RecentPapersonSedimentTransport
Content Table
- Case study of a large summer flood on the North Slope of Alaska: bedload transport
- Estimation of uncertainty in long term combined sewer sediment behaviour predictions, a UK case study
- The reliability of sediment transport predictions in sewers: influence of hydraulic and morphological uncertainties
- Use of complete gamma function in accurate evaluation of Einstein integrals
- Historic sediment accumulation rates in Karlskärsviken, a bay of Lake Mälaren, Sweden
- Assessment of uncertainty in Great Barrier Reef catchment models
- Sediment transport to the Arctic Ocean and adjoining cold oceans*
- Influence of climate warming on Hálslón Reservoir sediment filling
- Critical bed shear for initial movement of sediments on a combined lateral and longitudinal slope
- First evaluation of new design concepts for self-cleaning distribution networks
Case study of a large summer flood on the North Slope of Alaska: bedload transport
Hydrology Research Vol 39 No 4 pp 299–308 © IWA Publishing 2008 doi:10.2166/nh.2008.006
J. P. McNamara, J. A. Oatley, D. L. Kane and L. D. Hinzman
Department of Geosciences, Boise State University, 1910 University Dr., MG 121, Boise, ID 83725, USA Tel.: +1 208 426 1354 E-mail: jmcnamar@boisestate.edu
Water and Environmental Research Center, University of Alaska Fairbanks, Fairbanks, AK 99775, USA
Abstract
The relative importance of snowmelt versus rain-generated floods on sediment transport in arctic streams is largely unknown because studies documenting either event-type are rare. An August 2002 precipitation event produced the largest discharge level (snowmelt or rain) over the previous ten-year period of hydrologic and geomorphologic monitoring in the Upper Kuparuk River, Alaska providing an opportunity to document the geomorphologic response to of an arctic stream to an extreme event. In this study we document the geomorphologic response and estimate the bedload transport rate using the virtual velocity method. This flood mobilized virtually the entire bed, with the exception of random boulders greater than 0.5 m. The channel cross-section and water edge survey data illustrate the considerable morphologic response generated by the flood. The magnitude of this response resulted in only a 13% tracer rock recovery rate. The total bedload transport was estimated to be 870 m3 of bed material through the study cross sections. Channel morphology, and therefore habitat, is maintained by large and infrequent summer rain events. These events, particularly when they occur in the late summer months, when active layer depth is at its greatest, have the potential to generate orders of magnitude more bedload transport than a snowmelt runoff event. It is unclear, however, if the lack of significant bedload transport during snowmelt is due to protection by bedfast ice or if flows are insufficient.
Estimation of uncertainty in long term combined sewer sediment behaviour predictions, a UK case study
Water Science & Technology—WST Vol 57 No 9 pp 1405–1411 © IWA Publishing 2008 doi:10.2166/wst.2008.299
A. N. A. Schellart, R. M. Ashley, F. A. Buijs and S. J. Tait
Pennine Water Group, Department of Civil & Structural Engineering, University of Sheffield, Mappin Street, Sheffield, S1 3JD, UK E-mail: a.schellart@sheffield.ac.uk
School of Civil Engineering and Geosciences, University of Newcastle-Upon-Tyne/Visiting Researcher HR Wallingford, Howbery Park, Wallingford, Oxfordshire , OX10 8 BA, UK
Pennine Water Group, School of Engineering Design and Technology, University of Bradford, Bradford, BD7 1DP, UK
Abstract
There are regulatory driven requirements for UK water companies to reduce the number of properties at risk of sewer flooding. One of the potential causes of sewer flooding is the presence of persistent sediment deposits in sewers. This is a common problem in many combined sewers. Although the regulation is risk based, there is a gap in current knowledge on how risk assessment is affected by the uncertainty in sewer solids behaviour prediction. This paper describes a UK case study exploring the possibility of estimating uncertainty in sewer sediment deposit level predictions, using Monte Carlo simulations combined with a response database.
The reliability of sediment transport predictions in sewers: influence of hydraulic and morphological uncertainties
Water Science & Technology—WST Vol 57 No 9 pp 1317–1327 © IWA Publishing 2008 doi:10.2166/wst.2008.297
Robert Banasiak and Simon Tait
Hydraulics Laboratory, Ghent University, Sint-Pietersnieuwstraat 41, 9000, Ghent, Belgium robert.banasiak@ugent.be
Department of Civil and Structural Engineering, University of Bradford, BD7 1DP, UK s.tait@bradford.ac.uk
Abstract
The paper is focussed on the concept of defining the “predictability” of sediment transport. Engineers are faced with a number of sediment transport formulas derived from different tests and described as suitable for application in sewers. Bed and suspended load formulas vary in form and performance, generally depending on the data sets that were used to calibrated them. As different sediment types have been tested no single, generally valid formula has been established so far. Formulas are distributed in the scientific literature and are often reported without the information necessary to define their range of potential applicability. Therefore, this paper along with analysing the formulas available, will also comment on the assumptions used in their development as well as the reliability of their underlying data to aid engineers in the selection of the most appropriate sediment transport formulae to correspond with the environment in which they are working.
