ, n = 4). The river waters in both catchments are predominantly enriched in the heavy 53Cr isotope relative to bedrock, although the range and average river water δ53Cr values differ significantly between each. The Uruguay rivers exhibit a restricted range in δ53Cr values, with a mean of +0.08 ± 0.06‰ (2σ, n = 5) that represents a positive fractionation of +0.2‰ relative to bedrock, and is best explained by the unidirectional formation of Cr(VI) during weathering that has not been significantly modified by back-reduction to Cr(III). By contrast, the Glenariff stream and river waters (Northern Ireland) exhibit a wide range in δ53Cr values from -0.17 ± 0.3‰ (2σ, n = 4) to +1.68 ± 0.3‰ (n = 1) that appears to reflect the variable redox conditions of the catchment. In general, the values with the lowest 53Cr enrichment have higher Cr concentrations, the lowest

  11. Wild and scenic river reports: Alagnak River

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Alagnak and its major tributary the Novianuk River and their immediate surroundings possess the qualities necessary for inclusion in the National Wild and Scenic...

  12. Northern Fur Seal Food Habits

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains food habits samples, usually scats, collected opportunistically on northern fur seal rookeries and haulouts in Alaska from 1987 to present....

  13. Flight tracks, Northern California TRACON

    Data.gov (United States)

    National Aeronautics and Space Administration — This dataset contains the records of all the flights in the Northern California TRACON. The data was provided by the aircraft noise abatement office...

  14. Comparison of planform multi-channel network characteristics of alluvial and bedrock constrained large rivers

    Science.gov (United States)

    Carling, P. A.; Meshkova, L.; Robinson, R. A.

    2011-12-01

    The Mekong River in northern Cambodia is an multi-channel mixed bedrock-alluvial river but it was poorly researched until present. Preliminary study of the Mekong geomorphology was conducted by gathering existing knowledge of its geological and tectonic settings, specific riparian vegetation and ancient alluvial terraces in which the river has incised since the Holocene. Altogether this process has allowed a geomorphological portrait of the river to be composed within the Quaternary context. Following this outline, the planform characteristics of the Mekong River network are compared, using analysis of channel network and islands configurations, with the fluvial patterns of the Orange River (South Africa), Upper Columbia River (Canada) and the Ganga River (India, Bangladesh). These rivers are selected as examples of multi-channel mixed bedrock alluvial, anastomosed alluvial and braided alluvial rivers respectively. Network parameters such as channel bifurcation angles asymmetry, sinuosity, braid intensity and island morphometric shape metrics are compared and contrasted between bedrock and alluvial systems. In addition, regional and local topographic trend surfaces produced for each river planform help explain the local changes in river direction and the degree of anastomosis, and distinguish the bedrock-alluvial rivers from the alluvial rivers. Variations between planform characteristics are to be explained by channel forming processes and in the case of mixed bedrock-alluvial rivers mediated by structural control. Channel metrics (derived at the reach-scale) provide some discrimination between different multi-channel patterns but are not always robust when considered singly. In contrast, island shape metrics (obtained at subreach-scale) allow robust discrimination between alluvial and bedrock systems.

  15. Water resource management in river oases along the Tarim River in North-West of China

    Science.gov (United States)

    Kliucininkaite, Lina; Disse, Markus

    2013-04-01

    Tarim River is one of the longest inland rivers in the world. It flows its water in the northern part of the Taklamakan desert in Xinjiang, North-west of China, which is a very hostile region due its climatic conditions and particularly due to low precipitation and very high evaporation rates. During the past five decades intensive exploitation of water resources, mainly by agricultural activities, has changed the temporal and spatial distribution of them and caused serious environmental problems in the Tarim River Basin. The support measures for oasis management along the Tarim River under climatic and societal changes became the overarching goal of this research. The temperature has risen by nearly 1° C over the past 50 years in the Tarim River Basin so more water was available in the mountainous areas of Xinjiang, leading to an increasing trend of the headstream discharges of the Tarim Basin. Aksu, Hotan and Yarkant Rivers are three tributaries of the Tarim River, as well as its main water suppliers. However, under the condition of water increase with the volume of 25×108 m3 in headstreams in recent 10 years, the water to the mainstream has increased less than 108 m3 (in Alar hydrological station), which is less than 3% of the increased water volume of runoff. Moreover, the region is one of the biggest cotton and other cash crops producers in China. In addition, expansion of urban and, in particular, of irrigation areas have caused higher water consumption at different parts of the river, leading to severe ecological effects on rural areas, especially in the lower reaches. Moreover, it also highly affects groundwater level and quality. The aim of this research is to support decision makers, planners and engineers to find right measures in the area for the further development of the region, as well as adaptation to changing climate. Different scenarios for water resource management, as well as water distribution and allocation in a more efficient and water

  16. Yellow River, Cradle of China

    Institute of Scientific and Technical Information of China (English)

    1995-01-01

    THE Yellow River is the Mother River of China. In the hearts of the Chinese people, it is not just an ancient river measuring 4,845 kilometers long that passes through nine provinces and regions, but also a symbol. The poets say that the waterway is the image of ancient China. Thephilosophers say the river is the shadow of a dragon. The river

  17. Active Tectonics Revealed by River Profiles along the Puqu Fault

    OpenAIRE

    Ping Lu,; Yu Shang

    2015-01-01

    The Puqu Fault is situated in Southern Tibet. It is influenced by the eastward extrusion of Northern Tibet and carries the clockwise rotation followed by the southward extrusion. Thus, the Puqu Fault is bounded by the principal dynamic zones and the tectonic evolution remains active alongside. This study intends to understand the tectonic activity in the Puqu Fault Region from the river profiles obtained from the remotely sensed satellite imagery. A medium resolution Digital Elevation Model (...

  18. Water Rights for Wetlands in the Bear River Delta

    OpenAIRE

    2016-01-01

    This fact sheet explains the basic premise and functioning of water rights in Utah and how water rights affect wetlands, specifically those in the northern region of the state. It includes the history of Utah water rights and the basic components of prior appropriation doctrine, and gives an example of using water rights for wetlands by explaining how the Bear River Migratory Bird Refuge works with neighboring water users to secure water for its wetlands.

  19. "Ghost river": The Columbia

    OpenAIRE

    Gayton, D.

    2001-01-01

    Metadata only record This perspective piece examines the history and geography of the Columbia River and some current ecosystem management issues related to hydroelectric development on the river. Once the greatest salmon producer in the word, the Columbia has, according to the author, become a "ghost river," with its salmon runs reduced to remnants, and its ecological integrity hanging in the balance. The author suggests that British Columbians have much to lose, both biologically and cul...

  20. Down to the River

    DEFF Research Database (Denmark)

    Wessels, Josepha Ivanka

    2015-01-01

    Currently there is no coherent or sustainable water cooperation among the five states—Israel, Jordan, Lebanon, Palestinian territories and Syria—that share the Jordan River. Why do people not cooperate on sustainable river basin management, even if it seems the most rational course from...... to illustrate hydropolitics in praxis, because the political future of this particular area in many respects affects the sustainable future of the Jordan River Basin and the entire Levant....

  1. Modelling the formation of dense water in the northern Adriatic: Sensitivity studies

    Science.gov (United States)

    Vilibić, Ivica; Mihanović, Hrvoje; Janeković, Ivica; Šepić, Jadranka

    2016-05-01

    This study aims to document the effects of imposing different river runoff forcing and tidal forcing to the dense water formation (DWF) rates and dynamics in a semi-enclosed sea. An extreme DWF episode that occurred in the winter of 2012 in the shallow northern Adriatic Sea during a prolonged cold bora wind outbreak event has been reproduced using a one-way coupled atmosphere-ocean modelling system comprised of the atmospheric Aladin/HR mesoscale model and ocean ROMS model. Three different river runoff forcing and tides/no tides scenarios were imposed on the model. The introduction of tides and river climatology instead of real rivers did not substantially change the modelled DWF transports and volumes, whereas the simulation using the old Raicich climatology resulted in a substantial freshening of the entire Adriatic that reduced or prevented the DWF at sites in the northern and northeastern Adriatic. The necessity of using an up-to-date river runoff climatology to properly reproduce the DWF in semi-enclosed seas is emphasised.

  2. Identifying water mass depletion in Northern Iraq observed by GRACE

    Directory of Open Access Journals (Sweden)

    G. Mulder

    2014-10-01

    Full Text Available Observations acquired by Gravity Recovery And Climate Experiment (GRACE mission indicate a mass loss of 31 ± 3 km3 or 130 ± 14 mm in Northern Iraq between 2007 and 2009. This data is used as an independent validation of a hydrologic model of the region including lake mass variations. We developed a rainfall–runoff model for five tributaries of the Tigris River, based on local geology and climate conditions. Model inputs are precipitation from Tropical Rainfall Measurement Mission (TRMM observations, and potential evaporation from GLDAS model parameters. Our model includes a representation of the karstified aquifers that cause large natural groundwater variations in this region. Observed river discharges were used to calibrate our model. In order to get the total mass variations, we corrected for lake mass variations derived from Moderate Resolution Imaging Spectroradiometer (MODIS in combination with satellite altimetry and some in-situ data. Our rainfall–runoff model confirms that Northern Iraq suffered a drought between 2007 and 2009 and is consistent with the mass loss observed by GRACE over that period. Also, GRACE observed the annual cycle predicted by the rainfall–runoff model. The total mass depletion seen by GRACE between 2007 and 2009 is mainly explained by a lake mass depletion of 74 ± 4 mm and a natural groundwater depletion of 37 ± 6 mm. Our findings indicate that man-made groundwater extraction has a minor influence in this region while depletion of lake mass and geology play a key role.

