intro story Coast / Estuary

Coast / Estuary

Coastal systems are among the most dynamic physical systems on earth and are subject to a large variety of forces. The morphodynamic changes occurring to coastlines worldwide are of great interest and importance. These changes occur as a result of the erosion of sediments, its subsequent transport as bed load or suspended load, and eventual deposition. 
 
Estuaries are partly enclosed water bodies that have an open connection to the coast. Estuaries generally have one or more branching channels, intertidal mudflats and/or salt marshes. Intertidal areas are of high ecological importance and trap sediments (sands, silts, clays and organic matter).
Within the Delft3D modelling package a large variation of coastal and estuarine physical and chemical processes can be simulated. These include waves, tidal propagation, wind- or wave-induced water level setup, flow induced by salinity or temperature gradients, sand and mud transport, water quality and changing bathymetry (morphology). Delft3D can also be used operationally e.g. storm, surge and algal bloom forecasting. 
 
On this discussion page you can post questions, research discussions or just share your experience about modelling coastal and/or estuarine systems with Delft3D FM. 
 

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Sub groups
D-Flow Flexible Mesh
DELWAQ
Cohesive sediments & muddy systems

 

 

Message Boards

Model setup - wave-driven longshore currents

JG
João Gil, modified 7 Years ago.

Model setup - wave-driven longshore currents

Padawan Posts: 29 Join Date: 10/24/12 Recent Posts
Dear all,

I'm trying to set up a model which intends to simulate wave-driven longshore currents in a coastal area of, aproximately, 800m (longshore) x 650m (cross-shore). The forcing is a constant wave condition (wave height, period and direction) at the offshore boundary of the wave grid.

The model is composed of two rectangular grids (hydrodynamic and wave grid). In comparison with FLOW grid, WAVE grid is extended up- and down-drift in order to take into account the absence of lateral boundaries. The adopted hydrodynamic boundaries were Neumann, for lateral boundaries, and a constant water level for the offshore boundary.

As a result, I'd expect obtaining stationary variables (e.g. water level, Hm0 and longshore currents). However, I wasn't able to obtain stationary currents, in contrast with Hm0 and water level, which remain stationary after 20 min of simulation. What am I missing? Isn't my bathymetry (which you might find attached) uniform enough?

Any sugestion are welcome.
João Gil
MV
Maarten van Ormondt, modified 7 Years ago.

RE: Model setup - wave-driven longshore currents

Padawan Posts: 45 Join Date: 3/11/11 Recent Posts
Hi Joao,

It sounds like you're doing the right thing. This issue seems to keep popping up recently. I'm trying to come up with a solution. Could you send me all of your input in a zip file, so I can have a look at it?

Maarten van Ormondt

Maarten.vanOrmondt@deltares.nl
JG
João Gil, modified 7 Years ago.

RE: Model setup - wave-driven longshore currents

Padawan Posts: 29 Join Date: 10/24/12 Recent Posts
Maarten van Ormondt:
Hi Joao,

It sounds like you're doing the right thing. This issue seems to keep popping up recently. I'm trying to come up with a solution. Could you send me all of your input in a zip file, so I can have a look at it?

Maarten van Ormondt

Maarten.vanOrmondt@deltares.nl


I sent you an email.
Thanks in advance,

João Gil