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Sample records for certej river catchment

  1. Environmental and socioeconomic assessment of impacts by mining activities-a case study in the Certej River catchment, Western Carpathians, Romania.

    Science.gov (United States)

    Zobrist, Jürg; Sima, Mihaela; Dogaru, Diana; Senila, Marin; Yang, Hong; Popescu, Claudia; Roman, Cecilia; Bela, Abraham; Frei, Linda; Dold, Bernhard; Balteanu, Dan

    2009-08-01

    In the region of the Apuseni Mountains, part of the Western Carpathians in Romania, metal mining activities have a long-standing tradition. These mining industries created a clearly beneficial economic development in the region. But their activities also caused impairments to the environment, such as acid mine drainage (AMD) resulting in long-lasting heavy metal pollution of waters and sediments. The study, established in the context of the ESTROM programme, investigated the impact of metal mining activities both from environmental and socioeconomic perspectives and tried to incorporate the results of the two approaches into an integrated proposition for mitigation of mining-related issues. The small Certej catchment, situated in the Southern Apuseni Mountains, covers an area of 78 km(2). About 4,500 inhabitants are living in the basin, in which metal mining was the main economic sector. An open pit and several abandoned underground mines are producing heavy metal-loaded acidic water that is discharged untreated into the main river. The solid wastes of mineral processing plants were deposited in several dumps and tailings impoundment embodying the acidic water-producing mineral pyrite. The natural science team collected samples from surface waters, drinking water from dug wells and from groundwater. Filtered and total heavy metals, both after enrichment, and major cations were analysed by inductively coupled plasma optical emission spectroscopy (ICP-OES). Major anions in waters, measured by ion chromatography, alkalinity and acidity were determined by titration. Solid samples were taken from river sediments and from the largest tailings dam. The latter were characterised by X-ray fluorescence and X-ray diffraction. Heavy metals in sediments were analysed after digestion. Simultaneously, the socioeconomic team performed a household survey to evaluate the perception of people related to the river and drinking water pollution by way of a logistic regression analysis

  2. Community Perception of Water Quality in a Mining-Affected Area: A Case Study for the Certej Catchment in the Apuseni Mountains in Romania

    Science.gov (United States)

    Dogaru, Diana; Zobrist, Jürg; Balteanu, Dan; Popescu, Claudia; Sima, Mihaela; Amini, Manouchehr; Yang, Hong

    2009-06-01

    Mining-contaminated sites and the affected communities at risk are important issues on the agenda of both researchers and policy makers, particularly in the former communist block countries in Eastern Europe. Integrated analyses and expert based assessments concerning mining affected areas are important in providing solid policy guidelines for environmental and social risk management and mitigation. Based on a survey for 103 households conducted in a former mining site in the Certej Catchment of the Apuseni Mountains, western Romania, this study assesses local communities’ perceptions on the quality of water in their living area. Logistic regression was used to examine peoples’ perception on the quality of the main river water and of the drinking water based on several predictors relating to social and economic conditions. The results from the perception analysis were then compared with the measurements of heavy metal contamination of the main river and drinking water undertaken in the same study area. The findings indicate that perception and measurement results for the water quality in the Certej Catchment are convergent, suggesting an obvious risk that mining activities pose on the surface water. However, the perception on drinking water quality was little predicted by the regression model and does not seem to be so much related to mining as to other explanatory factors, such as special mineralogy of rock and soils or improper water treatment infrastructure, facts suggested by the measurements of the contaminants. Discussion about the implications of these joint findings for risk mitigation policies completes this article.

  3. Hydrological Catchment Similarity Assessment in Geum River Catchments, Korea

    Science.gov (United States)

    Ko, Ara; Park, Kisoon; Lee, Hyosang

    2013-04-01

    Similarity measure of catchments is essential for regionalization studies, which provide in depth analysis in hydrological response and flood estimations at ungauged catchments. However, this similarity measure is often biased to the selected catchments and is notclearly explained in hydrological sense. This study applied a type of hydrological similarity distance measure-Flood Estimation Handbook to 25 Geum river catchments, Korea. Three Catchment Characteristics, Area (A)-Annual precipitation (SAAR)-SCS Curve Number (CN), are used in Euclidian distance measures. Furthermore, six index of Flow Duration Curve (ILow:Q275/Q185, IDrought:Q355/Q185, IFlood:Qmax/Q185, IAbundant:Q95/Q185, IFloodDuration:Q10/Q355 and IRiverRegime:Qmax/Qmin) are applied to clustering analysis of SPSS. The catchments' grouping of hydrological similarity measures suggests three groups: H1 (Cheongseong, Gidae, Bukil, Oksan, Seockhwa, Habgang and Sangyeogyo), H2 (Cheongju, Guryong, Ugon, Boksu, Useong and Seokdong) and H3 (Muju, Yangganggyo and YongdamDam). The four catchments (Cheoncheon, Donghyang, DaecheongDam and Indong) are not grouped in this study. The clustering analysis of FDC provides four Groups; CFDC1 (Muju, YongdamDam, Yangganggyo, DaecheongDam, Cheongseong, Gidae, Seokhwa, Bukil, Habgang, Cheongju, Oksan, Yuseong and Guryong), CFDC2 (Cheoncheon, Donghyang, Boksu, Indong, Nonsan, Seokdong, Ugon, Simcheon, Useong and Sangyeogyo), CFDC3 (Songcheon) and CFDC4 (Tanbu). The six catchments (out of seven) of H1 are grouped in CFDC1, while Sangyeogyo is grouped in CFDC2. The four catchments (out of six) of H2 are also grouped in CFDC2, while Cheongju and Guryong are grouped in CFDC1. The catchments of H3 are categorized in CFDC1. The authors examine the results (H1, H2 and H3) of similarity measure based on catchment physical descriptors with results (CFDC1 and CFDC2) of clustering based on catchment hydrological response. The results of hydrological similarity measures are supported by

  4. Creating a catchment perspective for river restoration

    Science.gov (United States)

    Benda, L.; Miller, D.; Barquín, J.

    2011-03-01

    One of the major challenges in river restoration is to identify the natural fluvial landscape in catchments with a long history of river control. Intensive land use on valley floors often predates the earliest remote sensing: levees, dikes, dams, and other structures alter valley-floor morphology, river channels and flow regimes. Consequently, morphological patterns indicative of the fluvial landscape including multiple channels, extensive floodplains, wetlands, and fluvial-riparian and tributary-confluence dynamics can be obscured, and information to develop appropriate and cost effective river restoration strategies can be unavailable. This is the case in the Pas River catchment in northern Spain (650 km2), in which land use and development have obscured the natural fluvial landscape in many parts of the basin. To address this issue we coupled general principles of hydro-geomorphic processes with computer tools to characterize the fluvial landscape. Using a 5-m digital elevation model, valley-floor surfaces were mapped according to elevation above the channel and proximity to key geomorphic processes. The predicted fluvial landscape is patchily distributed according to topography, valley morphology, river network structure, and fan and terrace landforms. The vast majority of the fluvial landscape in the main segments of the Pas River catchment is presently masked by human infrastructure, with only 15% not impacted by river control structures and development. The reconstructed fluvial landscape provides a catchment scale context to support restoration planning, in which areas of potential ecological productivity and diversity could be targeted for in-channel, floodplain and riparian restoration projects.

  5. Creating a catchment perspective for river restoration

    Directory of Open Access Journals (Sweden)

    L. Benda

    2011-03-01

    Full Text Available One of the major challenges in river restoration is to identify the natural fluvial landscape in catchments with a long history of river control. Intensive land use on valley floors often predates the earliest remote sensing: levees, dikes, dams, and other structures alter valley-floor morphology, river channels and flow regimes. Consequently, morphological patterns indicative of the fluvial landscape including multiple channels, extensive floodplains, wetlands, and fluvial-riparian and tributary-confluence dynamics can be obscured, and information to develop appropriate and cost effective river restoration strategies can be unavailable. This is the case in the Pas River catchment in northern Spain (650 km2, in which land use and development have obscured the natural fluvial landscape in many parts of the basin. To address this issue we coupled general principles of hydro-geomorphic processes with computer tools to characterize the fluvial landscape. Using a 5-m digital elevation model, valley-floor surfaces were mapped according to elevation above the channel and proximity to key geomorphic processes. The predicted fluvial landscape is patchily distributed according to topography, valley morphology, river network structure, and fan and terrace landforms. The vast majority of the fluvial landscape in the main segments of the Pas River catchment is presently masked by human infrastructure, with only 15% not impacted by river control structures and development. The reconstructed fluvial landscape provides a catchment scale context to support restoration planning, in which areas of potential ecological productivity and diversity could be targeted for in-channel, floodplain and riparian restoration projects.

  6. Can spatial statistical river temperature models be transferred between catchments?

    Science.gov (United States)

    Jackson, Faye L.; Fryer, Robert J.; Hannah, David M.; Malcolm, Iain A.

    2017-09-01

    There has been increasing use of spatial statistical models to understand and predict river temperature (Tw) from landscape covariates. However, it is not financially or logistically feasible to monitor all rivers and the transferability of such models has not been explored. This paper uses Tw data from four river catchments collected in August 2015 to assess how well spatial regression models predict the maximum 7-day rolling mean of daily maximum Tw (Twmax) within and between catchments. Models were fitted for each catchment separately using (1) landscape covariates only (LS models) and (2) landscape covariates and an air temperature (Ta) metric (LS_Ta models). All the LS models included upstream catchment area and three included a river network smoother (RNS) that accounted for unexplained spatial structure. The LS models transferred reasonably to other catchments, at least when predicting relative levels of Twmax. However, the predictions were biased when mean Twmax differed between catchments. The RNS was needed to characterise and predict finer-scale spatially correlated variation. Because the RNS was unique to each catchment and thus non-transferable, predictions were better within catchments than between catchments. A single model fitted to all catchments found no interactions between the landscape covariates and catchment, suggesting that the landscape relationships were transferable. The LS_Ta models transferred less well, with particularly poor performance when the relationship with the Ta metric was physically implausible or required extrapolation outside the range of the data. A single model fitted to all catchments found catchment-specific relationships between Twmax and the Ta metric, indicating that the Ta metric was not transferable. These findings improve our understanding of the transferability of spatial statistical river temperature models and provide a foundation for developing new approaches for predicting Tw at unmonitored locations across

  7. Modelling a river catchment using an electrical circuit analogue

    Directory of Open Access Journals (Sweden)

    C. G. Collier

    1998-01-01

    Full Text Available An electrical circuit analogue of a river catchment is described from which is derived an hydrological model of river flow called the River Electrical Water Analogue Research and Development (REWARD model. The model is based upon an analytic solution to the equation governing the flow of electricity in an inductance-capacitance-resistance (LCR circuit. An interpretation of L, C and R in terms of catchment parameters and physical processes is proposed, and tested for the River Irwell catchment in northwest England. Hydrograph characteristics evaluated using the model are compared with observed hydrographs, confirming that the modelling approach does provide a reliable framework within which to investigate the impact of variations in model input data.

  8. Creating a catchment scale perspective for river restoration

    Science.gov (United States)

    Benda, L.; Miller, D.; Barquín, J.

    2011-09-01

    One of the major challenges in river restoration is to identify the natural fluvial landscape in catchments with a long history of river control. Intensive land use on valley floors often predates the earliest remote sensing: levees, dikes, dams, and other structures alter valley-floor morphology, river channels and flow regimes. Consequently, morphological patterns indicative of the fluvial landscape including multiple channels, extensive floodplains, wetlands, and fluvial-riparian and tributary-confluence dynamics can be obscured, and information to develop appropriate and cost effective river restoration strategies can be unavailable. This is the case in the Pas River catchment in northern Spain (650 km2), in which land use and development have obscured the natural fluvial landscape in many parts of the basin. To address this issue we used computer tools to examine the spatial patterns of fluvial landscapes that are associated with five domains of hydro-geomorphic processes and landforms. Using a 5-m digital elevation model, valley-floor surfaces were mapped according to elevation above the channel and proximity to key geomorphic processes. The predicted fluvial landscape is patchily distributed according to hillslope and valley topography, river network structure, and channel elevation profiles. The vast majority of the fluvial landscape in the main segments of the Pas River catchment is presently masked by human infrastructure, with only 15% not impacted by river control structures and development. The reconstructed fluvial landscape provides a catchment scale context to support restoration planning, in which areas of potential ecological productivity and diversity could be targeted for in-channel, floodplain and riparian restoration projects.

  9. Restoring Landform Geodiversity in Modified Rivers and Catchments

    Science.gov (United States)

    Smith, Ben; Clifford, Nicholas

    2014-05-01

    Extensive human modification and exploitation has created degraded and simplified systems lacking many of the landforms which would characterise healthy, geodiverse rivers. As awareness of geodiversity grows we must look to ways not only to conserve geodiversity but to also restore or create landforms which contribute to geodiverse environments. River restoration, with lessons learned over the last 30 years and across multiple continents, has much to offer as an exemplar of how to understand, restore or create geodiversity. Although not mentioned explicitly, there is an implicit emphasis in the Water Framework Directive on the importance of landforms and geodiversity, with landform units and assemblages at the reach scale assumed to provide the physical template for a healthy aquatic ecosystem. The focus on hydromorphology has increased the importance of geomorphology within river restoration programmes. The dominant paradigm is to restore landforms in order to increase habitat heterogeneity and improve biodiversity within rivers. However, the process of landform restoration is also a goal in its own right in the context of geodiversity, and extensive compilations of restoration experiences allow an inventory and pattern of landform (re-) creation to be assembled, and an assessment of landform function as well as landform presence/absence to be made. Accordingly, this paper outlines three principal research questions: Which landforms are commonly reinstated in river restoration activities? How do these landforms function compared to natural equivalents and thus contribute to 'functional' geodiversity as compared to the 'aesthetic' geodiversity? How does landform diversity scale from reach to catchment and contribute to larger-scale geodiversity? Data from the UK National River Restoration Inventory and the RHS are combined to assess the frequency and spatial distribution of commonly created landforms in relation to catchment type and more local context. Analysis is

  10. Creating a catchment scale perspective for river restoration

    Directory of Open Access Journals (Sweden)

    L. Benda

    2011-09-01

    Full Text Available One of the major challenges in river restoration is to identify the natural fluvial landscape in catchments with a long history of river control. Intensive land use on valley floors often predates the earliest remote sensing: levees, dikes, dams, and other structures alter valley-floor morphology, river channels and flow regimes. Consequently, morphological patterns indicative of the fluvial landscape including multiple channels, extensive floodplains, wetlands, and fluvial-riparian and tributary-confluence dynamics can be obscured, and information to develop appropriate and cost effective river restoration strategies can be unavailable. This is the case in the Pas River catchment in northern Spain (650 km2, in which land use and development have obscured the natural fluvial landscape in many parts of the basin. To address this issue we used computer tools to examine the spatial patterns of fluvial landscapes that are associated with five domains of hydro-geomorphic processes and landforms. Using a 5-m digital elevation model, valley-floor surfaces were mapped according to elevation above the channel and proximity to key geomorphic processes. The predicted fluvial landscape is patchily distributed according to hillslope and valley topography, river network structure, and channel elevation profiles. The vast majority of the fluvial landscape in the main segments of the Pas River catchment is presently masked by human infrastructure, with only 15% not impacted by river control structures and development. The reconstructed fluvial landscape provides a catchment scale context to support restoration planning, in which areas of potential ecological productivity and diversity could be targeted for in-channel, floodplain and riparian restoration projects.

  11. Technical Note: Automatic river network generation for a physically-based river catchment model

    Directory of Open Access Journals (Sweden)

    S. J. Birkinshaw

    2010-09-01

    Full Text Available SHETRAN is a physically-based distributed modelling system that gives detailed simulations in time and space of water flow and sediment and solute transport in river catchments. Standard algorithms for the automatic generation of river channel networks from digital elevation data are impossible to apply in SHETRAN and other similar models because the river channels are assumed to run along the edges of grid cells. In this work a new algorithm for the automatic generation of a river channel network in SHETRAN is described and its use in an example catchment demonstrated.

  12. Technical Note: Automatic river network generation for a physically-based river catchment model

    Science.gov (United States)

    Birkinshaw, S. J.

    2010-09-01

    SHETRAN is a physically-based distributed modelling system that gives detailed simulations in time and space of water flow and sediment and solute transport in river catchments. Standard algorithms for the automatic generation of river channel networks from digital elevation data are impossible to apply in SHETRAN and other similar models because the river channels are assumed to run along the edges of grid cells. In this work a new algorithm for the automatic generation of a river channel network in SHETRAN is described and its use in an example catchment demonstrated.

  13. Technical Note: Automatic river network generation for a physically-based river catchment model

    Directory of Open Access Journals (Sweden)

    S. J. Birkinshaw

    2010-05-01

    Full Text Available SHETRAN is a physically-based distributed modelling system that gives detailed simulations in time and space of water flow and sediment and solute transport in river catchments. Standard algorithms for the automatic generation of river channel networks from digital elevation data are impossible to apply in SHETRAN and other similar models because the river channels are assumed to run along the edges of grid cells. In this work a new algorithm for the automatic generation of a river channel network in SHETRAN is described and its use in an example catchment demonstrated.

  14. Technical Note: Automatic river network generation for a physically-based river catchment model

    OpenAIRE

    2010-01-01

    SHETRAN is a physically-based distributed modelling system that gives detailed simulations in time and space of water flow and sediment and solute transport in river catchments. Standard algorithms for the automatic generation of river channel networks from digital elevation data are impossible to apply in SHETRAN and other similar models because the river channels are assumed to run along the edges of grid cells. In this work a new algorithm for the automatic generation of a river cha...

  15. Technical Note: Automatic river network generation for a physically-based river catchment model

    OpenAIRE

    2010-01-01

    SHETRAN is a physically-based distributed modelling system that gives detailed simulations in time and space of water flow and sediment and solute transport in river catchments. Standard algorithms for the automatic generation of river channel networks from digital elevation data are impossible to apply in SHETRAN and other similar models because the river channels are assumed to run along the edges of grid cells. In this work a new algorithm for the automatic generation of a river channel ne...

  16. Vaal River catchment: problems and research needs

    CSIR Research Space (South Africa)

    Braune, E

    1987-01-01

    Full Text Available disappearance of chlorinated pesticides from the environment. Such surveys should be followed up in potential problem tributaries with intensive agricultural activity like the Harts River. Conservation and recreation Conservation Demands on the Vaal system... Spitskop Dam. 3.2.4 Rainfall stimulation The potential for rainfall and runoff enhancement through weather modification is being intensively investigated by the Weather Bureau of the Department of Environment Affairs in cooperation with the Department...

  17. RIVER WATER QUALITY IN THE LOWER CATCHMENT OF THE ARGEȘ RIVER

    Directory of Open Access Journals (Sweden)

    MARIANA SOARE

    2015-10-01

    Full Text Available The rivers water quality in the lower catchment area of Arges River varies from one sector to another, influenced by both natural and anthropic factors. In this context, the present paper, the surface waters were divided in quality categories as required by law. Thus, the ecological condition of river streams was evaluated on the basis of biological, chemical and phisico-chemical quality indicators and specific pollutant which have an influence on the biological indicators.

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

    Science.gov (United States)

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

    2009-08-15

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-08-15

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

  20. Don't fight the site: three geomorphic considerations in catchment-scale river rehabilitation planning.

    Science.gov (United States)

    Brierley, Gary; Fryirs, Kirstie

    2009-06-01

    Three geomorphic considerations that underpin the design and implementation of realistic and strategic river conservation and rehabilitation programs that work with the nature are outlined. First, the importance of appreciating the inherent diversity of river forms and processes is discussed. Second, river dynamics are appraised, framing the contemporary behavioral regime of a reach in relation to system evolution to explain changes to river character and behavior over time. Third, the trajectory of a reach is framed in relation to downstream patterns of river types, analyzing landscape connectivity at the catchment scale to interpret geomorphic river recovery potential. The application of these principles is demonstrated using extensive catchment-scale analyses of geomorphic river responses to human disturbance in the Bega and Upper Hunter catchments in southeastern Australia. Differing implications for reach- and catchment-scale rehabilitation planning prompt the imperative that management practices work with nature rather than strive to 'fight the site.'

  1. An estimation on budget and control of phosphorus in the Changjiang River catchment.

    Science.gov (United States)

    Shen, Zhi-Liang; Li, Zheng; Miao, Hui

    2012-11-01

    Based on field investigations in the Changjiang River mouth, rain sampling from the river's upper reaches to the mouth, historical data, and relevant literatures, the budget and major control factors of total phosphorus (TP) and dissolved inorganic phosphorus (DIP) in the river catchment were estimated and discussed from the catchment scale. It will supply a base for effective controlling P concentration in the Changjiang River and its mouth. Results show that the export fluxes of TP and DIP were mainly controlled by the river runoff. The TP and DIP in the Changjiang River came mainly from agricultural nonpoint source P losses from fertilizer and soil and point sources of industrial waste and residential sewage discharges. The export fluxes of TP and DIP in the river mouth were only 27.0% and 28.3% of the imports from the river catchment, respectively, suggesting that most of P were removed in transportation. A mass of freshwater marshes in the river catchment were the main areas to remove P. Significant increasing in utilization of fertilizer P and incessant increasing in water and soil loss areas were the primary reasons of agricultural nonpoint source P losses. How to decrease the agricultural nonpoint source P loss from the catchment scale is a key controlling P concentration in the Changjiang River and its mouth. The point source industrial waste P discharge has been primarily treated in the river catchment, but the residential sewage P discharge needs further control.

  2. Vulnerability of schools to floods in Nyando River catchment, Kenya.

    Science.gov (United States)

    Ochola, Samuel O; Eitel, Bernhard; Olago, Daniel O

    2010-07-01

    This paper assesses the vulnerability of schools to floods in the Nyando River catchment (3,600 km(2)) in western Kenya and identifies measures needed to reduce this vulnerability. It surveys 130 schools in the lower reaches, where flooding is a recurrent phenomenon. Of the primary schools assessed, 40% were vulnerable, 48% were marginally vulnerable and 12% were not vulnerable. Of the secondary schools, 8% were vulnerable, 73% were marginally vulnerable and 19% were not vulnerable. Vulnerability to floods is due to a lack of funds, poor building standards, local topography, soil types and inadequate drainage. The Constituencies Development Fund (CDF), established in 2003, provides financial support to cover school construction and reconstruction costs; CDF Committees are expected to adopt school building standards. In an effort to promote safe and resilient construction and retrofitting to withstand floods, this paper presents vulnerability reduction strategies and recommendations for incorporating minimum standards in the on-going Primary School Infrastructure Programme Design.

  3. Processes controlling the chromium isotopic composition of river water: Constraints from basaltic river catchments

    Science.gov (United States)

    D'Arcy, Joan; Babechuk, Michael G.; Døssing, Lasse Nørbye; Gaucher, Claudio; Frei, Robert

    2016-08-01

    We report chromium (Cr) isotope compositions and concentrations (and additional geochemical and physicochemical data) of bedrock, soils and river waters from two geographically distinct basaltic river catchments, the Uruguay River catchment (Uruguay) and the Glenariff River catchment (Northern Ireland, United Kingdom), to investigate the processes that control Cr mobilisation and fractionation during weathering and riverine transport to the sea. Our results show that the Cr isotope compositions of soils are a function of the modal abundance and weathering rates of Cr-bearing minerals. The accumulation of weathering resistant Cr-spinels in the soils of Northern Ireland results in soils which are enriched in Cr and have δ53Cr values within the range of local bedrock (δ53Cr value of -0.21 ± 0.12‰, 2σ, n = 4). By contrast, the more easily weathered Cr-silicates in the bedrock of Uruguay results in greater Cr loss from the soil and a depletion in the heavy isotopes of Cr (with average δ53Cr value of -0.32 ± 0.04‰, 2σ, n = 4) relative to the local bedrock (δ53Cr value of -0.22 ± 0.08‰, 2σ, n = 4). The river waters in both catchments are predominantly enriched in the heavy 53Cr isotope relative to bedrock, although the range and average river water δ53Cr values differ significantly between each. The Uruguay rivers exhibit a restricted range in δ53Cr values, with a mean of +0.08 ± 0.06‰ (2σ, n = 5) that represents a positive fractionation of +0.2‰ relative to bedrock, and is best explained by the unidirectional formation of Cr(VI) during weathering that has not been significantly modified by back-reduction to Cr(III). By contrast, the Glenariff stream and river waters (Northern Ireland) exhibit a wide range in δ53Cr values from -0.17 ± 0.3‰ (2σ, n = 4) to +1.68 ± 0.3‰ (n = 1) that appears to reflect the variable redox conditions of the catchment. In general, the values with the lowest 53Cr enrichment have higher Cr concentrations, the lowest

  4. A general protocol for restoration of entire river catchments

    Energy Technology Data Exchange (ETDEWEB)

    Stanford, J.A.; Frissell, C.A. [Univ. of Montana, Polson, MT (United States). Flathead Lake Biological Station; Ward, J.V. [EAWAG/ETH, Dubendorf (Switzerland). Dept. of Limnology; Liss, W.J. [Oregon State Univ., Corvallis, OR (United States). Dept. of Fisheries and Wildlife; Coutant, C.C. [Oak Ridge National Lab., TN (United States); Williams, R.N.; Lichatowich, J.A.

    1996-05-28

    Large catchment basins may be viewed as ecosystems with interactive natural and cultural attributes. Stream regulation severs ecological connectivity between channels and flood plains by reducing the range of natural flow and temperature variation, reduces the capacity of the ecosystem to sustain native biodiversity and bioproduction and promotes proliferation of non-native biota. However, regulated rivers regain normative attributes, which promote recovery of native biota, as distance from the dam increases and in relation to the mode of regulation. Therefore, reregulation of flow and temperature to normative pattern, coupled with elimination of pollutants and constrainment of nonnative biota, can naturally restore damaged habitats from headwaters to mouth. The expectation is rapid recovery of depressed populations of native species. The protocol requires: restoration of seasonal temperature patterns; restoration of peak flows needed to reconnect and periodically reconfigure channel and floodplain habitats; stabilization of base flows to revitalize the shallow water habitats; maximization of dam passage to allow restoration of metapopulation structure; change in the management belief system to rely on natural habitat restoration as opposed to artificial propagation, installation of artificial instream structures (river engineering) and artificial food web control; and, practice of adaptive ecosystem management.

  5. Internally Drained Supraglacial River Catchments on the Southwest Greenland Ice Sheet

    Science.gov (United States)

    Yang, K.; Smith, L. C.; Chu, V. W.; Pitcher, L. H.; Gleason, C. J.

    2015-12-01

    Internally drained catchments are the hydrologic units on the Greenland ice sheet (GrIS) surface that collect and drain meltwater into moulins or supraglacial lakes without out flows. Understanding the spatial pattern of these internal catchments is critical, which can provide key information about how supraglacial meltwater is transported and released on the ice surface. This study proposed an automatic approach to detect supraglacial hydrologic features (rivers, lakes, moulins, and internal catchments) located at southwest GrIS from Landsat-8 OLI panchromatic imagery. A total of 800 internal catchments are delineated and the average catchment size (river network length) is found to increase with elevations. In addition, moulins are the prime way to drain internal catchments and the average moulin densities decrease with elevations. Adaptive depression area thresholds are calculated to achieve optimal match between DEM-modeled and image-detected internal catchment patterns. The pattern of these image-detected internal catchments also indicates that: 1) not all the DEM-modeled topographic depressions act as meltwater sinks; 2) moulin distribution greatly impacts the internal catchment patterns; and 3) topographic depressions can be connected downstream without being fully filled, changing the fragmentary of the internal catchments.

  6. Ecohydrological modelling and integrated management planning in the catchment of the river Dommel

    NARCIS (Netherlands)

    Verkroost, A.W.M.; Olde Venterink, H.; Pieterse, N.M.; Schot, P.P.; Wassen, M.J.

    1998-01-01

    The EU-LIFE Dommel project aims at the development of methods for the combined use of landscape ecological models and socio-economic knowledge in the drawing up of integrated management plans for catchment areas of small trans-border rivers. These methods were developed and tested in the catchment a

  7. Influences on flood frequency distributions in Irish river catchments

    Science.gov (United States)

    Ahilan, S.; O'Sullivan, J. J.; Bruen, M.

    2012-04-01

    This study explores influences on flood frequency distributions in Irish rivers. A Generalised Extreme Value (GEV) type I distribution is recommended in Ireland for estimating flood quantiles in a single site flood frequency analysis. This paper presents the findings of an investigation that identified the GEV statistical distributions that best fit the annual maximum (AM) data series extracted from 172 gauging stations of 126 rivers in Ireland. Analysis of these data was undertaken to explore hydraulic and hydro-geological factors that influence flood frequency distributions. A hierarchical approach of increasing statistical power that used probability plots, moment and L-moment diagrams, the Hosking goodness of fit algorithm and a modified Anderson-Darling (A-D) statistical test was followed to determine whether a type I, type II or type III distribution was valid. Results of the Hosking et al. method indicated that of the 143 stations with flow records exceeding 25 yr, data for 95 (67%) was best represented by GEV type I distributions and a further 9 (6%) and 39 (27%) stations followed type II and type III distributions respectively. Type I, type II and type III distributions were determined for 83 (58%), 16 (11%) and 34 (24%) stations respectively using the modified A-D method (data from 10 stations was not represented by GEV family distributions). The influence of karst terrain on these flood frequency distributions was assessed by incorporating results on an Arc-GIS platform showing karst features and using Monte Carlo simulations to assess the significance of the number and clustering of the observed distributions. Floodplain effects were identified by using two-sample t-tests to identify statistical correlations between the distributions and catchment properties that are indicative of strong floodplain activity. The data reveals that type I distributions are spatially well represented throughout the country. While also well represented throughout the

  8. Influences on flood frequency distributions in Irish river catchments

    Directory of Open Access Journals (Sweden)

    S. Ahilan

    2012-04-01

    Full Text Available This study explores influences on flood frequency distributions in Irish rivers. A Generalised Extreme Value (GEV type I distribution is recommended in Ireland for estimating flood quantiles in a single site flood frequency analysis. This paper presents the findings of an investigation that identified the GEV statistical distributions that best fit the annual maximum (AM data series extracted from 172 gauging stations of 126 rivers in Ireland. Analysis of these data was undertaken to explore hydraulic and hydro-geological factors that influence flood frequency distributions. A hierarchical approach of increasing statistical power that used probability plots, moment and L-moment diagrams, the Hosking goodness of fit algorithm and a modified Anderson-Darling (A-D statistical test was followed to determine whether a type I, type II or type III distribution was valid. Results of the Hosking et al. method indicated that of the 143 stations with flow records exceeding 25 yr, data for 95 (67% was best represented by GEV type I distributions and a further 9 (6% and 39 (27% stations followed type II and type III distributions respectively. Type I, type II and type III distributions were determined for 83 (58%, 16 (11% and 34 (24% stations respectively using the modified A-D method (data from 10 stations was not represented by GEV family distributions. The influence of karst terrain on these flood frequency distributions was assessed by incorporating results on an Arc-GIS platform showing karst features and using Monte Carlo simulations to assess the significance of the number and clustering of the observed distributions. Floodplain effects were identified by using two-sample t-tests to identify statistical correlations between the distributions and catchment properties that are indicative of strong floodplain activity. The data reveals that type I distributions are spatially well represented throughout the country. While also well represented throughout

  9. New Information on the Malacofauna of the Catchment Area of Rusenski Lom River (North Bulgaria

    Directory of Open Access Journals (Sweden)

    Iltcho Kolev

    2015-12-01

    Full Text Available After this short note adding 8 species to the faunal list of the area, a total of 130 mollusk species are known from the catchment area of Rusenski Lom River both aquatic and terrestrial.

  10. Implementing integrated catchment management in the Limpopo River Basin Phase 1: Situational assessment

    CSIR Research Space (South Africa)

    Mwenge Kahinda, Jean-Marc

    2012-10-01

    Full Text Available integrated catchment management in the Limpopo River Basin Phase 1: Situational assessment J MWENGE KAHINDA, E KAPANGAZIWIRI, FA ENGELBRECHT, R MEISSNER AND PJ ASHTON CSIR Natural Resources and the Environment, PO Box 395, Pretoria, South Africa, 0001... Email: jmwengekahinda@csir.co.za ? www.csir.co.za BACKGROUND The project aims to promote Integrated Catchment Management approaches in the Limpopo River Basin (Figure 1) in three phases: 1) Situational assessment: develop a sound spatial...

  11. Management of human-induced salinization in the Berg River catchment (South Africa)

    CSIR Research Space (South Africa)

    Jovanovic, Nebojsa

    2010-09-01

    Full Text Available of different crop rotations 2) Goedertrou small scale catchment: hydrosalinity fluxes 3) Voelvlei Nature Reserve: evapotranspiration of endemic renosterveld vegetation and adjacent wheat field The results obtained from the intensive monitoring sites served... with different crop rotations Goedertrou 20 ha catchment Endemic renosterveld at Voelvlei Nature Reserve Sandspruit river Berg river Figure 4: Relationship between mean annual precipitation and groundwater salinity (electrical conductivity EC class...

  12. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: Bedrock Geology

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This tabular data set represents the area of bedrock geology types in square meters compiled for every catchment of MRB_E2RF1 catchments for Major River Basins...

  13. Influences on flood frequency distributions in Irish river catchments

    Directory of Open Access Journals (Sweden)

    S. Ahilan

    2011-04-01

    presence of karst in river catchments would be expected to provide additional subsurface storage and in this regard, type III distributions might be expected. The prevalence of type II distributions in this area reflects the finite nature of this storage and the effects, in extreme conditions, when the karst is saturated and further storage is no longer available. Results therefore indicate that in some instances assuming type I distributions is incorrect and may result in erroneous estimates of flood quantiles in these regions. Where actual data follows a type II distribution, flood quantiles may be underestimated and for type III distributions, overestimates may be expected.

  14. Groundwater as an emergency source for drought mitigation in the Crocodile River catchment, South Africa

    Directory of Open Access Journals (Sweden)

    F. E. F. Mussá

    2014-03-01

    and environmental damages to the society. In this study, we assess the drought intensity and severity and the groundwater potential to be used as a supplement source of water to mitigate drought impacts in the Crocodile River catchment, a water-stressed sub-catchment of the Incomati River catchment in South Africa. The research methodology consists mainly of three parts. First, the spatial and temporal variation of the meteorological and hydrological drought severity and intensity over the catchment were evaluated. The Standardized Precipitation Index (SPI was used to analyse the meteorological drought and the Standardized Runoff Index (SRI was used for the hydrological drought. Second, the water deficit in the catchment during the drought period was computed using a simple water balance method. Finally, a groundwater model was constructed in order to assess the feasibility of using groundwater as an emergency source for drought impact mitigation. Results show that the meteorological drought severity varies accordingly with the precipitation; the low rainfall areas are more vulnerable to severe meteorological droughts (lower and upper crocodile. Moreover, the most water stressed sub-catchments with high level of water uses but limited storage, such as the Kaap located in the middle catchment and the Lower Crocodile sub-catchments are those which are more vulnerable to severe hydrological droughts. The analysis of the potential groundwater use during droughts showed that a deficit of 97 Mm3 yr−1 could be supplied from groundwater without considerable adverse impacts on the river base flow and groundwater storage. Abstraction simulations for different scenarios of extremely severe droughts reveal that it is possible to use groundwater to cope with the droughts in the catchment. However, local groundwater exploitation in Nelspruit and White River sub-catchment will cause large drawdowns (> 10 m and high base flow reduction (> 20%. This case study shows that

  15. Modelling runoff dynamics from information on river network and shape of catchment area

    Science.gov (United States)

    Skaugen, T.

    2009-12-01

    In a new approach, the dynamics of discharge is derived from the distribution of distances to the nearest river reach within a natural catchment. The river network and the shape of catchment provide a unique distribution function for each catchment which can be determined from a GIS. The distribution can be considered as a detailed description of the drainage density, where the location of the river relative to the catchment is taken into account. Within a fixed time interval, water flows through the catchment a certain distance which defines a fractional area. This fraction is estimated as an area enveloping the river network, whose width, perpendicular to the river network, is determined for the time interval of interest by the flow velocity. For a constant flow velocity, the time steps define adjacent areas which , for a sufficient number of time intervals, cover the entire catchment. For different flow velocities, we have different horizontal layers and the total discharge is the sum of discharge from each of the layers for each time step. The proposed principle for modelling the dynamics of discharge is implemented in the Swedish HBV model. The new model, named 3D (distance distribution dynamics), has the same precision as the HBV model but requires fewer parameters and represents thus a step in the right direction for meeting the challenge of predictions in ungauged basins.

  16. C, N, P export regimes in rivers from headwater to downstream catchments

    Science.gov (United States)

    Dupas, Rémi; Musolff, Andreas; Jawitz, James W.; Rao, P. Suresh C.; Fleckenstein, Jan H.; Rode, Michael; Borchardt, Dietrich

    2017-04-01

    Excessive amounts of nutrients and dissolved organic matter in freshwater bodies affect aquatic ecosystems. In this study, the spatial and temporal variability of nitrate (NO3), dissolved organic carbon (DOC) and soluble reactive phosphorus (SRP) was analyzed along the Selke river continuum from 1 - 3 km2 headwater catchments to 184 - 456 km2 downstream catchments, within the TERENO Harz/Central German Lowland Observatory. Three headwater catchments were selected as archetypes of the main landscape units (land use x soil type) present in the Selke catchment. Export regimes in these catchments were interpreted in terms of NO3, DOC and SRP land-to-stream transfer processes. Differences between export regimes in headwater and downstream catchments were interpreted in terms of in-stream processes and contribution of point source emissions. The results showed that the NO3 seasonal dynamics were opposite compared to DOC and SRP in all three headwater catchments. These dynamics were interpreted as the result of the interplay of hydrological and biogeochemical processes, for which riparian wetlands were hypothesized to play a determining role. In the two downstream catchments, NO3 was transported almost conservatively, except during the summer period where in-stream retention could exceed 50%. Allochtonous DOC was consumed in the upstream river section (with low light and nutrient availability) and autochthonous DOC was produced in the downstream river section (with high light and nutrients availability); the natural export regime of SRP mimicked a point source signal, which may lead to misattribution and thus overestimation of domestic contribution to phosphorus loads in rivers. Monitoring the river continuum from headwater to downstream rivers proved effective to investigate jointly land-to-stream and in-stream transport and transformation processes.

  17. An INCA model for pathogens in rivers and catchments: Model structure, sensitivity analysis and application to the River Thames catchment, UK.

    Science.gov (United States)

    Whitehead, P G; Leckie, H; Rankinen, K; Butterfield, D; Futter, M N; Bussi, G

    2016-12-01

    Pathogens are an ongoing issue for catchment water management and quantifying their transport, loss and potential impacts at key locations, such as water abstractions for public supply and bathing sites, is an important aspect of catchment and coastal management. The Integrated Catchment Model (INCA) has been adapted to model the sources and sinks of pathogens and to capture the dominant dynamics and processes controlling pathogens in catchments. The model simulates the stores of pathogens in soils, sediments, rivers and groundwaters and can account for diffuse inputs of pathogens from agriculture, urban areas or atmospheric deposition. The model also allows for point source discharges from intensive livestock units or from sewage treatment works or any industrial input to river systems. Model equations are presented and the new pathogens model has been applied to the River Thames in order to assess total coliform (TC) responses under current and projected future land use. A Monte Carlo sensitivity analysis indicates that the input coliform estimates from agricultural sources and decay rates are the crucial parameters controlling pathogen behaviour. Whilst there are a number of uncertainties associated with the model that should be accounted for, INCA-Pathogens potentially provides a useful tool to inform policy decisions and manage pathogen loading in river systems. Copyright © 2016. Published by Elsevier B.V.

  18. Analyzing catchment behavior through catchment modeling in the Gilgel Abay, Upper Blue Nile River Basin, Ethiopia

    Directory of Open Access Journals (Sweden)

    S. Uhlenbrook

    2010-10-01

    Full Text Available Understanding catchment hydrological processes is essential for water resources management, in particular in data scarce regions. The Gilgel Abay catchment (a major tributary into Lake Tana, source of the Blue Nile is undergoing intensive plans for water management, which is part of larger development plans in the Blue Nile basin in Ethiopia. To obtain a better understanding of the water balance dynamics and runoff generation mechanisms and to evaluate model transferability, catchment modeling has been conducted using the conceptual hydrological model HBV. Accordingly, the catchment of the Gilgel Abay has been divided into two gauged sub-catchments (Upper Gilgel Abay and Koga and the un-gauged part of the catchment. All available data sets were tested for stationarity, consistency and homogeneity and the data limitations (quality and quantity are discussed. Manual calibration of the daily models for three different catchment representations, i.e. (i lumped, (ii lumped with multiple vegetation zones, and (iii semi-distributed with multiple vegetation and elevation zones, showed good to satisfactory model performances with Nash-Sutcliffe efficiencies Reff > 0.75 and > 0.6 for the Upper Gilgel Abay and Koga sub-catchments, respectively. Better model results could not be obtained with manual calibration, very likely due to the limited data quality and model insufficiencies. Increasing the computation time step to 15 and 30 days improved the model performance in both sub-catchments to Reff > 0.8. Model parameter transferability tests have been conducted by interchanging parameters sets between the two gauged sub-catchments. Results showed poor performances for the daily models (0.30 < Reff < 0.67, but better performances for the 15 and 30 days models, Reff > 0.80. The transferability tests together with a sensitivity analysis using Monte Carlo simulations (more than 1 million

  19. Response of Stream Pollution Characteristics to Catchment Land Cover in Cao-E River Basin, China

    Institute of Scientific and Technical Information of China (English)

    SHEN Ye-Na; L(U) Jun; CHEN Ding-Jiang; SHI Yi-Ming

    2011-01-01

    This study addressed the relationship of river water pollution characteristics to land covers and human activities in the catchments in a complete river system named Cao-E River in eastcrn China. Based on the hydrogsochemical data collected monthly over a period of 3 years, cluster analysis (CA) and principal component analysis (PCA) were adopted to categorize the river reaches and reveal their pollution characteristics. According to the differences of water quality in the river reaches and land use patterns and average population densities in their catchments, the whole river system could be categorized into three groups of river reaches, i.e., non-point sources pollution reaches (NPSPR), urban reaches (UR) and mixed sources pollution reaches (MSPR). In UR and MSPR, the water quality was mainly impacted by nutrient and organic pollution, while in NPSPR nutrient pollution was the main cause. The nitrate was the main nitrogen form in NPSPR and particulate phosphorus was the main phosphorus form in MSPR. There were no apparent trends for the variations of pollutant concentrations with increasing river flows in NPSPR and MSPR, while in UR the pollutant concentrations decreased with increasing river flows. Thus dry season was the critical period for water pollution control in UR. Therefore, catchment land covers and human activities had significant impact on river reach water pollution type, nutrient forms and water quality responses to hydrological conditions, which might be crucial for developing strategies to combat water pollution in watershed scale.

  20. Seasonal contribution of terrestrial organic matter and biological oxygen demand to the Baltic Sea from three contrasting river catchments

    DEFF Research Database (Denmark)

    Reader, H. E.; Stedmon, C. A.; Kritzberg, E. S.

    2014-01-01

    To examine the potential influence of terrestrially derived DOM on the Baltic Sea, a year-long study of dissolved organic matter (DOM) was performed in three river catchments in Sweden. One catchment drains into the Bothnian Sea, while two southern catchments drain into the Baltic proper. Dissolved...... on the same order of magnitude for all three catchments. Biological oxygen demand (BOD) was used as a proxy for the lability of carbon in the system. The range of BOD values was similar for all three catchments, however, the ratio of BOD to DOC (an indication of the labile fraction) in Ume river was four...

  1. Catchment2Coast: making the link between coastal resource variability and river inputs

    CSIR Research Space (South Africa)

    Monteiro, P

    2003-07-01

    Full Text Available boundaries, including the tradi- tional ones between river catchments and their adjacent coastal ecosystems. The Catchment2Coast Project aims to address these gaps in knowledge using a combination of numerical modelling and field observations... refinement of numerical modelling plat- forms, affording them the necessary degree of rigour and reliability for more generic usage as management and policy development support tools. The project uses as a case study the Incomati River–Maputo Bay system...

  2. Impact on ecotourism by water pollution in the Olifants River catchment, South Africa

    CSIR Research Space (South Africa)

    Oberholster, Paul J

    2009-12-01

    Full Text Available . Olifants R. Olifants R. W ilge R. Sa alboomsp ru it R . Namibia Botswana Lesotho Swaziland Mozambique South Africa Bro nkh ors tsp ru it R . Steenkoolspruit R. T rich ard tsp ru it R . Vi sku ile R . Rie tsp rui t R... . T rich ard tsp ru it R . Figure 1. Sketch map showing the Upper Olifants River catchment with Lake Loskop. Inset map shows the area within South Africa; the dashed line separates the Wilge sub-catchment from the Olifants sub-catchment. SILnews 55...

  3. Gis Approach to Estimation of the Total Phosphorous Transfer in the Pilica River Lowland Catchment

    Directory of Open Access Journals (Sweden)

    Magnuszewski Artur

    2014-09-01

    Full Text Available In this paper, the Pilica River catchment (central Poland is analyzed with a focus on understanding the total phosphorous transfer along the river system which also contains the large artificial Sulejów Reservoir. The paper presents a GIS method for estimating the total phosphorous (TP load from proxy data representing sub-catchment land use and census data. The modelled load of TP is compared to the actual transfer of TP in the Pilica River system. The results shows that the metrics of connectivity between river system and dwelling areas as well as settlement density in the sub-catchments are useful predictors of the total phosphorous load. The presence of a large reservoir in the middle course of the river can disrupt nutrient transport along a river continuum by trapping and retaining suspended sediment and its associated TP load. Analysis of the indirect estimation of TP loads with the GIS analysis can be useful for identifying beneficial reservoir locations in a catchment. The study has shown that the Sulejów Reservoir has been located in a subcatchment with a largest load of the TP, and this feature helps determine the problem of reservoir eutrphication

  4. Distribution and diversity of fungi in freshwater sediments on a river catchment scale.

    Science.gov (United States)

    Liu, Jie; Wang, Jianan; Gao, Guanghai; Bartlam, Mark G; Wang, Yingying

    2015-01-01

    Fungal communities perform essential functions in biogeochemical cycles. However, knowledge of fungal community structural changes in river ecosystems is still very limited. In the present study, we combined culture-dependent and culture-independent methods to investigate fungal distribution and diversity in sediment on a regional scale in the Songhua River catchment, located in North-East Asia. A total of 147 samples over the whole river catchment were analyzed. The results showed that compared to the mainstream, the tributaries have a higher fungal community organization and culturable fungal concentration, but possess lower community dynamics as assessed by denaturing gradient gel electrophoresis (DGGE). Furthermore, phylogenetic analysis of DGGE bands showed that Ascomycota and Basidiomycota were the predominant community in the Songhua River catchment. Redundancy analysis revealed that longitude was the primary factor determining the variation of fungal community structure, and fungal biomass was mainly related to the total nutrient content. Our findings provide new insights into the characteristics of fungal community distribution in a temperate zone river at a regional scale, and demonstrate that fungal dispersal is restricted by geographical barriers in a whole river catchment.

  5. Lowland forest butterflies of the Sankosh River catchment, Bhutan

    Directory of Open Access Journals (Sweden)

    A.P. Singh

    2012-10-01

    Full Text Available This paper provides information on butterflies of the lowland forests of Bhutan for the first time. As a part of the biodiversity impact assessment for the proposed Sankosh hydroelectric power project, a survey was carried out along the Sankosh River catchment to study the butterfly diversity. The aim of the study was to identify species of conservation priority, their seasonality and to know the butterfly diversity potential of the area. Surveys were carried out during five different seasons (winter, spring, pre-monsoon, monsoon, post-monsoon lasting 18 days from January 2009 to March 2010. Pollard walk method was used to assess the diversity on four-line transects within 10-12 km radius of the proposed dam site. Two hundred and thirteen species, including 22 papilionids, were thus sampled. Eleven species amongst these are listed in Schedules I and II of the Indian Wildlife (Protection Act, 1972, of which 10 taxa (Pareronia avatar avatar, Nacaduba pactolus continentalis, Porostas aluta coelestis, Elymnias vasudeva vasudeva, Mycalesis mestra retus, Melanitis zitenius zitenius, Charaxes marmax, Athyma ranga ranga, Neptis manasa manasa and Neptis soma soma are of conservation priority as they are ‘rare’ in occurrence across their distribution range in the region. The maximum number of species (128 were recorded during the spring season (March and lowest (66 during July (monsoon. The seasonal pattern of variation in diversity was very typical of the pattern found in other areas of the lower foothills and adjoining plains of the Himalaya. Relative abundances of butterflies during spring varied significantly (p<0.05 as compared to winter, pre-monsoon and post-monsoon seasons. However, species composition changed with every season as Sorensen’s similarity index varied between 0.3076 to 0.5656. All these findings suggest that the lowland forests of Bhutan hold a rich and unique diversity of butterflies during every season of the year thus having

  6. Trend analysis of nutrient loadings in the South Saskatchewan River catchment

    Science.gov (United States)

    Morales-Marin, L. A.; Chun, K. P.; Wheater, H. S.; Lindenschmidt, K. E.

    2015-12-01

    Nutrient loadings in river catchments have increased in the past years as a consequence of rapid expansion of agricultural areas, new urban developments and industries, and population growth. Nutrient enrichment of water bodies has intensified eutrophication conditions that degrade water quality and ecosystem health. In large-scale catchments, the assessment of temporal and spatial variability of nutrient loads imply challenges due to climate, land use and geology heterogeneity, and to anthropogenic changes. In this study we carried out a trend analysis of total phosphorus and total nitrogen loads in the South Saskatchewan River (SSR) catchment. This catchment is located in the Canadian Prairie Provinces of Alberta and Saskatchewan. The eastern and central areas of the catchment consist mostly of croplands, pasture lands and livestock farms, whereas the western parts are located on the Rocky Mountains that are the source of most of the catchment's streamflows. The trend analysis was performed applying a novel approach to analyse nutrient time series recorded at long-term water quality stations along the main stems of the SSR river network. Since water quality is taken infrequently, in the proposed approach the time series were complemented using regression analysis methods based on streamflow data recorded at the nearest gauge stations. The time series were subsequently pre-whitened in order to remove the autocorrelation, and then subjected to non-parametric statistical test to detect trends. Seasonal analysis of trends at each of the water quality stations were performed in order to determine the relationships between annual flow regimes and nutrient loads in the catchment, in particular, the influence of the high spring runoff on nutrient export. Decadal analysis was also performed to determine the long-tern relationships of nutrients with anthropogenic changes in the catchment. In particular, the capacity of reservoirs to trap nutrients and the effects of the

  7. From river to ridge: a blueprint for sustainable management in the Georges River catchment.

    Science.gov (United States)

    Nimmo, J

    2001-01-01

    Research on sustainable transport and water projects, conducted in North America during 1999, identified four key considerations common to a number of projects. These four considerations are the preconditions necessary to achieve sustainability in a given location. These preconditions (BAPP) are boundary definition, administrative alignment, protection of non-urban lands, and the participation of all interested parties. This paper considers the perceived attitudes of various catchment stakeholders and focuses on planners and planning. The results of questionnaire surveys based on BAPP concepts suggest that local government is perceived as having the highest priority for protection of riparian lands and waterways (as individual Councils and Regional Organisations of Councils). Thus local government is the preferred arena for coordination, responsibility and jurisdiction of waterways and riparian land. The opportunity exists to examine the differing roles of local and state government. The paper concludes by outlining the implications of this research for land use planning and institutional structures in sustainable river management.

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

    Science.gov (United States)

    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

  9. Quantification and Genotyping of Human Sapoviruses in the Llobregat River Catchment, Spain▿ †

    Science.gov (United States)

    Sano, Daisuke; Pérez-Sautu, Unai; Guix, Susana; Pintó, Rosa Maria; Miura, Takayuki; Okabe, Satoshi; Bosch, Albert

    2011-01-01

    Human sapoviruses (SaVs) were quantified and characterized in an 18-month survey conducted along the Llobregat river catchment area in Spain. Sample types included freshwater, untreated and treated wastewater, and drinking water. All genogroups were recovered, and a seasonal distribution was observed. This is the first report of SaV quantification and genotyping in the environment outside Japan. PMID:21148702

  10. Quantification and Genotyping of Human Sapoviruses in the Llobregat River Catchment, Spain▿ †

    OpenAIRE

    Sano, Daisuke; Pérez-Sautu, Unai; Guix, Susana; Pintó, Rosa Maria; Miura, Takayuki; Okabe, Satoshi; Bosch, Albert

    2010-01-01

    Human sapoviruses (SaVs) were quantified and characterized in an 18-month survey conducted along the Llobregat river catchment area in Spain. Sample types included freshwater, untreated and treated wastewater, and drinking water. All genogroups were recovered, and a seasonal distribution was observed. This is the first report of SaV quantification and genotyping in the environment outside Japan.

  11. Vegetation NDVI Linked to Temperature and Precipitation in the Upper Catchments of Yellow River

    NARCIS (Netherlands)

    Hao, F.; Zhang, X.; Ouyang, W.; Skidmore, A.K.; Toxopeus, A.G.

    2012-01-01

    Vegetation in the upper catchment of Yellow River is critical for the ecological stability of the whole watershed. The dominant vegetation cover types in this region are grassland and forest, which can strongly influence the eco-environmental status of the whole watershed. The normalized difference

  12. Implementing Integrated Catchment Management in the upper Limpopo River basin: A situational assessment

    CSIR Research Space (South Africa)

    Mwenge Kahinda, Jean-Marc

    2015-10-01

    Full Text Available A three-phase study was initiated as a way to promote Integrated Catchment Management approaches in the Limpopo River basin. This paper presents the situational assessment, which should enable De Beers to understand how their Venetia Mine operations...

  13. Organochlorine pesticide residue levels in soil from the Nyando river catchment, Kenya

    NARCIS (Netherlands)

    Abong'o, D.A.; Wandiga, S.O.; Jumba, I.O.; Brink, van den P.J.; Nazariwo, B.B.; Madadi, V.O.; Wafula, H.; Kylin, H.

    2015-01-01

    Soil samples were collected from six locations representative of the Nyando River catchment area of the Lake Victoria over a period of two years. Sampling was done four times in the year in February, May, September and December 2005 and 2006 in farms where maize, tea, sugar cane, coffee, rice and ve

  14. Documenting success stories of management of phosphorus emissions at catchment scale: an example from the pilot river Odense, Denmark.

    Science.gov (United States)

    Kronvang, B; Tornbjerg, H; Hoffmann, C C; Poulsen, J R; Windolf, J

    2016-11-01

    Documentation of the effects of different mitigation measures adopted at different scales to reduce phosphorus (P) loadings to surface waters is needed to help catchment managers select the best management practices. Water quality monitoring data from the outlets of two paired catchments (the river Odense catchment versus a neighbouring control catchment) on the island of Funen, Denmark, showed significantly different trends in annual flow-weighted P concentrations during the period 2000-2013. A significant downward trend in flow-weighted particulate P (PP) concentrations (0.051 mg P L(-1)) and loss (0.155 kg P ha(-1)) was detected for the river Odense catchment, whereas a similar trend did not emerge in the control catchment. The observed differences in PP reductions may be due to wetlands acting as P sinks since wetland restoration activities have been much more comprehensive in the river Odense catchment (1.8 ha wetlands km(-2)) than in the control catchment (0.5 ha wetland km(-2)). The excess downward trend in total P and PP in the river Odense catchment (5,600 kg P and 3,700 kg P) is corroborated by extrapolating the results from a mass-balance study and 10 years of in situ measurements of P storage (3,700 kg P and 15,000 kg P).

  15. The runoff declining process and water quality in songhuajiang river catchment, China under global climatic change

    Energy Technology Data Exchange (ETDEWEB)

    Mu, Xingmin; Gao, Peng; Wang, Fei [Northwest A and F University, Yangling (China); Institute of Soil and Water Conservation, Chinese Academy of Sciences (CAS), Yangling (China); Li, Ying [Northwest A and F University, Yangling (China); Shao, Hongbo [The CAS/Shandong Provincial Key Laboratory of Coastal Environmental Processes, Yantai Institute of Costal Zone Research, Chinese Academy of Sciences (CAS), Yantai (China); Institute for Life Sciences, Qingdao University of Science and Technology (QUST), Qingdao (China)

    2012-04-15

    The runoff in Songhuajiang River catchment has experienced a decreasing trend during the second half of the 20th century. Serially complete daily rainfall data of 42 rainfall stations from 1959 to 2002 and daily runoff data of five meteorological stations from 1953 to 2005 were obtained. The Mann-Kendall trend test and the sequential version of Mann-Kendall test were employed in this study to test the monthly and annual trends for both rainfall and runoff, to determine the start point of abrupt runoff declining, and to identify the main driving factors of runoff decline. The results showed an insignificant increasing trend in rainfall but a significant decreasing trend in runoff in the catchment. For the five meteorological stations, abrupt runoff decline occurred during 1957-1963 and the middle 1990s. Through Mann-Kendall comparisons for the area-rainfall and runoff for the two decreasing periods, human activity, rather than climatic change, is identified as the main driving factor of runoff decline. Analysis of land use/cover shows that farmland is most related with runoff decline among all the land use/cover change in Nenjiang catchment. From 1986 to 1995, the area of farmland increased rapidly from 6.99 to 7.61 million hm{sup 2}. Hydraulic engineering has a significant influence on the runoff decline in the second Songhuajiang catchment. Many large-scale reservoirs and hydropower stations have been built in the upstream of the Second Songhuajiang and lead to the runoff decline. Nenjiang and the Second Songhuajiang are the two sources of mainstream of Songhuajiang. Decreased runoff in these two sub-catchments then results in runoff decrease in mainstream of Songhuajiang catchment. It is, therefore, concluded that high percent agricultural land and hydraulic engineering are the most probable driving factors of runoff decline in Songhuajiang River catchment, China. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. Comparative metagenomics reveals a diverse range of antimicrobial resistance genes in effluents entering a river catchment.

    Science.gov (United States)

    Rowe, Will; Verner-Jeffreys, David W; Baker-Austin, Craig; Ryan, Jim J; Maskell, Duncan J; Pearce, Gareth P

    2016-01-01

    The aquatic environment has been implicated as a reservoir for antimicrobial resistance genes (ARGs). In order to identify sources that are contributing to these gene reservoirs, it is crucial to assess effluents that are entering the aquatic environment. Here we describe a metagenomic assessment for two types of effluent entering a river catchment. We investigated the diversity and abundance of resistance genes, mobile genetic elements (MGEs) and pathogenic bacteria. Findings were normalised to a background sample of river source water. Our results show that effluent contributed an array of genes to the river catchment, the most abundant being tetracycline resistance genes tetC and tetW from farm effluents and the sulfonamide resistance gene sul2 from wastewater treatment plant (WWTP) effluents. In nine separate samples taken across 3 years, we found 53 different genes conferring resistance to seven classes of antimicrobial. Compared to the background sample taken up river from effluent entry, the average abundance of genes was three times greater in the farm effluent and two times greater in the WWTP effluent. We conclude that effluents disperse ARGs, MGEs and pathogenic bacteria within a river catchment, thereby contributing to environmental reservoirs of ARGs.

  17. Spatiotemporal variability of oxygen isotope compositions in three contrasting glacier river catchments in Greenland

    DEFF Research Database (Denmark)

    Knudsen, N. Tvis; Yde, J.C.; Steffensen, J.P.

    2015-01-01

    composition is controlled by the proportion between snowmelt and ice melt with episodic inputs of rainwater and occasional storage and release of a specific water component due to changes in the subglacial drainage system. At Kuannersuit Glacier River on the island Qeqertarsuaq, the δ18O characteristics were...... examined after the major 1995–1998 glacier surge event. Despite large variations in the δ18O values of glacier ice on the newly formed glacier tongue, there were no diurnal oscillations in the bulk meltwater emanating from the glacier in the post-surge years 2000–2001. In 2002 there were indications...... of diurnal oscillations, and in 2003 there were large diurnal fluctuations in δ18O. At Watson River, a large catchment at the western margin of the Greenland Ice Sheet, the spatial distribution of δ18O in the river system was applied to fingerprint the relative runoff contributions from sub-catchments. Spot...

  18. Integrated assessment of land use and cover changes in the Malagarasi river catchment in Tanzania

    Science.gov (United States)

    Kashaigili, J. J.; Majaliwa, A. M.

    Malagarasi river catchment represents one of the largest and most significant transboundary natural ecosystems in Africa. The catchment constitutes about one third of the catchment area of Lake Tanganyika and contains ecosystems of both national and international importance (i.e. Muyovozi Wetland Ramsar site). It has been increasingly said that increased anthropogenic activities have had negative impacts on the Muyovozi wetland in particular and other catchment resources. Nevertheless, these beliefs are little supported by quantitative data. A study on the dynamics of land use and cover in the Malagarasi river catchment therefore investigated long-term and seasonal changes that have occurred as a result of human activities in the area for the periods between 1984 and 2001. Landsat TM and ETM+ images were used to locate and quantify the changes. Perceptions of local people on historical changes and drivers for the changes were also collected and integrated in the assessment. The study revealed a significant change in land use and cover within a period of 18 year. Between 1984 and 2001, the woodland and wetland vegetation covers declined by 0.09% and 2.51% per year. Areas with settlements and cultivation increased by 1.05% annually while bushed grassland increased at 1.93% annually. The perceived principal drivers for the changes were found to include fire, cultivation along rivers and lake shores, overgrazing, poor law enforcement, insufficient knowledge on environmental issues, increasing poverty, deforestation and population growth. The human population growth rate stands at 4.8% against a national figure of 2.9%. The most perceived environmental problems include drying of streams and rivers, change in rainfall, loss of soil fertility, soil erosion and reduced crop yield. The study concludes that, there has been significant changes in land use and cover in the catchment and these require concerted actions to reverse the changes. The study highlights the importance

  19. Fluoroquinolones in the Wenyu River catchment, China: Occurrence simulation and risk assessment.

    Science.gov (United States)

    Hao, Xuewen; Cao, Yan; Zhang, Lai; Zhang, Yongyong; Liu, Jianguo

    2015-12-01

    Concern is increasing regarding the environmental impact of the high usage rate and intensive release of antibiotics used for human and animal therapy in major urban areas of China. In the present study, regional environmental distribution simulations and risk assessments for 3 commonly used fluoroquinolones in the Wenyu River catchment were conducted using a typical catchment model widely used in Europe. The fluoroquinolone antibiotics investigated (ofloxacin, norfloxacin, and ciprofloxacin) are consumed at high levels for personal health care in China. These antibiotics were simulated in the aquatic environment of the Wenyu River catchment across the Beijing City area for annual average concentrations, with regional predicted environmental concentrations (PECs) of approximately 711 ng/L, 55.3 ng/L, and 22.2 ng/L and local PECs up to 1.8 µg/L, 116 ng/L, and 43 ng/L, respectively. Apart from hydrological conditions, the concentrations of fluoroquinolones were associated closely with the sewage treatment plants (STPs) and their serving population, as well as hospital distributions. The presence of these fluoroquinolones in the catchment area of the present study showed significant characteristics of the occurrence of pharmaceuticals in the aquatic environment in an urban river, with typical "down-the-drain" chemicals. Significantly high concentrations of specific antibiotics indicated non-negligible risks caused by the intensive use in the local aquatic environment in a metropolitan area, particularly ofloxacin in upstream Shahe Reservoir, middle stream and downstream Qing River, and Liangma River to the Ba River segment. Specific treatment measures for these pharmaceuticals and personal care products in STPs are required for such metropolitan areas. © 2015 SETAC.

  20. Changing trends of rainfall and sediment fluxes in the Kinta River catchment, Malaysia

    Science.gov (United States)

    Ismail, W. R.; Hashim, M.

    2015-03-01

    The Kinta River, draining an area of 2566 km2, originates in the Korbu Mountain in Perak, Malaysia, and flows through heterogeneous, mixed land uses ranging from extensive forests to mining, rubber and oil palm plantations, and urban development. A land use change analysis of the Kinta River catchment was carried out together with assessment of the long-term trend in rainfall and sediment fluxes. The Mann-Kendall test was used to examine and assess the long-term trends in rainfall and its relationship with the sediment discharge trend. The land use analysis shows that forests, water bodies and mining land declined whilst built and agricultural land use increased significantly. This has influenced the sediment flux of the catchment. However, most of the rainfall stations and river gauging stations are experiencing an increasing trends, except at Kinta river at Tg. Rambutan. Sediment flux shows a net erosion for the period from 1961 to 1969. The total annual sediment discharge in the Kinta River catchment was low with an average rate of 1,757 t/km2/year. From 1970 to 1985, the annual sediment yield rose to an average rate of 4062 t/km2/year. Afterwards, from 1986 to 1993, the total annual sediment discharge decreased to an average rate of 1,306 t/km2/year and increased back during the period 1994 to 2000 to 2109 t/km2/year. From 2001 to 2006 the average sediment flux rate declined to 865 t/km2/year. The decline was almost 80% from the 1970s. High sediment flux in the early 1970s is partly associated with reduced tin mining activities in the area. This decreasing trend in sediment delivery leaving the Kinta River catchment is expected to continue dropping in the future.

  1. Advancing Land-Sea Conservation Planning: Integrating Modelling of Catchments, Land-Use Change, and River Plumes to Prioritise Catchment Management and Protection.

    Science.gov (United States)

    Álvarez-Romero, Jorge G; Pressey, Robert L; Ban, Natalie C; Brodie, Jon

    2015-01-01

    Human-induced changes to river loads of nutrients and sediments pose a significant threat to marine ecosystems. Ongoing land-use change can further increase these loads, and amplify the impacts of land-based threats on vulnerable marine ecosystems. Consequently, there is a need to assess these threats and prioritise actions to mitigate their impacts. A key question regarding prioritisation is whether actions in catchments to maintain coastal-marine water quality can be spatially congruent with actions for other management objectives, such as conserving terrestrial biodiversity. In selected catchments draining into the Gulf of California, Mexico, we employed Land Change Modeller to assess the vulnerability of areas with native vegetation to conversion into crops, pasture, and urban areas. We then used SedNet, a catchment modelling tool, to map the sources and estimate pollutant loads delivered to the Gulf by these catchments. Following these analyses, we used modelled river plumes to identify marine areas likely influenced by land-based pollutants. Finally, we prioritised areas for catchment management based on objectives for conservation of terrestrial biodiversity and objectives for water quality that recognised links between pollutant sources and affected marine areas. Our objectives for coastal-marine water quality were to reduce sediment and nutrient discharges from anthropic areas, and minimise future increases in coastal sedimentation and eutrophication. Our objectives for protection of terrestrial biodiversity covered species of vertebrates. We used Marxan, a conservation planning tool, to prioritise interventions and explore spatial differences in priorities for both objectives. Notable differences in the distributions of land values for terrestrial biodiversity and coastal-marine water quality indicated the likely need for trade-offs between catchment management objectives. However, there were priority areas that contributed to both sets of objectives. Our

  2. Spatial relationships in a dendritic network: the herpetofaunal metacommunity of the Mattole River catchment of northwest California.

    Science.gov (United States)

    Hartwell Welsh; Garth Hodgson

    2010-01-01

    We investigated the aquatic and riparian herpetofauna in a 789 km² river catchment in northwest California to examine competing theories of biotic community structuring in catchment stream networks. Research in fluvial geomorphology has resulted in multi-scale models of dynamic processes that cyclically create, maintain, and destroy environments in stream...

  3. Physical and human influences on fluvial water quality in the Tagus river catchment, Portugal

    Science.gov (United States)

    Nunes, A.

    2009-04-01

    Rivers are important resources of drinkable water, ecosystems with a high biologic potency and places of entertainment. Water quality at the catchment scale depends on climate, geology, geomorphology, soils and mainly of land use and land cover. Different activities such as agriculture, livestock, industrial and urban drains have promoted the deterioration of the fluvial water quality. The announced climate changes, the increase of food requirements, as well as the urban concentration of people pose new challenges for the assessment and sustainable management of water quality on the catchment scale. At present about 2/3 of portuguese population live near coast, in urban centers. Since the last three decades, the largest part of the marginal agricultural land has been abandoned whilst the most productive soils have experienced an intensification on its productivity. The Tagus river catchment, with an area of 24.850 km2 only in the Portuguese territory, shows very important contrasts in climate, geology, geomorphology, land use and population density. The main objectives of this work are to evaluate and compare the surface water quality in different sub catchments of Tagus river and to contribute to a better understanding of how physical and human factors (such as geology, precipitation, temperature, runoff, land use and land cover and population density) interfere in their spatial-temporal variability. In order to achieve this issue, twenty sub catchments were selected. The chosen catchments show different locations and areas, and a quite long data series of physical, chemical and biology properties of water, such as nitrates, phosphates, dissolved oxygen, total coliforms, etc. Making use of Geographic Information System (GIS) tools, a database was created for each sub-catchment containing all the physical and human characteristics. Afterwards, statistical analysis was carried out by using SPSS programme (11.0 for Windows. One-way analysis of variance and the Tukey

  4. River recharge sources and the partitioning of catchment evapotranspiration fluxes as revealed by stable isotope signals in a typical high-elevation arid catchment

    Science.gov (United States)

    Guo, Xiaoyu; Tian, Lide; Wang, Lei; Yu, Wusheng; Qu, Dongmei

    2017-06-01

    Catchment-scale hydrological cycles are expected to suffer more extremes under a background of climate change. Quantifying hydrological changes in high and remote areas is practically challenging. However, stable isotopes in river water can be seen to vary, dependent upon the combined influence exerted by recharge sources and local climatic conditions; the study of river water stable isotopes can therefore provide a meaningful method for delineating catchment-scale hydrological studies. In this study, we present high-resolution time series of river δ18O and d-excess values; additionally, we identify the seasonal dynamics of river recharge sources and major components of the catchment-scale water balance, together with precipitation and groundwater isotopes, and concurrent meteorological data recorded in Magazangbu catchment on the northwestern Tibetan Plateau (TP). Using isotopic analysis, and within a proportional framework, we partitioned the isotopic fractionation (E1) or non-fractionation (E2) from soil evaporation fluxes (Esoil) apparent in different processes, using NDVI (Normal Differential Vegetation Index) data collected by MODIS satellites to calculate the vegetation fractional coverage (VFC), and Global Land Data Assimilation System (GLDAS) records to determine evapotranspiration data (ET). Finally, the contributions made by each ET component (Esoil and plant transpiration) to total catchment ET were computed for the high and remote northwestern TP. Our results show that: (1) river δ18O values were high in summer and low in winter, while d-excess values displayed a contrary seasonal cycle; (2) for the monsoon period, precipitation contributed 60.6% to Magazangbu catchment runoff. Deeper groundwater was the main water source for the winter low base flow, and shallow groundwater or high elevation snowmelt was the principal component of the spring thaw and autumn freezing periods; and (3) a substantial proportion of Esoil (96.4% annually; 92.2% during

  5. A participatory approach for Integrated River Basin Management in the Elbe catchment

    Science.gov (United States)

    Nunneri, C.; Hofmann, J.

