A mixing model derived from first principles describes the bulk density (BD) of intertidal wetland sediments as a function of loss on ignition (LOI). The model assumes that the bulk volume of sediment equates to the sum of self-packing volumes of organic and mineral components or BD = 1/[LOI/k1 + (1-LOI)/k2], where k1 and k2 are the self-packing densities of the pure organic and inorganic compo...

sedimentation is one of the most important problems in harbors that results in considerable economic costs. harbor planforms affects the flow pattern in the harbor basin and consequently, plays an important role in sediment transport and sedimentation. in the present study, a two dimensional depth-averaged hydrodynamic and sediment transport model has been developed to investigate the effect of...

nozzle and sediment determ ines the rate of scour . Under fully turbulent conditions, the re la~ive dimensions of the sccur hole d (:pend onl y upon the t ime pa rame ter and the ratio between the fictitious axial jer velocity a t the bed and the fa ll ve locity of the sediment particles. There exist two distinct values of this ratio, at which the eroding action of the jet becomes particularly ...

the intakes usually have been used in water distribution networks, irrigation channels, sewage networks, and the water/wastewater treatment facilities, etc. lack of sediment control entered to the intake channel is the main reason of entering sediments to the installation systems, which makes many problems for different parts. due to suspended particles in water, the facilities used such as pum...

the efficiency of a collar in reducing the scour depth around circular and rectangular piers is studied at different flow intensities (ratio of upstream shear stress to sediment critical shear stress). rectangular piers aligned with the flow as well as skewed at 5º, 10º, 20º were examined. previous studies had shown that with collar the equilibrium time of scouring increases considerably. to re...

Pectinaria (Lagis) koreni (Malmgren) is an abundant, deposit-feeding, infaunal inhabitant of shallow-water marine environments in northern Europe. Laboratory experiments were performed to quantify the polychaete's sediment processing in 2 distinct sediments, 1 fine-grained and high in combustibles, the other coarse-grained and low in combustibles. Gut passage time and time to pseudodefecation w...

The revised universal soil loss equation (RUSLE), the sediment delivery distributed (SEDD) model, and ArcView GIS were used to estimate the impacts of no-till practice on soil erosion and sediment yield in Pataha Creek Watershed, a typical dryland agricultural watershed in southeastern Washington. The results showed that the average cell soil loss decreased from 11.09 to 3.10 t/ha yr for the wh...

Data from the Catsop catchment in South Limburg, Netherlands was simulated with the model KINEROS2. The results of calibration and validation on a split set of runoff and sediment data are reported and the variations in apparent parameters are analyzed. Calibration was performed with regard to the temporal distribution of runoff and sediment rather than single values such as total or peak rates...

Bioturbation activity of sediment-dwelling organisms promotes the release of contaminants across the benthic-pelagic ecosystem boundary, thereby affecting the exposure to and uptake of sediment associated contaminants at the sediment-water interface by themselves and the entire community around them. This way, bioturbation activity may contribute to species specific sensitivities to sediment as...