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Sample records for river-floodplain system danube

  1. pCO2 and enzymatic activity in a river floodplain system of the Danube under different hydrological settings.

    NASA Astrophysics Data System (ADS)

    Sieczko, Anna; Demeter, Katalin; Mayr, Magdalena; Meisterl, Karin; Peduzzi, Peter

    2014-05-01

    Surface waters may serve as either sinks or sources of CO2. In contrast to rivers, which are typically sources of CO2 to the atmosphere, the role of fringing floodplains in CO2 flux is largely understudied. This study was conducted in a river-floodplain system near Vienna (Austria). The sampling focused on changing hydrological situations, particularly on two distinct flood events: a typical 1-year flood in 2012 and an extraordinary 100-year flood in 2013. One objective was to determine partial pressure of CO2 (pCO2) in floodplain lakes with different degree of connectivity to the main channel, and compare the impact of these two types of floods. Another aim was to decipher which fraction of the dissolved organic matter (DOM) pool contributed to pCO2 by linking pCO2 with optical properties of DOM and extracellular enzymatic activity (EEA) of microbes. The EEA is a valuable tool, especially for assessing the non-chromophoric but rapidly utilized DOM-fraction during floods. In 2012 and 2013, the floodplain lakes were dominated by supersaturated pCO2 conditions, which indicates that they served as CO2 sources. Surprisingly, there were no significant differences in pCO2 between the two types of flood. Our findings imply that the extent of the flood had minor impact on pCO2, but the general occurrence of a flood appears to be important. During the flood in 2013 significantly more dissolved organic carbon (DOC) (p<0.05) was introduced into the floodplain. The optical measurements pointed towards more refractory DOM, with higher molecular weight and humic content during the flood in 2013 compared to 2012. However there were no significant differences in EEA between the two floods. Few days after beginning of the floods in 2012 and 2013, an increase in activity of carbon-acquiring enzymes (EEA-C) was observed. We also found positive correlations of pCO2with EEA-C both in 2012 (r=0.86, p<0.01) and in 2013 (r=0.73, p<0.05). The above findings imply that some fraction of DOM

  2. Variable enzymatic activity of prokaryotes under different hydrological settings in a river floodplain of the Danube

    NASA Astrophysics Data System (ADS)

    Sieczko, Anna; Meisterl, Karin; Peduzzi, Peter

    2013-04-01

    This study tackles the role of different hydrological settings in a river-floodplain for organic matter processing by bacteria. Sampling locations in the Danube river-floodplain near Vienna (Austria) were chosen in a way that they represent a gradient of connectivity to the main river. We focused on the influence of variable hydrological connectivity and retention on microbial substrate utilization in the different subsystems of this river-floodplain section. We investigated extracellular enzymatic activity (EEA) both associated with particles (PA) and in the ambient water (FL). The activity of six enzymes was assessed: enzymes involved in the metabolism of carbon (β-d-glucosidase, α-d-glucosidase, β-d-xylosidase, cellobiohydrolase), peptide (endopeptidase [Endo]) and for degradation of refractory lignin material (phenol oxidase [PhOx]). We hypothesized that the degree of connectivity and water exchange in floodplain lakes influences prokaryotic enzymatic activity and productivity both on particles and in the surrounding water. The strong correlation between endopeptidase and phenol oxidase of the FL fraction in all locations suggests a tight coupling of enzymes responsible for utilization of labile and refractory material. Our results indicate that particle-associated bacterial growth in frequently flooded locations was supported by allochthonous carbon derived from polysaccharide hydrolysis, whereas in isolated locations, bacterial biomass was fuelled with carbon obtained largely from lignin utilization. This implies that prolonged residence time in isolated locations allows more refractory material to be utilized. Most of the enzymes (PA and FL) did not show clear dependencies on the degree of connectivity. However, phenol oxidase displayed an interesting pattern: activity of PhOx in ambient water decreased, whereas PA PhOx increased, together with the degree of connectivity. The study also demonstrates enhanced metabolism of the PA bacterial community and a

  3. Ecological validity of river-floodplain system assessment by planktonic crustacean survey (Branchiata: Branchiopoda).

    PubMed

    Illyová, Marta; Matečný, Igor

    2014-07-01

    Studies of the Slovakian Danube have indicated profound changes in the structures of several invertebrate assemblages in the section of the river bypassed by the Gabčíkovo hydroelectric project in 1992 and in adjacent floodplain water bodies. The present study investigates the relationship between hydrological connectivity and species diversity in the old main channel and adjacent left-bank water bodies, using resident cladocerans as indicators of the ecological integrity of the river-floodplain system. The work aimed to quantify cladoceran habitat preferences using habitat values (HV) and indication weights (IW) calculated from data accumulated during long-term monitoring of planktonic communities of the Danube floodplain (1,840.5-1,804 rkm) and supplemented with data from the literature. Although not listed as an indicator group in the European Union Water Framework Directive, cladocerans are shown to be highly apposite in the ecological assessment of river-floodplain systems. Of 71 recorded cladoceran species, 19 taxa showed a preference for eupotamal habitats, 24 species preferred eupotamal B/parapotamal waters, and 28 cladocerans were found to prefer the plesiopotamal/paleopotamal habitat type. Identified habitat types follow a gradient of hydrological connectivity with the main river channel, ranging from the eupotamal to more or less isolated floodplain water bodies. A secondary aim was to use the calculated values to assess the ecological integrity of the river-floodplain system. The key element of this procedure is the calculation of the Floodplain Index (FI) (Chovanec et al. Large Rivers, 15(1-4), 169-185 2005) from the summation of the habitat values and indication weights of all species present at the sampling sites. Calculated index values indicate the extent of disruption to lateral connectivity in the floodplain area.

  4. Assessment of flood-induced changes of phytoplankton along a river-floodplain system using the morpho-functional approach.

    PubMed

    Mihaljević, Melita; Spoljarić, Dubravka; Stević, Filip; Zuna Pfeiffer, Tanja

    2013-10-01

    In this research, we aimed to find out how the differences in hydrological connectivity between the main river channel and adjacent floodplain influence the changes in phytoplankton community structure along a river-floodplain system. The research was performed in the River Danube floodplain (Croatian river section) in the period 2008-2009 characterised by different flooding pattern on an annual time scale. By utilising the morpho-functional approach and multivariate analyses, the flood-derived structural changes of phytoplankton were analysed. The lake stability during the isolation phase triggered the specific pattern of morpho-functional groups (MFG) which were characterised by cyanobacterial species achieving very high biomass. Adversely, the high water turbulence in the lake during the frequent and extreme flooding led to evident similarity between lake and river assemblages. Besides different diatom species (groups of small and large centrics and pennates), which are the most abundant representatives in the river phytoplankton, many other groups such as cryptophytes and colonial phytomonads appeared to indicate altered conditions in the floodplain driven by flooding. Having different functional properties, small centric diatom taxa sorted to only one MFG cannot clearly reflect environmental changes that are shown by the species-level pattern. Disadvantages in using the MFG approach highlight that it is still necessary to combine it with taxonomical approach in monitoring of phytoplankton in the river-floodplain ecosystems.

  5. Hydromorphological control of nutrient cycling in complex river floodplain systems

    NASA Astrophysics Data System (ADS)

    Hein, T.; Bondar-Kunze, E.; Felkl, M.; Habersack, H.; Mair, M.; Pinay, G.; Tritthart, M.; Welti, N.

    2009-04-01

    potential effects on the main channel in a large river, the Danube River. During the growing season of 2006 and the end of the growing season 2007, a large-scale field survey was completed for two areas in the floodplain stretch of the Danube River one of which has recently undergone restoration via reconnection to the Danube River main channel. The sampling compared the sediment nutrient concentrations and potential denitrification and respiration rates. With changing surface water connection to the Danube River, the water bodies in the two compared floodplains experienced different patterns of microbial processing rates, particularly potential denitrification. We demonstrate that principles of hydromorphological dynamics control nutrient cycling in the water column and at the water sediment interface. These findings confirm the environmental control on these processes and their potential use as proxies to assess the consequences of hydrological changes by restoration measures on river ecosystem functioning.

  6. Spatio-temporal assessment of aqueous habitat dynamics at the Danube river floodplain based on historical topographic maps and remote sensing data

    NASA Astrophysics Data System (ADS)

    Farkas-Iványi, Kinga; Mészáros, János; Pásztor, László

    2016-04-01

    The basic requirements of sustainable restoration along rivers is the detection and evaluation of the historical changes in the landscape shaping processes. Identification of historical changes and habitat dynamics are essential criteria for understanding the geomorphological response of the fluvial system to flood discharges. Danube had three main types of channel adjustment in Szigetköz at the border of Hungary and Slovakia; the anabranching river section with medium flow velocity properties, the anastomosing river section with less intensive runoff conditions, and the meandering river section, with slow flow velocity properties. Our aim was to define, which section is the most responsive for near-natural and anthropogenic changes and which is the most stubborn against them, or see if they react in the same way. The parameters of the analysis were fluvial forms, their erosion, types of vegetation and nodes of bars and islands. The analysis was based on georeferenced topographic maps and remote sensing data of eight different dates from the last 200 years. The active channel (AC = main channel + side arms + backwaters + gravel/sand bars) and the habitat composition (HC = % of individual habitat types of AC) were defined for the whole time scale for extracting the most dynamic nodes of the active zone. After we were tracing down the areas of habitat succession and regeneration, by the comparison of adjacent time periods, we concluded that the three different channel types react differently for near-natural changes (e.g. the rejuvenation of the anabranching area was twice intensive than the anastomosing river section before channelization), but react with the same processes (e.g. terrestrialisation) for anthropogenic effects. Our poster will represent these preliminary results besides used datasets and methods.

  7. Channel pattern and river-floodplain dynamics in forested mountain river systems

    NASA Astrophysics Data System (ADS)

    Beechie, Timothy J.; Liermann, Martin; Pollock, Michael M.; Baker, Sarah; Davies, Jeremy

    2006-08-01

    Channel pattern effectively stratifies the dynamics of rivers and floodplains in forested mountain river systems of the Pacific Northwest, USA. Straight channels are least dynamic, with relatively slow floodplain turnover and floodplains dominated by old surfaces. Braided channels are most dynamic, with floodplain turnover as low as 25 years and predominantly young floodplain surfaces. Island-braided and meandering channels have intermediate dynamics, with moderately frequent disturbances (erosion of floodplain patches) maintaining a mix of old and young surfaces. Return intervals for the erosion of floodplains increase in the order of braided, island-braided, meandering, and straight (8, 33, 60, and 89 years, respectively). A threshold for the lateral migration of a channel occurs at a bankfull width of 15-20 m. The most likely mechanism underlying this threshold is that larger channels are deep enough to erode below the rooting zone of bank vegetation. Above this threshold, channels not confined between valley walls exhibit channel patterns distinguishable by slope and discharge, and slope-discharge domains can be used to predict channel patterns. Meandering and braided patterns are most consistently identified by the model, and prediction errors are largely associated with indistinct transitions among channel patterns that are adjacent in plots of slope against discharge. Locations of straight channels are difficult to identify accurately with the current model. The predicted spatial distribution of channel patterns reflects a downstream decline in channel slope, which is likely correlated with a declining ratio of bed load to suspended load. Ecological theory suggests that biological diversity should be highest where the intermediate disturbance regime of island-braided channels sustains high diversity of habitat and successional states through time.

  8. Hydrologic and geomorphic considerations in restoration of river-floodplain connectivity in a highly altered river system, Lower Missouri River, USA

    USGS Publications Warehouse

    Jacobson, Robert B.; Janke, Tyler P.; Skold, Jason J.

    2011-01-01

    Planning for restoration of river-floodplain systems requires understanding how often and how much of a floodplain may be inundated, and how likely the floodplain is to retain the water once flooded. These factors depend fundamentally on hydrology and geomorphology of the channel and floodplain. We discuss application of an index of river-floodplain connectivity, the Land Capability Potential Index (LCPI), to regional-scale restoration planning along 600 km of the Lower Missouri River. The LCPI integrates modeled water-surface elevations, floodplain topography, and soils to index relative wetness of floodplain patches. Geomorphic adjustment of the Lower Missouri River to impoundment and channel engineering has altered the natural relations among hydrology, geomorphology, and floodplain soils, and has resulted in a regional upstream to downstream gradient in connectivity potential. As a result, flow-regime management is limited in its capacity to restore floodplain ecosystems. The LCPI provides a tool for identifying and mapping floodplain restoration potential, accounting for the geomorphic adjustment. Using simple criteria, we illustrate the utility of LCPI-like approaches in regional planning for restoration of plains cottonwood (Populus deltoides) communities, hydrologically connected floodplain wetlands, and seasonal floodplain wetlands.

  9. How do long-term development and periodical changes of river-floodplain systems affect the fate of contaminants? Results from European rivers.

    PubMed

    Lair, G J; Zehetner, F; Fiebig, M; Gerzabek, M H; van Gestel, C A M; Hein, T; Hohensinner, S; Hsu, P; Jones, K C; Jordan, G; Koelmans, A A; Poot, A; Slijkerman, D M E; Totsche, K U; Bondar-Kunze, E; Barth, J A C

    2009-12-01

    In many densely populated areas, riverine floodplains have been strongly impacted and degraded by river channelization and flood protection dikes. Floodplains act as buffers for flood water and as filters for nutrients and pollutants carried with river water and sediment from upstream source areas. Based on results of the EU-funded "AquaTerra" project (2004-2009), we analyze changes in the dynamics of European river-floodplain systems over different temporal scales and assess their effects on contaminant behaviour and ecosystem functioning. We find that human-induced changes in the hydrologic regime of rivers have direct and severe consequences on nutrient cycling and contaminant retention in adjacent floodplains. We point out the complex interactions of contaminants with nutrient availability and other physico-chemical characteristics (pH, organic matter) in determining ecotoxicity and habitat quality, and draw conclusions for improved floodplain management.

  10. How do long-term development and periodical changes of river-floodplain systems affect the fate of contaminants? Results from European rivers.

    PubMed

    Lair, G J; Zehetner, F; Fiebig, M; Gerzabek, M H; van Gestel, C A M; Hein, T; Hohensinner, S; Hsu, P; Jones, K C; Jordan, G; Koelmans, A A; Poot, A; Slijkerman, D M E; Totsche, K U; Bondar-Kunze, E; Barth, J A C

    2009-12-01

    In many densely populated areas, riverine floodplains have been strongly impacted and degraded by river channelization and flood protection dikes. Floodplains act as buffers for flood water and as filters for nutrients and pollutants carried with river water and sediment from upstream source areas. Based on results of the EU-funded "AquaTerra" project (2004-2009), we analyze changes in the dynamics of European river-floodplain systems over different temporal scales and assess their effects on contaminant behaviour and ecosystem functioning. We find that human-induced changes in the hydrologic regime of rivers have direct and severe consequences on nutrient cycling and contaminant retention in adjacent floodplains. We point out the complex interactions of contaminants with nutrient availability and other physico-chemical characteristics (pH, organic matter) in determining ecotoxicity and habitat quality, and draw conclusions for improved floodplain management. PMID:19604610

  11. Hydrological Signature From River-Floodplain Interactions

    NASA Astrophysics Data System (ADS)

    Paiva, R. C. D.; Fleischmann, A. S.; Collischonn, W.; Sorribas, M.; Pontes, P. R.

    2015-12-01

    Understanding river-floodplain hydraulic processes is fundamental to promote comprehension of related water paths, biogeochemicalcyclesand ecosystems. Large river basins around the globe present enormous developed floodplains, which strongly affect flood waves and water dynamics. Since most of these river-floodplain interactions are not monitored, it is interesting to develop strategies to understand such processes through characteristic hydrological signatures, e.g. hydrographs. We studied observed hydrographs from large South American rivers and found that in several cases rivers with extensive wetlands present a particular hydrograph shape, with slower rising limb in relation to the receding one, due to storage effects and the associated decrease of wave celerity with stage. A negative asymmetry in the hydrograph is generated, which is higher when more water flows through floodplains upstream of the observed point. Finally, we studied the Amazon basin using gauged information and simulation results from the MGB-IPH regional hydrological model. Major rivers with larger wetland areas (e.g. Purus, Madeira and Juruá) were identified with higher negative asymmetry in their hydrographs. The hydrodynamic model was run in scenarios with and without floodplains, and results supported that floodplain storage affects hydrographs in creating a negative asymmetry, besides attenuating peaks, increasing hydrograph smoothness and increasing minimum flows. Finally, different wetland types could be distinguished with hydrograph shape, e.g. differing wetlands fed by local rainfall from wetlands due to overbank flow (floodplains). These metrics and concepts on hydrograph features have great potential to infer about river-floodplain processes from large rivers and wetland systems.

  12. Algal extracellular release in river-floodplain dissolved organic matter: response of extracellular enzymatic activity during a post-flood period

    PubMed Central

    Sieczko, Anna; Maschek, Maria; Peduzzi, Peter

    2015-01-01

    River-floodplain systems are susceptible to rapid hydrological events. Changing hydrological connectivity of the floodplain generates a broad range of conditions, from lentic to lotic. This creates a mixture of allochthonously and autochthonously derived dissolved organic matter (DOM). Autochthonous DOM, including photosynthetic extracellular release (PER), is an important source supporting bacterial secondary production (BSP). Nonetheless, no details are available regarding microbial extracellular enzymatic activity (EEA) as a response to PER under variable hydrological settings in river-floodplain systems. To investigate the relationship between bacterial and phytoplankton components, we therefore used EEA as a tool to track the microbial response to non-chromophoric, but reactive and ecologically important DOM. The study was conducted in three floodplain subsystems with distinct hydrological regimes (Danube Floodplain National Park, Austria). The focus was on the post-flood period. Enhanced %PER (up to 48% of primary production) in a hydrologically isolated subsystem was strongly correlated with β-glucosidase, which was related to BSP. This shows that—in disconnected floodplain backwaters with high terrestrial input—BSP can also be driven by autochthonous carbon sources (PER). In a semi-isolated section, in the presence of fresh labile material from primary producers, enhanced activity of phenol oxidase was observed. In frequently flooded river-floodplain systems, BSP was mainly driven by enzymatic degradation of particulate primary production. Our research demonstrates that EEA measurements are an excellent tool to describe the coupling between bacteria and phytoplankton, which cannot be deciphered when focusing solely on chromophoric DOM. PMID:25741326

  13. Hyporheic flow patterns in relation to large river floodplain attributes

    EPA Science Inventory

    Field-calibrated models of hyporheic flow have emphasized low-order headwater systems. In many cases, however, hyporheic flow in large lowland river floodplains may be an important contributor to ecosystem services such as maintenance of water quality and habitat. In this study, ...

  14. Impact of drying and re-flooding of sediment on phosphorus dynamics of river-floodplain systems.

    PubMed

    Schönbrunner, Iris M; Preiner, Stefan; Hein, Thomas

    2012-08-15

    One of the consequences of human impacts on floodplains is a change in sedimentation leading to enhanced floodplain aggradation. Thus, accumulated sediments rich in nutrients might interfere with floodplain restoration. In this study we investigated the phosphorus release behavior of sediments from shallow backwaters of an isolated floodplain of the Danube River situated east of the city of Vienna with the aim to understand the effects of changes in dry/wet cycles on established floodplain sediments. In the light of restoration plans aiming at increased surface water exchange with the river main channel, the response of sediments to frequent alternations between desiccation and inundation periods is a key issue as changes of sediment properties are expected to affect phosphorus release. In order to determine the effect of changing hydrological conditions on internal phosphorus loading, we exposed sediments to different dry/wet treatments in a laboratory experiment. Total phosphorus (TP) release from sediments into the water column increased with increasing duration of dry periods prior to re-wetting. Partial correlation analysis showed significant positive correlations between ΔTP and ΔNH(4)(+) as well as between ΔTP and ΔFe(3+) concentrations (Δ refers to the difference between the final and initial concentration during the wetting period), indicating that enhanced mineralization rates leading to a concomitant release of NH(4)(+) and TP and the reduction of iron hydroxides leading to a concomitant release of Fe(3+) and TP are the mechanisms responsible for the rise in TP. Repeated drying and wetting resulted in elevated phosphorus release. This effect was more pronounced when drying periods led to an 80% reduction in water content, indicating that the degree of drying is a major determinant controlling phosphorus release upon re-wetting. The reconnection of isolated floodplains will favor fluctuating hydrologic conditions and is therefore expected to

  15. Impact of drying and re-flooding of sediment on phosphorus dynamics of river-floodplain systems.

    PubMed

    Schönbrunner, Iris M; Preiner, Stefan; Hein, Thomas

    2012-08-15

    One of the consequences of human impacts on floodplains is a change in sedimentation leading to enhanced floodplain aggradation. Thus, accumulated sediments rich in nutrients might interfere with floodplain restoration. In this study we investigated the phosphorus release behavior of sediments from shallow backwaters of an isolated floodplain of the Danube River situated east of the city of Vienna with the aim to understand the effects of changes in dry/wet cycles on established floodplain sediments. In the light of restoration plans aiming at increased surface water exchange with the river main channel, the response of sediments to frequent alternations between desiccation and inundation periods is a key issue as changes of sediment properties are expected to affect phosphorus release. In order to determine the effect of changing hydrological conditions on internal phosphorus loading, we exposed sediments to different dry/wet treatments in a laboratory experiment. Total phosphorus (TP) release from sediments into the water column increased with increasing duration of dry periods prior to re-wetting. Partial correlation analysis showed significant positive correlations between ΔTP and ΔNH(4)(+) as well as between ΔTP and ΔFe(3+) concentrations (Δ refers to the difference between the final and initial concentration during the wetting period), indicating that enhanced mineralization rates leading to a concomitant release of NH(4)(+) and TP and the reduction of iron hydroxides leading to a concomitant release of Fe(3+) and TP are the mechanisms responsible for the rise in TP. Repeated drying and wetting resulted in elevated phosphorus release. This effect was more pronounced when drying periods led to an 80% reduction in water content, indicating that the degree of drying is a major determinant controlling phosphorus release upon re-wetting. The reconnection of isolated floodplains will favor fluctuating hydrologic conditions and is therefore expected to

  16. A Trans-disciplinary Hydrogeological Systems Analysis Approach for Identifying and Assessing Managed Aquifer Recharge Options: Example from the Darling River Floodplain, N.S.W., Australia

    NASA Astrophysics Data System (ADS)

    Lawrie, K.; Brodie, R. S.; Tan, K. P.; Halas, L.; Magee, J.; Gow, L.; Christensen, N. B.

    2013-12-01

    Surface water availability and quality generally limits managed aquifer recharge (MAR) opportunities in inland Australia's highly salinized landscapes and groundwater systems. Economic factors also commonly limit MAR investigations to shallow freshwater groundwater systems near existing infrastructure. Aquifer opportunities lie mainly in zones of fresh groundwater in relatively thin fluvial sedimentary aquifer systems with highly variable hydraulic properties. As part of a broader strategy to identify water savings in the Murray-Darling Basin, the Broken Hill Managed Aquifer Recharge (BHMAR) project was tasked with identifying and assessing MAR and/or groundwater extraction options to reduce evaporative losses from existing surface water storages, secure Broken Hill's water supply, protect the local environment and heritage, and return water to the river system. A trans-disciplinary research approach was used to identify and assess MAR options across a broad area of the Darling River floodplain. This methodology enabled the team to recognise fundamental problems in discipline approaches, helped identify critical data gaps, led to significant innovation across discipline boundaries, was critical in the development of a new hydrogeological conceptual model, facilitated development of new models of landscape, geological and tectonic evolution of the study area, and enabled completion of pre-commissioning maximal and residual MAR risk assessments. An airborne electromagnetics (AEM) survey, acquired over a large (>7,500 sq km) area of the Darling Floodplain, enabled rapid identification of a multi-layer sequence of aquifers and aquitards, while a phased assessment methodology was developed to rapidly identify and assess over 30 potential MAR targets (largely in fresh groundwater zones within palaeochannels and at palaeochannel confluences). Hydraulic properties were confirmed by a 7.5 km drilling program (100 sonic and rotary mud holes), and complementary field

  17. River-floodplain exchange and its effects on the fluvial oxygen regime in a large tropical river system (Kafue Flats, Zambia)

    NASA Astrophysics Data System (ADS)

    Zurbrügg, Roland; Wamulume, Jason; Kamanga, Romas; Wehrli, Bernhard; Senn, David B.

    2012-09-01

    Hydrological exchange between a river and its floodplain plays a critical role in maintaining key ecosystem services like habitat formation, nutrient transformation, and flood attenuation. We studied the spatial and temporal patterns of river-floodplain exchange in the Kafue Flats, a 6500-km2, dam-impacted floodplain ecosystem in Zambia. In addition, we characterized the effects of floodplain runoff on river biogeochemistry and assessed dam-related changes in the hydrological regime. The basic flood pulse concept poorly describes conditions in the Kafue Flats. Instead, high resolution measurements of discharge and tracers (specific conductivity,δ18O-H2O) along 410 km of river revealed substantial spatial variations in both the magnitude and direction of river-floodplain exchange. During peak discharge, a river channel constriction, 230 km into the floodplain, diverted as much as 80% of the river's ˜700 m3 s-1discharge into the floodplain. As a net result, >80% of the water exiting the Kafue Flats via the river, either passed through the floodplain or originated from precipitation on the floodplain. This floodplain-derived water had a strong impact on river water quality, resulting in a seasonally recurring sharp decline in dissolved oxygen levels to <50μM that persisted for 150 km downstream. A comparison with historical flow data showed that concurrent bank overflow and floodplain inflows were a sustained pattern during the wet season. However, lateral exchange over an annual cycle has been reduced by as much as 50% due to dam operation.

  18. High methane emission from Siberian river floodplains

    NASA Astrophysics Data System (ADS)

    Mi, Yanjiao; van Huissteden, Ko; Dolman, Han

    2013-04-01

    Methane contributes significantly to global warming. Methane emission is essentially the net result of a balance between CH4 production by methanogenic bacteria in anaerobic soil zones, and CH4 oxidation by methanotrophic bacteria in aerated soil zones and plants. Arctic and sub-arctic permafrost holds a large amount of climate vulnerable carbon. In particular river floodplains are carbon-rich soils. River floodplains in this area are periodically or permanently submerged. The occurrence of flooding decreases soil oxygen availability, providing an ideal anaerobic environment for methane generation. Here we compare the chamber measurements of the methane flux from tundra and floodplain of the Kytalyk site in Northeast Siberia. Model experiments on this site have also been carried out in order to better explain spatial and temporal variations in methane emissions from northern permafrost. This serves as a basis for further model development including modeling of the flooding regime on the floodplain.

  19. Hyporheic flow patterns in relation to large river floodplain attributes Journal

    EPA Science Inventory

    Field-calibrated models of hyporheic flow have emphasized low-order headwater systems. In many cases, however, hyporheic flow in large lowland river floodplains may be an important contributor to ecosystem services such as maintenance of water quality and habitat. In this study, ...

  20. Gravel-bed river floodplains are the ecological nexus of glaciated mountain landscapes.

    PubMed

    Hauer, F Richard; Locke, Harvey; Dreitz, Victoria J; Hebblewhite, Mark; Lowe, Winsor H; Muhlfeld, Clint C; Nelson, Cara R; Proctor, Michael F; Rood, Stewart B

    2016-06-01

    Gravel-bed river floodplains in mountain landscapes disproportionately concentrate diverse habitats, nutrient cycling, productivity of biota, and species interactions. Although stream ecologists know that river channel and floodplain habitats used by aquatic organisms are maintained by hydrologic regimes that mobilize gravel-bed sediments, terrestrial ecologists have largely been unaware of the importance of floodplain structures and processes to the life requirements of a wide variety of species. We provide insight into gravel-bed rivers as the ecological nexus of glaciated mountain landscapes. We show why gravel-bed river floodplains are the primary arena where interactions take place among aquatic, avian, and terrestrial species from microbes to grizzly bears and provide essential connectivity as corridors for movement for both aquatic and terrestrial species. Paradoxically, gravel-bed river floodplains are also disproportionately unprotected where human developments are concentrated. Structural modifications to floodplains such as roads, railways, and housing and hydrologic-altering hydroelectric or water storage dams have severe impacts to floodplain habitat diversity and productivity, restrict local and regional connectivity, and reduce the resilience of both aquatic and terrestrial species, including adaptation to climate change. To be effective, conservation efforts in glaciated mountain landscapes intended to benefit the widest variety of organisms need a paradigm shift that has gravel-bed rivers and their floodplains as the central focus and that prioritizes the maintenance or restoration of the intact structure and processes of these critically important systems throughout their length and breadth.

  1. Gravel-bed river floodplains are the ecological nexus of glaciated mountain landscapes

    PubMed Central

    Hauer, F. Richard; Locke, Harvey; Dreitz, Victoria J.; Hebblewhite, Mark; Lowe, Winsor H.; Muhlfeld, Clint C.; Nelson, Cara R.; Proctor, Michael F.; Rood, Stewart B.

    2016-01-01

    Gravel-bed river floodplains in mountain landscapes disproportionately concentrate diverse habitats, nutrient cycling, productivity of biota, and species interactions. Although stream ecologists know that river channel and floodplain habitats used by aquatic organisms are maintained by hydrologic regimes that mobilize gravel-bed sediments, terrestrial ecologists have largely been unaware of the importance of floodplain structures and processes to the life requirements of a wide variety of species. We provide insight into gravel-bed rivers as the ecological nexus of glaciated mountain landscapes. We show why gravel-bed river floodplains are the primary arena where interactions take place among aquatic, avian, and terrestrial species from microbes to grizzly bears and provide essential connectivity as corridors for movement for both aquatic and terrestrial species. Paradoxically, gravel-bed river floodplains are also disproportionately unprotected where human developments are concentrated. Structural modifications to floodplains such as roads, railways, and housing and hydrologic-altering hydroelectric or water storage dams have severe impacts to floodplain habitat diversity and productivity, restrict local and regional connectivity, and reduce the resilience of both aquatic and terrestrial species, including adaptation to climate change. To be effective, conservation efforts in glaciated mountain landscapes intended to benefit the widest variety of organisms need a paradigm shift that has gravel-bed rivers and their floodplains as the central focus and that prioritizes the maintenance or restoration of the intact structure and processes of these critically important systems throughout their length and breadth. PMID:27386570

  2. Gravel-bed river floodplains are the ecological nexus of glaciated mountain landscapes

    USGS Publications Warehouse

    Hauer, F. Richard; Locke, Harvey; Dreitz, Victoria; Hebblewhite, Mark; Lowe, Winsor; Muhlfeld, Clint C.; Nelson, Cara; Proctor, Michael F; Rood, Stewart B.

    2016-01-01

    Gravel-bed river floodplains in mountain landscapes disproportionately concentrate diverse habitats, nutrient cycling, productivity of biota, and species interactions. Although stream ecologists know that river channel and floodplain habitats used by aquatic organisms are maintained by hydrologic regimes that mobilize gravel-bed sediments, terrestrial ecologists have largely been unaware of the importance of floodplain structures and processes to the life requirements of a wide variety of species. We provide insight into gravel-bed rivers as the ecological nexus of glaciated mountain landscapes. We show why gravel-bed river floodplains are the primary arena where interactions take place among aquatic, avian, and terrestrial species from microbes to grizzly bears and provide essential connectivity as corridors for movement for both aquatic and terrestrial species. Paradoxically, gravel-bed river floodplains are also disproportionately unprotected where human developments are concentrated. Structural modifications to floodplains such as roads, railways, and housing and hydrologicaltering hydroelectric or water storage dams have severe impacts to floodplain habitat diversity and productivity, restrict local and regional connectivity, and reduce the resilience of both aquatic and terrestrial species, including adaptation to climate change. To be effective, conservation efforts in glaciated mountain landscapes intended to benefit the widest variety of organisms need a paradigm shift that has gravel-bed rivers and their floodplains as the central focus and that prioritizes the maintenance or restoration of the intact structure and processes of these critically important systems throughout their length and breadth.

  3. Gravel-bed river floodplains are the ecological nexus of glaciated mountain landscapes.

    PubMed

    Hauer, F Richard; Locke, Harvey; Dreitz, Victoria J; Hebblewhite, Mark; Lowe, Winsor H; Muhlfeld, Clint C; Nelson, Cara R; Proctor, Michael F; Rood, Stewart B

    2016-06-01

    Gravel-bed river floodplains in mountain landscapes disproportionately concentrate diverse habitats, nutrient cycling, productivity of biota, and species interactions. Although stream ecologists know that river channel and floodplain habitats used by aquatic organisms are maintained by hydrologic regimes that mobilize gravel-bed sediments, terrestrial ecologists have largely been unaware of the importance of floodplain structures and processes to the life requirements of a wide variety of species. We provide insight into gravel-bed rivers as the ecological nexus of glaciated mountain landscapes. We show why gravel-bed river floodplains are the primary arena where interactions take place among aquatic, avian, and terrestrial species from microbes to grizzly bears and provide essential connectivity as corridors for movement for both aquatic and terrestrial species. Paradoxically, gravel-bed river floodplains are also disproportionately unprotected where human developments are concentrated. Structural modifications to floodplains such as roads, railways, and housing and hydrologic-altering hydroelectric or water storage dams have severe impacts to floodplain habitat diversity and productivity, restrict local and regional connectivity, and reduce the resilience of both aquatic and terrestrial species, including adaptation to climate change. To be effective, conservation efforts in glaciated mountain landscapes intended to benefit the widest variety of organisms need a paradigm shift that has gravel-bed rivers and their floodplains as the central focus and that prioritizes the maintenance or restoration of the intact structure and processes of these critically important systems throughout their length and breadth. PMID:27386570

  4. Ecology of invasive Melilotus alba on Alaskan glacial river floodplains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    White sweetclover has recently invaded glacial river floodplains in Alaska. We sampled vegetation and measured environmental variables along transects located along the Nenana, Matanuska, and Stikine Rivers to describe plant communities and to determine the effects of white sweetclover on other plan...

  5. QMRAcatch: Human-Associated Fecal Pollution and Infection Risk Modeling for a River/Floodplain Environment.

    PubMed

    Derx, Julia; Schijven, Jack; Sommer, Regina; Zoufal-Hruza, Christa M; van Driezum, Inge H; Reischer, Georg; Ixenmaier, Simone; Kirschner, Alexander; Frick, Christina; de Roda Husman, Ana Maria; Farnleitner, Andreas H; Blaschke, Alfred Paul

    2016-07-01

    Protection of drinking water resources requires addressing all relevant fecal pollution sources in the considered catchment. A freely available simulation tool, QMRAcatch, was recently developed to simulate concentrations of fecal indicators, a genetic microbial source tracking (MST) marker, and intestinal pathogens in water resources and to conduct a quantitative microbial risk assessment (QMRA). At the same time, QMRAcatch was successfully applied to a region of the Danube River in Austria, focusing on municipal wastewater emissions. Herein, we describe extension of its application to a Danube River floodplain, keeping the focus on fecal sources of human origin. QMRAcatch was calibrated to match measured human-associated MST marker concentrations for a dry year and a wet year. Appropriate performance characteristics of the human-associated MST assay were proven by simulating correct and false-positive marker concentrations, as determined in human and animal feces. With the calibrated tool, simulated and measured enterovirus concentrations in the rivers were compared. Finally, the calibrated tool allowed demonstrating that 4.5 log enterovirus and 6.6 log norovirus reductions must be achieved to convert current surface water to safe drinking water that complies with a health-based target of 10 infections person yr. Simulations of the low- and high-pollution scenarios showed that the required viral reductions ranged from 0 to 8 log. This study has implications for water managers with interests in assessing robust catchment protection measures and water treatment criteria by considering the fate of fecal pollution from its sources to the point of abstraction. PMID:27380068

  6. QMRAcatch: Human-Associated Fecal Pollution and Infection Risk Modeling for a River/Floodplain Environment.

    PubMed

    Derx, Julia; Schijven, Jack; Sommer, Regina; Zoufal-Hruza, Christa M; van Driezum, Inge H; Reischer, Georg; Ixenmaier, Simone; Kirschner, Alexander; Frick, Christina; de Roda Husman, Ana Maria; Farnleitner, Andreas H; Blaschke, Alfred Paul

    2016-07-01

    Protection of drinking water resources requires addressing all relevant fecal pollution sources in the considered catchment. A freely available simulation tool, QMRAcatch, was recently developed to simulate concentrations of fecal indicators, a genetic microbial source tracking (MST) marker, and intestinal pathogens in water resources and to conduct a quantitative microbial risk assessment (QMRA). At the same time, QMRAcatch was successfully applied to a region of the Danube River in Austria, focusing on municipal wastewater emissions. Herein, we describe extension of its application to a Danube River floodplain, keeping the focus on fecal sources of human origin. QMRAcatch was calibrated to match measured human-associated MST marker concentrations for a dry year and a wet year. Appropriate performance characteristics of the human-associated MST assay were proven by simulating correct and false-positive marker concentrations, as determined in human and animal feces. With the calibrated tool, simulated and measured enterovirus concentrations in the rivers were compared. Finally, the calibrated tool allowed demonstrating that 4.5 log enterovirus and 6.6 log norovirus reductions must be achieved to convert current surface water to safe drinking water that complies with a health-based target of 10 infections person yr. Simulations of the low- and high-pollution scenarios showed that the required viral reductions ranged from 0 to 8 log. This study has implications for water managers with interests in assessing robust catchment protection measures and water treatment criteria by considering the fate of fecal pollution from its sources to the point of abstraction.

  7. Channel Pattern and the Intermediate Disturbance Hypothesis Predict Biodiversity in River-floodplain Ecosystems

    NASA Astrophysics Data System (ADS)

    Beechie, T.; Pollock, M.; Baker, S.; Morley, S.

    2005-05-01

    River-floodplain ecosystems are among the most diverse and dynamic environments in the world, yet mechanisms that regulate biodiversity in river corridors are poorly understood. In part, this stems from a lack of integration of geomorphological and biological concepts that link fluvial processes to biological diversity. Here we illustrate how channel pattern predicts biodiversity via the intermediate disturbance hypothesis (IDH). We show that (1) channel pattern predicts disturbance frequency and age diversity of patches, (2) there are distinct life history tradeoffs among colonizing and climax species, and (3) diversity should be highest in channel patterns with intermediate levels of disturbance. We first classify river-floodplains in northwestern USA using geomorphological channel patterns, and show how these patterns predict patch dynamics in river-floodplain systems. We then use space-for-time substitution to illustrate successional patterns of trees and aquatic invertebrates. Finally, we link reach-level patch dynamics to reach-level biodiversity of trees and aquatic invertebrates using the IDH. Patch age diversity is low in straight channels with low movement rates and mostly old surfaces, and low in braided channels with high movement rates and mostly young surfaces. Patch age diversity is highest in channels with intermediate movement rates (meandering and island-braided channels). Vegetation succession drives temporal patterns of biological diversity within individual terrestrial and aquatic patches (alpha diversity). Trees exhibit clear successional trade-offs as patches age, succeeding from hardwood-dominated at the colonizing stage to conifer-dominated at the climax stage. Highest within-patch species richness occurs at an intermediate age. Alpha diversity of aquatic invertebrates follows a similar pattern, probably in response to riparian forest succession and the shifting composition of detrital resources entering river and floodplain channels. We

  8. Survival tactics of Ranunculus species in river floodplains.

    PubMed

    He, J B; Bögemann, G M; van de Steeg, H M; Rijnders, J G; Voesenek, L A; Blom, C W

    1999-01-01

    The flooding resistance of four Ranunculus species was studied under controlled conditions and related to the tactics used by these species to survive in their natural habitat in river floodplains. R. bulbosus, a species from seldom-flooded river levées, was relatively intolerant of both waterlogging and complete submergence, due to a constitutively low level of aerenchyma in the root system. This lack of gas spaces resulted in high mortality rates during flooding treatments and an inability to use photosynthetically derived oxygen for root respiration during complete submergence. The pioneer R. sceleratus, predominantly abundant in low lying mudflats, was very resistant to waterlogging and shallow floods. Due to its constitutively high root porosity and its ability to greatly increase the elongation rate of petioles under water this species can ameliorate flooding stress. However, when leaf blades of R. sceleratus were unable to reach the water surface, this species died as quickly as the flooding-intolerant R. bulbosus. This indicates that fast elongation of petioles under water competes for energy and respirable reserves with maintenance processes. R. repens, a species from lower, frequently inundated floodplains, was very tolerant of prolonged waterlogging and submergence. Its high resistance to complete submergence under continuous darkness indicates that this species tolerates hypoxic and/or anoxic tissue conditions via metabolic adjustments. Lysigenous aerenchyma was also induced in the primary root system and in newly developed laterals, and it was able to use oxygen generated by underwater photosynthesis, for root respiration. R. acris, a species from less frequently flooded areas, was as resistant to waterlogging and submergence in the light as R. repens. However, it has a lower resistance than R. repens to complete submergence in the dark. A submergence pre-treatment increased the maximum net underwater photosynthetic rate in R. bulbosus, whereas a

  9. A spatial simulation model for forest succession in the Upper Mississippi River floodplain

    USGS Publications Warehouse

    Yin, Y.; Wu, Y.; Bartell, S.M.

    2009-01-01

    A Markov-chain transition model (FORSUM) and Monte Carlo simulations were used to simulate the succession patterns and predict a long-term impact of flood on the forest structure and growth in the floodplain of the Upper Mississippi River and Illinois River. Model variables, probabilities, functions, and parameters were derived from the analysis of two comprehensive field surveys conducted in this floodplain. This modeling approach describes the establishment, growth, competition, and death of individual trees for modeled species on a 10,000-ha landscape with spatial resolution of 1 ha. The succession characteristics of each Monte Carlo simulation are summed up to describe forest development and dynamics on a landscape level. FORSUM simulated the impacts of flood intensity and frequency on species composition and dynamics in the Upper Mississippi River floodplain ecosystem. The model provides a useful tool for testing hypotheses about forest succession and enables ecologists and managers to evaluate the impacts of flood disturbances and ecosystem restoration on forest succession. The simulation results suggest that the Markov-chain Monte Carlo method is an efficient tool to help organize the existing data and knowledge of forest succession into a system of quantitative predictions for the Upper Mississippi River floodplain ecosystem. ?? 2009 Elsevier B.V.

  10. Early Anthropogenic Transformation of the Danube-Black Sea System

    PubMed Central

    Giosan, Liviu; Coolen, Marco J. L.; Kaplan, Jed O.; Constantinescu, Stefan; Filip, Florin; Filipova-Marinova, Mariana; Kettner, Albert J.; Thom, Nick

    2012-01-01

    Over the last century humans have altered the export of fluvial materials leading to significant changes in morphology, chemistry, and biology of the coastal ocean. Here we present sedimentary, paleoenvironmental and paleogenetic evidence to show that the Black Sea, a nearly enclosed marine basin, was affected by land use long before the changes of the Industrial Era. Although watershed hydroclimate was spatially and temporally variable over the last ~3000 years, surface salinity dropped systematically in the Black Sea. Sediment loads delivered by Danube River, the main tributary of the Black Sea, significantly increased as land use intensified in the last two millennia, which led to a rapid expansion of its delta. Lastly, proliferation of diatoms and dinoflagellates over the last five to six centuries, when intensive deforestation occurred in Eastern Europe, points to an anthropogenic pulse of river-borne nutrients that radically transformed the food web structure in the Black Sea. PMID:22937219

  11. Ecology of invasive Melilotus albus on Alaskan glacial river floodplains

    USGS Publications Warehouse

    Conn, Jeff S.; Werdin-Pfisterer, Nancy R.; Beattie, Katherine L.; Densmore, Roseann V.

    2011-01-01

    Melilotus albus (white sweetclover) has invaded Alaskan glacial river floodplains. We measured cover and density of plant species and environmental variables along transects perpendicular to the Nenana, Matanuska, and Stikine Rivers to study interactions between M. albus and other plant species and to characterize the environment where it establishes. Melilotus albus was a pioneer species on recently disturbed sites and did not persist into closed canopy forests. The relationships between M. albus cover and density and other species were site-specific.Melilotus albus was negatively correlated with native species Elaeagnus commutata at the Nenana River, but not at the Matanuska River. Melilotus albus was positively correlated with the exotic species Crepis tectorumand Taraxacum officinale at the Matanuska River and T. officinale on the upper Stikine River. However, the high density of M. albus at a lower Stikine River site was negatively correlated with T. officinale and several native species including Lathyrus japonicus var. maritimus and Salix alaxensis. Glacial river floodplains in Alaska are highly disturbed and are corridors for exotic plant species movement. Melilotus albus at moderate to low densities may facilitate establishment of exotic species, but at high densities can reduce the cover and density of both exotic and native species.

  12. Vegetation and its relationship with geomorphologic units in the Parana River floodplain, Argentina

    NASA Astrophysics Data System (ADS)

    Marchetti, Z. Y.; Latrubesse, E. M.; Pereira, M. S.; Ramonell, C. G.

    2013-10-01

    The Parana River is one of the most important fluvial systems of South America and its floodplain includes the most diverse subtropical ecosystem on the continent. However, the relationship between basic aspects, such as the vegetation and geomorphology of the river floodplain, has scarcely been investigated. In this paper, the annual dynamics of vegetation in relation to the geomorphologic and hydrological characteristics of a river floodplain around 31° 30' S, are analyzed. The annual dynamics of vegetation was investigated using values of the Normalized Difference Vegetation Index (NDVI) obtained from satellite images at two scales of spatial analysis: the first, at the geomorphologic unit level, through several transects crossing the total width of each unit and, the second, through some transects selected from each unit. Our analysis considered variables of different temporal stability (such as geomorphology, hydrology, vegetation, precipitation, and ground temperature), using scenes corresponding to two hydrological cycles of the system (2009 and 2010), which represented relatively "dry" and "humid" years. Five main geomorphologic units were identified in the floodplain of this anabranching system, which were named considering the predominant landforms and the most important (or typical) water course of each area: Bars and Islands of the Main Channel of the Parana River (BI-MCH), Scroll Bars of the Colastine Branch (SB-C), Scroll Bars of the San Javier River Channel (SB-SJ), Crevasse Splays and Levees of the Malo-Mendieta minor channels (CSL-MM), and Crevasse Splays and Levees of the Santa Fe-Coronda river channels (CSL-SFC). These major units are assembled at different general levels and with variable slopes, which partially control the permanence and other characteristics of the flood flow. The crevasse splays and river levees units were predominantly characterized by herbaceous-bushy marshy vegetation, with low mean NDVI values, while SB-C and BI

  13. QMRAcatch - faecal microbial quality of water resources in a river-floodplain area affected by urban sources and recreational visitors

    NASA Astrophysics Data System (ADS)

    Derx, Julia; Schijven, Jack; Sommer, Regina; Kirschner, Alexander; Farnleitner, Andreas H.; Blaschke, Alfred Paul

    2016-04-01

    QMRAcatch, a tool to simulate microbial water quality including infection risk assessment, was previously developed and successfully tested at a Danube river site (Schijven et al. 2015). In the tool concentrations of target faecal microorganisms and viruses (TMVs) are computed at a point of interest (PI) along the main river and the floodplain river at daily intervals for a one year period. Even though faecal microbial pathogen concentrations in water resources are usually below the sample limit of detection, this does not ensure, that the water quality complies with a certain required health based target. The aim of this study was therefore to improve the predictability of relevant human pathogenic viruses, i.e. enterovirus and norovirus, in the studied river/floodplain area. This was done by following an innovative calibration strategy based on human-associated microbial source tracking (MST) marker data which were determined following the HF183 TaqMan assay (Green et al. 2011). The MST marker is strongly associated with human faeces and communal sewage, occurring there in numbers by several magnitudes higher than for human enteric pathogens (Mayer et al 2015). The calibrated tool was then evaluated with measured enterovirus concentrations at the PI and in the floodplain river. In the simulation tool the discharges of 5 wastewater treatment plants (WWTPs) were considered with point discharges along a 200 km reach of the Danube river. The MST marker and target virus concentrations at the PI at a certain day were computed based on the concentrations of the previous day, plus the wastewater concentrations times the WWTP discharge divided by the river discharge. A ratio of the river width was also considered, over which the MST marker and virus particles have fully mixed with river water. In the tool, the excrements from recreational visitors frequenting the floodplain area every day were assumed to be homogeneously distributed in the area. A binomial distributed

  14. QMRAcatch - faecal microbial quality of water resources in a river-floodplain area affected by urban sources and recreational visitors

    NASA Astrophysics Data System (ADS)

    Derx, Julia; Schijven, Jack; Sommer, Regina; Kirschner, Alexander; Farnleitner, Andreas H.; Blaschke, Alfred Paul

    2016-04-01

    QMRAcatch, a tool to simulate microbial water quality including infection risk assessment, was previously developed and successfully tested at a Danube river site (Schijven et al. 2015). In the tool concentrations of target faecal microorganisms and viruses (TMVs) are computed at a point of interest (PI) along the main river and the floodplain river at daily intervals for a one year period. Even though faecal microbial pathogen concentrations in water resources are usually below the sample limit of detection, this does not ensure, that the water quality complies with a certain required health based target. The aim of this study was therefore to improve the predictability of relevant human pathogenic viruses, i.e. enterovirus and norovirus, in the studied river/floodplain area. This was done by following an innovative calibration strategy based on human-associated microbial source tracking (MST) marker data which were determined following the HF183 TaqMan assay (Green et al. 2011). The MST marker is strongly associated with human faeces and communal sewage, occurring there in numbers by several magnitudes higher than for human enteric pathogens (Mayer et al 2015). The calibrated tool was then evaluated with measured enterovirus concentrations at the PI and in the floodplain river. In the simulation tool the discharges of 5 wastewater treatment plants (WWTPs) were considered with point discharges along a 200 km reach of the Danube river. The MST marker and target virus concentrations at the PI at a certain day were computed based on the concentrations of the previous day, plus the wastewater concentrations times the WWTP discharge divided by the river discharge. A ratio of the river width was also considered, over which the MST marker and virus particles have fully mixed with river water. In the tool, the excrements from recreational visitors frequenting the floodplain area every day were assumed to be homogeneously distributed in the area. A binomial distributed

  15. Spatial Patterns in Biofilm Diversity across Hierarchical Levels of River-Floodplain Landscapes.

    PubMed

    Peipoch, Marc; Jones, Ryan; Valett, H Maurice

    2015-01-01

    River-floodplain systems are among the most diverse and productive ecosystems, but the effects of biophysical complexity at multiple scales on microbial biodiversity have not been studied. Here, we investigated how the hierarchical organization of river systems (i.e., region, floodplain, zone, habitats, and microhabitats) influences epilithic biofilm community assemblage patterns by characterizing microbial communities using 16S rRNA gene sequence data and analyzing bacterial species distribution across local and regional scales. Results indicate that regional and local environmental filters concurrently sort bacterial species, suggesting that spatial configuration of epilithic biofilms resembles patterns of larger organisms in floodplain ecosystems. Along the hierarchical organization of fluvial systems, floodplains constitute a vector of maximum environmental heterogeneity and consequently act as a major landscape filter for biofilm species. Thus, river basins and associated floodplains may simply reflect very large scale 'patches' within which environmental conditions select for community composition of epilithic biofilms.

  16. Spatial Patterns in Biofilm Diversity across Hierarchical Levels of River-Floodplain Landscapes

    PubMed Central

    Peipoch, Marc; Jones, Ryan; Valett, H. Maurice

    2015-01-01

    River-floodplain systems are among the most diverse and productive ecosystems, but the effects of biophysical complexity at multiple scales on microbial biodiversity have not been studied. Here, we investigated how the hierarchical organization of river systems (i.e., region, floodplain, zone, habitats, and microhabitats) influences epilithic biofilm community assemblage patterns by characterizing microbial communities using 16S rRNA gene sequence data and analyzing bacterial species distribution across local and regional scales. Results indicate that regional and local environmental filters concurrently sort bacterial species, suggesting that spatial configuration of epilithic biofilms resembles patterns of larger organisms in floodplain ecosystems. Along the hierarchical organization of fluvial systems, floodplains constitute a vector of maximum environmental heterogeneity and consequently act as a major landscape filter for biofilm species. Thus, river basins and associated floodplains may simply reflect very large scale ‘patches’ within which environmental conditions select for community composition of epilithic biofilms. PMID:26630382

  17. Spatial Patterns in Biofilm Diversity across Hierarchical Levels of River-Floodplain Landscapes.

    PubMed

    Peipoch, Marc; Jones, Ryan; Valett, H Maurice

    2015-01-01

    River-floodplain systems are among the most diverse and productive ecosystems, but the effects of biophysical complexity at multiple scales on microbial biodiversity have not been studied. Here, we investigated how the hierarchical organization of river systems (i.e., region, floodplain, zone, habitats, and microhabitats) influences epilithic biofilm community assemblage patterns by characterizing microbial communities using 16S rRNA gene sequence data and analyzing bacterial species distribution across local and regional scales. Results indicate that regional and local environmental filters concurrently sort bacterial species, suggesting that spatial configuration of epilithic biofilms resembles patterns of larger organisms in floodplain ecosystems. Along the hierarchical organization of fluvial systems, floodplains constitute a vector of maximum environmental heterogeneity and consequently act as a major landscape filter for biofilm species. Thus, river basins and associated floodplains may simply reflect very large scale 'patches' within which environmental conditions select for community composition of epilithic biofilms. PMID:26630382

  18. NDVI patterns as indicator of morphodynamic activity in the middle Paraná River floodplain

    NASA Astrophysics Data System (ADS)

    Marchetti, Z. Y.; Minotti, P. G.; Ramonell, C. G.; Schivo, F.; Kandus, P.

    2016-01-01

    This work assesses the performance of a 2000-2014 NDVI-MODIS time-series to identify areas of the Paraná River floodplain associated with different morphodynamic areas and hence ecological behavior. From classification procedures we obtained six NDVI patterns (P1 to P6) differing in their mean values, standard deviation, and seasonality. The NDVI patterns are evidence of different situations in terms of elevation, flood dynamics, and vegetation physiognomies: P1 represents water bodies, P2 to P4 cover frequently flooded lowlands colonized by marshy vegetation, and P5 and P6 are placed on middle and high elevations that are less flooded and also are covered by tall vegetation (grassland and forest). Instead of differences among the six NDVI patterns, they showed a spatial arrangement that allowed the identification of two parallel belts; belt I, formed by P2 to P4, is placed close to the Paraná River and its connected branches; while belt II, formed by P5 and mainly P6, appears on the marginal floodplain far away from the main channels. The spatial arrangement of the two belts is similar to limits followed by the morphodynamic areas of the Paraná fluvial system. More than 60% of the surface covered by P2 and P5 corresponds to low morphodynamic areas while nearly 70% of P6 matches with high morphodynamic areas. Through their annual and interannual behavior, spatial arrangement, and relationship with morphodynamic areas, the NDVI patterns allow the interpretation of lateral organization of the Paraná River floodplain. This paper exploits the potential of time-series of NDVI to understand, from a synoptic point of view, the floodplain dynamics by capturing the seasonal and interannual variability of vegetation physiognomies and hydrosedimentological regime along and across the floodplain.

  19. Low Elevation Old Channel Features of the Willamette River Floodplain Support High Subsurface Denitrification Rates

    EPA Science Inventory

    Background/Question/Methods: Large river floodplains are poor nitrate pollution buffers when polluted groundwater moves beneath biogeochemically retentive zones prior to entering the main channel. However, in floodplain regions with extensive backwaters and organic carbon acc...

  20. Organic Carbon Geochemistry in the North-western Black Sea Danube River System

    NASA Astrophysics Data System (ADS)

    Galimov, E. M.; Kodina, L. A.; Zhiltsova, L. I.; Tokarev, V. G.; Vlasova, L. N.; Bogacheva, M. P.; Korobeinik, G. S.; Vaisman, T. I.

    2002-03-01

    The isotopic and chemical composition of organic matter from sediments collected on the north-western shelf of the Black Sea and the Danube River are discussed. The δ 13C distribution pattern in organic carbon from surface sediments (0-1 cm) of the western part of the Black Sea has been established. It reveals a rather complicated picture, reflecting the superposition of several factors: local marine primary productivity, terrestrial input to the Danube River discharge and possible contribution from anaerobic microbial activity. The analysis of organic carbon by a pyrolysis-chromatography technique showed that the H/O indices of organic matter from marine sediments are in correlation with δ 13C values. This is an indication of the mixed origin of the organic carbon in the littoral sediments. However, samples from the zone where H 2S conditions prevail deviate from the correlation line of δ 13C vs H/O indices. We believe that this is due to the contribution of the biomass of chemosynthetic bacteria in the sediments. Thus, we argue that in the Danube-Black Sea system several consecutive zones are distinguished. River discharge delivers organic carbon with δ 13C values from -28 to -26 (PSU is used). Mixing of the land-derived material with autochtonous marine primary production gives δ 13C values of about -26 to -23 for the organic carbon in coastal sediments. On the shelf area, beyond significant influence of both terrestrial and sulphide regime factors, plankton material dominates as a source of organic carbon in sediments. In the hydrogen sulphide zone, chemosynthetic bacteria produce additional amounts of organic matter with hydrogen to oxygen indices similar to those of plankton, but with different isotopic composition, which results in the appearance of relatively isotopically light organic carbon in the deep-sea sediments.

  1. Wetland tree transpiration modified by river-floodplain connectivity

    USGS Publications Warehouse

    Allen, Scott T; Krauss, Ken W.; Cochran, J. Wesley; King, Sammy L.; Keim, Richard F.

    2016-01-01

    Hydrologic connectivity provisions water and nutrient subsidies to floodplain wetlands and may be particularly important in floodplains with seasonal water deficits through its effects on soil moisture. In this study, we measured sapflow in 26 trees of two dominant floodplain forest species (Celtis laevigata and Quercus lyrata) at two hydrologically distinct sites in the lower White River floodplain in Arkansas, USA. Our objective was to investigate how connectivity-driven water table variations affected water use, an indicator of tree function. Meteorological variables (photosynthetically active radiation and vapor pressure deficit) were the dominant controls over water use at both sites; however, water table variations explained some site differences. At the wetter site, highest sapflow rates were during a late-season overbank flooding event, and no flood stress was apparent. At the drier site, sapflow decreased as the water table receded. The late-season flood pulse that resulted in flooding at the wetter site did not affect the water table at the drier site; accordingly, higher water use was not observed at the drier site. The species generally associated with wetter conditions (Q. lyrata) was more positively responsive to the flood pulse. Flood water subsidy lengthened the effective growing season, demonstrating ecological implications of hydrologic connectivity for alleviating water deficits that otherwise reduce function in this humid floodplain wetland.

  2. Biogeography of sulfate-reducing prokaryotes in river floodplains.

    PubMed

    Miletto, Marzia; Loy, Alexander; Antheunisse, A Martijn; Loeb, Roos; Bodelier, Paul L E; Laanbroek, Hendrikus J

    2008-06-01

    In this study, a large-scale field survey was conducted to describe the biogeography of sulfate-reducing prokaryotes (SRPs) in river floodplains. Fingerprints obtained with three methods, i.e. 16S rRNA gene-based oligonucleotide microarray, dsrB-based denaturing gradient gel electrophoresis (DGGE) and polar lipid-derived fatty acid (PLFA) analyses, were used as a proxy to describe the SRPs community diversity. Each set of profiles was subjected to a combined multivariate/correlation analysis in order to compare SRP community profiles and to highlight the environmental variables influencing the SRPs distribution along environmental gradients. Floodplain soils harbored distinct SRP communities displaying biogeographic patterns. Nearly all profiles from the tidal sites consistently separated from the nontidal sites, independently from the screening method and the multivariate statistics used. The distribution of the microarray/DGGE/PLFA-based fingerprints in the principal component plots could be correlated to eight soil variables, i.e. soil organic matter, total nitrogen, total phosphorous and total potassium, and extractable ammonium, nitrate, phosphate and sulfate, as well as seven pore water variables, i.e. phosphate, sulfate, sulfide, chloride, sodium, potassium and magnesium ions. Indication of a salinity- and plant nutrient-dependent distribution of SRPs related to Desulfosarcina, Desulfomonile and Desulfobacter was suggested by microarray, DGGE and PLFA analyses.

  3. Wetland tree transpiration modified by river-floodplain connectivity

    NASA Astrophysics Data System (ADS)

    Allen, Scott T.; Krauss, Ken W.; Cochran, J. Wesley; King, Sammy L.; Keim, Richard F.

    2016-03-01

    Hydrologic connectivity provisions water and nutrient subsidies to floodplain wetlands and may be particularly important in floodplains with seasonal water deficits through its effects on soil moisture. In this study, we measured sapflow in 26 trees of two dominant floodplain forest species (Celtis laevigata and Quercus lyrata) at two hydrologically distinct sites in the lower White River floodplain in Arkansas, USA. Our objective was to investigate how connectivity-driven water table variations affected water use, an indicator of tree function. Meteorological variables (photosynthetically active radiation and vapor pressure deficit) were the dominant controls over water use at both sites; however, water table variations explained some site differences. At the wetter site, highest sapflow rates were during a late-season overbank flooding event, and no flood stress was apparent. At the drier site, sapflow decreased as the water table receded. The late-season flood pulse that resulted in flooding at the wetter site did not affect the water table at the drier site; accordingly, higher water use was not observed at the drier site. The species generally associated with wetter conditions (Q. lyrata) was more positively responsive to the flood pulse. Flood water subsidy lengthened the effective growing season, demonstrating ecological implications of hydrologic connectivity for alleviating water deficits that otherwise reduce function in this humid floodplain wetland.

  4. Avian assemblages in the lower Missouri river floodplain

    USGS Publications Warehouse

    Thogmartin, W.E.; Gallagher, M.; Young, N.; Rohweder, J.J.; Durbian, F.; Knutson, M.G.

    2009-01-01

    Floodplain habitat provides important migration and breeding habitat for birds in the midwestern United States. However, few studies have examined how the avian assemblage changes with different stages of floodplain forest succession in the midwestern United States. In spring and summer from 2002 to 2004, we conducted 839 point counts in wet prairie/forbs fields, 547 point counts in early successional forests, and 434 point counts in mature forests to describe the migrating and breeding bird assemblage in the lower Missouri River floodplain. We recorded 131, 121, and 141 species in the three respective habitats, a number higher than most locations in the midwestern United States and comprising > 15% of all avian species in North America. Avian species diversity generally increased from west to east along the river, differed among land cover classes, but overlapped between seasons (migration and breeding) and years. Wet prairies were particularly important for conservation as there were 20 species of high conservation concern observed, including Dickcissels (Spiza americana). Important species for monitoring biotic integrity included the Northern Harrier (Circus cyaneus) and Bobolink (Dolichonyx oryzivorus) in wet prairie, Bell's Vireo (Vireo bellii) in early successional forest, and Northern Parula (Parula americana) and Prothonotary Warbler (Protonotaria citrea) in mature forest. ?? 2009, The Society of Wetland Scientists.

  5. Water quality of Danube Delta systems: ecological status and prediction using machine-learning algorithms.

    PubMed

    Stoica, C; Camejo, J; Banciu, A; Nita-Lazar, M; Paun, I; Cristofor, S; Pacheco, O R; Guevara, M

    2016-01-01

    Environmental issues have a worldwide impact on water bodies, including the Danube Delta, the largest European wetland. The Water Framework Directive (2000/60/EC) implementation operates toward solving environmental issues from European and national level. As a consequence, the water quality and the biocenosis structure was altered, especially the composition of the macro invertebrate community which is closely related to habitat and substrate heterogeneity. This study aims to assess the ecological status of Southern Branch of the Danube Delta, Saint Gheorghe, using benthic fauna and a computational method as an alternative for monitoring the water quality in real time. The analysis of spatial and temporal variability of unicriterial and multicriterial indices were used to assess the current status of aquatic systems. In addition, chemical status was characterized. Coliform bacteria and several chemical parameters were used to feed machine-learning (ML) algorithms to simulate a real-time classification method. Overall, the assessment of the water bodies indicated a moderate ecological status based on the biological quality elements or a good ecological status based on chemical and ML algorithms criteria.

  6. Water quality of Danube Delta systems: ecological status and prediction using machine-learning algorithms.

    PubMed

    Stoica, C; Camejo, J; Banciu, A; Nita-Lazar, M; Paun, I; Cristofor, S; Pacheco, O R; Guevara, M

    2016-01-01

    Environmental issues have a worldwide impact on water bodies, including the Danube Delta, the largest European wetland. The Water Framework Directive (2000/60/EC) implementation operates toward solving environmental issues from European and national level. As a consequence, the water quality and the biocenosis structure was altered, especially the composition of the macro invertebrate community which is closely related to habitat and substrate heterogeneity. This study aims to assess the ecological status of Southern Branch of the Danube Delta, Saint Gheorghe, using benthic fauna and a computational method as an alternative for monitoring the water quality in real time. The analysis of spatial and temporal variability of unicriterial and multicriterial indices were used to assess the current status of aquatic systems. In addition, chemical status was characterized. Coliform bacteria and several chemical parameters were used to feed machine-learning (ML) algorithms to simulate a real-time classification method. Overall, the assessment of the water bodies indicated a moderate ecological status based on the biological quality elements or a good ecological status based on chemical and ML algorithms criteria. PMID:27191562

  7. Predicting the fate of sediment and pollutants in river floodplains.

    PubMed

    Malmon, Daniel V; Dunne, Thomas; Reneau, Steven L

    2002-05-01

    Geological processes such as erosion and sedimentation redistribute toxic pollutants introduced to the landscape by mining, agriculture, weapons development, and other human activities. A significant portion of these contaminants is insoluble, adsorbing to soils and sediments after being released. Geologists have long understood that much of this sediment is stored in river floodplains, which are increasingly recognized as important nonpoint sources of pollution in rivers. However, the fate of contaminated sediment has generally been analyzed using hydrodynamic models of in-channel processes, ignoring particle exchange with the floodplain. Here, we present a stochastic theory of sediment redistribution in alluvial valley floors that tracks particle-bound pollutants and explicitly considers sediment storage within floodplains. We use the theory to model the future redistribution and radioactive decay of 137Cs currently stored on sediment in floodplains at the Los Alamos National Laboratory (LANL) in New Mexico. Model results indicate that floodplain storage significantly reduces the rate of sediment delivery from upper Los Alamos Canyon, allowing 50% of the 137Cs currently residing in the valley floor to decay radioactively before leaving LANL. A sensitivity analysis shows that the rate of sediment overturn in the valley (and hence, the total amount of radioactive 137Cs predicted to leave LANL) is significantly controlled by the rate of sediment exchange with the floodplain. Our results emphasize that flood plain sedimentation and erosion processes can strongly influence the redistribution of anthropogenic pollutants in fluvial environments. We introduce a new theoretical framework for examining this interaction, which can provide a scientific basis for decision-making in a wide range of river basin management scenarios.

  8. A procedure for incorporating spatial variability in ecological risk assessment of Dutch river floodplains.

    PubMed

    Kooistra, L; Leuven, R S; Nienhuis, P H; Wehrens, R; Buydens, L M

    2001-09-01

    Floodplain soils along the river Rhine in the Netherlands show a large spatial variability in pollutant concentrations. For an accurate ecological risk characterization of the river floodplains, this heterogeneity has to be included into the ecological risk assessment. In this paper a procedure is presented that incorporates spatial components of exposure into the risk assessment by linking geographical information systems (GIS) with models that estimate exposure for the most sensitive species of a floodplain. The procedure uses readily available site-specific data and is applicable to a wide range of locations and floodplain management scenarios. The procedure is applied to estimate exposure risks to metals for a typical foodweb in the Afferdensche and Deestsche Waarden floodplain along the river Waal, the main branch of the Rhine in the Netherands. Spatial variability of pollutants is quantified by overlaying appropriate topographic and soil maps resulting in the definition of homogeneous pollution units. Next to that, GIS is used to include foraging behavior of the exposed terrestrial organisms. Risk estimates from a probabilistic exposure model were used to construct site-specific risk maps for the floodplain. Based on these maps, recommendations for future management of the floodplain can be made that aim at both ecological rehabilitation and an optimal flood defense.

  9. Modelling long-term sediment deposition in a river floodplain during continues flood events

    NASA Astrophysics Data System (ADS)

    Guan, Mingfu; Ahilan, Sangaralingam; Wright, Nigel; Sleigh, P. Andrew

    2015-04-01

    River floodplains act as a form of storage during high discharges in a river. As a floodplain generally has a lower energy environment, sediment aggradation commonly occurs over the period of time, which will reduce the overall storage capacity of the floodplain. Also, in a river system sediments are generally considered as the carrier of pesticides and metal contamination from the upstream catchment. Hence, studying sediment deposition in a floodplain is not only helpful for local flood risk assessment, but also can improve our understanding of the dispersion of contaminants associated with the transfer of sediment between a river and its floodplain. This study adopts a recently updated two-dimensional hydro-morphodynamic model based on the full shallow water equations to model a long-term spatial migration of Johnson Creek, Portland, Oregon and its floodplain. The 500-year, 100-year, 50-year, 10-year, as well as the recorded flood events during 1941-2014 were simulated. Suspended load with three grain-sizes was transported to the river along with the floods. The results indicate that about 30 - 45% of total sediment load is deposited in the floodplain for the studied return period floods. The spatial distribution and amount of short and long-term sediment deposition on the floodplain is demonstrated, and the resulting potential loss of flood storage capacity is analysed and discussed.

  10. Spatial patterns of aquatic habitat richness in the Upper Mississippi River floodplain, USA

    USGS Publications Warehouse

    De Jager, Nathan R.; Rohweder, Jason J.

    2012-01-01

    Interactions among hydrology and geomorphology create shifting mosaics of aquatic habitat patches in large river floodplains (e.g., main and side channels, floodplain lakes, and shallow backwater areas) and the connectivity among these habitat patches underpins high levels of biotic diversity and productivity. However, the diversity and connectivity among the habitats of most floodplain rivers have been negatively impacted by hydrologic and structural modifications that support commercial navigation and control flooding. We therefore tested the hypothesis that the rate of increase in patch richness (# of types) with increasing scale reflects anthropogenic modifications to habitat diversity and connectivity in a large floodplain river, the Upper Mississippi River (UMR). To do this, we calculated the number of aquatic habitat patch types within neighborhoods surrounding each of the ≈19 million 5-m aquatic pixels of the UMR for multiple neighborhood sizes (1–100 ha). For all of the 87 river-reach focal areas we examined, changes in habitat richness (R) with increasing neighborhood length (L, # pixels) were characterized by a fractal-like power function R = Lz (R2 > 0.92 (P z) measures the rate of increase in habitat richness with neighborhood size and is related to a fractal dimension. Variation in z reflected fundamental changes to spatial patterns of aquatic habitat richness in this river system. With only a few exceptions, z exceeded the river-wide average of 0.18 in focal areas where side channels, contiguous floodplain lakes, and contiguous shallow-water areas exceeded 5%, 5%, and 10% of the floodplain respectively. In contrast, z was always less than 0.18 for focal areas where impounded water exceeded 40% of floodplain area. Our results suggest that rehabilitation efforts that target areas with <5% of the floodplain in side channels, <5% in floodplain lakes, and/or <10% in shallow-water areas could improve habitat diversity across multiple scales in the UMR.

  11. Seasonal bioavailability of sediment-associated heavy metals along the Mississippi river floodplain.

    PubMed

    Grabowski, L A; Houpis, J L; Woods, W I; Johnson, K A

    2001-11-01

    A value of simultaneously extracted metal to acid-volatile sulfide (SEM-AVS) can provide important information regarding metal availability in anaerobic sediment. SEM and AVS concentrations were obtained by the cold-acid purge-and-trap technique during spring and summer at six locations along the Mississippi River floodplain. SEM-AVS values and AVS concentrations did not vary significantly between locations during both seasons. AVS concentrations were significantly greater during summer than spring, resulting in significantly lower SEM-AVS values in summer. Total SEM concentrations did not significantly vary between seasons or specific locations. SEM-AVS values were greater than one at each location during both seasons. Sediment metal toxicity was predicted to be absent for benthic organisms along the river floodplain. PMID:11680760

  12. Fluvial Landforms and Landscape Transformations on a Large River Floodplain: Willamette River, Oregon, USA

    NASA Astrophysics Data System (ADS)

    Wallick, R.

    2015-12-01

    Recent detailed mapping of the Willamette River floodplain in northwestern Oregon reveals insights into the floodplain landforms, their formative processes, and historical landscape transformations. Hierarchical mapping classification based mainly upon lidar topography, supplemented by aerial photographs, historical channel and soil maps, and targeted coring of floodplain soils, was carried out for 200 km of the mainstem Willamette River floodplain above Willamette Falls where floodplain landforms mainly reflect fluvial and anthropogenic influences. Stark differences in the character and distribution of floodplain landforms and their underlying stratigraphy give rise to three distinct process regimes along the fluvial portion of the Willamette River. Floodplain surfaces along 60 km of the Upper Willamette River floodplain generally rise 1-2 m above the low-flow water surface and are bisected by complex assemblage of overflow channels and large-amplitude abandoned bends formed by avulsions along this historically multi-thread anastomosing reach. Downstream, the 90 km-long Middle Willamette River between Corvallis and Newburg Pool becomes increasingly entrenched within its floodplain, with floodplains gradually rising up to 8 m above the low flow water surface. These floodplain surfaces are dominated by ridge and swale topography with occasional floodbasins reflecting gradual meander migration and floodplain aggradation. The 50 km-long Newberg Pool is entrenched and confined by Pleistocene Missoula flood deposits and bedrock valley walls. This low-gradient reach extends to the lip of the15-m high Willamette Falls. Historical declines in flood magnitude, bed-material supply, large wood, and bank erodibility result in a more stable modern-day floodplain with narrower active-channel corridor flanked by relict landforms formed by historical flow and sediment regime. Landscape transformations vary across the three process regimes but are greatest along Upper Willamette

  13. Zoogeography, taxonomy, and conservation of West Virginia's Ohio River floodplain crayfishes (Decapoda, Cambaridae).

    PubMed

    Loughman, Zachary J; Simon, Thomas P

    2011-01-01

    The crayfish fauna of West Virginia consists of 23 species and several undescribed taxa. Most survey efforts documenting this fauna have been conducted in lotic waterways throughout the Appalachian plateau, Allegheny Mountains, and Ridge and Valley physiographic provinces. Bottomland forests, swamps, and marshes associated with large river floodplain such as the Ohio River floodplain historically have been under-surveyed in the state. These habitats harbor the richest primary burrowing crayfish fauna in West Virginia, and are worthy of survey efforts. In an effort to fill this void, the crayfish fauna of West Virginia's Ohio River floodplain was surveyed from 2004 through 2009. From this survey, nine species from four genera were documented inhabiting the floodplain. Zoogeography, biology, and conservation status is provided for all nine crayfishes. The dominant genus along the floodplain is Cambarus, which includes Cambarus (Cambarus) carinirostris, Cambarus (Cambarus) bartonii cavatus, Cambarus (Procambarus) robustus and Cambarus (Tubericambarus) thomai. Cambarus (Tubericambarus) thomai is the most prevalent burrowing species occurring along the floodplain. The genus Orconectes consists of two native species, Orconectes (Cambarus) obscurus and Orconectes (Cambarus) sanbornii; and two invasive taxa, Orconectes (Gremicambarus) virilis and Orconectes (Procambarus) rusticus. Orconectes (Cambarus) obscurus has experienced a range extension to the south and occupies streams formerly occupied by Orconectes (Cambarus) sanbornii. Both invasive taxa were allied with anthropogenic habitats and disturbance gradients. The genera Fallicambarus and Procambarus are represented by a single species. Both Fallicambarus (Cambarus) fodiens and Procambarus (Orconectes) acutus are limited to the historic preglacial Marietta River Valley. PMID:21594135

  14. Zoogeography, taxonomy, and conservation of West Virginia’s Ohio River floodplain crayfishes (Decapoda, Cambaridae)

    PubMed Central

    Loughman, Zachary J.; Simon, Thomas P.

    2011-01-01

    Abstract The crayfish fauna of West Virginia consists of 23 species and several undescribed taxa. Most survey efforts documenting this fauna have been conducted in lotic waterways throughout the Appalachian plateau, Allegheny Mountains, and Ridge and Valley physiographic provinces. Bottomland forests, swamps, and marshes associated with large river floodplain such as the Ohio River floodplain historically have been under-surveyed in the state. These habitats harbor the richest primary burrowing crayfish fauna in West Virginia, and are worthy of survey efforts. In an effort to fill this void, the crayfish fauna of West Virginia’s Ohio River floodplain was surveyed from 2004 through 2009. From this survey, nine species from four genera were documented inhabiting the floodplain. Zoogeography, biology, and conservation status is provided for all nine crayfishes. The dominant genus along the floodplain is Cambarus, which includes Cambarus (Cambarus) carinirostris, Cambarus (Cambarus) bartonii cavatus, Cambarus (Procambarus) robustus and Cambarus (Tubericambarus) thomai. Cambarus (Tubericambarus) thomai is the most prevalent burrowing species occurring along the floodplain. The genus Orconectes consists of two native species, Orconectes (Cambarus) obscurus and Orconectes (Cambarus) sanbornii; and two invasive taxa, Orconectes (Gremicambarus) virilis and Orconectes (Procambarus) rusticus. Orconectes (Cambarus) obscurus has experienced a range extension to the south and occupies streams formerly occupied by Orconectes (Cambarus) sanbornii. Both invasive taxa were allied with anthropogenic habitats and disturbance gradients. The genera Fallicambarus and Procambarus are represented by a single species. Both Fallicambarus (Cambarus) fodiens and Procambarus (Orconectes) acutus are limited to the historic preglacial Marietta River Valley. PMID:21594135

  15. Kootenai River Floodplain Ecosystem Operational Loss Assessment, Protection, Mitigation and Rehabilitation, 2007-2008 Annual Report.