  3. Flood of April and May 2008 in Northern Maine

    Science.gov (United States)

    Lombard, Pamela J.

    2010-01-01

    Severe flooding occurred in Aroostook and Penobscot Counties in northern Maine between April 28 and May 1, 2008, and damage was extensive in the town of Fort Kent. Aroostook County was declared a Federal disaster area on May 9, and the declaration was expanded to include Penobscot County on May 16-qualifying the entire region for federal assistance. Water in the St. John River peaked at 30.17 feet in Fort Kent (5 feet above flood stage), hit the low steel of the International Bridge connecting Fort Kent to New Brunswick, caused closure of international bridges in Fort Kent, Van Buren, and Hamlin and came within inches of the top of a 30-foot-high earthen dike constructed to protect the downtown area of Fort Kent. Longterm streamgages with 25 to 84 years of record on the Big Black, St. John, Allagash, Fish, and Aroostook Rivers recorded maximum streamflows for their respective periods of record. Northern Maine experienced major floods in 1923, 1973, 1974, 1979, and 1983 (Maloney and Bartlett, 1991). All of these floods were in late April or early May when heavy rain combined with snowmelt runoff.

  4. FEATURES OF THE ALLUVIUM ON TANGXIAN SURFACE NEAR BAODE-FUGU AND ITS GEOMORPHOLOGIC IMPLICATIONS IN THE NORTHERN JINSHAAN GORGE, YELLOW RIVER%晋陕峡谷北段保德-府谷地区唐县面上冲积物的特征及其地貌意义

    Institute of Scientific and Technical Information of China (English)

    王小燕; 邱维理; 张家富; 李容全; 周力平

    2013-01-01

    Because of its complex history,the Yellow River is a good case for fluvial geomorphology studies.The Jinshaan Gorge is one of the key parts to understand the evolution of the Yellow River.Since 1922,researchers have made great progress in the study of the evolution of the Yellow River in the Jinshaan Gorge area.But there are some disputes still remained about the Tangxian Surface,an erosion surface formed in the Miocene and Pliocene,and the alluvium on it.The main divarication is whether the Tangxian Surface is a terrace of the Yellow River or the alluvium on the Tangxian Surface is formed by the ancient Yellow River.Baode-Fugu area,located in the north part of the Jinshaan Gorge,is famous for the Neogene red clay sediment in which Hipprion fauna is unearthed.The recent studies of red clay offer a chronological data to discuss the age of both the red clay,other contemporaneous sediment and the underneath erosion surface of Tangxian Stage.The present paper is based on the survey of eighteen sediment outcrops on the Tangxian Surface in the BaodeFugu area.Twenty one samples were collected from gravel layers for sediment analysis.A topographic profile across the Yellow River shows that there is a wide bedrock valley stretching along the modern Yellow River,which is about 170m above the river level.According to the previous magnetostratigraphic studies of the red clay and fluvial sediment,the Tangxian Surface was formed at least 8.OMa ago.Gravel statistic result shows that the gravel sitting on the Tangxian Surface is > 1.5 in the complexity index of components and is characterized by an average roundness of ca.2 or >2,i.e.sub-rounded and rounded,with a variance of >0.5.The rock type of the gravels indicates a mixture of distant and local source.Combining the evidences above,it is reasonable to conclude that there used to be a river flowing along a similar course direction of modern Yellow River in this region during the Middle Miocene.Though it is much smaller

  5. Investing in river health.

    Science.gov (United States)

    Bennett, J

    2002-01-01

    Rivers provide society with numerous returns. These relate to both the passive and extractive uses of the resources embodied in river environments. Some returns are manifest in the form of financial gains whilst others are non-monetary. For instance, rivers are a source of monetary income for those who harvest their fish. The water flowing in rivers is extracted for drinking and to water crops and livestock that in turn yield monetary profits. However, rivers are also the source of non-monetary values arising from biological diversity. People who use them for recreation (picnicking, swimming, boating) also receive non-monetary returns. The use of rivers to yield these returns has had negative consequences. With extraction for financial return has come diminished water quantity and quality. The result has been a diminished capacity of rivers to yield (non-extractive) environmental returns and to continue to provide extractive values. A river is like any other asset. With use, the value of an asset depreciates because its productivity declines. In order to maintain the productive capacity of their assets, managers put aside from their profits depreciation reserves that can be invested in the repair or replacement of those assets. Society now faces a situation in which its river assets have depreciated in terms of their capacity to provide monetary and non-monetary returns. An investment in river "repair" is required. But, investment means that society gives up something now in order to achieve some benefit in the future. Society thus has to grapple wih the choice between investing in river health and other investments--such as in hospitals, schools, defence etc. - as well as between investing in river health and current consumption--such as on clothes, food, cars etc. A commonly used aid for investment decision making in the public sector is benefit cost analysis. However, its usefulness in tackling the river investment problem is restricted because it requires all

  6. River Corridors (Jan 2, 2015)

    Data.gov (United States)

    Vermont Center for Geographic Information — River corridors are delineated to provide for the least erosive meandering and floodplain geometry toward which a river will evolve over time. River corridor maps...

  7. Hypoxia in the Northern Gulf of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Dale, Virginia H [ORNL

    2010-01-01

    Since 1985, scientists have been documenting a hypoxic zone in the Gulf of Mexico each year. The hypoxic zone, an area of low dissolved oxygen that cannot support marine life, generally manifests itself in the spring. Since marine species either die or flee the hypoxic zone, the spread of hypoxia reduces the available habitat for marine species, which are important for the ecosystem as well as commercial and recreational fishing in the Gulf. Since 2001, the hypoxic zone has averaged 16,500 km{sup 2} during its peak summer months, an area slightly larger than the state of Connecticut, and ranged from a low of 8,500 km{sup 2} to a high of 22,000 km{sup 2}. To address the hypoxia problem, the Mississippi River/Gulf of Mexico Watershed Nutrient Task Force (or Task Force) was formed to bring together representatives from federal agencies, states, and tribes to consider options for responding to hypoxia. The Task Force asked the White House Office of Science and Technology Policy to conduct a scientific assessment of the causes and consequences of Gulf hypoxia through its Committee on Environment and Natural Resources (CENR). In 2000 the CENR completed An Integrated Assessment: Hypoxia in the Northern Gulf of Mexico (or Integrated Assessment), which formed the scientific basis for the Task Force's Action Plan for Reducing, Mitigating, and Controlling Hypoxia in the Northern Gulf of Mexico (Action Plan, 2001). In its Action Plan, the Task Force pledged to implement ten management actions and to assess progress every 5 years. This reassessment would address the nutrient load reductions achieved, the responses of the hypoxic zone and associated water quality and habitat conditions, and economic and social effects. The Task Force began its reassessment in 2005. In 2006 as part of the reassessment, USEPA's Office of Water, on behalf of the Task Force, requested that the U.S. Environmental Protection Agency (USEPA) Science Advisory Board (SAB) convene an independent

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

    Institute of Scientific and Technical Information of China (English)

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

    2007-01-01

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

  9. Modelling the impact of wind stress and river discharge on Danshuei River plume

    Science.gov (United States)

    Liu, W.-C.; Chen, W.-B.; Cheng, R.T.; Hsu, M.-H.

    2008-01-01

    A three-dimensional, time-dependent, baroclinic, hydrodynamic and salinity model, UnTRIM, was performed and applied to the Danshuei River estuarine system and adjacent coastal sea in northern Taiwan. The model forcing functions consist of tidal elevations along the open boundaries and freshwater inflows from the main stream and major tributaries in the Danshuei River estuarine system. The bottom friction coefficient was adjusted to achieve model calibration and verification in model simulations of barotropic and baroclinic flows. The turbulent diffusivities were ascertained through comparison of simulated salinity time series with observations. The model simulation results are in qualitative agreement with the available field data. The validated model was then used to investigate the influence of wind stress and freshwater discharge on Dasnhuei River plume. As the absence of wind stress, the anticyclonic circulation is prevailed along the north to west coast. The model results reveal when winds are downwelling-favorable, the surface low-salinity waters are flushed out and move to southwest coast. Conversely, large amounts of low-salinity water flushed out the Danshuei River mouth during upwelling-favorable winds, as the buoyancy-driven circulation is reversed. Wind stress and freshwater discharge are shown to control the plume structure. ?? 2007 Elsevier Inc. All rights reserved.

  10. THE BEAR RIVER LANDSLIDE COMPLEX, PRESTON, IDAHO: GEOLOGIC CONSIDERATIONS AND HISTORICAL PERSPECTIVES

    OpenAIRE

    McCalpin, James P.

    1987-01-01

    The Bear River Landslide Complex is a series of earth movements in northern Cache Valley, north of Preston, Idaho. The landslides occur in unconsolidated sediments of the Pleistocene Bear River Delta which formed where the river entered Lakes Bonneville and Provo. The Lake Bonneville delta deposits are up to 490 feet (150 m) thick and consist of a lower alluvial coarse sand and gravel unit, a middle delta front fine sand and silt unit, and an upper pro-delta clay up to 50 feet (15 m) thick. T...

