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Sample records for river-floodplain system danube

  1. Sources and composition of organic matter for bacterial growth in a large European river floodplain system (Danube, Austria)

    PubMed Central

    Besemer, Katharina; Luef, Birgit; Preiner, Stefan; Eichberger, Birgit; Agis, Martin; Peduzzi, Peter

    2010-01-01

    Dissolved and particulate organic matter (DOM and POM) distribution, lignin phenol signatures, bulk elemental compositions, fluorescence indices and microbial plankton (algae, bacteria, viruses) in a temperate river floodplain system were monitored from January to November 2003. We aimed to elucidate the sources and compositions of allochthonous and autochthonous organic matter (OM) in the main channel and a representative backwater in relation to the hydrological regime. Additionally, bacterial secondary production was measured to evaluate the impact of organic carbon source on heterotrophic prokaryotic productivity. OM properties in the backwater tended to diverge from those in the main channel during phases without surface water connectivity; this was likely enhanced due to the exceptionally low river discharge in 2003. The terrestrial OM in this river floodplain system was largely derived from angiosperm leaves and grasses, as indicated by the lignin phenol composition. The lignin signatures exhibited significant seasonal changes, comparable to the seasonality of plankton-derived material. Microbially-derived material contributed significantly to POM and DOM, especially during periods of low discharge. High rates of bacterial secondary production (up to 135 μg C L−1 d−1) followed algal blooms and suggested that autochthonous OM significantly supported heterotrophic microbial productivity. PMID:21151814

  2. 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

  3. Origin, enzymatic response and fate of dissolved organic matter during flood and non-flood conditions in a river-floodplain system of the Danube (Austria).

    PubMed

    Sieczko, Anna; Peduzzi, Peter

    2014-01-01

    Spectroscopic techniques and extracellular enzyme activity measurements were combined with assessments of bacterial secondary production (BSP) to elucidate flood-pulse-linked differences in carbon (C) sources and related microbial processes in a river-floodplain system near Vienna (Austria). Surface connection with the main channel significantly influenced the quantity and quality of dissolved organic matter (DOM) in floodplain backwaters. The highest values of dissolved organic carbon (DOC) and chromophoric DOM (CDOM) were observed during the peak of the flood, when DOC increased from 1.36 to 4.37 mg l(-1) and CDOM from 2.94 to 14.32 m(-1). The flood introduced DOC which consisted of more allochthonously-derived, aromatic compounds. Bacterial enzymatic activity, as a proxy to track the response to changes in DOM, indicated elevated utilization of imported allochthonous material. Based on the enzyme measurements, new parameters were calculated: metabolic effort and enzymatic indices (EEA 1 and EEA 2). During connection, bacterial glucosidase and protease activity were dominant, whereas during disconnected phases a switch to lignin degradation (phenol oxidase) occurred. The enzymatic activity analysis revealed that flooding mobilized reactive DOM, which then supported bacterial metabolism. No significant differences in overall BSP between the two phases were detected, indicating that heterogeneous sources of C sufficiently support BSP. The study demonstrates that floods are important for delivering DOM, which, despite its allochthonous origin, is reactive and can be effectively utilized by aquatic bacteria in this river-floodplain systems. The presence of active floodplains, characterized by hydrological connectivity with the main channel, creates the opportunity to process allochthonous DOC. This has potential consequences for carbon flux, enhancing C sequestration and mineralization processes in this river-floodplain system. PMID:24415892

  4. 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.

  5. Using Newspaper Coverage Analysis to Evaluate Public Perception of Management in River-Floodplain Systems

    NASA Astrophysics Data System (ADS)

    Hale, Brack W.

    2010-05-01

    Traditional natural resource management approaches often focus on a specific natural resource and ignore social components other than economic value. In contrast, new approaches to resource management, such as those employing ecosystem management strategies, recognize and strive to incorporate other social components of the managed system. This study uses a content analysis of regional newspaper coverage of two relatively new reserves in river-floodplain systems, the Lower Wisconsin State Riverway and the Middle Elbe Biosphere Reserve, to analyze each reserve’s success in managing the social components of its resources during each reserve’s first ten years. The results suggest that positive coverage of both reserves has increased, as has the perceived authority of the reserve staff, as measured by trends in the quantity of direct quotes. The Middle Elbe Biosphere Reserve received approximately three times more coverage than its Wisconsin counterpart, suggesting that the more extensive public outreach program of the former is an important tool in dealing with social issues within a conservation reserve.

  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. 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.

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

    PubMed

    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

  9. 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

  10. 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, ...

  11. 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

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

    PubMed Central

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

    2012-01-01

    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 ΔNH4+ as well as between ΔTP and ΔFe3 + 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 NH4+ and TP and the reduction of iron hydroxides leading to a concomitant release of Fe3 + 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 initially lead

  13. 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

  14. 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, ...

  15. 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.

  16. 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

  17. 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

  18. 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...

  19. 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

  20. 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

  1. 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.

  2. Modelling the effects of human disturbances on the flow and sediment dynamics of a large river floodplain.

    NASA Astrophysics Data System (ADS)

    Garcia, Marina; Basile, Pedro; Riccardi, Gerardo; Rodriguez, Jose F.

    2015-04-01

    The flow and sediment dynamics of large river floodplains can be substantially affected by human disturbances like bridges and embankments. These effects are difficult to predict, mainly due to extent of the domain over which they can be important. In this contribution we present the application of a quasi-2D unsteady flow and sediment transport model of a large lowland river system, including its floodplain. We study the potential impact of a 56-km long road embankment constructed across the entire floodplain. The study area comprises a 208-km reach of the Paraná River between the cities of Diamante and Ramallo (Argentina) representing total a river-floodplain area of 8,100 km². The model uses an unstructured cells scheme to solve the water flow and sediment equations, relying on different simplifications of the 1D de Saint Venant equations to define the discharge laws between cells. The simulations allow for the analysis of the spatially-distributed transport and deposition of fine sediments throughout the river-floodplain and the backwater effects introduced by the structures. These dynamic changes are quantified for different extraordinary flood events.

  3. 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.

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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.

  11. 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...

  12. 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.

  13. 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.

  14. 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.

  15. 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. PMID:12026988

  16. Geomorphology of the Trinity River floodplain in Dallas County, Texas

    NASA Astrophysics Data System (ADS)

    Haugen, B. D.; Roig-Silva, C.; Manning, A. R.; Harrelson, D. W.; Olsen, R. S.; Dunbar, J. P.; Pearson, M. L.

    2010-12-01

    Data from more than 1,800 geologic borings and over 500 cone penetrometer tests (CPTs) were used to characterize the geomorphology of the Trinity River floodplain in the Dallas Metropolitan Area. Historical maps, aerial photographs and other published information were used to prepare a preliminary geomorphic map. Boring logs and CPT data were then used to refine the preliminary map, produce a series of two-dimensional (2D) and three-dimensional (3D) cross sections, and interpret the recent geologic history of the area. Geomorphologic interpretations - most importantly the locations of paleo-channel deposits of sands and gravels - were used to identify reaches of the levees managed by the United States Army Corps of Engineers (USACE) and the City of Dallas that may be at significant risk for under-seepage. Boring logs and CPT data collected atop the levees were used to assess through-seepage risks. Local bedrock is comprised of cretaceous-age Eagle Ford Shale and Austin Chalk. Depth to bedrock in the study area averaged 14.6 m (47.8 ft). The uppermost surface of bedrock has been deeply incised by a meandering river. Vertical relief between the shallowest bedrock sections and deepest portion of the incised paleo-channel is more than 15 m (50 ft). In places the incised paleo-channel is more than 0.8 km (0.5 mi) wide. These data confirm the presence of an erosional unconformity between local bedrock and overlying quaternary floodplain deposits. The observed erosional unconformity is attributed to a higher-energy fluvial environment that occurred as a result of a drop in base level. Recent floodplain deposits consist of interlobate point bar, channel and overbank sediments that are generally distributed in a fining-upward sequence. Buried channel dimensions vary widely, but are more than 250 m (820 ft) in some areas - much larger than the current channel. A semi-continuous basal layer of quaternary sands and gravels approximately 2 to 5 m (7 to 16 ft) thick exists in

  17. 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.

  18. 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

  19. 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

  20. 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

  1. 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.

  2. 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

  3. 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

    2016-01-01

    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. PMID:27525952

  4. Opportunities for Monitoring Vegetation Structure in River Floodplains Using High-Resolution Satellite Data

    NASA Astrophysics Data System (ADS)

    Kooistra, Lammert; Romijn, Erika; Verrelst, Jochem

    2010-12-01

    Managers of large river catchments like the Rhine require regular information on the development of the vegetation structure in the river floodplains. The objective of this study was to develop a methodology for monitoring the location and structure properties of plant functional types in a river floodplain ecosystem using satellite-based multi-directional hyperspectral data. In this study we used data from the CHRIS sensor onboard the PROBA satellite acquired in 2005 over the test site Millingerwaard, a river floodplain ecosystem along the river Waal in the Netherlands. CHRIS data are particularly suitable for mapping vegetation structure because of its high spatial resolution (~17 m), spectral coverage (18 bands from 400 nm to 1050 nm) and angular sampling (5 viewing angles). Relevant vegetation structure properties such as leaf area index (LAI) and fractional cover (fCover) were quantified on a pixel-by-pixel basis by using the radiative transfer model FLIGHT that simulates canopy bidirectional reflectance by using Monte Carlo ray tracing. After classification of the nadir image into eight major land use classes, for three main classified plant functional types "herbaceous", "shrubs" and "forest", LAI and fCover maps were computed through model inversion of the CHRIS data. All three vegetation classes were modeled as a turbid medium in the 1D mode. LAI and fCover maps were computed for the nadir viewing direction. In order to assess the quality of the inversion, the resulting vegetation structure maps were validated with in situ LAI measurements that were collected using hemispherical photography and TRAC measurements. As a next step it will be assessed whether the inferred structural maps can be related to hydraulic roughness models and thereby leading to catchment-level water discharge capacity maps which can be used as input for modeling of future climate scenarios.

  5. 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...

  6. 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.

  7. 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

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

    NASA Astrophysics Data System (ADS)

    Faulkner, B. R.; Cline, S. P.; Landers, D. H.; Forshay, K. J.

    2008-12-01

    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 riparian forests and floodplain habitats. On the Green Island Restoration Site, north of the city of Eugene, several geomorphological features common to much of the Willamette floodplain are present. These features, ranging from young bare gravel bars, islands supporting mature forest stands, to agricultural areas bounded by levees. As part of a Memorandum of Understanding with the McKenzie River Trust, USEPA has constructed a network of fifty shallow monitoring wells on the Green Island site. Among the purposes are to characterize the hydrogeology of the multiple- island floodplain, the extent of hyporheic flow, and the temperature regime. The monitoring wells are located in areas ranging from a few meters from the river edge to several hundred meters away, within the agricultural areas. By automatic data-logging, flow nets will be developed using numerical modeling. Water quality data will be collected to measure the degee to which subsurface biogeochemistry is influenced by geomorphologic features that are determined by the processes of river channel migration, island formation, and colonization by riparian forest. The monitoring network will also be used to measure the groundwater quality effects of restoration projects currently underway. These include reforestation of previously agricultural areas, and levee removal.

  9. Aqueous accelerated solvent extraction of native polycyclic aromatic hydrocarbons (PAHs) from carbonaceous river floodplain soils.