    2005-02-01

    This paper presents a qualitative analysis of a series of in-depth interviews with governmental and non-governmental institutions (NGOs). Within the EUROCAT 1 project this methodology of participatory approach, aiming to scope the present perceptions about environmental issues and possible strategies for environmental improvement, is applied to the study of the Elbe catchment for the first time. In this frame, an Advisory Board (AB) was created, with the aim of giving insights into conflicting interests in the river catchment and guidelines for river basin management. Focus of the Elbe case study is the issue of nutrient enrichment (from the catchment) and the induced eutrophication of the coastal waters (the German Bight). Specifically, regarding this topic, the possible reduction of eutrophication in the German Bight by a (policy driven) decrease in nutrient inputs from the catchment area is analysed. Different measures for reducing the input of nutrients from the catchment, and ultimately preventing eutrophication of the coastal waters are considered. In this context, the members of the AB were asked about the efficiency and feasibility of different measures and the criteria for choosing 'better' management solutions among the possible ones. Although there is a general agreement about the necessity of reducing nutrient emissions, some members of the AB perceive other environmental issues (e.g. altered morphodynamics) as more relevant than nutrient enrichment. Voluntary cooperation, eco-efficiency and 'trans-sectoral' communication are the key concepts mentioned as being indispensable for integrated management. The (public) acceptance of measures for nutrient reduction have to find its way through compromises and social equity, allowing for win-win solutions among different groups of interests and balanced spatial division of costs and benefits. EUROpean CATchments, Project N° EVK1-CT-2000-00044 ( http://www.iia-cnr.unical.it/EUROCAT/project.htm).

  6. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: Surficial Geology

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This tabular data set represents the area of surficial geology types in square meters compiled for every MRB_E2RF1 catchment of selected Major River Basins (MRBs,...

  7. Using high-resolution phosphorus data to investigate mitigation measures in headwater river catchments

    Directory of Open Access Journals (Sweden)

    J. M. Campbell

    2014-09-01

    Full Text Available This study reports the use of high resolution water quality monitoring to assess the influence of changes in landuse management on total phosphorus (TP transfers in two 5 km2 agricultural sub-catchments. Specifically, the work investigates the "wicked problem" of agricultural soil P management and subsequent diffuse transfers at high river flows over a five year timescale. The work also investigates the phenomenon of low flow P pollution from septic tank systems (STS and mitigation efforts – here termed the "filthy issue" of rural catchment management. Results showed an inconsistent response to soil P management over five years with one catchment showing a convergence to optimum P concentrations and the other an overall increase. Both catchments indicated an overall increase in P concentration in defined high flow ranges. Low flow P concentration showed little change or higher P concentrations in defined low flow ranges despite replacement of defective systems and this is possibly due to a number of confounding reasons including increased housing densities due to new-builds. The work indicates fractured responses to catchment management advice and mitigation and that the short to medium term may be an insufficient time to expect the full implementation of policies (here defined as convergence to optimum soil P concentration and mitigation of STS and also to gauge their effectiveness.

  8. Using high-resolution phosphorus data to investigate mitigation measures in headwater river catchments

    Science.gov (United States)

    Campbell, J. M.; Jordan, P.; Arnscheidt, J.

    2014-09-01

    This study reports the use of high resolution water quality monitoring to assess the influence of changes in landuse management on total phosphorus (TP) transfers in two 5 km2 agricultural sub-catchments. Specifically, the work investigates the "wicked problem" of agricultural soil P management and subsequent diffuse transfers at high river flows over a five year timescale. The work also investigates the phenomenon of low flow P pollution from septic tank systems (STS) and mitigation efforts - here termed the "filthy issue" of rural catchment management. Results showed an inconsistent response to soil P management over five years with one catchment showing a convergence to optimum P concentrations and the other an overall increase. Both catchments indicated an overall increase in P concentration in defined high flow ranges. Low flow P concentration showed little change or higher P concentrations in defined low flow ranges despite replacement of defective systems and this is possibly due to a number of confounding reasons including increased housing densities due to new-builds. The work indicates fractured responses to catchment management advice and mitigation and that the short to medium term may be an insufficient time to expect the full implementation of policies (here defined as convergence to optimum soil P concentration and mitigation of STS) and also to gauge their effectiveness.

  9. A Method for Applying Fluvial Geomorphology in Support of Catchment-Scale River Restoration Planning

    Science.gov (United States)

    Sear, D.; Newson, M.; Hill, C.; Branson, J.; Old, J.

    2005-12-01

    Fluvial geomorphology is increasingly used by those responsible for conserving river ecosystems; survey techniques are used to derive conceptual models of the processes and forms that characterise particular systems and locations, with a view to making statements of `condition' or `status' and providing fundamental strategies for rehabilitation/restoration. However, there are important scale-related problems in developing catchments scale restoration plans that inevitably are implemented on a reach- by-reach basis. This paper reports on a watershed scale methodology for setting geomorphological and physical habitat reference conditions based on a science-based conceptual model of cachment:channel function. Using a case study from the River Nar, a gravel-bed groundwater dominated river in the UK with important conservation status, the paper describes the sequences of the methodology; from analysis of available evidence, process of field data capture and development of a conceptual model of catchment-wide fluvial dynamics. Reference conditions were derived from the conceptual model and gathered from the literature for the two main river types found on the river Nar, and compared with the current situation in 76 sub-reaches from source to mouth. Multi-Criteria Analysis (MCA) was used to score the extent of channel departures from `natural' and to suggest the basis for a progressive restoration strategy for the whole river system. MCA is shown to be a flexible method for setting and communicating decisions that are amenable to stakeholder and public consultation.

  10. Occurrence of metolachlor and trifluralin losses in the Save river agricultural catchment during floods.

    Science.gov (United States)

    Boithias, Laurie; Sauvage, Sabine; Taghavi, Lobat; Merlina, Georges; Probst, Jean-Luc; Pérez, José Miguel Sánchez

    2011-11-30

    Rising pesticide levels in streams draining intensively managed agricultural land have a detrimental effect on aquatic ecosystems and render water unfit for human consumption. The Soil and Water Assessment Tool (SWAT) was applied to simulate daily pesticide transfer at the outlet from an agriculturally intensive catchment of 1110 km(2) (Save river, south-western France). SWAT reliably simulated both dissolved and sorbed metolachlor and trifluralin loads and concentrations at the catchment outlet from 1998 to 2009. On average, 17 kg of metolachlor and 1 kg of trifluralin were exported at outlet each year, with annual rainfall variations considered. Surface runoff was identified as the preferred pathway for pesticide transfer, related to the good correlation between suspended sediment exportation and pesticide, in both soluble and sorbed phases. Pesticide exportation rates at catchment outlet were less than 0.1% of the applied amount. At outlet, SWAT hindcasted that (i) 61% of metolachlor and 52% of trifluralin were exported during high flows and (ii) metolachlor and trifluralin concentrations exceeded European drinking water standards of 0.1 μg L(-1) for individual pesticides during 149 (3.6%) and 17 (0.4%) days of the 1998-2009 period respectively. SWAT was shown to be a promising tool for assessing large catchment river network pesticide contamination in the event of floods but further useful developments of pesticide transfers and partition coefficient processes would need to be investigated.

  11. The relative influence of catchment, riparian corridor, and reach-scale anthropogenic pressures on fish and macroinvertebrate assemblages in French rivers

    NARCIS (Netherlands)

    Marzin, A.; Verdonschot, P.F.M.; Pont, D.

    2013-01-01

    This study compares the relative influences of physiography and anthropogenic pressures on river biota at catchment, riparian corridor, and reach scales. Environmental data, catchment and riparian corridor land use, anthropogenic modifications and biological data were compiled for 301 French sites

  12. Late Miocene Hydrological Change in the Indus River Catchment

    Science.gov (United States)

    Liddy, H.; Feakins, S. J.; Clift, P. D.; Tauxe, L.; Kulhanek, D. K.; Scardia, G.; Warny, S.; Bendle, J. A.; Galy, V.; Zhou, P.; Science Party, E.

    2016-12-01

    The cause of the late Miocene proliferation of C4 grasslands in the Indo-Asian region is a long-standing question. Terrestrial records suggest that changes in regional hydrological processes drove changes in C4 plant expansion. However, part of the ambiguity lies in the geographic extent of existing proxy records as well as the particular aspect of hydrology that they record. Therefore a better understanding of the hydrological influence on C4 expansion requires the direct reconstruction of precipitation changes. Turbidite sedimentation in the Indus Fan captures the history of the terrestrial environment and erosional change in the Indus catchment. With Indus Fan sediments from IODP Expedition 355, we resolve hydrological change in this region using geochemical (both inorganic and organic) and pollen approaches. Provenance analysis using Nd isotopes verifies that changes in hydrology occurred independently of changes in sediment sourcing prior to 6 Ma. Therefore, we infer that shifts in plant wax hydrogen isotopes (up to 60‰) after 8.3 Ma and 7 Ma reflect changes in the dominant moisture source region (the Indian Ocean versus the Mediterranean and other inland seas). Vegetation also tracks hydrology: pollen and plant wax carbon isotopes (including n-alkanoic acid C28-C34 and n-alkane C27-C35) suggest that C4 grassland was present in the Indus floodplains prior 8.3 Ma and expanded after 7 Ma. The early 10 Ma C4 expansion is observed in other regions surrounding the Arabian Sea at this time and the later C4 expansion ( 7-6 Ma) occurs coeval records from the Siwalik Formation of the Himalayan foreland and Bengal Fan sediments. New evidence from plant wax hydrogen isotopes suggests that changing precipitation triggered ecological changes in the Indus catchment during the late Miocene.

  13. Spatiotemporal variability of oxygen isotope compositions in three contrasting glacier river catchments in Greenland

    Directory of Open Access Journals (Sweden)

    J. C. Yde

    2015-06-01

    Full Text Available Analysis of stable oxygen isotope (δ18O characteristics is a useful tool to investigate water provenance in glacier river systems. In order to attain knowledge on the diversity of spatio-temporal δ18O variations in glacier rivers, we have examined three glacierized catchments in Greenland with different areas, glacier hydrology and thermal regimes. At Mittivakkat Gletscher River, a small river draining a local temperate glacier in southeast Greenland, diurnal oscillations in δ18O occur with a three-hour time lag to the diurnal oscillations in runoff. Throughout the peak flow season the δ18O composition is controlled by the proportion between snowmelt and ice melt with episodic inputs of rainwater and occasional storage and release of a specific water component due to changes in the subglacial drainage system. At Kuannersuit Glacier River on the island Qeqertarsuaq, the δ18O characteristics were examined after the major 1995–1998 glacier surge event. Despite large variations in the δ18O values of glacier ice on the newly formed glacier tongue, there were no diurnal oscillations in the bulk meltwater emanating from the glacier in the post-surge years 2000–2001. In 2002 there were indications of diurnal oscillations, and in 2003 there were large diurnal fluctuations in δ18O. At Watson River, a large catchment at the western margin of the Greenland Ice Sheet, the spatial distribution of δ18O in the river system was applied to fingerprint the relative runoff contributions from sub-catchments. Spot sampling indicates that during the early melt season most of the river water (64–73 % derived from the Qinnguata Kuussua tributary, whereas the water flow on 23 July 2009 was dominated by bulk meltwater from the Akuliarusiarsuup Kuua tributary (where 7 and 67 % originated from the Russell Glacier and Leverett Glacier sub-catchments, respectively. A comparison of the δ18O compositions from glacial river water in Greenland shows distinct

  14. Spatiotemporal variability of oxygen isotope compositions in three contrasting glacier river catchments in Greenland

    Science.gov (United States)

    Yde, J. C.; Tvis Knudsen, N.; Steffensen, J. P.; Carrivick, J. L.; Hasholt, B.; Ingeman-Nielsen, T.; Kronborg, C.; Larsen, N. K.; Mernild, S. H.; Oerter, H.; Roberts, D. H.; Russell, A. J.

    2015-06-01

    Analysis of stable oxygen isotope (δ18O) characteristics is a useful tool to investigate water provenance in glacier river systems. In order to attain knowledge on the diversity of spatio-temporal δ18O variations in glacier rivers, we have examined three glacierized catchments in Greenland with different areas, glacier hydrology and thermal regimes. At Mittivakkat Gletscher River, a small river draining a local temperate glacier in southeast Greenland, diurnal oscillations in δ18O occur with a three-hour time lag to the diurnal oscillations in runoff. Throughout the peak flow season the δ18O composition is controlled by the proportion between snowmelt and ice melt with episodic inputs of rainwater and occasional storage and release of a specific water component due to changes in the subglacial drainage system. At Kuannersuit Glacier River on the island Qeqertarsuaq, the δ18O characteristics were examined after the major 1995-1998 glacier surge event. Despite large variations in the δ18O values of glacier ice on the newly formed glacier tongue, there were no diurnal oscillations in the bulk meltwater emanating from the glacier in the post-surge years 2000-2001. In 2002 there were indications of diurnal oscillations, and in 2003 there were large diurnal fluctuations in δ18O. At Watson River, a large catchment at the western margin of the Greenland Ice Sheet, the spatial distribution of δ18O in the river system was applied to fingerprint the relative runoff contributions from sub-catchments. Spot sampling indicates that during the early melt season most of the river water (64-73 %) derived from the Qinnguata Kuussua tributary, whereas the water flow on 23 July 2009 was dominated by bulk meltwater from the Akuliarusiarsuup Kuua tributary (where 7 and 67 % originated from the Russell Glacier and Leverett Glacier sub-catchments, respectively). A comparison of the δ18O compositions from glacial river water in Greenland shows distinct differences between water

  15. Rivers as borders, uniting or dividing? The effect of topography and implications for catchment management.

    Science.gov (United States)

    Smedley, D A; Rowntree, K M

    2012-01-01

    South Africa's water resources are unequally distributed over space and time and an already stressed water resource situation will only be exacerbated by climate change if current predictions are correct. The potential for conflict over increasingly strained water resources in South Africa is thus very real. In order to deal with these complex problems, national legislation is demanding that water resource management be decentralized to the local level where active participation can take place in an integrated manner in accordance with the principles of Integrated Water Resource Management (IWRM). However, administrative and political boundaries rarely match those of catchments as, throughout South Africa, rivers have been employed extensively to delineate administrative and political boundaries at a number of spatial scales. The aim of this research is to determine if rivers act as dividing or uniting features in a socio-political landscape and whether topography will influence their role in this context. The Orange-Senqu River is used as a case study. This paper goes on to consider the implications of this for catchment management in South Africa. No study known to the authors has explored the effect of the river itself, and its topographic setting, on the drivers that foster either conflict or cooperation, and allow for participatory management. This study presents evidence that the topography of a catchment has the ability to aggravate or reduce the impact of the variables considered by water managers and thereby influence the role of a river as a dividing or uniting feature. South Africa's proposed form of decentralized water management will have to contend with the effects of different topographies on the way in which rivers are perceived and utilized.

  16. The effects of flooding on dioxin and PCB levels in food produced on industrial river catchments.

    Science.gov (United States)

    Lake, Iain R; Foxall, Christopher D; Fernandes, Alwyn; Lewis, Mervyn; Rose, Martin; White, Oliver; Lovett, Andrew A; White, Shaun; Dowding, Alan; Mortimer, David

    2015-04-01

    This research examined the effect of regular flooding upon PCDD/F and PCB levels in milk, beef and lamb, produced on the floodplains of industrial river catchments. Our unique dataset included more than 200 samples analysed for PCDD/Fs and PCBs over two data collection phases (1998-1999 & 2008-2010) from working farms. A robust paired study design was adopted with samples taken from flood-prone farms and nearby control farms not subject to flooding. On industrial river catchments regular flooding is associated with higher PCDD/F and PCB levels in soils and grass. This contamination may be transferred to food but the impact varied by food type. These contrasts may be due to physiological differences between animals, the ages at which they are sent to market and differences in animal husbandry. To minimise the risks of producing food on flood-prone land in industrial river catchments, as well as on any land with elevated PCDD/F and PCB levels, this research suggests a number of options. The choice of livestock may be important and as an example in our study beef cattle accumulated PCDD/Fs to a higher degree than sheep. Land management may also play a role and could include minimising the time that livestock spend on such land or feeding commercial feed, low in PCDD/Fs and PCBs, where appropriate.

  17. A spatially intensive approach to water quality monitoring in the Rous River catchment, NSW, Australia

    Energy Technology Data Exchange (ETDEWEB)

    Eyre, B.D.; Pepperell, P. [Southern Cross Univ., Lismore, New South Wales (Australia). Centre for Coastal Management

    1999-06-01

    The Rous River catchment northern NSW, Australia was used as a case study to evaluate a spatially intensive approach to water quality monitoring, which involved the collection of water quality data from a large number of sample sites over a short period of time. Despite a few potential limitations, the spatially intensive water quality monitoring methodology should allow environmental managers to rapidly and cost-effectively (in the long term) identify point and non-point source impacts on water quality. Three point sources, the Murwillumbah Sewage Treatment Plant, a dairy shed and horse stables had the largest impact on water quality in the Rous River catchment during baseflow conditions. The poorest water quality in the Rous River catchment, due to non-point source inputs, was associated with cane land, which had evaluated total nitrogen, total particulate nitrogen, and dissolved organic nitrogen concentrations and temperatures that were significantly greater (Kruskai-Wallis, {proportional_to} {gt}0.05) than other land uses.

  18. USLE-Based Assessment of Soil Erosion by Water in the Nyabarongo River Catchment, Rwanda.

    Science.gov (United States)

    Karamage, Fidele; Zhang, Chi; Kayiranga, Alphonse; Shao, Hua; Fang, Xia; Ndayisaba, Felix; Nahayo, Lamek; Mupenzi, Christophe; Tian, Guangjin

    2016-08-20

    Soil erosion has become a serious problem in recent decades due to unhalted trends of unsustainable land use practices. Assessment of soil erosion is a prominent tool in planning and conservation of soil and water resource ecosystems. The Universal Soil Loss Equation (USLE) was applied to Nyabarongo River Catchment that drains about 8413.75 km² (33%) of the total Rwanda coverage and a small part of the Southern Uganda (about 64.50 km²) using Geographic Information Systems (GIS) and Remote Sensing technologies. The estimated total annual actual soil loss was approximately estimated at 409 million tons with a mean erosion rate of 490 t·ha(-1)·y(-1) (i.e., 32.67 mm·y(-1)). The cropland that occupied 74.85% of the total catchment presented a mean erosion rate of 618 t·ha(-1)·y(-1) (i.e., 41.20 mm·y(-1)) and was responsible for 95.8% of total annual soil loss. Emergency soil erosion control is required with a priority accorded to cropland area of 173,244 ha, which is extremely exposed to actual soil erosion rate of 2222 t·ha(-1)·y(-1) (i.e., 148.13 mm·y(-1)) and contributed to 96.2% of the total extreme soil loss in the catchment. According to this study, terracing cultivation method could reduce the current erosion rate in cropland areas by about 78%. Therefore, the present study suggests the catchment management by constructing check dams, terracing, agroforestry and reforestation of highly exposed areas as suitable measures for erosion and water pollution control within the Nyabarongo River Catchment and in other regions facing the same problems.

  19. The IRMA concept applied to River Cetina and Split catchment

    Directory of Open Access Journals (Sweden)

    Marco GONELLA

    2006-12-01

    Full Text Available Integrated coastal zone and river basin management systems are being developed to meet important societal needs such as the sustainable development of coastal areas, the exploitation of their resources and the protection of the coastal environment. The sustainable development of coastal areas depends on the quality of the marine environment. In this context, the ADRICOSM project (ADRIatic sea integrated COastal areaS and river basin Management system pilot project has developed an assessment/forecasting system that enables policy decisions to be taken in a modern and efficient way. The integrated approach imposed by the EC’s Water Framework Directive has been validated in a pilot area located in Croatia that includes all the main components responsible for pollution generation and transportation: urban watershed, river basin and coastal area. An integrated model has been developed combining different tools to simulate the hydraulic and waterquality performance of the overall system. This model has then been used to forecast the benefits derived from priority works focused on reducing land-based pollution.

  20. Ecological quality assessment of rivers and integrated catchment management in England and Wales

    Directory of Open Access Journals (Sweden)

    Paul LOGAN

    2001-09-01

    Full Text Available This paper deals with the ecological assessment of river quality and its relationship to integrated catchment management. The concept of catchment or river basin management has been a basic management tool in England and Wales since 1990; it is now being enshrined in the Water Framework Directive. Historically the statutory and operational drivers in the UK have lead to the development of distinctly different approaches to the management of water quality, water resources (quantity and physical river structure. More recently a proactive approach to the sustainable use of water promulgated in the Local Environment Agency Plans has also dealt with the three management aspects in some isolation although greater effort has been made to present the issues in an integrated manner. The Water Framework Directive calls for further integration in river basin plans and associated programmes of measures. In the paper the three approaches are described and considered in light of the requirements of the Water Framework Directive. Water Quality classification and objective setting has been based on information from the survey of benthic macro-invertebrates. The Biological Monitoring Working Party Score and the predictive software River Invertebrate Prediction and Classification System (RIVPACS have been used to set site-specific targets for management purposes. RIVPACS includes a reference database of minimally impacted sites for comparison with the observed data. This approach is in line with the requirements of the directive. Physical river structure work has been based on monitoring of in-river and river corridor characteristics. The River Habitat System (RHS has also developed a reference database but is less well developed in terms of its predictive ability. The use of ecological information in Water Resource management has taken a different approach based on the concept of differential ecological sensitivity to the hydrological regime within the river. In

  1. The inflow of polonium (210)Po from Vistula river catchments area.

    Science.gov (United States)

    Skwarzec, Bogdan; Jahnz, Anna

    2007-12-01

    The activities of polonium (210)Po in Vistula unfiltered water samples, collected from November 2002 to November 2003, were measured using the alpha spectrometry. In winter, the highest concentration of (210)Po was in Vistula river water from Torun (2.72 +/- 0.04 Bq x m(-3)) and from the Wieprz river (5.46 +/- 0.07 Bq x m(-3) [Bequerel per cubic metre]), and the lowest was in water from Nida river (0.59 +/- 0.02 Bq x m(-3)). During spring, the highest concentration of (210)Po was observed in Vistula water collected in Deblin (5.98 +/- 0.03 Bq x m(-3)) and the lowest in water from the Narew river (1.20 +/- 0.12 Bq x m(-3)). In summer, the highest concentration of (210)Po was in Nogat river water collected in Malbork (3.18 +/- 0.04 Bq x m(-3)) and the Bzura river (5.30 +/- 0.02 Bq x m(-3)), the lowest in Wieprz river (0.49 +/- 0.09 Bq x m(-3)) and Vistula river water from Kraków (1.44 +/- 0.05 Bq x m(-3)). In autumn, the highest (210)Po concentration was in Bzura river (8.93 +/- 0.03 Bq x m(-3)), the lowest in Vistula water from Grudziadz (1.51 +/- 0.04 Bq x m(-3)), and Toruń (1.89 +/- 0.05 Bq x m(-3)). The highest quantity of (210)Po was transported from Vistula catchments area to the Baltic Sea in spring and the lowest in summer. Annually, the southern Baltic Sea is enriched by about 73.7 GBq (210)Po (with Leniwka and Nogat rivers), with 71.6 GBq going to Gdańsk Bay and 2.1 GBq to Vistula Lagoon. The highest surface (210)Po runoff was observed in spring (to 1370 kBq x km(-2) x quarter(-1) for Dunajec catchment's area), the lowest in summer (for Nida catchment's area to 100 kBq x km(-2) x quarter(-1)).

  2. Very long hillslope transport timescales determined from uranium-series isotopes in river sediments from a large, tectonically stable catchment

    Science.gov (United States)

    Suresh, P. O.; Dosseto, A.; Hesse, P. P.; Handley, H. K.

    2014-10-01

    The uranium-series isotopic compositions of soils and sediments evolve in response to time and weathering conditions. Therefore, these isotopes can be used to constrain the timescales of river sediment transport. Catchment evolution depends on the sediment dynamic timescales, on which erosion imparts a major control. Erosion rates in tectonically stable catchments are expected to be lower than those in tectonically active catchments, implying longer sediment residence times in tectonically stable catchments. Mineralogical, elemental and isotopic data are presented for modern channel sediments, alluvial and colluvial deposits from the Murrumbidgee River, a large catchment in the passive margin highlands of south-eastern Australia and three of its tributaries from the headwaters to the alluvial plain. Low variability in Si-based Weathering Index indicates that there is little chemical weathering occurring in the Murrumbidgee River during sediment transport. However, quartz content increases and plagioclase content decreases downstream, indicating progressive mineralogical sorting and/or physical comminution with increasing transport distance. U-series isotopic ratios in the Murrumbidgee River trunk stream sediments show no systematic downstream variation. The weathering ages of sediments within the catchment were determined using a loss-gain model of U-series isotopes. Modern sediments from a headwater tributary, the Bredbo River at Frogs Hollow, have a weathering age of 76 ± 30 kyr but all other modern channel sediments from the length of the Murrumbidgee River and its main tributaries have weathering ages ∼400 ± 180 kyr. The two headwater colluvial deposits have weathering ages of 57 ± 13 and 47 ± 11 kyr, respectively. All the alluvial deposits have weathering ages similar to those of modern sediments. No downstream trend in weathering age is observed. Together with the soil residence time of up to 30 kyr for ridge-top soils at Frogs Hollow in the upper

  3. Variability of rainfall over Lake Kariba catchment area in the Zambezi river basin, Zimbabwe

    Science.gov (United States)

    Muchuru, Shepherd; Botai, Joel O.; Botai, Christina M.; Landman, Willem A.; Adeola, Abiodun M.

    2016-04-01

    In this study, average monthly and annual rainfall totals recorded for the period 1970 to 2010 from a network of 13 stations across the Lake Kariba catchment area of the Zambezi river basin were analyzed in order to characterize the spatial-temporal variability of rainfall across the catchment area. In the analysis, the data were subjected to intervention and homogeneity analysis using the Cumulative Summation (CUSUM) technique and step change analysis using rank-sum test. Furthermore, rainfall variability was characterized by trend analysis using the non-parametric Mann-Kendall statistic. Additionally, the rainfall series were decomposed and the spectral characteristics derived using Cross Wavelet Transform (CWT) and Wavelet Coherence (WC) analysis. The advantage of using the wavelet-based parameters is that they vary in time and can therefore be used to quantitatively detect time-scale-dependent correlations and phase shifts between rainfall time series at various localized time-frequency scales. The annual and seasonal rainfall series were homogeneous and demonstrated no apparent significant shifts. According to the inhomogeneity classification, the rainfall series recorded across the Lake Kariba catchment area belonged to category A (useful) and B (doubtful), i.e., there were zero to one and two absolute tests rejecting the null hypothesis (at 5 % significance level), respectively. Lastly, the long-term variability of the rainfall series across the Lake Kariba catchment area exhibited non-significant positive and negative trends with coherent oscillatory modes that are constantly locked in phase in the Morlet wavelet space.

  4. Quantifying diffuse and point inputs of perfluoroalkyl acids in a nonindustrial river catchment.

    Science.gov (United States)

    Müller, Claudia E; Spiess, Nora; Gerecke, Andreas C; Scheringer, Martin; Hungerbühler, Konrad

    2011-12-01

    Recently, the role of diffuse inputs of perfluoroalkyl acids (PFAAs) into surface waters has been investigated. It has been observed that river loads increased during rain and that street runoff contained considerable loads of PFAAs. This study aims at quantifying these diffuse inputs and identifying the initial sources in a small nonindustrial river catchment. The river was sampled in three distinct subcatchments (rural, urban, and wastewater treatment plant) at high temporal resolution during two rain events and samples were analyzed for perfluorocarboxylates and perfluorosulfonates. Additionally, rain, stormwater runoff, wastewater effluent, and drinking water were sampled. PFAA concentrations in river water were all low (e.g., water discharge data were integrated into a mass balance assessment that shows that 30-60% of PFAA loads can be attributed to diffuse inputs. Rain contributed 10-50% of the overall loads, mobilization of dry deposition and outdoor release of PFAA from products with 20-60%. We estimated that within a year 2.5-5 g of PFOA originating from rain and surface runoff are emitted into this small catchment (6 km(2), 12,500 persons).

  5. Development of integrated catchment and water quality model for urban rivers

    Institute of Scientific and Technical Information of China (English)

    薛重华; 尹海龙; 解铭

    2015-01-01

    This paper presents the development of an urban river water quality model which considers the physical-biochemical processes within rivers and the incorporated urban catchment rainfall-runoff process developed with the time–area method. Unlike other models that simulate the hydrological and receiving water quality processes in the rural areas of the watershed scale, the model developed here is typically efficient for simulating the water quality response to nonpoint loadings from urban drainage systems, where the hydrological process is disturbed by artificially pumped discharge in wet-weather periods. This model is employed to assess the river water quality restoration in Nanfei River in Hefei City, China, where the model is calibrated against the measured data (i.e., the COD, the BOD5, the NH3-N, and the DO) in 2010, and the model parameters are suggested. It is shown that the nonpoint pollutants from the urban catchments contribute 34%-47% of the total pollutant inputs (i.e., the COD, the BOD5, and the NH3-N), despite their low flow component of 13.4%. Apart from the improvement of the wastewater treatment plant effluent (i.e., Grade IV of the Surface Water Quality Standard), a nonpoint loading reduction of 27.2%, 25.1%, and 35.3% of the COD, the BOD5, and the NH3-N are anticipated to meet the designated surface water quality standards of Grade V.

  6. THE CHANGES IN WATER RELATIONS IN THE CATCHMENT BASIN OF RIVER TYSMIENICA

    Directory of Open Access Journals (Sweden)

    Antoni Grzywna

    2014-10-01

    Full Text Available The paper presents the history of water conditions in the catchment area of the river Tyśmienica. On the basis of topographic maps in scale 1 : 100 000 1839 to 2009, and drainage projects presents the changes of the water network. In the middle 19th century, the river took the start from the lake Krzczeń, and major reclamation works were performed at the turn of the century. In the seventeenth century, built the largest pond Siemień. The development of the joint occurred after World One War because the existence of joints protect assets before breaking up. The biggest changes in water relations occurred in the years 1954 to 1961, when it built Wieprz – Krzna Canal in the valley created several objects drainage area of about 15 000 ha. In the 60’s the water channel beginning the Tyśmienica led passing to the east of Lake Krzczeń and Rogóźno. As a result of hydrotechnical works, the length of the river increased from 62 to 74,5 km, and its beginning was shifted to lake Rogóźno. The surface area of the catchment basin of the river at the beginning of the 18th century was 2000 km2, while at present, at the beginning of the 21st century it is 2750 km2.

  7. Excess erosion and deposition in the catchments of Kamenichka and Radanjska river, Republic of Macedonia

    Directory of Open Access Journals (Sweden)

    Milevski Ivica

    2009-01-01

    Full Text Available One of the greatest environmental problems in the Republic of Macedonia is accelerated soil erosion caused by high human impact during last centuries on to the susceptible landscape. Natural factors itself are very suitable for development of such erosion: from mostly erodible rocks and soils on the mountainous slopes around the depressions, to the generally continental, semi-arid climate and slight vegetation cover. Because of that, there are sites with severe erosion and deposition like those in the catchments of Kamenichka River and Radanjska River, two torrential tributaries of Bregalnica. In these catchments there are varieties of erosion-related landforms: rills, gullies, badlands, landslides, as well as valley-type alluvial fans and huge alluvial plains. Such devastating accelerated erosion and deposition largely transformed original landscape, and represent significant environmental, social, and economic problem in local areas. Because of that, some measures of protection and conservation were taken from 1950-ties in both catchments. But it is obvious that the final effect of these measures is far of enough, so new efforts must be implemented to revitalizing these abandoned lands.

  8. Demonstration Restoration Measures in Tributaries of the Vindel River Catchment

    Directory of Open Access Journals (Sweden)

    Johanna Gardeström

    2013-09-01

    Full Text Available Some ecological restoration projects include elements of trial and error where new measures are repeatedly tried, evaluated, and modified until satisfactory results are achieved. Thereafter, the resulting methods may be applied on larger scales. A difficult step is judging whether developed "best-practice" methods have become reasonably ecologically functional or whether further experimentation "demonstration" methods can lead to yet better results. Here, we use a stream restoration project as a case study for evaluating methods and abiotic effects and outlining stakeholder support for demonstration restoration measures, rather than only using best-practice methods. Our work was located in the Vindel River system, a free-flowing river that is part of the Natura 2000 network. The river was exploited for timber floating from 1850-1976, and rapids in the main channel and tributaries below timberline were channelized to increase timber transport capacity. Several side channels in multi-channeled rapids were blocked and the flow was concentrated to a single channel from which boulders and large wood were removed. Hence, previously heterogeneous environments were replaced by more homogeneous systems with limited habitat for riverine species. The restoration project strives to alleviate the effects of fragmentation and channelization in affected rapids by returning coarse sediment from channel margins to the main channel. However, only smaller, angular sediment is available given blasting of large boulders, and large (old-growth wood is largely absent; therefore, original levels of large boulders and large wood in channels cannot be achieved with standard restoration practices. In 10 demonstration sites, we compensated for this by adding large boulders and large wood (i.e., entire trees from adjacent upland areas to previously best-practice restored reaches and compared their hydraulic characteristics with 10 other best-practice sites. The

  9. Isotopic investigation of the discharge driven nitrogen dynamics in a mesoscale river catchment

    Science.gov (United States)

    Mueller, Christin; Zink, Matthias; Krieg, Ronald; Rode, Michael; Merz, Ralf; Knöller, Kay

    2016-04-01

    Nitrate in surface and groundwater has increased in the last decades due to landuse change, the application of different fertilizer for agricultural landuse and industrial dust in the atmospheric deposition. Increasing nitrate concentrations have a major impact on eutrophication, especially for coastal ecosystems. Therefore it is important to quantify potential nitrate sources and determine nitrate process dynamics with its drivers. The Bode River catchment (total size of 3200 m2) in the Harz Mountains in Germany was intensively investigated by a monitoring approach with 133 sampling points representing the same number of sub-catchments for a period of two years. The area is characterized by a strong anthropogenic gradient, with forest conservation areas in the mountain region, grassland, and intensively mixed farming in the lowlands. Consecutive discharge simulations by a mesoscale hydrological model (mhM) allow a quantitative analysis of nitrate fluxes for all observed tributaries. The investigation of nitrate isotopic signatures for characteristic landscape types allows the delineation of dominant NO3- sources: coniferous forests are characterized by recycled nitrified soil nitrogen; grassland is mainly impacted by organic fertilizer (manure) and nitrified soil-N; in agricultural land use areas nitrate predominantly derives from synthetic fertilizer application. Besides source delineation, the relationship between runoff and nitrate dynamics was analyzed for the entire Bode river catchment and, more detailed, for one major tributary with minor artificial reservoirs (Selke River). Thereby, it becomes apparent that nitrate isotopic variations increase with decreasing discharge. This effect might be due to a local, more intense impact of bacterial denitrification under low discharge conditions (higher residence time) in the anoxic soil zone, in the groundwater that discharges into the river and in the hyporheic zone. Generally, δ15N and δ18Oof nitrate decrease

  10. Stable oxygen isotope variability in two contrasting glacier river catchments in Greenland

    DEFF Research Database (Denmark)

    Yde, Jacob C.; Knudsen, Niels T.; Steffensen, Jørgen P.;

    2016-01-01

    subglacial drainage network in the upper part of the glacier. At the Kuannersuit Glacier river on the island Qeqertarsuaq in west Greenland, the δ18O characteristics were examined after the major 1995-1998 glacier surge event. The mean annual δ18O was -19.47±0.55 ‰. Despite large spatial variations in the δ......18O values of glacier ice on the newly formed glacier tongue, there were no diurnal oscillations in the bulk meltwater emanating from the glacier in the post-surge years. This is likely a consequence of a tortuous subglacial drainage system consisting of linked cavities, which formed during the surge......Analysis of stable oxygen isotope (δ18O) characteristics is a useful tool to investigate water provenance in glacier river systems. In order to attain knowledge on the diversity of δ18O variations in Greenlandic rivers, we examined two contrasting glacierised catchments disconnected from...

  11. Uniform Transnational Assessment of the Environmental Indices from the Romanian Catchment Area of the Tisa River

    Directory of Open Access Journals (Sweden)

    SILVIU-FLORIN FONOGEA

    2010-01-01

    Full Text Available The uniform transnational assessment of the environmental indices in the catchment area of the Tisa river aims at rehabilitating, protecting and conserving the environmental systems, as well as creating a commonly strategic demarche concerning a sustainable spatial development, based on integrated intersectorial approaches of environmental issues, viewed in their territorial dimension. The information necessary in underlining the current situation in the Romanian catchment area of the Tisa has been structured according to the following categories of analysed indices: sources of surface waters, resources of drinkable water and water supply resources, the risk of not reaching the environmental objectives, significant sources of water pollution (punctual sources of pollution, diffuse sources of pollution, significant hydromorphic pressure, the quality of water, significant sources of air pollution, soils affected by agricultural and industrial activities, nature protection and waste management.

  12. Mapping SOC in a river catchment by integrating laboratory spectra wavelength with remote sensing spectra

    DEFF Research Database (Denmark)

    Peng, Yi; Xiong, Xiong; Knadel, Maria;

    There is potential to use soil ·-proximal and remote sensing derived spectra concomitantly to develop soil organic carbon (SOC) models. Yet mixing spectral data from different sources and technologies to improve soil models is still in its infancy. The objective of this study was to incorporate...... soil spectral features indicative of SOC from laboratory visible near-infrared reflectance (vis-NlR) spectra and incorporate them with remote sensing (RS) images to improve predictions of top SOC in the Skjem river catchment, Denmark. The secondary objective was to improve prediction results...... by separately calibrating samples from upland and wetland. We hypbthesize that final prediction accuracy is significantly improved by incorporatin1 laboratory vis-NlR images upscaled from point-based spectra to catchment scale and RS data for topsoil SOC spatial modeling....

  13. Estimation of Catchment Transit Time in Fuji River Basin by using an improved Tank model

    Science.gov (United States)

    Wenchao, M.; Yamanaka, T.; Wakiyama, Y.; Wang, P.

    2013-12-01

    As an important parameter that reflects the characteristics of catchments, the catchment transit time (CTT) has been given much more widely attentions especially in recent years. The CTT is defined as the time water spends travelling through a catchment to the stream network [1], and it describes how catchments retain and release water and solutes and thus control geochemical and biogeochemical cycling and contamination persistence [2]. The objectives of the present study are to develop a new approach for estimating CTT without prior information on such TTD functions and to apply it to the Fuji River basin in the Central Japan Alps Region. In this study, an improved Tank model was used to compute mean CTT and TTD functions simultaneously. It involved water fluxes and isotope mass balance. Water storage capacity in the catchment, which strongly affects CTT, is reflected in isotope mass balance more sensitively than in water fluxes. A model calibrated with observed discharge and isotope data is used for virtual age tracer computation to estimate CTT. This model does not only consider the hydrological data and physical process of the research area but also reflects the actual TTD with considering the geological condition, land use and the other catchment-hydrological conditions. For the calibration of the model, we used river discharge record obtained by the Ministry of Land, Infrastructure and Transportation, and are collecting isotope data of precipitation and river waters monthly or semi-weekly. Three sub-catchments (SC1~SC3) in the Fuji River basin was selected to test the model with five layers: the surface layer, upper-soil layer, lower-soil layer, groundwater aquifer layer and bedrock layer (Layer 1- Layer 5). The evaluation of the model output was assessed using Nash-Sutcliffe efficiency (NSE), root mean square error-observations standard deviation ratio (RSR), and percent bias (PBIAS). Using long time-series of discharge records for calibration, the simulated

  14. Mitigating Agricultural Diffuse Pollution: Learning from The River Eden Demonstration Test Catchment Experiments

    Science.gov (United States)

    Reaney, S. M.; Barker, P. A.; Haygarth, P.; Quinn, P. F.; Aftab, A.; Barber, N.; Burke, S.; Cleasby, W.; Jonczyk, J. C.; Owen, G. J.; Perks, M. T.; Snell, M. A.; Surridge, B.

    2016-12-01

    Freshwater systems continue to fail to achieve their ecological potential and provide associated ecological services due to poor water quality. A key driver of the failure to achieve good status under the EU Water Framework Directive derives from non-point (diffuse) pollution of sediment, phosphorus and nitrogen from agricultural landscapes. While many mitigation options exist, a framework is lacking which provides a holistic understanding of the impact of mitigation scheme design on catchment function and agronomics. The River Eden Demonstration Test Catchment project (2009-2017) in NW England uses an interdisciplinary approach including catchment hydrology, sediment-nutrient fluxes and farmer attitudes, to understand ecological function and diffuse pollution mitigation feature performance. Water flow (both surface and groundwater) and quality monitoring focused on three ca. 10km2 catchments with N and P measurements every 30 minutes. Ecological status was determined by monthly diatom community analysis and supplemented by macrophyte, macroinvertebrate and fish surveys. Changes in erosion potential and hydrological connectivity were monitored using extensive Landsat images and detailed UAV monitoring. Simulation modelling work utilised hydrological simulation models (CRAFT, CRUM3 and HBV-Light) and SCIMAP based risk mapping. Farmer behaviour and attitudes have been assessed with surveys, interviews and diaries. A suite of mitigation features have been installed including changes to land management - e.g. aeriation, storage features within a `treatment train', riparian fencing and woodland creation. A detailed dataset of the integrated catchment hydrological, water quality and ecological behaviour over multiple years, including a drought period and an extreme rainfall event, highlights the interaction between ecology, hydrological and nutrient dynamics that are driven by sediment and nutrients exported within a small number of high magnitude storm events. Hence

  15. Modelling the impact of forest loss on shallow landslide sediment yield, Ijuez river catchment, Spanish Pyrenees

    Directory of Open Access Journals (Sweden)

    2007-01-01

    Full Text Available The SHETRAN model for simulating the sediment yield arising from shallow landslides at the scale of a river catchment was applied to the 45-km2 Ijuez catchment in the central Spanish Pyrenees, to investigate the effect of loss of forest cover on landslide and debris flow incidence and on catchment sediment yield. The application demonstrated how such a model, with a large number of parameters to be evaluated, can be used even when directly measured data are not available: rainfall and discharge time series were generated by reference to other local records and data providing the basis for a soil map were obtained by a short field campaign. Uncertainty bounds for the outputs were determined as a function of the uncertainty in the values of key model parameters. For a four-year period and for the existing forested state of the catchment, a good ability to simulate the observed long term spatial distribution of debris flows (represented by a 45-year inventory and to determine catchment sediment yield within the range of regional observations was demonstrated. The lower uncertainty bound on simulated landslide occurrence approximated the observed annual rate of landsliding and suggests that landslides provide a relatively minor proportion of the total sediment yield, at least in drier years. A scenario simulation in which the forest cover was replaced by grassland indicated an increase in landsliding but a decrease in the number of landslides which evolve into debris flows and, at least for drier years, a reduction in sediment delivery to the channel network.

  16. Karst groundwater protection in the Kupa River catchment area and sustainable development

    Science.gov (United States)

    Biondić, B.; Biondić, R.; Kapelj, S.

    2006-03-01

    One of the most significant water resources in the Republic of Croatia is the catchment area of the Kupa River, located in the region bordering the Republic of Slovenia. About 88% of the total amount of water in this catchment originates in Croatia and just 12% from Slovenia; therefore, the largest part of the catchment area (about 1000 km2) is on the Croatian side of the border. It is a typical karst area of the Dinarides with aquifers characterized by a relatively rapid water exchange, high groundwater flow velocities and aquifers open to human impact from the surface. Consequently, the aquifers are highly vulnerable and at risk. Due to the availability of large quantities of high-quality spring water (about 6 m3/s), the entire area has a strategic importance within the context of any future development strategy pertaining to the western part of Croatia. The catchment area on the Croatian side was investigated using a wide range of research methods that included a classical hydrogeological approach, the detailed hydrologic calculation of water balance to the hydrogeochemical analyses and modelling. The objective was to determine protection zones and protection measures for the whole area. The difficulties are increased due to the fact that the karst catchment area is crossed by major traffic corridors, oil pipelines and a railway and that many settlements and a highly developed wood industry are present. The combination of protecting water resources with adequate prevention measures and necessary remedial activities that should satisfy the very strict requirements necessary for the protection of the karst aquifers while still allowing for present and future human activities is difficult but not impossible to achieve. One good example is the present highway with a closed dewatering system and waste water treatment before the water passes into the karst underground system.

  17. Catchment structure that supports organic matter providing a natural control on rising river nutrient concentrations

    Science.gov (United States)

    Stutter, Marc; Ibiyemi, Adekunle; Wang, Chen

    2017-04-01

    The connectivity of sources of pollution in catchments has been well studied and brings concepts such as pollution hotspots and critical source areas. However, consideration of the placement of other structures combating rising pollution impacts has been less considered. One such area that is receiving developing focus is the layout of riparian management and buffer strips. However, there are wider aspects of connectivity and landscape structure that can bring benefits to delivery and in-stream processing of pollution. These include wetlands, forests and the distribution of soils of differing connectivity of organic matter varying in bioavailability. Organic matter is a great modulator of catchment processes from controlling the potential of land use (e.g. constraints of soil organic matter and wetness on agricultural use), to the amount and form of nutrients leached from soils, to controls of dissolved organic matter on in-stream biology that responds to nutrient concentrations. As the fundamental control of ecosystem energy available for many heterotrophic processes it mediates uptake, recycling and speciation of N, P at many stages of the catchment from soils to waters; as such DOM can be considered as a nature-based solution exerting a background level of control on inorganic nutrients. This poster explores the role of different structural aspects of catchments that provide beneficial organic matter inputs to rivers. At the fine scale the lability of riparian soil and leaf litter DOC are considered. At a riparian management scale the local changes in buffer strip soil C and DOC relative to field soils are considered. At the largest scale spatial data are explored for riparian structure, forests, wetlands and soils differing in delivery and forms of C across major Scottish rivers and used as co-variates to explain differences in in-stream processing of nutrients.

  18. A theoretical assessment of microplastic transport in river catchments and their retention by soils and river sediments.

    Science.gov (United States)

    Nizzetto, Luca; Bussi, Gianbattista; Futter, Martyn N; Butterfield, Dan; Whitehead, Paul G

    2016-08-10

    The presence of microplastics (MPs) in the environment is a problem of growing concern. While research has focused on MP occurrence and impacts in the marine environment, very little is known about their release on land, storage in soils and sediments and transport by run-off and rivers. This study describes a first theoretical assessment of these processes. A mathematical model of catchment hydrology, soil erosion and sediment budgets was upgraded to enable description of MP fate. The Thames River in the UK was used as a case study. A general lack of data on MP emissions to soils and rivers and the mass of MPs in agricultural soils, limits the present work to serve as a purely theoretical, nevertheless rigorous, assessment that can be used to guide future monitoring and impact evaluations. The fundamental assumption on which modelling is based is that the same physical controls on soil erosion and natural sediment transport (for which model calibration and validation are possible), also control MP transport and storage. Depending on sub-catchment soil characteristics and precipitation patterns, approximately 16-38% of the heavier-than-water MPs hypothetically added to soils (e.g. through routine applications of sewage sludge) are predicted to be stored locally. In the stream, MPs impact assessments should prioritize these environments.

  19. Evidence of viral dissemination and seasonality in a Mediterranean river catchment: Implications for water pollution management.

    Science.gov (United States)

    Rusiñol, Marta; Fernandez-Cassi, Xavier; Timoneda, Natàlia; Carratalà, Anna; Abril, Josep Francesc; Silvera, Carolina; Figueras, Maria José; Gelati, Emiliano; Rodó, Xavier; Kay, David; Wyn-Jones, Peter; Bofill-Mas, Sílvia; Girones, Rosina

    2015-08-15

    Conventional wastewater treatment does not completely remove and/or inactive viruses; consequently, viruses excreted by the population can be detected in the environment. This study was undertaken to investigate the distribution and seasonality of human viruses and faecal indicator bacteria (FIB) in a river catchment located in a typical Mediterranean climate region and to discuss future trends in relation to climate change. Sample matrices included river water, untreated and treated wastewater from a wastewater treatment plant within the catchment area, and seawater from potentially impacted bathing water. Five viruses were analysed in the study. Human adenovirus (HAdV) and JC polyomavirus (JCPyV) were analysed as indicators of human faecal contamination of human pathogens; both were reported in urban wastewater (mean values of 10(6) and 10(5) GC/L, respectively), river water (10(3) and 10(2) GC/L) and seawater (10(2) and 10(1) GC/L). Human Merkel Cell polyomavirus (MCPyV), which is associated with Merkel Cell carcinoma, was detected in 75% of the raw wastewater samples (31/37) and quantified by a newly developed quantitative polymerase chain reaction (qPCR) assay with mean concentrations of 10(4) GC/L. This virus is related to skin cancer in susceptible individuals and was found in 29% and 18% of river water and seawater samples, respectively. Seasonality was only observed for norovirus genogroup II (NoV GGII), which was more abundant in cold months with levels up to 10(4) GC/L in river water. Human hepatitis E virus (HEV) was detected in 13.5% of the wastewater samples when analysed by nested PCR (nPCR). Secondary biological treatment (i.e., activated sludge) and tertiary sewage disinfection including chlorination, flocculation and UV radiation removed between 2.22 and 4.52 log10 of the viral concentrations. Climate projections for the Mediterranean climate areas and the selected river catchment estimate general warming and changes in precipitation distribution

  20. Streamflow response to climate variability and human activities in the upper catchment of the Yellow River Basin

    Institute of Scientific and Technical Information of China (English)

    ZHAO FangFang; XU ZongXue; ZHANG Lu; ZUO DePeng

    2009-01-01

    Both sensitivity-based method and simulation method are used to analyze the streamflow response to climate variability and human activities in the upper catchment of the Yellow River Basin (UYRB) in this study.The separation regime of effects from climate variability and human activities is investigated.Results show that the changes of streamflow are more sensitive to precipitation than potential evapotranspiration (PET).Effect of climate variability on streamflow estimated using the sensitiv-ity-based method is weak in the upper catchment of Jimai station, and strong in the upper catchment of Lanzhou station, where the climate effects accounted for about 50% of total streamflow changes.Effects of human activities on streamflow accounted for about 40% in the UYRB, with weaker effects in the upper catchment of Tangnaihai station than those in the upper catchment of Lanzhou station.Both climate variability and human activities are main factors to affect the changes of streamflow in the UYRB.

  1. Streamflow response to climate variability and human activities in the upper catchment of the Yellow River Basin

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Both sensitivity-based method and simulation method are used to analyze the streamflow response to climate variability and human activities in the upper catchment of the Yellow River Basin (UYRB) in this study. The separation regime of effects from climate variability and human activities is investigated. Results show that the changes of streamflow are more sensitive to precipitation than potential evapotranspiration (PET). Effect of climate variability on streamflow estimated using the sensitivity-based method is weak in the upper catchment of Jimai station, and strong in the upper catchment of Lanzhou station, where the climate effects accounted for about 50% of total streamflow changes. Effects of human activities on streamflow accounted for about 40% in the UYRB, with weaker effects in the upper catchment of Tangnaihai station than those in the upper catchment of Lanzhou station. Both climate variability and human activities are main factors to affect the changes of streamflow in the UYRB.

  2. Flood Hazard Mapping Assessment for El-Awali River Catchment-Lebanon

    Science.gov (United States)

    Hdeib, Rouya; Abdallah, Chadi; Moussa, Roger; Hijazi, Samar

    2016-04-01

    River flooding prediction and flood forecasting has become an essential stage in the major flood mitigation plans worldwide. Delineation of floodplains resulting from a river flooding event requires coupling between a Hydrological rainfall-runoff model to calculate the resulting outflows of the catchment and a hydraulic model to calculate the corresponding water surface profiles along the river main course. In this study several methods were applied to predict the flood discharge of El-Awali River using the available historical data and gauging records and by conducting several site visits. The HEC-HMS Rainfall-Runoff model was built and applied to calculate the flood hydrographs along several outlets on El-Awali River and calibrated using the storm that took place on January 2013 and caused flooding of the major Lebanese rivers and by conducting additional site visits to calculate proper river sections and record witnesses of the locals. The Hydraulic HEC-RAS model was then applied to calculate the corresponding water surface profiles along El-Awali River main reach. Floodplain delineation and Hazard mapping for 10,50 and 100 years return periods was performed using the Watershed Modeling System WMS. The results first show an underestimation of the flood discharge recorded by the operating gauge stations on El-Awali River, whereas, the discharge of the 100 years flood may reach up to 506 m3/s compared by lower values calculated using the traditional discharge estimation methods. Second any flooding of El-Awali River may be catastrophic especially to the coastal part of the catchment and can cause tragic losses in agricultural lands and properties. Last a major floodplain was noticed in Marj Bisri village this floodplain can reach more than 200 meters in width. Overall, performance was good and the Rainfall-Runoff model can provide valuable information about flows especially on ungauged points and can perform a great aid for the floodplain delineation and flood

  3. Transport of dissolved carbon and CO2 degassing from a river system in a mixed silicate and carbonate catchment

    Science.gov (United States)

    Khadka, Mitra B.; Martin, Jonathan B.; Jin, Jin

    2014-05-01

    Assessing the origin, transformation and transport of terrestrially derived carbon in river systems is critical to regional and global carbon cycles, particularly in carbonate terrains, which represent the largest carbon reservoir on the earth’s surface. For this reason, we evaluated sources, cycling, and fluxes of dissolved organic and inorganic carbon (DOC and DIC) and riverine CO2 degassing to the atmosphere in the Santa Fe River in north-central Florida, a sub-tropical river that flows across two distinct hydrogeological settings of a region dominated by carbonate karst. One setting occurs in the upper river catchment, where the carbonate Floridan aquifer is confined by the siliciclastic Hawthorn Group, while the other setting occurs in the lower catchment where the river flows across the unconfined Floridan aquifer. The upper catchment is characterized by DOC-rich and DIC-poor water and the DIC has more variable and lower δ13C values compared to the lower catchment. The river in the upper catchment degasses more CO2 to the atmosphere (1156 g C m-2 yr-1) than in the lower catchment (402 g C m-2 yr-1) because soil respired carbon and organic matter decomposition increase dissolved CO2 concentration, much of which is consumed during carbonate dissolution reactions in the lower catchment. The CO2 flux from the water surface to the atmosphere during a flood event is three times greater than during base flow, suggesting that excess precipitation flushes soil organic carbon to the river through interflow and enhances the loss of terrestrial carbon via river water to the atmosphere. Our values of CO2 fluxes to the atmosphere lie within the range of fluxes from the world’s rivers, but fluxes from the carbonate dominated region are at the low end, while fluxes from the siliciclastic region are at the high end. These results indicate that catchment lithologies, particularly whether carbonate or siliciclastic, as well as flow, are critical to carbon budgets in rivers

  4. The River EdenDTC Project: A National Demonstration Test Catchment

    Science.gov (United States)

    Benskin, C.; Surridge, B.; Deasy, C.; Woods, C.; Rimmer, D.; Lees, E.; Owens, G.; Jonczyk, J.; Quinton, J.; Wilkinson, M.; Perks, M.; Quinn, P.; Barker, P.; Haygarth, P.; Burke, S.; Reaney, S.; Watson, N.

    2012-04-01

    Our environment is a complex system of interactions between natural process and anthropogenic activities that disrupt them. It is crucial to manage the balance for continued food production whilst maintaining the quality of the environment. The challenges we face include managing the impact of agricultural land use on aquatic quality and biodiversity as an integral system, rather than as separate issues. In order to do this, it is critical to understand how the different components are linked - how does land use affect our water courses and ground water, and their associated ecosystems, and how can the impact of agricultural land use on these systems be minimised? Regulating farm nutrient management through measures that minimise sources, their exposure to mobilisation, and reduce drainage pathways to water courses are all fundamental to the UK's approach to meeting the Water Framework Directive objective of achieving 'good ecological status' in all surface and groundwater bodies by 2015. The EdenDTC project is part of a 5-year national Demonstration Test Catchments (DTC) environmental scheme, aiming to understand the above issues through combining scientific research with local knowledge and experience from multiple stakeholders. The DTC project is a 5-year initiative by Defra, Welsh Assembly Government and the Environment Agency, which encompasses a research platform covering three distinct river catchments: the Eden in Cumbria; the Wensum in Norfolk; and the Avon in Hampshire. Within the EdenDTC, the impact and effects of multiple diffuse pollutants on ecosystems and sustainable food production are being studied on a river catchment scale. Three 10 km2 focus catchments, selected to represent the different farming practices and geologies observed across the Eden, have been instrumented to record the dynamics of agricultural diffuse pollution at multiple scales. Within each focus catchment, two sub-catchments were selected: one control and one mitigation, in which

  5. Calibration of the sodium base cation dominance index of weathering for the River Dee catchment in north-east Scotland

    Energy Technology Data Exchange (ETDEWEB)

    Stutter, M. [Aberdeen Univ. (United Kingdom). Dept. of Plant and Soil Science; Smart, R.; Cresser, M. [York Univ. (United Kingdom). Environmental Dept.

    2002-07-01

    Previously the dominance of base cations by Na{sup +} in river water in upland catchments with low weathering rates and influenced by marine-derived aerosols has been suggested as a quantitative index of weathering rate upstream of the sampling point. Using data for 59 sites from a study of the River Dee catchment in NE Scotland, the index has been fully calibrated against catchment weathering rates and net alkalinity production, derived through input output budget methods, for both upland and agricultural catchments and over a wide range of parent materials. It is shown that the relationship between Na{sup +} dominance and weathering rate is logarithmic, rather than linear as initially suggested. The excellent correlations highlight the potential use of this Na{sup +} dominance index for the direct quantification of catchment susceptibility to acidification at fine spatial resolution, using a few simple and inexpensive measurements. Stronger correlations were observed between the % Na{sup +} dominance and net annual flux of alkalinity than between % Na{sup +} dominance and weathering rate derived from summation of base cation fluxes. This demonstrates the importance of mechanisms controlling the transport of base cations out of catchments, namely in association with organic matter and with anthropogenically derived SO{sub 4}{sup 2-}. These processes are shown to reduce the residual alkalinity derived through weathering. The partial neutralization of organic acidity by internally generated alkalinity has implications in the context of using the mass balance approach for setting critical loads for catchments. (Author)

  6. Integrated analysis of water quality parameters for cost-effective faecal pollution management in river catchments.

    Science.gov (United States)

    Nnane, Daniel Ekane; Ebdon, James Edward; Taylor, Huw David

    2011-03-01

    In many parts of the world, microbial contamination of surface waters used for drinking, recreation, and shellfishery remains a pervasive risk to human health, especially in Less Economically Developed Countries (LEDC). However, the capacity to provide effective management strategies to break the waterborne route to human infection is often thwarted by our inability to identify the source of microbial contamination. Microbial Source Tracking (MST) has potential to improve water quality management in complex river catchments that are either routinely, or intermittently contaminated by faecal material from one or more sources, by attributing faecal loads to their human or non-human sources, and thereby supporting more rational approaches to microbial risk assessment. The River Ouse catchment in southeast England (U.K.) was used as a model with which to investigate the integration and application of a novel and simple MST approach to monitor microbial water quality over one calendar year, thereby encompassing a range of meteorological conditions. A key objective of the work was to develop simple low-cost protocols that could be easily replicated. Bacteriophages (viruses) capable of infecting a human specific strain of Bacteroides GB-124, and their correlation with presumptive Escherichia coli, were used to distinguish sources of faecal pollution. The results reported here suggest that in this river catchment the principal source of faecal pollution in most instances was non-human in origin. During storm events, presumptive E. coli and presumptive intestinal enterococci levels were 1.1-1.2 logs higher than during dry weather conditions, and levels of the faecal indicator organisms (FIOs) were closely associated with increased turbidity levels (presumptive E. coli and turbidity, r = 0.43). Spatio-temporal variation in microbial water quality parameters was accounted for by three principal components (67.6%). Cluster Analysis, reduced the fourteen monitoring sites to six

  7. Hydrogeochemical and Biogeochemical Processes in Kaffiøyra River Catchments (Spitsbergen, Norway

    Directory of Open Access Journals (Sweden)

    Borysiak Janina

    2015-03-01

    Full Text Available The paper presents the results of hydrogeochemical and biogeochemical studies in the area of Kaffiøyra river catchments in the ablation season 2004. Vegetation, hydrological regime, mineralization and ionic composition of circulating waters, rate of annual chemical denudation and biogenic CO2 content in soil air in relation to the concentration of dissolved and transported HCO3 - ions were documented. The waters represented the type HCO3 - - SO42- - Ca2+ - Mg2+. Most of ions showed a good correlation with electrical conductivity. A good correlation between dissolved and transported mass and the discharge was shown. The value of the chemical denudation in non-glacierized catchments of the Kaffiøyra plain was 0.07 and 0.13 t km-2 d-1, in glacierized catchment - 0,21 t km-2 d-1. The biogenic CO2 concentrations in tundra soil air ranged from 0.03-0.08%, while the average was 0.046%. The mean rate of CO2 ionic transport was 3 kg d-1, while of HCO3 - - 0.63 t d-1. A low correlation between the concentration of biogenic CO2 in soil air and HCO3 - was found, which indicates the involvement of other, unexamined bio- and physico-chemical processes.

  8. Characteristics of Winters Conditions and Floods in Small, Lowland River Catchment

    Science.gov (United States)

    Hejduk, Agnieszka; Hejduk, Leszek

    2014-05-01

    Characteristics of thermal and snowy conditions of winters and winter floods recorded at Czarna gauging station on Zagożdżonka River (central Poland) are given in the paper. The catchment area till Czarna station is 24.3 km2, but to direct runoff and sediment delivery to river system contributes 19.6 km2 . The mean annual precipitation and runoff are estimated at 606 mm and 107 mm respectively. The snow cover usually appears between 25-30 of November and disappears between 20-25 of March. Land use in the catchment upstream of Czarna is dominated by arable land (70 percent). 20 percent of area is covered by forest, 9.4 percent is pastures and 0.6 percent is paved areas. Based on maximum, minimum, mean diurnal air temperatures and daily snow cover depth, thermal and snow conditions of winters have been characterized by using empirical indexes proposed by Paczos (Paczos, 1982, 1985). Rather cold and extraordinarily low snowy winters has dominated in Zagożdżonka catchment. There is a significant statistical relationship between winter snowiness index (WSn) and winter severity index (WOz ) with R=0.83, α = 0.05. Water discharge, rainfall and air temperature have been used to identify snowmelt periods and catchment response on water supply. Winter floods as a result of snowmelt have been observed almost each year. The total supply of analyzed cases varied from 69.3 to 10 mm, the peak discharge varied from 0.114 to 3.44 m3/s . Catchment response under different thermal and snowy conditions of winters varied from droughts to floods. There is statistical significant relation between maximum water discharge and snowiness conditions expressed by WSn index (R=0.66, α= 0.05). The investigations were carried on within the research project funded by National Science Center References: PACZOS S., 1982. Stosunki termiczne i śnieżne zim w Polsce. Unpublished dissertation, UMCS, Lublin PACZOS S., 1985. Zagadnienia klasyfikacji zim w świetle różnych kryteriów termicznych

  9. Environmental heterogeneity at different scales: key factors affecting caddisfly larvae assemblages in standing waters within a lowland river catchment

    Directory of Open Access Journals (Sweden)

    Edyta Buczyńska

    2016-11-01

    Full Text Available We examined the importance of environmental parameters at different spatial scales influencing the occurrence of caddisfly larvae at different levels of their organization (species, faunistic metrics and functional groups in lentic floodplain waters, in order to gain information on the ecological status and management of a small lowland river catchment. At the lowest spatial level – pH, sediment grain size, insolation and the presence of aquatic macrophytes proved significant for caddisfly larvae, at higher and the highest level (including buffer zones and the catchment – the surface areas of watercourses and the river, distance from standing waters and distance from broadleaf forests, respectively. Rheophilous hydropsychids accounted for 17% of the whole fauna of the examined water bodies. They spread from the river via water during flood in the spring. We also detected some significant correlations between functional groups of caddisfly larvae and parameters describing buffer zones and the river catchment against the sub-catchment type use. Information provided by the Caddisfly Habitat Index showed an overall  good ecological status of the river-floodplain. Caddisfly larvae may be good indicators of numerous factors and processes, but they should be studied comprehensively, at different levels of organization. Our results can be useful for preservation of biodiversity and management of river valleys. We suggest: 1 maintaining the varied structure of aquatic macrophytes in water bodies, 2 securing the long-term presence of broadleaf trees in buffer zones in order to provide detritus input, varied insolation and shelter for caddisflies, 3 limiting drainage activities in the river valley in order to save varied habitats, especially temporary ones, 4 providing heterogeneous landscape in the river catchment (homogenous land use is inappropriate. 

  10. Morphometric properties of the trans-Himalayan river catchments: Clues towards a relative chronology of orogen-wide drainage integration

    Science.gov (United States)

    Ghosh, Parthasarathi; Sinha, Sayan; Misra, Arindam

    2015-03-01

    The geomorphological evolution of the Himalayan mountain belt both in terms of crustal deformation and concomitant erosion by surface processes has been suggested to have a profound influence on a number of earth system processes and has been extensively researched through a number of different techniques. The huge catchments of the trans-Himalayan rivers are the product of long-term fluvial erosion of the landscape. This work attempts to understand their evolution through a study of drainage network, morphology, and internal organization of the smaller watersheds nested within each catchment. Using morphometric techniques applied to an orogen-wide digital elevation data grid, we characterized the drainage network structure and catchment of all the 18 trans-Himalayan rivers situated between the exits of the Indus and Brahmaputra rivers and constructed rectangular approximations of the catchment geometries. With the help of catchment dimensions measured transverse and parallel to the strike of the orogen, and by analyzing the dimension and spatial dispositions of the rectangular approximations, we demonstrate that the trans-Himalayan catchment shapes cannot be explained only as a product of the headward enlargement of drainage networks on a topographic slope, or orogenic taper. Within individual catchments we identified the existence of drainage components (watersheds) that are organized in a systematic manner with respect to the first-order physiographic features of the Himalayas, formed at different periods of geological time. Each of them shows distinct morphometric characteristics that are indicative of differences in processes and / or time scale involved in their formation. The hypsometric properties of the watersheds occupying the upper part of the catchments suggest that they are the remnants of pre-orogenic drainage that became confined to the leeward side of the Himalayas before the advent of monsoon circulation. The shape and organization of the

  11. Meltwater chemistry and solute export from a Greenland Ice Sheet catchment, Watson River, West Greenland

    DEFF Research Database (Denmark)

    Yde, Jacob C; Knudsen, N. Tvis; Hasholt, Bent

    2014-01-01

    –2010 for the Watson River sector of the GrIS that drains into the fjord Kangerlussuaq. The hydrochemistry is dominated by Ca2+ and HCO3− with a relatively high molar K+/Na+ ratio of 0.6 ± 0.1, typical for meltwaters draining a gneissic lithology. Low molar Ca2+/Na+ and Mg2+/Na+ ratios indicate that weathering....... However, when normalized by discharge the denudation rates are comparable to other Arctic sites. When extrapolating the results from the Watson River catchment to the entire Greenland for 2007–2010, the solute export from Greenland meltwater varied between 7.1 × 106 and 7.8 × 106 tons, whilst the major...

  12. Environmental isotopic and hydrochemical characteristics of groundwater from the Sandspruit Catchment, Berg River Basin, South Africa.

    Science.gov (United States)

    Naicker, S; Demlie, M

    2014-01-01

    The Sandspruit catchment (a tributary of the Berg River) represents a drainage system, whereby saline groundwater with total dissolved solids (TDS) up to 10,870 mg/l, and electrical conductivity (EC) up to 2,140 mS/m has been documented. The catchment belongs to the winter rainfall region with precipitation seldom exceeding 400 mm/yr, as such, groundwater recharge occurs predominantly from May to August. Recharge estimation using the catchment water-balance method, chloride mass balance method, and qualified guesses produced recharge rates between 8 and 70 mm/yr. To understand the origin, occurrence and dynamics of the saline groundwater, a coupled analysis of major ion hydrochemistry and environmental isotopes (δ(18)O, δ(2)H and (3)H) data supported by conventional hydrogeological information has been undertaken. These spatial and multi-temporal hydrochemical and environmental isotope data provided insight into the origin, mechanisms and spatial evolution of the groundwater salinity. These data also illustrate that the saline groundwater within the catchment can be attributed to the combined effects of evaporation, salt dissolution, and groundwater mixing. The salinity of the groundwater tends to vary seasonally and evolves in the direction of groundwater flow. The stable isotope signatures further indicate two possible mechanisms of recharge; namely, (1) a slow diffuse type modern recharge through a relatively low permeability material as explained by heavy isotope signal and (2) a relatively quick recharge prior to evaporation from a distant high altitude source as explained by the relatively depleted isotopic signal and sub-modern to old tritium values.

  13. Relationship between catchment characteristics and forms of nitrogen in Cao-E River Basin, Eastern China

    Institute of Scientific and Technical Information of China (English)

    JIN Shuquan; LU Jun; CHEN Dingjiang; SHEN Yena; SHI Yiming

    2009-01-01

    The distribution of different nitrogen forms and their spatial and temporal variations in different pollution types of tributaries or reaches were investigated. Based on the catchments characteristics the tributaries or reaches can be classified into 4 types including headwater in mountainous areas (type I), agricultural non-point source (NPS) pollution in rural areas (type II), municipal and industrial pollution in urban areas (type III), and combined pollution in the main stream (type IV). Water samples were collected monthly from July 2003 to June 2006 in the Cao-E River basin in Zhejiang, Eastern China. The concentrations of NO3-N, NH4+-N, and total nitrogen (TN) were measured. The mean concentrations of NO3-N were in the order type IV > type II> type III > type I, whereas, NH4+-N, total organic nitrogen (TON), and TN were in the order type III > type IV > type II> type I. In headwater and rural reaches, CNO3-N was much higher than CNH4+-N. In urban reaches, TON and NH4+-N were the main forms, accounting for 54.7% and 32.1% of TN, respectively. In the whole river system, CNH4+-N decrease with increasing distance from cities, and CNO3-N increased with the increasing area of farmland in the catchments. With increased river flow, the CNO3-N increased and the CNH4+-N decreased in all types of reaches, while the variations of CTON and CTN were different. For TN, the concentration may be decreased with the increase of river flow, but the export load always increased.

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

    Science.gov (United States)

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

    2016-08-15

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

  15. A Flash Flood Study on the Small Montaneous River Catchments in Western Romania

    Science.gov (United States)

    Győri, Maria-Mihaela; Haidu, Ionel; Humbert, Joël

    2013-04-01

    interpolated in order to obtain the hydrograph of the historical flash floods. The two methodologies employed offer the hydrologist the opportunity of computing the historical hydrographs be it on a section of the river at choice, or for every affluent within the small river basins studied, the graphical data being easily accessed both in GIS and HEC-HMS. The peak discharge values of the main rivers as well as those of their tributaries are of great importance in establishing the hydrologic hazard under the form of floodplain maps that are inexistent for the studied watersheds. Key words: flash flood modeling, ungauged catchments, GIS, HEC-HMS rainfall-runoff model. Aknowledgements This work was possible with the financial support of the Sectoral Operational Programme for Human Resources Development 2007-2013, co-financed by the European Social Fund, under the project number POSDRU/107/1.5/S/76841 with the title "Modern Doctoral Studies: Internationalization and Interdisciplinarity".