  11. Climate Change Impact Assessment of Dike Safety and Flood Risk in the Vidaa River System

    DEFF Research Database (Denmark)

    Madsen, H.; Sunyer Pinya, Maria Antonia; Larsen, J.;

    2013-01-01

    The impact of climate change on the flood risk and dike safety in the Vidaa River system, a cross-border catchment located in the southern part of Jutland, Denmark and northern Germany, is analysed. The river discharges to the Wadden Sea through a tidal sluice, and extreme water level conditions......, and increases in storm surge levels of up to 0.8 m in 2100 are estimated. The changes in extreme catchment run-off and sea water level have a significant effect on the flood risk in the river system. While most parts today have a low risk of dike overtopping with annual exceedance probabilities of 0.1 % or less...

  12. Historical Trends in Lake and River Ice Cover in Norway : signs of a changing climate

    OpenAIRE

    Solvang, Tord

    2013-01-01

    Recent studies have shown that the duration of seasonal ice cover on lakes and rivers over the Northern Hemisphere has declined over the 19th and 20th Centuries, mainly as a consequence of rising temperatures. However, lake and river ice trends have not been well documented in Norway. Quality control and homogeneity testing were performed on ice cover data from 48 Norwegian lake and river sites with long records. A total of 142 individual records of ice phenology (freeze-up, break-up and ice ...

  13. Traditional Jewelry on Both Sides of the Danube River

    Directory of Open Access Journals (Sweden)

    P. Chaushev

    2015-09-01

    Full Text Available From the Ancient times Danube River acts as stabile and almost uncontested Northern border of Bulgarian lands. For a very long period it divides different populations speaking different languages, developing different cultures and political units. In the same times Danube River unites it is both banks by cheap and easy to manage transportation. More than this Danube as a liquid border connects populations from the both banks with Central Europe serving as a vehicle for people, goods, money and ideas. The aim of this article is to explore one particular segment of culture connections - the evolution of traditional jewelry from 19th to early 20th century in the region of Northern Bulgaria and Southern Romania. The focus is on snake or dragon motifs carved on belt buckles originated from both sides of the border. This and related believes and cult practices reveals close cultural and commercial ties crossing Danube River. During my research I came across material that showed that those motifs were found in several Balkan countries (Serbia and Greece. The decoration of this traditional jewelry is typical for the Orient, but it is common among the Christian population of the Balkan Peninsula. It shows that in those times the Danube River was acting mostly as natural, not as a political or cultural border.

  14. Lower Flathead River Fisheries Study, 1983 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    DosSantos, Joseph M.; Darling, James E.; Cross, Paul D.

    1986-07-01

    In January of 1983 a two-phase study of the lower Flathead River was initiated by the Confederated Salish and Kootenai Tribes with funding provided by the Bonneville Power Administration. The study fulfills program measure 804 (a) (3) of the Columbia River Basin Fish and Wildlife Program. During 1983 Phase I of the study was completed resulting in a detailed study plan for the next four years and the methods to be employed during the study. Preliminary observations suggest the present operation of Kerr hydroelectric facility and land use practices within the drainage have combined to significantly reduce spawning success of salmonids and northern pike, and thus recruitment to the fisheries of the main river and tributaries. Main river spawning marshes were observed to be drained frequently during the northern pike spawning season which would result in desiccation of eggs and loss of attached fry. Water level fluctuations also caused trapping of juvenile fish and may be an important source of juvenile mortality.

  15. DETERMINATION OF CHARACTERISTICS MAXIMAL RUNOFF MOUNTAIN RIVERS IN CRIMEA

    Directory of Open Access Journals (Sweden)

    V. A. Ovcharuk

    2016-05-01

    Full Text Available This article has been examined maximum runoff of the rivers of theCrimeanMountains. The rivers flow through the western and eastern part of the northern slope Crimean Mountains, and on its southern coast. The largest of them: Belbek, Alma, Salgir, Su-Indol and others. To characterize the maximum runoff of rain floods (the layers of rain floods and maximum discharge of water on the rivers of the Crimean Mountains were used materials of observations for long-term period (from the beginning of observations to 2010 inclusive on 54 of streamflow station with using a the so-called «operator» model for maximum runoff formation.

  16. Coastal change and hypoxia in the northern Gulf of Mexico: Part I

    Directory of Open Access Journals (Sweden)

    2007-01-01

    Full Text Available The Committee on Environment and Natural Resources (CENR has identified the input of nutrient-rich water from the Mississippi/Atchafalaya River Basin (MARB as the prime cause of hypoxia in the northern Gulf of Mexico and the prime means for its control. A Watershed Nutrient Task Force was formed to solve the hypoxia problem by managing the MARB catchment. However, the hypoxic zone is also experiencing massive physical, hydrological, chemical and biological changes associated with an immense river-switching and delta-building event that occurs here about once a millennium. Coastal change induced hypoxia in the northern Gulf of Mexico prior to European settlement. It is recommended that for further understanding and control of Gulf hypoxia the Watershed Nutrient Task Force adopt a truly holistic environmental approach which includes the full effects of this highly dynamic coastal area.

  17. Modelling river dune development

    NARCIS (Netherlands)

    Paarlberg, Andries; Weerts, H.J.T.; Dohmen-Janssen, Catarine M.; Ritsema, I.L; Hulscher, Suzanne J.M.H.; van Os, A.G.; Termes, A.P.P.

    2005-01-01

    Since river dunes influence flow resistance, predictions of dune dimensions are required to make accurate water level predictions. A model approach to simulate developing river dunes is presented. The model is set-up to be appropriate, i.e. as simple as possible, but with sufficient accuracy for

  18. Tidal river dynamics

    NARCIS (Netherlands)

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

    2016-01-01

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

  19. Reining the River

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

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

  20. Shamanistic practice in Northern Nepal

    Directory of Open Access Journals (Sweden)

    Toni Schmid

    1967-01-01

    Full Text Available The Sherpas—in Tibetan śar-pa or "men of the east"—live mainly in Northern Nepal, in the Darjeeling district, in India and Northern Sikkim, in the regions bordering on Tibet, and on the southern slopes of the Himalayas. The Sherpas are of Tibetan stock. Among the Tibetan racial groups two religions can be broadly distinguished. One is a form of Buddhism, usually called Lamaism. The other religion is called in the Lhasa pronunciation Bon. Among the Sherpas both the religion and its priests are called "bombo", spelt: bongo.

  1. Genetic diversity of riperian populations of glycyrrhiza lepidota along the salmon and snake rivers

    Science.gov (United States)

    Glycyrrhiza lepidota Pursh (Fabaceae; American wild licorice), is a nitrogen-fixing, perennial, facultative riparian species present along many dryland rivers in western North America, including the U.S., southern Canada and northern Mexico. Like Glycyrrhiza glabra, common licorice native to Europe,...

  2. Satellite-based empirical models linking river plume dynamics with hypoxic area andvolume

    Science.gov (United States)

    Satellite-based empirical models explaining hypoxic area and volume variation were developed for the seasonally hypoxic (O2 < 2 mg L−1) northern Gulf of Mexico adjacent to the Mississippi River. Annual variations in midsummer hypoxic area and ...

  3. Sand spit and shoreline dynamics near Terekhol river mouth, Goa, India

    Digital Repository Service at National Institute of Oceanography (India)

    Rajasekaran, C.; Jayakumar, S.; Gowthaman, R.; Jishad, M.; Yadhunath, E.M.; Pednekar, P.S.

    between the sediment discharge from the river and the littoral transport Around 2km stretch of shoreline is under severe erosion in which a stretch of 500m of sea wall is completely damaged Sand spit present in the northern part of the shoreline plays a...

  4. Agriculture in the Mississippi River Basin; effects on water quality, aquatic biota, and watershed conservation.

    Science.gov (United States)

    Agriculture has been identified as a potential leading source of nutrients (nitrogen and phosphorus) and sediment enrichment of water bodies within the Mississippi River basin (MRB) and contributes to impaired water quality and biological resources in the MRB and the northern Gulf of Mexico (GOM). T...

  5. An Ecologic Characterization and Landscape Assessment of the Humboldt River Basin

    Science.gov (United States)

    The Humboldt River Basin covers a large part of northern Nevada. Very little is known about the water quality of the entire Basin. The people living in this area depend on clean water. Not knowing about water quality is a concern because people will need to manage the negative...

  6. Dreamy Draw Dam - Master Plan and Feature Design, New River and Phoenix City Streams, Arizona.

    Science.gov (United States)

    1981-09-01

    and New and Apr. 1983 Agua Fria River below the Arizona Canal Diversion Channel Part 5 - Arizona Canal Diversion Dec. 1983 Channel (including Cave...basin and can be tapped for potable water for recreation use. Electric lines are located approximately 2 miles from the basin at 19th Street and Northern

  7. Icy rivers heating up : Modelling hydrological impacts of climate change in the (sub)arctic

    NARCIS (Netherlands)

    Linden, Sandra van der

    2003-01-01

    The Arctic is considered to be particularly sensitive to global climate change. Global warming will seriously affect the components of the water balance in northern regions and changes in precipitation and temperature have immediate as well as long term effects on river systems. The main goal of thi

  8. Developing Permanent Vegetable Production Systems for the Red River Delta, Vietnam

    NARCIS (Netherlands)

    Pham Thi Thu Huong, Huong; Everaarts, A.P.; Neeteson, J.J.; Struik, P.C.

    2012-01-01

    The year-round demand for commercially produced vegetables in South-East Asia is growing rapidly because of ongoing population growth and urbanisation. Vegetable production plays an important role in the rural economy of the Red River Delta, the economic centre of northern Vietnam. Field vegetables,

  9. Development of a System Wide Predator Control Program: Stepwise Implementation of a Predation Index, Predator Control Fisheries, and Evaluation Plan in the Columbia River Basin; Section II: Evaluation; 1996 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Young, Franklin R.