Use of complete gamma function in accurate evaluation of Einstein integrals
Hydrology Research Vol 39 No 3 pp 223–227 © IWA Publishing 2008 doi:10.2166/nh.2008.042
I. I. Guseinov and B. A. Mamedov
Department of Physics, Faculty of Arts and Sciences, Onsekiz Mart University, Çanakkale, Turkey Tel.: 00903562521585; Fax: 00903562521582 E-mail: isguseinov@yahoo.com
Department of Physics, Faculty of Arts and Sciences, Gaziosmanpasa University, Tokat, Turkey
Abstract
By the use of the binomial expansion theorem, the series expansion relations in terms of the complete gamma function are obtained for Einstein integrals arising in the hydraulic and modern sediment transport mechanics. The approach presented for Einstein integrals is accurate enough over the whole range of parameters. The computational time for calculation of the series with respect to the literature is fast. Furthermore, the comparison of the method with numerical calculations demonstrates the applicability and accuracy of the method.
Keywords: bed load; binomial coefficients; complete gamma function; sediment transport; suspended load
Historic sediment accumulation rates in Karlskärsviken, a bay of Lake Mälaren, Sweden
Hydrology Research Vol 39 No 2 pp 123–132 © IWA Publishing 2008 doi:10.2166/nh.2008.032
Gull Olli
Department of Physical Geography and Quaternary Geology, Stockholm University, SE-10691, Stockholm, Sweden gull.olli@natgeo.su.se
Abstract
Historic sediment accumulation rate development was investigated in Karlskärsviken, a bay of Lake Mälaren, by dating of sediments in cores taken from the bay. The Lake Mälaren transition period from brackish water to freshwater was determined by diatom analysis and for modern times by fly-ash (SCP) and caesium isotope Cs-137 analyses. Results show that in the long period from medieval times to about 1950, the sediment accumulation rate increased to about double in the outer section of the bay, but only by about 33% in the near shore. After that, new farmland was drained by a ditch dug in 1951 with its outlet in Karlskärsviken, which enlarged the bay catchment area by 100%, and a marina and a public beach were constructed in 1953. These catchment system changes increased considerably the inflow of particles to Karlskärsviken and the sediment accumulation in the bay, directly and mostly in the near shore, but also with some and longer term effects further out in the bay. In later times, as the ditch became overgrown by reeds and bushes, the sedimentation rate decreased again in the near shore, while it continued to increase further out in the bay. These results indicate that even relatively small and common catchment enterprises may considerably affect sediment transport to recipient bay waters.
Assessment of uncertainty in Great Barrier Reef catchment models
Water Science & Technology Vol 56 No 1 pp 181–188 © CSIRO 2007 doi:10.2166/wst.2007.450
A. Herr* and P.M. Kuhnert**
Abstract
This paper addresses uncertainty in socio-economic and sediment-nutrient models that are being developed for the assessment of change in the Great Barrier Reef (GBR) area. The catchments draining into the GBR lagoon are sources of pollutants. The Reef Water Quality Management Plan of the Queensland Government identified sediments and nutrients transported to the GBR lagoon as the major long-term threats to the reef and inshore ecosystems and the wellbeing of the human communities. The plan clearly indicates that changes in land management are required by 2013 to reduce pollutant inputs and, at the same time, maintain or enhance the benefits from using the inland waters. Science that provides decision tools for natural resource management and improves socio-economic and biophysical understanding is required to enable managers to make better decisions. A major research activity (the Water for a Healthy Country Flagship) aims to address social, economic and biophysical outcomes of land management change in the GBR. It contains research activities that provide information for integrated model development. Currently, however, these models lack the ability to estimate the uncertainty associated with prediction. This project aims to provide statistical methods for assessing uncertainty in models of sediment transportation to the GBR. Furthermore, it provides a link between the models and the decision-making process that allows assessment of uncertainty, a step pertinent to the risk analysis of policy options. This paper describes current and ongoing approaches for assessing uncertainty using a sediment modelling example and provides a way forward for the integration of applied socio-economic and biophysical models used in the decision-making process.
Sediment transport to the Arctic Ocean and adjoining cold oceans*
Nordic Hydrology Vol 37 No 4-5 pp 413–432 © IWA Publishing 2006 doi:10.2166/nh.2006.023
Bent Hasholt1, Nelly Bobrovitskaya2, Jim Bogen3, James McNamara4, Sebastian H. Mernild1, David Milburn5 and Desmond E. Walling6
1Institute of Geography, University of Copenhagen, Øster Voldgade 10, DK-1350 Copenhagen, K, Denmark. bh@geogr.ku.dk
2State Hydrologic Institute, St. Petersburg, , Russia
3Norwegian Water Resources and Energy Directorate, Oslo, Norway
4Department of Geosciences, Boise State University, Boise, ID 83725, USA
5Water Resources Division, Department of Indian Affairs and Northern Development, Yellowknife, , Northwest Territories, X1A 2R3, Canada
6Department of Geography, University of Exeter, Exeter, Essex, EX4 4RJ, UK
Abstract
This paper reviews and synthesises available information on sediment transport to the Arctic Ocean and adjoining seas with open contact to the Atlantic and Pacific Oceans. Special emphasis is placed on calculation and estimation of the sediment flux from the mostly ungauged high Arctic areas on the American continent, in Greenland, and on islands in the Arctic Ocean, and from Russia. In the absence of reliable information on bedload fluxes for most rivers, attention is directed primarily to suspended sediment loads. By combining available monitoring data and estimates for ungauged areas, the total sediment transport to the Arctic Ocean is estimated to be 324–884 × 106 t yr-1. Of this total, a maximum of about 56% can be considered as monitored, while the rest is based on different types of estimate. It is clearly demonstrated that the monitoring network in the high Arctic is inadequate and that there is a lack of knowledge concerning the proportion of the load that actually reaches the sea, as well as bedload.