    PubMed

    Yang, Yi; Hofmann, Thilo

    2009-10-01

    In this study, three river floodplain soils with different compositions of carbonaceous materials and a reference coal sample were extracted with water using the accelerated solvent extraction (ASE) method. The desorption enthalpy values for 2-ring PAHs were highest in the coal sample, with values in the soil samples decreasing with decrease in coal content. The values for the higher condensed PAHs showed that the highest desorption enthalpies were from the samples with the largest amount of coal-derived particles. Elevated desorption enthalpies indicated a strong bonding between PAHs and geosorbents. Moreover, with the application of ASE this study was able to conclude that the PAHs in the samples were preferentially adsorbed to carbonaceous materials with high surface areas. PMID:19524343

  10. 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.

  11. 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...

  12. Late Holocene evolution of the Bečva River floodplain (Outer Western Carpathians, Czech Republic)

    NASA Astrophysics Data System (ADS)

    Stacke, Václav; Pánek, Tomáš; Sedláček, Jan

    2014-02-01

    To reconstruct the geomorphic imprint of the anthropogenic and natural environmental changes in the Late Holocene, we studied the alluvial record of the Bečva River floodplain (Outer Western Carpathians, Czech Republic). Coring, geophysical sounding and lithological analysis of floodplain deposits supported by AMS (accelerator mass spectrometry) dating enabled the establishment of the primary evolutionary stages of Late Holocene floodplain evolution. During the Late Atlantic and Early Subboreal periods, gravel aggradation and braided environments occurred in the studied floodplain. The Late Subboreal and Early Subatlantic are characterised by overbank sedimentation, and the Middle Subatlantic is marked by the recurrence of gravel aggradation. A major incision phase took place during the Mediaeval Warm Period. The onset of overbank sedimentation in the 15th century correlated with ongoing deforestation of the lower parts of catchment, and colonisation of the mountain ridges during the 16th-17th centuries further accelerated this process. During the 20th century, reforestation of mountains and river-channel training resulted in a significant incision phase. Our data suggest that climate fluctuations were major driving factors for the morpho-sedimentary evolution of the floodplain approximately up to the 12th century, whereas in the latter evolution period, anthropogenic activity superseded natural factors. This transition occurred more than one millennium later than in other Central and Western European catchments.

  13. 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.

  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. PMID:25545280

  16. 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

  17. 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

  18. 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

  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. Arsenic species formed from arsenopyrite weathering along a contamination gradient in Circumneutral river floodplain soils.

    PubMed

    Mandaliev, Petar N; Mikutta, Christian; Barmettler, Kurt; Kotsev, Tsvetan; Kretzschmar, Ruben

    2014-01-01

    Arsenic is a toxic trace element, which commonly occurs as contaminant in riverine floodplains and associated wetlands affected by mining and ore processing. In this study, we investigated the solid-phase speciation of As in river floodplain soils characterized by circumneutral pH (5.7-7.1) and As concentrations of up to 40.3 g/kg caused by former mining of arsenopyrite-rich ores. Soil samples collected in the floodplain of Ogosta River (Bulgaria) were size-fractionated and subsequently analyzed using a combination of X-ray fluorescence (XRF) spectrometry, powder X-ray diffraction (XRD), X-ray absorption spectroscopy (XAS), and selective chemical extraction of poorly crystalline mineral phases. Arsenic and Fe were found to be spatially correlated and both elements were strongly enriched in the fine soil particle size fractions (<2 μm and 2-50 μm). Between 14 and 82% of the total As was citrate-ascorbate extractable. Molar As/Fe ratios were as high as 0.34 in the bulk soil extracts and increased up to 0.48 in extracts of the fine particle size fractions. Arsenic K-edge XAS spectra showed the predominance of As(V) and were well fitted with a reference spectrum of As(V) adsorbed to ferrihydrite. Whereas no As(III) was detected, considerable amounts of As(-I) were present and identified as arsenopyrite originating from the mining waste. Iron K-edge XAS revealed that in addition to As(V) adsorbed to ferrihydrite, X-ray amorphous As(V)-rich hydrous ferric oxides ("As-HFO") with a reduced number of corner-sharing FeO6 octahedra relative to ferrihydrite were the dominating secondary As species in the soils. The extremely high concentrations of As in the fine particle size fractions (up to 214 g/kg) and its association with poorly crystalline Fe(III) oxyhydroxides and As-HFO phases suggest a high As mobilization potential under both oxic and anoxic conditions, as well as a high bioaccessibility of As upon ingestion, dermal contact, or inhalation by humans or animals. PMID

  1. 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

  2. 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

  3. 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

  4. The impact of surface water exchange on the nutrient and particle dynamics in side-arms along the River Danube, Austria.

    PubMed

    Hein, Thomas; Baranyi, Christian; Reckendorfer, Walter; Schiemer, Fritz

    2004-07-26

    river floodplain systems. PMID:15207585

  5. 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

  6. 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

  7. 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.

  8. Characterization of habitats based on algal periphyton biomass in the upper Paraná River floodplain, Brazil.

    PubMed

    Leandrini, Ja; Fonseca, Ia; Rodrigues, L

    2008-08-01

    Considering the relevant role played by the hydrological regime on the structure and functioning of floodplains, this study aims at characterizing different types of aquatic environments according to periphyton biomass and evaluating the influence of the fluviometric levels of the Paraná River and other forcing functions upon the periphytic community. Periphyton (chlorophyll a) was analyzed in 28 habitats, during the years 2000 and 2001, in high and low water seasons. Both years were characterized by lacking the characteristic high water season. The Principal Components Analysis revealed two groups. The first component was positively associated with hydrometric level, electric conductivity, pH and transparency, and negatively with total nitrogen and total phosphorus, dissolved organic carbon and turbidity. The second component separated the habitats of Paraná River in the period of low waters from other environments, mainly for hydrometric level and high transparency values. Periphytic biomass of the habitats demonstrated that the maintenance of the functional integrity of the Upper Paraná River floodplain is closely related to its hydrologic cycle. PMID:18833470

  9. Using subsurface metazoan fauna to indicate groundwater-surface water interactions in the Nakdong River floodplain, South Korea

    NASA Astrophysics Data System (ADS)

    Bork, Jörg; Berkhoff, Sven E.; Bork, Sabine; Hahn, Hans Jürgen

    2009-02-01

    Hydrological interactions between surface water and groundwater (GW) can be described using hydrochemical and biological methods. Surface water-groundwater interactions and their effects on groundwater invertebrate communities were studied in the Nakdong River floodplain in South Korea. Furthermore, the GW-Fauna-Index, a promising new index for assessing the strength of surface-water influence on groundwater, was tested. The influence of surface water on groundwater decreased with increasing depth and distance from the river. While hydrochemistry prevailingly reflected the origin of the waters in the study area (i.e. whether alluvial or from adjacent rock), faunal communities seemed to display an affinity to surface-water intrusion. Fauna reacted quickly to changes in hydrology, and temporal changes in faunal community structure were significantly linked to the hydrological situation in the floodplain. The metazoan faunal community and the GW-Fauna-Index allow a distinction between surface and subsurface waters with varying degrees of exchange. The results indicate that hydrological conditions are reflected by faunal assemblages on a high spatiotemporal resolution, and that surface-water intrusion can be estimated using the GW-Fauna-Index.

  10. 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.

  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. New species of Tereancistrum Kritsky, Thatcher & Kayton, 1980 (Monogenea: Dactylogyridae: Ancyrocephalinae) from the gills of Prochilodus lineatus (Osteichthyes: Prochilodontidae) from the upper Paraná River floodplain, Brazil.

    PubMed

    Lizama, Maria de los Angeles P; Takemoto, Ricardo M; Pavanelli, Gilberto C

    2004-01-01

    Two new species of Tereancistrum Kritsky, Thatcher & Kayton, 1980 are described from the gills of Prochilodus lineatus (Prochilodontidae) collected from the upper Paraná River floodplain, Brazil. T. toksonum n. sp. is characterised by a slim ventral bar with a sclerotised membrane along the anterior margin. Another characteristic is the dorsal anchor with an elongated deep root. T. curimba n. sp. is similar to T. ornatus Kritsky, Thatcher & Kayton, 1980 but possesses a sclerotised structure between the accessory sclerites of the ventral anchors. Moreover, the accessory anchor sclerites of this new species are longer than those described for T. ornatus. PMID:14739674

  13. 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...

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. Heavy metal contaminants on the Elbe River floodplains - chances and limits to prediction of topsoil qualities

    NASA Astrophysics Data System (ADS)

    Krüger, F.; Urban, B.

    2009-04-01

    For decades to centuries the Elbe river lands have been highly polluted by heavy metals and organic micro pollutants due to uncontrolled and unlimited sewage disposal from settlements, industries, agriculture and contaminated sites. During high flood events polluted sediments are transported downstream and spread over the floodplains where they have caused severe large scale contamination. Recent sustainable agriculture on Elbe river grasslands requires site specific management, adapted to the degree of contamination. Due to different sedimentation rates and different historical contamination loads of pollutants, the status of soil contamination varies over time and between sites. As part of the RAMWASS project (Risk Assessment and Management of the Water-Sediment-Soil System, 6th EU research frame programme), a topsoil monitoring strategy was applied to the Lower-Saxony section of the Elbe River (Germany) which incorporates different flooding situations. In 2007, 66 topsoils were sampled along 21 cross sections within 11 meander loops. Up- and downstream, bankside and distant flooding environments were considered as well as different flooding frequences of sites. Measured soil parameters were heavy metals (Cd, Cr, Cu, Hg, Ni, Pb, Zn) arsenic, organic carbon, nitrogen, pH and grain size. Measured site parameters were elevation (flooding frequency) and distance to the Elbe from pollution source. Findings included arsenic values ranging from 17-165 mg/kg; cadmium, 0,5-11 mg/kg; and mercury, 0,1-20 mg/kg. More than 90 % of all investigated sites exceed legally allowed "threshold values" for mercury of 2 mg/kg for grassland use. The described monitoring strategy enables an assessment of large scale pollution. Multi-regression analyses were performed with selected parameters correlated to sedimentation processes to predict contamination status without heavy metal analysis, but with the help of easy assignable parameters as elevation, distance to the river from pollution

  20. 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

  1. 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

  2. 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

  3. 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

  4. 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.

  5. 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

  6. 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.

  7. 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

  8. 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

  9. Hydro blues on the Danube

    SciTech Connect

    Kovac, C.

    1997-03-24

    Armed with more than 10,000 pages of documents, Hungarian government representatives presented opening arguments earlier this month in a suit with neighboring Slovakia over environmental, financial and political impacts of a $2-billion hydroelectric project on the Danube River. The two countries` 20-year discord over the Gabcikovo-Nagymaros project has reached a new plateau in the legal battle now before the International Court of Justice in The Hague, The Netherlands. Following a two-week recess that began March 10, the court is set to hear arguments from Slovakia. The trial is expected to take six weeks, and will include an on-site inspection of the now-completed project by judges. The project includes a 15.5-mile-long diversion canal and a 720-Mw hydroelectric dam and power plant at Gabcikovo, now in Slovakia. Downstream in Hungary, Nagymaros Dam, with a 160-Mw powerplant, was to be built to halt surges from Gabcikovo. Hungary opted not to build the project.

  10. 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

  11. 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

  12. 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

    2015-01-01

    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. PMID:25966267

  13. 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.

  14. 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

  15. Inter-annual variations in the abundance of young-of-the-year of migratory fishes in the Upper Paraná River floodplain: relations with hydrographic attributes.

