In situ flume measurements of resuspension in the North Sea

Thompson, Charlie; Couceiro, Fay; Fones, Gary R.; Helsby, R.; Amos, Carl L.; Black, K. S.; Parker, E. R.; Greenwood, Naomi; Statham, Peter J.; Kelly-Gerreyn, B.A.

doi:10.1016/j.ecss.2011.05.026

Cited by 51 publications

(30 citation statements)

References 61 publications

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“…Because of a relatively small water depth and a large water surface area, shallow lakes are particularly susceptible to eutrophication-induced algal bloom and water quality degradation [8][9][10]. For a shallow lake, the wind-induced shear stress on the lake surface can be efficiently transferred downward through the shallow water column to the lakebed, resuspending bed sediments from which nutrients can be released into the ambient water [11][12][13][14][15][16]. The threshold shear stress, beyond which the resuspension of bed sediments will incept, depends on the physiochemical characteristics (e.g., texture, age and compaction) of the sediments [17,18].…”

Section: Introductionmentioning

confidence: 99%

Spatiotemporal Distribution of Eutrophication in Lake Tai as Affected by Wind

Zhang

Wang

et al. 2017

Water

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Abstract:One common hypothesis is that wind can affect concentrations of nutrients (i.e., nitrogen and phosphorus) and chlorophyll-a (Chl-a) in shallow lakes. However, the tests of this hypothesis have yet to be conclusive in existing literature. The objective of this study was to use long-term data to examine how wind direction and wind speed affect the spatiotemporal variations of total nitrogen (TN), total phosphorus (TP) and Chl-a in Lake Tai, a typical shallow lake located in east China. The results indicated that the concentrations of nutrients and Chl-a tended to decrease from the northwest to the southeast of Lake Tai, with the highest concentrations in the two leeward bays (namely Meiliang Bay and Zhushan Bay) in the northwestern part of the lake. In addition to possible artificial reasons (e.g., wastewater discharge), the prevalent southeastward winds in warm seasons (i.e., spring and summer) and northwestward winds in cool seasons (i.e., fall and winter) might be the major natural factor for such a northwest-southeast decreasing spatial pattern. For the lake as a whole, the concentrations of TN, TP and Chl-a were highest for a wind speed between 2.1 and 3.2 m·s −1 , which can be attributed to the idea that the wind-induced drifting and mixing effects might be dominant in the bays while the wind-induced drifting and resuspension effects could be more important in the other parts of the lake. Given that the water depth of the bays was relatively larger than that of the other parts, the drifting and mixing effects were likely dominant in the bays, as indicated by the negative relationships between the ratios of wind speed to lake depth, which can be a surrogate for the vertical distribution of wind-induced shear stress and the TN, TP and Chl-a concentration. Moreover, the decreasing temporal trend of wind speed in combination with the ongoing anthropogenic activities will likely increase the challenge for dealing with the eutrophication problem of Lake Tai.

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Section: Introductionmentioning

confidence: 99%

Spatiotemporal Distribution of Eutrophication in Lake Tai as Affected by Wind

Zhang

Wang

et al. 2017

Water

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“…45 In situ measurements have shown that SPM can vary by a factor of 2 or more during the day due to horizontal advection and/or vertical resuspension forced by tides or wind events. 46,47 Temporal frequency afforded by GOCI for the first time allows us to study these high temporal frequency variations in the water surface.…”

Section: Physical and Bio-optical Conditions During Geostationary Ocementioning

confidence: 99%

Hourly turbidity monitoring using Geostationary Ocean Color Imager fluorescence bands

Amin¹,

Shulman

2015

J. Appl. Remote Sens

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Abstract. The Geostationary Ocean Color imager (GOCI) is the first geostationary ocean color satellite sensor that collects hourly images eight times per day during daylight. This high frequency image acquisition makes it possible to study more detailed dynamics of red tide blooms, sediment plumes, and colored dissolved organic matter plumes, and can aid in the prediction of biophysical phenomena. We apply the red band difference and the fluorescence line height algorithms to GOCI imagery to separate waters with high algal and nonalgal particles and validate the results with the MODIS imagery. We also track optical features using hourly GOCI imagery and assess their movement through comparisons with predicted ocean currents derived from the navy coastal ocean model and tidal data.

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“…Tolhurst et al, 2006;Lundkvist et al, 2007b). While coarse non-cohesive sediments show predictable relationships between grain size and erosion threshold (Dyer, 1986;Thompson et al, 2011), the erosion dynamics of cohesive sediments is more complex and difficult to predict alone from physical properties, such as particle size, water content, bulk density, organic content, depositional history and air exposure. The erosion threshold of cohesive coastal sediments is instead under control of biological factors including microphytobenthos activity, macrophyte growth as well as meio-and macrofauna activity Paterson et al, 2000;De Brouwer et al, 2005).…”

Section: Introductionmentioning

confidence: 99%

Influence of benthic macroinvertebrates on the erodability of estuarine cohesive sediments: Density- and biomass-specific responses

Kristensen

Neto

Lundkvist

et al. 2013

Estuarine, Coastal and Shelf Science

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Regional index term: Portugal Mondego EstuaryKeywords: erosion threshold erosion rate behaviour macrofauna feeding microphytobenthos biostabilization a b s t r a c tThe impact of three dominating benthic invertebrates on sediment stability and erosion conditions of cohesive sediments in the Mondego Estuary, Portugal, was examined in laboratory annular flume experiments. The purpose was to test how the life habits and body size of the three involved species (Hydrobia ulvae, Nereis diversicolor and Scrobicularia plana) in terms of density or biomass influence sediment erosion. All three species decreased the free-stream erosion threshold (u c ) and increased erosion rate (E), since their feeding activities diminished the surface stabilizing effect of extracellular polymeric substances (EPS) produced by microphytobenthos. S. plana had the highest and H. ulvae the lowest impact when related to density (factor of 29 for u c and factor of 19 for E), while H. ulvae was more important than S. plana when related to biomass (factor of 4 for u c and factor of 6 for E). N. diversicolor had intermediate density-specific (4e6 times higher than H. ulvae) and lowest biomass-specific (2e3 times lower than S. plana) effects on erosion. It appears that faunal erosion impacts preferably should be reported in biomass units for comparative purposes because individual behavioural effects of a smallbodied species like H. ulvae functionally can be relatively more important than those of a 100 times heavier S. plana individual. This is clearly evidenced from the strongly diminished response in suspended Chlorophyll-a content in the presence of the former than the latter species, which is caused by an efficient microphytobenthos grazing by H. ulvae. It is also important to emphasize that the total faunal impact on erosion threshold in a certain area is dictated by combination of contributions from individual species. The total outcome is unpredictable and controlled by synergistic and antagonistic speciesspecific effects, species interactions as well as environmental and sediment conditions.

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In situ flume measurements of resuspension in the North Sea

Cited by 51 publications

References 61 publications

Spatiotemporal Distribution of Eutrophication in Lake Tai as Affected by Wind

Spatiotemporal Distribution of Eutrophication in Lake Tai as Affected by Wind

Hourly turbidity monitoring using Geostationary Ocean Color Imager fluorescence bands

Influence of benthic macroinvertebrates on the erodability of estuarine cohesive sediments: Density- and biomass-specific responses

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