Influence of climate warming on Hálslón Reservoir sediment filling
Nordic Hydrology Vol 37 No 3 pp 235–245 © IWA Publishing 2006 doi:10.2166/nh.2006.014
Sigurdur Magnus Gardarsson* and Jonas Eliasson
University of Iceland, Engineering Research Institute, Department of Environmental and Civil Engineering, Hjardarhagi 6, IS-107 Reykjavik, Iceland. *Corresponding author. sigmg@hi.is
Abstract
Hálslón reservoir is the main reservoir of the Kárahnjúkar hydropower project in the eastern highlands of Iceland. Studies for the environmental impact assessment for the hydropower project showed that sediment will fill the reservoir in about 500 years based on the present sediment transport rate. The main source of the sediment is the Brúarjökull outlet glacier which is a part of the Vatnajökull ice cap. Recent studies of the influence of climate warming on glaciers in Iceland show that they will decrease significantly and, in some cases, completely disappear during the next few hundred years. In this study, a glacier melt model for the Brúarjökull outlet glacier is constructed to predict how fast the glacier will retreat in response to accepted climate warming scenarios. The results from the glacier model are then used as input to a sediment transport mass balance model for the Hálslón reservoir, which predicts the influence of the retreat of the glacier on the sedimentation in the reservoir. The modeling shows that, instead of the reservoir being completely full of sediment in 500 years, the Hálslón reservoir will at that time still have about 50–60% of its original volume as the sediment yield will decrease as a result of the decreasing glacier size.
Critical bed shear for initial movement of sediments on a combined lateral and longitudinal slope
Nordic Hydrology 35 2 (2004) 153-164
Subhasish Dey
Associate Professor, Department of Civil Engineering, Indian Institute of Technology, Kharagpur 721302, West Bengal, India
Abstract
An experimental study on critical bed shear-stress for initial movement of non-cohesive sediment particles under a steady-uniform stream flow on a combined lateral (across the flow direction) and longitudinal (streamwise direction) sloping bed is presented. The aim of this paper is to ascertain that the critical bed shear-stress on a combined lateral and longitudinal sloping bed is adequately represented by the product of critical bed shear-stress ratios for lateral and longitudinal sloping beds. Experiments were carried out with closed-conduit flow, in two ducts having a semicircular invert section, with three sizes of sediments. In laboratory flumes, the uniform flow is a difficult – if not impossible - proposition for a steeply sloping channel, and is impossible to obtain in an adversely sloping channel. To avoid this problem, the experiments were conducted with a closed-conduit flow. The critical bed shear-stresses for experimental runs were estimated from side-wall correction. The experimental data agree satisfactorily with the results obtained from the proposed formula. Keywords Sediment transport; sediment threshold; sediment motion; open channel flow; steady flow; fluvial hydraulics
First evaluation of new design concepts for self-cleaning distribution networks
J Water SRT - Aqua 53 (2004) 43-50
M. van den Boomen, A. van Mazijk and R. H. S. Beuken
Kiwa Water Research, Groningenhaven 7, PO Box 1072, 3430 BB Nieuwegein, The Netherlands Tel: +31 (0)30 6069 756 Fax: +31 (0)30 6061 165 E-mail: martine.van.den.boomen@kiwa.nl
Delft University of Technology, Faculty of Civil Engineering & Geosciences, Section of Water Management, Stevinweg 1, PO Box 5048, 2600 GA Delft, The Netherlands Tel: +31 (0)15 278 54 77 Fax: +31 (0)15 278 59 15 E-mail: a.van.mazijk@CiTG.TUDelft.nl
Kiwa Water Research, Groningenhaven 7, PO Box 1072, 3430 BB Nieuwegein, The Netherlands Tel: +31 (0)30 6069 756 Fax: +31 (0)30 6061 165 E-mail: ralph.beuken@kiwa.nl
Abstract
Ten years of joint research on the nature and causes of discoloured water has resulted in guidelines for the implementation of self-cleaning distribution networks. These were first introduced in the Netherlands in 1999. The self-cleaning concept has been monitored right from its beginnings. Based on this evaluation, significant observations were found on the contribution of changes in flow velocity to the self-cleaning characteristics of pipes. These observations will be further investigated and will form the basis for the concept of dynamic sediment transportation modelling.