    PubMed

    Suzuki, H I; Agostinho, A A; Bailly, D; Gimenes, M F; Júlio, H F; Gomes, L C

    2009-06-01

    In this study, we identified and characterized the hydrographic attributes related to the success of recruitment of migratory fishes in the Upper Paraná River floodplain. To achieve our objectives, we analyzed inter-annual variations in the abundance of young-of-the-year (YOY; index of recruitment) of six migratory species and their relations with hydrographic attributes. Recruitment was related to the intensity, duration (in different fluviometrical levels), elasticity, number of pulses, greater uninterrupted overflow and delay of the floods (all obtained using the PULSO software). Collections of fish were conducted in the period between January 1987 and November 2007 in distinct environments (river channels, secondary channels and connected and disconnected floodplain lakes) distributed along three subsystems (Paraná, Baía and Ivinheima). Relations between recruitment and the attributes of interest were determined through analysis of covariance. In the studied period, the highest abundances of YOY were registered in 2007, followed by 1992, 1993, 2005 and 1988. The abundance of YOY was positively correlated with an intensity of high water levels (potamophase) and the duration of potamophase 1 and negatively with the duration of low water levels (limnophase) and a delay of flood. Higher hydrometric levels (540 and 610 cm for Paraná and 325 and 450 cm for Ivinheima) and greatest uninterrupted overflow presented different relations (significant interactions) among subsystems, but all with positive effects on recruitment. Results evidenced that recruitment responded better when floods started in January with potamophase intensities above 610 cm and water levels above 450 cm over a period of 50 days and repeated every two years (or > 610 cm for 38 days and repeated every two or three years). Therefore, artificial control of the floods at intervals of two or three years by manipulating the discharge of dams located upstream from the floodplain in a way that promotes

  16. Multiple lines of evidence risk assessment of American robins exposed to polychlorinated dibenzofurans (PCDFS) and polychlorinated dibenzo-P-dioxins (PCDDS) in the Tittabawassee River floodplain, Midland, Michigan, USA.

    PubMed

    Tazelaar, Dustin L; Fredricks, Timothy B; Seston, Rita M; Coefield, Sarah J; Bradley, Patrick W; Roark, Shaun A; Kay, Denise P; Newsted, John L; Giesy, John P; Bursian, Steven J; Zwiernik, Matthew J

    2013-06-01

    Concentrations of polychlorinated dibenzofurans (PCDFs) and polychlorinated dibenzo-p-dioxins (PCDDs) in Tittabawassee River floodplain soils and biota downstream of Midland, Michigan, USA, are greater than regional background concentrations. From 2005 to 2008, a multiple lines of evidence approach was utilized to evaluate the potential for effects of PCDD/DFs on American robins (Turdus migratorius) breeding in the floodplains. A dietary-based assessment indicated there was potential for adverse effects for American robins predicted to have the greatest exposures. Conversely, a tissue-based risk assessment based on site-specific PCDD/DF concentrations in American robin eggs indicated minimal potential for adverse effects. An assessment based on reproductive endpoints indicated that measures of hatch success in study areas were significantly less than those of reference areas. However, there was no dose-response relationship between that endpoint and concentrations of PCDD/DF. Although dietary-based exposure and reproductive endpoint assessments predicted potential for adverse effects to resident American robins, the tissue-based assessment indicates minimal to no potential for adverse effects, which is reinforced by the fact the response was not dose related. It is likely that the dietary assessment is overly conservative given the inherent uncertainties of estimating dietary exposure relative to direct tissue-based assessment measures. Based on the available data, it can be concluded that exposure to PCDD/DFs in the Tittabawassee River floodplain would not likely result in adverse population-level effects to American robins. PMID:23424046

  17. 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. PMID:21043263

  18. Organic Carbon Inventories and Vertical Fluxes Through the Vadose Zone into Groundwater at the Rifle, Colorado River Floodplain Site

    NASA Astrophysics Data System (ADS)

    Tokunaga, T. K.; Wan, J.; Dong, W.; Williams, K. H.; Robbins, M.; Kim, Y.; Faybishenko, B.; Conrad, M. E.; Christensen, J. N.; Gilbert, B.; Dayvault, R. D.; Long, P. E.; Hubbard, S. S.

    2013-12-01

    Understanding carbon inventories and fluxes within the vadose zone and groundwater of semi-arid regions is challenging because of their typically deep profiles, moderately low soil organic carbon (SOC) inventories, low dissolved organic carbon (DOC) fluxes, and slow changes in soil inorganic carbon (SIC) inventories. The remediated uranium/vanadium mill tailings site situated on a floodplain at Rifle, Colorado possesses a number of characteristics that facilitate investigation of subsurface carbon fluxes. These include locally derived fill soil having SOC and SIC concentrations representative of the region, established vegetation cover (perennial grasses and shrubs) on the fill, boundaries between the fill and underlying alluvium distinguishable through concentrations of SIC and other chemical components, predictable groundwater flow and interaction with the adjacent Colorado River, and a clearly delineated impermeable lower boundary (Wasatch Formation shale) at depths ranging from 6 to 7.5 m. Environmental characteristics of this site permit year-round sampling of both pore water and pore gas throughout most of the moderately deep (~ 3.5 m) vadose zone. Within this well-defined hydrological system, we recently installed a suite of tensiometers, pore water (vadose zone and groundwater) samplers, gas samplers, and neutron probe access tubes at three sites along a transect aligned with the groundwater flow direction in order to determine inventories and fluxes of water, carbon, and other components. The tensiometer and piezometer measurements are revealing impacts of infiltration and groundwater recharge events, evapotranspiration, and capillary fringe-groundwater interactions. The results of pore water analyses are showing relatively high concentrations of DOC (up to 4 mM) in the vadose zone, and particulate organic carbon (POC) mobile in the capillary fringe. Differences in DOC characteristics are being determined using a variety of analytical techniques. Hydraulic

  19. Shoreface morphodynamics along the Danube Delta coast

    NASA Astrophysics Data System (ADS)

    Tatui, Florin; Vespremeanu-Stroe, Alfred

    2015-04-01

    The shoreface has an important long-term contribution to the coastal sediment budget as it behaves as either a sink or source of sediment from/to the active zone (Hinton and Nicholls, 2007). Hence, it modulates the long-term shoreline movement. However, the shoreface behaviour remains poorly understood and such studies are scarce especially because of the lack of extensive long-term good-quality data. The objective of this study is to examine and explain the shoreface morphodynamics along the Danube Delta coast. The shoreface morphodynamics has been investigated over the medium- and large-scales (decades to centuries). This is a wave-dominated, low-lying coastline interrupted by river mouths and, sometimes, by engineering structures (jetties). This work uses historical and modern maps (since 1856) and bathymetrical measurements (2008 and 2014) extending along the whole Danube Delta coast (both Romanian and Ukrainian sectors) to water depths of approximately 20 m; sectorial seasonal and annual bathymetries of the upper shoreface (2003 - 2014); LIDAR data (2011), recent high resolution satellite images, ortophotos and GPS surveys for shoreline extraction, which were comparatively analysed (volume changes, profile to profile evolution) by means of GIS techniques in order to explain the morphological and volumetric evolution of the shoreface. The large scale coastal behaviour of Danube Delta coast (expressed in terms of shoreface sediment volume and spatial distribution pattern of cells) is linked to climatic forcings (storminess), Danube river sediment supply changes, longshore sediment transport distribution and impact of hard coastal engineering structures. Significant increase of shoreface volume in the last century is related to active deltaic lobes (Chilia) or developing barrier islands (Sacalin), while decreasing shoreface volumes are related to the presence of Sulina jetties which blocked the longshore sediment transport and induced severe erosion downdrift. In

  20. 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

  1. 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.

  2. The Distributuion BSR and Multiple BSR Across The Danube Delta on the Offshore Romania and Bulgaria

    NASA Astrophysics Data System (ADS)

    Atgin, Orhan; Cifci, Gunay; Dondurur, Derman; Bialas, Jorg; Klaucke, Ingo

    2015-04-01

    Danube river which flows into the Black Sea is one of the world's biggest amount sediment transporter to the marine environment. Throughout long geological periods, Danube has formed many channel structures and the channel developments are still being continuened. Danube River has caused a lot of potential gas hydrate formations which spread over quite larger areas. Under the frame of SUGAR Project, high resolution multichannel seismic data were collected using the facilities of Seismic Laboratory (SeisLab) in the Institute of Marine Sciences and Technology of Dokuz Eylül University on board R/V Maria S. Merian in 2013. More then 2300 km Multichannel seismic reflection data acquired across the palaeo Danube delta to investigate BSR and potential gas hyrdate areas on the continental shelf where Danube river reaches to the Black Sea, BSR areas and potential gas hyrdates. Also, in relation with high sediment input, the effects of deltas on BSR's are aimed to research and several of inactive and partly buried channel systems could be mapped. There are large number of buried channel levee systems which seem to underlain by a continuous BSR indicating availability of free gas. There are also a significant reflector of inverted polarity was identified within a depth of about 100 m below seafloor. A very prominent BSR with reversed polarity is determined 200 ms TWT below seafloor on the eastern levee of the channel and simulate and crosscut the sediment layer. Three distinct BSRs as multiple BSR signature are observed on the high resolution multichannel seismic with a slightly varying dips. Multiple BSR's up to 5 BSRs are exist around river channels and paleochannels which have formed during different geological periods. In some paleochannel areas, high amount of sediment transportation causes dissolution of gashyrdate structures. At such areas seismic signals are being absorbed and structures which indicate dissolved gas are determined. In addition parasound data show

  3. Monitoring Artificial Tracer Stones at the Danube East of Vienna

    NASA Astrophysics Data System (ADS)

    Liedermann, Marcel; Gerstl, Margit; Trithart, Michael; Habersack, Helmut

    2010-05-01

    The Integrated River Engineering Project on the Danube to the East of Vienna aims to implement innovative measures to stop riverbed incision on one of the last free flowing sections of the Austrian Danube River. In order to reduce erosion processes, it is planned to add larger gravel sizes within the natural grain size spectrum (granulometric bed improvement). It is planned to superimpose a layer of 25 cm thickness to reduce sediment discharge to a minimum of 10 to 15% of the current amount, but not to stop it entirely. Additionally seven huge sidearm systems will be reconnected, about 30% of the bank protection will be removed and low flow regulation structures will be improved in order to enhance the ecological situation. Within the scope of this Project a comprehensive sediment monitoring program is implemented. Besides bedload transport measurements using a basket sampler and sediment transport modelling applying a newly designed numerical model, artificial stones were added and monitored in order to observe transport velocities and initiation of motion. For the monitoring performed at the three kilometer long test reach near Hainburg, 40 artificial stones of three different sizes (intermediate b-axis: 23 mm, 40 mm, 70 mm) were produced and a coded radio acoustic transmitter was attached to each gravel. The stones were lowered to the river bed at six different locations at the beginning of the test reach, at a gravel bar and in a groyne field within the stretch. The positions of the stones have been observed about once a week, depending on hydrology, over a whole year including a HQ15 flood event. The positions of the stones have been determined by radio tracking from a boat. Hence transport paths and velocities as well as the initiation of bedload transport could be monitored. The paper gives an overview on the methodology and presents results of the monitoring program. The observed stones showed a size selective behaviour in transport. At all discharges

  4. Evolution of the Danube Deep-Sea Fan since the Last Glacial Maximum: insights into water level fluctuations in the Black Sea

    NASA Astrophysics Data System (ADS)