    SciTech Connect

    Merz, Norm

    2009-02-18

    The overarching goals of the 'Kootenai River Floodplain Ecosystem Operational Loss Assessment, Protection, Mitigation and Rehabilitation' Project (BPA Project No.2002-011-00) are to: (1) assess abiotic and biotic factors (i.e., geomorphologic, hydrological, aquatic and riparian/floodplain communities) in determining a definitive composition of ecological integrity, (2) develop strategies to assess and mitigate losses of ecosystem functions, and (3) produce a regional operational loss assessment framework. To produce a scientifically defensible, repeatable, and complete assessment tool, KTOI assembled a team of top scientists in the fields of hydrology, hydraulics, ornithology, entomology, statistics, and river ecology, among other expertise. This advisory team is known as the Research Design and Review Team (RDRT). The RDRT scientists drive the review, selection, and adaptive management of the research designs to evaluate the ecologic functions lost due to the operation of federal hydropower facilities. The unique nature of this project (scientific team, newest/best science, adaptive management, assessment of ecological functions, etc.) has been to work in a dynamic RDRT process. In addition to being multidisciplinary, this model KTOI project provides a stark contrast to the sometimes inflexible process (review, re-review, budgets, etc.) of the Columbia River Basin Fish and Wildlife Program. The project RDRT is assembled annually, with subgroups meeting as needed throughout the year to address project issues, analyses, review, and interpretation. Activities of RDRT coordinated and directed the selection of research and assessment methodologies appropriate for the Kootenai River Watershed and potential for regional application in the Columbia River Basin. The entire RDRT continues to meet annually to update and discuss project progress. RDRT Subcontractors work in smaller groups throughout the year to meet project objectives. Determining the extent to which

  16. Removal of river embankments and the modelled effects on river-floodplain hydrodynamics

    NASA Astrophysics Data System (ADS)

    Clilverd, Hannah; Thompson, Julian; Heppell, Kate; Sayer, Carl; Axmacher, Jan

    2015-04-01

    the restored river reach (~400 m), and improved free drainage back to the river. Our results suggest that embankment removal can increase river-floodplain hydrological connectivity to form a more natural wetland ecotone driven by frequent flood disturbance. This has important implications for the planning and management of river restoration projects which aim to enhance floodwater storage, river water quality and floodplain species composition.

  17. Molecular characterization of the species Salvinia (Salviniaceae) from the upper Paraná River floodplain.

    PubMed

    Machado, S A; Oliveira, A V; Fabrin, T M C; Prioli, S M A P; Prioli, A J

    2016-08-12

    The pteridophytes Salvinia minima, S. herzogii, and S. auriculata are among the most abundant aquatic macrophytes in the upper Paraná River floodplain. Since some species have highly similar morphological features, it is very difficult to identify members of this genus to the species level. An indication of this difficulty is a set of poorly differentiated taxa comprising S. auriculata and S. herzogii known as the 'S. auriculata complex', which is found in the Paraná River together with other Salvinia species such as S. biloba and S. molesta. Some authors have reported the existence of inter-species hybrids. Despite the complex Salvinia taxonomy, few genetic studies have been performed on purported species within the genus to resolve this complexity. The present study was conducted to determine useful molecular sequences for the discrimination of Salvinia species of the upper Paraná River floodplain. Molecular data were compared with data of other species of the genus to clarify phylogenetic relationships, employing the nucleotide sequence trnL-trnF from the chloroplast DNA. The results revealed that Salvinia populations in the upper Paraná River floodplain belong to different species and indicated that species of the S. auriculata complex may be distinguished from one another after the division of the S. minima group, corroborating results by other researchers. Although the taxonomic position of S. oblongifolia was clarified, as high closeness between S. oblongifolia and the S. auriculata complex was reported, Salvinia kinship is still not thoroughly established and further investigations in morphology and molecular diversity are required.

  18. A New Hydrogeological Research Site in the Willamette River Floodplain

    EPA Science Inventory

    The Willamette River is a ninth-order tributary of the Columbia which passes through a productive and populous region in northwest Oregon. Where unconstrained by shoreline revetments, the floodplain of this river is a high-energy, dynamic system which supports a variety of ripari...

  19. Influence of dams on river-floodplain dynamics in the Elwha River, Washington

    USGS Publications Warehouse

    Kloehn, K.K.; Beechie, T.J.; Morley, S.A.; Coe, H.J.; Duda, J.J.

    2008-01-01

    The Elwha dam removal project presents an ideal opportunity to study how historic reduction and subsequent restoration of sediment supply alter river-floodplain dynamics in a large, forested river floodplain. We used remote sensing and onsite data collection to establish a historical record of floodplain dynamics and a baseline of current conditions. Analysis was based on four river reaches, three from the Elwha River and the fourth from the East Fork of the Quinault River. We found that the percentage of floodplain surfaces between 25 and 75 years old decreased and the percentage of surfaces >75 years increased in reaches below the Elwha dams. We also found that particle size decreased as downstream distance from dams increased. This trend was evident in both mainstem and side channels. Previous studies have found that removal of the two Elwha dams will initially release fine sediment stored in the reservoirs, then in subsequent decades gravel bed load supply will increase and gradually return to natural levels, aggrading river beds up to 1 m in some areas. We predict the release of fine sediments will initially create bi-modal grain size distributions in reaches downstream of the dams, and eventual recovery of natural sediment supply will significantly increase lateral channel migration and erosion of floodplain surfaces, gradually shifting floodplain age distributions towards younger age classes.

  20. Large scale distribution of bacterial communities in the upper Paraná River floodplain

    PubMed Central

    Chiaramonte, Josiane Barros; Roberto, Maria do Carmo; Pagioro, Thomaz Aurélio

    2014-01-01

    A bacterial community has a central role in nutrient cycle in aquatic habitats. Therefore, it is important to analyze how this community is distributed throughout different locations. Thirty-six different sites in the upper Paraná River floodplain were surveyed to determine the influence of environmental variable in bacterial community composition. The sites are classified as rivers, channels, and floodplain lakes connected or unconnected to the main river channel. The bacterial community structure was analyzed by fluorescent in situ hybridization (FISH) technique, based on frequency of the main domains Bacteria and Archaea, and subdivisions of the phylum Proteobacteria (Alpha-proteobacteria, Beta-proteobacteria, Gamma-proteobacteria) and the Cytophaga-Flavobacterium cluster. It has been demonstrated that the bacterial community differed in density and frequency of the studied groups. And these differences responded to distinct characteristics of the three main rivers of the floodplain as well as to the classification of the environments found in this floodplain. We conclude that dissimilarities in the bacterial community structure are related to environmental heterogeneity, and the limnological variables that most predicted bacterial communities in the upper Paraná River floodplain was total and ammoniacal nitrogen, orthophosphate and chlorophyll-a. PMID:25763022

  1. Using ²¹⁰Pb measurements to estimate sedimentation rates on river floodplains.

    PubMed

    Du, P; Walling, D E

    2012-01-01

    Growing interest in the dynamics of floodplain evolution and the important role of overbank sedimentation on river floodplains as a sediment sink has focused attention on the need to document contemporary and recent rates of overbank sedimentation. The potential for using the fallout radionuclides ¹³⁷Cs and excess ²¹⁰Pb to estimate medium-term (10-10² years) sedimentation rates on river floodplains has attracted increasing attention. Most studies that have successfully used fallout radionuclides for this purpose have focused on the use of ¹³⁷Cs. However, the use of excess ²¹⁰Pb potentially offers a number of advantages over ¹³⁷Cs measurements. Most existing investigations that have used excess ²¹⁰Pb measurements to document sedimentation rates have, however, focused on lakes rather than floodplains and the transfer of the approach, and particularly the models used to estimate the sedimentation rate, to river floodplains involves a number of uncertainties, which require further attention. This contribution reports the results of an investigation of overbank sedimentation rates on the floodplains of several UK rivers. Sediment cores were collected from seven floodplain sites representative of different environmental conditions and located in different areas of England and Wales. Measurements of excess ²¹⁰Pb and ¹³⁷Cs were made on these cores. The ²¹⁰Pb measurements have been used to estimate sedimentation rates and the results obtained by using different models have been compared. The ¹³⁷Cs measurements have also been used to provide an essentially independent time marker for validation purposes. In using the ²¹⁰Pb measurements, particular attention was directed to the problem of obtaining reliable estimates of the supported and excess or unsupported components of the total ²¹⁰Pb activity of sediment samples. Although there was a reasonable degree of consistency between the estimates of sedimentation rate provided by

  2. Methane flux from the Amazon River floodplain - Emissions during rising water

    NASA Technical Reports Server (NTRS)

    Bartlett, Karen B.; Crill, Patrick M.; Bonassi, Jose A.; Richey, Jeffrey E.; Harriss, Robert C.

    1990-01-01

    Methane flux data obtained during a period of high and falling water level in the course of the dry season of 1985 (the Amazon Boundary Layer Experiment, ABLE 2A) and a period of moderate and rising water during the wet season of 1987 (ABLE 2B) were used to characterize the influence of seasonal variations in the vegetation, water column depth, and chemistry, as well as atmospheric dynamics, on the methane flux from the Amazon River floodplain. It was found that the annual estimate of methane from wetlands is identical to the annual estimate made by Matthews and Fung (1987) (both at 111 Tg). However, it was found that peatlands between 50 and 70 N contribute 39 Tg, with the large areas of forested and nonforested bogs making up 37 Tg of this figure, while the figures of Matthews and Fung were 63 and 62 Tg, respectively.

  3. Plant communities in relation to flooding and soil contamination in a lowland Rhine River floodplain.

    PubMed

    Schipper, Aafke M; Lotterman, Kim; Leuven, Rob S E W; Ragas, Ad M J; de Kroon, Hans; Hendriks, A Jan

    2011-01-01

    Using canonical correspondence analysis (CCA), relationships were investigated between plant species composition and flooding characteristics, heavy metal contamination and soil properties in a lowland floodplain of the Rhine River. Floodplain elevation and yearly average flooding duration turned out to be more important for explaining variation in plant species composition than soil heavy metal contamination. Nevertheless, plant species richness and diversity showed a significant decrease with the level of contamination. As single heavy metal concentrations seemed mostly too low for causing phytotoxic effects in plants, this trend is possibly explained by additive effects of multiple contaminants or by the concomitant influences of contamination and non-chemical stressors like flooding. These results suggest that impacts of soil contamination on plants in floodplains could be larger than expected from mere soil concentrations. In general, these findings emphasize the relevance of analyzing effects of toxic substances in concert with the effects of other relevant stressors.

  4. Characterization of redox-related soil microbial communities along a river floodplain continuum by fatty acid methyl ester (FAME) and 16S rRNA genes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Redox states affect substrate availability and energy transformation, and, thus, play a crucial role in regulating soil microbial abundance, diversity, and community structure. We evaluated microbial communities in soils under oxic, intermittent, and anoxic conditions along a river floodplain conti...

  5. Field effects of pollutants in dynamic environments. A case study on earthworm populations in river floodplains contaminated with heavy metals.

    PubMed

    Klok, Chris; Goedhart, Paul W; Vandecasteele, Bart

    2007-05-01

    In industrialized countries river floodplains can be strongly polluted with heavy metals. Published studies on effects of heavy metal pollution on soil invertebrates in floodplains, however, are inconclusive. This is unexpected since studies in other less dynamic environments reported clear effects at even lower levels of pollution. Flooding induces extra variation in invertebrate biomass and abundance which may reduce the probability to detect heavy metal effects. In this paper we combine reported data from studies on river floodplains in The Netherlands and Belgium and statistically analyze the effect of heavy metals on species composition, biomass, density and individual weight of earthworms. Interaction effects of heavy metal stress and flooding are also considered. The results suggest clear effects of zinc and copper on all variables and interaction of heavy metals and flooding for individual weight.

  6. Habitat associations, reproduction and diet of the Guinean tilapia Tilapia guineensis of the Gambia River floodplains.

    PubMed

    Louca, V; Lindsay, S W; Piyapong, C; Lucas, M C

    2010-06-01

    The ecology of the Guinean tilapia Tilapia guineensis a dominant species of the lower Gambia River floodplains and an important food source in parts of West Africa was studied to better understand the threat posed from construction of a barrage across the river. The catch per unit effort (CPUE) of T. guineensis was positively associated with conductivity and dissolved oxygen and negatively associated with water depth and the % vegetation cover. Diet studies indicated that the T. guineensis is primarily an iliophage. The peak of reproduction was at the beginning of the rainy season. CPUE peaked in May, just before the first rains, and subsequently declined, probably reflecting movement into newly flooded habitat. Median size at maturity was 11.6 cm total length, L(T), for females and 12.5 cm L(T) for males. L(T)-frequency analysis indicated several juvenile cohorts as well as very young fish on the floodplains each month, suggesting continuation of reproduction throughout the rainy season. The impending construction of a hydroelectric dam on the Gambia River is likely to affect T. guineensis negatively through anticipated changes in the hydrology of the river.

  7. Exploring field vegetation reflectance as an indicator of soil contamination in river floodplains.

    PubMed

    Kooistra, L; Salas, E A L; Clevers, J G P W; Wehrens, R; Leuven, R S E W; Nienhuis, P H; Buydens, L M C

    2004-01-01

    This study investigated the relation between vegetation reflectance and elevated concentrations of the metals Ni, Cd, Cu, Zn and Pb in river floodplain soils. High-resolution vegetation reflectance spectra in the visible to near-infrared (400-1350 nm) were obtained using a field radiometer. The relations were evaluated using simple linear regression in combination with two spectral vegetation indices: the Difference Vegetation Index (DVI) and the Red-Edge Position (REP). In addition, a multivariate regression approach using partial least squares (PLS) regression was adopted. The three methods achieved comparable results. The best R(2) values for the relation between metals concentrations and vegetation reflectance were obtained for grass vegetation and ranged from 0.50 to 0.73. Herbaceous species displayed a larger deviation from the established relationships, resulting in lower R(2) values and larger cross-validation errors. The results corroborate the potential of hyperspectral remote sensing to contribute to the survey of elevated metal concentrations in floodplain soils under grassland using the spectral response of the vegetation as an indicator. Additional constraints will, however, have to be taken into account, as results are resolution- and location-dependent.

  8. Use of seasonal freshwater wetlands by fishes in a temperate river floodplain

    USGS Publications Warehouse

    Henning, Julie A.; Gresswell, Robert E.; Fleming, Ian A.

    2007-01-01

    This study examined the use of freshwater wetland restoration and enhancement projects (i.e. non-estuarine wetlands subject to seasonal drying) by fish populations. To quantify fish use of freshwater emergent wetlands and assess the effect of wetland enhancement (i.e. addition of water control structures), two enhanced and two unenhanced emergent wetlands were compared, as well as two oxbow habitats within the Chehalis River floodplain. Eighteen fish species were captured using fyke nets and emigrant traps from January to the beginning of June, with the most abundant being three-spined stickleback Gasterosteus aculeatus and Olympic mudminnow Novumbra hubbsi. Coho salmon Oncorhynchus kisutch was the dominant salmonid at all sites. Enhanced wetlands, with their extended hydroperiods, had significantly higher abundances of yearling coho salmon than unenhanced wetlands. Both enhanced and unenhanced emergent wetlands yielded higher abundances of non-game native fishes than oxbow habitats. Oxbow habitats, however, were dominated by coho salmon. Fish survival in the wetland habitats was dependent on emigration to the river before dissolved oxygen concentrations decreased and wetlands became isolated and stranding occurred. This study suggests that wetland enhancement projects with an outlet to the river channel appear to provide fishes with important temporary habitats if they have the opportunity to leave the wetland as dissolved oxygen levels deteriorate.

  9. Isotopic fractionation and trophic position of zooplankton species in the Upper Paraná River floodplain.

    PubMed

    Santana, A R A; Benedito, E; Ducatti, C; Lansac-Tôha, F A

    2011-02-01

    This study aimed to evaluate the isotopic fractionation and trophic position of three zooplankton species (Notodiaptomus amazonicus, Moina minuta and Bosmina hagmanni) in the Upper Paraná River floodplain. We predict that phytoplankton is the main food resource used by these species. Three zooplankton samples and three phytoplankton samples were taken from each sampling site, with three to four samples collected for each species. The number of individuals for samples varied according to the body size: from 100 to 130 individuals for Notodiaptomus amazonicus; 150 to 200 for Moina minuta; and from 250 to 300 for Bosmina hagmanni. The isotopic values for δ13C and δ15N were determined using mass spectrophotometer. The isotopic fractionation of 13C was performed according to the relationship Δ = δ13C zooplankton - δ13C phytoplankton. To determine the possible trophic position of these species, we used the expression TL = (δ15N zooplankton - δ15N phytoplankton)/Δ+ 1. The species showed high variation in isotopic fractionation and in trophic position in the different environments. We verified that the species use other food resources in addition to phytoplankton. The elucidation and understanding of the trophic position of the organisms based on stable isotopic analysis offers complementary information to traditional techniques. This analysis helps explain the flow of matter and energy in the food chain of floodplain aquatic environments as well as trace the trophic relationships involved in the ecological roles and strategies of distinct species. PMID:21437401

  10. Habitat associations, reproduction and diet of the Guinean tilapia Tilapia guineensis of the Gambia River floodplains.

    PubMed

    Louca, V; Lindsay, S W; Piyapong, C; Lucas, M C

    2010-06-01

    The ecology of the Guinean tilapia Tilapia guineensis a dominant species of the lower Gambia River floodplains and an important food source in parts of West Africa was studied to better understand the threat posed from construction of a barrage across the river. The catch per unit effort (CPUE) of T. guineensis was positively associated with conductivity and dissolved oxygen and negatively associated with water depth and the % vegetation cover. Diet studies indicated that the T. guineensis is primarily an iliophage. The peak of reproduction was at the beginning of the rainy season. CPUE peaked in May, just before the first rains, and subsequently declined, probably reflecting movement into newly flooded habitat. Median size at maturity was 11.6 cm total length, L(T), for females and 12.5 cm L(T) for males. L(T)-frequency analysis indicated several juvenile cohorts as well as very young fish on the floodplains each month, suggesting continuation of reproduction throughout the rainy season. The impending construction of a hydroelectric dam on the Gambia River is likely to affect T. guineensis negatively through anticipated changes in the hydrology of the river. PMID:20557603

  11. Nutrient dynamics in the lower Mississippi river floodplain: Comparing present and historic hydrologic conditions

    USGS Publications Warehouse

    Schramm, H.L.; Cox, M.S.; Tietjen, T.E.; Ezell, A.W.

    2009-01-01

    Alterations to the lower Mississippi River-floodplain ecosystem to facilitate commercial navigation and to reduce flooding of agricultural lands and communities in the historic floodplain have changed the hydrologic regime. As a result, the flood pulse usually has a lower water level, is of shorter duration, has colder water temperatures, and a smaller area of floodplain is inundated. Using average hydrologic conditions and water temperatures, we used established nitrogen and phosphorus processes in soils, an aquatic ecosystem model, and fish bioenergetic models to provide approximations of nitrogen and phosphorus flux in Mississippi River flood waters for the present conditions of a 2-month (mid-March to mid-May) flood pulse and for a 3-month (mid-March to mid-June), historic flood pulse. We estimated that the soils and aquatic biota can remove or sequester 542 and 976 kg nitrogen ha-1 during the present and historic hydrologic conditions, respectively. Phosphorus, on the other hand, will be added to the water largely as a result of anaerobic soil conditions but moderated by biological uptake by aquatic biota during both present and historic hydrologic conditions. The floodplain and associated water bodies may provide an important management opportunity for reducing downstream transport of nitrogen in Mississippi River waters. ?? 2009, The Society of Wetland Scientists.

  12. Hydrological response in the Danube lower basin to some internal and external forcing factors of the climate system

    NASA Astrophysics Data System (ADS)

    Mares, Ileana; Dobrica, Venera; Demetrescu, Crisan; Mares, Constantin

    2016-04-01

    The precipitation in the Danube upper and middle basin is the main indicator for the Danube discharge at the entry in the lower basin. Along with precipitation, from the category of internal factors, in the first stage, we tried to find other predictors from the fields of temperature, pressure and geopotential. In the second phase, we considered external factors, taking into account the indices of solar/geomagnetic activity, represented by Wolf numbers, 10.7cm solar flux/aa geomagnetic index. In the Danube upper and middle basin, were considered fields of precipitation (PP), and temperatures (T) at 15 meteorological stations. The large-scale atmospheric circulation was quantified by Greenland-Balkan-Oscillation index (GBOI), North Atlantic Oscillation index and by blocking indices. The hydrological state in the Danube lower basin was represented by the discharge at the Orsova station. To estimate the discharge response in the Danube lower basin to various factors, developments in EOFs, cross correlations, power spectra, filters, composite maps were achieved. For the atmospheric variables, taken simultaneously, the most significant results (confidence level of 95%) are related to the predictors, considering the difference between standardized temperatures and precipitation (TPP), except for winter season, when the best predictors are PC1 of precipitation field and GBOI. In order to see the predictive hydrological response to the considered predictors, the correlative analyses with some lags were achieved. The significant results, were obtained for the winter/spring variables (PC1-precipitation and TPP), which can be considered good predictors for spring/summer discharge in the Danube lower basin. The hydrological response to the solar/ geomagnetic activity is given with a delay of two and three years. Due to the important signal of GBOI in the Danube basin precipitation in winter (correlation coefficient of 0.83), a stochastic modeling was performed between GBOI and

  13. Edge effects are important in supporting beetle biodiversity in a gravel-bed river floodplain.

    PubMed

    Langhans, Simone D; Tockner, Klement

    2014-01-01

    Understanding complex, dynamic, and diverse ecosystems is essential for developing sound management and conservation strategies. Gravel-bed river floodplains are composed of an interlinked mosaic of aquatic and terrestrial habitats hosting a diverse, specialized, and endangered fauna. Therefore, they serve as excellent models to investigate the biodiversity of multiple ecotones and related edge effects. In this study, we investigated the abundance, composition, richness, and conservation status of beetle assemblages at varying sediment depth (0, 0.1, 0.6 and 1.1 m), distance from the channel (1, 5, 20, and 60-100 m, and 5 m within the riparian forest), and time of the year (February-November) across a 200 m-wide gravel bar at the near-natural Tagliamento River (Italy), to detect edge effects in four floodplain ecotones: aquatic-terrestrial, forest-active floodplain, sediment-air, and sediment-groundwater. We used conventional pitfall traps and novel tube traps to sample beetles comparably on the sediment surface and within the unsaturated sediments. We found a total of 308 beetle species (including 87 of conservation concern) that showed multiple, significant positive edge effects across the floodplain ecotones, mainly driven by spatial heterogeneity: Total and red list beetle abundance and richness peaked on the sediment surface, at channel margins, and at the edge of the riparian forest. All ecotones possessed edge/habitat specialists. Most red list species occurred on the sediment surface, including five species previously considered extinct--yet two of these species occurred in higher densities in the unsaturated sediments. Conservation and management efforts along gravel-bed rivers must therefore promote a dynamic flow and sediment regime to create and maintain habitat heterogeneity and ecotone diversity, which support a unique and high biodiversity. PMID:25545280

  14. Edge Effects Are Important in Supporting Beetle Biodiversity in a Gravel-Bed River Floodplain

    PubMed Central

    Langhans, Simone D.; Tockner, Klement

    2014-01-01

    Understanding complex, dynamic, and diverse ecosystems is essential for developing sound management and conservation strategies. Gravel-bed river floodplains are composed of an interlinked mosaic of aquatic and terrestrial habitats hosting a diverse, specialized, and endangered fauna. Therefore, they serve as excellent models to investigate the biodiversity of multiple ecotones and related edge effects. In this study, we investigated the abundance, composition, richness, and conservation status of beetle assemblages at varying sediment depth (0, 0.1, 0.6 and 1.1 m), distance from the channel (1, 5, 20, and 60–100 m, and 5 m within the riparian forest), and time of the year (February–November) across a 200 m-wide gravel bar at the near-natural Tagliamento River (Italy), to detect edge effects in four floodplain ecotones: aquatic-terrestrial, forest-active floodplain, sediment-air, and sediment-groundwater. We used conventional pitfall traps and novel tube traps to sample beetles comparably on the sediment surface and within the unsaturated sediments. We found a total of 308 beetle species (including 87 of conservation concern) that showed multiple, significant positive edge effects across the floodplain ecotones, mainly driven by spatial heterogeneity: Total and red list beetle abundance and richness peaked on the sediment surface, at channel margins, and at the edge of the riparian forest. All ecotones possessed edge/habitat specialists. Most red list species occurred on the sediment surface, including five species previously considered extinct – yet two of these species occurred in higher densities in the unsaturated sediments. Conservation and management efforts along gravel-bed rivers must therefore promote a dynamic flow and sediment regime to create and maintain habitat heterogeneity and ecotone diversity, which support a unique and high biodiversity. PMID:25545280

  15. Edge effects are important in supporting beetle biodiversity in a gravel-bed river floodplain.

    PubMed

    Langhans, Simone D; Tockner, Klement

    2014-01-01

    Understanding complex, dynamic, and diverse ecosystems is essential for developing sound management and conservation strategies. Gravel-bed river floodplains are composed of an interlinked mosaic of aquatic and terrestrial habitats hosting a diverse, specialized, and endangered fauna. Therefore, they serve as excellent models to investigate the biodiversity of multiple ecotones and related edge effects. In this study, we investigated the abundance, composition, richness, and conservation status of beetle assemblages at varying sediment depth (0, 0.1, 0.6 and 1.1 m), distance from the channel (1, 5, 20, and 60-100 m, and 5 m within the riparian forest), and time of the year (February-November) across a 200 m-wide gravel bar at the near-natural Tagliamento River (Italy), to detect edge effects in four floodplain ecotones: aquatic-terrestrial, forest-active floodplain, sediment-air, and sediment-groundwater. We used conventional pitfall traps and novel tube traps to sample beetles comparably on the sediment surface and within the unsaturated sediments. We found a total of 308 beetle species (including 87 of conservation concern) that showed multiple, significant positive edge effects across the floodplain ecotones, mainly driven by spatial heterogeneity: Total and red list beetle abundance and richness peaked on the sediment surface, at channel margins, and at the edge of the riparian forest. All ecotones possessed edge/habitat specialists. Most red list species occurred on the sediment surface, including five species previously considered extinct--yet two of these species occurred in higher densities in the unsaturated sediments. Conservation and management efforts along gravel-bed rivers must therefore promote a dynamic flow and sediment regime to create and maintain habitat heterogeneity and ecotone diversity, which support a unique and high biodiversity.

  16. How livestock and flooding mediate the ecological integrity of working forests in Amazon River floodplains.

    PubMed

    Lucas, Christine M; Sheikh, Pervaze; Gagnon, Paul R; Mcgrath, David G

    2016-01-01

    The contribution of working forests to tropical conservation and development depends upon the maintenance of ecological integrity under ongoing land use. Assessment of ecological integrity requires an understanding of the structure, composition, and function and major drivers that govern their variability. Working forests in tropical river floodplains provide many goods and services, yet the data on the ecological processes that sustain these services is scant. In flooded forests of riverside Amazonian communities, we established 46 0.1-ha plots varying in flood duration, use by cattle and water buffalo, and time since agricultural abandonment (30-90 yr). We monitored three aspects of ecological integrity (stand structure, species composition, and dynamics of trees and seedlings) to evaluate the impacts of different trajectories of livestock activity (alleviation, stasis, and intensification) over nine years. Negative effects of livestock intensification were solely evident in the forest understory, and plots alleviated from past heavy disturbance increased in seedling density but had higher abundance of thorny species than plots maintaining low activity. Stand structure, dynamics, and tree species composition were strongly influenced by the natural pulse of seasonal floods, such that the defining characteristics of integrity were dependent upon flood duration (3-200 d). Forests with prolonged floods ≥ 140 d had not only lower species richness but also lower rates of recruitment and species turnover relative to forests with short floods <70 d. Overall, the combined effects of livestock intensification and prolonged flooding hindered forest regeneration, but overall forest integrity was largely related to the hydrological regime and age. Given this disjunction between factors mediating canopy and understory integrity, we present a subset of metrics for regeneration and recruitment to distinguish forest condition by livestock trajectory. Although our study design

  17. The significance of sediment contamination in the Elbe River floodplain (Czech Republic)

    NASA Astrophysics Data System (ADS)

    Chalupová, Dagmar; Janský, Bohumír; Langhammer, Jakub; Šobr, Miroslav; Jiři, Medek; Král, Stanislav; Jiřinec, Petr; Kaiglova, Jana; Černý, Michal; Žáček, Miroslav; Leontovyčova, Drahomíra; Halířová, Jarmila

    2015-04-01

    The abstract brings the information about the research that was focused on anthropogenic pollution of river and lake sediments in the middle course of the Elbe River (Czech Republic). The main aim was to identify and to evaluate the significance of old polluted sediments in the river and its side structures (old meanders, cut lakes, oxbow lakes) between Hradec Králové and Mělník (confluence with the Moldau River) and to assess the risk coming from the remobilization of the contaminated matter. The Elbe River floodplain has been highly inhabited since the Middle Ages, and, especially in the 20th century, major industrial plants were founded here. Since that time, the anthropogenic load of the river and it`s floodplain has grown. Although the contaminants bound to the sediment particles are usually stable, the main risk is coming from the fact that under changes in hydrological regime and water quality (floods, changes in pH, redox-potential, presence of complex substances etc.), the pollution can be released and remobilized again. The most endangered areas are: the surroundings of Pardubice (chemical factory Synthesia, Inc.; refinery PARAMO), and Neratovice (chemical factory Spolana, Inc.). The chemical factories situated close to these towns represented the most problematic polluters of the Elbe River especially during 2nd half of 20th century. In the research, the main attention was aimed at subaquatic sediments of selected cut lakes situated in the vicinity of the above mentioned sources of pollution. To describe the outreach of contamination, several further fluvial lakes were taken into account too. Sediment sampling was carried out from boats on lakes and with the help of drilling rig in the floodplain. Gained sediment cores were divided into several parts which were analysed separately. Chemical analyses included substances identified by ICPER (International Commission for the Protection of the Elbe River) as well as chemicals considered as significant in

  18. Hydrodynamic Modeling of Flood Dynamics and Restoration Potential of Lower Missouri River Floodplains

    NASA Astrophysics Data System (ADS)

    Lindner, G. A.

    2012-12-01

    Lower Missouri River floodplains have the potential to provide multiple ecosystem services including agricultural production, floodwater storage, nutrient processing, and provision of habitats. In this research, a 2-dimensional hydrodynamic model of a representative looped floodplain bottom of approximately 20 km is utilized to explore how floodplain inundation contributes to ecosystem benefits and costs. High resolution 2-dimensional hydrodynamic modeling provides insights into the way velocities, flood stages, residence times, and transported constituents (sediment, nutrients, and fish larvae, for example) are affected by levee geometry, floodplain vegetation patterns, and flood magnitude and duration. The utility of 2-dimensional numerical hydraulic models to represent the channel and floodplain are demonstrated at a scale relevant to understanding processes that control channel/floodplain dynamics. The sensitivity of model response to alternative land use scenarios, including levee setbacks and variable overbank roughness, is quantified using hydraulic parameters such as velocity, water level, conveyance, and residence time. The 2-dimensional models are calibrated to existing 1-dimensional modeling solutions and field measurements of water surface from 1993 and 2007 for the 2-year, 5-year, and 10-year recurrence intervals. Calibration runs with current levee configurations are matched to approximately ±0.1 meters. Simulations of alternative land use scenarios demonstrate the tradeoffs between ecological restoration and flood risk reductions. Levee setbacks with low hydraulic roughness associated with traditional row crop agriculture on the floodplains have the greatest potential for flood stage reductions, while native plant communities with higher roughness can negate the effects of the setbacks by increasing water levels due to enhanced frictional resistance. Residence times, which are presumed to be related to ecosystem services, demonstrate increasingly

  19. How livestock and flooding mediate the ecological integrity of working forests in Amazon River floodplains.

    PubMed

    Lucas, Christine M; Sheikh, Pervaze; Gagnon, Paul R; Mcgrath, David G

    2016-01-01

    The contribution of working forests to tropical conservation and development depends upon the maintenance of ecological integrity under ongoing land use. Assessment of ecological integrity requires an understanding of the structure, composition, and function and major drivers that govern their variability. Working forests in tropical river floodplains provide many goods and services, yet the data on the ecological processes that sustain these services is scant. In flooded forests of riverside Amazonian communities, we established 46 0.1-ha plots varying in flood duration, use by cattle and water buffalo, and time since agricultural abandonment (30-90 yr). We monitored three aspects of ecological integrity (stand structure, species composition, and dynamics of trees and seedlings) to evaluate the impacts of different trajectories of livestock activity (alleviation, stasis, and intensification) over nine years. Negative effects of livestock intensification were solely evident in the forest understory, and plots alleviated from past heavy disturbance increased in seedling density but had higher abundance of thorny species than plots maintaining low activity. Stand structure, dynamics, and tree species composition were strongly influenced by the natural pulse of seasonal floods, such that the defining characteristics of integrity were dependent upon flood duration (3-200 d). Forests with prolonged floods ≥ 140 d had not only lower species richness but also lower rates of recruitment and species turnover relative to forests with short floods <70 d. Overall, the combined effects of livestock intensification and prolonged flooding hindered forest regeneration, but overall forest integrity was largely related to the hydrological regime and age. Given this disjunction between factors mediating canopy and understory integrity, we present a subset of metrics for regeneration and recruitment to distinguish forest condition by livestock trajectory. Although our study design

  20. Modeling the influence of environmental heterogeneity on heavy metal exposure concentrations for terrestrial vertebrates in river floodplains.

    PubMed

    Schipper, Aafke M; Loos, Mark; Ragas, Ad M J; Lopes, João P C; Nolte, Boris T; Wijnhoven, Sander; Leuven, Rob S E W

    2008-04-01

    To analyze the influence of environmental heterogeneity on heavy metal exposure concentrations for terrestrial vertebrates in river floodplains, a spatially explicit exposure model has been constructed (SpaCE-model: Spatially explicit cumulative exposure model). This model simulates the environmental use of individual organisms by selecting model cells to be foraged in within a multicelled, heterogeneous landscape. Exposure durations and exposure concentrations are calculated for the selected cells, whereby exposure concentrations are dependent on the availability and contaminant concentrations of different diet items in each cell. The model was applied to a selection of 10 terrestrial vertebrate species, including six small mammalian and four top predator species. It was parameterized for cadmium contamination in a 285-ha, embanked floodplain area along the Rhine River in The Netherlands. Simulations of 1,000 individuals for each species resulted in intraspecies variation in exposure concentrations of between 11 and 39%, with the smallest values generally corresponding to the species with the largest home ranges. Comparison of the model results with cadmium concentrations measured in four of the species from the study area showed that the predicted variation accounted for 12 to 16% of the variation in the measurements. This indicates that environmental heterogeneity governs a minor part of the variation in metal exposure concentrations that can actually be observed in river floodplains.

  1. Macrophytes in the Upper Paraná River floodplain: checklist and comparison with other large South American wetlands.

    PubMed

    Ferreira, Fernando Alves; Mormul, Roger Paulo; Thomaz, Sidinei Magela; Pott, Arnildo; Pott, Vali Joana

    2011-06-01

    Neotropical aquatic ecosystems have a rich aquatic flora. In this report, we have listed the aquatic flora of various habitats of the upper Paraná River floodplain by compiling data from literature and records of our own continuous collections conducted during the period 2007-2009. Our main purposes were to assess the macrophyte richness in the Paraná floodplain, to compare it with other South American wetlands and to assess whether the number of species recorded in South American inventories has already reached an asymptote. We recorded a total of 153 species of macrophytes in the Upper Paraná River floodplain, belonging to 100 genera and 47 families. In our comparative analysis, a clear floristic split from other South American wetlands was shown, except for the Pantanal, which is the closest wetland to the Paraná floodplain and, therefore, could be considered a floristic extension of the Pantanal. The species accumulation curve provides evidence that sampling efforts should be reinforced in order to compile a macrophyte flora census for South America. The high dissimilarity among South American wetlands, together with the lack of an asymptote in our species accumulation curve, indicates that the sampling effort needs to be increased to account for the actual species richness of macrophytes in this region.

  2. Biodiversity of zooplankton communities in the Upper Paraná River floodplain: interannual variation from long-term studies.

    PubMed

    Lansac-Tôha, F A; Bonecker, C C; Velho, L F M; Simões, N R; Dias, J D; Alves, G M; Takahashi, E M

    2009-06-01

    We investigated the effect of interannual variation of hydrosedimentological regime and connectivity on the zooplankton biodiversity in the Upper Paraná River floodplain. Zooplankton samplings were undertaken between 2000 and 2007, in different environments of the floodplain, including connected and isolated floodplain lakes, backwaters, rivers and channels. The zooplankton included 541 species. Rotifers showed the highest species richness and abundance. Among the zooplankton species, 71 represent new occurrence records for the floodplain. The species accumulation curve showed a continuous increase in gamma diversity, demonstrating the importance of long-term research for accurate knowledge of biodiversity in heterogeneous and dynamic ecosystems, such as the floodplains. Interannual beta diversity among studied years indicated a lesser alteration in community composition in 2001, when a long limnophase period was observed. In most of the environments, the highest species richness values were related to the greatest flooding amplitudes. Flooding amplitude, which is associated with connectivity, favors faunal exchange amongst the environments and between the pelagic and littoral zones. This explains the occurrence of both planktonic and non-planktonic species within the community. On the other hand, mean zooplankton abundance values were higher when a long isolation period occurred. Differences between the potamophase and limnophase amplitude associated with connectivity among the environments were the most important factors for the structure and dynamics of the zooplankton community in the Upper Paraná River floodplain.

  3. Bacterioplankton features and its relations with doc characteristics and other limnological variables in Paraná river floodplain environments (PR/MS-Brazil)

    PubMed Central

    Teixeira, Mariana Carolina; Santana, Natália Fernanda; de Azevedo, Júlio César Rodrigues; Pagioro, Thomaz Aurélio

    2011-01-01

    Since the introduction of the Microbial Loop concept, many studies aimed to explain the role of bacterioplankton and dissolved organic carbon (DOC) in aquatic ecosystems. Paraná River floodplain system is a very complex environment where these subjects were little explored. The aim of this work was to characterize bacterial community in terms of density, biomass and biovolume in some water bodies of this floodplain and to verify its temporal variation and its relation with some limnological variables, including some indicators of DOC quality, obtained through Ultraviolet-visible (UV-VIS) and fluorescence spectroscopic analysis. Bacterial density, biomass and biovolume are similar to those from other freshwater environments and both density and biomass were higher in the period with less rain. The limnological and spectroscopic features that showed any relation with bacterioplankton were the concentrations of N-NH4 and P-PO4, water transparency, and some indicators of DOC quality and origin. The analysis of these relations showed a possible competition between bacterioplankton and phytoplankton for inorganic nutrients and that the DOC used by bacterioplankton is labile and probably from aquatic macrophytes. PMID:24031705

  4. The interplay between tectonics, sediment dynamics and gateways evolution in the Danube system from the Pannonian Basin to the western Black Sea.

    PubMed

    Matenco, Liviu; Munteanu, Ioan; ter Borgh, Marten; Stanica, Adrian; Tilita, Marius; Lericolais, Gilles; Dinu, Corneliu; Oaie, Gheorghe

    2016-02-01

    Understanding the natural evolution of a river-delta-sea system is important to develop a strong scientific basis for efficient integrated management plans. The distribution of sediment fluxes is linked with the natural connection between sediment source areas situated in uplifting mountain chains and deposition in plains, deltas and, ultimately, in the capturing oceans and seas. The Danube River-western Black Sea is one of the most active European systems in terms of sediment re-distribution that poses significant societal challenges. We aim to derive the tectonic and sedimentological background of human-induced changes in this system and discuss their interplay. This is obtained by analysing the tectonic and associated vertical movements, the evolution of relevant basins and the key events affecting sediment routing and deposition. The analysis of the main source and sink areas is focused in particular on the Miocene evolution of the Carpatho-Balkanides, Dinarides and their sedimentary basins including the western Black Sea. The vertical movements of mountains chains created the main moments of basin connectivity observed in the Danube system. Their timing and effects are observed in sediments deposited in the vicinity of gateways, such as the transition between the Pannonian/Transylvanian and Dacian basins and between the Dacian Basin and western Black Sea. The results demonstrate the importance of understanding threshold conditions driving rapid basins connectivity changes superposed over the longer time scale of tectonic-induced vertical movements associated with background erosion and sedimentation. The spatial and temporal scale of such processes is contrastingly different and challenging. The long-term patterns interact with recent or anthropogenic induced modifications in the natural system and may result in rapid changes at threshold conditions that can be quantified and predicted. Their understanding is critical because of frequent occurrence during

  5. Flooding along Danube River

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Heavy rains in Central and Eastern Europe over the past few weeks have led to some of the worst flooding the region has witnessed in over 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 Danube River and its tributaries was taken on August 19, 2002, by the Moderate Resolution Imaging Spectroradiometer (MODIS), flying aboard NASA's Terra satellite. Budapest, the capital of Hungary, sits just south of the large bend in the river at the top of the image. Here the water reached levels not seen since 1965. Fortunately, the riverbanks are lined with 33-foot retainer walls throughout the city, so it did not face the same fate as Dresden or Prague along the Elbe River. But as one can see, the floodwaters hit many rural areas farther south. As last reported, the water was receding along the Danube. Credit: Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC.

  6. Do beaver dams reduce habitat connectivity and salmon productivity in expansive river floodplains?

    PubMed

    Malison, Rachel L; Kuzishchin, Kirill V; Stanford, Jack A

    2016-01-01

    Beaver have expanded in their native habitats throughout the northern hemisphere in recent decades following reductions in trapping and reintroduction efforts. Beaver have the potential to strongly influence salmon populations in the side channels of large alluvial rivers by building dams that create pond complexes. Pond habitat may improve salmon productivity or the presence of dams may reduce productivity if dams limit habitat connectivity and inhibit fish passage. Our intent in this paper is to contrast the habitat use and production of juvenile salmon on expansive floodplains of two geomorphically similar salmon rivers: the Kol River in Kamchatka, Russia (no beavers) and the Kwethluk River in Alaska (abundant beavers), and thereby provide a case study on how beavers may influence salmonids in large floodplain rivers. We examined important rearing habitats in each floodplain, including springbrooks, beaver ponds, beaver-influenced springbrooks, and shallow shorelines of the river channel. Juvenile coho salmon dominated fish assemblages in all habitats in both rivers but other species were present. Salmon density was similar in all habitat types in the Kol, but in the Kwethluk coho and Chinook densities were 3-12× lower in mid- and late-successional beaver ponds than in springbrook and main channel habitats. In the Kol, coho condition (length: weight ratios) was similar among habitats, but Chinook condition was highest in orthofluvial springbrooks. In the Kwethluk, Chinook condition was similar among habitats, but coho condition was lowest in main channel versus other habitats (0.89 vs. 0.99-1.10). Densities of juvenile salmon were extremely low in beaver ponds located behind numerous dams in the orthofluvial zone of the Kwethluk River floodplain, whereas juvenile salmon were abundant in habitats throughout the entire floodplain in the Kol River. If beavers were not present on the Kwethluk, floodplain habitats would be fully interconnected and theoretically

  7. Do beaver dams reduce habitat connectivity and salmon productivity in expansive river floodplains?

    PubMed Central

    Kuzishchin, Kirill V.; Stanford, Jack A.

    2016-01-01

    Beaver have expanded in their native habitats throughout the northern hemisphere in recent decades following reductions in trapping and reintroduction efforts. Beaver have the potential to strongly influence salmon populations in the side channels of large alluvial rivers by building dams that create pond complexes. Pond habitat may improve salmon productivity or the presence of dams may reduce productivity if dams limit habitat connectivity and inhibit fish passage. Our intent in this paper is to contrast the habitat use and production of juvenile salmon on expansive floodplains of two geomorphically similar salmon rivers: the Kol River in Kamchatka, Russia (no beavers) and the Kwethluk River in Alaska (abundant beavers), and thereby provide a case study on how beavers may influence salmonids in large floodplain rivers. We examined important rearing habitats in each floodplain, including springbrooks, beaver ponds, beaver-influenced springbrooks, and shallow shorelines of the river channel. Juvenile coho salmon dominated fish assemblages in all habitats in both rivers but other species were present. Salmon density was similar in all habitat types in the Kol, but in the Kwethluk coho and Chinook densities were 3–12× lower in mid- and late-successional beaver ponds than in springbrook and main channel habitats. In the Kol, coho condition (length: weight ratios) was similar among habitats, but Chinook condition was highest in orthofluvial springbrooks. In the Kwethluk, Chinook condition was similar among habitats, but coho condition was lowest in main channel versus other habitats (0.89 vs. 0.99–1.10). Densities of juvenile salmon were extremely low in beaver ponds located behind numerous dams in the orthofluvial zone of the Kwethluk River floodplain, whereas juvenile salmon were abundant in habitats throughout the entire floodplain in the Kol River. If beavers were not present on the Kwethluk, floodplain habitats would be fully interconnected and theoretically

  8. Forest Types in the Lower Suwannee River Floodplain, Florida?-A Report and Interactive Map

    USGS Publications Warehouse

    Darst, M.R.; Light, H.M.; Lewis, L.J.; Sepulveda, A.A.

    2003-01-01

    A map of forest types in the lower Suwannee River floodplain, Florida, was created during a study conducted from 1996 to 2000 by the U.S. Geological Survey in cooperation with the Suwannee River Water Management District. The map is presented with this report on a compact disc with interactive viewing software. The forest map can be used by scientists for ecological studies in the floodplain based on land cover types and by landowners and management personnel making land use decisions. The study area is the 10-year floodplain of the lower Suwannee River from its confluence with the Santa Fe River to the lower limit of forests near the Gulf of Mexico. The floodplain is divided into three reaches: riverine (non-tidal), upper tidal, and lower tidal, due to changes in hydrology, vegetation, and soils with proximity to the coast. The 10-year floodplain covers about 21,170 hectares; nearly 88 percent of this area (18,580 hectares) is mapped as 14 major forest types. Approximately 29 percent (5,319 hectares) of these forests have been altered by agriculture or development. About 75 percent of the area of major forest types (13,994 hectares) is wetland forests and about 25 percent (4,586 hectares) is upland forests. Tidal wetland forests (8,955 hectares) cover a much greater area than riverine wetland forests (5,039 hectares). Oak/pine upland forests are present in the riverine and upper tidal reaches of the floodplain on elevations that are inundated only briefly during the highest floods. High bottomland hardwoods are present on the higher levees, ridges, and flats of the riverine reach where soils are usually sandy. Low bottomland hardwood forests are present in the riverine reach on swamp margins and low levees and flats that are flooded continuously for several weeks or longer every 1 to 3 years. Riverine swamps are present in the lowest and wettest areas of the non-tidal floodplain that are either inundated or saturated most of the time. Upper tidal bottomland

  9. Do beaver dams reduce habitat connectivity and salmon productivity in expansive river floodplains?

    PubMed

    Malison, Rachel L; Kuzishchin, Kirill V; Stanford, Jack A

    2016-01-01

    Beaver have expanded in their native habitats throughout the northern hemisphere in recent decades following reductions in trapping and reintroduction efforts. Beaver have the potential to strongly influence salmon populations in the side channels of large alluvial rivers by building dams that create pond complexes. Pond habitat may improve salmon productivity or the presence of dams may reduce productivity if dams limit habitat connectivity and inhibit fish passage. Our intent in this paper is to contrast the habitat use and production of juvenile salmon on expansive floodplains of two geomorphically similar salmon rivers: the Kol River in Kamchatka, Russia (no beavers) and the Kwethluk River in Alaska (abundant beavers), and thereby provide a case study on how beavers may influence salmonids in large floodplain rivers. We examined important rearing habitats in each floodplain, including springbrooks, beaver ponds, beaver-influenced springbrooks, and shallow shorelines of the river channel. Juvenile coho salmon dominated fish assemblages in all habitats in both rivers but other species were present. Salmon density was similar in all habitat types in the Kol, but in the Kwethluk coho and Chinook densities were 3-12× lower in mid- and late-successional beaver ponds than in springbrook and main channel habitats. In the Kol, coho condition (length: weight ratios) was similar among habitats, but Chinook condition was highest in orthofluvial springbrooks. In the Kwethluk, Chinook condition was similar among habitats, but coho condition was lowest in main channel versus other habitats (0.89 vs. 0.99-1.10). Densities of juvenile salmon were extremely low in beaver ponds located behind numerous dams in the orthofluvial zone of the Kwethluk River floodplain, whereas juvenile salmon were abundant in habitats throughout the entire floodplain in the Kol River. If beavers were not present on the Kwethluk, floodplain habitats would be fully interconnected and theoretically

  10. Do beaver dams reduce habitat connectivity and salmon productivity in expansive river floodplains?

    PubMed Central

    Kuzishchin, Kirill V.; Stanford, Jack A.

    2016-01-01

    Beaver have expanded in their native habitats throughout the northern hemisphere in recent decades following reductions in trapping and reintroduction efforts. Beaver have the potential to strongly influence salmon populations in the side channels of large alluvial rivers by building dams that create pond complexes. Pond habitat may improve salmon productivity or the presence of dams may reduce productivity if dams limit habitat connectivity and inhibit fish passage. Our intent in this paper is to contrast the habitat use and production of juvenile salmon on expansive floodplains of two geomorphically similar salmon rivers: the Kol River in Kamchatka, Russia (no beavers) and the Kwethluk River in Alaska (abundant beavers), and thereby provide a case study on how beavers may influence salmonids in large floodplain rivers. We examined important rearing habitats in each floodplain, including springbrooks, beaver ponds, beaver-influenced springbrooks, and shallow shorelines of the river channel. Juvenile coho salmon dominated fish assemblages in all habitats in both rivers but other species were present. Salmon density was similar in all habitat types in the Kol, but in the Kwethluk coho and Chinook densities were 3–12× lower in mid- and late-successional beaver ponds than in springbrook and main channel habitats. In the Kol, coho condition (length: weight ratios) was similar among habitats, but Chinook condition was highest in orthofluvial springbrooks. In the Kwethluk, Chinook condition was similar among habitats, but coho condition was lowest in main channel versus other habitats (0.89 vs. 0.99–1.10). Densities of juvenile salmon were extremely low in beaver ponds located behind numerous dams in the orthofluvial zone of the Kwethluk River floodplain, whereas juvenile salmon were abundant in habitats throughout the entire floodplain in the Kol River. If beavers were not present on the Kwethluk, floodplain habitats would be fully interconnected and theoretically

  11. Development of a Web-based GIS monitoring and environmental assessment system for the Black Sea: application in the Danube Delta area.

    PubMed

    Tziavos, Ilias N; Alexandridis, Thomas K; Aleksandrov, Borys; Andrianopoulos, Agamemnon; Doukas, Ioannis D; Grigoras, Ion; Grigoriadis, Vassilios N; Papadopoulou, Ioanna D; Savvaidis, Paraskevas; Stergioudis, Argyrios; Teodorof, Liliana; Vergos, Georgios S; Vorobyova, Lyudmila; Zalidis, Georgios C

    2016-08-01

    In this paper, the development of a Web-based GIS system for the monitoring and assessment of the Black Sea is presented. The integrated multilevel system is based on the combination of terrestrial and satellite Earth observation data through the technological assets provided by innovative information tools and facilities. The key component of the system is a unified, easy to update geodatabase including a wide range of appropriately selected environmental parameters. The collection procedure of current and historical data along with the methods employed for their processing in three test areas of the current study are extensively discussed, and special attention is given to the overall design and structure of the developed geodatabase. Furthermore, the information system includes a decision support component (DSC) which allows assessment and effective management of a wide range of heterogeneous data and environmental parameters within an appropriately designed and well-tested methodology. The DSC provides simplified and straightforward results based on a classification procedure, thus contributing to a monitoring system not only for experts but for auxiliary staff as well. The examples of the system's functionality that are presented highlight its usability as well as the assistance that is provided to the decision maker. The given examples emphasize on the Danube Delta area; however, the information layers of the integrated system can be expanded in the future to cover other regions, thus contributing to the development of an environmental monitoring system for the entire Black Sea. PMID:27491819

  12. Development of a Web-based GIS monitoring and environmental assessment system for the Black Sea: application in the Danube Delta area.

    PubMed

    Tziavos, Ilias N; Alexandridis, Thomas K; Aleksandrov, Borys; Andrianopoulos, Agamemnon; Doukas, Ioannis D; Grigoras, Ion; Grigoriadis, Vassilios N; Papadopoulou, Ioanna D; Savvaidis, Paraskevas; Stergioudis, Argyrios; Teodorof, Liliana; Vergos, Georgios S; Vorobyova, Lyudmila; Zalidis, Georgios C

    2016-08-01

    In this paper, the development of a Web-based GIS system for the monitoring and assessment of the Black Sea is presented. The integrated multilevel system is based on the combination of terrestrial and satellite Earth observation data through the technological assets provided by innovative information tools and facilities. The key component of the system is a unified, easy to update geodatabase including a wide range of appropriately selected environmental parameters. The collection procedure of current and historical data along with the methods employed for their processing in three test areas of the current study are extensively discussed, and special attention is given to the overall design and structure of the developed geodatabase. Furthermore, the information system includes a decision support component (DSC) which allows assessment and effective management of a wide range of heterogeneous data and environmental parameters within an appropriately designed and well-tested methodology. The DSC provides simplified and straightforward results based on a classification procedure, thus contributing to a monitoring system not only for experts but for auxiliary staff as well. The examples of the system's functionality that are presented highlight its usability as well as the assistance that is provided to the decision maker. The given examples emphasize on the Danube Delta area; however, the information layers of the integrated system can be expanded in the future to cover other regions, thus contributing to the development of an environmental monitoring system for the entire Black Sea.

  13. Hydrologic conditions, habitat characteristics, and occurrence of fishes in the Apalachicola River floodplain, Florida; second annual report of progress, October 1993-September 1994

    USGS Publications Warehouse

    Light, Helen M.; Darst, Melanie R.; Grubbs, J.W.

    1995-01-01

    This report describes progress and interim results of the second year of a 4-year study. The purpose of the 4-year study is to describe aquatic habitat types in the Apalachicola River floodplain and quantify the amount of habitat inundated by the river at various stages. Final results will be used to determine possible effects of altered flows on floodplain habitats and their associated fish communities. The study is being conducted by the U.S. Geological Survey in cooperation with the Northwest Florida Water Management District as part of a comprehensive study of water needs throughout two large river basins in Florida, Georgia, and Alabama. By the end of the second year, approxi- mately 80 to 90 percent of field data collection was completed. Water levels at 56 floodplain and main channel locations at study sites were read numerous times during low water and once or twice during high water. Rating curves estimating the relationship between stage at a floodplain site and flow of the Apalachicola River at Chattahoochee are presented for 3 sites in the upper river. Elevation, substrate type, and amount of vegetative structure were described at 27 cross sections representing eight different floodplain tributary types at upper, middle, and lower river study sites. A summary of substrate and structure information from all cross sections is presented. Substrate and structure characteristics of floodplain habitats inundated when river flow was at record low flow, mean annual low flow, and mean flow are described for 3 cross sections in the upper river. Digital coverage of high-altitude infra-red aerial photography was processed for use in a Geographic Information System which will be used to map aquatic habitats in the third year of the study. A summary of the literature on fish utilization of floodplain habitats is described. Eighty-one percent of the species collected in the main channel of the Apalachicola River are known to occur in floodplain habitats of eastern

  14. Effects of flooding on ion exchange rates in an Upper Mississippi River floodplain forest impacted by herbivory, invasion, and restoration

    USGS Publications Warehouse

    Kreiling, Rebecca; DeJager, Nathan R.; Whitney Swanson,; Eric A. Strauss,; Meredith Thomsen,

    2015-01-01

    We examined effects of flooding on supply rates of 14 nutrients in floodplain areas invaded by Phalaris arundinacea (reed canarygrass), areas restored to young successional forests (browsed by white-tailed deer and unbrowsed), and remnant mature forests in the Upper Mississippi River floodplain. Plant Root Simulator ion-exchange probes were deployed for four separate 28-day periods. The first deployment occurred during flooded conditions, while the three subsequent deployments were conducted during progressively drier periods. Time after flooding corresponded with increases in NO3 −-N, K+ and Zn+2, decreases in H2PO4 −-P, Fe+3, Mn+2, and B(OH)4-B, a decrease followed by an increase in NH4 +-N, Ca+2, Mg+2 and Al+3, and an increase followed by a decrease for SO4 −2-S. Plant community type had weak to no effects on nutrient supply rates compared to the stronger effects of flooding duration. Our results suggest that seasonal dynamics in floodplain nutrient availability are similarly driven by flood pulses in different community types. However, reed canarygrass invasion has potential to increase availability of some nutrients, while restoration of forest cover may promote recovery of nutrient availability to that observed in reference mature forests.

  15. Quantifying the mass transfer from mountain ranges to deposition in sedimentary basins: Source to sink studies in the Danube Basin-Black Sea system

    NASA Astrophysics Data System (ADS)

    Matenco, Liviu; Andriessen, Paul

    2013-04-01

    A source to sink system describes the natural link between mountains, plains and deltas, by analysing the (re)distribution of material at shallow crustal depth and at the Earth's surface, exploring the links between coupled tectonic and surface processes. Sediment fluxes are the product of erosion and movement of material in and from sources (mountains), the transport and movement of sediments and solutes by river systems to the plains, and deposition and storage in sink zones. The ESF-EUROCORES TOPO-EUROPE SourceSink programme is a fully integrated research effort to significantly advance our predictive capabilities on the quantitative analyses of coupled active and past drainage systems by means of step-wise 4D reconstructions of sediments mass transfer, integrating geophysics, geology, geomorphology, state of the art high-resolution dating, and numerical and analogue modelling. The area selected for this programme is the Danube River Basin-Black Sea source to sink system, a world-class natural laboratory that is uniquely suited in the heart of Europe's topography, covering almost half of its surface, providing opportunities for excellent field sites to study in integration surface and subsurface data that cover the complete chain of source, carrier and sink. Quantifying and modelling the complete system in relation to the controlling parameters has resulted in significant understanding of forcing factors and linking temporal and spatial scales across multiple orogen and basin systems. This research has provided the opportunity to widen the geographical scope to other natural scenarios, where a number of mountain chains with similar geodynamic genesis separate sedimentary basins with comparable evolution.

  16. Further development and implementation of the DIWA distributed hydrological model-based integrated hydroinformatics system in the Danube River Basin for supporting decision making in water management

    NASA Astrophysics Data System (ADS)

    Szabó, J. A.; Réti, G. Z.; Tóth, T.

    2012-04-01

    developed integrated model has two basic pillars: the DIWA (DIstributed WAtershed) hydrologic, and the well-known HEC-RAS hydraulic models. The DIWA is a dynamic water-balance model that distributed both in space and its parameters, and which was developed along combined principles but its mostly based on physical foundations. According to the philosophy of the distributed model approach the catchment is divided into basic elements, cells where the basin characteristics, parameters, physical properties, and the boundary conditions are applied in the centre of the cell, and the cell is supposed to be homogenous between the block boundaries. The neighbouring cells are connected to each other according to runoff hierarchy (local drain direction). Applying the hydrological mass balance and the adequate dynamic equations to these cells, the result is a distributed hydrological model on a continuous, 3D gridded domain. For calculating the water level as well the HEC-RASS hydraulic model has been embedded into DIWA model. In this integration the DIWA model provides the upper boundary conditions for HEC-RAS, and then HEC-RAS provides the water levels along the lowland parts of the river-network. In this presentation, our recently developed integrated hydroinformatics system and its implementation for the middle-upper part of the Danube River Basin will be reported. Following an outline of the backgrounds, an overview on the DIWA and the integrated model-system will be given. The implementation of this integrated hydroinformatics system in the Danube River Basin will also be presented, including a summary of the developed 1km resolution geo-dataset for the modelling. Then some demonstrative results of the use of the pre-calibrated system will be discussed. Finally, an outline of the future steps of the development will be discussed.

  17. Synergies between Danube Floodplain revitalization, flood risk mapping and spatial planning

    NASA Astrophysics Data System (ADS)

    Nichersu, Iulian; Marin, Eugenia; Mierla, Marian; Sela, Florentina; Nichersu, Iuliana; Trifanov, Cristian

    2014-05-01

    The Danube River must be considered more than a subject of hydraulics. Together with its major riverbed and flooded meadow, represents a very complex ecosystem that provides habitat for a very rich flora and fauna, and also a support for the socio-economical activities. During time, the ecological balance of Danube River has suffered alteration processes because of continuously development of human society. In the alteration process of the Danube have been destroyed dominating natural systems and created instead industrial structures with economical purpose such as navigation, hydro-energy, agriculture, harbors that are damaging the Danube River by losing the floodplains and natural morphological structures, determining the Danube Floodplain to struggle with increasing flood risks and actual floods in the last few years. Because the Danube was recently channelized and enclosed by dikes, there is hardly room for the reduction of peak flow during rainy periods or for the development of nature along the river. Due to climate change and large-scale deforestation, these peak flows occur not only more frequently, but they also carry a greater volume of water over a shorter time, as seen during the summers of 2004 and 2005 and spring 2006, 2010 when a large part of the region flooded and required large-scale evacuations. The catastrophic flood events in the Danube Basin in particular reveal the vulnerability of our society against extreme natural events. With the increase of population and industrialization, the settling areas and land use activities spread in floodplain areas seeming protected or hardly affected. Hence, the Romanian Danube Floodplain has been the subject of three major research projects: "Ecological and economical restoration of Lower Danube Floodplain - Romanian Sector", "Danube River revitalization" within SEE project 'Danube River Network of Protected Areas" and "Beneficiaries and flood risk assessment in Danube Floodplain". The synergic objective of

  18. Patterns of Ground Water Movement in a Portion of the Willamette River Floodplain, Oregon

    EPA Science Inventory

    In reaches unconstrained by revetments, the Willamette River and its floodplain along its lowland mainstem is a continually evolving system. Several channel reconstruction and restoration projects have been implemented or planned in order to obtain beneficial services along the r...

  19. Spatial scaling of core and dominant forest cover in the Upper Mississippi and Illinois River floodplains, USA

    USGS Publications Warehouse

    De Jager, Nathan R.; Rohweder, Jason J.

    2011-01-01

    Different organisms respond to spatial structure in different terms and across different spatial scales. As a consequence, efforts to reverse habitat loss and fragmentation through strategic habitat restoration ought to account for the different habitat density and scale requirements of various taxonomic groups. Here, we estimated the local density of floodplain forest surrounding each of ~20 million 10-m forested pixels of the Upper Mississippi and Illinois River floodplains by using moving windows of multiple sizes (1–100 ha). We further identified forest pixels that met two local density thresholds: 'core' forest pixels were nested in a 100% (unfragmented) forested window and 'dominant' forest pixels were those nested in a >60% forested window. Finally, we fit two scaling functions to declines in the proportion of forest cover meeting these criteria with increasing window length for 107 management-relevant focal areas: a power function (i.e. self-similar, fractal-like scaling) and an exponential decay function (fractal dimension depends on scale). The exponential decay function consistently explained more variation in changes to the proportion of forest meeting both the 'core' and 'dominant' criteria with increasing window length than did the power function, suggesting that elevation, soil type, hydrology, and human land use constrain these forest types to a limited range of scales. To examine these scales, we transformed the decay constants to measures of the distance at which the probability of forest meeting the 'core' and 'dominant' criteria was cut in half (S 1/2, m). S 1/2 for core forest was typically between ~55 and ~95 m depending on location along the river, indicating that core forest cover is restricted to extremely fine scales. In contrast, half of all dominant forest cover was lost at scales that were typically between ~525 and 750 m, but S 1/2 was as long as 1,800 m. S 1/2 is a simple measure that (1) condenses information derived from multi

  20. Adsorption and desorption of arsenic to aquifer sediment on the Red River floodplain at Nam Du, Vietnam

    NASA Astrophysics Data System (ADS)

    Thi Hoa Mai, Nguyen; Postma, Dieke; Thi Kim Trang, Pham; Jessen, Søren; Hung Viet, Pham; Larsen, Flemming

    2014-10-01

    The adsorption of arsenic onto aquifer sediment from the Red River floodplain, Vietnam, was determined in a series of batch experiments. Due to water supply pumping, river water infiltrates into the aquifer at the field site and has leached the uppermost aquifer sediments. The leached sediments remain anoxic but contain little reactive arsenic and iron, and are used in our experiments. The adsorption and desorption experiments were carried out by addition or removal of arsenic from the aqueous phase in sediment suspensions under strictly anoxic conditions. Also the effects of HCO3, Fe(II), PO4 and Si on arsenic adsorption were explored. The results show much stronger adsorption of As(V) as compared to As(III), full reversibility for As(III) adsorption and less so for As(V). The presence or absence of HCO3 did not influence arsenic adsorption. Fe(II) enhanced As(V) sorption but did not influence the adsorption of As(III) in any way. During simultaneous adsorption of As(III) and Fe(II), As(III) was found to be fully desorbable while Fe(II) was completely irreversibly adsorbed and clearly the two sorption processes are uncoupled. Phosphate was the only solute that significantly could displace As(III) from the sediment surface. Compiling literature data on arsenic adsorption to aquifer sediment in Vietnam and Bangladesh revealed As(III) isotherms to be almost identical regardless of the nature of the sediment or the site of sampling. In contrast, there was a large variation in As(V) adsorption isotherms between studies. A tentative conclusion is that As(III) and As(V) are not adsorbing onto the same sediment surface sites. The adsorption behavior of arsenic onto aquifer sediments and synthetic Fe-oxides is compared. Particularly, the much stronger adsorption of As(V) than of As(III) onto Red River as well as on most Bangladesh aquifer sediments, indicates that the perception that arsenic, phosphate and other species compete for the same surface sites of iron oxides in

  1. Living in highly dynamic polluted river floodplains, do contaminants contribute to population and community effects?

    PubMed

    Klok, Chris; Kraak, Michiel H S

    2008-12-01

    The aim of this paper was to collect evidence for the effects of contaminants on biota in a highly dynamic river Rhine floodplain. To this purpose we reviewed the results of circa 10 studies performed in this floodplain. The floodplain was contaminated with elevated levels of cadmium, copper, PAHs, and PCBs and high levels of zinc which were at some sites above legislative values. The results showed that the present contaminants were accumulated by the floodplain inhabiting organisms, but meanwhile population and community effects were ambiguous. Only for the mayfly Ephoron virgo clear effects were detected at the level of the single floodplain. The absence of clear population and community effects is puzzling since at lower contaminant concentrations adverse effects were detected in other environments. Factors that may mask toxic effects include flooding and food quality and quantity. We conclude that given the site specific conditions, being an open, eutrophic system with a highly dynamic flooding pattern, assessment of the contribution of toxicants to observed population density or biomass and community composition requires 1] an increase in number of replicates; 2] a larger scale of investigation and 3] comparison to stable systems with comparable contamination levels.

  2. Flood variability recorded by crevasse-splay sedimentation of large river floodplains

    NASA Astrophysics Data System (ADS)

    Hackney, C. R.; Darby, S. E.; Aalto, R. E.; Parsons, D. R.; Clayton, A.; Schwendel, A.; Leyland, J.; Nicholas, A. P.; Best, J.

    2015-12-01

    During rapid rise flood events, crevasse-splay complexes are a key conduit through which sediment and water are passed from the main channel onto the floodplain, particularly for large rivers. These crevasse-splay systems may therefore be key loci of floodplain sedimentation, as well as conditioning the location of avulsions. As such they may preserve climatic signals within the depositional record of large alluvial rivers. Despite recent advances in our capabilities to model the development and evolution of these systems, our understanding of the passage, storage and reworking of water and sediment across them remains relatively poor. A key limitation concerns the point that, since floodplain topography is a first-order control on the hydrodynamics of crevasse-splays, publicly available topographic data sets (e.g. SRTM, ASTER) are currently unable to resolve key processes at the necessary spatial resolution. Here we employ Structure-from-Motion (SfM) on low-level aerial photography to obtain high-resolution (3m grid cell) georectified topographic data (horizontal error = 0.02 m; vertical error = 0.2 m) for a representative crevasse-splay complex (27 km2) located along the Mekong River, Cambodia. We use the coupled hydrodynamic and morphodynamic model, Delft-3D to simulate sedimentation patterns for a series of idealised and observed rapid-rise flood events. We model floodplain deposition and erosion and validate simulated spatial and temporal variations against observed patterns of sedimentation determined through analysis of 210Pb geochronology of a network of floodplain cores and in-situ, post-event surface scrapings.

  3. Tritium/3He dating of river infiltration: an example from the Danube in the Szigetkoz Area, Hungary

    USGS Publications Warehouse

    Stute, M.; Deak, J.; Revesz, K.; Böhlke, J.K.; Deseo, E.; Weppernig, R.; Schlosser, P.

    1997-01-01

    3H, 3He, 4He, and Ne data were obtained from a shallow ground-water system being recharged by bank infiltration from the Danube River in northwestern Hungary. After correting for excess air, 4He and Ne concentrations reflect a recharge temperature of about 9?? C, close to the mean annual temperature of the Danube (10.4?? C). Values of 3H plus 3Hetrit, ("initial tritium") as a function of the tritium/3He age are consistent with time series measurements of tritium in the Danube. Tritium/3He ages increase linearly as a function of distance from the Danube along ground-water flow lines. A horizontal flow velocity of about 530 m yr-1 was derived from the age gradient. Most of the deviations between measured Danube tritium data and ground-water tritium/3He data can be explained by dispersive mixing.

  4. Past and predicted future changes in the land cover of the Upper Mississippi River floodplain, USA

    USGS Publications Warehouse

    De Jager, N. R.; Rohweder, J.J.; Nelson, J.C.

    2013-01-01

    This study provides one historical and two alternative future contexts for evaluating land cover modifications within the Upper Mississippi River (UMR) floodplain. Given previously documented changes in land use, river engineering, restoration efforts and hydro-climatic changes within the UMR basin and floodplain, we wanted to know which of these changes are the most important determinants of current and projected future floodplain land cover. We used Geographic Information System data covering approximately 37% of the UMR floodplain (3232 km2) for ca 1890 (pre-lock and dam) and three contemporary periods (1975, 1989 and 2000) across which river restoration actions have increased and hydro-climatic changes have occurred. We further developed two 50-year future scenarios from the spatially dependent land cover transitions that occurred from 1975 to 1989 (scenario A) and from 1989 to 2000 (scenario B) using Markov models.Land cover composition of the UMR did not change significantly from 1975 to 2000, indicating that current land cover continues to reflect historical modifications that support agricultural production and commercial navigation despite some floodplain restoration efforts and variation in river discharge. Projected future land cover composition based on scenario A was not significantly different from the land cover for 1975, 1989 or 2000 but was different from the land cover of scenario B, which was also different from all other periods. Scenario B forecasts transition of some forest and marsh habitat to open water by the year 2050 for some portions of the northern river and projects that some agricultural lands will transition to open water in the southern portion of the river. Future floodplain management and restoration planning efforts in the UMR should consider the potential consequences of continued shifts in hydro-climatic conditions that may occur as a result of climate change and the potential effects on floodplain land cover.

  5. Biogeochemical patchiness, geomorphic feedbacks, and flow connectivity in river-floodplain corridors

    NASA Astrophysics Data System (ADS)

    Larsen, L.; Harvey, J. W.; Maglio, M.

    2014-12-01

    Ecogeomorphology is the understanding of the signature of life on landforms. The field has advanced primarily on the basis of studies of physical-biological feedbacks between vegetation, flow, and sediment transport. However, biogeochemistry also has the potential to exert strong feedback on life and landforms. This potential is particularly high in tropical and subtropical regions, where vegetation is often phosphorus (P)-limited. Aquatic landscapes are essentially closed systems for P—in contrast to nitrogen—and the transport of P primarily in particulate form can establish a tight feedback between biogeochemical and geomorphic processes in these regions. Here we examine mechanisms that can contribute to spatial patterning, or patchiness, in nutrient distributions and vegetated landforms. We evaluated hypotheses for evapotranspiration focusing, differential hydrologic exchange, and particulate nutrient redistribution mechanisms to explain spatial patterns of P retention and function of the Everglades. Based on field measurements in sloughs and on slightly higher and more densely vegetated ridges and field-grounded mechanistic models, we quantified P fluxes attributable to the three mechanisms. Findings suggest that evapotranspiration focusing is not a driver of Everglades nutrient retention nor of ridge and slough patterning. Instead, differential hydrologic exchange, driven by different periods of groundwater-surface water connectivity across topographic elements, is the primary cause of elevated P concentrations on ridges and can completely explain interpatch differences in long-term P accumulation rates. With historical flow velocities, which were an order of magnitude higher than at present, particulate P redistribution would have further increased the interpatch difference in long-term P retention rates nearly twofold, with potential consequences for landscape pattern development. In conclusion, differential hydrologic exchange and particulate nutrient

  6. Floodplain Sedimentation in Vegetated Areas of the Elwha River Floodplain, 2012-2014

    NASA Astrophysics Data System (ADS)

    Lauer, J. W.; Polka, J.

    2014-12-01

    field-based sedimentation measurements and to develop a reach-wide estimate of overall fine sediment accumulation on the floodplain. Our CAESAR runs, which are performed for the entire post-dam removal period, produce rich 2-D representations of velocity and bed texture that should be useful to other researchers studying this system.

  7. Flood effects on efflux and net production of nitrous oxide in river floodplain soils

    NASA Astrophysics Data System (ADS)

    Riaz, Muhammad; Bruderer, Christian; Niklaus, Pascal A.; Luster, Jörg

    2016-04-01

    Floodplain soils are often rich in nutrients and exhibit high spatial heterogeneity in terms of geomorphology, soil environmental conditions and substrate availability for processes involved in carbon and nutrient cycling. In addition, fluctuating water tables lead to temporally changing redox conditions. In such systems, there are ideal conditions for the occurrence of hot spots and moments of nitrous oxide emissions, a potent greenhouse gas. The factors that govern the spatial heterogeneity and dynamics of N2O formation in floodplain soils and the surface efflux of this gas are not fully understood. A particular issue is the contribution of N2O formation in the subsoil to surface efflux. We studied this question in the floodplain of a restored section of the Thur river (NE Switzerland) which is characterized by a flashy flow regime. As a consequence, the floodplain soils are unsaturated most of the time. We showed earlier that saturation during flood pulses leads to short phases of generally anoxic conditions followed by a drying phase with anoxic conditions within aggregates and oxic conditions in larger soil pores. The latter conditions are conducive for spatially closely-coupled nitrification-denitrification and related hot moments of nitrous oxide formation. In a floodplain zone characterized by about one meter of young, sandy sediments, that are mostly covered by the tall grass Phalaris arundinacea, we measured at several time points before and after a small flood event N2O surface efflux with the closed-chamber method, and assessed N2O concentrations in the soil air at four different depths using gas-permeable tubings. In addition, we calculated the N2O diffusivity in the soil from Radon diffusivity. The latter was estimated in-situ from the recovery of Radon concentration in the gas-permeable tubings after purging with ambient air. All these data were then used to calculate net N2O production rates at different soil depths with the gradient method. In

  8. Geomorphic and vegetation processes of the Willamette River floodplain, Oregon: current understanding and unanswered science questions

    USGS Publications Warehouse

    Wallick, J. Rose; Jones, Krista L.; O'Connor, Jim E.; Keith, Mackenzie K.; Hulse, David; Gregory, Stanley V.

    2013-01-01

    decrease bed-material supply by an unknown amount because they limit bank erosion and entrainment of stored sediment. The rivers, geomorphic floodplain, and vegetation within the study area have changed noticeably in response to the alterations in floods and coarse sediment and wood transport. Widespread decreases have occurred in the rates of meander migration and avulsions and the number and diversity of landforms such as gravel bars, islands, and side channels. Dynamic and, in some cases, multi-thread river segments have become stable, single-thread channels. Preliminary observations suggest that forest area has increased within the active channel, further reducing the area of unvegetated gravel bars. Alterations to floods and sediment transport and ongoing channel, floodplain, and vegetation responses result in a modern Willamette River Basin. Here, the floodplain influenced by the modern flow and sediment regimes, or the functional floodplain, is narrower and inset with the broader and older geomorphic floodplain. The functional floodplain is flanked by higher elevation relict floodplain features that are no longer inundated by modern floods. The corridor of present- day active channel surfaces is narrower, enabling riparian vegetation to establish on formerly active gravel bar surfaces. The modern Willamette River Basin with its fundamental changes in the flood, sediment transport, and large wood regimes has implications for future habitat conditions. System-wide future trends probably include narrower floodplains and a lower diversity of landforms and habitats along the Willamette River and its major tributaries compared to historical patterns and today. Furthermore, specific conditions and future trends will probably vary between geologically stable, anthropogenically stable, and dynamic reaches. The middle and lower segments of the Willamette River are geologically stable, whereas the South Santiam and Middle Fork Willamette Rivers were historically dynamic, but

  9. Ground-cover vegetation in wetland forests of the lower Suwannee River floodplain, Florida, and potential impacts of flow reductions

    USGS Publications Warehouse

    Darst, Melanie R.; Light, Helen M.; Lewis, Lori J.

    2002-01-01

    Ground-cover vegetation was surveyed in wetland forests in the lower Suwannee River floodplain, Florida, in a study conducted by the U.S. Geological Survey in cooperation with the Suwannee River Water Management District from 1996 to 1999. Increased water use in the basin, supplied primarily from ground water, could reduce ground-water discharge to the river and flows in the lower Suwannee River. Many of the 282 ground-cover species found in wetland forests of the floodplain have distributions that are related to flow-dependent hydrologic characteristics of forest types, and their distributions would change if flows were reduced. Overall species diversity in the floodplain might decrease, and the composition of ground-cover vegetation in all forest types might change with flow reductions. The study area included forests within the 10-year floodplain of the lower Suwannee River from its confluence with the Santa Fe River to the lower limit of forests near the Gulf of Mexico. The floodplain is divided into three reaches (riverine, upper tidal, and lower tidal) due to variations in hydrology, vegetation, and soils with proximity to the coast. The riverine (non-tidal) reach had the greatest number of total species (203) and species unique to that reach (81). Mitchella repens, Toxicodendron radicans, and Axonopus furcatus were the most frequently dominant species in riverine bottomland hardwoods. Free-floating aquatic species, such as Spirodela punctata and Lemna valdiviana, were the dominant species in the wettest riverine swamps. The upper tidal reach had the lowest number of total species (116), only two species unique to that reach, and the lowest density of ground cover (26 percent). Panicum commutatum and Crinum americanum were frequent dominant species in upper tidal forests. The lower tidal reach had the highest ground-cover density (43 percent) and the second highest number of total species (183) and number of species unique to that reach (55). Saururus cernuus

  10. Application of the authigenic 10Be/9Be dating method to Late Miocene-Pliocene sequences in the northern Danube Basin (Pannonian Basin System): Confirmation of heterochronous evolution of sedimentary environments

    NASA Astrophysics Data System (ADS)

    Šujan, Michal; Braucher, Régis; Kováč, Michal; Bourlès, Didier L.; Rybár, Samuel; Guillou, Valéry; Hudáčková, Natália

    2016-02-01

    Authigenic 10Be/9Be dating method was applied to lacustrine, deltaic and alluvial sequences of the northern Danube Basin (Pannonian Basin System), to bridge the insufficiency of geochronological data for the Late Miocene to Pliocene period. The measurements of 51 samples (both lacustrine and floodplain), ranging from 11.6 to 0.95 Ma are consistent with the existing magnetostratigraphic and biostratigraphic data standing mainly on the evolution degree of endemic mollusk fauna, mammals and dinocysts. This agreement confirms our assumption that the incoming beryllium fluxes remained constant over the studied time period and thus that the two initial 10Be/9Be ratios determined in actual Holocene/Late Pleistocene sediments (lacustrine and floodplain) are valid for these environments. The obtained ages indicate gradual progradation of the deltaic depositional systems across the Danube Basin with a clear time-transgressional character, replacing basin floor and shelfal environments. Deltaic sedimentation occurred firstly in the north at foothills of the Western Carpathians from 11.0 Ma, and changed to the alluvial environment after 10.5 Ma. At the same time (~ 10.5 Ma), the paleo-Danube deltaic system draining the Eastern Alps entered the study area from the Vienna Basin situated on the West. Later, the deltaic systems were merged in the central part of the basin and reached its southeastern margin at ~ 9.4 Ma. Regression of the Lake Pannon from the southernmost part of the study area is evidenced after 8.7 Ma. Alluvial deposition of meandering rivers lasting until 6.0-5.0 Ma followed and was interrupted by the early Pliocene basin inversion. Sedimentation of braided streams took place during the late Pliocene and Pleistocene, reflecting uplift of mountains surrounding the basin margins. This study documents the powerful potential of the authigenic 10Be/9Be dating method and its reliability in a basin with complicated tectonic and sedimentary history. It demonstrates that

  11. Distribution patterns, population status and conservation of Melanosuchus niger and Caiman yacare (Crocodylia, Alligatoridae) in oxbow lakes of the Ichilo river floodplain, Bolivia.