  16. Evaluation and assessment of water quality in Likangala River and its catchment area

    Science.gov (United States)

    Chidya, R. C. G.; Sajidu, S. M. I.; Mwatseteza, J. F.; Masamba, W. R. L.

    Likangala is one of the perennial rivers in Malawi that flow into a closed Lake Chilwa, a designated wetland ratified by Ramsar Convention in 1997. Earlier work conducted on this river revealed considerable social-economic activities at riverbanks resulting in indiscriminate disposal of wastes. This study intended to evaluate water quality in Likangala River and its catchment area. Water samples were collected thrice (dry, early rainy and mid rainy seasons) and tested for major physico-chemical and microbiological parameters. The EC, pH, and selected ions ( NO3-, PO43-, Na +, K +, Mg 2+, and Ca 2+) were analysed in soil samples obtained in crop fields along the river banks. Elevated EC levels (>1035.00 μS/cm) were measured during mid rainy season at site S15 (Zomba Sewage Works), near and in the lake. Most of the water samples (86%, n = 28) registered phosphate levels above 1.50 mg/L during mid rainy season with a maximum value (10.70 ± 0.01 mg/L) at site S15. Lower amounts (control of water, land use and waste management in order to prevent escalation of the effects.

  17. Investigating the potential to reduce flood risk through catchment-based land management techniques and interventions in the River Roe catchment, Cumbria,UK

    Science.gov (United States)

    Pearson, Callum; Reaney, Sim; Bracken, Louise; Butler, Lucy

    2015-04-01

    Throughout the United Kingdom flood risk is a growing problem and a significant proportion of the population are at risk from flooding throughout the country. Across England and Wales over 5 million people are believed to be at risk from fluvial, pluvial or coastal flooding (DEFRA, 2013). Increasingly communities that have not dealt with flooding before have recently experienced significant flood events. The communities of Stockdalewath and Highbridge in the Roe catchment, a tributary of the River Eden in Cumbria, UK, are an excellent example. The River Roe has a normal flow of less than 5m3 sec-1 occurring 97 percent of the time however there have been two flash floods of 98.8m3 sec-1 in January 2005 and 86.9m3 sec-1 in May 2013. These two flash flood events resulted in the inundation of numerous properties within the catchment with the 2013 event prompting the creation of the Roe Catchment Community Water Management Group which aims are to deliver a sustainable approach to managing the flood risk. Due to the distributed rural population the community fails the cost-benefit analysis for a centrally funded flood risk mitigation scheme. Therefore the at-risk community within the Roe catchment have to look for cost-effective, sustainable techniques and interventions to reduce the potential negative impacts of future events; this has resulted in a focus on natural flood risk management. This research investigates the potential to reduce flood risk through natural catchment-based land management techniques and interventions within the Roe catchment; providing a scientific base from with further action can be enacted. These interventions include changes to land management and land use, such as soil aeration and targeted afforestation, the creation of runoff attenuation features and the construction of in channel features, such as debris dams. Natural flood management (NFM) application has been proven to be effective when reducing flood risk in smaller catchments and the

  18. Water quality assessment of the Asata River catchment area in Enugu Metropolis, Southeast Nigeria

    Science.gov (United States)

    Osinowo, Olawale Olakunle

    2016-09-01

    Hydrogeochemical mapping of the Asata River Catchment area in the Enugu metropolis, southeast Nigeria was carried out in order to assess the quality of the surface and groundwater and based on the analyses of the hydrogeochemical data, establish the level of chemical contaminations which inhibit the availability of potable water in the area. Forty (40) water samples comprising five (5) springs, nineteen (19) surface (streams/rivers) and sixteen (16) groundwater (well/borehole) samples were collected and analysed for the presence and degree of contamination of nine (9) major chemical contaminants. Hydrochemical analyses indicate that Electrical Conductivity (EC) which has a linear relationship with Total Dissolved Solid (TDS) ranges between 015 and 887 μS/cm, pH between 4.4 and 8.3, nitrate (NO3-) ranges between 40 and 130 mg/l and chloride (Cl-) between 7 and 130 mg/l. The concentrations of the dissolved chemical constituents defined the pollution trend and the rate of dispersion of contaminants. The degree of contaminants followed a simple trend, where the level of contamination of the dissolved chemical constituents is least in sampled spring water, with measured chemical constituents of EC, pH, NO3- and Cl- range from 15 to 354 μS/cm; 6.4-6.5; 4.0-70 mg/l and 8-36 mg/l, respectively. However, the value of the measured chemical constituent of EC, pH, NO3- and Cl- gradually increases down the stream in both the surface (63-354 μS/cm; 4.5-7.7; 7.1-110 mg/l; 8-41 mg/l) and groundwater (56-531 μS/cm; 4.5-7.5; 40-130 mg/l; 7-130 mg/l), respectively. Noticeable peaks in contamination levels characterised sections of the study area where human population or their activities is highest. The result of the hydrogeochemical mapping indicate that Enugu coal mine operation, the industrial activities, fertilizer applied to plants cultivated on river banks and domestic human wastes which are indiscriminately dumped along river channels are the major sources of chemical

  19. Participatory scenario development for integrated assessment of nutrient flows in a Catalan river catchment

    Directory of Open Access Journals (Sweden)

    F. Caille

    2007-05-01

    Full Text Available Rivers in developed regions are under significant stress due to nutrient enrichment generated mainly by human activities. Excess nitrogen and phosphorus emissions are the product of complex dynamic systems influenced by various factors such as demographic, socio-economic and technological development. Using a Catalan river catchment, La Tordera (North-East of Spain, as a case study of an integrated and interdisciplinary environmental assessment of nutrient flows, we present and discuss the development of socio-economic scenarios through a participatory process for the sustainable management of the anthropogenic sources of nutrients, nitrogen and phosphorus. In this context, scenarios are an appropriate tool to assist nutrient emissions modelling, and to assess impacts, possible pathways for socio-economic development and associated uncertainties. Evaluated against the 1993–2003 baseline period, scenarios target the 2030 horizon, i.e., through the implementation process of the Water Framework Directive (Directive 2000/60/EC. After a critical examination of the methodology used in the participatory development of socio-economic scenarios, we present four possible futures (or perspectives for the Catalan river catchment conceived by stakeholders invited to a workshop. Keys to the success of such a participatory process were trust, which enhanced openness, and disagreements, which fostered the group's creativity for scenario development. The translation of narrative socio-economic scenarios into meaningful nutrient emission scenarios is also presented. By integrating findings of natural sciences and socio-economic analysis, we aim to assist decision makers and stakeholders in evaluating optimal management strategies for the anthropogenic sources of nitrogen and phosphorus.

  20. Participatory scenario development for integrated assessment of nutrient flows in a Catalan river catchment

    Directory of Open Access Journals (Sweden)

    F. Caille

    2007-11-01

    Full Text Available Rivers in developed regions are under significant stress due to nutrient enrichment generated mainly by human activities. Excess nitrogen and phosphorus emissions are the product of complex dynamic systems influenced by various factors such as demographic, socio-economic and technological development. Using a Catalan river catchment, La Tordera (North-East of Spain, as a case study of an integrated and interdisciplinary environmental assessment of nutrient flows, we present and discuss the development of narrative socio-economic scenarios through a participatory process for the sustainable management of the anthropogenic sources of nutrients, nitrogen and phosphorus. In this context, scenarios are an appropriate tool to assist nutrient emissions modelling, and to assess impacts, possible pathways for socio-economic development and associated uncertainties. Evaluated against the 1993–2003 baseline period, scenarios target the 2030 horizon, i.e. through the implementation process of the Water Framework Directive (Directive 2000/60/EC. After a critical examination of the methodology used in the participatory development of socio-economic scenarios, we present four possible futures (or perspectives for the Catalan river catchment conceived by stakeholders invited to a workshop. Keys to the success of such a participatory process were trust, which enhanced openness, and disagreements, which fostered the group's creativity for scenario development. The translation of narrative socio-economic scenarios into meaningful nutrient emission scenarios is also discussed. By integrating findings of natural sciences and socio-economic analysis, we aim to assist decision makers and stakeholders in evaluating optimal management strategies for the anthropogenic sources of nitrogen and phosphorus.

  1. Participatory scenario development for integrated assessment of nutrient flows in a Catalan river catchment

    Science.gov (United States)

    Caille, F.; Riera, J. L.; Rodríguez-Labajos, B.; Middelkoop, H.; Rosell-Melé, A.

    2007-11-01

    Rivers in developed regions are under significant stress due to nutrient enrichment generated mainly by human activities. Excess nitrogen and phosphorus emissions are the product of complex dynamic systems influenced by various factors such as demographic, socio-economic and technological development. Using a Catalan river catchment, La Tordera (North-East of Spain), as a case study of an integrated and interdisciplinary environmental assessment of nutrient flows, we present and discuss the development of narrative socio-economic scenarios through a participatory process for the sustainable management of the anthropogenic sources of nutrients, nitrogen and phosphorus. In this context, scenarios are an appropriate tool to assist nutrient emissions modelling, and to assess impacts, possible pathways for socio-economic development and associated uncertainties. Evaluated against the 1993-2003 baseline period, scenarios target the 2030 horizon, i.e. through the implementation process of the Water Framework Directive (Directive 2000/60/EC). After a critical examination of the methodology used in the participatory development of socio-economic scenarios, we present four possible futures (or perspectives) for the Catalan river catchment conceived by stakeholders invited to a workshop. Keys to the success of such a participatory process were trust, which enhanced openness, and disagreements, which fostered the group's creativity for scenario development. The translation of narrative socio-economic scenarios into meaningful nutrient emission scenarios is also discussed. By integrating findings of natural sciences and socio-economic analysis, we aim to assist decision makers and stakeholders in evaluating optimal management strategies for the anthropogenic sources of nitrogen and phosphorus.

  2. Implementing Integrated Catchment Management in the upper Limpopo River basin: A situational assessment

    Science.gov (United States)

    Mwenge Kahinda, J.; Meissner, R.; Engelbrecht, F. A.

    2016-06-01

    A three-phase study was initiated as a way to promote Integrated Catchment Management approaches in the Limpopo River basin. This paper presents the situational assessment, which should enable De Beers to understand how their Venetia Mine operations are located within a broader and highly dynamic socio-economic and ecohydrological landscape as it pertains to water risks. The second phase, Risk assessment, aims to develop conservation interventions in the identified areas; the third phase will develop mechanisms for implementing water stewardship schemes to mitigate the shared water risks. Analysis of the social-ecological system (hydrological, climatic, ecological, socio-economic and governance systems) of the Limpopo River basin indicates that the institutional arrangement of the Limpopo River basin is neither simple nor effective. The basin is rapidly approaching closure in the sense that almost all of the available supplies of water have already been allocated to existing water users. If the proposed ecological flow requirements were to be met for all of the tributaries, the basin would be 'closed'. On-going and projected land use changes and water resources developments in the upper reaches of the basin, coupled with projected rainfall reductions and temperature increases, and allocation of the flows for the ecological reserve, are likely to further reduce downstream river flows. The coupled increase in temperature and decrease in rainfall is of great concern for everyone in the basin, especially the poorer communities, who rely on rain-fed agriculture for their livelihoods. Increased temperatures also lead to increased evaporation from reservoirs and therefore result in a decrease in water availability. This will lead to increased abstraction of groundwater, especially from alluvial aquifers, and consequently an increase in river transmission losses and a decrease in river flows.

  3. The oxygen isotopic composition of phosphate in river water and its potential sources in the Upper River Taw catchment, UK.

    Science.gov (United States)

    Granger, Steven J; Heaton, Tim H E; Pfahler, Verena; Blackwell, Martin S A; Yuan, Huimin; Collins, Adrian L

    2017-01-01

    The need to reduce both point and diffuse phosphorus pollution to aquatic ecosystems is widely recognised and in order to achieve this, identification of the different pollutant sources is essential. Recently, a stable isotope approach using oxygen isotopes within phosphate (δ(18)OPO4) has been used in phosphorus source tracing studies. This approach was applied in a one-off survey in September 2013 to the River Taw catchment in south-west England where elevated levels of phosphate have been reported. River water δ(18)OPO4 along the main channel varied little, ranging from +17.1 to +18.8‰. This was no >0.3‰ different to that of the isotopic equilibrium with water (Eδ(18)OPO4). The δ(18)OPO4 in the tributaries was more variable (+17.1 to +18.8‰), but only deviated from Eδ(18)OPO4 by between 0.4 and 0.9‰. Several potential phosphate sources within the catchment were sampled and most had a narrow range of δ(18)OPO4 values similar to that of river Eδ(18)OPO4. Discharge from two waste water treatment plants had different and distinct δ(18)OPO4 from one another ranging between +16.4 and +19.6‰ and similar values to that of a dairy factory final effluent (+16.5 to +17.8‰), mains tap water (+17.8 to +18.4‰), and that of the phosphate extracted from river channel bed sediment (+16.7 to +17.6‰). Inorganic fertilizers had a wide range of values (+13.3 to +25.9‰) while stored animal wastes were consistently lower (+12.0 to +15.0‰) than most other sources and Eδ(18)OPO4. The distinct signals from the waste water treatment plants were lost within the river over a short distance suggesting that rapid microbial cycling of phosphate was occurring, because microbial cycling shifts the isotopic signal towards Eδ(18)OPO4. This study has added to the global inventory of phosphate source δ(18)OPO4 values, but also demonstrated the limitations of this approach to identifying phosphate sources, especially at times when microbial cycling is high. Copyright

  4. Effects of River Discharge and Land Use and Land Cover (LULC) on Water Quality Dynamics in Migina Catchment, Rwanda

    NARCIS (Netherlands)

    Uwimana, Brigitte; Dam, van Anne; Gettel, Gretchen; Bigirimana, Bonfils; Irvine, Kenneth

    2017-01-01

    Agricultural intensification may accelerate the loss of wetlands, increasing the concentrations of nutrients and sediments in downstream water bodies. The objective of this study was to assess the effects of land use and land cover and river discharge on water quality in the Migina catchment,

  5. Influence of land use on hyporheos in catchment of the Jarama River (central Spain)

    Science.gov (United States)

    Iepure, S.; Martínez-Hernández, V.; Herrera, S.; de Bustamante, I.; Rasines, R.

    2012-04-01

    The Water Framework Directive (2000) requires integrated assessment of water bodies based on water resources but also the evaluation of land-use catchment effect on chemical and ecological conditions of aquatic ecosystems. The hyporheic zone (HZ) supporting obligate subterranean species are particularly vulnerable in river ecosystems when environmental stress occurs at surface and require management strategies to protect both the stream catchment and the aquifer that feed the stream channel. The influence of catchment land-use in the Jarama basin (central Spain) on river geomorphology and hyporheic zone granulometry, chemical and biological variables inferred from crustacean community biodiversity (species richness, taxonomic distinctness) and ecology was assessed. The study was conducted in four streams from the Madrid metropolitan area under distinct local land-use and water resource protection: i) a preserved forested natural sites where critical river ecosystem processes were unaltered or less altered by human activities, and ii) different degree of anthropogenic impact sites from agriculture, urban industrial and mining activities. The river bed permeability reduction and the increase of low sediment size input associated with changes in geomorphology of the stream channels are greatly affected by land-use changes in the Jarama watershed. Water chemical parameters linked to land-use increase from the natural stream to the urban industrial and agricultural dominated catchment. Principal coordinate analysis (PCO) and multidimensional scaling (MDS) clearly discriminate the pristine sites from forested areas by those under anthropogenic stressors. In streams draining forested areas, groundwater discharge and regular exchange between groundwater and surface water occur due to relatively high permeability of the sediments. Consequently, forested land-use produce sites of high water quality and crustacean richness (both groundwater dwellers and surface

  6. Export of nutrients from the catchment of the upper Szeszupa River (drainage basin of the Neman River and its seasonality

    Directory of Open Access Journals (Sweden)

    Górniak Andrzej

    2016-12-01

    Full Text Available The article presents the dynamics of concentrations and export of nitrogen, phosphorus, TOC in the upper Szeszupa River (tributary of the River Neman in the period from 2000 to 2014 (15 years based on monthly analyses performed in Poland in the scope of the National Environmental Monitoring. The lakeland river with a mean discharge of 1.6 m3 s−1 and catchment dominated by agricultural land exports approximately 20 kg ha−1 of organic carbon compounds per year. The export of nitrogen is insignificant (3.8 kg ha−1 with 55% accounting for the element in the form of organic compounds and 31% for nitrates. Phosphorus export is also relatively low (0.12 kg ha−1, with 30% of the load of TP constituted by orthophosphates. During four months (February–May, 40–60% of annual export of nutrients was discharged, whereas the load of nitrates and organic nitrogen was higher than the contribution of outflowing water. From 2010, an increasing tendency has been observed in organic nitrogen export. This may be related to the intensification of animal production in NE Poland and an increase in livestock density.

  7. Modelling nitrogen and phosphorus loads in a Mediterranean river catchment (La Tordera, NE Spain)

    Science.gov (United States)

    Caille, F.; Riera, J. L.; Rosell-Melé, A.

    2012-08-01

    Human activities have resulted in increased nutrient levels in many rivers all over Europe. Sustainable management of river basins demands an assessment of the causes and consequences of human alteration of nutrient flows, together with an evaluation of management options. In the context of an integrated and interdisciplinary environmental assessment (IEA) of nutrient flows, we present and discuss the application of the nutrient emission model MONERIS (MOdelling Nutrient Emissions into River Systems) to the Catalan river basin, La Tordera (north-east Spain), for the period 1996-2002. After a successful calibration and verification process (Nash-Sutcliffe efficiencies E=0.85 for phosphorus and E=0.86 for nitrogen), the application of the model MONERIS proved to be useful in estimating nutrient loads. Crucial for model calibration, in-stream retention was estimated to be about 50 % of nutrient emissions on an annual basis. Through this process, we identified the importance of point sources for phosphorus emissions (about 94% for 1996-2002), and diffuse sources, especially inputs via groundwater, for nitrogen emissions (about 31% for 1996-2002). Despite hurdles related to model structure, observed loads, and input data encountered during the modelling process, MONERIS provided a good representation of the major interannual and spatial patterns in nutrient emissions. An analysis of the model uncertainty and sensitivity to input data indicates that the model MONERIS, even in data-starved Mediterranean catchments, may be profitably used by water managers for evaluating quantitative nutrient emission scenarios for the purpose of managing river basins. As an example of scenario modelling, an analysis of the changes in nutrient emissions through two different future scenarios allowed the identification of a set of relevant measures to reduce nutrient loads.

  8. Monitoring of metals, organic compounds and coliforms in water catchment points from the Sinos River basin.

    Science.gov (United States)

    Nascimento, C A; Staggemeier, R; Bianchi, E; Rodrigues, M T; Fabres, R; Soliman, M C; Bortoluzzi, M; Luz, R B; Heinzelmann, L S; Santos, E L; Fleck, J D; Spilki, F R

    2015-05-01

    Unplanned use and occupation of the land without respecting its capacity of assimilation and environmental purification leads to the degradation of the environment and of water used for human consumption. Agricultural areas, industrial plants and urban centres developed without planning and the control of effluent discharges are the main causes of water pollution in river basins that receive all the liquid effluents produced in those places. Over the last decades, environmental management has become part of governmental agendas in search of solutions for the preservation of water quality and the restoration of already degraded resources. This study evaluated the conditions of the main watercourse of the Sinos River basin by monitoring the main physical, chemical and microbiological parameters described in the CONAMA Resolution no. 357/2005.The set of parameters evaluated at five catchment points of water human consumption revealed a river that has different characteristics in each reach, as the upper reach was class 1, whereas the middle and lower reaches of the basin were class 4. Monitoring pointed to households as the main sources of pollutants in those reaches, although metals used in the industrial production of the region were found in the samples analyzed.

  9. Analysis on radiocesium concentration in rivers that have catchment areas affected by the fallout from Fukushima Daiichi Nuclear Power Plant

    Science.gov (United States)

    Taniguchi, Keisuke; Yoshimura, Kazuya; Sakaguchi, Aya; Yamamoto, Masayoshi; Onda, Yuichi

    2014-05-01

    Due to Fukushima Daiichi Nuclear Power Plant accident, radioactive materials including Cs-134 and Cs-137 were widely distributed in surrounded area. The radiocesiums have been transported in river networks. This study showed the monitoring results of radiocesium concentration in river waters and suspended sediments in Abukuma river basin and smaller coastal river catchments. The monitoring started at 6 sites from June 2011. Subsequently, additional 24 monitoring sites were installed between October 2012 and January 2013. Flow and turbidity (for calculation of suspended sediment concentration) were measured at each site, while suspended sediments and river water were collected every one or half month to measure Cs-134 and Cs-137 activity concentrations by gamma spectrometry. Activity concentrations of Cs-134 and Cs- 137 on suspended sediments were generally decreasing at all sites. The decreasing rate changed lower at about one year later from the accident. Activity concentration in river waters also showed the same tendency although there are only few data within 1 year from the accident. Activity concentrations measured at the same day are proportional to the mean catchment inventory. Therefore, the activity concentration can be normalized by the mean catchment inventory. The normalized activity can be fitted to following double exponential function: [At] = 1.551 exp (-5.265t) + 0.069 exp (-0.266 t), where t [year] is the time from the accident. There is no time evolution of Kd between suspended sediments and river water. Instead, Kd was varied spatially. Although the reason of the spatial variation is not clear for now, geology of the catchment (i.e. mineral composition of suspended particles) seems to relate to the variation.

  10. Land use/land cover change and implications for ecosystems services in the Likangala River Catchment, Malawi

    Science.gov (United States)

    Pullanikkatil, Deepa; Palamuleni, Lobina G.; Ruhiiga, Tabukeli M.

    2016-06-01

    Likangala River catchment in Zomba District of Southern Malawi is important for water resources, agriculture and provides many ecosystem services. Provisioning ecosystem services accrued by the populations within the catchment include water, fish, medicinal plants and timber among others. In spite of its importance, the River catchment is under threat from anthropogenic activities and land use change. This paper studies land uses and land cover change in the catchment and how the changes have impacted on the ecosystem services. Landsat 5 and 8 images (1984, 1994, 2005 and 2013) were used to map land cover change and subsequent inventorying of provisioning ecosystem services. Participatory Geographic Information Systems and Focus group discussions were conducted to identify provisioning ecosystems services that communities benefit from the catchment and indicate these on the map. Post classification comparisons indicate that since 1984, there has been a decline in woodlands from 135.3 km2 in 1984 to 15.5 km2 in 2013 while urban areas increased from 9.8 km2 to 23.8 km2 in 2013. Communities indicated that provisioning ecosystems services such as forest products, wild animals and fruits and medicinal plants have been declining over the years. In addition, evidence of catchment degradation through waste disposal, illegal sand mining, deforestation and farming on marginal lands were observed. Population growth, urbanization and demand for agricultural lands have contributed to this land use and land cover change. The study suggests addressing catchment degradation through integrated method where an ecosystems approach is used. Thus, both the proximate and underlying driving factors of land-use and land cover change need to be addressed in order to sustainably reduce ecosystem degradation.

  11. Performance of a coupled lagged ensemble weather and river runoff prediction model system for the Alpine Ammer River catchment

    Science.gov (United States)

    Smiatek, G.; Kunstmann, H.; Werhahn, J.

    2012-04-01

    The Ammer River catchment located in the Bavarian Ammergau Alps and alpine forelands, Germany, represents with elevations reaching 2185 m and annual mean precipitation between1100 and 2000 mm a very demanding test ground for a river runoff prediction system. Large flooding events in 1999 and 2005 motivated the development of a physically based prediction tool in this area. Such a tool is the coupled high resolution numerical weather and river runoff forecasting system AM-POE that is being studied in several configurations in various experiments starting from the year 2005. Corner stones of the coupled system are the hydrological water balance model WaSiM-ETH run at 100 m grid resolution, the numerical weather prediction model (NWP) MM5 driven at 3.5 km grid cell resolution and the Perl Object Environment (POE) framework. POE implements the input data download from various sources, the input data provision via SOAP based WEB services as well as the runs of the hydrology model both with observed and with NWP predicted meteorology input. The one way coupled system utilizes a lagged ensemble prediction system (EPS) taking into account combination of recent and previous NWP forecasts. Results obtained in the years 2005-2011 reveal that river runoff simulations depict high correlation with observed runoff when driven with monitored observations in hindcast experiments. The ability to runoff forecasts is depending on lead times in the lagged ensemble prediction and shows still limitations resulting from errors in timing and total amount of the predicted precipitation in the complex mountainous area. The presentation describes the system implementation, and demonstrates the application of the POE framework in networking, distributed computing and in the setup of various experiments as well as long term results of the system application in the years 2005 - 2011.

  12. Environmental flows allocation in river basins: Exploring allocation challenges and options in the Great Ruaha River catchment in Tanzania

    Science.gov (United States)

    Kashaigili, Japhet J.; Kadigi, Reuben M. J.; Lankford, Bruce A.; Mahoo, Henry F.; Mashauri, Damus A.

    Provision for environmental flows is currently becoming a central issue in the debate of integrated water resources management in river basins. However, the theories, concepts and practical applications are still new in most developing countries with challenging situations arising in complex basins with multiple water uses and users and increasing water demands and conflicts exemplified by the Great Ruaha River catchment in Tanzania. The research has shown that a flow of 0.5-1 m 3/s for Great Ruaha River through the Ruaha National Park is required to sustain the environment in the park during the dry season. But a question is how can this be achieved? This paper reviews the challenges and suggests some options for achieving environmental water allocation in river basins. The following challenges are identified: (a) the concept of environmental flows is still new and not well known, (b) there is limited data and understanding of the hydrologic and ecological linkages, (c) there is insufficient specialist knowledge and legislative support, (d) there are no storage reservoirs for controlled environmental water releases, and (e) there are contradicting policies and institutions on environmental issues. Notwithstanding these challenges, this paper identifies the options towards meeting environmental water allocation and management: (a) conducting purposive training and awareness creation to communities, politicians, government officials and decision makers on environmental flows, (b) capacity building in environmental flows and setting-up multidisciplinary environmental flows team with stakeholders involvement, (c) facilitating the development of effective local institutions supported by legislation, (d) water harvesting and storage and proportional flow structures design to allow water for the environment, and (e) harmonizing policies and reform in water utilization and water rights to accommodate and ensure water for the environment.

  13. Pattern of Landslide Distribution Reflects Degree of Hillslope Adjustment in a Waipaoa River Catchment, New Zealand

    Science.gov (United States)

    Cerovski-Darriau, C.; Roering, J. J.

    2014-12-01

    Using landslide morphology to determine the state of hillslope transience provides a diagnostic tool to identify the extent of landscape adjustment. Here we test for a temporal and spatial progression of landslides reflecting the degree of adjustment for a Waipaoa River catchment (North Island, New Zealand). Following the shift to a warmer, wetter climate after the Last Glacial Maximum (LGM) (~18 ka), the Waipaoa River rapidly incised up to 120 m, leaving perched, low-relief hillslopes unadjusted to that base level fall. In the 16 km2 study catchment—principally comprised of weak mélange—pervasive post-LGM landslides responded to >50 m of fluvial incision by sculpting and denuding >99% of the catchment, but adjustment is not yet complete. Starting ~150 years ago, European settlers deforested ~95% of the landscape, which triggered a sharp increase in hillslope erosion as widespread earthflow complexes and gully systems reactivated and/or expanded in the weak lithology with the loss of vegetation cover. Most of the remaining relict (≥18 ka) landforms are confined to the upper watershed, upholding the proposed upstream progression of hillslope adjustment. Based on previous tephrochronology and surface roughness data, present-day earthflows follow this pattern of younging upstream. Here we analyze the size, location, and distribution of ~500 earthflows (mapped from 2010 lidar and orthophotos) to determine if there is a spatial progression of earthflows reflective of hillslope adjustment and correlated to the previously identified temporal progression. Morphologic evidence from this study indicates the younger earthflows in the upper watershed have smaller areas (6000 ± 600 m2 (mean ± s.e.)), a more elongate aspect ratio (AR=3.6 ± 1.6 (mean ± s.d.)), and are generally (>50%) deposited in axial gullies, whereas downstream earthflows are larger (20000 ± 9000 m2), statistically less elongate (AR=2.3 ± 0.9), and more frequently coupled with the main channel

  14. Persistent pollution of Warta river catchment with chromium: case study from central Poland

    Science.gov (United States)

    Hermanski, S.; Lukaczynski, I.; Nikiel, G.; Mizera, J.; Dulinski, M.; Kania, J.; Rozanski, K.; Szklarczyk, T.; Wachniew, P.; Witczak, S.; Zurek, A.

    2012-04-01

    Upper reaches of the Warta river, the third largest river in Poland, are located in a densely populated and industrialized area, with presence of heavy industry going back to the second half of the XIX century. Industrial activities include iron smelters in towns of Częstochowa and Zawiercie, large chemical plants (Rudniki and Aniolow) producing predominantly chromium compounds, paper and textile industry, as well as large number of small enterprises specialized in metal coatings (nickel and chromium). Until the 1960s all the industrial and municipal effluents in the region were discharged into the Warta river and its tributaries. Solid wastes were dumped on the surface, mostly without appropriate cover and isolation. This resulted in progressive contamination of surface waters and groundwater with heavy metals, mostly chromium. The upper reaches of the Warta river are located on top of upper Jurassic Major Groundwater Basin (MGWB 326 which is one of four most important groundwater reservoirs in Poland. Almost all potable water demands in the area (ca. 340,000 inhabitants, 800 factories and enterprises) are covered by MGWB 326 (50 deep wells with the average extraction rate of 57,000 m3/d). As the MGWB 326 is mostly phreatic, it has been recognized since long time that persistent pollution of the upper catchment of the Warta river with heavy metals may pose serious thread to quality of this important groundwater resource. In this presentation we summarize the work carried out to date, focused on characterization of the extent and understanding of the mechanisms of pollution of surface water, sediments and groundwater in MGWB 326 with chromium. Historical monitoring data of the levels of chromium in the Warta river and its tributaries are presented, supplemented by the results of measurements of Cr loads in Warta over-bank deposits and Cr levels in groundwater production wells in the area. Three conceptual models of spreading of chromium in the catchment of Warta

  15. Rainfall-runoff model for prediction of waterborne viral contamination in a small river catchment

    Science.gov (United States)

    Gelati, E.; Dommar, C.; Lowe, R.; Polcher, J.; Rodó, X.

    2013-12-01

    We present a lumped rainfall-runoff model aimed at providing useful information for the prediction of waterborne viral contamination in small rivers. Viral contamination of water bodies may occur because of the discharge of sewage effluents and of surface runoff over areas affected by animal waste loads. Surface runoff is caused by precipitation that cannot infiltrate due to its intensity and to antecedent soil water content. It may transport animal feces to adjacent water bodies and cause viral contamination. We model streamflow by separating it into two components: subsurface flow, which is produced by infiltrated precipitation; and surface runoff. The model estimates infiltrated and non-infiltrated precipitation and uses impulse-response functions to compute the corresponding fractions of streamflow. The developed methodologies are applied to the Glafkos river, whose catchment extends for 102 km2 and includes the city of Patra. Streamflow and precipitation observations are available at a daily time resolution. Waterborne virus concentration measurements were performed approximately every second week from the beginning of 2011 to mid 2012. Samples were taken at several locations: in river water upstream of Patras and in the urban area; in sea water at the river outlet and approximately 2 km south-west of Patras; in sewage effluents before and after treatment. The rainfall-runoff model was calibrated and validated using observed streamflow and precipitation data. The model contribution to waterborne viral contamination prediction was benchmarked by analyzing the virus concentration measurements together with the estimated surface runoff values. The presented methodology may be a first step towards the development of waterborne viral contamination alert systems. Predicting viral contamination of water bodies would benefit sectors such as water supply and tourism.

  16. Aquifer responses to climate anomalies in the Loddon River catchment, Southeastern Australia

    Science.gov (United States)

    Manamperi, S.; Webb, J.

    2013-12-01

    Numerous studies suggest that climate change will lead to changes in the seasonality of surface water availability, thereby changing the recharge pattern in groundwater aquifers. Climate modelling predicts an increasing trend of extreme events such as floods and droughts in much of Southeastern Australia in the future. The present study provides a long-term compilation and analysis of the water table response to the last 30 years of climate in the Loddon River catchment, southeastern Australia, in order to evaluate the underlying mechanisms, and determine the response of the Loddon aquifers to past and future climate variability. There are three main aquifers in the catchment (Newer Volcanics, Shepparton Formation and Calivil Formation, in stratigraphic order). Using 215 groundwater monitoring bores with 10 or more years of data, coupled with 8 stream gauges and 8 rainfall gauging stations, several statistical analyses were performed. The monitoring bore data was used to define 7 different hydrogeomorphic units based on topography and aquifer characteristics. Groundwater trends were calculated as normalized anomalies (difference from the mean / standard deviation) and compared to regional rainfall and stream flow anomalies, to understand the sensitivity of the aquifer systems to change. Changes in groundwater storage during the periods that show a significantly high anomaly were calculated using the water level fluctuation method. Results suggest that, regionally, the Loddon aquifers respond strongly to episodic flooding events and decade-long droughts. The highest anomalies in each data set were observed during 2010/11, the highest recorded river flow and rainfall in the last 30 years, accompanied by extensive flooding in the Lower Loddon. However, the aquifers in the Lower Loddon show diverse trends in water level response to this event. The shallow Shepparton Formation aquifer showed a rapid response to flooding with a decreasing trend after few months, whereas

  17. Water Quality Changes during Rapid Urbanization in the Shenzhen River Catchment: An Integrated View of Socio-Economic and Infrastructure Development

    OpenAIRE

    Hua-peng Qin; Qiong Su; Soon-Thiam Khu; Nv Tang

    2014-01-01

    Surface water quality deterioration is a serious problem in many rapidly urbanizing catchments in developing countries. There is currently a lack of studies that quantify water quality variation (deterioration or otherwise) due to both socio-economic and infrastructure development in a catchment. This paper investigates the causes of water quality changes over the rapid urbanization period of 1985–2009 in the Shenzhen River catchment, China and examines the changes in relation to infrastructu...

  18. Maixi River estuary to the Baihua Reservoir in the Maotiao River catchment: phytoplankton community and environmental factors

    Institute of Scientific and Technical Information of China (English)

    LI Qiuhua; CHEN Lili; CHEN Fengfeng; GAO Tingjin; LI Xiaofeng; LIU Songping; LI Cunxiong

    2013-01-01

    Phytoplankton and environmental variables were measured monthly from July 2009 to August 2011 in the Maixi River from the estuary to Baihua Reservoir in the Maotiao River catchment,southwestern China,to understand phytoplankton community structure and environmental factors.The relationship between phytoplankton community structure and environmental factors including hydrological,meteorological,physical,and chemical variables were explored using multivariate analysis.A total of 81taxa of phytoplankton were identified,which were mainly composed of chlorophyta,bacillariophyta,and cyanobacteria.The phytoplankton community was dominated by Pseudanabaena limnetica during summer and fall and by Cyclotella meneghiniana during winter and spring.The abundance of phytoplankton ranged from 0.24×104 cells/L to 33.45×i06 cells/L,with the minimum occurring during February 2010 and the maximum during July 2009.The phytoplankton community was dominated mainly by cyanobacteria from April to September,and by bacillariophyta and pyrrophyta from October to March.Canonical correspondence analysis showed that temperature,pH values,and orthophosphate were the most important driving factors regulating the composition and dynamics of the phytoplankton community in the estuary.Cyanobacteria and euglenophyta abundance and biomass were affected mainly by temperature and pH values,while most chlorophyta and bacillariophyta were influenced by the concentrations of nutrients.

  19. Changes of wetland landscape patterns in Dadu River catchment from 1985 to 2000, China

    Institute of Scientific and Technical Information of China (English)

    Laibin HUANG; Junhong BAI; Denghua YAN; Bin CHEN; Rong XIAO; Haifeng GAO

    2012-01-01

    Based on the interpretation and vector processing of remote sensing images in 1985 and 2000,the spatial changes of wetland landscape patterns in Dadu River catchment in the last two decades were studied using spatial analysis method.Supported by Apack software,the indices of wetland landscape pattern were calculated,and the information entropy (IE) was also introduced to show the changes of wetland landscape information.Results showed that wetland landscape in this region was characteristic of patch-corridor-matrix configuration and dominantly consisted of natural wetlands.Landscape patterns changed a little with low fragment and showed concentrated distribution with partial scattered distribution during the period from 1985 to 2000.The values of patch density and convergence index kept stable,and the values of diversity,evenness indices and IE showed a slight decrease,while dominance and fractal dimension indices were increased.All types of wetland landscapes had higher adjacency probabilities with grassland landscape in 1985 and 2000,and there was extremely weak hydrological link and large spatial gap among river,glacier,reservoir and pond wetlands due to low adjacency matrix values.Since their cumulative contribution exceeded 81% through the PCA analysis,the agriculture activities would be the main driving force to the landscape changes during the past 15 years.

  20. Linking coral river runoff proxies with climate variability, hydrology and land-use in Madagascar catchments.

    Science.gov (United States)

    Maina, Joseph; de Moel, Hans; Vermaat, Jan E; Bruggemann, J Henrich; Guillaume, Mireille M M; Grove, Craig A; Madin, Joshua S; Mertz-Kraus, Regina; Zinke, Jens

    2012-10-01

    Understanding the linkages between coastal watersheds and adjacent coral reefs is expected to lead to better coral reef conservation strategies. Our study aims to examine the main predictors of environmental proxies recorded in near shore corals and therefore how linked near shore reefs are to the catchment physical processes. To achieve these, we developed models to simulate hydrology of two watersheds in Madagascar. We examined relationships between environmental proxies derived from massive Porites spp. coral cores (spectral luminescence and barium/calcium ratios), and corresponding time-series (1950-2006) data of hydrology, climate, land use and human population growth. Results suggest regional differences in the main environmental drivers of reef sedimentation: on annual time-scales, precipitation, river flow and sediment load explained the variability in coral proxies of river discharge for the northeast region, while El Niño-Southern Oscillation (ENSO) and temperature (air and sea surface) were the best predictors in the southwest region. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Occurrence of priority organic pollutants in Strymon river catchment, Greece: inland, transitional, and coastal waters.

    Science.gov (United States)

    Litskas, V D; Dosis, I G; Karamanlis, X N; Kamarianos, A P

    2012-09-01

    Twenty-five sampling stations were selected in order to monitor persistent organic pollutants (polycyclic aromatic hydrocarbons (PAHs), organochlorine (OC) pesticides and total polychlorinated biphenyls (PCBs)) in surface water from Kerkini Lake, the Strymon River, its main tributaries and estuary in N. Aegean Sea during January to July, 2008, according to recent European Union (EU) guidelines. The data were divided among the high (January to April) and the low flow season (May to July). Generally, the values for organic pollutants were within the range reported worldwide for surface water. Elevated PAHs concentrations were observed compared with other places in Greece. Anthracene and benzo(a)pyrene exceeded maximum allowable concentration (MAC) of the relative EU guideline. Also, concentrations above MAC were observed for OCs, γ-HCH, and a-endosulfan. Despite the fact that it is banned since 1972, Aldrin was detected during the monitoring season (from limit of detection (LOD) to 15 ng L(-1)). Total PCB concentrations ranged from LOD to 162 ng L(-1). In addition, the load of organic pollutants was estimated in April (high flow) and June (low flow) in selected sampling stations. According to this estimation, napthalene, anthracene, and fluoranthene (PAHs), total dichlorodiphenyltrichloroethane (DDT), aldrin, and total PCBs had the highest load. Taking into account the relative EU guidelines concerning the pollutants studied, the water quality in the Strymon River catchment could be characterized as poor, which can lead to negative impacts to its biota.

  2. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: Base-Flow Index, 2002

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This tabular data set represents the mean base-flow index expressed as a percent, compiled for every catchment of MRB_E2RF1 catchments of Major River Basins (MRBs,...

  3. Projected changes in soil organic carbon stocks upon adoption of recommended soil and water conservation practices in the upper Tana river catchment, Kenya

    NARCIS (Netherlands)

    Batjes, N.H.

    2014-01-01

    Large areas in the Upper Tana river catchment, Kenya, have been over-exploited, resulting in soil erosion, nutrient depletion and loss of soil organic matter (SOM). This study focuses on sections of the catchment earmarked as being most promising for implementing Green Water Credits, an incentive

  4. Multiple plant-wax compounds record differential sources and ecosystem structure in large river catchments

    Science.gov (United States)

    Hemingway, Jordon D.; Schefuß, Enno; Dinga, Bienvenu Jean; Pryer, Helena; Galy, Valier V.

    2016-07-01

    n-alkanes better represent a catchment-integrated signal with minimal response to discharge seasonality. Comparison to published data on other large watersheds indicates that this phenomenon is not limited to the Congo River, and that analysis of multiple plant-wax lipid classes and chain lengths can be used to better resolve local vs. distal ecosystem structure in river catchments.

  5. Stable oxygen isotope variability in two contrasting glacier river catchments in Greenland

    Science.gov (United States)

    Yde, Jacob C.; Knudsen, Niels T.; Steffensen, Jørgen P.; Carrivick, Jonathan L.; Hasholt, Bent; Ingeman-Nielsen, Thomas; Kronborg, Christian; Larsen, Nicolaj K.; Mernild, Sebastian H.; Oerter, Hans; Roberts, David H.; Russell, Andrew J.

    2016-03-01

    Analysis of stable oxygen isotope (δ18O) characteristics is a useful tool to investigate water provenance in glacier river systems. In order to attain knowledge on the diversity of δ18O variations in Greenlandic rivers, we examined two contrasting glacierised catchments disconnected from the Greenland Ice Sheet (GrIS). At the Mittivakkat Gletscher river, a small river draining a local temperate glacier in southeast Greenland, diurnal oscillations in δ18O occurred with a 3 h time lag to the diurnal oscillations in run-off. The mean annual δ18O was -14.68 ± 0.18 ‰ during the peak flow period. A hydrograph separation analysis revealed that the ice melt component constituted 82 ± 5 % of the total run-off and dominated the observed variations during peak flow in August 2004. The snowmelt component peaked between 10:00 and 13:00 local time, reflecting the long travel time and an inefficient distributed subglacial drainage network in the upper part of the glacier. At the Kuannersuit Glacier river on the island Qeqertarsuaq in west Greenland, the δ18O characteristics were examined after the major 1995-1998 glacier surge event. The mean annual δ18O was -19.47 ± 0.55 ‰. Despite large spatial variations in the δ18O values of glacier ice on the newly formed glacier tongue, there were no diurnal oscillations in the bulk meltwater emanating from the glacier in the post-surge years. This is likely a consequence of a tortuous subglacial drainage system consisting of linked cavities, which formed during the surge event. Overall, a comparison of the δ18O compositions from glacial river water in Greenland shows distinct differences between water draining local glaciers and ice caps (between -23.0 and -13.7 ‰) and the GrIS (between -29.9 and -23.2 ‰). This study demonstrates that water isotope analyses can be used to obtain important information on water sources and the subglacial drainage system structure that is highly desired for understanding glacier hydrology.

  6. Spatial distribution of electrical conductivity and stable isotopes in groundwater in large catchments: a geostatistical approach in the Quequén Grande River catchment, Argentina.

    Science.gov (United States)

    Quiroz Londoño, Orlando Mauricio; Martínez, Daniel Emilio; Massone, Hector Enrique; Londoño Ciro, Libardo Antonio; Dapeña, Cristina

    2015-01-01

    Stable isotopes and electrical conductivity in groundwater were used as natural tracers to adjust the hydrogeological conceptual model in one of the largest catchments within the inter-mountainous Pampa plain, Argentina. Geostatistical tools were used to define the model that best fitted the spatial distribution of each tracer, and information was obtained in areas where there was a lack of data. The conventional isotopic analysis allowed the identification of three groundwater groups with different isotopic fingerprints. One group containing 56% of the total groundwater samples suggested a well-mixed system and soil infiltration precipitation as the main recharge source to the aquifer. The other two groups included samples with depleted (25.5%) and enriched (18.5%) isotopic compositions, respectively. The combination of δ(18)O, δ(2)H and electrical conductivities maps suggested ascending regional flows and water transfer from the Quequén Grande River catchment to the Moro creek. The spatial interpretation of these tracers modified the conceptual hydrogeological model of the Quequén Grande River.

  7. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: Mean Annual R-factor, 1971-2000

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This tabular data set represents the average annual R-factor, rainfall-runoff erosivity measure, compiled for every MRB_E2RF1 catchment of selected Major River...

  8. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: STATSGO Soil Characteristics

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This tabular data set represents estimated soil variables compiled for every MRB_E2RF1 catchment of selected Major River Basins (MRBs, Crawford and others, 2006)....

  9. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: Basin Characteristics, 2002

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This tabular data set represents basin characteristics for the year 2002 compiled for every MRB_E2RF1 catchment of selected Major River Basins (MRBs, Crawford and...

  10. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: Hydrologic Landscape Regions

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This tabular data set represents the area of Hydrologic Landscape Regions (HLR) compiled for every MRB_E2RF1 catchment of the Major River Basins (MRBs, Crawford and...

  11. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: Estimated Mean Annual Natural Groundwater Recharge, 2002

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This tabular data set represents the mean annual natural groundwater recharge, in millimeters, compiled for every MRB_E2RF1catchment of selected Major River Basins...

  12. Land degradation trends in upper catchments and morphological developments of braided rivers in drylands: the case of a marginal graben of the Ethiopian Rift Valley

    Science.gov (United States)

    Demissie, Biadgilgn; Frankl, Amaury; Haile, Mitiku; Nyssen, Jan

    2014-05-01

    Braided rivers have received relatively little attention in research and development activities in drylands. However, they strongly impact agroecology and agricultural activities and thereby local livelihoods. The Raya Graben (3750 km² including the escarpment) is a marginal graben of the Ethiopian Rift Valley located in North Ethiopia. In order to study the dynamics of braided rivers and the relationship with biophysical controls, 20 representative catchments were selected, ranging between 15 and 311 km². First, the 2005 morphology (length, area) of the braided rivers was related to biophysical controls (vegetation cover, catchment area and slope gradient in the steep upper catchments and gradient in the graben bottom). Second, the changes in length of the braided rivers were related to vegetation cover changes in the upper catchments since 1972. Landsat imagery was used to calculate the Normalized Difference Vegetation Index (NDVI), and to map vegetation cover and the total length of the braided rivers. Spot CNES imagery available from Google Earth was used to identify the total area of the braided rivers in 2005. A linear regression analysis revealed that the length of braided rivers was positively related to the catchment area (R²=0.32, p<0.01), but insignificantly related to vegetation cover in the upper catchments. However, there is an indication that it is an important factor in the relationship calculated for 2005 (R²=0.2, p=0.064). Similarly, the area occupied by the braided rivers was related to NDVI (R²=0.24, p<0.05) and upper catchment area (R²=0.447, p<0.01). Slope gradient is not an important explanatory factor. This is related to the fact that slope gradients are steep (average of 38.1%) in all upper and gentle (average of 3.4%) in graben bottom catchments. The vegetation cover in the upper catchments shows a statistically insignificant increasing trend (R²=0.73, p=0.067) over the last 40 years, whereas length of rivers in the graben bottom

  13. Nitrogen Source Apportionment for the Catchment, Estuary, and Adjacent Coastal Waters of the River Scheldt

    Directory of Open Access Journals (Sweden)

    Jan E. Vermaat

    2012-06-01

    Full Text Available Using the systems approach framework (SAF, a coupled model suite was developed for simulating land-use decision making in response to nutrient abatement costs and water and nutrient fluxes in the hydrological network of the Scheldt River, and nutrient fluxes in the estuary and adjacent coastal sea. The purpose was to assess the efficiency of different long-term water quality improvement measures in current and future climate and societal settings, targeting nitrogen (N load reduction. The spatial-dynamic model suite consists of two dynamically linked modules: PCRaster is used for the drainage network and is combined with ExtendSim modules for farming decision making and estuarine N dispersal. Model predictions of annual mean flow and total N concentrations compared well with data available for river and estuary (r² ≥ 0.83. Source apportionment was carried out to societal sectors and administrative regions; both households and agriculture are the major sources of N, with the regions of Flanders and Wallonia contributing most. Load reductions by different measures implemented in the model were comparable (~75% remaining after 30 yr, but costs differed greatly. Increasing domestic sewage connectivity was more effective, at comparatively low cost (47% remaining. The two climate scenarios did not lead to major differences in load compared with the business-as-usual scenario (~88% remaining. Thus, this spatially explicit model of water flow and N fluxes in the Scheldt catchment can be used to compare different long-term policy options for N load reduction to river, estuary, and receiving sea in terms of their effectiveness, cost, and optimal location of implementation.

  14. The role of a dambo in the hydrology of a catchment and the river network downstream

    Directory of Open Access Journals (Sweden)

    C. J. von der Heyden

    2003-01-01

    Full Text Available Dambos are shallow, seasonally inundated wetlands and are a widespread landform in Central and Southern Africa. Owing to their importance in local agriculture and as a water resource, the hydrology of dambos is of considerable interest: varied, and sometimes contradictory, hydrological characteristics have been described in the literature. The issues in contention focus on the role of the dambo in (i the catchment evapotranspiration (ET budget, (ii flood flow retardation and attenuation, and (iii sustaining dry season flow to the river down-stream. In addition, both rainfall and groundwater have been identified as the dominant source of water to the dambo and various hydrogeological models have been proposed to describe the hydrological functions of the landform. In this paper, hydrological and geochemical data collected over a full hydrological year are used to investigate and describe the hydrological functions of a dambo in north-western Zambia. The Penman estimate of wetland ET was less than the ET from the miombo-wooded interfluve and the wetland has been shown to have little effect on flood flow retardation or attenuation. Discharge of water stored within the wetland contributed little to the dry season flow from the dambo, which was sustained primarily by groundwater discharge. Flow in a perched aquifer within the catchment soils contributed a large portion of baseflow during the rains and early dry season. This source ceased by the mid dry season, implying that the sustained middle to late dry season streamflow from the wetland is through discharge of a deeper aquifer within the underlying regolith or bedrock. This hypothesis is tested through an analysis of groundwater and wetland geochemistry. Various physical parameters, PHREEQC model results and end member mixing analysis (EMMA suggest strongly that the deep Upper Roan dolomite aquifer is the source of sustained discharge from the wetland. Keywords: dambo, hydrology, hydrogeology

  15. Estimation of sediment residence times in subtropical highland catchments of central Mexico combining river gauging and fallout radionuclides

    Science.gov (United States)

    Evrard, Olivier; Némery, Julien; Gratiot, Nicolas; Duvert, Clément; Lefèvre, Irène; Ayrault, Sophie; Esteves, Michel; Bonté, Philippe

    2010-05-01

    Subtropical regions of the world are affected by intense soil erosion associated with deforestation, overgrazing and cropping intensification. This land degradation leads to important on-site (e.g. decrease in soil fertility) and off-site impacts (e.g. reservoir sedimentation, water pollution). This study determined the mean sediment residence times in soils and rivers of three catchments (3 - 12 km²) with contrasted land uses (i.e. cropland, forests, rangelands, extended gully networks) located in highlands of the transvolcanic belt of central Mexico. Calculations were based on rainfall and river gauging as well as on fallout radionuclide measurements (Be-7, Cs-137, Pb-210). Atmospheric deposition of Be-7 and Pb-210 was estimated based on the analysis of rainfall precipitated samples. Rainfall samples were collected all throughout the rainy season in order to take account of the temporal variations of the radionuclide fluxes. Furthermore, sampling of suspended sediment was conducted at the outlet of each catchment during most of the storms that occurred throughout the 2009 rainy season. Be-7, Cs-137 and Pb-210 concentrations of this sediment were determined by gamma-spectrometry. A two-box balance model was then used to estimate the sediment residence time and the inventory of radionuclides in the three selected catchments. This model subdivided each catchment into two boxes: (i) a "soil-box" characterised by low transport velocities and hence long radionuclide residence times and (ii) a "river-box" covering the river surface and its surroundings characterised by quicker exchanges and shorter radionuclide residence times. Input and output fluxes of sediment and radionuclides were taken into account in each box. Radioactive decay during the residence time of sediment was also considered. The mean residence time of sediment in soils ranged between 13,300 - 28,500 years. In contrast, sediment residence time in rivers was much shorter, fluctuating between 28 and 393

  16. Geo-referenced modelling of metal concentrations in river basins at the catchment scale

    Science.gov (United States)

    Hüffmeyer, N.; Berlekamp, J.; Klasmeier, J.

    2009-04-01

    1. Introduction The European Water Framework Directive demands the good ecological and chemical state of surface waters [1]. This implies the reduction of unwanted metal concentrations in surface waters. To define reasonable environmental target values and to develop promising mitigation strategies a detailed exposure assessment is required. This includes the identification of emission sources and the evaluation of their effect on local and regional surface water concentrations. Point source emissions via municipal or industrial wastewater that collect metal loads from a wide variety of applications and products are important anthropogenic pathways into receiving waters. Natural background and historical influences from ore-mining activities may be another important factor. Non-point emissions occur via surface runoff and erosion from drained land area. Besides deposition metals can be deposited by fertilizer application or the use of metal products such as wires or metal fences. Surface water concentrations vary according to the emission strength of sources located nearby and upstream of the considered location. A direct link between specific emission sources and pathways on the one hand and observed concentrations can hardly be established by monitoring alone. Geo-referenced models such as GREAT-ER (Geo-referenced Regional Exposure Assessment Tool for European Rivers) deliver spatially resolved concentrations in a whole river basin and allow for evaluating the causal relationship between specific emissions and resulting concentrations. This study summarizes the results of investigations for the metals zinc and copper in three German catchments. 2. The model GREAT-ER The geo-referenced model GREAT-ER has originally been developed to simulate and assess chemical burden of European river systems from multiple emission sources [2]. Emission loads from private households and rainwater runoff are individually estimated based on average consumption figures, runoff rates

  17. Decreasing Reference Evapotranspiration in a Warming Climate——A Case of Changjiang (Yangtze) River Catchment During 1970-2000

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This study deals with temporal trends in the Penman-Monteith reference evapotranspiration estimated from standard meteorological observations, observed pan evaporation, and four related meteorological variables during 1970-2000 in the Yangtze River catchment. Relative contributions of the four meteorological variables to changes in the reference evapotranspiration are quantified. The results show that both the reference evapotranspiration and the pan evaporation have significant decreasing trends in the upper, the middle as well as in the whole Changjiang (Yangtze) River catchment at the 5% significance level, while the air temperature shows a significant increasing trend. The decreasing trend detected in the reference evapotranspiration can be attributed to the significant decreasing trends in the net radiation and the wind speed.

  18. A meteo-hydrological modeling study for flood events in the Ofanto river catchment

    Science.gov (United States)

    Verri, Giorgia; Pinardi, Nadia; Tribbia, Joseph; Gochis, David; Navarra, Antonio; Coppini, Giovanni; Vukicevic, Tomislava

    2016-04-01

    The aim of this study is to evaluate the capability of our meteo-hydrological modeling system to simulate the local water cycle of the Ofanto river catchment. The basin of the Ofanto River, flowing through the Southern Italy and ending into the Adriatic Sea, is chosen as a challenging case study to test the modeling chain since the Southern Italy is known to be a region subject to flash flood events (Delrieu et al, 2005; Davolio et al, 2008; Miglietta et al., 2008). Moreover the Ofanto River is a semi-perennial river, its annual averaged discharge is low (15 m3s-1following Raicich, 1996) but may significantly increase when heavy rain events occur. We select the first 3 months of 2011 as model time window since 4 heavy rain events characterized this period with flooding of the Ofanto River during two of them. The meteo-hydrological chain consists of: WRF-ARW model (Skamarock et al., 2008) for the atmospheric modeling, NOAH-MP Land Surface Model (Niu et al., 2011) which describes the vertical physics of the soil column up to 1m below the ground-level, and WRF-Hydro model (Gochis D., et al., 2013) which enables to model the lateral soil surface and subsurface water fluxes and is coupled in 1-way mode with WRF and 2way-mode with NOAH-MP. We have assessed which model tunable parameters, numerical choices and forcing data most impact the performance of our integrated modeling system and have determined an optimal set-up of our meteo-hydrological modeling chain that fully captures the observed heavy rain events and the related river floods. The skill was assessed with respect to available observations of precipitation and river runoff relying on more than 100 raingauge stations and 2 hydrological stations along the river network. The sensitivity results show positive impacts of higher resolution and upgraded land use categories, soil types and topography data on hindcast simulations. It is also found that the tunable parameters of soil infiltration, conductivity and deep

  19. Multifaceted Value Profiles of Forest Owner Categories in South Sweden: The River Helge å Catchment as a Case Study

    OpenAIRE

    Richnau, Gustav; Angelstam, Per; Valasiuk, Sviataslau; Zahvoyska, Lyudmyla; Axelsson, Robert; Elbakidze, Marine; Farley, Joshua; Jönsson, Ingemar; Soloviy, Ihor

    2013-01-01

    Forest landscapes provide benefits from a wide range of goods, function and intangible values. But what are different forest owner categories’ profiles of economic use and non-use values? This study focuses on the complex forest ownership pattern of the River Helge å catchment including the Kristianstad Vattenrike Biosphere Reserve in southern Sweden. We made 89 telephone interviews with informants representing the four main forest owner categories. Our mapping included consumptive and non-co...

  20. Efficiency analysis of Policies against desertification by applying DEA: a case study in the river Guadalentin catchment (Almeria, Spain)

    OpenAIRE

    2010-01-01

    This paper deals about an attempt to evaluate the different policies against desertification carried out during a twenty five year period (1978-2003) in the eight municipalities which compound the river Guadalentín catchment (Murcia, Spain). The approach is based on DEA and the European Environmental Agency indicator studies, the former to measure the efficiency and the second to select the best environmental indicators. The analysis has been reiterated with three different sets of outputs re...

  1. Pollution from urban development and setback outfalls as a catchment management measure for river water quality improvement

    Science.gov (United States)

    Allen, Deonie; Haynes, Heather; Arthur, Scott

    2016-04-01

    Urban development causes an increase in fine sediment and heavy metal stormwater pollution. Pollution load estimation theorises that stormwater pollutant load and type are strongly, directly influenced by contributing catchment land use. The research presented investigates the validity of these assumptions using an extensive novel field data set of 53 catchments. This research has investigated the relationships between land use and pollutant concentrations (Cu, Zn, Pb, Ni, Ca, Ba, Sn, Mn) in urban stormwater outfall sediments. Cartographic and aerial photography data have been utilised to delineate the surface and subsurface contributing catchment land use. A zoned sub-catchment approach to catchment characterisation of stormwater pollutant concentration has been defined and tested. This method effectively describes the specific land use influence on pollutant concentrations at the stormwater outfall, showing strong dependency with road length, brake points, impervious area and open space. Road networks and open space are found to influence land use, and thus stormwater pollution, closer to stormwater outfall/receiving waterbody suggesting storage, treatment, assimilation, loss or dilution of the land use influence further away from stormwater outfall. An empirical description has been proposed with which to predict outfall pollutant contributions to the receiving urban waterbody based on catchment land use information. With the definition and quantification of contributing catchment specific fine sediment and urban heavy metal pollutants, the influence of urban stormwater outfall management on the receiving watercourse has been considered. The locations of stormwater outfalls, and their proximity to the receiving waterway, are known as key water quality and river health influences. Water quality benefits from the implementation of stormwater outfalls set back from the receiving waterway banks have been investigated using the catchment case study. Setback outfalls

  2. Response of surface and groundwater on meteorological drought in Topla River catchment, Slovakia

    Science.gov (United States)

    Fendekova, Miriam; Fendek, Marian; Vrablikova, Dana; Blaskovicova, Lotta; Slivova, Valeria; Horvat, Oliver

    2016-04-01

    Continuously increasing number of drought studies published in scientific journals reflects the attention of the scientific community paid to drought. The fundamental works among many others were published by Yevjevich (1967), Zelenhasic and Salvai (1987), later by Tallaksen and van Lanen Eds. (2004). The aim of the paper was to analyze the response of surface and groundwater to meteorological drought occurrence in the upper and middle part of the Topla River Basin, Slovakia. This catchment belongs to catchments with unfavourable hydrogeological conditions, being built of rocks with quite low permeability. The basin is located in the north-eastern part of Slovakia covering the area of 1050.05 km2. The response was analyzed using precipitation data from the Bardejov station (long-term annual average of 662 mm in 1981 - 2012) and discharge data from two gauging stations - Bardejov and Hanusovce nad Toplou. Data on groundwater head from eight observation wells, located in the catchment, were also used, covering the same observation period. Meteorological drought was estimated using characterisation of the year humidity and SPI index. Hydrological drought was evaluated using the threshold level method and method of sequent peak algorithm, both with the fixed and also variable thresholds. The centroid method of the cluster analysis with the squared Euclidean distance was used for clustering data according to occurrence of drought periods, lasting for 100 days and more. Results of the SPI index showed very good applicability for drought periods identification in the basin. The most pronounced dry periods occurred in 1982 - 1983, 1984, 1998 and 2012 being classified as moderately dry, and also in 1993 - 1994, 2003 - 2004 and 2007 evolving from moderately to severely dry years. Short-term drought prevailed in discharges, only three periods of drought longer than 100 days occurred during the evaluated period in 1986 - 1987, 1997 and 2003 - 2004. Discharge drought in the

  3. Participatory planning in river catchments, an innovative toolkit tested in Southern Africa and North West England.

    Science.gov (United States)

    Tippett, J

    2005-01-01

    The European Union Water Framework Directive (WFD) offers an unparalleled opportunity for improving river basin management. Active participation is essential for its delivery. "End-of-pipe" solutions will not deliver the improvements needed to achieve its ambitious goals. This research tested DesignWays, a toolkit for participatory planning, as a mechanism for maximizing the long-term social and environmental benefits of such stakeholder and community participation. It examined the emerging role of "planning for sustainability" in the context of river catchments. Sustainable management of water requires integration, and recognition of interconnections between systems at different levels of scale. This is an endeavour in which systems thinking provides useful tools. The development of DesignWays was a conscious attempt to embed 'new paradigm' living systems metaphors into a practical planning tool. This paper begins with a description of DesignWays and its development in Southern Africa. An outline of the context of the action research in North-West England is followed by a description of the stages of the process, with highlights of the outcomes. This research had two major outcomes: a contribution to theory through an in-depth exploration of the theoretical basis of participatory, ecologically informed design; and a contribution to practice through investigating DesignWays' potential to meet key challenges of the WFD. This research points to the importance of understanding participatory planning as a societal process, aiming to make the process engaging and meaningful. It has pointed to the need to see participatory planning and education for sustainability as an integrated process. It demonstrated the benefits of an iterative process in which planning at the landscape level of scale informs, and is informed by, work at the site level. It has shown that an approach consistent with a living systems paradigm can contribute to the development of more integrated

  4. Identification of pollutant sources in a rapidly developing urban river catchment in China

    Science.gov (United States)

    Huang, Jingshui; Yin, Hailong; Jomma, Seifeddine; Rode, Michael; Zhou, Qi

    2016-04-01

    Rapid economic development and urbanization worldwide cause serious ecological and environmental problems. A typical region that is in transition and requires systemic research for effective intervention is the rapidly developing city of Hefei in central P. R. China. In order to investigate the sources of pollutants over a one-year period in Nanfei River catchment that drains the city of Hefei, discharges were measured and water samples were taken and measured along the 14km river section at 10 sites for 4 times from 2013 to 2014. Overflow concentrations of combined sewer and separate storm drains were also measured by selecting 15 rain events in 4 typical drainage systems. Loads and budgets of water and different pollutant sources i.e., wastewater treatment plant (WWTP) effluent, urban drainage overflow, unknown wastewater were calculated. The water balance demonstrated that >70% of the discharge originated from WWTP effluent. Lack of clean upstream inflow thereby is threatening ecological safety and water quality. Furthermore, mass fluxes calculations revealed that >40% of the COD (Chemical Oxygen Demand) loads were from urban drainage overflow because of a large amount of discharge of untreated wastewater in pumping stations during rain events. WWTP effluent was the predominant source of the total nitrogen loads (>60%) and ammonia loads (>45%). However, the total phosphorous loads from three different sources are similar (˜1/3). Thus, our research provided a basis for appropriate and prior mitigation strategies (state-of-art of WWTP upgrade, sewer systems modification, storm water regulation and storage capacity improvement, etc.) for different precedence-controlled pollutants with the limited infrastructure investments in these rapidly developing urban regions.

  5. Pilot implementation of WFD and creation of a tool for catchment management using SWAT: River Zglowiaczka Catchment, Poland

    Institute of Scientific and Technical Information of China (English)

    M.(S)MIETANKA; J.BRZOZOWSKI; D.(S)LIWI(N)SKI; K.SMARZY(N)SKA; Z.MIATKOWSKI; M.KALARUS

    2009-01-01

    Poland, like other EU countries, is obliged to implement the Water Framework Directive (2000/60/WE) by the end of 2015. The main objective of the Directive is to provide normative quality of all water resources (surface, underground and coastal sea waters). To reach this goal, reduction of water pollutant emission to the environment is needed. Our project focuses on pollution from agricultural sources which share in global pollution,which is high and growing. This is due to both intensification of agricultural activities and ignoring Agricultural Good Practice Code rules by farmers. In view of the above, this project is expected to provide analysis of selected catchments; especially those exposed to agricultural pollution risk, and propose adjustment strategies for new trends, still keeping in mind environ-merit protection.Our project concerns the area further called "sensitive area" (according to the rules of Regional Water Manage-ment Board in Warsaw). A part of Zglowiaczka fiver catchments in central Poland was defined as sensitive area (125.3 km2) where reduction of nitrogen and phosphorus run-off from agricultural land to water resources is especially needed. This is a typical agricultural district characterized by good soil quality (predominance of black swampy soil with deep and fertile humus layers). Due to this, it is the first and foremost high quality agricultural land, and almost forestless. The main topic of the research,with the use of the SWAT model, is to propose different means for reduction of migration of P and N to surface waters. Another problem is retention of water for actual and future irrigations. After model verification, calibration and validation, several climatic changes and reclamation strategies will be tested and simulated by the model to find the most effective and profitable solutions.The project focuses on supporting administration and self-governmental organization in the implementation of effective strategies of catchments

  6. Characteristics of chemistry and stable isotopes in groundwater of the Chaobai River catchment, Beijing

    Energy Technology Data Exchange (ETDEWEB)

    Li, J. [Key Laboratory of Engineering Geomechanics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Liu, J.; Wang, X. [Hydrogeology and Engineering Geology Team of Beijing, Beijing 100037 (China); Pang, Z. [Key Laboratory of Engineering Geomechanics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029 (China)

    2013-07-01

    Environmental isotopes and chemical compositions are useful tools for the study of groundwater flow systems. Groundwater of the Chaobai River catchment, Beijing was sampled for chemical and stable isotopes analyses in 2005. Geochemical signatures evolve progressively from CaMg-HCO{sub 3} to NaK-HCO{sub 3}, and then to Na-HCO{sub 3} compositions as groundwater flows from the mountain to discharge areas. Groundwater can be divided into two groups on the basis of stable isotope compositions: ancient groundwater and modern groundwater. Modern groundwater (-9.90/00 to -6.60/00 for δ{sup 18}O) plots along a line with a slope of 4.0 on a δ{sup 2}H versus δ{sup 18}O diagram, reflecting evaporation during the process of recharge, whereas ancient groundwater samples (30 to 12 Ka.) are different in isotopic composition (-11.00/00 and -68.20/00 for δ{sup 18}O and δ{sup 2}H, respectively), reflecting the cold and arid climate in the last glacial period. The results have important implications for groundwater management in Beijing City. (authors)

  7. A review of multivariate social vulnerability methodologies: a case study of the River Parrett catchment, UK

    Science.gov (United States)

    Willis, I.; Fitton, J.

    2016-06-01

    In the field of disaster risk reduction (DRR), there exists a proliferation of research into different ways to measure, represent, and ultimately quantify a population's differential social vulnerability to natural hazards. Empirical decisions such as the choice of source data, variable selection, and weighting methodology can lead to large differences in the classification and understanding of the "at risk" population. This study demonstrates how three different quantitative methodologies (based on Cutter et al., 2003; Rygel et al., 2006; Willis et al., 2010) applied to the same England and Wales 2011 census data variables in the geographical setting of the 2013/2014 floods of the River Parrett catchment, UK, lead to notable differences in vulnerability classification. Both the quantification of multivariate census data and resultant spatial patterns of vulnerability are shown to be highly sensitive to the weighting techniques employed in each method. The findings of such research highlight the complexity of quantifying social vulnerability to natural hazards as well as the large uncertainty around communicating such findings to stakeholders in flood risk management and DRR practitioners.

  8. Parameter uncertainty analysis for simulating streamflow in a river catchment of Vietnam

    Directory of Open Access Journals (Sweden)

    Dao Nguyen Khoi

    2015-07-01

    Full Text Available Hydrological models play vital roles in management of water resources. However, the calibration of the hydrological models is a large challenge because of the uncertainty involved in the large number of parameters. In this study, four uncertainty analysis methods, including Generalized Likelihood Uncertainty Estimation (GLUE, Parameter Solution (ParaSol, Particle Swarm Optimization (PSO, and Sequential Uncertainty Fitting (SUFI-2, were employed to perform parameter uncertainty analysis of streamflow simulation in the Srepok River Catchment by using the Soil and Water Assessment Tool (SWAT model. The four methods were compared in terms of the model prediction uncertainty, the model performance, and the computational efficiency. The results showed that the SUFI-2 method has the advantages in the model calibration and uncertainty analysis. This technique could be run with the smallest of simulation runs to achieve good prediction uncertainty bands and model performance. This technique could be run with the smallest of simulation runs to achieve good prediction uncertainty bands and model performance.

  9. Geostatistical analysis of soil moisture distribution in a part of Solani River catchment

    Science.gov (United States)

    Kumar, Kamal; Arora, M. K.; Hariprasad, K. S.

    2016-03-01

    The aim of this paper is to estimate soil moisture at spatial level by applying geostatistical techniques on the point observations of soil moisture in parts of Solani River catchment in Haridwar district of India. Undisturbed soil samples were collected at 69 locations with soil core sampler at a depth of 0-10 cm from the soil surface. Out of these, discrete soil moisture observations at 49 locations were used to generate a spatial soil moisture distribution map of the region. Two geostatistical techniques, namely, moving average and kriging, were adopted. Root mean square error (RMSE) between observed and estimated soil moisture at remaining 20 locations was determined to assess the accuracy of the estimated soil moisture. Both techniques resulted in low RMSE at small limiting distance, which increased with the increase in the limiting distance. The root mean square error varied from 7.42 to 9.77 in moving average method, while in case of kriging it varied from 7.33 to 9.99 indicating similar performance of the two techniques.