    1997-11-01

    Predator control fisheries aimed at reducing predation on juvenile salmonids by northern squawfish (Ptychocheilus oregonensis) were implemented for the seventh consecutive year in the mainstream Columbia and Snake rivers.

  10. Termite assemblages in five semideciduous Atlantic Forest fragments in the northern coastland limit of the biome

    Directory of Open Access Journals (Sweden)

    Heitor Bruno de Araújo Souza

    2012-03-01

    Full Text Available Termites are abundant organisms in tropical ecosystems and strongly influence the litter decomposition and soil formation. Despite their importance, few studies about their assemblage structures have been made in Brazilian Atlantic Forest fragments, especially in the area located north of the São Francisco River. This study aims to analyze the assemblage composition of five Atlantic Forest fragments located in the northern biome limit along the Brazilian coast. A standardized sampling protocol of termites was applied in each fragment. Thirty-three termite species belonging to twenty genera and three families were found in the forest fragments. The wood-feeder group was dominant both concerning to species richness and number of encounters in all areas. In sites northern to 7°S, there is an evident simplification of the termite assemblage composition regarding species richness and number of encounters by feeding group. This fact is apparently due to a higher sandy level in soils and to semideciduous character of the vegetation in the northern fragments. Thus, even on the north of São Francisco River, termite biodiversity is heterogeneously spread with highest density of species in the portion between 07°S and São Francisco River mouth (10°29'S.

  11. Creating a catchment scale perspective for river restoration

    Science.gov (United States)

    Benda, L.; Miller, D.; Barquín, J.

    2011-09-01

    One of the major challenges in river restoration is to identify the natural fluvial landscape in catchments with a long history of river control. Intensive land use on valley floors often predates the earliest remote sensing: levees, dikes, dams, and other structures alter valley-floor morphology, river channels and flow regimes. Consequently, morphological patterns indicative of the fluvial landscape including multiple channels, extensive floodplains, wetlands, and fluvial-riparian and tributary-confluence dynamics can be obscured, and information to develop appropriate and cost effective river restoration strategies can be unavailable. This is the case in the Pas River catchment in northern Spain (650 km2), in which land use and development have obscured the natural fluvial landscape in many parts of the basin. To address this issue we used computer tools to examine the spatial patterns of fluvial landscapes that are associated with five domains of hydro-geomorphic processes and landforms. Using a 5-m digital elevation model, valley-floor surfaces were mapped according to elevation above the channel and proximity to key geomorphic processes. The predicted fluvial landscape is patchily distributed according to hillslope and valley topography, river network structure, and channel elevation profiles. The vast majority of the fluvial landscape in the main segments of the Pas River catchment is presently masked by human infrastructure, with only 15% not impacted by river control structures and development. The reconstructed fluvial landscape provides a catchment scale context to support restoration planning, in which areas of potential ecological productivity and diversity could be targeted for in-channel, floodplain and riparian restoration projects.

  12. Creating a catchment scale perspective for river restoration

    Directory of Open Access Journals (Sweden)

    L. Benda

    2011-09-01

    Full Text Available One of the major challenges in river restoration is to identify the natural fluvial landscape in catchments with a long history of river control. Intensive land use on valley floors often predates the earliest remote sensing: levees, dikes, dams, and other structures alter valley-floor morphology, river channels and flow regimes. Consequently, morphological patterns indicative of the fluvial landscape including multiple channels, extensive floodplains, wetlands, and fluvial-riparian and tributary-confluence dynamics can be obscured, and information to develop appropriate and cost effective river restoration strategies can be unavailable. This is the case in the Pas River catchment in northern Spain (650 km2, in which land use and development have obscured the natural fluvial landscape in many parts of the basin. To address this issue we used computer tools to examine the spatial patterns of fluvial landscapes that are associated with five domains of hydro-geomorphic processes and landforms. Using a 5-m digital elevation model, valley-floor surfaces were mapped according to elevation above the channel and proximity to key geomorphic processes. The predicted fluvial landscape is patchily distributed according to hillslope and valley topography, river network structure, and channel elevation profiles. The vast majority of the fluvial landscape in the main segments of the Pas River catchment is presently masked by human infrastructure, with only 15% not impacted by river control structures and development. The reconstructed fluvial landscape provides a catchment scale context to support restoration planning, in which areas of potential ecological productivity and diversity could be targeted for in-channel, floodplain and riparian restoration projects.

  13. Sediment characteristics and transportation dynamics of the Ganga River

    Science.gov (United States)

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

    2007-04-01

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

  14. Bioavailability and radiocarbon age of fluvial dissolved organic matter (DOM) from a northern peatland-dominated catchment: effect of land-use change

    DEFF Research Database (Denmark)

    Hulatt, C.J.; Kaartokallio, H.; Asmala, E.

    2014-01-01

    The radiocarbon age and biodegradability of dissolved organic matter (DOM) from a northern peat-dominated river system was studied and the effects of land-use were compared. Samples were obtained from streams and ditches comprising sub-catchments of the Kiiminki River, Northern Finland. Sample...... sites included areas of natural mire, areas subjected to moderate disturbance (ditching to enhance forestry), and areas subjected to serious land use change (agriculture and peat excavation). The study employed a 55 day bioassay that measured the biodegradation potential of surface-water DOM. We...

  15. Large barchanoid dunes in the Amazon River and the rock record: Implications for interpreting large river systems

    Science.gov (United States)

    Almeida, Renato Paes de; Galeazzi, Cristiano Padalino; Freitas, Bernardo Tavares; Janikian, Liliane; Ianniruberto, Marco; Marconato, André

    2016-11-01

    The interpretation of large river deposits from the rock record is hampered by the scarcity of direct observations of active large river systems. That is particularly true for deep-channel environments, where tens of meters deep flows dominate. These conditions are extremely different from what is found in smaller systems, from which current facies models were derived. MBES and shallow seismic surveys in a selected area of the Upper Amazonas River in Northern Brazil revealed the presence of large compound barchanoid dunes along the channel thalweg. The dunes are characterized by V-shaped, concave-downstream crest lines and convex-up longitudinal profiles, hundreds of meters wide, up to 300 m in wavelength and several meters high. Based on the morphology of compound dunes, expected preserved sedimentary structures are broad, large-scale, low-angle, concave up and downstream cross-strata, passing laterally and downstream to inclined cosets. Examples of such structures from large river deposits in the rock record are described in the Silurian Serra Grande Group and the Cretaceous São Sebastião and Marizal formations in Northeastern Brazil, as well as in Triassic Hawkesburry Sandstone in Southeastern Australia and the Plio-Pleistocene Içá Formation in the western Amazon. All these sedimentary structures are found near channel base surfaces and are somewhat coarser than the overlying fluvial deposits, favoring the interpretation of thalweg depositional settings. The recognition of large barchanoid dunes as bedforms restricted to river thalwegs and probably to large river systems brings the possibility of establishing new criteria for the interpretation of fluvial system scale in the rock record. Sedimentary structures compatible with the morphological characteristics of these bedforms seem to be relatively common in large river deposits, given their initial recognition in five different fluvial successions in Brazil and Australia, potentially enabling substantial

  16. A Journey To Northern Europe

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    <正>A tourism promotion launched by Northern European countries was held in Shanghai on February 24. Representatives from the tourism authorities in Denmark, Norway and Sweden introduced their special tourism resources to their Chinese counterparts, expressing their strong desire to expand tourism business in the Chinese market.According to the memorandum of understanding signed

  17. Qualidade das águas superficiais e avaliação do estado trófico do Rio Arari (Ilha de Marajó, norte do Brasil Surface water's quality and trophic status assessment in the Arari River (Marajo Island, Northern Brazil

    Directory of Open Access Journals (Sweden)

    Igor Charles Castor Alves

    2012-03-01

    Full Text Available A deterioração da qualidade da água pode ser causada tanto por resultado da pressão antrópica sobre os ambientes aquáticos em maiores escalas, como por fatores naturais em menores escalas, tal como ocorre em parte da bacia hidrográfica do Rio Arari (Ilha de Marajó, Pará. Este artigo teve como objetivo a avaliação da qualidade das águas superficiais e o estado trófico do Rio Arari, no trecho entre Santana e Cachoeira do Arari, considerando as variações temporais e espaciais de variáveis físicas, químicas e biológicas da água em dois períodos hidrológicos distintos de 2009: descarga máxima (abril e maio e descarga mínima (setembro e novembro. Os Índices de Qualidade da Água (IQA e Estado Trófico (IET foram determinados simultaneamente em amostras de água superficial durante 12 horas consecutivas nas três estações de coleta ao longo do Rio Arari. Os valores do IQA variaram entre "Ruim" e "Regular", e estão provavelmente relacionadas aos elevados níveis de coliformes fecais, baixas concentrações de oxigênio dissolvido e pH ácido do Rio Arari. Conforme o IET, o rio pode ser classificado como supereutrófico e hipereutrófico, reflexo da grande disponibilidade de nutrientes (e.g. fósforo e elevada biomassa fitoplanctônica em termos de clorofila a. O Rio Arari está sob um processo de eutrofização natural, visto que as fontes de contaminação antrópica ainda são incipientes, mas elas podem contribuir para um processo de longo prazo de eutrofização artificial.The deterioration of the water quality may be caused either by the result of human pressure on aquatic environments in larger scales, or by natural factors in smaller scales, such as part of the Arari River basin (Marajó Island, Pará state, Brazil .This work aimed to evaluate the surface water's quality and the trophic state of the Arari River, between Santana and Cachoeira do Arari localities, taking into account the seasonal and spatial variations