    PubMed

    Aguilera, Ximena; Coronel, Jorge S; Thierry, Oberdorff; Van Damme, Paul A

    2008-06-01

    Caiman yacare (lagarto) and Melanosuchus niger (black caiman), sympatric species in the Bolivian Amazon basin, have been severely overexploited in the past. We present the results of a standardized survey of C. yacare and M. niger populations in order to evaluate their actual population status in twelve oxbow lakes of the Ichilo River floodplain. Additionally we explored the effect of environmental and anthropogenic variables on caiman distribution patterns. The average density of C yacare and M niger in the shoreline of floodplain lakes was of 6 and 1 ind/km, respectively. For both species, the population was composed mainly of juvenile individuals. We used regression tree analysis (RTA) to assess patterns of M. niger and C. yacare densities with eight environmental and two anthropogenic variables. The RTA analysis showed that the variation in the densities of both C. yacare (52.4%) and M. niger (36.8 %) was related to water conductivity. For C yacare, higher densities occurred at higher values of water conductivity, while M. niger densities followed an opposite trend, resulting in relatively well spatially segregated populations of the two species. After excluding conductivity, Lake-River Distance (LRD) was shown to be the main splitting variable in the RTA analysis. The observed distribution patterns may be the result of the historical post-hunting situation, in combination with differences in habitat selection by the two species, and competitive exclusion processes between the two species. M. niger, a species reported to be recovering slowly from previous low population levels, appears relatively well protected in the Ichilo river floodplain. PMID:19256453

  12. Real time flood forecasting in the Upper Danube basin

    NASA Astrophysics Data System (ADS)

    Nester, Thomas; Komma, Jürgen; Blöschl, Günter

    2016-04-01

    In this contribution, we report on experiences with developing the flood forecasting model for the Upper Danube basin and its operational use since 2006. The model system consists of a hydrological model for the catchments and a hydrodynamic model for the Danube and uses meteorological forecasts for the next 48 hours. The parameters of the hydrological model were estimated based on the Dominant Processes Concept. Runoff data are assimilated in real time to update modelled soil moisture. An analysis of the performance of the hydrological model indicates 88% of the snow cover in the basin to be modelled correctly on more than 80% of the days. Runoff forecasting errors decrease with catchment area and increase with forecast lead time. The forecast ensemble spread is shown to be a meaningful indicator of the forecast uncertainty. We also show forecasts from the 2013 flood in the Upper Danube basin. There was a tendency for the precipitation forecasts to underestimate event precipitation and for the runoff model to overestimate runoff generation which resulted in, overall, rather accurate runoff forecasts.

  13. Current status and restoration options for floodplains along the Danube River.

    PubMed

    Hein, Thomas; Schwarz, Ulrich; Habersack, Helmut; Nichersu, Iulian; Preiner, Stefan; Willby, Nigel; Weigelhofer, Gabriele

    2016-02-01

    Floodplains are key ecosystems of riverine landscapes and provide a multitude of ecosystem services. In most of the large river systems worldwide, a tremendous reduction of floodplain area has occurred in the last 100 years and this loss continues due to pressures such as land use change, river regulation, and dam construction. In the Danube River Basin, the extent of floodplains has been reduced by 68% compared to their pre-regulation area, with the highest losses occurring in the Upper Danube and the lowest in the Danube Delta. In this paper, we illustrate the restoration potential of floodplains along the Danube and its major tributaries. Via two case studies in the Upper and Lower Danube, we demonstrate the effects of restoration measures on the river ecosystem, addressing different drivers, pressures, and opportunities in these regions. The potential area for floodplain restoration based on land use and hydromorphological characteristics amounts to 8102 km(2) for the whole Danube River, of which estimated 75% have a high restoration potential. A comparison of floodplain status and options for restoration in the Upper and Lower Danube shows clear differences in drivers and pressures, but certain common options apply in both sections if the local context of stakeholders and societal needs are considered. New approaches to flood protection using natural water retention measures offer increased opportunities for floodplain restoration, but conflicting societal needs and legal frameworks may restrict implementation. Emerging issues such as climate change and invasive non-native species will need careful consideration in future restoration planning to minimize unintended effects and to increase the resilience of floodplains to these and other pressures.

  14. Current status and restoration options for floodplains along the Danube River.

    PubMed

    Hein, Thomas; Schwarz, Ulrich; Habersack, Helmut; Nichersu, Iulian; Preiner, Stefan; Willby, Nigel; Weigelhofer, Gabriele

    2016-02-01

    Floodplains are key ecosystems of riverine landscapes and provide a multitude of ecosystem services. In most of the large river systems worldwide, a tremendous reduction of floodplain area has occurred in the last 100 years and this loss continues due to pressures such as land use change, river regulation, and dam construction. In the Danube River Basin, the extent of floodplains has been reduced by 68% compared to their pre-regulation area, with the highest losses occurring in the Upper Danube and the lowest in the Danube Delta. In this paper, we illustrate the restoration potential of floodplains along the Danube and its major tributaries. Via two case studies in the Upper and Lower Danube, we demonstrate the effects of restoration measures on the river ecosystem, addressing different drivers, pressures, and opportunities in these regions. The potential area for floodplain restoration based on land use and hydromorphological characteristics amounts to 8102 km(2) for the whole Danube River, of which estimated 75% have a high restoration potential. A comparison of floodplain status and options for restoration in the Upper and Lower Danube shows clear differences in drivers and pressures, but certain common options apply in both sections if the local context of stakeholders and societal needs are considered. New approaches to flood protection using natural water retention measures offer increased opportunities for floodplain restoration, but conflicting societal needs and legal frameworks may restrict implementation. Emerging issues such as climate change and invasive non-native species will need careful consideration in future restoration planning to minimize unintended effects and to increase the resilience of floodplains to these and other pressures. PMID:26475242

  15. Contributions to the knowledge of the Danube waters impact on the Black Sea

    NASA Astrophysics Data System (ADS)

    Gomoiu, Marian-Traian; Oaie, Gheorghe; Secrieru, Dan; Vasiliu, Dan; Begun, Tatiana; Caraus, Ioan

    2013-04-01

    Rivers usually have a positive impact on marine areas where they discharge their waters, fertilizing them and supporting high biological productivity, the Danube River being a good example in this respect. Given the conditions of chaotic industrialization and the discharge into rivers of many chemicals, some of high toxicity, the eutrophication influence changed its beneficial nature, turning into a toxic polluting influence, with catastrophic effects on the structure and functioning of coastal ecosystems, which is a situation well-known and in the area of the Danube mouths for the period 1970-1990. After 1990, under major political changes in socio-economic systems, the environmental pressures with impact on marine coastal ecosystems diminished; these pressures had been maintained by hydrological systems opening to the marine areas. What is the current situation of these pressures? What are the major characteristics of the organisms associations under the direct influence of the Danube? In this paper, the authors try to give some answers to these questions. In the framework of the lower Danube monitoring program, conducted by GeoEcoMar during 2009-2012, measurements were made and samples collected in more than 230 stations along the Romanian sector of the Danube River. The main aspects related to the ecological state of the River were: - Physico-chemical and biological (phytoplankton); - Sediment granulometry and inorganic chemistry - CaCO3, Fe2O3, TiO2, Zr, Ba, Rb, Zn, Ni, MnO, Cr, V, Co, Pb; - Ammonia, TOC, total cyanide, organochlorine pesticides in sediments; - Physico-chemical analyses of water samples. According to the results, the areas suspected of pollution from anthropogenic sources and also from other activities, could be outlined as follows: - The stretch between km 1072 (Danube entry to Romania) and km 1039 - downstream the mining sector Moldova Veche; - Sector between km 957-947, near the Iron Gates I dam; - Danube - Black Sea Canal (the NPP

  16. Monitoring and assessment of oil pollution in the Danube River during the transnational Joint Danube Survey.

    PubMed

    Literathy, P

    2006-01-01

    An extensive river basin monitoring exercise of 2581 km of the river Danube was carried out in 2001 under of the aegis of the transnational Joint Danube Survey (JDS). Water, suspended and bottom sediment, and biota samples were collected from 76 cross-sections in the Danube main stream and 22 major tributaries during the 39-day cruise, and analysed for chemical and biological variables. During the JDS, oil pollution was characterised with GC-FID and fluorescence measurements. Fluorescence fingerprints of the cyclohexane extracts of water, suspended and bottom sediment samples allowed characterization and quantification of the type and level of oil pollution. The results revealed that the oil pollution in the water varied in the range 1-300 microg/l. Gasoline type contamination was found at the higher concentration levels and diesel oil type in the lower concentrations. Oil contamination was similar in the suspended and bottom sediment (the less than 63 microm grain-size fraction) and varied between 2-140 mg/kg. A higher contamination level was found along the middle Danube reach. The highest concentrations were observed in the suspended sediment upstream of the Danube delta. Weathered crude oil characteristics were observed in the upper Danube basin, whereas between crude and diesel oil characteristics were dominant along most of the middle and the lower Danube reaches.

  17. Use of LANDSAT data for resources investigation in the lower basin of Danube and Danube Delta

    NASA Technical Reports Server (NTRS)

    Oprescu, N. (Principal Investigator)

    1975-01-01

    The author has identified the following significant results. A most important is that bands 4 and 5 very clearly show the sedimentary discharge into the sea and the spreading regime in the sea at the mouth of the Danube and out at sea at great distances to over 100 km. Another particularly significant result is shown by bands 6 and 7, presenting the successive stages of sediments in the Danube Delta, with the clear marking of the separation between the fluvial and marine delta. The survey of floods and of some of their effects may also be studied on all of the bands in the complex area of the Danube Delta and in the lower basin of the Danube.

  18. Biodiversity of testate amoebae (Arcellinida and Euglyphida) in different habitats of a lake in the Upper Paraná River floodplain.

    PubMed

    Alves, Geziele Mucio; Velho, Luiz Felipe Machado; Simões, Nadson Ressyé; Lansac-Tôha, Fábio Amodêo

    2010-11-01

    This study aimed to investigate the testate amoebae (Arcellinida and Eugliphida) species diversity in plankton, macrophytes and aquatic sediment samples from a shallow lake of the Upper Paraná River floodplain. Samples were carried out from April 2007 to March 2008. We recorded 89 taxa, belonging to 10 families. Eighty-two taxa were found in the aquatic sediment, 71 in the macrophytes and 53 in the plankton. Highest values of alpha diversity were observed in the aquatic sediment. Although the plankton had the highest number of accidental species, accessory and constant species were also observed in this habitat. Most of the species classified as constant for the plankton belonged to the genus Arcella. Most of the constant species in the macrophytes and aquatic sediment belonged to the genus Difflugia. This study supports the idea that the presence of these protists in the plankton should not be attributed only to stochastic processes because (i) the species diversity recorded in this habitat was remarkably high in relation to the total biodiversity of the lake, and (ii) we also recorded frequent and constant species in the plankton.

  19. Modelling the coastal processes at the mouths of the Danube River in the Black Sea

    NASA Astrophysics Data System (ADS)

    Rusu, Eugen; Zanopol, Andrei

    2014-05-01

    The mouths of the Danube River in the Black Sea represent the main southern entrance in the seventh Pan European transportation corridor that links the Black and the Northern seas and is the most important inland navigable waterway in Europe. For this reason the coastal area close to the Danube Delta is subjected to high navigation traffic, which is crucially affected by the strong processes mainly induced by the interactions between the waves and the currents generated by the Danube River outflow. From this perspective, the objective of the present work is to develop a computational framework based on numerical models able to evaluate properly the effects of these interactions and to provide reliable predictions concerning the wave and current conditions corresponding to various environmental patterns. Following this target, a wave modelling system, SWAN based, was implemented in the entire basin of the Black Sea and focused on the coastal sector at the entrance of the Danube Delta. As a next step of the modelling process, SWAN simulations were performed at two different computational levels, considering in parallel the situations without and with the current fields for the main environmental conditions characteristic to the target area. The first level covers the entire coastal area at the mouths of the Danube River and has a resolution in the geographical space of 500m. The second is a computational domain with the resolution of 50m that is focused on the Sulina channel, which is the main navigation gate at the mouths of the Danube River. The results show that the presence of the currents induces relevant enhancements in terms of significant wave heights. Additionally, the Benjamin Feir index (BFI) was also evaluated. This is a spectral shape parameter that is related to the kurtosis of the distribution and indicates the risk of the freak wave occurrence. The enhanced values for BFI in the case when the current fields are considered in the modelling process

  20. Molecular characterization of the endophytic fungal community associated with Eichhornia azurea (Kunth) and Eichhornia crassipes (Mart.) (Pontederiaceae) native to the Upper Paraná River floodplain, Brazil.

    PubMed

    Almeida, T T; Orlandelli, R C; Azevedo, J L; Pamphile, J A

    2015-05-11

    Endophytic fungi live in the interior of healthy plants without causing them any damage. These fungi are of biotechnological interest; they may be used in the biological control of pests and plant diseases, and in the pharmaceutical industry. The aquatic macrophytes Eichhornia azurea (Kunth) and Eichhornia crassipes (Mart.) belong to the Pontederiaceae family. The first is a fixed-floating species and the second is a free-floating species that is known for its phytoremediation potential. The fungal endophytes associated with the leaves of E. azurea and E. crassipes, native to the Upper Paraná River floodplain, Brazil, were isolated. The sequencing of the ITS1-5.8S-ITS2 region of ribosomal DNA was performed and the nucleotide sequences obtained were compared with those available in the GenBank database for the molecular identification of the isolates. The construction of phylogenetic trees was performed using the MEGA5 software. The results showed that high colonization frequencies were obtained from the 610 foliar fragments sampled from each plant: 87.86% for E. azurea and 88.85% for E. crassipes. At the genus level, it was possible to identify 19 fungal endophytes belonging to the genera Alternaria, Bipolaris, Cercospora, Diaporthe, Gibberella, Pestalotiopsis, Plectosphaerella, Phoma, and Saccharicola. Two other endophytes were identified at the species level (Microsphaeropsis arundinis). Genera Bipolaris, Cercospora, Microsphaeropsis, and Phoma were found as endophytes in the two macrophytes and the other genera were host-specific, being isolated from only one macrophyte, proving that there is a small difference in the endophytic diversity of the two Eichhornia species analyzed.

  1. Water balance analysis of the Morava River floodplain in the Kostice-Lanžhot transect using the WBCM-7 model.

    PubMed

    Kovář, Pavel; Heřmanovská, Darina; Hadaš, Pavel; Hrabalíková, Michaela; Pešková, Jitka

    2016-02-01

    The study area of the Morava River floodplain is situated between the rivers Morava and Kyjovka in the reach from Hodonín to Lanžhot. This experimental area was chosen because during the last 30 years, there has been a serious problem with the frequent occurrence of hydrological extremes, such as floods and droughts. Dry seasons have a very negative impact on the floodplain forest and have been caused mainly by regulation of the Morava River channel in the 1970s. Since flooding in the catastrophic year 1977, a part of this area has served as a polder for flood impact mitigation of the urbanised area of the town of Lanžhot. Management and farming practices have been heavily affected by the enormous economic and ecological damage due to long-term flooding of agricultural land. The purpose of this study is to assess the extent to which the precipitation in the growing season of the dry years 2003 and 2011 was deficient, in comparison with the normal year 2009, through a study of the actual evapotranspiration caused by the significant drought in the Morava floodplain. A similar but converse situation in the wet year 2010 was also analysed, with the aim to show the differences in the components of the water balance equation in the growing seasons of all the extreme years tested here. The daily data from the Kostice climatological station were processed using the WBCM-7 model, where the input parameters were calibrated by the fluctuation of the groundwater table in the control borehole.

  2. Water balance analysis of the Morava River floodplain in the Kostice-Lanžhot transect using the WBCM-7 model.

    PubMed

    Kovář, Pavel; Heřmanovská, Darina; Hadaš, Pavel; Hrabalíková, Michaela; Pešková, Jitka

    2016-02-01

    The study area of the Morava River floodplain is situated between the rivers Morava and Kyjovka in the reach from Hodonín to Lanžhot. This experimental area was chosen because during the last 30 years, there has been a serious problem with the frequent occurrence of hydrological extremes, such as floods and droughts. Dry seasons have a very negative impact on the floodplain forest and have been caused mainly by regulation of the Morava River channel in the 1970s. Since flooding in the catastrophic year 1977, a part of this area has served as a polder for flood impact mitigation of the urbanised area of the town of Lanžhot. Management and farming practices have been heavily affected by the enormous economic and ecological damage due to long-term flooding of agricultural land. The purpose of this study is to assess the extent to which the precipitation in the growing season of the dry years 2003 and 2011 was deficient, in comparison with the normal year 2009, through a study of the actual evapotranspiration caused by the significant drought in the Morava floodplain. A similar but converse situation in the wet year 2010 was also analysed, with the aim to show the differences in the components of the water balance equation in the growing seasons of all the extreme years tested here. The daily data from the Kostice climatological station were processed using the WBCM-7 model, where the input parameters were calibrated by the fluctuation of the groundwater table in the control borehole. PMID:26733468

  3. Interannual variability of phytoplankton in the main rivers of the Upper Paraná River floodplain, Brazil: influence of upstream reservoirs.

    PubMed

    Rodrigues, L C; Train, S; Bovo-Scomparin, V M; Jati, S; Borsalli, C C J; Marengoni, E

    2009-06-01

    The interannual variation of phytoplankton communities in the three main rivers of the Upper Paraná River floodplain is evaluated in relation to changes in the hydrosedimentological regime. These changes are a result of climatic variability and the formation of Porto Primavera Reservoir, located at the upper Paraná River. Phytoplankton species richness and density were investigated in rivers during a prior period (1993-1994) and eight years after reservoir impoundment (2000-2007). Multiple analyses were conducted to test the differences between these time periods in order to find predictor variables for phytoplankton attributes. A total of 454 phytoplanktonic taxa were found. The regression analysis revealed significant differences between periods. In the years following construction of the Porto Primavera dam, species richness was lower in the Paraná River and density was higher in the three rivers. In general, the algal density decreased from 2005 to 2007. Diatoms and cyanobacteria contributed significantly to the total density during the period from March 1993 to February 1994. The years 2000-2007 presented the lowest diatom contribution to species richness and the highest cyanobacteria contribution. From 2000 on, cryptomonads and cyanobacteria dominated. The interannual variability of phytoplankton was probably influenced by changes in hydrosedimentological regime due to climatic variations (La Niña and El Niño-Southern Oscillation events--ENSO) and the operational procedures associated with an upstream reservoirs. Studies on climatic variability and its effects on hydrosedimentological regimes of the Paraná, Baía and Ivinhema rivers and the biota therein are necessary to obtain subsidies for management, including decisions related to the operation of dams upstream and downstream of the study area, with the purpose of minimizing risks to the Environmental Protection Area.

  4. Ecological risk assessment of great horned owls (Bubo virginianus) exposed to PCDD/DF in the Tittabawassee River floodplain in Midland, Michigan, USA.

    PubMed

    Coefield, Sarah J; Fredricks, Timothy B; Seston, Rita M; Nadeau, Michael W; Tazelaar, Dustin L; Kay, Denise P; Newsted, John; Giesy, John P; Zwiernik, Matthew J

    2010-10-01

    Soils and sediments downstream of Midland, Michigan, USA have elevated polychlorinated dibenzofuran (PCDF) and polychlorinated dibenzo-p-dioxin (PCDD) concentrations. To determine if the PCDD/DF concentrations have the potential to adversely affect terrestrial avian predators, a site-specific, multiple lines of evidence risk assessment was conducted for the great horned owl (Bubo virginianus; GHO). As long-lived resident top predators, the GHO has the potential to be exposed to relatively great concentrations of bioaccumulative compounds such as PCDD/DF. From 2005 to 2008, concentrations of PCDD/DF were measured in blood plasma of adult and nestling GHOs and addled eggs. Indicators of the condition of the population, including abundance and reproductive success, were collected along 115 km of river corridor. Fifty-five active 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) equivalents (TEQ(WHO-Avian)) nests were monitored in 21 breeding territories from 2005 to 2008. The geometric mean concentration in blood plasma of GHOs was greater in the study area (SA) than in the reference area (RA) for both adults (RA: 3.1; SA: 9.4 ng TEQ(WHO-Avian)/kg) and nestlings (RA: 0.82 ng TEQ(WHO-Avian)/kg, SA: 2.1 ng TEQ(WHO-Avian)/kg) GHOs, but less than concentrations expected to cause adverse effects based on laboratory studies. Concentrations of TEQ(WHO-Avian) in addled GHO eggs were also greater in the SA than the RA (50 and 7.3 ng/kg, wet weight, respectively), but were less than concentrations expected to cause adverse effects. The GHO population condition and productivity were both greater in the study area than in the reference area and were similar to other GHO populations. This result suggests the GHO population in the Tittabawassee River floodplain is consistent with what would be expected for this area. PMID:20872699

  5. Communications: quantum teleportation across the Danube.

    PubMed

    Ursin, Rupert; Jennewein, Thomas; Aspelmeyer, Markus; Kaltenbaek, Rainer; Lindenthal, Michael; Walther, Philip; Zeilinger, Anton

    2004-08-19

    Efficient long-distance quantum teleportation is crucial for quantum communication and quantum networking schemes. Here we describe the high-fidelity teleportation of photons over a distance of 600 metres across the River Danube in Vienna, with the optimal efficiency that can be achieved using linear optics. Our result is a step towards the implementation of a quantum repeater, which will enable pure entanglement to be shared between distant parties in a public environment and eventually on a worldwide scale.

  6. Effects of the flood regime on the body condition of fish of different trophic guilds in the Upper Paraná River floodplain, Brazil.

    PubMed

    Abujanra, F; Agostinho, A A; Hahn, N S

    2009-06-01

    In this study, we evaluated the influence of various hydrological cycles on the feeding body condition of fish species of different trophic guilds in the Paraná River floodplain, as well as the impacts of upstream impoundments on fish conditions. Attributes of the river floods (duration, time of year, intensity, and variability in a given year) and the body condition, measured by the mean residuals of length-weight ratios, of the detritivorous, herbivorous, insectivorous, invertivores, omnivorous, piscivorous, and planktivorous species were evaluated. Fish were sampled during a period before (1986-1994) and after (2000-2004) the completion of filling of the Porto Primavera Reservoir, which is located upstream from the floodplain area under study. Three sub-basins in the floodplain were sampled: the Ivinheima River, which has no dams; the Paraná River, which has several dams; and the Baia River, which is influenced by the Paraná. A two-way ANOVA identified significant variations in mean body conditions for localities and for the hydrological cycles, and the interactions were also significant. The findings revealed that before the Porto Primavera Reservoir was filled, the body condition of the feeding guilds varied similarly in the three sub basins, but this pattern was not observed after filling was completed. However, in years with minor or no floods, the body condition was high, especially in the sub-basins influenced by Porto Primavera (Paraná and Baía). Pearson's and Spearman's correlations showed that most effects of the floods were unfavorable to the body condition of the guilds, except for the annual variation in water level, which aids herbivores in accessing allochthonous food resources. Detritivores were negatively affected by all flood attributes. A correlation between the relative stomach weight (mean residual of the ratio of total and stomach weights) and the body condition demonstrated the poor relationship between the amount of food intake and

  7. Effects of the flood regime on the body condition of fish of different trophic guilds in the Upper Paraná River floodplain, Brazil.

    PubMed

    Abujanra, F; Agostinho, A A; Hahn, N S

    2009-06-01

    In this study, we evaluated the influence of various hydrological cycles on the feeding body condition of fish species of different trophic guilds in the Paraná River floodplain, as well as the impacts of upstream impoundments on fish conditions. Attributes of the river floods (duration, time of year, intensity, and variability in a given year) and the body condition, measured by the mean residuals of length-weight ratios, of the detritivorous, herbivorous, insectivorous, invertivores, omnivorous, piscivorous, and planktivorous species were evaluated. Fish were sampled during a period before (1986-1994) and after (2000-2004) the completion of filling of the Porto Primavera Reservoir, which is located upstream from the floodplain area under study. Three sub-basins in the floodplain were sampled: the Ivinheima River, which has no dams; the Paraná River, which has several dams; and the Baia River, which is influenced by the Paraná. A two-way ANOVA identified significant variations in mean body conditions for localities and for the hydrological cycles, and the interactions were also significant. The findings revealed that before the Porto Primavera Reservoir was filled, the body condition of the feeding guilds varied similarly in the three sub basins, but this pattern was not observed after filling was completed. However, in years with minor or no floods, the body condition was high, especially in the sub-basins influenced by Porto Primavera (Paraná and Baía). Pearson's and Spearman's correlations showed that most effects of the floods were unfavorable to the body condition of the guilds, except for the annual variation in water level, which aids herbivores in accessing allochthonous food resources. Detritivores were negatively affected by all flood attributes. A correlation between the relative stomach weight (mean residual of the ratio of total and stomach weights) and the body condition demonstrated the poor relationship between the amount of food intake and

  8. A conceptual model for groundwater - surface water interactions in the Darling River Floodplain, N.S.W., Australia

    NASA Astrophysics Data System (ADS)

    Brodie, R. S.; Lawrie, K.; Somerville, P.; Hostetler, S.; Magee, J.; Tan, K. P.; Clarke, J.

    2013-12-01

    Multiple lines of evidence were used to develop a conceptual model for interaction between the Darling River and associated floodplain aquifers in western New South Wales, Australia. Hydrostratigraphy and groundwater salinities were mapped using airborne electromagnetics (AEM), validated by sonic-core drilling. The AEM was highly effective in mapping groundwater freshening due to river leakage in discrete zones along the river corridor. These fresh resources occurred in both the unconfined Quaternary aquifers and the underlying, largely semi-confined Pliocene aquifers. The AEM was also fundamental to mapping the Blanchetown Clay aquitard which separates these two aquifer systems. Major-ion chemistry highlighted a mixing signature between river waters and groundwaters in both the Quaternary and Pliocene aquifers. Stable isotope data indicates that recharge to the key Pliocene aquifers is episodic and linked to high-flow flood events rather than river leakage being continuous. This was also evident when groundwater chemistry was compared with river chemistry under different flow conditions. Mapping of borehole levels showed groundwater mounding near the river, emphasising the regional significance of losing river conditions for both aquifer systems. Critically, rapid and significant groundwater level responses were measured during large flood events. In the Pliocene aquifers, continuation of rising trends after the flood peak receded confirms that this is an actual recharge response rather than hydraulic loading. The flow dependency of river leakage can be explained by the presence of mud veneers and mineral precipitates along the Darling River channel bank when river flows are low. During low flow conditions these act as impediments to river leakage. During floods, high flow velocities scour these deposits, revealing lateral-accretion surfaces in the shallow scroll plain sediments. This scouring allows lateral bank recharge to the shallow aquifer. During flood

  9. Linking river, floodplain, and vadose zone hydrology to improve restoration of a coastal river affected by saltwater intrusion.

    PubMed

    Kaplan, D; Muñoz-Carpena, R; Wan, Y; Hedgepeth, M; Zheng, F; Roberts, R; Rossmanith, R

    2010-01-01

    Floodplain forests provide unique ecological structure and function, which are often degraded or lost when watershed hydrology is modified. Restoration of damaged ecosystems requires an understanding of surface water, groundwater, and vadose (unsaturated) zone hydrology in the floodplain. Soil moisture and porewater salinity are of particular importance for seed germination and seedling survival in systems affected by saltwater intrusion but are difficult to monitor and often overlooked. This study contributes to the understanding of floodplain hydrology in one of the last bald cypress [Taxodium distichum (L.) Rich.] floodplain swamps in southeast Florida. We investigated soil moisture and porewater salinity dynamics in the floodplain of the Loxahatchee River, where reduced freshwater flow has led to saltwater intrusion and a transition to salt-tolerant, mangrove-dominated communities. Twenty-four dielectric probes measuring soil moisture and porewater salinity every 30 min were installed along two transects-one in an upstream, freshwater location and one in a downstream tidal area. Complemented by surface water, groundwater, and meteorological data, these unique 4-yr datasets quantified the spatial variability and temporal dynamics of vadose zone hydrology. Results showed that soil moisture can be closely predicted based on river stage and topographic elevation (overall Nash-Sutcliffe coefficient of efficiency = 0.83). Porewater salinity rarely exceeded tolerance thresholds (0.3125 S m(-1)) for bald cypress upstream but did so in some downstream areas. This provided an explanation for observed vegetation changes that both surface water and groundwater salinity failed to explain. The results offer a methodological and analytical framework for floodplain monitoring in locations where restoration success depends on vadose zone hydrology and provide relationships for evaluating proposed restoration and management scenarios for the Loxahatchee River.

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

    PubMed

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

    2016-02-01

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

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

    PubMed

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

    2016-02-01

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

  12. The Impact of the Danube River Mouths Geomorphological Processes on the Ecosystem, Coastal Development and Regional Navigation

    NASA Astrophysics Data System (ADS)

    Mateescu, Razvan; Malciu, Viorel; Spinu, Alina

    2013-04-01

    The anthropogenic influences on the Danube Delta Coast, with major effect on the evolution of its littoral processes are represented by the perturbation of the longshore sediment transport, due to coastal constructions, and as well due to the decrease of solid discharge, as a consequence of the hydro-technical works/dams extension in the reception basin, as well in the main course of the rivers. Certain vulnerable areas of the Danube Delta Coast are strongly influenced by inland works/development as well as Danube flow regime, at regional and local scale. In the Sulina arm area, the extension of the channel jetties had a double effect, representing the cut-off of the south coast current, carrier of a portion of the solid load on the Chilia arm, and removal of its own load out of the coastal circulation in the offshore currents. The sand dunes dynamics including the sediment changes between submerged shore and dunes system are major issues within the channel entrance. The work presents the results on the impacts of the coastal geomorphological processes of the Danube Delta on navigation and ecological areas. Thus, the variability of the sea-land interface, for a period of several decades, has been revisited on the basis of the historical maps, coastal survey of emerged beach profiles, sand dunes and recent GPS measurement, developed on the Romanian Danube Delta littoral, together with certain impact assessments in the delta areas, including the ecosystem response to shoreline variability, sediment transport on short and medium term, in the context in which the major factor is the Danube discharge, as well the sea-level rise.

  13. Danube and Sava river sediment monitoring in Belgrade and its surroundings.

    PubMed

    Crnković, Dragan M; Crnković, Natasa S; Filipović, Anka J; Rajaković, Ljubinka V; Perić-Grujić, Aleksandra A; Ristić, Mirjana D

    2008-10-01

    Belgrade is the largest city in Serbia located at the confluence of river Sava to the Danube river. The quality of water and sediments of rivers which run through Belgrade is of a significant importance, since water from these rivers is a source of Belgrade drinking water supply system and probable anthropogenic contamination is related to industrialization and inputs of sewage water. In order to follow the sediment quality of river Sava (km 62-1) and river Danube (km 1193-1124) in Belgrade and its surroundings, the content of As, Cd, Cr, Cu, Zn, Ni, Pb and Hg were measured in the period 2001--2005. The content of 16 polycyclic aromatic hydrocarbons (PAHs) was measured in 2005. The results have shown that, due to the metal content, examined Danube sediment quality varies from class 1 to class 3, predominantly nickel being the class determining parameter. Elevated copper, zinc and mercury concentrations were measured at some profiles, as well. Typically due to the nickel content, Sava sediment quality belongs to class 3 in the period 2001--2004. Elevated concentrations of cadmium, zinc and mercury were observed in 2001, as well. Moreover, in 2005, sediments from three profiles were extremely polluted with nickel, leading the Sava sediment to class 4, when highest urgency measures are needed. Total PAH concentration in the sediments from Danube (213.1-575.4 microg kg(- 1)) was lower than total PAH concentration from Sava sediments (416.2-595.3 microg kg(- 1)). Nevertheless, according to the Dutch regulatory system, it has been concluded that river sediments in Belgrade and its surroundings were not polluted with PAHs in 2005. PMID:18780212

  14. C3 or C4 macrophytes: a specific carbon source for the development of semi-aquatic and terrestrial arthropods in central Amazonian river-floodplains according to delta13C values.

    PubMed

    Adis, J; Victoria, R L

    2001-01-01

    C4 plant species were proposed to generally represent inferior food sources compared to C3 plants thus are avoided by herbivores, particularly insects. This was tested in semi-aquatic and terrestrial arthropods from Amazonian river-floodplains by carbon isotope discrimination (delta13C). Two semi-aquatic grasshopper species (Stenacris f. fissicauda, Tucavaca gracilis-Acrididae) obtain their carbon during development from specific C4 macrophytes and two semi-aquatic species (Cornops aquaticum-Acrididae, Paulinia acuminata-Pauliniidae) from specific C3 macrophytes. The terrestrial millipede Mestosoma hylaeicum (Paradoxosomatidae) obtains about 45% of its carbon from roots of one C4 macrophyte during the development of immatures whereas adults use other food sources, including C3 trees. Results suggest, that (1) both C4 and C3 plants represent distinct hosts for terrestrial arthropods in Amazonia; (2) immatures may use plant species with a different photosynthetic pathway than adults.

  15. The July 1897 and September 1899 floods in the Upper Danube Basin, and comparisons with the June 2013 flood

    NASA Astrophysics Data System (ADS)

    Nester, Thomas; Komma, Jürgen

    2016-04-01

    During the 19th century, rivers and lakes were used increasingly for vessel traffic, commercial and industrial purposes. Also, the need for water in settlements increased steadily. In 1893, the Austrian Hydrographic Central Bureau was founded to evaluate existing hydrographic data and to set up new data collecting stations. In 1897 and 1899, only 4 and 6 years after the foundation of the Hydrographic Central Bureau, two major floods occurred in the Upper Danube basin which accelerated the establishment of a flood information system for the Danube. In this contribution, we give an overview of the July 1897 and September 1899 floods, which are among the 6 largest floods in the last two centuries in the Upper Danube basin. Maximum peak discharge in Vienna was around 9400 m³/s in 1897 and 10500 m³/s in 1899, and only three years ago, this value was exceeded by the June 2013 flood which had a flood peak of 11.000 m³/s. We evaluate the regional evolution of the floods and compare spatial and temporal patterns of precipitation and flood wave propagation along the Danube and its major tributaries.

  16. Parameter estimation using carbon-14 ages: Lessons from the Danube-Tisza interfluvial region of Hungary

    USGS Publications Warehouse

    Sanford, W.E.; Deak, J.; Revesz, K.

    2002-01-01

    Parameter estimation was conducted on a groundwater model of the Danube-Tisza interfluvial region of Hungary. The model was calibrated using 300 water levels and 48 14C ages. The model provided a test of regression methods for a system with a large number of observations. Up to 103 parameters representing horizontal and vertical hydraulic conductivities and boundary conductances were assigned using point values and bilinear interpolation between points. The lowest errors were obtained using an iterative approach with groups of parameters, rather than estimating all of the parameters simultaneously. The model with 48 parameters yielded the lowest standard error of regression.

  17. Long-term tritium monitoring to study river basin dynamics: case of the Danube River basin

    NASA Astrophysics Data System (ADS)

    Aggarwal, Pradeep; Araguas, Luis; Groening, Manfred; Newman, Brent; Kurttas, Turker; Papesch, Wolfgang; Rank, Dieter; Suckow, Axel; Vitvar, Tomas

    2010-05-01

    During the last five decades, isotope concentrations (O-18, D, tritium) have been extensively measured in precipitation, surface- and ground-waters to derive information on residence times of water in aquifers and rivers, recharge processes, and groundwater dynamics. The unique properties of the isotopes of the water molecule as tracers are especially useful for understanding the retention of water in river basins, which is a key parameter for assessing water resources availability, addressing quality issues, investigating interconnections between surface- and ground-waters, and for predicting possible hydrological shifts related to human activities and climate change. Detailed information of the spatial and temporal changes of isotope contents in precipitation at a global scale was one of the initial aims of the Global Network of Isotopes in Precipitation (GNIP), which has provided a detailed chronicle of tritium and stable isotope contents in precipitation since the 1960s. Accurate information of tritium contents resulting of the thermonuclear atmospheric tests in the 1950s and 1960s is available in GNIP for stations distributed world-wide. Use of this dataset for hydrological dating or as an indicator of recent recharge has been extensive in shallow groundwaters. However, its use has been more limited in surface waters, due to the absence of specific monitoring programmes of tritium and stable isotopes in rivers, lakes and other surface water bodies. The IAEA has recently been compiling new and archival isotope data measured in groundwaters, rivers, lakes and other water bodies as part of its web based Water Isotope System for Data Analysis, Visualization and Electronic Retrieval (WISER). Recent additions to the Global Network of Isotopes in Rivers (GNIR) contained within WISER now make detailed studies in rivers possible. For this study, we are re-examining residence time estimates for the Danube in central Europe. Tritium data are available in GNIR from 15

  18. Network-based Modeling of Mesoscale Catchments - The Hydrology Perspective of Glowa-danube

    NASA Astrophysics Data System (ADS)

    Ludwig, R.; Escher-Vetter, H.; Hennicker, R.; Mauser, W.; Niemeyer, S.; Reichstein, M.; Tenhunen, J.

    Within the GLOWA initiative of the German Ministry for Research and Educa- tion (BMBF), the project GLOWA-Danube is funded to establish a transdisciplinary network-based decision support tool for water related issues in the Upper Danube wa- tershed. It aims to develop and validate integration techniques, integrated models and integrated monitoring procedures and to implement them in the network-based De- cision Support System DANUBIA. An accurate description of processes involved in energy, water and matter fluxes and turnovers requires an intense collaboration and exchange of water related expertise of different scientific disciplines. DANUBIA is conceived as a distributed expert network and is developed on the basis of re-useable, refineable, and documented sub-models. In order to synthesize a common understand- ing between the project partners, a standardized notation of parameters and functions and a platform-independent structure of computational methods and interfaces has been established using the Unified Modeling Language UML. DANUBIA is object- oriented, spatially distributed and raster-based at its core. It applies the concept of "proxels" (Process Pixel) as its basic object, which has different dimensions depend- ing on the viewing scale and connects to its environment through fluxes. The presented study excerpts the hydrological view point of GLOWA-Danube, its approach of model coupling and network based communication (using the Remote Method Invocation RMI), the object-oriented technology to simulate physical processes and interactions at the land surface and the methodology to treat the issue of spatial and temporal scal- ing in large, heterogeneous catchments. The mechanisms applied to communicate data and model parameters across the typical discipline borders will be demonstrated from the perspective of a land-surface object, which comprises the capabilities of interde- pendent expert models for snowmelt, soil water movement, runoff formation, plant

  19. Meteorological conditions of the Danube flood in year 1895

    NASA Astrophysics Data System (ADS)

    Melo, Marian; Gera, Martin

    2015-04-01

    The flood in year 1895 belongs to the highest floods on the Danube River and its tributaries. The aim of this contribution is to clarify meteorological causes of this flood. Analysis is based on air temperature and precipitation measurements of some meteorological stations from the Central and southeastern Europe and data from NOAA 20th Century Reanalysis of daily composites. Moreover we bring knowledge gained by studies of materials regarding the historical flood on the Danube River and its tributaries in 1895 as reflected in local contemporary press (Preßburger Zeitung and Wiener Zeitung) in the period from late February till the end of April 1895. This work was supported by the Slovak Research and Development Agency under Contract No. APVV-0303-11 and No. APVV-0015-10.

  20. Analysis of large Danube flood events at Vienna since 1700

    NASA Astrophysics Data System (ADS)

    Kiss, Andrea; Blöschl, Günter; Hohensinner, Severin; Perdigao, Rui

    2014-05-01

    Whereas Danube water level measurements are available in Vienna from 1820 onwards, documentary evidence plays a significant role in the long-term understanding of Danube hydrological processes. Based on contemporary documentary evidence and early instrumental measurements, in the present paper we aim to provide an overview and a hydrological analysis of major Danube flood events, and the changes occurred in flood behaviour in Vienna in the last 300 years. Historical flood events are discussed and analysed according to types, seasonality, frequency and magnitude. Concerning historical flood events we apply a classification of five-scaled indices that considers height, magnitude, length and impacts. The rich data coverage in Vienna, both in terms of documentary evidence and early instrumental measurements, provide us with the possibility to create a relatively long overlap between documentary evidence and instrumental measurements. This makes possible to evaluate and, to some extent, improve the index reconstruction. While detecting causes of changes in flood regime, we aim to provide an overview on the atmospheric background through some characteristic examples, selected great flood events (e.g. 1787). Moreover, we also seek for the answer for such questions as in what way early (pre-instrumental period) human impact such as water regulations and urban development changed flood behaviour in the town, and how much it might have an impact on flood classification.

  1. Use of LANDSAT data for natural resources investigation in the lower basin of Danube and Danube Delta

    NASA Technical Reports Server (NTRS)

    Oprescu, N. (Principal Investigator)

    1977-01-01

    The author has identified the following significant results. Monitoring of excess humidity was possible at the Baragan test site. Qualitative improvements of 20-50% were obtained in regards to soil inventory in the eastern Danube Delta, comparing data with conventional maps. The pedological situation was observed after drainage in impounded enclosures. The appearance of stagnate water was surveyed due to difference in color shades on LANDSAT imagery. Areas with gluey soils, such as lake bottoms rich in CaCO3 and shell grist, were clearly represented. Sediment discharges into the sea at the Danube mouth and plumes over 100 km at sea could be easily distinguished on LANDSAT MSS 4 and 5.

  2. The 87Sr/86Sr aquatic isoscape of the Danube catchment from the source to the mouth as tool for studying fish migrations

    NASA Astrophysics Data System (ADS)

    Zitek, Andreas; Tchaikovsky, Anastassiya; Irrgeher, Johanna; Waidbacher, Herwig; Prohaska, Thomas

    2014-05-01

    Isoscapes - spatially distributed isotope patterns across landscapes - are increasingly used as important basis for ecological studies. The natural variation of the isotopic abundances in a studied area bears the potential to be used as natural tracer for studying e.g. migrations of animals or prey-predator relations. The 87Sr/86Sr ratio is one important tracer, since it is known to provide a direct relation of biological samples to geologically distinct regions, as Sr isotopes are incorporated into living tissues as a proxy for calcium and taken up from the environment without any significant fractionation. Although until now the focus has been mainly set on terrestrial systems, maps for aquatic systems are increasingly being established. Here we present the first 87Sr/86Sr aquatic isoscape of the Danube catchment, the second largest river catchment in Europe, from near its source starting at river km 2581 in Germany down to its mouth to river km 107 in Romania. The total length of the river Danube is 2780 km draining a catchment area 801 463 km2 (10 % of the European continent). The major purpose of this study was to assess the potential of the 87Sr/86Sr isotope ratio to be used as tool for studying fish migrations at different scales in the entire Danube catchment. Within the Joint Danube Research 3 (JDS 3), the biggest scientific multi-disciplinary river expedition of the World in 2013 aiming at the assessment of the ecological status and degree of human alterations along the river Danube, water samples were taken at 68 pre-defined sites along the course of the river Danube including the major tributaries as a basis to create the so called 'Isoscape of the Danube catchment'. The determination of 87Sr/86Sr isotope ratio in river water was performed by multicollector-sector field-inductively coupled plasma-mass spectrometry (MC-SF-ICP-MS). The JDS 3 data were combined with existing data from prior studies conducted within the Austrian part of the Danube catchment

  3. Isochron burial dating of Danube terraces in the course of an interlaboratory comparison on sample preparation in Vienna and Budapest

    NASA Astrophysics Data System (ADS)

    Neuhuber, Stephanie; Ruszkiczay-Rüdiger, Zsófia; Decker, Kurt; Braucher, Regis; Fiebig, Markus; Braun, Mihály; Häuselmann, Philipp; Aster Team

    2016-04-01

    The Neogene development of the Vienna Basin's tectonic history is well-documented in seismic sections and hydrocarbon wells. The late Neogene to Quaternary history is less well preserved due to a gap in the sediment record starting from the Late Pannonian due to a large-scale uplift during a phase of basin inversion [1]. Quaternary sediments in the Vienna Basin form prominent Pleistocene terraces north and south of the Danube's recent floodplain. The Danube's course currently shifts to the south where it erodes into its own gravel terraces that were presumably accumulated during the Pliocene and Early to Middle Pleistocene. North of the Danube, a wide alluvial plain has developed with one prominent Middle Quaternary terrace level 17-25 m above the river (Gänserndorf and Schlosshof Terraces). The most recent tectonic events related to the sinistral movement of the Vienna Basin transform fault system are recorded north of the Danube by faulted terrace segments that were identified by paleoseismological trenching in combination with OSL [2]. In contrast, terraces south of the Danube form a staircase with altitudes ranging between 25 and 130 m above todays water level. The terraces in the south have also been strongly dissected by faults [3], each fault block preserved a slightly different succession of terraces. The fault-related vertical displacements south of the Danube have not yet been quantified. To better understand the Quaternary terrace sequence and its displacement in the southern zone, we use the cosmogenic nuclide pair of 26Al and 10Be for isochron burial dating of a Danube terrace at Haslau an der Donau (~40 m above river level). This terrace is locally the lowest of a staircase of a total of 6 different levels. Based on published geomorphological works, the expected age is Middle Pleistocene. The isochron burial dating method is therefore well-suited to date this sedimentary setting due to the presence of large individual clasts that share the same post

  4. Ecological estimation of the possible variants new Ukrainian shipping way between the Danube and the Black Sea

    NASA Astrophysics Data System (ADS)

    Berlinsky, N.

    2007-05-01

    The better way or optimal variant means economic advisability of organization and using the way and the same time minimization of anthropogenic press. The first problem's factor is - all kinds' variants cross the area of the Danube Biosphere Reserve. The next factor is - all kinds of variants need dredging works in the sea shallow water so called bar's zone for marine entrance channel. As for natural factors there are also two. The first one is a long term delta evolution and the second is the process of water discharge redistribution. If the human influence to the first factor is still limited the second factor's influence can be unlimited - it is easy to do by jetty or dams construction. At present there are nine possible variants of the DWW: Variant 1. It is an artificial canal built as an ameliorative at 80-s between the Danube and Sasik liman. It provokes the water discharge redistribution up on 16.6% from the Danube run off (from the total Q=3000 m3/c for 54 km), hydrological regime in Ukrainian delta and ecological conditions will be sharply worsened. This project supposed a giant dredging works. Variant 2. The Project of engineer P.S. Chekhovich (1904). The length of the canal is 10 km. (The problems are: it is an artificial canal, needs the bridge, cross the wetlands area, redistribute water discharge from the Danube). Variant 3. Solomonov branch - Zhebryany bay modern Project by engineer V.P. Zizak (2000), The problems are: it is an artificial canal also, but with locks, needs the bridge, to cross the wetlands area, the water discharge redistribution from the Danube up on 2.27% (from the total Q=3000 m3/c for 54 km). The length of the canal is 9 km. Two last variants have orientation from Solomonov arm to Zhebriany bay. The other variants of DWW linked with Ochakovsky and Starostambulsky arms systems. Ochakosky system is dying off system from geological point of view. There are two arms which can be examined for DWW - Prorva arm and Potapovo arm. Besides

  5. The Great Diversion: Danube Delta under Human Control (Invited)

    NASA Astrophysics Data System (ADS)

    Giosan, L.

    2009-12-01

    Many deltas around the world are suffering from sediment deficits that render them unstable to current and predicted rates of sea level rise. One solution proposed to alleviate the complete or partial drowning of such deltas is the use of river diversions to increase the quantity of sediment supplied to the delta plain to support marsh accretion. We examine the results of a half century old program of diversion in the Danube delta that led to the creation of an extensive diversion channel network akin in scope and size to a natural deltaic network. Danube’s importance as a shipping route increased after the Crimean War in the 1850s; the European Danube Commission was charged with maintaining the Sulina distributary as a shipping channel until 1940s. In the same period, several canals were dug to aid fishing in lakes and bring freshwater to brackish lagoons. After World War II, Communist authorities dramatically increased the number of canals for fishing, fish-farming and reed harvesting. New data on sedimentation rates and estimates of sediment fluxes suggest that the intensive canalization in the second half of the 20th Century led to increased sediment deposition that compensated the decreasing sediment discharge linked to damming within the internal fluvial part of the delta; however, the external marine delta has become increasingly sediment starved during the same interval. We emphasize the similarities and contrasts between the “human-controlled” and natural deltaic channel networks of the Danube delta and discuss the sustainability of the delta as a sediment budget problem within a sea level rise context.

  6. The River Danube: An Examination of Navigation on the River

    NASA Astrophysics Data System (ADS)

    Cooper, R. W.

    One of the definitions of Navigation that gets little attention in this Institute is (Oxford English Dictionary), and which our French friends call La Navigation. I have always found this subject fascinating, and have previously navigated the Rivers Mekong, Irrawaddy, Hooghly, Indus, Shatt-al-Arab, Savannah and RhMainKanal (RMDK) and the River Danube, a distance of approximately 4000 km. This voyage has only recently become possible with the opening of the connecting RMDK at the end of 1992, but has been made little use of because of the civil war in the former Yugoslavia.

  7. Integrating river basin management and the coastal zone: the (blue) Danube and the (black) sea.

    PubMed

    Maksimović, C; Makropoulos, C K

    2002-01-01

    In order to effectively manage the wide variety of physical, chemical biological and ecological processes in a sensitive coastal environment such as the Black Sea, current environmental management objectives are no longer sufficient: a new management approach has to address the intimate functional linkage between the river basin and the costal environment. Current water quality legislation requires compliance to emission levels based on the chemical analysis of water samples taken at discharge points, such as treatment plants discharging into rivers. While such measures provide a relative indication of the water quality at the point of discharge, they fail to describe accurately and sufficiently the quality of the water received from the watershed or basin. As water flows through the catchment, rainfall run-off from urban and agricultural areas carries sediments, pesticides, and other chemicals into river systems, which lead to coastal waters. The impact of the Kosovo crisis on the Danube ecosystems provides a poignant example of the effects of such diffused pollution mechanisms and reveals a number of interesting pollution mechanisms. This paper discusses both the effects of diffused pollution on the Black Sea, drawing from state-of-the-art reports on the Danube, and proposes a framework for a decision support system based on distributed hydrological and pollution transport simulation models and GIS. The use of ecological health indicators and fuzzy inference supporting decisions on regional planning within this framework is also advocated. It is also argued that even the recently produced GEF document on Black Sea protection scenarios should benefit significantly if the concept of pollution reduction from both urban, industrial and rural areas should undergo a systematic conceptual update in the view of the recent recommendations of the UNEP IETC (2000) document.

  8. Fluvial inheritances of the Cher River floodplain (region Centre, France) as elements of characterization of hydrological dynamics and their past evolutions

    NASA Astrophysics Data System (ADS)

    Vayssière, Anaëlle; Castanet, Cyril; Gautier, Emmanuèle; Virmoux, Clément

    2015-04-01

    -mineral clayey deposits, characteristic of a swampy environment disconnected most of the time from the main river. (3) Finally, the upper part is constituted by a silty layer that may be attributed to an increase in fluvial activity or in erosion dynamics (slope of the catchment, local filling processes …) These first results show a good record of palaeo-environnemental changes in the Cher valley. The comparison with similar works conducted in other catchments of the "Bassin de Paris" shows that these records may describe environmental evolutions during the Pleniglacial, Lateglacial and Holocene. The perspectives of this work is to provide relevant data on the readjustment of the river related with climate changes since the LGM and on the part played by climate changes and ancient societies on the fluvial system during the Holocene.

  9. Groundwater record of halocarbon transport by the Danube River

    USGS Publications Warehouse

    Böhlke, J.K.; Revesz, K.; Busenberg, E.; Deak, J.; Deseo, E.; Stute, M.

    1997-01-01

    Groundwater dating studies have supported the concept that aquifers with low coefficients of dispersion may contain coherent records of past conditions in recharge areas. Groundwater records can provide unique information about natural or anthropogenic changes in the atmosphere and hydrosphere where long-term monitoring data are not available. Here we describe a 40-year record of halocarbon contamination in the Danube River that was retrieved from a shallow aquifer in northwest Hungary. The time scale is based on 3H and He isotope dating of groundwaters that were recharged by the Danube River and moved horizontally away from the river in a surficial gravel aquifer with minor dispersion at a maximum rate of at least 500 m/yr. Analyses of dated groundwaters along a flow path indicate that the river loads of selected compounds (including CFC-12, CFC-113, and trichloroethane) were negligible before about 1950, rose rapidly to peak values in the 1960s and 1970s, and then decreased by varying degrees to the present. Peak concentrations are tentatively attributed to point sources in upstream urban-industrial centers; while recent decreases presumably resulted from declining manufacturing rates and(or) improvements in control of urban- industrial runoff and sewage effluent entering the river in upstream areas.

  10. Contrasted sediment processes and morphological adjustments in three successive cutoff meanders of the Danube delta

    NASA Astrophysics Data System (ADS)

    Tiron Duţu, Laura; Provansal, Mireille; Le Coz, Jérôme; Duţu, Florin

    2014-01-01

    Since the 1980s intensive anthropogenic disturbances have affected the channel of the St. George branch, the southern distributary of the Danube River. The meander cutoff programme since 1984-1988 induced different hydrosedimentary impacts on the local distribution of river flow velocities, discharge, and sediment fluxes between the former meanders and the man-made canals (Ichim and Radoane, 1986; Popa, 1997; Panin, 2003). This paper selects three large cutoff meander reaches of the St. George branch (the Mahmudia, Dunavăţ de Sus, and Dunavăţ de Jos meanders noted here as M1, M2, and M3, respectively) as an example to analyse the human impact in the Danube River delta. The diversion of the flow induces strong modifications by acceleration of the fluxes through the artificial canals combined with dramatically enhanced deposition in the former meander where it was observed in two cases (M1 and M3) with slight modifications in M2. An exceptional flood that occurred in April 2006 offered a good opportunity for scanning different cross sections of the meander systems. Bathymetry, flow velocity, suspended-load concentration, and liquid and solid discharge data were acquired throughout several cross sections of both natural channels and artificial canals of the three cutoffs, using acoustic Doppler current profiler (ADCP) technology, in order to investigate the distribution of the flow and sediment and its impact on the hydrosedimentary processes in each channelized reach and adjacent former meander. Therefore, the results obtained during the 2006 flood were referred to a long-term evolution (1970-2006), analysed by GIS techniques.

  11. The Lower Danube River-Danube Delta-North West Black Sea: A pivotal area of major interest for the past, present and future of its fish fauna--A short review.

    PubMed

    Bănăduc, Doru; Rey, Sonia; Trichkova, Teodora; Lenhardt, Mirjana; Curtean-Bănăduc, Angela

    2016-03-01

    The complex Danube-Black Sea geoecosystem, created by a unique combination of integrated biotopes and biocoenoses related forces and counter-forces in time and space, forms a rich "ichthyosystem". The equilibrium among the fish species captured in the Danube Delta reveals its structural and functional roles in the connectivity of the Danube and Black Sea. The key role of the delta is evidenced by the fact that 57.26% of the Lower Danube-Danube Delta-North West Black Sea fish species use two or three of the subsystems in terms of habitats. Therefore, this convergence area can be considered to be a dynamic and rich "ichthyosystem", with three subsystems. All three evolved interdependently, which permits their flexibility and adaptation in an interdependent way. The habitat heterogeneity, native economic and conservation priority fish species of the Lower Danube-Danube Delta-North Western Black Sea have decreased significantly, and there are no indications that this trend will be halted soon. The Danube "sub-ichtyosystem" seems to be more directly affected than the others. The Lower Danube-Danube Delta-North Western Black Sea "ichthyosystem" exhibits a significant level of flexibility, resilience and adaptation over geological time, but has become much more sensitive to environmental perturbations due to the last century of human impact. This "ichthyosystem" is affected by non-native fish species. The study area represents an interdependent ecological net, without which the specific "ichthyosystem" formed over geological time will disappear. The studied ecological net fish fauna is an accurate indicator of various human pressures. The Lower Danube-Danube Delta-North West Black Sea geoecosystem, in which the Danube Delta provides the pivotal habitat element, is the matrix for a unique "ichthyosystem." However, human impacts decrease its resilience and can induce its extinction.

  12. Investigation of Ice Phenomena On The Hungarian Danube Reach

    NASA Astrophysics Data System (ADS)

    Keve, G.; Kontur, I.

    The importance of scientific work in the field of ice floods is high on the southern Hungarian reach of the Danube. The most dangerous floods of the reach in the past were almost all icy. This used to be so for two main reasons, out of which one is a hydro-meteorological, the other is a morphological factor. River training works on the reach have been completed, only maintenance and small corrections are being done. In spite of the process of global warming, that can be concluded analyzing the past few decades' data, an unfortunate constellation of hydro-meteorological factors can anytime cause serious frosts, and, consequently, ice floods. In our study we statisti- cally analyzed the past hundred years' data series of the reach in question. The results proved the existence of a 30-years long, almost iceless period, that we investigated the reasons for. Because of the above-mentioned rare occurence of ice phenomena, the observation and study of these processes also deteriorated. It is a big luck that Hungarian experts have dealt a lot with past ice phenomena up to 1970. Starting out from literal data and ideas, our investigations and new observations can be massively based. The newest computer technology features are now used for ice observations on the southern Hungarian Danube reach. We could gain useful experience already in the winter of 2001-2002 in computer-aided ice observation (CAIO). In our presenta- tion we would like to give an overall impression about the current issues of CAIO in southern Hungary.

  13. Plants accumulating heavy metals in the Danube River wetlands

    PubMed Central

    2013-01-01

    Background We present herein our results regarding the accumulation of four heavy metals (copper, cadmium, lead, and zinc) in four aquatic species plants (Ceratophyllum demersum, Potamogeton pectinatus, Potamogeton lucens, Potamogeton perfoliatus) collected from the Danube River, South-Western part of Romania and their possible use as indicators of aquatic ecosystems pollution with heavy metals. Methods Elements concentration from the vegetal material was determined through Inductively Coupled Plasma – Mass Spectrometry. Results The species were chosen based on their previous use as bioindicators in aquatic ecosystems and due to the fact they are one of the most frequent aquatic plant species of the Danube River ecosystems within the Iron Gates Natural Park. Highest amounts are recorded for Ceratophyllum demersum (3.52 μg/g for Cd; 22.71 μg/g for Cu; 20.06 μg/g for Pb; 104.23 μg/g for Zn). Among the Potamogeton species, the highest amounts of heavy metals are recorded in Potamogeton perfoliatus (1.88 μg/g for Cd; 13.14 μg/g for Cu; 13.32 μg/g for Pb; 57.96 μg/g for Zn). The sequence for the bioconcentration factors (BCFs) calculated in order to describe the accumulation of the four metals is Cd >> Zn > Pb > Cu. Increase of the zinc concentration determines an increase of the cadmium concentration (Spearman rho=0.40, p=0.02). Conclusions Despite the low ambiental levels of heavy metals, the four aquatic plants have the ability to accumulate significant amounts, which make them useful as biological indicators. BCF value for Ceratophyllum demersum indicated this species as a cadmium hyperaccumulator. PMID:24359799

  14. Wave modelling south of the Danube Delta in the Black Sea

    NASA Astrophysics Data System (ADS)

    Rusu, Eugen; Butunoiu, Dorin

    2015-04-01

    A multilevel wave modelling system, based on SWAN (Simulating Waves Nearshore) spectral model, was implemented in the Black Sea and focused on the western coast. Model simulations have been performed for a 10-year time interval (1999-2008). Validations have been carried out against both satellite data and in situ measurements. A high resolution SWAN computational domain (100m x100m), which is focused on the coastal environment south of the Danube Delta, was also implemented. This coastal area includes Sacalin, which is a newly formed island in the Black Sea, south of the Saint George branch of the Danube. Initially, this was an island system, which consisted of two smaller islands, Greater Sacalin and Lesser Sacalin. In time, due to the enhanced sedimentary processes, the two islands merged into a single continuous landmass. The island has become the habitat of a great variety of rare species and for this reason it was declared an ecological reserve. In the high resolution computational domain, focused on the Sacalin Island, the effect of the currents induced by the Danube River outflow was also accounted in the model, together with some other processes specific to the coastal environment as diffraction, triad wave-wave interactions and wave induced set up. Considering the results of the ten-year SWAN model simulations with the modelling system covering the entire sea basin, the most relevant configurations of the environmental matrix, characteristic to this side of the sea, were defined. On this basis, by performing SWAN simulations in the high resolution coastal domain, the wave propagation patterns in the nearshore, together with some parameters related to the shoreline conditions, were evaluated. A great number of possible situations were analyzed. The most relevant correspond to different directions of the incoming waves (N, NE, E and SE, respectively) and significant wave energy conditions. The results provided by the modelling system indicate two different

  15. Flood risk analysis model in the village of St. George/Danube Delta

    NASA Astrophysics Data System (ADS)

    Armas, I.; Dumitrascu, S.; Nistoran, D.

    2009-04-01

    River deltas may have been cradles for prehistoric civilizations (Day et al. 2007) and still represent favoured areas for human habitats on the basis of their high productivity, biodiversity and favourable economical conditions for river transport (Giosan and Bhattacharya 2005). In the same time, these regions are defined through their high vulnerability to environmental changes, being extremely susceptible to natural disasters, especially to floods. The Danube Delta, with an area of 5640 km2, is the largest ecosystem of the European humid zones. Its state reflects environmental conditions at both local and regional levels via liquid and solid parameters and has to ensure the water supply for the local economy and communities. Flooding of the delta is important for the dynamics of the entire natural system. Floods sustain both alluvial processes and the water supply to deltaic lakes. In addition, flooding frequency is important in flushing the deltaic lake system water, ensuring a normal evolution of both terrestrial and aquatic ecosystems. For human communities, on the other hand, floods are perceived as a risk factor, entailing material damage, human victims and psychological stress. In the perspective of risk assessment research, every populated place faces a certain risk engaged by a disaster, the size of which depends on the specific location, existent hazards, vulnerability and the number of elements at risk. Although natural hazards are currently a main subject of interest on a global scale, a unitary methodological approach has yet to be developed. In the general context of hazard analysis, there is the need to put more emphasis on the problem of the risk analysis. In most cases, it focuses only on an assessment of the probable material damage resulted from a specific risk scenario. Taking these matters into consideration, the aim of this study is to develop an efficient flood risk assessment methodology based on the example of the village of St. George in

  16. Storm driven evolution and morphodynamic feedbacks. Sacalin spit, Danube delta

    NASA Astrophysics Data System (ADS)

    Zăinescu, Florin I.; Vespremeanu-Stroe, Alfred; Tătui, Florin; Constantinescu, Ştefan

    2015-04-01

    Deltaic spits are among the most highly dynamic and vulnerable coastal landforms rapidly changing their dimension, plan position and morphology. Sacalin barrier spit formed at the southernmost Danube mouth (Sfântu Gheorghe arm), representing the youngest downdrift feature of the Sfântu Gheorghe deltaic lobe (1500 BP - present). Sacalin emerged in 1897 aided by a major flood and developed by backwards migration and by constant elongation (towards south). Its evolution took place during a strongly anthropogenic influenced period of record high (19th century, beginning of the 20th century) and low solid discharge (late 20th century, beginning of 21 century) which reflects large scale land use and hydrotechnical works in the Danube watershed. With the use of an extensive database consisting in: historical maps, satellite imagery, orthophotos, bathymetric and topographic surveys, LIDAR data, long-term wind speed measurements, long-term wave hindcast data and sediment discharge records, the current study sheds new light on the evolution and behavior of transgressive deltaic islands and spits, and also on the evolution of the downdrift part of the Sfantu Gheorghe lobe by linking morphologic change and climatic variation. The Sacalin cycle appears to be different from past cycles by developing further offshore from the river mouth and by achieving in its last stage of evolution, a flying spit morphology. The high shoreline mobility of the narrow and low Sacalin barrier is mainly driven by coastal storms and associated processes: longshore and cross-shore sediment transport, overtopping, washover fan building and sediment transport during breaching. The barrier spit was frequently breached in the central part and, episodically it experiences large elongation and retreat rates (up to 500 m/year and 80 m/year). The in depth analysis performed on the evolution indices in correspondence with the storm climate and storm-induced sediment transport indicate that the long term

  17. Modelling the Transfer and Retention of Nutrients in the Drainage Network of the Danube River

    NASA Astrophysics Data System (ADS)

    Garnier, J.; Billen, G.; Hannon, E.; Fonbonne, S.; Videnina, Y.; Soulie, M.

    2002-03-01

    The Danube catchment basin (817 000 km 2, 76×10 6 inhabitants) is the major freshwater contributor to the Black Sea (6300 m 3 s -1, 80% of the annual river discharge into the north-western Black Sea). The aim of the modelling approach developed for the Danube River, is to establish how land use and management of the whole watershed are linked to nutrient (N, P, Si) delivery and retention by the river. The approach uses an adaptation of the RIVERSTRAHLER model, which is based on a schematic representation of the drainage network deduced from geomorphological analysis by stream orders. The whole catchment was divided into 10 sub-basins and one branch, to provide a description satisfying both the need to take into account the heterogeneity of the system and the availability of constraints and validation data. On the basis of this description, a hydrological model was developed, which adequately simulated the seasonal variations of the discharge measured at the outlet of the basin. The model itself resulted from the coupling of the hydrological model with a biogeochemical model (RIVE), which takes into account the main ecological processes. It established a link between microscopic processes, their controlling factors and their macroscopic manifestations in terms of nutrient cycling and ecological functioning at the scale of the whole drainage network. The model was validated for the period from 1988 to 1991 on the basis of available observations of the major water-quality variables involved in the eutrophication processes (inorganic nutrients, phytoplankton biomass, dissolved oxygen, etc.). A reasonable agreement was found between the simulations of the model and the observations. Nutrient fluxes to the Black Sea, calculated for our reference period, are in the same range as those obtained via other approaches. Si/P and N/P ratios suggest silicon, rather than phosphorus, limitation for diatoms and phosphorus, rather than nitrogen, limitation for overall phytoplankton

  18. Holocene river history of the Danube: human-environment interactions on its islands in Hungary

    NASA Astrophysics Data System (ADS)

    Viczián, István; Balogh, János; Kis, Éva; Szeberényi, József

    2016-04-01

    A change in the frequency and magnitude of floods is the main response of river systems to climatic change. Natural floods are highly sensitive to even modest changes of climate. The discharge and the characteristics of floods basically determine the floodplain evolution and the feasibility of human land use and inhabitation on the islands and floodplains. The study revealed that those small islands of large rivers which have the surface rising only some meters above the river are particularly suitable research objects of Holocene climate variability as they are exposed to floods, react sensitively to environmental changes and their evolution may be paralleled with human history. The research area covers the islands of the Danube along the river between Komárom and Paks in Hungary, which is about 250 km, includes more than 50 smaller or formerly existing islands and two extensive islands: the Szentendre Island and Csepel Island. Data gathered from 570 archaeological sites of those islands from Neolithic to Modern Ages were analysed and interpreted in accordance with climate history and floodplain evolution. Nevertheless, the study is not only about river and its environmental history but it demonstrates the role of river and climatic variability in the history of mankind. The environment of the floodplain, the river hydrology, the sedimentation, the formation of islands and the incision and aggradation of surrounding riverbeds, the frequency of devastating floods have significantly changed through the historical time periods, which is reflected in the number and locations of archaeological sites on the islands. Their occupation history reflects the changes in discharge, climate, geomorphology, floods and human impacts and indicates historical periods with low or high probability of inundation. The most favourable periods for an island's occupation concerning the flood risk of its surfaces - and consequently of the banks along the river - are the first parts of a

  19. Environmental changes monitoring by remote sensing for Danube River Delta, Romania

    NASA Astrophysics Data System (ADS)

    Zoran, Maria

    2003-03-01

    Danube delta, one of the largest European wetlands left, lies predominantly in Romania, being considered a Biosphere Reservation. Environmental impact assessment and detection of spatio-temporal changes is needed for protection, conservation and restoration of the biological diversity specific to this area. Danube Delta wetlands and aquatic ecosystem are increasingly endangered by global or regional environmental changes due to the discharges or deposition of excess nutrients and/or harmful substances, to the reclamation of lands for agriculture, forestry, and engineering of water flows. A multitemporal data set consisting of LANDSAT MSS, TM and SAR-ERS1 images for Romanian Danube River Delta was used for comparing and mapping landcover change via change detection. The main aim of this paper is to conduct a comprehensive analysis based on existing historical and more recent data to establish the link between phytoplankton bloom development and related harmful phenomena in the North-Western part of Black Sea and changes in the Danube watershed (landuse, fertilizer utilization, waste water treatments). Based on satellite data were analyzed some test areas in the vicinity of the Danube mouths where the nutrient concentration were highest, being assimilated with an expected oxygen depletion, sulfate reduction and methanogenesis in the bottom waters and the superficial sediments.

  20. Web-based modelling of energy, water and matter fluxes to support decision making in mesoscale catchments??the integrative perspective of GLOWA-Danube

    NASA Astrophysics Data System (ADS)

    Ludwig, R.; Mauser, W.; Niemeyer, S.; Colgan, A.; Stolz, R.; Escher-Vetter, H.; Kuhn, M.; Reichstein, M.; Tenhunen, J.; Kraus, A.; Ludwig, M.; Barth, M.; Hennicker, R.

    The GLOWA-initiative (Global Change of the water cycle), funded by the German Ministry of Research and Education (BMBF), has been established to address the manifold consequences of Global Change on regional water resources in a variety of catchment areas with different natural and cultural characteristics. Within this framework, the GLOWA-Danube project is dealing with the Upper Danube watershed as a representative mesoscale test site (∼75.000 km 2) for mountain-foreland regions in the temperate mid-latitudes. The principle objective is to identify, examine and develop new techniques of coupled distributed modelling for the integration of natural and socio-economic sciences. The transdisciplinary research in GLOWA-Danube develops an integrated decision support system, called DANUBIA, to investigate the sustainability of future water use. GLOWA-Danube, which is scheduled for a total run-time of eight years to operationally implement and establish DANUBIA, comprises a university-based network of experts with water-related competence in the fields of engineering, natural and social sciences. Co-operation with a network of stakeholders in water resources management of the Upper Danube catchment ensures that practical issues and future problems in the water sector of the region can be addressed. In order to synthesize a common understanding between the project partners, a standardized notation of parameters and functions and a platform-independent structure of computational methods and interfaces has been established, by making use of the unified modelling language, an industry standard for the structuring and co-ordination of large projects in software development [Booch et al., The Unified Modelling Language User Guide, Addison-Wesley, Reading, 1999]. DANUBIA is object-oriented, spatially distributed and raster-based at its core. It applies the concept of “proxels” (process pixels) as its basic objects, which have different dimensions depending on the viewing

  1. The chemical control of Shorgum halepense (Johnson grass) in soybean culture in the Danube meadow.

    PubMed

    Poienaru, S; Sarpe, N; Sarpe, I

    2005-01-01

    Soybean cultures, especially those from the Danube Meadow, are very strongly infested with Johnson grass, which causes big damages, by the reduction of production with 40-85%, depending on the infestation degree. Before the synthesis of special herbicides for Johnson grass control, this species was controlled by practicing deep tilling, repeated operations with the disk, and, after the sprouting of soy plants, by mechanical and manual hoeings. In the Danube Waterside, the lack of labour force for the manual hoeing is very sharp. For this reason, it was generalized the enlarged use of herbicides for annual weed control (monocotyledonous and dicotyledonous), including Johnson grass. For the control of Johnson grass species, in the conditions of the Danube Meadow, the best results were obtained with the herbicides Fusilade Super, Targa Super, Agil and Select, and for the control of annual dicotyledonous species, with the herbicide Pivot 100LC.

  2. Large-Scale Water Resources Management within the Framework of GLOWA-Danube - Part B: The Water Supply Model

    NASA Astrophysics Data System (ADS)

    Nickel, D.; Barthel, R.; Schmid, C.; Braun, J.

    2003-04-01

    The research project GLOWA-Danube, financed by the German Federal Government, investigates long-term changes in the water cycle of the Upper Danube river basin in light of global climatic change. Its concrete aim is to build a fully integrated decision support tool that combines the competence of eleven different institutes in domains covering all major aspects governing the water cycle - from the formation of clouds to groundwater flow patterns to the behaviour of the water consumer. The research group "Water Supply" at the Institute of Hydraulic Engineering (IWS), Universitaet Stuttgart, has the central task of creating an agent-based model of the water supply sector. The Water Supply model will act as a link between the various physical models determining water quality and availability on the one hand and the actors models determining water demand on the other, which together form the tool DANUBIA. Ultimately, with the help of scenario testing, the water supply model will indicate the ability of the water supply system in the Upper Danube catchment to adapt to changing boundary conditions using different management approaches. The specific aim of the Water Supply model is the creation of a model which is not only able to simulate the present day system of water extraction, treatment and distribution but also its development and change with time. As most changes to the system are brought about by decisions made by relevant actors in the field of water management or their behaviour (in response to political and economic boundary conditions, changes in water demand or water quality, advances in technology etc.), the use of agent-based modelling was chosen, whereby an agent is seen as a computer system (in our case representing a human or group of humans) which is aware of its environment, has defined objectives and is able to act independently in order to meet these objectives. Whereas agent-based modelling has received much attention over the past decades, the use

  3. Danube delta environmental monitoring by multi-spectral and -temporal satellite data

    NASA Astrophysics Data System (ADS)

    Zoran, M.; Zoran, L. F.; Anderson, E.

    Danube Delta wetlands and aquatic ecosystem, endangered by global or regional environmental changes can be monitored by multi-spectral and -temporal satellite data ( LANDSAT MSS, TM , SPOT, MODIS, SAR -ERS by comparing and mapping land cover change via change detection . A comprehensive analysis based on existing historical and more recent data established the link between phytoplankton bloom development and related harmful phenomena (land use, fertiliser utilization, waste water treatments). Some test areas in the vicinity of the Danube mouths with highest nutrient concentration were analyzed.

  4. The applicability of an 87Sr/86Sr river isoscape to fish ecological questions in the Danube catchment

    NASA Astrophysics Data System (ADS)

    Zitek, A.; Irrgeher, J.; Sailer, K.; Trautwein, C.; Waidbacher, H.; Prohaska, T.

    2012-04-01

    Isoscapes are spatial maps of the distribution of isotopes on Earth. As a basis for ecological studies such as long distance migrations of animals or for determining the origin of food these tools are increasingly being developed, until now - mainly for terrestrial systems. In contrast, in case of aquatic systems only few maps were established up to now. As far as variation in the isotopic distribution in a studied area exists, the isotopic composition bears the potential to be used as natural tracer e.g. for ecological questions or food authentication. Above all the 87Sr/86Sr ratio taken up from the environment by organisms without any significant fractionation is known to provide a direct link to geologically distinct regions. Within the 'IsoMark' project (www.isomark.at), a database ('Isoscape Austria') containing all available spatially explicit isotope data (terrestrial and aquatic) with a focus on isotope distributions in Austrian rivers is being developed. Water samples from different rivers, mainly along the Danube in Austria, were collected and analyzed for their elemental and Sr isotopic composition. Analyses of water samples yielded several 'Isozones' along the Austrian part of the Danube, indicating diverse geology in these river catchments. Studying migration phenomena of fish using natural isotopic marks in hard parts is especially possible between these 'Isozones'. In geologically similar regions with little differences, element distributions or artificial marking methods (tagging, spiking) can serve as additional means. A significant positive relationship between the 87Sr/86Sr ratio in river water and the proportion of siliceous geological formations in the catchment was found on a national and European level. These analyses proved the possibility to predict the 87Sr/86Sr ratios in river catchments all over Europe. This relationship allows for an estimation of the applicability of the 87Sr/86Sr ratio for fish ecological questions on a European scale

  5. Modelling the Danube-influenced North-western Continental Shelf of the Black Sea. II: Ecosystem Response to Changes in Nutrient Delivery by the Danube River after its Damming in 1972

    NASA Astrophysics Data System (ADS)

    Lancelot, C.; Staneva, J.; van Eeckhout, D.; Beckers, J.-M.; Stanev, E.

