Studies of carbon fluxes in marine ecosystems are often done by using box model approaches with basin size boxes, or highly resolved 3D models, and an emphasis on the pelagic component of the ecosystem. Those approaches work well in the ocean proper, but can give rise to considerable problems when applied to coastal systems, because of the scale of certain ecological niches and the fact that benthic organisms are the dominant functional group of the ecosystem. In addition, 3D models require an extensive modeling effort. In this project, an intermediate approach based on a high resolution (20×20 m) GIS data-grid has been developed for the coastal ecosystem in the Laxemar area (Baltic Sea, Sweden) based on a number of different site investigations. The model has been developed in the context of a safety assessment project for a proposed nuclear waste repository, in which the fate of hypothetically released radionuclides from the planned repository is estimated. The assessment project requires not o...

https://bioone.org/journals/AMBIO-A-Journal-of-the-Human-Environment/volume-35/issue-8/0044-7447(2006)35[486:MEMBTB]2.0.CO;2/Marine-Ecosystem-Modeling-Beyond-the-Box--Using-GIS-to/10.1579/0044-7447(2006)35[486:MEMBTB]2.0.CO;2.pdf

Marine ecosystem modeling beyond the box: using GIS to study carbon fluxes in a coastal ecosystem.

In this work a fast computational particles tracer model is developed based on Particle-In-Cell method to estimate the sediment transport in the access zone of a river port area. To apply the particles tracer method, first it is necessary to calculate the hydrodynamic fields of the study zone to determine the velocity fields in the three directions. The particle transport is governed mainly by the velocity fields and the turbulent dispersion. The mechanisms of dispersion and resuspension of particles are based in stochastic models, which describes the movement through a probability function. The developed code was validated using two well known cases with a discrete transformation obtaining a max relative error around 4.8% in both cases. The simulations were carried out with 350,000 particles allowing us to determine under certain circumstances different hydrodynamic scenarios where the zones are susceptible to present erosion and siltation at the entrance of the port.

Light Particle Tracking Model for Simulating Bed Sediment Transport Load in River Areas

Two-dimensional numerical models have been extensively used in the far field to solve hydrodynamics and the associated pollutant transport. However the results obtained from these models may not be suitable when used in the near field or in areas where the hydrodynamics has three-dimensional features, sucl as wind-induced currents in the nearshore region or wave-induced currents in the surf zone. A 3D Lagrangian numerical model has been developed to solve the three-dimensional convection-diffusion equation in order to simulate pollutant transport in non-uniform and stratified hydrodynamic flows. In this paper the model characteristics and its calibration process are described and posteriorly it is applied to the case of the Besos marine outfall, near Barcelona (Spanish Mediterranean coast) and to simulate tracer clouds dispersion in the surf-zone.

A Lagrangian 3D numerical model of pollutant dispersion in coastal waters

Two-dimensional numerical models have been extensively used in the far field to solve hydrodynamics and the associated pollutant transport. However the results obtained from these models may not be suitable when used in the near field or in areas where the hydrodynamics has threedimensional features, such as wind-induced currents in the nearshore region or wave-induced currents in the surf zone. A 3D Lagrangian numerical model has been developed to solve the three-dimensional convectiondiffusion equation in order to simulate pollutant transport in non-uniform and stratified hydrodynamic flows. In this paper the model characteristics and its calibration process are described and posteriorly it is applied to the case of the Besos marine outfall, near Barcelona (Spanish Mediterranean coast) and to simulate tracer clouds dispersion in the surf-zone.

/pdf/a-lagrangian-3d-numerical-model-ofpollutant-dispersion-in-4yrq6xxhd1.pdf

M. Mestres

Papers

A Lagrangian 3D numerical model of pollutant dispersion in coastal waters

A Lagrangian 3D Numerical Model OfPollutant Dispersion In Coastal Waters