  10. Temporal variability in nutrient concentrations and loads in the River Tamar and its catchment (SW England) between 1974 and 2004.

    Science.gov (United States)

    Tappin, Alan D; Mankasingh, Utra; McKelvie, Ian D; Worsfold, Paul J

    2013-06-01

    This study reports the results from the analyses of a 30-year (1974-2004) river water quality monitoring dataset for NO x -N (NO₃-N + NO2-N), NH₄-N, PO₄-P and SiO₂-Si at the tidal limit of the River Tamar (SW England), an agriculturally dominated and sparsely populated catchment. Annual mean concentrations of NH4-N, PO₄-P and SiO₂-Si were similar to other rural UK rivers, while annual mean concentrations of NO x -N were clearly lower. Estimated values for the 1940s were much lower than for those of post-1974, at least for NO₃-N and PO₄-P. Flow-weighted mean concentrations of PO₄-P decreased by approximately 60 % between 1974 and 2004, although this change cannot be unequivocally ascribed to either PO₄-P stripping from sewage treatment work effluents or reductions in phosphate fertiliser applications. Lower-resolution sampling (to once per month) in the late 1990s may also have led to the apparent decline; a similar trend was also seen for NH4-N. There were no temporal trends in the mean concentrations of NO x -N, emphasising the continuing difficulty in controlling diffuse pollution from agriculture. Concentrations of SiO₂-Si and NO x -N were significantly and positively correlated with river flows ≤15 m(3) s(-1), showing that diffuse inputs from the catchment were important, particularly during the wet winter periods. In contrast, concentrations of PO₄-P and NH4-N did not correlate across any flow window, despite the apparent importance of diffuse inputs for these constituents. This observation, coupled with the absence of a seasonal (monthly) cycle for these nutrients, indicates that, for PO₄-P and NH4-N, there were no dominant sources and/or both undergo extensive within-catchment processing. Analyses of nutrient fluxes reveal net losses for NO₃-N and SiO₂-Si during the non-winter months; for NO3-N, this may be due to denitrification. Areal fluxes of NO x -N from the catchment were towards the higher end of the range for the UK

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

    Science.gov (United States)

    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

  12. Simulated tritium concentrations in river waters of the western Lake Taupo catchment, New Zealand with MODPATH particle tracking

    Directory of Open Access Journals (Sweden)

    M. A. Gusyev

    2014-03-01

    Full Text Available We simulated in a previous study tritium concentrations in the river waters of the western Lake Taupo catchment (WLTC using MODFLOW/MT3DMS model (Gusyev et al., 2013. The model was calibrated to match simulated tritium to measured tritium in river waters at baseflows of the Waihaha, Whanganui, Whareroa, Kuratau and Omori river catchments of the WLTC. Following from this work we now utilized the same MODFLOW model for the WLTC to calculate the pathways of groundwater particles (and their corresponding tritium concentrations using steady-state particle tracking with MODPATH. In order to simulate baseflow tritium concentrations with MODPATH, transit time distributions (TTDs such as cumulative frequency distribution (CFD and probability density function (PDF are generated with particle tracking for the river networks of the five WLTC catchment outflows. Then, PDFs are used in the convolution integral with tritium concentration time series obtained in the precipitation. The resulting MODPATH tritium concentrations yield a very good match to measured tritium concentrations and are similar to the MT3DMS simulated tritium concentrations, with the greatest variation occurring around the bomb peak. MODPATH and MT3DMS also yield similar Mean Transit Times (MTT of groundwater contribution to river baseflows, but the actual shape of the TTDs is strikingly different. While both distributions provide valuable information, the methodologies used to derive the TTDs are fundamentally different and hence must be interpreted differently. With the current models setting, only the methodology used with MODPATH provides the true TTD for use with the convolution integral.

  13. What impact might mitigation of diffuse nitrate pollution have on river water quality in a rural catchment?

    Science.gov (United States)

    Hutchins, Michael G

    2012-10-30

    Observations of river flow, river quality and solar radiation were collated to assess the degree to which light and nutrients may be limiting phytoplankton growth at seven sites in the River Ouse catchment in NE England under average conditions. Hydraulic information derived from river network model applications was then used to determine where river water has sufficient residence time above the tidal limit to facilitate bloom development. A nitrate model (NALTRACES) was developed to estimate the impact of land management change on mean river nitrate concentrations. Applications of this model showed that although agricultural activity contributes substantially to nitrate loads in the Ouse it is likely to have little impact on phytoplankton growth, which could still occur extensively in its absence given favourable sunny and dry conditions. As an example of a means of controlling light availability, establishing full riparian tree cover would appear to be a considerably more effective management scenario than suppressing inputs to the river of nitrate or phosphorus. Any actions should be prioritised in headwater areas such as the upper reaches of the Swale and Ure tributaries. These conclusions are in broad agreement with those arising from more detailed simulations at daily resolution using the QUESTOR river quality model. The combination of simple modelling approaches applied here allows an initial identification of suitable spatially-targeted options for mitigating against phytoplankton blooms which can be applied more widely at a regional or national level.

  14. River water quality modelling in developing a catchment water safety plan

    OpenAIRE

    Vieira, J. M. Pereira; Pinho, José L. S.

    2014-01-01

    The primary aim of a catchment water safety plan is to reduce risks within the catchment to protect the quality of drinking water sources at the intake point. Even where effective arrangements for catchment management and control have been implemented, unexpected deterioration in raw water quality can pose a risk to treated drinking water quality. Thus potential sources of pollution impacting the area of influence of the intake should be identified and monitored. An important part of any catc...

  15. Using gridded rainfall products in simulating streamflow in a tropical catchment – A case study of the Srepok River Catchment, Vietnam

    Directory of Open Access Journals (Sweden)

    Thom Vu Thi

    2017-03-01

    Full Text Available The precise rainfall estimate with appropriate spatial and temporal resolutions is a key input to distributed hydrological models. However, networks of rain gauges are often sparsely distributed in developing countries. To overcome such limitations, this study used some of the existing gridded rainfall products to simulate streamflow. Four gridded rainfall products, including APHRODITE, CFSR, PERSIANN, and TRMM, were used as input to the SWAT distributed hydrological model in order to simulate streamflow over the Srepok River Catchment in Vietnam. Besides that, the available rain gauges data were also used for comparison. Amongst the four different datasets, the TRMM and APHRODITE data show their best match to rain gauges data in simulating the daily and monthly streamflow with satisfactory precision in the 2000-2006 period. The result indicates that the TRMM and APHRODITE data have potential applications in driving hydrological model and water resources management in data-scarce and ungauged areas in Vietnam.

  16. Impact of river regulation on potential sediment mobilization and transport in an Alpine catchment

    Science.gov (United States)

    Costa, Anna; Molnar, Peter; Lane, Stuart N.; Bakker, Maarten

    2015-04-01

    identify the grain size-dependent effects of streamflow regulation, computations are applied to different grain sizes taken from grain size distributions of river bed sediment. The results show that flow regulation has indeed resulted in higher potential mobility of finer grain sizes during winter due to the increased flow, but not for the coarsest fractions which are mobilized only during summer high flows. Many studies of the impacts of major flow regulation have focused upon the effects of dams and flow diversions on sediment flux. In contrast, here we focus upon the effects of flow regulation on sediment transport potential downstream of a region of major flow regulation in an Alpine catchment. We show that the seasonal changes in streamflow arising from flow regulation impact upon sediment transport potential and these may be important in terms of the seasonal dynamics of sediment production (e.g. glacier erosion, landslides, rockfalls produced by heavy seasonal rainfall). In this context we also analyse suspended sediment concentration data and turbidity data at the outlet of the basin, in order to identify specific features of fine sediment production and transport processes. The present work is part of the research project SEDFATE funded by the SNF Sinergia Programme, which aims at quantifying the human impacts on the observed reduction of suspended sediment inflows to Lake Geneva.

  17. Soil and river contamination patterns of chlordecone in a tropical volcanic catchment in the French West Indies (Guadeloupe).

    Science.gov (United States)

    Crabit, A; Cattan, P; Colin, F; Voltz, M

    2016-05-01

    The aim of this study was to identify primary flow paths involved in the chlordecone (CLD) river contamination and quantify the CLD fluxes to assess CLD pollution levels and duration according to a typical catchment of the banana cropping area in the French Indies (Guadeloupe): the Pérou Catchment (12 km(2)) characterized by heavy rainfall (5686 mm year(-1)). Three sub-catchments (SC1, SC2 and SC3) were studied during the hydrological year 2009-2010: a pedological survey combined with a spatialized hydrochemical approach was conducted. The average soil concentration is higher in the Pérou Catchment (3400 μg kg(-1)) than in the entire banana cropping area in Guadeloupe (2100 μg kg(-1)). The results showed that CLD stocks in soils vary largely among soil types and farming systems: the weakest stocks are located upstream in SC1 (5 kg ha(-1)), where a majority of the area is non-cultivated; medium stocks are located in Nitisols downstream in SC3 (9 kg ha(-1)); and the greatest stocks are observed in SC2 on Andosols (12 kg ha(-1)) characterized by large farms. The annual water balance and the hydro-chemical analysis revealed that the three sub-catchments exhibited different behaviors. Pérou River contamination was high during low flows, which highlighted that contamination primarily originated from groundwater contributions. The results showed that only a small part of the catchment (SC2), contributing little to the water flow, comprises a major CLD contribution, which is in agreement with the highly contaminated andosol soils observed there. Another significant result considers that at least 50 years would be required to export the totality of the actual CLD soil stocks retained in the topsoil layer. The actual time for soil remediation will however be much longer considering (i) the necessary time for the chlordecone to percolate and be stored in the shallow aquifers and (ii) its travel time to reach the river.

  18. Seasonal variability of suspended sediment transport in the Seine river catchment area (France)

    Science.gov (United States)

    Franke, Christine; Baati, Selma; Ayrault, Sophie; Bonte, Philippe; Evrard, Olivier; Kissel, Catherine

    2010-05-01

    This study consists in an innovative application of environmental physico-chemical techniques on fluvial sediments with the aim to trace the seasonal changes in suspended sediment transport of the complex Seine river catchment area in northern France. The aim of this project is to develop a detailed understanding for the discrimination of naturally triggered and anthropogenic induced processes and their temporal changes with weather conditions. With a focus on the heavy metal fraction, we determine the regional distribution of the suspended material and search for environmental fingerprints demonstrating the influence of fluvial transport mechanisms, changes in concentration related to discharge variations or different sediment sources, and in-situ alteration caused by variations in the geochemical conditions (oxy-redox, pH, Eh, etc.). To achieve these goals, we apply a combination of straightforward rock magnetic hysteresis measurements (performed using an AGM2900 at the LSCE) and advanced scanning electron microscopy analyses (SEM). This interdisciplinary approach allows refining the detailed analysis of sediment trap samples, originating from Tessier et al. (2003), as recently shown by Franke et al. (2009). In our preliminary results, we observe a general increase in magnetic concentrations from summer to winter conditions, coupled with a magneto-mineralogic change to rather reduced metallic mineral phases. However, each riversection of the Seine system shows its specific trend line depending on the regional initial input, weathering conditions, drainage area and potential pollution sources. A systematic analysis of the detailed results will allow highlighting the climatic/seasonal influence on the metallic particle assembly. Keywords: Seine river system, environmental magnetism, suspended particulate matter, anthropogenic and natural input, magnetic hysteresis, scanning electron microscopy (SEM),, heavy metal pollution, seasonal variability References: Franke

  19. Quantifying uncertainty in the impacts of climate change on river discharge in sub-catchments of the River Yangtze and Yellow Basins, China

    Directory of Open Access Journals (Sweden)

    H. Xu

    2010-09-01

    Full Text Available Quantitative evaluations of the impacts of climate change on water resources are primarily constrained by uncertainty in climate projections from GCMs. In this study we assess uncertainty in the impacts of climate change on river discharge in two catchments of the River Yangtze and Yellow Basins that feature contrasting climate regimes (humid and semi-arid. Specifically we quantify uncertainty associated with GCM structure from a subset of CMIP3 AR4 GCMs (HadCM3, HadGEM1, CCSM3.0, IPSL, ECHAM5, CSIRO, CGCM3.1, SRES emissions scenarios (A1B, A2, B1, B2 and prescribed increases in global mean air temperature (1 °C to 6 °C. Climate projections, applied to semi-distributed hydrological models (SWAT 2005 in both catchments, indicate trends toward warmer and wetter conditions. For prescribed warming scenarios of 1 °C to 6 °C, linear increases in mean annual river discharge, relative to baseline (1961–1990, for the River Xiangxi and River Huangfuchuan are +9% and 11% per +1 °C, respectively. Intra-annual changes include increases in flood (Q05 discharges for both rivers as well as a shift in the timing of flood discharges from summer to autumn and a rise (24 to 93% in dry season (Q95 discharge for the River Xiangxi. Differences in projections of mean annual river discharge between SRES emission scenarios using HadCM3 are comparatively minor for the River Xiangxi (13% to 17% rise from baseline but substantial (73% to 121% for the River Huangfuchuan. With one minor exception of a slight (−2% decrease in river discharge projected using HadGEM1 for the River Xiangxi, mean annual river discharge is projected to increase in both catchments under both the SRES A1B emission scenario and 2° rise in global mean air temperature using all AR4 GCMs on the CMIP3 subset. For the River Xiangxi, there is great uncertainty associated with GCM structure in the magnitude of the rise in flood (Q05 discharges (−1% to 41% under SRES A1B and −3% to 41% under 2

  20. Quantifying uncertainty in the impacts of climate change on river discharge in sub-catchments of the Yangtze and Yellow River Basins, China

    Directory of Open Access Journals (Sweden)

    H. Xu

    2011-01-01

    Full Text Available Quantitative evaluations of the impacts of climate change on water resources are primarily constrained by uncertainty in climate projections from GCMs. In this study we assess uncertainty in the impacts of climate change on river discharge in two catchments of the Yangtze and Yellow River Basins that feature contrasting climate regimes (humid and semi-arid. Specifically we quantify uncertainty associated with GCM structure from a subset of CMIP3 AR4 GCMs (HadCM3, HadGEM1, CCSM3.0, IPSL, ECHAM5, CSIRO, CGCM3.1, SRES emissions scenarios (A1B, A2, B1, B2 and prescribed increases in global mean air temperature (1 °C to 6 °C. Climate projections, applied to semi-distributed hydrological models (SWAT 2005 in both catchments, indicate trends toward warmer and wetter conditions. For prescribed warming scenarios of 1 °C to 6 °C, linear increases in mean annual river discharge, relative to baseline (1961–1990, for the River Xiangxi and River Huangfuchuan are +9% and 11% per +1 °C respectively. Intra-annual changes include increases in flood (Q05 discharges for both rivers as well as a shift in the timing of flood discharges from summer to autumn and a rise (24 to 93% in dry season (Q95 discharge for the River Xiangxi. Differences in projections of mean annual river discharge between SRES emission scenarios using HadCM3 are comparatively minor for the River Xiangxi (13 to 17% rise from baseline but substantial (73 to 121% for the River Huangfuchuan. With one minor exception of a slight (−2% decrease in river discharge projected using HadGEM1 for the River Xiangxi, mean annual river discharge is projected to increase in both catchments under both the SRES A1B emission scenario and 2° rise in global mean air temperature using all AR4 GCMs on the CMIP3 subset. For the River Xiangxi, there is substantial uncertainty associated with GCM structure in the magnitude of the rise in flood (Q05 discharges (−1 to 41% under SRES A1B and −3 to 41% under 2

  1. Water resources in Central Asia - status quo and future conflicts in transboundary river catchments - the example of the Zarafshan River (Tajikistan-Uzbekistan)

    Science.gov (United States)

    Groll, Michael; Opp, Christian; Kulmatov, Rashid; Normatov, Inom; Stulina, Galina; Shermatov, Nurmakhmad

    2014-05-01

    Water is the most valuable resource in Central Asia and due to its uneven distribution and usage among the countries of the region it is also the main source of tension between upstream and downstream water users. Due to the rapidly shrinking glaciers in the Pamir, Tien-Shan and Alai mountains, the available water resources will, by 2030, be 30% lower than today while the water demand of the growing economies will increase by 30%. This will further aggravate the pressure on the water resources and increase the water deficit caused by an unsustainable water use and political agendas. These challenges can only be overcome by an integrated water resource management for the important transboundary river catchments. The basis for such an IWRM approach however needs to be a solid data base about the status quo of the water resources. To that end the research presented here provides a detailed overview of the transboundary Zarafshan River (Tajikistan-Uzbekistan), the lifeline for more than 6 mln people. The Zarafshan River is well suited for this as it is not only one of the most important rivers in Central Asia but because the public availability of hydrological and ecological data is very limited, Furthermore the catchment is characterized by the same imbalances in the Water-Energy-Food-Nexus as most river systems in that region, which makes the Zarafshan a perfect model river for Central Asia as a whole. The findings presented here are based on field measurements, existing data from the national hydrometeorological services and an extensive literature analysis and cover the status quo of the meteorological and hydrological characteristics of the Zarafshan as well as the most important water quality parameters (pH, conductivity, nitrate, phosphate, arsenic, chromate, copper, zinc, fluoride, petroleum products, phenols and the aquatic invertebrate fauna). The hydrology of the Zarafshan is characterized by a high natural discharge dynamic in the mountainous upper parts of

  2. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: Surficial Geology

    Science.gov (United States)

    Wieczorek, Michael E.; LaMotte, Andrew E.

    2010-01-01

    This tabular data set represents the area of surficial geology types in square meters compiled for every MRB_E2RF1 catchment of selected Major River Basins (MRBs, Crawford and others, 2006). The source data set is the "Digital data set describing surficial geology in the conterminous US" (Clawges and Price, 1999).The MRB_E2RF1 catchments are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2008). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering New England and Mid-Atlantic (MRB1), South Atlantic-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great basin (MRB6), the Pacific Northwest (MRB7) river basins, and California (MRB8).

  3. Calibration of a transient transport model to tritium measurements in rivers and streams in the Western Lake Taupo catchment, New Zealand

    Directory of Open Access Journals (Sweden)

    M. A. Gusyev

    2012-08-01

    Full Text Available Here we present a general approach of calibrating transient transport models to tritium concentrations in river waters developed for the MT3DMS/MODFLOW model of the Western Lake Taupo catchment, New Zealand. Tritium is a time-dependent tracer with radioactive half-life of 12.32 yr. In the transport model, the tritium input (measured in rain passes through the groundwater system, and the modelled tritium concentrations are compared to the measured tritium concentrations in the river outlets for the Waihaha, Whanganui, Whareroa, Kuratau and Omori river catchments from 2000–2007. For the Kuratau River, tritium was also measured between 1960 and 1970, which allowed us to fine-tune the transport model. In order to incorporate all surface flows from rivers to small streams, an 80 m uniform grid cell size was selected in the steady-state MODFLOW model for the model area of 1072 km2. The groundwater flow model was first calibrated to groundwater levels and stream flow observations. Then, the transport model was calibrated to the measured tritium concentrations in the river waters. The MT3DMS model results show good agreement with the measured tritium values in all five river catchments. Finally, the calibrated MT3DMS model is applied to simulate groundwater ages that are used to construct groundwater age distributions for the river catchments.

  4. Identifying sources of acidity and spatial distribution of acid sulfate soils in the Anglesea River catchment, southern Australia

    Science.gov (United States)

    Wong, Vanessa; Yau, Chin; Kennedy, David

    2015-04-01

    Globally, coastal and estuarine floodplains are frequently underlain by sulfidic sediments. When exposed to oxygen, sulfidic sediments oxidise to form acid sulfate soils, adversely impacting on floodplain health and adjacent aquatic ecoystems. In eastern Australia, our understanding of the formation of these coastal and estuarine floodplains, and hence, spatial distribution of acid sulfate soils, is relatively well established. These soils have largely formed as a result of sedimentation of coastal river valleys approximately 6000 years BP when sea levels were one to two metres higher. However, our understanding of the evolution of estuarine systems and acid sulfate soil formation, and hence, distribution, in southern Australia remains limited. The Anglesea River, in southern Australia, is subjected to frequent episodes of poor water quality and low pH resulting in closure of the river and, in extreme cases, large fish kill events. This region is heavily reliant on tourism and host to a number of iconic features, including the Great Ocean Road and Twelve Apostles. Poor water quality has been linked to acid leakage from mining activities and Tertiary-aged coal seams, peat swamps and acid sulfate soils in the region. However, our understanding of the sources of acidity and distribution of acid sulfate soils in this region remains poor. In this study, four sites on the Anglesea River floodplain were sampled, representative of the main vegetation communities. Peat swamps and intertidal marshes were both significant sources of acidity on the floodplain in the lower catchment. However, acid neutralising capacity provided by carbonate sands suggests that there are additional sources of acidity higher in the catchment. This pilot study has highlighted the complexity in the links between the floodplain, upper catchment and waterways with further research required to understand these links for targeted acid management strategies.

  5. Estimating subsurface water volumes and transit times in Hokkaido river catchments, Japan, using high-accuracy tritium analysis

    Science.gov (United States)

    Gusyev, Maksym; Yamazaki, Yusuke; Morgenstern, Uwe; Stewart, Mike; Kashiwaya, Kazuhisa; Hirai, Yasuyuki; Kuribayashi, Daisuke; Sawano, Hisaya

    2015-04-01

    The goal of this study is to estimate subsurface water transit times and volumes in headwater catchments of Hokkaido, Japan, using the New Zealand high-accuracy tritium analysis technique. Transit time provides insights into the subsurface water storage and therefore provides a robust and quick approach to quantifying the subsurface groundwater volume. Our method is based on tritium measurements in river water. Tritium is a component of meteoric water, decays with a half-life of 12.32 years, and is inert in the subsurface after the water enters the groundwater system. Therefore, tritium is ideally suited for characterization of the catchment's responses and can provide information on mean water transit times up to 200 years. Only in recent years has it become possible to use tritium for dating of stream and river water, due to the fading impact of the bomb-tritium from thermo-nuclear weapons testing, and due to improved measurement accuracy for the extremely low natural tritium concentrations. Transit time of the water discharge is one of the most crucial parameters for understanding the response of catchments and estimating subsurface water volume. While many tritium transit time studies have been conducted in New Zealand, only a limited number of tritium studies have been conducted in Japan. In addition, the meteorological, orographic and geological conditions of Hokkaido Island are similar to those in parts of New Zealand, allowing for comparison between these regions. In 2014, three field trips were conducted in Hokkaido in June, July and October to sample river water at river gauging stations operated by the Ministry of Land, Infrastructure, Transport and Tourism (MLIT). These stations have altitudes between 36 m and 860 m MSL and drainage areas between 45 and 377 km2. Each sampled point is located upstream of MLIT dams, with hourly measurements of precipitation and river water levels enabling us to distinguish between the snow melt and baseflow contributions

  6. Neotectonic formation of drainage patterns and their palaeohydrological implications for the Okwa River catchment, Botswana

    Science.gov (United States)

    Hartmann, Kai; Schmidt, Mareike; Shemang, Elisha; Zhang, Shuping; Frank, Riedel

    2014-05-01

    Large inter- and intramontane endorheic basins provide long term archives of environmental change, often integrating regional to continental climate driven process dynamics of huge drainage systems. On one hand the large-scale integration can be regarded as an advantage by averaging small-scale variations of either local hydrological peculiarities or random triggered drainage behaviour (e.g. internal thresholds, tectonics, etc.) and thus just recording atmospheric circulation pattern up to hemispherical scales with millennial resolution. Otherwise, with increasing basin size the process dynamic and their response system along one or more sediment cascades often become a complexity resulting in crucial problems of sedimentological archive interpretations by e.g. signal interference, equifinality or even multiple reworking. Therefore, studies of geomorphological or hydrological response processes and ecological adaption can only be undertaken on sub-catchment scale considering process dynamics along pathways. For southern-hemispheric palaeoclimate reconstruction of land-ocean linkages, Makgadikgadi Basin - as the largest (c. 37,000 km2) and deepest depression in the middle Kalahari - provides a fluvio-lacustrine archive in high-continental position since at least 300 kyr BP. Recent studies suggest a mega-lake high-stand within the basin for the Last Glacial Maximum (LGM) For the hydrological persistence of the lake for about 6 kyrs, the since Heinrich Event 1 (17-16 ka) inactive Okwa River seems to play a key role indicating a northward-shift of the winter rainfall zone. However, beside some dating of exposed shell bearing sediments at the river mouth, a thorough investigation of the c. 129,000 km2 drainage system is missing. Our presentation aims to point out the linkages between neotectonic activity and sediment transport. The combination of adaptive DEM-filter and multispectral remote sensing data reveals obvious traps (of neotectonic origin) of small temporary

  7. Design for participation in ecologically sound management of South Africa's Mlazi River Catchment

    NARCIS (Netherlands)

    Auerbach, R.

    1999-01-01

    Without local participation, integrated catchment management and Landcare will not become a general reality in South Africa. With support from the South African Water Research Commission, the University of Natal's Farmer Support Group set up the Ntshongweni Catchment Management Programme (NCMP) as a

  8. Design for participation in ecologically sound management of South Africa's Mlazi River catchment

    NARCIS (Netherlands)

    Auerbach, R.

    1999-01-01

    Without local participation, integrated catchment management and Landcare will not become a general reality in South Africa. With support from the South African Water Research Commission, the University of Natal's Farmer Support Group set up the Ntshongweni Catchment Management Programme

  9. Suspended sediment export in five intensive agricultural river catchments with contrasting land use and soil drainage characteristics

    Science.gov (United States)

    Sherriff, Sophie; Rowan, John; Melland, Alice; Jordan, Phil; Fenton, Owen; hUallacháin, Daire Ó.

    2015-04-01

    Soil erosion and sediment loss from land can have a negative impact on the chemical and ecological quality of freshwater resources. In catchments dominated by agriculture, prediction of soil erosion risk is complex due to the interaction of physical characteristics such as topography, soil erodibility, hydrological connectivity and climate. Robust measurement approaches facilitate the assessment of sediment loss magnitudes in relation to a range of agricultural settings. These approaches improve our understanding of critical sediment transfer periods and inform development of evidence-based and cost-effective management strategies. The aim of this study was to i) assess the efficacy of out-of-channel (ex-situ) suspended sediment measurement approaches, ii) to quantify the variability of sediment exported from five river catchments with varying hydrology and agricultural land uses over multiple years and iii) to investigate trends in relation to physical and land use characteristics when sediment data were compared between catchments. Sediment data were collected in five intensive agricultural river catchments in Ireland (3-11 km2) which featured contrasting land uses (predominantly intensive grassland or arable) and soil drainage classes (well, moderate and poor). High-resolution suspended sediment concentration data (SSC - using a calibrated turbidity proxy) were collected ex-situ and combined with in-stream discharge data measured at each catchment outlet to estimate suspended sediment yield (SSY - t km-2 yr-1). In two catchments additional in-stream turbidity monitoring equipment replicated ex-situ measurements including site specific calibration of individual in-stream and ex-situ turbidity probes. Depth-integrated samples were collected to assess the accuracy of both approaches. Method comparison results showed that true SSC values (from depth-integrated sampling) were predominantly within the 95% confidence interval of ex-situ predicted SSC consequently

  10. In search of the 'at risk' population: A review of quantitative social vulnerability techniques in the River Parrett catchment

    Science.gov (United States)

    Willis, Iain; Fitton, James

    2015-04-01

    In the field of Disaster Risk Reduction (DRR), disparate research agendas have led to an increasing divergence in the quantitative approaches used to define community social vulnerability in hazardous places. Though the output of such research methods have been aligned in their aim of producing a universal risk classification or Social Vulnerability Index (SoVI), the conceptual and statistical approaches have often varied greatly. Methodologies have differed in their use of multivariate statistics to classify small area census data, often making use of techniques such as Pareto ranking, Principal Component Analysis (PCA) or more recently, cluster analysis, to derive geodemographic-based assessments. In this research, two alternative paradigms were applied and contrasted to review community social vulnerability to flooding within the River Parrett catchment area, Somerset, UK. The UK experienced unprecedented rainfall during the winter of 2013/14 resulting in the flooding of 65 km2 of the River Parrett catchment area, Somerset. Approximately 600 properties were flooded and a number of towns cut off due to high floodwaters. It has been estimated that 3,300 properties are potentially exposed to a 1% annual probability flood event within the catchment, with this thought to rise to over 6,600 in the future, due to the impacts of climate change. Since the recent flooding, an action plan has been developed by Somerset County Council. However, the focus is predominantly on the physical aspects of the flooding hazard, with very little consideration for the social vulnerability of the communities affected. Within the catchment there are a range of socioeconomic profiles, including highly urbanised areas such as Yeovil, Taunton and Bridgewater, as well as numerous villages and hamlets. Therefore, the catchment provided an ideal case study area to model two divergent approaches for assessing social vulnerability to flooding. UK Census output information (2011) was used as the

  11. Lagtime of river systems to changes in pollutant load on the catchment: a regional scale assessment

    Science.gov (United States)

    Żurek, Anna J.; Różański, Kazimierz; Witczak, Stanisław

    2017-04-01

    Transport of conservative contaminants through groundwater systems (e.g. nitrate under oxidized conditions) is significantly delayed when compared to movement of those contaminants through surface water compartments. Characteristic time scales of groundwater movement may easily reach tens or hundreds of years. This results in large lagtimes of contaminant transport in the subsurface. These lagtimes are particularly important when response of river basins to measures aimed at recovery of good groundwater status is considered. Incorporating lagtime principles into water quality regulations may result in more realistic expectations when such policies are designed and implemented. The lagtime of contaminant transport in the subsurface with respect to transport through surface and near-surface (drainage) runoff can be separated into two components: (i) the delay associated with travel time of water (and contaminants) through the unsaturated zone, and (ii) the delay linked to time scales of groundwater flow, from the recharge area down to the discharge zone (river). Thus, the travel time of water through unsaturated and saturated zones can be considered a quantitative measure of the lagtime. Lagtime in the unsaturated zone on the territory of Poland was assessed on the basis of the existing Groundwater Vulnerability Map of Poland (GVMP) (Witczak et al., 2007; 2011). The adopted approach relies on MRT (Mean Residence Time) of water in the strata separating the saturated aquifer from the land surface, as an integrated vulnerability index. In the framework of GVMP, the MRT is calculated as turnover time of the infiltrating water in the vadose zone. The piston-flow type of water movement through the unsaturated zone is considered. The lagtime in the saturated zone (Tsat) can be approximated by travel time of water, flowing along the local hydraulic gradient to the closest river. The lagtime of river systems with respect to changes in pollutant load on the catchment is a sum

  12. Glacier retreat and projected river regime changes in the hydrologically highly-coupled Virkisjökull catchment, Iceland

    Science.gov (United States)

    Flett, Verity; Kirkbride, Martin; Black, Andrew; Everest, Jez; MacDonald, Alan

    2016-04-01

    Virkisjökull, an outlet glacier of the Oræfajökull icecap in SE Iceland, currently has 60% glacier cover, though this is reducing due to glacier retreat. Intensive monitoring over the last 4 years includes measurement of measuring ice ablation, proglacial discharge, dye-tracing of flow pathways, and deployment of three automatic weather stations at altitudes up to 880 m. These data calibrate a distributed hydrological model (WaSIM) to project potential river regime during stages of glacier retreat. Results show: (1) glacier hypsometry sensitises the catchment to a disproportionately rapid increase in runoff as the snowline rises onto a gentle ice cap resulting in in a potential annual increase in river discharge of up to 37% (2) a dominantly channelized glacial drainage system in all seasons with a rapid runoff response to melt: englacial flow of 0.58 m s-1 is comparable to the proglacial river velocity; and (3) longer-term, reduced glacier cover and snow storage will lead to a discharge regime dominated by short-term precipitation events in all seasons, and a reduced influence of the seasonal meltwater discharge peak. The study demonstrates the importance of glacier hypsometry above the present ELA as an influence on catchment hydrological response to potential climate warming.

  13. Multi-model data fusion for river flow forecasting: an evaluation of six alternative methods based on two contrasting catchments

    Science.gov (United States)

    Abrahart, R. J.; See, L.

    This paper evaluates six published data fusion strategies for hydrological forecasting based on two contrasting catchments: the River Ouse and the Upper River Wye. The input level and discharge estimates for each river comprised a mixed set of single model forecasts. Data fusion was performed using: arithmetic-averaging, a probabilistic method in which the best model from the last time step is used to generate the current forecast, two different neural network operations and two different soft computing methodologies. The results from this investigation are compared and contrasted using statistical and graphical evaluation. Each location demonstrated several options and potential advantages for using data fusion tools to construct superior estimates of hydrological forecast. Fusion operations were better in overall terms in comparison to their individual modelling counterparts and two clear winners emerged. Indeed, the six different mechanisms on test revealed unequal aptitudes for fixing different categories of problematic catchment behaviour and, in such cases, the best method(s) were a good deal better than their closest rival(s). Neural network fusion of differenced data provided the best solution for a stable regime (with neural network fusion of original data being somewhat similar) — whereas a fuzzified probabilistic mechanism produced a superior output in a more volatile environment. The need for a data fusion research agenda within the hydrological sciences is discussed and some initial suggestions are presented.

  14. Multi-model data fusion for river flow forecasting: an evaluation of six alternative methods based on two contrasting catchments

    Directory of Open Access Journals (Sweden)

    R. J. Abrahart

    2002-01-01

    Full Text Available This paper evaluates six published data fusion strategies for hydrological forecasting based on two contrasting catchments: the River Ouse and the Upper River Wye. The input level and discharge estimates for each river comprised a mixed set of single model forecasts. Data fusion was performed using: arithmetic-averaging, a probabilistic method in which the best model from the last time step is used to generate the current forecast, two different neural network operations and two different soft computing methodologies. The results from this investigation are compared and contrasted using statistical and graphical evaluation. Each location demonstrated several options and potential advantages for using data fusion tools to construct superior estimates of hydrological forecast. Fusion operations were better in overall terms in comparison to their individual modelling counterparts and two clear winners emerged. Indeed, the six different mechanisms on test revealed unequal aptitudes for fixing different categories of problematic catchment behaviour and, in such cases, the best method(s were a good deal better than their closest rival(s. Neural network fusion of differenced data provided the best solution for a stable regime (with neural network fusion of original data being somewhat similar — whereas a fuzzified probabilistic mechanism produced a superior output in a more volatile environment. The need for a data fusion research agenda within the hydrological sciences is discussed and some initial suggestions are presented. Keywords: data fusion, fuzzy logic, neural network, hydrological modelling

  15. A comparative analysis of projected impacts of climate change on river runoff from global and catchment-scale hydrological models

    Directory of Open Access Journals (Sweden)

    S. N. Gosling

    2011-01-01

    Full Text Available We present a comparative analysis of projected impacts of climate change on river runoff from two types of distributed hydrological model, a global hydrological model (GHM and catchment-scale hydrological models (CHM. Analyses are conducted for six catchments that are global in coverage and feature strong contrasts in spatial scale as well as climatic and developmental conditions. These include the Liard (Canada, Mekong (SE Asia, Okavango (SW Africa, Rio Grande (Brazil, Xiangxi (China and Harper's Brook (UK. A single GHM (Mac-PDM.09 is applied to all catchments whilst different CHMs are applied for each catchment. The CHMs include SLURP v. 12.2 (Liard, SLURP v. 12.7 (Mekong, Pitman (Okavango, MGB-IPH (Rio Grande, AV-SWAT-X 2005 (Xiangxi and Cat-PDM (Harper's Brook. The CHMs typically simulate water resource impacts based on a more explicit representation of catchment water resources than that available from the GHM and the CHMs include river routing, whereas the GHM does not. Simulations of mean annual runoff, mean monthly runoff and high (Q5 and low (Q95 monthly runoff under baseline (1961–1990 and climate change scenarios are presented. We compare the simulated runoff response of each hydrological model to (1 prescribed increases in global-mean air temperature of 1.0, 2.0, 3.0, 4.0, 5.0 and 6.0 °C relative to baseline from the UKMO HadCM3 Global Climate Model (GCM to explore response to different amounts of climate forcing, and (2 a prescribed increase in global-mean air temperature of 2.0 °C relative to baseline for seven GCMs to explore response to climate model structural uncertainty.

    We find that the differences in projected changes of mean annual runoff between the two types of hydrological model can be substantial for a given GCM (e.g. an absolute GHM-CHM difference in mean annual runoff percentage change for UKMO HadCM3 2 °C warming of up to 25%, and they are generally larger for indicators of high and low monthly runoff

  16. Effective Control of Non-Native American Mink by Strategic Trapping in a River Catchment in Mainland Britain.

    Science.gov (United States)

    Reynolds, Jonathan C; Richardson, Suzanne M; Rodgers, Ben J E; Rodgers, Owain R K

    2013-04-01

    The introduction of American mink (Neovison vison; hereafter mink) into Europe has had severe impacts on many native wildlife species, including the water vole (Arvicola amphibius) in mainland Britain. Although trapping has been widely used to attempt to control mink, managers have little direct evidence of its effect on mink density or distribution, particularly where immigration of mink from nearby areas is inevitable. Such evidence is needed to justify the use of lethal methods in conservation policy. During 2006-2010 we removed mink from the River Monnow Catchment in western Britain, using track-recording rafts to monitor continuously for mink presence, guiding a strategic trapping effort. The area monitored and trapped was increased in stages, from a core sub-catchment with 109 km of water-course in 2006, to a 421-km(2) catchment with 203 km of water-course in 2009. In each successive sub-catchment, mink detection and capture rates declined rapidly to near-zero levels after trapping began. Detections and captures showed seasonal peaks in every year corresponding to known dispersal periods, but also declined steadily from year to year, with increasing periods in which we did not detect mink. These results suggested that each sub-catchment was cleared of mink within a few months, with subsequent captures attributable to immigration. On average, we detected each mink 5.1 times before capture (daily probability of detection = 0.059 per mink and raft), and trapped them 3.4 days after deploying traps in response. On average, mink entering the area were likely to have been present for less than 13 days before capture. Water voles had been extinct in the Monnow Catchment since the 1980s. During 2006-2008 (starting 6 months after mink trapping commenced), we released 700 captive-bred water voles into the treatment area to re-establish a wild population. Persistence of this population through the 4 years of the project was considered indicative of effective mink control

  17. Modelling high-resolution snow cover precipitation supply for German river catchments with SNOW 4

    Science.gov (United States)

    Böhm, Uwe; Reich, Thomas; Schneider, Gerold; Fiedler, Anett

    2013-04-01

    Formation of snow cover causes a delayed response of surface to precipitation. Both melting of snow and release of liquid water retained within the snow cover form precipitation supply which contributes to runoff and infiltration. The model SNOW 4 is developed to simulate snow cover accumulation and depletion and the resulting precipitation supply on a regular grid. The core of the model is formed by a set of equations which describe the snow cover energy and mass balance. The snow surface energy balance is calculated as a result of the radiation balance and the heat fluxes between atmosphere, soil and snow cover. The available melting heat enters the mass balance computation part of the model and melting of snow or freezing of liquid water within the snow layer takes place depending on its sign. Retention, aging and snow cover regeneration are taken into consideration. The model runs operationally 4 times a day and provides both a snow cover and precipitation supply analysis for the last 30 hours and a forecast for up to 72 hours. For the 30-hour analysis, regionalised observations are used both to define the initial state and force the model. Hourly measurements of air temperature, water vapour pressure, wind speed, global radiation or sunshine duration and precipitation are interpolated to the model grid. For the forecast period, SNOW 4 obtains the required input data from the operational products of the COSMO-EU weather forecast model. The size of a grid box is 1km2. The model area covers a region of 1100x1000km2 and includes the catchments of the German rivers completely. The internal time step is set to 1 hour. Once a day, the compliance between model and regionalized snow cover data is assessed. If discrepancies exceed certain thresholds, the model must be adjusted by a weighted approach towards the observations. The model simulations are updated every six hours based on the most recent observations and weather forecasts. The model works operationally since

  18. Management of environmental impacts from coal mining in the upper Olifants River catchment as a function of age and scale

    Energy Technology Data Exchange (ETDEWEB)

    Hobbs, P.; Oelofse, S.H.H.; Rascher, J. [CSIR Natural Resources & Environment, Pretoria (South Africa)

    2008-07-01

    Effective water resource governance in a water scarce environment such as South Africa is a strategic issue in national sustainable development priorities. Acid mine drainage (AMD) is one of the largest liabilities of the mining industry due to its inherent threat to water resources, human health and the environment. Against the background of evolving water governance in South Africa, three examples are explored to reflect the management of AMD in the upper Olifants River catchment. The Brugspruit Water Pollution Control Works shows the scale of historic liabilities faced by the state, as well as the challenge of effectively addressing AMD within a resource-poor environment. The Controlled Discharge Scheme takes advantage of the natural assimilative capacity of the upper Olifants River system during high flow conditions to effect the controlled discharge of AMD. The Emalahleni Water Reclamation Plant exemplifies the successful initiative by large and well-resourced mining houses to achieve engineered sustainable mine water management.

  19. Modelling the impacts of strategic tree plantings on salt loads and flows in the Macquarie river catchment, NSW, Australia.

    Science.gov (United States)

    Herron, Natasha; Davis, Richard; Dawes, Warrick; Evans, Ray

    2003-05-01

    In Australia, problems of dryland and stream salinity have recently become the focus of a National Action Plan. In many river catchments, preliminary stream salt load and salinity targets have been set to define maximum permissible export levels in 2015. Afforestation has been proposed as a strategy for meeting these targets, although several studies suggest that widespread commercial tree plantations are likely to deliver net dis-benefits. However, the impacts on stream salt loads of more localised tree plantings in high salt yielding areas have not been quantified. In this paper we use a simple empirical model to predict the effects of various strategic and non-strategic tree planting scenarios on flows and salt loads in the mid-Macquarie catchment, New South Wales. A simple salt routing model is then used to estimate the effect of these changes on salt loads at the end-of-valley monitoring site for the Macquarie catchment. Results suggest that widespread land management interventions will be required to meet the preliminary salt load targets for this catchment. On their own, small-scale, strategic tree planting in high salt export areas of the mid-Macquarie area will not have a significant impact on salt loads at the end-of-valley monitoring site. While widespread tree plantings may reduce salt loads in the longer term, they are likely to cause streamflow losses in the shorter term. Thus, stream salinities are expected to rise initially, due to the different response times of groundwater and surface water systems to land use change.

  20. Development and field validation of an indicator to assess the relative mobility and risk of pesticides in the Lourens River catchment, South Africa

    CSIR Research Space (South Africa)

    Dabrowski, James M

    2013-11-01

    Full Text Available before discharging into False Bay at the Strand (S34°06´; E18°48´). The catchment region is 98 characterised by intensive farming, with orchards and vineyards in its middle reaches. The Lourens 99 River has a total catchment area of 92 km2 and receives... additional 111 sampling sites, (named after the orchard in closest proximity to the site - BB7, LG4, C and VW) were 112 located within four tributaries flowing into the Lourens River. Each of the four tributaries are 113 characterised by different crops...

  1. Climate and land-use change impact on faecal indicator bacteria in a temperate maritime catchment (the River Conwy, Wales)

    Science.gov (United States)

    Bussi, Gianbattista; Whitehead, Paul G.; Thomas, Amy R. C.; Masante, Dario; Jones, Laurence; Jack Cosby, B.; Emmett, Bridget A.; Malham, Shelagh K.; Prudhomme, Christel; Prosser, Havard

    2017-10-01

    Water-borne pathogen contamination from untreated sewage effluent and runoff from farms is a serious threat to the use of river water for drinking and commercial purposes, such as downstream estuarine shellfish industries. In this study, the impact of climate change and land-use change on the presence of faecal indicator bacteria in freshwater was evaluated, through the use of a recently-developed catchment-scale pathogen model. The River Conwy in Wales has been used as a case-study, because of the large presence of livestock in the catchment and the importance of the shellfish harvesting activities in its estuary. The INCA-Pathogens catchment model has been calibrated through the use of a Monte-Carlo-based technique, based on faecal indicator bacteria measurements, and then driven by an ensemble of climate projections obtained from the HadRM3-PPE model (Future Flow Climate) plus four land-use scenarios (current land use, managed ecosystem, abandonment and agricultural intensification). The results show that climate change is not expected to have a very large impact on average river flow, although it might alter its seasonality. The abundance of faecal indicator bacteria is expected to decrease in response to climate change, especially during the summer months, due to reduced precipitation, causing reduced runoff, and increased temperature, which enhances the bacterial die-off processes. Land-use change can also have a potentially large impact on pathogens. The "managed ecosystems" scenario proposed in this study can cause a reduction of 15% in average water faecal indicator bacteria and up to 30% in the 90th percentile of water faecal indicator bacteria, mainly due to the conversion of pasture land into grassland and the expansion of forest land. This study provides an example of how to assess the impacts of human interventions on the landscape, and what may be the extent of their effects, for other catchments where the human use of the natural resources in the

  2. Institutional aspects of proportional water allocation in practice: case of the Odzani River Irrigation Company, Save Catchment, Zimbabwe

    Science.gov (United States)

    Senzanje, A.; van der Zaag, P.

    Under the new Water Act [Government of Zimbabwe, 1998. Water Act, Chapter 20:24, No. 31/98. Government Printers, Harare] of Zimbabwe which abolished the priority date system for the allocation of surface water in a catchment, it is widely believed that the alternative will be the proportional water allocation system. The proportional water allocation system has been practiced by groups of water users in a number of sub-catchments in Zimbabwe including Mupfuri, Mazowe and Odzi River systems, mainly in the form of dam syndicates (groups of users jointly owning a dam) and irrigation companies (groups of irrigators sharing one source of water). This paper presents the practical experiences with, and lessons that can be learnt from proportional water allocation in the Odzani River Irrigation Company (ORIC) on the Odzi River system in Manicaland in Zimbabwe. ORIC was formed under the provisions of the old Water Act after the construction of the canal, and currently has 50 irrigating members. They are engaged in a variety of agricultural enterprises that include crop production, horticulture and dairying. All members have sub-permits (sub-rights) that enable them to draw water, but the company has a single permit to abstract water from the Odzi River into their supply canal. Farmers’ perception and understanding of proportional water allocation varied but generally defined it as getting a certain percentage of water depending on the amount available in the canal and one’s water permit. One of the major sources of problems in ORIC is inequitable access to water arising from water poaching. Overall, ORIC farmers felt that for proportional water allocation to work properly, the services of a fulltime water bailiff are required, farmers must have their own storage facilities, water should be metered, members should participate fully in decision making, politics should be kept to a minimum and conflicts must be resolved internally.

  3. Assessment of environmental improvement measures using a novel integrated model: a case study of the Shenzhen River catchment, China.

    Science.gov (United States)

    Qin, Hua-Peng; Su, Qiong; Khu, Soon-Thiam

    2013-01-15

    Integrated water environmental management in a rapidly urbanizing area often requires combining social, economic and engineering measures in order to be effective. However, in reality, these measures are often considered independently by different planners, and decisions are made in a hierarchical manner; this has led to problems in environmental pollution control and also an inability to devise innovative solutions due to technological lock-in. In this paper, we use a novel coupled system dynamics and water environmental model (SyDWEM) to simulate the dynamic interactions between the socio-economic system, water infrastructure and receiving water in a rapidly urbanizing catchment in Shenzhen, China. The model is then applied to assess the effects of proposed socio-economic or engineering measures on environmental and development indicators in the catchment for 2011-2020. The results indicate that 1) measures to adjust industry structures have a positive effect on both water quantity and quality in the catchment; 2) measures to increase the labor productivity, the water use efficiency, the water transfer quota or the reclaimed wastewater reuse can alleviate the water shortage, but cannot improve water quality in the river; 3) measures to increase the wastewater treatment rate or the pollutant removal rate can improve water quality in the river, but have no effect on water shortage. Based on the effectiveness of the individual measures, a combination of socio-economic and engineering measures is proposed, which can achieve water environmental sustainability in the study area. Thus, we demonstrate that SyDWEM has the capacity to evaluate the effects of both socio-economic and engineering measures; it also provides a tool for integrated decision making by socio-economic and water infrastructure planners.

  4. Organochlorine pesticides (OCPs) in the Indus River catchment area, Pakistan: Status, soil-air exchange and black carbon mediated distribution.

    Science.gov (United States)

    Bajwa, Anam; Ali, Usman; Mahmood, Adeel; Chaudhry, Muhammad Jamshed Iqbal; Syed, Jabir Hussain; Li, Jun; Zhang, Gan; Jones, Kevin C; Malik, Riffat Naseem

    2016-06-01

    Organochlorine pesticides (OCPs) were investigated in passive air and soil samples from the catchment area of the Indus River, Pakistan. ∑15OCPs ranged between 0.68 and 13.47 ng g(-1) in soil and 375.1-1975 pg m-(3) in air. HCHs and DDTs were more prevalent in soil and air compartments. Composition profile indicated that β-HCH and p,p'-DDE were the dominant of all metabolites among HCHs and DDTs respectively. Moreover, fBC and fTOC were assessed and evaluated their potential role in the distribution status of OCPs. The fTOC and fBC ranged between 0.77 and 2.43 and 0.04-0.30% respectively in soil. Regression analysis showed the strong influence of fBC than fTOC on the distribution of OCPs in the Indus River catchment area soil. Equilibrium status was observed for β-HCH, δ-HCH, p,p'-DDD, o,p'-DDT, TC, HCB and Heptachlor with ff ranged between 0.3 and 0.59 while assessing the soil-air exchange of OCPs.

  5. An analysis of the environmental mobility of radiostrontium from weapons testing and Chernobyl in Finnish river catchments

    Energy Technology Data Exchange (ETDEWEB)

    Cross, M.A. E-mail: mac@ceh.ac.uk; Smith, J.T.; Saxen, R.; Timms, D

    2002-07-01

    The mobility of radiostrontium within the Arctic environment and surrounding area has been studied by analysing the mobility of {sup 90}Sr in river catchments that are within Finland. The environmental mobility of {sup 90}Sr deposited by both nuclear weapons testing and the Chernobyl accident has been investigated in five Finnish river catchments. Different models assessing the time-dependent mobility of {sup 90}Sr have been evaluated. No significant differences were found between the mobility of {sup 90}Sr from nuclear weapons tests and from the Chernobyl accident. Model parameters obtained by fitting to the measurements of the deposition and runoff rates of the nuclear weapons test fallout gave predictions which were consistent with the mid- and long-term contamination by the Chernobyl fallout. A comparison of {sup 90}Sr with {sup 137}Cs showed that they had similar mobility on deposition but, as time passed, the relative mobility of {sup 90}Sr increased with respect to {sup 137}Cs over a period of 5-8 years. Once the relative migration of {sup 90}Sr with respect to {sup 137}Cs reached equilibrium, its runoff rate was, on average, approximately an order of magnitude greater than {sup 137}Cs.

  6. Characterisation of the hydrogeology of the Augustus River catchment, Western Australia

    Science.gov (United States)

    Wilkes, Shane M.; Clement, T. Prabhakar; Otto, Claus J.

    Understanding the hydrogeology of weathered rock catchments is integral for the management of various problems related to increased salinity within the many towns of Western Australia. This paper presents the results of site characterisation investigations aimed at improving the overall understanding of the hydrogeology of the southern portion of the Augustus River catchment, an example of a weathered rock catchment. Site data have highlighted the presence of both porous media aquifers within the weathered profile and fractured rock aquifers within the basement rocks. Geophysical airborne surveys and other drilling data have identified a large number of dolerite dykes which crosscut the site. Fractured quartz veins have been found along the margins of these dolerite dykes. Detailed groundwater-level measurements and barometric efficiency estimates indicate that these dolerite dykes and fractured quartz veins are affecting groundwater flow directions, promoting a strong hydraulic connection between all aquifers, and also influencing recharge mechanisms. The hydrogeological significance of the dolerite dykes and fractured quartz veins has been assessed using a combination of high-frequency groundwater-level measurements (30-min sampling interval), rainfall measurements (5-min sampling interval) and barometric pressure fluctuations (30-min sampling interval). A conceptual model was developed for describing various hydrogeological features of the study area. The model indicates that fractured quartz veins along the margins of dolerite dykes are an important component of the hydrogeology of the weathered rock catchments. Comprendre l'hydrogéologie des bassins en roches altérées est essentiel pour la gestion de différents problèmes liés à l'augmentation de la salinité dans de nombreuses villes d'Australie occidentale. Cet article présente les résultats d'études de caractérisation de sites conduites pour améliorer la compréhension de l'hydrogéologie de la

  7. The logic of participation: critical perspectives on the 'participatory turn' in river and catchment management

    Science.gov (United States)

    Lane, Stuart

    2014-05-01

    regarding those who currently participate; necessary, because of changes in the water management system that make an existing system inherently less participative; or ignorant, because authorities do not realise that there are already effective systems of participation in water management that are invisible, or only partly visible, and so too readily overlooked. To explore this issue, I focus upon a proposed restructuring of the Inland Drainage Boards (IDBs) of England and Wales over the last decade. The IDBs have developed, in some cases over many centuries, as organisations responsible for the management of water levels in areas of special drainage need, providing a range of water supply, flood risk management and ecosystem services. They cover 9.7% and 1.4% of the land area of England and Wales respectively and there are currently 121 in total. They provide an interesting case example because up until the restructuring process began, they were organized around relatively small-in-size drainage districts and governed by members elected from the payers of agricultural drainage rates (owners, occupiers or tenants) or appointed from elected local authority members, in proportion to the payments the local authorities were making to the IDB. They were, in effect, highly participatory forms of hydrological governance as many of those who paid and who were elected were genuinely those who lived within their own water management system. What I show in this paper is that this proved highly unsatisfactory to legislators and other organisations involved in river management. Under the pre-text that river management should respect catchment boundaries, the IDBs were progressively encouraged to create larger spatial units with smaller numbers of elected representatives, initially as amalgamation to share services and functions, eventually into large stand-alone boards. The latter was preferred so as to provide efficiency savings and to be more readily seen as accountable to legislation

  8. The combined impact on the flooding in Vietnam's Mekong River delta of local man-made structures, sea level rise, and dams upstream in the river catchment

    Science.gov (United States)

    Le, Thi Viet Hoa; Nguyen, Huu Nhan; Wolanski, Eric; Tran, Thanh Cong; Haruyama, Shigeko

    2007-01-01

    The Mekong River delta plays an important role in the Vietnamese economy and it has been severely impacted during this century by a series of unusually large floods. In the dry season the delta is also impacted by salinity intrusion and tides. These effects have caused severe human hardship. To mitigate these impacts, a large number of engineering structures, primarily dykes and weirs, have been built in the delta in recent years and are still being built, mainly to control floods and saltwater intrusion. These control measures are still being upgraded. A GIS-linked numerical model shows that the flood levels in the delta depend on the combined impacts of high river flows in the Mekong River, storm surges, sea level rise, and the likely, future siltation of the Mekong Estuary resulting from the construction of dams in China as well as many other dams proposed throughout the remaining river catchment. The model suggests that the engineering structures in the delta increase the flow velocities in the rivers and canals, increasing bank erosion, and cause the water to be deeper in the rivers and canals. This increases flooding in the non-protected areas of the delta and increases the risk of catastrophic failure of the dykes in the protected areas. The model also predicts that a sea level rise induced by global warming will enhance flooding in the Mekong River delta in Vietnam, and that flooding may worsen in the long term as a result of estuarine siltation resulting from the construction of dams. At the scale of the Mekong River basin, a multinational water resources management plan is needed that includes the hydrological needs of the delta. At the scale of the delta, a compromise is needed between allowing some flooding necessary for agriculture and preventing catastrophic flooding to alleviate human suffering.

  9. The River Lune fact file

    OpenAIRE

    1994-01-01

    This document provides a brief introduction to the River Lune catchment and the role that the National Rivers Authority plays in catchment management. Included are a map of the catchment and short introductions to fisheries and characteristics of the catchment.

  10. Entire Catchment and Buffer Zone Approaches to Modeling Linkage Between River Water Quality and Land Cover——A Case Study of Yamaguchi Prefecture, Japan

    Institute of Scientific and Technical Information of China (English)

    Bahman Jabbarian AMIRI; Kaneyuki NAKANE

    2008-01-01

    This study investigated the linkages between fiver water quality and land use in river catchments in Yama-guchi Prefecture, the western Japan, in order to examine the effect of land use changes of both entire catchment andbuffer zone on river water quality. Dissolved Oxygen (DO), pH, Biological Oxygen Demand (BOD), Suspended Solids(SS), Escherichia coli, Total Nitrogen (TN) and Total Phosphorus (TP) were eousidered as river water quality indica-tors. Satellite images were applied to generating the land use map. Multiple regression model was applied to linkingthe changes in the fiver water quality with the land uses in both entire catchment area and buffer zone. The results in-dicate that the integrative application of land use data from the entire catchment and the buffer zone could give rise tomore robust model to predict the concentrations of Suspended Solids (r2=0.88) and Total Nitrogen (r2=0.90), ratherthan models which separately considered land use data in catchment and buffer zone.

  11. [Contamination and ecological risk assessment of polycyclic aromatic hydrocarbons in water and in Karst underground river catchment].

    Science.gov (United States)

    Lan, Jia-Cheng; Sun, Yu-Chuan; Tian, Ping; Lu, Bing-Qing; Shi, Yang; Xu, Xin; Liang Zuo-Bing; Yang, Ping-Heng

    2014-10-01

    Water samples in Laolongdong underground river catchment were collected to determine the concentration, compositional profiles, and evaluate ecological risk of 16 priority polycyclic aromatic hydrocarbons (PAHs). PAHs were measured by GC/MS. The total concentrations of 16 PAH ranged from 81.5-8019 ng · L(-1) in underground river, 288.7-15,200 ng · L(-1) in karst springs, and 128.4-2,442 ng · L(-1) in surface water. Affected by waste water from Huangjueya town, concentrations of PAHs in underground river were higher than those in surface water and waste water from sinkhole. The PAHs profiles were dominated by 3 ring PAHs. There were differences of monthly variations of PAHs contents in the water, due to waste water, season and different characteristics of PAH. Surface water and waste water from sinkhole played an important role on contamination in the river. The levels of ecological risk were generally moderately polluted and heavily polluted according to all detected PAH compounds in the water.

  12. An Explicit Representation of High Resolution River Networks using a Catchment-based Land Surface Model with the NHDPlus dataset for California Region

    Science.gov (United States)

    Liu, Z.; Kim, H.; Famiglietti, J. S.

    2011-12-01

    The main motivation of this study is to characterize how accurately we can estimate river discharge, river depth and inundation extent using an explicit representation of the river network with a catchment-based hydrological and routing modeling system (CHARMS) framework. Here we present a macroscale implementation of CHARMS over California. There are two main components in CHARMS: a land surface model based on National Center Atmospheric Research Community Land Model (CLM) 4.0, which is modified for implementation on a catchment template; and a river routing model that considers the water transport of each river reach. The river network is upscaled from the National Hydrography Dataset Plus (NHDPlus) to the Hydrologic Unit Code (HUC8) river basins. Both long-term monthly and daily streamflow simulation are generated and show reasonable results compared with gage observations. With river cross-section profile information derived from empirical relationships between channel dimensions and drainage area, river depth and floodplain extent associated with each river reach are also explicitly represented. Results have implications for assimilation of surface water altimetry and for implementation of the approach at the continental scale.

  13. A comparative analysis of projected impacts of climate change on river runoff from global and catchment-scale hydrological models

    Directory of Open Access Journals (Sweden)

    S. N. Gosling

    2010-09-01

    Full Text Available We present a comparative analysis of projected impacts of climate change on river runoff from two types of distributed hydrological model, a global hydrological model (GHM and catchment-scale hydrological models (CHM. Analyses are conducted for six catchments that are global in coverage and feature strong contrasts in spatial scale as well as climatic and developmental conditions. These include the Liard (Canada, Mekong (SE Asia, Okavango (SW Africa, Rio Grande (Brazil, Xiangxi (China and Harper's Brook (UK. A single GHM (Mac-PDM.09 is applied to all catchments whilst different CHMs are applied for each catchment. The CHMs include SLURP v. 12.2 (Liard, SLURP v. 12.7 (Mekong, Pitman (Okavango, MGB-IPH (Rio Grande, AV-SWAT-X 2005 (Xiangxi and Cat-PDM (Harper's Brook. Simulations of mean annual runoff, mean monthly runoff and high (Q5 and low (Q95 monthly runoff under baseline (1961–1990 and climate change scenarios are presented. We compare the simulated runoff response of each hydrological model to (1 prescribed increases in global-mean air temperature of 1.0, 2.0, 3.0, 4.0, 5.0 and 6.0 °C relative to baseline from the UKMO HadCM3 Global Climate Model (GCM to explore response to different amounts of climate forcing, and (2 a prescribed increase in global-mean air temperature of 2.0 °C relative to baseline for seven GCMs to explore response to climate model structural uncertainty.

    We find that the differences in projected changes of mean annual runoff between the two types of hydrological model can be substantial for a given GCM, and they are generally larger for indicators of high and low monthly runoff. However, they are relatively small in comparison to the range of projections across the seven GCMs. Hence, for the six catchments and seven GCMs we considered, climate model structural uncertainty is greater than the uncertainty associated with the type of hydrological model applied. Moreover, shifts in the seasonal cycle of runoff

  14. Influence of snow pack and soil water dynamics on river flows in un-glaciarized Himalayan catchments.

    Science.gov (United States)

    Eeckman, Judith; Neppel, Luc; Chevalier, Pierre; Delclaux, François; Boone, Aaron

    2016-04-01

    In the Central Himalayas, it is generally accepted that 80 % of the annual precipitation occurs during the monsoon months (June - September). However, surveys with local populations show that surface water is available throughout the year. The main question then is to identify the origin of these surface flows. One hypothesis proposes that they are provided by glacial melt during the dry season. However, on the one hand, this historically "permanent" supply is also observed in catchments with little or no glacial contribution, and on the other hand, annual volumes cannot be totally explained by the glacial mass balances currently monitored. Therefore, a better understanding of the hydrological processes is needed for quantifying the influence of the inter-seasonal surface (snow) and sub-surface storage on surface flows outside of the monsoon season. One solution consists in the application of modelling tools. However, simulations for Himalayan catchments are limited due to a lack of knowledge regarding their hydrological behaviour. The main source of uncertainty in poorly monitored environments is the scarcity of observations, which can be used for model calibration and evaluation. In this study, physically-based modelling with the ISBA Soil-Vegetation-Atmosphere transfer scheme is applied to small catchments whose physical characteristics are well studied, therefore this approach could constitute an interesting way for understanding hydrological systems. For that purpose, two small slope catchments selected in the Dudh Koshi River basin (Eastern Nepal), which represent high and mid-mountain environments, are studied in order to evaluate the spatial variability of the studied processes. They are equipped with 6 stations for air temperature and precipitation observations. A distributed approach allows a better representation of the spatial variation of hydro-climatic processes. Moreover, the descriptions of surfaces currently available at global scales are enhanced

  15. Testing a river basin model with sensitivity analysis and autocalibration for an agricultural catchment in SW Finland

    Directory of Open Access Journals (Sweden)

    S. TATTARI

    2008-12-01

    Full Text Available Modeling tools are needed to assess (i the amounts of loading from agricultural sources to water bodies as well as (ii the alternative management options in varying climatic conditions. These days, the implementation of Water Framework Directive (WFD has put totally new requirements also for modeling approaches. The physically based models are commonly not operational and thus the usability of these models is restricted for a few selected catchments. But the rewarding feature of these process-based models is an option to study the effect of protection measures on a catchment scale and, up to a certain point, a possibility to upscale the results. In this study, the parameterization of the SWAT model was developed in terms of discharge dynamics and nutrient loads, and a sensitivity analysis regarding discharge and sediment concentration was made. The SWAT modeling exercise was carried out for a 2nd order catchment (Yläneenjoki, 233 km2 of the Eurajoki river basin in southwestern Finland. The Yläneenjoki catchment has been intensively monitored during the last 14 years. Hence, there was enough background information available for both parameter setup and calibration. In addition to load estimates, SWAT also offers possibility to assess the effects of various agricultural management actions like fertilization, tillage practices, choice of cultivated plants, buffer strips, sedimentation ponds and constructed wetlands (CWs on loading. Moreover, information on local agricultural practices and the implemented and planned protective measures were readily available thanks to aware farmers and active authorities. Here, we studied how CWs can reduce the nutrient load at the outlet of the Yläneenjoki river basin. The results suggested that sensitivity analysis and autocalibration tools incorporated in the model are useful by pointing out the most influential parameters, and that flow dynamics and annual loading values can be modeled with reasonable

  16. Riverine CO2 emissions in the Wuding River catchment on the Loess Plateau: Environmental controls and dam impoundment impact

    Science.gov (United States)

    Ran, Lishan; Li, Lingyu; Tian, Mingyang; Yang, Xiankun; Yu, Ruihong; Zhao, Ji; Wang, Lixin; Lu, X. X.

    2017-06-01

    River ecosystems contribute significantly to CO2 emissions. However, estimates of global riverine CO2 emissions remain greatly uncertain owing to the absence of a comprehensive and spatially resolved CO2 emission measurement. Based on intensive field measurements using floating chambers, riverine CO2 evasion in the Wuding River catchment on the Loess Plateau was investigated. Lateral carbon derived from soil respiration and chemical weathering played a central role in controlling the variability of riverine CO2 partial pressure (pCO2). In addition, in-stream processing of allochthonous organic carbon was an also important source of CO2 excess, modulating the influence of lateral carbon inputs. All the surveyed streams were net CO2 sources, exhibiting pronounced spatial and seasonal variabilities. The mean CO2 efflux was 172, 116, and 218 mmol m-2 d-1 in spring, summer, and autumn, respectively. Unlike the commonly observed strongest CO2 emissions in headwater streams, the increasing CO2 efflux with stream order in the Wuding River catchment reflects its unique geomorphologic landscape in controlling CO2 emissions. While in reservoirs, the pCO2 was more controlled by primary production with aquatic photosynthetic assimilation constraining it to a lower level. Both the magnitude and direction of CO2 evasion from reservoirs have been greatly altered. Contrast to streams with large CO2 effluxes, reservoirs were small carbon sources and even carbon sinks, due primarily to greatly reduced turbulence and enhanced photosynthesis. In view of the large number of reservoirs on the Loess Plateau, assessing the resulting changes to CO2 emissions and their implications for regional carbon budgets warrants further research.

  17. Characterisation of Shigella species isolated from river catchments in the North West province of South Africa

    Directory of Open Access Journals (Sweden)

    Constance Wose Kinge

    2010-10-01

    Full Text Available The occurrence and distribution of Shigella species in water from the five river catchments in the North West province of South Africa were investigated. Shigella is a Gram-negative, non-motile, facultative anaerobic bacillus that causes shigellosis, an important cause of morbidity and mortality in high-risk populations (such as children, the elderly and immuno-compromised individuals that depend on river water. A total of 54 water samples collected in winter (April 2007 to July 2007 and summer (December 2007 to March 2008 were cultured on Salmonella-Shigella agar by the spread-plate method. Suspected Shigella isolates obtained were characterised by primary biochemical (Triple Sugar Iron agar and agglutination and molecular (polymerase chain reactions, PCR tests. Amplification of the invasion plasmid gene (ipaH by PCR was done to confirm the presence of Shigella spp. in water. In total, 214 Shigella boydii, 15 Shigella dysenteriae, 11 Shigella flexneri and 2 Shigella sonnei were confirmed by serotyping in both winter and summer samples. The ipaH gene (606 bp was present in 176 and 49 of the winter and summer isolates, respectively. The presence of Shigella spp. in water was confirmed with over 90% specificity. The need for more effective management of these river catchments and the provision of potable water and sanitation facilities is needed to minimise the occurrence and transmission of water-borne diseases caused by these and other pathogenic bacteria.

  18. Calibration of a transient transport model to tritium measurements in rivers and streams in the Western Lake Taupo catchment, New Zealand

    OpenAIRE

    Gusyev, M. A.; Toews, M.; U. Morgenstern; Stewart, M.; C. Daughney; Hadfield, J.

    2012-01-01

    Here we present a general approach of calibrating transient transport models to tritium concentrations in river waters developed for the MT3DMS/MODFLOW model of the Western Lake Taupo catchment, New Zealand. Tritium is a time-dependent tracer with radioactive half-life of 12.32 yr. In the transport model, the tritium input (measured in rain) passes through the groundwater system, and the modelled tritium concentrations are compared to the measured tritium concentrations in the river outl...

  19. Quantifying potential water savings from clearing invasive alien Eucalyptus camaldulensis using in situ and high resolution remote sensing data in the Berg River Catchment, Western Cape, South Africa

    CSIR Research Space (South Africa)

    Dzikiti, Sebinasi

    2016-02-01

    Full Text Available , to provide an indication of the impacts of clearing on streamflow under Mediterranean climatic conditions. The study was conducted at two adjacent sites in the Berg River catchment, Western Cape Province in South Africa. One site was densely invaded by E...

  20. Impacts of climate change on the seasonality of low flows in 134 catchments in the river Rhine basin using an ensemble of bias-corrected regional climate simulations.

    NARCIS (Netherlands)

    Demirel, M.C.; Booij, M.J.; Hoekstra, A.Y.

    2013-01-01

    The impacts of climate change on the seasonality of low flows were analysed for 134 sub-catchments covering the River Rhine basin upstream of the Dutch-German border. Three seasonality indices for low flows were estimated, namely the seasonality ratio (SR), weighted mean occurrence day (WMOD) and we

  1. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: Level 3 Nutrient Ecoregions, 2002

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This tabular data set represents the area of each level 3 nutrient ecoregion in square meters compiled for every MRB_E2RF1 catchment of the Major River Basins (MRBs,...

  2. Attributes for MRB_E2RF1 Catchments in Selected Major River Basins of the Conterminous United States: Contact Time, 2002

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This tabular data set represents the average contact time, in units of days, compiled for every MRB_E2RF1 catchment of Major River Basins (MRBs, Crawford and others,...

  3. A Simple Scheme for Modeling Irrigation Water Requirements at the Regional Scale Applied to an Alpine River Catchment

    Directory of Open Access Journals (Sweden)

    Pascalle C. Smith

    2012-11-01

    Full Text Available This paper presents a simple approach for estimating the spatial and temporal variability of seasonal net irrigation water requirement (IWR at the catchment scale, based on gridded land use, soil and daily weather data at 500 × 500 m resolution. In this approach, IWR is expressed as a bounded, linear function of the atmospheric water budget, whereby the latter is defined as the difference between seasonal precipitation and reference evapotranspiration. To account for the effects of soil and crop properties on the soil water balance, the coefficients of the linear relation are expressed as a function of the soil water holding capacity and the so-called crop coefficient. The 12 parameters defining the relation were estimated with good coefficients of determination from a systematic analysis of simulations performed at daily time step with a FAO-type point-scale model for five climatically contrasted sites around the River Rhone and for combinations of six crop and ten soil types. The simple scheme was found to reproduce well results obtained with the daily model at six additional verification sites. We applied the simple scheme to the assessment of irrigation requirements in the whole Swiss Rhone catchment. The results suggest seasonal requirements of 32 × 106 m3 per year on average over 1981–2009, half of which at altitudes above 1500 m. They also disclose a positive trend in the intensity of extreme events over the study period, with an estimated total IWR of 55 × 106 m3 in 2009, and indicate a 45% increase in water demand of grasslands during the 2003 European heat wave in the driest area of the studied catchment. In view of its simplicity, the approach can be extended to other applications, including assessments of the impacts of climate and land-use change.