    2002-03-01

    The ecological model BIOGEN, describing the carbon, nitrogen, phosphorus and silicon cycling throughout aggregated chemical and biological compartments of the planktonic and benthic marine systems, has been implemented in the north-western Black Sea to assess the response of this coastal ecosystem to eutrophication by the Danube River. The trophic resolution of BIOGEN was chosen to simulate the major ecological changes reported in this coastal area since the 1960s. Particular attention was paid to establishing the link between quantitative and qualitative changes in nutrients, phytoplankton composition and food-web structures. The BIOGEN numerical code structure includes 34 state variables assembled in five interactive modules describing the dynamics of (1) phytoplankton composed of three distinct groups, each with a different trophic fate (diatoms, nanophytoflagellates, non-silicified opportunistic species); (2) meso- and microzooplankton; (3) trophic dead-end gelatinous organisms composed of three distinct groups (the omnivorous Noctiluca and the carnivores Aurelia and the alien Mnemiopsis ), and organic matter degradation and associated nutrient regeneration processes by (4) planktonic and (5) benthic bacteria. The capability of the BIOGEN model to simulate the recent ecosystem changes reported for the Black Sea was demonstrated by running the model for the period 1985-1995. The BIOGEN code was implemented in an aggregated and simplified representation of the north-western Black Sea hydrodynamics. The numerical frame consisted of coupling a 0-D BIOGEN box model subjected to the Danube with a 1-D BIOGEN representing the open-sea boundary conditions. Model results clearly showed that the eutrophication-related problems of the north-western Black Sea were not only driven by the quantity of nutrients discharged by the Danube, but that the balance between them was also important. BIOGEN simulations clearly demonstrated that phosphate, rather than silicate, was the

  6. Assessment of the genotoxic potential along the Danube River by application of the comet assay on haemocytes of freshwater mussels: The Joint Danube Survey 3.

    PubMed

    Kolarević, Stoimir; Kračun-Kolarević, Margareta; Kostić, Jovana; Slobodnik, Jaroslav; Liška, Igor; Gačić, Zoran; Paunović, Momir; Knežević-Vukčević, Jelena; Vuković-Gačić, Branka

    2016-01-01

    In this study we assessed the level of genotoxic pollution along the Danube River by measuring the level of DNA damage in the haemocytes of freshwater mussels of Unio sp. (Unio pictorum/Unio tumidus) and Sinanodonta woodiana. The comet assay was used for the assessment of DNA damage. The research was performed on 34 out of 68 sites analysed within the Joint Danube Survey 3 - the world's biggest river research expedition of its kind in 2013. During research, 2285 river kilometres were covered with an average distance of 68 km between the sites. The complex data set on concentrations of various substances present in water, suspended particulate matter and sediment on investigated sites gave the opportunity to identify the groups of xenobiotics which mostly affect the studied biomarker - DNA damage. The highest levels of DNA damage were recorded in the section VI (Panonnian Plain), which is under the impact of untreated wastewater discharges. Both positive and negative influences of the large tributaries on the level of genotoxicity in the Danube River were evident. Significant correlation in response was detected between the studied species of freshwater mussels. The level of DNA damage in mussels correlated with concentrations of compounds from the group of hazardous priority substances (polycyclic aromatic hydrocarbons), persistent organic pollutants (dioxins) and emerging pollutants (Oxazepam, Chloridazon-desphenyl).

  7. The discharge of certain amounts of industrial microplastic from a production plant into the River Danube is permitted by the Austrian legislation.

    PubMed

    Lechner, Aaron; Ramler, David

    2015-05-01

    Numerous studies have quantified the amount of plastic litter in aquatic ecosystems and tried to assess its impacts and threats. This reflects a rising awareness of plastic as an environmental problem. As a next logical step, identifying and regulating the sources must be in the focus of scientific efforts. We report on a spillage of industrial microplastic (IMP) from a production plant situated at an Austrian Danube tributary. This is the first identified point source of IMP litter in freshwater systems. However, due to generous thresholds established by the Austrian government substantial amounts of IMP are legally introduced into running waters.

  8. The discharge of certain amounts of industrial microplastic from a production plant into the River Danube is permitted by the Austrian legislation.

    PubMed

    Lechner, Aaron; Ramler, David

    2015-05-01

    Numerous studies have quantified the amount of plastic litter in aquatic ecosystems and tried to assess its impacts and threats. This reflects a rising awareness of plastic as an environmental problem. As a next logical step, identifying and regulating the sources must be in the focus of scientific efforts. We report on a spillage of industrial microplastic (IMP) from a production plant situated at an Austrian Danube tributary. This is the first identified point source of IMP litter in freshwater systems. However, due to generous thresholds established by the Austrian government substantial amounts of IMP are legally introduced into running waters. PMID:25734504

  9. 26Al - 10Be cosmogenic nuclide isochron burial dating in combination with luminescence dating of two Danube terraces

    NASA Astrophysics Data System (ADS)

    Neuhuber, Stephanie; Braumann, Sandra; Lüthgens, Christopher; Fiebig, Markus; Häuselmann, Philipp; Schäfer, Jörg

    2016-04-01

    The Quaternary sediment record in the Vienna Basin is influenced by two main factors: (1) the tectonic development of a pull apart basin along a sinistral strike slip fault system between the Eastern Alps and the West Carpathians and by (2) strongly varying sediment supply during the Plio- and Pleistocene. From the Late Pannonian (8.8 Ma) onward a large-scale regional uplift (Decker et al., 2005) controls terrace formation in the Vienna Basin. The main sediment supply into the Vienna Basin originates from the Danube, and subordinately from tributaries to the south such as Piesting, Fischa, Leitha and from the north by the river March. Today the Danube forms a large floodplain that is bordered to the north by one large Pleistocene terrace, the Gänserndorf Terrace that is situated 17 m above todays water level. Farther to the east a smaller terrace, the Schlosshof Terrace, reaches 25 m above todays water level. These terrace levels are tilted by movement of underlying blocks (Peresson, 2006). Both, the Schlosshof and Gänserndorf terraces consist of successions of up to 2 m thick gravel beds with intercalated sand layers or -lenses that may locally reach thicknesses up to 0.8 m. At each terrace one gavel pit was selected to calculate the time of terrace deposition by luminescence dating in combination with 26Al/10Be cosmogenic nuclide isochrone dating (Balco and Rovery, 2008). Five quartz stones from the base of each terrace were physically and chemically processed to obtain Al and Be oxides for Acceleration Mass Spectrometry. Sand samples for luminescence dating were taken above the cosmogenic nuclide samples from the closest suitable sand body. Decker et al., 2005. QSR 24, 307-322 Peresson, 2006 Geologie der österreichischen Bundesländer Niederösterreich 255-258 Balco and Rovey, 2008. AJS 908, 1083-1114 Thanks to FWF P 23138-N19, OMAA 90öu17

  10. Assessment of Sediment Contamination, Toxicity and Benthic Community Composition in Ukrainian Part of Danube Delta

    EPA Science Inventory

    This study focused on identifying impaired and unimpaired areas (i.e., reference) within the Ukrainian portion of the Danube Delta using modern environmental diagnostic approaches and tools. To characterize the state of the areas under study, a triad approach was used including c...

  11. Narrating Regional Identity in Tourism--Sketches from the Austrian Danube Valley

    ERIC Educational Resources Information Center

    Ploner, Josef

    2009-01-01

    This article sketches the processes of regionalisation in the realm of present day tourism. By exploring issues of "regional culture" and "diversity" in Austria, and more particular, in the highly symbolic Danube valley "Wachau", the article shows how the imaginaries of contested cultural spaces--be they "regional", "national" or "European"--are…

  12. Evaluation of the Ecochemical Status of the Danube in Serbia in Terms of Water Quality Parameters

    PubMed Central

    Takić, Ljiljana; Mladenović-Ranisavljević, Ivana; Vuković, Milovan; Mladenović, Ilija

    2012-01-01

    The Danube is an international river passing partly through Serbia. The protection of the environment and sustainable use of water resources is a primary task that implies constant monitoring of the quality status and evaluation of ecochemical status of the water in the Danube basin. The investigation includes calculation of all-inclusive water quality by the Serbian water quality index (SWQI) method and an evaluation of eco-chemical status of the Danube water in terms of water quality parameters from the entry to the exit point along its course through Serbia in the year of 2009. The results show that the overall quality of the Danube water on the territory of Serbia corresponds to the descriptive indicator of “very good” water. According to the Council Directive75/440/EEC, the evaluation of the ecostatus, with slight deviation of individual parameters at Pančevo, corresponds to A1 category of the surface water quality intended for the abstraction of drinking water supplies in member states. PMID:22645471

  13. Winter and Spring Characterization of Particulate and Dissolved Organic Matter in the Danube Black Sea Mixing Zone

    NASA Astrophysics Data System (ADS)

    Saliot, A.; Derieux, S.; Sadouni, N.; Bouloubassi, I.; Fillaux, J.; Dagaut, J.; Momzikoff, A.; Gondry, G.; Guillou, C.; Breas, O.; Cauwet, G.; Deliat, G.

    2002-03-01

    The mixing zone between the Danube and the Black Sea was investigated at the front of the Chilia and Sulina branches of the Danube delta, in April-May 1997, during two periods corresponding to conditions at the end of winter (Chilia and Sulina branches) and the beginning of spring (Sulina branch). The distribution of the organic matter in the particulate, colloidal and truly dissolved pools along the salinity gradient was characterized at both global and molecular levels using biochemical parameters. The distribution of particulate organic carbon (POC) paralleled that of total suspended matter in winter, whereas decoupling was observed in spring, reflecting active biological mechanisms in the mixing zone off the Sulina branch during this period. This is supported by distribution patterns of polyunsaturated fatty acids (PUFA) and branched fatty acids (BrFA), which are indicators of phytoplankton and bacteria activities, respectively. The δ 13C isotopic signature of POC in the Danube-Black Sea mixing zone varied of between -29·1 and -24·6‰, which is consistent with the usual temperate range of estuarine systems. In spring, the observed shift towards lower values in the area of salinity 0-5 suggested a gradual change in the composition of POC, such as that caused by cell lysis of riverine planktonic populations induced by a salinity increase. A subsequent increase of δ 13C values towards higher salinities indicated phytoplankton growth in the estuarine/marine zone, as assessed by high concentrations of PUFA. Indirect evidence of sedimentation of terrestrial particles in the upper part of the salinity gradient in the range of 2-3 was suggested by the decrease of the content of particles and POC in fatty acids (C 24-C 32) and n-alkanes (C 25-C 35), both constituents of cuticular waxes of higher plants. A tight coupling was suggested between phytoplankton and bacteria by similar distributions of PUFA and BrFA along the salinity gradient. The distribution of

  14. Emergent shoreline behaviors reflected in the depositional history of wave-dominated deltas: Examples from Danube delta

    NASA Astrophysics Data System (ADS)

    Ashton, A. D.; Giosan, L.

    2006-12-01

    The shoreline reflects a critical transition in earth-surface processes and serves as a key marker for unraveling historic sedimentation patterns. Typically, variability in the shoreline position, particularly in the shore- perpendicular direction, is thought to be driven externally, for example through sea-level fluctuations or changes in fluvial sediment delivery. Here, we combine recent theoretical findings with field observations to demonstrate how shoreline variability, and its preservation in the sediment record, can arise spontaneously from littoral sediment transport processes alone. Not only can littoral processes generate their own periodic depositional signal, but they can potentially act as a dominant filter of signals of externally `forced' changes. Self-organized, emergent behavior, including the formation and reshaping of littoral barriers and the generation of alongshore pulses of sediment, can result in reorganizations of the coastal system and quasi-periodic depositional episodes not directly related to fluctuations of sediment supply or sea level. Recent investigations at the Danube Delta coast present a suite of such alongshore-heterogeneous behaviors that can be better understood in terms of instabilities in the plan-view shape of a coast due to waves approaching at oblique angles. At the St. George lobe, deposition of a river mouth bar can cause barrier emergence. Subsequent reworking by waves results in a downdrift extension of the nascent barrier, which serves as an alongshore conduit for coarse-load fluvial and coastal sediments. Overwash eventually leads to reconnection of both the mouth-proximal and -distal barrier ends. The morphology of several Danube lobes suggests that these episodic events control the depositional history of the downdrift lobe halves. Many aspects of the observed behavior of these littoral barriers, including their orientation with respect to the dominant wave climate, can be captured through numerical simulations

  15. The Danube Bend, Hungary - proposal for its recognition as a geoheritage

    NASA Astrophysics Data System (ADS)

    Karátson, Dávid

    2016-04-01

    The Danube Bend in North Hungary is a river curvature along the Danube river, cut into a rocky section that reveals Miocene volcanic sucessions. The deepest and narrowest part of the curvature, 5 km in diameter (called Visegrád Gorge), is one of the most picturesque landscapes in Hungary. There, the Danube, before changing its direction toward the south, forms a U-shaped valley in planform - a peculiar shape that has been an enigmatic issue in Hungarian earth sciences since the 19th century. A number of geomorphological theories have been put forward for the origin of the valley, which is incised between remnants of ca. 16 Ma old, small-sized dacitic stratovolcanoes of the Börzsöny Mts to the north, and the ~15 Ma Keserűs Hill lava dome complex to the south, all of which emerged in a contemporaneous archipelago (existent up to Pannonian times). According to Karátson et al. (2006), the U-shaped loop is partly inherited from a late-stage horseshoe caldera morphology of Keserűs Hill volcano, open to the north. Several Ma later, the formation of the Danube Bend was initiated by river incision, removing the post-volcanic sedimentary cover in mid- or rather, late Pleistocene times. Fluvial processes and erosion in turn were triggered by mountain uplift, climate changes, and drop of remote erosion base level. The present curvature of the river was controlled by the exhumation of the horseshoe caldera as well as the surrounding resistant volcaniclastic rocks (e.g. Visegrád Castle Hill) and a hilltop lava dome (Szent Mihály Hill). Moreover, an early-stage meander of Danube may have also inherited. The accelerated Late Quaternary erosion and intense dissection has resulted in a "re-birth" of the volcanic relief, which exhibits again steep slopes to form the spectacular gorge. At present, exposed rock formations (e.g. Vadálló-kövek) tower above the Danube Bend, making the area one of the most scenic landscape in East-Central Europe. Therefore, in 1997, the Danube

  16. Large-scale water resources management within the framework of GLOWA-Danube. Part A: The groundwater model

    NASA Astrophysics Data System (ADS)

    Barthel, Roland; Rojanschi, Vlad; Wolf, Jens; Braun, Juergen

    The research project GLOWA-Danube, financed by the German Federal Government, is investigating long-term changes in the water cycle of the upper Danube river basin (77,000 km 2) in light of global climatic change. Its aim is to build a fully integrated decision-support tool “DANUBIA” that combines the competence of 11 different research institutes in domains covering all major aspects governing the water cycle-from the formation of clouds, to groundwater flow patterns, to the behaviour of the water consumer. Both the influence of natural changes in the ecosystem, such as climate change, and changes in human behaviour, such as changes in land use or water consumption, are considered. DANUBIA is comprised of 15 individual disciplinary models that are connected via customized interfaces that facilitate network-based parallel calculations. The strictly object-oriented DANUBIA architecture was developed using the graphical notation tool UML (Unified Modeling Language) and has been implemented in Java code. All models use the same spatial discretisation for the exchange of data (1 × 1 km grid cells) but are using different time steps. The representation of a vast number of relevant physical and social processes that occur at different spatial and temporal scales is a very demanding task. Newly developed up- and downscaling procedures [Rojanschi, V., 2001. Effects of upscaling for a finite-difference flow model. Master’s Thesis, Institut für Wasserbau, Universität Stuttgart, Stuttgart, Germany] and a sophisticated time controller developed by the computer sciences group [Hennicker, R., Barth, M., Kraus, A., Ludwig, M., 2002. DANUBIA: A Web-based modelling and decision support system for integrative global change research in the upper Danube basin. In: GSF (Ed.), GLOWA, German Program on Global Change in the Hydrological Cycle Status Report 2002. GSF, Munich, pp. 35-38; Kraus, A., Ludwig, M., 2003. GLOWA-Danube Papers Technical Release No. 002 (Danubia Framework

  17. "Possible impacts of climate change on the Danube river along the Iron Gate gorge

    NASA Astrophysics Data System (ADS)

    Adamovic, M.

    2009-04-01

    The research was dedicated to foreseeing the possible impacts of climate change on water resources in eastern part of Serbia, along the Danube catchment. The Danube basin is in the eastern section of the considered RCM ( Regional climate model). For this purposes, the RCM EBU-POM according to the IPCC scenario A1B, was used in its representation of the hydrological balance over the Danube river basin along Iron Gate gorge, for the time frame 1961-1990 and 2071-2100. The Danube's catchment encompasses continental climate, as it is land-dominated by advection from the surrounding land areas. This part of Danube catchment is greatly affected by the Mediterranean climate, since the Danube runoff gives a relevant contribution of freshwater flux into the Mediterranean sea and it is dependent mostly on precipitated water of Mediterranean origin. On the other, the Dinaric-Balkan mountain chains in the west and the Carpathian mountain bow in the north and east, present distinctive morphological and climatic regions and barriers. The hydrological balance has been computed in two different, but in principle equivalent ways. The first approach, which has a more hydrological nuance, relies on establishing relationships between annual averages of the hydrological balance parameters (E, P, T) in order to get relevant coefficients. The second approach, which is more typically meteorological, relies on the calculation of the E for the time frame 2071-2100 by using the previous coefficients and getting runoff depth (h) and discharge (Q) as the final outputs. The results according to this model, show that the river flow of the Danube, in this part of its basin, will decrease over 50% with a great consequences to the dams Iron Gate I and II, their accumulations and ecosystems. Furthermore, if we take into account predictions made by IPCC which say that the south-east Europe will face temperature growth of 0.2 degrees in the next two decades for the range of SRES scenarios, makes the

  18. Microbiological water quality along the Danube River: integrating data from two whole-river surveys and a transnational monitoring network.

    PubMed

    Kirschner, Alexander K T; Kavka, Gerhard G; Velimirov, Branko; Mach, Robert L; Sommer, Regina; Farnleitner, Andreas H

    2009-08-01

    The River Danube is, with 2780 km, the second longest river in Europe. Its catchment area covers 801 500 km(2), with approximately 81 million inhabitants in 19 countries. River water for anthropogenic use, transportation and recreation is of major importance in all of these countries. Microbiological contamination from faecal pollution by anthropogenic sources is considered to be a crucial problem throughout the Danube River basin. Thus, detailed knowledge on the extent and the origin of microbial pollution is essential for watershed management. The determination of faecal indicator concentrations along the Danube and its major tributaries during two whole-river surveys and 16 permanent stations allowed for the first time to draw a clear picture of the faecal pollution patterns along the whole longitudinal profile of this important international river. By including a variety of environmental variables in statistical analysis, an integrative picture of faecal pollution in the Danube River basin could be evolved. Four hot spots and six stretches of differing faecal pollution were identified, mainly linked with input from large municipalities. Significant decline of microbiological pollution was observed in the upper and lower Danube stretches over the investigation period. In contrast, a significant increase in the middle part was evident. The planned implementation of new wastewater treatment plants and advanced wastewater treatment measures according to the European Union urban wastewater directive will have a great potential to reduce microbial faecal pollution in the Danube and thus improving water quality.

  19. Danube catchment water chemistry monitoring - elemental pattern determination from source to mouth using ICP-MS

    NASA Astrophysics Data System (ADS)

    Tchaikovsky, Anastassiya; Zitek, Andreas; Irrgeher, Johanna; Prohaska, Thomas

    2014-05-01

    Monitoring the elemental composition of river water is an important tool to determine the chemical status of a river. However, currently many studies are limited to the analysis of heavy metals included in the EU Water Framework Directive Priority Substances List (Cd, Hg, Ni, Pb). Yet, the assessment of further elements (e.g. Ca, Mg, Si) can give additional relevant information for understanding catchment processes such as soil erosion, weathering, hydrological changes or glacial melting. In addition, site specific "elemental pattern" can be used as tracer for ecological studies, like habitat and migration studies of fish or birds. Elemental information is of particular interest complementary to isotopic data where only little variability in the isotopic signatures can be observed. In this work, we investigated water samples collected from 68 sampling sites along the longitudinal course of the river Danube including the major tributaries during the Joint Danube Survey 3 (JDS3) in 2013. Water samples were obtained as triplicates in the middle of the river and analyzed using Inductively Coupled - Plasma Mass Spectrometry (ICP-MS). Method validation was performed using riverine water (NRC SLRS-5) certified reference material as well as in-house prepared quality control standards. Due to the diverse geology and changing natural and anthropogenic factors along the longitudinal course of the Danube, pronounced elemental variations among the water samples were documented. For instance, especially some major elements (Ca, K, Mg, Na) together with some minor elements (Si, Sr) are known to reflect in particular regional geological morphologies. In addition, the variation in Si/Ca ratios can be used as an indicator for weathering conditions, especially in the mountainous areas along the Danube. Elevated concentrations of Cd, Cu, Fe, Ni, and Pb downstream of some large cities and industrial areas are signs of significant anthropogenic impact. In combination, the chemical

  20. The 2006 Danube flood inundation patterns and the 1864 topographic map of South Romania: How the present hydrological processes are determined by the original landscape?

    NASA Astrophysics Data System (ADS)

    Timár, Gábor; Bartos, Zsombor; Imecs, Zoltán; Magyari-Sáska, Zsolt; Crăciunescu, Vasile; Flueraru, Cristian

    2014-05-01

    The satellite-based inundation maps of the 2006 Danube floods in Romania were fit geometrically to the 1864 topographic map sheets covering the Romanian regions of Oltenia and Muntenia. The old maps were systematically geo-referenced using the data of the original geodetic control and cartographic details; their Cassini-Soldner projection was properly parametrized and completed by the data of the original geodetic datum. The sheets were geo-referred using ground control points only at their four corners, knowing their coordinates in their own projection. The coupled satellite data was provided by the Landsat and MODIS data, all transformed to the modern grid system of Romania. The inundation patterns in the Danube embayments of Ghidici, Bechet and Calaraşi were analyzed on the historical map content layer. The comparison was made in two aspects: (1) how the low floodplain, inundated by the recent big flood was marked in the historical sheets, reflecting its old, almost original environmental setting, and (2) how the historical settlement outlines were changed during the passed 150 years, mostly because of the flood events. The comparison provide interesting examples about the inundation 'islands' during the flood and their original state as well as 'settlement moving' from the low and middle-level floodplain to the flood-free terraces. This work was supported by a grant of the Romanian National Authority for Scientific Research, CNCS - UEFISCDI, project number PN-II-RU-TE-2011-3-0125 and the Project NATO SfP 978016.

  1. Influence of hydropower dams on the composition of the suspended and riverbank sediments in the Danube.

    PubMed

    Klaver, Gerard; van Os, Bertil; Negrel, Philippe; Petelet-Giraud, Emmanuelle

    2007-08-01

    Large hydropower dams have major impacts on flow regime, sediment transport and the characteristics of water and sediment in downstream rivers. The Gabcikovo and Iron Gate dams divide the studied Danube transect (rkm 1895-795) into three parts. In the Gabcikovo Reservoir (length of 40km) only a part of the incoming suspended sediments were deposited. Contrary to this, in the much larger Iron Gate backwater zone and reservoir (length of 310km) all riverine suspended sediments were deposited within the reservoir. Subsequently, suspended sediments were transported by tributaries into the Iron Gate backwater zone. Here they were modified by fractional sedimentation before they transgressed downstream via the dams. Compared with undammed Danube sections, Iron Gate reservoir sediment and suspended matter showed higher clay contents and different K/Ga and Metal/Ga ratios. These findings emphasize the importance of reservoir-river sediment-fractionation.

  2. Pharmaceutical residues in the Danube River Basin in Serbia - a two-year survey.

    PubMed

    Radović, Tanja; Grujić, Svetlana; Dujaković, Nikolina; Radišić, Marina; Vasiljević, Tatjana; Petković, Anđelka; Boreli-Zdravković, Dulija; Dimkić, Milan; Laušević, Mila

    2012-01-01

    Pharmaceuticals are emerging contaminants with damaging effects to the environment and human health. Their presence in surface and especially groundwaters is regarded as detrimental, as they can ultimately reach drinking water. The aim of this work was to monitor pharmaceutical contamination of the Danube River and its tributaries in Serbia, and to assess the potential of their passing through all natural filtrations and reaching the groundwater. A total of 70 surface and groundwater samples was collected at 38 sampling sites at the Danube in Serbia. They were taken in five sampling campaigns performed in summer and autumn of 2009 and winter, spring and autumn of 2010. Samples were analyzed using a previously developed method which includes solid-phase extraction followed by liquid chromatography-tandem mass spectrometry.

  3. The chemical control of Sorghum halepense species in sunflower culture, in the Danube meadow.

    PubMed

    Poienaru, S; Sarpe, N; Sarpe, I

    2005-01-01

    In the latest years, sunflower was cultivated in Romania on an area of 800-900 thousand hectares. On 100 or 150 thousand hectares we find it cultivated also in agricultural farms in the Danube Meadow, because sunflower has favorable conditions on these soils, productions exceeding sometimes over 4000 kg/ha, of course, in irrigation conditions. In the Danube Meadow, the first experiments on Sorghum halepense (Johnson grass) species were performed by Fane Popa and colleagues (1986), at the agricultural station of Braila, using the herbicide Fusilade. In our experiments, the herbicide fusillade was compared with different more recently synthesized herbicides: Super, Pantera, Agil, Select, with the specific purpose of identifying the most favorable dose.

  4. Is reproductive effort environmentally or energetically controlled? The case of the Danube crested newt (Triturus dobrogicus).

    PubMed

    Cogălniceanu, Dan; Buhaciuc, Elena; Tudor, Marian; Rosioru, Daniela

    2013-11-01

    Reproductive strategies have evolved from a series of trade-offs between cost and timing of reproduction. We tested whether the reproductive effort of female Danube crested newts, Triturus dobrogicus, was environmentally or energetically constrained. We collected females migrating towards the water and kept them separately, with males. Deposited eggs were collected daily during the experiment. More eggs were deposited by older females and by females starting to reproduce earlier. Batches of eggs from females depositing more eggs had a lower hatching success, suggesting decreased viability. Oviposition lasted on average 22.7 days. Female newts showed no loss of weight during this period. At the end of the egg deposition period we injected a subset of females with hormones that triggered the deposition of additional eggs. This suggests that egg deposition in Danube crested newts is environmentally constrained, as females stopped oviposition despite having mature eggs in their ovaries.

  5. Spatial and temporal variability of stable isotopes and biological parameters for the Danube River in Serbia.

    PubMed

    Mitrovic, Tatjana; Obradovic, Vesna; Golobocanin, Dusan; Ogrinc, Nives; Miljevic, Nada

    2010-06-01

    This paper presents the results of hydrological, physicochemical, biological, and isotopic investigations of the Danube River along the stretch through Serbian territory conducted during four campaigns in September and November 2007, September 2008 and April 2009. The stable isotope values exhibited significant changes both in the Danube (-10.7 to-9.5 per thousand for delta(18)O and-73.7 to-67.1 per thousand for delta(2)H) and in its tributaries (-9.1 to-8.5 per thousand for delta(18)O and-69.4 to-59.4 per thousand for delta(2)H) depending on the time of survey, which could be partly attributed to the influences of seasonal effects. Results emphasise the dominant role of tributaries inflows from aquifers along the Danube. The very narrow range of delta(13)C(POC) (from-28.9 to-27.4 per thousand) was associated with relatively high C/N ratios (C/N>9), and together with delta(15)N(TPN) values, the date suggested that, in early spring, a major fraction of particulate organic matter was derived from allochthonous matter. An orthogonal varimax rotation of the principal components analysis identified four latent factors ('mineral related', 'biological', 'hardness', and 'soil inlets') which are responsible for the data structure covering 79% of the observed variations among the variables studied. A reliable grouping of samples with respect to the season was found.

  6. SENTINEL-1/2 Data for Ship Traffic Monitoring on the Danube River

    NASA Astrophysics Data System (ADS)

    Negula, I. Dana; Poenaru, V. D.; Olteanu, V. G.; Badea, A.

    2016-06-01

    After a long period of drought, the water level of the Danube River has significantly dropped especially on the Romanian sector, in July-August 2015. Danube reached the lowest water level recorded in the last 12 years, causing the blockage of the ships in the sector located close to Zimnicea Harbour. The rising sand banks in the navigable channel congested the commercial traffic for a few days with more than 100 ships involved. The monitoring of the decreasing water level and the traffic jam was performed based on Sentinel-1 and Sentinel-2 free data provided by the European Space Agency and the European Commission within the Copernicus Programme. Specific processing methods (calibration, speckle filtering, geocoding, change detection, image classification, principal component analysis, etc.) were applied in order to generate useful products that the responsible authorities could benefit from. The Sentinel data yielded good results for water mask extraction and ships detection. The analysis continued after the closure of the crisis situation when the water reached the nominal level again. The results indicate that Sentinel data can be successfully used for ship traffic monitoring, building the foundation of future endeavours for a durable monitoring of the Danube River.

  7. Rate of dune formation and sediment transfer in the past few hundred years on the Danube-Tisza Interfluve, Hungary

    NASA Astrophysics Data System (ADS)

    Schubert, Gábor; Sipos, György

    2010-05-01

    Environmental change let it be induced either by climatic or anthropogenic factors has had a key role in determining the rate of aeolian sediment transfer, on the highly sensitive landscape of the Danube-Tisza Interfluve, Hungary. The study area is located on a former alluvial fan of the Danube, abandoned by the river in the Late Pleistocene, and then reshaped by aeolian activity. The resultant dune fields were time to time reactivated during the Holocene and historical times. As this part of the Carpathian Basin is often stricken by droughts, anthropogenic factors, such as forest clearances and/or overgrazing could easily lead to the disturbance of morphological stability. These effects acted on a local level, however in certain historical periods they supposedly were more extended and general. An era of this type was the time of Turkish occupation (16th-17th c.) and the following two centuries. During the Turkish rule the territory was cleared of forests and became deserted. Following the slow recolonisation by people and vegetation the land was mainly used for grazing. There are numerous historical reports on repeated sand storms and wind erosional events. However, we have no concept on the true amount of sediment reworked these times and the rate of geomorphic change. The major aim of the present study is therefore to quantify the possible amount of sediment transfer in a wind blown depression-hummock system on the central part of the Danube-Tisza Interfluve during the past 500 years. The determination of dune formation and migration rate provides further insight into the active morphological processes of the region, and also highlights the possible geomorphic responses to environmental changes (mostly climatic) currently affecting the central part of the Carpathian Basin. Seven drillings were made on the chosen hummock and the adjacent blow out to set up the chronological framework of dune formation by the means of luminescence dating (OSL). The relatively

  8. Geochronology of Danube Delta sediments The PN-II-RU-TE-2012-3-0351 project

    NASA Astrophysics Data System (ADS)

    Robert-Csaba, Begy; Andra-Rada, Iurian; (Rusu) Oana Alexandra, Dumitru; Luminita, Preoteasa; Hedvig, Simon; Alida, Timar-Gabor; Szabolcs, Kelemen

    2014-05-01

    The sedimentation processes and the associated morphological changes within the Danube Delta and along the deltaic coast are complex and less understood.One of the main objectives of the project is the determination of sedimentation rates in several lacustrine units from the Danube Delta area, lakes in which the sedimentation rate clearly reflects the variation of the rivers solid discharge. Several undisturbed bottom lake sediments form the Danube Delta were extruded and the analysis of the vertical variation of the sedimentary facies, combined with 210Pb and 137Cs radiometric methods is undertaken in order to get a high resolution data of the sedimentation rates during the last one century. Additionally, sedimentation pattern in the proximity of the fluvial levees will be investigated for the first time at several locations in order to get insight into the lateral and temporal variations in sediment accumulation rates. Another objective is the assessment of the sedimentation rates on the Danubian continental shelf. This investigation will identify the tendency of the sediment deposition rates offshore of the closure depths during the last century and, more importantly, the main actual depocenters repartition and the associated sedimentation rates will be identified. The sedimentation rates data will contribute to the analysis of the sedimentary linkage between the river discharge, the longshore currents and the shoreline dynamics in order to isolate and quantify the role of the river solid discharge contribution to the long shore transport and to the shoreline dynamics and river distributaries mouth changes. The third objective is the geochronological investigation of the youngest deltaic lobes (Sfântu Gheorghe, Sfântu Gheorghe secondary delta, Chilia secondary delta) by means of luminescence dating in order to obtain a high accuracy of their evolution in time (e.g. last 3000 years). This study represents the first investigation of sedimentation rates and

  9. "An assessment of changes the Danube river flow along the Iron Gate gorge for XXI century

    NASA Astrophysics Data System (ADS)

    Adamovic, M.

    2009-04-01

    The research was dedicated to foreseeing the possible impacts of climate change on water resources in eastern part of Serbia, along the Danube catchment. The Danube basin is in the eastern section of the considered RCM ( Regional climate model). For this purposes, the RCM EBU-POM according to the IPCC scenario A1B, was used in its representation of the hydrological balance over the Danube river basin along Iron Gate gorge, for the time frame 1961-1990 and 2071-2100. The Danube's catchment encompasses continental climate, as it is land-dominated by advection from the surrounding land areas. This part of Danube catchment is greatly affected by the Mediterranean climate, since the Danube runoff gives a relevant contribution of freshwater flux into the Mediterranean sea and it is dependent mostly on precipitated water of Mediterranean origin. On the other, the Dinaric-Balkan mountain chains in the west and the Carpathian mountain bow in the north and east, present distinctive morphological and climatic regions and barriers. Prior to the assessment of changes of water resources of the Danube river, including the climate change effects, there was determined the terrain's spatial regionalization. Having been aware of the climatic-hydrologic and hydrographic homogeneity of regions, the whole territory of Serbia was divided into 20 units basins. The part of Danube basin in its eastern part, was subject of the research. For this balance unit, the main components of the balance equation of the water that included into the calculation are: precipitation P (mm), flow Q (m3/s), runoff depth h (mm), evaporation E (mm) and annual air temperature T (0C). The hydrological balance has been computed in two different, but in principle equivalent ways. The first approach, which has a more hydrological nuance, relies on establishing relationships between annual averages of the hydrological balance parameters (E, P, T) for the time frame 1961-1990 in order to get relevant coefficients

  10. "An assessment of changes the Danube river flow along the Iron Gate gorge for XXI century

    NASA Astrophysics Data System (ADS)

    Adamovic, M.

    2009-04-01

    The research was dedicated to foreseeing the possible impacts of climate change on water resources in eastern part of Serbia, along the Danube catchment. The Danube basin is in the eastern section of the considered RCM ( Regional climate model). For this purposes, the RCM EBU-POM according to the IPCC scenario A1B, was used in its representation of the hydrological balance over the Danube river basin along Iron Gate gorge, for the time frame 1961-1990 and 2071-2100. The Danube's catchment encompasses continental climate, as it is land-dominated by advection from the surrounding land areas. This part of Danube catchment is greatly affected by the Mediterranean climate, since the Danube runoff gives a relevant contribution of freshwater flux into the Mediterranean sea and it is dependent mostly on precipitated water of Mediterranean origin. On the other, the Dinaric-Balkan mountain chains in the west and the Carpathian mountain bow in the north and east, present distinctive morphological and climatic regions and barriers. Prior to the assessment of changes of water resources of the Danube river, including the climate change effects, there was determined the terrain's spatial regionalization. Having been aware of the climatic-hydrologic and hydrographic homogeneity of regions, the whole territory of Serbia was divided into 20 units basins. The part of Danube basin in its eastern part, was subject of the research. For this balance unit, the main components of the balance equation of the water that included into the calculation are: precipitation P (mm), flow Q (m3/s), runoff depth h (mm), evaporation E (mm) and annual air temperature T (0C). The hydrological balance has been computed in two different, but in principle equivalent ways. The first approach, which has a more hydrological nuance, relies on establishing relationships between annual averages of the hydrological balance parameters (E, P, T) for the time frame 1961-1990 in order to get relevant coefficients

  11. Invasive crayfish and crayfish plague on the move: first detection of the plague agent Aphanomyces astaci in the Romanian Danube.

    PubMed

    Pârvulescu, Lucian; Schrimpf, Anne; Kozubíková, Eva; Cabanillas Resino, Sara; Vrålstad, Trude; Petrusek, Adam; Schulz, Ralf

    2012-02-17

    Native European crayfish, such as Astacus leptodactylus, are threatened, among other factors, by the crayfish plague agent Aphanomyces astaci, dispersed by invasive North American crayfish. Two of these invaders, Pacifastacus leniusculus and Orconectes limosus, have extended their distribution in the River Danube catchment; the latter was detected for the first time in Romania in 2008. We monitored, at monthly intervals for over 2 yr, occurrence of native A. leptodactylus and invasive O. limosus at 6 sites on the Romanian Danube and checked for the invasive species in 4 of its tributaries. Between January 2009 and March 2011, the relative abundances of O. limosus steadily increased with time, while the native A. leptodactylus dramatically decreased in abundance. O. limosus expanded downstream at a rate of ca. 15 km yr-1; in August 2011, it was already present in the upper 105 km of the Romanian Danube. An agent-specific real-time PCR analyses demonstrated the presence of A. astaci DNA in at least 32% of the analysed invasive (n = 71) and 41% of the native (n = 49) crayfish coexisting in the Danube. Furthermore, A. astaci was also detected in A. leptodactylus captured about 70 km downstream of the O. limosus invasion front (at the time of sampling). Assuming a steady rate of expansion, O. limosus may invade the sensitive Danube delta area in the mid-2060s, even without long-distance dispersal. The crayfish plague agent, however, may reach the delta substantially earlier, through dispersal downstream among populations of native crayfish.

  12. Climate change adaptation options for sustainable management of agriculture in the Eastern Lower Danube Plain, Romania

    NASA Astrophysics Data System (ADS)

    Popovici, Elena-Ana; Sima, Mihaela; Balteanu, Dan; Dragota, Carmen-Sofia; Grigorescu, Ines; Kucsicsa, Gheorghe

    2013-04-01

    The current study was carried out within the FP7 ECLISE project in the Eastern Lower Danube Plain (Bărăgan Plain), one of the major agricultural areas in Romania. In this region, climate change signals are becoming more evident being predominantly characterized by increasing temperatures, decreasing of precipitations and intensification of extreme events in terms of frequency, intensity and duration. Over the past decades, the effects of extreme climatic phenomena on crop production have been ever more severe (very low outputs in the droughty years, significant crop losses during flooding periods, hailstorms, etc.). Concurrently, these effects have been the result of a whole range of complex interactions with other environmental, social, economic and political factors over the post-communist period. Using questionnaires survey for small individual households and large agricultural farms, focus group interviews and direct field observation, this study analyses the farmers' perception in terms of climate change, the impact of climate change on agriculture and how the farmers react and adapt to these changes. The current study have revealed that all farmers believe drought as being by far the most important climatic factor with major impact on agricultural production, followed by acid rains, hail storms and ground frost, facts evidenced also by the climatic diagnosis of the region. The majority of respondents have taken adaptation agricultural measures in response to changes in climate conditions (drought resistant seeds, modern technology to keep the moisture in the soil, etc.), but they consider that a national strategy for mitigating the effects of climate change would be more effective in this respect. Also, in order to correlate the farmers' perception of climate change and climatic factors, the authors used and processed a wide range of meteorological data (daily, monthly and annual from the most representative meteorological stations in the study-area), as

  13. Stratigraphic and lithologic characteristics of Pleistocene fluvial deposits in the Danube and Sava riparian area near Belgrade (Serbia)

    NASA Astrophysics Data System (ADS)

    Nenadić, D.; Gaudenyi, T.; Bogićević, K.; Tošović, R.

    2016-07-01

    The Quaternary sediments in the Danube and Sava riparian area near Belgrade have a considerable thickness. Several categories of deposits (fluvial-lacustrine, fluvial and aeolian) of Pliocene and Quaternary age have been identified. Their thickness, granulometric composition and paleontological features change depending on the distance from the recent Danube and Sava riverbeds. The Pleistocene fluvial deposits are underlain by sediments of the Late Miocene (Sarmatian and Pannonian) or the Plio-Pleistocene age, and are overlain by fluvial-palustrine deposits of the Pleistocene age and recent alluvial deposits. Pleistocene fluvial deposits that form a major part of the Quaternary sediments, have a great significance, since they are proved to be excellent collectors of ground water. Although these deposits are at lower altitudes in the area of Srem, they could be correlated with the high Danube and Morava terraces in Serbia and Drava in Croatia on the basis of their lithologic and paleontological features.

  14. Correlations of natural radionuclides in soil with those in sediment from the Danube and nearby irrigation channels.

    PubMed

    Krmar, M; Varga, E; Slivka, J

    2013-03-01

    The correlation between activity concentrations of some natural radionuclides ((238)U, (226)Ra, (232)Th, (40)K) measured in soil and in sediment taken from the Danube River and nearby irrigation channels was studied. The soil samples were collected from the northern part of Serbia and the sediment from the Serbian part of the Danube River and from the surrounding irrigation channels. The correlation between (238)U and other natural radionuclides in irrigation channel sediments was not as good as in the Danube. One of the possible explanations for this weak correlation can be the different chemical dynamics of (238)U in the irrigation channel sediment or changes of the (238)U activity concentration in irrigation channel sediment due to some human activities. The evaluation of ratios of activity concentrations of some natural radionuclides could be a more sensitive method for the determination of contaminant, rather than the straightforward analysis of activity concentrations.

  15. Analysis of solid waste from ships and modeling of its generation on the river Danube in Serbia.

    PubMed

    Ulniković, Vladanka Presburger; Vukić, Marija; Milutinović-Nikolić, Aleksandra

    2013-06-01

    This study focuses on the issues related to the waste management in river ports in general and, particularly, in ports on the river Danube's flow through Serbia. The ports of Apatin, Bezdan, Backa Palanka, Novi Sad, Belgrade, Smederevo, Veliko Gradiste, Prahovo and Kladovo were analyzed. The input data (number of watercrafts, passengers and crew members) were obtained from harbor authorities for the period 2005-2009. The quantities of solid waste generated on both cruise and cargo ships are considered in this article. As there is no strategy for waste treatment in the ports in Serbia, these data are extremely valuable for further design of equipment for waste treatment and collection. Trends in data were analyzed and regression models were used to predict the waste quantities in each port in next 3 years. The obtained trends could be utilized as the basis for the calculation of the equipment capacities for waste selection, collection, storage and treatment. The results presented in this study establish the need for an organized management system for this type of waste, as well as suggest where the terminals for collection, storage and treatment of solid waste from ships should be located.

  16. Impact of reduced anthropogenic emissions and century flood on the phosphorus stock, concentrations and loads in the Upper Danube.

    PubMed

    Zoboli, Ottavia; Viglione, Alberto; Rechberger, Helmut; Zessner, Matthias

    2015-06-15

    Patterns of changes in the concentration of total and soluble reactive phosphorus (TP, SRP) and suspended sediments at different flow levels from 1991 to 2013 in the Austrian Danube are statistically analyzed and related to point and diffuse emissions, as well as to extreme hydrological events. Annual loads are calculated with three methods and their development in time is examined taking into consideration total emissions and hydrological conditions. The reduction of point discharges achieved during the 1990s was well translated into decreasing TP and SRP baseflow concentrations during the same period, but it did not induce any change in the concentrations at higher flow levels nor in the annual transport of TP loads. A sharp and long-lasting decline in TP concentration, affecting all flow levels, took place after a major flood in 2002. It was still visible during another major flood in 2013, which recorded lower TP concentrations than its predecessor. Such decline could not be linked to changes in point or diffuse emissions. This suggests that, as a result of the flood, the river system experienced a significant depletion of its in-stream phosphorus stock and a reduced mobilization of TP rich sediments afterwards. This hypothesis is corroborated by the decoupling of peak phosphorus loads from peak maximum discharges after 2002. These results are highly relevant for the design of monitoring schemes and for the correct interpretation of water quality data in terms of assessing the performance of environmental management measures.

  17. Impact of reduced anthropogenic emissions and century flood on the phosphorus stock, concentrations and loads in the Upper Danube

    PubMed Central

    Zoboli, Ottavia; Viglione, Alberto; Rechberger, Helmut; Zessner, Matthias

    2015-01-01

    Patterns of changes in the concentration of total and soluble reactive phosphorus (TP, SRP) and suspended sediments at different flow levels from 1991 to 2013 in the Austrian Danube are statistically analyzed and related to point and diffuse emissions, as well as to extreme hydrological events. Annual loads are calculated with three methods and their development in time is examined taking into consideration total emissions and hydrological conditions. The reduction of point discharges achieved during the 1990s was well translated into decreasing TP and SRP baseflow concentrations during the same period, but it did not induce any change in the concentrations at higher flow levels nor in the annual transport of TP loads. A sharp and long-lasting decline in TP concentration, affecting all flow levels, took place after a major flood in 2002. It was still visible during another major flood in 2013, which recorded lower TP concentrations than its predecessor. Such decline could not be linked to changes in point or diffuse emissions. This suggests that, as a result of the flood, the river system experienced a significant depletion of its in-stream phosphorus stock and a reduced mobilization of TP rich sediments afterwards. This hypothesis is corroborated by the decoupling of peak phosphorus loads from peak maximum discharges after 2002. These results are highly relevant for the design of monitoring schemes and for the correct interpretation of water quality data in terms of assessing the performance of environmental management measures. PMID:25747371

  18. The Jaramillo Bottleneck for Migration of Hominins with Megaherbivores Into Europe via the Danube-Po Gateway

    NASA Astrophysics Data System (ADS)

    Muttoni, G.; Kent, D. V.; Scardia, G.

    2015-12-01

    Based on ongoing magnetostratigraphic work and updated critical reviews of sites bearing hominin remains and/or tools from greater Europe, including the Balkans and Greece, we maintain that the only compelling evidence of hominin presence in these regions was after the Jaramillo subchron (0.99 Ma), at about the time of the climatic late Early Pleistocene revolution (EPR) and the onset of enhanced glacial/interglacial activity from MIS 22 onward. Europe may have become initially populated during the EPR when, possibly for the first time in the Pleistocene, vast and exploitable ecosystems were generated along the Danube-Po Gateway in the Balkan peninsula and northern Italy. These newly formed settings, characterized by low-lands with open grasslands and reduced woody cover during glacial/interglacial transitions, represented the closest analogues to the savanna environment to which several large mammals linked with hominins in a common food web were adapted and could use as a migratory corridor. We acknowledge that lack of evidence may not be a compelling argument, but the absence of the Jaramillo and out-of-sequence cosmogenic nuclide dates with wide error margins in key sections preclude the use of such evidence to substantiate the presence of humans (and presumably associated biostratigraphic markers) prior to the Jaramillo, and thus logically deny applying such conclusions to other systems.

  19. Analysis of solid waste from ships and modeling of its generation on the river Danube in Serbia.

    PubMed

    Ulniković, Vladanka Presburger; Vukić, Marija; Milutinović-Nikolić, Aleksandra

    2013-06-01

    This study focuses on the issues related to the waste management in river ports in general and, particularly, in ports on the river Danube's flow through Serbia. The ports of Apatin, Bezdan, Backa Palanka, Novi Sad, Belgrade, Smederevo, Veliko Gradiste, Prahovo and Kladovo were analyzed. The input data (number of watercrafts, passengers and crew members) were obtained from harbor authorities for the period 2005-2009. The quantities of solid waste generated on both cruise and cargo ships are considered in this article. As there is no strategy for waste treatment in the ports in Serbia, these data are extremely valuable for further design of equipment for waste treatment and collection. Trends in data were analyzed and regression models were used to predict the waste quantities in each port in next 3 years. The obtained trends could be utilized as the basis for the calculation of the equipment capacities for waste selection, collection, storage and treatment. The results presented in this study establish the need for an organized management system for this type of waste, as well as suggest where the terminals for collection, storage and treatment of solid waste from ships should be located. PMID:23460543

  20. Modelling Vegetation Response to Climate Change in the Upper Danube Subcatchment applying a Biophysical Landsurface Model.

    NASA Astrophysics Data System (ADS)

    Hank, T.; Mauser, W.

    2009-04-01

    The manifold exchange processes that occur between landsurface and atmosphere are largely determined through the living vegetation cover that dynamically responds to atmospheric conditions such as humidity, temperature or the concentration of carbon dioxide respectively. When dealing with the mapping of biospheric feedbacks on changing climatic conditions, the numerical description of the involved processes represents a helpful tool and reliable instrument for the investigation of the dynamics that are part of these landsurface exchange cycles. A considerable number of current studies concentrates on the modelling of global dynamic reactions of the vegetation cover on changing atmospheric parameters. Nonetheless, questions concerning the regional effects of climate change are getting more and more important for stakeholders and decision makers worldwide. Within the scope of the GLOWA-Danube cooperative project, which is funded by the German Federal Ministry of Education and Research (BMB+F), the physically-based hydrological model PROMET (process of radiation mass and energy transfer) is applied to investigate the consequences of climate change on the regional scale. PROMET largely represents the landsurface component of the DANUBIA decision support system, which has been recently enhanced by an explicit model of photosynthesis. The assimilation model was combined with a model of stomatal conductance and the respective physiological submodels to enable a spatial modelling of active vegetation growth, taking the sensitivity of the photosynthetic apparatus with respect to changing atmospheric conditions into account. The combined model approach was applied to a set of climate scenarios, all tracing the characteristics of the moderate IPCC A1B scenario, but featuring different realizations of this storyline. The meteorology for the scenario runs was generated, using a stochastic method that is based on a statistical analysis and rearrangement of measured

  1. Assessment of the contamination of riparian soil and vegetation by trace metals--A Danube River case study.

    PubMed

    Pavlović, P; Mitrović, M; Đorđević, D; Sakan, S; Slobodnik, J; Liška, I; Csanyi, B; Jarić, S; Kostić, O; Pavlović, D; Marinković, N; Tubić, B; Paunović, M

    2016-01-01

    The aim of this study was to assess the spatial distribution of arsenic and heavy metals (Cd, Cr, Cu Hg, Ni, Pb and Zn) in a riparian area influenced by periodical flooding along a considerable stretch of the Danube River. This screening was undertaken on soil and plant samples collected from 43 sites along 2386 km of the river, collected during the international Joint Danube Survey 3 expedition (ICPDR, 2015). In addition, data on the concentration of these elements in river sediment was used in order to describe the relationship between sediment, riparian soil and riparian plants. A significant positive correlation (Spearman r, for p<0.05) was found for trace metal concentrations in river sediment and soil (r=0.817). A significant correlation between soil and plants (r=0.438) and sediment and plants (r=0.412) was also found for trace metal concentrations. Elevated levels of Cd, Cr, Cu, and Ni were found at certain sites along the Serbian stretch, while elevated concentrations of Hg were also detected in Hungary, of Pb along the Romanian stretch and of As along the Bulgarian stretch (the Lower Danube). These results point to the presence of naturally-occurring metals derived from ore deposits in the Danube River Basin and anthropogenic metals, released by mining and processing of metal ores and other industrial facilities, which are responsible for the entry of metals such as Cu, Ni and Zn. Our results also indicated toxic Cd and Zn levels in plant samples, measured at the Hercegsznato site (Middle Danube, Hungary), which highlighted these elements as a potential limiting factor for riparian vegetation in that area. The distribution of the analysed elements in plant material also indicates the species-specific accumulation of trace metals. Based on our results, the Lower and Middle Danube were found to be more polluted in terms of the analysed elements.

  2. Assessment of the contamination of riparian soil and vegetation by trace metals--A Danube River case study.

    PubMed

    Pavlović, P; Mitrović, M; Đorđević, D; Sakan, S; Slobodnik, J; Liška, I; Csanyi, B; Jarić, S; Kostić, O; Pavlović, D; Marinković, N; Tubić, B; Paunović, M

    2016-01-01

    The aim of this study was to assess the spatial distribution of arsenic and heavy metals (Cd, Cr, Cu Hg, Ni, Pb and Zn) in a riparian area influenced by periodical flooding along a considerable stretch of the Danube River. This screening was undertaken on soil and plant samples collected from 43 sites along 2386 km of the river, collected during the international Joint Danube Survey 3 expedition (ICPDR, 2015). In addition, data on the concentration of these elements in river sediment was used in order to describe the relationship between sediment, riparian soil and riparian plants. A significant positive correlation (Spearman r, for p<0.05) was found for trace metal concentrations in river sediment and soil (r=0.817). A significant correlation between soil and plants (r=0.438) and sediment and plants (r=0.412) was also found for trace metal concentrations. Elevated levels of Cd, Cr, Cu, and Ni were found at certain sites along the Serbian stretch, while elevated concentrations of Hg were also detected in Hungary, of Pb along the Romanian stretch and of As along the Bulgarian stretch (the Lower Danube). These results point to the presence of naturally-occurring metals derived from ore deposits in the Danube River Basin and anthropogenic metals, released by mining and processing of metal ores and other industrial facilities, which are responsible for the entry of metals such as Cu, Ni and Zn. Our results also indicated toxic Cd and Zn levels in plant samples, measured at the Hercegsznato site (Middle Danube, Hungary), which highlighted these elements as a potential limiting factor for riparian vegetation in that area. The distribution of the analysed elements in plant material also indicates the species-specific accumulation of trace metals. Based on our results, the Lower and Middle Danube were found to be more polluted in terms of the analysed elements. PMID:26184864

  3. Longitudinal changes in the bacterial community composition of the Danube River: a whole-river approach.

    PubMed

    Winter, Christian; Hein, Thomas; Kavka, Gerhard; Mach, Robert L; Farnleitner, Andreas H

    2007-01-01

    The Danube River is the second longest river in Europe, and its bacterial community composition has never been studied before over its entire length. In this study, bacterial community composition was determined by denaturing gradient gel electrophoresis (DGGE) analysis of PCR-amplified portions of the bacterial 16S rRNA gene from a total of 98 stations on the Danube River (73 stations) and its major tributaries (25 stations), covering a distance of 2,581 km. Shifts in the bacterial community composition were related to changes in environmental conditions found by comparison with physicochemical parameters (e.g., temperature and concentration of nutrients) and the concentration of chlorophyll a (Chl a). In total, 43 distinct DGGE bands were detected. Sequencing of selected bands revealed that the phylotypes were associated with typical freshwater bacteria. Apparent bacterial richness in the Danube varied between 18 and 32 bands and correlated positively with the concentration of P-PO(4) (r = 0.56) and negatively with Chl a (r = -0.52). An artificial neural network-based model explained 90% of the variation of apparent bacterial richness using the concentrations of N-NO(2) and P-PO(4) and the distance to the Black Sea as input parameters. Between the cities of Budapest and Belgrade, apparent bacterial richness was significantly lower than that of other regions of the river, and Chl a showed a pronounced peak. Generally, the bacterial community composition developed gradually; however, an abrupt and clear shift was detected in the section of the phytoplankton bloom. Large impoundments did not have a discernible effect on the bacterial community of the water column. In conclusion, the riverine bacterial community was largely influenced by intrinsic factors.

  4. Effects of Reservoirs on Nutrient Concentrations and Ratios along the Longitudinal Gradient of Danube River Basin

    NASA Astrophysics Data System (ADS)

    Salcedo Borda, J. S.; Gettel, G. M.; Irvine, K.

    2015-12-01

    Reservoirs reduce water flow and increase the retention time which can provide conditions to increase primary production, sedimentation and nutrient retention. As a consequence, nutrient ratios and fluxes of nitrogen (N), phosphorus (P), and silica (Si) may be altered which in turn affects the identity of limiting nutrients and the dynamics of primary production in downstream ecosystems. Residence time as well as the position of reservoirs along the longitudinal gradient (headwaters vs. mouth) may affect these processes. The Danube River Basin is one example where reservoirs have likely altered nutrient stoichiometry along the longitudinal gradient. It has a dam every 17 Km in the upper 1000 km of the river along with a very large dam complex (Iron Gates Dam) 117- Km from the mouth. There has been there has been an observed decline in Si flux, which may have led to changes in phytoplankton community structure in the Black Sea, but for which the causes for this decline are not yet clear. The purpose of this study is to examine the effects of reservoirs from headwaters to the mouth on nutrient stoichiometry in the Danube Basin. Data on dissolved Si, N, and P concentrations from 1996 to 2012 were analyzed from 40 monitoring stations from the TransNational Monitoring Network (TNMN), which are located in the main stem of the Danube. Time series analysis is used to compare nutrient concentrations and ratios both through seasons and through the 15 year time-period. The monitoring stations are located above and below reservoirs in order to analyze the effect of reservoirs on nutrient ratios and fluxes. Preliminary results show that relationship of dissolved inorganic N (DIN): soluble reactive P (SRP) range from 207 to 76, while DIN:Si ratio ranges from 1.89 to 0.2 from the headwaters to the mouth.

  5. Fluvial connectivity and climate: A comparison of channel pattern and process in two climatically contrasting fluvial sedimentary systems in South Africa

    NASA Astrophysics Data System (ADS)

    Grenfell, S. E.; Grenfell, M. C.; Rowntree, K. M.; Ellery, W. N.

    2014-01-01

    The aim of this research was to investigate the dynamics of valley formation, sediment delivery and channel pattern in two climatically contrasting fluvial sedimentary systems in South Africa. Each system comprised a network of headwater valley fills and floodplains underlain by sedimentary Karoo Supergroup rocks that are intersected by resistant dolerite dykes and sills. The Seekoei River Floodplain and Gordonville valley fill site in the Great Karoo, however, experience less than half the annual precipitation of the Nsonge River Floodplain and Hlatikhulu valley fill in the KwaZulu-Natal Drakensberg Foothills. Furthermore, rainfall is more variable in the Karoo. Despite climatic differences, headwater valley fills were geomorphically similar. In contrast, floodplains in the two regions were vastly different, even when the same downstream control (a resistant dolerite intrusion crossing the drainage line) was considered. Upstream of a dolerite dyke, the Nsonge River is highly sinuous and located in a wide floodplain that has been carved by lateral planation of the underlying bedrock. In comparison, the Seekoei River, located upstream of a dolerite sill, is discontinuous and characterized by floodouts and avulsing distributaries that undergo periods of bedrock incision, followed by infilling.It is likely that this disparity is caused by the inability of infrequent, unsustained flows to develop meanders and, thus, adjust the channel planform to changes in discharge, sediment load and valley slope. Flow variability, thus, exercises a strong control on channel pattern and causes floodouts in headwater settings and the semi-arid Karoo floodplain. As a result, sediment transport in the Seekoei River is likely to be episodic, and net retention of sediment in the semi-arid floodplain is greater than in the sub-humid Nsonge River Floodplain, where sediment depth is limited.

  6. Estimation of suspended loads in the Danube River at Göd (1668 river km), Hungary

    NASA Astrophysics Data System (ADS)

    Tóth, Bence; Bódis, Erika

    2015-04-01

    Sediment rating curves were used to estimate suspended particulate matter (SPM) loads in the Danube River at Göd (1668 river km), Hungary, in conjunction with a sampling program conducted between 2003 and 2012. Contrary to its water quality significance, only a few studies have focused on the annual transport of SPM in this section of the river. Based on the results, we can state that (1) the SRC method (in certain cases with correction factors) provided reliable estimates of the annual SPM loads in this section of the river; (2) the division of the dataset into seasonal or temperature subsets did not significantly improve the estimations, moreover, annual datasets may provide additional hydrologic information on the water year or the annual water regime; (3) large amounts of the SPM were transported during short, but high water discharge periods, hence, calendar based-sampling should be supplemented with event-based sampling, and (4) the SPM load of the river has declined by about 50% over previous decades, which is most likely due to the installation of hydropower plants on the upper (German, Austrian, Slovakian) stretches of the Danube River.

  7. Socio-economic features of commercial fishery in the bordering upper Danube River area of Serbia.

    PubMed

    Smederevac-Lalić, Marija; Pešić, Radmilo; Cvejić, Slobodan; Simonović, Predrag

    2012-05-01

    The multidisciplinary socio-economic study of fisheries in the bordering part of the Danube River between Serbia and Croatia (at the following sites: Apatin, Bačka Palanka, Bačko Novo Selo, Bezdan, and Sombor) that was performed in order to investigate various aspects of fish resource utilization (management, policy of protection and exploitation of freshwater fishery resources, present fisheries legislation, catch statistics), was realized during 2004 and 2005. Data were collected via survey with a structured interview. Socio-economic circumstances, together with ecological factors, have had an influence on the fish stock and number of commercial fishermen. Awareness of the occurring problems, both economic and ecological ones, is apparent, regardless of whether it is assessed in the field of commercial or recreational fishing. Fishery sector in Serbia is in a prolonged process of transition, with the enforcement of fishing regulations, but also the lack of control that leaves space for illegal commercial fishing. The statements, consciousness, experience and behavior of commercial fishermen represent a good basis for planning the sustainable development of fishing in this section of the Danube River.

  8. Joint modelling of flood peaks and volumes along the Danube River

    NASA Astrophysics Data System (ADS)

    Kohnova, Silvia; Papaioannou, George; Bacigal, Tomas; Jeneiova, Katarina; Szolgay, Jan; Loukas, Athanasios

    2016-04-01

    Flood frequency analysis is usually performed as univariate analysis of flood peaks using a suitable theoretical probability distribution of annual maximum flood peaks. However, other flood attributes, such as flood volume and duration, are necessary for the design of hydrotechnical projects. In this study, various copula families have been applied to bivariate analysis of discharge and volume in extreme flood incidents modelling. Streamflow data from numerous gauged stations of the Danube River have been used. The methodology consists of a combination of Annual Maximum Flood peaks (AMF) with corresponding volumes and independent annual maximum volumes of fixed duration at 5,10,15,20,25,30 and 60 days, respectively. The Kendall's tau coefficient quantifies the correlation in distinct discharge-volume settings. The Archimedean (e.g. Frank, Clayton and Ali-Mikhail-Haq) copulas revealed to be more capable for bivariate modeling of floods than the other examined copula families at the Danube River. Results showed in general that copulas are effective tools for bivariate modeling of the two random variables studied.

  9. Assessing the potential skill of seasonal streamflow forecasting for the River Rhine and the Upper Danube Basin

    NASA Astrophysics Data System (ADS)

    Klein, B.; Meissner, D.; Gerl, N.; Hemri, S.; Gneiting, T. J.

    2013-12-01

    Reliable seasonal streamflow forecasts could be a valuable tool for the medium-term to long-term planning of many users of the water sector. Especially for the optimization of hydropower generation and the water-related logistic transportation chain the knowledge about the possible future evolution of streamflows within the next 1 to 6 months would be an important additional information in the decision process. Although there is a strong need for seasonal forecast products there is no operational forecasting system available for the large rivers in Germany. One of the main reasons is that the long-term meteorological predictability, especially for precipitation, is quite limited over Central Europe. Potential gain of predictability in the hydrological system that makes us believe that skillful seasonal streamflow forecasts in Central Europe are not out of reach is the hydrological memory and the delayed and damped system response of river basins. Natural (like snow pack, groundwater, soil moisture) as well as man-made reservoirs and dams have a large influence on the future runoff. In hydrological forecasting this memory is represented by the initial conditions of the hydrological model. In addition the streamflow at a gauge is an integrated system response with the meteorological variables as system input. If there is at least some valuable information in the numeric seasonal weather forecasts about the future evolution of precipitation and temperature as the main drivers of the hydrological processes, it could be possibly assessed through spatial (considering larger catchments) and temporal aggregation (e.g. monthly mean runoff values instead of daily values). In this contribution the potential skill of seasonal streamflow forecasting is evaluated for River Rhine and the Upper Danube Basin (up to the gauge Vienna). Different spatial and temporal scales are considered as well as different meteorological forcings. Two different hydrological models are applied in

  10. Genetic variation in brown trout Salmo trutta across the Danube, Rhine, and Elbe headwaters: a failure of the phylogeographic paradigm?

    PubMed Central

    2013-01-01

    Background Brown trout Salmo trutta have been described in terms of five major mtDNA lineages, four of which correspond to major ocean basins, and one, according to some authors, to a distinct taxon, marbled trout Salmo marmoratus. The Atlantic and Danubian lineages of brown trout meet in a poorly documented contact zone in Central Europe. The natural versus human mediated origin of the Atlantic lineage in the upper Danube is a question of both theoretical and practical importance with respect to conservation management. We provide a comprehensive population genetic analysis of brown trout in the region with the aim of evaluating the geographic distribution and genetic integrity of these two lineages in and around their contact zone. Results Genetic screening of 114 populations of brown trout across the Danube/Rhine/Elbe catchments revealed a counter-intuitive phylogeographic structure with near fixation of the Atlantic lineage in the sampled portions of the Bavarian Danube. Along the Austrian Danube, phylogeographic informative markers revealed increasing percentages of Danube-specific alleles with downstream distance. Pure Danube lineage populations were restricted to peri-alpine isolates within previously glaciated regions. Both empirical data and simulated hybrid comparisons support that trout in non-glaciated regions north and northeast of the Alps have an admixed origin largely based on natural colonization. In contrast, the presence of Atlantic basin alleles south and southeast of the Alps stems from hatchery introductions and subsequent introgression. Despite extensive stocking of the Atlantic lineage, little evidence of first generation stocked fish or F1 hybrids were found implying that admixture has been established over time. Conclusions A purely phylogeographic paradigm fails to describe the distribution of genetic lineages of Salmo in Central Europe. The distribution pattern of the Atlantic and Danube lineages is extremely difficult to explain without

  11. Forty years of vegetation change on the Missouri River Floodplain

    USGS Publications Warehouse

    Johnson, W.C.; Dixon, M.D.; Scott, M.L.; Rabbe, L.; Larson, G.; Volke, M.; Werner, B.

    2012-01-01

    Comparative inventories in 1969 and 1970 and in 2008 of vegetation from 30 forest stands downstream of Garrison Dam on the Missouri River in central North Dakota showed (a) a sharp decline in Cottonwood regeneration; (b) a strong compositional shift toward dominance by green ash; and (c) large increases in invasive understory species, such as smooth brome, reed canary grass, and Canada thistle. These changes, and others discovered during remeasurement, have been caused by a complex of factors, some related to damming (altered hydrologic and sediment regimes, delta formation, and associated wetdry cycles) and some not (diseases and expansion of invasive plants). Dominance of green ash, however, may be short lived, given the likelihood that the emerald ash borer will arrive in the Dakotas in 510 years, with potentially devastating effects. The prospects for recovery of this valuable ecosystem, rich in ecosystem goods and services and in American history, are daunting. ?? 2012 by American Institute of Biological Sciences. All rights reserved.

  12. Forty years of vegetation change on the Missouri River floodplain

    USGS Publications Warehouse

    Johnson, W. Carter; Dixon, Mark D.; Scott, Michael L.; Rabbe, Lisa; Larson, Gary; Volke, Malia; Werner, Brett

    2012-01-01

    Comparative inventories in 1969 and 1970 and in 2008 of vegetation from 30 forest stands downstream of Garrison Dam on the Missouri River in central North Dakota showed (a) a sharp decline in Cottonwood regeneration; (b) a strong compositional shift toward dominance by green ash; and (c) large increases in invasive understory species, such as smooth brome, reed canary grass, and Canada thistle. These changes, and others discovered during remeasurement, have been caused by a complex of factors, some related to damming (altered hydrologic and sediment regimes, delta formation, and associated wet-dry cycles) and some not (diseases and expansion of invasive plants). Dominance of green ash, however, may be short lived, given the likelihood that the emerald ash borer will arrive in the Dakotas in 5-10 years, with potentially devastating effects. The prospects for recovery of this valuable ecosystem, rich in ecosystem goods and services and in American history, are daunting.

  13. Great Danube flood peak of the late medieval - early modern transition: the 1470s-1520s

    NASA Astrophysics Data System (ADS)

    Kiss, Andrea

    2016-04-01

    As a consequence of very detailed contemporary documentation, namely legal-administrative documentation (charters) and the annual (or daily) information available in the Bratislava accounts (mainly bridgemasters' accounts), a relatively detailed picture of a massive flood peak can be detected in the Carpathian Basin documentation concerning the decades of the late 15th and early 16th centuries. These decades are one of the most important period in the millennial flood history of the Danube in this area: both concerning the number of individual flood events and regarding the information on multiannual problems. Moreover, archaeological evidence, for example the flood sediment layers in Visegrád and also the damages, structural and elevation changes of renovated buildings in Buda or along the Upper-Danube, provide similar examples of multiannual flood-related problems. Moreover, clear flood peaks can be also detected at this time on the Austrian sections of the Danube, but especially on its Eastern Alpine tributaries, centred around the 1480s and the greatest flood events of 1501, and also partly of 1503 and 1508 (best documented for the Traun at Wels: see Rohr 2007, 2013). In the poster presentation on the one hand a general overview of the documented flood events and multiannual flood-related information - based on documentary and archaeological evidence -, occurred in the Carpathian Basin are presented regarding frequency, magnitude (3-scaled classification) and seasonality information (when available). On the other hand, differences in flood frequencies, flood types and seasonality is also separately discussed on an annual and decadal scale: while, for example, in the drought-affected 1470s were characterised by ice jam floods, the great flood peak of the 1480s were both rich in ice jams and summer-flood events (with a peak in 1485 with 4 great floods). The decade of the 1500s was mainly influenced by the 1501 "deluge" and further two great flood events (and

  14. Preliminary paleoecological reconstruction of long-term relationship between human and environment in the northern part of Danube-along Plain, Hungary

    NASA Astrophysics Data System (ADS)

    Kustár, Rozália; Molnár, Dávid; Sümegi, Pál; Törőcsik, Tünde; Sávai, Szilvia

    2016-06-01

    The peat bog at Ócsa is located at the northern part of the Danube-Tisa Interfluves at the transitional zone of two landscapes with different morphological characters. At the boundary of the Danube-Tisa Interfluves and the Danube-along Plain a marshland sequence can be found from Hajós to Ócsa. We extended our research to the Ócsa peat bog to complete the environmental historical investigations in the examined area, as well. The bog is located in a former pool formed by the Danube River in which aeolian sand and thick lake sediment deposited from the Late Pleistocene. The initial oligotrophic lake became mesotrophic, therefore thick carbonate sediment deposited. Afterwards, as a consequence of the Neolithic human occupations, the natural development of the lake changed drastically and the lake choked up. The pollen and quartermalacological analysis of the area support the mentioned geological processes.

  15. L-Band Radiometer Experiment in the SMOS Test Site Upper Danube

    NASA Astrophysics Data System (ADS)

    Schlenz, Florian; Gebhardt, Timo; Loew, Alexander; Marzahn, Philip; Mauser, Wolfram

    2010-12-01

    In the frame of calibration and validation activities for ESA's soil moisture and ocean salinity mission, SMOS, the University of Munich operates a ground based L-band radiometer (ELBARA II) at 1.4 GHz to test and validate the radiative transfer model L-MEB also used in the SMOS Level 2 processor. The radiometer is situated on a test site near Puch, about 30 km west of Munich in the Upper Danube watershed in southern Germany in a temperate agricultural area. It is mounted on a scaffolding that allows to rotate the antenna which enables it to look at 2 different fields with grass and winter rape as land use respectively. In addition to the radiometer, a variety of complementary sensors are installed measuring all important meteorological and hydrological parameters. First datasets of the radiometer experiment are presented.

  16. First radiocarbon dated paleoecological data from the freshwater carbonates of the Danube-Tisza Interfluve

    NASA Astrophysics Data System (ADS)

    Sümegi, Pál; Molnár, Dávid; Sávai, Szilvia; Náfrádi, Katalin; Novák, Zsolt; Szelepcsényi, Zoltán; Törőcsik, Tünde

    2015-01-01

    The first radiocarbon dates available on the evolution of the freshwater carbonates of the Danube-Tisza Interfluve are presented in this work along with their possible uses to precisely date paleoecological and paleoenvironmental changes. This work also gives the basis of a comparative analysis of the Holocene radiocarbon-dated profile of Csólyospálos with other Hungarian radiocarbondated profiles of the same age (Bátorliget, the Sárrét, etc.) and the implementation of a detailed chronological and regional paleoenvironmental study. Furthermore, our findings clearly demonstrate the importance of radiocarbon analysis in the study of terminal Pleistocene and Holocene Hungarian sedimentary sequences for accurately dating and reconstructing the chronological order of paleoenvironmental changes as well as the evolution of the natural endowments plus the regional comparison of the various profiles.

  17. Bigger Is Better: Characteristics of Round Gobies Forming an Invasion Front in the Danube River

    PubMed Central

    Brandner, Joerg; Cerwenka, Alexander F.; Schliewen, Ulrich K.; Geist, Juergen

    2013-01-01

    Few studies have systematically investigated differences in performance, morphology and parasitic load of invaders at different stages of an invasion. This study analyzed phenotype-environment correlations in a fish invasion from initial absence until establishment in the headwater reach of the second largest European river, the Danube. Here, the round goby (Neogobius melanostomus) formed 73% of the fish abundance and 58% of the fish biomass in rip-rap bank habitats after establishment. The time from invasion until establishment was only about two years, indicating rapid expansion. Founder populations from the invasion front were different from longer established round goby populations in demography, morphology, feeding behaviour, sex ratio and parasitic load, indicating that plasticity in these traits determines invasion success. Competitive ability was mostly dependent on growth/size-related traits rather than on fecundity. As revealed by stable isotope analyses, specimens at the invasion front had a higher trophic position in the food web and seem to benefit from lower food competition. Somatic performance seems to be more important than investment in reproduction during the early stages of the invasion process and upstream-directed range expansion is not caused by out-migrating weak or juvenile individuals that were forced to leave high density areas due to high competition. This mechanism might be true for downstream introductions via drift. Greater abundance and densities of acanthocephalan endoparasites were observed at the invasion front, which contradicts the expectation that invasion success is determined by lower parasitic pressure in newly invaded areas. Overall, the pronounced changes in fish and invertebrate communities with a dominance of alien species suggest invasional meltdown and a shift of the upper Danube River towards a novel ecosystem with species that have greater resistance to goby predation. This seems to contribute to overcoming

  18. Antibiotic Resistance Patterns of Pseudomonas spp. Isolated from the River Danube

    PubMed Central

    Kittinger, Clemens; Lipp, Michaela; Baumert, Rita; Folli, Bettina; Koraimann, Günther; Toplitsch, Daniela; Liebmann, Astrid; Grisold, Andrea J.; Farnleitner, Andreas H.; Kirschner, Alexander; Zarfel, Gernot

    2016-01-01

    Spread and persistence of antibiotic resistance pose a severe threat to human health, yet there is still lack of knowledge about reservoirs of antibiotic resistant bacteria in the environment. We took the opportunity of the Joint Danube Survey 3 (JDS3), the world's biggest river research expedition of its kind in 2013, to analyse samples originating from different sampling points along the whole length of the river. Due to its high clinical relevance, we concentrated on the characterization of Pseudomonas spp. and evaluated the resistance profiles of Pseudomonas spp. which were isolated from eight sampling points. In total, 520 Pseudomonas isolates were found, 344 (66.0%) isolates were identified as Pseudomonas putida, and 141 (27.1%) as Pseudomonas fluorescens, all other Pseudomonas species were represented by less than five isolates, among those two P. aeruginosa isolates. Thirty seven percent (37%) of all isolated Pseudomonas species showed resistance to at least one out of 10 tested antibiotics. The most common resistance was against meropenem (30.4%/158 isolates) piperacillin/tazobactam (10.6%/55 isolates) and ceftazidime (4.2%/22 isolates). 16 isolates (3.1%/16 isolates) were multi-resistant. For each tested antibiotic at least one resistant isolate could be detected. Sampling points from the upper stretch of the River Danube showed more resistant isolates than downriver. Our results suggest that antibiotic resistance can be acquired by and persists even in Pseudomonas species that are normally not in direct contact with humans. A possible scenario is that these bacteria provide a reservoir of antibiotic resistance genes that can spread to related human pathogens by horizontal gene transfer. PMID:27199920

  19. Antibiotic Resistance Patterns of Pseudomonas spp. Isolated from the River Danube.

    PubMed

    Kittinger, Clemens; Lipp, Michaela; Baumert, Rita; Folli, Bettina; Koraimann, Günther; Toplitsch, Daniela; Liebmann, Astrid; Grisold, Andrea J; Farnleitner, Andreas H; Kirschner, Alexander; Zarfel, Gernot

    2016-01-01

    Spread and persistence of antibiotic resistance pose a severe threat to human health, yet there is still lack of knowledge about reservoirs of antibiotic resistant bacteria in the environment. We took the opportunity of the Joint Danube Survey 3 (JDS3), the world's biggest river research expedition of its kind in 2013, to analyse samples originating from different sampling points along the whole length of the river. Due to its high clinical relevance, we concentrated on the characterization of Pseudomonas spp. and evaluated the resistance profiles of Pseudomonas spp. which were isolated from eight sampling points. In total, 520 Pseudomonas isolates were found, 344 (66.0%) isolates were identified as Pseudomonas putida, and 141 (27.1%) as Pseudomonas fluorescens, all other Pseudomonas species were represented by less than five isolates, among those two P. aeruginosa isolates. Thirty seven percent (37%) of all isolated Pseudomonas species showed resistance to at least one out of 10 tested antibiotics. The most common resistance was against meropenem (30.4%/158 isolates) piperacillin/tazobactam (10.6%/55 isolates) and ceftazidime (4.2%/22 isolates). 16 isolates (3.1%/16 isolates) were multi-resistant. For each tested antibiotic at least one resistant isolate could be detected. Sampling points from the upper stretch of the River Danube showed more resistant isolates than downriver. Our results suggest that antibiotic resistance can be acquired by and persists even in Pseudomonas species that are normally not in direct contact with humans. A possible scenario is that these bacteria provide a reservoir of antibiotic resistance genes that can spread to related human pathogens by horizontal gene transfer.