  18. Variations of hydrological characteristics at the rivers of different size in the Lena river basin

    Science.gov (United States)

    Semenova, Olga; Tananaev, Nikita; Lebedeva, Luidmila; Popova, Evdokiya

    2016-04-01

    There are many speculations about possible impact of climate change at hydrological regime of Northern Eurasia, and permafrost basins in particular. Though the changes of flow of large rivers are relatively well described, the trends for small and middle-size watersheds are unknown. After the papers by Shiklomanov et al. (2007) and Smith et al. (2007) examining the variations of maximum and minimum flow in Northern Russia by 2001 there was no much update in this issue. In this study we compiled the database of continuous daily runoff for about 110 gauges within the Lena River basin with the order of basin area from 10 to 100000 sq.km. All currently functioning flow gauges with continuous observations not less than 35 years were selected for the database which contains the data up to 2013. For chosen gauges the parameters of row-correlation, cyclic recurrence and the stationarity of main runoff characteristics (mean, maximum and minimum flow) were estimated. The conclusions are drawn about the evidence of unsteadiness and/or internal correlation in runoff series; the robust indicators of the intensity of detected changes are evaluated; the duration of water cycles and evaluation the spatial correlation between water cycles are explored. The study is supported by Russian Foundation for Basic Research (project 15-35-21146 mol_a).

  19. Using Remote Sensing Data to Parameterize Ice Jam Modeling for a Northern Inland Delta

    Directory of Open Access Journals (Sweden)

    Fan Zhang

    2017-04-01

    Full Text Available The Slave River is a northern river in Canada, with ice being an important component of its flow regime for at least half of the year. During the spring breakup period, ice jams and ice-jam flooding can occur in the Slave River Delta, which is of benefit for the replenishment of moisture and sediment required to maintain the ecological integrity of the delta. To better understand the ice jam processes that lead to flooding, as well as the replenishment of the delta, the one-dimensional hydraulic river ice model RIVICE was implemented to simulate and explore ice jam formation in the Slave River Delta. Incoming ice volume, a crucial input parameter for RIVICE, was determined by the novel approach of using MODIS space-born remote sensing imagery. Space-borne and air-borne remote sensing data were used to parameterize the upstream ice volume available for ice jamming. Gauged data was used to complement modeling calibration and validation. HEC-RAS, another one-dimensional hydrodynamic model, was used to determine ice volumes required for equilibrium jams and the upper limit of ice volume that a jam can sustain, as well as being used as a threshold for the volumes estimated by the dynamic ice jam simulations using RIVICE. Parameter sensitivity analysis shows that morphological and hydraulic properties have great impacts on the ice jam length and water depth in the Slave River Delta.

  20. Hydrochemistry (major and trace elements of Lake Malawi (Nyasa, Tanzanian Northern Basin: local versus global considerations

    Directory of Open Access Journals (Sweden)

    P. Branchu

    2010-07-01

    Full Text Available This paper presents the first inventory of dissolved minor and trace element (F, Al, Fe, Mn, Ba, Cd, Cr, Cu, Pb, Mo, Bi, Sr, Zn concentrations in Lake Malawi, the second largest African lake. Sampling was carried out during 1993 dry season in the northern part of the lake. Trace metal concentrations were measured, together with Ca, Mg, Na, K, Cl, SO4, Alkalinity and Si, along three profiles in the lake northern extremity, in five tributaries and two on-land hydrothermal springs. Water profiles show similar elemental distributions and concentrations that are influenced by lake physical-chemical stratification. Stratification, assessed using temperature, conductivity, Si and Mn profiles, is characterised by two boundaries: the thermocline (70–90 m and the oxicline (150–190 m. Elemental water concentrations are discussed using simple covariance analyse. Epilimnetic concentrations and distribution are also influenced by atmospheric deposition and river diving. Comparison of dissolved concentrations for potentially polluting elements with World Health Organisation Guidelines and those reported for other East African lakes shows that this reservoir is uncontaminated despite an increasing human stress. Major element behaviour is assessed through a 3 boxes model. In this model Cl and K are conservative elements whereas Si is removed from the solution by diatom productivity and sedimentation. Ca, Na, Mg and alkalinity show low reactivity. Evaporation is one of the controlling factors of lake element concentration that superimposes on the watershed control. Hydrothermal activity, not evidenced in the lake, controls the chemistry of one of the main northern tributary. Chemical comparison between Northern rivers and other tributaries characterises the geographical and geological specificity of studied northern watershed. Moreover the lake annual chemical budget shows that northern watershed generates the main elemental input to the lake

  1. Introduced northern pike predation on salmonids in southcentral Alaska

    Science.gov (United States)

    Sepulveda, Adam J.; Rutz, David S.; Ivey, Sam S.; Dunker, Kristine J.; Gross, Jackson A.

    2013-01-01

    Northern pike (Esox lucius) are opportunistic predators that can switch to alternative prey species after preferred prey have declined. This trophic adaptability allows invasive pike to have negative effects on aquatic food webs. In Southcentral Alaska, invasive pike are a substantial concern because they have spread to important spawning and rearing habitat for salmonids and are hypothesised to be responsible for recent salmonid declines. We described the relative importance of salmonids and other prey species to pike diets in the Deshka River and Alexander Creek in Southcentral Alaska. Salmonids were once abundant in both rivers, but they are now rare in Alexander Creek. In the Deshka River, we found that juvenile Chinook salmon (Oncorhynchus tshawytscha) and coho salmon (O. kisutch) dominated pike diets and that small pike consumed more of these salmonids than large pike. In Alexander Creek, pike diets reflected the distribution of spawning salmonids, which decrease with distance upstream. Although salmonids dominated pike diets in the lowest reach of the stream, Arctic lamprey (Lampetra camtschatica) and slimy sculpin (Cottus cognatus) dominated pike diets in the middle and upper reaches. In both rivers, pike density did not influence diet and pike consumed smaller prey items than predicted by their gape-width. Our data suggest that (1) juvenile salmonids are a dominant prey item for pike, (2) small pike are the primary consumers of juvenile salmonids and (3) pike consume other native fish species when juvenile salmonids are less abundant. Implications of this trophic adaptability are that invasive pike can continue to increase while driving multiple species to low abundance.

  2. Mackenzie River Delta, Canada

    Science.gov (United States)

    2007-01-01

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

  3. Wild and Scenic Rivers

    Data.gov (United States)

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

  4. Laminar laboratory rivers

    Science.gov (United States)

    Seizilles, Grégoire; Devauchelle, Olivier; Lajeunesse, Éric; Métivier, François

    2014-05-01

    A viscous fluid flowing over fine plastic grains spontaneously channelizes into a few centimeters-wide river. After reaching its equilibrium shape, this stable laboratory flume is able to carry a steady load of sediments, like many alluvial rivers. When the sediment discharge vanishes, the river size, shape and slope fit the threshold theory proposed by Glover and Florey (1951), which assumes that the Shields parameter is critical on the channel bed. As the sediment discharge is increased, the river widens and flattens. Surprisingly, the aspect ratio of its cross section depends on the sediment discharge only, regardless of the water discharge. We propose a theoretical interpretation of these findings based on the balance between gravity, which pulls particles towards the center of the channel, and the diffusion of bedload particles, which pushes them away from areas of intense bedload.

  5. Dulbi River goose survey

    Data.gov (United States)

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

  6. Skjern River Restoration Counterfactual

    DEFF Research Database (Denmark)

    Clemmensen, Thomas Juel

    2014-01-01

    In 2003 the Skjern River Restoration Project in Denmark was awarded the prestigious Europa Nostra Prize for ‘conserving the European cultural heritage’ (Danish Nature Agency 2005). In this case, however, it seems that the conservation of one cultural heritage came at the expense of another cultural...... of Dissonance in Nature Restoration’, Journal of Landscape Architecture 2/2014: 58-67. Danish Nature Agency (2005), Skjern Å: Ådalens historie. De store projekter. Det nye landskab og naturen. På tur i ådalen [The Skjern River: The History of the River Delta. The Big Projects. The New Landscape and Nature...... heritage. While the meanders of the Skjern River were reconstructed according to its assumed course in 1870s, the embanked canal, which was the main feature and symbol of a comprehensive cultivation project from the 1960s, was deconstructed and reduced to incomprehensible traces of the past. Not only did...

  7. The Carmans River Story

    Data.gov (United States)

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

  8. Russian River Analysis

    Data.gov (United States)

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

  9. Seismic risk assessment of Navarre (Northern Spain)

    Science.gov (United States)

    Gaspar-Escribano, J. M.; Rivas-Medina, A.; García Rodríguez, M. J.; Benito, B.; Tsige, M.; Martínez-Díaz, J. J.; Murphy, P.

