As a part of the MAST2 GS-M Coastal Morphodynamics project, the predictions of four sediment transport models have been compared with detailed laboratory data sets obtained in the bottom boundary layer beneath regular waves, asymmetrical waves, and regular waves superimposed co-linearly on a current. Each data set was obtained in plane bed, sheet flow, conditions and each of the four untuned nu...

Sediment-quality assessment often is hindered by the lack of agreement between chemical and biological lines of evidence. One limitation is that the bulk sediment toxicant concentration, the most widely used chemical parameter, does not always represent the bioavailable concentration, particularly for hydrophobic organic compounds (HOCs) in highly contaminated sediments. In the present study, w...

where Eq. A1.1a is for dissolved species, and Eq. A1.1b is for solid species. Here, t is time, and x is the depth coordinate below the sediment–water interface. U is the advection (burial) velocity. Rj values are the rates of chemical and biochemical reactions, and nij is the stoichiometric coefficient of species i in reaction j. Q is the sediment porosity. The factor j is equal to (1 2 Q)r, wh...

1. The purpose of this report is to determine the concentrations of tributyltin in sediments that would be protective against adverse effects on prey species of salmonids listed under the US Endangered Species Act. 2. Two approaches for determining adverse sediment concentrations due to tributyltin (TBT) contamination are presented here. The first is the equilibrium partitioning (EqP) approach,...

Accumulation of Ot alternative antifoulants in sediment is the focus of this research. Much research had been done on surface sediment, but in this report, the accumulation in the sediment core was studied. The Ot alternative antifoulants, Diuron, Sea-Nine211, and Irgarol 1051, and the latter's degradation product, M1, were investigated in five samples from the northern part of Hiroshima Bay. O...

The transport of sediment over an intertidal mudflat by a cross-shore tidal current is investigated analytically by formulating a mathematical model of the fluid and particulate motion. The model exploits the low gradient of the intertidal flats and is based upon a shallow-layer approximation. It is found that the sediment transport comprises advection with the mean flow, deposition and erosion...

The accumulative partitioning of Pb and Cu in the Rhizophora apiculata was studied randomly in the Setiu mangrove forest, Terengganu. Samples of leaves, barks and roots were collected randomly from the selected studied species. Sediments between the roots of the sampled mangrove plants were also collected. The results from analysis for Rhizophora apiculata shows that the concentration of Pb and...

to assess the environmental radioactivity levels and hence to determine the population exposure in kutubdia island, bangladesh the sediment samples were analyzed by using gamma ray spectrometry. in those sediment samples the average activity concentration of natural radionuclides 238u, 232th and 40k were found 15.39±1.67, 38.35±0.76 and 475.51±21.15 bq/kg respectively. the activity concentratio...

A database composed of 673 natural rainfall events with sediment concentration measurements at the field or plot scale was analysed. Measurements were conducted on similar soil type (loess soils prone to sealing phenomenon) to apprehend the variability and complexity involved in interrill erosion processes attributable to soil surface conditions. The effects of the dominant controlling factors ...

A light attenuation sensor system (LASS) for measurements in waters is described in this paper. The LASS records irradiance at multiple levels in the water column to provide a measure of the diffuse light attenuation coefficient which is strongly affected by suspended sediment. Dimensional analysis and geometric optical theory are used to relate the irradiance attenuation to sediment properties...