    Constantinescu, Adriana-Maria; Toucanne, Samuel; Dennielou, Bernanrd; Jorry, Stephan; Panin, Nicolae; Lericolais, Gilles

    2014-05-01

    The Danube deep-sea fan is one of the most extensive deep-sea sedimentary systems in Europe. It lies in the base of slope of the north-western margin of the Black Sea, in front of Viteaz Canyon. Since the work of Popescu (2002) the detailed morphology and architecture of the fan is well known. During lowstand periods, the fan was fed by the Viteaz Canyon, which was directly connected to the Danube River. The fan has developed an impressive channel-levees network which is characterized by seven major channel avulsions (Popescu, 2002, Lericolais et al., 2013). Despite the numerous sedimentary cores retrieved during the Blason (1998, 2002) and Assemblage (2004) oceanographic cruises, the details of the factors controlling the turbiditic activity of the Danube deep-sea fan still remained largely unknown. The purpose of our study is to improve the chronology of the Danube deep-sea fan and to tie the expected results to the recent findings obtained by Soulet et al. (2011) regarding the chronostratigraphy and environmental changes in the Black Sea since the Last Glacial Maximum (~26-19 kyr before present). Seven küllenberg cores, retrieved from along the Viteaz Canyon and the deep depositional system, were analysed through detailed visual description, X-ray radiographs, spectrocolorimetry and X-Ray Fluorescence (XRF) scanner analysis. These analyses allow core-to-core correlation and the recognition of the well-known sedimentary units of Degens and Ross (1972; lacustrine and marine units) and Major et al. (2002; Red Layers), while using the revisited chronology of Soulet et al. (2011). Sediment accumulation rates and turbidite frequency were then determined, revealing a shift in the sedimentation activity from the southern channel-levee system (Unit 3; Lericolais et al., 2013) to the northern channel-levee system (Unit 6; Lericolais et al., 2013) after the deposition of the so-called Red Layers 15,700 +/-300 yr ago and before the onset of the Bölling-Alleröd (14,700 yr

  5. 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.

  6. Real-time application of meteorological ensembles for Danube flood forecasting

    NASA Astrophysics Data System (ADS)

    Csík, A.; Gauzer, B.; Gnandt, B.; Balint, G.

    2009-04-01

    Flood forecasting schemes may have the most diverse structure depending on catchment size, response or concentration time and the availability of real time input data. The centre of weight of the hydrological forecasting system is often shifted from hydrological tools to the meteorological observation and forecasting systems. At lowland river sections simple flood routing techniques prevail where accuracy of discharge estimation might depend mostly on the accuracy of upstream discharge estimation. In large river basin systems both elements are present. Attempts are made enabling the use of ensemble of short and medium term meteorological forecast results for real-time flood forecasting by coupling meteorological and hydrological modelling tools. The system is designed in three parts covering the upper and central Danube. The large number of nodes (41) makes the system in fact semi distributed in basin scale. All of the nodes are prepared for forecast purposes. Real time mode runs are carried out in 6 hourly time steps. The available meteorological analysis and forecasting tools are linked to the flood forecasting system. Meteorological forecasts include 6 days and 12 days out of the ECMWF 10-14-day ahead EPS and VarEPS. The hydrological side of the system includes the data ingestion part producing semi distributed catchment wise input from gridded fields and rainfall-runoff, flood routing modules. Operational application of the of the ensemble system has been studied by the comparison of real time deterministic forecast and the experimental real time ensemble forecast results since the summer of 2008 on the river Danube. The period of June-October 2008 included mostly low water period interrupted by smaller floods. The real time ensemble hydrological forecasting experiment proved that the use of meteorological ensembles to produce sets of hydrological predictions increased the capability to issue forecasts with describing current uncertainties. As the result of the

  7. 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.

  8. 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.

  9. The negative relief of large river floodplains

    NASA Astrophysics Data System (ADS)

    Lewin, John; Ashworth, Philip J.

    2014-02-01

    Large floodplains have multiple and complex negative relief assemblages in which depressions fall below local or general floodplain surfaces at a variety of scales. The generation and dynamics of negative relief along major alluvial corridors are described and compared. Such depressions are significant for the storage and passage of surface waters, the creation of a range of riparian, wetland, lacustrine and flowing-water habitats, and the long-term accumulation of organic materials.

  10. 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.

  11. 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

  12. 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

  13. The Danube--a European Cultural Route. Report of the European Teachers' Seminar (66th, Donaueschingen, Germany, November 21-26, 1994).

    ERIC Educational Resources Information Center

    Scheichl, Andrea

    The 66th Council of Europe Teacher's Seminar focused on the Danube as actual and symbolic thoroughfare of European culture and ways to use it for teaching purposes. Presentations included: "Introductory Talk on 'The Danube'" (Andrea Scheichl); "The Danube, with Particular Reference to the Austrian Section" (Hans Trsek); "The Danube as a Commercial…

  14. 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

  15. The Danube Mappation of Hungary (1823-45) and its georeferencing method

    NASA Astrophysics Data System (ADS)

    Mészáros, János

    2010-05-01

    The sheets of the Danube Mappation were surveyed between 1823 and 1845, leading by the Management of Water and Construction. The leader-engineers were Mátyás Huszár, Pál Vásárhelyi and finally Ottó Ferenc Hieronymi. It shows the Danube and its riverside very accurately from Dévény (now Devín in Slovakia) to Pétervárad (now Petrovaradin in Serbia). The map represents the river itself, as well as the streets of towns and villages, steeples, small streams and canals, forests and the specialized signs of water measurement. The map was drawn on sheets with a size of 28×22 Viennese inches. Its scale is 1 Viennese inch to 50 Viennese fathoms that is 1:3600 in metric system. Therefore the dimension of one sheet is 1400×1100 Viennese fathoms on terrain. In metric system it is 2655,077376×2086,132224 m. The coordinates was described in Cassini projection. The central point of the coordinate system was the old observatory of the Gellérthegy in Buda (now Budapest in Hungary). The ellipsoid which had been used for the triangulation was the Zach-Oriani combined ellipsoid. The georeferencing of map sheets is based on the sheet labelling system. It shows the location of the individual sheets from the central point, so the coordinates of the corners for all map sheets had been calculated. The error of georeferenced mosaic is between 5-10 meters.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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. PMID:26745300

  1. 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

  2. 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.

  3. Characterization of the Danube River sediments using the PMF multivariate approach.

    PubMed

    Comero, Sara; Vaccaro, Stefano; Locoro, Giovanni; De Capitani, Luisa; Gawlik, Bernd Manfred

    2014-01-01

    Chemical composition data for the Danube River and its tributaries sediments were analyzed using positive matrix factorization (PMF). The objective was to identify both natural and anthropogenic sources affecting Danube Basin. During the Joint Danube Survey 2 (JDS2) campaign 148 bottom sediments samples were collected. The following elements were analyzed using the X-ray fluorescence technique: Al, As, Ca, Cd, Cl, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, Pb, S, Si, Ti, V and Zn. Mercury was determined by cold vapour atomic absorption spectrometry. Three factors were obtained considering the whole dataset (Danube and tributaries), identified as: (i) carbonate component characterized by Ca and Mg; (ii) alumino-silicate component dominated by Si and Al content and the presence of some metals attributed to natural processes; (iii) anthropogenic source identified by Hg, S, P and some heavy metals load. To better characterize the role of tributaries, the Danube and tributaries datasets, were also analyzed separately. The same three factor structures were identified in the Danube dataset. For the tributaries, a four-factor source model gave one further factor dominated by S and P, which could be attributed to the use of fertilizers in agriculture. PMID:24120015

  4. Influence of environmental factors on the geomorphologic support in Maritime Danube Delta

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

    This study aims to present the main aspects of the influence of environmental factors in the maritime part of Danube Delta, in the context of the impact on the geomorphologic support. The evolution of environmental factors impact is exponentially increasing in recent years, mapping out the complexity of the Delta system. Analysis of the impact of these factors on the evolution of geomorphologic support is relevant if the system analysis is done in an integrated way. In this context, this research presents in detail the interaction between the elements of the environment and maritime delta complex geomorphologic evolution. The approach provides a concrete example of systemic modeling through a multi-criteria methodology, systematically introducing and changing the impact of environmental factors in the deltaic system. Analyzing with the environmental factors (abiotic, biotic and anthropogenic) was noticed a high level of synergies between their components and the deltaic support-with relevant observations on the geomorphology of the study area. Soil science, geomorphology, hydrology etc. are geographical subjects that are used in applied sciences, considering the anthropogenic pressure regarding spatial planning and regional development. The precise knowledge of the vulnerability of land provides delineation, spatial location of areas with different degrees of exposure. Thus opens another direction regarding the practical knowledge of the environment and relief in which the maps receives analytic and practical valences and the geographical sciences proves their social usefulness. In order to determine the impact of the chosen factors (climate - temperature, rainfall etc, geomorphologic - exposure, slope etc, soil - texture, salinity etc, biotic - habitat, species etc, anthropogenic - embankments, irritations etc) on the geomorphologic support of the maritime Danube Delta, the analysis was based on detailed maps (both historical and actual like the Digital Terrain

  5. 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

  6. 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

  7. 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

  8. 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

  9. May cause environmental damage the diversion of the Danube in the Szigetköz area, Hungary?

    NASA Astrophysics Data System (ADS)

    Novak, Brigitta

    2009-04-01

    Summary The floodplain area between the main channel of Danube and its branch river Mosoni-Duna is called the Szigetköz. This wetland area has special flora and fauna, and it is a natural protection area. Underneath of the Szigetköz, there are a thick (several hundreds meters) sedimentary sequence, the so called Kisalföld Quaternary Aquifer. This aquifer system is fed by the surface river system of Danube and supplies excellent quality drinking water for several hundred thousands of people in Hungary and Slovakia. The Szigetköz Monitoring Network was established in 1991 to describe the environmental effects of the Bős-Nagymaros Dam System, which was partly built in 1992 on the Slovakian part of the Danube. The dam diverts three-quarter of the Danube runoff to a 40 km long artificial concrete channel north of the original river bed. The effect of this diversion is spectacular on the wetland area. Water level in the meandering channels have decreased significantly, part of the wetland area frequently becomes dry. The natural flow pattern has disappeared. As a consequence, the channel characteristics of the river network, therefore the flow pattern, the quantity and quality of surface and subsurface water on the upper region of the Danube have significantly changed. The aim of our research is to describe the relationship between surface water and groundwater and considering the variable geology of the area, to describe trends in chemistry and to find the possible reasons for extreme values. Also to detect possible connection between the extreme values and the changes in flow pattern caused by the human intervention. Water sample pairs from surface water and shallow and deeper ground water were taken in every season at 18 locations. To sample shallow ground-water 1,5 m long, screened metal probes were derived into the sediment at the possible nearest point to the surface water. On the field pH, temperature, dissolved oxygen, specific conductivity, and in the wells

  10. 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.

  11. 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

  12. 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. PMID:16637215

  13. 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

  14. 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.

  15. 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

  16. 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

  17. 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

  18. 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). PMID:26117499

  19. 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

  20. 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...