    2009-04-01

    The RISNA project, financed by the Emergency Agency of Navarre (Northern Spain), aims at assessing the seismic risk of the entire region. The final goal of the project is the definition of emergency plans for future earthquakes. With this purpose, four main topics are covered: seismic hazard characterization, geotechnical classification, vulnerability assessment and damage estimation to structures and exposed population. A geographic information system is used to integrate, analyze and represent all information colleted in the different phases of the study. Expected ground motions on rock conditions with a 90% probability of non-exceedance in an exposure time of 50 years are determined following a Probabilistic Seismic Hazard Assessment (PSHA) methodology that includes a logic tree with different ground motion and source zoning models. As the region under study is located in the boundary between Spain and France, an effort is required to collect and homogenise seismological data from different national and regional agencies. A new homogenised seismic catalogue, merging data from Spanish, French, Catalonian and international agencies and establishing correlations between different magnitude scales, is developed. In addition, a new seismic zoning model focused on the study area is proposed. Results show that the highest ground motions on rock conditions are expected in the northeastern part of the region, decreasing southwards. Seismic hazard can be expressed as low-to-moderate. A geotechnical classification of the entire region is developed based on surface geology, available borehole data and morphotectonic constraints. Frequency-dependent amplification factors, consistent with code values, are proposed. The northern and southern parts of the region are characterized by stiff and soft soils respectively, being the softest soils located along river valleys. Seismic hazard maps including soil effects are obtained by applying these factors to the seismic hazard maps

  10. Synthetic River Valleys

    Science.gov (United States)

    Brown, R.; Pasternack, G. B.

    2011-12-01

    The description of fluvial form has evolved from anecdotal descriptions to artistic renderings to 2D plots of cross section or longitudinal profiles and more recently 3D digital models. Synthetic river valleys, artificial 3D topographic models of river topography, have a plethora of potential applications in fluvial geomorphology, and the earth sciences in general, as well as in computer science and ecology. Synthetic river channels have existed implicitly since approximately the 1970s and can be simulated from a variety of approaches spanning the artistic and numerical. An objective method of synthesizing 3D stream topography based on reach scale attributes would be valuable for sizing 3D flumes in the physical and numerical realms, as initial input topography for morphodynamic models, stream restoration design, historical reconstruction, and mechanistic testing of interactions of channel geometric elements. Quite simply - simulation of synthetic channel geometry of prescribed conditions can allow systematic evaluation of the dominant relationships between river flow and geometry. A new model, the control curve method, is presented that uses hierarchically scaled parametric curves in over-lapping 2D planes to create synthetic river valleys. The approach is able to simulate 3D stream geometry from paired 2D descriptions and can allow experimental insight into form-process relationships in addition to visualizing past measurements of channel form that are limited to two dimension descriptions. Results are presented that illustrate the models ability to simulate fluvial topography representative of real world rivers as well as how channel geometric elements can be adjusted. The testing of synthetic river valleys would open up a wealth of knowledge as to why some 3D attributes of river channels are more prevalent than others as well as bridging the gap between the 2D descriptions that have dominated fluvial geomorphology the past century and modern, more complete, 3D

  11. The impact of global warming on river runoff

    Science.gov (United States)

    Miller, James R.; Russell, Gary L.

    1992-01-01

    A global atmospheric model is used to calculate the annual river runoff for 33 of the world's major rivers for the present climate and for a doubled CO2 climate. The model has a horizontal resolution of 4 x 5 deg, but the runoff from each model grid box is quartered and added to the appropriate river drainage basin on a 2 x 2.5 deg resolution. The computed runoff depends on the model's precipitation, evapotranspiration, and soil moisture storage. For the doubled CO2 climate, the runoff increased for 25 of the 33 rivers, and in most cases the increases coincide with increased rainfall within the drainage basins. There were runoff increases in all rivers in high northern latitudes, with a maximum increase of 47 percent. At low latitudes there were both increases and decreases ranging from a 96 increase to a 43 percent decrease. The effect of the simplified model assumptions of land-atmosphere interactions on the results is discussed.

  12. Cytogenetic characterization of the strongly electric Amazonian eel, Electrophorus electricus (Teleostei, Gymnotiformes), from the Brazilian rivers Amazon and Araguaia

    OpenAIRE

    Fonteles,Soraia B.A.; Lopes,Carlos E.; Alberto Akama; FERNANDES, Flora M.C.; Fábio Porto-Foresti; José A. Senhorini; Maria de Fátima Z. Daniel-Silva; Fausto Foresti; Lurdes Foresti de Almeida-Toledo

    2008-01-01

    A karyotype analysis of the electric eel, Electrophorus electricus (Teleostei, Gymnotiformes), a strongly electric fish from northern South America, is presented. Two female specimens were analyzed, one from the Amazon River and one from the Araguaia River. The specimens had a chromosomal number of 2n = 52 (42M-SM + 10A). C-bands were present in a centromeric and pericentromeric position on part of the chromosomes; some interstitial C-bands were also present. Heteromorphic nucleolus organizer...

  13. Complex Drainage Response To Migrating Tectonic Uplift: Example From The Northern California Coast Ranges

    Science.gov (United States)

    Lock, J.; Furlong, K. P.

    Migration of the Mendocino triple junction in northern California produces rapid and dramatic changes in the processes and patterns of crustal deformation. In response to this tectonism, the river systems of the northern California Coast Ranges have devel- oped a complex drainage history and pattern. The tectonic response to this migrating triple junction is described by the Mendocino Crustal Conveyor model (MCC), which predicts a spatially and temporally varying pattern of crustal deformation and up- lift. We use a combination of geomorphic and geophysical observations, coupled with landscape evolution modeling to develop the links between the geomorphic observa- tions in the Coast Ranges and the uplift/subsidence pattern predicted by the MCC. In contrast to many previous landscape evolution studies that find that streams typically cut through or are diverted around growing structures, in the northern California Coast Ranges drainage reversal and stream capture appear to be the response to tectonism. Our landscape evolution modeling shows that the uplift predicted by the MCC pro- duces: (1) a topographic gradient that switches from trending northwest to southeast, causing streams that at first flow to the northwest to reverse and drain to the south- east, (2) drainage divides that migrate in concert with the triple junction, and (3) river evolution that will result in fish hooked drainage patterns, all characteristics similar to those observed in the Northern California Coast Ranges. The uplift/subsidence pat- tern in the northern Coast Ranges is further complicated by the interaction of a second tectonic driver - the Pioneer fragment. The Pioneer fragment migrates with the Pacific (south of the triple junction) and creates a mini-slab window, adjacent to the coast, to produce a superimposed secondary uplift/subsidence pattern. The effects of this Pioneer related uplift are recorded by the Eel River. Key to the complex evolution of river systems in northern

  14. Deep-water Fan Systems and Petroleum Resources on the Northern Slope of the South China Sea

    Institute of Scientific and Technical Information of China (English)

    PANG Xiong; YANG Shaokun; ZHU Ming; LI Jinsong

    2004-01-01

    The shallow shelf delta/strand arenaceous-pelitic deposit region in the north of the Pearl River mouth basin,sitting on the northern continental shelf of the South China Sea, has already become an important oil production base in China. Recent researched has revealed that a great deal of deep-water fans of great petroleum potentiality exist on the Baiyun deep-water slope below the big palco Pearl River and its large delta. Based on a mass of exploration wells and 2-D seismic data of the shallow shelf region, a interpretation of sequence stratigraphy confirmed the existence of deep-water fans. The cyclic falling of sea level, abundant detrital matter from the paleo Pearl River and the persistent geothermal subsidence in the Baiyun sag are the three prerequisites for the formation and development of deep-water fans. There are many in common between the deep-water shelf depositional system of the northern South China Sea and the exploration hotspots region on the two banks of the Atlantic. For example, both are located on passive continent margins, and persistent secular thermal subsidence and large palco rivers have supplied abundant material sources and organic matter.More recently, the discovery of the big gas pool on the northern slope of the Baiyun sag confirms that the Lower Tertiary lacustrine facies in the Baiyun sag has a great potentiality of source rocks. The fans overlying the Lower Tertiary source rocks should become the main exploration areas for oil and gas resources.

  15. Particulate organic carbon and nitrogen export from major Arctic rivers

    Science.gov (United States)

    McClelland, J. W.; Holmes, R. M.; Peterson, B. J.; Raymond, P. A.; Striegl, R. G.; Zhulidov, A. V.; Zimov, S. A.; Zimov, N.; Tank, S. E.; Spencer, R. G. M.; Staples, R.; Gurtovaya, T. Y.; Griffin, C. G.

    2016-05-01

    Northern rivers connect a land area of approximately 20.5 million km2 to the Arctic Ocean and surrounding seas. These rivers account for ~10% of global river discharge and transport massive quantities of dissolved and particulate materials that reflect watershed sources and impact biogeochemical cycling in the ocean. In this paper, multiyear data sets from a coordinated sampling program are used to characterize particulate organic carbon (POC) and particulate nitrogen (PN) export from the six largest rivers within the pan-Arctic watershed (Yenisey, Lena, Ob', Mackenzie, Yukon, Kolyma). Together, these rivers export an average of 3055 × 109 g of POC and 368 × 109 g of PN each year. Scaled up to the pan-Arctic watershed as a whole, fluvial export estimates increase to 5767 × 109 g and 695 × 109 g of POC and PN per year, respectively. POC export is substantially lower than dissolved organic carbon export by these rivers, whereas PN export is roughly equal to dissolved nitrogen export. Seasonal patterns in concentrations and source/composition indicators (C:N, δ13C, Δ14C, δ15N) are broadly similar among rivers, but distinct regional differences are also evident. For example, average radiocarbon ages of POC range from ~2000 (Ob') to ~5500 (Mackenzie) years before present. Rapid changes within the Arctic system as a consequence of global warming make it challenging to establish a contemporary baseline of fluvial export, but the results presented in this paper capture variability and quantify average conditions for nearly a decade at the beginning of the 21st century.