  4. Attribution of Runoff Change for the Xinshui River Catchment on the Loess Plateau of China in a Changing Environment

    Directory of Open Access Journals (Sweden)

    Guoqing Wang

    2016-06-01

    Full Text Available Stream flow plays a crucial role in the environment, society, and the economy, and identifying the causes of changes in runoff is important to understanding the impact of climate change and human activity. This study examines the variation trends in recorded runoff for the Xinshui River, a tributary of the Yellow River on the Loess Plateau, and uses hydrological simulations to investigate how climate change and human activity have contributed to those trends. Results show that the recorded runoff at the Daning station on the Xinshui River declined significantly from 1955–2008 with an abrupt change occurring in 1973. The Simplified Water Balance Model (SWBM simulates monthly discharge well with a Nash–Sutcliffe efficiency (NSE coefficient of 78% and a relative error of volumetric fit (RE of 0.32%. Runoff depth over the catchment in 1973–2008 fell by 25.5 mm relative to the previous period, with human activity and climate change contributing 60.6% and 39.4% of the total runoff reduction, respectively. However, the impacts induced by climate change and human activities are both tending to increase. Therefore, efforts to improve the ecology of the Loess Plateau should give sufficient attention to the impacts of climate change and human activity.

  5. Trends and seasonality in stream water chemistry in two moorland catchments of the Upper River Wye, Plynlimon

    Directory of Open Access Journals (Sweden)

    B. Reynolds

    1997-01-01

    Full Text Available Stream water chemistry in the Cyff and Gwy subcatchments within the headwaters of the River Wye has been monitored regularly since 1980. In the Gwy, which is a predominantly semi-natural grassland catchment, land use has remained relatively static over the monitoring period, whilst the Cyff catchment is more buffered because of base cation inputs from agricultural improvement and ground water sources. Using a variety of statistical techniques, the long-term data are examined for evidence of trends after eliminating seasonal effects. The results highlight some of the difficulties associated with the analysis of longterm water quality data which show considerable variability over a variety of timescales. Some of this variability can be explained in terms of hydrochemical responses to climatic extremes and episodic events such as large atmospheric inputs of seasalts. The long-term fluctuations in solute concentration underline the continuing need for maintaining consistent long-term monitoring at sensitive upland sites if underlying trends related to gradual changes in pollutant deposition or climate are to be detected with any certainty.

  6. Contributions of Climate Variability and Human Activities to Runoff Changes in the Upper Catchment of the Red River Basin, China

    Directory of Open Access Journals (Sweden)

    Yungang Li

    2016-09-01

    Full Text Available Quantifying the effects of climate variability and human activities on runoff changes will contribute to regional water resource planning and management. This study aims to separate the effects of climate variability and human activities on runoff changes in the upper catchment of the Red River Basin in China. The Mann–Kendall test and Pettitt’s test methods were applied to identify the trends and change points of the hydro-meteorological variables. The hydrological sensitivity, climate elasticity and hydrological simulation methods were adopted to estimate the contributions of climate variability and human activities to runoff changes. Results showed that annual runoff significantly decreased by 1.57 mm/year during the period of 1961–2012. A change point in annual runoff coefficient occurred in 2002. Accordingly, the annual runoff series were divided into the baseline period (1961–2002 and the impacted period (2003–2012. Mean annual runoff of the impacted period decreased by 29.13% compared with the baseline period. Similar estimates of the contributions of climate variability and human activities were obtained by the three different methods. Climate variability was estimated to be responsible for 69%–71% of the reduction in annual runoff, and human activities accounted for 29%–31%. Climate variability was the main driving factor for runoff decrease in the catchment.

  7. Catchment-scale conservation units identified for the threatened Yarra pygmy perch (Nannoperca obscura in highly modified river systems.

    Directory of Open Access Journals (Sweden)

    Chris J Brauer

    Full Text Available Habitat fragmentation caused by human activities alters metapopulation dynamics and decreases biological connectivity through reduced migration and gene flow, leading to lowered levels of population genetic diversity and to local extinctions. The threatened Yarra pygmy perch, Nannoperca obscura, is a poor disperser found in small, isolated populations in wetlands and streams of southeastern Australia. Modifications to natural flow regimes in anthropogenically-impacted river systems have recently reduced the amount of habitat for this species and likely further limited its opportunity to disperse. We employed highly resolving microsatellite DNA markers to assess genetic variation, population structure and the spatial scale that dispersal takes place across the distribution of this freshwater fish and used this information to identify conservation units for management. The levels of genetic variation found for N. obscura are amongst the lowest reported for a fish species (mean heterozygosity of 0.318 and mean allelic richness of 1.92. We identified very strong population genetic structure, nil to little evidence of recent migration among demes and a minimum of 11 units for conservation management, hierarchically nested within four major genetic lineages. A combination of spatial analytical methods revealed hierarchical genetic structure corresponding with catchment boundaries and also demonstrated significant isolation by riverine distance. Our findings have implications for the national recovery plan of this species by demonstrating that N. obscura populations should be managed at a catchment level and highlighting the need to restore habitat and avoid further alteration of the natural hydrology.

  8. Inter-comparison of energy balance and hydrological models for land surface energy flux estimation over a whole river catchment

    DEFF Research Database (Denmark)

    Guzinski, R.; Nieto, H.; Stisen, S.

    2015-01-01

    Evapotranspiration (ET) is the main link between the natural water cycle and the land surface energy budget. Therefore water-balance and energy-balance approaches are two of the main methodologies for modelling this process. The water-balance approach is usually implemented as a complex, distribu...... derived with the energy-balance models, satellite based LST or another source) into the hydrological models. How this could be achieved and how to evaluate the improvements, or lack of thereof, is still an open research question.......-balance (TSEB) scheme, against a hydrological model, MIKE SHE, calibrated over the Skjern river catchment in western Denmark. The three models utilize different primary inputs to estimate ET (LST from different satellites in the case of remote sensing models and modelled soil moisture and heat flux in the case...

  9. Multifaceted value profiles of forest owner categories in south Sweden: the River Helge å catchment as a case study.

    Science.gov (United States)

    Richnau, Gustav; Angelstam, Per; Valasiuk, Sviataslau; Zahvoyska, Lyudmyla; Axelsson, Robert; Elbakidze, Marine; Farley, Joshua; Jönsson, Ingemar; Soloviy, Ihor

    2013-03-01

    Forest landscapes provide benefits from a wide range of goods, function and intangible values. But what are different forest owner categories' profiles of economic use and non-use values? This study focuses on the complex forest ownership pattern of the River Helge å catchment including the Kristianstad Vattenrike Biosphere Reserve in southern Sweden. We made 89 telephone interviews with informants representing the four main forest owner categories. Our mapping included consumptive and non-consumptive direct use values, indirect use values, and non-use values such as natural and cultural heritage. While the value profiles of non-industrial forest land owners and municipalities included all value categories, the forest companies focused on wood production, and the Swedish Environmental Protection Agency on nature protection. We discuss the challenges of communicating different forest owners' economic value profiles among stakeholders, the need for a broader suite of forest management systems, and fora for collaborative planning.

  10. Evaluation of water balance components in the Elbe river catchment simulated by the regional climate model CCLM

    Directory of Open Access Journals (Sweden)

    Jan Volkholz

    2014-12-01

    Full Text Available For investigations of feedbacks between the hydrological cycle and the climate system, we assess the performance of the regional climate model CCLM in reconstructing the water balance of the Elbe river catchment. To this end long-term mean precipitation, evapotranspiration and runoff are evaluated. Extremes (90th percentile are also considered in the case of precipitation. The data are provided by a CCLM present-day simulation for Europe that was driven by large-scale global reanalyses. The quality of the model results is analyzed with respect to suitable reference data for the period 1970 to 1999. The principal components of the hydrological cycle and their seasonal variations were captured well. Basin accumulated, averaged daily precipitation, evapotranspiration and runoff differ by no more than 10 % from observations. Larger deviations occur mainly in summer, and at specific areas.

  11. Suspended sediment flux modeling with artificial neural network: An example of the Longchuanjiang River in the Upper Yangtze Catchment, China

    Science.gov (United States)

    Zhu, Yun-Mei; Lu, X. X.; Zhou, Yue

    2007-02-01

    Artificial neural network (ANN) was used to model the monthly suspended sediment flux in the Longchuanjiang River, the Upper Yangtze Catchment, China. The suspended sediment flux was related to the average rainfall, temperature, rainfall intensity and water discharge. It is demonstrated that ANN is capable of modeling the monthly suspended sediment flux with fairly good accuracy when proper variables and their lag effect on the suspended sediment flux are used as inputs. Compared with multiple linear regression and power relation models, ANN can generate a better fit under the same data requirement. In addition, ANN can provide more reasonable predictions for extremely high or low values, because of the distributed information processing system and the nonlinear transformation involved. Compared with the ANNs that use the values of the dependent variable at previous time steps as inputs, the ANNs established in this research with only climate variables have an advantage because it can be used to assess hydrological responses to climate change.

  12. Environmental health outcomes and exposure risks among at-risk communities living in the Upper Olifants River Catchment, South Africa.

    Science.gov (United States)

    John, Juanette; Wright, Caradee Yael; Oosthuizen, Maria Aletta; Steyn, Maronel; Genthe, Bettina; le Roux, Wouter; Albers, Patricia; Oberholster, Paul; Pauw, Christiaan

    2014-01-01

    Potential exposure to water and air pollution and associated health impacts of three low-income communities in the Upper Olifants River Catchment, South Africa, was investigated through a cross-sectional epidemiological study comprising a household survey. Water samples were collected and analysed for microbial indicators and pathogens. Ambient air-monitoring included some of the criteria pollutants, as well as mercury and manganese. Associations between environmental exposure and health outcomes were analysed by means of logistic regression. Despite poor water and air quality episodes, the communities' self-perceived health was good with relatively low prevalence of reported health outcomes. Hygiene practices with respect to water collection and storage were often poor, and most likely contributed to the regularly contaminated water storage containers. Community proximity to the polluted stream was associated with increased prevalence in adverse health outcomes. This paper reports on preliminary results and additional multivariate analyses are necessary to further understand study results.

  13. Land use and land cover change detection in Karinca river catchment (NW Turkey) using GIS and RS techniques.

    Science.gov (United States)

    Efe, Recep; Soykan, Abdullah; Curebal, Isa; Sonmez, Suleyman

    2012-04-01

    The basin of Karinca river, in the north-west of Turkey, covers an area of 29,840 ha. Pronounced changes in land use emerged as a result of the development of activities in the tourism sector in Turkey in the 1970's. The basin has been significantly affected in the course of this process. This study was conducted in order to determine the land use changes (as well as the type of changes and their direction) occurring in the use of land in the Karinca river catchment for the period 1979-2007. The geographical data were gathered by using 1:25000 scale topographical maps as a basis. Thus, the existing soil and land use data from 1979 were processed on these bases and the the main materials rendering the land use were produced. Geometric verification was made by putting the previously prepared bases onto landsat ETM+ and satellite images of 2007. In the final stage, results pertaining to the changes in land use were obtained by overlapping the two sets of data. All processes were done using the ArcGIS Desktop v9.x program. According to the data of the year 1979, the catchment area consisted of 43.4% forest, 26.5% grassland, 18.3% olive groves, 10.6% agriculture and 1.2% built-up lands. Comparing these coverage with the data of 2007, show a clear shift among residential areas, olive groves and forest terrain. It was found that the agricultural areas, particularly along the shoreline, were converted into resort houses and that the olive groves (the dominant land use) shifted from lower regions to its upper sectors. All these changes caused loss of natural habitats leading to degradation.

  14. Alien freshwater polychaetes Hypania invalida (Grube 1860 and Laonome calida Capa 2007 in the Upper Odra River (Baltic Sea catchment area

    Directory of Open Access Journals (Sweden)

    Pabis Krzysztof

    2017-01-01

    Full Text Available Two polychaete species, Hypania invalida and Laonome calida, were found in the Upper Odra River in 2016. Both species were recorded close to a natural river bank down to 1 m depths. They inhabited sandy-gravelly and sandy-muddy sediments. H. invalida is an alien invasive Ponto-Caspian species, previously known in Poland from the Odra River estuary only. Our results may indicate a further rapid dispersal of H. invalida upstream the Odra River or an accidental introduction. This study is the first record of L. calida in the Baltic Sea catchment. This Australian species has been recently introduced into Europe. Prior to this study, it had been reported from Dutch rivers only. The present data suggest accidental introduction of the species to European rivers; however, our findings show an urgent need for a close monitoring of the polychaete in Europe.

  15. Physical-chemical modeling of elements' behavior in mixing sea and fresh waters of minor rivers in the White Sea catchment area.

    Science.gov (United States)

    Maksimova, Victoria V; Mazukhina, Svetlana I; Cherepanova, Tatiana A; Gorbacheva, Tamara T

    2017-07-29

    The physical-chemical stage of marginal filters in minor rivers of the White Sea catchment area by the example of the Umba River, flowing to Kandalaksha Gulf, has been explored. Application of the method of physical-chemical modeling on the basis of field data allowed establishing migration forms of a number of elements in the "river-sea" system and deposition of solid phases when mixing waters. The mixing of river and sea water is accompanied by the sedimentation of predominantly goethite, hydromuscovite, and hydroxylapatite. Sediments in mixing river and sea waters were found to be mainly composed by goethite, hydromuscovite, and hydroxylapatite. The research has added to the knowledge of the role of the abiotic part in the marginal filters of small rivers in the Arctic.

  16. The dispersal of metal mining wastes in the catchment of the river Geul (Belgium - The Netherlands)

    NARCIS (Netherlands)

    Leenaers, H.

    1989-01-01

    The metal mining industry has caused large quantities of heavy metals to enter countless river systems. The consequent spread of heavy metals is determined largely by how these metals bind with silt and soil particles and the transport pathways of these particles in the alluvial parts of river syste

  17. The dispersal of metal mining wastes in the catchment of the river Geul (Belgium - The Netherlands)

    NARCIS (Netherlands)

    Leenaers, H.

    1989-01-01

    The metal mining industry has caused large quantities of heavy metals to enter countless river systems. The consequent spread of heavy metals is determined largely by how these metals bind with silt and soil particles and the transport pathways of these particles in the alluvial parts of river

  18. Understanding triggers and dynamics of wood-laden flash floods in mountain catchments: examples from the Zulg River (Switzerland)

    Science.gov (United States)

    Ruiz-Villanueva, Virginia; Galatiotto, Niccolo; Bürkli, Livia; Stoffel, Markus

    2017-04-01

    Mountain rivers are prone to flash floods, and in forested basins, large quantities of wood can be moved and transported long distances downstream during such events. Under certain circumstances, congested transport of wood may result in wood-laden flows in which a large number of logs form a mass moving together with the flow and thus alter its dynamics. This process could significantly increase the flood hazard and risk, however, the knowledge about the formation of these wood-laden flows is still very limited. The Zulg River (23 km long and 89 km2 drainage area) is located in the Swiss Prealps in the canton of Bern (Switzerland). In the Zulg catchment, heavy local precipitation usually leads to a fast reaction of the water level downstream and very often flash floods are transporting significant volume of wood. There are several bridges crossing the river at the area of Steffisburg and downstream of this town the Zulg flows into the Aare River that crosses the city of Bern few kilometres downstream. Therefore, a better understanding of these processes will help to improve the flood risk management of the region. In this work we are analysing four recent floods (i.e., 2012, 2013, 2015 and 2016) with significant wood transport and the goal is to decipher the triggering and formation of the wood-laden flash floods. We collected aerial pictures from before and after each flood to map the pre- and post-flood conditions and mapped riverscape units, landslides and the wood logs and jams already deposited along the river channel. The forest stand volumes recruited during the events is analysed based on the land use maps available and provided by the Cantonal Forest Service. We also analysed movies taken by witnesses during these flash flood events, which may potentially provide highly valuable information (i.e., the amount and type of wood in motion or what was roughly the velocity and direction of the water) to quantify wood fluxes. However, the usage of these home

  19. Coupling river hydrochemical information with catchment properties for multi-scale-analysis of lateral matter fluxes in the Earth system

    Science.gov (United States)

    Hartmann, Jens; Lauerwald, Ronny; Moosdorf, Nils

    2016-04-01

    Over the last decade the number of regional to global scale studies of river chemical fluxes and their steering factors increased rapidly, entailing a growing demand for appropriate databases to calculate mass budgets, to calibrate models, or to test hypotheses [1, 2]. Research applying compilations of hydrochemical data are related to questions targeting different time and spatial scales, as for example the annual to centennial scale. In focus are often the alteration of land-ocean matter fluxes due anthropogenic disturbance, the climate sensitivity of chemical weathering fluxes [3], or nutrient fluxes and their evolution [2, 4]. We present an overview of the GLObal RIver CHemistry database GLORICH, which combines an assemblage of hydrochemical data from varying sources with catchment characteristics of the sampling locations [1]. The information provided include e.g. catchment size, lithology, soil, climate, land cover, net primary production, population density and average slope gradient. The data base comprises 1.27 million samples distributed over 17,000 sampling locations [1]. It will be shown how large assemblages of data are useful to target some major questions about the alteration of land ocean element fluxes due to climate or land use change while coupling hydrochemical data with catchment properties in a homogenized database. An extension by isotopic data will be in the focus of future work [c.f. 5]. Further, applications in climate change studies for understanding feedbacks in the Earth system will be discussed [6]. References: [1] Hartmann, J., Lauerwald, R., & Moosdorf, N. (2014). A brief overview of the GLObal RIver CHemistry Database, GLORICH. Procedia Earth and Planetary Science, 10, 23-27. [2] Hartmann, J., Levy, J., & Kempe, S. (2011). Increasing dissolved silica trends in the Rhine River: an effect of recovery from high P loads?. Limnology, 12(1), 63-73. [3] Hartmann, J., Moosdorf, N., Lauerwald, R., Hinderer, M., & West, A. J. (2014). Global

  20. A critical re-evaluation of controls on spatial and seasonal variations in nitrate concentrations in river waters throughout the River Derwent catchment in North Yorkshire, UK.

    Science.gov (United States)

    Begum, Shaheen; Adnan, Muhammad; McClean, Colin J; Cresser, Malcolm S

    2016-05-01

    Since mean nitrate concentration along single river channels increases significantly with percent arable land use upstream of sampling points and autumn/early winter flushes in nitrate concentration are widespread, it is generally concluded that farmers contribute most of the nitrate. For the River Derwent in North Yorkshire, the correlation between nitrate concentration and percent arable land use is much poorer when tributary data are included in the equation, because of greater variations in dilution by water draining upland areas and in other N input sources. For the whole river system therefore, percent upland moorland/rough grazing land cover is an appreciably better predictor than percent arable land use for nitrate concentration. Upland land use encompasses the higher precipitation and runoff in such areas, and the subsequent greater dilution downstream of both arable land runoff and effluent from treatment works, as well as an inverse correlation to percent arable land use. This is strongly supported by the observation that, for the Derwent, Meteorological Office rainfall data alone proved even better than percent moorland rough grazing for predicting nitrate concentration. The dilution effect is therefore substantial but highly seasonal; lower runoff and dilution in summer offset the lower leaching losses from arable land, and higher dilution and runoff in winter offset greater nitrate leaching losses from arable soils. Because of this, coupled to improved efficiency of nitrogen fertilizer use, seasonality trends in nitrate concentrations that were pronounced a decade ago now have all but disappeared in the catchment.

  1. TEMPORAL AND SPATIAL DYNAMICS OF DIFFERENT PARTICLE SIZE OF SUSPENDED SEDIMENT IN THE LIU RIVER CATCHMENTS,CHINA

    Institute of Scientific and Technical Information of China (English)

    Haoming FAN; Qiangguo CAI; Chengjiu GUO; Tieliang WANG

    2006-01-01

    This paper presents information on the particle size characteristics of suspended sediment transported by the Liu River, which has the most serious erosion and sedimentation problems in the northeast of China. The median (d50) particle size for the individual stations on the Liu River ranged from 0.0343 to 0.0588 mm. Particles <0.01 mm ranged from 15.4 to 33.3% and >0.05 mm of ranged from 24.3 to 53.7%. Spatial and temporal variations were noticeable in the particle size composition of suspended sediment within the study basins. At different locations the sediment particles size varies as a result of differences in catchment characteristics. The preferential deposition of the coarser size fractions has resulted in downstream fining of the suspended sediment load. In the flood season the suspended sediment particle size was finer than that in low flow season. The relations among water discharge, suspended sediment concentration, and sediment particle size are complicated. At small water discharge or suspended sediment concentration, with the increase of water discharge or sediment concentration the particle size of suspended sediment decreases to a minimum. However, when the water discharge or sediment concentration exceed certain threshold values (turning points) the particle size increases or remains constant with the increase of water discharge or sediment concentration. The tuning points are different in different rivers. Thus, their relations are double-valued. The negative relation between suspended sediment particle size and flow discharge reflects the importance of supply conditions and the positive relation reflects that the flow and hydraulics take a greater role in sediment transportation. On the whole, variation of the sediment particle size is subject to many factors such as the hydraulic conditions, the type and extent of erosion, human activities, vegetation coverage, hydraulic projects, and sediment supply. The findings reported in this paper

  2. Characterization of Amazonian forest fragments in the catchment of the Taxidermista I River in Alta Floresta, MT

    Directory of Open Access Journals (Sweden)

    Carlos José da Silva

    2013-11-01

    Full Text Available Maintaining the connectivity of the remaining forest in the state of Mato Grosso is critically important, and the preservation of riparian vegetation of streams contributes greatly to retaining the integrity of the mosaic of habitats found in this region. The aim of this study was to characterize the Amazonian forest fragments remaining in the catchment of the Taxidermista I River, in Alta Floresta, MT, in order to provide input for the implementation of recovery projects in degraded areas and the conservation of forest fragments. The forest fragments were vectorized and the size, perimeter, and distance of each fragment to the nearest watercourse were evaluated. The circularity index, or the edge/interior ratio, was also determined. In the watershed of the Taxidermista I River, 63 forest fragments ranging in size from 0.44 to 67.51 ha, with perimeters between 262.67 and 4756.26 m, were recorded. The distance from each forest fragment to the nearest watercourse ranges from 0 to 450 m; however, 71.4% of the fragments are connected to a watercourse. The majority of the fragments in this watershed are elongated and occupy a small area, but their perimeter/edge is large relative to their size, which makes them susceptible to edge effects, especially from nearby cattle farms.

  3. Long term effect of metal pollution in the catchment area of Tisza River

    Directory of Open Access Journals (Sweden)

    Zoltán Győri

    2013-01-01

    Full Text Available In January and March 2000 two tailings dam failures occurred in the upper Tisza catchment area near Baia Mare and Baia Borsa (Romania. These accidents focused attention on the metal pollution of the Tisza catchment area, and the short term effects of them were studied by many researchers. The aim of this study was to evaluate the long term effects of these pollutions by determining the Lakanen-Erviö extractable easily available metal contents of samples collected in 2011 from floodplains and pastures along the Tisza (Tivadar, Vásárosnamény, Rakamaz, Tiszacsege, and comparing them to our earlier results. Cu and Zn contents were measured by Optima 3300 DV ICP-OES (Perkin-Elmer. The measurement of Pb and Cd was conducted by QZ 939 GF-AAS (Unicam in 2000 and by an X7 ICP-MS (Thermo Fisher in 2011. We found that the Cd, Zn and Pb contents of the pasture near Vásárosnamény exceed limit values and natural background values. In addition, during a 11 year period the easily available Cd, Zn and Pb contents increased significantly, suggesting that the hazard of this pollution should not be neglected.

  4. Origin of groundwater salinity in the Sandspruit catchment, Berg River basin (South Africa)

    CSIR Research Space (South Africa)

    Demlie, M

    2011-09-01

    Full Text Available of the Berg River, Klipplaat and Moorreesburg Formations, which together constitute the Swartland Subgroup (Gresse et al. 2006). The Berg River Formation is composed of chlorite schist, greywacke with impure limestone lenses and quartz schist towards the top.... The contact with the overlying Klipplaat Formation is placed just above a strongly deformed, ferruginous, cherty quartzite or the uppermost limestone layer. The Klipplaat Formation is essentially quartz schist, consisting of quartz, Seri cite and chlorite...

  5. Decadal oscillations and extreme value distribution of river peak flows in the Meuse catchment

    Science.gov (United States)

    De Niel, Jan; Willems, Patrick

    2017-04-01

    In flood risk management, flood probabilities are often quantified through Generalized Pareto distributions of river peak flows. One of the main underlying assumptions is that all data points need to originate from one single underlying distribution (i.i.d. assumption). However, this hypothesis, although generally assumed to be correct for variables such as river peak flows, remains somehow questionable: flooding might indeed be caused by different hydrological and/or meteorological conditions. This study confirms these findings from previous research by showing a clear indication of the link between atmospheric conditions and flooding for the Meuse river in The Netherlands: decadal oscillations of river peak flows can (at least partially) be attributed to the occurrence of westerly weather types. The study further proposes a method to take this correlation between atmospheric conditions and river peak flows into account when calibrating an extreme value distribution for river peak flows. Rather than calibrating one single distribution to the data and potentially violating the i.i.d. assumption, weather type depending extreme value distributions are derived and composed. The study shows that, for the Meuse river in The Netherlands, such approach results in a more accurate extreme value distribution, especially with regards to extrapolations. Comparison of the proposed method with a traditional extreme value analysis approach and an alternative model-based approach for the same case study shows strong differences in the peak flow extrapolation. The design-flood for a 1,250 year return period is estimated at 4,800 m3s-1 for the proposed method, compared with 3,450 m3s-1 and 3,900 m3s-1 for the traditional method and a previous study. The methods were validated based on instrumental and documentary flood information of the past 500 years.

  6. River Suspended Sediment and Particulate Organic Carbon Transport in Two Montane Catchments in the Luquillo Critical Zone Observatory of Puerto Rico over 25 years: 1989 to 2014

    Science.gov (United States)

    Clark, K. E.; Plante, A. F.; Willenbring, J. K.; Jerolmack, D. J.; Gonzalez, G.; Stallard, R. F.; Murphy, S. F.; Vann, D. R.; Leon, M.; McDowell, W. H.

    2015-12-01

    Physical erosion in mountain catchments mobilizes large amounts of sediment, while exporting carbon and nutrients from forest ecosystems. This study expands from previous studies quantifying river suspended sediment and particulate organic carbon loads in the Luquillo Critical Zone Observatory, in Puerto Rico. We evaluate the influences on river suspended load due to i) underlying basin geology, ii) hillslope debris and biomass supply, and iii) hurricanes and large storms. In the Mameyes and Icacos catchments of the Luquillo Mountains, we estimate suspended sediment and particulate organic carbon yields over a 25-year period using streamflow discharge determined from stage measurements at 15-intervals, with estimates of discharge replacing gaps in data, and over 3000 suspended sediment samples. We estimate variation in suspended sediment loads over time, and examine variation in particulate organic carbon loads. Mass spectrometry was used to determine organic carbon concentrations. We confirm that higher suspended sediment fluxes occurred i) in the highly weathered quartz diorite catchment rather than the predominantly volcaniclastic catchment, ii) on the rising limb of the hydrograph once a threshold discharge had been reached, and iii) during hurricanes and other storm events, and we explore these influences on particulate organic carbon transport. Transport of suspended sediment and particulate organic carbon in the rivers shows considerable hysteresis, and we evaluate the extent to which hysteresis affects particulate fluxes over time and between catchments. Because particulate organic carbon is derived from the critical zone and transported during high flow, our research highlights the role of major tropical storms in controlling carbon storage in the critical zone and the coastal ocean.

  7. Dry spells assessment with reference to the maize crop in the Luvuvhu River catchment of South Africa

    Science.gov (United States)

    Masupha, Teboho Elisa; Moeletsi, Mokhele Edmond; Tsubo, Mitsuru

    2016-04-01

    Agricultural productivity in South Africa is negatively affected by drought as a result of frequent periodic dry spells and increasing crop water demands resulting in poor crop development and low yields. Thus, we embarked on this study which aims at investigating dry spell occurrences in relation to growing season of maize in the Luvuvhu River Catchment. Daily rainfall data (1945-2014) from 12 stations which represent the catchment fairly well was utilized in this study. Three consecutive planting dates were staggered based on three consecutive onsets of the rainy season. Dry spells were categorized into three groups: short, medium and long dry spells. The data was then subjected to theoretical distribution fitting using the Anderson-Darling goodness-of-fit test; and probabilities of occurrence were computed using a probabilistic model that best fits the data. Trend analysis was performed on the frequency of dry spells per growing period using the non-parametric Spearman's rank correlation test. Out results indicated high probabilities (≥80%) of short dry spells at all the stations irrespective of the timing of planting. Further analysis revealed that a risk of yield reduction with planting following the first onset of rains was higher than that with planting following the second and third onsets. In order to minimize this risk, farmers can be advised to plant between mid-November to mid-December. Trend analysis indicated no trend for all the various dry spell lengths except for Thohoyandou with a decreasing trend and Sigonde with a weak increasing trend in long dry spells. Such findings can be used to describe drought conditions for improvement of agricultural productivity and food security, in a given area.

  8. Effects of River Discharge and Land Use and Land Cover (LULC) on Water Quality Dynamics in Migina Catchment, Rwanda

    Science.gov (United States)

    Uwimana, Abias; van Dam, Anne; Gettel, Gretchen; Bigirimana, Bonfils; Irvine, Kenneth

    2017-09-01

    Agricultural intensification may accelerate the loss of wetlands, increasing the concentrations of nutrients and sediments in downstream water bodies. The objective of this study was to assess the effects of land use and land cover and river discharge on water quality in the Migina catchment, southern Rwanda. Rainfall, discharge and water quality (total nitrogen, total phosphorus, total suspended solids, dissolved oxygen, conductivity, pH, and temperature) were measured in different periods from May 2009 to June 2013. In 2011, measurements were done at the outlets of 3 sub-catchments (Munyazi, Mukura and Akagera). Between May 2012 and May 2013 the measurements were done in 16 reaches of Munyazi dominated by rice, vegetables, grass/forest or ponds/reservoirs. Water quality was also measured during two rainfall events. Results showed seasonal trends in water quality associated with high water flows and farming activities. Across all sites, the total suspended solids related positively to discharge, increasing 2-8 times during high flow periods. Conductivity, temperature, dissolved oxygen, and pH decreased with increasing discharge, while total nitrogen and total phosphorus did not show a clear pattern. The total suspended solids concentrations were consistently higher downstream of reaches dominated by rice and vegetable farming. For total nitrogen and total phosphorus results were mixed, but suggesting higher concentration of total nitrogen and total phosphorus during the dry and early rainy (and farming) season, and then wash out during the rainy season, with subsequent dilution at the end of the rains. Rice and vegetable farming generate the transport of sediment as opposed to ponds/reservoir and grass/forest.

  9. Flood-initiating catchment conditions: a spatio-temporal analysis of large-scale soil moisture patterns in the Elbe river basin

    Directory of Open Access Journals (Sweden)

    M. Nied

    2012-09-01

    Full Text Available Floods are the result of a complex interaction between meteorological event characteristics and pre-event catchment conditions. While the large-scale meteorological conditions have been classified and successfully linked to floods, this is lacking for the large-scale pre-event catchment conditions. Therefore, we propose to classify soil moisture as a key variable of pre-event catchment conditions and to investigate the link between soil moisture patterns and flood occurrence in the Elbe river basin. Soil moisture is simulated using a semi-distributed conceptual rainfall-runoff model over the period 1951–2003. Principal component analysis (PCA and cluster analysis are applied successively to identify days of similar soil moisture patterns. The results show that PCA considerably reduced the dimensionality of the soil moisture data. The first principal component (PC explains 75.71% of the soil moisture variability and represents the large-scale seasonal wetting and drying. The successive PCs express the spatial heterogeneous antecedent catchment conditions. By clustering the leading PCs, we detected large-scale soil moisture patterns which frequently occur before the onset of floods. In winter floods are initiated by overall high soil moisture content whereas in summer the flood initiating soil moisture patterns are diverse and less stable in time. The results underline the importance of large-scale pre-event catchment conditions in flood initiation.

  10. Uncertainty result of biotic index in analysing the water quality of Cikapundung river catchment area, Bandung

    Science.gov (United States)

    Surtikanti, Hertien Koosbandiah

    2017-05-01

    The Biotic Index was developed in Western Countries in response to the need in water quality evaluation. This method analysis is based on the classification of aquatic macrobenthos as a bioindicator for clean and polluted water. The aim of this study is to compare the analysis of Cikapundung river using 6 different Biotic Indexes. BI Shannon-Weiner, Belgian Biological Index (BBI), Family Biotic Index (FBI), Biological Monitoring Working Party (BMWP), Biological Monitoring Working Party-Average Score Per Taxon (BMWP-ASPT), and A Scoring System for Macroinvertebrate in Australian River (A SIGNAL). Those analysis are compared with Physical Water Index (CPI) which is developed in Indonesia. The result shows that a decreasing water quality is detected upstream to downstream of Cikapundung River. However, based on the CPI analysis result, the BMWP-ASPT biotic index analysis is more comprehensive than other BI in explaining Cikapundung water quality.

  11. Coupling urban event-based and catchment continuous modelling for combined sewer overflow river impact assessment

    Science.gov (United States)

    Andrés-Doménech, I.; Múnera, J. C.; Francés, F.; Marco, J. B.

    2010-10-01

    Since Water Framework Directive (WFD) was passed in year 2000, the conservation of water bodies in the EU must be understood in a completely different way. Regarding to combined sewer overflows (CSOs) from urban drainage networks, the WFD implies that we cannot accept CSOs because of their intrinsic features, but they must be assessed for their impact on the receiving water bodies in agreement with specific environmental aims. Consequently, both, urban system and the receiving water body must be jointly analysed to evaluate the environmental impact generated on the latter. In this context, a coupled scheme is presented in this paper to assess the CSOs impact on a river system in Torrelavega (Spain). First, a urban model is developed to statistically characterise the CSOs frequency, volume and duration. The main feature of this first model is the fact of being event-based: the system is modelled with some built synthetic storms which cover adequately the probability range of the main rainfall descriptors, i.e., rainfall event volume and peak intensity. Thus, CSOs are characterised in terms of their occurrence probability. Secondly, a continuous and distributed basin model is built to assess river response at different points in the river network. This model was calibrated initially on a daily scale and downscaled later to hourly scale. The main objective of this second element of the scheme is to provide the most likely state of the receiving river when a CSO occurs. By combining results of both models, CSO and river flows are homogeneously characterised from a statistical point of view. Finally, results from both models were coupled to estimate the final concentration of some analysed pollutants (biochemical oxygen demand, BOD, and total ammonium, NH4+), within the river just after the spills.

  12. Coupling urban event-based and catchment continuous modelling for combined sewer overflow river impact assessment

    Directory of Open Access Journals (Sweden)

    I. Andrés-Doménech

    2010-10-01

    Full Text Available Since Water Framework Directive (WFD was passed in year 2000, the conservation of water bodies in the EU must be understood in a completely different way. Regarding to combined sewer overflows (CSOs from urban drainage networks, the WFD implies that we cannot accept CSOs because of their intrinsic features, but they must be assessed for their impact on the receiving water bodies in agreement with specific environmental aims. Consequently, both, urban system and the receiving water body must be jointly analysed to evaluate the environmental impact generated on the latter. In this context, a coupled scheme is presented in this paper to assess the CSOs impact on a river system in Torrelavega (Spain. First, a urban model is developed to statistically characterise the CSOs frequency, volume and duration. The main feature of this first model is the fact of being event-based: the system is modelled with some built synthetic storms which cover adequately the probability range of the main rainfall descriptors, i.e., rainfall event volume and peak intensity. Thus, CSOs are characterised in terms of their occurrence probability. Secondly, a continuous and distributed basin model is built to assess river response at different points in the river network. This model was calibrated initially on a daily scale and downscaled later to hourly scale. The main objective of this second element of the scheme is to provide the most likely state of the receiving river when a CSO occurs. By combining results of both models, CSO and river flows are homogeneously characterised from a statistical point of view. Finally, results from both models were coupled to estimate the final concentration of some analysed pollutants (biochemical oxygen demand, BOD, and total ammonium, NH4+, within the river just after the spills.

  13. Coupling urban event-based and catchment continuous modelling for combined sewer overflow river impact assessment

    Directory of Open Access Journals (Sweden)

    I. Andrés-Doménech

    2010-05-01

    Full Text Available Since the Water Framework Directive (WFD was passed in year 2000, the protection of water bodies in the EU must be understood in a completely different way. Regarding to combined sewer overflows (CSOs from urban drainage networks, the WFD implies that CSOs cannot be accepted because of their intrinsic features, but must be assessed for their impact on the receiving water bodies in agreement with specific environmental aims. Consequently, both, the urban system and the receiving one must be jointly analysed to evaluate their impact. In this context, a coupled scheme is presented in this paper to assess the CSOs impact in a river system in Torrelavega (Spain. First, an urban model is developed to characterise statistically the CSOs frequency, volume and duration. The main feature of this first model is the fact of being event-based: the system is modelled with some built synthetic storms which cover adequately the probability range of the main rainfall descriptors, i.e., rainfall event volume and peak intensity. Thus, CSOs are characterised in terms of their occurrence probability. Secondly, a continuous and distributed basin model is built to assess the river response at different points in the river network. This model was calibrated initially on a daily scale and downscaled later to the hourly scale. The main objective of this second element of the scheme is to provide the most likely state of the receiving river when a CSO occurs. By combining results of both models, CSO and river flows are homogeneously characterised from a statistical point of view. Finally, results from both models were coupled to estimate the final concentration of some analysed pollutants (the biochemical oxygen demand, BOD, and the total ammonium, NH4+, in the river just after the spills.

  14. SURFACE WATER POLLUTION WITH HEAVY METALS IN THE LOWER CATCHMENT OF JIU RIVER BASIN, ACCORDING TO THE WATER FRAMEWORK DIRECTIVE (2000/60/EC

    Directory of Open Access Journals (Sweden)

    ADINA SANDA ŞERBAN

    2011-03-01

    Full Text Available Surface water pollution with heavy metals in the lower catchment of Jiu river basin, according to the Water Framework Directive (2000/60/EC. The Water Framework Directive establishes a single transparent, effective and coherent water policy by defining a strategy to combat pollution by requiring specific action programs.Chemical pollution of surface water presents a threat to the aquatic environment with acute and chronic toxicity to aquatic organisms, accumulation in the ecosystem and losses of habitats and biodiversity, as well as a threat to human health (art.1 from Directive 2008/105/EC regarding the environmental quality standards for water policy.The purpose of this study is to evaluate the chemical status for surface water bodies in the lower catchment of Jiu river basin. The assessment was made taking into account the water impact of four heavy metals: cadmium (Cd, nickel (Ni, mercury (Hg and lead (Pb.

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

    Science.gov (United States)

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

    2016-01-01

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

  16. Neural Network Model for Prediction of Discharged from the Catchments of Langat River, Malaysia

    OpenAIRE

    2010-01-01

    Artificial neural networks have been shown to be able to approximate any continuous non-linear functions and have been used to build data base empirical models for non-linear processes. In this study, neural networks models were used to model the daily river flows or discharged in Langat River, Malaysia. Two possible ways of modelling were implemented which is by time series prediction and by the dynamics function of the system which include the past value of the discharged and also th...

  17. Water level and response time of rivers during flash floods derived from a nested network in the Claduègne Mediterranean catchment (43 km2)

    Science.gov (United States)

    Gonzalez-Sosa, Enrique; Braud, Isabelle; Molinié, Gilles; Nord, Guillaume; Vandervaere, Jean-Pierre; Uber, Magdalana

    2016-04-01

    time (time between the initiation of rainfall and a significant water level rise) and rising time (time between the water level significant rise and peak water level) were derived. The results are impacted by the cross sections of the river. Some events show that the reaction and rising time follow an expected upstream-downstream propagation into the river network, while, for other events, this is not the case independently of homogeneity and spatial distribution of precipitation cells. Statistical analyses were also performed to search for relationships between rainfall characteristics, antecedent soil moisture, catchments characteristics and the hydrological response. The results of the analysis are also used to assess the validity of the underlying physical hypotheses of the IRIP method (Intense Pluvial Runoff Indicators, Lagadec et al., 2016) allowing the mapping of areas prone to runoff generation, transfer and accumulation. References Braud et al., 2014. Multi-scale hydrometeorological observation and modelling for flash-flood understanding, Hydrology and Earth System Sciences, 18, 3733-376. Lagadec et al., 2016. Description and evaluation of an intense surface runoff susceptibility mapping method, J. Hydrology, in revision. Nord et al., in prep. A high space-time resolution dataset linking meteorological forcing and hydro-sedimentary response in a masoscale Mediterranean catchment (Auzon) of the Ardèche regione, France, Earth Systems Sciences Data.

  18. Characteristic of water level changes in river-bed during the 2012 drought in context of ground water levels in a small catchment

    Science.gov (United States)

    Wasilewicz, Michał; Kaznowska, Ewa; Hejduk, Leszek

    2014-05-01

    The objective of this paper is to characterize the water level changes in river bed during the 2012 drought, in the context of ground water levels in the catchment. During the growing season , and long- lasting lack of precipitation causes atmospheric drought. Prolonged lack of precipitation causes depletion of water resources in the saturated zone . Groundwater recharge of rivers decreases , and hence streamflow droughts (summer droughts) occur, which is identified as hydrological droughts. In the phase of hydrological drought a much stronger relationship between surface and ground waters is observed. The study area is the Zagożdżonka river. The Zagożdzonka catchment is situated in the strip of the Central Polish Lowlands, in the region where droughts are the most frequent. The basin is the research area of the Department of Hydraulic Engineering of WUoLS-SGGW in Warsaw. It is one of the few catchments in Poland, with long-term records of rainfall and runoff occurrences. Hydrometeorological measurements are carried out from July 1962. The catchment area is mainly covered by one Quaternary aquifer . Quaternary layer is composed mostly of Pleistocene sands and gravels, with thickness from 4 to 40 m. Aquifer is at a depth of 1 to 12 m below ground level and is unconfined and fed by direct infiltration of precipitation. The Zagożdżonka river is the main drainage in the local hydrologic cycle. There is a strong relationship between surface waters and occurring in the Quaternary sediments. In the hydrological year 2012 hydrological and atmospheric drought occurred. The duration and deficit of streamflow drought ( defined by with the Q90 % truncation level) in 2012 was three time greater than the average value from the multi-annual period, which influenced the groundwater level fluctuations. Acknowledgment The paper has been prepared with financial support by a grant from National Science Centre

  19. SURFACE WATER POLLUTION WITH HEAVY METALS IN THE LOWER CATCHMENT OF JIU RIVER BASIN, ACCORDING TO THE WATER FRAMEWORK DIRECTIVE (2000/60/EC)

    OpenAIRE

    ADINA SANDA ŞERBAN

    2011-01-01

    Surface water pollution with heavy metals in the lower catchment of Jiu river basin, according to the Water Framework Directive (2000/60/EC). The Water Framework Directive establishes a single transparent, effective and coherent water policy by defining a strategy to combat pollution by requiring specific action programs.Chemical pollution of surface water presents a threat to the aquatic environment with acute and chronic toxicity to aquatic organisms, accumulation in the ecosystem and losse...

  20. Assessing climate change impacts on river flows and environmental flow requirements at catchment scale

    DEFF Research Database (Denmark)

    Gül, G.O.; Rosbjerg, Dan; Gül, A.

    2010-01-01

    mostly at the local scale. though potential changes in the hydrological cycle and eco-hydrological processes are more difficult to model and analyse at this level. The difficulty is even greater for studies on lowland river systems, which require the modelling of hydrological processes in greater detail...

  1. Stable oxygen isotope variability in two contrasting glacier river catchments in Greenland

    DEFF Research Database (Denmark)

    Yde, Jacob C.; Knudsen, Niels T.; Steffensen, Jørgen P.

    2016-01-01

    subglacial drainage network in the upper part of the glacier. At the Kuannersuit Glacier river on the island Qeqertarsuaq in west Greenland, the δ18O characteristics were examined after the major 1995-1998 glacier surge event. The mean annual δ18O was -19.47±0.55 ‰. Despite large spatial variations in the δ...

  2. Hydrology of the North Klondike River: carbon export, water balance and inter-annual climate influences within a sub-alpine permafrost catchment.

    Science.gov (United States)

    Lapp, Anthony; Clark, Ian; Macumber, Andrew; Patterson, Tim

    2017-10-01

    Arctic and sub-arctic watersheds are undergoing significant changes due to recent climate warming and degrading permafrost, engendering enhanced monitoring of arctic rivers. Smaller catchments provide understanding of discharge, solute flux and groundwater recharge at the process level that contributes to an understanding of how larger arctic watersheds are responding to climate change. The North Klondike River, located in west central Yukon, is a sub-alpine permafrost catchment, which maintains an active hydrological monitoring station with a record of >40 years. In addition to being able to monitor intra-annual variability, this data set allows for more complex analysis of streamflow records. Streamflow data, geochemistry and stable isotope data for 2014 show a groundwater-dominated system, predominantly recharged during periods of snowmelt. Radiocarbon is shown to be a valuable tracer of soil zone recharge processes and carbon sources. Winter groundwater baseflow contributes 20 % of total annual discharge, and accounts for up to 50 % of total river discharge during the spring and summer months. Although total stream discharge remains unchanged, mean annual groundwater baseflow has increased over the 40-year monitoring period. Wavelet analysis reveals a catchment that responds to El Niño and longer solar cycles, as well as climatic shifts such as the Pacific Decadal Oscillation. Dedicated to Professor Peter Fritz on the occasion of his 80th birthday.

  3. Assessing Silicate Weathering in Permafrost-Dominated Catchments Using Lithium Isotopes: The Lena River, Siberia

    Science.gov (United States)

    Murphy, M. J.; Pogge von Strandmann, P.; Porcelli, D.; Katchinoff, J. A.; Moreras Martí, A.; Hirst, C. A.; Andersson, P. S.; Maximov, T. C.

    2015-12-01

    Rising global temperatures have the potential to influence the Earth's climate feedback cycles due to permafrost thawing, altering the freshwater input and trace metal and carbon fluxes into the ocean and atmosphere. Riverine lithium isotope ratios (d7Li) are a tracer of silicate weathering processes, which are key in the removal of atmospheric CO2 over geological timescales. Despite this, little is known about the effects of permafrost thawing on d7Li variations. Strong seasonal changes in the thawed active layer thickness dictate surficial water flow paths, which may influence intra-annual riverine d7Li signatures. We present a study of the dissolved d7Li from the large permafrost-dominated watersheds of the Lena River (Siberia), which drain into the Arctic Ocean. This work comprises a temporal study during the May 2015 spring flood, from ice breakup through peak flooding, thus monitoring changes in water-rock and water-soil interaction, both processes that control weathering and hence Li isotopes. Before riverine ice started to break up, high [Li] are observed as the river signature is governed by winter base flow conditions. As the river ice breaks up, surface runoff flows over the impermeable permafrost, interacting with leaf litter, diluting the [Li]. We compare d7Li over the spring flood period with a greater spatial study conducted over two summer field seasons (2012/2013) of the main Lena River channel and its tributaries, which drain a variety of lithologies/topographies. During the summer, the thawed active layer promotes deeper water flow paths, greater water-rock interaction and enhanced secondary minerals formation which preferentially take up 6Li. Summer riverine d7Li typically fall between +14.5 ‰ to +28.5 ‰, with rivers draining the Central Siberian Plateau typically exhibiting high [Li], but similar δ7Li to rivers draining the Verkhoyansk Mountain Range. Overall, this study demonstrates how Li isotopes respond to weathering in a permafrost

  4. Calculation of permissible load capacity and establishment of total amount control in the Wujin River Catchment--a tributary of Taihu Lake, China.

    Science.gov (United States)

    Zhang, Ruibin; Gao, Hailong; Zhu, Wenting; Hu, Wei; Ye, Rui

    2015-08-01

    The deterioration of water quality in Taihu Lake, China, has caused widespread concern in recent years. The primary pollution sources of Taihu Lake are its inflow rivers. Effective environmental water management strategies need to be implemented in these rivers to improve the water quality of Taihu Lake and to promote sustainable development in the region. In this study, the QUAL2K model is used in conjunction with the trial and error approach to assess permissible load capacities for the Wujin River (a major tributary of Taihu Lake) in terms of COD, NH3-N, TN, and TP. Results show that permissible annual loads for these pollutants are 5216.31, 491.71, 948.53, and 104.38 t, respectively. This suggests that COD, NH3-N, TN, and TP loads in the Wujin River catchment need to be reduced by 13.35, 27.26, 47.75, and 37.08 %, respectively, to satisfy national water quality objectives. Total amount control measures are proposed to control and reduce pollution loads of the Wujin River catchment. The method applied in this study should provide a sound basis for water environmental management decision-making.

  5. Erosion patterns in the Changjiang (Yangtze River) catchment revealed by bulk-sample versus single-mineral provenance budgets

    Science.gov (United States)

    Vezzoli, Giovanni; Garzanti, Eduardo; Limonta, Mara; Andò, Sergio; Yang, Shouye

    2016-05-01

    The Changjiang, the fourth longest river on Earth and the largest in Eurasia, has a complex sediment-routing system presently interrupted by the Three Gorges Dam, the world's largest hydroelectric engineering project. To study sediment-generation processes in the huge catchment and compare the different erosion patterns obtained by different methodological approaches, high-resolution petrographic and heavy-mineral analyses were performed on sands from the trunk river and its major tributaries. The frequency distributions of diverse groups of detrital amphiboles were also investigated. Rigorous statistical methods were used to define end-members, evaluate mineralogical variability, assess similarities among samples, and eventually calculate the relative contributions from each major tributary to the trunk river by forward end-member modelling of integrated compositional data. The litho-quartzose sand with few heavy minerals generated in Tibetan headwaters evolves downstream to feldspatho-litho-quartzose with medium-rank metamorphic rock fragments and moderately rich amphibole-epidote suites. Sand across the Sichuan basin and as far as the Three Gorges Dam is enriched in mafic volcanic, clinopyroxene, and carbonate grains eroded from Permian basalts and Paleozoic strata of the South China Block. The final (Yangtze) tract is characterized by litho-feldspatho-quartzose sand with moderately poor, amphibole-dominated suites with epidote, clinopyroxene, and garnet. The orogenic compositional signature acquired in the upper part of the basin is thus carried all the way to the Chinese passive margin, as observed also for the Yellow River in the north. Even after long-distance transport across wide continental areas, detrital modes thus reveal the tectonic character of the source rather than the geodynamic environment of the sink. Quantitative provenance analysis indicates that left-bank tributaries draining the Longmen and Qinlin mountains supply most of the sand reaching

  6. Field investigation to assess nutrient emission from paddy field to surface water in river catchment

    Science.gov (United States)

    Kogure, Kanami; Aichi, Masaatsu; Zessner, Matthias

    2015-04-01

    In order to maintain good river environment, it is remarkably important to understand and to control nutrient behavior such as Nitrogen and Phosphorus. Our former research dealing with nutrient emission analysis in the Tone River basin area in Japan, in addition to urban and industrial waste water, nutrient emission from agricultural activity is dominant pollution source into the river system. Japanese style agriculture produces large amount of rice and paddy field occupies large areas in Japanese river basin areas. While paddy field can deteriorate river water quality by outflow of fertilizer, it is also suggested that paddy field has water purification function. As we carried out investigation in the Tone River Basin area, data were obtained which dissolved nitrogen concentration is lower in discharging water from paddy field than inflowing water into the field. Regarding to nutrient emission impact from paddy field, sufficient data are required to discuss quantitatively seasonal change of material behavior including flooding season and dry season, difference of climate condition, soil type, and rice species, to evaluate year round comprehensive impact from paddy field to the river system. In this research, field survey in paddy field and data collection relating rice production were carried out as a preliminary investigation to assess how Japanese style paddy field contributes year round on surface water quality. Study sites are three paddy fields located in upper reach of the Tone River basin area. The fields are flooded from June to September. In 2014, field investigations were carried out three times in flooding period and twice in dry period. To understand characteristics of each paddy field and seasonal tendency accompanying weather of agricultural event, short term investigations were conducted and we prepare for further long term investigation. Each study site has irrigation water inflow and outflow. Two sites have tile drainage system under the field and

  7. Neural Network Model for Prediction of Discharged from the Catchments of Langat River, Malaysia

    Directory of Open Access Journals (Sweden)

    Z. Ahmad

    2010-09-01

    Full Text Available Artificial neural networks have been shown to be able to approximate any continuous non-linear functions and have been used to build data base empirical models for non-linear processes. In this study, neural networks models were used to model the daily river flows or discharged in Langat River, Malaysia. Two possible ways of modelling were implemented which is by time series prediction and by the dynamics function of the system which include the past value of the discharged and also the rainfall in the input. The sum square error (SSE, residue analysis and correlation coefficient based on the observed and prediction output is chosen as the criteria of selection of which models is appropriate. It was found that the developed neural networks models using dynamics function provided satisfactory model discharges.

  8. Restoration of the Hydrosedimentary and Ecological Continuity: Hydromorphological Impacts on the Yerres River, Seine Catchment, France

    Science.gov (United States)

    Melun, Gabriel; Arnaud-Fassetta, Gilles; Fort, Monique; Chalaux, Eric; Lucas, Emmanuelle; Fourel, Sabine; Guesdon, Loïc

    2014-05-01

    The European Water Framework Directive (WFD) aims to achieve "a good ecological and chemical status" by 2015. Hydromorphology influences ecological status in three ways: (i) hydrological regime (flow and groundwater), (ii) morphological conditions, and (iii) longitudinal and transverse continuity of rivers. Physical and ecological impacts of those structures upon hydrosystems are known, but removal's impacts are misunderstood due to lack of scientific feedbacks. According to particular methodology (following hydromorphological protocols established by ONEMA - the French National Agency for Water and Aquatic Environments), which is based on field measurements and modelling, we aim at characterizing and quantifying hydromorphological impacts of dam removals on riverbed and bank structures. This study is applied to the Yerres watershed particularly significant due to its anthropic pressure conditions. We study limnimetric adjustments, stream power variations, transport capacity variations and riverbanks dynamics in no-dam context, at the reach scale. Our results show that there is a clear morphological adjustment of the riverbed and bank structures, even though locally those possibilities are constrained by anthropogenic facilities. Run-of-the-river dam removals result in: (i) systematic lowering of water level, (ii) shrinkage of the cross-section, (iii) increase of stream-power and transport capacity, proportional to uncompartmentalised context (calculated values can be greater than 35 W/m², hence suggesting that flow would have theoretical capacity to modify the channel geometry notably in sections without protection); (iv) clear recovery of bank erosion processes during flood events. Finally, our study demonstrates that the Yerres River can be hydromorphologically restored; yet higher hydrodynamic conditions in no-dam context involve new issues particularly in relation with the human occupation of the Yerres's valley (wetlands and channels disconnection

  9. DIN retention-transport through four hydrologically connected zones in a headwater catchment of the Upper Mississippi River

    Science.gov (United States)

    Triska, F.J.; Duff, J.H.; Sheibley, R.W.; Jackman, A.P.; Avanzino, R.J.

    2007-01-01

    Dissolved inorganic nitrogen (DIN) retention-transport through a headwater catchment was synthesized from studies encompassing four distinct hydrologic zones of the Shingobee River Headwaters near the origin of the Mississippi River. The hydrologic zones included: (1) hillslope ground water (ridge to bankside riparian); (2) alluvial riparian ground water; (3) ground water discharged through subchannel sediments (hyporheic zone); and (4) channel surface water. During subsurface hillslope transport through Zone 1, DIN, primarily nitrate, decreased from ???3 mg-N/l to <0.1 mg-N/l. Ambient seasonal nitrate:chloride ratios in hillslope flow paths indicated both dilution and biotic processing caused nitrate loss. Biologically available organic carbon controlled biotic nitrate retention during hillslope transport. In the alluvial riparian zone (Zone 2) biologically available organic carbon controlled nitrate depletion although processing of both ambient and amended nitrate was faster during the summer than winter. In the hyporheic zone (Zone 3) and stream surface water (Zone 4) DIN retention was primarily controlled by temperature. Perfusion core studies using hyporheic sediment indicated sufficient organic carbon in bed sediments to retain ground water DIN via coupled nitrification-denitrification. Numerical simulations of seasonal hyporheic sediment nitrification-denitrification rates from perfusion cores adequately predicted surface water ammonium but not nitrate when compared to 5 years of monthly field data (1989-93). Mass balance studies in stream surface water indicated proportionally higher summer than winter N retention. Watershed DIN retention was effective during summer under the current land use of intermittently grazed pasture. However, more intensive land use such as row crop agriculture would decrease nitrate retention efficiency and increase loads to surface water. Understanding DIN retention capacity throughout the system, including special channel

  10. The role of catchment vegetation in reducing atmospheric inputs of pollutant aerosols in Ganga river.

    Science.gov (United States)

    Shubhashish, Kumar; Pandey, Richa; Pandey, Jitendra

    2012-08-01

    The role of woody perennials in the Ganga river basin in modifying the run-off quality as influenced by atmospheric deposition of pollutant aerosols was investigated. The concentration of seven nutrients and eight metals were measured in atmospheric deposits as well as in run-off water under the influence of five woody perennials. Nutrient retention was recorded maximum for Bougainvillea spectabilis ranged from 4.30 % to 33.70 %. Metal retention was recorded highest for Ficus benghalensis ranged from 5.15 % to 36.98 %. Although some species showed nutrient enrichment, all the species considered in the study invariably contribute to reduce nutrients and metal concentration in run-off water. Reduction in run off was recorded maximum for B. spectabilis (nutrient 6.48 %-40.66 %; metal 7.86 %-22.85 %) and minimum for Ficus religiosa (nutrient 1.68 %-27.19 %; metal 6.55 %-31.55 %). The study forms the first report on the use of woody perennials in reducing input of atmospheric pollutants to Ganga river and has relevance in formulating strategies for river basin management.

  11. Dissolved radon and uranium in groundwater in a potential coal seam gas development region (Richmond River Catchment, Australia).

    Science.gov (United States)

    Atkins, Marnie L; Santos, Isaac R; Perkins, Anita; Maher, Damien T

    2016-04-01

    The extraction of unconventional gas resources such as shale and coal seam gas (CSG) is rapidly expanding globally and often prevents the opportunity for comprehensive baseline groundwater investigations prior to drilling. Unconventional gas extraction often targets geological layers with high naturally occurring radioactive materials (NORM) and extraction practices may possibly mobilise radionuclides into regional and local drinking water resources. Here, we establish baseline groundwater radon and uranium levels in shallow aquifers overlying a potential CSG target formation in the Richmond River Catchment, Australia. A total of 91 groundwater samples from six different geological units showed highly variable radon activities (0.14-20.33 Bq/L) and uranium levels (0.001-2.77 μg/L) which were well below the Australian Drinking Water Guideline values (radon; 100 Bq/L and uranium; 17 μg/L). Therefore, from a radon and uranium perspective, the regional groundwater does not pose health risks to consumers. Uranium could not explain the distribution of radon in groundwater. Relatively high radon activities (7.88 ± 0.83 Bq/L) in the fractured Lismore Basalt aquifer coincided with very low uranium concentrations (0.04 ± 0.02 μg/L). In the Quaternary Sediments aquifers, a positive correlation between U and HCO3(-) (r(2) = 0.49, p groundwater investigations.

  12. [Spatial distribution of soil moisture and salinity and their influence factors in the farmland of Manas River catchment, Northwest China].

    Science.gov (United States)

    Shen, Hao; Abuduwaili, Jilili

    2015-03-01

    Applying methods of statistics and geo-statistics, Manas River catchment was selected as the research area to study the spatial distribution of soil moisture and salinity in the soil profile as. well as their influence factors. The coupling relationship between soil moisture and salinity presented in the spatial distribution was explored as well. The result showed that the soil moisture was overall at a low level (varying from 14.2% to 20.9%), while the salinity was relatively high (about 6.00-9.15 g . kg-1). The soil profile distribution of water and salt contents both showed a trend of bottom accumulation. The variation of soil water moisture was moderate, while that of salt content was strong. Soil salinity and moisture of all layers showed strong spatial autocorrelation, which were mainly affected by structural factors. The horizontal distribution patterns of water and salt contents were irregular, and were constrained by factors like terrain and landforms, etc. Disturbed by human activities, the coupling relation of soil moisture and salinity became much more complex, but their spatial distribution variation was synchronized to some extent.

  13. Effects of catchment and riparian landscape setting on water chemistry and seasonal evolution of water quality in the upper Han River basin, China.

    Directory of Open Access Journals (Sweden)

    Siyue Li

    Full Text Available Six-year (2005-2010 evolution of water chemistry (Cl(-, NO(3(-, SO(4(2-, HCO(3(-, Na(+, K(+, Ca(2+ and Mg(2+ and their interactions with morphological properties (i.e., slope and area, land cover, and hydrological seasonality were examined to identify controlling factors and processes governing patterns of stream water quality in the upper Han River, China. Correlation analysis and stepwise multiple regression models revealed significant correlations between ions (i.e., Cl(-, SO(4(2-, Na(+ and K(+ and land cover (i.e., vegetation and bare land over the entire catchment in both high- and low-flow periods, and in the buffer zone the correlation was much more stronger in the low-flow period. Catchment with steeper slope (>15° was negatively correlated with major ions, largely due to multicollinearity of basin characteristics. Land cover within the buffer zone explained slightly less of major elements than at catchment scale in the rainy season, whereas in the dry season, land cover along the river networks in particular this within 100 m riparian zone much better explained major elements rather than this over the entire catchment. Anthropogenic land uses (i.e., urban and agriculture however could not explain water chemical variables, albeit EC, TDS, anthropogenic markers (Cl(-, NO(3(-, SO(4(2, Na(+, K(+ and Ca(2+ significantly increased during 2005-2010, which was corroborated by principal component analyses (PCA that indicated anthropogenic inputs. Observations demonstrated much higher solute concentrations in the industrial-polluted river. Our results suggested that seasonal evolution of water quality in combined with spatial analysis at multiple scales should be a vital part of identifying the controls on spatio-temporal patterns of water quality.

  14. WATER QUALITY ANALYSIS OF LOTIC ECOSYSTEMS FROM UPPER MUREŞ RIVER CATCHMENT AREA USING DIFFERENT BIOTIC INDICES

    Directory of Open Access Journals (Sweden)

    Milca PETROVICI

    2012-01-01

    Full Text Available Present paper approach the issue of assessing the water quality of tributaries located in the upper basin of the river Mureş, taking into account changes in the value of biotic indices. In this sense, have been selected the next five biotic indices: Ephemeroptera Plecoptera Trichoptera index (EPT, Total Invertebrates index (T, Chironomidae index (Ch, EPT / Total invertebrates index (EPT / T, EPT / Chironomidae index (EPT / Ch and % Chironomidae index (% Chironomidae. Considering all these indices, it was found existence of a medium to best quality water in Mureş tributaries from Harghita Mountains and a good quality water which comes from the Maramureş Mountains and Transylvania Plateau.

  15. Modelling the impact of prescribed global warming on water resources of headwater catchments of the Irrawaddy River and their implications for Loktak Lake, northeast India

    Directory of Open Access Journals (Sweden)

    C. R. Singh

    2010-05-01

    Full Text Available Climate change is likely to have major implications for wetland ecosystems, which will include altered water level regimes due to modifications in local and catchment hydrology. However, substantial uncertainty exists in the precise impacts of climate change on wetlands due in part due to uncertainty in GCM projections. This paper explores the impacts of climate change upon river discharge within three sub-catchments of Loktak Lake, an internationally important wetland in northeast India. This is achieved by running pattern-scaled GCM output through distributed hydrological models (developed using MIKE SHE of each sub-catchment. The impacts of climate change upon water levels within Loktak Lake are subsequently investigated using a water balance model. Two groups of climate change scenarios are investigated. Group 1 uses results from seven different GCMs for an increase in global mean temperature of 2 °C, the purported threshold of "dangerous" climate change, whilst Group 2 is based on results from the HadCM3 GCM for increases in global mean temperature between 1 °C and 6 °C. Results from the Group 1 scenarios show varying responses between the three sub-catchments. The majority of scenario-sub-catchment combinations (13 out of 21 indicate increases in discharge which vary from <1% to 42% although, in some cases, discharge decreases by as much as 20%. Six of the GCMs suggest overall increases in river flow to Loktak Lake (2–27% whilst the other results in a modest (6% decline. In contrast, the Group 2 scenarios lead to an almost linear increase in total river flow to Loktak Lake with increasing temperature (up to 27% for 6 °C, although two sub-catchments experience reductions in mean discharge for the smallest temperature increases. In all but one Group 1 scenario, and all the Group 2 scenarios, Loktak Lake water levels are higher, regularly reaching the top of a downstream hydropower barrage that impounds the lake and necessitating the

  16. TransWatL - Crowdsourced water level transmission via short message service within the Sondu River Catchment, Kenya

    Science.gov (United States)

    Weeser, Björn; Jacobs, Suzanne; Breuer, Lutz; Butterbach-Bahl, Klaus; Rufino, Mariana

    2016-04-01

    The fast economic development in East African countries causes an increasing need of water and farmland. Ongoing changes in land use and climate may affect the function of water tower areas such as the Mau Forest complex as an important water source and tropical montane forest in Kenya. Reliable models and predictions are necessary to ensure a sustainable and adequate water resource management. The calibration and validation process of these models requires solid data, based on widespread monitoring in both space and time, which is a time consuming and expensive exercise. Countries with merging economies often do not have the technical capacity and resources to operate monitoring networks, although both the government and citizens are aware of the importance of sustainable water management. Our research focus on the implementation and testing of a crowdsourced database as a low-cost method to assess the water quantity within the Sondu river catchment in Kenya. Twenty to 30 water level gauges will be installed and equipped with instructional signage. Citizens are invited to read and transmit the water level and the station number to the database using a simple text message and their cell phone. The text message service is easy to use, stable, inexpensive and an established way of communication in East African countries. The simplicity of the method ensures a broad access for interested citizens and integration of locals in water monitoring all over the catchment. Furthermore, the system allows a direct and fast feedback to the users, which likely increases the awareness for water flow changes in the test region. A raspberry pi 2 Model B equipped with a mobile broadband modem will be used as a server receiving and storing incoming text messages. The received raw data will be quality checked and formatted by a python script and afterwards written back in a database. This ensures flexible and standardized access for postprocessing and data visualization, for which a

  17. Flood-initiating catchment conditions: a spatio-temporal analysis of large-scale soil moisture patterns in the Elbe River basin

    Directory of Open Access Journals (Sweden)

    M. Nied

    2013-04-01

    Full Text Available Floods are the result of a complex interaction between meteorological event characteristics and pre-event catchment conditions. While the large-scale meteorological conditions have been classified and successfully linked to floods, this is lacking for the large-scale pre-event catchment conditions. Therefore, we propose classifying soil moisture as a key variable of pre-event catchment conditions and investigating the link between soil moisture patterns and flood occurrence in the Elbe River basin. Soil moisture is simulated using a semi-distributed conceptual rainfall-runoff model over the period 1951–2003. Principal component analysis (PCA and cluster analysis are applied successively to identify days of similar soil moisture patterns. The results show that PCA considerably reduced the dimensionality of the soil moisture data. The first principal component (PC explains 75.71% of the soil moisture variability and represents the large-scale seasonal wetting and drying. The successive PCs express spatially heterogeneous catchment processes. By clustering the leading PCs, we identify large-scale soil moisture patterns which frequently occur before the onset of floods. In winter, floods are initiated by overall high soil moisture content, whereas in summer the flood-initiating soil moisture patterns are diverse and less stable in time.

  18. Environmental land use conflicts in catchments: A major cause of amplified nitrate in river water.

    Science.gov (United States)

    Pacheco, F A L; Sanches Fernandes, L F

    2016-04-01

    Environmental land use conflicts are uses of the land that ignore soil capability. In this study, environmental land use conflicts were investigated in mainland Portugal, using Partial Least Squares (PLS) regression combined with GIS modeling and a group of 85 agricultural watersheds (with >50% occupation by agriculture) as work sample. The results indicate a dominance of conflicts in a region where vineyards systematically invaded steep hillsides (the River Douro basin), where forests would be the most appropriate use. As a consequence of the conflicts, nitrate concentrations in rivers and lakes from these areas have increased, sometimes beyond the legal limit of 50mg/L imposed by the European and Portuguese laws. Excessive nitrate concentrations were also observed along the Atlantic coast of continental Portugal, but associated to a combination of other factors: large population densities, and incomplete coverage by sewage systems and inadequate functioning of wastewater treatment plants. Before this study, environmental land use conflicts were never recognized as possible boost of nitrate concentrations in surface water. Bearing in mind the consequences of drinking water nitrate for human health, a number of land use change scenarios were investigated to forecast their impact on freshwater nitrate concentrations. It was seen that an aggravation of the conflicts would duplicate the number of watersheds with maximum nitrate concentrations above 50mg/L (from 11 to 20 watersheds), while the elimination of the conflicts would greatly reduce that number (to 3 watersheds).

  19. Heavy metal enrichments in the Changjiang (Yangtze River) catchment and on the inner shelf of the East China Sea over the last 150 years.

    Science.gov (United States)

    Guo, Yanwei; Yang, Shouye

    2016-02-01

    Compositions of heavy metals including Cu, Zn, Cr and Pb in three sediment cores recovered from the lower basin of the Changjiang (Yangtze River) and the inner shelf mud of the East China Sea were analyzed by traditional X-ray florescence (XRF) and XRF Core Scanner. This study aims to investigate the accumulation of heavy metals in the fluvial sediments and to decipher the influence of anthropogenic activities within the large catchment over the last 150 years. The data suggest that the heavy metals, especially Pb and Zn, show obvious enrichments in concentrations since 1950s, and the small and consistent variations of heavy metal concentrations before 1950s can represent geochemical background values. After removing the grain size effect on elemental concentrations, we infer that the sources of heavy metals predominantly come from natural weathering detritus, while human contamination has increased over the last half century. The calculations of both enrichment factor and geoaccumulation index, however, indicate that the pollution of these heavy metals in the fluvial and shelf environments is not significant. The rapid increase in human activities and fast socioeconomic development in the Changjiang catchment and East China over the last five decades accounts for the enrichments of heavy metals in the river and marine sediments. The inner shelf of the East China Sea, as the major sink of the Changjiang-derived fine sediments, provides a high-resolution sediment archive for tracing the anthropogenic impacts on the catchment.