  1. 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…

  2. Evolution of a bank failure along the River Danube at Dunaszekcső, Hungary

    NASA Astrophysics Data System (ADS)

    Újvári, Gábor; Mentes, Gyula; Bányai, László; Kraft, János; Gyimóthy, Attila; Kovács, János

    2009-08-01

    The banks of the River Danube are one of the most susceptible areas to mass wasting in Hungary. In 2007, a large slump began to develop along the Danube at Dunaszekcső and jeopardized properties on land and navigation in the river. Several factors such as geological, hydrogeological and morphological conditions, recurrent flooding and erosion by the Danube led to a gradual development of the large rotational slide. Slope failure has been monitored using GPS, precise levelling techniques and tiltmeters since October 2007. The expected location of the maximum lateral displacement and extrusion was indicated by GPS measurements from the middle of November 2007. The main phase of the slope failure evolution, i.e. the rapid movement on 12 February 2008 was indicated by accelerated tilting of the southern moving block prior to slumping. Small rise of the relatively stable part of the slope was measured after the rapid movements, which may be explained either by the elastic rebound along the slip surface, or by the intrusion of some plastic material into the lower section of the slope. Comparison of geodetic datasets and field observations with the timing of rainfall and water level changes of the Danube suggested that hydrological properties (subsurface flow processes, soil physical properties, infiltration, and perched water table) were primarily responsible for initiation of the studied slump. A model of slope failure evolution is proposed here based on the monitoring and field observations.

  3. 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

  4. 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

  5. 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

  6. 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

  7. "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

  8. 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

  9. 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.

  10. Thermal state of the lithosphere in the Danube Basin and its relation to tectonics

    NASA Astrophysics Data System (ADS)

    Majcin, Dušan; Bilčík, Dušan; Klučiar, Tomáš

    2015-09-01

    The area of the Danube Basin is interesting in the light of the evaluation both of the lithosphere structure and of various theories of Carpathian-Pannonian region tectonic evolution. The aim of this paper is to analyse both the thermal conditions in the Danube Basin and the mutual relations to geological structure and tectonic development of the region under study. First the improved distributions of the terrestrial heat flow density and of the lithosphere thickness were constructed using recently gained geophysical and geological knowledge. Then the critical analysis of existing models of the tectonic development of the region under study was carried out. The tectono-thermal interpretation activities were accomplished by new geothermal modelling approach for transient regime which utilizes also the backstriped sedimentology data as a control parameter of model. Finally the McKenzie's "pure-shear" model of the Danube basin was constructed as acceptable conception for used geothermal and tectonic data. The determined stretching parameter has an inhomogeneous horizontal distribution and the thinning factors express the depth dependency for separate lithospheric layers.

  11. 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.

  12. 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.

  13. 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

  14. "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

  15. "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

  16. 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.

  17. 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.

  18. 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

  19. Flow and sediment processes in a cutoff meander of the Danube Delta during episodic flooding

    NASA Astrophysics Data System (ADS)

    Jugaru Tiron, Laura; Le Coz, Jérôme; Provansal, Mireille; Panin, Nicolae; Raccasi, Guillaume; Dramais, Guillaume; Dussouillez, Philippe

    2009-05-01

    This article analyzes the water and suspended solid fluxes through a straightened meander of the southern branch of the Danube Delta (the St. George branch) during episodic flooding. The Mahmudia study site corresponds to a vast natural meander which was cut off in 1984-1988 by an artificial canal opened to shipping. The meander correction accelerated fluxes through the artificial canal and dramatically enhanced deposition in the former meander. After his formation, the cutoff meander acted as sediment storage locations, essentially removing channel and point bar sediments from the active sediment budget of the main channel. Increases in slope and stream power in reaches upstream and downstream have also occurred, but to a lesser degree. During the one-hundred-year recurrent flood in April 2006, bathymetry, flow velocity and discharge data were acquired across several sections of both natural and artificial channels with an acoustic Doppler current profiler (aDcp Workhorse Sentinel 600 kHz, Teledyne RDI) in order to investigate the distribution of the flow and sediment and his impact on sedimentation in a channelized reach and its adjacent cutoff. The contrasting hydro-sedimentary processes at work in both channels and bifurcation/confluence nodal points are analyzed from the measured flux distribution, morphological profiles and velocity and concentration patterns. In the cutoff, a diminishing of the intensity of the flow velocity (c. 50%) and of the SSC was observed correlated with the aggradation of the river bed. In the bifurcation/confluence nodal points and in the artificial canal were observed the most intensive hydrodynamic activity (high flow velocity, SSC concentration, degradation of the river bad). Both the event-scale and long-term morphological trends of the alluvial system are discussed analyzing the boundary shear stress and SSC variability. Excess boundary shear stress in the sub-reaches directly affected by cutoffs resulted in scour that increased

  20. 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.

  1. 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. PMID:22244685

  2. 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.

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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.

  8. Flow and sediment processes in a cutoff meander of the Danube Delta during 100-year recurrent flood

    NASA Astrophysics Data System (ADS)

    Jugaru Tiron, L.; Le Coz, J.; Provansal, M.; Dutu, F.

    2009-04-01

    River training operations, such as meander cutoff, initiated for navigational purposes often lead to dramatic changes in the streamwise profiles (Hooke, 1986, Kesel, 2003; Kiss et al., 2007). Meander correction affects both the hydraulic and morphodynamical behavior of the modified branches that sedimentation occurs in time, while newly built canals usually experience degradation (Jugaru et. al, 2006). This study reports and analyzes new data on the hydrological and sedimentary processes at work during a morphogenic flood in a large modified meander (the Mahmudia meander) of the St. George branch, the southern branch of the Danube Delta. The 100-year recurrent flood that occurred in 2006 offered an exceptional opportunity for scanning different cross sections of the Mahmudia meander system by means of the emerging Doppler profiler (aDcp) technology in order to analyze the impact on sedimentation and dynamic processes in the study area. The Mahmudia study site corresponds to a vast natural meander which was cut off in 1984-1988 by an artificial canal opened to shipping. The meander correction accelerated fluxes through the artificial canal and dramatically enhanced deposition in the former meander. After his formation, the cutoff meander acted as sediment storage locations, essentially removing channel and point bar sediments from the active sediment budget of the main channel (Popa, 1997). During the one-hundred-year recurrent flood in April 2006, bathymetry, flow velocity and discharge data were acquired across several sections of both natural and artificial channels with an acoustic Doppler current profiler (aDcp Workhorse Sentinel 600 kHz, Teledyne RDI) in order to investigate the distribution of the flow and sediment and his impact on sedimentation in a channelized reach and its adjacent cutoff. The contrasting hydro-sedimentary processes at work in both channels and bifurcation/confluence nodal points are analyzed from the measured flux distribution

  9. 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.

  10. The ecological risk of heavy metals in sediment from the Danube Delta.

    PubMed

    Gati, Gabriel; Pop, Cristian; Brudaşcă, Florin; Gurzău, Anca Elena; Spînu, Marina

    2016-05-01

    The objectives of this study were to assess the sediment contamination with heavy metals and to investigate accordingly the ecological risk posed in the SE of the Danube Delta. Sediments are important in assessing the contamination as they act as reservoirs, transporters and contamination sources. Sediment samples were collected and analysed for lead, cadmium, arsenic and mercury, revealing levels higher than the background, especially for cadmium and mercury (Pb > As > Cd > Hg). Concentrations exceeding the probable effect limit were noticed for arsenic and mercury. The contamination indexes describe the study area as having almost half of the samples as contaminated (pollution load index-PLI 1.04), however the contamination is mostly low-to moderate (modified contamination degree-mCd 1.36). The sediment contamination poses mostly a low ecological risk (RI 94.8). The sediment quality guideline quotient (SQG-Q 0.29) describes a moderate impact, while the probable effect concentration quotient (PEC-Q 0.16) confirms that there are no levels likely to affect the aquatic biota. In our study area, the main Branch of the Danube River and the Secondary Delta are the most affected by contamination, while the narrow, reed abundant channels as the preferred habitat of most aquatic organisms, have a low contamination level. PMID:26944291

  11. 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

  12. On the evolution of precipitation in Central and South-Eastern Europe and its relationship with Lower Danube discharge

    NASA Astrophysics Data System (ADS)

    Dobrica, V.; Demetrescu, C.

    2012-12-01

    The possible changes in temperature and precipitation regime are expected to lead to changes in the water regime of rivers. In this study we investigate the evolution of precipitation in the Upper and Middle Danube Basin, for the 20th century, in connection to variations in the Lower Danube discharge. The analysis is given by using annual means data from 27 meteorological stations and from 4 gauges along the river, on the Romanian territory, namely Orsova, Ceatal, Sulina, and Sf. Gheorghe. The comparison of the average precipitation in the Upper and Middle Danube Basin, as calculated from the records of 17 weather stations, with the discharge at Orsova displays interannual and interdecadal variations in the same way. The variations in precipitation in the Lower Danube Basin, recorded at 10 weather stations, show up to a certain degree in variations of the tributary rivers discharge and in the discharge difference between the upstream station Orsova and the downstream station Ceatal. To discuss interannual to interdecadal variability, the time series have been filtered by means of 11-, 22-, and 78-years running averages and the corresponding variations were compared. It reveals significant variations at the decadal, inter-decadal and centennial timescales.

  13. 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

  14. 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

  15. A multimodel approach to interannual and seasonal prediction of Danube discharge anomalies

    NASA Astrophysics Data System (ADS)

    Rimbu, Norel; Ionita, Monica; Patrut, Simona; Dima, Mihai

    2010-05-01

    Interannual and seasonal predictability of Danube river discharge is investigated using three model types: 1) time series models 2) linear regression models of discharge with large-scale climate mode indices and 3) models based on stable teleconnections. All models are calibrated using discharge and climatic data for the period 1901-1977 and validated for the period 1978-2008 . Various time series models, like autoregressive (AR), moving average (MA), autoregressive and moving average (ARMA) or singular spectrum analysis and autoregressive moving average (SSA+ARMA) models have been calibrated and their skills evaluated. The best results were obtained using SSA+ARMA models. SSA+ARMA models proved to have the highest forecast skill also for other European rivers (Gamiz-Fortis et al. 2008). Multiple linear regression models using large-scale climatic mode indices as predictors have a higher forecast skill than the time series models. The best predictors for Danube discharge are the North Atlantic Oscillation (NAO) and the East Atlantic/Western Russia patterns during winter and spring. Other patterns, like Polar/Eurasian or Tropical Northern Hemisphere (TNH) are good predictors for summer and autumn discharge. Based on stable teleconnection approach (Ionita et al. 2008) we construct prediction models through a combination of sea surface temperature (SST), temperature (T) and precipitation (PP) from the regions where discharge and SST, T and PP variations are stable correlated. Forecast skills of these models are higher than forecast skills of the time series and multiple regression models. The models calibrated and validated in our study can be used for operational prediction of interannual and seasonal Danube discharge anomalies. References Gamiz-Fortis, S., D. Pozo-Vazquez, R.M. Trigo, and Y. Castro-Diez, Quantifying the predictability of winter river flow in Iberia. Part I: intearannual predictability. J. Climate, 2484-2501, 2008. Gamiz-Fortis, S., D. Pozo

  16. Nutrient emissions from diffuse and point sources into the River Danube and its main tributaries for the period of 1998-2000--results and problems.

    PubMed

    Schreiber, H; Behrendt, H; Constantinescu, L T; Cvitanic, I; Drumea, D; Jabucar, D; Juran, S; Pataki, B; Snishko, S; Zessner, M

    2005-01-01

    Nutrient emissions by point and diffuse sources were estimated for 388 sub-catchments of the Danube river basin for the period 1998-2000 by means of the Model MONERIS. For nitrogen total emissions of 684 kt/a N were estimated for the Danube basin. 80% of these emissions were caused by diffuse sources (mainly groundwater, urban areas and tile drainage). For phosphorus the emission was 57 kt/a P, with a contribution of diffuse sources to this sum of 58%. The comparison of calculated and observed loads shows that the mean deviation for the investigated sub-catchments of the Danube river basin is 20% for dissolved inorganic nitrogen and 34% for phosphorus. The spatial resolution of the emission calculations allows the identification of regional hot spots and the derivation of specific regional measures to reduce the emissions into the Danube and consequently into the Western Black Sea. PMID:15850201

  17. 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.

