A method to measure suspended load transports in estuaries

Krause, Günther; Ohm, K.

doi:10.1016/0272-7714(84)90018-0

Cited by 18 publications

(6 citation statements)

References 6 publications

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“…3b; Table 1), which is similar to that obtained at an oceanic to coastal water gradient in the Gulf of Mexico (Gould and Arnone 1997), and also similar to the range observed in nine NZ estuaries (1.3-5.2 m −1 ; Vant 1990). The present specific SPMT particle beam attenuation coefficient (c p * ) of 0.80 m 2 g −1 SPMT was about two times higher as compared to literature values from different turbid estuaries: 0.44 m 2 g −1 SPM (Krause and Ohm 1984), 0.4 m 2 g −1 SPM (Vant 1990), and 0.55 m 2 g −1 SPM (Wells and Kim 1991). There is a record of a similar (0.81 m 2 g −1 SPM) and high specific attenuation coefficient from the Lena River entering the Kara Sea (Vasilkov et al 1999).…”

Section: Discussionmentioning

confidence: 44%

Suspended Matter, Chl-a, CDOM, Grain Sizes, and Optical Properties in the Arctic Fjord-Type Estuary, Kangerlussuaq, West Greenland During Summer

Lund-Hansen

Andersen

Nielsen

et al. 2010

Estuaries and Coasts

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Optical constituents as suspended particulate matter (SPM), chlorophyll (Chl-a), colored dissolved organic matter (CDOM), and grain sizes were obtained on a transect in the arctic fjord-type estuary Kangerlussuaq (66°) in August 2007 along with optical properties. These comprised diffuse attenuation coefficient of downwelling PAR (K d (PAR)), upwelling PAR (K u (PAR)), particle beam attenuation coefficient (c p ), and irradiance reflectance R (−0, PAR). PAR is white light between 400 and 700 nm. The estuary receives melt water from the Greenland Inland Ice and stations covered a transect from the very high turbid melt water outlet to clear marine waters. Results showed a strong spatial variation with high values as for suspended matter concentrations, CDOM, diffuse attenuation coefficient K d (PAR), particle beam attenuation coefficients (c p ), and reflectance R(−0, PAR) at the melt water outlet. Values of optical constituents and properties decreased with distance from the melt water outlet to a more or less constant level in central and outer part of the estuary. There was a strong correlation between inorganic suspended matter (SPMI) and diffuse attenuation coefficient K d (PAR) (r 2 = 0.92) and also for particle beam attenuation coefficient (c p ; r 2 =0.93). The obtained SPMI specific attenuation-K d * (PAR)=0.13 m 2 g −1 SPMI-and the SPMI specific particle beam attenuation-c p * = 0.72 m 2 g −1 -coefficients were about two times higher than average literature values. Irradiance reflectance R(−0, PAR) was comparatively high (0.09−0.20) and showed a high (r 2 = 0.80) correlation with K u (PAR). Scattering dominated relative to absorption-b(PAR)/a(PAR)=12.3. Results strongly indicated that the high values in the optical properties were related to the very fine particle sizes (mean=2-6 μm) of the suspended sediment. Data and results are discussed and compared to similar studies from both temperate and tropical estuaries.

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Section: Discussionmentioning

confidence: 44%

Suspended Matter, Chl-a, CDOM, Grain Sizes, and Optical Properties in the Arctic Fjord-Type Estuary, Kangerlussuaq, West Greenland During Summer

Lund-Hansen

Andersen

Nielsen

et al. 2010

Estuaries and Coasts

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“…Walling (1977) found such a close relationship between turbidity and suspended solids concentration that he used continuous turbidity records to define the 'true' sediment load. By using regular calibration with the gravimetric method, Krause and Ohm (1984) used turbidity measurements to estimate the sediment load in an estuary to within f12%.…”

Section: Potential Of Turbidimetric Monitoring Of Suspended Solids Trmentioning

confidence: 99%

Potential of turbidity monitoring for measuring the transport of suspended solids in streams

Gippel

1995

Hydrological Processes

296

239

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Investigating the transport of suspended solids by water sampling usually leads to an underestimation of loads and an unrealistically high sampling frequency is required to properly characterize temporal trends. An alternative method is to use in situ optical turbidimeters to estimate the suspended solids concentration; however, the relationship between turbidity and suspended solids concentration is potentially confounded by variations in particle size, particle composition and water colour. Field measurements, and laboratory measurements using the type of natural material suspended in streamwater, were made to quantify the influences of these factors on nephelometric turbidity (Hach 2100A) and attenuance turbidity (Partech 7000 3Rp MKII). The attenuance turbidity was approximately 2.5 times higher than nephelometric turbidity. The turbidity instruments were most sensitive to dispersions with a median diameter of 1.2-1.4pm. Particle size variation can cause the turbidity to vary by a factor of four for the same concentration of suspended solids. However, the numerous close correlations between turbidity and suspended solids concentration reported previously suggests that either the particle size variations are not usually great, or that particle size variations are often associated with variations in suspended solids concentration. For the same concentration and particle size, organic particles gave attenuance turbidity values two to three times higher than mineral particles. However, shortterm temporal variations from purely organic to purely mineral particle loads are rare in nature, so variations in the percentage of organic matter in the particulate load will not confound turbidity to this extent. Coloured dissolved organic matter is unlikely to alter the turbidity reading by more than 10%. An adequate relationship between turbidity measured in the field and suspended solids concentration should be expected in most situations. Some variance can be tolerated because a continuous estimate of suspended solids concentration overcomes the problem of infrequent sampling, which is the greatest source of error in the estimation of stream sediment loads.

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“…An Aanderaa current meter with turbidity sensor is maintained there permanently at a sampling rate of (in general) 10 min At present, only optical methods have the potential to cover the necessary wide range of the spectrum of variability of the suspended matter transport. Krause and Ohm [1984] described a method that provides time series of suspended matter transports in estuaries based on an optical beam transmittance meter [Ohm, 1979]…”

Section: The Weser Estuarymentioning

confidence: 99%

Transport processes of suspended matter derived from time series in a tidal estuary

Grabemann¹,

Krause²

1989

J. Geophys. Res.

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Optical beam transmittance meters integrated into Aanderaa current meters were used to measure long time series of suspended matter concentration simultaneously with current velocity and salinity in the turbidity maximum of the Weser estuary (shallow coastal plain estuary of the North Sea). They cover the spectrum from 10 min to several months. The time histories of concentrations and fluxes are discussed for characteristic locations within the turbidity maximum. The analyses demonstrate that the tidal dynamics of deposition into and resuspension of particles from temporally and spatially limited material sources at the bottom is the dominant process in the turbidity maximum while the nontidal gravitational circulation acts as a long-term source and sink. There is a remarkable repeatability of concentration patterns during similar discharge conditions. the tidal excursion can cause tidal fluctuations of about 10%o 14,373 14,374 GRABEMANN AND KRAUSE' TIME SERIES OF SUSPENDED MATTER ß ••i• OFE Bremerhaven NORDENHAM ,"

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A method to measure suspended load transports in estuaries

Cited by 18 publications

References 6 publications

Suspended Matter, Chl-a, CDOM, Grain Sizes, and Optical Properties in the Arctic Fjord-Type Estuary, Kangerlussuaq, West Greenland During Summer

Suspended Matter, Chl-a, CDOM, Grain Sizes, and Optical Properties in the Arctic Fjord-Type Estuary, Kangerlussuaq, West Greenland During Summer

Potential of turbidity monitoring for measuring the transport of suspended solids in streams

Transport processes of suspended matter derived from time series in a tidal estuary

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