  20. Status of riverine soils of a Mediterranean river catchment (the Turia river, Spain) regarding potential contamination of heavy metals and pesticides

    Science.gov (United States)

    Andreu, Vicente; Gimeno-García, Eugenia; Pascual, Juan Antonio; Picó, Yolanda

    2016-04-01

    Rivers are sink structures receiving diffuse contamination mainly from agricultural practices. Hydrological dynamics of these watercourses favour, by one hand, the transport of contaminants (dissolved, complexed or adsorbed to suspended particles) and, by the other, their accumulation in sediments. These circumstances affect at different scales the quality of soils, waters, and the entire riverine ecosystems. In this work, 7 heavy metals and 50 pesticides were monitored in riverine soils of the Turia River catchment. From the source to the mounth, along the entiere river, 22 sampling points were selected for sampling according different lithologies, land uses, population size and the proximity to waste waters treatment plants (WWTPs). Cd, Co, Cr, Cu, Pb, Ni and Zn were analysed to determine its total and extractable contents in soils. Total content of metals was established by microwave acid digestion and the extractable fraction in soils and sediments by treatment with EDTA. Atomic Absorption Spectrometry, using graphite furnace when necessary, was used for the determination of the selected metals. Pesticide residues were extracted from the soil samples using the QuEchERS method and determined by Liquid Chromatograph-tandem Mass Spectrometry (LC-MS/MS). Recoveries ranged from 40 to 105 %. The limits of quantification ranged from 0.1 to 5.0 ng g-1. The higest levels of total and extractable Cd, Co, Cr and Ni were determined near the Benageber reservoir, located in the middle course of the river, where an important forest fires occurred a year ago. High levels of metals, mainly Cr and Zn, appeared headwaters in the Alfambra tributary. This deserves special mention because it was selected as a little impacted area that could serve as non-contaminated reference for the river. From the 50 pesticides condsidered, 26 were detected, with the highest levels for acetochlor (290.00 ng g-1) and a degradation product of terbutyazine - terbuthylazine deethyl - (234.75 ng g-1

  1. Rainfall-runoff modelling of the Okavango River catchment to assess impacts of land use change on runoff and downstream ecosystems

    Science.gov (United States)

    Milzow, Christian; Bauer-Gottwein, Peter

    2010-05-01

    The competition between human water use and ecosystem water use is one of the major challenges for water resources management at the global scale. We analyse the situation for the Okavango River basin of southern Africa. The Okavango River is representative for many large rivers throughout the developing world in that it is ungauged and poorly studied. The Okavango basin - spanning over Angola, Namibia and Botswana - represents a multi-objective problem in an international setting. Economic benefits of agricultural development and conservation of ecosystem services call for opposed actions. A semi-distributed rainfall-runoff model of the Okavango catchment is set up using the Soil and Water Assessment Tool (SWAT). The model is sufficiently physically based to simulate the impact on runoff of extent of agricultural use, crop types and management practices. Precipitation and temperature inputs are taken from datasets covering large parts of the globe. The methodology can thus easily be applied for other ungauged catchments. For temperature we use the ERA-Interim reanalysis product of the European Centre for Medium-Range Weather Forecasts and for precipitation the Famine Early Warning Systems Network data (FEWS-Net). Tropical Rainfall Measurement Mission (TRMM) data resulted in poor model performance compared to the FEWS-Net data. Presently, the upstream catchment in Angola is largely pristine and agriculture is basically restricted to dry land subsistence farming. But economic growth in Angola is likely to result in agricultural development and consequent impacts on catchment runoff. Land use scenarios that are simulated include large scale irrigated agriculture with water extractions from the river and the shallow aquifer. Climate change impacts are also studied and compared to land use change impacts. The downstream part of the basin consists of the large Okavango Wetlands, which are a biodiversity hotspot of global importance and, through tourism, an important

  2. Flood-event based metal distribution patterns in water as approach for source apportionment of pollution on catchment scale: Examples from the River Elbe

    Science.gov (United States)

    Baborowski, Martina; Einax, Jürgen W.

    2016-04-01

    With the implementation of European Water Frame Work Directive (EU-WFD), the pollution sources in the River Elbe were assessed by the River Basin Community Elbe (RBC Elbe). Contaminated old sediments played the most significant role for inorganic and organic pollution. In terms of further improvement of the water quality in the river system, a prioritization of the known pollution sources is necessary, with respect to the expected effect in the case of their remediation. This requires information on mobility of contaminated sediments. To create a tool that allows the assessment of pollution trends in the catchment area, event based flood investigations were carried out at a sampling site in the Middle Elbe. The investigations were based on a comparable, discharge related sampling strategy. Four campaigns were performed between 1995 and 2006. The majority of the investigated 16 elements (>80%) studied more intensively in 2006 reached its maximum concentration during the first five days of the event. Only the concentrations of B, Cl-, and U declined with increasing discharge during the flood. The aim of the study was to verify that each flood event is characterized by an internal structure of the water quality. This structure is formed by the appearance of maximum values of water quality parameters at different times during the event. It could be detected by descriptive and multivariate statistical methods. As a result, internal structure of the water quality during the flood was influenced primarily by the source of the metals in the catchment area and its distance from the sampling point. The transport of metals in dissolved, colloidal or particulate form and changes of their ratios during the flood were however, not decisive for the formation of the structure. Our results show that the comparison of the structures obtained from events in different years is indicative of the pollution trend in the catchment area. Exemplarily the trend of the metal pollution in the

  3. Questa baseline and pre-mining ground-water quality investigation. 14. Interpretation of ground-water geochemistry in catchments other than the Straight Creek catchment, Red River Valley, Taos County, New Mexico, 2002-2003

    Science.gov (United States)

    Nordstrom, D. Kirk; McCleskey, R. Blaine; Hunt, Andrew G.; Naus, Cheryl A.

    2005-01-01

    The U.S. Geological Survey, in cooperation with the New Mexico Environment Department, is investigating the pre-mining ground-water chemistry at the Molycorp molybdenum mine in the Red River Valley, New Mexico. The primary approach is to determine the processes controlling ground-water chemistry at an unmined, off-site but proximal analog. The Straight Creek catchment, chosen for this purpose, consists of the same Tertiary-age quartz-sericite-pyrite altered andesite and rhyolitic volcanics as the mine site. Straight Creek is about 5 kilometers east of the eastern boundary of the mine site. Both Straight Creek and the mine site are at approximately the same altitude, face south, and have the same climatic conditions. Thirteen wells in the proximal analog drainage catchment were sampled for ground-water chemistry. Eleven wells were installed for this study and two existing wells at the Advanced Waste-Water Treatment (AWWT) facility were included in this study. Eight wells were sampled outside the Straight Creek catchment: one each in the Hansen, Hottentot, and La Bobita debris fans, four in a well cluster in upper Capulin Canyon (three in alluvial deposits and one in bedrock), and an existing well at the U.S. Forest Service Questa Ranger Station in Red River alluvial deposits. Two surface waters from the Hansen Creek catchment and two from the Hottentot drainage catchment also were sampled for comparison to ground-water compositions. In this report, these samples are evaluated to determine if the geochemical interpretations from the Straight Creek ground-water geochemistry could be extended to other ground waters in the Red River Valley , including the mine site. Total-recoverable major cations and trace metals and dissolved major cations, selected trace metals, anions, alkalinity; and iron-redox species were determined for all surface- and ground-water samples. Rare-earth elements and low-level As, Bi, Mo, Rb, Re, Sb, Se, Te, Th, U, Tl, V, W, Y, and Zr were

  4. Fragmentation and connection of frames in collaborative water governance: a case study of river catchment management in Southern Ecuador

    NARCIS (Netherlands)

    Dewulf, A.; Mancero, M.; Cárdenas, G.; Sucozhañay, D.

    2011-01-01

    In collaborative water governance, the variety of frames that actors bring to the discussion constitutes an important challenge. In this study, we analyse the fragmentation and connection of frames in collaborative water governance projects in the Paute catchment and its sub-catchment Tabacay in the

  5. Assessing the past impact of climatic variability and human activities on the water resources of the Hérault River catchment (South of France)

    Science.gov (United States)

    Collet, L.; Ruelland, D.; Borrell-Estupina, V.; Servat, E.

    2012-04-01

    This study investigates the hydrological functioning scheme of a Mediterranean catchment. Located in southern France, the mesoscale Hérault River catchment (~2500 km2) supplies with water its inhabitants and some external cities as well as agricultural activities. The catchment water resources are intensively exploited during summertime, when tourism and irrigation needs reach a peak while water supply is limited. Since the 1980s, discharge has significantly decreased in various gauging stations. The functioning scheme aims at understanding the impact of climatic variability and human activities on the water resources of this catchment over the last 50 years. Firstly, a quality analysis of the hydro-climatic and anthropogenic variables was conducted. This allowed a robust database to be constituted over the 1959-2010 period. The hydro-climatic trends over the catchment were then studied from analysis of statistical breaks in the series of precipitation, temperature, discharge and water withdrawals. A correlation analysis was also performed to assess the influence of each forcing variable on water flow at the outlet. In order to investigate the catchment heterogeneity, six sub-basins have been identified according to the main geographical characteristics (climate, topography, lithology, land use, water uses…) and to the availability of the streamflow series. Finally, a detailed water balance at different scales made it possible to estimate the respective impact of changes in climate, land use and water withdrawals on the water resources within the basin. The statistical analysis demonstrated a break in the temperature and discharge series around 1980, but no break was detected for precipitations. Temperatures have increased by 1°C on average between 1959-1979 and 1980-2010 while discharge has decreased by 33-40% in the same time at different gauging stations. Meanwhile, the catchment has undergone a sensible reforestation since forested areas have increased from

  6. Urban and agricultural contribution of annual loads of glyphosate and AMPA towards surface waters at the Orge River catchment scale (France)

    Science.gov (United States)

    Botta, Fabrizio; Chevreuil, Marc; Blanchoud, Hélène

    2010-05-01

    The general use of pesticides in the Orge Basin, located in the southern part of the Paris suburb (France), is damaging surface water quality. Consequently, an increase in the water supply costs is registered by the water supply agencies that are situated downstream the Orge confluence with the Seine River. In this catchment, high uses of glyphosate are registered for fallow fields (upstream part) and for roadway weed control (downstream part). The proportion of glyphosate coming from these two zones was not well known, along with the double source of its metabolite AMPA originated from the degradation of some detergent phosphonates. The aim of this work was firstly to identify the potential sources of glyphosate and AMPA in urban sectors (such as sewerage system inputs) and in agricultural areas and to quantify the origins of urban pesticides pathways towards surface waters at the basin scale. The new approach of this project was to collect information at three different scales to establish a first step of modeling. At the basin scale, 1 year of surface water monitoring at the outlet of the Orge River was useful to establish the inputs towards the Seine River. At the urban catchment scale, the investigations have permitted to record glyphosate and AMPA loads transferred by storm waters and by wastewaters. Loads were estimated during and out of application calendar, in different hydrological conditions such as rainfall with high intensity or dry conditions. Impact of WWTP on surface water was also demonstrated. The third phase of this work was the interpretation of agricultural inputs from two different agricultural catchments of the Orge River. The results showed the impact of urban uses of glyphosate upon the Orge River contamination with annual loads from 100 times higher from the urban zone than from the agricultural one. Storm sewers were recognized to be the main way for glyphosate transfer towards surface waters. A budget of glyphosate and AMPA inputs and

  7. Modelling the impact of prescribed global warming on water resources of headwater catchments of the Irrawaddy River and their implications for Loktak Lake, northeast India

    Science.gov (United States)

    Singh, C. R.; Thompson, J. R.; French, J. R.; Kingston, D. G.; Mackay, A. W.

    2010-05-01

    Climate change is likely to have major implications for wetland ecosystems, which will include altered water level regimes due to modifications in local and catchment hydrology. However, substantial uncertainty exists in the precise impacts of climate change on wetlands due in part due to uncertainty in GCM projections. This paper explores the impacts of climate change upon river discharge within three sub-catchments of Loktak Lake, an internationally important wetland in northeast India. This is achieved by running pattern-scaled GCM output through distributed hydrological models (developed using MIKE SHE) of each sub-catchment. The impacts of climate change upon water levels within Loktak Lake are subsequently investigated using a water balance model. Two groups of climate change scenarios are investigated. Group 1 uses results from seven different GCMs for an increase in global mean temperature of 2 °C, the purported threshold of "dangerous" climate change, whilst Group 2 is based on results from the HadCM3 GCM for increases in global mean temperature between 1 °C and 6 °C. Results from the Group 1 scenarios show varying responses between the three sub-catchments. The majority of scenario-sub-catchment combinations (13 out of 21) indicate increases in discharge which vary from hydropower barrage that impounds the lake and necessitating the release of water for barrage structural stability. Although elevated water levels may permit enhanced abstraction for irrigation and domestic uses, future increases in hydropower generation are limited by existing infrastructure. The higher water levels are likely to exacerbate existing ecological deterioration within the lake as well as enhancing problems of flooding of lakeside communities.

  8. Transfer and transformation of soil iron and implications for hydrogeomorpholocial changes in Naoli River catchment, sanjiang plain, Northeast China

    Science.gov (United States)

    Ming, J.; Xianguo, L.; Hongqing, W.; Yuanchun, Z.; Haitao, W.

    2011-01-01

    Wetland soils are characterized by alternating redox process due to the fluctuation of waterlogged conditions. Iron is an important redox substance, and its transfer and transformation in the wetland ecosystem could be an effective indicator for the environment changes. In this paper, we selected the Naoli River catchment in the Sanjiang Plain, Northeast China as the study area to analyze the dynamics of transfer and transformation of soil iron, and the relationship between iron content change and environmental factors. The results show that the total and crystalline iron contents reach the peak in the depth of 60 cm in soil profile, while the amorphous iron content is higher in the topsoil. In the upper reaches, from the low to high landscape positions, the total and crystalline iron contents decrease from 62.98 g/kg to 41.61 g/kg, 22.82 g/kg to 10.53 g/kg respectively, while the amorphous iron content increases from 2.42 g/kg to 8.88 g/kg. Amorphous iron content has positive correlation with organic matter and soil water contents, while negative correlation with pH. Moreover, both the crystalline and amorphous iron contents present no correlation with total iron content, indicating that environmental factors play a more important role in the transfer and transformation of iron other than the content of the total iron. Different redoximorphic features were found along the soil profile due to the transfer and transformation of iron. E and B horizons of wetland soil in the study area have a matrix Chroma 2 or less, and all the soil types can meet the criteria of American hydric soil indicators except albic soil. ?? Science Press, Science Press, Northeast Institute of Geography and Agroecology, CAS and Springer-Verlag Berlin Heidelberg 2011.

  9. Implementation and validation of a Wilks-type multi-site daily precipitation generator over a typical Alpine river catchment

    Science.gov (United States)

    Keller, D. E.; Fischer, A. M.; Frei, C.; Liniger, M. A.; Appenzeller, C.; Knutti, R.

    2015-05-01

    Many climate impact assessments require high-resolution precipitation time series that have a spatio-temporal correlation structure consistent with observations, for simulating either current or future climate conditions. In this respect, weather generators (WGs) designed and calibrated for multiple sites are an appealing statistical downscaling technique to stochastically simulate multiple realisations of possible future time series consistent with the local precipitation characteristics and their expected future changes. In this study, we present the implementation and validation of a multi-site daily precipitation generator re-built after the methodology described in Wilks (1998). The generator consists of several Richardson-type WGs run with spatially correlated random number streams. This study aims at investigating the capabilities, the added value and the limitations of the precipitation generator for a typical Alpine river catchment in the Swiss Alpine region under current climate. The calibrated multi-site WG is skilful at individual sites in representing the annual cycle of the precipitation statistics, such as mean wet day frequency and intensity as well as monthly precipitation sums. It reproduces realistically the multi-day statistics such as the frequencies of dry and wet spell lengths and precipitation sums over consecutive wet days. Substantial added value is demonstrated in simulating daily areal precipitation sums in comparison to multiple WGs that lack the spatial dependency in the stochastic process. Limitations are seen in reproducing daily and multi-day extreme precipitation sums, observed variability from year to year and in reproducing long dry spell lengths. Given the performance of the presented generator, we conclude that it is a useful tool to generate precipitation series consistent with the mean climatic aspects and likely helpful to be used as a downscaling technique for climate change scenarios.

  10. Groundwater–surface water interactions, vegetation dependencies and implications for water resources management in the semi-arid Hailiutu River catchment, China – a synthesis

    Directory of Open Access Journals (Sweden)

    Y. Zhou

    2013-07-01

    Full Text Available During the last decades, large-scale land use changes took place in the Hailiutu River catchment, a semi-arid area in northwest China. These changes had significant impacts on the water resources in the area. Insights into groundwater and surface water interactions and vegetation-water dependencies help to understand these impacts and formulate sustainable water resources management policies. In this study, groundwater and surface water interactions were identified using the baseflow index at the catchment scale, and hydraulic and water temperature methods as well as event hydrograph separation techniques at the sub-catchment scale. The results show that almost 90% of the river discharge consists of groundwater. Vegetation dependencies on groundwater were analysed from the relationship between the Normalized Difference Vegetation Index (NDVI and groundwater depth at the catchment scale and along an ecohydrogeological cross-section, and by measuring the sap flow of different plants, soil water contents and groundwater levels at different research sites. The results show that all vegetation types, i.e. trees (willow (Salix matsudana and poplar (Populus simonii, bushes (salix – Salix psammophila, and agricultural crops (maize – Zea mays, depend largely on groundwater as the source for transpiration. The comparative analysis indicates that maize crops use the largest amount of water, followed by poplar trees, salix bushes, and willow trees. For sustainable water use with the objective of satisfying the water demand for socio-economical development and to prevent desertification and ecological impacts on streams, more water-use-efficient crops such as sorghum, barley or millet should be promoted to reduce the consumptive water use. Willow trees should be used as wind-breaks in croplands and along roads, and drought-resistant and less water-use intensive plants (for instance native bushes should be used to vegetate sand dunes.

  11. River catchment rainfall series analysis using additive Holt–Winters method

    Indian Academy of Sciences (India)

    Yan Jun Puah; Yuk Feng Huang; Kuan Chin Chua; Teang Shui Lee

    2016-03-01

    Climate change is receiving more attention from researchers as the frequency of occurrence of severe natural disasters is getting higher. Tropical countries like Malaysia have no distinct four seasons; rainfall has become the popular parameter to assess climate change. Conventional ways that determine rainfalltrends can only provide a general result in single direction for the whole study period. In this study, rainfall series were modelled using additive Holt–Winters method to examine the rainfall pattern in Langat River Basin, Malaysia. Nine homogeneous series of more than 25 years data and less than 10%missing data were selected. Goodness of fit of the forecasted models was measured. It was found that seasonal rainfall model forecasts are generally better than the monthly rainfall model forecasts. Three stations in the western region exhibited increasing trend. Rainfall in southern region showed fluctuation. Increasing trends were discovered at stations in the south-eastern region except the seasonal analysis at station 45253. Decreasing trend was found at station 2818110 in the east, while increasing trend was shown at station 44320 that represents the north-eastern region. The accuracies of both rainfall model forecasts were tested using the recorded data of years 2010–2012. Most of the forecasts are acceptable.

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

    Science.gov (United States)

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

    2013-04-01

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

  13. Insight into biogeochemical inputs and composition of Greenland Ice Sheet surface snow and glacial forefield river catchment environments.

    Science.gov (United States)

    Cameron, Karen; Hagedorn, Birgit; Dieser, Markus; Christner, Brent; Choquette, Kyla; Sletten, Ronald; Lui, Lu; Junge, Karen

    2014-05-01

    The volume of freshwater transported from Greenland to surrounding marine waters has tended to increase annually over the past four decades as a result of warmer surface air temperatures (Bamber et al 2012, Hanna et al 2008). Ice sheet run off is estimated to make up approximately of third of this volume (Bamber et al 2012). However, the biogeochemical composition and seeding sources of the Greenland Ice Sheet supraglacial landscape is largely unknown. In this study, the structure and diversity of surface snow microbial assemblages from two regions of the western Greenland Ice Sheet ice-margin was investigated through the sequencing of small subunit rRNA genes. Furthermore, the origins of microbiota were investigated by examining correlations to molecular data obtained from marine, soil, freshwater and atmospheric environments and to geochemical analytes measured in the snow. Snow was found to contain a diverse assemblage of bacteria (Alphaproteobacteria, Betaproteobacteria and Gammaproteobacteria) and eukarya (Alveolata, Fungi, Stramenopiles and Viridiplantae). Phylotypes related to archaeal Thaumarchaeota and Euryarchaeota phyla were also identified. The structure of microbial assemblages was found to have strong similarities to communities sampled from marine and air environments, and sequences obtained from the South-West region, near Kangerlussuaq, which is bordered by an extensive periglacial expanse, had additional resemblances to soil originating communities. Strong correlations were found between bacterial beta diversity and Na+ and Cl- concentrations. These data suggest that surface snow from western regions of Greenland contain microbiota that are most likely derived from exogenous, wind transported sources. Downstream of the supraglacial environment, Greenland's rivers likely influence the ecology of localized estuary and marine systems. Here we characterize the geochemical and biotic composition of a glacial and glacial forefield fed river catchment in

  14. Process-based hydrological modeling using SWAT: The effect of permafrost on water resources in the large-scale river catchment Kharaa / Mongolia

    Science.gov (United States)

    Hülsmann, L.; Geyer, T.; Karthe, D.; Priess, J.; Schweitzer, C.

    2012-04-01

    In this study, the Soil Water Assessment Tool (SWAT) was applied to obtain a better understanding of hydrological processes in the semi-arid catchment of the Kharaa River in Northern Mongolia. The transient, physical-based model SWAT was set up using spatial datasets on soil, land use, climate, and stream network provided by the project "IWRM-MoMo" to (i.) simulate the water balance components of the basin and (ii.) to identify potential gaps in the input data. We found that the SWAT model satisfactorily reflects the hydrological processes in the catchment and simulates river runoff as a response to strong rainfall events as well as to snow and ice melt. To obtain correct runoff volumes during spring, permafrost has to be considered. Permafrost-influenced soils constrain water flow in the frozen layer, so that percolation out of the active layer is hampered (Woo 2011). This effect is reproduced in SWAT by assigning an impermeable layer in the subsurface to the areas dominated by permafrost. The simulations indicate that in these regions groundwater resources are limited as a consequence of impermeable ground ice. In addition, groundwater recharge rates in the catchment are generally low due to high evaporation rates (80-90 %). Consequently the base flow contribution is small. Further studies on the estimation of groundwater recharge rates should be carried out, since groundwater is an important resource for water supply. Model results indicate that the non-uniformity of the precipitation distribution was not sufficiently covered by the interpolated input data, so that precipitation and runoff volumes are partially over- or underestimated. Since precipitation defines the overall water availability in river catchments (Baumgartner 1982), additional climate records would considerably improve model outputs. As a consequence of large evapotranspiration losses, discharge as well as groundwater recharge estimates were identified to be highly sensitive to

  15. Common problematic aspects of coupling hydrological models with groundwater flow models on the river catchment scale

    Directory of Open Access Journals (Sweden)

    R. Barthel

    2006-01-01

    Full Text Available Model coupling requires a thorough conceptualisation of the coupling strategy, including an exact definition of the individual model domains, the "transboundary" processes and the exchange parameters. It is shown here that in the case of coupling groundwater flow and hydrological models – in particular on the regional scale – it is very important to find a common definition and scale-appropriate process description of groundwater recharge and baseflow (or "groundwater runoff/discharge" in order to achieve a meaningful representation of the processes that link the unsaturated and saturated zones and the river network. As such, integration by means of coupling established disciplinary models is problematic given that in such models, processes are defined from a purpose-oriented, disciplinary perspective and are therefore not necessarily consistent with definitions of the same process in the model concepts of other disciplines. This article contains a general introduction to the requirements and challenges of model coupling in Integrated Water Resources Management including a definition of the most relevant technical terms, a short description of the commonly used approach of model coupling and finally a detailed consideration of the role of groundwater recharge and baseflow in coupling groundwater models with hydrological models. The conclusions summarize the most relevant problems rather than giving practical solutions. This paper aims to point out that working on a large scale in an integrated context requires rethinking traditional disciplinary workflows and encouraging communication between the different disciplines involved. It is worth noting that the aspects discussed here are mainly viewed from a groundwater perspective, which reflects the author's background.

  16. Common problematic aspects of coupling hydrological models with groundwater flow models on the river catchment scale

    Science.gov (United States)

    Barthel, R.

    2006-09-01

    Model coupling requires a thorough conceptualisation of the coupling strategy, including an exact definition of the individual model domains, the "transboundary" processes and the exchange parameters. It is shown here that in the case of coupling groundwater flow and hydrological models - in particular on the regional scale - it is very important to find a common definition and scale-appropriate process description of groundwater recharge and baseflow (or "groundwater runoff/discharge") in order to achieve a meaningful representation of the processes that link the unsaturated and saturated zones and the river network. As such, integration by means of coupling established disciplinary models is problematic given that in such models, processes are defined from a purpose-oriented, disciplinary perspective and are therefore not necessarily consistent with definitions of the same process in the model concepts of other disciplines. This article contains a general introduction to the requirements and challenges of model coupling in Integrated Water Resources Management including a definition of the most relevant technical terms, a short description of the commonly used approach of model coupling and finally a detailed consideration of the role of groundwater recharge and baseflow in coupling groundwater models with hydrological models. The conclusions summarize the most relevant problems rather than giving practical solutions. This paper aims to point out that working on a large scale in an integrated context requires rethinking traditional disciplinary workflows and encouraging communication between the different disciplines involved. It is worth noting that the aspects discussed here are mainly viewed from a groundwater perspective, which reflects the author's background.

  17. A laboratory based experimental study of mercury emission from contaminated soils in the River Idrijca catchment

    Directory of Open Access Journals (Sweden)

    D. Kocman

    2010-02-01

    Full Text Available Results obtained by a laboratory flux measurement system (LFMS focused on investigating the kinetics of the mercury emission flux (MEF from contaminated soils of the Idrija Hg-mine region, Slovenia are presented. Representative soil samples with respect to total Hg concentrations (4–417 μg g−1 and land cover (forest, meadow and alluvial soil alongside the River Idrijca were analysed to determine the variation in MEF versus distance from the source, regulating three major environmental parameters comprising soil temperature, soil moisture and solar radiation. MEFs ranged from less than 2 to 530 ng m−2 h−1, with the highest emissions from contaminated alluvial soils and soils near the mining district in the town of Idrija. A significant decrease of MEF was then observed with increasing distance from these sites. The results revealed a strong positive effect of all three parameters investigated on momentum MEF. The light-induced flux was shown to be independent of the soil temperature, while the soil aqueous phase seems to be responsible for recharging the pool of mercury in the soil available for both the light- and thermally-induced flux. The overall flux response to simulated environmental conditions depends greatly on the form of Hg in the soil. Higher activation energies are required for the overall process to occur in soils where insoluble cinnabar prevails compared to soils where more mobile Hg forms and forms available for transformation processes are dominant.

  18. Status of riverine soils, waters and sediments of a Mediterranean river catchment (the Turia river, Spain) regarding heavy metals potential contamination

    Science.gov (United States)

    Andreu, Vicente; Gimeno-García, Eugenia; Pascual-Aguilar, Juan Antonio

    2015-04-01

    One important source of freshwater to population are fluvial courses, but they receive contaminants by different ways, usually frorm wastewaters and difuse pollution. The fluvial sedimentary phase can act as resevoir that accumulate contaminants fixing them or allowing their decomposition or metabolization. However, environmental changes or human induced ones, could favour their release to the environment. In this work, seven heavy metals were monitored in soils, waters and sediments of the Turia River catchment. Along the river, 22 zones were selected for sampling according different lithologies, land uses, size of populations and the proximity to waste waters treatment plants (WWTPs), from the headwaters to the mouth. The selected metals (Cd, Co, Cr, Cu, Pb, Ni and Zn) were analysed to determine its total and extractable contents in soils, water and sediments. Total content of metals was extracted by microwave acid digestion and the extractable fraction in soils and sediments by treatment with EDTA. Atomic Absorption Spectrometry, using graphite furnace when necessary, was used for the determination of all metals. Metal values in waters are below the limits established by the EU legislation. As in waters, the sediments show highest values mainly in zones 10 and 22, close to urban areas, reaching values of 172.86 mg/kg for Pb, or 58.34 mg/kg for Cr. However, zone 2 near in the headwaters, and supposedly of reference for the River authorities, shows the highest values of zinc (96.96 mg/kg). Regarding the available/extractable fraction of the metals, the maximum values were observeg in zone 22 too, reching in the case of Pb 59.60 mg/kg. The percentage of available metal in the sediments of the studied zones vary between 15 and 40% for Cu, Pb and Zn, being the higher than 60% for Pb and Zn in zone 8 near the city of Teruel. In soils, the higest levels of total and extractable Cd, Co, Cr and Ni were determined in the zones 11 and 12, near the Benageber reservoir where

  19. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: Physiographic Provinces

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This tabular data set represents the area of each physiographic province (Fenneman and Johnson, 1946) in square meters, compiled for every MRB_E2RF1 catchment of...

  20. An assessment of the impact of different land use activities on water quality in the upper Olifants River catchment

    CSIR Research Space (South Africa)

    Dabrowski, James M

    2013-04-01

    Full Text Available use activities in the catchment. In addition, once-off sampling was conducted at a number of sites located downstream of current mining, abandoned mining, agriculture, wastewater treatment works (WWTWs) and industry. Nutrient concentrations were...

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

    Directory of Open Access Journals (Sweden)

    Nigussie Ayehu Asrie

    2016-06-01

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

  2. Water Quality Changes during Rapid Urbanization in the Shenzhen River Catchment: An Integrated View of Socio-Economic and Infrastructure Development

    Directory of Open Access Journals (Sweden)

    Hua-peng Qin

    2014-10-01

    Full Text Available Surface water quality deterioration is a serious problem in many rapidly urbanizing catchments in developing countries. There is currently a lack of studies that quantify water quality variation (deterioration or otherwise due to both socio-economic and infrastructure development in a catchment. This paper investigates the causes of water quality changes over the rapid urbanization period of 1985–2009 in the Shenzhen River catchment, China and examines the changes in relation to infrastructure development and socio-economic policies. The results indicate that the water quality deteriorated rapidly during the earlier urbanization stages before gradually improving over recent years, and that rapid increases in domestic discharge were the major causes of water quality deterioration. Although construction of additional wastewater infrastructure can significantly improve water quality, it was unable to dispose all of the wastewater in the catchment. However, it was found that socio-economic measures can significantly improve water quality by decreasing pollutant load per gross regional production (GRP or increasing labor productivity. Our findings suggest that sustainable development during urbanization is possible, provided that: (1 the wastewater infrastructure should be constructed timely and revitalized regularly in line with urbanization, and wastewater treatment facilities should be upgraded to improve their nitrogen and phosphorus removal efficiencies; (2 administrative regulation policies, economic incentives and financial policies should be implemented to encourage industries to prevent or reduce the pollution at the source; (3 the environmental awareness and education level of local population should be increased; (4 planners from various sectors should consult each other and adapt an integrated planning approach for socio-economic and wastewater infrastructure development.

  3. Sub-daily variability of suspended sediment fluxes in small mountainous catchments - implications for community-based river monitoring

    Science.gov (United States)

    Duvert, C.; Gratiot, N.; Némery, J.; Burgos, A.; Navratil, O.

    2010-10-01

    Accurate estimates of suspended sediment yields depend on effective monitoring strategies. In mountainous environments undergoing intense seasonal precipitation, the implementation of such monitoring programs relies primarily on a rigorous study of the temporal variability of fine sediment transport. This investigation focuses on seasonal and short-term sediment variability in a subhumid region of the Mexican Volcanic Belt. Intensive hydrosedimentary monitoring was conducted during one year on four contrasting catchments (3 to 630 km2). Analyses revealed significant temporal variability in suspended sediment export over various time scales, with between 63 and 97% of the annual load exported in as little as 2% of the time. Statistical techniques were used to evaluate the sampling frequency required to get reliable annual sediment yield estimates at the four sites. A bi-daily sampling would be required at the outlet of the 630-km2 catchment, whereas in the three smaller catchments (3-12 km2), the achievement of accurate estimates would inevitably require hourly monitoring. At the larger catchment scale, analysis of the sub-daily variability of fine sediment fluxes showed that the frequency of sampling could be lowered by up to 100% (i.e. from bi-daily to daily) if considering a specific and regular sampling time in the day. In contrast, conducting a similar sampling strategy at the three smaller catchments could lead to serious misinterpretation (i.e. up to 1000% error). Our findings emphasise the importance of an analysis of the sub-daily variability of sediment fluxes in mountainous catchments. Characterising this variability may offer useful insights for improving the effectiveness of community-based monitoring strategies in rural areas of developing countries. In regions where historical records based on discrete sampling are available, it may also help assessing the quality of past flux estimates. Finally, the study confirms the global necessity of acquiring

  4. Sub-daily variability of suspended sediment fluxes in small mountainous catchments &ndash implications for community-based river monitoring

    Science.gov (United States)

    Duvert, C.; Gratiot, N.; Némery, J.; Burgos, A.; Navratil, O.

    2011-03-01

    Accurate estimates of suspended sediment yields depend on effective monitoring strategies. In mountainous environments undergoing intense seasonal precipitation, the implementation of such monitoring programs relies primarily on a rigorous study of the temporal variability of fine sediment transport. This investigation focuses on seasonal and short-term variability in suspended sediment flux in a subhumid region of the Mexican Volcanic Belt. Intensive monitoring was conducted during one year in four contrasting catchments (3 to 630 km2). Analyses revealed significant temporal variability in suspended sediment export over various time scales, with between 63 and 97% of the annual load exported in as little as 2% of the time. Statistical techniques were used to evaluate the sampling frequency required to get reliable estimates of annual sediment yield at the four sites. A bi-daily sampling scheme would be required at the outlet of the 630 km2 catchment, whereas in the three smaller catchments (3-12 km2), accurate estimates would inevitably require hourly monitoring. At the larger catchment scale, analysis of the sub-daily variability of fine sediment fluxes showed that the frequency of sampling could be lowered by up to 100% (i.e. from bi-daily to daily) if a specific and regular sampling time in the day was considered. In contrast, conducting a similar sampling strategy at the three smaller catchments could lead to serious misinterpretation (i.e. up to 1000% error). Our findings emphasise the importance of an analysis of the sub-daily variability of sediment fluxes in mountainous catchments. Characterising this variability may offer useful insights for improving the effectiveness of community-based monitoring strategies in rural areas of developing countries. In regions where historical records based on discrete sampling are available, it may also help assessing the quality of past flux estimates. Finally, the study confirms the global necessity of acquiring more

  5. Sub-daily variability of suspended sediment fluxes in small mountainous catchments – implications for community-based river monitoring

    Directory of Open Access Journals (Sweden)

    O. Navratil

    2010-10-01

    Full Text Available Accurate estimates of suspended sediment yields depend on effective monitoring strategies. In mountainous environments undergoing intense seasonal precipitation, the implementation of such monitoring programs relies primarily on a rigorous study of the temporal variability of fine sediment transport. This investigation focuses on seasonal and short-term sediment variability in a subhumid region of the Mexican Volcanic Belt. Intensive hydrosedimentary monitoring was conducted during one year on four contrasting catchments (3 to 630 km2. Analyses revealed significant temporal variability in suspended sediment export over various time scales, with between 63 and 97% of the annual load exported in as little as 2% of the time. Statistical techniques were used to evaluate the sampling frequency required to get reliable annual sediment yield estimates at the four sites. A bi-daily sampling would be required at the outlet of the 630-km2 catchment, whereas in the three smaller catchments (3–12 km2, the achievement of accurate estimates would inevitably require hourly monitoring. At the larger catchment scale, analysis of the sub-daily variability of fine sediment fluxes showed that the frequency of sampling could be lowered by up to 100% (i.e. from bi-daily to daily if considering a specific and regular sampling time in the day. In contrast, conducting a similar sampling strategy at the three smaller catchments could lead to serious misinterpretation (i.e. up to 1000% error. Our findings emphasise the importance of an analysis of the sub-daily variability of sediment fluxes in mountainous catchments. Characterising this variability may offer useful insights for improving the effectiveness of community-based monitoring strategies in rural areas of developing countries. In regions where historical records based on discrete sampling are available, it may also help assessing the quality of past flux estimates. Finally, the study confirms the global

  6. Case Study: Effect of Climatic Characterization on River Discharge in an Alpine-Prealpine Catchment of the Spanish Pyrenees Using the SWAT Model

    Directory of Open Access Journals (Sweden)

    Leticia Palazón

    2016-10-01

    Full Text Available The new challenges in assessment of water resources demand new approaches and tools, such as the use of hydrologic models, which could serve to assist managers in the prediction, planning and management of catchment water supplies in view of increased demand of water for irrigation and climatic change. Good characterization of the spatial patterns of climate variables is of paramount importance in hydrological modelling. This is especially so when modelling mountain environments which are characterized by strong altitudinal climate gradients. However, very often there is a poor distribution of climatic stations in these areas, which in many cases, results in under representation of high altitude areas with respect to climatic data. This results in the poor performance of the models. In the present study, the Soil and Water Assessment Tool (SWAT model was applied to the Barasona reservoir catchment in the Central Spanish Pyrenees in order to assess the influence of different climatic characterizations in the monthly river discharges. Four simulations with different input data were assessed, using only the available climate data (A1; the former plus one synthetic dataset at a higher altitude (B1; and both plus the altitudinal climate gradient (A2 and B2. The model’s performance was evaluated against the river discharges for the representative periods of 2003–2005 and 1994–1996 by means of commonly used statistical measures. The best results were obtained using the altitudinal climate gradient alone (scenario A2. This study provided insight into the importance of taking into account the sources and the spatial distribution of weather data in modelling water resources in mountainous catchments.

  7. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: NLCD 2001 Tree Canopy

    Science.gov (United States)

    Wieczorek, Michael; LaMotte, Andrew E.

    2010-01-01

    This tabular data set represents the mean percent tree canopy from the Canopy Layer of the National Land Cover Dataset 2001 (LaMotte and Wieczorek, 2010), compiled for every MRB_E2RF1 catchment of Major River Basins (MRBs, Crawford and others, 2006). The source data set represents tree canopy percentage for the conterminous United States for 2001. The Canopy Layer of the National Land Cover Data Set for 2001 was produced through a cooperative project conducted by the Multi-Resolution Land Characteristics (MRLC) Consortium. The MRLC Consortium is a partnership of Federal agencies (http://www.mrlc.gov), consisting of the U.S. Geological Survey (USGS), the National Oceanic and Atmospheric Administration (NOAA), the U.S. Environmental Protection Agency (USEPA), the U.S. Department of Agriculture (USDA), the U.S. Forest Service (USFS), the National Park Service (NPS), the U.S. Fish and Wildlife Service (USFWS), the Bureau of Land Management (BLM), and the USDA Natural Resources Conservation Service (NRCS). The MRB_E2RF1 catchments are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering New England and Mid-Atlantic (MRB1), South Atlantic-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great basin (MRB6), the Pacific Northwest (MRB7) river basins, and California (MRB8).

  8. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: NLCD 2001 Imperviousness

    Science.gov (United States)

    Wieczorek, Michael; LaMotte, Andrew E.

    2010-01-01

    This tabular data set represents the mean percent impervious surface from the Imperviousness Layer of the National Land Cover Dataset 2001, (LaMotte and Wieczorek, 2010), compiled for every MRB_E2RF1 catchment of selected Major River Basins (MRBs, Crawford and others, 2006). The source data set represents imperviousness for the conterminous United States for 2001. The Imperviousness Layer of the National Land Cover Data Set for 2001 was produced through a cooperative project conducted by the Multi-Resolution Land Characteristics (MRLC) Consortium. The MRLC Consortium is a partnership of Federal agencies (http://www.mrlc.gov), consisting of the U.S. Geological Survey (USGS), the National Oceanic and Atmospheric Administration (NOAA), the U.S. Environmental Protection Agency (USEPA), the U.S. Department of Agriculture (USDA), the U.S. Forest Service (USFS), the National Park Service (NPS), the U.S. Fish and Wildlife Service (USFWS), the Bureau of Land Management (BLM), and the USDA Natural Resources Conservation Service (NRCS). The MRB_E2RF1 catchments are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002;Brakebill and others, 2011). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering New England and Mid-Atlantic (MRB1), South Atlantic-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great basin (MRB6), the Pacific Northwest (MRB7) river basins, and California (MRB8).

  9. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: NLCD 2001 Land Use and Land Cover

    Science.gov (United States)

    Wieczorek, Michael; LaMotte, Andrew E.

    2010-01-01

    This tabular data set represents the estimated area of land use and land cover from the National Land Cover Dataset 2001 (LaMotte, 2008), compiled for every MRB_E2RF1 catchment of the Major River Basins (MRBs, Crawford and others, 2006). The source data set represents land use and land cover for the conterminous United States for 2001. The National Land Cover Data Set for 2001 was produced through a cooperative project conducted by the Multi-Resolution Land Characteristics (MRLC) Consortium. The MRLC Consortium is a partnership of Federal agencies (http://www.mrlc.gov), consisting of the U.S. Geological Survey (USGS), the National Oceanic and Atmospheric Administration (NOAA), the U.S. Environmental Protection Agency (USEPA), the U.S. Department of Agriculture (USDA), the U.S. Forest Service (USFS), the National Park Service (NPS), the U.S. Fish and Wildlife Service (USFWS), the Bureau of Land Management (BLM), and the USDA Natural Resources Conservation Service (NRCS). The MRB_E2RF1 catchments are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering the South Atlantic-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5) and the Pacific Northwest (MRB7) river basins.

  10. Tracing the catchment-scale hydrology of polygonal tundra and implications for lateral fluxes of carbon and nitrogen, Lena River Delta, Siberia

    Science.gov (United States)

    Runkle, Benjamin R. K.; Helbig, Manuel; Knoblauch, Christian; Kutzbach, Lars

    2014-05-01

    Surface-water hydrology changes the thermal regime of permafrost, carries varying amounts of nutrients depending on its flowpath, and provides a fuel for biogeochemical reactions, including the biological production of methane and carbon dioxide by soil microbes. In this work we present the findings of hydrological investigations in the ice-wedge polygon tundra of the Samoylov Research Island in Russia's Lena River Delta. We compare the catchment-scale behaviour of two adjacent watersheds through stable isotope analysis conducted over two years of sampling (2012-13). This work also incorporates the use of conservative natural tracers such as silica concentration and sheds light on mechanisms for the transport of dissolved organic carbon into the Lena River system. Hydrological discharge measurements taken over three years (2011-13) reveal generally similar patterns in rainfall response and permafrost thaw between two adjacent watersheds - one smaller (0.02 km2) and dominantly comprised of the characteristic polygonal tundra and the second larger one (0.6 km2) also containing two large surface-water reservoirs, namely a degraded ice-wedge network and a lake. However, stable isotope measurements of hydrogen (δD) and oxygen (δ18O) reveal that the latter watershed maintains a significant surface-water isotopic signature throughout the summer period, with greater influence of evaporation on watershed dynamics. The smaller, characteristic polygon catchment shows ever-increasing influence of deeper flow paths as the thaw depth increases over the season. These small catchments release low amounts of dissolved organic carbon and nitrogen both in terms of concentration (carbon budget (water, carbon, and energy cycles. Furthermore, modeling strategies will benefit from simpler process-based representations of landscape processes when upscaling to examine regional landscape-atmosphere interactions.

  11. Phylogeographic analysis of the true lemurs (genus Eulemur) underlines the role of river catchments for the evolution of micro-endemism in Madagascar.

    Science.gov (United States)

    Markolf, Matthias; Kappeler, Peter M

    2013-11-14

    Due to its remarkable species diversity and micro-endemism, Madagascar has recently been suggested to serve as a biogeographic model region. However, hypothesis-based tests of various diversification mechanisms that have been proposed for the evolution of the island's micro-endemic lineages are still limited. Here, we test the fit of several diversification hypotheses with new data on the broadly distributed genus Eulemur using coalescent-based phylogeographic analyses. Time-calibrated species tree analyses and population genetic clustering resolved the previously polytomic species relationships among eulemurs. The most recent common ancestor of eulemurs was estimated to have lived about 4.45 million years ago (mya). Divergence date estimates furthermore suggested a very recent diversification among the members of the "brown lemur complex", i.e. former subspecies of E. fulvus, during the Pleistocene (0.33-1.43 mya). Phylogeographic model comparisons of past migration rates showed significant levels of gene flow between lineages of neighboring river catchments as well as between eastern and western populations of the redfronted lemur (E. rufifrons). Together, our results are concordant with the centers of endemism hypothesis (Wilmé et al. 2006, Science 312:1063-1065), highlight the importance of river catchments for the evolution of Madagascar's micro-endemic biota, and they underline the usefulness of testing diversification mechanisms using coalescent-based phylogeographic methods.

  12. The Demonstration Test Catchment Approach to Land and Water Management in the river Eden Watershed, UK. (Invited)

    Science.gov (United States)

    Jonczyk, J.; Quinn, P. F.; Haygarth, P.; Reaney, S.; Wilkinson, M.; Burke, S.; McGonigle, D.; Harris, B.

    2010-12-01

    The Demonstration Test Catchment (DTC) initiative is a five year project to address pollution issues in catchments. The initiative will study the wider environmental problems suffered by catchments which are under intense farming pressures and potential climate change impacts. The UK Department for Food, Agriculture and Rural Affairs (Defra) in partnership with the Environment Agency for England and Wales (EA) have funded this initiative to answer key policy concerns in catchments. The first key step has been the establishment of a ‘research platform’ at three catchments in the UK (The Eden, Wensum and Hampshire Avon) whereby funding of 9.3 million dollars has gone into funding new equipment and pollution sampling regimes have been established. Within each catchment between three and four, 8-10km2 sub-catchments have been established. The experimental design and thinking for DTCs will be explained fully in this paper. The next phase of the project will install an extensive suite of land management and pollution mitigation interventions. In parallel to this monitoring work, a full knowledge exchange package will seek to engage with farmers, the rural community and understand the governance regime at the broader catchment scale. There is also a need for a modelling component to upscale the findings to the whole of the UK. Whilst this is an ambitious goal, there is a very basic commitment of working with rural communities to come up with real solutions that will help underpin effective policy making for the future. The research platform covers a multi-scale approach to the monitoring strategy that will allow local grouping of mitigation measures to be studied local in terms of impact and propagated to the catchment scale. Even with high level of funding, the DTC can only fully instrument a catchment of 8-10km2. Beyond this scale, the EA and the standard catchment monitoring will continue as normal. The focus here is to prove that mitigation can be achieved within

  13. Sediment Budget Analysis and Hazard Assessment in the Peynin, a Small Alpine Catchment (Upper Guil River, Southern Alps, France)

    Science.gov (United States)

    Carlier, Benoit; Arnaud-Fassetta, Gilles; Fort, Monique; Bouccara, Fanny; Sourdot, Grégoire; Tassel, Adrien; Lissak, Candide; Betard, François; Cossart, Etienne; Madelin, Malika; Viel, Vincent; Charnay, Bérengère; Bletterie, Xavier

    2014-05-01

    The upper Guil catchment (Southern Alps) is prone to hydro-geomorphic hazards. Major hazards are related to catastrophic floods, with an amplification of their impacts due to strong hillslope-channel connectivity as observed in 1957 and 2000. In both cases, the rainfall intensity, aggravated by the pre-existing saturated soils, explained the instantaneous response of the fluvial system, such as destabilisation of slopes, high sediment discharge, and subsequent damages to exposed structures and settlements present in the floodplain and at confluence sites. The Peynin junction with the Guil River is one of these sites, where significant land-use change during the last decades in relation to the development of handicraft and tourism economy has increased debris flow threat to population. Here, we adopt a sediment budget analysis aimed at better understanding the functioning of this small subcatchment. This latter offers a combination of factors that favour torrential and gravitational activity. It receives abundant and intense rainfall during "Lombarde" events (moist air mass from Mediterranean Sea). Its elongated shape and small surface area (15 km²) together with asymmetric slopes (counter dip slope on the left bank) accelerate runoff on a short response time. In addition highly tectonised shaly schists supply a large volume of debris (mostly platy clasts and fine, micaceous sediment). The objectives of this study, carried out in the frame of SAMCO (ANR) project, are threefold: Identify the different sediment storages; Characterise the processes that put sediment into motion; Quantify volumes of sediment storages. We produced a geomorphic map using topographic surveys and aerial photos in order to locate the different sediment storage types and associated processes. This analysis was made with respect to geomorphic coupling and sediment flux activity. In terms of surface area, the dominant landforms in the valley were found to be mass wasting, talus slopes and

  14. Effect of Agricultural Practices on Hydrology and Water Chemistry in a Small Irrigated Catchment, Yakima River Basin, Washington

    Science.gov (United States)

    McCarthy, Kathleen A.; Johnson, Henry M.

    2009-01-01

    The role of irrigation and artificial drainage in the hydrologic cycle and the transport of solutes in a small agricultural catchment in central Washington's Yakima Valley were explored using hydrologic, chemical, isotopic, age-dating, and mineralogical data from several environmental compartments, including stream water, ground water, overland flow, and streambed pore water. A conceptual understanding of catchment hydrology and solute transport was developed and an inverse end-member mixing analysis was used to further explore the effects of agriculture in this small catchment. The median concentrations of major solutes and nitrates were similar for the single field site and for the catchment outflow site, indicating that the net effects of transport processes for these constituents were similar at both scales. However, concentrations of nutrients were different at the two sites, suggesting that field-scale variations in agricultural practices as well as nearstream and instream biochemical processes are important components of agricultural chemical transformation and transport in this catchment. This work indicates that irrigation coupled with artificial drainage networks may exacerbate the ecological effects of agricultural runoff by increasing direct connectivity between fields and streams and minimizing potentially mitigating effects (denitrification and dilution, for example) of longer subsurface pathways.

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

    Science.gov (United States)

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

    2010-05-01

    Introduction: This study was conducted with in the framework of the VLIR-OI project with the aim of making contributions to the Diagnosis and Remediation of Land Degradation Processes in the Riparian Zone of Lake Victoria Uganda in view of reducing sediment pollution of the Lake Waters with a special focus on the upper river Ruiz and Iguluibi catchments. The study seeks to investigate Sugarcane growing and cattle grazing as drivers to wetland degradation in light of the current farming systems and practices and their contributions to land degradation and pollution of the Lake Victoria waters. Vegetation especially wetlands improves the resistance to erosion. The removal of riparian vegetation tends to accelerate surface erosion as a result of human activities. Increased erosion with in the catchments due to clearing of wetlands for sugarcane growing and cattle grazing has caused adverse increased sedimentation, degraded the water quality, and reduced the water productivity of the Lake Victoria Basin. Methods: We conducted a qualitative and quantitative study to investigate Sugarcane growing and cattle grazing as drivers to wetland degradation in Uganda in light of the current farming systems and practices and their socio-economic contributions to wetland degradation and pollution of the Lake Victoria waters. Focus group discussions, key informant interviews, semi structured interviews and observations were undertaken with the relevant stakeholders in the community. Results: Findings reveal that in Iguluibi catchment, sugarcane growing is now a major activity indicating land use change since the 1990s. Community members said when planting sugarcane all vegetations including all trees are cut leaving the land bare to allow the tractor to clear the land for cultivation. This has left the land bare without any natural vegetation with increased erosion hence eventually loss of soil fertility and increased sediment pollution to the Lake Victoria waters. As a result of

  16. Land-use effects on fluxes of suspended sediment, nitrogen and phosphorus from a river catchment of the Great Barrier Reef, Australia

    Science.gov (United States)

    Hunter, Heather M.; Walton, Richard S.

    2008-07-01

    SummaryA 6-year study was conducted in the Johnstone River system in the wet tropics of north-eastern Australia, to address concerns that the Great Barrier Reef is at risk from elevated levels of suspended sediment (SS) and nutrients discharged from its river catchments. Aims were to quantify: (i) fluxes of SS, phosphorus (P) and nitrogen (N) exported annually from the catchment and (ii) the influence of rural land uses on these fluxes. Around 55% of the 1602 km2 catchment was native rainforest, with the reminder developed mainly for livestock and crop production. Water quality and stream flow were monitored at 16 sites, with the emphasis on sampling major runoff events. Monitoring data were used to calibrate a water quality model for the catchment (HSPF), which was run with 39 years of historical precipitation and evaporation data. Modelled specific fluxes from the catchment of 1.2 ± 1.1 t SS ha-1 y-1, 2.2 ± 1.8 kg P ha-1 y-1 and 11.4 ± 7.3 kg N ha-1y-1 were highly variable between and within years. Fluxes of SS and P were strongly dominated by major events, with 91% of SS and 84% of P exported during the highest 10% of daily flows. On average, sediment P comprised 81% of the total P flux. The N flux was less strongly dominated by major events and sediment N comprised 46% of total N exports. Specific fluxes of SS, N and P from areas receiving precipitation of 3545 mm y-1 were around 3-4 times those from areas receiving 1673 mm y-1. For a given mean annual precipitation, specific fluxes of SS and P from beef pastures, dairy pastures and unsewered residential areas were similar to those from rainforest, while fluxes from areas of sugar cane and bananas were 3-4 times higher. Specific fluxes of N from areas with an annual precipitation of 3545 mm ranged from 8.9 ± 6.5 kg N ha-1 y-1 (rainforest) to 72 ± 50 kg N ha-1 y-1 (unsewered residential). Aggregated across the entire catchment, disproportionately large fluxes of SS, total P and total N were derived from

  17. Hydro-meteorological functioning of the Eastern Andean Tropical Montane Cloud Forests: Insight from a paired catchment study in the Orinoco river basin highlands

    Science.gov (United States)

    Ramirez, Beatriz; Teuling, Adriaan J.; Ganzeveld, Laurens; Leemans, Rik

    2016-04-01

    Tropical forests regulate large scale precipitation patterns and catchment-scale streamflow, while tropical mountains influence runoff by orographic effects and snowmelt. Along tropical elevation gradients, these climate/ecosystem/hydrological interactions are specific and heterogeneous. These interactions are poorly understood and represented in hydro-meteorological monitoring networks and regional or global earth system models. A typical case are the South American Tropical Montane Cloud Forests (TMCF), whose water balance is strongly driven by fog persistence. This also depends on local and up wind temperature and moisture, and changes in this balance alter the impacts of changes in land use and climate on hydrology. These TMCFs were until 2010 only investigated up to 350km from the coast. Continental TMCFs are largely ignored. This gap is covered by our study area, which is part of the Orinoco river basin highlands and located on the northern Eastern Andes at an altitudinal range of 1550 to 2300m a.s.l. The upwind part of our study area is dominated by lowland savannahs that are flooded seasonally. Because meteorological stations are absent in our study area, we first describe the spatial and seasonal meteorological variability and analyse the corresponding catchment hydrology. Our hydro-meteorological data set is collected at three gauged neighbouring catchments with contrasting TMCF/grassland cover from June 2013 to May 2014 and includes hourly solar radiation, temperature, relative humidity, wind speed, precipitation, soil moisture and runoff measurements. We compare our results with recent TCMF studies in the eastern Andean highlands in the Amazon basin. The studied elevational range always shows wetter conditions at higher elevations. This indicates a positive relation between elevation and fog or rainfall persistence. Lower elevations are more seasonally variable. Soil moisture data indicate that TMCFs do not use persistently more water than grasslands

  18. A framework and a set of tools called Nutting models to estimate retention capacities and loads of nitrogen and phosphorus in rivers at catchment and national level (France)

    Science.gov (United States)

    Legeay, Pierre-Louis; Moatar, Florentina; Dupas, Rémi; Gascuel-Odoux, Chantal

    2016-04-01

    The Nutting-N and Nutting-P models (Dupas et al., 2013, 2015) have been developed to estimate Nitrogen and Phosphorus nonpoint-source emissions to surface water, using readily available data. These models were inspired from US model SPARROW (Smith al., 1997) and European model GREEN (Grizzetti et al., 2008), i.e. statistical approaches consisting of linking nitrogen and phosphorus surplus to catchment's land and rivers characteristics to find the catchment relative retention capacities. The nutrient load (L) at the outlet of each catchment is expressed as: L=R*(B*DS+PS) [1] where DS is diffuse sources (i.e. surplus in kg.ha-1/yr-1 for N, P storage in soil for P), PS is point sources from domestic and industrial origin (kg.ha-1.yr-1), R and B are the river system and basin reduction factor, respectively and they combine observed variables and calibrated parameters. The model was calibrated on independent catchments for the 2005-2009 and 2008-2012 periods. Variables were selected according to Bayesian Information Criterion (BIC) in order to optimize the predictive performance of the models. From these basic models, different improvements have been realized to build a framework and a set of tools: 1) a routing module has been added in order to improve estimations on 4 or 5 stream order, i.e. upscaling the basic Nutting approach; 2) a territorial module, in order to test the models at local scale (from 500 to 5000 km²); 3) a seasonal estimation has been investigated. The basic approach as well territorial application will be illustrated. These tools allow water manager to identify areas at risk where high nutrients loads are estimated, as well areas where retention is potentially high and can buffer high nutrient sources. References Dupas R., Curie F., Gascuel-Odoux C., Moatar F., Delmas M., Parnaudeau, V., Durand P., 2013. Assessing N emissions in surface water at the national level: Comparison of country-wide vs. regionalized models. Science of the Total Environment

  19. 10Be constrains the sediment sources and sediment yields to the Great Barrier Reef from the tropical Barron River catchment, Queensland, Australia

    Science.gov (United States)

    Nichols, K. K.; Bierman, P. R.; Rood, D. H.

    2014-12-01

    Estimates of long-term, background sediment generation rates place current and future sediment fluxes to the Great Barrier Reef in context. Without reliable estimates of sediment generation rates and without identification of the sources of sediment delivered to the reef prior to European settlement (c. 1850), determining the necessity and effectiveness of contemporary landscape management efforts is difficult. Using the ~2100-km2 Barron River catchment in Queensland, Australia, as a test case, we use in situ-produced 10Be to derive sediment generation rate estimates and use in situ and meteoric 10Be to identify the source of that sediment, which enters the Coral Sea near Cairns. Previous model-based calculations suggested that background sediment yields were up to an order of magnitude lower than contemporary sediment yields. In contrast, in situ 10Be data indicate that background (43 t km-2 y-1) and contemporary sediment yields (~45 t km-2 y-1) for the Barron River are similar. These data suggest that the reef became established in a sediment flux similar to what it receives today. Since western agricultural practices increased erosion rates, large amounts of sediment mobilized from hillslopes during the last century are probably stored in Queensland catchments and will eventually be transported to the coast, most likely in flows triggered by rare but powerful tropical cyclones that were more common before European settlement and may increase in strength as climate change warms the south Pacific Ocean. In situ and meteoric 10Be concentrations of Coral Sea beach sand near Cairns are similar to those in rivers on the Atherton Tablelands, suggesting that most sediment is derived from the extensive, low-gradient uplands rather than the steep, more rapidly eroding but beach proximal escarpment.

  20. Impact of recent land use and climate changes on sediment and pollutant redistribution in small catchments within the Seim River Basin (Kursk Region, European Russia)

    Science.gov (United States)

    Belyaev, Vladimir; Ivanova, Nadezda; Ivanov, Maxim; Bondarev, Valery; Lugovoy, Nikolay; Aseeva, Elena; Malyutina, Alisa

    2017-04-01

    It is widely accepted that changes of land use or climatic conditions can exert profound impacts on river basin sediment budgets and associated particle-bound pollutant redistribution patterns at different temporal and spatial scales. It can be especially difficult to distinguish relative importance of particular factors when the changes occur more or less within the same time frame. Such situation is typical for most parts of the agricultural belt of Russia, as period of economic downfall associated with collapse of the former Soviet Union and later gradual recovery practically coincides with period of the most significant climate changes observed in the late 20th - early 21st Centuries. Therefore it seems interesting and important to consider possible changes of fluvial systems responses within the period from 1980s to the present under different spatial scales. Here we plan to present results of the almost 10-year period of investigations of sediment and associated pollutant redistribution spatial and temporal patterns in several small catchments within the Seim River Basin (Kursk Region, European Russia). Studies dealt with small catchments and small river basins in scales from 1-2 km2 to 200 km2 located in different parts of the main basin. Works carried out included detailed geomorphic surveys, soil and sediment sections and cores description and sampling in different locations (undisturbed, erosion, transit, deposition), remote sensing data and morphometric analysis, soil erosion modeling. Integration of the results allowed constructing sediment budgets, in most cases, for two time intervals (approximately - pre-1986 and post-1986, as the Chernobyl-derived 137Cs has been an important time mark at all the case study sites). It has been found out that combination of several major tendencies including abandonment and recultivation of arable fields, notable decrease of winter-frozen topsoil layer thickness and increase of heavy summer rainstorms magnitude and

  1. Calculation of Sediment yield at the S 7-4 catchment of the Shirindareh Watershed of Iran using the River Basins model

    Science.gov (United States)

    Spalevic, Velibor; Barovic, Goran; Vujacic, Dusko; Mijanovic, Dragica; Curovic, Milic; Tanaskovik, Vjekoslav; Behzadfar, Morteza

    2016-04-01

    Soil erosion is driven by complex processes involving detachment of material caused by raindrops and flow tractions, which is further transported by the wind or by the water flow. The region of Shirindareh Watershed of Iran is particularly prone to erosion because it is subject to long dry periods followed by heavy erosive rainfalls, falling on steep slopes with soils prone to erosion. The identification of areas that are vulnerable to those processes is needed for improving our knowledge about the extent of the areas affected and for developing measures to control the problem. In our opinion, models can be very supportive tools for understanding of the soil erosion and sediment transport at the watershed scale. This study aims to illustrate the possibility in computing the runoff and sediment yield at the catchment scale using the River Basins model of Spalevic, which is based on the Erosion Potential Method of Garilovic. We apply the mode in the S 7-4 catchment of the Shirindareh Watershed of Iran using the computer graphic model, which allowed the quantification of the environmental effects of erosion and the land use measures applied at the studied area. Model calculations showed that the calculated peak discharge from the river basin was 61 m3 s-1 for the incidence of 100 years and the net soil loss was 5806 m3 per year, specific 159 m3km-2 per year. According to Gavrilovic this amount of soil loss indicates very weak erosion category. The method we used in this study can also be of interest for soil erosion modelling in other basins. The proper implementation of best management practices and control measures are crucial for protecting land resources in the Shirindareh Watershed and the other river basins with similar physical - geographical conditions.

  2. Quantifying the effect of catchment land-use and water nutrient concentrations on freshwater river and stream biodiversity

    NARCIS (Netherlands)

    Weijters, M.J.; Janse, J.H.; Alkemade, J.R.M.; Verhoeven, J.T.A.

    2009-01-01

    A major threat to freshwater taxon diversity is the alteration of natural catchment Land use into agriculture, industry or urban areas and the associated eutrophication of the water. In order to stop freshwater biodiversity loss, it is essential to quantify the relationships between freshwater

  3. Estimating shallow groundwater availability in small catchments using streamflow recession and instream flow requirements of rivers in South Africa

    Science.gov (United States)

    Ebrahim, Girma Y.; Villholth, Karen G.

    2016-10-01

    Groundwater is an important resource for multiple uses in South Africa. Hence, setting limits to its sustainable abstraction while assuring basic human needs is required. Due to prevalent data scarcity related to groundwater replenishment, which is the traditional basis for estimating groundwater availability, the present article presents a novel method for determining allocatable groundwater in quaternary (fourth-order) catchments through information on streamflow. Using established methodologies for assessing baseflow, recession flow, and instream ecological flow requirement, the methodology develops a combined stepwise methodology to determine annual available groundwater storage volume using linear reservoir theory, essentially linking low flows proportionally to upstream groundwater storages. The approach was trialled for twenty-one perennial and relatively undisturbed catchments with long-term and reliable streamflow records. Using the Desktop Reserve Model, instream flow requirements necessary to meet the present ecological state of the streams were determined, and baseflows in excess of these flows were converted into a conservative estimates of allocatable groundwater storages on an annual basis. Results show that groundwater development potential exists in fourteen of the catchments, with upper limits to allocatable groundwater volumes (including present uses) ranging from 0.02 to 3.54 × 106 m3 a-1 (0.10-11.83 mm a-1) per catchment. With a secured availability of these volume 75% of the years, variability between years is assumed to be manageable. A significant (R2 = 0.88) correlation between baseflow index and the drainage time scale for the catchments underscores the physical basis of the methodology and also enables the reduction of the procedure by one step, omitting recession flow analysis. The method serves as an important complementary tool for the assessment of the groundwater part of the Reserve and the Groundwater Resource Directed Measures in

  4. Impacts of climate change on the seasonality of low flows in 134 catchments in the river Rhine basin using an ensemble of bias-corrected regional climate simulations. Discussion paper

    NARCIS (Netherlands)

    Demirel, M.C.; Booij, M.J.; Hoekstra, A.Y.

    2013-01-01

    The impacts of climate change on the seasonality of low flows are analysed for 134 sub-catchments covering the River Rhine basin upstream of the Dutch–German border. Three seasonality indices for low flows are estimated, namely seasonality ratio (SR), weighted mean occurrence day (WMOD) and weighted

  5. Catchment-flowline network and selected model inputs for an enhanced and updated spatially referenced statistical assessment of dissolved-solids load sources and transport in streams of the Upper Colorado River Basin

    Science.gov (United States)

    Buto, Susan G.; Spangler, Lawrence E.; Flint, Alan L.; Flint, Lorraine E.

    2017-01-01

    This USGS data release consists of the synthetic stream network and associated catchments used to develop spatially referenced regressions on watershed attributes (SPARROW) model of dissolved-solids sources and transport in the Upper Colorado River Basin as well as geology and selected Basin Characterization Model (BCM) data used as input to the model.

  6. Dynamic seasonal nitrogen cycling in response to anthropogenic N-loading in a tropical catchment, Athi–Galana–Sabaki River, Kenya

    Directory of Open Access Journals (Sweden)

    T. R. Marwick

    2013-05-01

    Full Text Available As part of a broader study on the riverine biogeochemistry in the Athi–Galana–Sabaki (A–G–S River catchment (Kenya, we present data constraining the sources, transit and transformation of multiple nitrogen (N species as they flow through the A–G–S catchment (~47 000 km2. The data-set was obtained in August–September 2011, November 2011, and April–May 2012, covering the dry season, short-rain season and long-rain season respectively. Release of, largely untreated, waste water from the city of Nairobi had a profound impact on the biogeochemistry of the upper Athi river, leading to low dissolved oxygen (DO saturation levels (67–36%, high ammonium (NH4+ concentrations (1193–123 μmol L−1, and high dissolved methane (CH4 concentrations (6729–3765 nmol L−1. Total dissolved inorganic nitrogen (DIN concentrations entering the study area were highest during the dry season (1195 μmol L−1, while total DIN concentration was an order of magnitude lower during the short and long rain seasons (212 and 193 μmol L−1, respectively. During the rain seasons, low water residence time led to relatively minimal instream N-cycling prior to discharge to the ocean. Conversely, increased residence time during the dry season creates two differences comparative to wet season conditions, where (1 intense cycling and removal of DIN in the upper- to mid-catchment leads to significantly less DIN export during the dry season, and (2 as a result of the intense DIN cycling, dry season particulate N export is significantly enriched in the N stable isotope ratio (δ15NPN, strongly reflecting the dominance of organic matter as the prevailing source of riverine nitrogen. The rapid removal of NH4+ in the upper study area during the dry season was accompanied by a quantitatively similar production of NO3− and nitrous oxide (N2O downstream, pointing towards strong nitrification over this reach during the dry season. Nitrous oxide produced was rapidly

  7. Development of a river-groundwater interaction model and its application to a catchment in Northwestern China

    Science.gov (United States)

    Hu, Litang; Xu, Zongxue; Huang, Weidong

    2016-12-01

    The river-groundwater interaction is an important component of the hydrological cycle. This study develops an integrated river-GW model that uses a one-dimensional open channel flow model and a three-dimensional saturated GW flow model to describe the dynamic river-GW relationship at the basin scale, as well as groundwater flow and streamflow in arid regions. The model is tested with three cases, and the good agreement between the simulated and observed results demonstrates that the model can be used to simulate river-GW interactions. The integrated river-GW model is applied to the middle reaches of the Heihe River Basin and is calibrated using multi-source field data, including hydraulic heads from observation wells, streamflow, and spring flow. The case studies in the Heihe River Basin find that the following: (1) the river-GW relationships vary seasonally and spatially and depend on many factors, such as the river flow and GW uses; (2) in the middle reaches, the annual mean river-groundwater flux exchange from Yinluoxia to the Heihe Bridge is approximately 17% of the mean streamflow and increases to more than 49% from the Heihe Bridge to Zhengyixia; and (3) after the implementation of the water reallocation plan in 2000, the river-GW relationship in some reaches changed from a gaining stream to a losing stream due to the increase of GW abstraction. These findings suggest that GW pumpage should be controlled rationally and demonstrate that the integrated river-GW model can be used to analyse the temporal-spatial trends of river-groundwater interaction in arid regions.

  8. Preventable fine sediment export from the Burdekin River catchment reduces coastal seagrass abundance and increases dugong mortality within the Townsville region of the Great Barrier Reef, Australia.

    Science.gov (United States)

    Wooldridge, Scott A

    2017-01-30

    The coastal seagrass meadows in the Townsville region of the Great Barrier Reef are crucial seagrass foraging habitat for endangered dugong populations. Deteriorating coastal water quality and in situ light levels reduce the extent of these meadows, particularly in years with significant terrestrial runoff from the nearby Burdekin River catchment. However, uncertainty surrounds the impact of variable seagrass abundance on dugong carrying capacity. Here, I demonstrate that a power-law relationship with exponent value of -1 (R(2)~0.87) links mortality data with predicted changes in annual above ground seagrass biomass. This relationship indicates that the dugong carrying capacity of the region is tightly coupled to the biomass of seagrass available for metabolism. Thus, mortality rates increase precipitously following large flood events with a response lag of flood events. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Flood Analysis Using Hydrological Modeling. Case Study – The Flood In The Upper Catchment Of River Geru, Galaţi County, Romania

    Directory of Open Access Journals (Sweden)

    Balan Isabela

    2015-10-01

    Full Text Available This paper analyzes the flood that occurred between 11th and 13th of September 2013 in the upper catchment of the river Geru. The flood was simulated using the program Mike by DHI with the Unitary Hydrograph Method. As input data, we used the precipitation measured at the Automated Hydrological Sensor Station Cudalbi and radar precipitations. We analyzed the importance of accuracy for input data on the simulation results and the direct influence of setting the proper time steps in achieving the simulated discharge hydrograph. It appears that radar precipitations used as input data lead to a discharge hydrograph with low errors for amplitude and phase of the runoff peak.

  10. Validation of SMOS L1C and L2 Products and Important Parameters of the Retrieval Algorithm in the Skjern River Catchment, Western Denmark

    DEFF Research Database (Denmark)

    Bircher, Simone; Skou, Niels; Kerr, Yann H.