  18. Impact of century flood on the phosphorus stock and mobilization in the Upper Danube

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

    During the past two decades Germany and Austria have undertaken considerable efforts to reduce their phosphorus emissions into the Danube River. In the same period the Upper Danube Basin was also affected by extreme hydrological events, the most notable of which being two large floods in August 2002 and June 2013. This period of combined anthropogenic changes and extreme hydrological conditions represents an exceptional opportunity for exploring interweaving processes and causalities in a large river. In this work time series (1991-2013) of concentrations of total and soluble reactive phosphorus (TP, SRP) and suspended sediments at the inflow and outflow of the Austrian Danube are statistically analyzed per categories of flow level. Moreover, yearly loads are calculated with three different methods and their development in time is examined in the context of emission loads and hydrological regimes. The analysis reveals that a very pronounced and long-lasting decline of the TP concentration took place after the 2002 flood, which was still visible during the 2013 event. The mean TP concentrations before 2002 varied from 0.07 mg/l at low flows to 0.54 mg/l at very high flows. After the 2002 flood the range at all flow levels was reduced to 0.05-0.08 mg/l. The shift affecting high flow conditions could be related neither to reduced emissions nor to reduced turbidity. Therefore the most plausible explanation is that the flood scoured the river bed causing a depletion of the phosphorus rich sediments (primarily algae mass) and that the recovery of this pool was delayed by the low availability of dissolved phosphorus, as a result of reduced point emissions. The development in time of the TP riverine loads offers further evidence of this hypothesis. The presence of a pool of phosphorus rich sediments in the river, derived from the sedimentation of algae mass, maintained during the 1990s a high level of loads and neutralized the efforts of reduction of point discharges

  19. 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.

  20. Spatiotemporal trends of heavy metal concentrations in fish of the River Morava (Danube basin).

    PubMed

    Valová, Zdenka; Jurajda, Pavel; Janác, Michal; Bernardová, Ilja; Hudcová, Hana

    2010-12-01

    The aim of this study was to assess mercury (Hg), cadmium (Cd) and lead (Pb) contamination in muscle tissue of fishes over the longitudinal profile of the River Morava (Czech Republic, Danube basin) and to detect any temporal trends over the past 18 years. Fish samples were collected in 1992, 1998, 2000, 2003 and 2009 at 6 study sites situated just downstream of important pollution sources. Chub (Leuciscus cephalus L.) were selected as indicator species at 5 sites, and brown trout (Salmo trutta m. fario L.) at the uppermost site where chub do not occur. In total, muscle tissue of 175 specimens of chub and 19 specimens of brown trout were analysed. Concentrations of heavy metals ranged as follows: mercury 0.015-0.369 mg/kg; cadmium 0.001-0.254 mg/kg and lead 0.006-1.505 mg/kg. Mercury levels did not exceed the maximum allowed concentration in the Czech Republic (0.5 mg/kg). Content of cadmium and lead in fish muscle exceeded the maximum allowed levels (0.05 and 0.3 mg/kg respectively) in 11 and 4 samples, respectively. On average, the order of metal concentration in fish muscle was: Hg>Pb>Cd. No significant differences were found between sites along the longitudinal profile of the river. Significant differences were found, however, for the interannual comparison of cadmium and lead (but not mercury) at different sites (P < 0.05). A catastrophic flood in 1997 resulted in an increase in metal concentrations, especially cadmium and lead, in the following 1998 season. Our results indicate that the Morava river basin does not represent a threatening source of mercury, cadmium or lead for the River Danube downstream. PMID:20981604

  1. Bivariate analysis of flood peaks and volumes using copulas. An application to the Danube River

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

    A multivariate analysis on flood variables such as flood peaks, volumes and durations, is essential for hydrotechnical projects design. A lot of authors have suggested the use of bivariate distributions for the frequency analysis of flood peaks and volumes due to the supposition that the marginal probability distribution type is the same for these variables. The application of Copulas, which are becoming gradually widespread, can overcome this constraint. The selection of the appropriate copula type/families is not extensively treated in the literature and it remains a challenge in copula analysis. In this study a bivariate copula analysis with the use of different copula families is carried out on the basis of flood peak and the corresponding volumes along a river. This bivariate analysis of flood peaks and volumes is based on streamflow daily data of a time-series more than 100 years from several gauged stations of the Danube River. The methodology applied using annual maximum flood peaks (AMF) with the independent annual maximum volumes of fixed durations at 5, 10, 15,20,25,30 and 60 days. The discharge-volume pairs correlation are examined using Kendall's tau correlation analysis. The copulas families that selected for the bivariate modeling of the extracted pairs discharge and volumes are the Archimedean, Extreme-value and other copula families. The evaluation of the copulas performance achieved with the use of scatterplots of the observed and bootstrapped simulated pairs and formal tests of goodness of fit. Suitability of copulas was statistically compared. Archimedean (e.g. Frank and Clayton) 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 study random variables.

  2. 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

  3. 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. PMID:27199920

  4. 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

  5. Trace element contamination in the arms of the Danube Delta (Romania/Ukraine): current state of knowledge and future needs.

    PubMed

    Vignati, Davide A L; Secrieru, Dan; Bogatova, Yuliya I; Dominik, Janusz; Céréghino, Régis; Berlinsky, Nikolai A; Oaie, Gheorghe; Szobotka, Stefan; Stanica, Adrian

    2013-08-15

    This paper provides the first critical synopsis of contamination by selected trace elements in the whole Danube Delta (Romania/Ukraine) to: identify general patterns of contamination by trace elements across the Delta, provide recommendations to refine existing monitoring networks and discuss the potential toxicity of trace elements in the whole Delta. Sediment samples were collected between 2004 and 2007 in the three main branches of the Delta (Chilia, Sulina and Sfantu Gheorghe) and in the secondary delta of the Chilia branch. Samples were analyzed for trace elements (Cd, Co, Cr, Cu, Ni, Pb, V, and Zn) and TiO₂, Fe₂O₃, MnO, CaCO₃ and total organic carbon. Cluster analysis (CA) and Principal Component Analysis (PCA) showed that levels of Cd, Cu, Pb, and Zn were influenced by anthropogenic activities. At the opposite, concentrations of Cr and Ni largely originated from the weathering of rocks located in the Romanian part of the Danube catchment and naturally rich in these elements. Data analysis using Self-Organizing Maps confirmed the conclusions of CA/PCA and further detected that the contamination tended to be higher in the Chilia and Sulina arms than in the Sfantu Gheorghe arm. The potential ecological risks due to trace element contamination in the Danube Delta could be identified as moderate and localized, provided that the presence of the natural sources of Cr and Ni was properly considered. The available results suggest that monitoring sediment quality at the mouths of Sulina and Sfantu Gheorghe arms is probably enough to get a picture of the sediment quality along their entire lengths. However, a larger network of monitoring points is necessary in the Chilia and secondary Chilia delta to account for the presence of local point sources and for the more complex hydrodynamic of this part of the Danube Delta. PMID:23660537

  6. 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.

  7. 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. PMID:25602548

  8. 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

  9. 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

  10. 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

  11. 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

  12. 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

  13. " 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

  14. Avian Influenza Surveillance in the Danube Delta Using Sentinel Geese and Ducks

    PubMed Central

    Maftei, Daniel Narcis; Chereches, Razvan M.; Bria, Paul; Dragnea, Claudiu; McKenzie, Pamela P.; Valentine, Marissa A.; Gray, Gregory C.

    2014-01-01

    Highly pathogenic avian influenza (HPAI) H5N1 virus incursions from migrating birds have occurred multiple times in Romania since 2005. Beginning in September 2008 through April 2013, seasonal sentinel surveillance for avian influenza A viruses (AIVs) using domestic geese (Anser cygnoides) and ducks (Anas platyrhynchos) in the Danube Delta was established by placing 15 geese and 5 ducks at seven sites. Tracheal and cloacal swabs, and sera collections (starting in 2009) were taken monthly. We studied a total of 580 domestic birds and collected 5,520 cloacal and tracheal swabs from each and 2,760 sera samples. All swabs were studied with real-time reverse transcription polymerase chain reaction (rRT-PCR) for evidence of AIV. Serological samples were studied with hemagglutination inhibition assays against avian H5, H7, and H9 influenza viruses. From 2009 to 2013, 47 swab specimens from Cot Candura, Enisala, and Saon screened positive for AIV; further subtyping demonstrated that 14 ducks and 20 geese had cloacal evidence of H5N3 carriage. Correspondingly, 4 to 12 weeks after these molecular detections, sentinel bird sera revealed elevated HI titers against H5 virus antigens. We posit that domestic bird surveillance is an effective method to conduct AIV surveillance among migrating birds in delta areas. PMID:24795823

  15. 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.

  16. Analysis and modelling of spatio-temporal properties of daily rainfall over the Danube basin

    NASA Astrophysics Data System (ADS)

    Serinaldi, F.; Kilsby, C. G.

    2012-04-01

    Central and Eastern Europe are prone to severe floods due to heavy rainfall that cause societal and economic damages, ranging from agriculture to water resources, from the insurance/reinsurance sector to the energy industry. To improve the flood risk analysis, a better characterisation and modelling of the rainfall patterns over this area, which involves the Danube river watershed, is strategically important. In this study, we analyse the spatio-temporal properties of a large data set of daily rainfall time series from 15 countries in the Central Eastern Europe through different lagged and non-lagged indices of associations that quantify both the overall dependence and extreme dependence of pairwise observations. We also show that these measures are linked to each other and can be written in a unique and coherent notation within the copula framework. Moreover, the lagged version of these measures allows exploring some important spatio-temporal properties of the rainfall fields. The exploratory analysis is complemented by the preliminary results of a spatio-temporal rainfall simulation performed via a compound model based upon the Generalized Additive Models for Location, Scale and Shape (GAMLSS) and meta-elliptical multivariate distributions.

  17. 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

  18. 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

  19. 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

  20. R.E.E.L.D. (Economical and Ecological Reconstruction of the Danube Flood Plain) Campaign: airborne LIDAR data and GIS technique outputs

    NASA Astrophysics Data System (ADS)

    Covǎsnianu, Adrian; Tudose, Ovidiu-Gelu; Cazacu, Marius-Mihai; Nichersu, Iulian; Memier, Michel; Balin, Ioan

    2010-05-01

    The study is the synthesis of the REELD (Economical and Ecological Reconstruction of the Danube Flood Plain) 2007 campaign and its applications, but also resenting the final results of the project. This unique work, by resolution and surface covering, performed in 2007 over the whole Romanian Danube plain resulted in a high resolute digital terrain and digital surface models covering over 700.000 ha. Using this extremely accurate terrain model, derivate applications were performed such as analyze of the actual geomorphologic processes (gullies, landslides, etc.), land cover dynamics, urban development indicators and also hydrological modeling for forecast and risk prevention.

  1. 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

  2. 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

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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. PMID:26412421

  8. The morphological response of the Danube River to the August 2002 flood

    NASA Astrophysics Data System (ADS)

    Fischer-Antze, T.; Gutknecht, D.; Bors, W.; Kölbl, C.