  16. Juvenile salmon usage of the Skeena River estuary.

    Science.gov (United States)

    Carr-Harris, Charmaine; Gottesfeld, Allen S; Moore, Jonathan W

    2015-01-01

    Migratory salmon transit estuary habitats on their way out to the ocean but this phase of their life cycle is more poorly understood than other phases. The estuaries of large river systems in particular may support many populations and several species of salmon that originate from throughout the upstream river. The Skeena River of British Columbia, Canada, is a large river system with high salmon population- and species-level diversity. The estuary of the Skeena River is under pressure from industrial development, with two gas liquefaction terminals and a potash loading facility in various stages of environmental review processes, providing motivation for understanding the usage of the estuary by juvenile salmon. We conducted a juvenile salmonid sampling program throughout the Skeena River estuary in 2007 and 2013 to investigate the spatial and temporal distribution of different species and populations of salmon. We captured six species of juvenile anadromous salmonids throughout the estuary in both years, and found that areas proposed for development support some of the highest abundances of some species of salmon. Specifically, the highest abundances of sockeye (both years), Chinook in 2007, and coho salmon in 2013 were captured in areas proposed for development. For example, juvenile sockeye salmon were 2-8 times more abundant in the proposed development areas. Genetic stock assignment demonstrated that the Chinook salmon and most of the sockeye salmon that were captured originated from throughout the Skeena watershed, while some sockeye salmon came from the Nass, Stikine, Southeast Alaska, and coastal systems on the northern and central coasts of British Columbia. These fish support extensive commercial, recreational, and First Nations fisheries throughout the Skeena River and beyond. Our results demonstrate that estuary habitats integrate species and population diversity of salmon, and that if proposed development negatively affects the salmon populations that

  17. New angiosperm genera from cretaceous sections of northern Asia

    Science.gov (United States)

    Alekseev, P. I.; Herman, A. B.; Shchepetov, S. V.

    2014-11-01

    The Cretaceous floras of northern Asia represented by the Antibes flora of the Chulym-Yenisei area of West Siberia, Kaivayam flora of northwestern Kamchatka, and Grebenka flora of the Anadyr River basin in Chukotka are reviewed. These floras characterize the Late Cretaceous Siberian-Canadian Paleofloristic Region, where they developed in humid warm temperate climatic environments. Two new angiosperm genera are described: genus Chachlovia P. Alekseev et Herman with species C. kiyensis P. Alekseev, sp. nov. and C. dombeyopsoida (Herman) Herman, comb. nov. and genus Soninia Herman et Shczepetov with species S. asiatica P. Alekseev, sp. nov. and S. integerrima Herman et Shczepetov, sp. nov. The species Chachlovia kiyensis and Soninia asiatica were characteristic components of the Antibes flora. Chachlovia dombeyopsoida and Soninia integerrima were constituents of the Kaivayam and Grebenka floras, respectively.

  18. Offshore northern Europe, the challenges

    Energy Technology Data Exchange (ETDEWEB)

    Bergseth, S. [Statoil, Stavenger (Norway)

    1996-12-31

    This paper relates to challenges of the offshore activity in the North Sea. It is appropriate to address these challenges in the context of generating values through efficient management of resources, markets, safety and technology, as the challenges lie therein. The petroleum industry is built to turn natural resources into market value, assuring broad benefits to stake holders and shareholders. In the following, the challenges facing the industry the industry offshore Northern Europe is examined on this background

  19. Mitigating Radicalism in Northern Nigeria

    Science.gov (United States)

    2013-08-01

    laborers and traders from the south settled into can- tonments in most major northern cities. The effect of these sabon gari (“strangers’ quarters” in...result of Peace Club programs. Adults from different ethnic groups now invite each other to child naming ceremonies, weddings, and funerals, which...conventions, establishing standards for charities, and increased international cooperation. In Bangladesh , the government works through the country’s

  20. 引汉济渭水权置换的管理制度创新研究%Study on Management System Innovation of Water Rights Replacement of Water Diversion from Hanjiang River to Weihe River

    Institute of Scientific and Technical Information of China (English)

    黄建水; 殷会娟; 乔钰

    2014-01-01

    Taking the Hanjiang River to the weihe River water rights as the object of study,through the exploratory analysis method,this paper solved the replacement of the Hanjiang River to the Weihe River water rights and the Yellow River water rights whether replacement of the theoreti-cal basis and the legal basis. The essence of the Hanjiang River to the Weihe River water rights replacement is increasing the total amount of water resources in the Yellow River after drawing water from the Hanjiang River to the Weihe River,increasing the area of the Yellow River water index though replacing the water index from the Weihe River water to northern area of Shaanxi Province. Through the innovation of the Yellow River water rights management system,it can realize the replacement of the Hanjiang River to the Weihe River water rights and the Yellow River water rights. The exchange management system of the Hanjiang River to the Weihe River water rights is not only the basis of increasing the Yellow River water consumption after guiding the Hanjiang River to the Weihe River water,but also is the implementation basis of replacement of water rights,and is the guiding regulation of replacing the two water rights as well.%以引汉济渭水权为研究对象,通过探索性分析方法解决了引汉济渭水权与黄河水权置换是否有理论依据和法律依据问题。引汉济渭水权置换的实质是从汉江流域调水补充渭河后使黄河水资源总量增加,把陕西省的渭河取水指标置换给陕北地区,增加该地区黄河取水指标。通过黄河水权管理制度的创新,可以实现引汉济渭水权与黄河水权的置换。引汉济渭水权置换管理制度既是引汉济渭后陕北地区增加黄河用水量的依据,又是两个水权实行置换的依据,也是两个水权实施置换的指导规范。

  1. Study on thermal infrared remote sensing of Yarlung Zangbo River and Bangong Co-Nujiang River suture belt in Qinghai-Tibet Plateau

    Institute of Scientific and Technical Information of China (English)

    BI Siwen; YAN Hao; WANG Changyao

    2006-01-01

    The area change of heat abnormity is not in accordance with conclusions of former thermal infrared remote sensing studies of the Qinghai-Tibet Plateau, which were that the temperature of Yarlung Zangbo River suture belt of the southern Plateau is high and the northern temperature is low. The study result in this paper shows that the highest temperature is found in the Bangong Co-Nujiang River suture belt, the Yarlung Zangbo River suture belt temperature is the second highest, and the northern Tibet temperature is the lowest. The study demonstration area was the suture belt areas of the Yarlung Zangbo River and the Bangong Co-Nujiang River in the Qinghai-Tibet Plateau, where the land temperature of the Qinghai-Tibet Plateau and the bore temperature of field land surface were measured and the emissivity of land surface was calculated. In addition, the authors explore the mechanism of the relationship between thermal infrared remote sensing and constructing thermodynamics and reach four new conclusions about the thermodynamics of the Tibet Plateau.

  2. The Mattole River Estuary: Restoration Efforts in a Dynamic System

    Science.gov (United States)

    Barber, D.; Liquori, M.

    2010-12-01

    Despite extensive scientific advancement integrating our understanding of hydrology, geomorphology, and ecology in recent decades, the application of restoration in the field has been slow to evolve. This presentation will highlight 20 years of restoration practices in the Mattole River Estuary and how these practices have informed our understanding of this complex system. The Mattole River Watershed is a 304 square-mile basin located near the Mendocino Triple Junction in a remote region of California known as the “The Lost Coast” for its rugged mountains and undeveloped coastline. In addition to numerous species of fish, mammals, and over 250 bird species, the Mattole Watershed is home to three Federally-listed Threatened salmonids: California Coastal Chinook salmon, Southern Oregon/Northern California Coasts coho salmon, and Northern California steelhead trout. The 64 mile-long river meets the Pacific Ocean at the northern end of the 64,000 acre King Range National Conservation Area (KRNCA), managed by the Bureau of Land Management (BLM). The watershed is dynamic, with some of the nation’s highest annual rainfall (mean = 158 cm/yr), naturally occurring steep slopes, erosive sedimentary geology, and frequent earthquakes. All of these factors have amplified the negative effects of extensive logging and associated road building between 1945 and 1970, which left a legacy of increased sediment loads and high water temperatures that have yet to recover to pre-disturbance levels, severely impairing riparian and aquatic habitats. Prior to major land disturbances, the Mattole estuary/lagoon was notable for its deep, thermally-stratified pools and numerous functioning north and south bank slough channels that flushed sediments from the river and received marine water. As flows decline in late spring, a sandbar closes off surface flow from the river to the Pacific Ocean, forming a lagoon, which persists until flows increase in the fall. Today, the estuary is poor

  3. Estimation of nutrient contributions from the ocean across a river basin using stable isotope analysis

    Directory of Open Access Journals (Sweden)

    K. Nakayama

    2015-04-01

    Full Text Available Since marine derived nutrients (MDN are transported not only in river channels but also across the entire river basin, including via ground water and migratory animals, it is necessary to investigate the contribution of MDN to the forest floor (soils in order to quantify the true role of MDN at the river ecosystem scale. This study investigated the contribution of pink (Oncorhynchus gorbuscha and chum salmon (O. keta to total oceanic nitrogen (TN input across a river basin using stable isotope analysis (SIA of nitrogen (δ15N. The contribution of TN entering the river basin by salmon was 23.8 % relative to the total amount of TN exported from the river basin, providing a first estimate of MDN export for a river basin. The contribution of nitrogen from the ocean to the river basin soils was between 22.9 and 23.8 %. Furthermore, SIA showed that the transport of oceanic TN by sea eagles (Haliaeetus spp. was greater than that by bears (Ursus arctos, which had previously been that bears are thought to be the major animal transporter of nutrients in the northern part of Japan.