    2013-01-01

    The Soil Moisture and Ocean Salinity (SMOS) satellite with a passive L-band radiometer monitors surface soil moisture. In addition to soil moisture, vegetation optical thickness tau(NAD) is retrieved (L2 product) from brightness temperatures (T-B, L1C product) using an algorithm based on the L...... and the most sensitive algorithm parameters were analyzed by network and airborne campaign data collected within one SMOS pixel (44 km diameter). The SMOS retrieval is based on the prevailing low vegetation class. For the L1C comparison, T-B's were calculated from in situ soil moisture using L-MEB. Consistent......-band Microwave Emission of the Biosphere (L-MEB) model with initial guesses on the two parameters (derived from ECMWF products and ECOCLIMAP Leaf Area Index, respectively) and other auxiliary input. This paper presents the validation work carried out in the Skjern River Catchment, Denmark. L1C/L2 data...

  11. Watershed Modeling with ArcSWAT and SUFI2 In Cisadane Catchment Area: Calibration and Validation of River Flow Prediction

    Directory of Open Access Journals (Sweden)

    Iwan Ridwansyah

    2014-04-01

    Full Text Available Increasing of natural resources utilization as a result of population growth and economic development has caused severe damage on the watershed. The impacts of natural disasters such as floods, landslides and droughts become more frequent. Cisadane Catchment Area is one of 108 priority watershed in Indonesia. SWAT is currently applied world wide and considered as a versatile model that can be used to integrate multiple environmental processes, which support more effective watershed management and the development of better informed policy decision. The objective of this study is to examine the applicability of SWAT model for modeling mountainous catchments, focusing on Cisadane catchment Area in west Java Province, Indonesia. The SWAT model simulation was done for the periods of 2005 – 2010 while it used landuse information in 2009. Methods of Sequential Uncertainty Fitting ver. 2 (SUFI2 and combine with manual calibration were used in this study to calibrate a rainfall-runoff. The Calibration is done on 2007 and the validation on 2009, the R2 and Nash Sutchliffe Efficiency (NSE of the calibration were 0.71 and 0.72 respectively and the validation are 0.708 and 0.7 respectively. The monthly average of surface runoff and total water yield from the simulation were 27.7 mm and 2718.4 mm respectively. This study showed SWAT model can be a potential monitoring tool especially for watersheds in Cisadane Catchment Area or in the tropical regions. The model can be used for another purpose, especially in watershed management.

  12. Temporal variability of suspended sediment sources in an alpine catchment combining river/rainfall monitoring and sediment fingerprinting

    OpenAIRE

    Navratil, O.; Evrard, O.; Esteves, Michel; Legout, C.; Ayrault, S.; Nemery, J.; Mate-Marin, A.; .M. Ahmadi; Lefevre, I.; Poirel, A.; Bonte, P.

    2012-01-01

    Influence of the rainfall regime on erosion and transfer of suspended sediment in a 905-km(2) mountainous catchment of the southern French Alps was investigated by combining sediment monitoring, rainfall data, and sediment fingerprinting (based on geochemistry and radionuclide concentrations). Suspended sediment yields were monitored between October 2007 and December 2009 in four subcatchments (22-713km(2)). Automatic sediment sampling was triggered during floods to trace the sediment origin ...

  13. Sources of uncertainty in climate change impacts on river discharge and groundwater in a headwater catchment of the Upper Nile Basin, Uganda

    Directory of Open Access Journals (Sweden)

    D. G. Kingston

    2010-07-01

    Full Text Available The changing availability of freshwater resources is likely to be one of the most important consequences of projected 21st century climate change for both human and natural systems. However, substantial uncertainty remains regarding the precise impacts of climate change on water resources, due in part due to uncertainty in GCM projections of climate change. Here we explore the potential impacts of climate change on freshwater resources in a humid, tropical catchment (the River Mitano in the Upper Nile Basin of Uganda. Uncertainty associated with GCM structure and climate sensitivity is explored, as well as parameter specification within hydrological models. These aims are achieved by running pattern-scaled output from seven GCMs through a semi-distributed hydrological model of the catchment (developed using SWAT. Importantly, use of pattern-scaled GCM output allows investigation of specific thresholds of global climate change including the purported 2 °C threshold of "dangerous" climate change. In-depth analysis of results based on the HadCM3 GCM climate scenarios shows that annual river discharge first increases, then declines with rising global mean air temperature. A coincidental shift from a bimodal to unimodal discharge regime also results from a projected reduction in baseflow (groundwater discharge. Both of these changes occur after a 4 °C rise in global mean air temperature. These results are, however, highly GCM dependent, in both the magnitude and direction of change. This dependence stems primarily from projected differences in GCM scenario precipitation rather than temperature. GCM-related uncertainty is far greater than that associated with climate sensitivity or hydrological model parameterisation.

  14. Metal-fluxes characterization at a catchment scale: Study of mixing processes and end-member analysis in the Meca River watershed (SW Spain)

    Science.gov (United States)

    Cánovas, C. R.; Macías, F.; Olías, M.; López, R. Pérez; Nieto, J. M.

    2017-07-01

    Fluxes of acidity and contaminants from acid mine drainage (AMD) sources to the receiving surface water bodies were studied in a mining-impacted watershed (Meca River, SW Spain) using a novel methodology based on the joint application of EMMA and MIX codes. The application of EMMA and elemental ratios allowed delimiting the end-members responsible for water quality variations at a catchment scale. The further application of MIX quantified the significant impact of AMD on the river quality; less than 10% of AMD relative contribution is enough to maintain acidic conditions during most of the year. The mixing model also provided information about the element mobility, distinguishing those elements with a quasi-conservative behavior (e.g., Cu, Zn, Al, Co or Ni) from those affected by mineral precipitation/dissolution (e.g., K, Si, Na, Sr, Ca, Fe, Pb, or As). Floods are the main driver of dissolved and, mainly particulate, contaminants in the catchment. Thus, the first rainfall events in November only accounted for 19% of the annual Meca flow but yielded between 26 and 43% of the net acidity and dissolved metal loads (mainly, Fe, As and Pb). Concerning particulate transport, around 332 tons of particulate Fe, 49 tons of Al, 0.79 tons of As and 0.37 tons of Pb were recorded during these first floods. The particulate As concentration can be up to 34 times higher than the dissolved one during floods and between 2 and 4 times higher for Fe, Pb and Cr. This integrated modeling approach could be a promising and useful tool to face future restoration plans in derelict mines worldwide. This approach would allow prioritizing remedial measures, achieving an environmental and cost-effective restoration of degraded areas.

  15. Crop yield risk analysis and mitigation of smallholder farmers at quaternary catchment level: Case study of B72A in Olifants river basin, South Africa

    Science.gov (United States)

    Magombeyi, Manuel S.; Taigbenu, Akpofure E.

    Currently, Sub-Sahara is experiencing increased frequency of disasters either as floods or droughts which depletes the scarce resources available to sustain increasing populations. Success in preventing food shortages in the African continent can only be achieved by understanding the vulnerability and risk of the majority of smallholder farmers under rainfed and supplementary irrigation coupled with appropriate interventions. Increased frequency of floods, droughts and dry spells pose an increasing threat to the smallholder farmers’ food security and water resources availability in B72A quaternary catchment of the Olifants river basin in South Africa. This paper links maize crop yield risk and smallholder farmer vulnerability arising from droughts by applying a set of interdisciplinary indicators (physical and socio-economic) encompassing gender and institutional vulnerabilities. For the study area, the return period of droughts and dry spells was 2 years. The growing season for maize crop was 121 days on average. Soil water deficit during critical growth stages may reduce potential yields by up to 62%, depending on the length and severity of the moisture deficit. To minimize grain yield loss and avoid total crop failures from intra-seasonal dry spells, farmers applied supplementary irrigation either from river water or rainwater harvested into small reservoirs. Institutional vulnerability was evidenced by disjointed water management institutions with lack of comprehension of roles of higher level institutions by lower level ones. Women are most hit by droughts as they derived more than 90% of their family income from agriculture activities. An enhanced understanding of the vulnerability and risk exposure will assist in developing technologies and policies that conform to the current livelihood strategies of smallholder, resource-constrained farmers. Development of such knowledge base for a catchment opens avenues for computational modeling of the impacts of

  16. Effects of the "Conversion of Cropland to Forest and Grassland Program" on the water budget of the Jinghe River catchment in China.

    Science.gov (United States)

    Qiu, Guo Yu; Yin, Jing; Tian, Fei; Geng, Shu

    2011-01-01

    In 1999 China adopted the "Conversion of Cropland to Forest and Grassland Program" (CCFGP), a nationwide ecological recovery program, to minimize wide-scale soil erosion and vegetation degradation in China, as well as to improve water budgeting results. In the 10 yr since implementation, the CCFGP has resulted in the recovery and reforestation of >100,000 km of cropland and bare land, though the quantitative effect of this program on catchment water budget is not entirely clear. Therefore, we used the Soil and Water Assessment Tool to evaluate and quantify the effects of the CCFGP on the water budget of the Jinghe River catchment, a tributary of the Yellow River covering the central region of the Loess Plateau. Our results indicated that precipitation had dropped by 12.0% from the 1970s (611.6 mm) to the 2000s (538 mm) and that there was a corresponding 25.2% decrease in humidity index from 0.48 to 0.36. Before the CCFGP's implementation, forest and grassland had been decreasing, while bare land, cropland, and shrub land had been increasing. After the implementation of the CCFGP, the opposite trend was observed. Moreover, streamflow increased by about 15 and 20% for the upstream and middle stream subbasins, respectively, while soil water content also showed an obvious increase. Over the same period, evapotranspiration decreased by 5.2 and 13.5 mm and runoff decreased by 37.5 and 38.6% in the two subbasins. The same trends were obtained in the downstream subbasin, where changes were even greater. As a result of the reduced runoff and evapotranspiration, utilization of water resources was more efficient and ecological environment was improved under the CCFGP policy. Our results indicate the CCFGP resulted in a favorable ecological impact and should therefore be maintained.

  17. The River Systems in Small Catchments in the Context of the Horton’s and Schumm’s Laws – Implication for Hydrological Modelling. The Case Study of the Polish Carpathians

    Directory of Open Access Journals (Sweden)

    Bryndal Tomasz

    2015-03-01

    Full Text Available In ungauged catchments, flood hydrographs are usually simulated/reconstructed by simple rainfall-runoff and routing models. Horton’s and Schumm’s ratios serve as the input data for many of these models. In this paper, more than 800 Carpathian catchments (up to 35.2 km2 in area were investigated in context of the “Horton’s and Schumm’s laws”. Results reveal that the “law of stream number” and “law of stream areas” are fulfilled in almost all catchments. The mean that values of the bifurcation ratio (RB and the area ratio (RA reach 3.8 and 4.8, respectively, and are thus comparable to values reported in other regions of the world. However, the “law of stream lengths” is not fulfilled in more than half of the catchments, which is not consistent with many theoretical studies reported in the literature. Only 383 (48% catchments fulfill the “law of stream length”, with the mean value of the length ratio (RL=2.3. There was no relationship found between the geological/geomorphological settings that influence river system development and the spatial distribution of catchments where the “law of stream length” was or was not was fulfilled. A similar conclusion was reached for the spatial distribution of the RB, RL, and RA ratios. These results confirmed that the use of Horton’s and Schumm’s ratios for the evaluation of the influence of geological/geomorphological settings on the river system development is limited. Among the lumped hydrological models, those requiring the RB, RL, and RA ratios have been extensively studied over last decades. This study suggests that the application of these models may be limited in small catchment areas; therefore, more attention should be placed on the development of hydrological models where the RB, RL, and RA ratios are not necessary.

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

    Science.gov (United States)

    Wieczorek, Michael; LaMotte, Andrew E.

    2010-01-01

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

  19. Agricultural Rivers at Risk: Dredging Results in a Loss of Macroinvertebrates. Preliminary Observations from the Narew Catchment, Poland

    Directory of Open Access Journals (Sweden)

    Mateusz Grygoruk

    2015-08-01

    Full Text Available Ecosystem deterioration in small lowland agricultural rivers that results from river dredging entails a significant threat to the appropriate ecohydrological conditions of these water bodies, expressed as homogenization of habitats and loss of biodiversity. Our study was aimed at a comparison of abundance and taxonomic structure of bottom-dwelling macroinvertebrates in dredged and non-dredged stretches of small lowland rivers and tributaries of the middle Narew River, namely: Czaplinianka, Turośnianka, Dąb, and Ślina. The experimental setup was (1 to collect samples of the bottom material from the river stretches that either persisted in a non-modified state (dredging was not done there in the last few years or had been subjected to river dredging in the year of sampling; and (2 to analyze the abundance and taxonomic structure of macroinvertebrates in the collected samples. The study revealed that at the high level of statistical significance (from p = 0.025 to p = 0.001, the total abundance of riverbed macroinvertebrates in the dredged stretches of the rivers analyzed was approximately 70% lower than in non-dredged areas. We state that the dredging of small rivers in agricultural landscapes seriously affects their ecological status by negatively influencing the concentrations and species richness of benthic macroinvertebrates.

  20. Modeling radiocesium transport from a river catchment based on a physically-based distributed hydrological and sediment erosion model.

    Science.gov (United States)

    Kinouchi, Tsuyoshi; Yoshimura, Kazuya; Omata, Teppei

    2015-01-01

    The accident at the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) in March 2011 resulted in the deposition of large quantities of radionuclides, such as (134)Cs and (137)Cs, over parts of eastern Japan. Since then high levels of radioactive contamination have been detected in large areas, including forests, agricultural land, and residential areas. Due to the strong adsorption capability of radiocesium to soil particles, radiocesium migrates with eroded sediments, follows the surface flow paths, and is delivered to more populated downstream regions and eventually to the Pacific Ocean. It is therefore important to understand the transport of contaminated sediments in the hydrological system and to predict changes in the spatial distribution of radiocesium concentrations by taking the land-surface processes related to sediment migration into consideration. In this study, we developed a distributed model to simulate the transport of water and contaminated sediment in a watershed hydrological system, and applied this model to a partially forested mountain catchment located in an area highly contaminated by the radioactive fallout. Observed discharge, sediment concentration, and cesium concentration measured from June 2011 until December 2012 were used for calibration of model parameters. The simulated discharge and sediment concentration both agreed well with observed values, while the cesium concentration was underestimated in the initial period following the accident. This result suggests that the leaching of radiocesium from the forest canopy, which was not considered in the model, played a significant role in its transport from the catchment. Based on the simulation results, we quantified the long-term fate of radiocesium over the study area and estimated that the effective half-life of (137)Cs deposited in the study area will be approximately 22 y due to the export of contaminated sediment by land-surface processes, and the amount of (137)Cs remaining in the

  1. Inside the "Black Box" of River Restoration: Using Catchment History to Identify Disturbance and Response Mechanisms to Set Targets for Process-Based Restoration

    Directory of Open Access Journals (Sweden)

    Sarah Mika

    2010-12-01

    Full Text Available Many river restoration projects fail. Inadequate project planning underpins many of the reasons given for failure (such as setting overly ambitious goals; selecting inappropriate sites and techniques; losing stakeholder motivation; and neglecting to monitor, assess, and document projects. Another major problem is the lack of an agreed guiding image to direct the activities aimed at restoring the necessary biophysical and ecological processes within the logistic constraints of on-ground works. Despite a rich literature defining the components of restoration project planning, restoration ecology currently lacks an explicit and logical means of moving from the initial project vision through to on-ground strategies. Yet this process is fundamental because it directly links the ecological goals of the project to the on-ground strategies used to achieve them. We present a planning process that explicitly uses an interdisciplinary mechanistic model of disturbance drivers and system responses to build from the initial project vision to the implementation of on-ground works. A worked example on the Upper Hunter River in southeastern Australia shows how understanding catchment history can reveal disturbance and response mechanisms, thus facilitating process-based restoration.

  2. Integrated analysis of the climate change effects on water availability for catchment management. The case of the Ésera River (Spain)

    Science.gov (United States)

    Solera, Abel; Segura, Carlos; Bussi, Gianbattista; Momblanch, Andrea; Francés, Félix

    2014-05-01

    The analysis of the impact of climate change on water resources is of primary importance in Mediterranean Areas. Mean precipitation is expected to decrease, although an increase in its torrentiality is foreseen, and temperature is expected to increase. In addition, growing urban water demand and new environmental requirements also contribute to increase water stress. To achieve an improved use of water resources, new and detailed studies of the impact of the climate change are needed. Due to the high complexity of rainfall-runoff processes and the need to incorporate climate change effect in them, physically based distributed models are proposed as a tool for assessing and analysing the climate change impact on water discharge. In this case, the distributed conceptual TETIS model was employed. This model was previously calibrated and validated in order to reproduce the hydrological cycle of a Mediterranean-influenced catchment, the Ésera River (Spain), under current climate conditions. Then, the TETIS model was driven by the results of a climatic model (precipitation and temperature series) under three climatic scenarios: current climate (or control scenario), A2 and B2 of the Special Report on Emission Scenarios. Water discharge series were generated at different points of the catchment. The model results pointed out that a global decrease in water yield is devised, being around 33% and 37% for scenario A2 and B2 respectively. Water discharge series were subsequently used in the analysis of climate change impact on water resources and water use in the studied river basin. To do so, a water allocation model was built, calibrated and validated under current streamflow conditions for the Ésera River. It considered all the water management infrastructures, water uses and environmental requirements. The results from TETIS for the three different scenarios were introduced as inputs to the water management model, what allowed performing three simulations. The outcomes

  3. Semi-quantitative method for the assessment of debris supply from slopes to river in ungauged catchments.

    Science.gov (United States)

    Tiranti, Davide; Cavalli, Marco; Crema, Stefano; Zerbato, Marina; Graziadei, Maria; Barbero, Secondo; Cremonini, Roberto; Silvestro, Chiara; Bodrato, Giulia; Tresso, Francesco

    2016-06-01

    This paper presents an integrated empirical methodology for assessing the amount of sediment transported from slopes to the main river in absence of a sediment transport monitoring system. The amount of transported sediment is calculated through the characterization of the sediment source areas including the identification of the slope phenomena responsible for the sediment propagation to the main river: shallow landslides, channelized debris flows and deep-seated rotational slides. On this basis, several scenarios related to the climatic conditions are defined: they indicate the number of possible slope phenomena and potential volumes of mobilized unconsolidated material from sediment source areas to the main river. This methodology was finalized and tested in the Maira River basin (south-western Italian Alps) with quite good results.

  4. Attributes for MRB_E2RF1 Catchments by Major Rivers Basins in the Conterminous United States: Total Precipitation, 2002

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This tabular data set represents the catchment-average total precipitation in millimeters multiplied by 100 for 2002, compiled for every MRB_E2RF1 catchment of...

  5. River network bedload model: a tool to investigate the impact of flow regulation on grain size distribution in a large Alpine catchment

    Science.gov (United States)

    Costa, Anna; Molnar, Peter

    2017-04-01

    Sediment transport rates along rivers and the grain size distribution (GSD) of coarse channel bed sediment are the result of the long term balance between transport capacity and sediment supply. Transport capacity, mainly a function of channel geometry and flow competence, can be altered by changes in climatic forcing as well as by human activities. In Alpine rivers it is hydropower production systems that are the main causes of modification to the transport capacity of water courses through flow regulation, leading over longer time scales to the adjustment of river bed GSDs. We developed a river network bedload transport model to evaluate the impacts of hydropower on the transfer of sediments and the GSDs of the Upper Rhône basin, a 5,200 km2 catchment located in the Swiss Alps. Many large reservoirs for hydropower production have been built along the main tributaries of the Rhône River since the 1960s, resulting in a complex system of intakes, tunnels, and pumping stations. Sediment storage behind dams and intakes, is accompanied by altered discharge due to hydropower operations, mainly higher flow in winter and lower in summer. It is expected that this change in flow regime may have resulted in different bedload transport. However, due the non-linear, threshold-based nature of the relation between discharge and sediment mobilization, the effects of changed hydraulic conditions are not easily deducible, and because observations of bedload in pre- and post-dam conditions are usually not available, a modelling approach is often necessary. In our modelling approach, the river network is conceptualized as a series of connected links (river reaches). Average geometric characteristics of each link (width, length, and slope of cross section) are extracted from digital elevation data, while surface roughness coefficients are assigned based on the GSD. Under the assumptions of rectangular prismatic cross sections and normal flow conditions, bed shear stress is estimated

  6. Gully Erosion Mapping and Monitoring at Multiple Scales Based on Multi-Source Remote Sensing Data of the Sancha River Catchment, Northeast China

    Directory of Open Access Journals (Sweden)

    Ranghu Wang

    2016-11-01

    Full Text Available This research is focused on gully erosion mapping and monitoring at multiple spatial scales using multi-source remote sensing data of the Sancha River catchment in Northeast China, where gullies extend over a vast area. A high resolution satellite image (Pleiades 1A, 0.7 m was used to obtain the spatial distribution of the gullies of the overall basin. Image visual interpretation with field verification was employed to map the geometric gully features and evaluate gully erosion as well as the topographic differentiation characteristics. Unmanned Aerial Vehicle (UAV remote sensing data and the 3D photo-reconstruction method were employed for detailed gully mapping at a site scale. The results showed that: (1 the sub-meter image showed a strong ability in the recognition of various gully types and obtained satisfactory results, and the topographic factors of elevation, slope and slope aspects exerted significant influence on the gully spatial distribution at the catchment scale; and (2 at a more detailed site scale, UAV imagery combined with 3D photo-reconstruction provided a Digital Surface Model (DSM and ortho-image at the centimeter level as well as a detailed 3D model. The resulting products revealed the area of agricultural utilization and its shaping by human agricultural activities and water erosion in detail, and also provided the gully volume. The present study indicates that using multi-source remote sensing data, including satellite and UAV imagery simultaneously, results in an effective assessment of gully erosion over multiple spatial scales. The combined approach should be continued to regularly monitor gully erosion to understand the erosion process and its relationship with the environment from a comprehensive perspective.

  7. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: Basin Characteristics, 2002 Geospatial_Data_Presentation_Form: tabular digital data

    Science.gov (United States)

    Wieczorek, Michael; LaMotte, Andrew E.

    2010-01-01

    This tabular data set represents basin characteristics for the year 2002 compiled for every MRB_E2RF1 catchment of selected Major River Basins (MRBs, Crawford and others, 2006). These characteristics are reach catchment shape index, stream density, sinuosity, mean elevation, mean slope and number of road-stream crossings. The source data sets are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) RF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011) and the U.S. Census Bureau's TIGER/Line Files (U.S. Census Bureau,2006). The MRB_E2RF1 catchments are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering New England and Mid-Atlantic (MRB1), South Atlantic-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great basin (MRB6), the Pacific Northwest (MRB7) river basins, and California (MRB8).

  8. Assessment of soil erosion and sediment delivery ratio using remote sensing and GIS: a case study of upstream Chaobaihe River catchment,north China

    Institute of Scientific and Technical Information of China (English)

    Weifeng ZHOU; Bingfang WU

    2008-01-01

    Soil erosion in catchment areas reduces soil productivity and causes a loss of reservoir capacity.Several parametric models have been developed to predict soil erosion at drainage basins,hill slopes and field levels.The well-known Universal Soil Loss Equation (USLE) represents a standardized approach.Miyun reservoir,which sits on Chaobaibe River,is the main surface source of drinking water for Beijing,the capital of China.Water and soil loss are the main reasons for sediment to enter a reservoir.Sediment yield is assessed using a version of the universal soil loss equation modified by Chinese researchers.All year 2001 and 2002 data for factors in the equation are obtained from remote sensing or collected to form an analysis database.These factors are computed and mapped using Geographic Information System tools.Based on the complex database,the modified model is developed.Through pixel-based computing the sediment yield per hydrological unit is calculated.The model does not consider sediment deposition occurring on hillsiopes.Gross soil loss is often higher than the sum of those measured at catchment outlets.The sediment delivery ratio (SDR) per hydrological unit is also computed.This study analyzes the main contributions of sediment yields on sub-basins of the Chaobaihe River to the Miyun Reservoir,and discusses the possible reasons for the difference between SDRs in 2001 and 2002 at different outlets.The result shows that in the upper basin of the Miyun Reservoir,in 2001 the area of erosion that could be neglected was 8,202.76 km2,the area of low erosion 3,269.59 km2,the area of moderate erosion 3,400.97 km2,the area of high erosion 436.89 km2,the area of strong erosion 52.19 km2 and the area of severe erosion 3.13 km2.The highest soil loss was 70,353 t/km2,yr in Fengning County in 2001,followed by 64,418 t/km2,yr by Chicheng County in 2001.The SDR in 2002 was lower than that in 2001.The main reasons are the decreasing rainfall erosivity and total runoff.

  9. Farmer and retailer knowledge and awareness of the risks from pesticide use: A case study in the Wei River catchment, China

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Xiaomei, E-mail: xiaomei.yang@wur.nl [Soil Physics and Land Management, Wageningen University, P.O. Box 47, 6700AA Wageningen (Netherlands); State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, 712100 Yangling (China); Wang, Fei [State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, 712100 Yangling (China); Institute of Soil and Water Conservation, Northwest A and F University, 712100 Yangling (China); Meng, Lei [Baoji University of Arts and Sciences, 712300 Baoji, Shaanxi (China); Zhang, Wenshuai [State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, 712100 Yangling (China); Fan, Liangxin [School of Surveying and Land Information Engineering, Henan Polytechnic University, 454003 Jiaozuo, Henan Province (China); Geissen, Violette [Soil Physics and Land Management, Wageningen University, P.O. Box 47, 6700AA Wageningen (Netherlands); Institute of Crop Science and Resources Conservation (INRES), University of Bonn, 53115 Bonn (Germany); Ritsema, Coen J. [Soil Physics and Land Management, Wageningen University, P.O. Box 47, 6700AA Wageningen (Netherlands)

    2014-11-01

    Monitoring the educational level of farmers and retailers on pesticide use would be useful to assess the appropriateness of information for reducing or/and avoiding the risks from pesticides in rural regions. The levels of knowledge and awareness of the dangers to the environment and human health were investigated by questionnaires for farmers (209) and retailers (20) in two rural regions (Qianyang County (S1) and Chencang County (S2)) of the Wei River catchment in China where the modes of farming and the state of erosion are very different. The results showed that farmers learned the use and dangers of pesticides mainly by oral communication (p < 0.01). Protective measures were inadequate; 65% (S1) and 55% (S2) of farmers never used any protective measures during spraying (p < 0.05). Washing hands (> 70%) was the most common mode of personal hygiene, relative to wearing masks, showering, and changing clothes, but no significant differences were observed between the selected regions. Most pesticide wastes were dumped directly onto the land or into water, suggesting that educational measures should be taken to address the potential risks from the residues in the wastes. Over 85% of farmers (S1 and S2) claimed to use illegal pesticides, but the reasons for their use varied (p < 0.01). Retailers were well-informed and highly conscious of their responsibility for the safe use of pesticides, especially in S2 (p < 0.01). A canonical correspondence analysis indicated that educational level and age differed between the two regions and contributed greatly to the risks from pesticide use (p < 0.01). Educational programmes targeted to age groups, proper disposal of pesticide waste, and sufficient supervision from authorities should consequently be considered for improving the levels of knowledge and awareness of the dangers of pesticides to human health and environmental pollution in the Wei River catchment, China. - Highlights: • The status of income and expenditure on

  10. BasinBox: a generic multimedia fate model for predicting the fate of chemicals in river catchments

    NARCIS (Netherlands)

    Hollander, A; Huijbregts, M A J; Ragas, A M J; Meent, D van de

    2006-01-01

    Multimedia fate models have proven to be very useful tools in chemical risk assessment and management. This paper presents BasinBox, a newly developed steady-state generic multimedia fate model for evaluating risks of new and existing chemicals in river basins. The model concepts, as well as the int

  11. Contrasting climate change impact on river flows from high-altitude catchments in the Himalayan and Andes Mountains

    NARCIS (Netherlands)

    Ragettli, Silvan; Immerzeel, Walter W.; Pellicciotti, Francesca

    2016-01-01

    Mountain ranges are the world's natural water towers and provide water resources for millions of people. However, their hydrological balance and possible future changes in river flow remain poorly understood because of high meteorological variability, physical inaccessibility, and the complex interp

  12. Hydrobiological studies in the catchment of Vaal dam, South Africa. Part 1. River Zonation and the Benthic Fauna

    CSIR Research Space (South Africa)

    Chutter, FM

    1970-01-01

    Full Text Available Vaal Dam is situated on the elevated plateau which forms the interior of South Africa and is a little less than 1500 m above the level. The source of the most of the streams and rivers flowing into the dam are about 2000 m above sea level, though...

  13. Long Term Quantification of Climate and Land Cover Change Impacts on Streamflow in an Alpine River Catchment, Northwestern China

    Directory of Open Access Journals (Sweden)

    Zhenliang Yin

    2017-07-01

    Full Text Available Quantifying the long term impacts of climate and land cover change on streamflow is of great important for sustainable water resources management in inland river basins. The Soil and Water Assessment Tool (SWAT model was employed to simulate the streamflow in the upper reaches of Heihe River Basin, northwestern China, over the last half century. The Sequential Uncertainty Fitting algorithm (SUFI-2 was selected to calibrate and validate the SWAT model. The results showed that both Nash-Sutcliffe efficiency (NSE and determination coefficient (R2 were over 0.93 for calibration and validation periods, the percent bias (PBIAS of the two periods were—3.47% and 1.81%, respectively. The precipitation, average, maximum, and minimum air temperature were all showing increasing trends, with 14.87 mm/10 years, 0.30 °C/10 years, 0.27 °C/10 year, and 0.37 °C/10 years, respectively. Runoff coefficient has increased from 0.36 (averaged during 1964 to 1988 to 0.39 (averaged during 1989 to 2013. Based on the SWAT simulation, we quantified the contribution of climate and land cover change to streamflow change, indicated that the land cover change had a positive impact on river discharge by increasing 7.12% of the streamflow during 1964 to 1988, and climate change contributed 14.08% for the streamflow increasing over last 50 years. Meanwhile, the climate change impact was intensive after 2000s. The increasing of streamflow contributed to the increasing of total streamflow by 64.1% for cold season (November to following March and 35.9% for warm season (April to October. The results provide some references for dealing with climate and land cover change in an inland river basin for water resource management and planning.

  14. Contrasting climate change impact on river flows from high altitude catchments in the Himalayan and Andes Mountains

    OpenAIRE

    Ragettli, Silvan; Immerzeel, Walter; Pellicciotti, Francesca

    2016-01-01

    Mountain ranges are world’s natural water towers and provide water resources for millions of people. Yet, their hydrological balance and possible future changes in river flow remain poorly understood because of high meteorological variability, physical inaccessibility and the complex interplay between climate, cryosphere and hydrological processes. Here we use a state-of-the art glacio-hydrological model informed by data from high altitude observations and CMIP5 climate change scenarios to qu...

  15. Assessment of contamination and origin of metals in mining affected river sediments: A case study of the Aries catchment, Romania

    Directory of Open Access Journals (Sweden)

    Levei Erika

    2014-01-01

    Full Text Available The study presents the current status of contamination with metals (Cu, Cr, Cd, Pb, Ni, Zn, As and their anthropogenic or natural origin in the sediments of the Aries river basin, Romania, affected by mining activities. The results indicated an enrichment of metals in sediments. Different contamination levels were identified on the Aries river and its tributaries. According to sediment quality guidelines and contamination indices, sediments from the Aries river were found to be highly contaminated with Cd, Cu, As, considerably with Zn and moderately with Pb and Ni. The right-bank tributaries were found to be more contaminated than the left-bank affluents, where only a contamination with As of geogenic origin was identified. The Principal Component Analysis allowed to identify five latent factors (86 % total variability reflecting the anthropogenic and natural origins of metals. Arsenic, Cd and partially Pb were found to have a common anthropogenic origin, different from that of Cu. The statistical approach indicated also the geogenic origin of Pb due to its association with Ca, K, Na, Sr. Chromium and Ni were attributed to natural source following their association with Mn, Fe, Al and Mg, respectively.

  16. IDENTIFICATION OF DANGER ZONES FOR SURFACE WATER USING GIS (SIP – MAPINFO SYSTEM ON AN EXAMPLE OF UPPER NAREW RIVER CATCHMENT

    Directory of Open Access Journals (Sweden)

    Mirosław Skorbiłowicz

    2016-07-01

    Full Text Available Creating the buffer zones is a function intended to designate an area in particular, of a constant distance around the spatial objects. The aim of the study was to create maps as thematic layers, which served to identify areas of existing and potential contamination of surface water and other environmental elements. Among others, it made possible to localize the areas potentially affected by the surface water pollution due to transport; localize the areas potentially affected by the surface water pollution due to the discharge of sewage from human settlements; localize the zones with mitigated impact of communication emissions due to the natural protection of forests taking the form of so-called geochemical barriers. The spatial analyzes allowed to generate model-zones of the existing and potential threat of water pollution in the Narew river catchment. Designated danger zones can be verified by studies as well as they can be very helpful in determining the monitoring network and for water quality modeling process.

  17. The Achievement of a Decentralized Water Management Through Stakeholder Participation: An Example from the Drôme River Catchment Area in France (1981-2008)

    Science.gov (United States)

    Comby, Emeline; Le Lay, Yves-François; Piégay, Hervé

    2014-11-01

    Different water Acts (e.g., the European Water Framework Directive) and stakeholders involved in aquatic affairs have promoted integrated river basin management over recent decades. However, few studies have provided feedback on these policies. The aim of the current article is to fill this gap by exploring how local newspapers reflect the implementation of a broad public participation within a catchment of France known for its innovation with regard to this domain. The media coverage of a water management strategy in the Drôme watershed from 1981 to 2008 was investigated using a content analysis and a geographic information system. We sought to determine what public participation and decentralized decision-making can be in practice. The results showed that this policy was integrated because of its social perspective, the high number of involved stakeholders, the willingness to handle water issues, and the local scale suitable for participation. We emphasized the prominence of the watershed scale guaranteed by the local water authority. This area was also characterized by compromise, arrangements, and power dynamics on a fine scale. We examined the most politically engaged writings regarding water management, which topics of each group emphasized, and how the groups agreed and disagreed on issues based on their values and context. The temporal pattern of participation implementation was progressive but worked by fits and starts.

  18. Chemical and physiological metal bioaccessibility assessment in surface bottom sediments from the Deba River urban catchment: Harmonization of PBET, TCLP and BCR sequential extraction methods.

    Science.gov (United States)

    Unda-Calvo, Jessica; Martínez-Santos, Miren; Ruiz-Romera, Estilita

    2017-04-01

    In the present study, the physiologically based extraction test PBET (gastric and intestinal phases) and two chemical based extraction methods, the toxicity characteristic leaching procedure (TCLP) and the sequential extraction procedure BCR 701 (Community Bureau of Reference of the European Commission) have been used to estimate and evaluate the bioaccessibility of metals (Fe, Mn, Zn, Cu, Ni, Cr and Pb) in sediments from the Deba River urban catchment. The statistical analysis of data and comparison among physiological and chemical methods have highlighted the relevance of simulate the gastrointestinal tract environment since metal bioaccessibility seems to depend on water and sediment properties such as pH, redox potential and organic matter content, and, primordially, on the form in which metals are present in the sediment. Indeed, metals distributed among all fractions (Mn, Ni, Zn) were the most bioaccessible, followed by those predominantly bound to oxidizable fraction (Cu, Cr and Pb), especially near major urban areas. Finally, a toxicological risk assessment was also performed by determining the hazard quotient (HQ), which demonstrated that, although sediments from mid- and downstream sampling points presented the highest metal bioaccessibilities, were not enough to have adverse effects on human health, Cr being the most potentially toxic element. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. The heron that laid the golden egg: metals and metalloids in ibis, darter, cormorant, heron, and egret eggs from the Vaal River catchment, South Africa.

    Science.gov (United States)

    van der Schyff, V; Pieters, R; Bouwman, H

    2016-06-01

    Metal pollution issues are afforded the highest priority in developing countries. Only one previous study has addressed metals in African bird eggs. We determined the concentration of metals and metalloids in bird eggs from four sites in the Vaal River catchment (VRC) of South Africa to provide data on the current situation. We analysed 16 pools of 77 heron, ibis, darter, egret, and cormorant eggs for 18 metals and metalloids using ICP-MS. We found high concentrations of gold (Au), uranium (U), thallium (Tl), and platinum (Pt) in Grey Heron eggs from Baberspan. Great white egrets from Bloemhof Dam had high concentrations of mercury (Hg). Multivariate analyses revealed strong associations between Au and U, and between palladium (Pd) and Pt. The toxic reference value (TRV) for Hg was exceeded in seven pools. Selenium exceeded its TRV in one pool; in the same pool, copper (Cu) reached its TRV. Compared with other studies, VRC bird eggs had high concentrations of contaminants. Based on these high concentrations, human health might be at risk as Grey Herons and humans share similar food and are therefore exposed to the same contaminants.

  20. Occurrence and diversity of Arcobacter spp. along the Llobregat River catchment, at sewage effluents and in a drinking water treatment plant.

    Science.gov (United States)

    Collado, Luis; Kasimir, Georg; Perez, Unai; Bosch, Albert; Pinto, Rosa; Saucedo, Gemma; Huguet, Josep M; Figueras, Maria Jose

    2010-06-01

    The presence of Arcobacter species in faecally contaminated environmental waters has previously been studied. However, the ability to eliminate Arcobacter during the water treatment processes that produce drinking water has been little studied. We have investigated the prevalence and diversity of Arcobacter spp. throughout the year at 12 sampling points in the Llobregat River catchment (Catalonia, Spain) including 3 sites at a drinking water treatment plant. Positive samples for Arcobacter spp., came predominantly from the most faecally polluted sites. Recovery rates from all sites were greater in the spring (91.7%) and summer (83.3%) than in autumn and winter (75.0% in both cases), but this trend was not statistically evaluated due to the limited number of samples. Among the 339 colonies analyzed, the most prevalent species by multiplex PCR and 16S rDNA restriction fragment length polymorphism were Arcobacter butzleri (80.2%), followed by Arcobacter cryaerophilus (19.4%) and Arcobacter skirrowii (0.3%). Isolates showed a high genotype diversity as determined by the enterobacterial repetitive intergenic consensus PCR. In fact, 91.2% (309/339) of the colonies had different genotypes, i.e. 248 of them among the 275 isolates of A. butzleri and 60 among the 63 isolates of A. cryaerophilus and 1 genotype of A. skirrowii. Arcobacter was never detected or isolated from finished drinking water, demonstrating that water treatment is effective in removing Arcobacter species.

  1. Restoring the Mississippi River Basin from the Catchment to the Coast Defines Science and Policy Issues of Ecosystem Services Associated with Alluvial and Coastal Deltaic Floodplains: Soil Conservation, Nutrient Reduction, Carbon Sequestration, and Flood Control

    Science.gov (United States)

    Twilley, R.

    2014-12-01

    Large river systems are major economic engines that provide national economic wealth in transporting commerce and providing extensive agriculture production, and their coastal deltas are sites of significant ports, energy resources and fisheries. These coupled natural and social systems from the catchment to the coast depend on how national policies manage the river basins that they depend. The fundamental principle of the Mississippi River Basin, as in all basins, is to capitalize on the ability of fertile soil that moves from erosional regions of a large watershed, through downstream regions of the catchment where sediment transport and storage builds extensive floodplains, to the coastal region of deposition where deltas capture sediment and nutrients before exported to the oceans. The fate of soil, and the ability of that soil to do work, supports the goods and services along its path from the catchment to the coast in all large river basin and delta systems. Sediment is the commodity of all large river basin systems that together with the seasonal pulse of floods across the interior of continents provide access to the sea forming the assets that civilization and economic engines have tapped to build national and global wealth. Coastal landscapes represent some of the most altered ecosystems worldwide and often integrate the effects of processes over their entire catchment, requiring systemic solutions to achieve restoration goals from alluvial floodplains upstream to coastal deltaic floodplains downstream. The urgent need for wetland rehabilitation at landscape scales has been initiated through major floodplain reclamation and hydrologic diversions to reconnect the river with wetland processes. But the constraints of sediment delivery and nutrient enrichment represent some critical conflicts in earth surface processes that limit the ability to design 'self sustaining' public work projects; particularly with the challenges of accelerated sea level rise. Only

  2. Future efficiency of run of the river hydropower schemes based on climate change scenarios: case study in UK catchments

    Science.gov (United States)

    Pasten Zapata, Ernesto; Moggridge, Helen; Jones, Julie; Widmann, Martin

    2017-04-01

    Run-of-the-River (ROR) hydropower schemes are expected to be importantly affected by climate change as they rely in the availability of river flow to generate energy. As temperature and precipitation are expected to vary in the future, the hydrological cycle will also undergo changes. Therefore, climate models based on complex physical atmospheric interactions have been developed to simulate future climate scenarios considering the atmosphere's greenhouse gas concentrations. These scenarios are classified according to the Representative Concentration Pathways (RCP) that are generated according to the concentration of greenhouse gases. This study evaluates possible scenarios for selected ROR hydropower schemes within the UK, considering three different RCPs: 2.6, 4.5 and 8.5 W/m2 for 2100 relative to pre-industrial values. The study sites cover different climate, land cover, topographic and hydropower scheme characteristics representative of the UK's heterogeneity. Precipitation and temperature outputs from state-of-the-art Regional Climate Models (RCMs) from the Euro-CORDEX project are used as input for a HEC-HMS hydrological model to simulate the future river flow available. Both uncorrected and bias-corrected RCM simulations are analyzed. The results of this project provide an insight of the possible effects of climate change towards the generation of power from the ROR hydropower schemes according to the different RCP scenarios and contrasts the results obtained from uncorrected and bias-corrected RCMs. This analysis can aid on the adaptation to climate change as well as the planning of future ROR schemes in the region.

  3. REACH-ER: a tool to evaluate river basin remediation measures for contaminants at the catchment scale

    Science.gov (United States)

    van Griensven, Ann; Haest, Pieter Jan; Broekx, Steven; Seuntjens, Piet; Campling, Paul; Ducos, Geraldine; Blaha, Ludek; Slobodnik, Jaroslav

    2010-05-01

    The European Union (EU) adopted the Water Framework Directive (WFD) in 2000 ensuring that all aquatic ecosystems meet ‘good status' by 2015. However, it is a major challenge for river basin managers to meet this requirement in river basins with a high population density as well as intensive agricultural and industrial activities. The EU financed AQUAREHAB project (FP7) specifically examines the ecological and economic impact of innovative rehabilitation technologies for multi-pressured degraded water bodies. For this purpose, a generic collaborative management tool ‘REACH-ER' is being developed that can be used by stakeholders, citizens and water managers to evaluate the ecological and economical effects of different remedial actions on waterbodies. The tool is built using databases from large scale models simulating the hydrological dynamics of the river basing and sub-basins, the costs of the measures and the effectiveness of the measures in terms of ecological impact. Knowledge rules are used to describe the relationships between these data in order to compute the flux concentrations or to compute the effectiveness of measures. The management tool specifically addresses nitrate pollution and pollution by organic micropollutants. Detailed models are also used to predict the effectiveness of site remedial technologies using readily available global data. Rules describing ecological impacts are derived from ecotoxicological data for (mixtures of) specific contaminants (msPAF) and ecological indices relating effects to the presence of certain contaminants. Rules describing the cost-effectiveness of measures are derived from linear programming models identifying the least-cost combination of abatement measures to satisfy multi-pollutant reduction targets and from multi-criteria analysis.

  4. Long term continuous field survey to assess nutrient emission impact from irrigated paddy field into river catchment

    Science.gov (United States)

    Kogure, Kanami; Aichi, Masaatsu; Zessner, Matthias

    2017-04-01

    In order to achieve good river environment, it is very important to understand and to control nutrient behavior such as Nitrogen and Phosphorus. As we could reduce impact from urban and industrial activities by wastewater treatment, pollution from point sources are likely to be controlled. Besides them, nutrient emission from agricultural activity is dominant pollution source into the river system. In many countries in Asia and Africa, rice is widely cultivated and paddy field covers large areas. In Japan 54% of its arable land is occupied with irrigated paddy field. While paddy field can deteriorate river water quality due to fertilization, it is also suggested that paddy field can purify water. We carried out field survey in middle reach of the Tone River Basin with focus on a paddy field IM. The objectives of the research are 1) understanding of water and nutrient balance in paddy field, 2) data collection for assessing nutrient emission. Field survey was conducted from June 2015 to October 2016 covering two flooding seasons in summer. In our measurement, all input and output were measured regarding water, N and P to quantify water and nutrient balance in the paddy field. By measuring water quality and flow rate of inflow, outflow, infiltrating water, ground water and flooding water, we tried to quantitatively understand water, N and P cycle in a paddy field including seasonal trends, and changes accompanied with rainy events and agricultural activities like fertilization. Concerning water balance, infiltration rate was estimated by following equation. Infiltration=Irrigation water + Precipitation - Evapotranspiration -Outflow We estimated mean daily water balance during flooding season. Infiltration is 11.9mm/day in our estimation for summer in 2015. Daily water reduction depth (WRD) is sum of Evapotranspiration and Infiltration. WRD is 21.5mm/day in IM and agrees with average value in previous research. Regarding nutrient balance, we estimated an annual N and

  5. Dual 10Be isotope systems constrain the source of sediment and rate of erosion for the tropical Barron River catchment, Queensland, Australia

    Science.gov (United States)

    Nichols, K. K.; Bierman, P. R.; Reusser, L. J.; Portenga, E.; Matmon, A.; Rood, D. H.

    2010-12-01

    In order to understand source of sediment and rate of erosion for Barron River catchment, which heads on the Atherton Tablelands of northeast Australia, crosses the northern Queensland escarpment and drains into the Coral Sea, we collected fluvial sediment and measured both in situ and meteoric 10Be contents on the medium sand fraction. We collected fourteen samples from rivers and streams including large regional drainages and small tributaries. The upland basins are characterized by lower relief and less precipitation than the steeper and wetter escarpment basins. One sample is quartz sand from the Coral Sea beach at Yorkey's Knob, below the escarpment. Sand from the Barron River upstream of the escarpment integrates the upland basins and has an in situ 10Be concentration of 2.31±0.84 x105atoms/g and an erosion rate of 17.2 m/My (calculated using the CRONOS on-line calculator). This is similar to a major upland tributary (2.51±0.40 x105 atoms/g; 15.2 m/My) and two smaller upstream tributaries (20.5 m/My and 21.4 m/My). Escarpment streams have less in situ 10Be in their sediment (mean = 1.64±0.55 x 105 atoms/g, n=8) and higher basin area-weighted erosion rates (37.2 m/My). Based on the in situ measurements, the uplands are eroding at approximately half the rate of the escarpment basins. The beach sand has an in situ 10Be concentration (2.75±0.19 x 105 atoms/g) similar to the upland sediment suggesting that the source of beach sand is the larger but more slowly eroding Tablelands. In contrast, the meteoric 10Be concentrations of Barron River sand-sized sediment collected above the escarpment is ~4 fold lower (2.55x107 atoms/g) than the average meteoric 10Be concentration of the 8 escarpment samples (9.94±4.49 x107 atoms/g). This discrepancy cannot be explained by differences in annual average precipitation which ranges only from 1.9 to 2.3 m/yr but likely results from the deep mobility of meteoric 10Be in oxic Tableland soils. Considering meteoric 10Be as a

  6. Modelling the impact of prescribed global warming on runoff from headwater catchments of the Irrawaddy River and their implications for the water level regime of Loktak Lake, northeast India

    Directory of Open Access Journals (Sweden)

    C. R. Singh

    2010-09-01

    Full Text Available Climate change is likely to have major implications for wetland ecosystems, which will include altered water level regimes due to modifications in local and catchment hydrology. However, substantial uncertainty exists in the precise impacts of climate change on wetlands due in part to uncertainty in GCM projections. This paper explores the impacts of climate change upon river discharge within three sub-catchments of Loktak Lake, an internationally important wetland in northeast India. This is achieved by running pattern-scaled GCM output through distributed hydrological models (developed using MIKE SHE of each sub-catchment. The impacts of climate change upon water levels within Loktak Lake are subsequently investigated using a water balance model. Two groups of climate change scenarios are investigated. Group 1 uses results from seven different GCMs for an increase in global mean temperature of 2 °C, the purported threshold of ''dangerous'' climate change, whilst Group 2 is based on results from the HadCM3 GCM for increases in global mean temperature between 1 °C and 6 °C. Results from the Group 1 scenarios show varying responses between the three sub-catchments. The majority of scenario-sub-catchment combinations (13 out of 21 indicate increases in discharge which vary from <1% to 42% although, in some cases, discharge decreases by as much as 20%. Six of the GCMs suggest overall increases in river flow to Loktak Lake (2–27% whilst the other results in a modest (6% decline. In contrast, the Group 2 scenarios lead to an almost linear increase in total river flow to Loktak Lake with increasing temperature (up to 27% for 6 °C, although two sub-catchments experience reductions in mean discharge for the smallest temperature increases. In all but one Group 1 scenario, and all the Group 2 scenarios, Loktak Lake water levels are higher, regularly reaching the top of a downstream hydropower barrage that impounds the lake and necessitating the

  7. Spatiotemporal Variation and Risk Assessment of Pesticides in Water of the Lower Catchment Basin of Acheloos River, Western Greece

    Directory of Open Access Journals (Sweden)

    Nikolaos Stamatis

    2013-01-01

    Full Text Available A three-year monitoring survey (March 2005–February 2008 was conducted to investigate, on monthly basis, the presence of thirty pesticides belonging to various categories and metabolites, in Acheloos River (Western Greece, one of the most important water resources in Greece. Six sampling stations along the river were established. Water analyses were performed using solid-phase extraction combined with gas chromatography with flame thermionic detector and mass spectrometry. Statistical analysis using one-way ANOVA and Duncan’s multiple range test (P<0.05 was used to compare annual mean concentrations of pesticides, seasonal and spatial distribution. In general, the highest mean concentrations of the pesticides were recorded at the three stations downstream. The greatest average concentrations were determined during spring and summer in agreement with the pesticide application period. The observed lower concentrations after 2006 reflect the land-use change because of the elimination of tobacco, the main cultivation of the area for many decades. The compounds most frequently detected were diazinon (78.6%, DEA (69.3%, and fenthion (52.6%. Environmental risk assessment using risk quotient (RQ approach showed high risk for six insecticides in 2005 and one in 2007. A compliance with the European Environmental Quality Standards (EQS was observed for the priority pesticides.

  8. Spatiotemporal variation and risk assessment of pesticides in water of the lower catchment basin of Acheloos River, Western Greece.

    Science.gov (United States)

    Stamatis, Nikolaos; Hela, Dimitra; Triantafyllidis, Vassilios; Konstantinou, Ioannis

    2013-01-01

    A three-year monitoring survey (March 2005-February 2008) was conducted to investigate, on monthly basis, the presence of thirty pesticides belonging to various categories and metabolites, in Acheloos River (Western Greece), one of the most important water resources in Greece. Six sampling stations along the river were established. Water analyses were performed using solid-phase extraction combined with gas chromatography with flame thermionic detector and mass spectrometry. Statistical analysis using one-way ANOVA and Duncan's multiple range test (P mean concentrations of pesticides, seasonal and spatial distribution. In general, the highest mean concentrations of the pesticides were recorded at the three stations downstream. The greatest average concentrations were determined during spring and summer in agreement with the pesticide application period. The observed lower concentrations after 2006 reflect the land-use change because of the elimination of tobacco, the main cultivation of the area for many decades. The compounds most frequently detected were diazinon (78.6%), DEA (69.3%), and fenthion (52.6%). Environmental risk assessment using risk quotient (RQ) approach showed high risk for six insecticides in 2005 and one in 2007. A compliance with the European Environmental Quality Standards (EQS) was observed for the priority pesticides.

  9. The environmental and geomorphological impacts of historical gold mining in the Ohinemuri and Waihou river catchments, Coromandel, New Zealand

    Science.gov (United States)

    Clement, Alastair J. H.; Nováková, Tereza; Hudson-Edwards, Karen A.; Fuller, Ian C.; Macklin, Mark G.; Fox, Elizabeth G.; Zapico, Ignacio

    2017-10-01

    Between 1875 and 1955 approximately 250,000 Mg yr- 1 of mercury-, arsenic-, and cyanide-contaminated mine tailings were discharged directly into the Ohinemuri River and its tributaries, in the Coromandel Region, North Island, New Zealand. A devastating flood on 14 January 1907 deposited large amounts of mine waste across the floodplain of the Ohinemuri and Waihou rivers in the vicinity of the township of Paeroa. The 1907 mine-waste flood deposit was located as a dirty yellow silt in cores and floodplain profiles, with a thickness ranging from 0.15-0.50 m. Geochemical analysis of the mine waste shows elevated concentrations of Pb ( 200-570 mg kg- 1) and As ( 30-80 mg kg- 1), compared to early Holocene background concentrations (Pb environmental event. The mine-waste material remains in the floodplain today, representing a sizable legacy store of contaminant metals and metalloids that pose a long-term risk to the Ohinemuri and Waihou ecosystems.

  10. THE STUDY OF HEAVY METALS CONTENT IN THE CATCHMENT AREA OF THE BIEBRZA RIVER AND THREE TRIBUTARIES

    Directory of Open Access Journals (Sweden)

    Zuzanna Kazimierowicz

    2014-11-01

    Full Text Available Sediment samples were taken in 11 measuring points of the Biebrza River and determined the contents of six metals (Cu, Cr, Co, Ni, Cd and Zn. Arithmetic mean, median and standard deviation were calculated. The sources of heavy metals in bottom sediments are: pollutants of fieldsand meadows (admixtures of plant protection products and fertilizers, discharges of domestic sewage and municipal from local wastewater treatment plants, wastewater di-scharges from rural buildings and pollutions of anthropogenic origin. Research of pollution of bottom sediments with heavy metals are needed tool for monitoring the aquatic environ-ment. Continuous monitoring metal content of the sediments will counteract the effects of the threat of biological life in the water reservoir, which may occur in the case of notorious exceeded permissible content of harmful substances.

  11. Establishing the Ecological Status of Mining-Impacted Freshwaters from Abrud River Catchment Area Using Benthic Diatom Communities (Ros, ia MontanÄă, Romania)

    Science.gov (United States)

    Olenici, Adriana; Baciu, Calin; Momeu, Laura; Cozma, Alexandra; Brahaita, Dorian; Pop, Cristian; Lazar, Laura; Popita, Gabriela; Teodosiu, Gabriela

    2015-04-01

    Keywords: diatom communities, indicator species, mine waters, water quality, Romania. Diatoms are a very distinct group of algae, identifiable under the light microscope by their yellow - brown coloration and by the presence of a thick silica cell wall. The potential for freshwater organisms to reflect changes in environmental conditions was first noted by Kolenati (1848) and Cohn (1853), who observed that biota in polluted waters were different from those in non-polluted situations. Diatoms are widely used to monitor river pollution because they are sensitive to water chemistry, especially to ionic content, pH, dissolved organic matter and nutrients. Wide geographic distribution and well-studied ecology of most diatom species are mentioned as major advantages of using diatoms as indicator organisms. At the same time water quality has begun to deteriorate increasingly, mainly as a result of the physical, chemical and bacteriological alterations, and the aquatic ecosystems are evermore affected by various types of pollution, the anthropic one being almost always included. A good example is Abrud River and its main tributaries (Roșia Montană and surrounding areas, Romania), which has suffered along the years because of the mining waters discharge. In this context, this study presents data on benthic diatom communities from the Abrud River catchment area. Sixteen sites have been sampled seasonal and the best represented diatom genera were Navicula, Nitzschia, Cymbella, Gomphonema, Achnantes, Surirella and Fragilaria. Qualitatively, the number of diatom species exhibited significant variation among sampling sites, also suggesting seasonal dynamics. For instance, in some sampling sites, algal assemblages were absent, as diatom communities were strongly affected by acid mine waters, released from old mining works and waste rocks depots. Some dominant taxa have been observed as well, suggesting critical saprobic levels of the Abrud River and some of its tributaries. The

  12. A practical demonstration in modelling diclofenac and propranolol river water concentrations using a GIS hydrology model in a rural UK catchment

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, A.C. [Centre for Ecology and Hydrology (CEH) Wallingford, Benson Lane, Wallingford, Oxfordshire OX10 8BB (United Kingdom)]. E-mail: ajo@ceh.ac.uk; Keller, V. [Centre for Ecology and Hydrology (CEH) Wallingford, Benson Lane, Wallingford, Oxfordshire OX10 8BB (United Kingdom); Williams, R.J. [Centre for Ecology and Hydrology (CEH) Wallingford, Benson Lane, Wallingford, Oxfordshire OX10 8BB (United Kingdom); Young, A. [Centre for Ecology and Hydrology (CEH) Wallingford, Benson Lane, Wallingford, Oxfordshire OX10 8BB (United Kingdom)

    2007-03-15

    An existing GIS hydrology water quality model, LF2000-WQX, was applied to predict the concentrations of the pharmaceuticals diclofenac and propranalol in catchments. As a practical exercise the predominantly rural Tamar (UK) catchment was chosen. Consumption, excretion, and fate data were used to estimate the pharmaceutical input load for the model. The predicted concentrations throughout most of the catchment were 1 ng/L or less under low flow (90th percentile) conditions. However, at a few locations, downstream of small sewage treatment plants, concentrations above 25 ng/L were predicted. This exercise shows that it is relatively straightforward to predict the concentrations of new and emerging organic microcontaminants in real catchments using existing GIS hydrology water quality models. Further testing will be required to establish their accuracy. - A GIS hydrology model was used to predict pharmaceutical concentration hot spots in a rural catchment.

  13. The catchment based approach using catchment system engineering

    Science.gov (United States)

    Jonczyk, Jennine; Quinn, Paul; Barber, Nicholas; Wilkinson, Mark

    2015-04-01

    The catchment based approach (CaBa) has been championed as a potential mechanism for delivery of environmental directives such as the Water Framework Directive in the UK. However, since its launch in 2013, there has been only limited progress towards achieving sustainable, holistic management, with only a few of examples of good practice ( e.g. from the Tyne Rivers trust). Common issues with developing catchment plans over a national scale include limited data and resources to identify issues and source of those issues, how to systematically identify suitable locations for measures or suites of measures that will have the biggest downstream impact and how to overcome barriers for implementing solutions. Catchment System Engineering (CSE) is an interventionist approach to altering the catchment scale runoff regime through the manipulation of hydrological flow pathways throughout the catchment. A significant component of the runoff generation can be managed by targeting hydrological flow pathways at source, such as overland flow, field drain and ditch function, greatly reducing erosive soil losses. Coupled with management of farm nutrients at source, many runoff attenuation features or measures can be co-located to achieve benefits for water quality and biodiversity. A catchment, community-led mitigation measures plan using the CSE approach will be presented from a catchment in Northumberland, Northern England that demonstrate a generic framework for identification of multi-purpose features that slow, store and filter runoff at strategic locations in the landscape. Measures include within-field barriers, edge of field traps and within-ditch measures. Progress on the implementation of measures will be reported alongside potential impacts on the runoff regime at both local and catchment scale and costs.

  14. Modelling the impact of prescribed global warming on runoff from headwater catchments of the Irrawaddy River and their implications for the water level regime of Loktak Lake, northeast India

    Science.gov (United States)

    Singh, C. R.; Thompson, J. R.; French, J. R.; Kingston, D. G.; Mackay, A. W.

    2010-09-01

    Climate change is likely to have major implications for wetland ecosystems, which will include altered water level regimes due to modifications in local and catchment hydrology. However, substantial uncertainty exists in the precise impacts of climate change on wetlands due in part to uncertainty in GCM projections. This paper explores the impacts of climate change upon river discharge within three sub-catchments of Loktak Lake, an internationally important wetland in northeast India. This is achieved by running pattern-scaled GCM output through distributed hydrological models (developed using MIKE SHE) of each sub-catchment. The impacts of climate change upon water levels within Loktak Lake are subsequently investigated using a water balance model. Two groups of climate change scenarios are investigated. Group 1 uses results from seven different GCMs for an increase in global mean temperature of 2 °C, the purported threshold of ''dangerous'' climate change, whilst Group 2 is based on results from the HadCM3 GCM for increases in global mean temperature between 1 °C and 6 °C. Results from the Group 1 scenarios show varying responses between the three sub-catchments. The majority of scenario-sub-catchment combinations (13 out of 21) indicate increases in discharge which vary from hydropower barrage that impounds the lake and necessitating the release of water for barrage structural stability. Although elevated water levels may permit enhanced abstraction for irrigation and domestic uses, future increases in hydropower generation are limited by existing infrastructure. The higher water levels are likely to exacerbate existing ecological deterioration within the lake as well as enhancing problems of flooding of lakeside communities.

  15. Rainfall and runoff regime trends in mountain catchments (Case study area: the upper Hron River basin, Slovakia

    Directory of Open Access Journals (Sweden)

    Blahušiaková Andrea

    2015-09-01

    Full Text Available This paper presents an analysis of trends and causes of changes of selected hydroclimatic variables influencing the runoff regime in the upper Hron River basin (Slovakia. Different methods for identifying trends in data series are evaluated and include: simple mass curve analysis, linear regression, frequency analysis of flood events, use of the Indicators of Hydrological Alteration software, and the Mann-Kendall test. Analyses are performed for data from two periods (1931-2010 and 1961-2010. The changes in runoff are significant, especially in terms of lower QMax and 75 percentile values. This fact is also confirmed by the lower frequency and extremity of flood events. The 1980s are considered a turning point in the development of all hydroclimatic variables. The Mann-Kendall test shows a significant decrease in runoff in the winter period. The main causes of runoff decline are: the considerable increase in air temperature, the decrease in snow cover depth and changes in seasonal distribution of precipitation amounts.

  16. Statistical downscaling and projection of future temperature and precipitation change in middle catchment of Sutlej River Basin, India

    Indian Academy of Sciences (India)

    Dharmaveer Singh; Sanjay K Jain; R D Gupta

    2015-06-01

    Ensembles of two Global Climate Models (GCMs), CGCM3 and HadCM3, are used to project future maximum temperature (Max), minimum temperature (Min) and precipitation in a part of Sutlej River Basin, northwestern Himalayan region, India. Large scale atmospheric variables of CGCM3 and HadCM3 under different emission scenarios and the National Centre for Environmental Prediction/National Centre for Atmospheric Research reanalysis datasets are downscaled using Statistical Downscaling Model (SDSM). Variability and changes in Max, Min and precipitation under scenarios A1B and A2 of CGCM3 model and A2 and B2 of HadCM3 model are presented for future periods: 2020s, 2050s and 2080s. The study reveals rise in annual average Max, Min and precipitation under scenarios A1B and A2 for CGCM3 model as well as under A2 and B2 scenarios for HadCM3 model in 2020s, 2050s and 2080s. Increase in mean monthly Min is also observed for all months of the year under all scenarios of both the models. This is followed by decrease in Max during June, July August and September. However, the model projects rise in precipitation in months of July, August and September under A1B and A2 scenarios of CGCM3 model and A2 and B2 of HadCM3 model for future periods.

  17. Seasonal and spatial variability of aquatic N2O, CH4 and CO2 concentrations and their contribution to the overall greenhouse gas budget of the river Tay catchment, NW Europe

    Science.gov (United States)

    Skiba, Ute; Harley, James; Carvalho, Laurence; Heal, Kate; Rees, Bob

    2016-04-01

    River networks act as a link between components of the terrestrial landscape with the atmosphere and oceans, and are believed to contribute significantly to global budgets of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). However, knowledge of flux magnitudes and drivers of seasonal and spatial variability required to understand their contribution to the overall catchment greenhouse (GHG) flux is only available for relatively few river systems. For this reason we conducted a two year study of monthly GHG concentration measurements from the river Tay. The river Tay is the largest river in Scotland, in terms of discharge and can be considered typical for many North European river systems. The Tay and its tributaries drain peat dominated uplands and agricultural lowlands before entering the North Sea via the large intertidal estuary. We collected water samples from 9 locations along the river monthly and analysed these sampes for dissolved concentrations of N2O, CH4 and CO2, NH4+ , NO3-, O2, total organic carbon and nitrogen, pH and turbidity. Fluxes across the air water interface were calculated using published gas transfer equations. All GHGs showed considerable spatial and seasonal variation. Nitrous oxide emissions ranged from 176 to 1850 μg N m-2 d-1 over the almost two year period February 2009 to December 2010. Emissions were highest in the lowland tributaries related to higher nutrient concentrations associated with more intensive agricultural activity. Methane emissions ranged from 1720 to 15500 μg C m-2 d-1, and in general decreased from upland to lowland sites. Variation in sediment quality was the predominant driving factor. Carbon dioxide emissions ranged from 517 to 2550 mg C m-2 d-1 and generally increased from upland to lowland sites. Emissions were highest in late summer and autumn and lowest in winter at most sites, highlighting the role of seasonal environmental controls such as temperature, light, and substrate availability

  18. Value of long-term streamflow forecasts to reservoir operations for water supply in snow-dominated river catchments

    Science.gov (United States)

    Anghileri, D.; Voisin, N.; Castelletti, A.; Pianosi, F.; Nijssen, B.; Lettenmaier, D. P.

    2016-06-01

    We present a forecast-based adaptive management framework for water supply reservoirs and evaluate the contribution of long-term inflow forecasts to reservoir operations. Our framework is developed for snow-dominated river basins that demonstrate large gaps in forecast skill between seasonal and inter-annual time horizons. We quantify and bound the contribution of seasonal and inter-annual forecast components to optimal, adaptive reservoir operation. The framework uses an Ensemble Streamflow Prediction (ESP) approach to generate retrospective, one-year-long streamflow forecasts based on the Variable Infiltration Capacity (VIC) hydrology model. We determine the optimal sequence of daily release decisions using the Model Predictive Control (MPC) optimization scheme. We then assess the forecast value by comparing system performance based on the ESP forecasts with the performances based on climatology and perfect forecasts. We distinguish among the relative contributions of the seasonal component of the forecast versus the inter-annual component by evaluating system performance based on hybrid forecasts, which are designed to isolate the two contributions. As an illustration, we first apply the forecast-based adaptive management framework to a specific case study, i.e., Oroville Reservoir in California, and we then modify the characteristics of the reservoir and the demand to demonstrate the transferability of the findings to other reservoir systems. Results from numerical experiments show that, on average, the overall ESP value in informing reservoir operation is 35% less than the perfect forecast value and the inter-annual component of the ESP forecast contributes 20-60% of the total forecast value.

  19. Catchment export of carbon, nitrogen, and phosphorus across an agro-urban land use gradient, Swan-Canning River system, southwestern Australia

    Science.gov (United States)

    Petrone, Kevin C.

    2010-03-01

    Coastal regions in many regions of the world are under increasing pressure from the expansion of agriculture and urbanization associated with elevated N and P loading and eutrophication of coastal estuaries. I compared how mixed land use catchments deliver dissolved and particulate forms of C, N, and P in streamflow to the Swan-Canning estuary that bisects Perth, Western Australia. Dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) composed the majority of the total C and N load, particulate C and N fluxes were minor, and P fluxes were evenly split between soluble reactive phosphorus and particulate/organic P. In contrast to current biogeochemical theory, DON export was dominant in urban and agricultural catchments in the low-gradient environment of the Swan Coastal Plain, whereas NO3 export was a greater factor in higher-gradient, forested catchments on the urban fringe. This trend suggests that hydrologic conditions that supported coastal wetlands prior to human development may still promote DON mobilization as well as dissolved inorganic nitrogen loss along hydrologic flow paths. Substantial variability in export of C, N, and P across catchments highlights the unique hydrologic properties of Australian catchments. Areal C, N, and P export was significantly related to catchment runoff which was lowest in a catchment with inland drainage, but greatest in urban catchments with impervious surfaces and shallow groundwater. The effective delivery of DOC and DON to aquatic ecosystems in urbanizing coastal catchments underscores the importance of restoration efforts that address hydrologic retention as well as the source and bioavailability of dissolved organic matter.

  20. Spatial and temporal variation in pH, alkalinity and conductivity in surface runoff and groundwater for the Upper River Severn catchment

    Directory of Open Access Journals (Sweden)

    T. Hill

    1997-01-01

    Full Text Available Measurements of pH, alkalinity and electrical conductivity are used to examine the extent of the spatial and temporal variation in stream and ground water chemistry for the Upper Severn catchment, Plynlimon. Wide temporal variations in stream waters broadly reflect flow conditions and complex soil and ground water interactions but not soil type, land usage or geology. The results have major implications for the use of critical load analysis and the development and application of models in upland catchments. They point to the value of field measurements for assessing the environmental management of upland catchments, rather than the present use of over simplistic or inappropriate models.