    2003-04-01

    This paper addresses the impact of the August 2002 flood on the morphological changes of the Danube River between Vienna and the Austrian-Slovakian border. This 40 km long reach is one of the two remaining freely flowing reaches in Austria. At the upstream end, the hydropower station Freudenau in Vienna acts as a barrier to the sediment transport which disturbs the natural sediment dynamics. To compensate the sediment deficit the operator of the power station is required to add yearly amounts of gravel material. The reach is significantly influenced by river engineering works, in particular by groynes and fixed banks. In regions of minor influence the development of alternate bars can be observed. To assess the changes of the river bed, regular semi-annual measurements of the river bed have been performed in cross-sections at longitudinal spacing of 100 meters. A combined differential GPS and single beam echo sounder measuring technology has been applied to obtain the absolute river bed position and elevation. On average 500 measurements per cross-section have been collected. The effect on the river bed morphology of the August 2002 flood is assessed by comparing the river bed surveys in spring and autumn 2002. The magnitude of this event was on the order of 100 years. We determine river bed changes in turns of river bed elevation, volume differences and a number of morphological parameters including cross-sectional shape and asymmetry parameters for both surveys. The results indicate that the overall morphological features - sizes, shapes and locations of the gravel bars, thalweg positions - have not changed. Volume differences indicate no significant overall change and local changes occur of up to 1 meter. Further interpretations of these results will be provided in the context of the long-term evolution of the river bed.

  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. 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

  11. 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

  12. 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. PMID:27094057

  13. 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

  14. Origin of shallow groundwater of Csepel Island (south of Budapest, Hungary, River Danube): isotopic and chemical approach

    NASA Astrophysics Data System (ADS)

    Fórizs, I.; Berecz, T.; Molnár, Z.; Süveges, M.

    2005-11-01

    The shallowest aquifer of the alluvial Csepel Island is used for drinking water supply for Budapest and the surrounding villages. A previous two-dimensional hydraulic model failed to explain many observations; therefore, a three-dimensional hydraulic model was constructed using the software application MODFLOW. Isotopic and hydrogeochemical investigations were carried out during the period 1998 to 2002 in order to provide model data. Four water sources have been identified, having different isotopic (and chemical) characteristics. Danube water is characterized by seasonally varying 18O values: its unweighted mean 18O value is -10.9 for the years 1998 to 2002. The most negative 18O values occur in late spring and summertime. Average tritium content is 20 TU. Infiltrated precipitation has 18O values between -9.0 and -9.5. The average tritium content of the precipitation is 10 TU, and that of infiltrated precipitation must be close to this value and about half that of the Danube. The 18O value of lake water is > -9.0. Its stable isotope composition plots on the right side of the local meteoric water line on the D-18O diagram. Ascending deep groundwater (sampled depth of 20-140 m) has 18O values between -12.0 and -13.5. Its radiocarbon age is between 16 000 and 30 000 years BP, probably infiltrated during and around the last glacial maximum (Würm III) period of the latest glaciation. Copyright

  15. 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

  16. 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

  17. 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

  18. Hydrological cycle in the Danube basin in present and projected future climate conditions: a models' intercomparison perspective

    NASA Astrophysics Data System (ADS)

    Lucarini, V.

    2010-09-01

    We present an intercomparison and verification analysis of several GCMs and RCMs included in the 4th IPCC assessment report on their representation of the hydrological cycle on the Danube river basin for present and (in the case of the GCMs) projected future climate conditions. The basin-scale properties of the hydrological cycle are computed by spatially integrating the precipitation, evaporation, and runoff fields using the Voronoi-Thiessen tessellation formalism. Large discrepancies exist among RCMs for the monthly climatology as well as for the mean and variability of the annual balances, and only few data sets are consistent with the observed discharge values of the Danube at its Delta. This occurs in spite of common nesting of the RCMs into the same run of the same AGCM, and even if the driving AGCM provides itself an excellent estimate. We find consistently that, for a given model, increases in the resolution do not alter the net water balance, while speeding up the hydrological cycle through the enhancement of both precipitation and evaporation by the same amount. We propose that the atmospheric components of RCMs still face difficulties in representing the water balance even on a relatively large scale. Moreover, since for some models the hydrological balance estimates obtained with the runoff fields do not agree with those obtained via precipitation and evaporation, some deficiencies of the land models are also apparent. In the case of the GCMs, the span of the model- simulated mean annual water balances is of the same order of magnitude of the observed Danube discharge of the Delta; the true value is within the range simulated by the models. Some land components seem to have deficiencies since there are cases of violation of water conservation when annual means are considered. The overall performance and the degree of agreement of the GCMs are, surprisingly, comparable to those of the RCMs. Both RCMs and GCMs greatly outperform the NCEP-NCAR and ERA-40

  19. Large-Scale Water Resources Management within the Framework of GLOWA-Danube - Part A: The Groundwater Model

    NASA Astrophysics Data System (ADS)

    Barthel, R.; Rojanschi, V.; Wolf, J.; Braun, J.

    2003-04-01

    The interdisciplinary research co-operation Glowa-Danube aims at the development of innovative techniques, scenarios and strategies to investigate the impacts of Global Change on the hydrological cycle within the catchment area of the Upper Danube Basin (Gauge Passau). Both the influence of natural changes in the ecosystem, such as climate change, and changes in human behavior, such as changes in land use or water consumption, are considered. A globally applicable decision support tool "DANUBIA" that comprises 15 individual disciplinary models will be developed. The models are connected with each other 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. The Institute of Hydraulic Engineering of the Universitaet Stuttgart contributes two models to DANUBIA: A groundwater flow and transport model and a water supply model. The latter is dealt with in a second contribution to this conference. This paper focuses on the groundwater model. The catchment basin of the Upper Danube covers an area of approximately 77.000 km2. The elevation difference from the highest peaks of the Alps to the lowest flatlands in the Danube valley is more than 3.000 m. In addition to the Alps, several lower mountain ranges such as the Black Forest, the Swabian and Franconian Alb and the Bavarian Forest are located respectively in the Northeast, North and Northwest of the basin. The climatic conditions, geomorphology, geology and land use show a wide range of different characteristics. The size and heterogeneity of the area make it extremely difficult to represent the natural conditions in a numerical model. Both data availability and accessibility add to the difficulties that one encounters in the approach to simulate groundwater flow and contaminant transport in this area. The groundwater flow model of

  20. Statistical analysis of the influence of major tributaries to the eco-chemical status of the Danube River.

    PubMed

    Ilijević, Konstantin; Obradović, Marko; Jevremović, Vesna; Gržetić, Ivan

    2015-09-01

    We have assembled and assessed the statistical procedure which is capable to objectively explore influence of the Danube's major tributaries (the Rivers Tisa, Sava, and Velika Morava) to its eco-chemical status. Procedure contains several tests for measurement of central tendencies: one-way analysis of variance (ANOVA), repeated measures ANOVA, and nonparametric Kruskal-Wallis and Mann-Whitney tests. Various nuisance factors, (outliers, departures from normality, seasonality, and heteroscedasticity) which are present in large data bases, affect the objectivity of central tendency tests; therefore, it was important not only to estimate their robustness, but also to apply proper procedures for detection of the nuisance factors (Grubbs', generalized ESD-extreme Studentized deviate, Kolmogorov-Smirnov, Shapiro-Wilk, turning point, Wald-Wolfowitz runs, Kendall rank, and Levene's tests) and to mitigate their influence (outlier exclusion, Box-Cox, and logarithmic transformations). The analysis of selected eco-chemical parameters: biological oxygen demand-5, chemical oxygen demand, UV extinction at 254 nm, dissolved oxygen, oxygen saturation, total dissolved solids, electrical conductivity, suspended matter, total phosphorus, phosphates, nitrates, ammonia, pH, total alkalinity, m-2p alkalinity, CO2, and temperature, was performed for 15 years period. The Tisa was the most polluted tributary, but its pollution load was not substantial enough to exceed the Danube self-purification potential. The City of Belgrade was also identified as serious pollution source. Assessment of assembled statistical procedure, which was based on the real environmental data, indicates that proposed tests are sufficiently robust to the observed level of nuisance factors with the exception of pronounced seasonality. PMID:26239571

  1. 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

  2. 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

  3. Detection and evaluation of changes induced by the diversion of River Danube in the territorial appearance of latent effects governing shallow-groundwater fluctuations

    NASA Astrophysics Data System (ADS)

    Kovács, József; Márkus, László; Szalai, József; Kovács, Ilona Székely

    2015-01-01

    The paper assesses the impact on the fluctuation of the shallow-groundwater table of the diversion of the Danube upstream from the Gabčikovo/Bős hydroelectric power plant in a hydraulically connected, geologically identical, and structurally not decomposable geological area in North-West Hungary. On the basis of shallow-groundwater level monitoring data the impact was traced back to the effect of the Danube's changed flow course, and quantized for the whole study area. To this end the influence of the river had to be separated from the effect of precipitation. The means chosen was the application of dynamic factor analysis to the registered hydrograph time series. We conclude that the originally homogeneous and dominant effect of the Danube has split and now consists of a diverted and a returning component (downstream from the power plant), and that this is a likely cause of ram-effect and river bed clogging. Furthermore the effect of precipitation ceased to be suppressed, and came to the fore.

  4. Estimates of the sequence of precipitation states in the Danube Basin for the 21st century, by a statistical downscaling procedure based on NHMM

    NASA Astrophysics Data System (ADS)

    Mares, Constantin; Mares, Ileana; Mihailescu, Mihaela

    2014-05-01

    In the Danube lower basin, the highest discharges are recorded in spring months. Precipitation in the Danube upper and middle Basin are the main indicators for the Danube discharge at the entry in the lower basin. The best links of the spring discharges in the lower basin are with the winter precipitation from 15 stations situated especially in the middle Danube basin. In the first stage, we focused on finding some robust predictors from the sea level pressure (SLP) for precipitation in winter, and then by a statistical downscaling procedure we have obtained precipitation estimation for 21 st century. We have identified a new atmospheric index called Greenland-Balkan-Oscillation-Index (GBOI) that has a great impact on precipitation in the Danube basin (mainly middle and lower) in winter. Simultaneous correlations (0.75-0.84), stable for two series of 42-yr, with high level of significance were found between GBOI and the first temporal component of the decomposition in the Empirical Orthogonal Functions of precipitation (PC1-PP). This link is much closer than with other large-scale phenomena such as the North Atlantic Oscillation. Using the simulations by the HADGEM1 model (scenario A1B, stream 1), a stochastic modeling was performed between GBOI and PC1-PP by means of a nonhomogeneous hidden Markov model (NHMM) with three states. Using probabilistic relation between PC1-PP and GBOI in the 20th century, and modifying GBOI simulated by HADGEM1 for two periods in the 21st century, we obtained an estimate of precipitation in the 21st century. For the normal state of precipitation, in both periods in the 21st century, the occurrence probability of this state is lower than that for the 20th century. For the state indicating a deficit of precipitation, the occurrence probability of this state in the 21st century (especially in the first period) is much higher than in the 20th century. The state representing precipitation in excess occurs with lower probabilities in the 21

  5. Channel incision at the Danube River east of Vienna: verifying bed-load transport rates by different methods

    NASA Astrophysics Data System (ADS)

    Tritthart, M.; Liedermann, M.; Habersack, H.