  20. Bigger is better: characteristics of round gobies forming an invasion front in the Danube river.

    PubMed

    Brandner, Joerg; Cerwenka, Alexander F; Schliewen, Ulrich K; Geist, Juergen

    2013-01-01

    Few studies have systematically investigated differences in performance, morphology and parasitic load of invaders at different stages of an invasion. This study analyzed phenotype-environment correlations in a fish invasion from initial absence until establishment in the headwater reach of the second largest European river, the Danube. Here, the round goby (Neogobius melanostomus) formed 73% of the fish abundance and 58% of the fish biomass in rip-rap bank habitats after establishment. The time from invasion until establishment was only about two years, indicating rapid expansion. Founder populations from the invasion front were different from longer established round goby populations in demography, morphology, feeding behaviour, sex ratio and parasitic load, indicating that plasticity in these traits determines invasion success. Competitive ability was mostly dependent on growth/size-related traits rather than on fecundity. As revealed by stable isotope analyses, specimens at the invasion front had a higher trophic position in the food web and seem to benefit from lower food competition. Somatic performance seems to be more important than investment in reproduction during the early stages of the invasion process and upstream-directed range expansion is not caused by out-migrating weak or juvenile individuals that were forced to leave high density areas due to high competition. This mechanism might be true for downstream introductions via drift. Greater abundance and densities of acanthocephalan endoparasites were observed at the invasion front, which contradicts the expectation that invasion success is determined by lower parasitic pressure in newly invaded areas. Overall, the pronounced changes in fish and invertebrate communities with a dominance of alien species suggest invasional meltdown and a shift of the upper Danube River towards a novel ecosystem with species that have greater resistance to goby predation. This seems to contribute to overcoming

  1. Palaeoenvironment and fluvial history of river Danube between the Neolithic settlement sites of Vinca and Starcevo, Serbia

    NASA Astrophysics Data System (ADS)

    Penezic, Kristina; Kadereit, Annette; Thiemeyer, Heinrich

    2013-04-01

    The Neolithic site of Vinca - Belo brdo (ca. 5600 - 4200 BC) is located on the right bank of the Danube River, some 14 km downstream of the city of Belgrade in Serbia. The significance of the Vinca settlement is in its long occupational history, which produced more than 9 meters of settlement layers that provided archaeologists with an understanding of the chronological sequencing and development from the Middle to Late Neolithic in central Serbia. Vinca - Belo brdo was designated as the locus typicus for the Vinca Culture and is considered by many archaeologists as one of the most important sites of the European Neolithic. On the opposite, left side of the river Danube, the early Neolithic site of Starcevo is situated. It spans through the early Neolithic period dated to the seventh and the sixth millennium BC and it is the locus typicus for the Starcevo culture that on the territory of modern-day Serbia precedes the Vinca culture. The vicinity of the Danube influenced the development of these settlements and the relationship between them. Serving as a landmark, border, source of food, but also endangering the sites by a shifting stream course, the Danube is essential. Therefore it is important to define the position of the river during the occupational span of the Neolithic settlements and later. In our study, the early to mid-Holocene environmental changes of the fluvial landscape between the two Neolithic settlement sites are explored. We present preliminary results of recent geomorphological, sedimentological and archaeological investigations, as well as OSL dating, which were combined with relevant information from historical maps and satellite imagery in order to reconstruct the fluvial palaeolandscape.

  2. Evaluation of melioration area damage on the river Danube caused by the hydroelectric power plant 'Djerdap 1' backwater.

    PubMed

    Pajic, P; Andjelic, L; Urosevic, U; Polomcic, D

    2014-01-01

    Construction of the hydroelectric power plant (HPP) 'Djerdap 1' formed a backwater effect on the Danube and its tributaries, which had an inevitable influence on groundwater level, causing it to rise and thus creating additional threats to all melioration areas on more than 300 km of the Danube riversides, as well as on the riversides of its tributaries: the Sava (100 km) and the Tisa (60 km). In this paper, the HPP 'Djerdap 1' backwater effect on some characteristic melioration areas (34 in all) has been analyzed. In most of these areas intensive agricultural activity has always been present. An assessment of agricultural production damage was carried out by complex hydrodynamic calculations (60 calculation profiles) for different backwater regimes, with the aim to precisely quantify the HPP 'Djerdap 1' backwater effect on groundwater piezometric levels. Combining them with complex agroeconomic analyses, the aim is to quantify agricultural production damage and to consider the perspective of melioration area users. This method, which combines two different, but compatible, aspects of the melioration area threat assessment (hydrodynamic and agroeconomic), may present a quality base for further agricultural production threat assessment on all melioration areas on the Danube riversides, with the final aim to consider the economic effects and the importance of its further protection. PMID:25051487

  3. Large-scale hydrological simulations using the soil water assessment tool, protocol development, and application in the danube basin.

    PubMed

    Pagliero, Liliana; Bouraoui, Fayçal; Willems, Patrick; Diels, Jan

    2014-01-01

    The Water Framework Directive of the European Union requires member states to achieve good ecological status of all water bodies. A harmonized pan-European assessment of water resources availability and quality, as affected by various management options, is necessary for a successful implementation of European environmental legislation. In this context, we developed a methodology to predict surface water flow at the pan-European scale using available datasets. Among the hydrological models available, the Soil Water Assessment Tool was selected because its characteristics make it suitable for large-scale applications with limited data requirements. This paper presents the results for the Danube pilot basin. The Danube Basin is one of the largest European watersheds, covering approximately 803,000 km and portions of 14 countries. The modeling data used included land use and management information, a detailed soil parameters map, and high-resolution climate data. The Danube Basin was divided into 4663 subwatersheds of an average size of 179 km. A modeling protocol is proposed to cope with the problems of hydrological regionalization from gauged to ungauged watersheds and overparameterization and identifiability, which are usually present during calibration. The protocol involves a cluster analysis for the determination of hydrological regions and multiobjective calibration using a combination of manual and automated calibration. The proposed protocol was successfully implemented, with the modeled discharges capturing well the overall hydrological behavior of the basin.

  4. 21-st century precipitation estimation in the Danube middle and lower basin by EVT modelling

    NASA Astrophysics Data System (ADS)

    Mares, C.; Mares, I.; Mihailescu, M.; Stanciu, A.

    2010-09-01

    The simulated precipitation for the 20-th and 21-st centuries at 10 stations from the Danube middle and lower basin are analysed together with the daily pressure values at sea level from March, April, May for 42 years obtained from the four GCMs (CNRM, ECHAM5-MPI, EGMAM and IPSL). For the 20-th century the period 1958-1999 was considered and for the 21-st century 2 periods of 42 years were selected: 2009-2050 and 2051-2092 from the A1B scenario. In the pressure field, the predictors from three key zones were selected as being significant for the precipitation behavior from the Danube middle and lower basin. A nonhomogeneus hidden Markov model (NHMM) with 7 states was applied for the precipitation from 10 stations, for observations and also for each of the considered scenarios, with 3 predictors defined in the key points. The precipitation values were corrected by bias and the predictors were the same for all models, calculated from pressure values corrected by bias. After the modelling of the daily precipitation through a NHMM, a simulation was done on 100 achievements each one with 42 years and 90 days each year. In this way, the daily maximum precipitation amounts during spring from 4200 years were selected. This simulation was necessary in order to increase the statistical selection volume necessary within the modelling through distribution of the extreme values. From these precipitation simulated with NHMM for 4200 years, the maximum daily amounts during spring were selected and then modelled with a generalized distribution of the extreme values (GEV). For the modelling by generalized Pareto distribution (GPD) the daily precipitation values which exceed a certain threshold were selected. After testing several thresholds values, it was concluded that the most adequate is the 50 mm threshold for each of the 10 considered stations. Also it was made an average of the precipitation on the 10 considered stations and from the analysis of the different thresholds it

  5. Morphometric analyze for flood hazard map using DTM built with LIDAR and Echo-sounder data in Danube Delta

    NASA Astrophysics Data System (ADS)

    Constantinescu, A.; Nichersu, I.; Trifanov, C.; Nichersu, I.; Mierla, M.

    2012-04-01

    High definition morphometric data acquired with a multibeam sonar is used to develop studies of past and future riverbed and shores dynamics on the Lower Danube at two bifurcations, one upstream from Tulcea city (Ceatal Ismail) and one downstream from Tulcea City (Ceatal Sf. Gheorghe). These studies help in understanding the tendency of the evolution of the Danube Delta in terms of river morphology, discharges, sediments and navigation between the three main branches which are: Chilia with an average flow of 60%, Sulina with an average flow of 18% and Sf. Gheorghe with an average flow of 22%. The most significant issue is the erosion of the shores of Pătlăgeanca town which represents the 1st bifurcation (Ceatal Izmail). Another intriguing issue is the presence of a current diversion dike located at the first bifurcation, the studies and models will show its importance and impact on the river morphology and biodiversity. Historical maps are used to determine the initial state of the area and will allow analyses of various types. Back in 2010 there was a high flooding in this area and 6 km downstream on Chilia branch the water broke the right side (Romanian side) dyke where used to be an old channel and flooded a 4570 Ha agricultural polder called Sireasa. It is imperative to know if the route of that flooding can shape the 4th branch of the Danube Delta. The dykes that are protecting the villages and the agricultural polders in this area are over raised but they are still in danger because they can still be flooded through infiltrations or from behind the dyke through upstream flooded polders. The situation in which the current diversion dyke is modified by increasing its length towards the downstream (act already happened), the shores from downstream and of Pătlăgeanca village will utterly alterate the river morphology, discharges, quantity of sediments and navigation in the whole Danube Delta. The resulted high definition data aquired with a multibeam sonar

  6. The influence of shelfbreak forcing on the alongshelf penetration of the Danube buoyant water, Black sea

    NASA Astrophysics Data System (ADS)

    Yankovsky, Alexander E.; Lemeshko, Evgeny M.; Ilyin, Yuriy P.

    2004-06-01

    The buoyancy-driven coastal current propagating along the western coast in the Black Sea is forced by the discharge of several major European rivers including the Danube, Dnepr and South Bug. In this study, we present observational evidence that the buoyant water alongshelf penetration is strongly affected by shelfbreak mesoscale features associated with the Rim Current dynamics. The Rim Current is a major element of the Black Sea general circulation, typically following isobaths over the upper-to-middle slope. Two hydrographic surveys conducted in 1992 and 1994 have been chosen among available archive data for the detailed analysis. In both years, though Danube buoyant discharge was similar prior to the beginning of shipboard observations (varying around 7000 m 3 s -1), the buoyant water exhibited very different downstream (that is, in the direction of Kelvin wave) penetration. In 1992, it spread all the way around the southwestern corner of the Black Sea basin and then further eastward past the Bosporus Strait. In contrast, its downstream penetration was blocked in 1994 and buoyant water did not even reach Cape Kaliakra on the Bulgarian coast. This difference was related to the shelfbreak processes. In 1992, the cyclonic meander of the Rim Current merged with the coastal buoyant water thus promoting its advection from Cape Kaliakra downstream. In 1994, a strong anticyclone in the southwestern corner of the Black Sea completely blocked the propagation of a buoyancy-driven current past Cape Kaliakra. In addition, another anticyclone in the northwestern part of the sea advected buoyant water offshore to the central area of the northwestern shelf. The positions of anticyclonic eddies during a period of observations was confirmed by remote sensing data. As these and other examples indicate, coastal buoyancy driven currents can be effectively blocked and dispersed offshore by the shelfbreak anticyclones if the shelf width allows their interaction with buoyant water

  7. Impacts of climate change on ecologically relevant river flow characteristics in the Danube river catchment

    NASA Astrophysics Data System (ADS)

    Stagl, Judith; Hattermann, Fred F.

    2014-05-01

    River flow characteristics reflecting flow seasonality and variability such as low and high flow durations play an important role for aquatic, wetland and riparian ecosystems. Climate change might not only alter long term average flows, but also affect the hydrologic regime on smaller scales. The Indicators of Hydrological Alteration (IHA) statistics (Richter et al. 1996) characterize changes in hydrologic regime by using a suite of ecologically relevant indicators given a daily discharge time series. Eco-hydrological indicators are applied to bridge the communication gap that exists between professionals in the fields of hydrology and ecology. Such indicators can help to synthesize complex hydrological variables into ecologically-meaningful information. For this study the eco-hydrological watershed model SWIM was applied for the whole Danube river catchment using 1224 subbasins. The SWIM model (Soil and Water Integrated Model) is a continuous-time semi-distributed watershed model, which combines hydrological processes, vegetation, erosion and nutrient dynamics at the meso- to macroscale (Krysanova et al. 1998, 2000). As the Danube river basin is climatically heterogeneous, it is characterized by a changing-complex river runoff regime varying from nival regimes in the alpine parts to mainly rain feed regimes in the lowlands. To account for these different river regimes of the Danubian tributaries, the SWIM model was calibrated separately for the major river subbasins. After calibration and validation of the model, this study uses a set of 14 high-resolution climate change projections performed by several state-of-art GCMs and RCMs, all based on the IPCC-SRES-A1B emission scenario, from the ENSEMBLES project (EU FP6). They serve as meteorological drivers for the SWIM model to simulate future daily time series of river discharge under different scenario conditions. The derived hydrologic data series then were statistically analyzed by using selected eco

  8. " Using the impact model in order to predict the Danube river flow in the last quarter of the XXI century

    NASA Astrophysics Data System (ADS)

    Adamovic, M.

    2009-04-01

    The paper has intercompared and verified Regional Climate Model (RCM) EBU-POM in its representation of the hydrological balance over the Danube river basin along Iron Gate gorge, for the time frame 1961-1990 and 2071-2100 according to the IPCC SRES scenario A1B. The Danube has been chosen as a case study because of its multiple relevance for socioeconomical, as well as environmental and climatic level. This part of the Danube river basin has a direct relevance to the Mediterranean region, since it provides a relevant input of freshwater to the sea, as well as being fuelled mostly by precipitations due to the water of Mediterranean origin. On the other, the Dinaric-Balkan mountain chains in the west and the Carpathian mountain bow in the north and east, present distinctive morphological and climatic regions and barriers. Having been aware of the climatic-hydrologic and hydrographic homogeneity of regions, the whole territory of Serbia is divided into 20 units basins. The part of Danube basin in its eastern part present one of them, and was subject of the research. For this balance unit, the main components of the balance equation of the water that included into the calculation are: precipitation P (mm), flow Q (m3/s), runoff depth h (mm), evaporation E (mm) and annual air temperature T (0C). The hydrological balance has been computed in two different, but in principle equivalent ways. The first approach, which has a more hydrological nuance, relies on establishing relationships between annual averages of the hydrological balance parameters (E, P, T) in order to get relevant coefficients. The second approach, which is more typically meteorological, relies on the calculation of the E for the time frame 2071-2100 by using the previous coefficients. On the basis of the assessment of climate parameters in the XXI century and with help of the established relationships, the water flow of Danube river and runoff depth were defined for this century. The outcomes are very

  9. Migration and habitats of diadromous Danube River sturgeons in Romania: 1998-2000

    USGS Publications Warehouse

    Kynard, B.; Suciu, R.; Horgan, M.

    2002-01-01

    Upstream migrant adults of stellate sturgeon, Acipenser stellatus (10 in 1998, 43 in 1999) and Russian sturgeon, A. gueldenstaedtii (three in 1999) were captured at river km (rkm) 58-137, mostly in the spring, and tagged with acoustic tags offering a reward for return. The overharvest was revealed by tag returns (38% in 1998, 28% in 1999) and by harvest within 26 days (and before reaching spawning grounds) of the six stellate sturgeon tracked upstream. A drop-back of > 50% of the tagged sturgeon, some to the Black Sea, shows a high sensitivity to interruption of migration and capture/handling/holding. Harvesting and dropback prevented tracking of sturgeon to spawning sites. Gillnetting and tracking of stellate sturgeon showed that the autumn migration ended in early October (river temperature 16??C) and identified a likely wintering area at river km (rkm) 75-76 (St George Branch). Thus, fishery harvesting after early October captures wintering fish, not migrants. Rare shoreline cliffs in the lower river likely create the only rocky habitat for sturgeon spawning. A survey for potential spawning habitats found five sites with rocky substrate and moderate water velocity, all ???rkm 258. Drift netting caught early life-stages of 17 fish species and one sturgeon, a beluga, Huso huso, larva likely spawned at ???rkm 258. All diadromous Danube sturgeons likely spawn at ???rkm 258.

  10. Typology of historical sources and the reconstruction of long-term historical changes of riverine fish: a case study of the Austrian Danube and northern Russian rivers.

    PubMed

    Haidvogl, Gertrud; Lajus, Dmitry; Pont, Didier; Schmid, Martin; Jungwirth, Mathias; Lajus, Julia

    2014-10-01

    Historical data are widely used in river ecology to define reference conditions or to investigate the evolution of aquatic systems. Most studies rely on printed documents from the 19th century, thus missing pre-industrial states and human impacts. This article discusses historical sources that can be used to reconstruct the development of riverine fish communities from the Late Middle Ages until the mid-20th century. Based on the studies of the Austrian Danube and northern Russian rivers, we propose a classification scheme of printed and archival sources and describe their fish ecological contents. Five types of sources were identified using the origin of sources as the first criterion: (i) early scientific surveys, (ii) fishery sources, (iii) fish trading sources, (iv) fish consumption sources and (v) cultural representations of fish. Except for early scientific surveys, all these sources were produced within economic and administrative contexts. They did not aim to report about historical fish communities, but do contain information about commercial fish and their exploitation. All historical data need further analysis for a fish ecological interpretation. Three case studies from the investigated Austrian and Russian rivers demonstrate the use of different source types and underline the necessity for a combination of different sources and a methodology combining different disciplinary approaches. Using a large variety of historical sources to reconstruct the development of past fish ecological conditions can support future river management by going beyond the usual approach of static historical reference conditions.

  11. Typology of historical sources and the reconstruction of long-term historical changes of riverine fish: a case study of the Austrian Danube and northern Russian rivers.

    PubMed

    Haidvogl, Gertrud; Lajus, Dmitry; Pont, Didier; Schmid, Martin; Jungwirth, Mathias; Lajus, Julia

    2014-10-01

    Historical data are widely used in river ecology to define reference conditions or to investigate the evolution of aquatic systems. Most studies rely on printed documents from the 19th century, thus missing pre-industrial states and human impacts. This article discusses historical sources that can be used to reconstruct the development of riverine fish communities from the Late Middle Ages until the mid-20th century. Based on the studies of the Austrian Danube and northern Russian rivers, we propose a classification scheme of printed and archival sources and describe their fish ecological contents. Five types of sources were identified using the origin of sources as the first criterion: (i) early scientific surveys, (ii) fishery sources, (iii) fish trading sources, (iv) fish consumption sources and (v) cultural representations of fish. Except for early scientific surveys, all these sources were produced within economic and administrative contexts. They did not aim to report about historical fish communities, but do contain information about commercial fish and their exploitation. All historical data need further analysis for a fish ecological interpretation. Three case studies from the investigated Austrian and Russian rivers demonstrate the use of different source types and underline the necessity for a combination of different sources and a methodology combining different disciplinary approaches. Using a large variety of historical sources to reconstruct the development of past fish ecological conditions can support future river management by going beyond the usual approach of static historical reference conditions. PMID:25284959

  12. Typology of historical sources and the reconstruction of long-term historical changes of riverine fish: a case study of the Austrian Danube and northern Russian rivers

    PubMed Central

    Haidvogl, Gertrud; Lajus, Dmitry; Pont, Didier; Schmid, Martin; Jungwirth, Mathias; Lajus, Julia

    2014-01-01

    Historical data are widely used in river ecology to define reference conditions or to investigate the evolution of aquatic systems. Most studies rely on printed documents from the 19th century, thus missing pre-industrial states and human impacts. This article discusses historical sources that can be used to reconstruct the development of riverine fish communities from the Late Middle Ages until the mid-20th century. Based on the studies of the Austrian Danube and northern Russian rivers, we propose a classification scheme of printed and archival sources and describe their fish ecological contents. Five types of sources were identified using the origin of sources as the first criterion: (i) early scientific surveys, (ii) fishery sources, (iii) fish trading sources, (iv) fish consumption sources and (v) cultural representations of fish. Except for early scientific surveys, all these sources were produced within economic and administrative contexts. They did not aim to report about historical fish communities, but do contain information about commercial fish and their exploitation. All historical data need further analysis for a fish ecological interpretation. Three case studies from the investigated Austrian and Russian rivers demonstrate the use of different source types and underline the necessity for a combination of different sources and a methodology combining different disciplinary approaches. Using a large variety of historical sources to reconstruct the development of past fish ecological conditions can support future river management by going beyond the usual approach of static historical reference conditions. PMID:25284959

  13. Middle Mississippi River decision support system: user's manual

    USGS Publications Warehouse

    Rohweder, Jason J.; Zigler, Steven J.; Fox, Timothy J.; Hulse, Steven N.

    2005-01-01

    This user's manual describes the Middle Mississippi River Decision Support System (MMRDSS) and gives detailed examples on its use. The MMRDSS provides a framework to assist decision makers regarding natural resource issues in the Middle Mississippi River floodplain. The MMRDSS is designed to provide users with a spatially explicit tool for tasks, such as inventorying existing knowledge, developing models to investigate the potential effects of management decisions, generating hypotheses to advance scientific understanding, and developing scientifically defensible studies and monitoring. The MMRDSS also includes advanced tools to assist users in evaluating differences in complexity, connectivity, and structure of aquatic habitats among river reaches. The Environmental Systems Research Institute ArcView 3.x platform was used to create and package the data and tools of the MMRDSS.

  14. Body burden of pesticides and wastewater-derived pollutants on freshwater invertebrates: Method development and application in the Danube River.

    PubMed

    Inostroza, Pedro A; Wicht, Anna-Jorina; Huber, Thomas; Nagy, Claudia; Brack, Werner; Krauss, Martin

    2016-07-01

    While environmental risk assessment is typically based on toxicant concentrations in water and/or sediment, awareness is increasing that internal concentrations or body burdens are the key to understand adverse effects in organisms. In order to link environmental micropollutants as causes of observed effects, there is an increasing demand for methods to analyse these chemicals in organisms. Here, a multi-target screening method based on pulverised liquid extraction (PuLE) and a modified QuEChERS approach with an additional hexane phase was developed. It is capable to extract and quantify organic micropollutants of diverse chemical classes in freshwater invertebrates. The method was tested on gammarids from the Danube River (within the Joint Danube Survey 3) and target compounds were analysed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Furthermore, a non-target screening using high resolution-tandem mass spectrometry (LC-HRMS/MS) was conducted. A total of 17 pollutants were detected and/or quantified in gammarids at low concentrations. Pesticide concentrations ranged from 0.1 to 6.52 ng g(-1) (wet weight), those of wastewater-derived pollutants from 0.1 to 2.83 ng g(-1) (wet weight). The presence of wastewater-derived pollutants was prominent at all spots sampled. Using non-target screening, we could successfully identify several chlorinated compounds. These results demonstrate for the first time the presence of pesticides and wastewater-derived pollutants in invertebrates of the Danube River. PMID:27064613

  15. Body burden of pesticides and wastewater-derived pollutants on freshwater invertebrates: Method development and application in the Danube River.

    PubMed

    Inostroza, Pedro A; Wicht, Anna-Jorina; Huber, Thomas; Nagy, Claudia; Brack, Werner; Krauss, Martin

    2016-07-01

    While environmental risk assessment is typically based on toxicant concentrations in water and/or sediment, awareness is increasing that internal concentrations or body burdens are the key to understand adverse effects in organisms. In order to link environmental micropollutants as causes of observed effects, there is an increasing demand for methods to analyse these chemicals in organisms. Here, a multi-target screening method based on pulverised liquid extraction (PuLE) and a modified QuEChERS approach with an additional hexane phase was developed. It is capable to extract and quantify organic micropollutants of diverse chemical classes in freshwater invertebrates. The method was tested on gammarids from the Danube River (within the Joint Danube Survey 3) and target compounds were analysed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Furthermore, a non-target screening using high resolution-tandem mass spectrometry (LC-HRMS/MS) was conducted. A total of 17 pollutants were detected and/or quantified in gammarids at low concentrations. Pesticide concentrations ranged from 0.1 to 6.52 ng g(-1) (wet weight), those of wastewater-derived pollutants from 0.1 to 2.83 ng g(-1) (wet weight). The presence of wastewater-derived pollutants was prominent at all spots sampled. Using non-target screening, we could successfully identify several chlorinated compounds. These results demonstrate for the first time the presence of pesticides and wastewater-derived pollutants in invertebrates of the Danube River.

  16. Dating of coastal marine sediments: 210Pb versus 137Cs signal on the Danube-influenced Black Sea shelf

    NASA Astrophysics Data System (ADS)

    Friedrich, Jana; Laptev, Gennady

    2010-05-01

    Coastal marine sediments represent a natural archive of pelagic processes, coastal erosion and river discharge of suspended matter. Correct dating of those sediments is a prerequisite for chronological reconstruction of the flux of pollutants and organic matter from the water column to the sediments and hence, the reconstruction of the pollution and eutrophication events. In the reconstruction of the sedimentation history during the pre-industrial and industrial periods, which usually spans the past 100 years, the natural occurring radionuclide 210Pb and the artificial radionuclides 137Cs and 241Am are widely applied tracers. 137Cs is used as an independent time marker for end the atmospheric bomb test fallout in 1963 and the Chernobyl accident in 1986. As the 137Cs signal is often weakened due to its mobility in sediments, 241Am, less mobile than 137Cs and derived from decay the bomb fallout of 241Pu, is used as a second time marker of the 1963 event. The northwestern shelf of the Black Sea has been seriously affected by eutrophication and pollution from the late 1960's to the mid-1990's, largely triggered by Danube River input of nutrients and pollutants. The aim of our study is ultimately to reconstruct the eutrophication history and recycling of nutrients following the deposition of organic matter. The ‘memory effect' of sediment recycling plays a critical role in maintaining eutrophic conditions in enclosed seas such as the Black Sea. Here we present results from sediment cores taken within the Danube River plume on the shallow northwestern shelf of the Black Sea. The cores have been dated in two laboratories to rule out artifacts. The sediment record is repeatedly interrupted by so-called turbidites that consist of stiff clay. The clay horizons display a drop in unsupported 210Pb and 137Cs and a higher signal of supported 210Pb than the non-clay horizons. Below the turbidite, the unsupported 210Pb and 137Cs increase again to values above the turbidite. This

  17. Regional analysis of changes in snow pack in mountainous basins in the central Danube region

    NASA Astrophysics Data System (ADS)

    Balint, Gabor; Juričeková, Katarina; Gauzer, Balazs; Hlavčová, Kamila; Kohnová, Silvia; Szolgay, Jan; Zsideková, Beata

    2013-04-01

    Accurate estimation of the volume of water stored in the snow pack and its rate of release is essential to predict the flow during the snowmelt period. In mountainous drainage basins water stored in the snow pack represents an important component of the water budget. Two modelling tools are compared. The first, HOLV snowmelt model is developed by the Hungarian National Hydrological Forecasting Service (VITUKI NHFS) for regional assessment of snow accumulation and ablation of the central Danube. The model originates from the early 80's and it is under continuous development, while its recent distributed version over a grid with 0.1 degree resolution is in use. The snowmelt model has a flexible structure; it is able to change its own structure in function of data availability. In case when only precipitation and air temperature data are available temperature index method is used. When also other data are accessible (cloudiness, dew point, wind speed) using of energy balance model is to be preferred. If there are suitable data available for calculation of the energy terms, the energy balance method can be applied. The second semi-distributed Hron model, developed at the Slovak University of Technology was applied to a smaller sub-basin to represent spatial distribution of snow cover by simulated snow water equivalent. The upper Hron river basin with an area of 1766 km2 is located in central Slovakia. The conceptual semi-distributed tool applied contains three basic storage components with 15 calibrated parameters, as the flow routing component the cascade of linear reservoirs is used as opposed to the original simple triangular routing function. The snow sub-model uses the temperature index (degree-day) method for snow accumulation and snowmelt calculations. Uncertainty of model parameters was reduced by multi-calibration on the mean daily discharges in the basin outlet and measured stations data of snow water equivalent. Changes in the model parameters during the

  18. L-band radiometer experiment in the SMOS test site Upper Danube

    NASA Astrophysics Data System (ADS)

    Schlenz, Florian; Gebhardt, Timo; Loew, Alexander; Marzahn, Philip; Mauser, Wolfram

    2010-05-01

    In the frame of calibration and validation activities for ESA's soil moisture and ocean salinity mission, SMOS, the University of Munich operates a ground based L-band radiometer (ELBARA II) on an experimental farm in Southern Germany since September 2009. It is being used to validate the radiative transfer model, L-MEB, used in the SMOS Level 2 processor. The radiometer measures the natural emission of two fields in the microwave domain with a wavelength of 1.4 GHz. Its working principle is similar to that of SMOS, for which reason it can be used for validation of the radiative transfer model on the field scale. To support the validation, extensive environmental measurements are being made at the test site. The radiometer is situated on an experimental farm near Puch, about 30 km west of Munich in the Upper Danube watershed in southern Germany in a temperate agricultural area. It is mounted on a 4 m high scaffolding that allows to turn the radiometer to look at 2 different fields with grass and winter rape as land use respectively. In addition to the L-band measurements, thermal infrared (IR) measurements are performed. For this purpose, one thermal IR radiometer is attached to the ELBARA antenna to look into the same direction and two IR radiometers are constantly pointed at the two fields. Next to the radiometer is a meteorological station providing soil and air temperature profiles, precipitation, global radiation, wind speed and relative humidity measurements with an hourly resolution. In addition to that, soil moisture is measured with TDR probes in 2 profiles under each of the two fields with several probes installed at depths between 5 and 50cm. Vegetation and snow parameters are also recorded on a regularly basis. Soil roughness is measured with a photogrammetric approach. An overview about the infrastructure and existing datasets is presented.

  19. Extreme value analysis in the Danube lower basin discharge time series in the twentieth century

    NASA Astrophysics Data System (ADS)

    Mares, C.; Mares, Ileana; Stanciu, Antoaneta

    2009-03-01

    The daily discharge time series in the lower Danube basin (Orsova) have been considered for the 1900-2005 period. The extreme value theory (EVT) is applied for the study of daily discharges incorporating some covariates. Two methods are applied for fitting the data to an extreme value distribution: block maxima and peaks over thresholds (POT). Using the block maxima approach associated with the use of the generalised extreme value (GEV) distribution, monthly and seasonal maxima of daily discharge for 1900-2005 have been analysed. Separately the monthly maxima of daily discharge for the 1958-2001 was analysed in order to be compatible with atmospheric circulation available from ERA-40. For performing parameter estimation, the maximum likelihood estimation (MLE) method was used. From the three possible types of GEV distribution, a Weibull distribution fits both the monthly and seasonal maxima of the daily discharges very well. The North Atlantic Oscillation (NAO) and the first ten principal components (PC) of the decomposition in multi-variate empirical orthogonal functions (MEOF) of three atmospheric fields (sea level pressure, 500 hPa and 500-1000 hPa thickness) over the Atlantic-European region (ERA-40), have been introduced as covariates. An improvement over the model without the covariate is found by incorporating NAO as the covariate in location parameter, especially for the spring maxima having the NAO as predictor during the winter. Related to atmospheric circulation influence, the most significant results are obtained by incorporating the first 10 PCs of the MEOF in the location parameter of GEV distribution within a month before the month of the discharge level. Regarding the POT approach associated with generalised Pareto distribution (GPD), different thresholds have been tested for daily discharges in the period 1900-2005, where the maxima were fitted by a bounded (or beta) distribution.

  20. Hydraulic reconstruction of historical floods at the Danube-Carpathian basin

    NASA Astrophysics Data System (ADS)

    Salinas, José Luis; Kiss, Andrea

    2013-04-01

    Estimation of flood quantiles with high return periods (i.e. low exceedance probabilities) is a key step in designing hydraulic structure and developing flood protection strategies. These estimates are always linked with a high prediction uncertainty that increases with larger return periods. One way to reduce this uncertainty is by introducing additional information in the analysis beyond the instrumental peak annual flow time series (Merz and Blöschl 2008 ab). In this study, values from historical floods from the Danube-Carpathian basin during the last 500 years are reconstructed from detailed archive information about cross section geometry, flood plain extent and water level. The historical information was mainly found in official documents and registers. Including this information into the analysis allows to verify or deny the stationarity assumption on which most of the flood quantiles estimation methods are based. On a second step we are able to introduce information about the historical floods into the prediction with the help of a Bayesian framework (Viglione et al. 2013). If the stationarity assumption is sufficiently fulfilled, this temporal expansion of information will reduce dramatically the uncertainty bounds of the flood frequency curve and provide more accurate estimates for high return periods. Merz, R., and G. Blöschl (2008a), Flood frequency hydrology: 1. Temporal, spatial, and causal expansion of information, Water Resour. Res., 44, W08432, doi:10.1029/2007WR006744. Merz, R., and G. Blöschl (2008b), Flood frequency hydrology: 2. Combining data evidence, Water Resour. Res., 44, W08433, doi:10.1029/2007WR006745. Viglione, A., R. Merz, J. L. Salinas, and G. Blöschl (2012), Flood frequency hydrology: 3. A Bayesian analysis, Water Resour. Res., doi:10.1029/2011WR010782, in press.

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

    NASA Astrophysics Data System (ADS)

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

    2011-04-01

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

  2. Non-dioxin-like PCBs in ten different fish species from the Danube river in Serbia.

    PubMed

    Janković, Saša; Curčić, Marijana; Radičević, Tatjana; Stefanović, Srđan; Lenhardt, Mirjana; Durgo, Ksenija; Antonijević, Biljana

    2011-10-01

    This work has been developed to examine the level of non-dioxin-like (ndl) PCBs (28, 52, 101, 138, 153 and 180) in (a) ten different freshwater fish species from the Danube river, (b) two sampling points: up and downstream of the industrial zone of the city of Pancevo (ecological hot spot in Serbia) and (c) two time points i.e., in 2001 and 2006. Obtained results would serve to analyse spatial, temporal and congener profile characteristics of ndl PCBs cumulated in fish tissues due to environmental pollution. Sixty-four samples of the following species were collected: wels (Silirus glanus), pike (Esox lucius), bream (Abramis brama), crucian carp (Carassius carassius), pike pearch (Stizostedion lucioperca), barbel (Barbus barbus), tench (Tinca tinca), sterlet (Acipenser ruthenus L.), common carp (Cyprinus carpio) and bighead carp (Hypophthalmichthys nobilis). Gas chromatography coupled with electron capture detector was used for analysis of ndl PCBs. Total ndl PCBs content in upstream samples ranged from 2.7 to 98.1 ng/g and from 4.9 to 68.3 ng/g in 2001 and 2006, respectively. During the 5 years, ndl PCBs content increased significantly in downstream samples i.e., ndl PCBs varied from 13.7 to 46.1 ng/g and from 14.4 to 107.2 ng/g in 2001 and 2006, respectively. PCBs 138 and 180 were predominant congeners in 2001, while in 2006 the most abundant PCB congeners were 138 and 153. In 2006, the presence of PCB 28 and PCB 52 has indicated a recent contamination event. Data on continual monitoring of PCBs in all relevant environmental compartments together with appropriate biomonitoring data are expected to give comprehensive insight into the fate and behaviour profile of these contaminants. PMID:21161586

  3. Educating for action: Aligning skills with policies for sustainable development in the Danube river basin.

    PubMed

    Irvine, Kenneth; Weigelhofer, Gabriele; Popescu, Ioana; Pfeiffer, Ellen; Păun, Andrei; Drobot, Radu; Gettel, Gretchen; Staska, Bernadette; Stanica, Adrian; Hein, Thomas; Habersack, Helmut

    2016-02-01

    Sustainable river basin management depends on knowledge, skills and education. The DANCERS project set out to identify feasible options for achieving education for sustainable water management across the Danube river basin, and its integration with broader education and economic development. The study traced the historic, regulatory and educational landscape of water management in the basin, contrasting it with the complex political decision-making, data-heavy decision support, learning-centred collaboration, and information-based participation that are all inherent components of Integrated Water Resource Management (IWRM). While there is a wide range of educational opportunities and mobility schemes available to individuals, there is no coherent network related to training in water management and sustainable development in the study region. Progress in addressing the multi-layered environmental challenges within the basin requires further aligning of economic, environmental and educational policies, advancing the EU Bologna Process across the region, and the development of dedicated training programmes that combine technical and relational skills. The DANCERS project identified key short and medium term needs for education and research to support progressive adoption of sustainable development, and the necessary dialogue across the public and private sectors to align policies. These include the development of new education networks for masters and PhD programmes, including joint programmes; improved access to technical training and life-long learning programmes for skills development; developing formalized and certified competency structures and associated accreditation of institutions where such skilled individuals work; and developing a co-ordinated research infrastructure and pan-basin programme for research for water management and sustainable development.

  4. The Danube so colourful: a potpourri of plastic litter outnumbers fish larvae in Europe's second largest river.

    PubMed

    Lechner, Aaron; Keckeis, Hubert; Lumesberger-Loisl, Franz; Zens, Bernhard; Krusch, Reinhard; Tritthart, Michael; Glas, Martin; Schludermann, Elisabeth

    2014-05-01

    Previous studies on plastic pollution of aquatic ecosystems focused on the world's oceans. Large rivers as major pathways for land-based plastic litter, has received less attention so far. Here we report on plastic quantities in the Austrian Danube. A two year survey (2010, 2012) using stationary driftnets detected mean plastic abundance (n = 17,349; mean ± S.D: 316.8 ± 4664.6 items per 1000 m(-3)) and mass (4.8 ± 24.2 g per 1000 m(-3)) in the river to be higher than those of drifting larval fish (n = 24,049; 275.3 ± 745.0 individuals. 1000 m(-3) and 3.2 ± 8.6 g 1000 m(-3)). Industrial raw material (pellets, flakes and spherules) accounted for substantial parts (79.4%) of the plastic debris. The plastic input via the Danube into the Black Sea was estimated to 4.2 t per day.

  5. The Danube so colourful: a potpourri of plastic litter outnumbers fish larvae in Europe's second largest river.

    PubMed

    Lechner, Aaron; Keckeis, Hubert; Lumesberger-Loisl, Franz; Zens, Bernhard; Krusch, Reinhard; Tritthart, Michael; Glas, Martin; Schludermann, Elisabeth

    2014-05-01

    Previous studies on plastic pollution of aquatic ecosystems focused on the world's oceans. Large rivers as major pathways for land-based plastic litter, has received less attention so far. Here we report on plastic quantities in the Austrian Danube. A two year survey (2010, 2012) using stationary driftnets detected mean plastic abundance (n = 17,349; mean ± S.D: 316.8 ± 4664.6 items per 1000 m(-3)) and mass (4.8 ± 24.2 g per 1000 m(-3)) in the river to be higher than those of drifting larval fish (n = 24,049; 275.3 ± 745.0 individuals. 1000 m(-3) and 3.2 ± 8.6 g 1000 m(-3)). Industrial raw material (pellets, flakes and spherules) accounted for substantial parts (79.4%) of the plastic debris. The plastic input via the Danube into the Black Sea was estimated to 4.2 t per day. PMID:24602762

  6. Modeling the BOD of Danube River in Serbia using spatial, temporal, and input variables optimized artificial neural network models.

    PubMed

    Šiljić Tomić, Aleksandra N; Antanasijević, Davor Z; Ristić, Mirjana Đ; Perić-Grujić, Aleksandra A; Pocajt, Viktor V

    2016-05-01

    This paper describes the application of artificial neural network models for the prediction of biological oxygen demand (BOD) levels in the Danube River. Eighteen regularly monitored water quality parameters at 17 stations on the river stretch passing through Serbia were used as input variables. The optimization of the model was performed in three consecutive steps: firstly, the spatial influence of a monitoring station was examined; secondly, the monitoring period necessary to reach satisfactory performance was determined; and lastly, correlation analysis was applied to evaluate the relationship among water quality parameters. Root-mean-square error (RMSE) was used to evaluate model performance in the first two steps, whereas in the last step, multiple statistical indicators of performance were utilized. As a result, two optimized models were developed, a general regression neural network model (labeled GRNN-1) that covers the monitoring stations from the Danube inflow to the city of Novi Sad and a GRNN model (labeled GRNN-2) that covers the stations from the city of Novi Sad to the border with Romania. Both models demonstrated good agreement between the predicted and actually observed BOD values.

  7. Testing for viral material in water of public bathing areas of the Danube during summer, Vojvodina, Serbia, 2014.

    PubMed

    Jovanović Galović, Aleksandra; Bijelović, Sanja; Milošević, Vesna; Hrnjaković Cvjetkovic, Ivana; Popović, Milka; Kovačević, Gordana; Radovanov, Jelena; Dragić, Nataša; Petrović, Vladimir

    2016-04-14

    From August to September 2014 a water quality study was conducted on five popular public Danube beaches in Vojvodina, Serbia. To assess the safety of Danube water for bathing, physical, chemical, bacteriological tests were performed. While many parameters for monitoring the quality of water are regulated by law, there are neither national nor international legislations addressing the presence of viruses in recreational waters. In this study, we performed analyses that surpassed national requirements, and investigated if adenovirus, enterovirus or rotavirus genetic material was present in samples of recreational water collected for quality monitoring. Of 90 water samples obtained during the study, enterovirus material was not found in any sample, but adenovirus and rotavirus genetic materials were respectively detected in 60 and 31 samples. Statistical analyses showed a significant correlation between adenovirus DNA and total coliforms in the water. Even when water samples were adequate for recreational use, adenoviruses were detected in 75% (57/76) of such samples. Our results indicate that implementation of viral indicators in recreational water might be helpful to better assess public health safety. This might be particularly relevant in areas where urban wastewater treatment is insufficient and surface waters affected by wastewater are used for recreation. PMID:27105473

  8. The Danube so colourful: A potpourri of plastic litter outnumbers fish larvae in Europe's second largest river

    PubMed Central

    Lechner, Aaron; Keckeis, Hubert; Lumesberger-Loisl, Franz; Zens, Bernhard; Krusch, Reinhard; Tritthart, Michael; Glas, Martin; Schludermann, Elisabeth

    2014-01-01

    Previous studies on plastic pollution of aquatic ecosystems focused on the world's oceans. Large rivers as major pathways for land-based plastic litter, has received less attention so far. Here we report on plastic quantities in the Austrian Danube. A two year survey (2010, 2012) using stationary driftnets detected mean plastic abundance (n = 17,349; mean ± S.D: 316.8 ± 4664.6 items per 1000 m−3) and mass (4.8 ± 24.2 g per 1000 m−3) in the river to be higher than those of drifting larval fish (n = 24,049; 275.3 ± 745.0 individuals. 1000 m−3 and 3.2 ± 8.6 g 1000 m−3). Industrial raw material (pellets, flakes and spherules) accounted for substantial parts (79.4%) of the plastic debris. The plastic input via the Danube into the Black Sea was estimated to 4.2 t per day. PMID:24602762

  9. Occurrence and distribution of polycyclic aromatic hydrocarbons in surface water and sediments of the Danube River and its tributaries, Hungary.

    PubMed

    Nagy, Andrea Szabó; Szabó, János; Vass, István

    2014-01-01

    Polycyclic aromatic hydrocarbons (PAHs) were identified and quantified in surface water and sediments from 9 sites in the Hungarian upper section of the Danube River and its tributaries in autumn 2012. The total PAH concentrations (sum of the concentrations of 17 individual PAH compounds) in water samples ranged from 67 to 96 ng L(-1), which were predominated by two- and three-ring PAHs. The total PAH concentrations in sediments ranged from 35.2 to 288.3 ng g(-1) dw. Four-ring PAHs including fluoranthene and pyrene were the dominant species in sediment samples. The spatial distribution of PAHs in sediments was site-specific. The highest benzo[a]pyrene equivalent concentration was determined at the site located near a hazardous waste incinerator. However, the comparison of the total PAH concentrations determined with other sections of the Danube River and the environmental quality standards revealed that the PAH concentrations are relatively low in the Hungarian upper section. A selected number of concentration ratios of specific PAH compounds reflected a pattern of pyrogenic input as a major source of PAHs. PMID:24844894

  10. Estimating emissions of PFOS and PFOA to the Danube River catchment and evaluating them using a catchment-scale chemical transport and fate model.

    PubMed

    Lindim, C; Cousins, I T; vanGils, J

    2015-12-01

    Novel approaches for estimating the emissions of perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) to surface waters are explored. The Danube River catchment is used to investigate emissions contributing to riverine loads of PFOS and PFOA and to verify the accuracy of estimates using a catchment-scale dynamic fugacity-based chemical transport and fate model (STREAM-EU; Spatially and Temporally Resolved Exposure Assessment Model for European basins). Model accuracy evaluation performed by comparing STREAM-EU predicted concentrations and monitoring data for the Danube and its tributaries shows that the best estimates for PFOS and PFOA emissions in the Danube region are obtained by considering the combined contributions of human population, wealth (based on local gross domestic product (GDP)) and wastewater treatment. Human population alone cannot explain the levels of PFOS and PFOA found in the Danube catchment waters. Introducing wealth distribution information in the form of local GDPs improves emission estimates markedly, likely by better representing emissions resulting from consumer trends, industrial and commercial sources. For compounds such as PFOS and PFOA, whose main sink and transport media is the aquatic compartment, a major source to freshwater are wastewater treatment plants. Introducing wastewater treatment information in the emission estimations also further improves emission estimates. PMID:26367703

  11. A comparison of large 18th-century floods on Danube: Vienna - Bratislava - Budapest

    NASA Astrophysics Data System (ADS)

    Kiss, Andrea; Parajka, Juraj

    2013-04-01

    The documentation of historic floods can help in better understanding of factors that might cause and contribute to large and extreme flood events. In particular, the analysis of historic floods provides information about flood seasonality, its changes and anthropogenic impacts on river flood regime which in some cases strongly influenced flood behaviour. The main objective of the present contribution is to document large and medium size flood events on Danube in Vienna, Bratislava and Budapest in the 18th century. In the present study, based on contemporary documentary evidence, for each of the three towns a five-scaled flood index series is developed to describe the magnitude and intensity of flood events. According to this classification, the 100-year flood event was characterised by the index value 5, while great destructive floods - depending on their extension, destructivity and further impacts - received the values 4 and 3, respectively. Less significant but still harmful flood events were classified as No. 2, and floods without further specification remained in the lowest category (No. 1). Beside classification issues, seasonality and flood frequency differences between the three towns are as well discussed. The results indicate that a greater number of flood events took place in the last decades of the century, but only a few flood events of the same magnitude are documented simultaneously in all three towns. And whereas in 1775 no winter flood event was reported in Vienna, an important ice jam flood was documented in Bratislava, and a catastrophic ice jam flood event, greatest of the century, occurred in Budapest. In 1787 autumn the greatest flood event of the century occurred in Vienna, while hardly any flood waves were observed at Budapest. While in Vienna, summer (and partly autumn) floods had great importance, in Budapest a large number of ice jam floods were documented. In some cases the differences are likely caused by different hydrometeorological

  12. Sediment dynamics and heavy metal pollution history of the Cruhlig Lake (Danube Delta, Romania).

    PubMed

    Begy, Róbert-Csaba; Preoteasa, Luminita; Timar-Gabor, Alida; Mihăiescu, Radu; Tănăselia, Claudiu; Kelemen, Szabolcs; Simon, Hedvig

    2016-03-01

    This is the first study reporting recent sedimentation rates data (e.g. the past 120-150 years) for the Cruhlig Lake situated in the Danube Delta. The aim of this study is to analyse the recent sedimentation rates using the (210)Pb dating method and identifying the heavy metal pollutants and their variability in time. Five sediment cores were taken with a gravity corer and - after drying the sliced samples-physical parameters, organic material and inorganic carbon content were determined. The total (210)Pb content was measured via (210)Po by alpha spectrometry, while supported (210)Pb was measured by (226)Ra (trough short life (222)Rn daughters) with HPGe detectors. Heavy metals were determined by ICP-MS; from the 64 measured elements, only exceeding values of Al, As, Cd, Co, Cs, Cr, Cu, Fe, Hg, K, Li, Mg, Mn, Ni, Pb and Zn are discussed. After applying the CRS model, ages and sedimentation rates were calculated. The average sedimentation rate of the Cruhlig Lake is 0.21 ± 0.02 g/cm(2)y, Minimum values (0.05 ± 0.003 g/cm(2)y) are registered along the eastern shoreline of the lake before 1913, while maximum values are recorded due to the flooding in 2006 in the western side (1.34 ± 0.12 g/cm(2)y). Recent sedimentation rates divide the lake into three areas: the secluded eastern near shore part (0.63 ± 0.07 g/cm(2)y), the centre of the lake (0.92 ± 0.05 g/cm(2)y) and the dynamic western area, where most sediment transport takes place (1.13 ± 0.01 g/cm(2)y). The sedimentation pattern proves this lake to be very sensitive to fluvial discharge fluctuations. The building of the Iron Gate dams (1972 and 1985) had a negative impact on the sedimentation decreasing it with 58.74%, while after 1989 these values grew 2.25 times. The lake received a quantity of sediment rich in heavy metals in 1992 ± 3 y, which settled mostly on the eastern part. Values for Cd, Co, Cr, Hg, Pb and Zn are up to five times higher in 1980 ± 5 y in the eastern part of the lake, while Cd, Co

  13. Relative influence of chemical and non-chemical stressors on invertebrate communities: a case study in the Danube River.

    PubMed

    Rico, Andreu; Van den Brink, Paul J; Leitner, Patrick; Graf, Wolfram; Focks, Andreas

    2016-11-15

    A key challenge for the ecological risk assessment of chemicals has been to evaluate the relative contribution of chemical pollution to the variability observed in biological communities, as well as to identify multiple stressor groups. In this study we evaluated the toxic pressure exerted by >200 contaminants to benthic macroinvertebrates in the Danube River using the Toxic Unit approach. Furthermore, we evaluated correlations between several stressors (chemical and non-chemical) and biological indices commonly used for the ecological status assessment of aquatic ecosystems. We also performed several variation partitioning analyses to evaluate the relative contribution of contaminants and other abiotic parameters (i.e. habitat characteristics, hydromorphological alterations, water quality parameters) to the structural and biological trait variation of the invertebrate community. The results of this study show that most biological indices significantly correlate to parameters related to habitat and physico-chemical conditions, but showed limited correlation with the calculated toxic pressure. The calculated toxic pressure, however, showed little variation between sampling sites, which complicates the identification of pollution-induced effects. The results of this study show that the variation in the structure and trait composition of the invertebrate community are mainly explained by habitat and water quality parameters, whereas hydromorphological alterations play a less important role. Among the water quality parameters, physico-chemical parameters such as suspended solids, nutrients or dissolved oxygen explained a larger part of the variation in the invertebrate community as compared to metals or organic contaminants. Significant correlations exist between some physico-chemical measurements (e.g. nutrients) and some chemical classes (i.e. pharmaceuticals, chemicals related to human presence) which constitute important multiple stressor groups. This study

  14. Natural levee formation along a large and regulated river: The Danube in the National Park Donau-Auen, Austria

    NASA Astrophysics Data System (ADS)

    Klasz, Gerhard; Reckendorfer, Walter; Gabriel, Hannes; Baumgartner, Christian; Schmalfuss, Roland; Gutknecht, Dieter

    2014-06-01

    We investigated overbank deposition and natural levee formation along the Danube east of Vienna based on airborne laserscan data (ALS) combined with historical information. The analyses of equally spaced cross sections, hypsographic curves and point elevations revealed the significance of the distance from the river bank, the floodplain width and the floodplain flow situation (inflow/outflow sections) for the spatial variability of sediment deposition. Deposition was high near the banks (natural levee formation), in wide floodplain sections and in inflow areas. The overall pattern was modified by the presence of side-channels and the micro-relief of the floodplain. From the derived sedimentation rates (averaged for the past 120 years over the reach) of about 11.0 mm yr- 1 at the natural levee and about 0.3 mm yr- 1 at the flood protection dyke, we can estimate an overbank deposit rate of 416,000 m3 yr- 1 for the entire free-flowing reach (between river-km 1921 and 1880), that is, between 18 and 20% of the annual transported suspended load. An analysis of historical cross sections showed that there was no natural levee along the riverbanks shortly after the regulation, about 100 years ago. We thus assume that natural levee formation is a consequence of the Danube regulation in the late 19th century. Under natural conditions overbank deposition was balanced and limited by side erosion and lateral channel migration. After stabilization of the banks the overbank deposits were not eroded, and distinct ‘natural’ levees formed. These levees will develop and grow further and affect flood protection and floodplain ecology. We discuss the interplay between floodplain deposition and lateral bank migration under the concept of dynamic equilibrium.

  15. Organochlorine pesticides and polychlorinated biphenyls in surface soils of Novi Sad and bank sediment of the Danube River.

    PubMed

    Skrbic, Biljana; Cvejanov, Jelena; Durisic-Mladenovic, Natasa

    2007-01-01

    The contents of 16 organochlorine pesticides (OCPs) and six so-called indicator polychlorinated biphenyls (PCBs) were determined in the surface zone (0-5 cm) of soil and sediment samples, taken from different locations in the city of Novi Sad, capitol of Vojvodina Province (North of the Serbia) covering residential and commercial area, recreational and arable zone. The total organochlorine pesticides concentration in soil varied from 2.63 to 31.78 ng g(-1) dry weight, while the level in sediment was 10.35 ng g(-1) dry weight. Maximum content of identified individual organochlorine pesticide in soil samples was 10.40 ng g(-1) dry weight for p, p-DDE in the market garden and 6.31 ng g(-1) dry weight for p, p'-DDT in sediment of the Danube River, although their application is restricted in Serbia. Some of investigated PCBs were identified only in the soil samples from a park-school backyard in the city downtown (0.32 ng g(-1) dry weight) and market garden (0.22 ng g(-1) dry weight), and also in sediment sample from left bank of the Danube River (0.41 ng g(-1) dry weight). Data of the OCPs and PCBs present in this study were compared with the ones found for soils and river sediments throughout the world, and with limit values set by soil and sediment quality guidelines. Also, correlation between the levels of certain pesticides and soil characteristics (organic matter, pH and clay content) was investigated.

  16. Relative influence of chemical and non-chemical stressors on invertebrate communities: a case study in the Danube River.

    PubMed

    Rico, Andreu; Van den Brink, Paul J; Leitner, Patrick; Graf, Wolfram; Focks, Andreas

    2016-11-15

    A key challenge for the ecological risk assessment of chemicals has been to evaluate the relative contribution of chemical pollution to the variability observed in biological communities, as well as to identify multiple stressor groups. In this study we evaluated the toxic pressure exerted by >200 contaminants to benthic macroinvertebrates in the Danube River using the Toxic Unit approach. Furthermore, we evaluated correlations between several stressors (chemical and non-chemical) and biological indices commonly used for the ecological status assessment of aquatic ecosystems. We also performed several variation partitioning analyses to evaluate the relative contribution of contaminants and other abiotic parameters (i.e. habitat characteristics, hydromorphological alterations, water quality parameters) to the structural and biological trait variation of the invertebrate community. The results of this study show that most biological indices significantly correlate to parameters related to habitat and physico-chemical conditions, but showed limited correlation with the calculated toxic pressure. The calculated toxic pressure, however, showed little variation between sampling sites, which complicates the identification of pollution-induced effects. The results of this study show that the variation in the structure and trait composition of the invertebrate community are mainly explained by habitat and water quality parameters, whereas hydromorphological alterations play a less important role. Among the water quality parameters, physico-chemical parameters such as suspended solids, nutrients or dissolved oxygen explained a larger part of the variation in the invertebrate community as compared to metals or organic contaminants. Significant correlations exist between some physico-chemical measurements (e.g. nutrients) and some chemical classes (i.e. pharmaceuticals, chemicals related to human presence) which constitute important multiple stressor groups. This study

  17. Cartographic evidence of the disastrous ice flood of 1809 and its aftermath (Danube River, Slovakia).

    NASA Astrophysics Data System (ADS)

    Pišút, P.

    2009-04-01

    The 18th and early 19th century river maps are important data sources for studying past landscapes. This is not only as a result of improved surveying techniques, but also because they depict landscape during probably the most important climatic and land-use changes since the Middle Ages. In this phase of the increased river activity during the last onset of the so-called Little Ice Age period, several major flood events occured. Local manuscript maps, which often depict the channel in major detail, help us to obtain a better understanding of their geomorphic and other impacts. The catastrophic ice flood, which occured on the Middle Danube river at the end of January 1809 was undoubtedly the most disastrous event of its kind in Slovakia, although it also hit a number of settlements in Lower Austria and Hungary. Several people drowned and the flood also resulted in great damage to settlements and livestock. Devastating effects of this flood particularly as to the towns of Bratislava and Komárno/Komárom were comparable with effects of disastrous floods of February 1830 in Vienna (Austria), March 1838 in Buda/Pest (Hungary) or 1845 flood in Prague (Czech Republic), respectively. In case of the present Slovakian capital Bratislava, on January 29, 1809, two ice barriers suddenly rose the water up to 10 m above the zero level and the river quickly overflowed its banks inundating the low-lying parts of the town. The flood blacked out communications with neighbouring regions. Record-breaking height of water led to breaches of the important right-bank embankment (constructed in 1770s). Through several openings water flooded the right bank, almost completely destroying the adjacent village of Petržalka/Engerau. The damage to Vienna highway levee was so massive that it only could be repaired 16 years later, in 1825-6 (although this was also due to Napoleonic wars). The flood also reactivated the Chorvátske rameno anabranch, 33 years after its abandonment. A number of

  18. Abundance and biomass responses of microbial food web components to hydrology and environmental gradients within a floodplain of the River Danube.

    PubMed

    Palijan, Goran

    2012-07-01

    This study investigated the relationships of time-dependent hydrological variability and selected microbial food web components. Samples were collected monthly from the Kopački Rit floodplain in Croatia, over a period of 19 months, for analysis of bacterioplankton abundance, cell size and biomass; abundance of heterotrophic nanoflagellates and nanophytoplankton; and concentration of chlorophyll a. Similar hydrological variability at different times of the year enabled partition of seasonal effects from hydrological changes on microbial community properties. The results suggested that, unlike some other studies investigating sites with different connectivity, bacterioplankton abundance, and phytoplankton abundance and biomass increased during lentic conditions. At increasing water level, nanophytoplankton showed lower sensitivity to disturbance in comparison with total phytoplankton biomass: this could prolong autotrophic conditions within the floodplain. Bacterioplankton biomass, unlike phytoplankton, was not impacted by hydrology. The bacterial biomass less affected by hydrological changes can be an important additional food component for the floodplain food web. The results also suggested a mechanism controlling bacterial cell size independent of hydrology, as bacterial cell size was significantly decreased as nanoflagellate abundance increased. Hydrology, regardless of seasonal sucession, has the potential to structure microbial food webs, supporting microbial development during lentic conditions. Conversely, other components appear unaffected by hydrology or may be more strongly controlled by biotic interactions. This research, therefore, adds to understanding on microbial food web interactions in the context of flood and flow pulses in river-floodplain ecosystems.

  19. Improving the sampling strategy of the Joint Danube Survey 3 (2013) by means of multivariate statistical techniques applied on selected physico-chemical and biological data.

    PubMed

    Hamchevici, Carmen; Udrea, Ion

    2013-11-01

    The concept of basin-wide Joint Danube Survey (JDS) was launched by the International Commission for the Protection of the Danube River (ICPDR) as a tool for investigative monitoring under the Water Framework Directive (WFD), with a frequency of 6 years. The first JDS was carried out in 2001 and its success in providing key information for characterisation of the Danube River Basin District as required by WFD lead to the organisation of the second JDS in 2007, which was the world's biggest river research expedition in that year. The present paper presents an approach for improving the survey strategy for the next planned survey JDS3 (2013) by means of several multivariate statistical techniques. In order to design the optimum structure in terms of parameters and sampling sites, principal component analysis (PCA), factor analysis (FA) and cluster analysis were applied on JDS2 data for 13 selected physico-chemical and one biological element measured in 78 sampling sites located on the main course of the Danube. Results from PCA/FA showed that most of the dataset variance (above 75%) was explained by five varifactors loaded with 8 out of 14 variables: physical (transparency and total suspended solids), relevant nutrients (N-nitrates and P-orthophosphates), feedback effects of primary production (pH, alkalinity and dissolved oxygen) and algal biomass. Taking into account the representation of the factor scores given by FA versus sampling sites and the major groups generated by the clustering procedure, the spatial network of the next survey could be carefully tailored, leading to a decreasing of sampling sites by more than 30%. The approach of target oriented sampling strategy based on the selected multivariate statistics can provide a strong reduction in dimensionality of the original data and corresponding costs as well, without any loss of information.

  20. Metal concentrations in water, sediment and three fish species from the Danube River, Serbia: a cause for environmental concern.

    PubMed

    Ivanović, Jelena; Janjić, Jelena; Baltić, Milan; Milanov, Raša; Bošković, Marija; Marković, Radmila V; Glamočlija, Nataša

    2016-09-01

    The aim of this study was to investigate the presence of metal contamination in water, sediments and three different fish species. All samples were taken from the Danube River in Belgrade Region, a location upstream from Grocka. Concentrations of Cd, Hg and Pb in water samples were not detected, while concentrations of Zn, Fe, Cu and As were in the range of 0.004-0.41 mg L(-1). Iron was the most deposited metal in sediment samples (17,530.00 mg kg(-1)). For the purpose of heavy metal determination in fish tissue, silver carp, common carp and wels catfish were collected. Concentrations of Pb, Cd and As were determined in muscle, digestive tract and liver by inductively coupled plasma-optical emission spectrophotometry (IPC-OES). The highest concentration of Pb was in the digestive tract of all three fish species, while Cd was mostly deposited in the liver. The highest concentration of Hg was in the muscle tissue of wels catfish, and these values are above the maximum residual levels prescribed by the European Union and the maximum allowed concentrations (MACs) for Serbia. Concentration of As was mostly deposited in the liver, but under the MAC. PMID:27211095

  1. Source identification, spatio-temporal distribution and ecological risk of persistent organic pollutants in sediments from the upper Danube catchment.

    PubMed

    Kukučka, Petr; Audy, Ondřej; Kohoutek, Jiří; Holt, Eva; Kalábová, Tereza; Holoubek, Ivan; Klánová, Jana

    2015-11-01

    Riverine sediments, collected on a monthly basis during a period of one year, from five sites in a mixed land use region of the Czech Republic were analysed for chlorinated and brominated persistent organic pollutants (POPs). The region is located in the upper catchment of the Danube River. The POPs concentrations were as follows: 11-930 pg g(-1) polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs/Fs), 170-980 pg g(-1) dioxin-like polychlorinated biphenyls (dl-PCBs), 34-13,700 pg g(-1) polychlorinated naphthalenes (PCNs), 5.7-29,200 pg g(-1) polybrominated diphenylethers (PBDEs) and 0.21-351 ng g(-1) hexabromocyclododecanes (HBCDs). Concentrations expressed as toxic equivalents (TEQs), for PCDD/F+dl-PCB+PCN (TEQPCDD/F+dl-PCB+PCN) ranged from 0.37 to 19 pg g(-1). The results revealed a clear spatial separation between sites based on concentration and congener profile. There were also some obvious temporal patterns of selected POPs, which were related to river flow (seasonality) and organic carbon (TOC) of the sediment. Potential sources of POPs include local municipalities (flame retardants), some diffuse sources (PCNs and PCDDs/Fs) and potential point sources (PBDEs). Risk assessment based on risk quotients (RQ) revealed limited to medium ecological risk from PBDEs. TEQPCDD/F+dl-PCB+PCN were low relative to other European rivers, hence the risk to aquatic organisms was considered to be low. PCNs contributed significantly to overall TEQ in several cases. PMID:26291759

  2. Metal concentrations in water, sediment and three fish species from the Danube River, Serbia: a cause for environmental concern.

    PubMed

    Ivanović, Jelena; Janjić, Jelena; Baltić, Milan; Milanov, Raša; Bošković, Marija; Marković, Radmila V; Glamočlija, Nataša

    2016-09-01

    The aim of this study was to investigate the presence of metal contamination in water, sediments and three different fish species. All samples were taken from the Danube River in Belgrade Region, a location upstream from Grocka. Concentrations of Cd, Hg and Pb in water samples were not detected, while concentrations of Zn, Fe, Cu and As were in the range of 0.004-0.41 mg L(-1). Iron was the most deposited metal in sediment samples (17,530.00 mg kg(-1)). For the purpose of heavy metal determination in fish tissue, silver carp, common carp and wels catfish were collected. Concentrations of Pb, Cd and As were determined in muscle, digestive tract and liver by inductively coupled plasma-optical emission spectrophotometry (IPC-OES). The highest concentration of Pb was in the digestive tract of all three fish species, while Cd was mostly deposited in the liver. The highest concentration of Hg was in the muscle tissue of wels catfish, and these values are above the maximum residual levels prescribed by the European Union and the maximum allowed concentrations (MACs) for Serbia. Concentration of As was mostly deposited in the liver, but under the MAC.

  3. Common barbel (Barbus barbus) as a bioindicator of surface river sediment pollution with Cu and Zn in three rivers of the Danube River Basin in Serbia.

    PubMed

    Morina, Arian; Morina, Filis; Djikanović, Vesna; Spasić, Sladjana; Krpo-Ćetković, Jasmina; Kostić, Bojan; Lenhardt, Mirjana

    2016-04-01

    River sediments are a major source of metal contamination in aquatic food webs. Due to the ability of metals to move up the food chain, fishes, occupying higher trophic levels, are considered to be good environmental indicators of metal pollution. The aim of this study was to analyze the metal content in tissues of the common barbel (Barbus barbus), a rheophilous cyprinid fish widely distributed in the Danube Basin, in order to find out if it can be used as a bioindicator of the metal content in the river sediment. We analyzed bioavailable concentrations of 15 elements (Al, As, B, Ba, Co, Cr, Cu, Hg, Mn, Mo, Ni, Pb, Se, Sr, and Zn) in sediments of the Danube (D), the Zapadna Morava (ZM), and the Južna Morava (JM) using the inductively coupled plasma spectroscopy (ICP-OES). The barbel specimens were collected in the proximity of sediment sampling sites for the analysis of metals in four tissues, gills, muscle, intestine, and liver. The sediment analysis indicated that the ZM is the most polluted with Cu, Ni, and Zn compared to other two rivers. The JM had the lowest concentrations of almost all observed elements, while the Danube sediments were mainly characterized by higher concentrations of Pb. The fish from the ZM had the highest concentration of Cu and Ni in the liver and intestine, and of Zn in the muscle tissue, which was in accordance with the concentrations of these metals in the sediment. Scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM-EDS) was used for further analyses of metal interactions with fish tissues. The results suggest that the barbel can potentially be used as a bioindicator of sediment quality with respect to metal contamination.

  4. Assimilation and Calibration Approach for WGHM Using Gridded GRACE Observations: Validation for the Mississippi, Amazon and Danube Basin

    NASA Astrophysics Data System (ADS)

    Schumacher, Maike; Kusche, Jürgen; Eicker, Annette; Müller Schmied, Hannes; Döll, Petra

    2014-05-01

    Global hydrological models describe the terrestrial water cycle with detailed spatial and temporal resolution; e.g. the WaterGAP Global Hydrology Model (WGHM) simulates the vertical and horizontal water fluxes on a 0.5°x0.5° grid with daily resolution. On the other hand, the column-integrated sum of total water storage (TWS) changes can be derived from Gravity Recovery And Climate Experiment (GRACE) observations. An assimilating hydrological model that combines the advantages of detailed model resolution and accurate water storage measurements would be of great benefit for geophysical applications. Daily GRACE assimilated model outputs have the potential for being used for de-aliasing of GRACE products, replacing missing GRACE solutions or providing trends to separate GIA and perform ice mass corrections. In our group, a new ensemble Kalman filter approach has been developed to improve WGHM. The method assimilates GRACE-derived gridded TWS changes and calibrates WGHM parameters. The model-derived states and satellite measurements and their error information are used to determine updated water storage states. Since hydrological models do not provide error information, an empirical covariance matrix needs to be estimated. In this study, we focus on the validation of the performance of our approach. Therefore, GRACE data is assimilated into WGHM and its parameters are calibrated over a certain period of time. Afterwards, a free model run, considering the calibrated parameters and assimilated states, is performed for the following years. The predicted TWS values are then compared with those of GRACE observations and the original model outputs. We also validate the assimilated model outputs against independent discharge measurements. We applied our method to the Mississippi and Amazon basin, which exhibit a strong TWS signal, and the Danube basin, which represents a moderate signal.

  5. Modelling of dissolved oxygen in the Danube River using artificial neural networks and Monte Carlo Simulation uncertainty analysis

    NASA Astrophysics Data System (ADS)

    Antanasijević, Davor; Pocajt, Viktor; Perić-Grujić, Aleksandra; Ristić, Mirjana

    2014-11-01

    This paper describes the training, validation, testing and uncertainty analysis of general regression neural network (GRNN) models for the forecasting of dissolved oxygen (DO) in the Danube River. The main objectives of this work were to determine the optimum data normalization and input selection techniques, the determination of the relative importance of uncertainty in different input variables, as well as the uncertainty analysis of model results using the Monte Carlo Simulation (MCS) technique. Min-max, median, z-score, sigmoid and tanh were validated as normalization techniques, whilst the variance inflation factor, correlation analysis and genetic algorithm were tested as input selection techniques. As inputs, the GRNN models used 19 water quality variables, measured in the river water each month at 17 different sites over a period of 9 years. The best results were obtained using min-max normalized data and the input selection based on the correlation between DO and dependent variables, which provided the most accurate GRNN model, and in combination the smallest number of inputs: Temperature, pH, HCO3-, SO42-, NO3-N, Hardness, Na, Cl-, Conductivity and Alkalinity. The results show that the correlation coefficient between measured and predicted DO values is 0.85. The inputs with the greatest effect on the GRNN model (arranged in descending order) were T, pH, HCO3-, SO42- and NO3-N. Of all inputs, variability of temperature had the greatest influence on the variability of DO content in river body, with the DO decreasing at a rate similar to the theoretical DO decreasing rate relating to temperature. The uncertainty analysis of the model results demonstrate that the GRNN can effectively forecast the DO content, since the distribution of model results are very similar to the corresponding distribution of real data.

  6. Biogeography and phylogenetic position of a warm-stenotherm centric diatom, Skeletonema potamos (C.I. Weber) hasle and its long-term dynamics in the River Danube.

    PubMed

    Duleba, Mónika; Ector, Luc; Horváth, Zsófia; Kiss, Keve Tihamér; Molnár, Levente Farkas; Pohner, Zsuzsanna; Szilágyi, Zsuzsa; Tóth, Bence; Vad, Csaba Ferenc; Várbíró, Gábor; Acs, Éva

    2014-09-01

    Skeletonema potamos is a poorly known freshwater species in the ancestrally and predominantly marine genus Skeletonema. With phylogenetic analysis of two nuclear {partial SSU (18S) and partial LSU (28S) rDNA)} and two chloroplast (rbcL and psbC) genes, we verified its placement within the genus Skeletonema and identified the mostly brackish species, Skeletonema subsalsum, as its closest known relative. Comparisons of SSU and LSU rRNA genes from S. potamos populations from Europe and North America revealed no intraspecific variation. Skeletonema potamos can be a dominant element of the phytoplankton community in various ecosystems, including the River Danube. We tracked phytoplankton composition in the River Danube weekly from 1979 to 2 012, and throughout this period, S. potamos exhibited a strong increase in proportion of total phytoplankton abundance and biomass - an increase that was correlated with increasing water temperature over the same time period. Current records indicate a temperate distribution of S. potamos, but ecological data predict possible expansion of its geographic range and increase in seasonal duration within existing habitats in response to the warming of surface waters.

  7. Estimation of water turbidity and analysis of its spatio-temporal variability in the Danube River plume (Black Sea) using MODIS satellite data

    NASA Astrophysics Data System (ADS)

    Constantin, Sorin; Doxaran, David; Constantinescu, Ștefan

    2016-01-01

    Ocean colour remote sensing information brings important insights for monitoring coastal areas. These regions are home to important natural ecosystems and changes that occur here can have important impacts not only on the local environment, but also on connected wetlands or offshore areas. The present study proposes a new regional methodology for water turbidity retrieval using the MODIS red band at 250 m spatial resolution in the Danube Delta coastal area. For this purpose, multiple in-situ turbidity observations were used in order to determine a valid relationship between data collected with turbidity meters and remote sensing reflectance obtained from satellite data. A special attention is given to the atmospheric correction of satellite data, since complex optical waters require adapted methodologies for accurate remote sensing reflectance computation. Based on products derived using the proposed algorithm, the dynamics of turbidity is evaluated for multiple time periods: from local Terra to Aqua overpasses (couple of hours), daily and monthly. Results show a clear strong connection between the Danube discharge and water turbidity in the coastal area. However other environmental parameters (e.g., wind stress) also play an important role and contribute to the magnitude of the river plume extension.

  8. Levels and distribution of organochlorine pesticides, polychlorinated biphenyls and polybrominated diphenyl ethers in sediments and biota from the Danube Delta, Romania.

    PubMed

    Covaci, Adrian; Gheorghe, Adriana; Hulea, Orieta; Schepens, Paul

    2006-03-01

    Concentrations of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and organochlorine pesticides (OCPs), such as dichlorodiphenyltrichloroethane (DDT) and analogues, hexachlorocyclohexanes (HCHs) and hexachlorobenzene (HCB), were measured in sediments and biota (invertebrates, 11 fish species and cormorant tissues) collected in 2001 from the Danube Delta, the biggest European wetland. DDTs were the predominant pollutants in all samples. A high variability in the concentrations of pollutants within the same species was observed and this was related to sampling location, age, length and sex. DDTs were also the main organohalogenated contaminants in cormorant muscle and liver, followed by PCBs, HCHs, HCB and PBDEs. The present levels of DDTs in cormorant tissues are lower than levels measured in cormorant eggs sampled from the Danube Delta in 1982 and 1997, respectively. The variance of delta15N for herbivores was much greater than for carnivores, while carp and bream showed higher delta15N signatures than expected, probably due to a higher dietary proportion of benthos, typically more delta15N enriched relative to pelagic biota. PMID:16112310

  9. The evaluation of hydrochemical parameters and lithological characteristics of sediments in some lakes from Danube Delta - Romania Study case: Matita, Babina, Rosu, Uzlina and Isacova Lakes - 2010.

    NASA Astrophysics Data System (ADS)

    Catianis, I.; Grosu, D.; Radan, S.

    2012-04-01

    This study attempts to estimate the quality of water and sediments from five lakes of Danube Delta - Romania. Due to the great variety of plant and animal species, delta lakes are considered sensitive ecosystems which may become quite susceptible to anthropogenic influences. The water and sediment samples were gathered from a considerable number of sampling stations during the two campaigns performed in the summer and autumn of 2010. Different techniques were applied to assay variations in surface waters and lacustrine sediment quality. Water samples measured parameters were: dissolved oxygen, temperature, electrical conductivity, total dissolved solids, pH, redox potential, nitrates, nitrites, phosphates, sulphates etc. The main lithological parameters studied were: total organic matter, carbonates and siliciclastic material. The preliminary results indicate that these investigated lakes are quite influenced by external factors as: morphological features, climatic parameters (pressure, humidity, temperature, wind-speed, rainfall etc) and their position within the deltaic hydrological network. Performed analyses showed that the correlations between different parameters differ with respect to sampling station positions. The physico-chemical characteristics of the lakes and connection canals show small variation ranges. In some sampling stations, lower concentration of oxygen and medium pH change from slightly alkaline to alkaline were incidentally observed. The registered data also confirmed the influences of seasonal characteristics. Chemical analyses do not show high values for nitrates, nitrites and sulphates. As regards to phosphate concentration we found out some higher values. In this respect, we have to perform other detailed chemical analyses in order to establish their origin in water. Overall the physico-chemical investigations reveal normal values, which are in agreement with environmental quality standards for surface waters. Sediment cores present

  10. Estimating groundwater dynamics at a Colorado River floodplain site using historical hydrological data and climate information

    NASA Astrophysics Data System (ADS)

    Chen, Jinsong; Hubbard, Susan S.; Williams, Kenneth H.; Ficklin, Darren L.

    2016-03-01

    Long-term prediction of groundwater dynamics is important for assessing water resources and their impacts on biogeochemical cycling. However, estimating future groundwater dynamics is challenging due to the wide range of spatiotemporal scales in hydrological processes and uncertainty in future climate conditions. In this study, we develop a Bayesian model to combine small-scale historical hydrological data with large-scale climate information to estimate groundwater dynamics at a floodplain site in Rifle, Colorado. Although we have only a few years of groundwater elevation measurements, we have 47 years of streamflow data from a gaging station approximately 43 km upstream and long-term climate prediction on the Upper Colorado River Basin. To estimate future daily groundwater dynamics, we first develop a time series model to downscale the monthly streamflow derived from climate information to daily streamflow, and then transform the daily streamflow to groundwater dynamics at the downstream floodplain site. We use Monte Carlo methods to estimate future groundwater dynamics at the site through sampling from the joint posterior probability distribution. The results suggest that although future groundwater levels are expected to be similar to the current levels, the timing of the high groundwater levels is predicted to occur about 1 month earlier. The developed framework is extendable to other sites to estimate future groundwater dynamics given disparate data sets and climate projections. Additionally, the obtained estimates are being used as input to a site-specific watershed reactive transport models to predict how climate-induced changes will influence future biogeochemical cycling relevant to a variety of ecosystem services.

  11. A PROBABILITY SURVEY OF SUCCESSIONAL FOREST COMPOSITION AND CONDITION IN A GREAT RIVER FLOODPLAIN LANDSCAPE

    EPA Science Inventory

    Floodplains within the Great River Ecosystems (GREs) of the central U.S. are composed of dynamic mosaics of successional habitat that (when unmodified) are typically dominated by cottonwood forest (Populus ssp.). GRE riparian habitat condition and successional dynamics are linked...

  12. Spatial complexity reduces interaction strengths in the meta-food web of a river floodplain mosaic

    USGS Publications Warehouse

    Bellmore, James Ryan; Baxter, Colden Vance; Connolly, Patrick J.

    2015-01-01

    Theory states that both the spatial complexity of landscapes and the strength of interactions between consumers and their resources are important for maintaining biodiversity and the 'balance of nature.' Spatial complexity is hypothesized to promote biodiversity by reducing potential for competitive exclusion; whereas, models show weak trophic interactions can enhance stability and maintain biodiversity by dampening destabilizing oscillations associated with strong interactions. Here we show that spatial complexity can reduce the strength of consumer-resource interactions in natural food webs. By sequentially aggregating food webs of individual aquatic habitat patches across a floodplain mosaic, we found that increasing spatial complexity resulted in decreases in the strength of interactions between predators and prey, owing to a greater proportion of weak interactions and a reduced proportion of strong interactions in the meta-food web. The main mechanism behind this pattern was that some patches provided predation refugia for species which were often strongly preyed upon in other patches. If weak trophic interactions do indeed promote stability, then our findings may signal an additional mechanism by which complexity and stability are linked in nature. In turn, this may have implications for how the values of landscape complexity, and the costs of biophysical homogenization, are assessed.

  13. Metals and arsenic in soils and corresponding vegetation at Central Elbe river floodplains (Germany).

    PubMed

    Overesch, M; Rinklebe, J; Broll, G; Neue, H-U

    2007-02-01

    Floodplain soils at the Elbe river are frequently polluted with metals and arsenic. High contents of these pollutants were detected down to subsoil layers. NH4NO3-extractable (phytoavailable) Cd, Ni, and Zn were elevated in horizons with high acidity. Among five common floodplain plant species, Artemisia vulgaris showed highest concentrations of Cd, Cu, and Hg, Alopecurus pratensis of As and Phalaris arundinacea of Ni, Pb, and Zn. Relationships were weak between metal concentrations in plants and phytoavailable stocks in soil. As and Hg uptake seems to be enhanced on long submerged soils. Enrichments of Cd and Hg are linked to a special plant community composition. Grassland herbage sampled in July/August revealed higher concentrations of As (+122%), Hg (+124%), and Pb (+3723%) than in May. To limit harmful transfers into the food chain, low-lying terraces and flood channels revealing highest contaminations or phytoavailabilities should be excluded from mowing and grazing.

