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Focuses on the nonlinear unified equations for water waves propagating or uneven bottoms in the nearshore region in China. Use of Hamiltonian variational principle for water waves; Extension of Airy's nonlinear shallow-water equations; Dispersion relation for second-order Stokes wave and high order Boussinesq-type equations.

Examines a three-dimensional transport model for suspended sediment by waves and current. Variation of the averaged wave and turbulence situation; Equation of suspended sediment by waves and currents; Influence of waves on current field.

Abstract: This study investigated the effects of sediment dewatering on the phosphorus transformations concerning about the production and emission of phosphine in the intertidal marsh of the Yangtze Estuary. The concentrations of matrix-bound phosphine ranged from 18.62–72.53ngkg−1 and 31.14–61.22ngkg−1 within the August and January exposure incubations, respectively. The responses of matrix-bound phosphine concentrations to sediment dessication demonstrate that the production (or accumulation) of matrix-bound phosphine significantly increased with water loss at the start of the emersion incubations. However, further dehydration inhibited the formation of matrix-bound phosphine in sediments. The significant correlations of matrix-bound phosphine with the organic-P bacteria abundance and alkaline phosphatase activities implicate that the production of matrix-bound phosphine within the dessication incubations was linked closely to the microbial decomposition of organic P. The emissions of phosphine generally decreased with sediment dewatering, with the fluxes of 7.51–96.73ngm−2 h−1 and 5.34–77.74ngm−2 h−1 over the exposure incubations of both August and January, respectively. Also, it is observed that the releases of phosphine during the entire exposure periods were affected not only by its production but also by sediment water and redox conditions. [Copyright &y& Elsevier]

Abstract: A dike–groyne module is developed and implemented into the unstructured-grid, three-dimensional primitive equation finite-volume coastal ocean model (FVCOM) for the study of the hydrodynamics around human-made construction in the coastal area. The unstructured-grid finite-volume flux discrete algorithm makes this module capable of realistically including narrow-width dikes and groynes with free exchange in the upper column and solid blocking in the lower column in a terrain-following coordinate system. This algorithm used in the module is validated for idealized cases with emerged and/or submerged dikes and a coastal seawall where either analytical solutions or laboratory experiments are available for comparison. As an example, this module is applied to the Changjiang Estuary where a dike–groyne structure was constructed in the Deep Waterway channel in the inner shelf of the East China Sea (ECS). Driven by the same forcing under given initial and boundary conditions, a comparison was made for model-predicted flow and salinity via observations between dike–groyne and bed-conforming slope algorithms. The results show that with realistic resolution of water transport above and below the dike–groyne structures, the new method provides more accurate results. FVCOM with this MPI-architecture parallelized dike–groyne module provides a new tool for ocean engineering and inundation applications in coastal regions with dike, seawall and/or dam structures. [Copyright &y& Elsevier]

High-turbidity water is a common feature in the estuary and inner shelf. Sediment suspension functions as a modulator that directly influences the interactions among nutrients, phytoplankton and other related ecosystem variables. A physical-biological coupling model system was applied to examine the impact of sediment front on interactions among on suspended sediment, vertical mixing, nutrients and phytoplankton over the inner shelf off the high-turbidity, phosphate-limited Changjiang Estuary. The physical model was the Finite-Volume Community Ocean Model (FVCOM) and the biological model was the European Regional Seas Ecosystem Model (ERSEM). Results revealed that in the nearshore region the growth of phytoplankton over the spring-summer seasons was limited by suspended sediments and intensified vertical mixing during the autumn-winter seasons extended the sediment-induced suppression extended offshore to restrict the phytoplankton growth over the shelf. Nutrients were diluted by spreading of freshwater discharge and significantly decreased off the suspended sediment front due to the depletion by the offshore phytoplankton growth. The simulation results showed that although the diatom phytoplankton dominated the Chlorophyll a (Chl- a) concentration, the non-diatom group had a more contribution to the biomass. The relatively high phytoplankton biomass was found over the offshore deep underwater valley area as results of remote advection by the Taiwan Warm Current and weak turbulent mixing. • Physical-biogeochemical model was developed to study sediment-ecosystem interaction. • Model revealed high nutrients within the front and dense Chl a out of the front. • Chl a was mainly from diatom, however non-diatom group contributed more on biomass. [ABSTRACT FROM AUTHOR]