  1. Catchment source contributions to the sediment-bound organic matter degrading salmonid spawning gravels in a lowland river, southern England

    Energy Technology Data Exchange (ETDEWEB)

    Collins, A.L., E-mail: adrian.collins@adas.co.uk [ADAS, Pendeford House, Wobaston Road, Wolverhampton WV9 5AP (United Kingdom); Geography and Environment, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom); Williams, L.J.; Zhang, Y.S. [ADAS, Pendeford House, Wobaston Road, Wolverhampton WV9 5AP (United Kingdom); Marius, M. [Civil Engineering and Environment, University of Southampton, Highfield, Southampton S017 1BJ (United Kingdom); Dungait, J.A.J. [Department of Sustainable Systems and Grassland Science, Rothamsted Research—North Wyke, Okehampton, Devon EX20 2SB (United Kingdom); Smallman, D.J. [Civil Engineering and Environment, University of Southampton, Highfield, Southampton S017 1BJ (United Kingdom); Dixon, E.R. [Department of Sustainable Systems and Grassland Science, Rothamsted Research—North Wyke, Okehampton, Devon EX20 2SB (United Kingdom); Stringfellow, A. [Civil Engineering and Environment, University of Southampton, Highfield, Southampton S017 1BJ (United Kingdom); Sear, D.A. [Geography and Environment, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom); Jones, J.I. [School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS (United Kingdom); Naden, P.S. [CEH Wallingford, Maclean Building, Benson Lane, Crowmarsh Gifford, Wallingford, Oxfordshire, OX10 8BB (United Kingdom)

    2013-07-01

    The ingress of particulate material into freshwater spawning substrates is thought to be contributing to the declining success of salmonids reported over recent years for many rivers. Accordingly, the need for reliable information on the key sources of the sediment problem has progressed up the management agenda. Whilst previous work has focussed on apportioning the sources of minerogenic fine sediment degrading spawning habitats, there remains a need to develop procedures for generating corresponding information for the potentially harmful sediment-bound organic matter that represents an overlooked component of interstitial sediment. A source tracing procedure based on composite signatures combining bulk stable {sup 13}C and {sup 15}N isotope values with organic molecular structures detected using near infrared (NIR) reflectance spectroscopy was therefore used to assess the primary sources of sediment-bound organic matter sampled from artificial spawning redds. Composite signatures were selected using a combination of the Kruskal–Wallis H-test, principal component analysis and GA-driven discriminant function analysis. Interstitial sediment samples were collected using time-integrating basket traps which were inserted at the start of the salmonid spawning season and extracted in conjunction with critical phases of fish development (eyeing, hatch, emergence, late spawning). Over the duration of these four basket extractions, the overall relative frequency-weighted average median (± 95% confidence limits) source contributions to the interstitial sediment-bound organic matter were estimated to be in the order: instream decaying vegetation (39 ± < 1%; full range 0–77%); damaged road verges (28 ± < 1%; full range 0–77%); septic tanks (22 ± < 1%; full range 0–50%), and; farm yard manures/slurries (11 ± < 1%; full range 0–61%). The reported procedure provides a promising basis for understanding the key sources of interstitial sediment-bound organic matter

  2. Seasonal and spatial variability of {sup 210}Po, {sup 238}U and {sup 239+240}Pu levels in the river catchment area assessed by application of neural-network based classification

    Energy Technology Data Exchange (ETDEWEB)

    Skwarzec, Bogdan [University of Gdansk, Faculty of Chemistry, Chair of Analytical Chemistry, 18/19 Sobieskiego Street, 80-952 Gdansk (Poland)], E-mail: bosk@chem.univ.gda.pl; Kabat, Krzysztof [University of Gdansk, Faculty of Chemistry, Chair of Analytical Chemistry, 18/19 Sobieskiego Street, 80-952 Gdansk (Poland); Astel, Aleksander [Pomeranian Academy, Biology and Environmental Protection Institute, Environmental Chemistry Research Unit, 22a Arciszewskiego Street, 76-200 Slupsk (Poland)

    2009-02-15

    The present study deals with the application of self-organizing maps (SOM) in order to model, classify and interpret seasonal and spatial variability of {sup 210}Po, {sup 238}U and {sup 239+240}Pu levels in the Vistula river basin. The data set represents concentration values for 3 alpha emitters ({sup 210}Po, {sup 238}U and {sup 239+240}Pu) measured in surface water samples collected at 19 different sampling locations (8 in major Vistula stream while 11 in right or left Vistula tributaries) during four seasons (winter, spring, summer and autumn) in the framework of a one-year quality monitoring study. The advantages of an SOM algorithm, its classification and visualization ability for environmental data sets, are stressed. The neural-network based classification made it possible to reveal specific patterns related to both seasonal and spatial variability. In the middle and upper part of Vistula catchment as well as in the right-shore tributaries, concentrations of {sup 210}Po and {sup 238}U during summer and winter are the lowest. Concentrations of {sup 210}Po and {sup 238}U increase significantly during spring and autumn in the Vistula river catchment, especially in the delta of Vistula river. High concentration of anthropogenic originated {sup 239+240}Pu indicates 'site-specific' character of pollution in two large left-shore tributaries located in the middle part of the Vistula drainage area. Efficient classification of sampling locations could lead to an optimization of river radiochemical sampling networks and to a better tracing of natural and anthropogenic changes along Vistula river stream.

  3. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: Average Daily Minimum Temperature, 2002

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This tabular data set represents the average daily minimum temperature in Celsius multiplied by 100 for 2002, compiled for every MRB_E2RF1 catchment of selected...

  4. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: 30-Year Average Annual Precipitation, 1971-2000

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This tabular data set represents the 30-year (1971-2000) average annual precipitation in millimeters multiplied by 100 compiled for every MRB_E2RF1 catchment of...

  5. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: Average Saturation Excess-Overland Flow, 2002

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This tabular data set represents the average value of saturation overland flow, in percent of total streamflow, compiled for every MRB_E2RF1 catchment of selected...

  6. Sediments in urban river basins: identification of sediment sources within the Lago Paranoá catchment, Brasilia DF, Brazil - using the fingerprint approach.

    Science.gov (United States)

    Franz, C; Makeschin, F; Weiß, H; Lorz, C

    2014-01-01

    The development of effective sediment management strategies is a key requirement in tropical areas with fast urban development, like Brasilia DF, Brazil, because of the limited resources available. Accurate identification and management of sediment sources areas, however, is hampered by the dearth of reliable information on the primary sources of sediment. Few studies have attempted to quantify the source of sediment within fast urbanizing, mixed used, tropical catchments. In this study, statistically verified composite fingerprints and a multivariate mixing model have been used to identify the main land use specific sources of sediment deposited in the artificial Lago Paranoá, Central Brazil. Because of the variability of urban land use types within the Lago Paranoá sub-catchments, the fingerprinting approach was additionally undertaking for the Riacho Fundo sub-catchment. The main contributions from individual source types (i.e. surface materials from residential areas, constructions sites, road deposited sediment, cultivated areas, pasture, farm tracks, woodland and natural gullies) varied between the whole catchment and the Riacho Fundo sub-catchment, reflecting the different proportions of land uses. The sediments deposited in the silting zones of the Lago Paranoá originate largely from urban sources (85 ± 4%). Areas with (semi-) natural vegetation and natural gullies contribute 10 ± 2% of the sediment yield. Agricultural sites have only a minor sediment contribution of about 5 ± 4% within the whole catchment. Within the Riacho Fundo sub-catchment there is a significant contribution from urban (53 ± 4%) source, such as residential areas with semi-detached housings (42 ± 3%) with unpaved roads (12 ± 3%) and construction sites (20 ± 3%) and agricultural areas (31 ± 2%). The relative contribution from land use specific sources to the sediment deposition in the silting zone of the Lago Paranoá demonstrated that most of the sediment is derived from

  7. Stable isotope hydrology in fractured and detritic aquifers at both sides of the South Atlantic Ocean: Mar del Plata (Argentina) and the Rawsonville and Sandspruit river catchment areas (South Africa)

    Science.gov (United States)

    Glok Galli, Melisa; Damons, Matthew E.; Siwawa, Sitembiso; Bocanegra, Emilia M.; Nel, Jacobus M.; Mazvimavi, Dominic; Martínez, Daniel E.

    2017-01-01

    The aim of this work is to characterize the isotope composition of water (2H and 18O) in order to establish the relationship between fractured and detritic aquifers in similar hydrological environments located at both sides of the Atlantic Ocean. The Mar del Plata zone, placed in the Argentine Buenos Aires province in South America, and the Rawsonville and Sandspruit river catchment areas, situated in the Western Cape province in South Africa were compared. Rainwater and groundwater samples from fractured and detritic aquifers were analyzed through laser spectroscopy. In both Argentina and South African study sites, stable isotopes data demonstrate an aquifers recharge source from rainfall. For the Mar del Plata region, two different groups of detritic aquifer's samples with distinct recharge processes can be identified due to the close relationship existing between the present hydrogeological environments, the aquifer's grain size sediments and the isotopes contents: one representing rapid infiltration in aquifer sediments of the creeks' palaeobeds and hills zones (sandy or silt sandy sediments) and the other with slow infiltration of evaporated water in plain zones with an aquitard behavior. In the last group, the evaporation process occurs previous infiltration or in the aquifer's non-saturated zone, because of the existence of very low topographic gradients and fine-grained sediments. The evaporation phenomenon is not evident in the Sandspruit river catchment site's detritic aquifer, because its sandy composition allows a faster infiltration rate than in the loess that compounds the Pampeano aquifer in the interfluves zones of the Argentinian study area.

  8. Multi-time-scale hydroclimate dynamics of a regional watershed and links to large-scale atmospheric circulation: Application to the Seine river catchment, France

    Science.gov (United States)

    Massei, N.; Dieppois, B.; Hannah, D. M.; Lavers, D. A.; Fossa, M.; Laignel, B.; Debret, M.

    2017-03-01

    In the present context of global changes, considerable efforts have been deployed by the hydrological scientific community to improve our understanding of the impacts of climate fluctuations on water resources. Both observational and modeling studies have been extensively employed to characterize hydrological changes and trends, assess the impact of climate variability or provide future scenarios of water resources. In the aim of a better understanding of hydrological changes, it is of crucial importance to determine how and to what extent trends and long-term oscillations detectable in hydrological variables are linked to global climate oscillations. In this work, we develop an approach associating correlation between large and local scales, empirical statistical downscaling and wavelet multiresolution decomposition of monthly precipitation and streamflow over the Seine river watershed, and the North Atlantic sea level pressure (SLP) in order to gain additional insights on the atmospheric patterns associated with the regional hydrology. We hypothesized that: (i) atmospheric patterns may change according to the different temporal wavelengths defining the variability of the signals; and (ii) definition of those hydrological/circulation relationships for each temporal wavelength may improve the determination of large-scale predictors of local variations. The results showed that the links between large and local scales were not necessarily constant according to time-scale (i.e. for the different frequencies characterizing the signals), resulting in changing spatial patterns across scales. This was then taken into account by developing an empirical statistical downscaling (ESD) modeling approach, which integrated discrete wavelet multiresolution analysis for reconstructing monthly regional hydrometeorological processes (predictand: precipitation and streamflow on the Seine river catchment) based on a large-scale predictor (SLP over the Euro-Atlantic sector). This

  9. Adjustment of Peak Streamflows of a Tropical River for Urbanization

    OpenAIRE

    Ata Amini; Thamer M. Ali; Abdul H.B. Ghazali; Bujang K. Huat

    2009-01-01

    Peak runoff from a catchment is influenced by many factors such as intensity and duration of rainfall, catchment topography, catchment shape, land use and other variables. For a particular catchment, landuse change and other human activities will alter the characteristic of catchment hydrograph. Problem statement: As a result of urbanization, the magnitude of floods occurring in a catchment increased. It was found that the land use change in the Langat River catchment has clear impact on annu...

  10. Management of human-induced salinisation in the Berg River catchment and development of criteria for regulating agricultural land use in terms of salt generating capacity

    CSIR Research Space (South Africa)

    Jovanovic, W

    2013-04-01

    Full Text Available From previous WRC work by the same group, various needs were identified. One was to examine the effects a range of land uses may have on the production of salinity from the Sandspruit catchment. Another was to develop criteria to manage the salt...

  11. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: 30-Year Average Annual Precipitation, 1971-2000

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This tabular data set represents the 30-year (1971-2000) catchment-average total annual precipitation in millimeters multiplied by 100 compiled for every MRB_E2RF1...

  12. Topic: Catchment system dynamics: Processes and feedbacks

    Science.gov (United States)

    Keesstra, Saskia

    2015-04-01

    In this meeting we can talk about my main expertise: the focus of my research ocus revolves around understanding catchment system dynamics in a holistic way by incorporating both processes on hillslopes as well as in the river channel. Process knowledge enables explanation of the impact of natural and human drivers on the catchment systems and which consequences these drivers have for water and sediment connectivity. Improved understanding of the catchment sediment and water dynamics will empower sustainable land and river management and mitigate soil threats like erosion and off-side water and sediment accumulation with the help of nature's forces. To be able to understand the system dynamics of a catchment, you need to study the catchment system in a holistic way. In many studies only the hillslopes or even plots are studied; or only the channel. However, these systems are connected and should be evaluated together. When studying a catchment system any intervention to the system will create both on- as well as off sites effects, which should especially be taken into account when transferring science into policy regulations or management decisions.

  13. Multi-isotope tracers to investigate processes in the Elbe, Weser and Ems river catchment using B, Mo, Sr, and Pb isotope ratios assessed by MC ICP-MS

    Science.gov (United States)

    Irrgeher, Johanna; Reese, Anna; Zimmermann, Tristan; Prohaska, Thomas; Retzmann, Anika; Wieser, Michael E.; Zitek, Andreas; Proefrock, Daniel

    2017-04-01

    Environmental monitoring of complex ecosystems requires reliable sensitive techniques based on sound analytical strategies to identify the source, fate and sink of elements and matter. Isotopic signatures can serve to trace pathways by making use of specific isotopic fingermarks or to distinguish between natural and anthropogenic sources. The presented work shows the potential of using the isotopic variation of Sr, Pb (as well-established isotopic systems), Mo and B (as novel isotopic system) assessed by MC ICP-MS in water and sediment samples to study aquatic ecosystem transport processes. The isotopic variation of Sr, Pb, Mo and B was determined in different marine and estuarine compartments covering the catchment of the German Wadden Sea and its main tributaries, the Elbe, Weser and Ems River. The varying elemental concentrations, the complex matrix and the expected small variations in the isotopic composition required the development and application of reliable analytical measurement approaches as well as suited metrological data evaluation strategies. Aquatic isoscapes were created using ArcGIS® by relating spatial isotopic data with geographical and geological maps. The elemental and isotopic distribution maps show large variation for different parameters and also reflect the numerous impact factors (e.g. geology, anthropogenic sources) influencing the catchment area.

  14. Incorporating flood event analyses and catchment structures into model development

    Science.gov (United States)

    Oppel, Henning; Schumann, Andreas

    2016-04-01

    The space-time variability in catchment response results from several hydrological processes which differ in their relevance in an event-specific way. An approach to characterise this variance consists in comparisons between flood events in a catchment and between flood responses of several sub-basins in such an event. In analytical frameworks the impact of space and time variability of rainfall on runoff generation due to rainfall excess can be characterised. Moreover the effect of hillslope and channel network routing on runoff timing can be specified. Hence, a modelling approach is needed to specify the runoff generation and formation. Knowing the space-time variability of rainfall and the (spatial averaged) response of a catchment it seems worthwhile to develop new models based on event and catchment analyses. The consideration of spatial order and the distribution of catchment characteristics in their spatial variability and interaction with the space-time variability of rainfall provides additional knowledge about hydrological processes at the basin scale. For this purpose a new procedure to characterise the spatial heterogeneity of catchments characteristics in their succession along the flow distance (differentiated between river network and hillslopes) was developed. It was applied to study of flood responses at a set of nested catchments in a river basin in eastern Germany. In this study the highest observed rainfall-runoff events were analysed, beginning at the catchment outlet and moving upstream. With regard to the spatial heterogeneities of catchment characteristics, sub-basins were separated by new algorithms to attribute runoff-generation, hillslope and river network processes. With this procedure the cumulative runoff response at the outlet can be decomposed and individual runoff features can be assigned to individual aspects of the catchment. Through comparative analysis between the sub-catchments and the assigned effects on runoff dynamics new

  15. Sediment tracing from small torrential channels to gravel-bed rivers using pit tags method. A case study from the upper Guil catchment.

    Science.gov (United States)

    Graff, Kévin; Viel, Vincent; Carlier, Benoit; Lissak, Candide; Arnaud-Fassetta, Gilles; Fort, Monique; Madelin, Malika

    2016-04-01

    In mountainous areas, especially in large catchments with torrential tributaries, the production and sediment transport significantly increase flood impacts in the valley bottoms. The quantification and characterisation of sedimentary transfers are therefore major challenges to provide better flood risk management. As a part of SAMCO (ANR 12 SENV-0004 SAMCO) project, for mountain hazard assessment in a context of global changes, we tried to improve the knowledge of these hydromorphological systems at both spatial and temporal scales, by identifying sediment supply and sediment dynamics from torrential tributaries to the main channel. A sediment budget was used as a tool for quantifying erosion, transport and deposition processes. This research is focused on the upper Guil catchment (Queyras, Southern French Alps - 317 km2) entrenched in "schistes lustrés" and ophiolitic bedrock. This catchment is prone to catastrophic summer floods [June 1957 (>R.I. 100 yr), June 2000 (R.I. 30 yr)] characterised by huge sediment transport from tributaries to downvalley, very much facilitated by strong hillslope-channel connectivity (about 12,000 m3 volume of sediment aggraded in the Peyronnelle fan during the June 2000 RI-30 year flood event). We intend to highlight sediment dynamics on small torrential channels and its connection with gravel-bed streams. Four study sites characterised by avalanche and debris flow-dominated channels located in the upper Guil catchment were investigated. In order to better assess sediment movement, we used the pit-tags technique. In total, 560 pit-tags (pt) have been implemented in four catchments: Peyronnelle (320pt), Combe Morel (40pt), Bouchouse (120pt), and Maloqueste (80pt). Distances and trajectories of gravels sediments have been monitored since two years during summer periods. We specifically describe results obtained along the Peyronnelle channel affected by a large debris-flow during august 2015. Data are used to discuss lag time

  16. An approach to predict water quality in data-sparse catchments using hydrological catchment similarity

    Science.gov (United States)

    Pohle, Ina; Glendell, Miriam; Stutter, Marc I.; Helliwell, Rachel C.

    2017-04-01

    An understanding of catchment response to climate and land use change at a regional scale is necessary for the assessment of mitigation and adaptation options addressing diffuse nutrient pollution. It is well documented that the physicochemical properties of a river ecosystem respond to change in a non-linear fashion. This is particularly important when threshold water concentrations, relevant to national and EU legislation, are exceeded. Large scale (regional) model assessments required for regulatory purposes must represent the key processes and mechanisms that are more readily understood in catchments with water quantity and water quality data monitored at high spatial and temporal resolution. While daily discharge data are available for most catchments in Scotland, nitrate and phosphorus are mostly available on a monthly basis only, as typified by regulatory monitoring. However, high resolution (hourly to daily) water quantity and water quality data exist for a limited number of research catchments. To successfully implement adaptation measures across Scotland, an upscaling from data-rich to data-sparse catchments is required. In addition, the widespread availability of spatial datasets affecting hydrological and biogeochemical responses (e.g. soils, topography/geomorphology, land use, vegetation etc.) provide an opportunity to transfer predictions between data-rich and data-sparse areas by linking processes and responses to catchment attributes. Here, we develop a framework of catchment typologies as a prerequisite for transferring information from data-rich to data-sparse catchments by focusing on how hydrological catchment similarity can be used as an indicator of grouped behaviours in water quality response. As indicators of hydrological catchment similarity we use flow indices derived from observed discharge data across Scotland as well as hydrological model parameters. For the latter, we calibrated the lumped rainfall-runoff model TUWModel using multiple

  17. The flash flood event in the catchment of the river Weisseritz (eastern Erzgebirge, Saxony) from 12.-14. August 2002 - meteorological and hydrological reasons, damage assesment and disaster managment

    Science.gov (United States)

    Goldberg, V.; Bernhofer, Ch.

    2003-04-01

    Between 12. and 14. August 2002 the region of eastern Erzgebirge (Saxony/Eastern Germany) was affected by the heaviest rainfall event recorded since beginning of the measuring period in 1883. The synoptic reason of this event was the advective precipitation due to the strong and very slowly shifting Vb-low "Ilse" combined with a noticeable topographic intensification by north-westerly winds. All stations in the catchment area of the river Weisseritz recorded new all-time records. E.g., at the meteorological station Zinnwald-Georgenfeld situated at the crest of eastern Erzgebirge a daily sum of 312 mm was measured for the 13. August. This value is close to the maximum physically possible rainfall. The intensive rainfall in the catchments of Rote Weisseritz and Wilde Weisseritz led to unexperienced heavy flash floods with large material transport and flow damages. The buffer effect of the existing dam systems was comparatively small because the reserved retaining capacity for flood protection was only about 20 percent of the total capacity. The reservoirs filled quickly due to the very high maximum inflow. So a long-time overflow of the dam system occurred with a maximum of about 300 cubic meters per second at the combined river Weisseritz through the cities of Freital and Dresden (This situation led, e.g., to the flooding of Central Railway Station in Dresden). This water flow is comparable with a medium flow rate of the river Elbe in Dresden, and it is about 300 times higher than the normal drain of the river Weisseritz in Freital! The material damages in the Weisseritz region account for several hundred millions EURO, and several causalties occurred. The damages of the University buildings in Tharandt (including one building of the Department of Meteorology) account for 15 millions EURO alone. The disaster management during the flood was not optimal. For many people, e.g. in Tharandt, there was neither an officially warning nor an organised rescue of movable goods

  18. How can we cope with the complexity of the environment? A "Learning by modelling" approach using qualitative reasoning for developing causal models and simulations with focus on Sustainable River Catchment Management

    Science.gov (United States)

    Poppe, Michaela; Zitek, Andreas; Salles, Paulo; Bredeweg, Bert; Muhar, Susanne

    2010-05-01

    The education system needs strategies to attract future scientists and practitioners. There is an alarming decline in the number of students choosing science subjects. Reasons for this include the perceived complexity and the lack of effective cognitive tools that enable learners to acquire the expertise in a way that fits its qualitative nature. The DynaLearn project utilises a "Learning by modelling" approach to deliver an individualised and engaging cognitive tool for acquiring conceptual knowledge. The modelling approach is based on qualitative reasoning, a research area within artificial intelligence, and allows for capturing and simulating qualitative systems knowledge. Educational activities within the DynaLearn software address topics at different levels of complexity, depending on the educational goals and settings. DynaLearn uses virtual characters in the learning environment as agents for engaging and motivating the students during their modelling exercise. The DynaLearn software represents an interactive learning environment in which learners are in control of their learning activities. The software is able to coach them individually based on their current progress, their knowledge needs and learning goals. Within the project 70 expert models on different environmental issues covering seven core topics (Earth Systems and Resources, The Living World, Human population, Land and Water Use, Energy Resources and Consumption, Pollution, and Global Changes) will be delivered. In the context of the core topic "Land and Water Use" the Institute of Hydrobiology and Aquatic Ecosystem Management has developed a model on Sustainable River Catchment Management. River systems with their catchments have been tremendously altered due to human pressures with serious consequences for the ecological integrity of riverine landscapes. The operation of hydropower plants, the implementation of flood protection measures, the regulation of flow and sediment regime and intensive

  19. 基于水资源生态足迹的浑河流域水资源利用评价%Assessing Utilization of Water Resources in Hunhe River Catchment Based on Ecological Footprint

    Institute of Scientific and Technical Information of China (English)

    王秀颖; 刘和平

    2016-01-01

    用水资源生态足迹模型计算浑河流域2005~2013年水资源生态足迹和水资源生态承载力,并基于各评价指标对浑河流域水资源利用情况进行评价。结果表明:2005~2013年浑河流域水资源生态足迹呈现不显著的下降趋势,水资源生态承载力呈现波动变化;流域一直处于水资源生态赤字状态,仅在2010年出现盈余;流域水资源生态足迹指数低于可持续发展足迹指数范围,但万元GDP水资源生态足迹持续下降。总体来看,流域水资源利用处于不可持续状态,但2010年后流域水资源利用效率明显提高,并向着可持续的方向发展。%The water resources ecoLogicaL footprint and ecoLogicaL carrying capacity in the Hunhe River catchment from 2005 to 2013 were caLcuLated according to the water resources ecoLogicaL footprint modeL, and the utiLization of water resources in the catchment was assessed based on the caLcuLated index. The resuLts are as foLLows:from 2005 to 2013, the water resources ecoLogicaL footprint in the Hunhe River catchment show a non-significant downward trend, whiLe the water resources ecoLogicaL carrying capacity fLuctuated and was significantLy reLated to precipitation in the catchment. There was ecoLogicaL deficit of water resources in aLL the years from 2005 to 2013 but 2010, when there was a surpLus. The water resources ecoLogicaL footprint index was beLow the range of the sustainabiLity, but the water resources ecoLogicaL footprint per 10 4 Yuan GDP continued to decrease. Over aLL, the water resources utiLization in the catchment was unsustainabiLity, but the utiLization efficiency improved obviousLy and it was deveLoping towards sustainabiLity since 2010.

  20. CHEMICAL WEATHERING OF LARGE RIVER CATCHMENTS IN CHINA AND THE GLOBAL CARBON CYCLE%中国河流流域化学风化和全球碳循环

    Institute of Scientific and Technical Information of China (English)

    吴卫华; 郑洪波; 杨杰东; 罗超; 周斌

    2011-01-01

    通过研究中国境内九大水系中大河流域的河水、大气降水、沉积物和岩体中的化学成分并结合水文信息,对流域中的化学风化作用及其消耗大气CO的能力与机制进行了粗略的调查,探讨了不同气候、岩性、地形、植被等条件下化学风化的变化趋势,分析了控制风化反应的因素,为在我国境内进行CO捕获与封存的场地、矿物类型选择提供了参考和依据.研究结果表明,我国境内河流流域硅酸盐和碳酸盐风化所消耗的大气CO分别为421×10~627×10mol/a和1323×10~2025×10mol/a,占全球河流消耗总量的4.8%~7.1%和11.1%~16.1%,显示我国作为岩溶大量分布的国家,碳酸盐风化作为一个短时间尺度上的碳汇对全球碳循环的影响更为突出.长江、黄河和珠江3条河流流域硅酸盐风化所消耗的大气CO量占全国河流的约2/3,而碳酸盐风化消耗的大气CO量占全国河流的近90%.通过对比一些典型硅酸盐岩地区河流的化学风化特征发现,热带气候条件下流经玄武岩地层的海南南渡江有着最高的硅酸盐风化速率(7.2×10mol/km·a),与赤道附近的新几内亚岛上河流相近.而在岩性相似的情况下,大气CO消耗速率与气温和降雨量呈正相关,与海拔成反相关关系.%By analyzing the chemical compositions of river waters, rain waters, surface sediments, and rocks of large river catchments in China, combining with hydrological information, this paper uses the forward model to assess the chemical weathering rates, capacity and mechanism of the atmospheric CO2 consumption and then discusses the behaviors of chemical weathering under various conditions including climate, lithology, topography, and vegetation.The study also provides reference and basic information for selecting of sites and mineral types for CO2 capture and storage in China. The atmospheric CO2 consumptions derived from silicate and carbonate weathering in China are 421

  1. Cesium-137 global fallout into the Ob river basin and its influence on the Kara sea contamination - Weapons fallout cesium-137 in the Ob' catchment landscapes and its influence on radioactive contamination of the Kara sea: Western Siberia, Russia

    Energy Technology Data Exchange (ETDEWEB)

    Semenkov, Ivan N.; Miroshnikov, Alexey Yu. [The Organization of Russian Academy of Sciences Institute of geology of ore deposits, petrography, mineralogy and geochemistry Russian Academy of Sciences (Russian Federation)

    2014-07-01

    There are several high level {sup 137}Cs anomaly zones detected in the deposits of the SW part of the Kara Sea. These anomaly zones were formed in the Ob' and the Enisey river estuaries due to the geochemical 'river-sea' boarder barrier. Level of radiocaesium specific activity reaches 120 Bq*kg{sup -1} in the deposits from these zones. Radiochemical enterprises occur in the both river basins. Their activity results in caesium-137 transfer into the river net. Vast area is contaminated by {sup 137}Cs after nuclear weapons in Semipalatinsk test-site and Kyshtym disaster in the Ob' river basin. Moreover, caesium comes to the Ob' and the Enisey river basins with global atmospheric fallout. The inflow of global fallout caesium-137 to the catchments is 660 kCi (320 kCi including radioactive decay) that is 4 times higher than {sup 137}Cs emission due to Fukushima disaster. Therefore, these river basins as any other huge catchment are an important sources of radioactive contamination of the Arctic Ocean. The aim of our research is to study behavior of global fallout caesium-137 in the landscapes of the Ob and the Enisey river basins. We studied caesium-137 behavior on the example of first order catchments in taiga, wetland, forest-steppe, steppe, and semi-arid landscapes. Geographic information system (GIS) was made. The tenth-order catchments (n=154, Horton coding system) shape 20-groups due to topsoil properties controlling cesium mobility. Eleven first-order basins, characterized 7 groups of tenth order catchments, were studied. And 700 bulk-core soil samples were collected in 2011-2013. Cesium runoff is calculated for 3 first-order river basins in taiga and forest-steppe landscapes. Storage of global fallout caesium-137 declines from undisturbing taiga first-order river basin (90% of cumulative fallout including radioactive decay)> arable steppe and fores-steppe (70 - 75%)> undisturbing wetland (60%). Caesium-137 transfer is high in arable lands

  2. UnLoadC3: Ensembles of climate change projections for two river catchment areas in Austria - Contributions to an overall uncertainty assessment framework for the modelling of water quantity and nutrient transport

    Science.gov (United States)

    Matulla, Christoph; Hollosi, Brigitta; Schulz, Karsten; Schürz, Christoph; Mehdi, Bano; Ertl, Thomas; Pressl, Alexander

    2017-04-01

    The objective of UnLoadC3 is to examine the impacts of uncertainty - inherent in data and modelling - on projections of water flow and nutrient transport within two selected river catchment areas (Schwechat and Raab in Austria) under climate change conditions. To access future climate change, ensembles of climate projections from the EURO-CORDEX initiative - given on grids with a 12 km spacing - have been used. These ensembles have been driven by two RCPs (RCP4.5 and RCP8.5) used within the Fifth Assessment Report of the IPCC. In order to provide climate change projections on the required impact scales, statistical downscaling techniques as well as bias correction methods have been applied. Climate variables, such as minimum, maximum, mean temperature and precipitation totals given on a daily base were analyzed. This local scale daily information is entered into the water quality model SWAT, which simulates water balance, pertaining sediment- and nutrient-transport processes across the two considered river watersheds.

  3. A new perspective on catchment storage gained from a nested catchment experiment in Luxembourg (Europe)

    Science.gov (United States)

    Pfister, Laurent; Klaus, Julian; Hissler, Christophe; François Iffly, Jean; Gourdol, Laurent; Martinez-Carreras, Nuria; McDonnell, Jeffrey J.

    2014-05-01

    Recent hydrological process research focussed on how much water a catchment can store and how these catchments store and release water. Storage can be a valuable metric for catchment description, inter-comparison, and classification. Further storage controls catchment mixing, non-linearities in rainfall-runoff transformation and eco-hydrological processes. Various methods exist to determine catchment storage (e.g. natural tracer, soil moisture and groundwater data, hydrological models). Today it remains unclear what parts of the catchment storage are measured with the different models. Here we present a new hydrometric approach to answer the question how much water a catchment can store. We tested our approach in a dense hydro-climatological monitoring network that encompasses 16 recording streamgauges and 21 pluviographs in the Alzette River basin in Luxembourg (Europe). Catchment scales are ranging from 0.47 to 285 km2 and they have clean- and mixed combinations of distinct geologies ranging from schists to marls, sandstone, dolomite and limestone. Previous investigations in the area of interest have shown that geology largely controls winter runoff coefficients. Here, we focus at how catchment geology is ultimately affecting catchment storage. We used the approach of Sayama et al. (2011) to compute catchment dynamic storage changes for each winter season over the period 2002-2012 (based on precipitation as input; discharge and evapotranspiration as output). We determined dynamic storage changes for each winter semester (October to March) in all 16 catchments over the period 2002-2012. At the beginning of each hydrological winter season, all catchments showed similar trends in storage change. A few weeks into the winter season, catchments with lowest permeability (e.g. marls) started to plateau. The highest storage values were reached several months later in the season in catchments dominated by permeable substrate (e.g. sandstone). For most catchments, we found

  4. Exceptional hydrological phenomena in the Gemenea catchment

    Directory of Open Access Journals (Sweden)

    Florentina LIVARCIUC

    2015-10-01

    Full Text Available Flash floods, accompanied by high waters and regular floods, represent the most dangerous natural hazards in the Gemenea catchment, inducing other risks such as geomorphologic, environmental, social and economical risks. Flash floods occurred during the 1969 to 2014 monitoring interval are characterized by extremely high discharge values, of 68.9 m3/s in 2006 and 95.3 m3/s in 2008 and a magnitude 2.5 times higher than the average discharge recorded until that timeframe. With an area of 77.7 km2, the Gemenea catchment falls into the category of small catchments, where the peak discharge during exceptional hydrological phenomena is caused by torrential rainfall. Flash floods of particularly high intensities caused serious damages through: total destruction or damage of the torrent correction works, clogging of culverts on catchment forest roads, failure of river banks and deterioration of the bridges that affected roads and homes in Gemenea, Slătioara and Stulpicani villages. These floods have also caused damage to the forest/agriculture fund through deep and lateral erosion, failure of river banks and landslides. Within this study we aim to emphasize the magnitude, frequency, duration and area of manifestation of such phenomena in the Gemenea catchment. Furthermore, we aim to advance our knowledge of the genesis and specific mechanisms of flash flood occurrence for reducing their negative impacts on the local environment and communities

  5. Runoff generation mechanism at two distinct headwater catchments - isotopic evidence

    Science.gov (United States)

    Dohnal, Michal; Votrubová, Jana; Šanda, Martin; Tesař, Miroslav; Vogel, Tomáš; Dušek, Jaromír

    2016-04-01

    Data from two headwater catchments indicate considerably different runoff formation mechanisms. The contributions of different surface and subsurface runoff mechanisms to the catchment discharge formation at these two small forested headwater catchments are studied with help of the natural isotopic signatures of the observed fluxes. The Uhlirska catchment (1.78 sq. km, Jizera Mts., Czech Republic) is situated in headwater area of Cerna Nisa stream. Deluviofluvial granitic sediments in the valley bottom areas (riparian zones/wetlands) are surrounded by gentle hillslopes with shallow soils developed on crystalline bedrock. The Liz catchment (0.99 sq. km, Bohemian Forest, Czech Republic) belongs to hillslope-type catchments without riparian zones situated in headwater area of Volynka River. The soil at Liz is developed on biotite paragneiss bedrock. Autocorrelation analysis of the measured catchment discharge rates reveals different hydrograph characteristics for each of the two catchments. Estimated autocorrelation lengths differ by an order of magnitude. Variations of oxygen-18 isotope concentrations in precipitation, groundwater and streamflow were analyzed. Several significant rainfall-runoff events at each of the two catchments were analyzed in detail. These events exhibit substantial difference in isotopic compositions of event and pre-event water, which facilitates hydrograph separation. Clockwise and counterclockwise hysteretic relationships between the stream discharge and its isotope concentration were identified. Results were confronted with the previously published concepts of the runoff formation at the catchments under study. The research was funded by the Czech Science Foundation, project No. 14-15201J.

  6. A numerical solution to integrated water flows: Application to the flooding of an open pit mine at the Barcés river catchment - La Coruña, Spain

    Science.gov (United States)

    Hernández, J.-Horacio; Padilla, Francisco; Juncosa, Ricardo; Vellando, Pablo R.; Fernández, Álvaro

    2012-11-01

    SummaryThis research and practical application is concerned with the development of a physically-based numerical model that incorporates new approaches for a finite element solution to the steady/transient problems of the joint surface/groundwater flows of a particular region with the help of a Geographic Information Systems to store, represent, manage and take decisions on all the simulated conditions. The proposed surface-subsurface model considers surface and groundwater interactions to be depth-averaged through a novel interpretation of a linear river flood routing method. Infiltration rates and overland flows generation processes are assessed by a sub-model which accounts for this kind of surface-groundwater interactions. Surface-groundwater interactions consider also novel evaporation and evapotranspiration processes as a diffuse discharge from surface water, non-saturated subsoil and groundwater table. The practical application regards the present flooding of the Meirama open pit, a quite deep coal mining excavation, with freshwater coming from the upper Meirama sub-basin, in the context of the water resources fate and use at the Barcés river catchment (˜87.9 km2), Coruña, Spain. The developed model MELEF was applied to the complex geology of a pull-apart type sedimentary tertiary valley and the whole of the water resources of the Barcés River drainage basin, down to its outlet at the Cecebre Reservoir. Firstly, the model was adapted and calibrated during a simulation period of three and a half years (2006/2009) with the aid of the historically registered hydrological parameters and data. Secondly, the results predict the most likely forthcoming evolution of the present flooding of the Meirama open pit to reach therein a total depth level of almost 200 m, as regards the projected evolution of the water resources, climatology and usages.

  7. Flash-flood potential assessment and mapping by integrating the weights-of-evidence and frequency ratio statistical methods in GIS environment – case study: Bâsca Chiojdului River catchment (Romania)

    Indian Academy of Sciences (India)

    Romulus Costache; Liliana Zaharia

    2017-06-01

    Given the significant worldwide human and economic losses caused due to floods annually, reducing the negative consequences of these hazards is a major concern in development strategies at different spatial scales. A basic step in flood risk management is identifying areas susceptible to flood occurrences. This paper proposes a methodology allowing the identification of areas with high potential of accelerated surface run-off and consequently, of flash-flood occurrences. The methodology involves assessment and mapping in GIS environment of flash flood potential index (FFPI), by integrating two statistical methods: frequency ratio and weights-of-evidence. The methodology was applied for Bâsca Chiojdului River catchment (340 km2), located in the Carpathians Curvature region (Romania). Firstly, the areas with torrential phenomena were identified and the main factors controlling the surface run-off were selected (in this study nine geographical factors were considered). Based on the features of the considered factors, many classes were set for each of them. In the next step, the weights of each class/category of the considered factors were determined, by identifying their spatial relationships with the presence or absence of torrential phenomena. Finally, the weights for each class/category of geographical factors were summarized in GIS, resulting the FFPI values for each of the two statistical methods. These values were divided into five classes of intensity and were mapped. The final results were used to estimate the flash-flood potential and also to identify the most susceptible areas to this phenomenon. Thus, the high and very high values of FFPI characterize more than one-third of the study catchment. The result validation was performed by (i) quantifying the rate of the number of pixels corresponding to the torrential phenomena considered for the study (training area) and for the results’ testing (validating area) and (ii) plotting the ROC (receiver operating

  8. Flash-flood potential assessment and mapping by integrating the weights-of-evidence and frequency ratio statistical methods in GIS environment - case study: Bâsca Chiojdului River catchment (Romania)

    Science.gov (United States)

    Costache, Romulus; Zaharia, Liliana

    2017-06-01

    Given the significant worldwide human and economic losses caused due to floods annually, reducing the negative consequences of these hazards is a major concern in development strategies at different spatial scales. A basic step in flood risk management is identifying areas susceptible to flood occurrences. This paper proposes a methodology allowing the identification of areas with high potential of accelerated surface run-off and consequently, of flash-flood occurrences. The methodology involves assessment and mapping in GIS environment of flash flood potential index (FFPI), by integrating two statistical methods: frequency ratio and weights-of-evidence. The methodology was applied for Bâsca Chiojdului River catchment (340 km2), located in the Carpathians Curvature region (Romania). Firstly, the areas with torrential phenomena were identified and the main factors controlling the surface run-off were selected (in this study nine geographical factors were considered). Based on the features of the considered factors, many classes were set for each of them. In the next step, the weights of each class/category of the considered factors were determined, by identifying their spatial relationships with the presence or absence of torrential phenomena. Finally, the weights for each class/category of geographical factors were summarized in GIS, resulting the FFPI values for each of the two statistical methods. These values were divided into five classes of intensity and were mapped. The final results were used to estimate the flash-flood potential and also to identify the most susceptible areas to this phenomenon. Thus, the high and very high values of FFPI characterize more than one-third of the study catchment. The result validation was performed by (i) quantifying the rate of the number of pixels corresponding to the torrential phenomena considered for the study (training area) and for the results' testing (validating area) and (ii) plotting the ROC (receiver operating

  9. Water-quality data and Escherichia coli predictions for selected karst catchments of the upper Duck River watershed in central Tennessee, 2007–10

    Science.gov (United States)

    Murphy, Jennifer; Farmer, James; Layton, Alice

    2016-06-13

    The U.S. Geological Survey, in cooperation with the Tennessee Duck River Development Agency, monitored water quality at several locations in the upper Duck River watershed between October 2007 and September 2010. Discrete water samples collected at 24 sites in the watershed were analyzed for water quality, and Escherichia coli (E. coli) and enterococci concentrations. Additional analyses, including the determination of anthropogenic-organic compounds, bacterial concentration of resuspended sediment, and bacterial-source tracking, were performed at a subset of sites. Continuous monitoring of streamflow, turbidity, and specific conductance was conducted at seven sites; a subset of sites also was monitored for water temperature and dissolved oxygen concentration. Multiple-regression models were developed to predict instantaneous E. coli concentrations and loads at sites with continuous monitoring. This data collection effort, along with the E. coli models and predictions, support analyses of the relations among land use, bacteria source and transport, and basin hydrology in the upper Duck River watershed.

  10. Impact of mineral fertility and bedrock erosion on single-mineral detrital studies: insights from trace-element and Nd-isotope systematics of detrital apatite from the Po River catchment

    Science.gov (United States)

    Malusa', Marco Giovanni; Wang, Jiangang; Garzanti, Eduardo; Villa, Igor M.; Wittman, Hella

    2017-04-01

    The detrital record provides an archive of mountain erosion that preserves key information for paleotectonic and paleoclimatic reconstructions. Detrital studies are often based on single-mineral analyses (e.g., geo/thermochronologic analyses on apatite and zircon). Their geologic interpretation can be challenging, because the impact of each eroding source on the detrital record is controlled by a range of factors including the rate of erosion and the fertility of chosen minerals in eroded bedrock. Here, we combine (i) a state-of-the art dataset of trace element and Nd isotope fingerprints of detrital apatite, (ii) a comprehensive dataset of apatite-fertility measurements (Malusà et al. 2016), (iii) fission-track data, and (iv) cosmogenic-derived erosion rates from the Po River catchment (Wittmann et al. 2016), to test the impact of mineral fertility and bedrock erosion on the single-mineral detrital signal preserved in the final sediment sink. Our results show that the information provided by accessory minerals, when complemented with accurate mineral fertility measurements, are fully consistent with information provided by the analysis of more abundant framework minerals. We found that trace element and Nd isotope analyses provide a reliable tool to disentangle the complex single-mineral record of orogenic erosion, and demonstrate that such a record is largely determined by high-fertility source rocks exposed within the drainage. Detrital thermochronology studies based on the lag-time approach should thus preferably include independent provenance discriminations and a full mineral fertility characterization of the potential source areas, in order to ensure a correct identification of the sediment sources and of the exogenic and endogenic processes monitored in the stratigraphic archive. Malusà M.G., Resentini A., Garzanti E., 2016. Hydraulic sorting and mineral fertility bias in detrital geochronology. Gondwana Res., 31, 1-19 Wittmann H., Malusà M.G., Resentini

  11. Water scarcity-induced change in vegetation cover along Teesta River catchments in Bangladesh : NDVI, Tasseled Cap and System dynamics analysis

    OpenAIRE

    Rahman, Md. Azizur

    2013-01-01

    Water scarcity is both natural and man-made phenomenon. Water control and uneven distribution of upstream TeestaRiver water makes artificial scarcity in downstream areas which can be minimized at least to the water stress level by balancing distribution and sustainable water use. Tasseled Cap transformation and NDVI methods were used in this study in order to find the magnitude of water scarcity in the downstream areas. NDVI and Tasseled Cap Greenness methods were applied to get proxy for soi...

  12. Water Pollution abatement programme, The Czech republic Pollution abatement analysis and strengthening of water resources management, Odra River Catchment, phase II

    OpenAIRE

    Dagestad, K.; Ratnaweera, H.; Ibrekk, H.O.; Hansen, J.H.; Tridlica, L.; Brezina, P.; Skacel, A.

    1995-01-01

    Odra river is extremely polluted by organic matter, nitrates, ammonia, phosphorus, bacteria, particles, heavy metals and other micro pollutants from municipalities, industries and agriculture. The poor water quality severely affects the ecology and represents a risk to human health. The water has a very limited value of use. This report presents an abatement programme with both technical and accompanying measures. In order to identify the major polluters several multi criteria analysis have b...

  13. Analysis of bio-obtainable endocrine disrupting metals in river water and sediment, sewage influent/effluent, sludge, leachate, and concentrated leachate, in the irish midlands shannon catchment.

    LENUS (Irish Health Repository)

    Reid, Antoinette M

    2009-01-01

    The application of an acid digestion and subsequent solid-phase extraction (SPE) procedure were implemented as preliminary treatments prior to quantifying the levels of potentially endocrine disrupting metals (EDMs) in a variety of solid and liquid matrices. These included (solid) river sediment, leachate sediment and sewage sludge and also (liquid) river water, landfill leachate, concentrated leachate, sewage influent, and sewage effluent, sampled in the Irish Midlands. The total concentrations of cobalt (Co), cadmium (Cd), copper (Cu), chromium (Cr), nickel (Ni), lead (Pb), zinc (Zn), and manganese (Mn), after extraction and preconcentration, were determined by atomic absorption spectroscopy (AAS). Mercury (Hg) in sediment and sludge was determined using cold-vapour atomic fluorescence spectroscopy (AFS). For sewage sludge maximum values (mg\\/kg(dw)) of 4700 Ni, 1642 Mn, 100.0 Cd, 3400 Zn, 36.70 Co, 750.0 Pb, 485.8 Cr, and 1003 Cu were determined whilst in leachate sediment, maximum values (mg\\/kg(dw)) of 32.10 Ni, 815.0 Mn, 32.78 Cd, 230.3 Zn, 26.73 Co, 3525 Pb, 124.9 Cr, and 50.13 Cu were found. Over several months, the data showed elevated levels in sewage influents, effluents, and sludges compared to a battery of adjacent river water samples and corresponding sediments. There was a definite trend for target values for sediments to be exceeded, while intervention values were only exceeded for cadmium. Overall the pattern in terms of concentration was sewage > leachate > river matrices. A nonparametric assessment of the effect of sewage treatment method on median metal levels in sludge revealed statistically significant differences at the 95% level of confidence for Co, Cr, and Hg and at the 90% level of confidence for Cd.

  14. Analysis of bio-obtainable endocrine disrupting metals in river water and sediment, sewage influent/effluent, sludge, leachate, and concentrated leachate, in the irish midlands shannon catchment.

    Science.gov (United States)

    Reid, Antoinette M; Brougham, Concepta A; Fogarty, Andrew M; Roche, James J

    2009-01-01

    The application of an acid digestion and subsequent solid-phase extraction (SPE) procedure were implemented as preliminary treatments prior to quantifying the levels of potentially endocrine disrupting metals (EDMs) in a variety of solid and liquid matrices. These included (solid) river sediment, leachate sediment and sewage sludge and also (liquid) river water, landfill leachate, concentrated leachate, sewage influent, and sewage effluent, sampled in the Irish Midlands. The total concentrations of cobalt (Co), cadmium (Cd), copper (Cu), chromium (Cr), nickel (Ni), lead (Pb), zinc (Zn), and manganese (Mn), after extraction and preconcentration, were determined by atomic absorption spectroscopy (AAS). Mercury (Hg) in sediment and sludge was determined using cold-vapour atomic fluorescence spectroscopy (AFS). For sewage sludge maximum values (mg/kg(dw)) of 4700 Ni, 1642 Mn, 100.0 Cd, 3400 Zn, 36.70 Co, 750.0 Pb, 485.8 Cr, and 1003 Cu were determined whilst in leachate sediment, maximum values (mg/kg(dw)) of 32.10 Ni, 815.0 Mn, 32.78 Cd, 230.3 Zn, 26.73 Co, 3525 Pb, 124.9 Cr, and 50.13 Cu were found. Over several months, the data showed elevated levels in sewage influents, effluents, and sludges compared to a battery of adjacent river water samples and corresponding sediments. There was a definite trend for target values for sediments to be exceeded, while intervention values were only exceeded for cadmium. Overall the pattern in terms of concentration was sewage > leachate > river matrices. A nonparametric assessment of the effect of sewage treatment method on median metal levels in sludge revealed statistically significant differences at the 95% level of confidence for Co, Cr, and Hg and at the 90% level of confidence for Cd.

  15. Analysis of Bio-Obtainable Endocrine Disrupting Metals in River Water and Sediment, Sewage Influent/Effluent, Sludge, Leachate, and Concentrated Leachate, in the Irish Midlands Shannon Catchment

    Directory of Open Access Journals (Sweden)

    Antoinette M. Reid

    2009-01-01

    Full Text Available The application of an acid digestion and subsequent solid-phase extraction (SPE procedure were implemented as preliminary treatments prior to quantifying the levels of potentially endocrine disrupting metals (EDMs in a variety of solid and liquid matrices. These included (solid river sediment, leachate sediment and sewage sludge and also (liquid river water, landfill leachate, concentrated leachate, sewage influent, and sewage effluent, sampled in the Irish Midlands. The total concentrations of cobalt (Co, cadmium (Cd, copper (Cu, chromium (Cr, nickel (Ni, lead (Pb, zinc (Zn, and manganese (Mn, after extraction and preconcentration, were determined by atomic absorption spectroscopy (AAS. Mercury (Hg in sediment and sludge was determined using cold-vapour atomic fluorescence spectroscopy (AFS. For sewage sludge maximum values (mg/kgdw of 4700 Ni, 1642 Mn, 100.0 Cd, 3400 Zn, 36.70 Co, 750.0 Pb, 485.8 Cr, and 1003 Cu were determined whilst in leachate sediment, maximum values (mg/kgdw of 32.10 Ni, 815.0 Mn, 32.78 Cd, 230.3 Zn, 26.73 Co, 3525 Pb, 124.9 Cr, and 50.13 Cu were found. Over several months, the data showed elevated levels in sewage influents, effluents, and sludges compared to a battery of adjacent river water samples and corresponding sediments. There was a definite trend for target values for sediments to be exceeded, while intervention values were only exceeded for cadmium. Overall the pattern in terms of concentration was sewage > leachate > river matrices. A nonparametric assessment of the effect of sewage treatment method on median metal levels in sludge revealed statistically significant differences at the 95% level of confidence for Co, Cr, and Hg and at the 90% level of confidence for Cd.

  16. THE IMPACT OF SEWAGE TREATMENT PLANT ON THE AMOUNT OF HEAVY METALS IN WATER OF THE SUPRAŚL RIVER CATCHMENT AREA

    Directory of Open Access Journals (Sweden)

    Mirosław Skorbiłowicz

    2016-01-01

    Full Text Available The main purpose of this study was to evaluate the effect of treated sewage flowing from sewage treatment plants located in the basin of the Supraśl river on the concentration and load of metals in river waters and its main tributaries. Three measuring- control points were chosen, on the river and its tributaries, located near Gródek, Sokółka and Dobrzyniewo. Selected points were located behind the discharge of treated wastewater from sewage treatment plants respectively – Gródek, Sokółka and Bialystok. The samples of treated sewage and water were collected in a period from May to November, once a month in 2014. Each individual sample was examined for the content of dissolved form of the following metals: Pb2+, Cu2+, Cd2+, Ni2+, Zn2+, Fe2+/3+. After taking into account water flow of the Biała, Sokołda and Supraśl in every month, metals loads expressed in mg·h-1, transported by the Supraśl and its tributaries waters were calculated. In the study monthly metals loads discharged into the Biała, Sokołda and Supraśl by sewage treatment plants in Białystok, Sokółka and Gródek were also calculated. The studies have shown the impact of metals load in treated wastewater on metals loads in waters of studied rivers based on the obtained correlation. Most of the searched relations between loafs of Pb2+ – r = 0,88; Cd2+ – r = 0,98; Fe2+/3+ – r = 0,45; Ni2+ – r = 0,55; Zn2+ – r = 0,86 were obtained in case of wastewater treatment plant in Gródek and Supraśl waters. In the study period we observed a diversity in concentration of Cd2+, Fe2+/3+, Ni2+ and Zn2+ in treated sewage and in river waters, which affected loads of this metals.

  17. Integrated flow and temperature modeling at the catchment scale

    DEFF Research Database (Denmark)

    Loinaz, Maria Christina; Davidsen, Hasse Kampp; Butts, Michael

    2013-01-01

    , the Silver Creek Basin in Idaho, where stream temperature affects the populations of fish and other aquatic organisms. The model calibration highlights the importance of spatially distributed flow dynamics in the catchment to accurately predict stream temperatures. The results also show the value...... Creek over 0.3°C and 1.5°C, respectively. In spring-fed systems like Silver Creek, it is clearly not feasible to separate river habitat restoration from upstream catchment and groundwater management....

  18. Using modified multiple phosphorus sensitivity indices for mitigation and management of phosphorus loads on a catchment level

    CSIR Research Space (South Africa)

    Oberholster, Paul J

    2013-01-01

    Full Text Available The relationships between river and lake phosphorus sensitivity, environmental drivers and catchment characteristics within the upper Olifants River and Lake Loskop were studied over a period of four years to come up with mitigation and management...

  19. Remote sensing of surface water quality in relation to catchment condition in Zimbabwe

    Science.gov (United States)

    Masocha, Mhosisi; Murwira, Amon; Magadza, Christopher H. D.; Hirji, Rafik; Dube, Timothy

    2017-08-01

    The degradation of river catchments is one of the most important contemporary environmental problems affecting water quality in tropical countries. In this study, we used remotely sensed Normalised Difference Vegetation Index (NDVI) to assess how catchment condition varies within and across river catchments in Zimbabwe. We then used non-linear regression to test whether catchment condition assessed using the NDVI is significantly (α = 0.05) related with levels of Total Suspended Solids (TSS) measured at different sampling points in thirty-two sub-catchments in Zimbabwe. The results showed a consistent negative curvilinear relationship between Landsat 8 derived NDVI and TSS measured across the catchments under study. In the drier catchments of the country, 98% of the variation in TSS is explained by NDVI, while in wetter catchments, 64% of the variation in TSS is explained by NDVI. Our results suggest that NDVI derived from free and readily available multispectral Landsat series data (Landsat 8) is a potential valuable tool for the rapid assessment of physical water quality in data poor catchments. Overall, the finding of this study underscores the usefulness of readily available satellite data for near-real time monitoring of the physical water quality at river catchment scale, especially in resource-constrained areas, such as the sub-Saharan Africa.

  20. Assessment of surface water resources availability using catchment modeling and the results of tracer studies in the meso-scale Migina Catchment, Rwanda

    NARCIS (Netherlands)

    Munyaneza, O.; Mukubwa, A.; Maskey, S.; Wenninger, J.W.; Uhlenbrook, S.

    2013-01-01

    In the last couple of years, different hydrological research projects were undertaken in the Migina catchment (243.2 km2), a tributary of the Kagera river in Southern Rwanda. These projects were aimed to understand hydrological processes of the catchment using analytical and experimental approaches

  1. Assessment of surface water resources availability using catchment modeling and the results of tracer studies in the meso-scale Migina Catchment, Rwanda

    NARCIS (Netherlands)

    Munyaneza, O.; Mukubwa, A.; Maskey, S.; Wenninger, J.W.; Uhlenbrook, S.

    2013-01-01

    In the last couple of years, different hydrological research projects were undertaken in the Migina catchment (243.2 km2), a tributary of the Kagera river in Southern Rwanda. These projects were aimed to understand hydrological processes of the catchment using analytical and experimental approaches

  2. Influence of anthropogenic inputs and a high-magnitude flood event on metal contamination pattern in surface bottom sediments from the Deba River urban catchment.

    Science.gov (United States)

    Martínez-Santos, Miren; Probst, Anne; García-García, Jon; Ruiz-Romera, Estilita

    2015-05-01

    The purpose of this study was to assess the influence of anthropogenic factors (infrastructure construction and industrial and wastewater inputs) and hydrological factors (high-magnitude flood events) on metal and organic contamination and on the source variability of sediments taken from the Deba River and its tributaries. The pollution status was evaluated using a sequential extraction procedure (BCR 701), enrichment factor, individual and global contamination factors and a number of statistical analysis methods. Zn, Cu and Cr were found to have significant input from anthropogenic sources, with moderately severe enrichment, together with an extremely high potential risk of contamination. The principal scavenger of Cu and Cr was organic matter, whereas Zn was uniformly distributed among all non-residual fractions. For Fe, the anthropogenic contribution was more obviously detected in bulk sediments (flood event resulted in a washout of the river bed and led to a general decrease in fine-grained sediment and metal concentrations in labile fractions of channel-bottom sediments, and a consequent downstream transfer of the pollution.

  3. Identifying fine sediment sources to alleviate flood risk caused by fine sediments through catchment connectivity analysis

    Science.gov (United States)

    Twohig, Sarah; Pattison, Ian; Sander, Graham

    2017-04-01

    Fine sediment poses a significant threat to UK river systems in terms of vegetation, aquatic habitats and morphology. Deposition of fine sediment onto the river bed reduces channel capacity resulting in decreased volume to contain high flow events. Once the in channel problem has been identified managers are under pressure to sustainably mitigate flood risk. With climate change and land use adaptations increasing future pressures on river catchments it is important to consider the connectivity of fine sediment throughout the river catchment and its influence on channel capacity, particularly in systems experiencing long term aggradation. Fine sediment erosion is a continuing concern in the River Eye, Leicestershire. The predominately rural catchment has a history of flooding within the town of Melton Mowbray. Fine sediment from agricultural fields has been identified as a major contributor of sediment delivery into the channel. Current mitigation measures are not sustainable or successful in preventing the continuum of sediment throughout the catchment. Identifying the potential sources and connections of fine sediment would provide insight into targeted catchment management. 'Sensitive Catchment Integrated Modelling Analysis Platforms' (SCIMAP) is a tool often used by UK catchment managers to identify potential sources and routes of sediment within a catchment. SCIMAP is a risk based model that combines hydrological (rainfall) and geomorphic controls (slope, land cover) to identify the risk of fine sediment being transported from source into the channel. A desktop version of SCIMAP was run for the River Eye at a catchment scale using 5m terrain, rainfall and land cover data. A series of SCIMAP model runs were conducted changing individual parameters to determine the sensitivity of the model. Climate Change prediction data for the catchment was used to identify potential areas of future connectivity and erosion risk for catchment managers. The results have been

  4. Comparison of direct outflow calculated by modified SCS-CN methods for mountainous and highland catchments in upper Vistula Basin, Poland and lowland catchment in South Carolina, U.S.A

    Science.gov (United States)

    A. Walega; A. Cupak; D.M. Amatya; E. Drozdzal

    2017-01-01

    The aim of the study is to compare direct outflow from storm events estimated using modifications of original SCS-CN procedure. The study was conducted in a mountainous catchment of Kamienica River and a highland catchment draining Stobnica River located in Upper Vistula water region, both in Poland, and a headwater lowland watershed WS80 located at the Santee...

  5. 巢湖流域丰乐河洪水事件营养盐输出动态研究%DYNAMIC EVOLUTION OF NUTRIENT EXPORT DURING FLOOD EVENTS FROM FENGLE RIVER CATCHMENT OF CHAO LAKE BASIN,CHINA

    Institute of Scientific and Technical Information of China (English)

    储茵; 潮洪武; 马友华; 郑珊珊; 潘应生

    2013-01-01

    洪水期是非点源污染输出的关键时期.通过对巢湖典型农业型流域丰乐河桃溪断面两次暴雨洪水过程(发生于2010年6月初的Event06和8月底的Event08)进行集中取样监测,结合该断面流量数据,分析了洪水过程中氮和磷营养盐不同指标(包括总氮、铵氮、硝态氮、总磷和可溶磷)浓度和瞬时负荷的动态变化规律.结果表明:Event06氮磷各指标浓度最小值、最大值及平均值均比Event08大,这与6月初农作物大量施肥,氮磷来源丰富有很大关系.丰乐河洪水事件氮输出的形式以可溶性无机氮(铵氮和硝态氮)为主,而磷则以颗粒态为主,但在涨水段的初、中期颗粒态氮和颗粒态磷所占比例比其它时段高.洪水过程中主要氮、磷指标浓度和瞬时负荷随流量增大而总体呈上升趋势(除了硝态氮),在流量峰值前达到最大值,然后呈总体下降趋势.总磷、总氮浓度与流量呈比较典型的顺时针圈形结构,表明暴雨洪水较强烈的冲刷输送作用.虽然进一步的负荷累积分析并没有显示显著的初期冲刷效应,但洪水期,特别是涨水段营养盐输出的重要性已较明显.丰乐河流域面积较大、地势较平坦,以农业活动为主,水体污染的非点源来源与农业活动有关,具体的洪水过程对营养盐的输出动态也有一定影响.%Non-point source pollutants are mainly transported during flood events.The Fengle River,one of the main tributaries of the Chao Lake in the middle-east part of China,was chosen to study non-point source nutrient export characteristics in a large-sized agricultural catchment.Two summer events (Event06,in the beginning of June and Event08,at the end of August,2010) were intensively sampled at Taoxi section of the river and analyzed for Total Nitrogen (TN),Ammonia,Nitrate,Total Phosphorus (TP) and Dissolved Phosphorus.Hourly discharge and rainfall data were also available at the same section.The drainage

  6. Diatoms as a fingerprint of sub-catchment contributions to meso-scale catchment runoff

    Science.gov (United States)

    Klaus, Julian; Wetzel, Carlos E.; Martinez-Carreras, Nuria; Ector, Luc; Pfister, Laurent

    2014-05-01

    In recent years, calls were made for new eco-hydrological approaches to improve understanding of hydrological processes. Recently diatoms, one of the most common and diverse algal groups that can be easily transported by flowing water due to their small size (~10-200 µm), were used to detect the onset and cessation of surface runoff to small headwater streams and constrain isotopic and hydro-chemical hydrograph separation methods. While the method showed its potential in the hillslope-riparian zone-stream continuum of headwater catchments, the behavior of diatoms and their use for hydrological process research in meso-scale catchments remains uncertain. Diatoms can be a valuable support for isotope and hydro-chemical tracer methods when these become ambiguous with increasing scale. Distribution and abundance of diatom species is controlled by various environmental factors (pH, soil type, moisture conditions, exposition to sunlight, etc.). We therefore hypothesize that species abundance and composition can be used as a proxy for source areas. This presentation evaluates the potential for diatoms to trace source-areas in the nested meso-scale Attert River basin (250 km2, Luxembourg, Europe). We sampled diatom populations in streamwater during one flood event in Fall 2011 in 6 sub-catchments and the basin outlet - 17 to 28 samples/catchment for the different sampling locations. Diatoms were classified and counted in every individual sample. In total more than 400 diatom species were detected. Ordination analysis revealed a clear distinction between communities sampled in different sub-catchments. The species composition at the catchment outlet reflects a mixing of the diatom composition originating from different sub-catchments. This data suggests that diatoms indeed can reflect the geographic origin of stream water at the catchment outlet. The centroids of the ordination analysis might be linked to the physiographic characteristics (geology and land use) of the

  7. Characterizing streamflow generation in Alpine catchments

    Science.gov (United States)

    Chiogna, Gabriele; Cano Paoli, Karina; Bellin, Alberto

    2016-04-01

    Developing effective hydrological models for streamflow generation in Alpine catchments is challenging due to the inherent complexity of the intertwined processes controlling water transfer from hillslopes to streams and along the river network. With water discharge as the sole observational variable it is impossible to differentiate between different streamflow sources, and modelling activity is often limited to simplified phenomenological rainfall-runoff models. This study focuses on quantifying streamflow sources at different temporal scales and the associated uncertainty by using natural tracer data (electrical conductivity, oxygen and hydrogen stable isotopes ratios) as observational variables supplementing streamflow measurements. We determine the spatial and temporal hydrological behavior and the mean residence time of water in the Vermigliana catchment, North-Eastern Italy and we separate contributions to streamflow originating from Presena and Presanella glaciers, both exerting a strong control on the hydrologic budget of the study site. Furthermore, we identify a seasonal control on the effect of storm events. The catchment responded rapidly to precipitation events in early autumn, it was unaffected by precipitation events in early spring, while runoff generation was enhanced by snow melting in late autumn. Air temperature is identified as the main controlling parameter, in addition to precipitation. Two-component mixing analysis showed that the relative contribution of new water, which can contribute up to 75% of total streamflow, is very rapid. Only two hours time-lag was observed between the beginning of the precipitation event and the emergence of a significant contribution of new water. These results evidence the relevance of mixing between pre-event and event water in the Vermigliana catchment, and in similar high elevation Alpine catchments. This study provides new insights on the dynamics of streamflow generation in Alpine catchments and a

  8. Seasonal Variations in δ18O of Inflowing River Water, Lake Water, Sediment Trap Material and Ostracod Shells of Lake Nam Co and its Catchment (Tibet, China) — a Proxy Calibration Study

    Science.gov (United States)

    Daut, G.; Wang, J.; Ju, J.; Plessen, B.; Fürstenberg, S.; Baade, J.; Frenzel, P.; Haberzettl, T.; Maeusbacher, R.; Zhu, L.

    2014-12-01

    δ18O is a very common proxy used in palaeoclimate studies all over the world, but for most parts of the world and especially the Tibetan Plateau modern studies that trace the pathway of this isotope from sink to source are lacking. In this study, financed by the BMBF (German Ministry of Science and Education, Project CADY), we present data that fill this gap. The study was performed in the terminal lake Nam Co, the biggest lake on the central Tibetan Plateau and its catchment. Water of the main tributaries to the lake, lake water at three different stations and from different water depths, bulk carbonate collected from different water depths with sediment traps and shells of living ostracods were collected for one year at lake Nam Co in approx. monthly intervals and analyzed for their δ18O values. The inflowing river waters mainly reflect the precipitation and show regional as well as seasonal variations depending on their location and on Monsoon or Westerly season but are in general on the global meteoric waterline. The lake water shows only minor vertical and spatial variations and is clearly off the meteoric waterline due to strong evaporation effects in this terminal lake. δ18O values of the bulk carbonate of sediment collected in sediment traps show only minor vertical and spatial variations during the year and the δ18O offset compared to the lake water is with around 1 ‰ quite small. Most probably this is attributed to chemical fractionation during formation of monohydrocalcite in the water column. In contrast δ18O values of ostracod shells are significant heavier than the lake water indicating isotopic fractionation (vital effect) during shell formation. In addition a seasonal variability is visible. The data of this proxy calibration study give now for the first time the opportunity to validate δ18O proxy data measured on core material from Lake Nam Co for their palaeoclimatic significance.

  9. Understanding bioavailability and toxicity of sediment-associated contaminants by combining passive sampling with in vitro bioassays in an urban river catchment.

    Science.gov (United States)

    Li, Juan-Ying; Tang, Janet Yat Man; Jin, Ling; Escher, Beate I

    2013-12-01

    Bioavailable and bioaccessible fractions of sediment-associated contaminants are considered as better dose metrics for sediment-quality assessment than total concentrations. The authors applied exhaustive solvent extraction and nondepletive equilibrium sampling techniques to sediment samples collected along the Brisbane River in South East Queensland, Australia, which range from pristine environments to urban and industry-impacted areas. The wide range of chemicals expected prevents comprehensive chemical analysis, but a battery of cell-based bioassays sheds light on mixture effects of chemicals in relation to various modes of toxic action. Toxic effects were expressed as bioanalytical equivalent concentrations (BEQs) normalized to the organic carbon content of each sediment sample. Bioanalytical equivalent concentrations from exhaustive extraction agreed fairly well with values estimated from polydimethylsiloxane passive sampling extracts via the constant organic carbon to polydimethylsiloxane partition coefficient. Agreement was best for bioassays indicative of photosynthesis inhibition and oxidative stress response and discrepancy within a factor of 3 for the induction of the aryl hydrocarbon receptor. For nonspecific cytotoxicity, BEQ from exhaustive extraction were 1 order of magnitude higher than values from equilibrium sampling, possibly because of coextraction of bioactive natural organic matter that led to an overestimation of toxicity in the exhaustive extracts, which suggests that passive sampling is better suited in combination with bioanalytical assessment than exhaustive extraction.

  10. GEODIVERSITY AUDIT AND ACTION PLAN FOR UPPER CATCHMENT AREA OF GERSA RIVER (RODNEI MOUNTAINS, BISTRIȚA-NĂSĂUD COUNTY, ROMANIA

    Directory of Open Access Journals (Sweden)

    Ioan Bâca

    2015-08-01

    Full Text Available Geodiversity Audit is an inventory and assessment process, wich represents the basis for elaborating the Geoconservation Action Plan. The geodiversity includes the abiotic factors (rocks, minerals, soils, landforms that sustain the life on the Earth, and owns economic, social, environmental, tourist and educational functions. This study proposes an audit of geodiversity from Gersa catcment area and an Action Plan for future planning and tourist valorization projects by local and county authorities. Gersa Valley is a geomorphological subunit located in the southern part of Rodnei Mountains (Bistrița-Năsăud County and contains in the superior sector some landforms with high degree of attractiveness, such as Izvorul Tăușoarelor Cave, Izvorul Calului Gorge and Bârlea Massif. By their configuration these landforms has a great potential for engaging in scientific and recreational activities (caving, hiking, gorge walking, canyoning, mountain biking. Keywords: geodiversity, geologic heritage, geoconservation, geosite, action plan, Rodnei Mountains, Gersa River, Izvorul Tăușoarelor Cave, speotourism, activ leisure

  11. THE CONTENT OF HEAVY METALS IN BOTTOM SEDIMENTS OF THE WATERCOURSE IN AGRICULTURAL CATCHMENT ON THE EXAMPLE OF THE RIVER GOWIENICA

    Directory of Open Access Journals (Sweden)

    Kamil Szydłowski

    2017-08-01

    Full Text Available Bottom sediments samples for chemical analysis were derived from Gowienica river and its tributaries. Samples were taken at 2014 and 2015 years from established sampling points on differently managed and utilized adjacent areas. Total content of heavy metals, i.e.: Cd, Co, Cr, Ni, Pb and Hg were measured in collected material. The results indicate that concentrations of lead, nickel, chromium and mercury exceeded level below which no harmful impact of pollution (TEL is noted, but none of the analyzed heavy metals exceeded the limit (PEL above which harmful effects of pollution on organisms can be observed. However, according to other classification (LAW analyzed sediments were located between two classes (deposits unpolluted - Class I, and deposits unpolluted / moderately polluted (class I-II. However, chemical analysis showed the various points exceeded the natural cobalt concentration (geochemical background; 2.0 mg⋅kg-1 for aquatic sediments in Poland. The reasons of cobalt concentration exceedance in natural sediments, among others, were surface runoff from fields and meadows in the form of fertilizers, plant protection products and the domestic waste water.

  12. Radionuclide Data and Calculations and Loss-On-Ignition, X-Ray Fluorescence, and ICP-AES Data from Cores in Catchments of the Animas River, Colorado

    Science.gov (United States)

    Church, Stanley E.; Rice, Cyndi A.; Marot, Marci E.

    2008-01-01

    The U.S. Departments of Agriculture and Interior Abandoned Mine Lands (AML) Initiative is focused on the evaluation of the effect of past mining practices on the water quality and the riparian and aquatic habitats of impacted stream reaches downstream from historical mining districts located primarily on Federal lands. This problem is manifest in the eleven western states (west of longitude 102 degrees) where the majority of hardrock mines that had past production are located on Federal lands. In areas of temperate climate and moderate to heavy precipitation, the effects of rapid chemical and physical weathering of sulfides exposed on mine-waste dumps and acidic drainage from mines have resulted in elevated metal concentrations in the stream water and stream-bed sediment. The result of these mineral weathering processes has an unquantified impact on the quality of the water and the aquatic and riparian habitats that may limit their recreational resource value. One of the confounding factors in these studies is the determination of the component of metals derived from hydrothermally altered but unmined portions of these drainage basins. Several watersheds have been studied to evaluate the effects of acid mine drainage and acid rock drainage on the near-surface environment. The Animas River watershed in southwestern Colorado contains a large number of past-producing metal mines that have affected the watershed. Beginning in October 1996, the U.S. Geological Survey (USGS) began a collaborative study of these effects under the USGS-AML Initiative. In this report, we present the radionuclide and geochemical analytical results of sediment coring during 1997-1999 from two cores from oxbow lakes 0.5 mi. upstream from the 32nd Street Bridge near Durango, Colo., and from three cores from beaver ponds within the Mineral Creek drainage basin near Silverton, Colo.

  13. A Treatment Train Approach To Catchment Management

    Science.gov (United States)

    Barber, Nick; Quinn, Paul; Org, EdenDTC