  14. Passerine exposure to primarily PCDFs and PCDDs in the river floodplains near Midland, Michigan, USA.

    PubMed

    Fredricks, Timothy B; Zwiernik, Matthew J; Seston, Rita M; Coefield, Sarah J; Plautz, Stephanie C; Tazelaar, Dustin L; Shotwell, Melissa S; Bradley, Patrick W; Kay, Denise P; Giesy, John P

    2010-05-01

    House wren (Troglodytes aedon), tree swallow (Tachycineta bicolor), and eastern bluebird (Sialia sialis) tissues collected in study areas (SAs) downstream of Midland, Michigan (USA) contained concentrations of polychlorinated dibenzofurans (PCDFs) and polychlorinated dibenzo-p-dioxins (PCDDs) greater than in upstream reference areas (RAs) in the region. The sum of concentrations of PCDD/DFs (SigmaPCDD/DFs) in eggs of house wrens and eastern bluebirds from SAs were 4- to 22-fold greater compared to those from RAs, whereas concentrations in tree swallow eggs were similar among areas. Mean concentrations of SigmaPCDD/DFs and sum 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (SigmaTEQs(WHO-Avian)), based on 1998 WHO avian toxic equivalency factors, in house wren and eastern bluebird eggs ranged from 860 (430) to 1500 (910) ng/kg wet weight (ww) and 470 (150) to 1100 (510) ng/kg ww, respectively, at the most contaminated study areas along the Tittabawassee River, whereas mean concentrations in tree swallow eggs ranged from 280 (100) to 760 (280) ng/kg ww among all locations. Concentrations of SigmaPCDD/DFs in nestlings of all studied species at SAs were 3- to 50-fold greater compared to RAs. Mean house wren, tree swallow, and eastern bluebird nestling concentrations of SigmaPCDD/DFs and SigmaTEQs(WHO-Avian) ranged from 350 (140) to 610 (300) ng/kg ww, 360 (240) to 1100 (860) ng/kg ww, and 330 (100) to 1200 (690) ng/kg ww, respectively, at SAs along the Tittabawassee River. Concentrations of SigmaTEQs(WHO-Avian) were positively correlated with SigmaPCDD/DF concentrations in both eggs and nestlings of all species studied. Profiles of relative concentrations of individual congeners were dominated by furan congeners (69-84%), primarily 2,3,7,8-tetrachlorodibenzofuran and 2,3,4,7,8-pentachlorodibenzofuran, for all species at SAs on the Tittabawassee and Saginaw rivers but were dominated by dioxin congeners at upstream RAs.

  15. Polycyclic aromatic hydrocarbons in soil of the Canadian River floodplain in Oklahoma

    USGS Publications Warehouse

    Sartori, F.; Wade, T.L.; Sericano, J.L.; Mohanty, B.P.; Smith, K.A.

    2010-01-01

    The accumulation of polycyclic aromatic hydrocarbons (PAH) in soil, plants, and water may impart negative eff ects on ecosystem and human health. We quantified the concentration and distribution of 41 PAH (n = 32), organic C, total N, and S (n = 140) and investigated PAH sources using a chronosequence of floodplain soils under a natural vegetation succession. Soil samples were collected between 0- and 260-cm depth in bare land (the control), wetland, forest, and grassland areas near a closed municipal landfill and an active asphalt plant (the contaminant sources) in the north bank of the Canadian River near Norman, OK. Principal component, cluster, and correlation analyses were used to investigate the spatial distribution of PAH, in combination with diagnostic ratios to distinguish pyrogenic vs. petrogenic PAH suites. Total PAH concentration (??PAH) had a mean of 1300 ng g-1, minimum of 16 ng g-1, and maximum of 12,000 ng g-1. At 0- to 20-cm depth, ??PAH was 3500 ?? 1600 ng g-1 (mean ?? 1 SE) near the contaminant sources. The most common compounds were nonalkylated, high molecular weight PAH of pyrogenic origin, i.e., fluoranthene (17%), pyrene (14%), phenanthrene (9%), benzo(b)fluoranthene (7%), chrysene (6%), and benzo(a)anthracene (5%). ??PAH in the control (130 ?? 23 ng g -1) was comparable to reported concentrations for the rural Great Plains. Perylene had a unique distribution pattern suggesting biological inputs. The main PAH contamination mechanisms were likely atmospheric deposition due to asphalt production at the 0- to 20-cm depth and past landfill operations at deeper depths. Copyright ?? 2010 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

  16. Low elevation inland habitats of the Willamette River floodplain support enhanced denitrification

    EPA Science Inventory

    Floodplain nitrate removal via denitrification in sediment provides an important ecosystem service that may be a valuable sink for nitrate pollution. At this time, much floodplain restoration is taking place with little consideration for in-situ nutrient processing, necessitating...

  17. The Potential for Dams to Impact Lowland Meandering River Floodplain Geomorphology

    PubMed Central

    Marren, Philip M.; Grove, James R.; Webb, J. Angus; Stewardson, Michael J.

    2014-01-01

    The majority of the world's floodplains are dammed. Although some implications of dams for riverine ecology and for river channel morphology are well understood, there is less research on the impacts of dams on floodplain geomorphology. We review studies from dammed and undammed rivers and include influences on vertical and lateral accretion, meander migration and cutoff formation, avulsion, and interactions with floodplain vegetation. The results are synthesized into a conceptual model of the effects of dams on the major geomorphic influences on floodplain development. This model is used to assess the likely consequences of eight dam and flow regulation scenarios for floodplain geomorphology. Sediment starvation downstream of dams has perhaps the greatest potential to impact on floodplain development. Such effects will persist further downstream where tributary sediment inputs are relatively low and there is minimal buffering by alluvial sediment stores. We can identify several ways in which floodplains might potentially be affected by dams, with varying degrees of confidence, including a distinction between passive impacts (floodplain disconnection) and active impacts (changes in geomorphological processes and functioning). These active processes are likely to have more serious implications for floodplain function and emphasize both the need for future research and the need for an “environmental sediment regime” to operate alongside environmental flows. PMID:24587718

  18. Rates and spatial patterns of sediment dispersal across the lower Strickland River floodplain, Papua New Guinea

    NASA Astrophysics Data System (ADS)

    Swanson, K. M.; Apte, S.; Aalto, R.; Marshall, A.; Dietrich, W.

    2004-12-01

    As part of a NSF Margins Source to sink study, we are exploring the rates and patterns of floodplain sediment vertical accretion on the Middle Fly River and the lower Strickland River, Papua New Guinea. The rivers join at 6 m above sea level where tidal influences are currently weak (except at exceptionally low flow). In response to post-glacial sea level rise both rivers aggraded, but the Strickland, carrying 7 times the sediment load, twice the discharge, and transiting through a much shorter lowland reach, has built a roughly 10 times steeper slope and a much coarser bed than the Fly. We have hypothesized that as a consequence of this difference the rate of sediment loss to the floodplain will be much lower than on the Fly (which is currently about 40% for the Middle Fly Reach). Near the gravel-sand transition, the Strickland floodplain rapidly widens downstream to an average width of approximately 10 km, and the channel has built an elevated meander belt across the roughly 100 km long plain. Recently, sediment laden flood flows have occasionally spilled out of the Strickland through an oxbow and traveled along a small channel into Lake Murray. Lake Murray is directly connected to the Strickland via the Herbert River, a large, deep channel that occasionally reverses and directs Strickland waters to the Lake. To document the spatial pattern of sediment deposition, sediment cores were collected at 11 transects across the floodplain. In addition, samples were collected along the outflow channel, in Lake Murray, and in a separate oxbow fed only by a tie channel. Duplicates and, in places, triplicate core samples were taken to enable independent analysis of sedimentation rates using two methods. Mine tailings introduced into the headwaters of the Strickland since 1990, although of relatively minor importance to the total load of the lower Strickland; provide a distinct elevated Pb and Ag signature in the recently deposited sediment. In over 30 cores, 210Pb analyses have been performed to document sedimentation rates over longer periods. Analyses are still underway, but findings to date show that the two methods of estimating sedimentation rates give roughly similar rates. Across the approximately 2 km active portion of the floodplain, vertical accretion rates on average are on the order of 1 cm/yr, with rates being highest near the channel. Applying this rate uniformly across the entire active floodplain gives an annual sedimentation rate of about 2 million tonnes, which is less than 3% of the estimated annual load of 70 Mt/yr. It is unlikely that further refinement of our analyses will increase this percent to a value similar to the 40% found on the Fly. Although the current sediment loss rate to the Strickland floodplain appears to be relatively low, sediment laden flood pulses from the uplands are substantially damped out by transient flow storage in the main channel and floodplain.

  19. Insights into geomorphic and vegetation spatial patterns within dynamic river floodplains using soft classification approaches

    NASA Astrophysics Data System (ADS)

    Guneralp, I.; Filippi, A. M.; Guneralp, B.; You, M.

    2014-12-01

    Lowland rivers in broad alluvial floodplains create one of the most dynamic landscapes, governed by multiple, and commonly nonlinear, interactions among geomorphic, hydrologic, and ecologic processes. Fluvial landforms and land-cover patches composing the floodplains of lowland rivers vary in their shapes and sizes because of variations in vegetation biomass, topography, and soil composition (e.g., of abandoned meanders versus accreting bars) across space. Such floodplain heterogeneity, in turn, influences future river-channel evolution by creating variability in channel-migration rates. In this study, using Landsat 5 Thematic Mapper data and alternative image-classification approaches, we investigate geomorphic and vegetation spatial patterns in a dynamic large tropical river. Specifically, we examine the spatial relations between river-channel planform and fluvial-landform and land-cover patterns across the floodplain. We classify the images using both hard and soft classification algorithms. We characterize the structure of geomorphic landform and vegetation components of the floodplain by computing a range of class-level landscape metrics based on the classified images. Results indicate that comparable classification accuracies are accrued for the inherently hard and (hardened) soft classification images, ranging from 89.8% to 91.8% overall accuracy. However, soft classification images provide unique information regarding spatially-varying similarities and differences in water-column properties of oxbow lakes and the main river channel. Proximity analyses, where buffer zones along the river with distances corresponding to 5, 10, and 20 river-channel widths are constructed, reveal that the average size of forest patches first increase away from the river banks but they become sparse after a distance of 10 channel widths away from the river.

  20. Seasonal dynamics in methane emissions from the Amazon River floodplain to the troposphere

    NASA Technical Reports Server (NTRS)

    Devol, Allan H.; Richey, Jeffrey E.; Forsberg, Bruce R.; Martinelli, Luiz A.

    1990-01-01

    Methane fluxes to the troposphere from the three principal habitats of the floodplain of the Amazon River main stem (open waters, emergent macrophyte beds, and flooded forests) were determined along a 1700-km reach of the river during the low-water period of the annual flood cycle (November-December 1988). Overall, emissions averaged 68 mg CH4/sq m per day and were significantly lower than similar emissions determined previously for the high-water period, 184 mg CH4/sq m per day (July-August 1986). This difference was due to significantly lower emissions from floating macrophyte environments. Low-water emissions from open waters and flooded forest areas were not significantly different than at high water. A monthly time series of methane emission from eight lakes located in the central Amazon basis showed similar results. The data were used to calculate a seasonally weighted annual emission to the troposphere from the Amazon River main stem floodplain of 5.1 Tg/yr, which indicates the importance of the area in global atmospheric chemistry.

  1. Passerine Exposure to Primarily PCDFs and PCDDs in the River Floodplains Near Midland, Michigan, USA

    PubMed Central

    Zwiernik, Matthew J.; Seston, Rita M.; Coefield, Sarah J.; Plautz, Stephanie C.; Tazelaar, Dustin L.; Shotwell, Melissa S.; Bradley, Patrick W.; Kay, Denise P.; Giesy, John P.

    2009-01-01

    House wren (Troglodytes aedon), tree swallow (Tachycineta bicolor), and eastern bluebird (Sialia sialis) tissues collected in study areas (SAs) downstream of Midland, Michigan (USA) contained concentrations of polychlorinated dibenzofurans (PCDFs) and polychlorinated dibenzo-p-dioxins (PCDDs) greater than in upstream reference areas (RAs) in the region. The sum of concentrations of PCDD/DFs (ΣPCDD/DFs) in eggs of house wrens and eastern bluebirds from SAs were 4- to 22-fold greater compared to those from RAs, whereas concentrations in tree swallow eggs were similar among areas. Mean concentrations of ΣPCDD/DFs and sum 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (ΣTEQsWHO-Avian), based on 1998 WHO avian toxic equivalency factors, in house wren and eastern bluebird eggs ranged from 860 (430) to 1500 (910) ng/kg wet weight (ww) and 470 (150) to 1100 (510) ng/kg ww, respectively, at the most contaminated study areas along the Tittabawassee River, whereas mean concentrations in tree swallow eggs ranged from 280 (100) to 760 (280) ng/kg ww among all locations. Concentrations of ΣPCDD/DFs in nestlings of all studied species at SAs were 3- to 50-fold greater compared to RAs. Mean house wren, tree swallow, and eastern bluebird nestling concentrations of ΣPCDD/DFs and ΣTEQsWHO-Avian ranged from 350 (140) to 610 (300) ng/kg ww, 360 (240) to 1100 (860) ng/kg ww, and 330 (100) to 1200 (690) ng/kg ww, respectively, at SAs along the Tittabawassee River. Concentrations of ΣTEQsWHO-Avian were positively correlated with ΣPCDD/DF concentrations in both eggs and nestlings of all species studied. Profiles of relative concentrations of individual congeners were dominated by furan congeners (69–84%), primarily 2,3,7,8-tetrachlorodibenzofuran and 2,3,4,7,8-pentachlorodibenzofuran, for all species at SAs on the Tittabawassee and Saginaw rivers but were dominated by dioxin congeners at upstream RAs. Electronic supplementary material The online version of this article (doi:10.1007/s00244-009-9416-6) contains supplementary material, which is available to authorized users. PMID:19894014

  2. Flow regime effects on mature Populus fremontii (Fremont cottonwood) productivity on two contrasting dryland river floodplains

    USGS Publications Warehouse

    Andersen, Douglas C.

    2016-01-01

    I compared riparian cottonwood (Populus fremontii) productivity-discharge relationships in a relictual stand along the highly regulated Green River and in a naturally functioning stand along the unregulated Yampa River in semiarid northwest Colorado. I used multiple regression to model flow effects on annual basal area increment (BAI) from 1982 to 2011, after removing any autocorrelation present. Each BAI series was developed from 20 trees whose mean size (67 cm diameter at breast height [DBH]) was equivalent in the two stands. BAI was larger in the Yampa River stand except in 2 y when defoliating leaf beetles were present there. I found no evidence for a Yampa flood-magnitude threshold above which BAI declined. Flow variables explained ∼45% of residual BAI variability, with most explained by current-year maximum 90-d discharge (QM90) in the Yampa River stand and by a measure of the year-to-year change in QM90 in the Green River stand. The latter reflects a management-imposed ceiling on flood magnitude—Flaming Gorge Dam power plant capacity—infrequently exceeded during the study period. BAI in the relictual stand began to trend upward in 1992 when flows started to mimic a natural flow regime. Mature Fremont cottonwoods appear to be ecologically resilient. Their productivity along regulated rivers might be optimized using multiyear environmental flow designs.

  3. Seasonal dynamics in methane emissions from the Amazon River floodplain to the troposphere

    SciTech Connect

    Devol, A.H.; Richey, J.E. ); Forsberg, B.R. ); Martinelli, L.A. )

    1990-09-20

    Methane fluxes to the troposphere from the three principal habitats of the floodplain of the Amazon River main stem (open waters, emergent macrophyte beds, and flooded forests) were determined along a 1,700-km reach of the river during the low-water period of the annual flood cycle (November-December 1988). Overall, emissions averaged 68 ({plus minus} 20) mg CH{sub 4} m{sup {minus}2} d{sup {minus}1} and were significantly lower than similar emissions determined previously for the high-water period, 184 ({plus minus} 41) mg CH{sub 4} m{sup {minus}2} d{sup {minus}1} (July-August 1986). This difference was due to significantly lower emissions from floating macrophyte environments. Low-water emissions from open waters and flooded forest areas were not significantly different than at high water. A monthly time series of methane emissions from eight lakes located in the central Amazon basin showed similar results. Average annual emission from the lakes was 125 ({plus minus} 28) mg CH{sub 4} m{sup {minus}2} d{sup {minus}1}. Methane emissions from lakes were significantly higher during the high water period, again primarily due to an increase in emissions from macrophyte habitats. The data were used to calculate a seasonally weighted annual emission to the troposphere from the Amazon River main stem floodplain of 5.1 Tg yr{sup {minus}1}, which indicates the importance of the area in global atmospheric chemistry.

  4. Characterization of subsurface stratigraphy along the lower American River floodplain using electrical resistivity, Sacramento, California, 2011

    USGS Publications Warehouse

    Burton, Bethany L.; Powers, Michael H.; Ball, Lyndsay B.

    2014-01-01

    In July 2011, the U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers, completed a geophysical survey using electrical resistivity along an approximately 6-mile reach of the lower American River in Sacramento, California, to map near-surface lithological variations. This survey is a part of a manifold and comprehensive study of river-flow dynamics and geologic boundary-property knowledge necessary to estimate scour potential and levee erosion risk. Data were acquired on the left (south or west) bank between river mile 5 and 10.7 as well as a short section on the right bank from river mile 5.4 to 6. Thirteen direct-current resistivity profiles and approximately 8.3 miles of capacitively coupled resisistivity data were acquired along accessible areas of the floodplain between the levee and river bank. Capacitively coupled resistivity was used as a reconnaissance tool, because it allowed for greater spatial coverage of data but with lower resolution and depth of investigation than the DC resistivity method. The study area contains Pleistocene-age alluvial deposits, dominated by gravels, sands, silts, and clays, that vary in both lateral extent and depth. Several generations of lithologic logs were used to help interpret resistivity variations observed in the resistivity models.

  5. Bioaccessibility of arsenic in mining-impacted circumneutral river floodplain soils.

    PubMed

    Mikutta, Christian; Mandaliev, Petar N; Mahler, Nina; Kotsev, Tsvetan; Kretzschmar, Ruben

    2014-11-18

    Floodplain soils are frequently contaminated with metal(loid)s due to present or historic mining, but data on the bioaccessibility (BA) of contaminants in these periodically flooded soils are scarce. Therefore, we studied the speciation of As and Fe in eight As-contaminated circumneutral floodplain soils (≤ 21600 mg As/kg) and their size fractions using X-ray absorption spectroscopy (XAS) and examined the BA of As in the solids by in-vitro gastrointestinal (IVG) extractions. Arsenopyrite and As(V)-adsorbed ferrihydrite were identified by XAS as the predominant As species. The latter was the major source for bioaccessible As, which accounted for 5-35% of the total As. The amount of bioaccessible As increased with decreasing particle size and was controlled by the slow dissolution kinetics of ferrihydrite in the gastric environment (pH 1.8). The relative BA of As (% of total) decreased with decreasing particle size only in a highly As-contaminated soil--which supported by Fe XAS--suggests the formation of As-rich hydrous ferric oxides in the gastric extracts. Multiple linear regression analyses identified Al, total As, C(org), and P as main predictors for the absolute BA of As (adjusted R(2) ≤ 0.977). Health risk assessments for residential adults showed that (i) nearly half of the bulk soils may cause adverse health effects and (ii) particles <5 μm pose the highest absolute health threat upon incidental soil ingestion. Owing to their low abundance, however, health risks were primarily associated with particles in the 5-50 and 100-200 μm size ranges. These particles are easily mobilized from riverbanks during flooding events and dispersed within the floodplain or transported downstream. PMID:25358072

  6. Invasive riparian vegetation response to flow regimes and flood pulses in a braided river floodplain.

    PubMed

    Caruso, Brian S; Pithie, Callum; Edmondson, Laura

    2013-08-15

    This study evaluated flow regimes and flood pulse characteristics, and their influences on invasive riparian vegetation, in a free-flowing braided river in the Southern Alps, South Island, New Zealand. A 46-year gauged flow record was used to evaluate 67 flow metrics for the Ahuriri River, and five sets of colour aerial photographs over 20 years (1991-2011) were analysed to quantify temporal and spatial changes in vegetation (crack willow, Russell lupin, and grassland). The correlation between flow metrics and vegetation class cover for each aerial photo interval was analysed, and multiple regression models were developed. Significant changes in different invasive vegetation classes were found, including cover, number and sizes of patches, and distances from patches to primary channels. In addition to infrequent large floods, specific characteristics of small floods, high flows, low/baseflows, and extreme low flows had influences on different vegetation classes. Key metrics that appear to drive changes in cover and provide a useful multiple regression model include the largest flood peak, frequency of floods, and the time since the last flood for each air photo interval. Up to 25% of invasive vegetation cover was removed and bare substrate increased after the largest flood on record (approximately 50-year flood), and the amount of vegetation cover is highly variable over time and space. Within approximately six years, however, the proportion of vegetation recovered to pre-flood levels. The study reach appears to demonstrate the "shifting-mosaic steady state" conceptual model of riverine floodplains, where the total proportion of substrate, vegetation and water remain relatively constant over long time periods.

  7. Data documentation for the 1981 summer vegetation experiment. [Kansas River floodplain

    NASA Technical Reports Server (NTRS)

    Ulaby, F. T. (Principal Investigator); Brisco, B.; Allen, C.

    1982-01-01

    The mobile agricultural radar sensor was used to collect data from 31 fields in the floodplain of the Kansas River east of Lawrence, Kansas during the summer of 1981. Corn, soybeans, and wheat crops were observed from May 1 to November 11. Radar backscattering measurements were acquired at 10.2 GHz for VV and VH polarizations at 50 deg incidence angles for all fields and at 30 deg, 40 deg, 50 deg, 60 deg, and 70 deg for nine of the 31 fields. Target parameters describing the vegatation and soil characteristics, such as plant moisture, plant height, soil moisture, etc., were also measured. The methodology, radar backscatter data and associated ground-truth data obtained during this experiment are documented.

  8. Interaction Between Lakes and Terrestrial Ecosystem Dynamics in the Yukon River Floodplain, in Interior Alaska, USA

    NASA Astrophysics Data System (ADS)

    Patil, V.; Griffith, B.; Euskirchen, E. S.

    2012-12-01

    Lakes have been decreasing in size and abundance in boreal ecosystems around the world. However, while as many as 35% of lakes in parts of interior Alaska are smaller than they were 50 years ago, up to 20% of lakes in the same regions experience large annual and intra-annual fluctuations in area (flooding), which have been linked to climate patterns via winter snowpack densities and the timing of spring thaw. Lake drying and flooding regime may influence plant community dynamics (e.g. succession), productivity, nutrient availability, and respiration, and thereby affect the carbon sink strength of boreal lake-margin wetlands. Climate change is likely to amplify drying trends and alter flooding patterns simultaneously. Predicting the future dynamics of boreal wetland complexes therefore requires quantifying the effects of flooding and drying on ecosystem processes, and the relative importance of these two mechanisms. In this study, we test the following hypotheses: 1) Both drying trends and flooding regime significantly affect lake-margin productivity, composition, and C storage by affecting soil moisture and soil nutrient concentrations, 2) frequently flooding lakes are associated with elevated soil moisture and productivity, but reduced soil carbon and nitrogen content, due to the differential influence of moisture on photosynthesis and decomposition, while drying lakes should show opposite trends. This study was conducted in the Yukon Flats National Wildlife Refuge, located 150 miles north of Fairbanks Alaska. We measured aboveground biomass, aboveground net primary productivity (ANPP), and a suite of soil characteristics within 100m of the lakeshore at 16 lakes in 2011 and 2012. Soil measurements included soil moisture, peat depth, seasonal thaw depth, total soil carbon and nitrogen, and available inorganic nitrogen. We classified lakes as drying, frequently flooding, or stable using remotely sensed measurements of long term trends as well as annual & intra-annual variation in lake area over the last 30 years. Measured variables were then compared between lake categories. Preliminary results show support for our initial predictions regarding frequently flooding lakes, but do not provide strong, consistent evidence of differences in lake-margin vegetation communities or soil properties at drying versus stable lakes. Aboveground biomass and understory ANPP were highest at flooding lakes. The margins of frequently flooding lakes also tended to have more abundant shrubs, increased evergreen cover, and greater moss biomass. In addition to these aboveground patterns, we found elevated soil moisture and electrical conductivity, but reduced nitrate availability at frequently flooding sites. Average peat depth did not vary consistently between lake types. These results indicate that flooding regime has a greater influence on soil properties and vegetation in boreal wetlands than the rate and magnitude of drying in adjacent lakes. Lake dynamics and flooding regime should be considered when projecting the response of boreal wetlands to climate change.

  9. Inter- and intraspecific variation in mercury bioaccumulation by snakes inhabiting a contaminated river floodplain.

    PubMed

    Drewett, David V V; Willson, John D; Cristol, Daniel A; Chin, Stephanie Y; Hopkins, William A

    2013-04-01

    Although mercury (Hg) is a well-studied contaminant, knowledge about Hg accumulation in snakes is limited. The authors evaluated Hg bioaccumulation within and among four snake species (northern watersnakes, Nerodia sipedon; queen snakes, Regina septemvittata; common garter snakes, Thamnophis sirtalis; and rat snakes, Elaphe obsoleta [Pantherophis alleghaniensis]) from a contaminated site on the South River (Waynesboro, VA, USA) and two nearby reference sites. Total Hg (THg) concentrations in northern watersnake tail tissue at the contaminated site ranged from 2.25 to 13.84 mg/kg dry weight (mean: 4.85 ± 0.29), or 11 to 19 times higher than reference sites. Blood THg concentrations (0.03-7.04 mg/kg wet wt; mean: 2.24 ± 0.42) were strongly correlated with tail concentrations and were the highest yet reported in a snake species. Within watersnakes, nitrogen stable isotope values indicated ontogenetic trophic shifts that correlated with THg bioaccumulation, suggesting that diet plays a substantial role in Hg exposure. Female watersnakes had higher mean THg concentrations (5.67 ± 0.46 mg/kg) than males (4.93 ± 0.49 mg/kg), but no significant differences between sexes were observed after correcting for body size. Interspecific comparisons identified differences in THg concentrations among snake species, with more aquatic species (watersnakes and queen snakes) accumulating higher mean concentrations (5.60 ± 0.40 and 4.59 ± 0.38 mg/kg in tail tissue, respectively) than the more terrestrial species, garter snakes and rat snakes (1.28 ± 0.32 and 0.26 ± 0.09 mg/kg, respectively). The results of the present study warrant further investigation of potential adverse effects and will aid in prioritizing conservation efforts.

  10. The impact of nitrogen contamination and river modification on a Mississippi River floodplain lake.

    PubMed

    Karthic, Indu; Brugam, Richard B; Retzlaff, William; Johnson, Kevin

    2013-10-01

    Anthropogenic nitrogen contamination has increased in ecosystems around the world (frequently termed the "nitrogen cascade"). Coke production for steel manufacturing is often overlooked as a source of nitrogen to natural ecosystems. We examined sediment cores from a Horseshoe Lake, a floodplain lake located just East of St. Louis Missouri (USA) to test whether a coking plant effluent could be traced using stable isotopes of nitrogen and diatom microfossils. The distribution of δ(15)N values in surface sediment samples from the lake shows the highest values near the coking plant effluent. Stable isotopes of nitrogen from 4 sediment cores using a mixing model showed three sources of nitrogen since 1688 CE. The first source (active between 1688 and 1920 CE) had a calculated δ(15)N value ranging between -0.4 and 1.1‰ depending on the core. After 1920 a second source with a δ(15)N ranging between 10.6 and 15.4‰ became active. The change in these sources coincides with the construction of a coking plant on the lake shore. A third source with a value approximately 7.0‰ was present at all times and represents background. The diatom microfossil assemblages present from 1688 CE to the late 1800s are dominated by the planktonic species Aulacoseira granulata and periphytic and benthic genera Gomphonema, Cocconeis, and Lyrella. After the late 1800s the diatom assemblages are dominated by Staurosira species indicating a shift of species from high flow riverine environments to epipelic species from a lake environment. Diatom microfossils seem to track the reduction in flooding due to leveeing of the floodplain and the isolation of the lake from the river. Our results show how stable isotopes of nitrogen can be used to track nitrogen inputs from industrial sources. Diatom changes corresponded with changes in connectivity between the Mississippi River and its floodplain. PMID:23851349

  11. Geoelectrical Soil Properties of Farmlands Located on Ancient River Floodplains in EL Paso County Texas

    NASA Astrophysics Data System (ADS)

    Pegues, J. G.; Kaip, G.; Doser, D. I.

    2013-12-01

    Farming in Rio Grande flood plain deposit soils has presented challenges concerning soil salinity, soil drainage and soil collapse. Typical soil forms include Saneli silted clay loam, Harkey loam, Harkey silky loam clay and Tigua silty clay. In the lower valley farmlands of Socorro, TX, cotton and alfalfa are the principal crops, but grain sorghum, corn and vegetable crops also are suitable. Pecan trees, as well as fruit trees suited to the climate, can be grown. Agrarians are faced with varying results of crop yields over relatively small stretches of land; for example, a 22 acre area can contain multiple soil inclusions. This study was conducted on a 22 acre tract of farmland which has recently undergone multiple geophysical testing analyses that include: magnetics, DC resistivity, gravity, and ground penetrating radar. Results will compare flood plain sedimentation qualities to agricultural soil classes through the identification of soil salinity and grain size. This investigation will focus on the testing of geo-electrical soil properties through resistivity assessment. Examination of the sight using a capacity coupled resistivity meter to measure the soil properties over various time periods will be conducted. The results will be compared with the other geophysical data to look for correlations that highlight soil properties.

  12. Breeding bird assemblages associated with stages of forest succession in large river floodplains

    USGS Publications Warehouse

    Knutson, M.G.; McColl, L.E.; Suarez, S.A.

    2005-01-01

    Floodplain forests rival all other habitat types in bird density and diversity. However, major successional changes are predicted for floodplain forests along the Mississippi River in the coming decades; young forests may replace the existing mature silver maple (Acer saccharinum L.) forests in some areas. We wanted to assess how the breeding bird community might respond to these changes. We studied stands of young forests along the middle Mississippi River, comparing the breeding bird assemblages among three stages of forest succession: shrub/scrub, young cottonwood (Populus deltoides Marshall) and willow (Salix nigra Marshall) forests, and mature silver maple dominated forests. We recorded a total of 54 bird species; the most frequently observed species were the indigo bunting (Passerina cyanea), red-winged blackbird (Agelaius phoeniceus), and yellow-billed cuckoo (Coccyzus americanus). Bird species richness differed among the habitat types, with mature forests supporting the largest number of species and the most species of management concern. The shrub/scrub and mature forest bird assemblages were distinct and shared few species, but the young forests had no identifiable bird species assemblage, sharing species found in both of the other habitat types. The bird assemblages we observed in young forests may become more prevalent as aging floodplain forests are replaced with younger stages of forest succession. Under this scenario, we would expect a temporary local decrease in bird species richness and habitat for species of management concern.

  13. The potential for dams to impact lowland meandering river floodplain geomorphology.

    PubMed

    Marren, Philip M; Grove, James R; Webb, J Angus; Stewardson, Michael J

    2014-01-01

    The majority of the world's floodplains are dammed. Although some implications of dams for riverine ecology and for river channel morphology are well understood, there is less research on the impacts of dams on floodplain geomorphology. We review studies from dammed and undammed rivers and include influences on vertical and lateral accretion, meander migration and cutoff formation, avulsion, and interactions with floodplain vegetation. The results are synthesized into a conceptual model of the effects of dams on the major geomorphic influences on floodplain development. This model is used to assess the likely consequences of eight dam and flow regulation scenarios for floodplain geomorphology. Sediment starvation downstream of dams has perhaps the greatest potential to impact on floodplain development. Such effects will persist further downstream where tributary sediment inputs are relatively low and there is minimal buffering by alluvial sediment stores. We can identify several ways in which floodplains might potentially be affected by dams, with varying degrees of confidence, including a distinction between passive impacts (floodplain disconnection) and active impacts (changes in geomorphological processes and functioning). These active processes are likely to have more serious implications for floodplain function and emphasize both the need for future research and the need for an "environmental sediment regime" to operate alongside environmental flows.

  14. Geomorphic and vegetation processes of the Willamette River floodplain, Oregon: current understanding and unanswered science questions

    USGS Publications Warehouse

    Wallick, J. Rose; Jones, Krista L.; O'Connor, Jim E.; Keith, Mackenzie K.; Hulse, David; Gregory, Stanley V.

    2013-01-01

    4. How is the succession of native floodplain vegetation shaped by present-day flow and sediment conditions? Answering these questions will produce baseline data on the current distributions of landforms and habitats (question 1), the extent of the functional floodplain (question 2), and the effects of modern flow and sediment regimes on future floodplain landforms, habitats, and vegetation succession (questions 3 and 4). Addressing questions 1 and 2 is a logical next step because they underlie questions 3 and 4. Addressing these four questions would better characterize the modern Willamette Basin and help in implementing and setting realistic targets for ongoing management strategies, demonstrating their effectiveness at the site and basin scales, and anticipating future trends and conditions.

  15. [Vertical structure of bacterial communities in peats of the Yakhroma River floodplain].

    PubMed

    Dobrovol'skaia, T G; Golovchenko, A V; Pozdniakov, A I

    2007-01-01

    The abundance and taxonomic structure of soil bacterial communities have been studied in different geomorphological parts of the Yakhroma floodplain. It has been found that the numbers of bacteria reach a peak in calcareous peat soil under forest near the floodplain terrace, decreasing to a minimum in soddy alluvial soil near the riverbed. All soils are characterized by the presence of different ecological-trophic bacterial groups capable of peat destruction. Seasonal dynamics of the structure of bacterial communities and, in some soil types, its spatial dynamics accounted for by changes in the botanical structure of peat across its profile have been revealed. All peat soils in the floodplain have high contents of organic matter and neutral pH and, therefore, are favorable biotopes for the development of saprotrophic bacteria. This, in turn, largely accounts for high productivity and stability of this agroecosystem as a whole.

  16. The potential for dams to impact lowland meandering river floodplain geomorphology.

    PubMed

    Marren, Philip M; Grove, James R; Webb, J Angus; Stewardson, Michael J

    2014-01-01

    The majority of the world's floodplains are dammed. Although some implications of dams for riverine ecology and for river channel morphology are well understood, there is less research on the impacts of dams on floodplain geomorphology. We review studies from dammed and undammed rivers and include influences on vertical and lateral accretion, meander migration and cutoff formation, avulsion, and interactions with floodplain vegetation. The results are synthesized into a conceptual model of the effects of dams on the major geomorphic influences on floodplain development. This model is used to assess the likely consequences of eight dam and flow regulation scenarios for floodplain geomorphology. Sediment starvation downstream of dams has perhaps the greatest potential to impact on floodplain development. Such effects will persist further downstream where tributary sediment inputs are relatively low and there is minimal buffering by alluvial sediment stores. We can identify several ways in which floodplains might potentially be affected by dams, with varying degrees of confidence, including a distinction between passive impacts (floodplain disconnection) and active impacts (changes in geomorphological processes and functioning). These active processes are likely to have more serious implications for floodplain function and emphasize both the need for future research and the need for an "environmental sediment regime" to operate alongside environmental flows. PMID:24587718

  17. Patterns of forest succession and impacts of flood in the Upper Mississippi River floodplain ecosystem

    USGS Publications Warehouse

    Yin, Y.; Wu, Y.; Bartell, S.M.; Cosgriff, R.

    2009-01-01

    The widespread loss of oak-hickory forests and the impacts of flood have been major issues of ecological interest concerning forest succession in the Upper Mississippi River (UMR) floodplain. The data analysis from two comprehensive field surveys indicated that Quercus was one of the dominant genera in the UMR floodplain ecosystem prior to the 1993 flood and constituted 14% of the total number of trees and 28% of the total basal area. During the post-flood recovery period through 2006, Quercus demonstrated slower recovery rates in both the number of trees (4%) and basal area (17%). In the same period, Carya recovered greatly from the 1993 flood in terms of the number of trees (11%) and basal area (2%), compared to its minor status before the flood. Further analyses suggested that different species responded to the 1993 flood with varying tolerance and different succession strategies. In this study, the relation of flood-caused mortality rates and DBH, fm(d), can be expressed in negative exponential functions for each species. The results of this research also indicate that the growth functions are different for each species and might also be different between pre- and post-flood time periods. These functions indicate different survival strategies and emergent properties in responding to flood impacts. This research enhances our understanding of forest succession patterns in space and time in the UPR floodplain. And such understanding might be used to predict long-term impacts of floods on UMR floodplain forest dynamics in support of management and restoration. ?? 2009 Elsevier B.V.

  18. Bioaccessibility of arsenic in mining-impacted circumneutral river floodplain soils.

    PubMed

    Mikutta, Christian; Mandaliev, Petar N; Mahler, Nina; Kotsev, Tsvetan; Kretzschmar, Ruben

    2014-11-18

    Floodplain soils are frequently contaminated with metal(loid)s due to present or historic mining, but data on the bioaccessibility (BA) of contaminants in these periodically flooded soils are scarce. Therefore, we studied the speciation of As and Fe in eight As-contaminated circumneutral floodplain soils (≤ 21600 mg As/kg) and their size fractions using X-ray absorption spectroscopy (XAS) and examined the BA of As in the solids by in-vitro gastrointestinal (IVG) extractions. Arsenopyrite and As(V)-adsorbed ferrihydrite were identified by XAS as the predominant As species. The latter was the major source for bioaccessible As, which accounted for 5-35% of the total As. The amount of bioaccessible As increased with decreasing particle size and was controlled by the slow dissolution kinetics of ferrihydrite in the gastric environment (pH 1.8). The relative BA of As (% of total) decreased with decreasing particle size only in a highly As-contaminated soil--which supported by Fe XAS--suggests the formation of As-rich hydrous ferric oxides in the gastric extracts. Multiple linear regression analyses identified Al, total As, C(org), and P as main predictors for the absolute BA of As (adjusted R(2) ≤ 0.977). Health risk assessments for residential adults showed that (i) nearly half of the bulk soils may cause adverse health effects and (ii) particles <5 μm pose the highest absolute health threat upon incidental soil ingestion. Owing to their low abundance, however, health risks were primarily associated with particles in the 5-50 and 100-200 μm size ranges. These particles are easily mobilized from riverbanks during flooding events and dispersed within the floodplain or transported downstream.

  19. Factors influencing soil invertebrate communities in riparian grasslands of the central platte river floodplain

    USGS Publications Warehouse

    Davis, C.A.; Austin, J.E.; Buhl, D.A.

    2006-01-01

    In the Platte River Valley of central Nebraska, USA, riparian grasslands (also known as wet meadows) have been severely impacted by a reduction in river flows, causing lower ground-water levels and altered seasonal hydroperiods. The potential impacts of these hydrologic changes, as well as the environmental factors that influence wet meadow soil invertebrate communities, are not well understood. An understanding of the ecological processes that influence these invertebrate communities is crucial for maintaining and restoring wet meadows along the Platte River. Our objectives were to describe the soil invertebrate community of wet meadows throughout the growing season and to examine the relative roles of abiotic factors in determining patterns in invertebrate community structure. We conducted the study in 12 wet meadows along the Platte River during 1999 and 2000. We identified 73 invertebrate taxa; 39 were considered soil inhabitants. Total biomass was primarily composed of earthworms, Scarabaeidae, Isopoda, and Elateridae, with earthworms and Scarabaeidae accounting for >82%. Differences in river flow and precipitation patterns influenced some soil invertebrates. Earthworms and Scarabaeidae declined dramatically from 1999 (wet year) to 2000 (dry year). The topographic gradient created by the ridge-swale complex affected several soil invertebrate taxa; Scarabaeidae, Diplopoda, and Lepidoptera biomasses were greatest on drier ridges, while Tipulidae and Isopoda biomasscs were greatest in wetter sloughs. Responses of earthworm taxa to the topographic gradient were variable, but generally, greater biomasses occurred on ridges and mid-elevations. Water-table depth and soil moisture were the most important variables influencing wet meadow soil invertebrates. Because these communities are linked to the hydrologic processes of the Platte River, future alterations of wet meadow hydrology could shift the distribution patterns of many of these invertebrates and possibly eliminate more moisture-tolerant taxa. To maintain wet meadows and their biotic communities, flow management should focus on regaining as much as possible of the former hydrograph through properly timed flows that provide an adequate hydrologic regime for wet meadows. In addition, restoration of wet meadows will depend on restoring the natural topography of wet meadows. ?? 2006, The Society of Wetland Scientists.

  20. Aquatic habitats in relation to river flow in the Apalachicola River floodplain, Florida

    USGS Publications Warehouse

    Light, Helen M.; Darst, Melanie R.; Grubbs, J.W.

    1998-01-01

    This study is part of a larger effort to identify fresh water needs throughout the region and develop a mechanism for basinwide water management. Quantitative estimates of the amount of aquatic habitat in the floodplain in relation to river flow are presented. Plates show streams, lakes, and floodplain forests connected to the main river channel at selected flows; an analysis of long-term flow record in the Apalachicola River; and a review of the literature regarding fishes in floodplains of the Apalachicola River and other rivers of the Eastern United States. Examples show how this report can be used to assess impacts of flow alterations on aquatic habitats and fishes.

  1. [Vertical structure of bacterial communities in peats of the Yakhroma River floodplain].

    PubMed

    Dobrovol'skaia, T G; Golovchenko, A V; Pozdniakov, A I

    2007-01-01

    The abundance and taxonomic structure of soil bacterial communities have been studied in different geomorphological parts of the Yakhroma floodplain. It has been found that the numbers of bacteria reach a peak in calcareous peat soil under forest near the floodplain terrace, decreasing to a minimum in soddy alluvial soil near the riverbed. All soils are characterized by the presence of different ecological-trophic bacterial groups capable of peat destruction. Seasonal dynamics of the structure of bacterial communities and, in some soil types, its spatial dynamics accounted for by changes in the botanical structure of peat across its profile have been revealed. All peat soils in the floodplain have high contents of organic matter and neutral pH and, therefore, are favorable biotopes for the development of saprotrophic bacteria. This, in turn, largely accounts for high productivity and stability of this agroecosystem as a whole. PMID:18038631

  2. Polycyclic aromatic hydrocarbons in soil of the Canadian river floodplain in Oklahoma.

    PubMed

    Sartori, Fabio; Wade, Terry L; Sericano, Jose L; Mohanty, Binayak P; Smith, Kevin A

    2010-01-01

    The accumulation of polycyclic aromatic hydrocarbons (PAH) in soil, plants, and water may impart negative effects on ecosystem and human health. We quantified the concentration and distribution of 41 PAH (n = 32), organic C, total N, and S (n = 140) and investigated PAH sources using a chronosequence of floodplain soils under a natural vegetation succession. Soil samples were collected between 0- and 260-cm depth in bare land (the control), wetland, forest, and grassland areas near a closed municipal landfill and an active asphalt plant (the contaminant sources) in the north bank of the Canadian River near Norman, OK. Principal component, cluster, and correlation analyses were used to investigate the spatial distribution of PAH, in combination with diagnostic ratios to distinguish pyrogenic vs. petrogenic PAH suites. Total PAH concentration (SigmaPAH) had a mean of 1300 ng g(-1), minimum of 16 ng g(-1), and maximum of 12,000 ng g(-1). At 0- to 20-cm depth, SigmaPAH was 3500 +/- 1600 ng g(-1) (mean +/- 1 SE) near the contaminant sources. The most common compounds were nonalkylated, high molecular weight PAH of pyrogenic origin, i.e., fluoranthene (17%), pyrene (14%), phenanthrene (9%), benzo(b)fluoranthene (7%), chrysene (6%), and benzo(a)anthracene (5%). SigmaPAH in the control (130 +/- 23 ng g(-1)) was comparable to reported concentrations for the rural Great Plains. Perylene had a unique distribution pattern suggesting biological inputs. The main PAH contamination mechanisms were likely atmospheric deposition due to asphalt production at the 0- to 20-cm depth and past landfill operations at deeper depths. PMID:20176830

  3. Diazotrophy in alluvial meadows of subarctic river systems.

    PubMed

    DeLuca, Thomas H; Zackrisson, Olle; Bergman, Ingela; Díez, Beatriz; Bergman, Birgitta

    2013-01-01

    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.

  4. Organic carbon and nitrogen export from a tropical dam-impacted floodplain system

    NASA Astrophysics Data System (ADS)

    Zurbrügg, R.; Suter, S.; Lehmann, M. F.; Wehrli, B.; Senn, D. B.

    2013-01-01

    Tropical floodplains play an important role in organic matter transport, storage, and transformation between headwaters and oceans. However, the fluxes and quality of organic carbon (OC) and organic nitrogen (ON) in tropical river-floodplain systems are not well constrained. We explored the quantity and characteristics of dissolved and particulate organic matter (DOM and POM, respectively) in the Kafue River flowing through the Kafue Flats (Zambia), a tropical river-floodplain system in the Zambezi River basin. During the flooding season, > 80% of the Kafue River water passed through the floodplain, mobilizing large quantities of OC and ON, which resulted in a net export of 69-119 kg OC km-2 d-1 and 3.8-4.7 kg ON km-2 d-1, 80% of which was in the dissolved form. The elemental C : N ratio of ~ 20, the comparatively high δ13C values of -25‰ to -21‰, and its spectroscopic properties (excitation-emission matrices) showed that DOM in the river was mainly of terrestrial origin. Despite a threefold increase in OC loads due to inputs from the floodplain, the characteristics of the riverine DOM remained relatively constant along the sampled 410-km river reach. This suggests that floodplain DOM displayed properties similar to those of DOM leaving the upstream reservoir and implied that the DOM produced in the reservoir was relatively short-lived. In contrast, the particulate fraction was 13C-depleted (-29‰) and had a C : N ratio of ~ 8, which indicated that POM originated from phytoplankton production in the reservoir and in the floodplain, rather than from plant debris or resuspended sediments. While the upstream dam had little effect on the DOM pool, terrestrial particles were retained, and POM from algal and microbial sources was released to the river. A nitrogen mass balance over the 2200 km2 flooded area revealed an annual deficit of 15 500-22 100 t N in the Kafue Flats. The N isotope budget suggests that these N losses are balanced by intense N-fixation. Our

  5. Spatially and temporally varying Quaternary uplift rates of the Gerecse Hills, Northern Pannonian Basin, using dated geomorphological horizons in the Danube valley

    NASA Astrophysics Data System (ADS)

    Ruszkiczay-Rüdiger, Zsófia; Fodor, László; Csillag, Gábor; Braucher, Régis; Kele, Sándor; Novothny, Ágnes; Thamó-Bozsó, Edit; Virág, Attila; Molnár, Gábor; Madarász, Balázs; Aster Team

    2016-04-01

    The assessment of Quaternary vertical deformation rates of uplifted, low altitude hilly regions is based mainly on the dating of paleo-surfaces that can be related to reference levels through several stages of landscape evolution. Regarding the Gerecse Hills (NE part of the Transdanubian Range, Hungary), situated to the south of the incised Danube River the all-time base-level of the river provides a suitable reference level, because the intracontinental setting of the study area makes it insensitive of the global sea level changes. The terrace sequences of the Hungarian part of the Danube valley preserve a record of varying tectonic uplift rates along the river course and throughout several climate stages. The Gerecse Hills consists mainly of Triassic carbonatic rocks and a thin Paleogene and Neogene siliciclastic cover. The Danube is escorted by a set of Quaternary river terraces and higher planation surfaces, which may be of Pliocene age. The terraces are covered by alluvial sediments frequently capped by travertine and/or loess. To establish the chronology of these terraces, we rely on U-series data of travertines and on new in situ produced cosmogenic nuclides data combined with luminescence (OSL and postIR-IRSL) ages from the lower terraces. In situ produced cosmogenic 10Be concentrations were measured in samples distributed along vertical depth profiles to enable the determination of both the exposure duration and the denudation rate at each studied locality. We used Monte Carlo approach to model the denudation rate-corrected exposure ages. Burial age determinations were performed using cosmogenic 26Al/10Be nuclide ratios. Post-IR IRSL measurements were carried out on K-feldspar and OSL measurements on quartz grains to determine the ages of sediment deposition. The highest dated horizon (˜115 m above the river) provided a preliminary burial age of ˜2.7 Ma, which is in accordance with the possible time span of sedimentation deduced from the occurrence of

  6. Flood hazard and a rapidly growing capital in the floodplain: Social response on major 18th-century Danube floods in Pest (East-Budapest)

    NASA Astrophysics Data System (ADS)

    Kiss, Andrea

    2014-05-01

    Due to its floodplain location, Pest was especially prone to damages caused by great flood events. Before water regulation works, the greatest flood events, and the highest rate of destruction occurred during ice jam floods. Whereas in the first half of the 18th century Pest is restricted to the medieval downtown located on a higher terrain (Danube terrace), from the mid 18th century onwards the rapidly growing population established suburbs around the downtown in the lower-lying flood plain. Thus, while in the first half of the century floods were more dangerous for the harvest in the agricultural lands, in the second half of the century at the same place suburbs, urban areas with thousands of inhabitants were prone to the same danger. In the first half of the century at least three particularly large flood events, in 1712, 1732 and 1744, caused increasing problems in the close vicinity of the town (and its lands), the second half of the century - as part of a climatic anomaly (Maldá) famous of its weather extremes - was characterised by two extreme (in 1775 and 1799), at least two larger (1789 and 1795) and some more, medium-sized ice jam floods. While in terms of damaged houses the loss was only some dozens in the early part of the century, several hundreds of houses - actually, complete suburbs were erased by floods in 1775 and 1799. In the poster presentation a series of known damaging 18th-century floods, occurred at Pest, is presented, the short-term impacts (e.g. damages), and medium-, long-term administrative responses as well as related long-term landscape changes influenced by floods and flood protection are discussed. Another important aim of the poster is to present the main reasons why in the 18th century these great ice jam floods caused much greater damages (e.g. percentage of collapsed houses in suburbs) in Pest protected by dams than, for example, in the Buda suburbs with no dams, partly also located in high flood-risk areas, in the immediate

  7. Synergy between LIDAR and RADARSAT-2 images for the recognition of vegetation structures in the coastal wetlands of the Danube Delta

    NASA Astrophysics Data System (ADS)

    Niculescu, Simona; Lardeux, Cédric; Grigoras, Ion; Hanganu, Jenica; David, Laurence

    2014-05-01

    Wetlands are among the most productive environments in the world and are characterized by exceptional biological diversity. Despite their indisputable importance, these environments remain among the most endangered ecosystems in the world due to drainage, drying out, pollution or overexploitation of resources. The Danube Delta, a coastal wetland of the Black Sea, cannot escape these dangers and, to preserve its resources, it has been declared a Biosphere Reserve (in 1993). The biodiversity of this area is remarkable and it possesses one of the largest reed in the world (a continuous 2,700 km² reed cover). The main goal of this project is to determine, characterize and derive functional descriptors of the vegetation structures, Phragmites australis species of the Danube Delta being the most prevalent. For this purpose, this project aims, on the one hand, at interpreting LIDAR measurements (acquired in May 2011) in conjunction with RADARSAT-2 satellite observations (acquired in early June 2011) and, on the other hand, at validating the results obtained by the introduction of the spectral measurements of the main vegetation classes into a Spectral Angle Mapper algorithm applied to a SPOT-5 image (May 2011). The LIDAR data allow the assessment of vegetation height with an accuracy of a few centimeters. Hence, the various vegetation layers can be accurately mapped. However, the differentiation of the various vegetation formations within a same layer requires the contribution of complementary data sources such as RADARSAT-2 data. The radar measurements are derived using the C band (λ wavelength = 5.3 cm) providing additional information on the vegetation cover structure with regard to roughness, moisture and biomass. The simultaneous acquisition of HH, HV and VV polarizations allows the differentiation of the areas according to their response to different polarizations by establishing their polarimetric signatures. Based on these raw data, we were able to derive other

  8. Monitoring of radioactive contamination of water systems after Chernobyl accident

    SciTech Connect

    Kuznetsov, Y.V.

    1993-12-31

    The contamination of the water systems within the Russian North-West region, the Danube river and the reservoir of the Dnieper River during the period from June 1986 to 1992 was studied. The water reservoirs in the vicinity of the Chernobyl NPP contained suspended matter and the bottom sediments contained a wide range of radionuclides, including the isotopes of Pu and TPE. In the Baltic Sea and the allied river and lake reservoirs the concentrations of {sup 137}Cs ({sup 134}Cs was also detected) increased drastically, however, the concentrations of {sup 90}Sr and plutonium isotopes remained essentially at the global level. The Danube River contained increased concentrations of {sup 137}Cs and {sup 90}Sr as compared with 1985; no rise in the concentration of plutonium was observed. In subsequent years (1987--1990) the concentration of cesium isotopes in the reservoirs decreased sharply; but, on the other hand, their concentrations in sediments increased.

  9. Determination of pharmaceuticals and pesticides in river sediments and corresponding surface and ground water in the Danube River and tributaries in Serbia.

    PubMed

    Radović, Tanja; Grujić, Svetlana; Petković, Anđelka; Dimkić, Milan; Laušević, Mila

    2015-01-01

    The aim of this study was the development of analytical methods for the simultaneous determination of 25 selected pharmaceuticals, metabolites, and pesticides, belonging to the various chemical classes, in river sediments and their corresponding surface and ground water with the purpose of monitoring the contamination levels. The methods were based on the solid-phase extraction as the sample preparation method for water samples, and the ultrasonic solvent extraction for the sediment samples, followed by the liquid chromatography-tandem mass spectrometry. High recoveries were achieved for extraction from both water and sediment samples for the majority of analytes. Low limits of detection were achieved for all investigated compounds in the water sample (1-5 ng L(-1)) as well as in the sediment (1-3 ng g(-1)). Applicability of the developed methods was demonstrated by determination of pharmaceutical and pesticide residues in 30 surface water, 44 groundwater, and 5 sediment samples from the Danube River Basin in Serbia. Sixty percent of target compounds were detected in environmental samples. The most frequently detected analytes in river sediments were the pesticides dimethoate and atrazine, while carbamazepine and metamizole metabolites 4-AAA and 4-FAA were the most frequently found in water samples.

  10. River sinuosity changes as indicators of the possible neotectonic activity - a case study on the Danube River between Paks (Hungary) and Beograd (Serbia)

    NASA Astrophysics Data System (ADS)

    Petrovszki, Judit

    2010-05-01

    The meandering, pre-regulation river planforms of the Danube River, between Paks (Hungary) and Beograd (Serbia) was digitized from the map sheets of the Second Military Survey of the Habsburg Empire (Timár et al., 2006). These maps were surveyed before or simultaneously with the river control works, so it is possible to follow the natural riverbeds, the natural changing of the meandering structure. The sinuosity values were calculated with different window sizes, and displayed in a spectrum-like diagram (sinuosity spectra; after van Balen et al., 2008). The channel sinuosity of this river is analyzed in order to draw conclusions on the neotectonic activity of the western part of the Great Hungarian Plain. Several points of sinuosity change were identified. To prove that these are of neotectonic origin, a neotectonic map and seismic sections crossing the study area, were also analyzed. Significant sinuosity changes (low to high or high to low), spatially correlated to linear features identified in seismic survey sections or in tectonic maps (Horváth et al., 2006), indicate their neotectonic activity (Ouchi, 1985; Timár, 2003; Zámolyi et al., 2010). Upstream of the Hungarian-Serbian border, the Duna (Danube) has anabranching planform, the Baracskai-Duna is the main anabranch. There is a fault on the neotectonic map, crossing both rivers, and cause the decreasing of the sinuosity. The vertical activity of the structural line, which is more or less parallel to the international border, is verified by the sinuosity change. The direction of the change (from high to low sinuosity values) correlates with the normal fault character, shown on the map. Another significant sinuosity change occurs downstream of the Drava River confluence. The explanation of this change can be of two kinds. First, there is a known tectonic feature along the Drava River, with dextral faulting. The sinuosity increase could indicate a small active vertical component of this structural line

  11. In situ produced 10Be depth profiles and luminescence data tracing climatic and tectonic control on terrace formation, Danube River, Central Europe, Hungary

    NASA Astrophysics Data System (ADS)

    Ruszkiczay-Rüdiger, Zsófia; Braucher, Régis; Novothny, Ágnes; Csillag, Gábor; Fodor, László; Molnár, Gábor; Madarász, Balázs; Aster Team

    2015-04-01

    The terrace sequence of the Hungarian part of the Danube valley preserves a record of varying tectonic uplift rates along the river course and throughout several climate stages. To establish the chronology of formation of these terraces, two different dating methods on alluvial terraces were used: 1) in situ produced cosmogenic 10Be, which yield the time of abandonment of the terrace and 2) luminescence dating, which provides burial ages of the sediment. In situ produced cosmogenic 10Be samples originated from vertical depth profiles to enable the determination of both the exposure time and the denudation rate at each locality. We used Monte Carlo approach to model the denudation rate-corrected exposure ages. Post-IR IRSL measurements were carried out on K-feldspar samples to obtain the ages of sedimentation. The highest and oldest terrace remnants (tIV-VI) yield a minimum 10Be exposure age of 800 ka close to MIS 22, the onset of major continental glaciations of Quaternary age, suggesting climatic signal of the abandonment of the uppermost terrace levels. For the lower terraces it was possible to reveal close correlation with MIS stages using IRSL ages. The new chronology enables the distinction of tIIb (60-110 ka; MIS 4-5d) and tIIIa (130-190 ka; MIS 6) in the study area. Surface denudation rates were well constrained by the cosmogenic 10Be depth profiles between 5.9 m/Ma and 10.0 m/Ma for all terraces. Maximum incision rates of the Danube were calculated for middle and late Pleistocene times. These rates were increasing from west to east, toward the more elevated Transdanubian Range from 0.05 mm/a to 0.12 mm/a. Incision rates derived from the age of the low terraces (0.13 mm/a) may suggest a slight acceleration of uplift towards present. Our research was supported by the OTKA PD83610, PD100315, NK60455, K062478, K83150 and F042799, the French-Hungarian Balaton-Tét Project (FR-32/2007; TÉT_11-2-2012-0005), the Bolyai János Scholarship of the Hungarian Academy

  12. Dietary habits of invasive Ponto-Caspian gobies in the Croatian part of the Danube River basin and their potential impact on benthic fish communities.

    PubMed

    Piria, Marina; Jakšić, Goran; Jakovlić, Ivan; Treer, Tomislav

    2016-01-01

    Invasive Ponto-Caspian (P-C(1)) gobies have recently caused dramatic changes in fish assemblage structures throughout the Danube basin. While their presence in the Croatian part of the basin has been noted and distribution studied, their dietary habits and impacts on native fish communities have, until now, been unknown. In 2011, 17 locations in the Sava River Basin were sampled for fish and 15 for benthic invertebrates. Fish population monitoring data, available for nine seasons (2003-2006 and 2010-2014) and 12 locations, were used to analyse the impacts of P-C gobies on benthic fish abundance. Gut content analysis indicates that the monkey goby Neogobius fluviatilis diet is very diverse, but dominated by Trichoptera, Chironomidae, Bivalvia and Odonata. The diet overlaps considerably with the round goby Neogobius melanostomus diet, although Gastropoda are dominant in the latter's diet. Small fish and Gammarus sp. dominate the bighead goby Ponticola kessleri diet. Comparison of gut content with the prey available in the environment indicates that monkey and round gobies exhibit preference for Trichoptera, Megaloptera and Coleoptera, and bighead goby for Trichoptera, Gammarus sp. and Pisces. P-C gobies in the Sava River are spreading upstream, towards the reaches with lower fish diversity. Analyses indicate potentially positive impacts of P-C gobies' presence on some fish populations: round and bighead goby on Balkan golden loach Sabanejewia balcanica and monkey goby on common carp Cyprinus carpio, crucian carp Carassius carassius, burbot Lota lota and Balkan loach Cobitis elongata. However, there are also indications that bighead and round goby could adversely impact the native chub Squalius cephalus and zingel Zingel zingel populations, respectively. As P-C gobies are still in the expansionary period of invasion and the ecosystem still adapting to new circumstances, continued monitoring of fish population dynamics in the Sava basin is needed to determine the

  13. Dietary habits of invasive Ponto-Caspian gobies in the Croatian part of the Danube River basin and their potential impact on benthic fish communities.

    PubMed

    Piria, Marina; Jakšić, Goran; Jakovlić, Ivan; Treer, Tomislav

    2016-01-01

    Invasive Ponto-Caspian (P-C(1)) gobies have recently caused dramatic changes in fish assemblage structures throughout the Danube basin. While their presence in the Croatian part of the basin has been noted and distribution studied, their dietary habits and impacts on native fish communities have, until now, been unknown. In 2011, 17 locations in the Sava River Basin were sampled for fish and 15 for benthic invertebrates. Fish population monitoring data, available for nine seasons (2003-2006 and 2010-2014) and 12 locations, were used to analyse the impacts of P-C gobies on benthic fish abundance. Gut content analysis indicates that the monkey goby Neogobius fluviatilis diet is very diverse, but dominated by Trichoptera, Chironomidae, Bivalvia and Odonata. The diet overlaps considerably with the round goby Neogobius melanostomus diet, although Gastropoda are dominant in the latter's diet. Small fish and Gammarus sp. dominate the bighead goby Ponticola kessleri diet. Comparison of gut content with the prey available in the environment indicates that monkey and round gobies exhibit preference for Trichoptera, Megaloptera and Coleoptera, and bighead goby for Trichoptera, Gammarus sp. and Pisces. P-C gobies in the Sava River are spreading upstream, towards the reaches with lower fish diversity. Analyses indicate potentially positive impacts of P-C gobies' presence on some fish populations: round and bighead goby on Balkan golden loach Sabanejewia balcanica and monkey goby on common carp Cyprinus carpio, crucian carp Carassius carassius, burbot Lota lota and Balkan loach Cobitis elongata. However, there are also indications that bighead and round goby could adversely impact the native chub Squalius cephalus and zingel Zingel zingel populations, respectively. As P-C gobies are still in the expansionary period of invasion and the ecosystem still adapting to new circumstances, continued monitoring of fish population dynamics in the Sava basin is needed to determine the

  14. 14th-16th century Danube floods and long-term water-level changes reflected in archaeological-sedimentary evidence - in comparison with documentary evidence

    NASA Astrophysics Data System (ADS)

    Kiss, Andrea; Laszlovszky, József

    2014-05-01

    In the present paper an overview of published and unpublished results of archaeological and sedimentary investigations, predominantly reflect on 14th-16th-century changes, are provided and compared to documentary information on flood events and long-term changes. Long-term changes in flood behaviour and average water-level conditions had long-term detectable impacts on sedimentation and fluvio-morphological processes. Moreover, the available archaeological evidence might also provide information on the reaction of the society, in the form of changes in settlement organisation, building structures and processes. At present, information is mainly available concerning the 16th, and partly to the 14th-15th centuries. Medium and short term evidence mainly corresponds to the main flood peaks or even to single catastrophic flood events. Such processes may be identified in archaeological evidence concerning the second half of the 14th, early 15th centuries; while most of the cases listed above were connected to the flood peak (and/or generally increasing water-level conditions) of the late 15th and early 16th centuries. In other cases connections between sedimentary/archaeological evidence and the mid- and late 16th-century high flood-frequency period were presumed. Documentary evidence referring to the same period suggests that higher flood frequency and intensity periods occurred in the early and mid 16th century; a probably more prolonged flood rich period took place in the second half of the 16th century, with a peak in the late 1560s-early 1570s and maybe with another at the end of the 16th century. Earlier flood peaks in documentary evidence were detected on the Danube at the turn of the 14th-15th centuries and in the last decades of the 15th century, continuing in the early 16th century.

  15. A 320-year long series of Danube floods in Central Hungary (Budapest and Pest County): a frequency-magnitude-seasonality overview

    NASA Astrophysics Data System (ADS)

    Kiss, Andrea; Salinas, Jose; Bloeschl, Guenter

    2015-04-01

    The present paper is based on a recently developed database including contemporary original, administrative, legal and private source materials (published and archival) as well as media reports related to the floods occurred in the town of Budapest (historical towns of Pest, Buda) and Central Hungary (historical Pest-Pilis-Solt County). As for the archival evidence, main bases of investigation are the administrative sources such as town council protocols and county meeting protocols of Budapest and historical Pest-Pilis-Solt County: in these (legal-)administrative documents damaging events (natural/environmental hazards) were systematically recorded. Moreover, other source types such as taxation-related damage accounts as well as private and official reports, letters and correspondence (published, unpublished) were also included. Concerning published evidence, a most important source is flood reports in contemporary newspapers; however, other published sources (e.g. narratives, fund raising circulars etc.; both published and unpublished) also contained useful flood-related information. Beyond providing information on the strength and weaknesses of different sources types and the temporal and spatial distribution of evidence, a general background on the contemporary environmental and hydrological/hydromorphological conditions of the study area (and its changes during and after river regulations) are also provided. However, in the presentation the main focus is on the analysis of flood rich flood poor periods of the last more than 300 years; furthermore, the seasonality distribution as well as the magnitude of Danube flood events - and their spatial differences are discussed. In case of Budapest and Central Hungary, with respect to the greatest flood events, ice jam floods played a rather significant role before river regulation works. Due to this fact the main types of flood events (including their main causes), with special emphasis on ice jam floods, are discussed

  16. An earth systems approach to understanding the tectonic and cultural landscapes of linked marine embayments: Avon-Heathcote Estuary (Ihutai) and Lake Ellesmere (Waihora), New Zealand

    NASA Astrophysics Data System (ADS)

    McFadgen, Bruce G.; Goff, James R.

    2005-03-01

    An earth systems study of the Avon-Heathcote Estuary (Ihutai), New Zealand, shows that tectonic activity has a marked direct and indirect control upon its geomorphology and human settlement in the area. We discuss the Late Holocene history of the embayment in relation to large earthquakes and their after-effects. Of particular note is the rapid fluvial transfer of sand to the coast causing dune formation and a more delayed pulse of coarser sediment causing channel avulsion of the Waimakariri River. While dune system development seems to occur soon after tectonic activity, river channel avulsion, spit/barrier formation and ongoing geomorphological changes may well relate to periods of tectonic activity that occurred 100-200 years previously. The interaction between these two sediment delivery systems causes significant, and often rapid, changes to coastal geomorphology and ecosystems that have serious implications for human populations living at or near the coast. We show a more region-wide picture of the direct and indirect effects of tectonic activity, by comparing two embayments that represent coastal points of entry at opposite ends of the Waimakariri River floodplain: the Avon-Heathcote Estuary (Ihutai) and Lake Ellesmere (Waihora).

  17. Evaluation of the flood-pulse concept based on statistical models of growth of selected fishes of the upper Mississippi River system

    USGS Publications Warehouse

    Gutreuter, S.; Bartels, A.D.; Irons, K.; Sandheinrich, M.B.

    1999-01-01

    The flood-pulse concept (FPC) states that annual inundation is the principal force responsible for productivity and biotic interactions in river-floodplain systems. Somatic growth is one component of production, and we hypothesized that, if the FPC applies, growth of fishes that use the moving littoral zone should differ among years with differing flood pattern, whereas nonlittoral fishes would show no such response. Growth of largemouth bass (Micropterus salmoides) and bluegill (Lepomis macrochirus), species that exploit littoral resources, increased during a year having an unusual warm-season flood in the Upper Mississippi River system and was reduced during low-water years. Growth of white bass (Morone chrysops), which do not rely heavily on the littoral zone, did not differ significantly between the extreme-flood and low-water years. Patterns of growth of black crappie (Pomoxis nigromaculatus), which have intermediate dependence on the moving littoral zone, were somewhat ambiguous. These results are consistent with the hypothesis that the FPC applies, at least under certain conditions, to this temperate river system. Our results can also provide an important basis from which to assess some costs and benefits of water level management strategies in large regulated temperate rivers.

  18. Metazoan endoparasites diversity of Pseudoplatystoma corruscans (Siluriformes: Pimelodidae) as an indicator of environmental alterations on a tropical aquatic system.

    PubMed

    Ribeiro, Thamy S; Lizama, Maria A P; Takemoto, Ricardo M

    2014-09-01

    The aim of the present study was to detect the alterations of Pseudoplatystoma corruscans parasite infracommunity structure, after the construction of the Porto Primavera dam on the high Paraná River floodplain. The execution of this research was based on 119 host specimens collected between March 2011 and September 2012, and the results were compared to studies performed on periods before the reservoir's construction, when 110 fishes were collected between March 1992 and February 1993. Five parasite species still remain on the environment, despite the environmental modifications: Choanoscolex abscissus, Spasskyelina spinulifera, Nomimoscolex pertierrae, Harriscolex kaparari and Contracaecum sp 2. The Berger-Parker dominance index, calculated to the parasite fauna of 1992, did not show the dominance of any species, while, on the present days, this same index accused the dominance of Nomimoscolex pertierrae (49%) and Choanoscolex abscissus (50%). The present study reports the disappearance of Megathylacus travassosi, Contracaecum sp. 1, Contracaecum sp. 3, Procamallanus (Spirocamallanus) sp. and Cucullanus pseudoplatystomae, suggesting the possibility of a local extinction or a host switch of these species. It has also been registered an Acanthocephala specimen, a genus not observed on this host yet. The results here presented show that the antropic influences on natural systems alter the environmental conditions, what is reflected on the richness and diversity parasite levels.

  19. Metazoan endoparasites diversity of Pseudoplatystoma corruscans (Siluriformes: Pimelodidae) as an indicator of environmental alterations on a tropical aquatic system.

    PubMed

    Ribeiro, Thamy S; Lizama, Maria A P; Takemoto, Ricardo M

    2014-09-01

    The aim of the present study was to detect the alterations of Pseudoplatystoma corruscans parasite infracommunity structure, after the construction of the Porto Primavera dam on the high Paraná River floodplain. The execution of this research was based on 119 host specimens collected between March 2011 and September 2012, and the results were compared to studies performed on periods before the reservoir's construction, when 110 fishes were collected between March 1992 and February 1993. Five parasite species still remain on the environment, despite the environmental modifications: Choanoscolex abscissus, Spasskyelina spinulifera, Nomimoscolex pertierrae, Harriscolex kaparari and Contracaecum sp 2. The Berger-Parker dominance index, calculated to the parasite fauna of 1992, did not show the dominance of any species, while, on the present days, this same index accused the dominance of Nomimoscolex pertierrae (49%) and Choanoscolex abscissus (50%). The present study reports the disappearance of Megathylacus travassosi, Contracaecum sp. 1, Contracaecum sp. 3, Procamallanus (Spirocamallanus) sp. and Cucullanus pseudoplatystomae, suggesting the possibility of a local extinction or a host switch of these species. It has also been registered an Acanthocephala specimen, a genus not observed on this host yet. The results here presented show that the antropic influences on natural systems alter the environmental conditions, what is reflected on the richness and diversity parasite levels. PMID:25119352

  20. Using ground based geophysics to evaluate hydrogeologic effects of subsurface drip irrigation systems used to manage produced water in the Powder River Basin, Wyoming

    SciTech Connect

    Sams, J.I.; Lipinski, B.A.; Veloski, G.A.

    2008-04-01

    The U.S Department of Energy’s National Energy Technology Laboratory has been evaluating various geophysical methods for site characterization regarding environmental issues associated with fossil fuels including produced water management. A relatively new method of managing produced water from coal bed natural gas production is through subsurface drip irrigation. This system involves disposing the produced water near the bottom of the root zone in agricultural fields, which would provide a beneficial use of this resource. The focus of this paper is to present results from a pre-injection geophysical survey for site assessment and background data. A pre-construction survey of approximately 1.2 km2 was completed in June 2007 using a Geophex GEM-2 broadband sensor over six fields along the Powder River floodplain. Quality assurance measures included drift checks, duplicate line surveys, and repeat field surveys using the Geometrics OhmMapper instrument. Subsequent surveys will be completed once the system is installed and operational. Geophysical inversion models were completed to provide a detailed cross-section of the subsurface geoelectrical structure along each line. Preliminary interpretations reveal that the subsurface conductivity distribution correlates to geomorphologic features.

  1. OpenDanubia - An integrated, modular simulation system to support regional water resource management

    NASA Astrophysics Data System (ADS)

    Muerth, M.; Waldmann, D.; Heinzeller, C.; Hennicker, R.; Mauser, W.

    2012-04-01

    The already completed, multi-disciplinary research project GLOWA-Danube has developed a regional scale, integrated modeling system, which was successfully applied on the 77,000 km2 Upper Danube basin to investigate the impact of Global Change on both the natural and anthropogenic water cycle. At the end of the last project phase, the integrated modeling system was transferred into the open source project OpenDanubia, which now provides both the core system as well as all major model components to the general public. First, this will enable decision makers from government, business and management to use OpenDanubia as a tool for proactive management of water resources in the context of global change. Secondly, the model framework to support integrated simulations and all simulation models developed for OpenDanubia in the scope of GLOWA-Danube are further available for future developments and research questions. OpenDanubia allows for the investigation of water-related scenarios considering different ecological and economic aspects to support both scientists and policy makers to design policies for sustainable environmental management. OpenDanubia is designed as a framework-based, distributed system. The model system couples spatially distributed physical and socio-economic process during run-time, taking into account their mutual influence. To simulate the potential future impacts of Global Change on agriculture, industrial production, water supply, households and tourism businesses, so-called deep actor models are implemented in OpenDanubia. All important water-related fluxes and storages in the natural environment are implemented in OpenDanubia as spatially explicit, process-based modules. This includes the land surface water and energy balance, dynamic plant water uptake, ground water recharge and flow as well as river routing and reservoirs. Although the complete system is relatively demanding on data requirements and hardware requirements, the modular structure

  2. 2500-year Late Holocene vegetation and hydrologic changes from a cave guano-clay sequence in the Danube Gorge, SW Romania

    NASA Astrophysics Data System (ADS)

    Onac, B. P. P.; Hutchinson, S. M.; Geanta, A.; Forray, F. L.; Wynn, J. G.; Giurgiu, A. M.; Coroiu, I.

    2014-12-01

    This multi-analytical study on a guano/clay sequence in Gaura cu Muscă Cave (GMC), supported by five 14C AMS dates, brings new insights to both vegetation dynamics and paleo-hydroclimate in a region of archeological and anthropological significance. GMC is located at the entrance to the Danube Gorge in SW Romania. The cave is short (254 m), consisting of a main gallery (along which an underground stream flows) that is bypassed by the Bat's Gallery. GMC is a shelter for bats throughout the year and a hibernaculum for five species. Nowadays, the two major guano deposits belong to Myotis capaccinii; one is located underneath the largest colony in the Bat's Chamber, whilst the other one is much smaller and is found in the Bat's Gallery. From this latter location the investigated clay/guano profile was recovered from underneath a blanket of 2 to 3mm thick fresh guano. We provide sedimentological, geochemical, mineral magnetic, guano and charcoal δ13C data, and pollen-based evidence of fluctuating hydro-climate conditions from ~1230 BC to ~AD 1240. Between 1230 BC and AD 1000 the climate was wetter than present prompting the flooding of the cave, preventing bats from roosting and leading to slow-rate clay accumulation. The pollen diagram for this interval confirms a human presence and agriculture activities in the region. The second half of the Medieval Warm Period (MWP; after AD 1000) the climate became drier, which hydrologically translates in the cave being air-filled. At this time a maternity colony existed in the Bat's Gallery, under which guano accumulated. One extremely wet event occurred ~AD 1170, when Fe/Mn and Ti/Zr ratios show the highest values and coincident with a substantial increase of sediment load in the underground stream. The mineral magnetic characteristics for the second part of the MWP indicate partial input of surface-sourced sediments reflecting the agricultural development and forest clearance in the area. Pollen and microcharcoal studies

  3. Floodplain restoration on the upper Danube by re-establishing back water dynamics: first results of the hydro-geomorphological monitoring

    NASA Astrophysics Data System (ADS)

    Fischer, Peter; Hilger, Ludwig; Cyffka, Bernd

    2013-04-01

    Within the framework of a restoration project at the upper Danube, eight working groups of different scientific disciplines have been operating since 2009. They investigate the changes evoked through the accomplished restoration measures, which seek to bring back new dynamics to the floodplain and to reconnect it with the river in order to optimize flood plain ecological functioning. Main object is the identification and analysis of hydro-geomorphological processes and their impact on vegetation and fauna. Hydrology is one of the key factors determining the type and function of flood plains and thus alternating water levels are the motor of riparian ecosystems. Diverse water and groundwater levels and particularly flood events affect and support floodplain typical vegetation and animal species. All floodplain waterbodies (oxbows, floodplain ponds, backwaters and sidearms) are more or less connected by surface or subsurface waterways. Hydrological conditions are mainly influenced by the following measures: a, permanent nature orientated bypass river with a discharge of up to 5 m3/s; b, man controlled ecological flooding (discharge of up to 30 m3/s); c, groundwater drawdown in the eastern project area. These measures shall bring back "former" natural hydrological dynamics to the floodplain. They establish geomorphological processes and forms as well and create a mosaic of typical habitats. River morphology is monitored by terrestrial laser scanning analysing the so attained data sets, erosion and aggregation rates at selected undercut slopes and point bars can be detected with a high resolution. Large scale mapping by a drone and dGPS mapping are very helpful tools for identifing widespread flooding areas. Further methods such as, cross section and bed load measurements complete the research work. The aim is to link the interaction of these abiotic processes with the biotic nature and determine the importance of geomorphological disturbance for floodplain ecosystems

  4. Relative weathering intensity of calcite versus dolomite in carbonate-bearing temperate zone watersheds: Carbonate geochemistry and fluxes from catchments within the St. Lawrence and Danube river basins

    NASA Astrophysics Data System (ADS)

    Szramek, Kathryn; McIntosh, Jennifer C.; Williams, Erika L.; Kanduc, Tjasa; Ogrinc, Nives; Walter, Lynn M.