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

    Data.gov (United States)

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

  5. Kisaralik River: A wild and scenic river analysis

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Kisaralik River from and including Kisaralik Lake to the west boundary of TSN, R65W meets the criteria established by the Wild and Scenic Rivers Act for...

  6. Assessment of climate change impact on river flow regimes in The Red River Delta, Vietnam – A case study of the Nhue-Day River Basin

    Directory of Open Access Journals (Sweden)

    Phan Cao Duong

    2016-09-01

    Full Text Available Global warming has caused dramatic changes in regional climate variability, particularly regarding fluctuations in temperature and rainfall. Thus, it is predicted that river flow regimes will be altered accordingly. The purpose of this paper is to present the results of modeling such changes by simulating discharge using the HEC-HMS model. The precipitation was projected using super-high resolution multiple climate models (20 km resolution with newly updated emission scenarios as the input for the HEC-HMS model for flow analysis at the Red River Basin in the northern area of Vietnam. The findings showed that climate change impact on the river flow regimes tend towards a decrease in the dry season and a longer duration of flood flow. A slight runoff reduction is simulated for November while a considerable runoff increase is modeled for July and August amounting to 30% and 25%, respectively. The discharge scenarios serve as a basis for water managers to develop suitable adaptation methods and responses on the river basin scale.

  7. Study on the Reutilization of River Sediment

    Institute of Scientific and Technical Information of China (English)

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

    2002-01-01

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

  8. Hypoxia Adjacent to the Mississippi River Plume

    Science.gov (United States)

    Rabalais, N. N.; Turner, R. E.

    2005-05-01

    The northern Gulf of Mexico receives the freshwater and constituent flux from the Mississippi River, which integrates 40% of the lower 48 United States. In the last half of the 20th century, the flux of nitrogen tripled, phosphorus concentration appears to have increased, and silicate concentration decreased. These changes result from landscape alterations over two centuries with an intensification of human activities that increased the flux of nitrogen and phosphorus particularly in the 1960s to 1980s. Evidence for eutrophication in the coastal ecosystem includes an increase in algal biomass, carbon accumulation from nutrient-enhanced production, worsening oxygen deficiency in the lower water column, and shifts in food web structure. The extent of the oxygen deficiency reaches 20,000 km2 of the inner continental shelf over long periods in summer with the potential for affecting commercially important fisheries in the Gulf. There is daily, weekly and seasonal variability in currents and stratification on the shelf and, therefore, no simple description of the couplings between nutrient delivery, carbon production in surface waters and delivery to and cycling in bottom waters. There are, however, multiple lines of evidence to implicate changes in riverine nutrient loads with overall primary and secondary production, carbon accumulation at the seabed, and low oxygen conditions on the shelf. The change in nutrient loads and responses of the northern Gulf coastal ecosystem, including widespread, severe seasonal hypoxia, parallel similar conditions in the coastal ocean on a global scale.

  9. 50 CFR 226.205 - Critical habitat for Snake River sockeye salmon, Snake River fall chinook salmon, and Snake River...

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Critical habitat for Snake River sockeye salmon, Snake River fall chinook salmon, and Snake River spring/summer chinook salmon. 226.205 Section... Snake River sockeye salmon, Snake River fall chinook salmon, and Snake River spring/summer...

  10. 33 CFR 207.380 - Red Lake River, Minn.; logging regulations for portion of river above Thief River Falls.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Red Lake River, Minn.; logging regulations for portion of river above Thief River Falls. 207.380 Section 207.380 Navigation and Navigable... Red Lake River, Minn.; logging regulations for portion of river above Thief River Falls. (a)...

  11. Sediment Transport at River Lima Estuary: Developing a Sound Methodology to Assess Sediment River Basin Input to an Erosion Prone Coast (NW Iberian Peninsula)

    Science.gov (United States)

    Pinho, J.; Costa, N.; Venâncio, S.; Martins, M.; Vieira, J.; Granja, H.

    2016-12-01

    The NW coast of Iberian Peninsula is mainly formed by rocky cliffs northern of the river Minho mouth and by narrow sandy beaches south of this river. These beaches are mainly in a sedimentary deficit status resulting from the north-south longitudinal drift driven by the dominant wave climate that acts from the NW direction. In this scenario understand and quantify river sediment inputs to the coast is crucial in order to follow a sustainable management policy to mitigate erosion impacts both in the natural and social environments. This work will present results from research conducted at rive Lima Estuary, one of the rivers flowing to the NW Iberian coast, based on both numerical modeling and field data acquisition. A hydrological model of the river basin and a detailed morphodynamic model of the estuary were implemented. Instrumentation of the estuary that is being conducted comprises traditional sensor pressures and new ones that are being designed and assembled to be installed at different measurement stations within the estuary. Modelling results for flood events showed that the river is capable of remove all the sediments that are deposited in the narrow estuarine canal located near the river mouth. Some of these sediments are immediately deposited downstream, within the interior of the harbor. Here, there is a strong possibility of silting of the river mouth and the central area of the harbor. Since the river flows during extreme events are controlled by an upstream reservoir, the capacity of the river to transport sediments to the coast was lowered during the last decades, which, moreover, requires dredging works over the years to maintain navigation depth requirements. Dredging sediments should be correctly deposited at the coast in order to properly feed the longitudinal drift, otherwise they will be out of the system, which aggravate the installed erosion tendency.

  12. Investigation and application of subsurface flow constructed wetland in water purification for the polluted river and lake in northern China%北方地区受污染河湖水体潜流湿地净化技术研究与工程应用

    Institute of Scientific and Technical Information of China (English)

    黄炳彬; 何春利; 易作明; 胡晓静; 吴震; 杜向群

    2012-01-01

    结合实验研究和工程应用实践,在湿地填料选择、水力负荷变化、植物特性、结构优化、越冬运行等方面,对我国北方地区潜流人工湿地设计、建设、运行管理中的关键技术问题开展了系统、深入研究.结果表明:石灰石、粗砂等脱氮除磷综合效果较好,且取材方便、价格便宜,应是人工湿地主选填料,钢渣、褐铁矿除磷效果良好、沸石的氨氮吸附能力强,可作为辅助材料;湿地植物对水质净化贡献约为5%~15%,其地上部分的生物量移除贡献不足5%,湿地植物对系统水力负荷维持、冬季保温、生态景观等还具有较大贡献;以植物保温为主,结合冰下取水、水位管理等可实现北方地区潜流湿地冬季正常运行;优化提出了竖向复合流湿地结构,具有节约用地、硝化-反硝化作用效果显著、抗淤堵等特点.研究成果已在工程实践中得到成功应用,对人工湿地在我国北方地区的推广应用具有重要借鉴意义.%On the basis of experimental studies and practical application, the key factors in design, construction, and operation of the subsurface flow constructed wetland in northern China are summarized in this paper. The factors investigated in this study include media selection, hydraulic loading rate, aquatic plant screening, structure optimization, and operation in winter. The results clearly showed that the limestone and sand should be selected as the major media of subsurface flow constructed wetland considering the performance of nitrogen and phosphorus removal, the availability and the price. The steel slag and limonite with excellent phosphorus removal, and zeolite with well adsorption ability of ammonia can be used as the secondary media. The wetland plants totally contribute only about 5% -15% to water quality improvement with a less-than-5% contribution by the harvesting of the aboveground biomass. However, wetland plants can make a large

  13. Impact of hydroelectric development upon a northern Manitoba native community

    Energy Technology Data Exchange (ETDEWEB)

    Waldram, J.B.

    1983-01-01

    This dissertation describes the process of underdevelopment among the Cree Indian people of South Indian Lake, in Northern Manitoba, Canada, following the construction of the Churchill-Nelson River Hydro Project in 1975. The dissertation seeks to link the ecological, political, economic, socio-cultural and health aspects of the impact of the hydro project within the framework of the historical process of underdevelopment as it has occurred in Latin America, among Native people in the United States, and among Native people in Northern Canada. Utilizing both qualitative and quantitative data, a process of increased dependence is described as the product of two related processes. The first process is the impairment of the local commercial and domestic economy caused by the flooding of Southern Indian Lake, which has resulted in a decline in local productivity. The second process is the enhancement of consumerism through rising consumer expectations and a post-project increase in available goods and services which the people are increasingly unable to afford. The overall result has been a process of economic divergence at the local level. The dissertation concludes that the process of underdevelopment which has occurred in South Indian Lake has been the result primarily of changes in the local ecological system caused by the construction of the hydro project. These ecological changes have, in turn, resulted in secondary changes in the socio-economic system.

  14. Pteridophyta collected in Northern Nigeria and Northern Cameroon

    Directory of Open Access Journals (Sweden)

    Jan kornaś

    2014-01-01

    Full Text Available 25 species of Pteridophyta were collected in Northern Nigeria (mainly the Lake Chad Basin and the Mandara Mts. and in the neighbouring parts of Cameroon. 11 of them have not been recorded previously from this area: Isoetes schweinfurthii A. Br. in Bak., Selaginella tenerrima A. Br. ex Kuhn, Ophioglossum gomenzianum Welw. ex A. Br., Marsilea coromandeliana Willd., M. distorta A. Br., M. nubica A. Br., M. subterranea Lepr. ex A. Br., Azolla africana Desv., Ceratopteris richardii Brogn., Adiantum capillus-veneris Linn., and Actiniopleris semiflabellata Pic. Ser.

  15. 33 CFR 117.734 - Navesink River (Swimming River).

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Navesink River (Swimming River). 117.734 Section 117.734 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... (Swimming River). The Oceanic Bridge, mile 4.5, shall open on signal; except that, from December 1 through...