    2012-04-01

    The gravel-bed section of the Danube River east of Vienna, located along 48 km between Vienna and Bratislava, is one of only two free-flowing reaches at the Danube in Austria. Long-term analyses of gauge water levels have indicated a trend towards incision of the river bed, which has been lasting for several decades and is still ongoing. Lack of sediment continuity due to retention by upstream power plants and a sediment deficit caused by bank protection measures causing channelization and preventing lateral erosion were identified as the main causes for erosion. This study aims at determining the current erosion rate from the annual bed-load transport during the years 2005 through 2009 by applying two different methods: (i) calculation of volume differences from Digital Elevation Models (DEMs); (ii) upscaling of bed-load basket sampler measurements. Each of the two methods was analyzed in terms of accuracy and associated methodical errors. Four different interpolation methods to calculate DEMs from single-beam bathymetric measurements were statistically compared to a DEM originating from a multi-beam survey. It was found that streamline-based interpolation algorithms were associated with the highest accuracy. Using this technique, DEMs for each of the monitoring years were compiled and differential models could be derived, showing an annual sediment deficit due to erosion of approximately 360,000 m3. By applying Richardson extrapolation it was found that the potential error of this estimate due to a single-beam cross-section distance of 50 m was only 1.1 %. Numerous bed-load transport measurements were conducted in the monitoring period by lowering a heavy-load basket sampler along a cross section from a road bridge to the river bed. This allowed for sampling to be conducted during the entire discharge spectrum, covering low flows as well as a 15-year flood. Based on these data, a bed-load rating curve following a sigma function was compiled. By linking this

  6. Analysis of isotopic signals in the Danube River water at Tulln, Austria, based on daily grab samples in 2012.

    PubMed

    Wyhlidal, Stefan; Rank, Dieter; Schott, Katharina; Heiss, Gerhard; Goetz, Jason

    2014-01-01

    Results of stable isotope measurements (δ(2)H, δ(18)O) of daily grab samples, taken from the Danube River at Tulln (river km 1963) during 2012, show seasonal and short-term variations depending on the climatic/hydrological conditions and changes in the catchment area (temperature changes, heavy rains and snow melt processes). Isotope ratios in river water clearly reflect the isotopic composition of precipitation water in the catchment area since evaporation influences play a minor role. Average δ(2)H and δ(18)O values in 2012 are-78‰ and-11.0‰, respectively, deuterium excess averages 10‰. The entire variation amounts to 1.8‰ in δ(18)O and 15‰ in δ(2)H. Quick changes of the isotopic composition within a few days emphasise the necessity of daily sampling for the investigation of hydrological events, while monthly grab sampling seems sufficient for the investigation of long-term hydro-climatic trends. (3)H results show peaks (half-width 1-2 days, up to about 150 TU) exceeding the regional environmental level of about 9 TU, probably due to releases from nuclear power plants. PMID:24678624

  7. Heavy metal and trace element bioaccumulation in target tissues of four edible fish species from the Danube River (Serbia).

    PubMed

    Subotić, Srđan; Spasić, Slađana; Višnjić-Jeftić, Zeljka; Hegediš, Aleksandar; Krpo-Ćetković, Jasmina; Mićković, Branislav; Skorić, Stefan; Lenhardt, Mirjana

    2013-12-01

    Pikeperch (Sander lucioperca), European catfish (Silurus glanis), burbot (Lota lota), and common carp (Cyprinus carpio) were collected from the Danube River (Belgrade section, Serbia), and samples of liver, muscle, and gills were analyzed for Al, As, B, Ba, Cd, Co, Cr, Cu, Fe, Hg, Li, Mn, Mo, Ni, Pb, Se, Sr, and Zn using inductively coupled plasma optical emission spectrometry (ICP-OES) to highlight the importance of species and tissue selection in monitoring research, contaminant studies, and human health research. The Kruskal-Wallis test revealed significant differences between fish species in regard to metal levels in liver, muscle, and gills. The principal component analysis (PCA) indicated that the studied fish species could be grouped on the basis of the level of analyzed elements in liver and gills. The Mann-Whitney test showed two subsets (one comprising two piscivorous species, pikeperch and catfish, and the other, two polyphagous species, burbot and carp) in regard to Cr and Hg levels in liver (higher levels in piscivorous species), as well as B, Fe, and Hg in gills (B and Fe with higher levels in polyphagous and Hg in piscivorous species), and As in muscle (higher levels in polyphagous species). Carp had distinctly higher levels of Cd, Cu, and Zn in liver in comparison to other three species. None of the elements exceeded the maximum acceptable concentrations (MAC). However, since Hg levels are close to the prescribed MAC levels, the consumption of these fishes can be potentially hazardous for humans. PMID:24054751

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Degradation and restoration of soils in the Moscow River floodplain for the last fifty years

    NASA Astrophysics Data System (ADS)

    Zaidelman, F. R.; Belichenko, M. V.; Bibin, A. S.

    2013-11-01

    During a short-term recent period (about 50 years), many floodplains of the Nonchernozemic zone were used as meadows, croplands for growing row crops, or they were abandoned. This was done to supply the populations of industrial cities with vegetables. In this case, the agrotechnical, ameliorative, and some other measures applied were often incompatible with the properties of the floodplain soils and caused their degradation. Among these measures was the elimination of grasses in the crop rotation, the monoculture of row crops, inadequate irrigation inducing systematic waterlogging, and the wide use of heavy agricultural machines. The consequences of using such technologies were investigated by the authors; on these soils, row crop were grown for 30 years and, for the next 20 years, the soils were left under fallow. Based on the data obtained, methods for the floodplain soils' protection against degradation are proposed.

  15. Assessing and optimising flood control options along the Arachthos river floodplain (Epirus, Greece)

    NASA Astrophysics Data System (ADS)

    Drosou, Athina; Dimitriadis, Panayiotis; Lykou, Archontia; Kossieris, Panagiotis; Tsoukalas, Ioannis; Efstratiadis, Andreas; Mamassis, Nikos

    2015-04-01

    We present a multi-criteria simulation-optimization framework for the optimal design and setting of flood protection structures along river banks. The methodology is tested in the lower course of the Arachthos River (Epirus, Greece), downstream of the hydroelectric dam of Pournari. The entire study area is very sensitive, particularly because the river crosses the urban area of Arta, which is located just after the dam. Moreover, extended agricultural areas that are crucial for the local economy are prone to floods. In the proposed methodology we investigate two conflicting criteria, i.e. the minimization of flood hazards (due to damages to urban infrastructures, crops, etc.) and the minimization of construction costs of the essential hydraulic structures (e.g. dikes). For the hydraulic simulation we examine two flood routing models, named 1D HEC-RAS and quasi-2D LISFLOOD, whereas the optimization is carried out through the Surrogate-Enhanced Evolutionary Annealing-Simplex (SE-EAS) algorithm that couples the strengths of surrogate modeling with the effectiveness and efficiency of the EAS method.

  16. 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.

  17. 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

  18. 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

  19. 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.

  20. Mobilization of arsenic and iron from Red River floodplain sediments, Vietnam

    NASA Astrophysics Data System (ADS)

    Postma, Dieke; Jessen, Søren; Hue, Nguyen Thi Minh; Duc, Mai Thanh; Koch, Christian Bender; Viet, Pham Hung; Nhan, Pham Quy; Larsen, Flemming

    2010-06-01

    Sediments from the Red River and from an adjacent floodplain aquifer were investigated with respect to the speciation of Fe and As in the solid phase, to trace the diagenetic changes in the river sediment upon burial into young aquifers, and the related mechanisms of arsenic release to the groundwater. Goethite with subordinate amounts of hematite were, using Mössbauer spectroscopy, identified as the iron oxide minerals present in both types of sediment. The release kinetics of Fe, As, Mn and PO 4 from the sediment were investigated in leaching experiments with HCl and 10 mM ascorbic acid, both at pH 3. From the river sediments, most of the Fe and As was mobilized by reductive dissolution with ascorbic acid while HCl released very little Fe and As. This suggests As to be associated with an Fe-oxide phase. For oxidized aquifer sediment most Fe was mobilized by ascorbic acid but here not much As was released. However, the reduced aquifer sediments contained a large pool of Fe(II) and As that is readily leached by HCl, probably derived from an unidentified authigenic Fe(II)-containing mineral which incorporates As as well. Extraction with ascorbic acid indicates that the river sediments contain both As(V) and As(III), while the reduced aquifer sediment almost exclusively releases As(III). The difference in the amount of Fe(II) leached from river and oxidized aquifer sediments by ascorbic acid and HCl, was attributed to reductive dissolution of Fe(III). The reactivity of this pool of Fe(III) was quantified by a rate law and compared to that of synthetic iron oxides. In the river mud, Fe(III) had a reactivity close to that of ferrihydrite, while the river sand and oxidized aquifer sediment exhibited a reactivity ranging from lepidocrocite or poorly crystalline goethite to hematite. Mineralogy by itself appears to be a poor predictor of the iron oxide reactivity in natural samples using the reactivity of synthetic Fe-oxides as a reference. Sediments were incubated, both unamended and with acetate added, and monitored for up to 2 months. The river mud showed the fastest release of both Fe and As, while the effect of acetate addition was minor. This suggests that the presence of reactive organic carbon is not rate limiting. In the case of the river and aquifer sediments, the release of Fe and As was always stimulated by acetate addition and here reactive organic carbon was clearly the rate limiting factor. The reduced aquifer sediment apparently can sustain slower but prolonged microbially-driven release of As. The highly reactive pools of Fe(III) and As in the river mud could be due to reoxidation of As and Fe contained in the reducing groundwater from the floodplain aquifers that are discharging into the river. Deposition of the suspended mud on the floodplain during high river stages is proposed to be a major flux of As onto the floodplain and into the underlying aquifers.

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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

  6. Methane flux from the Amazon River floodplain: Emissions during rising water

    SciTech Connect

    Bartlett, K.B.; Crill, P.M. ); Bonassi, J.A. ); Richey, J.E. ); Harriss, R.C. NASA Langley Research Center, Hampton, VA )

    1990-09-20

    During April and May of 1987, an extensive methane flux data set from Amazonian wetland habitats was collected during the wet season as river water levels were high and rising. This work extends measurements made in the dry season of 1985, when water levels were falling. A total of 284 flux measurements were made in the three primary floodplain environments of open-water lakes and channels, floating grass mats, and flooded forests, along approximately 1,500 km of the central floodplain. Emissions (means and standard errors) were 74 {plus minus} 14 mg CH{sub 4}/m{sup 2}/d (open water), 201 {plus minus} 35 mg CH{sub 4}/m{sup 2}/d (grass mats), and 126 {plus minus} 20 mg CH{sub 4}/m{sup 2}/d (flooded forests). These values were not significantly different from the majority of those from 1985, in part due to the high variability in flux seen at both times. Although ebullition was a significant component of methane emissions at both periods, the frequency of bubbling and its contribution to total flux was lower during the period of rising water than during falling water. A prominent diurnal pattern in atmospheric methane concentrations was observed, with minimum levels of about 1.75 ppm at midday and a maximum of 2.12 ppm at about midnight. Given the relatively small season changes observed in flux at the two stages of the rivers hydrographic curve, earlier estimates of regional methane flux remain largely unchanged. Revision of global estimates of wetland methane sources based on these tropical data and recently published figures for northern peatlands indicated that tropical wetlands may be more important than previously suggested, but that wetland sources overall remain at approximately 110 Tg/yr.

  7. 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.

  8. 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.

  9. 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

  10. 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...