    2007-04-01

    Calcite and dolomite solubilities in open weathering environments are proportional to pCO2 and inversely proportional to temperature, and dolomite solubility is progressively greater than calcite below 25°C. The continent-scale weathering budget reveals the significance of the Northern Hemisphere (NH) to globally integrated riverine fluxes of Ca2+, Mg2+, and HCO3-. The NH contributes 70% of the global HCO3- flux while only 54% of the riverine discharge. We present results of a comparative hydrogeochemical study of carbonate mineral equilibria and weathering fluxes in two NH carbonate-rich river basins. Surface water geochemistry and discharge were determined for headwater streams in Michigan and Slovenia within the St. Lawrence and Danube river basins. Michigan watersheds are established atop carbonate-bearing glacial drift deposits derived from erosion of Paleozoic strata with thick soil horizons (100-300 cm). Slovenia watersheds drain Mesozoic bedrock carbonates in alpine and dinaric karst environments with thin soil horizons (0-70 cm). Carbonate weathering intensity is a parameter that normalizes river runoff and HCO3- concentration to catchment area (meq HCO3- km-2 s-1), summing calcite and dolomite contributions, and is used to gauge the effects of climate, land use, and soil thickness on organic-inorganic carbon processing rates. Importantly, Michigan riverine discharge is one-tenth of Slovenian rivers, providing the opportunity to evaluate the kinetics of carbonate mineral equilibration. The study rivers are HCO3- - Ca2+ - Mg2+ waters, supersaturated for calcite at pCO2 values in excess of the atmosphere. As discharge varies, HCO3- concentrations differ by less than 20% for any location, and Mg2+/Ca2+ remains relatively fixed for Michigan (0.5) and Slovenia streams (0.4), requiring that dolomite dissolution exceed calcite on a mole basis. The ability of calcite and dolomite dissolution to keep pace with increased discharge indicates carbonate weathering is

  5. RESPONSE OF AVIAN COMMUNITIES IN LARGE-RIVER FLOODPLAINS TO ENVIRONMENTAL VARIATION AT MULTIPLE SCALES. (R826600)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  6. Validity and sensitivity of a model for assessment of impacts of river floodplain reconstruction on protected and endangered species

    SciTech Connect

    Nooij, R.J.W. de . E-mail: R.deNooij@science.ru.nl; Lotterman, K.M.; Sande, P.H.J. van de; Pelsma, T.; Leuven, R.S.E.W.; Lenders, H.J.R.

    2006-11-15

    Environmental Impact Assessment (EIA) must account for legally protected and endangered species. Uncertainties relating to the validity and sensitivity of EIA arise from predictions and valuation of effects on these species. This paper presents a validity and sensitivity analysis of a model (BIO-SAFE) for assessment of impacts of land use changes and physical reconstruction measures on legally protected and endangered river species. The assessment is based on links between species (higher plants, birds, mammals, reptiles and amphibians, butterflies and dragon- and damselflies) and ecotopes (landscape ecological units, e.g., river dune, soft wood alluvial forests), and on value assignment to protected and endangered species using different valuation criteria (i.e., EU Habitats and Birds directive, Conventions of Bern and Bonn and Red Lists). The validity of BIO-SAFE has been tested by comparing predicted effects of landscape changes on the diversity of protected and endangered species with observed changes in biodiversity in five reconstructed floodplains. The sensitivity of BIO-SAFE to value assignment has been analysed using data of a Strategic Environmental Assessment concerning the Spatial Planning Key Decision for reconstruction of the Dutch floodplains of the river Rhine, aimed at flood defence and ecological rehabilitation. The weights given to the valuation criteria for protected and endangered species were varied and the effects on ranking of alternatives were quantified. A statistically significant correlation (p < 0.01) between predicted and observed values for protected and endangered species was found. The sensitivity of the model to value assignment proved to be low. Comparison of five realistic valuation options showed that different rankings of scenarios predominantly occur when valuation criteria are left out of the assessment. Based on these results we conclude that linking species to ecotopes can be used for adequate impact assessments. Quantification of sensitivity of impact assessment to value assignment shows that a model like BIO-SAFE is relatively insensitive to assignment of values to different policy and legislation based criteria. Arbitrariness of the value assignment therefore has a very limited effect on assessment outcomes. However, the decision to include valuation criteria or not is very important.

  7. Diversity and genetic distance in populations of Steindachnerina in the upper Paraná river floodplain of Brazil.

    PubMed

    Oliveira, A V; Prioli, A J; Prioli, S M A P; Pavanelli, C S; Júlio, H F; Panarari, R S

    2002-08-01

    Whereas four species of the genus Steindachnerina occur in the Paraná river basin, S. insculpta was the only endemic species of the region under analysis, which is the third lower section of the upper Paraná river. Among other factors, this species has been characterised by the absence of spots in the basal region of the dorsal fin. However, various specimens with this characteristic appeared in the region after the construction of the Itaipu Hydroelectric Plant in 1982. An analysis of the genetic variability of Steindachnerina populations with or without spots is provided. Specimens were collected in different sites of the floodplain of the upper Paraná river and samples were compared by random amplified polymorphic DNA (RAPD) technique and morphological analyses. Ninety-eight amplified loci with nine random primers were analysed in 19 specimens of each phenotype. Data for genetic distance showed great divergences between the two phenotypes and indicate two different species. Spotted specimens may be identified as S. brevipinna, found in the region downstream Sete Quedas Falls. The species must have overcome the geographical barrier during the building of the Itaipu hydroelectric dam that submerged the waterfalls and which became an obstacle between the upper and middle Paraná river some 150 km downstream. Since phenotypes do not share dominant alleles, absence of gene flow has been suggested. PMID:12440565

  8. Use of satellite image analysis to track wetland loss on the Murrumbidgee River floodplain in arid Australia, 1975-1998.

    PubMed

    Kingsford, R T; Thomas, R F

    2002-01-01

    Demonstrating the extent of wetland loss and its causes are essential for policy makers and managers. We used Landsat satellite imagery to show major wetland loss in the Lower Murrumbidgee floodplain on the Murrumbidgee River in arid Australia. Stratification of the floodplain according to hydrology, use of imagery from the same time of year and the separation of developed areas, using ancillary information were essential. There was considerable loss of floodplain area over a 23 year period (1975-1998), mainly in the Nimmie-Caira stratum (59% loss), as wetland areas were replaced by irrigation bays. There was also a significant increase in fragmentation. For floodplain areas distant from the river, flooding patterns were more difficult to identify because of infrequent flooding and primary reliance on rainfall. Landsat imagery provided a powerful tool for demonstrating long-term changes in wetland area, even in highly variable environments. Such information can demonstrate the ecological costs of water resource development on floodplains, forming a basis for policy and management of rivers.

  9. Environmental education in the Upper Paraná River floodplain, municipality of Porto Rico (Paraná State), Brazil.

    PubMed

    Obara, A T; Suzuki, H I; Takemoto, R M; Tomanik, A; Corredato-Periotto, T R; Silva-Dias, M A G

    2009-06-01

    Since 2003, researchers, faculty, graduate and undergraduate students from the State University of Maringá have been working alongside teachers from the state and local schools in the municipality of Porto Rico (Paraná State), located on the banks of the Paraná River. Their objective is to outline actions and strategies with the purpose of building methodological paths to insert environmental education into the school curriculum. Based on the action-research methodology, the group has developed the following programs: a) the Continuing Education Program in Environmental Education; b) the Development of Interdisciplinary Projects; c) the Insertion of Information and Communication Technologies (ICTs); and d) the Production of Teaching Materials. The evaluations of the programs indicate that teachers have been able to gradually build a theoretical and methodological basis for environmental education while simultaneously growing into the role of teacher-researchers as they create the conditions to investigate their pedagogical practices, reflect upon them, share experiences, innovate, and make the teaching-learning process more significant. Allied to the advances in educational practices and with the aid of ICTs, the activities developed in the classroom, in the field and in the lab--all of which involve natural and cultural aspects of the region--have contributed to teachers' and students' better understanding of the ecological, cultural, social and economic value of the floodplain, and consequently, of the importance of preservation and management in order to maintain local biodiversity.

  10. Influence of deposition of fine plant debris in river floodplain shrubs on flood flow conditions - The Warta River case study

    NASA Astrophysics Data System (ADS)

    Mazur, Robert; Kałuża, Tomasz; Chmist, Joanna; Walczak, Natalia; Laks, Ireneusz; Strzeliński, Paweł

    2016-08-01

    This paper presents problems caused by organic material transported by flowing water. This material is usually referred to as plant debris or organic debris. Its composition depends on the characteristic of the watercourse. For lowland rivers, the share of the so-called small organic matter in plant debris is considerable. This includes both various parts of water plants and floodplain vegetation (leaves, stems, blades of grass, twigs, etc.). During floods, larger woody debris poses a significant risk to bridges or other water engineering structures. It may cause river jams and may lead to damming of the flowing water. This, in turn, affects flood safety and increases flood risk in river valleys, both directly and indirectly. The importance of fine plant debris for the phenomenon being studied comes down to the hydrodynamic aspect (plant elements carried by water end up on trees and shrubs, increase hydraulic flow resistance and contribute to the nature of flow through vegetated areas changed from micro-to macro-structural). The key part of the research problem under analysis was to determine qualitative and quantitative debris parameters and to establish the relationship between the type of debris and the type of land use of river valleys (crop fields, meadows and forested river sections). Another problem was to identify parameters of plant debris for various flow conditions (e.g. for low, medium and flood flows). The research also included an analysis of the materials deposited on the structure of shrubs under flood flow conditions during the 2010 flood on the Warta River.

  11. Patterns of food resource use by two congeneric species of piranhas (Serrasalmus) on the Upper Paraná River floodplain.

    PubMed

    Agostinho, C S; Hahn, N S; Marques, E E

    2003-05-01

    Serrasalmus marginatus invaded the Upper Paraná River after construction of the Itaipu Dam in November 1982. This was followed by a reduction in abundance of the native species S. spilopleura. Analysis of the pattern of food resource use revealed that both species employ the same feeding strategy, eating mainly fish (whole fish or muscle fragments) and fins bitten off their prey. The diurnal activity period and the feeding rhythm were better-defined in S. marginatus. For young individuals of both species, food was taken in a significantly discontinuous manner (F = 2.83; p < 0.05 and F = 13.25; p < 0.05), with a peak at 4 p.m. Ontogenetic differences in diet, the strong feeding overlap of larger individuals of S. marginatus and smaller individuals of S. spilopleura, and the aggressiveness of S. marginatus in establishing feeding territories may have contributed to the success of the invading species.

  12. Diversity and genetic distance in populations of Steindachnerina in the upper Paraná river floodplain of Brazil.

    PubMed

    Oliveira, A V; Prioli, A J; Prioli, S M A P; Pavanelli, C S; Júlio, H F; Panarari, R S

    2002-08-01

    Whereas four species of the genus Steindachnerina occur in the Paraná river basin, S. insculpta was the only endemic species of the region under analysis, which is the third lower section of the upper Paraná river. Among other factors, this species has been characterised by the absence of spots in the basal region of the dorsal fin. However, various specimens with this characteristic appeared in the region after the construction of the Itaipu Hydroelectric Plant in 1982. An analysis of the genetic variability of Steindachnerina populations with or without spots is provided. Specimens were collected in different sites of the floodplain of the upper Paraná river and samples were compared by random amplified polymorphic DNA (RAPD) technique and morphological analyses. Ninety-eight amplified loci with nine random primers were analysed in 19 specimens of each phenotype. Data for genetic distance showed great divergences between the two phenotypes and indicate two different species. Spotted specimens may be identified as S. brevipinna, found in the region downstream Sete Quedas Falls. The species must have overcome the geographical barrier during the building of the Itaipu hydroelectric dam that submerged the waterfalls and which became an obstacle between the upper and middle Paraná river some 150 km downstream. Since phenotypes do not share dominant alleles, absence of gene flow has been suggested.

  13. Economic analysis of temperature reduction in a large river floodplain: An exploratory study of the WIllamette River, Oregon

    EPA Science Inventory

    This paper examines ecosystem restoration practices that focus on water temperature reductions in the upper mainstem Willamette River, Oregon, for the benefit of endangered salmonids and other native cold-water species. The analysis integrates hydrologic, natural science and eco...

  14. The spatial and temporal trends of Cd, Cu, Hg, Pb and Zn in Seine River floodplain deposits (1994-2000)

    USGS Publications Warehouse

    Grosbois, C.; Meybeck, Michel; Horowitz, A.; Ficht, A.

    2006-01-01

    Fresh floodplain deposits (FD), from 11 key stations, covering the Seine mainstem and its major tributaries (Yonne, Marne and Oise Rivers), were sampled from 1994 to 2000. Background levels for Cd, Cu, Hg, Pb, and Zn were established using prehistoric FD and actual bed sediments collected in small forested sub-basins in the most upstream part of the basin. Throughout the Seine River Basin, FD contain elevated concentrations of Cd, Cu, Hg, Pb and Zn compared to local background values (by factors > twofold). In the Seine River Basin, trace element concentrations display substantial downstream increases as a result of increasing population densities, particularly from Greater Paris (10 million inhabitants), and reach their maxima at the river mouth (Poses). These elevated levels make the Seine one of the most heavily impacted rivers in the world. On the other hand, floodplain-associated trace element levels have declined over the past 7 years. This mirrors results from contemporaneous suspended sediment surveys at the river mouth for the 1984-1999 period. Most of these temporal declines appear to reflect reductions in industrial and domestic solid wastes discharged from the main Parisian sewage plant (Seine Aval). ?? 2005 Elsevier B.V. All rights reserved.

  15. Dissolved organic carbon lability increases with water residence time in the alluvial aquifer of a river floodplain ecosystem

    NASA Astrophysics Data System (ADS)

    Helton, Ashley M.; Wright, Meredith S.; Bernhardt, Emily S.; Poole, Geoffrey C.; Cory, Rose M.; Stanford, Jack A.

    2015-04-01

    We assessed spatial and temporal patterns of dissolved organic carbon (DOC) lability and composition throughout the alluvial aquifer of the 16 km2 Nyack Floodplain in northwest Montana, USA. Water influx to the aquifer derives almost exclusively from the Middle Fork of the Flathead River, and water residence times within the aquifer range from days to months. Across seasons and channel discharge conditions, we measured DOC concentration, lability, and optical properties of aquifer water sampled from 12 wells, both near and ~3 m below the water table. Concentrations of DOC were typically low (542 ± 22.7 µg L-1; mean ± se), and the percentage of labile DOC averaged 18 ± 12% during 3 day laboratory assays. Parallel factor analysis of fluorescence excitation-emission matrices revealed two humic-like and two amino acid-like fluorescence groups. Total DOC, humic-like components, and specific UV absorbance decreased with water residence time, consistent with sorption to aquifer sediments. However, labile DOC (both concentration and fraction) increased with water residence time, suggesting a concurrent influx or production of labile DOC. Thus, although the carbon-poor, oxygen-rich aquifer is a net sink for DOC, recalcitrant DOC appears to be replaced with more labile DOC along aquifer flow paths. Our observation of DOC production in long flow paths contrasts with studies of hyporheic DOC consumption along short (centimeters to meters) flow paths and highlights the importance of understanding the role of labile organic matter production and/or influx in alluvial aquifer carbon cycling.

  16. Ecology of endoparasites of the fluvial stingray Potamotrygon falkneri (Chondrichthyes: Potamotrygonidae) from the upper Paraná River floodplain, Brazil.

    PubMed

    Lacerda, A C F; Takemoto, R M; Pavanelli, G C

    2009-05-01

    The present study investigated the ecological relationships between endoparasites and the host Potamotrygon falkneri from the upper Paraná River by using as indicators the host's relative condition factor (Kn), sex and hepatosomatic relation (HSR). Forty-seven specimens of P. falkneri were analyzed between March 2005 and September 2006. Statistical analysis showed that the Kn was positively correlated with the abundance of Acanthobothrium regoi and Rhinebothrium paratrygoni; only the abundance of A. regoi was positively correlated to the HSR, whereas R. paratrygoni did not present correlation and there was no influence of the host's sex on the abundance and prevalence of parasites. This is the first study concerning the ecology of parasites of potamotrygonids. PMID:19675930

  17. Threshold effects of flood duration on the vegetation and soils of the Upper Mississippi River floodplain, USA

    USGS Publications Warehouse

    De Jager, Nathan R.; Thomsen, Meredith; Yin, Yao

    2012-01-01

    Our results suggest that there is a threshold along the elevation gradient of this floodplain, corresponding with flood durations lasting ~40% of the growing season. At lower elevation sites, flooding exerts primary control over forest soils and vegetation, restricting the former to silt plus clay with higher organic matter and the latter to a few highly flood tolerant species. The existence of such thresholds have implications for management of floodplain soil nutrient dynamics and plant diversity under existing hydrologic regimes, more natural hydrologic regimes and more extreme hydrologic regimes that may result from climate change.

  18. Great horned owl (Bubo virginianus) dietary exposure to PCDD/DF in the Tittabawassee River floodplain in Midland, Michigan, USA.

    PubMed

    Coefield, Sarah J; Zwiernik, Matthew J; Fredricks, Timothy B; Seston, Rita M; Nadeau, Michael W; Tazelaar, Dustin L; Moore, Jeremy N; Kay, Denise P; Roark, Shaun A; Giesy, John P

    2010-10-01

    Soils and sediments in the floodplain of the Tittabawassee River downstream of Midland, Michigan, USA contain elevated concentrations of polychlorinated dibenzofurans (PCDF) and polychlorinated dibenzo-p-dioxins (PCDD). As a long-lived, resident top predator, the great horned owl (Bubo virginianus; GHO) has the potential to be exposed to bioaccumulative compounds such as PCDD/DF. Site-specific components of the GHO diet were collected along 115 km of the Tittabawassee, Pine, Chippewa, and Saginaw Rivers during 2005 and 2006. The site-specific GHO biomass-based diet was dominated by cottontail rabbits (Sylvilagus floridanus) and muskrats (Ondatra zibethicus). Incidental soil ingestion and cottontail rabbits were the primary contributors of PCDD/DF to the GHO diet. The great horned owl daily dietary exposure estimates were greater in the study area (SA) (3.3 to 5.0 ng 2,3,7,8-TCDD equivalents (TEQ(WHO-avian))/kg body wt/d) than the reference area (RA) (0.07 ng TEQ(WHO-Avian)/kg body wt/d). Hazard quotients (HQs) based on central tendency estimates of the average daily dose and no-observable-adverse effect level (NOAEL) for the screech owl and uncertainty factors were <1.0 for both the RA and the SA. Hazard quotients based on upper end estimates of the average daily dose and NOAEL were <1.0 in the RA and up to 3.4 in the SA. PMID:20872700

  19. Control of reed canarygrass promotes wetland herb and tree seedling establishment in an upper Mississippi River Floodplain forest

    USGS Publications Warehouse

    Thomsen, Meredith; Brownell, Kurt; Groshek, Matthew; Kirsch, Eileen

    2012-01-01

    Phalaris arundinacea (reed canarygrass) is recognized as a problematic invader of North American marshes, decreasing biodiversity and persisting in the face of control efforts. Less is known about its ecology or management in forested wetlands, providing an opportunity to apply information about factors critical to an invader's control in one wetland type to another. In a potted plant experiment and in the field, we documented strong competitive effects of reed canarygrass on the establishment and early growth of tree seedlings. In the field, we demonstrated the effectiveness of a novel restoration strategy, combining site scarification with late fall applications of pre-emergent herbicides. Treatments delayed reed canarygrass emergence the following spring, creating a window of opportunity for the early growth of native plants in the absence of competition from the grass. They also allowed for follow-up herbicide treatments during the growing season. We documented greater establishment of wetland herbs and tree seedlings in treated areas. Data from small exclosures suggest, however, that deer browsing can limit tree seedling height growth in floodplain restorations. Slower tree growth will delay canopy closure, potentially allowing reed canarygrass re-invasion. Thus, it may be necessary to protect tree seedlings from herbivory to assure forest regeneration.

  20. Geomorphic and hydrologic assessment of erosion hazards at the Norman municipal landfill, Canadian River floodplain, Central Oklahoma

    USGS Publications Warehouse

    Curtis, J.A.; Whitney, J.W.

    2003-01-01

    The Norman, Oklahoma, municipal landfill closed in 1985 after 63 years of operation, because it was identified as a point source of hazardous leachate composed of organic and inorganic compounds. The landfill is located on the floodplain of the Canadian River, a sand-bed river characterized by erodible channel boundaries and by large variation in mean monthly discharges. In 1986, floodwaters eroded riprap protection at the southern end of the landfill and penetrated the landfill's clay cap, thereby exposing the landfill contents. The impact of this moderate-magnitude flood event (Q12) was the catalyst to investigate erosion hazards at the Norman landfill. This geomorphic investigation analyzed floodplain geomorphology and historical channel changes, flood-frequency distributions, an erosion threshold, the geomorphic effectiveness of discharge events, and other factors that influence erosion hazards at the landfill site. The erosion hazard at the Norman landfill is a function of the location of the landfill with respect to the channel thalweg, erosional resistance of the channel margins, magnitude and duration of discrete discharge events, channel form and hydraulic geometry, and cumulative effects related to a series of discharge events. Based on current climatic conditions and historical channel changes, a minimum erosion threshold is set at bankfull discharge (Q = 572 m3/s). The annual probability of exceeding this threshold is 0.53. In addition, this analysis indicates that peak stream power is less informative than total energy expenditures when estimating the erosion potential or geomorphic effectiveness of discrete discharge events. On the Canadian River, long-duration, moderate-magnitude floods can have larger total energy expenditures than shorter-duration, high-magnitude floods and therefore represent the most serious erosion hazard to floodplain structures.

  1. The loess-paleosol profile Datthausen, on the penultimate-glacial terrace of the upper Danube River: Sedimentological and paleopedological characteristics

    NASA Astrophysics Data System (ADS)

    Sauer, Daniela; Kadereit, Annette; Kühn, Peter; Herrmann, Ludger; Kösel, Michael; Miller, Christopher; Shinonaga, Taeko; Kreutzer, Sebastian; Starkovich, Britt

    2015-04-01

    Here we present a new loess profile, exposed in the gravel quarry Datthausen on the penultimate-glacial terrace of the upper Danube River, 40 km SW of Ulm, Germany. The loess in this region is by far not as thick and differentiated as in the Upper and Middle Rhine regions or in the Basin of Mainz; nevertheless, we found several similarities between those and the profile Datthausen. The profile is located in the East wall of the quarry, in a flat channel filled by reworked loess. It was sampled for grain size analysis, chemical standard analyses, analysis of the clay mineral assemblage (XRD of oriented clay specimen) and soil thin section analysis. Five luminescence dates provide a time frame (see Kadereit et al. in this session for further details). The profile starts above the Eemian paleosol, which is developed in penultimate-glacial gravel of the Danube River. No early Würmian soils are preserved; the basal section of the profile comprises a succession of several middle Würmian (MIS3) brown soil horizons (9BCr to 6Bg5; Table 1). Two additional brown horizons (5Bg4 and 5Bg3) follow on top. They both have a slight olive tint, and the upper one shows clear features of redox processes and reworking. A thin gravel band on top of the olive-brown soil horizons can be traced over ca. 170 m along the wall (4Bg2). Above the gravel band two brown, only slightly de-carbonated soil horizons (3Bw1 and 2Bg1) and two hydromorphic horizons (Cg2 and Cg1) follow. The top of the profile is made up of a Luvisol comprising the horizon sequence Ap-Bt-BCtg1-BCtg2. Table 1: Main soil-morphological characteristics of the loess-paleosol profile Datthausen Depth; horizon (FAO); color (dry, moist); structure; major characteristics -30 cm: Ap -70 cm: Bt; 10YR5/6, 10YR4/6; angular blocky and prismatic; earthworm feces, channels, clay coatings -100 cm: BCtg1; 10YR7/4, 10YR5/4; massive, pinholes; mottled, fine Mn nodules, clay coatings in channels -125 cm: BCtg2; 10YR6/4, 10YR4/4; massive

  2. Ontogenetic variations in the diet of two invasive gobies, Neogobius melanostomus (Pallas, 1814) and Ponticola kessleri (Günther, 1861), from the middle Danube (Slovakia) with notice on their potential impact on benthic invertebrate communities.

    PubMed

    Števove, Barbora; Kováč, Vladimír

    2016-07-01

    In this study, ontogenetic variations in diet of invasive bighead goby Ponticola kessleri and round goby Neogobius melanostomus from the middle Danube were analysed. Index of stomach fullness, Fulton's condition factor, index of food importance, frequency of occurrence, biomass, electivity, and proportions of invasive organisms in their diet were examined. Changes in the diet during ontogeny of both species emphasise the differences in their trophic niches. Our results combined with literary data suggest that bighead goby may threaten small native benthic fish species as a predator (especially in the invasion front), whereas round goby can potentially impact native fish species of all ontogenetic phases by competing for food. Round goby appear to have strong impact on bivalves, especially in the invasion front. High consumption of invasive organisms by bighead goby may help the native macroinvertebrate community. Thus, in contrast to round goby, bighead goby does not seem to be a hot candidate for being a nuisance invader.

  3. Distribution and accumulation of elements (As, Cu, Fe, Hg, Mn, and Zn) in tissues of fish species from different trophic levels in the Danube River at the confluence with the Sava River (Serbia).

    PubMed

    Subotić, S; Višnjić Jeftić, Ž; Spasić, S; Hegediš, A; Krpo-Ćetković, J; Lenhardt, M

    2013-08-01

    Pikeperch (Sander lucioperca), European catfish (Silurus glanis), common carp (Cyprinus carpio), and gobies (Neogobius gymnotrachelus, Neogobius melanostomus) were collected from the Danube River (Belgrade section), and samples of liver, muscle, or whole-body composites (in the case of gobies) were analyzed for As, Cu, Fe, Hg, Mn, and Zn with inductively coupled plasma optical spectrometry to find out if there was a correlation between accumulation of these elements in predatory and prey species, as well as in pairs of species with overlapping diets. Concentrations of all analyzed elements were either higher (Cu, Fe, Mn, Zn) in liver than in muscle, or equal (As, Hg), except for Hg in carp, which was higher in muscle. Mercury concentration in liver and muscle of predators (catfish, pikeperch) was significantly (<10(-4)) higher than in prey fishes (carp and gobies). The results indicate that Hg concentration was biomagnified through the food chain. Concentrations of As, Fe, and Hg in carp liver and gobies whole-body composite were similar, but carp had significantly (<10(-4)) higher values of Zn and Cu in liver. The regression analysis and trendline equations indicate that the concentrations of all tested elements, except for As in liver, and Mn and Fe in muscle, were similar in predatory fish (pikeperch and catfish), on one hand, and in prey fish (carp and gobies), on the other hand. Distinctly high Zn concentration in carp is very common in this species due to its physiology. Concentrations of Hg and Zn were higher than the maximum acceptable concentration due to the high pollution level in this section of the Danube River, accordingly posing a risk for the human consumption of these fish species.

  4. The loess-paleosol profile Datthausen, on the penultimate-glacial terrace of the upper Danube River: Luminescence dating and interpretation

    NASA Astrophysics Data System (ADS)

    Kadereit, Annette; Sauer, Daniela; Kühn, Peter; Herrmann, Ludger; Kösel, Michael; Miller, Christopher; Shinonaga, Taeko; Kreutzer, Sebastian; Starkovich, Britt

    2015-04-01

    The loess-paleosol profile Datthausen is situated on the penultimate-glacial (Würmian) terrace of the upper Danube River in southern Germany. The sequence of reworked, mostly sandy loess deposits exhibits brownish, loamy paleosols in its lower part and slightly de-carbonated and hydromorphic horizons in its upper part. The stratigraphic bisection is interpreted as the transition from the terrestrial Middle Pleniglacial (Middle Würmian) to the Upper Pleniglacial (Upper Würmian). This interpretation is supported by the observation that the upper two of the loamy paleosols show an olive tint and features of sediment reworking at the top (see Sauer et al. in this session). A similar stratigraphic pattern was observed in other central European loess-paleosol sections (Schönhals et al. 1964, E&G 15: 199-206) and was recently corroborated for, e.g., Nussloch on the Upper Rhine and Schwalbenberg II on the Middle Rhine (Antoine et al. 2009, QSR 28: 2955-2973; Schirmer 2012, E&G 61: 32-47). However, the chronometric position of the terrestrial Middle Pleniglacial to Upper Pleniglacial (MPG/UPG) transition is still under debate, as are the palaeoclimatic triggers controlling loess and soil formation. Valuable information hereon may be gained by matching the terrestrial chronologies with the marine and Greenland ice-core records. The chronometry of the Datthausen section is based on blue-light stimulated luminescence (BLSL) dating of small aliquots (ca. 200-500 grains) of quartz coarse grains (125-212 µm), using a single-aliquot regeneration (SAR) protocol (Murray & Wintle 2000, Rad. Meas. 32: 57-73) and a minimum-age model (Galbraith et al. 1999, Archaeometry 41: 339-364). Formation of the paleosols was likely promoted during the warmer Greenland Interstadials (GIS). Luminescence dating on samples taken from these paleosols determines the time of sediment deposition that preceded the soil formation in the respective sediment. We sampled two horizons below and three

  5. Constructing ribosomes along the Danube

    PubMed Central

    Warner, Jonathan R.

    2010-01-01

    The EMBO Conference on Ribosome Synthesis held last summer explored the latest breakthroughs in ribosome assembly and how it affects disease. Both of these topics have recently seen important advances that enlighten how almost 200 proteins cooperate to produce a ribosome and how the cell responds to a malfunction in this process. PMID:20010797

  6. Quantifying biogeochemical responses to hydrological perturbations in terrestrial systems using geophysical monitoring and inversion schemes

    NASA Astrophysics Data System (ADS)

    Hubbard, S. S.; Dafflon, B.; Tran, A. P.; Chen, J.; Wainwright, H. M.

    2015-12-01

    Although recognized that terrestrial hydrological processes drive a variety of biogeochemical processes, quantifying interactions that occur across a range of scales and compartments is challenging. We describe recently developed approaches to quantify these interactions, and demonstrate the value of developed approaches in two different terrestrial systems. The first is a relatively flat Arctic tundra polygonal ground system, where snowmelt-dominated, surface water distribution significantly influences soil microbial activity and resulting production of greenhouse gasses. The second is a Colorado River floodplain-catchment, where a transient snowmelt pulse leads to hydrological and biogeochemical interactions between different compartents of the system. Three capabilties were developed to improve understanding of hydrology influences on biogeochemistry at these sites. The first is a networked sensing system that coincidently measures below-, at- and above-ground critical properties (such as soil moisture, soil temperature, canopy greenness, surface water inundation, active layer depth, and snow thickness). The approach takes advantage of autonomous data acquisition using unmanned aerial vehicles, tram-based sensors, and surface geophysical approaches. The dense datasets enable 'visualization' of interactions that occur across compartments in response to freeze-thaw and runoff processes. The second advance is the development of a coupled hydro-thermal-geophysical inversion scheme that takes advantage of spatially extensive geophysical data as well as direct but sparse measurements in the quantitative estimation of terrestrial responses to hydrological perturbations. The third is the development of stochastic 'zonation' approaches, which use multi-type, multi-scale datasets to identify regions in the landscape that have unique distributions of properties that influence biogeochemical cycling. Together, the sensing, modeling, and integrative functional zonation

  7. Landscape ecology of the Upper Mississippi River System: Lessons learned, challenges and opportunities

    USGS Publications Warehouse

    DeJager, Nathan R.

    2016-03-22

    The Upper Mississippi River System (UMRS) is a mosaic of river channels, backwater lakes, floodplain forests, and emergent marshes. This complex mosaic supports diverse aquatic and terrestrial plant communities, over 150 fish species; 40 freshwater mussel species; 50 amphibian and reptile species; and over 360 bird species, many of which use the UMRS as a critical migratory route. The river and floodplain are also hotspots for biogeochemical activity as the river-floodplain collects and processes nutrients derived from the UMR basin. These features qualify the UMRS as a Ramsar wetland of international significance.Two centuries of land-use change, including construction for navigation and conversion of large areas to agriculture, has altered the broad-scale structure of the river and changed local environmental conditions in many areas. Such changes have affected rates of nutrient processing and transport, as well as the abundance of various fish, mussel, plant, and bird species. However, the magnitude and spatial scale of these effects are not well quantified, especially in regards to the best methods and locations for restoring various aspects of the river ecosystem.The U.S. Congress declared the navigable portions of the Upper Mississippi River System (UMRS) a “nationally significant ecosystem and nationally significant commercial navigation system” in the Water Resources Development Act of 1986 (Public Law 99-662) and launched the Upper Mississippi River Restoration (UMRR) Program, the first comprehensive program for ecosystem restoration, monitoring, and research on a large river system. This fact sheet focuses on landscape ecological studies conducted by the U.S. Geological Survey to support decision making by the UMRR with respect to ecosystem restoration.

  8. Landscape ecology of the Upper Mississippi River System: Lessons learned, challenges and opportunities

    USGS Publications Warehouse

    DeJager, Nathan R.

    2016-01-01

    The Upper Mississippi River System (UMRS) is a mosaic of river channels, backwater lakes, floodplain forests, and emergent marshes. This complex mosaic supports diverse aquatic and terrestrial plant communities, over 150 fish species; 40 freshwater mussel species; 50 amphibian and reptile species; and over 360 bird species, many of which use the UMRS as a critical migratory route. The river and floodplain are also hotspots for biogeochemical activity as the river-floodplain collects and processes nutrients derived from the UMR basin. These features qualify the UMRS as a Ramsar wetland of international significance.Two centuries of land-use change, including construction for navigation and conversion of large areas to agriculture, has altered the broad-scale structure of the river and changed local environmental conditions in many areas. Such changes have affected rates of nutrient processing and transport, as well as the abundance of various fish, mussel, plant, and bird species. However, the magnitude and spatial scale of these effects are not well quantified, especially in regards to the best methods and locations for restoring various aspects of the river ecosystem.The U.S. Congress declared the navigable portions of the Upper Mississippi River System (UMRS) a “nationally significant ecosystem and nationally significant commercial navigation system” in the Water Resources Development Act of 1986 (Public Law 99-662) and launched the Upper Mississippi River Restoration (UMRR) Program, the first comprehensive program for ecosystem restoration, monitoring, and research on a large river system. This fact sheet focuses on landscape ecological studies conducted by the U.S. Geological Survey to support decision making by the UMRR with respect to ecosystem restoration.

  9. The evolution of an asymmetric deltaic lobe (Sf. Gheorghe, Danube) in association with cyclic development of the river-mouth bar: Long-term pattern and present adaptations to human-induced sediment depletion

    NASA Astrophysics Data System (ADS)

    Preoteasa, Luminiţa; Vespremeanu-Stroe, Alfred; Tătui, Florin; Zăinescu, Florin; Timar-Gabor, Alida; Cîrdan, Ionela

    2016-01-01

    The asymmetric Sf. Gheorghe lobe is the only active lobe in the Danube delta associated with a river-mouth bar (and related barrier islands and spits) that has continuously displayed cyclic development during the last 1500 years. During the early cycles, the Sf. Gheorghe distributary experienced a significant increase in sediment load (by an order of magnitude) as a result of the successive avulsions occurred 1.5-1.2 ka, which redistributed more water and sediment captured from the neighboring branches of Împuţita (southern distributary of the Sulina arm) and Dunavăţ. Morphological and sedimentological analyses together with a newly obtained chronology throw light on the multiple ridgeset (10) structure of Sf. Gheorghe lobe, each of them (excepting the first one) following a common evolutionary pattern reflected by the cyclic succession of the recurring stages: i) subaqueous mouth bar building, ii) barrier island emergence, and iii) transformation into a barrier spit with several secondary spits. The spits become encased into the muddy deltaic plain as narrow sandy ridges building out on the downdrift side of the lobe as a barrier-marsh plain, whereas the updrift side constantly accreted fed by longshore currents, forming a classic beach ridge plain. The size of each ridgeset increased exponentially with every new cycle due to the constant lengthening of the coastline as the downdrift side of the lobe advanced seaward through a series of progressively larger similar quadrilaterals, yielding a corresponding geometric progression of the delta front size. Even though each newly formed ridgeset (cycle) had a longer lifespan (the latest cycles lasting 4-5 times longer than the first ones: 200-440 years versus 50-80 years), the evolutionary model remained unchanged as long as the balance between wave- and river-borne sediments, defined by the sedimentary index (Si), remained constantly low (Si ≤ 0.1), whereas the mean advance rates of the river mouth remained

  10. The evolution of the Sf. Gheorghe (Danube) asymmetric deltaic lobe in association with the cyclic development of a river-mouth bar and present adaptations to human-induced sediment depletion

    NASA Astrophysics Data System (ADS)

    Vespremeanu-Stroe, Alfred; Preoteasa, Luminita; Tatui, Florin; Zainescu, Florin; Timar-Gabor, Alida; Cardan, Ionela

    2015-04-01

    The asymmetric Sf. Gheorghe lobe is the only active lobe in the Danube delta associated with a river mouth bar (and related barrier islands and spits) that has continuously deployed a cyclic development during the last 1500 years. During the early cycles, Sf. Gheorghe distributary experienced a significant increase in sediment load (by an order of magnitude) as a result of the successive avulsions of the neighboring branches Împuţita (southern distributary of the Sulina arm) and Dunavăţ (1.5 - 1.2 ka ago). Morphological and sedimentological analyses together with a newly obtained chronology throw light on the multiple ridgeset (10) structure of Sf. Gheorghe deltaic lobe, each ridgeset closely following a common evolutionary pattern reflected by the cyclic succession of the same stages: i) subaqueous mouth bar building, ii) barrier island emergence, iii) transformation into a barrier spit with several secondary spits. The spits become encased into the muddy deltaic plain as narrow sandy ridges building out on the downdrift side of the lobe as a barrier-marsh plain, whereas the updrift side constantly accreted fed by longshore currents, forming a classic beach ridge plain. The size of each ridgeset increased exponentially with every new cycle due to the constant lengthening of the coastline as the downdrift side of the lobe advanced seaward through a series of progressively larger similar quadrilaterals, yielding a geometric progression of the delta front size. Even though each newly formed ridgeset (cycle) had a longer lifespan (the latest cycles lasting 4 - 5 times longer than the first ones: 280 - 380 years versus 50 - 80 years), the evolutionary model remained unchanged as long as the balance between wave- and river-borne sediments, defined by the sedimentary index (Si), maintained constantly low (Si ≤ 0.1), whereas the mean advancing rates of the river mouth remained constant at 10 m/yr. Abrupt changes occurred within the last cycle (since the beginning of

  11. Seasonal Variation of the Cryopsheric Systems on the Alaskan Arctic Coast From InSAR Analysis Using Ice-phase ERS-2 Data

    NASA Astrophysics Data System (ADS)

    Liu, L.; Zebker, H. A.

    2012-12-01

    We apply Interferometric Synthetic Aperture Radar (InSAR) analysis to monitor seasonal deformation over the Arctic-coastal Alaska cryosphere region continuously from winter to summer. From March through July 2011, the last few months of the European Space Agency's ERS-2 mission, the satellite was maneuvered into a 'Ice Phase' campaign with a three day repeat orbit. This much shorter revisit period, compared to the usual 35 day interval, greatly reduces the temporal decorrelation that hinders InSAR applications. On the other hand, earlier failure of the on-board gyroscope limits InSAR usefulness due to significant spatial and temporal variations of radar Doppler frequencies. Here we compensate for this system problem by modeling the Doppler centroid as a quadratic function of the radar range to estimate and track any Doppler ambiguity, so that we are able to produce a set of interferograms over the ice phase period. The winter interferograms alone clearly show fast processes such as motion of the Beaufort sea ice and lake ice covering the thaw lakes. The spring interferograms reveal detailed, cm-level changes in the area and elevation over the Kuparuk and Sagavanirktok River floodplains and the delta plains near Prudhoe Bay. These changes are associated with snow melting and sea ice break-up. Comparisons between the winter and the summer interferograms reveal dramatic seasonal variations on the tundra landscape. Our study promises to enable a wide range of new InSAR applications in cryospheric sciences using the C-band SAR data acquired by the Sentinel-1 mission due to launch in 2013. The Sentinel-1 twin satellites are expected to provide coverage over Europe and North America every 1-3 days. Two 3-day interferograms showing distinct InSAR phases and amplitudes on the Arctic coast of Alaska.

  12. Green Island and the Hyporheic Zone: Why Restoration matters

    EPA Science Inventory

    Large river floodplains present diverse benefits to communities, yet management strategies often fail to consider the broad suite of ecosystem services provided by these systems. The U.S. Environmental Protection Agency (EPA) is evaluating the benefits associated with restoring l...

  13. CHANGES IN LOWLAND FLOODPLAIN SEDIMENTATION PROCESSES: PRE-DISTURBANCE TO POST-REHABILITATION, COSUMNES RIVER, CA. (R825433)

    EPA Science Inventory

    During the late Holocene, sediment deposition on the lowland Cosumnes River floodplain, CA has depended on factors that varied temporally and spatially, such as basin subsidence, sea level rise, flow, and sediment supply from both the Sacramento River system and from the Cosum...

  14. Dietary exposure of three passerine species to PCDD/DFs from the Chippewa, Tittabawassee, and Saginaw River floodplains, Midland, Michigan, USA.

    PubMed

    Fredricks, Timothy B; Giesy, John P; Coefield, Sarah J; Seston, Rita M; Haswell, Melissa M; Tazelaar, Dustin L; Bradley, Patrick W; Moore, Jeremy N; Roark, Shaun A; Zwiernik, Matthew J

    2011-01-01

    Dietary exposure of house wrens (Troglodytes aedon), tree swallows (Tachycineta bicolor), and eastern bluebirds (Sialia sialis) to polychlorinated dibenzofurans (PCDFs) and polychlorinated dibenzo-p-dioxins (PCDDs) near Midland, Michigan (USA) was evaluated based on site-specific data, including concentrations of residues in bolus samples and individual invertebrate orders and dietary compositions by study species. Site-specific dietary compositions for the three species were similar to those reported in the literature, but differed in their relative proportions of some dietary items. Oligocheata (non-depurated) and Brachycera (Diptera) contained the greatest average concentrations of ΣPCDD/DFs of the major site-specific dietary items collected via food web-based sampling. Average ingestion values of ΣPCDD/DFs from site-specific bolus-based and food web-based dietary concentrations for nestlings at study areas (SAs) were 6- to 20-fold and 2- to 9-fold greater than at proximally located reference areas (RAs), respectively. Average ingestion values of total 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQ(WHO - Avian)) from site-specific bolus-based and food web-based dietary concentrations for nestlings at SAs were 31- to 121-fold and 9- to 64-fold greater than at proximally located RAs, respectively. Estimates of ΣPCDD/DFs and TEQ(WHO - Avian) tissue concentrations based on nestling dietary exposures were greater than those measured. Plausible explanations include nestling metabolism of 2,3,7,8-tetrachlorodibenzofuran and assimilation rates of less than the 70% assumed to occur over the nestling growth period. Profiles of the relative concentrations of individual PCDD/DF congeners in samples of invertebrates and bolus at SAs on the Tittabawassee River downstream of the source of contamination were dominated by 1,2,3,4,6,7,8,9-octachlorodibenzo-p-dioxin (22% to 44%) and 2,3,7,8-tetrachlorodibenzofuran (18% to 50%).

  15. Sediment and nutrient trapping as a result of a temporary Mississippi River floodplain restoration: The Morganza Spillway during the 2011 Mississippi River Flood

    USGS Publications Warehouse

    Kroes, Daniel; Schenk, Edward R.; Noe, Gregory; Benthem, Adam J.

    2015-01-01

    The 2011 Mississippi River Flood resulted in the opening of the Morganza Spillway for the second time since its construction in 1954 releasing 7.6 km3 of water through agricultural and forested lands in the Morganza Floodway and into the Atchafalaya River Basin. This volume, released over 54 days, represented 5.5% of the Mississippi River (M.R.) discharge and 14% of the total discharge through the Atchafalaya River Basin (A.R.B.) during the Spillway operation and 1.1% of the M.R. and 3.3% of the A.R.B. 2011 water year discharge. During the release, 1.03 teragrams (Tg) of sediment was deposited on the Morganza Forebay and Floodway and 0.26 Tg was eroded from behind the Spillway structure. The majority of deposition (86 %) occurred in the Forebay (upstream of the structure) and within 4 km downstream of the Spillway structure with minor deposition on the rest of the Floodway. There was a net deposition of 26 × 10−4 Tg of N and 5.36 × 10−4 Tg of P, during the diversion, that was equivalent to 0.17% N and 0.33% P of the 2011 annual M.R. load. Median deposited sediment particle size at the start of the Forebay was 13 μm and decreased to 2 μm 15 km downstream of the Spillway structure. Minimal accretion was found greater than 4 km downstream of the structure suggesting the potential for greater sediment and nutrient trapping in the Floodway. However, because of the large areas involved, substantial sediment mass was deposited even at distances greater than 30 km. Sediment and nutrient deposition on the Morganza Floodway was limited because suspended sediment was quickly deposited along the flowpath and not refreshed by incremental water exchanges between the Atchafalaya River (A.R.) and the Floodway. Sediment and nutrient trapping could have been greater and more evenly distributed if additional locations of hydraulic input from and outputs to the A.R. (connectivity) were added.

  16. Subsurface crustacean communities as proxy for groundwater-surface water interactions in the Henares and Tajuña Rivers floodplains, central Spain

    NASA Astrophysics Data System (ADS)

    Rasines Ladero, Ruben; Iepure, Sanda; Careño, Francisco; de Bustamante, Irene

    2013-04-01

    In the last decades, the linkage between surface water - groundwater via the hyporheic zone and the alluvial floodplains become more and more acknowledged. Hydrological exchanges between the stream and hyporheic zone ensure the transport of matter and energy and provide support for biogeochemical processes occurring in-stream bed sediments. Furthermore, the hyporheic zone is directly linked to permeable alluvial aquifers of which exchanges in both directions ensure the withstanding of a mixt biotic community's that may originate either from the surface benthic habitats or from the shallow aquifer. Data on the subsurface crustacean assemblages are used to infer the surface-groundwater interaction in two-groundwater fed-streams in central Spain. The survey was conducted on 20 hyporheic sites (20-40 cm depth) and 28 shallow or deep boreholes. Multivariate statistics were applied to test for differences in crustacean communities resulting from changes in water chemistry between the upstream and downstream parts of the alluvial aquifer, and between the hyporheic zone and the alluvial aquifer. Our aims were to: 1) test whether groundwater discharges in-stream bed sediments are reflected in changes in the crustacean assemblage's structure; and 2) establish whether the surface water influence decreases with increasing groundwater depth and distance from the river. We further aimed to test whether the diversity-stability ecotonal paradigm associated with the distinct level of disturbances and stability at the interface surface-groundwater and the aquifer is reflected in groundwater crustacean community structure. We start from the assumption that groundwater ecosystems undergo significant changes in space and time, and that classical groundwater stability hypothesis ought to be changed to concepts operative for surface ecosystems: disturbance and resilience. The streams are characterised by distinct gradients of surface-groundwater exchanges at spatial scale, with major interactions at the rivers headwaters compare to the lower part of the alluvial aquifer. The origin of the water in-stream bed sediments is indicated by water chemistry, whereas crustacean communities indicate surface-groundwater exchanges by modifications of the community's structure i.e., upwelling groundwater is indicated by large stygobites populations (obligate groundwater species), whereas downwelling surface waters is usually linked to mixed stygophiles and stygoxene populations. The downwelled surface water flow pattern has detectable influence on increasing nutrient content in shallow hyporheic waters and consequently, crustacean assemblages show distinctly high density and diversity. The crustacean diversity slightly declines with increasing depth, whereas no relationship with the population density was detected. The results obtained highlight the recognition of crustacean communities as alternative proxy to investigate surface water-groundwater exchanges. We concluded that the hydrological connections between surface water and groundwater had a major influence in shaping the crustacean communities structure by controlling the diversity, density and ecological configuration of these populations. In the perspective of increasing alteration of surface-groundwater exchanges due to human actions, both small and large scale monitoring surveys are critical for placing groundwater changes in quality and quantity into a wider context, in order to enhance the assessment of subsurface ecosystems sensitivity to anthropogenic forcing and consequently reduce the negative impact.

  17. Limnology in the Upper Paraná River floodplain: large-scale spatial and temporal patterns, and the influence of reservoirs.

    PubMed

    Roberto, M C; Santana, N N; Thomaz, S M

    2009-06-01

    Knowledge of abiotic limnological factors is important to monitor changes caused by humans, and to explain the structure and dynamics of populations and communities in a variety of inland water ecosystems. In this study, we used a long term data-set (eight years) collected in 10 habitats with different features (river channels, and connected and isolated lakes) to describe the spatial and temporal patterns of some of the principal limnological factors. In general, the degree of connectivity of the lakes, together with the rivers to which the lakes are connected, were important determinants of their limnological characteristics. These differences are expected, because rivers entering the floodplain come from different geological regions and are subject to different human impacts. At large spatial scales, these differences contribute to the increased habitat diversity of the floodplain and thus to its high biodiversity. With regard to temporal variation, Secchi-disk transparency increased, and total phosphorus decreased in the Paraná River main channel during the last 20 years. Although these changes are directly attributed to the several reservoir cascades located upstream, the closing of the Porto Primavera dam in 1998 enhanced this effect. The increase in water transparency explains biotic changes within the floodplain. The lower-phosphorus Paraná River water probably dilutes concentrations of this element in the floodplain waterbodies during major floods, with future consequences for their productivity.

  18. Multiple Lines of Evidence Risk Assessment of Terrestrial Passerines Exposed to PCDFs and PCDDs in the Tittabawassee River Floodplain, Midland, Michigan, USA

    PubMed Central

    Fredricks, Timothy B.; Giesy, John P.; Coefield, Sarah J.; Seston, Rita M.; Tazelaar, Dustin L.; Roark, Shaun A.; Kay, Denise P.; Newsted, John L.; Zwiernik, Matthew J.

    2011-01-01

    A site-specific multiple lines of evidence risk assessment was conducted for house wrens (Troglodytes aedon) and eastern bluebirds (Sialia sialis) along the Tittabawassee River downstream of Midland, Michigan, where concentrations of polychlorinated dibenzofurans (PCDFs) and polychlorinated dibenzo-p-dioxins (PCDDs) in flood-plain soils and sediments are greater compared to upstream areas and some of the greatest anywhere in the world. Lines of evidence supporting the population-level assessment endpoints included site-specific dietary- and tissue-based exposure assessments and population productivity measurements during breeding seasons 2005–2007. While a hazard assessment based on site-specific diets suggested that populations residing in the downstream floodplain had the potential to be affected, concentrations in eggs compared to appropriate toxicity reference values (TRVs) did not predict a potential for population-level effects. There were no significant effects on reproductive success of either species. The most probable cause of the apparent difference between the dietary- and tissue-based exposure assessments was that the dietary-based TRVs were overly conservative based on intraperitoneal injections in the ring-necked pheasant. Agreement between the risk assessment based on concentrations of PCDFs and PCDDs in eggs and reproductive performance in both species supports the conclusion of a small potential for population-level effects at this site. PMID:21804755

  19. Geomorphology and geologic characteristics of the Savannah River floodplain in the vicinity of the Savannah River Site, South Carolina and Georgia

    SciTech Connect

    Leeth, D.C. ); Nagle, D.D. )

    1994-03-01

    The potential for migration of contaminated ground water from the US Department of Energy Savannah River Site (SRS) beneath the Savannah River into Georgia (trans-river flow) is a subject of recent environmental concern. The degree of incision of the ancestral Savannah River into the local hydrogeologic framework is a significant consideration in the assessment of trans-river flow. The objective of this investigation is to identify the geologic formations which subcrop beneath the alluvium and the extent to which the river has incised regional confining beds. To meet this objective 18 boreholes were drilled to depths of 25 to 100 feet along three transects across the present floodplain. These borings provided data on the hydrogeologic character of the strata that fill the alluvial valley. The profiles from the borehole transects were compared with electrical conductivity (EM-34) data to ascertain the applicability of this geophysical technique to future investigations.

  20. Effects of flooding regime on the feeding activity and body condition of piscivorous fish in the Upper Paraná River floodplain.

    PubMed

    Luz-Agostinho, K D G; Agostinho, A A; Gomes, L C; Júlio, H F; Fugi, R

    2009-06-01

    Flood pulses affect floodplain enrichment via the incorporation of nutrients and terrestrial biomass. As a result, they positively affect the body condition of aquatic organisms. This paper evaluates whether the absence of floods (resulting from dam control) affects the feeding activity and body condition of piscivorous fish. In addition, whether piscivores respond similarly to alterations in the flooding regime was assessed. Five piscivorous species were selected (Acestrorhynchus lacustris, Hoplias aff. malabaricus, Plagioscion squamosissimus, Rhaphiodon vulpinus, and Salminus brasiliensis). The fish were captured in four distinct years and in three river subsystems with differentiated water level fluctuations (Ivinheira = not regulated; Baía = regulated by the Paraná River level; Paraná = regulated by dams). Feeding activity and body condition were evaluated using the mean values of the standard residuals generated by regression models between body and stomach weights and standard length and body weight (all log-transformed). Differences among years and subsystems were evaluated via two-way analysis of variance. Pearson and Spearman correlations were performed between flooding attributes (duration, amplitude, timing, and daily variability) and feeding activity and body condition. Feeding activity differed across subsystems, whereas body condition varied across years, depending on the subsystem. Hoplias aff malabaricus (an ambusher adapted to starvation) presented feeding activity independent of the flooding regime and also presented better body condition in times of high water levels. Rhaphidon vulpinus exhibited variations in feeding activity but did not present alterations in body condition. The other species presented poorer body condition in years or subsystems with regular floods. Correlations identified that the duration and timing of floods had negative effects on body condition, whereas amplitude and mean annual water level improved feeding activity. Therefore, regular floods affect the feeding activity and body condition of piscivorous fish, and the response of each species depends on the existence or absence of pre-adaptation to long periods of starvation. Consequently, considering the role of the flood pulse in determining the availability of feeding resources for early life stages of piscivores, control of the flood pulse by dams is also disadvantageous for piscivorous fish.

  1. Improved dissolved oxygen status following removal of exotic weed mats in important fish habitat lagoons of the tropical Burdekin River floodplain, Australia.

    PubMed

    Perna, Colton; Burrows, Damien

    2005-01-01

    The Burdekin delta floodplain, north Queensland, is highly modified for agricultural purposes. Riparian condition is very poor and exotic aquatic weeds dominate waterways. Historically, most streams and lagoons were highly seasonal, but those now used for the delivery of irrigation water maintain elevated flows and increased turbidity and nutrient loading. These factors have aided exotic weed growth and many major lagoons are covered by dense water hyacinth (Eichhornia crassipes) mats which greatly reduce dissolved oxygen levels, one of the most important water quality variables for aquatic fauna. Mechanical harvesting of water hyacinth from several of these lagoons resulted in rapid and substantial increases in dissolved oxygen saturation, and improved suitability of the habitat to support fish species. Decrease in dissolved oxygen as water passes sequentially through weed-infested lagoons, justified the approach of harvesting upstream lagoons first, however, the channels that connect these lagoons remain weed-infested and are still impacting upon downstream oxygen levels. PMID:15757716

  2. Properties and reactivity of aquatic organic matter from an Amazonian floodplain system

    NASA Astrophysics Data System (ADS)

    Perez, M. A. P.; Benedetti, M. F.; Moreira-Turcq, P.

    2009-04-01

    The aim of this study was to characterize the nature of the bulk dissolved organic matter (DOM) in different types of environments in the Amazon River-floodplain system and determine the importance of two different fractions of dissolved organic matter onto adsorption processes that occurs through the transport of organic matter in the Amazon Basin. Seven samples were collected in the Amazon River - "Lago Grande de Curuai" floodplain system, in rising water levels cruise (March 2006). The samples were taken in the Amazon main stem, in white and black floodplain waters, and in the middle of a phytoplaktonic bloom. The bulk, dissolved (i.e. < 0.22 micrometer), hydrophobic (HPO) and transphilic (TPH) fractions extracted by XAD-8 and XAD-4 columns chromatography respectively were isolated. Organic carbon (OC) and total nitrogen (TN) concentrations, Specific UV absorbance (SUVA), Size-Exclusion Chromatography (SEC), d13C and d15N isotopes, and reactivity (acid-base titration) were characterized for these fractions. Adsorption experiments onto mineral phase from de surface sediment of the Curuai floodplain lake (rich in smectite and kaolinite) were realized with HPO and TPH fractions. The OC concentrations in the natural organic matter (Bulk and < 0.22 micrometer fractions) varied between 3.7-5.7 mg/L. The OC and TN concentrations varied between 510 - 528 mg C/g in the HPO fraction, and 408 - 462 mg C/g in the TPH compounds and between 14.3 - 17.6 mg N/g (HPO), and 22.1 - 30.0 mg N/g (TPH). The molecular weight of both fractions (HPO and TPH) didn't present significant variation. Both fractions presented high aromaticity and they were rich in carboxylic groups, although smaller values are systematically reported for the HPO fractions. The OM of the main stem was the most adsorbed, followed by the white water lake, the phytoplanktonic bloom, and black water lake sample. These results helped us to strengthen the hypothesis that the organic matter carried from the river and

  3. Sediment deposition and associated organic carbon dynamics in a tropical River system; the Tana River (Kenya)

    NASA Astrophysics Data System (ADS)

    Omengo, Fred; Alleman, Tine; Geeraert, Naomi; Bouillon, Steven; Govers, Gerard

    2014-05-01

    Floodplains are known to play a potentially important role in regulating the downstream transport of sediments, carbon, and nutrients in river systems. We investigated sediment and carbon transport, retention and deposition in the floodplains of the lower Tana River (Kenya), between the two main downstream gauging stations Garissa and Garsen. The Tana River is the largest river in Kenya and runs for more than 1,000 km from Kenya's highlands (Mt Kenya and the Aberdare mountains). The catchment covers around 100,000km² and the hydrology is controlled by the shifting of intertropical convergence Zone (ITCZ), leading to a bimodal precipitation cycle. Sediment cores were taken at various sites within the floodplains, and analysed for bulk density, organic carbon (OC) and nitrogen content, stable isotope signatures (δ13C) of organic C, and grain size distribution. We determined 137Cs and 210Pbxs activities in order to estimate historical sedimentation rates and to quantify the post-depositional losses of organic carbon. In addition, we measured fresh sediment deposition rates immediately after an extended period of flooding, along with associated flood heights and the distance relative to the main River . Fresh sediment deposition rates ranged between 1mm and 15mm for the period of study at an average rate of 1.13 gcm-3 (dry weight). This varied with distance of the floodplain from the main river and its elevation relative to the full bank. The fresh deposited sediment had an average organic carbon content of 1.55 ± 0.42%. Sediment cores showed a strong downcore gradient in OC content, from 3 - 12%C in the top layers to typically less than 0.5 % below 50 cm. The C:N ratios varied from 8 to 16 with majority averaging 9-11. Stable isotope signatures (δ13C) of organic C varied between -28‰ to -16‰ for the deeper core samples. 137Cs and 210Pbxs profiles indicate a vertical accretion at an average rate of 0.6 cm per year in the sites measured so far. The Tana river

  4. Geochemical fractions of copper in soil chronosequences of selected European floodplains.

    PubMed

    Graf, M; Lair, G J; Zehetner, F; Gerzabek, M H

    2007-08-01

    The influence of soil formation on copper sorption is documented based on chronosequences of soils from three river floodplains in Europe (Danube, Ebro and Elbe). Sequential extraction was used to fractionate copper in original and spiked soils in order to study the long-term and short-term behaviour of copper retention. Copper partitioning among defined geochemical fractions was mainly determined by soil pH and the contents of carbonates, organic matter and Fe-/Mn-oxides and hydroxides. Copper extracted with NH(2)OH.HCl correlated well with the contents of crystalline Fe-oxides and hydroxides, demonstrating increasing retention capacity with progressing soil development. Copper retained in original soils was found in more strongly bound fractions, whereas sorption of freshly added copper was primarily influenced by the presence of carbonates. Beyond the effect of progressing soil formation, variations in organic carbon contents due to different land use history affected the copper retention capacity of the investigated soils.

  5. Need for ecosystem management of large rivers and their floodplains: These phenomenally productive ecosystems produce fish and wildlife and preserve species

    SciTech Connect

    Sparks, R.E.

    1995-03-01

    Most of the 79 large river floodplain ecosystems in the world have been altered by human activities and the rest are likely to be altered soon. Ecosystem management works to guide rather than thwart, natural processes. This article describes briefly the history of floodplain and flood plain management and then focuses on the importance of large river-floodplain ecosystems and some of the consequences of altering the natural river processes, functions, and connectivity. The species-focused management system typically employed by natural resource agencies is contrasted to the ecosystem approach to river-flood plain management. Ecological management is defined as working with the natural driving forces and variability of the ecosystems with the goal of maintaining or recovering biological integrity. Flood-pulses are also a focus because they drive the system and the great floods on several continents in the last years. 88 refs., 10 figs.

  6. Computationally efficient and flexible modular modelling approach for river and urban drainage systems based on surrogate conceptual models

    NASA Astrophysics Data System (ADS)

    Wolfs, Vincent; Willems, Patrick

    2015-04-01

    Water managers rely increasingly on mathematical simulation models that represent individual parts of the water system, such as the river, sewer system or waste water treatment plant. The current evolution towards integral water management requires the integration of these distinct components, leading to an increased model scale and scope. Besides this growing model complexity, certain applications gained interest and importance, such as uncertainty and sensitivity analyses, auto-calibration of models and real time control. All these applications share the need for models with a very limited calculation time, either for performing a large number of simulations, or a long term simulation followed by a statistical post-processing of the results. The use of the commonly applied detailed models that solve (part of) the de Saint-Venant equations is infeasible for these applications or such integrated modelling due to several reasons, of which a too long simulation time and the inability to couple submodels made in different software environments are the main ones. Instead, practitioners must use simplified models for these purposes. These models are characterized by empirical relationships and sacrifice model detail and accuracy for increased computational efficiency. The presented research discusses the development of a flexible integral modelling platform that complies with the following three key requirements: (1) Include a modelling approach for water quantity predictions for rivers, floodplains, sewer systems and rainfall runoff routing that require a minimal calculation time; (2) A fast and semi-automatic model configuration, thereby making maximum use of data of existing detailed models and measurements; (3) Have a calculation scheme based on open source code to allow for future extensions or the coupling with other models. First, a novel and flexible modular modelling approach based on the storage cell concept was developed. This approach divides each

  7. Microbiological irrigation water quality of the Marchfeld canal system.

    PubMed

    Stauffer, F; Makristathis, A; Hassl, A; Nowotny, S; Neudorfer, W

    2001-07-01

    The Marchfeld basin with a size of approximately 1000 km2 represents the Austrian "granary". To prevent shortage of water as a result of increased ground water removal for irrigation, industrial purposes and drinking water supply, a canal being 18 km in length was constructed from the Danube to the center of the Marchfeld. From there, water is further distributed via two creeks (Russbach and Stempfelbach). This study was intended to evaluate whether the surface water of the Marchfeld canal system can be classified into hygienic-microbiological categories as proposed by DIN (Deutsche Industrienorm) standards for irrigation water. For this purpose, water sampled monthly from three different sampling sites from 1996 to 1999 was examined for E. coli and enterococci. In addition, water samples were examined for salmonella twice a year from 1996 to 1998 and for cryptosporidia six times during the year 1999. Though the water showed varying degrees of fecal load, the results of the examinations revealed that only one of the three sampling sites showed constant quality levels according to the DIN classification system over prolonged periods of time. However, exceeding of the limit values was occasionally observed indicating the need for regular bacteriological examinations. The high variation of the results from the other sampling sites hardly permits a definite classification in one of the quality classes. PMID:11556148

  8. Ultraviolet-Visible and Fluorescence Analyses Reveal the Spatial and Seasonal Variability of Dissolved Organic Matter through the Vadose Zone to Groundwater at the Rifle, Colorado River Floodplain Site

    NASA Astrophysics Data System (ADS)

    Dong, W.; Wan, J.; Tokunaga, T. K.; Gilbert, B.; Kim, Y.; Williams, K. H.

    2014-12-01

    Dissolved organic matter (DOM) is a complex and poorly understood mixture of natural organic compounds that play important roles in terrestrial C transport and biogeochemical cycles, and its reactivity makes it sensitive to seasonal variations and longer term climate change. As a component within the LBNL Science Focus Area 2.0, this study is designed to determine the spatial and temporal variability of DOM concentrations and characteristics throughout the vadose zone and groundwater within a semi-arid floodplain at Rifle, Colorado. Three sets of vertically stratified pore water samplers and wells were installed along a groundwater flow transect. These installations allowed acquisition of vertically- and temporally-resolved pore water samples from the vadose zone, capillary fringe, and saturated zone from April 2013 to May 2014. Ultraviolet-visible absorbance (UVA) and fluorescence excitation-emission matrix (EEM) spectroscopy are being applied to trace the changes in DOM characteristics. Initial results indicate that the aromatic C contents (%) of DOM vary with depth and season and exhibit patterns distinct from groundwater. EEM analysis identified fulvic- and humic-like substances as the major fluorescent components of DOM in pore water samples. The concentrations of fulvic- and humic-like matter decreases with depth within the vadose zone, and increases from Spring and Summer to Fall, then decreases in Winter. The trend is consistent with UVA results. Microbial by-product-like components in DOM show higher concentrations in the vadose zone, and decrease from Spring to Winter. Fulvic- and humic-like substances are the only detectable fluorophore components in the groundwater samples. The results from both UVA and EEM suggest that (1) aromatic C or fulvic- and humic-like matter are preferentially adsorbed within shallower sediments during transport; and (2) microbial transformations of DOM composition may occur in the vadose zone, particularly during late Spring and early Summer.

  9. Multiple effects of hydrological connectivity on floodplain processes in human modified river systems

    NASA Astrophysics Data System (ADS)

    Hein, Thomas; Bondar-Kunze, Elisabeth; Preiner, Stefan; Reckendorfer, Walter; Tritthart, Michael; Weigelhofer, Gabriele; Welti, Nina

    2014-05-01

    Floodplain and riparian ecosystems provide multiple functions and services of importance for human well-being and are of strategic importance for different sectors at catchment scale. Especially floodplains in the vicinity of urban areas can be areas of conflicting interests ranging from different land use types, flood water retention, drinking water production and recreation to conservation of last remnants of former riverine landscape, as it is the case in floodplains in the Danube Nationalpark downstream Vienna. Many of these ecosystem functions and services are controlled by the exchange conditions between river main channel and floodplain systems, the hydrological connectivity. At the same time these systems have been highly altered and especially the connectivity has been severely impaired. Thus, far ranging effects of changes in hydrological connectivity at various levels can be expected in altered floodplain systems. The aim of this presentation is to explore the complex control of different ecosystem functions and associated services by different parameters of hydrological connectivity, ranging from nutrient, sediment and matter dynamics and biodiversity aspects. Increasing connectivity will be shown to impact microbial dynamics, sediment-water interactions, carbon dynamics and trophic conditions, thus affecting the fundamental functions of particular floodplain systems at various spatial and temporal scales. Based on these changes also the provision of ecosystem services of floodplains is affected. The results clearly show that hydrological connectivity needs to be considered in a sustainable management approach.

  10. Hydrologic indicators of hot spots and hot moments of mercury methylation potential along river corridors.

    PubMed

    Singer, Michael Bliss; Harrison, Lee R; Donovan, Patrick M; Blum, Joel D; Marvin-DiPasquale, Mark

    2016-10-15

    The biogeochemical cycling of metals and other contaminants in river-floodplain corridors is controlled by microbial activity responding to dynamic redox conditions. Riverine flooding thus has the potential to affect speciation of redox-sensitive metals such as mercury (Hg). Therefore, inundation history over a period of decades potentially holds information on past production of bioavailable Hg. We investigate this within a Northern California river system with a legacy of landscape-scale 19th century hydraulic gold mining. We combine hydraulic modeling, Hg measurements in sediment and biota, and first-order calculations of mercury transformation to assess the potential role of river floodplains in producing monomethylmercury (MMHg), a neurotoxin which accumulates in local and migratory food webs. We identify frequently inundated floodplain areas, as well as floodplain areas inundated for long periods. We quantify the probability of MMHg production potential (MPP) associated with hydrology in each sector of the river system as a function of the spatial patterns of overbank inundation and drainage, which affect long-term redox history of contaminated sediments. Our findings identify river floodplains as periodic, temporary, yet potentially important, loci of biogeochemical transformation in which contaminants may undergo change during limited periods of the hydrologic record. We suggest that inundation is an important driver of MPP in river corridors and that the entire flow history must be analyzed retrospectively in terms of inundation magnitude and frequency in order to accurately assess biogeochemical risks, rather than merely highlighting the largest floods or low-flow periods. MMHg bioaccumulation within the aquatic food web in this system may pose a major risk to humans and waterfowl that eat migratory salmonids, which are being encouraged to come up these rivers to spawn. There is a long-term pattern of MPP under the current flow regime that is likely to be

  11. Hydrologic indicators of hot spots and hot moments of mercury methylation potential along river corridors.

    PubMed

    Singer, Michael Bliss; Harrison, Lee R; Donovan, Patrick M; Blum, Joel D; Marvin-DiPasquale, Mark

    2016-10-15

    The biogeochemical cycling of metals and other contaminants in river-floodplain corridors is controlled by microbial activity responding to dynamic redox conditions. Riverine flooding thus has the potential to affect speciation of redox-sensitive metals such as mercury (Hg). Therefore, inundation history over a period of decades potentially holds information on past production of bioavailable Hg. We investigate this within a Northern California river system with a legacy of landscape-scale 19th century hydraulic gold mining. We combine hydraulic modeling, Hg measurements in sediment and biota, and first-order calculations of mercury transformation to assess the potential role of river floodplains in producing monomethylmercury (MMHg), a neurotoxin which accumulates in local and migratory food webs. We identify frequently inundated floodplain areas, as well as floodplain areas inundated for long periods. We quantify the probability of MMHg production potential (MPP) associated with hydrology in each sector of the river system as a function of the spatial patterns of overbank inundation and drainage, which affect long-term redox history of contaminated sediments. Our findings identify river floodplains as periodic, temporary, yet potentially important, loci of biogeochemical transformation in which contaminants may undergo change during limited periods of the hydrologic record. We suggest that inundation is an important driver of MPP in river corridors and that the entire flow history must be analyzed retrospectively in terms of inundation magnitude and frequency in order to accurately assess biogeochemical risks, rather than merely highlighting the largest floods or low-flow periods. MMHg bioaccumulation within the aquatic food web in this system may pose a major risk to humans and waterfowl that eat migratory salmonids, which are being encouraged to come up these rivers to spawn. There is a long-term pattern of MPP under the current flow regime that is likely to be

  12. Hydrologic indicators of hot spots and hot moments of mercury methylation potential along river corridors

    USGS Publications Warehouse

    Singer, Michael B.; Harrison, Lee R.; Donovan, Patrick M.; Blum, Joel D.; Marvin-DiPasquale, Mark C.

    2016-01-01

    The biogeochemical cycling of metals and other contaminants in river-floodplain corridors is controlled by microbial activity responding to dynamic redox conditions. Riverine flooding thus has the potential to affect speciation of redox-sensitive metals such as mercury (Hg). Therefore, inundation history over a period of decades potentially holds information on past production of bioavailable Hg. We investigate this within a Northern California river system with a legacy of landscape-scale 19th century hydraulic gold mining. We combine hydraulic modeling, Hg measurements in sediment and biota, and first-order calculations of mercury transformation to assess the potential role of river floodplains in producing monomethylmercury (MMHg), a neurotoxin which accumulates in local and migratory food webs. We identify frequently inundated floodplain areas, as well as floodplain areas inundated for long periods. We quantify the probability of MMHg production potential (MPP) associated with hydrology in each sector of the river system as a function of the spatial patterns of overbank inundation and drainage, which affect long-term redox history of contaminated sediments. Our findings identify river floodplains as periodic, temporary, yet potentially important, loci of biogeochemical transformation in which contaminants may undergo change during limited periods of the hydrologic record. We suggest that inundation is an important driver of MPP in river corridors and that the entire flow history must be analyzed retrospectively in terms of inundation magnitude and frequency in order to accurately assess biogeochemical risks, rather than merely highlighting the largest floods or low-flow periods. MMHg bioaccumulation within the aquatic food web in this system may pose a major risk to humans and waterfowl that eat migratory salmonids, which are being encouraged to come up these rivers to spawn. There is a long-term pattern of MPP under the current flow regime that is likely to be

  13. Changes in lowland floodplain sedimentation processes: pre-disturbance to post-rehabilitation, Cosumnes River, CA

    NASA Astrophysics Data System (ADS)

    Florsheim, Joan L.; Mount, Jeffrey F.

    2003-12-01

    During the late Holocene, sediment deposition on the lowland Cosumnes River floodplain, CA has depended on factors that varied temporally and spatially, such as basin subsidence, sea level rise, flow, and sediment supply from both the Sacramento River system and from the Cosumnes River system itself, and anthropogenic changes. Through field investigations and analyses of historical maps, bridge core logs, and sediment size distributions, we link hydrogeomorphic processes to three stages of floodplain sedimentation on the lowland Cosumnes River. Stage I (1000-200 YBP) combined late Holocene pre-disturbance flood basin overflow and anastomosing river processes deposited spatially variable sediment consisting of gray-blue clay (87% clay) interlayered with relatively thin coarser sediment. Pre-disturbance Holocene deposition rates of up to ˜3.0 mm/year kept pace with sea level rise and tectonic basin subsidence. Stage II (200 to ˜10 YBP) anthropogenic disturbances caused a rapid increase in floodplain sedimentation rates up to 25 mm/year between 1849 and ˜1920, and deposited a relatively coarser reddish-brown sandy clay (˜40% clay) layer that overlies the basin deposits. Between ˜1920 and 1990 AD, sedimentation was greatly limited on the lower Cosumnes floodplain because levees inhibited connectivity between both the Sacramento and Cosumnes River systems and the Cosumnes floodplain. During this stage, the density of channel segments in the anastomosing river floodplain decreased by 30% as agricultural activities filled secondary channels and leveled floodplain topography. During Stage III (˜10 YBP to the present), post-rehabilitation floodplain sand splay complex sediment deposited after 1998 AD resulted from intentionally breaching levees to promote habitat at the Cosumnes River Preserve. The splay complex is dominated by medium to very coarse sand with finer intervening layers. The post-rehabilitation splay complex overlies the older basin deposits in a

  14. Assessing the utility of geospatial technologies to investigate environmental change within lake systems.

    PubMed

    Politi, Eirini; Rowan, John S; Cutler, Mark E J

    2016-02-01

    Over 50% of the world's population live within 3 km of rivers and lakes highlighting the on-going importance of freshwater resources to human health and societal well-being. Whilst covering c. 3.5% of the Earth's non-glaciated land mass, trends in the environmental quality of the world's standing waters (natural lakes and reservoirs) are poorly understood, at least in comparison with rivers, and so evaluation of their current condition and sensitivity to change are global priorities. Here it is argued that a geospatial approach harnessing existing global datasets, along with new generation remote sensing products, offers the basis to characterise trajectories of change in lake properties e.g., water quality, physical structure, hydrological regime and ecological behaviour. This approach furthermore provides the evidence base to understand the relative importance of climatic forcing and/or changing catchment processes, e.g. land cover and soil moisture data, which coupled with climate data provide the basis to model regional water balance and runoff estimates over time. Using examples derived primarily from the Danube Basin but also other parts of the World, we demonstrate the power of the approach and its utility to assess the sensitivity of lake systems to environmental change, and hence better manage these key resources in the future. PMID:26521989

  15. Multiscale error analysis, correction, and predictive uncertainty estimation in a flood forecasting system

    NASA Astrophysics Data System (ADS)

    Bogner, K.; Pappenberger, F.

    2011-07-01

    River discharge predictions often show errors that degrade the quality of forecasts. Three different methods of error correction are compared, namely, an autoregressive model with and without exogenous input (ARX and AR, respectively), and a method based on wavelet transforms. For the wavelet method, a Vector-Autoregressive model with exogenous input (VARX) is simultaneously fitted for the different levels of wavelet decomposition; after predicting the next time steps for each scale, a reconstruction formula is applied to transform the predictions in the wavelet domain back to the original time domain. The error correction methods are combined with the Hydrological Uncertainty Processor (HUP) in order to estimate the predictive conditional distribution. For three stations along the Danube catchment, and using output from the European Flood Alert System (EFAS), we demonstrate that the method based on wavelets outperforms simpler methods and uncorrected predictions with respect to mean absolute error, Nash-Sutcliffe efficiency coefficient (and its decomposed performance criteria), informativeness score, and in particular forecast reliability. The wavelet approach efficiently accounts for forecast errors with scale properties of unknown source and statistical structure.

  16. Assessing the utility of geospatial technologies to investigate environmental change within lake systems.

    PubMed

    Politi, Eirini; Rowan, John S; Cutler, Mark E J

    2016-02-01

    Over 50% of the world's population live within 3 km of rivers and lakes highlighting the on-going importance of freshwater resources to human health and societal well-being. Whilst covering c. 3.5% of the Earth's non-glaciated land mass, trends in the environmental quality of the world's standing waters (natural lakes and reservoirs) are poorly understood, at least in comparison with rivers, and so evaluation of their current condition and sensitivity to change are global priorities. Here it is argued that a geospatial approach harnessing existing global datasets, along with new generation remote sensing products, offers the basis to characterise trajectories of change in lake properties e.g., water quality, physical structure, hydrological regime and ecological behaviour. This approach furthermore provides the evidence base to understand the relative importance of climatic forcing and/or changing catchment processes, e.g. land cover and soil moisture data, which coupled with climate data provide the basis to model regional water balance and runoff estimates over time. Using examples derived primarily from the Danube Basin but also other parts of the World, we demonstrate the power of the approach and its utility to assess the sensitivity of lake systems to environmental change, and hence better manage these key resources in the future.

  17. Hydrologic indicators of hot spots and hot moments of mercury methylation along river corridors

    NASA Astrophysics Data System (ADS)

    Singer, Michael; Harrison, Lee; Donovan, Patrick; Blum, Joel; Marvin-DiPasquale, Mark

    2016-04-01

    The biogeochemical cycling of metals and other contaminants river-floodplain corridors is controlled by microbial activity is often affected by dynamic redox conditions. Riverine flooding thus has the potential to affect speciation of redox-sensitive metals such as mercury (Hg). Therefore, flow history over a period of decades potentially holds information on past production of bioavailable Hg. We investigate this process within a Northern California river system that has a legacy of industrial-scale 19th century hydraulic gold mining. In the first known application of this methodology, we combine hydraulic modeling, measurements of Hg species in sediment and biota, and first-order calculations to assess the role of river floodplains in producing monomethylmercury (MMHg), which accumulates in local and migratory biota. We identify areas that represent 'hot spots' (frequently inundated areas of floodplains) and 'hot moments' (floodplain areas inundated for consecutive long periods). We show that the probability of MMHg production in each sector of the river system is dependent on the spatial patterns of overbank flow and drainage, which affect its long-term redox history. MMHg bioaccumulation within the aquatic food web may pose a major risk to humans and waterfowl that eat migratory salmonids, which are being encouraged to come up these rivers to spawn, and there appears to be no end to MMHg production under a regime of increasingly common large floods with extended duration. These findings identify river floodplains as periodic, temporary, yet important, loci of biogeochemical transformation in which contaminants may undergo change during limited periods of the historical hydrologic record. We suggest that inundation is the primary driver of MMHg production in river corridors and that the entire flow history must be analyzed in terms of magnitude and frequency of inundation in order to accurately assess biogeochemical risks, rather than merely highlighting the

  18. Spatial variability in hydrologic connectivity between a coastal river and its floodplain

    NASA Astrophysics Data System (ADS)

    Castillo, C. R.; Guneralp, I.; Hales, B. U.

    2015-12-01

    Significant in the transport and dispersal of energy, matter, and biota within riverine environments, hydrologic connectivity has become fundamental in understanding river-floodplain process and concepts associated with environmental flows. Hydrologic connectivity between a river and its floodplain is dependent on floodplain geomorphology, channel hydraulics, land cover, and groundwater dynamics. In this study, we examine the floodplain morphology of the Mission River on the Coastal Bend of Texas. Utilizing a LiDAR-derived digital elevation model, we develop a relative digital elevation model (RDEM), with respect to river-stage, for a reach of the river-floodplain system. To assess the dominant flow directions, and thus, characterize the connectivity within the floodplain, we determine hydrological facets—landscape patches with their own respective outlet and high internal surface water connectivity. Guided by historical streamflow records, we systematically threshold the RDEM to determine the spatial characteristics of floodplain inundation under various river-stages. The increasing aerial extent of floodplain inundation from increases in river-stage results in distinct patterns of river channel-floodplain connectivity. We analyze the spatial arrangement of facets with regard to inundation in order to quantify floodplain connectivity and complexity at various river-stages using graph theory and landscape metrics. Our results indicate that floodplain connectivity and complexity change nonlinearly with increases in river-stage; with the greatest increases in connectivity and complexity occurring well below bankfull discharge. Floodplains provide valuable ecosystem services and this study helps improve our understanding of process-form relationships in river-floodplain systems' that informs environmental policy for effective management of these services.

  19. Mineralogical discrimination of the pleistocene loess/paleosol sections in Srijem and Baranja, Croatia

    NASA Astrophysics Data System (ADS)

    Galović, Lidija; Peh, Zoran

    2016-06-01

    Previous investigations of the mineralogical composition of loess sections (loess, loess-like sediments, paleosols, alluvial intercalations) in the Carpathian Basin have concluded that the Danube River is the dominant control on the loessitic parent material. These investigations also identify a significant role for the Danube's tributaries in creating local variations. The north-south alignment of these sections forms a transect from the central part of the Carpathian Basin to its southern edge. In this work, the mineral origin of loess sediments was identified by using the multivariate statistical method of discriminant function analysis. Two models were constructed based on the modal composition as the suite of predictor (independent) variables: one is using geographic location as the a priori grouping criterion (SECTION); another employing the difference between the sampling media (LITHOLOGY). Both of the examined discriminant models demonstrate the existence of the mixing zones. The Erdut section is a clear mixture of the mineralogies at the other studied locations, while loesses appear generally intermediate in mineralogy between alluvium and paleosol. The main rationale for the observed difference in modal composition between the Šarengrad and other analyzed sections is the proximity of the Šarengrad section to the Sava River floodplain and Dinaric Ophiolite Zone (DOZ), both important source areas for aeolian sediments in the southern edge of the Carpathian Basin that transport material from the Central Bosnian Mountains unit of DOZ. Chemically, the most resistant heavy minerals together with opaque minerals are exclusively associated with paleosols, being typical products of geochemical pedogenic processes.

  20. European Flood Awareness System - now operational

    NASA Astrophysics Data System (ADS)

    Alionte Eklund, Cristina.; Hazlinger, Michal; Sprokkereef, Eric; Garcia Padilla, Mercedes; Garcia, Rafael J.; Thielen, Jutta; Salamon, Peter; Pappenberger, Florian

    2013-04-01

    The European Commission's Communication "Towards a Stronger European Union Disaster Response" adopted and endorsed by the Council in 2010, underpins the importance of strengthening concerted actions for natural disasters including floods, which are amongst the costliest natural disasters in the EU. The European Flood Awareness System (EFAS) contributes in the case of major flood events. to better protection of the European Citizen, the environment, property and cultural heritage. The disastrous floods in Elbe and Danube rivers in 2002 confronted the European Commission with non-coherent flood warning information from different sources and of variable quality, complicating planning and organisation of aid. Thus, the Commission initiated the development of a European Flood Awareness System (EFAS) which is now going operational. EFAS has been developed and tested at the Joint Research Centre, the Commission's in house science service, in close collaboration with the National hydrological and meteorological services, European Civil Protection through the Monitoring and Information Centre (MIC) and other research institutes. EFAS provides Pan-European overview maps of flood probabilities up to 10 days in advance as well as detailed forecasts at stations where the National services are providing real time data. More than 30 hydrological services and civil protection services in Europe are part of the EFAS network. Since 2011, EFAS is part of the COPERNICUS Emergency Management Service, (EMS) and is now an operational service since 2012. The Operational EFAS is being executed by several consortia dealing with different operational aspects: • EFAS Hydrological data collection centre —REDIAM and ELIMCO- will be collecting historic and realtime discharge and water levels data in support to EFAS • EFAS Meteorological data collection centre —outsourced but running onsite of JRC Ispra. Will be collecting historic and realtime meteorological data in support to EFAS

  1. Organic matter turnover in a tropical floodplain shows hysteresis during a flood cycle

    NASA Astrophysics Data System (ADS)

    Zuijdgeest, Alissa; Baumgartner, Simon; Wehrli, Bernhard

    2016-04-01

    Tropical inland waters are increasingly recognized for their role in the global carbon cycle, but uncertainty about the effects of such systems on the transported organic matter remains. The seasonal interactions between river, floodplain, and vegetation result in highly dynamic systems, which can exhibit markedly different biogeochemical patterns throughout a flood cycle. In this study, we investigated patterns and rates of organic matter turnover, and determined responsible processes. Multi-probes upstream and downstream of the Barotse Plains, a pristine floodplain in the Upper Zambezi (Zambia), provided a high-resolution data set over the course of a hydrological cycle. Concentrations of oxygen, carbon dioxide, dissolved organic carbon, and suspended particulate matter in water column of the main channel showed clear hysteresis trends relative to hydrological parameters. Considering that the respiration rate in the river water remained rather low and stable throughout the year, these patterns indicated that degradation of the terrestrial organic matter was mainly occurring on the floodplain. We suggest that the main location of terrestrially-derived organic matter degradation in river-floodplain systems shifts during a flood cycle from the water of the main channel, to the soil-water interface on the floodplain when the water spends more time on the floodplain.

  2. The curse of abundance - A first attempt to design a hydrological multimodel system for forecasting purposes over Europe

    NASA Astrophysics Data System (ADS)

    Wetterhall, Fredrik; Dutra, Emanuel; Donnelly, Chantal; Strömbäck, Lena; Salamon, Peter; Alfieri, Lorenzo; Bogner, Konrad; Balsamo, Gianpaolo; Pappenberger, Florian

    2014-05-01

    Flood forecasting systems with coupled meteorological and hydrological models seldom apply more than one hydrological model although the usage of multiple meteorological models is common. For example, the European Flood Awareness system (EFAS) uses four different NWP systems (ECMWF Ensemble, High resolution, German Weather Service DWD and COSMO-LEPS) to produce probabilistic forecasts. This study focuses on the added value of using a range of different hydrological models in the context of flood forecasting. The models used were the gridded hydrological model LISFLOOD, the land surface scheme HTESSEL coupled to the flood-plain model CaMa-Flood and the semi-distributed hydrological model E-HYPE. The models were forced with 5 km gridded temperature and precipitation series calculated from observation stations over Europe, and the simulated discharge were compared with a number of runoff stations from the GRDC database. The results indicate that the hydrological models LISFLOOD and E-HYPE outperform HTESSEL, especially for smaller and medium-sized catchments. For the larger catchments, for example Danube, HTESSEL and CaMa-Flood performs better. The runoff from the models was also weighted using Bayesian Model Averaging according to their performance at the observational stations to create a "hybrid" model. The study highlights that using more than one hydrological model increases the robustness of a system as the model uncertainty as well as individual model performance can be used to improve flood forecasting systems. However, increasing the number of models inherently also increases the uncertainty of predictions, requiring more attention to the post-processing of the output.

  3. Computationally efficient and flexible modular modelling approach for river and urban drainage systems based on surrogate conceptual models

    NASA Astrophysics Data System (ADS)

    Wolfs, Vincent; Willems, Patrick

    2015-04-01

    Water managers rely increasingly on mathematical simulation models that represent individual parts of the water system, such as the river, sewer system or waste water treatment plant. The current evolution towards integral water management requires the integration of these distinct components, leading to an increased model scale and scope. Besides this growing model complexity, certain applications gained interest and importance, such as uncertainty and sensitivity analyses, auto-calibration of models and real time control. All these applications share the need for models with a very limited calculation time, either for performing a large number of simulations, or a long term simulation followed by a statistical post-processing of the results. The use of the commonly applied detailed models that solve (part of) the de Saint-Venant equations is infeasible for these applications or such integrated modelling due to several reasons, of which a too long simulation time and the inability to couple submodels made in different software environments are the main ones. Instead, practitioners must use simplified models for these purposes. These models are characterized by empirical relationships and sacrifice model detail and accuracy for increased computational efficiency. The presented research discusses the development of a flexible integral modelling platform that complies with the following three key requirements: (1) Include a modelling approach for water quantity predictions for rivers, floodplains, sewer systems and rainfall runoff routing that require a minimal calculation time; (2) A fast and semi-automatic model configuration, thereby making maximum use of data of existing detailed models and measurements; (3) Have a calculation scheme based on open source code to allow for future extensions or the coupling with other models. First, a novel and flexible modular modelling approach based on the storage cell concept was developed. This approach divides each

  4. Development of a grid-cell topographic surface for Okefenokee Swamp, Georgia

    USGS Publications Warehouse

    Loftin, C.S.; Rasberry, W.; Kitchens, W.M.

    2000-01-01

    The Okefenokee Swamp is a 160,000 ha freshwater wetland in Southeast Georgia, USA that developed in a landscape basin. Hydrologic variability across the swamp suggests that water-surface elevations are not uniform across the swamp. The topographic surface map discussed herein was developed to describe the swamp topography at local to landscape scales and relate the swamp peat- and sand-surface elevations to elevation above mean sea level. These data were then used to relate water-surface elevations across the swamp so that the swamp hydrologic environment could be described spatially and temporally with a spatial hydrology model. The swamp was divided into 5 sub-basins that reflect similar seasonal hydrodynamics but also indicate local conditions unique to the basins. Topographic gradient influences water-level dynamics in the western swamp (2 sub-basins), which is dominated by the Suwannee River floodplain. The eastern swamp (3 sub-basins) is terraced, and the regional hydrology is driven less by topographic gradient and more by precipitation and evapotranspiration volumes. The relatively steep gradient and berm and lake features in the western swamp's Suwannee River floodplain limit the spatial extent of the Suwannee River sill's effects, whereas system sensitivities to evapotranspiration rates are more important drivers of hydrology in the eastern swamp.

  5. Geomorphic adjustment to hydrologic modifications along a meandering river: Implications for surface flooding on a floodplain

    NASA Astrophysics Data System (ADS)

    Edwards, Brandon L.; Keim, Richard F.; Johnson, Erin L.; Hupp, Cliff R.; Marre, Saraline; King, Sammy L.

    2016-09-01

    Responses of large regulated rivers to contemporary changes in base level are not well understood. We used field measurements and historical analysis of air photos and topographic maps to identify geomorphic trends of the lower White River, Arkansas, USA, in the 70 years following base-level lowering at its confluence with the Mississippi River and concurrent with flood control by dams. Incision was identified below a knickpoint area upstream of St. Charles, AR, and increases over the lowermost ~90 km of the study site to ~2 m near the confluence with the Mississippi River. Mean bankfull width increased by 30 m (21%) from 1930 to 2010. Bank widening appears to be the result of flow regulation above the incision knickpoint and concomitant with incision below the knickpoint. Hydraulic modeling indicated that geomorphic adjustments likely reduced flooding by 58% during frequent floods in the incised, lowermost floodplain affected by backwater flooding from the Mississippi River and by 22% above the knickpoint area. Dominance of backwater flooding in the incised reach indicates that incision is more important than flood control on the lower White River in altering flooding and also suggests that the Mississippi River may be the dominant control in shaping the lower floodplain. Overall, results highlight the complex geomorphic adjustment in large river-floodplain systems in response to anthropogenic modifications and their implications, including reduced river-floodplain connectivity.

  6. Floodplain Formation and Cottonwood Colonization Patterns on the Willamette River, Oregon, USA.

    PubMed

    Dykaar; Wigington

    2000-01-01

    / Using a series of aerial photographs taken between 1936 and 1996, we trace coevolution of floodplain and riparian forest on the Willamette River. Within-channel barforms appear to be the predominant incipient floodplain landform and habitat for primary succession. Interlinked development of bar(s) and erosion of near banks, filling of channels, and establishment and growth of cottonwoods and willows results in coalescence with older floodplain. Sizeand internal structure of riparian forest patches reflect evolution of underlying barforms or channel beds. Floodplain matures as the active channel migrates away by repetition of the bar formation and near-bank erosion process, or is progressively abandoned by infilling and/or constriction with a bar. Other parts of the floodplain are recycled as eroding banks provide the coarse sediment and large woody debris for building new bars. A multichannel planform is maintained as building bars split flow; channels lengthen as bars and islands join into larger assemblages. Avulsion appears to cut new channels only short distances. Given the central role of bars and islands in building new floodplain habitat, we identify their area as a geomorphic indicator of river-floodplain integrity. We measure an 80% decline in bar and island area between 1910 and 1988 within a 22-km section. Dams, riprap, logging, and gravel mining may all be contributing to diminished bar formation rates. Removing obstacles to natural riparian forest creation mechanisms is necessary to regenerate the river-floodplain system and realize its productive potential. PMID:10552104

  7. Numerical simulation of overbank processes in topographically complex floodplain environments

    NASA Astrophysics Data System (ADS)

    Nicholas, A. P.; Mitchell, C. A.

    2003-03-01

    This article presents results from an investigation of the hydraulic characteristics of overbank flows on topographically-complex natural river floodplains. A two-dimensional hydraulic model that solves the depth-averaged shallow water form of the Navier-Stokes equations is used to simulate an overbank flow event within a multiple channel reach of the River Culm, Devon, UK. Parameterization of channel and floodplain roughness by the model is evaluated using monitored records of main channel water level and point measurements of floodplain flow depth and unit discharge. Modelled inundation extents and sequences are assessed using maps of actual inundation patterns obtained using a Global Positioning System, observational evidence and ground photographs. Simulation results suggest a two-phase model of flooding at the site, which seems likely to be representative of natural floodplains in general. Comparison of these results with previous research demonstrates the complexity of overbank flows on natural river floodplains and highlights the limitations of laboratory flumes as an analogue for these environments. Despite this complexity, frequency distributions of simulated depth, velocity and unit discharge data closely follow a simple gamma distribution model, and are described by a shape parameter () that exhibits clear systematic trends with changing discharge and floodplain roughness. Such statistical approaches have the potential to provide the basis for computationally efficient flood routing and overbank sedimentation models.

  8. Transport of micropollutants in a riverbank filtration system

    NASA Astrophysics Data System (ADS)

    van Driezum, Inge; Oudega, Thomas; Reiner, Philipp; Zessner, Matthias; Farnleitner, Andreas; Blaschke, Paul

    2014-05-01

    Groundwater locations at alluvial backwaters are essential for public water supply. Riverbank filtration (RBF) systems are widely used as a means of obtaining public water supplies. Riverbank filtration is an effective way to remove micropollutants from the receiving surface water. The efficiency of the RBF system strongly depends on the residence time of the water in the aquifer and on the soil properties (Ray, 2011). In order to understand all bio- and geochemical processes within the hyporheic zone (e.g. the region were mixing of surface water and groundwater occurs), exchange rates and flow patterns need to be quantified. The main study area covers the porous groundwater aquifer study site (PGWA) - an urban floodplain extending on the left bank of the River Danube downstream of the City of Vienna. It is one of the main groundwater bodies in Austria. Groundwater quality in the PGWA is influenced by a combination of anthropogenic activities, industry, wastewater treatment plants, heavy precipitation events and floodings. The upper layer of the DPA is impermeable, preventing pollution originating from the surface. The upper layer consists of silt. The underlying confined aquifer consists of sand and gravel layers. Hydraulic conductivities range from 5 x 10-2 m/s up to 5 x 10-5 m/s. Underneath the aquifer are alternating sand an clay/silt layers. Samples are taken from two transects in the DPA. These transects consist of four piezometers in the first few meters of the groundwater aquifer. Several other piezometers are placed downstream from the river-groundwater interface. The behaviour of the micropollutants in the hyporheic zone can therefore be studied intensively. The transport behaviour of several micropollutants is modeled using carbamazepine (CBZ) and acesulfame (ACE) as natural tracers. Furthermore, temperature and electrical conductivity data was used for modeling. The micropollutants are measured using an in house developed online SPE-HPLC-MS/MS method

  9. Coupling hydrological and impact assessment models to explore nutrient cycling in freshwater systems

    NASA Astrophysics Data System (ADS)

    Bouwman, Lex; van Beek, Rens; Beusen, Arthur; Mogollón, José; Middelburg, Jack

    2016-04-01

    The IMAGE-Global Nutrient Model (GNM) is a new globally distributed, spatially explicit model in which the hydrology model PCR-GLOBWB is coupled to the integrated assessment model IMAGE to simulate nitrogen (N) and phosphorus (P) delivery, and then with a spiraling ecological approach to simulating instream biogeochemistry. Routing the water with dissolved and suspended N and P from upstream grid cells occurs simultaneous with N and P delivery to water bodies within grid cells from diffuse and point sources (wastewater). IMAGE-GNM describes the following diffuse sources associated with the water flow: surface runoff, shallow and deep groundwater, riparian zones. Depending on the landscape features, all these flows may be present within one grid cell. Furthermore, diffuse N and P inputs occur through allochtonous organic matter inputs via litterfall in (temporarily) inundated river floodplains, and atmospheric deposition. In the spiraling concept, the residence time of the water and nutrient uptake velocity determine N and P retention in water bodies. Validation of model results with observations yields acceptable agreement given the global scale of the uncalibrated model. Sensitivity analysis shows shifts in the importance of the different sources, with decreasing importance of natural sources and increasing influence of wastewater and agriculture. IMAGE-GNM can be employed to study the interaction between society and the environment over prolonged time periods. Here we show results for the full 20th century.

  10. Temporal hydrological and hydrochemical behaviour of the regional discharge area of a carbonate system - why we can not see fast responses?

    NASA Astrophysics Data System (ADS)

    Bodor, Petra; Eröss, Anita; Kovács, József; Mádl-Szönyi, Judit

    2016-04-01

    The subsurface part of the hydrologic cycle, the saturated groundwater flow can be mostly studied in regional discharge areas. In these regions the water has already spent geologically long time under the surface, therefore the upwelling water reflect the effect of the geometry and boundary conditions of the whole flow field, its geology and chemical processes. According to these conditions, the discharging waters can be characterized with different values and variability of physicochemical parameters (temperature, total dissolved solids, cations, anions, gas content etc.). This question has special interest in carbonate systems where the concept of regional groundwater flow was only introduced in the last few years. Hydrographs and chemographs are frequently used in karst studies to demonstrate the effect of variability of the system and to derive information for the nature of flow inside the karst (channel, fracture or matrix). Usually these graphs show abrupt changes after precipitation events, but this is typical for epigenic karsts. However, discharge areas, where hypogenic karsts developed, can behave differently due to their feeding flow systems. These systems and their effects are not so well studied yet. In this study we examined hydrographs and chemographs of the regional discharge area of a deep and thick carbonate range of Buda Thermal Karst and tried to understand those mechanisms which determine the hydrological and hydrochemical behaviour of the region. Here cold, lukewarm and also thermal waters discharge along the River Danube. The variability of physicochemical parameters (temperature, electric conductivity, pH, volume discharge, water level, dissolved CO2 and 222Rn, δ18O, δD) of the discharging water was studied to understand influencing mechanisms. We tried to understand the effect of precipitation (short and long term) and the effect of River Danube with geomathematical methods for the lukewarm components of the discharging water. Based on

  11. Radar remote sensing for crop classification and canopy condition assessment: Ground-data documentation

    NASA Technical Reports Server (NTRS)

    Ulaby, F. T. (Principal Investigator); Jung, B.; Gillespie, K.; Hemmat, M.; Aslam, A.; Brunfeldt, D.; Dobson, M. C.

    1983-01-01

    A vegetation and soil-moisture experiment was conducted in order to examine the microwave emission and backscattering from vegetation canopies and soils. The data-acquisition methodology used in conjunction with the mobile radar scatterometer (MRS) systems is described and associated ground-truth data are documented. Test fields were located in the Kansas River floodplain north of Lawrence, Kansas. Ten fields each of wheat, corn, and soybeans were monitored over the greater part of their growing seasons. The tabulated data summarize measurements made by the sensor systems and represent target characteristics. Target parameters describing the vegetation and soil characteristics include plant moisture, density, height, and growth stage, as well as soil moisture and soil-bulk density. Complete listings of pertinent crop-canopy and soil measurements are given.

  12. A Sunken Ship of the Desert at the River Danube in Tulln, Austria

    PubMed Central

    Galik, Alfred; Mohandesan, Elmira; Forstenpointner, Gerhard; Scholz, Ute Maria; Ruiz, Emily; Krenn, Martin; Burger, Pamela

    2015-01-01

    Rescue excavations recovered a skeleton that resurrect the contemporary dramatic history of Austria in the 17th century as troops besieged Vienna in the second Osmanic-Habsburg war. Unique for Central Europe is the evidence of a completely preserved camel skeleton uncovered in a large refuse pit. The male individual of slender stature indicates a few but characteristic pathological changes revealing not a beast of burden but probably a valuable riding animal. Anatomical and morphometrical analyses suggest a hybrid confirmed by the ancient DNA analyses resulting in the presence of a dromedary in the maternal and a Bactrian camel in the paternal line. PMID:25831121

  13. Radiometric, SEM and XRD investigation of the Chituc black sands, southern Danube Delta, Romania.

    PubMed

    Margineanu, R M; Blebea-Apostu, Ana-Maria; Celarel, Aurelia; Gomoiu, Claudia-Mariana; Costea, C; Dumitras, Delia; Ion, Adriana; Duliu, O G

    2014-12-01

    The black sand of the Chituc marine sand bank, northern of the city of Navodari (Romania), presents anomalous high radioactivity. Field measurements recorded in some places dose rate up to 200 nSv/h, significantly overpassing the average value of 44 ± 20 nSv/h along the entire Southern sector of Romanian Black Sea shore. Gamma ray spectrometry performed on both Slanic-Prahova Underground Low Background Laboratory and Geological Institute of Romania Radiometric Facilities showed with clarity the dominance of (228)Ac radioisotope in the 50 microns fraction together with the (226)Ra and traces of (40)K. No significant amount of anthropogenic (137)Cs was identified. Based on radiometric as well as on SEM-EDAX and XRD determinations we come to the conclusion that the evidenced radioactivity could be attributed to both uranium and thorium series in the zircon and monazite fractions and to a lesser extent to potassium in the feldspars.

  14. A sunken ship of the desert at the river Danube in Tulln, Austria.

    PubMed

    Galik, Alfred; Mohandesan, Elmira; Forstenpointner, Gerhard; Scholz, Ute Maria; Ruiz, Emily; Krenn, Martin; Burger, Pamela

    2015-01-01

    Rescue excavations recovered a skeleton that resurrect the contemporary dramatic history of Austria in the 17th century as troops besieged Vienna in the second Osmanic-Habsburg war. Unique for Central Europe is the evidence of a completely preserved camel skeleton uncovered in a large refuse pit. The male individual of slender stature indicates a few but characteristic pathological changes revealing not a beast of burden but probably a valuable riding animal. Anatomical and morphometrical analyses suggest a hybrid confirmed by the ancient DNA analyses resulting in the presence of a dromedary in the maternal and a Bactrian camel in the paternal line.

  15. Basin-wide investigation of terrestrial biomarker source to sink transport along a major modern fluvial system

    NASA Astrophysics Data System (ADS)

    Freymond, C.; Peterse, F.; Filip, F.; Eglinton, T. I.

    2014-12-01

    Organic carbon discharged by rivers and buried in continental margin sediments represents an important carbon sink and a valuable record of information on past environmental variations on the continents. In this context, it is crucial to understand the sources of carbon in river basins and the factors that influence biomarker signals during transport from the continental source to the oceans. In this study, we adopt a source-to-sink approach where concentration and compositional variations in branched glycerol dialkyl glycerol tetraethers (brGDGTs), plant wax fatty acids and lignin phenols in fine-grained (<63 µm) riverbank sediment deposits from the Danube River are investigated. Using this multi-proxy approach, we seek to establish geochemical "fingerprints" of the largest tributaries and follow the evolution of these signatures along the course of the river, from headwater tributaries to its delta. Spatial trends in biomarker concentrations along the river transect are assessed by normalizing them on the mineral-specific surface area of the sediment. Surface area normalized brGDGT concentrations show a clear trend to decreasing values (ng brGDGT m-2) from the upper to the lower catchment. The distributions of brGDGTs, a group of soil bacterial membrane lipids that has been shown to record local environmental parameters, reflect the trend of increasing air temperature along the course of the Danube. This trend suggests an increasing contribution of soil organic carbon from tributaries with a more continental and warmer climate in the lower Danube basin to the OC that is finally delivered to the delta. More detailed insights into the evolution of the organic carbon composition within the Danube river basin will stem from compound-specific δD, δ13C and ultimately 14C measurements on terrestrial biomarkers in riverbank and suspended sediments.

  16. A meeting of the waters: interdisciplinary challenges and opportunities in tidal rivers

    USGS Publications Warehouse

    Ensign, Scott H.; Noe, Gregory B.; Hupp, Cliff R.; Fagherazzi, Sergio

    2012-01-01

    At the interface of estuarine tides and freshwater rivers lie wetland and aquatic ecosystems, which experience dramatic effects of sea level rise. There, nontidal channels and riparian floodplains are transforming into tidal ecosystems, and tidal freshwater ecosystems are receiving increasing salinity. These river-floodplain systems have both fluvial characteristics, including meandering channels and expansive floodplain forests, and estuarine characteristics, including tides and intertidal wetlands [see Barendregt et al., 2009; Conner et al., 2007, and references therein]. Because tidal rivers lie at the disciplinary divide between fluvial and estuarine science, a knowledge gap has developed in scientists' understanding of the geomorphic and biogeochemical response of these environments to sea level rise, climate change, and anthropogenically driven variations in watershed exports.

  17. Hydraulic Geometry and Microtopography of Tidal Freshwater Forested Wetlands and Implications for Restoration, Columbia River, U.S.A.

    SciTech Connect

    Diefenderfer, Heida L.; Coleman, Andre M.; Borde, Amy B.; Sinks, Ian A.

    2008-01-01

    The hydrologic reconnection of tidal channels, riverine floodplains, and main stem channels are among responses by ecological restoration practitioners to the increasing fragmentation and land conversion occurring in coastal and riparian zones. Design standards and monitoring of such ecological restoration depend upon the characterization of reference sites that vary within and among regions. Few locales, such as the 235 km tidal portion of the Columbia River on the West Coast U.S.A., remain in which the reference conditions and restoration responses of tidal freshwater forested wetlands on temperate zone large river floodplains can be compared. This study developed hydraulic geometry relationships for Picea sitchensis (Sitka spruce) dominated tidal forests (swamps) in the vicinity of Grays Bay on the Columbia River some 37 km from the Pacific Coast using field surveys and Light Detection and Ranging (LiDAR) data. Scaling relationships between catchment area and the parameters of channel cross-sectional area at outlet and total channel length were comparable to tidally influenced systems of San Francisco Bay and the United Kingdom. Dike breaching, culvert replacement, and tide gate replacement all affected channel cross-sectional geometry through changes in the frequency of over-marsh flows. Radiocarbon dating of buried wood provided evidence of changes in sedimentation rates associated with diking, and restoration trajectories may be confounded by historical subsidence behind dikes rendering topographical relationships with water level incomparable to reference conditions. At the same time, buried wood is influencing the development of channel morphology toward characteristics resembling reference conditions. Ecological restoration goals and practices in tidal forested wetland regions of large river floodplains should reflect the interactions of these controlling factors.

  18. Climatic, geomorphic, and archaeological implications of a late Quaternary alluvial chronology for the lower Salt River, Arizona, USA

    NASA Astrophysics Data System (ADS)

    Huckleberry, Gary; Onken, Jill; Graves, William M.; Wegener, Robert

    2013-03-01

    Recent archaeological excavations along the lower Salt River, Arizona resulted in the unexpected discovery of buried late Pleistocene soils and cultural features dating 5800-7100 cal YBP (Early Archaic), the latter representing the earliest evidence of human activity in the lower Salt River floodplain thus far identified. Because the lower Salt River floodplain has been heavily impacted by recent agriculture and urbanization and contains few stratigraphic exposures, our understanding of the river's geological history is limited. Here we present a late Quaternary alluvial chronology for a segment of the lower Salt River based on 19 accelerator mass spectrometry 14C and four optically stimulated luminescence ages obtained during two previous geoarchaeological investigations. Deposits are organized into allostratigraphic units and reveal a buried late Pleistocene terrace inset into middle-to-late Pleistocene terrace deposits. Holocene terrace fill deposits unconformably cap the late Pleistocene terrace tread in the site area, and the lower portion of this fill contains the Early Archaic archaeological features. Channel entrenchment and widening ~ 900 cal YBP eroded much of the older terrace deposits, leaving only a remnant of fill containing the buried latest Pleistocene and middle-to-late Holocene deposits preserved in the site area. Subsequent overbank deposition and channel filling associated with a braided channel system resulted in the burial of the site by a thin layer of flood sediments. Our study confirms that the lower Salt River is a complex mosaic of late Quaternary alluvium formed through vertical and lateral accretion, with isolated patches of buried soils preserved through channel avulsion. Although channel avulsion is linked to changes in sediment load and discharge and may have climatic linkages, intrinsic geomorphic and local base level controls limit direct correlations of lower Salt River stratigraphy to other large rivers in the North American

  19. Agricultural conversion of floodplain ecosystems: implications for groundwater quality.

    PubMed

    Schilling, Keith E; Jacobson, Peter J; Vogelgesang, Jason A

    2015-04-15

    With current trends of converting grasslands to row crop agriculture in vulnerable areas, there is a critical need to evaluate the effects of land use on groundwater quality in large river floodplain systems. In this study, groundwater hydrology and nutrient dynamics associated with three land cover types (grassland, floodplain forest and cropland) were assessed at the Cedar River floodplain in southeastern Iowa. The cropland site consisted of newly-converted grassland, done specifically for our study. Our objectives were to evaluate spatial and temporal variations in groundwater hydrology and quality, and quantify changes in groundwater quality following land conversion from grassland to row crop in a floodplain. We installed five shallow and one deep monitoring wells in each of the three land cover types and recorded water levels and quality over a three year period. Crop rotations included soybeans in year 1, corn in year 2 and fallow with cover crops during year 3 due to river flooding. Water table levels behaved nearly identically among the sites but during the second and third years of our study, NO₃-N concentrations in shallow floodplain groundwater beneath the cropped site increased from 0.5 mg/l to more than 25 mg/l (maximum of 70 mg/l). The increase in concentration was primarily associated with application of liquid N during June of the second year (corn rotation), although site flooding may have exacerbated NO₃-N leaching. Geophysical investigation revealed differences in ground conductivity among the land cover sites that related significantly to variations in groundwater quality. Study results provide much-needed information on the effects of different land covers on floodplain groundwater and point to challenges ahead for meeting nutrient reduction goals if row crop land use expands into floodplains. PMID:25687808

  20. Agricultural conversion of floodplain ecosystems: implications for groundwater quality.

    PubMed

    Schilling, Keith E; Jacobson, Peter J; Vogelgesang, Jason A

    2015-04-15

    With current trends of converting grasslands to row crop agriculture in vulnerable areas, there is a critical need to evaluate the effects of land use on groundwater quality in large river floodplain systems. In this study, groundwater hydrology and nutrient dynamics associated with three land cover types (grassland, floodplain forest and cropland) were assessed at the Cedar River floodplain in southeastern Iowa. The cropland site consisted of newly-converted grassland, done specifically for our study. Our objectives were to evaluate spatial and temporal variations in groundwater hydrology and quality, and quantify changes in groundwater quality following land conversion from grassland to row crop in a floodplain. We installed five shallow and one deep monitoring wells in each of the three land cover types and recorded water levels and quality over a three year period. Crop rotations included soybeans in year 1, corn in year 2 and fallow with cover crops during year 3 due to river flooding. Water table levels behaved nearly identically among the sites but during the second and third years of our study, NO₃-N concentrations in shallow floodplain groundwater beneath the cropped site increased from 0.5 mg/l to more than 25 mg/l (maximum of 70 mg/l). The increase in concentration was primarily associated with application of liquid N during June of the second year (corn rotation), although site flooding may have exacerbated NO₃-N leaching. Geophysical investigation revealed differences in ground conductivity among the land cover sites that related significantly to variations in groundwater quality. Study results provide much-needed information on the effects of different land covers on floodplain groundwater and point to challenges ahead for meeting nutrient reduction goals if row crop land use expands into floodplains.

  1. System of Earthquakes Alert (SEA) on the territory of Bulgaria developed as a result of DACEA project

    NASA Astrophysics Data System (ADS)

    Solakov, Dimcho; Dimitrova, Liliya; Simeonova, Stela; Aleksandrova, Irena; Stoyanov, Stoyan; Metodiev, Metodi

    2013-04-01

    The prevention of the natural disasters and the performing management of reactions to crisis are common problems for many countries. The Romania-Bulgaria border region is significantly affected by earthquakes occurred in both territories: on the one-hand, Vrancea seismic source, with intermediate-depth events and on the other hand, crustal seismicity recorded in the northern part of Bulgaria (Shabla, Dulovo, Gorna Orjahovitza). The general objective of DACEA (2010-2013) project is to develop an system of earthquake alert in order to prevent the natural disasters caused by earthquakes in the cross-border area, taking into account the nuclear power plants and other chemical plants located along the Danube on the territories of Romania and Bulgaria. An integrated warning system is designed and implemented in the cross-border area. A seismic detection network is put in operation in order to warn the bodies in charge with emergency situations management in case of seismic danger. The main purpose of this network is: • monitoring of the four seismogenic areas relevant for the cross-border area, in order to detect dangerous earthquakes • sending the seismic warning signals within several seconds to the local public authorities in the cross-border area On the territory of Bulgaria the seismic network belonging to SEA is consists of: • 8 seismic stations equipped with Basalt digitizer, accelerometer Epi-sensor and BB seismometer KS2000. • 8 seismic stations equipped with Basalt digitizer, accelerometer Epi-sensor, warning and visual monitoring equipment. The stations are spanned allover the North Bulgaria. The sites were thoroughly examined and the most important requirement was the low level of noise or vibrations. SEA centers were established both in Sofia (in National Institute of Geophysics, Geodesy and Geography - NIGGG) and Bucharest (in National Institute of Research and Development for Earth Physics). Both centers are equipped with servers for data analyses

  2. 6. GENERAL VIEW OF WESTERLY ELEVATION OF SPILLWAY; VIEW TO ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. GENERAL VIEW OF WESTERLY ELEVATION OF SPILLWAY; VIEW TO NORTHEAST FROM BLACKSTONE RIVER FLOODPLAIN. - Blackstone Canal Millbury Segment, Beginning northwest of State Route 146 & McCracken Road, running along west side of Route 146, Millbury, Worcester County, MA

  3. Solar system positioning system

    NASA Technical Reports Server (NTRS)

    Penanen, Konstantin I.; Chui, Talso

    2006-01-01

    Power-rich spacecraft envisioned in Prometheus initiative open up possibilities for long-range high-rate communication. A constellation of spacecraft on orbits several A.U. from the Sun, equipped with laser transponders and precise clocks can be configured to measure their mutual distances to within few cm. High on-board power can create substantial non-inertial contribution to the spacecraft trajectory. We propose to alleviate this contribution by employing secondary ranging to a passive daughter spacecraft. Such constellation can form the basis of it navigation system capable of providing position information anywhere in the soIar system with similar accuracy. Apart from obvious Solar System exploration implications, this system can provide robust reference for GPS and its successors.

  4. No-tillage system applied to the sunflower (hybrid pioneer PR64E83) resistant to the tribenuron-methyl in the conditions from Romania.

    PubMed

    Sarpe, Nicolae; Poienaru, Stefan; Maschio, Mirco

    2007-01-01

    In the year 2006, the first experience with the NO-TILLAGE system for sunflower crops was organized in Romania, using the Pioneer PR64E83 sunflower hybrid resistant to the tribenuron-methyl herbicide. The experience took place in the Danube river flood plain, on an alluvial soil with a content between 3.1-4.5% and a content of clay of 34-40%. In the conventional system, in the fall of the year 2005, autumn ploughing was carried out, along with harrowing, and in spring the land was tilled two more times, using both the disk and the harrow. Before sowing, the land was prepared by using the combiner-machine. After the sunflower sprouted, three-time mechanical hoeing between the rows, as well as three-time manual hoeing on the sunflower row were performed. In the no-tillage system, no autumn ploughing, nor any other soil work were performed, and the sunflower was sowed directly, by using the Gaspardo seeder. Before sowing, the soil was covered in proportion of 70% by species of weeds of the Cirsum, Sonchus and Polygonum amphibium type. To destroy these species of weeds, 3 days before sowing, the soil was treated with the Roundup herbicide in a dose of 7 litres/ha. After the sunflower sprouted, when the plants had 4-5 leaves, the following sulphonylurea herbicides were applied post-emergently. (1) Express 50SG--which contains tribenuron-methyl (2) Granstar 75DF--which contains 75% tribenuron-methyl (3) Titus 25DF--which contains 25% rimsulfuron (4) Mistral--which contains 40 g/L nicosulfuron (5) Lintur 70WG--which contains 4.1% triasulfuron + 65.9% dicamba (6) Peak 75WG--which contains 75% prosulfuron The Express 50SG and Granstar 75DF herbicides were selective for the sunflower hybrid PR64E83, and the other herbicides although belonging o the same sulphonylurea group, they proved to have a very phytotoxic effect upon the sunflower crop. In the report, selectivity is presented depending on the dose of herbicide, weed control and sunflower production.

  5. No-tillage system applied to the sunflower (hybrid pioneer PR64E83) resistant to the tribenuron-methyl in the conditions from Romania.

    PubMed

    Sarpe, Nicolae; Poienaru, Stefan; Maschio, Mirco

    2007-01-01

    In the year 2006, the first experience with the NO-TILLAGE system for sunflower crops was organized in Romania, using the Pioneer PR64E83 sunflower hybrid resistant to the tribenuron-methyl herbicide. The experience took place in the Danube river flood plain, on an alluvial soil with a content between 3.1-4.5% and a content of clay of 34-40%. In the conventional system, in the fall of the year 2005, autumn ploughing was carried out, along with harrowing, and in spring the land was tilled two more times, using both the disk and the harrow. Before sowing, the land was prepared by using the combiner-machine. After the sunflower sprouted, three-time mechanical hoeing between the rows, as well as three-time manual hoeing on the sunflower row were performed. In the no-tillage system, no autumn ploughing, nor any other soil work were performed, and the sunflower was sowed directly, by using the Gaspardo seeder. Before sowing, the soil was covered in proportion of 70% by species of weeds of the Cirsum, Sonchus and Polygonum amphibium type. To destroy these species of weeds, 3 days before sowing, the soil was treated with the Roundup herbicide in a dose of 7 litres/ha. After the sunflower sprouted, when the plants had 4-5 leaves, the following sulphonylurea herbicides were applied post-emergently. (1) Express 50SG--which contains tribenuron-methyl (2) Granstar 75DF--which contains 75% tribenuron-methyl (3) Titus 25DF--which contains 25% rimsulfuron (4) Mistral--which contains 40 g/L nicosulfuron (5) Lintur 70WG--which contains 4.1% triasulfuron + 65.9% dicamba (6) Peak 75WG--which contains 75% prosulfuron The Express 50SG and Granstar 75DF herbicides were selective for the sunflower hybrid PR64E83, and the other herbicides although belonging o the same sulphonylurea group, they proved to have a very phytotoxic effect upon the sunflower crop. In the report, selectivity is presented depending on the dose of herbicide, weed control and sunflower production. PMID:18399451

  6. Immune System

    MedlinePlus

    ... How Can I Help a Friend Who Cuts? Immune System KidsHealth > For Teens > Immune System Print A A ... could put us out of commission. What the Immune System Does The immune (pronounced: ih-MYOON) system, which ...

  7. Operating Systems.

    ERIC Educational Resources Information Center

    Denning, Peter J.; Brown, Robert L.

    1984-01-01

    A computer operating system spans multiple layers of complexity, from commands entered at a keyboard to the details of electronic switching. In addition, the system is organized as a hierarchy of abstractions. Various parts of such a system and system dynamics (using the Unix operating system as an example) are described. (JN)

  8. Parasite diversity and microsatellite variability in native and introduced populations of four Neogobius species (Gobiidae).

    PubMed

    Ondračková, M; Šimková, A; Civáňová, K; Vyskočilová, M; Jurajda, P

    2012-09-01

    Species introduced into new areas often show a reduction in parasite and genetic diversity associated to the limited number of founding individuals. In this study, we compared microsatellite and parasite diversity in both native (lower Danube) and introduced populations of 4 Ponto-Caspian gobies, including those (1) introduced from within the same river system (middle Danube; Neogobius kessleri and N. melanostomus), and (2) introduced from a different river system (River Vistula; N. fluviatilis and N. gymnotrachelus). Microsatellite data confirmed the lower Danube as a source population for gobies introduced into the middle Danube. Both native and introduced (same river system) populations of N. kessleri and N. melanostomus had comparable parasite species richness and microsatellite diversity, possibly due to multiple and/or continual migration/introduction of new individuals and the acquisition of local parasites. Reduced parasite species richness and microsatellite diversity were observed in introduced (different river system) populations in the Vistula. A low number of colonists found for N. fluviatilis and N. gymnotrachelus in the Vistula potentially resulted in reduced introduction of parasite species. Insufficient adaptation of the introduced host to local parasite fauna, together with introduction into an historically different drainage system, may also have contributed to the reduced parasite fauna. PMID:22814338

  9. European mustelids occupying pristine wetlands in the Danube delta harbor infections with trichinella likely derived from domesticated swine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although mustelids may play a significant role in the transmission of Trichinella spp., their protected status has limited opportunities to understand their exposure to parasites cycling either among domesticated or wildlife host species. Of the species of Trichinella in Europe, only T. britovi has ...

  10. A training network for introducing telemedicine, telecare and hospital informatics in the Adriatic-Danube-Black Sea region.

    PubMed

    Anogeianaki, Antonia; Ilonidis, George; Anogianakis, George; Lianguris, John; Katsaros, Kyriakos; Pseftogianni, Dimitra; Klisarova, Anelia; Negrev, Negrin

    2004-01-01

    DIMNET is a training mechanism for a region of central Europe. The aim is to upgrade the information technology skills of local hospital personnel and preserve their employability following the introduction of medical informatics. DIMNET uses Internet-based virtual classrooms to provide a 200-hour training course in medical informatics. Training takes place in the cities of Drama, Kavala, Xanthi and Varna. So far, more than 600 people have benefited from the programme. Initial results are encouraging. DIMNET promotes a new vocational training culture in the Balkans and is supported by local governments that perceive health-care as a fulcrum for economic development.

  11. Comprehensive Characteristics of Bottom Sediments of Water Bodies of Various Types in the Kiliya Delta of the Danube River

    EPA Science Inventory

    The "triad" approach, including analysis of the total content of toxicants, bioassay of bottom sediments, and the study of the structure of zoo- and phytobenthos communities, was used in assessing the quality of bottom sediments. It has been found that the studied bottom sediment...

  12. Crystal Systems.

    ERIC Educational Resources Information Center

    Schomaker, Verner; Lingafelter, E. C.

    1985-01-01

    Discusses characteristics of crystal systems, comparing (in table format) crystal systems with lattice types, number of restrictions, nature of the restrictions, and other lattices that can accidently show the same metrical symmetry. (JN)

  13. Systems Engineering

    NASA Technical Reports Server (NTRS)

    Pellerano, Fernando

    2015-01-01

    This short course provides information on what systems engineering is and how the systems engineer guides requirements, interfaces with the discipline leads, and resolves technical issues. There are many system-wide issues that either impact or are impacted by the thermal subsystem. This course will introduce these issues and illustrate them with real life examples.

  14. Delivery Systems.

    ERIC Educational Resources Information Center

    Hutchison, Betty

    This paper on delivery systems for preparing and training early childhood educators focuses on three main topics: (1) adequacy of delivery systems and access; (2) market influences on delivery systems; and (3) linking preparation and professional development components. Questions addressed include the following: Would the current preparation and…

  15. System Effectiveness

    SciTech Connect

    Powell, Danny H; Elwood Jr, Robert H

    2011-01-01

    An effective risk assessment system is needed to address the threat posed by an active or passive insider who, acting alone or in collusion, could attempt diversion or theft of nuclear material. It is critical that a nuclear facility conduct a thorough self-assessment of the material protection, control, and accountability (MPC&A) system to evaluate system effectiveness. Self-assessment involves vulnerability analysis and performance testing of the MPC&A system. The process should lead to confirmation that mitigating features of the system effectively minimize the threat, or it could lead to the conclusion that system improvements or upgrades are necessary to achieve acceptable protection against the threat. Analysis of the MPC&A system is necessary to understand the limits and vulnerabilities of the system to internal threats. Self-assessment helps the facility be prepared to respond to internal threats and reduce the risk of theft or diversion of nuclear material. MSET is a self-assessment or inspection tool utilizing probabilistic risk assessment (PRA) methodology to calculate the system effectiveness of a nuclear facility's MPC&A system. MSET analyzes the effectiveness of an MPC&A system based on defined performance metrics for MPC&A functions based on U.S. and international best practices and regulations. A facility's MC&A system can be evaluated at a point in time and reevaluated after upgrades are implemented or after other system changes occur. The total system or specific subareas within the system can be evaluated. Areas of potential performance improvement or system upgrade can be assessed to determine where the most beneficial and cost-effective improvements should be made. Analyses of risk importance factors show that sustainability is essential for optimal performance. The analyses reveal where performance degradation has the greatest detrimental impact on total system risk and where performance improvements have the greatest reduction in system risk

  16. Geothermal systems

    NASA Technical Reports Server (NTRS)

    Mohl, C.

    1978-01-01

    Several tasks of JPL related to geothermal energy are discussed. The major task is the procurement and test and evaluation of a helical screw drive (wellhead unit). A general review of geothermal energy systems is given. The presentation focuses attention on geothermal reservoirs in California, with graphs and charts to support the discussion. Included are discussions on cost analysis, systems maintenance, and a comparison of geothermal and conventional heating and cooling systems.

  17. [Information systems].

    PubMed

    Rodríguez Maniega, José Antonio; Trío Maseda, Reyes

    2005-03-01

    The arrival of victims of the terrorist attacks of 11 March at the hospital put the efficiency of its information systems to the test. To be most efficient, these systems should be simple and directed, above all, to the follow-up of victims and to providing the necessary information to patients and families. A specific and easy to use system is advisable. PMID:15771852

  18. CALUTRON SYSTEM

    DOEpatents

    Lawrence, E.O.

    1958-08-12

    A calutron system capable of functioning with only a portion of the separation tanks in the system operating is described. The invention is a calutron system comprssing a closed series of alternated tanks and electromagnets having a mid-yoke connecting intermediate positions of the series. dividing the series into twv-o portions, and thereby providing a closed magnetic path through either of the portions.

  19. Systemic darwinism.

    PubMed

    Winther, Rasmus Grønfeldt

    2008-08-19

    Darwin's 19th century evolutionary theory of descent with modification through natural selection opened up a multidimensional and integrative conceptual space for biology. We explore three dimensions of this space: explanatory pattern, levels of selection, and degree of difference among units of the same type. Each dimension is defined by a respective pair of poles: law and narrative explanation, organismic and hierarchical selection, and variational and essentialist thinking. As a consequence of conceptual debates in the 20th century biological sciences, the poles of each pair came to be seen as mutually exclusive opposites. A significant amount of 21st century research focuses on systems (e.g., genomic, cellular, organismic, and ecological/global). Systemic Darwinism is emerging in this context. It follows a "compositional paradigm" according to which complex systems and their hierarchical networks of parts are the focus of biological investigation. Through the investigation of systems, Systemic Darwinism promises to reintegrate each dimension of Darwin's original logical space. Moreover, this ideally and potentially unified theory of biological ontology coordinates and integrates a plurality of mathematical biological theories (e.g., self-organization/structure, cladistics/history, and evolutionary genetics/function). Integrative Systemic Darwinism requires communal articulation from a plurality of perspectives. Although it is more general than these, it draws on previous advances in Systems Theory, Systems Biology, and Hierarchy Theory. Systemic Darwinism would greatly further bioengineering research and would provide a significantly deeper and more critical understanding of biological reality. PMID:18697926

  20. Systemic darwinism.

    PubMed

    Winther, Rasmus Grønfeldt

    2008-08-19

    Darwin's 19th century evolutionary theory of descent with modification through natural selection opened up a multidimensional and integrative conceptual space for biology. We explore three dimensions of this space: explanatory pattern, levels of selection, and degree of difference among units of the same type. Each dimension is defined by a respective pair of poles: law and narrative explanation, organismic and hierarchical selection, and variational and essentialist thinking. As a consequence of conceptual debates in the 20th century biological sciences, the poles of each pair came to be seen as mutually exclusive opposites. A significant amount of 21st century research focuses on systems (e.g., genomic, cellular, organismic, and ecological/global). Systemic Darwinism is emerging in this context. It follows a "compositional paradigm" according to which complex systems and their hierarchical networks of parts are the focus of biological investigation. Through the investigation of systems, Systemic Darwinism promises to reintegrate each dimension of Darwin's original logical space. Moreover, this ideally and potentially unified theory of biological ontology coordinates and integrates a plurality of mathematical biological theories (e.g., self-organization/structure, cladistics/history, and evolutionary genetics/function). Integrative Systemic Darwinism requires communal articulation from a plurality of perspectives. Although it is more general than these, it draws on previous advances in Systems Theory, Systems Biology, and Hierarchy Theory. Systemic Darwinism would greatly further bioengineering research and would provide a significantly deeper and more critical understanding of biological reality.

  1. Power system

    DOEpatents

    Hickam, Christopher Dale

    2008-03-18

    A power system includes a prime mover, a transmission, and a fluid coupler having a selectively engageable lockup clutch. The fluid coupler may be drivingly connected between the prime mover and the transmission. Additionally, the power system may include a motor/generator drivingly connected to at least one of the prime mover and the transmission. The power-system may also include power-system controls configured to execute a control method. The control method may include selecting one of a plurality of modes of operation of the power system. Additionally, the control method may include controlling the operating state of the lockup clutch dependent upon the mode of operation selected. The control method may also include controlling the operating state of the motor/generator dependent upon the mode of operation selected.

  2. Saturn Systems.

    PubMed

    U Rehman, Habib; McKee, Nida A; McKee, Michael L

    2016-01-15

    Several ring systems (Saturn systems) have been studied using DFT methods that include dispersion effects. Comparison with X-ray structures are made with three systems, and the agreement is quite good. Binding enthalpies and binding free energies in dichloromethane and toluene have been computed. The effect of an encapsulated lithium cation is accessed by comparing C60 @(C6 H4 )10 and [Li@C60 @(C6 H4 )10 ](+). The [Li@C60 ](+) cation is a much better acceptor than C60 which leads to greater donor-acceptor interactions and larger charge transfer from the ring to [Li@C60 ](+).

  3. Saturn Systems.

    PubMed

    U Rehman, Habib; McKee, Nida A; McKee, Michael L

    2016-01-15

    Several ring systems (Saturn systems) have been studied using DFT methods that include dispersion effects. Comparison with X-ray structures are made with three systems, and the agreement is quite good. Binding enthalpies and binding free energies in dichloromethane and toluene have been computed. The effect of an encapsulated lithium cation is accessed by comparing C60 @(C6 H4 )10 and [Li@C60 @(C6 H4 )10 ](+). The [Li@C60 ](+) cation is a much better acceptor than C60 which leads to greater donor-acceptor interactions and larger charge transfer from the ring to [Li@C60 ](+). PMID:26096724

  4. Electronic system

    DOEpatents

    Robison, G H; Dickson, J F

    1960-11-15

    An electronic system is designed for indicating the occurrence of a plurality of electrically detectable events within predetermined time intervals. The system comprises separate input means electrically associated with the events under observation an electronic channel associated with each input means, including control means and indicating means; timing means adapted to apply a signal from the input means after a predetermined time to the control means to deactivate each of the channels; and means for resetting the system to its initial condition after the observation of each group of events. (D.L.C.)

  5. SAMPLING SYSTEM

    DOEpatents

    Hannaford, B.A.; Rosenberg, R.; Segaser, C.L.; Terry, C.L.

    1961-01-17

    An apparatus is given for the batch sampling of radioactive liquids such as slurries from a system by remote control, while providing shielding for protection of operating personnel from the harmful effects of radiation.

  6. Systems Analysis.

    ERIC Educational Resources Information Center

    Loucks, D. P.; Bell, J. M.

    1978-01-01

    Presents a literature review of the analysis of the administrative systems of various environmental programs related to water quality and pollution policy. A list of 70 references published in 1976 and 1977 is also presented. (HM)

  7. Microelectromechanical Systems

    NASA Technical Reports Server (NTRS)

    Gabriel, Kaigham J.

    1995-01-01

    Micro-electromechanical systems (MEMS) is an enabling technology that merges computation and communication with sensing and actuation to change the way people and machines interact with the physical world. MEMS is a manufacturing technology that will impact widespread applications including: miniature inertial measurement measurement units for competent munitions and personal navigation; distributed unattended sensors; mass data storage devices; miniature analytical instruments; embedded pressure sensors; non-invasive biomedical sensors; fiber-optics components and networks; distributed aerodynamic control; and on-demand structural strength. The long term goal of ARPA's MEMS program is to merge information processing with sensing and actuation to realize new systems and strategies for both perceiving and controlling systems, processes, and the environment. The MEMS program has three major thrusts: advanced devices and processes, system design, and infrastructure.

  8. Recommender systems

    NASA Astrophysics Data System (ADS)

    Lü, Linyuan; Medo, Matúš; Yeung, Chi Ho; Zhang, Yi-Cheng; Zhang, Zi-Ke; Zhou, Tao

    2012-10-01

    The ongoing rapid expansion of the Internet greatly increases the necessity of effective recommender systems for filtering the abundant information. Extensive research for recommender systems is conducted by a broad range of communities including social and computer scientists, physicists, and interdisciplinary researchers. Despite substantial theoretical and practical achievements, unification and comparison of different approaches are lacking, which impedes further advances. In this article, we review recent developments in recommender systems and discuss the major challenges. We compare and evaluate available algorithms and examine their roles in the future developments. In addition to algorithms, physical aspects are described to illustrate macroscopic behavior of recommender systems. Potential impacts and future directions are discussed. We emphasize that recommendation has great scientific depth and combines diverse research fields which makes it interesting for physicists as well as interdisciplinary researchers.

  9. Respiratory system

    NASA Technical Reports Server (NTRS)

    Bartlett, R. G., Jr.

    1973-01-01

    The general anatomy and function of the human respiratory system is summarized. Breathing movements, control of breathing, lung volumes and capacities, mechanical relations, and factors relevant to respiratory support and equipment design are discussed.

  10. Laser Systems

    NASA Technical Reports Server (NTRS)

    1985-01-01

    Tunable diode lasers are employed as radiation sources in high resolution infrared spectroscopy to determine spectral characteristics of gaseous compounds. With other laser systems, they are produced by Spectra-Physics, and used to monitor chemical processes, monitor production of quantity halogen lamps, etc. The Laser Analytics Division of Spectra-Physics credits the system's reliability to a program funded by Langley in the 1970s. Company no longer U.S.-owned. 5/22/97

  11. Systems and Components Fuel Delivery System, Water Delivery System, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Systems and Components - Fuel Delivery System, Water Delivery System, Derrick Crane System, and Crane System Details - Marshall Space Flight Center, F-1 Engine Static Test Stand, On Route 565 between Huntsville and Decatur, Huntsville, Madison County, AL

  12. Chaotic Systems

    NASA Astrophysics Data System (ADS)

    Myasishchev, Denis; Bixler, David

    2009-04-01

    Chaos theory is a current topic in physics research and is of great scientific and applied interest. Chaotic systems include weather patterns, genetic evolution and free market economics. Modeling chaotic phenomena using electronic circuits is a convenient way to analyze nonlinear systems. We have built various types of circuits and examined the conditions under which chaos occurs. Chua's circuit and analog computing circuits (ones that directly model systems of differential equations) were in the spotlight during the fall semester. An R-C phase space diagram for the Chua's circuit was constructed and the phase transitions were examined. Different analog computing circuits were built and the resulting attractors, attractor phases, and bifurcations were recorded. A mechanical system, the two block train model, is the current focus of study. The goal is to examine attractors produced by a mechanical system, a computer simulation, and a corresponding circuit in order to prove that the same experimental results can be obtained from different sources. This way if a mechanical system is too complicated to build, it can be substituted by a suitable circuit.

  13. Toxicological investigation and evaluation of drinking-water pollution caused by chemical wastes

    SciTech Connect

    Desi, I.; Somosi, G.

    1984-08-01

    Acute, subacute, in vitro, and animal experiments were performed in the spring and fall of 1981. In the course of these investigations, samples from bank-filtered drinking-water wells of Vac, a town along the Danube; from three neighboring observation wells; from water transported from the opposite side of the Danube; from a drinking-water well of a town farther northward; and from Danube water were examined. The aim of the study was to detect whether any of the water samples became contaminated by toxic chemicals. The drinking-water samples of the wells in Vac (Nos. 1-5) proved to be contaminated, and toxic effects of different degrees were also induced by other wells of Vac. The Danube water caused changes in some tests only; the control drinking-water well, the samples of the K3 observation well, and of the well on the opposite side of the Danube examined in the fall only did not cause any alterations. The toxicity was confirmed by the elevated hemolysis by the genotoxic effects on human erythrocytes and leukocytes, by the functional changes observed in the nervous system of rats, by alterations detected in the electric activity of the rats brains, in the learning ability and the behavior of the rats, by the increase in the cytochrome P-450 enzyme level of the liver, and by the chromosome aberrations emerging in mice. The changes were caused by different compounds of low and high boiling points escaping with water vapor or with organic solvents. On the basis of the investigations, the water proved to be inappropriate for human consumption.

  14. Systems Studies

    SciTech Connect

    Graham, R.L.

    1998-03-17

    The Systems Studies Activity had two objectives: (1) to investigate nontechnical barriers to the deployment of biomass production and supply systems and (2) to enhance and extend existing systems models of bioenergy supply and use. For the first objective, the Activity focused on existing bioenergy markets. Four projects were undertaken: a comparative analysis of bioenergy in Sweden and Austria; a one-day workshop on nontechnical barriers jointly supported by the Production Systems Activity; the development and testing of a framework for analyzing barriers and drivers to bioenergy markets; and surveys of wood pellet users in Sweden, Austria and the US. For the second objective, two projects were undertaken. First, the Activity worked with the Integrated BioEnergy Systems (TBS) Activity of TEA Bioenergy Task XIII to enhance the BioEnergy Assessment Model (BEAM). This model is documented in the final report of the IBS Activity. The Systems Studies Activity contributed to enhancing the feedstock portion of the model by developing a coherent set of willow, poplar, and switchgrass production modules relevant to both the US and the UK. The Activity also developed a pretreatment module for switchgrass. Second, the Activity sponsored a three-day workshop on modeling bioenergy systems with the objectives of providing an overview of the types of models used to evaluate bioenergy and promoting communication among bioenergy modelers. There were nine guest speakers addressing different types of models used to evaluate different aspects of bioenergy, ranging from technoeconomic models based on the ASPEN software to linear programming models to develop feedstock supply curves for the US. The papers from this workshop have been submitted to Biomass and Bioenergy and are under editorial review.

  15. Systemic fluoride.

    PubMed

    Sampaio, Fábio Correia; Levy, Steven Marc

    2011-01-01

    There is substantial evidence that fluoride, through different applications and formulas, works to control caries development. The first observations of fluoride's effects on dental caries were linked to fluoride naturally present in the drinking water, and then from controlled water fluoridation programs. Other systemic methods to deliver fluoride were later suggested, including dietary fluoride supplements such as salt and milk. These systemic methods are now being questioned due to the fact that many studies have indicated that fluoride's action relies mainly on its post-eruptive effect from topical contact with the tooth structure. It is known that even the methods of delivering fluoride known as 'systemic' act mainly through a topical effect when they are in contact with the teeth. The effectiveness of water fluoridation in many geographic areas is lower than in previous eras due to the widespread use of other fluoride modalities. Nevertheless, this evidence should not be interpreted as an indication that systemic methods are no longer relevant ways to deliver fluoride on an individual basis or for collective health programs. Caution must be taken to avoid excess ingestion of fluoride when prescribing dietary fluoride supplements for children in order to minimize the risk of dental fluorosis, particularly if there are other relevant sources of fluoride intake - such as drinking water, salt or milk and/or dentifrice. Safe and effective doses of fluoride can be achieved when combining topical and systemic methods.

  16. Systemic trauma.

    PubMed

    Goldsmith, Rachel E; Martin, Christina Gamache; Smith, Carly Parnitzke

    2014-01-01

    Substantial theoretical, empirical, and clinical work examines trauma as it relates to individual victims and perpetrators. As trauma professionals, it is necessary to acknowledge facets of institutions, cultures, and communities that contribute to trauma and subsequent outcomes. Systemic trauma-contextual features of environments and institutions that give rise to trauma, maintain it, and impact posttraumatic responses-provides a framework for considering the full range of traumatic phenomena. The current issue of the Journal of Trauma & Dissociation is composed of articles that incorporate systemic approaches to trauma. This perspective extends conceptualizations of trauma to consider the influence of environments such as schools and universities, churches and other religious institutions, the military, workplace settings, hospitals, jails, and prisons; agencies and systems such as police, foster care, immigration, federal assistance, disaster management, and the media; conflicts involving war, torture, terrorism, and refugees; dynamics of racism, sexism, discrimination, bullying, and homophobia; and issues pertaining to conceptualizations, measurement, methodology, teaching, and intervention. Although it may be challenging to expand psychological and psychiatric paradigms of trauma, a systemic trauma perspective is necessary on both scientific and ethical grounds. Furthermore, a systemic trauma perspective reflects current approaches in the fields of global health, nursing, social work, and human rights. Empirical investigations and intervention science informed by this paradigm have the potential to advance scientific inquiry, lower the incidence of a broader range of traumatic experiences, and help to alleviate personal and societal suffering.

  17. Systemic trauma.

    PubMed

    Goldsmith, Rachel E; Martin, Christina Gamache; Smith, Carly Parnitzke

    2014-01-01

    Substantial theoretical, empirical, and clinical work examines trauma as it relates to individual victims and perpetrators. As trauma professionals, it is necessary to acknowledge facets of institutions, cultures, and communities that contribute to trauma and subsequent outcomes. Systemic trauma-contextual features of environments and institutions that give rise to trauma, maintain it, and impact posttraumatic responses-provides a framework for considering the full range of traumatic phenomena. The current issue of the Journal of Trauma & Dissociation is composed of articles that incorporate systemic approaches to trauma. This perspective extends conceptualizations of trauma to consider the influence of environments such as schools and universities, churches and other religious institutions, the military, workplace settings, hospitals, jails, and prisons; agencies and systems such as police, foster care, immigration, federal assistance, disaster management, and the media; conflicts involving war, torture, terrorism, and refugees; dynamics of racism, sexism, discrimination, bullying, and homophobia; and issues pertaining to conceptualizations, measurement, methodology, teaching, and intervention. Although it may be challenging to expand psychological and psychiatric paradigms of trauma, a systemic trauma perspective is necessary on both scientific and ethical grounds. Furthermore, a systemic trauma perspective reflects current approaches in the fields of global health, nursing, social work, and human rights. Empirical investigations and intervention science informed by this paradigm have the potential to advance scientific inquiry, lower the incidence of a broader range of traumatic experiences, and help to alleviate personal and societal suffering. PMID:24617751

  18. Systemic fluoride.

    PubMed

    Sampaio, Fábio Correia; Levy, Steven Marc

    2011-01-01

    There is substantial evidence that fluoride, through different applications and formulas, works to control caries development. The first observations of fluoride's effects on dental caries were linked to fluoride naturally present in the drinking water, and then from controlled water fluoridation programs. Other systemic methods to deliver fluoride were later suggested, including dietary fluoride supplements such as salt and milk. These systemic methods are now being questioned due to the fact that many studies have indicated that fluoride's action relies mainly on its post-eruptive effect from topical contact with the tooth structure. It is known that even the methods of delivering fluoride known as 'systemic' act mainly through a topical effect when they are in contact with the teeth. The effectiveness of water fluoridation in many geographic areas is lower than in previous eras due to the widespread use of other fluoride modalities. Nevertheless, this evidence should not be interpreted as an indication that systemic methods are no longer relevant ways to deliver fluoride on an individual basis or for collective health programs. Caution must be taken to avoid excess ingestion of fluoride when prescribing dietary fluoride supplements for children in order to minimize the risk of dental fluorosis, particularly if there are other relevant sources of fluoride intake - such as drinking water, salt or milk and/or dentifrice. Safe and effective doses of fluoride can be achieved when combining topical and systemic methods. PMID:21701196

  19. Turbine system

    DOEpatents

    McMahan, Kevin Weston; Dillard, Daniel Jackson

    2016-05-03

    A turbine system is disclosed. The turbine system includes a transition duct having an inlet, an outlet, and a passage extending between the inlet and the outlet and defining a longitudinal axis, a radial axis, and a tangential axis. The outlet of the transition duct is offset from the inlet along the longitudinal axis and the tangential axis. The turbine system further includes a turbine section connected to the transition duct. The turbine section includes a plurality of shroud blocks at least partially defining a hot gas path, a plurality of buckets at least partially disposed in the hot gas path, and a plurality of nozzles at least partially disposed in the hot gas path. At least one of a shroud block, a bucket, or a nozzle includes means for withstanding high temperatures.

  20. Microbiology System

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Technology originating in a NASA-sponsored study of the measurement of microbial growth in zero gravity led to the development of Biomerieux Vitek, Inc.'s VITEK system. VITEK provides a physician with accurate diagnostic information and identifies the most effective medication. Test cards are employed to identify organisms and determine susceptibility to antibiotics. A photo-optical scanner scans the card and monitors changes in the growth of cells contained within the card. There are two configurations - VITEK and VITEK JR as well as VIDAS, a companion system that detects bacteria, viruses, etc. from patient specimens. The company was originally created by McDonnell Douglas, the NASA contractor.

  1. Complex Systems

    PubMed Central

    Goldberger, Ary L.

    2006-01-01

    Physiologic systems in health and disease display an extraordinary range of temporal behaviors and structural patterns that defy understanding based on linear constructs, reductionist strategies, and classical homeostasis. Application of concepts and computational tools derived from the contemporary study of complex systems, including nonlinear dynamics, fractals and “chaos theory,” is having an increasing impact on biology and medicine. This presentation provides a brief overview of an emerging area of biomedical research, including recent applications to cardiopulmonary medicine and chronic obstructive lung disease. PMID:16921107

  2. ELECTRONIC SYSTEM

    DOEpatents

    Robison, G.H. et al.

    1960-11-15

    An electronic system is described for indicating the occurrence of a plurality of electrically detectable events within predetermined time intervals. It is comprised of separate input means electrically associated with the events under observation: an electronic channel associated with each input means including control means and indicating means; timing means associated with each of the input means and the control means and adapted to derive a signal from the input means and apply it after a predetermined time to the control means to effect deactivation of each of the channels; and means for resetting the system to its initial condition after observation of each group of events.

  3. Computer systems

    NASA Technical Reports Server (NTRS)

    Olsen, Lola

    1992-01-01

    In addition to the discussions, Ocean Climate Data Workshop hosts gave participants an opportunity to hear about, see, and test for themselves some of the latest computer tools now available for those studying climate change and the oceans. Six speakers described computer systems and their functions. The introductory talks were followed by demonstrations to small groups of participants and some opportunities for participants to get hands-on experience. After this familiarization period, attendees were invited to return during the course of the Workshop and have one-on-one discussions and further hands-on experience with these systems. Brief summaries or abstracts of introductory presentations are addressed.

  4. Quasi-continuous and non-continuous archives in a floodplain setting. Detection, spatial distribution, and preservation potential.

    NASA Astrophysics Data System (ADS)

    Will, Mathias; Aalto, Rolf; Fuchs, Markus

    2015-04-01

    Fluvial deposition and erosion within a floodplain setting is heterogeneous in respect to its temporal and spatial distribution. Especially larger river systems with topographically heterogeneous floodplains show a large variability of influences on the transport and subsequent deposition sediment. But (depending on time scale) floodplains might still be able to tell a continuous story of (extreme) flooding events. This presentation discusses the potential of different topographic units as archives for fluvial processes in a floodplain setting along the Sacramento River floodplain (River Mile 175 - RM 195). This floodplain reach of the Sacramento River shows a large variety of topographic features, e.g. large ephemeral floodplain channels, elevated floodplains, channel scars, oxbow lakes, scour scars, large-scale annual inundation of the floodplain, and limited anthropogenic surface alterations. Therefore this setting provides an excellent opportunity to research the distribution of sedimentation processes on a floodplain. To decipher the distribution of quasi-continuous and non-continuous archives in this setting, high-resolution XS 210Pb profile analyses, and dating has been applied to approximately 80 shallow cores (~1m) within several landscape units to reconstruct deposition or erosion processes, rates, and frequency. With these high-resolution clay normalised adsorbed excess 210Pb (CNAXS) profiles it is not only possible calculate sedimentation rates, but also to detect and date relatively small (>3cm) deposition events with high precision (error ±4 to ±10 a) within the last century. Thus gaining insights on the potential of river floodplains as archives for extreme events. The analysis of the XS 210Pb profiles indicates that there are three categories of archives in the floodplain of the research area. (1) The majority of the sampling locations represent archives that are not suitable as for flood reconstructions, due to low sedimentation rates, frequent

  5. The use of historical maps for reconstructing landforms before river damming. The case of the Swiss Rhone River

    NASA Astrophysics Data System (ADS)

    Reynard, E.; Laigre, L.; Baud, D.

    2012-04-01

    The Swiss Rhone River was systematically embanked during the period 1864-1893. The Swiss Rhone River valley is a glacial valley filled by glaciolacustrine, fluvioglacial and fluvial sediments. Torrential tributaries contribute to a large extent to the sedimentation in the valley and have built large alluvial fans in the main valley. The period before the river damming corresponds to the Little Ice Age, and it is supposed that the torrential behaviour of the river and its tributaries was very active during that period. In parallel to a large hydraulic project (Third Rhone River Correction), aiming at enlarging the river for security and environmental reasons, this project aims at reconstructing the palaeogeomorphology of the river floodplain before and also during the 30-year long embankment project developed during the last decades of the 19th century. The objective is to better know the geomorphological behaviour of the river, and also to localize palaolandforms (meanders, braided patterns, sandstone dunes, wetlands, etc.), present in the floodplain in the first part of the 19th century and that have now totally disappeared. The project is carried out in close collaboration with the Cantonal Archives of Valais and with a group of historians working on the relations between the river and the communities. It should contribute to a better knowledge of the Swiss Rhone River history (Reynard et al., 2009). Both published official maps (Dufour maps, Siegfried maps) and unpublished maps and plans are systematically collected, digitized, and organised in a database managed by a Geographical Information System. Other data are collected (place names, geomorphological, hydrological and hydraulic data, information about land-use and vegetation, paintings and photographs, etc.) and localised. A high-resolution digital terrain model and areal photographs are also used and allow us to map palaeolandforms (meanders, filled oxbow lakes, former channels, etc.). In a second step

  6. System Dynamics

    NASA Astrophysics Data System (ADS)

    Morecroft, John

    System dynamics is an approach for thinking about and simulating situations and organisations of all kinds and sizes by visualising how the elements fit together, interact and change over time. This chapter, written by John Morecroft, describes modern system dynamics which retains the fundamentals developed in the 1950s by Jay W. Forrester of the MIT Sloan School of Management. It looks at feedback loops and time delays that affect system behaviour in a non-linear way, and illustrates how dynamic behaviour depends upon feedback loop structures. It also recognises improvements as part of the ongoing process of managing a situation in order to achieve goals. Significantly it recognises the importance of context, and practitioner skills. Feedback systems thinking views problems and solutions as being intertwined. The main concepts and tools: feedback structure and behaviour, causal loop diagrams, dynamics, are practically illustrated in a wide variety of contexts from a hot water shower through to a symphony orchestra and the practical application of the approach is described through several real examples of its use for strategic planning and evaluation.

  7. Systems Biology

    SciTech Connect

    Wiley, H S.

    2006-06-01

    The biology revolution over the last 50 years has been driven by the ascendancy of molecular biology. This was enthusiastically embraced by most biologists because it took us into increasingly familiar territory. It took mysterious processes, such as the replication of genetic material and assigned them parts that could be readily understood by the human mind. When we think of ''molecular machines'' as being the underlying basis of life, we are using a paradigm derived from everyday experience. However, the price that we paid was a relentless drive towards reductionism and the attendant balkanization of biology. Now along comes ''systems biology'' that promises us a solution to the problem of ''knowing more and more about less and less''. Unlike molecular biology, systems biology appears to be taking us into unfamiliar intellectual territory, such as statistics, mathematics and computer modeling. Not surprisingly, systems biology has met with widespread skepticism and resistance. Why do we need systems biology anyway and how does this new area of research promise to change the face of biology in the next couple of decades?

  8. Irrigation System

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Under contract with Marshall Space Flight Center, Midwest Research Institute compiled a Lubrication Handbook intended as a reference source for designers and manufacturers of aerospace hardware and crews responsible for maintenance of such equipment. Engineers of Lindsay Manufacturing Company learned of this handbook through NASA Tech Briefs and used it for supplemental information in redesigning gear boxes for their center pivot agricultural irrigation system.

  9. STAR System.

    ERIC Educational Resources Information Center

    Doverspike, James E.

    The STAR System is a developmental guidance approach to be used with elementary school children in the 5th or 6th grades. Two basic purposes underlie STAR: to increase learning potential and to enhance personal growth and development. STAR refers to 4 basic skills: sensory, thinking, adapting, and revising. Major components of the 4 skills are:…

  10. Bioconversion systems

    SciTech Connect

    Wise, D.L.

    1983-01-01

    The production of higher valued products from biomass is the focus of this reference and planning guide for those who deal with the demands of energy recovery. International experts explain the processes and potentials for genetic engineering to bioenergy systems, utilizing biomass lignin and producing chemicals from biomass using wet oxidation. They present studies of possible liquid fuel production in developing countries as well as information on new research and development such as an aquatic biomass growth system integrated with an anaerobic digestion system for producing fuel gas. Several chapters describe the use of forage crops as chemical feedstocks, production of chemicals from microalgae, and the technology and economics of chemicals from wood. CONTENTS: Fuels and Chemicals from Biomass: a Role for GeneSplicing Technology. Lactic Acid Production by Pure and Mixed Bacterial Cultures. Conversion of Lignin to Useful Chemical Products. Chemicals from Microalgae. Forage Crops as Chemical Feedstocks. Biomass Conversion into Chemicals Using Wet Oxidation. Technology and Economics of Chemicals from Wood. An Integrated Anaerobic Digestion System for the Production of Energy and Livestock Fleed Based on Aquatic Biomass Production on Sand Using Seawater Spray. Liquid Fuel Production from Biomass in the Developing Countries--an Agricultural and Economic Perspective, Part I--Introduction and Background. Part II--the Tropical Environment and the Availability of Suitable Land. Part III--Agricultural Properties of Energy Crops. Part IV--Economic Analysis of Liquid Fuel Options and Summary and Conclusions. Index.

  11. Systems Science

    ERIC Educational Resources Information Center

    Christakis, Alexander; Hammond, Debora; Jackson, Michael; Laszlo, Alexander; Mitroff, Ian; Snowden, Dave; Troncale, Len; Carr-Chellman, Alison; Spector, J. Michael; Wilson, Brent

    2013-01-01

    Scholars representing the field of systems science were asked to identify what they considered to be the most exciting and imaginative work currently being done in their field, as well as how that work might change our understanding. The scholars included Alexander Christakis, Debora Hammond, Michael Jackson, Alexander Laszlo, Ian Mitroff, Dave…

  12. Immune System

    EPA Science Inventory

    A properly functioning immune system is essential to good health. It defends the body against infectious agents and in some cases tumor cells. Individuals with immune deficiencies resulting from genetic defects, diseases (e.g., AIDS, leukemia), or drug therapies are more suscepti...

  13. Manufacturing Systems

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Advanced Process Systems designed a portable purge unit for NASA use. The unit is designed to protect flight and ground crews from toxic fumes and to provide a post-landing controlled environment for sensitive electronic equipment. Although the work has future spinoff potential, it has also led to a research and development program in conjunction with several universities.

  14. Systems